Self-release type low-surface-energy antifouling paint and preparation method thereof

Abstract

The invention belongs to the technical field of antifouling coatings, and discloses a self-release type low-surface-energy antifouling coating and a preparation method thereof. The antifouling paint comprises the following components: an organic silicon resin composition with an active terminal group, a chain extender, a cross-linking agent, a catalyst, an antifouling liquid and a nano filler, the organic silicon resin composition with active end groups comprises at least two organic silicon resins with active end groups and different molecular weights. The surface energy of the antifouling paint is not higher than 25mN / m, so that the antifouling paint is not easy to be attached by organisms; the anti-fouling liquid can be automatically and slowly released to the surface of the coating, so that the long-acting anti-fouling effect is achieved; the mechanical property is better.

Description

Technical Field

[0001] The invention belongs to the technical field of antifouling coatings, and more specifically, relates to a self-releasing low surface energy antifouling coating and a preparation method thereof. Background Art

[0002] Antifouling coatings have the function of preventing pollutants from attaching and accumulating, and are applied to various surfaces, such as buildings, cars, ships, equipment and pipelines. At present, they are commonly applied to the bottom of ships and underwater marine facilities. Through the seepage, diffusion or hydrolysis of the antifouling agent in the paint film, the purpose of preventing marine organisms from attaching to the bottom of ships or underwater marine facilities is achieved. With the increasing attention to marine safety and the need to protect aquatic organisms in freshwater environments, it is necessary to develop long-lasting and safe antifouling coatings.

[0003] Commonly used antifouling coatings that do not contain toxic antifouling agents include low surface energy antifouling coatings and self-polishing antifouling coatings. The former has the problem of insufficient strength and easy breakage, while the latter has the problem of self-degradation and being environmentally unfriendly. Both cannot achieve the goal of long-term safety.

[0004] Therefore, it is urgent to propose a new self-releasing low surface energy antifouling coating and a preparation method thereof. Summary of the invention

[0005] The purpose of the present invention is to address the deficiencies of the prior art and to propose a self-releasing low surface energy antifouling coating and a preparation method thereof. The surface energy of the antifouling coating of the present invention is not higher than 25 mN / m, and it is not easy for biological attachment; the antifouling liquid can be released slowly and autonomously to the coating surface to achieve a long-term antifouling effect; and the mechanical properties are better.

[0006] In order to achieve the above object, the present invention provides a self-releasing low surface energy antifouling coating, which comprises the following components: an organic silicone resin composition with active end groups, a chain extender, a crosslinking agent, a catalyst, an antifouling liquid and a nanofiller;

[0007] The terminal-active organic silicone resin composition comprises at least two terminal-active organic silicone resins with different molecular weights.

[0008] According to the present invention, preferably, the surface energy of the antifouling coating is not higher than 25 mN / m.

[0009] In the present invention, the organic silicone resin with active terminal groups is curable. According to the present invention, preferably, the organic silicone resin with active terminal groups is a hydroxyl-terminated organic silicone resin and / or an alkoxy-terminated organic silicone resin.

[0010] According to the present invention, preferably, the organic silicone resin with active terminal groups is at least one of hydroxyl-terminated polydimethylsiloxane, methoxy-terminated polydimethylsiloxane and ethoxy-terminated polydimethylsiloxane.

[0011] According to the present invention, preferably, the molecular weight of the organic silicone resin with active terminal groups ranges from 5000 to 80000 g / mol;

[0012] The viscosity of the organic silicon resin with active terminal groups ranges from 100 to 10000 cst.

[0013] According to the present invention, preferably, the terminal-active organic silicone resin composition comprises two terminal-active organic silicone resins with different molecular weights, wherein the mass ratio of the relatively high molecular weight terminal-active organic silicone resin to the relatively low molecular weight terminal-active organic silicone resin is (5-95): (95-5).

[0014] According to the present invention, preferably, the chain extender is at least one of N,N-dimethyltrimethylsilylamine, methyltributylidene oxime silane, vinyltributylidene oxime silane, tetramethylethyloxime silane and ethyltriacetoxysilane.

[0015] According to the present invention, preferably, the crosslinking agent is at least one of hydroxyl-terminated siloxane, amino-terminated siloxane and epoxy-terminated siloxane.

[0016] According to the present invention, preferably, the catalyst is an organic acid catalyst and / or an organic base catalyst.

[0017] According to the present invention, preferably, the antifouling liquid is at least one of methylphenyl silicone oil, diphenyl silicone oil, polyethylene glycol-modified silicone oil and amino silicone oil.

