GB735456A - Improvements in or relating to a process for the preparation of copolymers of aromatic vinyl hydrocarbons and alkyd resins - Google Patents

Abstract

Styrenated oil-modified alkyd resins are obtained by heating pre-determined proportions of (a) one or more copolymers of styrene or a substitution product or derivative thereof, e.g. halogenated styrene or a -methyl styrene, with an unsaturated fatty oil acid and/or a polyhydric alcohol ester thereof, and (b) one or more unsaturated fatty oil acids and/or polyhydric alcohol esters of these acids, with one or more polybasic acids, e.g. phthalic or maleic acid, with or without one or more polyhydric alcohols, e.g. glycerol or pentaerythritol. The fatty oil acid or ester copolymers may be prepared by alcoholising an oil copolymer with a polyhydric alcohol, by reacting styrene with monoglycerides, or by reacting styrenated fatty acids with polyhydric alcohols. In a modification the polybasic acid or acids are first reacted with the copolymer (a), with or without one or more polyhydric alcohols as may be necessary to form an alkyd resin containing free hydroxyl groups, which is then esterified with predetermined proportions of (b). The copolymer may be formed from a mono-ester of the polyhydric alcohol and may be prepared from semi-drying oils or their acids, e.g. linseed, sunflower and soyabean. The fatty oil acids (b) may be of high oxidative drying power such as those of wood oil and isomerised or blown linseed oil. In examples a styrene-varnish linseed oil copolymer is reacted with glycerol, the product heated with phthalic anhydride and glycerol with a phosphoric acid catalyst, and finally heated with wood oil.