Silane vitrification agent as well as preparation method and application thereof

Abstract

The invention discloses a silane vitrification agent as well as a preparation method and application thereof, and belongs to the technical field of metal surface treatment processes. According to the invention, the wear resistance and adhesive force of the silane vitrification agent are enhanced by adopting the film-forming agents of hexafluorozirconic acid and potassium hexafluorozirconate, the silica sol and the modified epoxy resin together, so that the silane vitrification agent with high wear resistance, corrosion resistance and adhesive force is obtained. The obtained silane vitrification agent is suitable for surface treatment of iron parts, galvanized plates or aluminum materials, and has good market application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of metal surface treatment technology, and particularly relates to a silane ceramic agent and a preparation method and application thereof. Background Art

[0002] Silane ceramics are a new, environmentally friendly metal surface treatment technology that forms a dense, glassy ceramic layer on metal surfaces. This layer not only protects the metal from oxidation and corrosion but also significantly improves its surface hardness and wear resistance. The core advantage of this treatment technology lies in its environmental friendliness. It contains no phosphorus or heavy metals, simplifies wastewater treatment, reduces wastewater treatment costs, and mitigates environmental pollution. Silane ceramics also reduce the surface tension of workpieces, making it easier to form a film on the surface, thereby improving the workpiece's brightness and transparency.

[0003] Traditional phosphating processes require monitoring of multiple parameters, including total acidity, free acidity, and accelerators. These processes are complex, generate significant amounts of sediment, and can easily clog spray pipes. Maintenance costs are high, and equipment life is impacted. These processes contain phosphorus and heavy metals such as zinc, nickel, and manganese, requiring specialized treatment before discharge, placing significant environmental pressure. The spray coating industry faces the pressure and challenges of transformation and upgrading, and the need for newer, more environmentally friendly materials and processes that are energy-intensive, polluting, and inefficient. Against this backdrop, silane ceramics, a phosphorus-free metal surface treatment technology, are gradually replacing traditional phosphating processes due to their environmental friendliness and high efficiency. This technology not only reduces environmental pollution but also improves production efficiency and product quality, and is now widely used in metal surface treatment processes.

[0004] The prior art discloses a nano-ceramic-silane composite film conversion agent containing graphene oxide, but the cost of using graphene oxide is relatively high, and the corrosion resistance needs to be improved.

[0005] Therefore, the development of a silane ceramic agent with high wear resistance, corrosion resistance and high adhesion and its preparation method and application have important research significance and application value. Summary of the Invention

[0006] To address the technical problem of prior art silane ceramics struggling to achieve high wear resistance, corrosion resistance, and adhesion, the present invention primarily aims to provide a silane ceramic. The present invention utilizes film-forming agents, fluorozirconic acid and potassium fluorozirconate, silica sol, and a modified epoxy resin to enhance the wear resistance and adhesion of the silane ceramic, resulting in a silane ceramic with high wear resistance, corrosion resistance, and adhesion.

[0007] Another object of the present invention is to provide a method for preparing the above-mentioned silane ceramic agent.

[0008] Another object of the present invention is to provide the use of the above-mentioned silane ceramic agent in the preparation of iron parts, galvanized sheets or aluminum surface treatment.

[0009] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0010] The present invention protects a silane ceramic agent, which comprises the following components in parts by weight: 4.5-10 parts of a film-forming agent, 0.5-2 parts of a complexing agent, 1-3 parts of nitric acid, 0.5-2 parts of an oxidizing agent, 3-5 parts of a silane coupling agent, 0.5-2 parts of a silica sol, 0.5-2 parts of an epoxy-modified organic silicone resin, and the balance being water;

[0011] Wherein, the film-forming agent is fluozirconic acid and potassium fluozirconate;

[0012] The silica sol is nano silicon dioxide with a particle size of 10 to 30 nm.

