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:
Mar. 06, 1979
Filed:
Jul. 23, 1976
Walter L Garrett, Midland, MI (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
An aqueous solution is provided which is suitable for use as a desensitizing gum for treating imaged lithographic printing plates, comprising (1) water, (2) an active polymer component for rendering non-image areas of a lithographic printing plate hydrophilic, comprised of a polyacrylamide-based polymer or copolymer or a blend of polyacrylamide and polyacrylic acid, or the like, said polymer or copolymer or blend having an average molecular weight of from about 5,000 to about 10.sup.6 and having from about 3 to about 70 percent of the carbonyl sites as carboxyl groups, said active polymer component being present in an amount of from about 3 to about 30 weight percent of active polymer component, based on the weight of the active polymer component and the water, and (3) a suitable polyoxyalkylene glycol in an amount which is effective to reduce tackiness while the composition is drying and which does not adversely affect the printing properties of a plate treated with said composition, said polyoxyalkylene glycol being selected from the group consisting of (a) a polyethylene glycol with an average molecular weight of at least about 200; (b) a polypropylene glycol with an average molecular weight of at least about 200; (c) a mixture of components from (a) and (b); (d) a triether of glycerine with a mixture of polypropylene and polyethylene oxides; and (e) a triether of glycerine with polypropylene oxides. The solution is particularly suited for treating imaged lithographic printing plates since, unlike earlier solutions, it does not go through a tacky state when drying.