Near-infrared-absorbing dye, optical filter, and imaging device
Provided is a near-infrared-absorbing dye increasing a visible light transmittance and having a near-infrared blocking characteristic. The near-infrared-absorbing dye has an absorption characteristic measured by dissolving the dye in dichloromethane satisfying the following requirements. ⋅In an absorption spectrum at a wavelength of 400 to 800 nm, there is a maximum absorption wavelength λ max in a wavelength region of 670 nm or more. ⋅The following relational expression is established between a maximum absorption constant ε A with respect to light with a wavelength of 430 to 550 nm and a maximum absorption constant ε B with respect to light with a wavelength of 670 nm or more, where ε B /ε A ≥65. ⋅In a spectral transmittance curve, an average transmittance of light with a wavelength of 430 to 460 nm is 94.0% or more when a transmittance at the maximum absorption wavelength λ max is set to 1%.
1. A near-infrared-absorbing dye, having an absorption characteristic measured by dissolving the dye in dichloromethane satisfying requirements (i-1) to (i-3):
(i-1) in an absorption spectrum at a wavelength of 400 to 800 nm, there is a maximum absorption wavelength λ max in a wavelength region of 670 nm or more;
(i-2) the following relational expression is established between a maximum absorption constant ε A with respect to light with a wavelength of 430 to 550 urn and a maximum absorption constant 6B with respect to light with a wavelength of 670 nm or more,
ε B /ε A ≥65; and
(i-3) in a spectral transmittance curve, an average transmittance of light with a wavelength of 430 to 460 nm is 94.0% or more when a transmittance at the maximum absorption wavelength λ max is set to 1%.
2. The near-infrared-absorbing dye according to claim 1 , wherein the absorption characteristic measured by dissolving the dye in dichloromethane satisfies a requirement (i-4):
(i-4) in a spectral transmittance curve, when wavelengths with which transmittances become 80%, 10% on a shorter wavelength side than the maximum absorption wavelength λ max are respectively set to a wavelength λ 80 and a wavelength λ 10 when the transmittance at the maximum absorption wavelength λ max is set to 1%, a maximum value of a slope of the spectral transmittance curve between the wavelength λ 80 and the wavelength λ 10 is −0.5 [%/nm] or less.
3. The near-infrared-absorbing dye according to claim 1 , wherein the absorption characteristic measured by dissolving the dye in dichloromethane satisfies a requirement (i-5):
(i-5) in a spectral transmittance curve, a transmittance of light with a wavelength of 410 to 460 nm is 93.0% or more when the transmittance at the maximum absorption wavelength λ max is set to 1%.
4. The near-infrared-absorbing dye according to claim 1 , wherein the absorption characteristic measured by dissolving the dye in dichloromethane satisfies a requirement (i-6):
(i-6) in a spectral transmittance curve, a longest wavelength where a transmittance with respect to light with a wavelength of 460 nm or less becomes 97% is 457 nm or less when the transmittance at the maximum absorption wavelength λ max is set to 1%.
5. The near-infrared-absorbing dye according to claim 1 , wherein the absorption characteristic measured by dissolving the dye in dichloromethane satisfies a requirement (i-7):
(i-7) in a spectral transmittance curve, a difference between the wavelength λ 80 with which the transmittance becomes 80% on a shorter wavelength side than e maximum absorption wavelength λ max and the maximum absorption wavelength λ max is 78 nm or less when the transmittance at the maximum absorption wavelength λ max is set to 1%.
6. The near-infrared-absorbing dye according to claim 1 , wherein in (i-3), the average transmittance of light with the wavelength of 430 to 460 nm is 95.0% or more.
