Silicone resin composition, cured product of the silicone resin composition, and optoelectronic semiconductor device.

Abstract

To provide an addition reaction-curable silicone resin cured product that increases the glass transition temperature Tg and is excellent in high gas permeability resistance. [Solution] (A) A branched organopolysiloxane represented by the following average formula, having 10% or more of aryl groups bonded to silicon atoms based on the total number of substituents bonded to silicon atoms, and having at least two silicon-bonded alkenyl groups in one molecule, (SiO 4 / 2 ) a (R 1 SiO 3 / 2 ) b (R 2 SiO 3 / 2 ) c (R 2 R 3 SiO 2 / 2 ) d (B) A hydrosilyl group-containing organosilicon compound having two or more SiH groups in one molecule: in an amount such that the ratio of the number of hydrosilyl groups in component (B) to the number of alkenyl groups in component (A) is 0.1 to 4.0, and (C) a platinum group metal catalyst: in a catalytic amount A silicone resin composition comprising the above components.

Description

[Technical Field]

[0001] The present invention relates to a silicone resin composition that provides a cured product with high gas permeability resistance, and to an optoelectronic device having the cured product. [Background technology]

[0002] Organopolysiloxanes possess excellent heat resistance, cold resistance, electrical insulation, light resistance, weather resistance, light transmittance, gas permeability, and chemical stability, making them superior materials used in a wide variety of fields, from electrical and electronics to transportation equipment, office supplies, cosmetics, and medical applications. Among these, addition-curing silicone resin compositions (hereinafter referred to as silicone resin compositions), which exhibit excellent transparency, are used as materials for optoelectronic semiconductors such as LEDs.

[0003] In recent years, optoelectronic devices have been used as LED lighting for outdoor lighting or automotive applications. Generally, resins with high gas or moisture permeability, such as silicone resin, are used as encapsulants in such optoelectronic devices. Therefore, in harsh environments such as outdoors, the silver plating layer used as the electrode or reflective layer of the optoelectronic device corrodes due to sulfur-based gases or moisture, leading to a significant decrease in brightness.

[0004] As a countermeasure, the introduction of aromatic substituents such as phenyl groups to increase refractive index and improve gas permeability resistance has been investigated (Patent Document 1). However, there is a limit to the proportion of phenyl groups that can be contained in one molecule of silicone due to steric hindrance and other factors. In addition, when phenyl silicone is used, the glass transition temperature Tg is around 50°C, and the elastic modulus decreases sharply around this temperature, which is problematic because it significantly reduces gas permeability resistance in the medium to high temperature range.

[0005] Furthermore, known corrosion inhibitors to prevent metal corrosion include, for example, compounds of nitrogen-containing aromatic hydrocarbons such as benzotriazole and 5-methylbenzimidazole, or metal complexes such as zinc, and attempts to add these corrosion inhibitors are also being considered. However, there is a problem that the heat resistance of the resin is greatly reduced due to the discoloration of the corrosion inhibitor and metal ligand (Patent Document 2).

[0006] Furthermore, resin compositions using polyorganosiloxanes containing thiazole or triazine compounds in the siloxane skeleton have also been developed. However, depending on the curing method of the silicone resin composition, there is a risk of inhibiting curing, and in addition-curing type resin compositions, they act on platinum and other elements to become catalyst poisons, making them difficult to use (Patent Document 3). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2014-185293 [Patent Document 2] Japanese Patent Publication No. 2012-056251 [Patent Document 3] Japanese Patent Publication No. 2012-251058 [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention has been made in view of the above problems, and aims to provide an addition reaction curing type silicone resin cured product that has an increased glass transition temperature Tg and excellent gas permeability resistance. [Means for solving the problem]

[0009] The inventors of the present invention have conducted diligent research to solve the above problems and have found that RSiO has an alkenyl group and an aryl group. 3 / 2 Unit (T units) and / or R2SiO 2 / 2It has been found that an addition reaction-curable silicone resin composition comprising a branched organopolysiloxane having a specific proportion of D units (D units) can increase the glass transition temperature Tg of a cured product and provide a cured silicone resin product excellent in gas permeability resistance, which has led to the completion of the present invention.

[0010] That is, the present invention provides: (A) a branched organopolysiloxane represented by the following average formula, having 10% or more aryl groups bonded to silicon atoms based on the total number of substituents bonded to silicon atoms, and having at least two silicon-bonded alkenyl groups per molecule, (SiO 4 / 2 ) a (R 1 SiO 3 / 2 ) b (R 2 SiO 3 / 2 ) c (R 2 R 3 SiO 2 / 2 ) d (1) (In the above formula, R 1 are each independently a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms other than an alkenyl group, or an aryl group having 6 to 10 carbon atoms; R 2 are each independently an alkenyl group having 2 to 10 carbon atoms; R 3 are each independently a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms other than an alkenyl group, or an aryl group having 6 to 10 carbon atoms; a, b, c and d are each numbers satisfying a≧0, b>0, c≧0, and d≧0, with the proviso that c+d>0 and a+b+c+d=1) (B) a hydrosilyl group-containing organosilicon compound having two or more SiH groups per molecule, in an amount such that the ratio of the number of hydrosilyl groups in component (B) to the number of alkenyl groups in component (A) is 0.1 to 4.0, and (C) a platinum group metal catalyst, in a catalytic amount A silicone resin composition comprising the above components is provided.

[0011] The silicone resin composition of the present invention further comprises at least one of the components shown in [1] to [3] below. [1] The silicone resin composition in formula (1) above, wherein a is a number from 0 to 0.6, b is a number from 0.1 to 0.9, c is a number from 0 to 0.5, d is a number from 0 to 0.5, c+d>0, and a+b+c+d=1. [2] The silicone resin composition wherein component (B) is an organosilicon compound selected from organohydrogen(poly)siloxane, organo(poly)sylphenylene, and organo(poly)sylphenylenesiloxane, having 2 to 200 silicon atoms in one molecule and one or more silicon atom-bonded aryl groups in one molecule. [3] The silicone resin composition wherein component (A) has a weight-average molecular weight of 1,000 to 50,000 with polystyrene as the standard substance determined by gel permeation chromatography (GPC).

[0012] The present invention also provides a cured product of the above-mentioned silicone resin composition. The cured product further comprises at least one of the components shown in [1] and [2] below. [1] The cured product characterized in that the type D hardness of the cured product, measured by the method described in JIS K 6253-3, is in the range of 30 to 90. [2] The cured product characterized in that the refractive index of the cured product at a wavelength of 589 nm, as measured by the method described in JIS K 0062, is in the range of 1.45 to 1.60. Furthermore, the present invention provides an optical semiconductor device comprising the cured product and the optical semiconductor element.

[0013] The cured product obtained by curing the silicone resin composition of the present invention preferably has a Type D hardness value in the range of 30 to 90, as measured by the method described in JIS K 6253-3. A cured product having such hardness has excellent resin strength and can be highly reliable.

[0014] The cured product obtained by curing the silicone resin composition of the present invention preferably has a refractive index at a wavelength of 589 nm measured by the method described in JIS K 0062, which is in the range of 1.45 to 1.60. A silicone resin composition that yields a cured product having such direct light transmittance can be used particularly suitably for optical applications such as LED encapsulants. [Effects of the Invention]

[0015] The present invention relates to an addition-curing type silicone resin composition containing a branched-chain organopolysiloxane having a specific structure, which can provide a cured product with excellent gas permeability resistance and reliability. The silicone resin composition can provide a cured product with excellent mechanical properties, transparency, and sulfurization resistance. Furthermore, the addition-curing type silicone resin composition of the present invention is suitable for lens materials, protective coatings, and molding agents for light-emitting semiconductor devices, and a semiconductor device equipped with a cured product of the composition and a semiconductor element can provide a light-emitting semiconductor device that ensures long-term reliability under high humidity conditions and has good moisture resistance and long-term color rendering. [Modes for carrying out the invention]

[0016] The present invention will be described in detail below, but the present invention is not limited to these descriptions. [(A) Branched organopolysiloxanes] The silicone resin composition of the present invention is characterized by containing a branched-chain organopolysiloxane of a specific structure, thereby providing a cured product that exhibits high gas permeability resistance and is stable under high temperature and high humidity conditions. More specifically, component (A) has aryl groups bonded to silicon atoms in an amount of 10% or more relative to the total number of substituents bonded to silicon atoms. A silicone resin composition containing such a branched-chain organopolysiloxane provides a cured product with superior gas permeability resistance. More specifically, component (A) of the present invention is a branched-chain organopolysiloxane represented by the following average composition formula (1). (SiO 4 / 2 ) a (R 1 SiO 3 / 2 ) b (R2 SiO 3 / 2 ) c (R 2 R 3 SiO 2 / 2 ) d (1) (In the above formula, R 1 R is independently a hydroxyl group, a carbon 1-10 alkoxy group, a carbon 1-10 substituted or unsubstituted alkyl group other than an alkenyl group, or a carbon 6-10 aryl group. 2 R is an alkenyl group having 2 to 10 carbon atoms. 3 (A, B, C, and D are independently hydroxyl groups, C1-C10 alkoxy groups, C1-C10 substituted or unsubstituted alkyl groups other than alkenyl groups, or C6-C10 aryl groups.)

[0017] The component (A) is characterized in that it has 10% or more aryl groups bonded to silicon atoms relative to the total number of substituents bonded to silicon atoms. More preferably, it has 10 to 90% aryl groups bonded to silicon atoms relative to the total number of substituents bonded to silicon atoms. Even more preferably, it is 35% to 90%, and the lower limit is even more preferably 50% or more. Having aryl groups above the lower limit provides the effect of high gas permeability resistance. If the upper limit is exceeded, there will be too many aromatic groups, resulting in a rigid structure, which may make the resulting resin composition brittle.

[0018] The above component (A) is an organopolysiloxane with a resin structure. The organopolysiloxane is characterized by having a specific proportion of T units and / or D units having alkenyl groups and aryl groups. That is, R 1 SiO 3 / 2 The unit (hereinafter referred to as T unit) is mandatory, R 2 R 3 SiO 2 / 2 Units (hereinafter referred to as D units) and R 2 SiO 3 / 2It contains at least one unit (hereinafter referred to as T unit) and any SiO 4 / 2 It has units (hereinafter referred to as Q units). In the above average composition formula (1), a, b, c, and d are numbers that satisfy a≧0, b>0, c≧0, and d≧0, respectively, provided that c+d>0 and a+b+c+d=1. SiO when the total number of siloxane units is 1. 4 / 2 The number ratio of units, a, is preferably 0 to 0.6, and more preferably 0 to 0.5. R when the total number of siloxane units is 1. 1 SiO 3 / 2 The ratio of the number of units, b, is preferably 0.1 to 0.9, and more preferably 0.3 to 0.8. Furthermore, it is preferable that a + b is a number of 0.5 or greater. R when the total number of siloxane units is 1. 2 SiO 3 / 2 c represents the ratio of units, and R is defined as the total number of siloxane units being 1. 2 R 3 SiO 2 / 2 The ratio of the number of units, d, is independent of each other, preferably 0 to 0.5, more preferably 0 to 0.3. c+d is a number greater than 1, preferably 0.01 to 0.7, more preferably 0.1 to 0.5. Component (A) of the present invention is preferably R3SiO 1 / 2 It does not have a unit (hereinafter referred to as the M unit, where R is a monovalent hydrocarbon group), and in particular, it does not have an M unit having an alkenyl group.

[0019] In the above, R 1 These are independently a hydroxyl group, a carbon-1 to carbon-10 alkoxy group, a carbon-1 to carbon-10 substituted or unsubstituted alkyl group, or a carbon-6 to carbon-10 aryl group, R 2 R is an alkenyl group having 2 to 10 carbon atoms. 3 R is independently a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms. 1 and R 3More specifically, these include lower alkyl groups such as methyl, ethyl, propyl, and butyl groups; cycloalkyl groups such as cyclohexyl groups; aryl groups such as phenyl, tolyl, and xylyl groups; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl groups; and groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine, bromine, or chlorine, or cyano groups, such as chloromethyl, cyanoethyl, and 3,3,3-trifluoropropyl groups. Among these, methyl and phenyl groups are preferred. Methoxy and ethoxy groups are preferred as alkoxy groups. 2 Examples of alkenyl groups include vinyl, allyl, propenyl, isopropenyl, butenyl, hexenyl, cyclohexenyl, and octenyl groups. Among these, vinyl groups are preferred.

[0020] Component (A) has at least two silicon atom-bonded alkenyl groups in one molecule. The amount of alkenyl groups contained in component (A) is preferably 0.01 to 0.5 mol / 100g, more preferably 0.05 to 0.3 mol / 100g, and even more preferably 0.10 to 0.25 mol / 100g. If the amount of alkenyl groups bonded to silicon atoms is less than 0.01 mol / 100g, there may be few crosslinking sites and the composition may not solidify. If it exceeds 0.5 mol / 100g, the crosslinking density will increase and toughness may be lost.

[0021] In component (A), the amount of hydroxyl groups bonded to silicon atoms is preferably 0.001 to 1.0 mol / 100g, more preferably 0.005 to 0.8 mol / 100g, and even more preferably 0.008 to 0.6 mol / 100g.

[0022] In component (A), the amount of alkoxy groups bonded to silicon atoms is preferably 1.0 mol / 100g or less, more preferably 0.8 mol / 100g or less, and even more preferably 0.5 mol / 100g or less. There is no particular lower limit to the amount of alkoxy groups; the less the better. If the amount of alkoxy groups exceeds 1.0 mol / 100g, alcohol gas will be generated as a by-product during curing, and voids may remain in the cured product. Note that the amount of hydroxyl groups and alkoxy groups bonded to silicon atoms in this invention is 1 H-NMR and 29 This refers to values ​​measured by Si-NMR.

[0023] The branched-chain organopolysiloxane described above preferably has a weight-average molecular weight (Mw) of 1,000 to 50,000, more preferably 1,000 to 20,000, and even more preferably 2,000 to 15,000. If the molecular weight is below the lower limit, the composition may become brittle, and if the molecular weight is above the upper limit, the viscosity of the composition may become high and it may not flow. In this invention, the weight-average molecular weight (Mw) is the weight-average molecular weight with polystyrene as the standard substance, measured by gel permeation chromatography (GPC), and can be measured under the following conditions. [Measurement conditions] Developing solvent: Tetrahydrofuran (THF) Flow rate: 0.6mL / min Detector: Differential refractive index detector (RI) Column: TSK Guardcolomn SuperH-L TSKgel SuperH4000(6.0mmI.D.×15cm×1) TSKgel SuperH3000(6.0mmI.D.×15cm×1) TSKgel SuperH2000(6.0mmI.D.×15cm×2) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 20 μL (THF solution with a concentration of 0.5% by mass)

[0024] SiO4 / 2 Examples of materials used to obtain units (Q units) include, but are not limited to, sodium silicate, tetraalkoxysilane, or their condensation reaction products.

[0025] R 1 SiO 3 / 2 Units and R 2 SiO 3 / 2 Examples of materials for obtaining units (T units) include, but are not limited to, organosilicon compounds such as organotrichlorosilanes and organotrialokkoxysilanes represented by the following structural formulas, or condensation reaction products thereof. [ka] (In the above formula, Me represents a methyl group.)

[0026] R 2 R 3 SiO 2 / 2 Examples of materials for obtaining units (D units) include organosilicon compounds such as diorganodichlorosilanes and diorganodialkoxysilanes, represented by the following structural formulas, but are not limited to these. [ka]

[0027] [(B) Hydrosilyl group-containing organosilicon compounds] Component (B) is a hydrosilyl group-containing organosilicon compound having two or more hydrogen atoms bonded to silicon atoms (hereinafter referred to as hydrosilyl groups) in one molecule, and reacts with component (A) to act as a crosslinking agent.

[0028] Component (B) is preferably an organosilicon compound selected from organohydrogen(poly)siloxane, organo(poly)sylphenylene, and organo(poly)sylphenylenesiloxane, having two or more hydrosilyl groups in one molecule. Organosilicon compounds having 2 to 200 silicon atoms and one or more silicon-bonded aryl groups in one molecule are preferred. The above organohydrogen(poly)siloxane is, for example, represented by the following average composition formula (2). The organo(poly)sylphenylene is, for example, represented by the following average composition formula (3). Alternatively, it may be an organohydrogen(poly)sylphenylenesiloxane having a siloxane structure represented by the average composition formula (2) and a sylphenylene structure represented by the following average composition formula (3) in its molecule. R 4 h H i SiO (4-h-i) / 2 (2) R 4 h H i SiPh (4-h-i) / 2 (3) In the formula, R 4 Independently, each of the three elements is an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and h and i are positive numbers satisfying 0.7 ≤ h ≤ 2.1, 0.001 ≤ i ≤ 1.0, and 0.8 ≤ h + i ≤ 3.0, preferably 1.0 ≤ h ≤ 2.0, 0.01 ≤ i ≤ 1.0, and 1.5 ≤ h + i ≤ 3.0. In the above formula (3), Ph is a divalent benzene ring (phenylene), more preferably a p-phenylene group.

[0029] The above R 4 Examples include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, cyclopentyl, and cyclohexyl groups; aryl groups such as phenyl, tolyl, xylyl, benzyl, phenylethyl, and phenylpropyl groups; and halogenated hydrocarbon groups such as trifluoropropyl and chloropropyl groups, in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms such as fluorine, bromine, and chlorine. Among these, alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, and propyl groups, and phenyl groups are preferred.

[0030] Component (B) preferably has one or more silicon-bonded aryl groups per molecule, and more preferably has 1 to 100 silicon-bonded aryl groups per molecule. More preferably has 1 to 70 silicon-bonded aryl groups.

[0031] Component (B) preferably has at least 2 to 200 hydrosilyl groups in one molecule. The lower limit is more preferably 3 or more. The upper limit is more preferably 100 or less, and even more preferably 80 or less.

[0032] The molecular structure of component (B) is not particularly limited, and any molecular structure such as linear, cyclic, branched, or three-dimensional network (resin-like) can be used as component (B). If component (B) has a linear structure, the hydrosilyl group may be bonded to the silicon atom only at either the molecular chain end or the molecular chain side chain, or to the silicon atom at both.

[0033] One embodiment of component (B) is an organohydrogen (poly)siloxane in which the number of silicon atoms (or degree of polymerization) in one molecule is 2 to 200, preferably 3 to 100, more preferably 3 to 70, even more preferably 3 to 50, and even more preferably 3 to 30. An organohydrogen (poly)siloxane that is liquid or solid at room temperature (25°C) is preferred. (B) Another embodiment of component is a compound having a sylphenylene structure and containing two or more hydrogen atoms bonded to silicon atoms in one molecule. Preferably, it is an organo(poly)sylphenylene having hydrosilyl groups at both ends of the molecular chain and a sylphenylene structure, with the number of silicon atoms (or degree of polymerization) in one molecule being 2 to 50, more preferably 2 to 30, and even more preferably 2. Furthermore, as described above, component (B) may also be an organohydrogen (poly)sylphenylenesiloxane having a sylphenylene structure. The number of silicon atoms (or degree of polymerization) in one molecule is usually 2 to 200, preferably 3 to 100, more preferably 3 to 70, even more preferably 3 to 50, and still more preferably 3 to 30, similar to organohydrogen (poly)siloxane.

