EP0202814A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Multiple layer polymeric films, process for making them and packages made from them
Assignee: Rexam Beverage Can Co
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Filing: 1986-05-07
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Granted: —
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Expires: 2006-05-07
Abstract
Abstract A packaging film (10) is characterized by the inclusion of a layer (14) of a vinylidene chloride copolymer, e.g. VDC-methylacrylate copolymer, between at least two other layers (16, 18) which contain ethylene vinyl acetate, and optionally linear low density polyethylene. The film may be unoriented or molecularly oriented, may be heat set, and if oriented, optionally the film may be cross-linked. A process of making the cross-linked film includes the steps of joining the layers in face-to-face contact e.g. by coextrusion and of crosslinking the film after assembly of the vinylidene chloride copolymer layer into the structure. Cross-linking can be achieved by electron beam irradiation at a level of at least 1.5 megarads. The film can have a further layer or layers e.g. for heat sealing and for improving its abuse resistance, and can be made into a heat shrinkable bag suitable for packaging foodstuffs.
Inventors
- 👤 Samuel W. Tse
- 👤 Almar T. Widiger
- 👤 Keith D. Lind
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 12:29
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B29; B29C; B29C55/00; B29C55/02; B29C55/023; B29C48/00; B29C48/001; B29C61/00; B29C61/06; B29C61/0608; B29C61/0616; B29C71/00; B29C71/04; B32B27/30; B32B27/304; B32B27/306; B32B37/00; B32B37/14; B32B37/15; B32B37/153; B65; B65D; B65D31/00; B65D31/02; B29C35/00; B29C35/02; B29C35/08; B29C35/0866; B29C2035/0877; B29C48/0018; B29C48/0022; B29C48/03; B29C48/07; B29C48/08; B29C48/09; B29C48/10; B29C48/16; B29C48/18; B29C48/21; B29C71/02; B29K; B29K2105/00; B29K2105/24; B29L; B29L2009/00; B32B2305/00; B32B2305/72; B32B2307/00; B32B2307/50; B32B2307/514; B32B2307/70; B32B2307/732; B32B2307/734; B32B2307/736; B32B2310/00; B32B2310/08; B32B2310/0875; B32B2310/0887; B32B2327/00; B32B2327/06; B32B2331/00; B32B2331/04; B32B2439/00; B32B2439/70; B32B2553/00; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/1334; Y10T428/1341; Y10T428/1352; Y10T428/1379; Y10T428/1383; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
40 words
A multiple layer polymeric film including first and second layers (16, 18), the compositions of which comprise major fractions of ethylene vinyl acetate copolymer; and a third layer (14) of vinylidene chloride-methylacrylate copolymer disposed between the first and second layers.
Claim 2
Dependent Claim
40 words
A multiple layer polymeric film including first and second layers (16, 18), the compositions of which comprise major fractions of ethylene vinyl acetate copolymer; and a third layer (14) of vinylidene chloride-methylacrylate copolymer disposed between the first and second layers.
Claim 3
Dependent Claim
41 words
A film according to claim 1, wherein the composition of at least one of the first and second layers is a blend of 10% by weight to 90% by weight linear low density polyethylene and 90% to 10% ethylene vinyl acetate.
Claim 4
Dependent Claim
69 words
A film according to claim 1 wherein the composition of either or both of the first and second layers is 20% to 40% linear low density polyethylene and 80% to 60% ethylene vinyl acetate, the ethylene vinyl acetate having a vinyl acetate content of 6% to 12% and a melt index of 0.2 to 0.8, and the linear low density polyethylene having a melt index of 0.5 to 1.5.
Claim 5
Dependent Claim
21 words
A film according to claim 1, 2 or 3, wherein each of said first, second and third layers are molecularly oriented.
Claim 6
Dependent Claim
79 words
A molecularly oriented multiple layer polymeric film comprising first and second layers (16, 18) the composition of which is made from a major fraction of ethylene vinyl acetate copolymer, and a third layer (14) disposed therebetween the composition of which is made from a vinylidene chloride copolymer, e.g. vinylidene chloride- methylacrylate copolymer, and each of the first, second, and third layers having been cross-linked in an amount equivalent to exposure to at least 1.5 megarads of electron beam irradiation.
Claim 7
Dependent Claim
79 words
A molecularly oriented multiple layer polymeric film comprising first and second layers (16, 18) the composition of which is made from a major fraction of ethylene vinyl acetate copolymer, and a third layer (14) disposed therebetween the composition of which is made from a vinylidene chloride copolymer, e.g. vinylidene chloride- methylacrylate copolymer, and each of the first, second, and third layers having been cross-linked in an amount equivalent to exposure to at least 1.5 megarads of electron beam irradiation.
Claim 8
Dependent Claim
41 words
A film according to claim 5, wherein the composition of at least one of the first and second layers is a blend of 10% by weight to 90% by weight linear low density polyethylene and 90% to 10% ethylene vinyl acetate.
Claim 9
Dependent Claim
73 words
A film according to claim 5, wherein the composition of either or both of the first and second layers is 20% to 40% linear low density polyethylene and 80% to 60% ethylene vinyl acetate, the ethylene vinyl acetate having a vinyl acetate content of 6% to 12% and a melt index, before cross-linking, of 0.2 to 0.8; and the linear low density polyethylene having a melt index, before cross-linking, of 0.5 to 1.5.
