FORFARANDE FOR FRAMSTELLNING AV ETT VERMEHERDBART FENOLFORMALDEHYDHARTS

摘要

A thermosetting phenol-formaldehyde resin is prepared by reaction of phenol with formaldehyde in a ratio higher than 1.7:1. The infrared spectrum of this resin exhibits high absorption peaks at 1230, 1060 and 1030 cm<-1>. The absorption at 1060 cm<-1> is decreased by at least 5 % and the absorption at 1030 cm<-1> is increased by at least 5 % by reacting the resin with a strong acid. The resin thus obtained can be employed for the manufacture of particle boards.