[0034] Examples of organohydrogenpolysiloxanes represented by the above average composition formula (2) include tris(hydrogendimethylsiloxy)phenylsilane, methylhydrogensiloxane-diphenylsiloxane copolymer with trimethylsiloxy group blockade at both ends, methylhydrogensiloxane-diphenylsiloxane-dimethylsiloxane copolymer with trimethylsiloxy group blockade at both ends, methylhydrogensiloxane-methylphenylsiloxane-dimethylsiloxane copolymer with dimethylhydrogensiloxy group blockade at both ends, methylhydrogensiloxane-dimethylsiloxane-diphenylsiloxane copolymer with dimethylhydrogensiloxy group blockade at both ends, methylhydrogensiloxane-dimethylsiloxane-methylphenylsiloxane copolymer, (CH3)2HSiO 1 / 2 Units and SiO 4 / 2 Units and (C6H5)3SiO 1 / 2 Examples include copolymers composed of units.

[0035] (B) More specifically, components include hydrosilyl group-containing organosilicon compounds shown in the following structure, but are not limited to those shown below. [ka] [ka] [ka] (p, q, and r are all non-negative integers such that p+q+r is between 3 and 500.)

[0036] In the silicone resin composition of the present invention, the amount of component (B) is such that the ratio of hydrosilyl groups in component (B) to the number of alkenyl groups bonded to silicon atoms in component (A) is 0.1 to 4.0, preferably 0.5 to 3.0, and more preferably 0.8 to 2.0. If the amount of component (B) is less than the above lower limit, the curing reaction of the silicone resin composition will not proceed, making it difficult to obtain a cured product. The resulting cured product will have too low a crosslinking density, resulting in insufficient mechanical strength and poor heat resistance. On the other hand, if the amount of component (B) is greater than the above upper limit, a large amount of unreacted hydrosilyl groups will remain in the cured product, causing changes in physical properties over time and a decrease in the heat resistance of the cured product. Furthermore, it can cause foaming due to dehydrogenation reactions in the cured product.

[0037] [(C) Platinum group metal catalyst] Component (C) is a catalyst that promotes the hydrosilylation reaction between component (A) and component (B). Any conventionally known platinum group metal catalyst can be used. Considering cost and other factors, platinum-based catalysts such as platinum, platinum black, and chloroplatinic acid are preferred. Examples include H2PtCl6·pH2O, K2PtCl6, KHPtCl6·pH2O, K2PtCl4, K2PtCl4·pH2O, PtO2·pH2O, PtCl4·pH2O, PtCl2, H2PtCl4·pH2O (where p is a positive integer), and complexes of these with hydrocarbons such as olefins, alcohols, or vinyl group-containing organopolysiloxanes, and photoactive complexes such as trimethyl(methylcyclopentadienyl)platinum. These catalysts can be used individually or in combination of two or more.

[0038] (C) The amount of catalyst added is a catalytic amount and is not particularly limited. It may be an effective amount to promote the hydrosilylation reaction between component (A) and component (B). Typically, it is in the range of 0.1 to 500 ppm, particularly preferably 0.5 to 100 ppm, as platinum group metals on a mass basis relative to the total amount of component (A) and component (B).

[0039] [(D) Solvent] Component (D) is a solvent for improving the fluidity of the resin composition. Any conventionally known organic solvent can be used. Examples include hydrocarbons such as hexane, heptane, benzene, toluene, and xylene; esters such as ethyl acetate, n-butyl acetate, and propylene glycol methyl ether acetate; ketones such as methyl ethyl ketone, methyl amyl ketone, cyclohexanone, cyclopentanone, and methyl isobutyl ketone; ethers such as diethyl ether, diisopropyl ether, methyl tert-butyl ether, and ethyl cyclopentyl methyl ether; and chlorinated solvents such as methylene chloride, chloroform, dichloroethane, and trichloroethylene. These solvents can be used individually or in combination of two or more. The amount of solvent should be adjusted as appropriate within a range that does not impair the effects of the present invention. Preferably, the amount is 50 parts by mass or less per 100 parts by mass of the total of components (A) and (B), and more preferably, it can be blended in an amount of 1 to 30 parts by mass as appropriate.

[0040] [Other additives] The silicone resin composition of the present invention may contain, in addition to the above components (A), (B), and (C), other additives as appropriate. Other additives include, for example, reinforcing inorganic fillers such as silica, glass fiber, and fumed silica; inorganic white pigments such as titanium dioxide, zinc oxide, zirconium oxide, calcium carbonate, magnesium oxide, aluminum hydroxide, barium carbonate, magnesium silicate, zinc sulfate, and barium sulfate; non-reinforcing inorganic fillers such as calcium silicate, carbon black, cerium fatty acid salts, barium fatty acid salts, cerium alkoxide, and barium alkoxide; silver (Ag), aluminum (Al), aluminum nitride (AlN), boron nitride (BN), silicon dioxide (silica: SiO2), aluminum oxide (alumina: Al2O3), iron oxide (Fe2O3), triiron tetroxide (Fe3O4), lead oxide (PbO2), tin oxide (SnO2), and cerium oxide (Ce2O2). 3、Fillers such as CeO2, calcium oxide (CaO), trimanganese tetroxide (Mn3O4), and barium oxide (BaO) are examples. The amount of additives can be adjusted as appropriate within a range that does not impair the effects of the present invention. The amount of additives can be appropriately blended in an amount of preferably 600 parts by mass or less, and more preferably 10 to 400 parts by mass, per 100 parts by mass of the total of components (A) and (B).

[0041] The silicone resin composition of the present invention can be cured after being applied to a predetermined substrate depending on the application. While sufficient curing occurs at room temperature (25°C), curing may be performed by heating if necessary. For example, curing can be performed at temperatures between 60 and 200°C.

