JP2011203467A - Near-infrared absorption filter and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a near-infrared absorption filter superior in near-infrared absorption characteristics, visible light transmissivity, and environmental resistance, and to provide a method for manufacturing the near-infrared absorption filter with high productivity.SOLUTION: The near-infrared absorption filter comprises: an infrared absorbent obtained from a phosphonic acid compound, at least one kind of phosphoric ester compounds, and a copper salt; and a resin.

Description

  The present invention relates to a near-infrared absorbing filter and a method for producing the same, and more particularly to a resin-made near-infrared absorbing filter capable of suitably absorbing near-infrared rays and having excellent transparency and a method for producing the same.

Among metal ions, copper ions have excellent absorption characteristics of light in the near infrared region (hereinafter also referred to as “near infrared”).
Conventionally, optical materials using near-infrared absorption characteristics of copper ions have been proposed (see, for example, Patent Documents 1 to 4). Patent Document 1 discloses an optical material containing a phosphate ester copper compound formed from a specific phosphate ester compound and a copper compound. Patent Document 2 discloses a display front plate formed from a resin composition containing a specific phosphate compound, a copper compound, and a resin. Patent Document 3 discloses an optical filter having a near-infrared absorbing layer containing a phosphate ester copper compound formed from a specific phosphate ester compound and a copper compound. Patent Document 4 discloses a near-infrared absorbing composition comprising a specific phosphate compound and copper ions.

  Conventionally proposed optical materials have excellent near infrared absorption characteristics when used as near infrared absorption filters. However, near-infrared absorption filters for display panels, silicon photodiodes, and the like are desired to have excellent near-infrared absorption characteristics and excellent visible light transmission properties, but conventionally proposed optical materials are visible. The light transmission was not sufficient, and improvement was still desired. In the various optical materials described in the above-mentioned patent documents, copper ions are mainly contained in the optical material as a complex obtained by reacting a phosphate ester compound with a copper salt (copper compound).

  In recent years, various electronic devices are strongly required to be small, save space, and light. Therefore, the near-infrared absorption filter is required to reduce the thickness of the filter itself while maintaining excellent near-infrared absorption characteristics.

  However, none of the inventions described in Patent Documents 1 to 4 have sufficient absorption characteristics of near infrared rays when the thickness of the filter itself is reduced.

JP 2001-83318 A JP 2001-83890 A JP 2001-154015 A International Publication No. 01/77250 Pamphlet

  In order to reduce the filter thickness while maintaining the near-infrared absorption characteristics, it is necessary to increase the concentration of copper ions that contribute to the near-infrared absorption characteristics. It is necessary to manufacture a filter. However, when the complex concentration in the raw material is increased, there is a problem that the productivity is lowered because the moldability generally deteriorates.

  In addition, when the copper ion concentration is increased to make the filter thinner, the environmental resistance such as moisture resistance and heat resistance of the filter generally tends to deteriorate, but various portable devices often used outdoors. The near-infrared absorption filter used in the production is required to have excellent environmental resistance.

  In addition, it is naturally desirable that the near-infrared absorption filter used in the display unit of the display is excellent in visible light transmission from the viewpoint of display visibility. It is desired that a near infrared resin filter used as a visibility correction filter for a light receiving portion such as a photodiode is also excellent in visible light transmission.

  In view of the circumstances as described above, the present invention has a near-infrared absorption filter excellent in near-infrared absorption characteristics and excellent in visible light transmittance and excellent in environmental resistance, and productivity of the near-infrared absorption filter. The object is to provide a method of manufacturing well.

  As a result of intensive studies to solve the above problems, the present inventors have found that a specific near-infrared absorption filter has excellent near-infrared absorption characteristics, excellent visible light transmission, and environmental resistance. And the near-infrared absorption filter was found to be excellent in productivity, and the present invention was completed.

  That is, the near-infrared absorption filter of the present invention is represented by the phosphonic acid compound represented by the following general formula (1), the phosphoric acid ester compound represented by the following general formula (2a), and the following general formula (2b). It is formed from the near-infrared absorber and resin obtained from the at least 1 sort (s) of phosphoric acid ester compound selected from this, and a copper salt.

［式中、Ｒ¹は、−ＣＨ₂ＣＨ₂−Ｒ¹¹で表される１価の基であり、Ｒ¹¹は水素原子、炭素数１〜２０のアルキル基、または炭素数１〜２０のフッ素化アルキル基を示す。Ｒ²¹、Ｒ²²およびＲ²³は、−（ＣＨ₂ＣＨ₂Ｏ）_nＲ⁵で表される１価の基であり、ｎは４〜２５の整数であり、Ｒ⁵は、炭素数６〜２５のアルキル基または炭素数６〜２５のアルキルフェニル基を示す。ただし、Ｒ²¹、Ｒ²²およびＲ²³は、それぞれ同一でも異なっていてもよい。］

[In the formula, R ¹ is a monovalent group represented by ^{_{-CH 2 CH 2 -R 11, R}} 11 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a fluorine having 1 to 20 carbon atoms, Represents an alkyl group. R ²¹ , R ²² and R ²³ are monovalent groups represented by — (CH ₂ CH ₂ O) _n R ⁵ , n is an integer of 4 to 25, and R ⁵ has 6 to 6 carbon atoms. 25 alkyl group or C6-C25 alkylphenyl group is shown. However, R ²¹ , R ²² and R ²³ may be the same or different. ]

  The near-infrared absorption filter of the present invention includes a phosphonic acid compound represented by the general formula (1), a phosphoric acid ester compound represented by the general formula (2a), and a phosphorus represented by the general formula (2b). By mixing at least one phosphate ester compound selected from acid ester compounds and a copper salt in a solvent to obtain a reaction mixture, and removing at least part of the solvent from the reaction mixture A near-infrared absorber and a resin obtained by obtaining a near-infrared absorber, dispersing the near-infrared absorber in a monomer, obtaining a near-infrared absorber-containing monomer, and polymerizing the near-infrared absorber-containing monomer It is preferable to form from the composition containing this.

  The near-infrared absorption filter of the present invention includes a phosphonic acid compound represented by the general formula (1), a phosphoric acid ester compound represented by the general formula (2a), and a phosphorus represented by the general formula (2b). By mixing at least one phosphate ester compound selected from acid ester compounds and a copper salt in a solvent to obtain a reaction mixture, and removing at least part of the solvent from the reaction mixture By obtaining a near-infrared absorbent, obtaining a dispersion by dispersing the near-infrared absorbent in a low-boiling solvent, adding a monomer to the dispersion, and then removing at least part of the low-boiling solvent A near infrared ray formed from a composition comprising a near infrared absorber and a resin, obtained by polymerizing the near infrared absorber-containing monomer, obtaining a near infrared absorber-containing monomer Absorption filter.

  The resin has a structural unit derived from at least one monomer selected from a monofunctional aromatic vinyl compound, a polyfunctional aromatic vinyl compound, a monofunctional (meth) acrylic acid ester, and a polyfunctional (meth) acrylic acid ester. It is preferable. Moreover, it is preferable that at least a part of the monomer is at least one monomer selected from a polyfunctional (meth) acrylic acid ester and a polyfunctional aromatic vinyl compound.

  The manufacturing method of the near-infrared absorption filter of the present invention is represented by the phosphonic acid compound represented by the general formula (1), the phosphoric acid ester compound represented by the general formula (2a), and the general formula (2b). A step of mixing a copper salt with at least one phosphate ester compound selected from the phosphate ester compounds to be obtained in a solvent, and removing at least a part of the solvent from the reaction mixture A step of obtaining a near-infrared absorber by dispersing the near-infrared absorber in a monomer, obtaining a near-infrared absorber-containing monomer, polymerizing the near-infrared absorber-containing monomer, Obtaining a composition comprising.

  As another aspect of the manufacturing method of the near-infrared absorption filter of this invention, the phosphonic acid compound represented by the said General formula (1), the phosphate ester compound represented by the said General formula (2a), and the said General formula The step of mixing at least one phosphate ester compound selected from the phosphate ester compounds represented by (2b) and a copper salt in a solvent to obtain a reaction mixture, from the reaction mixture, at least the solvent A step of obtaining a near-infrared absorber by removing a part of the step, a step of obtaining a dispersion by dispersing the near-infrared absorber in a low-boiling solvent, and after adding a monomer to the dispersion, at least a low-boiling solvent A step of obtaining a near-infrared absorber-containing monomer by removing a part of the composition, polymerizing the near-infrared absorber-containing monomer, and a composition comprising a near-infrared absorber and a resin A step of obtaining a.

  The near-infrared absorption filter of the present invention has excellent near-infrared absorption characteristics, excellent visible light transparency, and excellent environmental resistance. Moreover, the manufacturing method of the near-infrared absorption filter of this invention can manufacture this near-infrared absorption filter with sufficient productivity.

The spectral transmission factor of the resin board (near-infrared absorption filter) obtained in Example 1 and Comparative Example 1 is shown. The spectral transmittance of the resin plate (near infrared absorption filter) obtained in Example 2 is shown. The spectral transmittance of the resin plate (near infrared absorption filter) obtained in Example 3 is shown. The change of the haze of the resin board at the time of hold | maintaining the resin board (near-infrared absorption filter) obtained in Example 2 and Comparative Example 1 at 60 degreeC and 90% of relative humidity is shown.

Next, the present invention will be specifically described.
The near-infrared absorption filter of the present invention includes a phosphonic acid compound represented by the following general formula (1), a phosphoric acid ester compound represented by the following general formula (2a), and a phosphorus represented by the following general formula (2b). It is formed from a near-infrared absorber and resin obtained from at least one phosphate ester compound selected from acid ester compounds and a copper salt.

［式中、Ｒ¹は、−ＣＨ₂ＣＨ₂−Ｒ¹¹で表される１価の基であり、Ｒ¹¹は水素原子、炭素数１〜２０のアルキル基、または炭素数１〜２０のフッ素化アルキル基を示す。Ｒ²¹、Ｒ²²およびＲ²³は、−（ＣＨ₂ＣＨ₂Ｏ）_nＲ⁵で表される１価の基であり、ｎは４〜２５の整数であり、Ｒ⁵は、炭素数６〜２５のアルキル基または炭素数６〜２５のアルキルフェニル基を示す。ただし、Ｒ²¹、Ｒ²²およびＲ²³は、それぞれ同一でも異なっていてもよい。］

[In the formula, R ¹ is a monovalent group represented by ^{_{-CH 2 CH 2 -R 11, R}} 11 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a fluorine having 1 to 20 carbon atoms, Represents an alkyl group. R ²¹ , R ²² and R ²³ are monovalent groups represented by — (CH ₂ CH ₂ O) _n R ⁵ , n is an integer of 4 to 25, and R ⁵ has 6 to 6 carbon atoms. 25 alkyl group or C6-C25 alkylphenyl group is shown. However, R ²¹ , R ²² and R ²³ may be the same or different. ]

<Near infrared absorber>
The near infrared absorbing filter of the present invention contains a near infrared absorbing agent.
The near-infrared absorber includes a phosphonic acid compound represented by the general formula (1), a phosphoric acid ester compound represented by the general formula (2a), and a phosphoric acid ester represented by the general formula (2b). It is obtained from at least one phosphate ester compound selected from compounds and a copper salt.

  In the present invention, the “phosphonic acid compound represented by the general formula (1)” is also referred to as “specific phosphonic acid compound”, and the phosphoric acid ester compound represented by the general formula (2a) and the general formula ( The “at least one phosphate ester compound selected from the phosphate ester compounds represented by 2b)” is also referred to as “specific phosphate ester compound”.

  The near-infrared absorber used in the present invention is considered to have near-infrared absorption characteristics mainly due to copper ions contained in the phosphonic acid copper salt obtained by reacting the specific phosphonic acid compound with the copper salt. The phosphonic acid copper salt is considered to be maintained in a very fine state by the action of the specific phosphate compound. Since the near-infrared absorbing agent present in the near-infrared absorbing filter of the present invention exists as fine particles, the near-infrared absorbing filter of the present invention is excellent in visible light transmittance.

  Moreover, it is thought that the said specific phosphonic acid compound coordinates mainly with respect to a copper ion, and also the said specific phosphoric acid ester compound exists around the near-infrared absorber used for this invention. For this reason, the copper ion in the near-infrared absorber is excellent in stability to heat and the like. For example, when the near-infrared absorption filter is produced from the near-infrared absorber and the monomer, the monomer is polymerized at a high temperature. Even if it exists, the near-infrared absorption filter obtained does not receive the influence of a copper ion, and there is little coloring and it is excellent in transparency.

In the phosphonic acid compound represented by the general formula (1), R ¹ is a monovalent group represented by —CH ₂ CH ₂ —R ¹¹ . R ¹¹ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a fluorinated alkyl group having 1 to 20 carbon atoms. The fluorinated alkyl group is one in which part or all of the hydrogen atoms in the corresponding alkyl group are substituted with fluorine atoms.

  By using such a specific phosphonic acid compound, the near-infrared absorption filter of the present invention has excellent near-infrared absorption characteristics, excellent visible light permeability, and excellent environmental resistance such as heat resistance.

