| 摘要 |
PURPOSE: To obtain an amino resin adhesive composition excellent in water resistance by mixing an amino resin with a modified PVA containing a specified amount of 4C or lowerα-olefin units. CONSTITUTION: A vinyl ester (e.g. vinyl acetate) is copolymerized with a 4C or lowerα-olefin (e.g. ethylene) to form a copolymer containing 1-10mol%α- olefin units, and this copolymer is hydrolyzed to obtain a PVA modified with the 4C or lowerα-olefin and having a degree of polymerization of about 100-8000 and a degree of hydrolysis of about 50mol% or above. This PVA is mixed with an aldehyde (e.g. formaldehyde), water and at least one amino compound selected from among urea, melamine, dicyandiamide, etc., and further mixed with about 0.1-15wt.%, based on the amino resin component, above modified PVA, and the resulting mixture is mixed with an aqueous NaOH solution to adjust its pH and condensed under heating to form an amino resin. This resin is mixed with a filler and a thickener to obtain an amino resin adhesive composition excellent in water resistance.
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