Patent US4008352A successfully refreshed from Google Patents.
US4008352A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat lamination of thermoplastic films
Assignee: DuPont Canada Inc
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Filing: 1975-01-24
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Granted: 1977-02-15
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Expires: 1995-01-24
Abstract
Abstract A process for the heat lamination of a first film of polyethylene, polyamide, polyester, and such films coated with polyvinylidene chloride, to a second film of polyethylene, ionomer, and such films coated with polyvinylidene chloride. The surface of the first and second films has been treated with a corona discharge prior to heat lamination, and preferably the second film has an adhesion promoter on its surface. The process has the steps of (a) bringing the first and second films into contact, (b) contacting the combined films with a roll heated to a temperature greater than that required to produce low peel strength but less than that at which the laminate adheres to it, (c) passing the laminate through a heated zone to increase the peel strength, and (d) cooling the laminate.
Inventors
- 👤 David Haddon Dawes
- 👤 Kashmiri Lal Gupta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:35
CPC Classifications
B; B29; B29C; B29C43/00; B29C43/22; B29C43/30; B29C43/305; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; B32B27/34; B32B27/36; B32B37/00; B32B37/06; B32B38/00; B32B38/0008; B32B2310/00; B32B2310/14; B32B2323/00; B32B2323/04; B32B2367/00; B32B2377/00; B32B2439/00; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31725; Y10T428/3175; Y10T428/31757; Y10T428/31786; Y10T428/31797; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
194 words
A process for the manufacture of a thermoplastic film laminate wherein at least one surface of a thermoplastic first film selected from the group of polyethylene, polyamide, and polyester is laminated to a surface of a thermoplastic second film of polyethylene, at least the surfaces of said first and second films that are laminated having been treated with a corona discharge, said first and second films having similar melting points and at least one of said films is a film of low-melting polymer, said process comprising the steps of: a. bringing the corona discharge-treated surface of the first film into face-to-face contact with the corona discharge-treated surface of the second film, b. contacting the resulting combination of films with at least one roll heated to a temperature greater than the temperature required to form a laminate having low peel strength but less than the temperature at which the laminate adheres to the heated roll, c. increasing the peel strength of the laminate by passing the laminate through a heated zone, said heated zone being at a temperature at least as high as that of the heated roll, and d. cooling the laminate so formed.
Claim 2
Dependent Claim
194 words
A process for the manufacture of a thermoplastic film laminate wherein at least one surface of a thermoplastic first film selected from the group of polyethylene, polyamide, and polyester is laminated to a surface of a thermoplastic second film of polyethylene, at least the surfaces of said first and second films that are laminated having been treated with a corona discharge, said first and second films having similar melting points and at least one of said films is a film of low-melting polymer, said process comprising the steps of: a. bringing the corona discharge-treated surface of the first film into face-to-face contact with the corona discharge-treated surface of the second film, b. contacting the resulting combination of films with at least one roll heated to a temperature greater than the temperature required to form a laminate having low peel strength but less than the temperature at which the laminate adheres to the heated roll, c. increasing the peel strength of the laminate by passing the laminate through a heated zone, said heated zone being at a temperature at least as high as that of the heated roll, and d. cooling the laminate so formed.
Claim 3
Dependent Claim
18 words
The process of claim 1 in which the laminate is in an unsupported condition in the heated zone.
Claim 4
Dependent Claim
21 words
The process of claim 2 in which there are two heated rolls, one contacting each side of the combination of films.
Claim 5
Dependent Claim
22 words
The process of claim 3 in which the temperature of the heated zone is greater than the temperature of the heated rolls.
Claim 6
Dependent Claim
13 words
The process of claim 4 in which the heated zone is an oven.
Claim 7
Dependent Claim
19 words
The process of claim 5 in which the laminate is cooled by contacting the laminate with a cooled roll.
Claim 8
Dependent Claim
20 words
The process of claim 6 in which the second film contains an adhesion promoter, said adhesion promoter being fumaric acid.
Claim 9
Dependent Claim
13 words
The process of claim 7 wherein the first film is a polyamide film.
Claim 10
Dependent Claim
17 words
The process of claim 7 wherein the first film is a polyamide film coated with polyvinylidene chloride.
Claim 11
Dependent Claim
19 words
The process of claim 3 in which each surface of the first film is laminated to a second film.
Claim 12
Dependent Claim
40 words
The process of claim 10 in which the heated zone is an oven, the laminate is cooled by contacting the laminate with a cooled roll, and the temperature of the oven is greater than the temperature of the heated rolls.
Claim 13
Dependent Claim
20 words
The process of claim 11 in which the second film contains an adhesion promoter, said adhesion promoter being fumaric acid.
Claim 14
Dependent Claim
22 words
The process of claim 12 in which the first film is a polyamide film and the second two films are polyethylene films.
Claim 15
Dependent Claim
215 words
A laminate of peel strength of at least 300 gm/inch, said laminate having been manufactured from thermoplastic films, in which at least one surface of a first film selected from the group consisting of polyethylene, polyamide, and polyester is laminated to a surface of a second film of polyethylene containing an adhesion promoter of fumaric acid, at least the surfaces of said first and second films that are laminated having been treated with a corona discharge, said first and second films having similar melting points and at least one of said films is a film of low-melting polymer, the process of manufacturing said laminate further comprising the steps of: a. bringing the corona discharge-treated surface of the first film into face-to-face contact with the corona discharge-treated surface of the second film and contacting the resulting combination of films with at least one roll heated to a temperature greater than the temperature required to form a laminate having a low peel strength but less than the temperature at which the laminate adheres to the heated roll, b. increasing the peel strength of the laminate by passing the laminate through a heated zone, said heated zone being at a temperature at least as high as that of the heated roll, and c. cooling the laminate so formed.
Claim 16
Dependent Claim
215 words
A laminate of peel strength of at least 300 gm/inch, said laminate having been manufactured from thermoplastic films, in which at least one surface of a first film selected from the group consisting of polyethylene, polyamide, and polyester is laminated to a surface of a second film of polyethylene containing an adhesion promoter of fumaric acid, at least the surfaces of said first and second films that are laminated having been treated with a corona discharge, said first and second films having similar melting points and at least one of said films is a film of low-melting polymer, the process of manufacturing said laminate further comprising the steps of: a. bringing the corona discharge-treated surface of the first film into face-to-face contact with the corona discharge-treated surface of the second film and contacting the resulting combination of films with at least one roll heated to a temperature greater than the temperature required to form a laminate having a low peel strength but less than the temperature at which the laminate adheres to the heated roll, b. increasing the peel strength of the laminate by passing the laminate through a heated zone, said heated zone being at a temperature at least as high as that of the heated roll, and c. cooling the laminate so formed.
Claim 17
Dependent Claim
12 words
The laminate of claim 14 wherein said first film is polyamide film.
Claim 18
Dependent Claim
16 words
The laminate of claim 15 wherein said first film is polyamide film coated with polyvinylidene chloride.
Claim 19
Dependent Claim
19 words
The laminate of claim 15 in which each surface of the polyamide film is laminated to a polyethylene film.
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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) | 1980-02-15 | 1980-08-16 | 1981-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-15 | 1984-08-16 | 1985-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-15 | 1988-08-16 | 1989-02-15 | $7700.00 | Window Closed / Lapsed |