Zwitterionic hydrophilic coating and its preparation method and application

Abstract

The application provides a zwitterionic hydrophilic coating, comprising a primer and a topcoat, the primer is prepared from raw materials including a benzophenone reactive ultraviolet absorber, a first solvent; the group of the benzophenone reactive ultraviolet absorber comprises a benzophenone group and two carbon-carbon double bonds; the topcoat is prepared from raw materials including a zwitterionic monomer with a double bond, an initiator, a second solvent. The zwitterionic hydrophilic coating of the application adopts a matched paint of the primer and the topcoat, the coating prepared according to the formula has excellent hydrophilicity, and has strong adhesion to the substrate and is stable and not easy to fall off. The zwitterionic hydrophilic coating is prepared by using an ultraviolet curing process, without the need of surface pre-activation treatment such as plasma activation, acid etching, silanization and the like on the substrate, and without the need of harsh preparation conditions such as oxygen removal, high temperature and the like, the preparation process is simple and easy to operate, and the practical application requirements can be met.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to an amphoteric hydrophilic coating, its preparation method, and its application. Background Technology

[0002] The surface of materials modified with hydrophilic compounds can bind a large number of water molecules, forming a hydration layer that can effectively inhibit the adsorption of biomolecules. Therefore, modifying the surface of materials with a polymer hydrophilic coating is a simple and effective method that can solve biocontamination without significantly altering the material's inherent properties. However, the excellent hydrophilicity and solubility of hydrophilic polymers in water make it difficult to fix them onto the material surface. Currently, there are two main methods for preparing polymer hydrophilic coatings: the first is to use redox-initiated in-situ grafting to modify the material surface. This method produces coatings with high stability, but the preparation conditions are harsh, making it unsuitable for large-scale industrial production, and its applicability is narrow and costly. The second method is to directly coat the surface of medical devices with hydrophilic polymers using physical adsorption, biomimetic bonding, and other methods. Commonly used hydrophilic polymers include nonionic hydrophilic polymers such as polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), polyvinyl alcohol, and polysaccharides, as well as zwitterionic polymers. This coating preparation method is relatively simple and has a wide range of applications, but it has problems such as poor coating adhesion and easy coating peeling.

[0003] Therefore, to address the above problems, developing a surface hydrophilic coating that is both universally applicable and possesses excellent hydrophilic properties and long-term stability, while also having a simple preparation process to meet practical application requirements, is the key technology and challenge in the research and development of hydrophilic coatings. Summary of the Invention

[0004] To overcome the problems existing in the prior art, one objective of this invention is to provide an amphoteric hydrophilic coating. A second objective is to provide an amphoteric hydrophilic coating layer. A third objective is to provide a method for preparing the aforementioned amphoteric hydrophilic coating layer. The amphoteric hydrophilic coating layer of this invention is prepared using a double-layer coating method. The coating prepared according to the described formula exhibits good hydrophilicity, strong adhesion to the substrate, stability, and is not easily detached, making it suitable for coating almost all polymeric materials.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A first aspect of the present invention provides an amphoteric hydrophilic coating comprising a primer and a topcoat, wherein the primer is prepared from raw materials comprising: a benzophenone-based reactive ultraviolet absorber and a first solvent; wherein the benzophenone-based reactive ultraviolet absorber comprises a benzophenone group and two carbon-carbon double bonds; and the topcoat is prepared from raw materials comprising: an amphoteric monomer with double bonds, an initiator, and a second solvent.

[0007] Preferably, the primer is made from raw materials comprising the following weight percentages: 2-20% benzophenone-based reactive ultraviolet absorber and a first solvent.

[0008] More preferably, the primer is made from the following raw materials in weight percentages: 2-20% benzophenone-based reactive ultraviolet absorber and 80-98% first solvent.

[0009] More preferably, the primer is made from the following raw materials by weight percentage: 5-15% benzophenone-based reactive ultraviolet absorber and 85-95% first solvent.

[0010] Preferably, the topcoat is made from raw materials comprising the following weight percentages: 1-10% zwitterionic monomer with double bonds, 0.02-0.2% initiator, and a second solvent.

[0011] More preferably, the topcoat is made from the following raw materials in weight percentage: 1-10% zwitterionic monomer with double bonds, 0.02-0.2% initiator, and 89.8-98.98% second solvent.

[0012] More preferably, the topcoat is made from the following raw materials in weight percentage: 1-5% zwitterionic monomer with double bonds, 0.02-0.2% initiator, and 94.8-98.98% second solvent.

[0013] Preferably, the benzophenone-based reactive ultraviolet absorber is prepared by a method comprising the following steps: mixing dihydroxybenzophenone and glycidyl methacrylate, and reacting them to obtain the benzophenone-based reactive ultraviolet absorber.

[0014] More preferably, the specific steps of the reaction are: reacting at 50-100℃ for 4-24 hours.

[0015] More preferably, the molar ratio of the dihydroxybenzophenone and glycidyl methacrylate is 1:2.

[0016] More preferably, the dihydroxybenzophenone is 4,4'-dihydroxybenzophenone.

[0017] Preferably, the zwitterionic monomer with double bonds is selected from one or more of sulfonate betaine type monomers, carboxylate betaine type monomers, phosphate betaine type monomers, and serine methacrylate and ornithine methacrylamide.

[0018] More preferably, the zwitterionic monomer with a double bond is methacryloylethyl sulfonate betaine, methacryloylethyl carboxybetaine, or methacryloylethyl phosphocholine.

[0019] Preferably, the first solvent includes one or more of methanol, ethanol, isopropanol, acetone, ethyl acetate, dichloromethane, and nitrile.

[0020] Preferably, the second solvent includes one or more of water, PBS, and physiological saline.

[0021] Preferably, the initiator includes one or more of the following: 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, phenyl-2,4,6-trimethylbenzoylphosphine lithium, 2,2-dimethoxyphenyl ethyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone, and 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone.

[0022] A second aspect of the present invention provides an amphoteric hydrophilic coating comprising a base coat and a top coat, wherein the base coat is prepared from the primer in the amphoteric hydrophilic coating of the first aspect; and the top coat is prepared from the topcoat in the amphoteric hydrophilic coating of the first aspect.

[0023] A third aspect of the present invention provides a method for preparing the zwitterionic hydrophilic coating described in the second aspect, comprising the following steps:

[0024] 1) A primer is prepared by dissolving a benzophenone-based reactive ultraviolet absorber in a first solvent. The primer is then applied to the surface of a substrate and subjected to ultraviolet light irradiation to obtain the primer.

[0025] 2) Dissolve the zwitterionic monomer with double bonds and the initiator in a second solvent to prepare a topcoat. After coating the topcoat on the surface of the primer, irradiate it with ultraviolet light to obtain the topcoat, thus obtaining a zwitterionic hydrophilic coating.

[0026] Preferably, in step 1), the duration of ultraviolet light irradiation is 30s-5min.

[0027] Preferably, in step 2), the duration of ultraviolet light irradiation is 10 min to 40 min.

[0028] Preferably, the coating step is specifically brushing or dipping.

[0029] Preferably, the substrate is a hydrocarbon-based polymer, including one of polyolefins, cellulose, polymethyl methacrylate, polystyrene, polyethersulfone, polyamide, polyurethane, polyacrylic acid, polyimide, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene fluoride, and polydimethylsiloxane.

[0030] The beneficial effects of this invention are:

[0031] This invention provides an amphoteric hydrophilic coating comprising a primer and a topcoat. The coating prepared according to the formula has good hydrophilicity, strong adhesion to the substrate, and is stable and not easily peeled off.

[0032] Specifically, it includes the following beneficial effects:

[0033] (1) This invention provides an amphoteric hydrophilic coating and its preparation method. By constructing a two-layer (bottom layer and top layer) coating system, a hydrophilic coating that is firmly bonded to the substrate is formed on the substrate surface. The primer serves as an intermediate connecting layer, providing cross-linking points for bonding with the top layer. The amphoteric monomers in the top layer solution can undergo chemical cross-linking with the bottom layer through simple ultraviolet light irradiation, thus connecting the top layer and the bottom layer through covalent bonds. On the other hand, the benzophenone structure in the bottom layer can easily form covalent bonds with the substrate, providing good substrate adhesion and coating stability. In addition, the amphoteric components in the top layer have excellent hydrophilicity, and the water contact angle of the amphoteric hydrophilic coating on the substrate surface is less than 30°, more preferably less than 10°.

[0034] (2) This invention uses ultraviolet light curing to prepare zwitterionic hydrophilic coatings. It eliminates the need for surface pre-activation treatments such as plasma activation, acid etching, and silanization of the substrate, and also avoids stringent preparation conditions such as deoxygenation and high temperatures. The preparation process is simple, easy to operate, and meets practical application requirements.

[0035] (3) The zwitterionic hydrophilic coating and its preparation method provided by the present invention are universal and the coating can be applied to the hydrophilic treatment of most polymer substrate surfaces. Attached Figure Description

[0036] Figure 1 The benzophenone-based reactive ultraviolet absorber in Example 1 1 H NMR spectrum;

[0037] Figure 2 Water contact angles of coatings prepared for PMMA substrates, Comparative Examples 1 and 2, and Example 1;

[0038] Figure 3 The water contact angle values ​​of the PMMA substrate, the coatings prepared in Comparative Examples 1 and 2 and Example 1, and the coating prepared in Example 1 after being soaked in water;

[0039] Figure 4 The water contact angle of the coating prepared in Example 2 and the water contact angle of the coating prepared in Example 2 after being soaked in water and ethanol in sequence. Detailed Implementation

[0040] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials used in the following embodiments can be obtained from conventional commercial channels or prepared and isolated through simple synthesis; unless otherwise specified, the processes employed are conventional processes in the art.

[0041] Example 1

[0042] 1. Preparation of primer solution:

[0043] 1.1 Preparation of benzophenone-based reactive ultraviolet absorber: 4,4'-dihydroxybenzophenone and glycidyl methacrylate were mixed in a flask at a molar ratio of 1:2 and reacted at 80°C for 5 hours. After purification, the benzophenone-based reactive ultraviolet absorber was obtained, and its structural formula is as follows:

[0044]

[0045] product 1 H NMR spectrum as shown Figure 1 As shown, 6.16 ppm and 5.62 ppm are characteristic peaks of carbon-carbon double bonds. According to the characteristic peak area analysis, benzophenone-based reactive ultraviolet absorbers contain two carbon-carbon double bonds.

[0046] 1.2 Preparation of primer solution: Prepare a 10wt% benzophenone-based reactive ultraviolet absorber solution with ethanol, and stir to dissolve at room temperature to obtain the primer solution;

[0047] 2. Preparation of topcoat solution: Prepare a 2wt% methacryloyl ethyl sulfonate betaine solution with water, add 0.02wt% initiator LAP, mix well to obtain the topcoat solution;

[0048] 3. Preparation of zwitterionic hydrophilic coating:

[0049] 3.1. Take a piece of material that is 1×1cm in size. 2 The PMMA substrate is cleaned and dried; the PMMA substrate is immersed in a primer solution, then removed and irradiated with 365nm ultraviolet light for 5 minutes; the primer solution forms a base coating on the surface of the substrate.

[0050] 3.2. Immerse the PMMA substrate coated with the primer in the topcoat solution, remove the substrate, and irradiate it with ultraviolet light at a wavelength of 365nm for 30 minutes to form a topcoat. Rinse the substrate surface with water several times to remove excess topcoat solution, and after drying, form an amphoteric hydrophilic coating including the primer and topcoat on the substrate surface.

