Rust coating for communication iron tower and preparation method of rust coating

Abstract

The invention discloses a rusty coating for a communication tower and a preparation method of the rusty coating, and relates to the technical field of paints.The rusty coating takes alpha, omega-dihydroxy polysiloxane as basic resin, and a proper coupling agent, a cross-linking agent, a corrosion stabilizer, a corrosion conversion agent, pigment filler and the like are matched to form a new rusty coating formula which can be cured at the normal temperature. The rusted coating has excellent permeability, waterproofness and film-forming adhesive force, can be suitable for corrosion prevention and maintenance of rusted communication iron towers, and has better practical value.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a rust-resistant coating for communication towers and a preparation method thereof. Background Art

[0002] Metal corrosion refers to the damage of metal materials by the surrounding medium. Metal corrosion will cause the material thickness to decrease and the strength to reduce. When the corrosion develops to a certain extent, sudden damage such as perforation and leakage will occur. Therefore, steel structures and equipment in corrosive environments need to be protected on the surface. The most common method is to use coatings for protection.

[0003] Before conventional coatings are applied, in order to obtain better coating adhesion and film-forming properties, the surface to be coated needs to be treated, such as electric tool grinding, sandblasting, water sandblasting and laser rust removal. Surface treatment requires additional tools, manpower and energy. Incomplete surface treatment will cause premature damage and failure of the coating layer. In addition, conventional coatings are usually divided into primer, intermediate paint (if necessary) and topcoat. There needs to be a coating interval between each coating. The construction period is long. In case of rainy weather, the project period is more uncertain.

[0004] Due to the additional manpower and resource costs required for surface treatment, the research and development of rust-resistant coatings has gradually increased. The current more mature method uses a combination of primer and topcoat to paint the rusted surface. However, the interval between primer and topcoat increases the complexity of the operation and prolongs the construction time. Therefore, the application of primer-topcoat coatings has attracted more and more attention. There are various problems with existing primer-topcoat coatings. For example, alkyd and acrylic coatings have limited weather resistance life, epoxy coatings are prone to discoloration and powdering, and fluororesin and fluorosilicone resin coatings have long life but high cost. In contrast, silicone coatings have moderate life and cost, but usually require high temperature curing or catalytic curing at room temperature using organotin catalysts that are harmful to the human body.

[0005] Communication towers are usually located outdoors or on the roofs of residential buildings. After the galvanized layer fails, corrosion damage occurs. Surface treatment is difficult during corrosion maintenance, and the maintenance operation is difficult and risky. It is very necessary to develop a rust-proof base and surface all-in-one coating for communication towers that requires low surface treatment, requires fewer operating procedures, is easy to construct, provides long-term protection, and cures at room temperature. Summary of the invention

[0006] The purpose of the present invention is to provide a rust-resistant coating for communication towers and a preparation method thereof. The rust-resistant coating can be cured directly at room temperature, has excellent permeability, waterproofness and film-forming adhesion, can be used for the anti-corrosion maintenance of rusted communication towers, and also has good weather resistance.

[0007] The embodiment of the present invention is achieved as follows: A rust-resistant coating for a communication tower, comprising, by weight: 60-100 parts of α,ω-dihydroxy polysiloxane, 20-40 parts of cross-linking agent, 5-8 parts of coupling agent, 28-32 parts of inorganic pigments and fillers, 1-8 parts of rust stabilizer, 1-8 parts of rust converter, 1-2 parts of defoamer, and 15-25 parts of solvent; The corrosion stabilizer includes at least one of aluminum tripolyphosphate and zinc phosphate; and the corrosion converter includes phosphoric acid.

[0008] A method for preparing the above-mentioned rust-resistant coating for communication towers, comprising: The α,ω-dihydroxy polysiloxane and the solvent are mixed and stirred for 10 to 30 minutes to fully disperse them to obtain a mixed solution; Add the cross-linking agent to the mixture and stir for 10-30 minutes; Add inorganic pigments and fillers and continue stirring for 30-120 minutes; Add rust stabilizer and rust converter, and continue stirring for 10-30 minutes; Add defoamer and continue stirring for 10-30 minutes; Add the coupling agent and continue stirring for 5 to 10 minutes to obtain a rust-free coating.

