# US 5,707,729 A · Adhesive for copper foils and adhesive-backed copper foil > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,707,729 A - Document ID: US5707729A - Status: Granted - Kind: A - Application number: 08/524,802 - Filed: 1995-09-07 - Granted: 1998-01-13 - Earliest claimed: 1994-09-13 - Assignees: Mitsui Mining & Smelting Co., Ltd. - Inventors: Tetsuro Satoh - Web page: https://patentgrep.com/patent/US5707729A ## CPC - H05K 3/386: {by the use of an organic polymeric bonding layer, e.g. adhesive} - C09J 163/00: Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins - C08L 2666/04: Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof - C08L 2666/08: Homopolymers or copolymers according to C08L7/00 - C08L21/00; Derivatives thereof - H05K 3/022: {Processes for manufacturing precursors of printed circuits, i.e. copper-clad substrates} - H05K 2201/0133: Elastomeric or compliant polymer - H05K 2201/0355: Metal foils - H05K 2201/0358: Resin coated copper [RCC] - Y10S 428/921: Fire or flameproofing - Y10T 428/2804: Next to metal - Y10T 428/287: including epoxy group or epoxy polymer - Y10T 428/2883: including addition polymer of diene monomer [e.g., SBR, SIS, etc.] - Y10T 428/31511: Of epoxy ether - Y10T 428/31529: Next to metal - Y10T 428/31551: Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.] - Y10T 428/31681: Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.] - Y10T 428/31696: Including polyene monomers [e.g., butadiene, etc.] - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An adhesive composition and foils coated with the adhesive, wherein the adhesive consisting essentially of: (I) a fist amount of a non-modified epoxy resin and a second amount of a rubber-modified epoxy resin in a total amount of 60-100 parts by weight, wherein the amount of rubber-modified epoxy resin is 0.5 to 20 parts by weight; (II) 5-30 parts by weight of a polyvinyl acetal resin; and optionally contains (III) at least one resin selected rom the group consisting of blocked isocyanate resins, polyester resins, polyester resins, melamine resins and urethane resins. The adhesive coating can optionally contain inorganic fillers, fire retardants, and curing agents. ## Claims ### Claim 1 An adhesive for copper foils, said adhesive consisting essentially of: (I) a first amount of a non-modified epoxy resin and a second amount of a rubber-modified epoxy resin in a total amount of 60-100 parts by weight, wherein said second amount of said rubber-modified epoxy resin is 0.5 to 20 parts by weight; (II) 5-30 parts by weight of a polyvinyl acetal resin; and optionally, (III) at least one resin selected rom the group consisting of blocked isocyanate resins, polyester resins, polyester resins, melamine resins and urethane resins. ### Claim 2 (depends on 1) An adhesive for copper foils according to claim 1 wherein the adhesive contains at least one resin selected from the group consisting of blocked isocyanate resins, polyester resins, polyester resins, melamine resins and urethane resins. ### Claim 3 (depends on 1) An adhesive for copper foils according to claim 1, wherein said rubber is a member selected from the group consisting of a butadiene rubber having a terminal carboxyl group, an acrylonitrile-butadiene copolymer, and an isoprene rubber. ### Claim 4 (depends on 1) An adhesive for copper foils according to claim 1, wherein said epoxy resin is a member selected from the group consisting of a bisphenol A epoxy resin, a bisphenol F epoxy resin, a novolak epoxy resin, an o-creosol novolak epoxy resin, a brominated epoxy resin, triglycidyl isocyanurate, tetrakis (glycidyloxyphenyl) ethane, an epoxidized polybutadiene, a glycidyl amine compound and a glycidyl ester compound. ### Claim 5 (depends on 1) An adhesive for copper foils according to claim 1, further consisting essentially of at least one curing agent for said epoxy resin, said curing agent being selected from the group consisting of dicyandiamide, organic hydrazides and imidazoles. ### Claim 6 (depends on 1) An adhesive for copper foils according to claim 1, further consisting essentially of at least one fire retardant selected from the group consisting of bromine compounds and antimony compounds. ### Claim 7 (depends on 1) An adhesive for copper foils according to claim 1, further consisting essentially of at least one inorganic filler selected from the group consisting of talc and powdered silica. ### Claim 8 An adhesive-backed copper foil, wherein the adhesive backing consisting essentially of: (I) a first amount of a non-modified epoxy resin and a second amount of a rubber-modified epoxy resin in a total amount of 60-100 parts by weight, wherein said second amount of said rubber-modified epoxy resin is 0.5 to 20 parts by weight; (II) 5-30 parts by weight of a polyvinyl acetal resin; and optionally, (III) at least one resin selected from the group consisting of blocked isocyanate resins, polyester resins, polyester resins, melamine resins and urethane resins. ### Claim 9 (depends on 8) An adhesive-backed copper foil according to claim 8, wherein the adhesive contains at least one resin selected from the group consisting of blocked isocyanate resins, polyester resins, polyester resins, melamine resins and urethane resins. ### Claim 10 (depends on 8) An adhesive-backed copper foil according to claim 8, wherein said rubber is a member selected from the group consisting of a butadiene rubber having a terminal carboxyl group, an acrylonitrile-butadiene copolymer, and an isoprene rubber. ### Claim 11 (depends on 8) An adhesive-backed copper foil according to claim 8, wherein said epoxy resin is a member selected from the group consisting of a bisphenol A epoxy resin, a bisphenol F epoxy resin, a novolak epoxy resin, an o-creosol novolak epoxy resin, a brominated epoxy resin, triglycidyl isocyanurate, tetrakis (glycidyloxyphenyl) ethane, an epoxidized polybutadiene, a glycidyl amine compound and a glycidyl ester compound. ### Claim 12 (depends on 5) An adhesive-backed copper foil according to claim 5, said adhesive further containing at least one curing agent for said epoxy resin, wherein said curing agent is selected from the group consisting of dicyandiamide, organic hydraides and imidazoles. ### Claim 13 (depends on 5) An adhesive-backed copper foil according to claim 5, said adhesive further containing at least one fire retardant selected from the group consisting of bromine compounds and antimony compounds. ### Claim 14 (depends on 5) An adhesive-backed copper foil according to claim 5, said adhesive further containing at least one inorganic filler selected from the group consisting of talc and powdered silica.