Low-surface-energy polyethylene anti-corrosion and anti-fouling special material as well as preparation method and application thereof

Abstract

The invention discloses a low-surface-energy polyethylene anti-corrosion and anti-fouling special material as well as a preparation method and application thereof. The special grain comprises the following components in parts by weight: 20-40 parts of high-density polyethylene, 40-60 parts of low-density polyethylene, 10-25 parts of a compatibilizer, 0.1-0.3 part of an antioxidant, 0.5-2 parts of a flatting agent, 0.5-5 parts of a fluorocarbon functional material and 0.5-5 parts of a low-surface-energy auxiliary component. The special material has good stability and low coating surface energy, and can prevent or delay the adhesion of microorganisms on the coating surface by utilizing the low surface energy property while playing a stable anti-corrosion role, so that the special material also plays an anti-fouling role. The special material is a thermoplastic solid powder coating, can be directly coated and does not contain solvents or volatile components, and the coating process is simple, green and environment-friendly. And after coating, the coating intrinsic has low surface energy and excellent weather resistance, and has a good application prospect in a high-temperature, high-humidity and high-salt marine environment.

Description

Technical Field

[0001] The present invention relates to the field of powder coatings, and more specifically, to a low-surface-energy polyethylene anticorrosion and antifouling special material, and a preparation method and application thereof. Background Art

[0002] The ocean is an extremely complex and harsh environment. Metal materials will be severely corroded under the influence of the marine environment for a long time. Marine corrosion is a harmful electrochemical process that will cause serious damage to metal structures and greatly reduce their service life. While causing safety accidents, it is also accompanied by environmental pollution, waste of resources and economic losses. It has become one of the key issues restricting the development of related marine industries. Therefore, it is of great significance to develop new anti-corrosion and anti-fouling technologies, especially green and environmentally friendly anti-corrosion and anti-fouling technologies that can be effectively applied in high temperature, high humidity and high salt fog marine environments. Powder coating is an environmentally friendly coating that does not contain organic solvents and has a solid content of 100%. Whether in the production or construction process, there is no organic solvent, which is both environmentally friendly and safe. Among them, thermoplastic powder coating uses its own thermoplastic properties to cure into a film. The coating formula does not contain a curing agent, and no chemical reaction occurs during the film formation process. It can be applied by fluidized bed coating, dipping, electrostatic spraying, flame spraying and other methods. Among them, polyethylene-based thermoplastic powder has been widely used in corrosion protection of pipelines, highway networks, etc. due to its low raw material cost, wide source, chemical resistance, weather resistance, and good construction performance. In addition, the particularity of the marine environment has led to a wide variety of marine organisms. Some marine organisms often attach to the surface of ships below the waterline or marine equipment, causing a series of serious problems, such as reducing the speed of ships, corroding and damaging offshore or underwater structures, etc. Therefore, while preventing corrosion, how to effectively avoid marine biofouling is a hot and difficult issue in the field of marine science. The antifouling agents in traditional antifouling coatings are usually highly toxic organic matter, heavy metals and their compounds to solve the problem of anticorrosion and antifouling of marine coatings. For example, patent CN112955513A uses cuprous oxide, cuprous thiocyanate, etc. as the main antifouling agents; patent CN113122042 uses FeAsO4-2H2O as a functional additive for antifouling coatings, and releases arsenic and other elements through FeAsO4-2H2O to play an antifouling role. The large-scale use of these toxic antifouling agents has seriously polluted the marine environment. Therefore, at present, the research direction of marine ship anticorrosion and antifouling coatings at home and abroad is environmentally friendly, low-toxic or non-toxic coatings. Summary of the invention

[0003] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a low-surface-energy polyethylene anticorrosion and antifouling special material and its preparation method and application. The special material provided in the present invention is in powder form, has good stability and contains fluorine-containing functional components. Through the synergistic effect of fluorocarbon functional components and low-surface-energy fluorine-containing resins, it has low surface energy characteristics after forming a film on the metal surface, which can prevent or delay the attachment of microorganisms on the coating surface, thereby also playing an antifouling effect.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In one aspect, the present invention provides a low surface energy polyethylene anticorrosion and antifouling special material, comprising the following components in parts by weight:

[0006] 20-40 parts of high-density polyethylene, 40-60 parts of low-density polyethylene, 10-25 parts of compatibilizer, 0.1-0.3 parts of antioxidant, 0.5-2 parts of leveling agent, 0.5-5 parts of fluorocarbon functional material, and 0.5-5 parts of low surface energy auxiliary component.

