摘要:
The process for production of iron oxyhydroxide particles according to the invention is characterized by comprising a step (A) in which a suspension containing iron(II) is prepared, and a step (B) in which fine bubbles with diameters of 0.05-500 μm are generated in the suspension to form a reaction mixture, and the iron(II) in the reaction mixture is oxidized by the bubbles to produce iron oxyhydroxide particles.
摘要:
A method for preparing metal oxide particles having a primary particle size on the order of nanometers is provided. The method comprises subjecting a metal ion present in an aqueous solution and an amino alcohol to an initial stage of reaction with each other at normal temperatures under normal pressures for a given time, and adding at least once either of a metal ion or an amino alcohol or both thereof to the resulting reaction system for carrying out a subsequent stage of reaction for a given time wherein total amounts of the metal ion and the amino alcohol are such that the amino alcohol is used in the range of not less than a molar equivalent to the metal ion.
摘要:
Described herein are hollow nanocrystals having various shapes that can be produced by a simple chemical process. The hollow nanocrystals described herein may have a shell as thin as 0.5 nm and outside diameters that can be controlled by the process of making.
摘要:
A powder for an underlayer of a coating-type magnetic recording medium comprises acicular iron oxide particles having an average major axis length in the range of 20-200 nm, has a specific surface area measured by the BET method of 30-100 m2/g and has a powder pH of not greater than 7. The underlayer powder preferably contains 0.1-5.0 wt % of P and optionally contains an amount of R (where R represents one or more rare earth elements, defined as including Y) such that R/Fe expressed in atomic percentage (at. %) is 0.1-10 at. %. The iron oxide powder enhances the properties required of a powder for forming the underlayer of a multi-layer structure coating-type magnetic recording tape, most notably the surface smoothness and strength of the tape.
摘要:
A powder for an underlayer of a coating-type magnetic recording medium, which powder comprises flat-acicular iron oxide particles having an average major axis length of 20-200 nm, a short axis cross-section taken perpendicularly to the long axis that has a long width and a short width, and a short axis cross-section ratio defined as the ratio of the long width to the short width that is greater than 1.3 and substantially uniform in the long axis direction, the powder having a specific surface area measured by the BET method of 30-100 m2/g. The underlayer powder preferably contains 0.1-5.0 wt % of P and, optionally, an amount of R(R representing one or more rare earth elements, defined as including Y) such that R/Fe expressed in atomic percentage (at. %) is 0.1-10 at. %.
摘要:
A process for the production mixed metal oxide containing catalysts comprising the steps of: dissolution of metals Me=Fe, Ni, Al, Cu, Co, Zn, Cr, in nitric acid providing an acid solution of metal mixed nitrate products, aluminium can be added either as nitrate or hydroxide; addition of a carbonhydrate, an amino acid and/or a carboxylic acid; decomposition at 250-700° C. with free air supply of the acid solution by spraying onto the inner surface of one or more rotary kilns, into a spray calcination fluid bed, into a tower kiln or into a steel band conveyor furnace to iron oxide and NOx; and optionally regeneration of the formed NOx to concentrated nitric acid and recycling of produced nitric acid to the first step.
摘要:
A method of forming metal oxide powders includes the steps of solid state mixing of at least one metal nitrate salt and at least one reducing organic acid. The mixture is heated to form a metal oxide powder. A metal oxide precursor intermediate can be formed and then heated to form the metal oxide powder.
摘要:
A method of manufacturing aluminum-substituted hematite represented by α-(Fe1-xAlx)2O3 where x=0.01 to 0.15, by mixing an iron compound and an aluminum compound such that an atomic ratio of Fe to Al falls within the range of 99:1 to 85:15, adding citric acid and ethylene glycol to the mixture of the iron compound and aluminum compound to produce a gel, and pyrolyzing the gel, followed by calcining the pyrolyzed product.
摘要:
High-density acicular hematite particles comprise acicular hematite particles and a coat comprising an oxide of tin or oxides of tin and antimony, formed on at least a part of surfaces of said acicular hematite particles; and have an average major axial diameter of not more than 0.3 mum, a pH value of not less than 8, a soluble sodium salt content of not more than 300 ppm, calculated as Na, and a soluble sulfate content of not more than 150 ppm, calculated as SO4. Such high-density acicular hematite particles is suitable as non-magnetic particles for a non-magnetic undercoat layer of a magnetic recording medium using magnetic particles containing iron as a main ingredient, have an excellent dispersibility in vehicle and a low volume resistivity.