Fluorine-containing methacrylate polymer modified epoxy resin coating and preparation method thereof

Abstract

The invention discloses a fluorine-containing methacrylate polymer modified epoxy resin coating and a preparation method thereof. The preparation method comprises the following steps: continuously mixing different types of acrylate monomers in a beaker; adding an initiator azodiisobutyronitrile, and continuously and uniformly mixing; and carrying out heating reaction on the stirred mixture, the polymerization regulator and the solvent to obtain the fluorine-containing methacrylate polymer. Adding the fluorine-containing methacrylate polymer, the epoxy resin, the curing agent, the defoaming agent and the dispersing agent into the solvent, and uniformly mixing; the mixed solution is sprayed and cured at a high temperature, and the fluorine-containing methacrylate polymer modified epoxy resin coating is prepared. According to the coating, the surface wettability of the coating is improved while the corrosion resistance of the coating is guaranteed, and the coating is changed from hydrophilicity to hydrophobicity.

Description

Technical Field

[0001] The invention relates to a preparation method and application of a fluorine-containing methacrylate polymer and a modified epoxy resin coating, and belongs to the technical field of epoxy resin coatings. Background Art

[0002] Epoxy resin, a general term for polymers containing two or more epoxy groups in their molecules, currently holds the largest market share in the coatings industry. Epoxy resin coatings possess excellent properties, including abrasion resistance, insulation, and acid and alkali resistance, making them the most widely used resin in metal corrosion protection. However, epoxy resins still have numerous limitations, such as poor hydrophobicity, poor weather resistance, and reduced adhesion over time. These limitations necessitate modification to meet performance requirements during application. Therefore, finding suitable modification methods to enhance these properties of epoxy resins will facilitate their wider application.

[0003] Fluorinated methacrylate polymers can create highly hydrophobic coatings on substrate surfaces. Furthermore, as acrylic polymers, fluorinated methacrylate polymers can adjust some of their properties by introducing monomers containing functional groups. Therefore, using fluorinated methacrylate polymers as modified resins to modify epoxy resins can improve their hydrophobicity and adhesion to a certain extent. Furthermore, when functional monomers are introduced, fluorinated methacrylate polymers can further enhance the corrosion resistance of the epoxy resin itself. Summary of the Invention

[0004] In order to overcome the disadvantage of poor hydrophobicity of the prior art epoxy resin coating, the present invention aims to provide a fluorine-containing methacrylate polymer, an epoxy resin coating based on the polymer and a preparation method thereof.

[0005] In order to solve the above technical problems

[0006] In a first aspect, the present invention provides a fluorine-containing methacrylate polymer having the following general chemical structure:

[0007]

[0008] wherein R is hydrogen or methyl, R1 and R2 may be the same or different, R1 is selected from any group of C1 to C18 alkyl, R2 is selected from any group of C1 to C18 alkyl, and Rf is a group having a CH2CH2C(CF3)2CF2CF2CF3 structure;

[0009] m is an integer ranging from 50 to 70, n is an integer ranging from 40 to 60, a is an integer ranging from 10 to 20, b is an integer ranging from 0 to 10, and c is an integer ranging from 0 to 10.

[0010] In a second aspect, the present invention further provides a method for preparing the fluorinated methacrylate polymer according to the first aspect, comprising the following steps:

[0011] (1) Acrylate monomer After stirring in the container, the initiator is added and stirring is continued to obtain a preliminarily blended mixture I;

[0012] (2) In a nitrogen atmosphere, the mixture I, a polymerization regulator, and a solvent are added and heated to react to prepare a fluorine-containing methacrylate copolymer.

[0013] Furthermore, acrylic acid ester monomers Any one selected from methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, isooctyl methacrylate, lauryl methacrylate, octadecyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, isooctyl acrylate, lauryl acrylate, and octadecyl acrylate.

[0014] Furthermore, acrylic acid ester monomers Fluorinated acrylic monomer

[0015]

[0016] Furthermore, acrylic acid ester monomers Any one selected from glycidyl methacrylate and glycidyl acrylate.

[0017] Furthermore, acrylic acid ester monomers Any one selected from dimethylaminoethyl methacrylate and dimethylaminoethyl acrylate.

[0018] Furthermore, in step (1), the acrylic acid ester monomer The molar ratio is 6:4:1, acrylic acid ester monomer The molar ratio is 5:0 to 5:4, acrylic acid ester monomer The molar ratio is 5:0 to 5:4.

[0019] Furthermore, in step (1), the reaction temperature is 20-40° C., and the stirring time before and after the addition of the initiator is 10-30 min.

[0020] Furthermore, in step (1), the initiator is an organic peroxide, an inorganic peroxide or an azo compound, the organic peroxide is one or more of benzoyl peroxide and lauroyl peroxide, the inorganic peroxide is one or more of potassium persulfate and ammonium persulfate, the azo compound is one or more of azobisisobutyronitrile and azobisisoheptanenitrile, and the amount of the initiator added is 0.6% to 1% of the total mass of the monomers.

[0021] Furthermore, in step (2), the reaction temperature is 90-95° C. and the reaction time is 2-3 h.

[0022] Furthermore, in step (2), the polymerization regulator is selected from one of isopropyl mercaptan, tert-amyl mercaptan, and dodecyl mercaptan, and the added amount is 0.1% to 0.25% of the total mass of the monomers; the solvent is selected from any one of ethyl acetate, propyl acetate, and n-butyl acetate, and the mass of the solvent is 0.9 to 1.4 times the total mass of the monomers.

[0023] In a third aspect, the present invention provides a fluorine-containing methacrylate polymer-modified epoxy resin coating, which is obtained by mixing the fluorine-containing methacrylate copolymer described in the first aspect with an epoxy resin, a curing agent, a defoaming agent, a dispersant and a solvent.

[0024] Furthermore, the epoxy resin is an E-44 epoxy resin; and the weight ratio of the fluorinated methacrylate copolymer to the epoxy resin is 1:3.

[0025] Furthermore, the curing agent is selected from any one of ethylenediamine curing agent and polyamide curing agent, and the added amount is 15% to 50% of the mass of the epoxy resin.

[0026] Furthermore, the defoaming agent is BYK-141, and the addition amount is 0.5% of the total amount of the resin.

[0027] Furthermore, the dispersant is BYK-163, and the addition amount is 2% of the total amount of the resin.

[0028] Furthermore, the solvent is selected from any one of dichloromethane and dichloroethane, and the mass ratio of the solvent to the epoxy resin is 1:1.

[0029] In a fourth aspect, the present invention provides a fluorine-containing methacrylate polymer-modified epoxy resin coating, which is obtained by spraying and drying the coating described in the third aspect.

[0030] Furthermore, the temperature of the drying process is 40-60° C., and the drying time is 5-6 hours.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) Ordinary epoxy resin coatings have certain anti-corrosion capabilities, but their hydrophobicity is poor and they cannot adapt to the anti-corrosion conditions in humid environments. The fluorinated methacrylate-modified epoxy resin coating provided by the present invention improves the wetting properties of the coating surface while ensuring the anti-corrosion capability of the coating itself, changing it from hydrophilic to hydrophobic, making the epoxy resin coating have a wider range of applications.

[0033] (2) The fluorinated groups in the fluorinated methacrylate polymer have a branched short-chain structure. Studies have shown that the longer the fluorinated chain segment, the more difficult it is to degrade and bioaccumulate, and therefore the more harmful it is. The fluorinated groups in currently common fluorinated methacrylate polymers are long straight-chain fluorinated groups. In contrast, the fluorinated groups in the present invention have shorter fluorinated chain segments and excellent environmental performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The infrared spectra of the polymers prepared in Examples 1 to 4 of the present invention are as follows;

[0035] Figure 2 The water contact angle of each coating surface prepared in the comparative example and application example of the present invention;

[0036] Figure 3 These are electrochemical anti-corrosion test diagrams of the various coatings prepared in the comparative application examples and application examples of the present invention. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0038] If the specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer shall be followed. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased from the market. It is homemade and prepared according to patent (publication number CN119529620A).

[0039] Example 1

[0040] Synthesis of fluorinated methacrylate copolymer M, which has the following structural formula:

[0041]

[0042] The synthesis process includes the following steps: (1) Add 0.67g of methyl methacrylate (MMA), 0.71g of butyl methacrylate (BMA), and 0.60g of fluorinated methacrylate (FMA) into a flask and stir at room temperature for 10 minutes. Then add 0.014g of azobisisobutyronitrile (AIBN) as an initiator. Continue stirring at room temperature for 10 minutes. A methacrylate mixture is obtained. (2) In a 50ml Schlenk flask, under the protection of N2 atmosphere, add the methacrylate mixture, 1.92g of n-butyl acetate and 0.004g of dodecyl mercaptan. The reaction system is placed at 90℃ for 2h to obtain a fluorinated methacrylate copolymer M, and the infrared spectrum is as shown below. Figure 1 As stated.

