Steel rust-free coating maintenance material and preparation method thereof

Abstract

The invention relates to a steel rust-free coating maintenance material and a preparation method thereof, and belongs to the technical field of steel corrosion prevention, and the steel rust-free coating maintenance material is prepared by selecting inorganic modified water-based resin as a main raw material, adding a plurality of antirust materials, auxiliary materials and water, and mixing and stirring. The water-based paint is prepared from the following components in parts by weight: 30 to 50 parts of inorganic modified water-based resin, 1.0 to 6.0 parts of rust transforming agent, 1.0 to 5.0 parts of carbon nanotube, 5.0 to 10 parts of aluminum triphosphate, 5.0 to 15 parts of filler, 0.2 to 0.6 part of rheological additive, 0.2 to 0.5 part of defoaming agent, 1.0 to 2.0 parts of coalescing agent and 20 to 30 parts of water. According to the product, rust conversion can be efficiently achieved, the converted material can be used as filler, a firm protective coating is formed on the surface of a steel structure, and the purpose of long-acting corrosion prevention is achieved by combining the rust conversion pigment and the passivator in the protective coating; the heavy anti-corrosion requirement of renovation and maintenance in the fields of bridges, electric power iron towers, large steel structure buildings and the like is met, the purpose of saving manpower and materials is achieved, and the protection effect and safety are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of steel anti-corrosion, and specifically to a rust-free coating maintenance material for steel and a preparation method thereof. Background Art

[0002] Ordinary carbon steel materials have the disadvantage of being easily corroded. Materials such as stainless steel and weathering steel cannot be widely used due to their high prices. Therefore, anti-corrosion measures for carbon steel have always been the focus of research. Common methods for carbon steel anti-corrosion include hot-dip galvanizing anti-corrosion, anti-corrosion coating protection, metal thermal spraying, electroplating, powder spraying, etc. Generally speaking, for the initial anti-corrosion of steel structures, surface treatment is generally carried out by means such as pickling, sandblasting, and shot peening, and then anti-corrosion construction is carried out by different methods to achieve the purpose of extending the service life of metals.

[0003] However, any protection method has a service life. Generally, hot-dip galvanizing and metal thermal spraying are about 20 years, anti-corrosion coatings are about 15 years, electroplating, powder spraying, etc. are about 5 years. For these steel structures that have been installed and are still in service, they need to be treated in time after rust appears. Otherwise, with the further development of corrosion, it will lead to the failure of the steel structure and cause accidents.

[0004] Currently, for the maintenance of steel structures in service, most are through manual grinding. By using means such as wire brushes and angle grinders, the rust products are ground off. After reaching St3 level, the anti-corrosion material is painted again. This method has low efficiency, high labor costs, and the dust and noise generated by grinding cause great damage to construction workers and the environment, and there are many dead corners that cannot be ground, causing certain hidden dangers; another method is to use on-site sandblasting, which also has problems such as high noise, a lot of dust, and high costs. In response to this situation, some rust-inhibiting coating materials have also appeared on the market, mainly focusing on the selection and combination of rust converters. Although rust conversion can achieve rust-inhibiting coating, although the rust on the substrate can be converted into passivating substances after coating, due to its poor ability to prevent rust from occurring again, it can only be used in places with lower anti-corrosion requirements, such as temporary protective coatings for accessory steel structures such as color steel tiles and guardrails. The protection period for one coating is within 5 years, which cannot meet the expected requirements for most steel structures. For some iron towers, bridges, and large steel structure sites, an anti-corrosion layer still needs to be painted on them. However, due to the existence of the rust conversion coating, the subsequent anti-corrosion coating cannot meet the requirements of contacting the steel structure, and the cathodic protection effect is greatly affected, resulting in limited application in this anti-corrosion field. Summary of the Invention

[0005] The purpose of the present invention is to provide a rust-free coating maintenance material for steel and a preparation method thereof to solve the problems raised in the above background art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An iron-free rust removal and painting maintenance material, characterized in that it comprises: selecting an inorganic modified water-based resin as the main raw material, adding a variety of rust prevention materials, auxiliary materials and water, and mixing and stirring to prepare, and its component weight ratio is:

