Patent FR864365A successfully refreshed from Google Patents.
US3959526A
Expired / Lapsed
US
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Process for preparing high barrier, heat-sealable packaging film
Assignee: EIDP Inc
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Filing: 1974-12-20
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Granted: 1976-05-25
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Expires: 1994-12-20
Abstract
Abstract An improvement in a process for preparing a high barrier, heat-sealable packaging material. A flexible base sheet carrying at least a one side copolymer high barrier coating applied from a solvent solution receives a second copolymer coating having optimum heat sealing properties from a dilute solvent coating system thereby yielding, when finally dried, a double copolymer distribution on the base sheet surface having a low level of total retained solvents, particularly high boiling point solvents.
Inventors
- 👤 Isadore Swerlick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:56
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/04; C08J7/042; C08J7/043; C08J7/048; C08J7/052; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/06; C08J2427/00; C08J2427/02; C08J2427/04; C08J2427/08; C08J2433/00; C08J2433/04; C08J2433/06; C08J2433/10; C08J2433/12; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31928
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
104 words
In a process for coating a flexible packaging film with a sub-coating of a high barrier vinylidene chloride copolymer and a top coating of a heat sealable vinylidene chloride copolymer, said coatings being dried after applications, the improvement which consists in applying both coatings from a solvent solution of said copolymers, said top coating applied from a solution containing about 5 to 10% solids to a solids coating weight of about 0.5 to 3 grams/square meter, and drying said coated film to a level of retained solvents in both coating layers of less than about 500 ppm for each constituent of said solvent solution.
Claim 2
Dependent Claim
104 words
In a process for coating a flexible packaging film with a sub-coating of a high barrier vinylidene chloride copolymer and a top coating of a heat sealable vinylidene chloride copolymer, said coatings being dried after applications, the improvement which consists in applying both coatings from a solvent solution of said copolymers, said top coating applied from a solution containing about 5 to 10% solids to a solids coating weight of about 0.5 to 3 grams/square meter, and drying said coated film to a level of retained solvents in both coating layers of less than about 500 ppm for each constituent of said solvent solution.
Claim 3
Dependent Claim
25 words
The improved process as defined in claim 1 wherein said sub-coating and said top coating are applied to both sides of said flexible packaging film.
Claim 4
Dependent Claim
25 words
The process as defined in claim 2 wherein said top coating is applied to a solids coating weight of about 1 to 2 grams/square meter.
Claim 5
Dependent Claim
27 words
The process as defined in claim 3 wherein said copolymer high barrier coating is vinylidene chloride copolymer containing about 89 to 95% by weight of vinylidene chloride.
Claim 6
Dependent Claim
22 words
The process as defined in claim 4 wherein said vinylidene chloride copolymer high barrier coating further contains units of methacrylonitrile/methyl methacrylate/itaconic acid.
Claim 7
Dependent Claim
24 words
The process as defined in claim 3 wherein said top, heat sealable coating of vinylidene chloride copolymer further contains units of acrylonitrile/methyl methacrylate/itaconic acid.
Claim 8
Dependent Claim
14 words
The process as defined in claim 6 wherein said packaging film is regenerated cellulose.
Claim 9
Dependent Claim
14 words
The process as defined in claim 7 wherein said packaging film is polyethylene terephthalate.
Claim 10
Dependent Claim
29 words
The process as defined in claim 6 wherein said organic solvent solution for said top coating is a tetrahydrofuran/toluene solution containing from about 60 to 80 weight percent tetrahydrofuran.
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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) | 1979-05-25 | 1979-11-24 | 1980-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-25 | 1983-11-24 | 1984-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-25 | 1987-11-24 | 1988-05-25 | $7700.00 | Window Closed / Lapsed |