Curable silicone composition, cured product thereof, and method for producing same

文档序号：231438 发布日期：2021-11-09 浏览：6次中文

阅读说明：本技术 固化性有机硅组合物、其固化物及其制造方法 (Curable silicone composition, cured product thereof, and method for producing same ) 是由山崎亮介尾崎弘一今泉彻于 2020-03-18 设计创作，主要内容包括：本发明提供一种热熔性和成型性优异,并且即使大量配合功能性无机填料,也不损害所得到的固化物的柔软性、强韧性以及应力缓和特性的固化性有机硅组合物等。一种固化性有机硅组合物及其用途,该固化性有机硅组合物含有：重均分子量在2000～15000的范围内,含有所有硅氧烷单元的至少20摩尔％以上的SiO-(4/2)所示的硅氧烷单元的聚有机硅氧烷树脂；以及一种以上功能性填料,组合物中的有机硅成分每100g的包含碳-碳双键的固化反应性官能团中的乙烯基(CH2＝CH-)部分的含量为0.05～1.50摩尔％,该固化性有机硅组合物作为组合物整体具有热熔性。(The invention provides a curable silicone composition and the like which have excellent hot-melt properties and moldability and do not impair flexibility, toughness and stress relaxation properties of the resulting cured product even when a large amount of a functional inorganic filler is blended. A curable silicone composition and use thereof, the curable silicone composition comprising: SiO having a weight average molecular weight of 2000 to 15000 and containing at least 20 mol% or more of all siloxane units 4/2 A polyorganosiloxane resin of the siloxane unit shown; and one or more functional fillers, wherein the content of vinyl (CH2 ═ CH-) moieties in the silicone component in the composition is 0.05 to 1.50 mol% per 100g of the curing reactive functional groups containing carbon-carbon double bonds, and the curable silicone composition has a hot-melt property as the whole composition.)

1. A curable silicone composition, comprising:

has a weight-average molecular weight Mw in the range of 2000-15000 measured by GPC as gel permeation chromatography using toluene as a solvent, and contains SiO in an amount of at least 20 mol% of all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown; and

more than one kind of functional filler is added,

the curable silicone composition has a content of a vinyl group CH2 ═ CH-moiety in the curable functional group containing a carbon-carbon double bond per 100g of the silicone component in the composition, which is 0.05 to 1.50 mol%, and the curable silicone composition as a whole has a hot-melt property.

2. The curable silicone composition according to claim 1, wherein the curable silicone composition comprises:

100 parts by mass of (A) in a ratio of 0: 100-75: 25 in a mass ratio of (a1) to (a2) below, and a polyorganosiloxane resin having a weight average molecular weight Mw of 2000 to 15000 as measured by GPC which is gel permeation chromatography using toluene as a solvent for the (a1) component and the (a2) component:

(A1) makingHas a curing reactive functional group containing a carbon-carbon double bond in the molecule, and contains at least 20 mol% or more of SiO based on the total siloxane units_4/2A polyorganosiloxane resin having a siloxane unit represented by,

(A2) Has no hot-melt property as a whole molecule, has no curing reactive functional group containing a carbon-carbon double bond in the molecule, and contains at least 20 mol% or more of SiO of all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown;

10 to 100 parts by mass of (B) a linear or branched polyorganosiloxane which is liquid at 25 ℃ and has at least two curing reactive functional groups containing a carbon-carbon double bond in the molecule;

the amount of (C) the curing agent required for curing of the present composition is one or more selected from the following (C1) or (C2):

(c1) organic peroxide,

(c2) An organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in the molecule and a hydrosilylation reaction catalyst; and

(D) a functional filler, wherein the functional filler is a functional filler,

(D) the amount of the component (A) is 10 to 2000 parts by mass based on 100 parts by mass of the sum of the components (A) and (B).

3. The curable silicone composition according to claim 2,

(A1) a non-hot-melt polyorganosiloxane resin represented by the following average unit formula (A1-1):

(R¹ ₃SiO_1/2)_a(R¹ ₂SiO_2/2)_b(R¹SiO_3/2)_c(SiO_4/2)_d(R²O_1/2)_e

in the formula, each R¹Independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, wherein all R in one molecule¹1 to 12 mol% of (a) is an alkenyl group; each R²Is a hydrogen atom or has 1 toAn alkyl group of 10 carbon atoms; a. b, c, d and e are numbers satisfying the following: a is more than or equal to 0.10 and less than or equal to 0.60, b is more than or equal to 0 and less than or equal to 0.70, c is more than or equal to 0 and less than or equal to 0.80, d is more than or equal to 0 and less than or equal to 0.65, e is more than or equal to 0 and less than or equal to 0.05, wherein c + d>0.20, and a + b + c + d is 1,

(A2) a non-hot-melt polyorganosiloxane resin represented by the following average unit formula (A2-1):

(R³ ₃SiO_1/2)_f(R³ ₂SiO_2/2)_g(R³SiO_3/2)_h(SiO_4/2)_i(R²O_1/2)_j

in the formula, each R³Independently a monovalent hydrocarbon group having 1 to 10 carbon atoms and containing no carbon-carbon double bond; r²An alkyl group having a hydrogen atom or 1 to 10 carbon atoms; f. g, h, i and j are numbers satisfying the following: f is more than or equal to 0.35 and less than or equal to 0.55, g is more than or equal to 0 and less than or equal to 0.20, h is more than or equal to 0.45 and less than or equal to 0.65, j is more than or equal to 0 and less than or equal to 0.05, and f + g + h + i is 1,

(B) component (B1) is a linear polydiorganosiloxane represented by the following structural formula:

R⁴ ₃SiO(SiR⁴ ₂O)_kSiR⁴ ₃

in the formula, each R⁴Independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, wherein R in one molecule⁴At least two of (a) are alkenyl groups, and k is a number of 20 to 5000.

4. The curable silicone composition according to claim 2 or 3,

(A1) the component (A2) and the component (B) are spherical polyorganosiloxane resin particles having an average primary particle diameter of 1 to 20 μm.

5. The curable silicone composition according to any one of claims 2 to 4, wherein component (C) comprises at least (C2-1) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in the molecule and (C2-2) a hydrosilylation reaction catalyst,

the content of the organohydrogenpolysiloxane (c2-1) is such that the molar ratio of silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane resin is in the range of 0.5 to 20 relative to the curing reactive functional groups containing carbon-carbon double bonds in the component (A) and the component (B).

6. The curable silicone composition according to any one of claims 2 to 5, wherein component (D) is a functional filler containing one or more selected from a reinforcing filler, a white pigment, a thermally conductive filler, an electrically conductive filler, and an organic filler.

7. The curable silicone composition according to any one of claims 1 to 6, wherein,

the curable silicone composition is in the form of granules, or sheets.

8. A curable silicone composition sheet comprising the curable silicone composition according to any one of claims 1 to 6, wherein the curable silicone composition sheet is substantially flat and has a thickness of 10 to 1000 μm.

9. A film-like adhesive which is the curable silicone composition sheet according to claim 8.

10. A peelable laminate, comprising:

the curable silicone composition sheet of claim 8; and

and a sheet-like substrate having a release surface on one surface or both surfaces of the curable silicone composition sheet, the release surface facing the curable silicone composition sheet.

11. A cured product obtained by curing the curable silicone composition according to any one of claims 1 to 6.

12. A cured product according to claim 11, which is used as a member for a semiconductor device.

13. A semiconductor device comprising the cured product according to claim 11.

14. A method for producing the curable silicone composition according to any one of claims 1 to 6, characterized in that,

the granulation is performed by mixing only the components constituting the curable silicone composition under a temperature condition of not more than 50 ℃.

15. A method for molding a cured product, comprising at least the following steps (I) to (III):

a step (I) of heating the curable silicone composition according to any one of claims 1 to 6 to 100 ℃ or higher to melt the composition;

a step (II) of injecting the liquid curable silicone composition obtained in the step (I) into a mold or distributing the curable silicone composition obtained in the step (I) over the mold by closing the mold; and

and (III) curing the curable silicone composition injected in the step (II).

16. A method for producing a curable silicone composition sheet according to claim 8, comprising:

step 1: a step of mixing the raw material components of the curable silicone composition according to any one of claims 1 to 6 at a temperature of 50 ℃ or higher;

and a step 2: a step of kneading the mixture obtained in step 1 while heating and melting the mixture;

step 3: laminating the mixture obtained in step 2 after the heating and melting between films having at least one release surface;

and step 4: and a step of stretching the laminate obtained in step 3 between rolls to form a curable silicone sheet having a predetermined film thickness.

Technical Field

The present invention relates to a curable silicone composition which can be obtained by a simple production method, has excellent hot-melt properties and moldability, and does not impair flexibility, toughness, and stress relaxation properties of the obtained cured product even when a large amount of a functional inorganic filler is blended, a molded product (such as pellets and sheets) thereof, and a cured product thereof. The present invention also relates to a cured product of the composition, use thereof (particularly, a member for a semiconductor, a semiconductor having the cured product, and the like), a method for producing the composition, a method for molding a cured product, and the like.

Background

Curable silicone compositions are used in a wide variety of industrial fields because they cure to form cured products having excellent heat resistance, cold resistance, electrical insulation, weather resistance, water resistance, and transparency. A cured product of such a curable silicone composition is generally less likely to be discolored than other organic materials, and is also suitable as an optical material and a sealing agent for a semiconductor device because of a small decrease in physical properties.

The present applicant has proposed a hot-melt curable particulate silicone composition and a reactive silicone composition for molding in patent documents 1 and 2. Further, the present applicant disclosed in patent document 3a transparent hot-melt curable silicone composition using a methyl silicone resin.

On the other hand, in recent years, the reduction in size and the increase in output of optical semiconductor devices and the like have been advanced, and there has been a strong demand for a silicone composition which can satisfy the requirements such as the improvement of thermal conductivity and the improvement of heat dissipation characteristics by adding a functional filler represented by a heat dissipation filler such as alumina to the composition in addition to the improvement of physical characteristics such as the linear expansion coefficient of a cured product. For example, patent document 4 proposes a hot-melt curable silicone composition in which a functional filler is highly filled in the composition.

However, when a large amount of a functional inorganic filler is blended in these compositions, there is a problem that the melt characteristics (hot melt property) of the compositions, and the toughness and flexibility of the cured products are significantly impaired. Therefore, for example, it is difficult to achieve high thermal conductivity by adding a large amount of a thermally conductive inorganic filler such as alumina, or to significantly reduce the linear expansion coefficient by adding a large amount of a dimensionally stable inorganic filler such as silica. Therefore, there is a strong demand for a curable silicone composition that does not impair flexibility, toughness, and stress relaxation properties of the resulting cured product, and that has excellent hot-melt properties and moldability, even when a large amount of a functional inorganic filler is added.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2016/136243 pamphlet

Patent document 2: japanese patent laid-open No. 2014-009322

Patent document 3: japanese Kohyo publication No. 2017-512224

Patent document 4: japanese laid-open patent publication No. 2013-221082

Disclosure of Invention

Problems to be solved by the invention

The present invention aims to provide a curable silicone composition which is hot-melt, has excellent workability such as secondary molding and curing properties, and provides a cured product which does not impair flexibility, toughness and stress relaxation properties even when a large amount of a functional inorganic filler is added. The curable silicone composition is provided in the form of granules, sheets, and the like, and in the form of a releasable laminate comprising a sheet of the curable silicone composition. Further, an object of the present invention is to provide a member for a semiconductor device comprising a cured product of the curable silicone composition, a semiconductor device having the cured product, and a method for molding a cured product.

Means for solving the problems

The present inventors have conducted intensive studies and as a result, found that the above-mentioned technical problems can be solved by a curable silicone composition containing: has a weight average molecular weight (Mw) of 2000-15000 determined by Gel Permeation Chromatography (GPC) using toluene as a solvent, and contains SiO in an amount of at least 20 mol% of all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown; and one or more functional fillers, wherein the content of vinyl (CH2 ═ CH-) moieties in the curing reactive functional groups containing carbon-carbon double bonds in the composition is 0.05 to 1.50 mol% per 100g of the silicone component, and the curable silicone composition has hot-melt properties as a whole.

More specifically, the present invention relates to a curable silicone composition containing: has a weight average molecular weight (Mw) of 2000-15000 determined by Gel Permeation Chromatography (GPC) using toluene as a solvent, and contains SiO in an amount of at least 20 mol% of all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown; and one or more functional fillers, wherein the content of vinyl (CH2 ═ CH-) moieties in the curing reactive functional groups containing carbon-carbon double bonds in the composition is 0.05 to 1.50 mol% per 100g of the silicone component, and the curable silicone composition has hot-melt properties as a whole.

The curable silicone composition of the present invention is characterized by containing: 100 parts by mass of (A) in a ratio of 0: 100-75: 25 in a mass ratio of (a1) to (a2) below, and a polyorganosiloxane resin having a weight average molecular weight (Mw) of (a1) to (a2) in the range of 2000 to 15000 as measured by Gel Permeation Chromatography (GPC) using toluene as a solvent:

(A1) has no hot-melt property as a whole molecule, has a curing reactive functional group containing a carbon-carbon double bond in the molecule, and contains at least 20 mol% or more of SiO of all siloxane units_4/2A polyorganosiloxane resin having a siloxane unit represented by,

the amount of (C) the curing agent required for curing of the present composition is one or more selected from the following (C1) or (C2):

(c1) organic peroxide,

(c2) An organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in the molecule and a hydrosilylation reaction catalyst; and

(D) a functional filler, wherein the functional filler is a functional filler,

(D) the amount of the component (A) is 10 to 2000 parts by mass based on 100 parts by mass of the sum of the components (A) and (B), and the curable silicone composition of the present invention contains: has a weight average molecular weight (Mw) of 2000-15000 determined by Gel Permeation Chromatography (GPC) using toluene as a solvent, and contains SiO in an amount of at least 20 mol% of all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown; and one or more functional fillers, the content of vinyl (CH2 ═ CH-) moieties in the curing reactive functional groups containing carbon-carbon double bonds in the composition corresponding to 100g of silicone ingredient is 0.05 ℃ -1.50 mol%.

The present invention has been achieved by finding that the above-mentioned technical problems can be solved by a curable silicone composition characterized by containing: 100 parts by mass of (A) in a ratio of 0: 100-75: 25 in a mass ratio of (a1) to (a2) below, and a polyorganosiloxane resin having a weight average molecular weight (Mw) of (a1) to (a2) in the range of 2000 to 15000 as measured by Gel Permeation Chromatography (GPC) using toluene as a solvent:

the amount of (C) the curing agent required for curing of the present composition is one or more selected from the following (C1) or (C2):

(c1) organic peroxide,

(c2) An organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in the molecule and a hydrosilylation reaction catalyst; and

(D) a functional filler, wherein the functional filler is a functional filler,

(D) the amount of the component (A) is 10 to 2000 parts by mass based on 100 parts by mass of the sum of the components (A) and (B). The curable silicone composition may be in the form of granules, or sheets.

The curable silicone composition can be in the form of a substantially flat sheet of curable silicone composition having a thickness of 10 to 1000 μm.

The curable silicone composition described above can be used for a releasable laminate having the following configuration. That is, the following peelable laminate may be used: comprising: the curable silicone composition sheet described above, and a sheet-like substrate provided with a release surface on one surface or both surfaces of the curable silicone composition sheet, the release surface facing the curable silicone composition sheet. Such a curable silicone composition sheet can be used as a film-like or sheet-like silicone adhesive.

The present inventors have also found that the above problems can be solved by a cured product of the curable silicone composition, particularly the use of the cured product as a member for a semiconductor device, and a semiconductor device (including at least one selected from a power semiconductor device, an optical semiconductor device, and a semiconductor device mounted on a flexible circuit board) having the cured product.

The present inventors have also found that the above problems can be solved by a production method and a method for molding a cured product, and the present invention has been achieved, namely, a production method characterized by granulating only the components constituting the above curable silicone composition by mixing them at a temperature of not more than 50 ℃; a molding method using the curable particulate silicone composition.

The above-mentioned molding method includes transfer molding, extrusion molding or injection molding, and the curable silicone composition of the present invention is preferably used as a molding material for these. The curable silicone composition of the present invention can be preferably used as a molding material for a so-called two-shot molding method in which a semiconductor element or a semiconductor circuit board is coated with a cured product by two-shot molding.

Similarly, the present inventors provide a method for producing a curable silicone composition sheet, which is characterized by comprising the following steps.

Step 1: mixing the raw material components of the curable silicone composition at a temperature of 50 ℃ or higher;

and a step 2: a step of kneading the mixture obtained in step 1 while heating and melting the mixture;

step 3: laminating the mixture obtained in step 2 after the heating and melting between films having at least one release surface;

and step 4: and a step of stretching the laminate obtained in step 3 between rolls to form a curable silicone sheet having a predetermined film thickness.

Advantageous effects

The curable silicone composition of the present invention is hot-melt, has excellent workability such as secondary molding and curing properties, and provides a cured product that does not impair flexibility and stress relaxation properties even when a large amount of filler is blended. Further, such a curable silicone composition can be produced only by a simple mixing step, and can be efficiently produced. Further, according to the present invention, such a curable silicone composition can be provided in the form of granules, sheets, and the like, and in the form of a releasable laminate comprising the curable silicone composition sheet. Further, a member for a semiconductor device formed of a cured product of the curable silicone composition, a semiconductor device having the cured product, and a method for molding the cured product can be provided.

Detailed Description

[ curable Silicone composition ]

The curable silicone composition of the present invention is characterized by containing: has a weight average molecular weight (Mw) of 2000-15000 determined by Gel Permeation Chromatography (GPC) using toluene as a solvent, and contains SiO in an amount of at least 20 mol% of all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown; and one or more functional fillers, wherein the content of vinyl (CH2 ═ CH-) moieties in the curing reactive functional groups containing carbon-carbon double bonds in the composition is 0.05 to 1.50 mol% per 100g of the silicone component, and the curable silicone composition has hot-melt properties as a whole. Need toIn the present invention, unless otherwise specified, "hot-melt" means that the resin composition has a softening point of 50 to 200 ℃, a melt viscosity (preferably a melt viscosity of less than 1000Pa · s) at 150 ℃, and a fluidity.

That is, the curable silicone composition of the present invention is characterized by containing a functional filler such as a reinforcing filler or a thermally conductive filler and using a branched siloxane unit (SiO) having a specific molecular weight range_4/2) The content of (2) is high, and the content of the curable functional group is small in the entire silicone component. By adopting such a configuration, even when a large amount of functional filler is blended, it is possible to provide a cured product in which flexibility and stress relaxation are not significantly impaired. The curable silicone composition of the present invention may be molded into a granular, particulate or sheet form, depending on the use thereof, and is preferably used. Hereinafter, each component will be described, and each component and an arbitrary component of the composition will be described. In the present invention, the "average particle diameter" refers to the primary average particle diameter of the particles, unless otherwise specified.

[ weight average molecular weight of polyorganosiloxane resin ]

The curable silicone composition is characterized by comprising SiO having a weight average molecular weight (Mw) in the range of 2000-15000 as measured by Gel Permeation Chromatography (GPC) using toluene as a solvent, and containing at least 20 mol% or more of all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown. The weight average molecular weight (Mw) of the polyorganosiloxane resin is preferably in the range of 2000 to 10000. On the other hand, if the weight average molecular weight (Mw) of the polyorganosiloxane resin exceeds the upper limit, when a large amount of the functional inorganic filler is blended, deterioration of melt characteristics, remarkable increase in hardness, embrittlement, and the like occur, and the technical problem of the present invention may not be solved. When the weight average molecular weight (Mw) of the polyorganosiloxane resin is less than the lower limit, the polyorganosiloxane resin becomes liquid at room temperature, and the resulting complex cannot be provided with a specific propertyAnd is excellent in hot melt property. That is, when a polyorganosiloxane resin having a molecular weight outside the above-mentioned weight average molecular weight (Mw) range is used, the technical effects of the present invention may not be achieved.

The polyorganosiloxane resin may also further contain R³SiO_1/2、R²SiO_2/2、RSiO_3/2Siloxane unit represented by (R is a monovalent organic group), R²O_1/2(R²Hydrogen atom or an alkyl group having 1 to 10 carbon atoms), preferably contains SiO in an amount of at least 40 mol% and particularly in an amount of 40 to 90 mol% based on the total siloxane units_4/2The siloxane units shown can be adjusted to SiO within the molecular weight range described above_4/2The amount of (c). SiO 2_4/2When the content of the siloxane units shown is less than the lower limit, even if other branched siloxane units (e.g., RSiO) are contained in a large amount_3/2) The technical effects of the present invention may not be achieved.

[ functional Filler ]

The curable silicone composition of the present invention contains one or more functional fillers. The functional filler is a component for imparting mechanical properties and other properties to a cured product, and examples thereof include: inorganic fillers, organic fillers, and mixtures thereof. Examples of the inorganic filler include: examples of the organic filler include reinforcing fillers, white pigments, thermally conductive fillers, electrically conductive fillers, phosphors, and mixtures of at least two thereof: a silicone resin filler, a fluororesin filler, and a polybutadiene resin filler. The shape of these fillers is not particularly limited, and may be spherical, spindle-shaped, flat, needle-shaped, amorphous, or the like. In particular, the curable silicone composition of the present invention is preferably used in a composition requiring a large amount of an inorganic filler to impart a function such as a thermally conductive filler, since the toughness and stress relaxation property of a cured product are not significantly impaired even when a large amount of a functional filler is added.

The kind and amount of the functional filler, and the surface treatment thereof will be described below.

[ vinyl content in composition ]

Specifically, the curable silicone composition of the present invention has a silicone component that is the sum of the components including the polyorganosiloxane resin and the chain polyorganosiloxane, and the content of a vinyl (CH2 ═ CH-) moiety in 100g of the curing reactive functional group including a carbon-carbon double bond, excluding the components other than the silicone component such as the functional filler, needs to be 0.05 to 1.50 mol%, preferably 0.05 to 1.25 mol%, and more preferably 0.05 to 1.00 mol%. Examples of the curing reactive functional group include: an alkenyl group having 2 to 20 carbon atoms and having a vinyl moiety in the functional group; and a monovalent organic group having an acryloyl group such as 3-methacryloxypropyl group and 3-acryloxypropyl group. By suppressing the content of these curing reactive functional groups, there is an advantage that even when a large amount of functional filler is blended in the composition, the stress relaxation property of the cured product is high.

[ Hot-melt Properties and constitution of curable Silicone composition ]

The curable silicone composition of the present invention is hot-melt as a whole, has a softening point of 50 ℃ or higher, has a melt viscosity at 150 ℃ (preferably a melt viscosity of less than 1000Pa · s), and has a fluid property. It is to be noted that individual components constituting the composition may not have a hot-melt property, and particularly when the curing reactive or non-reactive polyorganosiloxane resin is in a particulate form, it is particularly preferable not to have a hot-melt property at a temperature of 200 ℃.

The curable silicone composition of the present invention may be molded into a granular, particulate or sheet form, depending on the use thereof, and is preferably used. Hereinafter, each component will be described, and each component and an arbitrary component of the composition will be described. In the present invention, the "average particle diameter" refers to the primary average particle diameter of the particles, unless otherwise specified.

The curable silicone composition of the present invention is not limited in its composition as long as it contains at least the above components and has hot-melt properties as a whole composition, and in particular, it is preferable that the curable silicone composition contains: 100 parts by mass of (A) in a ratio of 0: 100-75: 25 in a mass ratio of (a1) to (a2) below, and a polyorganosiloxane resin having a weight average molecular weight (Mw) of (a1) to (a2) in the range of 2000 to 15000 as measured by Gel Permeation Chromatography (GPC) using toluene as a solvent:

the amount of (C) the curing agent required for curing of the present composition is one or more selected from the following (C1) or (C2):

(c1) organic peroxide,

(c2) An organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in the molecule and a hydrosilylation reaction catalyst; and

(D) a functional filler, wherein the functional filler is a functional filler,

(D) the amount of the component (A) is 10 to 2000 parts by mass based on 100 parts by mass of the sum of the components (A) and (B). The curable silicone composition of the present invention may optionally contain (E) hot-melt particles having a dropping point of 50 ℃ or higher and a melt viscosity of 10Pas or lower as measured by a rotational viscometer at 150 ℃, other additives, and the like.

The components and contents are explained below.

[ (A) component ]

The curable silicone composition of the invention contains SiO having no hot-melt property as a whole molecule and containing at least 20 mol% or more of all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown. The polyorganosiloxane resin may further contain R³SiO_1/2、R²SiO_2/2、RSiO_3/2Siloxane unit represented by (R is a monovalent organic group), R²O_1/2(R²Hydrogen atom or an alkyl group having 1 to 10 carbon atoms), preferably contains SiO in an amount of at least 40 mol% or more, 50 mol% or more, particularly 40 to 90 mol% of all siloxane units_4/2Siloxane units as shown. In SiO_4/2When the content of the siloxane units shown is less than the lower limit, even if other branched siloxane units (e.g., RSiO) are contained in a large amount_3/2) The technical effects of the present invention may not be achieved.

The polyorganosiloxane resin is required to have a weight average molecular weight (Mw) in the range of 2000 to 15000 as measured by Gel Permeation Chromatography (GPC) using toluene as a solvent, as described above. In addition, volatile components generated in the production process can be removed at will. The degree of removal is synonymous with the mass reduction rate at 200 ℃ for 1 hour, and in order to make the mass reduction rate 2.0 mass% or less, it is particularly preferable to remove volatile low-molecular-weight components from the polyorganosiloxane resin.

Such organopolysiloxanes can be defined as polyorganosiloxane resins as follows:

and (3) adding the following components in a ratio of 0: 100-75: 25 comprises (A1) and (A2),

(A2) not hot-melt as a whole molecule, not intra-moleculeSiO having a curing-reactive functional group containing a carbon-carbon double bond and containing at least 20 mol% or more of all siloxane units_4/2The polyorganosiloxane resin having siloxane units as shown, wherein the weight average molecular weight (Mw) of the component (A1) and the component (A2) is in the range of 2000-15000 as measured by Gel Permeation Chromatography (GPC) using toluene as a solvent. The component (a1) may be any of the components (a), and only the component (a2) described later may be used as the component (a).

The component (a) does not have a heat-fusible property as a whole molecule, and can be used in combination with the component (B) described later in a predetermined amount range to realize a heat-fusible property of the whole composition. The component (A) is preferably used alone or together with other components in the form of fine particles, and in this case, it is particularly preferably spherical silicone fine particles having an average primary particle diameter of 1 to 20 μm.

[ (A1) polyorganosiloxane resin having curing-reactive functional group ]

(A1) The component (A) is one of the main agents of the composition, and contains SiO with at least 20 mol% of all siloxane units_4/2The siloxane units are polyorganosiloxane resins having no hot-melt property alone and a curing reactive functional group containing a carbon-carbon double bond in the molecule, and the weight loss rate when exposed to 200 ℃ for 1 hour is 2.03.0 mass% or less.

(A1) The component needs to have a curing reactive group containing a carbon-carbon double bond in the molecule. Such a curing reactive group is a functional group that is hydrosilylation-reactive or curable by an organic peroxide, and forms a cured product by a crosslinking reaction with another component. Such a curing reactive group is an alkenyl group or an acryloyl group, and examples thereof include: alkenyl groups having 2 to 10 carbon atoms such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl and the like; an acryloyl group-containing monovalent organic group such as 3-methacryloxypropyl group and 3-acryloxypropyl group, and particularly, a vinyl group or hexenyl group is preferable.

(A1) The component (A) is a solid polymer having no hot-melt property as a whole molecule and in a solvent-free stateAn organosiloxane resin. Herein, the term "not having a hot melt property" means that the resin alone as the component (a1) does not show a heating melting behavior at 200 ℃ or lower, and specifically means that the resin does not have a softening point and a melt viscosity at 200 ℃ or lower. In the component (A1), the physical properties are not particularly limited in structure, but the functional group in the polyorganosiloxane resin is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, particularly a functional group selected from alkyl groups having 1 to 10 carbon atoms such as methyl groups, and does not substantially contain an aryl group such as a phenyl group. When a large amount of phenyl group or the like is contained, the component may be hot-melt, and SiO may be present_4/2The effect of reinforcing the cured product peculiar to the group is reduced.

Preferably, the functional group bonded to the silicon atom in component (a1) is a group selected from alkenyl groups such as methyl and vinyl groups, preferably 70 to 99 mol%, more preferably 80 to 99 mol%, particularly preferably 88 to 99 mol% of the functional groups bonded to all silicon atoms are methyl groups, and the functional group bonded to other silicon atoms is alkenyl groups such as vinyl groups. Within this range, the component (A1) is not hot-melt, and can be designed to have particularly excellent resistance to coloration at high temperatures of the cured product. The component (a1) may contain a small amount of a hydroxyl group or an alkoxy group.

(A1) Component (B) is a polyorganosiloxane resin which is solid in the absence of a solvent and contains SiO in an amount of at least 20 mol% based on all siloxane units in the molecule_4/2Siloxane units as shown. These branched siloxane units are preferably at least 40 mol% or more, particularly preferably in the range of 40 to 90 mol% of all siloxane units. In addition, R is a monovalent organic group, preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, particularly a functional group selected from an alkyl group and an alkenyl group having 1 to 10 carbon atoms such as a methyl group, and it is preferable that R does not substantially contain an aryl group such as a phenyl group from the viewpoint of technical effects.

Preferably, the component (A1) is (A1-1) a non-hot-melt polyorganosiloxane resin represented by the following average unit formula.

(R¹ ₃SiO_1/2)_a(R¹ ₂SiO_2/2)_b(R¹SiO_3/2)_c(SiO_4/2)_d(R²O_1/2)_e

(wherein each R is¹Independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, wherein all R in one molecule¹1 to 12 mol% of (a) is an alkenyl group; each R²Is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; a. b, c, d and e are numbers satisfying the following: a is more than or equal to 0.10 and less than or equal to 0.60, b is more than or equal to 0 and less than or equal to 0.70, c is more than or equal to 0 and less than or equal to 0.80, d is more than or equal to 0 and less than or equal to 0.65, e is more than or equal to 0 and less than or equal to 0.05, wherein c + d>0.20, and a + b + c + d ═ 1)

In the above average unit formula, each R¹Independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, or similar alkyl groups; vinyl, allyl, butenyl, pentenyl, hexenyl, or similar alkenyl groups; phenyl, tolyl, xylyl, or similar aryl groups; benzyl, phenethyl, or similar aralkyl groups; and chloromethyl, 3-chloropropyl, 3,3, 3-trifluoropropyl, or a similar haloalkyl group, etc. Furthermore, all R in one molecule¹1 to 12 mol% of (A) is an alkenyl group, preferably all R in one molecule¹2 to 10 mol% of the alkenyl group is an alkenyl group. When the alkenyl group content is less than the lower limit of the above range, the mechanical strength (hardness, etc.) of the obtained cured product may become insufficient. On the other hand, if the alkenyl group content is not more than the upper limit of the range, the composition containing the present component can achieve good hot melt properties as a whole of the composition. In addition, each R¹Preferably a functional group selected from an alkyl group having 1 to 10 carbon atoms such as a methyl group and an alkenyl group such as a vinyl group or a hexenyl group, and R is R from the viewpoint of technical effects of the present invention¹Preferably, the aromatic group such as a phenyl group is not substantially contained. When a large amount of aryl groups such as phenyl groups are contained, the component (a) itself is hot-melt, and the technical effects of the present invention may not be achieved_4/2The effect of reinforcing the cured product peculiar to the group is reduced.

In the formula, R²Is an alkyl group having a hydrogen atom or 1 to 10 carbon atoms. R²The alkyl groups of (a) are exemplified by methyl, ethyl, propyl, butyl, pentyl or hexyl. Comprising said R²Functional group R of²O_1/2Corresponds to the hydroxyl or alkoxy in the component (A).

Wherein a is represented by the general formula R¹ ₃SiO_1/2Number of siloxane units of (a). The number satisfies 0.1. ltoreq. a.ltoreq.0.60, preferably 0.15. ltoreq. a.ltoreq.0.55. When a is not less than the lower limit of the above range, the composition containing the present component can realize good hot melt properties as a whole. On the other hand, if a is not more than the upper limit of the above range, the mechanical strength (hardness, elongation, etc.) of the obtained cured product does not become too low.

In the formula, b is represented by the general formula R¹ ₂SiO_2/2Number of siloxane units of (a). The number satisfies 0. ltoreq. b.ltoreq.0.70, preferably 0. ltoreq. b.ltoreq.0.60. When b is not more than the upper limit of the range, the composition containing the present component can realize good hot melt performance as the whole composition, and a granular composition which is less tacky at room temperature can be obtained.

Wherein c is represented by the general formula: r³SiO_3/2Number of siloxane units of (a). The number satisfies 0 ≦ c ≦ 0.80, preferably 0 ≦ c ≦ 0.75. When c is not more than the upper limit of the range, the composition containing the component can realize good hot melt performance as the whole composition, and can obtain a composition which is less tacky at room temperature and is free from tackiness. In the present invention, c may be 0, and is preferable.

Wherein d represents SiO_4/2The number of the proportion of the siloxane units (C) is preferably 0.00. ltoreq. d.ltoreq.0.65, more preferably 0.20. ltoreq. d.ltoreq.0.65, particularly preferably 0.25. ltoreq. d.ltoreq.0.65. This is because, within the above numerical range, the composition containing the component can realize good hot-melt properties as a whole composition, and the resulting cured product has sufficient flexibility.

