JP6693585B2 - Optical filter and device using optical filter - Google Patents

Description

  The present invention relates to an optical filter and a device using the optical filter. Specifically, the present invention relates to an optical filter (two-wavelength bandpass filter) that selectively transmits visible light and a part of near-infrared light, and a solid-state imaging device and a camera module using the optical filter.

  CCDs and CMOS image sensors that are solid-state image pickup devices for color images are used in solid-state image pickup devices such as video cameras, digital still cameras, mobile phones with camera functions, and smartphones. In, a silicon photodiode is used which has a sensitivity to near infrared rays which cannot be perceived by human eyes. In these solid-state image pickup devices, it is necessary to perform luminosity correction to obtain a natural color to the human eye, and an optical filter (for example, near infrared cutoff) that selectively transmits or cuts light rays in a specific wavelength range. Filter) is often used.

  As such a near infrared cut filter, those manufactured by various methods have been conventionally used. For example, Patent Document 1 describes a near-infrared cut filter in which a substrate made of a transparent resin is used and a near-infrared absorber is contained in the transparent resin, and Patent Document 2 describes a glass substrate containing a copper ion. A near infrared cut filter using is described.

  On the other hand, in recent years, attempts have been made to provide a camera module with a sensing function such as motion capture using near infrared rays and distance recognition (space recognition). In such an application, it is necessary to selectively transmit visible light and a part of near infrared rays, and thus a near infrared cut filter that uniformly shields near infrared rays cannot be used.

  As an optical filter that selectively transmits visible light and some near infrared rays, Toa Rikagaku Kenkyusho Co., Ltd. and Ceratech Japan Co., Ltd. sell filters that have a dielectric multilayer film formed on a glass substrate. There is.

JP-A-6-200113 Japanese Patent No. 5036229

  The optical filter commercially available as an optical filter that selectively transmits the visible light and a part of the near-infrared has a problem that the spectral characteristics are significantly changed when the light is obliquely incident on the filter. In particular, if the incident angle dependence of the optical filter is large on the long-wavelength side of the visible light transmission band or on the short-wavelength side of the near-infrared selective transmission band, when the light ray enters from the diagonal of the filter, the near-infrared light used for the sensing function In addition to the deterioration of the signal noise ratio (S / N ratio), there are problems that the image quality of the camera and the color reproducibility at the edge of the image are adversely affected. FIG. 1 shows an example of a spectral transmission spectrum of a conventional two-wavelength bandpass filter. However, when the incident angle becomes 30 °, the near-infrared selective transmission band shifts significantly to the short wavelength side, which is essentially cut. It is confirmed that the transmittance in the proper wavelength region (in the example of this figure, around 750 to 800 nm) becomes high. For this reason, there is little dependency on the incident angle on the short wavelength side of the near infrared selective transmission band, and a good near infrared ray S / N ratio, camera image quality, selective transmission of visible light and some near infrared rays. An optical filter that satisfies all of the requirements has been desired.

  An object of the present invention is to provide an optical filter having a function of selectively transmitting visible light and a part of near-infrared rays and having little incident angle dependency, and an apparatus using the optical filter. ..

The present inventors have conducted extensive studies to achieve the above-mentioned object, and by using an optical filter having specific optical characteristics, the above-mentioned object can be solved, particularly on the short wavelength side of the near-infrared selective transmission band. The inventors have found that the incident angle dependence can be reduced, and have completed the present invention.
The example of the aspect of this invention is shown below.

[1] An optical filter which selectively transmits visible light and a part of near infrared rays,
It has a light ray stop band Za, a light ray transmission band Zb, and a light ray stop band Zc in the wavelength region of 650 nm or more, and the center wavelength of each band is Za <Zb <Zc,
The transmittance at a wavelength of 800 nm is 20% or less when measured from the vertical direction of the optical filter, and the transmittance is 50% or less when measured from the direction of 30 ° with respect to the vertical direction of the optical filter. filter.

  [2] In the wavelength range of 700 to 800 nm, the average value of the transmittance when measured from the vertical direction of the optical filter is 5% or less, and when measured from the direction of 30 ° with respect to the vertical direction of the optical filter. The optical filter according to [1], which has an average transmittance of 10% or less.

[3] Of Zb, a wavelength value on the shortest wavelength side (Xa) and a wavelength value on the longest wavelength side (Xb), which have a transmittance of 50% when measured in the direction perpendicular to the optical filter. Xb−Xa is 5 to 150 nm, and the Y value represented by Y = (Xa + Xb) / 2 is 820 to 950 nm. [1] or [2].
[4] Among Zb, the wavelength value (Xa) on the shortest wavelength side, which has a transmittance of 50% when measured from the direction perpendicular to the optical filter, is 810 to 900 nm, and [1] to [3 ] The optical filter according to any one of.

  [5] The minimum transmittance when measured from the vertical direction of the optical filter in Za and Zc is 4% or less, and the maximum transmittance when measured from the vertical direction of the optical filter in Zb is 55% or more. The optical filter according to any one of [1] to [4].

  [6] The optical filter according to any one of [1] to [5], which has an average transmittance of 60% or more measured in the vertical direction of the optical filter in the wavelength range of Y-10 nm to Y + 10 nm.

[7] The optical filter has a base material (i), and the base material (i) has a transparent resin layer containing a compound (S) having an absorption maximum at a wavelength of 750 to 850 nm. The optical filter according to any one of 6].
[8] The optical filter according to [7], wherein the compound (S) is a compound represented by the following formula (S1).

(S1)
[In the formula (S1), X independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom or —NR ⁸ —,
R ^{1 to} R ⁸ are each independently a hydrogen atom, halogen atom, sulfo group, hydroxyl group, cyano group, nitro group, carboxy group, phosphoric acid group, —NR ^g R ^h group, —SO ₂ R ⁱ group, —OSO. It represents either ₂ R ⁱ group or a group represented by L ^a ~L ^h, are each R ^g and R ^h independently represent any of hydrogen atom, -C (O) R ⁱ groups or the following L ^a ~L ^e , R ⁱ represents any of the following L ^a ~L ^e,
(L ^a ) C 1-12 aliphatic hydrocarbon group (L ^b ) ^C 1-12 halogen-substituted alkyl group (L ^c ) ^C 3-14 alicyclic hydrocarbon group (L ^d ) carbon Number of carbon atoms which may have an aromatic hydrocarbon group (L ^e ) having 6 to 14 carbon atoms, a heterocyclic group having 3 to 14 carbon atoms (L ^f ) and an alkoxy group having 1 to 12 carbon atoms (L ^g ) substituent L 1-12 acyl groups,
(L ^h ) an alkoxycarbonyl group having 1 to 12 carbon atoms which may have a substituent L, the substituent L is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a halogen-substituted alkyl group having 1 to 12 carbon atoms, It is at least one selected from the group consisting of an alicyclic hydrocarbon group having 3 to 14 carbon atoms, an aromatic hydrocarbon group having 6 to 14 carbon atoms, and a heterocyclic group having 3 to 14 carbon atoms. ]

  [9] The optical filter according to [7] or [8], wherein the transparent resin layer contains a compound (A) having an absorption maximum at a wavelength of 600 nm or more and less than 750 nm, in addition to the compound (S).

  [10] The transparent resin layer has a cyclic (poly) olefin resin, aromatic polyether resin, polyimide resin, fluorene polycarbonate resin, fluorene polyester resin, polycarbonate resin, polyamide resin, polyarylate resin. , Polysulfone resin, polyether sulfone resin, polyparaphenylene resin, polyamideimide resin, polyethylene naphthalate resin, fluorinated aromatic polymer resin, (modified) acrylic resin, epoxy resin, allyl ester [7] to [9] containing at least one resin selected from the group consisting of a system curable resin, a silsesquioxane UV curable resin, an acrylic UV curable resin and a vinyl UV curable resin. The optical filter according to any one.

  [11] The optical filter according to any one of [7] to [10], which has a dielectric multilayer film on at least one surface of the base material (i).

[12] The optical filter according to any one of [1] to [11], which is for a solid-state imaging device.
[13] A solid-state imaging device including the optical filter according to any one of [1] to [12].
[14] A camera module including the optical filter according to any one of [1] to [12].

  According to the present invention, it is possible to provide an optical filter that is excellent in the transmission characteristics of visible light and a part of near-infrared rays and that has little dependence on the incident angle.

FIG. 1 shows an example of a spectral transmission spectrum of a conventional two-wavelength bandpass filter. FIG. 2A is a schematic diagram showing a method of measuring the transmittance when measured from the vertical direction of the optical filter. FIG. 2B is a schematic diagram showing a method for measuring the transmittance when measured from an angle of 30 ° with respect to the vertical direction of the optical filter. FIG. 3 is a spectral transmission spectrum of the substrate obtained in Example 1. FIG. 4 is a spectral transmission spectrum of the optical filter obtained in Example 1. FIG. 5 is a spectral transmission spectrum of the substrate obtained in Example 2. FIG. 6 is a spectral transmission spectrum of the optical filter obtained in Example 2. FIG. 7 is a spectral transmission spectrum of the optical filter obtained in Comparative Example 1. FIG. 8 is a spectral transmission spectrum of the optical filter obtained in Comparative Example 2.

  Hereinafter, the present invention will be specifically described.

≪Optical filter≫
The optical filter of the present invention is a filter that selectively transmits visible light and a part of near infrared rays, and has a light stop band Za, a light transmission band Zb, and a light stop band Zc in a region of a wavelength of 650 nm or more, The center wavelength of each band is Za <Zb <Zc, the transmittance at a wavelength of 800 nm when measured from the vertical direction of the optical filter is 20% or less, and the direction of 30 ° with respect to the vertical direction of the optical filter. The optical filter has a transmittance of 50% or less when measured from. Such an optical filter of the present invention has excellent transmittance characteristics of visible light and a part (desired region) of near-infrared rays, and further has little dependence on the incident angle, particularly on the short wavelength side of the near-infrared selective transmission band. It is an optical filter with little dependence on the incident angle.

  The optical filter of the present invention has a transmittance of 20% or less at a wavelength of 800 nm when measured from the vertical direction of the optical filter, and when the filter is used for a solid-state imaging device having a near-infrared sensing function as well. Is more preferably 15% or less, further preferably 10% or less, particularly preferably 5% or less. The transmittance at a wavelength of 800 nm when measured from the direction of 30 ° with respect to the vertical direction of the optical filter is 50% or less, preferably 40% or less, more preferably 30% or less, particularly preferably 20%. % Or less. Since the optical filter of the present invention has the above-mentioned optical characteristics, it has excellent transmittance characteristics of visible light and a part (desired region) of near-infrared rays, and has little incidence angle dependence, particularly a short near-infrared selective transmission band. It is possible to obtain an optical filter that is less dependent on the incident angle on the wavelength side, and it is possible to effectively cut rays of unnecessary wavelengths and improve the color reproducibility of the obtained camera image.

The optical filter of the present invention preferably has a low transmittance in the wavelength range of 700 to 800 nm. By lowering the transmittance in this wavelength range, the filter is used for a device having a sensor, for example, a solid-state imaging device. In that case, it is considered that the detected noise is reduced in the sensor. Therefore, it is considered preferable that the transmittance at the wavelength of 800 nm is low, but the conventional optical filter cannot achieve the low transmittance at the wavelength of 800 nm. In particular, when the incident angle of light incident on a conventional optical filter changes (for example, 30 ° with respect to the vertical direction of the filter surface), the transmittance at a wavelength of 800 nm usually increases, and such a filter has various characteristics. It could not be used in applications where light may be incident from an angle and where noise reduction is required.
On the other hand, according to the optical filter of the present invention, the transmittance at a wavelength of 700 to 800 nm can be suppressed to a low level, and even if the angle of incidence on the filter changes, the transmittance at a wavelength of 800 nm is low, so that various angles can be obtained. It can be particularly suitably used for applications in which light may be incident from, and applications in which noise reduction is required.

  The optical filter of the present invention has a light ray stop band Za, a light ray transmission band Zb, and a light ray stop band Zc in a wavelength region of 650 nm or more. However, the central wavelength of each band is Za <Zb <Zc.

  Za has a wavelength of 650 nm or more and 900 nm or less, and the transmittance when measured from the vertical direction of the optical filter is from the shortest wavelength Za1 of more than 20% to 20% or less to the longest wavelength of less than 20% to 20% or more. It refers to the wavelength band up to Za2. The center wavelength of Za is (Za1 + Za2) / 2 nm.

  Zb is a wavelength of 750 nm or more and 1050 nm or less, in which the transmittance when measured in the vertical direction of the optical filter is 40% or less to 40% or more, the shortest wavelength Zb1 to 40% to 40% or less, the longest wavelength. It refers to the wavelength band up to Zb2. The center wavelength of Zb is (Zb1 + Zb2) / 2 nm.

  Zc indicates a wavelength band from the shortest wavelength Zc1 at which the transmittance measured from the vertical direction of the optical filter is 20% to 20% to the wavelength Zc2 which is Zc1 + 200 nm at a wavelength of 820 nm or more. The center wavelength of Zc is (Zc1 + Zc2) / 2 nm.

  When the optical filter of the present invention is used in a solid-state imaging device having a near-infrared sensing function as well, it is preferable that the maximum transmittance of the light ray (near-infrared) transmission band Zb is high, and the minimum transmission of the light ray stop bands Za and Zc. A lower rate is preferable. In such a case, the solid-state imaging device or the like having the optical filter of the present invention can achieve excellent near-infrared sensing performance and can effectively cut light rays of unnecessary wavelengths, so that color reproduction is possible. It is possible to obtain a camera image having excellent properties.

  The maximum transmittance when measured from the vertical direction of the optical filter in the light transmission band Zb is preferably 55% or more, more preferably 57% or more, further preferably 60% or more, and particularly preferably 63% or more. The minimum transmittance measured in the vertical direction of the optical filter in the light stop bands Za and Zc is preferably 4% or less, more preferably 3% or less, further preferably 2% or less, and particularly preferably 1% or less. .. When the maximum transmittance in Zb or the minimum transmittance in Za and Zc is within the above range, the solid-state imaging device or the like having the optical filter of the invention achieves high near-infrared sensing performance and less noise, resulting in color reproduction. It is possible to obtain an excellent camera image.

  Of the Zb, the difference Xb between the value of the wavelength on the shortest wavelength side (Xa) and the value of the wavelength on the longest wavelength side (Xb), which has a transmittance of 50% when measured from the vertical direction of the optical filter. The width of the light transmission band Zb can be defined by -Xa, and the value of Xb-Xa is preferably 5 to 150 nm, more preferably 10 to 140 nm, and particularly preferably 15 to 130 nm. The value of Y represented by Y = (Xa + Xb) / 2 is preferably 820 to 950 nm, more preferably 825 to 920 nm, further preferably 830 to 890 nm, and particularly preferably 835 to 880 nm. When the values of Xb-Xa and Y are in this range, it is possible to obtain an optical filter that is more excellent in near infrared sensing sensitivity and color reproducibility of camera images.

  The Xa is preferably in the range of 810 to 900 nm, more preferably 810 to 860 nm, and particularly preferably 810 to 840 nm. When Xa is in this range, a desired light ray can be transmitted and blocked in the near infrared region, and noise can be reduced, which is preferable.

  The optical filter of the present invention has a transmittance curve measured from an angle of 30 ° with respect to the vertical direction of the optical filter, and has a transmittance of 50% in a band corresponding to Zb, which is the shortest wavelength side wavelength. The absolute value | Xa−Xa ′ | of the difference between the value (Xa ′) and the Xa is preferably 30 nm or less, more preferably 25 nm or less, further preferably 20 nm or less, and particularly preferably 15 nm or less. When the value of | Xa−Xa ′ | is in this range, an optical filter having a small incident angle dependence of the spectral characteristic can be obtained, and when the optical filter is used for a camera module having a sensing function, light is not emitted. A good near-infrared S / N ratio and camera image quality can be achieved at the same time even when the light is obliquely incident on the filter.

The optical filter of the present invention, with respect to the Y, has an average transmittance of preferably 60% or more, more preferably 65% or more, further preferably when measured from the vertical direction of the optical filter in the wavelength range of Y-10 nm to Y + 10 nm. Is 70% or more, particularly preferably 80% or more.
A filter having such a transmission characteristic can achieve a high light transmission characteristic in a visible region and a target near-infrared region, and can achieve both a camera function and a near-infrared sensing function at a good level.

  When the optical filter of the present invention is used for a solid-state imaging device having a near-infrared sensing function as well, the average value of the transmittance when measured from the vertical direction of the optical filter in the wavelength range of 700 to 800 nm is preferably 5% or less, more preferably 4% or less, further preferably 3% or less, further preferably 2% or less, particularly preferably 1% or less, when measured from a direction of 30 ° to the vertical direction of the optical filter. The average value of the transmittance is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, further preferably 5% or less, and particularly preferably 3% or less. When the optical filter of the present invention has such optical characteristics, it can effectively cut light rays having unnecessary wavelengths, and can improve color reproducibility of a camera image. The optical filter has these effects even when it is incident from an oblique direction.

  When the optical filter of the present invention is used in a solid-state image sensor or the like, it is preferable that the visible light transmittance is high. Specifically, in the wavelength region of 430 to 580 nm, the average transmittance when measured from the vertical direction of the optical filter is preferably 75% or more, more preferably 80% or more, further preferably 83% or more, particularly preferably Is 85% or more. When the average transmittance is within this range in this wavelength range, excellent imaging sensitivity can be achieved when the optical filter of the present invention is used as a solid-state imaging device.

  The optical filter of the present invention has the shortest wavelength value (Xd) at which the transmittance is 50% when measured from the vertical direction of the optical filter in the wavelength range of 560 to 800 nm and the vertical direction of the optical filter. It is preferable that the absolute value of the difference from the value (Xe) of the shortest wavelength at which the transmittance is 50% when measured from an angle of 30 ° is small, specifically, preferably less than 25 nm, more preferably 15 nm. Less, particularly preferably less than 10 nm. According to the optical filter having such an optical characteristic, it is possible to obtain an optical filter having a small viewing angle dependence of the spectral characteristic and a wide viewing angle, and particularly when used for a camera module or the like, a good camera image quality or Color reproducibility at the edge of the image can be achieved.

The thickness of the optical filter of the present invention may be appropriately selected according to the desired application, but according to the recent trend of thinning and weight saving of the solid-state imaging device, the thickness of the optical filter of the present invention is also thin. Is preferred.
The thickness of the optical filter of the present invention is, for example, 260 μm or less, preferably 210 μm or less, more preferably 160 μm or less, further preferably 120 μm or less, particularly preferably 90 μm or less, and the lower limit is not particularly limited, but is, for example, 20 μm. Is desirable.

<Structure of optical filter, etc.>
The structure of the optical filter of the present invention is not particularly limited, but it has a transparent resin layer containing the following compound (S) from the viewpoints that it can be made thin and an optical filter having the above-mentioned optical characteristics can be easily obtained. It is preferable to contain the substrate (i), and it is preferable to have the substrate (i) and the dielectric multilayer film. Further, the optical filter of the present invention may include other functional films depending on the desired application, required characteristics and the like.

[Substrate (i)]
The base material (i) may be a single layer or a multilayer, as long as it has at least a transparent resin layer containing one or more of the following compound (S). When the base material (i) is a single layer, for example, a base material made of a transparent resin substrate (ii) containing the compound (S) can be mentioned, and the transparent resin substrate (ii) is the transparent resin layer. Becomes In the case of a multilayer, for example, a support such as a glass support or a resin support serving as a base, or an overcoat layer made of a curable resin containing the compound (S) on a transparent resin substrate (ii), etc. Examples thereof include a base material on which a transparent resin layer is laminated, and a base material on which a resin layer such as an overcoat layer made of a curable resin or the like is laminated on a transparent resin substrate (ii) containing the compound (S). .. From the standpoints of manufacturing cost, ease of adjusting optical characteristics, achievement of scratch erasing effect of the resin support and transparent resin substrate (ii), and improvement of scratch resistance of the substrate (i), the compound (S A base material in which a resin layer such as an overcoat layer made of a curable resin is laminated on a transparent resin substrate (ii) containing a) is particularly preferable.
Hereinafter, the layer containing the compound (S) and the transparent resin is also referred to as "transparent resin layer", and the other resin layers are simply referred to as "resin layer".

The lowest transmittance (Tb) measured from the vertical direction of the substrate (i) in the wavelength region of 750 nm or more is preferably 40% or less, more preferably 25% or less, and particularly preferably 10% or less.
The shortest wavelength (Xf) at which the transmittance measured from the vertical direction of the substrate (i) in the wavelength region of 750 nm or more is less than 50% to 50% or more is preferably 770 to 900 nm, more preferably 775 to 890 nm. And particularly preferably 780 to 880 nm.
If the optical properties of (Tb) and (Xf) of the base material (i) are in such a range, unnecessary near infrared rays near the near infrared selective transmission band can be selectively and efficiently cut, and for sensing. The near-infrared S / N ratio can be improved, and when the dielectric multilayer film is formed on the substrate (i), it is possible to reduce the incident angle dependence of the optical characteristics on the short wavelength side of the near-infrared selective transmission band. it can.

In the wavelength region of 600 nm or more and less than 750 nm, the lowest transmittance (Ta) measured from the vertical direction of the substrate (i) is preferably 45% or less, more preferably 25% or less, particularly preferably 10% or less. is there.
The shortest wavelength (Xc) at which the transmittance measured from the vertical direction of the substrate (i) in the wavelength region of 600 nm or more is from more than 50% to 50% or less is preferably 610 to 705 nm, more preferably 620 to 680 nm. , Particularly preferably 630 to 660 nm.
When the optical properties of (Ta) and (Xc) of the base material (i) are in such a range, unnecessary near infrared rays can be selectively and efficiently cut off, and at the same time, a dielectric layer is formed on the base material (i). When the body multilayer film is formed, it is possible to reduce the incident angle dependence of the optical characteristics in the visible region to the near infrared region.

  The average transmittance of the substrate (i) at a wavelength of 430 to 580 nm is preferably 75% or more, more preferably 78% or more, particularly preferably 80% or more. By using a substrate having such transmission characteristics, it is possible to achieve high light transmission characteristics in the visible range and the target near-infrared range, and it is possible to achieve both a camera function and a near-infrared sensing function at a good level. ..