7. The near-infrared-absorbing dye according to claim 1 , which is formed of a squarylium-based compound and wherein the squarylium-based compound is a squarylium-based compound represented by Formula (AI):
in Formula (AI),
each of rings Z is independently a five-membered ring or a six-membered ring which may contain 0 to 3 pieces of heteroatoms in the ring and which may have a substituent,
R 1 and R 2 , R 2 and R 3 , and R 1 and a carbon atom or the heteroatom forming the ring Z may couple with each other and respectively form a hetero ring A; a hetero ring B, and a hetero ring C together with a nitrogen atom, when the hetero ring is not formed, R 1 and R 2 each independently represent a hydrogen atom, or a hydrocarbon group which may contain an unsaturated bond, a heteroatom, a saturated or unsaturated ring structure between carbon atoms and which may have a substituent, R 3 each independently represent an alkyl group or an alkoxy group which may contain a hydrogen atom, a halogen atom, a hydroxyl group, or a heteroatom between carbon atoms, and
R 4 each independently represent an alkyl group or an alkoxy group which may contain a hydrogen atom, a halogen atom, a hydroxyl group, or a heteroatom between carbon atoms.
8. The near-infrared-absorbing dye according to claim 7 , wherein
the ring Z contains at least one nitrogen atom or sulfur atom as a heteroatom.
9. The near-infrared-absorbing dye according to claim 7 , wherein
the ring Z is an aromatic hetero ring.
10. The near-infrared-absorbing dye according to claim 7 , wherein
the rings Z each independently are a pyrrolidine ring, a piperidine ring, a piperazine ring, a pyrrole ring, a thiophene ring, an imidazole ring, a pyrazole ring; a thiazole ring; an isothiazole ring, an oxazole ring, an isoxazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, or a triazole ring.
11. The near-infrared-absorbing dye according to claim 7 , wherein
in Formula (AI), R 1 and R 2 each independently are a hydrogen atom, or a hydrocarbon group with a carbon number of 1 to 20 which may contain an unsaturated bond, a heteroatom, a saturated or unsaturated ring structure between carbon atoms, and which may have a substituent,
R 3 and R 4 each independently are an alkyl group or an alkoxy group with a carbon number of 1 to 20 which may contain a hydrogen atom, a halogen atom, or a heteroatom between carbon atoms.
12. The near-infrared-absorbing dye according to claim 7 , wherein
in Formula (AI), R 1 and R 2 each independently are an alkyl group or an alkoxy group with a carbon number of 1 to 20 which may contain with a heteroatom between carbon atoms and which may have a substituent.
13. The near-infrared-absorbing dye according to claim 1 , which is formed of a squarylium-based compound and, wherein the squarylium-based compound is a squarylium-based compound represented by Formula (AII):
in Formula (AII),
R 6 each independently represent a hydrogen atom, or a hydrocarbon group which may contain an unsaturated bond, a heteroatom, a saturated or unsaturated ring structure between carbon atoms and which may have a substituent,
R 7 each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, or an alkyl group or an alkoxy group which may contain a heteroatom between carbon atoms,
R 8 each independently represent a halogen atom, a hydroxyl group, an alkoxy group with a carbon number of 1 to 12, an acyl group or an acyloxy group with a carbon number of 1 to 12, a perfluoroalkyl group with a carbon number of 1 to 12, or a —SO 2 R 9 group (where R 9 represents an alkyl group with a carbon number of 1 to 12 which may have a substituent), and
X 2 each represent a bivalent hydrocarbon group which may contain an unsaturated bond, a heteroatom, a saturated or unsaturated ring structure between carbon atoms and which may have a substituent.
14. An optical filter, comprising:
an absorption layer which contains: the near-infrared-absorbing dye according to claim 1 ; and a resin.
15. The optical filter according to claim 14 , wherein
an average transmittance of light with a wavelength of 430 to 550 nm is 90% or more, and a minimum transmittance of light with the wavelength of 430 to 550 nm is 75% or more in a spectral transmittance curve at an incident angle of 0°.
16. The optical filter according to claim 15 , wherein
an average transmittance of light with a wavelength of 430 to 480 nm is 87% or more in a spectral transmittance curve at an incident angle of 0°.
