Fluorine-containing acrylate, and preparation method and application thereof

Abstract

This invention discloses a fluorinated acrylate, characterized in that: the structure of the fluorinated acrylate is shown in Formula I, wherein n is an integer from 1 to 15, y is an integer from 10 to 100, R1 is H or F, R2 is H, Cl, or F, and R3 is H, CH3, CH2CH3, CH2CH2CH3, or CH(CH3)2. The fluorinated acrylate of this invention can be used as a photocurable material, resulting in cured products with excellent mechanical properties such as high adhesion and high hardness, as well as excellent properties such as high temperature resistance, corrosion resistance, and hydrophobic and oleophobic properties, making it applicable in coatings, adhesives, sealants, and ink printing.

Description

Technical Field

[0001] This invention relates to the field of polymer technology, and in particular to a fluorinated acrylate, its preparation method, and its application. Background Technology

[0002] Fluorine atoms possess strong electronegativity, low polarizability, and small atomic radii, endowing fluoropolymers with unique properties such as high-temperature resistance, corrosion resistance, and hydrophobic and oleophobic characteristics. Acrylic polymers, as the most widely used photocurable materials, offer advantages such as fast curing speed, high efficiency, and energy saving and environmental friendliness. Introducing fluorine into acrylate materials further enhances the polymer's high-temperature resistance and corrosion resistance while retaining the high efficiency and environmental friendliness of photocuring, making it a current research hotspot.

[0003] Patent CN103059706B uses acrylate, fluorinated acrylate, and hydroxy acrylate monomers as raw materials, copolymerizing them into hydroxy fluorinated acrylate under the action of an initiator. Further modification with multifunctional isocyanates converts the hydroxyl groups to isocyanate groups. Finally, a capping reaction is performed with a hydroxy acrylate functional monomer to obtain a photocurable fluorinated acrylate. The product obtained by this method has the advantages of high functionality, large molecular weight, and fast curing rate. However, the fluorine content in the raw monomers is low, and the fluorine content of the final product is only 5-20 wt%, which has limited improvement on the product's high-temperature resistance, corrosion resistance, and hydrophobic and oleophobic properties. Furthermore, fluorinated acrylate monomers and hydroxy acrylate monomers are difficult to obtain and expensive, making them unsuitable for industrial production.

[0004] Patent CN115403716B uses fluorinated polyether diols as raw materials to prepare photocurable fluorinated acrylates through isocyanate modification and hydroxyl acrylate end-capping. This synthesis method has the advantages of mild reaction conditions, no byproducts, and simple operation. However, it also has drawbacks, such as low functionality, the need to add multifunctional components to the subsequent curing formulation to improve the strength of the cured product, and the fact that the added multifunctional components are non-fluorinated, have poor compatibility with the product, and offer limited improvement in mechanical properties.

[0005] In summary, existing photocurable fluorinated acrylates suffer from problems such as low fluorine content and difficulty in obtaining raw materials, as well as low functionality, poor compatibility with additives, and insufficient mechanical properties of cured products. Therefore, researching fluorinated acrylates with multifunctionality, high fluorine content, and tunable molecular weight is of great significance for expanding the application of photocurable acrylate materials in high-performance coatings, adhesives, sealants, and ink printing. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a fluorinated acrylate that can be used as a photocurable material, resulting in cured products with excellent mechanical properties such as high adhesion and high hardness. It also possesses excellent impact resistance, corrosion resistance, and hydrophobic and oleophobic properties, making it applicable to fields such as coatings, adhesives, sealants, and ink printing.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A fluorinated acrylate, the structure of which is shown in Formula I:

[0009]

[0010] Where n is an integer from 1 to 15, y is an integer from 10 to 100, R1 is H or F, R2 is H, Cl or F, and R3 is H, CH3, CH2CH3, CH2CH2CH3 or CH(CH3)2.

[0011] Preferably, in Formula I, n is an integer from 4 to 8, and y is an integer from 20 to 60.

[0012] The fluorinated acrylate has a number average molecular weight of 1,000 to 12,000, preferably 2,000 to 6,000; a molecular weight distribution of 1.05 to 1.8; and a fluorine content of 39 to 71 wt%, preferably 45 to 65 wt%.

