Effect of light stabilizer and UV absorber on light fastness of inkjet ink

Abstract

The problem of light induced fading in an inkjet print is an important weak point, which limits the use of the inkjet prints in outdoor application. The low light fastness property of the inkjet ink can be improved by using light stabilizers. This thesis investigated the effect of a hindered amine light stabilizer and UV absorbers on the light fastness of inkjet ink. These stabilizers were coated on the surface of ink-receiving layer to form a layer, which prevents the fading of the inkjet ink. The UV absorber coating on the inkjet substrate can improve the light fastness of dye-based inkjet ink. The type of UV absorber does not strongly affect the light fastness of the dye-based inkjet ink but it shows an effect on the background color of inkjet printing substrate. The hydroxybenzophenone containing UV absorber does not exhibit this problem. Moreover, the light fastness of dye-based inkjet is in a direct proportion to the amount of UV absorber in the coated layer. In case of HALS coated sheets and double-layered coated sheets (HALS and UV absorber), these coated sheets did not show the effective results to improve the light fastness of dye-based ink. However, the HALS and coated sheets can prevent the ozone induced fading of cyan and its secondary color. In case of the pigmented inkjet ink, the double-layered coated sheets cannot totally improve the light fastness of this kind of ink. However, the layer can somewhat decrease the color change of the low light fastness pigment, especially when the UV absorber layer was coated on the pigmented ink.