Patent US4042324A successfully refreshed from Google Patents.
US4042324A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for inhibiting the corrosions and deposition of boiler scale in water-conveying systems
Assignee: Hoechst AG
•
Filing: 1976-02-03
•
Granted: 1977-08-16
•
Expires: 1996-02-03
Abstract
Abstract Corrosion and deposition of boiler scale in water-conveying systems are inhibited. To this end the water is admixed with at least one carboxy-alkane compound of phosphorus of the general formula: ##STR1## in which each of the substituents R 1 , R 2 , R 3 , and R 4 stands for hydrogen or an alkyl group having from 1 to 4 carbon atoms, R 5 stands for hydrogen, an OH-group or an alkyl group having from 1 to 3 carbon atoms, and n stands for 0 or 1, or with at least one water-soluble salt thereof.
Inventors
- 👤 Theodor Auel
- 👤 Hannsjorg Ulrich
- 👤 Horst-Dieter Wasel-Nielen
- 👤 Gero Heymer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:50
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
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
98 words
A process for inhibiting the phenomena of corrosion and deposition of boiler scale in water-conveying systems, which comprises admixing the water with at least one carboxy-alkane compound of phosphorus of the general formula: ##STR9## in which each of the substituents R 1 , R 2 , R 3 and R 4 stands for hydrogen or an alkyl group having from 1 to 4 carbon atoms, R 5 stands for hydrogen, an OH--group or an alkyl group having from 1 to 3 carbon atoms, and n stands for 0 or 1, or with at least one water-soluble salt thereof.
Claim 2
Dependent Claim
98 words
A process for inhibiting the phenomena of corrosion and deposition of boiler scale in water-conveying systems, which comprises admixing the water with at least one carboxy-alkane compound of phosphorus of the general formula: ##STR9## in which each of the substituents R 1 , R 2 , R 3 and R 4 stands for hydrogen or an alkyl group having from 1 to 4 carbon atoms, R 5 stands for hydrogen, an OH--group or an alkyl group having from 1 to 3 carbon atoms, and n stands for 0 or 1, or with at least one water-soluble salt thereof.
Claim 3
Dependent Claim
36 words
The process as claimed in claim 1, wherein the water is admixed with at least one member selected from the group consisting of carboxy-methane-phosphonic acid; 1-carboxy-ethane-1-phosphonic acid; 1-carboxy-ethane-2-phosphonic acid; 2-carboxy-propane-3-phosphonic acid; 1-carboxy-propane-2-phosphonic acid; and methyl-(carboxyethyl)-phosphinic acid.
References Cited (Backward Citations)
US3630790A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |