JP6998905B2 - Additive-curable silicone compositions, cured products and opto-semiconductor devices - Google Patents

Description

The present invention relates to an addition-curable silicone resin composition, a cured product thereof, and an optical semiconductor device.

It has been proposed to use a silicone resin as a sealing material for a light emitting diode (hereinafter referred to as "LED") element (Patent Documents 1 to 3). Silicone resins are mainly used for blue LEDs and white LEDs because they are superior in heat resistance, weather resistance, and discoloration resistance to conventional epoxy resins.
However, in recent years, the temperature around the optical element rises with the increase in the amount of electricity supplied to the LED, and the long-term reliability test is often carried out in a high temperature environment. Under high temperature environment conditions, the deterioration of the silicone encapsulant progresses, so that the silicone resin may crack or the light transmittance may decrease due to discoloration. In order to deal with the above problems, Patent Document 4 reports a heat-resistant silicone rubber composition containing a rare earth salt mixture of 2-ethylhexanoic acid, and has a total light transmittance of a sheet having a thickness of 2 mm at a wavelength of 600 nm. It is reported to be 90% or more. However, this heat-resistant silicone rubber composition has a problem that the light transmission of short-wavelength light in the vicinity of a wavelength of 400 nm is inferior.

Japanese Unexamined Patent Publication No. 11-1619 Japanese Unexamined Patent Publication No. 2002-265787 Japanese Unexamined Patent Publication No. 2004-186168 Japanese Patent No. 542755

INDUSTRIAL APPLICABILITY The present invention has been made to solve the above problems, and provides an addition-curable silicone composition having excellent light transmittance in the vicinity of a wavelength of 400 nm even when used under high temperature conditions, and having little change in hardness and mass loss. The purpose is.

（式中、Ｒ^４は同種又は異種の一価炭化水素基、ｎは１～１００の正数、ｍは２～２０の正数である）
を含有する付加硬化型シリコーン組成物を提供する。 In order to achieve the above problems, in the present invention,
(A) A linear organopolysiloxane having at least two alkenyl groups bonded to a silicon atom in one molecule and having a viscosity at 25 ° C. of 0.05 to 100 Pa · s.
(B) A three-dimensional network organopolysiloxane resin represented by the following average unit formula (1) and which is waxy or solid at 23 ° C.
(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ¹ SiO _3/2 ) _e (R ² SiO) _3/2 ) _f (SiO ₂ ) _g (1)
(In the formula, R ¹ independently represents an alkenyl group, R ² independently represents a monovalent hydrocarbon group without an addition-reactive carbon-carbon double bond, and at least 80 mol% of all R ² is a methyl group. 1> a ≧ 0, 1> b ≧ 0, 1> c ≧ 0, 1> d ≧ 0, 1> e ≧ 0, 1> f ≧ 0 and 1> g ≧ 0, and b + c + e> 0, It is a number that satisfies e + f + g> 0 and a + b + c + d + e + f + g = 1.)
(C) Organohydrogenpolysiloxane, which has a hydrogen atom bonded to at least two silicon atoms per molecule and does not have an addition-reactive carbon-carbon double bond.
(D) Hydrosilylation catalyst containing platinum group metal, and (E) Reaction product of the following (i) and (ii): Amount in which the content of cerium atom is 10 to 500 ppm with respect to the entire composition (i). ) Cerium carboxylate represented by the following formula (2),
(R ³ CO ₂ ) ₃ Ce (2)
(In the formula, R ³ is a monovalent hydrocarbon group of the same kind or a different kind)
(Ii) A siloxane compound having a carboxylic acid represented by the following formula (3)

(In the formula, ^R4 is a monovalent hydrocarbon group of the same kind or a different kind, n is a positive number of 1 to 100, and m is a positive number of 2 to 20).
Provided is an addition-curable silicone composition containing.

This addition-curable silicone composition provides a cured product having excellent light transmittance in the vicinity of a wavelength of 400 nm even when used under high temperature conditions, and having little change in hardness and mass loss.

The present invention also provides a cured product of the addition-curable silicone composition.
This cured product has excellent light transmission at a wavelength of around 400 nm when used under high temperature conditions, and has little hardness change and mass loss.

This cured product preferably has a transmittance of light having a wavelength of 400 nm at an optical path length of 2 mm or more of 85% or more.
The cured product having the above-mentioned predetermined transmittance is superior in light transmittance in the vicinity of a wavelength of 400 nm when used under high temperature conditions.

The cured product preferably has a mass loss rate of 10% or less after being stored at 270 ° C. for 100 hours.
The cured product having the above-mentioned predetermined mass reduction rate has less hardness change and mass loss when used under high temperature conditions.

Further, the present invention provides an optical semiconductor device sealed with the above-mentioned cured silicone product.
This optical semiconductor device is highly reliable.

