US5077109A
Expired / Lapsed
US
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Oriented multilayer film and process for making same
Assignee: Curwood Inc
•
Filing: 1990-03-26
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Granted: 1991-12-31
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Expires: 2010-03-26
Abstract
Abstract An oriented multilayer film comprising a barrier layer, a first layer on one side of said barrier layer and a second layer on the opposite side of said barrier layer is provided for use in food packaging applications. The first and second layers have melting points of at least about 115° C. The barrier layer comprises amorphous nylon having a glass transition temperature greater than the higher of the two melting points or higher than the melting point of the first and second layers. The barrier layer is substantially impermeable to oxygen, while the first and second layers may comprise certain polyethylene resins. The oxygen barrier properties of the film do not deteriorate as the barrier layer gradually absorbs moisture. A process for making such multilayer films is also provided.
Inventors
- 👤 Stanley Lustig
- 👤 Stephen J. Vicik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:06
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/34; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/139; Y10T428/1393; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/31504; Y10T428/31725; Y10T428/31739
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
66 words
An oriented multilayer film comprising a core layer, a first layer on one side of core layer and a second layer on the opposite side of said core layer wherein said first layer and said second layer have melting points of at least about 115° C. and said core layer has a glass transition temperature greater than the higher of said first and said second layer.
Claim 2
Dependent Claim
66 words
An oriented multilayer film comprising a core layer, a first layer on one side of core layer and a second layer on the opposite side of said core layer wherein said first layer and said second layer have melting points of at least about 115° C. and said core layer has a glass transition temperature greater than the higher of said first and said second layer.
Claim 3
Dependent Claim
17 words
An oriented multilayer film, as defined in claim 1, wherein said film is a coextruded, tubular film.
Claim 4
Dependent Claim
16 words
An oriented multilayer film, as defined in claim 1, wherein said core layer comprises a polyamide.
Claim 5
Dependent Claim
18 words
An oriented multilayer film as defined in claim 1, wherein said core layer comprises a gas barrier layer.
Claim 6
Dependent Claim
116 words
A process for producing an oriented multilayer film comprising a core layer, a first layer on one side of said core layer and a second layer on the opposite side of said core layer, which process comprises heating a multilayer film with infrared heaters and stretching said multilayer film under conditions sufficient to produce an oriented multilayer film wherein said heating conditions are set to provide an orientation temperature, as measured at the outside of the film, below both melting points of said first and second layers and below the glass transition temperature (Tg) of the core layer wherein said Tg is greater than the higher of said melting points of said first and second layers.
Claim 7
Dependent Claim
116 words
A process for producing an oriented multilayer film comprising a core layer, a first layer on one side of said core layer and a second layer on the opposite side of said core layer, which process comprises heating a multilayer film with infrared heaters and stretching said multilayer film under conditions sufficient to produce an oriented multilayer film wherein said heating conditions are set to provide an orientation temperature, as measured at the outside of the film, below both melting points of said first and second layers and below the glass transition temperature (Tg) of the core layer wherein said Tg is greater than the higher of said melting points of said first and second layers.
Claim 8
Dependent Claim
14 words
A process, as defined in claim 5, wherein multilayer film is a tubular film.
Claim 9
Dependent Claim
15 words
A process, as defined in claim 5, wherein said multilayer film is a coextruded film.
Claim 10
Dependent Claim
16 words
A process, as defined in claim 5, wherein said multilayer film is an extrusion coated film.
Claim 11
Dependent Claim
16 words
A process, as defined in claim 5, wherein said multilayer film is a slot cast film.
Claim 12
Dependent Claim
15 words
A process, as defined in claim 5, wherein said multilayer film is stretched by tentering.
Claim 13
Dependent Claim
32 words
A process, as defined in claim 5, wherein said exit orientation temperature is about 10° C. to 20° C. below the lower of the melting points of said first and second layers.
Claim 14
Dependent Claim
19 words
A process, as defined in claim 5, wherein said orientation temperature is between about 100° C. and 110° C.
Claim 15
Dependent Claim
27 words
A process, as defined in claim 5, wherein at least one of said first and second layers has a melting point of at least about 115° C.
Claim 16
Dependent Claim
14 words
A process, as defined in claim 5, wherein said core layer comprises a polyamide.
Claim 17
Dependent Claim
15 words
A process, as defined in claim 5, wherein said core layer comprises an amorphous nylon.
Claim 18
Dependent Claim
24 words
A process, as defined in claim 5, wherein at least one of said first and second layers is an outermost layer of said film.
Claim 19
Dependent Claim
21 words
A process, as defined in claim 5, wherein both of said first and second layers are outermost layers of said film.
Claim 20
Dependent Claim
23 words
A process, as defined in claim 5, wherein at least one of said first and second layers comprises LLDPE, VLDPE or mixtures thereof.
Claim 21
Dependent Claim
21 words
A process, as defined in claim 5, wherein both of said first and second layers comprise LLDPE, VLDPE or mixtures thereof.
Claim 22
Dependent Claim
50 words
A process, as defined in claim 5, wherein said core layer absorbs infrared heat sufficient to reach a temperature for orientation whereby said heat is transferred to said core layer for absorption by penetration of outer portions of said film including at least one of said first and second layers.
Claim 23
Dependent Claim
70 words
A process, as defined in claim 5, wherein during stretching said core layer is heated to an orientation temperature which is above the glass transition temperature of the core layer by absorbance of infrared heat, which infrared heat first penetrates at least one of said first and second layers at a plurality of wavelengths, whereby said first and second layers are heated to orientation temperatures below these respective melting points.
Claim 24
Dependent Claim
19 words
A process, as defined in claim 5, wherein said core layer and said first and second layers are oriented.
Claim 25
Dependent Claim
31 words
A process, as defined in claim 5, wherein said film further comprises at least one additional layer between said core layer and at least one of said first and second layers.
Claim 26
Dependent Claim
15 words
A process, as defined in claim 5, wherein said core layer comprises nylon 6I, 6T.
Claim 27
Dependent Claim
24 words
A process, as defined in claim 5, wherein said multilayer film is simultaneously stretched in both the machine direction and in the transverse direction.
Claim 28
Dependent Claim
21 words
A process, as defined in claim 5, wherein said film is tubular and said transverse stretching is produced by air pressure.
Claim 29
Dependent Claim
17 words
A process, as defined in claim 5, wherein at least one layer of said film is cross-linked.
Claim 30
Dependent Claim
29 words
A process, as defined in claim 27, wherein said cross-linking is performed by treatment of said film with between about 1 to 10 Mrad of irradiation subsequent to orientation.
Claim 31
Dependent Claim
123 words
A process for producing an oriented multilayer film comprising a polyamide core layer, a first layer on one side of said core layer and a second layer on the opposite side of said core layer, which process comprises heating said multilayer film with infrared heat and stretching said heated film under conditions sufficient to orient said first, second and core layers of said film, wherein said heating conditions provide an orientation temperature, as measured at the outside of the film, below both melting points of said first and second layers and below the glass transition temperature (Tg) of the core layer, wherein said Tg of the core layer is greater than the higher of said melting points of said first and second layers.
Claim 32
Dependent Claim
123 words
A process for producing an oriented multilayer film comprising a polyamide core layer, a first layer on one side of said core layer and a second layer on the opposite side of said core layer, which process comprises heating said multilayer film with infrared heat and stretching said heated film under conditions sufficient to orient said first, second and core layers of said film, wherein said heating conditions provide an orientation temperature, as measured at the outside of the film, below both melting points of said first and second layers and below the glass transition temperature (Tg) of the core layer, wherein said Tg of the core layer is greater than the higher of said melting points of said first and second layers.
Claim 33
Dependent Claim
15 words
A process, as defined in claim 29, wherein said core layer comprises nylon 6I, 6T.
Claim 34
Dependent Claim
18 words
A process, as defined in claim 29, wherein said higher melting point is at least about 115° C.
Claim 35
Dependent Claim
19 words
A process, as defined in claim 29, wherein said orientation temperature is between about 100° C. to 110° C.
Claim 36
Dependent Claim
15 words
A process, as defined in claim 29, wherein said polyamide core layer comprises amorphous nylon.
Claim 37
Dependent Claim
18 words
A process, as defined in claim 33, wherein said higher melting point is at least about 115° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-30 | 2003-07-01 | 2003-12-31 | $7700.00 | Window Closed / Lapsed |