[0018] According to the present invention, preferably, the nano filler is at least one of hydrophobic fumed silica, hydrophilic fumed silica, nano zinc oxide and nano titanium dioxide.

[0019] According to the present invention, preferably, the added amounts of the chain extender, crosslinker, catalyst, antifouling liquid and nanofiller are 10-30%, 1-5%, 0.1-2%, 30-100% and 5-50% of the added amount of the end-group active silicone resin composition, respectively.

[0020] Another aspect of the present invention provides a method for preparing the self-releasing low surface energy antifouling coating, the method comprising the following steps:

[0021] S1: under a nitrogen atmosphere, mixing and stirring the organic silicone resin composition having active terminal groups and the antifouling liquid to obtain a first mixture;

[0022] S2: under a nitrogen atmosphere, mixing and stirring the first mixture with the dried nanofiller to obtain a second mixture;

[0023] S3: mixing and stirring the second mixture and the chain extender under vacuum to negative pressure to obtain a third mixture;

[0024] S4: mixing and stirring the third mixture with the cross-linking agent and the catalyst under normal pressure, and sealing and packaging to obtain the self-releasing low surface energy antifouling coating.

[0025] According to the present invention, preferably, in step S1, the stirring time is 10-30 min, and the stirring speed is 100-500 rpm.

[0026] According to the present invention, preferably, in step S2, the stirring time is 20-50 min, and the stirring speed is 300-800 rpm.

[0027] According to the present invention, preferably, in step S3, the stirring time is 20-40 min, the stirring speed is 100-500 rpm, and the negative pressure is -0.08 MPa to -0.1 MPa.

[0028] According to the present invention, preferably, in step S4, the stirring time is 10-30 min, and the stirring speed is 100-500 rpm.

[0029] The beneficial effects of the technical solution of the present invention are as follows:

[0030] (1) The main raw materials used in the antifouling coating of the present invention (the organic silicon resin composition with active end groups, the chain extender, the crosslinking agent, and the antifouling liquid) are all organic silicon materials, which are more hydrophobic after crosslinking, thereby obtaining an antifouling coating with lower surface energy, whose surface energy is not higher than 25 mN / m, and aquatic organisms are not easy to attach; the antifouling coating of the present invention is green and environmentally friendly, does not contain toxic antifouling agents, and is harmless to aquatic organisms.

[0031] (2) The antifouling coating of the present invention has better mechanical properties and is not easy to break. The chain extender reacts with water in the air to form terminal hydroxyl groups, which then react and condense with the terminal active silicone resin to form a branched product with a higher molecular weight. The crosslinking agent reacts with the remaining terminal hydroxyl groups in the multiple branched products to form a crosslinked structure with a certain strength. The O and N groups on the structure are combined with the surface of the nanofiller through hydrogen bonding force, and finally form a network reinforcement structure.

[0032] (3) The antifouling coating of the present invention releases the antifouling liquid at a controllable speed and slowly seeps out over a long period of time, thereby ensuring the long-term antifouling effect. The nano-reinforced filler absorbs the antifouling liquid, and the network reinforcement structure plays a storage role. The organic silicone resin with active end groups of different molecular weights is matched with the chain extender and the cross-linking agent to adjust the density of the network structure, thereby controlling the seepage speed of the antifouling liquid.

[0033] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings.

[0035] Figure 1 A diagram showing a mussel attachment test of a test example of the present invention is shown. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0037] In the following examples and comparative examples, the CAS numbers of the raw materials used are:

[0038] Ethoxylated polydimethylsiloxane 70851-25-1;

[0039] Hydroxyl-terminated polydimethylsiloxane 70131-67-8;

[0040] Methoxy-terminated polydimethylsiloxane 68951-97-3;

[0041] Hydroxyl-terminated siloxanes 156327-07-0, 68952-02-3, 63148-60-7;

[0042] Amino-terminated siloxane 97917-34-5, 99904-16-2, 481668-57-9;

[0043] Epoxy-terminated siloxanes 102782-98-9, 68440-71-1, 127947-26-6;

[0044] Organic base catalysts 865-47-4, 6674-22-2, 10424-65-4;

[0045] Organic acid catalysts 10519-96-7, 625-45-6, 4325-85-3;

[0046] Hydrophobic fumed silica 112945-52-5;

[0047] Hydrophilic fumed silica 112945-52-5.

