US3669915A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flocculants from starch graft copolymers
Assignee: United States Department of Agriculture
•
Filing: 1970-09-08
•
Granted: 1972-06-13
•
Expires: 1990-09-08
Abstract
Abstract Highly active flocculants for removing siliceous wastes and other finely divided solid suspensions from water are produced from starch by graft copolymerization with a cationic monomer having quaternary ammonium substituents.
Inventors
- 👤 Duane A Jones
- 👤 George F Fanta
- 👤 Robert C Burr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:48
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/54; B; B03; B03D; B03D1/00; B03D1/001; B03D1/004; B03D1/016; C02F1/5263; C08; C08F; C08F251/00; B03D1/01; B03D2201/00; B03D2201/002
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
31 words
A method of preparing flocculating agents from starch as described in claim 1 in which free radicals are formed by irradiating the starch with gamma rays from a cobalt 60 source.
Claim 2
Dependent Claim
30 words
A method of preparing flocculating agents from starch as described in claim 1 in which free radicals are formed by reacting the starch with ceric ammonium nitrate in nitric acid.
Claim 3
Dependent Claim
14 words
A starch graft copolymer for use as a flocculating agent having the following formula:
Claim 4
Dependent Claim
32 words
A starch graft copolymer as described in claim 4 having a grafted polymer content of about 4.5 percent, a number average molecular weight of about 80,000, and a D.S. of about 0.000095.
Claim 5
Dependent Claim
32 words
A starch graft copolymer as described in claim 4 having a grafted polymer content of about 5.2 percent, a number average molecular weight of about 400,000, and a D.S. of about 0.000022.
Claim 6
Dependent Claim
35 words
A starch graft copolymer as described in claim 4 having a grafted polymer content of about 8.5 percent, a number average molecular weight of about at least 1 million, and a D.S. of about 0.000015.
Claim 7
Dependent Claim
32 words
A starch graft copolymer as described in claim 4 having a grafted polymer content of about 12.1 percent, a number average molecular weight of about 72,000, and a D.S. of about 0.000319.
Claim 8
Dependent Claim
32 words
A starch graft copolymer as described in claim 4 having a grafted polymer content of about 15.2 percent, a number average molecular weight of about 84,000, and a D.S. of about 0.000345.
Claim 9
Dependent Claim
13 words
A flocculant prepared by dispersing the products described in claim 4 in water.
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) | 1975-06-13 | 1975-12-13 | 1976-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-13 | 1979-12-13 | 1980-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-13 | 1983-12-13 | 1984-06-13 | $7700.00 | Window Closed / Lapsed |