Toda Kogyo Corporation

Imation Corporation

Kenji Okinaka

Masayuki Uegami

Yasutaka Ota

Kohji Mori

Hirofumi Kawasaki

Akio Mishima

Norimichi Nagai

Tomoko Okita

Mamoru Tanihara

Junichi Kawano

Koji Kakuya

Masaaki Maekawa

Yasuhiko Fujii

Kousaku Tamari

Tosiharu Harada

Minoru Yamasaki

Yoshiro Okuda

Katsunori Fujimoto

Kunio Ikemoto

Akihisa Kajiyama

Seiji Okazaki

Akinori Yamamoto

Haruki Kurokawa

Shoichi Fujino

Katsumi Yamashita

Wataru Oda

Ryuta Masaki

Tomohiro Honda

Akino Sato

Jean A Lown

Toshiaki Hiramoto

Daisuke Morita

Manabu Matsumoto

Kunihiro Kouchi

Soichi Yatagai

Hiroki Kamon

Soichi Yatagi

Andreas D Jazdanian

Ryota Fujimoto

Kazushi Nishimoto

Tetsuya Kodaira

Takayuki Yamamura

Katsuhiro Fujita

Masashi Kobino

Akino Ito

Takahisa Nishio

Kouta Sato

The present invention relates to nickel-cobalt-manganese-based compound particles which have a volume-based average secondary particle diameter (D50) of 3.0 to 25.0 &#x3bc;m, wherein the volume-based average secondary particle diameter (D50) and a half value width (W) of the peak in volume-based particle size distribution of secondary particles thereof satisfy the relational formula: W&#x2266;0.4&#xd7;D50, and can be produced by dropping a metal salt-containing solution and an alkali solution to an alkali solution at the same time, followed by subjecting the obtained reaction solution to neutralization and precipitation reaction. The nickel-cobalt-manganese-based compound particles according to the present invention have a uniform particle size, a less content of very fine particles, a high crystallinity and a large primary particle diameter, and therefore are useful as a precursor of a positive electrode active substance used in a non-aqueous electrolyte secondary battery.

Nickel-cobalt-maganese-based compound particles and process for producing the nickel-cobalt-manganese-based compound particles, lithium composite oxide particles and process for producing the lithium composite oxide particles, and non-aqueous electrolyte secondary battery

Iron composite particles for purifying soil or ground water, comprise &#x3b1;-Fe and magnetite, and having a ratio of a diffraction intensity Dof (110) plane of &#x3b1;-Fe to a sum of a diffraction intensity Dof (311) plane of magnetite and the diffraction intensity D(D/(D+D)) of 0.30 to 0.95 as measured from X-ray diffraction spectrum of the iron composite particles, an Al content of 0.10 to 1.50% by weight and an S content of 3500 to 7000 ppm; a process for producing the iron composite particles; a purifying agent containing the iron composite particles; a process for producing the purifying agent; and a method for purifying soil or ground water.

Iron composite particles for purifying soil or ground water, process for producing the same, purifying agent containing the same, process for producing the purifying agent and method for purifying soil or ground water

A purifying agent for purifying soil or ground water which comprises a water suspension containing iron composite particles comprising &#x3b1;-Fe and magnetite, and having an average particle diameter of 0.05 to 0.50 &#x3bc;m, an S content of 3500 to 10000 ppm and an Al content of 0.10 to 1.50% by weight, and polyaspartic acid or a salt thereof. The purifying agent is capable of decomposing aliphatic organohalogen compounds or aromatic organohalogen compounds contained in the soil or ground water in an efficient, continuous and economical manner.

Purifying agent for purifying soil or ground water, process for producing the same, and method for purifying soil or ground water using the same

Iron particles for purifying soil or ground water of the present invention comprise a mixed phase of &#x3b1;-Fe phase and FeOphase, and having a BET specific surface area of 5 to 60 m/g, an Fe content of not less than 75% by weight based on the weight of the iron particles and a sulfur content of not less than 1,000 ppm. The iron particles are capable of decomposing or insolubilizing harmful substances such as organohalogen compounds and/or heavy metals, cyanogen, etc. contained in the soil or ground water in efficient, continuous and economical manners.

Process for purifying contaminated soil or groundwater with iron particles

Iron particles for purifying contaminated soil or ground water

The present invention relates to spindle-shaped goethite particles having an average major axial diameter of 0.05 to 0.18 &mgr;m, spindle-shaped hematite particles having an average major axial diameter of 0.05 to 0.17 &mgr;m, spindle-shaped magnetic metal particles containing iron as a main component, which exhibit an adequate coercive force, good dispersibility, good oxidation stability and excellent coercive force distribution notwithstanding the average major axial diameter thereof is as small as 0.05 to 0.15 &mgr;m, and processes for producing the respective particles. Especially, the spindle-shaped magnetic metal particles containing iron as a main component, have an average major axial diameter of 0.05 to 0.15 &mgr;m, an aspect ratio of from 5:1 to 9:1, a size distribution (standard deviation/average major axial diameter) of not more than 0.30, a crystallite size D of 130 to 160 &angst;, a Co content of from 0.5 to less than 6 atm % based on whole Fe, an Al content of from more than 10 to less than 20 atm % based on whole Fe, a rare earth element content of from 1.5 to 5 atm % based on whole Fe, an atomic ratio of Al to Co of from more than 2 to 4, a coercive force of 111.4 to 143.2 kA/m, an oxidation stability of saturation magnetization (&Dgr;&sgr;s) of not more than 10%, and an ignition temperature of not less than 130&deg; C.

Spindle-shaped goethite particles, spindle-shaped hematite particles, spindle-shaped magnetic metal particles containing iron as main component and processes for producing the same

Secondary agglomerates of magnetic metal particles for magnetic recording, have a sodium content of not more than 20 ppm and a calcium content of not more than 40 ppm, an average particle diameter of 300 to 800 &mgr;m and an upper limit of particle diameters of 2,000 &mgr;m, and comprise magnetic metal primary particles having an average major axis diameter of 0.05 to 0.25 &mgr;m.

Secondary agglomerates of magnetic metal particles for magnetic recording and process for producing the same

Spindle-shaped magnetic alloy particles containing Fe and Co as main components of the present invention have a cobalt content of 20 to 50 atm % (calculated as Co) based on whole Fe; an average major axis diameter (L) of 0.03 to 0.10 &mgr;m; a coercive force value of 159.2 to 238.7 kA/m (2,000 to 3,000 Oe); a crystallite size of 100 to 160 &angst;; and an activation volume (V ) of 0.01 to 0.07E-4 &mgr;m . A high-density magnetic recording medium produced by using such spindle-shaped magnetic alloy particles containing Fe and Co as main components, have an excellent output characteristics in a short wavelength region, a considerably reduced noise and an excellent storage stability.

Spindle-shaped magnetic alloy particles for magnetic recording, and magnetic recording medium

Secondary agglomerates of magnetic metal particles containing primary particles having an average major axial diameter of 0.05 to 0.25 &mgr;m, said secondary agglomerates having an average particle diameter of 300 to 800 &mgr;m, an upper limit of particle diameter of 2,000 &mgr;m and a repose angle of 38 to 45&deg;. The secondary agglomerates exhibit not only excellent handing property due to high storage efficiency, high transport efficiency and good flowability thereof, but also excellent kneading property when kneaded with various binder resins and organic solvents in a kneader, and excellent dilution-dispersibility when diluted with an additional amount of the organic solvent, upon the production of coating-type magnetic recording media, so as to more improve a surface smoothness and squareness of a magnetic coating film obtained therefrom, and a process for producing such secondary agglomerates of magnetic metal particles for magnetic recording.

Spindle-shaped magnetic metal particles containing iron as main component and processes for producing the same

Spindle-shaped hematite particles obtained form the spindle-shaped goethite particles, can be prevented as highly as possible from causing destruction of particle shape when subjected to a heat-reduction step for producing magnetic spindle-shaped metal particles and magnetic spindle-shaped metal particles containing iron as a main component produced from the spindle-shaped goethite particles or the spindle-shaped hematite particles as a starting material, exhibit a high coercive force, an excellent particle coercive force distribution, a large saturation magnetization and an excellent oxidation stability, and are excellent in a squareness (Br/Bm) of the sheet due to a good dispersibility in a binder resin.

Spindle-shaped hematite particles and process for making spindle-shaped hematite particles

Spindle-shaped goethite particles are disclosed, which contain not less than 0.5 and less than 8 atom % of Co based on the total Fe and 5 to 10 atom % of Al based on the total Fe, and have an average major axis diameter of 0.18 to 0.30 &mgr;m, a size distribution (standard deviation/major axis diameter) of not more than 0.22, an average minor axis diameter of 0.025 to 0.045 &mgr;m and an average aspect ratio is 5 to 10. Spindle-shaped hematite particles and spindle-shaped magnetic iron-based alloy particles are also disclosed, which are produced from the above goethite particles. The spindle-shaped goethite particles of the present invention provide spindle-shaped magnetic iron-based alloy particles which are excellent in dispersibility (high squareness and high orientation), excellent both in weatherability and in coercive force distribution, and are useful as household DAT, 8 mm, Hi-8 tapes, VTR tapes for business purposes, computer tapes or floppy disks.

Spindle-shaped goethite particles, spindle-shaped hematite particles, spindle-shaped magnetic iron-based alloy particles, and process for producing the same

Spindle-shaped metal particles and a process for producing magnetic spindle-shaped metal particle containing iron as a main component, which contains cobalt of 8 to 45 atm % calculated as Co, aluminum of 5 to 20 atm %, calculated as Al, and a rare earth element of 1 to 15 atm %, calculated as rare earth element, wherein the particles have an average major axial diameter of 0.05 to 0.15 &mgr;m, an average minor axial diameter of 0.010 to 0.022 &mgr;m, an aspect ratio of 4:1 to 8:1, a particle size distribution of not more than 0.20, and an X-ray crystallite size D110 of 12.0 to 17.0 nm. The spindle-shaped metal particles have a high coercive force, an excellent particle coercive force distribution, a large saturation magnetization and an excellent oxidation stability, and are excellent in a squareness (Br/Bm) of the sheet due to a good dispersibility in a binder resin.

Spindle-shaped goethite particles, spindle-shaped hematite particles and magnetic spindle-shaped metal particles containing iron as main component

The present invention relates to a spindle-shaped goethite particles containing cobalt of 8.0 to 50.0 atm %, calculated as Co, based on the total Fe in the spindle-shaped goethite particles and a compound of at least one element selected from the group consisting of Al, Si, Nd, Y, La, Ce, Pr, Tb, Ca, Mg, Ba and Sr of not more than 25.0 atm %, calculated as the element, based on the total Fe in the spindle-shaped goethite particles, and having an average major axis diameter of 0.05 to 0.15 .mu.m, a size distribution (standard deviation/major axis diameter) of not more than 0.30, an average minor axis diameter of 0.010 to 0.025 .mu.m, an aspect ratio of 4 to 8 and an X-ray crystallite size ratio (D.sub.020 /D.sub.110) of 2.0 to 3.5. These spindle-shaped goethite particles are useful as raw material of spindle-shaped magnetic iron-based alloy particles containing cobalt and iron as the main ingredients, which have a uniform particle size, no inclusion of dendrites, a high coercive force, an excellent coercive force distribution, a large saturation magnetization, and in addition, an excellent stability against oxidation.

Spindle-shaped geothite particles

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Ube, Japan

Kenji Okinaka