Polyvinyl acetal resin, slurry composition prepared therefrom, ceramic green sheet, and multilayer ceramic capacitor

Abstract

According to the present invention, provided is a polyvinyl acetal resin capable of obtaining a ceramic green sheet that has sufficient mechanical strength, in which the dimensional change in the storage of ceramic green sheet is small, and the delamination hardly occurs in the delipidation. The present invention relates to a polyvinyl acetal resin that has a degree of polymerization of 200 or more to 6000 or less, a content percentage of vinylester unit of 0.01 to 30 mol %, a degree of acetalization of 55 to 83 mol %, and a structural unit represented by Chemical formula (1): in a molecule.

1 . A polyvinyl acetal resin, comprising a structural unit of formula (1): 
       
         
           
           
               
               
           
         
       
       in a molecule, 
       wherein the polyvinyl acetal resin has a degree of polymerization of from 200 to 6000, a content percentage of vinylester unit of from 0.01 to 30 mol %, and a degree of acetalization of from 55 to 83 mol %. 
     
     
         2 . The polyvinyl acetal resin according to  claim 1 , wherein the degree of polymerization is from 1500 to 4500. 
     
     
         3 . The polyvinyl acetal resin according to  claim 1 , wherein the polyvinyl acetal resin is obtained by a process comprising acetalizing a polyvinyl alcohol resin with aldehyde comprising 3-methylbutanal. 
     
     
         4 . The polyvinyl acetal resin according to  claim 1 , further comprising a structural unit of formula (2): 
       
         
           
           
               
               
           
         
         formula (3): 
       
       
         
           
           
               
               
           
         
         or both in the molecule. 
       
     
     
         5 . The polyvinyl acetal resin according to  claim 1 , wherein the polyvinyl acetal resin comprises the structural unit of formula (1) in a content of at least 30 mol % relative to a total molar amount of acetalized structural units. 
     
     
         6 . A slurry composition, comprising:
 the polyvinyl acetal resin according to  claim 1 ;   a ceramic powder; and   an organic solvent.   
     
     
         7 . A ceramic green sheet, obtained by a process comprising producing the ceramic green sheet from the slurry composition according to  claim 6 . 
     
     
         8 . A conductive paste, comprising:
 the polyvinyl acetal resin according to  claim 1 ; and   a conductive powder.   
     
     
         9 . A laminated ceramic capacitor, obtained by a process comprising producing the laminated ceramic capacitor from the ceramic green sheet according to  claim 7 . 
     
     
         10 . A laminated ceramic capacitor, obtained by a process comprising producing the laminated ceramic capacitor from the conductive paste according to  claim 8 . 
     
     
         11 . The polyvinyl acetal resin according to  claim 2 , wherein the degree of polymerization is from 2000 to 3500. 
     
     
         12 . The polyvinyl acetal resin according to  claim 1 , wherein the content percentage of vinylester unit is from 0.5 to 20 mol %. 
     
     
         13 . The polyvinyl acetal resin according to  claim 1 , wherein the degree of acetalization is from 65 to 80 mol %. 
     
     
         14 . The polyvinyl acetal resin according to  claim 1 , obtained by a process comprising acetalizing a polyvinyl alcohol resin with aldehyde comprising acetaldehyde. 
     
     
         15 . The polyvinyl acetal resin according to  claim 1 , obtained by a process comprising acetalizing a polyvinyl alcohol resin with aldehyde comprising butyraldehyde. 
     
     
         16 . The polyvinyl acetal resin according to  claim 3 , wherein the polyvinyl acetal resin comprises the structural unit acetylized by 3-methylbutanal of formula (1) in a content of at least 50 mol % relative to the total molar amount of acetalized structural units.