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??(1).

Abstract: An electrostatic latent image developing magenta toner includes at least quinacridone pigment, naphthol pigment, and a release agent. Colorant of the toner satisfies conditions (a) and (b): (a) an average primary particle size D50 of a quinacridone pigment represented by formula (1) and an average primary particle size D50 of a naphthol pigment represented by formula (2) are such that the average primary particle size D50 of the quinacridone pigment is smaller than the average primary particle size D50 of the naphthol pigment; and (b) the average primary particle size D50 of the quinacridone pigment is greater than 20 nm, and the average primary particle size D50 of the naphthol pigment is smaller than 200 nm. Formula (1): Here, each of R1, R2, R3, and R4 is selected from the group consisting of H, CH3, and Cl, R1 and R2 are different from each other, and R3 and R4 are different from each other.

Abstract: The present invention provides a tandem-type image forming method using a trickle developing system, wherein the average circularity of a toner contained in at least a supplementary developer used for appropriately supplying a developer to a developing device is in the range of 0.940 to 0.980. In the toner, the ratio of the number of particles having an average circularity of 0.970 or greater, in a particle diameter range of a toner circle-equivalent diameter×⅗ or less, is 5% or less, and the ratio of the number of particles having an average circularity of 0.950 or less, in a particle diameter range of a toner circle-equivalent diameter×{fraction (7/5)} or greater, is 10% or less.

Abstract: An electrophotographic magenta toner which comprises a binder resin and a colorant comprising (a) 0.5 to 15 parts by weight of C.I. Pigment Red 57:1 and (b) 0.5 to 15 parts by weight of C.I. Pigment Red 81 or C.I. Pigment Red 122, per 100 parts by weight of the toner. A magenta developer comprising the magenta toner, and a full color image forming method using the magenta toner or developer are also disclosed.

Abstract: An electrophotographic image forming method includes a charging step, an exposure step, a developing step and a transfer step in the rotation of an electrostatic latent image bearing member, in which a process speed of the electrostatic latent image bearing member is 200 to 500 mm/sec, an outer diameter of the electrostatic latent image bearing member is 15 to 35 mm, an outer diameter of a developer bearing member is 10 to 25 mm, and a magnetic single component developer of which the residual magnetization in a measured magnetic field of 796 kA/m is 0.5 to 5.0 Am2/kg is used as the developer. The electrophotographic image forming method can provide a good image quality without causing scattering of toner in downsizing, weight reduction of an electrophotographic apparatus and speed-up of an electrophotographic process.

Abstract: A full color electrophotographic toner including toner particles containing at least a binder resin, a colorant and a wax, and external additives, at least one of the external additives being rutile titanium oxide having a volume resistivity of 1×1014 to 1×1018 &OHgr;cm, and a dispersion absolute deviation a of rutile titanium oxide being 0.17 or less, and a full color electrophotographic developer and an image forming method using the same are provided. In the full color electrophotographic toner, the full color electrophotographic developer and the image forming method of the invention, a retransfer phenomenon of the transferred toner can be prevented, a chargeability and a transferability are not problematic at all, a charging amount of the toner in long-term use can be rendered appropriate and stable, and a fluidity is also excellent.

Abstract: An electrophotographic image forming method includes a charging step, an exposure step, a developing step and a transfer step in the rotation of an electrostatic latent image bearing member, in which a process speed of the electrostatic latent image bearing member is 200 to 500 mm/sec, an outer diameter of the electrostatic latent image bearing member is 15 to 35 mm, an outer diameter of a developer bearing member is 10 to 25 mm, and a magnetic single component developer of which the residual magnetization in a measured magnetic field of 796 kA/m is 0.5 to 5.0 Am2/kg is used as the developer. The electrophotographic image forming method can provide a good image quality without causing scattering of toner in downsizing, weight reduction of an electrophotographic apparatus and speed-up of an electrophotographic process.

Abstract: There is provided an electrostatic charge image developing toner comprising at least a binder resin, a coloring agent, and an aromatic hydrocarbon copolymer resin, wherein, in a toner particle, the percentage of dispersed aromatic hydrocarbon copolymer resin particles having a longitudinal diameter of 2.0 .mu.m or greater among the total number of dispersed aromatic hydrocarbon copolymer is 10% or less. The toner has superior effects of excellent grindability and not melting and adhering to apparatuses, without there being any adverse effect on basic abilities of the toner such as electrostatic charge property, fixing property, color, and the like.

Abstract: An electrostatic-image developer which comprises: (i) a toner comprising: (a) toner particles containing carbon black in an amount of from 6 to 8% by weight based on the weight of the toner particles and having a volume-average particle diameter of from 3 to 9 .mu.m; and (b) an external additive; and (ii) a resin-coated carrier having a volume resistivity of from 10.sup.7 to 10.sup.11 .OMEGA..multidot.cm in an electric field of 10.sup.3.8 V/cm and an average particle diameter of from 30 to 60 .mu.m. Also disclosed are a process for forming a black image and a process for forming a full-color image each using the electrostatic-image developer.

Abstract: A toner for electrostatic-image development which comprises toner particles comprising a colorant and a binder resin, the toner particles having a volume-average particle diameter of from 3 to 9 .mu.m and a particle size distribution satisfying the following expressions (1) and (2):D16(v)/D50(v).ltoreq.1.475-0.036.times.D50(v) (1)D50(p)/D84(p).ltoreq.1.45 (2)wherein D16(v) and D50(v) represent, in terms of absolute value, a cumulative 16% diameter (.mu.m) and a cumulative 50% diameter (.mu.m), respectively, of a cumulative volume particle diameter distribution of the toner particles depicted from the larger diameter side, and D50(p) and D84(p) represent, in terms of absolute value, a cumulative 50% diameter (.mu.m) and a cumulative 84% diameter (.mu.m), respectively, of a cumulative population particle diameter distribution of the toner particles depicted from the larger diameter side.

Abstract: A toner composition for electrophotography comprising toner particles comprising a binder and a colorant and an additive, wherein the additive is crystalline titanium dioxide fine particles which have been treated with a coupling agent and which have a specific surface area of 60 to 100 m.sup.2 /g and a Karl Fischer moisture content of not more than 5% by weight. Compounds represented by formulae (I), (II) or (III) are used as the coupling agent:R.sup.1 Si(X).sub.3 (I)R.sup.1' R.sup.2 Si(X).sub.2 (II)R.sup.1' R.sup.2 R.sup.3 SiX (III)wherein R.sup.1 represents an alkyl group having 9 to 20 carbon atoms; R.sup.1' represents an alkyl group having 1 to 20 carbon atoms; R.sup.2 and R.sup.3 each represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 30 carbon atoms; and X represents a chlorine atom, an alkoxy group having 1 to 10 carbon atoms or an acetoxy-group having 3 to 5 carbon atoms.

Abstract: A surface-treated inorganic fine particle includes an inorganic fine particle, a hydrophobizing agent deposited on the surface of the inorganic fine particle and an amino group-containing coupling agent deposited on the surface of the inorganic fine particle, wherein the hydrophobizing agent and the amino group-containing coupling agent in a ratio of 1/(0.01 to 0.1) by weight are deposited on the surface of the inorganic fine particle by treating the surface of the inorganic fine particle with the hydrophobizing agent and the amino group-containing coupling agent. An electrophotographic developer contains toner particles and the surface-treated inorganic fine particles.

Abstract: A color toner providing a toner image excellent in brightness, clearness and graininess and a process for producing the same are disclosed, wherein a proportion of dispersed pigment particles having a circle-equivalent diameter of 0.3 .mu.m or greater does not exceed 0.1% of the total number of said dispersed pigment particles. The process comprises kneading a water-containing pigment paste and a binder resin at a temperature of 100.degree. C. or higher under pressure in a heat and pressure kneader to remove a water content to obtain a pigment dispersion, melt-kneading the resulting pigment dispersion together with a binder resin, and grinding the mixture.

Abstract: An electrophotographic toner composition comprising (A) toner particles with an average particle diameter of 9 .mu.m or less comprising at least a binder resin and a colorant, and (B) an additive, wherein the additive is a fine metal oxide powder surface coated with at least one agent for imparting hydrophobic property selected from the group consisting of the following formulae (1), (2) and (3):R.sub.1 Si(X).sub.3R.sub.1 R.sub.2 Si(X).sub.2R.sub.1 R.sub.2 R.sub.3 Si(X).sub.1wherein R.sub.1 represents a substituted or unsubstituted alkyl group having a molecular weight of 113 or more, R.sub.2 and R.sub.3 each represents hydrogen, an alkyl group or an allyl group, and X represents chlorine, an alkoxy group or an acetoxy group. The toner composition causes no impaction to a carrier and no adhesion of the toner particles to a photoreceptor, and can form stable, sufficient images for a long time.

Abstract: A toner for developing an electrostatic charge image is disclosed, which is formed by adding and mixing an external additive with toner particles having an average particle size of not larger than 9 .mu.m and comprising at least a colorant and a binder resin, wherein the external additive is fine particles having a particle size of 20 to 80 nm. There is also disclosed a process for preparing the toner which comprises adding external additives to the toner particles and mixing them, wherein the addition and mixing of said external additive are carried out under specific conditions.

Abstract: A method for fixing a full color toner image by inserting a transfer medium to which a toner image is transferred, between a pair of rolls of a fixing apparatus, and pressing the medium therebetween, wherein the toner image is formed of a full color toner prepared by dispersing a colorant into a polyester resin containing a diol component represented by the following general formula (I) as a constituent and having a softening point of 100.degree. to 120.degree. C., as measured by a ring and ball method, a glass transition temperature of 55.degree. C. or more, a Gardner color scale of 2 or less and a haze value of 15 or less, and the fixing operation is conducted while supplying a functional group-containing organopolysiloxane having a viscosity of 10 to 100,000 cs at 25.degree. C.