Patent GB-968456-A (GB)
Title: Water-soluble copolymer salts and methods of making them
IPC: C08F8/00
Filed: 1960-09-29
Abstract: Water-soluble copolymer salts are made by reacting in an aqueous medium (A) a copolymer of (1) 1 to 5% by weight of acrylic methacrylic, dimeric methacrylic, methacryloxypropionic or methacryloxyisobutyric acid, or mixtures thereof, and (ii) a greater amount, on a weight basis, of methyl and/or ethyl acrylate, the balance, if any, of the copolymer being constituted by one or more monomers which will not, when polymerized, vitiate the water-solubilizing properties imparted by the carboxylate units and will not impart an undesirable increase in viscosity to aqueous solutions of the salts, and (B) 2-(dimethylamino)-ethanol and/or 2-methyl-2-amino-propanol-1. Optional comonomers specified are acrylamide, methacrylamide, beta-hydroxyethyl and beta-hydroxypropyl methacrylates, glycidyl and beta-(dimethylamino) ethyl acrylates and methacrylates, and N-(beta-(alpha-methacryloxy-acetamido)ethyl)-N, N1-ethyleneurea.  The copolymers may be prepared in solution in a solvent such as 2-ethoxyethanol, tert.-butanol or dioxane, or in aqueous emulsion containing an emulsifier, e.g. a copolymer salt of the present type obtained from a previously prepared batch. Polymerization is carried out with the aid of initiators, e.g. azoisobutyronitrile, alkali metal and ammonium persulphates and a mixture of tert.-butyl hydroperoxide and isoascorbic acid, and in the presence of regulators, e.g. tert.-dodecyl mercaptan, isopropanol, isobutanol, tert.-octyl alcohol, lauryl alcohol, cumene, carbon tetrachloride, tetrachloroethylene and trichlorobromomethane. The monomers and intitator may be added gradually to the polymerizing mixture during the course of the reaction.  The reaction between the copolymer and the aminoalcohol may be carried out in water, or in water containing an organic liquid, e.g. tert.-butanol.  The resulting copolymer solutions may be used in coating applications, for which purpose there may be added thereto aqueous dispersions of vinyl and acrylic polymers, phenol-formaldehyde resins, urea-formaldehyde resins, melamine-formaldehyde resins, ethyleneurea-formaldehyde resins, alcohol modified aminoplasts, e.g. a methoxylated melamine-formaldehyde resin, polyepoxides and titanium dioxide.ALSO:Surfaces of wood, metals, glass, ceramics, concrete and asbestos-cement products are coated by applying thereto aqueous solutions of water-soluble salts of (A) copolymers of (i) 1-5% by weight of acrylic, methacrylic, dimeric methacrylic, methacryloxypropionic or methacryloxyisobutyric acids, or mixtures thereof, and (ii) a greater amount, on a weight basis, of methyl and/or ethyl acrylate, the balance, if any, of the copolymer being constituted by one or more monomers which will not, when polymerized, vitiate the water-solubilizing properties imparted by the carboxylate units and will not impart an undesirable increase in viscosity to aqueous solutions of the salts, and (B) 2-(dimethylamino)-ethanol and/or 2-methly-2-aminopropanol-1 (see Division C3).  After application, the coatings are heated to dry them and, by heating to 220-450  DEG F., effect elimination of amine, with consequential curing of the coatings.  Also present in the coating compositions may be pigments, organic solvents, aminoplasts, phenoplasts and polyepoxides.  In the examples de-greased steel plates are coated by means of a spray gun with: (1) a composition consisting of a solution in water and tert. butanol of a copolymer of ethyl acrylate, methyl methacrylate, acrylamide and methacrylic acid neutralized with dimethylaminoethanol, a water-soluble methoxylated melamine-formaldehyde resin and, optionally, titanium dioxide; (4) an aqueous solution containing a copolymer of ethyl acrylate and methacrylic acid neutralized with dimethylaminoethanol and a methoyxlated melamineformaldehyde resin; and (5) as in (1) but using a copolymer prepared in aqueous emulsion instead of organic solvent solution.ALSO:A non-woven fabric formed of a plurality of superposed carded webs of a mixture of cotton and rayon fibres is padded with an aqueous solution of a copolymer of ethyl acrylate, methyl methacrylate, acrylamide and methacrylic acid neutralized with 2-methyl-2-aminopropanol-1, dried in air and heated at 150 DEG C. for five minutes, to form a unified product suitable as a backing for pressure-sensitive adhesive tape.