Thermally conductive polysiloxane composition

1. A thermally conductive polysiloxane composition comprising:

(A) a thermally conductive filler;

(B) a siloxane compound represented by the following general formula (1):

wherein:

R 1 is a group having one of the following structures:

R 2 is a group having a siloxane unit represented by the following general formula (2):

wherein each R 4 is a methyl group, Y is a methyl group or a vinyl group, and d is an integer of 10 to 200;

each X is independently —CH 2 CH 2 — or —CH 2 CH(CH 3 )—;

each of a and b is independently an integer of 1 or more;

c is an integer of 1 or more;

a+b+c is an integer of 4; and

each R 3 is a methyl group;

(C) an alkoxysilane compound represented by the following general formula (3):

R 11 e R 12 f Si(OR 13 ) 4−(e+f)   (3)

wherein R 11 is an alkyl group having 6 to 14 carbon atoms, R 12 is an unsubstituted or substituted acyclic monovalent hydrocarbon group having 1 to 5 carbon atoms, or an unsubstituted or substituted aryl group, each R 13 is independently an alkyl group having 1 or 2 carbon atoms, e is an integer of 1, f is an integer of 0 or 1, and e+f is an integer of 1 or 2;

(D) a polyorganosiloxane containing at least one aliphatic unsaturated group per molecule;

(E) a polyorganohydrogensiloxane having two or more hydrogen atoms bonded to silicon atoms per molecule; and

(F) a platinum-based catalyst,

wherein a blending amount of component (B) is in a range of from 0.2 to 10 parts by mass, relative to 100 parts by mass of component (A),

wherein a blending amount of component (C) is in a range of from 0.1 to 5 parts by mass, relative to 100 parts by mass of component (A), and

wherein the blending ratio of the component (B) and the component (C), in terms of a mass ratio, is in a range of from 80:20 to 70:30.

2. The thermally conductive polysiloxane composition according to claim 1 , wherein the component (A) comprises 20 to 70% by mass of (A-1) inorganic particles having an average particle diameter of 30 to 150 μm, 1 to 50% by mass of (A-2) inorganic particles having an average particle diameter of 1 to less than 30 μm, and 1 to 50% by mass of (A-3) inorganic particles having an average particle diameter of 0.1 to less than 1 μm.

3. The thermally conductive polysiloxane composition according to claim 1 , further comprising (G) fumed silica chemically treated with a silazane compound, wherein the blending amount of the component (G) is 0.1 to 10 parts by mass, relative to 100 parts by mass of the component (D).

4. A silicone rubber which is obtained by curing the thermally conductive polysiloxane composition according to claim 1 .

5. An electronic part comprising the silicone rubber according to claim 4 .

6. The thermally conductive polysiloxane composition according to claim 2 , further comprising (G) fumed silica chemically treated with a silazane compound, wherein the blending amount of the component (G) is 0.1 to 10 parts by mass, relative to 100 parts by mass of the component (D).

7. A silicone rubber which is obtained by curing the thermally conductive polysiloxane composition according to claim 2 .

8. An electronic part comprising the silicone rubber according to claim 7 .

9. A silicone rubber which is obtained by curing the thermally conductive polysiloxane composition according to claim 3 .

10. An electronic part comprising the silicone rubber according to claim 9 .

11. The thermally conductive polysiloxane composition according to claim 1 , wherein the blending amount of component (B) is in a range of from 1.54 to 10 parts by mass, relative to 100 parts by mass of component (A), and

wherein the blending amount of component (C) is in a range of from 0.44 to 5 parts by mass, relative to 100 parts by mass of component (A).

12. The thermally conductive polysiloxane composition according to claim 1 , wherein the blending amount of component (C) is in a range of from 0.44 to 0.66 parts by mass, relative to 100 parts by mass of component (A).

13. The thermally conductive polysiloxane composition according to claim 1 , wherein the blending amount of component (B) is in a range of from 1.54 to 1.76 parts by mass, relative to 100 parts by mass of component (A).

14. The thermally conductive polysiloxane composition according to claim 1 , wherein the blending amount of component (B) is in a range of from 1.54 to 1.76 parts by mass, relative to 100 parts by mass of component (A), and

wherein the blending amount of component (C) is in a range of from 0.44 to 0.66 parts by mass, relative to 100 parts by mass of component (A).

15. The thermally conductive polysiloxane composition according to claim 1 , wherein in the general formula (1), R 1 is a group having one of the following structures:

wherein in the general formula (1), Y is a methyl group, and d is an integer of 10 to 70; and

wherein in the general formula (3), R 11 is an alkyl group having 6 to 10 carbon atoms, and f is an integer of 0.

16. The thermally conductive polysiloxane composition according to claim 1 , wherein in the general formula (1), R 1 is a group having one of the following structures:

—COO(CH 3 ) 3 Si(OCH 3 ) 3 ,

—Si(OCH 3 ) 3 .

17. The thermally conductive polysiloxane composition according to claim 1 , wherein the component (B) is

and the component (C) is n-Hexyltrimethoxysilane or n-Decyltriethoxysilane.