Investigation of a Light-Thermal Sensitive Imaging System Based on the Microcapsule Technique

Abstract

A silver-free photothermal sensitive imaging system which captures a photo image with microcapsules and can be thermal processed has been investigated. The photosensitive functional compounds are encapsulated with the interface polymerization method. Scanning Electron Micrographs show that the shape and diameter of the resulting microcapsules are comparable with silver halide grains under the condition of a shear velocity at 7000 rpm and a protecting colloidal concentration of 4.5% polyvinyl alcohol. Microcapsules with size smaller than 1 μm have been synthesized, which can act as basic imaging cells with excellent resolution compared with silver halide materials. The infrared spectra indicate that the wall of the microcapsule is composed of polyurea. The thermal response of the wall material detected with the thermal gravimetric and differential scanning calorimetry technique show that the optimal thermal development temperature is about 135 °C. Image density research confirms that the mechanism of image formation may be ascribed to the penetrability variety of the microcapsule under given thermal condition after exposure.