Azo dye, dye composition, colorant for aluminum anodic oxide coating, colored molded article, method for producing colored anodic oxide coating, and method for producing said dye

Abstract

Provided is an azo dye represented by general formula (1) (wherein the molecular skeleton and groups are as defined in the description). The provided azo dye forms a yellow colored anodic oxide coating using a single dye on the surface of an anodic oxide coating on aluminum or an alloy thereof, and has excellent light resistance and does not contain environmentally hazardous substances such as heavy metals. Also provided are a dye composition and a colorant, and a colored molded body having the coating. Further provided are a method for producing the colored anodic oxide coating and a method for producing the azo dye.

Description

Azo dye, dye composition, coloring agent for aluminum anodized film, colored molded article, method for producing a colored anodized film, and method for producing the dye.

[0001] This invention relates to an azo dye, a dye composition suitable for use as a coloring agent for anodized coatings of aluminum or aluminum alloys, and a colored molded article having a colored anodized coating produced using the coloring agent. Furthermore, the invention relates to a method for producing a colored anodized coating of aluminum or aluminum alloy using the dye and dye composition, and a method for producing the dye.

[0002] Conventionally, a method has been used to color the surface of aluminum (including its oxides or alloys) by passing an electric current through aluminum as the anode in an electrolyte solution containing water and a suitable acid (anodic oxidation) to form a porous aluminum oxide film (anodized film) on the surface, and then coloring the surface with an organic pigment (or organic dye) as a coloring agent (Patent Documents 1 to 6, etc.).

[0003] Chromium-containing dyes for anodized aluminum coatings (colorants for anodized aluminum) (Patent Documents 1-6, etc.) exhibit a variety of hues such as black, gray, blue, green, yellow, orange, and red, and have been widely used due to their excellent lightfastness and heat resistance. However, in recent years, from an environmental perspective, there has been a demand for dyes that do not contain heavy metals such as chromium and have a variety of hues. Furthermore, from an environmental perspective, there is a demand for dyes that do not contain halogens such as chlorine or bromine.

[0004] Clariant's Sanodye® Black OA is known as a black dye for anodized aluminum coatings that does not contain heavy metals. However, while this dye has good lightfastness when used for dark dyeing, its lightfastness is insufficient when used for light dyeing (Patent Document 7).

[0005] To date, dyes for anodized aluminum coatings in colors such as purple, blue, green, yellow, red, brown, and black have been developed that do not contain heavy metals or other environmentally harmful substances (see Patent Documents 8-11, etc.). There is still a demand for dyes that exhibit a variety of hues according to market needs, have excellent durability such as lightfastness or heat resistance, and have a low environmental impact.

[0006] Japanese Unexamined Patent Publication No. Hei 9-302256 International Publication No. WO 2019 / 189209 International Publication No. WO 2019 / 189211 Japanese Unexamined Patent Publication No. Sho 60-235867 Japanese Unexamined Patent Publication No. Hei 6-93195 Japanese National Publication of International Patent Application No. 2002-522617 US Patent No. 2580869 Specification Japanese National Publication of International Patent Application No. 2003-504426 Japanese Unexamined Patent Publication No. 2021-38380 Japanese Unexamined Patent Publication No. 2021-55095 International Publication No. WO 2024 / 070669

[0007] One object of the present invention is to provide an azo dye capable of forming, on the surface of an anodized film of aluminum or aluminum alloy, a colored anodized film which is excellent in light resistance, does not contain environmentally hazardous substances such as heavy metals, and is a monochromatic (single dye) yellow-based color (including yellows with different shades, golden yellow, yellow with brownish / reddish tint (including yellowish brown), and yellow with greenish tint), a dye composition containing the dye, and a coloring agent. Another object of the present invention is to provide a colored molded article having the colored anodized film, a method for producing the colored anodized film using the dye composition, and a method for producing the azo dye.

[0008] The present invention aims to solve the above problems and is configured as follows.

[0009] [1] An azo dye represented by the following general formula (1).

[0010]

[0011] [In the formula (1), R １ represents -OH or -COOX, R ２ to R ５ each independently represent -H, -SO ３ X, -COOX, -NO ２ , -OH, -CH ３ , -CH ２ CH ３ , -SO ２ CH ３ , -SO ２ CH ２ CH ３ or a halogen atom, each X independently represents a non-chromophoric cation, R ６ and R ７Each of these is independently a non-chromogenic cation or an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group, or -CH ２ OH, -OCH ３ or - OCH ２ CH ３ This represents Z １ ~Z ３ Each of these independently represents either an oxygen atom or a sulfur atom.

[0012] [2] In the above general formula (1), R １ ga -OH, R ２ ~R ４ ga-H,-SO ３ X, -COOX, or -NO ２ And R ５ ga -H, and X is H ＋ or Na ＋ The azo dye described in [1].

[0013] [3] In the above general formula (1), R ６ and R ７ H ＋ Na ＋ or -CH ３ Z １ ~Z ３ The azo dye according to [1] or [2], wherein is an oxygen atom.

[0014] [4] In acid solution, temperature 19-21°C, current density 1.0A / dm ２ A colored molded body having an aluminum colored anodic oxide film or an aluminum alloy colored anodic oxide film is obtained by anodizing an aluminum substrate for 15 minutes, and then coloring it with a dye composition containing 2.0% by mass of an azo dye represented by general formula (1) at a temperature of 50-60°C for 3 minutes. ＊ a ＊ b ＊ Lightness (L) in a color system ＊ ) is 75.00 or more and 90.00 or less, b ＊ The value is between 75.00 and 99.00, and the saturation (C ＊ An azo dye according to any one of [1] to [3], wherein the ratio is 80.80 or higher.

[0015] [5] In acid solution, temperature 19-21°C, current density 1.0A / dm ２ An aluminum substrate is anodized for 15 minutes to create an anodic oxide film. This film is then colored using a dye composition containing 2.0% by mass of an azo dye represented by general formula (1) at a temperature of 50-60°C for 3 minutes. The resulting colored molded body has an aluminum colored anodic oxide film or an aluminum alloy colored anodic oxide film, and the color difference ΔE in the lightfastness test of the Japanese Industrial Standard (JIS H 8685-1) is measured. ＊ ａｂ An azo dye according to any one of [1] to [4], wherein the (CIE 1976) is 3.00 or less.

[0016] A dye composition containing an azo dye as described in any of [6] [1] to [5].

[0017] A coloring agent containing the dye composition described in [7] and [6], which is used for anodic oxide coatings of aluminum or aluminum alloys as described in Japanese Industrial Standard (JIS H 8601).

[0018] A colored molded article having a colored anodic oxide film of aluminum or an aluminum alloy, using the coloring agents described in [8] and [7].

[0019] A method for producing a colored anodic oxide film of aluminum or a colored anodic oxide film of an aluminum alloy, using a dye composition containing 0.02 to 10% by mass of the azo dye described in [9] [1].

[0020] A method for producing an azo dye as described in

[10] [1], wherein the azo dye represented by general formula (1) is obtained by a diazo coupling reaction between a diazotized product obtained by diazotizing a compound represented by the following general formula (1-0) and a compound represented by the following general formula (1-1) and / or a salt thereof.

[0021]

[0022] [In equations (1-0) and (1-1), R １ ~R ７ and Z １ ~Z ３ This is the same as the definition described in general formula (1) above.

[0023] The present invention provides an azo dye capable of forming a yellow-toned colored anodic oxide film on the surface of aluminum or aluminum alloys that is highly lightfast, free from environmentally harmful substances such as heavy metals, and can be applied in a single color (single dye) (including yellows of varying shades and brightness, golden yellow, brownish-reddish yellow (including yellowish-brown), and greenish-yellow), a dye composition containing the dye, and a colorant. Furthermore, by using the azo dye and dye composition of the present invention, a colored molded article having a colored anodic oxide film of aluminum or aluminum alloy with excellent lightfastness can be provided, and the present invention also provides a method for producing the colored anodic oxide film and a method for producing the azo dye.

[0024] The embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below and can be implemented with various modifications within the scope of its gist. The azo dye represented by the general formula (1) above (hereinafter also simply referred to as azo dye (1) or dye (1)) will be described in detail below, but the present invention is not limited to these.

[0025] In general formula (1), R １ ~R ７ The "X" included in, or "-COOX" or "-SO" ３ The "non-chromogenic cation" represented by "X" in "X" is specifically a hydrogen ion (H ＋ ), lithium ion (Li ＋ ), sodium ions (Na ＋ ), potassium ions (K ＋ Alkali metal ions such as NH ４ ＋ , N ＋ R １１ R １２ R １３ R １４ An example is the ammonium ion represented by R. １１ ~R １４ Examples of each are alkyl groups having 1 to 3 carbon atoms (methyl group, ethyl group, n-propyl group, isopropyl group). Also, the multiple X in general formula (1) may be the same or different. Examples of each of X are H＋ , Na ＋ or NH ４ ＋ is preferable, and H ＋ or Na ＋ is more preferable.

[0026] In general formula (1), R ２ to R ５ Examples of the "halogen atom" represented by include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and as the "halogen atom", a fluorine atom or a chlorine atom is preferable.

[0027] In general formula (1), R １ represents -OH or -COOX, and is preferably -OH.

[0028] In general formula (1), R ２ to R ５ each independently represent -H, -SO ３ X, -COOX, -NO ２ , -OH, -CH ３ , -CH ２ CH ３ , -SO ２ CH ３ , -SO ２ CH ２ CH ３ or a halogen atom. In general formula (1), R ２ to R ４ are preferably -H, -SO ３ X, -COOX or -NO ２ , and R ５ is preferably -H. Further, it is more preferable that at least one of R ２ or R ４ is -SO ３ X, -COOX or -NO ２ Having the above-described substituents tends to increase the oxidation potential of the entire molecule, so it is considered that a colored anodized film excellent in light resistance can be formed.

[0029] In general formula (1), R ６ and R ７Each of these is independently a non-coloring cation or an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group, or -CH ２ OH, -OCH ３ or - OCH ２ CH ３ Represents R ６ and R ７ Because these substituents tend to increase the overall oxidation potential of the molecule, it is thought that a colored anodic oxide film with excellent light resistance can be formed. ６ or R ７ Examples of "alkyl groups with 1 to 3 carbon atoms" represented by R include methyl, ethyl, n-propyl, and isopropyl groups. ６ and R ７ H ＋ Na ＋ or -CH ３ It is preferable that this be the case.

