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US4643928A
Expired / Lapsed
US
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Coextrusion multi-layer tubular film
Assignee: Idemitsu Petrochemical Co Ltd
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Filing: 1984-11-23
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Granted: 1987-02-17
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Expires: 2004-11-23
Abstract
Abstract A coextrusion multi-layer tubular film comprising: an outer layer comprises a linear ethylene α-olefin copolymer having a density of from 0.900 to 0.945 gram per cubic centimeter; and an inner layer made of (i) a polypropylene-based resin or (ii) a resin composition comprising from 60 to 98% by weight of a polypropylene-base resin and from 40 to 2% of an ethylene α-olefin copolymer having a density of from 0.850 to 0.945 gram per cubic centimeter; the ratio of said outer layer to said inner layer being from 50:50 to 97:3.
Inventors
- 👤 Masakatsu Kimura
- 👤 Osamu Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:47
CPC Classifications
B; B32; B32B; B32B1/00; B32B1/08; B32B27/00; B32B27/32; B29; B29C; B29C48/00; B29C48/03; B29C48/09; B29C48/10; B29C48/14; B29C48/147; B29C48/1472; B32B27/06; B32B27/08; B32B27/322; C; C08; C08L; C08L23/00; C08L23/02; C08L23/10; C08L23/12; B29C2791/00; B29C2791/004; B29C2791/007; B32B2307/00; B32B2307/70; B32B2307/72; B32B2323/00; B32B2323/10; B32B2439/00; B32B2439/70; C08L23/04; C08L23/08; C08L23/0807; C08L23/0815; C08L23/16; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1334; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
91 words
A coextrusion multi-layer tubular film comprising: an outer layer comprising a linear ethylene α-olefin copolymer having a density of from 0.900 to 0.945 gram per cubic centimeter; and an inner layer made of (i) a polypropylene-base resin or (ii) a resin composition comprising from 70 to 97% by weight of a polypropylene-base resin and from 30 to 3% of an ethylene α-olefin copolymer having a density of from 0.850 to 0.945 gram per cubic centimeter; and the ratio of said outer layer to said inner layer being from 70:30 to 95:5.
Claim 2
Dependent Claim
91 words
A coextrusion multi-layer tubular film comprising: an outer layer comprising a linear ethylene α-olefin copolymer having a density of from 0.900 to 0.945 gram per cubic centimeter; and an inner layer made of (i) a polypropylene-base resin or (ii) a resin composition comprising from 70 to 97% by weight of a polypropylene-base resin and from 30 to 3% of an ethylene α-olefin copolymer having a density of from 0.850 to 0.945 gram per cubic centimeter; and the ratio of said outer layer to said inner layer being from 70:30 to 95:5.
Claim 3
Dependent Claim
35 words
The film as claimed in claim 1, wherein the linear ethylene α-olefin copolymer constituting the outer layer contains from 1 to 20 percent by weight of an α-olefin having from 3 to 20 carbon atoms.
Claim 4
Dependent Claim
36 words
The film as claimed in claim 1, wherein the polypropylene-base resin is a propylene homopolymer, or a block or random copolymer of propylene and 20 percent by weight or less of one or more other α-olefins.
Claim 5
Dependent Claim
60 words
The film as claimed in claim 1, wherein said inner layer comprises said polypropylene-base resin and said ethylene α-olefin copolymer, and said ethylene α-olefin copolymer is a linear ethylene α-olefin copolymer containing from 1 to 20 percent by weight of an α-olefin having from 3 to 20 carbon atoms or ethylene α-olefin copolymer of low-crystallinity or which is (b) non-crystalline.
Claim 6
Dependent Claim
34 words
The film as cliamed in claim 4, wherein said ethylene α-olefin copolymer is said low-crystalline or non-crystalline ethylene and is a copolymer of ethylene and an α-olefin having from 3 to 12 carbon atoms.
Claim 7
Dependent Claim
27 words
The film as claimed in claim 4, wherein the ethylene α-olefin copolymer is a copolymer having a density of from 0.850 to 0.910 gram per cubic centimeter.
Claim 8
Dependent Claim
36 words
The film as claimed in claim 2, wherein the polypropylene-base resin is a propylene homopolymer, or a block or random copolymer of propylene and 20 percent by weight or less of one or more other α-olefins.
Claim 9
Dependent Claim
61 words
The film as claimed in claim 2, wherein said inner layer comprises said polypropylene-base resin and said ethylene α-olefin copolymer, and said ethylene α-olefin copolymer is a linear ethylene α-olefin copolymer containing from 1 to 20 percent by weight of an α-olefin having from 3 to 20 carbon atoms or ethylene α-olefin copolymer of (a) low-crystallinity or which is (b) non-crystalline.
Claim 10
Dependent Claim
30 words
The film as claimed in claim 8, wherein said inner layer comprises from 70 to 97% of said polypropylene-base resin and from 30 to 3% of said ethylene α-olefin copolymer.
Claim 11
Dependent Claim
27 words
The film as claimed in claim 8, wherein the ethylene α-olefin copolymer is a copolymer having a density of from 0.850 to 0.910 gram per cubic centmeter.
Claim 12
Dependent Claim
30 words
The film as claimed in claim 10, wherein said inner layer comprises from 70 to 97% of said polypropylene-base resin and from 30 to 3% of said ethylene α-olefin copolymer.
Claim 13
Dependent Claim
30 words
The film as claimed in claim 1, wherein said inner layer comprises from 70 to 97% of said polypropylene-base resin and from 30 to 3% of said ethylene α-olefin copolymer.
Claim 14
Dependent Claim
45 words
The film as claimed in claim 1, wherein said polypropylene-base resin has a density of from 0.895 to 0.915 gram per cubic centimeter, a melting point of from 130° to 175° C. and a melt index of from 1.0 to 15 grams per 10 minutes.
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) | 1990-02-16 | 1990-08-18 | 1991-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-16 | 1994-08-18 | 1995-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-16 | 1998-08-18 | 1999-02-17 | $7700.00 | Window Closed / Lapsed |