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Patent US3876586A successfully refreshed from Google Patents.
US3876586A
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Production of a polyacyloxalamidrazone
Assignee: Akzona Inc
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Filing: 1973-08-30
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Granted: 1975-04-08
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Expires: 1993-08-30
Abstract
Abstract Production of polyacyloxalamidrazones, especially a very high molecular weight polyterephthaloyloxalamidrazone having recurring units of the formula By a polycondensation of oxalic acid bisamidrazone with an acyl dihalide monomer such as terephthalic acid dichloride at temperatures of 0.degree.C. to 60.degree.C. in a two phase solvent system consisting essentially of water and a very pure tetrahydrofuran, with the addition of a substantial amount of lithium chloride or lithium sulfate as a salting-out agent and in the presence of an alkali metal carbonate or bicarbonate as an acid acceptor. High molecular weight polymer films or filaments can be formed from an alkaline solution of the polymer. D R A W I N G
Inventors
- 👤 Michael Wallrabenstein
- 👤 Albert Schopf
- 👤 Dieter Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:46
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
176 words
IN A PROCESS FOR THE PRODUCTION OF POLYTEREPHTHALOYLOXALAMIDRAZONE BY THE POLYCONDENSATION REACTION OF OXALIC ACID BISAMIDRAZONE WITH TEREPHTHALIC ACID DICHLORIDE IN A TWO PHASE SOLVENT SYSTEM AND IN THE PRESENCE OF AN ACID ACCEPTOR WHILE MIXING AND WITHDRAWING THE HEAT OF REACTION, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT THE POLYCONDENSATION REACTION AT A TEMPERATURE OF ABOUT 0*C. TO 60*C. IN A SOLVENT MIXTURE OF WATER AND A SUBSTATIALLY PURE TETRAHYDROFURAN WITH A VOLUME RATIO OF WATER:TETRAHYDROFURAN OF ABOUT 2:1 TO 1:2, IN THE PRESENCE OF A SALTING-OUT AGENT SELECTED FROM THE GROUP CONSISTING OF LITHIUM CHLORIDE AND LITHIUM SULFATE IN AN AMOUNT OF 7.5 TO 30 PERCENT BY WEIGHT WITH REFERENCE TO THE AMOUNT OF WATER AND IN THE PRESENCE OF AN ACID ACCEPTOR SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL CARBONATES AND BICARBONATES, THE REACTION PERIOD BEING SUFFICIENT TO YIELD A POLYTEREPHTHALOYLOXALAMIDRAZONE HAVING A REDUCED VISCOSITY OF ABOUT 7 TO 12, MEASURED AS A SOLUTION OF 1 GRAM OF THE POLYCONDENSATE IN 100 ML. OF A 10 PERCENT POTASSIUM HYDROXIDE AQUEOUS SOLUTION AT 20*C.
Claim 2
Dependent Claim
176 words
IN A PROCESS FOR THE PRODUCTION OF POLYTEREPHTHALOYLOXALAMIDRAZONE BY THE POLYCONDENSATION REACTION OF OXALIC ACID BISAMIDRAZONE WITH TEREPHTHALIC ACID DICHLORIDE IN A TWO PHASE SOLVENT SYSTEM AND IN THE PRESENCE OF AN ACID ACCEPTOR WHILE MIXING AND WITHDRAWING THE HEAT OF REACTION, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT THE POLYCONDENSATION REACTION AT A TEMPERATURE OF ABOUT 0*C. TO 60*C. IN A SOLVENT MIXTURE OF WATER AND A SUBSTATIALLY PURE TETRAHYDROFURAN WITH A VOLUME RATIO OF WATER:TETRAHYDROFURAN OF ABOUT 2:1 TO 1:2, IN THE PRESENCE OF A SALTING-OUT AGENT SELECTED FROM THE GROUP CONSISTING OF LITHIUM CHLORIDE AND LITHIUM SULFATE IN AN AMOUNT OF 7.5 TO 30 PERCENT BY WEIGHT WITH REFERENCE TO THE AMOUNT OF WATER AND IN THE PRESENCE OF AN ACID ACCEPTOR SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL CARBONATES AND BICARBONATES, THE REACTION PERIOD BEING SUFFICIENT TO YIELD A POLYTEREPHTHALOYLOXALAMIDRAZONE HAVING A REDUCED VISCOSITY OF ABOUT 7 TO 12, MEASURED AS A SOLUTION OF 1 GRAM OF THE POLYCONDENSATE IN 100 ML. OF A 10 PERCENT POTASSIUM HYDROXIDE AQUEOUS SOLUTION AT 20*C.
Claim 3
Dependent Claim
16 words
A process as claimed in claim 1 wherein the reaction temperature is about 10.degree.C. to 40.degree.C.
Claim 4
Dependent Claim
59 words
A process as claimed in claim 1 wherein the volume ratio of water:tetrahydrofuran is about 3:2 to 1:1, the salting-out agent is present in an amount of about 10 to 25 percent by weight with reference to the amount of water and the acid acceptor is a compound selected from the group consisting of sodium carbonate and potassium carbonate.
Claim 5
Dependent Claim
14 words
A process as claimed in claim 3 wherein the salting-out agent is lithium chloride.
Claim 6
Dependent Claim
14 words
A process as claimed in claim 3 wherein the salting-out agent is lithium sulfate.
Claim 7
Dependent Claim
16 words
A process as claimed in claim 3 wherein the reaction temperature is about 10.degree.C. to 40.degree.C.
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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |