ENCLOSED-LENS PETROREFLECTIVE SHEETING HAVING TOUGH,WEATHER-RESISTANT,TRANSPARENT COVER FILM

摘要

A transparent cover film better protects enclosed-lens retroreflective sheeting and can be applied more economically when it is extruded and is a thermoplastic polymer which has good elongation and minimal elastic memory. Preferred polymers are (a) aliphatic urethanes and (b) copolymers of ethylene or propylene.