GB758724A - Improvements relating to synthetic resins - Google Patents

Abstract

A synthetic resin for use in paints, varnishes and baking enamels is the reaction product of a copolymer of an unsaturated monocarboxylic fatty acid and a monovinyl aromatic compound, a polyhydric alcohol and a polysiloxane containing alkoxy groups, and/or halogen atoms. The resin may be made by reacting the siloxane with the alcohol and with the copolymer, but is preferably made by reacting the alcohol with the copolymer and reacting the resulting ester with the siloxane. There are specified (a) monovinyl aromatic compounds-styrene, a - methylstyrene, p-methylstyrene, a -p-dimethylstyrene, divinylbenzene, vinylnaphthalene, acenaphthylene, vinyltoluene, p-chlorostyrene, p-trichloromethylstyrene, 2 : 5-dichlorostyrene, p-methoxystyrene or mixtures thereof; (b) unsaturated fatty acids-acrylic, methacrylic, vinylacetic, hydrosorbic, decenoic, undecylenic, sorbic, hiragonic, linoleic, isolinoleic, elaeostearic, punicic, parinaric, arachidonic, clupanodonic, scoliodonic, nisinic, tariric, abietic and licanic acids; castor-, linseed-, soyabean-and tung-oil fatty acids, rosin acids and tall oil acids; the dimers and trimers of these acids may also be used; (c) polyhydric alcohols-ethylene-, diethylene-, propylene- and trimethylene-glycols, glycerine, trimethylol propane, pentaerythritol, polyallyl alcohol, sorbito-and mannitol. The alkoxy polysiloxanes specified conform to the formula <FORM:0758724/IV(a)/1> where R is a lower alkyl radical (i.e. of 1 to 4 C atoms), R1 is an alkyl or aryl radical, R11 is R1 or alkoxy and n is at least 2. The halogenopolysiloxanes specified are dimethyltriphenyltrichlorotrisiloxane and trimethyltriphenyldichlorotrisiloxane. In making the copolymers, the proportions by weight are preferably 5 to 75 per cent of the vinyl monomer and 95 to 25 per cent of the acid, and the reaction is desirably effected under reflux at 150 DEG to 475 DEG F. in the presence of a solvent and a catalyst or controlling agent, e.g. hydrogen peroxide, benzoyl peroxide, t-butyl peroxide, di-tertiary butyl peroxide, acetyl peroxide in dimethyl phthalate, fuller's earth, sulphur, sulphur dioxide, stannic chloride, boron trifluoride or a redox catalyst such as a mixture of dodecyl mercaptan and benzoyl peroxide or benzidine and sulphur dioxide, and desirably in an inert atmosphere, e.g. nitrogen or carbon dioxide. Examples A1 to A19 describe the preparation of the copolymers and examples B1 to B13 describe the preparation of the resinous reaction products. U.S.A. Specifications 2,415,389, 2,584,343 and 2,587,295 are referred to.