# US 10,864,709 B2 · Heat conductive sheet and method for producing heat conductive sheet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,864,709 B2 - Document ID: US10864709B2 - Status: Granted - Kind: B2 - Application number: 15/117,580 - Filed: 2015-02-13 - Published: 2016-12-08 - Granted: 2020-12-15 - Earliest claimed: 2014-03-31 - Assignees: Dexerials Corporation - Applicants: Dexerials Corporation - Inventors: Masayuki Matsushima - Web page: https://patentgrep.com/patent/US10864709B2 ## CPC - B32B 27/30: comprising vinyl {(co)polymers; comprising acrylic (co)polymers} - B32B 7/06: permitting easy separation - B32B 7/12: using interposed adhesives or interposed materials with bonding properties - B32B 27/08: of synthetic resin - B32B 27/16: specially treated, e.g. irradiated - B32B 27/20: using fillers, pigments, thixotroping agents - B32B 27/302: {comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers} - B32B 27/306: {comprising vinyl acetate or vinyl alcohol (co)polymers} - B32B 27/308: {comprising acrylic (co)polymers} - H10W 40/251: {Organics} - B32B 2264/102: Oxide or hydroxide - B32B 2264/105: Metal - B32B 2270/00: Resin or rubber layer containing a blend of at least two different polymers - B32B 2274/00: Thermoplastic elastomer material - B32B 2305/72: Cured, e.g. vulcanised, cross-linked - B32B 2307/302: Conductive - B32B 2307/50: having particular mechanical properties - B32B 2307/54: Yield strength; Tensile strength - B32B 2307/748: Releasability - B32B 2457/00: Electrical equipment - H10W 40/255: {having a laminate or multilayered structure, e.g. direct bond copper [DBC] ceramic substrates} - H10W 40/70: Fillings or auxiliary members in containers or in encapsulations for thermal protection or control - H10W 70/02: of conductive package substrates serving as an interconnection, e.g. of metal plates (manufacture or treatment of leadframes H10W70/04) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A heat conductive sheet having excellent adhesion between an acrylic resin layer and a supporting sheet is provided. The heat conductive sheet includes a heat conductive resin layer including a heat conductive acrylic resin composition; and a supporting resin layer (supporting sheet) containing a polyvinyl acetal resin and a styrene-vinyl isoprene block copolymer. Crosslinking of the supporting sheet with acrylic monomers of the acrylic heat conductive resin layer enables improvements in adhesion between the heat conductive resin layer and the supporting sheet. ## Claims ### Claim 1 A heat conductive sheet comprising: a heat conductive resin layer comprising a heat conductive acrylic resin composition; and a supporting resin layer containing a polyvinyl acetal resin and a styrene-vinyl isoprene block copolymer, wherein: the polyvinyl acetal resin and the styrene-vinyl isoprene block copolymer are blended at a mass ratio from 9:1 to 7:3, and a degree of acetalization of the polyvinyl acetal resin is in a range of from 50 to 90 mol % wherein the heat conductive resin layer overlays with the supporting resin layer along a thickness direction of the heat conductive sheet, and at least a portion of an edge of the heat conductive resin layer is in contact with at least a portion of an edge of the supporting resin layer. ### Claim 2 (depends on 1) The heat conductive sheet according to claim 1, wherein the polyvinyl acetal resin is polyvinyl acetal or polyvinyl butyral. ### Claim 3 (depends on 2) The heat conductive sheet according to claim 2, wherein the polyvinyl acetal resin has a molecular weight from 5×104 to 20×104. ### Claim 4 (depends on 2) The heat conductive sheet according to claim 2, wherein the polyvinyl acetal resin has a glass transition temperature from 50 to 150° C. ### Claim 5 (depends on 2) The heat conductive sheet according to claim 2, wherein the styrene-vinyl isoprene block copolymer has a glass transition temperature from −40 to +40° C. ### Claim 6 (depends on 1) The heat conductive sheet according to claim 1, wherein the polyvinyl acetal resin has a molecular weight from 5×104 to 20×104. ### Claim 7 (depends on 6) The heat conductive sheet according to claim 6, wherein the polyvinyl acetal resin has a glass transition temperature from 50 to 150° C. ### Claim 8 (depends on 6) The heat conductive sheet according to claim 6, wherein the styrene-vinyl isoprene block copolymer has a glass transition temperature from −40 to +40° C. ### Claim 9 (depends on 1) The heat conductive sheet according to claim 1, wherein the polyvinyl acetal resin has a glass transition temperature from 50 to 150° C. ### Claim 10 (depends on 9) The heat conductive sheet according to claim 9, wherein the styrene-vinyl isoprene block copolymer has a glass transition temperature from −40 to +40° C. ### Claim 11 (depends on 1) The heat conductive sheet according to claim 1, wherein the styrene-vinyl isoprene block copolymer has a glass transition temperature from −40 to +40° C. ### Claim 12 (depends on 1) The heat conductive sheet according to claim 1, wherein the styrene-vinyl isoprene block copolymer has a styrene content from 10% to 30%. ### Claim 13 (depends on 12) The heat conductive sheet according to claim 12, wherein the polyvinyl acetal resin and the styrene-vinyl isoprene block copolymer are blended at a mass ratio from 8.5:1.5 to 8:2. ### Claim 14 A method for manufacturing a heat conductive sheet comprising the steps of: forming a supporting resin layer by mixing and sheet-forming a polyvinyl acetal resin and a styrene-vinyl isoprene block copolymer; and forming a heat conductive resin layer by curing a heat conductive acrylic resin composition in a state of contact with the supporting resin layer, wherein: the polyvinyl acetal resin and the styrene-vinyl isoprene block copolymer are blended at a mass ratio from 9:1 to 7:3, and a degree of acetalization of the polyvinyl acetal resin is in a range of from 50 to 90 mol % wherein the heat conductive resin layer overlays with the supporting resin layer along a thickness direction of the heat conductive sheet, and at least a portion of an edge of the heat conductive resin layer is in contact with at least a portion of an edge of the supporting resin layer.