No.7（2004）15.Modification of amino resin adhesives using emulsion-type isocyanate

Kensuke KAWARADA, Takahiko IIDA, Kenji OTSUKA, Akira HASEGAWA

In order to modify the bond properties of amino resin adhesives, especially urea-formaldehyde (UF) resin adhesive, an emulsion-type isocyanate compound (EMDI) was added to UF resin synthesized to a molar ratio of formaldehyde to urea which was 1.2 (F/U=1.2). Tensile shear strength tests concerning the plywood bonded with UF resin and/or EMDI were conducted. Moreover, mechanical properties and emission of carbonyl compounds of particleboard were estimated. The bond performance of the plywood was enhanced while increasing the EMDI in UF resin. The bond strength of plywood used in ammonium peroxodisulfate as a hardener was higher than that of the plywood used in ammonium chloride. The mechanical properties of particleboards were modified with an increase of EMDI in UF resin. The amount of formaldehyde emission from plywood and particleboard was satisfied the criteria stipulated in Japanese national standards.

Keywords
Urea-formaldehyde resin, Emulsion-type isocyanate, Bond strength, Particleboard, Emission of carbonyl compounds 

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