Abstract A process for producing planographic prints wherein the printing plate is prepared from a heat-sensitive recording material formed of a support, an interlayer of a water-permeable hydrophilic colloid and an external water-permeable layer of at least one hydrophobic substance which melts on heating and in such molten condition is absorbed into the hydrophilic colloid interlayer by exposing such recording material to a pattern of heat to bring about differential absorption of the hydrophobic substance in the heated regions of the layer thereof to thereby expose portions of the hydrophilic layer in a pattern corresponding to the heat pattern. The planographic plate thus produced is inked with a generally hydrophilic printing ink selectively adhering to the hydrophilic portions, and the ink is transferred to a copy material to produce the desired print. Preferably, the hydrophobic substance is miscible or compatible in its molten state with the hydrophilic colloid of the interlayer. A particularly useful printing ink consists of a colored hydrophilic continuous phase in which is dispersed a lipophilic phase of coloration distinct from that of the hydrophilic phase.
subjecting said recording material to a pattern of heat to cause said hydrophobic substance in the heated regions to become absorbed into said water-permeable interlayer, thereby exposing portions of said hydrophilic layer in a pattern corresponding with the heat pattern;
Claim 2
Dependent Claim
23 words
A process according to claim 1, wherein said hydrophobic substance is miscible in its molten state with the hydrophilic colloid of said interlayer.
Claim 3
Dependent Claim
28 words
A process according to claim 2, wherein the interlayer comprises a polyacrylamide and the surface recording layer mainly contains a paraffinic microcrystalline wax melting between 40 and 120*C.
Claim 4
Dependent Claim
11 words
inking the heated external layer with a hydrophilic printing ink; and
Claim 5
Dependent Claim
11 words
transferring said ink to a copy material to produce said print.
Claim 6
Dependent Claim
11 words
A process according to claim 3, wherein the support is paper.
Claim 7
Dependent Claim
33 words
A process according to claim 1, wherein the printing ink consists of a colored hydrophilic continuous phase and a lipophilic phase distinct in color from said hydrophilic phase dispersed in said continuous phase.