US4266041A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of foamed plastics from polyolefins
Assignee: Dynamit Nobel AG
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Filing: 1979-11-30
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Granted: 1981-05-05
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Expires: 1999-11-30
Abstract
Abstract A process is described for the production of foamed plastics from polyolefins by peroxide crosslinking and foaming by means of a chemical foaming agent under conditions of normal pressure the improvement wherein said foaming is carried out in the additional presence of a finely divided magnesium oxide and/or magnesium hydroxide and/or magnesium-hydroxide carbonate.
Inventors
- 👤 Werner Kuhnel
- 👤 Paul Spielau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:57
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/10; C08J9/101; C08J2323/00; C08J2323/02; Y; Y10; Y10S; Y10S521/00; Y10S521/909
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
71 words
In a process for the production of foamed plastics from polyolefins by peroxide crosslinking and foaming by means of a chemically decomposing foaming agent under conditions of normal pressure the improvement wherein said foaming is carried out in the additional presence of less than 13 weight percent, based on the amount of foaming agent, of magnesium oxide and/or magnesium hydroxide and/or magnesium-hydroxide carbonate having a bulk density of under 800 g/l.
Claim 2
Dependent Claim
71 words
In a process for the production of foamed plastics from polyolefins by peroxide crosslinking and foaming by means of a chemically decomposing foaming agent under conditions of normal pressure the improvement wherein said foaming is carried out in the additional presence of less than 13 weight percent, based on the amount of foaming agent, of magnesium oxide and/or magnesium hydroxide and/or magnesium-hydroxide carbonate having a bulk density of under 800 g/l.
Claim 3
Dependent Claim
27 words
A process according to claim 1 wherein the magnesium compound is present in the mixture to be foamed in an amount of less than 5 weight percent.
Claim 4
Dependent Claim
29 words
A process according to claim 1 wherein the magnesium oxide used is a caustic magnesium oxide with over 84 weight percent MgO, and preferably over 88 weight percent MgO.
Claim 5
Dependent Claim
26 words
A process according to claim 1 wherein the foaming agent used is one whose decomposition or decomposition range is about 190° C. or higher, preferably azodicarbonamide.
Claim 6
Dependent Claim
34 words
A process according to claim 2 wherein said magnesium compound is present in the mixture to be foamed in an amount of less than 3.5 weight percent, based on the amount of foaming agent.
Claim 7
Dependent Claim
35 words
A process according to claim 2 wherein said magnesium compound is present in the mixture to be foamed in an amount of between 0.5 and 3.3 weight percent, based on the amount of foaming agent.
Claim 8
Dependent Claim
13 words
A process according to claim 1 wherein said magnesium compound is magnesium oxide.
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) | 1984-05-04 | 1984-11-03 | 1985-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-04 | 1988-11-03 | 1989-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-04 | 1992-11-03 | 1993-05-05 | $7700.00 | Window Closed / Lapsed |