Improvements in or relating to the treatment of drying or semi-drying oils to produce substances for use in paint, enamel, lacquer or like protective coating compositions

摘要

A base for a paint, lacquer, enamel, or like is obtained by blowing a drying or semidrying oil at relatively low temperatures until not less than 60 per cent is a liquid insoluble in petroleum ether but soluble in ethyl ether, discontinuing the oxidation prior to substantial coagulation, and removing unoxidized and non-hardening constituents by a selective solvent, e.g. petroleum ether or naphtha. A resin and/or an acidic agent which is at most slightly volatile under the conditions and which retards coagulation are preferably present. Specified oils treated are linseed, perilla, and soya. Resins mentioned are rosin, and ester gum, fused Congo, Congo ester, paracumaron, and phenol-formaldehyde resins. Acidic agents include one or more of: maleic acid or anhydride, and malic, succinic, tartaric, salicylic, acetyl-salicylic, sulphanilic, anthranilic, benzoic, citric, picric, oxalic, lactic, and boric acids. In an example: 1 lb. of ester gum resin is dissolved in 3 lb. of linseed oil, 0,5 per cent of maleic acid or anhydride added, preferably as a solution in acetone, and the mixture, with or without 0,04 per cent of cobalt linoleate or other drier, is blown at 80 DEG C. for 25--30 hrs. until a sample just fails to dissolve completely in ethyl ether. After cooling the mixture is extracted 3 times with 3--5 vol. of petroleum ether, and freed from residual solvent by warming in vacuo. The product is conveniently put up as a 60--80 per cent solution in toluene, xylene, coal naphtha, or butyl acetate. Typical coating-compositions are prepared by mixing 50 lb of base, 35 lb. of toluene, 14,5 lb. of naphtha, and 0,5 lb. of cobalt linoleate; or 35 lb. of base, 25 lb. of toluene, 23,5 lb. of naphtha, 8 lb. of lithopone, 8 lb. of titanium dioxide, and 0,5 lb. of cobalt linoleate. They may be applied by spraying, dipping, or brushing, and the film dried and baked at 220--240 DEG F., for 60--100 min. The base may also be compounded with nitro-cellulose or other cellulose esters.