In the present invention, c or d may be 0, but c + d >0.20 is required. When the value of c + d is less than the lower limit, the composition as a whole may not exhibit good hot-melt properties, and the technical effects of the present invention may not be sufficiently exhibited.

Wherein e is represented by the general formula R²O_1/2The number of the proportion of the unit (b) refers to a hydroxyl group or an alkoxy group bonded to a silicon atom which may be contained in the polyorganosiloxane resin. The number satisfies 0. ltoreq. e.ltoreq.0.05, preferably 0. ltoreq. e.ltoreq.0.03. When e is not more than the upper limit of the range, a material which realizes good hot-melt performance as the whole composition can be obtained. Finally, the total of a, b, c and d, which is the sum of the siloxane units, is equal to 1.

(A1) The polyorganosiloxane resin having the above-mentioned characteristics as the component (A), is preferably a regular spherical polyorganosiloxane resin fine particle having an average primary particle diameter of 1 to 20 μm as measured by a laser diffraction/scattering method or the like from the viewpoint of handling properties. By using the fine particle component, the present composition can be prepared or produced into a curable granular composition excellent in workability and hot-melt property. The method for producing the component (a1) is not limited, and a known method can be used.

Examples of the method for producing the fine particulate component (a1) include: the polyorganosiloxane resin is pulverized by a pulverizer, or directly pulverized in the presence of a solvent. The pulverizer is not limited, and examples thereof include: roll mills, ball mills, jet mills, turbine mills, planetary mills. Further, as a method for directly microparticulating the polyorganosiloxane resin in the presence of a solvent, for example, there are mentioned: spraying with a spray dryer; or micronizing with a twin-screw kneader or a belt dryer. When the component (a1) is obtained in the form of fine particles, a part of the component (C) described later, for example, a hydrosilylation catalyst, may be formed into fine particles together with the component (a1), and it is not preferable to form fine particles of a mixture having a property of being cured by heating from the viewpoint of storage stability of the obtained composition.

In particular, the component (A1) having a regular spherical shape and an average primary particle diameter of 1 to 500 μm, preferably 1 to 20 μm can be produced by using a spray dryer or the like. The heating/drying temperature of the spray dryer needs to be appropriately set based on the heat resistance of the polyorganosiloxane resin fine particles and the like. In order to prevent secondary aggregation of the resulting fine particles, it is preferable to control the temperature of the polyorganosiloxane resin fine particles to be not higher than the glass transition temperature thereof. The polyorganosiloxane resin fine particles thus obtained can be recovered by a cyclone (cyclone), a bag filter (bag filter) or the like.

In the above-mentioned fine particles, a solvent may be used in a range not interfering with the curing reaction. The solvent is not limited, and examples thereof include: aliphatic hydrocarbons such as n-hexane, cyclohexane, and n-heptane; aromatic hydrocarbons such as toluene, xylene, mesitylene (mesitylene), and the like; ethers such as tetrahydrofuran and dipropyl ether; silicones such as hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, and the like; esters such as ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[ (A2) ingredient ]

(A2) The component (a) is one of the main components of the present composition, is a polyorganosiloxane resin containing a curing reactive functional group which does not have a hot-melt property alone, and is a component which realizes a hot-melt property as a whole of the composition and a coloring resistance of a cured product by using the component (a1) and the component (B) in a predetermined amount range in combination. The component (A2) is also preferably in the form of fine particles, either alone or in combination with other components (e.g., component (A1) which is a non-reactive polyorganosiloxane resin, and part of component (C) which is a curing agent), and particularly preferably in the form of spherical silicone fine particles having an average primary particle diameter of 1 to 20 μm.

(A2) The component (A) is a polyorganosiloxane resin which is solid in a solvent-free state and does not have hot-melt property as a whole molecule. Here, the term "not having a hot melt property" means that the resin alone as the component (a2) does not show a heating melting behavior, and specifically means that the resin does not have a softening point and a melt viscosity. In the component (A2), the physical properties are not particularly limited in structure, but the functional group in the polyorganosiloxane resin is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, particularly a carbon atom selected from methyl group and the likeThe functional group in the alkyl group having 1 to 10 atoms does not substantially contain an aryl group such as a phenyl group. When a large amount of phenyl group or the like is contained, the component may be hot-melt, and SiO may be present_4/2The effect of reinforcing the cured product peculiar to the group is reduced.

(A2) Component (A) is a solid as in component (A1), and is characterized by containing at least 20 mol% or more of SiO based on all siloxane units_4/2The polyorganosiloxane resin particles of siloxane units have no curing reactive functional group containing at least one carbon-carbon double bond in the molecule. That is, the component (a2) is characterized by not containing an alkenyl group such as a vinyl group as a functional group in the polyorganosiloxane resin. Examples of the functional group in the polyorganosiloxane include: a monovalent hydrocarbon group having 1 to 10 carbon atoms, particularly an alkyl group having 1 to 10 carbon atoms such as a methyl group, preferably containing substantially no aryl group such as a phenyl group.

The functional group bonded to the silicon atom in component (a2) is preferably an alkyl group having 1 to 10 carbon atoms such as a methyl group, and 70 to 100 mol%, more preferably 80 to 100 mol%, and particularly preferably 88 to 100 mol% of the functional groups bonded to all silicon atoms are methyl groups. In this range, the (A2) component can be designed not to be hot-melt, and contains SiO_4/2The cured product of the siloxane unit has a particularly excellent reinforcing effect. The component (a2) may contain a small amount of a hydroxyl group or an alkoxy group.

(A2) The component (a) does not have a curing reactive group containing a carbon-carbon double bond in the molecule, and therefore does not form a cured product by itself, but has an effect of improving the hot-melt property as the whole composition and a reinforcing effect on the cured product. Further, the component is a component necessary for achieving the technical effect of the present invention by being used in combination with the (a1) component having a curing reactive group, as necessary.

(A2) Component (B) is a polyorganosiloxane resin which is solid in the absence of a solvent and contains SiO as a branched siloxane unit in an amount of at least 20 mol% based on all siloxane units in the molecule_4/2Siloxane units as shown. Preference is given toThe branched siloxane unit is at least 40 mol% or more and 50 mol% or more of all siloxane units, and particularly preferably in the range of 50 to 65 mol%.

Preferably, the component (A2) is (A2-1) a non-hot-melt polyorganosiloxane resin represented by the following average unit formula.

(R³ ₃SiO_1/2)_f(R³ ₂SiO_2/2)_g(R³SiO_3/2)_h(SiO_4/2)_i(R²O_1/2)_j

(wherein each R is³Independently a monovalent hydrocarbon group having 1 to 10 carbon atoms and containing no carbon-carbon double bond; r2 is an alkyl group having a hydrogen atom or 1 to 10 carbon atoms; f. g, h, i and j are numbers satisfying the following: f is more than or equal to 0.35 and less than or equal to 0.55, g is more than or equal to 0 and less than or equal to 0.20, h is more than or equal to 0.45 and less than or equal to 0.65, j is more than or equal to 0 and less than or equal to 0.05, and f + g + h + i is equal to 1)

In the above average unit formula, each R³Independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, which does not contain a carbon-carbon double bond, such as a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, or the like; phenyl, tolyl, xylyl, or similar aryl groups; benzyl, phenethyl, or similar aralkyl groups; and chloromethyl, 3-chloropropyl, 3,3, 3-trifluoropropyl, or a similar haloalkyl group, etc. Here, all R in one molecule are preferred³70 mol% or more of (B) is an alkyl group having 1 to 10 carbon atoms such as a methyl group, and from the viewpoint of industrial production and the technical effect of the present invention, 88 mol% or more is particularly preferably a methyl group. In another aspect, R³Preferably, the aromatic group such as a phenyl group is not substantially contained. When a large amount of aryl groups such as phenyl groups are contained, the component (B) itself becomes hot-melt, and the technical effects of the present invention may not be achieved.

In the formula, R²Are the same groups as described above.

Wherein f is represented by the general formula R³ ₃SiO_1/2Number of siloxane units of (a). The number satisfies 0.35. ltoreq. f.ltoreq.0.55, preferably 0.40. ltoreq. a.ltoreq.0.50. If f is not less than the lower limit of the above range, the composition containing the present component can realize good hot melt properties as a whole. On the other hand, if f is not more than the upper limit of the above range, the mechanical strength (hardness, etc.) of the resulting cured product does not become excessively low.

Wherein g is represented by the general formula R¹ ₂SiO_2/2Number of siloxane units of (a). The number satisfies 0. ltoreq. g.ltoreq.0.20, preferably 0. ltoreq. g.ltoreq.0.10. When g is not more than the upper limit of the range, the composition containing the present component can realize good hot melt performance as the whole composition and can obtain a composition which is less tacky at room temperature. In the present invention, g may be 0, and is preferable.

In the formula, h is represented by the general formula R¹SiO_3/2Number of siloxane units of (a). The number satisfies 0. ltoreq. h.ltoreq.0.20, preferably 0. ltoreq. h.ltoreq.0.10. When h is not more than the upper limit of the range, the composition containing the present component can realize good hot melt performance as the whole composition and can obtain a composition which is less tacky at room temperature. In the present invention, h may be 0, and is preferable.

Wherein i is SiO_4/2The number of siloxane units of (b) is desirably 0.45. ltoreq. i.ltoreq.0.65, preferably 0.40. ltoreq. i.ltoreq.0.65, particularly preferably 0.50. ltoreq. i.ltoreq.0.65. Within this range, the composition containing the component can exhibit good hot-melt properties as the whole composition, and the resulting cured product has excellent mechanical strength, and can realize a composition which is free from tackiness and has good workability as the whole composition.

Wherein j is represented by the general formula R²O_1/2The number of the proportion of the unit (b) refers to a hydroxyl group or an alkoxy group bonded to a silicon atom which may be contained in the polyorganosiloxane resin. The number satisfies 0. ltoreq. j.ltoreq.0.05, preferably 0. ltoreq. j.ltoreq.0.03. When e is not more than the upper limit of the range, a material which realizes good hot-melt performance as the whole composition can be obtained. Finally, the sum of e, f, g and h, which is the sum of the siloxane units, is equal to 1.

(A2) The polyorganosiloxane resin having the above-mentioned characteristics as the component (A), is preferably a regular spherical polyorganosiloxane resin fine particle having an average primary particle diameter of 1 to 20 μm as measured by a laser diffraction/scattering method or the like from the viewpoint of handling properties. By using the fine particle component, the present composition can be prepared or produced into a curable granular composition excellent in workability and hot-melt property. Examples of the method for producing the component (a2) include the same methods as those exemplified for the component (a 1). [ (removal of volatile Low molecular weight component in component A) ]

(A1) Component (a2) generates a volatile low-molecular-weight component in the production process. In particular M₄The structure of Q consists of M units (R)³ ₃SiO_1/2) And Q unit (SiO)_4/2) The polyorganosiloxane resin of the composition is produced as a by-product when the polyorganosiloxane resin is polymerized. The present structure has an effect of remarkably reducing the hardness of a cured product formed from the composition of the present invention. The polyorganosiloxane resin is polymerized in the presence of an organic solvent having high compatibility, and the organic solvent is removed by drying under reduced pressure to obtain an individual polyorganosiloxane resin, except that M₄The structure of Q and the polyorganosiloxane resin have high mutual solubility and cannot be removed under drying conditions such as removal of an organic solvent. It is known that the structure can be removed by exposure to a temperature of 200 ℃ or higher for a short time, but when the structure is removed by exposure to a high temperature after being integrally molded with a base material such as a semiconductor, a volume reduction and a significant increase in hardness of a cured product occur, and a dimensional change of a molded product causes warpage or the like. Therefore, for the use of the present invention, it is necessary to remove M before the molding step with the base material, that is, at the time point of the raw material in advance₄A structure of Q.

Examples of the method for removing the structure include: a method of removing the organic solvent together with the organic solvent in a twin-screw kneader; a method in which a polyorganosiloxane resin is prepared in a particle form by the method described later, and then dried in an oven or the like to remove the polyorganosiloxane resin.

More specifically, the component (a1) and the component (a2) are produced in the presence of an organic solvent, and volatile components appear as by-products in the synthesis. Since volatile components can be removed by treating the obtained polyorganosiloxane resin as a crude raw material at a high temperature of about 200 ℃ for a short time, the organic solvent and volatile components can be simultaneously removed from the component (a1) and the component (a2) by a twin-screw kneader or the like set at about 200 ℃. In the case of processing the component (a1) and the component (a2) into spherical powder, the powder can be made by removing the organic solvent by a spray dryer, but this method cannot remove volatile components. When the obtained powder is treated at a low temperature of about 120 ℃ for 24 hours, volatile components can be removed without causing the powder to coagulate.

[ (mass ratio of (A1) component to (A2) component in (A) ]

In order to impart hot melt properties to the entire composition, it is necessary to mix the component (a2) or a mixture of the component (a1) and the component (a2) with the component (B) described later at a predetermined ratio, and the ratio of the component (a) to the component (B) may be 0: 100-75: 25, preferably in the range of 0: 100-60: 40, more preferably 0: 100-55: 45. (A2) the component (a) does not have curability, but when a small amount of the component (a1) is added to the present composition and used together, the elastic modulus at high temperatures of a cured product formed from the present composition can be controlled, and when a functional inorganic filler described later is added to the present composition, the amount of the component (a) added and the amount of the component (a1) used are appropriately adjusted, whereby preferable elastic modulus and flexibility can be achieved. For example, when the amount of the functional inorganic filler to be added is large, or when the elastic modulus of the resulting cured product is intended to be reduced as much as possible, the composition may be blended from only the component (a2) without adding the component (a 1).

[ (B) component ]

(B) The component (A) is one of the main agents of the composition, is a linear or branched polyorganosiloxane which is liquid at 25 ℃, and has at least two curing reactive functional groups containing carbon-carbon double bonds in the molecule. Such a curing-reactive chain polyorganosiloxane exhibits hot-melt properties as a whole composition by being mixed with the solid polyorganosiloxane resin.

(B) The component (a) needs to have a curing reactive group containing a carbon-carbon double bond in the molecule, and such a curing reactive group is a functional group which is hydrosilylation reactive or curable by an organic peroxide, and forms a cured product by a crosslinking reaction with other components. Such a curing reactive group is an alkenyl group or an acryloyl group, and the same groups as those described above are exemplified, and in particular, a vinyl group or a hexenyl group is preferable.

(B) The component (A) is a linear or branched polyorganosiloxane which is liquid at 25 ℃ (room temperature), and when mixed with the component (A) which is solid at room temperature, the hot melt property is exhibited as the whole composition. The structure may be a siloxane unit with few branches (e.g., formula R)⁴SiO_3/2T units (R) as shown⁴Independently a monovalent hydrocarbon group having 1 to 10 carbon atoms) or SiO_4/2A Q unit) in the molecule,

preferably, (B1) a linear polydiorganosiloxane represented by the following structural formula.

R⁴ ₃SiO(SiR⁴ ₂O)_kSiR⁴ ₃

In the formula, each R⁴Independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, wherein R in one molecule⁴At least two of (a) are alkenyl groups, and k is a number of 20 to 5000.

Preferably, the silicone polymer is a linear polydiorganosiloxane having one alkenyl group at each of both ends of the molecular chain.

In the formula, each R⁴Independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, or similar alkyl groups; vinyl, allyl, butenyl, pentenyl, hexenyl, or similar alkenyl groups; phenyl, tolyl, xylyl, or similar aryl groups; benzyl, phenethyl, or similar aralkyl groups; and chloromethyl, 3-chloropropyl, 3,3, 3-trifluoropropyl, or a similar haloalkyl group, etc. And, R in one molecule⁴At least two of (a) are alkenyl groups, preferably vinyl groups. Furthermore, each R⁴Preferably a functional group selected from an alkyl group having 1 to 10 carbon atoms such as a methyl group and an alkenyl group such as a vinyl group and a hexenyl group, and preferably all R⁴At least two of which are alkenyl radicals, the remainder being R⁴Is methyl. In view of the technical effects of the present invention, R⁴Preferably, the aromatic group such as a phenyl group is not substantially contained. When a large amount of aryl groups such as phenyl groups are contained, the coloring resistance of the cured product at high temperature may be deteriorated. Particularly preferably, the polymer has one alkenyl group such as a vinyl group and the other R group at each terminal of the molecular chain⁴Is methyl.

