Patent US5170198A successfully refreshed from Google Patents.
Patent US6535617B1 successfully refreshed from Google Patents.
Patent US4028287A successfully refreshed from Google Patents.
US4028287A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for continuous preparation of a foam polyamide
Assignee: Bridgestone Corp
•
Filing: 1975-06-04
•
Granted: 1977-06-07
•
Expires: 1995-06-04
Abstract
Abstract Method for the preparation of a foam polyamide in which the lactam together with a basic catalyst at a temperature above the melting point of the lactam is mixed with the promoter and foaming agent in a mixing vessel at ambient temperature while subjecting the mix to violent agitation to initiate polymerization, and the mix is discharged into a container for completion of the reaction before polymerization is more than 10% complete.
Inventors
- 👤 Shigetake Sato
- 👤 Suminobu Kurahashi
- 👤 Toru Okuyama
- 👤 Noboru Hamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:09
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; B; B01; B01J; B01J19/00; B01J19/18; C08G; C08G69/00; C08G69/02; C08G69/08; C08G69/14; C08G69/16; C08G69/18; B01J2219/00; B01J2219/00049; B01J2219/00164; B01J2219/00168; B01J2219/00186; B01J2219/18; B01J2219/185; C08J2377/00; C08J2377/02
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
123 words
A process for the preparation of a polyamide foam by ring-opening polymerization of a polymerizable lactam in the presence of a basic catalyst, a promoter and a foaming agent which comprises the steps of: A. preparing a first composition containing the lactam and the catalyst at a temperature above the melting point of the lactam; B. preparing a second liquid composition containing the promoter and the foaming agent at room temperature without heating and maintaining it at room temperature; C. mixing said compositions at their preparation temperatures in a mixing vessel with violent agitation to initiate polymerization; D. discharging the reacting mixture into a container before polymerization of the lactam is more than 10% complete, and allowing the polymerization to run to completion.
Claim 2
Dependent Claim
123 words
A process for the preparation of a polyamide foam by ring-opening polymerization of a polymerizable lactam in the presence of a basic catalyst, a promoter and a foaming agent which comprises the steps of: A. preparing a first composition containing the lactam and the catalyst at a temperature above the melting point of the lactam; B. preparing a second liquid composition containing the promoter and the foaming agent at room temperature without heating and maintaining it at room temperature; C. mixing said compositions at their preparation temperatures in a mixing vessel with violent agitation to initiate polymerization; D. discharging the reacting mixture into a container before polymerization of the lactam is more than 10% complete, and allowing the polymerization to run to completion.
Claim 3
Dependent Claim
11 words
A process in claim 1 carried out in a continuous manner.
Claim 4
Dependent Claim
19 words
A process as in claim 1 wherein the temperature of the first composition is from 70° to 180° C.
Claim 5
Dependent Claim
20 words
A process as in claim 1 wherein the reacting mixture is discharged before the reaction is more than 5% complete.
Claim 6
Dependent Claim
18 words
A process as in claim 1 wherein a portion of the lactam is dissolved in the second composition.
Claim 7
Dependent Claim
11 words
A process as in claim 1 wherein the lactam is ε-caprolactam.
Claim 8
Dependent Claim
25 words
A process as in claim 1 in which the amount of the basic catalyst is from about 1/5 - 1/500 mole per mole of lactam.
Claim 9
Dependent Claim
13 words
A process as in claim 1 in which the catalyst is sodium caprolactam.
Claim 10
Dependent Claim
24 words
A process as in claim 1 in which the amount of a promoter is from about 1/5 - 1/1000 mole per mole of lactam.
Claim 11
Dependent Claim
14 words
A process as in claim 1 in which the promoter is an aliphatic isocyanate.
Claim 12
Dependent Claim
13 words
A process as in claim 10 in which the promoter is hexamethylene diisocyanate.
Claim 13
Dependent Claim
39 words
The process according to claim 1 in which the foaming agent is selected from the group consisting of low boiling liquids which vaporize at the reaction temperature and compounds which decompose to form a gas at the reaction temperature.
Claim 14
Dependent Claim
15 words
A process as in claim 1 in which the foaming agent is toluene or n-hexane.
Claim 15
Dependent Claim
20 words
A process as in claim 1 in which the mixing vessel is equipped with an internal agitator and bottom outlet.
Claim 16
Dependent Claim
25 words
A process as in claim 1 in which at least one of the compositions contains at least one of a foam stabilizer and a pigment.
Claim 17
Dependent Claim
15 words
A process as in claim 15 in which the foam stabilizer is a silicone oil.
Claim 18
Dependent Claim
76 words
A process as in claim 1 in which the lactam is ε-caprolactam, its temperature is from 120° - 160° C, from 1/20 - 1/100 mole of sodium caprolactam for each mole of ε-caprolactam is used as the basic catalyst, from 1/10 - 1/100 mole of hexamethylene diisocyanate for each mole of ε-caprolactam is used as the foaming agent, and the reacting mixture is discharged from the mixing vessel before the reaction is more than 5% complete.
References Cited (Backward Citations)
US3547836A
Cited
US3207713A
Cited
US3234152A
Cited
US3274132A
Cited
US3316221A
Cited
US3322696A
Cited
US3332895A
Cited
US3376237A
Cited
US3449269A
Cited
US3591533A
Cited
US3574146A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-06 | 1980-12-06 | 1981-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-06 | 1984-12-06 | 1985-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-06 | 1988-12-06 | 1989-06-07 | $7700.00 | Window Closed / Lapsed |