As the specific phosphonic acid compound, those in which R ¹¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms are preferable. Examples of the phosphonic acid compound represented by the general formula (1) include ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid, pentylphosphonic acid, hexylphosphonic acid, heptylphosphonic acid, octylphosphonic acid, nonylphosphonic acid, and decylphosphonic acid. Examples thereof include alkylphosphonic acids such as acid, undecylphosphonic acid, dodecylphosphonic acid, tridecylphosphonic acid, tetradecylphosphonic acid, pentadecylphosphonic acid, hexadecylphosphonic acid, heptadecylphosphonic acid, and octadecylphosphonic acid. In addition, as a phosphonic acid compound represented by General formula (1), you may use individually by 1 type, or may use 2 or more types.

In at least one phosphate ester compound selected from the phosphate ester compound represented by the general formula (2a) and the phosphate ester compound represented by the general formula (2b), R ²¹ , R ²² and R ²³ is a monovalent group (polyoxyalkyl group) represented by — (CH ₂ CH ₂ O) _n R ⁵ . n is an integer of 4 to 25, and more preferably an integer of 6 to 15.
When n is less than 4, the transparency of the infrared absorption filter is insufficient. On the other hand, when n exceeds 25, the amount of the phosphoric acid ester compound necessary for obtaining an infrared absorption filter having sufficient transparency increases, resulting in high costs.

R ⁵ is an alkyl group having 6 to 25 carbon atoms or an alkylphenyl group having 6 to 25 carbon atoms, preferably an alkyl group having 6 to 25 carbon atoms, and is an alkyl group having 12 to 20 carbon atoms. Is more preferable. When R ⁵ is a group having less than 6 carbon atoms, the near-infrared absorbing filter has insufficient transparency. Further, if R ⁵ is a group having more than 25 carbon atoms, the amount of the phosphoric acid ester compound necessary for obtaining an infrared absorption filter having sufficient transparency increases, resulting in high costs.

  When obtaining the near-infrared absorber used in the present invention, at least one of the phosphate compound represented by the general formula (2a) and the phosphate compound represented by the general formula (2b) is used. It is preferable to use both the phosphate compound represented by the general formula (2a) and the phosphate compound represented by the general formula (2b). When the phosphate ester compound represented by the general formula (2a) and the phosphate ester compound represented by the general formula (2b) are used, the near-infrared absorption filter tends to be excellent in transparency and heat resistance. When both the phosphate compound represented by the general formula (2a) and the phosphate compound represented by the general formula (2b) are used, the phosphate compound represented by the general formula (2a) The ratio of the phosphoric acid ester compound represented by the general formula (2b) is not particularly limited, but is usually 10:90 to 90:10 in molar ratio ((2a) :( 2b)).

  Moreover, as a phosphate ester compound represented by the said General formula (2a), it may be used individually by 1 type, or 2 or more types may be used, As a phosphate ester compound represented by the said General formula (2b) May be used alone or in combination of two or more.

Moreover, when obtaining a near-infrared absorber, you may further use another phosphorus compound, for example, phosphoric acid triester.
As at least one phosphate ester compound selected from the phosphate ester compound represented by the general formula (2a) and the phosphate ester compound represented by the general formula (2b), commercially available phosphoric acid An ester compound can also be used.

  As the copper salt, a copper salt capable of supplying divalent copper ions is usually used. Examples of the copper salt include copper of organic acids such as anhydrous copper acetate, anhydrous copper formate, anhydrous copper stearate, anhydrous copper benzoate, anhydrous ethyl acetoacetate copper, anhydrous pyrophosphate, anhydrous naphthenic acid copper, and anhydrous copper citrate. Salt, hydrate or hydrate of copper salt of organic acid; copper salt of inorganic acid such as copper oxide, copper chloride, copper sulfate, copper nitrate, basic copper carbonate, hydrate of copper salt of inorganic acid Or a hydrate; copper hydroxide is mentioned. In addition, as a copper salt, you may use individually by 1 type, or may use 2 or more types.

As the copper salt, anhydrous copper acetate and copper acetate monohydrate are preferably used from the viewpoint of solubility and removal of by-products.
The near-infrared absorber used in the present invention is represented by the phosphonic acid compound represented by the general formula (1), the phosphate compound represented by the general formula (2a), and the general formula (2b). It is obtained from at least one phosphate ester compound selected from phosphoric acid ester compounds and a copper salt. Although the near-infrared absorber may contain each component itself, the near-infrared absorber usually contains a component produced by the reaction of each component. Specifically, as the near-infrared absorber used in the present invention, there is a phosphonic acid copper salt obtained by reacting the specific phosphonic acid compound with a copper salt, and the specific phosphoric acid ester compound is present around the phosphonic acid copper compound. Presumed to exist. Further, it is considered that there is also a phosphonic acid copper salt in which a part of the specific phosphonic acid compound constituting the phosphonic acid copper salt is replaced with the specific phosphoric acid ester compound.

  The near-infrared absorbing filter of the present invention is formed from a near-infrared absorbing agent and a resin, but the phosphonic acid copper salt is preferably dispersed in the resin mainly in the form of particles. Since the said phosphonic acid copper salt comprises a near-infrared absorber with the said specific phosphate ester compound, it is thought that it becomes a fine particle in resin. The average particle diameter of the phosphonic acid copper salt is preferably 250 nm or less, more preferably 10 to 200 nm. When the fine phosphonic acid copper salt particles are dispersed in the resin, the near-infrared absorbing filter of the present invention has excellent transparency and heat resistance.

  The amount of each component used when the near-infrared absorber used in the present invention is obtained from the specific phosphonic acid compound, the specific phosphoric acid ester compound and the copper salt is as follows. The specific phosphonic acid compound is preferably used in an amount of 5 mol or more, more preferably 8 to 100 mol, and particularly preferably 10 to 80 mol, per 1 mol of the specific phosphate compound. If it is less than 5 mol, the near-infrared absorption filter is excellent in transparency, but the near-infrared absorption characteristics may be deteriorated or the heat resistance may be lowered.

  Further, the specific phosphonic acid compound is preferably 0.4 mol or more, more preferably 0.5 to 1.5 mol, more preferably 0.5 to 1 per 1 mol of copper in the copper salt. Particularly preferred is 2 moles. Within the said range, since the transparency and heat resistance of a near-infrared absorption filter are especially excellent, it is preferable.

<Method for producing near-infrared absorber>
As a manufacturing method of the near-infrared absorber used for this invention, the process of obtaining the reaction mixture by mixing the said specific phosphonic acid compound, the said specific phosphate ester compound, and the said copper salt in a solvent, for example. (Hereinafter also referred to as a reaction step), and a method having a step of obtaining a near-infrared absorber by removing at least a part of the solvent from the reaction mixture (hereinafter also referred to as a solvent removal step).

  In the reaction step, particulate copper phosphonate that does not dissolve in the solvent due to the reaction of the specific phosphonic acid compound and the copper salt mainly in the presence of the specific phosphate compound. A salt is formed. Since the phosphoric ester compound can act as a good dispersant during the reaction, the phosphonic acid copper salt can be kept highly dispersible and can suppress aggregation.

  In the reaction step, not only the reaction between the specific phosphonic acid compound and the copper salt but also the specific phosphate compound and the copper salt may react, for example. In addition, the specific phosphonic acid compound, the specific phosphate ester compound, and a part of the copper salt may remain without reacting.

  Examples of the solvent used in the reaction step include alcohols such as methanol and ethanol, tetrahydrofuran (THF), dimethylformamide (DMF), water, and the like, and ethanol, THF, or DMF is preferable from the viewpoint of satisfactory reaction. The reaction step is preferably performed at room temperature to 60 ° C, more preferably 20 to 40 ° C, preferably 0.5 to 5 hours, more preferably 1 to 3 hours.

The near-infrared absorber used in the present invention is usually obtained by removing at least a part of the solvent from the reaction mixture.
The reaction mixture obtained in the reaction step includes the phosphonic acid copper salt, the specific phosphoric acid ester compound, the specific phosphonic acid compound, a copper salt, a by-product, the solvent used in the reaction step, and the like.

In the solvent removal step, at least a part of the solvent is removed from the reaction mixture. In the solvent removal step, in addition to the solvent, the liquid components in the reaction mixture may be removed together.
In the solvent removal step, at least a part of the solvent is usually removed by heating the reaction mixture, but the heating condition is usually room temperature to 70 ° C, preferably 40 to 60 ° C. The solvent removal step may be performed under normal pressure or under reduced pressure. When the solvent removal step is performed under reduced pressure, heating may not be performed or the heating temperature may be low.

<Resin>
The near-infrared absorption filter of the present invention is formed from the near-infrared absorber and resin.
The resin used in the present invention is derived from at least one monomer selected from monofunctional aromatic vinyl compounds, polyfunctional aromatic vinyl compounds, monofunctional (meth) acrylic acid esters and polyfunctional (meth) acrylic acid esters. It is preferable from a viewpoint of the transparency of a near-infrared absorption filter, and heat resistance. Moreover, it is preferable that at least a part of the monomer is at least one monomer selected from a polyfunctional (meth) acrylic acid ester and a polyfunctional aromatic vinyl compound.

In the present invention, “(meth) acrylic acid” means “methacrylic acid” and “acrylic acid”.
Examples of the monofunctional aromatic vinyl compound include styrene, α-methylstyrene, ethylstyrene, tert-butylstyrene, chlorostyrene, dibromostyrene, methoxystyrene, vinylbenzoic acid, and hydroxymethylstyrene.

Examples of the polyfunctional aromatic vinyl compound include divinylbenzene, diisopropenylbenzene, and trivinylbenzene.
Examples of monofunctional (meth) acrylic acid esters include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, isodecyl acrylate, isodecyl methacrylate, n-lauryl acrylate, n-lauryl methacrylate, tridecyl acrylate, tridecyl methacrylate, n-stearyl acrylate, n-stearyl methacrylate, isobornyl acrylate , Isobornyl methacrylate, benzyl acrylate, benzyl methacrylate, methoxy Examples include ethyl acrylate, methoxyethyl methacrylate, ethoxyethyl acrylate, ethoxyethyl methacrylate, phenoxyethyl acrylate, and phenoxyethyl methacrylate.

  Examples of the polyfunctional (meth) acrylic acid ester include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 2,2-bis ( 4-methacryloxyethoxyphenyl) propane, tricyclodecane dimethanol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate.

  As described above, the resin used in the present invention is at least one selected from a monofunctional aromatic vinyl compound, a polyfunctional aromatic vinyl compound, a monofunctional (meth) acrylic acid ester, and a polyfunctional (meth) acrylic acid ester. Although it is preferable to have a structural unit derived from the monomer, it is derived from a monofunctional monomer such as a monofunctional aromatic vinyl compound or a monofunctional (meth) acrylate per 100% by weight of all the structural units constituting the resin. It is preferable to have 95 to 50% by weight of structural units and 5 to 50% by weight of structural units derived from polyfunctional monomers such as polyfunctional aromatic vinyl compounds and polyfunctional (meth) acrylic acid esters. In addition, the reliability of the resin is that it has 40% by weight or more of structural units derived from (meth) acrylic acid ester monomers, that is, structural units derived from monofunctional (meth) acrylic acid esters and polyfunctional (meth) acrylic acid esters. From the viewpoint of sex.

  In the present invention, the near-infrared absorbing filter is formed from the near-infrared absorbing agent and the resin. The near-infrared absorbing agent is usually 1 to 30 parts by weight, preferably 2 to 20 parts per 100 parts by weight of the resin. Part by weight is used.

<Near infrared absorption filter>
The near-infrared absorption filter of the present invention is formed from the aforementioned near-infrared absorber and resin. The near-infrared absorption filter of the present invention has excellent near-infrared absorption characteristics, excellent visible light transparency, and excellent environmental resistance.

  The near-infrared absorption filter of the present invention may be produced by molding a composition obtained by kneading the near-infrared absorber in a resin. However, in this method, the near-infrared absorber may be unevenly distributed in the resulting composition. Therefore, when manufacturing a near-infrared absorption filter, normally, a monomer is polymerized in the presence of a near-infrared absorber to obtain a composition containing a near-infrared absorber and a resin. When the polymerization is carried out under the condition that the shape of the composition becomes a filter, the composition obtained by the polymerization can be used as a near infrared absorption filter. Moreover, you may obtain a near-infrared absorption filter by shape | molding the obtained composition further, such as cutting | disconnection and grinding | polishing.

Specific examples of the near infrared absorption filter of the present invention include the following two embodiments.
The near-infrared absorption filter of the first aspect is represented by the phosphonic acid compound represented by the general formula (1), the phosphate compound represented by the general formula (2a), and the general formula (2b). At least one phosphate ester compound selected from phosphoric acid ester compounds and a copper salt are mixed in a solvent to obtain a reaction mixture, and at least a part of the solvent is removed from the reaction mixture. A near infrared absorber obtained by dispersing the near infrared absorber in a monomer to obtain a near infrared absorber-containing monomer and polymerizing the near infrared absorber-containing monomer. And a near-infrared absorption filter formed from a composition containing a resin.

  The near-infrared absorption filter of the second aspect is represented by the phosphonic acid compound represented by the general formula (1), the phosphoric acid ester compound represented by the general formula (2a), and the general formula (2b). At least one phosphate ester compound selected from phosphoric acid ester compounds and a copper salt are mixed in a solvent to obtain a reaction mixture, and at least a part of the solvent is removed from the reaction mixture. To obtain a near-infrared absorber, disperse the near-infrared absorber in a low-boiling solvent, obtain a dispersion, add a monomer to the dispersion, and then remove at least a portion of the low-boiling solvent. The near-infrared absorber-containing monomer is obtained, and the near-infrared absorber-containing monomer is obtained by polymerizing the near-infrared absorber-containing monomer. It is an outside line absorption filter.

  That is, in the first aspect, a near-infrared absorber-containing monomer is obtained by directly dispersing a near-infrared absorber obtained by removing at least a part of the solvent from the reaction mixture in the monomer. In contrast, in the second embodiment, a dispersion is obtained by dispersing a near-infrared absorber obtained by removing at least a part of the solvent from the reaction mixture in a low-boiling solvent. The near-infrared absorber-containing monomer is obtained by adding a monomer to the obtained dispersion and then removing the low-boiling solvent.

  In both the first and second embodiments, the near-infrared absorber is dispersed without being unevenly distributed in the obtained near-infrared absorption filter by dispersing the near-infrared absorber in the monomer instead of the resin. The near-infrared absorption filter has excellent near-infrared absorption characteristics and excellent transparency.

  As in the second embodiment, when the near-infrared absorber is once dispersed in the low boiling point solvent and the monomer is added to the obtained separation liquid, the near-infrared absorber tends to disperse more uniformly in the near-infrared absorption filter. Is preferable.

  Although the near-infrared absorption filter of this invention consists of the said near-infrared absorber and resin, it may contain various additives further. Examples of the additive include an antioxidant, an ultraviolet absorber, a light stabilizer, a polymerization rate adjusting agent, and a chain transfer agent.

Although there is no limitation in particular as the thickness of the near-infrared absorption filter of this invention, Usually, they are 0.1 mm-3.0 mm.
The near-infrared absorption filter of the present invention can be used as various filters that are required to absorb near-infrared rays. Specific examples include a near-infrared cut filter and a color purity correction filter. Since the near-infrared absorption filter of the present invention has excellent near-infrared absorption properties and excellent environmental resistance, the thickness of the filter can be made thinner than before. In addition, the near-infrared absorption filter of the present invention is also excellent in transparency of visible light, so that a near-infrared cut filter installed on the display surface of the display, a visibility correction installed in a light receiving unit such as a photodiode, etc. The filter can be used as a visibility correction filter for a camera using an image sensor such as a CCD element or a C-MOS element. It is also possible to create a filter that absorbs a specific wavelength and near-infrared region by combining with other dyes.

<Method for manufacturing near-infrared absorbing filter>
As a manufacturing method of the near-infrared absorption filter of this invention, there exist the following two aspects.
In the method for producing a near-infrared absorption filter of the first aspect, the specific phosphonic acid compound, the specific phosphate ester compound, and a copper salt are mixed in a solvent to obtain a reaction mixture ((I ) Step), a step of obtaining a near-infrared absorber by removing at least a part of the solvent from the reaction mixture (step (II)), the near-infrared absorber is dispersed in a monomer, and a near-infrared absorber is contained. A method for producing a near-infrared absorption filter comprising a step of obtaining a monomer (step (III)), a step of polymerizing the near-infrared absorber-containing monomer to obtain a composition containing a near-infrared absorber and a resin (step (IV)). It is.

  In the method for producing a near-infrared absorption filter of the second aspect, the specific phosphonic acid compound, the specific phosphoric acid ester compound, and a copper salt are mixed in a solvent to obtain a reaction mixture ((i ) Step), a step of obtaining a near-infrared absorber by removing at least part of the solvent from the reaction mixture (step (ii)), and a dispersion liquid by dispersing the near-infrared absorber in a low-boiling solvent. (Step (iii)), after adding a monomer to the dispersion, removing at least part of the low-boiling solvent to obtain a near-infrared absorber-containing monomer (step (iv)), It is a manufacturing method of the near-infrared absorption filter which has the process ((v) process) which superpose | polymerizes a near-infrared absorber containing monomer and obtains the composition containing a near-infrared absorber and resin.

  Steps (I) and (II) of the method for producing a near-infrared absorption filter of the first embodiment are the same as steps (i) and (ii) of the method for producing a near-infrared absorption filter of the second embodiment. These correspond to the reaction step and the solvent removal step described in the above section <Method for producing near-infrared absorber>, respectively.

The (III) process of the manufacturing method of the near-infrared absorption filter of a 1st aspect is a process of disperse | distributing a near-infrared absorber to a monomer and obtaining a near-infrared absorber containing monomer.
As a method for dispersing the near-infrared absorber in the monomer, for example, the monomer is added to the near-infrared absorber, and the near-infrared absorber is dispersed in the monomer by a method such as ultrasonic irradiation, homogenizer, stirring, and warming stirring. A method is mentioned.

In addition, when disperse | distributing a near-infrared absorber to a monomer, a near-infrared absorber may be disperse | distributed to a part of monomer, and the remaining monomer may be added after that and it may mix further.
Further, in the step (IV) described later, in order to polymerize the monomer suitably, a radical polymerization initiator is usually added at the same time as or after the near infrared absorber is dispersed in the monomer, and radical polymerization is performed. It is preferable to obtain a near infrared absorber-containing monomer containing an initiator.

The (iii) process of the manufacturing method of the near-infrared absorption filter of a 2nd aspect is a process of obtaining a dispersion liquid by disperse | distributing a near-infrared absorber in a low boiling-point solvent.
As the low boiling point solvent, a boiling point of 35 ° C. to 80 ° C. is usually used, and a solvent capable of dispersing the near infrared absorber is used. As the low boiling point solvent, for example, methylene chloride, acetone, methanol, chloroform and the like are used.

  As a method for dispersing the near-infrared absorber in the low-boiling solvent, for example, a low-boiling solvent is added to the near-infrared absorber, and the near-infrared absorber is reduced by a method such as ultrasonic irradiation, homogenizer, stirring, and warming stirring. The method of making it disperse | distribute in a boiling point solvent is mentioned.

  In the step (iv) of the method for producing a near-infrared absorption filter of the second aspect, after adding the monomer to the dispersion, at least a part of the low-boiling solvent is removed to obtain a near-infrared absorber-containing monomer. It is a process.

  In the step (iv), it is preferable to dissolve the monomer in the dispersion by adding the monomer to the dispersion obtained in the step (iii). Subsequently, the near-infrared absorber-containing monomer in which the near-infrared absorber is dispersed can be obtained by removing the low boiling point solvent.

The method for removing the low boiling point solvent is not particularly limited, and examples thereof include removal of the low boiling point solvent by reduced pressure, removal by a combination of heating and reduced pressure, and the like.
In addition, when adding a monomer to a dispersion liquid, after adding a part of monomer to a dispersion liquid and removing a low boiling-point solvent, the remaining monomer may be added further and mixing may be performed.

