PRETREATING LIQUID FOR BURNING AND PHOTOENGRAVING METHOD

摘要

PURPOSE:To eliminate ground stains and to improve the sensitizing characteristic of an image part by applying a pretreating liquid for burning consisting of an aq. soln. contg. a phytic acid and/or the water soluble salt thereof and sulfite on a lithographic printing pate prior to the burning treatment after developing and subjecting said plate to the burning treatment in the presence of said compd. CONSTITUTION:The aq. soln. contg. the phytic acid and/or the water soluble salt thereof and sulfite is applied on the lithographic printing plate prior to the burning treatment after development and is subjected to the burning treatment in the presence of said compd. The content of the phytic acid and/or the water soluble salt thereof in the pretreating liquid for burning is 1-40wt% (hereafter abbreviated as %), more preferably 3-30%. The lithographic printing plate which obviates the generation of the stains in the non-image part, has the high sensitizing characteristic in the image part and has excellent print resisting power is thus obtd.