Verfahren zur Herstellung von Pfropfpolymerisaten des Vinylchlorids

• Main Authors: HERBERT BARTL,DR, DIETRICH HARDT,DR, WUEST,RUDOLF
• Format: Patent
• Language: German
• Published: 03.09.1970
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

Graft copolymers are made by polymerizing a mixture of vinyl chloride and a monoethylenic acid or derivative thereof or an organic vinyl ester upon a partially hydrolyzed copolymer of ethylene and a vinyl carboxylate. Suitable comonomers for use with vinyl chloride are acrylic, methacrylic, fumaric and maleic acids and their esters with monohydric and dihydric alcohols. Vinyl esters specified are vinyl acetate, propionate, butyrate and benzoate and monovinyl oxalate. Grafting is preferably effected by polymerizing in aqueous suspension a solution of the partially hydrolyzed copolymer in the vinyl chloride monomer mixture. Specified polymerization catalysts and lauroyl and benzoyl peroxides and azodiisobutyronitrile. The resulting graft copolymers may be cross-linked by reaction through their hydroxyl and carboxyl groups, if the latter are present, suitable cross-linking agents being polyisocyanates, N-methylolmelamine ethers and diisonitriles. Solutions of the polymers are used as coating compositions. Examples polymerizing in aqueous suspension solutions of partially hydrolyzed ethylene-vinyl acetate copolymers in (1) a mixture of vinyl chloride and monopropyl and monododecyl maleates, followed by cross-linking of the graft copolymer with a reaction product of trimethylolpropane and toluylene diisocyanate, (2) a mixture of vinyl chloride, vinyl acetate and monopropyl maleate, and (3) a mixture of vinyl chloride, vinyl acetate and 2-hydroxypropyl methacrylate, followed by cross-linking of the graft copolymer by the diisocyanate reaction product used in (1) or by N-hexamethylolmelamine hexabutyl ether.ALSO:Surfaces of metal, glass, paper and textiles are coated by applying thereto solutions in organic solvents of graft copolymers of vinyl chloride and a monoethylenic acid or derivative thereof or an organic vinyl ester upon a partially hydrolyzed copolymer of ethylene and a vinyl carboxylate (see Division C3). After application, solvent is removed from the composition to leave a film which may be cross-linked by means of cross-linking agents present therein, e.g. polyisocyanates or N-methylolmelamine ethers. Examples describe coating metal and glass with (1) a graft copolymer of a mixture of vinyl chloride and monopropyl and monododecyl maleates on a partially hydrolyzed ethylene-vinyl acetate copolymer, the resulting films being cross-linkable with a polyisocyanate (2) a graft copolymer of vinyl chloride, vinyl acetate and monopropyl maleate on a partially hydrolyzed ethylenevinyl acetate copolymer the resulting films being cross-linkable with polyisocyanates and methylolmelamine ethers, and (3) a graft copolymer of vinyl chloride, vinyl acetate and 2-hydroxypropyl methacrylate, the resulting films being cross-linkable with a polyisocyanate or N-hexamethylolmelamine hexabutyl ether.