Abstract: A toner is provided. The toner comprises colored particles and external additives present on surfaces of the colored particles. The colored particles each comprise a core and a shell layer. The core contains a crystalline resin, a non-crystalline resin, and a colorant. The shell layer contains a resin and has a thickness of from 30 to 130 nm. The external additives comprise a metal oxide and a silicon compound. An electronegativity X(A) of the metal oxide and an electronegativity X(Si) of the silicon compound satisfy a relation 0.5?X(A)/X(Si)?0.8. A proportion of an amount of the metal oxide directly adhered to the surfaces of the colored particles to a total amount of the metal oxide present on the colored particles is from 60% to 90% by mass.

Abstract: Resin particles that can exhibit high degree of coloring and have high charge stability are provided. Resin particles include a base particle including a binder resin and a pigment having an isoindoline skeleton, wherein a longitudinal diameter of the base particle is L, an overlapped area where the cross-section of the base particle overlaps with a passage of circle C when a center of the circle C with a radius (L/10) moves along a contour of the cross-section of the base particle is defined as a surface layer of the resin particle, wherein the pigment having isoindoline skeleton present on the surface layer of the base particle relative to an entire pigment having isoindoline skeleton present on the cross-section of the base particle in a cross-sectional image of the resin particle is less than 30%, and wherein a gel fraction of the base particle is 20% by mass or more.

Abstract: Resin particles include a binder resin in each of the resin particles. The binder resin includes a biomass-derived resin, and polyethylene terephthalate or polybutylene terephthalate. An amount A of a biomass-derived component of the biomass-derived resin and an amount B of the polyethylene terephthalate or the polybutylene terephthalate satisfy A>B. Each of the resin particles has a core-shell structure including a shell layer and a core layer. An average thickness of the shell layer is from 100 nm to 500 nm.

Abstract: The present disclosure provides a resin particle including a binder resin, in which the binder resin contains a biomass-derived resin and a recycled resin, and a content (% by mass) of the biomass-derived resin and a content (% by mass) of the recycled resin in the binder resin satisfy the following relational equation (1): Content of recycled resin >Content of biomass-derived resin.

Abstract: A toner includes a binding resin; and a metal crosslinking agent that forms a metal crosslinking with the binding resin. A measurement curve of a storage elastic modulus G? in a dynamic viscoelasticity measurement has a maximum value in a range of 100° C. or more.

Abstract: An image forming apparatus is provided that includes: an image bearer; a charger; an irradiator; a developing device containing a toner; and a transfer device. The image bearer has a Martens hardness of from 185 to 250 N/m2. The toner satisfies a relation 0.13?X/Dn?0.16, where X [?m] represents an average value of an amount of deformation of the toner by micro-indentation at when a load reaches 3.00×10?4 N at a loading rate of 3.0×10?5 N/sec under an environment of 32 degrees C. and 40% RH, and Dn [?m] represents a number average particle diameter of the toner. The toner contains an external additive comprising silica particles and particles composed mainly of strontium titanate. The particles composed mainly of strontium titanate further contain a third element M selected from the group consisting of La, Mg, Ca, Sn, and Si.

Abstract: A toner including toner particles, each toner particle including a toner base particle, and inorganic particles, wherein the inorganic particles include particles of a fluorine-containing aluminium compound, and a liberation ratio of the inorganic particles is 10% or greater but 60% or less.

Abstract: A toner including toner base particles each including a binder resin and a colorant, and external additive, wherein the toner satisfies conditions (a), (b), and (c) below: (a) storage elastic modulus G?(50) of the toner at 50° C. and storage elastic modulus G?(90) of the toner at 90° C. satisfy Formula (1); G?(50)/G?(90)?6.0×102??Formula (1) (b) a BET specific surface area Bt(m2/g) of the toner and a coverage Ct (%) of the toner base particles covered with the external additive satisfy Formula (2); and Bt?0.03×Ct?1.60??Formula (2) (c) the external additive includes at least cohered particles, the cohered particles are non-spherical secondary particles each formed through cohesion of primary particles, and a number average secondary particle diameter of the cohered particles is 130 nm or greater.

Abstract: A toner is provided. The toner comprises colored particles and external additives present on surfaces of the colored particles. The colored particles each comprise a core and a shell layer. The core contains a crystalline resin, a non-crystalline resin, and a colorant. The shell layer contains a resin and has a thickness of from 30 to 130 nm. The external additives comprise a metal oxide and a silicon compound. An electronegativity X(A) of the metal oxide and an electronegativity X(Si) of the silicon compound satisfy a relation 0.5?X(A)/X(Si)?0.8. A proportion of an amount of the metal oxide directly adhered to the surfaces of the colored particles to a total amount of the metal oxide present on the colored particles is from 60% to 90% by mass.

Abstract: An image forming apparatus is provided that includes: an image bearer; a charger; an irradiator; a developing device containing a toner; and a transfer device. The image bearer has a Martens hardness of from 185 to 250 N/m2. The toner satisfies a relation 0.13?X/Dn?0.16, where X [?m] represents an average value of an amount of deformation of the toner by micro-indentation at when a load reaches 3.00×10?4 N at a loading rate of 3.0×10?5 N/sec under an environment of 32 degrees C. and 40% RH, and Dn [?m] represents a number average particle diameter of the toner. The toner contains an external additive comprising silica particles and particles composed mainly of strontium titanate. The particles composed mainly of strontium titanate further contain a third element M selected from the group consisting of La, Mg, Ca, Sn, and Si.

Abstract: A toner including toner particles, each toner particle including a toner base particle, and inorganic particles, wherein the inorganic particles include particles of a fluorine-containing aluminium compound, and a liberation ratio of the inorganic particles is 10% or greater but 60% or less.

Abstract: A toner including toner base particles each including a binder resin and a colorant, and external additive, wherein the toner satisfies conditions (a), (b), and (c) below: (a) storage elastic modulus G?(50) of the toner at 50° C. and storage elastic modulus G?(90) of the toner at 90° C. satisfy Formula (1); G?(50)/G?(90)?6.0×102??Formula (1) (b) a BET specific surface area Bt(m2/g) of the toner and a coverage Ct (%) of the toner base particles covered with the external additive satisfy Formula (2); and Bt?0.03×Ct?1.60??Formula (2) (c) the external additive includes at least cohered particles, the cohered particles are non-spherical secondary particles each formed through cohesion of primary particles, and a number average secondary particle diameter of the cohered particles is 130 nm or greater.

Abstract: A toner is provided. The toner includes toner particles each including a mother particle and external additive particles covering the mother particle. In a SEM image of the toner, toner particles having a ratio Sd/St of from 5% to 50% are present at a frequency of 15% or more, where Sd representing an area of a largest recessed portion D of each toner particle and St representing whole area of the toner particle, Sd and St determined from the SEM image magnified and binarized to discriminate recessed portions and projected portions of the toner particle from each other. An external additive coverage rate Ca at the largest recessed portion D is from 30% to 100%.

Abstract: A toner is provided. The toner includes toner particles each including a mother particle and external additive particles covering the mother particle. In a SEM image of the toner, toner particles having a ratio Sd/St of from 5% to 50% are present at a frequency of 15% or more, where Sd representing an area of a largest recessed portion D of each toner particle and St representing whole area of the toner particle, Sd and St determined from the SEM image magnified and binarized to discriminate recessed portions and projected portions of the toner particle from each other. An external additive coverage rate Ca at the largest recessed portion D is from 30% to 100%.

Abstract: An image forming method is provided. The method includes the steps of forming an electrostatic latent image on a photoconductor; developing the electrostatic latent image into a toner image with a toner; transferring the toner image onto a recording medium having a smoothness of 20 s or less; and fixing the toner image on the recording medium. The toner exhibits an adhesion force of 100 gf or more, where the adhesion force is the maximum value of a pull force between a layer of the toner and standard paper determined by a tacking test with a probe temperature of 140° C.

Abstract: A toner includes a base particle; and an external additive covering the base particle. The toner includes a tetrahydrofuran (THF)-insoluble component having a glass transition temperature determined from a DSC curve when heated for the second time of from ?50° C. to 10° C. and an average circularity not greater than 0.98, and satisfies the following relation: Bt?0.025×Ct?1.80 wherein Bt represents a BET specific surface area [m2/g]; and Ct represents a coverage [%] of the external additive covering the base particle.

Abstract: A toner includes a base particle comprising a crystalline polyester resin; and an external additive which is a group of silica particles having a number-average particle diameter of from 0.01 ?m to 0.11 ?m on the surface of the toner. A number ratio of the silica particles having a circularity not less than 0.8 is 20% or more in the total number of the silica particles.

Abstract: To provide a toner, which contains silica particles containing first silica particles, and second silica particles, wherein the toner is a toner produced by depositing the silica particles on surfaces of base particles, the first silica particles have an average primary particle diameter of 75 nm to 250 nm, the second silica particles have an average primary particle diameter of 10 nm to 50 nm, a mass ratio of the first silica particles to the base particles is 0.010 to 0.040, a mass ratio of the second silica particles to the base particles is 0.005 to 0.030, a liberation ratio of the silica particles from the toner by a ultrasonic vibration method is 5% by mass to 20% by mass, and an amount of particles having primary particle diameters of 30 nm or smaller in the silica particles librated from the toner by the ultrasonic vibration method is 20% by number or less.

Abstract: A toner includes a base particle; and an external additive covering the base particle. The toner includes a tetrahydrofuran (THF)-insoluble component having a glass transition temperature determined from a DSC curve when heated for the second time of from ?50° C. to 10° C. and an average circularity not greater than 0.98, and satisfies the following relation: Bt?0.025×Ct?1.80 wherein Bt represents a BET specific surface area [m2/g]; and Ct represents a coverage [%] of the external additive covering the base particle.

Abstract: A toner includes a base particle comprising a crystalline polyester resin; and an external additive which is a group of silica particles having a number-average particle diameter of from 0.01 ?m to 0.11 ?m on the surface of the toner. A number ratio of the silica particles having a circularity not less than 0.8 is 20% or more in the total number of the silica particles.