[0009] The beneficial effects of the embodiments of the present invention are: The present invention provides a rust-resistant coating for communication towers and a preparation method thereof. The rust-resistant coating is based on α, ω-dihydroxy polysiloxane as a base resin, and is matched with suitable coupling agents, cross-linking agents, rust stabilizers, rust converters, pigments and fillers to form a new coating formula that can be cured at room temperature and can be rust-resistant. The rust-resistant coating has excellent permeability, water resistance and film-forming adhesion, can be used for the anti-corrosion maintenance of rusted communication towers, and has good practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 The schematic diagram is a principle diagram of the coupling agent of the present invention being combined with the pigment and filler after being hydrolyzed. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0013] The following is a detailed description of a rust-resistant coating for a communication tower and a preparation method thereof according to an embodiment of the present invention.

[0014] A rust-resistant coating for a communication tower, comprising, by weight: 60-100 parts of α,ω-dihydroxy polysiloxane, 20-40 parts of cross-linking agent, 5-8 parts of coupling agent, 28-32 parts of inorganic pigments and fillers, 1-8 parts of rust stabilizer, 1-8 parts of rust converter, 1-2 parts of defoamer, and 15-25 parts of solvent; The corrosion stabilizer includes at least one of aluminum tripolyphosphate and zinc phosphate; and the corrosion converter includes phosphoric acid.

[0015] This rust-resistant coating can be well used for the protection of steel rusted surfaces. It only requires simple cleaning of the surface rust, dust, leaves and other debris, and then direct coating. No additional power tool surface treatment is required, and the coating can be cured at room temperature. It can be painted with a slight amount of water and does not require heating. The primer and topcoat are one type, saving construction time. The cured coating has good weather resistance and adhesion, and can better serve actual anti-corrosion projects such as communication towers that are not convenient for surface treatment.

[0016] The present invention uses phosphoric acid as a rust converter. On the one hand, phosphoric acid can replace the traditional organotin catalyst, accelerate the hydrolysis reaction of the cross-linking agent, and promote the cross-linking of α, ω-dihydroxy polysiloxane to form a network structure, thereby reducing the harm of the coating to the human body. On the other hand, part of the phosphoric acid contacts the rust on the surface of the iron tower to generate phosphates to enhance the bonding force between the organosilicon network and the rusted surface, enhance the adhesion and shielding performance of the entire system, and promote the anti-corrosion effect. The rust stabilizer also uses phosphates and can also contact and react with the rust to improve adhesion. Preferably, the mass ratio of the rust converter to the rust stabilizer is 1:4~10. Within the above ratio range, the reaction effect on rust is better.

[0017] Furthermore, the crosslinking agent includes at least one of methyltrimethoxysilane, ethyl orthosilicate and methyltriacetoxysilane. The crosslinking agent can interconnect the active functional groups in the α,ω-dihydroxy polysiloxane to form a network structure.

[0018] The inorganic pigments and fillers include at least one of zinc oxide, titanium dioxide, silicon dioxide, mica powder, zinc borate and polytetrafluoroethylene; the particle size of the inorganic pigments and fillers is 10 to 50 μm. The present invention uses micro-powder-level inorganic pigments and fillers, which can effectively improve the overall fluidity and permeability of the coating. When in contact with rust, it can squeeze out the air in the pores of the rust, absorb the moisture of the rust, and achieve coating and penetration of the rust, thereby enhancing the shielding ability of the coating system.

[0019] The coupling agent includes at least one of a silane coupling agent and a phthalate coupling agent. The hydroxyl groups formed after the hydrolysis of the silane coupling agent and the phthalate coupling agent can form chemical bonds with the inorganic pigments and fillers (such as Figure 1 As shown in the figure, the inorganic system is changed into an organic system, which improves the filling and dispersion effect of the pigment in the network cross-linking of the silicone resin; in addition, the modified inorganic pigment can be better compatible with the silicone resin, has a good integrated film-forming effect, enhances the shielding performance, can better isolate corrosive media such as water, salt and air pollutants, and enhances the anti-corrosion effect of the coating system.

[0020] Furthermore, the defoamer includes tributyl phosphate. The defoamer can eliminate bubbles and improve production efficiency. The solvent includes at least one of xylene, cyclohexanone, and butyl acetate. After careful screening by the inventor, the above solvent has a better dispersion effect on the entire coating and can improve the uniformity and fluidity of the coating.

