GB715231A - Improvements in or relating to alkyd resins - Google Patents

Abstract

An alkyd type resin is made by reacting (1) glycerine or pentaerythritol by heating with (2) a diester of terephthalic acid, isophthalic acid, a stilbene dicarboxylic acid, a diphenic acid, a tolane dicarboxylic acid or a dibenzyl dicarboxylic acid (the structure of the monocyclic aryl carboxylic acids being such that the carboxy groups are not ortho to each other) in which the alcoholic substituents of the ester are alkyl radicals, and (3) a silane or siloxane of the average general formula <FORM:0715231/IV (a)/1> where each R is an alkyl or monocyclic aryl, alkoxy or aryloxy radical, m has a value from 0 to 3, n has a value from 0.05 to 4, the sum of m+n being not greater than 4, and X is an alkoxy or aryloxy radical or a chlorine or bromine atom, the reactants (1) and (2) being employed in such an amount that the ratio of OH to the corresponding ester radical is from 4 : 1 to 1.001 : 1, and the reactant (3) is present in amount of 0.1 to 85 per cent. by weight of the total reactants. The organosilicon reactant is preferably incorporated in the alcohol-ester resin after removal of the theoretical amount of alcohol from transesterification of the acid-ester and the polyhydric alcohol. Reaction of the organosilicon component with the ester resin is effected preferably at 180 DEG to 260 DEG C. and the resulting products are cured at 200 DEG C. or above. The resins may be prepared in the presence of solvents such as quinoline, isoquinoline, tributylamine, triisobutylamine, triamylamine, isophorone, acetophenone, acetonyl acetone, dimethylformamide, diethylformamide, dimethyl acetamide, 2-ethylhexyl acetate, lauryl acetate, 2-ethylhexyl butyrate, butyl carbitolacetate, butyl cellosolve acetate, amylcarbitol acetate, diethylene glycol dipropionate, phenoxyethylene glycol acetate, diethylcarbitol, cresol and toluene; the solvent being present in amount sufficient to prevent gelation of the resin. The preferred aryl polycarboxylic acid diesters are formed from an alcohol from methanol to octanol. The resins, with or without conventional fillers, catalysts and mould lubricants are used as magnet wire enamels, for panel coating of automobiles, furnaces, stoves and smokestacks and for laminating and moulding purposes. In the example, phenylmethyldiethoxysilane was reacted with the product obtained by reacting glycerine and diethylterephthalate in the presence of zinc and calcium oxides. The product was fairly soluble in cyclohexanone. Specifications 583,754, 650,247 and 685,173 are referred to.