Wherein k is 20 to 5000, preferably 100 to 3000, and particularly preferably 300 to 1500. When k is not less than the lower limit of the above range, a composition having low tackiness at room temperature can be obtained. On the other hand, when k is not more than the upper limit of the above range, good hot melt properties can be achieved as the whole composition. The component (B) is preferably selected from the above-mentioned chain polyorganosiloxanes having a high polymerization degree and a high molecular weight and having curing reactivity. This is because, when the component (B) having a low molecular weight is used, even if the component (a) is used, the toughness and stress relaxation of the obtained cured product tend to be low depending on the type and amount of the functional filler, and therefore, when the amount of the functional inorganic filler is very large, the cured product may be significantly embrittled. Therefore, when a large amount of inorganic filler is blended in the curable silicone composition, it is preferable to combine the polyorganosiloxane resin (a) having the above molecular weight range with the component (B) having a relatively high molecular weight in order to prevent the cured product from having high hardness and embrittlement.

In order to achieve hot-melt properties of the entire composition, the mass ratio of the component (B) which is a linear or branched polyorganosiloxane to 100 parts by mass of the component (a) which is a polyorganosiloxane resin is in the range of 10 to 100 parts by mass, preferably 10 to 70 parts by mass, and more preferably 15 to 50 parts by mass. When the content of the component (B) is within the above range, the composition can realize good hot-melt properties, increase the mechanical strength of the obtained cured product, and reduce tackiness at room temperature of the obtained composition, thereby improving the workability.

[ (C) ingredient ]

(C) The component (c) is a curing agent for curing the above-mentioned components (a) and (B), and specifically is at least one curing agent selected from the following (c1) and (c 2). Two or more of these curing agents may be used in combination, and for example, a curing system containing both the component (c1) and the component (c2) may be used.

(c1) Organic peroxide,

(c2) An organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in the molecule and a hydrosilylation reaction catalyst; and

(c1) the organic peroxide is a component which cures the above-mentioned components (a) and (B) by heating, and examples thereof include: alkyl peroxides, diacyl peroxides, peroxyesters, and peroxycarbonates. The component (c1) may be a reaction product of a part of the component (A2).

Examples of the alkyl peroxide include: dicumyl peroxide, di-tert-butyl peroxide, di-tert-butylcumyl peroxide, 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane, 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexyne-3, tert-butylcumyl benzene, 1, 3-bis (tert-butylperoxyisopropyl) benzene, 3,6, 9-triethyl-3, 6, 9-trimethyl-1, 4, 7-triperoxonane.

Examples of diacyl peroxides include: benzoyl peroxide, lauroyl peroxide, decanoyl peroxide.

Examples of the peroxyesters include: 1,1,3, 3-tetramethylbutyl peroxyneodecanoate, alpha-isopropylphenyl peroxyneodecanoate, tert-butyl peroxyneoheptanoate, tert-butyl peroxypivalate, tert-hexyl peroxypivalate, 1,3, 3-tetramethylbutyl peroxy2-ethylhexanoate, tert-amyl peroxy2-ethylhexanoate, tert-butyl peroxyisobutyrate, di-tert-butyl peroxycyclohexanedicarboxylate, tert-amyl peroxy3, 5, 5-trimethylhexanoate, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, and dibutyl trimethylhexanoate.

Examples of the peroxycarbonates include: di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, diisopropyl peroxycarbonate, tert-butylisopropyl peroxydicarbonate, di-4-tert-butylcyclohexyl peroxydicarbonate, dicetyl peroxydicarbonate, and dimyristyl peroxydicarbonate.

The organic peroxide preferably has a half-life of 10 hours at a temperature of 90 ℃ or higher, or 95 ℃ or higher. Examples of such organic peroxides include: dicumyl peroxide, di-tert-butyl peroxide, di-tert-hexyl peroxide, tert-butylcumyl peroxide, 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane, 1, 3-bis (tert-butylperoxyisopropyl) benzene, di (2-tert-butylperoxyisopropyl) benzene, 3,6, 9-triethyl-3, 6, 9-trimethyl-1, 4, 7-triperoxonane.

(c1) The content of the organic peroxide is not limited, but is preferably in the range of 0.05 to 10 parts by mass or 0.10 to 5.0 parts by mass based on the total (100 parts by mass) of the components (A) and (B).

(c2) The organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in the molecule and the hydrosilylation reaction catalyst are components which cure the composition by an addition reaction (hydrosilylation reaction) of the organohydrogenpolysiloxane as a crosslinking agent with carbon-carbon double bonds in the component (a) and the component (C) in the presence of the hydrosilylation reaction catalyst.

The structure of the organohydrogenpolysiloxane as the crosslinking agent is not particularly limited, and may be linear, branched, cyclic or resinous. That is, the component (d2) may be an organohydrogenpolysiloxane as follows: with HR₂SiO_1/2An organohydrogensiloxy unit (D) shown^HUnit, R is independently a monovalent organic group) as a main structural unit, and has HR at the terminal thereof₂SiO_1/2The shown diorganohydrogensiloxy unit (M)^HUnit, R is independently a monovalent organic group). Particularly, in the case of applications other than the molding step described laterEven if the curable silicone composition is composed of D^HThe chain organohydrogenpolysiloxane composed of units and the like can be cured sufficiently in practical use.

On the other hand, when the curable silicone composition is used in a molding step, the content of the curing reactive functional group containing a carbon-carbon double bond in the composition is small, and therefore, from the viewpoint of curing speed, moldability thereof, and curability, the organohydrogenpolysiloxane is preferably: comprising RSiO_3/2The monoorganosilalkoxy units shown (T units, R being a monovalent organic radical or a silicon atom bonded to a hydrogen atom) or as SiO_4/2A branched unit of the siloxy unit (Q unit) and having at least two HR units in the molecule₂SiO_1/2The shown diorganohydrogensiloxy unit (M)^HUnit, R is independently a monovalent organic group), and has MH unit at the molecular terminal.

Particularly preferred organohydrogenpolysiloxanes are organohydrogenpolysiloxane resins represented by the following average unit formula.

(R⁵ ₃SiO_1/2)_l(R⁶ ₂SiO_2/2)_m(R⁶SiO_3/2)_n(SiO_4/2)_p(R²O_1/2)_q

In the formula, each R⁵The same or different, and is a C1-10 monovalent hydrocarbon group or hydrogen atom having no aliphatic unsaturated carbon bond, wherein at least two R in one molecule⁵Is a hydrogen atom. As R other than hydrogen atom⁵Monovalent hydrocarbon groups of (a) are, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or similar alkyl groups; phenyl, tolyl, xylyl, or similar aryl groups; benzyl, phenethyl or similar aralkyl groups; and chloromethyl, 3-chloropropyl, 3,3, 3-trifluoropropyl, or a similar haloalkyl group, and the like. From the industrial viewpoint, a methyl group or a phenyl group is preferable.

In the formula, R⁶Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms and having no aliphatic unsaturated carbon bond include those described aboveThe monovalent hydrocarbon groups are the same groups. In another aspect, R²Examples of the hydrogen atom or the alkyl group having 1 to 10 carbon atoms include the group represented by R in the above-mentioned component (A1) or component (A2)²The same groups.

Wherein l, m, n and p are numbers satisfying the following: 0.1 ≦ l ≦ 0.80, 0 ≦ m ≦ 0.5, 0 ≦ n ≦ 0.8, 0 ≦ p ≦ 0.6, 0 ≦ q ≦ 0.05, where n + p>0.1 and l + m + n + p ═ 1. When the present composition is used in the molding step, the organohydrogenpolysiloxane resin which is a part of the component (d2) is preferably M^HMT resin, M^HMTT^HResin, M^HMTQ resin, M^HMQ resin, M^HMTT^HQ and M^HAnd (3) resin Q.

It is particularly preferable that the organohydrogenpolysiloxane as part of the component (c2) is M represented by the following formula^HAnd (3) resin Q.

(H(CH₃)₂SiO_1/2)_l1(SiO_4/2)_p1

Here, l1+ p1 is 1, preferably 0.1 ≦ l1 ≦ 0.80 and 0.20 ≦ p1 ≦ 0.90.

Similarly, the organohydrogenpolysiloxane as a part of component (c2) may include a linear diorganosiloxane, organohydrogenpolysiloxane, or diorganosiloxane-organohydrogensiloxane copolymer, in which the molecular chain terminals are terminated with silicon atom-bonded hydrogen atoms or trimethylsiloxy groups. The degree of polymerization of siloxane of these linear organohydrogenpolysiloxanes is not particularly limited, but is within the range of 2 to 200, preferably within the range of 5 to 100.

The content of the organohydrogenpolysiloxane as part of the component (C2) is an amount sufficient for curing the curable silicone composition of the present invention, and is an amount such that the molar ratio of silicon atom-bonded hydrogen atoms in the organohydrogenpolysiloxane is 0.5 or more, preferably in the range of 0.5 to 20, relative to the curing reactive functional group (e.g., alkenyl group such as vinyl group) containing a carbon-carbon double bond in the components (B) and (C). In particular, when the component (d2) contains the aforementioned organohydrogenpolysiloxane resin, the molar ratio of silicon atom-bonded hydrogen atoms in the organohydrogenpolysiloxane resin is preferably in the range of 0.5 to 20 or in the range of 1.0 to 10 relative to the curing reactive functional groups containing carbon-carbon double bonds in the components (B) and (C).

Examples of the catalyst for hydrosilylation reaction as part of the component (c2) include: platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts are preferred because they can significantly accelerate the curing of the present composition. Examples of the platinum-based catalyst include: platinum fine powder, chloroplatinic acid, alcohol solutions of chloroplatinic acid, platinum-alkenylsiloxane complexes, platinum-olefin complexes, platinum-carbonyl complexes, and catalysts obtained by dispersing or encapsulating these platinum catalysts with a thermoplastic resin such as silicone resin, polycarbonate resin, or acrylic resin, with platinum-alkenylsiloxane complexes being particularly preferred. Examples of the alkenylsiloxane include: 1, 3-divinyl-1, 1,3, 3-tetramethyldisiloxane, 1,3,5, 7-tetramethyl-1, 3,5, 7-tetravinylcyclotetrasiloxane, alkenylsiloxanes in which some of the methyl groups of these alkenylsiloxanes are substituted with ethyl groups, phenyl groups, etc., alkenylsiloxanes in which the vinyl groups of these alkenylsiloxanes are substituted with allyl groups, hexenyl groups, etc. In particular, from the viewpoint of good stability of the platinum-alkenylsiloxane complex, 1, 3-divinyl-1, 1,3, 3-tetramethyldisiloxane is preferable, and it is preferable to add the platinum-alkenylsiloxane complex in the form of an alkenylsiloxane solution. In addition, from the viewpoint of improving workability and pot life of the composition, a particulate platinum-containing hydrosilylation reaction catalyst dispersed or encapsulated by a thermoplastic resin may also be used. As the catalyst for promoting the hydrosilylation reaction, a non-platinum metal catalyst such as iron, ruthenium, iron/cobalt, or the like can be used.

The amount of the hydrosilylation catalyst as part of the component (c2) is preferably in the range of 0.01 to 500ppm, 0.01 to 100ppm, or 0.01 to 50ppm, in terms of mass unit, of metal atoms relative to the entire composition.

The particularly preferred component (c2) contains at least (c2-1) the organohydrogenpolysiloxane resin represented by the average unit formula and a hydrosilylation reaction catalyst.

When the hydrosilylation catalyst is used as part of component (C), it is preferable that the particles be contained in advance in the production of polyorganosiloxane resin particles such as component (a1) and component (a2) from the viewpoint of the storage stability of the curable silicone composition. Among them, it is preferable that the whole mixture constituting the fine particles alone is not rendered curing reactive.

[ (D) component ]

The functional filler as the component (D) is an essential component of the present invention, and examples of the component for imparting mechanical properties and other properties to a cured product include: inorganic fillers, organic fillers, and mixtures thereof. Examples of the inorganic filler include: examples of the organic filler include reinforcing fillers, white pigments, thermally conductive fillers, electrically conductive fillers, phosphors, and mixtures of at least two thereof: a silicone resin filler, a fluororesin filler, and a polybutadiene resin filler. The shape of these fillers is not particularly limited, and may be spherical, spindle-shaped, flat, needle-shaped, amorphous, or the like.

When the present composition is used for applications such as an encapsulant, a protective agent, and an adhesive, it is preferable that the component (D) contains a reinforcing filler in at least a part thereof from the viewpoint of improving the mechanical strength, the protective property, and the adhesive property of a cured product.

The reinforcing filler may be added as a binder filler for the curable silicone composition before curing for the purpose of maintaining the solid particle state, in addition to improving the mechanical strength of the cured product and improving the protection and adhesion. Examples of such reinforcing fillers include: fumed silica, precipitated silica, fused silica, calcined silica, fumed titanium dioxide, quartz, calcium carbonate, diatomaceous earth, alumina, aluminum hydroxide, zinc oxide, zinc carbonate. Further, as these reinforcing fillers, organoalkoxysilanes such as methyltrimethoxysilane; organohalosilanes such as trimethylchlorosilane; organic silazanes such as hexamethyldisilazane; and a siloxane oligomer such as an α, ω -silanol group-terminated dimethylsiloxane oligomer, an α, ω -silanol group-terminated methylphenylsiloxane oligomer, and an α, ω -silanol group-terminated methylvinylsiloxane oligomer. The particle diameter of the reinforcing filler is not limited, and the median particle diameter measured by laser diffraction scattering particle size distribution is preferably in the range of 1nm to 500 μm. As the reinforcing filler, fibrous fillers such as calcium metasilicate, potassium titanate, magnesium sulfate, sepiolite, Xonolite (xolite), aluminum borate, asbestos, and glass fiber (glass fiber) may be used.

Further, a white pigment, a thermally conductive filler, an electrically conductive filler, or a phosphor may be blended for the purpose of imparting other functions to a cured product obtained by using the present composition. Further, an organic filler such as silicone elastomer fine particles may be blended for the purpose of improving the stress relaxation characteristics of the cured product.

The white pigment is a component that imparts whiteness to a cured product and improves light reflectivity, and a cured product obtained by curing the present composition by blending the component can be used as a light reflecting material for light-emitting/optical devices. Examples of the white pigment include: metal oxides such as titanium oxide, aluminum oxide, zinc oxide, zirconium oxide, and magnesium oxide; hollow fillers such as glass spheres, glass beads and the like; and barium sulfate, zinc sulfate, barium titanate, aluminum nitride, boron nitride, and antimony oxide. Titanium oxide is preferable in terms of high light reflectance and high hiding property. Further, aluminum oxide, zinc oxide, and barium titanate are preferable in terms of high light reflectance in the UV region. The white pigment has an average particle diameter and a shape not limited, but preferably an average particle diameter in the range of 0.05 to 10.0 μm or in the range of 0.1 to 5.0. mu.m. The white pigment may be surface-treated with a silane coupling agent, silica, alumina, or the like.

The thermally conductive filler or the electrically conductive filler is added for the purpose of imparting thermal conductivity/electrical conductivity (electrical conductivity) to the cured product, and specifically, examples thereof include: fine metal powder such as gold, silver, nickel, copper, aluminum, etc.; fine powder such as ceramic, glass, quartz, organic resin, etc. with metal such as gold, silver, nickel, copper, etc. deposited or plated on the surface; metal compounds such as aluminum oxide, magnesium oxide, aluminum nitride, boron nitride, and zinc oxide; graphite and mixtures of two or more thereof. When the present composition is required to have electrical insulation properties, the metal oxide-based powder or the metal nitride-based powder is preferable, and particularly, the alumina powder, the zinc oxide powder or the aluminum nitride powder is preferable, and these thermally conductive fillers or electrically conductive fillers may be used in combination of the type, particle size, particle shape and the like according to the requirements of thermal conductivity and electrical conductivity.

The phosphor is a component which is blended for converting the emission wavelength from a light source (optical semiconductor element) when the cured product is used as a wavelength conversion material. The phosphor is not particularly limited, and examples thereof include yellow, red, green, and blue light-emitting phosphors composed of an oxide-based phosphor, an oxynitride-based phosphor, a nitride-based phosphor, a sulfide-based phosphor, an oxysulfide-based phosphor, and the like, which are widely used in light-emitting diodes (LEDs).

The silicone fine particles include non-reactive silicone resin fine particles and silicone elastomer fine particles, and from the viewpoint of improving flexibility and stress relaxation characteristics of a cured product, silicone elastomer fine particles are preferably exemplified.

The silicone elastomer fine particles are a crosslinked product of a linear diorganopolysiloxane composed mainly of diorganosiloxy units (D units). The silicone elastomer fine particles can be produced by a crosslinking reaction of a diorganopolysiloxane by a hydrosilylation reaction, a condensation reaction of silanol groups, or the like, and among these, can be preferably obtained by a crosslinking reaction of an organohydrogenpolysiloxane having a silicon-bonded hydrogen atom in a side chain or a terminal and a diorganopolysiloxane having an unsaturated hydrocarbon group such as an alkenyl group in a side chain or a terminal in the presence of a hydrosilylation reaction catalyst. The silicone elastomer fine particles may take various shapes such as a spherical shape, a flat shape, and an irregular shape, and are preferably spherical in view of dispersibility, and more preferably spherical. Examples of commercially available products of such silicone elastomer fine particles include: "TREFIL E series", "EP Powder series" manufactured by Toray Dow, and "KMP series" manufactured by shin-Etsu chemical industries, Inc.

