Fine Particles and Method of Producing Thereof, Fine Particle Dispersion Liquid, and Image Display Medium and Image Display Apparatus

Abstract

An object of the present invention is to provide white colored fine particles with high white reflectance and not easily precipitating in a dispersion medium compared to inorganic white pigments, a method of producing the fine particles, an image display medium and an image display apparatus having a high whiteness like a paper and an excellent display memorability using the fine particles. Therefore, the fine particles contain a polymer of a compound expressed by the following formula (1). In the above formula (1), R represents a hydrogen atom, a halogen atom, an alkyl group or an alkenyl group, “m” represents an integer of 1 to 10, and at least one of R represents the alkenyl group.

1 - 17 . (canceled) 
     
     
         18 . Fine particles comprising a polymer of a compound expressed by the following formula (1). 
       
         
           
           
               
               
           
         
         in the above formula (1), R represents a hydrogen atom, a halogen atom, an alkyl group or an alkenyl group, “m” represents an integer of 1 to 10, and at least one of R represents the alkenyl group. 
       
     
     
         19 . The fine particles according to  claim 18 , wherein the compound expressed by the formula (1) is any one of a compound expressed by the following formulas (3) and (4), 
       
         
           
           
               
               
           
         
         in the above formulas (3) and 4), a naphthalene ring may be substituted by at least one of an alkyl group having 1 to 12 carbon atoms and a halogen atom. 
       
     
     
         20 . The fine particles according to  claim 18 , further comprising a macromer. 
     
     
         21 . The fine particles according to  claim 20 , wherein the macromer is a silicone macromer expressed by the following formula (2), 
       
         
           
           
               
               
           
         
         in the formula (2), R 1  represents a hydrogen atom or a methyl group, R 1 ′ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, “n” represents a natural number and “x” represents an integer of 1 to 3. 
       
     
     
         22 . The fine particles according to  claim 18 , wherein the fine particles are electrophoretic particles for an image display medium. 
     
     
         23 . A method of producing fine particles comprising:
 forming fine particles by polymerizing a compound expressed any one of the following formulas (3) and (4),   
       
         
           
           
               
               
           
         
         in the above formulas (3) and (4), a naphthalene ring may be substituted by at least one of an alkyl group having 1 to 4 carbon atoms and a halogen atom. 
       
     
     
         24 . The method of producing fine particles according to  claim 23 , wherein the polymerizing is conducted in a solvent in which the compound expressed by any of the formulas (3) and (4) is soluble, and deposing the particles of an insoluble polymer to the solvent. 
     
     
         25 . The method of producing fine particles according to  claim 23 , wherein the solvent is a non-polar organic solvent. 
     
     
         26 . The method of producing fine particles according to  claim 23 , adding a macromer. 
     
     
         27 . The method of producing fine particles according to  claim 26 , wherein the macromer is a silicone macromer expressed by the following formula (2), 
       
         
           
           
               
               
           
         
         R 1  represents a hydrogen atom or a methyl group, R 1 ′ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, “n” represents a natural number and “x” represents an integer of 1 to 3. 
       
     
     
         28 . A fine particle dispersion liquid comprising:
 fine particles dispersed in a non-polar organic solvent,   wherein the fine particles comprise at least a polymer of a compound expressed by the following formula (1),   
       
         
           
           
               
               
           
         
         in the above formula (1), R represents a hydrogen atom, a halogen atom, an alkyl group or an alkenyl group, “m” represents an integer of 1 to 10, and at least one of R represents the alkenyl group. 
       
     
     
         29 . The fine particle dispersion liquid according to  claim 28 , further comprising, a charge control agent. 
     
     
         30 . The fine particle dispersion liquid according to  claim 28 , the non-polar organic solvent is colored by dissolving a dye having a color different from the fine particles. 
     
     
         31 . An image display medium comprising:
 a pair of electrodes, and   a fine particle dispersion liquid between the pair of electrodes,   wherein the fine particle dispersion liquid comprises at least fine particles dispersed in a non-polar organic solvent, wherein the fine particles comprise at least a polymer of a compound expressed by the following formula (1),   
       
         
           
           
               
               
           
         
         in the above formula (1), R represents a hydrogen atom, a halogen atom, an alkyl group or an alkenyl group, “m” represents an integer of 1 to 10, and at least one of R represents the alkenyl group. 
       
     
     
         32 . The image display medium according to  claim 31 , wherein an image is displayed by applying voltage between the pair of the electrodes to cause electrophoresis of the fine particles. 
     
     
         33 . The image display medium according to  claim 31 , wherein the fine particle dispersion liquid is contained in a microcapsule. 
     
     
         34 . An image display apparatus comprising as a display an image display medium,
 wherein the image display medium comprises at least a pair of electrodes and a fine particle dispersion liquid between the pair of electrodes, wherein the fine particle dispersion liquid comprises at least fine particles dispersed in a non-polar organic solvent, wherein the fine particles comprise at least a polymer of a compound expressed by the following formula (1),   
       
         
           
           
               
               
           
         
         in the above formula (1), R represents a hydrogen atom, a halogen atom, an alkyl group or an alkenyl group, “m” represents an integer of 1 to 10, and at least one of R represents the alkenyl group.