[0042] The cured product comprising the composition of the present invention has a hardness of 30 to 90, preferably 35 to 85, and more preferably 40 to 80, as measured using a durometer type D hardness tester in accordance with JIS K 6253-3. If the hardness is less than 30, the strength is insufficient, and if it exceeds 90, although the strength is excellent, the resin becomes rigid, making it prone to cracking, delamination, and other reliability issues.

[0043] The cured product comprising the composition of the present invention has a refractive index of 1.45 to 1.60 at a wavelength of 589 nm, as measured by the method described in JIS K 0062, preferably 1.47 to 1.60, and more preferably 1.50 to 1.60. If the refractive index is less than 1.45, the anti-reflective effect is small, and if it is greater than 1.60, the anti-reflective effect is excellent, but the functionality as an optoelectronic device, such as light transmittance, is poor.

[0044] The silicone resin composition of the present invention can be used in a variety of applications, such as encapsulants, adhesives, electrical insulating materials, laminates, coatings, inks, paints, sealants, resists, composite materials, films, underfill materials, anti-reflective materials, light-diffusing materials, and light-reflective materials, but is not limited to these. Furthermore, the present invention provides an optoelectronic device in which a semiconductor element is encapsulated with a cured product of the silicone resin composition of the present invention described above. [Examples]

[0045] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto. Parts refer to parts by mass, and the viscosity of each component is the absolute viscosity at 25°C measured with a rotational viscometer as described in JIS K 7117-1:1999. The weight-average molecular weight is the value obtained by gel permeation chromatography using the method described above, with polystyrene as the standard substance.

[0046] The evaluation test methods used in the following examples and comparative examples are as follows. (1) Exterior The color, transparency, and presence or absence of voids of the cured product (1 mm thick) obtained by curing each silicone resin composition at 180°C for 4 hours were visually inspected. (2) Properties The fluidity of each silicone resin composition before curing was checked. 50g of the composition was added to a 100ml glass bottle, and the bottle was left standing at 25°C for 10 minutes with the bottle on its side. If the resin flowed out during this time, it was determined to be liquid. (3) Viscosity The viscosity of each silicone resin composition before curing at 25°C was measured by the method described in JIS K 7117-1:1999. (4) Refractive index The refractive index of each silicone resin composition before curing was measured at 25°C using an ATAGO RX-9000α digital refractometer, in accordance with the method described in JIS K 0062, at a wavelength of 589 nm. (5) Hardness (Type D) The hardness of the cured product (120 mm × 110 mm × 1 mm) obtained by curing each silicone resin composition at 180°C for 4 hours was measured using a durometer type D hardness tester in accordance with JIS K 6253-3. (6) Stress at fracture and flexural modulus The fracture stress and flexural modulus of cured products (120 mm × 110 mm × 1 mm) obtained by curing each silicone resin composition at 180°C for 4 hours were measured using a Shimadzu Autograph AG-IS in accordance with JIS K 7171:1994. (7) Adhesiveness 0.25g of each silicone resin composition, over an area of ​​180mm² 2 The copper plate has a base area of ​​45mm 2 The material was molded to create a test specimen for bonding, which was then cured at 180°C for 4 hours. The shear bonding strength of this test specimen was measured at 25°C and 150°C using a Bond Tester DAGE-SERIES-4000PXY (manufactured by DAGE). The bonding strength retention rate was calculated using the following formula. Adhesion retention rate (%) = (Adhesion strength at 150°C [MPa]) / (Adhesion strength at 25°C [MPa] [%]) × 100 (8) Heat resistance test Each silicone resin composition was cured at 180°C for 4 hours to obtain a cured product (120mm x 110mm x 1mm). The cured product was then left at 150°C for 100 hours, and the change in color was visually confirmed. (9) Measurement of water vapor transmission The water vapor permeability of cured products (120 mm × 110 mm × 1 mm) obtained by curing each silicone resin composition at 180°C for 4 hours was measured using a Lyssy L80-5000 (Systech Instruments) water vapor permeability meter, according to the cup method at 40°C as per JIS Z 0208:1976. Furthermore, a value close to the lower limit of the cup method, 0.1 g / m³, was used. 2 Water vapor transmission rates of less than / day were measured using the Mocon method according to JIS K 7129B:2019. (10) Sulfidation resistance 1cm 2 A silver-plated plate was sealed with a silicone resin composition to a thickness of 0.6 mm and cured at 180°C for 4 hours to obtain a sample. This sample was placed in a sealed container with 3 g of sulfur powder and left in an 80°C constant temperature bath for 50 hours. After that, the initial light reflectance of the silver-plated plate at 450 nm was measured using an X-rite8200 manufactured by SDG Corporation. The initial reflectance was 90% in all cases. The sulfurization resistance was calculated using the following formula and evaluated according to the following criteria. Sulfurization resistance (%) = ((Reflectance after sulfurization test [%]) / (Initial reflectance [%])) × 100 (Judgment criteria) ○: Sulfuration resistance of 90% or higher, △: Sulfuration resistance of 80% or higher and less than 90%, ×: Sulfuration resistance of less than 80% (11) Surface tackiness The presence or absence of dust adhesion on the surface of a cured product (120 mm × 110 mm × 1 mm) obtained by curing each silicone resin composition at 180° C. for 4 hours was visually confirmed. (12) Glass transition temperature The glass transition temperature of a cured product (120 mm × 110 mm × 1 mm) obtained by curing each silicone resin composition at 180° C. for 4 hours was measured using DMA-800 manufactured by TA Instruments.

[0047] [Synthesis Example 1] Synthesis of branched chain organopolysiloxane (A-1) 495.7 g (2.50 mol) of phenyltrimethoxysilane (KBM-103, manufactured by Shin-Etsu Chemical Co., Ltd.), 190.1 g (1.25 mol) of tetramethoxysilane (KBM-04, manufactured by Shin-Etsu Chemical Co., Ltd.), and 145.3 g (1.25 mol) of vinylmethyldimethoxysilane (KBM-1012, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed, 13.3 g of methanesulfonic acid, 123.9 g of pure water and 1000 g of xylene were added, and the mixture was stirred at 90° C. for 4 hours. Thereafter, 25.0 g of a 50 wt% aqueous potassium hydroxide solution was added, and the mixture was further stirred at 130° C. for 16 hours. Acetic acid was added to neutralize the solution, followed by washing with 10 wt% aqueous sodium sulfate solution. The organic layer was subjected to azeotropic dehydration at 120° C. for 1 hour, filtered through a 0.45 μm filter paper, and the solvent was removed by distillation under reduced pressure to prepare branched organopolysiloxane (A-1). The obtained branched organopolysiloxane (A-1) has an average structure of SiO 4 / 2 ) 0.25 (PhSiO 3 / 2 ) 0.50 ((CH2=CH―)MeSiO 2 / 2 ) 0.25 and has Q 0.25 T 0.5 D Vi 0.25represented by the formula, having Mw = 7700, having a hydroxyl group content bonded to silicon atoms of 0.1 mol / 100 g, and having a vinyl group content bonded to silicon atoms of 0.2 mol / 100 g. Phenyl groups bonded to silicon atoms account for 50% of the total number of substituents bonded to silicon atoms.