  Further, in the step (v) described later, in order to polymerize the monomer suitably, a radical polymerization initiator is usually added at the same time as or after the monomer is added to the dispersion, and the radical polymerization initiator is added. It is preferable to obtain a near-infrared absorber-containing monomer.

  The monomer preferably includes at least one monomer selected from a monofunctional aromatic vinyl compound, a polyfunctional aromatic vinyl compound, a monofunctional (meth) acrylic acid ester, and a polyfunctional (meth) acrylic acid ester.

  A polyfunctional aromatic vinyl compound or polyfunctional (meth) acrylic is used by using 95 to 50 wt% of a monofunctional monomer such as a monofunctional aromatic vinyl compound or monofunctional (meth) acrylate per 100% by weight of all monomers used. It is preferable to use 5 to 50% by weight of a polyfunctional monomer such as an acid ester. Moreover, it is preferable from the viewpoint of the reliability of resin obtained to use (meth) acrylic acid ester monomer, ie, monofunctional (meth) acrylic acid ester, and polyfunctional (meth) acrylic acid ester 40weight% or more.

  The radical polymerization initiator is not particularly limited, and for example, an organic peroxide polymerization initiator or an azo radical polymerization initiator can be used. Examples of the organic peroxide polymerization initiator include tert-butyl peroctanoate, tert-butyl peroxyneodecanate, tert-butyl peroxypivalate, tert-butyl peroxy-2-ethylhexanoate, Use of non-aromatic peroxyesters such as tert-butylperoxylaurate, diacyl peroxides such as lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, etc. It is preferable in terms of few points. As the azo radical polymerization initiator, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile) 1,1′-azobis (cyclohexane-2-carbonitrile) ) Etc. can be used. The radical polymerization initiator is used in an amount of 0.3 to 5.0 parts by weight with respect to 100 parts by weight of the monomer.

  The (IV) step of the manufacturing method of the near-infrared absorption filter of the first embodiment and the (v) step of the manufacturing method of the near-infrared absorption filter of the second embodiment are the same steps (hereinafter also referred to as polymerization step). And a step of polymerizing a near-infrared absorber-containing monomer to obtain a composition containing a near-infrared absorber and a resin. In this step, the monomer is polymerized to become a resin. Usually, a near-infrared absorber-containing monomer containing a radical polymerization initiator is used, and radical polymerization is performed in this step. The polymerization step may be performed by a cast polymerization method, for example, as long as the near-infrared absorber-containing monomer is polymerized.

  In the polymerization step of the present invention, a composition containing a near-infrared absorber and a resin is obtained. However, since the composition is difficult to mold such as melt molding, the composition is obtained by a casting polymerization method using a mold or the like. Polymerization is preferably carried out under the condition that the shape of the product is obtained on a filter, that is, as a near infrared absorption filter. In particular, when a polyfunctional monomer such as a polyfunctional (meth) acrylic acid ester or a polyfunctional aromatic vinyl compound is used, the resulting composition is excellent in heat resistance and difficult to thermoform. It is preferable to carry out the polymerization under the condition that the product is obtained as a near infrared absorption filter.

  EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited by these.

[Example 1]
A solution (a1) obtained by dissolving 0.70 g (3.5 × 10 ⁻³ mol) of copper acetate monohydrate in 35 g of ethanol, and equimolar hexylphosphonic acid 0 with respect to copper acetate monohydrate A solution (b1) in which .58 g and 0.5 g of the following phosphoric ester compound (A) were dissolved in 5 g of ethanol was prepared.

The phosphate ester compound (A) includes a phosphate ester compound (monoester) represented by the general formula (2a) and a phosphate ester compound (diester) represented by the general formula (2b). , A mixture of a triester in which the hydrogen atom of the hydroxyl group in the general formula (2b) is further substituted with the same group, n in the formula is 10, and R ⁵ is a carbon number of 13 to 15 It is an alkyl group. In addition, the abundance ratio (molar ratio) of the monoester, diester and triester in the phosphoric ester compound (A) is 1: 1: 1, and R ⁵ is an alkyl group having 13 to 15 carbon atoms. Is an alkyl group having 14 carbon atoms on average. When calculating the number of moles of the phosphate ester compound (A) and the number of moles of each component in the phosphate ester compound (A), the calculation can be made based on the above values.

  Next, the solution (a1) and the solution (b1) obtained above were mixed and reacted by stirring at room temperature for 2 hours. After the reaction, by-products and the solvent were distilled off from the obtained reaction mixture at 60 ° C. under reduced pressure.

  Then, 3.7 g of styrene was added to the solid content obtained by removing the solvent from the reaction mixture, and redispersion treatment was performed by ultrasonic irradiation to obtain 5 g of a styrene monomer in which a near infrared absorber was dispersed. The average particle diameter of the near-infrared absorber (copper complex) in this dispersion was 125 nm. In addition, the average particle diameter was calculated | required using Otsuka Electronics Co., Ltd. ELSZ-2.

  Styrene monomer in which this near-infrared absorber is dispersed 3.5 g, Phenoxyethyl methacrylate (Light Ester PO, manufactured by Kyoeisha Chemical Co., Ltd.) 2.5 g, Tricyclodecane dimethanol dimethacrylate (NK Ester DCP Shin-Nakamura Chemical Co., Ltd.) ) Made by mixing) 1.0 g, tert-butyl peroxypivalate (perbutyl PV manufactured by Nippon Oil & Fats Co., Ltd.) 0.07 g as a polymerization initiator was added and mixed to obtain near-infrared absorber-containing monomer A1. Obtained.

Next, two glass plates having a diameter of 80 mm and a thickness of 5 mm were arranged to face each other at an interval of 0.54 mm, and the end surfaces of both glass plates were sealed with tape to prepare a glass mold.
Next, the near-infrared absorber-containing monomer A1 was injected into the glass mold.

  The glass mold into which the near-infrared absorber-containing monomer A1 was injected was heated in an oven at 45 ° C. for 8 hours, then heated to 65 ° C. over 4 hours, and then heated to 100 ° C. over 2.5 hours. Thereafter, polymerization was carried out by maintaining at 100 ° C. for 1 hour. After completion of the polymerization, the oven temperature was lowered to 70 ° C. over 2 hours and then removed from the oven, the glass mold was disassembled, and the colorless transparent resin plate (near infrared absorption filter) in the glass mold was taken out.

  The removed resin plate was 0.5 mm thick. The spectral transmittance of the resin plate is shown in FIG. The spectral transmittance was determined using a spectrophotometer U4000 manufactured by Hitachi, Ltd. Moreover, the haze of this near-infrared absorption filter was 0.9. Haze was determined by using a turbidimeter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd. and setting the light source to D65.