The addition-curable silicone composition of the present invention provides a cured product having excellent light transmittance in the vicinity of a wavelength of 400 nm even when used under high temperature conditions, and having little change in hardness and mass loss. Therefore, the addition-curable silicone resin composition of the present invention is a material for protecting / encapsulating an LED element, a material for changing / adjusting a wavelength, a constituent material for a lens, and a material for other optical devices or optical components. Especially useful as.

As described above, there has been a demand for the development of an addition-curable silicone composition having excellent light transmittance in the vicinity of a wavelength of 400 nm and having little change in hardness and mass reduction when used under high temperature conditions.

As a result of diligent research, the present inventors can achieve the above-mentioned problems if the addition-curable silicone resin composition contains the following components (A) to (E), and is suitable as a material for LEDs and the like. The present invention was completed.

（式中、Ｒ^４は同種又は異種の一価炭化水素基、ｎは１～１００の正数、ｍは２～２０の正数である）
を含有する付加硬化型シリコーン組成物である。 That is, the present invention
(A) A linear organopolysiloxane having at least two alkenyl groups bonded to a silicon atom in one molecule and having a viscosity at 25 ° C. of 0.05 to 100 Pa · s.
(B) A three-dimensional network organopolysiloxane resin represented by the following average unit formula (1) and which is waxy or solid at 23 ° C.
(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ¹ SiO _3/2 ) _e (R ² SiO) _3/2 ) _f (SiO ₂ ) _g (1)
(In the formula, R ¹ independently represents an alkenyl group, R ² independently represents a monovalent hydrocarbon group without an addition-reactive carbon-carbon double bond, and at least 80 mol% of all R ² is a methyl group. 1> a ≧ 0, 1> b ≧ 0, 1> c ≧ 0, 1> d ≧ 0, 1> e ≧ 0, 1> f ≧ 0 and 1> g ≧ 0, and b + c + e> 0, It is a number that satisfies e + f + g> 0 and a + b + c + d + e + f + g = 1.)
(C) Organohydrogenpolysiloxane, which has a hydrogen atom bonded to at least two silicon atoms per molecule and does not have an addition-reactive carbon-carbon double bond.
(D) Hydrosilylation catalyst containing platinum group metal, and (E) Reaction product of the following (i) and (ii): Amount in which the content of cerium atom is 10 to 500 ppm with respect to the entire composition (i). ) Cerium carboxylate represented by the following formula (2),
(R ³ CO ₂ ) ₃ Ce (2)
(In the formula, R ³ is a monovalent hydrocarbon group of the same kind or a different kind)
(Ii) A siloxane compound having a carboxylic acid represented by the following formula (3)

(In the formula, ^R4 is a monovalent hydrocarbon group of the same kind or a different kind, n is a positive number of 1 to 100, and m is a positive number of 2 to 20).
It is an addition curable silicone composition containing.

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

<Additional curable silicone composition>
Hereinafter, each component will be described in detail.
[(A) component]
The component (A) is a component that is the main skeleton of the composition of the present invention, and is a linear organopolysiloxane having at least two alkenyl groups in one molecule.
The viscosity of the component (A) is 0.05 to 100 Pa · s, preferably 0.1 to 50 Pa · s, and more preferably 0.5 to 10 Pa · s. If the viscosity is less than 0.05 Pa · s, the strength of the cured product will be weakened, and if it is 100 Pa · s or more, the fluidity will be lowered.

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

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

Specific examples of such component (A) include organopolysiloxane represented by the following formula.
ViMe ₂ SiO (SiMe ₂ O) _p SiMe ₂ Vi
ViMe ₂ SiO (SiMeViO) _q (SiMe ₂ O) _p SiMe ₂ Vi
Vi ₂ MeSiO (SiMe ₂ O) _p SiMeVi ₂
Vi ₃ SiO (SiMe ₂ O) _p SiVi ₃
Vi ₂ MeSiO (SiMeViO) _q ( _SiMe2O ) _p SiMeVi ₂
Vi ₃ SiO (SiMeViO) _q ( _SiMe2O ) _p SiVi ₃
Me ₃ SiO (SiMeViO) _r ( _SiMe2O ) _p SiMe ₃
(In the formula, p, q, and r are integers of p ≧ 0, q ≧ 0, and r ≧ 2, and are integers that satisfy the viscosity range of the component (A).)

Specific examples of the linear organopolysiloxane of the component (A) include those represented by the following formulas.
ViMe ₂ SiO (SiMe ₂ O) ₂₀₀ SiMe ₂ Vi
ViMe ₂ SiO (SiMe ₂ O) ₄₅₀ SiMe ₂ Vi
The component (A) may be used alone or in combination of two or more.