[0030] Specific examples of the dyes of the present invention (azo dyes (1)) represented by general formula (1) are shown below. These include all possible stereoisomers and tautomers. When the azo dye represented by general formula (1) is expressed as [AP]-N=N-[BA] as shown in general formula (2) below, the part represented by [AP] is R as shown in general formula [AP] below. １ ~R ５ It is represented by a phenyl group having R. Also, the part represented by the general formula [BA] below is as shown in formula [BA] below. ６ , R ７ and Z １ ~Z ３ It is represented by a barbiturate group having the following properties. In formulas [AP] and [BA], "*" represents the bond with the azo group "-N=N-".

[0031]

[0032] [In formulas (AP) and (BA), R １ ~R ７ and Z １ ~Z ３ This is the same as the definition described in general formula (1) above.

[0033] In general formula (1), specific examples of the group represented by the general formula [AP] are shown in the following formulas (AP1) to (AP13), but the present invention is not limited to these. Also, specific examples of the group represented by the general formula [BA] are shown in the following formulas (BA1) to (BA15), but the present invention is not limited to these. Furthermore, in the following specific examples of the group, -SO ３ In X or -COOX, "X" represents examples of "H" or "Na," but is not limited to these.

[0034]

[0035]

[0036] The azo dye (1) of the present invention, represented by general formula (1), is shown more specifically below. The specific compound shown below has a planar structural formula and includes all possible stereoisomers and tautomers. In addition, some of the following formulas omit hydrogen atoms. Preferred specific examples of the azo dye (1) of the present invention are shown in the following formulas (A-1) to (A-82), but the present invention is not limited to these. In the dyes (1) below, X independently represents a non-chromogenic cation, but X is "H ＋ " or "Na ＋ This describes the case where X is H, Li, K, or ammonium ions, etc. ＋ Na ＋ Other non-color-developing cations are acceptable.

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051] In this specification, in the azo dye (1), -SO ３ When a non-coloring cation "X" such as X or -COOX is present, multiple specific examples of dyes can be represented by the type and number of X. For example, the dye (A-3) below can be represented by the following formulas (A-3-1), (A-3-2), (A-3-3), etc. In the present invention, unless otherwise specified, dyes with the same structure excluding the non-coloring cation portion are treated as having similar dye properties.

[0052]

[0053] The compound represented by general formula (1) can be obtained, for example, by a method that includes a step (coupling step) of diazotizing a compound represented by the following general formula (1-0) to obtain a diazotized compound and / or a salt thereof. That is, the compound represented by general formula (1-0) may be obtained by a diazotizing reaction between a diazotized compound represented by general formula (1-0) and a compound represented by the following general formula (1-1) and / or a salt thereof.

[0054]

[0055] [In equations (1-0) and (1-1), R １ ~R ７ and Z １ ~Z ３ This is the same as the definition described in general formula (1) above.

[0056] An example of a method for producing the compound (azo dye) of the present invention represented by the general formula (1) is shown below, but the method is not limited to this method. Specifically, first, an aromatic amine derivative represented by the general formula (1-0) and having a suitable substituent is reacted at a suitable temperature with a basic aqueous solution prepared using sodium nitrite or the like in an acidic aqueous solution such as hydrochloric acid or sulfuric acid to obtain a diazo component.

[0057] On the other hand, a salt (coupler component) of the compound represented by general formula (1-1) can be obtained by dissolving the compound represented by general formula (1-1) in an aqueous solution such as sodium hydroxide and reacting it. The compound represented by general formula (1-1) may also be used as the coupler component (also simply referred to as coupler component (1-1)).

[0058] Next, by reacting the diazo component with the coupler component (1-1) (diazo coupling reaction), the compound represented by the general formula (1) and / or a salt thereof is obtained as an azo compound (azo dye). The method for producing the compound represented by the general formula (1) (azo dye) according to this embodiment includes the step of obtaining the compound represented by the general formula (1) obtained as described above.

[0059] The aforementioned dye (1) can be purified by known methods such as purification by column chromatography; adsorption purification using silica gel, activated carbon, activated clay, etc.; and various crystallization methods using solvents or acids.

[0060] The dyes (1) of the present invention, their intermediates, or various products obtained by the above manufacturing method can be identified and their physical properties evaluated by methods such as ultraviolet-visible absorption spectroscopy (UV-Vis), thermogravimetric-differential thermal analysis (TG-DTA), gas chromatography (GC), thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC / MS), gas chromatography-mass spectrometry (GC / MS), and nuclear magnetic resonance (NMR) analysis.

[0061] The azo dye (1) of the present invention, represented by general formula (1), can be used as a component of a dye composition. That is, dye (1) can be used alone as a single-color dye to color metals such as aluminum or their alloys, natural fibers, synthetic fibers, plastics, wood, stone (including concrete, etc.), or paper, and is more preferably used as a coloring agent for anodic oxide films of aluminum or aluminum alloys. Two or more types of dye (1) may be used in combination to obtain a variety of colors by mixing. Other components may be mixed into the dye composition for optimal dyeing (coloring using the dye). Specifically, these include liquids (solvents) such as water, alcohol, and solvents; additives such as surfactants; etc. Water is preferred as the solvent. Dye (1) may also be used in combination with other dyes as a component of a dye composition. Other pigments refer to compounds, pigments, or dyes other than pigment (1), and specifically include ruthenium complexes, coumarin dyes, cyanine dyes, merocyanine dyes, rhodacyanine dyes, phthalocyanine dyes, porphyrin dyes, other xanthene dyes, anthraquinone dyes, azomethine dyes, isoindolinone dyes, isoindoline dyes, diketopyrrolopyrrole dyes, perylene dyes, quinacridone dyes, indigoid dyes, dioxazine dyes, and the like. When pigment (1) is used in combination with other components, the amount of other components used relative to pigment (1) may be 10% by mass or more, 20% by mass or more, 40% by mass or more, 200% by mass or less, 150% by mass or less, 100% by mass or less, or 70% by mass or less.

[0062] When using a dye composition containing the azo dye (1) of the present invention as a coloring agent for an anodized film of aluminum or an aluminum alloy, the coloring method (dyeing conditions) may be as follows: the concentration of the dye (1) in the dye composition (dye concentration: including the concentration when the solution is stored or when dyeing) may be 0.02% by mass or more, 0.05% by mass or more, 1% by mass or more, 2% by mass or more, 10% by mass or less, 7% by mass or less, 5% by mass or less, or 3% by mass or less. A lower concentration of the compound (dye) allows for lighter coloring, while a higher concentration allows for intermediate to dark coloring. The dyeing time may be 5 seconds or more, 10 seconds or more, 20 seconds or more, 40 seconds or more, 1 minute or more, 2 minutes or more, 60 minutes or less, 30 minutes or less, 10 minutes or less, 5 minutes or less, or 3 minutes or less. The dyeing time can be appropriately selected according to the dye concentration.

[0063] Here, anodizing of aluminum or aluminum alloy means aluminum that has been treated in an electrolyte solution such as an acidic aqueous solution to form a porous oxide layer (oxide film) on the surface of the aluminum or aluminum alloy (hereinafter, unless otherwise specified, "aluminum" may include "aluminum alloy"). In this invention, "coloring agent used for anodized film of aluminum or aluminum alloy" means a coloring agent that can color (or dye) this porous aluminum surface by adsorbing a dye into the pores. Normally, in order to improve the durability and light resistance of the colored aluminum surface, a sealing treatment is performed after coloring to close the pores.

[0064] In the anodizing of aluminum according to the present invention, examples of aluminum include aluminum, aluminum oxide, aluminum alloys with other metals, and other metals or metal compounds containing aluminum.

[0065] A coloring method using a coloring agent for anodized aluminum or aluminum alloy (a method for producing a colored anodized film, including related evaluation methods) can be any known method as anodizing dyeing. For example, methods described in Japanese Industrial Standard JIS H 8601:1999 "Anodized Films of Aluminum and Aluminum Alloys" and the referenced standards related to anodized films described in this standard, as well as Patent Documents 1 to 11, can be used. A specific example of an aluminum coloring method is shown below.

[0066] First, an aluminum plate (including aluminum alloy plates; the shape of the colored molded product of the present invention is not limited to a plate shape. Specifically, the plate-shaped aluminum may be curved, or it may be molded and processed into the shape of a box or other product) is degreased using an acidic aqueous solution such as sulfuric acid, oxalic acid, chromic acid, or sulfonic acid, and then washed with water. Next, the degreased aluminum plate is used as the anode, and electrolysis is performed using an acidic aqueous solution as the electrolyte to form an anodic oxide film (anodized film) with many pores on the aluminum anode surface (anodic oxidation treatment), and then washed with water. Subsequently, after appropriate surface adjustment and washing, the aluminum plate is immersed in an aqueous solution of a coloring agent for aluminum anodic oxide films containing a dye composition containing the compound of the present invention (azo dye), the dye is adsorbed into the pores (dyeing, electrolytic coloring), and the pores on the surface are sealed with aluminum oxide hydrate or the like to form a sealing substance, thereby obtaining a colored molded product. When using two or more of the dye compositions of the present invention in combination, or when using the dye compositions of the present invention in combination with other dyes, a mixed solution of all the dyes to be used may be prepared and the anodized aluminum plate may be immersed in it, or each dye solution may be prepared separately and the anodized aluminum plate may be immersed in each solution in sequence.

[0067] The electrolytic conditions for coloring the anodized aluminum of this invention may be either DC electrolysis or AC electrolysis, with DC electrolysis being preferred. The current density is 0.1 A / dm². ２ Above, 0.2A / dm ２ Above, 0.5A / dm ２ The above is sufficient, and 10 A / dm ２ Below, 7A / dm２ Below, 5A / dm ２ Below, 3A / dm ２ The following conditions may apply: The energizing time may be 10 seconds or more, 30 seconds or more, 1 minute or more, 3 minutes or more, 10 minutes or more, 60 minutes or less, 40 minutes or less, or 20 minutes or less. The thickness of the anodic oxide film may be 1 μm or more, 2 μm or more, 4 μm or more, 50 μm or less, 20 μm or less, or 10 μm or less. These anodic oxidation conditions result in darker coloration as the energizing time increases and the anodic oxide film becomes thicker. By adjusting these conditions, it is possible to adjust the color from light to medium to dark.

[0068] The processing temperature for each step of the anodizing to dyeing process described above is preferably a suitable temperature. The temperature during anodizing may be 0°C or higher, 10°C or higher, and 80°C or lower, 60°C or lower, or 40°C or lower. The temperature during dyeing may be 10°C or higher, 20°C or higher, 30°C or higher, 40°C or higher, 70°C or lower, or 60°C or lower. The other processing temperatures are preferably between 10 and 80°C.

[0069] The dye composition of the present invention can also be used with anodized metals other than aluminum and their alloys. For example, it can be applied to nonmetals such as conductive plastics, as long as the dye can be adsorbed into the pores of anodized materials such as magnesium, zinc, titanium, and zirconium.

[0070] When the azo dye of the present invention is used as a coloring agent for anodized aluminum or aluminum alloy films, a sample of a colored molded body having a colored anodized aluminum or aluminum alloy film (hereinafter also simply referred to as colored aluminum) can be prepared and evaluated. Specifically, the hue, lightfastness, heat resistance, etc., of the colored aluminum sample can be evaluated by measuring them. Hue can also be evaluated visually for color and uniformity. The density (K / Sd) and CIE L can be measured using a colorimeter. ＊ a ＊ b ＊ Color tone according to the color system (brightness L) ＊ a ＊ , b ＊ ), saturation C ＊ , color difference (ΔE ＊ΔE ＊ ａｂ ) and other parameters may be measured and used for evaluation. Note that saturation C ＊ This can be calculated using the following formula (Equation 1). C ＊ = [(a ＊ ) ２ + (b ＊ ) ２ ] １／２ -- (Equation 1) The lightfastness of colored aluminum can be evaluated by irradiating the sample with light that simulates sunlight, including ultraviolet light, for a certain period of time, and measuring the numerical changes in hue, color, and other properties of the colored aluminum before and after the test, as well as the color difference. Note that the color difference ΔE ＊ ａｂ This can be calculated using the following formula (Equation 2): ΔE ＊ ａｂ = [(ΔL ＊ ) ２ + (Δa ＊ ) ２ + (Δb ＊ ) ２ ] １／２ -- (Equation 2)

[0071] The colors that can be represented by the colorants used in the anodic oxide film of aluminum or aluminum alloy according to the present invention are specifically yellow in nature, and can represent yellow of varying shades, golden yellow, brownish-reddish yellow (brownish-yellow, reddish-yellow), yellowish-brown, greenish-yellow, or similar colors, or dull colors obtained by mixing these. More specifically, the above-mentioned yellow in nature that can be generally distinguished by the human eye may be, for example, the colors listed in the Japanese Industrial Standard JIS Z 8102:2001 "Color Names of Object Colors," and may be colors obtained by adjusting the brightness and saturation of those colors. As for color names, they may be Munsell color system color names, Western color names such as English, common names listed in the JIS standard, or traditional Japanese color names. For example, in the yellow family, examples include yellow, golden yellow, dandelion yellow, tortoiseshell, mugwort, wheat yellow, mustard yellow, gardenia yellow, pale yellow, oryza, rapeseed yellow, marigold yellow, golden yellow, amber, daylily yellow, lime yellow, Chartreuse yellow, golden yellow, sulfur yellow, lemon yellow, straw yellow, and similar colors. The coloring agent of the present invention can also represent a mixture (intermediate color) by using the compound represented by the azo dye (1) of the present invention in combination with other dyes.

[0072] When using the azo dye of the present invention, the current density should be 1.0 A / dm² in an acidic solution at a temperature of 19-21°C. ２ The aluminum substrate, which has been anodized for 15 minutes to produce an anodic oxide film, is then colored using a dye composition containing 2.0% by mass of an azo dye represented by general formula (1) at a temperature of 50-60°C for 3 minutes, resulting in a colored molded body having an aluminum colored anodic oxide film or an aluminum alloy colored anodic oxide film, with a color (brightness L) ＊ a ＊ , b ＊ ) was measured and the brightness (L ＊ ) is 75.00 or more and 90.00 or less, b ＊ The value is between 75.00 and 99.00, and the saturation (C ＊ It is preferable that the value is 80.80 or higher. Using this colored molded sample, the color difference ΔE before and after the light irradiation test is determined according to the Japanese Industrial Standard JIS H 8685-1 lightfastness test. ＊ ａｂ(or ΔE ＊ The color of the colored molded body may be evaluated by (brightness L). When using the azo dye of the present invention, specifically, the color of the colored molded body (brightness L) may be evaluated by (brightness L). ＊ a ＊ , b ＊ In the measurement results of the light irradiation test, the color difference ΔE before and after the test ＊ ａｂ It is preferable that the (CIE 1976) value is 3.00 or less. ＊ ａｂ There is no particular lower limit, but it may be 1.00 or higher. In addition, for determining lightfastness, the hue of the colored aluminum may be determined by visual inspection using a gray scale in accordance with the method specified in Japanese Industrial Standard JIS L 0804 "Gray Scale for Color Change and Fading".

[0073] A colored molded article having a colored anodic oxide film of aluminum or an aluminum alloy using the coloring agent of the present invention can be used in a wide variety of products such as aluminum sheet materials or aluminum exteriors.

[0074] The present invention will be described in detail below with reference to examples, but is not limited to the following examples. Unless otherwise specified, reagents used in the synthesis examples, examples, or comparative examples may be those manufactured by Kanto Chemical Co., Ltd., Fujifilm Wako Pure Chemical Corporation, Tokyo Chemical Industries, Ltd., Sigma-Aldrich, Alfa Chemistry, Biosynth, Santa Cruz Biotechnology, etc. In the synthesis examples, the molecular structure of the compound (dye) is identified as follows: １ The measurements were performed using a 1H-NMR spectrometer (JEOL Ltd., JNM-ECZ400S / L1 type), and the NMR measurement data is described along with the experimental results for each synthesis example below.