[0043] Example 2

[0044] Synthesis of fluorinated methacrylate copolymer D, which has the following structural formula:

[0045]

[0046] The synthesis process includes the following steps: (1) Add 0.67g of methyl methacrylate (MMA), 0.71g of butyl methacrylate (BMA), 0.60g of fluorinated methacrylate (FMA), and 0.12g of dimethylaminoethyl methacrylate (DMAM) into a flask and stir at room temperature for 10 minutes. Then add 0.014g of azobisisobutyronitrile (AIBN) as an initiator. Continue stirring at room temperature for 10 minutes. A methacrylate mixture is obtained. (2) In a 50ml Schlenk flask, under the protection of N2 atmosphere, add the methacrylate mixture, 1.92g of n-butyl acetate and 0.004g of dodecyl mercaptan. The reaction system is placed at 90℃ for 2h to obtain a fluorinated methacrylate copolymer D, and the infrared spectrum is as shown below. Figure 1 As stated.

[0047] Example 3

[0048] Synthesis of fluorinated methacrylate copolymer G, which has the following structural formula:

[0049]

[0050] The synthesis process includes the following steps: (1) Add 0.67g of methyl methacrylate (MMA), 0.71g of butyl methacrylate (BMA), 0.60g of fluorinated methacrylate (FMA), and 0.12g of glycidyl methacrylate (GMA) into a flask and stir at room temperature for 10 minutes. Then add 0.014g of azobisisobutyronitrile (AIBN) as an initiator. Continue stirring at room temperature for 10 minutes. A methacrylate mixture is obtained. (2) In a 50ml Schlenk flask, under the protection of N2 atmosphere, add the methacrylate mixture, 1.92g of n-butyl acetate and 0.004g of dodecyl mercaptan. The reaction system is placed at 90℃ for 2h to obtain a fluorinated methacrylate copolymer G, the infrared spectrum of which is shown as follows: Figure 1 As stated.

[0051] Example 4

[0052] Synthesis of fluorinated methacrylate copolymer DG, which has the following structural formula:

[0053]

[0054] The synthesis process includes the following steps: (1) 0.67g methyl methacrylate (MMA), 0.71g butyl methacrylate (BMA), 0.60g fluorinated methacrylate (FMA), 0.12g glycidyl methacrylate (GMA), and 0.12g dimethylaminoethyl methacrylate (DMAM) are added to a flask and stirred at room temperature for 10 minutes. Then 0.014g azobisisobutyronitrile (AIBN) is added as an initiator. Continue stirring at room temperature for 10 minutes. A methacrylate mixture is obtained. (2) In a 50ml Schlenk flask, under the protection of N2 atmosphere, the methacrylate mixture, 1.92g n-butyl acetate and 0.004g dodecyl mercaptan are added. The reaction system is placed at 90℃ for 2h to obtain a fluorinated methacrylate copolymer DG, and the infrared spectrum is as shown below. Figure 1 As stated.

[0055] Comparative Application Examples

[0056] 1.5g of epoxy resin and 1.04g of polyamide curing agent were dissolved in dichloromethane to prepare an epoxy resin solution. This epoxy resin solution was then sprayed evenly onto the substrate surface at a distance of 15cm from the substrate using a 0.5mm spray gun at a pressure of 0.3 MPa. The sprayed substrate was then cured in an oven at 60°C for 6 hours to produce the epoxy resin coating used in the control group.

[0057] Application Examples

[0058] According to the ratio described in Table 1, the fluorinated methacrylate copolymer (Examples 1 to 4), curing agent, dispersant and defoaming agent were added to the epoxy resin solution and stirred at room temperature for 2 hours at 500 rpm to obtain the modified epoxy resin solution. The prepared modified epoxy resin solution was added to a spray gun with a diameter of 0.5 mm and sprayed evenly onto the surface of the substrate at a pressure of 0.3 MPa at a distance of 15 cm from the surface of the substrate. The sprayed substrate was placed in an oven at 60°C and cured for 6 hours to obtain a fluorinated methacrylate copolymer modified epoxy resin coating. According to the corresponding polymer names of Examples 1 to 4, the modified epoxy resin coatings were named M@E, D@E, G@E and DG@E, respectively.

[0059] Table 1

[0060]

[0061]

[0062] The coatings prepared in the above application examples and comparative application examples were subjected to hydrophobicity tests. The contact angles of the coatings with water were tested three times and the average value was taken. The test conditions were: liquid volume 3 μl, height 0.5 cm, magnification 7 times, and the results were as follows: Figure 2 As shown in Table 2 below;

[0063] Table 2

[0064]

[0065] When using contact angle as an indicator for evaluating hydrophobicity, the sample test results show that the water contact angle (WCA) value of pure epoxy resin E is only 76.7°. Based on the water contact angle data, this coating is a hydrophilic coating. However, after adding the fluorinated methacrylate copolymer, the water contact angles of M@E, D@E, G@E, and DG@E coatings are all greater than 90°. Judging from the water contact angle data, the coatings have become hydrophobic coatings. In addition, compared with the M@E coating without the functional monomer, the D@E, G@E, and DG@E coatings with the functional monomer added have improved hydrophobicity, and the water contact angles all exceed 100°, indicating relatively good hydrophobic performance. This is because the surfaces of the D@E, G@E, and DG@E coatings with the functional monomer added all have a dense structure and a certain degree of roughness. While the surface of the M@E coating also has some roughness, it has more pits and is less dense, making it easier for water droplets to penetrate the surface, resulting in a slightly lower hydrophobicity.

