GB796006A - Improvements in unsaturated alkyd resins - Google Patents

Abstract

A polymerizable or copolymerizable unsaturated polyester which is terminated at both ends of the molecule by groups of an allylic or methallylic monoester of a butenedioic acid containing 4-6 carbon atoms is made by (a) esterifying the monoallylic ester of the butenedioic acid with a hydroxy terminated linear polyester derived from a glycol, a non-olefinic dicarboxylic acid and, if desired, an olefinic dicarboxylic acid, at least 33 mol. per cent of the dibasic acid units in the final polyester being non-olefinic, or by (b) reacting 2 mols. of the mono-allylic ester of the butenedioic acid with a mixture of at least 2 mols. of a glycol and at least one mol. of at least one dicarboxylic acid, enough of said dicarboxylic acid being non-olefinic so that at least 33 mol. per cent of the dibasic acid units in the polyester are non-olefinic. In process (h) the mono-allyl ester may be made by reacting the anhydride of the butenedioic acid with the allyl or methallyl alcohol in presence of the non-olefinic dicarboxylic acid which acts merely as an inert diluent. The butendioic acid may be maleic, fumaric, citraconic, mesaconic, dimethyl maleic or ethyl maleic acid and the saturated dicarboxylic acid may be oxalic, malonic, succinic, glutaric, adipic, azelaic, sebacic, diglycolic, phthalic, isophthalic, terephthalic or naphthalene dicarboxylic acid. Reaction may be effected in presence of an azeotropic agent or an inhibitor (e.g. hydroquinone, quinone or p-tert.-butylcatechol). In examples: (1) a polyester made by heating a mixture of allyl alcohol and maleic anhydride in presence of adipic acid, followed by the addition of ethylene glycol and further heating was polymerized alone or with methyl methacrylate or styrene; (2) a polyester made by heating a mixture of mono-allyl maleate, succinic anhydride and ethylene glycol was polymerized either alone or with methyl methacrylate; (3) a polyester made by heating a mixture of mono-allyl maleate, phthalic anhydride and ethylene glycol was polymerized either alone or with styrene, diallyl phthalate or methyl methacrylate; (4) a polyester made by heating a mixture of maleic anhydride and allyl alcohol in presence of diglycolic acid followed by the addition of diethylene glycol and further heating was polymerised either alone or with styrene, diallyl phthalate or methyl methacrylate; (5) a polyester derived from adipic acid, maleic anhydride and ethylene glycol was heated with monoallyl maleate and the product polymerized alone or with styrene, diallyl phthalate or methyl methacrylate; (6) a polyester derived from adipic acid, phthalic anhydride, ethylene glycol and diethylene glycol was heated with monoallyl maleate and the product polymerized alone or with diallyl phthalate or styrene; (7) a polyester derived from adipic acid, phthalic anhydride, maleic anhydride, ethylene glycol and diethylene glycol was heated with mono-allyl maleate and the product polymerized alone or with diallyl phthalate or styrene. In all examples, the polymerization catalyst was a mixture of benzoyl peroxide and tricresyl phosphate.