A fine particle of a silicon polymer, wherein the fine particle has pores; the total pore volume of the fine particle is 0.35 to 1.00 cm.sup.3/g; a number-average primary particle diameter of the fine particle is 0.05 to 0.30 μm; the silicon polymer has a siloxane bond and an Si—R.sup.1 bond; R.sup.1 represents an alkyl group having 1 to 6 carbon atoms; and designating, with reference to a chart obtained by .sup.29Si-NMR measurement of the fine particle, A as a total peak area corresponding to the silicon polymer, and B as a peak area corresponding to Si—R.sup.1, A and B satisfy a following formula (1):

10.0≤B/A×100≤45.0   (1).

A toner comprising a toner particle, wherein the toner particle includes a toner base particle containing a binder resin and includes a protruded portion on a surface of the toner base particle; the protruded portion comprises an organosilicon polymer and a polyhydric acid metal salt; and the polyhydric acid metal salt is present on a surface of the protruded portion.

The toner for developing electrostatic images is less likely to cause toner ejection and is excellent in printing durability. The toner includes colored resin particles and external additives. The external additives includes an external additive A and an external additive B; wherein the external additive A is silica particles being surface-hydrophobized with a specific hydrophobizing agent and having a specific number average particle diameter; and wherein the external additive B is silicone resin particles having a ratio (BS/TS) of a BET specific surface area (BS) to a theoretical specific surface area (TS) in a range of from 3.0 to 30.0, and having a specific number average particle diameter.

A toner having a toner particle including a toner base particle and an organosilicon polymer coating the toner base particle, wherein when S1 (μm.sup.2) is a total area of a non-coated part not coated with the organosilicon polymer on an outermost surface of the toner particle, S2 (μm.sup.2) is a total area of a coated part coated with the organosilicon polymer on the outermost surface of the toner particle, and SA1 (μm.sup.2) is a total of areas of non-coated part domains D1 with an area of not more than 0.10 μm.sup.2 in size in the non-coated part not coated with the organosilicon polymer, formulae (1) and (2) below are satisfied.
0.45≤[S2/(S1+S2)]≤0.65  (1)
(SA1/S1)≥0.50  (2)

A toner having: a toner particle containing a binder resin including a first resin that is a crystalline resin and a second resin that is an amorphous resin; and a fine particle on a surface of the toner particle, wherein the first resin contains a specific ratio of a specific monomer unit, an acid value of the first resin and an acid value of the second resin arc within specific ranges, a domain-matrix structure formed of a matrix containing the first resin and domains containing the second resin appears in cross -sectional observation of the toner, and the fine particle has on the surface a compound containing nitrogen atoms bound or adsorbed thereon.

An organic polymeric particle including an optional first monomer comprising a hydrophobic monomer; a second monomer comprising two or more vinyl groups; an optional third monomer comprising an amine; and a vinyl siloxane polymerizable monomer.

An antimicrobial toner particle composition is disclosed. The antimicrobial toner particle composition includes a binder resin, and an antimicrobial material in an effective antimicrobial amount comprising copper oxide. An image forming apparatus is also disclosed, capable of forming a fused antimicrobial image on a recording medium.

A layered inorganic mineral including a surface treated with a fluorine-containing compound, where the layered inoganic mineral that can be favorably used for a toner that is excellent in high charging ability, charging stability, and low temperature fixing ability, and that can exhibits high reliability during cleaning.

A silicone oil-treated silica particle according to the present invention includes a silica particle body and silicone oil. The silica particle body has a BET specific surface area of 70 m.sup.2/g to 120 m.sup.2/g. The silica particle body has been surface-treated with the silicone oil. The amount of free silicone oil liberated from the surface of the silica particle body in the silicone oil accounts for 2.0 mass % to 5.0 mass % with respect to the silica particle body. A surface-treated styrene acrylic resin particle, in which 2 parts by mass of the silicone oil-treated silica particle has been added to 100 parts by mass of a styrene acrylic resin particle having a particle size median of 5 μm to 8 μm, has a degree of agglomeration of 18 % or less.

Provided is a positive-charging toner having a toner particle that contains a binder resin, the binder resin contains a polymer A having a first monomer unit derived from a first polymerizable monomer, and a second monomer unit derived from a second polymerizable monomer, the first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic acid esters having a C18 to C36 alkyl group, the content of the first monomer unit in the polymer A is 5.0 to 60.0 mol % and the content of the second monomer unit is 20.0 to 95.0 mol %, SP.sub.11 of the first monomer unit and SP.sub.21 of the second monomer unit satisfy 3.00≤(SP.sub.21−SP.sub.11)≤25.00, and the work function of the toner is 5.0 to 5.4 V.