JP7103974B2 - Additive-curable silicone composition, cured silicone for light-reflecting material, light-reflecting material and optical semiconductor device - Google Patents

Description

The present invention relates to an addition-curable silicone composition, a cured silicone for a light-reflecting material, a light-reflecting material, and an optical semiconductor device.

In recent years, optical semiconductor elements such as light emitting diodes (hereinafter referred to as "LEDs") are widely used as indicators and light sources because they emit light with high efficiency and are excellent in drive characteristics and lighting repetition characteristics. In particular, white LEDs are widely used as backlights for display devices and flashes for cameras, and are also used for lighting applications. Such a light emitting device is equipped with a material that reflects the emitted light in order to improve the efficiency of extracting light in the irradiation direction.

The lead frame used for an LED often has a function of passing an electric current and reflecting light. Specifically, silver plating having good light reflectance is preferably used.
However, silver plating has a problem that when it comes into contact with a gas from the outside, it causes oxidation and sulfurization, and the reflectance tends to decrease. Gold plating or aluminum may be used to prevent corrosion due to external gas, but both have the problem of low visible light reflectance.

Further, a light-reflecting resin, ceramic, or the like is used as the insulating member, and the portion thereof is also required to have a function of reflecting light, but it is not necessarily limited to a material having a high light reflectance.
In order to solve these problems, a method of thinly coating a resin having high light reflectance on a lead frame or an insulating member can be considered (hereinafter, referred to as "white coating material").

Patent Documents 1 and 2 propose light-reflecting materials containing an epoxy resin, a metal oxide, or the like as constituents. However, these materials are inferior in high temperature durability and light durability as compared with a cured product composed of a silicone resin and a metal oxide.
Patent Documents 3 and 4 propose light-reflecting materials containing silicone resin, metal oxide, and the like as constituents. However, while these materials have excellent durability, the composition itself does not have the fluidity to wet and spread, so that they are not suitable as white coating materials.

Japanese Unexamined Patent Publication No. 2008-106226 Japanese Patent No. 4694371 Japanese Unexamined Patent Publication No. 2012-23305 Japanese Unexamined Patent Publication No. 2013-22107

The present invention has been made in view of the above circumstances, and provides an addition-curing silicone composition having high fluidity and providing a cured product having excellent light reflection performance even in a thin film. With the goal.

（式中、Ｒ^３は独立にアルコキシ基であり、Ｒ^４はアルコキシ基またはアルキル基であり、ｎは０または１であり、ｍは１～１０の整数である。）
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, the present invention
(A) A linear organopolysiloxane having at least two alkenyl groups bonded to a silicon atom and having a viscosity at 25 ° C. of 0.05 to 100 Pa · s: 50 to 97 parts by mass,
(B) A three-dimensional network-like organopolysiloxane resin represented by the following average unit formula (1) and being waxy or solid at 23 ° C.: 3 to 50 parts by mass (however, the components (A) and (B) The total is 100 parts by mass.),
(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 having a hydrogen atom bonded to at least two silicon atoms per molecule and having no addition-reactive carbon-carbon double bond: among the components (A) and (B). Hydrosilylation catalyst containing (D) platinum group metal in an amount of 0.4 to 4.0 mol of hydrogen atom bonded to a silicon atom with respect to 1 mol of alkenyl group: component (A), component (B) and (C) ) An amount that is 0.1 to 1000 ppm in terms of the mass of the platinum group metal with respect to the total mass of the components.
(E) Titanium oxide powder treated with siloxane on the surface: 20 to 200 parts by mass, and (F) Compound represented by the following formula (2): 0.1 to 10 parts by mass

(In the formula, R ³ is an independent alkoxy group, R ⁴ is an alkoxy group or an alkyl group, n is 0 or 1, and m is an integer of 1 to 10.)
To provide an addition-curable silicone composition containing the above.

This addition-curable silicone composition has high fluidity at room temperature and further provides a cured product having excellent light reflection performance in a thin film.

The present invention also provides a cured silicone for a light reflecting material, which is a cured product of the addition-curable silicone composition.
This cured product is excellent in light reflection performance in a thin film.

