Abstract: The present invention is an electrostatographic toner that includes an organometallic complex of dimethyl sulfoxide with a metal salt as a charge control agent having the structure; (M+n)x ((CH3)2SO2)y (A?q)z where n, q, x and z are integers between 1 and 6, and y is an integer between 2 and 12, The present invention also includes a developer having a toner, an organometallic complex of dimethyl sulfoxide with a metal salt as a charge control agent having the structure; (M+n)x ((CH3)2SO2)y (A?q)z where n, q, x and z are integers between 1 and 6, and y is an integer between 2 and 12, and a carrier particle.

Abstract: An image forming method comprising steps of forming a toner image by developing by a toner a latent image on a photoreceptor comprised of a layer formed on a substrate, transferring the toner image onto a recording medium on which the toner image is recorded and fixing, wherein the average circular degree of the toner is not less than 0.94, and the toner contains a wax comprising an ester of a carboxylic acid having carbon atoms of not less than 16 or an ester of an alcohol having carbon atoms of not less than 16, and the layer is a layer to be contacted to the toner in the developing step and contains an inorganic fine particles having a number average of primary particle diameter of approximately not less than 1 nm and less than 100 nm.

Abstract: To a toner used in an image forming apparatus is added an external additive whose main components are oxide fine particles in which dimethylsilyl groups are introduced to surfaces thereof, and whose volatilizing amount of octamethylcyclotetrasiloxane in a first volatilizing test is 0.2 ?g or less. Consequently, it is possible to prevent foreign matters from attaching to a discharging electrode included in the image forming apparatus. The first volatilizing test is performed in such a manner that 2 g of the external additive is put in a sealing container and the inside of the sealing container is kept at 120° C. for 10 minutes so that octamethylcyclotetrasiloxane volatilizes from the external additive.

Abstract: The charge control agent comprises aggregate particles including an azo-type iron complex salt represented by the following chemical formula [VI] (in the chemical formula [VI], B+ is (H+)x(Na+) 1?x and x is mole ratio and 0.6 to 0.9, or B+ is (H+)y(Na+)1?y and y is mole ratio and 0 to 0.2) and the aggregate particles have 0.5 to 5.0 microns of an average particle size. A toner for developing an electrostatic image comprises a resin for the toner and the charge control agent. An image formation process of electrophotography comprises a step for developing an electrostatic latent image on an electrostatic latent image frame by a developer including the toner.

Abstract: To provide a toner and an image forming apparatus using the toner, the toner contains an external additive that can suppress adherence of impurities to a discharge electrode of a corona discharger and prevent occurrence of charging unevenness. The external toner additive is comprised of a particulate metal oxide with trimethylsilyl groups introduced on the surface thereof, the volatile amount of trimethylsilanol being specified to be 0.25 ?g or below based on a method for quantitative analysis of trimethylsilanol in the external additive. The toner of the present invention is specified such that the volatile amount of trimethylsilanol is specified to be 0.02 ?g or below based on a method for quantitative analysis of trimethylsilanol in the toner.

Abstract: A toner is disclosed, for developing electrostatic images by means of image forming apparatuses, that comprises toner particles, and an external additive, wherein the toner particles comprise a binder resin and a colorant, the external additive is introduced onto the surface of the toner particles, the external additive liberates from the surface of the toner particles in a rate of 7% to 50% under the condition that the toner is dispersed within a surfactant-containing electrolyte at 20 W output power and 20 kHz frequency for one minute by means of an ultrasonic homogenizer.

Abstract: A toner including a binder resin comprising a polyester resin in an amount of from 50 to 100% by weight, wherein the polyester resin includes an unsaturated polyester resin which is preferably a crystalline polyester resin; a colorant; and a fatty acid metal salt which is preferably microencapsulated. A method for preparing a toner including forming particles of a toner composition including at least a binder resin including a polyester resin in an amount of from 50 to 100% by weight and a colorant, in an aqueous medium to prepare a dispersion of a particulate material, wherein the polyester resin includes an unsaturated polyester resin; drying the particulate material; and mixing a fatty acid metal salt with the particulate material to subject double bonds of the unsaturated polyester resin to oxidation polymerization.

