Thermosetting epoxy-silicone hybrid resin composition for white reflector, and optical semiconductor device

Abstract

Provided is a resin composition whereby it is possible to obtain a cured product having excellent bending characteristics at room temperature, excellent initial reflectance and heat resistance, low light transmittance, and excellent adhesiveness to a substrate plated with a metal such as gold or silver. The present invention is a thermosetting epoxy-silicone hybrid resin composition for a white reflector, said composition containing: (A) a prepolymer that is a reaction product of (A-1), (A-2), and (A-3), namely, (A-1) an organopolysiloxane having at least a D unit containing an aliphatic epoxy group and a T unit containing an aromatic hydrocarbon group, (A-2) a specific epoxy resin, and (A-3) an acid anhydride-based curing agent; (B) zinc cyanurate; (C) a white pigment; (D) an inorganic filler; (E) a curing catalyst; and (F) an antioxidant.

Description

Thermosetting epoxy-silicone hybrid resin composition for white reflectors and optoelectronic devices

[0001] The present invention relates to a thermosetting epoxy-silicone hybrid resin composition for white reflectors and an optoelectronic device using the composition.

[0002] Various optoelectronic semiconductor devices, such as LEDs (Light Emitting Diodes), are increasingly being used as indicators and light sources in various applications, including street displays, automotive lamps, and residential lighting. In particular, white LEDs are seeing rapid development in various fields due to their potential to reduce carbon dioxide emissions and conserve energy.

[0003] Polyphthalamide resin (PPA), a thermoplastic resin, has been widely used as a light reflector material (reflective material) in semiconductor and electronic devices such as LEDs. However, due to PPA's poor resistance to heat and light discoloration, the use of thermosetting resins, such as epoxy resins, which have high heat and light resistance and high strength, is expanding. In particular, in recent years, with the trend towards higher output and higher brightness of LED elements, polyfunctional epoxy resins and alicyclic epoxy resins are being used as light reflector materials to improve heat and light resistance. Some of these materials are solid at room temperature and can be molded by transfer molding or compression molding, making it possible to mold even complex package shapes (Patent Documents 1-3). Further heat resistance is required for such epoxy resins, and in order to solve these problems, reports have been made on white thermosetting resin compositions using silicone resins (Patent Document 4) and epoxy-silicone hybrid resins (Patent Documents 5, 6).

[0004] However, the silicone resin described in Patent Document 4 is an addition-curing type, and although its heat resistance is significantly better than that of epoxy resin, it is inferior to epoxy resin in terms of compositional strength. The epoxy-silicone hybrid resins described in Patent Documents 5 and 6 show improvement in strength compared to silicone resin, but they are still not sufficient in terms of having both high strength and high heat resistance. Therefore, there is a need for the development of materials that have both high strength and high heat resistance.

[0005] Furthermore, the size of molded packages, such as those using the MAP (Matrix Array Package) method, is increasing, and the thickness of the molded packages is also decreasing. The thinning of the molded packages has a significant impact on optical properties, particularly light transmittance, and there is a need for the development of resin compositions for encapsulating LED elements that exhibit low light transmittance. Generally, optical semiconductor cases for LEDs and the like are constructed by mounting the LED chip on a lead frame, wire bonding it, sealing it with epoxy resin or silicone resin, and then sealing it again with a reflector material to prevent light leakage from the LED. Silver-plated copper frames, gold-plated copper frames, etc., are used as lead frames. Adhesion between the reflector material and the lead frame is required in this process. Until now, coupling agents such as mercapto-functional alkoxysilanes have been added as adhesive aids to resin compositions for optical semiconductor cases, such as reflector materials (Patent Document 7).

[0006] However, with conventional optoelectronic semiconductor cases formed from cured epoxy resin compositions, adhesion to the lead frame may be insufficient depending on the type of plating. In particular, during high-temperature (215-260°C) reflow processes, delamination occurs at the interface between the lead frame and the cured resin, posing a major problem as the reliability of the semiconductor device cannot be guaranteed.

[0007] Japanese Patent Publication No. 2006-140207, Japanese Patent Publication No. 2008-189827, Japanese Patent Publication No. 2013-100410, Japanese Patent Publication No. 2016-076723, Japanese Patent Publication No. 2013-079328, Japanese Patent Publication No. 2013-135120, Japanese Patent Publication No. 2012-41428

[0008] Therefore, the present invention aims to provide a thermosetting epoxy-silicone hybrid resin composition for white reflectors that can provide a cured product with excellent bending properties at room temperature, excellent initial reflectivity and heat resistance, low light transmittance, and excellent adhesion to substrates plated with metals such as gold and silver, and a semiconductor device comprising a cured product of the composition.

[0009] As a result of diligent research to achieve the above objective, the inventors of the present invention discovered that the cured product of the following thermosetting epoxy-silicone hybrid resin composition containing zinc cyanurate can achieve the above objective, and thus completed the present invention.

[0010] In other words, the present invention provides a thermosetting epoxy-silicone hybrid resin composition for white reflectors and a white reflector made from a cured product of the composition. [1] (A) A prepolymer which is a reaction product of (A-1), (A-2), and (A-3) below, (A-1) The average composition formula (1) below (In the formula, R 1 R is independently a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, or a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms. 2 R is a monovalent aliphatic epoxy group having 4 to 30 carbon atoms. 3 R is a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, or a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, where 0 ≤ x < 0.4, 0.1 ≤ y ≤ 0.5, 0.4 ≤ z ≤ 0.8, and x + y + z = 1. The bonding order of each siloxane unit is not restricted. ) is represented as, and the total R in one molecule 3(A-2) Organopolysiloxane having a proportion of 30 mol% to 100 mol% of monovalent aromatic hydrocarbon groups having 6 to 12 carbon atoms: 100 parts by mass (A-2) Epoxy resin having two or more epoxy groups in one molecule, one or more epoxy resins selected from the group consisting of triazine derivative epoxy resins, bisphenol type epoxy resins, hydrogenated bisphenol type epoxy resins, and alicyclic epoxy resins: 10 to 100 parts by mass (A-3) Acid anhydride curing agent: an amount such that the number of acid anhydride groups in component (A-3) is 0.3 to 1.0 for each epoxy group in component (A-1) and component (A-2) (B) Zinc cyanurate: 0.1 to 10 parts by mass per 100 parts by mass of the prepolymer of component (A), (C) White pigment: 3 to 350 parts by mass per 100 parts by mass of the prepolymer of component (A) (except for (B) zinc cyanurate), A thermosetting epoxy-silicone hybrid resin composition for white reflectors containing (D) inorganic filler: 80 to 600 parts by mass per 100 parts by mass of the prepolymer of component (A) (excluding (B) zinc cyanurate and (C) white pigment), (E) curing catalyst: 0.05 to 5 parts by mass per 100 parts by mass of the prepolymer of component (A), and (F) antioxidant: 0.5 to 5 parts by mass per 100 parts by mass of the prepolymer of component (A). [2] In formula (1), R 2 A thermosetting epoxy-silicone hybrid resin composition for white reflectors according to [1], wherein the group is represented by the following formula (2). (In the formula, R' is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 4(I is a divalent hydrocarbon group having 1 to 20 carbon atoms.) [3] The thermosetting epoxy-silicone hybrid resin composition for white reflectors according to [1] or [2], wherein the (A-2) component is a triazine derivative epoxy resin. [4] The thermosetting epoxy-silicone hybrid resin composition for white reflectors according to any one of [1] to [3], wherein the white pigment of the (C) component is titanium oxide whose surface is treated with alumina, and then treated with one or more treatment agents selected from the group consisting of silica, alumina, zirconia, polyol, and siloxane. [5] The thermosetting epoxy-silicone hybrid resin composition for white reflectors according to any one of [1] to [4], wherein the (F) component is a combination of a phenolic antioxidant and a phosphorus-based antioxidant. [6] An optoelectronic device comprising a cured product of the thermosetting epoxy-silicone hybrid resin composition for white reflectors according to any one of [1] to [5].

[0011] The white thermosetting epoxy-silicone hybrid resin composition of the present invention exhibits excellent bending properties at room temperature, as well as excellent initial reflectivity and heat resistance. The cured product has low light transmittance and excellent adhesion to substrates plated with metals such as gold and silver. Therefore, the white thermosetting epoxy-silicone hybrid resin composition of the present invention can be suitably used as a material for reflectors and cases of optoelectronic devices. Furthermore, optoelectronic devices using cured products of such white thermosetting epoxy-silicone hybrid resin compositions as reflectors or cases for photodetectors and other semiconductor elements exhibit superior reliability.

[0012] The present invention will be described in more detail below.

[0013] <(A) Prepolymer> The (A) component of the thermosetting epoxy-silicone hybrid resin composition for a white reflector of the present invention is a prepolymer which is a reaction product of the following (A-1) to (A-3) components. The above (A) component is, for example, a reaction product obtained by reacting the (A-1) component, the (A-2) component, and the (A-3) component at 60 to 120 ° C, preferably 70 to 110 ° C, for 2 to 20 hours, preferably 2 to 15 hours. Thus, a prepolymer of the (A) component can be obtained as a solid having a softening point of 40 to 100 ° C, preferably 60 to 80 ° C. If the softening point of this prepolymer is 40 ° C or higher, the resulting composition becomes solid at room temperature (25 ° C), and pressure molding at room temperature becomes easy. Further, if the softening point of the prepolymer is 100 ° C or lower, gelation does not proceed too much, and the fluidity required at the time of molding as a composition can be obtained. In the present invention, the softening point is a value measured based on the softening point test method (ring and ball method) specified in JIS K7234: 1986.

[0014] The (A) component is preferably blended in the composition of the present invention at 10 to 45% by mass, more preferably 12 to 40% by mass, still more preferably 15 to 35% by mass. Hereinafter, the (A-1) to (A-3) components will be described in detail.

[0015] [(A-1) Organopolysiloxane] The (A-1) component is an organopolysiloxane represented by the following formula (1). In formula (1), R 1 is independently a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms or a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and R 2 is a monovalent aliphatic epoxy group having 4 to 30 carbon atoms, and R 3 is a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms or a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, where 0 ≦ x <0.4, 0.1 ≦ y ≦ 0.5, 0.4 ≦ z ≦ 0.8, and x + y + z = 1.

[0016] In the above formula (1), R 1 is independently a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms or a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms. R 1The number of carbon atoms of the monovalent aromatic hydrocarbon group represented by is 6 to 12, preferably 6 to 9, and specifically, aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, benzyl group, 2-phenylethyl group, 2-phenylpropyl group, etc. Examples include aralkyl groups. Among them, a phenyl group, a benzyl group, a 2-phenylethyl group, and a 2-phenylpropyl group are preferable, and a phenyl group is more preferable.

[0017] Also, R 1 The number of carbon atoms of the monovalent aliphatic hydrocarbon group represented by is 1 to 12, preferably 1 to 6, and specifically, alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, heptyl group, 2-ethylhexyl group, octyl group, etc., vinyl group, allyl group, isopropenyl group, butenyl group, 2-(3-cyclohexenyl)ethyl group, etc. Examples include alkenyl groups. Among them, an alkyl group is preferable, and particularly, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, and a heptyl group are preferable, and a methyl group is more preferable.

[0018] In the above formula (1), R 2 is a monovalent aliphatic epoxy group having 4 to 30 carbon atoms, preferably 6 to 25 carbon atoms, and more preferably 7 to 20 carbon atoms. Examples of the aliphatic epoxy group include a structure represented by the following formula (2).

[0019] In formula (2), R' is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R 4 is a divalent hydrocarbon group having 1 to 20 carbon atoms.

[0020] In the above formula (2), R' is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and particularly preferably a hydrogen atom. R 4 is a divalent hydrocarbon group having 1 to 20 carbon atoms, and examples thereof include alkylene groups such as methylene group, ethylene group, trimethylene group, etc.

[0021] Among them, as R 2 a monovalent aliphatic epoxy group represented by the following formula (3) is preferable. In formula (3), R 4This is an alkylene group having 1 to 20 carbon atoms, preferably a trimethylene group.

[0022] In the above formula (1), R 3 These are independently monovalent aromatic hydrocarbon groups having 6 to 12 carbon atoms, or monovalent aliphatic hydrocarbon groups having 1 to 12 carbon atoms, and the total R in one molecule 3 Of these, the proportion of monovalent aromatic hydrocarbon groups having 6 to 12 carbon atoms is 30 mol% or more and 100 mol% or less. 3 A preferred example is the above R 1 Examples similar to those shown can be provided.

[0023] In the present invention, formula (1) is the empirical formula, and x, y, and z represent the average number ratio (molar ratio) of each siloxane unit. 0 ≤ x < 0.4, 0.1 ≤ y ≤ 0.5, 0.4 ≤ z ≤ 0.8, and x + y + z = 1. The bonding order of each siloxane unit in the parentheses in formula (1) is not restricted. In formula (1), x is R 1 2SiO 2 / 2 This indicates the content (molar ratio) of the units. The range of x is 0 ≤ x < 0.4, preferably 0 ≤ x < 0.35. In the above formula (1), y is a D unit containing an aliphatic epoxy group, i.e., R 1 R 2 SiO 2 / 2 This indicates the content (molar ratio) of the unit. The range of y is 0.1 ≤ y ≤ 0.5, preferably 0.1 ≤ y ≤ 0.4, and particularly preferably 0.1 ≤ y ≤ 0.35. In the above formula (1), z is a T unit containing an aromatic hydrocarbon group, i.e., R 3 SiO 3 / 2 The content (molar ratio) of the units is shown. The range of z is 0.4 ≤ z ≤ 0.8, preferably 0.5 ≤ z ≤ 0.75, and particularly preferably 0.6 ≤ z ≤ 0.7. Furthermore, (A-1) organopolysiloxane has one or more monovalent aromatic hydrocarbon groups having 6 to 12 carbon atoms as groups that bond to the silicon atom of the T unit in one molecule, and the total R in one molecule 3 Of these, the proportion of monovalent aromatic hydrocarbon groups having 6 to 12 carbon atoms is 30 mol% or more and 100 mol% or less.

[0024] (A-1) The organopolysiloxane preferably has a weight-average molecular weight (Mw) of 1,200 to 8,000 in terms of polystyrene, as measured by gel permeation chromatography (GPC), and more preferably 1,200 to 7,000. If the weight-average molecular weight (Mw) of (A-1) is within the above range, the composition will have good workability and will be easy to handle when forming reflectors, etc. Furthermore, the cured product obtained from the composition will have sufficient mechanical properties. In this invention, weight-average molecular weight refers to the weight-average molecular weight with polystyrene as the standard substance, as measured by gel permeation chromatography (GPC) under the following conditions. [Measurement Conditions] Developing solvent: Tetrahydrofuran (THF) Flow rate: 0.6 mL / min Detector: Differential refractive index detector (RI) Column: TSK Guardcolumn SuperH-L TSKgel SuperHZ4000 (4.6 mm I.D. × 15 cm × 1) TSKgel SuperHZ3000 (4.6 mm I.D. × 15 cm × 1) TSKgel SuperHZ2000 (4.6 mm I.D. × 15 cm × 2) (All manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 20 μL (0.5 wt% THF solution)

[0025] Examples of organopolysiloxanes represented by formula (1) above include the structure shown in the following formula. In the above formula, x, y, and z are as described above. The bonding order of each siloxane unit in the parentheses above is not restricted. Me represents a methyl group.

[0026] The method for producing the organopolysiloxane represented by formula (1) above is not particularly limited. For example, the organopolysiloxane represented by formula (1) above is R 1 2SiO 2 / 2 Unit, R 1 R 2 SiO 2 / 2 Unit, R 3 SiO 3 / 2The units can be obtained by condensing one or more organosilicon compounds having two or more silanol groups or alkoxysilyl groups in one molecule, in the presence of a catalyst. The reaction ratio of the starting compounds should be appropriately adjusted so that the molar ratios x, y, and z of each siloxane unit are within the above range.

[0027] R 1 2SiO 2 / 2 Examples of organosilicon compounds that serve as raw materials for the units include organo(poly)siloxanes represented by the following formula (4). (In the formula, R 1 As described above, X is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably a methyl group. e is a number from 1 to 20.

[0028] Examples of silane compounds represented by the above formula (4) (e=1) include methyldialkoxysilanes shown in the following formula. (wherein X and R 1 (As stated above.)

[0029] In particular, X is a hydrogen atom or a methyl group, and R 1 Preferably, the group is a methyl group or a phenyl group. More preferably, it is a dimethoxysilane.

[0030] Examples of organopolysiloxanes (e=2 to 20) represented by the above formula (4) include oligomers of dialkoxysilanes shown in the following formula. (wherein X and R 1 As stated above, e' is an integer between 2 and 10.

[0031] In particular, X is a hydrogen atom or a methyl group, and R 1 It is preferable that the oligomer is a methyl group or a phenyl group. Among the above oligomers, dimethoxysilane oligomers are particularly preferred from the viewpoint of reactivity, workability, and low gas permeability.

[0032] R 1 R 2 SiO 2 / 2 Examples of organosilicon compounds that serve as raw materials for the units include aliphatic epoxy group-containing silane compounds shown in the following formula.

[0033] R 3 SiO 3 / 2 Examples of organosilicon compounds that serve as raw materials for the units include phenyl group-containing silane compounds shown in the following formula.

[0034] The condensation reaction to obtain the organopolysiloxane shown in formula (1) above can be carried out using conventionally known catalysts. For example, as a condensation reaction between an organo(poly)siloxane having silanol groups and / or alkoxy groups at both terminal ends containing a phenyl group and an alkoxysilane compound having substituents such as an alicyclic epoxy group, strong bases such as sodium hydroxide, potassium hydroxide, tetramethylammonia hydroxide, diazabicycloundecene, and 1,4-diazabicyclo[2.2.2]octane can be used.

[0035] [(A-2) Epoxy resin having two or more epoxy groups in one molecule] Component (A-2) is an epoxy resin having two or more epoxy groups in one molecule, and is one or more epoxy resins selected from the group consisting of triazine derivative epoxy resins, bisphenol type epoxy resins, hydrogenated bisphenol type epoxy resins, and alicyclic epoxy resins. Component (A-2) is preferably a triazine derivative epoxy resin from the viewpoint of heat resistance, UV resistance, and high Tg.

[0036] The epoxy resin of component (A-2) preferably has a monovalent aliphatic epoxy group represented by the above formula (2), and more preferably has three monovalent aliphatic epoxy groups represented by the above formula (2), and among these monovalent aliphatic epoxy groups, R 4 These may be different from each other. Specific examples of the epoxy resin of component (A-2) having a monovalent aliphatic epoxy group represented by formula (2) above include 1-methyl-3,5-diglycidyl isocyanurate and 1,3,5-triglycidyl isocyanurate. In particular, 1,3,5-triglycidyl isocyanurate represented by the following formula (5) is preferred.

[0037]

[0038] The amount of epoxy resin component (A-2) is 10 to 100 parts by mass, preferably 20 to 80 parts by mass, per 100 parts by mass of component (A-1). If the amount of component (A-2) is less than 10 parts by mass, a sufficient Tg cannot be obtained, and if it exceeds 100 parts by mass, the heat resistance and UV resistance will decrease.

[0039] [(A-3) Acid anhydride-based curing agent] Component (A-3) is an acid anhydride-based curing agent that is reactive with epoxy groups. Examples of the above acid anhydride-based curing agent include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, 3-methyl-hexahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride, a mixture of 3-methyl-hexahydrophthalic anhydride and 4-methyl-hexahydrophthalic anhydride, tetrahydrophthalic anhydride, nadic anhydride, methylnadic anhydride, norbornane-2,3-dicarboxylic acid anhydride, methylnorbornane-2,3-dicarboxylic acid anhydride, 2,4-diethylglutaric anhydride, and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride. Among these, acid anhydrides having an alicyclic hydrocarbon structure are preferred, and it is more preferable to use two or more acid anhydrides in combination. In particular, it is even more preferable to use 4-methyl-hexahydrophthalic anhydride and its derivatives, and especially 4-methyl-hexahydrophthalic anhydride and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride in combination.

[0040] The amount of acid anhydride-based curing agent in component (A-3) is such that the ratio of acid anhydride groups in component (A-3) to one epoxy group in components (A-1) and (A-2), i.e., the ratio of the number of acid anhydride groups in component (A-3) to the total number of epoxy groups in components (A-1) and (A-2), is 0.3 to 1.0, preferably 0.4 to 0.8. If the above ratio is less than 0.3, the heat resistance of the cured product will decrease. If the above ratio is greater than 1.0, the mechanical properties of the cured product will decrease.

[0041] <(B) Zinc Cyanurate> The resin composition of the present invention contains zinc cyanurate. Zinc cyanurate is added for the purpose of improving the adhesion between the cured resin composition and the metal substrate. Since zinc cyanurate is a white powder with excellent heat resistance, it can improve the adhesion to the metal substrate without reducing the initial reflectance or heat resistance of the cured product of the thermosetting epoxy-silicone hybrid resin composition for white reflectors. In addition, because zinc cyanurate has a high refractive index of 1.7, the difference in refractive index with the prepolymer of component (A) can reduce the transmittance of the cured product of the thermosetting epoxy-silicone hybrid resin composition for white reflectors.

[0042] A commercially available zinc cyanurate can be used, and an example of such a product is "Starfine F-10" (average particle size: 1.7 μm) manufactured by Nissan Chemical Corporation. The average particle size and shape of component (B) are not particularly limited, but from the viewpoint of the fluidity of the resin composition, the average particle size is preferably in the range of 0.1 μm to 50 μm, and more preferably in the range of 0.5 μm to 30 μm. The average particle size is the mass-mean value D obtained by particle size distribution measurement by laser light diffraction. 50 This is the value obtained as (or median diameter).

[0043] The amount of component (B) is 0.1 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the prepolymer of component (A). Within this range, the effect of improving adhesion by component (B) is sufficiently obtained, and the fluidity during molding does not decrease, which is preferable.

[0044] <(C) White Pigment> The thermosetting epoxy-silicone hybrid resin composition for white reflectors of the present invention contains a white pigment as component (C). This white pigment is added to increase the whiteness for applications such as reflectors in optoelectronic devices. Examples of white pigments include rare earth oxides such as titanium dioxide and yttrium oxide, zinc sulfate, zinc oxide, and magnesium oxide, which can be used individually or in combination of several types. Note that zinc cyanurate, which is component (B), is not included in the white pigment of component (C).

[0045] The white pigment of component (C) is not limited in terms of average particle size and shape, but the average particle size is preferably 0.05 to 5.0 μm, more preferably 1.0 μm or less, and even more preferably 0.3 μm or less. Of these, titanium dioxide is preferably used as the white pigment of component (C) to further increase the whiteness. The unit cell of titanium dioxide may be rutile, anatase, or brookite, but the rutile type is preferred from the viewpoint of the whiteness of titanium dioxide and photocatalytic activity. The average particle size and shape of titanium dioxide are also not limited, but the average particle size is preferably 0.05 to 5.0 μm, more preferably 1.0 μm or less, and even more preferably 0.3 μm or less. The average particle size is the mass mean D of particle size distribution measurement by laser diffraction. 50 This was determined as (or median diameter).

[0046] Furthermore, titanium dioxide produced by any method, such as the sulfuric acid method or the chlorine method, can be used, but from the viewpoint of whiteness, titanium dioxide produced by the chlorine method is preferred. The above titanium dioxide is preferably surface-treated in order to improve its wettability, compatibility, dispersibility, and fluidity with the prepolymer of component (A) and the inorganic filler of component (D) described later. It is more preferable that the surface is treated with alumina, and then with one or more, particularly two or more, treatment agents selected from silica, alumina, zirconia, polyol, and organosilicon compounds. In other words, to improve the dispersibility of titanium dioxide, titanium dioxide that has been pre-surface-treated with alumina, silica, zirconia, or other hydrated oxides is preferred. To improve wettability and compatibility with component (A), titanium dioxide treated with polyol is preferred. In addition, to improve the initial reflectance and fluidity of the cured product obtained from the white thermosetting epoxy-silicone hybrid resin of the present invention, titanium dioxide treated with organosilicon compounds is preferred. Examples of organosilicon compounds include monomeric organosilicon compounds such as chlorosilanes, silazanes, and silane coupling agents having reactive functional groups such as epoxy groups and amino groups, as well as organopolysiloxanes such as silicone oils and silicone resins. Other treatment agents commonly used for surface treatment of titanium dioxide, such as organic acids like stearic acid, may also be used. Surface treatment with agents other than those mentioned above, or with multiple treatment agents, is also permitted.

