Process for preparation of multicolor surprint proofs with silica overcoat
AssigneeE. I. Du Pont de Nemours and Company
InventorsAbraham B. Cohen, Roxy Fan
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Abstract
Process for preparation of multicolor surprint proofs from a composite photoimaged element, e.g., photopolymer element, having, in order, a sheet support, at least two colored photoimaged elements, and a layer of colloidal silica applied thereon, said colloidal silica being coated from a substantially aqueous dispersion wherein the colloidal silica has an average particle diameter of less than 500 nm and wherein at least 75% of the solids of said dispersion are silica, the silica layer being at least 20 mg/dm.sup.2 when dried. The multicolor proofs obtained contain a sharp image free from any three-dimensional effects and have a delustered, matte appearance which simulates printed press sheets.
Claims12
In a process for preparing a multicolor proof with improved image sharpness comprising a surprint having at least two nonplanar, nonsilver halide colored photoimaged elements on a support, the improvement comprising (a) coating on said photoimaged surprint at least one layer of colloidal silica from a substantially aqueous dispersion containing colloidal silica particles in a range of 10 to 60% by weight of solids wherein the colloidal silica has an average particle diameter of less than 500 nm and at least 75% of the solids of said dispersion are silica, and (b) drying the layer to a dried coating weight of at least 20 mg/dm.sup.2.
Dependencies are inferred from the claim text.