US4330487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
N,N-Dimethylene phosponic acids of alkylene diamines
Assignee: Baker Hughes Holdings LLC
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Filing: 1980-10-29
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Granted: 1982-05-18
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Expires: 2000-10-29
Abstract
Abstract This invention relates to a process of preparing N,N'-disubstituted methylene phosphonic acids by reacting α, ω-alkylene diamines with essentially 2 equivalents of formaldehyde and phosphorus acid based on replaced nitrogen-bonded hydrogens. This invention also relates to compositions formed by the process and to the uses for these compositions such as for inhibiting scale, etc.
Inventors
- 👤 Derek Redmore
- 👤 William S. Paley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:14
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/167; C23F11/1676; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/14; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/38; C07F9/3804; C07F9/3808; C07F9/3817
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
12 words
The composition of the formula NH.sub.2 (CH.sub.2).sub.n N(CH.sub.2 PO.sub.3 H.sub.2).sub.2 where n=6.
Claim 2
Dependent Claim
12 words
The composition of the formula NH.sub.2 (CH.sub.2).sub.n N(CH.sub.2 PO.sub.3 H.sub.2).sub.2 where n=6.
References Cited (Backward Citations)
US2599807A
Cited
US3288846A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-17 | 1985-11-16 | 1986-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-17 | 1989-11-16 | 1990-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-17 | 1993-11-16 | 1994-05-18 | $7700.00 | Window Closed / Lapsed |