Anodically oxidized dyes, process for their preparation and use

Abstract

The application discloses an anodic oxidation dye and a preparation method and application thereof, and relates to the technical field of dyes. The application comprises the following raw materials in mass parts: 400-700 parts of azo dye, 20-50 parts of metal complexing agent, 200-300 parts of filling agent, 80-120 parts of fixing agent solution, 10-30 parts of dispersing agent, 20-50 parts of pH stabilizer, 70-80 parts of synergist, and 5-10 parts of anti-knot agent. The metal complexing agent is any one of disodium amino triacetate, disodium ethylenediamine tetraacetate and trisodium hydroxyethyl ethylenediamine triacetate. The metal complexing agent, the fixing agent solution and the synergist are introduced, so that the weather resistance, corrosion resistance, mildew resistance and adhesion stability of the anodic oxidation dye are effectively improved. Therefore, the anodic oxidation dye has a more extensive application prospect in the fields of aluminum building materials, aluminum household appliances and aluminum automobile parts.

Description

Technical Field

[0001] This invention relates to the field of dye technology, specifically to an anodized dye, its preparation method, and its application. Background Technology

[0002] Anodizing aluminum alloys creates a corrosion-resistant, highly absorbent, and dyeable oxide film on their surface, making it a common surface decoration process. However, dyeing aluminum alloy surfaces using acidic organic dyes can lead to dye group structure breakage under outdoor natural ultraviolet radiation and high temperature and humidity conditions, resulting in dye discoloration and limiting the service life of the dyed aluminum alloy workpiece.

[0003] To address this issue, relevant technical personnel have proposed several optimization solutions. For example, patent CN117702215A discloses an aluminum anodizing process to improve the weather resistance of dyes. This technology adds an extra post-treatment step after the traditional closed process. It uses a bath solution with fatty alcohol sulfate and sodium dodecyl sulfonate as the main components to perform a secondary treatment on the workpiece for 10-20 minutes in a medium-high temperature environment. By filling the pores of the oxide film with surface-active components and enhancing the adsorption stability of dye molecules, the UV resistance and damp heat resistance of the dyed layer are improved to a certain extent.

[0004] However, such solutions still make the process more complicated in practical applications. Furthermore, anodic dyes have the following performance defects during use: First, they lack chemical corrosion resistance, easily discoloring and peeling when exposed to acidic or alkaline media; second, they have poor mildew resistance, easily growing mold in humid and dark environments, leading to mold spots and discoloration on the dyed layer, affecting appearance and durability; third, their adhesion stability is insufficient, and under long-term stress or alternating hot and cold cycles, the bonding force between the dyed layer and the oxide film weakens, easily resulting in peeling and flaking. Therefore, the weather resistance, corrosion resistance, mildew resistance, and adhesion stability of existing anodic dyes still need improvement. Summary of the Invention

[0005] The purpose of this invention is to provide an anodized dye, its preparation method, and its application, thereby solving the following technical problems: Existing anodizing dyes still suffer from poor weather resistance, corrosion resistance, mildew resistance, and adhesion stability.

[0006] The objective of this invention can be achieved through the following technical solutions: An anodizing dye comprises the following raw materials in parts by weight: 400-700 parts azo dye, 20-50 parts metal complexing agent, 200-300 parts filler, 80-120 parts fixing agent solution, 10-30 parts dispersant, 20-50 parts pH stabilizer, 70-80 parts synergist, and 5-10 parts anti-caking agent; The synergist is prepared by first loading zinc magnesium carbonate / basic carbonate onto wollastonite powder, then treating it with silane coupling agent KH-550, coating it with silica, calcining it at 550°C, cooling it, grinding it, and passing it through a 300-400 mesh sieve. The fixing agent solution is prepared from hydroxyethyl acrylate, methyl methacrylate, silane coupling agent KH-570, fatty alcohol polyoxyethylene ether AEO-9, light stabilizer UV-327, ammonium persulfate, and hydroquinone.

[0007] Preferably, the synergist is prepared by the following method: A1: Add magnesium nitrate aqueous solution to zinc nitrate aqueous solution and stir well, then add sodium carbonate aqueous solution and stir for 20-30 min to obtain a mixed suspension; A2: Add wollastonite powder to deionized water and stir at 60℃ for 30-40 min. Then adjust the pH to 9-10, raise the temperature to 83-87℃ and drop in the mixed suspension. Then react at 83-87℃ for 2 h. Finally filter, wash, dry and grind to obtain precursor powder. A3: Add tetraethyl orthosilicate to anhydrous ethanol and stir well. Then add deionized water and ammonia and stir for 6-7 hours to obtain silica sol. A4: Add deionized water and silane coupling agent KH-550 to anhydrous ethanol and stir for 40-60 min. Then add precursor powder and ultrasonically disperse for 30-40 min. After heating to 45℃, add silica sol dropwise and stir for 4-5 h. After filtration, washing, and drying, heat to 550℃ in a muffle furnace at 5℃ / min and hold for 2-3 h. After cooling, grind and pass through a 300-400 mesh sieve to obtain the synergist.

[0008] Preferably, the volume ratio of the zinc nitrate aqueous solution, magnesium nitrate aqueous solution, and sodium carbonate aqueous solution in A1 is 140:60:400-410; The concentration of the zinc nitrate aqueous solution described in A1 is 0.5 mol / L; The concentration of the magnesium nitrate aqueous solution described in A1 is 0.5 mol / L; The concentration of the sodium carbonate aqueous solution described in A1 is 1 mol / L; The ratio of deionized water, wollastonite powder, and mixed suspension described in A2 is 400 mL: 40 g: 600-610 mL.

[0009] Preferably, the volume ratio of anhydrous ethanol, tetraethyl orthosilicate, deionized water, and ammonia in A3 is 82-83:8:8:2; The mass fraction of ammonia in A3 is 28%; The ratio of anhydrous ethanol, deionized water, silane coupling agent KH-550, precursor powder, and silica sol described in A4 is 260mL:40mL:4mL:70-80g:100mL.

[0010] Preferably, the method for preparing the fixing agent solution is as follows: B1: Add ammonium persulfate to deionized water and stir well to obtain an initiator solution; B2: Add anhydrous ethanol, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent KH-570, fatty alcohol polyoxyethylene ether AEO-9, and light stabilizer UV-327 to deionized water and stir at 65°C for 30-40 min. Then add initiator solution 1 and stir for 15-20 min. Next, raise the temperature to 70°C and dropwise add initiator solution 2 and stir for 90-100 min. After cooling to 35-40°C, add hydroquinone and stir for 5-10 min. Finally, adjust the pH to 7.0-7.5 to obtain the fixing agent solution.

[0011] Preferably, the mass ratio of deionized water to ammonium persulfate in B1 is 10-12:0.5-0.6; The mass ratio of deionized water, anhydrous ethanol, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent KH-570, fatty alcohol polyoxyethylene ether AEO-9, light stabilizer UV-327, initiator solution 1, initiator solution 2, and hydroquinone in B2 is 40-50:20-25:10-12:20-25:8-10:0.5:0.8-1.2:3-3.5:7-9:0.1.

[0012] Preferably, the dispersant is any one of fatty alcohol polyoxyethylene ether AEO-9 and AEO-10; The pH stabilizer is a mixture of sodium dihydrogen phosphate and disodium hydrogen phosphate in a mass ratio of 3:1.

[0013] Preferably, the azo dye is any one of Acid Black ATT-M, Acid Blue 29, and Acid Yellow 99; The metal complexing agent is any one of disodium aminotriacetate, disodium ethylenediaminetetraacetate, and trisodium hydroxyethylethylenediaminetriacetate. The filler is either anhydrous sodium sulfate or anhydrous potassium sulfate; The anti-caking agent is any one of fumed silica, magnesium silicate, and magnesium stearate.

[0014] Preferably, the method for preparing anodized dye includes the following steps: S1: Mix the color-fixing agent solution, dispersant, and pH stabilizer for 15-20 minutes, then adjust the pH to 5-6 with a 10% sodium hydroxide aqueous solution to obtain the premix. S2: Add metal complexing agent and filler to azo dye, then add premix while stirring, then add synergist and mix at 300 r / min for 20-30 min, then disperse at 1000 r / min at 40-50℃ for 30-40 min, then heat treat at 55℃ for 90-100 min, finally add anti-caking agent and crush and pass through a 200 mesh sieve to obtain anodized dye.

[0015] Application of an anodizing dye in aluminum building materials, aluminum home appliances, and aluminum automotive parts.

[0016] The beneficial effects of this invention are: This invention provides an anodized dye, its preparation method, and its application. The invention improves the weather resistance, corrosion resistance, mildew resistance, and adhesion stability of the anodized dye through the following method.

[0017] (1) The metal complexing agents of this invention are all aminocarboxylic acid chelating agents, which can form stable five- or six-membered ring complexes with zinc ions, magnesium ions, iron ions, etc., to prevent free metal ions from reacting with azo dye molecules to form precipitates or weakly catalyze the decomposition of dyes. At the same time, they reduce the probability of metal ions participating in photo-oxidation reactions, indirectly delaying the photo-fading of dyes and helping to improve weather resistance. The metal complexing agent forms a dye-complexing agent-aluminum ion bridging structure by chelating aluminum ions on the surface of the oxide film, which enhances the chemical bonding force between the dye and the oxide film. This bridging structure can reduce the interfacial gap between the dye and the oxide film, alleviate the interfacial stress generated by thermal expansion and contraction during temperature cycling, and thus maintain the adhesion stability after temperature cycling. At the same time, the complexing agent can chelate a small amount of free zinc and magnesium ions in the system, promote their more uniform bonding with the oxide film, and indirectly improve the adhesion stability. Metal complexing agents can chelate aluminum ions dissolved from the oxide film in corrosive media, reducing the damage to the dye structure caused by secondary reactions; at the same time, they can improve the fixation of dye in the pores of the oxide film, reducing the loss of dye during salt spray, acid and alkali treatment; in addition, the complexed metal ions can slightly reduce the direct contact between the corrosive media and dye molecules, helping to delay the corrosion and degradation of the dye.

[0018] (2) The light stabilizer UV-327 in the fixing agent solution of the present invention can absorb ultraviolet light and partially quench the active free radicals generated by ultraviolet light excitation, thereby reducing the direct damage of ultraviolet radiation to the dye; the hydroxyethyl acrylate-methyl methacrylate copolymer can form a thin polymer film in the micropores of the alumina film, which can coat the dye molecules, reduce the probability of direct ultraviolet light irradiation of the dye, and at the same time reduce the contact efficiency between oxygen, moisture and dye in the environment, thus slowing down the synergistic occurrence of photo-oxidative degradation; the siloxane coupling agent KH-570 in the fixing agent hydrolyzes to generate Si-OH, which can form Si-O-Al covalent bonds with Al-OH on the surface of the alumina film, and crosslink with SiO-OH on the surface of the synergist, thereby enhancing the bonding force between the organic film and the oxide film and the synergist, reducing the loss of the organic film due to the volume change caused by ultraviolet irradiation, and continuously playing a protective role. Acrylic ester copolymers possess a certain degree of hydrophobicity. After film formation, they can create a hydrophobic layer on the surface of the alumina film and within its micropores, reducing the adsorption and retention of moisture in the membrane pores and minimizing the humid environment conducive to mold growth. Simultaneously, small amounts of organic components readily utilized by mold are encapsulated by the polymer membrane, restricting mold access to nutrients and further inhibiting mold growth. The Si-O-Al covalent bonds formed by the silane coupling agent KH-570 enhance interfacial adhesion. The hydroxyl groups of hydroxyethyl acrylate increase the hydrogen bonding of the polymer chains, giving the copolymer segments a certain degree of flexibility. During cold and hot cycles, this buffers the internal stress caused by thermal expansion and contraction, reducing the tendency for film cracking and interfacial debonding. The polymer membrane can fill some of the pores in the alumina film, forming an organic barrier layer that delays the penetration of corrosive media such as chloride ions, hydrogen ions, and hydroxide ions. Synergistically with the inorganic synergist, it constructs an organic-inorganic hybrid barrier system, complementing the flexibility of the organic membrane and the density of the inorganic membrane, thus improving the overall protective effect.

