Canon Kabushiki Kaisha

Makoto Unno

Masaaki Taya

Yasutaka Akashi

Masaki Uchiyama

Hirohide Tanikawa

Yushi Mikuriya

Tadashi Doujo

Takaaki Kohtaki

Takaaki Kotaki

Yoshinobu Joh

Tadashi Dojyo

Manabu Ohno

Koichi Tomiyama

Shunji Suzuki

Nobuyuki Okubo

Makoto Kanbayashi

Kiichiro Sakashita

Kazuyoshi Hagiwara

Seiichi Takagi

Takayuki Nagatsuka

Takeshi Ohtake

Yoshinobu Jo

A toner for electrostatic imaging has a vinyl resin binder with an acid value of 2.5-70 mgKOH/g and (i) a long-chain alcohol with an OH value of 10-120 mg/KOH/g or (ii) a long-chain alkyl carboxylic acid with an acid value of 5-120 mg/KOH/g, wherein the acid value of the resin binder&plus;either (i) OH value of the alcohol or (ii) acid value of the acid>(&frac14;)&times;OH value of the binder.

Toner for developing electrostatic image

Toner for developing electrostatic image, image forming method and process cartridge

A toner having a negative triboelectric chargeability and suitable for developing positively or negatively charged images is composed of at least a binder resin, a colorant and an organic metal compound. 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.

Toner having negative triboelectric chargeability and developing method

A toner for developing electrostatic images includes a binder resin, a specific long-chain alkyl compound and a specific azo iron complex. The long-chain alkyl compound contains a terminal --OH or --COOH group and from about 35 to 150 (--CH.sub.2 --) groups. The azo iron complex has a cation including 75-98 mol. % of ammonium ion and another ion which is hydrogen, sodium, potassium or mixtures thereof.

Toner for developing electrostatic image, image forming method and

The toner for developing an electrostatic image has toner particles containing at least binder resin and colorant. The resin components of a range of 2,000 to 100,000 in molecular weight, prepared by preparatory liquid chromatograph from the binder resin, exhibit an M/S ratio of 200 or greater and are 50% to 90% in abundance. The M and S stand for a weight average molecular weight (M) measured by means of light scattering method and an inertia radius (S) measured by means of light scattering method, respectively.

Toner for developing an electrostatic image

A toner for developing electrostatic images is formed of toner particles comprising a binder resin and a colorant, and inorganic fine powder. The toner further contains: a phenol-aldehyde condensate mixture comprising an acyclic condensate and a cyclic condensate, respectively, of a phenol compound with an aldehyde compound, and the phenol-aldehyde condensate mixture contains 10-80 mol % of condensate components having 4-6 phenolic units. The phenol-aldehyde condensate mixture may be contained in or externally added to the toner particles. Because of the inclusion of an acyclic condensate and appropriate amount of condensate components having 4-6 phenolic units, the phenol-aldehyde condensate mixture may exhibit a good dispersibility in the binder resin and a good charge control performance.

Toner for developing electrostatic images

A toner for developing an electrostatic image is constituted by a resin composition and a colorant. The resin composition includes a high-softening point polyester resin (I) having a softening point of 120.degree.-180.degree. C. a low-softening point polyester resin (II) having a softening point of 80.degree.-120.degree. C., and a long-chain alkyl compound selected from the group consisting of-a long-chain alkyl alcohol principally comprising long-chain alkyl alcohol components having long-chain alkyl groups of 23 to 252 carbon atoms and a long-chain alkyl carboxylic acid principally comprising long-chain alkyl carboxylic acid components having long-chain alkyl groups of 22 to 251 carbon atoms. The resin composition preferably includes a tetrahydrofuran (THF)-soluble content providing a gel permeation chromatogram showing a weight-average molecular weight (Mw) of at least 10.sup.5, a ratio of Mw to number-average molecular weight (Mn) of at least 35 and an areal percentage of at least 5% of a region of molecular weight of at least 2.times.10.sup.5.

