Patent US5049647A successfully refreshed from Google Patents.
US5049647A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the reduction of impurities in polyester resins
Assignee: Cobarr SpA
•
Filing: 1988-12-27
•
Granted: 1991-09-17
•
Expires: 2008-12-27
Abstract
Abstract A method for purifying polyethyleneterephthalate reins by contacting the resins with an atmosphere containing carbon dioxide under supercritical conditions.
Inventors
- 👤 Hussain A. Al-Ghatta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:57
CPC Classifications
C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; B; B29; B29K; B29K2105/00; B29K2105/0002; C08J2367/00; C08J2367/02; G; G01; G01N; G01N1/00; G01N1/02; G01N1/22; G01N1/2226; G01N2001/2229; G01N33/00; G01N33/44; G01N33/442; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/54; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
25 words
A method for purifying polyethyleneterephthalate based materials comprising: contacting the polyethyleneterephthalate materials with an atmosphere comprising carbon dioxide under supercritical conditions of temperature and pressure.
Claim 2
Independent Claim
25 words
A method for purifying polyethyleneterephthalate based materials comprising: contacting the polyethyleneterephthalate materials with an atmosphere comprising carbon dioxide under supercritical conditions of temperature and pressure.
Claim 3
Dependent Claim
12 words
The method according to claim 1, wherein the materials are polyethyleneterephthalate resins.
Claim 4
Dependent Claim
20 words
The method according to claim 1, wherein the contacting step is carried out at a pressure greater than 50 bars.
Claim 5
Dependent Claim
22 words
The method according to claim 1, wherein the contacting step is carried out at a temperature between 31° C. and 245° C.
Claim 6
Dependent Claim
13 words
The method according to claim 1, wherein the atmosphere further comprises water vapour.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-09-16 | 1995-03-18 | 1995-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-16 | 1999-03-18 | 1999-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-16 | 2003-03-18 | 2003-09-17 | $7700.00 | Window Closed / Lapsed |