The cured product preferably has a thickness of 0.3 mm or less and a reflectance of light having a wavelength of 430 to 800 nm of 90% or more.
The cured product having a reflectance of a predetermined value or higher is superior in light reflection performance in a thin film.

The present invention provides a light-reflecting material made of the above-mentioned cured silicone material for a light-reflecting material.
This light-reflecting material has excellent light-reflecting performance even if it is thin.

Furthermore, the present invention provides an optical semiconductor device having the above-mentioned light reflecting material.
This optical semiconductor device can maintain high light extraction efficiency for a long period of time.

Since the addition-curable silicone composition of the present invention has high fluidity at room temperature, it is excellent in workability and handleability. be able to. Further, the silicone cured product obtained by thermosetting the composition is excellent in light reflection performance even in a thin film. Therefore, the cured product is useful as a light-reflecting material for optical semiconductors, particularly as a light-reflecting coating material.

It is sectional drawing which shows typically an example of the optical semiconductor device which uses the silicone cured material for a light reflector of this invention.

As described above, there has been a demand for the development of an addition-curing silicone composition which is an addition-curing silicone composition having high fluidity and which gives a cured product having excellent light reflection performance even in a thin film.

As a result of diligent research, the present inventors can achieve the above-mentioned problems if the addition-curable silicone composition containing the following components (A) to (F) is suitable as a light-reflecting material. We found that and completed the present invention.

（式中、Ｒ^３は独立にアルコキシ基であり、Ｒ^４はアルコキシ基またはアルキル基であり、ｎは０または１であり、ｍは１～１０の整数である。）
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 and having a viscosity at 25 ° C. of 0.05 to 100 Pa · s: 50 to 97 parts by mass,
(B) A three-dimensional network-like organopolysiloxane resin represented by the following average unit formula (1) and being waxy or solid at 23 ° C.: 3 to 50 parts by mass (however, the components (A) and (B) The total is 100 parts by mass.),
(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 having a hydrogen atom bonded to at least two silicon atoms per molecule and having no addition-reactive carbon-carbon double bond: among the components (A) and (B). Hydrosilylation catalyst containing (D) platinum group metal in an amount of 0.4 to 4.0 mol of hydrogen atom bonded to a silicon atom with respect to 1 mol of alkenyl group: component (A), component (B) and (C) ) An amount that is 0.1 to 1000 ppm in terms of the mass of the platinum group metal with respect to the total mass of the components.
(E) Titanium oxide powder treated with siloxane on the surface: 20 to 200 parts by mass, and (F) Compound represented by the following formula (2): 0.1 to 10 parts by mass

(In the formula, R ³ is an independent alkoxy group, R ⁴ is an alkoxy group or an alkyl group, n is 0 or 1, and m is an integer of 1 to 10.)
It is an addition hardening type 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 rotational viscometer.

<Additional curable silicone composition>
Hereinafter, each component will be described in detail.
[(A) component]
The component (A) is a component that serves as 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 decrease.

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 is insufficient, and if the number is 20 or less, the cured product does 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. , Aryl groups such as trill group, xsilyl group, naphthyl group; Aralkyl groups such as benzyl group and phenethyl group; some or all of hydrogen atoms of 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 ( _SiMe2O ) _{p SiMe2} 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 free of add-reactive carbon-carbon double bonds, 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, the component (B) is waxy or solid at 23 ° C., and “waxic” means that the component (B) has 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 gum-like (raw rubber-like) that is not shown.

In the above average composition formula (1), the alkenyl group represented by R 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 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 (ViMe 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 3 to 50 parts by mass, preferably 3 to 30 parts by mass, and more preferably 5 to 20 parts by mass with respect to 100 parts by mass in total of the component (A) and the component (B). It is a department. If the blending amount of the component (B) is less than 3 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B), it becomes difficult to obtain fluidity. On the other hand, when the compounding amount exceeds 50 parts by mass, the viscosity of the composition increases and the fluidity decreases.

[Component (C)]
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 of the component (C) has an average of at least 2, 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 0.001 to 5 mol, particularly preferably 0.01 to 2 mol, in 100 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 those similar to those exemplified as silicon atom-bonded hydrocarbon groups other than the silicon atom-bonded alkenyl group in the component (A).

