Retroreflective sheet, license plate, and manufacturing method thereof
US10365418B2 · kind B2 · utility
0Cited by
19References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2015 |
| Grant date | Jul 30, 2019 |
| Priority date | — |
| Expiry date | Dec 17, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/124
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The disclosed retroreflective sheet contains a retroreflective layer and a polyurethane surface protecting layer, wherein the surface protecting layer contains at least a reaction product of a polyol with either a polyester backbone or a polycarbonate backbone and a trifunctional or higher aliphatic isocyanate, and the glass transition temperature Tg of the surface protecting layer is 50° C. or higher, and the tan δ of the loss tangent at 120° C. is 0.1 or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.