An object of the invention is to provide a preparation process of a latent catalyst that can gives a latent catalyst, which can exert an excellent catalytic activity at the time of molding and therefore, can provide a resin composition having good curing property, fluidity and storage stability, in a short time in a high yield without mixing in ionic impurities. The present invention relates to a preparation process of a phosphonium silicate latent catalyst, comprising reacting (A) a proton donor represented by the following formula (1):
[Chemical Formula 1]
HY1-Z1-Y2H (1)
[wherein Y1 and Y2 may be the same or different and each represents a group resulting from a proton donating substituent through release of a proton, Z1 represents a substituted or unsubstituted organic group which bonds to the proton donating substituents Y1H and Y2H, and two substituents Y1 and Y2 in the same molecule are capable of bonding to a silicon atom to form a chelate structure], (B) a trialkoxysilane compound and (D) a phosphonium salt compound represented by the following formula (2):
[wherein R1, R2, R3 and R4 may be the same or different and each represents an organic group having a substituted or unsubstituted, aromatic or heterocyclic ring or represents a substituted or unsubstituted aliphatic group and X− represents a halide ion, a hydroxide ion or an anion resulting from a proton donating group through release of a proton], wherein the reaction is carried out in the presence of (C) a metal alkoxide compound.