The thickness of the base material (i) can be appropriately selected according to the desired application and is not particularly limited, but it is desirable to select it appropriately so as to reduce the incident angle dependency of the obtained optical filter, and it is preferable. Is 10 to 210 μm, more preferably 20 to 150 μm, further preferably 20 to 110 μm, and particularly preferably 30 to 80 μm.
When the thickness of the base material (i) is within the above range, the optical filter using the base material (i) can be made thin and lightweight, and can be suitably used for various applications such as a solid-state imaging device. it can. In particular, when the base material (i) made of the transparent resin substrate (ii) is used for a lens unit such as a camera module, it is preferable because the height and weight of the lens unit can be reduced.

<Compound (S)>
The compound (S) is a compound having an absorption maximum at a wavelength of 750 to 850 nm, and is preferably a squarylium compound represented by the following formula (S1). By using such a compound (S), the obtained substrate (i) can achieve sharp absorption near the absorption maximum and high visible light transmittance at the same time. Further, when a general organic dye is used for an optical filter, fluorescence is usually generated in many cases, but as a result of diligent studies by the applicant, the compound (S) has been used, whereby the fluorescence intensity that can be generated is significantly lowered. It was found that it can be suppressed. Therefore, when the optical filter of the present invention having the substrate (i) containing the compound (S) is used in a camera module having a near-infrared sensing function, malfunction of the sensing function due to dye fluorescence can be prevented. ..

In formula (S1), X independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom or —NR ⁸ —,
R ^{1 to} R ⁸ are each independently a hydrogen atom, halogen atom, sulfo group, hydroxyl group, cyano group, nitro group, carboxy group, phosphoric acid group, —NR ^g R ^h group, —SO ₂ R ⁱ group, —OSO. It represents either ₂ R ⁱ group or a group represented by L ^a ~L ^h, are each R ^g and R ^h independently represent any of hydrogen atom, -C (O) R ⁱ groups or the following L ^a ~L ^e , R ⁱ represents any of the following L ^a ~L ^e.
(L ^a ) C 1-12 aliphatic hydrocarbon group (L ^b ) ^C 1-12 halogen-substituted alkyl group (L ^c ) ^C 3-14 alicyclic hydrocarbon group (L ^d ) carbon Number of carbon atoms which may have an aromatic hydrocarbon group (L ^e ) having 6 to 14 carbon atoms, a heterocyclic group having 3 to 14 carbon atoms (L ^f ) and an alkoxy group having 1 to 12 carbon atoms (L ^g ) substituent L 1-12 acyl groups,
(L ^h ) an alkoxycarbonyl group having 1 to 12 carbon atoms which may have a substituent L, the substituent L is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a halogen-substituted alkyl group having 1 to 12 carbon atoms, It is at least one selected from the group consisting of an alicyclic hydrocarbon group having 3 to 14 carbon atoms, an aromatic hydrocarbon group having 6 to 14 carbon atoms, and a heterocyclic group having 3 to 14 carbon atoms.

R ¹ is preferably hydrogen atom, chlorine atom, fluorine atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, cyclohexyl group, phenyl. A group, a hydroxyl group, an amino group, a dimethylamino group and a nitro group, and more preferably a hydrogen atom, a chlorine atom, a fluorine atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group and a hydroxyl group.

R ^{2 to} R ⁷ are preferably each independently a hydrogen atom, chlorine atom, fluorine atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group. Group, cyclohexyl group, phenyl group, hydroxyl group, amino group, dimethylamino group, diethylamino group, cyano group, nitro group, acetylamino group, propionylamino group, N-methylacetylamino group, trifluoromethanoylamino group, pentafluoro Ethanoylamino group, t-butanoylamino group, cyclohexanoylamino group, n-butylsulfonyl group, morpholino group, methylcarbonyl group, trifluoromethylcarbonyl group, tert-butylcarbonyl group, more preferably hydrogen atom , Chlorine atom, fluorine atom, methyl group, ethyl group, -Propyl group, isopropyl group, tert-butyl group, hydroxyl group, dimethylamino group, diethylamino group, nitro group, acetylamino group, propionylamino group, trifluoromethanoylamino group, pentafluoroethanoylamino group, t-butanoyl An amino group, a cyclohexanoylamino group, and a morpholino group.

R ⁸ is preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a cyclohexyl group or a phenyl group, and more preferably Is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group.

  The above X is preferably an oxygen atom or a sulfur atom, and particularly preferably an oxygen atom.

  The structure of the compound (S) can be represented by a description method such as the following formula (S1) and a resonance structure such as the following formula (S2). That is, the difference between the following formula (S1) and the following formula (S2) is only in the method of describing the structure, and both represent the same compound. Unless otherwise specified, in the present invention, the structure of the squarylium compound is represented by the method described in the following formula (S1).

  Furthermore, for example, the compound represented by the following formula (S1) and the compound represented by the following formula (S3) can be regarded as the same compound.

  The structure of the compound (S) is not particularly limited as long as it satisfies the requirement of the formula (S1). The left and right substituents bonded to the central four-membered ring may be the same or different, but the same is preferable because it is easy to synthesize. Specific examples of the compound (S) include compounds (s-1) to (s-30) shown in Table 1 below.

The absorption maximum wavelength of the compound (S) is preferably 755 nm or more and 845 nm or less, more preferably 760 nm or more and 840 nm or less, and particularly preferably 765 nm or more and 835 nm or less. When the absorption maximum wavelength of the compound (S) is in such a range, unnecessary near infrared rays near the near infrared selective transmission band can be selectively and efficiently cut.
In the present invention, the absorption maximum wavelength of a compound is, for example, the wavelength at which the absorption becomes maximum when the transmittance of a solution obtained by dissolving the compound in a good solvent is measured (optical path length 1 cm). To be observed.

  The compound (S) may be synthesized by a generally known method, and is disclosed in, for example, JP-A-1-228960, JP-A-2001-40234, JP-A-3094037, and JP-A-3196383. It can be synthesized with reference to the described method and the like.

The content of the compound (S) is, for example, a substrate made of a transparent resin substrate (ii) containing the compound (S) or a transparent resin substrate containing the compound (S) as the substrate (i). When a base material on which a resin layer such as an overcoat layer made of a curable resin or the like is laminated on (ii), preferably 0.01 to 2.0 parts by weight relative to 100 parts by weight of the transparent resin. , More preferably 0.02 to 1.5 parts by weight, and particularly preferably 0.03 to 1.0 part by weight, and the base material (i) is a compound on a glass support or a resin support serving as a base. When a substrate having a transparent resin layer such as an overcoat layer made of a curable resin or the like containing (S) is used, 100 parts by weight of the resin forming the transparent resin layer containing the compound (S) is used. , Preferably 0.1 to 5.0 parts by weight, more preferably Is 0.2 to 4.0 parts by weight, particularly preferably 0.3 to 3.0 parts by weight. When the content of the compound (S) is within the above range, it is possible to obtain an optical filter having both good near-infrared absorption and transmission characteristics and high visible light transmittance.
As the compound (S) used for the base material (i), one type may be used alone, or two or more types may be used.

<Compound (A)>
The base material (i) may further contain, in addition to the compound (S), a compound (A) having an absorption maximum at a wavelength of 600 nm or more and less than 750 nm.

When the compound (A) and the compound (S) are used in combination, these compounds may be contained in the same layer or different layers. When they are contained in the same layer, for example, the compound (A) and the compound (S) are both contained in the same transparent resin substrate (ii) or a compound such as a glass support on a support. A base material in which a transparent resin layer containing (A) and a compound (S) is laminated can be mentioned, and when contained in different layers, for example, on a resin substrate containing the compound (A). The base material on which the transparent resin layer containing the compound (S) is laminated, or the resin layer containing the compound (A) is laminated on the transparent resin substrate (ii) containing the compound (S). A base material can be mentioned.
The compound (A) and the compound (S) are more preferably contained in the same layer, and in such a case, the compound (A) and the compound (S) are contained more than in the case where these compounds are contained in different layers. It becomes easier to control the content ratio with S).

The compound (A) is not particularly limited as long as it has an absorption maximum at a wavelength of 600 nm or more and less than 750 nm, but is preferably a solvent-soluble dye compound, and a group consisting of a squarylium compound, a phthalocyanine compound and a cyanine compound. More preferably, it is at least one selected from the above, more preferably contains a squarylium compound, more preferably contains at least one squarylium compound and one or more other compounds (A), and other compounds (A) Of these, phthalocyanine compounds and cyanine compounds are particularly preferable.
Squarylium compounds have excellent visible light transmittance, steep absorption characteristics, and high molar extinction coefficient, but they sometimes generate fluorescence that causes scattered light when absorbing light. In such a case, by using the squarylium compound and the other compound (A) in combination, it is possible to obtain a better camera image quality with less scattered light.

  The absorption maximum wavelength of the compound (A) is preferably 620 nm or more and 748 nm or less, more preferably 650 nm or more and 745 nm or less, and particularly preferably 660 nm or more and 740 nm or less. By containing the compound (A) in addition to the compound (S) in the base material (i), it is possible to reduce the incident angle dependence of the visible region in addition to the short wavelength side of the near infrared selective transmission band. It becomes easier to reduce the absolute value of the difference between () and (Xe).

  The content of the compound (A) is, for example, a substrate made of a transparent resin substrate (ii) containing the compound (A) or a transparent resin substrate containing the compound (A) as the substrate (i). When a base material on which a resin layer such as an overcoat layer made of a curable resin or the like is laminated on (ii), preferably 0.01 to 2.0 parts by weight relative to 100 parts by weight of the transparent resin. , More preferably 0.02 to 1.5 parts by weight, and particularly preferably 0.03 to 1.0 part by weight, and the base material (i) is a compound on a glass support or a resin support serving as a base. When a substrate having a transparent resin layer such as an overcoat layer made of a curable resin or the like containing (A) is used, 100 parts by weight of the resin forming the transparent resin layer containing the compound (A) is used. , Preferably 0.1 to 5.0 parts by weight, more preferably Is 0.2 to 4.0 parts by weight, particularly preferably 0.3 to 3.0 parts by weight.

<Other dyes (X)>
The base material (i) may further contain another dye (X) that does not correspond to the compound (S) and the compound (A).
The other dye (X) is not particularly limited as long as it has an absorption maximum wavelength of less than 600 nm or more than 850 nm, and examples thereof include squarylium compounds, phthalocyanine compounds, cyanine compounds, naphthalocyanine compounds, croconium compounds. , At least one compound selected from the group consisting of porphyrin compounds and metal dithiolate compounds. Depending on the absorption characteristics of the compound (S) and the desired near-infrared transmission wavelength, by using the compound (S) in combination with other dye (X), the long wavelength side of the near-infrared transmission band in addition to the visible region Even in the case of 1, the incident angle dependency can be reduced, and good infrared sensing performance can be achieved.

  The content of the other dye (X) may be, for example, a substrate made of a transparent resin substrate (ii) containing the other dye (X) or the other dye (X) as the base (i). In the case of using a base material in which a resin layer such as an overcoat layer made of a curable resin or the like is laminated on the contained transparent resin substrate (ii), it is preferably 0.01 part with respect to 100 parts by weight of the transparent resin. To 1.5 parts by weight, more preferably 0.02 to 1.0 parts by weight, and particularly preferably 0.03 to 0.7 parts by weight, which serves as a glass support or a base as the base material (i). When a base material in which a transparent resin layer such as an overcoat layer made of another dye (X) and a curable resin is laminated on a resin support, a transparent resin layer containing the other dye (X) is used. Is preferably 0. To 4.0 parts by weight, more preferably 0.2 to 3.0 parts by weight, particularly preferably 0.3 to 2.0 parts by weight. When the content of the other dye (X) is within the above range, good near-infrared absorption characteristics and high visible light transmittance can both be achieved.

