Patent · US Expired

Process for the preparation of aromatic carbamates and isocyanates

US4415745A · kind A · utility

2Cited by
4References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 28, 1982
Grant dateNov 15, 1983
Priority date
Expiry dateJan 28, 2002

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07C269/06
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

Production of aromatic polyisocyanates is achieved by a multireaction process comprising sequentially; the ammoxidation of a methylated aromatic, e.g. toluene; hydrolysis of the aromatic nitrile; conversion of the resultant amide to a carbamate; condensation with aldehyde; decomposition of the condensation product; and, recovery of the aromatic polyisocyanate.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.