Retention and Redistribution of Ink-Jet Ink Components in Printed Media

Abstract

Organic compounds having high boiling points included in inkjet inks remain in the printed media after printing. It has been said that these residual organic compounds influenced the scratch-fastness of pigment ink prints but the detailed mechanisms have not been reported. Glycerin was selected as a typical example of those organic compounds. Pyrolysis gas chromatography was used to quantify the residual glycerin in the pigment ink layer. It was found that glycerin remained in the pigment ink layer for at least 72 hours after printing. The total amount of the residual glycerin varied greatly depending on the paper samples. The discrepancy results between changes of contact angle of glycerin and the rate of glycerin absorption into various paper samples were assumed to be due to the difference in the diffusion rate of residual glycerin by extensional wetting depending on the surface properties of the various coatings of the samples. In addition, the amount of residual glycerin was inversely proportional to the scratch-fastness of the pigment ink layers. It seems that residual glycerin prevents cohesion between particles of the ink pigment.