Abstract: A toner that is excellent in low-temperature fixing property, offset resistance, storage stability, charge rising property, charge stability with time and pulverizability and allows for forming high-quality images over a long period of time. The toner contains at least a binder resin, a colorant and a charge controlling agent, wherein the charge controlling agent contains an aromatic oxycarboxylic acid metal compound having a trivalent or more central metal, the binder resin comprises a polyester resin (A) having a softening point Tm (A) of 120° C. to 160° C. and a polyester resin (B) having a softening point Tm (B) of 80° C. to less than 120° C., and at least any one of the polyester resins (A) and (B) contains 1,2-propane diol at 65 mol % or more in a divalent alcohol component and can be obtained by condensation polymerizing an alcohol component substantially composed of only an aliphatic alcohol with a carboxylic acid component.

Abstract: Discussed herein are a charge control agent and toner comprising said charge control agent. Said toner of the invention is comprised of a resin, a colorant, and the charge control agent, wherein, said charge control agent is comprised of a specific type of metal complexes. In the invention, the charge control agent has excellent charge control properties and the characteristics of uniform crystalline size, high charge speed, high thermo stability, low moisture absorption, and good compatibility with resin. The toner of the invention has excellent electrical characteristics and produces stable image of high quality under a wide range of environmental conditions without dusting and fogging.

Abstract: Toner compositions of toner particles including additive particles upon an external surface of the toner particles, wherein the additive particles include crosslinked styrene containing polymer particles, exhibit reduced sensitivity to relative humidity. The crosslinked styrene containing polymer particles have an average particle size of from about 30 nm to about 300 nm, and may include styrene homopolymer particles, styrene copolymer particles or mixtures thereof. A process of reducing the relative humidity sensitivity of toner using such external surface additive is also described.

Abstract: The present invention provides an organic silicone fine particle for latent electrostatic image developing toners, wherein the organic silicone fine particle has a volume average particle diameter of 0.05 ?m to 6.0 ?m which is obtained by measurement based on Coulter principle, and has a hemispherical polysiloxane cross-linked structure. By mixing an appropriate amount of an organic silicone resin particle formed in a deformed shape (a hemispherical shape) in a toner or developer, the present invention prevents movement of the organic silicone resin particle from surface functional sites, the movement caused by a phenomenon such as detachment thereof from a toner surface or rolling movement on the toner surface, by the effect of its shape, and makes it possible to effectively achieve the expected function.

Abstract: A toner including a binder resin, a colorant, and a silicon-containing polymer, which is manufactured by a method including: discharging a toner constituent liquid including toner constituents including the binder resin, the colorant, and the silicon-containing polymer, from at least one discharge opening to form liquid droplets thereof; and converting the liquid droplets into solid toner particles in a granulation space.

Abstract: Provided is a magnetic toner comprising magnetic toner particles each comprising at least a binder resin and a magnetic iron oxide, the magnetic toner being excellent in developability and environmental stability, and being capable of reducing a toner consumption. A saturation magnetization ?s and a remanent magnetization ?r of the magnetic toner in a measured magnetic field of 795.8 kA/m are arranged in the range of 5 to 60 Am2/kg and in the range of 0.1 to 10.0 Am2/kg, respectively, and the binder resin having a polyester component polymerized by using a Ti chelate compound as a catalyst is used.

Abstract: Hydrophobic inorganic fine particles characterized by being a mixture of at least small-particle-diameter inorganic fine particles having an average primary particle diameter of 5 to 25 nm and having a maximum peak particle diameter of 20 nm or less and large-particle-diameter inorganic fine particles having an average primary particle diameter which is 1.5 to 100 times the average primary particle diameter of the small-particle-diameter inorganic fine particles; the mixture being a mixture having been treated in the same treating tank to subject both the small-particle-diameter inorganic fine particles and large-particle-diameter inorganic fine particles simultaneously to hydrophobic treatment.

Abstract: A toner for electrostatic latent image development containing at least a binder resin and a colorant, wherein [Fe]/[C] satisfies the following formula (1) where [C] indicates the carbon content (%) and [Fe] indicates the iron content (%) of the toner determined through X-ray fluorescence analysis, 0.00005?[Fe]/[C]?0.0002.

Abstract: Disclosed is a toner containing resin mother particles and oil, in which the volume-average particle diameter of the resin mother particles is not less than 2 ?m but less than 4 ?m, (volume-average particle diameter of the resin mother particles)/(number-average particle diameter of the resin mother particles) is more than 1 but less than 1.1, the oil is silicone oil or fluorine oil, and the content of the silicone oil or fluorine oil is not less than 0.05% by mass but less than 2% by mass relative to the resin mother particles.

