POWDER COMPOSITION FOR BONDING WOOD

摘要

PURPOSE:To provide a powder compsn. for bonding wood, which is stable over a long period of time and has excellent initial bond strength and dry bond strength, containing methylol melamine powder and an unsaponified ethylene/ vinyl acetate copolymer powder. CONSTITUTION:1.5-6mol of formaldehyde is added to 1mol of melamine. The mixture is reacted at a pH of 7 or above by heating and the reaction mixture is spray-dried to prepare a powder of methylol melamine or its precondensate. The titled powder composition for bonding wood contains 100pts.wt. said powder and 20-200pts.wt. unsaponified ethylene/vinyl acetate copolymer powder. Said copolymer powder can be obtd. by emulsion-polymerizing vinyl acetate under ethylene pressure in the presence of polyvinyl alcohol in an aq. medium.