Resin particles and method for manufacturing resin particles

Abstract

Resin particles include resin base particles and silica particles on surfaces of the resin base particles. The silica particles contain a quaternary ammonium salt and have hydrophobized surfaces. A difference (detection temperature A−detection temperature B) between a detection temperature A and a detection temperature B is more than 50° C., where the detection temperature A is a detection temperature from a pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles before cleaning, and the detection temperature B is a detection temperature from the pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles after cleaning.

What is claimed is: 
     
         1 . A method for manufacturing resin particles, the method comprising:
 producing silica particles by:
 preparing a suspension containing silica particles; 
 surface-treating the silica particles with a quaternary ammonium salt by mixing the suspension and the quaternary ammonium salt; and 
 surface-treating, with an organosilicon compound using a supercritical treatment, the silica particles surface-treated with the quaternary ammonium salt; and 
   attaching the produced silica particles to surfaces of resin base particles;   wherein the resin particles comprise:
 the resin base particles; and 
 the silica particles on surfaces of the resin base particles, the silica particles containing the quaternary ammonium salt and having hydrophobized surfaces, and 
 wherein a difference (detection temperature A−detection temperature B) between a detection temperature A and a detection temperature B is more than 50° C., where the detection temperature A is a detection temperature from a pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles before cleaning, and the detection temperature B is a detection temperature from the pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles after cleaning. 
   
     
     
         2 . A method for manufacturing resin particles, the method comprising:
 producing silica particles by:
 preparing a suspension containing silica particles; 
 surface-treating the silica particles with a quaternary ammonium salt by mixing the suspension and the quaternary ammonium salt; and 
 surface-treating, with an organosilicon compound using a supercritical treatment, the silica particles surface-treated with the quaternary ammonium salt; and 
   attaching the produced silica particles to surfaces of resin base particles;   wherein the resin particles comprise:
 the resin base particles; and 
 the silica particles on surfaces of the resin base particles, the silica particles containing the quaternary ammonium salt and having hydrophobized surfaces, and 
   wherein a ratio (F BEFORE /F AFTER ) between maximum frequencies of pore diameters of 2 nm or less in the silica particles is 0.9 or more and 1.1 or less, and a ratio (F SINTERING /F BEFORE ) between maximum frequencies of pore diameters of 2 nm or less in the silica particles is 5 or more and 20 or less,   F BEFORE : a maximum frequency of pore diameters of 2 nm or less in the silica particles before cleaning determined from a pore diameter distribution curve in nitrogen gas adsorption analysis,   F ATER : a maximum frequency of pore diameters of 2 nm or less in the silica particles after cleaning determined from a pore diameter distribution curve in nitrogen gas adsorption analysis, and   F SINTERING : a maximum frequency of pore diameters of 2 nm or less in the silica particles before cleaning and after sintering at 700° C. determined from a pore diameter distribution curve in nitrogen gas adsorption analysis.   
     
     
         3 . The method for manufacturing the resin particles according to  claim 1 , wherein the quaternary ammonium salt includes a compound represented by general formula (AM) below: 
       
         
           
           
               
               
           
         
       
       where R 1 , R 2 , R 3 , and R 4  each independently represent an optionally substituted alkyl group, aralkyl group, or aryl group, and X −  represents an anion, and where two or more of R 1 , R 2 , R 3 , and R 4  are optionally bonded to each other to form a ring. 
     
     
         4 . The method for manufacturing the resin particles according to  claim 2 , wherein the quaternary ammonium salt includes a compound represented by general formula (AM) below: 
       
         
           
           
               
               
           
         
       
       where R 1 , R 2 , R 3 , and R 4  each independently represent an optionally substituted alkyl group, aralkyl group, or aryl group, and X −  represents an anion, and where two or more of R 1 , R 2 , R 3 , and R 4  are optionally bonded to each other to form a ring. 
     
     
         5 . The method for manufacturing the resin particles according to  claim 1 , wherein the silica particles have a number-average particle diameter D50p of 5 nm or more and 200 nm or less. 
     
     
         6 . The method for manufacturing the resin particles according to  claim 1 , wherein a proportion (N/silica particles×100) of an amount N of nitrogen element in the silica particles detected by oxygen-nitrogen analysis is 0.01 or more and 1.0 or less. 
     
     
         7 . The method for manufacturing the resin particles according to  claim 1 , wherein the silica particles have an average pore diameter of 0.55 nm or more and 2.00 nm or less. 
     
     
         8 . The method for manufacturing the resin particles according to  claim 1 , wherein the silica particles further contain aluminum atoms. 
     
     
         9 . The method for manufacturing the resin particles according to  claim 1 , wherein the step of preparing a suspension containing silica particles includes:
 preparing the silica particle suspension by mixing the silica particles and an alcohol-containing solvent.   
     
     
         10 . The method for manufacturing the resin particles according to  claim 2 , wherein the step of preparing a suspension containing silica particles includes:
 preparing the silica particle suspension by mixing the silica particles and an alcohol-containing solvent.   
     
     
         11 . The method for manufacturing the resin particles according to  claim 1 , wherein the step of surface-treating, with an organosilicon compound using a supercritical treatment includes: using supercritical carbon dioxide. 
     
     
         12 . The method for manufacturing the resin particles according to  claim 2 , wherein the step of surface-treating, with an organosilicon compound using a supercritical treatment includes: using supercritical carbon dioxide.