Light-Emitting Diode Assembly Housing Comprising Poly(Cyclohexanedimethanol Terephthalate) Compositions

Abstract

Light-emitting diode assembly housing comprising high temperature poly(1,4-cyclohexanedimethanol terephthalate) compositions containing titanium dioxide.

1 .- 17 . (canceled) 
     
     
         18 . A reflector for a light-emitting diode comprising:
 a housing defining a cavity, the cavity having a shape configured to surround a light-emitting diode, the housing being comprised of a polymer composition comprising about 40 to about 95 weight percent poly(1,4-cyclohexanedimethanol terephthalate); from about 15 percent to about 50 percent by weight of a rutile form of titanium dioxide, the titanium dioxide including a coating, the coating comprising a metal oxide or an organic coating; the polymer composition further including at least one polymeric toughener.   
     
     
         19 . A reflector as defined in  claim 18 , wherein the coating on the titanium dioxide comprises alumina. 
     
     
         20 . A reflector as defined in  claim 18 , wherein the housing has a reflectance at 460 nm of at least 76 percent when measured at a surface temperature of 75° C. and at a distance of 4 centimeters from a light source and wherein the housing has a whiteness index after being aged at 200° C. for two hours of at least 44. 
     
     
         21 . A light-emitting diode assembly including the reflector defined in  claim 18 . 
     
     
         22 . A reflector as defined in  claim 18 , wherein the titanium dioxide includes an organic coating, the organic coating comprising a carboxylic acid, a polyol, an alkanolamine, or a silicon compound. 
     
     
         23 . A reflector for a light-emitting diode comprising:
 a housing defining a cavity, the cavity having a shape configured to surround a light-emitting diode, the housing being comprised of a polymer composition comprising about 40 to about 95 weight percent poly(1,4-cyclohexanedimethanol terephthalate); from about 15 percent to about 50 percent by weight of a rutile form of titanium dioxide; and at least one polymeric toughener, the polymeric toughener comprising an acrylate polymer or a methacrylate polymer, and wherein the housing has a reflectance at 460 nm of at least 72 percent when measured at a surface temperature of 75° C. and at a distance of 4 centimeters from a light source.   
     
     
         24 . A reflector as defined in  claim 23 , wherein the housing has a reflectance at 460 nm of at least 76 percent when measured at a surface temperature of 75° C. and at a distance of 4 centimeters from a light source, and wherein the housing has a whiteness index after being aged at 200° C. for two hours of at least 44. 
     
     
         25 . A reflector as defined in  claim 23 , wherein the housing has a reflectance of 460 nm of at least 82 percent when measured at a surface temperature of 75° C. and at a distance of 4 centimeters from a light source. 
     
     
         26 . The housing of  claim 23 , wherein the cavity has a cylindrical, conical, or parabolic shape. 
     
     
         27 . The housing of  claim 23 , wherein the cavity defines walls that are parallel or substantially parallel to a light-emitting diode contained in the cavity. 
     
     
         28 . The housing of  claim 23 , further comprising a lens formed over the cavity. 
     
     
         29 . The housing of  claim 23 , wherein the titanium dioxide includes an inorganic coating. 
     
     
         30 . The housing of  claim 29 , wherein the coating comprises alumina. 
     
     
         31 . A reflector as defined in  claim 23 , wherein the titanium dioxide includes an organic coating. 
     
     
         32 . A reflector as defined in  claim 31 , wherein the organic coating comprises a carboxylic acid, a polyol, an alkanolamine, or a silicon compound. 
     
     
         33 . A reflector as defined in  claim 29 , wherein the inorganic coating comprises a metal oxide. 
     
     
         34 . A reflector as defined in  claim 33 , wherein the reflector further includes an organic coating. 
     
     
         35 . A reflector as defined in  claim 23 , wherein the polymeric toughener comprises an ethylene/(meth)acrylate copolymer. 
     
     
         36 . A reflector as defined in  claim 23 , wherein the polymeric toughener comprises a glycidyl methacrylate terpolymer. 
     
     
         37 . A reflector as defined in  claim 23 , wherein the polymeric toughener comprises a combination of an ethylene/(meth)acrylate copolymer and a glycidyl methacrylate terpolymer.