Abstract
Effect of heat treatment conditions on properties of aqueous alumina green sheets was investigated. A suspension was prepared by mixing alumina, water and binder using a ball mill. The binder was acrylic ester and acrylic acid copolymer stabilized at pH 8.5 with a dilute ammonium solution. Green sheets were fabricated with a doctor blade. The suspension was cast on a PET film and dried at 70°C 1h. The green sheets were heated at 80°, 100°, 120°, 150°, and 200°C for 1h. The properties of green sheets, such as strength, extension, solubility in a dilute ammonium solution and adsorption behavior of moisture changed remarkably at the temperature of treatment from 120° to 150°C. FTIR analysis revealed that changes in the properties of green sheets were caused by self-crosslinking of carboxylic groups of the binder. A small amount of water in a green sheet was found to be a kind of plasticizer.
