Diffusive light reflectors with polymeric coating

Abstract

A diffuse light reflector is disclosed for use in lighting fixtures including luminaires, light boxes, displays, signage, daylighting applications, and the like. The reflector includes a light reflective nonwoven and a polymer layer that enhances reflectivity. The reflector can be laminated to coil steel or aluminum and can be formed in metal coil or sheet forming operations. The polymer layer can be easily cleaned of machine oils from the metal forming operations.

1 . A diffuse light reflector comprising a plexifilamentary film-fibril sheet substrate having a first side and a second side, wherein said first side is adapted to be adjacent to a light source; and a polymer layer on said first side of said film-fibril sheet, wherein said polymer layer is selected from the group consisting of polyolefin, polyester, polyacrylate, and blends thereof. 
     
     
         2 . The reflector of  claim 1  having a gloss of less than 10%. 
     
     
         3 . The reflector of  claim 2  having a gloss of about 5%. 
     
     
         4 . The reflector of  claim 1  having a reflectance from about 94% to about 97% measured at 550 nm. 
     
     
         5 . The reflector of  claim 1 , having an average surface roughness from about 6.4 microns to about 2.8 microns, measured at 5× magnification. 
     
     
         6 . The reflector of  claim 5 , wherein the average, surface roughness is about 3.5 microns, measured at 5× magnification. 
     
     
         7 . The reflector of  claim 1 , having a roughness uniformity less than about 1.0 microns, measured at 5× magnification. 
     
     
         8 . The reflector of  claim 7 , wherein the roughness uniformity is about 0.4 microns, measured at 5× magnification. 
     
     
         9 . The reflector of  claim 1 , wherein said polymer layer comprises high density polyethylene or low density polyethylene. 
     
     
         10 . The reflector of  claim 1  having a thickness between about 150 microns and about 1000 microns. 
     
     
         11 . The reflector of  claim 1 , wherein said polymer layer is extruded on said first side of said film fibril sheet. 
     
     
         12 . The reflector of  claim 1 , wherein said polymer layer comprises a polyethylene methacrylate copolymer blend. 
     
     
         13 . The reflector of  claim 1 , wherein said polymer layer comprises a blend of high density polyethylene and low density polyethylene. 
     
     
         14 . The reflector of one of  claims 1 , wherein said polymer layer comprises at least one component selected from the group consisting of titanium dioxide and barium sulfate at an amount greater than about 3 to about 20 weight percent of said polymer layer. 
     
     
         15 . The reflector of one of  claims 1 , further comprising an additional polymer layer adjacent to said polymer layer. 
     
     
         16 . The reflector of  claim 15 , wherein said additional polymer layer comprises ethylene methyl acrylate copolymer. 
     
     
         17 . The reflector of one of  claims 1 , further comprising an additional plexifilamentary film-fibril sheet substrate. 
     
     
         18 . A laminate comprising the reflector of  claim 1  affixed to a steel or aluminum sheet. 
     
     
         19 . The laminate of  claim 18 , wherein said reflector is affixed to said steel or aluminum sheet with a hot melt adhesive comprising a component selected from the group consisting of polyethylene and methacrylate. 
     
     
         20 . The laminate of  claim 19 , wherein said hot melt adhesive comprises low density polyethylene. 
     
     
         21 . The laminate of  claim 20 , wherein said hot melt adhesive is an epoxy comprising acrylic. 
     
     
         22 . A lighting fixture comprising a laminate comprising the reflector of  claim 1  affixed to a steel or aluminum sheet, wherein said lighting fixture is selected from the group consisting of luminaires, lighted signs, and daylighting reflectors. 
     
     
         23 . A diffuse light reflector comprising a plexifilamentary film-fibril sheet substrate having a first side and a second side, wherein the first side is adapted to be adjacent to a light source, and a polymer layer on said first side of said film-fibril sheet, and an opaque blackout layer on said second side of said film-fibril sheet, wherein the polymer layer is a polyolefin, polyester, polyacrylate or blends thereof. 
     
     
         24 . The diffusive light reflector of  claim 23 , wherein said opaque blackout layer comprises carbon black. 
     
     
         25 . A method of providing diffuse light to plants comprising: (a) providing a plexifilamentary film-fibril sheet substrate having a first side and a second side, wherein the first side is adapted to be adjacent to a light source, and a polymer layer on said first side of said film-fibril sheet, and an opaque blackout layer on said second side of said film-fibril sheet, wherein the polymer layer is a polyolefin, polyester, polyacrylate or blends thereof; and (b) directing diffuse light from said plexifilmentary film-fibril sheet onto said plants.