Application of Vaterite-Type Calcium Carbonate Prepared by Ultrasound for Ink Jet Paper

Vaterite is a crystal polymorph of calcium carbonate that is widely used in various industries, but rarely occurs in nature. This article presents an effective method for application of vaterite-type calcium carbonate as a coating pigment for ink jet paper instead of silica. Vaterite was prepared by mixing and agitating K2CO3 and CaCl2 solutions with an ultrasonic homogenizer. The vaterite crystal stability was examined to achieve vaterite properties appropriate for ink jet application. A high pH reduced transformation from vaterite to calcite because of the low solubility constant. Experiments revealed a low water contact angle on our vaterite-coated paper, suggesting high ink jet print quality. Furthermore, although our test calcite-coated and silica-coated samples exhibited bleeding, our vaterite-coated samples matched commercial silica-coated samples in quality, probably, because the large hydrophilicity of vaterite promoted quick inward absorption of inks before they could spread laterally on the surface. (C) 2010 Society for Imaging Science and Technology. [DOI: 10.2352/J.ImagingSci.Technol.2010.54.2.020504]