KR20110062228A - Near infrared-absorbing compound of high solubility and excellent durability, and near infrared-absorbing material comprising the same - Google Patents

Abstract

PURPOSE: A dithiol nickel complex compound which absorbs near infrared ray of long wave length is provided to ensure high permeability of visible light, durability, and solubility. CONSTITUTION: A dithiol nickel complex compound of chemical formula 1 absorbs near infrared ray of long wavelength. A near infrared ray-absorbing material contains 10-70 weight% of dithiol nickel complex compound of chemical formula 1, 20-80 weight% of binder resin, and 20-70 weight% of solvent. The laminate contains the dithiol nickel complex compound. An optical filter contains the near infrared ray-absorbing laminate.

Description

Near Infrared-Absorbing Compound of High Solubility and Excellent Durability, and Near Infrared-Absorbing Material Comprising the Same}

The present invention relates to a near-infrared absorbing compound having a high solubility and high durability, and a near-infrared absorbing material including the same. More particularly, the present invention effectively absorbs the long-wavelength near-infrared region of 880 to 1000 nm and has excellent durability. The present invention relates to a near-infrared absorbing compound having a novel structure having excellent solubility in various organic solvents and compatibility with various resins, and a near-infrared absorbing material using the same.

In general, near-infrared absorbing filters made of resin or plastic containing near-infrared absorbing pigments are well known, and their use includes sunglasses, welding glasses, windows of buildings and automobiles, train airplanes, and optical reading devices for reading information. Etc. can be mentioned.

This near-infrared absorption filter is also used in plasma display panels (hereinafter, abbreviated as 'PDP'), which are recently used as flat panel display panels. Specifically, since the near infrared rays in the 800 ~ 1500 nm region can be emitted from the PDP, a malfunction of the device using the remote controller can be caused, and the near infrared absorption filter is installed in the PDP to solve this problem.

Such near-infrared absorbing dyes include dimonium-based compounds, phthalocyanine-based compounds, naphthophthalocyanine-based compounds, cyanine-based compounds, anthraquinone-based compounds, and dithiol-based metal complex compounds, but in practice, dimonium-based compounds and phthalocyanine-based compounds Only a part of the compound and the dithiol compound are used.

When the dimonium compound is contained in the same resin layer as a complex compound dye, there is a problem in that it becomes deteriorated and becomes yellow in absorption around 400 to 450 nm. In addition, the phthalocyanine compound is excellent in durability, but the use of an optical filter is limited in that the visible light transmittance is low.

Meanwhile, among the dithiol-based metal complex compounds, the dithiol nickel complex compound has advantages such as relatively easy to manufacture and good durability. For example, long-wavelength (max = 920 or more) dithiol nickel complex compounds such as the following formulas (a) and (b) are known.

(a)

(a)

(b)

(b)

However, although the dithiol nickel complex compounds as described above are excellent in terms of wavelength and durability, they have a low solubility, so that the use of the dithiol nickel complex compounds precipitates at the limit of the amount used when producing the film for blocking the near infrared rays by mixing with a binder resin.

As a result, the near-infrared absorption filter known in the art has a problem that it turns yellow by long-term use, or has low solubility in a solvent and low transmittance of visible light.

Therefore, there is a high demand for a near infrared absorbing filter based on a new near infrared absorbing compound that can fundamentally solve such problems.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems of the prior art and the technical problems required from the past.

Specifically, the inventors of the present application after extensive research and various experiments, the compound of the new structure as described later effectively absorbs long-wave near-infrared rays and has excellent durability, while excellent solubility and compatibility with the resin. It was confirmed that the present invention was completed.

Accordingly, the present invention provides a dithiol nickel complex compound, which is a near-infrared absorbing compound represented by the following formula (1) that absorbs near-infrared wavelengths of long wavelengths.

(1)

(One)

Where

m, m ', n and n' are each independently integers of 0 to 4, at least one of which is an integer of 1 to 4;

x, x ', y and y' are each independently integers from 1 to 4;

R ₁ , R ₁ ′, R ₂ and R ₂ ′ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted aryl group.

