Process for the preparation of liquid mixtures of compounds having isocyanate groups
AssigneeBayer Aktiengesellschaft
InventorsIngo Stemmler, Hanns-Peter Muller, Kuno Wagner
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Abstract
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.degree. to 250.degree. 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.
Claims6
A process for the production of a mixture of isocyanate group containing compounds which mixture is liquid at room temperature and is suitable as an isocyanate component in the production of polyurethane plastic materials comprising reacting at a temperature between 100.degree. and 250.degree. C.
- (a) up to 70 parts by weight polyurethane with,
- (b) 100 parts by weight polyisocyanate having a melting or softening point below 50.degree. C. in the presence of
- (c) a catalytic quantity of a compound selected from 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 subgroups of the Periodic System of elements.
Dependencies are inferred from the claim text.