WO2019208518A1

WO2019208518A1 - Optical filter and composition for optical filter

Info

Publication number: WO2019208518A1
Application number: PCT/JP2019/017086
Authority: WO
Inventors: 雄一郎久保; 雷蔡; 新毛　勝秀; 一瞳増田
Original assignee: 日本板硝子株式会社
Priority date: 2018-04-27
Filing date: 2019-04-22
Publication date: 2019-10-31
Also published as: JP6646179B2; JPWO2019208518A1; JP6783966B2; TW202001301A; JP2020024446A; JP6606626B1; JP2020024447A; TWI791823B; JP2020112826A; JP6686222B2; TW202323871A

Abstract

An optical filter (1a) is provided with a UV-IR absorption layer (10), and has a haze of 5% or less. The UV-IR absorption layer (10) includes a UV-IR absorbing agent capable of absorbing ultraviolet rays and infrared rays, formed by copper ions and phosphonic acid and/or sulfonic acid. A high-quality image can thereby be obtained by an imaging device in which the optical filter (1a) is incorporated, for example.

Description

Optical filter and optical filter composition

The present invention relates to an optical filter and a composition for an optical filter.

In an imaging device using a solid-state image sensor such as CCD (Charge-Coupled Device) or CMOS (Complementary Metal-Oxide-Semiconductor), various optical filters are placed on the front of the solid-state image sensor to obtain an image with good color reproducibility. Has been. In general, a solid-state imaging device has spectral sensitivity in a wide wavelength range from an ultraviolet region to an infrared region. On the other hand, human visibility exists only in the visible light region. For this reason, a technique is known in which an optical filter that shields infrared rays or ultraviolet rays is disposed in front of the solid-state image sensor in order to bring the spectral sensitivity of the solid-state image sensor in the image pickup apparatus closer to human visibility.

For example, Patent Document 1 includes a UV-IR absorption layer capable of absorbing infrared rays and ultraviolet rays, and exhibits predetermined transmission characteristics when light having a wavelength of 300 nm to 1200 nm is incident at incidence angles of 0 ° and 40 °. An optical filter is described. The UV-IR absorption layer of this optical filter contains a UV-IR absorber formed by phosphonic acid and copper ions.

Japanese Patent No. 6232161

The optical filter described in Patent Document 1 has desired characteristics with respect to transmittance, but Patent Document 1 does not discuss any haze of the optical filter. Accordingly, the present invention provides an optical filter having a desired haze while including a UV-IR absorber formed by at least one acid of phosphonic acid and sulfonic acid and copper ions. The present invention also provides an optical filter composition that is advantageous for producing the optical filter.

The present invention
Comprising a UV-IR absorber layer comprising a UV-IR absorber capable of absorbing ultraviolet and infrared rays formed by at least one acid of phosphonic acid and sulfonic acid and copper ions;
Having a haze of 5% or less,
An optical filter is provided.

The present invention also provides:
An optical filter composition comprising:
Including at least one acid of phosphonic acid and sulfonic acid, and copper ion,
When the coating film of the optical filter composition is cured to form a layer having a thickness of 100 to 300 μm, the layer can absorb ultraviolet rays and infrared rays, and the haze of the layer is 5% or less. is there,
A composition is provided.

The above optical filter has a haze of 5% or less while containing a UV-IR absorber formed by at least one acid of phosphonic acid and sulfonic acid and copper ions. In addition, the above composition is advantageous for producing such an optical filter.

FIG. 1A is a cross-sectional view showing an example of the optical filter of the present invention. FIG. 1B is a cross-sectional view showing another example of the optical filter of the present invention. FIG. 1C is a cross-sectional view showing still another example of the optical filter of the present invention. FIG. 1D is a cross-sectional view showing still another example of the optical filter of the present invention. FIG. 1E is a cross-sectional view showing still another example of the optical filter of the present invention. FIG. 1F is a cross-sectional view showing still another example of the optical filter of the present invention. FIG. 2 is a cross-sectional view showing an example of a camera module provided with the optical filter of the present invention. FIG. 3 is a transmittance spectrum of the optical filter according to the first embodiment. FIG. 4 is a transmittance spectrum of the optical filter according to the fourth embodiment. FIG. 5 is a transmittance spectrum of the optical filter according to Example 13. FIG. 6 is a transmittance spectrum of the optical filter according to Example 14. FIG. 7 is a transmittance spectrum of the optical filter according to Example 15. FIG. 8 is a transmittance spectrum of the optical filter according to Comparative Example 1.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description relates to an example of the present invention, and the present invention is not limited to these.

As described in Patent Document 1, an optical filter including a UV-IR absorption layer containing a UV-IR absorber formed of phosphonic acid and copper ions may have desired characteristics with respect to transmittance. On the other hand, the present inventors newly found that an optical filter having a UV-IR absorption layer containing a UV-IR absorber formed by phosphonic acid and copper ions does not necessarily have a desirable haze. It was. The haze corresponds to a percentage of the diffuse transmittance with respect to the total light transmittance. For example, in the Japanese Industrial Standard (JIS) K 7136: 2000, the haze is 0. It is defined as the percentage of transmitted light deviating by 044 rad (2.5 °) or more. In this specification, the definition of haze is in accordance with JIS K7136: 2000, and haze is measured in accordance with JIS K7136: 2000.

If the optical filter has desirable characteristics in terms of transmittance but has high haze, disposing the optical filter in front of the solid-state image sensor of the imaging device may reduce the image quality of the image obtained by the imaging device. . For example, problems such as uneven color, blurring, flare, and lightness may occur in an image. Therefore, the present inventors have studied day and night on a technique for keeping the haze low in an optical filter including a UV-IR absorption layer containing a UV-IR absorber formed of phosphonic acid and copper ions. As a result, the present inventors have a possibility that the dispersion state of the UV-IR absorber formed by phosphonic acid and copper ions in the composition for producing an optical filter may affect the haze of the optical filter. I found something new. Even if the dispersion state of the UV-IR absorber formed by phosphonic acid and copper ions is appropriate from the viewpoint of realizing a desired transmittance in the optical filter, this dispersion state is advantageous for realizing a low haze. It was newly discovered that there is no limit. Furthermore, based on this newly discovered knowledge, it was newly discovered that the dispersion state of the UV-IR absorber formed by sulfonic acid and copper ions may affect the haze of the optical filter. It was. Therefore, the present inventors have devised an optical filter having a low haze by repeating a great deal of trial and error.

As shown in FIG. 1A, the optical filter 1 a includes a UV-IR absorption layer 10. The UV-IR absorption layer 10 includes a UV-IR absorber capable of absorbing ultraviolet rays and infrared rays formed by at least one acid of phosphonic acid and sulfonic acid and copper ions. The optical filter 1a has a haze of 5% or less. For this reason, a high-quality image can be obtained by an imaging device incorporating the optical filter 1a.

The optical filter 1a desirably has a haze of 4% or less. Thereby, a high-quality image can be obtained more reliably by the imaging device in which the optical filter 1a is incorporated. The optical filter 1a desirably has a haze of 1% or less. Thereby, a higher quality image can be obtained by the imaging device in which the optical filter 1a is incorporated.

The optical filter 1a desirably exhibits the following optical performances (i) to (iv) when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °. When the optical filter 1a exhibits the following optical performance together with a haze of 5% or less, a high-quality image can be obtained in an imaging device incorporating the optical filter 1a.
(I) Average transmittance of 78% or more at wavelengths of 450 nm to 600 nm (ii) Spectral transmittance of 1% or less at wavelengths of 300 nm to 350 nm (iii) Spectral transmittance and wavelength that decrease with increasing wavelength at wavelengths of 600 nm to 750 nm First IR cutoff wavelength (iv) existing in the range of 610 nm to 680 nm (iv) Spectral transmittance increasing with increasing wavelength at a wavelength of 350 nm to 450 nm, and first UV cutoff wavelength existing in the range of 380 nm to 430 nm

In this specification, “spectral transmittance” is transmittance when incident light of a specific wavelength is incident on an object such as a sample, and “average transmittance” is spectral transmittance within a predetermined wavelength range. Further, in this specification, the “transmittance spectrum” is obtained by arranging spectral transmittances at respective wavelengths within a predetermined wavelength range in order of wavelength.

In this specification, “IR cutoff wavelength” indicates a spectral transmittance of 50% in a wavelength range of 600 nm or more when light having a wavelength of 300 nm to 1200 nm is incident on an optical filter at a predetermined incident angle. It means wavelength. The “first IR cutoff wavelength” is an IR cutoff wavelength when light is incident on the optical filter at an incident angle of 0 °. The “UV cut-off wavelength” is a wavelength showing a spectral transmittance of 50% in a wavelength range of 450 nm or less when light having a wavelength of 300 nm to 1200 nm is incident on the optical filter at a predetermined incident angle. means. The “first UV cutoff wavelength” is a UV cutoff wavelength when light is incident on the optical filter at an incident angle of 0 °.

Since the optical filter 1a exhibits the optical performances (i) to (iv) described above, the optical filter 1a has a large amount of transmitted light having a wavelength of 450 nm to 600 nm, and light having a wavelength of 300 nm to 400 nm and a wavelength of 650 nm or more. Can be cut effectively. For this reason, the transmittance spectrum of the optical filter 1a is suitable for human visibility. Moreover, even if the optical filter 1a is not provided with a layer other than the UV-IR absorption layer 10, the optical performances (i) to (iv) described above can be exhibited, and a haze of 5% or less can be realized.

Regarding (i) above, the optical filter 1a preferably has an average transmittance of 80% or more, more preferably 82% or more, at a wavelength of 450 nm to 600 nm.

Regarding (ii) above, the optical filter 1a desirably has a spectral transmittance of 0.5% or less at a wavelength of 300 nm to 350 nm. Thereby, the optical filter 1a can cut light in the ultraviolet region more effectively.

Regarding the above (iii), the first IR cutoff wavelength (wavelength exhibiting a spectral transmittance of 50%) is preferably present in the wavelength range of 610 nm to 660 nm, and more preferably in the wavelength range of 610 nm to 650 nm. Exists. Thereby, the transmittance spectrum of the optical filter 1a is more suitable for human visibility.

Regarding the above (iv), the first UV cutoff wavelength (wavelength exhibiting a spectral transmittance of 50%) is preferably present in the wavelength range of 390 nm to 430 nm, and more preferably in the wavelength range of 400 nm to 425 nm. Exists. Thereby, the transmittance spectrum of the optical filter 1a is more suitable for human visibility.

The optical filter 1a desirably exhibits the following optical performance (v) when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °. Thereby, the optical filter 1a can cut the light of a near infrared region effectively.
(V) Spectral transmittance of 5% or less at wavelengths of 750 nm to 1080 nm

The optical filter 1a desirably exhibits the following optical performance (vi) when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °. Thereby, infrared rays having a relatively long wavelength (wavelength 1000 to 1100 nm) can be cut. Conventionally, in order to cut light of this wavelength, a light reflecting film made of a dielectric multilayer film is often used. However, according to the optical filter 1a, light having this wavelength can be effectively cut without using such a dielectric multilayer film. Even if a light reflecting film composed of a dielectric multilayer film is required, the level of reflection performance required for the light reflecting film can be lowered, so the number of dielectric layers in the light reflecting film can be reduced, and the light reflecting film The cost required for formation can be reduced.
(Vi) Spectral transmittance of 10% or less at a wavelength of 1000 to 1100 nm

The optical filter 1a desirably exhibits the following optical performance (vii) when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °. In this case, infrared rays having a wavelength of 1100 to 1200 nm can be cut. As a result, the optical filter 1a can effectively cut light of this wavelength without using a dielectric multilayer film or even when the number of dielectric layers in the dielectric multilayer film is small.
(Vii) Spectral transmittance of 15% or less at a wavelength of 1100 to 1200 nm

The phosphonic acid that forms the UV-IR absorber in the UV-IR absorption layer 10 includes, for example, a first phosphonic acid having an aryl group. As a result, the optical filter 1a easily exhibits the optical characteristics (i) to (iv).

The aryl group of the first phosphonic acid is, for example, a phenyl group, a benzyl group, a toluyl group, a nitrophenyl group, a hydroxyphenyl group, a halogenated phenyl group in which at least one hydrogen atom in the phenyl group is substituted with a halogen atom, Alternatively, it is a halogenated benzyl group in which at least one hydrogen atom in the benzyl group is substituted with a halogen atom. Desirably, the first phosphonic acid has, in part, a halogenated phenyl group. In this case, the optical filter 1a can more reliably exhibit the optical performances (i) to (iv).

The phosphonic acid that forms the UV-IR absorber in the UV-IR absorption layer 10 desirably further includes a second phosphonic acid having an alkyl group. In the second phosphonic acid, the alkyl group is bonded to the phosphorus atom. The alkyl group of the second phosphonic acid may be an aromatic alkyl group. For example, a phenylmethyl group, a phenylethyl group, a phenylpropyl group, a phenylbutyl group, a phenylheptyl group, and a phenylhexyl group can be exemplified. The aromatic alkyl group may be a halogenated aromatic alkyl group. The halogenated aromatic alkyl group is, for example, a halogenated phenylalkyl group in which at least one hydrogen atom in the phenyl group is substituted with a halogen atom.

The alkyl group possessed by the second phosphonic acid is, for example, an alkyl group having 6 or less carbon atoms. This alkyl group may have either a straight chain or a branched chain. As described above, the alkyl group of the second phosphonic acid may have an aromatic substituent or a halogenated aromatic substituent.

The sulfonic acid that forms the UV-IR absorber in the UV-IR absorption layer 10 includes, for example, a first sulfonic acid having an aryl group. As a result, the optical filter 1a easily exhibits the optical characteristics (i) to (iv). The aryl group of the first sulfonic acid is, for example, a phenyl group, a benzyl group, a toluyl group, a nitrophenyl group, a hydroxyphenyl group, or a halogenated phenyl group in which at least one hydrogen atom in the phenyl group is substituted with a halogen atom. . Alternatively, it is a halogenated benzyl group in which at least one hydrogen atom in the benzyl group is substituted with a halogen atom. The primary sulfonic acid can be benzenesulfonic acid, p-toluenesulfonic acid, 4-bromobenzenesulfonic acid, 4-methylbenzylsulfonic acid, or 4-bromobenzylsulfonic acid.

The sulfonic acid that forms the UV-IR absorber in the UV-IR absorption layer 10 desirably further includes a second sulfonic acid having an alkyl group. The second sulfonic acid is, for example, a sulfonic acid having a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, or a hexyl group. The alkyl group of the second sulfonic acid may have an aromatic substituent.

The UV-IR absorption layer 10 preferably further includes a phosphate ester in which the UV-IR absorber is dispersed and a matrix resin.

The phosphate ester contained in the UV-IR absorption layer 10 is not particularly limited as long as the UV-IR absorber can be appropriately dispersed. For example, the phosphate diester represented by the following formula (c1) and the following formula ( at least one of phosphoric acid monoesters represented by c2). In the following formula (c1) and the following formula (c2), R ₂₁ , R ₂₂ , and R ₃ are each a monovalent functional group represented by — (CH ₂ CH ₂ O) _n R ₄ , n Is an integer of 1 to 25, and R ₄ represents an alkyl group having 6 to 25 carbon atoms. R ₂₁ , R ₂₂ , and R ₃ are the same or different types of functional groups.

The phosphate ester is not particularly limited. For example, Plysurf A208N: polyoxyethylene alkyl (C12, C13) ether phosphate ester, Plysurf A208F: polyoxyethylene alkyl (C8) ether phosphate ester, Plysurf A208B: Polyoxyethylene lauryl ether phosphate ester, plysurf A219B: polyoxyethylene lauryl ether phosphate ester, plysurf AL: polyoxyethylene styrenated phenyl ether phosphate ester, plysurf A212C: polyoxyethylene tridecyl ether phosphate ester Or Plysurf A215C: Polyoxyethylene tridecyl ether phosphate. These are all products manufactured by Daiichi Kogyo Seiyaku. Also, the phosphoric acid ester is NIKKOL DDP-2: polyoxyethylene alkyl ether phosphate ester, NIKKOL DDP-4: polyoxyethylene alkyl ether phosphate ester, or NIKKOL DDP-6: polyoxyethylene alkyl ether phosphate ester. possible. These are all products manufactured by Nikko Chemicals.

The matrix resin included in the UV-IR absorption layer 10 is, for example, a resin that can disperse a UV-IR absorber and can be cured by heat or ultraviolet light. Furthermore, when a resin layer having a thickness of 0.1 mm is formed from the resin as the matrix resin, the transmittance of the resin layer with respect to a wavelength of 350 nm to 900 nm is, for example, 70% or more, desirably 75% or more, and more desirably. May be a resin that is 80% or more. The content of at least one of phosphonic acid and sulfonic acid is, for example, 5 to 400 parts by mass with respect to 100 parts by mass of the matrix resin.

The matrix resin contained in the UV-IR absorption layer 10 is not particularly limited as long as the above properties are satisfied. For example, (poly) olefin resin, polyimide resin, polyvinyl butyral resin, polycarbonate resin, polyamide resin, polysulfone resin, polyether Sulphone resin, polyamideimide resin, (modified) acrylic resin, epoxy resin, or silicone resin. The matrix resin may contain an aryl group such as a phenyl group, and is preferably a silicone resin containing an aryl group such as a phenyl group. If the UV-IR absorption layer 10 is hard (rigid), as the thickness of the UV-IR absorption layer 10 increases, cracks tend to occur due to curing shrinkage during the manufacturing process of the optical filter 1a. When the matrix resin is a silicone resin containing an aryl group, the UV-IR absorption layer 10 tends to have good crack resistance. In addition, when a silicone resin containing an aryl group is used, the UV-IR absorber formed by at least one acid of phosphonic acid and sulfonic acid and a copper ion hardly aggregates. Further, when the matrix resin of the UV-IR absorption layer 10 is a silicone resin containing an aryl group, the phosphoric acid ester contained in the UV-IR absorption layer 10 is a phosphorus represented by the formula (c1) or the formula (c2). It is desirable to have a linear organic functional group having flexibility such as an oxyalkyl group such as an acid ester. Because of the interaction based on the combination of at least one of the above-mentioned phosphonic acid and sulfonic acid, a silicone resin containing an aryl group, and a phosphate ester having a linear organic functional group such as an oxyalkyl group, UV- This is because the IR absorber hardly aggregates and can provide the UV-IR absorption layer 10 with good rigidity and good flexibility. Specific examples of the silicone resin used as the matrix resin include KR-255, KR-300, KR-2621-1, KR-211, KR-311, KR-216, KR-212, and KR-251. be able to. These are all silicone resins manufactured by Shin-Etsu Chemical Co., Ltd.

The optical filter 1a further includes a hydrolysis-condensation product of an alkoxysilane monomer as necessary. When the optical filter 1a contains a hydrolysis-condensation product of an alkoxysilane monomer, the optical filter 1a has good moisture resistance due to the siloxane bond (—Si—O—Si—) of the hydrolysis-condensation product of the alkoxysilane monomer. . In addition, the optical filter 1a has good heat resistance. This is because a siloxane bond has a higher bond energy and is chemically stable than bonds such as a —C—C— bond and a —C—O— bond, and is excellent in heat resistance and moisture resistance.

The UV-IR absorption layer 10 in the optical filter 1a can be formed by curing a coating film of a predetermined optical filter composition.

The composition for an optical filter contains at least one acid of phosphonic acid and sulfonic acid and copper ions. In addition, the optical filter composition can absorb ultraviolet rays and infrared rays when the coating film of the composition is cured to form a layer having a thickness of 100 to 300 μm. The haze is 5% or less (preferably 4% or less). It should be noted that such a characteristic should appear when the cured layer of the optical filter composition has a specific thickness within the range of 100 to 300 μm. That is, the cured product layer of the optical filter composition need not satisfy such characteristics in the entire range of 100 to 300 μm.

In the optical filter composition, desirably, the coating film of the composition is cured to form a layer having a thickness of 100 to 300 μm, and light having a wavelength of 300 nm to 1200 nm is incident on this layer at an incident angle of 0 °. When prepared, the following conditions (I) to (IV) are satisfied.
(I) It has an average transmittance of 78% or more at a wavelength of 450 nm to 600 nm.
(II) It has a spectral transmittance of 1% or less at a wavelength of 300 nm to 350 nm.
(III) The first IR cutoff wavelength having a spectral transmittance that decreases with an increase in wavelength at a wavelength of 600 nm to 750 nm and a spectral transmittance of 50% at a wavelength of 600 nm to 750 nm is within the wavelength range of 610 nm to 680 nm. Exists.
(IV) The first UV cut-off wavelength having a spectral transmittance that increases with an increase in wavelength at a wavelength of 350 nm to 450 nm and a spectral transmittance of 50% at a wavelength of 350 nm to 450 nm is in the range of a wavelength of 380 nm to 430 nm. Exists.

The optical filter composition has a viscosity of 1 to 200 mPa · s at 22 to 23 ° C., for example. In this case, the composition for optical filters tends to flow, and seems to be disadvantageous for forming a coating film with the composition for optical filters. In addition, in order to adjust the viscosity of the optical filter composition to such a range, it is necessary to add a relatively large amount of solvent (dispersion medium), and a process for curing the coating film of the optical filter composition is required. May be longer. Therefore, until now, it is desirable for the present inventors to prepare the optical filter composition so that the viscosity at 22 to 23 ° C. exceeds the viscosity of 200 mPa · s (for example, 300 mPa · s or more). I was thinking. On the other hand, the present inventors drastically reviewed the viscosity of the optical filter composition from the viewpoint of reducing the haze of the UV-IR absorption layer obtained by curing the coating film of the optical filter composition. As a result, it was newly found out that it is desirable to adjust the viscosity at 22 to 23 ° C. of the optical filter composition to 1 to 200 mPa · s from the viewpoint of reducing the haze of the UV-IR absorption layer. Even when the above-mentioned UV-IR absorber is aggregated to such an extent that it does not affect the transmittance characteristics of the UV-IR absorption layer in the optical filter composition, the state of aggregation in the coating film of the optical filter composition is It is considered that the haze of the UV-IR absorption layer tends to be high unless properly eliminated. On the other hand, when the optical filter composition has a viscosity of 1 to 200 mPa · s at 22 to 23 ° C., the optical filter composition flows appropriately in the coating film of the optical filter composition, and the UV-IR absorber It is thought that the aggregated state of is easy to be eliminated. As a result, it is considered that the haze of the UV-IR absorption layer can be reduced. When the viscosity at 22 to 23 ° C. of the optical filter composition is less than 1 mPa · s, the amount of the solvent in the optical filter composition is too large, and the physical distance of the components forming the UV-IR absorption layer is small. growing. For this reason, a UV-IR absorption layer may not be formed appropriately.

The viscosity of the optical filter composition at 22 to 23 ° C. can be measured using, for example, a vibration viscometer (probe: PR-10 L, controller: VM-10A) manufactured by Seconic.

The optical filter composition desirably has a viscosity of 2 to 180 mPa · s at 22 to 23 ° C., and more desirably has a viscosity of 2 to 160 mPa · s at 22 to 23 ° C. Thereby, the haze of the UV-IR absorption layer obtained by curing the coating film of this composition can be more reliably reduced to 5% or less.

In the optical filter composition, the solid content is, for example, 3 to 17% by mass. In this case, it is considered that the content of solids is relatively small, the optical filter composition easily flows appropriately in the coating film of the optical filter composition, and the haze of the UV-IR absorbing layer is easily reduced.

In the optical filter composition, the solid content is desirably 5 to 17% by mass, and more desirably 6 to 17% by mass.

In the optical filter composition, the copper ion content is, for example, 0.5 to 2.2% by mass. In this case, the content of copper ions in the composition is relatively small, aggregation of the UV-IR absorber is unlikely to occur in the coating film of the optical filter composition, and the haze of the UV-IR absorption layer is likely to be reduced. It is done.

In the optical filter composition, the copper ion content is desirably 0.6 to 2.1% by mass.

The composition for an optical filter includes a component contained in the UV-IR absorption layer 10 or a precursor of the component. The optical filter composition further includes, for example, a predetermined solvent (dispersion medium). The composition for optical filters may contain, for example, an alkoxysilane monomer. When the optical filter composition contains an alkoxysilane monomer, it is possible to suppress the aggregation of the UV-IR absorber particles in the optical filter composition, and even if the phosphate ester content is reduced, the optical filter composition The UV-IR absorber is well dispersed in the filter composition.

An example of a method for manufacturing the optical filter 1a will be described. First, an example of the preparation method of the composition for optical filters is demonstrated. A copper salt such as copper acetate monohydrate is added to a predetermined solvent such as tetrahydrofuran (THF) and stirred to obtain a copper salt solution. Next, a phosphoric acid ester compound such as a phosphoric acid diester represented by the formula (c1) or a phosphoric acid monoester represented by the formula (c2) is added to the solution of the copper salt and stirred to prepare a solution A. To do. Also, the first phosphonic acid or the first sulfonic acid is added to a predetermined solvent such as THF and stirred to prepare the liquid B. When using a plurality of types of phosphonic acid or sulfonic acid as the first phosphonic acid or the first sulfonic acid, the first phosphonic acid or the first sulfonic acid is added to a predetermined solvent such as THF and stirred to obtain the first phosphonic acid. A plurality of preliminary solutions prepared for each type of acid or primary sulfonic acid may be mixed to prepare solution B. An alkoxysilane monomer may be added in the preparation of the liquid B.

Next, while stirring the liquid A, the liquid B is added to the liquid A and stirred for a predetermined time. Next, a predetermined solvent such as toluene is added to this solution and stirred to obtain liquid C. Next, desolvation treatment is performed for a predetermined time while heating the C liquid to obtain the D liquid. This removes components generated by dissociation of a solvent such as THF and a copper salt such as acetic acid (boiling point: about 118 ° C.), and the UV-IR absorber is absorbed by the first phosphonic acid or first sulfonic acid and copper ions. Generated. The temperature at which the liquid C is heated is determined based on the boiling point of the component to be removed that has dissociated from the copper salt. In the solvent removal treatment, the solvent such as toluene (boiling point: about 110 ° C.) used to obtain the liquid C also volatilizes, but the solvent remains in the liquid D so that the viscosity of the liquid D is in a desired range. To do. The addition amount of the solvent for obtaining the liquid C may be adjusted so that the viscosity of the liquid D is in a desired range, or the time for the solvent removal treatment may be adjusted.

When the optical filter composition further contains a second phosphonic acid or a second sulfonic acid, for example, a liquid H is further prepared as follows. First, a copper salt such as copper acetate monohydrate is added to a predetermined solvent such as tetrahydrofuran (THF) and stirred to obtain a copper salt solution. Next, a phosphoric acid ester compound such as a phosphoric acid diester represented by the formula (c1) or a phosphoric acid monoester represented by the formula (c2) is added to the solution of the copper salt and stirred to prepare a solution E. To do. Further, the second phosphonic acid or the second sulfonic acid is added to a predetermined solvent such as THF and stirred to prepare a solution F. When a plurality of types of phosphonic acid or sulfonic acid are used as the second phosphonic acid or the second sulfonic acid, the second phosphonic acid or the second sulfonic acid is added to a predetermined solvent such as THF and then stirred to add the second phosphonic acid. Alternatively, the F solution may be prepared by mixing a plurality of preliminary solutions prepared for each type of the second sulfonic acid. While stirring E liquid, F liquid is added to E liquid and stirred for a predetermined time. Next, a predetermined solvent such as toluene is added to this solution and stirred to obtain a solution G. Next, a solvent removal process is performed for a predetermined time while the G solution is heated to obtain the H solution. Thereby, components generated by dissociation of a solvent such as THF and a copper salt such as acetic acid are removed, and another UV-IR absorber is generated by the second phosphonic acid or the second sulfonic acid and the copper ion. The temperature for heating the G liquid is determined in the same manner as in the C liquid, and the solvent for obtaining the G liquid is also determined in the same manner as in the C liquid. The addition amount of the solvent for obtaining the G liquid is not particularly limited.

The composition for optical filters can be prepared by adding a matrix resin such as silicone resin to D solution and stirring. In addition, when the optical filter composition contains a UV-IR absorber formed by the second phosphonic acid or second sulfonic acid and copper ions, a matrix resin such as a silicone resin is added to the liquid D and stirred. The composition for optical filters can be prepared by further adding the H liquid to the I liquid obtained in this manner and stirring.

Next, the optical filter composition is applied to one main surface of a predetermined substrate to form a coating film. The substrate is not particularly limited, and a glass substrate, a resin substrate, or a metal substrate (steel substrate or stainless steel substrate) can be used. For example, a liquid optical filter composition is applied to one main surface of the substrate by spin coating, die coating, or application by a dispenser to form a coating film. Next, the coating film is cured by performing a predetermined heat treatment on the coating film. For example, the coating film is exposed to an environment having a temperature of 40 ° C. to 200 ° C. If necessary, the coating film is humidified in order to sufficiently hydrolyze and polycondensate the alkoxysilane monomer contained in the optical filter composition. For example, the cured coating film is exposed to an environment having a temperature of 40 ° C. to 100 ° C. and a relative humidity of 40% to 100%. As a result, a repeating structure of siloxane bonds (Si—O) _n is formed. In general, in the hydrolysis and polycondensation reaction of an alkoxysilane containing a monomer, the alkoxysilane and water may coexist in the liquid composition to cause these reactions. However, if water is added to the optical filter composition in advance when manufacturing the optical filter, the phosphate ester or the UV-IR absorber deteriorates in the process of forming the UV-IR absorption layer, and UV -IR absorption performance may be degraded, and the durability of the optical filter may be impaired. For this reason, it is desirable to perform a humidification process after hardening a coating film by predetermined | prescribed heat processing. In this way, the UV-IR absorption layer 10 can be formed on the substrate. Then, the optical filter 1a is obtained by peeling the UV-IR absorption layer 10 from the substrate. The optical filter 1a has a simple configuration and is easily reduced in thickness. For this reason, the optical filter 1a can contribute to the low profile of the imaging device and the optical system.

As described above, the optical filter composition has a relatively low viscosity of, for example, a viscosity of 1 to 200 mPa · s at 22 to 23 ° C. In this case, the optical filter composition contains a relatively large amount of solvent. For this reason, when the coating film of the composition for optical filters is cured by heating, if the coating film is heated at a high temperature from the beginning, the UV-IR absorption layer is likely to crack due to rapid volatilization of the solvent. For this reason, after heating the coating film of the optical filter composition for a predetermined time in a relatively low temperature environment of 60 ° C. or less, the coating film can be heated for a predetermined time in a relatively high temperature environment having a temperature exceeding 60 ° C. desirable. It is possible to prevent the solvent from volatilizing slowly and bond due to the polycondensation reaction of the alkoxysilane monomer or silicone resin to proceed in parallel, thereby preventing the UV-IR absorption layer from cracking. As a result, an optical filter having desired transmittance characteristics and low haze can be stably produced. The coating film of the optical filter composition is desirably heated in an environment of 60 ° C. or lower for 10 minutes or more, and then exposed to an environment exceeding 60 ° C. More preferably, the coating film of the optical filter composition is exposed to an environment exceeding 60 ° C. after being heated for 20 minutes or more in an environment of 45 ° C. or less.

<Modification>
The optical filter 1a can be changed from various viewpoints. For example, the optical filter 1a may be changed to the optical filters 1b to 1f shown in FIGS. 1B to 1F, respectively. The optical filters 1b to 1f are configured in the same manner as the optical filter 1a unless otherwise described. Constituent elements of the optical filters 1b to 1f that are the same as or correspond to the constituent elements of the optical filter 1a are assigned the same reference numerals, and detailed descriptions thereof are omitted. The description regarding the optical filter 1a also applies to the optical filters 1b to 1f unless there is a technical contradiction.

As shown in FIG. 1B, an optical filter 1b according to another example of the present invention includes a UV-IR absorption layer 10 and a pair of antireflection films 30 disposed on both surfaces thereof. The antireflection film 30 is a film that is formed so as to form an interface between the optical filter 1b and air and reduces reflection of light in the visible light region. The antireflection film 30 is a film formed of a dielectric material such as resin, oxide, and fluoride. The antireflection film 30 may be a multilayer film formed by laminating two or more kinds of dielectrics having different refractive indexes. In particular, the antireflection film 30 may be a dielectric multilayer film made of a low refractive index material such as SiO ₂ and a high refractive index material such as TiO ₂ or Ta ₂ O ₅ . In this case, Fresnel reflection at the interface between the optical filter 1b and air is reduced, and the amount of light in the visible light region of the optical filter 1b can be increased. In order to improve the adhesion of the antireflection film 30, a resin layer containing a silane coupling agent may be formed between the UV-IR absorption layer 10 and the antireflection film 30. The antireflection film 30 may be disposed on both main surfaces of the UV-IR absorption layer 10 or may be disposed only on one main surface. The optical filter 1b can contribute to lowering the height of the imaging device and the optical system, and can increase the amount of light in the visible light region as compared to the optical filter 1a.

As shown in FIG. 1C, an optical filter 1c according to another example of the present invention includes a UV-IR absorption layer 10 and a reflective film 40 that reflects infrared rays and / or ultraviolet rays disposed on one main surface thereof. I have. The reflective film 40 is, for example, a film formed by vapor deposition of a metal such as aluminum, or a dielectric multilayer film in which layers made of a high refractive index material and layers made of a low refractive index material are alternately laminated. is there. As the high refractive index material, a material having a refractive index of 1.7 to 2.5 such as TiO ₂ , ZrO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ , ZnO, and In ₂ O ₃ is used. As the low refractive index material, a material having a refractive index of 1.2 to 1.6 such as SiO ₂ , Al ₂ O ₃ , and MgF ₂ is used. A method for forming the dielectric multilayer film is, for example, a chemical vapor deposition (CVD) method, a sputtering method, or a vacuum evaporation method. Further, such a reflective film may be formed so as to form both main surfaces of the optical filter (not shown). When reflective films are formed on both main surfaces of the optical filter, the stress is balanced on both the front and back surfaces of the optical filter, so that the optical filter is less likely to warp.

As shown in FIG. 1D, an optical filter 1d according to another example of the present invention includes a transparent dielectric substrate 20 and a UV-IR absorption layer 10 formed on one main surface of the transparent dielectric substrate 20. ing. The transparent dielectric substrate 20 is not particularly limited as long as it is a dielectric substrate having a high average transmittance (for example, 80% or more) at 450 nm to 600 nm. In some cases, the transparent dielectric substrate 20 may have an absorptivity in the ultraviolet region or the infrared region.

The transparent dielectric substrate 20 is made of, for example, glass or resin. When the transparent dielectric substrate 20 is made of glass, the glass contains, for example, borosilicate glass such as D263 T eco, soda lime glass (blue plate), white plate glass such as B270, non-alkali glass, or copper. Infrared absorbing glass such as phosphate glass or fluorophosphate glass containing copper. When the transparent dielectric substrate 20 is an infrared absorbing glass such as a phosphate glass containing copper or a fluorophosphate glass containing copper, the infrared absorbing performance and UV of the transparent dielectric substrate 20 are included. -The infrared absorption performance required for the optical filter 1d can be realized by the combination with the infrared absorption performance of the IR absorption layer 10. For this reason, the level of infrared absorption performance required for the UV-IR absorption layer 10 can be lowered. Such infrared-absorbing glass is, for example, BG-60, BG-61, BG-62, BG-63, or BG-67 manufactured by Schott, 500EXL manufactured by Nippon Electric Glass, or HOYA. CM5000, CM500, C5000, or C500S manufactured by the company. Further, the infrared absorbing glass may have an ultraviolet absorbing property.

The transparent dielectric substrate 20 may be a crystalline substrate having transparency such as magnesium oxide, sapphire, or quartz. For example, since sapphire has high hardness, it is hard to be damaged. For this reason, the plate-like sapphire may be disposed as a scratch-resistant protective material (protect filter) in front of a camera module or a lens provided in a mobile terminal such as a smartphone or a mobile phone. By forming the UV-IR absorption layer 10 on such plate-like sapphire, it is possible to shield ultraviolet rays or infrared rays as well as protecting the camera module and the lens. This eliminates the need to arrange an optical filter having ultraviolet or infrared shielding properties around a solid-state imaging device such as a CCD or CMOS or inside a camera module. For this reason, if the UV-IR absorption layer 10 is formed on the plate-like sapphire, it can contribute to the low profile of the camera module.

When the transparent dielectric substrate 20 is made of a resin, the resin is, for example, (poly) olefin resin, polyimide resin, polyvinyl butyral resin, polycarbonate resin, polyamide resin, polysulfone resin, polyethersulfone resin, polyamideimide resin. (Modified) acrylic resin, epoxy resin, or silicone resin.

When the transparent dielectric substrate 20 is a glass substrate, in order to improve the adhesion between the transparent dielectric substrate 20 and the UV-IR absorption layer 10, a resin layer containing a silane coupling agent is applied to the transparent dielectric substrate 20 and the UV. -You may form between IR absorption layers 10.

As shown in FIG. 1E, an optical filter 1e according to another example of the present invention has UV-IR absorption layers 10 formed on both main surfaces of a transparent dielectric substrate 20. Thereby, the optical filter 1e can exhibit the optical performances (i) to (iv) described above not by the single UV-IR absorption layer 10 but by the two UV-IR absorption layers 10. The thickness of the UV-IR absorption layer 10 on both main surfaces of the transparent dielectric substrate 20 may be the same or different. That is, the UV-IR absorption layer 10 necessary for the optical filter 1e to obtain desired optical characteristics is uniformly or non-uniformly distributed on both main surfaces of the transparent dielectric substrate 20 with UV. -IR absorption layer 10 is formed. Thereby, the thickness of each UV-IR absorption layer 10 formed on both main surfaces of the transparent dielectric substrate 20 is relatively small. As a result, the internal pressure of the coating film is low and the occurrence of cracks can be prevented. Moreover, the time for applying the liquid optical filter composition can be shortened, and the time for curing the coating film of the optical filter composition can be shortened. When the transparent dielectric substrate 20 is thin, when the UV-IR absorption layer 10 is formed only on one main surface of the transparent dielectric substrate 20, this occurs when the UV-IR absorption layer 10 is formed from the optical filter composition. The optical filter may be warped due to the stress accompanying the shrinkage. However, since the UV-IR absorption layer 10 is formed on both main surfaces of the transparent dielectric substrate 20, even when the transparent dielectric substrate 20 is thin, warping is suppressed in the optical filter 1e. Also in this case, in order to improve the adhesion between the transparent dielectric substrate 20 and the UV-IR absorption layer 10, a resin layer containing a silane coupling agent is interposed between the transparent dielectric substrate 20 and the UV-IR absorption layer 10. You may form in.

