Sakura Color Products Corporation

Tadaaki Ito

Yasunori Nakatani

Shigeyasu Inoue

Atsushi Ito

Hiroyoshi Yamamoto

The present invention provides an aqueous ink composition for ball-point pens comprising a titanium oxide as a white pigment, a viscosity modifier and flat-shaped resin particles. The color of the aqueous ink composition can be adjusted by coloring agents (such as a pigment). The viscosity of the aqueous ink composition is 100 cps to 20,000 cps at 20&deg; C. The average particle diameter of said flat-shaped resin particles is 0.05 &mgr;m to 10 &mgr;m and the content thereof is 1% by weight to 35% by weight with respect to the total amount of the aqueous ink composition. The content of the titanium oxide is 5% by weight to 55% by weight with respect to the total amount of the aqueous ink composition. As a viscosity modifier, a polysaccharide is used and the content thereof is 0.1% by weight to 2% by weight with respect to the total amount of the aqueous ink composition.

Aqueous ballpoint ink composition

A ball for a ball-point pen is provided which is composed of a sintered material obtained by sintering hard particles and having an average inter-particle diameter of not greater than 0.2 &mgr;m. The gaps between the hard particles are very small and, therefore, very few minute fragments of the hard particles are exposed from binder metal portions on the surface of the ball and fall off to act as an abrasive during use of the ball-point pen. Thus, abrasion of a pen tip body and sinkage of the ball into the pen tip body can be prevented.

Ball for ball-point pen

The present invention provides an aqueous pigment dispersion composition for electro-deposition color coating of an aluminum or aluminum alloy oxide film, the composition comprising an organic white pigment as an essential component thereof. The organic white pigment comprises large-diameter particles which are insoluble in a water-soluble organic liquid and/or water and exhibit a non-skinning property and a sufficient concealing power on an aluminum or aluminum alloy oxide film. More specifically, the organic white pigment particles preferably have an average particle diameters of at least 0.3 .mu.m and a reflective index of at least 1.4. The use of the aqueous pigment dispersion composition for electro-deposition coating ensures formation of a less lustrous, less transparent and highly weather-resistant coating film for coloration of an aluminum or aluminum alloy oxide film.

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Osaku-fu, Japan

Tadaaki Ito