Patent GB-831881-A (GB)
Title: Water-soluble copolymers derived from acrylamide, methacrylamide and acrylic acid esters
IPC: C08F2/04
Filed: 1957-03-15
Abstract: Aqueous dispersions of water-immiscible substances are prepared with the aid, as dispersing agents, of water-soluble copolymers of methyl and/or ethyl acrylate and acrylamide and methacrylamide which contain at least 8% and at most 50% of the acrylate esters and at most 92% of acrylamide and methacrylamide, the methacrylamide content being between 30 and 90% with reference to the total weight of acrylamide and methacrylamide.  Substances which may be dispersed are oils, fats, waxes, hydrocarbons, nitrocellulose, condensation products of dicarboxylic acids and polyalcohols and organic and inorganic pigments.  In examples: (7) paraffin wax is dispersed in an aqueous solution of a copolymer of methyl acrylate, methacrylamide, acrylamide and sodium vinyl sulphonate; (8) olive oil is dispersed in an aqueous solution of a copolymer of methyl acrylate, methacrylamide and acrylamide; and (9) a condensation product of phthalic acid, glycerine and linseed oil acids is dispersed in an aqueous solution of a copolymer as in (8).ALSO:Copolymers are made by homogeneously dissolving in water a mixture of monomers comprising 8 to 50% of methyl and/or ethyl acrylate and up to 92% of acrylamide and methacrylamide, the mixture of amides containing at least 30% and at most 90% of methacrylamide, and then polymerizing the monomer mixture which may optionally contain other polymerizable monomers such as acrylic, methacrylic and crotonic acids and their salts, acrolein, allyl and methallyl alcohols, methyl vinyl carbinol, N-vinyl pyrrolidone, vinyl caprolactam, sodium vinylsulphonate and N-methyl, N-ethyl, N-dimethyl and N-diethyl acrylamides. Polymerization may be carried out with the aid of catalysts such as hydrogen peroxide, acetyl peroxide; potassium persulphate, azo-di-isobutyronitrile and redox systems, e.g. a mixture of potassium persulphate and formaldehyde sulphoxylate; in addition, polymerization may be initiated by ultraviolet light.  The copolymers are water-resistance of which may be improved by reaction with formaldehyde or condensate containing methylol groups; the copolymers are also used as protective colloids in the preparation of dispersions of oils, fats, waxes, hydrocarbons, acids and polyalcohols and pigments, and in the aqueous dispersion polymerization of monomers such as vinyl acetate and propionate, vinyl chloride, styrene, vinyl ketones and mono- and di-carboxylic acids and their derivatives.  In examples of the protective colloid application of the copolymers: (5) vinyl propionate is polymerized by gradual addition to an aqueous solution of a copolymer of methyl acrylate, methacrylamide and acrylamide containing sodium persulphate, (6) a mixture of vinyl acetate and vinyl chloride is polymerized as in (5), (7) paraffin wax is dispersed in an aqueous solution of a copolymer of methyl acrylate, methacrylamide, acrylamide and sodium vinyl sulphonate, (8) olive oil is dispersed in an aqueous solution of a copolymer of methyl acrylate, methacrylamide and acrylamide, and (9) a condensation product of phthalic acid, glycerine and linseed oil acids is dispersed in an aqueous solution of a copolymer as in (8).