The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 08, 1991
Filed:
Feb. 08, 1990
Alcan International Limited, Montreal, CA;
Abstract
A process for coating a polymer sheet with a transparent coating having moisture and oxygen barrier properties. The process starts with a metal substrate made of, or having a surface coating of, a valve metal or valve metal alloy. The metal substrate is anodized to form an anodic film of the valve metal on the metal substrate. The anodic film is made readily detachable from the metal by carrying out the anodization step in the presence of an adhesion-reducing agent, e.g. a fluoride. The polymer sheet, usually in the form of a thin transparent layer, is then attached to the anodic film and the anodic film is detached from the metal. The transferred anodic film forms a thin dense oxide coating on the polymer sheet that acts as a barrier against oxygen and moisture transport. The invention can be used for making packaging sheets suitable for packaging foodstuffs, and the like.