An antifouling agent, a micro-nano mesoporous material, and a marine antifouling composition

Abstract

The present invention discloses an antifouling agent, a micro-nano mesoporous material and a marine antifouling composition. The preparation method of the micro-nano mesoporous material includes: S1. Hydrothermally acid-etching, cleaning and calcining the micro-nano mesoporous material matrix in sequence, and cooling for standby; S2. Dissolving the DCOIT-like derivative and the haloaliphatic alcohol in a solvent, heating under reflux and then dropping a mixed solution of diisocyanate and a catalyst, and continuing the heat preservation reaction; S3. Grinding and swelling the modified matrix of the micro-nano mesoporous material prepared in S1 to fully loosen the agglomerated fiber bundles, then ultrasonically dispersing in a solvent, adding it into the system of S2 for heating reaction, and then storing after purification, drying and grinding. The present invention utilizes the activated silanol groups enriched in the modified matrix of the micro-nano mesoporous material to covalently link with the degradable terminal isocyanate (R-NCO) in the quaternized DCOIT-like derivative, and has the properties of high efficiency, broad spectrum, low toxicity and long effect.

Description

Technical Field

[0001] The present invention belongs to the field of organic-inorganic hybrid functional materials, and particularly relates to an antifouling agent, a micro-nano mesoporous material, and a marine antifouling composition. Background Art

[0002] The attachment and reproduction of marine organisms have a serious negative impact on marine engineering and national defense construction. It not only reduces the ship speed, significantly increases fuel consumption, but also may cause instability of facilities / platforms, and its acidic secretions will also exacerbate metal corrosion. How to effectively deal with marine biofouling has always been a global and century-old problem. Among many protection measures, coating antifouling paints is undoubtedly one of the most economical and convenient ideal means.

[0003] The key component of an antifouling paint is the antifouling agent system, which should have characteristics such as low toxicity, high efficiency, broad spectrum, and long-term effectiveness, so as to efficiently kill as many adherent biological populations as possible without damaging the marine ecosystem, and at the same time be able to act continuously for a long time.

[0004] Tributyltin (TBT) was once widely used worldwide due to its excellent antifouling ability. However, it was later found that tin elements can disrupt the biological endocrine system, and the metabolite toxicity is as high as 100 - 400 μg / L. Since 2008, it has been completely prohibited by the International Maritime Organization. 4,5-Dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT), as the first green antifouling agent with the smallest bioaccumulation (half-life ≤ 1 h) and registered with the EU BPD (metabolite toxicity > 125 mg / L, acute oral LD D , 50 , D , 50 50 > 2800 mg / kg for rats, acute percutaneous LD D 50 > 5000 mg / kg for rabbits), has incomparable environmental protection and universality with TBT, and can well inhibit and kill the attachment and growth of fungi (such as molds, yeasts), bacteria, algae, mucus, seagrass, sea anemones, tunicates, sponges (so-called "soft fouling organisms"), as well as hard-shelled invertebrates such as barnacles and tube worms ("hard fouling organisms"). DCOIT and its derivatives are regarded as the best choice for current general marine antifouling agents in the industry. In order to obtain long-term antifouling efficacy, researchers have spared no effort to transform it into a sustained-release system through various ways.

[0005] Patents with the following publication numbers, namely CN102293198B, CN101137288B, KR101253065B1, JP2008513475A, and WO2006032019A1, use DCOIT as the core material and develop oil-in-water core-shell structure microcapsules through multiple processes. These microcapsules have good sustained-release properties, and their release amount is less than 10% after being soaked in xylene for 90 days. Zhou Yaoru (Fine and Specialty Chemicals, 2024, 32(2): 39-44) also synthesized DCOIT@HACC-SA (quaternary ammonium salt chitosan-sodium alginate) microcapsules, but the initial exudation was too fast (75.4% burst release within 12 days), making it difficult to meet the long-term anti-fouling requirements in the ocean.

[0006] In addition to microencapsulation, physically adsorbing DCOIT onto the surface layer and / or internal pores of micro-nano particles with high specific surface area through intermolecular hydrogen bonds, van der Waals forces, electrostatic coupling, etc. is also a kind of conventional operation. Wang Xiaowei (Fine Chemicals, 2007, 24(10): 944-947; 2007, 24(3): 213-220) embedded DCOIT with copper microspheres and nano-titanate tubes respectively, but the drug loading amounts were both low, with the maximum being only 15.2% and 12%. Patents with the following publication numbers, namely US6676954B2 and CN1229022C, disclosed a controlled-release composition. The DCOIT anti-fouling coating adsorbed by different activated carbons released 53% in artificial seawater in 21 days (C-1 carbon type) or only needed 30 days to release 50% (C-2 carbon type), which is also only suitable for short-term anti-fouling.

[0007] The patent with the publication number CN115141508B provides a long-acting metal-organic framework loaded anti-fouling agent and its preparation method, relying on the mutual cooperation between BIT-NH 2 quaternary ammonium salt and UiO-66-COOH framework. The sustained-release effect of BIT in artificial seawater is obvious. It takes 45 days and 47 days respectively to release 50% at the loadings of 39.75% and 40.51%. Similarly, Zhang Xin (Surface Technology, 2024, 53(8): 107-118) successfully encapsulated carboxylated 1,2-benzisothiazolin-3-one (BIT-COOH) into amino ZIF-7 (NH 2 -ZIF-7) nano-cages by the impregnation method, with stable sustained release and excellent antibacterial / algal properties.

[0008] The patent with the publication number CN110835495B provides a moisture-curing polyurethane anti-fouling coating for fishing nets and its preparation method. The linear hydroxyl-terminated polycaprolactone resin is aminated with diisocyanate and crosslinked by water vapor. The paint film can meet the flexibility requirements of fishing nets. However, the selected porous fillers such as diatomite, sepiolite, and calcined kaolin have not been modified such as for expansion, and only simple adsorption is carried out on the biocides bromopyronitrile and DCOIT, and the drug loading amount is unknown.

[0009] Generally speaking, microencapsulation and physical adsorption each have their own advantages and disadvantages in the controlled-release performance. The drug loading capacity of microcapsules can be adjusted by the size of the capsule diameter, but the preparation process is relatively complex. In addition, both the simple oil-in-water or water-in-oil configurations may be swollen by organic solvents or seawater in the antifouling coating, resulting in capsule adhesion and capsule wall rupture, causing excessive and rapid dissolution of the antifouling agent core. The intermolecular force of physical adsorption is weak, and the antifouling agent is easily desorbed (detached from the carrier). In addition, the pores of natural porous materials (such as carbon nanotubes, halloysite, montmorillonite, zeolite, etc.) are narrow, mostly belonging to mesopores (2-50 nm), and the volume is limited. The compatibility difference between the inorganic powder and the organic film-forming resin of the antifouling coating also makes the antifouling agent embedding system prone to sedimentation and segregation. Summary of the Invention

[0010] Based on the above defects, the object of the present invention is to disclose an antifouling agent, a micro-nano mesoporous material and a marine antifouling composition. The micro-nano mesoporous material matrix is expanded by hydrothermal acid etching, and the enriched activated silicon hydroxyl groups are covalently linked to the degradable terminal isocyanate (R-NCO) in the quaternized DCOIT derivative. The organic antifouling agent guest molecules are firmly locked in the modified micro-nano mesoporous material matrix through strong chemical bonds, which is green and environmentally friendly and has long-term and slow-release antifouling performance.

[0011] To achieve the above object, the technical solution of the present invention is as follows:

[0012] An antifouling agent, the structure is as general formula I:

[0013] ;

[0014] In formula I, m and n are non-zero natural numbers respectively, and X is a halogen.

[0015] The present invention also discloses a micro-nano mesoporous material, including a micro-nano mesoporous material matrix and the antifouling agent, and the activated silicon hydroxyl groups in the micro-nano mesoporous material matrix are covalently connected to the -NCO units in the antifouling agent.

[0016] The micro-nano mesoporous material refers to an inorganic, organic or organic-inorganic hybrid material with a pore diameter between 2 and 50 nm, having a high specific surface area (BET≥150m 2 / g), good adsorption / catalytic activity and complex pore structure.

[0017] The antifouling agent is prepared by reacting a DCOIT derivative, a halogenated fatty alcohol and a diisocyanate.

[0018] In a preferred embodiment of the present invention, the micro-nano mesoporous material matrix includes one or more of sepiolite, halloysite, montmorillonite, zeolite, fumed silica and metal-organic frameworks.

[0019] In a preferred embodiment of the present invention, the micro-nano mesoporous material matrix is sepiolite, and the structure of the micro-nano mesoporous material is as Figure 1 shown.

[0020] Figure 1 In Figure 1 , the hollow tube represents the sepiolite porous fiber 1, and the black curve represents the antifouling agent long chain 2 chemically loaded on the surface and inside of the sepiolite.

