Abstract: Novel dot enhancing compositions are disclosed for use in high contrast negative-working image-forming systems. The compositions include compounds of the general formula: ##STR1## wherein R.sub.1 is an aromatic group, A is a substituted or unsubstituted aromatic nucleus, and the two carboxyl groups specifically depicted in general formula (I) are each bound to a different carbon atom of said aromatic nucleus.The dot enhancing compositions may be incorporated into a silver halide photographic emulsion or into another hydrophilic colloid layer of a photographic material, or into a developing solution or, alternatively, into both. The dot enhancers of the invention improve density and contrast of images formed, as well as providing a harder, smoother, better formed dot for use in letter press and offset lithography.
June 27, 1988
Date of Patent:
November 21, 1989
Polychrome Corp., Dainippon Ink & Chemicals, Inc.
Yasuhiko Kojima, John Pilot, Burton H. Waxman
Abstract: Radiation sensitive compositions comprising acrylic or methacrylic acid esters with decreased oxygen inhibition attained by use of minor amounts of N,N'-diorgano dicarboxamide additives. The acrylated ester compositions are suitable for ultraviolet curable coatings.
Abstract: Quinone diazide derivatives of adamantane, and especially quinone diazide derivatives of 1,3-dialkyl-5,7-bis(hydroyphenol) adamantanes, have been found to provide unique properties when coated on metal substrate in the preparation of both positive and negative working lithographic plates. The improved lithographic plates are characterized by enhanced speed, coating oleophilicity, alkali resistance, developer latitude and development speed.
Abstract: An improved planographic printing plate comprised of a metal substrate, a sealing layer, an interlayer formed from a monomer or polymer of an organic compound having at least one cationic, quaternary substituted ammonium group, and a photosensitive layer on the surface of the interlayer. The printing plates are water developable and characterized by cleaner non-imaging areas during printing operations. The method of preparing such planographic printing plates is also described and illustrated.
Abstract: A method is provided for electrolytically graining an aluminum lithographic plate to produce a grained surface with a honeycomb topography, non-directional grain structure, and a substantially reduced production of smut. The reduction of smut is achieved by utilizing an alternating current of higher frequencies, generally in the range of approximately 140 to 400 Hz.
September 28, 1984
Date of Patent:
October 22, 1985
Jen-chi Huang, Gregory Von Gruenberg, Donald J. Riley