Patent US4719284A successfully refreshed from Google Patents.
US4719284A
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US
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Multistage process for the preparation of poly(tetramethylene-adipamide)
Assignee: Bayer AG
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Filing: 1986-07-16
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Granted: 1988-01-12
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Expires: 2006-07-16
Abstract
Abstract Process for the preparation of polyamides from 1,4-diaminobutane and adipic acid, wherein a 40 to 70% strength aqueous solution of the monomers is heated at 280°-320° C., preferably 290°-310° C., for a period of 5 to 30 minutes under a pressure of less than 8 bar, to give a precondensate having a relative viscosity of 1.05 to 2.0, and solid phase after-condensation at 180°-260° C.
Inventors
- 👤 Werner Nielinger
- 👤 Hermann Brinkmeyer
- 👤 Rudolf Binsack
- 👤 Ludwig Bottenbruch
- 👤 Heinz-Josef Fullmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:44
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/28
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
82 words
A process for the production of polyamide from 1,4-diaminobutane monomer and adipic acid monomer, wherein a 40 to 70% strength aqueous solution of the monomers is heated at 280° to 320° C. for a period of 5 to 30 minutes under a pressure of less than 8 bar to give a precondensate having a relative viscosity of 1.05 to 2.0 as measured on a 1% strength solution in m-cresol at 25° C. and thereafter condensing the precondensate at 180° to 260° C.
Claim 2
Dependent Claim
82 words
A process for the production of polyamide from 1,4-diaminobutane monomer and adipic acid monomer, wherein a 40 to 70% strength aqueous solution of the monomers is heated at 280° to 320° C. for a period of 5 to 30 minutes under a pressure of less than 8 bar to give a precondensate having a relative viscosity of 1.05 to 2.0 as measured on a 1% strength solution in m-cresol at 25° C. and thereafter condensing the precondensate at 180° to 260° C.
Claim 3
Dependent Claim
19 words
A process according to claim 1, wherein the solution of the monomers is heated at 290° to 310° C.
Claim 4
Dependent Claim
22 words
A process according to claim 1, wherein the solution of the monomers is heated under a pressure of 1 to 5 bar.
Claim 5
Dependent Claim
24 words
A process according to claim 1, wherein the reaction is carried out to give a precondensate having a relative viscosity of 1.1 to 1.5.
Claim 6
Dependent Claim
17 words
A process according to claim 1, wherein the after-condensation is carried out at 200° to 250° C.
Claim 7
Dependent Claim
13 words
A process according to claim 1, wherein the process is carried our continuously.
Claim 8
Dependent Claim
25 words
A process according to claim 1, wherein the precondensation is carried out under steam and the after-condensation is carried out without the addtion of steam.
Claim 9
Dependent Claim
31 words
A process as claimed in claim 1, wherein the process is carried out discontinuously and the aqueous solution is first heated to at most 220° C. and then to 280° C.
Claim 10
Dependent Claim
17 words
A process according to claim 1, wherein up to 20 mol % of a comonomer are cocondensed.
Claim 11
Dependent Claim
26 words
A process according to claim 9, wherein the comonomer is at least one ω-aminocarboxylic acid, dicarboxylic acid other than adipic acid, or diamine other than 1,4-diaminobutane.
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) | 1991-01-11 | 1991-07-13 | 1992-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-11 | 1995-07-13 | 1996-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-11 | 1999-07-13 | 2000-01-12 | $7700.00 | Window Closed / Lapsed |