| abstract |
A copolycondensation of a phenol, a naphthol and formaldehyde proceeds smoothly in the presence of an acid and a metallic element selected from the group consisting of transition metallic elements and metallic elements of Group IIa, Group IIIa, Group IVa, Group Va and Group VIa of the Periodic Table, and a naphthol-modified phenolic resin which has a large molecular weight and does not gel is obtained. |