JPH11152413A - Nitronaphthalocyanine compound and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new compound having nitro group on each naphthalene ring, exhibiting excellent near infrared absorptivity and compatibility with solvents and resins and useful as a near infrared absorption filter, an agricultural film, a light guard, an optical recording medium, etc., having high durability. SOLUTION: This compound is expressed by formula I [R1 and R2 are each a (substituted) alkyl; M is a bivalent metal, an oxymetal or the like], e.g. a compound of formula II (one of X1 and X2 is nitro and the other is H). The compound of the formula I can be produced e.g. by reacting (A) a dicyanonaphthalene derivative of formula III (e.g. the compound of formula IV) with (B) a metal or a metal compound (e.g. copper chloride) in (C) a solvent preferably having a boiling point of >=130 deg.C such as n-amyl alcohol preferably at a temp. of 130-220 deg.C using 0.25-0.4 times mol of the component B and 5-20 times weight of the component C based on the component A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel nitronaphthalocyanine compound and a near-infrared absorbing material containing the compound. In detail, near infrared absorbing paint or ink, photothermal conversion material, optical card, optical recording medium, organic photoconductor, near infrared absorbing filter, heat ray shielding film,
The present invention relates to a nitronaphthalocyanine compound that can be developed for applications requiring near-infrared absorption such as agricultural films.

[0002]

2. Description of the Related Art Since naphthalocyanine compounds have excellent near-infrared absorption ability, various applications to optical cards, near-infrared absorption filters, heat ray shielding films, organic photoconductors of laser printers, etc. have been studied, and wavelengths according to the applications have been studied. Studies have been conducted mainly on compounds having selectivity and compounds having an absorption maximum at 700 to 800 nm, but for applications such as blocking heat rays, and for applications that need to absorb near-infrared rays in a long wavelength region. Thus, there are few examples of suitable compounds.

For example, Japanese Patent Application Laid-Open Nos.
JP-A-60-184565 discloses a naphthalocyanine compound substituted with an alkyl group, and JP-A-60-43605 discloses a chlorine atom, a sulfonic acid group, a sulfonamide group which may be substituted, or A naphthalocyanine compound substituted with an optionally substituted aminomethyl group is disclosed.
The naphthalocyanine compounds disclosed therein have an absorption maximum wavelength of at most about 800 nm and lack the ability to absorb near-infrared rays in a long wavelength region. In addition, JP-A-4-
No. 81995 discloses a naphthalocyanine compound which is substituted with a halogen atom and is a specific central metal compound. Although the naphthalocyanine compound disclosed here has a maximum absorption wavelength of up to 900 nm, it has little solubility in a solvent and needs to use a specific technique such as vapor deposition. Also GB 2200650
No., GB 2168372, J. Chem. Soc. PerkinTrans I, 245
3 (1988), octaalkoxynaphthalocyanine,
Although described, the compound was found to be unstable and unsuitable for applications requiring durability. Further, in Japanese Patent Application Laid-Open No. 2-298885, a compound having a nitro group is also included in the scope of claims, but as in the present invention, one nitro group is added to each of the four naphthalene rings of naphthalocyanine. The compound having the compound is not described in the text or Examples, and its advantages and stability are not mentioned at all.

[0004]

The problem to be solved by the present invention is as follows.
An object of the present invention is to provide a highly durable naphthalocyanine compound which absorbs a wavelength in the near infrared region of 0 nm or more and has excellent compatibility with a solvent or a resin, and a near infrared absorbing material using the compound.

[0005]

The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, a nitronaphthalocyanine compound having a nitro group introduced into a naphthalocyanine compound having an alkoxy group has been developed. The inventors have found that the compound has excellent properties as an infrared absorbing compound, and have completed the present invention.

That is, the present invention relates to a novel nitronaphthalocyanine compound represented by the following general formula (1).

Further, the present invention relates to a near-infrared absorbing resin composition and a near-infrared absorbing material containing the nitronaphthalocyanine compound.

[0008]

Embedded image (Wherein R ₁ and R ₂ each independently represent an optionally substituted alkyl group, and M is a divalent metal atom, trivalent or
It represents a substituted metal or oxymetal. )

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The nitronaphthalocyanine compound of the present invention represented by the above general formula (1) is a novel compound and a highly durable compound having a nitro group. General formula
In (1), R ₁ and R ₂ each independently represent an optionally substituted alkyl group, and M represents a divalent metal atom, a trivalent or tetravalent substituted metal, or an oxymetal.

In R ₁ and R ₂ , the alkyl group which may be substituted includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group,
sec-butyl group, n-pentyl group, isopentyl group,
Neopentyl group, n-hexyl group, isohexyl group, s
ec-hexyl group, n-heptyl group, isoheptyl group,
sec-heptyl group, n-octyl group, linear or branched alkyl group such as 2-ethylhexyl group, chloroethyl group, halogenoalkyl group such as trifluoromethyl group,

An alkoxyalkyl group such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, a propoxyethyl group, a butoxyethyl group, a hydroxyalkyl group such as a hydroxyethyl group or a hydroxypropyl group, a hydroxyethoxyethyl group, a hydroxyethoxyethoxyethyl. Examples thereof include hydroxypolyether groups such as groups, and alkoxypolyether groups such as methoxyethoxyethyl groups, ethoxyethoxyethyl groups, propoxyethoxyethyl groups, and butoxyethoxyethyl groups.

In particular, compounds in which R ₁ and R ₂ are linear or branched unsubstituted alkyl groups are preferred.

The divalent metal represented by M is Cu
(II), Zn (II), Fe (II), Co (II), Ni
(II), Ru (II), Rh (II), Pd (II), Pt
(II), Mn (II), Mg (II), Ti (II), Be
(II), Ca (II), Ba (II), Cd (II), Hg
(II), Pb (II), Sn (II) and the like.

As the monosubstituted trivalent metal, Al—Cl,
Al-Br, Al-F, Al-I, Ga-Cl, Ga-
F, Ga-I, Ga-Br, In-Cl, In-Br,
In-I, In-F, Tl-Cl, Tl-Br, Tl-
I, Tl-F, Al- C 6 H 5, Al-C 6 H 4 (C
_{H 3), In-C 6} H 5, In-C 6 H 4 (CH 3), In-
C ₆ H ₅ , Mn (OH), Mn (OC ₆ H ₅ ), Mn [OS
i (CH ₃ ) ₃ ], Fe—Cl, Ru—Cl and the like.

The disubstituted tetravalent metal includes CrCl ₂ ,
SiCl ₂ , SiBr ₂ , SiF ₂ , SiI ₂ , ZrC
l ₂ , GeCl ₂ , GeBr ₂ , GeI ₂ , GeF ₂ , Sn
Cl ₂ , SnBr ₂ , SnF ₂ , TiCl ₂ , TiBr ₂ ,
TiF ₂ , Si (OH) ₂ , Ge (OH) ₂ , Zr (O
H) ₂ , Mn (OH) ₂ , Sn (OH) ₂ , TiR ₂ , Cr
R ₂ , SiR ₂ , SnR ₂ , GeR ₂ [R represents an alkyl group, a phenyl group, a naphthyl group, and derivatives thereof], S
i (OR ') ₂ , Sn (OR') ₂ , Ge (OR ') ₂ ,
Ti (OR ′) ₂ , Cr (OR ′) ₂ [R ′ is an alkyl group, a phenyl group, a naphthyl group, a trialkylsilyl group,
Represents a dialkylalkoxysilyl group and a derivative thereof], Sn (SR ″) ₂ , Ge (SR ″) ₂ (R ″ represents an alkyl group, a phenyl group, a naphthyl group, and a derivative thereof).

Examples of oxymetals include VO, MnO,
TiO and the like are exemplified.

Particularly preferred M is Co, Ni, Cu, Z
n, Pd, AlCl, InCl, TiO, and VO.

The nitronaphthalocyanine compound represented by the general formula (1) of the present invention is produced, for example, by reacting a dicyanonaphthalene derivative represented by the following formula (2) with a metal or a metal compound in a solvent. it can.
Compound (2) as a starting material is easily available,
From the viewpoint of ease of synthesis, a dicyano naphthalene derivative in which a nitro group is substituted at the 5-position is preferable.

As a specific synthesis method, dicyanonaphthoquinone is used as a raw material, Synthetic Organic Chemistry, Vol. 16, No. 10 (1958) 50
Page, followed by the Chemical Society of Japan No.12 (1
981) The dicyano compound is synthesized by the method described on page 1916, and the obtained diol is easily alkylated.

[0020]

Embedded image (Wherein R _{1 and} R ₂ have the same meaning as in the general formula (1))

As the metal or metal compound, Al,
Si, Ti, V, Mn, Fe, Co, Ni, Cu, Z
n, Ge, Ru, Rh, Pd, In, Sn, Pt, P
b, Mg, Ca, Ba, Be, Cd, Hg and their halides, carboxylate, sulfate, nitrate, carbonyl compound, oxide, complex and the like. In particular, metal halides or carboxylate salts are preferably used,
Examples of these are copper chloride, copper bromide, copper iodide, nickel chloride, nickel bromide, nickel acetate, cobalt chloride, cobalt bromide, cobalt acetate, iron chloride, zinc chloride, zinc bromide, zinc iodide, Zinc acetate, vanadium chloride, vanadium oxytrichloride, palladium chloride, palladium acetate, aluminum chloride, manganese chloride, manganese acetate, manganese acetylacetone, manganese chloride, lead chloride, lead acetate, indium chloride, titanium chloride, tin chloride, etc. .

The amount of the metal or metal compound to be used is 0.2 to 0.6 with respect to the dicyanonaphthalene derivative of the general formula (2).
The molar amount is twice as much, preferably 0.25 to 0.4 times.

The solvent used for the reaction has a boiling point of 100
An organic solvent having a temperature of at least 130 ° C, preferably at least 130 ° C, is used. Examples include n-amyl alcohol, n-hexanol, cyclohexanol, 2-methyl-1-pentanol, 1-heptanol, 2-heptanol, 1-octanol, 2-ethylhexanol, benzyl alcohol, ethylene glycol, propylene glycol, Alcohol solvents such as ethoxyethanol, propoxyethanol, butoxyethanol, dimethylaminoethanol and diethylaminoethanol, trichlorobenzene, chloronaphthalene, sulfolane, nitrobenzene, quinoline, N, N-dimethylformamide, N-methyl-2
-Pyrrolidone, N, N-dimethylimidazolidinone,
High-boiling solvents such as N, N-dimethylacetamide and urea are exemplified.

The amount of the solvent to be used is 1 to 100 times by weight, preferably 5 to 20 times by weight, relative to the dicyanonaphthalene derivative.

In the reaction, ammonium molybdate or DBU (1,8-diazabicyclo [5,4,0] undecene) may be added as a catalyst. The addition amount is 0.1 to 1 mol of the dicyano naphthalene derivative.
It is 10 mol, preferably 0.5 to 2 mol. The reaction temperature is 100 to 300 ° C, preferably 130 to 220 ° C.

As a post-treatment after completion of the reaction, the target compound can be obtained by distilling off the solvent after the reaction or discharging the reaction solution into a poor solvent for the nitronaphthalocyanine compound and filtering the precipitate. Further, by purifying further by recrystallization or column chromatography, a higher-purity nitronaphthalocyanine compound can be obtained.

The near infrared absorbing resin composition and near infrared absorbing material of the present invention will be described. The nitronaphthalocyanine compound of the present invention is a compound having excellent durability.
That is, the stability in solution is dramatically improved compared to naphthalocyanine containing no nitro group, and the durability of the near-infrared absorbing resin composition and near-infrared absorbing material containing this nitronaphthalocyanine compound is also high. It is extremely high and does not lose its absorption capacity even after a long time, so it can be used in a wide range of fields that could not be used conventionally. Further, the reaction yield from naphthalonitrile to naphthalocyanine is remarkably improved, so that it is highly practical.

The near-infrared absorbing resin composition of the present invention is obtained by incorporating the nitronaphthalocyanine compound of the present invention into a resin. Examples of the method of adding them include a method of heating and mixing with a resin, and a method of dissolving in a solvent to form a coating or ink with the resin. At that time, additives such as an ultraviolet absorber and an antioxidant can be added as needed.

