Method of making a colored reflective article that has a dye covalently bonded to a polymer

Abstract

Exposed lens retroreflective article 10 that comprises a colored layer 14 and a layer of optical elements 12 that are partially embedded in the colored layer 14. The colored layer 14 comprises reflective flakes 16 and a dye that is covalently bonded to a polymer 18. The articles can retain their color after multiple industrial wash cycles. The use of a reactive dye, reflective flakes, and/or polymer precursor during the preparation of the colored layer enables a launderably-durable colored retroreflective article to be made without the use of a solvent and without the use of a temporary carrier.

What is claimed:  
     
         1 . An exposed lens retroreflective article that comprises: 
 a colored layer that comprises reflective flakes disposed in a polymeric material, the polymeric material comprising a dye that is covalently bonded to a polymer; and    a layer of optical elements that are partially embedded in the colored layer.    
     
     
         2 . The exposed lens retroreflective article of  claim 1 , wherein the optical elements are light transmissive microspheres.  
     
     
         3 . The exposed lens retroreflective article of  claim 2 , wherein the colored layer comprises 10 to 50 weight % reflective flakes based on the weight of the colored layer.  
     
     
         4 . The exposed lens retroreflective article of  claim 3 , wherein the colored layer further comprises a coupling agent that improves adhesion of the colored layer to the microspheres.  
     
     
         5 . The exposed lens retroreflective article of  claim 4 , wherein the colored layer consists essentially of polymer, dye, reflective flakes, and coupling agent.  
     
     
         6 . The exposed lens retroreflective article of  claim 3 , wherein the polymer comprises a polyurethane or a polyacrylate.  
     
     
         7 . The exposed lens retroreflective article of  claim 1 , wherein the colored layer comprises a polymer made from a monomeric unit selected from the group consisting of urethane, ester, ether, urea, epoxy, carbonate, acrylate, acrylic, olefin, vinyl chloride, amide, alxyd, and combinations thereof.  
     
     
         8 . The exposed lens retroreflective article of  claim 7 , wherein the colored layer has an average thickness of about 50 to 300 micrometers.  
     
     
         9 . The exposed lens retroreflective article of  claim 1 , wherein neither the x or y color coordinates on the standard CIE 1931 chromaticity diagram change by no more than 0.02 after 20 cycles of the Industrial Laundering Procedure 1.  
     
     
         10 . The exposed lens retroreflective article of  claim 1 , wherein neither the x or y color coordinates on the standard CIE 1931 chromaticity diagram change by more no than 0.02 after 20 cycles of the Industrial Laundering Procedure 2.  
     
     
         11 . The exposed lens retroreflective article of  claim 2 , wherein E* changes by 4 or less after 20 wash cycles of the Industrial Laundering Procedure 1.  
     
     
         12 . The exposed lens retroreflective article of  claim 2 , wherein E* changes by 4 or less after 20 wash cycles of the Industrial Laundering Procedure 2.  
     
     
         13 . The exposed lens retroreflective article of  claim 1 , wherein the colored layer comprises ester urethane units and a hydroxyl-functionalized reactive dye.  
     
     
         14 . An article of clothing that has the exposed lens retroreflective article of  claim 1  secured to an outer surface thereof.  
     
     
         15 . The article of clothing of  claim 14  being a firefighter's jacket or a safety vest.  
     
     
         16 . A transfer article that comprises the article of  claim 2 , and a carrier web into which the layer of microspheres is also partially embedded.  
     
     
         17 . A method of making a colored retroreflective article, which method comprises: 
 contacting a precursor color coating with optical elements, wherein the precursor color coating comprises a reactive dye, reflective flakes, and a polymer precursor; and    curing the precursor color coating to form a colored layer that contains the reflective flakes, that has the dye covalently bonded to a polymer, and that has the optical elements supported by the colored layer.    
     
     
         18 . The method of  claim 17 , wherein the precursor color coating does not contain solvent.  
     
     
         19 . The method of  claim 18 , wherein the precursor color coating comprises 0.5 to 20 weight percent of a reactive dye and 20 to 40 weight percent of reflective flakes.  
     
     
         20 . The method of  claim 18 , wherein the precursor color coating comprises a polyether polyol, an organic polyisocyanate, and a poly-hydroxyl-functionalized dye.  
     
     
         21 . The method of  claim 20 , wherein the precursor color coating further comprises a silane coupling agent.  
     
     
         22 . The method of  claim 18 , wherein the precursor color coating comprises an acrylate monomer, a polyol, and an isocyanate.  
     
     
         23 . The method of  claim 18 , wherein the precursor color coating is applied to release paper, and then the optical elements are applied over the precursor color coating, wherein the optical elements are not disposed in a carrier layer.  
     
     
         24 . A solventless method of making a retroreflective article, which method comprises: 
 applying a solventless precursor color coating layer on the surface of a substrate, wherein the precursor color coating layer comprises a dye, reflective flakes, and a polymer precursor;    applying optical elements onto the precursor color coating layer, wherein the optical elements are not disposed in a carrier layer; and    curing the precursor color coating to form a colored layer.    
     
     
         25 . The method of  claim 24 , wherein the optical elements are light transmissive microspheres.  
     
     
         26 . The method of  claim 24 , wherein the dye is a reactive dye.  
     
     
         27 . The method of  claim 24 , wherein the microspheres are spread out over the surface of the precursor color coating.  
     
     
         28 . The method of  claim 24 , wherein the polymer precursor comprises an actylate monomer, a polyol, and an isocyanate.