Aluminum chemical blackening agent for replacing aluminum anodic oxidation process and dyeing process thereof

Abstract

The invention discloses an aluminum chemical blackening agent for replacing an aluminum anodic oxidation process and a dyeing process thereof, and relates to the technical field of chemical blackening agents, the aluminum chemical blackening agent comprises the following raw materials: 50-100 g / L of sodium hydroxide, 20-50 g / L of sodium carbonate, 10-30 g / L of glucose, 30-50 g / L of zinc oxide, 10-25 g / L of molybdenum salt, and 1-5 g / L of a corrosion inhibitor; the dyeing process comprises the following steps of product organic oil removal, aluminum chemical oil removal, aluminum chemical extinction, aluminum chemical black dyeing treatment, aluminum sealing agent treatment and drying. According to the aluminum chemical blackening agent and the dyeing process thereof, a matt black oxide layer with high precision and strong adhesive force can be chemically oxidized on the surface of aluminum and aluminum alloy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical blackening agents, in particular to an aluminum chemical blackening agent and a blackening process thereof for replacing an aluminum anodic oxidation process. BACKGROUND

[0002] At present, the blackening treatment process of industrial aluminum alloy is relatively mature. A general treatment method is an aluminum anodic oxidation process. First, a material is pretreated for 30-300 seconds with a 40-80℃ NaOH solution (concentration of 50-200 g / L) and a 15-25℃ HNO3 solution (concentration of 15-30%) to remove dirt on the surface of the material. After water washing, the material is placed in a 10-20% H2SO4 solution for anodic oxidation treatment, with a current density of 1-2 A / dm2 and a temperature of 20-30℃, and a treatment time of 10-30 minutes. After water washing, chemical dyeing is performed. The material is first immersed in a 90-100℃ CoAc2 solution (concentration of 50-100 g / L) for 10-15 minutes, then immersed in a 90-100℃ Na2S solution (concentration of 50-100 g / L) for 20-30 minutes, or immersed in a 90-100℃ KMnO4 solution (concentration of 15-25 g / L) for 20-30 minutes. Finally, the material is immersed in 90-100℃ distilled water for 20-30 minutes for sealing treatment. 2

[0003] After the above-mentioned traditional blackening process is used to treat aluminum matrix composites reinforced by silicon carbide whiskers, aluminum borate whiskers, etc., the surface of the material mainly presents a gray-green or gray-white tone. It is found through scanning electron microscopy that there is an obvious whisker covering layer on the surface, which is direct evidence of excessive dissolution of the composite material in the corrosion medium. Experimental analysis shows that the introduction of whiskers significantly changes the corrosion resistance of the aluminum matrix composite material. When using NaOH, HNO3, H2SO4 or Na2S, etc. corrosive solution for treatment, if the solution concentration is too high or the immersion time is too long, the composite material is prone to excessive corrosion. This excessive corrosion can cause the formation of a whisker exposed layer on the surface of the matrix, which seriously weakens the bonding strength of the subsequent blackening layer and the substrate. Therefore, the conventional aluminum alloy blackening process is difficult to form a well-adhered blackening coating on the surface of the whisker-reinforced aluminum matrix composite material. SUMMARY

[0004] In order to obtain a blackening layer with good bonding strength to the substrate, the present application provides an aluminum chemical blackening agent and a blackening process thereof for replacing an aluminum anodic oxidation process.

[0005] The aluminum chemical blackening agent provided by the present application for replacing the aluminum anodic oxidation process adopts the following technical solution: ​An aluminum chemical blackening agent for replacing the aluminum anodic oxidation process, raw materials of which include: sodium hydroxide 50-100 g / L, sodium carbonate 20-50 g / L, glucose 10-30 g / L, zinc oxide 30-50 g / L, molybdenum salt 10-25 g / L, corrosion inhibitor 1-5 g / L.

[0006] Preferably, the raw materials of the aluminum chemical blackening agent include: sodium hydroxide 60-70 g / L, sodium carbonate 30-40 g / L, glucose 15-20 g / L, zinc oxide 35-45 g / L, molybdenum salt 15-20 g / L, corrosion inhibitor 2-4 g / L.

[0007] Preferably, the corrosion inhibitor is one of N(alpha)-Boc-L-tryptophan and N(alpha)-Boc-N(1)-formyl-L-tryptophan.

[0008] Preferably, the molybdenum salt is one of sodium molybdate, ammonium molybdate and ammonium tetratungstate.

[0009] The application provides a dyeing process of an aluminum chemical blackening agent for replacing the aluminum anodic oxidation process, which adopts the following technical scheme: The dyeing process of the aluminum chemical blackening agent for replacing the aluminum anodic oxidation process comprises the following steps: S1. Organic degreasing: immerse the product to be subjected to surface blackening treatment in an organic degreasing agent, and organic degreasing is performed at room temperature for 2-5 minutes; then wash with water for several times; S2. Aluminum chemical degreasing: immerse the product after organic degreasing in a chemical degreasing agent, and chemical degreasing is performed at room temperature for 5-15 minutes; then wash with water for several times; S3. Aluminum chemical matting: immerse the product after chemical degreasing in a chemical matting agent, and matting is performed at room temperature for 20-50 seconds; then wash with water for several times; S4. Aluminum chemical blackening: adopt the aluminum chemical blackening agent to perform blackening treatment on the product after chemical matting, and the treatment is performed at room temperature for 2-5 minutes; then wash with water for several times, and dry; S5. Aluminum sealing agent treatment: adopt the aluminum sealing agent to perform sealing treatment on the product after blackening, and the treatment is performed at room temperature for 1-5 minutes; then wash with water for several times; S6. Drying: dry the product after the sealing agent treatment at a temperature of 100-120 ℃ for 30-60 minutes.

[0010] Preferably, the organic degreasing agent is composed of 30-50 g / L sodium hydroxide and 0.5-1 g / L industrial detergent.

[0011] Preferably, the chemical degreasing agent is 50-60 g / L sodium hydroxide.

[0012] Preferably, the chemical darkening agent consists of 120-150 g / L sulfuric acid, 40-50 g / L nitric acid.

[0013] Preferably, the aluminum sealing agent is prepared from the following raw materials by weight: 80-200 parts of isopropyl alcohol, 10-20 parts of polyvinyl butyral, 5-10 parts of gamma-glycidoxypropyltrimethoxysilane, 5-10 parts of acidic silica sol. Preferably, the method for preparing the aluminum sealing agent comprises the following steps: The isopropyl alcohol is stirred at a temperature of 40-50℃ and a rotation speed of 500-600rpm, and the polyvinyl butyral is added dropwise. After stirring for 2-4h until the polyvinyl butyral is completely dissolved, the solution is cooled. Then the gamma-glycidoxypropyltrimethoxysilane is added and stirred uniformly. After stirring for 10-30min at a rotation speed of 300-400rpm, the acidic silica sol is added dropwise. The rotation speed is increased to 500-700rpm, and the solution is stirred for 30-50min to obtain the aluminum sealing agent.

[0014] In summary, the present application includes at least one of the following beneficial technical effects: 1. The aluminum chemical blackening agent and the dyeing process provided by the present application realize a revolutionary replacement of the traditional aluminum anodizing process, completely eliminating complex operation steps such as power-on, warming, and hanging up and down, and can complete efficient treatment at room temperature. The process is particularly optimized for aluminum lenses and precise components such as aluminum metal spacers and gaskets in the lenses. Through the innovative chemical blackening liquid formula and the simplified process flow, the darkening treatment efficiency is significantly improved, not only forming a high-precision dull black oxidation layer, but also ensuring that the film layer and the substrate have excellent bonding strength. Compared with the traditional anodizing process, the present solution has the outstanding advantages of convenient operation, stable process, and controllable cost. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The aluminum chemical blackening agent obtained by the present application is shown in the physical map. DETAILED DESCRIPTION

[0016] The present application is further described in detail below in conjunction with examples.

[0017] The chemical reagents used in the preparation examples, examples, and comparative examples provided by the present application are all commercially available goods, and their trademarks and manufacturers are as follows: Acidic silica sol, Shanghai Maikelin Biochemical Technology Co., Ltd., product number: S790505; Industrial cleaning agent, Dongguan Yongan Technology Co., Ltd., product name: environmentally friendly water-based cleaning agent.

[0018] Preparation Example 1 80 g of isopropyl alcohol was stirred at a temperature of 40°C and a rotation speed of 500 rpm, and 10 g of polyvinyl butyral was added dropwise. After stirring for 2 h until the polyvinyl butyral was completely dissolved, the mixture was cooled. Then 5 g of γ-glycidoxypropyltrimethoxysilane was added and stirred uniformly. After stirring for 10 min at a rotation speed of 300 rpm, 5 g of acidic silica sol was added dropwise. After stirring for 30 min at a rotation speed of 500 rpm, an aluminum sealing agent was obtained.

[0019] Preparation Example 2 140 g of isopropyl alcohol was stirred at a temperature of 45°C and a rotation speed of 550 rpm, and 15 g of polyvinyl butyral was added dropwise. After stirring for 3 h until the polyvinyl butyral was completely dissolved, the mixture was cooled. Then 7.5 g of γ-glycidoxypropyltrimethoxysilane was added and stirred uniformly. After stirring for 20 min at a rotation speed of 350 rpm, 7.5 g of acidic silica sol was added dropwise. After stirring for 40 min at a rotation speed of 600 rpm, an aluminum sealing agent was obtained.

[0020] Preparation Example 3 200 g of isopropyl alcohol was stirred at a temperature of 50°C and a rotation speed of 600 rpm, and 20 g of polyvinyl butyral was added dropwise. After stirring for 4 h until the polyvinyl butyral was completely dissolved, the mixture was cooled. Then 10 g of γ-glycidoxypropyltrimethoxysilane was added and stirred uniformly. After stirring for 30 min at a rotation speed of 400 rpm, 10 g of acidic silica sol was added dropwise. After stirring for 50 min at a rotation speed of 700 rpm, an aluminum sealing agent was obtained.

[0021] Example 1 Taking LY2 hard aluminum alloy as an example, black dyeing treatment was carried out on the surface of the aluminum alloy. The specific dyeing process is as follows: S1. Organic degreasing: the product to be subjected to surface black dyeing treatment was immersed in an organic degreasing agent at room temperature for 2 min; then washed with clean water once; S2. Aluminum chemical degreasing: the product after organic degreasing was immersed in a chemical degreasing agent at room temperature for 5 min; then washed with clean water 4 times; S3. Aluminum chemical matting: the product after chemical degreasing was immersed in a chemical matting agent at room temperature for 20 s; then washed with clean water 4 times; S4. Aluminum chemical black dyeing: the product after chemical matting was subjected to black dyeing treatment using an aluminum chemical black dyeing agent at room temperature for 2 min; then washed with clean water 4 times and dried; S5. Aluminum sealing agent treatment: the product after black dyeing was subjected to sealing treatment using an aluminum sealing agent at room temperature for 1 min; then washed with clean water 4 times; S6. Drying: the product after sealing agent treatment was dried at a temperature of 100°C for 30 min; The organic degreasing agent is composed of 30 g / L sodium hydroxide and 0.5 g / L industrial detergent; The chemical degreasing agent is 50 g / L sodium hydroxide; The chemical matting agent is composed of 120 g / L sulfuric acid and 40 g / L nitric acid; The aluminum sealing agent is prepared by the preparation method of Preparation Example 1; The aluminum chemical blackening agent is composed of 50 g / L sodium hydroxide, 20 g / L sodium carbonate, 10 g / L glucose, 30 g / L zinc oxide, 10 g / L sodium molybdate, and 1 g / L N(α)-Boc-L-tryptophan.

[0022] Example 2 Taking LY2 hard aluminum alloy as an example, the surface of the aluminum alloy is subjected to blackening treatment, and the specific dyeing process is as follows: S1. Organic degreasing: the product to be subjected to surface blackening treatment is immersed in an organic degreasing agent, and the organic degreasing is performed at room temperature for 3.5 minutes; then the product is rinsed with clean water for 2 times; S2. Aluminum chemical degreasing: the product after organic degreasing is immersed in a chemical degreasing agent, and the chemical degreasing is performed at room temperature for 10 minutes; then the product is rinsed with clean water for 5 times; S3. Aluminum chemical matting: the product after chemical degreasing is immersed in a chemical matting agent, and the matting is performed at room temperature for 35 seconds; then the product is rinsed with clean water for 5 times; S4. Aluminum chemical blackening: the product after chemical matting is subjected to blackening treatment by using an aluminum chemical blackening agent, and the treatment is performed at room temperature for 3.5 minutes; then the product is rinsed with clean water for 5 times and dried; S5. Aluminum sealing agent treatment: the product after blackening is subjected to sealing treatment by using an aluminum sealing agent, and the sealing treatment is performed at room temperature for 3 minutes; then the product is rinsed with clean water for 5 times; S6. Drying: the product after sealing agent treatment is dried at a temperature of 110°C for 45 minutes; The organic degreasing agent is composed of 40 g / L sodium hydroxide and 0.75 g / L industrial detergent; The chemical degreasing agent is 55 g / L sodium hydroxide; The chemical matting agent is composed of 135 g / L sulfuric acid and 45 g / L nitric acid; The aluminum sealing agent is prepared by the preparation method of Preparation Example 1; The aluminum chemical blackening agent is composed of 50 g / L sodium hydroxide, 20 g / L sodium carbonate, 10 g / L glucose, 30 g / L zinc oxide, 10 g / L sodium molybdate, and 1 g / L N(α)-Boc-L-tryptophan.

[0023] Example 3 Take LY2 hard aluminum alloy as an example, the surface of the aluminum alloy is dyed black, and the specific dyeing process is as follows: S1. Organic degreasing: the product to be subjected to surface blackening treatment is immersed in an organic degreasing agent, and the organic degreasing is carried out at room temperature for 5 minutes; then it is washed with clean water for 3 times; S2. Aluminum chemical degreasing: the product after organic degreasing is immersed in a chemical degreasing agent, and the chemical degreasing is carried out at room temperature for 15 minutes; then it is washed with clean water for 6 times; S3. Aluminum chemical matting: the product after chemical degreasing is immersed in a chemical matting agent, and the matting is carried out at room temperature for 50 seconds; then it is washed with clean water for 6 times; S4. Aluminum chemical blackening: the product after chemical matting is subjected to blackening treatment by using an aluminum chemical blackening agent, and the treatment is carried out at room temperature for 5 minutes; then it is washed with clean water for 6 times and dried; S5. Aluminum sealing agent treatment: the product after blackening is subjected to sealing treatment by using an aluminum sealing agent, and the sealing treatment is carried out at room temperature for 5 minutes; then it is washed with clean water for 6 times; S6. Drying: the product after sealing agent treatment is dried at a temperature of 120℃ for 60 minutes; The organic degreasing agent is composed of 50g / L sodium hydroxide and 1g / L industrial detergent; The chemical degreasing agent is 60g / L sodium hydroxide; The chemical matting agent is composed of 150g / L sulfuric acid and 50g / L nitric acid; The aluminum sealing agent is prepared by the preparation method of Preparation Example 1; The aluminum chemical blackening agent is composed of the following raw materials: 50g / L sodium hydroxide, 20g / L sodium carbonate, 10g / L glucose, 30g / L zinc oxide, 10g / L sodium molybdate, and 1g / L N(α)-Boc-L-tryptophan.

[0024] Example 4 Example 4 differs from Example 1 in that the aluminum chemical blackening agent used in Example 4 is composed of the following raw materials: 60g / L sodium hydroxide, 30g / L sodium carbonate, 15g / L glucose, 35g / L zinc oxide, 15g / L sodium molybdate, and 2g / L N(α)-Boc-L-tryptophan.

[0025] Example 5 Example 5 differs from Example 1 in that the aluminum chemical blackening agent used in Example 5 is composed of the following raw materials: 65g / L sodium hydroxide, 35g / L sodium carbonate, 17.5g / L glucose, 40g / L zinc oxide, 17.5g / L sodium molybdate, and 3g / L N(α)-Boc-L-tryptophan.

[0026] Example 6 Example 6 differs from Example 1 in that the aluminum chemical blacking agent employed in Example 6 consists of the following raw materials: sodium hydroxide 70 g / L, sodium carbonate 40 g / L, glucose 20 g / L, zinc oxide 45 g / L, sodium molybdate 20 g / L, N(a)-Boc-L-tryptophan 4 g / L.

[0027] Example 7 Example 7 differs from Example 1 in that the aluminum chemical blacking agent employed in Example 7 consists of the following raw materials: sodium hydroxide 100 g / L, sodium carbonate 50 g / L, glucose 30 g / L, zinc oxide 50 g / L, sodium molybdate 25 g / L, N(a)-Boc-L-tryptophan 5 g / L.

[0028] Example 8 Example 8 differs from Example 1 in that the corrosion inhibitor employed in the aluminum chemical blacking agent employed in Example 8 is N a-Boc-N1-formyl-L-tryptophan.

[0029] Example 9 Example 9 differs from Example 1 in that the molybdenum salt employed in Example 9 is ammonium molybdate.

[0030] Example 10 Example 10 differs from Example 1 in that the molybdenum salt employed in Example 10 is tetramolybdate ammonium.

[0031] Example 11 Example 11 differs from Example 1 in that the aluminum blocking agent employed in Example 11 is prepared by the preparation method of Preparation Example 2.

