GB416661A - Process for the production of artificial resins - Google Patents

Abstract

Condensation products of urea, thiourea and derivatives thereof are sulphurized or vulcanized with salts, including polysulphides, of the alkali and alkaline earth metals containing sulphur in an -S-S- linkage with or without oxygen atoms the compounds being added as such or formed in situ. Suitable compounds include polysulphides, thiosulphates, polythionates and substances capable of being transformed thereto in the presence of, for example, oxidizing agents such as sodium p - toluenechlorsulphamide, sodium hypochlorite and persulphate. The reaction may take place in the warm, in the presence of alkali, during or after the resin forming condensation and in the presence of rubber vulcanization accelerators such as sodium xanthate. The products may be worked up into lacquers containing spirit, oil or cellulose and into hard compositions. In examples: (1) urea and potassium xanthate are dissolved in aqueous formaldehyde and treated with sodium polysulphide and borax to obtain a resin; (2) the product obtained by dissolving urea and potassium xanthate in formaldehyde and treatment with sodium tetrathionate and borax is absorbed into cellulose and the product dried and ground to yield a moulding powder; (3) urea is dissolved in formaldehyde and treated with barium polysulphide to yield a resin; (4) urea is dissolved in formaldehyde, and heated with potassium xanthate, caustic soda and borax the solution being covered with a suspension of sulphur in petroleum ether to yield a resin; (5) urea is heated with potassium xanthate and formaldehyde and then treated with sodium sulphide and sodium p-toluenechloramide in the presence of borax to yield, after coagulation with acid, a resin. The Specification as open to inspection under Sect. 91 refers to the sulphurization of synthetic resins in general with sulphur in -S-S- linkage, and includes an example illustrating the use of diuram sulphide. This subject-matter does not appear in the Specification as accepted.ALSO:Condensation products of urea, thiourea and derivatives thereof that have been vulcanized by means of salts of alkali and alkaline earth metals containing sulphur in an -S-S- linkage may be used in plastic compositions. In an example, (2) the product obtained by dissolving urea and potassium xanthate in formaldehyde and treatment with sodium tetrathionate in the presence of borax is absorbed into cellulose and the product, after drying, ground to a moulding powder.