Achromatic dye-based highly-transmissive polarization element, and polarization plate
AssigneesNippon Kayaku Kabushiki Kaisha, Polatechno Co., Ltd.
InventorNoriaki Mochizuki
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Abstract
A polarization element, which is obtained from a base material containing a dichromatic dye formed from an azo compound, is characterized in that the single-body transmittance is 35-60%, and a* and b* values, which are acquired for a polarization element or a polarization plate using JIS⋅Z⋅8729, have an a* and b* absolute value that is: less than 1 in a single-body transmittance measurement; less than 2 when two sheets of the base material are arranged parallel to the absorbing axis direction and the a* and b* values are measured; and less than 2 when two sheets of the base material are arranged orthogonal to the absorbing axis direction and the a* and b* values are measured.
Claims14
A polarization element comprising a stretched base material containing a dichroic dye that is an azo compound, wherein the polarization element is characterized in that:
- a* value and b* value of a hue calculated in accordance with JIS-Z-8729 are such that absolute values of the a* value and the b* value when the single transmittance is measured are no more than 1, absolute values of the a* value and the b* value measured with two of the base materials being arranged in parallel with respect to an absorption axis direction are no more than 2, and absolute values of the a* value and the b* value measured with two of the base materials being arranged orthogonally with respect to an absorption axis direction are no more than 2;
- and
- the single transmittance is 35-60%,
- wherein the base material contains a plurality of azo compounds, and wherein the plurality of azo compounds comprises an azo compound represented by formula (1) or a salt thereof, and an azo compound represented by formula (2) or a salt thereof;
- or an azo compound represented by formula (1) or a salt thereof, and an azo compound represented by formula (3) or a salt thereof:
- (wherein A1 represents a phenyl group or naphthyl group having a substituent group;
- R1 and R2 each independently represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group, or a lower alkoxy group having a sulfo group;
- and X1 represents a phenylamino group optionally having a substituent group);
- (wherein each of R3 to R6 independently represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group, a lower alkoxy group having a sulfo group, a carbonyl group, or a halogen atom);
- (wherein each of A2 and A3 independently represents a naphthyl group or phenyl group of which at least one substituent group is a sulfo group, lower alkyl group, lower alkoxy group, lower alkoxy group having a sulfo group, carboxy group, nitro group, amino group, or substituted amino group;
- and each of R7 and R8 independently represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group, or a lower alkoxy group having a sulfo group).
Dependencies are inferred from the claim text.