Latent catalyst, thermosetting resin composition comprising the catalyst, epoxy resin molding material comprising the catalyst, and semiconductor device

A latent catalyst composed of a phosphonium borate represented by the general formula (2):

• 12
• wherein R5, R6, R7 and R8 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;
• Z1 is an organic group bonding to Y1 and Y2;
• Z2 is an organic group bonding to Y3 and Y4;
• each of Y1 and Y2 is a group formed when a monovalent, proton-donating substituent has liberated a proton and the substituents Y1 and Y2 in the same molecule are bonded to the boron atom to form a chelate structure;
• each of Y3 and Y4 is a group formed when a monovalent, proton-donating substituent has liberated a proton and the substituents Y3 and Y4 are bonded to the boron atom to form a chelate structure;
• Z1 and Z2 may be the same as or different from each other and also Y1, Y2, Y3 and Y4 may be the same as or different from one another;
• HY1Z1Y2H and HY3Z2Y4H which are the proton donors before the ligands Y1Z1Y2 and Y3Z2Y4 of boron are formed by liberation of the respective protons satisfying the condition that when 1 g of each of the proton donors is mixed with 50 g of purified water and the resulting mixture is subjected to pressure cooker treatment at 125° C. for 20 hours in a pressure cooker vessel, the electrical conductivity of the extraction water thus obtained becomes not more than 1,000 μS/cm.

A latent catalyst composed of a phosphonium borate represented by the general formula (3):

• 13
• wherein R9, R10, R11 and R12 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;
• Z3 is an organic group bonding to the substituents Y5 and Y6;
• Y5 and Y6 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 Y5 and Y6 in the same molecule are bonded to the boron atom to form a chelate structure;
• X5 and X6 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;
• HY5Z3Y6H which is the proton donor before the ligand Y5Z3Y6 of boron is formed by the liberation of the protons and HX5 and HX6 which are the proton donors in the case where each of X5 and X6 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 the proton donors is mixed with 50 g of purified water and the resulting mixture is subjected to pressure cooker treatment at 125° C. for 20 hours in a pressure cooker vessel, the electrical conductivity of the extraction water thus obtained becomes not more than 1,000 μS/cm.

A latent catalyst having a structure in which the recurring unit is a phosphonium borate consisting of a monovalent cation portion in which four groups are bonded to the phosphorus atom and a monovalent anion portion in which four groups are bonded to the boron atom and at least two of the recurring unit are connected through at least one of the four groups bonding to the boron atom, provided that the group through which the recurring units are connected is a group formed when one proton donor has liberated at least two protons and the group may be composed of the same kind or different kinds;

• the groups bonding to the phosphorus atom 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;
• among the groups bonding to the boron atom, those which do not participate in the connection of the recurring units are each 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 a monovalent, organic group having an aromatic ring or a heterocyclic ring or a monovalent, aliphatic group and they may be the same as or different from one another;
• the proton donors from which the groups bonding to the boron atom result satisfying the condition that when 1 g of each of the proton donors is mixed with 50 g of purified water and the resulting mixture is subjected to pressure cooker treatment at 125° C. for 20 hours in a pressure cooker vessel, the electrical conductivity of the extraction water thus obtained becomes not more than 1,000 μS/cm.