| 摘要 |
<p>The lithographic plate has a polymetallic support formed from at least copper or brass and chrome layers. The metals are deposited as thin layers on metallic supports such as steel, aluminium, brass, stainless steel. The metal deposits are covered by an anchoring layer and by a photosensitive layer. The anchoring layer is an ester hydrophobic colloid capable of being regenerated in the form of hydrophilic colloid. The ester hydrophobic colloid is a cellulosic organic acid ester utilised alone or in a mixture. It is chosen from amongst polyvinyl acetate, polyvinyl butyrate and polyvinyl propionate or their mixt. The plate is submitted to actinic radiation through an original so as to create zones which can be eliminated by a known developer, so as to selectively base the anchoring layer. The plaque is cut by means of a known engraving solution so as to selectively eliminate the anchoring layer and the hydrophilic metal. The remaining photosensitive layer remaining being then removed by a known inversion solution to remove the ester of hydrophobic colloid.</p> |
