| 摘要 |
Waste polyurethane materials are made re-usable by converting them to liquid mixtures. Such liquid mixtures are made by reacting up to 70 parts by weight of polyurethane with a low-melting polyisocyanate at 100 DEG to 250 DEG C. in the presence of a catalyst. Suitable catalysts include the acid and neutral salts, phenolates, enolates and alcoholates of a metal of the 3rd, 4th or 5th Main Group or 1st, 2nd, 4th, 7th or 8th subgroup of the Periodic System of elements. The thus-produced mixtures contain isocyanates and are suitable as an isocyanate component in the production of polyurethane plastic materials.
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