Toner contains a binder resin, a releasing agent, and a tri- or higher metal salt, wherein the toner has a weight average molecular weight (Mw) of from 7,000 to 10,000, a ratio of the weight average molecular weight (Mw) to a number average molecular weight (Mn) of 5 or less, and an acid value of from 6 mgKOH/g to 12 mgKOH/g, wherein the binder resin is a polyester resin, wherein the releasing agent is a monoester wax.

The positively-chargeable black toner includes colored resin particles containing a binder resin, carbon black and, as a charge control resin, a quaternary ammonium salt group-containing copolymer, wherein the quaternary ammonium salt group-containing copolymer is a styrene acrylic polymer containing a quaternary ammonium salt group-containing (meth)acrylate monomer unit; wherein a copolymerization ratio of the quaternary ammonium salt group-containing (meth)acrylate monomer in the quaternary ammonium salt group-containing copolymer, is in a range of from 0.1% by mass to 2.5% by mass. A content of the carbon black is in a range of from 10 parts by mass to 15 parts by mass with respect to 100 parts by mass of the binder resin. A blow-off charge amount of the colored resin particles measured by a specific charge amount measuring method, is in a range of from 5 C/g to 60 C/g.

A liquid electrophotographic composition is described, which comprises a carrier liquid, a polymer resin comprising a copolymer of an alkylene monomer and a monomer selected from acrylic acid and methacrylic acid, and at least 5 wt. % of an optical brightening agent based on the total solids content of the composition.

A liquid electrophotographic composition is described, which comprises a carrier liquid, a polymer resin comprising a copolymer of an alkylene monomer and a monomer selected from acrylic acid and methacrylic acid, and at least 5 wt. % of an optical brightening agent based on the total solids content of the composition.

A toner comprising a coloring agent, an amorphous polyester, a crystalline polyester, ester wax comprising of multiple ester compounds, each having a carbon number selected from 32 to 54 and, hydrophobic silica having an average primary particle diameter of 8 to 35 nm, wherein when the ion intensity ratio of each ester compound having a different carbon number is expressed as percentage, the content (a) of the ester compound having a carbon number of (Cn) showing the maximum intensity ratio is from 20 to 55% by weight of the entire ester wax, and the sum (d) of the content (b) of the ester compound having a carbon number of (Cn4) and the content (c) of the ester compound having a carbon number of (Cn2) satisfies the following formula: 0.619d/a0.783.

Provided is a toner external additive including: a strontium titanate particle which has a hydrophobized surface, in which an average primary particle diameter is 10 nm or more and 100 nm or less, and a specific volume resistivity R1 is 11 or more and 14 or less in terms of a common logarithm value log R1.

An electrostatic charge image developing toner includes: a toner particle having average circularity of 0.91 or more and 0.98 or less, a silica particle externally added to the toner particle, and a strontium titanate particle that is externally added to the toner particle, that has an average primary particle diameter of 10 nm or more and 100 nm or less, that has average primary particle circularity of 0.82 or more and 0.94 or less, and circularity that becomes 84% of accumulation of the primary particle of more than 0.92.

An electrostatic charge image developing toner includes: a toner particle that contains a releasing agent, that has an exposed portion in which the releasing agent is exposed on a surface, and in which a proportion of the exposed portion occupying a surface, which is obtained by X-ray photoelectron spectroscopic analysis is 1 atom % or more and 20 atom % or less; and a strontium titanate particle that is externally added to the toner particle, that is doped with a metal element other than titanium and strontium, and in which an average primary particle diameter is 10 nm or more and 100 nm or less.

An image forming apparatus for developing an image with developer includes a development part, a transfer part, and a fuser the medium. The developer is configured with a plurality of particles, an average circularity degree of the developer is ranged within 0.955 to 0.970, and a peeling rate (%) of the external additive by a following equation is 30.6% or less,
peeling rate (%)=[1(X/Y)]100(1) wherein X is an amount (weight %) of the external additive included in the developer after ultrasonic waves are applied, and Y is an amount (weight %) of the external additive included in the developer before the ultrasonic waves are applied.

An image forming apparatus for developing an image with developer includes a development part, a transfer part, and a fuser the medium. The developer is configured with a plurality of particles, an average circularity degree of the developer is ranged within 0.955 to 0.970, and a peeling rate (%) of the external additive by a following equation is 30.6% or less,
peeling rate (%)=[1(X/Y)]100(1) wherein X is an amount (weight %) of the external additive included in the developer after ultrasonic waves are applied, and Y is an amount (weight %) of the external additive included in the developer before the ultrasonic waves are applied.