Resin particle and method for producing the same

Abstract

A resin particle having: a resin mother particle; and silica particles external added onto the surface of the resin mother particle, wherein a primary particles of the silica particles which have a volume average particle diameter of from 100 nm to 500 nm, a particle size distribution index of from 1.40 to 1.80 and an average circularity of from 0.5 to 0.85 has a regression line expressed by the following expression (1) with respect to the circularity and the volume average particle diameter (nm): Circularity=α×(Volume average particle diameter)/1000+β  (1) wherein α is from −2.5 to −0.9, and β is from 0.8 to 1.2.

1 . A resin particle comprising:
 a resin mother particle; and   silica particles external added onto a surface of the resin mother particle,   wherein primary particles of the silica particles, the primary particles which have a volume average particle diameter of from 100 nm to 500 nm, a particle size distribution index of from 1.40 to 1.80 and an average circularity of from 0.5 to 0.85, and satisfy a regression line expressed by a following expression (1) with respect to the circularity and the volume average particle diameter (nm):
   Circularity=α×(Volume average particle diameter)/1000+β  (1)
 
   
       wherein α is from −2.5 to −0.9, and is from 0.8 to 1.2. 
     
     
         2 . The resin particle according to  claim 1 ,
 wherein a volume average particle diameter of the primary particles of the silica particles is from 100 nm to 350 nm.   
     
     
         3 . The resin particle according to  claim 1 ,
 wherein a volume average particle diameter of the primary particles of the silica particles is from 100 nm to 250 nm.   
     
     
         4 . The resin particle according to  claim 1 ,
 wherein a particle size distribution index of the primary particles of the silica particles is from 1.45 to 1.75.   
     
     
         5 . The resin particle according to  claim 1 ,
 wherein an average circularity of the primary particles of the silica particles is from 0.6 to 0.8.   
     
     
         6 . The resin particle according to  claim 1 ,
 wherein a is from −2.0 to −1.0, and β is from 0.9 to 1.1.   
     
     
         7 . The resin particle according to  claim 1 ,
 wherein a coverage of the silica particles external added onto the surface of the resin particle relative to a surface area of the resin mother particle, which is obtained by the following formula (i), is 5% to 80%:
   (√3×B×C×D/(2×π×F×E×0.001×A))×100   (i)
 
   wherein A whose unit is “g” represents an addition amount of the resin mother particle,   B whose unit is “g/cm 3 ” represents a specific gravity of the resin mother particle,   C whose unit is “gm” represents a volume average particle diameter of the resin mother particle,   D whose unit is “g” represents an addition amount of the silica particles,   E whose unit is “g/cm 3 ” represents a specific gravity of the silica particles, and   F whose unit is “nm” represents a volume average particle diameter of the silica particles.   
     
     
         8 . A method for producing a resin particle comprising:
 preparing an alkaline catalyst solution containing an alkaline catalyst in a concentration of from 0.6 mol/L to 0.85 mol/L in an alcohol-containing solvent;   supplying a tetraalkoxysilane in a supply amount of from 0.006 mol/(mol·min) to 0.009 mol/(mol·min) relative to the alcohol into the alkaline catalyst solution and also supplying an alkaline catalyst in an amount of from 0.1 mol to 0.4 mol per mole of the total supply amount of the tetraalkoxysilane to be supplied per minute to obtain silica particles; and   allowing the obtained silica particles to be externally added onto the surface of a resin mother particle.   
     
     
         9 . The method for producing the resin particle according to  claim 8 ,
 wherein the alkaline catalyst is selected from the group consisting of an ammonia, an urea, a monoamine, and a quaternary ammonium salt.   
     
     
         10 . The method for producing the resin particle according to  claim 8 ,
 wherein a content of the alkaline catalyst is from 0.63 mol/L to 0.78 mol/L.   
     
     
         11 . The method for producing the resin particle according to  claim 8 ,
 wherein the tetraalkoxysilane is selected from the group consisting of a tetramethoxysilane, a tetraethoxysilane, a tetrapropoxysilane and a tetrabutoxysilane.   
     
     
         12 . The method for producing the resin particle according to  claim 8 ,
 wherein a supply amount of the tetraalkoxysilane is from 0.0065 mol/(mol·min) to 0.0085 mol/(mol·min) relative to alcohol in the alkaline catalyst solution.   
     
     
         13 . The method for producing the resin particle according to  claim 8 ,
 wherein a supply amount of the tetraalkoxysilane is from 0.0070 mol/(mol·min) to 0.0080 mol/(mol·min) relative to alcohol in the alkaline catalyst solution.   
     
     
         14 . The method for producing the resin particle according to  claim 8 ,
 wherein a temperature in the alkaline catalyst solution at supplying the tetraalkoxysilane is from 5° C. to 50° C.   
     
     
         15 . The method for producing the resin particle according to  claim 8 , further comprising:
 treating a surface of the silica particles to a hydrophobic treatment with a hydrophobic treatment agent.