Patent GB-1082919-A (GB)
Title: Protective coatings for plasticised polyvinyl chloride
IPC: C08G18/62
Filed: 1966-06-27
Abstract: A protective coating for shaped, plasticized vinyl chloride polymers, e.g. in the form of sheets, is applied by treating the surface of the shaped polymer with a film-forming composition comprising (a) at least one copolymer of (i) an ester of methacrylic acid with a C1- 6 alcohol, or a mixture containing a major proportion of said methacrylic ester together with an ester of acrylic acid with a C1- 6 alcohol, acrylonitrile, methacrylonitrile, a vinyl ester and/or vinyl chloride, and (ii) at least one monomer copolymerizable with component (i) and containing an active hydrogen atom capable of reacting with a polyisocyanate, component (a) containing 98 to 80% by weight of units of (i) and 2 to 20% by weight of units of (ii); (b) 1 to 15% by weight (based on the weight of component (a)) of a polyisocyanate; (c) an organic solvent; and evaporating the organic solvent, preferably at 70-100 DEG  C.  In a modification, the copolymer(s) of the film-forming composition can be replaced by a mixture of homopolymers, or a mixture of at least one homopolymer and at least one copolymer, derived from the specified components (i) and (ii), the overall proportions of these components being as specified above for the original copolymer(s).  Suitable monomer components (ii) include hydroxyalkyl acrylates and methacrylates, acrylamide and methacrylamide and hydroxyalkyl derivatives thereof, acrylic, methacrylic, itaconic, a -methylene-a 1-methyl-adipic and b -acryloxypropionic acids, monomethyl fumarate, N-methacrylyl-taurine, 3-methacryloxypropanesulphonic acid, p-styrenesulphonic acid and 2 - acryloxy - n - propyl - phosphonic acid.  The polyisocyanate may be a low or high molecular weight product obtained by reacting toluene-2,4-diisocyanate with polyalcohols. The solvent illustrated is an ethyl acetate/methyl ethyl ketone mixture, optionally also including toluene, n-butyl acetate and cyclo-hexanone.  In examples, component (a) is (1) a methyl methacrylate-butyl methacrylate - hydroxyethyl - methacrylamide copolymer, (2) methyl methacrylate - isobutyl methacrylate-hydroxypropyl acrylate copolymer, (3) methyl methacrylate-butyl methacrylate-hydroxy ethyl methacrylate-methacrylamide copolymer, and (4) a combination of methyl methacrylate - methyl acrylate - methacrylamide copolymer with a vinyl chloride-vinyl acetate-maleic acid copolymer.ALSO:A protective coating for shaped, plasticised vinyl chloride polymers, preferably in sheet form and particularly as artificial leather, is applied by treating the surface of the shaped polymeric material with a film-forming composition comprising (a) at least one copolymer of 98-80% by weight of a methacrylic acid ester of a C1-6 alcohol, or a mixture of a major proportion of said ester with an acrylic acid ester of a C1-6 alcohol, acrylonitrile, methacrylonitrile, a vinyl ester and/or vinyl chloride, and 2-20% by weight of a copolymerisable monomer containing an active hydrogen atom capable of reacting with a polyisocyanate; (b) 1 to 15% by weight of component (a) of a polyisocyanate; (c) an organic solvent; and evaporating the organic solvent, preferably at 70-100 DEG C.  In a modification the specified monomer components, instead of being combined in the same copolymer, can be incorporated in a mixture of homopolymers or a mixture of a least one homopolymer with at least one copolymer.  Suitable monomers reactive with polyisocyanates include hydroxyalkyl acrylates and methacrylates, acrylamide and methacrylamide and hydroxyalkyl derivatives thereof, and unsaturated carboxylic sulphonic or phosphonic acids.  The polyisocyanate may be a low or high molecular weight product obtained by reacting toluene -2, 4-diisocyanate with poly alcohols.  The solvent illustrated is an ethyl acetate/methyl ethyl ketone mixture, optionally also including toluene, n-butyl acetate and cyclohexanone.  The coating can be applied by knife coating or with a rubber cloth spreader or engraved roller.