Water-based ink composition for ballpoint pen and ballpoint pen comprising the same
AssigneeThe Pilot Ink Co., Ltd.
InventorsNobuyuki Kitaoka, Yoshiaki Ono
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Abstract
A water-based ink composition for ballpoint pen, which comprises at least a colorant, water, a shear-thinning tackifier and a thickening inhibitor, wherein a ratio (x) of a viscosity after evaporation of 40 wt % of water from the total ink amount to an initial ink viscosity (as measured by EMD viscometer at 1 rpm and 20° C.) is 2 or less; and a ballpoint pen comprising the same.
Claims20
A water-based ink composition for ballpoint pen, which comprises at least a colorant, water, a shear-thinning tackifier and a thickening inhibitor,
- wherein a ratio (x) of a viscosity after evaporation of 40 wt% of water from the total ink amount to an initial ink viscosity (as measured by EMD viscometer at 1 rpm and 20 ° C) is 2 or less.
A water-based ink composition for ballpoint pen, which comprises at least a colorant, water, a shear-thinning tackifier, and a thickening inhibitor selected from the group consisting of compounds represented by the following formulas (1) to (6), an oligomer of N-vinyl-2-piperidone and an oligomer of N-vinyl-ε-caprolactam:
- (wherein, R1 represents a linear or branched C2-8 alkyl group or a cyclohexyl group),
- (wherein, R2 represents a linear or branched C1-7 alkyl group, a vinyl group or a cyclohexyl group),
- (wherein, R3 represents a linear or branched C1-6 alkyl group, a vinyl group or a cyclohexyl group),
- (wherein, R4 represents a linear or branched C1-10 alkyl group),
- (wherein, R5 represents a hydrogen atom, or a linear or branched C1-8 alkyl group), and
- (wherein, R6 represents a hydrogen atom or a linear or branched C1-6 alkyl group).
A water-based ink composition for capless ballpoint pen,
- which comprises at least a colorant, water, a shear-thinning tackifier and a thickening inhibitor selected from the group consisting of an oligomer of N-vinyl-2-pyrrolidone represented by the following formula (7), N-vinyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, and ε-caprolactam,
- wherein n is an integer from 2 to 20.
Dependencies are inferred from the claim text.