JP2023068643A - Diimmonium compound and use thereof - Google Patents

Abstract

To provide diimonium compounds with high heat resistance, and resin compositions containing the same.SOLUTION: The invention provides diimonium compounds represented by the general formula (1) in the figure, and resin compositions and near-infrared cut filters obtained using the diimonium compounds. (In the formula (1), at least one of R1 to R8 is a methyl group.)SELECTED DRAWING: None

Description

The present invention relates to a dimonium compound having absorption in the infrared region and its use, and in particular, a near-infrared cut filter obtained by laminating a resin layer of a diimonium compound having excellent heat resistance and a thermosetting resin composition containing it ( optical filters).

Image pickup devices such as CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor) used in digital cameras have spectral sensitivity ranging from the visible region to the near-infrared region around 1100 nm. Human eyes can perceive light with wavelengths around 400 to 700 nm. Therefore, since there is a large difference in spectral sensitivity between the image sensor and the human eye, it is necessary to equip the front surface of the image sensor with a near-infrared cut filter that absorbs light in the near-infrared region to correct the visibility of the human eye. is.

A glass filter obtained by adding CuO to phosphate glass is known as a near-infrared cut filter used in an imaging device. However, this near-infrared absorbing glass is very expensive. In addition, since it is glass, there is a problem with workability, the degree of freedom in designing optical characteristics is narrow, and it is complicated to deal with spherical surfaces. Furthermore, there is a limit to how thin the thickness of the glass can be, and there are problems in securing space and weight reduction when incorporating it into an imaging optical system.

Therefore, technology has been developed to produce a near-infrared cut filter that can be formed into a thin film or a spherical surface by coating a resin composition containing a near-infrared absorbing dye on the surface of an image sensor or a filter base material. ing. As near-infrared absorption dyes, specifically, diimmonium compound dyes, chromone-type squarylium compound dyes, phthalocyanine compound dyes, naphthalene compound dyes, and the like are known.

Diimmonium compounds are known to change their physical properties such as heat resistance, resistance to moist heat, solubility in solvents, and dispersibility in resin substrates by changing the chemical structure of the terminal group of the cation moiety and the anion moiety. ing. However, conventionally known diimmonium compounds have insufficient heat resistance and can be thermally deteriorated when mixed with a resin composition and processed and molded. It is a bottleneck for miniaturization and lightness.
Against this background, in recent years, there has been a strong demand for the development of a dimonium compound that has a wide near-infrared absorption wavelength range and excellent heat resistance, a near-infrared cut filter using the same, and a resin composition for producing it. there is

Patent Document 1 discloses a diimonium salt compound, which is a salt composed of a diimonium cation and two tetrakis(pentafluorophenyl)boron anions, as a diimonium compound having near-infrared absorption ability.

JP 2007-246464 A

An object of the present invention is to provide a diimmonium compound having high heat resistance and a resin composition containing the same. Another object of the present invention is to provide a near-infrared cut filter having a wide range of near-infrared absorbing power and high heat resistance, which is produced using the same.

As a result of extensive studies, the present inventors have found that a diimmonium compound having a specific chemical structure described later has extremely excellent heat resistance, and by laminating a resin layer obtained from a thermosetting resin composition containing the diimmonium compound, The inventors have found that it contributes to the production of a near-infrared cut filter that solves the above problems, and completed the present invention.

That is, the present invention provides the following (a) to (f).

(a): Diimmonium compounds represented by the following formula (1).

In formula (1), at least one of R ₁ to R ₈ is a methyl group.

(b): The diimmonium compound according to (a), wherein R ₁ to R ₈ in formula (1) are methyl groups.

(c): A resin composition characterized by containing the diimmonium compound described in (a) or (b) above.

(2): The resin composition according to (3), which further contains polycarbonate.

(E): A near-infrared cut filter comprising at least a laminate of resin layers containing the diimmonium compound described in (A) or (B) above.

(f): The diimmonium compound according to (a), which has a melting point of 250° C. or higher.

The diimmonium compound of the present invention has excellent heat resistance as a near-infrared absorbing dye, does not deteriorate in near-infrared absorbing ability over a long period of time, and has excellent dispersibility and workability with a resin substrate, and has a wide range of near-infrared absorbing ability. is characterized by having Moreover, since the compound itself does not contain heavy metals, there is no environmental problem.

Therefore, the resin composition containing the diimmonium compound of the present invention as a near-infrared absorbing dye can be suitably used for optical filters (near-infrared cut filters) used in imaging devices.

The dimonium compound of the present invention is a compound represented by the following general formula (1).

In formula (1), at least one of R ₁ to R ₈ is a methyl group. Among these, those in which all of R ₁ to R ₈ in formula (1) are methyl groups are more preferable from the viewpoint of heat resistance and near-infrared absorption capability.

The diimmonium compound represented by Formula (1) of the present invention can be obtained by a known method. That is, the following formula (2) obtained by reducing the product obtained by the Ullmann reaction of p-phenylenediamine and 1-chloro-4-nitrobenzene,

in an organic solvent, preferably in a water-soluble polar solvent such as DMF (dimethylformamide), DMI (dimethylimidazolinone) or NMP (N-methylpyrrolidone), at 30 to 160 ° C., preferably at 50 to 140 ° C., with a halogenated compound corresponding to the desired R ₁ to R ₈ (eg, CH ₃ Br when R ₁ to R ₈ are methyl groups) to remove all substituents (R ₁ to R ₈ ). are the same (hereinafter referred to as a fully substituted compound) of the following formula (3).

As a method for synthesizing the diimmonium compound of the present invention, after preparing the diimmonium compound by a known method, the anion portion thereof may be replaced with tetrakis(pentafluorophenyl)boric acid.

More specifically, for example, tetrakis(pentafluorophenyl)boric acid prepared according to the method described in International Publication WO2006/082945 is used as an anion component, and silver is allowed to act thereon to produce tetrakis(pentafluorophenyl)boric acid. Silver and the imonium compound represented by the general formula (3) are treated in an organic solvent such as N-methyl-2-pyrrolidone, dimethylformamide (hereinafter abbreviated as "DMF"), acetonitrile, etc. at a temperature of 30 to 150°C. and after filtering off the precipitated silver, a solvent such as water, ethyl acetate or hexane is added, and the resulting precipitate is filtered to obtain the diimmonium compound of the present invention.

The diimmonium salt compound of the present invention thus obtained is useful as a near-infrared absorbing dye. It is possible to produce a resin composition having

Among these methods, the casting method involves dissolving or dispersing the diimmonium compound (near-infrared absorbing dye) of the present invention in a solution in which a polymer resin and a solvent are mixed, and then forming a transparent film, panel, or film such as polyester or polycarbonate. In this method, the solution is applied onto a glass substrate and dried to form a film.

As the resin, a transparent resin is used, and examples thereof include acrylic resins, polyester resins, polycarbonates, urethane resins, cellulose resins, polyisocyanates, polyarylates, and epoxy resins.

The solvent is not particularly limited as long as it can dissolve the resin. Examples include organic solvents such as methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, tetrahydrofuran, and 1,4-dioxane, or mixtures thereof. Any solvent can be used.

On the other hand, in the melt extrusion method, the dimonium compound of the present invention is melted and kneaded in a polymer resin, and then extruded into a panel shape. Since the dimonium compound of the present invention has high heat resistance, it can be melted and kneaded at high temperatures.

As the resin, a transparent resin is used, and examples thereof include acrylic resins, polyester resins, and polycarbonate.

The diimmonium compound of the present invention can be used alone as a near-infrared absorbing dye, or can be used by adding a known dye such as phthalocyanines or a dithiol-based metal complex to supplement near-infrared blocking performance at a wavelength of around 850 nm. can be done. Moreover, in order to improve the light resistance, a benzophenone-based or benzotriazole-based ultraviolet absorbing dye may be added and used. Furthermore, if necessary, a known dye having absorption in the visible light region may be added to adjust the color tone.

In the present invention, the melting point of the diimmonium compound is measured using a thermogravimetric-differential thermal analyzer (TG-DTA) (for example, an apparatus according to NEXTA STA300 (manufactured by Hitachi High-Tech Science)), and the diimonium compound is placed in an aluminum open pan. 5 mg was weighed and the melting peak was recorded when the temperature of the diimmonium compound was increased at a rate of 10°C/min.

The near-infrared cut filter (optical filter) of the present invention may be provided on a substrate or may be the substrate itself. The base material is not particularly limited as long as it can be used in general optical filters, but a base material made of glass or resin is usually used. The thickness of the layer is usually about 0.05 μm to 10 mm, but it is appropriately determined according to the purpose such as near-infrared cut rate. Also, an imaging element such as a CCD or CMOS may be used as the base material.

The content of the near-infrared absorbing dye used in the near-infrared cut filter of the present invention is also appropriately determined according to the desired near-infrared cut rate. Examples of resin substrates to be used include polyethylene, polycycloalkane, polycycloolefin, polystyrene, polyacrylic acid, polyacrylic acid ester, polyvinyl acetate, polyacrylonitrile, polyvinyl chloride, polyvinyl fluoride, and other vinyls. compounds, and addition polymers of their vinyl compounds, polymethacrylic acid, polymethacrylic acid esters, polyvinylidene chloride, polyvinylidene fluoride, polyvinylidene cyanide, vinylidene fluoride/trifluoroethylene copolymer, vinylidene fluoride/tetrafluoro Ethylene copolymers, vinyl compounds such as vinylidene cyanide/vinyl acetate copolymers or copolymers of fluorine compounds, resins containing fluorine such as polytrifluoroethylene, polytetrafluoroethylene, polyhexafluoropropylene, etc., nylon 6 , polyamides such as nylon 66, polyimides, polyurethanes, polypeptides, polyesters such as polyethylene terephthalate, polycarbonates, polyethers such as polyoxymethylene, epoxy resins, polyvinyl alcohol and polyvinyl butyral.

The method for producing the near-infrared cut filter (optical filter) of the present invention is not particularly limited, and a method known per se can be used. A method of producing a resin plate or film by forming a thermosetting resin composition, molding and then heat curing to produce a resin plate or film, 2) preparing a paint containing a near-infrared absorbing dye, forming a resin composition, forming a transparent resin plate, 3) A method of coating a transparent film, a transparent glass plate, or an imaging device; a method of making a plate, a laminated resin film, or a laminated glass plate;

In the method of 1), a thermosetting resin composition consisting of a thermosetting resin, a curing agent, and a near-infrared absorbing dye is prepared, injected into a mold, and cured by heat reaction, or poured into a mold. A method of molding by heating and reacting in a mold until it becomes a hard product can be mentioned. Although the processing temperature, film forming (resin board forming) conditions and the like differ slightly depending on the composition used, curing conditions of about 100 to 200° C. for about 30 minutes to 5 hours are usually applied. The amount of the near-infrared absorbing dye added varies depending on the thickness, absorption intensity, visible light transmittance, etc. of the resin plate or film to be produced, but is usually about 0.01 to 30% by mass with respect to 1 part by mass of the base resin. , preferably about 0.01 to 15% by mass.

Method 2) is a method of dissolving or dispersing a near-infrared absorbing colorant in a binder resin to form a paint, and a solvent can also be used when forming the paint. As the solvent, a halogen compound, an alcohol compound, a ketone compound, an ester compound, an aliphatic hydrocarbon compound, an aromatic hydrocarbon compound, an ether compound, or a mixture thereof can be used as a solvent. The concentration of the near-infrared absorbing dye varies depending on the thickness, absorption intensity, and visible light transmittance of the coating to be produced, but is usually about 0.01 to 30% by mass with respect to 1 part by mass of the binder resin. The paint thus obtained is coated on a transparent resin plate, transparent film, transparent glass plate, imaging device, or the like using a spin coater, bar coater, roll coater, gravure coater, offset coater, spray, or the like, and near-infrared rays are emitted. It is possible to obtain a cut filter or an imaging device equipped with it.

In the method 3), near-infrared rays are applied to known transparent adhesives for laminated glass such as polyvinyl butyral adhesives and ethylene-vinyl acetate adhesives for resin compounds such as silicon, urethane, and acrylic. Using a thermosetting resin composition to which about 0.1 to 30% by mass of absorbing dye is added, transparent resin plates, resin plate and resin film, resin plate and glass, resin film and resin film, glass and glass A near-infrared cut filter is produced by bonding. Incidentally, during kneading and mixing in each method, ordinary additives used in resin molding such as ultraviolet absorbers and plasticizers may be added.

EXAMPLES The present invention will be described in more detail below using Examples, but the present invention is not limited to these Examples. In the examples, "% by mass" is simply abbreviated as "%", and "parts by weight" is simply abbreviated as "parts".

Example 1
(1) To 100 parts of DMF, 31.9 parts of silver tetrakis(pentafluorophenyl)borate and 11.8 parts of N,N,N',N'-tetrakis(p-dimethylaminophenyl)-p-phenylenediamine are added. , and 60° C. for 3 hours, and the produced silver was filtered off. Next, 315 parts of water is added to the filtrate, and the formed precipitate is filtered and dried to give N,N,N',N'-tetrakis(p-dimethylaminophenyl)-tetrakis(pentafluorophenyl)borate. 33.3 parts of p-phenylenediimonium are obtained. This was a near-infrared absorbing dye, and had a maximum absorption wavelength (hereinafter abbreviated as "λmax") of 1046 nm and a molar extinction coefficient of 93000 [L·mol ⁻¹ ·cm ⁻¹ ].
(2) Heat resistance was evaluated when the dye obtained was heated at temperatures of 190°C, 210°C and 230°C. Specifically, the pigment powder was dissolved in acetone to prepare a solution adjusted to a concentration of 10 to 20 mg/L. This solution was measured with a spectrophotometer to measure the initial (before heating) molar extinction coefficient at a wavelength of 1000 nm.
After the dye powder was allowed to stand at each temperature for 60 minutes, the molar extinction coefficient of the solution prepared in the same manner was measured, and the percentage of the molar extinction coefficient after heating to the initial molar extinction coefficient (before heating) was calculated. evaluated as a rate. The results are shown in Table 1.

Comparative example 1
20.3 parts of silver tetrakis(pentafluorophenyl)borate and 11.8 parts of N,N,N',N'-tetrakis(p-diisobutylaminophenyl)-p-phenylenediamine were added to 100 parts of DMF, and the temperature was 60°C. for 3 hours, and the silver produced was filtered off. Next, 200 parts of water is added to the filtrate, and the formed precipitate is filtered and dried to give N,N,N',N'-tetrakis(p-diisobutylaminophenyl)-tetrakis(pentafluorophenyl)borate. 24.8 parts of p-phenylenediimonium were obtained. This was a near-infrared absorbing dye, and had a maximum absorption wavelength (hereinafter abbreviated as "λmax") of 1077 nm and a molar extinction coefficient of 105000 [L·mol ⁻¹ ·cm ⁻¹ ].
The dye obtained was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative example 2
To 157.5 parts of DMF, 15.7 parts of silver bis(trifluoromethanesulfone)imidate and 11.8 parts of N,N,N',N'-tetrakis(p-dimethylaminophenyl)-p-phenylenediamine are added, The reaction was carried out at 60° C. for 3 hours, and the produced silver was separated by filtration. Next, 315 parts of water is added to the filtrate, and the formed precipitate is filtered and dried to obtain bis(trifluoromethanesulfone)imidic acid N,N,N',N'-tetrakis(p-dimethylaminophenyl)- 19.2 parts of p-phenylenediimonium are obtained. This was a near-infrared absorbing dye, and had a maximum absorption wavelength (hereinafter abbreviated as "λmax") of 1046 nm and a molar extinction coefficient of 93000 [L·mol ⁻¹ ·cm ⁻¹ ].
The dye obtained was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative example 3
10 parts of silver bis(trifluoromethanesulfone)imidate and 11.8 parts of N,N,N',N'-tetrakis(p-diisobutylaminophenyl)-p-phenylenediamine were added to 100 parts of DMF, and the mixture was stirred at 60°C for 3 hours. After reacting for some time, the silver produced was separated by filtration. Next, 200 parts of water is added to the filtrate, and the formed precipitate is filtered and dried to obtain bis(trifluoromethanesulfone)imidic acid N,N,N',N'-tetrakis(p-diisobutylaminophenyl)- 15.7 parts of p-phenylenediimonium are obtained. This was a near-infrared absorbing dye, and had a maximum absorption wavelength (hereinafter abbreviated as "λmax") of 1077 nm and a molar extinction coefficient of 105000 [L·mol ⁻¹ ·cm ⁻¹ ].
The dye obtained was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative example 4
20.3 parts of silver tetrakis(pentafluorophenyl)borate and 11.8 parts of N,N,N',N'-tetrakis(p-dibutylaminophenyl)-p-phenylenediamine were added to 100 parts of DMF, and the temperature was 60°C. for 3 hours, and the silver produced was filtered off. Next, 200 parts of water is added to the filtrate, and the formed precipitate is filtered and dried to give N,N,N',N'-tetrakis(p-dibutylaminophenyl)-tetrakis(pentafluorophenyl)borate. 24.8 parts of p-phenylenediimonium were obtained. This was a near-infrared absorbing dye, and had a maximum absorption wavelength (hereinafter abbreviated as "λmax") of 1072 nm and a molar extinction coefficient of 102000 [L·mol ⁻¹ ·cm ⁻¹ ].
The heat resistance of the obtained dye was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative example 5
10 parts of silver bis(trifluoromethanesulfone)imidate and 11.8 parts of N,N,N',N'-tetrakis(p-dibutylaminophenyl)-p-phenylenediamine were added to 100 parts of DMF, and the mixture was stirred at 60°C for 3 hours. After reacting for some time, the silver produced was separated by filtration. Then, 200 parts of water is added to the filtrate, and the formed precipitate is filtered and dried to obtain bis(trifluoromethanesulfone)imidic acid N,N,N',N'-tetrakis(p-dibutylaminophenyl)- 15.7 parts of p-phenylenediimonium are obtained. This was a near-infrared absorbing dye, and had a maximum absorption wavelength (hereinafter abbreviated as "λmax") of 1072 nm and a molar extinction coefficient of 102000 [L·mol ⁻¹ ·cm ⁻¹ ].
The heat resistance of the obtained dye was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative example 6
26.8 parts of silver tetrakis(pentafluorophenyl)borate and 11.8 parts of N,N,N',N'-tetrakis(p-diethylaminophenyl)-p-phenylenediamine were added to 132 parts of DMF, and the mixture was stirred at 60°C. After reacting for 3 hours, the produced silver was separated by filtration. Next, 264 parts of water is added to the filtrate, and the formed precipitate is filtered and dried to give N,N,N',N'-tetrakis(p-diethylaminophenyl)-p tetrakis(pentafluorophenyl)borate. - 29.6 parts of phenylenediimonium are obtained. This was a near-infrared absorbing dye, and had a maximum absorption wavelength (hereinafter abbreviated as "λmax") of 1057 nm and a molar extinction coefficient of 99700 [L·mol ⁻¹ ·cm ⁻¹ ].
The heat resistance of the obtained dye was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative example 7
To 132 parts of DMF, 13.2 parts of silver bis(trifluoromethanesulfone)imidate and 11.8 parts of N,N,N',N'-tetrakis(p-diethylaminophenyl)-p-phenylenediamine were added, and the mixture was stirred at 60°C. After reacting for 3 hours, the produced silver was separated by filtration. Then, 264 parts of water is added to the filtrate, and the formed precipitate is filtered and dried to obtain bis(trifluoromethanesulfone)imidic acid N,N,N',N'-tetrakis(p-diethylaminophenyl)-p. - 17.7 parts of phenylenediimonium are obtained. This was a near-infrared absorbing dye, and had a maximum absorption wavelength (hereinafter abbreviated as "λmax") of 1057 nm and a molar extinction coefficient of 99700 [L·mol ⁻¹ ·cm ⁻¹ ].
The heat resistance of the obtained dye was evaluated in the same manner as in Example 1. The results are shown in Table 1.

