Abstract: A toner having a cohesion level of 50 or less when measured using an ASTM D 6393-99 includes a first agglomerated toner including latex particles for a core, a pigment and an inorganic salt, and latex particles for a shell layer coated on the first agglomerated toner, wherein the latex particles for the core and the latex particles for the shell layer are prepared by polymerizing a composition including an amphiphilic monomer having a hydrophilic group, a hydrophobic group and at least one reactive functional group, and a polymerizable monomer.

Abstract: 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.

Abstract: 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.

Abstract: Hollow toner and a process of preparing the same are provided. The hollow toner has a hollow sphere shape, wherein an outer layer surrounding the hollow sphere includes a polymer, a wax and a pigment. The hollow toner has excellent fixing properties under low energy and low pressure, and can be efficiently used at high-speed fixing. Also, a small amount of the hollow toner is consumed. Thus, the hollow toner can be efficiently applied to various apparatuses of forming an image such as a two-component low-temperature printer and super high-speed printer, and the hollow toner can be prepared by using a relatively simple process.

Abstract: A method for preparing latex for a toner includes heating a mixture of distilled deionized water and poly (ethylene glycol)-ethyl ether methacrylate (PEG-EEM) with stirring, adding a monomer mixture, 1-dodecanethiol and an ester wax to the mixture, dispersing the mixture with ultrasonic vibration, adding potassium persulfate (KPS) to the dispersion and allowing to react for 4 to 6 hours, and allowing the reaction mixture to cool with stirring. The dry toner prepared by the method enables easy control over the molecular weight of latex, has superior durability and excellent low-temperature fixation, contains a small amount of wastewater and is composed of small-diameter particles, thus being suitable for use in high-definition printers.

Abstract: A method of preparing toner, the method including preparing a latex for a core by polymerizing a composition for a core including a macromonomer having a hydrophilic group, a hydrophobic group and at least one reactive functional group, at least one polymerizable monomer, and a wax; agglomerating the latex for a core by adding a pigment dispersion dispersed by the macromonomer and an inorganic salt to the prepared latex for a core; and coating the agglomerated latex for a core using a latex for a shell layer, wherein the latex for a shell layer is prepared by polymerizing a composition for a shell layer including at least one polymerizable monomer, a macroinitiator having polydimethyl siloxane units, and a macromonomer, and toner prepared according to the method.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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° 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.

Abstract: A method of preparing a toner, a toner prepared using the method, an image forming method using the toner, and an image forming apparatus containing the toner are provided. The method of preparing toner includes providing a toner composition including a polyester-macromonomer having double bonds at the ends of a molecular chain of a polyester, at least one polymerizable monomer, and a pigment, providing a stabilizer dispersion by mixing a dispersion medium and a stabilizer, and then mixing the obtained stabilizer dispersion with the toner composition to form droplets, and heat-treating the droplets to polymerize the mixture. The method of preparing the toner according to the present invention provides a toner having excellent properties of both a polyester-based monomer and a vinyl-based monomer and excellent gloss, durability, low-temperature fusing property, and stability and may be used to easily control types and sizes of the toner.

Abstract: A toner preparation method is provided including: polymerizing a toner composition including a polyester-macromonomer having double bonds at the molecular chain ends and at least one polymerizable monomer to prepare a polymer latex; and mixing the polymer latex with a dispersed pigment solution obtained by dispersing a pigment in a macromonomer having both a hydrophilic group and a hydrophobic group and containing at least one reactive functional group and agglomerating the polymer latex in the presence of an inorganic salt, and a toner prepared using the toner preparation method. The toner has excellent properties of both a polyester-based monomer and a vinyl-based monomer and excellent gloss, durability, low-temperature fixing property, and storage stability, and the shape and size of the toner can be easily controlled.