[0008] Selecting an inorganic modified water-based resin as the main raw material, adding a variety of rust prevention materials, auxiliary materials and water, and mixing and stirring to prepare, and its component weight ratio is:

[0009] 30-50 parts of inorganic modified water-based resin, 1.0-6.0 parts of rust converter, 1.0-5.0 parts of carbon nanotube fraction, 5.0-10 parts of aluminum tripolyphosphate, 5.0-15 parts of filler rheology aid, 0.2-0.6 parts, 0.2-0.5 parts of defoamer, 1.0-2.0 parts of film-forming aid, 20-30 parts of water.

[0010] Preferably, the inorganic modified water-based polymer resin is nano-silicon modified epoxy resin, nano-silicon modified acrylic resin, nano-silicon modified vinyl chloride resin, nano-silicon modified styrene-acrylic emulsion or nano-silicon modified vinyl acetate-acrylic emulsion.

[0011] Preferably, the rust converter is iron phosphate, iron chromate, tannic acid phosphate system, mangrove tannin series, potassium ferrocyanide series, phytic acid series, chelated phosphate series, etc.

[0012] Preferably, the carbon nanotube dispersion slurry included is an aqueous dispersion slurry of carbon nanotubes, the carbon nanotube content is ≥5%, and the volume resistivity is ≤20Ω.

[0013] Preferably, the filler included is nano-silica, nano-titanium dioxide, phosphorus iron powder, etc., to improve the hardness, wear resistance and adhesion of the rust conversion coating.

[0014] Preferably, a method for preparing an iron-free rust-removing coating maintenance material is characterized by comprising: putting 20-30 parts of water and 0.2-0.5 part of an antifoaming agent into a paint mixing tank, stirring evenly, then slowly adding 5-10 parts of aluminum tripolyphosphate and 5-15 parts of a filler, dispersing at a high speed of 2000-2500 rpm for 20-30 min, reducing the rotation speed to 1000-1500 rpm, then adding 2-6 parts of a rust converter and 1.0-10.0 parts of a carbon nanotube dispersion slurry, continuously stirring for 20-30 min, reducing the rotation speed to 800-1000 rpm, then adding 30-50 parts of an inorganic modified waterborne resin and continuously stirring for 10-15 min, then adding 1-2 parts of a film-forming auxiliary agent and 0.2-0.6 part of a rheology auxiliary agent, reducing the rotation speed to 500-600 rpm, adding 1-6 parts of a rust converter, continuously stirring for 10-20 min, filtering and packaging to obtain a graphene-modified rust-converting anticorrosive coating.

[0015] Compared with the prior art, the beneficial effect of the present invention in terms of the method is:

[0016] The inorganic modified polymer resin used in this coating can effectively penetrate into the interior of the rust layer due to the grafting of inorganic nano-functional groups on its side chains, divide and coat the rust products, and the composite rust converter can effectively convert the rust in the coating, convert or chelate and coordinate it, make it passivated and not continue to expand, and as a filler, it interacts with the inorganic modified polymer, can add a shielding coating on the steel substrate, prevent the penetration of external corrosive media into the surface of the steel substrate, and extend the anticorrosive life of the coating. The addition of carbon nanotubes endows it with good electrical conductivity, can connect the steel substrate and the zinc-rich coating on it in heavy anticorrosive applications, exhibit good electrochemical protection characteristics, and play a cathodic protection role. Therefore, it can be used alone or in combination with an epoxy zinc-rich coating as an enhanced anticorrosion measure, greatly reducing the rust removal project during the maintenance of bridges, electric towers, petrochemical industries, and large steel structure buildings, saving a large amount of materials and labor, with low cost and good environmental protection. Specific embodiments

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0018] Example 1:

[0019] Put 20 parts of water and 0.3 parts of defoamer into a paint mixing tank, stir evenly, then slowly add 5 parts of aluminum tripolyphosphate, 1 part of nano-silica, and 8 parts of ferrophosphorus powder. After high-speed dispersion at 2000 rpm for 25 min, reduce the rotation speed to 1200 rpm, then add 1 part of iron phosphate rust converter and 1 part of carbon nanotube slurry, continue stirring for 20 min, then reduce the rotation speed to 1000 rpm, then add 50 parts of inorganic modified styrene-acrylic emulsion and continue stirring for 15 min, then add 2 parts of film-forming aid and 0.5 part of rheological aid, reduce the rotation speed to 600 rpm, continue stirring for 20 min, and then perform filtration and packaging to obtain the inorganic modified rust conversion anti-corrosion coating.