[(B) component]
The component (B) is a component for imparting strength to the cured product obtained by curing the present composition, and is a three-dimensional network-like organopolysiloxane resin represented by the following average unit formula (1).
(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ¹ SiO _3/2 ) _e (R ² SiO) _3/2 ) _f (SiO ₂ ) _g (1)
(In the formula, R ¹ independently represents an alkenyl group, R ² independently represents a monovalent hydrocarbon group without an addition-reactive carbon-carbon double bond, and at least 80 mol% of all R ² is a methyl group. 1> a ≧ 0, 1> b ≧ 0, 1> c ≧ 0, 1> d ≧ 0, 1> e ≧ 0, 1> f ≧ 0 and 1> g ≧ 0, and b + c + e> 0, It is a number that satisfies e + f + g> 0 and a + b + c + d + e + f + g = 1.)

Further, (B) is waxy or solid at 23 ° C., and “waxic” indicates almost self-fluidity at 23 ° C. of 10,000 Pa · s or more, particularly 100,000 Pa · s or more. It means that it is not gum-like (raw rubber-like).
The alkenyl group represented by ^R1 in the above average composition formula (1) is the same as that exemplified as the alkenyl group in the component (A), but is a vinyl group in terms of availability and price. Is preferable.

The monovalent hydrocarbon group represented by ^R2 and which does not contain an addition-reactive carbon-carbon double bond is the same as that exemplified as the hydrocarbon group bonded to a silicon atom other than the alkenyl group in the component (A). However, it is preferable that at least 80 mol% of the total R ² is a methyl group and 95 to 100 mol% is a methyl group.
a is 0 to 0.65, b is 0 to 0.65, c is 0 to 0.5, d is 0 to 0.5, e is 0 to 0.8, f is 0 to 0.8, and g is. The number is preferably 0 to 0.6. Further, b + c + e is preferably a number of 0.01 to 0.30, particularly 0.05 to 0.20, and e + f + g is a number of 0.1 to 0.8, particularly 0.2 to 0.6. Is preferable.

The organopolysiloxane resin of the component (B) is preferably represented by the following formula, for example.
(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (SiO ₂ ) _g
(R ¹ R ² ₂ SiO _1/2 ) _b (SiO ₂ ) _g
(R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ² SiO _3/2 ) _f
(R ¹ R ² ₂ SiO _1/2 ) _b (R ² ₂ SiO) _d (R ¹ SiO _3/2 ) _e
(R ¹ R ² ₂ SiO _1/2 ) _b (R ² ₂ SiO) _d (R ² SiO _3/2 ) _f
(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ² ₂ SiO) _d (R ² SiO _3/2 ) _f
(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ² SiO _3/2 ) _f
(In the formula, R ¹ , R ² , a, b, c, d, e, f and g are as defined in the above average unit formula (1).)

Specific examples of the component (B) include those represented by the following average unit formula.
(Me ₃ SiO _1/2 ) _0.4 (Vimeo ₂ SiO _1/2 ) _0.1 (SiO ₂ ) _0.5 ,
(ViMeSiO) _0.2 (Me2SiO) _0.35 ( _{MeSiO 3/2 ) 0.45} ,
(ViMe ₂ SiO _1/2 ) _0.2 (Me ₂ SiO) _0.25 (MeSiO _3/2 ) _0.55
The component (B) may be used alone or in combination of two or more.

The blending amount of the component (B) is preferably such that the component (B) is more than 0 parts by mass and less than 80 parts by mass with respect to 100 parts by mass in total of the component (A) and the component (B). Since the hardness of the cured product increases as the blending amount of the component (B) increases, it is possible to adjust the hardness by changing the blending amount of the component (B) according to the design of the LED or the like. More specifically, for example, when stress relaxation is required for a cured product, the component (B) is more than 0 parts by mass and less than 50 parts by mass with respect to 100 parts by mass of the total of the component (A) and the component (B). It is preferable that the amount is as high as possible. On the other hand, for example, when high hardness is required for the cured product, the amount of the component (B) should be 50 parts by mass or more and less than 80 parts by mass with respect to 100 parts by mass of the total of the component (A) and the component (B). Is preferable.

[(C) component]
The component (C) is an organohydrogenpolysiloxane having a hydrogen atom (that is, a SiH group) bonded to at least two silicon atoms per molecule and having no addition-reactive carbon-carbon double bond. , Hydrosilylation reaction with component (A) and component (B), and acts as a cross-linking agent.
The organohydrogenpolysiloxane as a component (C) has an average of at least 2 SiH groups, preferably 3 to 300, and more preferably 4 to 150 SiH groups in one molecule.

The bonding position of the silicon atom-bonded hydrogen atom in the organohydrogenpolysiloxane molecule of the component (C) may be the terminal of the molecular chain, the non-terminal of the molecular chain, or both of them.

The content of the silicon atom-bonded hydrogen atom in the component (C) is preferably 0.01 to 50 mmol, more preferably 0.1 to 20 mmol in 1 g of the component (C).

