Patent · US Expired

Process for producing polycarbonate resin molding material having low particle content with vented extruder

US4845193A · kind A · utility

14Cited by
3References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 21, 1988
Grant dateJul 4, 1989
Priority date
Expiry dateJul 21, 2008

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08G64/40
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

A process for producing a low-particle polycarbonate resin molding material suitable for use as molding material for optical materials is disclosed, which comprises directly supplying a polycarbonate resin wet powder having a water content of from 0.5 to 10.0% by weight and an organic solvent content of from 0.01 to 5.0% by weight, said wet powder, when dried, having a weight average particle diameter of from 5 to 60 mesh, to a vented extruder and extruding the wet powder while venting to obtain pellets containing not more than 20 ppm of a residual halogenated hydrocarbon. The molding material has a greatly decreased solvent content while being freed from a particle content increase.

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