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Abstract

Abstract A RELIEF IMAGE IS FORMED BY EXPOSING TO A HEAT PATTERN A HEAT-SENSITIVE RECORDING MATERIAL COMPRISING A GENERALLY UNIFORM LAYER CONSISTING ESSENTIALLY OF A CONTINUOUS PHASE OF HYDROPHILIC BINDING AGENT HAVING DISTRIBUTED THERETHROUGH IN SUBSTANTIALLY DISCRETE, GENERALLY CONTIGUOUS RELATIONSHIP A DISPERSED PHASE OF PARTICLES CONSISTING ESSENTIALLY OF A HYDROPHOBIC THERMOPLASTIC POLYMER, IN A WEIGHT RATIO RELATIVE TO THE BINDER PHASE IN EXCESS OF 1:1, THE HEAT OF SUCH PATTERN BEING SUFFCIENT TO AT LEAST PARTIALLY COALESCE THE POLYMER PARTICLES IN THE HEATED AREA AND THEREBY SIGNIFICANTLY REDUCE THE FLUID PERMEABILITY OF THE LAYER IN THE HEATED REGIONS THEREOF. AND THEREAFTER DEVELOPING THE EXPOSED HEAT-SENSITIVE RECORDING MATERIAL BY WASHING OFF THE UNHEATED REGIONS THEREOF THE SUBSTANTIALLY UNREDUCED PERMEABILITY WHILE LEAVING THE REMAINING PORTIONS OF THE COALESCED PARTICLES TO FORM THE RELIEF IMAGE, IS GIVEN A PROTECTIVE COVERING BY APPLYING TO THE RELIEF IMAGE WITH PRESSURE A HYDROPHILIC COLLOID LAYER CARRIED ON A TEMPORARY HYDROPHOBIC SHEET SUPPORT, AND STRIPPING OFF THE TEMPORARY SHEET SUPPRT SO AS TO LEAVE THE COLLOID LAYER SUPERIMPOSED UPON THE RELIEF IMAGE. PREFERABLY, THE COLLOID PROTECTIVE LAYER HAS A THICKNESS OF 3-10U AND PREFERABLY THE HYDROPHILIC COLLOID LAYER IS WET WITH AN AQUEOUS LIQUID WHICH CAN CONTAIN A SOFTENING AGENT FOR THE HYDROPHILIC COLLOID WHEN THE COLLOID LAYER IS APPLIED TO THE RELIEF LAYER.

Inventors

• 👤 Daniel Alois Claeys

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