[Comparative Example 1]
18.0 g of a mixture of bismethacryloxyethyl phosphate and methacryloxyethyl phosphate (light ester P2M manufactured by Kyoeisha Chemical Co., Ltd.), 8.45 g of 1,6-hexanediol dimethacrylate, 15.36 g of methyl methacrylate Α-methylstyrene 0.35 g and water 0.8 g were mixed to prepare a monomer mixture. To this, 17.74 g of copper benzoate anhydride was added and heated and mixed at 80 ° C. to prepare a monomer mixed solution in which copper ions were dissolved. By cooling the monomer mixture to −20 ° C., benzoic acid precipitated was filtered off to prepare monomer B.

  The same glass mold as in Example 1 was prepared by mixing and stirring 0.17 g of tert-butyl peroxy-2-ethylhexanoate (Perbutyl O Nippon Oil & Fats Co., Ltd.) to 10.0 g of the monomer B thus prepared. And a blue resin plate was obtained by performing polymerization in the same manner as in Example 1.

  The removed resin plate was 0.5 mm thick. The spectral transmittance of the resin plate is shown in FIG. The spectral transmittance was determined using a spectrophotometer U4000 manufactured by Hitachi, Ltd. Moreover, the haze of this near-infrared absorption filter was 0.5. Haze was determined by using a turbidimeter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd. and setting the light source to D65.

[Example 2]
A solution (a2) obtained by dissolving 2.00 g (1.0 × 10 ⁻² mol) of copper acetate monohydrate in 100 g of ethanol, and equimolar butylphosphonic acid 1 with respect to copper acetate monohydrate A solution (b2) prepared by dissolving .38 g and 1.0 g of the phosphoric ester compound (A) in 10 g of ethanol was prepared.

  Next, the solution (a2) obtained above and the solution (b2) were mixed and reacted by stirring at room temperature for 2 hours. After the reaction, by-products and the solvent were distilled off from the obtained reaction mixture at 60 ° C. under reduced pressure.

  Then, 20 g of methylene chloride was added to the solid content obtained by removing the solvent from the reaction mixture, and redispersion treatment was performed by ultrasonic irradiation for 5 hours. Next, 4.0 g of divinylbenzene (a mixture of 55% by mass of reagent divinylbenzene and 45% by mass of ethylstyrene) was added to this dispersion, and methylene chloride was distilled off at room temperature under reduced pressure to disperse the near infrared absorber. 7 g of divinylbenzene was obtained. The average particle diameter of the near-infrared absorber (copper complex) in this dispersion was 58 nm. In addition, the average particle diameter was calculated | required using Otsuka Electronics Co., Ltd. ELSZ-2.

  1.6 g of divinylbenzene in which this near-infrared absorber is dispersed, 4.5 g of phenoxyethyl methacrylate (light ester PO, manufactured by Kyoeisha Chemical Co., Ltd.), 0.4 g of styrene, diethylene glycol dimethacrylate (NK ester 2EG Shin-Nakamura Chemical Co., Ltd.) Co., Ltd.) 0.5 g is mixed, and 0.1 g of tert-butyl peroxypivalate (Perbutyl PV manufactured by Nippon Oil & Fats Co., Ltd.) is added and mixed as a polymerization initiator, and the near-infrared absorber-containing monomer A2 Got.

  The obtained near-infrared absorber-containing monomer A2 was poured into the same glass mold as in Example 1 and polymerized in the same manner as in Example 1 to obtain a colorless and transparent resin plate (near-infrared absorption filter).

  The removed resin plate was 0.5 mm thick. The spectral transmittance of the resin plate is shown in FIG. The spectral transmittance was determined using a spectrophotometer U4000 manufactured by Hitachi, Ltd. Moreover, the haze of this near-infrared light cut filter was 0.1. Haze was determined by using a turbidimeter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd. and setting the light source to D65.

Example 3
A solution (a3) obtained by dissolving 1.56 g (7.8 × 10 ⁻³ mol) of copper acetate monohydrate in 80 g of ethanol, and equimolar octylphosphonic acid 1 with respect to copper acetate monohydrate A solution (b3) in which 0.52 g and 1.0 g of the following phosphoric ester compound (B) were dissolved in 10 g of ethanol was prepared.

The phosphate ester compound (B) is a mixture ratio (molar ratio) of the phosphate ester compound represented by the general formula (2a) and the phosphate ester compound represented by the general formula (2b) (( 2a) :( 2b)) is a 2: 1 mixture. In the phosphoric ester compound (B), n in the formula is 15 and R ⁵ is an alkyl group having 12 carbon atoms. When calculating the number of moles of the phosphate ester compound (B) and the number of moles of each component in the phosphate ester compound (B), the calculation can be made based on the above values.

  Next, the solution (a3) and the solution (b3) obtained above were mixed and reacted by stirring at room temperature for 2 hours. After the reaction, the container was allowed to stand to obtain a precipitate. Therefore, the supernatant solvent was removed, and the by-product and the remaining solvent were distilled off from the remaining reaction mixture at 60 ° C. under reduced pressure.

  Then, 20 g of methylene chloride was added to the solid content obtained by removing the solvent from the reaction mixture, and redispersion treatment was performed by ultrasonic irradiation for 14 hours. Next, 5.0 g of tert-butylstyrene and 3.0 g of styrene were added to this dispersion, and 9.5 g of a styrene monomer in which methylene chloride was distilled off at room temperature under reduced pressure to disperse a near infrared absorber. Obtained. The average particle diameter of the near-infrared absorber (copper complex) in this dispersion was 70 nm. In addition, the average particle diameter was calculated | required using Otsuka Electronics Co., Ltd. ELSZ-2.

  3.1 g of styrene monomer in which this near-infrared absorber is dispersed, 1.7 g of phenoxyethyl methacrylate (light ester PO, manufactured by Kyoeisha Chemical Co., Ltd.), ethylene glycol dimethacrylate (NK ester 2EG, Shin-Nakamura Chemical Co., Ltd.) 0.7 g and 1.5 g of methyl methacrylate are mixed, and 0.1 g of tert-butyl peroxy-2-ethylhexanoate (Perbutyl O Nippon Oil & Fats Co., Ltd.) is added and mixed as a polymerization initiator. A near-infrared absorber-containing monomer A3 was obtained.

  The obtained near-infrared absorber-containing monomer A3 was poured into the same glass mold as in Example 1 and polymerized in the same manner as in Example 1 to obtain a colorless and transparent resin plate (near-infrared absorption filter).

  The removed resin plate was 0.5 mm thick. The spectral transmittance of the resin plate is shown in FIG. The spectral transmittance was determined using a spectrophotometer U4000 manufactured by Hitachi, Ltd. Moreover, the haze of this near-infrared light cut filter was 0.5. Haze was determined by using a turbidimeter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd. and setting the light source to D65.