[0048] Example 1

[0049] This embodiment provides a self-releasing low surface energy antifouling coating, the antifouling coating comprising the following components:

[0050] An organic silicone resin composition with active terminal groups (200 g of ethoxylated polydimethylsiloxane with a molecular weight of 6000 g / mol and 300 g of ethoxylated polydimethylsiloxane with a molecular weight of 70000 g / mol),

[0051] Chain extender (ethyl triacetoxysilane 150g),

[0052] Crosslinking agent (22 g of epoxy-terminated siloxane),

[0053] Catalyst (organic base catalyst 9g),

[0054] Antifouling liquid (polyethylene glycol modified silicone oil 100g, amino silicone oil 60g),

[0055] Dried nano filler (nano zinc oxide 100 g, nano titanium dioxide 120 g);

[0056] The preparation method of the self-releasing low surface energy antifouling coating of this embodiment comprises the following steps:

[0057] S1: In a nitrogen atmosphere, the organic silicone resin composition with active terminal groups and the antifouling liquid are mixed and stirred in a closed dispersion tank for 10 minutes at a stirring speed of 400 rpm to obtain a first mixture;

[0058] S2: slowly adding the dried nanofiller, and mixing the first mixture with the dried nanofiller at a stirring speed of 700 rpm for 25 minutes under a nitrogen atmosphere to obtain a second mixture;

[0059] S3: mixing and stirring the second mixture and the chain extender under vacuum to -0.08 MPa to -0.1 MPa at a stirring speed of 150 rpm for 25 min to obtain a third mixture;

[0060] S4: the third mixture is continuously mixed and stirred with the cross-linking agent and the catalyst under normal pressure for 28 minutes, and the mixture is sealed and packaged to obtain the self-releasing low surface energy antifouling coating.

[0061] Example 2

[0062] This embodiment provides a self-releasing low surface energy antifouling coating, the antifouling coating comprising the following components:

[0063] An organic silicone resin composition with active terminal groups (400 g of hydroxyl-terminated polydimethylsiloxane with a molecular weight of 10,000 g / mol, 100 g of hydroxyl-terminated polydimethylsiloxane with a molecular weight of 40,000 g / mol),

[0064] Chain extender (N,N-dimethyltrimethylsilane 35g, tetramethylethyloxime silane 70g),

[0065] Crosslinking agent (amino-terminated siloxane 6g),

[0066] Catalyst (organic base catalyst 0.6g),

[0067] Antifouling liquid (methylphenyl silicone oil 350g, diphenyl silicone oil 150g),

[0068] Dried nanofiller (20 g of hydrophobic fumed silica and 10 g of hydrophilic fumed silica);

[0069] The preparation method of the self-releasing low surface energy antifouling coating of this embodiment comprises the following steps:

[0070] S1: Under a nitrogen atmosphere, the organic silicone resin composition with active terminal groups and the antifouling liquid are mixed and stirred in a closed dispersion tank for 26 minutes at a stirring speed of 150 rpm to obtain a first mixture;

[0071] S2: slowly adding the dried nanofiller, and mixing the first mixture with the dried nanofiller at a stirring speed of 300 rpm for 50 minutes under a nitrogen atmosphere to obtain a second mixture;

[0072] S3: mixing and stirring the second mixture and the chain extender under vacuum to -0.08 MPa to -0.1 MPa at a stirring speed of 200 rpm for 30 min to obtain a third mixture;

[0073] S4: the third mixture is continuously mixed and stirred with the cross-linking agent and the catalyst under normal pressure for 18 minutes, and the mixture is sealed and packaged to obtain the self-releasing low surface energy antifouling coating.

[0074] Example 3

[0075] This embodiment provides a self-releasing low surface energy antifouling coating, the antifouling coating comprising the following components:

[0076] An organic silicone resin composition with active terminal groups (140 g of methoxy-terminated polydimethylsiloxane with a molecular weight of 7000 g / mol and 360 g of methoxy-terminated polydimethylsiloxane with a molecular weight of 50000 g / mol),

[0077] Chain extender (methyl tributylacetoximate silane 20g, vinyl tributylacetoximate silane 30g),

[0078] Crosslinking agent (15 g of terminal hydroxyl siloxane),

[0079] Catalyst (organic acid catalyst 5g),

[0080] Antifouling liquid (methylphenyl silicone oil 160g, polyethylene glycol modified silicone oil 90g), dried nano filler (hydrophobic fumed silica 15g, nano zinc oxide 65g);

[0081] The preparation method of the self-releasing low surface energy antifouling coating of this embodiment comprises the following steps:

[0082] S1: In a nitrogen atmosphere, the organic silicone resin composition with active terminal groups and the antifouling liquid are mixed and stirred in a closed dispersion tank for 20 minutes at a stirring speed of 500 rpm to obtain a first mixture;

[0083] S2: slowly adding the dried nanofiller, and mixing the first mixture with the dried nanofiller at a stirring speed of 500 rpm for 30 minutes under a nitrogen atmosphere to obtain a second mixture;

[0084] S3: mixing and stirring the second mixture and the chain extender under vacuum to -0.08 MPa to -0.1 MPa at a stirring speed of 400 rpm for 20 min to obtain a third mixture;

[0085] S4: the third mixture is continuously mixed and stirred with the cross-linking agent and the catalyst under normal pressure for 18 minutes, and the mixture is sealed and packaged to obtain the self-releasing low surface energy antifouling coating.

[0086] Example 4

[0087] This embodiment provides a self-releasing low surface energy antifouling coating, the antifouling coating comprising the following components:

[0088] An organic silicone resin composition with active terminal groups (50 g of methoxy-terminated polydimethylsiloxane with a molecular weight of 15,000 g / mol, 450 g of hydroxy-terminated polydimethylsiloxane with a molecular weight of 30,000 g / mol),

[0089] Chain extender (vinyl trisbutyl ketoxime silane 80g),

[0090] Crosslinking agent (13 g hydroxyl-terminated siloxane, 7 g epoxy-terminated siloxane),

[0091] Catalyst (organic acid catalyst 7g),

[0092] Antifouling liquid (diphenyl silicone oil 220g, amino silicone oil 130g),

[0093] Dried nanofiller (15 g of hydrophobic fumed silica and 135 g of nano titanium dioxide);

[0094] The preparation method of the self-releasing low surface energy antifouling coating of this embodiment comprises the following steps:

[0095] S1: In a nitrogen atmosphere, the organic silicone resin composition with active terminal groups and the antifouling liquid are mixed and stirred in a closed dispersion tank for 15 minutes at a stirring speed of 200 rpm to obtain a first mixture;

[0096] S2: slowly adding the dried nanofiller, and mixing the first mixture with the dried nanofiller at a stirring speed of 400 rpm for 42 minutes under a nitrogen atmosphere to obtain a second mixture;

[0097] S3: mixing and stirring the second mixture and the chain extender under vacuum to -0.08 MPa to -0.1 MPa at a stirring speed of 310 rpm for 33 min to obtain a third mixture;

[0098] S4: the third mixture is continuously mixed and stirred with the cross-linking agent and the catalyst at normal pressure for 25 minutes, and the mixture is sealed and packaged to obtain the self-releasing low surface energy antifouling coating.

[0099] Comparative Example 1

[0100] The only difference between this comparative example and Example 3 is that no cross-linking agent is added in this comparative example.

[0101] Comparative Example 2

[0102] The difference between this comparative example and Example 3 is that the organic silicone resin composition with active terminal groups in this comparative example contains only 500 g of terminal methoxy polydimethylsiloxane with a molecular weight of 7000 g / mol.

[0103] Comparative Example 3

[0104] The difference between this comparative example and Example 3 is that the organic silicone resin composition with active terminal groups in this comparative example contains only 500 g of terminal methoxy polydimethylsiloxane with a molecular weight of 50,000 g / mol.

[0105] Comparative Example 4

[0106] The difference between this comparative example and Example 3 is only that:

[0107] In step S3 of the method for preparing the antifouling coating, the second mixture and the chain extender are mixed and stirred under a nitrogen atmosphere at a stirring speed of 400 rpm for 20 minutes to obtain a third mixture without vacuuming.

[0108] The rest is the same as Example 3.

[0109] Comparative Example 5

[0110] The only difference between this comparative example and Example 3 is that no antifouling liquid is added in this comparative example.

[0111] Test Case

[0112] This test example tests the antifouling coatings obtained from the above embodiments and comparative examples.

[0113] The bonding strength and tensile strength are tested in accordance with GBT 16777-2008 Test Methods for Building Waterproof Coatings;

[0114] Mussel attachment rate: Select adult mussels with a body length of 15-25 mm and fix them on the surface of the antifouling paint with rubber bands (see Figure 1 ), after being placed in the test pool for 7 days, the number of mussels attached was observed. The number of mussels attached to the coating surface with good antifouling performance was less, and the mussel attachment rate = the final number of attached mussels / the initial number of mussels.

[0115] The test results are shown in Table 1.

