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 于 2020-03-18 设计创作，主要内容包括：本发明提供一种固化性有机硅组合物等,该固化性有机硅组合物具有热熔性,对难粘接的基材也牢固地粘接,二次成型等的固化物在室温至150℃左右的高温下的柔软性和强韧性特别优异,即使与引线框架等一体成型也供与不易产生翘曲、破损的固化物。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的特征在于,含有：(A1)作为分子整体不具有热熔性,含有至少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；(A2)分子内具有至少两个固化反应性的官能团的液态的链状聚有机硅氧烷；(B)杂氮硅三环衍生物或碳杂氮硅环衍生物；(C)固化剂；以及(D)功能性无机填料,(D)成分的含量为至少10体积％以上,该固化性有机硅组合物在200℃以下的温度下具有热熔性。(The present invention provides a curable silicone composition and the like, which has hot-melt property, firmly adheres to a substrate difficult to adhere, has excellent flexibility and toughness of a cured product such as secondary molding at a high temperature of about 150 ℃ and is used for a cured product difficult to warp and damage even if the cured product is integrally molded with a lead frame and the like. A curable silicone composition and use thereof, the curable silicone composition being characterized by containing: (A1) has no hot-melt property as a whole molecule and contains at least 20 mol% of SiO 4/2 A polyorganosiloxane resin of the siloxane unit shown; (A2) a liquid chain polyorganosiloxane having at least two curing-reactive functional groups in a molecule; (B) silatrane derivatives or carbosilatrane derivatives; (C) a curing agent; and (D) a functional inorganic filler, wherein the content of the component (D) is at least 10% by volume or more, and the curable silicone composition has a hot-melt property at a temperature of 200 ℃ or less.)

1. A curable silicone composition characterized by comprising:

(A1) 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;

(A2) a linear or branched polyorganosiloxane having at least two curing-reactive functional groups containing a carbon-carbon double bond in the molecule and being liquid at 25 ℃;

(B) a thickener selected from one or more of silatrane derivatives and silatrane derivatives;

(C) a curing agent; and

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

(D) the content of the component (B) is at least 10 vol% or more based on the whole composition,

the curable silicone composition is solid at 25 ℃ and has a hot melt property at a temperature of 200 ℃ or lower.

2. The curable silicone composition according to claim 1,

a cured product having a storage modulus at 25 ℃ of 500MPa or less is formed.

3. The curable silicone composition according to any one of claims 1 and 2,

a cured product having a tensile elongation of 50% or more as measured by the method specified in JIS K6251-2010 "vulcanized rubber and thermoplastic rubber-method for determining tensile characteristics".

4. The curable silicone composition according to claim 3,

(A1) at least a part or the whole of the component (A) is a mixture of polyorganosiloxane resins composed of (A1-1) and (A1-2),

(A1-1) has no thermofusible molecular structure as a whole, has no functional group containing a carbon-carbon double bond and having curing reactivity in the molecule, and contains at least 20 mol% or more of SiO in all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown; and

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

5. The curable silicone composition according to any one of claims 1 to 4, wherein,

(A2) the component (A2-1) 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.

6. The curable silicone composition according to any one of claims 1 to 5, wherein,

(A) the components are a mixture consisting of the following components:

(A1) 100 parts by mass of a polyorganosiloxane resin containing the following (A1-1) component and (A1-2) component in a mass ratio of 100: 0 to 25: 75;

(A1-1) has no thermofusible molecular structure as a whole, has no functional group containing a carbon-carbon double bond and having curing reactivity in the molecule, and contains at least 20 mol% or more of SiO in all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown;

(A1-2) has no thermofusible property in the 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 in the total siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown;

(A2-1) 10 to 200 parts by mass of 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.

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

(A1) the component (B) is a spherical resin fine particle having an average primary particle diameter of 1 to 10 μm.

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

(B) the component is selected from

One or more of silatrane derivatives represented by the following structural formula (1) and silatrane derivatives represented by the following structural formula (2),

[ chemical formula 1]

In the formula (1), R¹Are the same or different hydrogen atoms or alkyl groups; r²Is selected from the group consisting of hydrogen atoms, alkyl groups and radicals of the formula-R⁴-Si(OR⁵)_xR⁶ _(3-x)The same or different groups in the group consisting of the alkoxysilyl-containing organic groups represented, the-R⁴-Si(OR⁵)_xR⁶ _(3-x)In the formula, R⁴Is a divalent organic radical, R⁵Is an alkyl group having 1 to 10 carbon atoms, R⁶Is a substituted or unsubstituted monovalent hydrocarbon group, x is 1, 2 or 3, wherein R²At least one of (a) is the alkoxysilyl group-containing organic group; r³Is a group selected from the group consisting of substituted or unsubstituted monovalent hydrocarbon groups, C1-10 alkoxy groups, glycidoxyalkyl groups, oxiranylalkyl groups, acyloxyalkyl groups and alkenyl groups,

[ chemical formula 2]

In the formula (2), R¹Is alkyl, alkenyl or alkoxy, R²Are identical or different radicals selected from the group consisting of the radicals represented by the following formulae, R³Are identical or different hydrogen atoms or alkyl radicals,

[ chemical formula 3]

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.

9. The curable silicone composition according to any one of claims 1 to 8,

(C) the component (a) is more than one curing agent selected from the following (c1) or (c 2):

(c1) an organic peroxide;

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

the curable silicone composition contains component (C) in an amount necessary for curing the composition.

10. The curable silicone composition according to any one of claims 1 to 9, wherein,

(D) the component (B) is a reinforcing filler, a white pigment, a thermally conductive filler, an electrically conductive filler, a phosphor, or a mixture of at least two thereof.

11. The curable silicone composition according to any one of claims 1 to 10, wherein,

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

12. A curable silicone composition sheet formed from the curable silicone composition according to any one of claims 1 to 10, which is substantially flat and has a thickness of 10 to 1000 μm.

13. A film-like adhesive which is the curable silicone composition sheet according to claim 12.

14. A peelable laminate, comprising:

the curable silicone composition sheet according to claim 12, 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.

15. A cured product obtained by curing the curable silicone composition according to any one of claims 1 to 10.

16. A cured product according to claim 15, which is used as a member for a semiconductor device.

17. A semiconductor device comprising the cured product according to claim 15.

18. A method for producing a curable silicone composition in a granular form, the curable silicone composition being the curable silicone composition according to any one of claims 1 to 10,

the production method is characterized in that the components constituting the curable silicone composition are granulated by mixing only at a temperature not exceeding 50 ℃.

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

a step (I) in which the granular or sheet-like curable silicone composition according to claim 11 is heated to 100 ℃ or higher and melted;

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).

20. The method for molding a cured product according to claim 19, wherein,

the molding method comprises the following steps: a coating step of performing secondary molding and underfill of a semiconductor element at a time with a cured product obtained by curing the curable silicone composition according to any one of claims 1 to 10.

21. The method for molding a cured product according to claim 20, wherein,

the molding method comprises the following steps: a coating step of coating the surface of a semiconductor wafer substrate on which a semiconductor element is mounted alone or a plurality of semiconductor elements are mounted with a cured product obtained by curing the curable silicone composition according to any one of claims 1 to 10, and performing secondary molding so that gaps between the semiconductor elements are filled with the cured product.

22. A method for producing a curable silicone composition sheet according to claim 13, the method comprising:

step 1: a step of mixing the raw material components of the curable silicone composition according to any one of claims 1 to 10 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 hot-melt properties, is firmly bonded to a substrate which is difficult to bond, and has any form of granules, particles, and sheets. The present invention also relates to a cured product formed from the above-mentioned silicone composition, a method for molding the cured product, and a semiconductor device provided with the cured product.

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.

In the semiconductor device industry in recent years, nickel or gold, which is a difficult-to-bond material, tends to be used as a substrate, and a material used for packaging devices, which has excellent heat resistance and a low coefficient of linear expansion, is required to have a characteristic of being strongly bonded to these substrates. The present applicant has proposed, in patent documents 1 and 2, a hot-melt curable silicone composition for molding which can give a cured product that is relatively soft and has excellent flexibility. However, these compositions contain a large amount of functional inorganic filler, and therefore, they are sometimes not easily bonded to substrates such as gold and nickel which are difficult to bond, and there is still room for improvement.