[0019] (3) The silica and zinc magnesium carbonate in the synergist of this invention can scatter ultraviolet light; the high aspect ratio wollastonite is fibrous and can form an interwoven network in the dye coating, improving the scattering efficiency of ultraviolet light and indirectly reducing the probability of ultraviolet light penetrating to the dye molecules, thus helping to inhibit the photodegradation of the dye. The zinc magnesium carbonate in the synergist can dissolve slightly under the action of humid or corrosive media, releasing a low concentration of zinc ions, which have weak antibacterial activity and can interfere with the metabolism and reproduction of mold; the inorganic particles can fill the voids inside the dye coating, reduce the attachment sites of mold on the surface of the specimen, and help inhibit mold growth. Wollastonite fibers can form a three-dimensional cross-linked network in the dye coating, enhancing the coating's mechanical strength and effectively dispersing localized internal stresses generated by thermal cycling, thus preventing coating cracking and peeling caused by stress concentration. Simultaneously, zinc magnesium carbonate / basic carbonate, silica, and wollastonite are all inorganic phases with excellent thermal stability, exhibiting minimal volume change within a temperature range of -20℃ to 80℃, stabilizing the microstructure of the dye system. The silica coating layer, a dense inorganic shell, buffers the volume change stress caused by temperature variations, reducing micro-cracking between particles and the coating substrate, and improving adhesion stability. The wollastonite fiber network, silica coating layer, and zinc magnesium carbonate particles fill the internal pores of the dye coating, increasing its density and reducing the penetration path of corrosive media. Zinc magnesium carbonate undergoes slight dissolution in corrosive media, generating hydroxides such as magnesium hydroxide, which deposit at micro-defects in the coating, partially blocking corrosion channels, slowing further corrosion development, and improving corrosion resistance.

[0020] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The embodiments described below are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1: A method for preparing an anodized dye is as follows: S1: Add 60 mL of 0.5 mol / L magnesium nitrate aqueous solution to 140 mL of 0.5 mol / L zinc nitrate aqueous solution and stir for 20 min. Then add 400 mL of 1 mol / L sodium carbonate aqueous solution and stir for 20 min to obtain a mixed suspension. S2: Add 40g of wollastonite powder (height-to-diameter ratio 11-17:1) to 400mL of deionized water and stir at 60℃ for 30min. Then adjust the pH of the slurry to 9 with 0.1mol / L sodium hydroxide aqueous solution, then heat to 83℃ and add 600mL of mixed suspension dropwise at 2mL / min while stirring at 800r / min. Maintain the pH at 10 with 0.05mol / L nitric acid aqueous solution. Then react at 83℃ for 2h. After that, filter and wash the filter cake with hot deionized water at 60℃ until the conductivity of the filtrate is 50μS / cm. Finally, dry at 110℃ for 12h and grind to obtain the precursor powder. S3: Add 8 mL of tetraethyl orthosilicate to 82 mL of anhydrous ethanol and stir for 10 min. Then add 8 mL of deionized water and 2 mL of 28% ammonia water and stir for 6 h to obtain silica sol. S4: Add 40 mL of deionized water and 4 mL of silane coupling agent KH-550 to 260 mL of anhydrous ethanol and stir for 40 min. Then add 70 g of precursor powder and ultrasonically disperse for 30 min. Then heat to 45 °C and add 100 mL of silica sol dropwise at 1 mL / min while stirring at 600 r / min. Then stir at 45 °C for 4 h. Then filter and wash the filter cake three times with anhydrous ethanol. Dry at 80 °C for 6 h. Then heat to 550 °C in a muffle furnace at 5 °C / min and keep at that temperature for 2 h. After cooling, grind and pass through a 300 mesh sieve to obtain the synergist. S5: Add 0.5g of ammonium persulfate to 10g of deionized water and stir for 20min to obtain an initiator solution; S6: Add 20g anhydrous ethanol, 10g hydroxyethyl acrylate, 20g methyl methacrylate, 8g silane coupling agent KH-570, 0.5g fatty alcohol polyoxyethylene ether AEO-9, and 0.8g light stabilizer UV-327 to 40g deionized water and stir at 65℃ for 30min. Then add 3g initiator solution and stir for 15min. Then raise the temperature to 70℃ at 1℃ / min. Then add 7g initiator solution dropwise at 0.1g / min and stir at 70℃ for 90min. After cooling to 35℃, add 0.1g hydroquinone and stir for 5min. Finally, adjust the pH to 7 with 10% sodium hydroxide aqueous solution to obtain the fixing agent solution. S7: Mix 80g of color-fixing agent solution, 10g of fatty alcohol polyoxyethylene ether AEO-9, 15g of sodium dihydrogen phosphate, and 5g of disodium hydrogen phosphate and stir for 6 to obtain a premix. S8: Add 20g disodium aminotriacetate and 200g anhydrous sodium sulfate to 400g Acid Black ATT-M. Then, while stirring at 100r / min, add 110g of premix at 2g / min. Then, add 70g of synergist in 4 portions and mix at 300r / min for 20min. Then, disperse at 1000r / min at 40℃ for 30min. Then, heat treat at 55℃ for 90min. Finally, add 5g of fumed silica, pulverize, and pass through a 200-mesh sieve to obtain anodized dye.

