Pressure-sensitive copying material
AssigneeThe Wiggins Teape Group Limited
InventorsDavid J. Taylor, Margaret P. Templey, Ivan Sheiham
Life of this patent
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Abstract
Pressure-sensitive copying material utilizes a blend of rapid- and slow-developing chromogenic materials in vegetable oil solvent and an acid clay or synthetic inorganic color developer. The surface pH of the color developer is not more than 8.7, which gives rise to enhanced image intensity and fade resistance compared with the use of conventional higher color developer surface pH values.
Claims12
Pressure-sensitive copying material comprising a sheet support carrying isolated droplets of an oil solution of chromogenic materials, said droplets being confined within respective pressure-rupturable barriers, and, on the opposite surface of the same sheet or on a different sheet support, a coating of an inorganic colour developer material effective to develop the colour of the chromogenic materials in said solution on contact therewith, at least one of said chromogenic materials having the characteristic of developing colour immediately on contact with the colour developer, wherein:
- a) the oil solution comprises vegetable oil solvent;
- b) the solution of chromogenic materials includes at least one chromogenic material which is relatively slower in developing colour on contact with the colour developer than the above-mentioned immediately-developing chromogenic material(s);
- and
- c) the surface pH of the colour developer coating is not more than about 8.7.
A method of enhancing imaging performance of pressure-sensitive copying material comprising adjusting and/or maintaining the colour developer surface pH of a pressure-sensitive material to not more than about 8.7, said pressure-sensitive copying material comprising a vegetable oil solvent, at least one relatively slow-developing chromogenic material, and an inorganic colour developer material coating.
Dependencies are inferred from the claim text.