<Moisture resistance test (reliability test)>
The resin plate obtained in Example 2 and the resin plate obtained in Comparative Example 1 were placed in a constant temperature and humidity chamber maintained at 60 ° C. and 90% relative humidity, respectively, and held for 500 hours.

  The change in haze of the resin plate is shown in FIG. Haze was determined by using a turbidimeter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd. and setting the light source to D65.

Claims (7)

A phosphonic acid compound represented by the following general formula (1):
At least one phosphate ester compound selected from a phosphate ester compound represented by the following general formula (2a) and a phosphate ester compound represented by the following general formula (2b);
A near-infrared absorbing filter formed from a near-infrared absorber and a resin obtained from a copper salt.

[In the formula, R ¹ is a monovalent group represented by ^{_{-CH 2 CH 2 -R 11, R}} 11 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a fluorine having 1 to 20 carbon atoms, Represents an alkyl group. R ²¹ , R ²² and R ²³ are monovalent groups represented by — (CH ₂ CH ₂ O) _n R ⁵ , n is an integer of 4 to 25, and R ⁵ has 6 to 6 carbon atoms. 25 alkyl group or C6-C25 alkylphenyl group is shown. However, R ²¹ , R ²² and R ²³ may be the same or different. ] At least one selected from a phosphonic acid compound represented by the following general formula (1), a phosphoric acid ester compound represented by the following general formula (2a), and a phosphoric acid ester compound represented by the following general formula (2b) A seed phosphate compound and a copper salt are mixed in a solvent to obtain a reaction mixture,
A near-infrared absorber is obtained by removing at least a part of the solvent from the reaction mixture,
The near infrared absorber is dispersed in a monomer to obtain a near infrared absorber-containing monomer,
The near-infrared absorption filter formed from the composition containing the near-infrared absorber and resin obtained by superposing | polymerizing the said near-infrared absorber containing monomer.

[In the formula, R ¹ is a monovalent group represented by ^{_{-CH 2 CH 2 -R 11, R}} 11 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a fluorine having 1 to 20 carbon atoms, Represents an alkyl group. R ²¹ , R ²² and R ²³ are monovalent groups represented by — (CH ₂ CH ₂ O) _n R ⁵ , n is an integer of 4 to 25, and R ⁵ has 6 to 6 carbon atoms. 25 alkyl group or C6-C25 alkylphenyl group is shown. However, R ²¹ , R ²² and R ²³ may be the same or different. ] At least one selected from a phosphonic acid compound represented by the following general formula (1), a phosphoric acid ester compound represented by the following general formula (2a), and a phosphoric acid ester compound represented by the following general formula (2b) A seed phosphate compound and a copper salt are mixed in a solvent to obtain a reaction mixture,
A near-infrared absorber is obtained by removing at least a part of the solvent from the reaction mixture,
A dispersion is obtained by dispersing the near-infrared absorber in a low boiling point solvent,
After adding the monomer to the dispersion, by removing at least a part of the low boiling point solvent, obtaining a near-infrared absorber-containing monomer,
The near-infrared absorption filter formed from the composition containing the near-infrared absorber and resin obtained by superposing | polymerizing the said near-infrared absorber containing monomer.

[In the formula, R ¹ is a monovalent group represented by ^{_{-CH 2 CH 2 -R 11, R}} 11 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a fluorine having 1 to 20 carbon atoms, Represents an alkyl group. R ²¹ , R ²² and R ²³ are monovalent groups represented by — (CH ₂ CH ₂ O) _n R ⁵ , n is an integer of 4 to 25, and R ⁵ has 6 to 6 carbon atoms. 25 alkyl group or C6-C25 alkylphenyl group is shown. However, R ²¹ , R ²² and R ²³ may be the same or different. ]   The resin has a structural unit derived from at least one monomer selected from a monofunctional aromatic vinyl compound, a polyfunctional aromatic vinyl compound, a monofunctional (meth) acrylic acid ester, and a polyfunctional (meth) acrylic acid ester. The near-infrared absorption filter as described in any one of Claims 1-3.   The near-infrared absorption filter according to claim 4, wherein at least a part of the monomer is at least one monomer selected from a polyfunctional (meth) acrylic acid ester and a polyfunctional aromatic vinyl compound. At least one selected from a phosphonic acid compound represented by the following general formula (1), a phosphoric acid ester compound represented by the following general formula (2a), and a phosphoric acid ester compound represented by the following general formula (2b) A step of mixing a seed phosphate compound and a copper salt in a solvent to obtain a reaction mixture;
Obtaining a near-infrared absorber by removing at least part of the solvent from the reaction mixture;
Dispersing the near-infrared absorber in a monomer to obtain a near-infrared absorber-containing monomer;
The manufacturing method of the near-infrared absorption filter which has the process of polymerizing the said near-infrared absorber containing monomer and obtaining the composition containing a near-infrared absorber and resin.

[In the formula, R ¹ is a monovalent group represented by ^{_{-CH 2 CH 2 -R 11, R}} 11 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a fluorine having 1 to 20 carbon atoms, Represents an alkyl group. R ²¹ , R ²² and R ²³ are monovalent groups represented by — (CH ₂ CH ₂ O) _n R ⁵ , n is an integer of 4 to 25, and R ⁵ has 6 to 6 carbon atoms. 25 alkyl group or C6-C25 alkylphenyl group is shown. However, R ²¹ , R ²² and R ²³ may be the same or different. ] At least one selected from a phosphonic acid compound represented by the following general formula (1), a phosphoric acid ester compound represented by the following general formula (2a), and a phosphoric acid ester compound represented by the following general formula (2b) A step of mixing a seed phosphate compound and a copper salt in a solvent to obtain a reaction mixture;
Obtaining a near-infrared absorber by removing at least part of the solvent from the reaction mixture;
A step of obtaining a dispersion by dispersing the near-infrared absorber in a low boiling point solvent;
A step of obtaining a near-infrared absorber-containing monomer by removing at least a part of the low-boiling solvent after adding the monomer to the dispersion;
The manufacturing method of the near-infrared absorption filter which has the process of polymerizing the said near-infrared absorber containing monomer and obtaining the composition containing a near-infrared absorber and resin.

[In the formula, R ¹ is a monovalent group represented by ^{_{-CH 2 CH 2 -R 11, R}} 11 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a fluorine having 1 to 20 carbon atoms, Represents an alkyl group. R ²¹ , R ²² and R ²³ are monovalent groups represented by — (CH ₂ CH ₂ O) _n R ⁵ , n is an integer of 4 to 25, and R ⁵ has 6 to 6 carbon atoms. 25 alkyl group or C6-C25 alkylphenyl group is shown. However, R ²¹ , R ²² and R ²³ may be the same or different. ]

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