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US 4,354,979 AGranted
Preparation of aliphatic isocyanates
AssigneeBASF SE
InventorsVolker Schwendemann, Dietrich Mangold
Life of this patent
Estimating the term…
Abstract
Organic isocyanates are prepared by thermal decomposition of N,N'-disubstituted allophanic acid esters in an organic carbonate at from 150.degree. to 400.degree. C. The isocyanates obtainable by this process are valuable starting materials for the preparation of crop protection agents, pesticides, dyes, synthetic resins, plastics, textile waterproofing agents, detergents, bleaching agents and adhesives.
Claims5
A process for the preparation of an aliphatic isocyanate of the formula
- R.sup.1 -NCO I
- where R.sup.1 is an aliphatic radical, by thermal cleavage, wherein an N,N'-disubstituted allophanic acid ester of the formula ##STR4## where the R.sup.1 may be identical or different and have the above meanings and R.sup.2 is an aromatic radical derived from an unsubstituted or substituted phenol which is distillable at below 250.degree. C. is thermally cleaved at from 150.degree. to 400.degree. C. in the presence of a diester of carbonic acid, of the formula ##STR5## where the R.sup.3 's may be identical or different and each is an aliphatic, cycloaliphatic, araliphatic or aromatic radical, or the R.sup.3 's together are an unsubstituted or substituted alkylene or phenylene radical.
Dependencies are inferred from the claim text.