For the purpose of stably blending the above-mentioned functional filler in the present composition, a filler surface treatment may be performed by using a specific surface treatment agent in the range of 0.1 to 2.0 mass%, 0.1 to 1.0 mass%, 0.2 to 0.8 mass% with respect to the total mass of the component (D). Examples of the surface treatment agent include methylhydrogenpolysiloxane, silicone resin, metal soap, silane coupling agent, perfluoroalkyl silane, fluorine compounds such as perfluoroalkyl phosphate ester salt, and the like.

In particular, when the component (D) is a thermally conductive filler and a large amount is blended in the curable silicone composition of the present invention, particularly preferred thermally conductive fillers are a plate-like boron nitride powder having an average particle size of 0.1 to 30 μm, a granular boron nitride powder having an average particle size of 0.1 to 50 μm, a spherical and/or crushed alumina powder having an average particle size of 0.01 to 50 μm, or a spherical and/or crushed graphite having an average particle size of 0.01 to 50 μm, or a mixture of two or more of these. Most preferably, the alumina powder is a mixture of two or more of spherical and crushed alumina powders having an average particle size of 0.01 to 50 μm. In particular, by combining alumina powder having a large particle size and alumina powder having a small particle size at a ratio conforming to the closest packing theoretical distribution curve, the packing efficiency can be improved, and the viscosity and the thermal conductivity can be reduced.

In addition, the thermally conductive filler is particularly preferably treated at least partially on the surface thereof with one or more organosilicon compounds. Preferred ranges of throughput are as described above. Examples of the organosilicon compound as the surface treatment agent herein are low molecular weight organosilicon compounds such as silane, silazane, siloxane or the like; and silicone polymers or oligomers such as polysiloxanes, polycarbosiloxanes, or the like. Examples of preferred silanes are so-called silane coupling agents. Typical examples of such silane coupling agents include alkyltrialkoxysilanes (methyltrimethoxysilane, vinyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, the like), trialkoxysilanes containing an organic functional group (glycidoxypropyltrimethoxysilane, epoxycyclohexylethyltrimethoxysilane, methacryloxypropyltrimethoxysilane, aminopropyltrimethoxysilane, the like). Preferred siloxanes and polysiloxanes include: hexamethyldisiloxane, 1, 3-dihexyltetramethyldisiloxane, trialkoxysilyl-mono-terminated (single-terminated) polydimethylsiloxane, trialkoxysilyl-mono-terminated dimethylvinyl-mono-terminated polydimethylsiloxane, trialkoxysilyl-mono-terminated organofunctional-group-mono-terminated polydimethylsiloxane, trialkoxysilyl-both-terminated (double-terminated) polydimethylsiloxane, organofunctional-both-terminated polydimethylsiloxane, or the like. When siloxane is used, the number n of siloxane bonds is preferably in the range of 2 to 150. Examples of preferred silazanes are hexamethyldisilazane, 1, 3-dihexyltetramethyldisilazane or the like. Examples of preferred polycarbosiloxanes are polymers having Si-C-Si bonds in the polymer backbone.

(D) The content of the component (D) is preferably within a range of 10 to 2000 parts by mass, 10 to 1500 parts by mass, or 10 to 1000 parts by mass based on the sum (100 parts by mass) of the components (a) and (B), from the viewpoint of excellent hardness and mechanical strength of the resulting cured product.

The curable silicone composition of the present invention has an advantage that the toughness and stress relaxation properties of the resulting cured product are not impaired even when a large amount of a functional inorganic filler is blended, and therefore, a functional filler such as alumina may be blended in the composition in a range of 100 to 2000 parts by mass, 150 to 1500 parts by mass, or 300 to 1200 parts by mass with respect to the sum (100 parts by mass) of the components (a) and (B), and is preferable.

The curable silicone composition of the present invention contains the above-mentioned components (a) to (D), and from the viewpoint of further improving the melting characteristics thereof, (E) hot-melt particles having a dropping point of 50 ℃ or higher and a melt viscosity of 10Pas or lower as measured by a rotational viscometer at 150 ℃ may be added, and these are preferable.

The kind of the component (E) is not particularly limited as long as the above dropping point condition and the condition of kinematic viscosity at 150 ℃ at the time of melting are satisfied, and one or more selected from various hot-melt synthetic resins, waxes, fatty acid metal salts and the like can be used. The component (E) exhibits a low kinematic viscosity at a high temperature (150 ℃) and forms a melt having excellent fluidity. Further, by using the components (a) to (C) in combination, the component (E) in the melt formed from the present composition rapidly diffuses into the entire composition at a high temperature, thereby exhibiting the following effects: the viscosity of the substrate surface to which the molten composition is applied and the entire composition is reduced, and the surface friction between the substrate and the molten composition is drastically reduced, so that the fluidity of the entire composition is greatly increased. Therefore, the viscosity and fluidity of the molten composition can be greatly improved by adding only a very small amount relative to the total amount of other components.

(E) As the component (c), a petroleum wax such as paraffin may be used as long as the above-mentioned dropping point and kinematic viscosity at the time of melting are satisfied, but from the viewpoint of the technical effect of the present invention, a hot-melt component composed of a fatty acid metal salt and a fatty acid ester of an erythritol derivative is preferable, and a metal salt of a higher fatty acid such as stearic acid, palmitic acid, oleic acid, isononanoic acid is particularly preferable; pentaerythritol tetrastearate, dipentaerythritol adipic acid stearate, glycerol tri-18-hydroxystearate, pentaerythritol stearic acid full ester. Here, the kind of the fatty acid metal salt is also not particularly limited, and preferable examples thereof include: alkali metal salts such as lithium, sodium, and potassium; alkaline earth metal salts such as magnesium, calcium and barium; or a zinc salt.

Particularly preferred as component (E) are a fatty acid metal salt having a fatty acid leaving amount of 5.0% or less, (E0) a fatty acid metal salt having a fatty acid leaving amount of 4.0% or less, and 0.05 to 3.5% and an erythritol derivative. As such a component, for example, at least one or more metal salts of stearic acid are exemplified. Specifically, it is most preferable to use a hot-melt component having a melting point of 150 ℃ or less, selected from calcium stearate (melting point 150 ℃), zinc stearate (melting point 120 ℃), magnesium stearate (melting point 130 ℃), pentaerythritol tetrastearate (melting point 60-70 ℃), pentaerythritol adipic stearate (melting point 55-61 ℃), pentaerythritol tetrastearate (melting point 62-67 ℃), and the like.

The amount of the component (E) used may be 0.01 to 3.5 parts by mass or 0.01 to 3.0 parts by mass, based on 100 parts by mass of the entire composition, as the content of the component (E0). If the amount of the component (E) exceeds the above upper limit, the cured product obtained from the curable silicone composition of the present invention may have insufficient adhesiveness and mechanical strength. When the amount of the component (E) used is less than the lower limit, sufficient fluidity during heating and melting may not be achieved.

The present composition may contain a curing retarder and a tackifier as other optional components as long as the object of the present invention is not impaired.

As the curing retarder, there can be exemplified: alkynols such as 2-methyl-3-butyn-2-ol, 3, 5-dimethyl-1-hexyn-3-ol, 2-phenyl-3-butyn-2-ol, and 1-ethynyl-1-cyclohexanol; enyne compounds such as 3-methyl-3-pentene-1-yne and 3, 5-dimethyl-3-hexene-1-yne; alkenyl-containing low molecular weight siloxanes such as tetramethyltetravinylcyclotetrasiloxane and tetramethyltetrahexenylcyclotetrasiloxane; alkynyloxysilanes such as methyl-tris (1, 1-dimethylpropynyloxy) silane and vinyl-tris (1, 1-dimethylpropynyloxy) silane. The content of the curing retarder is not limited, and is preferably within a range of 10 to 10000ppm by mass relative to the present composition.

As the adhesion promoter, an organosilicon compound having at least one alkoxy group bonded to a silicon atom in one molecule is preferable. Examples of the alkoxy group include: methoxy, ethoxy, propoxy, butoxy, methoxyethoxy, and particularly preferably methoxy. Examples of the silicon atom-bonded group other than the alkoxy group in the organosilicon compound include: halogen-substituted or unsubstituted monovalent hydrocarbon groups such as alkyl, alkenyl, aryl, aralkyl, and haloalkyl groups; 3-glycidoxypropyl, 4-glycidoxypropylGlycidoxyalkyl such as cyclobutyl; epoxycyclohexylalkyl groups such as 2- (3, 4-epoxycyclohexyl) ethyl group and 3- (3, 4-epoxycyclohexyl) propyl group; an alkylene oxide group such as a 3, 4-epoxybutyl group, a 7, 8-epoxyoctyl group, etc.; a monovalent organic group containing an acryloyl group such as 3-methacryloxypropyl group; a hydrogen atom. The organosilicon compound preferably has a group capable of reacting with an alkenyl group or a silicon atom-bonded hydrogen atom in the present composition, and specifically preferably has a silicon atom-bonded hydrogen atom or alkenyl group. In addition, the organosilicon compound preferably has at least one epoxy group-containing monovalent organic group in one molecule, from the viewpoint of imparting good adhesion to various substrates. Examples of such an organosilicon compound include: organosilane compounds, organosiloxane oligomers, alkyl silicates. Examples of the molecular structure of the organosiloxane oligomer or the alkyl silicate include: the polymer is linear, branched, cyclic or network-like, and a portion of the polymer having a branch is preferably linear, branched or network-like. As the organic silicon compound, there can be exemplified: silane compounds such as 3-glycidoxypropyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; a siloxane compound having in each molecule at least one silicon atom-bonded alkenyl group or silicon atom-bonded hydrogen atom and a silicon atom-bonded alkoxy group, a silane compound having at least one silicon atom-bonded alkoxy group or a mixture of a siloxane compound and a siloxane compound having in each molecule at least one silicon atom-bonded hydroxyl group and a silicon atom-bonded alkenyl group, a reaction mixture of an amino group-containing organoalkoxysilane and an epoxy group-containing organoalkoxysilane, an organic compound having in one molecule at least two alkoxysilane groups and having a bond other than a silicon-oxygen bond between these silane groups, and a compound of the general formula R^a _nSi(OR^b)_4-nThe epoxy group-containing silane or a partial hydrolysis condensate thereof,

R^a _nSi(OR^b)_4-n

(in the formula, R^aIs a monovalent epoxy-containing organic radical, R^bIs carbonAn alkyl group having 1 to 6 atoms or a hydrogen atom. n is a number in the range of 1 to 3)

A reaction mixture of a vinyl group-containing siloxane oligomer (including a siloxane oligomer of a chain or ring structure) and an epoxy group-containing trialkoxysilane, methyl polysilicate, ethyl polysilicate, and ethyl polysilicate containing epoxy groups. The thickener is preferably a low-viscosity liquid, and the viscosity thereof is preferably in the range of 1 to 500 mPas at 25 ℃. The content of the thickener is not limited, but is preferably in the range of 0.01 to 10 parts by mass based on 100 parts by mass of the total of the present composition.

In the present invention, as a particularly preferable adhesion promoter, a reaction mixture of an amino group-containing organoalkoxysilane and an epoxy group-containing organoalkoxysilane is exemplified. Such a component is a component that improves initial adhesion to various substrates that come into contact during curing, particularly low-temperature adhesion to an unwashed adherend. In addition, a curing system of a curable silicone composition containing the present adhesion promoter may also function as a crosslinking agent. Such a reaction mixture is disclosed in Japanese patent application laid-open No. 52-8854 and Japanese patent application laid-open No. 10-195085.

Examples of the alkoxysilane having an amino group-containing organic group constituting such a component include: aminomethyl triethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 3-aminopropyl methyldimethoxysilane, N- (2-aminoethyl) aminomethyl tributoxysilane, N- (2-aminoethyl) -3-aminopropyl trimethoxysilane, N- (2-aminoethyl) -3-aminopropyl methyldimethoxysilane, 3-anilinopropyl triethoxysilane.

Further, as the epoxy group-containing organoalkoxysilane, there can be exemplified: 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethylmethyldimethoxysilane.

The molar ratio of the alkoxysilane having an amino group-containing organic group to the alkoxysilane having an epoxy group-containing organic group is preferably in the range of (1: 1.5) to (1: 5), and particularly preferably in the range of (1: 2) to (1: 4). The component (e1) can be easily synthesized by mixing an alkoxysilane having an amino group-containing organic group and an alkoxysilane having an epoxy group-containing organic group as described above and reacting them at room temperature or under heating.

In particular, the present invention particularly preferably contains a cyclosilazane (carbosilatrane) derivative represented by the following general formula, which is obtained by cyclizing an alkoxysilane having an amino group-containing organic group and an alkoxysilane having an epoxy group-containing organic group by an alcohol exchange reaction when the alkoxysilanes are reacted by the method described in Japanese patent application laid-open No. 10-195085.

{ formula (II) wherein R¹Is alkyl, alkenyl or alkoxy, R²Are identical or different radicals selected from the group consisting of the radicals represented by the general formula³Are identical or different hydrogen atoms or alkyl groups.

(in the formula, R⁴Is alkylene or alkyleneoxyalkylene, R⁵Is a monovalent hydrocarbon radical, R⁶Is alkyl, R⁷Is alkylene, R⁸Is alkyl, alkenyl or acyl, and a is 0, 1 or 2. )}

Examples of such cyclonitrogenosilane derivatives include cyclonitrogenosilane derivatives having a silicon atom-bonded alkoxy group or a silicon atom-bonded alkenyl group in one molecule shown in the following structures.

(wherein Rc is a group selected from the group consisting of methoxy, ethoxy, vinyl, allyl, and hexenyl)

In the present invention, a silatrane derivative represented by the following structural formula may be used as the thickener.

In the formula¹Are identical or different hydrogen atoms or alkyl radicals, in particular, as R¹Preferably a hydrogen atom or a methyl group. Further, R in the above formula²Is selected from the group consisting of hydrogen atoms, alkyl groups and general formula: -R⁴-Si(OR⁵)_xR⁶ _(3-x)The same or different groups in the group consisting of the alkoxysilyl-containing organic groups shown, wherein R²At least one of (a) and (b) is the alkoxysilyl-containing organic group. As R²Examples of the alkyl group of (b) include a methyl group and the like. In addition, in R²In the alkoxysilyl group-containing organic group of (A), R in the formula⁴As the divalent organic group, there may be mentioned an alkylene group or an alkyleneoxyalkylene group, and particularly preferred are an ethylene group, a propylene group, a butylene group, a methyleneoxypropylene group and a methyleneoxypentylene group. In addition, R in the formula⁵The alkyl group has 1 to 10 carbon atoms, and is preferably a methyl group or an ethyl group. In addition, R in the formula⁶Is a substituted or unsubstituted monovalent hydrocarbon group, preferably a methyl group. In the formula, x is 1, 2 or 3, preferably 3.

As such R²Examples of the alkoxysilyl group-containing organic group in (2) include the following groups.

-(CH2)2Si(OCH3)3-(CH2)2Si(OCH3)2CH3

-(CH2)3Si(OC2H5)3-(CH2)3Si(OC2H5)(CH3)2

-CH2O(CH2)3Si(OCH3)3

-CH2O(CH2)3Si(OC2H5)3

-CH2O(CH2)3Si(OCH3)2CH3

-CH2O(CH2)3Si(OC2H5)2CH3

-CH2OCH2Si(OCH3)3-CH2OCH2Si(OCH3)(CH3)2

R in the above formula³R is at least one group selected from the group consisting of substituted or unsubstituted monovalent hydrocarbon groups, C1-10 alkoxy groups, glycidoxyalkyl groups, oxiranylalkyl groups and acyloxyalkyl groups³Examples of the monovalent hydrocarbon group of (2) include alkyl groups such as methyl group, and R is³Examples of the alkoxy group of (2) include methoxy, ethoxy and propoxy as R³The glycidoxyalkyl group of (A) may be exemplified by 3-glycidoxypropyl group as R³Examples of the oxiranylalkyl group(s) include 4-oxiranylbutyl and 8-oxiranyloctyl, as R³Examples of the acyloxyalkyl group in (b) include acetoxypropyl and 3-methacryloxypropyl. In particular, as R³Alkyl, alkenyl and alkoxy groups are preferred, alkyl or alkenyl groups are more preferred, and groups selected from methyl, vinyl, allyl and hexenyl groups are particularly preferred.

The present composition may contain, as other optional components, heat-resistant agents such as iron oxide (red iron oxide), cerium oxide, cerium dimethylsilanol, cerium salt of fatty acid, cerium hydroxide, and zirconium compound; dyes, pigments other than white, flame retardancy-imparting agents, and the like.

