Patent GB-757770-A (GB)
Title: Improvements in the production of water-soluble polymers
IPC: C08F226/10
Filed: 1954-08-10
Abstract: Water-soluble copolymers are made by copolymerizing a mixture of methacrylamide and 6 to 99 per cent of N-vinyl pyrrolidone, based on the total monomers; also present may be other unsaturated carboxylic acid amides with 3 to 4 carbon atoms such as acrylamide, crotonamide and fumaric acid diamide.  Suitable catalysts for use in the polymerization are azo-bis-nitriles such as azo-bis-isobutyronitrile. After polymerization part of the amide groups of the copolymer may be saponified and the carboxy groups obtained in the form of ammonium salts.  The copolymers are used as dispersing agents in the production of aqueous dispersions of olive oil, paraffin wax, the butyl ester of 2,4-dichlorophenoxyacetic acid and a condensation product of phthalic acid, glycerine and linseed oil acid, and as dispersing agents in the aqueous dispersion polymerization of ethylenically unsaturated compounds such as vinyl esters of organic acids, acrylic and methacrylic esters, vinyl and vinylidene halides, N-vinyl carbazole, styrene, vinyl ketones, and mixtures thereof with each other and other unsaturated mono- and di-carboxylic acids and their salts, esters and amides, unsaturated nitriles, alcohols and hydrocarbons.  In examples copolymers of methacrylamide and vinyl pyrrolidone are used as dispersing agents in the polymerization of: (7) vinyl propionate in an aqueous medium containing potassium persulphate; (8) a mixture of vinyl acetate, crotonic acid and acrylic acid in an aqueous medium having a pH of 4.8 and containing potassium persulphate; (9) vinyl propionate in an aqueous medium containing sodium octodecanesulphonate and potassium persulphate, the monomer being added gradually during the course of the reaction; (11) ethyl acrylate in an aqueous medium containing butanol and potassium persulphate, the monomer being added gradually as the reaction proceeds; and (12) a mixture of vinyl chloride and vinyl propionate in an aqueous medium containing potassium persulphate. In further examples (14) vinyl propionate is polymerized in an aqueous medium containing a copolymer of methacrylamide, acrylamide and vinyl pyrrolidone and potassium persulphate, the monomer being aded gradually as the reaction proceeds; (15) vinyl propionate is polymerized in an aqueous medium containing a copolymer of methacrylamide, crotonamide and vinyl pyrrolidone and potassium persulphate; and (16) a mixture of vinyl acetate and vinyl propionate is polymerized in an aqueous medium containing a copolymer of methacrylamide, fumaric acid diamide and vinyl pyrrolidone, the monomer mixture being added gradually as the reaction proceeds.ALSO:Oils, fats and waxes are emulsified or dispersed in water containing as dispersing agents copolymers made from vinyl pyrrolidone and methacrylamide and optionally other unsaturated amides containing 3 or 4 carbon atoms.  In examples olive oil is emulsified in water containing a copolymer of methacrylamide and vinyl pyrrolidone and sodium diisopropylnaphthalene sulphonate, and paraffin wax is emulsified in water containing a copolymer of methacrylamid and vinyl pyrrolidone and an ethylene oxide treated castor oil.ALSO:A weed killer composition is prepared by emulsifying butyl 2.4-dichlorophenoxyacetate in water containing a copolymer of vinyl pyrollidone and methacrylamide and an ethylene oxide treated castor oil.