The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 05, 1981
Filed:
Dec. 17, 1979
Loni Schell, Hofheim-Wallau, DE;
Hoechst Aktiengesellschaft, , DE;
Abstract
A process for the preparation of planographic printing forms is described, in which a light-sensitive material composed of a support having a hydrophilic surface and of a light-sensitive layer, which contains a 1,2-naphthoquinone-diazide, is exposed imagewise, developed and then heated to a temperature above 180.degree. C. for such a time and at such a temperature level that an oleophilic precipitate is formed on the hydrophilic image background, and the precipitate is then removed by treatment, for example wiping over, with an aqueous solution of about 0.01 to 50% by weight of polyvinyl phosphonic acid. The treatment has the advantage that in this case the support surface, for example anodically produced aluminum oxide, is not significantly attacked and is nevertheless completely freed from impurities.