Dic Corporation

Dainippon Ink and Chemicals, Incorporated

Dianippon Ink and Chemicals, Inc.

Kazuo Itoya

Jian-Jun Yuan

Takashi Ito

Hitoshi Takayanagi

Minoru Nomura

Hironobu Oki

Masamichi Hayashi

Hiroshi Kinoshita

Yoshiyuki Sano

Takayuki Kanematsu

Shingo Takada

Kenichi Hirabayashi

Fumihiko Maekawa

Masaki Iida

Yukiko Soma

Masahiro Yoshida

Kenichi Hamada

Kinji Shinzo

Toshiro Kogawara

Koichiro Matsuki

Yasuyo Yoshimoto

Tomoaki Harada

Atsushi Oshio

Toyomi Hashizume

Hiroko Sakurai

Hiroyuki Ohminato

Yasuyo Sakamoto

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 AlO, the molybdenum compound being in an amount less than or equal to 40 mass %, calculated as MoO, the silicon or the silicon compound being in an amount of 0.5 mass % or greater and less than 10 mass %, calculated as SiO, relative to a total mass of the flaky alumina particles taken as 100 mass %; and firing the mixture.

Flaky alumina particles and method for producing flaky alumina particles

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/cmor more and 4.1 g/cmor 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.

Tabular alumina particles and method of producing tabular alumina particles

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 &#x3bc;m. Also, there is provided alumina particles having an average particle diameter of 3 to 1000 &#x3bc;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.

Alumina particle

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.

Surface-treated spinel particles, method for producing the same, resin composition, and molded article

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.

Spinel compound oxide particle, method for producing the same, resin composition including spinel compound oxide particle, and molded article

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.

Spinel particles, method for producing same and composition and molded article including spinel particles

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.

Method for producing modified cellulose nanofibers

There is provided a pigment dispersion including water, an aqueous polymer and a pigment as essential components, Reaction index=(reaction rate of isocyanate group)&#xd7;[(number of moles of diisocyanate compound())/(number of moles of diol compound())]&#x2003;&#x2003;(Formula 1)

Pigment dispersion and aqueous ink for inkjet recording

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%. The toner for electrostatic image development has a spherical or generally spherical shape having the average circularity (average value of circularity defined by (perimeter of a circle having the same area as that of a projected area of particles)/(perimeter of a projected image of particles)) of 0.97 or more.

Toner for electrostatic image development

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.

Spherical toner particle

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.

Electrostatic image developer

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. In particular, by predetermining the colorant content in the spherically particulate toner to be used in the development process of the present invention to not less than 8% by weight, if the colorant is carbon black, or not less than 3% by weight, if the colorant is an organic pigment, the image quality can be further improved. Further, by optimizing the circularity, particle size distribution, added amount of inorganic material fine particles and other conditions of the spherically particulate toner, the image quality can be even further improved.

Image forming method using spherical toner particle

Disclosed are an electrophotographic toner which is a spherical particle comprising a binder resin having encapsulated therein a colorant and has a volume average particle size of from 3 to 12 .mu.m, the binder resin being a non-crosslinked styrene-acrylic resin having an acid value of from 30 to 120, containing from 5 to 60% by weight of the components having a molecular weight in terms of polystyrene by gel permeation chromatography of 200,000 or more and having a ratio (Mw/Mn) of the weight-average molecular weight Mw to the number-average molecular weight Mn of from 4 to 30; and a process for preparing an electrophotographic toner comprising spherical particles having a volume average grain size of from 3 to 12 .mu.m, the process comprising mixing a mixture comprising the above-described resin, a colorant, a wax and an organic solvent as essential components with an aqueous medium in the presence of a neutralizer in an amount sufficiently large to render the resin self-emulsifiable to effect phase inversion emulsification, thereby producing particles each comprising a binder resin having encapsulated therein a colorant and a wax in the liquid medium, and separating and drying the particles. The toner obtained by the present invention is improved in the thermal fixing characteristics and the environmental stability of charging, exhibits a wide fixing temperature width at the heated roll fixing and has excellent triboelectricity.

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Sakura, Japan

Kazuo Itoya