[0013] The present invention also provides a method for preparing the fluorinated acrylate, the method comprising the following steps:

[0014] S1. Fluorine-containing monomers are subjected to a RAFT reaction in the presence of a chain transfer agent, persulfate, and emulsifier to generate oligomer A, as shown in formula S1:

[0015]

[0016] Where R1 is H or F, R2 is H, Cl or F, X is Br or I, n is an integer from 1 to 15, and y is an integer from 10 to 100;

[0017] S2. Oligomer A undergoes an addition reaction with an enol monomer under the action of an azo catalyst to generate oligomer B, as shown in formula S2:

[0018]

[0019] Where R3 is H, CH3, CH2CH3, CH2CH2CH3 or CH(CH3)2;

[0020] S3. Oligomer B undergoes an alcoholysis reaction with a strong alkaline solution to generate oligomer C, as shown in equation S3:

[0021]

[0022] The strong alkaline solution is selected from at least one of sodium hydroxide solution, potassium hydroxide solution, or barium hydroxide solution;

[0023] S4. Oligomer C reacts with acryloyl chloride under the action of an organic base catalyst to produce the fluorinated acrylate product, as shown in formula S4:

[0024]

[0025] The molecular weight of the target product prepared by the preparation method of the present invention can be controlled and the molecular weight distribution is narrow, mainly by selecting different fluorine-containing monomers to control the proportion of fluorine in the target product.

[0026] Specifically, in step S1, the fluorinated monomer is selected from at least one of tetrafluoroethylene, trifluoroethylene, trifluorochloroethylene, or vinylidene fluoride; the chain transfer agent is I(CF2). n I or Br(CF2) n Br; the persulfate is selected from at least one of sodium persulfate, potassium persulfate, or ammonium persulfate; the emulsifier is selected from at least one of ammonium perfluorooctanoate, ammonium hexafluoropropylene oxide dimer carboxylate, or ammonium hexafluoropropylene oxide trimer carboxylate.

[0027] In step S3, the azo catalyst is selected from at least one of azobisisobutyronitrile, azobisisoheptanenitrile, or azoisobutyronitrile cyanoformamide; in step S4, the organic base catalyst is selected from at least one of triethylamine, tetramethylethylenediamine, or 4-dimethylaminopyridine.

[0028] More specifically, the preparation method includes the following steps:

[0029] S1. Chain transfer agent, persulfate, emulsifier, water and fluorinated monomer are added to the reactor respectively, vacuum is drawn and inert gas is replaced, the reaction temperature is 50-100℃, the reaction time is 6-24h, the resulting emulsion is demulsified, washed with water and dried to obtain oligomer A;

[0030] S2. Oligomer A, enol monomer, first organic solvent and azo catalyst are added to the reactor, vacuum is drawn and inert gas is replaced, the reaction temperature is 50-100℃, the reaction time is 6-24h, and the obtained product is distilled, washed and dried to obtain oligomer B.

[0031] S3. Mix oligomer B, strong alkaline solution and first organic solvent in a reactor, evacuate and replace with inert gas, react at a temperature of 20-95℃ for 6-24 hours, and obtain oligomer C by distillation, washing and drying of the product.

[0032] S4. The oligomer C, acryloyl chloride, organic base catalyst and second organic solvent are mixed in a reactor, vacuumed and replaced with inert gas, the reaction temperature is 10-70℃ and the reaction time is 6-48h. The product is distilled, washed and dried to obtain the fluorinated acrylate.

[0033] The first organic solvent is selected from at least one of aniline, dimethylformamide, and acetonitrile; the second organic solvent is selected from at least one of methyl isobutyl ketone, tetrahydrofuran, ethyl acetate, and chloroform.

[0034] Preferably, in step S1, the mass ratio of chain transfer agent, persulfate, emulsifier, water and fluorinated monomer is (3-20):1:1:100:30, the reaction temperature is 60-80℃, and the reaction time is 8-16h.

[0035] In step S2, the mass ratio of oligomer A, first organic solvent, catalyst and enol monomer is 10:100:(0.5~2):(1~10), preferably 10:100:(0.8~1.5):(2~6), the reaction temperature is 60~90℃, and the reaction time is 8~20h.

[0036] In step S3, the strong alkali solution is a strong alkali solution with a mass fraction of 10% to 80%, preferably 50% to 80%, and more preferably 60% to 75%. The mass ratio of oligomer B, strong alkali solution, and first organic solvent is 1:(2 to 10):(2 to 10), preferably 1:(4 to 6):(4 to 6), the reaction temperature is 50 to 90°C, and the reaction time is 8 to 16 hours.

[0037] In step S4, the mass ratio of oligomer C, the second organic solvent, acryloyl chloride and the catalyst is 10:100:(2-10):(0.2-2), preferably 10:100:(4-6):(0.7-1.5), the reaction temperature is 20-50℃, and the reaction time is 10-40h.

[0038] The present invention also provides an application of the fluorinated acrylate as a photocurable material.

[0039] The fluorinated acrylate of this invention has tetrafunctional active end groups and a relatively long main chain structure. Its apparent state is a fluid liquid or waxy substance. When used as a photocurable material, the tetrafunctionality, under the action of a photoinitiator, provides more crosslinking sites, eliminating the need for other multifunctional non-fluorinated crosslinking agents to crosslink and form a three-dimensional interwoven structure. This maintains the high fluorine content of the composition and improves the hardness of the cured product. The longer main chain structure further enhances the flexibility of the molecular chain, improving the adhesion of the cured product. Through the synergistic effect of the three-dimensional network structure and the flexible main chain, the fluorinated acrylate enables the cured product to possess excellent mechanical properties, including high adhesion and high hardness. Simultaneously, the high fluorine content of the fluorinated acrylate gives the cured product special properties such as impact resistance, corrosion resistance, and hydrophobic and oleophobic properties, making it applicable to coatings, adhesives, sealants, and ink printing.

[0040] The present invention also provides a fluorinated acrylate coating, wherein the fluorinated acrylate coating comprises the aforementioned fluorinated acrylate.

[0041] Specifically, the fluorinated acrylate coating comprises 60-90 wt% fluorinated acrylate, 5-40 wt% diluent, 1-5 wt% photoinitiator, 0.1-1 wt% defoamer, and 0.1-1 wt% leveling agent.

[0042] The diluent is selected from at least one of 1,6-hexanediol diacrylate, ethyl acetate, butyl acetate, acetone, butanone, ethylene glycol-butyl ether, and ethylene glycol-ethyl ether; the photoinitiator is selected from at least one of 1-hydroxycyclohexylphenyl ketone, ethyl 2,4,6-trimethylbenzoylphosphonate, or ethyl 4-dimethylaminobenzoate; the defoamer is selected from at least one of polydimethylsiloxane, BYK-141, or ethylene bis-stearamide; and the leveling agent is selected from at least one of diacetone alcohol, isophorone, or BYK-333.

[0043] The fluorinated acrylate coating has a water contact angle of 105–120 degrees, an adhesion grade of 0–2, a hardness of H–2H, and a neutral salt spray resistance of 600–1000 hours.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0045] 1. The fluorinated acrylate of the present invention has tetrafunctional active end groups and a long main chain structure. When used as a photocurable material in coatings, adhesives and sealants, it can ensure that the cured product has excellent mechanical properties such as high adhesion and high hardness, while also having special properties such as impact resistance, corrosion resistance and hydrophobicity and oleophobicity.

[0046] 2. The method for preparing fluorinated acrylates described in this invention uses fluorinated monomers as starting materials and proceeds through four steps: RAFT polymerization, enol monomer addition, halogen alcoholysis, and acryloyl chloride end-capping. This method features inexpensive and readily available fluorinated monomer raw materials, making it suitable for industrial production. Attached Figure Description

[0047] Figure 1 The image shows the NMR F-spectrum characterization of the fluorinated acrylate described in Example 1 of this invention, where -108.6 ppm, -109.8 ppm, -112.8 ppm, -121.7 ppm, and -122.8 ppm represent -CF2R. H Characteristic peaks for -CF₂CFCl-, -CF₂CF₂-, -CFClCFCl-, and -CF₂CFClCF₂-, with -CFClR at -118.8 ppm and -119.6 ppm. H Characteristic peak, R H It is CH(OCOCHCH2)CH2OCOCHCH2. Detailed Implementation

[0048] The present invention will be further described below with reference to specific embodiments, but the invention is not limited to these specific embodiments. Those skilled in the art should recognize that the present invention covers all alternatives, improvements, and equivalents that may be included within the scope of the claims.

[0049] In the following embodiments:

[0050] The trifluorochloroethylene (CTFE) was purchased from Sinochem Lantian Fluorine Materials Co., Ltd., CAS No. 79-38-9;

[0051] Trifluoroethylene (TrFE) was purchased from Sinochem Lantian Fluorine Materials Co., Ltd., CAS No. 359-11-5;

[0052] Vinylidene fluoride (VDF) was purchased from Sinochem Lantian Fluorine Materials Co., Ltd., CAS No. 75-38-7;

[0053] Tetrafluoroethylene (TFE) was purchased from Zhonghao Chenguang Research Institute, CAS number 116-14-3;

[0054] 1,4-Diiodoperfluorobutane was purchased from Tokyo Chemical Industry Co., Ltd., CAS No. 375-50-8;

[0055] Ammonium persulfate was purchased from Bailingwei, CAS number 7727-54-0;

[0056] Allyl alcohol was purchased from Bailingwei, CAS number 107-18-6;

[0057] Azobisisobutyronitrile was purchased from Bailingwei, CAS number 78-67-1;

[0058] Acryloyl chloride was purchased from Bailingwei, CAS number 814-68-6;

[0059] Hydroxyl-terminated perfluoropolyether, brand name -E10-H, purchased from SOLVAY;

[0060] Hexamethylene diisocyanate (HDI) was purchased from Bailingwei, CAS number 822-06-0;

[0061] BYK-141 was purchased from Shanghai Buding Chemical Co., Ltd.

[0062] BYK-333 was purchased from Shanghai Buding Chemical Co., Ltd.

[0063] 1,6-Hexanediol diacrylate (HDDA) was purchased from Hubei Xingyan New Material Technology Co., Ltd., CAS No. 13048-33-4;

[0064] 1-Hydroxycyclohexylphenyl ketone (Irgacure 184) was purchased from BASF AG, CAS No. 947-19-3.

[0065] The performance index testing method for fluorinated acrylates provided by this invention is as follows:

[0066] (1) The fluorine content was tested by energy dispersive X-ray spectroscopy;

[0067] (2) Molecular weight and molecular weight distribution were tested by gel permeation chromatography.

[0068] The performance index testing method for fluorinated acrylate coatings provided by this invention is as follows:

[0069] (1) Hardness test: The hardness of the coating film was tested by using a pencil hardness tester in accordance with the provisions of GB / T6739-1996.

[0070] (2) Water contact angle test: The contact angle between the cured film and deionized water was measured using a static drop contact angle meter in accordance with the GB / T30693-2014 standard;

[0071] (3) Adhesion test: The adhesion of the coating film was tested by cross-cutting. A 10×10 grid was formed by cross-cutting. 3M-610 pressure-sensitive tape was tightly adhered to the coating surface. Then the tape was quickly peeled off at a 90-degree angle, and the degree of damage to the grid edges was observed.

[0072] (4) Impact resistance test: Impact resistance test shall be performed using an impact tester in accordance with GB / T1732-1979(88);

[0073] (5) Neutral salt spray resistance test: The neutral salt spray resistance performance test shall be conducted in accordance with GB / T1771-2007.

[0074] The hardness of coatings is typically 5B to 3H, with higher hardness being better within this range. The water contact angle reflects the hydrophobic and oleophobic properties of the coating and is also related to its fluorine content. Fluorine-containing coatings typically have a water contact angle of 90 to 180 degrees, with higher angles indicating better hydrophobic and oleophobic properties. Adhesion is rated from 0 to 5, with lower ratings being better. The neutral salt spray test reflects the corrosion resistance of the coating.

[0075] Example 1

[0076] S1. Add 250 mL of deionized water, 7.5 g of 1,4-diiodoperfluorobutane, 1.0 g of ammonium persulfate, and 1.0 g of hexafluoropropylene oxide trimer ammonium carboxylate sequentially to a 500 mL autoclave. Then, evacuate the autoclave for 1 min, then purge it with nitrogen to 0.5 MPa, and evacuate it again to -0.1 MPa. Add 75 g (0.491 mol) of trifluorochloroethylene to the autoclave by weighing. At this point, the pressure in the autoclave rises to 0.4 MPa. Start stirring, slowly raise the temperature to 80 °C, and then keep the temperature constant for 12 h. After the reaction is complete, turn off the heating, cool the autoclave to room temperature, and remove the unreacted gaseous monomers to obtain a white emulsion. The emulsion can be treated by freezing or demulsifying with calcium chloride solution.

[0077] S2. Add 20g of oligomer A and 200g of DMF to a 500ml three-necked flask, and stir continuously at room temperature for 2 hours until oligomer A is completely dissolved. Vacuum the flask to remove air and add a nitrogen atmosphere for protection. Slowly heat to 70°C using an oil bath while stirring continuously. Divide 6g of allyl alcohol and 2g of azobisisobutyronitrile into 3 equal portions, and add one portion at the end of the heating process, 4 hours of reaction, and 8 hours of reaction, respectively. After 12 hours, stop the reaction, turn off the heating, cool to room temperature, and remove the solvent and unreacted allyl alcohol by vacuum distillation to obtain a viscous liquid. Wash the liquid multiple times with deionized water, then remove water and dry to obtain pure oligomer B.

[0078] S3. Add 20g of oligomer B, 100g of DMF and 100g of 60% sodium hydroxide solution to a 500ml three-necked flask. Stir continuously at room temperature for 2 hours to completely dissolve oligomer B. Remove the air from the flask under vacuum and add a nitrogen atmosphere for protection. Slowly heat to 80°C using an oil bath and stir continuously for 24 hours. After distillation, washing with deionized water multiple times and drying, obtain polyhydroxy fluorinated oligomer C.

[0079] S4. Add 20g of oligomer C and 200g of THF to a 500ml three-necked flask, and stir continuously at room temperature for 2 hours until oligomer C is completely dissolved; remove the air from the flask under vacuum and add a nitrogen atmosphere for protection, and slowly heat to 40°C using an oil bath while stirring continuously. Divide 10g of acryloyl chloride and 2g of triethylamine into 3 equal portions, and add one portion at the end of the heating process, 8 hours of reaction, and 16 hours of reaction, respectively; stop the reaction after 24 hours, turn off the heating, cool to room temperature, and remove the solvent and unreacted acryloyl chloride by vacuum distillation to obtain a viscous liquid. Wash the liquid multiple times with deionized water, and then dry it to obtain pure fluorinated acrylate product 1.

[0080] Testing revealed that the total amount of fluorinated acrylate product 1 was 18.6 grams, with a reaction yield of 62%. The fluorine content of fluorinated acrylate product 1 was 43 wt%, the number average molecular weight was 4000 g / mol, the molecular weight distribution was 1.41, and the apparent state was liquid.

[0081] Example 2

[0082] The operation of Example 2 is the same as that of Example 1, except that 31.4g (0.491mol) of vinylidene fluoride is used instead of 75g (0.491mol) of trifluorochloroethylene, and other operations remain unchanged, to obtain pure fluorinated acrylate product 2.

[0083] Testing revealed that the total amount of fluorinated acrylate product 2 was 20.4 grams, with a reaction yield of 68%. The fluorine content of fluorinated acrylate product 2 was 51 wt%, the number average molecular weight was 2800 g / mol, the molecular weight distribution was 1.31, and the apparent state was liquid.

[0084] Example 3

[0085] The operation of Example 3 is the same as that of Example 1, except that 40.3g (0.491mol) of trifluoroethylene is used instead of 75g (0.491mol) of trifluorochloroethylene, and other operations remain unchanged, to obtain pure fluorinated acrylate product 3.

