Abstract: The present invention provides magnetic iron oxide particles having a high bonding property to a resin as well as a magnetic carrier for electrophotographic developers which is improved in durability by enhancing adhesion between a magnetic carrier core material and a coating resin. The magnetic iron oxide particles of the present invention are magnetic iron oxide particles having an average particle diameter of 0.5 to 30 ?m onto which a plurality of granules are bonded, and the magnetic carrier for electrophotographic developers according to the present invention is a magnetic carrier for electrophotographic developers which comprises spherical magnetic composite particles produced by dispersing magnetic iron oxide particles in a binder resin in which the magnetic iron oxide particles comprise at least the above magnetic iron oxide particles having an average particle diameter of 0.5 to 30 ?m onto which the plurality of granules are bonded.

Abstract: Black magnetic iron oxide particles having an average particle diameter of 0.05 to 2.0 ?m and an electric resistance value at an applied voltage of 100 V of not less than 1×108 ?·cm. Also a magnetic carrier for electrophotographic developer having spherical magnetic composite particles obtained by dispersing black magnetic iron oxide particles in a binder resin. The magnetic carrier has an electric resistance value R100 at an applied voltage of 100 V of 1×108 to 1×1014 ?·cm, and an electric resistance value R300 at an applied voltage of 300 V which satisfies the relationship represented by the formula: 0.1?R300/R100?1.

Abstract: The present invention provides aniline black comprising no harmful substances such as chromium and copper in its products and having an excellent blackness and a high resistivity value, as well as provides a black resin composition, a water-based dispersion and a solvent-based dispersion which are colored with the aniline black and have an excellent dispersibility. The aniline black according to the present invention has a sulfur content of 0.2 to 6.0% by weight and comprises primary particles having an average major axis diameter of 0.05 to 0.80 ?m.

Abstract: The present invention provides magnetic iron oxide particles having a high bonding property to a resin as well as a magnetic carrier for electrophotographic developers which is improved in durability by enhancing adhesion between a magnetic carrier core material and a coating resin. The magnetic iron oxide particles of the present invention are magnetic iron oxide particles having an average particle diameter of 0.5 to 30 ?m onto which a plurality of granules are bonded, and the magnetic carrier for electrophotographic developers according to the present invention is a magnetic carrier for electrophotographic developers which comprises spherical magnetic composite particles produced by dispersing magnetic iron oxide particles in a binder resin in which the magnetic iron oxide particles comprise at least the above magnetic iron oxide particles having an average particle diameter of 0.5 to 30 ?m onto which the plurality of granules are bonded.

Abstract: The present invention provides aniline black comprising no harmful substances such as chromium and copper in its products and having an excellent blackness and a high resistivity value, as well as provides a black resin composition, a water-based dispersion and a solvent-based dispersion which are colored with the aniline black and have an excellent dispersibility. The aniline black according to the present invention has a sulfur content of 0.2 to 6.0% by weight and comprises primary particles having an average major axis diameter of 0.05 to 0.80 ?m.

Abstract: The present invention relates to black magnetic iron oxide particles having an average particle diameter of 0.05 to 2.0 ?m and an electric resistance value at an applied voltage of 100 V of not less than 1×108 ?·m; and a magnetic carrier for electrophotographic developer comprising spherical magnetic composite particles obtained by dispersing black magnetic iron oxide particles in a binder resin, wherein the magnetic carrier has an electric resistance value R100 at an applied voltage of 100 V of 1×108 to 1×1014 ?·m, and an electric resistance value R300 at an applied voltage of 300 V which satisfies the relationship represented by the formula: 0.1?R300/R100?1.

Abstract: The present invention relates to a black magnetic iron oxide particles each having a polyhedral shape wherein when a percentage of dissolution of iron element based on a total amount of iron element contained in the black magnetic iron oxide particles is 50%, a percentage of dissolution of sulfur element based on a total amount of sulfur element contained in the black magnetic iron oxide particles is less than 40%.

Abstract: The present invention relates to black magnetic iron oxide particles comprising core particles and a surface layer formed on a surface of the respective core particles which is made of a compound of at least one alkali earth metal element selected from the group consisting of Mg, Ca, Sr and Ba and an aluminum element, in which a content of the at least one alkali earth metal element present in the surface layer is from 100 ppm to 1000 ppm on the basis of a whole weight of the black magnetic iron oxide particles; a content of the aluminum element present in the surface layer is from 1000 ppm to 20000 ppm on the basis of a whole weight of the black magnetic iron oxide particles; a ratio [A/B] of the content [A (ppm)] of the aluminum element to the content [B (ppm)] of the at least one alkali earth metal element present in the surface layer is from 1 to 100; and a molded product comprising said black magnetic iron oxide particles has a breakdown voltage of not less than 400 V/cm.

Abstract: The present invention relates to a black magnetic iron oxide particles each having a polyhedral shape wherein when a percentage of dissolution of iron element based on a total amount of iron element contained in the black magnetic iron oxide particles is 50%, a percentage of dissolution of sulfur element based on a total amount of sulfur element contained in the black magnetic iron oxide particles is less than 40%.

Abstract: The present invention relates to black magnetic iron oxide particles comprising core particles and a surface layer formed on a surface of the respective core particles which is made of a compound of at least one alkali earth metal element selected from the group consisting of Mg, Ca, Sr and Ba and an aluminum element, in which a content of the at least one alkali earth metal element present in the surface layer is from 100 ppm to 1000 ppm on the basis of a whole weight of the black magnetic iron oxide particles; a content of the aluminum element present in the surface layer is from 1000 ppm to 20000 ppm on the basis of a whole weight of the black magnetic iron oxide particles; a ratio [A/B] of the content [A (ppm)] of the aluminum element to the content [B (ppm)] of the at least one alkali earth metal element present in the surface layer is from 1 to 100; and a molded product comprising said black magnetic iron oxide particles has a breakdown voltage of not less than 400 V/cm.

