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:
Jul. 13, 1993
Filed:
Dec. 11, 1990
Otfried Gaschler, Weisbaden, DE;
Andreas Elsaesser, Idstein, DE;
Dieter Mohr, Budenheim, DE;
Hans W Frass, Wiesbaden, DE;
Hoechst Aktiengesellschaft, Franktfurt am Main, DE;
Abstract
A process for producing negative copies is disclosed in which a light-sensitive or radiation-sensitive recording material comprising a layer support and a normally positive-working light-sensitive or radiation-sensitive layer applied thereto is irradiated imagewise, thermally treated, irradiated overall and then developed with an alkaline developer. Thermal treatment is carried out with water or with an aqueous solution, at temperatures in the range from about 50.degree. to 100.degree. C., preferably from 60.degree. to 90.degree. C., within a period of time varying between about 1 second and 5 minutes, preferably between 5 seconds and 1 minute, overall irradiation is performed on the optionally still hot recording material and development is thereafter carried out within a period of time varying between about 10 seconds and 2 minutes, preferably between 15 seconds and 1 minute. The process can be carried out according to the customary procedure known in the practice of positive processing, and results in perfect printing stencils.