METHOD FOR PRODUCING NOVOLAK TYPE PHENOL RESIN

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a novolak type phenol resin by which the novolak type phenol resin with a controlled content of a monomer of phenols and a controlled dispersion ratio can be produced in high yield. SOLUTION: The method for producing the novolak type phenol resin comprises a step of reacting the phenols with paraformaldehyde in the presence of phosphoric acids in an amount of≥5 to <25 pts. mass based on 100 pts. mass of the phenols in a heterogeneous system. COPYRIGHT: (C)2005,JPO&NCIPI