Curable white silicone formulation, a reflective material for optical semiconductor module and optical semiconductor device

Abstract

The present invention aims to provide a curable white silicone composition capable of forming a curable product having high light reflectivity and excellent light resistance. According to the present invention, the above problem is solved by a curable white silicone composition comprising (A) an organopolysiloxane having at least two alkenyl groups in one molecule, (B) a cerium-containing organopolysiloxane, (C) a white pigment, and (D) a curing catalyst.

Description

Technology Field

[0001] The present invention relates to a curable white silicon composition, and more specifically, to a curable white silicon composition preferably used as a reflector for an opto-semiconductor device. Furthermore, the present invention relates to a reflector for an opto-semiconductor device comprising a cured product of such a curable white silicon composition, and to an opto-semiconductor device having said reflector. Background Technology

[0002] Curable silicone compositions are utilized in a wide range of industrial fields because they form cured products with excellent heat resistance, cold resistance, electrical insulation, weather resistance, water repellency, and transparency upon curing. Compared to other organic materials, the cured products of these curable silicone compositions do not discolor easily and exhibit minimal changes in physical properties, making them suitable as optical materials as well.

[0003] For example, Patent Document 1 describes (A) a linear organopolysiloxane having at least two alkenyl groups in one molecule, (B) the following average unit formula: (R 1 SiO 3 / 2 ) a (R 1 2SiO 2 / 2 ) b (R 1 3SiO 1 / 2 ) c (SiO 4 / 2 ) d (XO 1 / 2 ) e (during food, R 1 Each is independently an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or a group in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms, provided that at least two Rs in one molecule 1An organopolysiloxane represented by (a) an alkenyl group, X is a hydrogen atom or an alkyl group, a is a number from 0 to 0.3, b is 0 or positive, c is positive, d is positive, e is a number from 0 to 0.4, and a + b + c + d = 1, c / d is a number from 0 to 10, and b / d is a number from 0 to 0.5), (C) an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms in one molecule, (D) a cerium-containing organopolysiloxane, and (E) a curable silicone composition comprising at least a catalyst for a hydrosilylation reaction. In addition, the above-mentioned literature describes that the above-mentioned curable silicon composition can be used in a curable silicon composition for an opto-semiconductor device requiring transparency, and specifically, that the above-mentioned curable silicon composition can be used in an opto-semiconductor semi-curable silicon composition for encapsulating, coating, or bonding an opto-semiconductor device.

[0004] In addition, Patent Document 2 describes a resin composition comprising 100 parts by mass of an organic resin and 50 to 1000 parts by mass of an inorganic filler, wherein 10 to 100% by mass of the inorganic filler is a rare earth element oxide. Furthermore, it is described that by using this resin composition, a reflector for a light-emitting semiconductor device and a light-emitting semiconductor device having high light reflectivity and low reduction in brightness can be provided. Prior art literature

[0005] Patent Document 1: Japanese Patent Publication No. 2016-513165 Patent Document 2: Japanese Patent Publication No. 2011-225828 The problem to be solved

[0006] However, when a cured product of a conventional curable silicon composition was used as a reflector for an opto-semiconductor device, there were problems such as insufficient light resistance, cracking of the reflector, or shrinkage of the reflector due to long-term use.

[0007] The objective of the present invention is to provide a curable white silicone composition capable of forming a curable product having high light reflectivity and excellent light resistance.

[0008] Another objective of the present invention is to provide a reflector for an optical semiconductor device having high light reflectivity and excellent light resistance. Furthermore, another objective of the present invention is to provide an optical semiconductor device equipped with the reflector for an optical semiconductor device according to the present invention. means of solving the problem

[0009] In order to solve the above problem, the inventors of the present invention, after conducting an in-depth investigation, surprisingly discovered that cerium-containing organopolysiloxane can impart excellent light resistance to a cured silicone composition while maintaining a high light reflectivity, and thus arrived at the present invention.

[0010] Therefore, the present invention

[0011] (A) Organopolysiloxane having at least two alkenyl groups in one molecule,

[0012] (B) Cerium-containing organopolysiloxane,

[0013] (C) White pigment, and

[0014] (D) Curing catalyst

[0015] This relates to a curable white silicone composition comprising

[0016] The cerium atoms in the above (B) cerium-containing organopolysiloxane may be in an amount of 0.5 to 1,000 ppm with respect to the total mass of the composition.

[0017] The average particle size of the above (C) white pigment may be 0.1 to 5 μm.

[0018] The content of the above (C) white pigment may be 10 to 80 mass% with respect to the total mass of the composition.

[0019] The above (D) curing catalyst preferably includes a catalyst for a hydrosilylation reaction.

[0020] It is preferable that the above (A) organopolysiloxane comprises a resin-type organopolysiloxane.

[0021] The above resin-type organopolysiloxane is

[0022] (A-2) Average unit formula: (R 1 3SiO 1 / 2 ) f (SiO 4 / 2 ) g (XO 1 / 2 ) h

[0023] (during food, R 1 is a monovalent hydrocarbon group with the same or different halogen substitution or non-substitution, provided that at least two R 1 It can be represented as follows: is an alkenyl group, f is an integer from 5 to 1,000, g is an integer from 5 to 1,000, X is a hydrogen atom or an alkyl group, and h is an integer from 0 to 10.

[0024] It is preferable that the above (A) organopolysiloxane contains resin-type organopolysiloxane and linear-type organopolysiloxane in an amount such that the ratio of linear-type organopolysiloxane to resin-type organopolysiloxane content is 1 or more.

[0025] The present invention also relates to a reflector for an optical semiconductor device comprising a cured product of a curable silicon composition according to the present invention.

[0026] The present invention also relates to an optical semiconductor device having a reflective material for an optical semiconductor device according to the present invention. Effects of the invention

[0027] According to the curable white silicon composition of the present invention, a cured product having excellent light resistance while maintaining high light reflectivity can be formed. In addition, according to the reflective material for an opto-semiconductor device of the present invention, a reflective material having excellent light resistance while maintaining high light reflectivity can be provided. Specific details for implementing the invention

[0028] [Curable white silicone composition]

[0029] The curable white silicone composition according to the present invention is

[0030] (A) Organopolysiloxane having at least two alkenyl groups in one molecule,

[0031] (B) Cerium-containing organopolysiloxane,

[0032] (C) White pigment, and

[0033] (D) Curing catalyst

[0034] It is made up of at least...

[0035] Hereinafter, each component of the curable white silicone composition of the present invention will be described in detail.

[0036] (A) Organopolysiloxane having at least two alkenyl groups in one molecule

[0037] (A) The component is the main component of the present composition and is a curable organopolysiloxane having at least two alkenyl groups in one molecule. The curable white silicone composition according to the present invention may include one type of (A) organopolysiloxane, or two or more types of (A) organopolysiloxanes.

