Curable silicone composition

Abstract

To provide a curable silicone composition that can provide a cured product having a low RI and high hardness and can be cured at low temperatures in a short time.SOLUTION: The curable silicone composition according to the present invention comprises: (A-1) a resinous organopolysiloxane that has an aryl-containing group content of 0 to less than 10 mol% and 2 or more Si-bonded alkenyl groups; (B-1) a resinous organohydrogen polysiloxane that has an aryl-containing group content of 10 mol % or more and that has 2 or more Si-bonded H's; and (C) a hydrosilylation reaction catalyst, wherein the amount of (A-2) a linear organopolysiloxane having 2 or more Si-bonded alkenyl groups in the composition is 0 to 3 mass% based on the total mass of all organopolysiloxane components in the composition, and (total numbers of moles of Si-bonded H's in the composition) / (total numbers of moles of Si-bonded alkenyl groups in the composition)>0.5.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a curable silicone composition, a cured product thereof, a reflective material for an optical semiconductor device made of the cured product, and an optical semiconductor device including the reflective material.

Background Art

[0002] It is known that a cured product of a curable silicone composition cured by a hydrosilylation reaction has various properties such as excellent heat resistance, low temperature resistance, electrical insulation, weather resistance, water repellency, and transparency. Therefore, various curable silicone compositions are widely used in various industries and are also used as optical materials.

[0003] For example, Patent Document 1 describes that a curable organopolysiloxane composition containing a methyl-based organopolysiloxane is used as a sealing material for an optical semiconductor element.

[0004] In Example 6 of Patent Document 2, 100 parts by mass of an average unit formula: (ViMe2SiO 2 / 2 , 2 / 2 , 0.58 , 0.36 , 0.06 , 104 , 1 / 2 , 4 / 2 , 1 / 2 ) 0.06 (Me3SiO 1 / 2 ) 0.36 (Si 4 / 2 ) 0.58 of a methyl-based silicone resin, 41.33 parts by mass of an average structural formula: (HMe2SiO 1 / 2 )2(Me2SiO 2 / 2 ) 104 (MePh2SiO 1 / 2 ) 4.3 (HSi 3 / 2 ) 4.3 of a branched organohydrogenpolysiloxane, 20 parts by mass of an average structural formula: (ViMe2SiO 1 / 2 )^{2}(Ph2SiO 2 / 2 )^{6}(Me2SiO 2 / 2 ) 104 of a silicone oil, and 13.8 parts by mass of a formula: (HMe2SiO 1 / 2 )^{4}(PhSiO 3 / 2 )^{2}of a branched organohydrogenpolysiloxane-containing addition-curable silicone composition are described.

[0005] Example 4 of Patent Document 3 contains 40g of chemical formula A:(ViMe2SiO 1 / 2 )(Me3SiO 1 / 2 )(Me2SiO 2 / 2 )4(SiO 4 / 2 )8 compounds, 60g, chemical formula B:(ViMe2SiO 1 / 2 )(Me3SiO 1 / 2 )4(Me2SiO 2 / 2 )(SiO 4 / 2 )5 compound, 20g, chemical formula E:(HMe2SiO 1 / 2 )2(Ph2SiO 2 / 2 ) compound, 2g, chemical formula G: (HMe2SiO 1 / 2 )3(PhSiO 3 / 2 ) compound, and 1g of chemical formula D:(ViMe2SiO 1 / 2 )2(Me3SiO 1 / 2 )2(EpSiO 3 / 2 ) 2.5 (SiO 4 / 2 A composition containing the compound ) is described.

[0006] Methyl organopolysiloxanes, such as those used in the above-mentioned patent documents, typically have a lower refractive index (RI) than phenyl organopolysiloxanes. For this reason, methyl organopolysiloxanes are promising candidate materials for matrix materials used as white reflectors in optical semiconductor devices.

[0007] However, methyl-based organopolysiloxanes are inferior to phenyl-based organopolysiloxanes in terms of hardness and toughness (crack resistance). Increasing the crosslinking density of methyl-based organopolysiloxanes to overcome this drawback increases the hardness of the cured product, but it may be too brittle for typical applications. Another way to increase the hardness of methyl-based organopolysiloxanes is to add reinforcing agents such as inorganic fillers. However, the addition of inorganic fillers usually causes a decrease in the optical properties of the cured product, a decrease in transmittance or reflectance, and an increase in the viscosity of the silicone composition. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2012-012433 [Patent Document 2] Japanese Patent Publication No. 2016-204423 [Patent Document 3] Japanese Patent Publication No. 2016-520679 [Overview of the project] [Problems that the invention aims to solve]

[0009] An object of the present invention is to provide a cured product having a low RI and high hardness, and a curable silicone composition that can be cured at low temperatures and in a short time. A further object of the present invention is to provide a cured product having a low RI, high hardness, and high reflectivity, and a curable silicone composition that can be cured at low temperatures and in a short time. Furthermore, an object of the present invention is to provide a reflective material for an optical semiconductor device made from a cured product of the composition, and an optical semiconductor device equipped with the reflective material for the optical semiconductor device. [Means for solving the problem]

[0010] To solve the above problems, the present invention provides the following curable silicone composition. A curable silicone composition, (A-1) Equality unit formula: (R 1 R 2 2SiO 1 / 2 ) a (R 2 3SiO 1 / 2 ) b (SiO 4 / 2 ) c (XO 1 / 2 ) d (In the formula, R 1 It is an alkenyl group, R 2It is a monovalent hydrocarbon group that does not have an aliphatic unsaturated carbon bond, The amount of aryl-containing groups bonded to silicon atoms is 0 mol% or more and less than 10 mol%, based on the total number of moles of all organic groups bonded to silicon atoms. X is a hydrogen atom or an alkyl group, a, b, c, and d represent the molar ratio of their respective units, and 0 <a≦0.7、0<b≦0.8、0<c≦0.7、0≦d≦0.2、a+b+c=1.0である) Represented as such, a resinous organopolysiloxane having at least two alkenyl groups bonded to a silicon atom in one molecule, (B-1) A resinous organohydrogenpolysiloxane having an amount of aryl-containing groups bonded to silicon atoms of 10 mol% or more based on the total number of moles of all organic groups bonded to silicon atoms, and having at least two hydrogen atoms bonded to silicon atoms in one molecule, but without alkenyl groups bonded to silicon atoms, and (C) Catalyst for hydrosilylation reaction Includes, The amount of linear organopolysiloxane having at least two alkenyl groups bonded to (A-2) silicon atoms in the composition is 0 to 3% by mass, based on the total mass of all organopolysiloxane components contained in the composition. (Total number of moles of hydrogen atoms bonded to silicon atoms in the composition) / (Total number of moles of alkenyl groups bonded to silicon atoms in the composition) > 0.5 A curable silicone composition. The present invention provides a cured product of the above-mentioned curable silicone composition. The present invention provides a reflective material for optical semiconductor devices made of the above-mentioned cured product. The present invention provides an optoelectronic semiconductor device comprising the above-mentioned reflective material for optoelectronic semiconductor devices. [Effects of the Invention]

[0011] A curable silicone composition according to one embodiment of the present invention can be cured at low temperatures and in a short time, and the cured product has the effect of having a low RI and high hardness. A curable silicone composition according to another embodiment of the present invention can be cured at low temperatures and in a short time, and the cured product has the effect of having a low RI, high hardness, and high reflectivity. [Modes for carrying out the invention]

[0012] [(A-1) Component: A resinous organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in each molecule] Component (A-1) is a resinous organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule, represented by the following average unit formula. (R 1 R 2 2SiO 1 / 2 ) a (R 2 3SiO 1 / 2 ) b (SiO 4 / 2 ) c (XO 1 / 2 ) d In the formula, R 1 is an alkenyl group, and R 2 is a monovalent hydrocarbon group that does not have an aliphatic unsaturated carbon bond, and the amount of aryl-containing group bonded to the silicon atom is 0 mol% or more and less than 10 mol% based on the total number of moles of all organic groups bonded to the silicon atom, X is a hydrogen atom or an alkyl group, and a, b, c and d represent the molar ratio of their respective units, 0 <a≦0.7、0<b≦0.8、0<c<0.7、0≦d≦0.2、a+b+c=1.0である。 The curable silicone composition of the present invention may contain one (A-1) component or two or more (A-1) components.

[0013] In this specification, "resin-like organopolysiloxane" refers to a molecular structure containing T units (RSiO 3 / 2 )(wherein R is a monovalent hydrocarbon group or a hydrogen atom) and Q unit (SiO4 / 2 This refers to an organopolysiloxane containing at least one unit selected from ). Resinous organopolysiloxanes may have a branched chain structure, a three-dimensional network structure, or a combination thereof.

[0014] In this specification, "aryl-containing group" means an aryl group, a hydrocarbon group having an aryl group in part, or a group in which some or all of the hydrogen atoms of the aryl group and the hydrocarbon group are substituted with halogen atoms such as fluorine, chlorine, or bromine atoms. In this specification, "aryl-containing group bonded to a silicon atom" means the "aryl-containing group" that is directly bonded to a silicon atom. Examples of aryl-containing groups include aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, 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, chlorine, or bromine atoms.

[0015] In this specification, "organic group" means a group containing at least one carbon atom. Furthermore, "organic group bonded to a silicon atom" means an organic group that is directly bonded to a silicon atom without the need for a siloxane bond (-O-Si-).

[0016] (A-1) R in the average unit formula of component 1 Examples of alkenyl groups include alkenyl groups having 2 to 12 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl groups, as well as groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine, chlorine, or bromine. Alkenyl groups having 2 to 6 carbon atoms are preferred, and vinyl groups are particularly preferred.

[0017] (A-1) R in the average unit formula of component 2Examples of monovalent hydrocarbon groups that do not have aliphatic unsaturated carbon bonds include alkyl groups with 1 to 12 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups with 6 to 20 carbon atoms such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups with 7 to 20 carbon atoms such as benzyl, phenethyl, 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, chlorine, or bromine. 2 Preferably, is a monovalent hydrocarbon group having 1 to 6 carbon atoms and not having an aliphatic unsaturated carbon bond, more preferably an alkyl group having 1 to 6 carbon atoms, and particularly preferably a methyl group. In one embodiment, R 2 This refers to a monovalent hydrocarbon group other than an aryl-containing group.

[0018] In component (A-1), the amount of aryl-containing groups bonded to silicon atoms is 0 mol% or more and less than 10 mol% based on the total number of moles of all organic groups bonded to silicon atoms. That is, in component (A-1), there are no aryl-containing groups bonded to silicon atoms, or if there are aryl-containing groups bonded to silicon atoms, the amount of aryl-containing groups bonded to silicon atoms is less than 10 mol% of the total number of organic groups bonded to silicon atoms. In the above average unit formula, R in component (A-1) 1 and R 2All of them correspond to all-organic groups bonded to silicon atoms. The amount of aryl groups bonded to silicon atoms in the component (A-1) is 0 mol% or more and less than 10 mol%, preferably 0 mol% or more and 5 mol% or less, more preferably 0 mol% or more and 1 mol% or less, and even more preferably 0 mol%, based on the total number of moles of all-organic groups bonded to silicon atoms. In the component (A-1), when the amount of aryl-containing groups bonded to silicon atoms is 0 mol% or more and less than 10 mol% based on the total number of moles of all-organic groups bonded to silicon atoms, the cured product formed from the curable silicone composition can have a low refractive index (RI).

[0019] In the average unit formula of the component (A-1), X is a hydrogen atom or an alkyl group. As the alkyl group of X, an alkyl group having 1 to 3 carbon atoms is preferable, and specifically, a methyl group, an ethyl group, and a propyl group are exemplified.

[0020] In the average unit formula of the component (A-1), a is in the range of 0 < a ≤ 0.7, preferably in the range of 0.01 ≤ a ≤ 0.7, more preferably in the range of 0.05 ≤ a ≤ 0.6, and even more preferably in the range of 0.1 ≤ a ≤ 0.5. b is in the range of 0 < b ≤ 0.8, preferably in the range of 0.01 ≤ b ≤ 0.6, more preferably in the range of 0.05 ≤ b ≤ 0.5, and even more preferably in the range of 0.1 ≤ b ≤ 0.4. c is in the range of 0 < c < 0.7, preferably in the range of 0.2 ≤ c ≤ 0.6, more preferably in the range of 0.3 ≤ c ≤ 0.5, and even more preferably in the range of 0.35 ≤ c ≤ 0.45. d is in the range of 0 ≤ d ≤ 0.2, preferably in the range of 0 ≤ d ≤ 0.15, more preferably in the range of 0 ≤ d ≤ 0.1, and even more preferably in the range of 0 ≤ d ≤ 0.05.

[0021] In one embodiment of the present invention, the amount of component (A-1) contained in the curable silicone composition is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 60% by mass or less, and particularly more preferably 50% by mass or less, based on the total mass of all organopolysiloxane components contained in the composition.

[0022] In one embodiment of the present invention, component (A-1) has a molecular weight of 500 or more. The weight-average molecular weight (Mw) of component (A-1) is not particularly limited, but is preferably 1000 or more, more preferably 1500 or more, even more preferably 2000 or more, and preferably 100000 or less, more preferably 70000 or less, and even more preferably 50000 or less. In this specification, the weight-average molecular weight (Mw) is the value converted to standard polystyrene measured by gel permeation chromatography (GPC).

[0023] [(A-2) Component: A linear organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in each molecule] In the curable silicone composition of the present invention, the amount of linear organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule is 0 to 3% by mass, based on the total mass of all organopolysiloxane components contained in the composition. That is, in the curable silicone composition of the present invention, component (A-2) is an optional component and may or may not be included in the composition. However, if component (A-2) is included in the composition, the amount of component (A-2) must be 3% by mass or less, based on the total mass of all organopolysiloxane components contained in the composition. In this specification, "all organopolysiloxane components contained in the composition" is not particularly limited as long as it is an organopolysiloxane, and may include, for example, organopolysiloxanes containing alkenyl groups which may be linear or resinous, organohydrogenpolysiloxanes which may be linear or resinous, and other organopolysiloxanes, such as organopolysiloxanes which do not contain silicon-bonded hydrogen atoms and silicon-bonded alkenyl groups. The curable silicone composition may contain only one (A-2) component or may contain two or more (A-2) components.

[0024] Component (A-2) has an alkenyl group bonded to at least two silicon atoms, in addition to a monovalent hydrocarbon group that does not have an aliphatic unsaturated carbon bond bonded to a silicon atom. Examples of alkenyl groups in component (A-2) include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, a nonenyl group, a decenyl group, an undecenyl group, and a dodecenyl group, with alkenyl groups having 2 to 6 carbon atoms being preferred, and a vinyl group being particularly preferred.

[0025] Examples of monovalent hydrocarbon groups in component (A-2) that do not have aliphatic unsaturated carbon bonds include alkyl groups with 1 to 12 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups with 6 to 20 carbon atoms such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups with 7 to 20 carbon atoms such as benzyl, phenethyl, 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, chlorine, or bromine. The monovalent hydrocarbon group in component (A-2) that does not have an aliphatic unsaturated carbon bond is preferably a monovalent hydrocarbon group having 1 to 6 carbon atoms that does not have an aliphatic unsaturated carbon bond, more preferably an alkyl group having 1 to 6 carbon atoms, and particularly preferably a methyl group. In one embodiment, the monovalent hydrocarbon group in component (A-2) is not an aryl-containing group.

[0026] Component (A-2) has an alkenyl group bonded to a silicon atom at the end of the organopolysiloxane molecule (i.e., (R 3 SiO 1 / 2 (R is a monovalent hydrocarbon group) may only be present in the unit (M unit), or in the diorganosiloxane repeating unit of the molecule (i.e., (R 2 SiO 2 / 2 The R group may be present only in the unit (D unit), where R is a monovalent hydrocarbon group, or it may be present at both the molecular terminus (M unit) and the diorganosiloxane repeating unit (D unit).

[0027] The (A-2) component can be expressed by the following general formula: R 3 3SiO(R 3 2SiO) n SiR 3 3 In the formula, R 3 It is a monovalent hydrocarbon group and has at least two R 3 is an alkenyl group, and n is an integer greater than or equal to 5.

[0028] In the above formula, R 3 Examples of the monovalent hydrocarbon group of include alkyl groups having 1 to 12 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, and dodecyl group; aryl groups having 6 to 20 carbon atoms such as phenyl group, tolyl group, xylyl group, and naphthyl group; aralkyl groups having 7 to 20 carbon atoms such as benzyl group, phenethyl group, and phenylpropyl group; alkenyl groups having 2 to 12 carbon atoms such as vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, and dodecenyl group; and groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine atom, chlorine atom, and bromine atom. R 3 is preferably a monovalent hydrocarbon group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and particularly preferably a methyl group. Further, in one embodiment, R 3 is a monovalent hydrocarbon group other than an aryl-containing group.

[0029] In the above formula, R 3 Examples of at least two alkenyl groups of include alkenyl groups having 2 to 12 carbon atoms such as vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, and dodecenyl group. An alkenyl group having 2 to 6 carbon atoms is preferable, and a vinyl group is particularly preferable.

[0030] In one embodiment of the present invention, the component (A-2) may be a linear alkenyl group-containing organopolysiloxane having a molecular chain both-end alkenyl group-blocking structure represented by the following general formula. R 4 R 5 2SiO(R 5 2SiO) n SiR 4 R 5 2 In the formula, R 4 is an alkenyl group, and R 5 are each independently a monovalent hydrocarbon group having no aliphatic unsaturated carbon bond, and n is an integer of 5 or more.

[0031] In the above formula, R 4 is an alkenyl group. Examples of this alkenyl group include alkenyl groups having 2 to 12 carbon atoms such as vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, and dodecenyl group. Alkenyl groups having 2 to 6 carbon atoms are preferred, and particularly preferably, it is a vinyl group.

[0032] In the above formula, R 5 is a monovalent hydrocarbon group having no aliphatic unsaturated carbon bond. Examples of R 5 include alkyl groups having 1 to 12 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, and dodecyl group; aryl groups having 6 to 20 carbon atoms such as phenyl group, tolyl group, xylyl group, and naphthyl group; aralkyl groups having 7 to 20 carbon atoms such as benzyl group, phenethyl group, and phenylpropyl group; and groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine atom, chlorine atom, and bromine atom. R 5 is preferably a monovalent hydrocarbon group having no aliphatic unsaturated carbon bond with 1 to 6 carbon atoms, more preferably an alkyl group with 1 to 6 carbon atoms, and particularly preferably a methyl group. Also, in one embodiment, R 5 is a monovalent hydrocarbon group other than an aryl-containing group.

[0033] In the above formula, n is 5 or greater, preferably 10 or greater, more preferably 20 or greater, and even more preferably 30 or greater. In one embodiment, n is 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less.

[0034] In one embodiment, component (A-2) has a molecular weight of 500 or more. The weight-average molecular weight (Mw) of component (A-2) is not particularly limited, but is preferably 1,000 or more, more preferably 2,000 or more, and even more preferably 3,000 or more. In one embodiment, the weight-average molecular weight (Mw) of component (A-2) is 200,000 or less, preferably 160,000 or less, and more preferably 120,000 or less.

[0035] [(A-3) Component: A silane or siloxane compound having at least two alkenyl groups bonded to a silicon atom in one molecule and having a molecular weight of less than 500] In one embodiment of the present invention, the curable silicone composition may contain component (A-3), i.e., a silane compound or siloxane compound having at least two alkenyl groups bonded to silicon atoms in one molecule and having a molecular weight of less than 500. For example, component (A-3) may be: (ViMe2SiO 1 / 2 )4(SiO 4 / 2 ), formula: (ViMeSiO 2 / 2 )4 or formula:(ViMe2SiO 1 / 2 )3(PhSiO 3 / 2 Examples of compounds having the following characteristics:

[0036] When component (A-3) is included in the curable silicone composition, the amount of component (A-3) in the composition is preferably such that [mass of component (A-1) / (mass of component (A-3) + mass of component (A-1)] is 0.3 or more and 1 or less, more preferably 0.4 or more and 0.9 or less, and even more preferably 0.5 or more and 0.8 or less.

[0037] [(B-1) Ingredient: Resin-like organohydrogen polysiloxane] The curable silicone composition of the present invention contains a resinous organohydrogenpolysiloxane in which the amount of aryl-containing groups bonded to silicon atoms is 10 mol% or more based on the total number of moles of all organic groups bonded to silicon atoms, and which has at least two hydrogen atoms bonded to silicon atoms in one molecule, but does not have alkenyl groups bonded to silicon atoms. Component (B-1) functions as a crosslinking agent in the curable silicone composition. The curable silicone composition may contain only one type of (B-1) component, or it may contain two or more types of (B-1) components. Component (B-1) may have a branched or three-dimensional network structure. In component (B-1), the amount of aryl-containing groups bonded to silicon atoms is 10 mol% or more, preferably 15 mol% or more, and more preferably 18 mol% or more, based on the total number of moles of all organic groups bonded to silicon atoms.

[0038] Component (B-1) does not have an alkenyl group bonded to a silicon atom. Examples of groups bonded to silicon atoms other than hydrogen atoms in component (B-1) include monovalent hydrocarbon groups that do not have aliphatic unsaturated carbon bonds. Specifically, examples include alkyl groups with 1 to 12 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups with 6 to 20 carbon atoms such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups with 7 to 20 carbon atoms such as benzyl, phenethyl, 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, chlorine, or bromine. Furthermore, the silicon atoms in component (B-1) may have small amounts of alkoxy groups such as hydroxyl groups, methoxy groups, or ethoxy groups attached to them, as long as this does not impair the purpose of the present invention.

[0039] In one embodiment of the present invention, component (B-1) is a resinous organohydrogenpolysiloxane represented by the following average unit formula. (R 6 3SiO 1 / 2 ) u (R 6 2SiO 2 / 2 ) v (R 6 SiO 3 / 2 ) w (SiO 4 / 2 ) x (XO 1 / 2 ) y In the formula, each R 6 R are monovalent hydrocarbon groups or hydrogen atoms that do not have aliphatic unsaturated carbon bonds, which may be the same or different from each other, provided that there are at least two R in one molecule. 6 is a hydrogen atom, the amount of aryl-containing groups bonded to the silicon atom is 10 mol% or more based on the total number of moles of all organic groups bonded to the silicon atom, X is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and u, v, w, x, and y represent the molar ratio of their respective units, where 0 ≤ u ≤ 0.8, 0 ≤ v ≤ 0.6, 0 ≤ w ≤ 0.8, 0 ≤ x ≤ 0.9, 0 ≤ y ≤ 0.10, where w + x > 0 and u + v + w + x + y = 1. In the above formula, preferably 0.1 ≤ u ≤ 0.8, 0 ≤ v ≤ 0.5, 0 ≤ w ≤ 0.8, 0 ≤ x ≤ 0.8, 0 ≤ y ≤ 0.1, 0.1 ≤ w + x ≤ 0.8 and u + v + w + x + y = 1. More preferably, 0.2 ≤ w + x ≤ 0.6, even more preferably, w + x is 0.3 or greater, and particularly preferably 0.35 or greater.

[0040] R 6Examples of monovalent hydrocarbon groups include C1-C12 alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; C6-C12 aryl groups such as phenyl, tolyl, xylyl, and naphthyl groups; C7-C12 aralkyl groups such as benzyl, phenethyl, 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, chlorine, or bromine atoms, such as halogen-substituted C1-C12 alkyl groups like 3-chloropropyl and 3,3,3-trifluoropropyl. 6 The monovalent hydrocarbon group is preferably a methyl group and a phenyl group. X is preferably a hydrogen atom, a methyl group, or an ethyl group.

[0041] In one embodiment of the present invention, component (B-1) may be a resinous organohydrogenpolysiloxane represented by the following average unit formula. (R 6 3SiO 1 / 2 ) u1 (R 6 2SiO 2 / 2 ) v1 (R 6' SiO 3 / 2 ) w1 In the formula, R 6 Each of these is independently a monovalent hydrocarbon group or hydrogen atom that does not have the aliphatic unsaturated carbon bond described above, and at least two R 6 is a hydrogen atom, and R 6' R is a monovalent hydrocarbon group that does not have an aliphatic unsaturated carbon bond, and the amount of aryl-containing group bonded to the silicon atom is 10 mol% or more based on the total number of moles of all organic groups bonded to the silicon atom, and u1, v1, and w1 represent the molar ratio of their respective units, and are numbers that satisfy 0.1 ≤ u1 ≤ 0.8, 0 ≤ v1 ≤ 0.5, 0.1 ≤ w1 ≤ 0.8 and u1 + v1 + w1 = 1. 6' As for monovalent hydrocarbon groups that do not have an aliphatic unsaturated carbon bond, R6 Examples of monovalent hydrocarbon groups include those exemplified above. In one embodiment, in the above average unit formula, v1=0. In one embodiment, in the above average unit formula, v1=0, and R 6 is an alkyl group or a hydrogen atom, preferably a methyl group or a hydrogen atom, R 6' This is an aryl group, preferably a phenyl group.

[0042] In one embodiment of the present invention, component (B-1) is expressed by the following average unit formula. (R 6 3SiO 1 / 2 ) u2 (SiO 4 / 2 ) x2 In the formula, R 6 is the monovalent hydrocarbon group or hydrogen atom mentioned above, and at least two R 6 x² is a hydrogen atom, the amount of aryl-containing groups bonded to the silicon atom is 10 mol% or more based on the total number of moles of all organic groups bonded to the silicon atom, u² and x² represent the molar ratio of their respective units, u² + x² = 1, preferably 0.1 ≤ u² ≤ 0.8 and 0.2 ≤ x² ≤ 0.9, and more preferably 0.5 ≤ u² ≤ 0.7 and 0.3 ≤ x² ≤ 0.5.

[0043] In one embodiment of the present invention, the amount of component (B-1) contained in the curable silicone composition is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 25% by mass or less, based on the total mass of all organopolysiloxane components contained in the composition.

[0044] The weight-average molecular weight (Mw) of component (B-1) is not particularly limited, but is preferably 300 or more, more preferably 500 or more, even more preferably 1000 or more, and preferably 100000 or less, more preferably 50000 or less, and even more preferably 30000 or less.

[0045] [(B-2) Ingredient: Linear organohydrogenpolysiloxane] In one embodiment of the present invention, the curable silicone composition may contain component (B-2), that is, a linear organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in one molecule, but without alkenyl groups bonded to silicon atoms. Component (B-2) functions as a crosslinking agent in the curable silicone composition. The curable silicone composition may contain only one type of component (B-2), or it may contain two or more types of components (B-2).

[0046] Component (B-2) does not have an alkenyl group bonded to the silicon atom. Component (B-2) has a monovalent hydrocarbon group that does not have an aliphatic unsaturated carbon bond, in addition to a hydrogen atom bonded to the silicon atom. In one embodiment of the present invention, component (B-2) may have an aryl-containing group bonded to the silicon atom as the monovalent hydrocarbon group. The amount of the aryl-containing group bonded to the silicon atom is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 15 mol% or more, based on the total number of moles of all organic groups bonded to the silicon atom.

[0047] Examples of monovalent hydrocarbon groups in component (B-2) that do not have aliphatic unsaturated carbon bonds include alkyl groups with 1 to 12 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups with 6 to 20 carbon atoms such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups with 7 to 20 carbon atoms such as benzyl, phenethyl, 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, chlorine, or bromine. The monovalent hydrocarbon group in component (B-2) that does not have an aliphatic unsaturated carbon bond is preferably a monovalent hydrocarbon group having 1 to 6 carbon atoms that does not have an aliphatic unsaturated carbon bond, more preferably one or more alkyl groups having 1 to 6 carbon atoms and a phenyl group, and even more preferably a methyl group and a phenyl group.

[0048] (B-2) Component (B-2) has hydrogen atoms bonded to silicon atoms at the ends of organopolysiloxane molecules (i.e., (R 3 SiO 1 / 2 (R) may be present only in the unit (M unit), where R is a monovalent hydrocarbon group or a hydrogen atom, or in the diorganosiloxane repeating unit of the molecule (i.e., (R) 2 SiO 2 / 2 The R may be present only in the unit (D unit), where R is a monovalent hydrocarbon group or a hydrogen atom, or it may be present at both the molecular terminus (M unit) and the diorganosiloxane repeating unit (D unit).

[0049] The (B-2) component can be expressed by the following general formula: R 7 3SiO(R 7 2SiO) n SiR 7 3 In the formula, R 7 is a monovalent hydrocarbon group that does not have an aliphatic unsaturated carbon bond, or a hydrogen atom, and has at least two R 7R is a hydrogen atom, and n is an integer greater than or equal to 1. In the above formula, R 7 It can be an aryl-containing group.

[0050] In the above formula, R 7 Examples of monovalent hydrocarbon groups include alkyl groups with 1 to 12 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups with 6 to 20 carbon atoms such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups with 7 to 20 carbon atoms such as benzyl, phenethyl, 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, chlorine, or bromine. 7 The monovalent hydrocarbon group is preferably methyl and phenyl.

[0051] In one embodiment of the present invention, component (B-2) may be a linear organohydrogenpolysiloxane having an aryl-containing group bonded to a silicon atom and hydrogen atoms bonded to silicon atoms at both ends of the molecular chain, represented by the following general formula. R 8 R 9 2SiO(R 9' 2SiO) n SiR 8 R 9 2 In the formula, R 8 R is a hydrogen atom, 9 and R 9’ Each of these is independently a monovalent hydrocarbon group that does not have an aliphatic unsaturated carbon bond, and n is an integer of 1 or more. In the above formula, R 9 and R 9’ Each of these can be an aryl-containing group independently. The amount of aryl-containing groups bonded to the silicon atom is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 15 mol% or more, based on the total number of moles of all organic groups bonded to the silicon atom.

[0052] In the above formula, R 9 and R 9’ Examples include alkyl groups with 1 to 12 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups with 6 to 20 carbon atoms such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups with 7 to 20 carbon atoms such as benzyl, phenethyl, 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, chlorine, or bromine. 9 and R 9’ Preferably, is a monovalent hydrocarbon group having 1 to 6 carbon atoms and not having an aliphatic unsaturated carbon bond, more preferably an alkyl group or phenyl group having 1 to 6 carbon atoms. More preferably, R 9 and R 9’ R is selected from the group consisting of methyl and phenyl. In one embodiment, R 9 is an alkyl group, preferably a methyl group, and R 9’ This can be an aryl group, preferably a phenyl group.

[0053] In the above formula, n is 2000 or less, more preferably 1500 or less, and even more preferably 1000 or less.

[0054] When component (B-2) is included in the curable silicone composition, the amount of component (B-2) in the composition is preferably such that [mass of component (B-1) / (mass of component (B-2) + mass of component (B-1)] is 0.1 or more and 1 or less, more preferably 0.2 or more and 0.9 or less, and even more preferably 0.5 or more and 0.8 or less.

[0055] The weight-average molecular weight (Mw) of component (B-2) is not particularly limited, but is preferably 300 or more, more preferably 500 or more, and preferably 200,000 or less, more preferably 150,000 or less, and even more preferably 100,000 or less.

[0056] In the curable silicone composition of the present invention, the amount is such that [(total number of moles of hydrogen atoms bonded to silicon atoms in the composition) / (total number of moles of alkenyl groups bonded to silicon atoms in the composition)] > 0.5. In this specification, the above formula may also be referred to as [hydrogen / alkenyl group]. The value of [hydrogen / alkenyl group] is preferably greater than 0.5 and 1.5 or less, more preferably 0.7 or more and 1.5 or less, and even more preferably 0.7 or more and 1.2 or less. By setting the value of hydrogen / alkenyl group to greater than 0.5, the hardness of the cured product is increased.

[0057] The amount of alkenyl groups in the components of the curable silicone composition of the present invention can be accurately quantified by a titration method commonly known as the Wies process. The principle is described below.

[0058] First, the alkenyl group in the silicone raw material is subjected to an addition reaction with iodine monochloride as shown in formula (1). Equation (1) CH2=CH- + 2ICl → CH2I-CHCl- + ICl (excess) Next, the excess iodine monochloride is reacted with potassium iodide in the reaction shown in equation (2) to release iodine. Formula (2) ICl+KI → I2+ KCl Next, the liberated iodine is titrated with sodium thiosulfate solution. The concentration of alkenyl groups (mol%) in the component can be quantified from the difference between the amount of sodium thiosulfate required for titration and the titration volume of a separately prepared blank solution. To determine the mass percentage, multiply the mol% by the formula weight (in the case of a vinyl group, the formula weight is 27 because CH2=CH-).

[0059] [(C) Component: Catalyst for hydrosilylation reaction] The curable silicone composition of the present invention contains component (C), i.e., a catalyst for the hydrosilylation reaction. The curable silicone composition may contain only one type of component (C), or it may contain two or more types of components (C). Component (C) is a component used as a catalyst to promote the addition reaction (i.e., hydrosilylation reaction) between an alkenyl group bonded to the silicon atom of an organopolysiloxane and a hydrogen atom bonded to the silicon atom of an organohydrogenpolysiloxane. Examples of such components (C) include platinum-based catalysts such as chloroplatinic acid, an alcoholic solution of chloroplatinic acid, a complex of platinum and an olefin, a complex of platinum and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, and platinum-supported powders; palladium-based catalysts such as tetrakis(triphenylphosphine)palladium, palladium black, and a mixture with triphenylphosphine; and rhodium-based catalysts. Platinum-based catalysts are particularly preferred.

[0060] The amount of component (C) is the amount of catalyst necessary for curing the components contained in the curable silicone composition and is not particularly limited. For example, when a platinum-based catalyst is used as component (C), the amount of platinum metal contained in this platinum-based catalyst is practically preferably in the range of 0.01 to 1000 ppm by weight in the curable silicone composition, and particularly preferably in the range of 0.1 to 500 ppm.

[0061] [(D) Ingredient: Hydrosilylation reaction inhibitor] In one embodiment, the curable silicone composition of the present invention may contain, as an optional component, component (D), i.e., a hydrosilylation reaction inhibitor. Component (D), the hydrosilylation reaction inhibitor, is a component for suppressing the hydrosilylation reaction of the silicone composition. Specific examples of component (D) include silylated acetylene compounds such as methyltris(3-methyl-1-butyne-3-oxy)silane, methylvinylbis(3-methyl-1-butyne-3-oxy)silane, and trimethyl(cyclohexyl-1-ethyn-1-oxy)silane; alkyne alcohols such as 1-ethynylcyclohexanol, 2-methyl-3-butyne-2-ol, 3,5-dimethyl-1-hexyne-3-ol, and 2-phenyl-3-butyne-2-ol; enyne compounds such as 3-methyl-3-penten-1-yine and 3,5-dimethyl-3-hexen-1-yine; alkenyl cyclic siloxane compounds such as 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane and 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane; and benzotriazole. The content of component (D) in the curable silicone composition is not limited, but is usually 0.001 to 5% by mass of the total curable silicone composition.

[0062] [(E) Ingredient: White pigment] In one embodiment, the curable silicone composition of the present invention may contain component (E), i.e., a white pigment. Examples of component (E) (white pigment) include metal oxides such as titanium dioxide, aluminum oxide, zinc oxide, zirconium oxide, and magnesium oxide, hollow fillers such as glass balloons and glass beads, and others such as barium sulfate, zinc sulfate, barium titanate, aluminum nitride, boron nitride, and antimony oxide. Titanium dioxide is preferred due to its high light reflectance and opacity. Aluminum oxide, zinc oxide, and barium titanate are also preferred due to their high light reflectance in the UV region. The curable silicone composition may contain only one type of component (E), or it may contain two or more types of components (E). In one embodiment of the present invention, when the curable silicone composition contains component (E), it can exhibit a light reflectance of 91% or more, preferably 93% or more, under the conditions shown in the example (cured product thickness of 30 μm, light with a wavelength of 450 nm).

[0063] Component (E) may be a surface-treated white pigment for the purpose of increasing reflectivity, whiteness, and lightfastness. Known surface treatments include treatment with aluminum oxide, aluminum hydroxide, silica, zinc oxide, zirconium oxide, organic compounds, and siloxanes. Organic compounds are not particularly limited, but include polyhydric alcohols, alkanolamines or their derivatives, organosilicon compounds such as organosiloxanes, higher fatty acids or their metal salts, and organometallic compounds. The surface treatment method is not particularly limited as long as it is a known method, and can be used, for example, (1) a method of mixing a pre-surface-treated white pigment into the silicone composition, or (2) a method of adding a surface treatment agent separately to the silicone composition and reacting it with the white pigment in the composition.

[0064] The surface treatment of component (E) is not particularly limited as long as it is of a known type, but a silica-free treatment is particularly preferred because it provides particularly excellent light resistance to the resulting white cured product. Furthermore, a treatment that does not contain organic matter is particularly preferred because it can maintain a high reflectivity after the heat resistance test of the resulting white cured product. The surface treatment of the white pigment can be analyzed using analytical methods such as energy-dispersive X-ray spectroscopy (SEM-EDX) or inductively coupled plasma mass spectrometry (ICP-MS).

[0065] The average particle size and shape of component (E) are not limited, but the average particle size is preferably in the range of 0.05 to 10 μm, and particularly preferably in the range of 0.1 to 2 μm. In this specification, the average particle size refers to the particle size at 50% of the integrated value of the particle size distribution determined by the laser diffraction-scattering method.

[0066] In the curable silicone composition of the present invention, component (E) is an optional component, and its content when component (E) is included in the composition is not particularly limited. When the curable silicone composition contains component (E), the amount of component (E) in the curable silicone composition is preferably 50 parts by mass or more, more preferably 75 parts by mass or more, and even more preferably 100 parts by mass or more, based on 100 parts by mass of the total organopolysiloxane components included in the composition. This is because when the content of component (E) is above the lower limit mentioned above, the light reflectivity of the resulting cured product is good. In a preferred embodiment, the amount of component (E) in the curable silicone composition is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and even more preferably 120 parts by mass or less, based on 100 parts by mass of the total organopolysiloxane components included in the composition.

[0067] The curable silicone composition of the present invention may contain optional components other than those described above, as long as they do not impair the objectives of the present invention. Examples of such optional components include acetylene compounds, organophosphorus compounds, vinyl group-containing siloxane compounds, inorganic fillers other than white pigments, or inorganic fillers obtained by hydrophobically treating the surface of an inorganic filler with an organosilicon compound, powder surface treatment agents or surfactants, organopolysiloxanes that do not contain silicon atom-bonded hydrogen atoms or silicon atom-bonded alkenyl groups, tackifiers, release agents, metal soaps, heat resistance imparters, cold resistance imparters, thermal conductivity fillers, flame retardants, thixotropic agents, phosphors, solvents, and the like.

[0068] In one embodiment of the present invention, the curable silicone composition may contain organopolysiloxane components other than components (A-1), (A-2), (A-3), (B-1), and (B-2) as long as it does not contradict the objectives of the present invention. The amount of organopolysiloxane components other than components (A-1), (A-2), (A-3), (B-1), and (B-2) is preferably 0 to 20% by mass, more preferably 0 to 10% by mass, and even more preferably 0 to 5% by mass, based on the total mass of all organopolysiloxane components contained in the composition.

[0069] Examples of inorganic fillers include fumed silica, crystalline silica, precipitated silica, silsesquioxane, magnesium oxide, iron oxide, talc, mica, diatomaceous earth, metal oxide particles such as glass beads, inorganic fillers such as aluminum hydroxide, magnesium carbonate, calcium carbonate, and zinc carbonate, fibrous fillers such as glass fibers, and fillers obtained by surface hydrophobizing these fillers with organosilicon compounds such as organoalkoxysilane compounds, organochlorosilane compounds, organosilazane compounds, and low molecular weight siloxane compounds. Silicone rubber powder and silicone resin powder may also be included. However, the amount of inorganic filler may be 40% by mass or less, 30% by mass or less, 20% by mass or less, or 10% by mass or less of the composition.

[0070] The surface treatment agents for powders are not particularly limited, but include organosilazanes, organocyclosiloxanes, organochlorosilanes, organoalkoxysilanes, low molecular weight linear siloxanes, and organic compounds. Examples of organic compounds include polyhydric alcohols, alkanolamines or their derivatives, organosilicon compounds such as organosiloxanes, higher fatty acids or their metal salts, organometallic compounds, organometallic complexes, fluorinated organic compounds, anionic surfactants, cationic surfactants, and nonionic surfactants.

[0071] As adhesion promoters, organosilicon compounds having at least one alkoxy group bonded to a silicon atom in one molecule are preferred. Examples of such alkoxy groups include methoxy, ethoxy, propoxy, butoxy, and methoxyethoxy groups, with methoxy being particularly preferred. Examples of groups other than alkoxy groups that bond to silicon atoms in organosilicon compounds include halogen-substituted or unsubstituted monovalent hydrocarbon groups such as alkyl groups, alkenyl groups, aryl groups, aralkyl groups, and halogenated alkyl groups; glycidoxyalkyl groups such as 3-glycidoxypropyl and 4-glycidoxybutyl groups; epoxycyclohexylalkyl groups such as 2-(3,4-epoxycyclohexyl)ethyl and 3-(3,4-epoxycyclohexyl)propyl groups; epoxyalkyl groups such as 3,4-epoxybutyl and 7,8-epoxyoctyl groups; acrylic group-containing monovalent organic groups such as 3-methacryloxypropyl groups; and hydrogen atoms. The organosilicon compound preferably has an alkenyl group or a group that can react with a silicon-bonded hydrogen atom in the composition, and more specifically, it is preferable that it has a silicon-bonded hydrogen atom or an alkenyl group. Furthermore, since it can impart good adhesion to various substrates, it is preferable that the organosilicon compound has at least one epoxy-group-containing monovalent organic group in one molecule. Examples of such organosilicon compounds include organosilane compounds, organosiloxane oligomers, and alkyl silicates. Examples of molecular structures of these organosiloxane oligomers or alkyl silicates include linear, partially branched linear, branched, cyclic, and network structures, and linear, branched, and network structures are particularly preferred.Examples of organosilicon compounds include silane compounds such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-methacryloxypropyltrimethoxysilane; siloxane compounds having at least one silicon atom-bonded alkenyl group, a silicon atom-bonded hydrogen atom, and a silicon atom-bonded alkoxy group in one molecule; a mixture of a silane compound or siloxane compound having at least one silicon atom-bonded alkoxy group and a siloxane compound having at least one silicon atom-bonded hydroxyl group and a silicon atom-bonded alkenyl group in one molecule; methyl polysilicate; ethyl polysilicate; and epoxy group-containing ethyl polysilicate. This adhesion promoter is preferably a low-viscosity liquid, and its viscosity is not limited, but is preferably in the range of 1 to 500 mPa·s at 25°C. Furthermore, the content of this adhesion promoter is not limited, but is preferably in the range of 0.01 to 10 parts by mass per 100 parts by mass of the total composition.

[0072] The mold release agent is not particularly limited, but examples include carboxylic acid-based mold release agents, ester-based mold release agents, ether-based mold release agents, ketone-based mold release agents, and alcohol-based mold release agents. These may be used individually or in combination of two or more. Furthermore, the mold release agent may be one that does not contain silicon atoms, one that contains silicon atoms, or a mixture thereof. More specifically, carnauba wax, montan wax, calcium stearate, calcium montanate, magnesium stearate, magnesium montanate, zinc stearate, zinc montanate, ester-based waxes, olefin-based waxes, and the like are examples of mold release agents.

[0073] The curable silicone composition of the present invention can be prepared by mixing its components. The method of mixing the components is not particularly limited and can be any conventionally known method, but usually a homogeneous mixture is obtained by simple stirring. Furthermore, if the composition includes solid components such as inorganic fillers as optional components, mixing using a mixing device is more preferable. Such mixing devices are not particularly limited, and examples include single-screw or twin-screw continuous mixers, double-roll mixers, Ross mixers, Hobart mixers, Dental mixers, Planetary mixers, Kneader mixers, Henschel mixers, and the like.

[0074] The curable silicone composition of the present invention cures at room temperature or by heating, but heating is preferable for rapid curing. The heating temperature is preferably in the range of 50 to 200°C, and more preferably in the range of 50 to 90°C. The curable silicone composition of the present invention can be cured at a low temperature and in a short time; for example, when determining curing by the method described in the examples, it can be cured within 20 minutes at 90°C.

[0075] [Cured product] One embodiment of the present invention relates to a cured product of a curable silicone composition. The cured product of the curable silicone composition of the present invention is obtained by curing the curable silicone composition of the present invention. The shape of the cured product is not particularly limited and may be, for example, a sheet or a film. When the cured product is used as a reflective material for optoelectronic devices, the cured product may be in a shape suitable for use as a reflective material. The cured product can be handled on its own, or it can be handled when incorporated into a substrate. If the curable silicone composition of the present invention contains a white pigment, the cured product may have a pencil hardness of preferably 2B or higher, more preferably B or higher, and even more preferably F or higher, in the pencil hardness test shown in the examples. If the cured product of the present invention is a transparent cured product that does not contain a pigment, the Shore D hardness (measured at 25°C using a Type D durometer specified in JIS K 6253-1997 "Hardness Test Method for Vulcanized Rubber and Thermoplastic Rubber") may be preferably 30 or higher, more preferably 40 or higher.

[0076] [Reflective material for optoelectronic equipment] One embodiment of the present invention relates to a reflective material for optical semiconductor devices, comprising a cured product of a curable silicone composition. The reflective material for optical semiconductor devices of the present invention is obtained by curing the curable silicone composition of the present invention. The optical semiconductor device is not particularly limited, and examples include light-emitting diodes (LEDs), semiconductor lasers, photodiodes, phototransistors, solid-state imaging devices, and light-emitting and light-receiving elements for photocouplers, with light-emitting diodes (LEDs) being particularly preferred.

[0077] [Optical Semiconductor Equipment] The optical semiconductor device of the present invention comprises a reflective material for optical semiconductor devices of the present invention. Examples of optical semiconductor devices include light-emitting diodes (LEDs), semiconductor lasers, photodiodes, phototransistors, solid-state imaging devices, and light-emitting and light-receiving elements for photocouplers, with light-emitting diodes (LEDs) being particularly preferred. [Examples]

[0078] The present invention will be described in detail by the following examples, but is not limited to those described.

[0079] The components used in the examples and comparative examples are shown below. In the following formulas, Me represents a methyl group, Vi represents a vinyl group, and Ph represents a phenyl group. The numerical values ​​attached to each unit in the following average unit formulas represent the molar ratio of that unit. In the table, M represents (Me3SiO 1 / 2 ) represents the M unit, and M(Vi) is (ViMe2SiO 1 / 2 M represents the unit of ), and M(H) is (HMe2SiO 1 / 2 ) represents the M unit, and D is (Me2SiO 2 / 2 D represents the unit of ), and D(Ph2) is (Ph2SiO 2 / 2 ) represents the D unit, and T(Ph) is (PhSiO 3 / 2 ) represents the T unit, and Q is (SiO 4 / 2 This represents the Q unit. In the examples, the vinyl group content (mass%) is the value quantified by the titration method described above.

[0080] Component A-1-1: Average unit formula (ViMe2SiO 1 / 2 ) 0.066 (Me3SiO 1 / 2 ) 0.409 (SiO 4 / 2 ) 0.521 (OH) 0.045 A resinous alkenyl group-containing organopolysiloxane represented by [formula], with a vinyl group content of 2.6% by mass and a weight-average molecular weight (Mw) of 5000. Component A-1-2: Average unit formula (ViMe2SiO 1 / 2 ) 0.15 (Me3SiO 1 / 2 ) 0.45 (SiO 4 / 2 ) 0.40 A resinous alkenyl group-containing organopolysiloxane represented by [formula], with a vinyl group content of 5.44% by mass. Component A-1-3: Average unit formula (ViMe2SiO 1 / 2 ) 0.55 (Me3SiO 1 / 2 ) 0.05 (SiO 4 / 2 ) 0.40 A resinous alkenyl group-containing organopolysiloxane represented by [formula], with a vinyl group content of 18.8% by mass. Component A-2-1: Average structural formula ViMe2SiO(Me2SiO) 195 A linear organopolysiloxane containing alkenyl groups, represented by SiMe2Vi, with a vinyl group content of 0.38% by mass. Component A-3-1: Structural formula (ViMe2SiO 1 / 2 )4(SiO 4 / 2 A low molecular weight siloxane compound represented by ), with a vinyl group content of 25.0% by mass and a molecular weight of 432. Component B-1-1: Average unit formula (HMe2SiO 1 / 2 ) 0.6 (PhSiO 3 / 2 ) 0.4 A phenyl group-containing resinous organohydrogenpolysiloxane represented by [formula], with a hydrogen atom content of 0.65% by mass bonded to silicon atoms. Component B-2-1: Structural formula (HMe2SiO 1 / 2 )2(Ph2SiO 2 / 2A phenyl group-containing linear organohydrogenpolysiloxane represented as ( ), with a hydrogen atom content of 0.60% by mass bonded to silicon atoms and a molecular weight of 332. Component B-3-1: Average unit formula (HMe2SiO 1 / 2 ) 0.600 (Me3SiO 1 / 2 ) 0.002 (SiO 4 / 2 ) 0.398 A phenyl group-free resinous organohydrogenpolysiloxane represented by [formula], containing 0.95% by mass of hydrogen atoms bonded to silicon atoms, with a weight-average molecular weight (Mw) of 1600. Component B-3-2: Average structural formula (HMe2SiO 1 / 2 )(Me2SiO 2 / 2 ) 20 (HMe2SiO 1 / 2 A phenyl group-free linear organohydrogenpolysiloxane represented by ), with a hydrogen atom content of 0.14% by mass bonded to the silicon atom. Component C-1: A complex of platinum with a platinum concentration of 4.0% by mass and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane. Ingredient D-1: 1-ethynyl-1-cyclohexanol Ingredient E-1: Titanium dioxide OE7660: Phenyl-based silicone for LED lighting (manufactured by Dow Corning) JCR-6122: Methyl-based silicone for LED lighting (manufactured by Dow Corning)

[0081] Each component was mixed in the compositions (parts by mass) shown in Tables 1 to 3 to prepare a curable silicone composition. In Tables 1 to 3, H / Vi represents (total number of moles of hydrogen atoms bonded to silicon atoms in the composition) / (total number of moles of alkenyl groups (i.e., vinyl groups) bonded to silicon atoms in the composition).

[0082] [evaluation] For each composition in the examples or comparative examples, the curing rate of the composition, the pencil hardness of the cured product, the reflectance of the cured product, and the refractive index (RI) of the cured product were measured according to the following method, and the results are shown in Tables 1 to 3.

[0083] [Curing speed of the composition] The curing time was determined by measuring 5.56g of the curable silicone composition on an MDR (Moving Die rheometer) until the torque reached a plateau at 90°C. This time was considered the time when the entire composition had cured. A curing time of 20 minutes or less was considered acceptable.

[0084] [Pencil hardness] A curable silicone composition was applied to a glass plate and cured by heating at 90°C for 20 minutes to obtain a test specimen with a cured film thickness of 30-50 μm on the glass plate. In accordance with JIS K 5400, the pencil concentration number one level lower when the cured film fractured at the interface was recorded when the cured film on the test specimen was scratched with a pencil under conditions of a load of 1000 g and a moving speed of 0.5 mm / s.

[0085] [Reflectance] A curable silicone composition was applied to a glass substrate and cured by heating at 90-150°C for 0.5-2 hours to obtain a cured product with a thickness of 30 μm. The reflectance (%) of light (wavelength 450 nm) was measured on the obtained cured product using a spectrophotometer CM-5 (manufactured by Konica Minolta).

[0086] [Refractive Index (RI)] A curable silicone composition was applied to a glass substrate and cured by heating at 150°C for 2 hours to obtain a cured product with a thickness of 30 μm. The refractive index of the obtained cured product was measured at 25°C using an Abbe refractometer. Visible light (589 nm) was used as the light source.

[0087] [Table 1]

[0088] [Table 2]

[0089] [Table 3]

[0090] Examples 1-8 and Comparative Examples 2-3 demonstrate that the curable silicone composition of the present invention is superior overall to commercially available silicone compositions for LED lighting in terms of hardness of the cured product, reflectivity of the cured product, and low-temperature curability. Examples 1-8 and Comparative Examples 1, 4-8 demonstrate that a resin-like organohydrogenpolysiloxane containing phenyl groups is necessary to obtain a cured product with sufficient hardness. Examples 1-8 and Comparative Example 5 demonstrate that when the H / Vi ratio is 0.5, sufficient hardness of the cured product cannot be obtained even if the composition contains a resin-like organohydrogenpolysiloxane containing phenyl groups. [Industrial applicability]

[0091] The curable silicone composition of the present invention can be used to form materials for optoelectronic devices, and is particularly useful as a material for manufacturing reflective materials for optoelectronic devices such as light-emitting diodes (LEDs), semiconductor lasers, photodiodes, phototransistors, solid-state imaging devices, and light-emitting and light-receiving elements for photocouplers.

Claims

1. A curable silicone composition, (A-1) Average unit formula: (R １ R ２ ２ Yes １／２ ) ａ (R ２ ３ Yes １／２ ) ｂ (Yes) ４／２ ) ｃ (XO １／２ ) ｄ (In the formula, R １ It is an alkenyl group, R ２ It is a monovalent hydrocarbon group that does not have an aliphatic unsaturated carbon bond, The amount of aryl-containing groups bonded to silicon atoms is 0 mol% or more and less than 10 mol%, based on the total number of moles of all organic groups bonded to silicon atoms. X is a hydrogen atom or an alkyl group, a, b, c, and d represent the molar ratios of their respective units, where 0 < a ≤ 0.7, 0 < b ≤ 0.8, 0 < c ≤ 0.7, 0 ≤ d ≤ 0.2, and a + b + c = 1.

0. Represented as such, a resinous organopolysiloxane having at least two alkenyl groups bonded to a silicon atom in one molecule, (B-1) A resinous organohydrogenpolysiloxane having an amount of aryl-containing groups bonded to silicon atoms of 10 mol% or more based on the total number of moles of all organic groups bonded to silicon atoms, having at least two hydrogen atoms bonded to silicon atoms in one molecule, but not having alkenyl groups bonded to silicon atoms, and containing at least one unit selected from T units (RSIO3 / 2) (wherein R is a monovalent hydrocarbon group or a hydrogen atom) and Q units (SiO4 / 2) in its molecular structure, and having a weight-average molecular weight of 1,000 to 100,000, and (C) Catalyst for hydrosilylation reaction Includes, The amount of linear organopolysiloxane having at least two alkenyl groups bonded to (A-2) silicon atoms in the composition is 0 to 3% by mass, based on the total mass of all organopolysiloxane components contained in the composition. The ratio of (total number of moles of hydrogen atoms bonded to silicon atoms in the composition) to (total number of moles of alkenyl groups bonded to silicon atoms in the composition) is between 0.7 and 1.

2. A curable silicone composition.

2. The curable silicone composition according to claim 1, further comprising (A-3) a silane compound or siloxane compound having at least two alkenyl groups bonded to silicon atoms in one molecule and having a molecular weight of less than 500, in amounts such that [(A-1) mass / ((A-3) mass + (A-1) mass)] is 0.3 or more and 1 or less.

3. The curable silicone composition according to claim 1, further comprising (B-2) a linear organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in one molecule, but without alkenyl groups bonded to silicon atoms, in an amount such that [(B-1) component mass / ((B-2) component mass + (B-1) component mass)] is 0.1 or more and 1 or less.

4. (D) The curable silicone composition according to claim 1, further comprising a hydrosilylation reaction inhibitor.

5. (E) The curable silicone composition according to claim 1, further comprising a white pigment.

6. A cured product of the curable silicone composition according to claim 1.

7. A reflective material for optical semiconductor equipment comprising a cured product of the curable silicone composition described in claim 1.

8. An optoelectronic device comprising a reflective material for optoelectronic devices as described in claim 7.

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