[0066] The corrosion resistance of each coating was tested using electrochemical impedance spectroscopy (EIS). A three-electrode system was used, with the sample being used as the working electrode, a carbon rod as the auxiliary electrode, and a saturated calomel electrode as the reference electrode. The back of the sample was sealed with polyimide tape, and the front of the sample was exposed to an area of 1 cm. 2 , the electrochemical medium uses 3.5wt% sodium chloride solution. The test results are as follows Figure 3 shown.

[0067] The Nyquist plots of the electrochemical impedance response of each coating show that all five coatings exhibit good corrosion resistance, with large capacitance ring diameters. Comparing the five coatings, the corrosion resistance of pure epoxy resin is relatively average. However, the capacitance ring diameter of M@E modified with a fluorinated methacrylate copolymer increases, correspondingly improving corrosion resistance. The capacitance ring diameters of D@E and G@E coatings incorporating a single functional monomer are further increased, further enhancing corrosion resistance. This is due to the denser surface structures of both coatings, which prevent salt intrusion and protect the substrate from corrosion. However, the capacitance ring diameter of DG@E coating, incorporating both functional monomers, decreases slightly compared to D@E and G@E, but remains larger than that of E coating, demonstrating superior corrosion resistance. These results demonstrate that the addition of a fluorinated methacrylate copolymer does not diminish the corrosion resistance of epoxy resins. In fact, with the addition of appropriate functional monomers, it can further enhance their corrosion resistance.

[0068] As can be seen from the above implementation process, the present invention prepared a fluorinated methacrylate polymer using methyl methacrylate, butyl methacrylate, fluorinated methacrylate, glycidyl methacrylate, and dimethylaminoethyl methacrylate. The prepared fluorinated methacrylate polymer was then used to modify an epoxy resin coating. The results showed that the modified epoxy resin coating prepared by the present invention had improved hydrophobicity and did not lose the inherent corrosion resistance of the epoxy resin, but rather further improved its corrosion resistance. In addition, the raw material cost of the present invention is low, achieving both economical and functional coexistence.

[0069] In addition to the above embodiments, the present invention may also have other implementations. Any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection required by the present invention.

Claims

1. A fluorine-containing methacrylate polymer, characterized in that It has the following chemical structure: wherein R is hydrogen or methyl, R1 and R2 may be the same or different, R1 is selected from any group of C1 to C18 alkyl, R2 is selected from any group of C1 to C18 alkyl, and Rf is a group having a CH2CH2C(CF3)2CF2CF2CF3 structure; m is an integer ranging from 50 to 70, n is an integer ranging from 40 to 60, a is an integer ranging from 10 to 20, b is an integer ranging from 0 to 10, and c is an integer ranging from 0 to 10.

2. A method for preparing a fluorine-containing methacrylate polymer according to claim 1, characterized in that: The specific steps include: (1) Acrylate monomer After stirring in the container, the initiator is added and stirring is continued to obtain a preliminarily blended mixture I; (2) In a nitrogen atmosphere, the mixture I, a polymerization regulator, and a solvent are added and heated to react to prepare a fluorine-containing methacrylate copolymer.

3. The method according to claim 2, wherein Acrylate monomers Any one selected from methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, isooctyl methacrylate, lauryl methacrylate, octadecyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, isooctyl acrylate, lauryl acrylate, and octadecyl acrylate.

4. The method according to claim 2, wherein Acrylate monomers Fluorinated acrylic monomer 5. The method according to claim 2, wherein Acrylate monomers Any one selected from glycidyl methacrylate and glycidyl acrylate.

6. The method according to claim 2, wherein Acrylate monomers Any one selected from dimethylaminoethyl methacrylate and dimethylaminoethyl acrylate.

7. The method according to claim 2, wherein In step (1), acrylate monomer The molar ratio is 6:4:1, acrylic acid ester monomer The molar ratio is 5:0 to 5:4, acrylic acid ester monomer The molar ratio is 5:0 to 5:

4.

8. A fluorine-containing methacrylate polymer-modified epoxy resin coating, which is obtained by mixing the fluorine-containing methacrylate copolymer according to claim 1 with an epoxy resin, a curing agent, a defoaming agent, a dispersant and a solvent.

9. A fluorine-containing methacrylate polymer modified epoxy resin coating, which is obtained by spraying and drying the coating according to claim 8.

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