A functional silane-modified polyurethane antifouling coating, its preparation method and application

Abstract

The present invention discloses a functional silane-modified polyurethane antifouling coating, its preparation method and application. The antifouling coating consists of component A and component B. Component A includes a functional silane-modified polyurethane prepolymer, and component B includes a chain extender. The weight ratio of the functional silane-modified polyurethane prepolymer to the chain extender is 1:0.01 - 0.6. Preferably, component A mainly consists of the following raw materials: 500 parts of functional silane-modified polyurethane prepolymer, 30 - 80 parts of bentonite, 50 - 100 parts of titanium dioxide, 100 - 250 parts of zinc oxide, and 10 - 30 parts of talc powder; by weight, component B mainly consists of the following raw materials: 3 - 5 parts of a leveling agent, 3 - 5 parts of an antifoaming agent, 50 - 300 parts of a chain extender, 6 - 30 parts of a silane coupling agent, 1 - 2 parts of a catalyst, and 50 - 150 parts of a diluent. The antifouling coating of the present invention has good adhesion and antifouling performance.

Description

Technical Field

[0001] The present invention relates to the technical field of antifouling coatings, and particularly relates to a functional silane-modified polyurethane antifouling coating, a preparation method thereof, and an application thereof. Background Art

[0002] Polydimethylsiloxane is used as a hydrophobic modifier in the fields of coatings, textiles, and daily chemicals, and can provide good hydrophobicity and low surface energy characteristics. It is one of the commonly used matrix resins in coatings. As a key component in antifouling coatings, antifouling active ingredients play a crucial role in reducing the marine biofouling suffered by ships and coastal facilities after being immersed in seawater. The antifouling agents added in traditional antifouling coatings will leach into seawater, increasing the usage amount of antifouling agents and having an adverse impact on the marine environment or facility pipelines.

[0003] Chinese patent document CN115651136A (patent number 202211620706.9) discloses a preparation method of a polar marine antifouling resin, which uses acrylic acid to react with an isothiazolone antifouling derivative to form a functional monomer, and synthesizes an acrylic resin to enhance the antifouling ability.

[0004] Chinese patent document CN115141508B (patent number 202210538925.6) discloses a long-acting metal-organic framework material-loaded antifouling agent and a preparation method thereof, which uses a metal-organic framework to coat an isothiazole antifouling derivative, and adds the isothiazole antifouling derivative with a slow-release property to an acrylic resin, so that the antifouling performance of the coating is greatly improved.

[0005] Chinese patent document CN113968950B (patent number 202111362163.0) discloses a bactericidal diol chain extender, a preparation method thereof, and an application in a multifunctional synergistic antifouling waterborne polyurethane. The isothiazole antifouling derivative is used to prepare a functional diol and introduced into a polyurethane resin, so that the antibacterial and anti-bacterial adhesion abilities of the coating are greatly improved.

[0006] The present invention starts from different inventive concepts and develops a new polyurethane antifouling coating. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a functional silane-modified polyurethane antifouling coating, a preparation method thereof, and an application thereof. The functional silane-modified polyurethane antifouling coating has good adhesion and antifouling performance.

[0008] The technical solution adopted is as follows:

[0009] A functional silane-modified polyurethane antifouling coating of the present invention is composed of component A and component B. Component A includes a functional silane-modified polyurethane prepolymer, and component B includes a chain extender. The weight ratio of the functional silane-modified polyurethane prepolymer to the chain extender is 1:0.01 - 0.6.

[0010] Further, the functional silane-modified polyurethane prepolymer is prepared by the following steps:

[0011] S1. Dehydrated epoxy-terminated polydimethylsiloxane and an amino-containing antifouling active ingredient are added to a four-necked flask equipped with a mechanical stirring device, a thermometer, a constant pressure dropping funnel, and a condenser. N,N-dimethylformamide and ethyl acetate are added to make the reactants mix evenly, and then the temperature is raised to 80 - 100 °C and kept warm for 6 - 12 hours until the clear solid in the system disappears, obtaining a functional silane.

[0012] S2. At room temperature, dehydrated polyether polyol and the functional silane are added. The temperature of the system is raised to 50 - 60 °C, and isocyanate is dropped into it. After mixing evenly, the temperature of the system is raised to 80 - 85 °C, and after keeping warm for 2 - 2.5 h, it is cooled to room temperature.

[0013] Further, the molecular structural formula of the epoxy-terminated polydimethylsiloxane is as follows:

[0014] where R is The repeating segment n is 1 - 38.

[0015] Further, the amino-containing antifouling active ingredient has active amino groups capable of reacting with epoxy groups, and the amino-containing antifouling active ingredient is one or more of thiazole and its derivatives. The thiazole and its derivatives include, for example, one or more of 2-aminobenzothiazole, 2-amino-5-chloro-4-methylthiazole, thifluzamide, and thiamethoxam.

[0016] Further, the chain extender is a liquid amine chain extender. The liquid amine chain extender is, for example, isophorone diamine or NH1420.

[0017] Further, it is composed of component A and component B; by weight, component A is mainly composed of the following raw materials:

[0018] 500 parts of functional silane-modified polyurethane prepolymer, 30 - 80 parts of bentonite, 50 - 100 parts of titanium dioxide, 100 - 250 parts of zinc oxide, 10 - 30 parts of talc powder;

[0019] Component B is mainly composed of the following raw materials:

[0020] 3 - 5 parts of leveling agent, 3 - 5 parts of defoaming agent, 50 - 300 parts of chain extender, 6 - 30 parts of silane coupling agent, 1 - 2 parts of catalyst, 50 - 150 parts of diluent.

[0021] Further, the silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, bis-(γ-trimethoxysilylpropyl)amine, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, N-butyl-γ-aminopropyltrimethoxysilane, and N-butyl-γ-aminopropyltriethoxysilane.

[0022] Further, the catalyst is one or more of dibutyltin dilaurate and dibutyltin diacetate.

[0023] A preparation method of the functional silane-modified polyurethane antifouling coating according to the present invention includes the following steps:

[0024] S1. Add the raw materials of component A into a high-speed disperser and disperse at high speed for 15-45 minutes to obtain component A;

[0025] S2. Add the raw materials of component B into a high-speed disperser and disperse at high speed for 15-25 minutes to obtain component B.

[0026] During use, mix component A and component B in a mass ratio of 1-3:1 and mix evenly, and stand at room temperature for curing.

[0027] An application of the functional silane-modified polyurethane antifouling coating according to the present invention on ships and coastal facilities.

[0028] The beneficial effects of the present invention are as follows:

[0029] (1) The low surface energy provided by the silane segment helps to remove biological fouling in a dynamic environment. Different from other silanes with only silicon-oxygen repeating units, the prepared modified silane is prepared by an antifouling active ingredient and epoxy silicone oil, and has a unique synergistic effect.

[0030] (2) Among them, the amino-containing antifouling active ingredient has reactive amino groups that can react with epoxy groups, and the amino-containing antifouling active ingredient is one or more of thiazole and its derivatives. Thiazole and its derivatives are multifunctional compounds and have biological activities in the fields of cancer cell treatment, antibacterial, pesticides, etc. On this basis, the antifouling activities of some thiazole derivatives are verified. Combining the antifouling active group with the silane segment by chemical bonding can reduce the use of antifouling agents while achieving the synergistic antifouling of low surface energy and antifouling groups. The modified silane prepared by using the antifouling active group and silane can provide the dual functions of antifouling activity and low surface, and the coating performance can be adjusted by adding different proportions, further enhancing the coating effect.

[0031] (3) After the prepared functional silane-modified polyurethane coating is immersed in water, the modified silane chain segments migrate to the coating surface, achieving the enrichment of silicon elements, which can effectively improve the antifouling performance. The formed special structure can maintain the low surface energy property of the coating and further reduce the attachment of fouling.

[0032] (4) The present invention is a two-component polyurethane coating, which has good adhesion and antifouling performance. It can be mixed in proportion during use, and the coating can be cured at room temperature, with the characteristic of simple construction. Detailed implementation manners

[0033] The present invention will be described in detail below through specific examples. However, the uses and purposes of these exemplary embodiments are only used to illustrate the present invention, and do not constitute any form of limitation to the actual protection scope of the present invention, nor will the protection scope of the present invention be limited thereto.

[0034] It should be noted that the present invention does not particularly limit the specific types of some additives in component A or component B. Those skilled in the art can select the corresponding additives commonly used in the art. For example, the leveling agent is one or two of commercially available products such as BYK-R-605 and BYK-R-606 from Germany, and the defoaming agent is commercially available DAPRO-AP-7010 from Elementis etc. As long as it can ensure that the corresponding additives play their corresponding roles.

[0035] Example 1

[0036] A functional silane-modified polyurethane antifouling coating in this example is composed of component A and component B, wherein component A includes a functional silane-modified polyurethane prepolymer, and component B includes a chain extender.

[0037] Among them, the preparation method of the functional silane-modified polyurethane prepolymer includes the following steps:

[0038] First, add 100 g of dehydrated epoxy-terminated polydimethylsiloxane (average molecular weight 1000) and 30.04 g of 2-aminobenzothiazole into a four-necked flask equipped with a mechanical stirring device, a thermometer, a constant pressure dropping funnel and a condenser. Add 10 g of N,N-dimethylformamide and 20 g of ethyl acetate to make the reactants mix evenly, then heat up to 100 °C and keep warm for 12 hours until the clear solid in the system disappears, obtaining a kind of functional silane.

