Toda Kogyo Corporation

Nobuya Shimo

Koso Aoki

Naoki Uchida

Hiromitsu Misawa

Eiichi Kurita

Mamoru Kamigaki

Minoru Kozawa

Shinji Uemoto

Yusuke Shimohata

Hiromitsu Sakurai

Ryo Iwai

Muneyoshi Sakamoto

Suehiko Miura

Kohei Uehara

The sodium ferrite particle powder according to the present invention is characterized in that at least one metal or more selected from the metal group consisting of silicon, aluminum, titanium, manganese, cobalt, nickel, magnesium, copper and zinc is contained in an amount of 0.05 to 20% by weight in terms of the oxide, and the molar ratio of Na/Fe is 0.75 to 1.25.

Sodium ferrite particle powder and production method thereof

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 &#x3bc;m.

Aniline black having specific sulfur content, and resin composition and water-based and solvent-based dispersions using the aniline black

The present invention relates to black magnetic iron oxide particles comprising magnetite as a main component, wherein when the black magnetic iron oxide particles are molded into a tablet shape, an electric resistance value of the tablet in an alternating current electric field is controlled to produce an impedance of not less than 2&#xd7;10&#x3a9;cm as measured in a characteristic frequency range thereof. The black magnetic iron oxide particles according to the present invention can provide a toner capable of exhibiting a good charging performance and a uniform charging property under the high-temperature and high-humidity conditions, so that when developing an electrostatic latent image therewith, it is possible to obtain toner images having a high resolution or definition, and further the use of heavy metal elements in the black magnetic iron oxide particles can be minimized.

Black magnetic iron oxide particles

Black iron-based particles comprise a FeTiO&#x2014;FeOsolid solution or a mixed composition of a FeTiO&#x2014;FeOsolid 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.

Black iron-based particles and black toner containing the same

Black magnetic iron oxide particles for magnetic toner and process for producing the same

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Otake, Japan

Nobuya Shimo