Method for producing hollow resin particles

Abstract

The method produces hollow resin particles. The method comprising steps of: preparing a mixture liquid comprising (A) a monomer comprising at least one monomer selected from the group consisting of a monovinyl monomer and a hydrophilic monomer excluding acrylonitrile and methacrylonitrile, (B) a crosslinkable monomer, (C) an oil-soluble polymerization initiator, (E) a hydrocarbon solvent, (F) a suspension stabilizer and (G) an aqueous medium; carrying out a suspension treatment of the mixture liquid to prepare a suspension; carrying out a polymerization reaction of the suspension to prepare a precursor composition; carrying out a solid-liquid separation of the precursor composition to obtain the precursor particles; and removing the hydrocarbon solvent (E) included in the precursor particles.

What is claimed is: 
     
         1 : A method for producing hollow resin particles, the method comprising steps of:
 preparing a mixture liquid comprising (A) a monomer comprising at least one monomer selected from the group consisting of a monovinyl monomer and a hydrophilic monomer excluding acrylonitrile and methacrylonitrile, (B) a crosslinkable monomer, (C) an oil-soluble polymerization initiator, (E) a hydrocarbon solvent, (F) a suspension stabilizer and (G) an aqueous medium, wherein an amount of the contained crosslinkable monomer (B) is from 25 parts by mass to 59 parts by mass provided that a total amount of the monomer (A) and the crosslinkable monomer (B) is regarded as 100 parts by mass;   carrying out a suspension treatment of the mixture liquid to prepare a suspension which comprises monomer drops comprising the hydrocarbon solvent (E) dispersed in the aqueous medium (G);   carrying out a polymerization reaction of the suspension to prepare a precursor composition comprising precursor particles each having a hollow portion including the hydrocarbon solvent (E);   carrying out a solid-liquid separation of the precursor composition to obtain the precursor particles; and   removing the hydrocarbon solvent (E) included in the precursor particles in a gaseous atmosphere to obtain the hollow resin particles.   
     
     
         2 : The method according to  claim 1 , wherein the monovinyl monomer is at least one selected from the group consisting of acrylate and methacrylate, and the hydrophilic monomer is at least one selected from the group consisting of acrylic acid and methacrylic acid. 
     
     
         3 : The method according to  claim 1 , wherein a method for solid-liquid separation of the precursor composition is centrifugation or filtration. 
     
     
         4 : The method according to  claim 1 , wherein the step of preparing the mixture liquid is a step of mixing an oil phase comprising the monomer (A), the crosslinkable monomer (B), the oil-soluble polymerization initiator (C), and the hydrocarbon solvent (E), wherein an amount of the contained crosslinkable monomer (B) is from 25 parts by mass to 59 parts by mass provided that a total amount of the monomer (A) and the crosslinkable monomer (B) is regarded as 100 parts by mass, with an aqueous phase comprising the suspension stabilizer (F) and the aqueous medium (G). 
     
     
         5 : The method according to  claim 1 , wherein a relative permittivity of the hydrocarbon solvent (E) is 3 or less at 20° C. 
     
     
         6 : The method according to  claim 1 , wherein the hydrocarbon solvent (E) is a hydrocarbon compound having 5 to 7 carbon atoms. 
     
     
         7 : The method according to  claim 1 , wherein an amount of the hydrocarbon solvent (E) is 200 parts by mass or more provided that a total amount of the monomer (A) and the crosslinkable monomer (B) is regarded as 100 parts by mass. 
     
     
         8 : The method according to  claim 1 , wherein a number average particle diameter of the obtained hollow resin particles is from 0.1 μm to 10 μm. 
     
     
         9 : The method according to  claim 1 , wherein a void ratio of the obtained hollow resin particles is from 70% to 99%.