JP5728961B2 - White thermosetting silicone resin composition for optical semiconductor case formation and optical semiconductor case - Google Patents

Description

  The present invention relates to a white thermosetting silicone resin composition for forming an optical semiconductor case that provides a cured product with improved strength and excellent wear resistance, and an optical semiconductor case for an LED or the like comprising the cured product of 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. Polyphthalamide resin (PPA) is currently widely used as one of materials for semiconductor and electronic equipment devices such as LEDs. However, with the recent increase in output and shortening of the wavelength of optical semiconductor devices, PPA is not suitable as a resin used in the periphery of an optical semiconductor element because it causes severe deterioration and causes a decrease in optical output.

Japanese Patent Application Laid-Open No. 02-189958 (Patent Document 1) discloses a B-stage-shaped epoxy resin for encapsulating an optical semiconductor comprising an epoxy resin, a curing agent and a curing accelerator as constituents as an optical semiconductor encapsulating resin composition. An optical semiconductor device is described, which is a composition, and is composed of a cured body of a resin composition in which the above constituent components are uniformly mixed at a molecular level. In this case, as the epoxy resin, bisphenol A type epoxy resin or bisphenol F type epoxy resin is mainly used, and it is also described that triglycidyl isocyanate or the like can be used, but triglycidyl isocyanate is a bisphenol type in Examples. A small amount is added to the epoxy resin, and according to the study by the present inventors, this epoxy resin composition for B-stage semiconductor encapsulation has a problem that it turns yellow particularly when left at high temperature for a long time. is there.
In addition, JP-A 2000-196151, JP-A 2003-224305, and JP-A 2005-306952 (Patent Documents 2 to 4) disclose triazine derivative epoxy resins in epoxy resin compositions for sealing light-emitting elements. However, in all cases, the problem of yellowing after standing at high temperature for a long time has not been solved sufficiently.

  Furthermore, Japanese Patent Application Laid-Open No. 2006-77234 (Patent Document 5) describes a resin composition for sealing an LED element containing an organopolysiloxane excellent in ultraviolet resistance and a condensation catalyst. It is for applications that require higher transparency than applications using white pigments such as reflectors.

  Incidentally, in recent years, the size of a molded package such as a MAP (Matrix Array Package) method has been increased, and warping has become a major problem as the sealing resin is cured. This is because if the warpage is large, defects in the package transporting process and the cutting process occur. Each of the above compositions is not satisfactory in this respect.

  Furthermore, when a package is molded by the MAP method or the like, burrs are generated, and a process for removing the burrs is also required. The deburring process includes a method of washing with an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide (alkaline water washing treatment) and a method of irradiating with water and silica (blast treatment). When the alkaline water washing treatment is performed, the organopolysiloxane is eluted due to the characteristics of the silicone resin, so that the treatment is impossible. On the other hand, when the blasting is performed, the surface of the resin molded product is often greatly scraped due to the characteristics of the silicone resin, which may cause a decrease in light output and the like.

Japanese Patent Laid-Open No. 02-189958 JP 2000-196151 A JP 2003-224305 A JP 2005-306952 A JP 2006-77234 A

  The present invention has been made in view of the above circumstances, and for LEDs comprising a white thermosetting silicone resin composition for forming an optical semiconductor case that gives a cured product with improved strength and excellent wear resistance, and a cured product of the composition. An object of the present invention is to provide an optical semiconductor case.

（式中、Ｒ²及びＲ³は水酸基、又は炭素数１〜３のアルキル基、シクロヘキシル基、ビニル基、フェニル基及びアリル基から選ばれる一価炭化水素基であるが、Ｒ²、Ｒ³は同時に水酸基ではない。ｍは５〜５０を満たす数である。）
を必須成分とすることを特徴とする光半導体ケース形成用白色熱硬化性シリコーン樹脂組成物が、強度を向上させ、耐摩耗性に優れる硬化物を与えるので、ＬＥＤ用等の光半導体ケースに有用であることを見出し、本発明をなすに至った。 As a result of intensive studies to achieve the above object, the present inventors have
(A) Resinous organopolysiloxane represented by the following formula (1) and having a polystyrene-reduced weight average molecular weight of 500 to 20,000 by GPC: 100 parts by mass
(CH ₃ ) _a Si (OR ¹ ) _b (OH) _c O _{(4-abc) / 2} (1)
(Wherein R ¹ represents the same or different alkyl 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, 0.801 ≦ a + b + c <2, but the ratio of the number of moles of the T unit (CH ₃ SiO _3/2 ) is 70 mol% or more .)
(B) Potassium titanate having a wire diameter of 0.05 to 100 μm:
0.001-20% by weight of the total composition,
(C) White pigment containing a rare earth oxide: 3-200 parts by mass,
(D) Inorganic filler (except potassium titanate and white pigment):
400 to 1,000 parts by mass,
(E) Organometallic catalyst: 0.01 to 10 parts by mass,
(F) Organopolysiloxane containing 50 mol% or more of the total siloxane unit in the structure represented by the following formula (2): 2 to 50 parts by mass

(Wherein, R ² and R ³ are hydroxyl, or an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group, a vinyl group, is a monovalent hydrocarbon group selected from a phenyl group and an allyl group, R ^2, R ³ Are not hydroxyl groups at the same time, m is a number satisfying 5-50.)
A white thermosetting silicone resin composition for forming an optical semiconductor case characterized by having an essential component as an essential component provides a cured product with improved strength and excellent wear resistance, so it is useful for optical semiconductor cases for LEDs, etc. As a result, the present invention has been made.

（式中、Ｒ²及びＲ³は水酸基、又は炭素数１〜３のアルキル基、シクロヘキシル基、ビニル基、フェニル基及びアリル基から選ばれる一価炭化水素基であるが、Ｒ²、Ｒ³は同時に水酸基ではない。ｍは５〜５０を満たす数である。）
を必須成分とすることを特徴とする光半導体ケース形成用白色熱硬化性シリコーン樹脂組成物。
請求項２：
請求項１記載の熱硬化性シリコーン樹脂組成物の硬化物からなる光半導体ケース。 Accordingly, the present invention provides the following white thermosetting silicone resin composition for forming an optical semiconductor case and an optical semiconductor case.
Claim 1:
(A) Resinous organopolysiloxane represented by the following formula (1) and having a polystyrene-reduced weight average molecular weight of 500 to 20,000 by GPC: 100 parts by mass
(CH ₃ ) _a Si (OR ¹ ) _b (OH) _c O _{(4-abc) / 2} (1)
(Wherein R ¹ represents the same or different alkyl 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, 0.801 ≦ a + b + c <2, but the ratio of the number of moles of the T unit (CH ₃ SiO _3/2 ) is 70 mol% or more .)
(B) Potassium titanate having a wire diameter of 0.05 to 100 μm:
0.001-20% by weight of the total composition,
(C) White pigment containing a rare earth oxide: 3-200 parts by mass,
(D) Inorganic filler (except potassium titanate and white pigment):
400 to 1,000 parts by mass,
(E) Organometallic catalyst: 0.01 to 10 parts by mass,
(F) Organopolysiloxane containing 50 mol% or more of the total siloxane unit in the structure represented by the following formula (2): 2 to 50 parts by mass

(Wherein, R ² and R ³ are hydroxyl, or an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group, a vinyl group, is a monovalent hydrocarbon group selected from a phenyl group and an allyl group, R ^2, R ³ Are not hydroxyl groups at the same time, m is a number satisfying 5-50.)
A white thermosetting silicone resin composition for forming an optical semiconductor case, comprising:
Claim 2:
An optical semiconductor case comprising a cured product of the thermosetting silicone resin composition according to claim 1.

  According to the present invention, a white thermosetting silicone resin composition for forming an optical semiconductor case that provides a cured product with improved strength and excellent wear resistance, and an optical semiconductor case for an LED or the like comprising the cured product of the composition. Can be provided.

Hereinafter, the present invention will be described in more detail.
(A) Organopolysiloxane The organopolysiloxane (A) component is represented by the following formula (1). For example, the weight average molecular weight in terms of polystyrene by gel permeation chromatography (GPC) using toluene or the like as a developing solvent. Is a resinous (that is, branched or three-dimensional network structure) organopolysiloxane having a molecular weight of 500 to 20,000, and forms a cross-linked structure in the presence of an organometallic catalyst as the component (E) described later.
(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)

  An organopolysiloxane having a methyl group content (that is, a molar ratio to the number of silicon atoms in the molecule; the same shall apply hereinafter) having an a of less than 0.8 is too hard to be cured of a silicone resin composition containing the organopolysiloxane. Therefore, problems such as poor crack resistance tend to occur, which is not preferable. On the other hand, a resin in which a exceeds 1.5 is not solidified. Preferably, 0.9 ≦ a ≦ 1.2, more preferably 0.9 ≦ a ≦ 1.1.

  When b which shows content of organooxy groups, such as an alkoxy group, exceeds 0.3, molecular weight will become small and crack resistance will fall in many cases. Preferably it is 0.001 <= b <= 0.2, More preferably, it is 0.01 <= b <= 0.1.

  Organopolysiloxane with c exceeding 0.5 indicating the content of hydroxyl group bonded to Si atom has high hardness due to condensation reaction during heat curing and / or condensation reaction with component (F) described later. On the other hand, it gives a cured product with poor crack resistance. On the other hand, organopolysiloxanes with c less than 0.001 tend to have a high melting point, which may cause problems in workability. Further, when there is no bond formation with the component (F) described later, the cured product is not fixed in the cured product. As a result, the hardness of the cured product tends to be low and the solvent resistance tends to be poor. Preferably 0.01 ≦ c ≦ 0.3, and more preferably 0.05 ≦ c ≦ 0.2. As a condition for controlling c, it is preferable that the complete condensation rate of the organooxy group such as an alkoxy group as a raw material is 86 to 96%. If it is less than 86%, the melting point is low, and if it exceeds 96%, the melting point is high. It tends to be too much.

  From the above, preferably 0.911 ≦ a + b + c ≦ 1.8, and more preferably 1.0 ≦ a + b + c ≦ 1.5.

In the above formula (1), R ¹ is an organic group having 1 to 4 carbon atoms, such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, an isobutyl group, an alkyl group such as a tert- butyl group, An alkenyl group such as a vinyl group and an allyl group can be used, and an alkyl group is preferable, and a methyl group and an isopropyl group are particularly preferable in terms of easy availability of raw materials.

  The component (A) has a weight average molecular weight of 500 to 20,000, preferably 1,000 to 10,000, more preferably 2,000 to 8,000, as converted by polystyrene standard measured by GPC using toluene as a solvent. It is. Organopolysiloxanes having a molecular weight of less than 500 are difficult to solidify, and those having a molecular weight of more than 20,000 may have a too high viscosity, resulting in poor fluidity and poor moldability.

The component (A) is a combination of a Q unit (SiO _4/2 ), a branched unit selected from T units (CH ₃ SiO _3/2 ), and a D unit ((CH ₃ ) ₂ SiO _2/2 ). Can be expressed. When the component (A) is represented by this expression, the ratio of the number of moles of T units to the total number of moles of all siloxane units is 70 mole% or more, desirably 75 mole% or more, particularly 80 mole% or more. It is preferable that If the T unit is less than 70 mol%, the overall balance of hardness, adhesion, and appearance may be lost. The balance may be D and Q units, and these are preferably 30 mol% or less.

The component (A) can be obtained as a hydrolytic condensate of organosilane represented by the following formula (3).
(CH ₃ ) _n SiX _4-n (3)
(In the formula, X is a halogen atom such as a chlorine atom or an alkoxy group having 1 to 4 carbon atoms, and n is 0, 1, or 2, in order to make the T unit 70 mol% or more. , N = 1 organosilane is preferably used as the main component (70 mol% or more).
In this case, X is preferably a halogen atom, particularly a chlorine atom, from the viewpoint of obtaining a solid organopolysiloxane.

  In the silane compound represented by the above formula (3), examples of the silane compound with n = 1 include methyltrichlorosilane, methyltrimethoxysilane, methyltriethoxysilane, and the like. Examples of the silane compound with n = 0 include tetrachlorosilane. , Tetramethoxysilane, tetraethoxysilane, and n = 2 silane compounds include dimethyldichlorosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and the like.

  Hydrolysis and condensation of the above-mentioned silane compound having a hydrolyzable group may be carried out by a usual method. For example, an acid catalyst such as acetic acid, hydrochloric acid or sulfuric acid, or sodium hydroxide, potassium hydroxide or tetramethylammonium hydroxy It is preferable to carry out in the presence of an alkali catalyst such as copper. For example, when a silane containing a chloro group as a hydrolyzable group is used, a desired hydrolysis condensate having an appropriate molecular weight can be obtained using hydrogen chloride gas and hydrochloric acid generated by addition of water as a catalyst.

  If the total amount of water used during hydrolysis and condensation and the total amount of hydrolyzable groups (for example, chloro group) in the silane compound having hydrolyzable groups is 1 mol, generally Is 0.9 to 1.6 mol, preferably 1.0 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 is 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, and toluene and xylene are preferred as aromatic compounds, and the curability of the composition and the toughness of the cured product are preferred. Therefore, isopropyl alcohol, toluene, and isopropyl alcohol / toluene combined system are more preferable.

  The reaction temperature for hydrolysis and condensation is preferably 10 to 120 ° C, more preferably 20 to 100 ° C. When the reaction temperature satisfies this range, a solid hydrolysis condensate that can be used in the next step is obtained without gelation.

(B) Potassium titanate The silicone resin composition of the present invention contains potassium titanate as the component (B). Such potassium titanate is preferably a whisker and is added not only to increase the strength and toughness of the molded product, but also to improve the wear resistance against blasting and the like. However, single crystal whiskers are suitable for obtaining excellent high strength.

  The average fiber diameter of potassium titanate is 0.05 to 100 μm, more preferably 0.1 to 1.0 μm, and the average fiber length is 0.1 to 1,000 μm, more preferably 1.0 to 100 μm. is there. If the average fiber diameter is less than 0.05 μm, sufficient strength and toughness cannot be obtained, and if it exceeds 100 μm, the smoothness of the surface tends to deteriorate, and the microscopic uniform dispersibility of the whisker is impaired. There is a tendency to become easily. On the other hand, if the average fiber length exceeds 1,000 μm, it does not disperse with other components, and sufficient fluidity may not be obtained.

  Depending on the type of resin, it is necessary to consider the alkalinity of potassium titanate. For example, in the case of a silicone resin, if the alkalinity is too strong, the moldability and fluidity are often significantly inferior. This is because the silicone resin is cured by the alkalinity of potassium titanate.

  The compounding quantity of potassium titanate is 0.001-20 mass% with respect to the whole composition, especially the sum total of (A)-(F) component (or the sum total of (A)-(H) component), Preferably Is 0.01-15 mass%. If the blending amount is less than 0.001% by mass, sufficient strength and toughness cannot be obtained. On the other hand, if it exceeds 20% by mass, the fluidity may be remarkably inferior.

(C) White pigment The silicone resin composition of the present invention is blended with a white pigment as component (C) in order to increase the whiteness of the cured product for applications such as reflectors (reflecting plates) of optical semiconductor devices. As the white pigment, rare earth oxides such as titanium dioxide, alumina, yttrium oxide, zinc sulfate, zinc oxide, magnesium oxide and the like can be used alone or in combination of two or more white pigments. Among these, it is preferable that the component (C) contains a rare earth oxide from the viewpoint that a high reflectance in a short wavelength region of 350 to 400 nm can be secured.

The average particle diameter of the white pigment is 0.05 to 10 μm, preferably 0.1 to 5.0 μm, more preferably 0.1 to 1.0 μm. The white pigment is an inorganic substance (metal oxide) such as alumina or silica in order to improve compatibility and dispersibility with the component (A), the resin component (F) described later, and the inorganic filler (D). Etc.) or an organic substance such as an organosilicon compound such as a silane coupling agent. The average particle diameter can be determined as a cumulative weight average value D ₅₀ (or median diameter) in particle size distribution measurement by laser diffraction method.

  The compounding quantity of a white pigment is 3-200 mass parts with respect to 100 mass parts of (A) component, Preferably it is 5-150 mass parts. If the amount is less than 3 parts by mass, sufficient whiteness may not be obtained. On the other hand, when the amount exceeds 200 parts by mass, not only the ratio of other components added for the purpose of improving the mechanical strength is decreased, but also the moldability may be significantly lowered. In addition, the compounding amount of the white pigment is preferably 1 with respect to the entire white thermosetting silicone resin composition, in particular, the sum of the components (A) to (F) (or the sum of the components (A) to (H)). It is -50 mass%, More preferably, it is the range of 3-30 mass%.

(D) Inorganic filler In the silicone resin composition of the present invention, an inorganic filler other than the components (B) and (C) is further blended as the component (D). As such an inorganic filler, what is normally mix | blended with an epoxy resin composition can be used. Examples include silicas such as fused silica and crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, antimony trioxide, and the like, but the above-described component (B) potassium titanate and component (C) White pigments (white colorants) are excluded. Although the average particle diameter and shape of these inorganic fillers are not particularly limited, the average particle diameter is usually 3 to 40 μm. The average particle diameter can be determined as a cumulative weight average value D ₅₀ (or median diameter) in particle size distribution measurement by laser diffraction method.

  In particular, silica-based inorganic fillers such as fused silica and fused spherical silica are preferably used, and the particle size is not particularly limited, but the average particle size is 4 to 40 μm in terms of moldability and fluidity, In particular, 7 to 35 μm is preferable. Moreover, in order to obtain high fluidization, it is preferable to use a combination of a fine region of 0.1 to 3 μm, a medium particle size region of 4 to 8 μm, and a coarse region of 10 to 40 μm.

Inorganic fillers other than the above components (B) and (C) are silane in order to increase the bond strength between the resin component such as the component (A) and the component (F) described later, and the white pigment of the component (C). You may mix | blend what was surface-treated beforehand with coupling agents, such as a coupling agent and a titanate coupling agent.
Examples of such a coupling agent include epoxy functions such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. Functional alkoxysilanes such as N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and γ-mercapto It is preferable to use a mercapto functional alkoxysilane such as propyltrimethoxysilane. The amount of the coupling agent used for the surface treatment and the surface treatment method are not particularly limited, but those that do not discolor the treated filler when left at 150 ° C. or higher are preferred.

  The blending amount of the inorganic filler other than the components (B) and (C) is preferably 400 to 1,000 parts by mass, particularly 600 to 950 parts by mass with respect to 100 parts by mass of the total amount of the (A) silicone resin. If the amount is less than 400 parts by mass, sufficient strength may not be obtained. If the amount exceeds 1,000 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 the compounding quantity of inorganic fillers other than this (B) and (C) component in 10-90 mass% of the whole composition, especially 20-80 mass%.

(E) Organometallic catalyst The organometallic catalyst (E) component is a condensation catalyst for use in curing the component (A), and the stability of the component (A), the hardness of the coating, non-yellowing, and curing. It is selected in consideration of sex and the like. As such an organometallic catalyst, for example, an organic acid zinc, a Lewis acid catalyst, an organoaluminum compound, an organic titanium compound and the like are preferably used. Specifically, zinc benzoate, zinc octylate, p-tert-butylbenzoate Zinc acid, zinc laurate, zinc stearate, aluminum chloride, aluminum perchlorate, aluminum phosphate, aluminum triisopropoxide, aluminum acetylacetonate, ethyl acetoacetate aluminum di (normal butyrate), aluminum-n-butoxy Examples include diethyl acetoacetate, 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 catalyst is 0.01 to 10 parts by mass, preferably 0.1 to 1.6 parts by mass with respect to 100 parts by mass of the high molecular weight organopolysiloxane. When the added amount satisfies this range, the curability is good and stable.

(F) Organopolysiloxane The organopolysiloxane (F) component is an organopolysiloxane having a structure composed of repeating bifunctional siloxane units (D units) represented by the following formula (2).

In the formula, R ² and R ³ are independently of each other a hydroxyl group or an alkyl group having 1 to 3 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a cyclohexyl group, a vinyl group, a phenyl group, and an allyl group. (Wherein R ² and R ³ are not hydroxyl groups at the same time), preferably an alkyl group such as a methyl group and a phenyl group. m is an integer of 5 to 50, preferably 8 to 40, more preferably 10 to 35. If m is less than 5, the cured product has poor crack resistance and may cause warping of the case. On the other hand, when m exceeds 50, the mechanical strength tends to be insufficient.

The component (F) includes M units (R ₃ SiO _1/2 ) and T units (RSiO _3/2 ) in addition to the D units (R ² R ³ SiO _2/2 ) represented by the above formula (2). May contain. These molar ratios are 90-24: 75-0: 50-1, particularly 70-28: 70-20: 10-2 (provided that the following Q units: When it is not included, a total of 100) is preferable from the properties of the cured product. 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 some cases, the ( F ) component may optionally contain Q units (SiO ₂ ).

(F) The linear diorganopolysiloxane structure represented by the above formula (2) is preferably 30 mol% or more, particularly 50 mol% or more in the molecule per total siloxane unit in the organopolysiloxane component. The D unit (R ² R ³ SiO _2/2 ) is preferably formed. In addition, although there is no restriction | limiting in particular in an upper limit, Usually, 99.5 mol% or less, Preferably it is 99 mol% or less, More preferably, about 95 mol% or less may be sufficient. Moreover, it is preferable that the polystyrene conversion weight average molecular weights by the gel permeation chromatography (GPC) of (F) component are 3,000-100,000, More preferably, it is 10,000-100,000. Within this range, the polymer is solid or semi-solid, which is preferable from the viewpoint of workability and curability.

The component (F) can be synthesized by combining the compounds used as raw materials for 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. .

Here, as a raw material of the T unit (RSiO _3/2 ), chlorosilanes such as MeSiCl ₃ , EtSiCl ₃ , PhSiCl ₃ , propyltrichlorosilane, cyclohexyltrichlorosilane, and methoxysilanes corresponding to these chlorosilanes are used. Examples include alkoxysilanes. Me represents a methyl group, Et represents an ethyl group, and Ph represents a phenyl group.

As a raw material of the D unit (R ² R ³ SiO _2/2 ) of the above formula (2),

  Here, m is an integer of 3 to 48 (average value), n is an integer of 0 to 45 (average value), and m + n is 3 to 48 (average value). Me represents a methyl group, Et represents an ethyl group, and Ph represents a phenyl group.

Moreover, as raw materials for M units, T units, etc., chlorosilanes such as Me ₂ PhSiCl, Me ₂ ViSiCl, MePhSiCl ₂ , MeViSiCl ₂ , Ph ₂ MeSiCl, Ph ₂ ViSiCl, PhViSiCl ₂ , and these chlorosilanes, respectively. Examples include alkoxysilanes such as methoxysilanes. Me represents a methyl group, Et represents an ethyl group, Ph represents a phenyl group, and Vi represents a vinyl group.

  These raw materials can be combined in a predetermined molar ratio and obtained, for example, by the following reaction. 100 parts by weight of phenylmethyldichlorosilane, 1,900 parts by weight of phenyltrichlorosilane, 2,400 parts by weight of chlorodimethylsilicone oil having both ends of 21 Si, and 3,000 parts by weight of toluene are mixed in, and 11,000 parts by weight of water. The mixed silane is dropped into the part and co-hydrolyzed at 30 to 50 ° C. for 1 hour. Thereafter, after aging at 50 ° C. for 1 hour, water is added for washing, followed by azeotropic dehydration, filtration, and vacuum stripping.

In addition, when manufacturing by the said cohydrolysis and condensation, the siloxane unit which has a silanol group may be contained. The organopolysiloxane of component ( F ) usually contains such a silanol group-containing siloxane unit in an amount of usually 0.5 to 10 mol, preferably about 1 to 5 mol, based on all siloxane units. Examples of the silanol group-containing siloxane units include R (HO) SiO _2/2 units, R (HO) ₂ SiO _1/2 units, and R ₂ (HO) SiO _1/2 units (R is a hydroxyl group). is not). Since the organopolysiloxane contains a silanol group, it reacts with the curable polyorganosiloxane of component (A).

  (F) The compounding quantity of a component is 2-50 mass parts with respect to 100 mass parts of (A) component, Preferably it is 3-30 mass parts. If the blending amount is small, the effect of improving the continuous moldability is small, and low warpage cannot be achieved. When the addition amount is large, the viscosity of the composition increases, which may hinder molding.

In addition to the above components, the present invention can contain the following components.
(G) Mold Release Agent The silicone resin composition of the present invention can optionally contain an internal mold release agent as the component (G) as necessary. The component (G) is blended in order to improve the releasability at the time of molding, and is 0 to 5.0% by mass, preferably 0.2 to 5.0% by mass with respect to the total composition. It is to be added. As the internal mold release agent, there are natural wax, acid wax, polyethylene wax, synthetic wax typified by fatty acid wax, etc., among which calcium stearate having a melting point of 120 to 140 ° C. is preferably used.

(H) Coupling agent In the silicone resin composition of the present invention, as the component (H), a coupling agent such as a silane coupling agent or a titanate coupling agent is used to increase the bond strength between the resin and the inorganic filler. Can be optionally blended as necessary.
Examples of such a coupling agent include epoxy functions such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. Functional alkoxysilanes such as N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and γ-mercapto It is preferable to use a mercapto functional alkoxysilane such as propyltrimethoxysilane. The amount of coupling agent used for the surface treatment and the surface treatment method are not particularly limited.

  (B) When mix | blending (H) component, the compounding quantity is 0.1-8.0 mass parts with respect to 100 mass parts of (A) component, Preferably it is 0.5-6.0 mass parts. . If the amount 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 reduced, which may cause voids. .

Other Additives Various additives can be further blended in the silicone resin composition of the present invention as necessary. For example, additives such as various silicone powders, thermoplastic resins, thermoplastic elastomers, and organic synthetic rubbers can be added and blended within the range not impairing the effects of the present invention for the purpose of improving the properties of the resin.

Manufacturing method of composition As a manufacturing method of the white thermosetting silicone composition for optical semiconductor case formation of this invention, said (A)-(F) component, (G), (H) component as needed, and After blending other additives at a predetermined composition ratio and mixing them sufficiently uniformly with a mixer, etc., perform a melt mixing process with a hot roll, a kneader, an extruder, etc., and then cool and solidify to an appropriate size. It can grind | pulverize and it can be set as the molding material of a silicone resin composition.

Optical semiconductor case The composition obtained in this way is used to form a case as a reflector of an optical semiconductor such as an LED.
The most common molding method for such a reflector 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 30 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 185 ° C. for 2 to 20 hours.
The cured product of the composition obtained in this way has a linear expansion coefficient exceeding the glass transition temperature of 30 ppm / K or less, preferably 25 ppm / K or less.

  The light reflectance at a wavelength of 450 nm of the reflector thus obtained is 70% or more, particularly 75% or more, particularly 80% or more as an initial value. When the light reflectance is less than 70%, for example, the service life as an LED semiconductor element reflector is shortened. In addition, the measuring method of a reflectance produces the square-shaped hardened | cured material sample of 50 mm x 50 mm x 0.35 mm (thickness), for example, the spectrophotometer X-rite 8200 by SDG Co., Ltd., etc. Can be measured.

  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.

The raw materials used in Examples and Comparative Examples are shown below.
(A) 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 dropped at -5 to 0 ° C over 5 to 20 hours, then heated and stirred at reflux temperature for 20 minutes. Then, the mixture was cooled to room temperature, 12 parts by mass of water was added dropwise at 30 ° C. or lower for 30 minutes, and stirred 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 of water was added to separate the organic layer. The organic layer was washed until neutral, then azeotropically dehydrated, filtered, and stripped under reduced pressure to give a colorless and transparent solid having a basic structure of (CH ₃ ) SiO _3/2 units represented by the following formula ( A thermosetting organopolysiloxane (A-1) having a melting point of 76 ° C. and a weight average molecular weight of 3,600) of 36.0 parts by mass was obtained.
(CH ₃ ) _1.0 Si (OC ₃ H ₇ ) _0.07 (OH) _0.10 O _1.4

(B) Inorganic whiskers The following inorganic whiskers (B-1) and (B-2) were prepared.
B-1: Potassium titanate (Tismo N: trade name, manufactured by Otsuka Chemical Co., Ltd., wire diameter 0.5 μm, length 10 μm)
B-2: Glass fiber (FMT-25F: Fukushima Ceramic Co., Ltd. trade name, wire diameter 10 μm, length 260 μm)

(C) White pigment [Synthesis Example 2]
Yttrium oxide particles having an average particle size of 5 μm (manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with water and adjusted to pH 10 using sodium hydroxide, to prepare a slurry of 300 g / 1 L as the mass of yttrium oxide. The slurry is stirred at 80 ° C., 2% by mass of sodium aluminate as alumina is added to the mass of the yttrium oxide particles, and then neutralized to about pH 7 with 1N sulfuric acid over 1 hour. A coating of alumina was formed on the surface of the particles. The yttrium oxide particles on which the alumina coating layer was formed were separated by filtration, washed with water, dried at 120 ° C. for 16 hours, and pulverized with a ball mill for 30 minutes to obtain an yttrium oxide pigment (C-1).

(D) Inorganic filler The following inorganic filler (D-1) was prepared.
D-1: Fused spherical silica: MSR-4500TN (manufactured by Tatsumori Co., Ltd.)
(E) Organometallic catalyst The following organometallic catalyst (E-1) was prepared.
E-1: Zinc benzoate (manufactured by Wako Pure Chemical Industries, Ltd.)

単位からなる１５０℃での溶融粘度５Ｐａ・ｓ、無色透明のオルガノポリシロキサン（Ｆ−１）を得た。 (F) Organopolysiloxane [Synthesis Example 3]
Phenylmethyldichlorosilane 100 g (4.4 mol%), phenyltrichlorosilane 2,100 g (83.2 mol%), chlorodimethylsilicone oil 2,400 g (12.4 mol%) having 21 Si atoms, toluene 3,000 g was mixed, and the above silane and silicone oil mixed in 11,000 g of water were added dropwise and co-hydrolyzed at 30-50 ° C. for 1 hour. After aging at 50 ° C. for 1 hour, water was added for washing, followed by azeotropic dehydration, filtration, and vacuum stripping to obtain (C ₆ H ₅ ) (CH ₃ ) SiO _2/2 units, (C ₆ H ₅ ) SiO _3/2 units and

A colorless and transparent organopolysiloxane (F-1) having a melt viscosity of 5 Pa · s at 150 ° C. composed of units was obtained.

(G) Release agent The following release agent (G-1) was prepared.
G-1: Calcium stearate (manufactured by Wako Pure Chemical Industries, Ltd.)

[ Reference Examples 1 to 3, Comparative Example 1]
In the formulation (parts by mass) shown in Table 1, (A) organopolysiloxane, (B) inorganic whisker, (C) white pigment, (D) inorganic filler, (E) organometallic catalyst, (F) organopolysiloxane , (G) A release agent was blended, produced with a two-roll, cooled and pulverized to obtain a white silicone resin composition.

The following properties were measured for these compositions. The results are shown in Table 1. All moldings were performed by a transfer molding machine 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.

Using a mold conforming to the spiral flow value EMMI standard, the molding temperature was 175 ° C., the molding pressure was 6.9 N / mm ² , and the molding time was 120 seconds.

Using a melt viscosity increasing flow tester, the viscosity was measured at a temperature of 175 ° C. using a nozzle having a diameter of 1 mm under a pressure of 25 kgf / cm ² .

Bending strength and flexural modulus Using a mold conforming to the JIS-K6911 standard, a test piece molded under conditions of a molding temperature of 175 ° C., a molding pressure of 6.9 N / mm ² and a molding time of 120 seconds is room temperature (25 ° C. ) To measure the bending strength.

A square cured product having a side of 50 mm and a thickness of 0.35 mm was produced under conditions of a light reflectance molding temperature of 175 ° C., a molding pressure of 6.9 N / mm ² , and a molding time of 120 seconds. ) 400 and 450 nm light reflectivities were measured using an X-rite 8200.

A cured product of 5 mm × 5 mm × 15 mm was molded under conditions of a linear expansion coefficient molding temperature of 175 ° C., a molding pressure of 6.9 N / mm ² and a molding time of 120 seconds, and post-cured at 180 ° C. for 4 hours. Thereafter, the linear expansion coefficient was measured with a TMA8140C manufactured by Rigaku under the condition of a heating rate of 5 ° C./min.

Deburring difference measurement 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 square cured product having a side of 50 mm and a thickness of 0.35 mm is produced, and water and silica are injected. Thus, blasting was performed, and the deburring difference was measured.

As shown in Table 1, it was found that the addition of potassium titanate increases the bending strength. Potassium titanate of Reference Example 2 and the amount of glass fiber of Comparative Example 1 were the same volume, and this also confirmed the improvement in strength due to the addition of potassium titanate. It was also confirmed that the wear resistance was improved because the deburring difference during the blasting treatment was reduced by the addition of potassium titanate. Therefore, it was confirmed that the composition of the reference example was useful for the optical semiconductor case.

Claims (2)

(A) Resinous organopolysiloxane represented by the following formula (1) and having a polystyrene-reduced weight average molecular weight of 500 to 20,000 by GPC: 100 parts by mass
(CH ₃ ) _a Si (OR ¹ ) _b (OH) _c O _{(4-abc) / 2} (1)
(Wherein R ¹ represents the same or different alkyl 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, 0.801 ≦ a + b + c <2, but the ratio of the number of moles of the T unit (CH ₃ SiO _3/2 ) is 70 mol% or more .)
(B) Potassium titanate having a wire diameter of 0.05 to 100 μm:
0.001-20% by weight of the total composition,
(C) White pigment containing a rare earth oxide: 3-200 parts by mass,
(D) Inorganic filler (except potassium titanate and white pigment):
400 to 1,000 parts by mass,
(E) Organometallic catalyst: 0.01 to 10 parts by mass,
(F) Organopolysiloxane containing 50 mol% or more of the total siloxane unit in the structure represented by the following formula (2): 2 to 50 parts by mass

(Wherein, R ² and R ³ are hydroxyl, or an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group, a vinyl group, is a monovalent hydrocarbon group selected from a phenyl group and an allyl group, R ^2, R ³ Are not hydroxyl groups at the same time, m is a number satisfying 5-50.)
A white thermosetting silicone resin composition for forming an optical semiconductor case, comprising:   An optical semiconductor case comprising a cured product of the thermosetting silicone resin composition according to claim 1.