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:
Oct. 20, 1981
Filed:
Feb. 19, 1980
Terence Harper, Leeds, GB;
Allen P Gates, Knaresborough, GB;
Vickers Limited, London, GB;
Abstract
A positive working light-sensitive composition comprises in admixture (a) a first component which is an azo dye formed by reacting a p-amino-benzene diazonium salt and a compound including the grouping ##STR1## and (b) a second component which includes a o-quinone diazide and/or a diazonium compound and which, on exposure to light produces an acidic light decomposition product which is capable of reacting with the azo dye to produce a material having a color different to that of the azo dye. The composition exhibits a color change on exposure to light and is useful for the manufacture of light sensitive plates for use in lithographic printing plate production.