[0116] Table 1

[0117]

[0118]

[0119] As shown in Table 1, compared with Comparative Examples 1-5, Examples 1-4 have higher mechanical properties and better antifouling properties (no mussels attached). Although Comparative Examples 1-5 use the same silicone resin, chain extender, crosslinker, catalyst, antifouling liquid, and nanofiller as Example 3, they lack the coordination of crosslinker and antifouling liquid and silicone resins of different molecular weights, and the reaction is not in a negative pressure environment, and a stable network reinforcement structure cannot be formed to store and slowly release the antifouling liquid while maintaining its own mechanical properties. Therefore, the effects consistent with the present invention cannot be obtained.

[0120] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A self-releasing low surface energy antifouling coating, characterized in that: The antifouling coating comprises the following components: an organic silicon resin composition with active terminal groups, a chain extender, a crosslinking agent, a catalyst, an antifouling liquid and a nano filler; The terminal-active organic silicone resin composition comprises at least two terminal-active organic silicone resins with different molecular weights.

2. The self-releasing low surface energy antifouling coating according to claim 1, wherein: The surface energy of the antifouling coating is not higher than 25 mN / m.

3. The self-releasing low surface energy antifouling coating according to claim 1, wherein: The organic silicon resin with active terminal groups is a hydroxyl-terminated organic silicon resin and / or an alkoxy-terminated organic silicon resin.

4. The self-releasing low surface energy antifouling coating according to claim 3, wherein: The organic silicone resin with active terminal groups is at least one of hydroxyl-terminated polydimethylsiloxane, methoxy-terminated polydimethylsiloxane and ethoxy-terminated polydimethylsiloxane.

5. The self-releasing low surface energy antifouling coating according to claim 1, 3 or 4, wherein: The molecular weight of the organic silicone resin with active terminal groups ranges from 5000 to 80000 g / mol; The viscosity of the organic silicone resin with active terminal groups ranges from 100 to 10000 cst.

6. The self-releasing low surface energy antifouling coating according to claim 5, wherein: The terminal-active organic silicone resin composition comprises two terminal-active organic silicone resins with different molecular weights, wherein the mass ratio of the terminal-active organic silicone resin with a relatively high molecular weight to the terminal-active organic silicone resin with a relatively low molecular weight is (5-95):(95-5).

7. The self-releasing low surface energy antifouling coating according to claim 1, wherein: The chain extender is at least one of N,N-dimethyltrimethylsilylamine, methyltributylidene oxime silane, vinyltributylidene oxime silane, tetramethylethyloxime silane and ethyltriacetoxysilane; The crosslinking agent is at least one of hydroxyl-terminated siloxane, amino-terminated siloxane and epoxy-terminated siloxane; The catalyst is an organic acid catalyst and / or an organic base catalyst; The antifouling liquid is at least one of methylphenyl silicone oil, diphenyl silicone oil, polyethylene glycol-modified silicone oil and amino silicone oil; The nano filler is at least one of hydrophobic fumed silica, hydrophilic fumed silica, nano zinc oxide and nano titanium dioxide.

8. The self-releasing low surface energy antifouling coating according to claim 1, wherein: The added amounts of the chain extender, crosslinking agent, catalyst, antifouling liquid and nano filler are 10-30%, 1-5%, 0.1-2%, 30-100% and 5-50% of the added amount of the organic silicon resin composition with active terminal groups respectively.

9. The method for preparing the self-releasing low surface energy antifouling coating according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: S1: under a nitrogen atmosphere, mixing and stirring the organic silicone resin composition having active terminal groups and the antifouling liquid to obtain a first mixture; S2: under a nitrogen atmosphere, mixing and stirring the first mixture with the dried nanofiller to obtain a second mixture; S3: mixing and stirring the second mixture and the chain extender under vacuum to negative pressure to obtain a third mixture; S4: mixing and stirring the third mixture with the cross-linking agent and the catalyst under normal pressure, and sealing and packaging to obtain the self-releasing low surface energy antifouling coating.

10. The method for preparing the self-releasing low surface energy antifouling coating according to claim 9, wherein: In step S1, the stirring time is 10-30 min, and the stirring speed is 100-500 rpm; In step S2, the stirring time is 20-50 min, and the stirring speed is 300-800 rpm; In step S3, the stirring time is 20-40 min, the stirring speed is 100-500 rpm, and the negative pressure is -0.08 MPa to -0.1 MPa; In step S4, the stirring time is 10-30 min, and the stirring speed is 100-500 rpm.

Images