Orient Chemical Industries, Ltd.

Seiko Epson Corporation

Makiko Matsui

Shuji Sugawara

Yoshihiro Sawatari

Tetsuya Aoyama

Hiroshi Fukumoto

Kazuhiko Kitamura

Tatsuya Yagyu

Sohko Itoh

Osamu Nakagawa

Nobuyuki Murai

A laser-transmissible composition comprises: A method for laser welding comprises:

Laser-transmissible composition and method of laser welding

To provide a black aqueous ink composition for excellent light and gas fastness, an ink set including the ink composition, and an ink jet recording process using the same, the black aqueous ink composition contains at least a trisazo dye represented by Chemical Formula 31.

Black aqueous ink composition, ink jet recording process using the same, and recorded matter

Trisazo compound

It is provided an aqueous pigment dispersion having improved dispersing stability in which carbon black shows appropriate initial dispersing property and long-term dispersing property to water, and carbon black particles are less susceptible to aggregation. Moreover, it is provided a raw material for ink-jet ink having improved printing density when alkali metal cation is substituted by potassium ion. The present invention is summarized as an aqueous pigment dispersion, which contains surface modified carbon black that is obtained by wet-oxidizing carbon black by using hypohalous acid and/or a salt thereof, and alkali metal cation, characterized in that concentration of the alkali metal cation is not more than 2% by weight.

Aqueous pigment dispersion and process for producing the same

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Hirakata, Japan

Makiko Matsui