GB778026A - Improvements in or relating to the production of paint vehicle bases - Google Patents

Abstract

A paint vehicle is obtained by heating a glycidyl ether of a polyhydric phenol having at least one -OH group and from 1-2 epoxy groups per mol. with a fatty oil having an iodine number of 70-220 at 75 F. until a clear solution is obtained and then heating the product with 5-15 per cent by weight of a dicarboxylic acid or anhydride until incipient gelation occurs whereupon the product is thinned with a hydrocarbon thinner. The product obtained in the first stage may be heated with 3-20 per cent by weight of a monocarboxylic acid to reduce the iodine number by about 50 per cent. The glycidyl ether has preferably 3-10 -OH groups and 1.4-1.9 epoxy groups per mol. and the heating with the fatty oil is carried out in presence of an alcoholysis catalyst. The glycidyl ethers are prepared by reaction of epichlorhydrin with the usual dihydric phenols, e.g. resorcinol, hydroquinone and polynuclear phenols. A table is given of the Durrans' m.ps., hydroxyl, epoxy and esterification values of the products used. Fatty oils specified are soybean, linseed, corn, cottonseed, hemp, kapok, herring, perilla, poppy, pilchard, menhaden, mustard, peanut, rape, sardine, safflower, sesame, oiticia, walnut, tung, dehydrated castor and heat bodied linseed oils. Polyhydric alcohols, e.g. pentaerythritol, are preferably present during the action with the fatty oil. The monocarboxylic acids used have at least 6 C atoms, e.g. the free acid of the aforementioned oils; other suitable acids are caproic, caprylic, 2-ethylhexoic, lauric, palmitic, stearic, oleic, benzoic, p-ter.-butylbenzoic, naphthenic acids, cinnamic, hydrogenated rosin. The dicarboxylic acids specified for the second stage are malonic, succinic, sebacic, glutaric, azelaic, sebacic, maleic, phthalic, tetrahydrophthalic, hexahydrophthalic, diglycolic, dimerized drying oil fatty acids, dimerized rosin, Diels-Alder adducts of maleic anhydride with diolefines, e.g. terpenes and cyclopentadiene, petrex acids. In examples (1) a polyether obtained from epichlorhydrin and bisphenol is reacted at 555 DEG F. with a soybean oil having an iodine no. of 130. The product is further reacted with soybean acids and adipic acids until gelation starts whereupon a solvent consisting of 75 per cent paraffin and 25 per cent naphthenes is added. The base obtained is used to make up pigment mixtures of (a) titanium dioxide calcium carbonate and aluminium stearate; (b) red iron oxide, black iron oxide, calcium carbonate and aluminium stearate. Specification 737,272 is referred to.