GB710513A - Polyester terpolymers - Google Patents

Abstract

Terpolymers of (1) an organic solvent soluble polyhydric alcohol polyester of cis-3, 6-endomethylene delta-4-tetrahydrophthalic anhydride containing not more than three diacyl residues of the dibasic adduct per average polyester molecule, (2) styrene or its derivatives, and (3) a mono-olefinic compound having in conjunction with the double bond either a carboxyl or cyano group, are prepared by heating in solution in the presence of a catalyst. Styrene derivatives mentioned are, p-chlorostyrene, 2, 5-dichlorostyrene, p-methyl, p-ethyl and p-isopropyl styrenes, p-dimethyl-amino vinyl benzene and p-benzyl styrene. The monoolefinic compounds (2) may be acrylonitrile, methacrylonitrile, methacrylamide, N, N1-dimethylacrylamide, acrylic or methacrylic acid or their methyl, ethyl, propyl, methoxy or propoxy esters, mono- and diesters of unsaturated dicarboxylic acids, such as monobutyl maleate, and ethyl and diethyl crotonates (a long list of suitable mono- and di-carboxylic acids and their esters is given), vinyl ketones such as methyl and phenyl vinyl ketones and monohydric half esters of D 1, 4-dihydro phthalic acid, or of "Carbic" (R.T.M.) acid or anhydride. Dicarboxylic acids, e.g. phthalic, succinic and adipic acids, and monocarboxylic acids, e.g. those derived from linseed and soya oils may partially replace the anhydride (1). Solvents used may be benzene, toluene, xylene, butyl acetate, or propionate, diethyl phthalate, diethylene glycol monobutyl ether acetate, methyl isobutyl and diisobutyl ketones, and n-butyl ether, together with diluents such as mineral spirits or petroleum naphtha. The catalysts, e.g. benzoyl, p-chlorobenzoyl, and methyl amyl ketone peroxides, t-butyl per benzoate and t-butyl and cumene hydroperoxides may be added portionwise. Examples describe the preparation of polyesters from "Carbic" anhydride modified with castor oil, alone or with glycerol or ethylene glycol or a mixture of these, lauric acid, coconut and soya bean oils or their fatty acids, with glycerol; "Carbic" anhydride mixed with phthalic anhydride and castor oil or 2-ethylhexandiol 1, 3; "Carbic" anhydride with castor oil, glycerol and hydrogenated rosin; or mixed "Carbic" anhydride-phthalic anhydride with castor oil, glycerol and hydrogenated rosin acids or hydroabietyl alcohol. The polyesters are then polymerised with styrene and ethyl acrylate, 3-ethoxy propyl acrylate, methyl methacrylate, dimethyl, diethyl or dioctyl maleate, dimethyl dichloromaleate, diethylmonochloromaleate, diethyl dihydrophthalate, diethyl itaconate or citraconate, methylacrylonitrile, methacrylamide and the diethyl ester of "Carbic" anhydride. Terpolymers including acrylonitrile require solvents such as methoxyacetamide, N-formyl morpholine and N-formyl hexamethylene imine in their preparation. The terpolymers may be used in coating compositions with nitrocellulose dissolved in butyl acetate, or a blend of phenyl methyl carbinol with acetophenone, with partially hydrolysed vinyl chloride-acetate copolymer dissolved in methyl isobutyl ketone, with cellulose acetate or ethyl cellulose. Plasticizers such as dibutyl or dioctyl phthalate or ester gum may be added, and the addition of driers yields air-drying compositions. The terpolymers may also be used as plasticisers for alkylated urea-or melamine-formaldehyde resins.