Moisture and temperature resistant polarizing lamination
US4292370A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 6, 1979 |
| Grant date | Sep 29, 1981 |
| Priority date | — |
| Expiry date | Dec 6, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31928
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A new moisture resistant polarizing lamination is disclosed which utilizes polypropylene as the protective layers. A polarizing film of polyvinyl alcohol which has been stretched and treated with iodine is protected against moisture and structurally supported by at least one layer of polypropylene. The polypropylene is bonded to the polyvinyl alcohol by adhesives which do not interfere with the polarizing effects of the lamination. The polypropylene may have a bonding layer already attached thereto which is covered by a protective film. The protective film is prevented from becoming secured to the bonding layer by a release agent placed between the protective film and bonding layer. The protective film is removed just prior to bonding of the polypropylene to the polyvinyl alcohol. Use of polypropylene films that are 0.002 inch thick is disclosed. Polypropylene films of this thickness do not adversely affect the polarizing qualities of the lamination. The PVA polarizing film in a sandwich of polypropylene may be provided with one exterior adhesive layer for ease in securing the lamination in its desired final location.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.