US3697497A
Expired / Lapsed
US
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Hexamethylene tetramine derivatives of alkali lignins
Assignee: Bayer AG
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Filing: 1970-09-17
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Granted: 1972-10-10
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Expires: 1990-09-17
Abstract
Abstract Hexamethylene tetramine derivatives of alkali lignins are formed by reacting, at a temperature between 70* C. and 180* C., 0.17 to 2.0 moles of a hexamethylene tetramine forming solution with 1 mole of an alkali lignin solubilized in an alkaline solution. These derivatives, characterized by having a high molecular weight and a high melting point, are useful as stabilizers in rubber emulsion, high molecular weight resin-like fillers and may be converted into products having large surface areas.
Inventors
- 👤 Alfons Dorlars
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:59
CPC Classifications
C; C08; C08H; C08H6/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
14 words
The derivatives of claim 1 wherein said alkaline solution is an aqueous ammonical solution.
Claim 2
Dependent Claim
13 words
The derivatives of claim 1 wherein said alkali lignin is a demethylated lignin.
Claim 3
Dependent Claim
19 words
The derivatives of claim 1 wherein said derivatives have a wet melting point of from 150* to 220* C.
Claim 4
Dependent Claim
52 words
The process of producing large surface area lignin derivatives which comprises, reacting in an aqueous medium an alkali lignin with from 0.17 to 2.0 moles of hexamethylene tetramine per mole of lignin at a temperature between 70* and 180* C., mixing said product with varsol and acetic acid, and drying said mixture.
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) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |