US5079307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High molecular weight polyamide production from dicarboxy terminated polyamide prepolymer
Assignee: BP Chemicals Ltd
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Filing: 1990-07-23
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Granted: 1992-01-07
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Expires: 2010-07-23
Abstract
Abstract This invention relates to a process for producing polyamides of high molecular weight from dicarboxy terminated prepolymers of relatively lower molecular weight by further polymerization in an extruder in the presence of an additive comprising a diamine. The polyamides so formed are suitable for producing fabricated articles such as films, pipes, containers etc.
Inventors
- 👤 Stephen A. Taylor
- 👤 Matthew B. Studholme
- 👤 Murray R. Orpin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:08
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/28; B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/505; B29C48/67; C08G69/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
43 words
A process for producing a high molecular weight polyamide comprising prepolymerizing a nylon salt to produce a relatively low molecular weight dicarboxy terminated polyamide prepolymer and further polymerizing said prepolymer with a diamine in an extruder to produce said high molecular weight polyamide.
Claim 2
Dependent Claim
43 words
A process for producing a high molecular weight polyamide comprising prepolymerizing a nylon salt to produce a relatively low molecular weight dicarboxy terminated polyamide prepolymer and further polymerizing said prepolymer with a diamine in an extruder to produce said high molecular weight polyamide.
Claim 3
Dependent Claim
34 words
A process according to claim 1 wherein the prepolymer is produced from a nylon salt feedstock which is an adduct of an aromatic dicarboxylic acid and an aliphatic, a cycloaliphatic or an aliphatic diamine.
Claim 4
Dependent Claim
20 words
A process according to claim 1 or 2 wherein the prepolymer has a number average molecular weight of upto 5000.
Claim 5
Dependent Claim
29 words
A process according to claim 1 wherein the prepolymer is in the form of a melt, in a granulated form or in a powdered form prior to further polymerisation.
Claim 6
Dependent Claim
31 words
A process according to claim 1 wherein the prepolymer is blended with polymerisation aids selected from the group consisting of catalysts, molecular weight regulators and colour stabilisers prior to further polymerisation.
Claim 7
Dependent Claim
22 words
A process according to claim 5 wherein the polymerisation aid is a catalyst and is selected from ammonium hypophosphite or metal hypophosphites.
Claim 8
Dependent Claim
22 words
A process according to claim 5 or 6 wherein the molecular weight regulator is selected from a monofunctional carboxylic acids or amines.
Claim 9
Dependent Claim
14 words
A process according to claim 1 wherein the extruder is a twin screw extruder.
Claim 10
Dependent Claim
16 words
A process according to claim 1 wherein the diamine is introduced into the extruder by injection.
Claim 11
Dependent Claim
26 words
A process according to claim 9 wherein the additional diamine is introduced into the extruder by injection of aqueous solution of the diamine into the extruder.
Claim 12
Dependent Claim
23 words
A process according claim 1 wherein the further polymerisation is carried out under a partial vacuum adjusted by a bleed of nitrogen gas.
References Cited (Backward Citations)
US4760129A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-06 | 1995-07-08 | 1996-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-06 | 1999-07-08 | 2000-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-06 | 2003-07-08 | 2004-01-07 | $7700.00 | Window Closed / Lapsed |