GB896821A - Improvements in production of carboxy copolymers and of cross-linked products therefrom - Google Patents

Abstract

In the solution polymerization of an alphabeta ethylenically unsaturated monocarboxylic acid with a monoethylenically unsaturated polymerizable monomer, polymerization is effected with addition, prior to the end of the polymerization, of a potentially reactive medium as a solvent and with removal of any volatile solvent present during the polymerization, the potentially reactive medium having a viscosity not exceeding 130 centipoises at the reaction temperature and a boiling point of at least 150 DEG C., and being selected from monoepoxides, polyepoxides, monohydric alcohols having more than six carbon atoms, polyhydric alcohols, carboxylic acids and carboxylic acid anhydrides. The polymerization reaction is preferably carried out completely in the potentially reactive medium. The ethylenically unsaturated monocarboxylic acid may be acrylic, methacrylic, crotonic, itaconic, citraconic, maleic or fumaric acid or a half ester of maleic or fumaric acid, and the polymerizable monomer may be styrene, vinyl toluene, alpha-methyl styrene, isopropenyl toluene, a dialkyl styrene, o-, m-, or p-halo- or cyano styrene, vinyl naphthalene, di-, tri- and tetra-chloro, bromo or flouro styrenes, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec.-butyl, amyl, hexyl, heptyl, octyl, decyl or dodecyl acrylate, methacrylate or crotonate, acrylonitrile, methacrylonitrile, vinyl methyl, ethyl or butyl ether, ethyl methallyl ether, vinyl acetate or stearate, or allyl, methallyl or crotyl propionate or butyrate. The polymerization reaction may be accelerated by heat or a peroxide catalyst such as benzoyl, phthalic, acetyl, lauroyl or ditertiarybutyl peroxide or cumene or tertiary butyl hydroperoxide. The potentially reactive solvent is one which is non-reactive under polymerizing conditions but which acts as a cross-linking agent for the polymer or reacts with added cross-linking agents at curing temperatures and, if necessary, in the presence of a catalyst, and may be a monocarboxylic acid or anhydride thereof such as benzoic, capric, caproic, myristic or palmitic acid or propionic or butyric acid or anhydride, a polycarboxylic acid or anhydride thereof such as phthalic anhydride, succinic anhydride, glutaric acid, sebacic acid, isosuccinic acid, a mixture of acids such as tetrahydrophthalic and hexachloroendomethylenetetrahydrophthalic acids or hexahydrophthalic anhydride, a monohydric alcohol such as capryl, stearyl, lauryl, 2-ethylhexyl or nonyl alcohol, a polyhydric alcohol such as ethylene, propylene, diethylene, dipropylene, triethylene, tripropylene or tetraethylene glycol, glycerin, sorbitol or trimethylol propane, or mixtures of polyoxyethylene or polyoxypropylene glycols having average molecular weights of from 200 to 1,000, a monoepoxide such as styrene oxide, glycidol, phenyl glycidyl ether, glycidyl acetate, glycidyl benzoate or butyl glycidyl ether, or a polyepoxide such as glycidyl polyethers of polyhydric alcohols and polyhydric phenols prepared by reacting the alcohol or phenol with a halohydrin such as p epichlorhydrin in the presence of an alkali, an epoxy ester made by the epoxidation of unsaturated esters with peracetic or performic acid or an epoxidized drying oil, acid or ester. If the reactive solvent is not a crosslinking agent then a cross-linking agent such as a polyepoxide or a dibasic or polybasic acid anhydride or a mixture of polyepoxide and acid anhydride is added before curing, which is effected by heating, preferably in the presence of a catalyst such as sodium or calcium hydroxide, dimethylamino phenol, benzyldimethylamine or benzyl trimethylammonium acetate or chloride. Specification 675,180 is referred to.