Phenolic moulding compsns. contg. pre-treated wood filler - giving increased water resistance and hardening rate

摘要

Press moulding powders are based on phenol-formaldehyde resin, and contain, as filler, ground wood which has been treated at b.pt. with an aq soln. of phenol and HCHO in presence of HCl, wt. ratio of phenol: HCHO: water: HCl: ground wood being 0.15-0.8:0.045-0.864:6-15:0.0435-0.1086:1. The compsns. contain 15-45 pts. phenolic resin, 47.5-75 pts. filler, 7-9 pts. hardener, 0.5-1 pt. accelerator and 0.6-0.9 pt. lubricant. Used for moulding components for the electrical, radio and machine tool industries. The compsns. give high water-resistance and hardening rate, with good plasticity in processing. Heat resistance is increased (up to 182 degrees C). Extended duration of the plastic-viscous state at 170 degrees C allows use for injection moulding. Wood waste, e.g. sawdust, wood chips, and effluent solns. from phenol and HCHO prodn. can be used to make the filler, which can replace expensive phenol-wood flour.