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US4959453A
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Process for the preparation of a poly(paraphenylene terephthalamide)fibrous gel composition and a process to produce poly(paraphenylene terephthalamide) paper from the composition
Assignee: EIDP Inc
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Filing: 1989-04-03
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Granted: 1990-09-25
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Expires: 2009-04-03
Abstract
Abstract A process for producing a fibrous gel composition of poly(paraphenylene terephthalamide) comprising the steps of placing terephthaloyl chloride in reactive contact with paraphenylene diamine in a solution of at least one amide-type polar solvent (e.g. N-methylpyrrolidone), an alkaline earth metal salt and the aliphatic tertiary amine, N-methylpyrrolidine or its hydrochloride. Poly(paraphenylene terephthalamide) papers are prepared by diluting the composition in an amide diluent, blending in a slurry of poly(paraphenylene terephthalamide) fibers in a precipitating mediu, filtering, washing, pressing and drying the mixture.
Inventors
- 👤 Wilfred Sweeny
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:40
CPC Classifications
D; D21; D21H; D21H13/00; D21H13/10; D21H13/20; D21H13/26; C; C08; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/32; D01; D01F; D01F6/00; D01F6/58; D01F6/60; D01F6/605
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
97 words
A process for preparing a poly(paraphenylene terephthalamide) fibrous gel composition consisting essentially of placing substantially stoichiometric amounts of terephthaloyl chloride in reactive contact with paraphenylene diamine in a solution, under agitation of: (a) at least one amide solvent in an amount sufficient to yield a final concentration of poly(paraphenylene terephthalamide) in the range from about 3 to about 7 percent by weight of the solvent; (b) at least 1.5 moles of an alkaline earth metal salt per mole of para-phenylenediamine; (c) and N-methylpyrrolidine present in the range of from 1.0 to 2.0 moles per mole of para-phenylenediamine.
Claim 2
Dependent Claim
97 words
A process for preparing a poly(paraphenylene terephthalamide) fibrous gel composition consisting essentially of placing substantially stoichiometric amounts of terephthaloyl chloride in reactive contact with paraphenylene diamine in a solution, under agitation of: (a) at least one amide solvent in an amount sufficient to yield a final concentration of poly(paraphenylene terephthalamide) in the range from about 3 to about 7 percent by weight of the solvent; (b) at least 1.5 moles of an alkaline earth metal salt per mole of para-phenylenediamine; (c) and N-methylpyrrolidine present in the range of from 1.0 to 2.0 moles per mole of para-phenylenediamine.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the molar ratio of N-methylpyrrolidine is 1.5 to 1.8 moles per mole of para-phenylenediamine.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein the amide solvent is N-methylpyrrolidone.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein the alkaline earth metal salt is calcium chloride.
Claim 6
Dependent Claim
98 words
A process for preparing a poly(paraphenylene terephthalamide) fibrous gel composition consisting essentially of placing substantially stoichiometric amount of terephthaloyl chloride in reactive contact with paraphenylene diamine in a solution, under agitation of: (a) at least one amide solvent in an amount sufficient to yield a final concentration of poly(paraphenylene terephthalamide) in the range from about 3 to about 7 percent by weight of the solvent; (b) at least 1.5 moles of an alkaline earth metal salt per mole of para-phenyulenediamine; (c) and N-methylpyrrolidine hydrochloride present in the range of from 1.5 to 4.0 moles per mole of para-phenylenediamine.
Claim 7
Dependent Claim
98 words
A process for preparing a poly(paraphenylene terephthalamide) fibrous gel composition consisting essentially of placing substantially stoichiometric amount of terephthaloyl chloride in reactive contact with paraphenylene diamine in a solution, under agitation of: (a) at least one amide solvent in an amount sufficient to yield a final concentration of poly(paraphenylene terephthalamide) in the range from about 3 to about 7 percent by weight of the solvent; (b) at least 1.5 moles of an alkaline earth metal salt per mole of para-phenyulenediamine; (c) and N-methylpyrrolidine hydrochloride present in the range of from 1.5 to 4.0 moles per mole of para-phenylenediamine.
Claim 8
Dependent Claim
11 words
The process of claim 5 wherein the amide solvent is N-methylpyrrolidone.
Claim 9
Dependent Claim
14 words
The process of claim 5 wherein the alkaline earth metal salt is calcium chloride.
References Cited (Backward Citations)
US3063966A
Cited
US3869429A
Cited
US4011203A
Cited
US4072664A
Cited
US4579895A
Cited
US4511623A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-24 | 1994-03-26 | 1994-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-24 | 1998-03-26 | 1998-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-24 | 2002-03-26 | 2002-09-25 | $7700.00 | Window Closed / Lapsed |