Examples of the resin to be used include polyethylene, polystyrene, polyacrylic acid, polyacrylic acid ester, polyvinyl acetate, polyacrylonitrile, polyvinyl chloride, polyvinyl fluoride such as polyvinyl fluoride, and addition polymers of vinyl compounds, polymethacrylic acid. , Polymethacrylate, polyvinylidene chloride, polyvinylidene fluoride, polyvinylidene cyanide, vinylidene fluoride / trifluoroethylene copolymer, vinylidene fluoride / tetrafluoroethylene copolymer, vinylidene cyanide / vinyl acetate copolymer, etc. A vinyl compound or a copolymer of a fluorine-based compound, a compound containing fluorine such as polytrifluoroethylene, polytetrafluoroethylene, and polyhexafluoropropylene; a polyamide such as nylon 6, nylon 66; a polyimide; Polyurethane, polypeptides, polyesters such as polyethylene terephthalate, polycarbonate, polyoxymethylene, polyethylene oxide,
Examples include polyethers such as polypropylene oxide, epoxy resins, polyvinyl alcohol, polyvinyl butyral, and the like, but are not limited to these resins.

Since the near-infrared absorbing resin composition of the present invention has a small absorption in the visible region and a high wavelength selectivity, it is excellent in light-to-heat conversion materials, optical recording media, near-infrared absorbing filters, agricultural films, heat ray shielding films, Near infrared absorbing paint,
It can be used as a near-infrared absorbing material such as a printing ink for preventing forgery and a light receiving element.

The method for producing a near-infrared absorbing material such as a film, a sheet and a plate using the above-mentioned nitronaphthalocyanine compound is not particularly limited.
For example, the following three methods can be used.

That is, (1) a method in which a nitronaphthalocyanine compound is kneaded with a resin and heat molding is performed to produce a resin plate or a film; (2) a paint containing the nitronaphthalocyanine compound is prepared, and a transparent resin plate is prepared. A method of coating on a transparent film or a transparent glass plate,
(3) A method in which a nitronaphthalocyanine compound is contained in an adhesive to produce a laminated resin plate, a laminated resin film, a laminated glass, and the like.

First, in the method (1) in which a resin is kneaded with a nitronaphthalocyanine compound and heat-molded, the resin material may be polyethylene, polystyrene, polyacrylic acid, polyacrylate, polyvinyl acetate, polyacrylonitrile, or polyacrylonitrile. Vinyl compounds such as vinyl chloride and polyvinyl fluoride and addition polymers of vinyl compounds, polymethacrylic acid, polymethacrylic acid esters, polyvinylidene chloride, polyvinylidene fluoride, polyvinylidene cyanide, vinylidene fluoride / trifluoroethylene copolymers, fluorine Vinyl compound or fluorine compound copolymer such as vinylidene cyanide / tetrafluoroethylene copolymer, vinylidene cyanide / vinyl acetate copolymer, polytrifluoroethylene, polytetrafluoroethylene, polyhexafluoropropylene Compounds containing fluorine such as nylon, polyamides such as nylon 6, nylon 66, polyimides, polyurethanes, polypeptides, polyesters such as polyethylene terephthalate, polycarbonates, polyethers such as polyoxymethylene, polyethylene oxide, polypropylene oxide, epoxy resins, polyvinyl alcohol , Polyvinyl butyral and the like,
It is not limited to these resins.

The processing temperature, film formation conditions, and the like are somewhat different depending on the base resin used. Usually, a nitronaphthalocyanine compound is added to the base resin powder or pellets, and the mixture is heated to 150 to 350 ° C. and dissolved. After forming, a resin plate is prepared, or a film is formed by an extruder, or a raw material is prepared by an extruder, and is stretched uniaxially or biaxially at 30 to 120 ° C. to 2 to 5 times. To obtain a film having a thickness of 10 to 200 μm. In addition, dyes, pigments or other near-infrared absorbing compounds for controlling color tone may be added in addition to additives used for ordinary resin molding such as an ultraviolet absorber and a plasticizer at the time of kneading. The addition amount of the nitronaphthalocyanine compound depends on the thickness of the resin to be produced, the desired absorption strength,
It varies depending on the desired near-infrared transmittance, the desired solar radiation transmittance, the desired visible transmittance and the like, but is usually 1 ppm to 10%.

In the method (2) for coating after coating, a method of dissolving the nitronaphthalocyanine compound of the present invention in a binder resin and an organic solvent to form a coating, and a method of reducing the nitronaphthalocyanine compound to several μm or less. There are a method of making water-based paint dispersed in an acrylic emulsion and a method of making water-based emulsion paint.

In the above method, usually, an aliphatic ester resin, an acrylic resin, a melamine resin, a urethane resin, an aromatic ester resin, a polycarbonate resin, an aliphatic polyolefin resin, an aromatic polyolefin resin,
A polyvinyl resin, a polyvinyl alcohol resin, a modified polyvinyl resin (PVB, EVA, or the like) or a copolymer resin thereof is used as a binder. As the solvent, a halogen-based, alcohol-based, ketone-based, ester-based, aliphatic hydrocarbon-based, aromatic hydrocarbon-based, ether-based solvent, or a mixture thereof is used.

The concentration of the nitronaphthalocyanine compound varies depending on the thickness of the coating, the desired absorption intensity, the desired near-infrared transmittance, the desired solar transmittance, the desired visible transmittance, and the like. 0.1 ~
100%. Further, the binder resin concentration is usually 1 to 50% with respect to the whole paint.

Similarly, in the case of the above-mentioned acrylic emulsion-based water-based paint, the nitronaphthalocyanine compound is finely pulverized (1 μm or less,
(Preferably 50 to 500 nm). Dyes, pigments, or other near-infrared absorbing compounds for controlling the color tone may be added to the paint, in addition to additives such as an ultraviolet absorber and an antioxidant, which are used in ordinary paints.

The paint prepared by the above method is applied to a transparent resin film, a transparent resin, a transparent glass or the like on a bar coater,
A near-infrared absorbing filter is prepared by coating with a blade coater, spin coater, reverse coater, die coater, spray or the like. It is also possible to provide a protective layer to protect the coating surface, or to bond the coating surface to a transparent resin plate, a transparent resin film, or the like. A cast film is also included in the method.

In the method (3) for producing a laminated resin plate, a laminated resin film, a laminated glass and the like by incorporating the nitronaphthalocyanine compound of the present invention into an adhesive, a general silicone-based adhesive is used as the adhesive. Urethane,
Known adhesives for laminated glass, such as an acrylic resin or a polyvinyl butyral adhesive (PVB) for laminated glass and an ethylene-vinyl acetate adhesive (EVA), can be used. The nitronaphthalocyanine compound was added to 0.
A near-infrared absorbing material is produced by bonding resin plates, a resin plate and a resin film, a resin plate and a glass, a resin film, a resin film and a glass, and a glass by using an adhesive added in an amount of 1 to 50%. There is also a method of thermocompression bonding.

The near-infrared absorption filter manufactured as described above is actually used more practically by providing an ultraviolet cut layer, a hard coat layer, an antireflection layer, or an adhesive layer on one or both sides thereof. Filter. If necessary, a near-infrared reflective layer laminated by alternately sputtering metal oxides such as indium oxide, tin oxide and zinc oxide and metals such as gold and silver, or a copper salt or zinc oxide as a main component The near-infrared absorbing paint of the present invention is prepared by atomizing a metal mixture, a tungsten compound, YbPO ₄ , ITO (tin-doped indium oxide), ATO (tin-doped antimony oxide) or the like into an average particle size of 100 μm or less. Can be combined with filters.

Since the near-infrared absorbing material of the present invention has low absorption in the visible region and high wavelength selectivity, it is excellent in light-to-heat conversion material, optical recording medium, near-infrared absorbing filter, agricultural film, heat ray blocking film, light receiving element. Etc. can be used.

[0043]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 Synthesis of nitronaphthalocyanine compound (A) 4.0 g of the following compound (a), 0.323 of copper (I) chloride
g, DBU 1.63 mL, n-amyl alcohol 20 m
After mixing L, the mixture was stirred under reflux for 6 hours. After cooling, the mixture was discharged into 100 mL of methanol, and the precipitate was separated by filtration to obtain 2.83 g (67% y) of the target compound (A).

[0045]

Embedded image

[0046]

Embedded image (X ₁ and X ₂ each represent a nitro group and the other is a hydrogen atom)

The maximum absorption wavelength (λmax) of the nitronaphthalocyanine compound in a toluene solution is 862 nm.
And the gram extinction coefficient (εg) was 102000 ml / g · cm. In addition, the compound had high solvent solubility and exhibited a solubility of 10% or more in toluene.

Further, in a stability test in a chloroform solvent under light-shielding conditions, the absorbance of λmax maintained 94.4% of the initial value even after 20 hours (FIG. 1). In the stability test, about 10 mg of a naphthalocyanine compound was dissolved in 1 L of chloroform so that the absorbance at λmax was 1, a measurement sample solution was prepared, and the solution was placed in a glass cell having a width of 1 cm, and room temperature and light shielding conditions were used. Is the change in absorbance with time.

