A toner is provided, which has a toner particle containing a binder resin including a first resin and a second resin, wherein the first resin is a crystalline resin, the second resin is an amorphous resin, the first resin contains a specific amount of a first monomer unit having a specific structure, an acid value of the first resin and an acid value of the second resin are 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, the toner particle contains a multivalent metal element, the multivalent metal element is at least one metal element selected from the group consisting of Mg, Ca, Al, Fe and Zn, and a total content of the multivalent metal element is within a specific range.

A toner having: a toner particle containing a binder resin including a first resin and a second resin; and an inorganic fine particle on a surface of the toner particle, wherein the first resin has a specific content ratio of a specific monomer unit, acid values of the first unit and second unit are within specific ranges, a domain matrix structure including a matrix containing the first resin and domains containing the second resin appears in cross-sectional observation of the toner, a compound having an alkyl group is present on a surface of the inorganic fine particle, and a volume resistivity of the inorganic fine particle is 1.0×10.sup.5 Ω.Math.cm to 1.0×10.sup.13 Ω.Math.cm.

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 40 percent by weight, based on the weight of the copolymer; and optionally, a third monomer comprising an amine, wherein the third monomer is present in an amount of from about 0.1 percent by weight to about 1.5 percent by weight, based on the weight of the copolymer; and a surfactant, wherein the surfactant has a minimum surface tension at critical micelle concentration of less than about 30 mN/m. A toner including the copolymer as a toner surface additive. An emulsion aggregation toner process including the copolymer as a toner surface additive.

Metal-oxide composite particles are used as a toner additive.

Provided are toners and combinations of toners that demonstrate excellent color and are Ames test negative in both Salmonella typhimurium strains TA98 and TA100.

A toner for electrophotography includes a toner particle including a binder resin, a colorant, and a releasing agent, and an additive material including a quantum dot-inorganic particle composite. The additive material is attached to an external surface of the toner particle. The quantum dot-inorganic particle composite includes quantum dot particles and inorganic particles present between the quantum dot particles.

A positively charged toner for development of an electrostatic image, containing matrix particles containing at least a binder resin and a release agent, coated with inorganic fine particles, the binder resin containing a crystalline resin, the release agent containing ester wax (W) containing a dipentaerythritol unit as a constitutional component, the inorganic fine particles containing positively charged silica (S1) and negatively charged silica (S2), and the positively charged silica (S1) having an average particle diameter that is smaller than an average particle diameter of the negatively charged silica (S2), and the negatively charged silica (S2) having an average particle diameter of 10 nm or more and 90 nm or less.

Provided is, for example, a compound excellent in light fastness and storage stability. The compound is characterized by having a structure represented by the following formula (1) or (2). ##STR00001##

A white toner comprising a toner particle including a binder resin, an inorganic white pigment, and a polyvalent metal salt compound, wherein the inorganic white pigment has an acidic group at a surface thereof; an amount of the inorganic white pigment in the toner particle is 10% to 50% by volume; the polyvalent metal salt compound is a specific compound; an absolute value of the difference between an SP value (J/cm.sup.3).sup.1/2 of the binder resin and that of the polyvalent metal salt compound is 0.0 to 6.0; and an amount of the polyvalent metal salt compound, an amount of a polyvalent metal, the amount of the inorganic white pigment, and an amount of the acidic group at a surface of the inorganic white pigment satisfy a specific relationship.

A developing device includes a developer container, a developing roller, and a doctor member. The developer container contains a developer including a toner and a developer. The developing roller includes a developing sleeve bearing the developer, a magnet roller in the developing sleeve. The doctor member includes a regulating portion regulating an amount of the developer home on the developing sleeve to be a predetermined amount. The regulating portion is disposed with a first distance from the developing sleeve. The developing sleeve is disposed with a second distance from an image hearer, and when the developing sleeve bearing the predetermined amount of developer passes a vicinity of the image bearer, a value obtained by dividing the predetermined amount by the second distance is less than a threshold of occurrence of adherence of the developer to the developing sleeve.