[0013] The present invention provides a silane ceramic agent using fluorozirconic acid and potassium fluorozirconate as film-forming agents. Through reaction, a corrosion-resistant zirconium oxide film is formed on the surface of a metal workpiece, achieving passivation of the metal workpiece surface. This film has excellent corrosion resistance, can prevent the metal workpiece from rusting in a short period of time, and strengthens the adhesion between the coating and the substrate. The silane coupling agent improves the strength, hardness, and wear resistance of the ceramic film, enhancing interfacial bonding. The silica sol enhances the wear and corrosion resistance of the ceramic film. The silica sol is nano-silicon dioxide with a particle size of 10 to 30 nm. The specific surface area of the silica sol is inversely proportional to its particle size. The larger the specific surface area of the silica sol, the stronger its water absorption, adsorption, and reactivity. Selecting a particle size range while taking into account cost can ensure the optimal wear and corrosion resistance of the ceramic film. The epoxy-modified silicone resin promotes film formation during the ceramic process, enhances the coating's adhesion and anti-fouling capabilities, and prolongs the salt spray life of both the bare film and the coated film.

[0014] Preferably, the complexing agent is one of ethylenediaminetetraacetic acid or disodium ethylenediaminetetraacetic acid.

[0015] Preferably, the oxidant is one or more of sodium nitrate, zirconium nitrate or ammonium nitrate.

[0016] Preferably, the silane coupling agent is one or more of aminosilane, epoxysilane or acryloxy functional silane.

[0017] More preferably, the silane coupling agent is one or more of KH550, KH560, KH570 or KH792.

[0018] Preferably, the epoxy-modified silicone resin is formed by polycondensation of epoxy resin and silicone.

[0019] The present invention also provides a method for preparing a silane ceramic agent, comprising the following steps:

[0020] The film-forming agent, complexing agent, nitric acid and oxidant are added into water and stirred evenly, and then the silane coupling agent, silica sol and modified epoxy resin are added in sequence and stirred evenly to obtain the silane ceramic agent.

[0021] Preferably, the stirring step comprises the following steps: (1) adding the complexing agent into water to dissolve the complexing agent, and stirring the complexing agent until the complexing agent is completely dissolved.

[0022] (2) Add film-forming agent and oxidant, and stir until the film-forming agent and oxidant are completely dissolved.

[0023] (3) Slowly add nitric acid to adjust the pH to 3-5;

[0024] (4) Add silane coupling agent, silica sol and epoxy modified silicone resin in sequence and stir evenly.

[0025] Preferably, the stirring time is 1 to 15 minutes.

[0026] Preferably, the stirring temperature is 20-30°C.

[0027] The application of the above-mentioned silane ceramic agent in the preparation of iron parts, galvanized sheets or aluminum surface treatment is also within the scope of protection of the present invention.

[0028] Preferably, the silane ceramic agent is used in the preparation of ceramic iron parts.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The silane ceramic provided by the present invention utilizes fluorozirconic acid and potassium fluorozirconate as film-forming agents, a silane coupling agent, silica sol, and an epoxy-modified silicone resin to produce a silane ceramic with high wear resistance, corrosion resistance, and high adhesion. The ceramic ceramic is easy to operate, exhibits strong adhesion between the ceramic layer and the device layer, and between the ceramic layer and the coating layer, and exhibits strong corrosion resistance. The ceramic ceramic is low in cost, has a shortened system length, is easy to control, and offers stable quality. It adheres to industrial environmental protection principles and is suitable for all steel ceramic processes, as well as surface treatments for galvanized steel sheets and aluminum materials. The silane ceramic ceramic is simple to manufacture, easy to use, and safe to transport. It also contains no phosphorus or heavy metals such as zinc, nickel, and manganese. DETAILED DESCRIPTION

[0031] The present invention is further described below with reference to the examples. These examples are intended to illustrate the present invention only and are not intended to limit the scope of the present invention. Experimental methods in the following examples where specific conditions are not specified are generally performed in accordance with conventional conditions in the art or the conditions recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are all commercially available from conventional markets. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention fall within the scope of protection claimed in the present invention.

