GB256711A - A new synthetic resin product - Google Patents

Abstract

256,711. Fleet, W. F., Potter, H. V., and Damard Lacquer Co., Ltd. May 15, 1925. Samples furnished. Urea-phenol-aldehyde condensation products.- Resinous compounds are prepared by condensing urea or a substitution product with aldehydes in the presence of an amount of phenol or a homologue which varies between one-third and five times the quantity of the urea. Thiourea is mentioned as a substitution product of urea, whilst formaldehyde, acetaldehyde, and furfuraldehyde are specified as aldehydes. The best results are obtained bv condensing 33<1>/3- 100 parts by weight of phenol with 20-100 parts by weight of urea and 150-313 parts by volume of a 40 per cent solution of formaldehyde. In any case, the volume of 40 per cent solution of formaldehyde employed should be X+2.5Y, where X and Y represent the weight of phenol and urea respectively employed. An accelerator such as ammonia may be present. The reacting materials are heated together, preferably at the boiling point of the mixture, for some time, and the product then dehydrated either by boiling in an open pan or by evaporation in vacuo. After dehydration in an open pan, the viscous product is soluble in such solvents as o-toluidine, pyridine, aniline, tetrachlorethane, and ethyl lactate, and can be used either in this form or in the bard resinous form in varnish manufacture or for the preparation of moulding mixtures. After dehydration in vacuo, the resulting syrup is soluble in alcohol, acetone, butyl alcohol, and methylated spirit. Either of the dehydration products can be hardened in the usual manner. Examples are given. The Provisional Specification refers also to cresol as a starting material and to caustic soda or mineral acids as accelerators.