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US 5,464,470 AGranted
Color-changing marking composition system
AssigneeBinney & Smith Inc.
InventorsArmand Brachman, Keith Allison
Life of this patent
Estimating the term…
Abstract
A color-changing marking composition system, suitable for use in the form of crayons and pencils, comprising a first marking composition comprising wax, a dye, which is other than a Leuco dye and which is capable of changing color upon contact with a color change-inducing compound, and a solvent capable of solubilizing the dye; and a second marking composition comprising wax and a color change-inducing compound, which is capable of inducing a color change in a dye in a marking composition with which it is brought in contact.
Claims32
A color-changing marking composition system comprising:
- (a) a first marking composition comprising a wax, a dye which is other than a Leuco dye and which changes color when contacted with a color change-inducing compound, and a solvent capable of solubilizing the dye;
- and
- (b) a second marking composition comprising a wax and a color change-inducing compound which when contacted with the dye induces a color change in the dye.
Dependencies are inferred from the claim text.