US 11,789,307 B2
Colorant filter, backlight unit, and liquid crystal display device
Nobutaka Fukagawa, Kanagawa (JP); Yu Naito, Kanagawa (JP); and Daisuke Sasaki, Kanagawa (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on Oct. 6, 2020, as Appl. No. 17/64,094.
Application 17/064,094 is a continuation of application No. PCT/JP2019/015272, filed on Apr. 8, 2019.
Claims priority of application No. 2018-076358 (JP), filed on Apr. 11, 2018.
Prior Publication US 2021/0026199 A1, Jan. 28, 2021
Int. Cl. G02B 5/22 (2006.01); G02F 1/13357 (2006.01); G02F 1/1335 (2006.01); C09B 57/00 (2006.01)
CPC G02F 1/133603 (2013.01) [C09B 57/007 (2013.01); G02B 5/22 (2013.01); G02B 5/223 (2013.01); G02F 1/133514 (2013.01); G02F 1/133528 (2013.01); C09K 2323/00 (2020.08); C09K 2323/03 (2020.08); C09K 2323/031 (2020.08); G02F 2201/50 (2013.01); G02F 2202/28 (2013.01); G02F 2203/055 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A colorant filter comprising:
at least one colorant; and
at least one binder resin,
wherein the colorant filter has an absorption spectrum having an absorption maximum in a wavelength region of 585 nm to 620 nm, and
in the absorption spectrum, a difference D1 between two wavelengths which give 10% absorbance with respect to an absorbance at the absorption maximum and a difference D2 between two wavelengths which give 50% absorbance with respect to the absorbance at the absorption maximum satisfy Expressions (a) and (b),
D1≤90 nm  (a)
D1/D2≤4.0, and  (b)
wherein a colorant included in the colorant filter is represented by Formula (2):

OG Complex Work Unit Chemistry
wherein, in Formula (2), A1 is a heterocyclic group selected from a furan ring, a thiophene ring, an imidazole ring, a pyrazole ring, a thiazole ring, an oxazole ring, a triazole ring, an indole ring, an indolenine ring, an indoline ring, a pyridine ring, a pyrimidine ring, a quinoline ring, a benzothiazole ring, a benzoxazole ring, or a pyrazolotriazole ring, R1 and R2 each independently represent a hydrogen atom or a substituent; and B1, B2, B3, and B4 each independently represent a carbon atom or a nitrogen atom,
wherein the colorant represented by Formula (2) is a colorant represented by any one of Formulae (3) to (5):

OG Complex Work Unit Chemistry
wherein in Formula (3) R1 and R2 each independently represent a hydrogen atom or a substituent; and B1, B2, B3, and B4 each independently represent a carbon atom or a nitrogen atom, and R3 and R4 each independently represent a hydrogen atom or a substituent,
wherein in Formula (4) R1 and R2 each independently represent a hydrogen atom or a substituent; and B1, B2, B3, and B4 each independently represent a carbon atom, and R5 and R6 each independently represent a hydrogen atom or a substituent, and
wherein in Formula (5) R1 and R2 each independently represent a hydrogen atom or a substituent; and B1, B2, B3, and B4 each independently represent a carbon atom, and R7 and R8 each independently represent a hydrogen atom or a substituent.