US3816356A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Melamine base polymeric sequestering agent and process
Assignee: Occidental Petroleum Corp
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Filing: 1971-10-26
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Granted: 1974-06-11
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Expires: 1991-10-26
Abstract
Abstract Water-insoluble, cross-linked sequestering resins formed by reaction with chloroacetic acid and cross-linking of melamine. The active sequestering group on the resin is -NCH2COOH or salt thereof. A process for removing polyvalent ions from water with such a resin is provided.
Inventors
- 👤 E Grannen
- 👤 L Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:57
CPC Classifications
C; C08; C08G; C08G12/00; C08G12/02; C08G12/26; C08G12/30; C08G12/32; B; B01; B01J; B01J45/00; C08F; C08F12/00; C08F12/02; C08F12/32; C08G12/40
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
28 words
A resin as defined in claim 1 comprising the reaction product when the molar ratio of chloroacetic acid to melamine is in excess of about one to one.
Claim 2
Dependent Claim
27 words
A resin as defined in claim 2 comprising the reaction product when cross-linking with formaldehyde is also conducted in the presence of phenol or a phenol-formaldehyde prepolymer.
Claim 3
Dependent Claim
90 words
A process for making a substantially water-insoluble cross-linked sequestering resin of the amino carboxylic acid type where the number of effective sequestering groups exceed one for every three amine nitrogens in the resin consisting essentially of the steps of: reacting melamine with chloracetic acid in strongly alkaline aqueous solution; and cross-linking the product of the reacting step by contact with formaldehyde, employing from about 2.5 to 3.5 moles of formaldehyde per mole of original mole of melamine, in strongly alkaline solution maintained at a pH of from 10 to 11.
Claim 4
Dependent Claim
22 words
A method as defined in claim 4 wherein tHe mole ratio of chloroacetic acid to melamine is at least one to one.
Claim 5
Dependent Claim
31 words
A method as defined in claim 6 comprising the additional step of adding an extender selected from the group consisting of phenol and a phenol-formaldehyde prepolymer prior to the cross-linking step.
Claim 6
Dependent Claim
20 words
A method as defined in claim 6 wherein the mole ratio of extender to melamine is less than about 1:1.
Claim 7
Dependent Claim
86 words
A process for removing polyvalent cations from aqueous medium comprising the step of contacting the aqueous medium with a water-insoluble, cross-linked sequestering resin consisting essentially of the reaction product of melamine and chloroacetic acid in strong alkaline solution followed by cross-linking with formaldehyde, employing from about 2.5 to 3.5 moles of formaldehyde per mole of original melamine, in strongly alkaline solution, maintained at a pH of from 10 to 11, the number of effective sequestering groups exceeding one for every three amine nitrogens in the resin.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |