US3718625A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of a polyacyloxalamidrazone
Assignee: Glanzstoff AG
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Filing: 1970-10-05
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Granted: 1973-02-27
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Expires: 1990-10-05
Abstract
Abstract Production of polyacyloxalamidrazones, especially a very high molecular weight polyterephthaloyloxalamidrazone having recurring units of the formula BY AN INTERFACIAL POLYCONDENSATION OF OXALIC ACID BISAMIDRAZONE WITH AN ACYL DIHALIDE MONOMER SUCH AS TEREPHTHALIC ACID DICHLORIDE AT TEMPERATURES OF 0*C. to 60*C. in a two-phase solvent system consisting essentially of water and a waterimmiscible, inert organic solvent, in the presence of an acid acceptor and in the presence of a substantial amount of a neutral alkali metal salt. High molecular weight polymer films or filaments can be formed from an alkaline solution of the polymer.
Inventors
- 👤 D Frank
- 👤 M Wallrabenstein
- 👤 A Schopf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:46
CPC Classifications
C; C08; C08G; C08G73/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
30 words
A process as claimed in claim 1 wherein the oxalic acid bisamidrazone is supplied to the reaction mixture at a concentration of 6.6 to 60 millimols per liter of water.
Claim 2
Dependent Claim
27 words
A process as claimed in claim 1 wherein said organic solvent is selected from the group consisting of hexane, carbon tetrachloride, benzine, petroleum ether, toluene and xylene.
Claim 3
Dependent Claim
26 words
A process as claimed in claim 1 wherein said alkali metal salt is selected from the group consisting of lithium, sodium and potassium chlorides and sulfates.
Claim 4
Dependent Claim
31 words
A process as claimed in claim 1 wherein the oxalic acid biSamidrazone is supplied to the reaction mixture at a concentration of about 6.6 to 40 millimols per liter of water.
Claim 5
Dependent Claim
26 words
A process as claimed in claim 5 wherein said alkali metal salt is selected from the group consisting of lithium, sodium and potassium chlorides and sulfates.
Claim 6
Dependent Claim
13 words
A process as claimed in claim 6 wherein said organic solvent is hexane.
Claim 7
Dependent Claim
14 words
A process as claimed in claim 6 wherein said organic solvent is carbon tetrachloride.
Claim 8
Dependent Claim
22 words
A process as claimed in claim 6 wherein said organic solvent is selected from the group consisting of benzine and petroleum ether.
Claim 9
Dependent Claim
21 words
A process as claimed in claim 6 wherein said organic solvent is selected from the group consisting of toluene and xylene.
Claim 10
Dependent Claim
31 words
A process as claimed in claim 1 wherein the oxalic acid bisamidrazone is supplied to the reaction mixture at a concentration of about 10 to 25 millimols per liter of water.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-27 | 1976-08-28 | 1977-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-27 | 1980-08-28 | 1981-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-27 | 1984-08-28 | 1985-02-27 | $7700.00 | Window Closed / Lapsed |