US3925591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transparent laminate films of polyolefines and polyesters and processes for their manufacture
Assignee: DuPont de Nemours Deutschland GmbH
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Filing: 1975-01-29
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Granted: 1975-12-09
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Expires: 1995-01-29
Abstract
Abstract Laminate films of polyesters which are difficult to crystallise and of polyethylene, bonded with an ethylene/vinyl acetate copolymer as an adhesion promoter, can be deep-drawn and do not lose their transparency during the stretching process. The laminates are particularly suitable for transparent packaging.
Inventors
- 👤 Franz Breitenfellner
- 👤 Wolfgang Eberle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:39
CPC Classifications
B; B32; B32B; B32B27/00; C; C08; C08J; C08J5/00; C08J5/12; C08J5/124; C08J5/128; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/269; Y10T428/31504; Y10T428/31786; Y10T428/31797; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
58 words
DEEP-DRAWABLE, TRANSPARENT LAMINATE FILMS OF POLYETHYLENE FILMS, POLYESTER FILMS AND AN ADHESION PROMOTER, CHARACTERISED IN THAT AT LEAST ONE UNSTRETCHED POLYESTER FILM CONSISTING OF OR BASED ON POLYETHYLENE TEREPHTHALATE, HAVING A CRYSTALLISATION TEMPERATURE OF AT LEAST 150*C, MEASURED IN THE FILM, IS BONDED VIA AN ADHESION-PROMOTING LAYER OF ETHYLENE/VINYL ACETATE COPOLYMER TO AT LEAST ONE UNSTRETCHED POLYETHYLENE FILM.
Claim 2
Dependent Claim
58 words
DEEP-DRAWABLE, TRANSPARENT LAMINATE FILMS OF POLYETHYLENE FILMS, POLYESTER FILMS AND AN ADHESION PROMOTER, CHARACTERISED IN THAT AT LEAST ONE UNSTRETCHED POLYESTER FILM CONSISTING OF OR BASED ON POLYETHYLENE TEREPHTHALATE, HAVING A CRYSTALLISATION TEMPERATURE OF AT LEAST 150*C, MEASURED IN THE FILM, IS BONDED VIA AN ADHESION-PROMOTING LAYER OF ETHYLENE/VINYL ACETATE COPOLYMER TO AT LEAST ONE UNSTRETCHED POLYETHYLENE FILM.
Claim 3
Dependent Claim
17 words
Laminate films according to claim 1, characterised in that the polyethylene film consists of low density polyethylene.
Claim 4
Dependent Claim
20 words
Laminate films according to claim 1, characterised in that the polyester film has a crystallisation temperatuRe of at least 160*C.
Claim 5
Dependent Claim
56 words
Laminate films according to claim 1, characterised in that the polyester film consists of a polyethylene terephthalate which contains at least 25 mol %, preferably at least 40 mol %, of condensed terephthalic acid radicals and at least 25 mol %, preferably at least 40 mol %, of condensed ethylene glycol radicals, relative to the polyester.
Claim 6
Dependent Claim
22 words
Laminate films according to claim 4, characterised in that the polyethylene terephthalate contains 1 to 10 mol % of isophthalic acid radicals.
Claim 7
Dependent Claim
27 words
Laminate films according to claim 4, characterised in that the polyethylene terephthalate contains 1 to 10 mol %, especially 2.5 to 7.5 mol %, of 2,2''-dimethyl-bis-(4''-hydroxyethoxyphenyl)propane radicals.
Claim 8
Dependent Claim
27 words
Laminate films according to claim 4, characterised in that the polyethylene terephthalate contains 1 to 7.5 mol %, in particular 2.5 to 5 mol %, of 1,6-trimethylhexanediol.
Claim 9
Dependent Claim
25 words
Laminate films according to claim 1, characterised in that the ethylene/vinyl acetate copolymer has a melting point of 40* to 95*C, preferably 45* to 75*C.
Claim 10
Dependent Claim
121 words
Process for the manufacture of deep-drawable transparent laminate films of unstretched polyethylene films, unstretched polyester films having a crystallisation temperature of at least 150*C, measured in the film, and an adhesion promoter, characterised in that a) at least one polyethylene moulding material, b) at least one polyester moulding material consisting of, or based on, polyethylene terephthalate having a crystallisation temperature above 150*C and c) a moulding material of an ethylene/vinyl acetate copolymer as the adhesion promoter, are converted into the form of layers by co-extrusion by means of a multi-layer die or by means of several individual dies and the layers are bonded to one another, whilst still in the molten state, in the die or shortly after leaving the die.
Claim 11
Dependent Claim
121 words
Process for the manufacture of deep-drawable transparent laminate films of unstretched polyethylene films, unstretched polyester films having a crystallisation temperature of at least 150*C, measured in the film, and an adhesion promoter, characterised in that a) at least one polyethylene moulding material, b) at least one polyester moulding material consisting of, or based on, polyethylene terephthalate having a crystallisation temperature above 150*C and c) a moulding material of an ethylene/vinyl acetate copolymer as the adhesion promoter, are converted into the form of layers by co-extrusion by means of a multi-layer die or by means of several individual dies and the layers are bonded to one another, whilst still in the molten state, in the die or shortly after leaving the die.
Claim 12
Dependent Claim
19 words
Process according to claim 9, characterised in that the crystallisation temperature is at least 160*C, preferably at least 170*C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |