Polyurethane cleaning-resistant antifouling coating based on oxime-urethane bond and preparation method thereof

Abstract

The invention discloses a polyurethane cleaning-resistant antifouling coating based on an oxime-carbamate bond and a preparation method thereof, wherein the preparation method comprises the following steps: S1. After dehydrating the polyether diol, the polyether diol is mixed evenly with a diisocyanate, heated to 70-80°C, and a polymer A is obtained by reaction; S2. Polymer A, a solvent, a dioxime and a dibutyltin dilaurate catalyst are weighed, mixed evenly, and a polymer B is obtained by reaction; S3. Polymer B is coated on a substrate to form a sample, the prepared sample is placed at room temperature, and then the temperature is raised to 60°C for curing to obtain a coating. The antifouling coating of the present invention has good wear resistance, and the coating can undergo a hydrolysis reaction with seawater based on an oxime-carbamate bond, can meet the demand for the coating to be resistant to cleaning, and can solve the problem of marine organisms adhering to the surface of the hull to cause invasion of alien species.

Description

Technical Field

[0001] The invention relates to the field of marine antifouling coatings, and in particular to a polyurethane washable antifouling coating based on oxime-carbamate bonds and a preparation method thereof. Background Art

[0002] Marine fouling organisms are a common problem accompanying human marine activities and the development of marine industry. Once marine fouling organisms attach to the surface of artificial facilities, they will cause serious adverse effects on the substrate: the attachment of marine fouling organisms will accelerate the corrosion of the substrate, resulting in a reduction in the strength of the substrate of artificial facilities or even destruction; the attachment of marine fouling organisms will increase the deadweight of the hull and increase the roughness of the hull surface, thereby reducing the speed of the ship and accelerating the consumption of fuel; and the marine fouling organisms attached to the hull can cause species invasion to other sea areas through the transportation of the hull, destroying the ecological balance of the local sea area. In addition, the International Maritime Organization (IMO) recently passed new international rules and formulated a preliminary strategy to prevent the invasion of alien organisms. Hydrolyzable antifouling coatings can spontaneously form a constantly renewed surface and effectively inhibit the attachment of marine organisms. In addition, underwater cleaning of the hull is essential, which poses new challenges to the wear resistance of the coating. However, the hydrolyzable coatings disclosed in the prior art basically rely on ester groups for hydrolysis, and their performance has certain requirements on the speed, and the poor wear resistance limits their further application. Therefore, it is of great significance to develop an antifouling coating with excellent cleaning resistance.

[0003] Chinese patent document CN104974631A (patent number 201510391687.0) discloses a base resin with self-polishing properties and a self-polishing antifouling coating prepared therefrom, which introduces functional monomers to undergo hydrolysis reaction with weakly alkaline seawater, ultimately achieving a "layer-by-layer peeling" self-polishing effect. However, the resin is mainly hydrolyzed by side chains, and its antifouling performance has certain requirements on the speed of the ship, and the antifouling effect is poor in static waters.

[0004] Chinese patent document CN115197360A (patent number 202210806216.1) discloses a eugenol ester-based methacrylate fluorine self-polishing antifouling resin and its preparation method, which releases eugenol with antibacterial effect through the hydrolysis of the phenolic ester group to inhibit the adhesion of primary biological fouling. However, after the resin is hydrolyzed, hydrophilic carboxylate groups are formed, which gradually become brittle as the hydrophilic groups increase, and the mechanical properties of acrylic resins are poor, which limits its further application.

[0005] Chinese patent document CN116355514A (patent number 202310396033.1) discloses a coating with anti-fouling, anti-corrosion and bionic self-healing functions. The coating uses polyurethane as a film-forming material, and 1wt% of modified boron nitride is mixed into the polyurethane to simulate the fibrous structure of animal cartilage tissue; 2wt% of 2-octyl-4,5-dichloroisothiazolone is mixed into the polyurethane as an antifouling agent; bis(2-hydroxyethyl) disulfide is used as a chain extender in the preparation of polyurethane to introduce disulfide bonds, and self-healing is performed by breaking and reorganizing the disulfide bonds; wherein the modified boron nitride is prepared by ball-milling and hydroxylating boron nitride, and then introducing hexamethylene diisocyanate on the basis of the hydroxylated boron nitride for functionalization, and finally reacting with 2-amino-4-methylpyrimidine-5-carboxylic acid ethyl ester. The introduced boron nitride can improve the strength, hardness and wear resistance of polyurethane, thereby improving its mechanical properties, and improve the thermal stability and corrosion resistance of polyurethane. The introduction of antifouling agent in the coating makes the coating have antifouling ability. However, the coating cannot be hydrolyzed with seawater. The inventive concept of the invention is to introduce an antifouling agent (DCOIT) into a polyurethane composite coating based on disulfide bonds to prepare a coating with thermal self-healing, antifouling and anticorrosion functions, which is different from the inventive concept of the present invention. Summary of the invention

