Physical development utilizing 1-phenyl-3-pyrazolidone or a benzene diamine combined with a polyhydroxybenzene in acidic medium

Abstract

Abstract THIS INVENTION RELATES TO PHYSICAL DEVELOPMENT OF A PHOTOGRAPHIC REPRODUCTION SYSTEM WITH A PHYSICAL DEVELOPER. THE STEP OF PHYSICAL DEVELOPMENT COMPRISES CONTACTING AN EXPOSED PHOTOSENSITIVE LAYER CONTAINING THE OXIDIZING COMPONENT OF A CHEMICAL REDOX SYSTEM, SUCH AS SILVER NITRATE, WITH THE REDUCING COMPONENT OF THE REDOX SYSTEM WHERE THE REDUCING COMPONENT IS A MIXTURE OF A SLOW-ACTING REDUCING AGENT AND A FAST-ACTING REDUCING AGENT. THE USE OF A MIXED REDUCING AGENT AS DESCRIBED PERMITS DEVELOPMENT OF IMAGES OF IMPROVED DENSITY AND CONTRAST BECAUSE DEVELOPMENT INITIATES AND TAKES PLACE WITHIN THE PHOTOSENSITIVE LAYER RATHER THAN ON ITS SURFACE OR BEYOND ITS SURFACE AS TYPICALLY ENCOUNTERED WITH PRIOR ART DEVELOPERS. AN OVERALL PROCESS IN ACCORDANCE WITH THE INVENTION COMPRISES SELECTIVELY EXPOSING THE REPRODUCTION SYSTEM TO ACTIVATING RADIATION AND DEVELOPING IN THE MANNER ABOVE DESCRIBED. A PORTION OR ALL OF THE OXIDIZING COMPONENT OF THE REDOX SYSTEM MAY BE CONTAINED WITHIN THE PHOTOSENSITIVE LAYER AT THE TIME OF EXPOSURE TO GIVE A DIRECT READ-OUT OR IT IS POSSIBLE TO APPLY ALL OF THE OXIDIZING COMPONENT AT A TIME SUBSEQUENT TO EXPOSURE FOLLOWED BY CONTACT WITH THE REDUCING PORTION OF THE REDOX SYSTEM. A PHOTOSENSITIVE LAYER COMPRISING A PHOTOCONDUCTOR THAT BECOMES REVERSIBLY ACTIVATED UPON EXPOSURE TO ACTIVATING RADIATION IS PREFERRED. TITANIUM DIOXIDE HAVING A PARTICLE SIZE LESS THAN ABOUT 250 MILLIMICRONS AND WHICH HAS BEEN HEATED AT A TEMPERATURE BETWEEN ABOUT 200* C. AND 950* C. IS THE PREFERRED PHOTOCONDUCTOR.

Inventors

• 👤 J Manhardt

Bibliographic Details