Phenylenediamine derivative, production method thereof and antioxidant for rubber using it as effective constituent

Abstract

A phenylenediamine derivative represented by following formula (I) or (II): wherein R 1 and R 2 each represents a hydrogen atom, a lower alkyl group, or a lower alkoxy group; R 3 represents a hydrogen atom or a methyl group, R 4 represents a methyl group or an ethyl group; and n and m each is 1, 2, or 3; wherein R 1 and R 2 each represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, or a cyano group; and n and m each is 1, 2, or 3, is disclosed. These phenylenediamine derivatives are effectively used as antioxidants for rubbers, which scarcely cause vanishing by evaporation or a thermal denaturation even under a high-temperature condition of 150° C. or higher.

What is claimed is:  
     
         1 . A phenylenediamine derivative represented by the following formula (I):  
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  each represents a hydrogen atom, a lower alkyl group, or a lower alkoxy group; R 3  represents a hydrogen atom or a methyl group; R 4  represents a methyl group or an ethyl group; and n and m each represents 1, 2, or 3.  
       
     
     
         2 . The phenylenediamine derivative of  claim 1 , wherein the number average molecular weight Mn of the phenylenediamine derivative is at least about 400 and the weight loss thereof when the compound is allowed to stand in hot air of 175° C. f or 40 hours is about 30% or less.  
     
     
         3 . A method of producing a phenylenediamine derivative represented by the following formula (I):  
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  each represents a hydrogen atom, a lower alkyl group, or a lower alkoxy group; R 3  represents a hydrogen atom or a methyl group; R 4  represents a methyl group or an ethyl group; and n and m each represents 1, 2, or 3,  
         which comprises reacting N,N′-dipheny-1,4-phenylenediamine and a styrene derivative represented by the the following formula:  
         
           
             
             
                 
                 
             
           
         
         wherein R 1  and R 2  each represents a hydrogen atom, a lower alkyl group, or a lower alkoxy group; and R 3  and R 4  each represents a hydrogen atom or a methyl group,  
         in the presence of a protonic acid catalyst.  
       
     
     
         4 . An antioxidant for rubber comprising a phenylenediamine derivative represented by the following formula (I):  
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  each represents a hydrogen atom, a lower alkyl group, or a lower alkoxy group; R 3  represents a hydrogen atom or a methyl group; R 4  represents a methyl group or an ethyl group; and n and m each represents 1, 2, or 3.  
       
     
     
         5 . A phenylenediamine derivative represented by the following formula (II):  
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  each represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, or a cyano group; and n and m each represents 1, 2, or 3.  
       
     
     
         6 . The phenylenediamine derivative of  claim 5 , wherein the number average molecular weight of the phenylenediamine derivative is at least about 450 and the weight loss thereof when the compound is allowed to stand in hot air of 175° C. is about 40% or less.  
     
     
         7 . A method of producing a phenylenediamine derivative represented by the following formula (II):  
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  each represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, or a cyano group; and n and m each represents 1, 2, or 3,  
         which comprises reacting N, -diphenyl-1,4-phenylenediammine and a benzoyl halide represented by the the following formula:  
         
           
             
             
                 
                 
             
           
         
         wherein R 1  and R 2  each represents a hydrogen, a lower alkyl group, a lower alkoxy group, or a cyano group; and X represents a halogen atom.  
       
     
     
         8 . An antioxidant for rubber comprising a phenylenediamine derivative represented by following formula (II):  
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  each represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, or a cyano group; and n and m each represents 1, 2, or 3.  
       
     
     
         9 . An anti oxidant, for acrylic rubber comprising a mixture of (A) an antioxidant compound represented by the following formula:  
       
         
           
           
               
               
           
         
         wherein R 1  represents a hydrogen atom or an alkyl group; R 2  represents an alkyl group or a cumyl group; and R 3  represents an alkyl group,  
         and (B) an antioxidant compound represented by the following formula:  
         
           
             
             
                 
                 
             
           
         
       
     
     
         10 . An antioxidant for acrylic rubber of  claim 9 , wherein the antioxidant compound (A) and the antioxidant compound (B) are used in the ratio of from 4 to 40% by weight and from 96 to 60% by weight, respectively.