阅读说明：本技术 加成固化型硅酮组合物、光反射材料用硅酮固化物、光反射材料及光半导体装置 (Addition curing type silicone composition, silicone cured product for light reflecting material, and optical semiconductor device ) 是由 木村真司 于 2020-02-14 设计创作，主要内容包括：本发明的技术问题在于提供一种加成固化型硅酮组合物,其具有高流动性,其给予即使在薄膜中光反射性能也优异的固化物。该加成固化型硅酮组合物以特定的量含有：(A)特定的直链状的有机聚硅氧烷、(B)特定的三维网状有机聚硅氧烷树脂、(C)特定的有机氢聚硅氧烷、(D)包含铂族金属的氢化硅烷化催化剂、及(E)下述式(2)所表示的化合物。[化学式1]<Image he="189" wi="700" file="DDA0002384349160000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>式中,R<Sup>3</Sup>独立地为烷氧基,R<Sup>4</Sup>为烷氧基或烷基,n为0或1,m为1～10的整数。(The present invention addresses the problem of providing an addition-curable silicone composition that has high fluidity and that gives a cured product that exhibits excellent light-reflecting properties even in a thin film. The addition curing type silicone composition contains the following components in specific amounts: (A) a specific linear organopolysiloxane, (B) a specific three-dimensional network organopolysiloxane resin, (C) a specific organohydrogenpolysiloxane, (D) a hydrosilylation catalyst containing a platinum group metal, and (E) a compound represented by the following formula (2). [ chemical formula 1] In the formula, R 3 Independently is alkoxy, R 4 Is alkoxy or alkyl, n is 0 or 1, and m is an integer of 1 to 10.)

1. An addition-curable silicone composition characterized by containing:

(A) 50 to 97 parts by mass of a straight-chain organopolysiloxane having in one molecule at least 2 alkenyl groups bonded to silicon atoms and having a viscosity of 0.05 to 100 pas at 25 ℃;

(B) 3 to 50 parts by mass of a three-dimensional network organopolysiloxane resin which is waxy or solid at 23 ℃ and represented by the average unit formula (1), wherein the total of the component (A) and the component (B) is 100 parts by mass,

(R² ₃SiO_1/2)_a(R¹R² ₂SiO_1/2)_b(R¹R²SiO)_c(R² ₂SiO)_d(R¹SiO_3/2)_e(R²SiO_3/2)_f(SiO₂)_g(1)

in the formula, R¹Independently represents an alkenyl group, R²Independently represents a monovalent hydrocarbon group free of addition-reactive carbon-carbon double bonds, all R²At least 80 mol% of (a) is methyl, and a, b, c, d, e, f, g satisfy 1>a≥0、1>b≥0、1>c≥0、1>d≥0、1>e≥0、1>f is not less than 0 and 1>g is not less than 0, and b + c + e>0、e+f+g>0. And a + b + c + d + e + f + g is a number of 1;

(C) an organohydrogenpolysiloxane having at least 2 hydrogen atoms bonded to silicon atoms per molecule and having no addition-reactive carbon-carbon double bond, in which the amount of the hydrogen atoms bonded to silicon atoms is 0.4 to 4.0 moles per 1 mole of alkenyl groups in the component (A) and the component (B);

(D) a hydrosilylation catalyst containing a platinum group metal in an amount of 0.1 to 1000ppm in terms of the mass of the platinum group metal relative to the total mass of the component (A), the component (B), and the component (C);

(E) 20 to 200 parts by mass of titanium dioxide powder having a surface treated with siloxane; and

(F) 0.1 to 10 parts by mass of a compound represented by the following formula (2),

[ chemical formula 1]

In the formula, R³Independently is alkoxy, R⁴Is alkoxy or alkyl, n is 0 or 1, and m is an integer of 1 to 10.

2. A cured silicone material for a light-reflecting material, which is a cured product of the addition-curable silicone composition according to claim 1.

3. The cured silicone material for light-reflecting material according to claim 2, wherein the reflectance with respect to light having a wavelength of 430 to 800nm is 90% or more when the thickness is 0.3mm or less.

4. A light-reflecting material comprising the cured silicone material according to claim 2 or 3.

5. An optical semiconductor device comprising the light reflective material according to claim 4.

Technical Field

The present invention relates to an addition-curable silicone composition, a silicone cured product for a light-reflecting material, and an optical semiconductor device.

Background

In recent years, an optical semiconductor element such as a light emitting diode (hereinafter, referred to as "LED") has been widely used as an indicator or a light source because of its high efficiency of light emission and its excellent driving characteristics and repeated lighting characteristics. In particular, white LEDs are widely used as backlights for display devices or flash lamps for cameras, and further, for illumination purposes. In such a light-emitting device, a material that reflects emitted light is mounted in order to improve the light extraction efficiency in the irradiation direction.

Lead frames used in LEDs conduct current and, in many cases, also have a function of reflecting light. Specifically, silver plating having a good light reflectance is preferably used.

However, silver plating has a problem that the silver plating is oxidized or sulfurized by contact with an external gas, and the reflectance is easily lowered. Gold plating or aluminum is sometimes used to prevent corrosion by external gas, but both gold plating and aluminum have a problem of low visible light reflectance.

Further, although a light reflecting resin, ceramic, or the like is used as the insulating member, a function of reflecting light is also required for the portion, but it is not necessarily only a substance having a high light reflectance.

In order to solve such a problem, a method of thinly coating a resin having a high light reflectance (hereinafter, referred to as "white coating material") on the lead frame or the insulating member may be considered.

Patent documents 1 and 2 propose a light reflecting material containing an epoxy resin and a metal oxide as components. However, these materials are inferior in high-temperature durability and light durability to cured products made of silicone resins and metal oxides.

Patent documents 3 and 4 propose a light reflecting material containing a silicone resin and a metal oxide as components. However, these materials have excellent durability, but are not suitable as white coating materials because the composition itself does not have fluidity to be wet-spread.

Disclosure of Invention

Technical problem to be solved by the invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide an addition-curable silicone composition which has high fluidity and gives a cured product excellent in light reflection performance even in a thin film.

Means for solving the problems

In order to achieve the above object, the present invention provides an addition-curable silicone composition comprising:

(A) 50 to 97 parts by mass of a straight-chain organopolysiloxane having in one molecule at least 2 alkenyl groups bonded to silicon atoms and having a viscosity of 0.05 to 100 pas at 25 ℃;

(B) 3 to 50 parts by mass of a three-dimensional network organopolysiloxane resin which is waxy or solid at 23 ℃ and represented by the average unit formula (1) (wherein the total of the component (A) and the component (B) is 100 parts by mass),

(R² ₃SiO_1/2)_a(R¹R² ₂SiO_1/2)_b(R¹R²SiO)_c(R² ₂SiO)_d(R¹SiO_3/2)_e(R²SiO_3/2)_f(SiO₂)_g(1)

in the formula, R¹Independently represents an alkenyl group, R²Independently represents a monovalent hydrocarbon group free of addition-reactive carbon-carbon double bonds, all R²At least 80 mol% of (a) is methyl, and a, b, c, d, e, f, g satisfy 1>a≥0、1>b≥0、1>c≥0、1>d≥0、1>e≥0、1>f is not less than 0 and 1>g is not less than 0, and b + c + e>0、e+f+g>0. And a + b + c + d + e + f + g is a number of 1;

(C) an organohydrogenpolysiloxane having at least 2 hydrogen atoms bonded to silicon atoms per molecule and having no addition-reactive carbon-carbon double bond, in which the amount of the hydrogen atoms bonded to silicon atoms is 0.4 to 4.0 moles per 1 mole of alkenyl groups in the component (A) and the component (B);

(D) a hydrosilylation catalyst containing a platinum group metal in an amount of 0.1 to 1000ppm in terms of the mass of the platinum group metal relative to the total mass of the component (A), the component (B), and the component (C);

(E) 20 to 200 parts by mass of titanium dioxide powder having a surface treated with siloxane; and

(F) 0.1 to 10 parts by mass of a compound represented by the following formula (2),

[ chemical formula 1]

In the formula, R³Independently is alkoxy, R⁴Is alkoxy or alkyl, n is 0 or 1, and m is an integer of 1 to 10.

The addition curing type silicone composition has high fluidity at room temperature, and further provides a cured product with excellent light reflection performance even in a thin film.

The present invention also provides a silicone cured product for a light-reflecting material, which is a cured product of the addition-curable silicone composition.

The cured product has excellent light reflection performance in a thin film.

Preferably, the cured product has a reflectance of 90% or more with respect to light having a wavelength of 430 to 800nm at a thickness of 0.3mm or less.

The cured product has a reflectance of a predetermined value or more and is more excellent in light reflection performance in a thin film.

The present invention provides a light-reflecting material comprising the cured silicone material for light-reflecting material.

The light reflecting material has excellent light reflecting performance even if it is thin.

Further, the present invention provides an optical semiconductor device having the above-mentioned light reflecting material.

The semiconductor device can maintain high light extraction efficiency for a long period of time.

Effects of the invention

The addition-curable silicone composition of the present invention has high fluidity at room temperature, and therefore has excellent workability and handling properties, and can be applied in a film form by being wetted and spread by a part of the composition applied on a horizontal plate, for example. Furthermore, a silicone cured product obtained by thermally curing the composition is excellent in light reflection performance even in a thin film. Therefore, the cured product is useful as a light-reflecting material for optical semiconductors, particularly a light-reflecting coating material.

Drawings

FIG. 1 is a cross-sectional view schematically showing an example of an optical semiconductor device using a cured silicone material for a light-reflecting material of the present invention.

Description of the reference numerals

1: a light emitting element; 2: a lead electrode; 3: a die bonding material; 4: gold thread; 5: a light-reflecting resin; 6: a white coating material; 7: an optical semiconductor device.

Detailed Description

As described above, there is a demand for development of an addition curing type silicone composition which has high fluidity and gives a cured product excellent in light reflection performance even in a thin film.

The present inventors have conducted extensive studies and as a result, have found that the above-mentioned technical problems can be achieved in an addition-curable silicone composition containing the following components (a) to (F), and that the composition is suitable as a light-reflecting material, and have completed the present invention.

That is, the present invention is an addition-curable silicone composition containing:

(A) 50 to 97 parts by mass of a straight-chain organopolysiloxane having in one molecule at least 2 alkenyl groups bonded to silicon atoms and having a viscosity of 0.05 to 100 pas at 25 ℃;

(B) 3 to 50 parts by mass of a three-dimensional network organopolysiloxane resin which is waxy or solid at 23 ℃ and represented by the average unit formula (1) (wherein the total of the component (A) and the component (B) is 100 parts by mass),

(R² ₃SiO_1/2)_a(R¹R² ₂SiO_1/2)_b(R¹R²SiO)_c(R² ₂SiO)_d(R¹SiO_3/2)_e(R²SiO_3/2)_f(SiO₂)_g(1)

in the formula, R¹Independently represents an alkenyl group, R²Independently represents a monovalent hydrocarbon group free of addition-reactive carbon-carbon double bonds, all R²At least 80 mol% of (a) is methyl, and a, b, c, d, e, f, g satisfy 1>a≥0、1>b≥0、1>c≥0、1>d≥0、1>e≥0、1>f is not less than 0 and 1>g is not less than 0, and b + c + e>0、e+f+g>0. And a + b + c + d + e + f + g is a number of 1;

(C) an organohydrogenpolysiloxane having at least 2 hydrogen atoms bonded to silicon atoms per molecule and having no addition-reactive carbon-carbon double bond, in which the amount of the hydrogen atoms bonded to silicon atoms is 0.4 to 4.0 moles per 1 mole of alkenyl groups in the component (A) and the component (B);

(D) a hydrosilylation catalyst containing a platinum group metal in an amount of 0.1 to 1000ppm in terms of the mass of the platinum group metal relative to the total mass of the component (A), the component (B), and the component (C);

(E) 20 to 200 parts by mass of titanium dioxide powder having a surface treated with siloxane; and

(F) 0.1 to 10 parts by mass of a compound represented by the following formula (2),

[ chemical formula 2]

In the formula, R³Independently is alkoxy, R⁴Is alkoxy or alkyl, n is 0 or 1, and m is an integer of 1 to 10.

The present invention will be described in detail below, but the present invention is not limited thereto. In the present specification, "Me" represents a methyl group and "Vi" represents a vinyl group. The viscosity is a value at 25 ℃ measured using a rotational viscometer.

< addition curing type silicone composition >

Hereinafter, each component will be described in detail.

[ (A) component ]

(A) The component (b) is a component which is a main skeleton of the composition of the present invention, and is a linear organopolysiloxane having at least 2 alkenyl groups in one molecule.

(A) The viscosity of the component (A) is 0.05 to 100 pas, preferably 0.1 to 50 pas, and more preferably 0.5 to 10 pas. When the viscosity is less than 0.05 pas, the strength of the cured product is weakened, and when the viscosity is 100 pas or more, the fluidity is lowered.

Examples of the alkenyl group in the component (a) include a vinyl group, an allyl group, a butenyl group, a pentenyl group, and a hexenyl group, and a vinyl group is particularly preferable. The number of alkenyl groups contained in one molecule is at least 2, preferably 2 to 20, and more preferably 2 to 5. When the number of alkenyl groups contained in one molecule is less than 2, the hardness of the cured product becomes insufficient, and when it is 20 or less, the cured product does not become brittle.

(A) The hydrocarbon group bonded to the silicon atom other than the alkenyl group in the component (A) is not particularly limited, and is, for example, an unsubstituted or substituted monovalent alkyl group having usually 1 to 12, preferably 1 to 10 carbon atoms. Examples of the unsubstituted or substituted monovalent alkyl group include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a heptyl group; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; halogenated alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3, 3-trifluoropropyl, which are substituted with a part or all of the hydrogen atoms of these groups by halogen atoms such as chlorine atom, fluorine atom, and bromine atom, etc., preferably methyl.

Specific examples of the component (a) include organopolysiloxanes represented by the following formulae.

ViMe₂SiO(SiMe₂O)_pSiMe₂Vi

ViMe₂SiO(SiMeViO)_q(SiMe₂O)_pSiMe₂Vi

Vi₂MeSiO(SiMe₂O)_pSiMeVi₂

Vi₃SiO(SiMe₂O)_pSiVi₃

Vi₂MeSiO(SiMeViO)_q(SiMe₂O)_pSiMeVi₂

Vi₃SiO(SiMeViO)_q(SiMe₂O)_pSiVi₃

Me₃SiO(SiMeViO)_r(SiMe₂O)_pSiMe₃

Wherein p, q and r are integers of p.gtoreq.0, q.gtoreq.0 and r.gtoreq.2, and satisfy the viscosity range of the component (A).

Specific examples of the linear organopolysiloxane of the component (a) include compounds represented by the following formulae.

ViMe₂SiO(SiMe₂O)₂₀₀SiMe₂Vi

ViMe₂SiO(SiMe₂O)₄₅₀SiMe₂Vi

(A) The components can be used singly or in combination.

[ (B) component ]

(B) The component (b) is a component for imparting strength to a cured product obtained by curing the present composition, and is a three-dimensional network organopolysiloxane resin represented by the following average unit formula (1).

(R² ₃SiO_1/2)_a(R¹R² ₂SiO_1/2)_b(R¹R²SiO)_c(R² ₂SiO)_d(R¹SiO_3/2)_e(R²SiO_3/2)_f(SiO₂)_g(1)

In the formula, R¹Independently represents an alkenyl group, R²Independently represents a monovalent hydrocarbon group free of addition-reactive carbon-carbon double bonds, all R²At least 80 mol% of (a) is methyl, and a, b, c, d, e, f, g satisfy 1>a≥0、1>b≥0、1>c≥0、1>d≥0、1>e≥0、1>f is not less than 0 and 1>g is not less than 0, and b + c + e>0、e+f+g>0. And a + b + c + d + e + f + g is a number of 1.

The component (B) is a wax-like or solid at 23 ℃ and the term "wax-like" means a gel-like (raw rubber-like) material which shows little self-fluidity at 23 ℃ and is 10,000 pas or more, particularly 100,000 pas or more.

In the above average composition formula (1), R¹The alkenyl group represented is the same group as the alkenyl group exemplified as the component (a), and a vinyl group is preferable in terms of availability and price.

R²Examples of the monovalent hydrocarbon group not containing an addition-reactive carbon-carbon double bond include the same groups as exemplified as the hydrocarbon group bonded to a silicon atom other than the alkenyl group in the component (A), but all of R²At least 80 mol% of (A) are methyl groups, preferably all R²95 to 100 mol% of the total amount of the aromatic vinyl monomers are methyl groups.

Preferably: a is a number of 0 to 0.65, b is a number of 0 to 0.65, c is a number of 0 to 0.5, d is a number of 0 to 0.5, e is a number of 0 to 0.8, f is a number of 0 to 0.8, and g is a number of 0 to 0.6. B + c + e is preferably a number of 0.01 to 0.30, particularly preferably a number of 0.05 to 0.20, and e + f + g is preferably a number of 0.1 to 0.8, particularly preferably a number of 0.2 to 0.6.

(B) The organopolysiloxane resin of component (b) is preferably a compound represented by the following formula, for example.

(R² ₃SiO_1/2)_a(R¹R² ₂SiO_1/2)_b(SiO₂)_g

(R¹R² ₂SiO_1/2)_b(SiO₂)_g

(R¹R²SiO)_c(R² ₂SiO)_d(R²SiO_3/2)_f

(R¹R² ₂SiO_1/2)_b(R² ₂SiO)_d(R¹SiO_3/2)_e

(R¹R² ₂SiO_1/2)_b(R² ₂SiO)_d(R²SiO_3/2)_f

(R² ₃SiO_1/2)_a(R¹R² ₂SiO_1/2)_b(R² ₂SiO)_d(R²SiO_3/2)_f

(R² ₃SiO_1/2)_a(R¹R² ₂SiO_1/2)_b(R¹R²SiO)_c(R² ₂SiO)_d(R²SiO_3/2)_f

In the formula, R¹、R²A, b, c, d, e, f and g and R defined in the average unit formula (1)¹、R²A, b, c, d, e, f and g are the same.

Specific examples of the component (B) include compounds represented by the following average unit formula.

(Me₃SiO_1/2)_0.4(ViMe₂SiO_1/2)_0.1(SiO₂)_0.5、

(ViMeSiO)_0.2(Me₂SiO)_0.35(MeSiO_3/2)_0.45、

(ViMe₂SiO_1/2)_0.2(Me₂SiO)_0.25(MeSiO_3/2)_0.55

(B) The components can be used singly or in combination.

The amount of the component (B) to be incorporated is 3 to 50 parts by mass, preferably 3 to 30 parts by mass, and more preferably 5 to 20 parts by mass, based on 100 parts by mass of the total of the components (A) and (B). When the blending amount of the component (B) is less than 3 parts by mass based on 100 parts by mass of the total of the component (A) and the component (B), it is difficult to obtain fluidity. When the blending amount exceeds 50 parts by mass, the viscosity of the composition becomes high, and the fluidity is lowered.

[ (C) ingredient ]

(C) The component (a) is an organohydrogenpolysiloxane having at least 2 hydrogen atoms (i.e., SiH groups) bonded to silicon atoms per molecule and having no addition-reactive carbon-carbon double bond, and functions as a crosslinking agent by undergoing a hydrosilylation reaction with the components (a) and (B).

(C) The organohydrogenpolysiloxane of component (A) has at least 2, preferably 3 to 300, and more preferably 4 to 150 SiH groups in one molecule on average.

(C) The bonding position of the hydrogen atom to the silicon atom in the organohydrogenpolysiloxane molecule of component (a) may be a molecular chain end, a non-molecular chain end, or both of the molecular chain end and the non-molecular chain end.

The content of the silicon atom-bonded hydrogen atom in the component (C) is preferably 0.001 to 5 mol, particularly preferably 0.01 to 2 mol, based on 100g of the component (C).

In the organohydrogenpolysiloxane molecule, the silicon atom-bonded hydrocarbon group other than the silicon atom-bonded hydrogen atom is not particularly limited, and examples thereof include an unsubstituted or substituted monovalent alkyl group having usually 1 to 10, preferably 1 to 6 carbon atoms. Specific examples thereof include the same groups as those exemplified as the silicon atom-bonded hydrocarbon group other than the silicon atom-bonded alkenyl group in the component (a).

(C) The molecular structure of the organohydrogenpolysiloxane of component (a) is not particularly limited, and examples thereof include linear, cyclic, branched, and three-dimensional network structures (resin structures), and linear or cyclic structures are preferable.

In order to further improve the workability of the composition or the optical and mechanical properties of the cured product, it is desirable that the viscosity of the component (C) at 25 ℃ be in a liquid state at 23 ℃ satisfying the following ranges: preferably, the viscosity of the aqueous dispersion satisfies 0.1 to 5,000 mPas, more preferably 0.5 to 1,000 mPas, and particularly preferably 2 to 500 mPas. When the viscosity is satisfied, the number of silicon atoms (or the degree of polymerization) in one molecule of organohydrogenpolysiloxane is usually 2 to 1,000, preferably 3 to 300, and more preferably 4 to 150.

Specific examples of the organohydrogenpolysiloxane of component (C) include 1,1,3, 3-tetramethyldisiloxane, 1,3,5, 7-tetramethylcyclotetrasiloxane, methylhydrogen-cyclopolysiloxane, dimethylsiloxane-methylhydrogen siloxane cyclic copolymer, methyltris (dimethylhydrosiloxy) silane, phenyltris (dimethylhydrosiloxy) silane, trimethylsiloxy-terminated methylhydrogen polysiloxane at both molecular chain terminals, trimethylsiloxy-terminated dimethylsiloxane-methylhydrogen siloxane copolymer at both molecular chain terminals, trimethylsiloxy-terminated dimethylsiloxane-methylhydrogen-siloxane copolymer at both molecular chain terminals, dimethylhydrosiloxy-terminated dimethylpolysiloxane at both molecular chain terminals, dimethylhydrosiloxy-terminated dimethylsiloxane-methylhydrogen-siloxane copolymer at both molecular chain terminals, and mixtures thereof, Dimethyl hydrogen siloxane oxygen alkyl end-capped dimethyl siloxane-methyl phenyl siloxane copolymer at two ends of a molecular chain, dimethyl hydrogen siloxane oxygen alkyl end-capped methyl phenyl polysiloxane at two ends of the molecular chain, and the formula is as follows: (CH)₃)₂HSiO_1/2Siloxane units represented by the formula: (CH)₃)₃SiO_1/2Siloxane units represented by the formula: SiO 2_4/2A copolymer of siloxane units represented by the formula: (CH)₃)₂HSiO_1/2Siloxane units represented by the formula: SiO 2_4/2Copolymers composed of the siloxane units, mixtures composed of two or more of these organopolysiloxanes, and the like.

(C) The organohydrogenpolysiloxane of component (b) is preferably a compound represented by the following formula, for example.

Me₃SiO(MeHSiO)_iSiMe₃

Me₃SiO(MeHSiO)_i(Me₂SiO)_jSiMe₃

In the formula, i and j are integers of 2 to 100, preferably 2 to 50.

Specific examples of the component (C) include organohydrogenpolysiloxanes represented by the following formulae.

Me₃SiO(MeHSiO)₃₈SiMe₃

(C) The organohydrogenpolysiloxane of component (a) may be used alone or in combination of two or more.

The amount of the component (C) is such that the amount of hydrogen atoms bonded to silicon atoms is 0.4 to 4.0 mol based on 1 mol of alkenyl groups in the components (A) and (B), and preferably 0.6 to 3.0 mol based on 1 mol of alkenyl groups in the components (A) and (B).

[ (D) component ]

The platinum group metal-based hydrosilylation catalyst as the component (D) is not particularly limited as long as it promotes the hydrosilylation reaction between the alkenyl groups in the components (a) and (B) and the SiH groups in the component (C), and specific examples thereof include platinum group metals such as platinum, palladium, rhodium, etc.; platinum compounds such as chloroplatinic acid, alcohol-modified chloroplatinic acid, and complexes of chloroplatinic acid with olefins, vinylsiloxanes, and acetylene compounds; platinum group metal compounds such as tetrakis (triphenylphosphine) palladium and tris (triphenylphosphine) rhodium chloride, platinum group compounds are preferred, and a complex of chloroplatinic acid and vinylsiloxane is particularly preferred.

(D) The components can be used singly or in combination.

(D) The amount of the component (C) to be blended may be an effective amount as a hydrosilylation catalyst, and is in the range of 0.1 to 1000ppm, preferably 1 to 500ppm, in terms of the mass of the platinum group metal, based on the total mass of the component (A), the component (B) and the component (C). When the amount of the catalyst is within this range, the reaction rate of the addition reaction is appropriate, and a cured product having high strength can be obtained.

[ (E) ingredient ]

(E) The component (A) is titanium dioxide powder whose surface is treated with siloxane, and is a component for imparting light reflection properties to the present composition.

When the surface of the titanium dioxide powder is not treated with siloxane, bubbles are generated during curing of the addition-curable silicone composition due to moisture contained in the powder, and sufficient performance as a light-reflecting material cannot be exhibited. In order to prevent foaming, there is a method of mixing silicone under heating and reduced pressure, but this step is not preferable because fluidity is lowered.

The crystal form of titanium dioxide can be classified into anatase, rutile, and brookite, but rutile type, which is most stable in thermal migration, is preferably used.

(E) The particle size of the component (A) is not particularly limited, but generally titanium dioxide powder having an average particle size in the range of 0.1 to 200 μm is commercially available in many cases, and the handling thereof is easy, and titanium dioxide powder having an average particle size in the range of 0.1 to 100 μm is more preferable. When the average particle diameter of the component (E) is in the range of 0.1 to 200 μm, the addition-curing silicone composition of the present invention is likely to have good fluidity, and the surface of the obtained cured product is less likely to be roughened, so that the light reflection performance is effectively improved.

As such (E) component, commercially available products can be used, and specific examples thereof include TIPAQUE PF-691 and TIPAQUE CR-63 manufactured by ISHIHARA SANGYOKAISHA, LTD.

(E) The components can be used singly or in combination.

The amount of component (E) is 20 to 200 parts by mass per 100 parts by mass of the total of components (A) and (B). Preferably 30 to 150 parts by mass, and more preferably 40 to 100 parts by mass. If the amount of the component (E) is less than 20 parts by mass based on 100 parts by mass of the total of the components (a) and (B), the light-reflecting properties of the cured product will be poor, and if it exceeds 200 parts by mass, it will be difficult to obtain fluidity.

[ (F) ingredient ]

(F) The component (B) is a component for imparting fluidity to the addition-curable silicone composition of the present invention by coexisting with the component (B), and is a compound represented by the following formula (2).

[ chemical formula 3]

In the formula, R³Independently is alkoxy, R⁴Is alkoxy or alkyl, n is 0 or 1, preferably 1. m is an integer of 1 to 10, preferably 2 to 9, and more preferably 3 to 8.

R in the formula (2)³For example, the alkoxy group is independently C1-C6. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a cyclopentyloxy group, and a cyclohexyloxy group, and a methoxy group and an ethoxy group are preferable, and a methoxy group is more preferable.

R in the formula (2)⁴Is alkoxy or alkyl, as alkoxy, with R being illustrated³The alkoxy groups exemplified in (1) are the same groups. Examples of the alkyl group include the same groups as those exemplified for the component (a).

Specific examples of the component (F) include the following compounds, but are not limited thereto.

[ chemical formula 4]

(F) The components can be used singly or in combination.

The amount of component (F) is 0.1 to 10 parts by mass, preferably 0.5 to 5.0 parts by mass, based on 100 parts by mass of the total of the components (A) and (B). If the amount of component (F) is too small, the fluidity is reduced, and if the amount of component (F) is too large, the durability of the resulting cured product is reduced.

< other ingredients >

The addition-curable silicone composition of the present invention may contain components such as an organic peroxide, an antioxidant, an adhesion improver, and a reaction inhibitor, depending on the purpose.

Examples of the organic peroxide include benzoyl peroxide, tert-butyl peroxybenzoate, o-methylbenzoyl peroxide, p-methylbenzoyl peroxide, dicumyl peroxide, 1-bis (tert-butylperoxy) -3,3, 3-trimethylcyclohexane, and bis (4-methylbenzoylperoxy) hexamethylene dicarbonate.

The amount of the organic peroxide to be added is preferably 0.01 to 5 parts by mass, particularly preferably 0.05 to 3 parts by mass, based on 100 parts by mass of the total of the components (A) to (F). Within such a range, further improvement in resin strength can be achieved. These organic peroxides may be used singly or in combination of two or more.

Examples of the antioxidant include hindered amines and hindered phenol compounds, and the amount of the antioxidant added is preferably 500 to 3,000ppm based on the total mass of the components (A) to (F).

From the viewpoint of imparting self-adhesiveness to the composition of the present invention of the addition reaction curing type, an organic silicon compound such as silane or siloxane, a non-silicone organic compound, or the like containing a functional group imparting adhesiveness is used as the adhesiveness-improving agent.

Specific examples of the functional group for imparting adhesiveness include an alkenyl group such as a vinyl group or an allyl group bonded to a silicon atom, or a hydrogen atom; an epoxy group (e.g., γ -glycidoxypropyl group, β - (3, 4-epoxycyclohexyl) ethyl group, etc.), an acryloxy group (e.g., γ -acryloxypropyl group, etc.), or a methacryloxy group (e.g., γ -methacryloxypropyl group, etc.) bonded to a silicon atom via a carbon atom; an alkoxysilyl group (for example, an alkoxysilyl group such as a trimethoxysilyl group, triethoxysilyl group, or methyldimethoxysilyl group bonded to a silicon atom via an alkenyl group which may have 1 to 2 ester structures, urethane structures, or ether structures).

Examples of the organic silicon compound having a functional group for imparting adhesiveness include a silane coupling agent, a siloxane having an alkoxysilyl group and an organic functional group, and a compound obtained by introducing an alkoxysilyl group into an organic compound having a reactive organic group.

Examples of the non-silicone organic compound include allyl organo-acid, epoxy ring-opening catalysts, organotitanium compounds, organozirconium compounds, and organoaluminum compounds.

Examples of the reaction inhibitor include phosphorus-containing compounds such as triphenylphosphine; nitrogen-containing compounds such as tributylamine, tetramethylethylenediamine and benzotriazole; a sulfur-containing compound; acetylene compounds; a hydroperoxide compound; a maleic acid derivative; known compounds having a curing-inhibiting effect on the hydrosilylation catalyst of the component (D) include 1-ethynylcyclohexanol, 3, 5-dimethyl-1-hexyn-3-ol, ethynylmethyldecylcarbinol, 1,3,5, 7-tetramethyl-1, 3,5, 7-tetravinylcyclotetrasiloxane, and the like.

Since the degree of the curing inhibition effect by the reaction inhibitor varies depending on the chemical structure of the reaction inhibitor, it is desirable to adjust the blending amount of the reaction inhibitor to an optimum amount for each reaction inhibitor used. Preferably, the amount of the component (A) is 0.001 to 5 parts by mass based on 30 parts by mass of the total of the components (A), (B) and (C). If the amount is 0.001 parts by mass or more, the long-term storage stability of the composition at room temperature can be sufficiently obtained. If the blending amount is 5 parts by mass or less, there is no fear that the curing of the composition is inhibited.

In addition, for the purpose of enhancing the reinforcing property, for example, an inorganic filler such as fine powder silica, crystalline silica, hollow filler, or silsesquioxane, a filler obtained by hydrophobizing the surface of the filler with an organic silicon compound such as an organoalkoxysilane compound, an organochlorosilane compound, an organoazane compound, or a low-molecular-weight siloxane compound, or the like may be blended in the addition-curable silicone composition of the present invention; silicone rubber powder, silicone resin powder, and the like.

As fine powder silicaPreferably, the specific surface area (BET method) is 50m²A fine powder of silica having a specific surface area of 50 to 400m is more preferable²A fine powder of silica having a specific surface area of 100 to 300m is particularly preferable²A fine powder of silica per gram. If the specific surface area is 50m²At least g, sufficient reinforcing properties can be imparted to the cured product.

