Polymerizable composition comprising low molecular weight organic component

Abstract

Polymerizable compositions comprising particularly useful for brightness enhancing films.

1 . A brightness enhancing film comprising: 
 a brightness enhancing polymerized structure comprising the reaction product of a substantially solvent free polymerizable composition comprising    an organic component comprising one or more ethylenically unsaturated monomers,    wherein the organic phase is free of oligomeric monomer having a number average molecular weight of greater than 450 g/mole; and    at least 10 wt-% inorganic nanoparticles.    
     
     
         2 . The brightness enhancing film of  claim 1  wherein the polymerizable composition has a refractive index of at least 1.47, a refractive index of at least 1.52, a refractive index of at least 1.55, or a refractive index of at least 1.60.  
     
     
         3 . The brightness enhancing film of  claim 1  wherein the organic component has a viscosity of less than 1000 cps at 180° F., a viscosity of less than 1000 cps at 160° F., a viscosity of less than 1000 cps at 140° F., a viscosity of less than 1000 cps at 120° F., a viscosity of less than 800 cps at 120° F., or a viscosity of less than 600 cps at 120° F.  
     
     
         4 . The brightness enhancing film of  1  wherein the polymerizable composition comprises photoinitiator.  
     
     
         5 . The brightness enhancing film of  claim 4  where in the polymerizable composition is cured by means of ultraviolet radiation.  
     
     
         6 . The brightness enhancing film of  claim 1  wherein the organic component comprises at least one monomer having a refractive index of at least 1.47.  
     
     
         7 . The brightness enhancing film of  claim 6  wherein the organic component comprises a monomer selected from the group consisting of phenoxy ethyl acrylate; phenylthio ethyl acrylate; 2-naphthylthio ethyl acrylate; 1-naphthylthio ethyl acrylate; 2,4,6-tribromophenoxy ethyl acrylate; 2,4-dibromophenoxy ethyl acrylate; 2-bromophenoxy ethyl acrylate; 1-naphthyloxy ethyl acrylate; 2-naphthyloxy ethyl acrylate; phenoxy 2-methylethyl acrylate; phenoxyethoxy ethyl acrylate; 3-phenoxy-2-hydroxy propyl acrylate; 2-phenylphenoxy ethyl acrylate; 4-phenylphenoxy ethyl acrylate; 2,4-dibromo-6-sec-butylphenyl acrylate; 2,4-dibromo-6-isopropylphenyl acrylate; benzyl acrylate; phenyl acrylate; 2,4,6-tribromophenyl acrylate; and mixtures thereof.  
     
     
         8 . The brightness enhancing film of  claim 1  wherein the organic component comprises at least one monomer having a refractive index of at least 1.50 in combination with a second monomer having a refractive index of less than 1.50.  
     
     
         9 . The brightness enhancing film of  claim 8  wherein the second monomer has a refractive index of less than 1.47.  
     
     
         10 . The brightness enhancing film of  claim 1  wherein at least one monomer of the organic component has at least two ethylenically unsaturated groups.  
     
     
         11 . The brightness enhancing film of  claim 10  where the monomer is selected from hexanediol diacrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane ethoxylate tri(meth)acrylate, glyceryl tri(meth)acrylate, pentaerythritol propoxylate tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and mixtures thereof.  
     
     
         12 . The brightness enhancing film of  claim 1 , wherein the polymerized structure has a plurality of ridges extending along a first surface.  
     
     
         13 . The brightness enhancing film of  claim 12  wherein the ridges have rounded apexes having a radius ranging from 4 to 15 micrometers.  
     
     
         14 . The brightness enhancing film of  claim 1 , wherein the inorganic nanoparticles have a primary particle size in a range selected from 1 nm to 100 nm, 5 nm to 75 nm, or 10 nm to 30 nm.  
     
     
         15 . The brightness enhancing film according to  claim 1 , wherein the inorganic nanoparticles comprise 10 wt-% to 60 wt-% or 10 wt-% to 40 wt-% of the polymerized structure.  
     
     
         16 . The brightness enhancing film according to  claim 1 , wherein the nanoparticles are selected from silica, zirconia, titania, antimony oxides, alumina, tin oxides, mixed metal oxides thereof, or mixtures thereof.  
     
     
         17 . The brightness enhancing film according to  claim 1 , wherein the nanoparticles are surface modified such that the nanoparticles are polymerizable with the organic component.  
     
     
         18 . The brightness enhancing film according to  claim 1  wherein the base layer is a polarizing layer.  
     
     
         19 . The brightness enhancing film according to  claim 18  wherein the base layer is a reflective polarizing layer.  
     
     
         20 . A device comprising: 
 (a) a lighting device having a light-emitting surface; and    (b) the brightness enhancing film of  claim 1  placed substantially parallel to said light-emitting surface.    
     
     
         21 . The device according to  claim 20 , wherein the lighting device is a back-lit display device or a liquid crystal display device.  
     
     
         22 . The device according to  claim 20 , wherein the device is selected from a handheld device, a computer display and a television.  
     
     
         23 . The brightness enhancing film of  claim 1  wherein the film is a turning film and the refractive index of the polymerizable composition is at least 1.44.  
     
     
         24 . The brightness enhancing film of  claim 23  wherein the film has rounded apexes having a radius ranging from 0.5 to 10 micrometers.  
     
     
         25 . An illumination device comprising: 
 (a) a lighting source having a lightguide having a light-emitting surface; and    (b) the turning film of  claim 24  placed substantially parallel to said lightguide, said turning film having a first surface and a second surface and an array of prisms formed on the first surface, the turning film disposed with the first surface disposed in relation to the light-emitting surface such that light rays exiting the light-emmiting surface of the lightguide encounter the array of prisms and are reflected and refracted by the array of prisms such that the light rays exit the turning film via the second surface and substantially along a desired angular direction,    wherein the array of prisms includes a first plurality of prisms, each of the first plurality of prisms having a first prism configuration, and a second plurality of prisms each having a second prism configuration, different than the first prism configuration, the first prism configuration and the second prism configuration being such the light rays exiting the second surface correspond to a substantially uniform sampling of the light rays entering the lightguide.    
     
     
         26 . A brightness enhancing film comprising: 
 a brightness enhancing polymerized structure comprising the reaction product of a substantially solvent free polymerizable composition comprising    an organic component comprising one or more ethylenically unsaturated monomers,    wherein the organic phase is free of oligomeric monomer having a number average molecular weight of greater than 450 g/mole and the polymerizable composition comprises at least one ingredient that comprises at least two ethylenically unsaturated groups.    
     
     
         27 . A microstructured article comprising the reaction product of a substantially solvent free polymerizable composition comprising an organic component comprising one or more ethylenically unsaturated monomers and optionally inorganic nanoparticles, wherein the organic component is free of oligomeric monomer having a number average molecular weight of greater than 450 g/mole and the polymerizable composition comprises at least one ingredient that comprises at least two (meth)acrylate groups.  
     
     
         28 . The microstructured article of  claim 27  wherein the article is retroreflective.  
     
     
         29 . The microstructured article of  claim 27  wherein the article is a flexible mold suitable for making barrier ribs fro a plasma display panel.