[0021] Optionally, the viscosity of the α,ω-dihydroxy polysiloxane is 20000~40000 mm 2 / s. Within the above viscosity range, the coating as a whole can obtain a better cross-linking density, thereby having better adhesion and shielding performance.

[0022] The rust-resistant coating material uses micro-powder-grade inorganic pigments and fillers to coat and penetrate the rust to achieve physical bonding; then the coupling agent, rust stabilizer, rust converter and the chemical bonding between rust and inorganic pigments and fillers are used to achieve a double stabilization effect, thereby significantly improving the overall adhesion and shielding performance of the coating. The rust-resistant coating material does not require surface treatment. It only needs to clean the loose rust and debris on the surface, and can be directly applied on the rusty surface. The rust-resistant coating material is hydrolyzed and cross-linked and cured at room temperature, and does not require heating. It can still be applied when the air humidity is ≥85% and the substrate has slight condensation. The primer and topcoat are of one kind, which can be applied wet-on-wet, and does not require a fixed coating interval, reducing the application time.

[0023] The embodiment of the present invention also provides a method for preparing the above-mentioned rust-resistant coating for communication towers, which comprises: S1. The α,ω-dihydroxy polysiloxane and the solvent are mixed and stirred for 10 to 30 minutes to be fully dispersed to obtain a mixed solution; S2. Add the crosslinking agent to the mixture and stir for 10 to 30 minutes; S3. Add inorganic pigments and fillers and continue stirring for 30 to 120 minutes; S4. Add rust stabilizer and rust converter, and continue stirring for 10 to 30 minutes; S5. Add defoamer and continue stirring for 10-30 minutes; S6. Add coupling agent and continue stirring for 5 to 10 minutes to obtain rust-free coating.

[0024] Furthermore, the stirring speed is 300-1000 rpm. At this speed, the components can be mixed more fully. Optionally, before adding the defoamer, the mixed solution is ground to a particle size of 10-50 μm. The grinding is mainly for inorganic pigments and fillers, which are ground to a micro powder level to achieve a better adhesion effect.

[0025] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0026] Example 1 This embodiment provides a rust-resistant coating, which comprises, by weight: 100 parts of α,ω-dihydroxypolysiloxane, 20 parts of tetraethyl orthosilicate, 5 parts of silane coupling agent (KH570), 30 parts of inorganic pigments and fillers (mica powder: zinc oxide: titanium dioxide: silicon dioxide = 1:1:1:2), 2.7 parts of aluminum tripolyphosphate, 0.3 parts of phosphoric acid, 1 part of tributyl phosphate, and 20 parts of cyclohexanone.

[0027] The preparation method thereof comprises: S1. The α,ω-dihydroxy polysiloxane and the solvent are mixed and stirred for 10 to 30 minutes to be fully dispersed to obtain a mixed solution; S2. Add the crosslinking agent to the mixture and stir for 10 to 30 minutes; S3. Add inorganic pigments and fillers and continue stirring for 30 to 120 minutes; S4. Add rust stabilizer and rust converter, and continue stirring for 10 to 30 minutes; S5. The mixed solution formed in step S4 is ground to a particle size of 10 to 50 μm; S6. Add defoamer and continue stirring for 10-30 minutes; S7. Add coupling agent and continue stirring for 5 to 10 minutes to obtain rust-free coating.

[0028] Example 2 This embodiment provides a rust-resistant coating, which comprises, by weight: 80 parts of α,ω-dihydroxypolysiloxane, 20 parts of methyltrimethoxysilane, 4.5 parts of silane coupling agent (KH570), 1.5 parts of titanate coupling agent (TMC), 32 parts of inorganic pigments and fillers (mica powder: zinc borate: zinc oxide: titanium dioxide: silicon dioxide = 1:1:1:1:2), 4 parts of aluminum tripolyphosphate, 1 part of phosphoric acid, 1.2 parts of tributyl phosphate, and 20 parts of butyl acetate.

[0029] The preparation method thereof comprises: S1. The α,ω-dihydroxy polysiloxane and the solvent are mixed and stirred for 10 to 30 minutes to be fully dispersed to obtain a mixed solution; S2. Add the crosslinking agent to the mixture and stir for 10 to 30 minutes; S3. Add inorganic pigments and fillers and continue stirring for 30 to 120 minutes; S4. Add rust stabilizer and rust converter, and continue stirring for 10 to 30 minutes; S5. The mixed solution formed in step S4 is ground to a particle size of 10 to 50 μm; S6. Add defoamer and continue stirring for 10-30 minutes; S7. Add coupling agent and continue stirring for 5 to 10 minutes to obtain rust-free coating.

