Mitsubishi Pencil Kabushiki Kaisha

Kazuhisa Kirita

Takao Koyama

Atsushi Iwasa

Toshimi Kamitani

An ink reservoir for a Writing instrument molded from a gas barrier resin such as polyvinyl alcohol, an ethylene vinyl alcohol copolymer resin, polyacrylonitrile, polyamide, a cellulose resin, polyester, polycarbonate and polystyrene, wherein a vapor-scarcely permeable coating layer having a vapor permeability (P) of 0.5 g/m* atm*24hr/25 &#x3bc;m or less at 40&#xb0; and 90% RH is formed on the above reservoir for a writing instrument. In this ink reservoir for a writing instrument, a gas barrier property is not reduced under the environment of high moisture even if a wall of the ink reservoir is relatively thin and a resin having an excellent transparency is used, and releasing of pressurized air in the ink reservoir and falling of the tip member are not caused.

Ink-storing body for writing utensil

A writing implement is provided and includes a pen element that feeds and retain ink from a writing implement body. The pen element has an ink leader, a writing part delivering ink from the ink leader portion and a viewer portion directly above with respect to the axial direction of the writing part allowing observation of the view in the writing direction. The present writing implement therefore allows easy observation of the view on the opposite side of the pen element as the pen point and allows the end point of the drawn line to be readily distinguished.

Writing implement

A free-ink type writing instrument having a temporary ink collector having a sectionally combed configuration, between an ink tank chamber and an writing tip and inside the front barrel, wherein all or part of the gaps between neighboring combed teeth for retaining ink in the temporary ink collector are set equal to 0.15 mm or smaller, and the ink tank is charged with an ink having a surface tension equal to 30 mN/m or lower at 25&deg; C.

Free-ink type writing instrument

A free-ink type writing instrument includes: an ink tank for holding ink; a temporary ink collector for temporarily retaining the ink flowing out from the ink tank; a partitioning wall separating the ink tank and the temporary ink collector; and a pen core disposed from the ink tank, penetrating through the partitioning wall and the ink collector so as to allow ink to flow out from the ink tank, and is characterized in that the storage volume Vc of the ink collector and the ink tank volume Vo satisfy the relation Vc&gE;0.18 Vo.

Growing community of inventors

Gunma, Japan

Kazuhisa Kirita