Journal of Applied Polymer Science, Vol.115, No.3, 1803-1813, 2010
Synthesis of UV-Curable/Alkali-Soluble Dispersants Used for Black Photoresist with a High Loading of Carbon Black
This research synthesized a functional dispersant, not only providing a good dispersion of carbon black (CB) but also possessing ultraviolet (UV)-curable and alkali-soluble properties, by a two-step process. Firstly, bisphenol-A epoxy diacrylate was reacted with benzophenone tetracarboxylic dianhydride at different molar ratios to obtain UV-curable/alkali-soluble resins. In the second step, these resins would possess dispersion ability of CB by reaction with an isocyanate-containing methacrylate. The prepared dispersants were evaluated by their dispersion ability and the light absorption property of CB. The results showed that one of the dispersants was able to disperse CB in the solvent up to 10 wt % with a mean particle size about 100 nm. This particular dispersant had a moderate amount of amino-containing groups (such as urethane, amide, and imide) serving as anchoring sites on CB, and a sufficiently long chain (M-n similar to 2600) to provide a steric repulsion among CB particles. The advantage of this CB/dispersant system is that no other curable resins are needed. By using a suitable photoinitiator, the present CB/dispersant system could reach a polymerization rate of 1.05 x 10(-3) (s(-1)), and a black pattern of 10 mu m in width on a glass substrate was obtained through an UV-lithography process. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 1803-1813, 2010