[0030] Example 3 This embodiment provides a rust-resistant coating, which comprises, by weight: 60 parts of α,ω-dihydroxypolysiloxane, 40 parts of crosslinking agent (methyltrimethoxysilane:ethyl orthosilicate = 10:1), 8 parts of silane coupling agent (KH570), 28 parts of inorganic pigments and fillers (mica powder: polytetrafluoroethylene powder: zinc oxide powder: titanium dioxide: silicon dioxide = 1:1:1:2:2), 4.8 parts of zinc phosphate, 1.2 parts of phosphoric acid, 1.5 parts of tributyl phosphate, and 20 parts of cyclohexanone.

[0031] The preparation method thereof comprises: S1. The α,ω-dihydroxy polysiloxane and the solvent are mixed and stirred for 10 to 30 minutes to be fully dispersed to obtain a mixed solution; S2. Add the crosslinking agent to the mixture and stir for 10 to 30 minutes; S3. Add inorganic pigments and fillers and continue stirring for 30 to 120 minutes; S4. Add rust stabilizer and rust converter, and continue stirring for 10 to 30 minutes; S5. The mixed solution formed in step S4 is ground to a particle size of 10 to 50 μm; S6. Add defoamer and continue stirring for 10-30 minutes; S7. Add coupling agent and continue stirring for 5 to 10 minutes to obtain rust-free coating.

[0032] Comparative Example 1 This comparative example provides a rust-bearing coating, the composition and preparation method of which are substantially the same as those of Example 1, except that no rust conversion agent is used.

[0033] Comparative Example 2 This comparative example provides a rust-resistant coating, the composition and preparation method of which are basically the same as those of Example 1, except that the coupling agent is replaced by a phosphate coupling agent (TPP).

[0034] Comparative Example 3 This comparative example provides a rust-resistant coating, the composition and preparation method of which are basically the same as those of Example 1, except that the coupling agent is replaced by a borate coupling agent (TMSB).

[0035] Comparative Example 4 This comparative example provides a rust-resistant coating, the composition and preparation method of which are substantially the same as those of Example 1, except that no pigment or filler is used.

[0036] Comparative Example 5 This comparative example provides a rust-bearing coating, the composition and preparation method of which are substantially the same as those of Example 1, except that during the grinding, the rust-bearing coating is ground to 200-300 μm.

[0037] Test example In this test example, a Q235 steel plate was taken out after 72 hours of neutral salt spray test, and the surface salt particles and loosely attached rust were cleaned and washed, and then dried for use. After the rust-bearing coating provided by Examples 1 to 3 and Comparative Examples 1 to 5 were prepared, the rust-bearing surfaces of the treated Q235 steel plates were immediately coated, and after coating, they were fully dried for 7 days in a normal atmospheric environment at room temperature, and then tested. The test results and test methods are shown in Table 1.

[0038] Table 1. Test results and test methods It can be seen from Table 1 that the rust-bearing coating prepared by Examples 1 to 3 of the present invention has better adhesion, and the adhesion to the rust-bearing surface reaches more than 4.0 MPa. At the same time, it has better low-frequency electrochemical impedance, reaching 1.4×10 10 Ω·cm 2 From the above, it can be seen that it has good shielding performance and can play an anti-rust effect. After the salt spray test, the coating can still maintain good adhesion and low-frequency electrochemical resistance, and the overall performance is excellent.

[0039] In contrast, in Comparative Example 1, no etching conversion agent was used. Without the participation of etching conversion agent, the hydrolysis of the crosslinking agent was slow, and the crosslinking of the silicone resin was affected, which directly reduced the adhesion of the coating to 2.26Mpa. At the same time, the shielding performance was also affected, and the low-frequency electrochemical resistance was only 1.78×10 6 Ω·cm 2 In addition, after the salt spray test, the performance of the coating declined seriously, the adhesion dropped to 1.31 Mpa, and the low-frequency electrochemical resistance also dropped to 1.16×10 4 Ω·cm 2 After 300 hours outdoors, the coating cracked.

[0040] Comparative Examples 2 and 3 respectively used phosphate coupling agents and borate coupling agents, and their adhesion and low-frequency electrochemical resistance were significantly reduced, indicating that the choice of coupling agent has a significant impact on the overall performance of the coating. Phosphates and borates have a relatively stronger binding force with zinc ions in pigments and fillers. After contacting with pigments and fillers, they are easy to form stable compounds and precipitate, which in turn destroys the stability of the interface and is the main reason for the deterioration of adhesion and shielding performance. In addition, the binding force of phosphates is relatively stronger, showing a more serious decline in performance, with adhesion reaching only 2.57 Mpa and low-frequency electrochemical resistance reaching only 2.39×10 7 Ω·cm 2 After the salt spray test, obvious blistering and rusting occurred, and various performances declined seriously. After 300 hours outdoors, the coating cracked.

[0041] Comparative Example 4 did not use pigments and fillers, and the adhesion was reduced to 2.85MPa, and the low-frequency electrochemical resistance was only 2.48×10 8 Ω·cm 2 Comparative Example 5 uses non-micronized pigments and fillers, which, although improved to a certain extent compared with Comparative Example 4, still cannot reach the performance of Examples 1 to 3 of the present invention. This fully demonstrates that the physical bonding of micronized pigments and fillers through penetration and coating will also affect the performance of the coating.

[0042] In summary, the present invention provides a rust-resistant coating for communication towers and a preparation method thereof. The rust-resistant coating uses α, ω-dihydroxypolysiloxane as a base resin, and is matched with suitable coupling agents, cross-linking agents, rust stabilizers, rust converters, pigments and fillers to form a new coating formula that can be cured at room temperature and can be rust-coated. The rust-resistant coating has excellent permeability, water resistance and film-forming adhesion, can be used for the anti-corrosion maintenance of rusted communication towers, and has good practical value.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A rust-resistant coating for communication towers, characterized in that: In parts by weight, it includes: 60-100 parts of α,ω-dihydroxy polysiloxane, 20-40 parts of cross-linking agent, 5-8 parts of coupling agent, 28-32 parts of inorganic pigments and fillers, 1-8 parts of rust stabilizer, 1-8 parts of rust converter, 1-2 parts of defoamer, and 15-25 parts of solvent; Wherein, the corrosion stabilizer includes at least one of aluminum tripolyphosphate and zinc phosphate; and the corrosion converter includes phosphoric acid.

2. The rust-resistant coating according to claim 1, characterized in that: The crosslinking agent includes at least one of methyltrimethoxysilane, ethyl orthosilicate and methyltriacetoxysilane.

3. The rust-resistant coating according to claim 1, characterized in that: The coupling agent includes at least one of a silane coupling agent and a phthalate coupling agent.

4. The rust-resistant coating according to claim 1, characterized in that: The defoaming agent includes tributyl phosphate.

5. The rust-proof coating according to claim 1, characterized in that: The solvent includes at least one of xylene, cyclohexanone and butyl acetate.

6. The rust-resistant coating according to claim 1, characterized in that: The viscosity of the α,ω-dihydroxy polysiloxane is 20000 ~ 40000 mm 2 / s.

7. The rust-resistant coating according to claim 1, characterized in that: The inorganic pigment filler includes at least one of zinc oxide, titanium dioxide, silicon dioxide, mica powder, zinc borate and polytetrafluoroethylene; the particle size of the inorganic pigment filler is 10-50 μm.

8. A method for preparing a rust-resistant coating for a communication tower according to any one of claims 1 to 7, characterized in that: include: The α,ω-dihydroxy polysiloxane and the solvent are mixed and stirred for 10 to 30 minutes to fully disperse them to obtain a mixed solution; Add the cross-linking agent to the mixed solution and stir for 10 to 30 minutes; Add the inorganic pigment and filler, and continue stirring for 30 to 120 minutes; Add the rust stabilizer and the rust converter, and continue stirring for 10 to 30 minutes; Add the defoamer and continue stirring for 10 to 30 minutes; The coupling agent is added and stirring is continued for 5 to 10 minutes to obtain the rust-resistant coating.

9. The preparation method according to claim 8, characterized in that: The stirring speed is 300~1000 rpm.

10. The preparation method according to claim 8, characterized in that: Before adding the defoaming agent, the mixed solution is first ground to a particle size of 10-50 μm.

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