Thermally-stable photopolymer composition and light transmissive device

Abstract

A photopolymerizable composition for use in forming a photopolymer composition for use in forming the light transmissive regions of light transmissive devices, and such devices.

What is claimed is:  
     
         1 . A photopolymerizable composition comprising: 
 one or more ethylenically unsaturated monomers selected from the group consisting of aryl acrylates and methacrylates; and    a photoinitiator capable of activating polymerization of said monomers when said composition is exposed to actinic radiation,    wherein said composition is capable of being polymerized to form a photopolymer which on exposure to a temperature of 190° C. in air for 24 hrs. exhibits a coloration on the Gardner Color Scale equal to or less than 8 as determined by ASTM D1544-80 and which exhibits no cracking or delamination from a glass substrate as defined by ASTM D 4538-90A on exposure of same to a temperature of 190° C. for 24 hrs. in air.    
     
     
         2 . The composition of    claim 1    wherein said aryl acrylate and methacrylates are selected from the group consisting of multi-functional aryl acrylates.  
     
     
         3 . The composition of    claim 2    wherein said coloration is equal to or less than about 6 on the Gardner Color Scale.  
     
     
         4 . The composition of    claim 3    wherein said coloration is equal to or less than about 5 on the Gardner Color Scale.  
     
     
         5 . The composition of    claim 3    wherein aryl acrylates are selected from the group consisting of bisphenol-A acrylates.  
     
     
         6 . The composition of    claim 5    wherein said bisphenol-A acrylates are selected from the group consisting of alkoxylated bisphenol-A acrylates.  
     
     
         7 . The compostion of    claim 6    wherein said alkoxylated bisphenol-A acrylates are selected from the group consisting of ethoxylated bisphenol A diacrylate, ethoxylated hexafluoro bisphenol A diacrylate and propoxylated bisphenol A diacrylate.  
     
     
         8 . The composition of    claim 7    wherein said alkoxylated bisphenol-A acrylate is ethoxylated bisphenol A diacrylate.  
     
     
         9 . The composition of    claim 1    wherein said photoinitiator is a free radical photoinitiator selected from the group consisting of 1-hydroxy-cyclohexyl-phenyl ketone (Irgacure 184), benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzophenone, benzidimethyl ketal (Irgacure 651), α,α-diethyloxy acetophenone, α,α-dimethyloxy-α-hydroxy acetophenone (Darocur 1173), 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-propan-1-one (Darocur 2959), 2-methyl-1-[4-methylthio)phenyl]-2-morpholino-propan-1-one (Irgacure 907), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one (Irgacure 369), poly{1-[4-(1-methylvinyl)phenyl]-2-methyl-propan-1-one} (Esacure KIP), [4-(4-methylphenylthio)phenyl]phenylmethanonone (Quantacure BMS) and di-campherquinone.  
     
     
         10 . The composition of    claim 9    wherein said photoiniator is a free radical photoinitiator selected from the group consisting of benzidimethyl ketal (Irgacure 651), α,α-diethyloxy acetophenone, α,α-dimethyloxy-α-hydroxy acetophenone (Darocur 1173), 1-hydroxy-cyclohexyl-phenyl ketone (Irgacure 184), 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-propan-1-one (Darocur 2959), 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one (Irgacure 907), and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one (Irgacure 369).  
     
     
         11 . The composition of    claim 10    wherein said photoiniator is a free radical photoinitiators selected from the group consisting of benzidimethyl ketal (Irgacure 651), α,α-dimethyloxy-α-hydroxy acetophenone (Darocur 1173), 1-hydroxy-cyclohexyl-phenyl ketone (Irgacure 184), and 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-propan-1-one (Darocur 2959)  
     
     
         12 . The composition of    claim 1    which further comprises a second aliphatic ethylenically unsaturated monomer.  
     
     
         13 . The composition of    claim 12    wherein said second monomer is selected from the group consisting of aliphatic acrylate and methacrylate monomers.  
     
     
         14 . The composition of    claim 13    wherein said second monomer is selected from the group consisting of multifunctional aliphatic acrylate and methacrylate monomers.  
     
     
         15 . The composition of    claim 14    wherein said second monomer is selected from the group consisting of multifunctional aliphatic acrylate monomers.  
     
     
         16 . The composition of    claim 15    wherein said second monomer is selected from the group consisting of 1,6-hexanediol diacrylate, trimethylol propane triacrylate, pentaerythritol triacrylate, ethoxylated trimetholopropane triacrylate, glyceryl proprorylated triacylate, pentaerythritol tetracrylate, dipentaerythritol pentaacrylate and di(trimethylolpropane) tetraacrylate.  
     
