Abstract: An electrostatic latent image developing toner is provided for which if surface area values for 1-butanol, ethylbenzene, n-butyl ether, styrene, butyl propionate, cumene, benzaldehyde and propylbenzene obtained from gas chromatographic analysis of volatile gas components generated upon heating the toner are termed, a, b, c, d, e, f, g and h respectively, then Z1 and Z2 satisfy the formulas shown below. Z1=5.2×10?6a+9.6×10?7b+2.7×10?6c?2.5×10?6d+8.7×10?6e+1.5×10?7f+1.1×10?6g+8.3×10?7h?1.81 Z2=6.9×10?6a+4.6×10?6b?3.9×10?7c+2.5×10?6d?2.1×10?5e+2.3×10?7f?6.8×10?7g+1.2×10?6h?1.82 Z1?0, and Z2?0.

Abstract: In an image forming method having primarily transferring step for transferring to an intermediate transfer member a toner image formed on a photosensitive member, secondarily transferring step for transferring to a transfer material the toner image held on the intermediate transfer member, and, after the secondary transferring step, cleaning step for removing the toner remaining on the intermediate transfer member by bringing a cleaning means into contact with the intermediate transfer member, the cleaning means is a fur brush or a charging roller, and the intermediate transfer member has a specific maximum displacement quantity (Sb) and has a specific elastic deformation percentage (Eb) (%); a toner which forms the toner image has a specific average circularity, has a specific maximum displacement quantity (St), and has a specific elastic deformation percentage (Et) (%); and the elastic deformation percentage of the intermediate transfer member and the elastic deformation percentage of the toner satisfy the

Abstract: The present invention provides: a toner kit having a deep toner and a pale toner which are separated from each other, wherein: the deep toner and the pale toner satisfy prescribed conditions for an L*a*b* color coordinate system where a* represents a hue in the red-green direction, b* represents a hue in the yellow-blue direction, and L* represents a lightness; the pale toner and the deep toner to be used in the toner kit; and a method for forming an image using the toner kit. Thus, the present invention can form a high quality image, while suppressing graininess and roughness over the areas covering from the low density area to the high density area.

Abstract: A process contains in which heating and fixing an image of a toner on a recording medium is performed by heating one or more heat-transfer media by a heating element, and pressing the recording medium bearing the toner image to one of the heat-transfer media. At least one of the heat-transfer media is a belt heat-transfer medium with or without the application of an oil whose amount is 4 mg or less per A4 size, and the toner contain a binder resin and a releasing agent, has a weight-average particle diameter Dv of 3.0 to 7.0 ?m, a particle diameter distribution Dv/Dn of 1.00 or more and 1.25 or less, wherein Dn is a number-average particle diameter, and an average shape factor SF-1 of 100 to 150 and contains toner particles having a shape factor SF-1 of 160 or more in an amount of 10% by number or less.

Abstract: A toner for an electrophotography comprising a resin and a colorant is disclosed. The toner is formed by a process including a step of aggregating resin particles, and the toner comprises a volatile ketone compound in an amount of 4-60 ppm and carnauba wax in toner particles.

Abstract: A toner for developing an electrostatic image is disclosed. The toner contains an amount of not less than 0.1% by weight of an element selected from elements of the Groups of 1B, 2B, 4B, 5B, 6B, 7B, 8, 3A and 4A of the fourth and fifth periodic of the long periodic table of the elements, and the isolation ratio of the element is not more than 10% by number.

Abstract: A toner which includes a toner material, wherein the toner satisfies the following formula: 0° C.??Tm?20° C. where ?Tm represents Tma (° C.)?Tmb (° C.), Tma (° C.) is ½ flown-out temperature of the toner by a capillary type flow tester, and Tmb (° C.) is ½ flown-out temperature of a melt kneaded mixture of the toner by the capillary type flow tester, and wherein Tma is from 130° C. to 200° C.

