GB809658A - Polymerisable compositions - Google Patents

Abstract

A polymerizable composition comprises a copolymer of methyl methacrylate with a minor amount of a polymerizable carboxylic acid, a polyepoxy compound, a basic organic catalyst, a solvent and a polymeric plasticizer. The polymerizable carboxylic acid may be methacrylic, acrylic, crotonic, fumaric, maleic or itaconic acid; in place of the acid, an anhydride such as maleic anhydride may be used and other components such as acrylates and methacrylates may be present in the copolymer in minor amount. The polyepoxy compound may be 1 : 2-3 : 4 - diepoxybutane, 1 : 2-5 : 6 - diepoxy - 2 : 5 - dimethylhexane, methyl di(2 : 3 - epoxypropyl) acetate, 1 : 4 - divinylbenzene diepoxide, di - (2 : 3 - epoxy propyl) ether, glycerol tri - (2 : 3 - epoxypropyl) ether, m - or p - di - (2 : 3 - epoxypropyl) - benzene, 1 : 3 : 5 - tri (2 : 3 - epoxy propoxy) - benzene, 2 : 2 - di - [4 - (2 : 3 - epoxypropoxy) phenyl] propane, N : N - di - (2 : 3 - epoxypropyl) - aniline, N : N - di - (2 : 3 - epoxypropyl) p - anisidine, (2 : 3-epoxy) sorbate dimer, di-(2 : 3 epoxypropyl) sebacate, itaconate, or isophthalate, tri-(2 : 3-epoxypropyl trimesate or N : N-di - (2 : 3 - epoxypropyl) p - t p - toluene sulphonamide. Other polyepoxides which may be used are polymers obtained by reacting polyhydric phenols with epichlorhydrin or glycerol dichlorhydrins in presence of alkali. Mixtures of polyepoxides with monoepoxides such as phenyl 2 : 3-epoxypropyl ether and 2 : 3-epoxypropylN-phenylcarbamate may also be used. The catalyst may be 2 : 4 : 6-tri (dimethylaminomethyl) phenol, triethylamine, dimethylaniline, pyridine, N : N - dimethyl - 1 : 3 - propanediamine, diethylenetriamine, 2 : 5 - di (dimethylaminomethyl) - quinol, N : N - dimethyl - cyclohexylamine, N : N - dimethylbenzylamine, N : N : N1 : N1 - tetramethylhexamethylene diamine, 2 - (dimethylaminomethyl) cyclohexanone, phenyl - 2 - (dimethylamino) ethyl ketone, di - [2 - (diethylamino) ethyl] adipate, N - ethylhexamethyleneimine, hexamethyleneimine, N - methylbenzylamine, benzyltrimethylammonium hydroxide, or a substance which breaks down on heating to give amines such as benzyltrimethylammonium acetate or the triacetate from 2 : 4 : 6-tri-(dimethylaminomethyl) phenol. The solvent may be xylene, butanol, toluene, methyl ethyl ketone, ethyl acetate or mixtures thereof. The polymeric plasticizer is preferably a liquid mixed polyester formed by the condensation of a glycol, an aliphatic dicarboxylic acid and an aromatic monocarboxylic acid, and optionally also an aliphatic monocarboxylic acid, or mixtures thereof, as described in Specification 775,764. The composition may also contain pigments such as titanium dioxide and iron oxides. The compositions may be used to coat light alloy, steel or wood surfaces by spraying or brushing, polymerization being then effected by stoving, generally at 60-120 DEG C.