# US 2014/0154407 A1 · Polyamide-imide resin insulating coating material, insulated wire and method of making the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0154407 A1 - Document ID: US20140154407A1 - Status: Published application - Kind: A1 - Application number: 14/173,208 - Filed: 2014-02-05 - Published: 2014-06-05 - Earliest claimed: 2005-04-25 - Assignees: Hitachi Metals, Ltd. - Applicants: Hitachi Metals, Ltd. - Inventors: Hideyuki KIKUCHI; Yuzo YUKIMORI - Web page: https://patentgrep.com/patent/US20140154407A1 ## CPC - H01B 3/306: {Polyimides or polyesterimides} - B05D 7/20: to wires (for insulating electric cables H01B13/16) - H01B 3/305: {Polyamides or polyesteramides} - Y10T 428/2927: including structurally defined particulate matter - Y10T 428/2933: Coated or with bond, impregnation or core - Y10T 428/2938: Coating on discrete and individual rods, strands or filaments - 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}) - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A polyamide-imide resin insulating coating material, which is obtained by reacting an isocyanate component with an acid component, has a main solvent component of γ-butyrolactone. In the coating material, a total compounding ratio of 4,4′-diphenylmethane diisocyanate (MDI) and trimellitic anhydride (TMA) is 85 to 98 mol %, where the total compounding ratio is given by averaging a compounding ratio of MDI to the isocyanate component and a compounding ration of TMA to the acid component. ## Claims ### Claim 1 A polyamide-imide resin insulating coating material, comprising: a polyamide-imide resin obtained by reacting, in a mixed solvent, an isocyanate component comprising (i) 4,4′-diphenylmethane diisocyanate and (ii) an isomer of 4,4′-diphenylmethane diisocyanate other than 4,4′-diphenylmethane diisocyanate, with an acid component comprising a trimellitic anhydride, wherein: a total compounding ratio, obtained by averaging the compounding ratio of the 4,4′-diphenylmethane diisocyanate in the isocyanate components and the compounding ratio of the trimellitic anhydride in the acid components, is in the range of 85 to 98 mol %; and the mixed solvent comprises ybutyrolactone as a main solvent and at least one nitrogen-containing high boiling point polar solvent selected from the group consisting of N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide (DMAC). ### Claim 2 A method of making a polyamide-imide resin insulating coating material, comprising: reacting an isocyanate component comprising (i) 4,4′-diphenylmethane diisocyanate and (ii) an isomer of 4,4′-diphenylmethane diisocyanate other than 4,4′-diphenylmethane diisocyanate, with an acid component comprising a trimellitic anhydride by using a mixed solvent comprising γ-butyrolactone as a main solvent and at least one nitrogen-containing high boiling point polar solvent selected from the group consisting of N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide (DMAC) to synthesize the polyamide-imide resin insulating coating material, wherein a total compounding ratio, obtained by averaging the compounding ratio of the 4,4′-diphenylmethane diisocyanate in the isocyanate components and the compounding ratio of the trimellitic anhydride in the acid components, is in the range of 85 to 98 mol %. ### Claim 3 (depends on 2) The method according to claim 2, wherein: the acid component comprises 80 mol % or more of trimellitic anhydride and 20 mol % or less of a tetracarboxylic dianhydride. ### Claim 4 (depends on 3) The method according to claim 3, wherein: the acid component comprises 80 mol % or more of trimellitic anhydride and 20 mol % or less of tricarboxylic acid. ### Claim 5 A method of making an insulated wire, comprising: preparing a polyamide-imide resin insulating coating material by reacting an isocyanate component comprising (i) 4,4′-diphenylmethane diisocyanate and (ii) an isomer of 4,4′-diphenylrnethane diisocyanate other than 4,4′-diphenylrnethane diisocyanate, with an acid component comprising a trimellitic anhydride by using a mixed solvent comprising γ-butyrolactone as a main solvent and at least one nitrogen-containing high boiling point polar solvent selected from the group consisting of N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide (DMAC) to synthesize the polyamide-imide resin insulating coating material, wherein a total compounding ratio, obtained by averaging the compounding ratio of the 4,4′-diphenylmethane diisocyanate in the isocyanate components and the compounding ratio of the trimellitic anhydride