Migration imaging members

An imaging process which comprises (1) providing a migration imaging member which comprises (a) a substrate, (b) a conductive layer comprising indium tin oxide dispersed in a polymeric binder, (c) a siloxane film charge blocking layer comprising a hydrolysis reaction product of a silane of the formula ##STR15## wherein R.sub.1 is an alkylidene group, R.sub.2 and R.sub.3 are each, independent of the other, a hydrogen atom, an alkyl group, a phenyl group, or a poly(ethylene-amino) group, and R.sub.4,R.sub.5, and R.sub.6 are each, independent of the others, alkyl groups, said siloxane having reactive hydroxyl and ammonium groups attached to silicon atoms, and (d) a softenable layer comprising a softenable material and a photosensitive migration marking material;

• (2) uniformly charging the migration imaging member;
• (3) exposing the charged migration imaging member to a source of activating radiation in an imagewise pattern;
• (4) causing the softenable material to soften, thereby enabling the migration marking material to migrate through the softenable material toward the conductive layer in an imagewise pattern;
• (5) providing a printing plate precursor which comprises a base layer and a layer of photosensitive material selected from the group consisting of photohardenable materials and photosoftenable materials;
• and (6) exposing the printing plate precursor and the migration imaging member wherein the migration marking material has migrated toward the substrate in an imagewise fashion to radiation at a wavelength to which the photosensitive material on the printing plate precursor is sensitive, wherein substantially all of the radiation to which the printing plate precursor is exposed passes first through the migration imaging member, thereby causing the photosensitive material on the printing plate precursor to harden or soften in areas situated contiguous with light-transmissive areas of the migration imaging member, thereby forming an imaged printing plate.

An imaging process which comprises (1) providing a migration imaging member which comprises (a) a substrate, (b) a conductive layer comprising indium tin oxide dispersed in a polymeric binder, (c) a siloxane film charge blocking layer comprising a hydrolysis reaction product of a silane of the formula ##STR16## wherein R.sub.1 is an alkylidene group, R.sub.2 and R.sub.3 are each, independent of the other, a hydrogen atom, an alkyl group, a phenyl group, or a poly(ethylene-amino) group, and R.sub.4, R.sub.5, and R.sub.6 are each, independent of the others, alkyl groups, said siloxane having reactive hydroxyl and ammonium groups attached to silicon atoms, and (d) a softenable layer comprising a softenable material and a photosensitive migration marking material;

• (2) uniformly charging the migration imaging member;
• (3) exposing the charged migration imaging member to a source of activating radiation in an imagewise pattern;
• (4) causing the softenable material to soften, thereby enabling the migration marking material to migrate through the softenable material toward the conductive layer in an imagewise pattern;
• (5) providing a photosensitive film;
• and (6) exposing the photosensitive film and the migration imaging member wherein the migration marking material has migrated toward the substrate in an imagewise fashion to radiation at a wavelength to which the photosensitive material on the printing plate precursor is sensitive, wherein substantially all of the radiation to which the photosensitive film is exposed passes first through the migration imaging member, thereby forming an image on the photosensitive film.