Inline passivation of vacuum-deposited aluminum on web substrate

Abstract

In a continuous in-vacuum process for the manufacture of a film metallized with aluminum, the aluminum layer is exposed to a passivating agent, inline, immediately after deposition and prior to rewinding of the film onto a take-up roller. Passivation is carried out by plasma treatment in an oxidizing atmosphere (oxygen, nitrogen or others). The resulting product exhibits no peel-off problems during unwinding of the take-up roller and greatly improved corrosion resistance.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a modified vacuum chamber according to the invention, including a plasma treater with a plasma-gas source past the metal-evaporation stage of a conventional process in order to passivate the top side of the metal layer deposited over a web running from a feed roller to a take-up roller in the vacuum chamber.

FIG. 2 is a schematic representation of the same vacuum chamber of FIG. 1 wherein the plasma treater of the invention is placed in a separate, higher-pressure zone of the chamber.

Claims

1. In a process for the manufacture of a metallized film, wherein an aluminum layer is vapor deposited continuously in a vacuum chamber over a web to produce a coated film that is spooled onto a take-up roller, a method of passivation to prevent corrosion and peel-off damage when the roller is unwound for post-production processing, said method comprising the following step: exposing the aluminum layer to a plasma field produced with a plasma gas containing a passivating component, said exposing step being carried out inline in the vacuum chamber prior to spooling said coated web onto the take-up roller.

2. The process of claim 1, wherein said passivating component includes an oxygen-bearing molecule.

3. The process of claim 1, wherein said passivating component includes oxygen.

4. The process of claim 1, wherein said passivating component includes nitrogen.

5. The process of claim 1, further including the step of pre-treating the web in a plasma field prior to depositing said aluminum layer.

6. The process of claim 5, wherein said passivating component includes an oxygen-bearing molecule.

7. The process of claim 5, wherein said passivating component includes oxygen.

8. The process of claim 5, wherein said passivating component includes oxygen.

9. The process of claim 5, wherein said passivating component includes nitrogen.

10. An article of manufacture passivated according to the process of claim 1.

11. An article of manufacture passivated according to the process of claim 2.

12. An article of manufacture passivated according to the process of claim 4.

13. An article of manufacture passivated according to the process of claim 5.

14. An article of manufacture passivated according to the process of claim 6.

15. An article of manufacture passivated according to the process of claim 8.

16. A vapor deposition chamber comprising the following units operating in sequential order over a web being spooled between a feed roller and a take-up roller: a plasma pre-treatment unit for cleaning the web;a metallization unit for coating the web with a metallic layer; anda plasma unit with a source of plasma gas containing a passivating component for passivating the metallic layer after deposition and prior to spooling over said take-up roller.

17. The chamber of claim 16, wherein said passivating component includes an oxygen-bearing molecule.

18. The chamber of claim 16, wherein said passivating component includes oxygen.

19. The chamber of claim 16, wherein said passivating component includes nitrogen.