In this organohydrogenpolysiloxane molecule, the silicon atom-bonded hydrocarbon group other than the silicon atom-bonded hydrogen atom is not particularly limited, but for example, the unsubstituted or substituted carbon atom number is usually 1 to 10, preferably 1. Examples thereof include monovalent alkyl groups 1 to 6. Specific examples thereof include the same components as those exemplified as the silicon atom-bonded hydrocarbon group other than the silicon atom-bonded alkenyl group in the component (A).

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

The viscosity of the component (C) at 25 ° C. is preferably 0.1 to 5,000 mPa · s, more preferably 0, because the workability of the composition, the optical properties of the cured product, and the mechanical properties are more excellent. A range of liquid at 23 ° C., which satisfies the range of 5. to 1,000 mPa · s, particularly preferably 2 to 500 mPa · s, is desirable. When satisfying such a viscosity, the number of silicon atoms (or degree of polymerization) in one molecule of organohydrogenpolysiloxane is usually 2 to 1,000, preferably 3 to 300, and more preferably 4 to 150. Is.

Specific examples of the organohydrogenpolysiloxane of the component (C) include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, and methylhydrogencyclopolysiloxane. Dimethylsiloxane / methylhydrogensiloxane cyclic copolymer, Tris (dimethylhydrogensiloxy) methylsilane, Tris (dimethylhydrogensiloxy) phenylsilane, trimethylsiloxy group-blocked methylhydrogenpolysiloxane at both ends of the molecular chain, trimethyl at both ends of the molecular chain Syloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, molecular chain double-ended trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane / methylphenylsiloxane copolymer, molecular chain double-ended dimethylhydrogensiloxy group-blocked dimethylpolysiloxane , Molecular chain double-ended dimethylhydrogensiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, Molecular chain double-ended dimethylhydrogensiloxy group-blocked dimethylsiloxane / methylphenylsiloxane copolymer, Molecular chain double-ended dimethylhydrogensiloxy Base-sealed methylphenylpolysiloxane, formula: (CH ₃ ) ₂ siloxane unit represented by HSiO _1/2 and formula: (CH ₃ ) ₃ siloxane unit represented by SiO ₂ and formula: siloxane represented by SiO ₂ A copolymer consisting of a unit, a copolymer consisting of a siloxane unit represented by the formula: (CH ₃ ) ₂ HSiO _1/2 and a siloxane unit represented by the formula: SiO ₂ , two of these organopolysiloxanes. Examples thereof include a mixture composed of seeds or more.

The organohydrogenpolysiloxane of the component (C) is preferably represented by the following formula, for example.
Me ₃ SiO (MeHSiO) _i SiMe ₃
Me ₃ SiO (MeHSiO) _i (Me ₂ SiO) _j SiMe ₃
(In the formula, i and j are integers of 2 to 100, preferably 2 to 50.)

Specific examples of the component (C) include organohydrogenpolysiloxane represented by the following formula.
Me ₃ SiO (MeHSiO) ₃₈ SiMe ₃
The organohydrogenpolysiloxane of the component (C) may be used alone or in combination of two or more.

The blending amount of the component (C) is a hydrogen atom bonded to a silicon atom with respect to 1 mol of the alkenyl group in the components (A) and (B) from the viewpoint of the strength, optical properties, and mechanical properties of the cured product. The amount is preferably 0.4 to 4.0 mol, more preferably 0.6 to 3.0 mol.

[(D) component]
The platinum group metal-based hydrosilylation catalyst of the component (D) is particularly any one that promotes the hydrosilylation reaction between the alkenyl group in the components (A) and (B) and the SiH group in the component (C). Specific examples thereof include, but are not limited to, platinum group metals such as platinum, palladium and rhodium; platinum chloride acid, alcohol-modified platinum chloride acid, olefins and vinylsiloxane or acetylene compounds and the like. Platinum-based compounds; platinum-based metal compounds such as tetrakis (triphenylphosphine) palladium and chlorotris (triphenylphosphine) rhodium can be mentioned, but are preferably platinum-based compounds, and particularly preferably a combination of platinum chloride acid and vinylsiloxane. It is a position compound.
The component (D) may be used alone or in combination of two or more.

The blending amount of the component (D) may be an effective amount as a hydrosilylation catalyst, but is 1 in terms of the mass of the platinum group metal with respect to the total mass of the components (A), (B) and (C). It is preferably in the range of about 500 ppm, more preferably in the range of 1 to 100 ppm, and particularly preferably in the range of 1 to 10 ppm. When this range is satisfied, the reaction rate of the addition reaction becomes appropriate, and a cured product having high strength can be obtained.

（式中、Ｒ^４は同種又は異種の一価の炭化水素基、ｎは１～１００の正数、ｍは２～２０の正数である） [(E) component]
The component (E) acts as a component that imparts durability in a high temperature environment to the cured product obtained from the addition-curable silicone composition of the present invention. The component (E) is a reaction product of the following (i) and (ii).
(I) Carboxylate of cerium represented by the following formula (2),
(R ³ CO ₂ ) ₃ Ce (2)
(In the formula, R ³ is a monovalent hydrocarbon group of the same kind or a different kind)
(Ii) A siloxane compound having a carboxylic acid represented by the following formula (3)

(In the formula, ^R4 is a monovalent hydrocarbon group of the same kind or a different kind, n is a positive number of 1 to 100, and m is a positive number of 2 to 20).

The component (E) can be prepared by mixing the components (i) and (ii) and heating them. That is, a compound is produced in which a part or all of the ligand of the cerium atom of the component (i) is replaced with the component (ii).
(I) The component R ³ is a homovalent or heterologous monovalent hydrocarbon group, for example, an unsubstituted or substituted monovalent alkyl group having a carbon atom number of usually 1 to 12, preferably 1 to 10. .. Examples of the unsubstituted or substituted monovalent alkyl group include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and a heptyl group, and a methyl group is preferable.

The component (ii) is a compound designed to react with the component (i) and the reaction product thereof is easily dissolved in silicone, and is composed of a siloxane moiety, an alkylene moiety, and a carboxylic acid moiety.
^R4 in the component (ii) is a monovalent hydrocarbon group of the same kind or a different kind, and the same kind as those exemplified as the hydrocarbon group bonded to a silicon atom other than the alkenyl group in the component (A) can be mentioned. Be done.
(Ii) n in the component is a positive number of 1 to 100, preferably a positive number of 2 to 50, and more preferably a positive number of 5 to 30. If n is too large, the proportion of the component (E) in the composition becomes large, which causes deterioration of the physical properties of the cured product, and in the absence of the siloxane chain, it does not dissolve in the composition.

(Ii) m in the component is a positive number of 2 to 20, preferably 3 to 12.
The amount of the component (ii) with respect to the component (i) is preferably 1 to 10 times, and preferably 3 to 5 times, the mass in terms of solubility in the composition and physical properties of the obtained cured product. More preferred.
The reaction between the component (i) and the component (ii) is preferably carried out at 60 to 200 ° C, more preferably 80 to 150 ° C.
In the reaction, it is preferable to reduce the pressure to 10 kPa or less in order to efficiently proceed with the ligand exchange.
The component (E) may be used alone or in combination of two or more.

The blending amount of the component (E) is such that the content of the cerium atom is 10 to 500 ppm, preferably 20 to 100 ppm, and more preferably 30 to 60 ppm with respect to the entire composition. If the content of the cerium atom is less than 10 ppm with respect to the entire composition, the heat resistance of the obtained cured product is insufficient, and if it exceeds 500 ppm, the physical properties of the cured product may deteriorate.

<Other ingredients>
In addition, components such as an organic peroxide, an antioxidant, an adhesion improver and a reaction inhibitor may be added to the addition-curable silicone composition of the present invention, depending on the intended purpose.

Examples of the organic peroxide include benzoyl peroxide, t-butyl peroxide, o-methylbenzoyl peroxide, p-methylbenzoyl peroxide, dicumyl peroxide, and 1,1-bis (t-butyl peroxide). -3,3,3-trimethylcyclohexane, di (4-methylbenzoylperoxy) hexamethylene biscarbonate and the like can be mentioned.

The blending amount of the organic peroxide is preferably 0.01 to 5 parts by mass, and particularly preferably 0.05 to 3 parts by mass with respect to 100 parts by mass of the total of the components (A) to (E). .. Within such a range, further improvement in resin strength can be achieved. These can be used alone or in combination of two or more.

Examples of the antioxidant include hindered amines and hindered phenolic compounds, and the amount thereof is preferably 500 to 3,000 ppm based on the total mass of the above-mentioned components (A) to (E).

The adhesiveness improving agent is an organosilicon compound such as silane or siloxane containing a functional group that imparts adhesiveness, or a non-silicone type, from the viewpoint of imparting self-adhesiveness to the composition of the present invention which is an addition reaction curing type. Organic compounds and the like are used.
Specific examples of the functional group that imparts adhesiveness include an alkenyl group such as a vinyl group and an allyl group bonded to a silicon atom or a hydrogen atom; an epoxy group bonded to a silicon atom via a carbon atom (for example, γ-glycid). Xypropyl group, β- (3,4-epoxycyclohexyl) ethyl group, etc.), acryloxy group (eg, γ-acryloxypropyl group, etc.), or methacryoxy group (eg, γ-methacryloxypropyl group, etc.); alkoxysilyl An alkoxysilyl group such as a trimethoxysilyl group, a triethoxysilyl group, or a methyldimethoxysilyl group bonded to a silicon atom via an alkylene group which may contain one or two groups (for example, an ester structure, a urethane structure, or an ether structure). Basics, etc.).

