Patent US4026834A successfully refreshed from Google Patents.
US4026834A
Expired / Lapsed
US
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Manufacture of polyamide foams
Assignee: BASF SE
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Filing: 1975-12-22
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Granted: 1977-05-31
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Expires: 1995-12-22
Abstract
Abstract A process for the manufacture of polyamide foams by anionic polymerization of lactams, in which from 0.1 to 15% w/w tetrachloroethylene is added to the reaction mixture to be foamed. The resulting foams are very tough, even at low temperatures.
Inventors
- 👤 Claus Cordes
- 👤 Erich Strickle
- 👤 Josef Zendath
- 👤 Georg Nikolaus Simon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:20
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0014; C08J9/0019; C08G; C08G69/00; C08G69/02; C08G69/08; C08G69/14; C08G69/16; C08G69/18; C08K; C08K5/00; C08K5/02; C08L; C08L71/00; C08L77/00; C08L77/02; C08J2377/00; C08J2377/02
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
67 words
In a process for the manufacture of polyamide foams by the anionic polymerization of a lactam wherein said lactam is heated in the presence of a catalyst and an activator and the resultant polymer is foamed by means of a foaming agent, the improvement which comprises carrying out said polymerization in the presence of 0.1 to 15 and preferably from 0.5 to 5% by weight of tetrachloroethylene.
Claim 2
Dependent Claim
67 words
In a process for the manufacture of polyamide foams by the anionic polymerization of a lactam wherein said lactam is heated in the presence of a catalyst and an activator and the resultant polymer is foamed by means of a foaming agent, the improvement which comprises carrying out said polymerization in the presence of 0.1 to 15 and preferably from 0.5 to 5% by weight of tetrachloroethylene.
Claim 3
Dependent Claim
13 words
A process as claimed in claim 1, wherein the lactam used is ε-caprolactam.
References Cited (Backward Citations)
US3850890A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |