Kabushiki Kaisha Pilot Corporation

Takashi Ohno

Kazuhiro Yoshii

Teruaki Fukasawa

Kazuhiko Sasaki

Aya Okoshi

The present invention provides an aqueous writing ink composition capable of forming handwriting having both opacity and transparency, also a writing implement using the composition, and further a process for producing the composition. The aqueous writing ink composition according to the present invention comprises a white pigment, resin particles containing styrene-acrylonitrile, a colorant, and a polysaccharide. The content of the white pigment X %, that of the resin particles Y% and that of the polysaccharide Y% satisfy the conditions of0.1&#x2264;&#x2264;7,&#x2003;&#x2003;[1]0.5&#x3c;()/, and&#x2003;&#x2003;[2]10&#x2264;2.5+()&#x2264;40.&#x2003;&#x2003;[3]

Writing ink composition for aqueous ballpoint pen, ballpoint pen employing the same, and process for producing the writing ink composition for aqueous ballpoint pen

A retractable ballpoint pen is free from leakage of ink from its tip and ink back-flow attributable to shocks produced by retractable operation, and is capable of satisfactory writing performance. The retractable ballpoint pen has a ballpoint pen refill (,) having a ballpoint pen tip (,) disposed in a forward end of an ink-accommodating tube (,), a ball (,) held for free rotation in a forward end part of the ballpoint pen tip (,). The retractable ballpoint pen is provided with a retracting mechanism (,) for projecting a forward end of the ballpoint pen tip (,) and retracting the same through an open forward end (2a) of a barrel (,). A water-based ink (,) contained in the ink-accommodating tube (,) contains a thixotropic agent and has a viscosity at a rate of shear of 1.9 sec,at 20&deg; C. in the range of 900 to 2500 mPa&middot;s. A restricting passage (,) is formed in a passage for the water-based ink (,) contained in the ink-accommodating tube (,) to flow to the ball (,) and has a cross-sectional area measured perpendicular to the axis of the ink-accommodating tube (,) in the range of 0.4 to 0.8 mm,. The restricting passage (,) limits the flow of the water-based ink (,).

Push button type ballpoint pen

There is provided an ink capable of being used in a ballpoint pen, the ink comprising: 2 to 10% by weight of a dye, 20 to 30% by weight of a wetting agent, 5 to 10% by weight of urea, 0.2 to 0.4% by weight of cross-linked acrylic acid polymer, 0.05 to 0.2% by weight of xanthan gum, 1.0 to 5.0% by weight of sorbitol, and the balance, water.

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Tokyo-to, Japan

Takashi Ohno