On the other hand, patent document 3 reports that the adhesiveness at the time of low-temperature curing is improved by adding a silatrane (silatrane) derivative to a silicone adhesive having no hot-melt property. In addition, although the examples of patent document 4 disclose an adhesive composition obtained by adding a silane-based tackifier containing a silatrane derivative to a hot-melt silicone containing no functional inorganic filler, the superiority of the silatrane derivative in comparison with the silatrane derivative with a general silane compound is not described at all, nor suggested at all.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2018/030287 pamphlet

Patent document 2: international publication No. 2018/030286 pamphlet

Patent document 3: japanese patent laid-open publication No. 2001-19933

Patent document 4: japanese laid-open patent publication No. 2006-274007 (patent 4849814)

Disclosure of Invention

Problems to be solved by the invention

The purpose of the present invention is to provide a curable silicone composition that is hot-melt, has excellent melting properties even when a large amount of a functional inorganic filler is contained, has excellent workability and curing properties, and can form a cured product that can be firmly bonded to a material that is difficult to bond. Further, an object of the present invention is to provide a method for efficiently producing a curable silicone composition in any form of granular form, particulate form, and sheet form. The present invention also provides a member for a semiconductor device comprising a cured product of such a curable silicone composition, a semiconductor device having the cured product, and a method for molding the cured product.

Means for solving the problems

The present inventors have conducted intensive studies and as a result, have found that the above problems can be solved by a curable silicone composition characterized by containing:

(A1) 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;

(A2) a linear or branched polyorganosiloxane having at least two curing-reactive functional groups containing a carbon-carbon double bond in the molecule and being liquid at 25 ℃;

(B) a thickener selected from one or more of silatrane derivatives and silatrane derivatives;

(C) a curing agent; and

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

(D) the content of the component (B) is at least 10 vol% or more based on the whole composition,

the curable silicone composition is solid at 25 ℃ and has a hot melt property at a temperature of 200 ℃ or lower. The curable silicone composition may be in the form of a pellet or a sheet.

Further, 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 curable silicone composition of the present invention can be used in the form of a cured product, and can be used as a member for a semiconductor device.

The curable silicone composition and the cured product thereof of the present invention can be used in a semiconductor device, and a power semiconductor device, an optical semiconductor device, and a semiconductor device mounted on a flexible circuit board, each of which is formed from the cured product as an encapsulating material, a light reflecting material, or the like, are provided. In particular, the curable silicone composition of the present invention is excellent in gap filling properties when melted, and the cured product thereof is excellent in flexibility and toughness at room temperature to high temperature, and therefore, it is preferable to provide a semiconductor device in which semiconductor elements are collectively encapsulated by so-called mold underfill (molded underfill) or wafer molding (wafer molding); a semiconductor device substrate after packaging, in which a semiconductor device is packaged by the present cured product on a flexible circuit board using deformation (bending or the like).

The method for molding a curable silicone composition of the present invention includes at least the following steps.

A step (I) in which the granular or sheet-shaped curable silicone composition is heated to 100 ℃ or higher and melted;

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).

The molding method includes transfer molding, compression molding or injection molding, and the curable silicone composition of the present invention is preferably used as the molding material. The curable silicone composition of the present invention can be preferably used as a molding material for a cured product in the following manner: a so-called mold underfill method in which a covering step of performing secondary molding (overmolding) and underfill of a semiconductor element is performed at a time; a post-molding method of covering the surface of a semiconductor wafer substrate on which semiconductor elements are mounted and filling gaps between the semiconductor elements, and optionally a wafer injection molding method of collectively packaging large wafers such as 8 inches or 12 inches.

In particular, the curable silicone composition of the present invention, in particular, 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.

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 and curing properties, and can form a cured product that adheres strongly to substrates that are difficult to adhere to. Further, such a curable silicone composition can be produced only by a simple mixing step, and can be efficiently produced. The cured product of the present invention is useful as a member of a semiconductor device, and the use of the molding method of the present invention enables efficient production of these cured products depending on the application.

Detailed Description

[ curable Silicone composition ]

The curable silicone composition of the present invention is characterized by containing:

(A1) as molecular integratorsThe body does not have a hot-melt property and contains at least 20 mol% or more of SiO of all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown;

(A2) a linear or branched polyorganosiloxane having at least two curing-reactive functional groups containing a carbon-carbon double bond in the molecule and being liquid at 25 ℃;

(B) a thickener selected from one or more of silatrane derivatives and silatrane derivatives;

(C) a curing agent; and

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

the curable silicone composition is solid at 25 ℃ and has a hot melt property at a temperature of 200 ℃ or lower. In the present invention, unless otherwise specified, "having a hot-melt property" means that the resin has a softening point of 50 ℃ or higher, a melt viscosity at 150 ℃ (preferably a melt viscosity of less than 1000Pa · s), and a fluidity. On the other hand, when the softening point is 200 ℃ or higher, the softening point is equal to or higher than the normal use temperature for molding applications and the like, and therefore, the resin composition is defined as "not having hot-melt property".

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.

(A) The component (b) is a main component of the present composition and is a component for providing hot melt to the present composition. Further, since it has a curing reactive group containing a carbon-carbon double bond, it is cured by a curing agent as the component (C). Examples of the curing reaction include a hydrosilylation reaction and a radical reaction.

Examples of the hydrosilylation reactive group in the component (a) include: alkenyl groups having 2 to 20 carbon atoms such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl and the like; and silicon atoms bonded to hydrogen atoms. As the hydrosilylation reactive group, an alkenyl group is preferable. The alkenyl group may be linear or branched, and a vinyl group or a hexenyl group is preferable. (A) The component (b) preferably has at least two hydrosilylation-reactive groups in one molecule.

Examples of the silicon atom-bonded group other than the hydrosilylation-reactive group in the component (a) include: an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogenated aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an alkoxy group and a hydroxyl group. Specifically, examples of the following may be given: alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl; aryl groups such as phenyl, tolyl, xylyl, naphthyl, anthryl, phenanthryl, pyrenyl, and the like; aralkyl groups such as phenethyl and phenylpropyl; and groups in which some or all of the hydrogen atoms bonded to these groups are substituted with halogen atoms such as chlorine atoms and bromine atoms; alkoxy groups such as methoxy, ethoxy, and propoxy.

Further, as the radical reactive group in the component (a), there can be exemplified: alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl and the like; alkenyl groups having 2 to 20 carbon atoms such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl and the like; acryloyl group-containing groups such as 3-acryloyloxypropyl group and 4-acryloyloxybutyl group; a methacryloyl group-containing group such as 3-methacryloxypropyl group, 4-methacryloxybutyl group and the like; and silicon atoms bonded to hydrogen atoms. As the radical reactive group, an alkenyl group is preferable. The alkenyl group may be linear or branched, and a vinyl group or a hexenyl group is preferable. (A) The component (c) preferably has at least two radical-reactive groups in one molecule.

Examples of the silicon atom-bonded group other than the radical-reactive group in the component (a) include: examples of the haloalkyl group having 1 to 20 carbon atoms, the aryl group having 6 to 20 carbon atoms, the haloaryl group having 6 to 20 carbon atoms, the aralkyl group having 7 to 20 carbon atoms, the alkoxy group and the hydroxy group include the same groups as described above. In particular, methyl group and hydroxyl group are preferable.

In the present invention, the component (A) is required to be SiO containing at least 20 mol% or more of all siloxane units as the component (A1)_4/2A mixture of a polyorganosiloxane resin having siloxane units represented by the formula (A2) and a linear or branched polyorganosiloxane as the component (A2). This is because hot melt property is not exhibited even when the component monomers are used separately without preparing a mixture.

That is, the component (A) is specifically a mixture of the following (A1) and (A2),

(A1) SiO which is not hot-melt as a whole molecule and contains at least 20 mol% or more of all siloxane units_4/2A polyorganosiloxane resin of the siloxane unit shown; and

(A2) the polyorganosiloxane is 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.

These components are explained below.

