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US4820557A Expired / Lapsed US ⏱️ 0.0 years remaining

Thermoplastic packaging film of low I10 /I2

Assignee: Cryovac LLC
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Filing: 1987-09-17
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Granted: 1989-04-11
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Expires: 2007-09-17
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Abstract

Abstract Disclosed is a high abuse-resistance film suitable for making bags and pouches. The film has at least one layer comprising a linear copolymer of ethylene and an alpha-olefin with a density of about 0.935 g/cc or less. The copolymer has a comparatively lower I10/I2 ratio than the corresponding ethylene/alpha-olefin with the same comonomer and essentially the same density and essentially the same melt index at condition 190/2.16.

Inventors

  • 👤 Thomas C. Warren

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 13:30
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/30; B32B27/306; B32B27/308; B32B27/32; G; G02; G02B; G02B6/00; G02B6/44; G02B6/4439; G02B6/4471; G02B6/4476; B32B2307/00; B32B2307/50; B32B2307/558; B32B2307/70; B32B2307/732; B32B2307/734; B32B2307/736; B32B2323/00; B32B2323/04; B32B2323/043; B32B2323/046; B32B2323/10; B32B2331/00; B32B2331/04; B32B2439/00; B32B2439/40; B32B2439/46; B32B2553/00; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/1331; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 73 words
A heat-shrinkable packaging film of improved abuse resistance comprising at least one layer of a linear copolymer of ethylene and an alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I 10 /I 2 melt flow ratio of about 7.2 when said alpha-olefin is octene or (b) a low I 10 /I 2 melt flow ratio of about 9.9 and a comonomer of hexene.
Claim 2
Dependent Claim 73 words
A heat-shrinkable packaging film of improved abuse resistance comprising at least one layer of a linear copolymer of ethylene and an alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I 10 /I 2 melt flow ratio of about 7.2 when said alpha-olefin is octene or (b) a low I 10 /I 2 melt flow ratio of about 9.9 and a comonomer of hexene.
Claim 3
Dependent Claim 28 words
The film of claim 1, wherein said copolymer of ethylene and an alpha-olefin of low I 10 /I 2 ratio is in blend with another polymer compatible therewith.
Claim 4
Dependent Claim 107 words
The film of claim 2, wherein said layer of ethylene/alpha-olefin copolymer having a low I 10 /I 2 ratio further includes up to 50% by weight, based on the layer composition, of a polymer which is compatible with said ethylene/alpha-olefin copolymer and is selected from ethylene/alkyl-acrylate copolymer, high density polyethylene (HDPE), linear medium density polyethylene (LMDPE), linear high density polyethylene (LHDPE), low density polyethylene (LDPE), medium density polyethyle (MDPE), ethylene/vinyl acetate (EVA), acid-modified EVA, polypropylene, ethylene/propylene copolymers, copolymers of an alpha-olefin having the formula RHC═CH 2 wherein R is H or C 1 to C 8 alkyl and an alpha, beta-ethylenically unsaturated carboxylic acid, and mixtures thereof.
Claim 5
Dependent Claim 16 words
The film of claim 1, wherein said film is a multilayer film including a barrier layer.
Claim 6
Dependent Claim 36 words
The film of claim 1, wherein said film is a multi-layer film and at least one layer of copolymer of ethylene/alpha-olefin of low I 10 /I 2 ratio is an interior layer of the multi-layer film.
Claim 7
Dependent Claim 32 words
The film of claim 1, wherein said at least one layer of ethylene/alpha-olefin copolymer of low I 10 /I 2 ratio has been irradiated at a dosage up to about 20 MR.
Claim 8
Dependent Claim 20 words
A bag formed from the film of claim 1, said bag having end seal(s), side seal(s), or a combination thereof.
Claim 9
Dependent Claim 19 words
The bag of claim 7, wherein the film of the bag is a multi-layer film including a barrier layer.
Claim 10
Dependent Claim 29 words
The bag of claim 8, wherein at least one layer of copolymer of ethylene/alpha-olefin of low I 10 /I 2 ratio is an interior layer of the multi-layer film.
Claim 11
Dependent Claim 15 words
The bag of claim 7, wherein the film of the bag is a heat-shrinkable film.
Claim 12
Dependent Claim 76 words
A thermoplastic, heat-shrinkable packaging film of improved abuse resistance comprising (I) a layer of a linear copolymer of ethylene and an alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I 10 /I 2 ratio of about 7.2 when said alpha-olefin is octene or (b) a low I 10 /I 2 ratio of about 9.9 and a comonomer of hexene, and (II) a layer of barrier material.
Claim 13
Dependent Claim 76 words
