EP0051480A1
Expired / Lapsed
EP
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Laminate films for heat-shrink packaging foodstuffs
Assignee: Kureha Corp
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Filing: 1981-10-30
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Granted: —
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Expires: 2001-10-30
Abstract
Abstract Problems with prior art laminate films used for heat-shrink packaging of foodstuffs, such as insufficient oil-and peel-resistance, are overcome by a laminate film comprising a center layer and two outermost layers with a respective adhesive layer between the center layer and each outermost layer, and being capable of exhibiting a rate of heat shrinkage at 90°C of more than 15%, the center layer consisting of a copolymer (I) of vinylidene chloride and both the outermost layers consisting of from 20 to 70% by weight of a copolymer (II) of ethylene and an alpha-olefin, the copolymer (II) having a crystalline melting point of 110 to 125°C, and from 80 to 30% by weight of a copolymer (III) of ethylene and vinyl acetate, the copolymer (III) having a crystalline melting point of 85 to 103°C, the content of copolymer (II) in the total amount of copolymers in both the outermost layers being less than 65% by weight.
Inventors
- 👤 Yoshiharu Nishimoto
- 👤 Kengo Yamazaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 01:48
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/30; B32B27/304; B32B27/32; B32B27/322; B32B7/00; B32B7/04; B32B7/12; B29; B29K; B29K2027/00; B29K2027/08; B32B2307/00; B32B2307/70; B32B2307/732; B32B2307/734; B32B2307/736; B32B2327/00; B32B2327/12; B32B2439/00; B32B2439/70; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/31504; Y10T428/31855; Y10T428/31931; Y10T428/31935
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
134 words
A laminate film comprising a center layer and two outermost layers with a respective adhesive layer between the center layer and each outermost layer,and being capable of exhibiting a rate of heat shrinkage at 90°C of more than 15%, the center layer consisting of a copolymer (I) of vinylidene chloride and both the outermost layers consisting of from 20 to 70% by weight of a copolymer (II) of ethylene and an alpha-olefin, the copolymer (II) having a crystalline melting point of 110 to 125°C, and from 80 to 30% by weight of a copolymer (III) of ethylene and vinyl acetate, the copolymer (III) having a crystalline melting point of 85 to 103°C, the content of copolymer (II) in the total amount of copolymers in both the outermost layers being less than 65% by weight.
Claim 2
Dependent Claim
134 words
A laminate film comprising a center layer and two outermost layers with a respective adhesive layer between the center layer and each outermost layer,and being capable of exhibiting a rate of heat shrinkage at 90°C of more than 15%, the center layer consisting of a copolymer (I) of vinylidene chloride and both the outermost layers consisting of from 20 to 70% by weight of a copolymer (II) of ethylene and an alpha-olefin, the copolymer (II) having a crystalline melting point of 110 to 125°C, and from 80 to 30% by weight of a copolymer (III) of ethylene and vinyl acetate, the copolymer (III) having a crystalline melting point of 85 to 103°C, the content of copolymer (II) in the total amount of copolymers in both the outermost layers being less than 65% by weight.
Claim 3
Dependent Claim
36 words
A laminate film according to claim 1, wherein said copolymer (I) comprises 65 to 95% by weight of vinylidene chloride and 35 to 5% by weight of at least one unsaturated monomer copolymerizable with vinylidene chloride..
Claim 4
Dependent Claim
31 words
A laminate film according to claim 1 or 2, wherein said copolymer (II) is a copolymer of ethylene and one or more alpha-olefins selected from butene-1, pentene-1, 4-methylpentene-1, hexene-1 and octene-1.
Claim 5
Dependent Claim
42 words
A laminate film according to any one of the preceding claims, wherein said copolymer (III) falls within the pentagon defined in Figure 1 of the accompanying drawings by the lines connecting the points of (W-I), (W-II),(X-II), (Z-III) and (Z-I) in that order.
Claim 6
Dependent Claim
34 words
A laminate film according to any one of the preceding claims, wherein each adhesive layer is polyethylene modified by a carboxylic acid or a copolymer of ethylene and vinyl acetate, or a mixture thereof.
Claim 7
Dependent Claim
25 words
A laminate film according to any one of the preceding claims wherein the thickness of each adhesive layer is from 1 to 3 microns. ,
Claim 8
Dependent Claim
85 words
A process for preparing a laminate film as claimed in any one of the preceding claims, which process comprises extruding a layer consisting of copolymer (I) and two layers consisting of from 20 to 70% by weight of copolymer (II) and 80 to 30% by weight of copolymer (III), and laminating said layers together with adhesive such that said layer of copolymer (I) is the center layer of the resulting laminate film and said two layers of copolymers (II) and (III) are the outermost layers.
Claim 9
Dependent Claim
33 words
A process according to claim 7, wherein said layer of copolymer (I) and said two layers of copolymers (II) and (III) are coextruded by a circular die to form a cylindrical laminate film.
Claim 10
Dependent Claim
32 words
A process according to claim 7, wherein said layer of copolymer (I) and said two layers of copolymer (II) and (III) are coextruded from a T-die to obtain a flat laminate film.
Claim 11
Dependent Claim
26 words
A process for packaging a foodstuff, which process comprises heat-shrink wrapping a foodstuff in a laminate film as claimed in any one of the preceding claims.
References Cited (Backward Citations)
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CA982923A
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US4161562A
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US4226822A
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CA1081598A
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EP0003635A1
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