Patent · US Expired

Diphenyl oxide bromination process

US5210321A · kind A · utility

4Cited by
3References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 25, 1991
Grant dateMay 11, 1993
Priority date
Expiry dateSep 25, 2011

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07C43/29
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

A process for producing a mixture of brominated diphenyl oxides with an average bromine number of 7.0 to 7.8 is improved by the utilization of a multi-step, multi-catalyst procedure. The process uses a zirconium catalyst in the first reaction and an iron catalyst in the second reaction to yield a whiter flame retardant product having less tendency to discolor plastic resins.

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