In Table 1, "cationic terminal group" indicates that R ₁ to R ₈ in formula (1) are corresponding terminal groups, "TEPB" indicates a tetrakis(pentafluorophenyl)boron anion, and "TFSI" denotes the bis(trifluoromethanesulfonyl)imide anion.

As described above, the diimmonium compounds of the examples of the present invention have high heat resistance.

Example 2
0.5 parts of the dimonium compound obtained in Example 1 and 99.5 parts of a polycarbonate resin (Panlite L-1250Y, manufactured by Teijin Limited) were mixed with a twin-screw kneader (Laboplastomill, manufactured by Toyo Seiki Seisakusho Co., Ltd.). ) and melt-kneaded at a temperature of 260° C. to obtain a resin composition part. The obtained resin composition was pressed at a temperature of 230° C. using a hot press to obtain an infrared cut filter with a thickness of 0.25 mm.

Comparative example 8
An infrared cut filter was obtained in the same manner as in Example 2, except that the dimonium compound of Example 1 was replaced with Comparative Example 1.

Comparative example 9
An infrared cut filter was obtained in the same manner as in Example 2, except that the dimonium compound of Example 1 was replaced with Comparative Example 2.

Comparative example 10
An infrared cut filter was obtained in the same manner as in Example 2 except that the dimonium compound of Example 1 was replaced with Comparative Example 3.

Comparative example 11
An infrared cut filter was obtained in the same manner as in Example 2, except that the dimonium compound of Example 1 was replaced with Comparative Example 4.

Comparative example 12
An infrared cut filter was obtained in the same manner as in Example 2 except that the dimonium compound of Example 1 was replaced with Comparative Example 5.

Comparative example 13
An infrared cut filter was obtained in the same manner as in Example 2 except that the dimonium compound of Example 1 was replaced with Comparative Example 6.

Comparative example 14
An infrared cut filter was obtained in the same manner as in Example 2, except that the dimonium compound of Example 1 was replaced with Comparative Example 7.

Table 2 shows the results of measuring the transmittance of the obtained infrared cut filter at wavelengths of 1000 nm and 500 nm with a spectrophotometer.

In Table 2, "cationic terminal group" indicates that R ₁ to R ₈ in formula (1) are the corresponding terminal groups, "TEPB" indicates a tetrakis(pentafluorophenyl)boron anion, and "TFSI" denotes the bis(trifluoromethanesulfonyl)imide anion.

As described above, the near-infrared cut filter of the example of the present invention has a wide range of near-infrared absorbing power and high heat resistance.

The resin composition having a near-infrared absorbing ability containing the dimonium compound of the present invention can be used in various applications, and is suitable for, for example, a near-infrared blocking filter for PDP, a near-infrared blocking filter for automobile glass or building glass, and the like. can be used. Furthermore, the near-infrared absorbing dye of the present invention can also be used as a dye or quencher for conventional optical recording media such as CD-R and DVD-R.

The near-infrared cut filter of the present invention can be used not only for imaging devices and front panels of displays, but also for filter films that need to cut near-infrared rays, such as heat-insulating films, optical products, and sunglasses.

Claims (6)

A dimonium compound represented by the following formula (1).

(In Formula (1), at least one of R ₁ to R ₈ is a methyl group.) 2. The diimmonium compound according to claim 1, wherein R ₁ to R ₈ in formula (1) are methyl groups. A resin composition comprising the diimmonium compound according to claim 1 or 2. 4. The resin composition according to claim 3, further comprising polycarbonate. A near-infrared cut filter comprising at least a laminate of resin layers containing the diimmonium compound according to claim 1 or 2. The diimmonium compound according to claim 1, which has a melting point of 250°C or higher.