[ (A1) ingredient ]

(A1) Component (A2), which is one of the main components of the composition used together with component (A2), is not hot-melt by itself, and contains at least 20 mol% or more of SiO based on the total siloxane units_4/2A polyorganosiloxane resin of the siloxane units shown or a mixture of polyorganosiloxane resins comprising the resin.

(A1) 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 (a1) does not show a heating melting behavior at a temperature of 200 ℃ or lower, and specifically means that it does not have a softening point and a melt viscosity. In the component (A1), the physical properties are not particularly limited in structure, and 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 an alkyl group and an alkenyl group having 1 to 10 carbon atoms such as a methyl group, and does not substantially contain an aryl group such as a phenyl group. When a large amount of phenyl groups or the like is contained, the above components may become hot-melt, and the coloring resistance of a cured product described later under heat aging (high temperature) may be reduced. The functional group bonded to a silicon atom in component (a1) is preferably a group selected from alkenyl groups such as methyl groups and vinyl groups, 70 to 100 mol%, more preferably 80 to 100 mol%, and particularly preferably 88 to 100 mol% of all the functional groups bonded to a silicon atom are methyl groups, and the other functional groups bonded to a silicon atom are alkenyl groups such as vinyl groups. Within the above range, the component (A1) can be designed not to be hot-melt, and the cured product thereof is particularly excellent in resistance to coloration at high temperatures. 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 the total siloxane units in the molecule_4/2Siloxane units as shown. These branched siloxane units account for at least 40 mol% or more of the total siloxane units, and particularly, preferably, are in the range of 40 to 90 mol%. In addition, R is a monovalent organic group, preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, and 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 preferably R does not substantially contain an aryl group such as a phenyl group from the viewpoint of technical effects. 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 of exposure, and it is particularly preferable to remove volatile low-molecular-weight components from the polyorganosiloxane resin so that the mass reduction rate becomes 2.0 mass% or less.

(A1) The component (a) does not necessarily have to contain a reactive functional group containing a carbon-carbon double bond group, and in this case, the reactive functional group of the component (a) is supplied from the component (a2) described later. When the content of the functional inorganic filler as the component (D) described later is large, the elastic modulus of the obtained cured product tends to be high, and therefore, it is preferable that the component (a1) does not contain a carbon-carbon double bond group, whereas when the content of the component (D) is small, the component (a1) preferably contains a carbon-carbon double bond in order to set the elastic modulus of the obtained cured product to an appropriate value. That is, the amount of the carbon-carbon double bond group is preferably controlled by combining the component (A1-1) described below with the component (A1-2) as the component (A1).

[ (A1-1) ingredient ]

The component (A1-1) in the present invention is a non-hot-melt polyorganosiloxane resin having no curing reactive functional group containing a carbon-carbon double bond in the molecule.

The component (A1-1) is a component which has no hot-melt property in the whole molecule, has no curing reactive functional group containing a carbon-carbon double bond in the molecule, and contains SiO in an amount of at least 20 mol% or more based on the total siloxane units_4/2The polyorganosiloxane resin having siloxane units shown is a component in which the component (A1) is used in combination with a linear or branched polyorganosiloxane as the component (A2) in a predetermined amount in the whole or part of the component (A1), thereby achieving a hot-melt property as the whole composition.

The component (A1-1) is a polyorganosiloxane resin which is solid in a solvent-free state and does not have a hot-melt property as a whole molecule. Herein, the term "not having a hot-melt property" means that the resin alone as the component (a1-1) does not show a heating melting behavior at a temperature of 200 ℃ or lower, specifically, means not having a softening point and a melt viscosity, as already described in the component (a 1).

The silicon atom-bonded functional groups in component (a1-1) are preferably methyl groups, and 70 mol% or more, more preferably 80 mol% or more, and particularly preferably 88 mol% or more of the total silicon atom-bonded functional groups are preferably methyl groups. Within the above range, the component (A1-1) can be designed to be a component which is not hot-melt and which is particularly excellent in the resistance to coloration at high temperatures of the cured product. The component (A1-1) may contain a small amount of a hydroxyl group or an alkoxy group.

The component (a1-1) does not have a curing reactive group containing a carbon-carbon double bond in the molecule, and therefore does not form a cured product itself, but has improved hot-melt properties as the whole composition and reinforcing effects on the cured product, and can be used as a part of the component (a) having curability.

The component (A1-1) is characterized in that the polyorganosiloxane resin 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 the total siloxane units in the molecule_4/2Siloxane units as shown. The siloxane unit is preferably 30 mol% or more, particularly preferably 40 mol% or more, and particularly preferably in the range of 40 to 65 mol% of the total siloxane units.

Preferably, the component (A1-1) is 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 and not containing a carbon-carbon double bond; 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: 0.10. ltoreq. a.ltoreq.0.60, 0. ltoreq. b.ltoreq.0.70, 0. ltoreq. c.ltoreq.0.80, 0.20. ltoreq. d.ltoreq.0.65, 0. ltoreq. e.ltoreq.0.05, and a + b + c + d 1)

In the above average unit formula, each R¹Independently 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, and the like. Here, all R in one molecule are preferred¹70 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, R¹Preferably, the aromatic group such as a phenyl group is not substantially contained. In the case where an aryl group such as a phenyl group is contained in a large amount,(A) the component itself is hot-melt, and the technical effects of the present invention may not be achieved, and the coloring resistance of the cured product at high temperature may be deteriorated.

In the formula, R²Is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. R²The alkyl group of (b) may be exemplified by a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group. Comprising said R²Functional group R of²O_1/2According to the hydroxyl or alkoxy in the component (A2-1-1).

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, etc.) of the resulting cured product does not become too low.

Wherein 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 can obtain a composition which is less tacky at room temperature. In the present invention, b may be 0, and is preferable.

Wherein c is represented by the general formula: r¹SiO_3/2Number of siloxane units of (a). The number satisfies 0. ltoreq. c.ltoreq.0.70, preferably 0. ltoreq. c.ltoreq.0.60. When c 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, c may be 0, and is preferable.

Wherein d represents SiO_4/2The number of the proportion of siloxane units of (b) is desirably 0.20. ltoreq. d.ltoreq.0.65, preferably 0.40. ltoreq. d.ltoreq.0.65, particularly preferably 0.50. ltoreq. d.ltoreq.0.65. Within this range, the composition containing the component exhibits good hot-melt properties as a whole, and the resulting cured product has excellent mechanical strengthA composition which is free from stickiness as a whole and has good workability can be obtained.

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. The sum of a, b, c, and d, which is the sum of the siloxane units, is 1.

The component (A1-1) is a polyorganosiloxane resin having the above-mentioned characteristics, and may be finely divided for the purpose of improving the handling properties. Specifically, the polyorganosiloxane resin fine particles are preferably in the form of regular spherical particles having an average primary particle diameter of 1 to 20 μm as measured by a laser diffraction/scattering method or the like. By using the fine particle component, the workability in the production of the present composition into any of granular, granulated and flaky forms is improved. In addition, when the fine particulate component (A1-1) is obtained, it is preferable to granulate a substance mixed with the component (A1-2) having a curing reactivity described later, or to granulate the component (C) described later, for example, a hydrosilylation catalyst, together with the component (A1).

Examples of the method for forming the polyorganosiloxane resin into fine particles include: a method of pulverizing the polyorganosiloxane using a pulverizer, and a method of directly granulating the polyorganosiloxane 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 organosilicon in the presence of a solvent, for example, there are mentioned: spraying with a spray dryer, or micronization with a twin-screw kneader or a belt dryer (belt dryer). In the present invention, from the viewpoint of the workability at room temperature, the efficiency in production, and the workability of the composition, it is particularly preferable to use the hot-melt polyorganosiloxane resin fine particles in a regular spherical shape obtained by spraying with a spray dryer.

By using a spray dryer or the like, a component (A1-1) having a spherical shape and an average primary particle diameter of 1 to 500 μm can be produced. 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 polyorganosiloxane resin 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.

For the purpose of obtaining a uniform (a1-1) component, a solvent may be used in the above step within a range not to inhibit 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.

