Improvements in or relating to a process of Thermographic Copying

• Main Authors: MARCEL NICOLAS VRANCKEN, ALEXANDER RIEBEL
• Format: Patent
• Language: English
• Published: 11.06.1969
• Subjects: COLOUR PRINTING; LINING MACHINES; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING,INKING, DAMPING, OR THE LIKE; PERFORMING OPERATIONS; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM; PRINTING; PRINTING PLATES OR FOILS; PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; STAMPS; TRANSPORTING; TYPEWRITERS

1,154,902. Thermographic reflex processes. GEVAERT-AGFA N. V. June 22, 1966 [June 22, 1965; Nov.26, 1965], Nos.26467/65 and 50442/65. Heading G2C. A thermographic reflex proeess which comprises reflex exposing a heat-sensitive material comprising a layer of gelatine or a gelatine derivative and a substance which absorbs radiation and converts it into heat to an original which imagewise reflects radiation used in the exposure so that the gelatine is heated imagewise heated and becomes more water-absorptive or water-soluble in the heated areas. The exposure used is preferably a flush exposure of less than 10-1 seconds consisting mainly of visible light and this light is absorbed by the substance preferably carbon black or colloidal silver, in the gelatine layer. The exposed material may be developed by (i) rubbing with water to remove the heated areas, contacting the developed material with a dye layer which adheres to the remaining gelatine to produce a spirit duplicating master. (ii) dipping in water and transferring the heated gelatine areas on to Japan paper to form a stencil (iii) transferring the heated gelatine areas to a receptor sheet and then contacting this transfer sheet with a dye layer to produce a spirit duplicating master. Multi-colour originals may be produced by using materials containing cyan, magenta and yellow dyes in the gelatine layers. Preferably the gelatine used is that disclosed in Specification 985,933.