[0047] The amount of the white pigment is 3 to 350 parts by mass, and particularly preferably 5 to 300 parts by mass, per 100 parts by mass of the prepolymer of component (A). If the amount of white pigment is less than 3 parts by mass, sufficient whiteness may not be obtained. Furthermore, if the amount of white pigment exceeds 350 parts by mass, not only will the proportion of other components added for the purpose of improving the mechanical strength of the cured product decrease, but the moldability of the epoxy-silicone hybrid resin composition may also decrease significantly. The amount of white pigment is preferably in the range of 1 to 50% by mass, and particularly preferably 3 to 40% by mass, of the total thermosetting epoxy-silicone hybrid resin composition for white reflectors.

[0048] <(D) Inorganic Filler> The thermosetting epoxy-silicone hybrid resin composition for white reflectors of the present invention further contains an inorganic filler as component (D). As such an inorganic filler, those that are normally blended into epoxy resin compositions can be used. Specifically, examples include silicas such as fused silica and crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, antimony trioxide, glass fibers, and potassium titanate, but the zinc cyanurate of component (B) and the white pigment of component (C) mentioned above are not included in component (D). The average particle size and shape of these inorganic fillers are not particularly limited, but the average particle size is preferably from more than 3 μm to 50 μm or less. The average particle size is the cumulative mass mean D of particle size distribution measurement by laser diffraction. 50 This was determined as (or median diameter).

[0049] Component (D) is preferably a silica-based inorganic filler such as crushed silica or molten spherical silica, with molten spherical silica being more preferred from the viewpoint of moldability and fluidity. The average particle size of the silica-based inorganic filler is not particularly limited, but is preferably 4 to 40 μm, and more preferably 7 to 35 μm. Furthermore, for even higher fluidity, it is preferable to use a combination of fine particles in the 0.1 to 3 μm range, medium particles in the 4 to 8 μm range, and coarse particles in the 10 to 50 μm range.

[0050] The inorganic filler of component (D) described above may be pre-surface-treated with a coupling agent such as a silane coupling agent or a titanate coupling agent in order to strengthen the bonding strength with the prepolymer of component (A) or the white pigment of component (C), or to lower the viscosity of the composition during molding and make it highly fluid. Suitable coupling agents include, for example, epoxy-functionalized alkoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and mercapto-functionalized alkoxysilanes such as γ-mercaptopropyltrimethoxysilane. In particular, it is preferable to use a coupling agent other than amine-based silane coupling agents that easily discolor the treated filler over time. The amount of coupling agent used for surface treatment and the surface treatment method are not particularly limited and may be carried out according to conventional methods.

[0051] The amount of the inorganic filler is 80 to 600 parts by mass, preferably 200 to 500 parts by mass, per 100 parts by mass of the prepolymer of component (A). If the amount of inorganic filler is less than 80 parts by mass, sufficient strength may not be obtained, and burrs may be generated during molding, or the difference in thermal expansion coefficients between the lead frame and the cured product may be too large, causing warping of the cured product. On the other hand, if the amount of inorganic filler exceeds 600 parts by mass, the increased viscosity of the thermosetting epoxy-silicone hybrid resin composition for white reflectors may result in unfilled defects or loss of flexibility, which can increase the stress on the cured product of the resin composition and cause defects such as peeling of the lead frame. The amount of inorganic filler of component (D) is preferably in the range of 10 to 90% by mass, particularly 20 to 80% by mass, of the total thermosetting epoxy-silicone hybrid resin composition for white reflectors.

[0052] <(E) Curing Catalyst> The curing catalyst, which is component (E) of the thermosetting epoxy-silicone hybrid resin composition for white reflectors of the present invention, is not particularly limited and can be selected from curing catalysts conventionally used in epoxy resin compositions. For example, quaternary phosphonium salts such as tetrabutylphosphonium-o,o-diethyl phosphorodithioate and tetraphenylphosphonium-tetraphenylborate, organic phosphine-based curing catalysts such as triphenylphosphine and diphenylphosphine, tertiary amine-based curing catalysts such as 1,8-diazabicyclo[5.4.0]undecene-7, triethanolamine, and benzyldimethylamine, 1,8-diazabicyclo[5.4.0]undecene-7 phenol salt, 1,8-diazabicyclo[5.4.0]undecene-7 octylate, 1,8-diazabicyclo[5.4.0]undecene-7 p-toluenesulfonate, 1,8-diazabicyclo[5.4.0]undecene-7 Examples include quaternary ammonium salts such as formate, organic carboxylates such as zinc octoate and zinc naphthylate, aluminum chelate compounds such as aluminum bis-ethyl acetate monoacetylacetonate and aluminum ethyl acetate diisopropylate, and imidazoles such as 2-methylimidazole and 2-phenyl-4-methylimidazole. Among these, quaternary phosphonium salts and quaternary ammonium salts are preferred.

[0053] The amount of curing catalyst to be added is 0.05 to 5 parts by mass, preferably 0.1 to 1.5 parts by mass, per 100 parts by mass of the prepolymer of component (A). If the amount of curing catalyst is less than 0.05 parts by mass, the effect of promoting the reaction between the epoxy resin and the curing agent may not be sufficiently obtained. If the amount of curing catalyst is more than 5 parts by mass, it may cause discoloration during curing or reflow testing.

[0054] <(F) Antioxidant> The thermosetting epoxy-silicone hybrid resin composition for white reflectors of the present invention contains an antioxidant as component (F) to improve initial reflectivity and maintain reflectivity over the long term. As the antioxidant for component (F), a phenol-based, phosphorus-based, or sulfur-based antioxidant can be used, and specifically, the following antioxidants can be mentioned.

[0055] Examples of phenolic antioxidants include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), and 3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4 Examples include [-hydroxy-5-methylphenyl)propionyloxyethyl]2,4,8,10-tetraoxaspiro[5,5]undecane, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, and pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate].

[0056] Examples of phosphorus-based antioxidants include triphenyl phosphite, diphenylalkyl phosphite, phenyldialkyl phosphite, tri(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, triphenyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, di(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, tristearyl sorbitol triphosphite, and tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenyl diphosphonate.

[0057] Examples of sulfur-based antioxidants include dilaurylthiopropionate, distearyldithiopropionate, and dibenzyl disulfide.