[0006] In view of this, in order to solve the above-mentioned technical problems, the purpose of the present invention is to propose a polyurethane cleaning-resistant antifouling coating based on oxime-carbamate bonds and a preparation method thereof. The polyurethane cleaning-resistant antifouling coating based on oxime-carbamate bonds prepared by the present invention has good wear resistance. The coating can undergo hydrolysis reaction with seawater based on the oxime-carbamate bonds, can meet the requirements of the coating being resistant to cleaning, and can solve the problem of marine organisms attaching to the surface of the hull and causing invasion of alien species.

[0007] The technical solutions adopted are:

[0008] The present invention discloses a method for preparing a polyurethane cleaning-resistant antifouling coating based on an oxime-carbamate bond, comprising the following steps:

[0009] S1. After removing water from the polyether diol, mix it evenly with the diisocyanate, heat it to 70-80°C, and react to obtain polymer A;

[0010] S2. Weigh polymer A, solvent, dioxime and dibutyltin dilaurate catalyst, mix them evenly, and react to obtain polymer B;

[0011] S3. The polymer B is coated on the substrate to prepare a sample, the prepared sample is placed at room temperature, and then the temperature is raised to 60° C. for curing to obtain a coating.

[0012] Furthermore, the diisocyanate is one or more of diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate and isophorone diisocyanate.

[0013] Furthermore, in S1, the polyether diol is one or more of polytetramethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol-propylene oxide copolymer, and the number average molecular weight thereof is 500-3000.

[0014] Furthermore, in S1, the mass ratio of polyether diol to diisocyanate is (2-10):1.

[0015] Further, in S2, the dioxime is one or more of p-benzoquinone dioxime, glyoxime, ethylenedioxime, 1,2-cyclohexanedione dioxime and diacetyl oxime.

[0016] Furthermore, the solvent is one or more of toluene, xylene, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ether, acetone, acetonitrile and dichloromethane.

[0017] Furthermore, in S2, the mass ratio of polymer A, solvent, dioxime and dibutyltin dilaurate catalyst is: 1:(1-2):(0.03-0.2):(0.004-0.01).

[0018] 8. The method for preparing a polyurethane cleaning-resistant antifouling coating based on oxime-urethane bonds according to claim 1, characterized in that, in S3, the room temperature is left for 1-12 hours, and then the temperature is raised to 60°C for curing for 24-72 hours.

[0019] Furthermore, in S3, the material of the substrate sample is wood, metal, plastic or glass; and the coating is drip coating, spin coating or spray coating.

[0020] The polyurethane washing-resistant and antifouling coating based on oxime-carbamate bonds of the present invention is prepared by the preparation method described in any one of the above schemes.

[0021] In the above technical solution,

[0022] The present invention uses polyether diol and diisocyanate as raw materials to prepare a prepolymer, and uses dioxime as a curing agent to prepare a polyurethane coating. In the marine environment, the oxime-carbamate bond of the coating undergoes a hydrolysis reaction with seawater, and the dioxime with antifouling properties is released to inhibit the attachment of fouling organisms, and then the newly exposed coating continues to undergo a hydrolysis reaction with seawater, and finally achieves a layer-by-layer peeling effect. In addition, due to the double covalent bond, the coating has good wear resistance and can meet the requirements of coating resistance to cleaning.

[0023] In summary, compared with the prior art, the present invention has the following advantages:

[0024] 1. The present invention is the first to prepare a hydrolyzable antifouling coating through oxime-carbamate bonds. The hydrolysis rate of the coating can be adjusted by regulating the oxime-carbamate bond content to meet the needs of different sea areas.

