GB293872A - Manufacture of artificial products - Google Patents

Abstract

293,872. Kappeler, H. July 14, 1927, [Convention date]. Samples furnished. Urea-furfurol condensation products. - Black compositions resembling ebonite are produced by condensing furfurol with urea and conducting at least a part of the reaction in the presence of an acid or acid salt. The furfurol mav be mixed with other aldehydes and the urea with other amino compounds; furfuramide or derivatives and condensation products of urea may also be used. The reaction may proceed in stages, furfurol and urea being first brought together without a catalyst or in presence of a neutral or alkaline substance, and then converted into the final product by addition of an acid electrolyte or ammonium salt. Colouring matters, filling materials and softening agents may be added, e.g. mineral pigments, organic dyestuffs, sawdust, cork powder, leather powder, heavy spar, asbestos, glycerine, camphor, naphthalene, ketones, phenols, amines or their condensation products with, for instance, formaldehyde. The compositions may be after-treated with an impregnating agent, whilst the mixture made for the purpose of the reaction may be used for impregnating wood, cellulose, &c., before the reaction is completed. According to examples, (1) approximately equimolecular proportions of urea and furfurol are mixed in the presence of aqueous hydrochloric acid and the liquid poured into moulds which are preferably cooled to modify the ensuing reaction: finallv the mass is heated to 100‹ C., forming a solid, black composition which can be rendered tougher by boiling with an impregnating agent such as linseed oil or furfurol; the water may be replaced wholly or in part by alcohol, glycerine or acetone, and the acid by another mineral acid, an organic acid or an acid salt; (2) the urea of the preceding example may be replaced by a mixture of urea with aniline or toluidine or by a salt of urea such as the hydrochloride, whilst a mixture of furfurol or formaldehyde may replace the furfurol; (3) urea and furfurol or furfuramide are heated together to 100‹ C., if desired in the presence of alcohol or water; the yellowish product is further heated after addition of hydrochloric acid or a salt such as ammonium chloride for conversion with the black final material; (4) urea and furfurol are heated to 100-120‹ C. in presence of a base such as caustic soda or a basic salt: the resulting soft, soluble resin is then condensed bv means of hvdrochloric acid into the black composition. Specification 256,711 is referred to.