RETROFLECTIVE SHEET USING REACTIVE POLYURETHANE ADHEREND

摘要

A retroreflective sheeting utilizing a particular polymer as the bead bond layer is disclosed. The polymeric bead bond comprises urethane and urea linkages, and has a stage prior to thermosetting in which it may be softened by the application of heat and in which it has a relatively nontacky character. Preferably the polymeric bead bond composition is prepared from an isocyanate-functional polymeric compound which has a substantial portion of its isocyanate groups masked with an isocyanate masking agent, and a crosslinking agent which is substantially insoluble in aprotic solvents. The retroreflective sheeting disclosed possesses the unique combination of high reflectance and superior exterior durability.