Method of making a lithographic master and method of printing therewith

Claim 1

The method as described in claim 1 wherein said exposing step is carried out through said donor substrate and said hydrophilic receiver sheet comprises a lithographic paper substrate.

Claim 6

A method of preparing a lithographic printing master which comprises rendering a hydrophobic electrically photosensitive imaging composition coated on the surface of a donor support substrate, fracturable in response to actinic electromagnetic radiation and electric field by applying thereto an activator for said composition, placing a hydrophilic receiver sheet over said photoresponsive composition, exposing said imaging composition to a pattern of actinic electromagnetic radiation through the surface of at least one of said donor substrate and receiver sheet while an electric field is applied across said imaging composition, said surface being transparent to said radiation, and separating said receiver sheet from said donor substrate, said hydrophilic receiver sheet having formed on the surface thereof a hydrophobic waxy image, to produce said lithographic master.

Claim 8

A method of preparing a lithographic printing master which comprises rendering a hydrophobic electrically photosensitive imaging composition coated on the surface of a donor support substrate, fracturable in response to actinic electromagnetic radiation and an electric field, placing a receiver sheet over said imaging composition, exposing said imaging composition to a pattern of actinic radiation through the surface of at least one layer of said donor substrate and receiver sheet while an electric field is applied across said imaging composition, said surface being transparent to said radiation, separating said receiver sheet from said donor substrate with the exposed portion of said imaging composition being retained on one of said donor and receiver layers while the unexposed portion is retained on the other of said layers and transferring at least one of said formed images to the surface of a hydrophilic substrate to produce said printing master.

Claim 12

A method of making multiple copies from a lithographic duplicating master which comprises: a. selectively exposing at least one surface of a manifold set to actinic radiation while said set is subjected to an electric field, said surface being transparent to said radiation, said manifold set comprising a frangible waxy hydrophobic electrically photosensitive imaging composition interpositioned between a donor substrate and a hydrophilic receiver sheet; b. separating said hydrophilic receiver sheet from said donor substrate whereby said imaging composition fractures in imagewise configuration to provide adhering to the surface of said receiver sheet a waxy hydrophobic image of said imaging composition; c. dampening said receiver sheet; d. applying to the surface of said image bearing hydrophilic receiver sheet a lithographic ink, said ink being distributed thereon conforming to said image; e. contacting said ink surface with a copy sheet thereby transferring an imprint of said image To said sheet; and f. repeating steps (d) and (e) until the desired number of copies are produced.

Claim 14

A method of making multiple copies from a lithographic printing master which comprises: a. selectively exposing at least one surface of a manifold set to electromagnetic radiation, while said set is subjected to an electric field, said surface being transparent to said radiation, said manifold set comprising a frangible hydrophobic electrically photosensitive imaging composition interpositioned between a donor substrate and a receiver sheet; b. separating said receiver sheet from said donor substrate whereby said imaging composition fractures in imagewise configuration to provide adhering to the surface of said receiver sheet an image of said imaging composition and said donor substrate having adhered to its surface an image complimentary to that on said receiver sheet; c. transferring at least one of said formed images to the surface of a hydrophilic substrate; d. dampening said hydrophilic substrate; e. contacting said image successively with a lithographic ink and with the surface of a transfer sheet thereby transferring an ink image to said transfer sheet; f. contacting said transfer sheet with the surface of a copy sheet whereby an ink image is transferred to said copy sheet; and g. repeating steps (d), (e) and (f) until the desired number of copies are produced.