[0039] Secondly, add 100 g of dehydrated polytetrahydrofuran ether (molecular weight 1000) and the above-mentioned functional silane at room temperature. Heat the system to 50 - 60 °C and dropwise add 100.1 g of isophorone diisocyanate to it. After mixing evenly, heat the system to 80 - 85 °C, keep warm for 2 - 2.5 h and then cool down to room temperature, obtaining the functional silane-modified polyurethane prepolymer.

[0040] 20 g of the prepared functional silane-modified polyurethane prepolymer was added in accordance with the amount and cured with 7 g of chain extender NH1420 to obtain a functional silane-modified polyurethane antifouling coating.

[0041] Example 2

[0042] A functional silane-modified polyurethane antifouling coating in this example is composed of component A and component B. Component A includes a functional silane-modified polyurethane prepolymer, and component B includes a chain extender.

[0043] Among them, the preparation method of the functional silane-modified polyurethane prepolymer includes the following steps:

[0044] First, 200 g of dehydrated epoxy-terminated polydimethylsiloxane (molecular weight 2000), 14.86 g of 2-amino-5-chloro-4-methylthiazole, and 15.02 g of 2-aminobenzothiazole were added to a four-necked flask equipped with a mechanical stirring device, a thermometer, a constant pressure dropping funnel, and a condenser. 10 g of N,N-dimethylformamide and 20 g of ethyl acetate were added to make the reactants mix evenly, and then the temperature was raised to 100 °C and kept warm for 12 hours until the clear solid in the system disappeared, obtaining a kind of functional silane.

[0045] Second, 200 g of dehydrated polytetrahydrofuran ether (molecular weight 1000) and the above-mentioned functional silane were added at room temperature. The temperature of the system was raised to 50 - 60 °C, and 150 g of hexamethylene diisocyanate trimer was added dropwise thereto. After mixing evenly, the temperature of the system was raised to 80 - 85 °C, and after keeping warm for 2 - 2.5 h, it was cooled to room temperature to obtain a functional silane-modified polyurethane prepolymer.

[0046] 20 g of the prepared functional silane-modified polyurethane prepolymer was added in accordance with the amount and cured with 2 g of chain extender isophorone diamine to obtain a functional silane-modified polyurethane antifouling coating.

[0047] Example 3

[0048] A functional silane-modified polyurethane antifouling coating in this example is composed of component A and component B. Component A includes a functional silane-modified polyurethane prepolymer, and component B includes a chain extender.

[0049] Among them, the preparation method of the functional silane-modified polyurethane prepolymer includes the following steps:

[0050] First, 36.2 g of dehydrated epoxy-terminated polydimethylsiloxane (molecular weight 362) and 30.04 g of 2-aminobenzothiazole were added to a four-necked flask equipped with a mechanical stirring device, a thermometer, a constant pressure dropping funnel, and a condenser. 10 g of N,N-dimethylformamide and 20 g of ethyl acetate were added to make the reactants mix evenly, and then the temperature was raised to 80 °C and kept warm for 12 hours until the clear solid in the system disappeared, obtaining a kind of functional silane.

[0051] Secondly, add 200 g of dehydrated polytetrahydrofuran ether (molecular weight 1000) and the above functional silane at room temperature. Heat the system to 50 - 60 °C and dropwise add 150 g of hexamethylene diisocyanate trimer into it. After mixing evenly, heat the system to 80 - 85 °C, keep it warm for 2 - 2.5 h, and then cool it to room temperature to obtain the functional silane - modified polyurethane prepolymer.

[0052] Add 20 g of the prepared functional silane - modified polyurethane prepolymer in accordance with the amount and cure it with 9 g of chain extender NH1420 to obtain the functional silane - modified polyurethane antifouling coating.

[0053] Example 4

[0054] This example provides a functional silane - modified polyurethane antifouling coating, which is composed of component A and component B;

[0055] Component A contains 500 parts of the functional silane - modified polyurethane prepolymer prepared in Example 1, 80 parts of bentonite, 100 parts of titanium dioxide, 200 parts of zinc oxide, and 20 parts of talc powder. Add the above raw materials into a high - speed disperser and disperse them at high speed for 45 min to obtain component A.

[0056] Component B contains 5 parts of leveling agent, 5 parts of defoaming agent, 180 parts of the chain extender in Example 1, 10 parts of silane coupling agent, 2 parts of catalyst, and 98 parts of diluent.

[0057] When in use, mix component A and component B evenly according to the mass ratio of 3:1 and cure them by standing at room temperature.

[0058] Test 1:

[0059] Immerse the cured antifouling coatings of Example 1 and Example 3 and the blank sample in Amphora sp. After 1 day, the diatom inhibition rates compared with the blank sample are 96% and 62% respectively. After 7 days, the diatom inhibition rates compared with the blank sample are 86% and 57% respectively.

