Abstract: A dry toner has toner particles containing at least a binder resin, a colorant and a wax component and an external additive. The binder resin contains a component derived from a monomer selected from butadiene, isoprene and chloroprene. The toner has a main Tg from 40° C. to 70° C. When specific surface area measured by the BET method in an environment of 23° C. atmospheric temperature and 65% relative humidity is represented by A (m2/g) and specific surface area measured by the BET method in an environment of 50° C. atmospheric temperature and 3% relative humidity is represented by B (m2/g), the toner satisfies the following relationship: 0.8≦A≦4.0, 0.80≦(B/A)≦1.05. The toner has a circle-corresponding number-average particle diameter D1 from 2 to 10 &mgr;m, an average circularity from 0.950 to 0.995 and a circularity standard deviation less than 0.040. The toner has a main-peak molecular weight from 2,000 to 100,000 and contains a THF-insoluble matter from 5 to 60% by weight.

Abstract: A toner is comprised of a binder resin, a colorant and a wax. The binder resin has a polycarbonate resin in an amount of from 0.1% by weight to 50.0% by weight and a resin other than the polycarbonate resin in an amount of from 50.0% by weight to 99.9% by weight, based on the weight of the binder resin. In molecular weight distribution as measured by gel permeation chromatography of tetrahydrofuran-soluble matter, the toner contains in an amount of 15.0% by weight or less based on the weight of the toner a component which has in its structure a repeating unit of the polycarbonate resin and is contained in components having a molecular weight of 1,000 or less.

Abstract: A magnetic toner comprising magnetic toner particles containing at least a binder resin, a magnetic material containing a magnetic iron oxide, and a release agent. The magnetic toner has a weight-average particle diameter of from 3 &mgr;m to 10 &mgr;m, a magnetization intensity (saturation magnetization) of from 10 Am2/kg to 50 Am2/kg (emu/g) under application of a magnetic field of 79.6 kA/m (1,000 oersteds), an average circularity of 0.970 or more, a ratio of weight-average particle diameter to number-average particle diameter, of 1.40 or less, iron and an iron compound which stand liberated from the magnetic toner particles at a liberation percentage of from 0.05% to 3.00%, and a resin component having a tetrahydrofuran-insoluble matter in an amount of from 3% by weight to 60% by weight. Also disclosed is an image-forming method making use of the magnetic toner.

Abstract: Magnetic particles for charging means disposed in contact with an electrophotographic photosensitive member for charging the electrophotographic photosensitive member based on a voltage applied thereto are provided as particles of a ferrite component represented by the following formula (1): (Fe2O3)X(A)Y(B)Z  (1), wherein A denotes at least one metal oxide component selected from the group consisting of Li2O, MnO and MgO, B denotes at least one metal oxide component different from A; X, Y and Z denote numbers representing mol ratios and satisfying the following conditions: 0.2<X<0.95, 0.01<Y<0.5, X+Y≦1, and 0≦Z<0.79. The magnetic particles show an excellent charging performance, particularly in injection charging, without causing a difficulty, such as soiling or pinhole leakage of the photosensitive member.

Abstract: A magnetic toner includes: magnetic toner particles each comprising at least a binder resin and magnetic toner, and inorganic fine powder. The magnetic toner has an average circularity of at least 0.970, and a magnetization of 10-50 Am2/kg at a magnetic field of 79.6 kA/m. The magnetic powder comprises at least magnetic iron oxide. The magnetic toner particles retain carbon in an amount of A and iron in an amount of B at surfaces thereof as measured by X-ray photoelectron spectroscopy, satisfying: B/A<0.001. The binder resin comprises a resin formed by polymerization of a monomer comprising at least styrene monomer. The magnetic toner has a residual styrene monomer content of less than 300 ppm, and contains at least 50% by number of toner particles satisfying a relationship of: D/C≦0.

Abstract: A toner is formed of toner particles each comprising a binder resin and iron oxide particles dispersed therein. The toner particles are characterized by uniform but non-surface-exposed dispersion of the iron oxide particles within the toner particles as represented by (i) a carbon content (A) and an iron content (B) giving a ratio B/A<0.001 at surfaces of the toner particles as measured by X-ray photoelectron spectroscopy, (ii) an average circularity of at least 0.970, and (iii) at least 50% by number of toner particles satisfying D/C≦0.02, wherein C denotes a projection area-equivalent circular diameter of each toner particle and D denotes a minimum distance of iron oxide particles from a surface of the toner particle, based on a sectional view of the toner particle as observed through a transmission electron microscope (TEM).

