Patent US6264630B1 successfully refreshed from Google Patents.
US4016142A
Expired / Lapsed
US
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Process for the control of carboxyl end groups in fiber-forming polyesters
Assignee: Millhaven Fibers Ltd
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Filing: 1966-11-09
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Granted: 1977-04-05
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Expires: 1986-11-09
Abstract
Abstract In the preparation of a fiber-forming polyester, the number of free carboxyl end groups present in the polymer may be reduced by adding to the polymerized polyester a glycidyl ether which reacts with the carboxyl end groups present to form free hydroxyl end groups.
Inventors
- 👤 William Alexander
- 👤 Alfredo Guillermo Causa
- 👤 James Girvan Fraser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:46
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/40; C08G63/42
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
54 words
A process for reducing the concentration of free carboxyl groups in a synthetic linear fibre-forming polyethylene terephthalate comprising reacting said polyethylene terephthalate in molten form with 1-butoxy glycidyl ether, whereby polyethylene terephthalate having a concentration of free carboxyl end groups of less than 30 equivalents per million grams of said polyethylene terephthalate is produced.
Claim 2
Dependent Claim
54 words
A process for reducing the concentration of free carboxyl groups in a synthetic linear fibre-forming polyethylene terephthalate comprising reacting said polyethylene terephthalate in molten form with 1-butoxy glycidyl ether, whereby polyethylene terephthalate having a concentration of free carboxyl end groups of less than 30 equivalents per million grams of said polyethylene terephthalate is produced.
Claim 3
Dependent Claim
54 words
A process for reducing the concentration of free carboxyl groups in a synthetic linear fibre-forming polyethylene terephthalate comprising reacting said polyethylene terephthalate in molten form with 3-chloroethyl glycidyl ether, whereby polyethylene terephthalate having a concentration of free carboxyl end groups of less than 30 equivalents per million grams of said polyethylene terephthalate is produced.
Claim 4
Dependent Claim
54 words
A process for reducing the concentration of free carboxyl groups in a synthetic linear fibre-forming polyethylene terephthalate comprising reacting said polyethylene terephthalate in molten form with 3-chloroethyl glycidyl ether, whereby polyethylene terephthalate having a concentration of free carboxyl end groups of less than 30 equivalents per million grams of said polyethylene terephthalate is produced.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |