Transparent Ink Absorbing Layer with Water Resistance

Abstract

The transparent ink absorbing layers containing poly (N-vinylpyrrolidone) have been prepared on polyester films. The resulting films showed less than 0.01 absorbance at 350-800nm. Soaking the recording material in water during 14 days caused almost no large change in color patterns printed on it, and the flaking-off and whitening of the recording layers were not observed. The retention rates of black, cyan, and yellow colors, except for magenta one, were more than 50% under an accelerated weathering test during 144 hours. The high weather resistances suggest the formation of a semi-interpenetrating polymer network (SIPN) by a self-condensation reaction of melamine-formaldehyde resin, and the polymer complex formation through hydrogen bonding interactions by a template polymerization of monomers containing carboxyl groups.