[0048] [Synthesis Example 2] Synthesis of branched chain organopolysiloxane (A-2) 743.6 g (3.75 mol) of phenyltrimethoxysilane (KBM-103, manufactured by Shin-Etsu Chemical Co., Ltd.) and 145.3 g (1.25 mol) of vinylmethyldimethoxysilane (KBM-1012, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed, 13.3 g of methanesulfonic acid, 123.9 g of pure water and 1000 g of xylene were added, and the mixture was stirred at 90°C for 4 hours. Thereafter, 25.0 g of a 50 wt% aqueous potassium hydroxide solution was added, and the mixture was further stirred at 130°C for 16 hours. Acetic acid was added to neutralize the solution, followed by washing with 10 wt% aqueous sodium sulfate. The organic layer was subjected to azeotropic dehydration at 120°C for 1 hour, filtered through a 0.45 μm filter paper, and then the solvent was removed by distillation under reduced pressure to prepare branched organopolysiloxane (A-2). The obtained branched organopolysiloxane (A-1) has an average structure of PhSiO 3 / 2 ) 0.75 ((CH2=CH―)MeSiO 2 / 2 ) 0.25 represented by the formula, having T 0.75 D Vi 0.25 represented by the formula, having Mw = 3400, having a hydroxyl group content bonded to silicon atoms of 0.1 mol / 100 g, and having a vinyl group content bonded to silicon atoms of 0.2 mol / 100 g. Phenyl groups bonded to silicon atoms account for 60% of the total number of substituents bonded to silicon atoms.

[0049] [Synthesis Example 3] Synthesis of branched chain organopolysiloxane (A-3) 743.6 g (3.75 mol) of phenyltrimethoxysilane (KBM-103, manufactured by Shin-Etsu Chemical Co., Ltd.) and 243.0 g (1.25 mol) of vinylphenyldimethoxysilane (KBM-1102, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed, and 15.0 g of methanesulfonic acid, 123.9 g of pure water, and 1000 g of xylene were added. The mixture was stirred at 90°C for 4 hours. Then, 25.0 g of 50 wt% aqueous potassium hydroxide solution was added, and the mixture was stirred at 130°C for 16 hours. Acetic acid was added to neutralize the solution, and the mixture was washed with 10 wt% Glauber's salt solution. The organic layer was azeotropically dehydrated at 120°C for 1 hour, filtered through 0.45 μm filter paper, and the solvent was removed by vacuum distillation to prepare branched organopolysiloxane (A-3). The resulting branched organopolysiloxane (A-3) has an average structure (PhSiO 3 / 2 ) 0.75 ((CH2=CH―)PhSiO 2 / 2 ) 0.25 It has T 0.75 D Vi 0.25 It is represented as having Mw=2000. The amount of hydroxyl groups bonded to silicon atoms is 0.1 mol / 100g, and the amount of vinyl groups bonded to silicon atoms is 0.2 mol / 100g. It has 80% of the total number of substituents bonded to silicon atoms as phenyl groups.

[0050] [Synthesis Example 4] Synthesis of branched-chain organopolysiloxane (A-4) 743.6 g (3.75 mol) of phenyltrimethoxysilane (KBM-103, manufactured by Shin-Etsu Chemical Co., Ltd.) and 290.2 g (1.25 mol) of trimethoxy(7-octen-1-yl)silane (KBM-1083, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed, and 13.9 g of methanesulfonic acid, 123.9 g of pure water, and 1000 g of xylene were added. The mixture was stirred at 90°C for 4 hours. Then, 25.0 g of 50 wt% aqueous potassium hydroxide solution was added, and the mixture was stirred at 130°C for 16 hours. Acetic acid was added to neutralize the solution, and the mixture was washed with 10 wt% Glauber's salt solution. The organic layer was azeotropically dehydrated at 120°C for 1 hour, filtered through 0.45 μm filter paper, and the solvent was removed by vacuum distillation to prepare branched organopolysiloxane (A-4). The resulting branched organopolysiloxane (A-4) has an average structure (PhSiO 3 / 2 ) 0.75 ((CH2=CH(CH2)6―)SiO 3 / 2 ) 0.25 It has T 0.75 T Vi 0.25 It is shown as having Mw=7000. The amount of hydroxyl groups bonded to silicon atoms is 0.1 mol / 100g, and the amount of vinyl groups bonded to silicon atoms is 0.2 mol / 100g. It has 60% of the total number of substituents bonded to silicon atoms as phenyl groups.

[0051] [Synthesis Example 5] Synthesis of branched-chain organopolysiloxane (A-5) 743.6 g (3.75 mol) of phenyltrimethoxysilane (KBM-103, manufactured by Shin-Etsu Chemical Co., Ltd.) and 185.1 g (1.25 mol) of vinyltrimethoxysilane (KBM-1003, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed, and 13.9 g of methanesulfonic acid, 123.9 g of pure water, and 1000 g of xylene were added. The mixture was stirred at 90°C for 4 hours. Then, 25.0 g of 50 wt% aqueous potassium hydroxide solution was added, and the mixture was stirred at 130°C for 16 hours. Acetic acid was added to neutralize the solution, and the mixture was washed with 10 wt% Glauber's salt solution. The organic layer was azeotropically dehydrated at 120°C for 1 hour, filtered through 0.45 μm filter paper, and the solvent was removed by vacuum distillation to prepare branched organopolysiloxane (A-5). The obtained branched organopolysiloxane (A-5) has an average structure (PhSiO 3 / 2 ) 0.75 ((CH2=CH―)SiO 3 / 2 ) 0.25 It has T 0.75 T Vi 0.25 It is shown as having Mw=11200. The amount of hydroxyl groups bonded to silicon atoms is 0.1 mol / 100g, and the amount of vinyl groups bonded to silicon atoms is 0.2 mol / 100g. It has 75% of the total number of substituents bonded to silicon atoms as phenyl groups.

