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Patent US4814356A successfully refreshed from Google Patents.
US4814356A
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High molecular weight polytetramethyleneadipamide pellets
Assignee: DSM IP Assets BV
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Filing: 1988-04-05
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Granted: 1989-03-21
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Expires: 2008-04-05
Abstract
Abstract The invention relates to a method for the production of high-molecular polytetramethylene adipamide in a two-step process in which the prepolymer particles obtained in the first process step are compressed into pellets which are subjected to the after-condensation reaction. The obtained high-molecular polytetramethylene adipamide pellets can be used without further shaping through e.g. melt extrusion.
Inventors
- 👤 Antonius J. P. Bongers
- 👤 Eize Roerdink
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:24
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/28; Y; Y10; Y10S; Y10S521/00; Y10S521/918
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
62 words
Compressed porous prepolymer polyamide pellets for use in the production of high molecular weight polyamide articles, said polyamide pellets consisting essentially of units having the formula, --NH--(CH.sub.2).sub.4 --NH--CO--(CH.sub.2).sub.4 --CO--, said polyamide pellets having a size of between about 1 mm and about 20 mm, a porosity of between 0.1 and 20 vol. % and crushing strength of at least about 0.5 kg.
Claim 2
Dependent Claim
62 words
Compressed porous prepolymer polyamide pellets for use in the production of high molecular weight polyamide articles, said polyamide pellets consisting essentially of units having the formula, --NH--(CH.sub.2).sub.4 --NH--CO--(CH.sub.2).sub.4 --CO--, said polyamide pellets having a size of between about 1 mm and about 20 mm, a porosity of between 0.1 and 20 vol. % and crushing strength of at least about 0.5 kg.
Claim 3
Dependent Claim
31 words
Compressed porous prepolymer polyamide pellets according to claim 1, wherein said polyamide pellets are produced by compressing prepolymer particles having a number-average molecular weight of less than about 10,000 into pellets.
Claim 4
Dependent Claim
38 words
Compressed porous prepolymer polyamide pellets according to claim 1 having a substantially cylindrical shape with a diameter of between about 1.5 mm to about 5 mm and a length of between about 3 mm and about 10 mm.
Claim 5
Dependent Claim
17 words
Compressed porous prepolymer polyamide pellets according to claim 1 having porosity between 15 and 0.5 vol. %
Claim 6
Dependent Claim
17 words
Compressed porous prepolymer polyamide pellets according to claim 1 having porosity between 10 and 1 vol. %.
Claim 7
Dependent Claim
38 words
Compressed porous prepolymer polyamide pellets according to claim 2 having a substantially cylindrical shape with a diameter of between about 1.5 mm to about 5 mm and a length of between about 3 mm and about 10 mm.
Claim 8
Dependent Claim
17 words
Compressed porous prepolymer polyamide pellets according to claim 2 having porosity between 15 and 0.5 vol. %
Claim 9
Dependent Claim
17 words
Compressed porous prepolymer polyamide pellets according to claim 2 having porosity between 10 and 1 vol. %.
Claim 10
Dependent Claim
63 words
After-condensed high molecular weight polyamide compressed pellets for use in the production of spinned, molded or extruded articles, said polyamide pellets consisting essentially of repeating units having the formula, --NH--(CH.sub.2).sub.4 --NH--CO--(CH.sub.2).sub.4 --CO--, said polyamide pellets having a size of between 1 mm and 20 mm, a porosity of between 0.1 and 20 vol. % and crushing strength of at least about 15 kg.
Claim 11
Dependent Claim
63 words
After-condensed high molecular weight polyamide compressed pellets for use in the production of spinned, molded or extruded articles, said polyamide pellets consisting essentially of repeating units having the formula, --NH--(CH.sub.2).sub.4 --NH--CO--(CH.sub.2).sub.4 --CO--, said polyamide pellets having a size of between 1 mm and 20 mm, a porosity of between 0.1 and 20 vol. % and crushing strength of at least about 15 kg.
Claim 12
Dependent Claim
38 words
After-condensed high molecular weight polyamide pellets according to claim 9, wherein said polyamide pellets are produced by compressing prepolymer particles having a number-average molecular weight of less than about 10,000 into pellets and then after-condensing said prepolymer pellets.
Claim 13
Dependent Claim
35 words
After-condensed high molecular weight polyamide pellets according to claim 9 having an approximately cylindrical shape with a diameter of between 1.5 mm and 5 mm and a length of between 3 mm and 10 mm.
Claim 14
Dependent Claim
18 words
After-condensed high molecular weight polyamide pellets according to claim 9 having porosity between 15 and 0.5 vol. %
Claim 15
Dependent Claim
18 words
After-condensed high molecular weight polyamide pellets according to claim 9 having porosity between 10 and 1 vol. %.
Claim 16
Dependent Claim
35 words
After-condensed high molecular weight polyamide pellets according to claim 10 having an approximately cylindrical shape with a diameter of between 1.5 mm and 5 mm and a length of between 3 mm and 10 mm.
Claim 17
Dependent Claim
18 words
After-condensed high molecular weight polyamide pellets according to claim 10 having porosity between 15 and 0.5 vol. %
Claim 18
Dependent Claim
18 words
After-condensed high molecular weight polyamide pellets according to claim 10 having porosity between 10 and 1 vol. %.
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) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |