Silicone composition
AssigneeShin-Etsu Chemical Co., Ltd.
InventorMitsuhiro IWATA
Life of this patent
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Abstract
Provided is a silicone composition which has a thermal conductivity of 4.0 W/m·K or more but less than 7.0 W/m·K when measured by the hot disk method according to ISO 22007-2, and has a viscosity at 25° C. of 5-800 Pa·s when measured with a spiral viscometer at a rotation speed of 10 rpm. The silicone composition maintains fluidity and has good handling properties and excellent heat dissipation performance, even when highly filled with a thermally conductive filler to impart excellent insulation properties and thermal conductivity thereto. Further, the silicone composition has excellent durability and reliability under high temperature or high temperature and high humidity conditions.
Claims7
A silicone composition, comprising:
- (A) an organopolysiloxane having a kinematic viscosity of 10 to 10,000 mm2/s at 25° C., the organopolysiloxane being represented by general formula (1) below:
- 50 to 100 parts by mass,
- wherein each R1 independently represents an unsubstituted or substituted monovalent hydrocarbon group, each R2 independently represents an alkyl group, an alkoxyalkyl group, an alkenyl group or an acyl group, a represents an integer of 5 to 100 and b represents an integer of 1 to 3;
- (B) an organopolysiloxane having a kinematic viscosity of 10 to 100,000 mm2/s at 25° C., the organopolysiloxane being represented by average composition formula (2) below:
- 0 to 50 parts by mass,
- (note that a total amount of the components (A) and (B) is 100 parts by mass)
- wherein each R3 independently represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms and c represents a number of 1.8 to 2.2;
- (C) an α-aluminum oxide powder having a hexagonal close-packed crystal structure consisting of a polyhedron having 8 or more faces, the α-aluminum oxide powder having a particle shape having a D/H ratio of 0.3 or more and 30 or less, where D represents a maximum particle diameter parallel to a hexagonal lattice face of the hexagonal close-packed lattice and H represents a particle diameter perpendicular to the hexagonal lattice face, the α-aluminum oxide powder having an average particle size of 7 to 30 μm, a proportion of coarse particles of 50 μm or more in a laser diffraction particle size distribution being 1% by mass or less relative to the total amount of the component (C), the α-aluminum oxide powder having a purity of 990 or more;
- and
- (D) a zinc oxide powder having an average particle size of 0.01 μm or more and less than 3 μm, a proportion of coarse particles of 10 μm or more in a laser diffraction particle size distribution being 1% by mass or less relative to the total amount of the component (D),
- (note that a ratio between the components (C) and (D) is 5:5 to 9.5:0.5 by mass, and a total content of (C) and (D) is 75% to 85% by volume)
- the silicone composition having a thermal conductivity of 4.0 W/m-K or more and less than 7.0 W/m·K, as measured by a hot disk method in accordance with ISO 22007-2, the silicone composition having a viscosity of 5 to 800 Pa-s at 25° C., as measured with a spiral viscometer at a rotation speed of 10 rpm.
Dependencies are inferred from the claim text.