[0086] Testing revealed that the total amount of fluorinated acrylate product 3 was 19.8 grams, with a reaction yield of 66%. The fluorine content of fluorinated acrylate product 3 was 61 wt%, the number average molecular weight was 3200 g / mol, the molecular weight distribution was 1.29, and the apparent state was liquid.

[0087] Example 4

[0088] The operation of Example 4 is the same as that of Example 1, except that 49.1g (0.491mol) of tetrafluoroethylene is used instead of 75g (0.491mol) of trifluorochloroethylene, and other operations remain unchanged, to obtain pure fluorinated acrylate product 4.

[0089] Tests showed that 19.5 grams of fluorinated acrylate product 4 were produced, with a reaction yield of 65%. The fluorine content of fluorinated acrylate product 4 was 71 wt%, the number average molecular weight was 4200 g / mol, the molecular weight distribution was 1.39, and the apparent state was liquid.

[0090] Example 5

[0091] The operation of Example 5 is the same as that of Example 1, except that 2.5g of 1,4-diiodoperfluorobutane is added, and other operations remain unchanged, to obtain pure fluorinated acrylate product 5.

[0092] Tests showed that 17.1 grams of fluorinated acrylate product 5 were produced, with a reaction yield of 57%. The fluorine content of fluorinated acrylate product 5 was 45%, the number average molecular weight was 12000 g / mol, the molecular weight distribution was 1.8, and the appearance was waxy.

[0093] Example 6

[0094] The operation of Example 6 is the same as that of Example 1, except that 10g of 1,4-diiodoperfluorobutane is added, and other operations remain unchanged, to obtain pure fluorinated acrylate product 6.

[0095] Testing revealed that 19.5 grams of fluorinated acrylate product 6 were produced, with a reaction yield of 65%. The fluorine content of fluorinated acrylate product 6 was 42 wt%, the number average molecular weight was 3200 g / mol, the molecular weight distribution was 1.26, and the apparent state was liquid.

[0096] Example 7

[0097] The operation of Example 7 is the same as that of Example 1, except that 12.5g of 1,4-diiodoperfluorobutane is added, and other operations remain unchanged, to obtain pure fluorinated acrylate product 7.

[0098] Tests showed that the total amount of fluorinated acrylate product 7 was 21.3 grams, with a reaction yield of 71%. The fluorine content of fluorinated acrylate product 7 was 41 wt%, the number average molecular weight was 2400 g / mol, the molecular weight distribution was 1.18, and the apparent state was liquid.

[0099] Example 8

[0100] The operation of Example 8 is the same as that of Example 1, except that 25g of 1,4-diiodoperfluorobutane is added, and other operations remain unchanged, to obtain pure fluorinated acrylate product 8.

[0101] Testing revealed that 21.9 grams of fluorinated acrylate product 8 were produced, with a reaction yield of 73%. The fluorine content of fluorinated acrylate product 8 was 39 wt%, the number average molecular weight was 1000 g / mol, the molecular weight distribution was 1.05, and the apparent state was liquid.

[0102] Application Example 1

[0103] A fluorinated acrylate coating comprises the following components:

[0104]

[0105] Place the above components in a beaker and stir for 10 minutes to mix them evenly, thus obtaining fluorinated acrylate coating 1.

[0106] The fluorinated acrylate coating 1 is dropped onto a sandblasted steel plate using a dropper and then applied by rotation on a spin coater. The spin speed 1 is 600 r / min, with an acceleration time of 5 s and a uniform speed time of 15 s. The spin speed 2 is 2000 r / min, with an acceleration time of 5 s and a uniform speed time of 45 s. The UV curing lamp has a power of 1000 W and a curing time of 45 s, with a 15 s interval between each 15 s interval.

[0107] The hardness was tested to be 2H and the water contact angle was 105.6 degrees. The adhesion of the coating was tested using the cross-cut adhesion test. Small pieces peeled off at the intersection of the cuts. The actual damage in the cross-cut area did not exceed 5%, and the adhesion was rated as 0. The impact resistance test showed that there were no cracks on the coating surface. The coating did not blister, peel off, or rust under a 700-hour neutral salt spray test.

