Kabushiki Kaisha Pilot Corporation

Hirotaka Masuda

Kouichi Takayama

Satoru Ando

Tatsuyuki Nakatani

Takumi Kajiwara

Keishi Okamoto

Naoto Masushige

Yasuyuki Sugimoto

Yuki Nitta

Susumu Yamaguchi

Kunihiro Toyota

Akihiro Shiobara

Toshihide Kawasaki

An oil-based ball-point pen refill includes a ball-point pen tip in which a ball is held, in which the ball-point pen tip is mounted on a leading end of an ink housing cylinder, an ink composition including a coloring agent consisting of a dye, an organic solvent, and polyvinyl butyral resin is housed in the ink housing cylinder, the arithmetic mean roughness of a surface of the ball is 0.1 to 15 nm, the content of the polyvinyl butyral resin is 50 mass % or more based on the total mass of the whole resin, and an ink viscosity is 5000 to 50000 mPa&#xb7;s. In an oil-based ball-point pen, the refill is disposed in a barrel cylinder. An oil-based ball-point pen ink composition including a specific salt-forming dye, polyvinyl butyral resin, and an aromatic alcohol can be utilized in the refill.

Oil-based ball-point pen refill, oil-based ball-point pen, and oil-based ball-point pen ink composition

A writing instrument includes a pen point retaining member, a pen point that is attached to a first end of the pen point retaining member, an ink tank that is attached to a second end of the pen point retaining member, and an ink that is accommodated in the ink tank. The ink includes a lubricating interface layer-forming compound, and a carbonaceous film is formed on at least one of a surface of the ball or a contact portion of the ball holding portion with the ball.

Writing instrument

A ballpoint pen tip includes a ball and a ball holder for rotatably holding the ball. The ball includes a ball body and a first carbonaceous film formed so as to cover a surface of the ball body. The first carbonaceous film has carbon atoms and oxygen atoms bonded to some of the carbon atoms. The ratio of carbon atoms bonded to oxygen atoms to the total carbon atoms at a surface of the first carbonaceous film is equal to or greater than 0.1.

Ballpoint pen tip and ballpoint pen

Growing community of inventors

Kanagawa-ken, Japan

Hirotaka Masuda