Abstract: In a magnetic toner having toner particles containing at least a binder resin and a magnetic material, the binder resin is chiefly composed of a resin having a polyester unit synthesized using as a catalyst a tin compound represented by the following Formula (1), and the magnetic material has a number-average particle diameter of form 0.1 ?m to 0.3 ?m: (RCOO)2Sn??Formula (1) wherein R represents an alkyl group having 5 to 15 carbon atoms. This magnetic toner can attain a stable image density without dependence on environment and enables formation of high-grade images over a long period of time without causing scratches of latent image bearing members.

Abstract: In an image forming apparatus having at least an amorphous silicon photosensitive member, a magnetic toner developing means and a color developer developing means, the magnetic toner has a weight-average particle diameter (D4) of from 4.0 ?m to 10.0 ?m and a ratio thereof to number-average particle diameter (D1), D4/D1, of from 1.0 to 2.0, and the number of magnetic particles not passing through a mesh with an opening of 34 ?m which are contained in the unit volume of the magnetic toner is from 3.5 to 105. This image forming apparatus can not easily cause faulty cleaning performance even in using the magnetic toner and the non-magnetic color toners in combination and has superior environmental stability and running stability even where toners made to have small particle diameter are used or process speed is high.

Abstract: A toner comprises toner particles comprising at least a binder resin, a colorant, and a sulfur-containing resin, in which the toner particles comprise the sulfur-containing resin so as to satisfy a relation of; 0.50?IS/TS?0.95 where TS denotes a content of sulfur in the toner particles, and IS denotes a content of sulfur in isopropyl alcohol insoluble components of the toner particles, whereby it is possible to obtain a high quality image having an excellent developing resistance regardless of the surrounding conditions and a uniform charge amount distribution regardless of processing speed.

Abstract: In a magnetic toner having toner particles containing at least a binder resin and a magnetic material, the binder resin is chiefly composed of a resin having a polyester unit synthesized using as a catalyst a tin compound represented by the following Formula (1), and the magnetic material has a number-average particle diameter of form 0.1 &mgr;m to 0.

Abstract: In an image forming apparatus having at least an amorphous silicon photosensitive member, a magnetic toner developing means and a color developer developing means, the magnetic toner has a weight-average particle diameter (D4) of from 4.0 &mgr;m to 10.0 &mgr;m and a ratio thereof to number-average particle diameter (D1), D4/D1, of from 1.0 to 2.0, and the number of magnetic particles not passing through a mesh with an opening of 34 &mgr;m which are contained in the unit volume of the magnetic toner is from 3.5 to 105. This image forming apparatus can not easily cause faulty cleaning performance even in using the magnetic toner and the non-magnetic color toners in combination and has superior environmental stability and running stability even where toners made to have small particle diameter are used or process speed is high.

Abstract: A magnetic black toner comprising magnetic black toner particles containing at least a binder resin and a magnetic material. The toner has a weight-average particle diameter of from 5 &mgr;m to 12 &mgr;m, and the toner has, in its particles of 3 &mgr;m or more in diameter, at least 90% by number of particles with a circularity of 0.900 or more and has an average circularity of from 0.940 to 0.970. The magnetic material comprises iron oxide particles which have an average particle diameter of from 0.10 &mgr;m to 0.30 &mgr;m, contain titanium or a titanium compound in an amount of from 0.3% by weight to 1.5% by weight in terms of titanium, based on the total weight of the iron oxide particles, and have the ratio of the proportion of FeO to the total Fe content in 10% by weight from the particle surface, A %, to the proportion of FeO to the total Fe content in the remainder 90% by weight, B %, which satisfies the expression: 0.7≦A/B≦1.0.

Abstract: A toner contains at least a bonding resin and a coloring agent, and has a weight mean particle size from 5 &mgr;m to 12 &mgr;m; not less than 90% by number of particles not less than 3 &mgr;m have a circularity “a” not less than 0.900; a cut ratio Z and a weight mean size X of the toner are related as: cut ratio Z≦5.3×X; and a relationship of particles Y having a circularity of not less than 0.950 and a weight mean size X is Y≧e5.51×X−0.645 where X is 5 to 12 &mgr;m.

Abstract: A toner comprises toner particles comprising at least a binder resin, a colorant, and a sulfur-containing resin, in which the toner particles comprise the sulfur-containing resin so as to satisfy a relation of; 0.50≦IS/TS≦0.95 where TS denotes a content of sulfur in the toner particles, and IS denotes a content of sulfur in isopropyl alcohol insoluble components of the toner particles, whereby it is possible to obtain a high quality image having an excellent developing resistance regardless of the surrounding conditions and a uniform charge amount distribution regardless of processing speed.

