Patent ID: 6946421

Claim:
A latent catalyst composed of a phosphonium borate represented by the general formula (3): wherein R 9 , R 10 , R 11 and R 12 may be the same as or different from one another and each is a monovalent, organic group having an aromatic ring or a heterocyclic ring or a monovalent, aliphatic group and is bonded to the phosphorus atom to form a P—C bond; Z 3 is an organic group bonding to the substituents Y 5 and Y 6 ; Y 5 and Y 6 may be the same as or different from each other and each is a group formed when a monovalent proton-donating substituent has liberated a proton; the substituents Y 5 and Y 6 in the same molecule are bonded to the boron atom to form a chelate structure; X 5 and X 6 may be the same as or different from each other and each is a group formed when a proton donor having at least one proton capable of being liberated out of the molecule has liberated one proton, or is a monovalent, organic group having an aromatic ring or a heterocyclic ring or a monovalent, aliphatic group; HY 5 Z 3 Y 6 H which is the proton donor before the ligand Y 5 Z 3 Y 6 of boron is formed by the liberation of the protons and HX 5 and HX 6 which are the proton donors in the case where each of X 5 and X 6 is a group formed when a proton donor having at least one proton capable of being liberated out of the molecule has liberated one proton, satisfying the condition that when 1 g of each of to proton donors is mixed with 50 g of a purified water and the resulting mixture is subjected to pressure cooker treatment at 125° C. for 20 hours in a pressure cooker vessel, to electrical conductivity of the extraction water thus obtained becomes not more than 1,000 μs/cm.