17. The optical filter according to claim 16 , wherein requirements (iii-3) to (iii-6) are satisfied:
(iii-3) an average transmittance of light with a wavelength of 600 to 700 nm is 25% or more in a spectral transmittance curve at an incident angle of 0°;
(iii-4) an average transmittance of light with a wavelength of 350 to 395 nm is 2% or less in a spectral transmittance curve at an incident angle of 0°;
(iii-5) an average transmittance of light with a wavelength of 710 to 1100 nm is 2% or less in a spectral transmittance curve at an incident angle of 0°; and
(iii-6) an average value of an absolute value of a difference between a transmittance of light with a wavelength of 600 to 700 nm in a spectral transmittance curve at an incident angle of 0° and a transmittance of light with the wavelength of 600 nm to 700 nm in a spectral transmittance curve at an incident angle of 30° is 7%/nm or less.
18. The optical filter according to claim 14 , wherein
the absorption layer is provided on a transparent substrate.
19. The optical filter according to claim 18 , wherein
the transparent substrate is a glass substrate.
20. The optical filter according to claim 19 , wherein
the transparent substrate is a near-infrared-absorbing glass substrate.
21. The optical filter according to claim 18 , wherein
the transparent substrate is formed of a resin.
22. The optical filter according to claim 14 , wherein
the absorption layer functions as a resin substrate.
23. An imaging device, comprising:
a solid-state image sensor;
an imaging lens; and
the optical filter according to claim 14 .
24. A near-infrared-absorbing dye being formed of a squarylium-based compound represented by Formula (AI):
in Formula (AI),
each of rings Z is independently a five-membered ring or a six-membered ring which may contain 0 to 3 pieces of heteroatoms in the ring and which may have a substituent,
R 1 and R 2 , R 2 and R 3 , and R 1 and a carbon atom or the heteroatom forming the ring Z may couple with each other and respectively form a hetero ring A, a hetero ring B, and a hetero ring C together with a nitrogen atom, and when the hetero ring is not formed, R 1 and R 2 each independently represent a hydrogen atom, or a hydrocarbon group which may contain an unsaturated bond, a heteroatom, a saturated or unsaturated ring structure between carbon atoms and which may have a substituent, R 3 each independently represent an alkyl group or an alkoxy group which may contain a hydrogen atom, a halogen atom, a hydroxyl group, or a heteroatom between carbon atoms, and
R 4 each independently represent an alkyl group or an alkoxy group which may contain a hydrogen atom, a halogen atom, a hydroxyl group, or a heteroatom between carbon atoms.
25. The near-infrared-absorbing dye according to claim 24 , wherein
the ring Z contains at least one nitrogen atom or sulfur atom as a heteroatom.
26. The ear-infrared-absorbing dye according to claim 24 , wherein
the ring Z is an aromatic hetero ring.
27. The near-infrared-absorbing dye according to claim 24 , wherein
the rings Z each independently are a pyrrolidine ring, a piperidine ring, a piperazine ring, a pyrrole ring, a thiophene ring, an imidazole ring, a pyrazole ring, a thiazole ring, an isothiazole ring, an oxazole ring, an isoxazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, or a triazole ring.
28. A near-infrared-absorbing dye being formed of a squarylium-based compound represented by Formula (AII):
in Formula (AII),
R 6 each independently represent a hydrogen atom, or a hydrocarbon group which may contain an unsaturated bond, a heteroatom, a saturated or unsaturated ring structure between carbon atoms and which may have a substituent,
R 7 each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, or an alkyl group or an alkoxy group which may contain a heteroatom between carbon atoms,
R 8 each independently represent a halogen atom, a hydroxyl group, an alkoxy group with a carbon number of 1 to 12, an acyl group or an acyloxy group with a carbon number of 1 to 12, a perfluoroalkyl group with a carbon number of 1 to 12, or a —SO 2 R 9 group (where R 9 represents an alkyl group with a carbon number of 1 to 12 which may have a substituent), and
X 2 each represent a bivalent hydrocarbon group which may contain an unsaturated bond, a heteroatom, a saturated or unsaturated ring structure between carbon atoms and which may have a substituent.