PHENOL-FORMALDEHYDE RESINS

摘要

Resins for use in making resin-coated granules are made by preparing a novolak resin from a phenol and formaldehyde in the presence of lactose and/or galactose, using an acid catalyst. Melt-coating the resin with an amine curing agent on to particulate refractory material gives resin-coated granules which can be moulded to make foundry moulds. The lactose and/or galactose can replace part of the phenol conventionally employed in preparing novolak resins and avoid the need forplasticisers.