# US 2023/0054528 A1 · Mold-release film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0054528 A1 - Document ID: US20230054528A1 - Status: Published application - Kind: A1 - Application number: 17/792,114 - Filed: 2020-06-29 - Published: 2023-02-23 - Earliest claimed: 2020-04-27 - Assignees: Kobayashi & Co., Ltd. - Applicants: Kobayashi & Co.,Ltd. - Inventors: Keisuke SAKAI; Nanae TANAKA - Web page: https://patentgrep.com/patent/US20230054528A1 ## CPC - B29C 33/68: Release sheets - B29C 37/0075: {using release sheets} - B29C 41/003: {characterised by the choice of material} - B29C 41/46: Heating or cooling - B32B 27/08: of synthetic resin - B32B 27/26: using curing agents - B32B 27/322: {comprising halogenated polyolefins, e.g. PTFE} - C08J 5/18: Manufacture of films or sheets - C08J 7/0427: {with only one layer of a composition containing a polymer binder (with more layers C08J7/042)} - H10W 74/01: Manufacture or treatment - B29K 2027/18: PTFE, i.e. polytetrafluoroethylene {, e.g. ePTFE, i.e. expanded polytetrafluoroethylene} - B32B 2264/0221: Thermoplastic elastomer particles - B32B 2307/5825: Tear resistant - B32B 2307/748: Releasability - C08J 2327/18: Homopolymers or copolymers of tetrafluoroethylene - C08J 2367/02: Polyesters derived from dicarboxylic acids and dihydroxy compounds; (C08J2367/06 takes precedence) - C08J 2427/18: Homopolymers or copolymers of tetrafluoroethylene - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS ## Abstract The objective of the present invention is to provide a mold-release film that docs not contaminate the mold or the formed body. This invention provides a mold-release film comprising a base material layer formed from a thermoplastic resin, and a surface layer formed from a resin composition layered on at least one surface of the base material layer. The mold-release film has a trouser tear strength, conforming to JIS K 7128-1, of 5 N/mm or stronger. The resin composition has a peel strength of 15 mN/30 mm or weaker, as measured at 175° C. in accordance with JIS Z0237. The resin composition has an elongation at break of 70% or greater, as measured at 175° C. in accordance with JIS K 7127. ## Claims ### Claim 1 A release film having a base layer formed of a thermoplastic resin and a surface layer formed of a resin composition laminated on at least one surface of the base layer, wherein the trouser tear strength in accordance with JIS K7128-1 is 5 N/mm or more, the peeling force of the resin composition is 15 mN/30 mm or less when measured at 175° C. according to JIS Z0237, and the breaking point elongation of the resin composition is 70% or more when measured at 175° C. according to JIS K7127. ### Claim 2 (depends on 1) The release film according to claim 1, wherein the resin composition is a fluororesin. ### Claim 3 (depends on 1) The release film according to claim 1, wherein the resin composition contains an isocyanate curing agent. ### Claim 4 (depends on 1) The release film according to claim 1, wherein the resin composition contains a tetrafluoroethylene resin. ### Claim 5 (depends on 1) The release film according to claim 1, which is used in sealing of a semiconductor to be flip-chip connected. ### Claim 6 (depends on 1) The release film according to claim 1, which is used for molding two or more times. ### Claim 7 (depends on 2) The release film according to claim 2, wherein the resin composition contains an isocyanate curing agent. ### Claim 8 (depends on 2) The release film according to claim 2, wherein the resin composition contains a tetrafluoroethylene resin. ### Claim 9 (depends on 3) The release film according to claim 3, wherein the resin composition contains a tetrafluoroethylene resin. ### Claim 10 (depends on 2) The release film according to claim 2, which is used in sealing of a semiconductor to be flip-chip connected. ### Claim 11 (depends on 3) The release film according to claim 3, which is used in sealing of a semiconductor to be flip-chip connected. ### Claim 12 (depends on 4) The release film according to claim 4, which is used in sealing of a semiconductor to be flip-chip connected. ### Claim 13 (depends on 2) The release film according to claim 2, which is used for molding two or more times. ### Claim 14 (depends on 3) The release film according to claim 3, which is used for molding two or more times. ### Claim 15 (depends on 4) The release film according to claim 4, which is used for molding two or more times. ### Claim 16 (depends on 5) The release film according to claim 5, which is used for molding two or more times.