PROCESS FOR IMPROVING THE HYDROPHILICITY OF THE SUBSTRATE FOR A LITHOGRAPHIC PRINTING PLATE BY TREATMENT WITH POLYVINYL PHOSPHONIC ACID

摘要

Provided herein a process to improve the hydrophilicity of the surface of the substrate for a lithographic printing plate. The inventive process comprises treating said surface with a solution of polyvinyl phosphonic acid which is maintained at a pH range of about 2.5 to about 6.6 at a temperature range of ambient to about 212 DEG F for about 5-20 seconds. The process substantially reduces sensitivity to background toning, thereby substantially improving the quality of images printed from using the inventive lithographic printing plate.