JP2018002970A - Thermosetting silicone resin composition and optical semiconductor device using the molded body - Google Patents

Abstract

The present invention provides a thermosetting silicone resin composition that provides a cured product that is excellent in fluidity during molding and has excellent toughness, particularly flexibility, after secondary curing, and an optical semiconductor device using the same. (A) Condensation reaction type resinous organopolysiloxane solid at 25 ° C .: 70 to 95 parts by mass, (B) At least one linear diorganopolysiloxane residue is contained in one molecule Organopolysiloxane having a cyclohexyl group or phenyl group: 2 to 30 parts by mass, (C) an acrylic resin-based modifier having an alkoxysilyl group having a weight average molecular weight of 1,000 to 20,000: 2 to 20 mass Parts (however, the sum of the components (A), (B) and (C) is 100 parts by mass) (D) inorganic filler: 300 to 1,200 parts by mass, and (E) organometallic condensation catalyst: 0 The thermosetting silicone resin composition characterized by containing 0.01-5 mass parts. [Selection figure] None

Description

  The present invention relates to a thermosetting silicone resin composition and an optical semiconductor device having a molded body obtained by curing the composition.

  Optical semiconductor elements such as LEDs (Light Emitting Diodes) are used as various indicators and light sources such as street displays, automobile lamps, and residential lighting. Above all, white LEDs are rapidly developing products that are applied in various fields with the keywords of carbon dioxide reduction and energy saving.

  Polyphthalamide resin (PPA) has been widely used as an optical reflector material as one of the materials for semiconductors and electronic devices such as LEDs. The use of thermosetting resins is becoming the center.

  Patent Documents 1 and 2 describe a white thermosetting epoxy resin composition using a triazine derivative epoxy resin, and Patent Document 3 describes a white thermosetting epoxy resin composition using an alicyclic epoxy compound. Yes. The white thermosetting epoxy resin compositions described in these are all made of epoxy resins and acid anhydrides that do not have aromaticity, and are used because they have certain heat resistance and light resistance. However, in the present situation where lighting applications and in-vehicle applications are increasing, those having higher reliability in terms of heat resistance and light resistance have become necessary.

  Patent Documents 4 and 5 describe white thermosetting silicone resin compositions using organopolysiloxane as a material having excellent heat resistance and light resistance. Although these are very excellent materials from the viewpoint of reliability, they have poor toughness due to the chemical characteristics of silicone resins, and have a very large coefficient of thermal expansion from room temperature to high temperature. For this reason, the balance between formability and warpage characteristics is not fully satisfied.

JP 2006-140207 A JP 2008-189827 A JP 2013-100410 A JP 2009-221393 A Japanese Patent Laying-Open No. 2015-229749

  Accordingly, an object of the present invention is to provide a thermosetting silicone resin composition that gives a cured product that is excellent in fluidity at the time of molding and has excellent toughness and particularly flexibility after secondary curing, and an optical semiconductor device using the same. The purpose is to provide.

As a result of intensive studies to solve the above problems, the present inventors have found that the following thermosetting silicone resin composition is a thermosetting silicone resin that can achieve the above object, and completed the present invention. .
That is, this invention provides the following thermosetting silicone resin composition and a semiconductor device using the same.

<1>
A thermosetting silicone resin composition comprising the following components (A), (B), (C), (D) and (E): However, the mass part of each component is a mass part with respect to a total of 100 mass parts of (A), (B), and (C) component.
(A) Condensation reaction type resinous organopolysiloxane solid at 25 ° C .: 70 to 95 parts by mass (B) 1 molecule having a linear diorganopolysiloxane residue represented by the following general formula (2) Organopolysiloxane having at least one cyclohexyl group or phenyl group therein: 2 to 30 parts by mass

Wherein R ² is independently a monovalent hydrocarbon group selected from a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group, a phenyl group, a vinyl group and an allyl group, and m is 5 to 50 Indicates an integer.)
(C) Acrylic resin modifier having an alkoxysilyl group and a weight average molecular weight of 1,000 to 20,000: 2 to 20 parts by mass (D) Inorganic filler: 300 to 1,200 parts by mass (E) Organometallic condensation catalyst: 0.01 to 5 parts by mass

<2>
Furthermore, the thermosetting silicone resin composition as described in <1> which contains 3-300 mass parts of white pigments as (F) component.

<3>
The condensation reaction type resinous organopolysiloxane of the resinous organopolysiloxane solid at room temperature as the component (A) has the following average composition formula (1)
(CH ₃ ) _a Si (OR ¹ ) _b (OH) _c O _{(4-abc) / 2} (1)
(Wherein R ¹ represents the same or different organic group having 1 to 4 carbon atoms, and a, b and c are 0.8 ≦ a ≦ 1.5, 0 ≦ b ≦ 0.3, 0. (A number satisfying 001 ≦ c ≦ 0.5 and 0.801 ≦ a + b + c <2.)
The thermosetting silicone resin composition according to <1> or <2>, which is a resinous organopolysiloxane having a polystyrene-equivalent weight average molecular weight of 1,000 to 20,000.

<4>
The case for optical semiconductor elements formed with the thermosetting silicone resin composition of any one of <1> to <3>.

<5>
An optical semiconductor device comprising the optical semiconductor element case according to <4>.

<6>
<1> to <3> A photocoupler sealed with the thermosetting silicone resin composition according to any one of <3>.

<7>
An optical semiconductor device comprising the photocoupler according to <6>.

  The thermosetting silicone resin composition of the present invention is excellent in fluidity at the time of molding and gives a cured product having excellent toughness, particularly flexibility after secondary curing. Therefore, it is useful as a thermosetting silicone resin composition for optical semiconductor devices.

  Hereinafter, the present invention will be described in more detail.

<(A) Condensation reaction type resinous organopolysiloxane solid at 25 ° C.>
The (A) component organopolysiloxane forms a crosslinked structure together with the (B) component linear organopolysiloxane in the presence of the later-described component (E) organometallic condensation catalyst.

As the organopolysiloxane of component (A), for example, the following average composition formula (1)
(CH ₃ ) _a Si (OR ¹ ) _b (OH) _c O _{(4-abc) / 2} (1)
(In the above formula (1), R ¹ is the same or different organic group having 1 to 4 carbon atoms. A, b and c are 0.8 ≦ a ≦ 1.5, 0 ≦ b ≦ 0. 3, 0.001 ≦ c ≦ 0.5 and 0.801 ≦ a + b + c <2.
Resin-like organo (ie, branched or three-dimensional network structure) having a polystyrene-reduced weight average molecular weight of 1,000 to 20,000 by gel permeation chromatography (GPC) using tetrahydrofuran or the like as a developing solvent Polysiloxane is mentioned.

  In the average composition formula (1), a composition containing an organopolysiloxane having a methyl group content a of less than 0.8 is not preferable because the cured product thereof is too hard, resulting in poor crack resistance. On the other hand, if a exceeds 1.5, the resulting resinous organopolysiloxane is not preferred because it is difficult to solidify. The methyl group content in the component (A) is preferably 0.8 ≦ a ≦ 1.2, more preferably 0.9 ≦ a ≦ 1.1.

  In the above average composition formula (1), when b indicating the content of the alkoxy group exceeds 0.3, the molecular weight of the obtained resinous organopolysiloxane tends to be small, and the crack resistance is often lowered. As for content of the alkoxy group in (A) component, 0.001 <= b <= 0.2 is preferable, More preferably, it is 0.01 <= b <= 0.1.

In the above average composition formula (1), when c indicating the content of hydroxyl groups bonded to Si atoms exceeds 0.5, the resulting resinous organopolysiloxane exhibits high hardness due to a condensation reaction during heat curing. On the other hand, a cured product having poor crack resistance is not preferable. On the other hand, if c is less than 0.001, the resulting resinous organopolysiloxane tends to have a high melting point, which may cause problems in workability, which is not preferable. The content of hydroxyl groups bonded to Si atoms in the component (A) is preferably 0.01 ≦ c ≦ 0.3, more preferably 0.05 ≦ c ≦ 0.2. In order to control the value of c to 0.001 ≦ c ≦ 0.5, it is preferable to set the complete condensation rate of the alkoxy group of the raw material to 86 to 96%. When the complete condensation rate is less than 86%, the value of c exceeds 0.5 and the melting point becomes low, and when it exceeds 96%, the value of c is less than 0.001 and the melting point tends to be too high. Absent.
Here, the complete condensation rate indicates the ratio of the number of moles in which all alkoxy groups contained in one molecule have been subjected to the condensation reaction with respect to the total number of moles of raw materials.

  From the above, in the average composition formula (1), the range of a + b + c is preferably 0.9 ≦ a + b + c ≦ 1.8, and more preferably 1.0 ≦ a + b + c ≦ 1.5.

In the average composition formula (1), R ¹ is an organic group having 1 to 4 carbon atoms, and examples thereof include alkyl groups such as a methyl group, an ethyl group, and an isopropyl group, and the availability of raw materials is easy. And a methyl group or an isopropyl group is preferable.

The resinous organopolysiloxane of component (A) preferably has a weight average molecular weight of 1,000 to 20,000, particularly preferably 1,500 to 10,000, more preferably 2, as converted to polystyrene standards by GPC measurement. 000-8,000. If the molecular weight is less than 1,000, the resulting resinous organopolysiloxane is difficult to solidify, and if the molecular weight exceeds 20,000, the resulting composition has too high a viscosity and fluidity decreases. Formability may deteriorate.
In addition, suppose that the weight average molecular weight mentioned in this invention refers to the weight average molecular weight which used polystyrene by the gel permeation chromatography (GPC) measured on the following conditions as a reference material.
[Measurement condition]
Developing solvent: Tetrahydrofuran Flow rate: 0.35 mL / min
Detector: RI
Column: TSK-GEL H type (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Sample injection volume: 5 μL

The component (A) represented by the above average composition formula (1) is generally Q unit (SiO _4/2 ), T unit (CH ₃ SiO _3/2 ), D unit ((CH ₃ ) ₂ SiO _2/2. ) And M units ((CH ₃ ) ₃ SiO _1/2 ). When the component (A) is represented by this expression, the ratio of the number of T units to the total number of all siloxane units is preferably 70% or more (70 to less than 100%), and 75% or more ( 75 to less than 100%) is more preferable, and 80% or more (less than 80 to 100%) is particularly preferable. When the content ratio of the T unit is less than 70%, the overall balance such as hardness, adhesion, and appearance of the obtained cured product may be lost. The balance may be M, D, and Q units, and the ratio of the total of these units to all siloxane units is 30% or less (0 to 30%), particularly more than 0% and 30% or less. Preferably it is less than 100%.

