Control of procedures for formation of water-immiscible thermosetting phenol-formaldehyde resins

Claim 1

A process for the production of a water-immiscible thermosetting phenol-formaldehyde resin characterized by a large proportion of the linkages between benzene rings being benzyl ether linkages located ortho to the phenolic hydroxyl group, by reaction of formaldehyde with phenol at a mole ratio of at least 1:1 in an essentially aqueous reaction medium containing at least one water-soluble metal carboxylate catalyst for the reaction, said catalyst having the formula (C n H 2n+1 COO) x M where n is an integer from 0 to 10, x is greater than 1 and M is a metal having an atomic number of from 21 to 30, which comprises conducting exothermic methylolation of phenol by formaldehyde at an elevated temperature in excess of about 60° C., thereafter conducting polymerization of the methylolated phenol by heating the reaction medium resulting from the methylolation reaction at a temperature in excess of about 90° C. for a time insufficient to cause separation of a water-immiscible resin phase from the aqueous phase at that temperature, cooling the reaction medium to cause separation of a low viscosity water-immiscible resin phase from the aqueous phase, said low viscosity resin phase being characterized by a large proportion of the linkages between benzene rings being benzyl ether linkages located ortho to the phenolic hydroxyl groups, recovering the low viscosity resin phase from the aqueous phase, heating said recovered low viscosity resin at a temperature below its thermosetting temperature for a sufficient time to increase the viscosity thereof to a desired higher value, and recovering the higher viscosity thermosetting phenolformaldehyde resin so formed.