US 11,746,236 B2
Shear thinning thermally conductive silicone compositions
Erica A. Frankel, Collegeville, PA (US); Andrés E. Becerra, Auburn, MI (US); Andrew J. Swartz, Collegeville, PA (US); and Darren Hansen, Auburn, MI (US)
Assigned to DOW GLOBAL TECHNOLOGIES LLC, Midland, MI (US); DOW SILICONES CORPORATION, Midland, MI (US); and ROHM AND HAAS COMPANY, Collegeville, PA (US)
Appl. No. 17/787,455
Filed by Dow Global Technologies LLC, Midland, MI (US); Dow Silicones Corporation, Midland, MI (US); and Rohm and Haas Company, Collegeville, PA (US)
PCT Filed Feb. 11, 2021, PCT No. PCT/US2021/017529
§ 371(c)(1), (2) Date Jun. 20, 2022,
PCT Pub. No. WO2021/178119, PCT Pub. Date Sep. 10, 2021.
Claims priority of provisional application 62/985,491, filed on Mar. 5, 2020.
Prior Publication US 2023/0032719 A1, Feb. 2, 2023
Int. Cl. C08L 83/04 (2006.01); C08J 3/22 (2006.01)
CPC C08L 83/04 (2013.01) [C08J 3/226 (2013.01); C08J 2383/04 (2013.01)] 10 Claims
 
1. A composition comprising the following components:
(a) 15 to 49.8 volume-percent of a first polysiloxane that has a viscosity in a range of 50 centiStokes to 550 Stokes as determined according to ASTM D4283-98;
(b) 0.2 to 5 volume-percent of an organoclay;
(c) 50-74 volume-percent roundish or crushed thermally conductive fillers comprising:
(i) 5 to 15 volume-percent small thermally conductive fillers having a median particle size in a range of 0.1 to 1.0 micrometers;
(ii) 10 to 25 volume-percent medium thermally conductive fillers having a median particle size in a range of 1.1 to 5.0 micrometers;
(iii) 25 to 50 volume-percent large thermally conductive fillers having a median particle size in a range of 5.1 to 50 micrometers; and
(d) 0 to 5 volume-percent of an alkoxy functional linear polysiloxane different from the first polysiloxane and/or an alkoxy functional linear silane;
where volume-percent values are relative to composition volume.