Aqueous paint composition of baking-drying type

Abstract

To propose a baking-drying water damping paint composition from which heavy film-thickness damping paint films can be obtained, heavy film-thickness damping paint films in which an inorganic filler is filled into the resinous component of paints to higher extent, and which are free from the occurrence of cracks and swelling in the paint films when the paint films are baked and dried. The composition comprises a water emulsion including at least one first granular resin selected from the group consisting of styrene-butadiene copolymers, acrylic ester copolymers and ethylene-vinyl acetate copolymers whose glass transition temperature is from 0 to 20° C. and gel ratio is from 60 to 80%, and an inorganic filler in an amount of 200 parts by weight or more with respect to 100 parts by weight of said first granular resin. By using water emulsion particles whose gel ratio is controlled in the specific range, it is possible to obtain cured paint films which are free from the occurrence of cracks and swelling in the paint films and which exhibit a high damping effect stably even when the inorganic filler is filled to higher extent and the paint films are further dried at ordinary baking temperatures.

1 . A baking-drying water damping paint composition, comprising: 
 a water emulsion including at least one first granular resin selected from the group consisting of styrene-butadiene copolymers, acrylic ester copolymers and ethylene-vinyl acetate copolymers whose glass transition temperature is from 0 to 20° C. and gel ratio is from 60 to 80%; and    an inorganic filler in an amount of 200 parts by weight or more with respect to 100 parts by weight of said first granular resin.    
     
     
         2 . The baking-drying water damping paint composition set forth in  claim 1 , wherein a drying temperature of a paint film falls in a range of from 70 to 160° C.  
     
     
         3 . The baking-drying water damping paint composition set forth in  claim 1  comprising said inorganic filler in an amount of 600 parts by weight or less with respect to 100 parts by weight of said first granular resin.  
     
     
         4 . The baking-drying water damping paint composition set forth in  claim 1 , wherein said inorganic filler is at least one member selected from the group consisting of calcium carbonate, talc, diatomaceous earth, barium sulfate, zeolite, magnesium carbonate and mica.  
     
     
         5 . The baking-drying water damping paint composition set forth in  claim 4 , wherein said inorganic filler has an average particle diameter of 50 μm or less.  
     
     
         6 . The baking-drying water damping paint composition set forth in  claim 1 , wherein said inorganic filler includes inorganic short fibers whose fibrous length is from 100 μm to 1 mm.  
     
     
         7 . A baking-drying water damping paint composition, comprising: 
 a water emulsion including at least one first granular resin selected from the group consisting of styrene-butadiene copolymers, acrylic ester copolymers and ethylene-vinyl acetate copolymers whose glass transition temperature is from 0 to 20° C. and gel ratio is from 60 to 80%, and at least one second granular resin selected from the group consisting of styrene-butadiene copolymers, acrylic ester copolymers and ethylene-vinyl acetate copolymers whose glass transition temperature is from 25 to 60° C.; and    an inorganic filler in an amount of 200 parts by weight or more with respect to the sum of said first granular resin and said second granular resin taken as 100 parts by weight.    
     
     
         8 . The baking-drying water damping paint composition set forth in  claim 7 , wherein a drying temperature of a paint film falls in a range of from 70 to 160° C.  
     
     
         9 . The baking-drying water damping paint composition set forth in  claim 7  comprising said inorganic filler in an amount of 600 parts by weight or less with respect to the sum of said first granular resin and said second granular resin taken as 100 parts by weight.  
     
     
         10 . The baking-drying water damping paint composition set forth in  claim 7 , wherein said inorganic filler is at least one member selected from the group consisting of calcium carbonate, talc, diatomaceous earth, barium sulfate, zeolite, magnesium carbonate and mica.  
     
     
         11 . The baking-drying water damping paint composition set forth in  claim 10 , wherein said inorganic filler has an average particle diameter of 50 μm or less.  
     
     
         12 . The baking-drying water damping paint composition set forth in  claim 7 , wherein said inorganic filler includes inorganic short fibers whose fibrous length is from 100 μm to 1 mm.  
     
     
         13 . The baking-drying water damping paint composition set forth in  claim 7 , wherein said first granular resin is included in an amount of from 40 to 85 parts by weight with respect to the sum of said first granular resin and said second granular resin taken as 100 parts by weight.  
     
     
         14 . The baking-drying water damping paint composition set forth in  claim 7 , wherein said first granular resin is included in an amount of from 50 to 85 parts by weight with respect to the sum of said first granular resin and said second granular resin taken as 100 parts by weight.