Composite material and production process of dispersant

Abstract

A composite material is constituted by fine nano-oxide particles, a dispersant, and a transparent resin material. The dispersant includes a polymer of vinyl monomer having a binding acidic group. When φ is a dimensionless number defined by an average particle size (nm) of the fine nano-oxide particles divided by nm, the polymer has a degree of polymerization of an integer of 3 or more and 8 ×φ or less with the proviso that the integer is a numerical value obtained by dropping a decimal fraction. The composite material is produced through a step of obtaining a dispersant comprising a polymer by polymerizing a vinyl monomer having a binding acidic group in the presence of polyamine or in an aqueous dilute dispersion, and a step of mixing the dispersant, fine nano-oxide particles, and a transparent resin material.

1 . A composite material comprising:
 nano-oxide particles obtained by hydrothermal synthesis having an average particle size of 10 nm or less;   a dispersant; and   a transparent resin material,   wherein the dispersant contains a polymer comprising a vinyl monomer in a dispersion solution containing 10 wt. % or less of the vinyl monomer for binding with the nano-oxide particles,   wherein the polymer has a degree of polymerization of an integer of 4-10 with the proviso that the integer is a numerical value obtained by dropping a decimal fraction, and      represented      
       
         
           
           
               
               
           
         
         wherein R 1  is hydrogen atom or methyl group; R 2  is alkyl group, halogen atom, or hydrogen atom; and n is an integer of 1 or more. 
       
     
     
         2 . A material according to  claim 1 , wherein n is an integer of 6 or less in the formula (1). 
     
     
         3 . A material according to  claim 1 , wherein the dispersant and the nano-oxide particles have a weight ratio of 1/99 to 80/20, and the nano-oxide particles and the transparent resin material have a weight ratio of 0.6/99 to 80/20. 
     
     
         4 . A material according to  claim 1 , wherein the nano-oxide particles are particles of an oxide selected from the group consisting of aluminum oxide, titanium oxide, niobium oxide, tin oxide, indium oxide, zirconium oxide, lanthanum oxide, cadmium oxide, hafnium oxide, erbium oxide, neodymium oxide, cerium oxide, dysprosium oxide, and a mixed oxide of these oxides. 
     
     
         5 . A lens comprising:
 a composite material, according to  claim 1 , which has been molded.   
     
     
         6 . A production process of a composite material, comprising:
 a step of obtaining a dispersant comprising a polymer by polymerizing a vinyl monomer in a dispersion solution containing 10 wt. % or less of the vinyl monomer; and   a step of mixing the dispersant, nano-oxide particles obtained by hydrothermal synthesis having an average particle size of 10 nm or less, and a transparent resin material,   wherein the polymer has a degree of polymerization of an integer of 4-10 with the proviso that the integer is a numerical value obtained by dropping a decimal fraction, and   wherein the vinyl monomer is represented by t]   
       
         
           
           
               
               
           
         
       
       wherein R 1  is hydrogen atom or methyl group; R 2  is alkyl group, halogen atom, or hydrogen atom; and n is an integer of 1 or more. 
     
     
         7 . A material according to  claim 1 , wherein n is an integer of 6 or less in the formula (1). 
     
     
         8 . A production process of a composite material, comprising:
 a step of obtaining a dispersant comprising a polymer by polymerizing a vinyl monomer in a dispersion solution containing 10 wt. % or less of the vinyl monomer in the presence of polyamine; and   a step of mixing the dispersant, nano-oxide particles obtained by hydrothermal synthesis having an average particle size of 10 nm or less, and a transparent resin material,   wherein the polymer has a degree of polymerization of an integer of 4-10 with the proviso that the integer is a numerical value obtained by dropping a decimal fraction, and   wherein the vinyl monomer is represented by the following formula (1):   
       
         
           
           
               
               
           
         
         wherein R 1  is hydrogen atom or methyl group; R 2  is alkyl group, halogen atom, or hydrogen atom; and n is an integer of 1 or more. 
       
     
     
         9 . A material according to  claim 1 , wherein n is an integer of 6 or less in the formula (1). 
     
     
         10 . A production process of a dispersant, for nano-oxide particles obtained by hydrothermal synthesis having an average particle size of 10 nm or less, the dispersant containing a polymer comprising a vinyl monomer; the production process comprising:
 a step of polymerizing the vinyl monomer having the acidic group in a dispersion solution containing 10 wt. % or less of the vinyl monomer,   wherein the polymer has a degree of polymerization of an integer of 4-10 with the proviso that the integer is a numerical value obtained by dropping a decimal fraction, and   wherein the vinyl monomer is represented   
       
         
           
           
               
               
           
         
         wherein R 1  is hydrogen atom or methyl group; R 2  is alkyl group, halogen atom, or hydrogen atom; and n is an integer of 1 or more. 
       
     
     
         11 . A material according to  claim 1 , wherein n is an integer of 6 or less in the formula (1). 
     
     
         12 . A production process of a dispersant, for nano-oxide particles obtained by hydrothermal synthesis having an average particle size of 10 nm or less, the dispersant containing a polymer comprising a vinyl monomer; the production process comprising:
 a step of polymerizing the vinyl monomer having the acidic group in a dispersion solution containing 10 wt. % or less of the vinyl monomer in the presence of polyamine,   wherein the polymer has a degree of polymerization of an integer of 4-10 with the proviso that the integer is a numerical value obtained by dropping a decimal fraction, and   wherein the vinyl monomer is represented by the following formula (1):   
       
         
           
           
               
               
           
         
         wherein R 1  is hydrogen atom or methyl group; R 2  is alkyl group, halogen atom, or hydrogen atom; and n an integer of is 1 or more. 
       
     
     
         13 . A material according to  claim 1 , wherein n is an integer of 6 or less in the formula (1).