Abstract: The present invention provides a negatively chargeable spherical toner having: a toner mother particle having a binder resin and a colorant, which has: a number average particle size of from 4.5 to 9 ?m; a particle size distribution that has an integrated value of particle sizes of 3 ?m or less of 1% or less; and an average sphericity of from 0.95 to 0.99; and an alumina fine particle externally added to the toner mother particle, which has a number average particle size of from 0.1 to 1.0 ?m, wherein a work function (?t) of the toner mother particle is larger than a work function (?A) of the alumina fine particle by at least 0.4 eV.

Abstract: The present invention provides An image forming apparatus having: a negatively chargeable spherical toner; an latent image carrier; a charging member for charging a surface of the latent image carrier uniformly without contacting the latent image carrier; an electrostatic latent image forming member for forming an electrostatic latent image on the surface of the latent image carrier; a developing member for developing the electrostatic latent image, without contacting the latent image carrier, by using the negatively chargeable spherical toner so as to form a toner image on the latent image carrier; and an intermediate transfer medium to which the toner image is transferred, wherein the negatively chargeable spherical toner haves: a toner mother particle having a binder resin and a colorant; and a hydrophobic alumina particle as an external additive, wherein the hydrophobic alumina particle has a work function (?A1) larger than a work function (?TM) of a surface of the intermediate transfer medium.

Abstract: A pigment preparation comprising at least one copper phthalocyanine pigment from the group of C.I. Pigment Blue 15, 15:0, 15:1,15:2, 15:3, 15:4, and 15:6, and at least one pigment dispersant of the formula (I), in which n is a number 1, 2, 3 or 4.

Abstract: A method for preparing a functional particulate organic material, including providing a suspension of a particulate organic material having an acid group on a surface thereof; reacting a metal cation with tri- or more-valence with the acid group; and reacting at least one of an organic acid and an organic acid salt with the metal cation. A toner prepared by the method mentioned above. An image forming method including developing a latent image with the toner; transferring the toner image on a receiving material optionally via an intermediate transfer medium, and fixing the toner image on the receiving material. A process cartridge including a developer container containing a developer including the toner mentioned above, and at least one of an image bearing member; a charger; a developing device; and a cleaner.

Abstract: A toner is formed of toner particles including a polyester resin as a principal component, and at least a colorant and a charge control agent, and externally added inorganic fine particles and organic fine particles. The toner has a volume-average diameter of 4 to 10 ?m, contains the charge control agent at 0.1 to 1.5%, and has an acid value of 2 to 33 mgKOH/g. The charge control agent exhibits a number-basis isolation percentage of at most 10% with respect to the toner particle. The charge control agent, the inorganic fine particles and organic fine particles exhibit number-basis isolation percentages from the toner particles satisfying a following relationship: 30%>inorganic fine particles>organic fine particles>charge control agent>0%.

Abstract: A toner composition includes a binder, a colorant, and a surface additive package including a polydimethylsiloxane surface treated silica, a surface treated titania, and calcium sterate. The toner composition provides improved triboelectric charging properties.

Abstract: Dry electrographic toner compositions are provided comprising a plurality of dry toner particles, wherein the toner particles comprise polymeric binder comprising at least one amphipathic copolymer comprising one or more S material portions and one or more D material portions. The dry electrographic toner composition comprises a wax associated with the dry toner particles, wherein substantially all of the wax is associated with the toner particle at the surface thereof. Methods of making electrographic toner compositions are also provided comprising preparing polymeric binder particles comprising at least one amphipathic copolymer comprising one or more S material portions and one or more D material portions, preparing toner particles, drying the toner particles, and milling the dry toner particles in the presence of a wax component to provide a dry toner particle composition having the wax associated with the toner particles.

Abstract: The invention provides metal oxide particles surface-treated with at least one alkoxysilane compound, methods of making such, and toners comprising same.

Abstract: A toner having a core with at least one resin and at least one colorant, and having on a surface thereof, an additive package including fluorinated polymer particles, and a method of forming toner particles having surface particles attached thereto, wherein the surface particles include fluorinated polymer particles, and the method includes aggregating a material with at least one resin and at least one colorant to produce toner particles, following aggregation, forming a mixture of the surface particles and the toner particles, and subjecting the mixture to a temperature above the glass transition temperature of the toner particles to coalesce the toner particles, whereby the surface particles become at least partially embedded within the surface of the toner particles.