As shown in FIG. 1F, the optical filter 1 f according to another example of the present invention includes an antireflection film 30. The antireflection film 30 is formed so as to form an interface between the optical filter 1f and air. In the optical filter 1f, the antireflection film 30 is arranged on both main surfaces of the optical filter 1f, but may be arranged only on one main surface. In this case, the amount of light in the visible light region of the optical filter 1f can be increased.

Each of the optical filters 1a to 1f may be changed to include an infrared absorption film (not shown) separately from the UV-IR absorption layer 10 as necessary. The infrared absorbing film contains, for example, an organic infrared absorbing agent such as cyanine-based, phthalocyanine-based, squarylium-based, diimmonium-based, and azo-based or an infrared absorbing agent made of a metal complex. The infrared absorbing film contains, for example, one or more infrared absorbers selected from these infrared absorbers. This organic infrared absorber has a small wavelength range (absorption band) of light that can be absorbed, and is suitable for absorbing light in a specific range of wavelengths.

Each of the optical filters 1a to 1f may be changed to include an ultraviolet absorbing film (not shown) separately from the UV-IR absorbing layer 10 as necessary. The ultraviolet absorbing film contains, for example, an ultraviolet absorber such as benzophenone, triazine, indole, merocyanine, and oxazole. The ultraviolet absorbing film contains, for example, one or more ultraviolet absorbers selected from these ultraviolet absorbers. These ultraviolet absorbers include, for example, those that absorb ultraviolet rays in the vicinity of 300 nm to 340 nm, emit light having a wavelength longer than the absorbed wavelength (fluorescence), and function as a fluorescent agent or fluorescent whitening agent. The ultraviolet absorbing film can reduce the incidence of ultraviolet rays that cause deterioration of materials used for optical filters such as resins.

The above infrared absorber or ultraviolet absorber may be preliminarily contained in the transparent dielectric substrate 20 made of resin. The infrared absorbing film and the ultraviolet absorbing film can be formed, for example, by forming a resin containing an infrared absorbing agent or an ultraviolet absorbing agent. In this case, the resin needs to be able to appropriately dissolve or disperse the infrared absorber or the ultraviolet absorber and be transparent. Such resins include (poly) olefin resins, polyimide resins, polyvinyl butyral resins, polycarbonate resins, polyamide resins, polysulfone resins, polyethersulfone resins, polyamideimide resins, (modified) acrylic resins, epoxy resins, and silicone resins. Can be illustrated.

The optical filters 1a to 1f are arranged, for example, on the front surface (the side close to the subject) of a solid-state imaging device such as a CCD or CMOS inside the imaging device in order to bring the spectral sensitivity of the imaging device closer to human visibility.

Further, as shown in FIG. 2, for example, the camera module 100 using the optical filter 1d can be provided. In addition to the optical filter 1d, the camera module 100 includes, for example, a lens system 2, a low-pass filter 3, a solid-state imaging device 4, a circuit board 5, an optical filter support housing 7, and an optical system housing 8. The peripheral edge of the optical filter 1d is fitted in an annular recess that is in contact with an opening formed in the center of the optical filter support housing 7, for example. The optical filter support housing 7 is fixed to the optical system housing 8. Inside the optical system housing 8, the lens system 2, the low-pass filter 3, and the solid-state imaging device 4 are arranged in this order along the optical axis. The solid-state image sensor 4 is, for example, a CCD or a CMOS. The light from the subject is cut by ultraviolet and infrared rays by the optical filter 1 d, condensed by the lens system 2, and further passes through the low-pass filter 3 and enters the solid-state imaging device 4. The electrical signal generated by the solid-state imaging device 4 is sent to the outside of the camera module 100 by the circuit board 5.

In the camera module 100, the optical filter 1d also functions as a cover (protect filter) for protecting the lens system 2. In this case, a sapphire substrate is preferably used as the transparent dielectric substrate 20 in the optical filter 1d. Since the sapphire substrate has high scratch resistance, for example, it is desirable that the sapphire substrate is disposed on the outside (the side opposite to the solid-state imaging device 4 side). Thereby, the optical filter 1d has high scratch resistance against external contact and the like, absorbs ultraviolet rays and infrared rays, and has a low haze of 5% or less. The optical filter 1d desirably has the optical performances (i) to (iv) described above, and more desirably has the optical performances (v) to (vii). Thereby, it is not necessary to arrange an optical filter for cutting infrared rays or ultraviolet rays in the vicinity of the solid-state imaging device 4, and the camera module 100 can be easily lowered. Note that the camera module 100 shown in FIG. 2 is a schematic diagram for illustrating the arrangement and the like of each component, and describes an aspect in which the optical filter 1d is used as a protection filter. As long as the optical filter 1d functions as a protection filter, the camera module using the optical filter 1d is not limited to that shown in FIG. 2, and the low-pass filter 3 may be omitted if necessary. Other filters may be provided.

The present invention will be described in more detail by way of examples. The present invention is not limited to the following examples.

<Example 1>
Copper acetate monohydrate (4.500 g) and tetrahydrofuran (THF) (240 g) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 1.646 g of Prisurf A208N (Daiichi Kogyo Seiyaku Co., Ltd.), which is a phosphate ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain Liquid A. 40 g of THF was added to 0.706 g of phenylphosphonic acid and stirred for 30 minutes to obtain a solution B-1. 40 g of THF was added to 4.230 g of 4-bromophenylphosphonic acid and stirred for 30 minutes to obtain a liquid B-2. Next, the B-1 liquid and the B-2 liquid were mixed and stirred for 1 minute. 8.664 g of methyltriethoxysilane (MTES: manufactured by Shin-Etsu Chemical Co., Ltd.) and tetraethoxysilane (TEOS: special grade manufactured by Kishida Chemical Co., Ltd.) 2.840g was added to this liquid mixture, and also it stirred for 1 minute, and B liquid was obtained. Liquid B was added to liquid A while stirring liquid A, and the mixture was stirred at room temperature for 1 minute. Next, after adding 140 g of toluene to this solution, it stirred at room temperature for 1 minute, and obtained C liquid. The solution C was put into a flask and heated with an oil bath (Tokyo Rika Kikai Co., Ltd., model: OSB-2100), and the solvent was removed by a rotary evaporator (Tokyo Rika Kikai Co., Ltd., model: N-1110SF). went. The set temperature of the oil bath was adjusted to 105 ° C. Thereafter, the liquid D according to Example 1 after the solvent removal treatment was taken out from the flask. The solvent removal treatment was carried out so that the viscosity of the liquid D was lowered to some extent without completely removing the solvent in the solvent removal treatment. Liquid D, which is a dispersion of fine particles of phenyl-based copper phosphonate (UV-IR absorber), was transparent, and the fine particles were well dispersed in Liquid D. The obtained D liquid was 107.06g. Table 1 shows the amount of toluene added to obtain the D liquid, the mass of the obtained D liquid, and the concentration of copper ions in the D liquid.

Copper acetate monohydrate (4.500 g) and THF (240 g) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 2.572 g of PRISURF A208N, which is a phosphate ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain solution E. Further, 40 g of THF was added to 2.886 g of n-butylphosphonic acid, followed by stirring for 30 minutes to obtain a liquid F. While stirring E solution, F solution was added to E solution and stirred at room temperature for 1 minute. Next, 84 g of toluene was added to this solution, followed by stirring at room temperature for 1 minute to obtain solution G. The solvent G was put into a flask and heated with an oil bath, and the solvent was removed by a rotary evaporator. The set temperature of the oil bath was adjusted to 105 ° C. Thereafter, the liquid H according to Example 1 after the solvent removal treatment was taken out of the flask. The solvent removal treatment was performed so that the viscosity of the liquid H became a predetermined viscosity without completely removing the solvent in the solvent removal treatment. Liquid H, which is a dispersion of fine particles of copper butylphosphonate (UV-IR absorber), was transparent, and fine particles were well dispersed in the liquid H. The obtained liquid H was 68.12 g. Table 2 shows the amount of toluene added to obtain the H liquid, the mass of the obtained H liquid, and the concentration of copper ions in the H liquid.

10. Silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) was added to solution D and stirred for 30 minutes to obtain solution I. 27.25 g of liquid H corresponding to 40% by mass of the total amount of liquid H was added to liquid I and stirred for 30 minutes to obtain an optical filter composition according to Example 1. Table 3 shows the addition amounts of the D solution, the H solution, and the silicone resin in the optical filter composition according to Example 1.

Surface antifouling coating agent (Daikin Kogyo Co., Ltd., product name: OPTOOL DSX, active ingredient concentration: 20% by mass) 0.1 g and Novec 7100 (manufactured by 3M, ingredient: hydrofluoroether) 19.9 g were mixed. The mixture was stirred for 5 minutes to prepare a fluorination agent (active ingredient concentration: 0.1% by mass). This fluorination agent is applied to a transparent glass substrate (manufactured by SCHOTT, product name: D263 T eco) made of borosilicate glass having dimensions of 76 mm × 76 mm × 0.21 mm at a rotation speed of 3000 rpm (revolutions per minute). Spin coated. Thereafter, the transparent glass substrate was allowed to stand at room temperature for 24 hours to dry the coating film of the fluorine treatment agent, thereby obtaining a glass substrate subjected to fluorine treatment (easy peeling treatment).

Using the dispenser, the optical filter composition according to Example 1 was applied to form a coating film in a rectangular area having a center of about 30 mm × 30 mm on the main surface of the glass substrate subjected to fluorine treatment. A frame having a 30 mm × 30 mm square hole in the center and a thickness of 5 mm was attached to a glass substrate, and the optical filter composition according to Example 1 was applied to the inside of the frame. Next, the transparent glass substrate having an undried coating film was placed in an oven and subjected to a heat treatment at 45 ° C. for 2 hours and further at 85 ° C. for 6 hours to cure the coating film. Thereafter, a glass substrate having a coating film was placed in a constant temperature and humidity chamber set at a temperature of 85 ° C. and a relative humidity of 85% for 2 hours for humidification treatment. Thereafter, the layer formed by curing the coating film of the optical filter composition from the glass substrate was peeled off to produce an optical filter according to Example 1.

<Examples 2 to 15 and Comparative Example 1>
Except that the preparation conditions for the D solution were changed so that the amount of toluene added to obtain the D solution, the mass of the obtained D solution, and the concentration of copper ions in the D solution were as shown in Table 1. In the same manner as Example 1, D liquids according to Examples 2 to 15 and D liquid according to Comparative Example 1 were prepared. Except for changing the preparation conditions of the H liquid so that the amount of toluene added to obtain the H liquid, the mass of the obtained H liquid, and the concentration of copper ions in the H liquid are as shown in Table 2. In the same manner as in Example 1, solutions H according to Examples 2 to 15 and Comparative Example 1 were prepared. The compositions for optical filters according to Examples 2 to 15 and Comparative Example 1 were prepared in the same manner as in Example 1, except that the addition amounts of D liquid, H liquid, and silicone resin were adjusted as shown in Table 3. did. Further, in the same manner as in Example 1, except that the optical filter composition according to Examples 2 to 15 and Comparative Example 1 was used instead of the optical filter composition according to Example 1, each of the examples. Optical filters according to 2 to 15 and Comparative Example 1 were produced.

<Example 16>
Copper acetate monohydrate (4.500 g) and tetrahydrofuran (THF) (240 g) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 1.646 g of Prisurf A208N (Daiichi Kogyo Seiyaku Co., Ltd.), which is a phosphate ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain Liquid A. 40 g of THF was added to 0.769 g of paratoluenesulfonic acid and stirred for 30 minutes to obtain a solution B-1. 40 g of THF was added to 4.230 g of 4-bromobenzenesulfonic acid, and the mixture was stirred for 30 minutes to obtain a liquid B-2. Next, the B-1 liquid and the B-2 liquid were mixed and stirred for 1 minute. 8.664 g of methyltriethoxysilane (MTES: manufactured by Shin-Etsu Chemical Co., Ltd.) and tetraethoxysilane (TEOS: special grade manufactured by Kishida Chemical Co., Ltd.) 2.840g was added to this liquid mixture, and also it stirred for 1 minute, and B liquid was obtained. Liquid B was added to liquid A while stirring liquid A, and the mixture was stirred at room temperature for 1 minute. Next, after adding 140 g of toluene to this solution, it stirred at room temperature for 1 minute, and obtained C liquid. The solution C was put into a flask and heated with an oil bath (Tokyo Rika Kikai Co., Ltd., model: OSB-2100), and the solvent was removed by a rotary evaporator (Tokyo Rika Kikai Co., Ltd., model: N-1110SF). went. The set temperature of the oil bath was adjusted to 105 ° C. Thereafter, the liquid D according to Example 1 after the solvent removal treatment was taken out from the flask. The solvent removal treatment was carried out so that the viscosity of the liquid D was lowered to some extent without completely removing the solvent in the solvent removal treatment. Liquid D, which is a dispersion of fine particles of copper phenyl sulfonate (UV-IR absorber), was transparent, and the fine particles were well dispersed in Liquid D. The obtained D liquid was 107.12g. Table 1 shows the amount of toluene added to obtain the D liquid, the mass of the obtained D liquid, and the concentration of copper ions in the D liquid.

Copper acetate monohydrate (4.500 g) and THF (240 g) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 2.572 g of PRISURF A208N, which is a phosphate ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain solution E. Further, 40 g of THF was added to 2.886 g of 1-butanesulfonic acid and stirred for 30 minutes to obtain a liquid F. While stirring E solution, F solution was added to E solution and stirred at room temperature for 1 minute. Next, 84 g of toluene was added to this solution, followed by stirring at room temperature for 1 minute to obtain solution G. The solvent G was put into a flask and heated with an oil bath, and the solvent was removed by a rotary evaporator. The set temperature of the oil bath was adjusted to 105 ° C. Thereafter, the liquid H according to Example 1 after the solvent removal treatment was taken out of the flask. The solvent removal treatment was performed so that the viscosity of the liquid H became a predetermined viscosity without completely removing the solvent in the solvent removal treatment. The liquid H, which is a dispersion of fine particles of copper butanesulfonate (UV-IR absorber), was transparent, and the fine particles were well dispersed in the liquid H. The obtained liquid H was 68.12 g. Table 2 shows the amount of toluene added to obtain the H liquid, the mass of the obtained H liquid, and the concentration of copper ions in the H liquid.

10. Silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) was added to solution D and stirred for 30 minutes to obtain solution I. 27.25 g of liquid H corresponding to 40% by mass of the total amount of liquid H was added to liquid I and stirred for 30 minutes to obtain an optical filter composition according to Example 1. Table 3 shows the addition amounts of the D solution, the H solution, and the silicone resin in the optical filter composition according to Example 16.