[0007] Furthermore, the polyethylene anticorrosion and antifouling special material is a thermoplastic solid powder coating, which can be directly applied, does not contain solvents or volatile components, and has a simple and green coating process. After coating, the coating has low surface energy and excellent weather resistance, and has good application prospects in high temperature, high humidity and high salt marine environments.

[0008] Furthermore, the high-density polyethylene is a blow molding or casting grade high-density polyethylene resin with a melt index of 0.5-3 g / 10 min.

[0009] In some specific examples, the amount of high-density polyethylene includes but is not limited to 30-40 parts, 30 parts, 40 parts, etc.

[0010] Furthermore, the melt index of the low-density polyethylene is 10-20 g / 10 min.

[0011] In some specific examples, the amount of the low-density polyethylene includes but is not limited to 40-50 parts, 40-45 parts, 45-60 parts, 50-60 parts, 40 parts, 45 parts, 50 parts, 60 parts, etc.

[0012] Furthermore, the mass ratio of the high-density polyethylene to the low-density polyethylene is 1:1-1:3.

[0013] In some specific examples, the mass ratio of the high-density polyethylene to the low-density polyethylene includes but is not limited to 1:1-1:2, 1:1-1:1.5, 1:1-1:1.25, 1:1-1:1.125, 1:1, 1:2, 1:1.25, 1:1.125, etc.

[0014] Furthermore, the compatibilizer is maleic anhydride grafted polyethylene.

[0015] In some specific examples, the amount of the compatibilizer used includes but is not limited to 10-15 parts, 10-20 parts, 15-25 parts, 15-20 parts, 20-25 parts, 10 parts, 15 parts, 20 parts, 25 parts, etc.

[0016] Furthermore, the antioxidant is antioxidant 1010, antioxidant 168, antioxidant 1076 or antioxidant 2266.

[0017] In some specific examples, the amount of the antioxidant includes but is not limited to 0.1-0.2 parts, 0.2-0.3 parts, 0.2 parts, 0.3 parts, etc.

[0018] Furthermore, the leveling agent is polyethyl acrylate and / or polybutyl acrylate.

[0019] In some specific examples, the amount of the leveling agent includes but is not limited to 1-2 parts, 1 part, 2 parts, etc.

[0020] Furthermore, the fluorocarbon functional material is fluorinated graphite or fluorinated graphene, wherein the mass ratio of F to C in the fluorocarbon functional material is greater than 1.0. In this case, the surface energy of the obtained special material can be well reduced.

[0021] In some specific examples, the amount of the fluorocarbon functional material used includes but is not limited to 1-4 parts, 1-3 parts, 1-2 parts, 2-4 parts, 3-4 parts, 2-3 parts, 1 part, 2 parts, 3 parts, 4 parts, etc.

[0022] Furthermore, the low surface energy auxiliary component is polytetrafluoroethylene powder, wherein the particle size of the polytetrafluoroethylene powder is ≤20 μm.

[0023] In some specific examples, the amount of the low surface energy auxiliary component includes but is not limited to 0.5-4 parts, 0.5-2 parts, 2-5 parts, 2-4 parts, 4-5 parts, 0.5 parts, 2 parts, 4 parts, 5 parts, etc.

[0024] Furthermore, the mass ratio of the fluorocarbon functional material to the low surface energy auxiliary component is 10:1-0.2:1.

[0025] In some specific examples, the mass ratio of the fluorocarbon functional material to the low surface energy auxiliary component includes but is not limited to 8:1-0.2:1, 8:1-0.75:1, 8:1-1:1, 8:1-1.5:1, 1.5:1-0.2:1, 1.5:1-0.75:1, 1.5:1-1:1, 1:1-0.2:1, 1:1-0.75:1, 0.75:1-0.2:1, 8:1, 1.5:1, 1:1, 0.75:1, 0.2:1, etc.

[0026] The fluorocarbon functional material and the low surface energy auxiliary component have a synergistic effect of increasing the contact angle between the powder coating and the water surface and reducing the surface energy.

[0027] In another aspect, the present invention provides a method for preparing the polyethylene anticorrosion and antifouling special material with low surface energy as described above, comprising the following steps:

[0028] The raw material components are mixed evenly, extruded and granulated at a temperature of 170-220° C., and then ground to obtain a powdery material. After the powdery material is sieved, the low-surface-energy polyethylene anticorrosion and antifouling special material is obtained.