[0038] Examples of molecular structures of component (A) include linear, linear with some branches, branched, cyclic, and three-dimensional network structures. Component (A) may be one type of organopolysiloxane having these molecular structures, or a mixture of two or more types of organopolysiloxanes having these molecular structures. Preferably, the curable white silicone composition of the present invention comprises both linear organopolysiloxane and three-dimensional network organopolysiloxane as component (A).

[0039] (A) Examples of alkenyl groups in the component include alkenyl groups having 2 to 12 carbon atoms, such as vinyl groups, allyl groups, butenyl groups, pentenyl groups, hexenyl groups, heptenyl groups, octenyl groups, nonenyl groups, decenyl groups, undecenyl groups, and dodecenyl groups, and preferably vinyl groups. (A) Groups bonded to silicon atoms other than alkenyl groups in the component include alkyl groups having 1 to 12 carbon atoms, such as methyl groups, ethyl groups, propyl groups, isopropyl groups, n-butyl groups, isobutyl groups, tert-butyl groups, n-pentyl groups, neopentyl groups, hexyl groups, cyclohexyl groups, heptyl groups, octyl groups, nonyl groups, decyl groups, undecenyl groups, and dodecyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl groups, tolyl groups, xylyl groups, and naphthyl groups; Examples include aralkyl groups having 7 to 20 carbon atoms, such as benzyl groups, phenethyl groups, 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 atoms, chlorine atoms, or bromine atoms. (A) Silicon atoms in the components may have a small amount of alkoxy groups, such as hydroxyl groups, methoxy groups, and ethoxy groups, to the extent that the purpose of the present invention is not impaired.

[0040] (A) The component preferably comprises at least one resin-type organopolysiloxane. As specified herein, a resin-type organopolysiloxane refers to an organopolysiloxane having a branched or three-dimensional network structure in its molecular structure. In one embodiment, the resin-type organopolysiloxane of component (A) comprises at least one RSiO in its molecular structure. 3 / 2 Siloxane units (T units) and / or SiO represented by 4 / 2 It includes a siloxane unit (Q unit) represented by . In one embodiment, the resin-type organopolysiloxane of component (A) includes a Q unit in its molecular structure but does not include a T unit. In another embodiment, when component (A) is an aryl group-containing resin-type organopolysiloxane, component (A) includes a T unit in its molecular structure but does not include a Q unit.

[0041] In one embodiment, the resin-type organopolysiloxane of component (A) preferably has a ratio of Q units in its molecular structure of 0.1 or more, more preferably 0.2 or more, even more preferably 0.3 or more, and particularly preferably 0.4 or more. In a preferred embodiment, the resin-type organopolysiloxane of the present invention has a ratio of Q units in its molecular structure of 0.9 or less, preferably 0.8 or less, more preferably 0.7 or less, and even more preferably 0.6 or less. In one embodiment, the resin-type organopolysiloxane of component (A) has a ratio of T units in its molecular structure of 0.2 or less, preferably 0.1 or less, and even more preferably does not contain T units. Meanwhile, the ratio of T units and Q units is the general formula of the resin-type organopolysiloxane: R3SiO 1 / 2 Siloxane units represented by (M units), general formula: R2SiO 2 / 2 Siloxane unit (D unit) denoted by, general formula: RSiO 3 / 2Siloxane units (T units) represented by, and formula: SiO 4 / 2 It can be calculated based on the amount of siloxane units (Q units) indicated by.

[0042] In another embodiment, when the resin-type organopolysiloxane of component (A) is an aryl group-containing resin-type organopolysiloxane, the resin-type organopolysiloxane of component (A) preferably has a ratio of T units in its molecular structure of 0.1 or more, more preferably 0.3 or more, even more preferably 0.5 or more, and particularly preferably 0.7 or more. In a preferred embodiment, the aryl group-containing resin-type organopolysiloxane of the present invention has a ratio of T units in its molecular structure of 0.95 or less, preferably 0.9 or less, more preferably 0.85 or less, and even more preferably 0.8 or less. In one embodiment, the aryl group-containing resin-type organopolysiloxane of component (A) has a ratio of Q units in its molecular structure of 0.2 or less, preferably 0.1 or less, and even more preferably does not contain Q units.

[0043] In addition, the resin-type organopolysiloxane of component (A) preferably has a ratio of M units in its molecular structure of 0.1 or more, and more preferably 0.2 or more. In a preferred embodiment, the resin-type organopolysiloxane of the present invention has a ratio of M units in its molecular structure of 0.9 or less, preferably 0.8 or less, more preferably 0.7 or less, and particularly 0.6 or less. In one embodiment, the resin-type organopolysiloxane of component (A) has a ratio of D units in its molecular structure of 0.2 or less, preferably 0.1 or less, and more preferably does not contain D units. Meanwhile, the ratio of M units and D units is the general formula of the resin-type organopolysiloxane: R3SiO 1 / 2 Siloxane units represented by (M units), general formula: R2SiO 2 / 2Siloxane unit (D unit) denoted by, general formula: RSiO 3 / 2 Siloxane units (T units) represented by, and formula: SiO 4 / 2 It can be calculated based on the amount of siloxane units (Q units) indicated by.

[0044] (A) The content of alkenyl groups included in the resin-type organopolysiloxane of the component (mol% of alkenyl groups in the total silicon atom bonding functional groups of the resin-type organopolysiloxane) can be designed as desired, but may be 0.5 mol% or more, preferably 1 mol% or more, more preferably 2 mol% or more, even more preferably 3 mol% or more, preferentially 4 mol% or more, particularly preferably 5 mol% or more, or 6 mol% or more, and may be 30 mol% or less, preferably 25 mol% or less, more preferably 20 mol% or less, preferentially 18 mol% or less. Meanwhile, the content of alkenyl groups can be determined by analysis such as Fourier transform infrared spectrophotometry (FT-IR) or nuclear magnetic resonance (NMR).

[0045] In one embodiment of the present invention, the resin-type organopolysiloxane of component (A) is

[0046] (A-1) Average unit formula: (R 1 3SiO 1 / 2 ) a (R 1 2SiO 2 / 2 ) b (R 1 SiO 3 / 2 ) c (SiO 4 / 2 ) d (XO 1 / 2 ) e

[0047] (during food, R 1 is an identical or different halogen-substituted or unsubstituted monovalent hydrocarbon group, provided that at least two Rs in one molecule 1It can be represented as follows: ≡ is an alkenyl group, X is a hydrogen atom or an alkyl group, and a, b, c, d, and e are numbers satisfying 0 ≤ a ≤ 1.0, 0 ≤ b ≤ 1.0, 0 ≤ c < 0.9, 0 ≤ d < 0.5, 0 ≤ e < 0.4, a + b + c + d = 1.0, and c + d > 0.

[0048] Among the above foods, R 1 The halogen-substituted or unsubstituted monovalent hydrocarbon groups include: alkyl groups having 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 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 alkenyl groups having 2 to 12 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl groups. Examples include groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine, chlorine, or bromine. R 1 To the extent that it does not impair the purpose of the present invention, it may be an alkoxy group such as a hydroxyl group, methoxy group, or ethoxy group in small amounts. 1 The is preferably selected from a phenyl group, an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group, or an alkenyl group having 2 to 6 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms or a phenyl group.

