NAPHTHOL-CONTAINING NOVOLAC RESIN, NAPHTHOL NOVOLAC EPOXY RESIN, EPOXY RESIN COMPOSITION, AND CURED PRODUCT THEREOF

摘要

PROBLEM TO BE SOLVED: To obtain inexpensively a lowly viscous naphthol-containing novolac resin which is a starting material for epoxy resins and can be used also as a curing agent by using a hydroxy carboxylic acid as the condensation reaction catalyst. SOLUTION: This resin is obtained by using a hydroxy carboxylic acid having an alcoholic hydroxyl group and a carboxyl group in the molecule as a catalyst for condensing a naphthol or a mixture thereof with a phenol with an aldehyde and is represented by the formula (wherein k, i and j are each an integer of 0-6; x, y and z are each an integer of 1 or 2; n is a positive number of 0.1-20 on the average; (h+i×n+j) Rs, which are independent of each other, are hydrogen atoms, 1-10C alkyls, etc.; n ys in the repeating units may be the same or different from each other). The ratio of the number of the benzene rings of the entire resin to the number of the naphthalene rings of the entire resin is 10 or below.