A toner comprising a toner particle that contains a binder resin, wherein the surface of the toner particle has a reaction product of a polyhydric acid and a compound that contains a group 4 element.

A toner having a toner particle having a plurality of fine particles on the surface of a toner base particle, the toner base particle contains a binder resin, wherein a fine particle layer A constituted of a plurality of the fine particles is observed in an EDX mapping image of the constituent elements in a cross section of the toner particle as provided by EDX of the toner particle cross section observed using TEM; a fine particle B, containing a metal compound containing at least one metal element M selected from all the metal elements belonging to Groups 3 to 13, is observed in the fine particle layer A; and the number-average particle diameter D of the fine particle B, the average value H of the thickness of the fine particle layer A, and the standard deviation S on the thickness of the fine particle layer A satisfy prescribed relationships.

A toner comprising a toner particle comprising a binder resin, wherein a layer comprising an organosilicon condensate is present on the surface of the toner particle; the layer comprising the organosilicon condensate further comprises a reaction product of a compound comprising at least one metal element selected from all the metal elements belonging to Groups 3 to 13, and a polyhydric acid; in a backscattered electron image of the toner captured at a magnification of 50,000 times by using a scanning electron microscope, an average value of an area of the reaction product is from 10 nm.sup.2 to 5000 nm.sup.2, and a coefficient of variation of the area of the reaction product is not more than 10.0.

To provide an efficient method for producing a negatively chargeable toner in which a carbon black (as a colorant) is well dispersed and which has high chargeability, has excellent transfer efficiency, prevent a white spot and provides an image with sufficient image density. Disclosed is a method for producing a negatively chargeable toner, the method including: a suspension step of obtaining a suspension in which droplets of a polymerizable monomer composition containing at least a polymerizable monomer, a carbon black, a softening agent and a charge control agent, which is a specific, sulfonic acid group-containing copolymer, are dispersed, by suspending the polymerizable monomer composition in an aqueous dispersion medium containing a dispersion stabilizer, and a step of obtaining colored resin particles by suspension polymerization using the suspension in the presence of a polymerization initiator.

A toner includes a europium complex represented by the following Chemical formula

##STR00001##

where A represents 2-naphthyl group, 2-naphthyl group having a substitution group selected from the group consisting of an alkyl group, an alkoxy group, and a halogen, R represents a fluoroalkyl group having one to three carbon atoms or a methyl group, and R.sup.1, R.sup.2, R.sup.3, and R.sup.4 each, independently represent hydrogen atoms, alkyl groups, or aryl groups, wherein the toner has a hydroxyl value of from 20 to 40 mgKOH/g.

A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.010.sup.4 N, of from 200 MPa to 1,100 MPa.

A toner comprising an external additive A, and a toner particle containing a binder resin and a colorant, wherein the external additive A: i) is an external additive that has a charge control agent on the surface thereof; ii) has a wall friction angle calculated from the following formula (1) of not more than 25.0
=/5.0formula (1);
iii) has a number-average particle diameter (D1) of primary particles of at least 70 nm and not more than 500 nm; and iv) has a solidity as given by the following formula (2) of at least 0.40 and not more than 0.90
solidity=area of external additive A/area of region encompassed by envelope for external additive A formula (2).

An electrophotographic toner set, an image forming apparatus, and an image forming method include a developer toner and a replenishment toner. The developer toner and the replenishment toner each include toner particles, and silica particles and titania particles provided on the surfaces of the toner particles. The silica particles have a BET specific surface area of 15 to 95 m.sup.2/g and are surface-treated with a silicone oil. The relationship between the content of the silica particles of the developer toner and the content of the silica particles of the replenishment toner, and the relationship between the content of the titania particles of the developer toner and the content of the titania particles of the replenishment toner each have particular values.

A toner comprising a toner particle that contains a binder resin and a release agent, wherein the toner particle has a surface layer that contains an organosilicon polymer and the luminance histogram of a backscattered electron image of the toner particle has two peak values P1 and P2 and a minimum value V between P1 and P2, P2 originates from the organosilicon polymer, and the luminance giving P1 and P2 are in specific ranges, percentages for P1 and P2 are each at least 0.50%, and using the luminance Bl at V as a reference point, specific relationships are satisfied by A1, AV, and A2, where A1 is the total number of pixels at luminance from 0 to (Bl30), AV is the total number of pixels at luminance from (Bl29) to (Bl+29), and A2 is the total number of pixels at luminance from (Bl+30) to 255.

A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.010.sup.4 N, of from 200 MPa to 1,100 MPa.