[0025] 2. The oxime-carbamate bond of the antifouling coating of the present invention undergoes a hydrolysis reaction with seawater, and the dioxime with antifouling properties is released, further inhibiting the attachment of fouling organisms. Subsequently, the newly exposed coating continues to undergo a hydrolysis reaction with seawater, and finally achieves a layer-by-layer peeling effect. The seawater will wash away the fouling organisms on the surface, inhibit the adhesion of initial proteins and bacteria, and reduce the chance of large-scale fouling attachment, thereby greatly reducing the possibility of invasion by alien species.

[0026] 3. The antifouling coating of the present invention has double covalent bonds formed by oxime-carbamate dynamic bonds and hydrogen bonds, and the molecules are cross-linked with each other, so it has excellent wear resistance and can meet the requirements of coating resistance to cleaning. Before the ship arrives at the port, cleaning the surface of the hull can prevent the invasion of foreign species.

[0027] 4. The antifouling coating of the present invention has a simple preparation process and low cost. It can be applied to most polyurethane coatings using dioxime as a curing agent, and has broad prospects for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the synthetic reaction diagram of polyurethane cleaning resistant coating;

[0029] Figure 2 This is the experimental result diagram of the contact angle of the polyurethane cleaning-resistant coating before and 7 days after hydrolysis;

[0030] Figure 3 This is a microscope picture of the test results of the polyurethane washable coating against the double-browed algae;

[0031] Figure 4 This is the experimental result of the first day anti-double eyelid algae rate of the polyurethane washable coating;

[0032] Figure 5 This is the experimental result of the anti-double-eyebrow algae rate of the polyurethane washable coating on the third day;

[0033] Figure 6 This is a digital picture of the antibacterial test results of the polyurethane washable coating;

[0034] Figure 7 This is the experimental result graph of the anti-E. coli rate of the polyurethane washable coating;

[0035] Figure 8This is the experimental result graph of the anti-Aureus coccus rate of the polyurethane washable coating;

[0036] Fig. 9 is a graph of the wear mass loss of a polyurethane washable coating. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only partial embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Example 1

[0039] A method for preparing a polyurethane cleaning-resistant antifouling coating based on an oxime-carbamate bond in this embodiment comprises the following steps:

[0040] a) Step 1: Preparation of polyurethane prepolymer

[0041] 50 g of polytetramethylene ether diol was heated in a round-bottom flask at 110° C. under vacuum for 2 h to remove moisture, and then cooled to room temperature. 14.8 g of hexamethylene diisocyanate was added to a round-bottom flask equipped with a thermometer, a magnetic stirrer and a reflux condenser, and then heated to 70° C. for reaction for 2 h to obtain a polyurethane prepolymer;

[0042] b) Step 2: Preparation of polyurethane antifouling coating

[0043] Weigh 10g of polyurethane prepolymer into a container, weigh 15g of solvent and 1.1g of dimethylglyoxime and add them to the polyurethane prepolymer, then add 0.05g of dibutyltin dilaurate catalyst, and then put it into a degassing machine for stirring and degassing. After the reaction is completed, the solution obtained is recorded as B. The reaction formula is as follows: Figure 1 As shown;

[0044] c) Step 3: Spin-coat the product B on the substrate by spin coating. Place the prepared sample at room temperature for 1 hour, and heat it to 60° C. for curing for 24 hours to obtain coating c;

[0045] Laboratory contact angle test: The static contact angle of the polyurethane cleaning-resistant coating before and after hydrolysis was measured using OCA-20. Figure 2 This is a comparison chart of the contact angles of the polyurethane cleaning-resistant coating before and after hydrolysis for 7 days. It can be observed that the contact angles before and after hydrolysis are almost the same.

[0046] Laboratory static diatom inhibition experiment: The sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as a blank control. The sample and the blank were immersed in the liquid of the double-browed algae for 1 day and 3 days. After taking out the sample, the unattached algae were removed, and the algae attachment on the coating was photographed under an optical microscope. Figure 3 This is a microscope picture of the anti-Dinocampus algae test results of the polyurethane washable coating. Compared with the control group, the adhesion of Dinocampus algae on the coating surface is significantly reduced. Figure 4 and Figure 5 It is the first day / third day anti-diatom rate of the polyurethane washable coating. Three areas of each coating were randomly selected for shooting, and finally compared with the blank sample, the inhibition rates of diatoms were calculated as 100% and 96.6% respectively.

[0047] Laboratory static antibacterial experiment: the sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as the blank control. The sample and the blank were co-cultured with bacteria (Escherichia coli, Staphylococcus aureus) at 37°C for 12h and 24h, and after dilution to equal concentration, the bacterial solution was spread on the solid culture medium by the plate spreading method (each sample was spread 3 times in parallel), and incubated at 37°C for 12h and 24h, the plate was taken out, and the number of bacteria adhering to the coating surface was determined by plate counting. Figure 6 This is a digital picture of the antibacterial test results of the polyurethane washable coating. It can be seen that the number of colonies on the coating surface is significantly reduced compared to the blank. The colony counting method is used to calculate the number of colonies on the sample and the blank. Figure 7 and Figure 8 It is the anti-Escherichia coli / Aureus coccus rate of the polyurethane washable coating, and the calculated antibacterial rates are 84.9% and 96.5% respectively.

[0048] Laboratory wear test: The wear resistance of the coating was tested by a tabletop wear tester. The turntable speed was set at 60r / min, and the cycle was 500 times. The weight loss was expressed as the difference in the coating mass before and after the experiment. Fig. 9 This is the wear mass loss diagram of the polyurethane cleaning resistant coating. The calculated mass loss is: 0.025g.

[0049] Example 2

[0050] A method for preparing a polyurethane cleaning-resistant antifouling coating based on an oxime-carbamate bond in this embodiment comprises the following steps:

[0051] a) Step 1: Preparation of polyurethane prepolymer

[0052] 60 g of polytetramethylene ether diol was heated in a round-bottom flask at 110° C. under vacuum for 2 h to remove moisture, and then cooled to room temperature. 14.8 g of hexamethylene diisocyanate was added to a round-bottom flask equipped with a thermometer, a magnetic stirrer and a reflux condenser, and then heated to 70° C. for reaction for 2 h to obtain a polyurethane prepolymer;

[0053] b) Step 2: Preparation of polyurethane antifouling coating

[0054] Weigh 10g of polyurethane prepolymer into a container, weigh 15g of solvent and 0.88g of dimethylglyoxime and add them to the polyurethane prepolymer, then add 0.05g of dibutyltin dilaurate catalyst, and then put it into a degassing machine for stirring and degassing. After the reaction is completed, the solution obtained is recorded as B. The reaction formula is as follows: Figure 1 As shown;

[0055] c) Step 3: Spin-coat the product B on the substrate by spin coating. Place the prepared sample at room temperature for 1 hour, and heat it to 60° C. for curing for 24 hours to obtain coating c;

[0056] Laboratory contact angle test: The static contact angle of the polyurethane cleaning-resistant coating before and after hydrolysis was measured using OCA-20. Figure 2 This is a comparison chart of the contact angles of the polyurethane cleaning-resistant coating before and after hydrolysis for 7 days. It can be observed that the contact angles before and after hydrolysis are almost the same.

[0057] Laboratory static diatom inhibition experiment: The sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as a blank control. The sample and the blank were immersed in the liquid of the double-browed algae for 1 day and 3 days. After taking out the sample, the unattached algae were removed, and the algae attachment on the coating was photographed under an optical microscope. Figure 3 This is a microscope picture of the anti-Dinocampus algae test results of the polyurethane washable coating. Compared with the control group, the adhesion of Dinocampus algae on the coating surface is significantly reduced. Figure 4 and Figure 5 It is the first day / third day anti-diatom rate of the polyurethane washable coating. Three areas of each coating were randomly selected for shooting, and finally compared with the blank sample, the diatom inhibition rates were calculated to be 96.3% and 93.5% respectively.

[0058] Laboratory static antibacterial experiment: the sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as the blank control. The sample and the blank were co-cultured with bacteria (Escherichia coli, Staphylococcus aureus) at 37°C for 12h and 24h, and after dilution to equal concentration, the bacterial solution was spread on the solid culture medium by the plate spreading method (each sample was spread 3 times in parallel), and incubated at 37°C for 12h and 24h, the plate was taken out, and the number of bacteria adhering to the coating surface was determined by plate counting. Figure 6This is a digital picture of the antibacterial test results of the polyurethane washable coating. It can be seen that the number of colonies on the coating surface is significantly reduced compared to the blank. The colony counting method is used to calculate the number of colonies on the sample and the blank. Figure 7 and Figure 8 It is the anti-Escherichia coli / Aureus coccus rate of the polyurethane washable coating, and the calculated antibacterial rates are 76.7% and 80.7% respectively.