[ (A1-2) ingredient ]

The component (A1-2) is preferably 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, and the like. And, 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 above range, the composition containing the present component can realize 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 the technical effect 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 (A1-2) itself is hot-melt, and the technical effects of the present invention may not be achieved, and SiO may be contained in a cured product_4/2The effect of reinforcing the cured product peculiar to the base is reduced.

In the formula, R²Is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. R²The alkyl group of (b) may be exemplified by a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group. Comprising said R²Functional group R of²O_1/2According to the hydroxyl or alkoxy in the component (A1-2).

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 obtained solidThe mechanical strength (hardness, elongation, etc.) of the compound does not become too low.

Wherein 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 can obtain a composition which is less tacky at room temperature.

Wherein c is represented by the general formula: r³SiO_3/2Number of siloxane units of (a). The number satisfies 0. ltoreq. c.ltoreq.0.80, preferably 0. ltoreq. c.ltoreq.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 not tacky. In the present invention, c may be 0, and is preferable.

Wherein d represents SiO_4/2The number of the proportion of siloxane units of (b) is desirably 0.00. ltoreq. d.ltoreq.0.65, 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, good hot melt properties may not be achieved as the whole composition, and the technical effects of the present invention may not be sufficiently achieved.

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. If e is not more than the upper limit of the range, a material that realizes good hot-melt performance as the whole composition can be obtained. The sum of a, b, c, and d, which is the sum of the siloxane units, is 1.

The component (A1-2) is a polyorganosiloxane resin having the above-mentioned characteristics, and may be made into fine particles for improving handling properties, as in the case of the component (A1-1). Specifically, the polyorganosiloxane resin particles are preferably in the form of regular spherical polyorganosiloxane resin particles having an average primary particle diameter of 1 to 20 μm as measured by a laser diffraction/scattering method or the like, and the use of the above-mentioned fine particle component improves the workability in the production of the composition into any of granular, granular and sheet forms. In addition, when the fine particulate component (A1-2) is obtained, it is preferable to granulate a substance mixed with the component (A1-1) having curing reactivity, which will be described later, and to granulate the component (C), which will be described later, for example, a hydrosilylation catalyst, together with the component (A1). The method of micronization was the same as that of component (A1-1).

As described above, the ratio of the amount of the component (A1-1) to the amount of the component (A1-2) depends on the amount of the component (D) to be described later. The preferred mass ratio of the component (A1-1) to the component (A1-2) may be in the range of 100: 0 to 25: 75, preferably in the range of 100: 0 to 60: 40, and more preferably in the range of 100: 0 to 55: 45. The component (A1-1) does not have curability, but when the component (A1-2) is added in a small amount to the present composition and used in combination, the elastic modulus at high temperature 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 (A1-1) added and the amount of the component (A1-2) used can be appropriately adjusted to achieve a preferable elastic modulus and flexibility. For example, when the amount of the functional inorganic filler to be added is large, or when it is desired to reduce the elastic modulus of the resulting cured product as much as possible, the composition can be blended with only the component (A1-1) without adding the component (A1-2).

Removal of volatile low molecular weight components from component [ (A1) ]

The component (A1-1) and the component (A1-2) form volatile low molecular weight components in the production process. In particular M₄The structure of Q will consist of M units (R)³ ₃SiO_1/2) And Q unit (SiO)_4/2) The resulting polyorganosiloxane resin is polymerized as a by-product. The present structure has an effect of remarkably reducing the hardness of a cured product formed from the composition of the present invention. Said poly(s)The organosiloxane resin is polymerized in the presence of a highly compatible organic solvent, and the organic solvent is removed by drying under reduced pressure or the like to obtain an individual polyorganosiloxane resin, except that M₄The structure of Q has a high compatibility with the polyorganosiloxane resin 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 after the structure is integrally molded with a base material such as a semiconductor, when the structure is removed by exposure to a high temperature, the volume of the cured product is reduced, the hardness is significantly increased, the size of the molded product is changed, and warpage or the like occurs. Therefore, for the use of the present invention, it is necessary to remove M in advance before the molding step with the base material, that is, at the time point of the raw material₄A structure of Q.

Examples of the method for removing the structure include: a method of removing the organic solvent together with the above-mentioned organic solvent by means of 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 (A1-1) and the component (A1-2) 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 (A1-1) and the component (A1-2) by a twin-screw kneader or the like set to about 200 ℃. In addition, when the component (A1-1) and the component (A1-2) are processed into spherical powder, the powder can be made by removing the organic solvent by a spray dryer, but volatile components cannot be removed by this method. 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.

[ (A2) ingredient ]

(A2) Component (A1), which is one of the main components of the present composition used together with component (A1), 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.

(A2) The component (a) needs to have a curing reactive group containing a carbon-carbon double bond in the molecule, and when the component (a1) does not have a carbon-carbon double bond, the curing reactive group of the component (a) is supplied from the component (a 2). The carbon-carbon double bond is a functional group which is hydrosilylation-reactive, radical-reactive, or organic peroxide-curable, and forms a cured product by a crosslinking reaction with another component. Examples of such a curing reactive group include an alkenyl group and an acryloyl group, the same groups as described above are exemplified, and a vinyl group or a hexenyl group is particularly preferable.

(A2) Component (A) is a linear or branched polyorganosiloxane which is liquid at 25 ℃ C (room temperature), and when mixed with component (A1) which is solid at room temperature, the hot melt properties are exhibited throughout the composition. The structure may be a siloxane unit having a 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) is preferably a branched polyorganosiloxane

(A2-1) a linear polydiorganosiloxane represented by the following structural formula.

R⁴ ₃SiO(SiR⁴ ₂O)_kSiR⁴ ₃

(wherein each R is⁴Independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, wherein R in one molecule⁴At least two of (a) are alkenyl groups, k is a number of 20 to 5000)

Preferably, the silicone polymer is a linear polydiorganosiloxane having one alkenyl group at each end 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, diTolyl 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. 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 temperatures may be deteriorated. Particularly preferably, the polymer chain has one alkenyl group such as a vinyl group at each of both ends of the polymer chain, and the other R group⁴Is methyl.

In the formula, k is a number of 20 to 5000, preferably a number of 30 to 3000, and particularly preferably a number of 45 to 800. When k is not less than the lower limit of the above range, a granular composition having less stickiness 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.

[ mixture comprising non-Hot-melt polyorganosiloxane resin particles ]

When used as the component (A) of the present invention comprising the above-mentioned component (A1-1), component (A1-2) and component (A2-1), the amount of the component (A2-1) is preferably within the range of 10 to 200 parts by mass based on 100 parts by mass of the polyorganosiloxane resin (total) containing the component (A1-1) and the component (A1-2) in a mass ratio of 100: 0 to 25: 75 relative to the component (A1). Here, the carbon-carbon double bond as the curing reactive group is supplied from the component (A1-2) and the component (A2-2), but the amount of the functional group needs to be appropriately controlled by the kind and the amount of the component (D) to be described later. In particular, when the amount of component (D) added to the composition is 30 vol% or more, the composition preferably contains 0.05 to 1.50 mol% of carbon-carbon double bonds per 100g of the silicone component. When the amount of component (D) added in the composition is less than the lower limit, curability and curing speed may decrease. When the amount of the component (D) in the composition exceeds the upper limit, particularly when a large amount of a functional filler is blended in the composition, the cured product may be significantly embrittled.

The combination of the components (A1-1 and (A2) is not limited, and may be adjusted as appropriate depending on the type and amount of the component (D) to be described later. When the amount of the component (D) is large, it is preferable to use a component having a relatively low molecular weight as one of the components (a1-1 and 2) and (a2) in order to improve the melt characteristics of the obtained composition, but when the component (a2) having a low molecular weight is used, flexibility and toughness of the obtained cured product tend to be lowered regardless of the type of the component (a 1). Therefore, it is preferable to combine the low molecular weight components (A1-1 and-2) and the high molecular weight component (A2). On the other hand, when the amount of component (D) is small, the surface tackiness of the resulting composition can be suppressed by combining high molecular weight components (A1-1, -2) and high molecular weight component (A2).

(B) The component (C) is a thickener which is a characteristic of the present invention, and is at least one component selected from the group consisting of silatrane derivatives and silatrane derivatives. This component can significantly improve the cured adhesiveness to a substrate particularly difficult to adhere to.

