Photosensitive coloring composition, color filter substrate and semitransmissive type liquid crystal display device

Abstract

A photosensitive coloring composition including a photo-polymerizable monomer, a resinous binder, a polymerization initiator, a coloring agent and a solvent, and having an exposure sensitivity property in which γ (=tan θ) is confined to 1.33 or more and a residual rate of a film of the photosensitive coloring composition after development is 0% at an exposure dose of not more than 23% of the minimum exposure dose that makes the residual rate of the film not lower than 85%, when a rising angle of an exposure sensitivity curve is defined as θ in the exposure sensitivity curve to be derived by plotting exposure sensitivity in coordinates with an abscissa thereof representing common logarithm of the exposure dose and with an ordinate thereof representing the residual rate of the film after development.

1 . A photosensitive coloring composition which comprises a photo-polymerizable monomer, a resinous binder, a polymerization initiator, a coloring agent and a solvent; and has an exposure sensitivity property in which γ (=tan θ) is confined to 1.33 or more and a residual rate of a film of the photosensitive coloring composition after development is 0% at an exposure dose of not more than 23% of the minimum exposure dose that makes the residual rate of the film not lower than 85%, when a rising angle of an exposure sensitivity curve is defined as θ in the exposure sensitivity curve to be derived by plotting exposure sensitivity in coordinates with an abscissa thereof representing common logarithm of the exposure dose and with an ordinate thereof representing the residual rate of the film after development. 
   
   
       2 . The photosensitive coloring composition according to  claim 1 , wherein γ (=tan θ) is confined to 1.4 or more and the residual rate of the film after development is 0% at the exposure dose of not more than 25% of the minimum exposure dose that makes the residual rate of the film not lower than 85%. 
   
   
       3 . The photosensitive coloring composition according to  claim 1 , which further comprises a polymerization inhibitor represented by the following chemical formula (I): 
     
       
         
         
             
             
         
       
       wherein R 1  is hydroxyl group or alkoxy group; and R 2  is C n H 2n+1  (n=0−4). 
     
   
   
       4 . The photosensitive coloring composition according to  claim 3 , wherein the polymerization inhibitor is hydroquinone or methoquinone. 
   
   
       5 . The photosensitive coloring composition according to  claim 3 , wherein the polymerization inhibitor is contained at a ratio of 0.001-0.05% by weight based on a total weight of solid matter of the photosensitive coloring composition. 
   
   
       6 . The photosensitive coloring composition according to  claim 1 , wherein the polymerization initiator is an oxime ester-based polymerization initiator. 
   
   
       7 . The photosensitive coloring composition according to  claim 6 , wherein the oxime ester-based polymerization initiator is selected from the group consisting of 1,2-octane dione, 1-[4-(phenylthio)-2-(O-benzoyl oxime)], and O-(acetyl)-N-(1-phenyl-2-oxo-2-(4′-methoxy-naphthyl)ethylidene)hydroxylamine. 
   
   
       8 . The photosensitive coloring composition according to  claim 1 , wherein the polymerization initiator is formed of a combination of an oxime ester-based polymerization initiator with at least one kind of other polymerization initiator selected from the group consisting of an acetophenone-based compound, a benzoin-based compound, a benzophenone-based compound, a thioxanthone-based compound, a triazine-based compound, a phosphine-based compound, a quinone-based compound, a borate-based compound, a carbazole-based compound, an imidazole-based compound, and a titanocene-based compound. 
   
   
       9 . A color filter substrate to be disposed on the observer's side surface of a liquid crystal display device, comprising:
 a transparent substrate; and   a transparent color layer disposed on each of a large number of pixel regions which are formed by partitioning a surface of the transparent substrate;   wherein the pixel region is divided into a transmissive portion and a reflective portion, the transmissive portion being assigned to colorize a transmitted light from a light source arranged on the rear surface side of the liquid crystal display device and the reflective portion being assigned to colorized a reflected light to be derived from reflection of an external light entering from the observer's side; and wherein a through-hole is formed in a region of the transparent color layer where the reflective portion is located, and part of the transparent color layer is formed of a cured layer of a photosensitive coloring composition comprising a photo-polymerizable monomer, a resinous binder, a polymerization initiator, a coloring agent and a solvent;   the photosensitive coloring composition having an exposure sensitivity property in which γ (=tan θ) is confined to 1.33 or more and a residual rate of a film of the photosensitive coloring composition after development is 0% at an exposure dose of not more than 23% of the minimum exposure dose that makes the residual rate of the film not lower than 85%, when a rising angle of an exposure sensitivity curve is defined as 0 in the exposure sensitivity curve to be derived by plotting exposure sensitivity in coordinates with an abscissa thereof representing common logarithm of the exposure dose and with an ordinate thereof representing the residual rate of the film after development.   
   
   
       10 . A semitransmissive type liquid crystal display device comprising:
 the color filter substrate claimed in  claim 9 ;   an array substrate disposed to face the color filter substrate; and   a liquid crystal layer interposed between the color filter substrate and the array substrate.