Alumina powder

• Main Authors: Kuroda, Taketoshi, Terao, Masaki, Tsuneishi, Taku
• Format: Patent
• Language: English
• Published: 05.05.2020
• Subjects: ADHESIVES; CHEMISTRY; COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM,CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THERARE-EARTH METALS; DYES; INORGANIC CHEMISTRY; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; MIXING, e.g. DISSOLVING, EMULSIFYING, DISPERSING; NATURAL RESINS; PAINTS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; POLISHES; PREPARATION OF CARBON BLACK; TRANSPORTING; TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS,TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES

An alumina powder containing a hydroxycarboxylic acid and an alkaline component contains amorphous alumina, pseudoboehmite, or boehmite, and satisfies all of (1) to (4). (1) A colloidal dispersion A with 2.5% by mass of Al2O3 consisting of the alumina powder and distilled water is free from precipitate, and has a light transmittance of at least 80% measured at a wavelength of 500 nm and an optical path length of 10 mm. (2) A colloidal dispersion B with 15% by mass of Al2O3 consisting of the alumina powder and distilled water is free from precipitate. (3) The dispersions A and B have a pH in a range of 5 to 8. (4) A colloidal dispersion C with 2.5% by mass of Al2O3 consisting of the alumina powder and methanol is free from precipitate, and has a light transmittance of at least 80% measured under the above condition.