The silatrane derivative is disclosed in the above-mentioned patent document 3 (Japanese patent laid-open No. 2001-019933),

is a silatrane derivative shown in the following structural formula (1).

[ chemical formula 1]

{ formula (1) { wherein R¹Are identical or different hydrogen atoms or alkyl radicals, R²Is selected from the group consisting of hydrogen atoms, alkyl groups and radicals of the formula-R⁴-Si(OR⁵)_xR⁶ _(3-x)(in the formula, R⁴Is a divalent organic radical, R⁵Is an alkyl group having 1 to 10 carbon atoms, R⁶Is a substituted or unsubstituted monovalent hydrocarbon group, and x is 1, 2 or 3. ) Containing alkoxy groupsIdentical or different radicals from the group consisting of silylic organic radicals, where R²At least one of (A) is the alkoxysilyl group-containing organic group, R³Is a group selected from the group consisting of substituted or unsubstituted monovalent hydrocarbon groups, alkoxy groups having 1 to 10 carbon atoms, glycidoxyalkyl groups, oxiranylalkyl groups, acyloxyalkyl groups and alkenyl groups. }

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

In the above formulaR³R 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.

Examples of such silatrane derivatives include the following compounds.

[ chemical formula 2]

[ chemical formula 3]

[ chemical formula 4]

[ chemical formula 5]

[ chemical formula 6]

[ chemical formula 7]

[ chemical formula 8]

[ chemical formula 9]

[ chemical formula 10]

[ chemical formula 11]

[ chemical formula 12]

The carbonitridimensional silicon ring derivative is a carbonitridi silicon ring derivative represented by the following general formula, which is cyclized by a reaction, particularly an alcohol exchange reaction, of an alkoxysilane having an amino group-containing organic group with an alkoxysilane having an epoxy group-containing organic group by the method described in Japanese patent application laid-open No. 10-195085.

[ chemical formula 13]

{ 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.

[ chemical formula 14]

(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. )

}

As such a carbonitridimensionalised cyclic derivative, a carbonitridised cyclic derivative having a silicon atom-bonded alkoxy group or a silicon atom-bonded alkenyl group in one molecule, as shown in the following structures, can be preferably used.

[ chemical formula 15]

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

(B) The amount of the component (b) is not particularly limited, but is preferably in the range of 0.1 to 1.0% by mass, more preferably 0.2 to 1.0% by mass, based on the whole composition, from the viewpoint of improving the adhesiveness to a substrate which is difficult to adhere. The amount of the component (B) may be in the range of 0.1 to 50 parts by mass or 0.1 to 40 parts by mass based on 100 parts by mass of the total of the components (A1).

[ (C) ingredient ]

(C) The component (a) is a curing agent for curing the component (a), 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) An organic peroxide;

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

(c1) the organic peroxide is a component which cures the component (a) by heating, and examples thereof include: alkyl peroxides, diacyl peroxides, peroxyesters, and peroxycarbonates.

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 peroxytrimethylhexanoate.

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 relative to 100 parts by mass of the component (A).

(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 the carbon-carbon double bond in the component (a) 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 (c2) 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). In particular, in the case of applications other than the molding step described later, the curable silicone composition is formed from 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 curing reactive functional group containing a carbon-carbon double bond in the compositionThe organohydrogenpolysiloxane is preferably an organohydrogenpolysiloxane resin as follows from the viewpoint of curing speed, moldability and curability because of a small content of (b): is included as RSiO_3/2The monoorganosilalkoxy units represented by (T units, R is a monovalent organic group or a silicon atom-bonded hydrogen atom) or 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 the molecular end has M^HAnd (4) units.

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 R⁵Is the same or different univalent hydrocarbon group or hydrogen atom with 1-10 carbon atoms and no aliphatic unsaturated carbon bonds, 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 the same monovalent hydrocarbon groups as those described above. In another aspect, R²Is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R²The alkyl group of (b) may be exemplified by a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group. Comprising said R²Functional group R of²O_1/2According to the hydroxyl or alkoxy groups in the composition.

Wherein l, m, n and p are numbers satisfying the following: l is more than or equal to 0.1 and less than or equal to 0.80, m is more than or equal to 0 and less than or equal to 0.5, n is more than or equal to 0 and less than or equal to 0.8, p is more than or equal to 0 and less than or equal to 0.6, q is more than or equal to 0 and less than or equal to 0.05, wherein n + p>0.1, and l + m + n + p ═ 1. When the present composition is used in the molding step, the organohydrogenpolysiloxane resin as a part of component (d2) is preferably M^HMT resin, M^HMTT^HResin, M^HMTQ resin, M^HMQ resin, M^HMTT^HQ、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. ltoreq. l 1. ltoreq.0.80, and 0.20. ltoreq. p 1. ltoreq.0.90.

Similarly, the organohydrogenpolysiloxane that is part of component (c2) may include a linear polydiorganosiloxane, organohydrogenpolysiloxane, or polydiorganosiloxane-organohydrogensiloxane copolymer, which is blocked at the molecular chain end by a silicon atom-bonded hydrogen atom or trimethylsiloxy group. 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 a part of the component (c2) is an amount sufficient for curing the curable silicone composition of the present invention, and is an amount in which the molar ratio of silicon atom-bonded hydrogen atoms in the organohydrogenpolysiloxane to curing-reactive functional groups (for example, alkenyl groups such as vinyl groups) containing carbon-carbon double bonds in the component (a) is 0.5 or more, preferably in the range of 0.5 to 20. In particular, when the component (c2) contains the aforementioned organohydrogenpolysiloxane resin, the molar ratio of silicon atom-bonded hydrogen atoms in the organohydrogenpolysiloxane resin to the curing-reactive functional groups containing carbon-carbon double bonds in the component (a) is preferably in the range of 0.5 to 20, or in the range of 1.0 to 10.

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. As the platinum group catalyst, there can be exemplified: 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. As the alkenylsiloxane, there may be exemplified: 1, 3-divinyl-1, 1,3, 3-tetramethyldisiloxane, 1,3,5, 7-tetramethyl-1, 3,5, 7-tetravinylcyclotetrasiloxane, alkenylsiloxanes in which a part of the methyl groups of these alkenylsiloxanes is 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 of the complex. 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 by mass, 0.01 to 100ppm by mass, or 0.01 to 50ppm by mass, 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 preferably contained in the fine particles in advance when the polyorganosiloxane resin fine particles such as component (A1-1) and component (A1-2) are produced, from the viewpoint of the storage stability of the curable silicone composition. However, it is preferable that the entire mixture constituting the fine particles alone have no curing reactivity.

The curable silicone composition of the present invention contains, in addition to the above-described components (a) to (C), a functional inorganic filler (D) in order to improve the problem of tackiness at room temperature of the entire composition, and in the case of curing at high temperature after heating and melting (hot melting), to provide a cured product having a desired function and excellent hardness and toughness at room temperature to high temperature.

[ (D) component ]

The component (D) in the present invention is a functional inorganic filler, preferably a filler having no softening point or at least one of no softening points at 50 ℃ or lower, and may be a component which imparts mechanical properties and other properties to a cured product of the present composition in order to improve the workability of the present composition. Examples of the component (D) include: inorganic fillers, organic fillers and mixtures thereof, preferably inorganic fillers. Examples of the inorganic filler include: reinforcing fillers, white pigments, thermally conductive fillers, electrically conductive fillers, phosphors, and mixtures of at least two thereof. Further, as the organic filler, there can be exemplified: 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, an adhesive, and a light-reflecting material, it is preferable to incorporate a reinforcing filler as the component (D) from the viewpoint of imparting mechanical strength to a cured product and improving the protective property or the adhesive property. Examples of the reinforcing filler include: fumed silica, precipitated silica, fused silica, fired silica, fumed titania, quartz, calcium carbonate, diatomaceous earth, alumina, aluminum hydroxide, zinc oxide, zinc carbonate. In addition, these reinforcing fillers may also be surface-treated by: organoalkoxysilanes such as methyltrimethoxysilane; organohalosilanes such as trimethylchlorosilane; organic silazanes such as hexamethyldisilazane; and siloxane oligomers 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. 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.