As such fine powder silica, known fine powder silica conventionally used as a reinforcing filler for silicone rubber can be used, and examples thereof include fumed silica (dry silica), precipitated silica (wet silica), and the like. The fine powder silica may be used as it is, but in order to impart good fluidity to the composition, it is preferable to use fine powder silica treated with an organic silicon compound such as methylchlorosilanes such as trimethylchlorosilane, dimethyldichlorosilane and methyltrichlorosilane, dimethylpolysiloxane, hexamethyldisilazane, divinyltetramethyldisilazane and hexaorganodisilazane such as dimethyltetravinyldisilazane. One kind of such reinforcing silica may be used alone, or two or more kinds may be used simultaneously.

The addition-curable silicone composition of the present invention can be prepared by mixing components (a) to (F) and, if necessary, other components, and for example, a part containing component (a), component (B), and component (D) and a part containing component (C) can be prepared separately and then the two parts can be mixed and used. Further, a portion containing the component (a), the component (B), and the component (C) and a portion containing the component (D) may be mixed.

Further, since the component (B) is wax-like or solid at 23 ℃ and is soluble in other components, a solution obtained by dissolving the component (B) in a solvent may be mixed with the component (a), the solvent may be removed by distillation under reduced pressure or the like to prepare a mixture of the component (a) and the component (B), and then the mixture may be mixed with other components.

The addition-curable silicone composition of the present invention is liquid before curing and has high fluidity. The fluidity here means how much the fluid flows on a smooth plate having an inclination, and is different from the rotational viscosity because the relationship with the rotational viscosity is not necessarily the case.

0.05g of the addition-curable silicone composition of the present invention is placed on an aluminum plate having an inclination angle of 45 ° with respect to the horizontal, and the length (fluidity) after standing at 25 ℃ for 1 hour is preferably 30mm or more, more preferably 40mm or more. When the fluidity is 30mm or more, the coated surface of the composition is easily spread and the workability is good. The length here means the maximum straight-line distance from one end of the composition to the other end.

[ Silicone cured product for light-reflecting Material ]

By curing the addition-curable silicone composition of the present invention, a white silicone cured product for a light-reflecting material can be obtained. Since the addition-curable silicone composition of the present invention has good fluidity, the light-reflecting material can be applied as a thin film by applying the composition by dispensing and then curing the composition after self-leveling (self-leveling). The curing conditions of the addition-curable silicone composition of the present invention are not particularly limited, and are usually 80 to 200 ℃, preferably 100 to 180 ℃,1 minute to 24 hours, and more preferably 5 minutes to 5 hours.

Since the addition-curable silicone composition of the present invention is used by being applied as a film, the film must have a good reflectance of visible light (wavelength: 430 to 800 nm). Specifically, when the thickness of the cured product is 0.3mm or less, the visible light reflectance is preferably 90% or more (i.e., 90 to 100%). The visible light reflectance is more preferably 95% or more (i.e., 95 to 100%). If the reflectance is 90% or more, when the light extraction efficiency is higher when the light extraction efficiency is applied to a lead frame having low light reflectance such as gold plating or aluminum, sufficient luminance of the optical semiconductor element can be easily ensured. The light reflectance in the present specification is a numerical value measured by a spectrophotometer equipped with an integrating sphere.

[ light-reflecting Material ]

The light-reflecting material comprising the cured silicone material for a light-reflecting material of the present invention can be used, for example, in an optical semiconductor device such as an LED, and is particularly suitable as a light-reflecting coating material for a lead frame or the like for a white LED.

[ optical semiconductor device ]

Further, the present invention provides an optical semiconductor device having the above-mentioned light reflecting material.

As described above, the addition-curable silicone composition of the present invention gives a silicone cured product for a light-reflecting material that is excellent in light-reflecting performance even in a thin film. Therefore, the optical semiconductor device such as a white LED using the light reflective material of the present invention can maintain high light extraction efficiency for a long time.

An embodiment of an optical semiconductor device according to the present invention will be described with reference to fig. 1. As shown in fig. 1, the white coating material 6 is dropped on the lead electrode 2 provided in the optical semiconductor device 7, and the white coating material wets and spreads so as to cover the lead electrode 2 and the like, and after curing, reflects light emitted from the light emitting element 1 instead of the lead electrode 2, thereby improving light extraction efficiency. The light-emitting element 1 bonded to the lead electrode 2 with the die bonding material 3 is connected to the lead electrode 2 with a gold wire 4. Further, a reflector (reflector) is formed around the optical semiconductor device 7 by the light reflecting resin 5.