US 12,441,923 B2
Branched polysiloxanes and methods for their preparation and use as heat transfer fluids
Yang Cheng, Midland, MI (US); Xiaoyuan Zhou, Midland, MI (US); Eric Joffre, Midland, MI (US); Mike Ferritto, Midland, MI (US); Nanguo Liu, Midland, MI (US); Christoph Lang, Schindellegi (CH); and John Cuthbert, Midland, MI (US)
Assigned to Dow Global Technologies LLC, Midland, MI (US); and Dow Silicones Corporation, Midland, MI (US)
Appl. No. 17/755,240
Filed by Dow Silicones Corporation, Midland, MI (US); and Dow Global Technologies LLC, Midland, MI (US)
PCT Filed Jan. 4, 2021, PCT No. PCT/US2021/012026
§ 371(c)(1), (2) Date Apr. 25, 2022,
PCT Pub. No. WO2021/141836, PCT Pub. Date Jul. 15, 2021.
Claims priority of provisional application 62/958,889, filed on Jan. 9, 2020.
Prior Publication US 2023/0002660 A1, Jan. 5, 2023
Int. Cl. C09K 5/10 (2006.01)
CPC C09K 5/10 (2013.01) 9 Claims
 
1. A method comprising operating a system at a temperature of 25° C. to 500° C. using a heat transfer fluid comprising a branched polysiloxane compound comprising a moiety of formula: (TM2)x, where T represents a unit of formula (RSiO3/2) and M represents a unit of formula (R3SiO1/2), each R is an independently selected monovalent hydrocarbon group of 1 to 6 carbon atoms, and subscript x≥3, and wherein the branched polysiloxane compound comprises a species selected from the group consisting of:

OG Complex Work Unit Chemistry
Tm(TM2)n, where subscript m>1, subscript n>3, and n/m is 1 to 1.5, and
a combination of two or more of T(TM2)3, Q(TM2)4, and Tm(TM2)n, where operating the system comprises heating the heat transfer fluid at a temperature of 300° C. to 500° C.