Vesicular photographic film material and process for utilization of same

Claim 1

A METHOD OF FORMING A VESICULAR MIAGE OF REFRACTIVE CENTERS IN A FILM OF MATERIAL, SAID MATERIAL CONSISTING ESSENTIALLY OF A POLYMERIC CHLORINATED HYDROGEN CONTAINING VEHICLE AND A GAS FORMING COMPOUND IN AN AMOUNT NOT GREATER THAN 5%, BY WEIGHT OF SAID POLYMERIC VEHICLE, AND SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL AND ALKALINE EARTH METAL CARBONATES, BICARBONATES, OXALATES, AND TARTRATES, SAID METHOD COMPRISING: SELECTIVELY EXPOSING SAID MATERIAL TO SHORT-WAVE LIGHT TO CAUSE, IN SAID EXPOSED AREAS, A RELEASE OF HYDROGEN CHLORIDE FROM SAID POLYMERIC VEHICLE; AND DEVELOPING SAID EXPOSED AREA BY HEATING SAID MATERIAL TO A TEMPERATURE IN A RANGE FROM ABOUT 80*C. TO ABOUT 200*C. AND EFFECTIVE ONLY TO ENHACE A REACTION BETWEEN SAID GAS FORMING COMPOUND AND SAID HYDROGEN CHLORIDE OF SAID POLYMERIC VEHICLE, THEREBY PRODUCING ONLY IN THE EXPOSED AREAS CARBON DIOXIDE GAS WHICH CAUSE THE FORMATION OF VISIBLE BUBBLES IN THE EXPOSED AREAS TO SERVE AS SAID REFRACTIVE CENTERS.