US5162381A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing thermalplastic foam
Assignee: Honeywell International Inc
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Filing: 1991-12-10
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Granted: 1992-11-10
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Expires: 2011-12-10
Abstract
Abstract This invention relates to a novel, environmentally acceptable blowing agent and blowing agent blends and a process for producing thermalplastic, and particularly polyolefin foams using the environmentally acceptable blowing agent(s). The blowing agents of the present invention comprise difluoromethane and optionally a second blowing agent component which is nonflammable and possesses good blowing agent properties. Polyolefin foam is made by mixing a polyolefin resin and the blowing agent and introducing the resin/blowing agent mixture into a zone of lower pressure.
Inventors
- 👤 Robert G. Richard
- 👤 Ian R. Shankland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:20
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; C08J9/127; C08J9/14; C08J9/143; C08J9/144; C08J9/146; C08J9/149; C08J2203/00; C08J2203/14; C08J2203/142; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S521/00; Y10S521/91
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
76 words
In the process for making polyolefin foam comprising blending heat plasticized polyolefin resin with a volatile blowing agent and introducing the resin/volatile blowing agent blend into a zone of lower pressure to cause foaming; the improvement which comprises using difluoromethane and at least one second blowing agent component which is non-flammable and possesses foam enhancing qualities as said volatile blowing agent selected from the group consisting of a hydrofluorocarbon, a fluorocarbon, sulfur hexafluoride or carbon dioxide.
Claim 2
Dependent Claim
76 words
In the process for making polyolefin foam comprising blending heat plasticized polyolefin resin with a volatile blowing agent and introducing the resin/volatile blowing agent blend into a zone of lower pressure to cause foaming; the improvement which comprises using difluoromethane and at least one second blowing agent component which is non-flammable and possesses foam enhancing qualities as said volatile blowing agent selected from the group consisting of a hydrofluorocarbon, a fluorocarbon, sulfur hexafluoride or carbon dioxide.
Claim 3
Dependent Claim
11 words
The process of claim 1 wherein said polyolefin foam is polystyrene.
Claim 4
Dependent Claim
33 words
The process of claim 1 wherein said at least one second blowing agent component is chosen from the group consisting of 1-chloro-1,2,2,2-tetrafluoroethane, pentafluoroethane, chlorodifluoromethane, 1,1,1,2-tetrafluoroethane, sulfur hexafluoride, trifluoromethane, hexafluoroethane, carbon dioxide and octafluoropropane.
Claim 5
Dependent Claim
33 words
The process of claim 1 wherein said at least one second blowing agent is present in an amount between about 6 mol% and about 99 mol%, such that said blowing agent is non-flammable.
Claim 6
Dependent Claim
13 words
The process of claim 3 wherein said second blowing agent component is 1-chloro-1,2,2,2-tetrafluoroethane.
Claim 7
Dependent Claim
29 words
The process of claim 5 wherein said 1-chloro-1,2,2,2-tetrafluoroethane is present in an amount between about 28 mol % to about 99 mol%, such that said blowing agent is non-flammable.
Claim 8
Dependent Claim
33 words
The process of claim 2 wherein said at least one second blowing agent component is chosen from the group consisting of 1-chloro-1,2,2,2-tetrafluoroethane, pentafluoroethane, chlorodifluoromethane, 1,1,1,2-tetrafluoroethane, sulfur hexafluoride, trifluoromethane, hexafluoroethane, carbon dioxide and octafluoropropane.
Claim 9
Dependent Claim
33 words
The process of claim 7 wherein said at least one second blowing agent is present in an amount between about 6 mol% and about 99 mol%, such that said blowing agent is non-flammable.
Claim 10
Dependent Claim
13 words
The process of claim 2 wherein said second blowing agent component is 1-chloro-1,2,2,2-tetrafluoroethane.
Claim 11
Dependent Claim
30 words
The process of claim 9 wherein said 1-chloro-1,2,2,2-tetrafluoroethane is present in an amount between about 28 mol % to about 99 mol %, such that said blowing agent is non-flammable.
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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) | 1995-11-10 | 1996-05-11 | 1996-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-10 | 2000-05-11 | 2000-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-10 | 2004-05-11 | 2004-11-10 | $7700.00 | Window Closed / Lapsed |