Patent GB-1089500-A (GB)
Title: Crosslinking agents for polymers
IPC: C08L57/00
Filed: 1965-10-20
Abstract: Interpolymers having at least one reactive monomer component (e.g. hydroxyl, carboxyl, epoxy or amide) are cross-linked by a mixture of: (a) a polycycloaliphatic polyepoxide, each cycloaliphatic ring of which contains 5 or 6 carbon atoms and at least one epoxide group and (b) from 10 to 90% by weight of a hexaalkoxymethylmelamine in which the alkoxy group contains 1 to 4 carbon atoms (e.g. hexamethoxymethylmelamine). The cross-linking composition may be present at 0.5 to 30% by weight of the interpolymer.  Examples of suitable polyepoxides are: 3,4-epoxy-6-methyl-cyclohexylmethyl, 3,4 - epoxy - 6 - methyl-cyclohexane carboxylate, bis - (3,4 - epoxy-6-methylcyclohexylmethyl) adipate, bis-(2,3-epoxycyclopetyl) ether, 1,2 - bis - (2,3 - epoxy-cyclopentoxy) ethane.  Reactive polymers exemplified are copolymers of (A) styrene or vinyl toluene, (B) an acrylate, e.g. n-butyl 2-ethylhexyl, lauryl, n-octyl and/or hydroxyethyl and (c) methacrylamide, N-methylolacrylamide, a methacrylate, e.g. 2-hydroxypropyl or glycidyl, an acid, e.g. methacrylic or acrylic, and/or methacrylamide, a copolymer of (A) styrene and/or acrylonitrile, (B) butadiene, and (C) methacrylic acid; or a terpolymer of vinyl acetate, n-butyl acrylate and methacrylamide. The copolymers may be prepared by polymerizing the monomers in an aq. mixture of sodium lauryl sulphate, nonylphenoxypolyethyleneoxyethanol and ammonium persulphate, and adjusting the pH of the product to 8.5-9.0 with NH4OH.ALSO:Fabrics, e.g. a non-woven random web of rayon, acetate and nylon, are impregnated with an aqueous emulsion of a copolymer containing active monomer groups (e.g. OH, COOH, epoxy or amide and as cross-linking agent a mixture of polycycloaliphatic polyepoxide each ring of which contains 5 or 6 carbon atoms and from 10-90% by wt. of a hexaalkoxymethyl melamine in which the alkoxy group contains 1 to 4 carbon atoms.  The cross-linking agent may be present at from 0.5 to 30% by wt. of the polymer. Cross-linking may be achieved by heating, e.g. for 3 minutes at 310 DEG F.  Reactive polymers exemplified are copolymers of: (A) styrene or vinyl toluene, (B) an acrylate, e.g. n-butyl, 2-ethyl hexyl, lauryl, n-octyl and/or hydroxyethyl, and (C) methacrylamide, N-methylolacrylamide, a methacrylate, e.g. 2-hydroxypropyl or glycidyl, an acid, e.g. methacrylic or acrylic and/or methacrylamide; a copolymer of (A) styrene and/or acrylonitrile, (B) butadiene and (C) methacrylic acid; or a terpolymer of vinyl acetate, n-butyl acrylate and methacrylamide.ALSO:Protective coatings (e.g. for steel) are obtained from solutions of a polymer which contains reactive groups (e.g. OH, COOH, epoxy or CONH2) and as cross-linking agent a mixture of a polycycloaliphatic polyepoxide each ring of which contains 5 or 6 carbon atoms and at least one epoxide group and from 10 to 90% by wt. of hexoalkoxymethylmelamine in which the alkoxy groups contains 1 to 4 carbon atoms.  The cross-linking agent may be present at from 0.5 to 30% by wt. of the polymer.  Reactive polymers exemplified are copolymers of: (A) styrene or vinyl toluene, (B) an acrylate, e.g. n-butyl, 2-ethylhexyl, lauryl, n-octyl and hydroxyethyl acrylate and (C) methylacrylamide, N-methylolacrylamide, a methacrylate, e.g. 2-hydroxypropyl or glycidyl, an acid, e.g. methacrylic or acrylic and/or methacrylamide; a copolymer of (A) styrene and/or acrylonitrile, (B) butadiene, and (C) methacrylic acid; or a terpolymer of vinyl acetate, n-butyl acrylate and methacrylamide.  In examples: (1) a steel panel is coated with a butanol/xylene solution of a copolymer of styrene (33%), 2-ethyl hexyl acrylate (62%), hydroxyethyl acrylate (2%) and methacrylic acid (3%) which is cross-linked with a mixture of hexamethoxymethylmelamine and 3,4-epoxy-6-methyl cyclohexylmethyl, 3,4-epoxy-6-methyl-cyclohexancarboxylate by heating for 30 mins. at 300 DEG F. (2) An 80 x 80 cotton base is coated with a 48% aqueous emulsion of the copolymer (1) above and the same cross-linking composition together with 1% by wt. of the composition of NH4Cl and t-octylphenoxypolyethoxyethanol and flocked with 1/4 " nylon staple. After curing for 15 mins. at 310 DEG F the fabric demonstrated no deflocking when subjected to washing and dry-cleaning solvent tests.