Abstract: An electrophotographic photoreceptor containing a naphthalenetetracarboxylic acid diimide derivative of Formula (1), which has a branched alkyl group substituted with an aryl group at the ?-position with regard to nitrogen atoms of imide groups: wherein R1 and R2 are independently selected from the group consisting of a hydrogen atom, a halogen atom, a C1-C20 substituted or unsubstituted alkyl group, and a C1-C20 substituted or unsubstituted alkoxy group; R3 is selected from the group consisting of a C1-C20 substituted or unsubstituted alkyl group, a C1-C20 substituted or unsubstituted alkoxy group, a C7-C30 substituted or unsubstituted aralkyl group, and a group having the formula —(CH2)n—Y—R4; Ar is a C6-C30 substituted or unsubstituted aryl group; Y is an oxygen or sulfur atom; R4 is a hydrogen atom or a C1-C20 substituted or unsubstituted alkyl group; and n is an integer between 1 and 12.

Abstract: 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.

Abstract: A hybrid toner and a method of preparing the toner are provided. The hybrid toner is of a core-shell type, and as such the storage characteristics of the toner are improved and a toner blocking phenomenon and image contamination that are caused by dispersion of waxes or colorants onto the surface of the outer layer of toner particles are prevented. The hybrid toner includes particles include: 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 a shell of 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.

Abstract: A method of preparing toner includes: preparing a primary latex 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; preparing a primary agglomerated toner by mixing the primary latex with a pigment dispersion dispersed by the macromonomer and adding an inorganic salt to the mixture; and coating the primary agglomerated toner using a secondary latex including a core formed by polymerizing the macromonomer and at least one polymerizable monomer, a wax layer formed on the core by applying a dispersion in which at least one polymerizable monomer is dispersed in a wax, and a shell layer formed on the wax layer by adding at least one polymerizable monomer to the wax layer. A toner prepared by the method is also provided.

Abstract: 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 (?) of about 4.0×101 Pa·s to about 1.6×103 Pa·s at a temperature ranging from about 40° C. lower than a toner fixing temperature to about 10° 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.

Abstract: A preparation method of a toner having a micro diameter includes: blending a monomer and a dispersing agent in distilled water to prepare a monomer dispersion; polymerizing the monomer dispersion by adding a first polymerization initiator to about 1% by volume to about 50% by volume of the monomer, to cause a first polymerization; mixing the remaining monomer dispersion with the polymerized solution; and polymerizing the mixed solution by adding a wax emulsion and a second polymerization initiator, to cause a second polymerization. The present invention may be advantageously used for obtaining spherical, uniformly micro sized toner particles through the emulsion polymerization only, without performing the aggregation or melting process.

Abstract: A liquid toner composition and a preparation method utilize a colorant, an organosol, a charge control agent, a carrier liquid, a dispersion assistant agent, and a photoreactive catalyst, in which the dispersion assistant agent is a polymer including an unsaturated functional group to cause photopolymerization in a presence of the photoreactive catalyst, and the photoreactive catalyst produces a free radical through an irradiation of light, and initiates the photopolymerization of the dispersion assistant agent. According to embodiments of the present invention, the toner organosol rarely affects the physical properties required of the liquid toner, and an offset error in a fixing operation is removed, resulting in an improved quality of a printed image.

Abstract: A method of preparing toner includes preparing a pigment dispersion solution by dispersing a pigment in a mixed surfactant solution composed of an anionic reactive surfactant and a nonionic reactive surfactant, mixing the pigment dispersion solution with a polymer latex prepared by polymerizing a toner composition comprising an amphiphilic macromonomer having at least one reactive functional group at an end thereof and at least one polymerizable monomer, and adding an inorganic salt to a mixed solution of the polymer latex and the pigment dispersion solution to be agglomerated, wherein a shape of toner particles can be controlled to have circularity of 0.5-1.0 by adjusting an amount of the nonionic reactive surfactant to be 20-100 parts by weight based on 100 parts by weight of the anionic reactive surfactant. In addition, a method of forming an image uses the toner, and an image forming apparatus to form an image employs the toner.