US4409151A
Expired / Lapsed
US
⏱️ 0.0 years remaining
N,N-Dimethylene phosphonic acids of alkylene diamines
Assignee: Baker Petrolite LLC
•
Filing: 1981-12-28
•
Granted: 1983-10-11
•
Expires: 2001-12-28
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
2026-10-31 18:40
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/173; 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: 5
Claim 1
Independent Claim
85 words
A process of preparing an N,N-dimethylene phosphonic acid 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=2-20, which comprises reacting in aqueous solution one mole of a diamine of the formula NH.sub.2 (CH.sub.2).sub.n NH.sub.2 where n has the aforesaid value, with essentially two equivalents each, based on nitrogen-bonded hydrogen, of formaldehyde and phosphorous acid, at a pH of less than 2 and a temperature from 80° to 150° C., the formaldehyde and phosphorous acid being added in either order or together to the diamine.
Claim 2
Dependent Claim
85 words
A process of preparing an N,N-dimethylene phosphonic acid 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=2-20, which comprises reacting in aqueous solution one mole of a diamine of the formula NH.sub.2 (CH.sub.2).sub.n NH.sub.2 where n has the aforesaid value, with essentially two equivalents each, based on nitrogen-bonded hydrogen, of formaldehyde and phosphorous acid, at a pH of less than 2 and a temperature from 80° to 150° C., the formaldehyde and phosphorous acid being added in either order or together to the diamine.
Claim 3
Dependent Claim
84 words
A process of preparing an N,N-dimethylene phosphonic acid 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=2-20, which comprises reacting in aqueous solution one mole of a diamine of the formula NH.sub.2 (CH.sub.2).sub.n NH.sub.2 where n has the aforesaid value, with essentially two equivalents each, based on nitrogen-bonded hydrogen, of formaldehyde and phosphorous acid, at a pH of less than 2 and a temperature from 80° C. to 150° C., the formaldehyde being added to a mixture of the diamine and phosphorous acid.
Claim 4
Dependent Claim
84 words
A process of preparing an N,N-dimethylene phosphonic acid 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=2-20, which comprises reacting in aqueous solution one mole of a diamine of the formula NH.sub.2 (CH.sub.2).sub.n NH.sub.2 where n has the aforesaid value, with essentially two equivalents each, based on nitrogen-bonded hydrogen, of formaldehyde and phosphorous acid, at a pH of less than 2 and a temperature from 80° C. to 150° C., the formaldehyde being added to a mixture of the diamine and phosphorous acid.
Claim 5
Dependent Claim
7 words
The process of claim 2 wherein n=2-6.
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) | 1986-10-10 | 1987-04-11 | 1987-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-10 | 1991-04-11 | 1991-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-10 | 1995-04-11 | 1995-10-11 | $7700.00 | Window Closed / Lapsed |