Examples of the organic silicon compound containing a functional group that imparts adhesiveness include a silane coupling agent, a siloxane having an alkoxysilyl group and an organic functional group, and a compound in which an alkoxysilyl group is introduced into an organic compound having a reactive organic group. Is exemplified.

Examples of the non-silicone organic compound include an organic acid allyl ester, an epoxy group ring opening catalyst, an organic titanium compound, an organic zirconium compound, and an organic aluminum compound.

Examples of the reaction inhibitor include phosphorus-containing compounds such as triphenylphosphine; nitrogen-containing compounds such as tributylamine, tetramethylethylenediamine and benzotriazole; sulfur-containing compounds; acetylene-based compounds; hydroperoxy compounds; maleic acid derivatives; 1-ethynyl. Cyclohexanol, 3,5-dimethyl-1-hexin-3-ol, ethynylmethyldecylcarbinol, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, etc. Examples of known compounds have a curing inhibitory effect on the hydrosilylation catalyst of the component (D).

Since the degree of the curing inhibitory effect of the reaction inhibitor varies depending on the chemical structure of the reaction inhibitor, it is desirable to adjust the blending amount of the reaction inhibitor to the optimum amount for each reaction inhibitor to be used. Preferably, it is 0.001 to 5 parts by mass with respect to a total of 30 parts by mass of the component (A), the component (B), and the component (C). When the compounding amount is 0.001 part by mass or more, long-term storage stability of the composition at room temperature can be sufficiently obtained. When the compounding amount is 5 parts by mass or less, there is no possibility that the curing of the composition is hindered.

Further, in the addition-curable silicone composition of the present invention, in order to improve the reinforcing property, for example, inorganic fillers such as fine powder silica, crystalline silica, hollow filler, silsesquioxane and the like, and fillers thereof. A filler or the like which has been surface-hydrophobicized with an organic silicon compound such as an organoalkoxysilane compound, an organochlorosilane compound, an organosilazane compound, and a low molecular weight siloxane compound; a silicone rubber powder, a silicone resin powder, or the like may be blended.

The fine powder silica preferably has a specific surface area (BET method) of 50 m ² / g or more, more preferably 50 to 400 m ² / g, and particularly preferably 100 to 300 m ² / g. When the specific surface area is 50 m ² / g or more, sufficient reinforcing property can be imparted to the cured product.

As such fine powder silica, known ones conventionally used as a reinforcing filler for silicone rubber can be used, and for example, fumigant silica (dry silica), precipitated silica (wet silica) and the like can be used. Can be mentioned. Fine powder silica may be used as it is, but in order to impart good fluidity to the composition, methylchlorosilanes such as trimethylchlorosilane, dimethyldichlorosilane and methyltrichlorosilane, dimethylpolysiloxane, hexamethyldisilazane and divinyl It is preferable to use one treated with an organosilicon compound such as hexaorganodisilazane such as tetramethyldisilazane and dimethyltetravinyldisirazane. Such reinforcing silica may be used alone or in combination of two or more.

The addition-curable silicone composition of the present invention can be prepared by mixing the components (A) to (E) and, if necessary, other components. For example, the components (A), (B) and After individually preparing the part composed of the component (D) and the part composed of the component (C) and other components, the two parts can be mixed and used. Further, a part consisting of the component (A), the component (B) and the component (C), and other components as needed, and the component (D) may be mixed.
Since the component (B) is waxy or solid at 23 ° C., a solution obtained by dissolving the component (B) in a solvent is mixed with the component (A) and distilled under reduced pressure in order to dissolve the component (B) in another component. The solvent may be removed from the above step to prepare a mixture of the component (A) and the component (B), and then the mixture may be mixed with other components.

[Silicone cured product]
The addition-curable silicone composition of the present invention can be cured by a known curing method under known curing conditions. Specifically, the composition can be cured by heating at 80 to 200 ° C., preferably 100 to 160 ° C., usually. The heating time may be about 0.5 minutes to 5 hours, particularly about 1 minute to 3 hours, but when accuracy such as for LED encapsulation is required, it is preferable to lengthen the curing time.

The silicone cured product obtained by curing the addition-curable silicone composition of the present invention has excellent transparency, little change in hardness and mass loss under high temperature conditions, and excellent light transmittance and heat resistance. .. For example, the addition-curable silicone composition of the present invention may have a transmittance of light having a wavelength of 400 nm at an optical path length of 2 mm of 85% or more. Further, the addition-curable silicone composition of the present invention may have a mass loss rate of 10% or less after storage at 270 ° C. for 100 hours. Therefore, the addition-curable silicone composition of the present invention can be used as a coating material or encapsulation material for semiconductor devices, particularly semiconductor devices for optical applications, and a protective coating material for electricity and electronics.

