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US 4,227,930 AGranted
Ball point pen, ink, and its eradicator system
AssigneeBurroughs Corporation
InventorAn-Chung R. Lin
Life of this patent
Estimating the term…
Abstract
Disclosed is a ball point ink pen, its ink and its eradicator. The ink is carried at one end of the pen and the eradicator portion is carried at the other. If an error is made, the pen can be reversed and the eradicator used to neutralize the ink. The ink also neutralizes the eradicator so that when one rewrites with the same ink, any remaining eradicator on the paper is neutralized and the original ink acts as fresh ink.
Claims3
A colored ink which can be eradicated after application, consisting of:
- a dye which remains colored in acid solution,
- a vehicle solution in which the dye will dissolve, and
- an acid with a PKa value smaller than 7.
Dependencies are inferred from the claim text.