Continuous prodn. of phenolic novolak or resol moulding compsn. - by prepn. of water emulsion resin, cooling and mixing with additives

摘要

Continuous prodn. of moulding compsns. based on phenolic novolak or resol resins involves polycondensation of phenol (homologues) with aq. HCHO soln. at 140-180 degrees C and 9-25 at. in the presence of a 10-15% soln. of an acid or alkaline catalyst in HCHO soln. to give a water emulsion resin. This is cooled to 70-140 degrees C and mixed with filler, hardener and lubricant and opt. solvent or mineral additive at 70-160 degrees C and 20-30 at. until a homogeneous compsn. is obtd., which is then cooled gradually from 160 to 80 degrees C at 90-600 torr vacuum. Continuous operation is possible. The emulsion resin is heat treated at 130-140 degrees C and 60-600 torr vacuum and/or cooled to 70-95 degrees C before mixing with the additives.