[0021] In a preferred embodiment of the present invention, when the micro-nano mesoporous material matrix is sepiolite, the particle size of the micro-nano mesoporous material matrix is 200 - 3000 mesh. The particle size of the micro-nano mesoporous material matrix is preferably 800 - 2000 mesh. Within this particle size range, the sepiolite fiber has regular morphology, good adjustability of drug loading amount, and high matching degree with the antifouling composition.

[0022] In a preferred embodiment of the present invention, the preparation method of the micro-nano mesoporous material comprises the following steps: S1. The micro-nano mesoporous material matrix is successively subjected to hydrothermal acid etching, washing, roasting, and then cooled for standby; S2. The DCOIT-like derivative and the haloaliphatic alcohol are dissolved in a solvent, heated under reflux, and then a mixed solution of diisocyanate and a catalyst is added dropwise, and the reaction is continued under insulation; S3. The modified matrix of the micro-nano mesoporous material obtained in S1 is ground, dispersed in a solvent, added to the system of S2, heated for reaction, and then purified, dried, and ground for storage.

[0023] In a preferred embodiment of the present invention, in step S1, the acid etching is carried out with 8 - 10 wt% dilute hydrochloric acid. Preferably, the micro-nano mesoporous material matrix is dispersed in the dilute hydrochloric acid to form a suspension with a solid content of 3 - 5 wt%, and magnetically stirred at 50 - 60 °C for 10 - 12 h; the roasting temperature is 200 - 300 °C, and the roasting time is 1 - 2 h; in the washing step, it is washed with a saturated NaHCO 3 solution until neutral.

[0024] In S2, the molar ratio of the DCOIT-like derivative, the haloaliphatic alcohol, and the diisocyanate is 1:(1 - 1.1):(1.1 - 1.15). Preferably, the DCOIT-like derivative, the haloaliphatic alcohol, the diisocyanate, and the solvent are all pre-dried to remove water, and the reaction is protected by an N 2 atmosphere and continuously stirred throughout the process; more preferably, a quaternization catalyst is further added in S2, including one or a combination of two of NaI and KI, and the molar mass ratio of the DCOIT-like derivative to the quaternization catalyst is 40 - 60 mmol:(40 - 60) mg.

[0025] Preferably, in S2, the reflux temperature is 40 - 50 °C, the reflux time is 10 - 12 h, and the subsequent insulation time is 6 - 8 h.

[0026] Preferably, in S3, the heating temperature is 60 - 70 °C, and the reaction time is 5 - 6 h.

[0027] In a preferred embodiment of the present invention, the structure of the DCOIT-like derivative is represented by the general formula II:

[0028] ;

[0029] In formula II, R 1 and R 2 are each independently selected from -H, -Cl, -Br, -I; R 3 is selected from any one of -H, alkyllipids, aralkyl, alkoxy, alkenyl, alkynyl. Preferably, R 1 and R 2 are both -Cl, and R 3 is -C 8 H 17 .

[0030] The DCOIT-like derivatives include DCOIT and its derivatives.

[0031] DCOIT and its derivatives have extremely strong penetrability to biological cell membranes and cell walls, and can interact with sulfur-containing proteins, enzymes or active small molecules in cells (the S-N bond is broken to form an S-S bond), thereby destroying the cell division and proliferation ability. By comparison, it is found that when there are relatively large substituents (such as benzene rings, long-chain alkyllipids) or electron-withdrawing groups (ether bonds, carbonyl groups) on the N atom, or when there are more halogen atoms on the isothiazolinone ring, their biological activity is relatively strong. Based on this and considering the market scale, price, etc. comprehensively, preferably, R 1 and R 2 are both -Cl, and R 3 is -C 8 H 17 .

[0032] In a preferred embodiment of the present invention, the halogenated fatty alcohol includes one or more of chloro-, bromo-, iodo-, and fatty alcohols with 1 to 8 carbon atoms;

[0033] The diisocyanate is an α, ω-terminal diisocyanato fatty acid ester and its derivatives, including one or more of 2,3-diisocyanatopropionate, 2,4-diisocyanatobutyrate, 2,5-diisocyanatovalerate, 2,6-diisocyanatohexanoate, 2,7-diisocyanatoheptanoate, 2,8-diisocyanatooctanoate, 2,9-diisocyanatononanoate, 2,10-diisocyanatodecanoate and their derivatives.

[0034] In view of factors such as the reaction activity, selling price, and ease of degradation of the halogenated substances, the halogenated fatty alcohol is preferably 6-bromo-1-hexanol; the diisocyanate is preferably one or a combination of two of ethyl 2,5-diisocyanatovalerate and ethyl 2,6-diisocyanatohexanoate.

