GB280520A - - Google Patents

Abstract

280,520. Bakelite Corporation, (Assignees of Bender, H. L.). Nov. 10, 1926, [Convention date]. Condensation products of formaldehyde with phenol and urea, thiourea, or toluene p-sulphonamide.-Resinous products are obtained by causing a phenol to react with more than one molecular proportion of formaldehyde, and then combining at least a part of the excess of formaldehyde with a non-phenolic substance having resin-forming properties; instead of formaldehyde, its polymers or equivalent substances, such as hexamethylenetetramine, may be used. In an example, phenol and an excess of formaldehyde solution are heated in presence of sodium carbonate or other basic catalyst until separation of water occurs, and the heating is continued, preferably under reduced pressure, until the water is evaporated. The product is then treated with urea and with sufficient lactic, boric, phosphoric or other acid to render the mass acid, and is finally heated again. The product may be rendered infusible and insoluble by further heating and may be used in making moulding mixtures, or alternatively it may be dissolved in alcohol or other solvent, the addition of which may precede or follow the addition of the urea, and used as a varnish. Instead of urea there may be used thiourea or toluene p-sulphonamide. The Specification, as open to inspection under Sect. 91 (3) (a) states that instead of urea there may be used homologues of urea or urea derivatives other than thiourea. This subject-matter does not appear in the Specification as accepted.