GB691010A - Improvements in and relating to thixotropic compositions - Google Patents

Abstract

A thixotropic composition comprises an unsaturated alkyd resin, a powdered filler selected from catalpo clay, diatomaceous earth, flint, silica, talc, china clay, titanium dioxide, barytes and tripoli, and a surface-active wetting agent for the resin and filler, e.g. highly reactive polar polyether compounds (Intral), aryl alkyl polyether alcohols, polymerized ethylene amide condensation products of the formula R1-CO-OR2(OR2)xOH (where R1 is a hydrophilic aliphatic chain, R2 a short hydrocarbon chain, e.g. C2H4, and X is 1, 2 or 3), and ethylene, diethylene and polyethylene glycols, glycerine and sorbitan mono-oleate, with a small amount of water. Suitable alkyd resins are the reaction products of polyhydric alcohols, e.g. ethylene, diethylene, triethylene, propylene, tri-, tetra-and penta-methylene glycols, glycerol and pentaerythritol with unsaturated polycarboxylic acids, e.g. maleic, fumaric and itaconic, or the decarboxylated half-ester of glyceryl triricinoleate with an unsaturated a ,b -polycarboxylic acid, which may be modified with monohydric alcohols or saturated polycarboxylic acids, e.g. succinic, adipic, sebacic and phthalic. There may be present also polymerizable esters of unsaturated monohydric alcohols and polycarboxylic or polybasic inorganic acids, e.g. diallyl phthalate, succinate, maleate, fumarate, itaconate and chlorophthalate, and triallyl phosphate; copolymerizable esters of monohydric alcohols and unsaturated polycarboxylic acids, e.g. dioctyl and dibenzyl itaconates, diethyl and dibenzyl fumarates; methyl, ethyl, propyl, isopropyl, butyl, isobutyl and allyl acrylates and methacrylates; styrene, vinyl acetate; a vinyl acetate-chloride copolymer; catalysts, e.g. benzoyl peroxide, t.-butyl hydroperoxide, t.-butyl perbenzoate and diperphthalate; and plasticizers, e.g. tricresyl phosphate. Examples describe the use as alkyl resins of glyceryl tris (cyclohexyl maleate), decarboxylated castor oil maleate and diethylene glycol maleate. The compositions may be heat polymerized to an infusible, insoluble state, e.g. in situ as impregnants for electrical coils.