The component (A) represented by the average composition formula (1) can be obtained as a hydrolytic condensate of an organosilane represented by the following general formula (3).
(CH ₃ ) _n SiX _4-n (3)
(In the formula, X represents a halogen atom such as chlorine or an alkoxy group having 1 to 4 carbon atoms, and n is 0, 1, or 2.) In this case, X is solid at 25 ° C. From the viewpoint of obtaining the organopolysiloxane, a chlorine atom or a methoxy group is preferable.

  Examples of the silane compound represented by the above formula (3) include organotrichlorosilanes such as methyltrichlorosilane; organotrialkoxysilanes such as methyltrimethoxysilane and methyltriethoxysilane; disilanes such as dimethyldimethoxysilane and dimethyldiethoxysilane. Examples include organodialkoxysilanes; tetrachlorosilanes; tetraalkoxysilanes such as tetramethoxysilane and tetraethoxysilane.

  The hydrolysis and condensation of the silane compound having a hydrolyzable group may be performed by a usual method, but is preferably performed in the presence of a catalyst. As this catalyst, both an acid catalyst and an alkali catalyst can be used. For example, the acid catalyst is preferably an organic acid catalyst such as acetic acid, or an inorganic acid catalyst such as hydrochloric acid or sulfuric acid. The alkali catalyst is an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, or tetramethylammonium hydroxide. Organic alkali catalysts are preferred. As a specific example, when a silane containing a chloro group as a hydrolyzable group is used, a desired hydrocondensation product having an appropriate molecular weight can be obtained by using hydrogen chloride gas and hydrochloric acid generated by addition of water as a catalyst. Can be obtained.

  The amount of water used in the hydrolysis and condensation is generally 0 with respect to 1 mol of the total amount of hydrolyzable groups (for example, chloro group) in the silane compound having the hydrolyzable group. .9 to 1.6 mol, preferably 1.0 mol to 1.3 mol. When this addition amount satisfies the range of 0.9 to 1.6 mol, the composition described later is excellent in workability, and the cured product tends to be excellent in toughness.

  The silane compound having a hydrolyzable group is usually preferably used after being hydrolyzed in an organic solvent such as alcohols, ketones, esters, cellosolves, and aromatic compounds. Specifically, for example, alcohols such as methanol, ethanol, isopropyl alcohol, isobutyl alcohol, n-butanol, and 2-butanol, or aromatic compounds such as toluene and xylene are preferable. In view of the excellent toughness of the cured product, isopropyl alcohol, toluene, or an isopropyl alcohol / toluene combined system is more preferable.

  The reaction temperature for hydrolysis and condensation is preferably 10 to 120 ° C, more preferably 20 to 80 ° C. When the reaction temperature satisfies such a range, gelation is difficult, and a solid hydrolysis condensate that can be used in the next step is obtained.

  The organopolysiloxane of component (A) is preferably blended in an amount of 5 to 20% by mass, particularly 6 to 19% by mass, and further 7 to 17% by mass in the thermosetting silicone resin composition of the present invention. Is preferable.

<(B) Organopolysiloxane>
The thermosetting silicone resin composition of the present invention has a linear diorganopolysiloxane residue represented by the following formula (2) as component (B) for stress relaxation and crack resistance improvement. Organopolysiloxanes having at least one, preferably two or more cyclohexyl or phenyl groups in the molecule are used.

In the above formula (2), R ² is independently a group selected from a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group, a phenyl group, a vinyl group, and an allyl group. R ² is preferably a methyl group or a phenyl group. m is an integer of 5 to 50, preferably 8 to 40, more preferably 10 to 35. When m is less than 5, the obtained cured product tends to have poor crack resistance, and the device including the cured product may be warped. On the other hand, when m exceeds 50, the mechanical strength of the obtained cured product tends to be insufficient.

Component (B), in addition to the D unit represented by the above formula _{^{(2) (R 2 2 SiO}} 2/2), D units not corresponding to the above formula _{(2) (R 2 SiO 2/2} ), and M Units (R ₃ SiO _1/2 ) and / or T units (RSiO _3/2 ) may be included. The ratio of D unit: M unit: T unit is 90-24: 75-9: 50-1, respectively, 70-28: 70-20: 10-2 (however, the total of these units is 100). It is preferable from the cured | curing material characteristic. Here, R represents a hydroxyl group, a methyl group, an ethyl group, a propyl group, a cyclohexyl group, a phenyl group, a vinyl group or an allyl group. In addition to these, the component (B) may contain Q units (SiO _4/2 ). The organopolysiloxane of component (B) includes D unit (R ² ₂ SiO _2/2 ) of formula (2), D unit (R ₂ SiO _2/2 ) not corresponding to formula (2), M unit (R ₃ At least one cyclohexyl group or phenyl group is contained in one molecule in (SiO _1/2 ) and / or T unit (RSiO _3/2 ).

The D unit (R ² ₂ SiO _2/2 ) present in the organopolysiloxane of component (B) is preferably 30% or more (for example, 30 to 90%), particularly 50% or more (for example, 50 to 80%). ) Is preferably a continuous D unit (R ² ₂ SiO _2/2 ) represented by the general formula (2) in the molecule. Moreover, it is preferable that the polystyrene conversion weight average molecular weights by the gel permeation chromatography (GPC) of (B) component are 3,000-100,000, More preferably, it is 10,000-100,000. When the molecular weight is within this range, the component (B) is solid or semi-solid, which is preferable from the viewpoint of workability and curability of the resulting composition.

  The component (B) can be synthesized by combining the compounds used as raw materials for each of the above units in the resulting polymer so as to have a required molar ratio, for example, hydrolysis and condensation in the presence of an acid. .

Examples of the raw material of the D unit (R ² ₂ SiO _2/2 ) that forms the linear diorganopolysiloxane residue of the above formula (2) include the following.

(Here, an integer (average value) of m = 3 to 48, an integer (average value) of n = 0 to 48, and m + n is 3 to 48 (average value, and each repeating unit is a block even if it is a block) May be))

Examples of raw materials for T units (RSiO _3/2 ) include trichlorosilanes such as methyltrichlorosilane, ethyltrichlorosilane, propyltrichlorosilane, phenyltrichlorosilane, and cyclohexyltrichlorosilane, and trimethoxysilane corresponding to these trichlorosilanes. And alkoxysilanes such as

In addition, raw materials such as M unit and D unit not corresponding to the above formula (2) include Me ₂ PhSiCl, Me ₂ ViSiCl, Ph ₂ MeSiCl, Ph ₂ ViSiCl, Me ₂ SiCl ₂ , MeEtSiCl ₂ , ViMeSiCl ₂ , Ph _2. Examples thereof include mono- or dichlorosilanes such as SiCl ₂ and PhMeSiCl ₂ , and mono- or dialkoxysilanes such as mono- or dimethoxysilanes corresponding to each of these chlorosilanes. Here, Me represents a methyl group, Et represents an ethyl group, Ph represents a phenyl group, and Vi represents a vinyl group.

  (B) component can be obtained by combining these raw material compounds in a predetermined molar ratio and reacting them as follows, for example. Phenylmethyldichlorosilane, phenyltrichlorosilane, 21-terminal chlorodimethylsilicone oil having 21 Si atoms, and toluene are added and mixed, and the mixed silane is dropped into water and co-hydrolyzed at 30 to 50 ° C. for 1 hour. Then, after aging at 50 ° C. for 1 hour, water is added for washing, followed by azeotropic dehydration and polymerization at 25 to 40 ° C. using ammonia or the like as a catalyst, followed by filtration and vacuum stripping.

The (B) component organopolysiloxane has 0.5 to 10% silanol units (siloxane units having a silanol group), preferably about 1 to 5%, based on the total siloxane units. Examples of the silanol unit include an R (HO) SiO _2/2 unit, an R (HO) ₂ SiO _1/2 unit, and an R ₂ (HO) SiO _1/2 unit (where R is a hydroxyl group). The above-mentioned groups other than the group). Since the organopolysiloxane contains a silanol group, it undergoes a condensation reaction with the resinous polyorganosiloxane of the component (A) containing the hydroxyl group represented by the above formula (1).

<(C) Acrylic resin modifier>
In the thermosetting silicone resin composition of the present invention, in order to improve toughness, particularly flexibility, the weight average molecular weight having an alkoxysilyl group is 1,000 to 1,000 as a modifier of the component (C). An acrylic resin-based modifier that is 20,000 is blended. Moreover, you may use an acrylic resin type modifier individually or in combination of 2 or more types.

  The acrylic resin modifier is obtained by polymerizing a monomer mixture containing an alkoxysilyl group-containing acrylic monomer and a styrene monomer, an alkoxysilyl group-containing acrylic monomer, and other A monomer obtained by polymerizing a monomer mixture containing a vinyl monomer, or a monomer containing an alkoxysilyl group-containing acrylic monomer, styrene monomer and other vinyl monomers It is obtained by polymerizing the mixture.

Examples of the alkoxysilyl group-containing acrylic monomer include (meth) acrylic acid alkoxysilylalkyl ester.
Examples of the styrene monomer include styrene and α-methylstyrene.

Other vinyl monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ( (Meth) acrylic acid cyclohexyl, (meth) acrylic acid stearyl, (meth) acrylic acid alkyl ester having an alkyl group having 1 to 22 carbon atoms such as methoxyethyl (meth) acrylate, (meth) acrylic acid polyalkylene glycol ester , (Meth) acrylic acid alkoxyalkyl ester, (meth) acrylic acid hydroxyalkyl ester, (meth) acrylic acid dialkylaminoalkyl ester, (meth) acrylic acid benzyl ester, (meth) acrylic acid phenoxyalkyl ester, (meth) acrylic Isobornyl acid Tel and the like. Also, (meth) acrylamide, (meth) acryl dialkylamide, vinyl esters such as vinyl acetate, vinyl ethers, aromatic vinyl monomers such as (meth) allyl ethers, and α-olefin monomers such as ethylene and propylene Can also be used as a vinyl monomer. These vinyl monomers can be used by appropriately selecting one kind or two or more kinds.
The sequence of each unit derived from these monomers in the polymer of component (C) may be random, block, or graft.

  The weight average molecular weight of the acrylic resin modifier may be 1,000 to 20,000, preferably 1,500 to 20,000, and more preferably 2,000 to 15,000. If the weight average molecular weight is less than 1,000, the strength and crack resistance of the cured product of the thermosetting silicone resin composition may not be improved. On the other hand, when the weight average molecular weight exceeds 20,000, the compatibility of the acrylic resin modifier with the silicone resin may be greatly reduced. In addition, the weight average molecular weight of (C) component means the weight average molecular weight of standard polystyrene conversion measured by gel permeation chromatography (GPC).

The acrylic resin modifier as component (C) has an alkoxysilyl group. It is preferable to have two or more alkoxysilyl groups per molecule. When the number of Si in one molecule is defined as Si / _Mn ( _Mn : number average molecular weight), it is 0.001 to 0.7, preferably 0.002 to 0.6. If this range is not satisfied, the acrylic resin modifier may not be easily taken into the system, making it difficult to obtain a cured product having the expected toughness, and conversely, the crosslink density may be too high and become brittle.

  The acrylic resin modifier as component (C) can be produced by any method such as bulk polymerization, solution polymerization, and emulsion polymerization. A preferable polymerization method is a continuous stirring tank polymerization method, and a more preferable polymerization method is a high temperature continuous stirring tank polymerization method. The polymerization temperature is preferably 130 to 350 ° C, more preferably 150 to 330 ° C, and still more preferably 170 to 270 ° C. At the above polymerization temperature, a polymer having a target molecular weight (concept including a copolymer) can be efficiently obtained by using no radical polymerization initiator or chain transfer agent or using a very small amount. When the polymerization temperature is less than 130 ° C., a large amount of radical polymerization initiator and chain transfer agent are required to obtain a polymer having the desired molecular weight, and thus the resulting polymer contains a large amount of impurities. Cheap. On the other hand, when the polymerization temperature exceeds 350 ° C., thermal decomposition of the polymer occurs, and there is a possibility that the target polymer cannot be obtained.

  Examples of the (C) component acrylic resin modifier include, for example, ARUFON US-6100, 6170 (above, manufactured by Toagosei Co., Ltd.), Actflow NE-1000 (produced by Soken Chemical Co., Ltd.). Commercial products such as these can also be used.

  When the total amount of component (A), component (B) and component (C) is 100 parts by mass, component (A) is 70 to 95 parts by mass, component (B) is 2 to 30 parts by mass, (C ) Component is 2 to 20 parts by mass. (B) Preferably it is 5-20 mass parts as a compounding quantity of a component. When the blending amount of the component (B) is too small, the effect of improving the continuous moldability of the resulting composition is small, and it becomes difficult to achieve low warpage and crack resistance in the resulting cured product. On the other hand, if the amount of component (B) is large, the viscosity of the resulting composition tends to increase, which may hinder molding. The amount of component (C) is preferably 5 to 15 parts by mass. (C) If there is too little compounding quantity of a component, toughness will not be provided. On the other hand, when there are many compounding quantities of (C) component, it will become easy to raise | generate a hardening defect.

<(D) Inorganic filler>
The inorganic filler of component (D) is blended to increase the strength of the cured product of the silicone resin composition of the present invention. (D) As an inorganic filler of a component, what is normally mix | blended with a silicone resin composition or an epoxy resin composition can be used. For example, silicas such as spherical silica, fused silica and crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, glass fiber, glass particles, antimony trioxide and the like can be mentioned. White pigments (white colorants) are excluded.

(D) Although the average particle diameter and shape of the inorganic filler of a component are not specifically limited, An average particle diameter is 3-40 micrometers normally. As the component (D), spherical silica having an average particle size of 0.5 to 40 μm is preferably used. The average particle diameter is a value determined as a mass average value D ₅₀ (or median diameter) in particle size distribution measurement by laser diffraction method.

  In addition, from the viewpoint of increasing the fluidity of the resulting composition, inorganic fillers having a plurality of particle size ranges may be combined. In such a case, a fine region of 0.1 to 3 μm, a medium particle of 3 to 7 μm It is preferable to use a combination of spherical silica having a diameter region and a coarse region of 10 to 40 μm. For further high fluidization, it is preferable to use spherical silica having a larger average particle diameter.

  The filling amount of the inorganic filler of component (D) is 300 to 1,200 parts by mass, particularly 600 to 1,000 parts by mass, with respect to 100 parts by mass of the sum of components (A), (B) and (C). Part is preferred. If the amount is less than 300 parts by mass, sufficient strength may not be obtained. If the amount exceeds 1,200 parts by mass, unfilled defects due to thickening and flexibility are lost, resulting in defects such as peeling in the element. May occur. In addition, it is preferable to contain this inorganic filler in the range of 10-90 mass% of the whole composition, especially 20-80 mass%.

<(E) Organometallic condensation catalyst>
The (E) component organometallic condensation catalyst is a condensation catalyst for use in curing the resinous organopolysiloxane (A) and the organopolysiloxane (B), and the stability of the component (A). The film is selected in consideration of the hardness of the coating, non-yellowing, curability and the like. When organic compounds such as bases such as imidazole are used as the curing catalyst, the cured product is easily colored.
For example, as an organic metal condensation catalyst, an organic acid zinc, an organic aluminum compound, an organic titanium compound, or the like is preferably used. Specifically, zinc benzoate, zinc octylate, zinc p-tert-butylbenzoate, zinc laurate , Zinc stearate, aluminum triisopropoxide, aluminum acetylacetonate, ethyl acetoacetate aluminum di (normal butyrate), aluminum-n-butoxydiethylacetoacetate, tetrabutyl titanate, tetraisopropyl titanate, tin octylate , Cobalt naphthenate, tin naphthenate and the like. Of these, zinc benzoate is preferably used.

  The addition amount of the organometallic condensation catalyst is preferably 0.01 to 5 parts by mass, particularly preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the sum of the components (A), (B) and (C). 1.6 parts by mass. When the added amount satisfies this range, the curability is good and the storage stability is stable.

In the present invention, the following optional components can be blended in addition to the above components.
<(F) White pigment>
The white pigment of component (F) can be blended with the thermosetting silicone resin composition of the present invention in order to increase the whiteness necessary for applications such as reflectors (reflecting plates) for optical semiconductor devices. Examples of white pigments include titanium dioxide, rare earth oxides typified by yttrium oxide, zinc sulfate, zinc oxide, magnesium oxide, and the like, and these can be used alone or in combination of several kinds.

Among these, as the white pigment of the component (F), it is preferable to use titanium dioxide in order to further increase the whiteness. The unit cell of titanium dioxide includes a rutile type, an anatase type, and a brookite type, and any of them can be used, but it is preferable to use a rutile type from the viewpoint of the whiteness and photocatalytic ability of titanium dioxide. Moreover, although the average particle diameter and shape of titanium dioxide are not limited, the average particle diameter is preferably 0.05 to 5.0 μm, of which 1.0 μm or less is preferable and 0.30 μm or less is more preferable. In order to enhance the compatibility and dispersibility with the resin component and the inorganic filler, the titanium dioxide can be surface-treated in advance with a hydrous oxide such as aluminum or silicon, an organic substance such as polyol, or an organic polysiloxane. The average particle size is one calculated as a weight average value D ₅₀ of the particle size distribution measurement (or median diameter) by a laser diffraction method.

  The titanium dioxide production method may be any method such as a sulfuric acid method or a chlorine method, but the chlorine method is preferred from the viewpoint of whiteness.

  The blending amount of the white pigment is preferably 3 to 300 parts by mass, particularly preferably 5 to 250 parts by mass with respect to 100 parts by mass of the sum of the components (A), (B) and (C). When the blending amount of the white pigment is less than 3 parts by mass, sufficient whiteness may not be obtained, and when it exceeds 300 parts by mass, not only the ratio of other components added for the purpose of improving the mechanical strength is reduced, but also molding. Remarkably deteriorates. In addition, it is preferable to contain 1-50 mass% of this white pigment with respect to the whole thermosetting silicone resin composition which requires high whiteness like the reflector for optical semiconductor devices, More preferably It is the range of 3-40 mass%.

<(G) Release agent>
(G) The mold release agent of a component can be mix | blended with the thermosetting silicone resin composition of this invention, in order to improve the mold release property at the time of shaping | molding. (G) It is preferable to add a component so that it may contain 0.2-5.0 mass% with respect to the whole composition. Examples of the mold release agent include natural wax, acid wax, polyethylene wax, and synthetic wax typified by fatty acid wax, among which calcium stearate having a melting point of 120 to 140 ° C. is desirable.

<(H) coupling agent>
The coupling agent of component (H) increases the bonding strength between the resin and the inorganic filler, and improves the bonding strength to the plated metal substrate. Therefore, the thermosetting silicone resin composition of the present invention. Can be blended. Examples of the coupling agent (H) include a silane coupling agent and a titanate coupling agent.

  Specifically, for example, epoxy functional alkoxysilane such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, Use of a mercapto-functional alkoxysilane such as γ-mercaptopropyltrimethoxysilane is preferred from the standpoint that the resin does not change color even when left at high temperature.

  Component (H) is preferably blended in an amount of 0.1 to 8.0 parts by weight, particularly 0.5 to 6 parts per 100 parts by weight of the sum of components (A), (B) and (C). 0.0 part by mass is preferred. If it is less than 0.1 parts by mass, the adhesion effect to the substrate may not be sufficient, and if it exceeds 8.0 parts by mass, the viscosity may be extremely lowered, possibly causing voids. .

<Other additives>
Various additives can be further blended in the thermosetting silicone resin composition of the present invention as necessary. For example, for the purpose of improving the properties of the resin, other additives such as organopolysiloxane, silicone oil, thermoplastic resin, thermoplastic elastomer, organic synthetic rubber, or light stabilizer are added as long as the effects of the present invention are not impaired. Can be blended.

<Method for producing composition>
The composition of the present invention includes (A) component organopolysiloxane, (B) component organopolysiloxane, (C) component acrylic resin modifier (D) component inorganic filler, and (E ) Component organometallic condensation catalyst is blended at a predetermined composition ratio, and this is mixed sufficiently uniformly by a mixer or the like. If necessary, in addition to the above components, the white pigment of component (F) and other additives may be blended at a predetermined blending ratio. Thereafter, the mixture is subjected to a melt mixing process using a hot roll, a kneader, an extruder or the like, then cooled and solidified, and pulverized to an appropriate size to obtain a molding material for the silicone resin composition. The cured product of the silicone resin composition of the present invention has a linear expansion coefficient at 50 to 100 ° C. of 30 ppm / K or less, preferably 25 ppm / K or less.

