EP0217252B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Thermoplastic multi-layer packaging film and bags made therefrom
Assignee: WR Grace and Co Conn
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Filing: 1986-09-20
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Granted: 1991-11-13
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Expires: 2006-09-20
Abstract
No abstract record available.
Inventors
- 👤 Richard Stephen Williams
- 👤 Cesare Quacquarella
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 05:08
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/16; B32B27/30; B32B27/304; B32B27/306; B32B27/308; B32B27/32; B32B27/34; B32B7/00; B32B7/04; B32B7/12; C; C09; C09J; C09J123/00; C09J123/02; C09J123/04; C09J123/08; C09J123/0807; C09J123/0815; B32B38/00; B32B2038/0052; B32B2038/0076; B32B2305/00; B32B2305/72; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/70; B32B2307/724; B32B2307/7242; B32B2307/7244; B32B2307/732; B32B2307/734; B32B2307/736; B32B2323/00; B32B2323/04; B32B2327/00; B32B2327/06; B32B2331/00; B32B2331/04; B32B2377/00; B32B2439/00; B32B2439/70; B32B2553/00; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/1334; Y10T428/1341; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31725; Y10T428/3175; Y10T428/31757; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192; Y10T428/31928
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
110 words
A thermoplastic multi-layer packaging film having superior heat shrink and cold seal properties comprising at least an outer polymer layer, an inner heat sealing layer and optionally an oxygen barrier layer between said inner and said outer layer, characterized in that the heat sealing layer comprises a linear copolymer of ethylene and x to y% by weight, based on the copolymer, of an α -olefin with 4 to 8 carbon atoms per molecule, wherein x = 0.5n C + 8 and y = 1.25n C + 15 with n C being the number of carbon atoms in the α -olefin, said copolymer having a density of 0.915 g/cm³ or less.
Claim 2
Dependent Claim
37 words
The film of claim 1, characterized in that the heat sealing layer comprises a copolymer of ethylene and 12 to 20% by weight, based on the copolymer, of an α -olefin with 4 to 8 carbon atoms.
Claim 3
Dependent Claim
39 words
The film of claim 1, characterized in that the heat sealing layer comprises a copolymer of ethylene and 10 to 20% by weight, based on the copolymer, of butene(1), said copolymer having a density of less than 0.915 g/cm³.
Claim 4
Dependent Claim
39 words
The film of claim 1, characterized in that the heat sealing layer comprises a copolymer of ethylene and 12 to 25% by weight, based on the copolymer, of octene(1), said copolymer having a density of 0.915 g/cm³ or less.
Claim 5
Dependent Claim
85 words
The film of anyone of claims 1 to 5, characterized in that the heat sealing layer comprises further up to 50% by weight, based on the layer composition, of a polymer which is compatible with said ethylene/ α -olefin copolymer and is selected from the group comprising linear low density polyethylene (LLDPE), linear high density polyethylene (LHDPE), low density polyethylene (LDPE), ethylene/vinyl acetate (EVA), acid modified EVA, polypropylene, ethylene/propylene copolymers, ionomers and ethylene/alkylacrylate copolymers having 1 to 8 C atoms in the respective alkyl radical.
Claim 6
Dependent Claim
24 words
The film of claim 5, wherein said polymer compatible with said ethylene/ α-olefln copolymer is an ethylene/alkylacrylate copolymer selected from ethylene-methylacrylate, ethylene-ethylacrylate and ethylene-butylacrylate.
Claim 7
Dependent Claim
63 words
The film of anyone of claims 1 to 6, characterized in that the outer polymer layer is of a polymer selected from the group comprising a copolymer of ethylene and 10 to 25% by weight, based on the copolymer, of an α-olefin with 4 to 8 carbon atoms, said copolymer having a density of less than 920 kg/m³, EVA, polyamide, and ionomeric resins.
Claim 8
Dependent Claim
33 words
The film of anyone of claims 1 to 7, characterized in that the oxygen barrier layer comprises a polymer selected from the group comprising polyvinylidene chloride (PVDC) and hydrolized ethylene/vinyl acetate copolymers (EVOH).
Claim 9
Dependent Claim
26 words
The film of anyone of claims 1 to 8, characterized in that an adhesive layer and/or an adhesion promoting layer is interposed between said other layers.
Claim 10
Dependent Claim
23 words
The film of anyone of claims 1 to 9, characterized in that at least the heat sealing layer has been cross-linked by irradiation.
Claim 11
Dependent Claim
23 words
The film of claim 10, characterized in that the oxygen barrier layer comprises EVOH and that the entire multi-layer film has been irradiated.
Claim 12
Dependent Claim
36 words
A side-sealed bag formed from the film of anyone of claims 1 to 11, said film being folded so that the fold forms the bottom of the bag and side-seals close both sides of the bag.
Claim 13
Dependent Claim
47 words
A bag formed from a tubular film of anyone of claims 1 to 11 wherein the bottom of the bag is formed by a transverse seal across the flattened tube and the mouth is formed by severing the tube at a pre-selected distance from said transverse seal.
References Cited (Backward Citations)
US4424243A
Cited
JPS5882752A
Cited
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