NOVOLAK TYPE PHENOL RESIN

摘要

PROBLEM TO BE SOLVED: To obtain a high-ortho novolak type phenol resin having a few branched structures and methylene linkages bonded to the phenol nucleus at the o-positions at a high level. SOLUTION: This high-ortho novolak type phenol resin is obtained by reacting trifunctional phenols with a polyacetal resin at a high temperature under a high pressure without a catalyst and is characterized as having <=16% number of bonds in a branched structural part (a state in which three methylene linkages are bonded to one phenol nucleus) based on the total number of bonds in a bonding mode of the phenol nucleus to the methylene groups measured by a 13C-NMR spectral method. The O/P ratio is preferably >=3.