<Transparent resin>
The transparent resin substrate (ii) and the (transparent) resin layer laminated on the substrate (ii), the resin support, the glass support, or the like can be formed using a transparent resin.
As the transparent resin used for the base material (i), one kind may be used alone, or two or more kinds may be used.

The transparent resin is not particularly limited as long as it does not impair the effects of the present invention. For example, the high temperature vapor deposition that ensures thermal stability and moldability to a film, and is performed at a vapor deposition temperature of 100 ° C. or higher can be used to induce dielectric properties. A resin having a glass transition temperature (Tg) of preferably 110 to 380 ° C., more preferably 110 to 370 ° C., and further preferably 120 to 360 ° C. for use as a substrate capable of forming a body multilayer film. When the glass transition temperature of the resin is 140 ° C. or higher, a film ((transparent) resin layer and transparent resin substrate (ii)) capable of forming a dielectric multilayer film by vapor deposition at a higher temperature is obtained, which is particularly preferable.
Specifically, the Tg can be measured by the method described in the examples below.

  As the transparent resin, when a resin body having a thickness of 0.1 mm made of the resin is formed, the total light transmittance (JIS K7375) of the resin body is preferably 75% or more, more preferably 78% or more, Particularly preferably, a resin of 80% or more can be used. When a resin having a total light transmittance within such a range is used, the obtained substrate (i) shows good transparency as an optical film.

When a solvent-soluble resin is used as the transparent resin, the weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) method of the transparent resin is usually 15,000 to 350,000, It is preferably 30,000 to 250,000, and the number average molecular weight (Mn) is usually 10,000 to 150,000, preferably 20,000 to 100,000.
Mw and Mn can be specifically measured by the method described in the following examples.

  Examples of the transparent resin include cyclic (poly) olefin resin, aromatic polyether resin, polyimide resin, fluorene polycarbonate resin, fluorene polyester resin, polycarbonate resin, polyamide (aramid) resin, polyarylate resin. Resin, polysulfone resin, polyether sulfone resin, polyparaphenylene resin, polyamideimide resin, polyethylene naphthalate (PEN) resin, fluorinated aromatic polymer resin, (modified) acrylic resin, epoxy resin Examples thereof include resins, allyl ester-based curable resins, silsesquioxane-based UV-curable resins, acrylic UV-curable resins and vinyl-based UV-curable resins.

[Cyclic (poly) olefin resin]
The cyclic (poly) olefin resin is at least one monomer selected from the group consisting of a monomer represented by the following formula (X ₀ ) and a monomer represented by the following formula (Y ₀ ). And a resin obtained by hydrogenating the resin are preferable.

In formula (X ₀ ), R ^{x1 to} R ^x4 each independently represent an atom or a group selected from the following (i ′) to (ix ′), and k ^x , m ^x, and p ^x are each independently 0. Or it represents a positive integer.
(I ') hydrogen atom (ii') halogen atom (iii ') trialkylsilyl group (iv') having a linking group containing an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom,
Substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms (v ′) Substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms (vi ′) Polar group (however, excluding (iv ′))
(Vii ') R ^x1 and R ^x2 or R ^x3 and R ^x4 are bonded to each other to form an alkylidene group (provided that R ^{x1 to} R ^{x4 which} are not involved in the above-mentioned bond are independently the above-mentioned (i' ) To (vi ′) represents an atom or a group selected from
(Viii ') R ^x1 and R ^x2 or R ^x3 and R ^x4 are bonded to each other to form a monocyclic or polycyclic hydrocarbon ring or heterocycle (provided that R ^{x1 to} R which are not involved in the above-mentioned bond are combined). ^x4 represents an atom or a group independently selected from the above (i ') to (vi').)
(Ix ′) R ^x2 and R ^x3 are bonded to each other to form a monocyclic hydrocarbon ring or a heterocyclic ring (provided that R ^x1 and R ^{x4 which} are not involved in the above-mentioned bond are independently the above-mentioned (i Represents a atom or a group selected from ') to (vi').)

In formula (Y ₀ ), R ^y1 and R ^y2 each independently represent an atom or group selected from the above (i ′) to (vi ′), or R ^y1 and R ^y2 are bonded to each other. The formed monocyclic or polycyclic alicyclic hydrocarbon, aromatic hydrocarbon or heterocycle is represented, and k ^y and p ^y each independently represent 0 or a positive integer.

[Aromatic polyether resin]
The aromatic polyether-based resin preferably has at least one structural unit selected from the group consisting of structural units represented by the following formula (1) and structural units represented by the following formula (2).

In formula (1), R ^{1 to} R ⁴ each independently represent a monovalent organic group having 1 to 12 carbon atoms, and a to d each independently represent an integer of 0 to 4.

In formula (2), R ^{1 to} R ⁴ and a to d each independently have the same meaning as R ^{1 to} R ⁴ and a to d in formula (1), and Y is a single bond or —SO _2. -Or> C = O, R ⁷ and R ⁸ each independently represent a halogen atom, a monovalent organic group having 1 to 12 carbon atoms or a nitro group, and g and h each independently represent 0 to 4 Represents an integer, and m represents 0 or 1. However, when m is 0, R ⁷ is not a cyano group.

  Further, the aromatic polyether-based resin further has at least one structural unit selected from the group consisting of structural units represented by the following formula (3) and structural units represented by the following formula (4). Is preferred.

In formula (3), R ⁵ and R ⁶ each independently represent a monovalent organic group having 1 to 12 carbon atoms, and Z is a single bond, —O—, —S—, —SO ₂ —,> C = O, -CONH-, -COO- or a divalent organic group having 1 to 12 carbon atoms, e and f each independently represent an integer of 0 to 4, and n represents 0 or 1.

In formula (4), R ⁷ , R ⁸ , Y, m, g and h each independently have the same meaning as R ⁷ , R ⁸ , Y, m, g and h in formula (2), and R ⁵ , R ⁶ , Z, n, e and f each independently have the same meaning as R ⁵ , R ⁶ , Z, n, e and f in the formula (3).

[Polyimide resin]
The polyimide-based resin is not particularly limited as long as it is a high molecular compound containing an imide bond in a repeating unit, and is, for example, the method described in JP 2006-199945 A or JP 2008-163107 A. Can be synthesized.

[Fluorene polycarbonate resin]
The fluorene polycarbonate-based resin is not particularly limited as long as it is a polycarbonate resin containing a fluorene moiety, and is described in, for example, JP-A-2008-163194>

[Fluorene polyester resin]
The fluorene polyester resin is not particularly limited as long as it is a polyester resin containing a fluorene moiety, and for example, it may be synthesized by the method described in JP 2010-285505 A or JP 2011-197450 A. You can

[Fluorinated aromatic polymer resin]
The fluorinated aromatic polymer resin is not particularly limited, but is selected from the group consisting of an aromatic ring having at least one fluorine atom, an ether bond, a ketone bond, a sulfone bond, an amide bond, an imide bond and an ester bond. A polymer containing a repeating unit containing at least one bond is preferable and can be synthesized by, for example, the method described in JP-A-2008-181121.

[Acrylic UV curable resin]
The acrylic ultraviolet curable resin is not particularly limited, but is synthesized from a resin composition containing a compound having one or more acrylic group or methacrylic group in the molecule and a compound that decomposes by ultraviolet rays to generate active radicals. The resins mentioned may be mentioned. The acrylic ultraviolet curable resin is a base material (i) in which a transparent resin layer containing the compound (S) and a curable resin is laminated on a glass support or a resin support serving as a base. In the case of using a substrate in which a resin layer such as an overcoat layer made of a curable resin or the like is laminated on a transparent resin substrate (ii) containing the compound (S), it is particularly preferably used as the curable resin. be able to.

[Commercial goods]
Examples of commercially available transparent resins include the following commercially available products. Examples of commercially available cyclic (poly) olefin-based resins include JSR's Arton, Nippon Zeon's Zeonoa, Mitsui Chemicals 'APEL, Polyplastics' TOPAS, and the like. .. Examples of commercially available polyether sulfone-based resins include Sumika Excel PES manufactured by Sumitomo Chemical Co., Ltd. Examples of commercially available polyimide resins include Neoprim L manufactured by Mitsubishi Gas Chemical Co., Inc. Examples of commercially available polycarbonate-based resins include Pure Ace manufactured by Teijin Limited. Examples of commercially available fluorene polycarbonate-based resins include Upizeta EP-5000 manufactured by Mitsubishi Gas Chemical Co., Inc. Examples of commercially available fluorene polyester resins include OKP4HT manufactured by Osaka Gas Chemicals Co., Ltd. Commercially available products of the acrylic resin include ACRYVIEWR manufactured by Nippon Shokubai Co., Ltd. Examples of commercially available silsesquioxane UV-curable resins include Silplus manufactured by Nippon Steel Chemical Co., Ltd.

<Other ingredients>
The base material (i) may further contain other components such as an antioxidant, a near-ultraviolet absorber, a fluorescence quencher and a metal complex-based compound as long as the effects of the present invention are not impaired. Further, when the base material (i) is produced by cast molding described later, the production of the base material (i) can be facilitated by adding a leveling agent or an antifoaming agent. These other components may be used alone or in combination of two or more.

  Examples of the near-ultraviolet absorber include azomethine compounds, indole compounds, benzotriazole compounds, and triazine compounds.

  Examples of the antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,2′-dioxy-3,3′-di-t-butyl-5,5′-dimethyldiphenylmethane, and Tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane.

  In addition, these other components may be mixed with the resin or the like at the time of producing the base material (i), or may be added at the time of synthesizing the resin. The addition amount is appropriately selected according to the desired characteristics, but is usually 0.01 to 5.0 parts by weight, preferably 0.05 to 2.0 parts by weight, based on 100 parts by weight of the resin. ..

<Method for producing base material (i)>
When the base material (i) is a base material containing a transparent resin substrate (ii) containing the compound (S), the transparent resin substrate (ii) is formed by, for example, melt molding or cast molding. be able to.

  The base material (i) contains a resin layer such as an overcoat layer made of a curable resin or a compound (S) on a resin support or a transparent resin substrate (ii) serving as a glass support or a base. In the case of a substrate on which a transparent resin layer such as an overcoat layer made of a curable resin or the like is laminated, for example, a glass support or a resin support serving as a base or a transparent resin substrate (ii) may be used, if necessary. The resin solution containing the compound (S) is melt-molded or cast-molded, preferably by spin coating, slit coating, inkjet coating, or the like, and then the solvent is dried and removed. By heating, it is possible to produce a substrate having a (transparent) resin layer formed on a glass support, a resin support serving as a base, or a transparent resin substrate (ii).

[Melting]
As the melt-molding, specifically, a method of melt-kneading a pellet obtained by melt-kneading a resin and a compound (S) or the like, if necessary; a resin containing a resin and a compound (S) if necessary A method of melt-molding the composition; or a method of melt-molding pellets obtained by removing the solvent from the resin composition containing the resin and the solvent and optionally the compound (S). Examples of the melt molding method include injection molding, melt extrusion molding and blow molding.

