JPS6313443B

PURPOSE:A modifying agent, consisting of a reaction product between an isocyanate compound and a phenolic compound, and capable of imparting flexibility to a phenolic resin and improving the physical properties, e.g. low temperature processability, etc. CONSTITUTION:A modifying agent obtained by reacting an isocyanate compound which is a reaction product of a liquid polymer having active hydrogen groups, e.g. hydroxyl groups, at the molecular ends and 300-25,000, preferably 500- 10,000 number-average molecular weight, e.g. liquid polybutadiene, with a polyisocyanate compound, e.g. tolylene diisocyanate, with a phenolic compound, e.g. phenol or cresol. The resultant modifiying agent in an amount of 0.5-35wt%, preferably 5-30wt%, based on a phenolic resin is added thereto.