Hologram forming sheet and process for producing the same
US5200253A · kind A · utility
67Cited by
5References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 3, 1990 |
| Grant date | Apr 6, 1993 |
| Priority date | — |
| Expiry date | Aug 3, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31993
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A thin film of molten polypropylene resin extruded from a T die is pressed and cooled with a chill roll equipped with a hologram relief master plate on its peripheral surface, whereupon a hologram pattern is simultaneously formed as an integral part of the polypropylene resin sheet being molded. Since the polypropylene resin has a Rockwell hardness of at least 70, the hologram pattern formed in the resulting hologram forming sheet is less likely to be damaged or lost during subsequent processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.