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US4460762A
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Preparation of high molecular polytetramethylene adipamide
Assignee: Stamicarbon BV
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Filing: 1981-03-25
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Granted: 1984-07-17
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Expires: 2001-03-25
Abstract
Abstract A process is described for the preparation of high-molecular weight white polyamides, substantially consisting of units of --NH--(CH 2 ) 4 --NH--CO(CH 2 ) 4 --CO--, by the after-condensation of a corresponding low-molecular prepolymer, consisting substantially of a molecular chain of units of --NH--(CH 2 ) 4 --NH--CO(CH 2 ) 4 --CO--, in which process the prepolymer which is employed has been prepared in the presence of an excess of 0.5 to 15 moles-% of 1,4-diaminobutane with respect to the quantity stoichiometrically equivalent to the adipic acid applied. This prepolymer is thereafter subjected to the after-condensation reaction in the solid phase in an atmosphere containing water vapor.
Inventors
- 👤 Reinoud J. Gaymans
- 👤 Edmond H. J. P. Bour
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:29
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/28
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
170 words
A process for the preparation of a white, high-molecular-weight nylon 4,6 polyamide, substantially consisting of units of --NH--(CH.sub.2).sub.4 --NH--CO--(CH.sub.2) .sub.4 --CO--, which process consists essentially in first forming a polyamide prepolymer having a number-average molecular weight M n less than about 10,000 by condensation reaction between 1,4-diaminobutane and adipic acid wherein said 1,4-diaminobutane is present in an amount of from 0.5 to 15 mole % in excess of the molar amount of said adipic acid, said polyamide prepolymer having (1) a content of cyclic end groups not exceeding 0.20 mg equivalent per g of prepolymer, and (2) wherein the number of amino end-groups at least equals the sum of both (i) the number of carboxyl end groups, and (ii) the number of any other end-groups; and thereafter after-condensing said prepolymer, (a) in the solid phase and (b) under a water-vapor-containing atmosphere and (c) at a temperature of at least 200° C. to obtain a white, high-molecular-weight nylon 4,6 polymer of a number-average molecular weight M n greater than about 15,000.
Claim 2
Dependent Claim
170 words
A process for the preparation of a white, high-molecular-weight nylon 4,6 polyamide, substantially consisting of units of --NH--(CH.sub.2).sub.4 --NH--CO--(CH.sub.2) .sub.4 --CO--, which process consists essentially in first forming a polyamide prepolymer having a number-average molecular weight M n less than about 10,000 by condensation reaction between 1,4-diaminobutane and adipic acid wherein said 1,4-diaminobutane is present in an amount of from 0.5 to 15 mole % in excess of the molar amount of said adipic acid, said polyamide prepolymer having (1) a content of cyclic end groups not exceeding 0.20 mg equivalent per g of prepolymer, and (2) wherein the number of amino end-groups at least equals the sum of both (i) the number of carboxyl end groups, and (ii) the number of any other end-groups; and thereafter after-condensing said prepolymer, (a) in the solid phase and (b) under a water-vapor-containing atmosphere and (c) at a temperature of at least 200° C. to obtain a white, high-molecular-weight nylon 4,6 polymer of a number-average molecular weight M n greater than about 15,000.
Claim 3
Dependent Claim
17 words
Method according to claim 1, wherein said excess is between 1 and 5 moles-% of 1,4 diaminobutane.
Claim 4
Dependent Claim
18 words
Method according to claim 2, wherein the said atmosphere contains at least 5% by volume of water vapor.
Claim 5
Dependent Claim
16 words
Method according to claim 1, wherein an acid polycondensation catalyst is also present in said prepolymer.
Claim 6
Dependent Claim
36 words
Method according to any one of claims 1, 2, 3, or 4, wherein said after-condensation is conducted at a pressure of between 0.001 and 10 bar and a temperature of between 225° C. and 275° C.
Claim 7
Dependent Claim
19 words
Method according to any one of claims 1, 2, 3, or 4, wherein the homopolymer polytetramethylene adipamide is obtained.
Claim 8
Dependent Claim
29 words
Method according to any of claims 1, 2 3 or 4 wherein the prepolymer which is subjected to after-condensation contains an amount of cyclic endgroups not exceeding 0.15 mgeq/g.
Claim 9
Dependent Claim
29 words
Method according to any of claims 1, 2, 3 or 4 wherein the prepolymer which is subjected to after-condensation contains an amount of cyclic endgroups not exceeding 0.10 mgeq/g.
References Cited (Backward Citations)
US2130948A
Cited
GB614625A
Cited
US3840500A
Cited
US3676400A
Cited
JPS4917036A
Cited
GB1493497A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-17 | 1988-01-16 | 1988-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-17 | 1992-01-16 | 1992-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-17 | 1996-01-16 | 1996-07-17 | $7700.00 | Window Closed / Lapsed |