[0108] Application Example 2

[0109] The operation of Application Example 2 is the same as that of Application Example 1, except that 70 parts of the fluorinated acrylate (Mn=4200) prepared in Example 4 are used, and other operations remain unchanged to obtain the fluorinated acrylate coating 2.

[0110] After applying and curing the fluorinated acrylate coating 2 using the same method as in Application Example 1, the hardness was 2H and the water contact angle was 110.3 degrees. The adhesion of the coating was tested using the cross-cut adhesion test, and the edges were completely smooth with no peeling at the edges of the grids, indicating an adhesion level of 1. The impact resistance test showed no cracks on the coating surface. Under a 1000-hour neutral salt spray test, the coating did not bubble, peel, or rust.

[0111] Application Example 3

[0112] The operation of Application Example 3 is the same as that of Application Example 1, except that 70 parts of the fluorinated acrylate (Mn=2400) prepared in Example 7 are used, and other operations remain unchanged to obtain the fluorinated acrylate coating 2.

[0113] After applying and curing the fluorinated acrylate coating 2 using the same method as in Application Example 1, the hardness was 2H and the water contact angle was 104.3 degrees. The adhesion of the coating was tested using the cross-cut adhesion test, and the edges were completely smooth with no peeling at the edges of the grids, indicating an adhesion level of 1. The impact resistance test showed no cracks on the coating surface. Under a 600-hour neutral salt spray test, the coating did not bubble, peel, or rust.

[0114] Comparative Example 1

[0115] The operation of Comparative Example 1 is the same as that of Application Example 1, except that 70 parts of difunctional fluorinated acrylate (Mn = 4200) are used, and other operations remain unchanged to obtain the fluorinated acrylate coating D1.

[0116] After applying and curing the fluorinated acrylate coating D1 using the same method as in Application Example 1, the hardness was measured to be F and the water contact angle to be 90.6 degrees. The adhesion of the coating was tested using the cross-cut adhesion test, and the area that was peeled off was approximately 19%, with an adhesion rating of 2. The impact resistance test showed no cracks on the coating surface. Under a 400-hour neutral salt spray test, the coating did not bubble, peel off, or rust.

[0117] Comparative Example 2

[0118] The operation of Comparative Example 2 is the same as that of Application Example 1, except that 70 parts of tetrafunctional fluorinated acrylate (Mn = 900) are used, and other operations remain unchanged to obtain the fluorinated acrylate coating D2.

[0119] After applying and curing the fluorinated acrylate coating D2 using the same method as in Application Example 1, the hardness was 2H and the water contact angle was 92.1 degrees. The adhesion of the coating was tested using the cross-cut adhesion test, and the area that was peeled off was about 56%, with an adhesion level of 4. The impact resistance test showed no cracks on the coating surface. Under a 500-hour neutral salt spray test, the coating did not blister, peel off, or rust.

[0120] The fluorinated acrylate described in this invention has tetrafunctional active end groups and a long main chain structure. When used as a photocurable material in coatings, it can ensure that the cured coating has excellent mechanical properties such as high adhesion and high hardness, while also having special properties such as impact resistance, corrosion resistance and hydrophobicity and oleophobicity.

Claims

1. A fluorinated acrylate, characterized in that: The structure of the fluorinated acrylate is shown in Formula I: Where n is an integer from 1 to 15, y is an integer from 10 to 100, R1 is H or F, R2 is H, Cl or F, and R3 is H, CH3, CH2CH3, CH2CH2CH3 or CH(CH3)2.

2. The fluorinated acrylate according to claim 1, characterized in that: In Equation I, n is an integer from 4 to 8, and y is an integer from 20 to 50.

3. The fluorinated acrylate according to claim 1, characterized in that: The fluorinated acrylate has a number average molecular weight of 1,000 to 12,000, a molecular weight distribution of 1.05 to 1.8, and a fluorine content of 39 to 71 wt%.

