A toner for developing an electrostatic charge image, comprising a toner particle and an external additive, the toner particle comprising a binder resin containing a crystalline polyester resin, a colorant, and a release agent, the crystalline polyester resin comprising an alicyclic dibasic acid, a terephthalic acid, and an isophthalic acid as acid components and being contained in the toner particle in an amount of 4 to 8% by mass.

A toner containing a toner particle that contains a binder resin including a polyester resin, and a polyolefin resin having COOM that is a neutralized carboxy group with a monovalent metal ion M, wherein the polyolefin resin having COOM is a polymer in which a vinyl polymer is bonded to a polyolefin, a content of a monomer unit containing COOM in the polyolefin resin having COOM is 1 to 20 mass %, and in a FT-IR spectrum obtained through measurement of a large particle size-side particle group and a small particle size-side particle group obtained by dividing the toner into two substantially equal parts, on a number basis, a ratio of the intensity of a maximum absorption peak in a range from 1545 cm.sup.1 to 1555 cm.sup.1 with respect to the intensity of a maximum absorption peak in a range from 1713 cm.sup.1 to 1723 cm.sup.1 exhibits a specific relationship.

A toner including a toner particle including a binder resin, wherein fine particles A and B are present on a surface of the toner particle; the fine particles A are a fatty acid metal salt; the fine particles B have a specific volume resistivity; an average theoretical surface area of the toner particle, an amount of the fine particles A, and a coverage ratio of the toner particle surface by the fine particles A satisfy a specific relationship; the amount of the fine particles B is in a specific range; and a proportion F of an area occupied by a part of the fine particles B embedded in a surface vicinity region of the toner in a total area occupied by the fine particles B present in a cross section of one particle of the toner is 50% by area or more.

A toner includes toner particle containing at least a strontium titanate particle on the surface of the toner particle, and the toner is a water-washed toner from which strontium titanate particle desorbable by water washing are removed by water washing. The water-washed toner contains the strontium titanate particle having a number average particle diameter of primary particle (D1) of 10 nm or more and 150 nm or less, and when the distribution of an Sr element in the water-washed toner in the depth direction is determined, (i) the Sr element abundance on the outermost surface x satisfying 0.00<x0.80, and (ii) the difference between x and xp xpx satisfying 0.00<xpx0.95, where xp is the maximum peak value (atomic %) of the Sr element abundance in the region from the outermost surface to 50 nm.

A toner comprising an external additive and a toner particle including a binder resin, a colorant and inorganic fine particles A, wherein the external additive contains an external additive B, a number average particle diameter of primary particles of the external additive B is 30 to 200 nm, an adhesion index of the external additive B to the toner particle is 0.00 to 3.00, a number average particle diameter of primary particles of the inorganic fine particles A is greater than that of the external additive B, and in SEM observations of the toner under specific condition, the number of particles (Na) of the external additive B in a 2 m square region of the toner surface and the number of particles (Nb) of the external additive B observed in a state of overlapping with the inorganic fine particles A in the region satisfy Nb/Na of 0.20 or more.

An image forming apparatus in which occurrence of an image failure in association with contamination caused by an external additive, such as silica, adhering to a charging unit is suppressed. The image forming apparatus is configured to charge an image bearing member through use of the charging unit, and uses toner having, on a surface thereof, strontium titanate particles and silica particles having predetermined physical properties.

A polymeric composition including a copolymer comprising a first monomer having a high carbon to oxygen ratio of from about 3 to about 8; a second monomer comprising two or more vinyl groups, wherein the second monomer is present in the copolymer in an amount of from greater than about 8 percent by weight to about 60 percent by weight, based on the weight of the copolymer; and, optionally, a third monomer comprising an amine, wherein the third monomer, if present, is present in an amount of from about 0.5 percent by weight to about 5 percent by weight, based on the weight of the copolymer. A toner including the copolymer as a toner surface additive. An emulsion aggregation toner process including the copolymer as a toner surface additive.

Provided is a toner including a binder resin, and a charge-controlling agent, wherein a volume average particle diameter X of the toner after a stress treatment satisfies Formula (1), and an amount Y of fine toner particles having particle diameters of 3 micrometers or smaller and circularity of 0.70 or less satisfies Formula (2).

A toner comprising a toner particle that contains a binder resin and fine particles A at the surface of the toner particle, wherein the fine particles A are organosilicon polymer fine particles, the organosilicon polymer fine particles have a number-average primary particle diameter of 30 nm to 500 nm, the organosilicon polymer fine particles have an attachment index for a polycarbonate film of not more than 3.5, the organosilicon polymer fine particles penetrate into the toner particle in a penetration depth b (nm), and protrude from the toner particle in a protrusion height c (nm), and b and c satisfy 0.05b/(b+c)0.40.

A toner comprising an external additive and a toner particle including a binder resin, a colorant and inorganic fine particles A, wherein the external additive contains an external additive B, a number average particle diameter of primary particles of the external additive B is 30 to 200 nm, an adhesion index of the external additive B to the toner particle is 0.00 to 3.00, a number average particle diameter of primary particles of the inorganic fine particles A is greater than that of the external additive B, and in SEM observations of the toner under specific condition, the number of particles (Na) of the external additive B in a 2 m square region of the toner surface and the number of particles (Nb) of the external additive B observed in a state of overlapping with the inorganic fine particles A in the region satisfy Nb/Na of 0.20 or more.