PURPOSE: To obtain the above overlay layer excellent in transparency by a method wherein the overlay layer to be provided on wooden board is made of specified powdered phenolic resin intercalative paper.
CONSTITUTION: Powdered phenolic resin composing powdered phenolic resin intercallative paper is hot-melt-setting resin, which is produced by simultaneously carrying out the addition reaction and condensation reaction of phenolics and formaldehyde in the presence of excessive hydrochloric acid catalyst, and has methylol group in molecule, a weight average molecular weight of 3,500 or more and a gelling time of 3min or longer. The intercalative paper contains 50-90vol.% of powdered phenolic resin. Further, fibrous base material is made of pulp. The intercalative paper contains at least 10vol.% of wooden pulp, which is beaten to the extent so as to obtain the freeness of 500-50ml. Furthermore, the intercalative paper contains 0-20vol.% of synthetic resin and 10-30vol.% of powdered inorganic substance. The overlay layer concerned is produced by heating the intercalative paper put on wooden board under pressure so as to melt and harden the powdered phenolic resin and melt and bond the resin to the surface of the wooden board.
KIMURA MEGUMI
TAKAGUCHI SHINICHIRO
Next Patent: LONG BOARD IN WHICH WOODEN CHIP BUNDLES ARE OBLIQUELY CROSSED, BONDED AND LAMINATED IN MULTIPLE LAYE...