[0023] Example 2: A method for preparing an anodized dye is as follows: S1: Add 60 mL of 0.5 mol / L magnesium nitrate aqueous solution to 140 mL of 0.5 mol / L zinc nitrate aqueous solution and stir for 25 min. Then add 400 mL of 1 mol / L sodium carbonate aqueous solution and stir for 25 min to obtain a mixed suspension. S2: Add 40g of wollastonite powder (height-to-diameter ratio 11-17:1) to 400mL of deionized water and stir at 60℃ for 35min. Then adjust the pH of the slurry to 9.5 with 0.1mol / L sodium hydroxide aqueous solution, then heat to 85℃ and add 600mL of mixed suspension dropwise at 2mL / min while stirring at 800r / min. Maintain the pH at 10.3 with 0.05mol / L nitric acid aqueous solution. Then react at 85℃ for 2h. After that, filter and wash the filter cake with hot deionized water at 60℃ until the conductivity of the filtrate is 77μS / cm. Finally, dry at 110℃ for 13.5h and grind to obtain the precursor powder. S3: Add 8 mL of tetraethyl orthosilicate to 82 mL of anhydrous ethanol and stir for 15 min. Then add 8 mL of deionized water and 2 mL of 28% ammonia water and stir for 6.5 h to obtain silica sol. S4: Add 40 mL of deionized water and 4 mL of silane coupling agent KH-550 to 260 mL of anhydrous ethanol and stir for 50 min. Then add 75 g of precursor powder and ultrasonically disperse for 35 min. Then heat to 45 °C and add 100 mL of silica sol dropwise at 1 mL / min while stirring at 600 r / min. Then stir at 45 °C for 4.5 h. Then filter and wash the filter cake 4 times with anhydrous ethanol. Dry at 80 °C for 7 h. Then heat to 550 °C in a muffle furnace at 5 °C / min and hold for 2.5 h. After cooling, grind and pass through a 300 mesh sieve to obtain the synergist. S5: Add 0.55g of ammonium persulfate to 11g of deionized water and stir for 25min to obtain an initiator solution; S6: Add 23g anhydrous ethanol, 11g hydroxyethyl acrylate, 22g methyl methacrylate, 9g silane coupling agent KH-570, 0.5g fatty alcohol polyoxyethylene ether AEO-9, and 1g light stabilizer UV-327 to 45g deionized water and stir at 65℃ for 35min. Then add 3.3g initiator solution and stir for 18min. Then raise the temperature to 70℃ at 1℃ / min. Then add 8g initiator solution dropwise at 0.1g / min and stir at 70℃ for 95min. After cooling to 38℃, add 0.1g hydroquinone and stir for 8min. Finally, adjust the pH to 7.3 with 10% sodium hydroxide aqueous solution to obtain the fixing agent solution. S7: Mix 100g of color-fixing agent solution, 20g of fatty alcohol polyoxyethylene ether AEO-10, 27g of sodium dihydrogen phosphate and 9g of disodium hydrogen phosphate and stir for 18min. Then adjust the pH to 5.5 with a 10% sodium hydroxide aqueous solution to obtain the premix. S8: Add 35g of disodium ethylenediaminetetraacetate and 250g of anhydrous potassium sulfate to 550g of acid blue 29. Then, while stirring at 100r / min, add 156g of premix at 2g / min. Then, add 75g of synergist in 5 portions and mix at 300r / min for 25min. Then, disperse at 1000r / min at 45℃ for 35min. Then, heat treat at 55℃ for 95min. Finally, add 8g of magnesium silicate, pulverize, and pass through a 200-mesh sieve to obtain anodized dye.

