Novel aluminum profile oxidation coloring method

Abstract

The invention relates to the technical field of aluminum material manufacturing, in particular to a novel aluminum profile oxidation coloring method, which is characterized in that water vapor is arranged for hole sealing, the hole sealing speed is higher than that of traditional boiling water hole sealing, and the dependency relationship between hole sealing quality and water quality and between hole sealing quality and value is smaller than that of boiling water hole sealing; after hole sealing, lime which is common in boiling water hole sealing is rarely generated, during hole sealing of the dyed anode oxide film, the danger of dye overflow and color fading is rarely generated, and sealing treatment is performed by a potassium aluminum dichromate chemical oxidation sealing agent at the end of production, so that the hole sealing quality is improved, coloring is uniform, dark spots do not exist, the corrosion resistance is improved, and the service life of the anode oxide film is prolonged. And the method is suitable for a dyed anode oxide film.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum material production, and in particular to a novel method for oxidation coloring of aluminum profiles. Background Art

[0002] The specific strength of aluminum alloy is close to that of high alloy steel, and its specific stiffness exceeds that of steel. It has good casting properties and plastic processing properties, good electrical and thermal conductivity, good corrosion resistance and weldability. It can be used as a structural material and is widely used in aerospace, aviation, transportation, construction, electromechanical, light chemical and daily necessities.

[0003] In the prior art, the surface of aluminum alloy profiles must be treated before use to improve the anti-corrosion performance of the profiles and to have a certain color decorative effect. Aluminum alloy profile products are divided into electrolytic coloring, spraying organic coatings and other products according to the surface treatment method. The technical problem to be solved by this invention is to overcome the defects of the prior art and provide an aluminum profile oxidation electrolytic coloring process that can achieve better coloring in an alkaline environment; and this invention comprehensively optimizes from the oxidation treatment solution to the process parameters to produce a non-fading and corrosion-resistant aluminum profile. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention solves the technical problems by adopting a technical solution: a novel method for oxidation coloring of aluminum profiles, comprising the following steps: Step 1: Degreasing: Soak the aluminum in a circulating 50°C degreasing solution for 5 minutes to remove oil and dust from the surface of the aluminum. Step 2: Chemical cleaning: Soak the aluminum material obtained in step 1 in an acid solution, and then wash it with water to remove aluminum oxide and impurities on the surface of the aluminum material; Step 3: Oxidation treatment: Soak the aluminum material in an oxidizing solution, with a current density of 1.6dm², a working voltage of 16V, an electrolysis temperature of 20°C, and treatment for 60 minutes to obtain an anodic oxide film on the aluminum surface; a uniform oxide film is formed on the aluminum surface; Step 4, water washing: the aluminum material oxidized in step 3 is washed with water twice, the pH of the water washing is 1.1 and 1.0 respectively, the time is 10s and 20s respectively, and the conductivity is 120ms / m; remove the excess oxidizing liquid; Step 5, electrolytic coloring: immerse the aluminum material washed in step 4 into an electrolytic coloring solution containing a metal salt for electrolysis at a temperature of 20° C. for 3 minutes; Step 6, sealing: After the aluminum material colored in step 5 is rinsed with 55℃ water, it is sealed in 100℃ steam for 10-12 minutes; the unsealed anodic oxide film has a high porosity and strong adsorption capacity due to the large area of ​​micropores, which is easy to adsorb pollutants in the environment, affecting the appearance of the film, and is also easily corroded by corrosive anions, causing damage to the film; the Al2O3 on the surface and pore wall of the oxide film undergoes hydration reaction in hot water to generate hydrated aluminum oxide, which increases the volume of the original oxide film by 33% to 100%. The expansion of the oxide film volume significantly reduces the membrane pores, thereby achieving the purpose of sealing.

[0005] Step 7: Cleaning: Place the aluminum material that has been colored in step 4 into clean water and clean it with ultrasonic vibration to remove excess oxidants and colorants; Step 8. Drying: Place the cleaned aluminum into a drying device for drying; ensure that the surface of the aluminum is dry, and that the quality of the color film is stable and the adhesion is good; Step 9: Sealing treatment: Use potassium dichromate sealing agent for sealing treatment, the treatment temperature is 95℃, the treatment time is 25 minutes, then take out the aluminum material, and the oxidation coloring is completed. This is an important measure to make up for the defects of high porosity and high adsorption capacity on the surface anodized film, so as to improve the corrosion resistance, light resistance, wear resistance and insulation of parts.

[0006] The present invention is further configured as follows: the degreasing solution in the step one is an alkaline solution, and the alkaline solution includes sodium carbonate, potassium pyrophosphate, sodium hydroxide, sodium chloride, a complexing agent, an organic base, a thickener, a surfactant, a corrosion inhibitor and water, wherein the weight portion of the sodium carbonate is 12 parts, the weight portion of potassium pyrophosphate is 3 parts, the weight portion of sodium hydroxide is 5 parts, the weight portion of sodium chloride is 1 part, the weight portion of the complexing agent is 4 parts, the weight portion of the organic base is 8 parts, the weight portion of the thickener is 0.1 parts, the weight portion of the surfactant is 1 part, the weight portion of the corrosion inhibitor is 0.1 parts, and the weight portion of water is 70 parts.

[0007] The material of the complexing agent is sodium gluconate, the material of the organic base is triethanolamine, the material of the thickener is sodium carboxymethyl cellulose, the material of the surfactant is nonylphenol polyoxyethylene ether, and the material of the corrosion inhibitor is benzotriazole. Sodium gluconate can be used as a high-efficiency chelating agent, steel surface cleaning agent, glass bottle cleaning agent, and aluminum oxide coloring in the electroplating industry in the metal surface treatment and water treatment industries; triethanolamine can improve the removal of oily dirt, especially non-polar sebum, and at the same time, the decontamination performance can be improved by increasing the alkalinity. And it has excellent compatibility; sodium carboxymethyl cellulose can form a film on the surface of aluminum, so that a low-oxygen, high-carbon dioxide gas environment is formed between the film and the aluminum, thereby reducing the gas exchange rate and the material exchange rate; benzotriazole is used in rust-proof oil (fat) products, and is mostly used as a gas phase corrosion inhibitor circulating water treatment agent for copper and copper alloys.

[0008] The present invention is further configured that the acidic solution in step 2 contains 300 ml / L of hydrochloric acid, 60 ml / L of phosphoric acid, 120 ml / L of hydrogen peroxide, 80 ml / L of stabilizer and 2 ml / L of surfactant, wherein the stabilizer is sulfite, and the surfactant is fatty acid sucrose ester with an HLB value of 12-16, and the aluminum material is immersed for 2 minutes at room temperature. Sulfite slows down the reaction, maintains chemical balance, reduces surface tension, and prevents light, thermal or oxidative decomposition.

[0009] The present invention is further configured such that the oxidizing liquid in step three includes 215 g / L sulfuric acid, 8 g / L sulfosalicylic acid, 2 g / L tartaric acid, 0.8 mL / L spartol, 6 mL / L lactic acid, 5 mL / L glycerol, 4 g / L manganese sulfate, and the rest is distilled water.

[0010] The present invention is further configured such that the drying temperature in step seven is 120° C. and the drying time is 10 minutes.

[0011] The present invention is further configured that the coloring solution in step five contains 18 g / L stannous sulfate, 20 g / L hydrogen sulfide and 1.8 g / L catechol, and the process parameters during coloring are: pH 1.2, temperature 21°C; voltage 20V, time 15min.

