Patent GB-1093215-A (GB)
Title: Finishing coat on plasticized polyvinyl chloride
Inventor: WELZEL GERHARD
IPC: C08J7/046
Filed: 1965-02-26
Abstract: Compositions for use as a finishing coat on plasticized polyvinyl chloride films comprise aqueous dispersions of a copolymer of: (A) 40 to 90% by weight of methyl methacrylate; (B) 1 to 20% by weight of an ester of a polymerizable a ,b -ethylenically unsaturated carboxylic or di-carboxylic acid with a polyhydric alcohol bearing a chlorine atom in a -position to a free hydroxyl group; and (C) up to 59% by weight of one or more other ethylenically unsaturated, polymerizable compounds, the sum of the percentages of (A), (B) and (C) totalling 100. Examples of (B) are chlorohydrin esters of acrylic, methacrylic, fumaric and maleic acids with polyhydric alcohols such as 3 - chloropropanediol - (1,2); (2,3) - dichlorobutanediol - (1,4); 3 - chlorobutanetriol-(1,2,4); (1,4) - dichlorobutanediol - (2,3); 3-chloro - 2 - methyl propanediol - (1,2) and 3 - chloro - 2 - chloromethylpropanediol - (1,2). Examples of (C) are N-methylol methacrylamide, styrene, a -methyl styrene, vinyl acetate, acrylic or methacrylic acid, acrylo- or methacrylonitrile and acrylic esters of alcohols having 1 to 18 carbon atoms.  The polymers are obtained by polymerization of the monomers in aqueous dispersion, the dispersions having a polymer content of 25 to 60% by weight.  The dispersion may also include thickening agents such as vinylpyrrolidone-vinyl propionate copolymers; precondensates of formaldehyde with urea or melamine, e.g. dimethylol propyleneurea, dimethylolethylenurea, N,N1,N11, N111 - tetramethylolglyoxaldiureine, N,N1-dimethylol - glyoxalmonoureine or N,N1-dimethylolurea etherified with methanol; wetting agents such as sodium isopropylisohexyl-naphthalene sulphonate and buffers, e.g. an aqueous solution of NaHCO3 or NH4Cl.ALSO:Finishing coats on plasticised polyvinyl chloride films are produced by applying an aqueous dispersion of a copolymer of: (A) 40 to 90% by weight of methyl methacrylate (B) 1 to 20% by weight of an ester of a polymerizable a ,b -ethylenically unsaturated carboxylic or dicarboxylic acid with a polyhydric alcohol bearing a chlorine atom in a -position to a free hydroxyl group, and (C) up to 59% by weight of one or more other ethylenically unsaturated, polymerizable compounds, the sum of the percentages (A), (B) and (C) totalling 100, and drying the coating.  Examples of (B) are chlorohydrin esters of acrylic, methacrylic, fumaric and maleic acids with polyhydric alcohols such as 3-chloropropanediol-(1,2), (2,3)-dichlorobutanediol-(1,4) 3-chlorobutanetriol-(1,2,4), (1,4)-dichlorobutanediol-(2,3), 3-chloro-2-methyl propanediol-(1,2) and 3-chloro-2-chloromethylpropanediol.  Examples of C are acrylic or methacrylic acid, acrylo- or methacrylonitrile, acrylic esters of alcohols having 1 to 18 carbon atoms, n-methylol methacrylamide, styrene, a -methyl styrene, vinyl acetate.  Thickening agents may be added to the dispersion which may be applied as a paste by a coating knife.  Examples disclose vinylpyrrolidone copolymers as thickening agents.  Precondensates of formaldehyde with urea or melamine may be added to the dispersion such as aminoplasts, e.g. dimethylolpropylenurea, dimethylolethylenurea, N, N\sv, N\yF, N\yG-tetramethylol glyoxaldiureine, N, N\sv-dimethylol-glyoxalmonoureine or N, N\sv-dimethylolurea etherified with methanol.  In some of the Examples the plasticized polyvinyl chloride is in the form of a coating on a substrate such as cloth and is pregelled at 120 DEG  to 130 DEG C, the finishing coat then spread on and gelling completed at 170 DEG  to 180 DEG C, and finally embossed.  A wetting agent is present in the aqueous dispersion in some cases.