[0060] Test 2:

[0061] Immerse the cured antifouling coatings of Example 1 and Example 3 and the blank sample in Nitzschia closterium. After 7 days, the diatom inhibition rates compared with the blank sample are 88% and 63% respectively. After 14 days, the diatom inhibition rates compared with the blank sample are 83% and 57% respectively.

[0062] Test 3:

[0063] The solidified antifouling coating of Example 2 and the blank sample were immersed in Nitzschia closterium. On the 7th day, the diatom inhibition rate of the blank sample was 70% respectively.

[0064] Test 4:

[0065] The inhibition rates of the solidified antifouling coating of Example 1 against Escherichia coli and Staphylococcus aureus were 70% and 68% respectively. The inhibition rates of the solidified Example 3 against Escherichia coli and Staphylococcus aureus were 52% and 71% respectively.

[0066] Test 5:

[0067] The surface energy of the solidified antifouling coating of Example 1 was 26 mJ / m 2 .

[0068] Test 6:

[0069] The adhesion forces of the solidified antifouling coatings of Example 1, Example 2, and Example 3 to the Q235 steel plate were 2.5 MPa, 2.3 MPa, and 1.8 MPa respectively, showing good substrate adhesion.

[0070] Test 7:

[0071] After 5 months of exposure in the actual sea on the hanging panel test, it was observed that the adhesion of fouling organisms on the surface of the antifouling coating of Example 4 was significantly less, indicating excellent antifouling ability.

[0072] Compared with Examples 1 - 3, Example 4 added other components or additives such as bentonite, titanium dioxide, zinc oxide, and talc powder, which could overall improve the mechanical strength of the antifouling coating.

[0073] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included within the protection scope of the present invention.

Claims

1. A functional silane-modified polyurethane antifouling coating, characterized in that: It consists of component A and component B, wherein component A includes functional silane-modified polyurethane prepolymer, component B includes chain extender, and the weight ratio of functional silane-modified polyurethane prepolymer to chain extender is 1:0.01-0.6; the chain extender is a liquid amine chain extender; The functional silane-modified polyurethane prepolymer is prepared by the following steps: S1. Add the dehydrated epoxy-terminated polydimethylsiloxane and the amino-containing antifouling active ingredient into a four-necked flask equipped with a mechanical stirring device, a thermometer, a constant pressure dropping funnel and a condenser, add N,N-dimethylformamide and ethyl acetate to mix the reactants evenly, then heat to 80-100°C, and keep warm for 6-12 hours until the system is clear and the solid disappears, to obtain a functional silane; the amino-containing antifouling active ingredient is an active amino group that can react with an epoxy group, and the amino-containing antifouling active ingredient is one or more of thiazole and its derivatives; S2. Add dehydrated polyether polyol and functional silane at room temperature, heat the system to 50-60°C and drop isocyanate therein, mix well and heat the system to 80-85°C, keep warm for 2-2.5h and then cool to room temperature.

2. The functional silane-modified polyurethane antifouling coating according to claim 1, characterized in that: The molecular structure of the epoxy-terminated polydimethylsiloxane is as follows: , where R is or ; The repeating segment n is 1-38.

3. The functional silane-modified polyurethane antifouling coating according to claim 1, characterized in that: It consists of component A and component B; both are calculated by weight, and component A is mainly composed of the following raw materials: 500 parts of functional silane modified polyurethane prepolymer, 30-80 parts of bentonite, 50-100 parts of titanium dioxide, 100-250 parts of zinc oxide, and 10-30 parts of talc; Component B is mainly composed of the following raw materials: 3-5 parts of leveling agent, 3-5 parts of defoaming agent, 50-300 parts of chain extender, 6-30 parts of silane coupling agent, 1-2 parts of catalyst, and 50-150 parts of diluent.

4. The functional silane-modified polyurethane antifouling coating according to claim 3, characterized in that: The silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, bis-(γ-trimethoxysilylpropyl)amine, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, N-butyl-γ-aminopropyltrimethoxysilane, and N-butyl-γ-aminopropyltriethoxysilane.

5. The functional silane-modified polyurethane antifouling coating according to claim 3, characterized in that: The catalyst is one or more of dibutyltin dilaurate and dibutyltin diacetate.

6. A method for preparing the functional silane-modified polyurethane antifouling coating according to claim 3, characterized in that: The steps include: S1. Add the raw materials of component A into a high-speed disperser and disperse at high speed for 15-45 minutes to obtain component A; S2. Add the raw materials of component B into a high-speed disperser and disperse at high speed for 15-25 minutes to obtain component B.

7. Use of the functional silane-modified polyurethane antifouling coating according to claim 3 on ships and coastal facilities.

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