[0035] Ethyl 2,5 - diisocyanate valerate and ethyl 2,6 - diisocyanate caproate are modified products of ornithine and lysine respectively. Both are green and renewable, can be purchased on the market, have a moderate molecular chain length and can be completely degraded. Other non - natural forms of diisocyanates, such as toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate units selected in the patent with publication number CN110835495B, are non - degradable and can ultimately only disintegrate into "microplastics" (the degradation described in this patent essentially only occurs in the polycaprolactone segment), and their environmental friendliness needs to be improved.

[0036] The solvents used in S2 and S3 are one or more of ethyl acetate, xylene, methanol, chloroform, acetonitrile, and butyl acetate.

[0037] The catalyst in S2 is one or two of diisobutyltin dilaurate and stannous octoate.

[0038] In S3, the modified matrix of the micro - nano mesoporous material obtained in S1 is ground and fluffed to fully loosen the agglomerated fiber bundles, and then ultrasonically dispersed in the solvent to facilitate the deep penetration of the solvent and reaction molecules into it.

[0039] The present invention also discloses a marine antifouling composition. By weight, it contains 10 - 30 parts of the micro - nano mesoporous material, and also contains 25 - 45 parts of cuprous oxide, 5 - 10 parts of zinc pyrithione, 30 - 40 parts of hyperbranched zinc resin, 3 - 5 parts of modified rosin, 1 - 3 parts of polyethylene wax, 0 - 3 parts of chlorinated paraffin, 0 - 10 parts of filler, 0 - 3 parts of iron oxide red, and 10 - 20 parts of organic solvent.

[0040] Preferably, in the marine antifouling composition, the filler is selected from one or more of talc powder, titanium dioxide powder, silica powder, and calcium carbonate powder; the organic solvent is a mixed solution of xylene and n - butanol in a mass ratio of (1 - 3):1.

[0041] Compared with the patent with publication number CN110835495B, in this scheme, the biocide physically adsorbs in the porous filler through weak interactions such as hydrogen bonds, and the terminal isocyanate - group polyester resin cures into a film by moisture curing. The formed paint film can be slowly hydrolyzed while releasing the antifouling agent in the coating. In the present invention, a covalent bond is formed between the modified matrix of the micro - nano mesoporous material and the DCOIT - like derivative through a carbamate reaction. The DCOIT - like derivative is a quaternized DCOIT - like derivative, so that the organic antifouling agent guest molecules are firmly encapsulated in the modified matrix of the micro - nano mesoporous material through strong chemical bonds, and the binding principle is completely different from that of the patent with publication number CN110835495B. In addition, the filler involved in the patent with publication number CN110835495B has not been expanded, and there is no chemical bonding between it and the biocide molecules, and its drug - loading capacity, actual drug - release stability, and long - term effectiveness (after 6 months) are unknown.

[0042] The preparation mechanism of the micro-nano mesoporous material is further explained as follows:

[0043] The matrix of the micro-nano mesoporous material represented by sepiolite has a large specific surface area and complex pores, and has high dispersibility in most solvents. It is a rare natural carrier. Unfortunately, the pore diameter is generally small and the pore volume is limited. While the hydrothermal acid etching treatment in step S1 further penetrates and expands the original cavity structure of sepiolite in the horizontal and vertical directions to increase the loading capacity, it can also remove impurities such as calcite and quartz, effectively reduce the density of the magnesium-rich silicate crystal, transform the fiber from the bundle state to the divergent state, and obtain more and more activated silanol groups (such as Mg in the "-Si-O-Mg-O-Si-" skeleton 2+ is replaced by H + to form a Si-O-H bond). The high-temperature calcination (<300 °C) not only helps to remove water molecules existing in various forms in the sepiolite lattice (such as adsorbed free water), avoiding the potential possibility of the termination of the -NCO chain reaction caused by the latter, but also can increase the specific surface area and pore diameter of the fiber. However, it should be noted that too high hydrochloric acid concentration (>15 wt%) is likely to cause serious fiber breakage; when the calcination temperature is >300 °C, the pore channels may collapse and the hydroxyl water is lost (meaning that it no longer has graftability), and even the crystal form is completely changed.

