Konica Minolta, Inc.

Konica Minolta Business Technologies, Inc.

Hitomi Motani

Tomomi Oshiba

Tomoko Mine

Saburou Hiraoka

Tatsuya Nagase

Kaori Matsushima

Mikihiko Sukeno

Ken Ohmura

Kosuke Nakamura

Ryuichi Hiramoto

Hiroyuki Kozuru

Yoshiyasu Matsumoto

Yasuko Uchino

Ito Koga

Kishio Tamura

Takanari Kayamori

Hideya Miwa

Takayuki Ishikawa

In an image forming method, a black toner and a color toner other than the black toner are used. The black toner and the color toner each include a binder resin including a polyester resin as a main component and a vinyl resin, a releasing agent, and an external additive. A content Vk % by mass of the vinyl resin relative to total mass of the binder resin included in the black toner, a content Vc % by mass of the vinyl resin relative to total mass of the binder resin included in the color toner, a content Wk % by mass of the releasing agent relative to the total mass of the binder resin included in the black toner, and a content Wc % by mass of the releasing agent relative to the total mass of the binder resin included in the color toner satisfy a specific relationship.

Image forming method and toner set for developing electrostatic latent image

An image forming method uses a color toner including a yellow toner, a magenta toner, a cyan toner, and a black toner. The image forming method includes a toner image forming step of forming a toner image by developing the color toner on an electrostatic latent image formed by charging and exposing a surface of an electrostatic latent image bearing member, a transfer step of transferring the toner image onto a recording medium to form a color toner image, and a fixing step of fixing the color toner image on the recording medium. Each toner contain at least a binder resin, a coloring agent, a release agent, and a layered silicate compound. The volume average particle diameter of each toner is 4 to 6 &#x3bc;m. The content of the aluminum element in each toner represented by the Net intensity by WDXRF analysis has a specific relationship.

The present invention addresses at least the problem of providing a method for forming a high-resolution foil image regardless of the hydrophilicity of a recording medium. In order to solve said problem, the present invention provides a method wherein an adhesive ink that is formed by dispersing or dissolving a polymer resin in water and in a water-soluble organic solvent is used as an adhesive for a foil, the adhesive is applied by means of inkjet printing, and a foil image is formed. The polymer resin of the adhesive ink is a polymer of a monomer that includes (meth)acrylic acid and a (meth)acrylic acid alkyl ester having a Calkyl group, the acid value of the polymer resin being 50-120 mg KOH/g, and the glass transition temperature of the polymer resin being 30-110&#xb0; C.

Foil image formation method

It is an object to suppress yellowing of a binder resin while obtaining an image with a high degree of whiteness and to suppress occurrence of image defects when printing at a high temperature and a high humidity. A toner for developing an electrostatic image, the toner including: white toner base particles containing a binder resin and titanium oxide having an average particle size of from 130 to 600 nm; and an external additive including strontium titanate.

Toner for developing electrostatic image

Disclosed are a toner for electrostatic image development and an image formation process using the same which can achieve high varnish application property and high adhesion of a heat-fixed image to a varnish layer even when the varnish layer is formed on the fixed image formed by an image formation process of an electrophotographic system. The toner for electrostatic image development includes toner particles containing at least a binder resin, a colorant and a parting agent, and the binder resin contains a polyfunctional acrylate-modified polyester resin obtained by modification with a polyfunctional acrylate compound. In the toner for electrostatic image development, it is preferable that the toner particles have a core-shell structure, in which the surface of a core particle is coated with a shell layer, and the polyfunctional acrylate-modified polyester resin is contained in the shell layer.

Toner for electrostatic image development, two-component developer, and image formation process

The production process is a process for producing a toner for electrostatic image development. The process has an aggregating step of adding an aggregating agent composed of a compound having a divalent or trivalent metal element into a dispersion with fine particles of a binder resin dispersed in an aqueous medium, and an aggregation terminating step of adding an aggregation terminating agent into the dispersion. The aggregation terminating agent is composed of a compound having at least one of a structure (1) represented by a formula (1) and a structure (2) represented by a formula (2). In the formulae (1) and (2), Rto Reach independently represent a hydrogen atom, a hydroxy group or an organic group. At least one of Rand Ror at least one of Rand Rrepresents a hydroxy group. 

Production process of toner for electrostatic image development

The toner for electrostatic image development has excellent charge properties, by which excellent toner particle size-controlling ability is achieved, and moreover the sharpening of a particle size distribution is achieved. The toner is composed of toner particles containing a binder resin. The process has an aggregating step of adding an aggregating agent containing a transition element into an aqueous medium of dispersed fine binder resin particles to aggregate the fine binder resin particles, and an aggregation-stopping step of adding an aggregation stopper composed on a sulfur atom-containing compound exhibiting a reducing action on the aggregating agent. The aggregating agent is a salt of a bivalent or higher metal selected from Sr, Ti, V, Cr, Mn, Fe, Co, Ni and Cu.

The present invention relates to a two-component developer which comprises a toner, and a carrier having a surface of a core material particle coated with a resin having a unit of general formula (1). The present invention provides a two-component developer which has enhanced environmental stability of carrier charging performance.

Two-component developer

A two-component developer is disclosed, composing a toner comprising parent toner particles with an attached external additive and a carrier provided with a resin covering layer on a surface of a core particle, wherein the resin covering layer comprises a binder resin comprising an acrylic resin and when the resin covering layer is divided in half to a core particle side and a surface side, a nitrogen element content of the core particle side is larger than a nitrogen element content of the surface side.

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Tokyo, Japan

Hitomi Motani