[0024] Example 3: A method for preparing an anodized dye is as follows: S1: Add 60 mL of 0.5 mol / L magnesium nitrate aqueous solution to 140 mL of 0.5 mol / L zinc nitrate aqueous solution and stir for 30 min. Then add 400 mL of 1 mol / L sodium carbonate aqueous solution and stir for 30 min to obtain a mixed suspension. S2: Add 40g of wollastonite powder (height-to-diameter ratio 11-17:1) to 400mL of deionized water and stir at 60℃ for 40min. Then adjust the pH of the slurry to 10 with 0.1mol / L sodium hydroxide aqueous solution, then heat to 87℃ and add 600mL of mixed suspension dropwise at 2mL / min while stirring at 800r / min. Maintain the pH at 10.5 with 0.05mol / L nitric acid aqueous solution. Then react at 87℃ for 2h. After that, filter and wash the filter cake with hot deionized water at 60℃ until the conductivity of the filtrate is 100μS / cm. Finally, dry at 110℃ for 15h and grind to obtain the precursor powder. S3: Add 8 mL of tetraethyl orthosilicate to 82 mL of anhydrous ethanol and stir for 20 min. Then add 8 mL of deionized water and 2 mL of 28% ammonia water and stir for 7 h to obtain silica sol. S4: Add 40 mL of deionized water and 4 mL of silane coupling agent KH-550 to 260 mL of anhydrous ethanol and stir for 60 min. Then add 80 g of precursor powder and ultrasonically disperse for 40 min. Then heat to 45 °C and add 100 mL of silica sol dropwise at 1 mL / min while stirring at 600 r / min. Then stir at 45 °C for 5 h. Then filter and wash the filter cake 5 times with anhydrous ethanol. Dry at 80 °C for 8 h. Then heat to 550 °C in a muffle furnace at 5 °C / min and keep at that temperature for 3 h. After cooling, grind and pass through a 400 mesh sieve to obtain the synergist. S5: Add 0.6g of ammonium persulfate to 12g of deionized water and stir for 30min to obtain an initiator solution; S6: Add 25g anhydrous ethanol, 12g hydroxyethyl acrylate, 25g methyl methacrylate, 10g silane coupling agent KH-570, 0.5g fatty alcohol polyoxyethylene ether AEO-9, and 1.2g light stabilizer UV-327 to 50g deionized water and stir at 65℃ for 40min. Then add 3.5g initiator solution and stir for 20min. Then raise the temperature to 70℃ at 1℃ / min. Then add 9g initiator solution dropwise at 0.1g / min and stir at 70℃ for 100min. After cooling to 40℃, add 0.1g hydroquinone and stir for 10min. Finally, adjust the pH to 7.5 with 10% sodium hydroxide aqueous solution to obtain the fixing agent solution. S7: Mix 120g of color-fixing agent solution, 30g of fatty alcohol polyoxyethylene ether AEO-9, 37.5g of sodium dihydrogen phosphate, and 12.5g of disodium hydrogen phosphate and stir for 18 minutes. Then adjust the pH to 6 with a 10% sodium hydroxide aqueous solution to obtain the premix. S8: Add 50g of trisodium hydroxyethyl ethylenediamine triacetate and 300g of anhydrous potassium sulfate to 700g of Acid Yellow 99. Then, while stirring at 100r / min, add 200g of premix at 2g / min. Then, add 80g of synergist in 6 portions and mix at 300r / min for 30min. Then, disperse at 1000r / min at 50℃ for 40min. Then, heat treat at 55℃ for 100min. Finally, add 10g of magnesium stearate, pulverize, and pass through a 200-mesh sieve to obtain anodized dye.

[0025] Comparative Example 1: Compared with Example 1, this comparative example only replaces the "fixing agent solution" added in the preparation process of S7 with "deionized water". All other steps and parameters are the same, and will not be repeated in this comparative example. Finally, the anodic oxide dye is obtained.

[0026] Comparative Example 2: Compared with Example 1, this comparative example only replaces "disodium aminotriacetate" added in the preparation process of S8 with "anhydrous sodium sulfate". All other steps and parameters are the same, and will not be repeated in this comparative example. Finally, the anodic oxide dye is obtained.

[0027] Comparative Example 3: Compared with Example 1, this comparative example only did not add a "synergist" in the preparation process of S8. All other steps and parameters were the same, and will not be repeated here. The final result was anodized dye.

[0028] Performance testing: First, the residual oil on the surface of aluminum alloy 5052 was cleaned with the special degreasing agent MC (purchased from Baianmei Innovation Technology (Guangzhou) Co., Ltd.). Then, it was polished with smokeless chemical polishing agent PP-541 (purchased from Baianmei Innovation Technology (Guangzhou) Co., Ltd.). Then, anodizing was performed (using an electrolyte with a sulfuric acid concentration of 168.56 g / L and an aluminum content of 13.59 g / L, applying a DC power supply, controlling the voltage at 13.5V, the electrolyte temperature at 20℃, and the oxidation time at 30 min to form an oxide film with a thickness of 10 μm). After cleaning, it was dyed twice with a 0.5 g / L 30℃ anodizing dye aqueous solution prepared in Examples 1-3 and Comparative Examples 1-3 for 1 min and 4 min respectively. After cleaning, it was sealed with an 8 g / L high-temperature sealing agent PHS-5000 (purchased from Baianmei Innovation Technology (Guangzhou) Co., Ltd.) aqueous solution at 85℃ for 20 min to obtain the test piece.

