US-12624267-B2 - Thermal conductive silicone composition

Abstract

A thermal conductive silicone composition includes (A) 100 parts by mass of an organopolysiloxane having a kinematic viscosity at 25° C. of 10 to 500,000 mm 2 /s; (B) 10 to 2,000 parts by mass of a thermal conductive filler having an average particle size of 0.01 to 100 μm; and (C) 1,000 to 10,000 parts by mass of gallium or a gallium alloy having a melting point of −20 to 100° C. The resulting thermal conductive silicone composition has excellent thermal conduction property.

Inventors

• Kunihiro Yamada

Assignees

• SHIN-ETSU CHEMICAL CO., LTD.

Dates

Publication Date

20260512

Application Date

20210329

Priority Date

20200417

Claims (4)

1. 1 . A thermal conductive silicone composition comprising the following components (A) to (C): (A) 100 parts by mass of an organopolysiloxane having a kinematic viscosity at 25° C. of 10 to 500,000 mm 2 /s, wherein the organopolysiloxane comprises an organopolysiloxane having a hydrolysable group represented by the following general formula (2) and a linear organopolysiloxane represented by the following formula (3): wherein R 2 represents an alkyl group having a carbon number of 1 to 6, R 3 each independently represents an unsubstituted or substituted monovalent hydrocarbon group having a carbon number of 1 to 18 without containing an alkenyl group, and b is 5 to 120, wherein R 1 does not comprise an alkenyl group, and each independently represents an unsubstituted or substituted monovalent hydrocarbon group having a carbon number of 1 to 18, and m is a number with which the organopolysiloxane has a kinematic viscosity at 25° C. of 10 to 500,000 mm 2 /s, wherein the component (A) comprises the hydrolysable group-containing organopolysiloxane represented by the general formula (2) in an amount of 30 to 90% by mass relative to the total mass of the component (A); (B) 10 to 2,000 parts by mass of a thermal conductive filler having an average particle size of 0.01 to 100 μm; and (C) 1,000 to 10,000 parts by mass of gallium or a gallium alloy having a melting point of −20 to 100° C.
2. 2 . The thermal conductive silicone composition according to claim 1 , wherein the component (B) is one or more selected from a zinc oxide powder, an alumina powder, a boron nitride powder, an aluminum nitride powder, an aluminum hydroxide powder, and a magnesium oxide powder.
3. 3 . The thermal conductive silicone composition according to claim 1 , wherein the gallium alloy of the component C is one or more selected from a Ga—In alloy, a Ga—Sn—Zn alloy, a Ga—In—Sn alloy, and a Ga—In—Bi—Sn alloy.
4. 4 . The thermal conductive silicone composition according to claim 2 , wherein the gallium alloy of the component (C) is one or more selected from a Ga—In alloy, a Ga—Sn—Zn alloy, a Ga—In—Sn alloy, and a Ga—In—Bi—Sn alloy.

Description

TECHNICAL FIELD The present invention relates to a thermal conductive silicone composition having excellent thermal conduction property. BACKGROUND ART For example, a heat dissipating body such as a heat sink has been widely used in many of heat-generating electronic parts such as CPU for preventing damages, performance deterioration, or the like due to temperature raise during use. For efficiently conducting heat generated by the heat-generating electronic part to the heat dissipating body, thermal conductive material is generally used between the heat-generating electronic part and the heat dissipating body. Heat-dissipating sheets and heat-dissipating grease are generally known as the thermal conductive material. The heat-dissipating sheets can be easily mounted, but a void occurs in an interface with the heat-generating electronic part or the heat dissipating body, thereby the interfacial thermal resistance increases, and the thermal conductive performance becomes insufficient. On the contrary, the heat-dissipating grease is close to liquid in its property, so that the interfacial thermal resistance can be reduced by adhering to both the heat-generating electronic part and the heat dissipating body without being affected by unevenness of the surfaces thereof. However, sufficient heat-dissipating performance cannot be obtained. For example, Patent Documents 1 to 5 propose, as a component for imparting thermal conduction property, materials incorporating a low melting point metal, a metal filler, or the like. However, due to further increases in amount of heat generation accompanying high integration and speeding up of the heat-generating electronic parts in recent years, these thermal conductive materials cannot provide sufficient thermal conduction effect. CITATION LIST Patent Literature Patent Document 1: JP 2003-176414 APatent Document 2: JP 2005-112961 APatent Document 3: JP 2003-218296 APatent Document 4: JP 2004-039829 APatent Document 5: JP 2007-106809 A SUMMARY OF INVENTION Technical Problem The present invention has for its object to address such problems, and to provide a thermal conductive silicone composition having excellent thermal conduction property. Solution to Problem To solve the above problem, the present invention provides a thermal conductive silicone composition comprising the following components (A) to (C): (A) 100 parts by mass of an organopolysiloxane having a kinematic viscosity at 25° C. of 10 to 500,000 mm2/s;(B) 10 to 2,000 parts by mass of a thermal conductive filler having an average particle size of 0.01 to 100 μm; and(C) 1,000 to 10,000 parts by mass of gallium or a gallium alloy having a melting point of −20 to 100° C. Such a thermal conductive silicone composition has excellent thermal conduction property. Additionally, in the present invention, the thermal conductive silicone composition preferably comprises the component (A) which does not comprise an alkenyl group. Such a thermal conductive silicone composition has excellent thermal resistance. Moreover, in the present invention, the thermal conductive silicone composition preferably comprises one or more selected from a zinc oxide powder, an alumina powder, a boron nitride powder, an aluminum nitride powder, an aluminum hydroxide powder, and a magnesium oxide powder as the component (B). Such a thermal conductive silicone composition may have further improved thermal conduction property. Furthermore, in the present invention, the thermal conductive silicone composition preferably comprises, as the component (A), an organopolysiloxane represented by the following average composition formula (1), R1aSiO(4-a)/2  (1) wherein R1 each independently represents an unsubstituted or substituted monovalent hydrocarbon group having a carbon number of 1 to 18 without containing an alkenyl group, and 1.8≤a≤2.2. Such a thermal conductive silicone composition may have preferable flowability. Furthermore, in the present invention, the thermal conductive silicone composition preferably comprises, as the component (A), a hydrolysable group-containing organopolysiloxane represented by the following general formula (2) in an amount of 10 to 100% by mass relative to the total mass of the component (A), wherein R2 represents an alkyl group having a carbon number of 1 to 6, R3 each independently represents an unsubstituted or substituted monovalent hydrocarbon group having a carbon number of 1 to 18 without containing an alkenyl group, and “b” represents an integer of 5 to 120. In such thermal conductive silicone composition, the silicone composition may be highly filled with a powder. Furthermore, in the present invention, the thermal conductive silicone composition preferably comprises, as the gallium alloy of the component (C), one or more selected from a Ga—In alloy, a Ga—Sn—Zn alloy, a Ga—In—Sn alloy, and a Ga—In—Bi—Sn alloy. Such a thermal conductive silicone composition may have excellent workability in a process of preparing th