Process and apparatus for producing coated polymer sheets having oxygen and moisture barrier properties and coated polymer sheets thus produced
US5055150A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 8, 1990 |
| Grant date | Oct 8, 1991 |
| Priority date | — |
| Expiry date | Feb 8, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB05D1/00
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.