(D) The component (D) may be any component having an arbitrary particle diameter, but when it is desired to impart gap-filling properties to the composition, it is preferable to use a component having an average particle diameter of 10 μm or less, and when it is desired to increase the amount of the component (D) to be added as much as possible from the viewpoint of imparting functionality, it is preferable to combine components having different particle diameters in order to improve the sealing properties of the filler.

In the present composition, the surface treatment of the component (D) may be performed in order to improve the melting characteristics of the obtained composition. (D) The component (D) is preferably treated with a specific surface treatment agent, and particularly preferably treated with a surface treatment agent in an amount of 0.1 to 2.0 mass%, 0.1 to 1.0 mass%, 0.2 to 0.8 mass% based on the total mass of the component (D). By treating component (D) with the surface treatment agent in the above-mentioned treatment amount, there is an advantage that component (D) can be stably incorporated into the composition at a high volume%. The surface treatment method may be any desired method such as a homogeneous mixing method (dry method) using mechanical force or a wet mixing method using a solvent.

As examples of these surface treatment agents, for example, there may be mentioned: methyl hydrogen polysiloxane, silicone resin, metal soap and silane coupling agent; fluorine compounds such as perfluoroalkylsilanes and perfluoroalkylphosphate salts, and particularly preferred are the following silicone-based surface treatment agents. When a silane-based surface treatment agent such as methyltrimethoxysilane or phenyltrimethoxysilane is selected as the surface treatment agent of the component (D), the hot-melt property of the entire composition may be impaired, and the component (D) may not be stably blended in the above-mentioned volume% content. In addition, when an alkyltrialkoxysilane having an octyl long-chain alkyl group is selected as the surface treatment agent, the composition tends to be hot-melt and the stability of the component (D) in blending, but the strength of a cured product obtained by curing the composition of the present invention may be deteriorated, which may cause cracking or molding failure.

On the other hand, the silatrane derivative and the carbosilatrane derivative as the component (B) have alkoxy groups in the same manner as those of the silane compounds, but have the following advantages: even when the surface-treating agent is mixed with the surface-treating agent, the composition does not have an influence of deteriorating the melt property of the composition and the strength of a cured product, and the composition does not have an adverse effect even when the surface-treating agent is used in combination or mixed with the surface-treating agent.

Examples of the organosilicon compound used as the surface treatment agent include low-molecular-weight organosilicon compounds such as silanes, silazanes, siloxanes, and the like, and organosilicon polymers or oligomers such as polysiloxanes, polycarbosiloxanes, and 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.

Particularly preferred examples of the silicone-based surface treatment agent include silicone-based surface treatment agents having at least one polysiloxane structure and hydrolyzable silane group in the molecule. Most preferably, a silicone-based surface treatment agent having at least one polysiloxane structure and a hydrolyzable silane group in the molecule is preferably used, and examples thereof include:

structural formula (1):

R'_n(RO)_3-nSiO-(R'₂SiO)_m-SiR'_n(RO)_3-n

or

Structural formula (2):

R'₃SiO-(R'₂SiO)_m-SiR'_n(RO)_3-n

the polyorganosiloxanes having linear alkoxysilyl group terminals are shown. Wherein R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms (═ methyl group, ethyl group or propyl group), and R' is independently an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogenated aryl group having 6 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, and the same groups as described above are exemplified. n is a number in the range of 0 to 2, m is a number in the range of 2 to 200, and m may be a number in the range of 2 to 150.

(D) The component (A) may contain silicone fine particles not conforming to the above-mentioned components (A1-1 and-2), and the stress relaxation property and the like can be improved or adjusted as desired. 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, 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" and "EP Powder series" manufactured by Toray Dow, and "KMP series" manufactured by shin-Etsu chemical industries, Inc.

The silicone elastomer fine particles may be surface-treated. Examples of the surface treatment agent include: methyl hydrogen polysiloxane, silicone resin, metal soap, silane coupling agent, inorganic oxide such as silica and titanium oxide, fluorine compound such as perfluoroalkylsilane and perfluoroalkyl phosphate ester salt, and the like.

When the present composition is used as a wavelength conversion material for an LED, a phosphor may be blended as the component (D) in order to convert the emission wavelength from the optical semiconductor element. 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). Examples of the oxide-based phosphor include: yttrium, aluminum, garnet-based YAG-based green to yellow light-emitting phosphors containing cerium ions; a TAG yellow phosphor of terbium, aluminum, or garnet type containing cerium ion; silicate green to yellow light-emitting phosphors containing cerium and europium ions.Examples of the oxynitride-based phosphor include silicon, aluminum, oxygen, and nitrogen-based SiAlON-based red to green light-emitting phosphors containing europium ions. Examples of the nitride-based phosphor include calcium, strontium, aluminum, silicon, and nitrogen-based CASN-based red-emitting phosphors containing europium ions. As the sulfide-based phosphor, a ZnS-based green-emitting phosphor containing copper ions and aluminum ions is exemplified. As the oxysulfide phosphor, Y containing europium ion is exemplified₂O₂S is a red-emitting phosphor. In the present composition, two or more of these phosphors may be used in combination.

The present composition may contain a thermally conductive filler or an electrically conductive filler in order to impart thermal conductivity or electrical conductivity to the cured product. Examples of the thermally conductive filler or the electrically conductive filler include: fine metal powder of gold, silver, nickel, copper, aluminum, or the like; 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, a metal oxide-based powder or a metal nitride-based powder is preferable, and an alumina powder, a zinc oxide powder, or an aluminum nitride powder is particularly preferable.

(D) The content of the component (b) is not limited, but is at least 10 vol% or more, preferably 20 vol% or more, more preferably 30 vol% or more, and particularly preferably in the range of 30 to 90 vol% of the entire composition, from the viewpoint of imparting functionality to the resulting cured product.

The present composition may contain, as other optional components, hot-melt fine particles, a curing retarder, and a thickener, as long as the object of the present invention is not impaired.

As the thermally meltable fine particles other than the component (a), one or more selected from various thermally meltable synthetic resins, waxes, fatty acid metal salts and the like can be used. The wax component exhibits a low kinematic viscosity at high temperatures (150 ℃) and forms a melt with excellent fluidity. Further, by using the components (a) to (D) in combination, the wax component in the melt formed from the present composition rapidly diffuses into the entire composition at a high temperature, whereby the following effects are exhibited: the viscosity of the entire composition and the surface of the substrate to which the molten composition is applied 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.

The wax component may be a petroleum wax such as paraffin, as long as the wax component satisfies the above-mentioned conditions of dropping point and kinematic viscosity at the time of melting, and from the viewpoint of the technical effect of the present invention, a hot-melt component containing a fatty acid metal salt and a fatty acid ester of erythritol derivative is preferable, and a metal salt of a higher fatty acid such as stearic acid, palmitic acid, oleic acid, isononanoic acid, pentaerythritol tetrastearate, dipentaerythritol adipic acid stearate, glycerol tri-18-hydroxystearate, pentaerythritol tetrastearate (pentaerythritol full-stearate) is particularly preferable. 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.

The wax component is particularly preferably a fatty acid metal salt or erythritol derivative having a free fatty acid content of 5.0% or less, and particularly preferably a fatty acid metal salt or erythritol derivative having a free fatty acid content of 4.0% or less and 0.05% to 3.5%. 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 wax component used may be in the range of 0.01 to 5.0 parts by mass, 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. If the amount of the wax component used exceeds the above upper limit, the adhesiveness and mechanical strength of a cured product obtained from the curable silicone composition of the present invention may become insufficient. If the amount used is less than the lower limit, sufficient fluidity during heating and melting may not be achieved.

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, but is preferably within a range of 10 to 10000ppm by mass relative to the present composition.

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.

[ storage modulus of cured product ]

Specifically, a cured product obtained by curing the composition has a storage modulus (G') at 25 ℃ of 500MPa or less. The cured product is flexible, has excellent adhesion to a base material such as a semiconductor substrate and follow-up properties, and can suppress the occurrence of defects such as breakage, peeling, voids, and the like of a semiconductor element to be packaged even in the packaging application of a semiconductor element on the assumption of deformation, such as a flexible semiconductor substrate which has been introduced in recent years. In particular, in applications where high elongation and follow-up to deformation are required, the value of the storage modulus (G') at 25 ℃ is preferably 400MPa or less, and more preferably 300MPa or less.

