# US 10,370,495 B2 · Polyamic acid resin, polyamideimide film, and method for preparing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,370,495 B2 - Document ID: US10370495B2 - Status: Granted - Kind: B2 - Application number: 15/668,964 - Filed: 2017-08-04 - Published: 2018-02-15 - Granted: 2019-08-06 - Earliest claimed: 2016-08-11 - Assignees: SK Innovation Co., Ltd. - Applicants: SK Innovation Co., Ltd. - Inventors: Sang Yoon Park; Hyeon Jeong Kim; Tae Sug Jang; Jin Hyung Park - Web page: https://patentgrep.com/patent/US10370495B2 ## CPC - C08G 73/14: Polyamide-imides - C08G 73/1021: {characterised by the catalyst used} - C08G 73/1039: {comprising halogen-containing substituents} - C08G 73/1042: {Copolyimides derived from at least two different tetracarboxylic compounds or two different diamino compounds} - C08G 73/1078: {wholly aromatic in the diamino moiety} - C08J 5/18: Manufacture of films or sheets - C09D 179/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors - C08J 2379/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - 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) - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) ## Abstract Provided are a polyamic acid resin, a polyamideimide film, and a method for preparing the same. More specifically, provided are a polyamic acid resin derived from a combination of specific components, a polyamideimide film capable of implementing high modulus and excellent optical properties while implementing excellent mechanical properties, heat properties, and electrical properties, and a method for preparing the same. ## Claims ### Claim 1 A polyamideimide film comprising: a polyamideimide resin derived from an aromatic diamine including: 2,2′-bis(trifluoromethyl)benzidine; a cycloaliphatic dianhydride; and an aromatic diacid dichloride consisting of isophthaloyl dichloride (IPC) and terephthaloyl dichloride (TPC). ### Claim 2 (depends on 1) The polyamideimide film of claim 1, wherein the cycloaliphatic dianhydride is cyclobutane tetracarboxylic dianhydride. ### Claim 3 (depends on 1) The polyamideimide film of claim 1, wherein a content of the aromatic diacid dichloride ranges from 40 moles to 90 moles based on 100 moles of the aromatic diamine. ### Claim 4 (depends on 1) The polyamideimide film of claim 1, wherein the polyamideimide film has a light transmittance, measured at 550 nm, of 88% or more, and a Yellow index of 3.0 or less. ### Claim 5 (depends on 4) The polyamideimide film of claim 4, wherein the polyamideimide film has a modulus of 5.0 GPa or more, measured at an extension rate of 25 mm/min using UTM 3365 manufactured by Instron. ### Claim 6 (depends on 1) The polyamideimide film of claim 1, wherein the polyamideimide film has a light transmittance, measured at 550 nm, of 88% or more, and a Yellow index of 3.0 or less, based on a thickness of 45 to 55 μm. ### Claim 7 (depends on 6) The polyamideimide film of claim 6, wherein the polyamideimide film has a modulus of 5.0 GPa or more, measured at an extension rate of 25 mm/min using UTM 3365 manufactured by Instron, on a specimen having a thickness of 45 to 55 μm, a length of 50 mm, and a width of 10 mm. ### Claim 8 A method for preparing a polyamideimide film comprising: (a) preparing a polyamic acid solution by dissolving aromatic diamine containing 2,2′-bis(trifluoromethyl)benzidine in an organic solvent, and adding and reacting cycloaliphatic dianhydride and an aromatic diacid dichloride consisting of isophthaloyl dichloride (IPC) and terephthaloyl dichloride (TPC); (b) preparing polyamideimide resin by imidization of the polyamic acid solution; and (c) applying a polyamideimide solution in which the polyamideimide resin is dissolved in the organic solvent. ### Claim 9 (depends on 8) The method of claim 8, wherein the cycloaliphatic dianhydride is cyclobutane tetracarboxylic dianhydride. ### Claim 10 (depends on 8) The method of claim 8, wherein in step (b), the polyamic acid solution further includes any one or two or more selected from an imidization catalyst and a dehydrating agent. ### Claim 11 (depends on 8) The method of claim 8, wherein the polyamic acid solution in step (a) has a solid content of 3 to 20 wt %. ### Claim 12 A polyamic acid resin derived from aromatic diamine including 2,2′-bis(trifluoromethyl)benzidine, a cycloaliphatic dianhydride, and an aromatic diacid dichloride consisting of isophthaloyl dichloride (IPC) and terephthaloyl dichloride (TPC). ### Claim 13 (depends on 1) The polyamideimide film of claim 1, wherein a molar ratio between the isophthaloyl dichloride (IPC) and the terephthaloyl dichloride (TPC) ranges from 0.3 to 4.0. ### Claim 14 (depends on 8) The method of claim 8, wherein a molar ratio between the isophthaloyl dichloride (IPC) and the terephthaloyl dichloride (TPC) ranges from 0.3 to 4.0. ### Claim 15 (depends on 12) The polyamic acid resin of claim 12, wherein a molar ratio between the isophthaloyl dichloride (IPC) and the terephthaloyl dichloride (TPC) ranges from 0.3 to 4.0.