Abstract: An electrostatic image forming method is described. The method includes forming latent images corresponding to yellow, magenta and cyan images on a photoreceptor, developing corresponding latent images by developers containing yellow, magenta and cyan toner to form yellow, magenta and cyan images and transferring the yellow, magenta and cyan images on a recording material, and the yellow toner and the magenta have specific reflectance characteristics described in the specification.

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 in which mother toner particles containing at least a resin binder and a colorant are coated with an external additive, wherein the mother toner particles contain fine powders of a fluororesin having an average particle size of 1 ?m or less in an amount of from 4 to 10 parts by weight, based on 100 parts by weight of the resin binder, and a toner in which mother toner particles containing at least a resin binder and a colorant are coated with an external additive, wherein the external additive contains fine powders of a fluororesin having an average particle size of 1 ?m or less in an amount of from 0.3 to 2 parts by weight, based on 100 parts by weight of the mother toner particles. The toner of the present invention is suitably used for, for example, developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.

Abstract: An electrostatic latent image developing toner including, as a binder resin, a crystalline resin and at least one kind of non-crystalline resin, wherein, in a dynamic viscoelasticity measurement by a sine wave vibration method, a minimum value of the relaxation elasticity H in a relaxation spectrum obtained from frequency dispersion characteristics measured at temperatures of 60 and 80 degrees centigrade with a measurement frequency set in the range of 0.1 to 100 rad/sec and measurement strain set in the range of 0.02 to 4.5% is in the range of 10 to 900 Pa/cm2, and a relaxation time ? corresponding to the minimum value is in the range of 1 to 10,000 sec.

Abstract: A toner containing toner particles having a core-shell structure containing a binder resin, a colorant and a release agent. The toner particles are prepared by dissolving or dispersing at least one of the binder resin and a precursor thereof in an organic solvent or a polymeric monomer and reacting the resultant in an aqueous medium for reaction, wherein the toner satisfies the following relationship: ?Tm=Tm1?Tm2>10 ° C., wherein Tm1 represents half efflux temperature of the toner and Tm2 represents half efflux temperature of a toner which is prepared by melting and kneading the toner particles and wherein a content of the release agent existing close to the surface portion of the toner particles is from 7 to 30% by volume based on an entire portion close to the surface portion of the toner particles when the content is determined by Fourier Transform Infrared Spectroscopy Attenuated Total Reflection (FTIR-ATR) method.

Abstract: An electrophotographic toner comprising a resin, a colorant and a release agent which comprises a first wax and a second wax, wherein: (i) the first wax exhibits: an endothermic peak appearing in the range 75-100° C., a peak width at half height of the endothermic peak of 10-40° C., an exothermic peak appearing in the range 70-100° C. and a peak width at half height of the exothermic peak of 10-40° C., in a DSC measurement; (ii) the second wax exhibits: an endothermic peak appearing in the range 60-90° C., a peak width at half height of the endothermic peak of 5° C. or less, an exothermic peak appearing in the range 55-80° C. and a peak width at half height of the exothermic peak of 5° C. or less, in the DSC measurement; (iii) a weight ratio of the first wax to the second wax is between 9:1 and 2:8; and (iv) the resin contains a polar group.

Abstract: An eletrophotographic toner comprising toner particles each containing a colorant and a resin, wherein the resin in the toner particle satisfies the following Formulas (1) and (2): Formula (1) 20?Tg?40, Formula (2) 15?(Ta?Tg)?40, wherein Tg (° C.) is a glass transition point of the resin; and Ta (° C.) is a 50% aggregation temperature of the resin.

Abstract: A yellow toner in which, in a spectral-distribution diagram in which the reflectance (%) is plotted as ordinate and the wavelength (nm) as abscissa, the reflectance determined for a toner in a state of powder ranges from 15% to 20% at a wavelength of 500 nm and ranges from 75% to 80% at a wavelength of 600 nm, a cyan toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 30% to 35% at a wavelength of 450 nm and ranges from 35% to 40% at a wavelength of 475 nm, and a magenta toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 5% to 10% at a wavelength of 425 nm and ranges from 65% to 70% at a wavelength of 675 nm. These color toners each contain corresponding pigments in specific combination, and promise color reproduction which can ensure the color tones of process inks.

Abstract: The invention provides a developer having at least a toner, an aeration ratio (AR) of the developer measured by a powder rheometer being in a range of about 5.0 to about 10.0. It is preferable that the developer further contains an external additive of silica particles having a small diameter. The invention further provides a process cartridge having at least: a photoreceptor; and a developing device that comprises plura developer storage portions and that makes visible a latent image formed on the photoreceptor by using the developer. The invention further provides an image forming apparatus having at least the process cartridge.

Abstract: The present invention provides a developing process including the steps of charging toner particles supported on a developer carrier; and providing the charged toner particles to an electrostatic latent image formed on an image carrier, wherein, the charged toner particles satisfy formulas (1) and (2) shown below, when being measured by the laser doppler method in an oscillation field in an acoustic alleviation cell to determine individual particle size and charged amount thereof: k1=(B2?B1)/(A1?A2)<???(1) B2<0??(2) wherein A1 [?m] and B1 [fC] represent the particle size and the charged amount of the charged toner particle in the division that has the largest number proportion in the distribution divided by the measured particle size and the measured charged amount, respectively; A2 [?m] represents the particle size in the division that has the smallest particle size in the particle size distribution, provided that the number proportion of the division is 1% or more; and B2 [fC] represents the charge

Abstract: A toner that when the complex elastic modulus measured at an angular frequency of 6.28 rad/sec., and a strain amount of 0.3% is 1×106 Pa or more and 1×108 Pa or less, the tangent loss is 0.5 or more and 1.8 or less.

Abstract: An image forming apparatus, including a latent image-holding member, a developing unit, a transfer unit, a cleaning unit, and a recycling unit, wherein the developer includes a toner having an external-additive adhesiveness index SA in the range of approximately 50% to approximately 95% and: a carrier containing magnetic particles and a coating layer coating the surface of the magnetic particles and having a total energy of approximately 1,420 to approximately 2,920 mJ; or a carrier containing magnetic powder-dispersed particles and a coating layer coating the surface of the magnetic powder-dispersed particles and having a total energy of, approximately 890 to approximately 1,390 mJ.

Abstract: The invention provides a toner for electrostatic charge development including a binder resin and an infrared absorber, wherein at least one of the infrared absorbers is a compound represented by Structural Formula (1).

Abstract: A toner including a binder resin; a colorant; a release agent; and a modified layered inorganic material in which at least part of interlayer ions is modified with an organic ion, wherein the toner has a volume average particle diameter (Dv) of 3 to 7 ?m and a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) of the toner of 1.00 to 1.30, and wherein the release agent is included in the toner in an amount (A) of 1 to 10% by weight, and the ratio (B/A) of the amount (A) to the amount (B) of the release agent included in a classified toner in units of percent by weight is 0.7 to 1.3, wherein the classified toner satisfies the relationship (Dv?/Dn??1)/(Dv/Dn?1)?3/4 wherein Dv? and Dn? respectively represent the volume and number average particle diameters of the classified toner.

Abstract: To provide a pulverized toner including: a wax-containing resin; a coloring material; and an external additive, wherein the pulverized toner has an average circularity of 0.890 to 0.930, a particle diameter of 6 ?m to 10 ?m, and a torque of 1.0 mNm to 2.5 mNm at a vacancy ratio 58% in the pulverized toner as measured by a torque measuring method using a conical rotor, and wherein the pulverized toner is a wax-containing pulverized toner for non-magnetic one component development.

Abstract: A method for forming an image contains steps of: transferring a toner having a volume average particle diameter of 5 ?m or less to a recording medium as a toner image having a monochromatic maximum toner mass per area of 0.35 mg/cm2 or less; and fixing the toner image at a surface temperature of a fixing roll which is 130° C. or less. The toner preferably has 0.02 log(Pa)/° C. or less of a gradient of a storage, elasticity per temperature in a temperature range of from Tm+20° C. to Tm+50° C. Here, Tm represents a melting temperature of a crystalline resin contained in the crystalline toner.

