High speed lithographic film element
AssigneeE. I. Du Pont de Nemours and Company
InventorsHerbert Gunther, Herbert Blank
Life of this patent
Estimating the term…
Abstract
High speed litho film in which short-life development accelerators such as cysteine methyl ester and its analogues are incorporated into the silver halide emulsion layer.
Claims8
A lithographic film element comprising a film support having one or more light-sensitive gelatino-silver halide emulsion layers coated thereon, each of which contains a development accelerator of the general formula:
- ##STR2## or a salt thereof, wherein each of R.sub.1 ;
- and R.sub.2 =H or C.sub.1 -C.sub.5 alkyl, each of R.sub.3 and R.sub.4 =H or -COOR, where R, R.sub.5, and R.sub.6 =C.sub.1 -C.sub.5 alkyl.
A lithographic film element consisting essentially of (a) a polyethylene terephthalate film support, (b) a light-sensitive gelatino-silver chlorobromide emulsion on said support, (c) an auxiliary underlayer between the film support and the emulsion, characterized in that the emulsion layer contains a development accelerator consisting of 2-dimethylamino-ethanethiol-1- or a salt thereof;
- and wherein the auxiliary underlayer contains a polyethylene oxide of M.W. circa 20,000, in an amount of sufficient to serve as a dot sharpening agent.
Dependencies are inferred from the claim text.