[0032] Some of the reagents selected in the embodiments and comparative examples of the present invention are described as follows:

[0033] Silica sol 1#: particle size 10nm;

[0034] Silica sol 2#: particle size 20nm;

[0035] Silica sol 3#: particle size 30nm;

[0036] Epoxy modified silicone resin 1#: GM5210, Shanghai Wenjing Chemical;

[0037] Epoxy modified silicone resin 2#: GM5208, Shanghai Wenjing Chemical;

[0038] Silane coupling agent 1#: KH550;

[0039] Silane coupling agent 2#: KH560;

[0040] Complexing agent: EDTA;

[0041] Oxidant: sodium nitrate;

[0042] The silane ceramics of the embodiments and comparative examples of the present invention were prepared by the following process:

[0043] The film-forming agent, complexing agent, nitric acid and oxidant are added into water and stirred evenly, and then the silane coupling agent, silica sol and modified epoxy resin are added in sequence and stirred evenly to obtain the silane ceramic agent.

[0044] The performance test methods and standards of the silane ceramic agents of the embodiments and comparative examples of the present invention are as follows:

[0045] (1) Adhesion test after spraying: After the workpiece is dried by silane ceramic treatment, polyurethane plastic powder or epoxy plastic powder is sprayed by electrostatic adsorption, and the finished product is baked at 180℃. The finished product is tested for adhesion according to the standard of GB / T31586.2-2015, and a 1mm square is scratched on the surface of the workpiece with a grid knife. 2100 small grids are scratched, and the scratching depth must penetrate the surface coating to the sample substrate. Then use a pressure-sensitive tape with a width of 5mm and an adhesion of (10±1)N / 25mm to firmly stick to the small grid to be tested. Rub the tape vigorously with an eraser. Grab one end of the tape and pull it off at a vertical 90-degree angle. Perform the same test twice at the same location. After the test, observe the surface coating of the grid and rate it according to the standard.

[0046] (2) Impact test after spraying: After the workpiece is dried by silane ceramic treatment, polyurethane plastic powder or epoxy plastic powder is sprayed by electrostatic adsorption, and the finished product is baked at a high temperature of 180°C. The finished product is subjected to impact testing in accordance with the standard of GB / T1732-2020. A 1000±1g hammer is used to drop freely from a certain height for impact, and the height (cm) at which cracks and peeling begin to appear is recorded;

[0047] (3) Normal rust prevention time (days): After the workpiece is dried by silane ceramic treatment, polyurethane plastic powder or epoxy plastic powder is sprayed by electrostatic adsorption and baked at 180°C to obtain the finished product. The finished product is placed outdoors and the time when red rust, powder loss, peeling, blistering and other undesirable phenomena begin to appear is recorded;

[0048] (4) Bare film neutral salt spray test (min): The neutral salt spray test is carried out in accordance with GB / T 10125-2021. A sodium chloride solution with a mass ratio of 5% is prepared, and the pH is adjusted to 6.8±0.2 with hydrochloric acid or sodium hydroxide solution. The temperature of the salt solution is heated to maintain 35°C. The sample to be tested is placed in a salt spray tester and sprayed continuously until undesirable phenomena such as red rust appear on the surface of the sample to be tested. The duration of the sample is statistically calculated.

[0049] (5) Neutral salt spray test after spraying (h): After the workpiece is dried by silane ceramic treatment, polyurethane plastic powder or epoxy plastic powder is sprayed by electrostatic adsorption, and the finished product is obtained after high-temperature baking at 180°C. The finished product is subjected to a neutral salt spray test in accordance with GB / T10125-2021 standard. A sodium chloride solution with a mass ratio of 5% is prepared, and the pH is adjusted to 6.8±0.2 using hydrochloric acid or sodium hydroxide solution. The salt solution is heated to maintain the temperature of 35°C. The finished product is placed in a salt spray tester for continuous uninterrupted spray testing. The duration of the sample is calculated statistically when red rust, powdering, peeling, blistering, and other undesirable phenomena appear on the surface of the finished product.

[0050] Examples 1 to 11

[0051] This embodiment provides a series of silane ceramic agents, and the weight percentages of the components in the formulations are shown in Table 1.

[0052] Table 1: Formulas of Examples 1 to 11 (parts)

[0053]

[0054] Comparative Examples 1 to 5

[0055] This comparative example provides a series of silane ceramic agents, the components of which are shown in Table 2.

[0056] Table 2: Formulas of Comparative Examples 1 to 5 (parts)

[0057]

[0058]

[0059] The performance test results of the silane ceramics in the embodiments and comparative examples according to the above-mentioned method are shown in Table 3.

[0060] Table 3 Performance test results of various embodiments and comparative examples

[0061]

[0062] As can be seen from Table 3, the silane ceramics prepared in Examples 1 to 11 of the present invention all have high wear resistance, corrosion resistance, and high adhesion, among which Example 1 is the best component selection.

[0063] In Comparative Example 1, no silica sol was added, and the adhesion test decreased, the impact test was low, and the anti-rust performance decreased to a certain extent; in Comparative Example 2, the epoxy-modified silicone resin was replaced with silicone resin, which had no epoxy group effect, and the adhesion and anti-rust performance of the metal workpiece decreased significantly; in Comparative Example 3, the epoxy-modified silicone resin was replaced with epoxy resin, which had no silane effect, and the compatibility of the epoxy group with the ceramic film components was poor, and the anti-wear and corrosion capabilities decreased significantly; in Comparative Examples 4 and 5, the added amounts of each component were not within the range, and the comprehensive capabilities were significantly decreased.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A silane ceramic agent, characterized in that: The invention comprises the following components in parts by weight: 4.5-10 parts of a film-forming agent, 0.5-2 parts of a complexing agent, 1-3 parts of nitric acid, 0.5-2 parts of an oxidizing agent, 3-5 parts of a silane coupling agent, 0.5-2 parts of a silica sol, 0.5-2 parts of an epoxy-modified organic silicone resin, and the balance being water; Wherein, the film-forming agent is fluozirconic acid and potassium fluozirconate; The silica sol is nano-silicon dioxide with a particle size of 10 to 30 nm.

2. The silane ceramic agent according to claim 1, characterized in that: The complexing agent is one of ethylenediaminetetraacetic acid or disodium ethylenediaminetetraacetic acid.

3. The silane ceramic agent according to claim 1, characterized in that: The oxidant is one or more of sodium nitrate, zirconium nitrate or ammonium nitrate.

4. The silane ceramic agent according to claim 1, characterized in that: The silane coupling agent is one or more of aminosilane, epoxysilane or acryloxy functional silane.

5. The silane ceramic agent according to claim 1, characterized in that: The compounding ratio of the fluorozirconic acid and potassium fluorozirconate is 1-3:1-3.

6. The silane ceramic agent according to claim 1, characterized in that: The epoxy-modified organic silicon resin is formed by polycondensation of epoxy resin and organic silicon.

7. The silane ceramic agent according to claim 1, characterized in that: The silane coupling agent is one or more of KH550, KH560, KH570 or KH792.

8. The method for preparing the silane ceramic agent according to any one of claims 1 to 7, characterized in that: The following steps are involved: The film-forming agent, complexing agent, nitric acid and oxidant are added into water and stirred evenly, and then the silane coupling agent, silica sol and modified epoxy resin are added in sequence and stirred evenly to obtain the silane ceramic agent.

9. Use of the silane ceramic agent according to any one of claims 1 to 7 in the preparation of iron parts, galvanized sheets or aluminum surface treatment.

10. The use according to claim 9, further comprising use of the silane ceramic agent in the preparation of ceramic iron pieces.

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