US3770390A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crystal habit modification of inorganic salts using polymeric sulfonates or sulfates
Assignee: Dow Chemical Co
•
Filing: 1971-02-26
•
Granted: 1973-11-06
•
Expires: 1991-02-26
Abstract
Abstract Disclosed herein is an improved method for crystallizing watersoluble inorganic salts. The improvement comprises adding to the crystallizing system a small amount of a monovalent salt of a polymeric sulphonate or sulfate characterized by the formula: WHEREIN R is hydrogen or methyl, m is an integer from 3 to 3,000, n is 0 or 1, and Y is a connecting group which is oxo, phenyl, phenoxy, carboxy alkyl or similar organic radical. The X portion of the sulphonate or sulfate group is a monovalent cation such as hydrogen, lithium, sodium, potassium and ammonium. The resulting crystals are larger and more regularly shaped than crystals produced by prior art methods.
Inventors
- 👤 A Teot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:34
CPC Classifications
B; B01; B01D; B01D9/00; B01D9/005; C; C01; C01C; C01C1/00; C01C1/24; C01C1/248; C01D; C01D3/00; C01D3/22; C01D3/24; C01D5/00; C01D9/00; C01D9/18; C01G; C01G3/00; C01G3/10; C01G37/00; C01G37/14
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
28 words
The process as in claim 1 wherein the water soluble inorganic salt is selected from the group consisting of potassium nitrate, potassium sulfate, potassium chloride, and ammonium sulfate.
Claim 2
Dependent Claim
35 words
A process as in claim 1 wherein from about 0.0005 to about 0.5 weight percent of polymeric sulphonate or sulfate is present in the aqueous system based on the weight of inorganic salt present therein.
Claim 3
Dependent Claim
17 words
A process as in claim 2 wherein the polymeric sulphonate is sodium polystyrene sulfonate or sodium polysulfoethylmethacrylate.
References Cited (Backward Citations)
US2226101A
Cited
US2642335A
Cited
US2720446A
Cited
US3037849A
Cited
US3248182A
Cited
US3271106A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |