| 摘要 |
<p>Case 800815 FINISHER AND PRESERVER FOR LITHOGRAPHIC PLATES Finisher and preserver compositions are provided for desensitizing the non-image areas and protecting the image areas of lithographic plates of either the additive or the subtractive type that utilize substantially any type of exposure chemistry, the composition being useful for hand or machine finishing: they are also low in viscosity, are themselves unusually stable, preserve exposed plates for extended periods of storage time, and eliminate streaking on the plate to which they are applied to thereby substantially eliminate blinding problems during printing. Included in the finisher and preserver composition, which is a single phase aqueous system, are specific ratios of a blend of natural gum and synthetic hydrophilic resins, a preservative for the natural gum resin, a buffer system of phosphate and phosphoric acid, and a surfactant, with the balance being substantially entirely water.</p> |
