GB804158A - Improvements in or relating to resinous compositions - Google Patents

Abstract

A composition polymerizable through ethylenic bonds under the action of heat and/or actinic light comprises (a) from 35 to 65 per cent of a silane or siloxane containing at least one group of the formula <FORM:0804158/IV (a)/1> where Y is a vinyl or allyl radical and X is an alkoxy or aryloxy radical, (b) from 65 to 35 per cent of a polyester resin selected from (1) esters obtained by reacting isophthalic or terephthalic acid with at least one alpha-beta ethylenically unsaturated dicarboxylic acid and at least one polyhydric alcohol or (2) the acid half-ester obtained by reacting at least one polyhydric alcohol ester of a hydroxylated unsaturated fatty acid with at least one alpha-beta ethylenically unsaturated dicarboxylic acid or anhydride thereof, and (c) at least one addition-type polymerization catalyst. The composition may also contain solid fillers such as silica, chopped glass fibres, asbestos fibres, powdered glass, iron oxide, titanium dioxide, bentonite, kaolin, catalpa clay, aluminium oxide, inorganic silicates or graphite. The silicon-containing compound may be dimethoxymethyl vinylsilane, diethoxyphenylvinyl silane, diethoxyphenylallylsilane, dimethoxytrimethyl- or diethoxytriphenyltrivinyl-trisiloxane, or diethoxytriphenyltrivinylphenoxytrisilane, or diethoxytriphenyltriallyltrisiloxane. Polyhydric alcohols mentioned are 2,2 - bis - (para - hydroxyethoxy-phenyl or biphenyl or ethoxyphenyl) propane and 2,2-bis-(para - hydroxypropoxy - phenyl or -propoxyphenyl) propane, and the corresponding diphenylols. In (b) (2) alcohols such as glycol, propylene glycol or neopentyl glycol may be used. Specified unsaturated acids and anhydrides are maleic, fumaric, itaconic, citraconic, mesaconic, aconitic, and mixtures. The hydroxylated unsaturated fatty acid ester may be castor oil admixed if desired with esters of monohydroxy- or dihydroxy-stearic acid. The catalyst may be benzoyl, lauroyl, or methyl ethyl ketone peroxide, t-butyl hydroperoxide, ascaridole, tert.-butyl perbenzoate, di-tert.-butyl diperphthalate, or an ozonide, admixed, if desired, with an accelerator such as cobalt naphthenate, or a nitrogen-containing organic compound. The catalyst is generally included in the composition as a dispersion in tricresyl phosphate. The compositions may be used for impregnating glass-fabrics and in the preparation of laminates, e.g. in the manufacture of aircraft domes, as transformer insulators, and in the moulding of articles. In Example 1 an unsaturated polyester resin made by reacting 2,2 - bis - (para-hydroxyethoxyphenyl) propane with isophthalic acid and maleic anhydride is mixed with diethoxytrivinyltriphenyltrisiloxane and benzoyl peroxide and subsequently polymerized to a thermoset copolymer.