[0052] The hydrosilyl group-containing organosilicon compounds used in the examples are as follows: (B-1) Formula (4) below: [ka] Organohydrogensiloxane (with a hydrogen atom weight of 0.6 mol / 100g bonded to silicon atoms, liquid at room temperature (25°C)) (B-2) Formula (5) below: [ka] The organosylphenylene compound shown (hydrogen atom weight bonded to silicon atom: 1.04 mol / 100g)

[0053] [Example 1] As component (A), 100 parts of the branched organopolysiloxane (A-1) obtained in Synthesis Example 1 was added, as component (B), an amount of organohydrogensiloxane (B-1) represented by the above formula (4) was added such that the ratio of the total number of silicon atom-bonded hydrogen atoms in component (B) to the total number of vinyl groups in component (A) (SiH / SiVi) was 1.2, and as component (C), 0.1 parts of an octyl alcohol-modified solution of chloroplatinic acid (platinum element content: 1% by mass) was added and the mixture was stirred well to prepare a silicone resin composition. This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the physical properties described above were measured. The results are shown in Tables 1-1 and 1-2.

[0054] [Example 2] A silicone resin composition was obtained by repeating the procedure of Example 1, except that 100 parts of the branched organopolysiloxane (A-2) obtained in Synthesis Example 2 were used as component (A) instead of the branched organopolysiloxane (A-1) used in Example 1. This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the physical properties described above were measured. The results are shown in Tables 1-1 and 1-2.

[0055] [Example 3] A silicone resin composition was obtained by repeating the procedure of Example 1, except that 100 parts of the branched organopolysiloxane (A-3) obtained in Synthesis Example 3 were used as component (A) instead of the branched organopolysiloxane (A-1) used in Example 1. This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the physical properties described above were measured. The results are shown in Tables 1-1 and 1-2.

[0056] [Example 4] A silicone resin composition was obtained by repeating the procedure of Example 1, except that 100 parts of the branched organopolysiloxane (A-4) obtained in Synthesis Example 4 were used as component (A) instead of the branched organopolysiloxane (A-1) used in Example 1. This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the physical properties described above were measured. The results are shown in Tables 1-1 and 1-2.

[0057] [Example 5] As component (A), 100 parts of the branched organopolysiloxane (A-5) obtained in Synthesis Example 5 was added; as component (B), an amount of organohydrogensiloxane (B-1) represented by the above formula (4) was added such that the ratio (SiH / SiVi) of the total number of silicon atom-bonded hydrogen atoms in component (B) to the total number of vinyl groups in component (A) was 1.2; as component (C), 0.1 parts of an octyl alcohol-modified solution of chloroplatinic acid (platinum element content: 1% by mass) was added; and as component (D), 8 parts of cyclopentanone were added and thoroughly stirred to prepare a silicone resin composition. This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the physical properties described above were measured. The results are shown in Tables 1-1 and 1-2.

[0058] [Examples 6-9] In Examples 1 to 4, the hydrosilyl compound (B-1) was replaced with the organosylphenylene compound (B-2) represented by formula (5) above, and the (B-2) component was added in an amount that resulted in a SiH / SiVi ratio of 1.2. The procedure of Examples 1 to 4 was repeated to obtain a cured silicone resin composition. This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the physical properties described above were measured. The results are shown in Tables 1-1 and 1-2.

[0059] [Example 10] As component (A), 100 parts of the branched organopolysiloxane (A-5) obtained in Synthesis Example 5 was added; as component (B), an amount of the organosylphenylene compound (B-2) represented by the above formula (5) was added such that the ratio (SiH / SiVi) of the total number of silicon atom-bonded hydrogen atoms in component (B) to the total number of vinyl groups in component (A) was 1.2; as component (C), 0.1 parts of an octyl alcohol-modified solution of chloroplatinic acid (platinum element content: 1% by mass) was added; and as component (D), 15 parts of cyclopentanone were added and thoroughly stirred to prepare a silicone resin composition. This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the physical properties described above were measured. The results are shown in Tables 1-1 and 1-2.

[0060] [Comparative Synthesis Example 1] 743.7 g (3.75 mol) of phenyltrimethoxysilane (KBM-103, manufactured by Shin-Etsu Chemical Co., Ltd.) and 116.3 g (0.65 mol) of divinyltetramethyldisiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed, and 13.0 g of methanesulfonic acid, 107.0 g of pure water, and 1000 g of xylene were added. The mixture was stirred at 90°C for 4 hours. Then, 25.0 g of 50 wt% aqueous potassium hydroxide solution was added, and the mixture was stirred at 130°C for 16 hours. Acetic acid was added to neutralize the solution, and the mixture was washed with 10 wt% Glauber's salt solution. The organic layer was azeotropically dehydrated at 120°C for 1 hour, filtered through 0.45 μm filter paper, and the solvent was removed by vacuum distillation to prepare branched organopolysiloxane (A-6). The resulting branched organopolysiloxane (A-6) has an average structure (PhSiO 3 / 2 ) 0.75 ((CH2=CH―)Me2SiO 1 / 2 ) 0.25 It has T 0.75 M Vi 0.25 It is represented as having Mw=1400. The amount of hydroxyl groups bonded to silicon atoms is 0.1 mol / 100g, and the amount of vinyl groups bonded to silicon atoms is 0.2 mol / 100g. The amount of phenyl groups bonded to silicon atoms is 50% of the total number of substituents bonded to silicon atoms.

[0061] [Comparative Synthesis Example 2] 743.7 g (3.75 mol) of phenyltrimethoxysilane (KBM-103, manufactured by Shin-Etsu Chemical Co., Ltd.) and 193.9 g (0.65 mol) of divinyldimethyldiphenyldisiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed, and 14.1 g of methanesulfonic acid, 107.0 g of pure water, and 1000 g of xylene were added. The mixture was stirred at 90°C for 4 hours. Then, 25.0 g of 50 wt% aqueous potassium hydroxide solution was added, and the mixture was stirred at 130°C for 16 hours. Acetic acid was added to neutralize the solution, and the mixture was washed with 10 wt% Glauber's salt solution. The organic layer was dehydrated azeotropically at 120°C for 1 hour, filtered through 0.45 μm filter paper, and the solvent was removed by vacuum distillation to prepare branched organopolysiloxane (A-7). The resulting branched organopolysiloxane (A-7) has an average structure (PhSiO 3 / 2 ) 0.75 ((CH2=CH―)PhMeSiO 1 / 2 ) 0.25 It has T 0.75 M Vi 0.25 It is shown as having Mw=1400. The amount of hydroxyl groups bonded to silicon atoms is 0.1 mol / 100g, and the amount of vinyl groups bonded to silicon atoms is 0.2 mol / 100g. It has 60% of the total number of substituents bonded to silicon atoms as phenyl groups.