In other words, the dithiol nickel complex compound of the present invention exhibits a maximum absorption wavelength in the 880 to 1000 nm region, absorbs long wavelength near infrared rays effectively, and has a small yellow change even after long-term use, and is excellent in compatibility with the resin. In addition, the compound is easy to manufacture, has excellent durability, and is particularly useful as a near-infrared absorbing material because it is superior in solubility to conventional dithiol-based nickel complex compounds.

In Formula 1, m, m ', n and n' are preferably each independently an integer of 0 to 2.

In one preferred example, x and x 'are the same integer as each other, and y and y' can also be the same integer as each other. More preferably, at least one of the combination of x and x 'or the combination of y and y' is an integer from 1 to 4, particularly preferably 1 or 2, respectively.

The substituted or unsubstituted alkyl group is preferably a substituted or unsubstituted C ₁ -C ₅ alkyl group, and the substituted or unsubstituted alkoxy group is preferably a substituted or unsubstituted C ₁ -C ₅ alkoxy group, and the substitution Or an unsubstituted aryl group is preferably a substituted or unsubstituted C ₄ -C ₈ aryl group. When the alkyl group, the alkoxy group and the aryl group have a substituted structure, preferably, the structure may be substituted with one or more substituents selected from the group consisting of a hydroxy group, a halogen group and an amine group.

In one preferred example, R ₁ , R ₁ ′, R ₂ and R ₂ ′ may be hydrogen atoms or C ₁ -C ₅ alkoxy groups.

Specifically, it may be a compound selected from compounds 1 to 9 of Table 1 below.

TABLE 1

Among the compounds 1 to 9, in particular, compounds 2 to 4 are more preferable because they show much higher solubility than other compounds, as can be confirmed in Experimental Example 4 later.

The dithiol nickel complex compounds according to the present invention can be prepared by various methods, for example, G, N Schrauzer et al., J. Amer. Chem. Soc., 87, 1483 (1965) or It can synthesize | combine according to the manufacturing method etc. of the bis (1, 2- diaryl- 1, 2-ethylene dithiolate) nickel complex compound disclosed by Unexamined-Japanese-Patent No. 1990-264787.

Based on this, the method for synthesizing some dithiol nickel complex compounds of the present invention will be described below, of course, other manufacturing methods may be possible.

The present invention also provides a near-infrared absorbing material comprising the dithiol nickel complex compound of the formula (1).

As described above, the dithiol-based nickel complex compound of Formula 1 has excellent solubility and compatibility with resins, so that the dithiol-based nickel complex compound may be added to a solvent, a resin, or the like at a high concentration, thereby producing a material having a near infrared absorption effect superior to that of the prior art. Do.

The solvent may be a solvent to be removed after being used in a predetermined process in the preparation of the near infrared absorbing material, a solvent finally included in the near infrared absorbing material, and examples thereof include methyl ethyl ketone (MEK), toluene, and methyl cellosolve. Although these etc. are mentioned, it is not limited only to these.

The resin may be a resin constituting the matrix of the near infrared absorbing material, a resin constituting the matrix of the near infrared absorbing material, and the latter may be a resin used as a binder. As such a binder, an adhesive resin may be used, and examples thereof include polymethyl methacrylate resin, polyethyl acrylate resin, polycarbonate resin, ethylene-vinyl alcohol copolymer resin, polyester resin, and the like. It is not limited only.

In one preferred embodiment, the near-infrared absorbing material is a composition comprising 10 to 70% by weight of the dithiol-based nickel complex compound of Formula 1, 20 to 80% by weight of the binder resin, and 20 to 70% by weight of the solvent based on the total weight Can be done. When the compound of Formula 1 is dispersed in a solvent, a dispersant may be further included.

In some cases, the near-infrared absorbing material may further include a compound having an absorption wavelength different from that of the near-infrared absorbing compound of Chemical Formula 1.

The near-infrared absorbing compound of Formula 1 may be used alone or in combination of two or more.

In addition, the present invention provides a laminate comprising a layer containing the dithiol nickel complex compound of the formula (1).

For example, as described above, a near-infrared absorbing material including a dithiol nickel complex compound of Formula 1, a binder and a solvent is applied to a predetermined substrate to a predetermined thickness, and then the solvent is removed to prepare a laminate for absorbing near-infrared rays. can do.