[Optical semiconductor device]
Further, the present invention provides an optical semiconductor device sealed with the above-mentioned cured silicone product.
As described above, the cured silicone product of the present invention has excellent transparency, little change in hardness and mass loss under high temperature conditions, and excellent light transmittance and heat resistance. Therefore, the opto-semiconductor device sealed with such a cured silicone material has high reliability.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the following, the viscosity is a value at 25 ° C. measured using a rotational viscometer, and the weight average molecular weight is a standard polystyrene-equivalent value in gel permeation chromatography (GPC). The meaning of the abbreviations for each siloxane unit is as follows.

M: (CH ₃ ) ₃ HSiO _1/2
M ^Vi : (CH ₂ = CH) (CH ₃ ) ₂ SiO _1/2
^DH : (CH ₃ ) HSiO _2/2
D: (CH ₃ ) ₂ SiO _2/2
Q: SiO _4/2

<Synthesis of siloxane compound with carboxylic acid>
[Synthesis Example 1]
In a 1 L flask equipped with a reflux tube, 185 g (1.00 mol) of 10-undecylenic acid and 150 g of toluene were charged and heated to 80 ° C. To this, 100 g (0.620 mol) of hexamethyldisilazane was added dropwise, and after the addition was completed, the mixture was further heated at 80 ° C. for 3 hours. The volatile components were removed by heating to 100 ° C. under reduced pressure, and CH ₂ = CH (CH ₂ ) ₈ CO ₂ SiMe ₃ (silylated b) was obtained through vacuum distillation (242 g, yield 94.0%). ..
In a 1 L flask equipped with a reflux tube, 108 g (421 mmol) of the silylated product b and 30 g (38 mmol) of the siloxane compound c represented by the following average formula (4) were charged and heated to 85 ° C. 0.04 g of a 1-butanol solution of 2% chloroplatinic acid was added dropwise thereto. An additional 270 g (345 mmol) of the siloxane compound c was added dropwise, and then the mixture was heated at 100 ° C. for 3 hours. After cooling to room temperature, 135 g (4.21 mol) of methanol was added, and the mixture was stirred at room temperature for 14 hours. The pressure was reduced, the mixture was heated to 160 ° C. to remove volatile components, allowed to cool to room temperature, and then treated with activated carbon to obtain 364 g (yield 98%) of the siloxane compound a represented by the following average formula (5).

[Synthesis Example 2]
In a 500 mL flask equipped with a reflux tube, 23.4 g (91.2 mmol) of the silylated product b and 200.0 g (82.8 mmol) of the siloxane compound e represented by the following average formula (6) were charged, and the temperature was 85 ° C. Heated to. 0.02 g of a 1-butanol solution of 2% chloroplatinic acid was added dropwise thereto, and then the mixture was heated at 100 ° C. for 3 hours. After cooling to room temperature, 58.4 g (1.82 mol) of methanol and 83.8 g (1.82 mol) of ethanol were added, and the mixture was stirred at room temperature for 14 hours. Reduced pressure, heated to 160 ° C. to remove volatile components, allowed to cool to room temperature, and then treated with activated carbon to obtain 204.8 g (yield 95%) of the siloxane compound d represented by the following average formula (7). rice field.

<Synthesis of (E) component>
[Synthesis Example 3]
3.35 g (10.0 mmol) of cerium acetate / monohydrate and 48.4 g (50.0 mmol) of the siloxane compound a obtained in Synthesis Example 1 were charged in a 100 mL flask, and the temperature was 100 ° C. under a 0.8 kPa environment. The mixture was stirred for 3 hours to obtain 49.3 g of the reaction product (E-1).

[Synthesis Example 4]
3.35 g (10.0 mmol) of cerium acetate / monohydrate and 130.0 g (50.0 mmol) of the siloxane compound d obtained in Synthesis Example 2 were charged in a 300 mL flask, and the temperature was 100 ° C. under a 0.8 kPa environment. The mixture was stirred for 3 hours to obtain 130.0 g of the reaction product (E-2).

[Examples 1 to 4, Comparative Examples 1 to 4]
The following components were mixed in the blending amounts shown in Table 1 to prepare an addition-curable silicone composition. The numerical values of each component in Table 1 represent parts by mass. In each Example and Comparative Example, a solution in which the component (B) was dissolved in xylene was mixed with the component (A), and xylene was removed by distillation under reduced pressure to obtain the components (A) and (B). After preparing the mixture of, it was mixed with other components.

(A) Ingredient:
(A-1) Organopolysiloxane having a viscosity of 5.0 Pa · s represented by the average unit formula M ^Vi ₂ D ₄₅₀ (0.06 mmol / g).

