Patent ID: 9731491
Date: 2017-08-15
CPC Classifications: B32B,Y10T

Claim:
1. A method for producing a melamine decorative board comprising: providing a decorative layer comprising a resin-impregnated patterned paper; impregnating a whitish fibrous base material with a resin liquid and to form a plurality of sheets of resin-impregnated core paper, said resin liquid comprising 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; drying the plurality of sheets of resin-impregnated core paper to form a core layer; impregnating a fibrous base material with a varnish comprising a condensate of melamine and formaldehyde, wherein an ash content of the fibrous base material is 8-10% by weight, to form an impregnated fibrous base material for a backside paper which backside paper is different from said resin-impregnated patterned paper, wherein said varnish does not include said divalent polyalkylene glycol or said derivative thereof, or said tri- or more valent polyalkylene glycol polyvalent ether; drying said impregnated fibrous base material for the backside paper to form a backside layer; stacking said decorative layer, said core layer, and said backside layer such that said core layer is disposed between said decorative layer and said backside layer; and applying heat and pressure to said stacked decorative layer, core layer, and backside layer to form said melamine decorative board; wherein said core layer exhibits, when measured independently, a dimensional stability in accordance with Japanese Industrial Standard (JIS) K 6902 after application of said heat and pressure of from 0.1% or more to 0.3% or less in a longitudinal direction and from 0.3% or more to 0.5% or less in a lateral direction, and wherein a total light transmittance in accordance with JIS K 7136 of an item formed only of the impregnated fibrous base material for the backside paper is 30% or less.