[0059] Laboratory wear test: The wear resistance of the coating was tested by a tabletop wear tester. The turntable speed was set at 60r / min, and the cycle was 500 times. The weight loss was expressed as the difference in the coating mass before and after the experiment. Fig. 9 This is the wear mass loss diagram of the polyurethane cleaning resistant coating. The calculated mass loss is: 0.031g.

[0060] Example 3

[0061] A method for preparing a polyurethane cleaning-resistant antifouling coating based on an oxime-carbamate bond in this embodiment comprises the following steps:

[0062] a) Step 1: Preparation of polyurethane prepolymer

[0063] 70 g of polytetramethylene ether diol was heated in a round-bottom flask at 110° C. under vacuum for 2 h to remove moisture, and then cooled to room temperature. 14.8 g of hexamethylene diisocyanate was added to a round-bottom flask equipped with a thermometer, a magnetic stirrer and a reflux condenser, and then heated to 70° C. for reaction for 2 h to obtain a polyurethane prepolymer;

[0064] b) Step 2: Preparation of polyurethane antifouling coating

[0065] Weigh 10g of polyurethane prepolymer into a container, weigh 15g of solvent and 0.71g of dimethylglyoxime and add them to the polyurethane prepolymer, then add 0.05g of dibutyltin dilaurate catalyst, and then put it into a degassing machine for stirring and degassing. After the reaction is completed, the solution obtained is recorded as B. The reaction formula is as follows: Figure 1 As shown;

[0066] c) Step 3: Spin-coat the product B on the substrate by spin coating. Place the prepared sample at room temperature for 1 hour, and heat it to 60° C. for curing for 24 hours to obtain coating c;

[0067] Laboratory contact angle test: The static contact angle of the polyurethane cleaning-resistant coating before and after hydrolysis was measured using OCA-20. Figure 2 This is a comparison chart of the contact angles of the polyurethane cleaning-resistant coating before and after hydrolysis for 7 days. It can be observed that the contact angles before and after hydrolysis are almost the same.

[0068] Laboratory static diatom inhibition experiment: The sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as a blank control. The sample and the blank were immersed in the liquid of the double-browed algae for 1 day and 3 days. After taking out the sample, the unattached algae were removed, and the algae attachment on the coating was photographed under an optical microscope. Figure 3 This is a microscope picture of the anti-Dinocampus algae test results of the polyurethane washable coating. Compared with the control group, the adhesion of Dinocampus algae on the coating surface is significantly reduced. Figure 4 and Figure 5 It is the first day / third day anti-diatom rate of the polyurethane washable coating. Three areas of each coating were randomly selected for shooting, and finally compared with the blank sample, the diatom inhibition rates were calculated to be 94.4% and 91.6% respectively.

[0069] Laboratory static antibacterial experiment: the sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as the blank control. The sample and the blank were co-cultured with bacteria (Escherichia coli, Staphylococcus aureus) at 37°C for 12h and 24h, and after dilution to equal concentration, the bacterial solution was spread on the solid culture medium by the plate spreading method (each sample was spread 3 times in parallel), and incubated at 37°C for 12h and 24h, the plate was taken out, and the number of bacteria adhering to the coating surface was determined by plate counting. Figure 6 This is a digital picture of the antibacterial test results of the polyurethane washable coating. It can be seen that the number of colonies on the coating surface is significantly reduced compared to the blank. The colony counting method is used to calculate the number of colonies on the sample and the blank. Figure 7 and Figure 8 It is the anti-Escherichia coli / Aureus coccus rate of the polyurethane washable coating, and the calculated antibacterial rates are 69.4% and 77.8% respectively.

[0070] Laboratory wear test: The wear resistance of the coating was tested by a tabletop wear tester. The turntable speed was set at 60r / min, and the cycle was 500 times. The weight loss was expressed as the difference in the coating mass before and after the experiment. Fig. 9 This is the wear mass loss graph of the polyurethane cleaning resistant coating. The calculated mass loss is: 0.052g.

