Patent US4501797A successfully refreshed from Google Patents.
US4501797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Unbalanced oriented multiple layer film
Assignee: Rexam Beverage Can Co
•
Filing: 1982-12-01
•
Granted: 1985-02-26
•
Expires: 2002-12-01
Abstract
Abstract An unbalanced polymeric film has a plurality of adjacent molecularly oriented layers. The first, second, and third layers are molecularly oriented, and are, respectively (1) polypropylene, (2) anhydride modified polypropylene and (3) a barrier layer of either ethylene vinyl alcohol or nylon or a blend of ethylene vinyl alcohol and nylon. A fourth layer is optionally oriented and serves as a heat sealable layer having good adhesion to the barrier layer. In a more sophisticated structure, the fourth layer is oriented and serves an adhesive layer between the barrier layer and a fifth sealant layer. The fifth layer is then optionally oriented. A process for making the films comprises heating the exterior surfaces of the two surface layers to a temperature between 10 DEG and 100 DEG F. below the respective heat sealing temperature of each of the respective surface layers, stretching the so-heated film, annealing the stretched film, and cooling the annealed film.
Inventors
- 👤 Scott S. Super
- 👤 Joseph C. Hsu
- 👤 William B. Haffner
- 👤 Jerry F. Jesse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:18
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; B32B27/30; B32B27/306; B32B27/34; B32B37/00; B32B37/14; B32B37/144; B32B7/00; B32B7/04; B32B7/12; B32B2270/00; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/50; B32B2307/514; B32B2307/70; B32B2307/724; B32B2307/7242; B32B2307/7244; B32B2323/00; B32B2323/04; B32B2323/046; B32B2439/00; B32B2439/70; Y; Y10; Y10T; Y10T428/00; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/2848; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928; Y10T428/31935
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
110 words
An unbalanced multiple layer polymeric film having two outer surfaces, and wherein the interfacial adhesion at each layer interface is at least 50 grams per inch width, the layers comprising, in order through the film: (a) a first molecularly oriented layer of polypropylene; (b) a second molecularly oriented adhesive layer of anhydride modified polypropylene; (c) a third molecularly oriented layer of ethylene vinyl alcohol copolymer; and (d) a fourth heat sealable layer; orientation of said film having been accomplished by applying heat to each of said outer surfaces in different amounts, thus creating a temperature differential between said surfaces, and effecting said orientation during the existence of said temperature differential.
Claim 2
Dependent Claim
110 words
An unbalanced multiple layer polymeric film having two outer surfaces, and wherein the interfacial adhesion at each layer interface is at least 50 grams per inch width, the layers comprising, in order through the film: (a) a first molecularly oriented layer of polypropylene; (b) a second molecularly oriented adhesive layer of anhydride modified polypropylene; (c) a third molecularly oriented layer of ethylene vinyl alcohol copolymer; and (d) a fourth heat sealable layer; orientation of said film having been accomplished by applying heat to each of said outer surfaces in different amounts, thus creating a temperature differential between said surfaces, and effecting said orientation during the existence of said temperature differential.
Claim 3
Dependent Claim
31 words
An unbalanced multiple layer film as in claim 1 wherein said fourth layer is molecularly oriented and wherein the composition of said fourth layer comprises carboxy moieties in the polymer structure.
Claim 4
Dependent Claim
23 words
An unbalanced multiple layer film as in claim 1 wherein the composition of said fourth layer comprises carboxy moieties in the polymeric structure.
Claim 5
Dependent Claim
43 words
An unbalanced multiple layer polymeric film as in claim 1 wherein the composition of said fourth layer is chosen from the group consisting of anhydride modified ethylene vinyl acetate, anhydride modified low density polyethylene, anhydride modified medium density polyethylene, and ethylene methylacrylate copolymer.
Claim 6
Dependent Claim
122 words
An unbalanced multiple layer polymeric film having two outer surfaces, and wherein the interfacial adhesion at each layer interface is a least 50 grams per inch width, the layers comprising, in order through the film: (a) a first molecularly oriented layer of polypropylene; (b) a second molecularly oriented adhesive layer of anhydride modified polypropylene; (c) a third molecularly oriented layer of ethylene vinyl alcohol copolymer; (d) a fourth molecularly oriented adhesive layer of anhydride modified polyolefin; and (e) a fifth heat sealable layer; orientation of said film having been accomplished by applying heat to each of said outer surfaces in different amounts, thus creating a temperature differential between said surfaces, and by effecting said orientation during the existence of said temperature differential.
Claim 7
Dependent Claim
122 words
An unbalanced multiple layer polymeric film having two outer surfaces, and wherein the interfacial adhesion at each layer interface is a least 50 grams per inch width, the layers comprising, in order through the film: (a) a first molecularly oriented layer of polypropylene; (b) a second molecularly oriented adhesive layer of anhydride modified polypropylene; (c) a third molecularly oriented layer of ethylene vinyl alcohol copolymer; (d) a fourth molecularly oriented adhesive layer of anhydride modified polyolefin; and (e) a fifth heat sealable layer; orientation of said film having been accomplished by applying heat to each of said outer surfaces in different amounts, thus creating a temperature differential between said surfaces, and by effecting said orientation during the existence of said temperature differential.
Claim 8
Dependent Claim
16 words
An unbalanced multiple layer film as in claim 5 wherein said fifth layer is molecularly oriented.
Claim 9
Dependent Claim
23 words
An unbalanced multiple layer film as in claim 5 wherein the composition of said fifth layer comprises carboxy moieties in the polymeric structure.
Claim 10
Dependent Claim
50 words
An unbalanced multiple layer film as in claim 7 wherein the composition of said fifth layer is chosen from the group consisting of anhydride modified ethylene vinyl acetate, linear low density polyethylene, ionomer, ethylenemethylacrylate, ethylene acrylic acid, and unmodified ethylene vinyl acetate having at least 1.5 mole percent vinyl acetate.
References Cited (Backward Citations)
US4064296A
Cited
US4261473A
Cited
US4194039A
Cited
US4188443A
Cited
US4360550A
Cited
US4407897A
Cited
US4410582A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-26 | 1988-08-27 | 1989-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-26 | 1992-08-27 | 1993-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-26 | 1996-08-27 | 1997-02-26 | $7700.00 | Window Closed / Lapsed |