Polymerization initiator, curable composition, dental material, and preparation kit for curable composition

Abstract

Provided is a polymerization initiator, which has an excellent curing rate and is an alternative to a polymerization initiator system using a benzoyl peroxide-aromatic amine compound, a curable composition containing the polymerization initiator, a dental material and dental filler material containing the composition, and a kit for preparing the curable composition. The polymerization initiator contains one or more compounds (A) selected from the group consisting of a pyrazolidinedione compound and/or pyrazolidine(di)thione compound (A1), a salt (A2) of the compound (A1), and a malonate compound (A3).

1 . A polymerization initiator comprising one or more compounds (A) selected from the group consisting of a pyrazolidinedione compound and/or pyrazolidine(di)thione compound (A1), a salt (A2) of the compound (A1), and a malonate compound (A3). 
     
     
         2 . The polymerization initiator according to  claim 1 , wherein the compound (A) is one or more compounds selected from the group consisting of a pyrazolidinedione compound and/or pyrazolidine(di)thione compound (A1), and a salt (A2) of the compound (A1). 
     
     
         3 . The polymerization initiator according to  claim 1 , wherein the pyrazolidinedione compound and/or pyrazolidine(di)thione compound (A1) is represented by the following general formula (1), 
       
         
           
           
               
               
           
         
         wherein R 1  is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and the hydrocarbon group may contain a hetero atom, 
         R 2  and R 3  are independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and the hydrocarbon group may contain a hetero atom, 
         X represents an oxygen atom or a sulfur atom, and R 2  and R 3  may be directly bonded to each other to form a cyclic hydrocarbon group having 3 to 12 carbon atoms. 
       
     
     
         4 . The polymerization initiator according to  claim 1 , which comprises a transition metal compound (B). 
     
     
         5 . The polymerization initiator according to  claim 4 , wherein the transition metal compound (B) is a copper compound. 
     
     
         6 . A curable composition comprising the polymerization initiator as defined  claim 1  and a polymerizable monomer (C). 
     
     
         7 . The curable composition according to  claim 6 , comprising at least one selected from the group consisting of a peroxide (D), a filler (E), a reducing agent (F), and an aqueous solvent (G). 
     
     
         8 . The curable composition according to  claim 6 , which comprises a photopolymerization initiator (H). 
     
     
         9 . A dental material comprising the curable composition as defined in  claim 6 . 
     
     
         10 . A dental filler material comprising the curable composition as defined in  claim 6 . 
     
     
         11 . A separately packed polymerization initiator comprising a first pack containing the compound (A) as defined in  claim 1  and a second pack containing a transition metal compound (B). 
     
     
         12 . A kit for preparing a curable composition, comprising a first pack containing the compound (A) as defined in  claim 1 , and a second pack containing a transition metal compound (B), wherein at least one of the first pack and the second pack contains a polymerizable monomer (C).