GB528479A - A process for the manufacture of resinous condensation products - Google Patents

Abstract

528,479. Urea-formaldehyde condensation products. BECK, KOLLER & CO. (ENGLAND), Ltd., (Hodgins, T. S., and Hovey, A. G.). May 8, 1939, Nos. 13736 and 28137. [Class 2 (iii)] Urea-formaldehyde condensation products, suitable for use in preparing coating compositions, are prepared by condensing aqueous formaldehyde with urea in the presence of butanol, undersuperatmospheric pressures reflux, a temperature of 100‹C. and initial pH between 8 and 9, in presence of an alkaline-reacting catalyst, and thereafter further condensing by heating in an acid medium, until the nitrogen content is approximately 18 per cent., at least 2¢ mols. formaldehyde and 3 mols. butanol per mol. urea being employed. In examples : (1) urea 24 gram mols. aqueous formaldehyde, 7.2 gram mols. butanol and 8 gram mols. urea, together with a little ammonia, giving pH between 8 and 9 are heated to 100‹C. in one hour and maintained for about 1 hour under 2 atmospheres pressure ; further butanol, making a total of 24 gram molecules is then added and the reaction completed in an acid medium either under vacuum or atmospheric pressure (2) urea, aqueous formaldehyde and butanol in molecular ratios 1:3:3 are worked up with potassium hydroxide, under reflux, then acidified with phosphoric acid and the reaction completed by distilling off the azeotrope of butanol and water. The products are soluble in alcohols, ketones, aromatic hydrocarbons and tolerate straight-chain aliphatic hydrocarbons, and are compatible with oil modified alkyd resins. Specifications 256,248, 261,029, 309,849, 327,673, [all in Class 2 (iii)], 344,626, 442,054, 484,200, 491,857, 494,700 and 511,087 U.S.A. Specification 2,108,113 and Re-issue 19463, and German Specification 403,645 are referred to.