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 red to reddish purple 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] The present invention relates to an azo dye, a dye composition suitable for use as a coloring agent for anodized films of aluminum or aluminum alloys, and a colored molded article having a colored anodized film produced using the coloring agent. Furthermore, the invention relates to a method for producing a colored anodized film 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 and have a variety of hues.

[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 lightfastness and 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. 2580867 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 of the objects of the present invention is to provide an azo dye capable of forming, on the surface of an anodized film of aluminum or an aluminum alloy, a colored anodized film that is excellent in light resistance, does not contain environmentally hazardous substances such as heavy metals, is a monochromatic color (single pigment), and exhibits a red to reddish purple hue (including red or reddish purple with different shades and brightness, pink, red tinged with yellow, orange or brown (including reddish brown), and red tinged with purple and blue), 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 aforementioned problems, and is constituted by the following contents.

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

[0010]

[0011] [In formula (1), R １ represents -OH or -COOX, and R ２ to R ６ each independently represent -H, -NO ２ , -NH ２ , -OH, -CH ３ , -CH ２ CH ３ , -CN, -COOX, -SO ３ X, -SO ２ CH ３ , -SO ２ CH ２ CH ３ or a halogen atom, and R ７ is -OH or -NH２ This represents X, where each X independently represents a non-chromogenic cation.

[0012] [2] In the above general formula (1), R １ ga -OH, R ２ and R ３ These are, independently, -H, -NO ２ or -SO ３ X is R ４ The azo dye described in [1] is -H.

[0013] [3] In the above general formula (1), R ５ and R ６ ga -H, R ７ The azo dye according to [1] or [2], wherein the OH group is -OH.

[0014] [4] In the above general formula (1), R ２ ~R ６ At least two of them are -NO ２ , -SO ３ An azo dye according to any one of [1] to [3], wherein X is a halogen atom.

[0015] [5] In the above general formula (1), X is H ＋ or Na ＋ The azo dye described in any of [1] to [4].

[0016] [6] 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 with an energizing time, and then coloring the aluminum substrate with a dye composition containing 2.0% by mass of the azo dye represented by the general formula (1) at a temperature of 50-60°C for 3 minutes. ＊ a ＊ b ＊ Lightness (L) in a color system ＊ ) is between 46.50 and 60.00, and saturation (C ＊ An azo dye according to any one of [1] to [5], wherein the ratio is 47.00 or more and 60.00 or less.

[0017] [7] 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 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 An azo dye according to any one of [1] to [6], wherein the (CIE 1976) is 5.00 or less.

[0018] A dye composition containing an azo dye as described in any of [8], [1], to [7].

[0019] A coloring agent containing the dye composition described in [9] and [8], which is used for anodic oxide coatings of aluminum or aluminum alloys as described in Japanese Industrial Standard (JIS H 8601).

[0020] A colored molded article having a colored anodic oxide film of aluminum or an aluminum alloy, using the coloring agents described in

[10] and [9].

[0021] 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 in which the concentration of the azo dye described in any of [1] to [7] is 0.02 to 10% by mass.

[0022] A method for producing an azo dye according to any one of

[12] , [1] to [7], 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.

[0023]

[0024] [In equations (1-0) and (1-1), R １ ~R ７ And X is the same as the definition described in the general formula (1) above.

[0025] The present invention provides an azo dye capable of forming a 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 available in a single color (single dye) ranging from red to reddish-purple (including red or reddish-purple of varying shades and brightness, pink, yellow, orange, or brownish-red (including reddish-brown), and purple or bluish-red), 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.

[0026] 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.

[0027] In general formula (1), "X", "-SO ３ The "non-chromogenic cation" represented by "X" in "-COOX" 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, H ＋ or Na ＋ is more preferable.

[0028] In general formula (1), R ２ to R ６ 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.

[0029] In general formula (1), R １ represents -OH or -COOX, and is preferably -OH.

[0030] In general formula (1), R ２ to R ６ are each independently -H, -NO ２ , -NH ２ , -OH, -CH ３ , -CH ２ CH ３ , -CN, -COOX, -SO ３ X, -SO ２ CH ３ , -SO ２ CH ２ CH ３ or a halogen atom. In general formula (1), at least two of R ２ to R ６ may be -NO ２ , -SO ３ X or a halogen atom. In general formula (1), R ２ and R ３ are each independently -H, -NO ２ or -SO ３ X is preferable, R ４ is preferably -H. In general formula (1), R ３ is more preferably -NO ２ .

[0031] In general formula (1), R ５ and R ６ is preferably -H. In general formula (1), R ７represents -OH or -NH ２ , and is preferably -OH.

[0032] Specific examples of the dye of the present invention represented by general formula (1) (azo dye (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-[NS] as shown in the following general formula (2), the moiety represented by [AP] is R as shown in the following general formula [AP] １ to R ４ is a phenyl group having. Further, the moiety represented by [NS] in formula (2) is R as shown in the following general formula [NS] ５ to R ７ and -SO ３ is a naphthyl group having X. In formulas [AP] and [NS], "*" each represents a bonding site to the azo group "-N=N-".

[0033]

[0034] [In formula (AP) and formula (NS), R １ to R ７ and X have the same definitions as those described in the above general formula (1). ]

[0035] In general formula (1), specific examples of the group represented by the above general formula [AP] are shown in the following formulas (AP1) to (AP10), but the present invention is not limited thereto. Further, specific examples of the group represented by the above general formula [NS] are shown in the following formulas (NS1) to (NS6), but the present invention is not limited thereto. Further, in the specific examples of the groups below, -SO ３ "X" in X or -COOX is exemplified by "H" or "Na", but is not limited thereto.

[0036]

[0037]

[0038] 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 (M-1) to (M-27), 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.

[0039]

[0040]

[0041]

[0042]

[0043]

[0044] 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 (M-3) below can be represented by the following formulas (M-3-1), (M-3-2), (M-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.

[0045]

[0046] 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.

[0047]

[0048] [In equations (1-0) and (1-1), R １ ~R ７ And X is the same as the definition described in the general formula (1) above.

[0049] 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.

[0050] 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)).

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] The electrolytic conditions for coloring in this invention may be either DC or AC electrolysis, with DC electrolysis being preferred. The current density is 0.1 A / dm ２ Above, 0.2A / dm ２ Above, 0.5A / dm ２ The above is sufficient, and 10 A / dm ２ Below, 7A / dm ２ Below, 5A / dm２ 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.

[0061] 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.

[0062] 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.

[0063] 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 by color system (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 for a certain period of time using a test machine that simulates sunlight including ultraviolet light, and measuring the numerical changes in hue, color, etc., and the color difference of the colored aluminum before and after the test. 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)

[0064] 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 in the red to reddish-purple range, and can represent red or reddish-purple with different shades and brightness, pink, yellowish-orange or brownish-red (including reddish-brown and reddish-brown), purple or bluish-red (reddish-purple, bluish-red), or similar colors thereto, or dull colors obtained by mixing these. More specifically, the above-mentioned reddish colors that can be generally distinguished by the human eye are, for example, the colors listed in the Japanese Industrial Standard JIS Z 8102:2001 "Color Names of Object Colors", and may be colors with adjusted levels of lightness and saturation. The color names may include Munsell color system names, Western color names such as English, common names listed in the JIS standard, or traditional Japanese color names (such as dye names for immersion dyeing and printing). For example, in the red color family, examples include red, crimson, vermilion, golden red, scarlet, peony red, rose red, madder red, ruby ​​red, carmine, rose, mordant red, 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.

[0065] 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 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, using an aluminum substrate anodized for 15 minutes. ＊ a ＊ b ＊ Lightness (L) in a color system ＊ ) is between 46.50 and 60.00, and the saturation (C ＊ It is preferable that the value is between 47.00 and 60.00. 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 5.00 or less. The lower limit of the color difference is not particularly limited, and a lower value is preferable, but it may be 1.00 or more. 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".

[0066] A colored molded article having a colored anodic oxide film of anodized aluminum or 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.

[0067] 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, and others.

[0068] [Synthesis Example 1: Dye (M-1)] (Preparation of Diazo Component) 3.0 g of 2-amino-4-nitrophenol (manufactured by Tokyo Chemical Industry Co., Ltd.) was placed in a reaction vessel, 60 mL of water was added and dispersed, and 5.0 g of 98% sulfuric acid (manufactured by Kanto Chemical Co., Ltd.) was added and stirred for 2 hours at 5°C or below under an ice bath. After stirring, 3.8 g of 40% sodium nitrite aqueous solution (manufactured by Kanto Chemical Co., Ltd.) was added dropwise to the reaction solution and 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 diazo component solution 1. (Preparation of Coupler Component) Next, 7.6 g of 2-naphthol-3,6 disulfonic acid (manufactured by Sigma-Aldrich) was placed in a reaction vessel, 60 mL of water was added and dispersed, and then 18 g of 24% sodium hydroxide aqueous solution (manufactured by Kanto Chemical Co., Ltd.) and 1.0 g of sodium carbonate (manufactured by Kanto Chemical Co., Ltd.) were added and dissolved. This solution was stirred under an ice bath at a temperature of 5°C or below to obtain a coupler component solution. (Diazo coupling reaction) The diazo component solution 1 was added to the stirred coupler component solution, the pH was adjusted to 8.0-9.0, 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 temperature was raised 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 represented by the following formula (M-1) as a black powder (yield 8.4 g, yield 90%).

[0069]

[0070] [Synthesis Example 2: Dye (M-2)] In the same manner as in [Synthesis Example 1], except that 3.0 g of 2-amino-4-nitrophenol in (preparation of diazo component) was replaced with 4.0 g of picramic acid, the diazo component was prepared, the coupler component was prepared, and the diazo coupling reaction was carried out (the company name of the product using the same raw materials as in the above synthesis example is omitted), and a compound represented by the following formula (M-2) was obtained as a black powder (yield 7.5 g, yield 83%).

[0071]

[0072] [Synthesis Example 3: Dye (M-3)] In the same method as in [Synthesis Example 1], except that 3.0 g of 2-amino-4-nitrophenol in (preparation of diazo component) was replaced with 5.1 g of 2-amino-4-nitrophenol-6-sulfonic acid, the diazo component was prepared, the coupler component was prepared, and the diazo coupling reaction was carried out to obtain a compound represented by the following formula (M-3) as a black powder (yield 8.2 g, yield 80%).

[0073]

[0074] [Comparative Compound Synthesis Example 1: Dye (D-1)] Except that the 3.0 g of 2-amino-4-nitrophenol in (preparation of diazo component) was replaced with 5.1 g of 2-amino-4-nitrophenol-6-sulfonic acid, and the 7.6 g of 2-naphthol-3,6-disulfonic acid in (preparation of coupler component) was replaced with 4.4 g of 2-naphthol-7-sulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), the diazo component preparation, coupler component preparation, and diazo coupling reaction were carried out in the same manner as in Synthesis Example 1, and a comparative compound represented by the following formula (D-1) was obtained as a black powder (yield 7.6 g, yield 84%).

[0075]

[0076] [Comparative Example Compound Synthesis Example 2: Dye (D-2)] Except that the 3.0 g of 2-amino-4-nitrophenol in (preparation of diazo component) was replaced with 4.0 g of picramic acid in (preparation of coupler component) in [Synthesis Example 1], and the 7.6 g of 2-naphthol-3,6-disulfonic acid in (preparation of coupler component) was replaced with 4.4 g of 2-naphthol-6-sulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), the diazo component preparation, coupler component preparation, and diazo coupling reaction were carried out in the same manner as in Synthesis Example 1, and a compound represented by the following formula (D-2) was obtained as a black powder (yield 6.3 g, yield 71%).

[0077]

[0078] [Comparative Example Compound Synthesis Example 3: Dye (D-3)] Except that in [Synthesis Example 1], 3.0 g of 2-amino-4-nitrophenol in (preparation of diazo component) was replaced with 5.1 g of 2-amino-4-nitrophenol-6-sulfonic acid, and 7.6 g of 2-naphthol-3,6-disulfonic acid in (preparation of coupler component) was replaced with 4.4 g of 2-naphthol-6-sulfonic acid, the same method as in Synthesis Example 1 was used to prepare the diazo component, prepare the coupler component, and carry out the diazo coupling reaction to obtain a compound represented by the following formula (D-3) as a black powder (yield 7.6 g, yield 74%).

[0079]

[0080] [Comparative Example Compound Synthesis Example 4: Dye (D-4)] Except that in [Synthesis Example 1], 3.0 g of 2-amino-4-nitrophenol in (preparation of diazo component) was replaced with 4.0 g of picramic acid, and 7.6 g of 2-naphthol-3,6-disulfonic acid in (preparation of coupler component) was replaced with 4.4 g of 2-naphthol-7-sulfonic acid, the same method as in Synthesis Example 1 was used to prepare the diazo component, prepare the coupler component, and carry out the diazo coupling reaction to obtain a compound represented by the following formula (D-4) as a black powder (yield 5.3 g, yield 52%).

[0081]

[0082] [Comparative Example Compound Synthesis Example 5: Dye (D-5)] In the above [Synthesis Example 1], except that 7.6 g of 2-naphthol-3,6-disulfonic acid in (preparation of coupler component) was replaced with 4.4 g of 2-naphthol-7-sulfonic acid, the diazo component was prepared, the coupler component was prepared, and the diazo coupling reaction was carried out in the same manner as in Synthesis Example 1, and a compound represented by the following formula (D-5) was obtained as a black powder (yield 6.32 g, yield 77%).

[0083]

[0084] [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 (M-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.

[0085] <Hue Evaluation> The hue of colored aluminum plates colored with pigment (M-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.

[0086] <Evaluation of Lightfastness> A lightfastness test was conducted on colored aluminum plates colored with dye (M-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. ＊ The ab values ​​were measured and the lightfastness was determined. Color difference ΔE ＊ A smaller value of ab 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)

[0087] [Examples 2 and 3] Colored aluminum plates were prepared in the same manner as in Example 1, except that dyes (M-2) and (M-3) were used instead of dye (M-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.

[0088] [Comparative Examples 1 to 7] Instead of pigment (M-1), pigments not belonging to the present invention, represented by formulas (D-1) to (D-5) and below (D-6) and (D-7), were used to prepare colored aluminum plates in the same manner as in Example 1, and the hue and color difference ΔE were measured visually and with a colorimeter. ＊ ａｂThe results of the evaluation of light resistance are summarized in Tables 1 and 2.

[0089]

[0090]

[0091]

[0092] By using the coloring agent containing the azo dye and dye composition of this embodiment, a colored anodic oxide film can be produced on aluminum that is red to purple (including bluish-red and pink), and does not contain heavy metals such as chromium. 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.

[0093] By using the dye composition containing the azo dye according to the present invention, it is possible to obtain a coloring agent that has excellent lightfastness, does not contain environmentally harmful substances such as heavy metals, and can form a reddish (including reddish-purple, bluish-purple, etc.) colored film on an anodized film of aluminum or aluminum alloy with a single color (single dye), and a colored molded article having the reddish colored anodized film. Furthermore, because the azo dye and dye composition of the present invention have excellent lightfastness, they are expected to have potential as coloring materials for various applications requiring lightfastness and for all types of colored materials (materials used in markings, printing, paints, building materials, resin coloring agents, 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, and R ２ to R ６ each independently represent -H, -NO ２ , -NH ２ , -OH, -CH ３ , -CH ２ CH ３ , -CN, -COOX, -SO ３ X, -SO ２ CH ３ , -SO ２ CH ２ CH ３ or a halogen atom, R ７ represents -OH or -NH ２ , and X each independently represent a non-chromophoric cation.]] 2. In the above general formula (1), R １ ga -OH, R ２ and R ３ These are, independently, -H, -NO ２ or -SO ３ X is R ４ The azo dye according to claim 1, wherein the color is H.

3. In the above general formula (1), R ５ and R ６ ga -H, R ７ The azo dye according to claim 1, wherein the OH group is -OH.

4. In the general formula (1) above, R ２ ~R ６ At least two of them are -NO ２ , -SO ３ The azo dye according to claim 1, wherein X is a halogen atom.

5. In the general formula (1) above, X is H ＋ or Na ＋ The azo dye according to claim 1.

6. 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 between 46.50 and 60.00, and saturation (C ＊ The azo dye according to claim 1, wherein the ratio is 47.00 or more and 60.00 or less.

7. 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 5.00 or less.

8. A dye composition containing an azo dye according to any one of claims 1 to 7.

9. A coloring agent containing the dye composition described in claim 8, for use in an anodic oxide film of aluminum or aluminum alloy as described in Japanese Industrial Standard (JIS H 8601).

10. A colored molded article having a colored anodic oxide film of aluminum or an aluminum alloy using the coloring agent described in claim 9.

11. 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 in which the concentration of the azo dye described in claim 1 is 0.02 to 10% by mass.

12. 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 X is the same as the definition described in the general formula (1) above.

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