Silica composite particles and method of preparing the same

Abstract

Silica composite particles include silicon oxide and titanium in an amount of from 0.001% by weight to 10% by weight, wherein the silica composite particles have an average particle diameter of from 30 nm to 500 nm, a particle size distribution index of from 1.1 to 1.5, and an average degree of circularity of primary particles of from 0.5 to 0.85.

What is claimed is: 
     
         1 . Silica composite particles comprising:
 silicon oxide; and   titanium in an amount of from 0.001% by weight to 10% by weight,   wherein the silica composite particles have an average particle diameter of from 30 nm to 500 nm,   a particle size distribution index of from 1.1 to 1.5, and   an average degree of circularity of primary particles of from 0.5 to 0.85.   
     
     
         2 . The silica composite particles according to  claim 1 , wherein the amount of titanium is from 0.01% by weight to 9% by weight. 
     
     
         3 . The silica composite particles according to  claim 1 , wherein the amount of titanium is from 0.1% by weight to 5% by weight. 
     
     
         4 . The silica composite particles according to  claim 1 , wherein the average particle diameter is from 60 nm to 500 nm. 
     
     
         5 . The silica composite particles according to  claim 1 , wherein the average particle diameter is from 100 nm to 350 nm. 
     
     
         6 . The silica composite particles according to  claim 1 , wherein the average particle diameter is from 100 nm to 250 nm. 
     
     
         7 . The silica composite particles according to  claim 1 , wherein the particle size distribution index is from 1.25 to 1.40. 
     
     
         8 . The silica composite particles according to  claim 1 , wherein the average degree of circularity of the primary particles is from 0.6 to 0.8. 
     
     
         9 . A method of preparing silica composite particles comprising:
 preparing an alkali catalyst solution containing an alkali catalyst at a concentration of from 0.6 mol/L to 0.85 mol/L, in a solvent containing alcohol; and   supplying, into the alkali catalyst solution, a mixed solution of tetraalkoxysilane and an organic titanium compound in which an organic group is coupled to a titanium atom through oxygen at a supply amount of from 0.001 mol/(mol·min) to 0.01 mol/(mol·min) relative to the alcohol, and an alkali catalyst at a supply amount of from 0.1 mol to 0.4 mol, relative to 1 mol of a total supply amount of the tetraalkoxysilane and the organic titanium compound supplied per one minute.   
     
     
         10 . The method of preparing silica composite particles according to  claim 9 , wherein the concentration of the alkali catalyst is from 0.63 mol/L to 0.78 mol/L. 
     
     
         11 . The method of preparing silica composite particles according to  claim 9 , wherein the concentration of the alkali catalyst is from 0.66 mol/L to 0.75 mol/L. 
     
     
         12 . The method of preparing silica composite particles according to  claim 9 , wherein the supply amount of the mixed solution of the tetraalkoxysilane and the organic titanium compound is from 0.002 mol/(mol·min) to 0.009 mol/(mol·min) relative to the alcohol of the alkali catalyst solution. 
     
     
         13 . The method of preparing silica composite particles according to  claim 9 , wherein the supply amount of the mixed solution of the tetraalkoxysilane and the organic titanium compound is from 0.003 mol/(mol·min) to 0.008 mol/(mol·min) relative to the alcohol of the alkali catalyst solution. 
     
     
         14 . The method of preparing silica composite particles according to  claim 9 , wherein the supply amount of the alkali catalyst is from 0.14 mol to 0.35 mol relative to 1 mol of a total supply amount of the tetraalkoxysilane and the organic titanium compound supplied per one minute. 
     
     
         15 . The method of preparing silica composite particles according to  claim 9 , wherein the supply amount of the alkali catalyst is from 0.18 mol to 0.30 mol relative to 1 mol of a total supply amount of the tetraalkoxysilane and the organic titanium compound supplied per one minute.