[0071] Example 4

[0072] A method for preparing a polyurethane cleaning-resistant antifouling coating based on an oxime-carbamate bond in this embodiment comprises the following steps:

[0073] a) Step 1: Preparation of polyurethane prepolymer

[0074] 80 g of polytetramethylene ether diol was heated in a round-bottom flask at 110° C. under vacuum for 2 h to remove moisture, and then cooled to room temperature. 14.8 g of hexamethylene diisocyanate was added to a round-bottom flask equipped with a thermometer, a magnetic stirrer and a reflux condenser, and then the temperature was raised to 70° C. for reaction for 2 h to obtain a polyurethane prepolymer;

[0075] b) Step 2: Preparation of polyurethane antifouling coating

[0076] Weigh 10g of polyurethane prepolymer into a container, weigh 15g of solvent and 0.58g of dimethylglyoxime and add them to the polyurethane prepolymer, then add 0.05g of dibutyltin dilaurate catalyst, and then put it into a degassing machine for stirring and degassing. After the reaction is completed, the solution obtained is recorded as B. The reaction formula is as follows: Figure 1 As shown;

[0077] c) Step 3: Spin-coat the product B on the substrate by spin coating. Place the prepared sample at room temperature for 1 hour, and heat it to 60° C. for curing for 24 hours to obtain coating c;

[0078] Laboratory contact angle test: The static contact angle of the polyurethane cleaning-resistant coating before and after hydrolysis was measured using OCA-20. Figure 2 This is a comparison chart of the contact angles of the polyurethane cleaning-resistant coating before and after hydrolysis for 7 days. It can be observed that the contact angles before and after hydrolysis are almost the same.

[0079] Laboratory static diatom inhibition experiment: The sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as a blank control. The sample and the blank were immersed in the liquid of the double-browed algae for 1 day and 3 days. After taking out the sample, the unattached algae were removed, and the algae attachment on the coating was photographed under an optical microscope. Figure 3 This is a microscope picture of the anti-Dinocampus algae test results of the polyurethane washable coating. Compared with the control group, the adhesion of Dinocampus algae on the coating surface is significantly reduced. Figure 4 and Figure 5 It is the first day / third day anti-diatom rate of the polyurethane washable coating. Three areas of each coating were randomly selected for shooting, and finally compared with the blank sample, the diatom inhibition rates were calculated to be 91.7% and 90.1% respectively.

[0080] Laboratory static antibacterial experiment: the sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as the blank control. The sample and the blank were co-cultured with bacteria (Escherichia coli, Staphylococcus aureus) at 37°C for 12h and 24h, and after dilution to equal concentration, the bacterial solution was spread on the solid culture medium by the plate spreading method (each sample was spread 3 times in parallel), and incubated at 37°C for 12h and 24h, the plate was taken out, and the number of bacteria adhering to the coating surface was determined by plate counting. Figure 6This is a digital picture of the antibacterial test results of the polyurethane washable coating. It can be seen that the number of colonies on the coating surface is significantly reduced compared to the blank. The colony counting method is used to calculate the number of colonies on the sample and the blank. Figure 7 and Figure 8 It is the anti-Escherichia coli / Aureus coccus rate of the polyurethane washable coating, and the calculated antibacterial rates are 60.1% and 74.8% respectively.

[0081] Laboratory wear test: The wear resistance of the coating was tested by a tabletop wear tester. The turntable speed was set at 60r / min, and the cycle was 500 times. The weight loss was expressed as the difference in the coating mass before and after the experiment. Fig. 9 This is the wear mass loss diagram of the polyurethane cleaning resistant coating. The calculated mass loss is: 0.079g.

