Friction body, writing instrument and writing instrument set
AssigneeThe Pilot Ink Co., Ltd.
InventorsYoshihiro Ito, Shouichi Ohkawa, Katsuyuki Fujita
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Abstract
A friction body that produces frictional heat allowing development, disappearance or change of color of handwriting formed with a writing instrument for producing thermochromic handwriting, with the friction body having a friction coefficient of 0.2 to 1.0 when rubbed against paper surface, and a writing instrument for use in forming thermochromic handwriting which is equipped with the friction body and a writing instrument set including the friction body and a writing instrument for use in forming thermochromic handwriting.
Claims7
A writing instrument for producing thermochromic handwriting comprising:
- a friction body that produces frictional heat allowing development, disappearance or change of color of handwriting formed with the writing instrument,
- wherein the writing instrument is configured to use a coloring agent being a microencapsulated pigment prepared by enclosing in microcapsules a reversibly thermochromic composition which contains at least three essential ingredients:
- (a) an electron-donating color-showing organic compound;
- (b) an electron-accepting compound;
- and (c) a reaction medium determining the temperature at which color reaction between (a) and (b) takes place, and whose color disappears by heating, the coloring agent having a completely decolorizing temperature within a range of from 50° C. to 80° C.,
- wherein the friction body has a friction coefficient of 0.4 to 0.8 when rubbed against a paper surface.
Dependencies are inferred from the claim text.