The composition can be used in the form of granules, sheets, etc. The granular form refers to a form obtained by tableting the composition of the present invention, and is excellent in workability and curability. The "granule" is sometimes referred to as a "tablet". The shape of the particles is not limited, and is usually spherical, oval spherical or cylindrical. The particle size is not limited, and for example, the particle size has an average particle diameter or equivalent circle diameter of 500 μm or more. In the case of producing such a granular composition, tableting the present composition in the form of granules is an efficient production method. When the composition of the present invention is to be granulated, it can be produced by stirring the components (a) to (C) and optionally the component (D) with a powder kneader described later.

The present composition may be used by molding into a sheet form. For example, a sheet made of a curable silicone composition having an average thickness of 10 to 1000 μm is hot-melt and heat-curable at high temperatures, and therefore, is advantageous in that it is excellent in handling workability and melting characteristics particularly when used for compression molding or the like.

Such a sheet-like composition can also be produced by integrating all the components by a single-screw or twin-screw continuous kneader and then forming the mixture into a predetermined thickness by two rolls or the like. Further, after the above-mentioned granular curable silicone composition is obtained, they may be integrated by a kneader to adjust the thickness.

[ use as a laminate and film adhesive ]

The composition can be used in the form of a sheet, and in particular, can be used as a laminate comprising: the film-like substrate having a release layer has a structure including a sheet-like member formed of the curable silicone composition described above between two film-like substrates.

The method for producing such a releasable laminate is not particularly limited, and can be achieved by a method for producing a curable silicone sheet comprising the following steps:

step 1: a step of mixing the components of the curable silicone composition;

and a step 2: a step of kneading the mixture obtained in step 1 while heating and melting the mixture;

step 3: laminating the mixture obtained in step 2 after the heating and melting between films having at least one release surface;

and step 4: a step of stretching the laminate obtained in step 3 between rolls to form a curable silicone sheet having a specific film thickness,

optionally, a roller having a cooling or temperature adjusting function may be used in step 4 or the like, and after step 4, a step of cutting the obtained laminate including the curable silicone sheet may be provided.

The type of the film-like substrate is not particularly limited, and a polyester film, a polyolefin film, a polycarbonate film, an acrylic film, or the like can be suitably used. The sheet-like substrate is preferably non-porous.

The release layer is a structure necessary for easily releasing a sheet-like member made of a curable silicone composition from a film-like base material, and may be referred to as a release liner, a separator, a release layer, or a release coating layer. The release layer is preferably a release layer having release coating ability such as a silicone release agent, a fluorine release agent, an alkyd release agent, or a fluorine silicone release agent, and may be a substrate itself in which fine irregularities are physically formed on the surface of the substrate or the release layer is not easily adhered to an adhesive material layer formed of the curable reactive silicone adhesive composition of the present invention or a cured product thereof. In particular, in the laminate of the present invention, a release layer obtained by curing a fluorosilicone-based release agent is preferably used as the release layer.

The laminate can be used, for example, by applying a sheet-like member made of a curable silicone composition to an adherend and then peeling the uncured sheet-like member from the film-like substrate.

The present compositions operate in granular, particulate or tablet form at room temperature and are therefore non-flowing solids at 25 ℃. Here, the term "non-flowable" means that it does not deform or flow in a non-loaded state, and preferably does not deform or flow in a non-loaded state at 25 ℃ when it is molded into granules, tablets, or the like. Such non-fluidity can be evaluated, for example, as follows: the present composition after molding was placed on a hot plate at 25 ℃ and did not substantially deform or flow without a load or even with a constant load. This is because, when the resin composition is non-flowable at 25 ℃, the shape retention at that temperature is good and the surface adhesiveness is low.

The softening point of the present composition is preferably 100 ℃ or lower. Such a softening point is a temperature at which the amount of deformation in the height direction is 1mm or more when the amount of deformation of the composition is measured after the heating plate is pressed from above for 10 seconds with a load of 100g weight and the load is removed.

The present composition tends to have a sharp decrease in viscosity at high temperature and high pressure (i.e., in the molding step), and it is preferable to use a value measured at the same high temperature and high pressure as a value of a useful melt viscosity. Therefore, the melt viscosity of the present composition is preferably measured at a high pressure using a flow tester (manufactured by shimadzu corporation) as compared with the measurement using a rotational viscometer such as a rheometer. Specifically, the melt viscosity of the present composition at 150 ℃ is preferably 200 pas or less, more preferably 150 or less. This is because the composition has good adhesion to a substrate after being hot-melted and then cooled at 25 ℃.

[ method for producing curable Silicone composition ]

The present composition can be produced by powder-mixing components (a) to (C), and further optional other components (including component (D) and component (E)) at a temperature of less than 50 ℃. The powder mixer used in the present manufacturing method is not limited, and examples thereof include: single-or twin-shaft continuous mixers, twin-roll mixers, ross mixers, hobart mixers, dental material mixers (dental mixers), planetary mixers, kneaders, Labo mills, mini-mills, henschel mixers, preferably Labo mills, mini-mills, henschel mixers. [ method for producing curable Silicone sheet ]

The curable silicone sheet is characterized by having a hot-melt property and being formed from a curable silicone composition containing a polyorganosiloxane resin, a curing agent and a functional filler, and the production method of the present invention includes the following steps 1 to 4.

Step 1: a step of mixing the constituent components of the curable silicone composition at a temperature of 50 ℃ or higher;

and a step 2: a step of kneading the mixture obtained in step 1 while heating and melting the mixture;

step 3: laminating the mixture obtained in step 2 after the heating and melting between films having at least one release surface;

and step 4: a step of stretching the laminate obtained in step 3 between rolls to form a curable silicone sheet having a specific film thickness,

here, "having a hot-melt property" means that the softening point is in the range of 50 to 200 ℃, and the hot-melt property is such that the hot-melt property softens or flows when heated. In addition, the curable silicone sheet of the present invention may be a curable silicone sheet that contains a polyorganosiloxane resin as a constituent component, regardless of the hot-melt property of the polyorganosiloxane resin, as long as a mixture containing the polyorganosiloxane resin, a curing agent, and a functional filler has a hot-melt property.

[ Process 1]

The step 1 is a mixing step of the curable particulate silicone composition containing the polyorganosiloxane resin (preferably in the form of fine particles), the curing agent, and the functional filler, which are the constituent components of the curable silicone composition. The respective components are as described above.

The mixture provided in step 1 is a curable particulate silicone composition, and the mixture as a whole has a hot-melt property. In another aspect, the mixture is non-flowable at 25 ℃. Here, the term "non-flowable" means that it does not deform or flow in a non-loaded state, and preferably does not deform or flow in a non-loaded state at 25 ℃ when it is molded into granules, tablets, or the like. Such non-fluidity can be evaluated, for example, as follows: the present composition after molding was placed on a hot plate at 25 ℃ and did not substantially deform or flow without a load or even with a constant load. This is because, when the resin composition is non-flowable at 25 ℃, the shape retention at that temperature is good and the surface adhesiveness is low.

The softening point of the mixture provided in step 1 is 200 ℃ or lower, preferably 150 ℃ or lower. Such a softening point is a temperature at which the amount of deformation in the height direction is 1mm or more when the amount of deformation of the composition is measured after the heating plate is pressed from above for 10 seconds with a load of 100g weight and the load is removed.

The softening point of the mixture supplied in step 1 is 200 ℃ or lower, and in step 2 described later, the whole mixture is heated to a temperature equal to or higher than the softening point of the mixture, and the mixture is heated and melted to impart a certain fluidity. The softened product or melt is molded to obtain a hot-melt curable silicone sheet made of the curable particulate silicone composition.

The step of mixing the polyorganosiloxane resin, the curing agent, the functional filler, and other optional components is not particularly limited, but the mixture as a whole is preferably produced by powder mixing at a temperature lower than the softening point of the polyorganosiloxane resin fine particles. The powder mixer used in the present manufacturing method is not limited, and examples thereof include: single-or twin-shaft continuous mixers, twin-roll mixers, ross mixers, hobart mixers, dental material mixers (dental mixers), planetary mixers, kneaders, Labo mills, mini-mills, henschel mixers, preferably Labo mills, mini-mills, henschel mixers.

[ Process 2]

The step 2 is a step of kneading the mixture obtained in the step 1 while heating and melting the mixture, and the mixture having a heat-melting property is heated and kneaded at a temperature not lower than the softening point thereof, preferably in a temperature range of 50 to 200 ℃, whereby the entire composition is melted or softened, and the polyorganosiloxane resin fine particles, the curing agent, and the functional filler can be uniformly dispersed as a whole. There are practical benefits as follows: when the mixture is press-molded into a sheet form in step 4 after step 3, the mixture can be formed into a uniform thin-layer-shaped molded sheet by pressing once, and molding failure and cracks in the sheet font can be avoided. On the other hand, if the temperature is lower than the lower limit, softening is insufficient, and it may be difficult to obtain a molten or softened mixture in which the respective components are uniformly dispersed as a whole even by using a mechanical force, and such a mixture may not form a uniform thin-layer-shaped molded sheet even if the mixture is press-molded into a sheet shape in step 3 or step 4, and may cause breakage or cracking of the sheet. Conversely, if the temperature exceeds the upper limit, the curing agent may react during mixing, and the whole may be significantly thickened or cured to lose hot-melt property, thereby forming a cured product, which is not preferable. Therefore, when a hydrosilylation catalyst is used as the component (C), it is preferable to use a particulate platinum-containing hydrosilylation catalyst dispersed or encapsulated in a thermoplastic resin.

When the mixture obtained in step 1 has a low melt viscosity under heating and is rich in fluidity, it may be preliminarily temporarily molded and then laminated on a release film in step 3 described later, and specifically, when the melt viscosity of the mixture obtained in step 2 after heating and melting as measured by an Koshig flow tester at 150 ℃ is in the range of 1 to 1000Pas, it is preferable that temporary molding is performed in step 3.

On the other hand, when the mixture obtained in step 1 has a high melt viscosity under heating and insufficient fluidity, the mixture obtained in step 1 may be melt-kneaded at a temperature equal to or higher than its softening point in step 2 to obtain a uniform composition, and then laminated on a release film in step 3 without being temporarily molded.

The mixing device in step 2 is not limited as long as it is a batch (batch) type such as a kneader having a heating/cooling function, a banbury mixer, a henschel mixer, a planetary mixer, a twin-roll kneader, a three-roll kneader, a ross mixer, or LABO plastics; the continuous heating and kneading apparatus such as a single-screw extruder or a twin-screw extruder having heating/cooling functions may be used, and is not particularly limited, and may be selected according to the efficiency of the treatment time and the ability to control the shear heat generation. In view of the processing time, the kneading apparatus may be a continuous heating kneader such as a single-screw extruder or a twin-screw extruder, or a batch mixer such as LABO plastimill. Among them, from the viewpoint of production efficiency of the curable silicone sheet, a continuous heating and kneading apparatus such as a single-screw extruder or a twin-screw extruder is preferably used.

[ Process 3]

Step 3 is a step of laminating the mixture obtained in step 2 after heating and melting between films having at least one release surface, and is a preliminary step for performing pressure molding in step 4. By forming a laminate in which the mixture obtained in step 2 is sandwiched between films and performing pressure molding from the films by roll stretching, a sheet-like molded article can be obtained, and after molding, only the films can be removed from the sheet-like molded article by a release surface.

The mixture obtained in step 2 after heating and melting is laminated between two films. Depending on the use form of the obtained curable silicone sheet, it is preferable that both films have release surfaces, and it is particularly preferable that in step 3, the mixture obtained in step 2 is laminated between the release surfaces of the respective films. By adopting such a laminated form, a laminated sheet which can be peeled from both sides with the curable silicone sheet in a thin layer sandwiched between the peelable films can be obtained by press molding in step 4 and thereafter arbitrarily cutting, and at the time of use, the formed curable silicone sheet is not damaged, and only the curable silicone sheet can be exposed by peeling off the films on both sides.

The base material of the film used in step 3 is not particularly limited, and examples thereof include a paperboard, a corrugated board, a clay-coated paper, and a polyolefin-laminated paper, and specifically include: polyethylene laminated paper, synthetic resin film/sheet, natural fiber cloth, synthetic fiber cloth, artificial leather cloth, and metal foil. Particularly preferred are synthetic resin films/sheets, and examples of the synthetic resin include: polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyethylene terephthalate, nylon. Particularly when heat resistance is required, films of heat-resistant synthetic resins such as polyimide, polyether ether ketone, polyethylene naphthalate (PEN), liquid crystal polyarylate, polyamide imide, and polyether sulfone are preferable. On the other hand, in applications requiring visual confirmation such as display devices, transparent substrates are preferred, and specifically, transparent materials such as polypropylene, polystyrene, polyvinylidene chloride, polycarbonate, polyethylene terephthalate, and PEN are preferred.

The thickness of the film is not particularly limited, but is usually about 5 to 300. mu.m.

Preferably, the film has at least one release layer, which is in contact with the mixture obtained in step 2. Thus, the hot-melt curable silicone sheet after pressure molding can be easily peeled from the film through steps 3 and 4. The release layer is also referred to as a release liner, a separator, a release layer, or a release coating layer, and is preferably a release layer having release coating ability such as a silicone-based release agent, a fluorine-based release agent, an alkyd-based release agent, or a fluorine-silicone-based release agent, and may be a substrate itself in which fine irregularities are physically formed on the surface of the substrate, or the substrate itself is not easily adhered to the hot-melt curable silicone sheet of the present invention.

In step 3, the mixture obtained in step 2 is laminated between two films. The step is not particularly limited, and the mixture obtained in step 2 may be discharged or applied to the release layer of one film, and the release layer of the other film may be bonded to the mixture to form a laminate. In this case, in the continuous process for producing the curable silicone sheet, each film is conveyed to the supply position of the mixture in step 2 via a rotary roller, and only the lamination operation between the films is performed.

The amount of the mixture supplied between the films to be obtained in step 2 in step 3 can be designed according to the production rate and scale. For example, the mixture obtained in step 2 may be supplied between the films at a supply rate of 1 to 10 kg/hour, but it is needless to say that the mixture is not limited thereto. However, in step 3, the amount of the mixture obtained in step 2 to be laminated between the films needs to be determined according to the average thickness of the curable silicone sheet designed in step 4, and needs to be a thickness at which the rolling process can be performed in step 4.

When the mixture obtained in step 1 has a low melt viscosity and is rich in fluidity, it is preferable that the mixture obtained in step 2 after being heated and melted is discharged into a film shape by using a die and laminated between films in step 3. Here, the die is used to temporarily mold the mixture, the kind and the thickness of the temporary mold are not particularly limited, and a T-shaped die may be used to temporarily mold the mixture into a substantially sheet shape having a thickness in the range of 100 to 2000 μm (═ 2mm), and is preferable.

When the mixture obtained in step 1 has a low melt viscosity and is rich in fluidity during heating, it is preferable to include a step of cooling or adjusting the temperature of the entire laminate obtained in step 3, after the above-described temporary molding, in step 4 or a step preceding step 4. This is because the hot melt is cooled to be solid, and the press molding in step 4 is effectively performed. The cooling step is not particularly limited, but may be performed by cooling the mixture supplied or laminated on the film by a cooling roll or the like using a cooling means such as air cooling or a cooling solvent in a range of-50 ℃ to room temperature. The details of the temperature adjustment will be described in step 4.

On the other hand, when the mixture obtained in step 1 has a high melt viscosity under heating and insufficient fluidity, the semisolid mixture may be supplied onto a film without temporary molding in step 3 and laminated.

[ Process 4]

Step 4 is a step of stretching the laminate obtained in step 3 between rolls to form a curable silicone sheet having a specific film thickness, and is a step of subjecting the mixture obtained in step 2 to pressure stretching from the film to form a uniform curable silicone sheet.

The rolling process in step 4 may be performed on the laminate obtained in step 3 by a known rolling method such as roll rolling. In particular, in the case of roll rolling, there is an advantage that a curable silicone sheet having a desired thickness can be designed by adjusting the gap between rolls, and for example, by adjusting the gap between rolls to be constant within a range of 10 to 2000 μm in average thickness and rolling, a curable silicone sheet having excellent flatness and having extremely few defects on the sheet surface and in the sheet interior can be obtained. More specifically, in the case of roll rolling, it is particularly preferable to adjust the gap between the rolls within a range of 1.5 to 4.0 times the average thickness of the intended cured polyorganosiloxane film.

By stretching in step 4, a substantially flat curable silicone sheet having a thickness of 10 to 2000 μm can be obtained. The mixture heated and melted in step 2 is subjected to roll stretching in step 3 to be laminated between release films, whereby a release laminate comprising a hot-melt curable silicone sheet having low defects and excellent workability in handling by release can be obtained.

