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US4537935A Expired / Lapsed US ⏱️ 0.0 years remaining

Composition for cold drawn film

Assignee: Asahi Dow Ltd
•
Filing: 1984-10-29
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Granted: 1985-08-27
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Expires: 2004-10-29
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Abstract

Abstract A composition for shrinkable film which excels in heat-sealability, transparency, strength, and particularly 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 homogeneous 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 2026-11-07 16:00
CPC Classifications
B; B29; B29C; B29C61/00; B29C61/003; C; C08; C08L; C08L23/00; C08L23/02; B29C48/00; B29C48/001; B29C48/0018; B29C48/03; B29C48/09; B29C48/10; C08L23/04; C08L23/08; C08L23/0846; C08L23/0853; C08L23/10; C08L23/16

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 83 words
A composition consisting essentially of 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, with vinyl ester monomers, (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 crystalline polypropylene and the ratios of the components are such as to satisfy 0.07≦B/(A+B)≦0.70 and 0.07≦C/(A+B)≦0.8.
Claim 2
Dependent Claim 83 words
A composition consisting essentially of 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, with vinyl ester monomers, (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 crystalline polypropylene and the ratios of the components are such as to satisfy 0.07≦B/(A+B)≦0.70 and 0.07≦C/(A+B)≦0.8.
Claim 3
Dependent Claim 14 words
The composition according to claim 1, wherein the component (A) is ethylene-vinyl acetate copolymer.
Claim 4
Dependent Claim 27 words
The composition according to claim 2, wherein the ethylene-vinyl acetate copolymer has a vinyl acetate group content in the range of from 3 to 30% by weight.
Claim 5
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 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 40 mol%.
Claim 7
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 8
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 9
Dependent Claim 28 words
The composition according to claim 2, wherein the ethylene-α-olefin copolymer as the component (B) has a polyene copolymerized in addition to the main components of ethylene and α-olefin.
Claim 10
Dependent Claim 29 words
The composition according to claim 8, wherein the polyene contains not more than 5 mol% of a non-conjugate diene selected from the group consisting of hexadiene and norbornene derivatives.
Claim 11
Dependent Claim 14 words
A composition according to claim 1 wherein the ratio B/(A+B)=0.2 and the ratio C/(A+B)=0.8.

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) 1988-08-26 1989-02-25 1989-08-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-08-26 1993-02-25 1993-08-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-08-26 1997-02-25 1997-08-27 $7700.00 Window Closed / Lapsed

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