Patent US2992206A successfully refreshed from Google Patents.
US2992206A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical brightening
Assignee: Imperial Chemical Industries Ltd
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Filing: 1959-02-13
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Granted: 1961-07-11
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Expires: 1979-02-13
Abstract
No abstract record available.
Inventors
- 👤 Philip V Youle
- 👤 John S M Robertson
- 👤 Joseph C Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:58
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/16; C08K5/34; C08K5/3442; C08K5/3462
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
88 words
THE IMPROVED PROCESS FOR THE PRODUCTION OF OPTICALLY BRIGHTENED FIBER- AND FILM-FORMING POLYMETHYLENE TEREPHTHALATES COMPRISING ESTERIFYING TEREPHTHALIC ACID WITH A GLYCOL OF THE SERIES HO(CH2)NOH, WHEREIN N IS AN INTEGER HAVING A VALUE FROM 2 TO 10 INCLUSIVE, POLYCONDENSING THE ESTERIFICATION PRODUCT, AND ADDING A SMALL AMOUNT OF AN OPTICAL BRIGHTENING AGENT SELECTED FROM THE GROUP CONSISTING OF 2:8 DI(2:6 DIMETHYL PHENYL)ANTHRA-1'':9''(N):5'':10''(N)- DIPYRIDAZONE AND 2:8-DI(2 METHYL 6-HYDROXY-METHYL PHENYL)-ANTHRA-1'':9''(N):5''10'' (N)-DIPYRIDAZONE, DURING THE PERIOD OF COMMENCING PRIOR TO THE ESTERIFYING AND BEFORE THE POLYESTER IS SHAPED INTO ITS FINAL FORM.
Claim 2
Dependent Claim
88 words
THE IMPROVED PROCESS FOR THE PRODUCTION OF OPTICALLY BRIGHTENED FIBER- AND FILM-FORMING POLYMETHYLENE TEREPHTHALATES COMPRISING ESTERIFYING TEREPHTHALIC ACID WITH A GLYCOL OF THE SERIES HO(CH2)NOH, WHEREIN N IS AN INTEGER HAVING A VALUE FROM 2 TO 10 INCLUSIVE, POLYCONDENSING THE ESTERIFICATION PRODUCT, AND ADDING A SMALL AMOUNT OF AN OPTICAL BRIGHTENING AGENT SELECTED FROM THE GROUP CONSISTING OF 2:8 DI(2:6 DIMETHYL PHENYL)ANTHRA-1'':9''(N):5'':10''(N)- DIPYRIDAZONE AND 2:8-DI(2 METHYL 6-HYDROXY-METHYL PHENYL)-ANTHRA-1'':9''(N):5''10'' (N)-DIPYRIDAZONE, DURING THE PERIOD OF COMMENCING PRIOR TO THE ESTERIFYING AND BEFORE THE POLYESTER IS SHAPED INTO ITS FINAL FORM.
References Cited (Backward Citations)
US2571319A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-10 | 1965-01-09 | 1965-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-10 | 1969-01-09 | 1969-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-10 | 1973-01-09 | 1973-07-11 | $7700.00 | Window Closed / Lapsed |