[ tensile elongation of cured product ]

Furthermore, the tensile elongation of a cured product obtained by curing the composition of the present invention, as measured by the method specified in JIS K6251-2010 "vulcanized rubber and thermoplastic rubber-determination of tensile Properties", is required to be 30% or more. The cured product is flexible, has excellent adhesion to a base material such as a semiconductor substrate and follow-up properties, and can suppress the occurrence of defects such as breakage, peeling, voids, and the like of a semiconductor element to be packaged even in the packaging application of a semiconductor element on the assumption of deformation, such as a flexible semiconductor substrate which has been introduced in recent years. In particular, in applications where high elongation and conformability to deformation are required, the tensile elongation is preferably 40% or more, and more preferably 50% or more.

[ use of the present composition ]

The composition can be obtained in any form of granules, granules and tablets by the production process thereof. In the case of using as granules, the present composition in the form of granules can be efficiently produced by tableting it. 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.

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 100 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 compositions in tablet form can be produced as follows: the curable particulate composition obtained by the above method is integrated at a low temperature by a single-screw or twin-screw continuous kneader, and then formed into a predetermined thickness by two rolls or the like.

[ 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.

Here, the sheet-like member formed of the curable silicone composition may have a thickness of 1mm or less and be a film-like adhesive. That is, the laminate may contain a releasable film-like adhesive held by the base film, and is preferable. Since the film-like adhesive has hot-melt properties, it can be used as an adhesive for temporarily fixing a semiconductor member or the like, and can also be used as a die attach film.

In addition, a sheet-like member formed of a curable silicone composition may be integrally molded with a base material by compression molding, press molding, or the like, and in this case, the sheet-like member may be molded with a film-like base material remaining on one surface thereof and used as a mold release film for preventing adhesion to a mold during molding.

The present compositions are 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 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 ℃.

[ Process for producing particulate curable Silicone composition ]

The present composition can be produced by powder-mixing components (a) to (D) and optionally other components at a temperature lower than the softening point of component (a) to produce a granular composition. 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;

and a step 2: a step of kneading the mixture obtained in step 1 while heating and melting the mixture at a temperature of 50 ℃ or higher;

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 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 is a laminate having the following structure: a curable silicone sheet having a thickness of 10 to 2000 [ mu ] m, which is substantially flat and contains a polyorganosiloxane resin, a curing agent and a functional filler, and which has a hot melt property, 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 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).

The present composition can be preferably molded by a molding method comprising the following steps: a covering step of performing secondary molding and underfill of the semiconductor element at a time (so-called mold underfill method). In addition, the present composition can also be preferably molded by a molding method including the following steps, because of the above-mentioned characteristics: and a coating step of coating the surface of the semiconductor wafer substrate on which the semiconductor element is mounted alone or a plurality of semiconductor elements are mounted, and performing secondary molding (so-called wafer injection) so that the gap between the semiconductor elements is filled with the cured product.

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 an organic peroxide is used as the component (C), the heating temperature is preferably 150 ℃ or higher, or 170 ℃ or higher.

The cured product obtained by curing the present composition preferably has a D-type durometer hardness of 10 or more at 25 ℃. The type D durometer hardness can be determined by a type D durometer in accordance with JIS K6253-1997 "hardness test method for vulcanized rubber and thermoplastic rubber".

[ use of the composition ]

The composition is hot-melt, and has excellent fluidity, workability and curability when melted (hot-melt), and is therefore suitable as a semiconductor sealing agent or underfill; a sealing agent and an underfill agent for power semiconductors such as SiC and GaN; an encapsulant or light-reflecting material for an optical semiconductor such as a light-emitting diode, a photodiode, a phototransistor, or a laser diode; an adhesive, a potting agent, a protective agent, and a coating agent for electric/electronic use. 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 an encapsulant for semiconductors using a mold underfill method or a wafer injection 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.

[ 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 gap-filling properties, and the cured product has the above-mentioned flexibility at room temperature, high stress relaxation properties, bending elongation, and the like. 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, a light-reflecting material for an optical semiconductor device, and an adhesive/bonding member for a semiconductor device.

The semiconductor device including the member made of the cured product of the present invention is not particularly limited, and is preferably a power semiconductor device, an optical semiconductor device, and a semiconductor device mounted on a flexible circuit board.

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, a phenyl group, and a vinyl group. The softening point and the melt viscosity of the curable silicone compositions of the examples and comparative examples were measured by the following methods. Further, the curable silicone composition was heated at 150 ℃ for 2 hours to prepare a cured product, and the adhesion of various substrates was measured by the following method. The results are shown in Table 1.

[ softening Point of curable Silicone composition ]

Shaping the curable Silicone composition intoCylindrical pellets of (a). The pellets were placed on a hot plate set at 25 to 100 ℃ and pressed continuously from above for 10 seconds with a load of 100g, and after removing the load, the deformation amount of the pellets was measured. The deformation in the height direction is 1mm or lessThe above temperature is set as the softening point.

[ 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.

[ die shear Strength ]

The curable silicone composition was disposed in about 500mg per site on various substrates of 25mm × 75 mm. Then, a 10mm square chip (chip) made of glass having a thickness of 1mm was covered on the composition, and the composition was cured by heating for 2 hours in a state of thermocompression bonding with a 1kg plate at a temperature of 150 ℃. Then, the temperature was cooled to room temperature, and the die shear strength was measured by a shear strength measuring apparatus (bond tester SS-100KP, manufactured by West advanced Co., Ltd.).

[ 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 was measured at-50 ℃ to 250 ℃ using a rheometer ARES (TA Instruments, Japan K.K.), and the value at 25 ℃ was read. 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".

Hereinafter, polyorganosiloxane resins containing a hydrosilylation catalyst were prepared by the methods shown in reference examples 1 and 2, 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 4 to 6. 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".

[ reference example 1]

A1L flask was charged with an average unit formula of 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 of the polyorganosiloxane resin (1) containing 10ppm by mass of platinum metal. Further, the polyorganosiloxane resin (1) does not soften/melt even when heated to 200 ℃, and is not hot-melt.

[ reference example 2]

A1L flask was charged with an average unit formula of 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 of the polyorganosiloxane resin (2) containing 10ppm by mass of platinum metal. Further, the polyorganosiloxane resin (2) does not soften/melt even when heated to 200 ℃, and is not hot-melt.

[ reference example 3: 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 particles were cured in an oven set at 120 ℃ for 24 hours to prepare spherical non-heat-fusible polyorganosiloxane resin 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 0.7 wt% when exposed to 200 ℃ for 1 hour.

[ reference example 4: 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 particles were cured in an oven set at 120 ℃ for 24 hours to prepare spherical non-heat-fusible polyorganosiloxane resin 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.

[ example 1]

60.2g of non-hot-melt polyorganosiloxane resin fine particles (2) (vinyl content: 0 mass%) were mixed,

7.0g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 1.91% by mass),

Formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

Shown as molecular chain both ends dimethyl vinyl silanyloxy terminated polydimethylsiloxane (vinyl content 0.09 mass%) 32.8g,

Formula (II)

(HMe₂SiO_1/2)_0.67(SiO_4/2)_0.33

The organohydrogenpolysiloxane resin (content of silicon atom-bonded hydrogen atom ═ 0.95 mass%) was 0.65g

{ the amount of hydrogen atoms bonded to silicon atoms in the aforementioned organohydrogenpolysiloxane in an amount of 1.1 mol based on 1 mol of vinyl groups in the polyorganosiloxane resin fine particles (1) and the dimethylsiloxy-terminated polydimethylsiloxane at both molecular chain terminals }),

1.1g of bis (trimethoxysilylpropoxymethyl) vinylsilatrane,

273.0g of alumina (AES-12 manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 0.44 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, granular curable silicone composition. The results of measurement of the softening point and the like of the composition are shown in table 1.