[0051] Example 2

[0052] 1. Prepare the primer solution as described in Example 1;

[0053] 2. Preparation of topcoat solution: Prepare a 5wt% methacryloyl ethyl sulfonate betaine solution with water, add 0.02wt% initiator LAP, mix well to obtain the topcoat solution;

[0054] 3. Preparation of zwitterionic hydrophilic coating:

[0055] 3.1. Take a piece of material that is 1×1cm in size. 2 The PMMA substrate is cleaned and dried; the PMMA substrate is immersed in a primer solution, then removed and irradiated with 365nm ultraviolet light for 5 minutes; the primer solution forms a base coating on the surface of the substrate.

[0056] 3.2. Immerse the PMMA substrate coated with the primer in the topcoat solution, remove the substrate, and irradiate it with ultraviolet light at a wavelength of 365nm for 20 minutes to form a topcoat. Rinse the substrate surface with water several times to remove excess topcoat solution, and after drying, form an amphoteric hydrophilic coating including the primer and topcoat on the substrate surface.

[0057] Comparative Example 1

[0058] 1. Prepare the primer solution as described in Example 1;

[0059] 2. Preparation of coating (primer only): Prepare a 1×1cm... 2 The PMMA substrate is cleaned and dried; the PMMA substrate is immersed in a primer solution, then removed and irradiated with 365nm ultraviolet light for 5 minutes, forming a base coating on the substrate surface; it is then rinsed with water multiple times and dried.

[0060] Comparative Example 2

[0061] 1. Prepare the topcoat solution as described in Example 1;

[0062] 2. Preparation of coating (topcoat only): Prepare a 1×1cm... 2 The PMMA substrate is cleaned and dried; the PMMA substrate is immersed in the topcoat solution, the substrate is removed, and irradiated with 365nm ultraviolet light for 20 minutes, and the topcoat solution forms a topcoat on the surface of the substrate; the substrate is rinsed with water several times to remove excess topcoat solution, and then dried.

[0063] Experimental example:

[0064] The coatings of Examples 1-2 and Comparative Examples 1-2 were subjected to performance tests, and the specific process was as follows:

[0065] 1. Contact Angle Test: The water contact angle of the PMMA substrate surface coating was tested using a DSA25 contact angle meter. The test was conducted on the side of the substrate in contact with air. For the static water contact angle measurement, the droplet volume was 2 μL, and the temperature was 25°C. The contact angle value was measured 10 seconds after the water droplet contacted the surface, and the average value was taken from 5 points. Example 1 was then immersed in water for 2 days, and the contact angle was measured again. The test results are as follows: Figure 2-3 As shown. Figure 2 Water contact angles of coatings prepared for PMMA substrates, Comparative Examples 1 and 2, and Example 1; Figure 3 The water contact angle values ​​for the PMMA substrate, the coatings prepared in Comparative Examples 1 and 2, and Example 1, and the coating prepared in Example 1 after soaking in water for 2 days; the contact angle of Example 2 was measured again after soaking in water and ethanol for 2 days each, and the test results are as follows. Figure 4 As shown. Figure 4 The water contact angle of the coating prepared in Example 2 and the water contact angle of the coating prepared in Example 2 after being soaked in water and ethanol for 2 days each.

[0066] Depend on Figure 2-4 It can be seen that after the zwitterionic hydrophilic coating modifies the surface of the polymer substrate, compared with comparative examples 1-2, it can effectively improve the wetting ability of the substrate surface. The water contact angle of the zwitterionic hydrophilic coating on the substrate surface is less than 30°. Furthermore, the higher the content of zwitterions in the topcoat, the smaller the contact angle and the better the wetting performance. The water contact angle of the zwitterionic hydrophilic coating can be less than 10°.

[0067] After immersing the coating of Example 1 in water for 2 days, and immersing the coating of Example 2 in water and ethanol for 2 days each, the benzophenone structure in the bottom layer easily forms covalent bonds with the substrate, providing good substrate adhesion and coating stability, and the contact angle does not change much.

[0068] In summary, the zwitterionic hydrophilic coating of the present invention adopts a two-layer structure of primer and topcoat. The coating prepared according to the formula has good hydrophilicity, strong adhesion to the substrate, and is stable and not easy to fall off.

[0069] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A zwitterionic hydrophilic coating, characterized in that, It includes a base coat and a top coat, wherein the base coat is made of a primer; and the top coat is made of a top coat. The primer is made from the following raw materials: benzophenone-based reactive ultraviolet absorber and a first solvent; the functional groups of the benzophenone-based reactive ultraviolet absorber include benzophenone groups and two carbon-carbon double bonds; The structural formula of the benzophenone-based reactive ultraviolet absorber is shown in Formula A: Formula A; The topcoat is made from the following raw materials: a zwitterionic monomer with double bonds, an initiator, and a second solvent; The zwitterionic hydrophilic coating is prepared by a method comprising the following steps: A primer is prepared by dissolving a benzophenone-based reactive ultraviolet absorber in a first solvent. The primer is then applied to the surface of a substrate and subjected to ultraviolet light irradiation to obtain a base layer. The duration of ultraviolet light irradiation is 30 s to 5 min. A zwitterionic monomer with double bonds and an initiator are dissolved in a second solvent to prepare a topcoat. The topcoat is then applied to the surface of the primer and irradiated with ultraviolet light to obtain a topcoat layer, which is a zwitterionic hydrophilic coating.

2. The zwitterionic hydrophilic coating according to claim 1, characterized in that, The primer is made from the following raw materials in weight percentage: 2-20% benzophenone-based reactive ultraviolet absorber, and a first solvent; And / or, the topcoat is made from the following raw materials in weight percentages: 1-10% zwitterionic monomer with double bonds, 0.02-0.2% initiator, and a second solvent.

3. The zwitterionic hydrophilic coating according to claim 1, characterized in that, The benzophenone-based reactive ultraviolet absorber is prepared by a method comprising the following steps: mixing dihydroxybenzophenone and glycidyl methacrylate, and reacting them to obtain the benzophenone-based reactive ultraviolet absorber.

4. The zwitterionic hydrophilic coating according to claim 3, characterized in that, The specific steps of the reaction are as follows: react at 50-100℃ for 4-24 h.

5. The zwitterionic hydrophilic coating according to claim 1, characterized in that, The zwitterionic monomer with double bonds is selected from one or more of sulfonate betaine type monomers, carboxylate betaine type monomers, phosphate betaine type monomers, and serine methacrylate and ornithine methacrylamide.

6. The zwitterionic hydrophilic coating according to claim 1, characterized in that, The first solvent includes one or more of the following: methanol, ethanol, isopropanol, acetone, ethyl acetate, dichloromethane, and nitrile. And / or, the second solvent includes one or more of water, PBS, and physiological saline.

7. The method for preparing the zwitterionic hydrophilic coating according to any one of claims 1-6, characterized in that, Includes the following steps: 1) A primer is prepared by dissolving a benzophenone-based reactive ultraviolet absorber in a first solvent. The primer is then applied to the surface of a substrate and subjected to ultraviolet light irradiation to obtain a base coating. 2) Dissolve the zwitterionic monomer with double bonds and the initiator in a second solvent to prepare a topcoat. After applying the topcoat to the surface of the primer, irradiate it with ultraviolet light to obtain a topcoat layer, which is a zwitterionic hydrophilic coating.

8. The method for preparing the zwitterionic hydrophilic coating according to claim 7, characterized in that, In step 2), the duration of ultraviolet light irradiation is 10 min-40 min.

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