The molecular structure of the organohydrogenpolysiloxane of the component (C) is not particularly limited, and examples thereof include a linear, cyclic, branched chain, and three-dimensional network structure (resin), and the linear or cyclic structure is 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, molecular chain double-ended trimethylsiloxy group-blocked methylhydrogenpolysiloxane, molecular chain double-ended trimethyl Syroxy 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-blocking methylphenylpolysiloxane, formula: (CH ₃ ) ₂ siloxane unit represented by HSiO _1/2 and formula: (CH ₃ ) ₃ siloxane unit represented by SiO _1/2 and formula: SiO _4/2 A copolymer composed of a siloxane unit represented by the formula: (CH ₃ ) ₂ A copolymer composed of a siloxane unit represented by HSiO _1/2 and a siloxane unit represented by the formula: SiO _4/2 , these Examples thereof include a mixture consisting of two or more kinds of organopolysiloxanes.

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 an alkenyl group in the components (A) and (B) from the viewpoint of strength, optical properties, and mechanical properties of the cured product. Is an amount of 0.4 to 4.0 mol, preferably 0.6 to 3.0 mol.

[(D) component]
The platinum group metal-based hydrosilylation catalyst of the component (D) is particularly capable of promoting 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-based compounds: Platinum group metal compounds such as tetrakis (triphenylphosphine) palladium and chlorotris (triphenylphosphine) rhodium can be mentioned, but are preferably platinum-based compounds, and particularly preferably the arrangement of chloroplatinic 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, and is 0. It is in the range of 1 to 1000 ppm, preferably in the range of 1 to 500 ppm. When such a range is satisfied, the reaction rate of the addition reaction becomes appropriate, and a cured product having high strength can be obtained.

[(E) component]
The component (E) is a titanium oxide powder whose surface is treated with siloxane, and is a component that imparts light reflection performance to the present composition.

If the surface of the titanium oxide powder is not treated with siloxane, bubbles will be generated when the addition-curable silicone composition is cured by the moisture contained in the powder, and sufficient performance as a light-reflecting material cannot be exhibited. .. In order to prevent foaming, there is a method of heating and depressurizing mixing in silicone, but this step is not preferable because the fluidity is lowered.
The crystal morphology of titanium oxide is classified into anatase, rutile, and brookite, and it is preferable to use the rutile type, which has the most stable thermal transition.

The particle size of the component (E) is not particularly limited, but in general, many of them have an average particle size in the range of 0.1 to 200 μm and are easily handled, and those having an average particle size in the range of 0.1 to 100 μm are more preferable. When the average particle size of the component (E) is in the range of 0.1 to 200 μm, the addition-curable silicone composition of the present invention tends to have good fluidity, and the surface of the obtained cured product is less likely to be roughened. Light reflection performance is effectively improved.
As such a component (E), a commercially available product may be used, and specific examples thereof include Typake PF-691 and Typake CR-63 manufactured by Ishihara Sangyo Co., Ltd.
The component (E) may be used alone or in combination of two or more.

The blending amount of the component (E) is 20 to 200 parts by mass with respect to a total of 100 parts by mass of the components (A) and (B). It is preferably 30 to 150 parts by mass, and more preferably 40 to 100 parts by mass. If the blending amount of the component (E) is less than 20 parts by mass with respect to the total of 100 parts by mass of the components (A) and (B), the cured product has poor light reflection performance, and if it exceeds 200 parts by mass, it flows. It becomes difficult to obtain sex.

[(F) component]
The component (F) is a component for imparting fluidity to the addition-curable silicone composition of the present invention by coexisting with the component (B), and is a compound represented by the following formula (2).

（式中、Ｒ^３は独立にアルコキシ基であり、Ｒ^４はアルコキシ基またはアルキル基であり、ｎは０又は１であり、好ましくは１である。ｍは１～１０の整数であり、好ましくは２～９であり、さらに好ましくは３～８である。）

(In the formula, R ³ is an independently alkoxy group, R ⁴ is an alkoxy group or an alkyl group, n is 0 or 1, preferably 1. m is an integer of 1 to 10, preferably. Is 2 to 9, more preferably 3 to 8).

R ³ in the formula (2) is independently an alkoxy group having, for example, 1 to 6 carbon atoms. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a cyclopentyloxy group, a cyclohexyloxy group and the like, preferably a methoxy group and an ethoxy group, more preferably. Is a methoxy group.

