Thermally conductive silicone rubber sheet comprising a thermally conductive adhesive layer

Patent metadata

Field	Value
Publication number	US-2022127500-A1
Application number	US-202017428316-A
Country	US
Kind code	A1
Filing date	Feb 4, 2020
Priority date	Feb 7, 2019
Publication date	Apr 28, 2022
Grant date	—

Abstract

One of the purposes of the present invention is to provide a composite heat-release sheet which is excellent in thermal conductivity and electrical insulation property and, at the same time, has all of sufficient adhesion to an actual machine, low thermal resistance, reworkability, and reliable adhesive strength. Another purpose is to provide a more convenient production process for the heat-release sheet. A thermally conductive silicone rubber sheet comprising at least one thermally conductive silicone rubber layer having a type A durometer hardness of 60 to 96 and at least one silicone adhesive layer, wherein the silicone adhesive layer is a cured product of an addition curable or peroxide curable silicone adhesive composition comprising (a) organopolysiloxane having at least one alkenyl group bonded to a silicon atom and having a phenyl group bonded to a silicon atom in such an amount that the percentage of the number of the phenyl group is 2 to 20%, based on the total number of substituents each bonded to a silicon atom, (c) thermally conductive filler having an average particle diameter of less than 10 μm and containing 0 to 3 mass % of particles having a particle diameter of 20 μm or more and 0 to 0.01 mass % of particles having a particle diameter of 40 μm or more, and (f) silicone resin comprising an R3SiO1/2 unit and an SiO4/2 unit.

First claim

1 . A thermally conductive silicone rubber sheet comprising at least one thermally conductive silicone rubber layer having a type A durometer hardness of 60 to 96 and at least one silicone adhesive layer, wherein
the silicone adhesive layer is a cured product of an addition curable or peroxide curable silicone adhesive composition comprising the following components (a), (c) and (f): 100 parts by mass of (a) organopolysiloxane having at least one alkenyl group bonded to a silicon atom and having a phenyl group bonded to a silicon atom in such an amount that the percentage of the number of the phenyl group is 2 to 20%, based on the total number of substituents each bonded to a silicon atom, 100 to 800 parts by mass of (c) thermally conductive filler having an average particle diameter of less than 10 μm and containing 0 to 3 mass % of particles having a particle diameter of 20 μm or more and 0 to 0.01 mass % of particles having a particle diameter of 40 μm or more, and 50 to 300 parts by mass of (f) silicone resin comprising an R 3 SiO 1/2 unit and an SiO 4/2 unit, wherein R is an unsubstituted or substituted monovalent hydrocarbon group having from 1 to 10 carbon atoms and no aliphatic unsaturated bond, and a ratio of the number of the R 3 SiO 1/2 unit to the number of the SiO 4/2 unit is 0.5 to 2.5.

2 . The thermally conductive silicone rubber sheet according to claim 1 , wherein the silicone adhesive composition is addition curable and further comprises the following components (b), (d) and (e):
(b) organohydrogenpolysiloxane in such an amount that a ratio of the number of the hydrogen atom bonded to a silicon atom in component (b) to the number of the alkenyl group in component (a) is 0.5 to 30, a catalytic amount of (d) addition reaction catalyst, 0.01 to 1 part by mass of (e) addition reaction controlling agent.

3 . The thermally conductive silicone rubber sheet according to claim 1 , wherein the silicone adhesive composition is peroxide curable and further comprises 0.01 to 10 parts by mass of (g) organic peroxide, relative to 100 parts by mass of component (a).

4 . The thermally conductive silicone rubber sheet according to claim 1 , wherein the thermally conductive filler is at least one selected from alumina, aluminum hydroxide, aluminum nitride, boron nitride, zinc oxide and metal aluminum.

5 . The thermally conductive silicone rubber sheet according to claim 1 , wherein the thermally conductive silicone rubber layer has an adhesive strength of 0.01 N/25 m or less and the silicone adhesive layer is layered on one surface of the thermally conductive silicone rubber layer.

6 . The thermally conductive silicone rubber sheet according to claim 1 , wherein the silicone adhesive layer has a thickness of 2 to 40 μm.

7 . The thermally conductive silicone rubber sheet according to claim 1 , wherein the thermally conductive silicone rubber layer has a thickness of 50 to 900 μm.

8 . The thermally conductive silicone rubber sheet according to claim 1 , wherein the thermally conductive silicone rubber layer is a cured product of an addition curable, thermally conductive silicone rubber composition comprising an alkenyl group-containing organopolysiloxane, an organohydrogenpolysiloxane, an addition reaction catalyst, a thermally conductive filler, and a surface treatment agent.

9 . The thermally conductive silicone rubber sheet according to claim 1 , wherein the thermally conductive silicone rubber layer is a cured product of a peroxide curable, thermally conductive silicone rubber composition comprising an alkenyl group-containing organopolysiloxane, an organic peroxide, a thermally conductive filler, and a surface treatment agent.

10 . The thermally conductive silicone rubber sheet according to claim 1 , wherein the thermally conductive silicone rubber layer has a thermal conductivity of 1.0 W/m·K or larger.

11 . The thermally conductive silicone rubber sheet according to claim 1 , being in a form of roll, wherein a protective sheet is provided on the surface of the silicone adhesive layer which surface is not in contact with the thermally conductive silicone rubber layer.

12 . A method for preparing the thermally conductive silicone rubber sheet according to claim 1 , wherein the method comprises steps of applying the silicone adhesive composition on at least one surface of the thermally conductive silicone rubber layer and heat-curing the silicone adhesive composition to obtain the thermally conductive silicone rubber sheet.

13 . The thermally conductive silicone rubber sheet according to claim 2 , wherein the thermally conductive filler is at least one selected from alumina, aluminum hydroxide, aluminum nitride, boron nitride, zinc oxide and metal aluminum.

14 . The thermally conductive silicone rubber sheet according to claim 3 , wherein the thermally conductive filler is at least one selected from alumina, aluminum hydroxide, aluminum nitride, boron nitride, zinc oxide and metal aluminum.

15 . The thermally conductive silicone rubber sheet according to claim 2 , wherein the thermally conductive silicone rubber layer has an adhesive strength of 0.01 N/25 m or less and the silicone adhesive layer is layered on one surface of the thermally conductive silicone rubber layer.

16 . The thermally conductive silicone rubber sheet according to claim 3 , wherein the thermally conductive silicone rubber layer has an adhesive strength of 0.01 N/25 m or less and the silicone adhesive layer is layered on one surface of the thermally conductive silicone rubber layer.

17 . The thermally conductive silicone rubber sheet according to claim 4 , wherein the thermally conductive silicone rubber layer has an adhesive strength of 0.01 N/25 m or less and the silicone adhesive layer is layered on one surface of the thermally conductive silicone rubber layer.

18 . The thermally conductive silicone rubber sheet according to claim 2 , wherein the silicone adhesive layer has a thickness of 2 to 40 μm.

19 . The thermally conductive silicone rubber sheet according to claim 3 , wherein the silicone adhesive layer has a thickness of 2 to 40 μm.

20 . The thermally conductive silicone rubber sheet according to claim 4 , wherein the silicone adhesive layer has a thickness of 2 to 40 μm.

Assignees

• Shinetsu Chemical Co

Inventors

• Ito Takanori
• Endo Akihiro

Classifications

• H10W40/251

  Organics · CPC title

• Y10T428/2848

  Three or more layers · CPC title

• Y10T428/2852

  Adhesive compositions · CPC title

• C09J11/04 Primary

  inorganic · CPC title

• C09J2483/006

  in the substrate · CPC title