Phenolic resin and method of producing the same

Abstract

A phenolic resin obtainable by reacting a dihydroxy compound of the following formula (1) with a phenolic compound, wherein the dihydroxy compound is partially dehydrated.

1 . A phenolic resin obtained by reacting a dihydroxy compound of the following formula (1) with a phenolic compound,  
     
       
         
         
             
             
         
       
       wherein, Ar represents an aromatic group having 6 to 20 carbon atoms; R 1  to R 4  represent each independently a hydrogen atom, alkyl group having 1 to 20 carbon atoms, cycloalkyl group having 5 to 20 carbon atoms or aralkyl group having 7 to 20 carbon atoms; R 1  and R 3  do not simultaneously represent a hydrogen atom, and R 2  and R 4  do not simultaneously represent a hydrogen atom: and  
       wherein the peak area corresponding to compound (a) is in the range from 90 to 100% based on the total peak area corresponding to compounds (a) and (b), when the phenolic resin is measured by a high performance liquid chromatography method using an ultraviolet detector at a detection wavelength set at 220 nm,  
       compound (a) has a molecular structure in which structural units derived from the dihydroxy compound and structural units derived from the phenolic compound are alternately bonded, and as the molecular end, structural units derived from the phenolic compound are bonded; and compound (a) has a molecular weight obtained by subtracting the molecular weight of 4 mol of water molecule from the total molecular weight of 2 mol of the dihydroxy compound and 3 mol of the phenolic compound,  
       compound (b) has a molecular structure in which two of the dihydroxy compounds are mutually bonded, and as the molecular end, structural units derived from the phenolic compound are bonded, and compound (b) has a molecular weight obtained by subtracting the molecular weight of 4 mol of water molecule from the total molecular weight of 2 mol of the dihydroxy compound and 2 mol of the phenolic compound.  
     
   
   
       2 . The phenolic resin according to  claim 1  wherein the dihydroxy compound is 1,3-bis(2-hydroxy-2-propyl)benzene or 1,4-bis(2-hydroxy-2-propyl)benzene.  
   
   
       3 . The phenolic resin according to  claim 1  wherein the phenolic compound is phenol or cresol.  
   
   
       4 . (canceled)  
   
   
       5 . (canceled)  
   
   
       6 . An epoxy resin obtained by glycidyl-etherifying the phenolic resin of  claim 1 .  
   
   
       7 . An epoxy resin composition obtained by compounding the following (A) to (C): 
 (A) an epoxy resin of  claim 6 ,    (B) a hardener having phenolic hydroxyl groups, and    (C) an inorganic filler.    
   
   
       8 . A resin insulation type semiconductor apparatus obtained by hardening the epoxy resin composition according to  claim 7 .  
   
   
       9 . An epoxy resin obtained by glycidyl-etherifying the phenolic resin of  claim 2 .  
   
   
       10 . An epoxy resin obtained by glycidyl-etherifying the phenolic resin of  claim 3 .  
   
   
       11 . An epoxy resin composition obtained by compounding the following (A) to (C): 
 (A) an epoxy resin of  claim 9 ,    (B) a hardener having phenolic hydroxyl groups, and    (C) an inorganic filler.    
   
   
       12 . An epoxy resin composition obtained by compounding the following (A) to (C): 
 (A) an epoxy resin of  claim 10 ,    (B) a hardener having phenolic hydroxyl groups, and    (C) an inorganic filler.