A PROCESS FOR PREPARING A MICROCELLULAR POLYURETHANE ELASTOMER FROM A SOFT-SEGMENT ISOCYANATE-TERMINATED PREPOLYMER AND MICROCELLULAR POLYURETHANE ELASTOMER OBTAINED THEREBY

摘要

the invention relates to a process for preparing polymers of polyurethane by reacting an isocyanate composition and the weight of the isocyanate component is combined between 180 and 300, and which contains at least 50% by weight of the prepolymer.an active substance containing hydrogen in the presence of water, which is not less than 50 mol% of the total requirements for the swelling.the prepolymer is obtained by reacting a polyisocyanate with a molar excess of at least 70% by weight of 4,4 '- methylene diphu00e9nylisocyanate with reactive isocyanate composition containing (a) a diol or triol branched with molecular weight ranges from 60 to 3000.and (b) a polyol or mixtures of the polyoxialkylu00e8ne whose functionality is between 2 and 4, and of which the molecular weight is between 3 and 12, in which the parts by weight of (a): (b) ranging between 0.01 and 0.25 to 1: 1.