[0012] The beneficial effects of the present invention are as follows: The present invention arranges water vapor sealing, and the sealing speed is faster than that of traditional boiling water sealing. The dependence of sealing quality on water quality and sealing quality on value is smaller than that of boiling water sealing. White ash commonly seen in boiling water sealing is less likely to appear after sealing. When sealing the dyed anodized film, there is less risk of dye overflow and fading. At the end of production, the film is sealed with a potassium dichromate aluminum chemical oxidation sealant to improve the sealing quality. The film has uniform coloring without dark spots, and has improved corrosion resistance. The film is more suitable for use with dyed anodized films. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a flow chart of the method of the present invention; Figure 2 It is a performance test table of the present invention. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses. Embodiment 1:

[0015] See also Figure 1 - Figure 2 The present invention provides a technical solution: a novel method for oxidation coloring of aluminum profiles, comprising the following steps: Step 1: Degreasing: Soak the aluminum material in a circulating 50°C degreasing solution for 5 minutes; Step 2: Chemical cleaning: Soak the aluminum material after step 1 in an acid solution, and then wash it with water; Step 3: Oxidation treatment: Soak the aluminum material in an oxidizing solution, with a current density of 1.6 dm², a working voltage of 16 volts, an electrolysis temperature of 20°C, and treatment for 60 minutes to obtain an anodic oxide film on the aluminum surface; Step 4, water washing: the aluminum material oxidized in step 3 is washed with water twice, the pH of the water washing is 1.1 and 1.0 respectively, the time is 10s and 20s respectively, and the conductivity is 120ms / m; Step 5, electrolytic coloring: immerse the aluminum material washed in step 4 into an electrolytic coloring solution containing a metal salt for electrolysis at a temperature of 20° C. for 3 minutes; Step 6: Sealing: Rinse the surface of the aluminum material colored in step 5 with 55°C water, and then seal it in 100°C steam for 10-12 minutes; Step 7: Cleaning: Put the aluminum material that has been colored in step 4 into clean water and clean it with ultrasonic vibration; Step 8: Drying: Place the cleaned aluminum material into a drying device for drying; Step 9: Sealing treatment: Use potassium dichromate aluminum chemical oxidation sealer for sealing treatment at a temperature of 95°C for 25 minutes, then take out the aluminum material and the oxidation coloring is completed.

[0016] The degreasing solution in step one is an alkaline solution, which includes sodium carbonate, potassium pyrophosphate, sodium hydroxide, sodium chloride, a complexing agent, an organic base, a thickener, a surfactant, a corrosion inhibitor and water. The weight parts of sodium carbonate are 12 parts, the weight parts of potassium pyrophosphate are 3 parts, the weight parts of sodium hydroxide are 5 parts, the weight parts of sodium chloride are 1 part, the weight parts of the complexing agent are 4 parts, the weight parts of the organic base are 8 parts, the weight parts of the thickener are 0.1 parts, the weight parts of the surfactant are 1 parts, the weight parts of the corrosion inhibitor are 0.1 parts, and the weight parts of water are 70 parts.

[0017] The material of the complexing agent is sodium gluconate, the material of the organic base is triethanolamine, the material of the thickener is sodium carboxymethyl cellulose, the material of the surfactant is nonylphenol polyoxyethylene ether, and the material of the corrosion inhibitor is benzotriazole.

[0018] In step 2, the acid solution contains 300 ml / L hydrochloric acid, 60 ml / L phosphoric acid, 120 ml / L hydrogen peroxide, 80 ml / L stabilizer and 2 ml / L surfactant, and the aluminum material is immersed in the acid solution at room temperature for 2 minutes.

[0019] In step 3, the oxidizing solution includes 215 g / L sulfuric acid, 8 g / L sulfosalicylic acid, 2 g / L tartaric acid, 0.8 mL / L spartol, 6 mL / L lactic acid, 5 mL / L glycerol, 4 g / L manganese sulfate, and the rest is distilled water.

[0020] In step seven, the drying temperature is 120° C. and the drying time is 10 minutes.

