Novel UV-curable and alkali-soluble resins for light-shielding black matrix application

A carbon black (CB) photo resist, comprising CB, CB dispersant, photo-curable resin, photo-initiator, and solvent, has been developed in order to prepare a light-shielding black matrix (BM) in the liquid crystal display application. In order to prepare a BM with a high opacity property or optical density (OD), the effect of CB such as its particle and concentration on light absorption property was first evaluated, and the results showed that 45 wt% CB with a particle size of about 100 nm in BM could reach an OD value of 4 μm−1. Moreover, six different UV-curable and alkali-soluble resins (A1, A2, and A3; B1, B2, and B3) were synthesized as photo-curable resins. Structures of these resins were characterized by FTIR and GPC, in which concentrations of various functional groups, especially carboxylic acid and double bond, were calculated. Subsequently, their photo-initiated polymerization rate with or without CB were measured. Finally, it was found that through a proper selection of the newly synthesized resins to prepare a carbon black photo resist, a BM with an OD of 4 μm−1 and a good resolution of 10 μm was successfully prepared upon low UV irradiation energy of 50 mJ/cm2.