GB377587A - Improvements in or relating to resinous condensation products and coating compositions - Google Patents

Abstract

Resinous products are obtained by reacting together, in the presence of an alkaline catalyst, an oxidized drying oil, about an equal amount of a phenol or hydrogenated phenol, a natural resin, and an aldehyde, the molecular ratio of aldehyde to phenol or hydrogenated phenol lying between about 1 and 0.25. As the phenolic component there may be used ordinary phenol, a cresol, cresylic acid, a naphthol, or cyclohexanol; the oxidized drying oil may be oxidized or blown tung oil, linseed oil, perilla oil, soya bean oil, or fish oil; the natural resin may be colophony or Manila copal; the aldehyde may be formaldehyde, acetaldehyde, or benzaldehyde; the catalyst may be ammonia or a caustic alkali or alkali metal carbonate. In an example, oxidized linseed oil is dissolved in the warm in an equal amount of commercial phenol, and the solution is treated with commercial resin and formaldehyde solution (about 0.7 mol. calculated on the phenol), with addition of a little ammonia; the mixture is heated under reflux and the water then distilled off. The products are soluble in hydrocarbon oils and drying oils, and are useful as varnish bases, preferably in association with plasticizers such as tricresyl phosphate or castor oil, and driers such as manganese dioxide or resinates. The Specification refers to prior methods, for making resins of similar properties, comprising (1) condensing phenol and formaldehyde in about equimolecular amounts in the presence of oxidized drying oils and an alkaline catalyst; (2) condensing a phenol with 0.5-1 mol. of an aldehyde in the presence of oxidized drying oils (other than tung oil) and an alkaline catalyst.