  In addition, as described above, from the viewpoint of dispersibility, organopolysiloxane (A), organopolysiloxane (B), and acrylic resin modifier (C) as component (C) are pre-kneaded. It is preferable to melt and mix in the flask.

The most common molding method for the thermosetting silicone resin composition includes a transfer molding method and a compression molding method. In the transfer molding method, using a transfer molding machine, the molding pressure is 5 to 20 N / mm ² , the molding temperature is 120 to 190 ° C., the molding time is 30 to 500 seconds, and the molding temperature is 150 to 185 ° C., and the molding time is 30 to 180 seconds. It is preferable. In the compression molding method, a compression molding machine is used, and the molding temperature is preferably 120 to 190 ° C., the molding time is 60 to 600 seconds, and the molding temperature is preferably 130 to 160 ° C. and the molding time is 120 to 300 seconds. Further, in any molding method, post-curing may be performed at 150 to 200 ° C. for 2 to 20 hours.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

Each component used in Examples and Comparative Examples is shown below. In the following, the weight average molecular weight is measured under the following measurement conditions.
[Measurement condition]
Developing solvent: Tetrahydrofuran Flow rate: 0.35 mL / min
Detector: RI
Column: TSK-GEL H type (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Sample injection volume: 5 μL

<(A) Synthesis of Resin-like Organopolysiloxane>
[Synthesis Example 1]
100 parts by mass of methyltrichlorosilane and 200 parts by mass of toluene were placed in a 1 L flask, and a mixed liquid of 8 parts by mass of water and 60 parts by mass of isopropyl alcohol was added dropwise to the solution under ice cooling. The internal temperature was added dropwise over 5 hours while maintaining the range of -5 to 0 ° C, then heated and stirred at reflux temperature for 20 minutes. Then, the mixture was cooled to room temperature, and 12 parts by mass of water was added dropwise at 30 ° C. or less over 30 minutes, followed by stirring for 20 minutes. Further, 25 parts by mass of water was added dropwise, followed by stirring at 40 to 45 ° C. for 60 minutes. Thereafter, 200 parts by mass of water was added to separate the organic layer. The organic layer was washed until neutral, and then subjected to azeotropic dehydration, filtration, and stripping under reduced pressure, whereby a colorless transparent solid represented by the following average formula (A-1) (melting point: 76 ° C., weight average molecular weight: 3) , 060) 36.0 parts by mass of thermosetting organopolysiloxane (A-1) was obtained.
(CH ₃ ) _1.0 Si (OC ₃ H ₇ ) _0.07 (OH) _0.10 O _1.4 (A-1)

<(B) Synthesis of organopolysiloxane>
[Synthesis Example 2]
Phenylmethyldichlorosilane 100 g (4.4 mol%), phenyltrichlorosilane 2,100 g (83.2 mol%), dimethylpolysiloxane oil 2,400 g (12.4 mol%) of chloroblocked at both ends with 21 Si atoms ), 3,000 g of toluene, and the above silane mixed in 11,000 g of water was added dropwise and co-hydrolyzed in the range of 30 to 50 ° C. for 1 hour. Thereafter, after aging at 30 ° C. for 1 hour, water was added for washing, followed by azeotropic dehydration, filtration, and stripping under reduced pressure to obtain a colorless and transparent product (organosiloxane (B-1)). The siloxane (B-1) had a melt viscosity of 5 Pa · s at 150 ° C. using an ICI corn plate and a weight average molecular weight of 50,000.
[(Me ₂ SiO) ₂₁ ] _0.124 (PhMeSiO) _0.044 (PhSiO _1.5 ) _0.832 (B-1)

<(C-1) Acrylic resin modifier>
(C-1-1) Weight average molecular weight 2,500, Si number / Mn (number average molecular weight) ≈ 0.2 alkoxysilyl group-containing acrylic resin (ARUFON US-6100: trade name, manufactured by Toagosei Co., Ltd.)
(C-1-2) Alkoxysilyl group-containing acrylic resin having a weight average molecular weight of 3,000 and the number of Si / Mn≈0.5 (ARUFON US-6170: trade name, manufactured by Toagosei Co., Ltd.)
(C-1-3) Alkoxysilyl group-containing acrylic resin having a weight average molecular weight of 3,000 and the number of Si / Mn≈0.003 (Act Flow NE-1000: trade name manufactured by Soken Chemical Co., Ltd.)
<(C-2) Sample for Comparative Example>
(C-2-1) Acrylic block copolymer (alkoxy group-free PMMA-PBA-PMMA block copolymer; trade name: Nanostrength M52N: manufactured by Arkema Co., Ltd.)
(C-2-2) 3-acryloxypropyltrimethoxysilane (trade name: KBM-5013: manufactured by Shin-Etsu Chemical Co., Ltd.)
(C-2-3) Acrylic core-shell rubber particles (trade name: Metabrene W-5500: manufactured by Mitsubishi Rayon Co., Ltd.)

<(D) Inorganic filler>
(D-1) Fused spherical silica (trade name: CS-6103 53C2, manufactured by Tatsumori Co., Ltd., average particle size 10 μm)

<(E) Organometallic condensation catalyst>
(E-1) Zinc benzoate (Wako Pure Chemical Industries, Ltd.)