[0029] Furthermore, the grinding method is a low-temperature grinding process.

[0030] Furthermore, the screening is through a 100-mesh sieve.

[0031] In another aspect, the present invention provides the use of the low surface energy polyethylene anti-corrosion and anti-fouling special material as described above as an anti-corrosion coating.

[0032] The beneficial effects of the present invention are as follows:

[0033] The polyethylene anti-corrosion and anti-fouling special material provided by the present invention is in powder form as an anti-corrosion coating. It has good mechanical properties, leveling properties, environmental stress cracking resistance, heat aging resistance, UV aging resistance, pressure resistance, corrosion resistance and low surface energy characteristics, and is suitable for processes such as dipping, flame spraying and thermal spraying. Compared with the prior art, the present invention adds low surface energy functional components such as fluorinated graphite or fluorinated graphene powder particles to the high / low density composite polyethylene material. Since the CF functional group has a large bond energy and a small polarity and has a layered structure, it has an extremely low surface energy (its surface free energy is 6±3(10 3 J / m 2 )), which plays a role in reducing the surface energy of polyethylene powder coating.

[0034] In the preparation method provided by the present invention, it is found that the polyethylene powder coating is directly prepared by the processing method of extrusion blending and then crushing. Due to the aggregation of CF, it cannot be evenly dispersed in the matrix and the surface energy of the matrix material cannot be significantly improved. Therefore, by synergistic effect with fluororesin PTFE and utilizing the non-self-cohesion of PTFE, the surface energy of polyethylene powder coating can be significantly reduced by evenly dispersing CF in the resin matrix. And preferably, fluorinated graphite with a fluorine-carbon ratio greater than 1.2 has better thermal stability, is not corroded by strong acids and strong bases, and has better weather resistance in high temperature, high humidity and high salt marine environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0036] Figure 1 A graph showing the contact angle with water of Example 1 is shown.

[0037] Figure 2 The contact angle graph of Comparative Example 2 with water is shown. DETAILED DESCRIPTION

[0038] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0039] Example 1

[0040] A low-surface-energy polyethylene anticorrosion and antifouling special material comprises the following components in parts by weight: 30 parts of high-density polyethylene resin (melt index 2 g / 10 min), 60 parts of low-density polyethylene (melt index 20 g / 10 min), 10 parts of maleic anhydride grafted polyethylene, 0.2 parts of antioxidant 1010, 1 part of leveling agent, 4 parts of fluorinated graphite (the average powder diameter is 8 μm, F / C=1.3), and 0.5 parts of polytetrafluoroethylene micropowder (the average diameter is 18 μm).

[0041] The preparation of the above-mentioned low surface energy polyethylene anti-corrosion and anti-fouling special material comprises the following steps:

[0042] The above raw materials are added into a high-speed blender, mixed evenly, and then extruded and granulated by a twin-screw extruder at a temperature of 170-220°C to obtain a polyethylene masterbatch; the obtained polyethylene masterbatch is dried and ground by a low-temperature grinding process to obtain polyethylene powder, and then passed through a 100-mesh sieve to obtain the low-surface-energy polyethylene anti-corrosion and anti-fouling special material.

[0043] Example 2

[0044] A low-surface-energy polyethylene anticorrosion and antifouling special material comprises the following components in parts by weight: 40 parts of high-density polyethylene resin (melting index 0.9 g / 10 min), 40 parts of low-density polyethylene (melting index 16 g / 10 min), 20 parts of maleic anhydride grafted polyethylene, 0.3 parts of antioxidant 1010, 1 part of leveling agent, 3 parts of fluorinated graphite (the average powder diameter is 8 μm, F / C=1.0), and 2 parts of polytetrafluoroethylene micropowder (the average diameter is 18 μm).

[0045] The preparation of the above-mentioned low surface energy polyethylene anti-corrosion and anti-fouling special material comprises the following steps:

[0046] The above raw materials are added into a high-speed blender, mixed evenly, and then extruded and granulated by a twin-screw extruder at a temperature of 170-220°C to obtain a polyethylene masterbatch; the obtained polyethylene masterbatch is dried and ground by a low-temperature grinding process to obtain polyethylene powder, and then passed through a 100-mesh sieve to obtain the low-surface-energy polyethylene anti-corrosion and anti-fouling special material.