R ⁴ in the formula (2) is an alkoxy group or an alkyl group, and examples of the alkoxy group are the same as those of the alkoxy group exemplified in R ³ . Examples of the alkyl group include those similar to those exemplified in the component (A).

Specific examples of such component (F) include, but are not limited to, those shown below.

（Ｆ）成分は、一種単独で用いても二種以上を併用してもよい。

The component (F) may be used alone or in combination of two or more.

The blending amount of the component (F) is 0.1 to 10 parts by mass with respect to 100 parts by mass of the total of the components (A) and (B), preferably 0.5 to 5. It is 0 parts by mass. If the amount of the component (F) is too small, the fluidity is lowered, and if the amount of the component (F) is too large, the durability of the obtained cured product is lowered.

<Other ingredients>
In addition to the curable silicone composition of the present invention, components such as an organic peroxide, an antioxidant, an adhesive improver and a reaction inhibitor may be added 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-methylbenzoyl peroxide) hexamethylene biscarbonate and the like can be mentioned.

The amount of the organic peroxide added is preferably 0.01 to 5 parts by mass, particularly preferably 0.05 to 3 parts by mass, based on 100 parts by mass of the total of the components (A) to (F). .. 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 of the antioxidant added is preferably 500 to 3,000 ppm based on the total mass of the above-mentioned components (A) to (F).

As the adhesiveness improver, an organosilicon compound such as silane or siloxane containing a functional group that imparts adhesiveness, a non-silicone type, is used 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 metharoxy 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 hardening 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 an 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 blending amount is 5 parts by mass or less, there is no possibility that the curing of the composition is hindered.

Further, in order to improve the reinforcing property, the addition-curable silicone composition of the present invention contains, for example, inorganic fillers such as fine powder silica, crystalline silica, hollow filler, silsesquioxane, and fillers thereof. Is 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 that have been conventionally used as a reinforcing filler for silicone rubber can be used. For example, aerosol silica (dry silica), precipitated silica (wet silica) and the like can be used. Can be mentioned. Fine powdered 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 dimethyltetravinyldisilazane. 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 (F) and, if necessary, other components. For example, the components (A), (B) and After preparing the part containing the component (D) and the part containing the component (C) individually, the two parts can be mixed and used. Further, the part containing the component (A), the component (B) and the component (C) and the part containing 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 off 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.

The addition-curable silicone composition of the present invention is liquid before curing and has high fluidity. The fluidity here means how much it flows on a slanted smooth plate, and is not necessarily correlated with the rotational viscosity, so it is distinguished.

When 0.05 g of the addition-curable silicone composition of the present invention is placed on an aluminum plate having an inclination angle of 45 ° with respect to the horizontal and allowed to stand at 25 ° C. for 1 hour, the length (flowability) is preferably 30 mm or more, preferably 40 mm or more. Is more preferable. When the flowability is 30 mm or more, the composition easily spreads the coated surface and the workability is good. The length here is the maximum straight line distance from one end of the composition to the other.

[Silicone cured product for light reflector]
By curing the addition-curable silicone composition of the present invention, a white silicone cured product for a light-reflecting material can be obtained. Since the addition-curable silicone composition of the present invention has good fluidity, the light-reflecting material can be coated with a thin film by applying it by dispensing, self-leveling, and then curing it. The curing conditions of the addition-curable silicone composition of the present invention are not particularly limited, but are usually 80 to 200 ° C., preferably 100 to 180 ° C. for 1 minute to 24 hours, and 5 minutes to 5 minutes. Time conditions are even more preferred.

Since the addition-curable silicone composition of the present invention is intended to be used as a thin film coating, it is necessary that the reflectance of the thin film of visible light (wavelength: 430 to 800 nm) is good. Specifically, it is preferable that the visible light reflectance is 90% or more (that is, 90 to 100%) when the thickness of the cured product is 0.3 mm or less. More preferably, the visible light reflectance is 95% or more (that is, 95 to 100%). When the reflectance is 90% or more, when a lead frame having a low light reflectance such as gold plating or aluminum is coated, the light extraction efficiency becomes higher and sufficient brightness is easily secured for the optical semiconductor element. can. In this specification, the light reflectance means a numerical value measured by a spectrophotometer device equipped with an integrating sphere.

