| 摘要 |
PURPOSE:To obtain a binder for ceramic molding of high strength, high dispersibility and good workability by containing a water-soluble polyurethane including the oxyethylene units derived from a prescribed water-soluble polyoxyalkylene polyol. CONSTITUTION:Ethylene oxide is homopolymerized and/or ethylene oxide and propylene oxide are block- or random-copolymerized to give a water-soluble polyoxyalkylene polyol (A) of 2,000 to 25,000 number-average molecular weight. Then, one or more organic polyisocyanates are selected from 4,4'- diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate (B). Then, the component (A) is allowed to react with the component (B) to produce a binder for ceramic molding comprising a water-soluble polyurethane (C) of 10,000 to 300,000 weight-average molecular weight, more than 80wt.% of content of oxyethylene units and 0.1 to 5wt.% of urethane group concentration. |