[0058] These antioxidants can be used individually or in combination of two or more. The amount of antioxidant added is 0.5 to 5 parts by mass, and particularly preferably 0.5 to 3 parts by mass, per 100 parts by mass of the prepolymer of component (A). If the amount of component (F) is above the lower limit, sufficient antioxidant effects such as improved heat resistance and prevention of discoloration can be obtained, and if the amount of component (F) is below the upper limit, sufficient curability and strength can be obtained without causing curing inhibition. Note that the antioxidant of component (F) may be mixed with the prepolymer of component (A).

[0059] <(G) Release Agent> The thermosetting epoxy-silicone hybrid resin composition for white reflectors of the present invention may further contain a release agent as component (G). The release agent in component (G) is added to improve release properties during molding.

[0060] Release agents include natural waxes such as carnauba wax and beeswax, as well as synthetic waxes such as acid waxes, polyethylene wax, glycerin derivatives, and fatty acid esters. However, many of these generally yellow easily or deteriorate over time under high temperature conditions or light irradiation, losing their release properties. Therefore, glycerin derivatives and fatty acid esters, which discolor less, and carnauba wax, which is initially colored but discolors less over time, are preferred.

[0061] The amount of component (G) is preferably 0.20 to 10.0% by mass, and more preferably 1.0 to 7.0% by mass, relative to the prepolymer of component (A). If the amount of component (G) is 0.20% by mass or more, sufficient release properties can be obtained. If the amount of component (G) is 10.0% by mass or less, there is no risk of poor seepage or poor adhesion.

[0062] <Other Additives> The resin composition of the present invention may further contain various additives as needed. For example, additives such as organopolysiloxane, silicone oil, thermoplastic resin, thermoplastic elastomer, organic synthetic rubber, or light stabilizer may be added to improve the properties of the resin, as long as they do not impair the effects of the present invention.

[0063] <Method for Producing the Composition> The following is an example of a method for producing the thermosetting epoxy-silicone hybrid resin composition for white reflectors of the present invention. First, organopolysiloxane, epoxy resin, and acid anhydride-based curing agent are heated and mixed until sufficiently homogeneous, then cooled to form a prepolymer. Next, the prepolymer, white pigment, inorganic filler, curing catalyst, antioxidant, and other additives as needed are blended in a predetermined composition ratio and thoroughly mixed homogeneously using a mixer or the like. Then, a melt-mixing treatment is performed using a hot roll, kneader, extruder, etc., followed by cooling and solidification, and then pulverized to an appropriate size to obtain a molding material for the thermosetting epoxy-silicone hybrid resin composition for white reflectors.

[0064] <Optical Semiconductor Device> Next, the optical semiconductor device of the present invention will be described. The optical semiconductor device of the present invention comprises a cured product of the above-mentioned thermosetting epoxy-silicone hybrid resin composition for white reflectors, and more specifically, comprises a reflector, case, etc. for an optical semiconductor element formed from the above-mentioned composition.

[0065] The most common molding methods for forming reflectors from the thermosetting epoxy-silicone hybrid resin composition for white reflectors of the present invention include transfer molding and compression molding. In the transfer molding method, a transfer molding machine is used, and the molding pressure is 5 to 20 N / mm. 2 In the molding method, it is preferable to perform molding at a molding temperature of 120 to 190°C and a molding time of 30 to 500 seconds, particularly at a molding temperature of 150 to 185°C and a molding time of 30 to 180 seconds. In the compression molding method, it is preferable to use a compression molding machine and perform molding at a molding temperature of 120 to 190°C and a molding time of 30 to 600 seconds, particularly at a molding temperature of 130 to 160°C and a molding time of 120 to 300 seconds. Furthermore, in any of the molding methods, post-curing may be performed at 150 to 185°C for 0.5 to 20 hours.

[0066] The thermosetting epoxy-silicone hybrid resin composition for white reflectors of the present invention exhibits excellent room-temperature bending properties, excellent initial reflectivity and heat resistance, and excellent adhesion to substrates plated with metals such as gold and silver, making it suitable for use as a reflector material in optoelectronic devices. Therefore, optoelectronic devices using this cured material as a reflector or the like will have excellent reliability.

[0067] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples. In the following, "parts" means parts by mass, and Me represents a methyl group. Furthermore, in the following formulas, the bonding order of each siloxane unit is not particularly limited.

[0068] The weight-average molecular weight (Mw) shown in the following examples and comparative examples was measured by gel permeation chromatography (GPC) using polystyrene as the standard substance. The measurement conditions are as follows: [GPC Measurement Conditions] Developing solvent: Tetrahydrofuran Flow rate: 0.6 mL / min Column: TSK Guardcolumn SuperH-L TSKgel SuperH4000 (6.0 mm I.D × 15 cm × 1) TSKgel SuperH3000 (6.0 mm I.D × 15 cm × 1) TSKgel SuperH2000 (6.0 mm I.D × 15 cm × 2) (All manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 20 μl (Sample concentration: 0.5 wt% - tetrahydrofuran solution) Detector: Differential refractometer (RI)

[0069] ((A-1) Synthesis of Organopolysiloxane) [Synthesis Example 1] Synthesis of Organopolysiloxane 1 397 g of phenyltrimethoxysilane, 165 g of (3-glycidoxy)propylmethyldimethoxysilane, 500 g of isopropyl alcohol, and 750 g of toluene were mixed and stirred. Then, 25 g of a 25% by mass aqueous solution of tetramethylammonium hydroxide and 182 g of water were added as catalysts and the mixture was reacted for 3 hours. After the reaction was complete, the mixture was neutralized with an aqueous solution of sodium dihydrogen phosphate, washed with hot water, and then the toluene was removed by distillation under reduced pressure to obtain linear organopolysiloxane 1 represented by the following average composition formula (6). The weight-average molecular weight of the obtained organopolysiloxane 1, measured by GPC, was 1,600 in polystyrene terms, and R in formula (1) 3 Of the corresponding groups, the proportion of monovalent aromatic hydrocarbon groups (phenyl groups) having 6 to 12 carbon atoms was 100 mol%, and the epoxy equivalent was 505 g / eq.

[0070] [Synthesis Example 2] Synthesis of organopolysiloxane 2: X'O-(Me2SiO) a 139 g of -X' (where X' is a hydrogen atom or a methyl group, and a is a number from 1 to 8, with an average of 3.5), 297 g of phenyltrimethoxysilane, 110 g of (3-glycidoxy)propylmethyldimethoxysilane, 500 g of isopropyl alcohol, and 900 g of toluene were mixed and stirred. Then, 24 g of a 25% by mass aqueous solution of tetramethylammonium hydroxide and 176 g of water were added as catalysts, and the mixture was reacted for 3 hours. After the reaction was complete, the mixture was neutralized with an aqueous solution of sodium dihydrogen phosphate, washed with hot water, and then the toluene was removed by distillation under reduced pressure to obtain linear organopolysiloxane 2 represented by the following average composition formula (7). The weight-average molecular weight of the obtained organopolysiloxane 2, measured by GPC, is 2,000 in polystyrene terms, and R in formula (1) 3 Of the corresponding groups, the proportion of monovalent aromatic hydrocarbon groups (phenyl groups) having 6 to 12 carbon atoms was 100 mol%, and the epoxy equivalent was 830 g / eq.

[0071] [Comparative Synthesis Example 1] Synthesis of organopolysiloxane 3 X'O-(Me2SiO) a 277 g of -X' (where X' is a hydrogen atom or a methyl group, and a is a number from 1 to 8, with an average of 3.5), 220 g of (3-glycidoxy)propylmethyldimethoxysilane, and 500 g of isopropyl alcohol were mixed and stirred. Then, 25 g of a 25% by mass aqueous solution of tetramethylammonium hydroxide and 180 g of water were added as catalysts, and the mixture was reacted for 3 hours. After the reaction was complete, 900 g of toluene was added and stirred, neutralized with an aqueous solution of sodium dihydrogen phosphate, washed with hot water, and then the toluene was removed by distillation under reduced pressure to obtain linear organopolysiloxane 3 represented by the following formula (8). The weight-average molecular weight of the obtained organopolysiloxane 3, measured by GPC, was 4,000 in polystyrene equivalents, and its epoxy equivalent was 414 g / eq.

[0072] ((A) Prepolymer Production) The prepolymer, which is component (A), was synthesized by blending components (A-1) to (A-3) in the composition and proportions shown in Table 1 below, and heating, melting, and mixing them under the reaction conditions shown in Table 1. The components (A-2) and (A-3) listed in Table 1 are as follows: (A-2) Epoxy resin having two or more epoxy groups in one molecule: 1,3,5-triglycidyl isocyanurate (TEPIC-S: trade name of Nissan Chemical Corporation, epoxy equivalent 100, melting point 100°C) (A-3) Acid anhydride-based curing agent: 4-methylhexahydrophthalic anhydride (manufactured by Shin Nippon Rika Co., Ltd., Ricacid MH)

[0073]

[0074] [Examples 1-6, Comparative Examples 1-9] Various components were blended according to the composition and formulation (parts by mass) shown in Table 2 below, and melt-mixed using a hot roll. The components listed in Table 2 are as follows: (B) Zinc cyanurate (Starfine F-10: manufactured by Nissan Chemical Corporation) (C) White pigment: Alumina, silica, polyol treated, rutile-type titanium dioxide with an average particle size of 0.2 μm (manufactured by Ishihara Sangyo Co., Ltd., CR-95) (D) Inorganic filler: Spherical fused silica with an average particle size of 10 μm (manufactured by Ryumori Co., Ltd., RS8225 / 53C) (E) Curing catalyst: Quaternary phosphonium salt (manufactured by Sunapro Co., Ltd., U-CAT5003) (F) Antioxidant Antioxidant 1: Phenolic antioxidant, compound name: Pentaerythritol tetrakis[3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate] (manufactured by ADEKA Corporation, ADEKA Stab AO-60) Antioxidant 2: Phosphorus-based antioxidant, compound name: Isodecyldiphenyl phosphite (manufactured by ADEKA Corporation, ADEKA Stab 135A) (G) Release agent: Carnauba wax (manufactured by Toa Chemical Co., Ltd., TOWAX-131) (H) Coupling agent: 3-Mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-803) (I) Adhesion aid: Triazole compound (manufactured by Nippon Carbide Industries Co., Ltd., ATA)

[0075] - Characterization of Compositions and Cured Products - The characteristics of the obtained compositions and their cured products were evaluated by the following method. The cured products were molded at a molding temperature of 175°C and a molding pressure of 6.9 N / mm². 2 The product was obtained by transfer molding under the condition of a molding time of 120 seconds, followed by curing at 180°C for 1 hour.

[0076] (1) Spiral flow value The spiral flow value was measured using test specimens molded by the above method using a mold conforming to the EMMI standard. The results are shown in Table 2.

[0077] (2) Bending strength and flexural modulus Test specimens were prepared using a mold conforming to JIS K6911:2006 standard and the method described above. The bending strength and flexural modulus of the obtained test specimens were measured at room temperature (25°C) in accordance with JIS K7171:2016 using an Autograph AG-IS (manufactured by Shimadzu Corporation). The results are shown in Table 2.

[0078] (3) Light reflectance (initial light reflectance, long-term heat resistance test) A disc-shaped cured material with a diameter of 50 mm and a thickness of 3 mm was prepared using the method described above. After that, secondary curing was performed at 175°C for 1 hour, and the initial light reflectance at 450 nm was measured using an X-rite 8200 manufactured by S.D.G. Co., Ltd. The cured material was then heat-treated at 180°C for 500 hours. The light reflectance of the cured material after heat treatment was measured using the same method. The results are shown in Table 2.

[0079] (4) Light transmittance A disc-shaped cured material with a diameter of 50 mm and a thickness of 0.2 mm was prepared using the method described above, and then secondary curing was performed at 175°C for 1 hour. The transmittance at 450 nm was measured using an X-rite 8200 manufactured by S.D.G. Corporation. The results are shown in Table 2.

[0080] (5) Glass transition temperature (Tg) A plate-shaped hardened material measuring 40 mm × 6 mm × 1 mm thick was prepared using the method described above, and the DMA (Dynamic Mechanical Analysis) was measured under the following conditions. The temperature at which the loss coefficient (tanδ = E'' / E'), which is expressed as the quotient of the obtained storage modulus (E') and loss modulus (E'') is maximized was determined, and this value was defined as Tg. <DMA measurement conditions> Model: Q800-1494-DMA Q-800 (manufactured by TA INSTRUMENT JAPAN Co., Ltd.) Measurement temperature: 25°C to 300°C Heating rate: 5°C / min Frequency: 1 Hz Measurement mode: Tensile vibration

[0081] (6) Adhesion test The epoxy resin composition was applied to a frame substrate made of a 20 mm x 20 mm copper frame that had been silver or gold plated, at a molding temperature of 175°C and a molding pressure of 6.9 N / mm. 2 The material was molded under conditions of a molding time of 90 seconds to prepare adhesive test specimens. Subsequently, secondary curing was performed at 150°C for 2 hours, and the adhesive strength at room temperature (25°C) was measured by flicking the adhesive test specimens at a speed of 0.2 mm / second using a universal bond tester (DAGE SERIES 4000: manufactured by DAGE).

[0082] (7) High temperature and high humidity reliability test The epoxy resin composition was molded on a frame substrate made of a 20 mm x 20 mm copper frame coated with silver at a molding temperature of 175°C and a molding pressure of 6.9 N / mm 2 Ten test pieces were prepared for bonding by molding under conditions of a molding time of 90 seconds. After secondary curing at 150°C for 2 hours, a moisture absorption treatment was performed under conditions of 85°C / 85%RH / 96 hours, followed by three IR reflow treatments at a peak temperature of 260°C. All 10 test pieces were evaluated as follows: [○] if there was no delamination, [△] if there were an average of 1 to 2 delaminations, and [×] if there were an average of 3 or more delaminations.

[0083] (8) Handling The workability of the composition after melting and mixing with a hot roll as described above was evaluated according to the following criteria. ○: Easily formed into tablets by cooling after melting and mixing. ×: Solidified by cooling after melting and mixing, but tack remained, or remained in a paste-like or semi-solid state even after cooling, making it difficult to form into tablets.

[0084]

[0085] As shown in Table 2, the resin compositions without zinc cyanurate (Comparative Examples 1-6) exhibited low adhesion to silver and gold plating, and peeling was confirmed in high-temperature, high-humidity reliability tests. Comparative Example 9, which contained a triazole compound as an adhesion aid, showed improvement in adhesion to silver and gold plating, but it was insufficient, and the reflectivity decreased after the heat resistance test. The resin composition of Comparative Example 5, in which the organopolysiloxane of component (A-1) does not have a phenyl group, and the resin compositions of Comparative Examples 6 and 7, which do not contain the epoxy resin of component (A-2), exhibited tackiness after melting and mixing with a hot roll and then cooling, making tableting difficult. The resulting cured products had excellent heat resistance, but low flexural strength and flexural modulus. The resin composition of Comparative Example 8, which does not contain the organopolysiloxane of component (A-1), showed excellent mechanical strength in the resulting cured product, but its heat resistance deteriorated. In contrast to these, the thermosetting epoxy-silicone hybrid resin composition for white reflectors of the present invention (Examples 1 to 6) exhibits a high Tg in its cured product, excellent bending properties at room temperature, excellent initial reflectivity and heat resistance, low light transmittance measured in thin cured products, high adhesion to silver and gold plating, and excellent performance in high-temperature and high-humidity reliability tests.

Claims

1. (A) Prepolymers which are reaction products of (A-1), (A-2), and (A-3) below, (A-1) the average composition formula (1) below (In the formula, R 1 R is independently a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, or a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms. 2 R is a monovalent aliphatic epoxy group having 4 to 30 carbon atoms. 3 R is a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, or a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, where 0 ≤ x < 0.4, 0.1 ≤ y ≤ 0.5, 0.4 ≤ z ≤ 0.8, and x + y + z = 1. The bonding order of each siloxane unit is not restricted. ) is represented as, and the total R in one molecule 3 (A-2) Organopolysiloxane having a proportion of 30 mol% to 100 mol% of monovalent aromatic hydrocarbon groups having 6 to 12 carbon atoms: 100 parts by mass (A-2) Epoxy resin having two or more epoxy groups in one molecule, one or more epoxy resins selected from the group consisting of triazine derivative epoxy resins, bisphenol type epoxy resins, hydrogenated bisphenol type epoxy resins, and alicyclic epoxy resins: 10 to 100 parts by mass (A-3) Acid anhydride curing agent: an amount such that the number of acid anhydride groups in component (A-3) is 0.3 to 1.0 for each epoxy group in component (A-1) and component (A-2) (B) Zinc cyanurate: 0.1 to 10 parts by mass per 100 parts by mass of the prepolymer of component (A), (C) White pigment: 3 to 350 parts by mass per 100 parts by mass of the prepolymer of component (A) (except for (B) zinc cyanurate), A thermosetting epoxy-silicone hybrid resin composition for white reflectors, comprising: (D) inorganic filler: 80 to 600 parts by mass per 100 parts by mass of the prepolymer of component (A) (excluding (B) zinc cyanurate and (C) white pigment); (E) curing catalyst: 0.05 to 5 parts by mass per 100 parts by mass of the prepolymer of component (A); and (F) antioxidant: 0.5 to 5 parts by mass per 100 parts by mass of the prepolymer of component (A).

2. In the formula (1), R 2 The thermosetting epoxy-silicone hybrid resin composition for a white reflector according to claim 1, wherein is a group represented by the following formula (2). (In the formula, R' is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R 4 is a divalent hydrocarbon group having 1 to 20 carbon atoms.) 3. The thermosetting epoxy-silicone hybrid resin composition for white reflectors according to claim 1, wherein the (A-2) component is a triazine derivative epoxy resin.

4. The thermosetting epoxy-silicone hybrid resin composition for a white reflector according to claim 1, wherein the white pigment of component (C) is titanium oxide whose surface is treated with alumina and then treated with one or more treatment agents selected from the group consisting of silica, alumina, zirconia, polyol and siloxane.

5. The thermosetting epoxy-silicone hybrid resin composition for white reflectors according to claim 1, wherein the (F) component is a combination of a phenolic antioxidant and a phosphorus-based antioxidant.

6. An optoelectronic device comprising a cured product of the thermosetting epoxy-silicone hybrid resin composition for white reflectors described in claim 1.

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