Samsung Electronics Co., Ltd.

Kyung-yol Yon

Saburo Yokota

Hwan-koo Lee

Beom-jun Kim

Hae-ree Joo

Min-Young Cheong

Seung-ju Kim

Jun-Young Lee

Nam-jeong Lee

Nam-Jeong Lee

Ki-won Seok

Joong-Hwan Choi

Chang-kook Hong

Ji-Young Lee

Moto Makino

In Gun Kim

Sang-woo Kim

Jeong-hun Pang

Jung-wook Kim

Jae-hyeuk Jeong

Boom-jun Kim

Deuck-Woo Jang

Young-ho Lee

Kyeong Pang

Yong-baek Yoo

Kwang-ho No

Sang-deok Kim

Yo-Da Shin

Young-ha No

Ji-uk Kim

Seong-joon Chae

Seong-geun Oh

Yoda Shin

Boem-jun Kim

Tac-hoe Koo

Beam-Jun Kim

Beom-Jun Kim

Sang-eun Shim

An electrophotographic toner includes a latex, a coloring agent, a wax and 3 to 1,000 ppm of each of Si and Fe, wherein a mole ratio of Si to Fe is from 0.1 to 5.

Electrophotographic toner and method of preparing the same

A toner includes a core containing a binder resin, wax, and a colorant, and an external additive layer coating the core, wherein the core is prepared such that it is extruded and extended to have a fiber phase, and is pulverized. The toner has an improved fixing ability to allow an electrostatic image to be fixed at a low temperature while having an excellent durability and an improved storage stability, while exhibiting reduced toner blocking and offset phenomena.

Toner and process of preparing the same

A hybrid toner includes micro cylinders, cores inserted into the micro cylinders, and an external addition layer covering the micro cylinders to which the cores are inserted. The hybrid toner prevents a toner blocking phenomenon, image contamination, and low storage stability which occur due to dispersion of wax and colorants to an outer surface of the toner.

Hybrid toner and method of preparing the same

A toner for electrophotography is provided including a binder resin, a colorant, a charge control agent, and a release agent, wherein a glass transition temperature (Tg) is over 55&#xb0; C., a molecular weight distribution (MWD) is in the range of about 4.5 to 5.5 when a weight average molecular weight is in the range of about 45,000 to 55,000, and a compression elastic modulus is about 750 MPa or higher at room temperature. Mechanical properties of toner can be obtained at room temperature by controlling rheological properties of toner. The developing properties and fixing properties of toner for electrophotography can be improved by lowering viscosity at a high temperature, and thus image quality can be stabilized.

Toner for electrophotography

A hybrid toner and a method of preparing the toner are provided. The hybrid toner is of a core-shell type having improved storage characteristics and a toner blocking phenomenon. The toner prevents image contamination caused by dispersion of waxes or colorants onto the surface of the outer layer of toner particles are prevented. The hybrid toner includes particles including: a core of about 100 parts by weight of a polyester-based resin, about 1-20 parts by weight of a wax, about 0.1-10 parts by weight of a colorant and about 0.1-10 parts by weight of a charge control agent; and about 5-500 parts by weight of a vinyl-based resin, about 0.1-10 parts by weight of silica, about 0.1-5 parts by weight of a metal oxide and about 0.1-10 parts by weight of polymer beads.

A toner for electrophotography is provided that includes a binder resin, a colorant, a charge control agent, and a releasing agent, wherein the toner has a complex viscosity (&#x3b7;) of about 4.0&#xd7;10Pa&#xb7;s to about 1.6&#xd7;10Pa&#xb7;s at a temperature ranging from about 40&#xb0; C. lower than a toner fixing temperature to about 10&#xb0; C. higher than the toner fixing temperature and has a specified activation energy of 15 to 85 KJ/mol. By defining viscosity dependency in a linear modulus region of a toner and comprehensively defining thermal and rheological properties with respect to fixing conditions, a fixing phenomenon can be generalized and the quality of a toner can be evaluated.

A method of preparing a toner, includes: preparing a core by mixing a polyester resin and a colorant with at least one material selected from the group consisting of a macromonomer having hydrophilic group, hydrophobic group, and at least one reactive functional group and a reactive emulsifying agent. A shell is formed on the core by polymerizing the exterior surface of the core with one or more polymerizable monomers and an initiator, wherein at least one material selected from the group consisting of the macromonomer and the reactive emulsifying agent participate in the polymerization reaction. Also, provided are a toner prepared using the method, an image forming method using the toner, and an image forming apparatus employing the toner. According to the method, a polyester resin, having superior fixability at low temperature and image properties, is used as a core composition and styrene, having superior maintenance and charging properties, is used as a shell composition in the process of manufacturing a core/shell structure to prepare the toner for the image forming apparatus having fast speed and fixability of high quality images at low temperature. In addition, by not using the reactive emulsifying agent, the cleaning process is minimized, and the amounts of polluted water and waste water are decreased, which is very advantageous environmentally.

Method of preparing core-shell toner and toner prepared using the method

A method of preparing a toner includes: preparing a toner composition including a macromonomer having a hydrophilic group, a hydrophobic group and at least one reactive functional group, at least one polymerizable monomer, and a colorant; emulsion-polymerizing the toner composition in a medium; and separating and drying the polymerized toner. A toner is prepared using the method. An image forming method using the toner, and an image forming apparatus using the toner are also provided. According to the method, the size, distribution and configuration of toner particles are easily controlled. In addition, the method does not involve the use of or minimizes the use of a surfactant, and decreases polluted water and waste water, which is very advantageous environmentally.

Method of preparing toner and toner prepared using the method

A method of preparing a toner, includes: preparing a high molecular weight latex particle by polymerizing a toner composition including a macromonomer having a hydrophilic group, a hydrophobic group and at least one reactive functional group, and at least one polymerizable monomer; forming a core particle by aggregating the high molecular weight latex particle; forming a shell layer by coating the core particle using a polymer having a higher glass transition temperature than a glass transition temperature of the core particle. Also, provided are a toner prepared using the method, an image forming method using the toner, and an image forming apparatus using the toner. Using the toner, an image can be fused at a low temperature. Also, durability of the toner is improved.

A method of preparing a toner, including: preparing a colorant dispersion by mixing a reactive emulsifier and a colorant; preparing a toner composition by mixing a macromonomer including a hydrophilic group, a hydrophobic group and at least one reactive functional group, at least one polymerizable monomer and a chain transfer agent with the colorant dispersion; emulsion polymerizing the toner composition in a medium; and separating and drying the polymerized toner, wherein the amounts of the macromonomer and the chain transfer agent are controlled to regulate the configuration of toner particles. A toner prepared using the method, an image forming method using the toner, and an image forming apparatus using the toner are also provided by the invention. According to the method, the size and configuration of toner particles are easily controlled. In addition, the method minimizes the use of a surfactant, and decreases polluted water and waste water, which is very advantageous environmentally.

A method of preparing a toner includes: preparing high molecular weight latex particles by polymerizing a toner composition including a macromonomer having a hydrophilic group, a hydrophobic group and at least one reactive functional group, at least one polymerizable monomer, a colorant and wax; aggregating the high molecular latex particles in the absence of an emulsifier, a colorant, and wax; and separating and drying the aggregated high molecular weight latex particles. A toner is prepared using the method described above. An image forming method using the toner and an image forming apparatus employing the toner are also provided. Using the method described above, polymerizable toner particles can be prepared using a simplified process and the colorant and was inside the toner can be easily dispersed.

An electrophotographic photoreceptor and an electrophotographic imaging apparatus include an asymmetric naphthalenetetracarboxylic acid diimide derivative. The asymmetric naphthalenetetracarboxylic acid diimide derivative has increased solubility in organic solvents and improved compatibility with binder resins, thus providing excellent electron transporting ability. The electrophotographic photoreceptor containing the asymmetric naphthalenetetracarboxylic acid diimide compound according to the present invention can maintain a constant surface potential after being repeatedly used for an extended time. The electrophotographic photoreceptor according to the present invention can provide a high image quality for an extended time.

Electrophotographic photoreceptor containing asymmetric naphthalenetetracarboxylic acid diimide derivatives and electrophotographic imaging apparatus employing the same

A two-layered electrophotographic photoreceptor is formed. The two-layered electrophotographic photoreceptor includes an electrically conductive substrate and a charge generating layer and a charge transporting layer form on the electrically conductive substrate, wherein the charge generating layer is a naphthalenetetracarboxylic acid diimide derivative represented by:  The two-layered electrophotographic photoreceptor has high photosensitivity and low residual potential.

Electrophotographic photoreceptor containing naphthalenetetracarboxylic acid diimide derivatives as electron transport materials in charge generating layer and the electrophotographic imaging apparatus using the photoreceptor

An electrophotographic photoreceptor is provided containing a specific asymmetric naphthalenetetracarboxylic acid diimide derivative having a nitro group. An electrophotographic imaging apparatus, an electrophotographic cartridge, and an electrophotographic drum employing the electrophotographic photoreceptor are also provided. The naphthalenetetracarboxylic acid diimide derivative has high solubility in an organic solvent, compatibility with a binder resin, and electron transporting ability. The electrophotographic photoreceptor manufactured using the naphthalenetetracarboxylic acid diimide derivatives has an excellent electrostatic property.

Electrophotographic photoreceptor containing asymmetrical naphthalenetetracarboxylic acid diimide derivatives and electrophotographic imaging apparatus employing the photoreceptor

An electrophotographic photoreceptor including: an electrically conductive substrate; a charge generating layer disposed on the electrically conductive substrate and includes a charge generating material dispersed or dissolved in a binder resin and an asymmetric naphthalenetetracarboxylic acid diimide derivative having a nitro group dispersed or dissolved in the binder resin. The photoreceptor also has a charge transporting layer that is disposed on the charge generating layer and includes a charge transporting material that is dispersed or dissolved in the binder resin. An electrophotographic image forming apparatus including the electrophotographic photoreceptor. The two-layered type electrophotographic photoreceptor has good interlayer adhesive force and good electrical properties such as good photosensitivity and low residual potential after exposure.

Electrophotographic photoreceptor containing asymmetrical naphthalenetetracarboxylic acid diimide derivative as electron transporting material in a charge generating layer and electrophotographic image forming apparatus employing the photoreceptor

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Seongnam-si, South Korea

Kyung-yol Yon