[0029] Weather resistance testing: Referring to GB / T 2423.24-2022 standard, the specimens prepared by the anodic oxidation dyes of Examples 1-3 and Comparative Examples 1-3 of this invention were tested under UV-A 340nm light source and 68W / m² light. 2 The ΔL (difference in brightness), Δa (difference in red-green), and Δb (difference in yellow-blue) values ​​before and after 72 hours of treatment at a blackboard temperature of 63℃ under a ·nm irradiance were measured, and the total color difference ΔE was calculated. The measurement results are shown in Table 1.

[0030] Determination of anti-mildew properties: Referring to GB / T 1741-2020 standard, the specimens prepared with anodic oxidation dyes in Examples 1-3 and Comparative Examples 1-3 of this invention were wiped with 75% alcohol and air-dried for 15 minutes, then irradiated with ultraviolet germicidal lamps for 30 minutes, and finally sprayed with spores at a concentration of 5×10⁻⁶. 6 A suspension of Aspergillus niger spores per mL (1.0 mL was sprayed per 50 mm × 50 mm specimen) was placed in a mold incubator at 27 °C and 90% relative humidity after standing for 10 min. After 28 days of incubation, the mold coverage level (grade) was determined. The results are shown in Table 1.

[0031] Determination of adhesion stability Referring to GB / T 9286-2021 standard, the adhesion grade (level) of specimens made from the anodic dyes of Examples 1-3 and Comparative Examples 1-3 of this invention was determined after 100 cycles (one cycle consists of treatment at -20℃ for 1 hour, then at 25℃ for 10 minutes, then at 80℃ for 1 hour, and finally at 25℃ for 10 minutes). The results are shown in Table 1.

[0032] Corrosion resistance testing: Referring to GB / T 12967.3-2022 standard, the color difference ΔE of the specimens made from the anodic oxidation dyes of Examples 1-3 and Comparative Examples 1-3 of this invention was determined before and after continuous spraying with a 50 g / L sodium chloride aqueous solution at pH 6.8 at 35°C for 240 h, followed by immersion in a 25 mL / L sulfuric acid aqueous solution at 23°C for 24 h, and then immersion in a 5 g / L sodium hydroxide aqueous solution at 23°C for 10 min. The results are shown in Table 1.

[0033] Table 1: Performance test results of Examples 1-3 and Comparative Examples 1-3 Data Analysis: As can be seen from Table 1, the anodic oxide dyes prepared in the embodiments of the present invention have excellent weather resistance, mildew resistance, adhesion stability, and corrosion resistance.

[0034] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. An anodizing dye, characterized in that, The raw materials include the following parts by weight: 400-700 parts azo dye, 20-50 parts metal complexing agent, 200-300 parts filler, 80-120 parts fixing agent solution, 10-30 parts dispersant, 20-50 parts pH stabilizer, 70-80 parts synergist, and 5-10 parts anti-caking agent; The synergist is prepared by first loading zinc magnesium carbonate and basic carbonate onto wollastonite powder, then treating it with silane coupling agent KH-550, coating it with silica, calcining it at 550°C, cooling it, grinding it, and passing it through a 300-400 mesh sieve. The fixing agent solution is prepared from hydroxyethyl acrylate, methyl methacrylate, silane coupling agent KH-570, fatty alcohol polyoxyethylene ether AEO-9, light stabilizer UV-327, ammonium persulfate, and hydroquinone.

2. The anodized dye according to claim 1, characterized in that, The preparation method of the synergist is as follows: A1: Add magnesium nitrate aqueous solution to zinc nitrate aqueous solution and stir well, then add sodium carbonate aqueous solution and stir for 20-30 min to obtain a mixed suspension; A2: Add wollastonite powder to deionized water and stir at 60℃ for 30-40 min. Then adjust the pH to 9-10, raise the temperature to 83-87℃ and drop in the mixed suspension. Then react at 83-87℃ for 2 h. Finally filter, wash, dry and grind to obtain precursor powder. A3: Add tetraethyl orthosilicate to anhydrous ethanol and stir well. Then add deionized water and ammonia and stir for 6-7 hours to obtain silica sol. A4: Add deionized water and silane coupling agent KH-550 to anhydrous ethanol and stir for 40-60 min. Then add precursor powder and ultrasonically disperse for 30-40 min. After heating to 45℃, add silica sol dropwise and stir for 4-5 h. After filtration, washing, and drying, heat to 550℃ in a muffle furnace at 5℃ / min and hold for 2-3 h. After cooling, grind and pass through a 300-400 mesh sieve to obtain the synergist.

3. The anodizing dye according to claim 2, characterized in that, The volume ratio of the zinc nitrate aqueous solution, magnesium nitrate aqueous solution, and sodium carbonate aqueous solution described in A1 is 140:60:400-410; The concentration of the zinc nitrate aqueous solution described in A1 is 0.5 mol / L; The concentration of the magnesium nitrate aqueous solution described in A1 is 0.5 mol / L; The concentration of the sodium carbonate aqueous solution described in A1 is 1 mol / L; The ratio of deionized water, wollastonite powder, and mixed suspension described in A2 is 400 mL: 40 g: 600-610 mL.

4. The anodizing dye according to claim 2, characterized in that, The volume ratio of anhydrous ethanol, tetraethyl orthosilicate, deionized water, and ammonia in A3 is 82-83:8:8:2; The ammonia solution mentioned in A3 is an ammonia solution with a mass fraction concentration of 28%; The ratio of anhydrous ethanol, deionized water, silane coupling agent KH-550, precursor powder, and silica sol described in A4 is 260mL:40mL:4mL:70-80g:100mL.

5. The anodizing dye according to claim 1, characterized in that, The method for preparing the fixing agent solution is as follows: B1: Add ammonium persulfate to deionized water and stir well to obtain an initiator solution; B2: Add anhydrous ethanol, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent KH-570, fatty alcohol polyoxyethylene ether AEO-9, and light stabilizer UV-327 to deionized water and stir at 65°C for 30-40 min. Then, add the initiator solution for the first time and stir for 15-20 min. Next, raise the temperature to 70°C and add the initiator solution dropwise for the second time, stirring for 90-100 min. After cooling to 35-40°C, add hydroquinone and stir for 5-10 min. Finally, adjust the pH to 7.0-7.5 to obtain the fixing agent solution.

6. The anodizing dye according to claim 5, characterized in that, The mass ratio of deionized water to ammonium persulfate mentioned in B1 is 10-12:0.5-0.6; The mass ratio of deionized water, anhydrous ethanol, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent KH-570, fatty alcohol polyoxyethylene ether AEO-9, light stabilizer UV-327, the first added initiator solution, the second added initiator solution, and hydroquinone in B2 is 40-50:20-25:10-12:20-25:8-10:0.5:0.8-1.2:3-3.5:7-9:0.

1.

7. The anodizing dye according to claim 1, characterized in that, The dispersant is either fatty alcohol polyoxyethylene ether AEO-9 or AEO-10; The pH stabilizer is a mixture of sodium dihydrogen phosphate and disodium hydrogen phosphate in a mass ratio of 3:

1.

8. The anodizing dye according to claim 1, characterized in that, The azo dye is any one of Acid Black ATT-M, Acid Blue 29, and Acid Yellow 99; The metal complexing agent is any one of disodium aminotriacetate, disodium ethylenediaminetetraacetate, and trisodium hydroxyethylethylenediaminetriacetate. The filler is either anhydrous sodium sulfate or anhydrous potassium sulfate; The anti-caking agent is any one of fumed silica, magnesium silicate, and magnesium stearate.

9. The method for preparing anodized dye according to any one of claims 1-8, characterized in that, Includes the following steps: S1: Mix the color-fixing agent solution, dispersant, and pH stabilizer for 15-20 minutes, then adjust the pH to 5-6 with a 10% sodium hydroxide aqueous solution to obtain the premix. S2: Add metal complexing agent and filler to azo dye, then add premix while stirring, then add synergist and mix at 300 r / min for 20-30 min, then disperse at 1000 r / min at 40-50℃ for 30-40 min, then heat treat at 55℃ for 90-100 min, finally add anti-caking agent and crush and pass through a 200 mesh sieve to obtain anodized dye.

10. The application of an anodizing dye as described in any one of claims 1-8 in the fields of aluminum building materials, aluminum home appliances, and aluminum automotive parts.

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