<(F) White pigment>
(F-1) Titanium dioxide rutile type (trade name: PC-3, manufactured by Ishihara Sangyo Co., Ltd.)

<(G) Release agent>
(G-1) Hardened castor oil (trade name: Kao wax 85P, manufactured by Kao Corporation)

<(H) Silane coupling agent>
(H-1) 3-Mercaptopropyltrimethoxysilane (trade name: KBM-803, manufactured by Shin-Etsu Chemical Co., Ltd.)

[Examples 1-5, Comparative Examples 1-8]
The composition (parts by mass) shown in Tables 1 and 2 was manufactured with a two-roll hot roll, cooled and pulverized to obtain a thermosetting silicone resin composition. The following properties were measured for these compositions. The results are shown in Tables 1 and 2.

<Spiral flow value>
Using a mold conforming to the EMMI standard, the spiral flow value of the molded body of the thermosetting silicone resin composition was determined under the conditions of a molding temperature of 175 ° C., a molding pressure of 6.9 N / mm ² , and a molding time of 120 seconds. It was measured.

<Bending strength, flexural modulus, deflection (25 ° C)>
The thermosetting silicone resin composition was molded using a mold conforming to JIS K 6911: 2006 standard at a molding temperature of 175 ° C., a molding pressure of 6.9 N / mm ² and a molding time of 120 seconds. Post cure at 4 ° C. for 4 hours. The post-cured molded body was measured at room temperature (25 ° C.) for flexural strength, flexural modulus and deflection.

<Coefficient of thermal expansion>
The above thermosetting silicone resin composition was molded using a mold conforming to the EMMI standard at a molding temperature of 175 ° C., a molding pressure of 6.9 N / mm ² , and a molding time of 120 seconds, and at 180 ° C. for 4 hours. Post cure. The thermal expansion coefficient of the test piece of the post-cured molded product was measured in the range of 50 ° C. to 100 ° C. by TMA (manufactured by TMA8310 Rigaku Corporation).

<Light reflectivity (initial light reflectivity, long-term heat resistance test)>
Under the conditions of a molding temperature of 175 ° C., a molding pressure of 6.9 N / mm ² , and a molding time of 120 seconds, a disk-shaped cured product having a diameter of 50 mm × thickness of 3 mm was prepared, and then post-cured at 180 ° C. for 4 hours. The initial light reflectance at 450 nm was measured using an X-rite 8200 manufactured by DG Corporation. Further, heat treatment was performed at 200 ° C. for 96 hours, and the light reflectance at 450 nm was measured using X-lite 8200 manufactured by SDG Co., Ltd. in the same manner.

As shown in Table 1, in the molded body (cured product) of the resin composition of the present invention, the amount of deflection was increased and the toughness was increased by adding an acrylic resin modifier. It was also confirmed that the fluidity was improved. It was also found that there was no adverse effect on heat resistance. Therefore, the molded body of the resin composition of the present invention was confirmed to be excellent in toughness and effective in improving fluidity. Therefore, it was confirmed that the composition of the present invention was useful as an optical semiconductor device material.

Claims (7)

A thermosetting silicone resin composition comprising the following components (A), (B), (C), (D) and (E): However, the mass part of each component is a mass part with respect to a total of 100 mass parts of (A), (B), and (C) component.
(A) Condensation reaction type resinous organopolysiloxane solid at 25 ° C .: 70 to 95 parts by mass (B) 1 molecule having a linear diorganopolysiloxane residue represented by the following general formula (2) Organopolysiloxane having at least one cyclohexyl group or phenyl group therein: 2 to 30 parts by mass
Wherein R ² is independently a monovalent hydrocarbon group selected from a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group, a phenyl group, a vinyl group and an allyl group, and m is 5 to 50 Indicates an integer.)
(C) Acrylic resin modifier having an alkoxysilyl group and a weight average molecular weight of 1,000 to 20,000: 2 to 20 parts by mass (D) Inorganic filler: 300 to 1,200 parts by mass (E) Organometallic condensation catalyst: 0.01 to 5 parts by mass   Furthermore, the thermosetting silicone resin composition of Claim 1 which contains 3-300 mass parts of white pigments as (F) component. The condensation reaction type resinous organopolysiloxane (A) is a resinous organopolysiloxane having a polystyrene-equivalent weight average molecular weight of 1,000 to 20,000 represented by the following average composition formula (1). The thermosetting silicone resin composition according to claim 1 or 2, characterized by the above.
(CH ₃ ) _a Si (OR ¹ ) _b (OH) _c O _{(4-abc) / 2} (1)
(In the formula, R ¹ represents the same or different organic group having 1 to 4 carbon atoms, and a, b and c are 0.8 ≦ a ≦ 1.5, 0 ≦ b ≦ 0.3, 0.001. ≦ c ≦ 0.5 and 0.801 ≦ a + b + c <2.   The case for optical semiconductor elements formed with the thermosetting silicone resin composition of any one of Claims 1-3.   An optical semiconductor device comprising the optical semiconductor element case according to claim 4.   A photocoupler sealed with the thermosetting silicone resin composition according to claim 1.   An optical semiconductor device comprising the photocoupler according to claim 6.