Imaging peel apart element employing two photohardenable layers

A multi-layered sheet construction capable of reproducing both positive and negative forms of a photographic transparency image which comprises successive adherent layers comprising:

• (a) A flexible, transparent, substantially gas impermeable top support capable of transmitting radiant energy therethrough and having adhered to one surface thereof;
• (b) A first photosensitive composition layer which comprises (i) a major amount of a light-sensitive, substantially gas generating diazonium substance and may contain (ii) minor amounts of resinous materials, such that said photosensitive composition disintegrates with a concurrent forced expulsion of gas upon exposure to an ultraviolet energy supply to which it is reactive, said photosensitive layer having adhered thereto;
• (c) An image forming layer comprising a resinous material which is capable of being imagewise separated upon the application of dissociative shearing forces, said image forming layer having adhered thereto;
• (d) An adhesive layer comprising a resinous material capable of being imagewise separated upon the application of dissociative shearing forces, said adhesive layer comprising:
• I. From about 25% to 100% light sensitive composition comprising (i) up to 10% photoinitiator;
• (ii) at least 90% material capable of hardening, crosslinking or polymerizing upon being blended with said photoinitiator and exposure to ultraviolet radiation;
• and
• II. Up to 75% of a material selected from the group consisting of binding resins and fillers;
• said adhesive layer having adhered thereto;
• (e) A bottom support having a substantially regular surface, whereby upon exposure of the multi-layered sheet construction to an ultraviolet radiant energy source through a photographic transparency from the direction of the top transparent support, said energy causes said first photosensitive composition to spontaneously, outwardly expel a gas so as to exert outward forces on said top support and said image layer at the exposed locations, thereby forming an imagewise bubble system which is visible through said top support, said radiant energy is transmitted through said image forming layer and reaches and reacts with said adhesive layer, causing the adhesive layer light-sensitive composition to harden at the thusly exposed locations, such that upon a subsequent separation of said bottom and said top supports, solely by means of peeling forces, an imagewise shearing of the image layer and the adhesive layer is effected along their respective interfaces which are in underlying registration, with an interface formed between the exposed and unexposed portions of the first photosensitive layer;
• and a negative reproduction of the transparency image is thereby produced in the form of said bottom support, the exposed negatively imagewise separated adhesive layer attached to said bottom support, and the negatively imagewise separated image forming layer attached in registration with said negatively imagewise separated exposed adhesive layer, and a positive reproduction of the transparency image is simultaneously produced in the form of said top support, the unexposed first photosensitive composition layer attached to said top surface, the positively imagewise separated image forming layer material attached to and in registration with said unexposed first photosensitive layer, and the unexposed positively imagewise separated adhesive layer attached in registration with the positively imagewise separated image forming layer.