Abstract: A toner containing toner particles and an inorganic fine powder; the toner particles containing at least a binder resin, a colorant, a sulfur-containing resin, and a wax; the binder resin containing a hybrid resin component containing a vinyl type polymer unit and a polyester unit, and the sulfur-containing resin being a resin selected from the group consisting of sulfur-containing polymers and sulfur-containing copolymers

Abstract: A magnetic black toner comprising magnetic black toner particles containing at least a binder resin and a magnetic material. The toner has a weight-average particle diameter of from 5 &mgr;m to 12 &mgr;m, and the toner has, in its particles of 3 &mgr;m or more in diameter, at least 90% by number of particles with a circularity of 0.900 or more and has an average circularity of from 0.940 to 0.970. The magnetic material comprises iron oxide particles which have an average particle diameter of from 0.10 &mgr;m to 0.30 &mgr;m, contain titanium or a titanium compound in an amount of from 0.3% by weight to 1.5% by weight in terms of titanium, based on the total weight of the iron oxide particles, and have the ratio of the proportion of FeO to the total Fe content in 10% by weight from the particle surface, A%, to the proportion of FeO to the total Fe content in the remainder 90% by weight, B%, which satisfies the expression: 0.7≦A/B≦1.0.

Abstract: A toner manufacturing method includes grinding and classification to produce a toner containing a binder resin and a colorant with a weight mean particle size of 5 microns to 12 microns and sharp particle density distribution. The toner has a specific circularity, relationship between cut ratio and weight mean size, and relationship between circularity and weight mean size as disclosed in the specification.

Abstract: A toner has toner particles containing at least a binder resin, a colorant and a sulfur-containing compound selected from the group consisting of a sulfur-containing polymer and a sulfur-containing copolymer. The toner has a weight-average particle diameter of from 5 &mgr;m to 12 &mgr;m, and the toner has, in its particles of 3 &mgr;m or larger in diameter, at least 90% by number of particles with a circularity of 0.900 or higher, and has a specific relationship between the cut rate Z and the toner weight-average particle diameter X and a specific relationship between the number-based cumulative value Y of particles with a circularity of 0.950 or higher and the toner weight-average particle diameter X. Also disclosed are an image-forming method and a process cartridge which make use of the toner.

Abstract: A toner contains at least a bonding resin and a coloring agent, and has the following characteristics (i) to (iv):

Abstract: A toner has toner particles containing at least a binder resin, a colorant and a sulfur-containing compound selected from the group consisting of a sulfur-containing polymer and a sulfur-containing copolymer. The toner has a weight-average particle diameter of from 5 &mgr;m to 12 &mgr;m, and the toner has, in its particles of 3 &mgr;m or larger in diameter, at least 90% by number of particles with a circularity of 0.900 or higher, and has a specific relationship between the cut rate Z and the toner weight-average particle diameter X and a specific relationship between the number-based cumulative value Y of particles with a circularity of 0.950 or higher and the toner weight-average particle diameter X. Also disclosed are an image-forming method and a process cartridge which make use of the toner.

Abstract: A toner containing toner particles and an inorganic fine powder; the toner particles containing at least a binder resin, a colorant, a sulfur-containing resin, and a wax; the binder resin containing a hybrid resin component containing a vinyl type polymer unit and a polyester unit, and the sulfur-containing resin being a resin selected from the group consisting of sulfur-containing polymers and sulfur-containing copolymers

Abstract: A toner having a negative triboelectric chargeability is constituted by at least a binder resin, a colorant and an organic metal compound. The toner is characterized by: (a) the organic metal compound is an organic zirconium compound comprising a coordination or/and a bonding of zirconium and an aromatic compound as a ligand or/and an acid source selected from the group consisting of aromatic diols, aromatic hydroxycarboxylic acids, aromatic monocarboxylic acids, and aromatic polycarboxylic acids, (b) the binder resin is a resin selected from the group consisting of (i) a polyester resin and (ii) a hybrid resin component comprising a polyester unit and a vinyl polymer unit, (c) the binder resin has an acid value of 2-50 mgKOH/g, and (d) the toner contains a TFT (tetrahydrofuran)-soluble content providing a GPC (gel permeation chromatography) chromatogram exhibiting a main peak in a molecular weight range of 3,000-20,000 and including 3-25% of a component having molecular weights of at least 5×105.

Abstract: An electrophotographic toner is composed of at least a binder resin, a colorant, and a wax. The binder resin (a) comprises a polyester resin, a vinyl resin and a hybrid resin component comprising a polyester unit and a vinyl polymer unit, (b) has a THF (tetrahydrofuran)-soluble content (W1) of 50-85 wt. % and a THF-insoluble content (W2) of 5-50 wt. %, an ethyl acetate-soluble content (W3) of 40-98 wt. % and an ethyl acetate-insoluble content (W4) of 2-60 wt. %, a chloroform-soluble content (W5) of 55-90 wt. % and a chloroform-insoluble content (W6) of 10-45 wt. %, respectively after 10 hours of Soxhlet extraction with respective solvents, giving a ratio W4/S6 of 1.1-4.0, and contains a THF-soluble content providing a GPC (gel permeation chromatography) chromatogram exhibiting a main peak in a molecular weight range of 4000-9000, including 35.0-65.0% (A1) of a component haing molecular weights in a range of 500 to below 1.times.10.sup.4, 25.0-45.0% (A2) of a component having molecular weights in a range of 1.