초록

An image producing system is provided, wherein an activator composition e.g. made up as a crayon or pencil, when contacted with paper substrate containing an azo color former yields an image by color change.

대표청구항 ▼

An image producing system, which comprises (a) a paper substrate impregnated or coated with a composition comprising an azo color former and (b) a solid activator composition in the form of a crayon or a pencil, said activator composition comprising a clay capable of activating said color former, a

An image producing system, which comprises (a) a paper substrate impregnated or coated with a composition comprising an azo color former and (b) a solid activator composition in the form of a crayon or a pencil, said activator composition comprising a clay capable of activating said color former, a solid organic carrier for the clay and an organic oily liquid solvent having low volatility, the color former having the general formula I [Figure] (I) in which R1, R2 and R3 each represents hydrogen, halogen, alkyl, alkoxy, aryloxy, alkoxycarbonyl, dialkylaminocarbonyl, acylamino, acyl(alkyl)amino, [Figure] in which Y1 and Y2 each represents alkyl or aryl, or in which Y1 and Y2 together represent an alkylene group; X1 is hydrogen or an alkyl group, X2 is an alkyl, cyanoalkyl or arylmethylene group or X1 and X2 together represent an alkylene group, X3 is an alkyl or aryl group and n is 1 or 2.