US3876573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyacrylamide particles coated with a powder
Assignee: Cassella Farbwerke Mainkur AG
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Filing: 1973-09-13
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Granted: 1975-04-08
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Expires: 1993-09-13
Abstract
Abstract Particulated, non-flowable, water-soluble, water-containing polyacrylamide polymers having a molecular weight of from 2 to 12 million coated with a powder which is insoluble or hardly soluble in water and capable of binding water and thus prevents agglomeration or melting together of the particles and the utility thereof in the flocculation and/or sedimentation of solids from water.
Inventors
- 👤 Friedrich Engelhardt
- 👤 Gunter Gruber
- 👤 Joachim Ribka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:05
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/124; C02; C02F; C02F1/00; C02F1/52; C02F1/5227; C02F1/5263; C08J2333/00; C08J2333/24; C08J2333/26
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
86 words
A STORAGE STABLE COMPOSITION COMPRISING PARTICULATED NON-FLOWABLE, WATER-SOLUBLE, WATER-CONTAINING POLYACRYLAMIDE POLYMER GEL HAVNG A MOLECULAR WEIGHT OF FROM 2 TO 12 MILLION AND A PARTICLE SIZE OF FROM ABOUT 0.2 TO 5 MM AND A COATING FOR SAID PARTICLES COMPRISING A POWDER WHICH IS SELECTED FROM THE GROUP CONSISTING OF CORN, POTATO, RICE AND WHEAT STARCH AND WHEAT, CORN AND RYE FLUOR, SAID POWDER BEING PRESENT IN AN AMOUNT OF FROM ABOUT 0.5 TO 35% BY WEIGHT BASED ON THE WEIGHT OF SAID POLYMER GEL PARTICLES.
Claim 2
Dependent Claim
86 words
A STORAGE STABLE COMPOSITION COMPRISING PARTICULATED NON-FLOWABLE, WATER-SOLUBLE, WATER-CONTAINING POLYACRYLAMIDE POLYMER GEL HAVNG A MOLECULAR WEIGHT OF FROM 2 TO 12 MILLION AND A PARTICLE SIZE OF FROM ABOUT 0.2 TO 5 MM AND A COATING FOR SAID PARTICLES COMPRISING A POWDER WHICH IS SELECTED FROM THE GROUP CONSISTING OF CORN, POTATO, RICE AND WHEAT STARCH AND WHEAT, CORN AND RYE FLUOR, SAID POWDER BEING PRESENT IN AN AMOUNT OF FROM ABOUT 0.5 TO 35% BY WEIGHT BASED ON THE WEIGHT OF SAID POLYMER GEL PARTICLES.
Claim 3
Dependent Claim
16 words
The storage-stable composition of claim 1 wherein said molecular weight is from 3 to 9 million.
Claim 4
Dependent Claim
17 words
The storage-stable composition of claim 1 wherein said particle size is from about 0.5 to 2 mm.
Claim 5
Dependent Claim
19 words
The storage-stable composition of claim 1 wherein said percentage by weight is from about 2 to 10% by weight.
Claim 6
Dependent Claim
25 words
The storage-stable composition of claim 1 wherein there is a lower water content at the surfaces of said gel particles than toward the centers thereof.
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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |