Method for making retroreflective sheeting
US5812316A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1995 |
| Grant date | Sep 22, 1998 |
| Priority date | — |
| Expiry date | Apr 21, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/128
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method for making retroreflective sheeting comprising the steps of placing a light-transmittable protective film on glass beads in a support sheet which consists of a binder layer and a reinforcing layer, and which is provided with retroreflective glass beads embedded in the binder layer, and thermoforming parts of the support sheet under heating and pressure so as to partially bond the binder layer of the support sheet to the protective film, which is characterized in that the reinforcing layer of the support sheet consists of a crosslinkable resin having shearing stress S in the range of 6.times.10.sup.6 -1.2.times.10.sup.7 dyne/cm.sup.2 before the thermoforming. A retroreflective sheeting made by this method has a high uniformity of the joint portions of the support sheet and protective film. Even when this retroreflective sheeting is used outdoors for a long period of time, troubles including peeling-off of the protective film do not substantially occur. This retroreflective sheeting can be utilized extensively as a road sign board, a license plate for a vehicle, a sign board for construction work and an advertisement board.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.