A thermoplastic, heat-shrinkable packaging film of improved abuse resistance comprising (I) a layer of a linear copolymer of ethylene and an alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I 10 /I 2 ratio of about 7.2 when said alpha-olefin is octene or (b) a low I 10 /I 2 ratio of about 9.9 and a comonomer of hexene, and (II) a layer of barrier material.
Claim 14
Dependent Claim 153 words
A heat-shrinkable packaging film of improved abuse resistance comprising a layer of a linear copolymer of ethylene and an alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I 10 /I 2 melt flow ratio of about 7.2 and a comonomer of octene or (b) a low I 10 /I 2 melt flow ratio of about 9.9 when said alpha-olefin is hexene, said ethylene/alpha-olefin copolymer having a comparatively lower I 10 /I 2 ratio than the corresponding ethylene/alpha-olefin copolymer with the same comonomer and essentially the same density but a comparatively higher I 10 /I 2 ratio, said packaging film exhibiting better abuse resistance than the corresponding film made of the ethylene/alpha-olefin copolymer having the higher I 10 /I 2 ratio, wherein said lower I 10 /I 2 ratio and said higher I 10 /I 2 ratio differ by an amount above about 0.5.
Claim 15
Dependent Claim 153 words
A heat-shrinkable packaging film of improved abuse resistance comprising a layer of a linear copolymer of ethylene and an alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I 10 /I 2 melt flow ratio of about 7.2 and a comonomer of octene or (b) a low I 10 /I 2 melt flow ratio of about 9.9 when said alpha-olefin is hexene, said ethylene/alpha-olefin copolymer having a comparatively lower I 10 /I 2 ratio than the corresponding ethylene/alpha-olefin copolymer with the same comonomer and essentially the same density but a comparatively higher I 10 /I 2 ratio, said packaging film exhibiting better abuse resistance than the corresponding film made of the ethylene/alpha-olefin copolymer having the higher I 10 /I 2 ratio, wherein said lower I 10 /I 2 ratio and said higher I 10 /I 2 ratio differ by an amount above about 0.5.
Claim 16
Dependent Claim 99 words
A thermoplastic, mult-layer, heat-shrinkable packaging film having excellent abuse resistance, comprising in direct surface-to-surface contact at least the 4-layer structure: an outside polymer layer, a barrier layer, and interior layer, a heat sealing layer, wherein said interior layer comprises a linear copolymer of ethylene and an a alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I 10 /I 2 melt flow ratio of about 7.2 when said alpha-olefin is octene or (b) a low I 10 /I 2 melt flow ratio of about 9.9 and a comonomer of hexene.
Claim 17
Dependent Claim 99 words
A thermoplastic, mult-layer, heat-shrinkable packaging film having excellent abuse resistance, comprising in direct surface-to-surface contact at least the 4-layer structure: an outside polymer layer, a barrier layer, and interior layer, a heat sealing layer, wherein said interior layer comprises a linear copolymer of ethylene and an a alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I 10 /I 2 melt flow ratio of about 7.2 when said alpha-olefin is octene or (b) a low I 10 /I 2 melt flow ratio of about 9.9 and a comonomer of hexene.
Claim 18
Dependent Claim 97 words
The film of claim 13, wherein said interior layer further includes up to 50% by weight, based on the layer composition, of a polymer which is compatible with said ethylene/alpha-olefin copolymer and is selected from ethylene/alkyl-acrylate copolymer, high density polyethylene (HDPE), linear medium density polyethylene (LMDPE), linear high density polyethylene (LHDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), ethylene/vinyl acetate (EVA), acid-modified EVA, polypropylene, ethylene/propylene copolymers, copolymers of an alpha-olefin having the formula RHC═CH 2 wherein R is H or C 1 to C 8 alkyl and an alpha, beta-ethylenically unsaturated carboxylic acid, and mixtures thereof.
Claim 19
Dependent Claim 30 words
The film of claim 13, wherein said interior layer of ethylene/alpha-olefin having a low I 10 /I 2 ratio has been irradiated at a dosage up to about 20 MR.

References Cited (Backward Citations)

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US4064296A Cited
US4532189A Cited
US4457960A Cited
US4525257A Cited
US4639428A Cited
US4640856A Cited
US4670413A Cited
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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) 1992-04-10 1992-10-10 1993-04-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-04-10 1996-10-10 1997-04-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-04-10 2000-10-10 2001-04-11 $7700.00 Window Closed / Lapsed

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