US4561920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biaxially oriented oxygen and moisture barrier film
Assignee: NORTHERN PETROCHEMICAL COMPANY
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Filing: 1984-02-08
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Granted: 1985-12-31
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Expires: 2004-02-08
Abstract
Abstract A biaxially oriented oxygen and moisture barrier film and a method of producing such a film which comprises co-extruding at least one polyolefin polyolefin layer, at least one layer of an ethylene vinyl alcohol copolymer with a melt flow rate of at least about 8 grams per 10 minutes, and an adhesive layer wherein the layers are combined into a composite sheet with the adhesive interposed between the polyolefin layer and ethylene vinyl alcohol copolymer layers. Next, the composite sheet is immediately cooled so that the crystallinity of the ethylene vinyl alcohol copolymer is no more than about 25 percent. Finally, the composite sheet is biaxially oriented in the longitudinal direction to a degree of about 2:1 to about 4:1 and in the transverse direction to a degree of about 3:1 to about 7:1.
Inventors
- 👤 Ronald H. Foster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:49
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/02; B29C55/023; B29C48/00; B29C48/16; B29C48/18; B29C55/10; B29C55/12; B29C55/14; B29C55/143; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; B32B27/322; B29C48/03; B29C48/07; B29C48/08; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/08; B29K2023/086; B29K2023/10; B29K2023/12; B29K2029/00; B29K2029/04; B29K2995/00; B29K2995/0037; B29K2995/0065; B29K2995/0067; Y; Y10; Y10T; Y10T428/00; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
153 words
A method of producing a biaxially oriented oxygen and moisture barrier film which comprises: (a) co-extruding (1) at least one layer of a polyolefin material selected from the group consisting of polyethylene, polypropylene, and copolymers of ethylene with other olefins, (2) at least one layer of an ethylene vinyl alcohol copolymer with a melt flow rate of at least about 8 grams per 10 minutes, and (3) at least one adhesive layer and combining these layers into a composite sheet wherein the adhesive is interposed between the polyolefin layer and the ethylene vinyl alcohol copolymer layers, (b) immediately cooling the composite sheet so that the crystallinity of the ethylene vinyl alcohol copolymer is no more than about 25 percent, and (c) biaxially orienting the composite sheet in the longitudinal direction to a degree of about 2:1 to about 4:1 and in the transverse direction to a degree of about 3:1 to about 7:1.
Claim 2
Independent Claim
153 words
A method of producing a biaxially oriented oxygen and moisture barrier film which comprises: (a) co-extruding (1) at least one layer of a polyolefin material selected from the group consisting of polyethylene, polypropylene, and copolymers of ethylene with other olefins, (2) at least one layer of an ethylene vinyl alcohol copolymer with a melt flow rate of at least about 8 grams per 10 minutes, and (3) at least one adhesive layer and combining these layers into a composite sheet wherein the adhesive is interposed between the polyolefin layer and the ethylene vinyl alcohol copolymer layers, (b) immediately cooling the composite sheet so that the crystallinity of the ethylene vinyl alcohol copolymer is no more than about 25 percent, and (c) biaxially orienting the composite sheet in the longitudinal direction to a degree of about 2:1 to about 4:1 and in the transverse direction to a degree of about 3:1 to about 7:1.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein the ratio of the thickness of the adhesive to the thickness of the polyolefin layer is about 1:8 to about 1:15.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein the coposite sheet is cooled in a cooling medium at a temperature of 30° to 40° C. in step (b).
Claim 5
Dependent Claim
48 words
The method of claim 1 wherein the longitudinal orientation is carried out at a temperature of from about 130° to about 140° C. and the transverse orientation is carried out at a temperature of from about 150° to 160° C. and the polyolefin layer is comprised of polypropylene.
Claim 6
Dependent Claim
52 words
The method of claim 1 wherein the longitudinal orientation is carried out a temperature of from about 125° to about 130° C. and the transverse orientation is carried out at a temperature of from about 130° to 135° C. and the polyolefin layer is comprised of a copolymer of propylene and ethylene.
Claim 7
Dependent Claim
23 words
The method of claim 1 wherein the polyolefin layer is selected from the group consisting of polypropylene and copolymers of propylene and ethylene.
Claim 8
Dependent Claim
40 words
The method of claim 1 wherein a five layer film is produced comprising two outer polyolefin layers, an inner ethylene vinyl alcohol copolymer layer, and two adhesive layers disposed between the polyolefin layers and the ethylene vinyl alcohol copolymer layer.
Claim 9
Dependent Claim
147 words
A biaxially oriented oxygen and moisture barrier film formed by: (a) co-extruding (1) at least one layer of a polyolefin material selected from the group consisting of polyethylene, polypropylene, and copolymers of ethylene with other olefins, (2) at least one layer of an ethylene vinyl alcohol copolymer with a melt flow rate of at least about 8 grams per 10 minutes, and (3) an adhesive layer and combining these layers into a composite sheet wherein the adhesive is interposed between the polyolefin layer and the ethylene vinyl alcohol copolymer layers, (b) immediately cooling the composite sheet so that the crystallinity of the ethylene vinyl alcohol copolymer is no more than about 25 percent, and (c) biaxially orienting the composite sheet in the longitudinal direction to a degree of about 2:1 to about 4:1 and in the transverse direction to a degree of about 3:1 to about 7:1.
Claim 10
Dependent Claim
147 words
A biaxially oriented oxygen and moisture barrier film formed by: (a) co-extruding (1) at least one layer of a polyolefin material selected from the group consisting of polyethylene, polypropylene, and copolymers of ethylene with other olefins, (2) at least one layer of an ethylene vinyl alcohol copolymer with a melt flow rate of at least about 8 grams per 10 minutes, and (3) an adhesive layer and combining these layers into a composite sheet wherein the adhesive is interposed between the polyolefin layer and the ethylene vinyl alcohol copolymer layers, (b) immediately cooling the composite sheet so that the crystallinity of the ethylene vinyl alcohol copolymer is no more than about 25 percent, and (c) biaxially orienting the composite sheet in the longitudinal direction to a degree of about 2:1 to about 4:1 and in the transverse direction to a degree of about 3:1 to about 7:1.
Claim 11
Dependent Claim
27 words
The film of claim 8 wherein the ratio of the thickness of the adhesive to the thickness of the polyolefin layer is about 1:8 to about 1:15.
Claim 12
Dependent Claim
41 words
The film of claim 8 wherein there are five layers which are comprised of two outer polyolefin layers, an inner ethylene vinyl alcohol copolymer layer, and two adhesive layers disposed between the polyolefin layers and the ethylene vinyl alcohol copolymer layer.
Claim 13
Dependent Claim
23 words
The film of claim 8 wherein the polyolefin layer is selected from the group consisting of polypropylene and copolymers of propylene and ethylene.
Claim 14
Dependent Claim
26 words
The film of claim 8 wherein the composite sheet is cooled in a cooling medium at a temperature of 30° to 40° C. in step (b).
Claim 15
Dependent Claim
46 words
The film of claim 8 wherein the longitudinal orientation is carried out at a temperature of from about 130° to about 14° C. and the transverse orientation is carried out at at temperature of from about 150° to 160° C. when polypropylene is the core layer.
Claim 16
Dependent Claim
52 words
The film of claim 8 wherein the longitudinal orientation is carred out at a temperature of from about 125° to about 130° C. and the transverse orientation is carried out at a temperature of from about 130° to about 135° C. when the core layer is a copolymer of propylene and ethylene.
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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) | 1988-12-30 | 1989-07-01 | 1989-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-30 | 1993-07-01 | 1993-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-30 | 1997-07-01 | 1997-12-31 | $7700.00 | Window Closed / Lapsed |