Water-based shielding protective coating for chemical corrosion of aluminum alloy and preparation method of water-based shielding protective coating

Abstract

The invention discloses a water-based shielding protective coating for aluminum alloy chemical corrosion, the water-based shielding protective coating is prepared from water-based strippable resin, water-based polyurethane resin, water-based slurry, a thickener, a flatting agent, water and an amine neutralizer, and the water-based slurry is prepared from water-based acrylic resin, a release agent, a filler, a wetting dispersant, a defoaming agent and water. Water-based acrylic resin, water-based polyurethane resin and water-based strippable resin are compounded to serve as base resin, water is used for replacing an organic solvent, functional filler and auxiliaries are introduced, and the water-based shielding protective coating good in water resistance and chemical corrosion liquid resistance is prepared and suitable for temporary protection in the aluminum alloy chemical corrosion machining process.

Description

Technical Field

[0001] The invention belongs to the technical field of fine chemical coating materials and applications, and particularly relates to a water-based shielding protective coating for chemical corrosion of aluminum alloys and a preparation method thereof. Background Art

[0002] Aluminum alloy chemical corrosion shielding coatings are primarily used as a temporary protective coating during the chemical corrosion process. They provide temporary protection during the process and are removed after the chemical corrosion process is complete. Shielding coatings are primarily used in chemical corrosion processing of aluminum alloys; for temporary protection of metal substrates, organic glass, and painted surfaces; and for temporary protection of instrument surfaces and mechanical equipment from scratches and abrasions.

[0003] Existing aluminum alloy chemical corrosion shielding protective coatings all use non-environmentally friendly organic solvents such as toluene, xylene, and tetrachloroethylene as diluents. The coatings themselves contain very high VOCs, which can cause serious damage to human health during the preparation and use of the coatings. At the same time, high VOC emissions cause serious damage to the environment. Summary of the Invention

[0004] This invention addresses the high VOC content of existing solvent-based shielding protective coatings by developing a water-based shielding protective coating resistant to chemical corrosion solutions. Using a water-based acrylic resin, a water-based polyurethane resin, and a water-based strippable resin as the base resin, water is used instead of organic solvents, and functional fillers and additives are introduced to produce a water-based shielding protective coating with excellent water and chemical corrosion resistance. The coating is suitable for temporary protection of aluminum alloys during chemical corrosion processing.

[0005] In order to achieve the above object, the present invention provides a water-based shielding protective coating for aluminum alloy chemical corrosion, which is composed of the following components by mass ratio:

[0006]

[0007]

[0008] The aqueous slurry is composed of the following components by mass ratio:

[0009]

[0010] The water-based acrylic resin is at least one of Carfil-9131, SGRW-3335, and FX-9172, all of which are highly acid-resistant and alkali-resistant water-based acrylic resins.

[0011] The waterborne polyurethane resin is at least one of RHERI U105, WPU1025, and Crysol-6136.

[0012] The water-based strippable resin is at least one of PVR5606 and JL-5188B, both of which are highly acid-resistant and alkali-resistant water-based strippable resins.

[0013] The release agent is at least one of zinc stearate and calcium stearate.

[0014] The filler is at least one or two different types of fillers selected from the group consisting of talc, sericite, kaolin, and magnesium silicate.

[0015] The defoaming agent is one or more of BYK-021, HF3019, HF-3052, and BYK-093.

[0016] The wetting and dispersing agent is one or more of HS6064, HP2466, and BYK-190.

[0017] The amine neutralizing agent is 0.1% sodium hydroxide solution.

[0018] The thickener is one or more of SN-T9722, BYK-425, and RHEOBYK-7600.

[0019] The leveling agent is one or more of SN-4333, HS-6064E, and SN-4341.

[0020] A second aspect of the present invention provides a method for preparing the above-mentioned aqueous shielding protective coating for aluminum alloy chemical corrosion, comprising the following steps:

[0021] 1) Preparation of aqueous slurry: Add aqueous acrylic resin, wetting dispersant, and water into a mixing tank, stir evenly with a high-speed stirrer at a stirring speed of 600-700 r / min, add a release agent and filler while stirring, increase the stirring speed to 700-850 r / min to mix the materials evenly, grind and disperse them in a sand mill after mixing evenly, grind them in a sand mill to a fineness of ≤40 μm, add a defoaming agent, reduce the stirring speed to 600-700 r / min, continue stirring for 30-60 minutes, and filter the material to obtain an aqueous slurry.

[0022] 2) Preparation of water-based shielding protective coating for chemical corrosion of aluminum alloy: put water, water-based strippable resin, and water-based polyurethane resin into a mixing tank, stir them evenly under high-speed stirring at a stirring speed of 600-700 r / min, add amine neutralizer while stirring to adjust the pH to 7-8, then add water-based slurry and leveling agent, increase the stirring speed to 700-850 r / min, stir for 2 hours, then add thickener, continue stirring for 1 hour, adjust the non-volatile matter content to more than 30%, and filter the material.

[0023] Beneficial effects

[0024] The present invention prepares a water-based shielding protective coating by compounding a water-based acrylic resin, a water-based polyurethane resin and a water-based strippable resin as a base resin, using water as a solvent, and introducing functional fillers and additives. The coating film has excellent water resistance, resistance to chemical corrosion liquids and a certain elasticity, has suitable peel strength on aluminum alloys, is suitable for temporary protection during the chemical corrosion processing of aluminum alloys, and its performance can meet the application requirements of chemical milling processes. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Example 1:

[0027] Weigh 32 g of water-based acrylic resin Carfil-9131, 32 g of water and 1.5 g of wetting and dispersing agent HS6064, start stirring (600 r / min) and mix evenly. Add 8 g of zinc stearate, 15 g of talc and 5 g of magnesium silicate under stirring condition (600 r / min), increase the stirring rate to 800 r / min to mix the materials evenly, and grind and disperse them on a sand mill after mixing until the fineness is 35 μm. After that, add 0.5 g of defoamer BYK-093 and stir (600 r / min) for 30 minutes to prepare water-based slurry A.

[0028] Preparation of water-based shielding protective coating for chemical corrosion of aluminum alloy:

[0029] Weigh 22g of water-based strippable resin PVR5606, 28g of water-based polyurethane resin WPU1025, and 12g of water, start stirring (600r / min) and mix evenly, add 0.15g of 0.1% sodium hydroxide solution under stirring condition (600r / min), continue stirring and test the pH value to 7, then add 37g of water-based slurry A, 0.8g of leveling agent SN-4333, increase the stirring rate to 800r / min, stir for 2 hours, then add 0.4g of thickener SN-T9722, stir (800r / min) for 1 hour, use water to adjust the non-volatile matter content to greater than 30%, filter the material to obtain a water-based shielding protective coating for chemical corrosion of aluminum alloy.

[0030] The spray coating is applied on aluminum alloy that has been pre-treated. After the coating is completely cured, the test performance is as follows:

[0031]

[0032] Example 2

[0033] Weigh 35 g of water-based acrylic resin FX-9172, 35 g of water and 1.8 g of wetting and dispersing agent HP2466, start stirring (700 r / min) and mix evenly, add 6 g of calcium stearate, 10 g of talc and 12 g of sericite under stirring condition (700 r / min), increase the stirring rate to 850 r / min, mix the materials evenly, and grind and disperse them in a sand mill after mixing until the fineness is 30 microns, then add 0.3 g of defoaming agent BYK-021 and stir (600 r / min) for 30 minutes to prepare water-based slurry B.

[0034] Preparation of water-based shielding protective coating for chemical corrosion of aluminum alloy:

[0035] Weigh 20g of water-based strippable resin JL-5188B, 26g of water-based polyurethane resin RHERI U105, and 12g of water, start stirring (600r / min) and mix evenly, add 0.15g of 0.1% sodium hydroxide solution under stirring condition (700r / min), continue stirring and test the pH value to 8, then add 33g of water-based slurry B and 0.9g of leveling agent HS-6064E, increase the stirring rate to 850r / min, stir for 2 hours, then add 0.3g of thickener BYK-425, stir (850r / min) for 1 hour, use water to adjust the non-volatile matter content to greater than 30%, filter the material to obtain a water-based shielding protective coating for chemical corrosion of aluminum alloy.

[0036] The spray coating is applied on aluminum alloy that has been pre-treated. After the coating is completely cured, the test performance is as follows:

[0037]

[0038] Example 3

[0039] Weigh 20 g of water-based acrylic resin FX-9172 and 14 g of water-based acrylic resin SGRW-3335, 33 g of water and 1.6 g of wetting and dispersing agent BYK-190, start stirring (650 r / min) and mix evenly, add 5 g of calcium stearate and 1 g of zinc stearate, 13 g of talc and 12 g of kaolin under stirring condition (650 r / min), increase the stirring rate to 700 r / min, mix the materials evenly, and grind and disperse them in a sand mill after mixing to a fineness of 30 microns, then add 0.6 g of defoamer HF-3019 and stir (650 r / min) for 1 hour to prepare water-based slurry C.

[0040] Preparation of water-based shielding protective coating for chemical corrosion of aluminum alloy:

[0041] Weigh 10g of water-based strippable resin JL-5188BH and 11g of water-based strippable resin PVR5606, 18g of water-based polyurethane resin WPU1025, 8g of water-based polyurethane resin Crysol-6136, and 12g of water, start stirring (650r / min) and mix evenly, add 0.15g of 0.1% sodium hydroxide solution under stirring condition (650r / min), continue stirring and test the pH value to 7, then add 38g of water-based slurry C and 0.7g of leveling agent SN-4341, increase the stirring rate to 750r / min, stir for 2 hours, then add 0.3g of thickener RHEOBYK-7600, stir (750r / min) for 1 hour, use water to adjust the non-volatile matter content to greater than 30%, filter the material to obtain a water-based shielding protective coating for chemical corrosion of aluminum alloy.

[0042] The spray coating is applied on aluminum alloy that has been pre-treated. After the coating is completely cured, the test performance is as follows:

[0043]

[0044]

[0045] The present disclosure has been described using the aforementioned embodiments. However, the aforementioned embodiments are merely exemplary embodiments of the present disclosure. It should be noted that the disclosed embodiments do not limit the scope of the present disclosure. On the contrary, modifications and alterations made without departing from the spirit and scope of the present disclosure are within the scope of patent protection of the present disclosure.

Claims

1. A water-based shielding protective coating for aluminum alloy chemical corrosion, characterized by: By mass ratio, it is composed of the following components: The aqueous slurry is composed of the following components by mass ratio: The aqueous slurry is prepared by the following method: adding an aqueous acrylic resin, a wetting dispersant, and water into a mixing tank, stirring them uniformly with a high-speed stirrer at a stirring speed of 600 to 700 r / min, adding a release agent and a filler while stirring, increasing the stirring speed to 700 to 850 r / min to mix the materials uniformly, grinding and dispersing them in a sand mill after mixing them uniformly, grinding them in the sand mill to a fineness of ≤40 μm, adding a defoaming agent, reducing the stirring speed to 600 to 700 r / min, and continuing stirring for 30 to 60 minutes, filtering the material to obtain an aqueous slurry.

2. The aqueous shielding protective coating for aluminum alloy chemical corrosion according to claim 1, characterized in that: The water-based acrylic resin is one or more of Carfil-9131, SGRW-3335, and FX-9172.

3. The aqueous shielding protective coating for aluminum alloy chemical corrosion according to claim 1, characterized in that: The waterborne polyurethane resin is one or more of RHERI U105, WPU1025, and Crysol-6136.

4. The aqueous shielding protective coating for aluminum alloy chemical corrosion according to claim 1, characterized in that: The water-based strippable resin is one or more of PVR5606 and JL-5188B.

5. The aqueous shielding protective coating for aluminum alloy chemical corrosion according to claim 1, characterized in that: The release agent is one or more of zinc stearate and calcium stearate.

6. The aqueous shielding protective coating for aluminum alloy chemical corrosion according to claim 1, characterized in that: The filler is one or more of talc, sericite, kaolin and magnesium silicate.

7. The aqueous shielding protective coating for aluminum alloy chemical corrosion according to claim 1, characterized in that: The defoamer is one or more of BYK-021, HF3019, HF-3052, and BYK-093; the wetting and dispersing agent is one or more of HS6064, HP2466, and BYK-190; the thickener is one or more of SN-T9722, BYK-425, and RHEOBYK-7600; and the leveling agent is one or more of SN-4333, HS-6064E, and SN-4341.

8. The aqueous shielding protective coating for aluminum alloy chemical corrosion according to claim 1, characterized in that: The amine neutralizing agent is 0.1% sodium hydroxide solution.

9. A method for preparing the aqueous shielding protective coating for aluminum alloy chemical corrosion according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: adding water, water-based strippable resin and water-based polyurethane resin into a mixing tank, stirring them uniformly with a high-speed stirring speed of 600-700 r / min, adding an amine neutralizer to adjust the pH to 7-8 during stirring, adding water-based slurry and a leveling agent, increasing the stirring speed to 700-850 r / min, stirring for 2 hours, adding a thickener, continuing stirring for 1 hour, adjusting the non-volatile matter content to be greater than 30%, and filtering the material.

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