| 摘要 |
The instant invention is directed to a process for the production of a light fast, transparent polyurethane elastomer comprising reacting: (A) from 90 to 50% by weight, based on the polyurethane solids content, of a compound having a molecular weight of from 400 to 10,000 which has at least two Zerewitinoff active hydrogen atoms; (B) from 50 to 10% by weight, based on the polyurethane solids content, of an aliphatic and/or alicyclic polyisocyanate; and (C) from 0 to 20% by weight, based on the polyurethane solids content, of a chain-lengthening agent having a molecular weight of from 60 to 400; in the presence of: (D) catalysts for the isocyanate polyaddition reaction, the improvement wherein said catalysts, component (D), is a catalyst combination of: (a) an alkali metal hydroxide and/or alkaline earth metal hydroxide; and (b) an organometallic compound selected from the group consisting of the acetyl acetonate of iron, C1-C8 alcoholates, phenolates, enolates and/or acetyl acetonates of metals of the 4th main group or sulfur-containing compounds of metals of the 4th main group, in which compounds the sulfur is directly attached to the metal atom.
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