[0047] Example 3

[0048] A low-surface-energy polyethylene anticorrosion and antifouling special material comprises the following components in parts by weight: 40 parts of high-density polyethylene resin (melt index 0.9 g / 10 min), 50 parts of low-density polyethylene (melt index 16 g / 10 min), 25 parts of maleic anhydride grafted polyethylene, 0.3 parts of antioxidant 1010, 1 part of leveling agent, 1 part of fluorinated graphite (the average powder diameter is 10 μm, F / C=1.4), and 5 parts of polytetrafluoroethylene micropowder (the average diameter is 18 μm).

[0049] The preparation of the above-mentioned low surface energy polyethylene anti-corrosion and anti-fouling special material comprises the following steps:

[0050] The above raw materials are added into a high-speed blender, mixed evenly, and then extruded and granulated by a twin-screw extruder at a temperature of 170-220°C to obtain a polyethylene masterbatch; the obtained polyethylene masterbatch is dried and ground by a low-temperature grinding process to obtain polyethylene powder, and then passed through a 100-mesh sieve to obtain the low-surface-energy polyethylene anti-corrosion and anti-fouling special material.

[0051] Example 4

[0052] A low-surface-energy polyethylene anticorrosion and antifouling special material comprises the following components in parts by weight: 40 parts of high-density polyethylene resin (melt index 0.9 g / 10 min), 45 parts of low-density polyethylene (melt index 16 g / 10 min), 15 parts of maleic anhydride grafted polyethylene, 0.3 parts of antioxidant 1010, 1 part of leveling agent, 2 parts of fluorinated graphene (the average powder diameter is 10 μm, F / C=1.1), and 2 parts of polytetrafluoroethylene micropowder (the average diameter is 15 μm).

[0053] The preparation of the above-mentioned low surface energy polyethylene anti-corrosion and anti-fouling special material comprises the following steps:

[0054] The above raw materials are added into a high-speed blender, mixed evenly, and then extruded and granulated by a twin-screw extruder at a temperature of 170-220°C to obtain a polyethylene masterbatch; the obtained polyethylene masterbatch is dried and ground by a low-temperature grinding process to obtain polyethylene powder, and then passed through a 100-mesh sieve to obtain the low-surface-energy polyethylene anti-corrosion and anti-fouling special material.

[0055] Example 5

[0056] A low-surface-energy polyethylene anticorrosion and antifouling special material comprises the following components in parts by weight: 40 parts of high-density polyethylene resin (melt index 0.9 g / 10 min), 60 parts of low-density polyethylene (melt index 16 g / 10 min), 10 parts of maleic anhydride grafted polyethylene, 0.3 parts of antioxidant 1010, 1 part of leveling agent, 3 parts of fluorinated graphene (the average powder diameter is 8 μm, F / C=1.35), and 4 parts of polytetrafluoroethylene micropowder (the average diameter is 15 μm).

[0057] The preparation of the above-mentioned low surface energy polyethylene anti-corrosion and anti-fouling special material comprises the following steps:

[0058] The above raw materials are added into a high-speed blender, mixed evenly, and then extruded and granulated by a twin-screw extruder at a temperature of 170-220°C to obtain a polyethylene masterbatch; the obtained polyethylene masterbatch is dried and ground by a low-temperature grinding process to obtain polyethylene powder, and then passed through a 100-mesh sieve to obtain the low-surface-energy polyethylene anti-corrosion and anti-fouling special material.

[0059] Comparative Example 1

[0060] Example 1 was repeated, except that graphite fluoride and polytetrafluoroethylene powder were not added to the formula.

[0061] Comparative Example 2

[0062] Example 1 was repeated, except that no polytetrafluoroethylene powder was added.

[0063] Comparative Example 3

[0064] Example 1 was repeated except that no graphite fluoride was added.

[0065] Comparative Example 4

[0066] The same as Example 2, except that the F / C ratio in the fluorinated graphite is 0.8, and other conditions remain unchanged, to prepare a polyethylene anti-corrosion and anti-fouling special material.

[0067] Comparative Example 5

[0068] The same as Example 2, except that the size of the fluorinated graphene powder is 30 μm, the size of the polytetrafluoroethylene powder is 30 μm, and the other conditions remain unchanged, to prepare a polyethylene anti-corrosion and anti-fouling special material.

[0069] Comparative Example 6

[0070] The same as Example 3, except that 11 parts of polytetrafluoroethylene powder (average diameter of 15 μm) are used, and other conditions remain unchanged, to prepare a polyethylene anti-corrosion and anti-fouling material.

[0071] The products obtained from the above embodiments and comparative examples were subjected to performance test experiments, and the test results are listed in the following Table 1.

