Thermal Ctp System Imaging Performance

In recent years, the CTP technology has been developed rapidly throughout the world, and it also has been used widely in the field of printing industry. Thermal CTP technology has the fastest developing speed, so that the market share increases year after year. Thermal plate which is the kernel of thermal CTP technology has become the main driving force to promote technological advance. This study keeps up with the direction of thermal CTP technology, building positive thermal CTP plate with high sensitivity, great tolerance, high resolution and good printability to reduce plate costs and promote its industrialization. That will promote the popularization of CTP technology, which is meaningful for the practice.This study built three kinds of positive thermal CTP systems which mainly consisted of resin, inhibitational/accelerational matter, infrared dyes, thermal acid generator and crystal violet and so on. We chose crystal violet as indicator and adopted ultraviolet spectrophotometry method to investigate alkaline solubility of the film-forming resin, and then gradually studied inhibitational/accelerational matter, infrared dyes and how mutual interaction of them affected alkaline solubility of the film-forming resin in the course of study and experiments. After samples were exposed and developed, the influence of inhibitational/accelerational matter, infrared dyes and thermal acid generator on the lowest exposure energy of image system were investigated by using the density method theory. Based on the basic formulation, the appropriate drying condition, development condition and postbaking condition were selected.The results showed that certain percentage of inhibitational resin, infrared dyes could increase anti-alkaline of film-forming resin, and determinate ratio of accelerational resin could reduce anti-alkaline of film-forming resin. Besides the effects of combination of multicomponent which included inhibitational resin, infrared dyes on anti-alkaline of film-forming resin was more significant than single component. In addition, infrared dyes, inhibitational/accelerational matter and thermal acid generator all produced influence on imaging performance of system by different level. Depending on increasing of infrared dyes content, the lowest exposure energy decreased first and then increased. Depending on increasing of inhibitational resin, the lowest exposure energy increased gradually. With the increasing of accelerational resin content, the lowest exposure energy decreased continuously. Along with the increase of thermal acid generator content, the lowest exposure energy remained the same. A better basic recipe of thermal CTP image system was that infrared dyes content was 1%-2%, inhibitational resin content was 20%-30%, accelerational resin content was 10%-20%, thermal acid generator content was 0, and crystal violet content was 1.5%. The lowest exposure energy of basic recipe was 110 mJ/cm2. The prior imaging conditions were showed as the following:drying condition was 10 minutes, development condition was 24℃and 30S, and postbaking condition was no need.