暖房下において合板から放散するホルムアルデヒドの気中濃度について

Abstract

Tests on formaldehyde liberation from lauan plywood made with each six type typical wood adhesives were carried out at 20°, 50°, and 70°C for 300days. The amount of the liberated formaldehyde in air was quantitatively determined by a gas detector (Gastec No. 91, GASTEC CORPORATION, TOKYO, JAPAN) at selected intervals. The effects of duration of storage, temperature of dry-heat exposure, and kind of adhesive on formaldehyde liberation were determined. The factors that have the greatest effect on formaldehyde liberation from the lauan plywoods were kind of resin adhesive and temperature of dry-heat exposure. The amount of liberated formaldehyde from the resin adhesives was found to increase in the order of resorcinol-formaldehyde, <phenol-formaldehyde, <phenol-resorcinol-formaldehyde, <polyvinyl acetate cross-linked, <melamine-urea-formaldehyde, <and urea-formaldehyde resin. The large amounts of released formladehyde vapours from the plywood made with urea-formaldehyde resin adhesive in dry-heated air are injurious to health. The amount of liberated formaldehyde from the lauan plywoods can be reduced by prolonged storage and elevated temperature of dry-heat exposure. Gas-liquid chromatgraphic analysis of 2, 4-dinitrophenylhydrazones of the released formaldehyde and carbonyl compounds from the plywoods were also investigated.