PASTEL TONE REVERSIBLY THERMOCHROMIC INK COMPOSITION FOR WRITING UTENSIL, AND WRITING UTENSIL AND WRITING UTENSIL SET USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a pastel tone reversibly thermochromic ink composition for writing utensils, in which handwriting formed by writing on a colored writing surface has a pastel tone color, and which shows such good erasability of handwriting that a clouded residual image is not visible in the handwriting part when handwriting is decolored, and to provide writing utensils and a writing utensil set using the ink composition.SOLUTION: The pastel tone reversibly thermochromic ink composition for writing utensils contains: a microcapsule pigment that changes from chromatic color to achromatic color and has an average particle size of 0.01-1.0 μm; and a microcapsule pigment that changes from white color to achromatic color and has an average particle size of 0.01-1.0 μm; wherein a weight ratio between the microcapsule pigment that changes from chromatic color to achromatic color and the microcapsule pigment that changes from white color to achromatic color is 1:1 to 1:25. Then, the writing utensils 1 and the writing utensil set using the ink composition are provided.