| 摘要 |
PURPOSE:To obtain the title phenolic resin which is rapid-curing and excellent in the heat resistance and water resistance of a cured product, by precondensing a phenol with an alkehyde, removing a free phenol and a binuclear component and condensing the precondensate by dehydration. CONSTITUTION:A precondensate is obtained by reacting a phenol comprising phenol or/and cresol with an aldehyde (e.g., form-aldehyde or paraformaldehyde) in the presence of a catalyst. A free phenol and a binuclear component are removed from the precondensation mixture, and the precondensate is condensed by dehydration in a vacuum to obtain the purpose novolak phenol resin. the obtained phenolic resin has a number-average MW (x) of a resin component except a free phenol of 500-700 and a free phenol content of 1-5wt% and a binuclear component content (y) in the range of y<=-0.015x+13.5wt%.
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