Abstract: The invention provides: an electrostatic latent image developing toner comprising a non-crystalline resin, a crystalline resin having a melting point of 50 to 100° C., and a colorant, and satisfying the relationship represented by the following formula (1), wherein A represents the content of the crystalline resin (% by mass) in the entire toner, and B represents the content of the crystalline resin (% by mass) in a classified toner which has been prepared by classifying the toner such that the volume average particle diameter thereof is in the range of (?)×D50T to (?)×D50T, wherein D50T represents the volume average particle diameter of the entire toner, and a method for producing the same, as well as an electrostatic latent image developing developer, a toner cartridge, a process cartridge, and an image forming apparatus using the same.

Abstract: A toner composition preparation method is provided which can improve dispersibility of a colorant in a toner composition to form images of a high quality, enhance the fixing property and fluidity of the toner, and prevent a developing member from being contaminated due to inferior dispersibility of the colorant. According to the exemplary embodiment of the present invention, the toner composition preparation method by mixing a first binder resin with a colorant to prepare a master batch mixture; and adding a second binder resin, a releasing agent and a charge controlling agent to the obtained master batch mixture to produce the toner composition, wherein a melting point of the first binder resin is lower than that of the second binder resin.

Abstract: A toner composition is provider including a branched amorphous polyester resin and a crystalline polyester resin, wherein the toner possesses rheological properties yielding desired characteristics.

Abstract: The color toner for developing electrostatic latent images comprising a colored resin particle containing at least a binder resin, a colorant, a charge control agent and a parting agent, wherein an extracted liquid with water by means of a hot water extraction method from said colorant has a pH value in the range from 6.0 to 8.0, said colored resin particle has a volume average particle diameter (Dv) in the range from 4 to 10 ?m and an average circularity in the range from 0.93 to 0.995, an amount of extracted components with methanol is 7% by weight or less, and an amount of residual volatile compounds is 500 ppm or less. The color toner for developing electrostatic latent images has excellent image-reproducibility and environmental durability and can form an image with a stable image density under a high temperature and high humidity condition.

Abstract: An image forming method includes: forming an electrostatic latent image after charging an organic photoconductor; and developing the electrostatic latent image into a toner image by bringing a developer containing toner and a carrier having a weight average particle size (D4) of 20 to 50 ?m into contact with the organic photoconductor comprising a photosensitive layer and a protective layer which is provided when needed, a total thickness of the photosensitive layer and the protective layer being 5 to 15 ?m.

Abstract: An electrophotographic developer comprising a toner and a carrier is disclosed. The toner contains a toner binder resin, a colorant and a releasing agent, and a carrier contains a magnetic particles dispersed in a carrier binder resin, wherein the releasing agent contained in toner is composed of from 40 to 98% by weight of a first releasing agent component of an ester compound and 60 to 2% by weight of a second releasing agent component of a hydrocarbon compound having a branched-chain structure, and the carrier has a shape coefficient SF-1 of from 1.0 to 1.2 and a shape coefficient S-2 of from 1.1 to 2.5, and a volume based median diameter of from 10 to 100 ?m.

Abstract: A resin particle dispersion liquid comprises: resin particles comprising polyester having terminal carboxyl groups, the polyester being obtained by polycondensation of a polycondensable monomer, wherein the polyester has the terminal carboxyl groups that are partially neutralized to form carboxyl anions, the resin particles in the resin particle dispersion liquid having a value of (da/(da+dc)) of from approximately 0.30 to approximately 0.90, when in an absorption spectrum of the resin particles measured with an infrared spectrometer, dc represents a peak intensity of the terminal carboxyl group in a range of from 1,780 to 1,680 cm?1, and da represents a peak intensity of the neutralized carboxyl anion in a range of from 1,670 to 1,550 cm?1, the polyester has an acid value of approximately 1 mg·KOH/g or more and less than approximately 15 mg·KOH/g before neutralization, the resin particles dispersion liquid comprises a divalent or higher organic acid in an amount of from approximately 0.

Abstract: A negatively-chargeable non-magnetic one-component developer for developing an electrostatic latent image using a contact DC-bias development method, having a capacitance of 1.05×10?12 to 1.25×10?12 F, a volume resistivity of 5.0×1010 to 5.0×1012 ?·cm and a dielectric loss tangent of 1.0×10?3 to 2.0×10?2. In a contact DC-bias development method, the developer has a capacitance of 1.30×10?12 to 1.60×10?12 F, a resistivity of 5.0×109 to 5.0×1010 ?·cm and a dielectric loss tangent of 1.0×10?3 to 2.0×10?2. In a non-contact DC/AC-bias development method, the developer has a capacitance of 1.45×10?12 to 1.60×10?12 F, a resistivity of 5.0×109 to 1.0×1010 ?·cm and a dielectric loss tangent of 1.0×10?3 to 2.0×10?2.

Abstract: An image forming method, including forming an unfixed toner image on the surface of paper by an electrophotographic process using a developer containing a toner, and fixing the toner image on the paper, wherein a toner amount of the unfixed toner image is in the range of about 2.0 to 4.5 g/m2 for a toner image formed using a toner of one color, and in the range of about 8.0 to 18 g/m2 for a toner image formed by layering toners of four or more colors, and a bulk density of the toner is in the range of about 0.2 to 0.5 g/cm3.

Abstract: A toner for developing an electrostatic latent image that includes a crystalline polyester resin and a release agent, wherein structures in which the crystalline polyester resin contacts the release agent exist in a ruthenium-stained cross section of the toner, and if the cross-sectional area of these structures is labeled A, the cross-sectional area of lone portions of the release agent is labeled B, and the cross-sectional area of lone portions of the crystalline polyester resin is labeled C, then 40?100×A/(A+B+C)?70, 10?100×B/(A+B+C)?30, and 20?100×C/(A+B+C)?30.

Abstract: A toner comprising toner particles comprising a first binder resin; a second binder resin different from said first binder resin and having a glass transition temperature of from 40 to 55° C.; a colorant; and a release agent, and a particulate resin material which is located on surface of the toner particles with a coverage of from 50 to 100%, and which has a glass transition temperature of from 50 to 90° C., wherein a weight ratio (W2/W1) between the second binder resin (W2) and the first binder resin (W1) is from 5/95 to 40/60, and wherein a ratio (G?80/G?180) between a storage modulus of the toner at 80° C. (G?80) and a storage modulus at 180° C. (G?180) is from 100 to 1,000.

Abstract: An electrophotographic toner is disclosed, meeting the requirement that a ratio of a storage modulus at 60° C. [G?(60)] to a storage modulus at 80° C. [G?(80)], G?(60)/G?(80) is from 1×102 to 1×104; a ratio of a storage modulus at 100° C. [G?(100)] to a storage modulus at 120° C. [G?(120)], G?(100)/G?(120) is from 1 to 10; and a storage modulus at a temperature of from 140 to 160° C., [G?(140-160)] is not less than 102 dyn/cm2.

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: The present invention provides an image forming method for obtaining excellent color fixed images with a smaller amount of light energy. This image forming method includes the steps of: forming a toner layer of a color toner containing at least a binder resin, a coloring agent, and an infrared absorbent, on a recording medium; and fixing the toner layer by flashlight emission, where the relationship among the PAS level S of the color toner that is obtained by integrating an infrared PAS spectrum obtained through PAS (photoacoustic spectroscopy) analysis in the range of 800 nm to 2000 nm, the melt viscosity ? of the color toner at a reference temperature, and the energy E of the flashlight, is expressed by the following relational expression: 1000??/E·S?5500.

