GB156675A - Manufacture of plastic materials - Google Patents

Abstract

An initial liquid phenol-formaldehyde condensation product is prepared by the reaction of phenols (phenol, cresols, naphthols) with anhydrous polymers of formaldehyde (para-formaldehyde, trioxymethylene) in the presence or absence of alkaline catalysts; this liquid product is converted into the final insoluble infusible product by addition of liquid organic acids (lactic, acetic, formic, ricinoleic, sulphoricinoleic, &c.), or solid organic acids such as oxalic, tartaric, citric, gallic, or tannic acid, dissolved in a liquid organic acid, together with small amounts of a mineral acid (hydrochloric, oxyacids of sulphur or phosphorus, boric &c.); the conversion takes place in the cold, or more rapidly on heating. The initial liquid product with the acids added can be used as a varnish, or for glueing together lamin of wood, wood and fabric, &c. Fillers, such as pumice, sand, glass, emery, asbestos, insoluble mineral bodies, paper, pulp, sawdust, cotton, &c. may be incorporated in the mass, or its properties varied by addition of gelatine, glue, naphthalene, rubber &c. Vessels resisting chemical reagents can be made from the final product, or lamin or plates thereof can be glued on surfaces by means of the initial product varnish.