Abstract: A toner includes particles of a resin, an optional colorant, a first wax and a second wax, where the toner particles are prepared by an emulsion aggregation process. Additional waxes can also be added for different properties.

Abstract: A magenta toner is provided which contains at least a binder resin, a colorant, and a wax, in which a maximum heat-absorption peak temperature as measured using a differential scanning calorimeter, a reflectance at a predetermined wavelength when measured in a powder state by spectroscopic analysis, and lightness when measured in a powder form are in specific ranges. A full-color image is formed using the magenta toner as a pale magenta toner in combination with a deep magenta toner. According to the present invention, it becomes possible to form a vivid image which has reduced graininess and roughness from a low-density region to a high-density region, ensures a sufficient fixing temperature region, has a color reproduction range wider that the conventional one, and has high transparency on an OHP sheet.

Abstract: Dry electrographic toner compositions are provided comprising a plurality of dry toner particles, wherein the toner particles comprise polymeric binder comprising at least one amphipathic copolymer comprising one or more S material portions and one or more D material portions. The dry electrographic toner composition comprises a wax associated with the dry toner particles that has been entrained in the toner particle during the formation of the amphipathic copolymer. Methods of making the electrographic toner compositions are also provided. These toner compositions provide images having excellent durability and erasure resistance properties at low fusion temperatures and with little undesired offset.

Abstract: A toner is disclosed. The toner comprises a vinyl resin, a colorant, and a compound represented by a formula of Compound 1, Compound 2 ion or Compound 3.

Abstract: Toners and developers are disclosed. The toner of the present invention contains at least one toner resin, at least one charge control agent, at least one surface treatment agent, and optionally at least one release agent and/or colorant. The toners of the present invention have excellent triboelectric stability over a wide range of temperatures and relative humidity environmental conditions. Further, the toners of the present invention have excellent charge to mass stability over long periods of time. Development systems and methods for developing electrostatic images with toner are further disclosed.

Abstract: The invention relates to a developer for developing electrostatic images. The developer includes magnetic carrier particles at a loading of from 60 to 99 weight percent of the developer. Toner particles are at a loading of 1 to 40 weight percent of the developer. The toner particles include a resin core particle having an outer surface and 0.05 to 5 weight percent a first metal oxide powder is substantially fixed to the outer surface. The toner particles further include 0.05 to 2 weight percent of a second metal oxide powder that is substantially free to transfer between outer surface of the toner particles and an outer surface of the magnetic carrier surface.

Abstract: A toner having at least one binder, at least one colorant and external additives. The external additives include at least one of silica and titania, and at least two metal stearates. A developer may be produced including the toner having at least two metal stearates and a carrier. An electrophotographic machine includes the toner with two metal stearates.

Abstract: The present invention relates to a non-magnetic mono-component toner comprising a toner mother particle, and a coating layer formed on the mother particle where the coating layer comprises fatty acid metal salt having average particle size of 0.05 to 3.0 ?m, a first organic particle having average particle size of 0.3 to 2.0 ?m, a second organic particle having average particle size of 0.05 to 0.25 ?m, and silica having average particle size of 0.006 to 0.04 ?m. The color toner has narrow charge distribution, high chargeability, a low environmental dependence, and excellent image quality, transfer efficiency, and long-term stability by significantly reducing the contamination of the charging elements.

Abstract: Dry electrographic toner compositions are provided comprising a plurality of dry toner particles, wherein the toner particles comprise polymeric binder comprising at least one amphipathic copolymer comprising one or more S material portions and one or more D material portions. The dry electrographic toner composition comprises a wax associated with the dry toner particles, wherein a substantial portion of the wax is entrained in the toner particle and a substantial portion of the wax is associated with the toner particle at the surface thereof. Methods of making electrographic toner compositions are also provided comprising preparing polymeric binder particles comprising at least one amphipathic copolymer comprising one or more S material portions and one or more D material portions, and milling the particles before or after formulation as toner particles with wax in the liquid carrier prior to drying to form the dry toner composition.

Abstract: A toner comprising a resin and having on a surface thereof, an additive package comprising coated strontium titanate.

