TRANSPARENT, STEAM STERILIZABLE, NONCELLULAR POLYURETHANE COMPOSITIONS, A PROCESS FOR THEIR PREPARATION AND THEIR USE ESPECIALLY FOR MEDICINAL ARTICLES

摘要

TRANSPARENT, STEAM STERILIZABLE, NONCELLULAR POLYURETHANE COMPOSITIONS, A PROCESS FOR THEIR PREPARATION AND THEIR USE ESPECIALLY FOR MEDICINAL ARTICLES The present invention relates to transparent essentially non-cellular polyurethane casting compositions that are sterilizable with superheated steam which are prepared by reacting: A) modified diphenylmethane diisocyanates (A) liquid at 23.degree.C obtained by reacting A1) 4,4'-diphenylmethane diisocyanate or A2) 2,4'-diphenylmethane diisocyanate or A3) a diphenylmethane diisocyanate mixture with A4) at least one polyoxypropylene polyol and/or A5) at least one polyoxypropylene polyoxyethylene polyol containing 1 to 80 weight percent of ethylene oxide units whereby (A4) and (A5) have a functionality of 4 to 8 and a hydroxyl number of 150 to 500 and are obtained while using sucrose and/or preferably sorbitol as initiator molecules A6) a mixture of (A4) and/or (A5) and at least one polyoxypropylene polyol and/or polyoxyethylene polyol initiated with glycerine and/or trimethylolpropane in a NCO:OH group ratio of 2.5:1 to 15:1 with B) at least one compound having at least reactive hydrogen atoms which preferably contains no primary, secondary or tertiary amino groups in bonded form in the presence of or absence of C) catalysts. The present invention also relates to a process for the preparation of polyurethane casting compositions and their use for medical-technical articles.