[0021] In step 5, the coloring solution contains 18 g / L of stannous sulfate, 20 g / L of hydrogen sulfide and 1.8 g / L of catechol. The process parameters during coloring are: pH 1.2, temperature 21°C; voltage 20 V, time 15 min. Embodiment 2:

[0022] Based on the first embodiment, a novel method for oxidation coloring of aluminum profiles comprises the following steps: Step 1: Degreasing: Soak the aluminum material in a circulating 50°C degreasing solution for 5 minutes; Step 2: Chemical cleaning: Soak the aluminum material after step 1 in an acid solution, and then wash it with water; Step 3: Oxidation treatment: Soak the aluminum material in an oxidizing solution, with a current density of 1.6 dm², a working voltage of 16 volts, an electrolysis temperature of 20°C, and treatment for 60 minutes to obtain an anodic oxide film on the aluminum surface; Step 4, water washing: the aluminum material oxidized in step 3 is washed with water twice, the pH of the water washing is 1.1 and 1.0 respectively, the time is 10s and 20s respectively, and the conductivity is 120ms / m; Step 5, electrolytic coloring: immerse the aluminum material washed in step 4 into an electrolytic coloring solution containing a metal salt for electrolysis at a temperature of 20° C. for 3 minutes; Step 6: Sealing: Rinse the surface of the aluminum material colored in step 5 with 55°C water, and then seal the surface in 85°C steam for 10-12 minutes; Step 7: Cleaning: Put the aluminum material that has been colored in step 4 into clean water and clean it with ultrasonic vibration; Step 8. Drying: Place the cleaned aluminum material into a drying device for drying, and the oxidation coloring is completed. Embodiment three:

[0023] Based on the first embodiment, a novel method for oxidation coloring of aluminum profiles comprises the following steps: Step 1: Degreasing: Soak the aluminum material in the degreasing solution for 5 minutes; Step 2: Chemical cleaning: Soak the aluminum material after step 1 in an acid solution, and then wash it with water; Step 3: Oxidation treatment: Soak the aluminum material in an oxidizing solution, with a current density of 1.6 dm², a working voltage of 16 volts, an electrolysis temperature of 20°C, and treatment for 60 minutes to obtain an anodic oxide film on the aluminum surface; Step 4, water washing: the aluminum material oxidized in step 3 is washed with water twice, the pH of the water washing is 1.1 and 1.0 respectively, the time is 10s and 20s respectively, and the conductivity is 120ms / m; Step 5, electrolytic coloring: immersing the aluminum material washed in step 4 into an electrolytic coloring solution containing a metal salt for electrolysis; Step 6: Sealing: Rinse the surface of the aluminum material colored in step 5 with 55°C water, and then seal the surface in 90°C steam for 10-12 minutes; Step 7: Cleaning: Put the aluminum material that has been colored in step 4 into clean water and clean it with ultrasonic vibration; Step 8. Drying: Place the cleaned aluminum material into a drying device for drying, and the oxidation coloring is completed.

[0024] Performance Testing Aluminum materials were produced according to the methods of Example 1, Example 2 and Example 3 respectively, and the aluminum materials were tested (as Experimental Group 1, Experimental Group 2 and Experimental Group 3); Through the hydration reaction of alumina, amorphous alumina is converted into hydrated lead oxide called boehmite, i.e. A1203·H20 (A100H). Since the molecular volume of hydrated alumina is 30% larger than that of the original anodized film, the volume expansion makes the micropores of the anodized film filled and closed. Through testing, it is found that the anodized film cannot be converted into a boehmite below a water temperature of 85°C. Although the actual reaction process may be more complicated, it is basically believed that only three parts of Bayer body of crystal water can be generated below a water temperature of 85°C, and the corrosion resistance of Bayer body hydrated alumina is far inferior to that of boehm body hydrated alumina. Therefore, in order to obtain effective sealing, the temperature of actual industrial production operation must be maintained above 95°C, and the sealing time of Experimental Group 1 is less than that of Experimental Groups 2 and 3. In addition, Experimental Group 1 is sealed with potassium aluminum dichromate chemical oxidation sealant at the end of production to improve the sealing quality and corrosion resistance. Therefore, the sealing speed of the present invention is faster than that of traditional boiling water sealing, the dependence of sealing quality on water quality and sealing quality on value is smaller than that of boiling water sealing, white ash commonly seen in boiling water sealing is less likely to appear after sealing, and when sealing dyed anodized films, there is less risk of dye overflow and fading, and the present invention has higher corrosion resistance and is more suitable for use with dyed anodized films.