Although the said base material can mention glass, transparent resin, a transparent resin board, etc., for example, it is not limited only to these.

In one preferred example, the near-infrared absorbing laminate may be a coating film in which the dithiol nickel complex compound of Formula 1 is coated on one or both sides of the transparent film.

The present invention also provides an optical filter comprising the laminate for absorbing near infrared rays.

Such an optical filter can be used for a wide range of applications, such as a display panel filter, a heat shield film, sunglasses, protective glasses, a remote control receiver.

Although the content of the present invention will be described with reference to the following Examples, the scope of the present invention is not limited thereto.

Example 1 (Bis [1- (3,4,5-trimethoxy) phenyl) -2- [3-methoxy-4- (2-ethoxymethoxy) -phenyl]]-1,2-ethenedithiolato- (2) - Synthesis of S, S '] Nickel Complex Compound (Compound 1)

(One) Synthesis of 3-methoxy-4- (2-ethoxymethoxy) benzaldehyde

To 2000 ml 4-neck RBF, 39.4 g of Vanillin (Acros), 157 g of DMF, 92.8 g of 2-chloro ethyl methyl ether (Aldrich) and 75.2 g of sodium carbonate were sequentially added. The reaction was carried out by reflux cooling for 8 hours to proceed with the reaction. After the reaction was completed, the reaction mixture was cooled and the reaction solution was filtered to remove solids.

The collected filtrates were extracted with Methylene chloride / H ₂ O, concentrated in vacuo to remove the solvent, and cooled to room temperature to recrystallize. The precipitated crystals were filtered and dried to obtain the title compound as a transparent crystal having a purity of 99.0% and a yield of 90%.

(2) Synthesis of (3-methoxy-4- (2-ethoxymethoxy) -3 ', 4', 5'-trimethoxy benzoin)

10 g of 3,4,5-trimethoxy benzaldehyde (TCI) was added to 1000 ml 4-neck RBF, 10.7 g of 3-methoxy-4- (2-ethoxymethoxy) benzaldehyde and Potassium cyanide synthesized in the above step (1). After adding 4.9 g, 65% Ethanol (aq) was added, and reflux cooling was performed for 8 hours.

After completion of the reaction, extraction was performed using Methylene chloride / H ₂ O, and the black viscous body obtained by collecting and concentrating an organic layer was prepared using a developing solution having a mixture ratio of ethyl acetate / n-hexane of 6/4. Purification via silica gel column chromatography gave the title compound in a purity of 98% and a yield of 52%.

(3) (Bis [1- (3,4,5-trimethoxy) phenyl) -2- [3-methoxy-4- (2-ethoxymethoxy) -phenyl]]-1,2-ethenedithiolato- (2) -S Synthesis of S '] Nickel

After mixing 10 g of (3-methoxy-4- (2-ethoxymethoxy) -3 ', 4', 5'-trimethoxy benzoin) synthesized in step (2) and 3.5 g of phosphorus pentasulate, 1,4-Dioxane 100 After reacting at 60 ° C. for 2 hours in a ml solvent, 4.1 g of Nickel chloride hexahydrate was dissolved in 67 g of pure water, and then added at a time, followed by reflux cooling.

After completion of the reaction, extraction was performed using Methylene chloride / H ₂ O. The extracted organic layer was concentrated in vacuo, and the black viscous body was purified by silica gel column chromatography using a developing solution having a mixture ratio of ethyl acetate / n-hexane of 7/3, thereby purifying the title compound. %, Yield 32%.

Example 2: (Bis [1- (3,4,5-trimethoxy) phenyl) -2- [3,4- (2-ethoxyethoxy) -phenyl]]-1,2-ethenedithiolato- (2) -S, Synthesis of S '] Nickel Complex Compound (Compound 2)

Example 3,4-ethoxyethoxy-3 ', 4', 5'-trimethoxy benzoin was used instead of 3-methoxy-4- (2-ethoxymethoxy) -3 ', 4', 5'-trimethoxy benzoin In the same manner as in 1, the title compound was synthesized. (Purity: 95%, yield: 30%).

