US3901854A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two stage process for preparing aromatic polyamides
Assignee: Celanese Corp
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Filing: 1973-05-14
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Granted: 1975-08-26
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Expires: 1993-05-14
Abstract
Abstract High molecular weight aromatic linear polyamides of fiberforming grade are prepared by condensation of monomeric aromatic phenyl esters of aromatic dicarboxylic acids and an aromatic diamine in about a 1 to 1 molar ratio. The condensation product is further polymerized, preferably in the solid state, to produce high viscosity linear aromatic polyamides. The described process is particularly advantageous economically because of the high yield of fiber, film and coating grade polymer coupled with the ability to recover the by-product for recycle to form the monomeric aromatic ester starting material.
Inventors
- 👤 Rufus S Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:46
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/32; C08G69/08; C08G69/12
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
43 words
A METHOD FOR PREPARING HIGH MOLECULAR WEIGHT AROMATIC POLYAMIDES COMPRISING A.HEATING AT A TEMPERATURE BETWEEN 100* AND ABOUT 345*C, IN THE PRESENCE OF AN INERT LIQUID DILUENT AND IN ABOUT A MOLE TO MOLE RATIO A MONOMERIC DIESTER COMPOUND CORRESPONDING TO THE FORMULA
Claim 2
Independent Claim
43 words
A METHOD FOR PREPARING HIGH MOLECULAR WEIGHT AROMATIC POLYAMIDES COMPRISING A.HEATING AT A TEMPERATURE BETWEEN 100* AND ABOUT 345*C, IN THE PRESENCE OF AN INERT LIQUID DILUENT AND IN ABOUT A MOLE TO MOLE RATIO A MONOMERIC DIESTER COMPOUND CORRESPONDING TO THE FORMULA
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein R is hydrogen, phenyl, halogen, aliphatic or alkoxy of 1 to 6 carbon atoms.
Claim 4
Dependent Claim
33 words
The method of claim 2 wherein the inert liquid diluent of claim 1 step (a) is a solvent for the monomeric diester and the diamine, and is removed after formation of the oligomer.
Claim 5
Dependent Claim
35 words
The method of claim 2 wherein the inert liquid diluent of claim 1 step (a) is a solvent for the aromatic polyamide product and is present during the heat treatments of steps (a) and (b).
Claim 6
Dependent Claim
41 words
The method of claim 2 wherein the inert liquid diluent of claim 1 step (a) is a solvent for the monomeric diester, the diamine and the aromatic polyamide product, and is present during the heat treatments of steps (a) and (b).
Claim 7
Dependent Claim
30 words
The method of claim 5 wherein sufficient inert liquid diluent is present so as to serve as a heat transfer agent during the heat treatments of steps (a) and (b).
Claim 8
Dependent Claim
31 words
The method of claim 2 wherein the monomeric diester compound and diamine are reacted under superatmospheric pressure and said pressure is reduced to atmospheric or subatmospheric aftEr formation of said oligomer.
Claim 9
Dependent Claim
10 words
The method of claim 7 wherein the diamine is paraphenylenediamine.
Claim 10
Dependent Claim
12 words
The method of claim 8 wherein the monomeric diester compound is diphenylterephthalate.
Claim 11
Dependent Claim
12 words
The method of claim 9 wherein the volatilized monomeric by-products are recovered.
Claim 12
Dependent Claim
19 words
The method of claim 10 wherein the volatilized monomeric by-products are recycled to form the monomeric diester starting material.
Claim 13
Dependent Claim
20 words
The method of claim 11 wherein an excess of up to about 2 mole percent of one reactant is used.
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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |