Melamine Decorative Board

Abstract

Provided is a melamine decorative board having a milky-white core layer and less warpage. When the melamine decorative board is bonded onto a base plate such as a plywood, a particle board, and a steel board, a color tone of the base plate does not appear through to a decorative layer. Stacked and thermal-pressure-formed are: a resin-impregnated patterned paper as the decorative layer; multiple sheets of a resin-impregnated core paper, as the core layer, produced by impregnating a whitish fibrous base material with a resin liquid including: a condensate of melamine and formaldehyde, and a divalent polyalkylene glycol or a derivative thereof, or a tri- or more valent polyalkylene glycol polyvalent ether, and drying the whitish fibrous base material; and a resin-impregnated backside paper, as a backside layer, produced by impregnating a fibrous base material with a condensate of melamine and formaldehyde and drying the fibrous base material.

1 . A melamine decorative board produced by stacking a decorative layer, a core layer, and a backside layer, and then forming the layers under heat and pressure, wherein
 the decorative layer is a resin-impregnated patterned paper,   the core layer is a plurality of sheets of a resin-impregnated core paper produced by impregnating a whitish fibrous base material with a resin liquid including: a condensate of melamine and formaldehyde; and a divalent polyalkylene glycol or a derivative thereof, or a tri- or more valent polyalkylene glycol polyvalent ether, and then drying the whitish fibrous base material, and   the backside layer is a resin-impregnated backside paper produced by impregnating a fibrous base material with a condensate of melamine and formaldehyde, and then drying the fibrous base material.   
     
     
         2 . The melamine decorative board according to  claim 1 , wherein a dimensional stability in accordance with JIS K 6902 of the decorative layer after formed under heat and pressure is greater than or equivalent to that of the backside layer. 
     
     
         3 . The melamine decorative board according to  claim 1 , wherein an ash content of the fibrous base material used as the backside layer is 2-10% by weight. 
     
     
         4 . The melamine decorative board according to  claim 1 , wherein a total light transmittance in accordance with JIS K 7136 of only the core layer after formed under heat and pressure is 30% or less. 
     
     
         5 . The melamine decorative board according to  claim 1 , wherein an amount of the divalent polyalkylene glycol or the derivative thereof added is 9-20 parts by weight per 100 parts by weight of a solid content of the condensate. 
     
     
         6 . The melamine decorative board according to  claim 1 , wherein an amount of the tri- or more valent polyalkylene glycol polyvalent ether added is 13-30 parts by weight per 100 parts by weight of a solid content of the condensate. 
     
     
         7 . The melamine decorative board according to  claim 2 , wherein an ash content of the fibrous base material used as the backside layer is 2-10% by weight. 
     
     
         8 . The melamine decorative board according to  claim 2 , wherein a total light transmittance in accordance with JIS K 7136 of only the core layer after formed under heat and pressure is 30% or less.