NOVOLAK TYPE RESIN, EPOXY RESIN, EPOXY RESIN COMPOSITION AND ITS CURED MATERIAL

摘要

PROBLEM TO BE SOLVED: To obtain a nonvolak type resin having a specific structure and capable of providing a cured product excellent in water resistance and mechanical strength by reaction with a curing agent for epoxy resins. ;SOLUTION: This novolak type resin has a structure of formula I [(n) is 0-10 as average value; R is a 1-4C alkyl]. The resin can be obtained by subjecting, e.g. (A) a compound of formula II to condensation reaction with (B) formaldehyde in an amount of 0.01-0.95 mol based on 1 mol component A in the presence of (C) an acid catalyst in an amount of 0.1-30 wt.% based on the component A at 40-180°C for 1-10 hr. A compound of formula III, formula IV, etc., is preferably used as the component A. p-Toluenesulfonic acid, sulfuric acid, hydrochloric acid, etc., is preferably used as the component C. After reaction, preferably, the reaction mixture is subjected to water-washing treatment until pH of washing solution of the reaction mixture becomes 3-7 and a solvent is distilled away under heating and reduced pressure so as to concentrate the product.;COPYRIGHT: (C)1999,JPO