A magnetic toner composed of a binder resin and magnetic fine particles, wherein the magnetic fine particles are coated with an iron-zinc oxide on their surfaces and the magnetic fine particles have a saturation magnetization (.sigma.s) of 50 Am.sup.2 /kg or above under a magnetic field of 79.58 kA/m (1K oersted) where the product of residual magnetization (.sigma.r, Am.sup.2 /kg) and coercive force (Hc, kA/m), .sigma.r.times.Hc, is in the range between 60 and 250 (kA.sup.2 m/kg).

Magnetic toner and image forming method

A toner for developing electrostatic images comprises, (i) a binder resin, (ii) a colorant, and (iii) a compound made by a reaction of a monohydroxylic compound having a long-chain alkyl group having an alkylene group with 40 or more carbon atoms and a hydroxyl group with a carboxylic acid having a molecular weight of 1,000 or less, or a compound made by a reaction of a monocarboxylic compound having a long-chain alkyl group having an alkylene group with 40 or more carbon atoms and a carboxyl group with an alcohol having a molecular weight of 1,000 or less.

Toner for developing electrostatic images, image forming method and

A toner for developing an electrostatic image is constituted by a binder resin and a colorant. The toner is characterized by a percentage change .sub.G' of at most 50% as calculated by the following formula (1):

A toner for developing an electrostatic image has a binder resin and a colorant. The binder resin contains a polyester resin at least part of which has a long-chain alkyl group having 22 to carbon atoms and has a hydroxyl group or a carboxyl group at its terminal.

Toner for developing electrostatic image, one component-type developer

An image forming method in which a toner-carrying member for carrying a specific magnetic toner is placed adjacent a latent image-bearing member for carrying an electrostatic latent image so as to form a developing region of a predetermined gap size. The magnetic toner on the toner-carrying member forms a toner layer of a regulated thickness smaller than the above-mentioned gap. An asymmetric bias is applied to the magnetic toner so as to cause the magnetic toner from the toner-carrying member to be conveyed to the latent image-bearing member thereby to develop the electrostatic latent image.

Magnetic toner having defined particle distribution

A toner for developing an electrostatic image is constituted by a binder resin and a colorant The binder resin is characterized by containing at least 20 wt. % of an extraction residue after 6 hours of extraction and below 20 wt. % of an extraction residue after 72 hours of extraction respectively by Soxhlet extraction with tetrahydrofuran. The toner shows a dynamic modulus and a loss modulus, respectively at 200.degree. C. and 0.1 Hz, which are substantially unchanging with time. The properties provide the toner with a harmonization of anti-offset characteristic and fixability as well as stable viscoelasticity under heating.

Toner for developing electrostatic image and fixing method

An image forming apparatus and a process cartridge includes a toner for developing an electrostatic image that is constituted by at least a binder resin and a charge control agent. The binder resin has an acid value of 5-50. The charge control agent includes an iron complex represented by the following formula: ##STR1## wherein X.sub.1 and X.sub.2 independently denote hydrogen atom, lower alkyl group, lower alkoxy group, nitro group or halogen atom; m and m' denote an integer of 1-3; R.sub.1 and R.sub.3 independently denote hydrogen atom, C.sub.1-18 alkyl or alkenyl, sufonamide, mesyl, sulfonic acid group, carboxy ester group, hydroxy, C.sub.1-18 alkoxy, acetylamino, benzoylamino or halogen atom; n and n' denote an integer of 1-3; R.sub.2 and R.sub.4 denote hydrogen atom or nitro group; and A.sup.+ denotes hydrogen ion, sodium ion, potassium ion or ammonium ion. The toner has a weight-average particle size (D.sub.4) of 4-9 .mu.m and including toner particles having a particle size of 5 .mu.m or smaller at 3-90% by number, toner particles having a particle size of 6.35-10.08 .mu.m at 1-80% by number and toner particles having a particle size of 12.7 .mu.m or larger at a percentage by volume of at most 2.0%, wherein the toner particles having a particle size of 5.0 .mu.m or smaller are contained at N % by number and at V % by volume satisfying a relationship:

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Makoto Unno