PURPOSE:To obtain non-corrosive foamed phenolic resin moldings by the foam- hardening of an uncured resol type phenol-formaldehyde resin liquid with a powdered acid acceptor, incorporated therein, having a water-soluble polymer coating. CONSTITUTION:A hydrous uncured resol type phenol-formaldehyde resin liquid with a powdered acid acceptor, incorporated therein, having a water-soluble polymer coating is heated in the presence of an acid curing agent and a foaming agent to cause foam-hardening. Acid acceptors to be used include powdered metals and powdered metal compounds, in which powdered metalloid metals are preferable and powdered metallic zinc is most desirable. The particle size of the powder is preferably 5-150mu. A polyvinyl alcohol or methyl cellulose is most desirable as the water-soluble polymer.
展开▼