[0072] The surface performance test method of the powder material is to coat a polyethylene anticorrosion coating with a thickness of 100±10μm on the metal substrate by the dipping method, and then dry it for 24 hours under natural conditions at room temperature to perform a water contact angle performance test. The results are shown in Table 1 below.

[0073] Table 1

[0074] CA(°) Example 1 131.7 Example 2 135.6 Example 3 130.1 Example 4 135.3 Example 5 129.4 Comparative Example 1 88.8 Comparative Example 2 106.3 Comparative Example 3 105.0 Comparative Example 4 109.1 Comparative Example 5 105.5 Comparative Example 6 98.7

[0075] Through Example 1 and Comparative Example 2, it can be concluded that the addition of polytetrafluoroethylene powder plays a role in further reducing the surface energy of the powder; combined with Example 2 and Comparative Example 4, it can be concluded that the F / C ratio in fluorinated graphite is large, which can greatly reduce the surface energy of the powder. When the F / C ratio is less than 1, the surface contact angle (with water) of the powder coating obtained is small. Combined with Example 3 and Comparative Example 5, it can be concluded that the powder particle size of fluorinated graphene and polytetrafluoroethylene powder plays a key role in reducing the surface energy. Combined with Example 1 and Comparative Examples 1-3, or Example 3 and Comparative Example 6, it can be concluded that when the mass ratio of fluorinated graphene and polytetrafluoroethylene powder needs to be controlled within a certain range, the two can work together synergistically to synergistically improve the contact angle between the powder coating and the water surface and reduce the surface energy. When the content of polytetrafluoroethylene powder is relatively high, a large amount of agglomeration occurs, and the effective synergistic effect with graphite fluoride is poor, so the surface energy of the coating cannot be reduced well.

[0076] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A low surface energy polyethylene anti-corrosion and anti-fouling special material, characterized in that: Contains the following components in parts by weight: 20-40 parts of high-density polyethylene, 40-60 parts of low-density polyethylene, 10-25 parts of compatibilizer, 0.1-0.3 parts of antioxidant, 0.5-2 parts of leveling agent, 0.5-5 parts of fluorocarbon functional material, and 0.5-5 parts of low surface energy auxiliary component.

2. The low surface energy polyethylene anti-corrosion and anti-fouling special material according to claim 1, characterized in that: The high-density polyethylene is a blow molding or cast grade high-density polyethylene resin with a melt index of 0.5-3 g / 10 min; and / or The low-density polyethylene has a melt index of 10-20 g / 10 min.

3. The low surface energy polyethylene anti-corrosion and anti-fouling special material according to claim 1 or 2, characterized in that: The mass ratio of the high-density polyethylene to the low-density polyethylene is 1:1-1:

3.

4. The low surface energy polyethylene anti-corrosion and anti-fouling special material according to claim 1, characterized in that: The compatibilizer is maleic anhydride grafted polyethylene.

5. The low surface energy polyethylene anti-corrosion and anti-fouling special material according to claim 1, characterized in that: The antioxidant is antioxidant 1010, antioxidant 168, antioxidant 1076 or antioxidant 2266; and / or The leveling agent is polyethyl acrylate and / or polybutyl acrylate.

6. The low surface energy polyethylene anti-corrosion and anti-fouling special material according to claim 1, characterized in that: The fluorocarbon functional material is fluorinated graphite or fluorinated graphene, wherein the mass ratio of F to C in the fluorocarbon functional material is greater than 1.

0.

7. The low surface energy polyethylene anti-corrosion and anti-fouling special material according to claim 1, characterized in that: The low surface energy auxiliary component is polytetrafluoroethylene powder, wherein the particle size of the polytetrafluoroethylene powder is ≤20 μm.

8. The low surface energy polyethylene anticorrosion and antifouling special material according to claim 1, 6 or 7, characterized in that: The mass ratio of the fluorocarbon functional material to the low surface energy auxiliary component is 10:1-0.2:

1.

9. The method for preparing the low surface energy polyethylene anticorrosion and antifouling special material according to any one of claims 1 to 8, characterized in that: The following steps are included: The raw material components are mixed evenly, extruded and granulated at a temperature of 170-220° C., and then ground to obtain a powdery material. After the powdery material is sieved, the low-surface-energy polyethylene anticorrosion and antifouling special material is obtained.

10. Use of the low surface energy polyethylene anti-corrosion and anti-fouling special material as described in any one of claims 1 to 8 as an anti-corrosion coating.

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