(B) Ingredient:
(B-1) Average composition formula M _0.40 M ^Vi _0.07 Q _0.53 , weight average molecular weight 5,300, vinyl group content 1.0 mmol / g solid at 23 ° C. Organopolysiloxane resin

(C) Ingredient:
(C-1) Average molecular formula: ^{Organohydrogenpolysiloxane} represented by _{M2DH 38} , SiH group content: 15.5 mmol / g, viscosity 20 mPa · s

(D) Ingredient:
(D-1) Toluene solution of platinum complex having 1,3-divinyltetramethyldisiloxane derived from platinum chloride acid as a ligand (containing 1% by mass of platinum)

(E) Ingredient:
(E-1) Cerium compound prepared in Synthesis Example 3 (E-2) Cerium compound prepared in Synthesis Example 4

Comparative component:
(E-3) The siloxane compound d prepared in Synthesis Example 2 above.
(E-4) Cerium acetate monohydrate (E-5) Cerium 2-ethylhexanoate (III) 49% 2-ethylhexanoic acid solution

(F) Component: Addition reaction control agent (F-1) 1-ethynylcyclohexanol

The addition-curable silicone compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were evaluated as follows, and the results are shown in Table 2.
[400 nm light transmittance]
For the cured product obtained by pouring the composition into a mold to a thickness of 2 mm and heating and curing at 150 ° C. for 2 hours, immediately after producing the cured product and after storing the cured product in an environment of 270 ° C. for 100 hours, 25 ° C. The light transmittance of straight light having a wavelength of 400 nm was measured using a spectrophotometer U-3900 (manufactured by Hitachi High-Tech Science Co., Ltd.).

[hardness]
For the cured product obtained by heating and curing the composition at 150 ° C. for 2 hours, the Type A hardness of the cured product at 25 ° C. was measured immediately after preparation of the cured product and after the cured product was stored in an environment of 270 ° C. and 100 hours. did.

[Mass% after heat resistance test]
When the initial mass of the cured product used for measuring the above light transmittance was 100, the mass after storage in an environment of 270 ° C. for 100 hours was measured.

As shown in Table 2, it can be seen that the cured products obtained from the addition-curable silicone compositions of Examples 1 to 4 have excellent light transmittance at a wavelength of 400 nm, and the hardness change and mass loss under high temperature conditions are small.

On the other hand, Comparative Example 1 in which the component (E) of the present invention was not used, Comparative Example 2 in which only a siloxane compound having a carboxylic acid was added in place of the component (E) of the present invention, and only the carboxylic acid salt of cerium. In Comparative Example 3 to which the above was added, sufficient heat resistance was not exhibited, and in Comparative Example 4 using a cerium compound coordinated with a carboxylic acid having no siloxane chain, the light transmittance at a wavelength of 400 nm was inferior.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and the present invention can be anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same function and effect. Is included in the technical scope of.

Claims (5)

(A) A linear organopolysiloxane having at least two alkenyl groups bonded to a silicon atom in one molecule and having a viscosity at 25 ° C. of 0.05 to 100 Pa · s.
(B) A three-dimensional network organopolysiloxane resin represented by the following average unit formula (1) and which is waxy or solid at 23 ° C.
(R ² ₃ SiO _1/2 ) _a (R ¹ R ² ₂ SiO _1/2 ) _b (R ¹ R ² SiO) _c (R ² ₂ SiO) _d (R ¹ SiO _3/2 ) _e (R ² SiO) _3/2 ) _f (SiO ₂ ) _g (1)
(In the formula, R ¹ independently represents an alkenyl group, R ² independently represents a monovalent hydrocarbon group without an addition-reactive carbon-carbon double bond, and at least 80 mol% of all R ² is a methyl group. 1> a ≧ 0, 1> b ≧ 0, 1> c ≧ 0, 1> d ≧ 0, 1> e ≧ 0, 1> f ≧ 0 and 1> g ≧ 0, and b + c + e> 0, It is a number that satisfies e + f + g> 0 and a + b + c + d + e + f + g = 1.)
(C) Organohydrogenpolysiloxane, which has a hydrogen atom bonded to at least two silicon atoms per molecule and does not have an addition-reactive carbon-carbon double bond.
(D) Hydrosilylation catalyst containing platinum group metal, and (E) Reaction product of the following (i) and (ii): Amount in which the content of cerium atom is 10 to 500 ppm with respect to the entire composition (i). ) Cerium carboxylate represented by the following formula (2),
(R ³ CO ₂ ) ₃ Ce (2)
(In the formula, R ³ is a monovalent hydrocarbon group of the same kind or a different kind)
(Ii) A siloxane compound having a carboxylic acid represented by the following formula (3)

(In the formula, ^R4 is a monovalent hydrocarbon group of the same kind or a different kind, n is a positive number of 1 to 100, and m is a positive number of 2 to 20).
Additive curable silicone composition containing. A silicone cured product, which is a cured product of the addition-curable silicone composition according to claim 1. The cured silicone product according to claim 2, wherein the transmittance of light having a wavelength of 400 nm at an optical path length of 2 mm is 85% or more. The cured silicone product according to claim 2 or 3, wherein the mass loss rate after storage at 270 ° C. for 100 hours is within 10%. An optical semiconductor device characterized by being sealed with the cured silicone product according to any one of claims 2 to 4.