Abstract: A toner is comprised of a binder resin, a colorant and a wax. The binder resin has a polycarbonate resin in an amount of from 0.1% by weight to 50.0% by weight and a resin other than the polycarbonate resin in an amount of from 50.0% by weight to 99.9% by weight, based on the weight of the binder resin. In molecular weight distribution as measured by gel permeation chromatography of tetrahydrofuran-soluble matter, the toner contains in an amount of 15.0% by weight or less based on the weight of the toner a component which has in its structure a repeating unit of the polycarbonate resin and is contained in components having a molecular weight of 1,000 or less.

Abstract: A magnetic toner includes: magnetic toner particles each comprising at least a binder resin and magnetic toner, and inorganic fine powder. The magnetic toner has an average circularity of at least 0.970, and a magnetization of 10-50 Am2/kg at a magnetic field of 79.6 kA/m. The magnetic powder comprises at least magnetic iron oxide. The magnetic toner particles retain carbon in an amount of A and iron in an amount of B at surfaces thereof as measured by X-ray photoelectron spectroscopy, satisfying: B/A<0.001. The binder resin comprises a resin formed by polymerization of a monomer comprising at least styrene monomer. The magnetic toner has a residual styrene monomer content of less than 300 ppm, and contains at least 50% by number of toner particles satisfying a relationship of: D/C≦0.

Abstract: A magnetic toner comprising magnetic toner particles containing at least a binder resin, a magnetic material containing a magnetic ion oxide, and a release agent. The magnetic toner has a weight-average particle diameter of from 3 &mgr;m to 10 &mgr;m, a magnetization intensity (saturation magnetization) of from 10 Am2/kg to 50 Am2/kg (emu/g) under application of a magnetic field of 79.6 kA/m (1,000 oersteds), an average circularity of 0.970 or more, a ratio of weight-average particle diameter to number-average particle diameter, of 1.40 or less, iron and an iron compound which stand liberated from the magnetic toner particles at a liberation percentage of from 0.05% to 3.00%, and a resin component having a tetrahydrofuran-insoluble matter in an amount of from 3% by weight to 60% by weight. Also disclosed is an image-forming method making use of the magnetic toner.

Abstract: An image forming method comprises the steps of charging an electrostatic latent image bearing member, imagewise exposing the charged electrostatic latent image bearing member to form an electrostatic latent image thereon, developing the electrostatic latent image with a toner held on a toner holding member to form a toner image and transferring the toner image onto a transfer-receiving medium. The electrostatic latent image is developed by bringing a toner layer formed out of the toner held on the toner holding member into contact with the surface of the electrostatic latent image bearing member. The toner has toner particles containing at least a colorant, a wax and a binder resin. The wax: (a) in a DSC curve measured by a differential scanning calorimeter, shows an endothermic peak in a region from 50° C. to 130° C.

Abstract: The objects of the present invention are to provide a toner excellent in transferability, little remaining on the photosensitive member and causing no defective image in roll-aided transfer (or at least such a phenomenon is well-controlled), and also to provide an image forming method using the same toner. The above objects are achieved when the toner contains a binder resin and colorant, inorganic fine particles, and a hydrotalcite compound shown by the formula: M1y12+M2y22+ . . . Mjyj2+L1x13+L2x23+ . . . Lkxk3+(OH)2.(X/n)An−.mH2O  (1) wherein 0<[X=(x1+x2+ . . . xk)]≦0.5; Y=(y1+y2+ . . . +yj)=1−X; j and k are each an integer of 2 or larger; M13+, M23+, . . . and Mj2+ are divalent metallic ions different from each other; L13+, L23+ . . .

Abstract: A toner for developing an electrostatic image has toner particles containing at least a binder resin, a colorant, and a wax. The wax contains an ester compound represented by specific formula, or a mixture thereof at a content ranging from 50 to 100% by weight based on the weight of the wax.

Abstract: An image forming method includes charging an image carrier for carrying an electrostatic latent image;forming an electrostatic latent image on the charged image carrier;developing the electrostatic latent image with a toner by contacting a toner layer on a surface of a toner carrier with a surface of the image carrier to form a toner image thereon;copying the toner image formed on the surface of the image carrier onto a copy medium;wherein the toner has toner particles containing at least a bonding resin, carbon black and an azo-based iron compound and inorganic fine powder;the carbon black having an average primary particles size within a range of from 25 to 80 nm; andthe azo-based iron compound having a specific structure.