[Light reflector]
The light-reflecting material made of the silicone cured product for a light-reflecting material of the present invention can be suitably used as a light-reflecting coating material for an optical semiconductor device such as an LED, particularly a lead frame for a white LED.

[Optical semiconductor device]
Furthermore, the present invention provides an optical semiconductor device having the above-mentioned light reflecting material.
As described above, the addition-curable silicone composition of the present invention provides a cured silicone product for a light-reflecting material having excellent light-reflecting performance even in a thin film. Therefore, an optical semiconductor device such as a white LED using the light reflecting material of the present invention can maintain high light extraction efficiency for a long period of time.

An embodiment of the optical semiconductor device of the present invention will be described with reference to FIG. As shown in FIG. 1, by dropping the white coating material 6 onto the lead electrode 2 included in the optical semiconductor device 7, the white coating material 6 is wetted and spread so as to cover the lead electrode 2 and the like, and after curing, light is emitted instead of the lead electrode 2. The light emitted from the element 1 can be reflected to improve the light extraction efficiency. The light emitting element 1 bonded on the lead electrode 2 with the die bond material 3 is connected to the lead electrode 2 by a gold wire 4. Further, a reflector is formed on the peripheral edge of the optical semiconductor device 7 by the light reflecting resin 5.

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.
^MH : (CH ₃ ) ₂ HSiO _1/2
M: (CH ₃ ) ₃ S iO _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

[Examples 1 to 3, Comparative Examples 1 to 6]
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 Examples 1 to 3 and Comparative Examples 1 to 3 to 6, 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 (A). A mixture of the component and the component (B) was prepared and then mixed with other components.

That is, first, using a 5 liter gate mixer (manufactured by Inoue Seisakusho Co., Ltd., trade name: 5 liter planetary mixer), a mixture of the component (A) and the component (B) (component (A) in Comparative Example 2). Only) and component (E) are mixed at 25 ° C. for 1 hour, then component (D) and component (F) are added and mixed at 25 ° C. for 30 minutes, and then component (G) is added and 25 ° C. Finally, the component (C) was added and mixed in an environment of 25 ° C. and reduced pressure (30 mmHg) for 30 minutes to obtain an addition-curable silicone composition.

With respect to Comparative Example 6, a step of dehydrating titanium oxide was added with the same composition as that of Comparative Example 5. That is, first, using a 5 liter gate mixer, the mixture of the component (A) and the component (B) and the component (E) are mixed for 1 hour in an environment of 150 ° C. and reduced pressure (30 mmHg) to dehydrate titanium oxide. After returning to 25 ° C., the components (D) and (F) were added and mixed for 30 minutes, then the component (G) was added and mixed at 25 ° C. for 30 minutes, and finally the component (C) was added. In addition, the mixture was mixed in an environment of 25 ° C. and reduced pressure (30 mmHg) for 30 minutes to obtain an addition-curable silicone composition.

(A) Ingredient:
(A-1) Average molecular formula: Organopolysiloxane having a viscosity of 1.0 Pa · s represented by M ^Vi ₂ D ₂₀₀ (0.013 mol / 100 g).

(B) Ingredient:
(B-1) Average unit 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

Ingredient (C):
(C-1) Average molecular formula: Organohydrogenpolysiloxane having a viscosity of 20 mPa · s represented by M ₂ ^DH ₃₈ (1.55 mol / 100 g).

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

(E) Ingredient:
(E-1) Titanium oxide powder, Taipaque PF-691 manufactured by Ishihara Sangyo Co., Ltd. (siloxane treatment, average particle size 0.21 μm)
(E-2) Titanium oxide powder, Taipaque CR-63 manufactured by Ishihara Sangyo Co., Ltd. (siloxane treatment, average particle size 0.21 μm)
Comparative component:
(E-3) Titanium oxide powder, Taipaque R-820 manufactured by Ishihara Sangyo Co., Ltd. (Al, Si, Zr treatment, average particle size 0.26 μm)
(E-4) Titanium oxide powder, Taipaque CR-60 manufactured by Ishihara Sangyo Co., Ltd. (Al treatment, average particle size 0.21 μm)

