| 摘要 |
PURPOSE:To obtain the titled resin, containing polysiloxanediol and polyoxytetramethylene glycol, etc., in a specific proportion as soft segment and capable of providing films having excellent surface slipperiness, light fastness, hydrolytic resistance, etc., and improved moisture permeability as well as water repellency. CONSTITUTION:A polyurethane resin, constituted of soft segments consisting of (A) a polysiloxanediol having 600-3,000 average molecular weight, (B) polyoxytetramethlylene glycol having 800-2,200 average molecular weight and, if necessary, (C) other diols and hard segments consisting of (D) an aliphatic diisocyanate and (E) an aliphatic diamine and containing 3-50wt.% component (A) and the component (B) in an amount of 0.6 based on the component (A). For example, the above-mentioned resin is obtained by initially carrying out reaction at 1/1.3-1/4.5 ratio of OH groups of the soft segment to NCO groups of the a component (D) to prepare a prepolymer and then extending the chain with the component (E).
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