Abstract: A toner for developing electrostatic images is formed from toner particles containing at least a binder resin, a colorant, and a wax. The binder resin comprises a vinyl polymer component and a polyester component. The binder resin contains 40-99 wt. % of a component A, 0-20 wt. % of a component B, and 0-60 wt. % of a component C, the components B and C providing totally 1-60 wt. % of the binder resin. The component A comprises low- and medium-molecular weight components having molecular weights of below 10.sup.6, and the component B comprises high-molecular weight components having molecular weights of at least 106, respectively, based on a chromatogram obtained by gel permeation chromatography of a tetrahydrofuran (THF)-soluble component of the binder resin, and the component C is a THF-insoluble component of the binder resin. The GPC chromatogram of the THF-soluble component of the binder resin exhibits a main peak in a molecular weight region of 3.times.10.sup.3 -5.times.10.sup.4.

Abstract: A charging apparatus which comprises an electrophotographic photosensitive member and a charging member which comprises magnetic particles and placed in contact with the electrophotographic photosensitive member to charge the electrophotographic photosensitive member upon application of a voltage, wherein each magnetic particle has a surface layer containing a polyolefin resin of which weight average molecular weight is 10,000 or more, and has a volume resistivity of 1.times.10.sup.4 to 1.times.10.sup.11 .OMEGA.cm.

Abstract: An electrophotographic image forming method according to (I) a so-called simultaneous development and cleaning scheme or cleaner-less scheme is effectively operated by using a specific non-magnetic toner. (II) The non-magnetic toner comprises non-magnetic toner particles having a shape factor SF-1 of 120-160, a shape factor SF-2 of 115-140 and a weight-average particle size of 4-9 .mu.m. (III) The non-magnetic toner further includes inorganic fine particles (a) having a number-average primary particle size of at most 50 nm and spherical fine particles (b) having a number-average primary particle size of 50-1000 nm and a surface area-based sphericity .psi. of 0.91-1.00, respectively externally added to the non-magnetic toner particles.

Abstract: An electrophotographic apparatus is constituted by an electrophotographic photosensitive member, and a charger, imagewise exposing light and a developer disposed in this order opposite to the photosensitive member. The photosensitive member has a surface layer which is a charge-injection layer. The charger includes a charging member formed of magnetic particles and disposed contactable to the photosensitive member so as to charge the photosensitive member to at least 80% of a DC voltage supplied to the charging member. The magnetic particles have a volume resistivity in the range of 1.times.10.sup.4 -1.times.10.sup.9 ohm.cm, and the magnetic particles have a surface layer having a volume resistivity of at most 1.times.10.sup.9 ohm.cm.

Abstract: An image forming apparatus includes a member to be charged for carrying an electrostatic latent image; a contact charging means for contact charging the member to be charged and a developing means for developing the latent image. The developing means includes a developer having a magnetic toner and fine powder treated with a silicone oil or varnish-treating agent, wherein the magnetic toner particles include a binder resin and contain from 10-70 wt. % of magnetic fine powder. An image forming method includes the steps of contact charging, latent image forming and developing with a developer having the binder resin, 10 to 70 wt. % magnetic fine powder and fine powder treated with a silicone oil or varnish-treating agent.

Abstract: An image forming method has a developing step of developing an electrostatic latent image by the use of a developer to form a toner image on an electrostatic latent image bearing member, a primary transfer step of transferring the toner image onto an intermediate transfer member to which a voltage is applied, and a secondary transfer step of transferring onto a transfer medium the toner image held on the intermediate transfer member, while a transfer means to which a voltage is applied is pressed against the transfer medium. The developer has a toner. The toner is a black toner having at least i) black toner particles formed of a binder resin with a colorant dispersed therein and ii) an inorganic fine powder. The black toner has the value of shape factor SF-1 of 110<SF-1.ltoreq.180, the value of shape factor SF-2 of 110<SF-2.ltoreq.140, and the value of ratio B/A of 1.

Abstract: An image forming apparatus includes an image bearing member; developing-cleaning member for cleaning the image bearing member by removing residual toner from the image bearing member simultaneously with formation of a toner image by developing an electrostatic latent image formed on the image bearing member with toner having a charging polarity opposite from a charge polarity of the electrostatic latent image; transfer member for transferring the toner image from the image bearing member to a transfer material; and charging member for charging the toner remaining on the image bearing member after image transfer by the transfer member and before development by the developing-cleaning member to a polarity which is the same as the charging polarity of the toner image, and for charging the image bearing member to a polarity which is opposite from the charging polarity of the toner image.