Example 3: (Bis [1- (3,4- (2-ethoxyethoxy) phenyl) -2- [3-methoxy-4- (2-ethoxyethoxy) -phenyl]]-1,2-ethenedithiolato- (2) Synthesis of -S, S '] Nickel Complex Compound (Compound 3)

Except for using 3,4- (2-ethoxyethoxy) -3'-methoxy-4'-ethoxyethoxy benzoin instead of 3-methoxy-4- (2-ethoxymethoxy) -3 ', 4', 5'-trimethoxy benzoin In the same manner as in Example 1, the title compound was synthesized. (Purity: 96%, yield: 30%).

Example 4 Synthesis of Bis {1,2-bis [3,4- (2-ethoxyethoxy) phenyl)]-1,2-ethenedithiolato- (2) -S, S '] Nickel Complex Compound (Compound 4)

In the same manner as in Example 1, except that 3,4- (2-ethoxyethoxy benzoin was used instead of 3-methoxy-4- (2-ethoxymethoxy) -3 ', 4', 5'-trimethoxy benzoin, the title Compounds were synthesized (purity: 96%, yield: 33%).

Comparative Example 1 Synthesis of Bis {1,2-bis [(3,4,5-trimethoxy) phenyl)]-1,2-ethenedithiolato- (2) -S, S '} Nickel Complex Compound

The title compound in the same manner as in Example 1, except that 3,4,5-trimethoxy benzoin was used instead of 3-methoxy-4- (2-ethoxymethoxy) -3 ', 4', 5'-trimethoxy benzoin. Was synthesized. (Purity: 99.0%, yield: 40%).

Comparative Example 2: Synthesis of Bis [1,2-bis (4-methoxy) phenyl-1,2-ethenedithiolato- (2) -S, S '} Nickel Complex

The title compound was synthesized in the same manner as in Example 1, except that 4-methoxy benzoin was used instead of 3-methoxy-4- (2-ethoxymethoxy) -3 ', 4', 5'-trimethoxy benzoin. (Purity: 98%, yield: 35%).

Experimental Example 1 Analysis of Dithiol Nickel Complex Compounds

The maximum absorption wavelength, absorbance (max), melting point (mp) and solubility of the dithiol-based nickel complex compounds synthesized in Examples 1 to 4 and Comparative Examples 1 to 2, respectively, were measured. All analyzes were performed by MEK. The results are shown in Table 2 below, and the optical measurement results are shown in FIG. 1.

TABLE 2

As can be seen in Table 2, the dithiol-based nickel complex compound (Compounds 1 to 4) according to the present invention is capable of absorbing near-infrared in the long wavelength region, in particular, the solubility in the solvent in the compounds of Comparative Examples 1 and 2 It can be seen that it is much superior to.

Experimental Example 2: Solubility of Dithiol-Based Nickel Complex Compounds in Various Solvents

The solubility of the dithiol-based nickel complex compounds (Compounds 1 to 4) prepared in Examples 1 to 4, respectively, was measured, and the results are shown in Table 3 below.

[Table 3]

As can be seen in Table 3, it can be seen that the dithiol-based nickel complex compounds (Compounds 1 to 4) of Examples 1 to 4 according to the present invention exhibit very high solubility in various solvents. Considering that the solubility of the conventional near-infrared absorbing compounds in the solvents is about 0.1 to 0.5%, it can be seen that the solubility of the dithiol-based nickel complex compounds according to the present invention is excellent.

Example 5: Preparation of Coating Film

Methyl methacrylate (MMA) / Butyl Methacrylate (BMA) / Hydroxy ethyl methacrylte (HEMA) (5: 4: 1) Ternary copolymer solids 30 g and 50 mg of the compound of Example 2 were mixed with a solution of 70 g MEK. A coating solution was prepared.

The prepared coating solution was coated on a PET film using a film applicator (Sheen company) at 100 μm, and then dried at 100 ° C. for 1 hour to prepare a PET film coated with the compound of Example 1.

Example 6: Preparation of Coating Film

A coating film was prepared in the same manner as in Example 5 except that the compound of Example 3 was used instead of the compound of Example 2.

Experimental Example 3: Evaluation of Durability

The films prepared in Examples 5 and 6, respectively, were left at 80 ° C. and 95% RH for 72 hours, and then durability was evaluated under the following conditions.

<Durability Evaluation Condition>

* High temperature conditions (Table 4): The transmittance | permeability by wavelength before and after leaving to stand at 80 degreeC and 500 hours was compared.

* High temperature and high humidity conditions (Table 5): 65 ℃, 90% RH, the transmittance for each wavelength before and after 500 hours left was compared.

[Table 4]

TABLE 5

As shown in Tables 4 and 5, it can be seen that the coating films of Examples 5 and 6 according to the present invention have almost no change in transmittance even after long-term storage at high temperature and high temperature and high humidity conditions.

Experimental Example 4: Evaluation of Solubility by Compound

Based on the method of Example 1, Compounds 5 and 6 of Table 1 were also synthesized (Compound 5: Example 7, Compound 6: Example 8), and their solubility in MEK was measured, and the result was Is shown in Table 4 below with the results for the compounds of Examples 1-4.

TABLE 6

As shown in Table 4, Examples 2 to 4 (Compounds 2 to 4) have significantly higher solvent solubility than not only Example 1 (Compound 1) but also Examples 7 (Compound 5) and Example 8 (Compound 6). It can be seen that.

In order to confirm the effect according to solubility, the coating film (Example 9) was prepared in the same manner as in Example 5 using Example 1 (Compound 1) having a relatively high solubility.

As a result of observing the surface of the coating film of Example 9 (Compound 1), as shown in FIG. 2, some precipitate was confirmed. On the other hand, in the coating film of Example 5 (compound 2) and the coating film of Example 6 (compound 3), such precipitates were not found at all. This result is presumed to be due to the difference in solvent solubility.

Therefore, it can be seen that Examples 2 to 4 (Compounds 2 to 4) are particularly preferable in producing a coating film for an optical filter.

As described above, the long-wavelength near-infrared absorbing compound according to the present invention has a high transmittance of visible light and is particularly excellent in durability, solubility and compatibility with resins.

Those skilled in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

1 is a graph for the UV-vis spectrum data of Examples 1 to 4 and Comparative Examples 1 and 2 in Experimental Example 1;

2 is a photograph of the surface of the coating film of Example 9 (Compound 1) in Experimental Example 4.

Claims (11)

Dithiol nickel complex compound represented by the following general formula (1) that absorbs near infrared rays of long wavelength:

(One) Where m, m ', n and n' are each independently integers of 0 to 4, at least one of which is an integer of 1 to 4; x, x ', y and y' are each independently integers from 1 to 4; R ₁ , R ₁ ′, R ₂ and R ₂ ′ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted aryl group. The dithiol nickel complex compound of claim 1, wherein the dithiol nickel complex compound exhibits a maximum absorption wavelength in a region of 880 to 1000 nm. The dithiol nickel complex compound according to claim 1, wherein x and x 'are the same integer, and y and y' are the same integer. The method of claim 1, wherein the substituted or unsubstituted alkyl group is a substituted or unsubstituted C ₁ -C ₅ alkyl group, and the substituted or unsubstituted alkoxy group is a substituted or unsubstituted C ₁ -C ₅ alkoxy group. Or an unsubstituted aryl group is a substituted or unsubstituted C ₄ -C ₈ aryl group. The dithiol nickel complex compound according to claim ₁ , wherein R ₁ , R ₁ ′, R ₂ and R ₂ ′ are a hydrogen atom or a C ₁ -C ₅ alkoxy group. The dithiol nickel complex compound according to claim 1, wherein the dithiol nickel complex compound is selected from compounds 1 to 9.

The dithiol nickel complex compound according to claim 1, wherein the dithiol nickel complex compound is selected from compounds 2 to 3. The near-infrared absorbing material containing the dithiol nickel complex compound in any one of Claims 1-7. The method of claim 8, wherein the near-infrared absorbing material has a composition comprising 10 to 70% by weight of the dithiol-based nickel complex compound of Formula 1, 20 to 80% by weight of the binder resin, and 20 to 70% by weight of the solvent based on the total weight Near-infrared absorbing material, characterized in that made. A laminate comprising the dithiol nickel complex compound according to any one of claims 1 to 7. An optical filter comprising the laminate for absorbing near-infrared rays according to claim 10.

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