     
         17 . The composition of    claim 16    wherein said second monomer is 1,6-hexanediol diacrylate, trimethylol propane triacrylate and ethoxylated trimethylol propane triacrylate  
     
     
         18 . The composition of    claim 1    which further comprises a stabilizer.  
     
     
         19 . The composition of    claim 18    wherein said composition exhibits a coloration equal to or less than about 4 on the Gardner Color Scale.  
     
     
         20 . The composition of    claim 19    wherein said coloration is equal to or less than about 3 on the Gardner Color Scale.  
     
     
         21 . The composition of    claim 20    wherein said stabilizer is an antioxidant.  
     
     
         22 . The composition of    claim 21    wherein said antioxidant is selected from the group consisting of substituted phenols.  
     
     
         23 . The composition of    claim 22    wherein said substituted phenols are selected from the group consisting of 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl)-4-hydroxybenzyl)benzene, 1,1,3-tris-(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 4,4′-butylidene-bis-(6-tert-butyl-3-methylphenol, 4,4′-thiobis-(6-tert-butyl-3-methylphenol, tris-(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, cetyl-3,5-di-tert-butyl-4-hydroxybenzene (Cyasorb UV 2908), 3,5-di-tert-butyl-4-hydroxybenzoic acid, 1,3,5-tris-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) (Cyasorb 1790), stearyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)proprionate (Irganox 1076), pentaerythritol tetrabis(3,5-di-tert-butyl-4-hydroxyphenyl) (Irganox 1010), and thiodiethylene-bis-(3,5-di-tert-butyl-4-hydroxy)hydrocinnamate (Irganox 1035).  
     
     
         24 . The composition of    claim 23    wherein said antioxidant is selected from the group consisting of pentaerythritol tetrabis(3,5-di-tert-butyl-4-hydroxyphenyl) (Irganox 1010), thiodiethylene-bis-(3,5-di-tert-butyl-4-hydroxy)hydrocinnamate (Irganox 1035), and stearyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)proprionate (Irganox 1076).  
     
     
         25 . The compostion of    claim 1    which comprises: 
 a first multifunctional bisphenol A acrylate monomer;  
 a second acrylate or methacrylate monomer; and  
 an anti-oxidant.  
 
     
     
         26 . The composition of    claim 25    wherein said first monomer is ethoxylated bisphenol A diacrylate and said second monomer is trimethylol propane triacrylate, di-(trimethylolpropane) tetraacrylate and trimethylol propane acrylate.  
     
     
         27 . The compostion of    claim 26    wherein said antioxidant is pentaerthritol tetra bis(3,5-di-tert-butyl-4-hydroxy phenol), thiodiethylene-bis-3,5(di(tert-butyl)-4-hydroxy) hydrocinnamate), stearyl-3-(3,5-di-(tert-butyl)-4-hydroxy phenyl) propionate, and cetyl-3,5-di(tert butyl)-4-hydroxy benezene.  
     
     
         28 . A photopolymer formed by photoinitiated polymerization of the composition of    claim 1    which on exposure to a temperature of 190° C. in air for 24 hrs. exhibits a coloration on the Gardner Color Scale equal to or less than 8 as determined by ASTM D1544-80 and which exhibits no cracking or delamination from a glass substrate as defined by ASTM D 4538-90A on exposure of same to a temperature of 190° C. for 24 hrs. in air.  
     
     
         29 . An optical element comprising a light transmissive region formed from the photopolymer of    claim 28   .  
     
     
         30 . A planar optical waveguide comprising a light transmissive region formed from the photopolymer of    claim 28   .  
     
     
         31 . A method for fabricating optical elements comprising placing a layer of the composition of    claim 1    on a substrate, exposing said layer to a pattern of actinic radiation to form an exposed pattern on the surface of said substrate and developing said layer with an organic solvent to create a relief image in the form of said pattern.  
     
     
         32 . The method of    claim 31    which further comprises overcoating said relief image with a polymer composition of differing refractive index.  
     
     
         33 . A method for fabricating optical waveguide structures which comprises placing a layer of the composition of    claim 1    on a lower refractive index substrate, exposing said layer to a pattern of actinic radiation to form an exposed pattern on the surface of said substrate and developing said layer with an organic solvent to create a relief image in the form of said pattern.  
     
     
         34 . The method of    claim 33    which further comprises overcoating said relief image with a polymer composition of differing refractive index.