← Back to Patent Explorer
US4336350A Expired / Lapsed US ⏱️ 0.0 years remaining

Cold drawn film made of an olefin polymer blend composition

Assignee: Asahi Kasei Corp
•
Filing: 1979-07-25
•
Granted: 1982-06-22
•
Expires: 1999-07-25
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

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 polyolefin 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 2026-10-30 13:10
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: 18
Claim 1
Independent Claim 94 words
A cold drawn film having a tensile strength of not less than 5.0 kg/mm 2 and a haze of not more than 4.0% which film comprises a homogeneous blend of the combination of components (B)+(C) wherein the components of the composition are in amounts such as to satisfy 0.90≧B/(B+C)≧0.30 in terms of weight ratio; (B) is a thermoplastic elastomer having a density of not more than 0.91 g/cm 3 and made of an ethylene-α-olefin copolymer, and (C) is at least one selected from the group consisting of crystalline polypropylene, high-density polyethylene and crystalline polybutene-1.
Claim 2
Dependent Claim 94 words
A cold drawn film having a tensile strength of not less than 5.0 kg/mm 2 and a haze of not more than 4.0% which film comprises a homogeneous blend of the combination of components (B)+(C) wherein the components of the composition are in amounts such as to satisfy 0.90≧B/(B+C)≧0.30 in terms of weight ratio; (B) is a thermoplastic elastomer having a density of not more than 0.91 g/cm 3 and made of an ethylene-α-olefin copolymer, and (C) is at least one selected from the group consisting of crystalline polypropylene, high-density polyethylene and crystalline polybutene-1.
Claim 3
Dependent Claim 31 words
The film according to claim 1, 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 4
Dependent Claim 31 words
The film according to claim 1, 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 5
Dependent Claim 63 words
The film according to claim 1, 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-olefins having from 3 to 12 carbon atoms.
Claim 6
Dependent Claim 33 words
The film according to claim 1, 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 7
Dependent Claim 28 words
The film according to claim 1, 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 8
Dependent Claim 29 words
The film according to claim 6, wherein the polyene contains not more than 5 mol% of a non-conjugate diene selested from the group consisting of hexadiene and norbornene derivatives.
Claim 9
Dependent Claim 25 words
The film according to claim 1, wherein the component (C) is a rigid polymer having a Vicat softening point of not less than 100° C.
Claim 10
Dependent Claim 33 words
The film according to claim 1, wherein the component (C) is either a crystalline polypropylene or a crystalline copolymer of propylene with ethylene contained in an amount of not more than 10 mol%.
Claim 11
Dependent Claim 25 words
The film according to claim 1, wherein the components of the composition are in amounts such as to satisfy 0.87≧B/(B+C)≧0.40 in terms of weight ratio.
Claim 12
Dependent Claim 37 words
The film according to claim 1, wherein the composition which constitutes the film has an insoluble gel content of from 60 to 0% by weight in boiling xylene and a melt index of not more than 10.
Claim 13
Dependent Claim 37 words
The film according to claim 1, wherein the composition which constitutes the film has an insoluble gel content of from 50 to 0% by weight in boiling xylene and a melt index of not more than 5.
Claim 14
Dependent Claim 41 words
The film according to claim 1, wherein the composition which constitutes the film has been crosslinked and has an insoluble gel content of from 40 to 0% by weight in boiling xylene and a melt index of not more than 0.2.
Claim 15
Dependent Claim 22 words
The film according to claim 1, wherein the film has a heat shrink tension of not less than 50 g/mm 2 .
Claim 16
Dependent Claim 25 words
The film according to claim 1, wherein the temperature at which the film exhibits a heat shrinkage of 20% is not more than 85° C.
Claim 17
Dependent Claim 25 words
The film according to claim 1, wherein the temperature at which the film exhibits a heat shrinkage of 20% is not more than 75° C.
Claim 18
Dependent Claim 17 words
The film according to claim 1, wherein the film has a Haze of not more than 3.0%.

References Cited (Backward Citations)

CA798416A Cited
GB924243A Cited
GB1046254A Cited
GB1037819A Cited
US3407253A Cited
GB1163053A Cited
GB1224035A Cited
GB1402049A Cited
GB1523447A Cited
US4031169A Cited
US4036912A Cited
US4087485A Cited
US4186240A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-06-21 1985-12-21 1986-06-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-06-21 1989-12-21 1990-06-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-06-21 1993-12-21 1994-06-22 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag