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US 5,212,041 AGranted
Water developable, negative working overlay color proofing system utilizing water soluble polymeric diazonium compound and water insoluble, water swellable, binder resin
AssigneeHoechst Celanese Corporation
InventorStanley F. Wanat
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Abstract
This invention relates to water developable, negative working photosensitized sheet constructions which, upon exposure to an actinic radiation source through a screened image, can accurately reproduce said image. The construction is useful as a color proofing film which can be employed to predict the image quality from a lithographic printing process. The invention provides both overlay and transfer type proofing sheets which have good fingerprint resistance.
Claims9
A method for forming an overlay color proofing image on a transparent substrate which comprises
- A) providing a negative working, photosensitive, overlay color proofing film which consists essentially of, in order:
- i) a smooth transparent substrate;
- and
- ii) a photosensitive layer on said substrate, which photosensitive layer comprises a light sensitive, water soluble, negative working, polymeric diazonium compound, which diazonium compound is present in sufficient amount to photosensitize said layer;
- and a water insoluble, water swellable binder resin in sufficient amount to bind the layer components in a uniform film;
- and at least one colorant in sufficient amount to uniformly color said layer;
- and then
- B) imagewise exposing said photosesitive layer to sufficient actinic radiation to form a latent image;
- and then
- C) developing the latent image carrying photosensitive layer on said film with water alone to thereby remove the non-exposed areas of the photosensitive layer.
7 more elements
Dependencies are inferred from the claim text.