Patent · US Expired

Stabilized aromatic polycarbonate

US6303734A · kind A · utility

26Cited by
0References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 19, 1999
Grant dateOct 16, 2001
Priority date
Expiry dateNov 19, 2019

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08G64/307
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

The relative intensity of fluorescent light of a melt-polycondensed aromatic polycarbonate produced by the transesterification process (melt polymerization process) of an aromatic dihydroxy compound and a carbonic acid diester in the presence of a catalyst comprising a basic nitrogen compound and/or a basic phosphorus compound in combination with an alkali metal compound is suppressed to 4.0.times.10.sup.-3 or below at a wavelength of 465 nm based on a standard substance in a fluorescent light spectrum obtained by the excitation wavelength of 320 nm. An aromatic polycarbonate having good color stability, especially good stability to the deterioration of the chip color during storage of the chip in air at room temperature can be produced by the present invention.

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