GB801529A - Organosilicon resins - Google Patents

Abstract

Resinous copolymers suitable as casting resins consist essentially of the reaction products of mixtures of from 24.9 to 74.6 per cent (by weight] of a vinylic compound, from 24.9 to 74.6 per cent of an unsaturated polyester resin and from 0.5 to 30 per cent of <FORM:0801529/IV (a)/1> wherein R is a monovalent saturated or unsaturated hydrocarbon radical, X is an alkoxy or hydroxy radical, n has an average value of from 1 to 2 inclusive and m has an average value of from 0.03 to 3 inclusive. The vinylic resins (monomers or polymers) specified are vinyl chloride, vinylidene chloride, acrylonitrile, vinyl alcohol, styrene, a -methyl styrene, chloro styrene, vinyl toluene, vinyl naphthalene, ethyl-vinyl benzene and vinyl acetate, and may also contain (preferably less than 10 mol. per cent of the total vinylic resin) divinyl compounds such as divinyl benzene. The polyester resins used are the reaction products of polyhydric alcohols and unsaturated dicarboxylic acids with or without other polycarboxylic acids, e.g. the reaction products of glycerine, and phthalic and maleic anhydrides, ethylene glycol and adipic and fumaric acids, propylene glycol and fumaric acid, tripropylene glycol and maleic anhydride, propylene glycol, sebacic acid and maleic anhydride, and propylene glycol, dimethyl terephthalate and dimethyl fumarate. The organosilicon compounds used may also be monomeric or polymeric, e.g. alkoxysilanes of the formula RnSi(OR1)4-n, silanols of the formula RnSi(OH)4-n and partial condensates thereof. The reactants may be reacted in any order, but preferably the organosilicon compound is reacted with the polyester resin and the resulting product is then reacted with the vinylic resin. Plasticisers, stabilizers and fillers, e.g. silica, glass, asbestos, alumina and titania, may be added. In a typical example, the polyester obtained by reaction of ethylene glycol, adipic and fumaric acids was reacted with a methoxy methylphenylpolysiloxane, and the resulting product after dilution with styrene containing t-butylcatechol as inhibitor, was mixed with a styrene solution of a polyester obtained by reaction of propylene glycol, adipic and fumaric acids, and polymerized by heating with t-butyl perbenzoate. Specification 759,197 and 766,627 are referred to.