| abstract |
As the blocking agent dissociation catalyst, a catalyst containing a quaternary ammonium salt represented by the following general formula (1) is used. Wherein R 1 to R 3 are aliphatic hydrocarbon groups having 1 to 8 carbon atoms or aromatic hydrocarbon groups having 6 to 14 carbon atoms, R 4 is an aliphatic hydrocarbon group having 9 to 20 carbon atoms, X is a phosphoric acid group, a boric acid group, A is an integer in the range of 1 to 3, and b is an integer in the range of 1 to 3. The term " a " means a group selected from the group consisting of an alkyl group, |