[0025] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A novel method for oxidation coloring of aluminum profiles, characterized in that: The following steps are involved: Step 1: Degreasing: Soak the aluminum material in a circulating 50°C degreasing solution for 5 minutes; Step 2: Chemical cleaning: Soak the aluminum material after step 1 in an acid solution and then wash it with water; Step 3: Oxidation treatment: Soak the aluminum material in an oxidizing solution, with a current density of 1.6 dm², a working voltage of 16 volts, an electrolysis temperature of 20°C, and treatment for 60 minutes to obtain an anodic oxide film on the aluminum surface; Step 4, water washing: the aluminum material oxidized in step 3 is washed with water twice, the pH of the water washing is 1.1 and 1.0 respectively, the time is 10s and 20s respectively, and the conductivity is 120ms / m; Step 5, electrolytic coloring: immerse the aluminum material washed in step 4 into an electrolytic coloring solution containing a metal salt for electrolysis at a temperature of 20° C. for 3 minutes; Step 6: Sealing: Rinse the surface of the aluminum material colored in step 5 with 55°C water, and then seal it in 100°C steam for 10-12 minutes; Step 7: Cleaning: Put the aluminum material that has been colored in step 4 into clean water and clean it with ultrasonic vibration; Step 8: Drying: Place the cleaned aluminum material into a drying device for drying; Step 9: Sealing treatment: Use potassium dichromate sealing agent for sealing treatment at a temperature of 95°C for 25 minutes, then take out the aluminum material and the oxidation coloring is completed.

2. The novel method for oxidation coloring of aluminum profiles according to claim 1, characterized in that: The degreasing solution in the step 1 is an alkaline solution, which includes sodium carbonate, potassium pyrophosphate, sodium hydroxide, sodium chloride, a complexing agent, an organic base, a thickener, a surfactant, a corrosion inhibitor and water. The weight parts of the sodium carbonate are 12 parts, the weight parts of potassium pyrophosphate are 3 parts, the weight parts of sodium hydroxide are 5 parts, the weight parts of sodium chloride are 1 part, the weight parts of the complexing agent are 4 parts, the weight parts of the organic base are 8 parts, the weight parts of the thickener are 0.1 parts, the weight parts of the surfactant are 1 parts, the weight parts of the corrosion inhibitor are 0.1 parts, and the weight parts of water are 70 parts.

3. The method for oxidation coloring of a novel aluminum profile according to claim 1, characterized in that: The material of the complexing agent is sodium gluconate, the material of the organic base is triethanolamine, the material of the thickener is sodium carboxymethyl cellulose, the material of the surfactant is nonylphenol polyoxyethylene ether, and the material of the corrosion inhibitor is benzotriazole.

4. The novel method for oxidation coloring of aluminum profiles according to claim 1, characterized in that: The acidic solution in step 2 contains 300 ml / L hydrochloric acid, 60 ml / L phosphoric acid, 120 ml / L hydrogen peroxide, 80 ml / L stabilizer and 2 ml / L surfactant, wherein the stabilizer is sulfite and the surfactant is fatty acid sucrose ester with an HLB value of 12-16, and the aluminum material is immersed in the acidic solution for 2 minutes at room temperature.

5. The novel method for oxidation coloring of aluminum profiles according to claim 1, characterized in that: The oxidation solution in step 3 includes 215 g / L sulfuric acid, 8 g / L sulfosalicylic acid, 2 g / L tartaric acid, 0.8 mL / L spartol, 6 mL / L lactic acid, 5 mL / L glycerol, 4 g / L manganese sulfate, and the rest is distilled water.

6. The novel method for oxidation coloring of aluminum profiles according to claim 1, characterized in that: In step seven, the drying temperature is 120° C. and the drying time is 10 minutes.

7. The novel method for oxidation coloring of aluminum profiles according to claim 1, characterized in that: The coloring solution in step 5 contains 18 g / L of stannous sulfate, 20 g / L of hydrogen sulfide and 1.8 g / L of catechol, and the process parameters during coloring are: pH 1.2, temperature 21° C., voltage 20 V, and time 15 min.

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