4. A method for preparing a fluorinated acrylate according to any one of claims 1 to 3, characterized in that: The preparation method includes the following steps: S1. Fluorine-containing monomers are subjected to a RAFT reaction in the presence of a chain transfer agent, persulfate, and emulsifier to generate oligomer A, as shown in formula S1: Where R1 is H or F, R2 is H, Cl or F, X is Br or I, n is an integer from 1 to 15, and y is an integer from 10 to 100; S2. Oligomer A undergoes an addition reaction with an enol monomer under the action of an azo catalyst to generate oligomer B, as shown in formula S2: Where R3 is H, CH3, CH2CH3, CH2CH2CH3 or CH(CH3)2; S3. Oligomer B undergoes an alcoholysis reaction with a strong alkaline solution to generate oligomer C, as shown in equation S3: The strong alkaline solution is selected from at least one of sodium hydroxide solution, potassium hydroxide solution, or barium hydroxide solution; S4. Oligomer C reacts with acryloyl chloride under the action of an organic base catalyst to produce the fluorinated acrylate product, as shown in formula S4:

5. The method for preparing fluorinated acrylate according to claim 4, characterized in that: In step S1, the chain transfer agent is I(CF2). n I or Br(CF2) n Br; the fluorinated monomer is selected from at least one of tetrafluoroethylene, trifluoroethylene, trifluorochloroethylene or vinylidene fluoride; the persulfate is selected from at least one of sodium persulfate, potassium persulfate or ammonium persulfate; the emulsifier is selected from at least one of ammonium perfluorooctanoate, ammonium hexafluoropropylene oxide dimer carboxylate or ammonium hexafluoropropylene oxide trimer carboxylate.

6. The method for preparing fluorinated acrylate according to claim 4, characterized in that: In step S3, the azo catalyst is selected from at least one of azobisisobutyronitrile, azobisisoheptanenitrile, or azoisobutyronitrile cyanoformamide; in step S4, the organic base catalyst is selected from at least one of triethylamine, tetramethylethylenediamine, or 4-dimethylaminopyridine.

7. The method for preparing fluorinated acrylate according to claim 4, characterized in that: The preparation method includes the following steps: S1. Chain transfer agent, persulfate, emulsifier, water and fluorinated monomer are added to the reactor respectively, vacuum is drawn and inert gas is replaced, the reaction temperature is 50-100℃, the reaction time is 6-24h, the resulting emulsion is demulsified, washed with water and dried to obtain oligomer A; S2. Oligomer A, enol monomer, first organic solvent and azo catalyst are added to the reactor, vacuum is drawn and inert gas is replaced, the reaction temperature is 50-100℃, the reaction time is 6-24h, and the obtained product is distilled, washed and dried to obtain oligomer B. S3. Mix oligomer B, strong alkaline solution and first organic solvent in a reactor, evacuate and replace with inert gas, react at a temperature of 20-95℃ for 6-24 hours, and obtain oligomer C by distillation, washing and drying of the product. S4. The oligomer C, acryloyl chloride, organic base catalyst and second organic solvent are mixed in a reactor, vacuumed and replaced with inert gas, the reaction temperature is 10-70℃ and the reaction time is 6-48h. The product is distilled, washed and dried to obtain the fluorinated acrylate. The first organic solvent is selected from at least one of aniline, dimethylformamide, and acetonitrile; the second organic solvent is selected from at least one of methyl isobutyl ketone, tetrahydrofuran, ethyl acetate, and chloroform.

8. The use of the fluorinated acrylate according to any one of claims 1 to 3 as a photocurable material.

9. A fluorinated acrylate coating, characterized in that: The fluorinated acrylate coating comprises the fluorinated acrylate as described in any one of claims 1 to 3.

10. The fluorinated acrylate coating according to claim 9, characterized in that: The fluorinated acrylate coating comprises 60-90 wt% fluorinated acrylate, 5-40 wt% diluent, 1-5 wt% photoinitiator, 0.1-1 wt% defoamer and 0.1-1 wt% leveling agent.

11. The fluorinated acrylate coating according to claim 9, characterized in that: The water contact angle is 105-120 degrees, the adhesion is 0-2, the hardness is H-2H, and the resistance to neutral salt spray is 600-1000h.

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