US3907927A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water-soluble, vinyl-pyrrolidone-acrylamide block copolymers
Assignee: Calgon Corp
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Filing: 1974-04-30
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Granted: 1975-09-23
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Expires: 1994-04-30
Abstract
Abstract Block polymers of the A-B-A type wherein the A block is derived from a water-soluble monomer and the B block is derived from Nvinyl pyrrolidone. The polymers are water soluble and are useful as flocculants.
Inventors
- 👤 Lawrence James Guilbault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:12
CPC Classifications
C; C08; C08F; C08F293/00; C02; C02F; C02F1/00; C02F1/52; C02F1/54
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
34 words
A BLOCK POLYMER OF THE FORMULA A-B-A WHEREIN THE A BLOCK REPRESENTS FROM 10 TO 100,000 MER UNITS OF ACRYLAMIDE MONOMER AND THE B BLOCK REPRESENTS FROM 10 TO 5,000 NER UNITS OF N-VINYLPYRROLIDONE.
Claim 2
Dependent Claim
34 words
A BLOCK POLYMER OF THE FORMULA A-B-A WHEREIN THE A BLOCK REPRESENTS FROM 10 TO 100,000 MER UNITS OF ACRYLAMIDE MONOMER AND THE B BLOCK REPRESENTS FROM 10 TO 5,000 NER UNITS OF N-VINYLPYRROLIDONE.
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) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |