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US 3,940,275 AGranted
Record material and marking liquid
AssigneeNCR Corporation
InventorsBruce W. Brockett, Ralph L. Marzocco, Fredrick D. Weaver
Life of this patent
Estimating the term…
Abstract
A colorless marking liquid comprising a vehicle in which is dissolved at least two colorless reactants each exhibiting its own distinctive color on reaction with an acidic record material sensitizing substance, the liquid yielding an apparent blue hue on record material sensitized with an acidic material. The resulting blue print provides excellent reproduction capabilities when copied by xerographic processes.
Claims3
In a substantially colorless but colorable marking liquid composition consisting essentially of an organic oil solution of a colorless reactant;
- the improvement comprising, as said reactant, (1) 1.7 to 2 weight percent of 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide;
- (2) 0.0 to 1.5 weight percent of 3,7-bis(dimethylamino)-10-benzoyl phenothiazine;
- (3) 1.1 to 1.5 weight percent of a mixture of 2'-anilino-6'-diethylamino-3'-methylfluoran and 3,3-bis(1-ethyl-2-methylindol-3-yl)phthalide or 1.1 weight percent 2' anilino-6'-dielhylamino-3'-methylfluoran wherein a ratio, by weight, of component (3) to components (1) and (2) is less than 1 to 1 and wherein the combination of components, when colored, yields an apparent blue-colored mark which absorbs substantially all of the visible spectrum between 400 and 500 millimicrons.
Dependencies are inferred from the claim text.