| 摘要 |
PURPOSE:The titled resin excellent in persistent stability, high in yields in curing a resin at high temperatures and capable of providing a cured product of good flexibility and water resistance, obtained by reacting urea with a phenol and an aldehyde in the presence of a basic catalyst. CONSTITUTION:35-95pts.wt. urea (U) is reacted with 65-5pts.wt. phenol (P) in the presence of a basic catalyst, and an aldehyde (A) is added to the reaction system. The reaction mixture is reacted till the molar ratio of A/(U+P) reaches 0.8-2.2 to obtain a water-soluble, phenol-modified resin having a water expansion ratio at 25 deg.C which is at least three times by volume as high as the content of nonvolatile matter (JIS-K-6909) of this resin. EFFECT:A water-soluble, phenol-modified urea resin having high yields in curing resin at high temperatures >=150 deg.C and excellent persistent stability can be obtained. USE:Binder, adhesives, or the like for organic materials and inorganic materials.
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