Photo-induced aminobenzoate group formation on a polymeric photobase generator bearing N-phenylcarbamate groups and its application to color imaging material

A polymeric photobase generator bearing N-phenylcarbamate groups was prepared to generate aromatic amino groups upon irradiation and used for color imaging on a thin polymer film. Polymer bearing N-phenylcarbamate groups was prepared by copolymerization of methacryloyloxyethyl phenylcarbamate (MPC) and methyl methacrylate (MMA). The photochemical process of the polymer was monitored through the UV and IR absorption spectral analyses and contact angle measurements. Irradiation of the polymer led to the formation of aminobenzoate groups through the photo-Fries type rearrangement or cross-linking through the radical coupling reaction of N-phenylcarbamate groups. The cosinus values of contact angle (θ) of the polymer film decreased upon irradiation indicating that the polymer surface developed a hydrophobic property. A color image was produced by a diazocoupling reaction of the aminobenzoate groups which were produced in the irradiated area of the polymer film with phenolic or aromatic amino coupling agent. The yellow color was developed by resorcinol or aniline treatment, whereas the red color was produced by the naphthol AS or 1-naphthylamine treatment.