[ temperature control in Process 4]

In step 4, when the laminate obtained in step 3 is stretched between rolls, the rolls preferably further have a temperature adjusting function, and the temperature of the entire laminate is adjusted during roll rolling, and heating or cooling is performed as necessary. By this temperature regulation, the following practical benefits are achieved: the gap between the rolls can be stably maintained, and the flatness and uniformity (uniformity of film thickness) of the obtained hot-melt curable silicone sheet can be improved. The specific temperature control range may be appropriately designed according to the heat resistance of the film, the thickness (design thickness) of the curable silicone sheet, the reactivity thereof, and the like, but is approximately in the range of 5 to 150 ℃.

[ cutting Process ]

In step 4, a releasable laminate in which a hot-melt curable silicone sheet is sandwiched between releasable films can be obtained, but the step of cutting the laminate including the curable silicone sheet may be arbitrarily included. The curable silicone sheet may further include a step of winding the sheet by a winding device. This makes it possible to obtain a releasable laminate comprising a hot-melt curable silicone sheet of a desired size.

[ laminate ]

The laminate obtained by the above steps has a structure in which: a curable silicone sheet having a substantially flat thickness of 10 to 2000 [ mu ] m, which is substantially flat and contains polyorganosiloxane resin fine particles, a curing agent and a functional filler, is laminated between films having at least one release surface. The films may each have a release surface, and are preferably provided.

[ curable Silicone sheet ]

The curable silicone sheet obtained by the production method of the present invention is a curable silicone granular composition containing a polyorganosiloxane resin, a curing agent, and a functional filler, has hot-melt properties, and can be used as an adhesive material having heat-fusible properties. In particular, the curable silicone sheet is excellent in moldability, gap filling properties, and adhesive force, and can be used as a die attach film or a film adhesive. Further, it can be preferably used as a curable silicone sheet for compression molding or press molding.

Specifically, the curable silicone sheet obtained by the production method of the present invention is peeled off from a releasable film, placed in a desired site such as a semiconductor, and then bonded to adherends by forming a film adhesive layer exhibiting gap-filling properties with respect to irregularities and gaps, to temporarily fix, place, and adhere the adherends to each other, and the curable silicone sheet is heated to 150 ℃. The releasable film may be released after the curable silicone sheet is heated to form a cured product, and the timing of the release may be selected according to the use and method of use of the curable silicone sheet.

Since the curable silicone sheet is hot-melt, even if there are irregularities on the surface to be bonded of an adherend, for example, the irregularities or gaps can be filled without any gap to form an adhesive surface by heating the sheet before final curing to soften or fluidize the sheet. As a heating method of the curable silicone sheet, for example, various constant temperature chambers, heating plates, electromagnetic heating devices, heating rollers, and the like can be used. For more efficient bonding and heating, for example, an electrothermal press, a membrane type laminator, a roll laminator, or the like is preferably used.

[ method of Forming a cured product ]

The present composition can be cured by a method including at least the following steps (I) to (III).

A step (I) in which the composition is heated to 100 ℃ or higher to melt the composition;

a step (II) of injecting the curable silicone composition obtained in the step (I) into a mold or distributing the curable silicone composition obtained in the step (I) over the mold by closing the mold; and

and (III) curing the curable silicone composition injected in the step (II).

In the above-mentioned step, a transfer molding machine, a compression molding machine, an injection molding machine, an auxiliary piston (ram) type molding machine, a slide type molding machine, a double piston type molding machine, a low pressure sealing molding machine, or the like can be used. In particular, the composition of the present invention can be preferably used for the purpose of obtaining a cured product by transfer molding and compression molding.

Finally, in the step (III), the curable silicone composition injected (applied) in the step (II) is cured. When (C1) an organic peroxide is used as component (C), the heating temperature is preferably 150 ℃ or higher or 170 ℃ or higher, and when (C2) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in the molecule and a hydrosilylation reaction catalyst are used, the heating temperature is preferably 100 ℃ or higher or 130 ℃ or higher.

On the other hand, the curable silicone composition of the present invention can be formed into a film-like sheet having a thickness in the range of 100 to 1000 μm by being sandwiched between sheet-like substrates provided with a release layer and molded into a predetermined thickness by two rolls or the like as described above. The film-like sheet formed from the curable silicone composition can be used as a curable silicone adhesive for producing a die attach film such as a semiconductor chip or a film.

[ use of the composition ]

The composition is hot-melt, has excellent workability and curability in melting (hot-melt), and gives a cured product having excellent resistance to coloration at high temperatures, and is therefore useful for a semiconductor member such as a light-reflecting material for light-emitting/optical devices, and an optical semiconductor having the cured product. Furthermore, the cured product is excellent in mechanical properties and therefore is preferable as a sealing agent for a semiconductor; a sealing agent for power semiconductors such as SiC and GaN; an adhesive, a potting agent, a protective agent, and a coating agent for electric and electronic devices. Further, the present composition is also preferable as a material for transfer molding, compression molding or injection molding because it has a hot-melt property. In particular, it is preferably used as a semiconductor sealing agent using a secondary molding method in molding. Furthermore, a sheet obtained by forming the composition into a sheet can be used as a curable film adhesive or a stress buffer layer between two types of substrates having different linear expansion coefficients.

Further, the curable silicone composition of the present invention, particularly, a curable silicone composition in the form of particles or sheets, can be used for large-area packaging of semiconductor substrates (including wafers). Furthermore, a sheet obtained by molding the curable silicone composition of the present invention into a sheet can be used for a die attach film, a package of a flexible device, a stress relaxation layer for bonding two different substrates, and the like.

[ uses of cured products ]

The use of the cured product of the present invention is not particularly limited, but the composition of the present invention is hot-melt, and has excellent moldability and mechanical properties, and the cured product shows the behavior of the average linear expansion coefficient and storage modulus which are characteristic at room temperature to high temperature. Therefore, a cured product obtained by curing the present composition can be preferably used as a member for a semiconductor device, and can be preferably used as a sealing material for a semiconductor element, an IC chip, or the like, or an adhesive/bonding member for a semiconductor device.

The semiconductor device provided with a member composed of the cured product of the present invention is not particularly limited, and is particularly preferably a light-emitting semiconductor device as a light-emitting/optical device. The cured product of the present invention is excellent in resistance to coloration at high temperatures, and therefore can be more preferably used as a light-reflecting material for use in an optical semiconductor device in which whiteness becomes important.

Examples

The hot-melt curable silicone composition of the present invention and the method for producing the same will be described in detail with reference to examples and comparative examples. In the formula, Me and Vi each represent a methyl group and a vinyl group. The softening points of the curable silicone compositions of the examples and comparative examples were measured by the following methods. The curable silicone composition was heated at 150 ℃ for 2 hours to prepare a cured product, and the elastic modulus and tensile elongation were measured by the following methods. The results are shown in Table 1.

[ melt viscosity ]

The melt viscosity at 150 ℃ of the curable silicone composition was measured by an Koshikawa Kagaku Kogyo CFT-500EX (manufactured by Shimadzu corporation) using a nozzle having a diameter of 0.5mm under a pressure of 100 kgf.

[ storage modulus ]

The curable silicone composition was heated at 150 ℃ for 2 hours to produce a cured product. The storage modulus of the cured product at-50 ℃ to 250 ℃ was measured using a rheometer ARES (manufactured by T A Instruments Japan K.K.) and read at 25 ℃. The measurement values at 25 ℃ are shown in Table 1.

[ tensile elongation ]

The curable silicone composition was heated at 150 ℃ for 2 hours to produce a cured product. The tensile elongation of the cured product was measured by the method specified in JIS K6251-2010 "vulcanized rubber and thermoplastic rubber-method for determining tensile characteristics".

[ thermal conductivity ]

The curable silicone composition was heated at 150 ℃ for 2 hours to produce a cured product having dimensions of 1.5cm × 1.5cm × 1.0cm (thickness). The thermal conductivity of the cured product was measured by a hot plate method using TPS500S (manufactured by hotsisc corporation). The results are shown in table 1.

Hereinafter, polyorganosiloxane resins containing a hydrosilylation catalyst were prepared by the methods described in reference examples 1 to 7, and the presence or absence of softening point/melt viscosity was evaluated for their non-heat-fusible properties. The polyorganosiloxane resin fine particles were prepared by the methods described in reference examples 8 to 13. In the reference example, 1,3, 3-tetramethyl-1, 3-divinyldisiloxane used as a platinum complex as a hydrosilylation catalyst is described as "1, 3-divinyltetramethyldisiloxane".

(measurement of molecular weight of polyorganosiloxane resin)

The weight average molecular weight (Mw) of the polyorganosiloxane resin in each reference example was determined by standard polystyrene conversion using Gel Permeation Chromatography (GPC) manufactured by Waters corporation with toluene as a solvent.

[ reference example 1]

A1L flask was charged with an average unit formula which was a white solid at 25 deg.C

(Me₃SiO_1/2)_0.44(SiO_4/2)_0.56(HO_1/2)_0.02

270.5g of a 55 mass% -xylene solution of the indicated polyorganosiloxane resin and 0.375g of a1, 3-divinyltetramethyldisiloxane solution of a1, 3-divinyltetramethyldisiloxane complex of platinum (the content of platinum metal is about 4000ppm) were uniformly stirred at room temperature (25 ℃ C.) to prepare a xylene solution containing 10ppm of the polyorganosiloxane resin (1) in terms of platinum metal by mass. Further, the polyorganosiloxane resin (1) does not soften/melt even when heated to 200 ℃, and is not hot-melt. Further, the weight average molecular weight obtained by GPC measurement in a toluene solvent was 18500 Da.

[ reference example 2]

A1L flask was charged with an average unit formula which was a white solid at 25 deg.C

(Me₃SiO_1/2)_0.46(SiO_4/2)_0.54(HO_1/2)_0.02

270.5g of a 55 mass% -xylene solution of the indicated polyorganosiloxane resin and 0.375g of a1, 3-divinyltetramethyldisiloxane solution of a1, 3-divinyltetramethyldisiloxane complex of platinum (the content of platinum metal is about 4000ppm) were uniformly stirred at room temperature (25 ℃ C.) to prepare a xylene solution containing 10ppm of the polyorganosiloxane resin (2) in terms of platinum metal by mass. Further, the polyorganosiloxane resin (2) does not soften/melt even when heated to 200 ℃, and is not hot-melt. Further, the weight average molecular weight obtained by GPC measurement in a toluene solvent was 11000 Da.

[ reference example 3]

A1L flask was charged with an average unit formula which was a white solid at 25 deg.C

(Me₃SiO_1/2)_0.475(SiO_4/2)_0.525(HO_1/2)_0.02

270.5g of a 55 mass% -xylene solution of the indicated polyorganosiloxane resin and 0.375g of a1, 3-divinyltetramethyldisiloxane solution of a1, 3-divinyltetramethyldisiloxane complex of platinum (the content of platinum metal is about 4000ppm) were uniformly stirred at room temperature (25 ℃ C.) to prepare a xylene solution containing 10ppm of the polyorganosiloxane resin (3) in terms of platinum metal by mass. Further, the polyorganosiloxane resin (3) does not soften/melt even when heated to 200 ℃, and is not hot-melt. Further, the weight average molecular weight obtained by GPC measurement under a toluene solvent was 7000 Da.

[ reference example 4]

A1L flask was charged with an average unit formula which was a white solid at 25 deg.C

(Me₃SiO_1/2)_0.49(SiO_4/2)_0.51(HO_1/2)_0.02

270.5g of a 55 mass% -xylene solution of the indicated polyorganosiloxane resin and 0.375g of a1, 3-divinyltetramethyldisiloxane solution of a1, 3-divinyltetramethyldisiloxane complex of platinum (the content of platinum metal is about 4000ppm) were uniformly stirred at room temperature (25 ℃ C.) to prepare a xylene solution containing 10ppm of the polyorganosiloxane resin (4) in terms of platinum metal by mass. Further, the polyorganosiloxane resin (4) does not soften/melt even when heated to 200 ℃, and is not hot-melt. Further, the weight average molecular weight obtained by GPC measurement under a toluene solvent was 4000 Da.

[ reference example 5]

To average unit formula

(Me₃SiO_1/2)_0.65(SiO_4/2)_0.35(HO_1/2)_0.01

The 55 mass% -xylene solution of the polyorganosiloxane resin shown above was dried under reduced pressure to remove xylene, and as a result, a polyorganosiloxane resin liquid at room temperature was obtained. Further, the weight average molecular weight obtained by GPC measurement under a toluene solvent was 1100 Da. 70.0g of the polyorganosiloxane resin was mixed with

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

30.0g of dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.09 mass%) at both ends of the molecular chain shown was mixed, and as a result, a mixture which was liquid at room temperature was obtained, and hot-melt property was not shown.

[ reference example 6]

A1L flask was charged with an average unit formula which was a white solid at 25 deg.C

(Me₂ViSiO_1/2)_0.05(Me₃SiO_1/2)_0.39(SiO_4/2)_0.56(HO_1/2)_0.02

270.5g of a 55 mass% -xylene solution of the indicated polyorganosiloxane resin and 0.375g of a1, 3-divinyltetramethyldisiloxane solution of a1, 3-divinyltetramethyldisiloxane complex of platinum (the content of platinum metal is about 4000ppm) were uniformly stirred at room temperature (25 ℃ C.) to prepare a xylene solution containing 10ppm of the polyorganosiloxane resin (6) in terms of platinum metal by mass. Further, the polyorganosiloxane resin (6) does not soften/melt even when heated to 200 ℃, and is not hot-melt. Further, the weight average molecular weight obtained by GPC measurement under a toluene solvent was 18000 Da.

[ reference example 7]

A1L flask was charged with an average unit formula which was a white solid at 25 deg.C

(Me₂ViSiO_1/2)_0.09(Me₃SiO_1/2)_0.43(SiO_4/2)_0.48(HO_1/2)_0.03

270.5g of a 55 mass% -xylene solution of the indicated polyorganosiloxane resin and 0.375g of a1, 3-divinyltetramethyldisiloxane solution of a1, 3-divinyltetramethyldisiloxane complex of platinum (the content of platinum metal is about 4000ppm) were uniformly stirred at room temperature (25 ℃ C.) to prepare a xylene solution containing 10ppm of the polyorganosiloxane resin (7) in terms of platinum metal by mass. Further, the polyorganosiloxane resin (7) does not soften/melt even when heated to 200 ℃, and is not hot-melt. Further, the weight average molecular weight obtained by GPC measurement under a toluene solvent was 2900 Da.

[ reference example 8: non-Hot-melt polyorganosiloxane resin particles (1)

The xylene solution of polyorganosiloxane resin (1) prepared in reference example 1 was granulated at 50 ℃ by a spray method using a spray dryer while removing xylene, to obtain spherical resin fine particles. The fine particles were cured in an oven set at 120 ℃ for 24 hours to prepare spherical non-heat-fusible polyorganosiloxane resin fine particles (1). The fine particles have a particle size of 5 to 10 μm when observed with an optical microscope, and the weight loss by heating is 0.8 wt% when exposed to 200 ℃ for 1 hour.

[ reference example 9: non-Hot-melt polyorganosiloxane resin particles (2)

The xylene solution of the polyorganosiloxane resin (2) prepared in reference example 2 was granulated at 50 ℃ by a spray method using a spray dryer while removing xylene, to obtain spherical resin fine particles. The fine particles were cured in an oven set at 120 ℃ for 24 hours to prepare spherical non-heat-fusible polyorganosiloxane resin fine particles (2). The fine particles have a particle size of 5 to 10 μm when observed with an optical microscope, and the weight loss by heating is 0.8 wt% when exposed to 200 ℃ for 1 hour.

[ reference example 10: non-Hot-melt polyorganosiloxane resin particles (3)

The xylene solution of the polyorganosiloxane resin (3) prepared in reference example 3 was granulated at 50 ℃ by a spray method using a spray dryer while removing xylene, to obtain spherical resin fine particles. The fine particles were cured in an oven set at 120 ℃ for 24 hours to prepare spherical non-heat-fusible polyorganosiloxane resin fine particles (3). The fine particles have a particle size of 5 to 10 μm when observed with an optical microscope, and the weight loss by heating is 0.7 wt% when exposed to 200 ℃ for 1 hour.

[ reference example 11: non-Hot-melt polyorganosiloxane resin particles (4)

The xylene solution of the polyorganosiloxane resin (4) prepared in reference example 4 was granulated at 50 ℃ by a spray method using a spray dryer while removing xylene, to obtain spherical resin fine particles. The fine particles were cured in an oven set at 120 ℃ for 24 hours to prepare spherical non-heat-fusible polyorganosiloxane resin fine particles (4). The fine particles have a particle size of 5 to 10 μm when observed with an optical microscope, and the weight loss by heating is 0.7 wt% when exposed to 200 ℃ for 1 hour.