[0075] [Synthesis Example 1: Dye (A-1)] (Preparation of Diazo Component) 15.2 g of 2-amino-4-nitrophenol-6-sulfonic acid was placed in a reaction vessel, 300 mL of water was added and dispersed, 15.0 g of 98% sulfuric acid (manufactured by Kanto Chemical Co., Ltd.) was added and the mixture was stirred for 2 hours at 5°C or below under an ice bath. After stirring, 11.4 g of 40% sodium nitrite aqueous solution (manufactured by Kanto Chemical Co., Ltd.) was added dropwise to the reaction solution and the mixture was stirred for 3 hours. After stirring, sulfamic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the reaction solution to decompose the excess sodium nitrite and obtain a diazo component solution. (Preparation of Coupler Component) Next, 8.0 g of barbituric acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was placed in a reaction vessel, 180 mL of water was added and dispersed, and then 50 g of 24% sodium hydroxide aqueous solution (manufactured by Kanto Chemical Co., Ltd.) and 3.1 g of sodium carbonate (manufactured by Kanto Chemical Co., Ltd.) were added and dissolved. This solution was stirred at a temperature of 5°C or below under an ice bath to obtain a coupler component solution. (Diazo coupling reaction) The coupler component solution was added to the diazo component solution while it was being stirred, the pH was adjusted to 7.0-8.0, and the mixture was stirred overnight (for 12 hours or more) to carry out the diazo coupling reaction. After stirring, it was confirmed that no diazo product remained by a resorcinol check, and the reaction was terminated. The post-reaction solution was heated to 40°C, 95% sulfuric acid (manufactured by Kanto Chemical Co., Ltd.) was added to adjust the pH to 6.0-6.5, and the precipitated solid was filtered. The obtained solid was dried to obtain a compound (azo dye) represented by the following formula (A-1) as a black powder (yield 20.63 g, yield 87%).

[0076] １ 1H-NMR (400MHz, dimethyl sulfoxide (DMSO)-d ６ ): δ (ppm) = 8.09 (1H), 8.24 (1H), 11.0 (2H)

[0077]

[0078] [Synthesis Example 2: Dye (A-2)] (Preparation of Diazo Component) 9.3 g of 2-aminophenol-4-sulfonic acid was placed in a reaction vessel, 100 mL of water was added and dispersed, and 6.0 g of 98% sulfuric acid (manufactured by Kanto Chemical Co., Ltd.; the product name of the same raw material as in Synthesis Example 1 is omitted below) was added and the mixture was stirred at 5°C or below under an ice bath for 2 hours. After stirring, 8.0 g of 40% sodium nitrite aqueous solution was added dropwise to the reaction solution and the mixture was stirred for 3 hours. After stirring, sulfamic acid was added to the reaction solution to decompose the excess sodium nitrite and obtain the diazo component solution. (Preparation of Coupler Component) Next, 5.8 g of barbituric acid was placed in a reaction vessel, 50 mL of water was added and dispersed, and then 28.1 g of 24% sodium hydroxide aqueous solution and 4.8 g of sodium carbonate were added and dissolved. This solution was stirred at 5°C or below under an ice bath to obtain the coupler component solution. (Diazo Coupling Reaction) The diazotized component solution was added to the coupler component solution while stirring, the pH was adjusted to 8.5-9.0, and the mixture was stirred overnight (approximately 17 hours) to carry out the diazo coupling reaction. After stirring, it was confirmed that no diazotized product remained by a resorcinol check, and the reaction was terminated. The temperature was raised to 40°C, 98% sulfuric acid was added to adjust the pH to 5.5-6.0, and the precipitated solid was filtered. The obtained solid was dried to obtain the compound represented by the following formula (A-2) as a brown powder (yield 13.0 g, yield 88%).

[0079] １ H-NMR (400MHz, D ２ O): δ (ppm) = 7.03 (1H), 7.57 (1H), 8.16 (1H)

[0080]

[0081] [Synthesis Example 3: Dye (A-3)] (Preparation of Diazo Component) 9.4 g of 3-amino-5-sulfosalicylic acid was placed in a reaction vessel, dispersed in 60 mL of water, and 5.0 g of 98% sulfuric acid was added. The mixture was stirred for 2 hours at 5°C or below under an ice bath. After stirring, 6.7 g of 40% sodium nitrite aqueous solution was added dropwise to the reaction mixture over approximately 15 minutes and the mixture was stirred for 3 hours. After stirring, sulfamic acid was added to the reaction mixture to decompose the excess sodium nitrite and obtain the diazo component solution. (Preparation of Coupler Component) Next, 4.7 g of barbituric acid was placed in a reaction vessel, dispersed in 50 mL of water, and then 21.4 g of 24% sodium hydroxide aqueous solution and 3.9 g of sodium carbonate were added and dissolved. This solution was stirred at 5°C or below under an ice bath to obtain the coupler component solution. (Diazo Coupling Reaction) The diazotized component solution was added to the coupler component solution while stirring, the pH was adjusted to 8.0-8.5, and the mixture was stirred overnight to carry out the diazo coupling reaction. After stirring, it was confirmed that no diazotized product remained by a resorcinol check, and the reaction was terminated. The temperature was raised to 40°C, 98% sulfuric acid was added to adjust the pH to 5.0-5.5, and the precipitated solid was filtered. The obtained solid was dried to obtain the compound represented by the following formula (A-3) as a brown powder (yield 13.0 g, yield 94%).

[0082] １ H-NMR (400MHz, D ２ O): δ (ppm) = 8.09 (1H), 8.27 (1H)

[0083]

[0084] [Synthesis Example 4: Dye (A-4)] (Preparation of Diazo Component) 15.2 g of 2-amino-4-nitrophenol-6-sulfonic acid was placed in a reaction vessel, dispersed in 300 mL of water, and 15.0 g of 98% sulfuric acid was added. The mixture was stirred for 2 hours at 5°C or below under an ice bath. After stirring, 11.4 g of 40% sodium nitrite aqueous solution was added dropwise to the reaction mixture and stirred for 3 hours. After stirring, sulfamic acid was added to the reaction mixture to decompose the excess sodium nitrite and obtain the diazo component solution. (Preparation of Coupler Component) Next, 9.3 g of 1,3-dimethylbarbituric acid was placed in a reaction vessel, dispersed in 180 mL of water, and then 50 g of 24% sodium hydroxide aqueous solution and 3.1 g of sodium carbonate were added and dissolved. This solution was stirred at 5°C or below under an ice bath to obtain the coupler component solution. (Diazo Coupling Reaction) The coupler component solution was added to the diazo component solution while stirring, and the pH was adjusted to 7.0-8.0. The mixture was stirred overnight to carry out the diazo coupling reaction. After stirring, it was confirmed that no diazo product remained by resorcinol check, and the reaction was terminated. The temperature was raised to 40°C, and 95% sulfuric acid (manufactured by Kanto Chemical Co., Ltd.) was added to adjust the pH to 6.0-6.5. The precipitated solid was then filtered. The obtained solid was dried to obtain the compound represented by the following formula (A-4) as a red powder (yield 23.5 g, yield 93%).

[0085] １ H-NMR (400MHz, DMSO-d ６ ): δ (ppm) = 8.67 (1H), 8.37 (1H), 3.10 (3H), 3.09 (3H)

[0086]

[0087] [Example 1] <Preparation of colored aluminum> A colored molded body (hereinafter also simply referred to as a colored aluminum plate) having a colored aluminum anodic oxide film was prepared by anodizing an aluminum substrate using the following procedure. The processing time and dye compound concentration were set for the anodizing and dyeing processes. (Degreasing) A degreasing solution was prepared by mixing 150 mL of degreasing agent (manufactured by Okuno Pharmaceutical Co., Ltd., product name: Top ADD-100), 70 mL of 98% sulfuric acid, and 1000 mL of water in a degreasing container. The aluminum substrate for dyeing, cut to an appropriate size, was immersed in the solution and degreasing was performed at 60°C for 3 minutes, after which it was rinsed with water. (Anodizing) An electrolyte solution of 180 g / L was prepared using 98% sulfuric acid in a container for the electrolyte solution. The aluminum substrate was connected to the electrodes of the electrolytic device and immersed in the electrolyte bath at a temperature of 20 ± 1°C (19 to 21°C) and a current density of 1.0 A / dm ２ Anodizing was performed under the following energizing time conditions to produce an anodic oxide film of the following thickness. After oxidation, it was washed with water. Anodizing conditions: energizing for 15 minutes Anodized oxide film thickness: 5 μm (Surface preparation) A surface preparation solution with a concentration of 50 mL / L was prepared using a surface preparation agent (TAC Somar 121, manufactured by Okuno Pharmaceutical Co., Ltd.) and water, and the aluminum substrate was immersed in it at 45°C for 1 minute. After immersion, the aluminum substrate was washed with water. (Dyeing) Using the dye (A-1) obtained in Synthesis Example 1, dyeing aqueous solutions containing the dye at the following concentrations were prepared as dye compositions of the present invention, and the substrates were immersed for the following dyeing times and dyed at a temperature (bath temperature) of 55°C. After dyeing, the aluminum substrate was washed with water. Staining conditions: Dye concentration 2.0% by mass. Staining time: 3 minutes. (Sealing) A 40 mL / L sealing solution was prepared using a sealing agent (Okuno Pharmaceutical Co., Ltd., product name: Topseal H-298) and water, and the sealing treatment was performed at approximately 90°C for 15 minutes. After the sealing treatment, the samples were dried with warm air.

[0088] <Hue Evaluation> The hue of colored aluminum plates colored with dye (A-1) was evaluated visually and with a colorimeter (device name: Konica Minolta spectrophotometer, model: CM-3700A) using CIE L. ＊ a ＊ b ＊ Evaluation was performed using a color system. L ＊ The range is 0 to 100, and a ＊ and b＊ The range was set to -128 to +127. The evaluated hue, L ＊ a ＊ , b ＊ , C ＊ The results are shown in Table 1.

[0089] <Evaluation of Lightfastness> A lightfastness test was performed on colored aluminum plates colored with dye (A-1) using the following method: A xenon fade meter / ATLAS Ci3000 + Xenon Weather Ometer (manufactured by ATLAS) was used, with an irradiance of 300-400 nm and 60 W / m². ２ Under the following conditions: test chamber temperature: 38°C, humidity: 50%, black panel (BP) temperature: 63°C, a colored aluminum plate was irradiated for 50 hours, and the hue and color difference ΔE before and after irradiation were measured using a colorimeter. ＊ ａｂ The color difference ΔE was measured and lightfastness was determined. ＊ ａｂ A smaller value indicates that the color retains its original hue, signifying high lightfastness. In the present invention's lightfastness evaluation method, the following three-stage criteria are used for evaluation, and the results are shown in Table 2. A: 0 ≤ ΔE ＊ ａｂ <2 (particularly good lightfastness) B: 2 ≤ ΔE ＊ ａｂ <5 (Normal level of lightfastness) C: ΔE ＊ ａｂ ≥ 5 (Low light tolerance)

[0090] [Examples 2 to 4] Colored aluminum plates were prepared in the same manner as in Example 1, except that dyes (A-2) to (A-4) were used instead of dye (A-1), and the hue and color difference ΔE were measured visually and with a colorimeter. ＊ ａｂ The results of the evaluation of light resistance are summarized in Tables 1 and 2.

[0091] [Comparative Examples 1 to 6] Instead of pigment (A-1), pigments represented by the following formulas (D-1) to (D-6), which are not part of the present invention, were used to prepare colored aluminum plates in the same manner as in Example 1, and the hue and color difference ΔE were determined by visual inspection and color difference meter measurement. ＊ ａｂThe results of the evaluation of light resistance are summarized in Tables 1 and 2.

[0092]

[0093]

[0094]

[0095]

[0096] By using the coloring agent containing the azo dye and dye composition of this embodiment, a yellow-toned, heavy metal-free colored anodic oxide film can be produced on aluminum. Furthermore, as shown in Table 2, a colored anodic oxide film with superior light resistance compared to those using conventional heavy metal-free dyes can be produced.

[0097] By using a dye composition containing an azo dye according to the present invention, it is possible to obtain a colorant that has excellent lightfastness, does not contain environmentally harmful substances such as heavy metals, and can form a yellow-colored anodic oxide film on an anodized film of aluminum or an aluminum alloy with a single color (single dye), as well as a colored molded article having the yellow-colored anodic oxide film. Furthermore, due to their excellent lightfastness, the azo dye and dye composition of the present invention are expected to have potential as coloring materials for various applications requiring lightfastness and for all types of colored materials (materials used in displays, printing, paints, building materials, resin colorants, image recording, optical and electronic recording, etc.).

Claims

1. An azo dye represented by the following general formula (1). [In the formula (1), R １ represents -OH or -COOX, R ２ to R ５ each independently represent -H, -SO ３ X, -COOX, -NO ２ , -OH, -CH ３ , -CH ２ CH ３ , -SO ２ CH ３ , -SO ２ CH ２ CH ３ or a halogen atom, each X independently represents a non-chromophoric cation, R ６ and R ７ each independently represent a non-chromophoric cation, an alkyl group having 1 to 3 carbon atoms, a cyclohexyl group, -CH ２ OH, -OCH ３ or -OCH ２ CH ３ , Z １ to Z ３ each independently represent an oxygen atom or a sulfur atom.]] 2. In the above general formula (1), R １ ga -OH, R ２ ~R ４ ga-H,-SO ３ X, -COOX, or -NO ２ And R ５ ga -H, and X is H ＋ or Na ＋ The azo dye according to claim 1.

3. In the above general formula (1), R ６ and R ７ H ＋ Na ＋ or -CH ３ Z １ ~Z ３ The azo dye according to claim 1, wherein is an oxygen atom.

4. In acid solution, temperature 19-21℃, current density 1.0A / dm ２ A colored molded body having an aluminum colored anodic oxide film or an aluminum alloy colored anodic oxide film, is made by anodizing an aluminum substrate for 15 minutes with an energizing time, and then coloring it with a dye composition containing 2.0% by mass of an azo dye represented by general formula (1) at a temperature of 50-60°C for 3 minutes. ＊ a ＊ b ＊ Lightness (L) in a color system ＊ ) is 75.00 or more and 90.00 or less, b ＊ The value is between 75.00 and 99.00, and the saturation (C ＊ The azo dye according to claim 1, wherein the ratio is 80.80 or higher.

5. In acid solution, temperature 19-21℃, current density 1.0A / dm ２ An aluminum substrate is anodized for 15 minutes to create an anodic oxide film. This film is then colored using a dye composition containing 2.0% by mass of an azo dye represented by general formula (1) at a temperature of 50-60°C for 3 minutes. The resulting colored molded body having an aluminum colored anodic oxide film or an aluminum alloy colored anodic oxide film is then colored in the lightfastness test according to the Japanese Industrial Standard (JIS H 8685-1) by applying an anodic oxidation treatment to an aluminum substrate to create an anodic oxide film. ＊ ａｂ The azo dye according to claim 1, wherein the (CIE 1976) is 3.00 or less.

6. A dye composition containing an azo dye according to any one of claims 1 to 5.

7. A coloring agent containing the dye composition described in claim 6, for use in an anodic oxide film of aluminum or aluminum alloy as described in Japanese Industrial Standard (JIS H 8601).

8. A colored molded article having a colored anodic oxide film of aluminum or an aluminum alloy using the coloring agent described in claim 7.

9. A method for producing a colored anodic oxide film of aluminum or a colored anodic oxide film of an aluminum alloy, using a dye composition containing 0.02 to 10% by mass of the azo dye described in claim 1.

10. A method for producing an azo dye according to claim 1, wherein the azo dye represented by general formula (1) is obtained by a diazo coupling reaction between a diazotized product obtained by diazotizing a compound represented by the following general formula (1-0) and a compound represented by the following general formula (1-1) and / or a salt thereof. [In equations (1-0) and (1-1), R １ ~R ７ and Z １ ~Z ３ This is the same as the definition described in general formula (1) above.

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