Toner
A toner comprising: a toner particle that comprises a core particle comprising a binder resin, and a shell layer comprising a thermoplastic resin on a surface of the core particle; and organosilicon polymer particles on a surface of the toner particle, wherein a peak top molecular weight of the thermoplastic resin, according to measurement by gel permeation chromatography, is 30000 to 500000, a number-average primary particle diameter of the organosilicon polymer particles is 10 nm to 500 nm, and an absolute value of a difference (ΔSP) between an SP value (SP Si ) of the organosilicon polymer particles and an SP value (SP Sh ) of the thermoplastic resin present in the shell layer is not more than 2.30.
1. A toner, comprising:
a toner particle that comprises a core particle, said core particle comprising a binder resin;
a shell layer on a surface of the core particle, said shell layer comprising a thermoplastic resin; and
organosilicon polymer particles on a surface of the toner particle, wherein
the thermoplastic resin is a polymer of styrene and at least one member selected from the group consisting of acrylic polymerizable monomers and methacrylic polymerizable monomers,
the thermoplastic resin has a peak top molecular weight of 30000 to 500000 measured by gel permeation chromatography,
the organosilicon polymer particles have a number-average primary particle diameter of 10 to 500 nm, and
an absolute value of a difference between SP values of the organosilicon polymer particles and the thermoplastic resin in the shell layer is not more than 2.30.
2. The toner according to claim 1 , wherein a glass transition temperature of the thermoplastic resin is 40 to 75° C. measured by differential scanning calorimetry.
3. The toner according to claim 1 , wherein the shell layer has an average thickness of 5 to 250 nm.
4. The toner according to claim 1 , wherein a ratio of coverage of the core particle by the shell layer is at least 30%.
5. The toner according to claim 1 , wherein a content of the organosilicon polymer particles in the toner is 0.3 to 10.0 mass %.
6. The toner according to claim 1 , wherein the organosilicon polymer particles have a structure in which a silicon atom and an oxygen atom are bonded in alternation, and have a T3 unit structure represented by R 1 —SiO 3/2 where R 1 represents a C 1-6 alkyl group or phenyl group, and
a proportion of a peak area originating with silicon having the T3 unit structure to a total peak area originating with all silicon element contained in the organosilicon polymer particles is 0.50 to 1.00 in 29 Si-NMR measurement.
7. The toner according to claim 1 , wherein an attachment index for the organosilicon polymer particles on a polycarbonate film is not more than 4.5 determined by (area ratio A for the organosilicon polymer particles transferred to the polycarbonate film/ratio of coverage B by the organosilicon polymer particles over the toner particle surface)×100.
8. The toner according to claim 1 , wherein a dispersity evaluation index for the organosilicon polymer particles on the toner surface is 0.5 to 2.0.