JP3523098B2 - Addition-curable silicone composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to protection of an optical device or a semiconductor device capable of forming a rubber-like elastic body or a gel-cured product having excellent elasticity and low elasticity and high transparency.
The present invention relates to an addition-curable silicone composition for sealing and a cured product thereof.

[0002]

2. Description of the Related Art Conventionally, a soft rubber-like elastic body or gel-like material has been used to improve electrical reliability by utilizing a buffer effect (stress absorption protection effect of an exterior sealant) due to its low elasticity. It is used as a coating and sealing agent for devices. In recent years, it has been required to improve the insulation characteristics in order to further improve the performance of these devices. In an optical device, when a filler (inorganic filler) is contained in such a material, the light transmittance is lowered, so that it is required to improve the insulating property without adding the filler. But,
The soft rubber-like elastic material or gel-like material has a low dielectric breakdown voltage and is insufficient in reliability as a protective material when the device operates at a high voltage. To that extent, some filler has been added.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to obtain a soft rubber-like or gel-like cured product which is excellent in transparency and insulating property because it does not contain a filler (inorganic filler). Optical device or semiconductor device
It is an object of the present invention to provide an addition-curable silicone composition for protective encapsulation of silicone.

[0004]

SUMMARY OF THE INVENTION The present inventors have introduced a resin-structured organopolysiloxane into an addition-curable silicone composition utilizing a hydrosilylation reaction to introduce a silicon-bonded hydrogen atom / silicon-bonded bond in the composition. It has been found that the above object can be achieved by setting the mole ratio of the alkenyl group in a specific range.

That is, the present invention provides (A) a diorganopolysiloxane containing at least two alkenyl groups bonded to a silicon atom in one molecule, (B) a SiO _4/2 unit, and Vi (R ² ) ₂ SiO. _1/2 unit and R ² ₃ SiO _1/2 unit (in the formula, Vi represents a vinyl group, R ²
Represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond. 20 to 60% by weight based on the total amount of the components (A) and (B), and (C) at least two hydrogen atoms bonded to silicon atoms in the molecule. The hydrogen atom bonded to the silicon atom in all the organohydrogenpolysiloxane in the composition contains the alkenyl group bonded to the silicon atom in the component (A) and the organohydrogenpolysiloxane contained in the component (B). An amount of 0.1 to 0.6 mol, and (D) a platinum group metal-based catalyst are contained per 1 mol of the total of vinyl groups bonded to silicon atoms, and the rubber hardness is 20.
An optical device or semiconductor device that gives the following cured product
The present invention provides an addition-curable silicone composition for protective encapsulation .

The cured product obtained by curing this composition has a rubber hardness (hereinafter referred to as JIS-A rubber hardness) of 20 or less measured by an A-type spring hardness meter specified in JIS K6301. is there. In addition, in the present invention, the silicone gel means that the rubber hardness value of JIS-A is 0 (that is, the hardness is so low that it does not show an effective rubber hardness value).
And the penetration of ASTM D-1403 (1/4 inch) is 20
It means an organopolysiloxane cured product having a low crosslinking density of 0 or less, usually 5 to 200, preferably about 10 to 150, and having fluidity under pressure (under stress).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. (A) Alkenyl group-containing diorganopolysiloxane:
The alkenyl group-containing diorganopolysiloxane of component (A) contains at least two alkenyl groups bonded to silicon atoms in one molecule and is used as the base polymer of the composition of the present invention. The alkenyl group-containing diorganopolysiloxane is generally a straight-chain one in which the main chain is basically composed of repeating diorganosiloxane units, and both ends of the molecular chain are blocked with triorganosiloxy groups. However, this may include a branched structure in a part of the molecular structure, or may be a cyclic body as a whole. Of these, linear diorganopolysiloxanes are preferable from the viewpoint of physical properties such as mechanical strength of the cured product. The alkenyl group may be present only at both ends of the molecular chain, may be present only in the middle of the molecular chain, or may be present at both ends of the molecular chain and in the middle of the molecular chain. As a typical example of such an alkenyl group-containing diorganopolysiloxane, for example, the following general formula (1):

[0008]

[Chemical 2] (In the formula, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond, X is an alkenyl group, Y is independently an alkenyl group or R ¹ , and n is Is an integer of 0 or 1 or more, m is an integer of 0 or 1 or more, and at least two alkenyl groups bonded to a silicon atom are contained in one molecule). Can be mentioned.

In the general formula (1), the unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond represented by R ¹ is, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group or a butyl group. , Isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, and other alkyl groups; cyclopentyl group, cyclohexyl group,
A cycloalkyl group such as a cycloheptyl group; a phenyl group,
An aryl group such as a tolyl group, a xylyl group, a naphthyl group and a biphenylyl group; an aralkyl group such as a benzyl group, a phenylethyl group, a phenylpropyl group and a methylbenzyl group; and at least one hydrogen atom bonded to a carbon atom of these groups. A group whose moiety is substituted with a halogen atom such as fluorine, chlorine or bromine, or a cyano group, for example, a chloromethyl group, 2-
Bromoethyl group, 3-chloropropyl group, 3,3,3-
Trifluoropropyl group, chlorophenyl group, fluorophenyl group, cyanoethyl group, 3,3,4,4,5
Examples thereof include halogen-substituted alkyl groups such as 5,6,6,6-nonafluorohexyl group, cyano-substituted alkyl groups, and halogen-substituted aryl groups. Typical R ¹ has ¹ to 10 carbon atoms, particularly 1 to 6 carbon atoms, and preferably
Methyl group, ethyl group, propyl group, chloromethyl group, bromoethyl group, 3,3,3-trifluoropropyl group,
1 to 3 unsubstituted or substituted carbon atoms such as cyanoethyl group
And an unsubstituted or substituted phenyl group such as a phenyl group, a chlorophenyl group and a fluorophenyl group.

In the general formula (1), the alkenyl group represented by X is usually 2 to 8 carbon atoms such as vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, hexenyl group and cyclohexenyl group. The lower alkenyl group having 2 to 4 carbon atoms such as vinyl group and allyl group is preferable.

In the general formula (1), Y is an alkenyl group or R ¹ , and specific examples of this alkenyl group are:
The same as those exemplified in the above X can be mentioned, and R ¹
Have the same meanings as described above, but two Y's as substituents bonded to silicon atoms at both ends of the molecular chain may be the same or different, but are preferably alkenyl groups.

In the general formula (1), n is 0 or 1 or more,
Preferably an integer from 10 to 10,000, more preferably 50 to 2,000
It is an integer of 0, and m is 0 or an integer of 1 or more, preferably an integer of 0 to 100. Also, n and m are 10 ≦ n + m ≦ 10,000
And preferably 0 ≦ m / (m + n) ≦ 0.2, particularly 50 ≦ n + m ≦ 2,000, and 0 ≦ m / (n + m) ≦
It is preferable to satisfy 0.05.

The alkenyl group-containing diorganopolysiloxane as the component (A) can be used alone or in combination of two or more, and has a viscosity at 25 ° C. of 10 to 1,
000,000 cP (centipoise), especially about 100 to 500,000 cP is preferable. (B) Organopolysiloxane having a resin structure: The organopolysiloxane having a resin structure (that is, a three-dimensional network structure) as the component (B) has the following units: SiO _4/2 units (hereinafter, may be referred to as a units). ), Vi (R ² ) ₂ SiO
_1/2 unit (hereinafter sometimes referred to as b unit) and R ² ₃
SiO _1/2 unit (hereinafter sometimes referred to as c unit), and usually has a polystyrene-equivalent weight average molecular weight of 1,00 measured by gel permeation chromatography.
Those in the range of 0 to 8,000, particularly 2,000 to 4,000 are preferable. Here, Vi represents a vinyl group, and R ² represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond. As the monovalent hydrocarbon group R ² , the same groups as those exemplified as R ¹ in the general formula (1) can be exemplified, and preferably a methyl group, a phenyl group, 3,3,3.
3-trifluoropropyl group and the like.

Each of the above units is (b unit + c unit) / a
Unit = 0.3-3, especially 0.7-1.0, and b unit / a unit = 0.
It is preferable to combine them in a molar ratio of 01 to 1, especially 0.07 to 0.2. Such an organopolysiloxane having a resin structure can be easily prepared by combining the compounds serving as the respective unit sources in the above molar ratio according to a well-known method and cohydrolyzing them in the presence of an acid, for example. Can be synthesized.

Here, as a unit source, sodium silicate,
Examples thereof include alkyl silicate, polyalkyl silicate, silicon tetrachloride and the like. The b unit source is Vi (R ² ) ₂ SiOSi (R ² ) ₂ Vi, Vi.
(R ²⁾ can be exemplified ₂ SiCl and the like. The c unit source includes (R ² ) ₃ SiOSi (R ² ) ₃ and (R ² ) ₃
SiCl etc. can be illustrated. In the above formula, Vi and R ² are as described above. The amount of vinyl groups in the resin-structured organopolysiloxane is 0.05 to 0.2 mol /
100 g is preferred.

The blending amount of the component (B) is 20 to 60% by weight, preferably 25 to 50% by weight, based on the total amount (100% by weight) of the components (A) and (B). If it is less than 20% by weight, the dielectric breakdown voltage of the cured product cannot be improved, and it is 60% by weight.
If it exceeds, the hardness of the cured product becomes too high, and the buffer effect due to low elasticity cannot be obtained. The component (B) organopolysiloxane having a resin structure may be used alone or in combination of two or more.

(C) Organohydrogenpolysiloxane: The organohydrogenpolysiloxane of component (C) has at least two hydrogen atoms (ie, SiH groups) bonded to silicon atoms in one molecule, preferably three hydrogen atoms. It is contained as described above and is used as a crosslinking agent. This organohydrogenpolysiloxane has a linear, branched,
It may have either a ring shape or a three-dimensional mesh structure. As a typical example of such an organohydrogenpolysiloxane, for example, the following average composition formula (2): H _a R ³ _b SiO 2 _{(4-ab) / 2} (2) (In the formula, R ³ is independently a fat It is an unsubstituted or substituted monovalent hydrocarbon group containing no group unsaturated bond, and a and b are 0 <
a <2, 0.7 ≦ b ≦ 2, and 0.8 ≦ a + b ≦ 3, preferably 0.001 ≦ a ≦ 1.2, 0.8 ≦ b ≦ 2, and 1 ≦ a + b ≦
The number is preferably 2.7, more preferably 0.01 ≦ a ≦ 1, 1.5 ≦ b ≦ 2 and 1.8 ≦ a + b ≦ 2.4. ) Organohydrogenpolysiloxane represented by