Abstract: There are provided magnetic iron oxide particles having an average particle diameter (Dp50) of primary particles of 0.05 to 0.3 ?m, an average particle diameter (Da50) of secondary particles of 0.055 to 0.9 ?m, and a ratio of the average particle diameter (Da50) of the secondary particles to the average particle diameter (Dp50) of the secondary particles (Da50/Dp50) of 1.1 to 3.0, as well as a magnetic toner containing the magnetic iron oxide particles. The magnetic iron oxide particles of the present invention are in the form of small agglomerated particles and exhibit an excellent dispersibility, and the magnetic toner using the magnetic iron oxide particles is excellent in electrification stability.

Abstract: The present invention relates to a colorant as a precursor of inks for ink-jet printing or for display of a color filter, a dispersion containing the colorant, and an ink, more specifically relates to colored resin particles which are excellent in color developability of printed matters, transparency and gloss, and can produce images having an excellent image fastness such as light resistance, water resistance and fixing property, and further which can exhibit an excellent storage stability by itself upon preparing an ink, and is free from clogging of a print head and is excellent in ejection stability upon printing; a water-based dispersion containing the colored resin particles, and an ink for ink-jet printing or an ink for color filter.

Abstract: There are provided magnetic iron oxide particles having an average particle diameter (Dp50) of primary particles of 0.05 to 0.3 ?m, an average particle diameter (Da50) of secondary particles of 0.055 to 0.9 ?m, and a ratio of the average particle diameter (Da50) of the secondary particles to the average particle diameter (Dp50) of the secondary particles (Da50/Dp50) of 1.1 to 3.0, as well as a magnetic toner containing the magnetic iron oxide particles. The magnetic iron oxide particles of the present invention are in the form of small agglomerated particles and exhibit an excellent dispersibility, and the magnetic toner using the magnetic iron oxide particles is excellent in electrification stability.

Abstract: Black iron-based particles comprise a FeTiO3—Fe2O3 solid solution or a mixed composition of a FeTiO3—Fe2O3 solid solution and an iron-based oxide having a spinel structure, and having a Ti content of from more than 10.0 atm % to 40.0 atm %, calculated as Ti, based on whole Fe, and a blackness (L* value) of 6 to 13.

Abstract: Black iron-based particles comprise a FeTiO3—Fe2O3 solid solution or a mixed composition of a FeTiO3—Fe2O3 solid solution and an iron-based oxide having a spinel structure, and having a Ti content of from more than 10.0 atm % to 40.0 atm %, calculated as Ti, based on whole Fe, and a blackness (L* value) of 6 to 13.

Abstract: Black magnetic iron oxide particles having an average particle diameter of 0.05 to 1.0 &mgr;m have a three-phase structure comprising: a core portion containing at least one metal element other than Fe selected from the group consisting of Mn, Zn, Cu, Ni, Cr, Cd, Sn, Mg, Ti, Ca and Al in an amount of 0.1 to 10% by weight based on whole Fe contained in the particles; a surface coat portion containing at least one metal element other than Fe selected from the group consisting of Mn, Zn, Cu, Ni, Cr, Cd, Sn, Mg, Ti, Ca and Al in an amount of 0.1 to 10% by weight based on whole Fe contained in the particles; and an intermediate layer disposed between the core portion and the surface coat portion, containing substantially none of the metal elements other than Fe.

Abstract: Black iron-based particles comprise a FeTiO3—Fe2O3 solid solution or a mixed composition of a FeTiO3—Fe2O3 solid solution and an iron-based oxide having a spinel structure, and having a Ti content of from more than 10.0 atm % to 40.0 atm %, calculated as Ti, based on whole Fe, and a blackness (L* value) of 6 to 13.

Abstract: Black magnetic iron oxide particles having an average particle diameter of 0.05 to 1.

Abstract: Black magnetic iron oxide particles of the present invention having an average particle diameter of 0.1 to 0.3 &mgr;m, comprise: black spinel iron oxide particles as core particles; and a surface coat formed on the surface of each core particle, comprising fine spinel iron oxide particles, the content of FeO in a surface layer having a thickness of from a surface of each black magnetic iron oxide particle to about 3.5% per a radius of each black magnetic iron oxide particle, being 8 to 14% by weight based on the weight of Fe contained in said surface layer. Such black magnetic iron oxide particles not only have a sufficient blackness and excellent electrical properties, flowability and electrification property (charging property), but also exhibit a good compatibility with binder resins such as aromatic vinyl-based resins, acrylic-based resins and copolymer resins thereof, and a good dispersibility in these resins for a magnetic toner.

Abstract: Magnetite particles of the present invention have an average particle diameter of 0.05 to 0.50 .mu.m, each of the magnetite particles having a plurality of mountain-shaped protrusions with unsharpened crests on a surface of each magnetite particle, and the number of the mountain-shaped protrusions formed on the surface of each magnetite particle being in the range of 2 to 30 when viewed in projected plan; magnetic iron oxide particles for magnetic toner comprising not less than 60%, in particle number, of the said magnetite particles; and a magnetic toner comprising the said magnetic iron oxide particles and a binder resin. The magnetite particles of the present invention are free from the falling-off from toner particles. The toner particles of the present invention shows a good fluidity and produces visual images having a higher definition upon development of electrostatic latent images.