Patent US4020025A successfully refreshed from Google Patents.
US4020025A
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Extrudable foamable composition comprising an olefin polymer, a styrene polymer and a hydrogenated styrene butadiene block copolymer
Assignee: BASF SE
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Filing: 1976-05-17
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Granted: 1977-04-26
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Expires: 1996-05-17
Abstract
Abstract Foams of mixtures of polyolefins and styrene polymers are produced by mixing the polymers with low-boiling expanding agents in the presence of a hydrogenated styrene/butadiene block polymer or a graft polymer of styrene on a polyolefin at temperatures above the softening point of the polymer mixture and under a pressure which prevents foaming of the mixture, followed by extrusion of the foamable mixture into a zone of lower pressure. The resulting foams are resistant to organic solvents.
Inventors
- 👤 Gerhard Zeitler
- 👤 Heinz Mueller-Tamm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:03
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; C08J2323/00; C08J2323/02; C08J2325/00; C08J2325/02; C08J2423/00; C08J2423/02; C08J2425/00; C08J2425/02; C08J2425/04; C08J2425/08; C08J2425/10; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S264/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
132 words
Extrusion-foamable composition of polyolefins and styrene polymers, which comprises a mixture of a. 5 to 90% by weight of ethylene or propylene polymers, b. 10 to 95% by weight of styrene polymer, c. 0.5 to 10% by weight, based on the combined weight of polyolefin (a) and styrene polymer (b), of a hydrogenated styrene/butadiene block polymer and d. 5 to 30% by weight, based on the combined weight of polyolefin (a) and styrene polymer (b), of at least one low-boiling expanding agent, said styrene polymer (b) having a higher molecular weight, measured by the melt index, than that of the polyolefin (a) and is finely dispersed in the polyolefin (a) forming the continuous phase, and said hydrogenated styrene/butadiene block polymer (c) having a viscosity average moleclar weight of from 3,000 to 800,000.
Claim 2
Dependent Claim
132 words
Extrusion-foamable composition of polyolefins and styrene polymers, which comprises a mixture of a. 5 to 90% by weight of ethylene or propylene polymers, b. 10 to 95% by weight of styrene polymer, c. 0.5 to 10% by weight, based on the combined weight of polyolefin (a) and styrene polymer (b), of a hydrogenated styrene/butadiene block polymer and d. 5 to 30% by weight, based on the combined weight of polyolefin (a) and styrene polymer (b), of at least one low-boiling expanding agent, said styrene polymer (b) having a higher molecular weight, measured by the melt index, than that of the polyolefin (a) and is finely dispersed in the polyolefin (a) forming the continuous phase, and said hydrogenated styrene/butadiene block polymer (c) having a viscosity average moleclar weight of from 3,000 to 800,000.
Claim 3
Dependent Claim
27 words
A composition as set forth in claim 1 wherein said styrene polymer is selected from the group consisting of polystyrene, poly(-methylstyrene) and copolymers of styrene with -methylstyrene.
Claim 4
Dependent Claim
25 words
A composition as set forth in claim 1 wherein the amount of said block polymer incorporated into the mixture is from two to eight percent.
Claim 5
Dependent Claim
20 words
A composition as set forth in claim 1 wherein molecular weight of said block polymer is from 10,000 to 100,000.
Claim 6
Dependent Claim
24 words
A composition as set forth in claim 4, wherein the proportion of styrene in said block polymer is from 10 to 80% by weight.
Claim 7
Dependent Claim
24 words
A composition as set forth in claim 4 wherein the proportion of styrene in said block polymer is from 30 to 60% by weight.
Claim 8
Dependent Claim
13 words
A composition as set forth in claim 6, wherein said polyolefin is polyethylene.
Claim 9
Dependent Claim
26 words
A composition as set forth in claim 6, wherein said polyolefin is a copolymer of ethylene containing from 55 to 90% by weight of ethylene units.
References Cited (Backward Citations)
US3250731A
Cited
US3810964A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |