# US 2013/0153262 A1 · Polyester imide resin based varnish for low-permittivity coating film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153262 A1 - Document ID: US20130153262A1 - Status: Published application - Kind: A1 - Application number: 13/818,924 - Filed: 2011-08-23 - Published: 2013-06-20 - Earliest claimed: 2010-08-24 - Assignees: Sumitomo Electric Industries, Ltd. - Inventors: Hideaki Saito; Yuudai Furuya; Kengo Yoshida; Yuji Hatanaka - Web page: https://patentgrep.com/patent/US20130153262A1 ## CPC - H01B 3/306: {Polyimides or polyesterimides} - C08G 18/4661: {containing three nitrogen atoms in the ring} - C08G 73/16: Polyester-imides - C09D 179/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors - H01B 3/308: {Wires with resins} - H01B 3/36: condensation products of phenols with aldehydes or ketones - C08L 75/06: from polyesters - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - 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) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract Provided are a varnish mainly containing a polyester imide and capable of forming a low-permittivity insulating layer, as well as an insulated electronic wire achieving low permittivity by using the varnish. The varnish mainly contains a polyester imide resin obtained by reacting a carboxylic acid including a dicarboxylic acid, or an anhydride or alkyl ester thereof (carboxylic acid or derivative thereof), an alcohol, and a diamine compound with one another. In the varnish, adjustment is made such that a molar ratio (OH/COOH) of hydroxyl groups of the alcohol to carboxyl groups of the carboxylic acid or derivative thereof becomes 1.9 or less or such that a content of highly polarized imide groups per unit amount of polyester imide chain is reduced by increasing molecular weights of the raw material monomers. ## Claims ### Claim 1 A polyester imide resin based varnish for a low-permittivity coating film, mainly comprising a polyester imide resin obtained by reacting a carboxylic acid or derivative thereof that is a carboxylic acid including a dicarboxylic acid, or an anhydride or alkyl ester thereof; an alcohol; and a diamine compound with one another, wherein monomer composition is adjusted such that a total molecular weight of said diamine compound and said dicarboxylic acid becomes 368 or more, or a molar ratio (OH/COOH) of a hydroxyl group of said alcohol to a carboxyl group of said carboxylic acid or derivative thereof becomes 1.9 or less. ### Claim 2 (depends on 1) The polyester imide resin based varnish for the low-permittivity coating film according to claim 1, wherein said carboxylic acid or derivative thereof includes a dicarboxylic acid having a molecular weight of 167 or more, or an anhydride or alkyl ester thereof. ### Claim 3 (depends on 1) The polyester imide resin based varnish for the low-permittivity coating film according to claim 1, wherein said diamine compound includes a diamine compound having a molecular weight of 250 or more. ### Claim 4 (depends on 1) The polyester imide resin based varnish for the low-permittivity coating film according to claim 1, wherein said carboxylic acid or derivative thereof includes a dicarboxylic acid having a molecular weight of 167 or more, or an anhydride or alkyl ester thereof, and said diamine compound includes a diamine compound having a molecular weight of 250 or more. ### Claim 5 (depends on 2) The polyester imide resin based varnish for the low-permittivity coating film according to claim 2, wherein said dicarboxylic acid is naphthalenedicarboxylic acid or cyclohexanedicarboxylic acid. ### Claim 6 (depends on 3) The polyester imide resin based varnish for the low-permittivity coating film according to claim 3, wherein said diamine compound is a diamine compound containing no fluorine atom. ### Claim 7 (depends on 1) The polyester imide resin based varnish for the low-permittivity coating film according to claim 1, wherein a molar ratio (OH/COOH) of a hydroxyl group of said alcohol to a carboxyl group of said carboxylic acid or derivative thereof is 1.2 to 2.7. ### Claim 8 (depends on 1) The polyester imide resin based varnish for the low-permittivity coating film according to claim 1, wherein a ratio (imide/ester) of a content of an imide acid portion to a content of an ester portion is 0.2 to 1.0. ### Claim 9 A polyester imide resin based varnish for a low-permittivity coating film, mainly comprising a polyester imide resin obtained by reacting a carboxylic acid or derivative thereof that is a carboxylic acid including a dicarboxylic acid, or an anhydride or alkyl ester thereof; an alcohol; and a diamine compound with one another, wherein monomer composition is adjusted such that a molar ratio (OH/COOH) of a hydroxyl group of said alcohol to a carboxyl group of said carboxylic acid or derivative thereof becomes 1.9 or less. ### Claim 10 (depends on 9) The polyester imide resin based varnish for the low-permittivity coating film according to claim 9, wherein a ratio (imide/ester) of a content of an imide acid portion to a content of an ester portion is 0.32 or more. ### Claim 11 (depends on 9) The polyester imide resin based varnish for the low-permittivity coating film according to claim 9, wherein said alcohol is a mixed alcohol containing ethylene glycol (EG) and tris(2-hydroxyethyl)isocyanurate (THEIC) at a ratio of THIEC/EG=0.5 to 4.0. ### Claim 12 (depends on 1) The polyester imide resin based varnish for the low-permittivity coating film according to claim 1, further comprising a phenol resin or analog thereof. ### Claim 13 (depends on 1) An insulated electric wire comprising an insulating coating film obtained by applying the varnish recited in claim 1 onto a conductor and baking the varnish. ### Claim 14 (depends on 4) The polyester imide resin based varnish for the low-permittivity coating film according to claim 4, wherein said dicarboxylic acid is naphthalenedicarboxylic acid or cyclohexanedicarboxylic acid. ### Claim 15 (depends on 4) The polyester imide resin based varnish for the low-permittivity coating film according to claim 4, wherein said diamine compound is a diamine compound containing no fluorine atom. ### Claim 16 (depends on 10) The polyester imide resin based varnish for the low-permittivity coating film according to claim 10, wherein said alcohol is a mixed alcohol containing ethylene glycol (EG) and tris(2-hydroxyethyl)isocyanurate (THEIC) at a ratio of THIEC/EG=0.5 to 4.0. ### Claim 17 (depends on 11) The polyester imide resin based varnish for the low-permittivity coating film according to claim 11, further comprising a phenol resin or analog thereof. ### Claim 18 (depends on 11) An insulated electric wire comprising an insulating coating film obtained by applying the varnish recited in claim 11 onto a conductor and baking the varnish.