[0032] Example 12 Example 12 differs from Example 1 in that the aluminum blocking agent employed in Example 12 is prepared by the preparation method of Preparation Example 3.

[0033] Example 13 Example 13 differs from Example 1 in that the aluminum blocking agent employed in Example 13 is an epoxy resin.

[0034] Comparative Example 1 Comparative Example 1 differs from Example 1 in that no corrosion inhibitor is added to the aluminum chemical blacking agent employed in Comparative Example 1.

[0035] Comparative Example 1 Comparative Example 1 differs from Example 1 in that the aluminum chemical blacking agent employed in Comparative Example 1 Comparative Example 2 Comparative Example 2 differs from Example 1 in that the aluminum chemical blackening agent employed in Comparative Example 2 consists of the following raw materials: sodium hydroxide 40 g / L, sodium carbonate 10 g / L, glucose 5 g / L, zinc oxide 25 g / L, sodium molybdate 5 g / L, N(a)-Boc-L-tryptophan 0.5 g / L.

[0036] Comparative Example 3 Comparative Example 3 differs from Example 1 in that the aluminum chemical blackening agent employed in Comparative Example 3 consists of the following raw materials: sodium hydroxide 110 g / L, sodium carbonate 60 g / L, glucose 40 g / L, zinc oxide 55 g / L, sodium molybdate 30 g / L, N(a)-Boc-L-tryptophan 6 g / L.

[0037] Performance detection test The aluminum alloy surfaces treated by Examples 1-13 and Comparative Examples 1-3 were detected: I. Neutral salt spray: a 5wt% NaCl solution was used to form a salt spray environment to accelerate the corrosion resistance of the surface coating of the test material.

[0038] The specific test procedure was to adjust the salt spray deposition amount to about 1.5 mL / (80 cm 2 ·h) in a salt spray chamber with a volume of 400 L and a temperature of 35±2℃, and continuously spray for 48 hours, with the sample placed at an angle of 15°-30° to the vertical direction to avoid direct salt spray impact, and the nozzle perpendicular to the sample at a distance of 20-30 cm; after 72 hours of testing, the sample surface was rinsed with clean water, dried, and observed; if the surface black color did not fall off or the area of the fallen-off part was ≤5%, it was recorded as qualified, otherwise it was unqualified; the results are shown in Table 1.

[0039] II. Adhesion grade test: after being placed for more than six hours after the reaction, a hundred grids were drawn according to the ISO2409 standard, with the same direction grid lines parallel to each other and the different direction grid lines perpendicular to each other to form a grid pattern; 3M adhesive tape was used to flatten and press the grid area, and the tape was smoothly torn off at an angle of about 60° within 0.5-1 seconds; each test piece needed to be tested at least at three different positions; the results are shown in Table 1.

[0040] III. Color difference: the color difference was tested by a high-precision spectrophotometer, and the specific steps were as follows: after the instrument was calibrated using a standard white board and a black board, four points were uniformly selected for testing outside the center area of the sample to obtain L*(lightness), a*(red-green axis), and b*(yellow-blue axis) values. The calculation used the ΔEab formula in the CIELAB color space, and the specific method was as follows: the test values of the four selected points were subtracted from the average L*(lightness), a*(red-green axis), and b*(yellow-blue axis) values of the center area to obtain ΔL*, Δa*, and Δb*, which were then substituted into the formula ΔEab=√[(ΔL)2 +(Delta a) 2 +(Delta b) 2 The average of the four values is obtained, and the results are shown in Table 1.

[0041] The specific test results are as follows: Table 1 Performance test results Neutral salt spray test Adhesion rating Color difference ΔΕ Example 1 Pass 0 0.75 Example 2 Pass 0 0.72 Example 3 Pass 0 0.78 Example 4 Pass 0 0.71 Example 5 Pass 0 0.63 Example 6 Pass 0 0.69 Example 7 Pass 0 0.80 Example 8 Pass 0 0.81 Example 9 Pass 0 0.98 Example 10 Pass 0 0.92 Example 11 Pass 0 0.68 Example 12 Pass 0 0.74 Example 13 Fail 1 1.32 Comparative Example 1 Fail 1 1.25 Comparative Example 2 Fail 0 1.09 Comparative Example 3 Fail 0 1.14 As can be seen from the test results in Table 1, the aluminum chemical blackening agent and the dyeing process provided by the present application for replacing the aluminum anodic oxidation process can obtain a high-precision and strong-adhesion dull black oxide layer, and has good adhesion, corrosion resistance and wear resistance, and can meet the demand of improving the pixel of photographic equipment such as camera, microscope, monitoring, vehicle-mounted and medical.

[0042] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution according to the needs after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An aluminum chemical blackening agent for replacing an aluminum anodizing process, characterized by: The raw materials include: sodium hydroxide 50-100 g / L, sodium carbonate 20-50 g / L, glucose 10-30 g / L, zinc oxide 30-50 g / L, molybdenum salt 10-25 g / L, corrosion inhibitor 1-5 g / L.

2. An aluminum chemical blackening agent for replacing an aluminum anodizing process according to claim 1, characterized by: The raw materials include: sodium hydroxide 60-70 g / L, sodium carbonate 30-40 g / L, glucose 15-20 g / L, zinc oxide 35-45 g / L, molybdenum salt 15-20 g / L, corrosion inhibitor 2-4 g / L.

3. The aluminum chemical blackening agent for replacing an aluminum anodizing process according to claim 1, characterized by: The corrosion inhibitor is one of N(alpha)-Boc-L-tryptophan and N(alpha)-Boc-N(1)-formyl-L-tryptophan.

4. The aluminum chemical blackening agent for replacing an aluminum anodizing process according to claim 1, characterized by: The molybdenum salt is one of sodium molybdate, ammonium molybdate and ammonium tetratungstate.

5. The dyeing process for aluminum chemical blackening agent instead of aluminum anodizing process according to claims 1-4, characterized in that: The method comprises the following steps: S1. Organic oil removal: immerse the product to be subjected to surface blackening treatment in an organic oil removal agent, and carry out organic oil removal at normal temperature for 2-5 minutes; then wash with water for several times; S2. Aluminum chemical oil removal: immerse the product after organic oil removal in a chemical oil removal agent, and carry out chemical oil removal at normal temperature for 5-15 minutes; then wash with water for several times; S3. Aluminum chemical dulling: immerse the product after chemical oil removal in a chemical dulling agent, and carry out dulling at normal temperature for 20-50 seconds; then wash with water for several times; S4. Aluminum chemical blackening: carry out blackening treatment on the product after chemical dulling by using an aluminum chemical blackening agent, and carry out treatment at normal temperature for 2-5 minutes; then wash with water for several times and dry; S5. Aluminum sealing agent treatment: carry out sealing treatment on the product after blackening by using an aluminum sealing agent, and carry out sealing treatment at normal temperature for 1-5 minutes; then wash with water for several times; S6. Drying: dry the product after sealing agent treatment at a temperature of 100-120 ℃ for 30-60 minutes.

6. The dyeing process for aluminum chemical blackening agent in place of aluminum anodizing process as claimed in claim 5, wherein: The organic oil removal agent is composed of 30-50 g / L sodium hydroxide and 0.5-1 g / L industrial detergent.

7. The dyeing process for aluminum chemical blackening agent in place of aluminum anodizing process as claimed in claim 5 wherein: The chemical oil removal agent is 50-60 g / L sodium hydroxide.

8. The dyeing process for aluminum chemical blackening agent in place of aluminum anodizing process as claimed in claim 5 wherein: The chemical dulling agent is composed of 120-150 g / L sulfuric acid and 40-50 g / L nitric acid.

9. The dyeing process for aluminum chemical blackening agent in place of aluminum anodizing process as claimed in claim 5 wherein: The aluminum sealing agent is prepared from the following raw materials in parts by weight: 80-200 parts of isopropyl alcohol, 10-20 parts of polyvinyl butyral, 5-10 parts of γ-glycidoxypropyltrimethoxysilane and 5-10 parts of acid silicon sol.

10. The dyeing process for aluminum chemical blackening agent in place of aluminum anodizing process as claimed in claim 9, wherein: The preparation method of the aluminum sealing agent comprises the following steps: Add polyvinyl butyral drop by drop in isopropyl alcohol at a temperature of 40-50 ℃ and a rotation speed of 500-600 rpm, stir for 2-4 h until the polyvinyl butyral is completely dissolved, and then cool; then add γ-glycidoxypropyltrimethoxysilane, stir uniformly, stir at a rotation speed of 300-400 rpm for 10-30 min, then add acid silicon sol drop by drop, increase the rotation speed to 500-700 rpm, and stir for 30-50 min to obtain the aluminum sealing agent.

Images