In the average compositional formula (2), the unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond represented by R ³ is the same as that exemplified as R ^{1 in the} above general formula (1). There are things. Typical R ³ has 1 carbon atom
To 10, especially those having 1 to 7 carbon atoms, preferably lower alkyl groups having 1 to 3 carbon atoms such as methyl group; phenyl group; and 3,3,3-trifluoropropyl group.
Examples of such an organohydrogenpolysiloxane include 1,1,3,3-tetramethyldisiloxane,
1,3,5,7-tetramethyltetracyclosiloxane, 1,3,
Siloxane oligomers such as 5,7,9-pentamethylpentacyclosiloxane; Methyl hydrogen polysiloxanes capped with trimethylsiloxy groups at both ends of the molecular chain, dimethylsiloxane / methylhydrogen siloxane copolymers, capped with trimethylsiloxy groups at both ends of the molecular chain, molecules Methyl hydrogen polysiloxane with silanol groups blocked at both chain ends,
Dimethyl siloxane / methyl hydrogen siloxane copolymer with silanol groups at both ends of the molecular chain, dimethyl polysiloxane with dimethyl hydrogen siloxy groups at both ends of the molecular chain, methyl hydrogen polysiloxane with dimethyl hydrogen siloxy groups at both ends of the molecule chain, molecular chain Dimethyl siloxane / methyl hydrogen siloxane copolymer with both ends dimethyl hydrogen siloxy groups, dimethyl siloxy / diphenyl siloxane / methyl hydrogen siloxane copolymer with both ends trimethyl siloxy groups, molecular chain Both ends dimethyl hydrogen siloxy groups dimethylsiloxane-diphenylsiloxane-methylhydrogensiloxane copolymers, made from R ₂ (H) SiO _1/2 units and SiO _4/2 units, R ₃ SiO _1/2 optionally Position, R ₂ SiO _2/2 units, R
(H) SiO _2/2 unit, (H) SiO _3/2 unit or RSi
Silicone resins that may contain O _3/2 units, provided that
R is the same as the unsubstituted or substituted monovalent hydrocarbon group exemplified as R ¹ above. ), The following general formula (3):

[0019]

[Chemical 3] (3) (In the formula, R ⁴ may be the same or different and is an unsubstituted or substituted monovalent hydrocarbon group containing no hydrogen atom or aliphatic unsaturated bond, and R ⁵ is the same or different. It may be an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond, p is a positive integer, preferably 1 to 20.
0, more preferably an integer of 2 to 100, q is 0 or a positive integer, preferably 0 to 200, more preferably 1 to 100.
Is an integer. ) Organohydrogenpolysiloxane represented by the following general formula (4):

[0020]

[Chemical 4] (4) (In the formula, R ⁶ and R ⁷ are each independently an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond,
As the unsubstituted or substituted monovalent hydrocarbon group for R ⁶ and R ⁷ ,
It can be exemplified the same as those exemplified in R ¹ in the general formula (1). R is a positive integer, preferably 2 to 200, more preferably 3 to 100, and s
Is a positive integer, preferably 1 to 200, more preferably 3 to 1
It is an integer of 00. ) Is preferable, from the viewpoint of obtaining a silicone cured product having more excellent electrical insulation when applied as a protective sealant for optical devices, semiconductor devices, etc. Is an organohydrogenpolysiloxane of the above general formula (3), more preferably the above general formula (4)
Is an organohydrogenpolysiloxane.

These organohydrogenpolysiloxanes can be produced by a known method, for example,
The following general formulas (5) and (6): R ³ SiHCl ₂ (5) R ³ ₂ SiHCl (6) (wherein R ³ is as defined in the average composition formula (2)). At least one selected chlorosilane or its alkoxy derivative (for example, methoxy derivative) is co-hydrolyzed, or the chlorosilane or its alkoxy derivative in which a chlorine atom is substituted with an alkoxy group and the following general formulas (7) and (8): R ³ ₃ SiCl (7) R ³ ₂ SiCl ₂ (8) (In the formula, R ³ is as defined in the average composition formula (2).) At least one chlorosilane selected from the group consisting of or a alkoxy thereof. It can be prepared by cohydrolyzing with a derivative (for example, a methoxy derivative).
Further, the organohydrogenpolysiloxane may be produced by subjecting the polysiloxane thus obtained by cohydrolysis to an equilibrium reaction by a known method.

The organohydrogenpolysiloxane as the component (C) can be used alone or in combination of two or more, and the viscosity at 25 ° C. is 0.2 to 1,000.
cP, particularly about 0.5 to 500 cP is preferable.

The amount of the component (C) used is 1 mol in total of the alkenyl group (particularly vinyl group) bonded to the silicon atom in the component (A) and the vinyl group bonded to the silicon atom in the component (B). The amount of hydrogen atom bonded to silicon atom (that is, SiH group) in the component (C) is usually 0.1 to 0.6 mol, preferably 0.2 to 0.6 mol, and more preferably 0.3 to 0.6 mol. If it is less than 0.1 mol, curing of the composition does not proceed, and a rubber-like elastic body or gel-like cured product cannot be obtained.If it exceeds 1 mol, the hardness of the cured product becomes too high and the buffer effect due to low elasticity is obtained. I can't get it. Further, the amount of the component (C) used is an organohydrogenpolysiloxane other than the component (C), such as an epoxy group-containing organohydrogenpolysiloxane or an alkoxy group-containing organohydrogenpolysiloxane as an adhesion improver described later. In the case of blending in the composition, for the same reason as above, the SiH groups in the whole organohydrogenpolysiloxane in the composition per 1 mol of the total of alkenyl groups in the components (A) and (B) are combined. Is used in an amount of 0.1 to 0.6 mol, preferably 0.2 to 0.6 mol, more preferably 0.3 to 0.6 mol.

(D) Platinum group metal-based catalyst: The platinum group metal-based catalyst of the component (D) comprises an alkenyl group of the component (A) and (B).
It is a catalyst for promoting the addition reaction (hydrosilylation reaction) with the SiH group of the component. As such a platinum group metal-based catalyst, a well-known catalyst for hydrosilylation reaction can be used. Specific examples thereof include platinum (including platinum black), rhodium, palladium, and other platinum group metal simple substances; H ₂
PtCl ₄ · nH ₂ O, H ₂ PtCl ₆ · nH ₂ O, NaH
PtCl ₆ · nH ₂ O, KHPtCl ₆ · nH ₂ O, Na ₂
PtCl ₆ · nH ₂ O, K ₂ PtCl ₄ · nH ₂ O, PtC
l ₄ · nH ₂ O, PtCl ₂ , Na ₂ HPtCl ₄ · nH ₂ O
(In the above formula, n is an integer of 0 to 6, and is preferably 0 or 6.) Platinum chloride, chloroplatinic acid and chloroplatinate;
Alcohol-modified chloroplatinic acid (US Pat. No. 3,220,9
72); a complex of chloroplatinic acid and an olefin (US Pat. No. 3,159,601).
No. 3,159,662, No. 3,775,4
No. 52); platinum group metals such as platinum black and palladium supported on a carrier such as alumina, silica, carbon; rhodium-olefin complex; chlorotris (triphenylphosphine) rhodium (Wilkinson catalyst); Examples thereof include complexes of platinum, chloroplatinic acid or chloroplatinate and a vinyl group-containing siloxane, particularly a vinyl group-containing cyclic siloxane. Component (D) requires an effective amount, and is usually 0.1 to 1,000 in terms of weight of platinum group metal based on the total amount of components (A) and (B).
ppm, preferably about 0.5 to 500 ppm.

Other optional ingredients: The composition of the present invention includes
In addition to the above components (A) to (D), if necessary, various additives that are usually used are added in an amount within a range that does not adversely affect the transparency of the cured product obtained from the composition of the present invention. It can be added. Examples of the additive include reinforcing inorganic fillers such as fumed silica and fumed titanium dioxide; calcium silicate, titanium dioxide, ferric oxide,
Examples include non-reinforcing inorganic fillers such as carbon black. Various other additives can be added to the composition of the present invention as long as the effects of the present invention are not impaired. In particular, when the composition is used as a one-pack type, a known curing inhibitor such as acetylene alcohol can be added. The compounding amount of the curing inhibitor is usually 10 parts by weight or less (0 to 10 parts by weight) per 100 parts by weight of the total amount of the components (A) to (D).

For the purpose of further improving the adhesiveness of the composition, an epoxy group- and / or alkoxy group-containing organohydrogenpolysiloxane compound or ester siloxane compound (that is, all monovalent groups bonded to silicon atoms are alkoxy groups) Or a hydrogen atom, that is, an organosiloxane compound containing no silicon-carbon bond in the molecule) can be added. The addition amount of these siloxane compounds is usually 10 parts by weight or less (0 to 10 parts by weight) per 100 parts by weight of the total amount of the components (A) to (D).

Preparation and Curing of the Composition: The composition of the present invention preferably comprises essentially no inorganic fillers, essentially the components (A) to (D) and optionally any other. It is prepared by mixing the ingredients. A cured product is prepared by curing the composition at room temperature or by heating. The thus obtained cured product of the present invention is a soft rubber-like elastic body or gel-like product having a rubber hardness of 20 or less according to JIS-A, and exhibits high transparency and excellent electric insulation properties.

Uses: The cured product of the present invention has the above-mentioned characteristics, and therefore, it can be used for optical devices such as LEDs, photo couplers, laser devices, and optical coupling devices, and high voltage devices requiring high transparency. Can be suitably used as a protective coating agent for a semiconductor device requiring the above, a sealant for a base or an exterior, and the like.

[0029]

EXAMPLES Examples and comparative examples of the present invention will be shown below. In each example, parts are parts by weight, viscosities are viscosities measured at 25 ° C., Me is a methyl group, and Vi is a vinyl group. [Example 1] 50 parts of dimethylpolysiloxane (VF-1) having a viscosity of 5,000 cP in which both ends of the molecular chain were blocked with vinyldimethylsiloxy groups; SiO _4/2 unit 50 mol%, (CH ₃ ).
₃ SiO _1/2 unit 42.5 mol% and Vi (CH ₃ ) ₂ SiO
50 parts of vinyl methyl polysiloxane (VMQ) having a resin structure composed of _1/2 unit of 7.5 mol%, the following average formula (9):

[0030]

[Chemical 5] 5.3 parts by weight of organohydrogenpolysiloxane represented by (9) (the amount of SiH group is 0.6 times mol per the total amount of vinyl groups in VF-1 and VMQ in VMQ), and octyl alcohol modification of chloroplatinic acid. Solution (platinum metal 1
(Wt%) 0.05 part (5 ppm in terms of platinum metal) were mixed and stirred well to prepare an addition-curable silicone composition.

With respect to this composition, hardness and / or penetration and dielectric breakdown voltage were measured according to the following measuring methods. The results are shown in Table 1. <Hardness> Measured according to the method specified in JIS C 2123, item 9. As a test piece, three 2 mm-thick sheets (thickness: about 6 mm) obtained by thermoforming the composition at 150 ° C. for 4 hours (time, the same applies below) were used.
Measured using an A-type spring hardness tester specified in S K6301. Keep the hardness tester vertical, touch the measuring needle of the test piece so that it is vertical, and read the scale immediately. <Penetration> A clean glass petri dish (30φ x 12 mm) is filled with the composition, and heat-cured at 150 ° C for 4 hours. After cooling to room temperature, the hardness is measured for penetration using a 1/4 inch micro consistency meter specified in ASTM D-1403. <Dielectric breakdown strength> The dielectric breakdown strength is JIS C 2123-1.
Measure according to the method specified in Section 7. As the test piece, a 1 mm thick sheet obtained by heat-molding the composition at 150 ° C. for 4 hours is used. The types and conditions of tests are 17.3-
Follow the method specified in (1). (1) Device a) Electrode: Diameter 2 with a rounded radius of 2.5 mm
5mm brass cylinder b) Micrometer (2) Method Commercial frequency (5) so that the crest factor is between 1.34 and 1.48.
An AC voltage of 0 Hz) is applied to the test piece. At this time, the AC voltage is increased as uniformly as possible from 0 to 1 second at a speed of about 1,000 V to obtain the breakdown voltage. (3) Divide the calculated breakdown voltage by the thickness of the measurement point to obtain the strength of dielectric breakdown per 1 mm of thickness.

Example 2 70 parts of dimethylpolysiloxane (VF-2) having a viscosity of 10,000 cP and having both ends of the molecular chain blocked with vinyldimethylsiloxy groups instead of vinyl group-containing dimethylpolysiloxane VF-1. Use 30 parts of resin structure vinylmethyl polysiloxane (VMQ)
In parts, 3.7 parts of the organohydrogenpolysiloxane of the formula (9) is used (the amount of SiH group is 0.6 times mol based on the total amount of vinyl groups in VF-2 and VMQ).
An addition-curable silicone composition was prepared in the same manner as in Example 1 except that the composition was changed to, and the hardness and / or penetration and dielectric breakdown voltage of this composition were measured. The results are shown in Table 1.

Example 3 70 parts of vinyl group-containing dimethylpolysiloxane VF-2 was used in place of vinyl group-containing dimethylpolysiloxane VF-1, and the amount of resin-structured vinylmethylpolysiloxane (VMQ) was 30 parts. Change to
The amount of the organohydrogenpolysiloxane of formula (9) was changed to 2.0 parts and the following formula (10):

[0034]

[Chemical 6] (10) The addition-curable silicone composition (the amount of SiH groups in the organohydrogenpolysiloxane mixture is the same as the above VF) in the same manner as in Example 1 except that 1.0 part of the epoxy group-containing organohydrogenpolysiloxane is added. -2
0.6 per total amount of vinyl groups in vinyl and VMQ
A double mole) was prepared and hardness and / or penetration and dielectric breakdown voltage of this composition were measured. The results are shown in Table 1.

Example 4 Instead of the organohydrogenpolysiloxane of the formula (9), the following formula (11):

[0036]

[Chemical 7] Organohydrogenpolysiloxane 13.4 represented by (11)
(The amount of SiH group is the vinyl group and VM in VF-1.
An addition-curable silicone composition was prepared in the same manner as in Example 1 except that 0.3 times mol per the total amount of vinyl groups in Q) was used, and the hardness and / or penetrability of this composition,
Also, the breakdown voltage was measured. The results are shown in Table 1.

Comparative Example 1 The amount of vinyl group-containing dimethylpolysiloxane (VF-1) was changed to 100 parts, and no vinylmethylpolysiloxane (VMQ) having a resin structure was blended.
An addition-curable silicone composition was prepared in the same manner as in Example 1 except that 3.0 parts of the organohydrogenpolysiloxane of formula (11) used in Example 4 was used instead of the organohydrogensiloxane of formula (9). The amount of SiH groups in the organohydrogenpolysiloxane of (11) is
0.6 times mol based on the amount of vinyl groups in VF-1],
The hardness and / or penetration of this composition and the dielectric breakdown voltage were measured. The results are shown in Table 1.

Comparative Example 2 The amount of vinyl group-containing dimethylpolysiloxane (VF-1) was changed to 100 parts, and no vinylmethylpolysiloxane (VMQ) having a resin structure was blended.
An addition-curable silicone composition was prepared in the same manner as in Example 1 except that 6.6 parts of the organohydrogenpolysiloxane of formula (11) used in Example 4 was used instead of the organohydrogensiloxane of formula (9). The amount of SiH groups in the organohydrogenpolysiloxane of (11) is
1.4 times mol per amount of vinyl groups in VF-1] is prepared,
The hardness and / or penetration of this composition and the dielectric breakdown voltage were measured. The results are shown in Table 1.

Comparative Example 3 The vinyl group-containing dimethylpolysiloxane used in Example 2 (viscosity 10,000 cP) (VF) instead of the vinyl group-containing dimethylpolysiloxane VF-1.
-2) 85 parts were used, the amount of vinylmethylpolysiloxane (VMQ) having a resin structure was changed to 15 parts, and the amount of organohydrogenpolysiloxane of the formula (9) was changed to 2.2 parts (SiH group content is An addition-curable silicone composition was prepared in the same manner as in Example 1, except that the total amount of vinyl groups in the VF-2 and VMQ components was 0.6 times the total amount, and the hardness and / or the penetration of the composition were measured. , And the dielectric breakdown voltage were measured. The results are shown in Table 1.

