# US 12,767,872 B2 · Thermally conductive silicone composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,767,872 B2 - Document ID: US12767872B2 - Status: Granted - Kind: B2 - Application number: 18/566,121 - Filed: 2021-08-19 - Published: 2024-08-22 - Granted: 2026-10-20 - Earliest claimed: 2021-08-19 - Assignees: Dow Silicones Corporation - Applicants: Dow Silicones Corporation - Inventors: Yan Zheng; Dorab Bhagwagar; Qianqing Ge; Peng Wei; Han Guang Wu - Web page: https://patentgrep.com/patent/US12767872B2 ## CPC - C09K 5/14: Solid materials, e.g. powdery or granular - C08G 77/12: containing silicon bound to hydrogen - C08G 77/20: containing silicon bound to unsaturated aliphatic groups - C08K 13/06: Pretreated ingredients and ingredients covered by the main groups C08K3/00 - C08K7/00 - H05K 7/2039: {characterised by the heat transfer by conduction from the heat generating element to a dissipating body (arrangements for increasing/decreasing heat-transfer, e.g. fins details, F28F13/00)} - C08K 2003/2296: {of zinc} - C08K 2003/282: {Binary compounds of nitrogen with aluminium} - C08K 7/18: inorganic - C08K 9/08: Ingredients agglomerated by treatment with a binding agent - C08K 2201/001: Conductive additives - C08K 2201/005: Additives being defined by their particle size in general - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract A composition contains: (A) a curable silicone composition including: (a1) a vinyldimethylsiloxy-terminated polydimethylpolysiloxane having a viscosity in a range of 30-400 milliPascal*seconds, (a2) a silicon-hydride functional crosslinker, and (a3) a hydrosilylation catalyst, where the molar ratio of silicon-hydride functionality from the crosslinker to vinyl functionality is in a range of 0.5:1 to 1:1; (B) a filler treating agent comprising one or both of an alkyl trialkoxysilane and a mono-trialkoxysiloxy terminated dimethylpolysiloxane; and (C) a thermally conductive filler mixture including (c1) 40-55 wt % of aluminum nitride fillers, containing a blend of: (c1-a) 15-41 wt % of spherical aluminum nitride particles having a D50 particle size of 100 micrometers or more, and (c1-b) spherical or irregular shaped aluminum nitride particles having a D50 particle size of 20-80 micrometers; (c2) spherical aluminum oxide particles having a D50 particle size of 1-5 micrometers; and (c3) 10-20 wt % of irregular zinc oxide particles having a D50 particle size of 0.1-0.5 micrometer; where the total amount of the thermally conductive filler mixture is 94-97 wt %; and where wt % values are relative to the weight of the thermally conductive composition unless otherwise stated. ## Claims ### Claim 1 A thermally conductive composition comprising: (A) a curable silicone composition comprising: (a1) a vinyldimethylsiloxy-terminated polydimethylpolysiloxane having a viscosity in a range of 30 to 400 milliPascal*seconds, (a2) a silicon-hydride functional crosslinker, and (a3) a hydrosilylation catalyst, where the molar ratio of silicon-hydride functionality from the crosslinker to vinyl functionality is in a range of 0.5:1 to 1:1; (B) a filler treating agent comprising one or both of an alkyl trialkoxysilane and a mono-trialkoxysiloxy terminated dimethylpolysiloxane; and (C) a thermally conductive filler mixture comprising, based on the weight of the thermally conductive composition, (c1) from 40 weight-percent to 55 weight-percent of aluminum nitride fillers, comprising a blend of: (c1-a) from 15 weight-percent to 41 weight-percent of spherical aluminum nitride particles having a D50 particle size of 100 micrometers or more, and (c1-b) spherical or irregular shaped aluminum nitride particles having a D50 particle size of from 20 to 80 micrometers; (c2) spherical aluminum oxide particles having a D50 particle size of from 1 to 5 micrometers; and (c3) from 10 weight-percent to 20 weight-percent of irregular zinc oxide particles having a D50 particle size of from 0.1 to 0.5 micrometer; where the total amount of the thermally conductive filler mixture is from 94 weight-percent to 97 weight-percent, based on the weight of the thermally conductive composition. ### Claim 2 (depends on 1) The thermally conductive composition of claim 1, wherein the spherical or irregular shaped aluminum nitride particles (c1-b) with a D50 particle size of from 20 to 80 micrometers are present at a concentration of from 10 weight-percent to 39 weight-percent, based on the weight of the thermally conductive composition. ### Claim 3 (depends on 1) The thermally conductive composition of claim 1, wherein spherical aluminum nitride particles in the blend are at a total concentration of greater than 60 weight-percent to 100 weight-percent, based on the total weight of the blend of the aluminum nitride particles (c1-a) and (c1-b). ### Claim 4 (depends on 1) The thermally conductive composition of claim 1, wherein the thermally conductive filler mixture (C) comprises from zero to less than 1 weight-percent of boron nitride fillers, based on the weight of the thermally conductive composition. ### Claim 5 (depends on 1) The thermally conductive composition of claim 1, wherein the spherical aluminum nitride particles (c1-a) have a D50 particle size of 120 micrometers or more. ### Claim 6 (depends on 1) The thermally conductive composition of claim 1, wherein the spherical aluminum nitride particles (c1-a) with a D50 particle size of 100 micrometers or more are present at a concentration of from 30 weight-percent to 38 weight-percent, based on the weight of the thermally conductive composition. ### Claim 7 (depends on 1) The thermally conductive composition of claim 1, wherein the aluminum nitride fillers (c1) are present at a concentration of from 45 weight-percent to 55 weight-percent, based on the weight of the thermally conductive composition. ### Claim 8 (depends on 1) The thermally conductive composition of claim 1, wherein the silicon-hydride functional crosslinker comprises one or more polysiloxane having chemical structures selected from (II), (III) or combinations thereof: where subscript x has a value in a range of 10 to 100, subscript y has a value in a range of 3 to 30, and subscript z has a value in a range of 3 to 100. ### Claim 9 (depends on 1) The thermally conductive composition of claim 1, wherein the alkyl trialkoxysilane is selected from C6 to C12 alkyl trimethoxysilanes and the mono-trialkoxysiloxy terminated dimethylpolysiloxane has an average chemical structure (IV): where subscript a has a value in a range of from 20 to 150 and R′ is a C1 to C12 alkyl group. ### Claim 10 (depends on 1) An article comprising the thermally conductive composition of claim 1 on another material. ### Claim 11 (depends on 10) The article of claim 10, wherein the thermally conductive composition is between and in thermal contact with a heat generating component of an electronic device and one or more than one of a heat sink, cooling plate and metal cover for the electronic device.