[Cast molding]
As the cast molding, a method of casting a resin composition containing a resin and a solvent, and optionally a compound (S) on a suitable support to remove the solvent; or a photocurable resin and / or heat. By a method of casting a curable composition containing a curable resin and optionally a compound (S) on a suitable support to remove the solvent, and then curing the composition by an appropriate method such as ultraviolet irradiation or heating. It can also be manufactured.
When the base material (i) is a base material made of a transparent resin substrate (ii) containing the compound (S), the base material (i) is coated with a coating film from a support after cast molding. It can be obtained by peeling, and the base material (i) has a (transparent) resin layer on a support such as a glass support or a resin support serving as a base or a transparent resin substrate (ii). In the case of a laminated base material, the base material (i) can be obtained by removing the coating film after cast molding.

  Examples of the support include a glass plate, a steel belt, a steel drum, and a support made of a transparent resin (for example, a polyester film or a cyclic olefin resin film).

  Further, a glass plate, quartz or an optical component made of transparent plastic or the like is coated with the resin composition to dry the solvent, or the curable composition is coated to cure and dry the solution. It is also possible to form a transparent resin layer on the component.

  The amount of residual solvent in the (transparent) resin layer and the transparent resin substrate (ii) obtained by the above method is preferably as small as possible. Specifically, the residual solvent amount is preferably 3% by weight or less, more preferably 1% by weight or less, based on 100% by weight of the (transparent) resin layer or the transparent resin substrate (ii). It is preferably 0.5% by weight or less. When the amount of residual solvent is within the above range, a (transparent) resin layer and a transparent resin substrate (ii) which are less likely to undergo deformation or change in characteristics and can easily exhibit desired functions can be obtained.

[Dielectric multilayer film]
The dielectric multilayer film is preferably a film having the ability to cut unnecessary near infrared rays by reflection and to transmit the necessary near infrared rays. In the present invention, the dielectric multilayer film may be provided on one side or both sides of the substrate (i). When it is provided on one side, it is possible to obtain an optical filter which is excellent in manufacturing cost and easiness of production, and when it is provided on both sides, it has high strength and is less likely to warp.

  When the optical filter of the present invention is applied to uses such as a solid-state image sensor, it is preferable that the optical filter has a small warp. Therefore, it is preferable to provide the dielectric multilayer film on both surfaces of the substrate (i), The dielectric multilayer films may have the same or different spectral characteristics. When the dielectric multilayer films provided on both sides have the same spectral characteristics, the transmittances of the light stop bands Za and Zc can be efficiently reduced in the near infrared region, and the spectral characteristics of the dielectric multilayer films provided on both sides are If they are different, it tends to be easy to widen the ray stop band Zc to the longer wavelength side.

  Examples of the dielectric multilayer film include layers in which high refractive index material layers and low refractive index material layers are alternately laminated. As the material forming the high refractive index material layer, a material having a refractive index of 1.7 or more can be used, and a material having a refractive index of 1.7 to 2.5 is usually selected. Examples of such a material include titanium oxide, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, yttrium oxide, zinc oxide, zinc sulfide, indium oxide, and the like, and titanium oxide, tin oxide, and / or Alternatively, a material containing a small amount of cerium oxide or the like (for example, 0 to 10% by weight with respect to the main component) can be used.

  As the material forming the low refractive index material layer, a material having a refractive index of 1.6 or less can be used, and a material having a refractive index of 1.2 to 1.6 is usually selected. Such materials include, for example, silica, alumina, lanthanum fluoride, magnesium fluoride and sodium aluminum hexafluoride.

  The method for laminating the high refractive index material layer and the low refractive index material layer is not particularly limited as long as a dielectric multilayer film in which these material layers are laminated is formed. For example, the high refractive index material layer and the low refractive index material layer are formed by directly performing the CVD method, the sputtering method, the vacuum deposition method, the ion assisted deposition method, the ion plating method, or the like on the base material (i). It is possible to form dielectric multilayer films that are alternately laminated.

  The physical film thickness of each of the high refractive index material layer and the low refractive index material layer depends on the refractive index of each layer, but is usually preferably 5 to 500 nm, and is the total physical film thickness of the dielectric multilayer film. The value is preferably 1.0 to 8.0 μm for the entire optical filter.

  The total number of laminated layers of the high refractive index material layer and the low refractive index material layer in the dielectric multilayer film is preferably 16 to 70 layers, and more preferably 20 to 60 layers as a whole of the optical filter. When the thickness of each layer, the thickness of the dielectric multilayer film as the entire optical filter, and the total number of layers are within the above ranges, it is possible to secure a sufficient manufacturing margin and reduce the warp of the optical filter and the crack of the dielectric multilayer film. can do.

  In the present invention, the kind of material constituting the high refractive index material layer and the low refractive index material layer, the thickness of each layer of the high refractive index material layer and the low refractive index material layer, the stacking order, and the number of stacked layers should be appropriately selected. Thus, it is possible to obtain an optical filter having a light blocking band and a light transmitting band of a desired wavelength in the near infrared wavelength region while ensuring a sufficient transmittance in the visible region.

  Here, in order to optimize the conditions, for example, optical thin film design software (for example, Essential Macleod, manufactured by Thin Film Center) is used, and the transmittance of the wavelength region in which the transmission of light rays is desired to be suppressed in the near infrared wavelength region. The parameter may be set so that the transmittance is lowered and the transmittance in the wavelength region where the light beam is desired to be transmitted is increased. For example, when a light transmission band near 850 nm is provided by the dielectric multilayer films formed on both sides, the above software is used to set the target transmittance of one dielectric multilayer film at a wavelength of 770 to 810 nm to 0% and 830 to 870 nm. After setting the target transmittance of 100% to 100%, the value of Target Tolerance in each wavelength range is 0.5 or less, and the target transmittance of the other dielectric multilayer film at a wavelength of 830 to 870 nm is 100%, There is a parameter setting method in which the target transmittance of 900 to 1150 nm is set to 0% and the value of Target Tolerance in each wavelength range is set to 0.5 or less.

[Other functional films]
The optical filter of the present invention is, as far as the effect of the present invention is not impaired, between the base material (i) and the dielectric multilayer film, on the side opposite to the surface of the base material (i) on which the dielectric multilayer film is provided. The surface or the surface of the dielectric multilayer film opposite to the surface on which the base material (i) is provided, the surface hardness of the base material (i) and the dielectric multilayer film is improved, the chemical resistance is improved, and the antistatic property is improved. A functional film such as an antireflection film, a hard coat film, or an antistatic film can be appropriately provided for the purpose of scratch erasing or the like.

  The optical filter of the present invention may include one layer including the functional film, or may include two or more layers. When the optical filter of the present invention includes two or more layers composed of the functional film, the optical filter may include two or more layers similar to each other or two or more layers different from each other.

The method for laminating the functional film is not particularly limited, but a coating agent such as an antireflection agent, a hard coating agent and / or an antistatic agent is melted on the substrate (i) or the dielectric multilayer film in the same manner as described above. Examples thereof include a method of molding or cast molding.
It can also be produced by coating a curable composition containing the coating agent or the like on the substrate (i) or the dielectric multilayer film with a bar coater or the like, and then curing the composition by irradiating it with ultraviolet rays.

  Examples of the coating agent include ultraviolet (UV) / electron beam (EB) curable resins and thermosetting resins. Specifically, vinyl compounds, urethane-based, urethane acrylate-based, acrylate-based, epoxy And epoxy acrylate resins. Examples of the curable composition containing these coating agents include vinyl-based, urethane-based, urethane acrylate-based, acrylate-based, epoxy-based and epoxy acrylate-based curable compositions.

  Further, the curable composition may contain a polymerization initiator. As the polymerization initiator, a known photopolymerization initiator or thermal polymerization initiator can be used, and the photopolymerization initiator and the thermal polymerization initiator may be used in combination. The polymerization initiator may be used alone or in combination of two or more.

  In the curable composition, the compounding ratio of the polymerization initiator is preferably 0.1 to 10% by weight, more preferably 0.5 to 10% by weight, when the total amount of the curable composition is 100% by weight. More preferably, it is 1 to 5% by weight. When the blending ratio of the polymerization initiator is within the above range, the curable composition has excellent curing characteristics and handleability, and a functional film such as an antireflection film, a hard coat film or an antistatic film having a desired hardness can be obtained. it can.

Further, an organic solvent may be added to the curable composition as a solvent, and known organic solvents can be used. Specific examples of the organic solvent include alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene. Esters such as glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; ethers such as ethylene glycol monomethyl ether and diethylene glycol monobutyl ether; aromatic hydrocarbons such as benzene, toluene, xylene; dimethylformamide, dimethylacetamide, N- Examples thereof include amides such as methylpyrrolidone.
These solvents may be used alone or in combination of two or more.

  The thickness of the functional film is preferably 0.1 to 20 μm, more preferably 0.5 to 10 μm, and particularly preferably 0.7 to 5 μm.

  In addition, the base material (i), the functional film or the dielectric is used for the purpose of improving the adhesion between the base material (i) and the functional film and / or the dielectric multilayer film or the adhesion between the functional film and the dielectric multilayer film. The surface of the multilayer film may be subjected to surface treatment such as corona treatment or plasma treatment.

[Uses of optical filter]
The optical filter of the present invention has a wide viewing angle and can selectively transmit visible light and part of near infrared rays. Therefore, it is useful for the visibility correction of a solid-state image sensor such as a CCD or a CMOS image sensor having both a camera function and a near infrared sensing function. In particular, devices including camera modules such as digital still cameras, smartphone cameras, mobile phone cameras, digital video cameras, wearable device cameras, PC cameras, surveillance cameras, automobile cameras, night-vision cameras, motion capture, laser distance. It is useful for a total, virtual fitting, license plate recognition device, television, car navigation, personal digital assistant, video game machine, portable game machine, fingerprint authentication system, digital music player and the like.

[Solid-state imaging device]
The solid-state imaging device of the present invention includes the optical filter of the present invention. Here, the solid-state imaging device is an image sensor including a solid-state imaging device such as a CCD or a CMOS image sensor having a camera function and a near-infrared sensing function, and specifically, a digital still camera, a smartphone camera, a mobile phone. It can be used for applications such as telephone cameras, wearable device cameras, and devices including camera modules such as digital video cameras. For example, the camera module of the present invention includes the optical filter of the present invention, and further includes, for example, a lens unit and a sensor unit.

  Hereinafter, the present invention will be described more specifically based on Examples, but the present invention is not limited to these Examples. In addition, "parts" means "parts by weight" unless otherwise specified. Moreover, the measuring method of each physical property value and the evaluation method of physical property are as follows.

<Molecular weight>
The molecular weight of the resin obtained in the resin synthesis example was measured by the method (a) or (b) below in consideration of the solubility of each resin in a solvent.

  (A) Using a gel permeation chromatography (GPC) device (150C type, column: H type column manufactured by Tosoh Corp., developing solvent: o-dichlorobenzene) manufactured by WATERS, weight in terms of standard polystyrene The average molecular weight (Mw) and the number average molecular weight (Mn) were measured.

  (B) Using a GPC device (HLC-8220 type, column: TSKgel α-M, developing solvent: tetrahydrofuran) manufactured by Tosoh Corporation, the weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of standard polystyrene are measured. did.

