# US 5,708,100 A · Epoxy-based stoving enamels comprising carboxyl-functional alkylidenepolyphenols > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,708,100 A - Document ID: US5708100A - Status: Granted - Kind: A - Application number: 08/650,773 - Filed: 1996-05-20 - Granted: 1998-01-13 - Earliest claimed: 1995-05-22 - Assignees: Vianova Resins GmbH - Inventors: Thomas Burkhart; Wolfgang Hesse; Paul Oberressl - Web page: https://patentgrep.com/patent/US5708100A ## CPC - C08L 61/06: of aldehydes with phenols - C08G 59/625: {Hydroxyacids} - C09D 161/06: of aldehydes with phenols - C09D 163/00: Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins - C08L 63/00: Compositions of epoxy resins; Compositions of derivatives of epoxy resins - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - 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) ## Abstract Stoving enamels comprising epoxy resins and carboxyl-functional alkylidenepolyphenols in a quantity such that the carboxyl groups are present at least in equimolar quantities relative to the epoxide groups of the epoxy resins are suitable for coating the inside of metallic food containers and give, on the packaging, baked coating films which are essentially free from migratable constituents carrying epoxide groups. ## Claims ### Claim 1 A stoving enamel consisting essentially of one or more epoxy resins containing more than one epoxide group per molecule and one or more carboxyl-functional novolaks which are reaction products of a novolak and one or more acids selected from the group consisting of olefinically unsaturated mono- and dicarboxylic acids, anhydrides of the mono- and dicarboxyclic acids, and haloalkanoic acids, in a quantity such that the carboxyl groups are present in at least an equimolar quantity relative to the epoxide groups of the epoxy resins, and the enamel optionally comprising a natural-resin acid. ### Claim 2 (depends on 1) A stoving enamel as claimed in claim 1, wherein the carboxyl-functional novolak comprise a reaction product of one or more novolaks with one or more halocarboxylic acids. ### Claim 3 (depends on 1) A stoving enamel as claimed in claim 1, wherein the carboxyl-functional novolak comprise a reaction product of one or more novolaks with one or more olefinically unsaturated dicarboxylic acids or their anhydrides. ### Claim 4 (depends on 1) A stoving enamel as claimed in claim 1, wherein the carboxyl-functional novolak comprise a reaction product of one or more novolaks, one or more natural-resin acids, and one or more olefinically unsaturated dicarboxylic acids or their anhydrides. ### Claim 5 (depends on 1) A process for the preparation of a stoving enamel as claimed in claim 1, comprising mixing the epoxy resin and carboxyl-functional novolak and then adding an acid catalyst to the mixture. ### Claim 6 (depends on 5) A process as claimed in claim 5, wherein the weight ratio of epoxy resin to carboxyl-functional novolak is from 8.5:1 to 1:4. ### Claim 7 (depends on 5) A process as claimed in claim 5, wherein the acid catalyst comprises phosphoric acid. ### Claim 8 (depends on 1) A method of using the stoving enamel as claimed in claim 1, which comprises coating a food container with the stoving enamel. ### Claim 9 (depends on 1) A method of using the stoving enamel as claimed in claim 1, which comprises coating the inside surface of a metal container with the stoving enamel. ### Claim 10 (depends on 1) A method of using the stoving enamel as claimed in claim 1, Which comprises forming a baked coating film on packaging, which is essentially free from migratable constituents carrying epoxide groups, wherein the coating film comprises the stoving enamel. ### Claim 11 (depends on 2) A stoving enamel as claimed in claim 2, wherein the halocarboxylic acid comprises chloroacetic acid. ### Claim 12 (depends on 3) A stoving enamel as claimed in claim 3, wherein the olefinically unsaturated dicarboxylic and/or anhydride comprises fumaric acid, maleic acid, or maleic acid anhydride. ### Claim 13 (depends on 1) A stoving enamel as claimed in claim 1; wherein the ratio of the novolak to the weight of the carboxylic acid components is (100-x):x, wherein x.ltoreq.40. ### Claim 14 (depends on 13) A stoving enamel as claimed in claim 13, wherein x is from 10 to 20. ### Claim 15 (depends on 1) A stoving enamel as claimed in claim 1, wherein the carboxyl-functionality is provided by fumaric acid, maleic acid, or maleic acid anhydride. ### Claim 16 (depends on 1) A stoving enamel as claimed in claim 1, which further comprises rosin as the natural-resin acid. ### Claim 17 (depends on 1) A product formed by curing the stoving enamel of claim 1. ### Claim 18 (depends on 1) A stoving enamel as claimed in claim 1, wherein the epoxy resin has an epoxide equivalent weight of 100 to 2000 g/mol. ### Claim 19 (depends on 1) A stoving enamel as claimed in claim 1, wherein there is from 1.1 to 10 mol of carboxylic group in the carboxy-functional novolak per mol of epoxide groups in the epoxy resin. ### Claim 20 (depends on 17) A product of claim 17, which is free from migratable constituents carrying epoxy groups.