Patent · US Expired

Process for preparing aromatic polycarbonate

US5840826A · kind A · utility

7Cited by
2References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 19, 1997
Grant dateNov 24, 1998
Priority date
Expiry dateSep 19, 2017

Classification

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

Abstract

Disclosed is a method for producing an aromatic polycarbonate which comprises subjecting to a transesterification reaction in a polymerizer at least one polymerizable material selected from a molten monomer mixture of an aromatic dihydroxy compound and a diaryl carbonate, and a molten prepolymer obtained from the monomer mixture, wherein a liquid mass of polymerizable material being transesterified in the polymerizer has an exposed surface, and wherein the transesterification reaction of the liquid mass of polymerizable material is performed under reaction conditions such that the following formula (1) is satisfied: EQU log (S/V).gtoreq.2.times.10.sup.-5 .times.Mn+0.8 (1) wherein S represents an evaporation surface area (m.sup.2) which is defined as the area (m.sup.2) of the exposed surface of the liquid mass of polymerizable material; V represents the volume (m.sup.3) of the liquid mass of polymerizable material in the polymerizer; and Mn represents the number average molecular weight of the aromatic polycarbonate to be produced.

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