[ example 2]

60.2g of non-hot-melt polyorganosiloxane resin fine particles (2) (vinyl content: 0 mass%) were mixed,

7.0g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 1.91% by mass),

Formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

Shown as molecular chain both ends dimethyl vinyl silanyloxy terminated polydimethylsiloxane (vinyl content 0.09 mass%) 32.8g,

Formula (II)

(HMe₂SiO_1/2)_0.67(SiO_4/2)_0.33

The organohydrogenpolysiloxane resin (content of silicon atom-bonded hydrogen atom ═ 0.95 mass%) was 0.65g

{ the amount of hydrogen atoms bonded to silicon atoms in the aforementioned organohydrogenpolysiloxane in an amount of 1.1 mol based on 1 mol of vinyl groups in the polyorganosiloxane resin fine particles (1) and the dimethylsiloxy-terminated polydimethylsiloxane at both molecular chain terminals }),

1.1g of bis (trimethoxysilylpropoxymethyl) allylsilatrane,

273.0g of alumina (AES-12 manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 0.44 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, granular curable silicone composition. The results of measurement of the softening point and the like of the composition are shown in table 1.

[ example 3]

56.4g of non-hot-melt polyorganosiloxane resin fine particles (2) (vinyl content: 0 mass%) were mixed,

10.3g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 1.91% by mass),

Formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

33.3g of dimethylsiloxy-terminated polydimethylsiloxane (vinyl content: 0.09% by mass) was placed at both ends of the molecular chain,

Formula (II)

Me₃SiO(MeHSiO)₇(Me₂SiO)_6.5SiMe₃

1.57g of the organohydrogenpolysiloxane shown

{ the amount of hydrogen atoms bonded to silicon atoms in the aforementioned organohydrogenpolysiloxane in an amount of 1.3 moles based on 1 mole of vinyl groups in the polyorganosiloxane resin fine particles (1) and the dimethylsiloxy-terminated polydimethylsiloxane at both molecular chain terminals } ],

1.1g of Carboaza silacyclic derivative represented by the following structural formula

[ chemical formula 16]

205.0g of alumina (AES-12 manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 0.44 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, granular curable silicone composition. The results of measurement of the softening point and the like of the composition are shown in table 1.

Comparative example 1

60.2g of non-hot-melt polyorganosiloxane resin fine particles (2) (vinyl content: 0 mass%) were mixed,

7.0g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 1.91% by mass),

Formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

Shown as molecular chain both ends dimethyl vinyl silanyloxy terminated polydimethylsiloxane (vinyl content 0.09 mass%) 32.8g,

Formula (II)

(HMe₂SiO_1/2)_0.67(SiO_4/2)_0.33

The organohydrogenpolysiloxane resin (content of silicon atom-bonded hydrogen atom ═ 0.95 mass%) was 0.65g

{ the amount of hydrogen atoms bonded to silicon atoms in the aforementioned organohydrogenpolysiloxane in an amount of 1.1 mol based on 1 mol of vinyl groups in the polyorganosiloxane resin fine particles (1) and the dimethylsiloxy-terminated polydimethylsiloxane at both molecular chain terminals }),

Condensation reaction product of silanol group-terminated methyl vinyl siloxane oligomer and 3-glycidoxypropyltrimethoxysilane having viscosity of 30 mPas at 25 DEG C

1.1g of alumina (AES-12 manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 0.44 μm 273.0g and 1-ethynyl-1-cyclohexanol (in an amount of 1000ppm by mass based on the composition) were put into a small-sized pulverizer, and stirred at room temperature (25 ℃ C.) for 1 minute to prepare a uniform, granular curable silicone composition. The results of measurement of the softening point and the like of the composition are shown in table 1.

Comparative example 2

60.2g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content: 0 mass%) were mixed,

7.0g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 1.91% by mass),

Formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

Shown as molecular chain both ends dimethyl vinyl silanyloxy terminated polydimethylsiloxane (vinyl content 0.09 mass%) 32.8g,

Formula (II)

(HMe₂SiO_1/2)_0.67(SiO_4/2)_0.33

The organohydrogenpolysiloxane resin (content of silicon atom-bonded hydrogen atom ═ 0.95 mass%) was 0.65g

{ the amount of hydrogen atoms bonded to silicon atoms in the aforementioned organohydrogenpolysiloxane in an amount of 1.1 mol based on 1 mol of vinyl groups in the polyorganosiloxane resin fine particles (1) and the dimethylsiloxy-terminated polydimethylsiloxane at both molecular chain terminals }),

1.1g of 3-glycidoxypropyltrimethoxysilane,

273.0g of alumina (AES-12 manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 0.44 μm and 1-ethynyl-1-cyclohexanol (in an amount of 1000ppm by mass relative to the composition) were collectively charged into a small-sized pulverizer, and stirred at room temperature (25 ℃) for 1 minute to prepare a uniform, granular curable silicone composition. The results of measurement of the softening point and the like of the composition are shown in table 1.

Comparative example 3

56.4g of non-hot-melt polyorganosiloxane resin fine particles (2) (vinyl content: 0 mass%) were mixed,

10.3g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 1.91% by mass),

Formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

33.3g of dimethylsiloxy-terminated polydimethylsiloxane (vinyl content: 0.09% by mass) was placed at both ends of the molecular chain,

Formula (II)

Me₃SiO(MeHSiO)₇(Me₂SiO)_6.5SiMe₃

1.57g of the organohydrogenpolysiloxane shown

{ the amount of hydrogen atoms bonded to silicon atoms in the aforementioned organohydrogenpolysiloxane in an amount of 1.3 moles based on 1 mole of vinyl groups in the polyorganosiloxane resin fine particles (1) and the dimethylsiloxy-terminated polydimethylsiloxane at both molecular chain terminals } ],

(Me₂ViSiO_1/2)_0.2(MeEpSiO_2/2)_0.25(PhSiO_3/2)_0.55(HO_1/2)_0.005

1.1g of the epoxy group-containing polysiloxane,

205.0g of alumina (AES-12 manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 0.44 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, granular curable silicone composition. The results of measurement of the softening point and the like of the composition are shown in table 1.

Comparative example 4

56.4g of non-hot-melt polyorganosiloxane resin fine particles (2) (vinyl content: 0 mass%) were mixed,

10.3g of non-hot-melt polyorganosiloxane resin fine particles (1) (vinyl content 1.91% by mass),

Formula (II)

ViMe₂SiO(Me₂SiO)₈₀₀SiViMe₂

33.3g of dimethylsiloxy-terminated polydimethylsiloxane (vinyl content: 0.09% by mass) was placed at both ends of the molecular chain,

Formula (II)

Me₃SiO(MeHSiO)₇(Me₂SiO)_6.5SiMe₃

1.57g of the organohydrogenpolysiloxane shown

{ the amount of hydrogen atoms bonded to silicon atoms in the aforementioned organohydrogenpolysiloxane in an amount of 1.3 moles based on 1 mole of vinyl groups in the polyorganosiloxane resin fine particles (1) and the dimethylsiloxy-terminated polydimethylsiloxane at both molecular chain terminals } ],

1.1g of N-phenyl-3-aminopropyltrimethoxysilane,

205.0g of alumina (AES-12 manufactured by Sumitomo chemical Co., Ltd.) having an average particle diameter of 0.44 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, granular curable silicone composition. The results of measurement of the softening point and the like of the composition are shown in table 1.

[ conclusion ]

The curable silicone compositions of examples 1 to 3 of the present invention have good hot-melt properties, are firmly adhered to any substrate, and form cured products having appropriate softness. Therefore, it is expected that cured products obtained using these curable silicone compositions can be suitably used for packaging semiconductor devices in which gold, epoxy glass, or the like is often used.

On the other hand, in comparative examples 1 to 4 which do not satisfy the requirements in terms of the composition of the present invention, good adhesion to aluminum was exhibited, but the adhesive did not firmly adhere to nickel, gold, or epoxy glass, which is a substrate difficult to adhere to. In addition, in the case of comparative examples 1 and 3, etc., in which silane compounds other than the silatrane derivative were used, the melting characteristics were deteriorated. This is considered to be a result of the thickener in comparative examples 1 and 3 adversely affecting the surface treatment of the functional filler.

< 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.