[0062] [Comparative Example 1] A silicone resin composition was obtained by repeating the procedure of Example 1, except that the branched organopolysiloxane (A-1) in Example 1 was replaced with the branched organopolysiloxane (A-6) obtained in Comparative Synthesis Example 1. This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the above-mentioned physical properties were measured. The results are shown in Table 2.

[0063] [Comparative Example 2] A silicone resin composition was obtained by repeating the procedure of Example 1, except that the branched organopolysiloxane (A-1) in Example 1 was replaced with the branched organopolysiloxane (A-7) obtained in Comparative Synthesis Example 2. This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the above-mentioned physical properties were measured. The results are shown in Table 2.

[0064] [Comparative Example 3] (A) Instead of the branched organopolysiloxane (A-1) used in Example 1, the following formula (6) [ka] (In the equation, m=9 and n=19) A silicone resin composition was obtained by repeating the procedure of Example 1, except that a linear organopolysiloxane (A-8) indicated by [the formula shown] was used. This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the above-mentioned physical properties were measured. The results are shown in Table 2.

[0065] [Comparative Example 4] A silicone resin composition was obtained by repeating the procedure of Example 6, except that the branched organopolysiloxane (A-1) of Example 6 was replaced with the branched organopolysiloxane (A-6) obtained in Comparative Synthesis Example 1 as component (A). This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the above-mentioned physical properties were measured. The results are shown in Table 2.

[0066] [Comparative Example 5] A silicone resin composition was obtained by repeating the procedure of Example 7, except that the branched organopolysiloxane (A-2) used in Example 7 was replaced with the branched organopolysiloxane (A-7) obtained in Comparative Synthesis Example 2 as component (A). This composition was heated and molded at 180°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the above-mentioned physical properties were measured. The results are shown in Table 2.

[0067] The composition and physical property evaluation results of each silicone resin composition and its cured product obtained in the above examples and comparative examples are shown in Tables 1-1 and 1-2, and Table 2, respectively.

[0068] [Table 1-1]

[0069] [Table 1-2]

[0070] [Table 2]

[0071] As shown in Table 2, the silicone resin compositions of Comparative Examples 1, 2, 4, and 5, which contained branched organopolysiloxanes having alkenyl groups in the M units and lacking alkenyl group-containing T and D units, exhibited poor adhesion and sulfurization resistance in the resulting cured products. Furthermore, the cured product obtained from the silicone resin composition of Comparative Example 3, which contained linear alkenyl group-containing organopolysiloxane, exhibited poor hardness, adhesion, and sulfurization resistance. On the other hand, as shown in Table 1, the silicone resin compositions of Examples 1 to 10, in which the branched-chain organopolysiloxane has alkenyl group-containing T units or D units, yielded cured products with sufficient viscosity, appearance, refractive index, hardness, adhesive strength, and excellent sulfidation resistance. This is because the cured products obtained due to the branched-chain organopolysiloxane have a rigid structure and maintain a high modulus of elasticity even at high temperatures. [Industrial applicability]

[0072] The silicone resin composition of the present invention can provide cured products suitable for use as lens materials, protective coatings, and molding agents for light-emitting semiconductor devices, exhibiting excellent gas permeability resistance.

[0073] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention.

Claims

1. (A) A branched organopolysiloxane represented by the following average formula, having 10% or more aryl groups bonded to silicon atoms relative to the total number of substituents bonded to silicon atoms, and having at least two silicon-bonded alkenyl groups in one molecule. (SiO ４／２ ) ａ (R １ SiO ３／２ ) ｂ (R ２ SiO ３／２ ) ｃ (R ２ R ３ SiO ２／２ ) ｄ (1) (In the above formula, R １ R is independently a hydroxyl group, a carbon 1-10 alkoxy group, a carbon 1-10 substituted or unsubstituted alkyl group other than an alkenyl group, or a carbon 6-10 aryl group, ２ These are, independently of each other, alkenyl groups having 2 to 10 carbon atoms, and R ３ (A, B, C, and D are independently substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms other than hydroxyl groups, alkoxy groups having 1 to 10 carbon atoms, alkenyl groups, or aryl groups having 6 to 10 carbon atoms, and a, b, c, and d are numbers satisfying a≧0, b>0, c≧0, and d≧0 respectively, provided that c+d>0 and a+b+c+d=1) (B) A hydrosilyl group-containing organosilicon compound having two or more SiH groups in one molecule, in an amount such that the ratio of the number of hydrosilyl groups in component (B) to the number of alkenyl groups in component (A) is 0.1 to 4.0, and (C) Platinum group metal catalyst catalyst amount A silicone resin composition containing the following:

2. The silicone resin composition according to claim 1, wherein in formula (1), a is a number from 0 to 0.6, b is a number from 0.1 to 0.9, c is a number from 0 to 0.5, d is a number from 0 to 0.5, c + d > 0, and a + b + c + d = 1.

3. The silicone resin composition according to claim 1, wherein component (B) is an organosilicon compound selected from organohydrogen(poly)siloxane, organo(poly)sylphenylene, and organo(poly)sylphenylenesiloxane, having 2 to 200 silicon atoms in one molecule and one or more silicon atom-bonded aryl groups in one molecule.

4. The silicone resin composition according to claim 1, wherein component (A) has a weight-average molecular weight of 1,000 to 50,000 with polystyrene as the standard substance determined by gel permeation chromatography.

5. A cured product of a silicone resin composition according to any one of claims 1 to 4.

6. The cured product according to claim 5, characterized in that the type D hardness of the cured product, as measured by the method described in JIS K 6253-3, is in the range of 30 to 90.

7. The cured product according to claim 5, characterized in that the refractive index of the cured product at a wavelength of 589 nm, as measured by the method described in JIS K 0062, is in the range of 1.45 to 1.

60.

8. An optoelectronic device comprising a cured product and an optoelectronic semiconductor element according to any one of claims 5 to 7.

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