A photosensitive article comprises a substrate of a triacetate or other polyester film or paper coated with a layer of a photosensitive composition. The photosensitive composition includes at least one photodissociable choline compound sensitive to x-rays or radiation of shorter wave lengths, at least one image-forming compound capable of producing a dye by reaction with the dissociation products of the choline compound, a water soluble polymeric binder and a low melting point fatty acid salt for heat development. The photosensitive article can be used to produce an x-ray image by exposing the article image-wise to x-rays and heating the exposed article to develop the image.
An X-Ray sensitive composition including one or several photopolymerizable monomer or photocrosslinkable polymer systems and thermochromic substances which can be used in a dry X-Ray reproduction process. The process is based on the different dielectric constants and dielectric losses exhibited by a monomer and the corresponding polymer or a polymer and the crosslinked polymer and the reaction of certain thermochromic substances which exhibits a specific threshold temperature above which these substances change from a colorless form to a color stable form. The X-Ray sensitive element is exposed according to a pattern of X-Ray with spatial modulation providing an X-Ray image to form a latent image of polymerized or crosslinked zones and unpolymerized or non crosslinked zones. Exposed elements are developed by passing through a high frequency electrical field which raises the temperature of the polymerized or crosslinked zones by dielectric heating to above the color threshold temperature of the thermochromic substance. An Apparatus for carrying out the process is also described.
Rapid changes in absorption are made within the volume of a photosensitive transparent member that absorbs incident radiation to prevent the photocopy of a document, the original transparency being restored after discontinuance of the incident radiation.
A heat-sensitive recording composition comprising agglomerates which comprise a colorless or light-colored dye precursor, a color developer which reacts with the dye precursor upon heating to form a color, and a sensitizer and have an average diameter of 2-30 .mu.m; and a process for producing the composition are disclosed. This heat-sensitive recording composition is excellent in heat responsiveness and high in sensitivity. From the point of image stability, the agglomerates are preferably enclosed in microcapsules together with a polymer.