For the resin synthesized in Resin Synthesis Example 3 to be described later, the logarithmic viscosity was measured by the following method (c) instead of the measurement of the molecular weight by the above method.
(C) A part of the polyimide resin solution was poured into anhydrous methanol to precipitate the polyimide resin, and the unreacted monomer was separated by filtration. 0.1 g of the polyimide obtained by vacuum drying at 80 ° C. for 12 hours was dissolved in 20 mL of N-methyl-2-pyrrolidone, and the diluted polymer solution obtained was used to measure 30 using a Canon-Fenske viscometer. The logarithmic viscosity (μ) at ° C was calculated by the following formula.
μ = {ln (t _s / t ₀ )} / C
t ₀ : Solvent flow-down time t _s : Dilute polymer solution flow-down time C: 0.5 g / dL

<Glass transition temperature (Tg)>
The Tg of the resin obtained in the resin synthesis example was measured using a differential scanning calorimeter (DSC6200) manufactured by SII Nano Technologies, Inc. at a heating rate of 20 ° C./min under a nitrogen stream.

<Spectral transmittance>
(Ta), (Xc), (Tb) and (Xf) of the base material, and the transmittances (Xa), (Xb), (Xd), (Xe) and (Xa ′ of each wavelength region of the optical filter. ) Was measured using a spectrophotometer (U-4100) manufactured by Hitachi High-Technologies Corporation. The optical characteristics of the base material used in the comparative example were measured in the same manner as (Ta), (Xc), (Tb) or (Xf).

  Here, as for the transmittance when measured from the vertical direction of the optical filter, the light transmitted perpendicularly to the filter was measured as shown in FIG. As for the transmittance when measured from an angle of 30 ° with respect to the vertical direction of the optical filter, the light transmitted at an angle of 30 ° with respect to the vertical direction of the filter was measured as shown in FIG.

[Synthesis example]
The compound (S) and the compound (A) used in the following examples can be synthesized by a generally known method. For example, Japanese Patent No. 3094037, Japanese Patent No. 3703869, and Japanese Patent Laid-Open No. Sho 60 are disclosed. No. 228448, Japanese Patent Application Laid-Open No. 1-146846, Japanese Patent Application Laid-Open No. 1-2228960, Japanese Patent No. 4081149, Japanese Patent Application Laid-Open No. 63-124054, “Phthalocyanine: Chemistry and Function” (IPC, 1997). ), JP-A 2007-169315, JP-A 2009-108267, JP-A 2010-241873, JP-A No. 3699464, JP-A No. 4740631, and the like. be able to.

<Resin synthesis example 1>
8-Methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 100 parts of ^1,7,10 ] dodeca-3-ene, 18 parts of 1-hexene (molecular weight modifier) and 300 parts of toluene (solvent for ring-opening polymerization reaction) were charged in a reaction vessel purged with nitrogen, and the resulting solution was prepared. Heated to 80 ° C. Then, 0.2 parts of a toluene solution of triethylaluminum (concentration: 0.6 mol / liter) and a toluene solution of methanol-modified tungsten hexachloride (concentration: 0.025 mol / liter) were added to the solution in the reaction vessel as a polymerization catalyst. And 0.9 part were added and the mixture was heated and stirred at 80 ° C. for 3 hours to cause ring-opening polymerization to obtain a ring-opening polymer solution. The polymerization conversion rate in this polymerization was 97%.

1,000 parts of the ring-opening polymer solution thus obtained was charged into an autoclave, and 0.12 parts of RuHCl (CO) [P (C ₆ H ₅ ) ₃ ] ₃ was added to the ring-opening polymer solution. Then, under the conditions of a hydrogen gas pressure of 100 kg / cm ² and a reaction temperature of 165 ° C., the mixture was heated and stirred for 3 hours to carry out a hydrogenation reaction. After cooling the obtained reaction solution (hydrogenated polymer solution), hydrogen gas was released. The reaction solution was poured into a large amount of methanol to separate and collect a coagulated product, which was dried to obtain a hydrogenated polymer (hereinafter also referred to as "resin A"). The resin A thus obtained had a number average molecular weight (Mn) of 32,000, a weight average molecular weight (Mw) of 137,000 and a glass transition temperature (Tg) of 165 ° C.

<Resin synthesis example 2>
35.12 g (0.253 mol) of 2,6-difluorobenzonitrile, 87.60 g (0.250 mol) of 9,9-bis (4-hydroxyphenyl) fluorene, and 41.46 g of potassium carbonate were added to a 3 L four-necked flask. 0.300 mol), 443 g of N, N-dimethylacetamide (hereinafter also referred to as "DMAc") and 111 g of toluene were added. Subsequently, a thermometer, a stirrer, a three-way cock with a nitrogen introduction tube, a Dean-Stark tube and a cooling tube were attached to the four-necked flask. Next, after replacing the inside of the flask with nitrogen, the obtained solution was reacted at 140 ° C. for 3 hours, and the produced water was removed from the Dean-Stark tube at any time. When the generation of water was no longer observed, the temperature was gradually raised to 160 ° C. and the reaction was carried out at that temperature for 6 hours. After cooling to room temperature (25 ° C.), the produced salt was removed with a filter paper, the filtrate was poured into methanol for reprecipitation, and the filter cake (residue) was isolated by filtration. The obtained filter cake was vacuum dried at 60 ° C. overnight to obtain a white powder (hereinafter, also referred to as “resin B”) (yield 95%). The resulting resin B had a number average molecular weight (Mn) of 75,000, a weight average molecular weight (Mw) of 188,000, and a glass transition temperature (Tg) of 285 ° C.

<Resin synthesis example 3>
In a 500 mL five-necked flask equipped with a thermometer, a stirrer, a nitrogen introduction tube, a dropping funnel with a side tube, a Dean-Stark tube and a cooling tube, under a nitrogen stream, 1,4-bis (4-amino-α, α) -Dimethylbenzyl) benzene (27.66 g (0.08 mol)) and 4,4'-bis (4-aminophenoxy) biphenyl 7.38 g (0.02 mol) were added, and γ-butyrolactone 68.65 g and DMAc17. It was dissolved in 16 g. The resulting solution was cooled to 5 ° C. using an ice water bath and, while maintaining the same temperature, 22.62 g (0.1 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and an imidization catalyst. Then, 0.50 g (0.005 mol) of triethylamine was added all at once. After the addition was completed, the temperature was raised to 180 ° C., and the mixture was refluxed for 6 hours while distilling off the distillate as needed. After refluxing for 6 hours, the mixture was air-cooled until the internal temperature reached 100 ° C., 143.6 g of DMAc was added for dilution, and the mixture was cooled with stirring to obtain 264.16 g of a polyimide resin solution having a solid content concentration of 20% by weight. .. A part of this polyimide resin solution was poured into 1 L of methanol to precipitate the polyimide. The filtered polyimide was washed with methanol and then dried in a vacuum dryer at 100 ° C. for 24 hours to obtain a white powder (hereinafter also referred to as “resin C”).

The IR spectrum of the obtained resin C was measured, 1704 cm ^-1 characteristic of imido group, absorption of 1770 cm ^-1 were observed. The resin C had a glass transition temperature (Tg) of 310 ° C. and a logarithmic viscosity of 0.87.

[Example 1]
In Example 1, an optical filter having a base material made of a transparent resin substrate was prepared according to the following procedure and conditions.
In a container, 100 parts of Resin A obtained in Resin Synthesis Example 1, 0.03 part of compound (s-5) (absorption maximum wavelength 770 nm in dichloromethane) described in Table 1 as compound (S) and methylene chloride. Was added to prepare a solution having a resin concentration of 20% by weight. The obtained solution was cast on a smooth glass plate, dried at 20 ° C. for 8 hours, and then peeled from the glass plate. The peeled coating film was further dried under reduced pressure at 100 ° C. for 8 hours to obtain a substrate made of a transparent resin substrate having a thickness of 0.1 mm, a length of 60 mm, and a width of 60 mm. The spectral transmittance of this base material was measured to determine (Ta), (Tb), (Xc) and (Xf). The results are shown in FIG. 3 and Table 7.

Then, a dielectric multilayer film (I) is formed on one surface of the obtained base material, and a dielectric multilayer film (II) is further formed on the other surface of the base material. I got a filter.
The dielectric multilayer film (I) is formed by alternately stacking silica (SiO ₂ ) layers and titania (TiO ₂ ) layers at a vapor deposition temperature of 100 ° C. (total of 24 layers). The dielectric multilayer film (II) is formed by alternately stacking silica (SiO ₂ ) layers and titania (TiO ₂ ) layers at a deposition temperature of 100 ° C. (18 layers in total). In each of the dielectric multilayer films (I) and (II), the silica layer and the titania layer are, in order from the substrate side, a titania layer, a silica layer, a titania layer, ... A silica layer, a titania layer, and a silica layer. The layers were alternately laminated, and the outermost layer of the optical filter was a silica layer.

The dielectric multilayer films (I) and (II) were designed as follows.
Regarding the thickness and number of layers, the wavelength dependence characteristics of the base material refractive index and the absorption characteristics of the compound (S) used so that the antireflection effect in the visible range and the selective transmission / reflection performance in the near infrared range can be achieved. Optimization was performed using optical thin film design software (Essential Maclede, manufactured by Thin Film Center). When performing the optimization, in this example, the input parameters (Target value) to the software are shown in Table 2 below.

  As a result of the optimization of the film structure, in Example 1, the dielectric multilayer film (I) was formed by alternately stacking a silica layer having a thickness of about 13 to 174 nm and a titania layer having a thickness of about 9 to 200 nm. The multilayer vapor deposition film of the number 24 is obtained, and the dielectric multilayer film (II) is a multilayer of the number 18 of laminations in which a silica layer having a thickness of about 41 to 198 nm and a titania layer having a thickness of about 12 to 122 nm are alternately laminated. It became a vapor deposition film. Table 3 shows an example of the optimized film structure.

  The spectral transmittance of the obtained optical filter was measured in the vertical direction and at an angle of 30 ° with respect to the vertical direction, and the optical characteristics in each wavelength region were evaluated. The results are shown in FIG. 4 and Table 7.

[Example 2]
In Example 1, 0.03 part of the compound (s-11) described in Table 1 (absorption maximum wavelength in dichloromethane: 776 nm) was used in place of 0.03 part of the compound (s-5), and As the compound (A), 0.03 parts of the compound (a-1) represented by the following formula (a-1) (absorption maximum wavelength 698 nm in dichloromethane) and the following formula (a-2) are represented. A transparent resin containing the compound (S) and the compound (A) in the same procedure and conditions as in Example 1 except that 0.03 part of the compound (a-2) (absorption maximum wavelength in dichloromethane: 733 nm) was used. A base material made of a substrate was obtained. The spectral transmittance of this base material was measured to determine (Ta), (Tb), (Xc) and (Xf). The results are shown in FIG. 5 and Table 7.

Then, as in Example 1, a dielectric multi-layer film (III in which silica (SiO ₂ ) layers and titania (TiO ₂ ) layers were alternately laminated on one surface of the obtained substrate (total of 24 layers). ) Is formed on the other surface of the substrate, and a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated (total 18 layers) to form a dielectric multilayer film (IV). An optical filter having a thickness of about 0.104 mm was obtained. The dielectric multilayer film was designed using the design parameters as shown in Table 4 below in consideration of the wavelength dependence of the refractive index of the base material.

