Process of making cold molding compositions

Abstract

Abstract 555,449. Synthetic resin moulding powders. BRITISH THOMSON-HOUSTON CO., Ltd. Jan. 27, 1942, No. 1117. Convention date, Jan. 29, 1941. [Class 2 (iii)] A moulding powder suitable for cold or hot moulding is obtained by adding together a major proportion of a neutral liquid phenolic resin and a minor proportion of liquid glue, mixing the materials at room temperature sufficiently to produce a viscous but not rubbery mass, coating, as by pouring, the resultant liquid composition on to a fibrous filler at room temperature before the composition gets to a rubbery mass and agitating, disintegrating and drying the resultant mass. The neutral liquid phenolic resin is obtained by reacting phenol and formaldehyde in presence of an alkaline earth hydroxide as catalyst and thereafter precipitating the catalyst by gaseous carbon dioxide and removing it. Specified fillers include asbestos, silex, wood flour, cotton flock, paper flock and dried paper pulp. Colouring matters may also be added. Examples are given of the preparation of a phenolic resin, using barium hydroxide as catalyst, and of a moulding powder including a filler mixture of asbestos, silex and wood flour together with pigments ; such powder may be cold moulded and the moulded parts hardened by treatment for 20 hours at a temperature gradually increasing from 140-260‹F., or it may be hot moulded at 200‹F. Such moulding composition is suitable for the production of roller skate wheels ; by omitting the wood flour, products suitable for electric insulating materials may be obtained.

Inventors

• 👤 William R Heineman

Bibliographic Details