Angular brightness microprismatic retroreflective film or sheeting incorporating a syndiotactic vinyl aromatic polymer
US6274221A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1999 |
| Grant date | Aug 14, 2001 |
| Priority date | — |
| Expiry date | Jan 29, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24479
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A novel microprismatic retroreflective film or sheeting is provided which comprises a transparent semicrystalline polymer. The microprismatic retroreflective film or sheeting of the present invention offers superior retroreflective brightness at large angles of incidence and at large observational angles. Syndiotactic vinyl aromatic polymers, especially syndiotactic polystyrene and copolymers thereof, are preferred semicrystalline polymers, as they impart good dimensional stability and resistance to moisture, and can be made resistant to UV radiation. Signing materials comprising these microprismatic retroreflective films provide improved performance for off-angle illumination and viewing in traffic control and other signing applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.