Thin film multilayer structure as permeation barrier on plastic film

• US 5,462,779 A
• Filed: 03/02/1993
• Issued: 10/31/1995
• Est. Priority Date: 10/02/1992
• Status: Expired due to Fees

• Current Assignee: Consorzio Ce.Te.V Centro Tecnologie Del Vuoto
• Original Assignee: Consorzio Ce.Te.V Centro Tecnologie Del Vuoto
• Inventors: Staffetti, Francesco, Misiano, Carlo, Simonetti, Enrico
• Primary Examiner(s): Thibodeau, Paul J.
• Assistant Examiner(s): Chen, Vivian
• Application Number:
  US08/025,514
• Time in Patent Office: 973 Days
• Field of Search: 428/35.7, 428/35.8, 428/426, 428/469, 428/448, 428/480, 428/446, 428/472, 428/451, 428/34.4, 428/34.6, 428/34.7, 428/35.4, 428/36.7, 428/36.6, 428/215, 428/216 , 428/337, 428/339, 428/335, 428/702, 428/697, 428/430, 427/255.3, 427/255.5, 427/255.2, 427/526, 427/527, 427/528, 427/574, 427/576, 427/578, 427/579, 427/583, 427/584, 427/588, 427/255.1, 427/419.2, 427/419.3 , 427/595
• US Class Current: 428/34.7
• CPC Class Codes: C04B 35/62222 obtaining ceramic coatings coating of mortars, concrete, artificial or natural stone or ceramics C04B41/45; laminated ceramic products B32B18/00; coating metallic materials C23; coating of glass C03C17/00, applying ceramic coatings on silicon for semi-conductor purposes H01L
• CPC Class Codes: C08J 2367/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds; C08J2367/06 takes precedence
• CPC Class Codes: C08J 2371/12 Polyphenylene oxides
• CPC Class Codes: C08J 7/048 Forming gas barrier coatings
• CPC Class Codes: C08J 7/06 with compositions not containing macromolecular substances
• CPC Class Codes: Y10T 428/1321 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1341 Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/1379 Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/24975 No layer or component greater than 5 mils thick
• CPC Class Codes: Y10T 428/264 Up to 3 mils
• CPC Class Codes: Y10T 428/31616 Next to polyester [e.g., alkyd]
• CPC Class Codes: Y10T 428/31667 Next to addition polymer from unsaturated monomers, or aldehyde or ketone condensation product
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]

Abstract

A barrier coating against oxygen and water vapor penetration for a plastic packaging film comprising two oxides, one of which is SiO₂ while the other is Al₂ O₃. The barrier is a single layer of mixed oxides in which the concentration of Al₂ O₃ increases continuously from 20% by weight to 80% by weight while the concentration of SiO₂ decreases continuously from 80% by weight to 20% by weight as the thickness of the mixed oxide layer increases from the surface of the plastic film. The plastic film is preferably polyethylene terephthalate or polyphenylene oxide and the barrier coating is transparent.

Claims

1. A packaging and wrapping film, comprising a plastic foil, and a transparent barrier coating on said foil reducing permeability thereof to gas and vapor, said coating consisting essentially of SiO₂ and Al₂ O₃ uniformly deposited over a surface of said foil and adherent thereto, said coating being formed in a single layer on said foil containing both SiO₂ and Al₂ O₃, the concentrations of both SiO₂ and Al₂ O₃ varying continuously across the entire thickness of said layer.

2. The packaging and wrapping film defined in claim 1, wherein the concentration of Al₂ O₃ increases from 20% by weight to 80% by weight while the concentration of SiO₂ decreases from 80% by weight to 20% by weight as the thickness of said coating increases from the surface of said foil.

3. The packaging and wrapping film defined in claim 1 wherein said coating is a crucible-applied coating.

4. The packaging and wrapping film defined in claim 1 wherein said coating is an electron beam applied coating.

5. The packaging and wrapping film defined in claim 1 wherein said coating is a sputtering-applied coating.

6. The packaging and wrapping film defined in claim 1 wherein said coating is an ion plating applied coating.

7. The packaging and wrapping film defined in claim 1 wherein said coating is a chemical vapor deposited coating.

8. The packaging and wrapping film defined in claim 1 wherein said foil is a polyethylene terephthalate or polyphenylene oxide foil having a thickness between 10 μ

m and 50 μ

m.