Toyo Ink Manufacturing Company

Motonori Ando

Takeshi Sato

Yasuharu Iida

Shinya Fujimatsu

Makoto Sakamoto

Shuji Miyazaki

An inkjet ink having sufficient water resistance on a recording sheet but having excellent re-solubility in an ink in a head portion and excellent ejection stability through a nozzle, the inkject ink comprising an aqueous liquid, a pigment and a water-soluble resin, the water-soluble resin being a terpolymer obtained from acrylic acid, styrene and .alpha.-methyl styrene and having a weight average molecular weight of 2,000 to 8,000 and an acid value of 90 to 130, and a process for the production of the inkjet ink, which comprises preparing a concentrated aqueous dispersion of a pigment and a terpolymer obtained from acrylic acid, styrene and .alpha.-methylstyrene, adding water and an additive to the concentrated dispersion to dilute the concentrated dispersion and maintaining the diluted dispersion at a temperature between 60.degree. C. and 80.degree. C. for 5 to 48 hours.

Inkjet ink and process for the production thereof

An optical recording medium which comprises an organic thin film layer containing at least one of phthalocyanine compounds, due to which high light absorptivity to laser beams and high recording sensitivity can be obtained. The optical recording medium provided by the present invention has high chemical and physical stability. There is also disclosed a process for the production of the optical recording medium.

Growing community of inventors

Tokyo, Japan

Motonori Ando