Mitsubishi Pencil Kabushiki Kaisha

Mitsubishi Pencil Company, Limited

Takao Koyama

Kazuhisa Kirita

Atsushi Iwasa

Toshimi Kamitani

Takahiro Osada

Takamasa Kawakubo

Hitoshi Nakamura

Tadashi Koriki

Yoshiomi Konose

Kyoko Kobayashi

Makoto Ono

Kei Omoto

Yasuaki Ogiwara

Akira Fukai

Atsushi Sato

In a writing instrument in which an ink for a writing instrument such as a water-based ink and an oil-based ink impregnated into an ink occlusion body in a barrel is fed to a pen tip in a writing part, in order to provide a writing instrument in which a sign of exhausting the ink can readily and surely be detected, the above writing instrument is provided with a structure in which the ink impregnated into the ink occlusion body in the barrel is fed to the pen tip in the writing part, wherein the ink impregnated into the ink occlusion body described above is fed to the pen tip via an ink guiding feed having visibility, and a sign of exhausting the ink fed from the ink occlusion body is detected by visually observing the ink guiding feed described above via a visible part formed in the barrel.

Writing instrument

A refill for a correction pen is constructed of a molded article of a polyamide resin obtained from monomers having an aromatic ring or a naphthene ring, a molded article of a blend of two or more kinds of polyamide resins, or a molded article having a multi-layered structure of two or more layers whose innermost layer in contact with the correction fluid is constituted of a polyamide resin. The applying part of a refill unit mounted on a ballpoint type applicator having a pressurizing mechanism in linkage with clicking action is formed by press fitting the rear end of a ballpoint pen tip having a rotatable ball to the attachment portion at the front end of an ink reservoir and a metal tube is squeezed to cover the outer periphery of the attachment portion at the front end of the ink reservoir to which the tip is fitted.

Refill for correction pen and refill unit

A medium for electrophoretic display using a liquid for electrophoretic display which can reversibly change a visible state by action of an electric field includes a medium comprising each independent structures of microcapsules or cells filled with a liquid for electrophoretic display comprising at least alkylpolyetheramine having a structural unit represented by a specific structural formula, one or more kinds of fine particles, a dispersant and a dispersion liquid medium, wherein the fine particles contain fine particles subjected to surface treatment for making lipophilic. Also, an electrophoretic display device includes a display device comprising a pair of substrates in which a light-transmitting electrode is formed on at least one substrate and the medium for electrophoretic display described above between the substrates. The electrophoretic display medium and the electrophoretic display device each using the above display liquid for electrophoretic display have a high contrast on a display face and can display the contrast with high reliability even in repetitive display, and they are excellent as well in a response.

Liquid for electrophoretic display, display medium and display device using the same

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 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.

Provided is a free ink type writing instrument having an ink tank part for storing an ink, in which an amount of the ink can visually be observed. The free ink type writing instrument is characterized by that the whole or a part of an internal surface part in contact with the ink in the ink tank part has a smaller critical surface tension than a surface tension of the ink, and a contact angle between the ink and the whole or a part of the internal surface part in contact with the ink in the ink tank part is 30&deg; or more at a temperature of 25&deg; C.

A ball point pen filled with an erasable ink which comprises a resin or rubber having a filming temperature of 0.degree. C. or lower or a glass transition temperature of 0.degree. C. or lower, pigment particles and water. The erasability and the writing feeling are improved by further blending the ink with a gelatinizer and a lubricant.

Ball point pen filled with erasable ink

A free ink type writing instrument using an ink containing an organic solvent as a main solvent, wherein a temporary ink reservoir member has a larger critical surface tension than a surface tension of the ink, and an absolute value of a difference between values of solubility parameters of a material constituting the temporary ink reservoir member and a solvent contained in the ink is 1 or more.

Provided is a non-erasable pencil lead for a natural pencil and a mechanical pencil, characterized in that the pores of a baked pencil lead are impregnated with an unsaturated compound containing an unsaturated group having an iodine value of at least 130 or more, wherein an antioxidant, an oxidative polymerization catalyst and/or a photosensitizer can be added in addition to the unsaturated compound.

Non-erasable pencil lead

A process for coating a carbonized material with metal is disclosed, wherein a chlorine-containing resin mixture is coated with Cr or Fe-Cr alloy to a thickness of substantially several microns. The coated product is then heated in an inactive atmosphere to carbonize the resin mixture. The process sufficiently coats a metal onto a carbonized material using relatively simple steps.

Process for coating carbonized material with metal

A process for producing a carbon heat generator is disclosed including the steps of uniformly dispersing one or more types of metal compounds capable of forming a vitreous film upon oxidation in a moldable composition, molding the resultant dispersed composition, precarbonizing the molded composition, and then carbonizing the composition in a nonoxidative atmosphere to form a carbon heat generator having an oxidation preventive glass film. The oxidation of the metal compound exposed on the surface of the molded composition by the use of an oxidative atmosphere forms a vitreous film which prevents oxygen from diffusing in the interior thereof. The film so produced can form a new glass film on a damaged portion by a self-recovery effect if a pinhole or a crack occurs in the glass film. Thus, the process does not cause external appearance and weight differences before and after heat generating.

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Fujioka, Japan

Takao Koyama