GB828894A - Improvements in polymerisation - Google Patents

Abstract

Acrylic or methacrylic or unsaturated polyesters are polymerized by adding thereto one or more substances from the following groups:-(i) drier metal salts soluble in the esters to be polymerized, e.g. cobalt naphthenate, in a quantity from 0.0001 to 0.5% by weight of metal on the reaction mixture; (ii) a mono-aryl-N-dialkylamine such as N-dimethyl or N-diethyl aniline or toluidine, N,N1-tetramethyl phenylene diamine, N,N1-tetramethyl diaminodiphenylene diamine, N,N1-tetramethyl diamino-diphenylmethane or piperidine in quantities of from 0.1 to 5.0% by weight of the reaction mixture; and (iii) organic acids, such as acrylic, methacrylic, acetic and phthalic acids in quantities of from 0.1 to 20% by weight of the reaction mixture. Monomeric materials specified are methyl, ethyl, butyl and lauryl methacrylates, a propylene glycol maleate/phthalate polyester, and styrene and methyl methacrylate as monomers copolymerizable with the polyesters. In one mode of operation two monomeric mixtures may be prepared, one containing substances from two of the above groups and the other containing a substance from the remaining groups and mixing the two monomeric materials when polymerization is required. In Examples 1-3 the polymerization of methyl methacrylate is described, in Example 4 cotton or glass cloth is impregnated with polymethyl methacrylate containing cobalt naphthenate and is then wetted with methyl methacrylate containing N-dimethyl aniline and glacial acetic acid, and in Example 5 a propylene glycol maleate/phthalate polyester is copolymerized with methyl methacrylate, optionally containing fillers and pigments such as mica, cotton or rayon flock and titanium dioxide.