Patent · US Expired

Process for the synthesis of polyamides

US5416189A · kind A · utility

12Cited by
3References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 3, 1993
Grant dateMay 16, 1995
Priority date
Expiry dateNov 3, 2013

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08G69/28
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

Process for the synthesis of polyamides by polycondensation in a closed reactor of one or a number of dicarboxylic acids with a diamine compound containing not less than 60 mol % of-m-xylyenediamine, in which all the amount of diamine compound stoichiometrically necessary for the polycondensation reaction is quickly brought into contact with the molten acid, the temperature of the reaction mixture is raised to a value greater than the melting point of the polyamide produced, the pressure is only allowed to rise to a value sufficient to prevent solidification of the reaction mixture and a substantial loss of diamine compound and, at the end of the reaction, the pressure of the reaction mixture is reduced and the polyamide formed is recovered.

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