Kabushiki Kaisha Pilot Corporation

Horiba Advanced Techno, Co., Ltd.

Taro Tozuka

Yuji Nishio

Akio Ishii

Hisashi Nakamura

The present invention provides a water-based ink composition for a ballpoint pen that is less likely to cause bleeding of a written trace in writing, provides a favorable written trace without causing no blurring or line splitting, and excels in the storage stability of the ink composition; and a water-based ballpoint pen using the ink composition. A water-based ink composition for a ballpoint pen comprising water, a coloring agent, a copolymer having a specific structure; and a water-based ballpoint pen using the ink composition.

Water-based ink composition for ballpoint pen and water-based ballpoint pen using the same

In order to improve the endurance of this internal solution for a reference electrode beyond that in the prior art, the solution is made to contain a copolymerized material of a crosslinker having a plurality of non-acrylamide functional groups, and a non-acrylamide monofunctional hydrophilic monomer.

Internal solution for reference electrode, reference electrode, and glass electrode

The invention aims at providing a solid writing material that does not adversely affect the color changing property of script and can obtain sufficient strength. This aim is achieved by the solid writing material that includes: a reversible thermochromic microcapsuled pigment encapsulating a temperature-sensitive color-changeable color-memorizing composition; an excipient; and a resin; the temperature-sensitive color-changeable color-memorizing composition including at least (a) an electron-donating coloring organic compound, (b) an electron accepting compound and (c) a reaction medium effecting reversibly an electron transfer reaction between the (a) and (b) components in a specific temperature range; wherein the excipient or the resin includes a styrene-structure-containing polymer.

Solid writing material

A magnetic display panel that excels in display and erasure performance, being free from any change of writing and display performance even upon repetition of display and erasure and that facilitates inhibition of thixotropic property and specific gravity control for dispersion medium vs. magnetic display substance, etc., ensuring low toxicity and low pollution. In particular, a magnetic substance display panel comprising a dispersion with yield value composed mainly of a magnetic display substance, water and an aqueous thickener and a support holding the dispersion, characterized in that the aqueous thickener is at least one member selected from among a crosslinked acrylic acid copolymer, a crosslinked maleic anhydride copolymer, a thickening polysaccharide and a polyvinylalkylamide.

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Hiratsuka, Japan

Taro Tozuka