Diazotype materials for laser recording

Diazotype materials are sensitive to light in the blue and ultraviolet region. Their photosensitivities are many orders of magnitude lower than silver halide materials. For these reasons, diazotype materials are used mainly as duplicating materials, not for source recordings. In this paper, two methods for improving the photosensitivity of diazotype materials are described. In one method, a small amount of scattering centers are dispersed in the polymer binder of the film to increase the efficiency of the absorbed actinic light in the photodecomposition of the diazonium compound. In another method, the azo dye and vesicular processes are combined in the same film to create a high-density recorded image. The applications of these improved diazotype films to the laser imaging systems and digital data storage are discussed.