ROTOCHROMIC ARRAYS AND METHODS OF MAKING AND USING THE SAME

摘要

Sheets comprising co-extruded multi-component arrays that exhibit chromatically variable appearance dependent upon observation angle. The sheet having front and back major surfaces and comprising a first array of a plurality of polymeric ribbons and a plurality of polymeric strands, wherein: (1) each of the polymeric ribbons and polymeric strands is of elongate form; (2) each of the polymeric ribbons has a thickness-to-width aspect ratio, typically of at least three-to-one, and at least one side that is substantially continuously bonded to a polymeric strand, and a thickness greater than the thickness of the polymeric strands; (3) the longitudinal axes of the polymeric ribbons and polymeric strands are substantially parallel; and (4) the polymeric ribbons and polymeric strands have adjacent segments that have a perceptibly different optical appearance. Also, methods and apparatus for making such sheets and methods for using such sheets.