IP Library › Granted Patent US 10,435,507
Granted Patent B2
US 10,435,507 · App. 15/789,704 · Granted Oct 8, 2019

Ultra-high purity polycarbonates having good inherent color and thermal resistance and a device and a method for producing the same

Inventors: Thomas Koenig (Leverkusen, DE); Joerg Kirchhoff (Cologne, DE); Michael Bierdel (Leverkusen, DE); Klemens Kohlgrueber (Kurten, DE); Johann Rechner (Kempen, DE); Ing. Johan Vaes (Kalmthout, BE); Johan Vanden Eynde (Zwijnaarde, BE); Frank Bruynseels (Sint Gillis, BE); Bert Ruytinx (Halen, BE)
Assignee: COVESTRO DEUTSCHLAND AG
C08G64/406B29C48/07B29C48/13B29C48/38B29C48/385B29C48/39B29C48/40B29C48/767C08G64/205B29K2069/00
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Quick Facts
Patent No.
US 10,435,507
App. No.
15/789,704
Granted
Oct 8, 2019
Kind
B2
Abstract

The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Claims (8)

1. An aromatic polycarbonate comprising less than 10 ppm of aromatic chlorine compounds, less than 1 ppm of dichloromethane, less than 15 ppm of monohydric phenols, and less than 10 ppm of aromatic compounds containing no chlorine.

2. The aromatic polycarbonate as claimed in claim 1 , comprising less than 5 ppm of aromatic compounds containing no chlorine.

3. The aromatic polycarbonate as claimed in claim 1 , comprising less than 0.01 ppm of carbon tetrachloride, less than or equal to 2 ppm of diaryl carbonates, less than or equal to 2 ppm of bisphenols, less than 0.05 ppm of alkali metals, less than 1 ppm of cresols, and less than 300 ppm of phenolic OH groups.

4. The aromatic polycarbonate as claimed in claim 2 , comprising less than 0.01 ppm of carbon tetrachloride, less than or equal to 2 ppm of diaryl carbonates, less than or equal to 2 ppm of bisphenols, less than 0.05 ppm of alkali metals, less than 1 ppm of cresols, and less than 300 ppm of phenolic OH groups.

5. The aromatic polycarbonate as claimed in claim 1 , comprising less than 1 ppm of pyridine.

6. The aromatic polycarbonate as claimed in claim 1 , comprising less than 0.1 ppm of pyridine.

7. The aromatic polycarbonate as claimed in claim 2 , comprising less than 1 ppm of pyridine.

8. The aromatic polycarbonate as claimed in claim 2 , comprising less than 0.1 ppm of pyridine.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 27, 2018
From: KONIG, THOMAS; KIRCHHOFF, JORG; BIERDEL, MICHAEL; KOHLGRUBER, KLEMENS; RECHNER, JOHANN; VAES, JOHAN; VANDEN EYNDE, JOHAN; BRUYNSEELS, FRANK; RUYTINX, BERT
To: BAYER MATERIALSCIENCE AG
Reel/Frame 045049/0746 →
CHANGE OF NAME Recorded Feb 27, 2018
From: BAYER MATERIALSCIENCE AG
To: COVESTRO DEUTSCHLAND AG
Reel/Frame 045453/0605 →
Priority Claims (1)
EP 09007270 · May 30, 2009 · regional
Continuity (2)
Continuation 13375052
Related Publication 20180105644A1 · Apr 19, 2018