US4695491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat-shrinkable composite packaging film
Assignee: Okura Industrial Co Ltd
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Filing: 1985-05-31
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Granted: 1987-09-22
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Expires: 2005-05-31
Abstract
Abstract A heat-shrinkable, composite packaging film comprising (a) a core layer of saponified ethylene-vinyl acetate copolymer; (b) a first polymeric outer wall bonded to one side of the core layer; and (c) a second, heat-sealable polymeric outer wall bonded to the other side of the core layer; said first and second outer walls each having a permeability to hot water having a temperature of 90° C. of less than 600 g/m 2 /hour. The film is suitable for packaging meat and other food products subjected to sterilization and heat-shrinking process in a hot water bath.
Inventors
- 👤 Kazuo Kondo
- 👤 Nobuya Ishiguro
- 👤 Teruo Tada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:52
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; B29; B29C; B29C61/00; B29C61/06; B29C61/0608; B29C61/0616; B32B27/06; B32B27/08; B32B27/30; B32B27/306; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/70; B32B2307/732; B32B2307/734; B32B2307/736; B32B2439/00; B32B2439/70; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31725; Y10T428/31739; Y10T428/31743; Y10T428/31746; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192; Y10T428/31928
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
227 words
A heat-shrinkable, composite packaging film comprising: (a) a core layer of saponified ethylene-vinyl acetate copolymer of 3-20 microns thickness; (b) a first polymeric outer wall, comprising a first inner layer of a modified polyolefin based resin, directly bonded to said one side of the core layer, and a first outermost layer of a polyamide resin bonded to said inner layer on the side thereof opposite to the core layer, said inner layer and said outermost layer each having a thickness of 5-25 microns; and (c) a second, heat-sealable polymeric outer wall, bonded to the other side of the core layer, comprising either (i) a single layer of a heat-sealable modified polyolefin based resin or (ii) a laminate comprising a second inner layer of a modified polyolefin based resin bonded to said other side of the core layer and a second outermost layer of a heat-sealable polyolefin based resin, the thickness of said second outer wall being 5-50 microns; said first and second outer wall each having a permeability to hot water having a temperature of 90° C. of less than 600 g/m 2 /hour; said composite film having a total thickness of about 20-120 microns and exhibiting excellent resistance to whitening and delamination when a package sealed in an envelope of the composite film with said first outermost layer being exposed outwardly is sterilized in hot water.
Claim 2
Dependent Claim
227 words
A heat-shrinkable, composite packaging film comprising: (a) a core layer of saponified ethylene-vinyl acetate copolymer of 3-20 microns thickness; (b) a first polymeric outer wall, comprising a first inner layer of a modified polyolefin based resin, directly bonded to said one side of the core layer, and a first outermost layer of a polyamide resin bonded to said inner layer on the side thereof opposite to the core layer, said inner layer and said outermost layer each having a thickness of 5-25 microns; and (c) a second, heat-sealable polymeric outer wall, bonded to the other side of the core layer, comprising either (i) a single layer of a heat-sealable modified polyolefin based resin or (ii) a laminate comprising a second inner layer of a modified polyolefin based resin bonded to said other side of the core layer and a second outermost layer of a heat-sealable polyolefin based resin, the thickness of said second outer wall being 5-50 microns; said first and second outer wall each having a permeability to hot water having a temperature of 90° C. of less than 600 g/m 2 /hour; said composite film having a total thickness of about 20-120 microns and exhibiting excellent resistance to whitening and delamination when a package sealed in an envelope of the composite film with said first outermost layer being exposed outwardly is sterilized in hot water.
Claim 3
Dependent Claim
29 words
The composite packaging film of claim 1, wherein the saponified ethylene-vinyl acetate copolymer has an ethylene content of 25-45 mole percent and a saponification degree of at least 96%.
Claim 4
Dependent Claim
20 words
The composite packaging film of claim 1, wherein said polyamide resin is a copolymer of nylon 6 and nylon 66.
Claim 5
Dependent Claim
32 words
The composite packaging film of claim 1, wherein the modified polyolefin based resin of said first inner layer is a modified polyethylene, modified polypropylene, modified ethylene-vinyl acetate copolymer or a blend thereof.
Claim 6
Dependent Claim
36 words
The composite packaging film of claim 1, wherein said single layer of heat-sealable modified polyolefin based resin of said second outer wall is a modified polyethylene, modified polypropylene, modified ethylene-vinyl acetate copolymer or a blend thereof.
Claim 7
Dependent Claim
28 words
The composite packaging film of claim 1, wherein said heat-sealable polyolefin based resin of said second outer wall is polyethylene, polypropylene, ethylene-vinyl acetate copolymer or a blend thereof.
Claim 8
Dependent Claim
32 words
The composite packaging film of claim 1, wherein said modified polyolefin based resin of said second inner layer is a modified polyethylene, modified polypropylene, modified ethylene-vinyl acetate copolymer or a blend thereof.
Claim 9
Dependent Claim
11 words
The composite packaging film of claim 1, as a tubular extrudate.
Claim 10
Dependent Claim
51 words
The composite packaging film of claim 8, as a biaxially stretched tubular extrudate of a tubular film of polyamide bonded to a tubular film of modified polyethylene, which is bonded to a tubular film of a saponified ethylene-vinyl acetate copolymer, which is bonded to a tubular film of a modified polyethylene.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-21 | 1991-03-23 | 1991-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-21 | 1995-03-23 | 1995-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-21 | 1999-03-23 | 1999-09-22 | $7700.00 | Window Closed / Lapsed |