[0049] In the average unit formula (A-1), X is a hydrogen atom or an alkyl group. As for the alkyl group of X, an alkyl group having 1 to 3 carbon atoms is preferred, and specifically, methyl, ethyl, and propyl groups are exemplified.

[0050] In the average unit formula (A-1), a is preferably in the range of 0.1 ≤ a ≤ 0.9, more preferably in the range of 0.15 ≤ a ≤ 0.8, even more preferably in the range of 0.2 ≤ a ≤ 0.7, and particularly in the range of 0.25 ≤ a ≤ 0.6. In the average unit formula (A-1), b is preferably in the range of 0 ≤ b ≤ 0.3, more preferably in the range of 0 ≤ b ≤ 0.2, and particularly in the range of 0 ≤ b ≤ 0.1. In the average unit formula (A-1), c is preferably in the range of 0 ≤ c ≤ 0.9, more preferably in the range of 0 ≤ c ≤ 0.85, and particularly in the range of 0 ≤ c ≤ 0.8. In the average unit formula (A-1), d is preferably in the range of 0.1 ≤ d ≤ 0.9, more preferably in the range of 0.2 ≤ d ≤ 0.8, even more preferably in the range of 0.3 ≤ d ≤ 0.7, and particularly in the range of 0.4 ≤ d ≤ 0.6. In the average unit formula (A-1), e is preferably in the range of 0 ≤ e ≤ 0.3, more preferably in the range of 0 ≤ e ≤ 0.2, and particularly in the range of 0 ≤ e ≤ 0.1.

[0051] (A) The resin-type organopolysiloxane of component A preferably comprises M units and Q units, and more preferably consists only of M units and Q units. The ratio of M units to Q units is not particularly limited, but it is preferable that the ratio of M units to Q units be within the range of 0.5 to 3, and more preferable that it be within the range of 0.8 to 2. This is because if the ratio of M units to Q units is above the lower limit of the above range, the mechanical properties of the resulting cured product are good, while if it is below the upper limit of the above range, compatibility with component A is improved.

[0052] Accordingly, the resin-type organopolysiloxane of component (A) is

[0053] (A-2) Average unit formula: (R1 3SiO 1 / 2 ) f (SiO 4 / 2 ) g (XO 1 / 2 ) h

[0054] (during food, R 1 ...is the same as above, provided that at least 2 R 1 It can be represented as follows: is an alkenyl group, f is an integer from 5 to 1,000, preferably an integer from 10 to 500, more preferably an integer from 20 to 100, even more preferably an integer from 25 to 75, g is an integer from 5 to 1,000, preferably an integer from 10 to 500, more preferably an integer from 20 to 100, even more preferably an integer from 25 to 75, X is the same as above, and h is an integer from 0 to 10.

[0055] In another embodiment, the resin-type organopolysiloxane of component (A) preferably comprises M units and T units, and more preferably consists only of M units and T units. The ratio of M units to T units is not particularly limited, but it is preferable that the ratio of M units to T units be within the range of 0.1 to 1, and more preferable that it be within the range of 0.2 to 0.5. This is because if the ratio of M units to T units is above the lower limit of the above range, the mechanical properties of the resulting cured product are good, while if it is below the upper limit of the above range, compatibility with component (A) is improved.

[0056] Accordingly, the resin-type organopolysiloxane of component (A) is

[0057] (A-3) Average unit formula: (R 1 3SiO 1 / 2 ) i (R 2 SiO 3 / 2 ) j (XO 1 / 2 ) k

[0058] (during food, R 1 ...is the same as above, provided that at least 2 R 1 is an alkenyl group, and R 2 The above R 1 It can be represented as follows, where i is an integer from 5 to 1,000, preferably an integer from 10 to 500, more preferably an integer from 20 to 100, and even more preferably an integer from 25 to 75, j is an integer from 5 to 1,000, preferably an integer from 10 to 500, more preferably an integer from 20 to 100, and even more preferably an integer from 25 to 75, X is the same as above, and k is an integer from 0 to 10.

[0059] (A) When the resin-type organopolysiloxane of the component contains aryl groups, the content (mol% of aryl groups in the total silicon atom bonded functional groups of the resin-type organopolysiloxane) can be designed as desired, but may be 5 mol% or more, preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, preferentially 35 mol% or more, particularly preferably 40 mol% or more, or 45 mol% or more, and 75 mol% or less, preferably 70 mol% or less, more preferably 65 mol% or less, preferentially 60 mol% or less. Meanwhile, the content of aryl groups can be determined by analysis such as Fourier transform infrared spectrophotometry (FT-IR) or nuclear magnetic resonance (NMR).

[0060] The curable white silicone composition of the present invention preferably comprises a straight-chain organopolysiloxane as component (A).

[0061] These (A) components include: dimethylvinylsiloxy group-locked dimethylpolysiloxane at both ends of the molecular chain; diphenylvinylsiloxy group-locked dimethylpolysiloxane at both ends of the molecular chain; dimethylvinylsiloxy group-locked dimethylsiloxane·methylphenylsiloxane copolymer at both ends of the molecular chain; dimethylvinylsiloxy group-locked dimethylsiloxane·diphenylsiloxane copolymer at both ends of the molecular chain; dimethylvinylsiloxy group-locked dimethylsiloxane·methylvinylsiloxane copolymer at both ends of the molecular chain; dimethylvinylsiloxy group-locked dimethylsiloxane·methylphenylsiloxane·methylvinylsiloxane copolymer at both ends of the molecular chain; dimethylvinylsiloxy group-locked dimethylsiloxane·diphenylsiloxane·methylvinylsiloxane copolymer at both ends of the molecular chain; dimethylvinylsiloxy group-locked dimethylsiloxane·diphenylsiloxane·methylvinylsiloxane copolymer at both ends of the molecular chain; trimethylsiloxy group-locked methylvinylpolysiloxane at both ends of the molecular chain; and dimethylvinylsiloxy group-locked dimethylsiloxane at both ends of the molecular chain. Examples include a trimethylsiloxy group-locked methylvinylsiloxane-methylphenylsiloxane copolymer, a molecular chain-twice trimethylsiloxy group-locked methylvinylsiloxane-diphenylsiloxane copolymer, and a molecular chain-twice trimethylsiloxy group-locked dimethylsiloxane-methylvinylsiloxane copolymer.

[0062] (A) The content of alkenyl groups included in the straight-chain organopolysiloxane of the component (mol% of alkenyl groups in the total silicon atom bonding functional groups of the straight-chain organopolysiloxane) can be designed as desired, but may be 0.1 mol% or more, preferably 0.2 mol% or more, more preferably 0.3 mol% or more, even more preferably 0.4 mol% or more, preferentially 0.5 mol% or more, and 10 mol% or less, preferably 8 mol% or less, more preferably 6 mol% or less, preferentially 5 mol% or less. Meanwhile, the content of alkenyl groups can be determined by analysis such as Fourier transform infrared spectrophotometry (FT-IR) and nuclear magnetic resonance (NMR).

[0063] (A) The linear organopolysiloxane of the component is

[0064] (A-3) General formula: R 1 3SiO(R 12SiO) m OSiR 1 3

[0065] (during food, R 1 ...is the same as above, provided that at least 2 R 1 It can be represented as follows: is an alkenyl group, and m is an integer from 5 to 1,000, preferably an integer from 10 to 500, more preferably an integer from 25 to 300, and even more preferably an integer from 50 to 250.

[0066] (A) When the linear organopolysiloxane of the component contains aryl groups, the content of the aryl groups (mol% of the aryl groups in the total silicon atom bonded functional groups of the linear organopolysiloxane) can be designed as desired, but may be 10 mol% or more, preferably 20 mol% or more, more preferably 30 mol% or more, even more preferably 35 mol% or more, preferentially 40 mol% or more, and 70 mol% or less, preferably 60 mol% or less, more preferably 55 mol% or less, preferentially 50 mol% or less. Meanwhile, the content of the aryl groups can be determined by analysis such as Fourier transform infrared spectrophotometry (FT-IR) or nuclear magnetic resonance (NMR).

[0067] The curable white silicone composition of the present invention preferably comprises both resin-type organopolysiloxane and linear-chain organopolysiloxane as component (A). The ratio of the content of resin-type organopolysiloxane and linear-chain organopolysiloxane is not particularly limited, but preferably the ratio of linear-chain organopolysiloxane to resin-type organopolysiloxane is 0.1 or more, more preferably 0.5 or more, even more preferably 1 or more, and particularly 1.5 or more. In addition, the ratio of linear-chain organopolysiloxane to resin-type organopolysiloxane as component (A) is preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less.

[0068] The content of component (A) is not particularly limited, but is preferably included in an amount of 10 mass% or more based on the total mass of the curable white silicone composition, more preferably 20 mass% or more, even more preferably 30 mass% or more, and particularly preferably 40 mass% or more. In a preferred embodiment, component (A) is included in an amount of 80 mass% or less based on the total mass of the curable white silicone composition, preferably 70 mass% or less, and more preferably 60 mass% or less.

[0069] (A) The component may contain aryl groups depending on the purpose. By containing aryl groups, a white cured product can be obtained that has high hardness and strength and is easy to handle, although light resistance is inferior compared to when it does not contain aryl groups. The content of aryl groups in the total component (A) (mol% of aryl groups in the total silicon atom bonded functional groups of the organopolysiloxane) may be 20 mol% or more, more preferably 40 mol% or more of the total component (A).

[0070] (B) Cerium-containing organopolysiloxane

[0071] The curable white silicone composition according to the present invention comprises a cerium-containing organopolysiloxane as component (B). (B) The cerium-containing organopolysiloxane may be prepared, for example, by the reaction of a cerium salt of cerium chloride or a carboxylic acid with an alkali metal salt of a silanol group-containing organopolysiloxane. Accordingly, in this specification, the term "cerium-containing organopolysiloxane" may mean that the silanol group-containing organopolysiloxane is obtained by reacting a silanol group-containing organopolysiloxane with a cerium salt, and that the cerium atom is chemically bonded to the silanol group of the organopolysiloxane.

[0072] Examples of cerium salts of the above carboxylic acids include cerium 2-ethylhexanoate, cerium naphthenate, cerium oleate, cerium laurate, and cerium stearate. Examples of cerium chloride include cerium trichloride.

[0073] In addition, alkali metal salts of the above-mentioned silanol group-containing organopolysiloxane include a potassium salt of a diorganopolysiloxane in which both ends of the molecular chain are blocked by silanol groups, a sodium salt of a diorganopolysiloxane in which both ends of the molecular chain are blocked by silanol groups, a potassium salt of a diorganopolysiloxane in which one end of the molecular chain is blocked by a silanol group and the other end of the molecular chain is blocked by a triorganosiloxy group, and a sodium salt of a diorganopolysiloxane in which one end of the molecular chain is blocked by a silanol group and the other end of the molecular chain is blocked by a triorganosiloxy group. Meanwhile, groups bonded to silicon atoms in this organopolysiloxane include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl groups; aryl 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, and bromine atoms.

[0074] The above reaction is carried out at room temperature or by heating in alcohols such as methanol, ethanol, isopropanol, and butanol; aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as hexane and heptane; and organic solvents such as mineral split, ligroin, and petroleum ether. Additionally, it is desirable to remove organic solvents or low-boiling point components from the resulting reaction product, or to filter out precipitates as needed. Furthermore, to promote this reaction, dialkylformamide, hexaalkylphosphamide, etc., may be added. It is preferable that the content of cerium atoms in the cerium-containing organopolysiloxane prepared in this manner be within the range of 0.1 to 15 mass%.

[0075] The inventors of the present invention have completed the present invention by discovering that a cured product of a curable white silicone composition containing (B) cerium-containing organopolysiloxane can exhibit excellent light resistance while maintaining a high light reflectance. Although the reason why (B) cerium-containing organopolysiloxane can improve the light resistance of the cured product of the curable white silicone composition has not been revealed at this stage, it is believed that this is because (B) cerium-containing organopolysiloxane has the effect of inhibiting photocatalytic activity by white pigments.

[0076] (B) The content of the component is not particularly limited, but preferably, the amount of cerium atoms in mass is in the range of 0.5 to 1,000 ppm, and more preferably, the amount is in the range of 1 to 500 ppm.

[0077] (C) White pigment

[0078] The curable white silicone composition according to the present invention comprises a white pigment as component (C). The white pigment (C) may comprise one type of white pigment (C) and may comprise two or more types of white pigments (C).

[0079] (C) Examples of white pigments include metal oxides such as titanium oxide, aluminum oxide, zinc oxide, zirconium oxide, and magnesium oxide; hollow fillers such as glass balloons and glass beads; and other examples include barium sulfate, zinc sulfate, barium titanate, aluminum nitride, boron nitride, and antimony oxide. Titanium oxide is preferred due to its high light reflectivity and opacity. Additionally, aluminum oxide, zinc oxide, and barium titanate are preferred due to their high light reflectivity in the UV region.

[0080] White pigments may additionally undergo surface treatment for the purpose of increasing reflectance, whiteness, and lightfastness. Examples of known surface treatments include aluminum oxide, aluminum hydroxide, silica, zinc oxide, zirconium oxide, organic compounds, and siloxane treatment. Organic compounds are not particularly limited, but examples include polyalcohols, alkanolamines or their derivatives, organosilicon compounds such as organosilicones, higher fatty acids or their metal salts, and organometallic compounds. As for the surface treatment method, it is not particularly limited as long as it is a known method, and methods such as (1) mixing a pre-surface-treated white pigment into a silicone composition, and (2) adding a surface treatment agent to the silicone composition separately from the white pigment and reacting the white pigment within the composition may be used.

[0081] The surface treatment of the white pigment is not particularly limited as long as it is of a known type, but it is particularly preferable that it does not contain silica, as this results in particularly excellent light resistance of the resulting white cured product. Furthermore, it is particularly preferable that it does not include organic treatment, as this allows the reflectance of the resulting white cured product to be maintained at a high level after a heat resistance test. The surface treatment of the white pigment can be analyzed using analytical methods such as scanning electron microscopy (SEM-EDX) or inductively coupled plasma mass spectrometry (ICP-MS).

[0082] (C) The average particle size or shape of the component is not limited, but the average particle size is preferably within the range of 0.05 to 10 μm, more preferably within the range of 0.1 to 5 μm, and particularly preferably within the range of 0.15 to 3 μm. Meanwhile, in this specification, the average particle size refers to the particle size at 50% of the cumulative value in the particle size distribution obtained by the laser diffraction and scattering method.

[0083] In the present composition, the content of component (C) is not particularly limited, but is preferably 10 mass% or more, more preferably 20 mass% or more, even more preferably 30 mass% or more, and particularly preferably 40 mass% or more with respect to the total mass of the present composition. This is because the light reflectance of the resulting cured product is good when the content of component (C) is above the lower limit. In addition, in a preferred embodiment, component (C) is included in an amount of 80 mass% or less based on the total mass of the present composition, preferably 70 mass% or less, and more preferably 60 mass% or less.

[0084] (D) Curing catalyst

[0085] The curing catalyst of component (D) is a catalytic component for curing the organopolysiloxane of component (A). The curable white silicone composition according to the present invention may include one type of curing catalyst (D), or two or more types of curing catalysts (D).

[0086] The curing catalyst of component (D) may preferably be selected from (d1) a hydrosilylation reaction catalyst, (d2) a peroxide, and (d3) a high-energy beam curing catalyst. The curable white silicone composition according to the present invention may include only one of these types, or may use a combination of two or more of these types.

[0087] (d1) A catalyst for a hydrosilylation reaction is a catalyst for promoting the curing of a silicon composition of the hydrosilylation reaction curing type. Examples of such (d1) components include platinum-based catalysts such as chloroplatinic acid, an alcoholic solution of chloroplatinic acid, a complex of platinum and olefin, a complex of platinum and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, and a platinum-supported powder; palladium-based catalysts such as tetrakis(triphenylphosphine)palladium, palladium black, and a mixture with triphenylphosphine; additionally, rhodium-based catalysts may be provided, and it is particularly preferable that the catalyst be a platinum-based catalyst.

[0088] (d1) The amount of component is the amount of catalyst required for curing component (A), and is not particularly limited, but, for example, when a platinum-based catalyst is used, the amount of platinum metal included in the platinum-based catalyst is preferably in the range of 0.01 to 1000 ppm by weight in the silicon composition, and is particularly preferably in the range of 0.1 to 500 ppm.

[0089] (d2) Examples of peroxides include alkyl peroxides, diacyl peroxides, ester peroxides, or carbonates peroxides.

[0090] Examples of alkyl peroxides include dicumyl peroxide, di-tert-butyl peroxide, di-tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 1,3-bis(tert-butylperoxyisopropyl)benzene, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonan, etc.

[0091] Examples of diacyl peroxides include benzoyl peroxide, lauroyl peroxide, and decanoyl peroxide. Peroxide esters include, for example, 1,1,3,3-tetramethylbutylperoxyneodecanoate, α-cumylperoxyneodecanoate, tert-butylperoxyneoheptanoate, tert-butylperoxypivalate, tert-hexylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, tert-amylperoxy-2-ethylhexanoate, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyisobutylate, di-tert-butylperoxyhexahydroterephthalate, tert-amylperoxy 3,5,5-trimethylhexanoate, and tert-butylperoxy Examples include 3,5,5-trimethylhexanoate, tert-butylperoxyacetate, tert-butylperoxybenzoate, and di-butylperoxytrimethyladipate.

[0092] Examples of carbonates peroxide include di-3-methoxybutylperoxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, diisopropylperoxycarbonate, tert-butylperoxyisopropylcarbonate, di(4-tert-butylcyclohexyl)peroxydicarbonate, dicetylperoxydicarbonate, dimyristylperoxydicarbonate, etc.

[0093] (d2) The amount of component is the amount of catalyst required for curing component (A), and is not particularly limited, but may be in the range of 0.05 to 10 parts by mass with respect to 100 parts by mass of the organopolysiloxane component of component (A), and preferably in the range of 0.10 to 5.0 parts by mass.

[0094] (d3) As a high-energy radiation curing catalyst, compounds known in the past to generate radicals by irradiation with high-energy radiation including ultraviolet rays, such as carbonyl compounds, organic sulfur compounds, azo compounds, etc., may be appropriately selected and used. Specifically, acetophenone, propiophenone, benzophenone, xanthol, fluorene, benzaldehyde, anthraquinone, triphenylamine, 4-methylacetophenone, 3-pentylacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone, 4-allylacetophenone, p-diacetylbenzene, 3-methoxybenzophenone, 4-methylbenzophenone, 4-chlorobenzophenone, 4,4-dimethoxybenzophenone, 4-chloro-4'-benzylbenzophenone, 3-chloroxanthone, 3,9-dichloroxanthone, 3-chloro-8-nonylxanthone, benzoin, benzoin methyl ether, benzoin butyl ether, bis(4-dimethylaminophenyl)ketone, benzyl methoxyketal, Examples include 2-chlorothioxantone, diethylacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl[4-(methylthio)phenyl]2-morphorino-1-propanone, 2,2-dimethoxy-2-phenylacetophenone, diethoxyacetophenone, etc.

[0095] (d3) The amount of component is the amount of catalyst required for curing component (A), and is not particularly limited, but may be in the range of 0.05 to 10 parts by mass with respect to 100 parts by mass of the organopolysiloxane component of component (A), and preferably in the range of 0.10 to 5.0 parts by mass.

[0096] (E) Organohydrogenpolysiloxane

[0097] (D) When the curing catalyst of component (D) includes a catalyst for a hydrosilylation reaction (a1), that is, when the curing of the curable white silicone composition according to the present invention includes a hydrosilylation reaction, the composition of the present invention may include an organohydrogenpolysiloxane having at least two silicon atom bonded hydrogen atoms in one molecule of component (E) as a crosslinking agent. For component (E), one type of organohydrogenpolysiloxane may be used, or two or more types of organohydrogenpolysiloxanes may be used in combination.

[0098] (E) The molecular structure of the component is exemplified by a linear structure, a linear structure with some branches, a branched structure, a cyclic structure, and a three-dimensional network structure, and preferably a linear structure. (E) The component may use an organohydrogenpolysiloxane of one type of structure, or may use a combination of two or more types of organohydrogenpolysiloxanes.

[0099] (E) The silicon atom-bonded hydrogen atoms of the component may be contained at both ends of the molecular chain, or in side chains other than both ends of the molecular chain. (E) The groups bonded to silicon atoms other than hydrogen atoms in the component include: alkyl groups having 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 having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl groups; and aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl groups. Examples of groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine atoms, chlorine atoms, or bromine atoms are provided. Meanwhile, silicon atoms in component (E) may have a small amount of alkoxy groups such as hydroxyl groups, methoxy groups, or ethoxy groups, to the extent that the purpose of the present invention is not impaired.

[0100] Such (E) components include: dimethylpolysiloxane with dimethylhydrogensiloxy group blocking at both ends of the molecular chain; dimethylsiloxane-methylphenylsiloxane copolymer with dimethylhydrogensiloxy group blocking at both ends of the molecular chain; dimethylsiloxane-methylhydrogensiloxane copolymer with dimethylhydrogensiloxy group blocking at both ends of the molecular chain; methylhydrogenpolysiloxane with trimethylsiloxy group blocking at both ends of the molecular chain; dimethylsiloxane-methylhydrogensiloxane copolymer with trimethylsiloxy group blocking at both ends of the molecular chain; and H(CH3)2SiO 1 / 2 Units and SiO 4 / 2 Organopolysiloxanes composed of units, and H(CH3)2SiO 1 / 2 Unit, (CH3)3SiO 1 / 2 Units and SiO 4 / 2 An organopolysiloxane consisting of units is exemplified.

[0101] In a preferred embodiment, component (E) is

[0102] General formula (E-1): R 23SiO(HR 2 SiO) n OSiR 2 3

[0103] (during food, R 2 is R 1 It can be represented as (same as, and n is a number in the range of 1 to 100, preferably 10 to 90, more preferably 20 to 80, and even more preferably 30 to 70).

[0104] In another preferred embodiment, component (E) is

[0105] Average unit formula (E-2): (HR 2 2SiO 1 / 2 ) p (R 2 SiO 3 / 2 ) q

[0106] (during food, R 2 is R 1 It can be represented as (same as, and p, q is a number in the range of 1 to 100, preferably 10 to 90, more preferably 20 to 80, even more preferably 30 to 70).

[0107] (E) The component may include an aryl group, preferably a phenyl group. In this case, the content of the aryl group (mol% of the aryl group in the total silicon atom bonded functional group of component (E)) can be designed as desired, but may be 1 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and 40 mol% or less, preferably 30 mol% or less, more preferably 25 mol% or less, and preferentially 20 mol% or less. Meanwhile, the content of the aryl group can be determined by analysis such as Fourier transform infrared spectrophotometry (FT-IR) or nuclear magnetic resonance (NMR).

[0108] When the curable white silicone composition of the present invention includes component (E), the content of component (E) is not particularly limited, but for example, it may be an amount such that the silicon atom bonded hydrogen atoms in the component are 0.1 to 10 moles for every 1 mole of silicon atom bonded alkenyl groups in component (A), preferably 0.5 to 5 moles, and particularly 0.8 to 1.2 moles. Meanwhile, the content of silicon atom bonded hydrogen atoms in component (E) can be determined by analysis such as Fourier transform infrared spectrophotometry (FT-IR) or nuclear magnetic resonance (NMR).

[0109] In addition, in another embodiment, when the curable white silicone composition of the present invention comprises component (E), the content of component (E) is in the range of 0.1 to 20 mass% with respect to the total mass of the composition of the present invention, and preferably in the range of 0.5 to 15 mass%.

[0110] The curable white silicone composition of the present invention may incorporate any components within a range that does not impair the purpose of the present invention. Examples of such optional components include, for instance, acetylene compounds, organic phosphorus compounds, vinyl group-containing siloxane compounds, hydrosilylation reaction inhibitors; inorganic fillers other than white pigments, or inorganic fillers formed by hydrophobically treating the surface of an inorganic filler with an organic silicon compound, organopolysiloxanes that do not contain silicon atom-bonded hydrogen atoms and silicon atom-bonded alkenyl groups, tackifiers, heat resistance agents, cold resistance agents, thermal conductivity fillers, flame retardants, thixotropic agents, phosphors, solvents, etc.

[0111] The hydrosilylation reaction inhibitor is a component for inhibiting the hydrosilylation reaction of the silicon composition, and specifically, examples include reaction inhibitors such as acetylene-based, amine-based, carboxylic acid ester-based, and phosphite ester-based inhibitors such as ethinylcyclohexanol. The amount of reaction inhibitor added is typically 0.001 to 5 mass% of the total composition.

[0112] Examples of inorganic fillers include fumed silica, crystalline silica, precipitated silica, silsesquioxane, magnesium oxide, iron oxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, zinc carbonate, layered mica, diatomaceous earth, glass fiber, etc.; fillers in which these fillers have been surface-hydrophobized with organosilicon compounds such as organoalkoxysilane compounds, organochlorosilane compounds, organosilazanes, and low molecular weight siloxane compounds. Additionally, silicone rubber powder, silicone resin powder, etc. may be incorporated. However, the amount of inorganic filler incorporated may be 40 mass% or less of the composition, 30 mass% or less, 20 mass% or less, and is particularly preferably 10 mass% or less.

[0113] Examples of phosphors include yellow, red, green, and blue emitting phosphors composed of oxide-based phosphors, oxynitride-based phosphors, nitride-based phosphors, sulfide-based phosphors, oxysulfide-based phosphors, fluoride-based phosphors, etc., which are widely used in light-emitting diodes (LEDs), and mixtures of at least two of these. Examples of oxide-based phosphors include YAG-based green to yellow emitting phosphors of the yttrium, aluminum, and garnet type containing cerium ions, TAG-based yellow emitting phosphors of the terbium, aluminum, and garnet type containing cerium ions, and silicate-based green to yellow emitting phosphors containing cerium or europium ions. Examples of oxynitride-based phosphors include sialon-based red to green chromogenic phosphors of the silicon, aluminum, oxygen, and nitrogen type containing europium ions. Examples of nitride-based phosphors include calcium, strontium, aluminum, silicon, and nitrogen-based CASN-based red emitting phosphors containing europium ions. Examples of sulfide-based phosphors include ZnS-based green-emitting phosphors containing copper or aluminum ions. Examples of oxosulfide-based phosphors include Y2O2S-based red-emitting phosphors containing europium ions. Examples of fluoride-based phosphors include KSF phosphors (K2SiF6:Mn 4+ Examples include ) etc.

[0114] Adhesion promoters include, for example, epoxy group-containing alkoxysilanes, acrylic group-containing alkoxysilanes, amino group-containing alkoxysilanes, reaction condensates of silane coupling agents, organic titanium compounds, organic aluminum compounds, organic zirconium compounds, and ethyl polysilicate [average molecular formula Si m O (m-1) (OC2H5) 2(m+1) Examples include (m in the formula is 5 on average)], etc. Among these, the above-mentioned organic titanium compounds, reaction condensates of silane coupling agents, and ethyl polysilicate [average molecular formula Si m O (m-1) (OC2H5) 2(m+1)It is preferable to use [m in the formula is 5 on average, SiO2 content 40 wt%, viscosity 5 mPa·s] or a combination thereof.

[0115] The curable white silicone composition of the present invention can be prepared by mixing each component. The method of mixing each component may be any known conventional method and is not particularly limited, but a uniform mixture is typically obtained by simple stirring. In addition, when a solid component such as an inorganic filler is included as an optional component, mixing using a mixing device is more preferable. Examples of such a mixing device are not particularly limited, but include a single-axis or two-axis continuous mixer, a two-roll mixer, a Roth mixer, a Hobart mixer, a dental mixer, a planetary mixer, a kneader mixer, a Henschel mixer, etc.

[0116] The curable white silicone composition of the present invention provides a cured product having a high spectral reflectance in the visible light region when cured, preferably at a thickness of 250 μm, the light reflectance in the visible wavelength region is preferably 90% or more, and more preferably 95% or more.

[0117] Since the cured product obtained by curing the curable white silicon composition of the present invention has a high light reflectivity and excellent light resistance, the curable white silicon composition of the present invention can be preferably used as a light reflector, particularly as a light reflector for a photo-semiconductor device.

[0118] [Reflector for Optical Semiconductor Devices]

[0119] The present invention also relates to a reflector for an opto-semiconductor device obtained by curing the curable white silicon composition of the present invention. Since the reflector for an opto-semiconductor device of the present invention is obtained by curing the curable white silicon composition of the present invention, it has a high light reflectivity and excellent light resistance. The opto-semiconductor device is not particularly limited, but examples include a light-emitting diode (LED), a semiconductor laser, a photodiode, a phototransistor, a solid-state imager, and a light-receiving body for a photocoupler, and it is particularly preferred to be a light-emitting diode (LED).

[0120] [Optical semiconductor device]

[0121] The optical semiconductor device of the present invention comprises a reflector for the optical semiconductor device of the present invention. Examples of such an optical semiconductor device include a light-emitting diode (LED), a semiconductor laser, a photodiode, a phototransistor, a solid-state imager, and a light-receiving body for a photocoupler, and it is particularly preferable that it be a light-emitting diode (LED). Since the optical semiconductor device of the present invention comprises a reflector for the optical semiconductor device of the present invention with excellent reflectivity and light resistance, it has excellent luminous efficiency and reliability.

[0122] [Example]

[0123] The curable white silicone composition of the present invention will be explained in detail by the following examples and comparative examples.

[0124] In the following examples and comparative examples, the raw material components listed below were used. In the following, Me represents a methyl group, Vi represents a vinyl group, and Ph represents a phenyl group.

[0125] Component a-1: Average structural formula (ViMe2SiO2) 1 / 2 ) 10 (Me3SiO 1 / 2 ) 40 (SiO 4 / 2 ) 50 Resin-type alkenyl group-containing organopolysiloxane represented by

[0126] Component a-2: General formula ViMe2SiO(Me2SiO) 150 linear alkenyl group-containing organopolysiloxane designated as OSiViMe2

[0127] Component a-3: Average structural formula (ViMe2SiO2) 1 / 2 ) 25 (PhSiO 3 / 2 ) 75 Resin-type alkenyl group-containing organopolysiloxane represented by

[0128] Component a-4: General formula ViMe2SiO(PhMeSiO 2 / 2 ) 20 linear alkenyl group-containing organopolysiloxane represented by SiOMe2Vi

[0129] Component b-1: Cerium-containing dimethylpolysiloxane with a cerium content of 0.5 mass%

[0130] Component c-1: Titanium oxide (average particle size 0.25 μm, PX3788, Sakai Kagaku Kogyo Co.)

[0131] Component C-2: Zinc oxide (average particle size 0.6 μm, Sakai Kagaku Kogyo Co.)

[0132] Component c-3: Titanium oxide (average particle size 0.21 μm, CR-63, Ishihara Sangyo Co.)

[0133] Component c-4: Titanium oxide (average particle size 0.3 μm, KRONOS2360, KRONOS)

[0134] Component c-5: Titanium oxide (average particle size 0.25 μm, CR-90, Ishihara Sangyo Co.)

[0135] Component C-6: Titanium oxide (average particle size 0.21 μm, PF-691, Ishihara Sangyo Co.)

[0136] Component c-7: Titanium oxide (average particle size 0.21 μm, CR-60, Ishihara Sangyo Co.)

[0137] Component C-8: Titanium oxide (average particle size 0.21 μm, CR-60-2, Ishihara Sangyo Co.)

[0138] Component c-9: Titanium oxide (average particle size 0.25 μm, CR-97, Ishihara Sangyo Co.)

[0139] Component C-10: Titanium oxide (average particle size 0.21 μm, JR-405, Teika Co.)

[0140] Component c-11: Titanium oxide (average particle size 0.21 μm, JR-405S, Teika Co.)

[0141] Component C-12: Titanium oxide (average particle size 0.26 μm, TCR-10, Sakai Kagaku Kogyo Co.)

[0142] Component C-13: Zirconium oxide (average particle size 1.5 to 2.5 μm, SPZ, Daiichi Kigenso Kakaku Co.)

[0143] Component d: Complex of platinum with a platinum concentration of 4.0 mass% and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane

[0144] Component e-1: General formula Me3SiO(HMeSiO) 50 Organohydrogenpolysiloxane designated as OSiMe3

[0145] Component e-2: Average structural formula (HMe2SiO2) 1 / 2 ) 60 (PhSiO 3 / 2 ) 40 Organohydrogenpolysiloxane represented by

[0146] Ingredient f: Ethinylcyclohexanol

[0147] [Example 1 and Comparative Example 1]

[0148] Each component was mixed according to the composition (mass%) shown in Table 1, and a curable white silicone composition was prepared.

[0149] [Presence of crack]

[0150] The curable white silicon compositions of Example 1 and Comparative Example 1 were applied onto a glass substrate and cured by heating at 150°C for 2 hours to obtain a cured product with a thickness of 250 μm. A high-pressure mercury lamp at 140 mW / cm² was applied to the obtained cured product. 2 After irradiating with ultraviolet light at a UV intensity for 10 hours, the appearance was checked to determine the presence or absence of cracks. The results are shown in Table 1 below.

[0151] ingredient Example 1 Comparative Example 1 a-1 17.34 17.44 a-2 34.88 34.88 b-1 0.1 - c-1 45.02 45.02 e-1 2.64 2.64 f 0.02 0.02 total 100 100 d Catalyst amount Catalyst amount evaluation crack doesn't exist is available

[0152] [Examples 2 to 3 and Comparative Examples 2 to 3]

[0153] Each component was mixed according to the composition (mass%) shown in Table 2, and a curable silicone composition was prepared.

[0154] [reflectivity]

[0155] The curable white silicon compositions of Examples 2 and 3 and Comparative Examples 2 and 3 were applied onto a glass substrate and cured by heating at 150°C for 2 hours to obtain a cured product with a thickness of 250 μm. The reflectance of light was measured using the obtained cured product (Color Difference CM-5, Konica Minolta). The results are shown in Table 2 below.

[0156] [Lightfastness Test]

[0157] The curable white silicon compositions of Examples 2 and 3 and Comparative Examples 2 and 3 were applied onto a glass substrate and cured by heating at 150°C for 2 hours to obtain a cured product with a thickness of 250 μm. A high-pressure mercury lamp at 140 mW / cm² was applied to the obtained cured product. 2 Ultraviolet light was irradiated at a UV intensity, and the time until cracks occurred in the cured material was measured. The results are shown in Table 2 below.

[0158] ingredient Example 2 Example 3 Comparative Example 2 Comparative Example 3 a-1 15.8 15.8 15.9 15.9 a-2 31.7 31.7 31.7 31.7 b-1 0.1 0.1 - - c-1 50 - 50 - c-2 - 50 - 50 e-1 2.4 2.4 2.4 2.4 f 0.02 0.02 0.02 0.02 total 100 100 100 100 d Catalyst amount Catalyst amount Catalyst amount Catalyst amount evaluation reflectivity(%) 97 96 97 96 Lightfastness (time) 20 15 10 8

[0159] [Examples 4 to 15]

[0160] A cured product was prepared in the same manner as in Example 1, except that the C component described in Example 1 was changed to the white pigment described in Table 3 below, and the reflectance and light resistance were evaluated in the same manner. The results are shown in Table 3. In the table, regarding the surface treatment of titanium oxide, Al indicates that the titanium oxide is surface-treated with aluminum hydroxide or aluminum oxide (alumina), Si indicates that the titanium oxide is surface-treated with silica, and Zr indicates that the titanium oxide is surface-treated with zirconium oxide.

[0161] Component C Surface treatment of titanium oxide reflectivity% Lightfastness (time) Example 1 c-1 Al, Si, organic matter 97 20 Example 4 c-2 - 93 15 Example 5 c-3 Al, Si, organic matter 95 15 Example 6 c-4 Al, Si, organic matter 95 20 Example 7 c-5 Al, Si 95 15 Example 8 c-6 Al, Si, organic matter 95 15 Example 9 c-7 Al 95 32 Example 10 c-8 Al, organic matter 95 32 Example 11 c-9 Al, Zr 94 32 Example 12 c-10 Al 93 32 Example 13 c-11 Al, organic matter 93 32 Example 14 c-12 Al, Zn 93 32 Example 15 c-13 - 91 32

[0162] [Example 16, Comparative Example 4]

[0163] Preparation of cerium-containing phenylsilicon b-2

[0164] Average formula: HO(PhMeSiO) 5.4 To a phenylmethyloligosiloxane with a molecular chain end silanol group blocking indicated by H, an amount of sodium methoxide / methanol solution equivalent to the silanol group (28 mass%) and an amount of toluene equal to the amount of said phenylmethyloligosiloxane with a molecular chain end silanol group blocking were added, and the mixture was heated to 110°C at atmospheric pressure to remove the methanol, thereby obtaining a toluene solution of the corresponding sodium silanolate. Subsequently, at room temperature, 1 / 2 equivalent of trimethylchlorosilane relative to the silanol group was added dropwise, and average formula: Me3SiO(PhMeSiO) 5.4 A toluene solution of sodium silanolate, denoted as Na, was obtained.

[0165] Next, a toluene solution of the sodium silanolate was added dropwise to a mixture of cerium trichloride, toluene, and methoxyisopropanol while stirring, and after stirring at room temperature for 1 hour, the salt was filtered. The filtrate was removed by heating under reduced pressure, and cerium-containing phenylsilicone (b-2) with a cerium content of 9.5 mass% as determined by fluorescent X-ray analysis was prepared.

[0166] Each component was mixed according to the composition (mass%) shown in Table 4 to prepare a curable silicone composition. Reflectance and light resistance were evaluated in the same manner as in the examples and comparative examples described above. The results are shown in Table 4 below.

[0167] ingredient Example 16 Comparative Example 4 a-3 33 33.5 a-4 10 10 b-2 0.5 - c-1 45 45 e-2 11.5 11.5 total 100 100 d Catalyst amount Catalyst amount evaluation reflectivity(%) 92 92 Lightfastness (min) 40 20 Industrial applicability

[0168] The curable white silicon composition of the present invention is useful as a reflector for opto-semiconductor devices, particularly as a reflector for opto-semiconductor devices such as light-emitting diodes (LEDs), semiconductor lasers, photodiodes, phototransistors, solid-state imaging, and photocouplers, light emitters and light receivers.

Claims

Claim 1 A curable white silicon composition used for manufacturing a reflector for an opto-semiconductor device, comprising (A) an organopolysiloxane having at least two alkenyl groups in one molecule, (B) a cerium-containing organopolysiloxane, (C) a white pigment, and (D) a curing catalyst, wherein the content of (C) the white pigment is 10 to 80 mass% with respect to the total mass of the composition. Claim 2 A curable white silicone composition according to claim 1, wherein the amount of cerium atoms in the (B) cerium-containing organopolysiloxane is 0.5 to 1,000 ppm with respect to the total mass of the composition. Claim 3 A curable white silicone composition according to claim 1, wherein the average particle size of the (C) white pigment is 0.1 to 5 μm. Claim 4 A curable white silicone composition according to claim 1, wherein the (C) white pigment comprises titanium oxide that has not been surface-treated with silica. Claim 5 A curable white silicon composition according to claim 1, wherein the (D) curing catalyst comprises a catalyst for a hydrosilylation reaction. Claim 6 In claim 1, the above (A) organopolysiloxane comprises a resin-type organopolysiloxane, a curable white silicone composition. Claim 7 In paragraph 6, the resin-type organopolysiloxane is (A-2) average unit formula: (R 1 3SiO 1 / 2 ) f (SiO 4 / 2 ) g (XO 1 / 2 ) h (during food, R 1 is a monovalent hydrocarbon group with the same or different halogen substitution or non-substitution, provided that at least two R 1 A curable white silicone composition represented by , where is an alkenyl group, f is an integer from 5 to 1,000, g is an integer from 5 to 1,000, X is a hydrogen atom or an alkyl group, and h is an integer from 0 to 10. Claim 8 A curable white silicone composition according to any one of claims 1 to 7, wherein (A) the organopolysiloxane comprises a resin-type organopolysiloxane and a linear-type organopolysiloxane in an amount such that the ratio of the linear-type organopolysiloxane to the resin-type organopolysiloxane content is 1 or more. Claim 9 A reflector for an optical semiconductor device comprising a cured product of a curable white silicon composition according to any one of claims 1 to 7. Claim 10 An optical semiconductor device having a reflective material for an optical semiconductor device according to claim 9. Claim 11 delete

Images