PREPOLYMER COMPOSITION COMPRISING AROMATIC AND ALIPHATIC DIISOCYANATES, LOW MONOOL CONTENT PROPYLENE OXIDE-BASED ETHER POLYOL, SHORT DIOL, NEUTRALIZER AND UV STABILIZER, WATER DISPERSIVE POLYURETHANE ELASTOMER PREPARED BY USING THE COMPOSITION, AND ITS PREPARATION METHOD

摘要

PURPOSE: Provided are a prepolymer composition for the preparation of a water dispersive polyurethane elastomer which is improved in mechanical properties and is free from smell or yellowing, a water dispersive polyurethane elastomer prepared by using the composition and its preparation method. CONSTITUTION: The prepolymer composition comprises an aromatic diisocyanate and an aliphatic diisocyanate in a ratio of 1:1 to 0.1:1 by weight, wherein a polyol with a weight average molecular weight of 200-300 is added in a ratio of 1:0.8 to 1:1.2 by equivalence to react with the diisocyanate, 2-5 wt% of a short diol is added to give a water dispersion, a neutralizer is added in an equal ratio to neutralize the short diol, and 0.1-10 wt% of a UV stabilizer is added to inhibit yellowing. Preferably the polyol is a propylene oxide-based ether polyol whose level of monool content is 1/2 - 1/10 of that of the already-existing propylene oxide-based ether polyol; and the short diol is a carboxyl group or a tertiary amine group-containing alcohol.