[0020] Example 2:

[0021] Put 30 parts of water and 0.2 parts of defoamer into a paint mixing tank, stir evenly, then slowly add 10 parts of aluminum tripolyphosphate, 2 parts of nano-titanium dioxide, and 5 parts of ferrophosphorus powder. After high-speed dispersion at 2500 rpm for 30 min, reduce the rotation speed to 1500 rpm, then add 6 parts of iron chromate phosphate and chelating phosphoric acid rust converter and 10 parts of graphene slurry, continue stirring for 20 min, then reduce the rotation speed to 1000 rpm, then add 45 parts of inorganic modified waterborne epoxy resin and continue stirring for 15 min, then add 0.4 part of rheological aid, reduce the rotation speed to 600 rpm, continue stirring for 10 min, perform filtration and packaging, and use it in combination with the corresponding epoxy curing agent to obtain the inorganic modified rust conversion anti-corrosion coating.

[0022] Example 3:

[0023] Put 25 parts of water and 0.5 parts of defoamer into a paint mixing tank, stir evenly, then slowly add 8 parts of aluminum tripolyphosphate, 1 part of nano-silica, 1 part of nano-titanium dioxide and 12 parts of ferrophosphorus powder filler. After high-speed dispersion at 2500 rpm for 30 min, reduce the rotation speed to 1500 rpm, then add 3 parts of phytic acid-based and iron chromate rust converter and 5 parts of graphene slurry, continue stirring for 30 min, then reduce the rotation speed to 1000 rpm, then add 40 parts of vinyl acetate-acrylate emulsion and continue stirring for 15 min, then add 1.5 parts of film-forming aid and 0.4 part of rheological aid, reduce the rotation speed to 600 rpm, continue stirring for 20 min, and then perform filtration and packaging to obtain the inorganic modified rust conversion anti-corrosion coating.

[0024] Example 4:

[0025] Put 30 parts of water and 0.2 parts of defoamer into a paint mixing tank, stir evenly, and then slowly add 10 parts of aluminum tripolyphosphate, 2 parts of nano-titanium dioxide, and 5 parts of ferrophosphorus powder. After high-speed dispersion at 2500 rpm for 30 min, reduce the rotation speed to 1500 rpm, then add 6 parts of chromate and chelating phosphoric acid rust converter, continue stirring for 20 min, then reduce the rotation speed to 1000 rpm, then add 50 parts of inorganic modified waterborne epoxy resin and continue stirring for 15 min, then add 0.4 parts of rheological aid, reduce the rotation speed to 600 rpm, continue stirring for 10 min, filter and package, and use with the corresponding epoxy curing agent to obtain the inorganic modified rust conversion anti-corrosion coating.

[0026] Performance Test

[0027] After making samples of the inorganic modified rust conversion anti-corrosion coatings obtained in Examples 1 to 4 alone and making composite samples with epoxy zinc-rich coatings (the epoxy zinc-rich coating is applied 24 h after the inorganic modified rust conversion coating is applied, and the metal zinc content in the non-volatile component of the epoxy zinc-rich coating is 80%), then test the adhesion, water resistance, impact resistance, neutral salt spray resistance of the coating film and the compatibility, water resistance, impact resistance and salt spray resistance of the composite coating. The sample preparation is carried out according to the method in HG / T 5173-2017 Waterborne Primer for Rust-inhibiting Coating. The test results are as follows:

[0028] Table 1 Properties of Graphene-Modified Rust Conversion Coating

[0029]

[0030] Table 2 Properties of Graphene-Modified Rust Conversion and Epoxy Zinc-Rich Composite Coating

[0031]

[0032]

[0033] From the test results, the steel rust-free coating maintenance material prepared in the present invention can effectively penetrate more than 200 μm into the rust products. When used alone, it has good physical properties of the coating film, high rust conversion rate, and the neutral salt spray resistance can reach more than 300 h. According to theoretical calculation, in the C3 corrosion environment, the anti-corrosion service life can reach more than 10 years, which can meet the requirements of most anti-corrosion designs.

