Abstract: Flaky alumina particles including mullite in a surface layer of the flaky alumina particles. A method for producing flaky alumina particles including forming a mixture by mixing together an aluminum compound that contains elemental aluminum, a molybdenum compound that contains elemental molybdenum, and silicon or a silicon compound that contains elemental silicon, the aluminum compound being in an amount greater than or equal to 50 mass %, calculated as Al2O3, the molybdenum compound being in an amount less than or equal to 40 mass %, calculated as MoO3, the silicon or the silicon compound being in an amount of 0.5 mass % or greater and less than 10 mass %, calculated as SiO2, relative to a total mass of the flaky alumina particles taken as 100 mass %; and firing the mixture.

Abstract: To provide plate-like alumina particles that are less likely to wear apparatuses. Plate-like alumina particles containing germanium or a germanium compound. The plate-like alumina particles preferably have a molar ratio of Ge to Al, [Ge]/[Al], of 0.08 or more as determined in an XPS analysis. The plate-like alumina particles preferably contain the germanium or germanium compound in a surface layer. The plate-like alumina particles preferably have a density of 3.7 g/cm3 or more and 4.1 g/cm3 or less. The plate-like alumina particles preferably have a molar ratio of Ge to Al, [Ge]/[Al], of 0.08 or less as determined in an XRF analysis.

Abstract: The present invention provides alumina particles having a fixed card-house structure formed of three or more flat plate-like alumina particles and having an average particle diameter of 3 to 1000 ?m. Also, there is provided alumina particles having an average particle diameter of 3 to 1000 ?m and having a fixed card-house structure in which the three or more flat plate-like alumina are aggregated to be crossed each other at two or more plurality of positions, and the plane directions of the flat plates crossed each other are in a state of disordered arrangement.

Abstract: Provided is a surface-treated spinel particle (B) including a spinel particle (A) including a magnesium atom, an aluminum atom, and an oxygen atom and a surface treatment layer disposed at least a portion of the surface of the spinel particle (A). The surface treatment layer includes a surface-treating agent including an organic compound or a cured product of the surface-treating agent. The spinel particle (A) further includes molybdenum. The crystallite diameter of the [111] plane of the spinel particle (A) is 220 nm or more. Also provided are a method for producing the surface-treated spinel particle (B), a resin composition including the surface-treated spinel particle (B), and a molded article.

Abstract: A spinel compound oxide particle includes metallic atoms, aluminum atoms, oxygen atoms, and molybdenum atoms, wherein the metallic atoms are selected from the group consisting of zinc atoms, cobalt atoms, and strontium atoms, and a crystallite size in a [111] plane is 100 nm or more. Included are a step (1) of firing a first mixture including a molybdenum compound and a metallic-atom-containing compound or a first mixture including a molybdenum compound, a metallic-atom-containing compound, and an aluminum compound to prepare an intermediate; and a step (2) of firing, at a temperature higher than a temperature selected in the step (1), a second mixture including the intermediate or a second mixture including the intermediate and an aluminum compound.

Abstract: Provided is a surface-treated spinel particle (B) including a spinel particle (A) including a magnesium atom, an aluminum atom, and an oxygen atom and a surface treatment layer disposed at least a portion of the surface of the spinel particle (A). The surface treatment layer includes a surface-treating agent including an organic compound or a cured product of the surface-treating agent. The spinel particle (A) further includes molybdenum. The crystallite diameter of the [111] plane of the spinel particle (A) is 220 nm or more. Also provided are a method for producing the surface-treated spinel particle (B), a resin composition including the surface-treated spinel particle (B), and a molded article.

Abstract: To provide plate-like alumina particles that are less likely to wear apparatuses. Plate-like alumina particles containing germanium or a germanium compound. The plate-like alumina particles preferably have a molar ratio of Ge to Al, [Ge]/[Al], of 0.08 or more as determined in an XPS analysis. The plate-like alumina particles preferably contain the germanium or germanium compound in a surface layer. The plate-like alumina particles preferably have a density of 3.7 g/cm3 or more and 4.1 g/cm3 or less. The plate-like alumina particles preferably have a molar ratio of Ge to Al, [Ge]/[Al], of 0.08 or less as determined in an XRF analysis.

Abstract: Flaky alumina particles including mullite in a surface layer of the flaky alumina particles. A method for producing flaky alumina particles including forming a mixture by mixing together an aluminum compound that contains elemental aluminum, a molybdenum compound that contains elemental molybdenum, and silicon or a silicon compound that contains elemental silicon, the aluminum compound being in an amount greater than or equal to 50 mass %, calculated as Al2O3, the molybdenum compound being in an amount less than or equal to 40 mass %, calculated as MoO3, the silicon or the silicon compound being in an amount of 0.5 mass % or greater and less than 10 mass %, calculated as SiO2, relative to a total mass of the flaky alumina particles taken as 100 mass %; and firing the mixture.

Abstract: Alumina is generally used as an inorganic filler, while spinel, which is known to be lower in thermal conductivity than alumina, is used in applications such as gems, fluorescence emitters, catalyst carriers, adsorbents, photocatalysts and heat-resistant insulating materials, but not expected to be used as a thermally conductive inorganic filler. Thus, an object of the invention is to provide spinel particles having excellent thermal conductive properties. The invention relates to a spinel particle including magnesium, aluminum and oxygen atoms and molybdenum and having a [111] plane crystallite diameter of 220 nm or more.

Abstract: The present invention provides alumina particles having a fixed card-house structure formed of three or more flat plate-like alumina particles and having an average particle diameter of 3 to 1000 ?m. Also, there is provided alumina particles having an average particle diameter of 3 to 1000 ?m and having a fixed card-house structure in which the three or more flat plate-like alumina are aggregated to be crossed each other at two or more plurality of positions, and the plane directions of the flat plates crossed each other are in a state of disordered arrangement.

Abstract: Alumina is generally used as an inorganic filler, while spinel, which is known to be lower in thermal conductivity than alumina, is used in applications such as gems, fluorescence emitters, catalyst carriers, adsorbents, photocatalysts and heat-resistant insulating materials, but not expected to be used as a thermally conductive inorganic filler. Thus, an object of the invention is to provide spinel particles having excellent thermal conductive properties. The invention relates to a spinel particle including magnesium, aluminum and oxygen atoms and molybdenum and having a [111] plane crystallite diameter of 220 nm or more.

Abstract: A spinel compound oxide particle includes metallic atoms, aluminum atoms, oxygen atoms, and molybdenum atoms, wherein the metallic atoms are selected from the group consisting of zinc atoms, cobalt atoms, and strontium atoms, and a crystallite size in a [111] plane is 100 nm or more. Included are a step (1) of firing a first mixture including a molybdenum compound and a metallic-atom-containing compound or a first mixture including a molybdenum compound, a metallic-atom-containing compound, and an aluminum compound to prepare an intermediate; and a step (2) of firing, at a temperature higher than a temperature selected in the step (1), a second mixture including the intermediate or a second mixture including the intermediate and an aluminum compound.

Abstract: Provided are modified cellulose nanofibers that can be easily formed into a composite with a resin containing a solvent and a resin composition that contains the modified cellulose nanofibers. A method for producing modified cellulose nanofibers is characterized in that a step of obtaining modified cellulose by causing cellulose having hydroxyl groups to react with a resin having an intramolecular polybasic anhydride structure and a step of miniaturizing the modified cellulose are performed in the same step. In this method, the polybasic anhydride structure is a cyclic polybasic anhydride structure obtained by ring formation through dehydration condensation of carboxyl groups in the molecule.

Abstract: Provided are modified cellulose nanofibers that can be easily formed into a composite with a resin containing a solvent and a resin composition that contains the modified cellulose nanofibers. A method for producing modified cellulose nanofibers is characterized in that a step of obtaining modified cellulose by causing cellulose having hydroxyl groups to react with a resin having an intramolecular polybasic anhydride structure and a step of miniaturizing the modified cellulose are performed in the same step. In this method, the polybasic anhydride structure is a cyclic polybasic anhydride structure obtained by ring formation through dehydration condensation of carboxyl groups in the molecule.

Abstract: There is provided a pigment dispersion including water, an aqueous polymer and a pigment as essential components, wherein the aqueous polymer is a carboxyl group-containing polyurethane which is formed by reacting a diol compound, a diisocyanate compound and a reaction product, which is mainly composed of a compound represented by general formula (1) and prepared by reacting a diol compound having one or two carboxyl groups within each molecule with a diisocyanate compound and which also has a reaction index as calculated by (Formula 1) within a range from 0.95 to 1.10.

Abstract: There is provided a pigment dispersion including water, an aqueous polymer and a pigment as essential components, wherein the aqueous polymer is a carboxyl group-containing polyurethane which is formed by reacting a diol compound, a diisocyanate compound and a reaction product, which is mainly composed of a compound represented by general formula (1) and prepared by reacting a diol compound having one or two carboxyl groups within each molecule with a diisocyanate compound and which also has a reaction index as calculated by (Formula 1) within a range from 0.95 to 1.10.

Abstract: The present invention provides a polyester resin toner which has good fixing properties and is superior in image quality in a heat roller fixation system without employing an anti-offset solution, and which has a spherical or generally spherical shape and has a small particle diameter, and a method of producing the same. In a toner for electrostatic image development comprising a binder resin and a colorant, said binder resin is made of a polyester resin. Furthermore, the weight-average molecular weight as measured by gel permeation chromatography of a tetrahydrofuran-soluble fraction of said polyester resin contained in the toner is 30,000 or more and the weight-average molecular weight/number-average molecular weight is 12 or more and, moreover, the area ratio of a molecular weight of 600,000 or more is 0.5% or more and the area ratio of a molecular weight of 10,000 or less is within a range of 20-80%.

Abstract: A spherically particulate toner characterized by a volume-average particle diameter of from 1 to 6 &mgr;m, a colorant content of not less than 9.1% by weight, particularly not less than 5% by weight when the colorant is an organic chromatic pigment, based on the total weight of the binder resin and colorant used and an average circularity (average of circularity defined by (perimeter of circle having the same area as the projected area of particle)/(perimeter of the projected image of particle)) of not less than 0.98. The spherically particulate toner according to the present invention gives an excellent image quality and can be consumed in a drastically reduced amount per sheet of printing paper. By predetermining the particle size distribution of spherical toner particles and the added amount of inorganic oxide fine particles to optimum values, the image quality can be further improved.

Abstract: The present invention provides a novel developer comprising a spherically particulate toner having a volume-average particle diameter of from about 1 to 6 &mgr;m for use in the development of electrostatic image in electrophotographic copying machines or printers having a colorant content of from 8 to 20% by weight, if the colorant is carbon black, or from 3 to 20% by weight, if the colorant is an organic pigment, based on the sum of the weight of binder resin and colorant and a resin-coated carrier having a volume-average particle diameter of from 20 to 150 &mgr;m. The present invention also provides a suitable polymerization or emulsification process for the preparation of a particulate toner to be incorporated in the developer. The use of the electrostatic image developer makes it possible to not only improve the quality of images provided by copying machines or printers but also realize drastic reduction of the amount of toner to be consumed per sheet of printing paper.

Abstract: A non-magnetic one-component development process is provided which comprises supplying a developer onto a photoreceptor using a non-magnetic one-component developing machine comprising at least a developer-supporting roll and a layer-forming blade so that an electrostatic latent image on said photoreceptor is developed, characterized in that as said developer there is used a spherically particulate toner having a volume-average particle diameter of from 1 to 6 .mu.m and the amount of said toner to be attached to said developer-supporting roll is from 0.1 mg/cm.sup.2 to 0.45 mg/cm.sup.2. In accordance with the process of the present invention, the image quality can be drastically improved while drastically reducing the consumed amount of the toner.