US T883031 I4
Description (OCR text may contain errors)
DEFENSIVE PUBLICATION UNITED STATES PATENT OFFICE Published at the request of the applicant or owner in accordance with the Notice of Dec. 16. 1969, 869 O.G. 687. The abstracts of Defensive Publication applications are identified by distinctly numbered series and are arranged chronologically. The heading of each abstract indicates the number of pages of specification. including claims and sheets of drawings contained in the application as originally filed. The files of these applications are available to the public for inspection and reproduction may be purchased for 30 cents a sheet.
Defensive Publication applications have not been examined as to the merits of alleged invention. The Patent Ofiice makes no assertion as to the novelty of the disclosed subject matter.
PUBLISHED FEBRUARY 23, 1971 T883,031 DIRECT POSITIVE SILVER HALIDE EMULSIONS SENSITIZED WITH CHLORANIL, 1,2-0RTHO- QUIN ONE, OR POLYNUCLEAR HETEROCYCLIC COMPOUNDS Paul B. Gilman, Jr., and Frederick J. Rauner, both of Kodak Park, Rochester, N.Y. 14650 Filed July 9, 1970, Ser. No. 53,629 Int. Cl. G03c J/28 U.S. Cl. 96-107 No Drawing. 25 Pages Specification Direct positive photographic silver halide emulsions, such as those described in Berriman U.S. Pat. 3,367,778 issued Feb. 6, 1968 or lllingsworth U.S. Pat. 3,501,307 issued Mar. 17, 1970, are sensitized with chloranil, a 1,2- orthoquinone, an acridine, an acridone or a thiacridone. Preferred sensitizers include chloranil, 4-phenyl-1,2-orthoquinone, and compounds having one of the following formulas:
wherein R represents a hydrogen atom, a phenyl group or an aminophenyl group; R represents an alkoxy group of :1 nitro group; R represents a hydrogen atom or a phenoxy group; R represents a hydrogen atom, a halogen atom or a nitro group; R represents a hydrogen atom, a halogen atom, or an alkyl group; R represents a hydrogen atom or an alkoxy group; R R and R each represents a hydrogen atom, a halogen atom or an alkoxy group; and, R represents alkyl or aryl. A typical direct positive silver halide emulsion contains 4-phenyl- 1,2-orthoquinone or 7-tetramyl-3-chloro-thioacridine or 3,7 dichlorothioacridone or 2-chloro-7-methoxy-5-phenoxyacridine as sensitizer and S-m-nitrobenzylidenerhodanine as electron acceptor.