GB493810A - Improvements in or relating to the preparation of resinous coating compositions - Google Patents

Abstract

Resinous coating - compositions, forming stable solutions in hydrocarbon solvents, are produced by condensing a mixture of urea, formaldehyde and the fatty acid of a drying or semi-drying oil in an alcoholic solvent, distilling off the whole or part of the alcoholic solvent and diluting the residue with a hydrocarbon solvent such as xylol or solvent naphtha. A small proportion of maleic anhydride is preferably added before the distillation step. The alcoholic solvent is preferably sparingly soluble in water. Natural resins, e.g. colophony, esterified colophony or fused copal, or synthetic resins, e.g. phenolic or oil-modified glycerol-phthalic anhydride resins, may be added in the first part of the process. The product may be blended with plasticizers, e.g. thionyl and dibutyl phthalates, blown castor oil, &c. In an example, urea, paraformaldehyde and fatty acids from soya bean oil are dissolved in butyl alcohol and heated to 100-101 DEG C. for 1 hour, after which a small proportion of maleic anhydride is added and the greater part of the butyl alcohol is distilled off under vacuum; the residue is diluted with xylol and filtered. In a second example, linseed oil fatty acids are employed and the product is diluted with solvent naphtha.