Patent US4022719A successfully refreshed from Google Patents.
US4022719A
Expired / Lapsed
US
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Process for producing polyamide foam
Assignee: Bridgestone Corp
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Filing: 1975-05-12
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Granted: 1977-05-10
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Expires: 1995-05-12
Abstract
Abstract Methods of preparing polyamide foam comprising polymerizing and foaming a mixture of one or more specified lactams, a basic alkali metal lactam catalyst, an alkyl isocyanate activator and a foaming agent at a temperature above the melting point of the lactam, and below the melting point of the polyamide foam thus produced.
Inventors
- 👤 Toru Okuyama
- 👤 Susumu Muta
- 👤 Suminobu Kurahashi
- 👤 Shigetake Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:51
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08G; C08G69/00; C08G69/02; C08G69/08; C08G69/14; C08G69/16; C08G69/18; C08J9/12; C08J9/14; C08J2377/00; C08J2377/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
80 words
A process for producing a polyamide foam which comprises polymerizing a mixture of (1) ε-caprolactam, dodecanolactam, or a mixture thereof at a temperature of from 120° to 160° C, (2) sodium lactam as catalyst and (3) an activator selected from the group consisting of hexamethylene diisocyanate, m-xylylene diisocyanate and hydrogenated diphenylemethane-4,4'-diisocyanate, the molar ratio of catalyst/lactam being in the range of from 1/10 to 1/200 and the molar ratio of activator/catalyst being in the range of from 0.5/1 to 2.5/1.
Claim 2
Dependent Claim
80 words
A process for producing a polyamide foam which comprises polymerizing a mixture of (1) ε-caprolactam, dodecanolactam, or a mixture thereof at a temperature of from 120° to 160° C, (2) sodium lactam as catalyst and (3) an activator selected from the group consisting of hexamethylene diisocyanate, m-xylylene diisocyanate and hydrogenated diphenylemethane-4,4'-diisocyanate, the molar ratio of catalyst/lactam being in the range of from 1/10 to 1/200 and the molar ratio of activator/catalyst being in the range of from 0.5/1 to 2.5/1.
Claim 3
Dependent Claim
13 words
A process according to claim 1 wherein the activator/catalyst ratio is about 1.5:1.
Claim 4
Dependent Claim
13 words
A process according to claim 1 wherein a volatile foaming agent is used.
Claim 5
Dependent Claim
13 words
A process according to claim 1 wherein a decomposition-type foaming agent is used.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-09 | 1980-11-08 | 1981-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-09 | 1984-11-08 | 1985-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-09 | 1988-11-08 | 1989-05-10 | $7700.00 | Window Closed / Lapsed |