[0034] By using in combination with an epoxy zinc-rich primer (the zinc-rich primer used in the present invention has a metal zinc content of 80% in the non-volatile matter), after 600 h under neutral salt spray, in the examples with carbon nanotubes added, the unidirectional corrosion spread at the scratch is less than 2.0 mm, meeting the requirements of the HG / T 3668-2020 zinc-rich primer standard. In Example 4, however, since no carbon nanotube material was added, after 168 h of salt spray resistance, the unidirectional corrosion spread at the scratch exceeded 2 mm. This shows that after adding the carbon nanotube material, under the action of the carbon nanotubes, the zinc in the zinc-rich primer can be connected to the steel substrate, and electrons are transferred to the steel substrate through the corrosion of zinc powder, so that the metal exposed at the scratch is effectively protected, playing a cathodic protection function.

[0035] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. An iron-free rust removal and coating maintenance material, characterized in that, Comprising: Selecting an inorganic modified waterborne resin as the main raw material, adding a variety of rust-proof materials, auxiliary materials and water, and mixing and stirring to prepare. The component weight ratio is as follows: 30 - 50 parts of inorganic modified waterborne resin, 1.0 - 6.0 parts of rust converter, 1.0 - 5.0 parts of carbon nanotube dispersion, 5.0 - 10 parts of aluminum tripolyphosphate, 5.0 - 15 parts of filler, 0.2 - 0.6 parts of rheological aid, 0.2 - 0.5 parts of defoamer, 1.0 - 2.0 parts of film-forming aid, 20 - 30 parts of water.

2. The iron rust-free coating maintenance material according to claim 1, characterized in that: Comprising: The inorganic modified waterborne polymer resin is nano-silica modified epoxy resin, nano-silica modified acrylic resin, nano-silica modified vinyl chloride resin, nano-silica modified styrene-acrylic emulsion or nano-silica modified vinyl acetate-acrylic emulsion, etc.

3. The iron-free rust removal and painting maintenance material according to claim 1, wherein The rust converter includes iron phosphate, iron chromate, tannic acid phosphate system, mangrove tannin series, potassium ferrocyanide series, phytic acid series, chelating phosphate series, etc.

4. The iron-free rust removal and painting maintenance material according to claim 1, characterized in that, The carbon nanotube dispersion slurry includes a water-based dispersion slurry of carbon nanotubes, with a carbon nanotube content ≥ 5% and a volume resistivity ≤ 20Ω.

5. The iron-free rust removal and painting maintenance material according to claim 1, wherein The filler includes nano-silica, nano-titanium dioxide, phosphorus iron powder, etc., which are used to improve the hardness, wear resistance and adhesion of the rust conversion coating.

6. A preparation method of an iron-free rust-removing coating maintenance material, characterized in that, Comprising: Put 20 - 30 parts of water and 0.2 - 0.5 parts of defoamer into a paint mixing tank, stir evenly, then slowly add 5 - 10 parts of aluminum tripolyphosphate and 5 - 15 parts of filler, disperse at a high speed of 2000 - 2500 rpm for 20 - 30 min, then reduce the speed to 1000 - 1500 rpm, then add 2 - 6 parts of rust converter and 1.0 - 10.0 parts of carbon nanotube dispersion slurry, continue to stir for 20 - 30 min, then reduce the speed to 800 - 1000 rpm, then add 30 - 50 parts of inorganic modified waterborne resin and continue to stir for 10 - 15 min, then add 1 - 2 parts of film-forming aid and 0.2 - 0.6 parts of rheological aid, reduce the speed to 500 - 600 rpm, add 1 - 6 parts of rust converter, continue to stir for 10 - 20 min, and then carry out filtration and packaging to obtain the graphene modified rust conversion anti-corrosion coating.

Images