[0082] Example 5

[0083] A method for preparing a polyurethane cleaning-resistant antifouling coating based on an oxime-carbamate bond in this embodiment comprises the following steps:

[0084] a) Step 1: Preparation of polyurethane prepolymer

[0085] 90 g of polytetrahydrofuran ether diol was heated in a round-bottom flask at 110° C. under vacuum for 2 h to remove moisture, and then cooled to room temperature. 14.8 g of hexamethylene diisocyanate was added to a round-bottom flask equipped with a thermometer, a magnetic stirrer and a reflux condenser, and then the temperature was raised to 70° C. for reaction for 2 h to obtain a polyurethane prepolymer;

[0086] b) Step 2: Preparation of polyurethane antifouling coating

[0087] Weigh 10g of polyurethane prepolymer into a container, weigh 15g of solvent and 0.47g of dimethylglyoxime and add them to the polyurethane prepolymer, then add 0.05g of dibutyltin dilaurate catalyst, and then put it into a degassing machine for stirring and degassing. After the reaction is completed, the solution obtained is recorded as B. The reaction formula is as follows: Figure 1 As shown;

[0088] c) Step 3: Spin-coat the product B on the substrate by spin coating. Place the prepared sample at room temperature for 1 hour, and heat it to 60° C. for curing for 24 hours to obtain coating c;

[0089] Laboratory contact angle test: The static contact angle of the polyurethane cleaning-resistant coating before and after hydrolysis was measured using OCA-20. Figure 2 This is a comparison chart of the contact angles of the polyurethane cleaning-resistant coating before and after hydrolysis for 7 days. It can be observed that the contact angles before and after hydrolysis are almost the same.

[0090] Laboratory static diatom inhibition experiment: The sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as a blank control. The sample and the blank were immersed in the liquid of the double-browed algae for 1 day and 3 days. After taking out the sample, the unattached algae were removed, and the algae attachment on the coating was photographed under an optical microscope. Figure 3 This is a microscope picture of the anti-Dinocampus algae test results of the polyurethane washable coating. Compared with the control group, the adhesion of Dinocampus algae on the coating surface is significantly reduced. Figure 4 and Figure 5 It is the first day / third day anti-diatom rate of the polyurethane washable coating. Three areas of each coating were randomly selected for shooting, and finally compared with the blank sample, the diatom inhibition rates were calculated to be 89.8% and 86.5% respectively.

[0091] Laboratory static antibacterial experiment: the sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as the blank control. The sample and the blank were co-cultured with bacteria (Escherichia coli, Staphylococcus aureus) at 37°C for 12h and 24h, and after dilution to equal concentration, the bacterial solution was spread on the solid culture medium by the plate spreading method (each sample was spread 3 times in parallel), and incubated at 37°C for 12h and 24h, the plate was taken out, and the number of bacteria adhering to the coating surface was determined by plate counting. Figure 6 This is a digital picture of the antibacterial test results of the polyurethane washable coating. It can be seen that the number of colonies on the coating surface is significantly reduced compared to the blank. The colony counting method is used to calculate the number of colonies on the sample and the blank. Figure 7 and Figure 8 It is the anti-Escherichia coli / Aureus coccus rate of the polyurethane washable coating, and the calculated antibacterial rates are 35.3% and 63.4% respectively.

[0092] Laboratory wear test: The wear resistance of the coating was tested by a tabletop wear tester. The turntable speed was set at 60r / min, and the cycle was 500 times. The weight loss was expressed as the difference in the coating mass before and after the experiment. Fig. 9 This is the wear mass loss diagram of the polyurethane cleaning resistant coating. The calculated mass loss is: 0.086g.

[0093] Example 6

[0094] A method for preparing a polyurethane cleaning-resistant antifouling coating based on an oxime-carbamate bond in this embodiment comprises the following steps:

[0095] a) Step 1: Preparation of polyurethane prepolymer

[0096] 100 g of polytetramethylene ether diol was heated in a round-bottom flask at 110° C. under vacuum for 2 h to remove moisture, and then cooled to room temperature. 14.8 g of hexamethylene diisocyanate was added to a round-bottom flask equipped with a thermometer, a magnetic stirrer and a reflux condenser, and then the temperature was raised to 70° C. for reaction for 2 h to obtain a polyurethane prepolymer;

[0097] b) Step 2: Preparation of polyurethane antifouling coating

[0098] Weigh 10g of polyurethane prepolymer into a container, weigh 15g of solvent and 0.38g of dimethylglyoxime and add them to the polyurethane prepolymer, then add 0.05g of dibutyltin dilaurate catalyst, and then put it into a degassing machine for stirring and degassing. After the reaction is completed, the solution obtained is recorded as B. The reaction formula is as follows: Figure 1 As shown;

[0099] c) Step 3: Spin-coat the product B on the substrate by spin coating. Place the prepared sample at room temperature for 1 hour, and heat it to 60° C. for curing for 24 hours to obtain coating c;

[0100] Laboratory contact angle test: The static contact angle of the polyurethane cleaning-resistant coating before and after hydrolysis was measured using OCA-20. Figure 2 This is a comparison chart of the contact angles of the polyurethane cleaning-resistant coating before and after hydrolysis for 7 days. It can be observed that the contact angles before and after hydrolysis are almost the same.

[0101] Laboratory static diatom inhibition experiment: The sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as a blank control. The sample and the blank were immersed in the liquid of the double-browed algae for 1 day and 3 days. After taking out the sample, the unattached algae were removed, and the algae attachment on the coating was photographed under an optical microscope. Figure 3 This is a microscope picture of the anti-Dinocampus algae test results of the polyurethane washable coating. Compared with the control group, the adhesion of Dinocampus algae on the coating surface is significantly reduced. Figure 4 and Figure 5 It is the first day / third day anti-diatom rate of the polyurethane washable coating. Three areas of each coating were randomly selected for shooting, and finally compared with the blank sample, the diatom inhibition rates were calculated to be 82.4% and 78.9% respectively.

[0102] Laboratory static antibacterial experiment: the sample coating size was made into 2.5cm×3.5cm, and a glass slide was selected as the blank control. The sample and the blank were co-cultured with bacteria (Escherichia coli, Staphylococcus aureus) at 37°C for 12h and 24h, and after dilution to equal concentration, the bacterial solution was spread on the solid culture medium by the plate spreading method (each sample was spread 3 times in parallel), and incubated at 37°C for 12h and 24h, the plate was taken out, and the number of bacteria adhering to the coating surface was determined by plate counting. Figure 6This is a digital picture of the antibacterial test results of the polyurethane washable coating. It can be seen that the number of colonies on the coating surface is significantly reduced compared to the blank. The colony counting method is used to calculate the number of colonies on the sample and the blank. Figure 7 and Figure 8 It is the anti-Escherichia coli / Aureus coccus rate of the polyurethane washable coating, and the calculated antibacterial rates are 18.6% and 49.6% respectively.

[0103] Laboratory wear test: The wear resistance of the coating was tested by a tabletop wear tester. The turntable speed was set at 60r / min, and the cycle was 500 times. The weight loss was expressed as the difference in the coating mass before and after the experiment. Fig. 9 This is the wear mass loss diagram of the polyurethane cleaning resistant coating. The calculated mass loss is: 0.10g.

[0104] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a polyurethane cleaning-resistant antifouling coating based on an oxime-carbamate bond, characterized in that: The following steps are involved: S1. After removing water from the polyether diol, mix it evenly with diisocyanate, heat it to 70-80°C, and react to obtain polymer A; the polyether diol is polytetramethylene diisocyanate; the diisocyanate is hexamethylene diisocyanate; the mass ratio of polyether diol to diisocyanate is (2-10):1; S2. Weigh polymer A, solvent, dioxime and dibutyltin dilaurate catalyst, mix them evenly, and react to obtain polymer B; the dioxime is dimethylglyoxime; the mass ratio of polymer A, solvent, dioxime and dibutyltin dilaurate catalyst is: 1: (1-2): (0.03-0.2): (0.004-0.01); S3. The polymer B is coated on the substrate to prepare a sample, the prepared sample is placed at room temperature, and then the temperature is raised to 60° C. for curing to obtain a coating.

2. The method for preparing the polyurethane cleaning-resistant antifouling coating based on oxime-urethane bonds according to claim 1, characterized in that: The solvent is one or more of toluene, xylene, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ether, acetone, acetonitrile and dichloromethane.

3. The method for preparing the polyurethane cleaning-resistant antifouling coating based on oxime-urethane bonds according to claim 1, characterized in that: In S3, the room temperature is left for 1-12 hours, and then the temperature is raised to 60° C. for curing for 24-72 hours.

4. The method for preparing the polyurethane cleaning-resistant antifouling coating based on oxime-urethane bonds according to claim 1, characterized in that: In S3, the material of the substrate sample is wood, metal, plastic or glass; and the coating is drop coating, spin coating or spray coating.

5. A polyurethane cleaning-resistant antifouling coating based on oxime-carbamate bonds, characterized in that: The invention is prepared by the preparation method described in any one of claims 1 to 4.

Images