PURPOSE: To obtain decorative sheet, which is excellent in the dimensions of decorative veneer so as not to develop crack therein, by a method wherein veneer impregnatingly filled with shaping filler is pasted onto base material and then the filler is subjected to water-insolubilizing treatment.
CONSTITUTION: Urea-impregnated veneer, which is obtained by immersing white ocka veneer in 20 per cent urea solution for five minutes, is bonded through aqueous vinyl urethane adhesive onto lauan plywood base material. Further, polyurethane sanding sealer is applied onto the surface of the veneer and polyurethane top coating paint is applied onto the sealer. The urea in the veneer reacts with the urea infiltrated from both the sides of the veneer and is turned into polymeric compound through the reaction with the adhesive and the free isocyanate compound (MD 1) in the hardener in the sealer, resulting in turning into water-insoluble urea.
KAWABATA BUNJI
TERAYAMA KENICHI
ARAKAWA SUMIYO