Abstract: A toner having a BET specific surface area of from 1.5 to 3.5 m2/g, obtainable by a process including the steps of; step (1): pulverizing a toner composition containing at least a resin binder and a colorant in the presence of fine inorganic particles having an average primary particle size of from 6 to 20 nm to obtain mother toner particles having a volume-median particle size of from 3 to 8 ?m; and step (2): externally adding silica having an average primary particle size of from 25 to 60 nm to the mother toner particles obtained in the above step (1). The toner of the present invention is suitably used for, for example, developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.

Abstract: An electrophotographic toner contains a resin, a colorant and a releasing agent. The releasing agent has a solidifying point of from 79° C. to 109° C., and one peak in an endothermic curve measured by a differential scanning calorimeter. A difference between temperature to give a maximum endothermic peak of the releasing agent and an end-set temperature of the releasing agent is within 10° C. A melt viscosity of the releasing agent at 110° C. is in a range of from 4 mPa·s to 9 mPa·s. The releasing agent in one particle of the toner forms 3 or more domains. Domains having a ratio of a major axis to a minor axis which is in a range of from 5 to 15 occupy 90% or more by number based on the total number of domains.

Abstract: To provide a black toner having excellent charging property and transferring property against a severe environmental change. The black toner includes toner particle containing at least a binder resin, carbon black and a releasing agent, wherein: the toner particles have a weight-average particle diameter of 3.5 to 8.0 ?m; total amount of acid value and hydroxyl value of the toner is 30 to 75 mgKOH/g; average circularity of particles contained in the toner having circle-equivalent diameter of 2 ?m or more is 0.915 to 0.960; loss tangent tan? (103 to 104 Hz) of the toner is represented by the following expression: tan? (103 to 104 Hz)?0.0060 where the loss tangent tan? is represented by ??/?? where ?? denotes dielectric loss factor and ?? denotes dielectric constant, and tan? (103 to 104 Hz) denotes the loss tangent in a frequency range of 103 to 104 Hz; and a ratio of tan? (105 Hz) to tan? (5×104 Hz) is represented by the following expression: 1.05?tan? (105 Hz)/tan? (5×104 Hz)?1.

Abstract: The developing device 100 includes a stirrer and transferor 122, 124, a magnetic roller 130, and a developing roller 140, that are disposed in a housing 110 which contains the two-component developing agent including the magnetic carrier and the non-magnetic toner, wherein volumetric mean particle size of the non-magnetic toner is set in a range from 6 to 11 ?m and proportion of toner particles not larger than 4 ?m is set to 8% by number or less, thereby making it possible to prevent imaging defect (ghost) and sticking of the toner onto the developing roller from occurring.

Abstract: A toner for developing an electrostatic image having a good combination of hot offset resistance and low temperature fixability. The toner includes (1) a resin having at least one group that can react with a compound having an active hydrogen in an amount of 2 pieces per molecule of the resin, and a colorant. The toner satisfies the following relationship: 3?G=R?Rideal?20, where G represents a ratio of a weight of components other than the colorant and the resin that are insoluble in the organic solvent to total weight of the toner, R represents a weight ratio of components included in the toner that are insoluble in the organic solvent to the total weight of the toner, and Rideal represents an ideal weight ratio of the colorant and the resin, which is calculated from a formula of the toner.

Abstract: The present invention provides a toner for electrostatically charged image development comprising at least a binder resin, a colorant and a releasing agent. The releasing agent satisfies the following equations (1) and (2): 0.1??*a?1.0??(1) 1.1??*b/?*a?3.5??(2) wherein ?*a represents a complex viscosity (Pa·s) determined from a first dynamic viscoelasticity measurement at a measuring frequency of the releasing agent of 6.28 rad/s, ?*b represents a complex viscosity (Pa·s) determined from a second dynamic viscoelasticity measurement at a measuring frequency of the releasing agent of 62.8 rad/s, and each of the first and second dynamic viscoelasticities is measured in a temperature range from a temperature that is 15° C. lower than the melting point of the releasing agent to a temperature that is 15° C. higher than the melting point of the releasing agent.

Abstract: An electrophotographic toner having a core-shell structure including a crystalline resin in its core region or a sea-island structure including a crystalline resin in its island region, wherein the toner has 1) a resistance of 5.0×1012 ?·cm or higher, 2) a dynamic viscosity coefficient of 3×103 Pa·s or higher at a temperature which is 50° C. higher than a melting point of the crystalline resin, and 3) a dynamic viscosity coefficient of 1×105 Pa·s or lower at a temperature which is 10° C. higher than the melting point of the crystalline resin.

Abstract: A toner composition includes a styrene-based polymer resin, a crystalline polyester wax, a second wax different from the crystalline polyester wax, a colorant, and a coagulant.

Abstract: A toner for electrophotography, wherein the toner is prepared by a suspension polymerization or emulsion polymerization from a monomer composition comprising a monovinyl monomer and a coloring agent, and a filtration velocity of the toner is in the range of 0.1 to 3.0 mL/min. The filtration velocity is obtained by an evaluation method comprising following evaluation steps: (i) 15 mg of a toner is added to 5 mL of THF, and soluble component in the toner is dissolved in THF completely to prepare a sample liquid; and (ii) the sample liquid is filtrated at the temperature of 25° C. and pressure of 0.15 kgf/cm2 is applied using a filter wherein an area thereof is 4.0 cm2 and a pore size thereof is 0.45 ?m to measure a filtration time wherein 1 mL of the sample liquid is passed through the filter, and a filtration velocity is determined using the filtration time by a following formula, Filtration velocity (mL/min)=1 (mL)/filtration time (min).

Abstract: A toner which excels in offset resistance at a high temperature and a low temperature and fixing performance and which can perform fixation at a low temperature is provided. Such a toner is one which includes toner mother particles, such that a temperature T° C. satisfies the following relationship: ?(T+5)/?(T)?1 provided that a melting viscosity at a temperature T° C. is expressed as ?(T) and a melting viscosity at a temperature (T+5)° C. is expressed as ?(T+5).

Abstract: An oilless-fixing toner is provided for use in a vertical image developer including a toner feeder feeding the oilless-fixing toner vertically below; a developing roller located vertically below the toner feeder; and a screw blade agitating the oilless-fixing toner, wherein the oilless-fixing toner contains: a resin including a wax; a colorant; and an external additive, wherein a total energy determined from a torque and a load of the screw blade is from 450 to 530 mJ when rotating in the oilless-fixing toner at 100 mm/s, and a ratio of total energy at 10 mm/s to total energy at 100 mm/s is from 2.0 to 3.0.

Abstract: A magnetic carrier composed of carrier particles is provided in which each carrier particle has a carrier core including magnetic fine particles and a binder resin with the carrier core surface being coated with a coat material containing a coat resin. In the magnetic carrier, Fatom/Catom and (Fatom/Catom)/(Fcalc/Ccalc) are respectively in specific ranges, wherein Fatom and Catom represent respectively a fluorine element abundance ratio and a carbon element abundance ratio at the magnetic carrier particle surface, and Fcalc and Ccalc represent respectively a fluorine element abundance ratio and a carbon element abundance ratio which are calculable from the molecular structure of the coat resin. In addition, a two-component developer is provoded including the magnetic carrier and a toner having a specific contact angle against water.

Abstract: An electrophotographic image forming apparatus capable of reliably forming an image with density gradation, one which does not have a low-quality appearance. The estimated average halftone granularity of the toner image after developing but before electrostatic transfer was set at 0.25 or less. The average halftone granularity was found by measuring the granularity of a toner image at locations of different average brightness by means of newly proposed formula, and averaging the measured values for which the average brightness is 40 to 80. The estimated average halftone granularity was obtained by estimating the average halftone granularity of the toner image on a photoreceptor by means of a newly proposed method.