Water-based film treating fluid as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of metal surface treatment, and particularly relates to a water-based film layer treating fluid as well as a preparation method and application thereof. The water-based film layer treating fluid is prepared from the following raw materials in percentage by weight: 1 to 10 percent of purine substances and 0.1 to 5 percent of etching agent; the pH value of the water-based film layer treating fluid is acidic. The water-based film layer treating fluid is simple in component, the surface of a base material is activated through the action of an etching agent and a substrate, more copper ions are released to assist in film forming, and metal ions do not need to be additionally added. The conversion film prepared according to the invention is tightly combined with a copper substrate, has no obvious rust after being placed in the air for a long time, and obviously enhances the adhesive force and corrosion resistance of the film layer and the substrate, so that the conversion film has good practical application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal surface treatment, and in particular relates to a water-based film layer treatment liquid and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Chromate passivation films are one of the most effective methods for inhibiting metal corrosion. When applied to metal surfaces, they exhibit exceptional corrosion resistance. The main components of chromate passivation films are Cr(VI), Cr(III), and water. However, their application is limited by the high toxicity and carcinogenicity of Cr(VI) compounds. Therefore, researchers are committed to developing chromium-free, environmentally friendly alternatives.

[0004] The main alternative technologies currently include: (1) Phosphate treatment: a protective film is formed on the metal surface through phosphate, but there are problems such as slow film formation speed, loose film layer, and insufficient corrosion resistance, and phosphorus-containing wastewater can easily lead to eutrophication of water bodies. (2) Silane treatment: a hydrophobic film is formed using silane coupling agents, but a high-temperature curing process is required, which consumes a lot of energy and has strict requirements on substrate pretreatment. (3) Rare earth metal salt treatment: although it is environmentally friendly, rare earth resources are scarce, the cost is high, and it is difficult to apply on a large scale. (4) Organic acid passivation: such as phytic acid, tannic acid, etc., the long-term stability of the film layer is poor. Therefore, there is an urgent need to develop a new type of metal surface treatment liquid with simple composition, green and environmental protection, no need for exogenous metal ions, and excellent film-forming performance. Summary of the Invention

[0005] To address the shortcomings of the aforementioned prior art, the present invention aims to provide a water-based membrane treatment solution, its preparation method, and its application. Specifically, the present invention provides a water-based membrane treatment solution that can be applied to the surface of a copper substrate. This solution is simple in composition, environmentally friendly, requires no added metal ions, and exhibits strong adhesion between the membrane and the metal substrate, effectively enhancing the corrosion resistance of the copper material. This present invention was developed based on the aforementioned research findings.

[0006] In order to achieve the above technical objectives, the technical solutions provided by the present invention are as follows:

[0007] The first aspect of the present invention provides a water-based membrane treatment liquid, which is composed of the following raw materials in percentage by mass: 1-10% purine substance, 0.1-5% etchant, and acidic pH.

[0008] The second aspect of the present invention provides a method for preparing the above-mentioned water-based membrane layer treatment liquid, which comprises: dissolving a purine substance in water, adding an etchant after it is completely dissolved, stirring evenly, and adjusting the pH to acidic.

[0009] The third aspect of the present invention provides the use of the above-mentioned water-based film layer treatment liquid in metal rust prevention and passivation. Furthermore, the metal is copper.

[0010] A fourth aspect of the present invention provides a method for applying the water-based membrane treatment fluid, the method comprising:

[0011] The pre-treated copper substrate is placed in a water-based film treatment solution for static treatment to form a film. The beneficial technical effects of one or more of the above technical solutions are:

[0012] (1) The water-based membrane treatment solution in the above technical solution only needs to add purine substances, etchants and other substances. The composition is simple and no external metal ions are required, which reduces the influence of other impurity ions on the film forming effect and performance.

[0013] (2) The purine-based film-forming substances in the above technical solution are green and environmentally friendly, replacing the highly toxic and highly polluting components in the traditional chromate passivation film, and are environmentally friendly conversion films.

[0014] (3) The preparation method in the above technical solution is simple and has low application cost, so it has good practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 1 is the electrochemical impedance spectroscopy diagram of Examples 1-4 of the present invention and a blank sample.

[0017] Figure 2 This is a scanning electron microscope (SEM) image of Example 3 of the present invention. DETAILED DESCRIPTION

[0018] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0019] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0020] In a typical embodiment of the present invention, a water-based membrane treatment liquid is provided, which is composed of the following raw materials in the following mass percentages: 1-10% purine substances, 0.1-5% etchant; the pH of the water-based membrane treatment liquid is acidic.

[0021] Wherein, the purine substance is at least one of guanine, adenine, xanthine and hypoxanthine; preferably adenine or xanthine.

[0022] The etchant is at least one of hydrogen peroxide, sodium hypochlorite, and ammonium persulfate, preferably sodium hypochlorite.

[0023] In another specific embodiment of the present invention, the pH value of the water-based membrane treatment liquid is 3-5, and further, the pH value is 4.

[0024] The film forming mechanism of the present invention is as follows:

[0025] The present invention is based on the principle that purines serve as the primary film-forming substances. These substances are adsorbed on the copper surface via heteroatoms, allowing the etchant to activate the copper substrate, etching out metal ions and driving the longitudinal growth of the film. The adsorption and etching processes are coordinated, allowing the etched metal ions to complex with more film-forming substances, resulting in a thicker and denser film on the substrate surface. The addition of the etchant eliminates the need for externally added metal ions; film formation is achieved simply by complexing the purines with the metal ions etched by the etchant during the film-forming process.

[0026] In another specific embodiment of the present invention, a method for preparing the above-mentioned water-based membrane layer treatment liquid is provided, which comprises: dissolving a purine substance in water, adding an etchant after it is completely dissolved, stirring evenly, and adjusting the pH to acidic.

[0027] In the present invention, the pH value may be adjusted to acidic using an inorganic acid solution, which may be a nitric acid solution. Furthermore, the concentration of the nitric acid solution is 3-9 mol / L, more preferably 7 mol / L.

[0028] In another embodiment of the present invention, there is provided a use of the above-mentioned water-based film treatment liquid in metal rust prevention and passivation. Furthermore, the metal is copper.

[0029] In another embodiment of the present invention, a method for applying the above-mentioned water-based membrane treatment liquid is provided, the method comprising:

[0030] The pre-treated copper substrate is placed in a water-based film treatment solution for static treatment to form a film.

[0031] In another specific embodiment of the present invention, the pretreatment method includes: polishing and pickling the copper substrate, then washing the surface with water and drying it with cold air.

[0032] In another specific embodiment of the present invention, the standing treatment time is 20-40 minutes, preferably 30 minutes.

[0033] In another specific embodiment of the present invention, the copper substrate after film formation is taken out, and the excess water-based film treatment liquid on the surface of the copper substrate is washed with water, and then dried; further, the drying can be carried out by blowing with cold air.

[0034] It should be noted that, in order to prevent the introduction of exogenous impurities, in the present invention, the water is preferably pure water.

[0035] The present invention will be further described below with reference to the examples. The present invention will be further described below by way of examples, but the present invention is not limited to the scope of the examples described. Based on the examples in the present invention, any variation of the present invention by those skilled in the art without making any creative idea falls within the scope of the present invention. At the same time, in the examples of the present invention, unless otherwise specified, all raw materials for preparation are commercially available products well known to those skilled in the art. In each embodiment of the present invention, the copper plate pretreatment method is to polish and pickle the copper plate, then wash the surface with pure water and dry it with cold air.

[0036] Example 1

[0037] A water-based membrane treatment liquid, the raw material composition weight ratio is as follows: 6% adenine, 0.54% sodium hypochlorite, and the balance is pure water;

[0038] 1. Add adenine to pure water and stir to dissolve;

[0039] 2. Continue to add sodium hypochlorite and stir to dissolve;

[0040] 3. Add 7 mol / L nitric acid aqueous solution to adjust the pH to 4;

[0041] 4. Place the pretreated copper plate into the prepared solution and let it stand at room temperature for 30 minutes;

[0042] 5. Take out the copper plate after film formation, wash the surface with water, and blow dry with cold air to obtain the copper plate after film formation. Then conduct electrochemical testing.

[0043] Example 2

[0044] A water-based membrane treatment liquid has the following raw material composition ratio by mass: 6% adenine, 0.70% sodium hypochlorite, and the balance pure water.

[0045] 1. Add adenine to pure water and stir to dissolve;

[0046] 2. Continue to add sodium hypochlorite and stir to dissolve;

[0047] 3. Add 7 mol / L nitric acid aqueous solution to adjust the pH to 4;

[0048] 4. Place the pretreated copper plate into the prepared solution and let it stand at room temperature for 30 minutes;

[0049] 5. Take out the copper plate after film formation, wash the surface with water, and blow dry with cold air to obtain the copper plate after film formation. Then conduct electrochemical testing.

[0050] Example 3

[0051] A water-based membrane treatment liquid has the following raw material composition ratio by mass: 6% adenine, 0.86% sodium hypochlorite, and the balance pure water.

[0052] 1. Add adenine to pure water and stir to dissolve;

[0053] 2. Continue to add sodium hypochlorite and stir to dissolve;

[0054] 3. Add 7 mol / L nitric acid aqueous solution to adjust the pH to 4;

[0055] 4. Place the pretreated copper plate into the prepared solution and let it stand at room temperature for 30 minutes;

[0056] 5. Take out the copper plate after film formation, wash the surface with water, and blow dry with cold air to obtain the copper plate after film formation. Then conduct electrochemical testing.

[0057] Example 4

[0058] A water-based membrane treatment liquid has the following raw material composition ratio by mass: 6% adenine, 1.10% sodium hypochlorite, and the balance pure water.

[0059] 1. Add adenine to pure water and stir to dissolve;

[0060] 2. Continue to add sodium hypochlorite and stir to dissolve;

[0061] 3. Add 7 mol / L nitric acid aqueous solution to adjust the pH to 4;

[0062] 4. Place the pretreated copper plate into the prepared solution and let it stand at room temperature for 30 minutes;

[0063] 5. Take out the copper plate after film formation, wash the surface with water, and blow dry with cold air to obtain the copper plate after film formation. Then conduct electrochemical testing.

[0064] Test method: electrochemical test

[0065] Impedance spectroscopy was performed using a CHI760 electrochemical workstation, with the sample as the working electrode, the Ag / AgCl electrode as the reference electrode, and the platinum electrode as the auxiliary electrode. The test was performed at room temperature using a 3.5 wt% NaCl solution as the corrosion medium.

[0066] Variation pattern: The electrochemical impedance spectra of the membranes prepared with different concentrations of sodium hypochlorite (0.54%, 0.70%, 0.86%, 1.10%) are as follows: Figure 1 As shown. Under the same adenine concentration, as the etchant concentration increases, the size of the impedance arc changes, and the radius of the arc first increases and then decreases, indicating that the corrosion resistance first increases and then decreases. When the sodium hypochlorite concentration is 0.86%, the film layer exhibits the best corrosion resistance. This shows that with the addition of the etchant, the copper substrate is activated to a higher degree, producing more copper ions that can coordinate with adenine, and the film layer is denser. Among them, the scanning electron microscope image of the film layer prepared at a sodium hypochlorite concentration of 0.86% is shown in FIG. Figure 2 As shown, the thickness of the film layer is at the nanometer level. Through observation, it can be found that there are no pores inside the film layer, and the lower part of the film layer is tightly bonded to the upper part of the metal substrate.

[0067] It should be noted that the above examples are only intended to illustrate the technical solutions of the present invention and are not intended to limit the same. Although the present invention has been described in detail with reference to the examples given, those skilled in the art may modify or replace the technical solutions of the present invention as needed without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A water-based membrane treatment liquid, characterized in that: The method comprises the following raw materials in the following mass percentages: 1-10% purine substances, 0.1-5% etchant; the pH of the water-based film layer treatment liquid is acidic; Wherein, the purine substance is at least one of guanine, adenine, xanthine and hypoxanthine; The etchant is at least one of hydrogen peroxide, sodium hypochlorite, and ammonium persulfate.

2. The water-based membrane treatment liquid according to claim 1, characterized in that: The purine substance is adenine or xanthine; The etchant is sodium hypochlorite.

3. The water-based membrane treatment liquid according to claim 1, characterized in that The pH value of the water-based membrane treatment liquid is 4.

4. The method for preparing a water-based membrane treatment liquid according to any one of claims 1 to 3, characterized in that: The preparation method comprises: dissolving a purine substance in water, adding an etchant after the substance is completely dissolved, stirring the purine substance evenly, and adjusting the pH to acidic.

5. The preparation method according to claim 4, wherein The pH is adjusted to acidic using an inorganic acid solution, which is a 7 mol / L nitric acid solution.

6. Use of the water-based membrane treatment liquid according to any one of claims 1 to 3 in metal rust prevention and passivation.

7. The use according to claim 6, characterized in that The metal is copper.

8. The method for applying the water-based membrane treatment liquid according to any one of claims 1 to 3, characterized in that: The application method comprises: The pre-treated copper substrate is placed in a water-based film treatment solution for static treatment to form a film.

9. The application method according to claim 7, characterized in that: The pretreatment method comprises: polishing and pickling the copper substrate, then washing the surface with water and drying it with cold air.

10. The application method according to claim 7, characterized in that: The standing treatment time is 20-40 minutes.

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