in the acid components, is in the range of 85 to 98 mol %; and coating the polyamide-imide resin insulating coating material on a conductor, and then baking the polyamide-imide resin insulating coating material to form a coating film on the conductor. ### Claim 6 A method of making an insulated wire, comprising: preparing a polyamide-imide resin insulating coating material by reacting an isocyanate component comprising (i) 4,4′-diphenylmethane diisocyanate and (ii) an isomer of 4,4′-diphenylmethane diisocyanate other than 4J4′-diphenylmethane diisocyanate, with an acid component comprising a trimellitic anhydride by using a mixed solvent comprising γ-butyrolactone as a main solvent and at least one nitrogen-containing high boiling point polar solvent selected from the group consisting of N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide (DMAC) to synthesize the polyamide-imide resin insulating coating material, wherein a total compounding ratio defined by averaging the compounding ratio of the 4,4′-diphenylmethane diisocyanate in the isocyanate components and trimellitic anhydride in the acid components is in the range of 85 to 98 mol %, where the compounding ratio is given by averaging a compounding ratio of the MDI to the isocyanate component and a compounding ratio of the TMA to the acid component; forming an organic insulation coating layer on the surface of a conductor, and coating the polyamide-imide resin insulating coating material on the organic insulation coating layer, and then baking the polyamide-imide resin insulating coating material to form a coating film on the organic insulation coating layer. ### Claim 7 (depends on 1) The polyamide-imide resin insulating coating material according to claim 1, wherein: the compounding ratio of the trimellitic anhydride to the acid component is 80 to 98 mol %. ### Claim 8 (depends on 1) The polyamide-imide resin insulating coating material according to claim 1, wherein: the compounding ratio of the trimellitic anhydride to the acid component is 80 to 100 mol %. ### Claim 9 (depends on 1) The polyamide-imide resin insulating coating material according to claim 1, wherein: the acid component further comprises an acid other than the trimellitic anhydride, the acid other than the trimellitic anhydride is an aromatic tetracarboxylic dianhydride selected from 3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride, and 4,4′-oxydiphthalic dianhydride; an alicyclic tetracarboxylic dianhydride selected from butanetetracarboxylic dianhydride and 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylicanhydride; or a tricarboxylic acid selected from trimesic acid and tris-(2-carboxyethyl)isocyanurate. ### Claim 10 (depends on 2) The method according to claim 2, wherein: the acid component further comprises an acid other than the trimellitic anhydride, the acid other than the trimellitic anhydride is an aromatic tetracarboxylic dianhydride selected from 3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride, and 4,4′-oxydiphthalic dianhydride; an alicyclic tetracarboxylic dianhydride selected from butanetetracarboxylic dianhydride and 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylicanhydride; or a tricarboxylic acid selected from trimesic acid and tris-(2-carboxyethyl)isocyanurate. ### Claim 11 (depends on 5) The method according to claim 5, wherein: the acid component further comprises an acid other than the trimellitic anhydride, the acid other than the trimellitic anhydride is an aromatic tetracarboxylic dianhydride selected from 3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride, and 4,4′-oxydiphthalic dianhydride; an alicyclic tetracarboxylic dianhydride selected from butanetetracarboxylic dianhydride and 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylicanhydride; or a tricarboxylic acid selected from trimesic acid and tris-(2-carboxyethyl)isocyanurate. ### Claim 12 (depends on 6) The method according to claim 6, wherein: the acid component further comprises an acid other than the trimellitic anhydride, the acid other than the trimellitic anhydride is an aromatic tetracarboxylic dianhydride selected from 3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride 3,3′,4,4′-benzophenone tetracarboxylic dianhydride, and 4,4′-oxydiphthalic dianhydride; an alicyclic tetracarboxylic dianhydride selected from butanetetracarboxylic dianhydride and 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylicanhydride; or a tricarboxylic acid selected from trimesic acid and tris-(2-carboxyethyl)isocyanurate.