[ reference example 12: non-Hot-melt polyorganosiloxane resin particles (6)

The xylene solution of the polyorganosiloxane resin (6) prepared in reference example 6 was granulated at 50 ℃ by a spray method using a spray dryer while removing xylene, to obtain spherical resin fine particles. The fine particles were cured in an oven set at 120 ℃ for 24 hours to prepare spherical non-heat-fusible polyorganosiloxane resin fine particles (6). The fine particles have a particle size of 5 to 10 μm when observed with an optical microscope, and the weight loss by heating is 0.7 wt% when exposed to 200 ℃ for 1 hour.

[ reference example 13: non-Hot-melt polyorganosiloxane resin particles (7)

The xylene solution of the polyorganosiloxane resin (7) prepared in reference example 7 was granulated at 50 ℃ by a spray method using a spray dryer while removing xylene, to obtain spherical resin fine particles. The fine particles were cured in an oven set at 120 ℃ for 24 hours to prepare spherical non-heat-fusible polyorganosiloxane resin fine particles (7). The fine particles have a particle size of 5 to 10 μm when observed with an optical microscope, and the weight loss by heating is 0.7 wt% when exposed to 200 ℃ for 1 hour.

[ example 1]

69.9g of non-hot-melt polyorganosiloxane resin fine particles (2) (vinyl content 0 mass%);

formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

29.9g of dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.09 mass%) at both ends of the molecular chain shown;

formula (II)

Me₃SiO(MeHSiO)₇(Me₂SiO)_6.5SiMe₃

0.2g of the organohydrogenpolysiloxane shown;

{ amount of 1.4 moles of silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane relative to 1 mole of vinyl groups in dimethylvinylsilylalkoxy-terminated dimethylpolysiloxane at both ends of the molecular chain },

82.8g of alumina (AES-12, Sumitomo chemical) having an average particle diameter of 0.44 μm; 166.1g of alumina (AL-M73A, manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 3.0. mu.m; 364.1g of alumina (AZ 35-125 manufactured by Micron Company, Nippon iron, Ltd.) having an average particle diameter of 37.4 μm; 1-ethynyl-1-cyclohexanol (in an amount of 1000ppm by mass relative to the present composition) was collectively charged into a small-sized pulverizer, and stirred at room temperature (25 ℃) for 1 minute to prepare a uniform curable particulate silicone composition. The present composition contains 0.10 mol% of vinyl groups per 100g of silicone component. The measurement results of the melt viscosity and the like of the composition are shown in table 1.

[ example 2]

68.5g of non-hot-melt polyorganosiloxane resin fine particles (3) (vinyl content 0 mass%);

1.5g of non-hot-melt polyorganosiloxane resin fine particles (7) (vinyl content: 3.10 mass%);

formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

29.7g of dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.09 mass%) at both ends of the molecular chain shown;

formula (II)

(HMe₂SiO_1/2)_0.67(SiO_4/2)_0.33

0.30g of the organohydrogenpolysiloxane resin (content of silicon atom-bonded hydrogen atom ═ 0.95 mass%) shown;

{ 1 mol of silicon atom-bonded hydrogen atom in the organohydrogenpolysiloxane relative to 1 mol of vinyl groups in the polyorganosiloxane resin fine particle (7) and the dimethylsilyloxy-terminated dimethylpolysiloxane at both molecular chain terminals },

82.8g of alumina (AES-12, Sumitomo chemical) having an average particle diameter of 0.44 μm; 166.1g of alumina (AL-M73A, manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 3.0. mu.m; 364.1g of alumina (AZ 35-125 manufactured by Micron Company, Nippon iron, Ltd.) having an average particle diameter of 37.4 μm; 1-ethynyl-1-cyclohexanol (in an amount of 1000ppm by mass relative to the present composition) was collectively charged into a small-sized pulverizer, and stirred at room temperature (25 ℃) for 1 minute to prepare a uniform curable particulate silicone composition. The present composition contains 0.27 mol% of vinyl groups per 100g of silicone component. The measurement results of the melt viscosity and the like of the composition are shown in table 1.

[ example 3]

68.6g of non-hot-melt polyorganosiloxane resin fine particles (4) (vinyl content 0 mass%);

1.5g of non-hot-melt polyorganosiloxane resin fine particles (7) (vinyl content 1.91 mass%);

formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

29.5g of dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.09 mass%) at both ends of the molecular chain shown;

formula (II)

Me₃SiO(MeHSiO)₇(Me₂SiO)_6.5SiMe₃

0.4g of the organohydrogenpolysiloxane shown;

{ 1 mol of silicon atom-bonded hydrogen atoms in the organohydrogenpolysiloxane resin was 1.0 mol based on 1 mol of vinyl groups in the polyorganosiloxane resin fine particle (7) and the dimethylsilyloxy-terminated dimethylpolysiloxane at both molecular chain terminals },

82.8g of alumina (AES-12, Sumitomo chemical) having an average particle diameter of 0.44 μm; 166.1g of alumina (AL-M73A, manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 3.0. mu.m; 364.1g of alumina (AZ 35-125 manufactured by Micron Company, Nippon iron, Ltd.) having an average particle diameter of 37.4 μm; 1-ethynyl-1-cyclohexanol (in an amount of 1000ppm by mass relative to the present composition) was collectively charged into a small-sized pulverizer, and stirred at room temperature (25 ℃) for 1 minute to prepare a uniform curable particulate silicone composition. The present composition contains 0.27 mol% of vinyl groups per 100g of silicone component. The measurement results of the melt viscosity and the like of the composition are shown in table 1.

[ example 4]

112.5g of alumina (AES-12 manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 0.44 μm; 234.0g of alumina (AL-M73A, manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 3.0 μ M; 553.1g of alumina (AZ 35-125, manufactured by Micron Company, Nippon iron, Ltd.) having an average particle diameter of 37.4 μm; having a viscosity of 23 mPas, formula

Me₂ViSiO(Me₂SiO)₂₉Si(OMe)₃

3.6g of the dimethylpolysiloxane (vinyl group content: 1.30% by mass) was put into a small-sized pulverizer, and the mixture was stirred at room temperature (150 ℃) for 1 minute to surface-treat alumina and return the temperature of the pulverizer to 25 ℃. Then, the process of the present invention is carried out,

67.1g of non-hot-melt polyorganosiloxane resin fine particles (3) (vinyl content 0 mass%);

formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

29.0g of dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.09% by mass) at both ends of the molecular chain shown;

formula (II)

(HMe₂SiO_1/2)_0.67(SiO_4/2)_0.33

0.30g of the organohydrogenpolysiloxane resin (content of silicon atom-bonded hydrogen atom ═ 0.95 mass%) shown;

{ the amount of 1.0 mol of silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane relative to 1 mol of vinyl groups in the dimethylvinylsiloxy group-blocked dimethylpolysiloxane at both ends and single end of the molecular chain },

1-ethynyl-1-cyclohexanol (in an amount of 1000ppm by mass relative to the present composition) was collectively charged into a small-sized pulverizer, and stirred at room temperature (25 ℃) for 1 minute to prepare a uniform curable particulate silicone composition. The present composition contains 0.3 mol% of vinyl groups per 100g of silicone component. The measurement results of the melt viscosity and the like of the composition are shown in table 1.

[ example 5]

Me₂ViSiO(Me₂SiO)₂₉Si(OMe)₃

67.1g of non-hot-melt polyorganosiloxane resin fine particles (4) (vinyl content 0 mass%);

formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

28.8g of dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.09 mass%) at both ends of the molecular chain shown;

formula (II)

Me₃SiO(MeHSiO)₇(Me₂SiO)_6.5SiMe₃

0.5g of the organohydrogenpolysiloxane;

{ the amount of 1.3 moles of silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane relative to 1 mole of vinyl groups in dimethylvinylsiloxy group-blocked dimethylpolysiloxane at both ends and single end of the molecular chain },

[ example 6]

Me₂ViSiO(Me₂SiO)₂₉Si(OMe)₃

66.8g of non-hot-melt polyorganosiloxane resin fine particles (4) (vinyl content 0 mass%);

0.5g of non-heat-meltable polyorganosiloxane resin fine particles (7) (vinyl content 1.91 mass%);

formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

28.8g of dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.09 mass%) at both ends of the molecular chain shown;

formula (II)

(HMe₂SiO_1/2)_0.67(SiO_4/2)_0.33

0.35g of the organohydrogenpolysiloxane resin (content of silicon atom-bonded hydrogen atom ═ 0.95 mass%) shown;

{ 1 mol of silicon atom-bonded hydrogen atom in the organohydrogenpolysiloxane relative to 1 mol of vinyl groups in the dimethylsilyloxyl-terminated dimethylpolysiloxane and the polyorganosiloxane resin fine particles (7) at both ends of the molecular chain and at the single end },

Comparative example 1

67.0g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 0 mass%);

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

33.0g of dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.09% by mass) at both ends of the molecular chain shown;

formula (II)

Me₃SiO(MeHSiO)₇(Me₂SiO)_6.5SiMe₃

0.2g of the organohydrogenpolysiloxane shown;

{ the amount of silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane resin was 1.4 mol based on 1 mol of vinyl groups in dimethylvinylsiloxy group-blocked dimethylpolysiloxane at both ends of the molecular chain },

82.8g of alumina (AES-12, Sumitomo chemical) having an average particle diameter of 0.44 μm; 166.1g of alumina (AL-M73A, manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 3.0. mu.m; 364.1g of alumina (AZ 35-125 manufactured by Micron Company, Nippon iron, Ltd.) having an average particle diameter of 37.4 μm; 1-ethynyl-1-cyclohexanol (in an amount of 1000ppm by mass relative to the present composition) was collectively charged into a small-sized pulverizer, and stirred at room temperature (25 ℃) for 1 minute to prepare a uniform curable particulate silicone composition. The present composition contains 0.1 mol% of vinyl groups per 100g of silicone component. The measurement results of the melt viscosity and the like of the composition are shown in table 1.

Comparative example 2

Non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 0 mass%) 62.5 g;

5.0g of non-hot-melt polyorganosiloxane resin fine particles (7) (vinyl content: 3.1 mass%);

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.09% by mass) 31.3g at both ends of the molecular chain shown;

formula (II)

Me₃SiO(MeHSiO)₇(Me₂SiO)_6.5SiMe₃

1.2g of the shown organic hydrogen polysiloxane;

{ 1 mol of silicon atom-bonded hydrogen atoms in the organohydrogenpolysiloxane resin was 1.2 mol based on 1 mol of vinyl groups in the polyorganosiloxane resin fine particle (7) and the dimethylsilyloxy-terminated dimethylpolysiloxane at both molecular chain terminals },

82.8g of alumina (AES-12, Sumitomo chemical) having an average particle diameter of 0.44 μm; 166.1g of alumina (AL-M73A, manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 3.0. mu.m; 364.1g of alumina (AZ 35-125 manufactured by Micron Company, Nippon iron, Ltd.) having an average particle diameter of 37.4 μm; 1-ethynyl-1-cyclohexanol (in an amount of 1000ppm by mass relative to the present composition) was collectively charged into a small-sized pulverizer, and stirred at room temperature (25 ℃) for 1 minute to prepare a uniform curable particulate silicone composition. The present composition contains 0.7 mol% of vinyl groups per 100g of silicone component. The measurement results of the melt viscosity and the like of the composition are shown in table 1.

Comparative example 3

60.2g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 0 mass%);

non-hot-melt polyorganosiloxane resin fine particles (6) (vinyl content 1.91 mass%) 7.0 g;

formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

Dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.09 mass%) 32.8g at both ends of the molecular chain shown;

formula (II)

(HMe₂SiO_1/2)_0.67(SiO_4/2)_0.33

0.65g of the organohydrogenpolysiloxane resin (content of silicon atom-bonded hydrogen atom ═ 0.95 mass%) shown;

{ 1 mol of silicon atom-bonded hydrogen atom in the organohydrogenpolysiloxane was 1.0 mol based on 1 mol of vinyl groups in the polyorganosiloxane resin fine particles (6) and the dimethylsilyloxy-terminated dimethylpolysiloxane at both molecular chain terminals },

82.8g of alumina (AES-12, Sumitomo chemical) having an average particle diameter of 0.44 μm; 166.1g of alumina (AL-M73A, manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 3.0. mu.m; 364.1g of alumina (AZ 35-125 manufactured by Micron Company, Nippon iron, Ltd.) having an average particle diameter of 37.4 μm; 1-ethynyl-1-cyclohexanol (in an amount of 1000ppm by mass relative to the present composition) was collectively charged into a small-sized pulverizer, and stirred at room temperature (25 ℃) for 1 minute to prepare a uniform curable particulate silicone composition. The present composition contains 0.6 mol% of vinyl groups per 100g of silicone component. The measurement results of the melt viscosity and the like of the composition are shown in table 1.

Comparative example 4

Me₂ViSiO(Me₂SiO)₂₉Si(OMe)₃

67.0g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 0 mass%);

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

33.0g of dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.09% by mass) at both ends of the molecular chain shown;

formula (II)

Me₃SiO(MeHSiO)₇(Me₂SiO)_6.5SiMe₃

0.5g of the organohydrogenpolysiloxane;

{ amount of 1.2 moles of silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane resin relative to 1 mole of vinyl groups in the below-mentioned one-terminal dimethylsilyloxy-terminated dimethylpolysiloxane and both terminals of the molecular chain },

Comparative example 5

Me₂ViSiO(Me₂SiO)₂₉Si(OMe)₃

67.0g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 0 mass%);

ViMe₂SiO(Me₂SiO)₃₀₀SiViMe₂

33.0g of dimethyl vinylsiloxy group-blocked dimethylpolysiloxane (content of vinyl group: 0.22% by mass) at both ends of the molecular chain shown;

formula (II)

Me₃SiO(MeHSiO)₇(Me₂SiO)_6.5SiMe₃

0.7g of the organohydrogenpolysiloxane shown;

{ amount of 1.1 mol of silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane resin relative to 1 mol of vinyl groups in the below-mentioned one-terminal dimethylsilyloxy-terminated dimethylpolysiloxane and both terminals of the molecular chain },

1-ethynyl-1-cyclohexanol (in an amount of 1000ppm by mass relative to the present composition) was collectively charged into a small-sized pulverizer, and stirred at room temperature (25 ℃) for 1 minute to prepare a uniform curable particulate silicone composition. The present composition contains 0.5 mol% of vinyl groups per 100g of silicone component. The measurement results of the melt viscosity and the like of the composition are shown in table 1.

[ Table 1]

[ conclusion ]

The curable silicone compositions of examples 1 to 6 of the present invention were hot-melt compositions having a low melt viscosity even when a large amount of alumina filler was blended, and the storage modulus of the cured products did not show an extremely high value, and an extremely decrease in tensile elongation was not observed. Further, the thermal conductivity of the resulting cured product increases with the alumina content. That is, the curable compositions of examples 1 to 6 provided cured products exhibiting appropriate flexibility in addition to good hot-melt properties, despite the extremely large amount of the functional inorganic filler.

On the other hand, comparative examples 1 to 5 each include a polyorganosiloxane resin having a weight average molecular weight of the polyorganosiloxane resin exceeding the value specified in the present invention, and comparative examples 1, 2, 3, and 5 each show an extremely low value of tensile elongation. In comparative example 4, the melting characteristics were extremely deteriorated. As described in reference example 5, when the weight average molecular weight of the polyorganosiloxane resin is less than the lower limit specified in the present invention, a hot-melt composition cannot be obtained.

< production example 1>

The curable silicone composition prepared in the form of pellets in example 1 was heated to 80 ℃ and heated, melted and kneaded using a twin-screw extruder, and supplied onto a releasable film (biwa line, manufactured by TAKARAIN CORPORATION) in the form of a semisolid softened product at a supply rate of 5 kg/hr, and laminated between two releasable films. Then, the laminate was stretched between rolls to form a laminate in which a hot-melt curable silicone sheet having a thickness of 500 μm was laminated between two release films, and the whole was cooled by a cooling roll set at-15 ℃. In this laminate, by separating the release film, a flat and homogeneous hot-melt curable silicone sheet can be obtained.

< production example 2>

The curable silicone composition prepared in the form of pellets as in example 1 was heated to 80 ℃ and melt-kneaded by heating using a twin-screw extruder, and was molded into a substantially sheet-like shape by a T-die (opening size: 800. mu. m.times.100 mm, heated at 80 ℃), supplied onto a releasable film (biwa liner, manufactured by TAKARAIN CORPORATION Co., Ltd.) at a supply rate of 5 kg/hr, cooled by a cooling roll set to-15 ℃ and laminated between two releasable films. Next, the laminate was stretched between rolls to form a laminate in which a hot-melt curable silicone sheet having a thickness of 500 μm was laminated between two release films. In this laminate, by separating the release film, a flat and homogeneous hot-melt curable silicone sheet can be obtained.

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