Also, 1.3 g of the nitronaphthalocyanine compound (A) was mixed with 10 kg (trade name: “Delpet 80N”, manufactured by Asahi Kasei Kogyo Co., Ltd.), and 260 to 28 were mixed.
The mixture was melted at 0 ° C., and a near-infrared absorbing filter having a thickness of 3 mm was prepared using an extruder.

The filter efficiently absorbed near-infrared rays near 860 nm, and retained good absorption performance even after a 100-hour light fastness promotion test using a carbon arc lamp (63 ° C.).

Example 2 Synthesis of nitronaphthalocyanine compound (B) The compound (a) described in Example 1 (2.0 g), palladium (II) chloride (0.288 g), DBU (0.815 mL) and n-amyl alcohol (10 mL) were mixed. Thereafter, the mixture was stirred under reflux for 10 hours. After cooling, the mixture was discharged into 50 mL of methanol, and the precipitate was separated by filtration to obtain 1.15 g (54%) of the target compound (B).

[0052]

Embedded image (X ₁ and X ₂ each independently represent a nitro group, and the other is a hydrogen atom.)

The maximum absorption wavelength (λmax) of the nitronaphthalocyanine compound in a toluene solution is 838 n
m and the gram extinction coefficient (εg) was 166000 ml / g · cm. This compound also had high solvent solubility and exhibited a solubility of 10% or more in toluene.

Further, in a stability test in a chloroform solvent under light-shielded conditions, the absorbance of λmax maintained 95% of the initial value even after 20 hours (FIG. 1).

Further, a near-infrared absorbing filter was produced in the same manner as in Example 1 using 1.3 g of the nitronaphthalocyanine compound (B). The filter is 840 nm
The near-infrared rays in the vicinity were efficiently absorbed, and good absorption performance was maintained even after a 100-hour light fastness promotion test using a carbon arc lamp (63 ° C.).

Example 3 Synthesis of nitronaphthalocyanine compound (C) 2.0 g of the compound (a) described in Example 1, 0.211 g of anhydrous nickel (II) chloride, 0.815 mL of DBU, n-
After mixing 10 mL of amyl alcohol, the mixture was stirred under reflux for 10 hours. After cooling, the mixture was discharged into 50 mL of methanol, and the precipitate was separated by filtration to obtain 1.32 g of the target compound (C).

[0057]

Embedded image (X ₁ and X ₂ each independently represent a nitro group, and the other is a hydrogen atom.)

The maximum absorption wavelength (λmax) of the nitronaphthalocyanine compound in a toluene solution is 856 n.
m. This compound also had high solvent solubility and exhibited a solubility of 10% or more in toluene.

Further, in a stability test in a chloroform solvent under light-shielding conditions, the absorbance of λmax maintained 88% of the initial value even after 20 hours (FIG. 1).

Further, 1 g of the nitronaphthalocyanine compound (C) and an ultraviolet absorber (trade name: “Tinuvin 32”)
7 ", manufactured by Ciba-Geigy Co., Ltd.) and dissolved in 300 ml of ethyl cellosolve, and an acrylic paint (trade name;
"Almatex 1043" manufactured by Mitsui Toatsu Chemicals, Inc.) 20
0 g was added to prepare a near infrared absorbing coating. The paint was coated on glass by flow coating so that the film thickness became 10 μm.

The filter efficiently absorbed near-infrared light near 860 nm, and retained good absorption performance even after a 100-hour light fastness promotion test using a carbon arc lamp (63 ° C.).

Example 4 Synthesis of nitronaphthalocyanine compound (D) 2.5 g of the following compound (b), 0.162 of copper (I) chloride
g, DBU 0.815 mL, and diethylene glycol dimethyl ether 10 mL.
Stirred for hours. After cooling, the mixture was discharged into 50 mL of methanol, and the precipitate was separated by filtration to obtain 1.07 g of the target compound (D).

[0063]

Embedded image

[0064]

Embedded image (X ₁ and X ₂ each independently represent a nitro group, and the other is a hydrogen atom.)

The maximum absorption wavelength (λmax) of the nitronaphthalocyanine compound in a toluene solution is 868 n
m. This compound also had high solvent solubility and exhibited a solubility of 10% or more in toluene. Even in the stability test in chloroform solvent and after 20 hours, λ
The absorbance at max maintained the initial 95%.

A near-infrared absorbing filter was produced in the same manner as in Example 3 except that 1 g of the nitronaphthalocyanine compound (D) was used.

The filter efficiently absorbed near-infrared rays near 870 nm, and retained good absorption performance even after a 100-hour light fastness acceleration test using a carbon arc lamp (63 ° C.).

Example 5 The nitronaphthalocyanine compound (A) synthesized in Example 1 and polyethylene terephthalate pellets 120
3 (manufactured by Unitika) in a ratio of 0.02: 1,
After melting at 60 to 280 ° C. and producing a film having a thickness of 100 μm by an extruder, the film was biaxially stretched to produce a near infrared absorbing filter having a thickness of 25 μm.

Further, a carbon arc lamp (6
(3 ° C.), a light fastness test was carried out. As a result, no deterioration was observed and the light fastness was good.

Comparative Example 1 Synthesis of Octaalkoxynaphthalocyanine Compound (E) 10.0 g of the following compound (c), 0.921 of copper (I) chloride
g, DBU 4.63 mL, amyl alcohol 100 m
After mixing L, the mixture was stirred at 150 ° C. for 10 hours and subjected to post-treatment in the same manner as in the example, but only 0.32 g of the obtained naphthalocyanine was obtained (yield 3%).

[0071]

Embedded image

[0072]

Embedded image

The maximum absorption wavelength (λmax) of the naphthalocyanine compound in a toluene solution was 852 nm.

Further, a stability test was carried out using the compound in chloroform.
The absorbance at max dropped to the initial 57.7% (FIG. 1).

Further, in the same manner as in Example 1, a near-infrared absorbing filter having a thickness of 3 mm was produced using polymethyl methacrylate (PMMA). When the filter was subjected to a light resistance acceleration test using a carbon arc lamp (63 ° C.), significant absorption deterioration was observed.

Examples 6 to 21 By the same method as the nitronaphthalocyanine compound (A) synthesized in Example 1, the nitronaphthalocyanine compounds shown in Table 1 were obtained in good yield. Table 1 shows the results. All compounds selectively and efficiently absorbed light in the near infrared region, and had good results in stability tests as shown in the table.

As shown in the following formula (F), the substitution position of the nitro group in the table is expressed as β-position when the position is 1 or 4, 10, or 13, 19, 22, 28 or 31. , 2 or 3, 11 or 12, 20, 20 or 21, 29 or 30 is expressed as γ position.

[0078]

Embedded image

[0079]

[Table 1]

Comparative Examples 2 to 17 In the same manner as in Comparative Example 1, a naphthalocyanine compound containing no nitro group was synthesized, and the obtained compound was subjected to a spectrum measurement and a stability test. Table 2 shows the results. The yield was low and the stability of the obtained compound was low.

[0081]

[Table 2]

[0082]

The nitronaphthalocyanine compound represented by the general formula (1) of the present invention has excellent near-infrared absorption ability,
It is a compound having excellent solubility in solvents and resins and excellent durability, and also a near-infrared absorbing material using the compound,
The material has excellent near-infrared absorption ability and durability, and can be suitably used for applications such as near-infrared absorption filters, agricultural films, optical cards, and optical recording media.

[Brief description of the drawings]

FIG. 1 is a graph showing the results of a stability test in chloroform of naphthalocyanine compounds obtained in Examples 1 to 3 and Comparative Example 1.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryu Ooi 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsui Chemicals, Inc.

Claims (5)

[Claims] 1. A nitronaphthalocyanine compound represented by the following general formula (1). Embedded image (Wherein R ₁ and R ₂ each independently represent an optionally substituted alkyl group, and M is a divalent metal atom, trivalent or
It represents a substituted metal or oxymetal. ) 2. The naphthalocyanine compound according to claim ₁ , wherein R ₁ and R ₂ are an unsubstituted alkyl group. 3. M is Co, Ni, Cu, Zn, Pd,
3. The nitronaphthalocyanine compound according to claim 1, which is AlCl, InCl, TiO, or VO. 4. A near-infrared absorbing resin composition comprising the nitronaphthalocyanine compound according to claim 1. 5. A near-infrared absorbing material comprising the nitronaphthalocyanine compound according to claim 1.