(F) Ingredient:
(F-1) Compound represented by the following formula (3)

(F-2) Compound represented by the following formula (4)

Comparative component:
(F-3) Compound represented by the following formula (5)

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

The addition-curable silicone compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 6 were evaluated as follows, and the results are shown in Table 2.
[Flowability of composition]
0.05 g of each composition was weighed on an aluminum plate, and the length of the composition was measured after placing it at an angle of 45 ° with respect to the horizontal for 1 hour in an environment of 25 ° C. The length here is the maximum straight line distance from one end of the composition to the other. When it flows to a length of 30 mm or more, it indicates that the composition has good fluidity.

Further, each composition was poured into a mold and cured in an oven at 150 ° C. for 2 hours to obtain a cured product having a thickness of 0.3 mm. The obtained cured product was evaluated as follows, and the results are shown in Table 2.

[exterior]
The surface of the cured product was observed using a microscope and evaluated according to the following criteria.
Uniform appearance (GOOD), foaming (NG)

[Light reflectance]
The light reflectance of the cured product at wavelengths of 430 nm, 600 nm, and 800 nm was measured at 25 ° C. using a spectrophotometer device U-3310 manufactured by Hitachi, Ltd. equipped with an integrating sphere.

As shown in Table 2, it is shown that the addition-curable silicone compositions of Examples 1 to 3 have high fluidity at 25 ° C., do not foam during curing, and have excellent light reflectance of the cured product. ing. Therefore, the cured product of the addition-curable silicone composition of the present invention is useful as a coating material for a light-reflecting material, particularly a reflector material for an optical semiconductor device.

On the other hand, in Comparative Examples 1 and 3 in which the component (F) of the present invention is not used and Comparative Example 2 in which the component (B) of the present invention is not used, the flowability of the composition is insufficient, and the (E) of the present invention is insufficient. In Comparative Examples 4 and 5 in which titanium oxide powder not subjected to the siloxane treatment on the surface was used instead of the component), bubbles were generated in the cured product. Further, in Comparative Example 6 in which the dehydration step of titanium oxide was added to the same compounding composition as in Comparative Example 5, the flowability of the composition was significantly impaired.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and any object having substantially the same structure as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. Is included in the technical scope of.

1 ... light emitting element, 2 ... lead electrode, 3 ... die bond material,
4 ... Gold wire, 5 ... Light reflective resin, 6 ... White coating material,
7 ... Optical semiconductor device.

Claims (5)

(A) A linear organopolysiloxane having at least two alkenyl groups bonded to a silicon atom and having a viscosity at 25 ° C. of 0.05 to 100 Pa · s: 50 to 97 parts by mass,
(B) A three-dimensional network-like organopolysiloxane resin represented by the following average unit formula (1) and being waxy or solid at 23 ° C.: 3 to 50 parts by mass (however, the components (A) and (B) The total is 100 parts by mass.),
(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 having a hydrogen atom bonded to at least two silicon atoms per molecule and having no addition-reactive carbon-carbon double bond: among the components (A) and (B). Hydrosilylation catalyst containing (D) platinum group metal in an amount of 0.4 to 4.0 mol of hydrogen atom bonded to a silicon atom with respect to 1 mol of alkenyl group: component (A), component (B) and (C) ) An amount that is 0.1 to 1000 ppm in terms of the mass of the platinum group metal with respect to the total mass of the components.
(E) Titanium oxide powder treated with siloxane on the surface: 20 to 200 parts by mass, and (F) Compound represented by the following formula (2): 0.1 to 10 parts by mass

(In the formula, R ³ is an independent alkoxy group, R ⁴ is an alkoxy group or an alkyl group, n is 0 or 1, and m is an integer of 1 to 10.)
An addition-curable silicone composition comprising. A cured silicone product for a light-reflecting material, which is a cured product of the addition-curable silicone composition according to claim 1. The silicone cured product for a light reflecting material according to claim 2, wherein the reflectance of light having a wavelength of 430 to 800 nm at a thickness of 0.3 mm or less is 90% or more. A light-reflecting material comprising the cured silicone material for a light-reflecting material according to claim 2 or 3. An optical semiconductor device comprising the light reflecting material according to claim 4.

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