Magnetic thermal transfer ribbon with aqueous ferrofluids
AssigneeNCR Corporation
InventorsJoseph D. Roth, Richard B. Moreland
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Abstract
There is provided by the present invention a coating formulation and thermal transfer ribbons which provide printed images which are readable by magnetic ink character recognition (MICR) devices. These formulations and ribbons minimize the use of organic solvents in employing wax, binder resin and an aqueous based ferrofluid with magnetic pigment particles. MICR readable printed images are also provided as are thermal printers which employ the ribbons.
Claims12
A thermal transfer medium comprising a flexible substrate and a thermal transfer layer positioned thereon having a softening point in the range of 50.degree. C. to 250.degree. C., said thermal transfer layer comprising wax, binder resin and a ferrofluid comprising magnetic particles with a hydrophilic coating in an amount sufficient to render the printed images therefrom recognizable by MICR devices, wherein said ferrofluid is derived from an aqueous ferrofluid.
A thermal transfer medium comprising a flexible substrate and a thermal transfer layer positioned thereon having a softening point in the range of 50.degree. C. to 250.degree. C., wherein said thermal transfer layer comprises wax, binder resin and a ferrofluid which provides 20-60 wt. % magnetic particles with a hydrophilic coating, based on total dry components of said thermal transfer layer wherein said ferrofluid is derived from an aqueous ferrofluid.
Dependencies are inferred from the claim text.