PROCESS FOR PRODUCING UREA-MODIFIED, HIGHLY REACTIVE PHENOLIC RESINS USEFUL AS BONDING AGENTS FOR CENTER-LAYER PARTICLES IN THE MANUFACTURE OF PARTICLEBOARD

摘要

Urea-modified, highly reactive phenolic resins usefulas center-layer bonding agents in the manufacture ofparticleboard are provided by condensing phenol andformaldehyde until shortly before gelation takes placesuch that, after addition of urea, relativelylow-alkaline, urea-modified phenolic resins are obtainedwhich may optionally be stored and to which, shortlybefore processing them into glues for center-layerparticles, alkali is added in sufficient quantities toensure rapid cross-linking of the phenolic resin.