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:
Sep. 11, 1979
Filed:
Dec. 22, 1975
Catharine E Looney, Wilmington, DE (US);
E. I. DuPont de Nemours and Company, Wilmington, DE (US);
Abstract
Flexible filters capable of transmitting radiation in the spectral range of 315 to 380 nm and absorbing radiation in the spectral range of 400 to 550 nm consist essentially of a thin flexible film, e.g., polyethylene terephthalate containing or having coated thereon a dye in a concentration of 15 to 60 mg/dm.sup.2 and optionally, as a component of the coating, a thermoplastic organic binder, e.g., cellulose acetate butyrate, present in the coating with the dye, said dye being of the formula: ##STR1## where R.sub.1 is lower alkyl of 1 to 5 carbon atoms; R.sub.2 and R.sub.3, which may be the same or different, are selected from the group consisting of R.sub.1, 2-cyanoethyl, 2-hydroxyethyl and ##STR2## or form a saturated 5- or 6- membered ring; R.sub.4 is taken from the class consisting of lower alkyl of 1 to 5 carbon atoms, aryl or alkaryl of 6 to 9 carbon atoms, and aralkyl. The filters are useful in exposing dual response photosensitive materials with ultraviolet radiation sources which contain appreciable quantities of visible radiation.