Sumitomo Chemical Company, Limited

Toru Ashida

Narutoshi Hayashi

Yoshiteru Ohta

Poly-azo compound selected from the group consisting compounds of the formula (I) and compounds of the formula (II), (wherein, Me represents copper, nickel, zinc or iron, A represents a naphthyl group having 1 to 3 sulfonic groups and further optionally having an alkyl group or alkoxy group, Rand Rrepresent each independently a hydrogen atom, alkyl group or alkoxy group, and Rrepresents an amino group or hydroxyl group.).

Poly-azo compound, and polarization film having said compound

The present invention provides a disazo compound of the formula (I) or a salt thereof wherein A represents 4-sulfophenyl or 6,8-disulfo-2-naphtyl, one of Rand Rrepresents hydrogen or methyl. The present invention also provides a dye-based polarizing film comprising a base material and the disazo compound of the formula (I) or the salt thereof contained in the base material. The disazo compound of the present invention provides a polarizing film, which is excellent in light resistance and initial polarizing performance, particularly light resistance when used as a polarizing element.

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Toyonaka, Japan

Toru Ashida