Example An optical filter according to Example 16 was produced in the same manner as in Example 1 except that the optical filter composition according to Example 16 was used instead of the optical filter composition according to Example 1.

(Measurement of viscosity of optical filter composition)
Using a vibration viscometer (Seconic, probe: PR-10 L, controller: VM-10A), the viscosity at 22-23 ° C. of the optical filter composition according to each Example and Comparative Example 1 was measured. . The results are shown in Table 3. As shown in Table 3, the optical filter composition according to each example had a viscosity at 22 to 23 ° C. in the range of 1 to 200 mPa · s, whereas the optical filter composition according to Comparative Example 1 The viscosity at 22 to 23 ° C. was 330 mPa · s.

(Measurement of solid content of optical filter composition and calculation of solid content ratio)
Each example and comparative example 1 were laid on the bottom of a stainless steel tray with an aluminum sheet (manufactured by Sumi Light Aluminum Foil Co., Ltd., thickness: 12 μm) so that the thickness after curing was 100 to 300 μm. The composition for optical filters which concerns on was apply | coated, and the sample before hardening was prepared. The sample before curing was placed in an oven in which the internal temperature was maintained at 45 ° C., and the internal temperature of the oven was maintained at 45 ° C. for 2 hours. Thereafter, the temperature inside the oven was further raised to 85 ° C. over 30 minutes, and the temperature inside the oven was kept at 85 ° C. for 6 hours. Thereafter, the oven was turned off and allowed to cool naturally, and the sample was taken out of the oven after the temperature inside the oven had dropped to about room temperature. Next, the sample is put into a constant temperature and humidity chamber, and the inside of the constant temperature and humidity chamber is changed to an environment of a temperature of 85 ° C. and a relative humidity of 85% over 45 minutes. Kept. Then, after the temperature and humidity were sufficiently lowered for 45 minutes in the environment of the constant temperature and humidity chamber, the sample was taken out from the constant temperature and humidity chamber. The sample was fully dried and cured. The mass Wb of the sample after curing was measured, and the measurement result was determined as the mass of the solid content. From the mass Wb of the sample after curing and the mass Wa of the sample before curing, the solid content ratio (Wb / Wa × 100) in the optical filter composition according to each Example and Comparative Example 1 was determined. The results are shown in Table 3.

(Measurement of optical filter thickness)
Using a laser displacement meter (manufactured by Keyence Corporation, product name: LK-H008), the distance between the front and back surfaces of the optical filter according to each example and comparative example 1 is measured, and the optical according to each example and comparative example 1 is measured. The filter thickness was calculated. The results are shown in Table 4.

(Measure haze)
Using a haze meter (manufactured by Murakami Color Research Laboratory Co., Ltd., product name: HM-65L2), the haze of the optical filter according to each Example and Comparative Example 1 was measured in accordance with JIS K 7136: 2000.
The results are shown in Table 4.

(Measurement of spectral transmittance)
Using an ultraviolet visible spectrophotometer (product name: V-670, manufactured by JASCO Corporation), light having a wavelength of 300 nm to 1200 nm was incident on the optical filter according to each of the examples and the comparative example 1 at an incident angle of 0 °. The transmittance spectrum was measured. From this transmittance spectrum, the average transmittance at a wavelength of 450 to 600 nm, the average transmittance at a wavelength of 300 to 350 nm, the IR cut-off wavelength, and the UV cut-off wavelength are obtained for the optical filters according to the examples and comparative example 1. It was. The results are shown in Table 4. The transmittance spectra according to Examples 1, 4, 13, 14, and 15 and Comparative Example 1 are shown in FIGS. 3 to 8, respectively.

In the optical filter according to each example, the average transmittance at a wavelength of 450 nm to 600 nm was 78% or more, and the average transmittance at a wavelength of 300 nm to 350 nm was less than 0.2%. In the optical filter according to each example, the IR cutoff wavelength was in the range of 610 nm to 680 nm, and the UV cutoff wavelength was in the range of 380 nm to 430 nm. From this result, the optical filter according to each example had good transmittance characteristics. In addition, the haze of the optical filter according to each example was 5% or less. For this reason, the optical filter according to each example had good optical characteristics from the viewpoint of haze in addition to the transmittance characteristics.

In the optical filter according to Comparative Example 1, the average transmittance at a wavelength of 450 nm to 600 nm was 81.9%, and the average transmittance at a wavelength of 300 nm to 350 nm was less than 0.2%. In the optical filter according to each example, the IR cutoff wavelength was 631 nm, and the UV cutoff wavelength was 407 nm. From this result, the optical filter according to Comparative Example 1 had a good transmittance characteristic to some extent. On the other hand, the haze of the optical filter according to Comparative Example 1 was 8.4%, greatly exceeding 5%. For this reason, it was difficult to say that the optical filter according to Comparative Example 1 had desirable optical characteristics from the viewpoint of haze.

Claims

Comprising a UV-IR absorber layer comprising a UV-IR absorber capable of absorbing ultraviolet and infrared rays formed by at least one acid of phosphonic acid and sulfonic acid and copper ions;
Having a haze of 5% or less,
Optical filter.
When light with a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °,
(I) having an average transmittance of 78% or more at a wavelength of 450 nm to 600 nm;
(Ii) has a spectral transmittance of 1% or less at a wavelength of 300 nm to 350 nm,
(Iii) The first IR cut-off wavelength having a spectral transmittance that decreases with increasing wavelength at a wavelength of 600 nm to 750 nm and a spectral transmittance of 50% at a wavelength of 600 nm to 750 nm is within the wavelength range of 610 nm to 680 nm. Exists,
(Iv) The first UV cutoff wavelength having a spectral transmittance that increases with an increase in wavelength at a wavelength of 350 nm to 450 nm and a spectral transmittance of 50% at a wavelength of 350 nm to 450 nm is in the range of a wavelength of 380 nm to 430 nm. Exists,
The optical filter according to claim 1.
The optical filter according to claim 1 or 2, wherein the phosphonic acid includes a first phosphonic acid having an aryl group.
The optical filter according to claim 3, wherein the first phosphonic acid has, in part, a halogenated phenyl group in which at least one hydrogen atom in the phenyl group is substituted with a halogen atom.
The optical filter according to claim 3 or 4, wherein the phosphonic acid further includes a second phosphonic acid having an alkyl group.
An optical filter composition comprising:
Including at least one acid of phosphonic acid and sulfonic acid, and copper ion,
When the coating film of the optical filter composition is cured to form a layer having a thickness of 100 to 300 μm, the layer can absorb ultraviolet rays and infrared rays, and the haze of the layer is 5% or less. is there,
Composition.
When light having a wavelength of 300 nm to 1200 nm is incident on the layer at an incident angle of 0 °,
(I) having an average transmittance of 78% or more at a wavelength of 450 nm to 600 nm,
(II) has a spectral transmittance of 1% or less at a wavelength of 300 nm to 350 nm,
(III) The first IR cutoff wavelength having a spectral transmittance that decreases with an increase in wavelength at a wavelength of 600 nm to 750 nm and a spectral transmittance of 50% at a wavelength of 600 nm to 750 nm is within the wavelength range of 610 nm to 680 nm. Exists,
(IV) The first UV cut-off wavelength having a spectral transmittance that increases with an increase in wavelength at a wavelength of 350 nm to 450 nm and a spectral transmittance of 50% at a wavelength of 350 nm to 450 nm is in the range of a wavelength of 380 nm to 430 nm. Exists,
The composition according to claim 6.
The composition according to claim 6 or 7, which has a viscosity of 1 to 200 mPa · s at 22 to 23 ° C.
The composition according to any one of claims 6 to 8, wherein the solid content is 3 to 17% by mass.
The composition according to any one of claims 6 to 9, wherein the copper ion content is 0.5 to 2.2 mass%.