Preparation of vaterite type calcium carbonate by using ultrasound and application to ink-jet paper

摘要

Calcium carbonate is used widely in various industries because it is costless and harmless. Vaterite is one type of crystal form of calcium carbonate and occurs rarely in nature. This study aims at safe synthesis method to prepare vaterite and its application to ink-jet paper. A new method for preparing pure vaterite has been established by using ultrasonic homogenizer to mix and agitate K_2CO_3 and CaCl_2 solutions. Shapes and sizes of vaterite particles formed are controllable by selecting a surfactant present in the mixing solution. Vaterite type calcium carbonate is easily transformed into calcite type in water. However, high pH, addition of surfactant SDBS (Sodium Dodecyl Benzene Sulfonate) and immersion in ethanol lowered or prevented crystal transformation because of low solubility constants. Ink-jet printing test was performed with vaterite-coated paper and resulted in high print quality. Bleeding problem did not occur as well as commercial silica coated ink-jet paper, although calcite coated and trial silica coated papers exhibited worse bleeding probably because high hydrophilicity of vaterite promoted quick absorption of inks inward before spreading laterally on the surface.