Resin particle and method of producing the resin particle, and toner and method of producing the toner
Provided is a toner, comprising a toner particle having a core-shell structure composed of a core particle and a shell phase on a surface of the core particle, the core particle containing a resin X and a colorant, the shell phase being derived from a resin fine particle containing a resin Y, in which a relationship among a SP value of the resin X, a SP value of the resin Y, and a SP value of an organic solvent falls within a specific range, and a relationship between a number-average particle diameter of the resin fine particle when the resin fine particle is dispersed in water and a number-average particle diameter of the resin fine particle when the resin fine particle is dispersed in the organic solvent falls within a specific range.
1. A toner comprising a toner particle, the toner particle comprising a core-shell structure composed of a core particle and a shell phase on a surface of the core particle,
the core particle comprising a resin X and a colorant;
the shell phase is derived from a resin fine particle comprising a resin Y, said resin Y having a crosslinked structure and an organic polysiloxane structure represented by formula (i)
where R 1 represents an alkyl group, and n represents a polymerization degree and is an integer of 2 or more; and
said resin Y being a polymer of a monomer composition comprising a polyester having a polymerizable unsaturated group, with an average number of polymerizable unsaturated groups in one molecule of the polyester being 1.4 to 2.6, wherein
the resin fine particle swells in an organic solvent,
the resin X, the resin Y, and the organic solvent satisfy formulae (1) and (2):
1.5≦| SP X −SP Y| ≦3.1 (1)
0≦| SP SOL −( SP X −SP Y )/2|≦2.5 (2)
where SP X represents a SP value ((J/cm 3 ) 1/2 ) of resin X, SP Y represents a SP value ((J/cm 3 ) 1/2 ) of resin Y, and SP SOL represents a SP value ((J/cm 3 ) 1/2 ) of the organic solvent, and
the resin fine particle satisfies formulae (3) and (4):
80≦ A≦ 140 (3)
1.33≦(4π( B/ 2) 3 /3)/(4π( A/ 2) 3 /3)≦2.85 (4)
where “A” represents a number-average particle diameter (nm) of the resin fine particle when the resin fine particle is dispersed in water, and
“B” represents a number-average particle diameter (nm) of the resin fine particle when the resin fine particle is dispersed in the organic solvent.
2. A toner according to claim 1 , wherein the shell phase is formed through a step of bringing the core particle and the resin fine particle into contact with each other in presence of the organic solvent.
3. A toner according to claim 1 , wherein the resin X comprises a polyester as a main component and the resin Y comprises a polyester.
4. A toner according to claim 1 , wherein the SP SOL satisfies formula (7):
18.2≦ SP SOL ≦19.9 (7).
5. A toner according to claim 1 , wherein the SP Y is 24.0 (J/cm 3 ) 1/2 or less.
6. A toner according to claim 1 , wherein the monomer composition further comprises a monomer having two or more polymerizable unsaturated groups, the monomer having a weight-average molecular weight of 200 to 2,000.
7. A toner according to claim 1 , wherein the polymerizable unsaturated group of the polyester is derived from a dicarboxylic acid having a polymerizable unsaturated group and/or a diol having a polymerizable unsaturated group.