Abstract:
L'invention concerne un matériau superparamagnétique constitué d'agrégats micrométriques friables de particules nanométriques, ledit matériau étant un oxyde de fer ou un oxyde mixte de fer, son procédé de préparation et ses utilisations.
Abstract:
The present invention relates to a magnetic toner composition, and more particularly to a magnetic toner composition having an improved chargeability and excellent uniform chargeability, and that is capable of reducing a difference in electrostatic charge between a toner remaining in a cartridge or in a developing unit and that of a newly supplied toner. A magnetic toner composition of the present invention comprises magnetic toner particulate comprising a binder resin and a magnetic substance, a conductive fine powder having a specific surface area of 30 to 300 m /g, a hydrophobic silica having a specific surface area of 100 to 240m /g, and an inorganic fine powder having an average diameter of 0.1 to 4.Oµm.
Abstract:
A process for preparing a powder coated with a multilayer film by coating the surface of a powder of a metal or a metal oxide as a substrate with a plurality of layers of a metal oxide, wherein the metal oxide layer or the like is formed by decomposition of a metal salt as an inexpensive starting material. For this process, the decomposition or the like of a metal salt under the conditions producing an acid or the like as a by-product is conducted so that powder particles are not attacked by the acid or the like. The coated powder is characterized in that at least one layer is formed of a metal hydroxide or a metal oxide formed by the hydrolysis of a metal alkoxide and that a layer overlying the metal hydroxide or metal oxide layer(s) is a coating layer formed of a metal hydroxide or a metal oxide formed by a reaction of a metal salt, for example, neutralization or heat decomposition. The heat treatment of the metal hydroxide layer or the metal oxide layer formed by the hydrolysis of a metal alkoxide causes the layer to be converted to a dense metal oxide layer.
Abstract:
Wax dispersion and domain size can be effectively controlled by Incorporating a small amount of a hybrid resin binder and or a wax compatibilizer in the toner formulation. Such toners show smaller wax domain size and improved fusing offset window, fusegrade and filming resistance, and therefore improved print quality and reliability. The hybrid resin contains a polyester unit via condensation reaction and a vinyl-based polymer unit via radical polymerization. The hybrid resin is highly compatible with the polyester resin binder, and at same time, can well accommodate low molecular weight polyolefin waxes in the vinyl polymer entity enabling a desirable smaller wax domain size. The wax compatibilizer is a themoplastic styrenic block copolymer.
Abstract:
A magnetic toner comprising a toner particle containing a styrene resin as a binder resin and a magnetic substance, and a first inorganic fine particle on surface of the toner particle and an organic-inorganic composite fine particle on the surface of the toner particle, wherein the first inorganic fine particle i) contains at least one inorganic oxide fine particle selected from the group consisting of silica fine particle, titanium oxide fine particle and alumina fine particle, with the proviso that the inorganic oxide fine particle contains silica fine particle in an amount of 85 mass% or more based on the total mass of the inorganic oxide fine particle, and ii) has a number-average particle diameter (D1) of 5 nm or more and 25 nm or less, the coverage ratio A of the toner-particle surface with the first inorganic fine particle is 45.0% or more and 70.0% or less.
Abstract:
A magnetic toner includes: magnetic toner particles containing a binder resin and a magnetic body; and inorganic fine particles that are present on the surface of the magnetic toner particles and are not a magnetic iron oxide and magnetic iron oxide particles that are present on the surface of the magnetic toner particles, wherein the inorganic fine particles present on the surface of the magnetic toner particles contain metal oxide fine particles, the metal oxide fine particles containing silica fine particles, and optionally containing titania fine particles and alumina fine particles, and a content of the silica fine particles being at least 85 mass% with respect to a total mass of the silica fine particles, the titania fine particles and the alumina fine particles; when a coverage ratio A(%) is a coverage ratio of the magnetic toner particles' surface by the inorganic fine particles and a coverage ratio B(%) is a coverage ratio of the magnetic toner particles' surface by the inorganic fine particles that are fixed to the magnetic toner particles' surface, the coverage ratio A and B/A satisfy prescribed ranges; and the magnetic iron oxide particles present on the magnetic toner particles' surface are from at least 0.10 mass% to not more than 5.00 mass% with respect to the total amount of the magnetic toner.
Abstract:
The magnetic toner contains magnetic toner particles containing a binder resin and a magnetic body, and inorganic fine particles present on the surface of the magnetic toner particles, wherein the inorganic fine particles present on the surface of the magnetic toner particles comprise metal oxide fine particles, wherein the metal oxide fine particles containing silica fine particles, and a content of the silica fine particles being at least 85 mass% with respect to a total mass of the metal oxide fine particles. In addition, the coverage ratio of the magnetic toner particle surface by the inorganic fine particles resides in a prescribed range for this magnetic toner; the binder resin is a styrene resin; the weight-average molecular weight and radius of gyration of the magnetic toner reside in a prescribed relationship; and the viscosity of the magnetic toner at 110℃ resides in a prescribed range.
Abstract:
A compound that includes an aqueous dispersion, wherein the dispersion includes a thermoplastic resin and at least one stabilizing agent,' and at least one selected from the group consisting of a colorant and a magnetic pigment, wherein the dispersion has an average volume diameter particle size from about 0.05 to about 10 microns is described.