[Comparative Example 4] An addition-curable silicone composition was prepared in the same manner as in Example 1 except that the compounding amount of the organohydrogenpolysiloxane of the formula (9) was changed to 11.4 parts.
[The amount of SiH groups in the organohydrogenpolysiloxane of the formula (9) depends on the vinyl groups and VMQ in VF-1.
1.2 times mol per the total amount of vinyl groups in the mixture] was prepared, and hardness and / or penetration and dielectric breakdown voltage of this composition were measured. The results are shown in Table 1.

[0041]

[Table 1] Next, the photocoupler shown in FIG. 1 was connected as shown in FIG. 2, and the compositions of Examples 1 to 4 and Comparative Examples 1 to 4 were mixed with each other as shown in FIG.
It was used as the silicone sealant 5 of No. 3, and the withstand voltage was evaluated by simultaneous mounting comparison. Specifically, an AC voltage (50H) is applied between the anode 6 and collector 9 of the photocoupler terminal.
z) was applied for 1 second, and the withstand voltage was evaluated by determining the proportion of the sample in which the resin was destroyed when each voltage was applied. The results are shown in Table 2.

[0042]

[Table 2] (Note) The numerical value (%) indicates the non-defective rate in 100 measurement samples.

[0043]

EFFECTS OF THE INVENTION The addition-curable silicone composition of the present invention is a soft rubber-like or gel-like highly transparent material which has a significantly improved insulating property, particularly a dielectric breakdown voltage, when cured by adding a filler without adding a filler. A cured product having a sex property is obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a photocoupler used in an example.

FIG. 2 is a connection diagram of the photocoupler of FIG.

[Explanation of symbols]

1. Light-emitting element 2 Photo detector 3 Epoxy transfer mold resin 4 Lead frame 5 Silicone sealant 6 ... Anode 7 ... Cathode 8 Emitter 9: Collector

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H01L 23/02 H01L 23/02 Z // C09D 183/05 C09D 183/05 183/07 183/07 (56) Reference 55-118959 (JP, A) JP-A-7-41679 (JP, A) JP-A-7-53872 (JP, A) JP-A-10-231428 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) C08L 83/00-83/16 C08K 3/00-13/08

Claims (4)

(57) [Claims] 1. A diorganopolysiloxane containing (A) at least two alkenyl groups bonded to a silicon atom in one molecule, (B) a SiO _4/2 unit, and a Vi (R ² ) ₂ SiO _1/2 unit. And R ² ₃ SiO _1/2 unit (wherein Vi represents a vinyl group, R ^{2 3}
Represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond. 20 to 60% by weight based on the total amount of the components (A) and (B), and (C) at least two hydrogen atoms bonded to silicon atoms in the molecule. The hydrogen atom bonded to the silicon atom in all the organohydrogenpolysiloxane in the composition contains the alkenyl group bonded to the silicon atom in the component (A) and the organohydrogenpolysiloxane contained in the component (B). An amount of 0.1 to 0.6 mol per 1 mol of the total of vinyl groups bonded to silicon atoms, and (D) a platinum group metal catalyst are contained, and the rubber hardness is 20.
An optical device or semiconductor device that gives the following cured product
Addition-curable silicone composition for protective encapsulation . 2. An organohydrogenpolysiloxane as the component (C) has the following general formula (4): (4) (In the formula, R ⁶ and R ⁷ are each independently an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond, r is an integer of 2 to 200, and s is 1 It is an integer of ~ 200.)
In being indicated, shea recone composition of claim 1. Wherein the inorganic filler contains no, shea recone composition according to claim 1 or 2. 4. A cured product having a rubber hardness of 20 or less, which is obtained by curing the silicone composition according to any one of claims 1 to 3 .