  As a result of the optimization of the film structure, in Example 2, the dielectric multilayer film (III) was formed by alternately stacking a silica layer having a film thickness of about 27 to 198 nm and a titania layer having a film thickness of about 10 to 121 nm. The multilayer vapor deposition film of the number 24 is obtained, and the dielectric multilayer film (IV) is a multilayer of the number 18 of laminations in which a silica layer having a thickness of about 41 to 198 nm and a titania layer having a thickness of about 12 to 122 nm are alternately laminated. It became a vapor deposition film. Table 5 shows an example of the optimized film structure.

  The spectral transmittance of the obtained optical filter was measured to evaluate the optical characteristics in each wavelength region. The results are shown in FIG. 6 and Table 7.

[Example 3]
In Example 3, an optical filter having a base material made of a transparent resin substrate having resin layers on both sides was prepared according to the following procedure and conditions.
In Example 1, except that 0.03 part of the compound (s-23) (absorption maximum wavelength 784 nm in dichloromethane) described in Table 1 was used in place of 0.03 part of the compound (s-5). A transparent resin substrate containing the compound (S) was obtained according to the same procedure and conditions as in Example 1.

The resin composition (1) having the following composition was applied to one surface of the obtained transparent resin substrate with a bar coater and heated in an oven at 70 ° C. for 2 minutes to volatilize and remove the solvent. At this time, the coating conditions of the bar coater were adjusted so that the thickness after drying was 2 μm. Next, exposure (exposure amount: 500 mJ / cm ² , 200 mW) was performed using a conveyor type exposure machine to cure the resin composition (1) and form a resin layer on the transparent resin substrate. Similarly, a resin layer is formed using the resin composition (1) on the other surface of the transparent resin substrate to obtain a base material having a resin layer on both surfaces of the transparent resin substrate containing the compound (S). It was The spectral transmittance of this base material was measured to determine (Ta), (Tb), (Xc) and (Xf). The results are shown in Table 7.

  Resin composition (1) (solid content concentration (TSC): 30%): 60 parts by weight of tricyclodecane dimethanol acrylate, 40 parts by weight of dipentaerythritol hexaacrylate, 5 parts by weight of 1-hydroxycyclohexyl phenyl ketone, methyl ethyl ketone (solvent) )

Then, as in Example 1, a dielectric multilayer film (V) in which silica (SiO ₂ ) layers and titania (TiO ₂ ) layers were alternately laminated on one surface of the obtained base material (total of 24 layers). ) Is formed on the other surface of the base material, and a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated (18 layers in total) to form a dielectric multilayer film (VI). An optical filter having a thickness of about 0.108 mm was obtained. The dielectric multilayer film was designed by using the same design parameters as in Example 1 in consideration of the wavelength dependence of the refractive index of the base material as in Example 1. The spectral transmittance of this optical filter was measured to evaluate the optical characteristics in each wavelength region. The results are shown in Table 7.

[Example 4]
In Example 3, instead of 0.03 part of compound (s-23), 0.01 part of compound (s-5) described in Table 1 and compound (s-21) described in Table 1 (in dichloromethane) In the same procedure and conditions as in Example 3, except that 0.02 part of the maximum absorption wavelength at 782 nm) was used, a base material having resin layers on both surfaces of a transparent resin substrate containing the compound (S) was obtained. .. The spectral transmittance of this base material was measured to determine (Ta), (Tb), (Xc) and (Xf). The results are shown in Table 7.

Subsequently, as in Example 1, a dielectric multilayer film (VII) in which a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer were alternately laminated on one surface of the obtained substrate (total of 24 layers). ) Is formed on the other surface of the base material, and a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated (total 18 layers) to form a dielectric multilayer film (VIII). An optical filter having a thickness of about 0.108 mm was obtained. The dielectric multilayer film was designed by using the same design parameters as in Example 1 in consideration of the wavelength dependence of the refractive index of the base material as in Example 1. The spectral transmittance of this optical filter was measured to evaluate the optical characteristics in each wavelength region. The results are shown in Table 7.

[Example 5]
In Example 3, 0.04 part of the compound (s-11) described in Table 1 was used instead of 0.03 part of the compound (s-23), and the following formula was used as the compound (A). 0.02 part of compound (a-3) represented by (a-3) (absorption maximum wavelength 703 nm in dichloromethane) and compound (a-4) represented by the following formula (a-4) (in dichloromethane) In the same procedure and conditions as in Example 3 except that 0.06 part of the absorption maximum wavelength in Example 1 was used, a base material having resin layers on both surfaces of a transparent resin substrate containing the compound (S) was obtained. .. The spectral transmittance of this base material was measured to determine (Ta), (Tb), (Xc) and (Xf). The results are shown in Table 7.

Then, as in Example 1, a dielectric multilayer film (IX) in which silica (SiO ₂ ) layers and titania (TiO ₂ ) layers were alternately laminated on one surface of the obtained substrate (total of 24 layers). ) Is formed on the other surface of the base material, and a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated (18 layers in total) to form a dielectric multilayer film (X). An optical filter having a thickness of about 0.108 mm was obtained. The dielectric multilayer film was designed by using the same design parameters as in Example 2 in consideration of the wavelength dependence of the refractive index of the base material as in Example 1. The spectral transmittance of this optical filter was measured to evaluate the optical characteristics in each wavelength region. The results are shown in Table 7.

[Example 6]
In Example 6, an optical filter having a base material made of a resin substrate having a transparent resin layer containing the compound (S) on both surfaces was prepared according to the following procedure and conditions.
Resin A obtained in the same manner as in Example 1 except that the resin A obtained in Resin Synthesis Example 1 and methylene chloride were added to a container to prepare a solution having a resin concentration of 20% by weight, and the obtained solution was used. A substrate was made.

  A transparent resin layer was formed on both surfaces of the obtained resin substrate in the same manner as in Example 3 except that the resin composition (2) having the following composition was used instead of the resin composition (1), and the compound was formed on both surfaces. A base material made of a resin substrate having a transparent resin layer containing (S) was obtained. The spectral transmittance of this base material was measured to determine (Ta), (Tb), (Xc) and (Xf). The results are shown in Table 7.

  Resin composition (2) (TSC: 25%): tricyclodecane dimethanol acrylate 100 parts by weight, 1-hydroxycyclohexyl phenyl ketone 4 parts by weight, compound (s-5) 0.75 parts by weight, compound (a-2) ) 0.75 part by weight, compound (a-3) 0.75 part by weight, methyl ethyl ketone (solvent)

Subsequently, as in Example 1, a dielectric multilayer film (XI) in which silica (SiO ₂ ) layers and titania (TiO ₂ ) layers were alternately laminated on one surface of the obtained substrate (total of 24 layers). ) Is formed, and a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated on the other surface of the substrate (18 layers in total) to form a dielectric multilayer film (XII). An optical filter having a thickness of about 0.110 mm was obtained. The dielectric multilayer film was designed by using the same design parameters as in Example 2 in consideration of the wavelength dependence of the refractive index of the base material as in Example 1. The spectral transmittance of this optical filter was measured to evaluate the optical characteristics in each wavelength region. The results are shown in Table 7.

[Example 7]
In Example 7, an optical filter having a base material made of a transparent glass substrate having a transparent resin layer containing the compound (S) on one surface was prepared according to the following procedure and conditions.
A resin composition (3) having the following composition was applied by a spin coater on a transparent glass substrate “OA-10G (thickness 200 μm)” (manufactured by Nippon Electric Glass Co., Ltd.) cut into a size of 60 mm in length and 60 mm in width, A coating film was formed by heating on a hot plate at 80 ° C. for 2 minutes to volatilize and remove the solvent. At this time, the coating conditions of the spin coater were adjusted so that the thickness after drying was 2 μm. Next, exposure (exposure amount 500 mJ / cm ² , 200 mW) is performed using a conveyor type exposure machine to cure the coating film, and a substrate made of a transparent glass substrate having a transparent resin layer containing the compound (S) is obtained. Obtained. The spectral transmittance of this base material was measured to determine (Ta), (Tb), (Xc) and (Xf). The results are shown in Table 7.

  Resin composition (3) (TSC: 35%): 20 parts by weight of tricyclodecane dimethanol acrylate, 80 parts by weight of dipentaerythritol hexaacrylate, 4 parts by weight of 1-hydroxycyclohexyl phenyl ketone, compound (s-5) 1. 5 parts by weight, compound (a-2) 1.5 parts by weight, compound (a-3) 1.5 parts by weight, methyl ethyl ketone (solvent)

Then, as in Example 1, a dielectric multilayer film (XIII) in which a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer were alternately laminated on one surface of the obtained substrate (total of 24 layers). ) Is formed on the other surface of the substrate, and a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated (total 18 layers) to form a dielectric multilayer film (XIV). An optical filter having a thickness of about 0.210 mm was obtained. The dielectric multilayer film was designed by using the same design parameters as in Example 2 in consideration of the wavelength dependence of the refractive index of the base material as in Example 1. The spectral transmittance of this optical filter was measured to evaluate the optical characteristics in each wavelength region. The results are shown in Table 7.

[Comparative Example 1]
A base material was prepared in the same manner as in Example 1 except that the compound (S) was not used. Subsequently, as in Example 1, a dielectric multilayer film (XV) in which a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer were alternately laminated on one surface of the obtained substrate (total of 24 layers). ) Is formed on the other surface of the base material, and a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated (total 18 layers) to form a dielectric multilayer film (XVI). An optical filter having a thickness of about 0.106 mm was obtained. The dielectric multilayer film was designed using the same design parameters as in Example 1 after considering the wavelength dependence of the refractive index of the base material. The spectral transmittance of this optical filter was measured to evaluate the optical characteristics in each wavelength region. The results are shown in FIG. 7 and Table 7.

[Comparative example 2]
Similar to Example 1, except that a near infrared ray absorbing glass substrate “BS-6 (210 μm in thickness)” (manufactured by Matsunami Glass Industry Co., Ltd.) cut into a size of 60 mm in length and 60 mm in width was used as a base material. Then, a dielectric multilayer film (XVII) in which a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated (24 layers in total) is formed on one surface of the substrate, and An optical filter having a thickness of about 0.216 mm is formed on one surface by forming a dielectric multilayer film (XVIII) in which silica (SiO ₂ ) layers and titania (TiO ₂ ) layers are alternately laminated (total of 18 layers). Got The dielectric multilayer film was designed by using the design parameters as shown in Table 6 below in consideration of the wavelength dependence of the refractive index of the base material. The spectral transmittance of this optical filter was measured to evaluate the optical characteristics in each wavelength region. The results are shown in FIG. 8 and Table 7.

[Comparative Example 3]
A group similar to Example 1 except that 0.03 parts of the compound (a-2) and 0.03 part of the compound (a-3) were used in place of the compound (S) in Example 1. I made wood.

Then, as in Example 1, a dielectric multilayer film (XIX) in which silica (SiO ₂ ) layers and titania (TiO ₂ ) layers were alternately laminated on one surface of the obtained substrate (total 24). And a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated on the other surface of the base material (total 18 layers) to form a dielectric multilayer film (XX), An optical filter having a thickness of about 0.106 mm was obtained. The dielectric multilayer film was designed using the same design parameters as in Example 2 after considering the wavelength dependence of the refractive index of the base material. The spectral transmittance of this optical filter was measured to evaluate the optical characteristics in each wavelength region. The results are shown in Table 7.

[Comparative Example 4]
As in Example 1, except that a transparent glass substrate “OA-10G (thickness 200 μm)” (manufactured by Nippon Electric Glass Co., Ltd.) cut into a size of 60 mm in length and 60 mm in width was used as a base material. , A silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated on one side of the substrate (total of 24 layers) to form a dielectric multilayer film (XXI), and further, on the other side of the substrate. A silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated on the surface (20 layers in total) to form a dielectric multilayer film (XXII), and an optical filter having a thickness of about 0.206 mm is obtained. It was The dielectric multilayer film was designed using the same design parameters as in Example 1 after considering the wavelength dependence of the refractive index of the base material. The spectral transmittance of this optical filter was measured to evaluate the optical characteristics in each wavelength region. The results are shown in Table 7.

[Examples 8 to 13]
A substrate and an optical filter were prepared in the same manner as in Example 5 except that the resin, solvent, drying conditions of the resin substrate, compound (S) and compound (A) were changed as shown in Table 7. Table 7 shows the optical properties of the obtained substrate and optical filter.

  The constitution of the base material and various compounds applied in the examples and comparative examples are as follows.

<Form of base material>
Form (1): transparent resin substrate containing compound (S) Form (2): transparent resin substrate containing compound (S) has resin layers on both sides Form (3): compound (S) on both sides of resin substrate Form (4): A transparent resin layer containing S) is included. Form (4): A transparent resin layer containing the compound (S) is provided on one surface of the glass substrate. Form (5): Resin substrate not containing the compound (S) (Comparative Example). )
Form (6): Near infrared absorbing glass substrate (comparative example)
Form (7): Glass substrate (comparative example)

<Transparent resin>
Resin A: Cyclic olefin resin (resin synthesis example 1)
Resin B: Aromatic polyether resin (resin synthesis example 2)
Resin C: Polyimide resin (resin synthesis example 3)
Resin D: Cyclic olefin resin "Zeonor 1420R" (manufactured by Nippon Zeon Co., Ltd.)

<Glass substrate>
Glass substrate (1): Transparent glass substrate “OA-10G (thickness 200 μm)” cut into a size of 60 mm in length and 60 mm in width (manufactured by Nippon Electric Glass Co., Ltd.)
Glass substrate (2): Near-infrared absorbing glass substrate “BS-6 (thickness 210 μm)” cut into a size of 60 mm in length and 60 mm in width (manufactured by Matsunami Glass Industry Co., Ltd.)

<Compound (S)>
Compound (s-5): Compound (s-5) described in Table 1 (absorption maximum wavelength in dichloromethane: 770 nm)
Compound (s-11): Compound (s-11) described in Table 1 (absorption maximum wavelength in dichloromethane: 776 nm)
Compound (s-21): Compound (s-21) described in Table 1 (absorption maximum wavelength in dichloromethane: 782 nm)
Compound (s-23): Compound (s-23) described in Table 1 above (absorption maximum wavelength in dichloromethane: 784 nm)

<Compound (A)>
Compound (a-1): Compound (a-1) (absorption maximum wavelength in dichloromethane 698 nm)
Compound (a-2): the compound (a-2) (absorption maximum wavelength 733 nm in dichloromethane)
Compound (a-3): the compound (a-3) (absorption maximum wavelength in dichloromethane: 703 nm)
Compound (a-4): the compound (a-4) (absorption maximum wavelength in dichloromethane: 736 nm)

<Solvent>
Solvent (1): Methylene chloride Solvent (2): N, N-dimethylacetamide Solvent (3): Cyclohexane / xylene (weight ratio: 7/3)

<Resin substrate drying conditions>
The drying conditions for the (transparent) resin substrates of Examples and Comparative Examples in Table 7 are as follows. The coating film was peeled from the glass plate before drying under reduced pressure.
Condition (1): 20 ° C./8 hr → under reduced pressure 100 ° C./8 hr
Condition (2): 60 ° C./8 hr → 80 ° C./8 hr → under reduced pressure 140 ° C./8 hr
Condition (3): 60 ° C./8 hr → 80 ° C./8 hr → under reduced pressure 100 ° C./24 hr

<Resin layer forming composition>
The resin composition forming the resin layer in the examples of Table 7 is as follows.
Resin composition (1) (TSC: 30%): tricyclodecane dimethanol acrylate 60 parts by weight, dipentaerythritol hexaacrylate 40 parts by weight, 1-hydroxycyclohexyl phenyl ketone 5 parts by weight, methyl ethyl ketone (solvent)
Resin composition (2) (TSC: 25%): tricyclodecane dimethanol acrylate 100 parts by weight, 1-hydroxycyclohexyl phenyl ketone 4 parts by weight, compound (s-5) 0.75 parts by weight, compound (a-2) ) 0.75 part by weight, compound (a-3) 0.75 part by weight, methyl ethyl ketone (solvent)
Resin composition (3) (TSC: 35%): 20 parts by weight of tricyclodecane dimethanol acrylate, 80 parts by weight of dipentaerythritol hexaacrylate, 4 parts by weight of 1-hydroxycyclohexyl phenyl ketone, compound (s-5) 1. 5 parts by weight, compound (a-2) 1.5 parts by weight, compound (a-3) 1.5 parts by weight, methyl ethyl ketone (solvent)

  The optical filter of the present invention includes a digital still camera, a smartphone camera, a mobile phone camera, a digital video camera, a wearable device camera, a PC camera, a surveillance camera, an automobile camera, a night vision camera, a motion capture, a laser rangefinder, It can be suitably used for virtual fitting, license plate recognition device, television, car navigation, personal digital assistant, personal computer, video game machine, portable game machine, fingerprint authentication system, digital music player and the like.

1: Optical filter 2: Spectrophotometer 3: Light

Claims (15)

An optical filter that selectively transmits visible light and part of near infrared rays,
It has a light ray stop band Za, a light ray transmission band Zb, and a light ray stop band Zc in the wavelength region of 650 nm or more, and the center wavelength of each band is Za <Zb <Zc,
The transmittance at a wavelength of 800 nm when measured from the vertical direction of the optical filter is 20% or less, and the transmittance when measured from the direction of 30 ° with respect to the vertical direction of the optical filter is 50% or less,
Of the Zb, the value of the wavelength on the shortest wavelength side, which has a transmittance of 50% when measured from the vertical direction of the optical filter, is (Xa),
In the band corresponding to Zb, the transmittance is 50% when measured from an angle of 30 ° with respect to the vertical direction of the optical filter, and the value of the wavelength on the shortest wavelength side is (Xa ′),
An optical filter having | Xa-Xa ′ | of 30 nm or less.   The optical filter according to claim 1, which has an average transmittance of 75% or more when measured in the vertical direction of the optical filter in a wavelength range of 430 to 580 nm.   In the wavelength range of 700 to 800 nm, the average value of the transmittance when measured from the vertical direction of the optical filter is 5% or less, and the transmittance when measured from the direction of 30 ° with respect to the vertical direction of the optical filter. The optical filter according to claim 1 or 2, which has an average value of 10% or less.   Of the Zb, the difference Xb between the value of the wavelength on the shortest wavelength side (Xa) and the value of the wavelength on the longest wavelength side (Xb), which has a transmittance of 50% when measured from the vertical direction of the optical filter. -Xa is 5-150 nm, The value of Y represented by Y = (Xa + Xb) / 2 is 820-950 nm, The optical filter of any one of Claims 1-3.   The wavelength value (Xa) on the shortest wavelength side of the Zb, which has a transmittance of 50% when measured from the direction perpendicular to the optical filter, is 810 to 900 nm, and any one of claims 1 to 4. An optical filter according to item.   The minimum transmittance of each of the Za and Zc measured in the vertical direction of the optical filter is 4% or less, and the maximum transmittance of the Zb measured in the vertical direction of the optical filter is 55% or more. Item 6. The optical filter according to any one of Items 1 to 5. Among the Zb, the wavelength value on the shortest wavelength side, which has a transmittance of 50% when measured from the vertical direction of the optical filter, is Xa, the wavelength value on the longest wavelength side is Xb, and (Xa + Xb) / When the value of 2 is Y,
The optical filter according to any one of claims 1 to 6, wherein the average transmittance measured in the vertical direction of the optical filter in the wavelength range of Y-10 nm to Y + 10 nm is 60% or more.   The optical filter has a base material (i), and the base material (i) has a transparent resin layer containing a compound (S) having an absorption maximum at a wavelength of 750 to 850 nm. An optical filter according to item. The optical filter according to claim 8, wherein the compound (S) is a compound represented by the following formula (S1).
[In the formula (S1), X independently represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom or —NR ⁸ —,
R ^{1 to} R ⁸ are each independently a hydrogen atom, halogen atom, sulfo group, hydroxyl group, cyano group, nitro group, carboxy group, phosphoric acid group, —NR ^g R ^h group, —SO ₂ R ⁱ group, —OSO. It represents either ₂ R ⁱ group or a group represented by L ^a ~L ^h, are each R ^g and R ^h independently represent any of hydrogen atom, -C (O) R ⁱ groups or the following L ^a ~L ^e , R ⁱ represents any of the following L ^a ~L ^e,
(L ^a ) C 1-12 aliphatic hydrocarbon group (L ^b ) ^C 1-12 halogen-substituted alkyl group (L ^c ) ^C 3-14 alicyclic hydrocarbon group (L ^d ) carbon Number of carbon atoms which may have an aromatic hydrocarbon group (L ^e ) having 6 to 14 carbon atoms, a heterocyclic group having 3 to 14 carbon atoms (L ^f ) and an alkoxy group having 1 to 12 carbon atoms (L ^g ) substituent L 1-12 acyl group (L ^h ) C1-C12 alkoxycarbonyl group which may have a substituent L The substituent L is a C1-C12 aliphatic hydrocarbon group, a C1-C12 At least one selected from the group consisting of a halogen-substituted alkyl group having 3 to 14 carbon atoms, an alicyclic hydrocarbon group having 3 to 14 carbon atoms, an aromatic hydrocarbon group having 6 to 14 carbon atoms, and a heterocyclic group having 3 to 14 carbon atoms. is there. ]   The optical filter according to claim 8, wherein the transparent resin layer contains, in addition to the compound (S), a compound (A) having an absorption maximum at a wavelength of 600 nm or more and less than 750 nm.   The transparent resin layer is a cyclic (poly) olefin resin, aromatic polyether resin, polyimide resin, fluorene polycarbonate resin, fluorene polyester resin, polycarbonate resin, polyamide resin, polyarylate resin, polysulfone resin. Resin, polyether sulfone resin, polyparaphenylene resin, polyamideimide resin, polyethylene naphthalate resin, fluorinated aromatic polymer resin, (modified) acrylic resin, epoxy resin, allyl ester curing type The resin, at least one resin selected from the group consisting of silsesquioxane-based UV-curable resin, acrylic UV-curable resin and vinyl-based UV-curable resin is contained in any one of claims 8 to 10. The optical filter described.   The optical filter according to any one of claims 8 to 11, which has a dielectric multilayer film on at least one surface of the base material (i).   The optical filter according to claim 1, which is for a solid-state imaging device.   A solid-state imaging device comprising the optical filter according to claim 1.   A camera module comprising the optical filter according to claim 1.