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US4481334A Expired / Lapsed US ⏱️ 0.0 years remaining

Composition for drawn film, cold drawn film made of said composition and process for manufacture of said film

Assignee: Asahi Kasei Corp
•
Filing: 1983-01-12
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Granted: 1984-11-06
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Expires: 2003-01-12
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Abstract

Abstract A composition for shrinkable film which excels in heat-sealability, transparency, strength, and particulaly low-temperature quick shrinking property and, therefore, suits production chiefly of packaging materials, a film made of the composition and a process for the manufacture of the film are disclosed. Specifically, the composition comprises one of the specific combinations of components (A), (B) and (C), i.e. the combinations of (A)+(B), (B)+(C) and (A)+(B)+(C), wherein (A) is non-rigid polyolefine resins such as ethylene vinyl acetate, (B) is an elastomer comprising a specific ethylene-α-olefin copolymer, and (C) is rigid polyolefin resins such as polypropylene. The packaging film excelling particularly in optical property, mechanical strength and low-temperature shrinking property is obtained by converting a homogenenous blend of the aforementioned composition, either in its crosslinked form or in its non-crosslinked form, into a tubular raw film, which is stretched at a temperature low enough for imparting a high orientation to the film. The process for the manufacture of this packaging film is also disclosed.

Inventors

  • 👤 Isao Yoshimura
  • 👤 Hideo Hata
  • 👤 Takashi Kaneko

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 03:13
CPC Classifications
C; C08; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/08; C08L23/0846; C08L23/0853; C08L23/10; C08L23/16

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 98 words
A composition comprising a homogeneous blend of one of the specific combinations of components, namely the combination of (A)+(B)+(C); wherein (A) is at least one selected from the group consisting of copolymers of ethylene with vinyl ester monomers, unsaturated aliphatic monocarboxylic acids and alkyl esters of said acids which are all copolymerizable with ethylene, (B) is an elastomer having a density of not more than 0.91 g/cm 3 and made of an ethylene-α-olefin copolymer, and (C) is composed of crystalline polypropylene and crystalline polybutene-1 and the ratios of the components are such as to satisfy 0.05≦B/(A+B)≦0.90 and 0.05≦C/(A+B)≦2.0.
Claim 2
Dependent Claim 98 words
A composition comprising a homogeneous blend of one of the specific combinations of components, namely the combination of (A)+(B)+(C); wherein (A) is at least one selected from the group consisting of copolymers of ethylene with vinyl ester monomers, unsaturated aliphatic monocarboxylic acids and alkyl esters of said acids which are all copolymerizable with ethylene, (B) is an elastomer having a density of not more than 0.91 g/cm 3 and made of an ethylene-α-olefin copolymer, and (C) is composed of crystalline polypropylene and crystalline polybutene-1 and the ratios of the components are such as to satisfy 0.05≦B/(A+B)≦0.90 and 0.05≦C/(A+B)≦2.0.
Claim 3
Dependent Claim 36 words
The composition according to claim 1, wherein the component (A) is at least one selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymer, ethylene-ethyl acrylate copolymers, and ethylene-methyl methacrylate copolymer.
Claim 4
Dependent Claim 14 words
The composition according to claim 2, wherein the component (A) is ethylene-vinyl acetate copolymer.
Claim 5
Dependent Claim 27 words
The composition according to claim 3, wherein the ethylene-vinyl acetate copolymer has a vinyl acetate group content in the range of from 3 to 30% by weight.
Claim 6
Dependent Claim 31 words
The composition according to claim 2, wherein the ethylene-α-olefin copolymer as the component (B) has an ethylene group content of not more than 90 mol% and not less than 20 mol%.
Claim 7
Dependent Claim 31 words
The composition according to claim 2, wherein the ethylene-α-olefin copolymer as the component (B) has an ethylene group content of not more than 90 mol% and not less than 40 mol%.
Claim 8
Dependent Claim 63 words
The composition according to claim 2, wherein the elastomer as the component (B) is a non-rigid copolymer having a Vicat softening point of not more than 80° C. and a degree of crystallization of not more than 30%, wherein the α-olefin component contained therein is at least one member selected from the group consisting of α-olefin having from 3 to 12 carbon atoms.
Claim 9
Dependent Claim 33 words
The composition according to claim 2, wherein the elastomer as the component (B) is a random copolymer wherein the α-olefin component contained therein is selected from the group consisting of propylene and butene-1.
Claim 10
Dependent Claim 28 words
The composition according to claim 2, wherein the ethylene-α-olefin copolymer is the component (B) has a polyene copolymerized in addition to the main components of ethylene and α-olefin.
Claim 11
Dependent Claim 29 words
The composition according to claim 9, wherein the polyene contains not more than 5 mol% of a non-conjugate diene selected from the group consisting of hexadiene and norbornene derivatives.

References Cited (Backward Citations)

US3361852A Cited
US3941859A Cited
US4032600A Cited
US4131654A Cited
US4210579A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-11-06 1988-05-07 1988-11-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-11-06 1992-05-07 1992-11-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-11-06 1996-05-07 1996-11-06 $7700.00 Window Closed / Lapsed

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