PURPOSE: To make working life adequate and to make it possible to release the clamping force in a short time in the bonding of woods by mixing a first liquid comprising a specific polyol component as a main component with a second liquid comprising an isocyanate component as a main component just before the use.
CONSTITUTION: Pentaerythritol (i) is subjected to addition polymerization with propylene oxide (ii) to produce a polyol (a) having a hydroxyl number of 380-620. Separately, 2,2-bis(4-hydroxyphenyl)propane is subjected to addition polymerization with the component (ii) to produce a polyol (b) having a hydroxyl number of 190-325. The component (a) is mixed with the component (b) in a weight ratio of 39-90/70-10 and a curing catalyst, thereby producing a first liquid comprising the polyol component as a main component. This liquid is mixed with a second liquid comprising, as a main component, an isocyanate component containing a diphenylmethane diisocyanate modified with carbodiimide and/or a polymeric diphenylmethane diisocyanate having an acidity of 0.1-0.5 wt.% in terms of HC1 just before the use.
IWAKURA MITSUHARU
NISHIBE KOJI
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