Negative-working diazotype photoreproduction
AssigneeJames River Graphics, Inc.
InventorEverett W. Bennett
Life of this patent
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Abstract
Negative-working diazography material is comprised of (i) at least one diazonium compound, (ii) at least one acid labile enolic, preferably phenolic blocked-coupler adapted to be converted in the presence of acid to an active azo-coupling component, and (iii) at least one light-sensitive acid progenitor. The diazonium compound can itself concurrently function as the acid progenitor, e.g., when complexed with a Lewis acid. Upon imagewise exposure to light, acid catalyst is photochemically liberated, thus unblocking coupler molecules such that dye image forms under alkaline developing conditions only where the material has been irradiated.
Claims61
A negative-working, light-sensitive diazography formulation comprising (i) at least one diazonium compound D capable of forming an organic azo dyestuff D--YOH or D--Y'OH, (ii) at least one acid labile blocked-coupler adapted to be converted in the presence of acid into an active azo-coupling species YOH or Y'OH, said blocked-coupler being chemically inert with respect to said diazonium compound D and having the structural formula Y--O--B, wherein Y--O-- is the residue of said active azo-coupling species YOH and further wherein the residue --O--B is an acid labile oxygen bridged blocking moiety B defining a radical selected from the group consisting of tertiary ether, acetal, ketal and MEM ether, and (iii) at least one light-sensitive acid progenitor adapted to photolytically generate an acid species capable of unblocking said blocked-coupler Y--O--B to convert same into said active azo-coupling component YOH, or rearrangement derivative Y'OH thereof.
A negative-working, light-sensitive diazography formulation comprising (i) at least one light-sensitive salt of a diazonium compound D capable of forming an organic azo dyestuff D--YOH or D--Y'OH, said salt being adapted to photolytically generate an acid species capable of unblocking the below blocked-coupler Y--O--B (ii) to convert same into an active azo-coupling component YOH or Y'OH, and (ii) at least one acid labile blocked-coupler adapted to be converted in the presence of said acid species into said active azo-coupling component YOH or rearrangement derivative Y'OH thereof, said blocked-coupler being chemically inert with respect to said salt of said diazonium compound D and having the structural formula Y--O--B, wherein Y--O-- is the residue of said active azo-coupling species YOH and further wherein the residue --O--B is an acid labile oxygen bridged blocking moiety B defining a radical selected from the group consisting of tertiary ether, acetal, ketal and MEM ether.
Dependencies are inferred from the claim text.