Abstract: An electrostatic image developing toner is disclosed. The toner contains an external additive, which contains inorganic minute particles having a number average primary particle diameter of 5-30 nm and a titanic acid compound treated by silicone oil or a coupling agent.

Abstract: A toner contains: (A) a binder resin; (B) a colorant; (C) a charge controlling agent; and (D) an additive. (A) contains: a polyester resin containing no tetrahydrofuran-insoluble component; and having components having a molecular weight not greater than 5×102 present in an amount of 4% or less by weight, a main peak present in a molecular weight range of from 3×103 to 9×103 as determined by gel permeation chromatography. (C) contains: a metal salt of salicylic acid or salicylic acid derivative. (D) contains: a hydrophobized silica having a primary particle diameter of from 0.01 to 0.03 ?m; and a hydrophobized titanium oxide having a primary particle diameter of from 0.01 to 0.03 ?m, a specific surface area of from 60 to 140 m2/g, one or more water-soluble components in an amount of 0.2% or more by weight, a transmittance not less than 35% for light having a wavelength of 300 nm and a transmittance not less than 80% for light having a wavelength of 600 nm.

Abstract: A toner composition comprising a binder, colorant, and a charge control surface additive mixture comprising a mixture of a first titanium dioxide possessing a first conductivity and a second titanium dioxide possessing a second conductivity and which second conductivity is dissimilar than the first conductivity; wherein the mixture of the first titanium dioxide and the second titanium dioxide is selected in a ratio sufficient to impart a selected triboelectric charging characteristic to the toner composition.

Abstract: An electrophotographic toner is disclosed. The toner is composed of a dye chelatable with a metal represented by the formula (1) and a copper compound represented by the formula (2) and a thermoplastic resin: In the formula, R1, R2, R3, and R4 each represents a hydrogen atom or a substituent. Z1 represents a 5 or 6-membered heterocyclic ring containing at least one nitrogen atom, which heterocyclic ring may have a substituent or form a condensed ring. Z2 represents a 5 or 6-membered heterocyclic ring which heterocyclic ring may have a substituent or form a condensed ring. Cu2+(X1)m(X2)n.W1 ??formula (2) wherein X1 and X2 are each a monodentate or didentate ligand, provided that X1 and X2 may link with each other which may be the same or different from each other; n and m are each an integer of 0 to 2; W1 is a counter ion when a counter ion is required for neutralization of charge.

Abstract: A toner composition including a binder, a colorant, and a surface additive package including a surface treated silica, a surface treated titania, and magnesium stearate.

Abstract: A positive electrified charge control agent comprising a silicon complex compound of an effective component represented by the following chemical formula (I) and/or chemical formula (II) (in the formula (I) and formula (II), [D-(SO3)2]2? is a bivalent anion of an organic acid having at least two sulfonic acid groups, p is 0 or 1, B is a bonding line when p is 0, B is a carbon atom or a nitrogen atom when p is 1, J is a carbon atom or a nitrogen atom, A is an organic group which forms a ring with (B)p and J, both of R are same or different to each other and are an organic group, and these both of R are independent or form a heterocyclic ring). A positive electrified toner for developing an electrostatic image comprises the positive electrified charge control agent. A charge control method of the positive electrified toner for developing the electrostatic image comprises a step for making the toner positively electrified by friction.

Abstract: A method of forming toner particles having surface particles attached thereto includes the steps of aggregating a material of at least one binder material and at least one colorant to produce toner particles, following aggregation, forming a mixture of the surface particles and the toner particles, and subjecting the mixture to a temperature above the glass transition temperature of the toner particles to coalesce the toner particles, whereby the surface particles become at least partially embedded within the surface of the toner particles. Toner particles prepared by such method include a core comprised of at least one binder and at least one colorant, and surface particles at an external surface of the toner particles, wherein at least about 50% of the surface particles are substantially completely covered by a portion of binder and a majority of the surface particles protrude from the toner particle surface a distance of at least 50% of the average particle size of the surface particles.

Abstract: An electrophotographic toner is disclosed. The toner is composed of toner particles comprising colored particles containing a dye which is dispersed in a binder resin, wherein the toner particles satisfies formula of 3?D2/D1>1, D1 being a volume average particle diameter of the colored particles, and D2 being an average diameter of dye cloud formed by the colored particles in the toner particle.

Abstract: To provide a toner for developing an electrostatic charge image, which has a good low temperature fixing property whereby it is useful for an image-forming device of a low temperature heat fixing system using a heat roll having a surface temperature of at most 150° C. and it does not fuse to a blade or a toner transport roller, and which is excellent in durability with little change in the image quality in a continuous copying operation. A toner for developing an electrostatic charge image, having base toner particles comprising at least a binder resin and a coloring agent, wherein the base toner particles contain an oil having a surface tension of at most 30 mN/m at 25° C., and the toner has a softening point of at most 100° C.

Abstract: An image forming method comprises: fixing an image formed by a toner on a record sheet in a nip member formed by a pressurizing member which is compressibly contacted against a heating fixing rotor having an elastic body layer formed on an endless periphery surface capable of orbitally moving and which creates locally a large distortion occurred in the elastic body layer in vicinity of outlet thereof, wherein the toner includes at least two metal salts having different valence and has a relationship given by the Formula (1). 2.0?a?0.1 1.0?b?0.01 7.5?a/b?1.1 ??Formula (1) wherein a (mass %) is defined as a content of a metal salt which is contained at a highest content in total toner mass and b (mass %) is defined as a content of a metal salt which is contained at a second-highest content in the total toner mass, and mass values of a and b represent anhydride reduced values.

Abstract: Hydrophobic inorganic fine particles characterized by being a mixture of at least small-particle-diameter inorganic fine particles having an average primary particle diameter of 5 to 25 nm and having a maximum peak particle diameter of 20 nm or less and large-particle-diameter inorganic fine particles having an average primary particle diameter which is 1.5 to 100 times the average primary particle diameter of the small-particle-diameter inorganic fine particles; the mixture being a mixture having been treated in the same treating tank to subject both the small-particle-diameter inorganic fine particles and large-particle-diameter inorganic fine particles simultaneously to hydrophobic treatment.

Abstract: A method for forming a full color image including: forming at least yellow, magenta and cyan color toner images on a receiving material to form a full color image thereon; and fixing the full color image upon application of heat thereto while not contacting the full color image, wherein each of the yellow, magenta and cyan color toner images includes a binder resin and a pigment, wherein the yellow color toner includes a benzimidazolone pigment, the magenta color toner includes at least one of Naphthol Carmine F6B and a combination of Naphthol Carmine F6B and Naphthol Carmine FBB, and the cyan color toner includes ? copper phthalocyanine, and wherein the yellow color toner image has a position closer to the receiving material than any other color toner image when two or more of the color toner images including the yellow color toner image are overlaid.

Abstract: A toner for electrophotography contains a binder resin, a charge control agent, and a colorant. The colorant is a black iron oxide compound containing 10 to 45% by weight of titanium component calculated in terms of Ti atom in relation to Fe atom when measured by wavelength dispersive X-ray fluorescence spectrometry. Peaks at Bragg angle 2? of the toner to CuK? X-ray are peak A at 32.9 degrees ±0.3 degrees and peak B at 35.5 degrees ±0.3 degrees, and X ray intensity ratio between peaks A and B (A/B) is in the range of 0.3 to 2.0 at a scan speed of 0.5 to 4 degrees/min.

Abstract: A toner for image formation is provided, which is produced by dispersing in an aqueous solvent a toner composition which includes a composition thermally soluble in an organic solvent and a coloring agent, thereby forming toner particles, wherein the thermally soluble composition includes (a) a polyester having an acid value and (b) a metal alcolate and/a metal chelate compound. The toner is capable of attaining image fixing at a sufficiently low image fixing temperature and a sufficiently broad image fixing temperature range for use in practice. Furthermore, toner containers such as a toner cartridge and a process cartridge are provided, which are loaded with the toner. Such toner containers can be detachably mounted on an image forming apparatus.

Abstract: The present invention relates to an image forming method including: a charging step; an electrostatic latent image forming step; a developing step; a transfer step; a fixing step; and a cleaning step, wherein an electrostatic latent image developing agent comprises a toner and a carrier, wherein particles which have a volume resistivity of at least 1×1014 ?cm and an average primary particle diameter of 50 nm or less has a higher covering ratio than other particles on the toner particle surfaces, a shape factor SF1 of the toner is in the range of from 100 to 140, the carrier is a resin coated carrier, and at least a coating resin layer comprises a positively charging resin and a quaternary ammonium salt compound.