Claim 10
Dependent Claim
204 words
An oriented multiple layer polymer film, comprising: (a) first and second layers forming a first pair of layers which have essentially the same composition; (b) a third barrier layer of a vinylidene chloride copolymer, e.g. vinylidene chloride- methylacrylate copolymer, between the first and second layers and in surface-to-surface contact therewith; and (c) fourth and fifth layers forming a second pair of layers which are adhered to the first and second layers on the surfaces thereof opposite the third layer, the fourth and fifth layers having essentially the same composition, in the combined composition of said first and second pairs of layers, the composition of at least one of said pairs comprising at least 50% of an ethylene vinyl acetate component, the remainder of said one pair being a linear low density polyethylene; and the composition of at least one of said pairs comprising at least 10% linear low density polyethylene component, the remainder of said one pair being ethylene vinyl acetate, where the requirement for said components, of at least 50% ethylene vinyl acetate and said 10% linear low density polyethylene, may be met by one of said pairs having both said components or by each of said pairs having one of said components.
Claim 11
Dependent Claim
204 words
An oriented multiple layer polymer film, comprising: (a) first and second layers forming a first pair of layers which have essentially the same composition; (b) a third barrier layer of a vinylidene chloride copolymer, e.g. vinylidene chloride- methylacrylate copolymer, between the first and second layers and in surface-to-surface contact therewith; and (c) fourth and fifth layers forming a second pair of layers which are adhered to the first and second layers on the surfaces thereof opposite the third layer, the fourth and fifth layers having essentially the same composition, in the combined composition of said first and second pairs of layers, the composition of at least one of said pairs comprising at least 50% of an ethylene vinyl acetate component, the remainder of said one pair being a linear low density polyethylene; and the composition of at least one of said pairs comprising at least 10% linear low density polyethylene component, the remainder of said one pair being ethylene vinyl acetate, where the requirement for said components, of at least 50% ethylene vinyl acetate and said 10% linear low density polyethylene, may be met by one of said pairs having both said components or by each of said pairs having one of said components.
Claim 12
Dependent Claim
36 words
An oriented film according to claim 8, wherein said first pair of layers comprises 70% to 100% of said ethylene vinyl acetate and said second pair of layers comprises 10% to 90% linear low density polyethylene.
Claim 13
Dependent Claim
32 words
An oriented film according to claim 9, wherein said first pair of layers comprises 100% ethylene vinyl acetate and said second pair of layers comprises 50% to 90% linear low density polyethylene.
Claim 14
Dependent Claim
36 words
An oriented film according to claim 8, wherein said first pair of layers comprises 50% to 100% linear low density polyethylene and said second pair of layers comprises 50% to 100% of said ethylene vinyl acetate.
Claim 15
Dependent Claim
34 words
An oriented film according to claim 11, wherein said first pair of layers comprises 90% to 100% linear low density polyethylene and said second pair of layers comprises 90% to 100% ethylene vinyl acetate.
Claim 16
Dependent Claim
34 words
An oriented film according to any of claims 8 to 12, wherein each of said layers has been cross-linked in an amount equivalent to exposure to at least 1.5 megarads of electron beam irradiation.
Claim 17
Dependent Claim
96 words
A process for making a multiple layer, molecularly oriented film, comprising the steps of: (a) forming a multiple layer film having first and second layers the composition of which comprises a major fraction of ethylene vinyl acetate copolymer and a third layer of vinylidene chloride copolymer, e.g. a vinylidene chloride-methylacrylate copolymer, disposed between the first and second layers; (b) heating the multiple layer film to an elevated temperature appropriate for molecular orientation, and molecularly orienting it; and (c) subjecting the said multiple layer film to electron beam irradiation in an amount of at least 1.5 megarads.
Claim 18
Dependent Claim
96 words
A process for making a multiple layer, molecularly oriented film, comprising the steps of: (a) forming a multiple layer film having first and second layers the composition of which comprises a major fraction of ethylene vinyl acetate copolymer and a third layer of vinylidene chloride copolymer, e.g. a vinylidene chloride-methylacrylate copolymer, disposed between the first and second layers; (b) heating the multiple layer film to an elevated temperature appropriate for molecular orientation, and molecularly orienting it; and (c) subjecting the said multiple layer film to electron beam irradiation in an amount of at least 1.5 megarads.
Claim 19
Dependent Claim
41 words
A process according to claim 14, wherein the composition of at least one of the first and second layers is a blend of 10% by weight to 90% by weight linear low density polyethylene and 90% to 10% ethylene vinyl acetate.
Claim 20
Dependent Claim
27 words
A process according to claim 14 or claim 15, including the further step of holding the film at an appropriate elevated temperature and thereby heat setting it.
Claim 21
Dependent Claim
80 words
A process of making a multiple layer film, comprising the steps of: (a) forming a multiple layer film having first and second layers the composition of which comprises a major fraction of ethylene vinyl acetate copolymer and a third layer of vinylidene chloride copolymer, e.g. a vinylidene chloride-methylacrylate copolymer, disposed between said first and second layers; and (b) subjecting the multiple layer film containing the said three layers to electron beam irradiation in an amount of at least 1.5 megarads.
Claim 22
Dependent Claim
80 words
A process of making a multiple layer film, comprising the steps of: (a) forming a multiple layer film having first and second layers the composition of which comprises a major fraction of ethylene vinyl acetate copolymer and a third layer of vinylidene chloride copolymer, e.g. a vinylidene chloride-methylacrylate copolymer, disposed between said first and second layers; and (b) subjecting the multiple layer film containing the said three layers to electron beam irradiation in an amount of at least 1.5 megarads.
Claim 23
Dependent Claim
16 words
A multiple layer film made by the process claimed in any of claims 14 to 17.
Claim 24
Dependent Claim
18 words
A package made from a film produced by the process claimed in any of claims 14 to 18.
Claim 25
Dependent Claim
13 words
A package made from afilm according to any of claims 1 to 13.
Claim 26
Dependent Claim
35 words
A package according to claim 19 or claim 20, which comprises two confronting layers of said film peripherally heat sealed one to the other leaving an opening for insertion of a product into the package.
References Cited (Backward Citations)
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