Azo compounds and dye-type polarizing films or plates containing the same
AssigneesNippon Kayaku Kabushiki Kaisha, Polatechno Co., Ltd.
InventorYuichi Sadamitsu
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Abstract
Azo compounds whose free acid forms are represented by the general formula (1) are extremely useful as the dichroic dye to be used in polarizing plates which are excellent in polarization performance and endurance and reduced in the color cross-talk within the visible light region or in polarizers for liquid crystal projectors made by using them; (1) wherein R1 is sulfo, carboxy, or lower alkoxy and R2 is sulfo, carboxy, lower alkyl, or lower alkoxy, with the proviso that a case wherein both R1 and R2 are each sulfo is excepted; R3 to R6 are each independently hydrogen, lower alkyl, or lower alkoxy; and R7 and R8 are each independently hydrogen, amino, hydroxy, sulfo, or carboxy.
Claims11
An azo compound represented by the following formula (1) in the form of a free acid:
- [in the above formula, R1 represents a sulfo group, a carboxyl group or a lower alkoxyl group, R2 represents a sulfo group, a carboxyl group, a lower alkyl group or a lower alkoxyl group, with the proviso that a case where both R1 and R2 represent sulfo group is excepted, R3 to R6 each independently represents a hydrogen atom, a lower alkyl group or a lower alkoxyl group, and R7 and R8 each independently represents a hydrogen atom, an amino group, a hydroxyl group, a sulfo group or a carboxyl group].
Dependencies are inferred from the claim text.