[0044] Research has confirmed that a large number of silanol groups on the surface and inside of sepiolite have strong affinity for organic matter (especially after acid etching activation), and can be polyurethaneized with the -NCO functional group; the N atom on the tertiary amine of the DCOIT-like derivative contains a lone pair of electrons and can be nucleophilically substituted by a halogen with stronger electronegativity. Based on this, after the DCOIT-like derivative is quaternized into a haloaliphatic alcoholate and a specific diisocyanate is introduced, it endows it with active sites that can covalently bond with the modified sepiolite, enabling the two to finally form a chemical loading method that is significantly different from physical coupling relying on intermolecular hydrogen bonds, electrostatic forces, etc.; subsequently, through the dual degradation of the amino acid ester and fatty alcohol units in the polyurethane chain segment, the antifouling agent is slowly released, and then the drug effect is exerted.

[0045] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0046] 1. By covalently linking the silicon hydroxyl groups that are abundant and activated in the modified sepiolite fibers with the terminal -NCO in the quaternary ammonium salt of the DCOIT - like derivative, the antifouling agent guest molecules are locked in the receptor container by strong chemical bonds, providing a feasible reference for the high - value utilization of inorganic powders and the high - throughput loading of marine antifouling agents. At the same time, the compatibility between the inorganic powder after organic hybridization and the film - forming resin is improved, and it is not easy to sediment in the composition. Subsequently, other micro - nano mesoporous material matrices rich in graftable groups such as halloysite, montmorillonite, zeolite, fumed silica, and metal - organic frameworks can be modified by imitating similar processes. The obtained organic - inorganic hybrid system is much more stable than the weak interactions such as intermolecular hydrogen bonds, van der Waals forces, and electrostatic coupling, making the guest molecules not easily desorb (fall off) due to external stimuli such as sudden changes in temperature, concentration, and pressure. The specially selected "bridging" unit (i.e., the connecting segment between the DCOIT - like derivative and the sepiolite fiber) has a high degree of molecular rotational freedom (good flexibility) and has a dual - degradation characteristic (both diisocyanate and fatty alcohol can be completely degraded). After it gradually disintegrates in the natural environment, the antifouling agent is "unlocked" and can release the drug slowly and continuously. It is worth mentioning that the "comb" - shaped configuration of the organic - inorganic hybrid (the sepiolite fiber is the "comb handle" and the long chain of the antifouling agent is the "comb teeth") can easily achieve more "comb teeth" loading (indicating a larger drug - loading capacity) by adjusting the size of the "comb handle" (selecting fibers with a large aspect ratio).

[0047] 2. The preparation process of the micro - nano mesoporous material is simple (significantly better than micro - encapsulation), the reaction conditions are mild, and it can be obtained by the "one - pot method". The hyperbranched zinc resin in the composition can self - polish, and its shedding under the scouring of water flow can also play a secondary regulation role in the slow release of the antifouling agent. The compounding of cuprous oxide and zinc pyrithione further strengthens and expands the broad - spectrum biocidal property of the DCOIT - like derivative.

[0048] Based on this, the antifouling agent, the micro - nano mesoporous material, and the marine antifouling composition prepared therefrom encapsulate the organic antifouling agent guest molecules in the modified matrix of the micro - nano mesoporous material through strong chemical bonds with high throughput and firmness, having the properties of high efficiency, universality, low toxicity, and long - term effectiveness, and meeting the antifouling requirements of multiple scenarios such as moving ships, offshore pastures, and static platforms. Description of the Drawings

[0049] Figure 1 Schematic diagram of the structure of the micro - nano mesoporous material prepared in Example 1 or 2, where 1 is the sepiolite porous fiber and 2 is the long chain of the antifouling agent chemically loaded on the active silicon hydroxyl groups on the surface and inside of the sepiolite.

[0050] Figure 2 The micro - nano mesoporous material prepared in Example 1 1 HNMR spectrum.

[0051] Figure 3The drug loading amount (TGA) of the antifouling agent in the micro-nano mesoporous material prepared in Example 1.

[0052] Figure 4 SEM images of sepiolite fibers before and after chemically loading the antifouling agent in Example 1, where Figure 4 (a) is the SEM image of sepiolite fibers before chemically loading the antifouling agent, Figure 4 (b) is the SEM image of sepiolite fibers after chemically loading the antifouling agent.

[0053] Figure 5 The dissolution rate of the antifouling agent in artificial seawater in the micro-nano mesoporous materials prepared in Example 1 and Comparative Example 4.

[0054] Figure 6 The anti-fouling effectiveness of the marine anti-fouling composition in shallow waters in Example 3 and Comparative Example 5, where Figure 6 (a) is the photo of the sample sprayed with the marine anti-fouling composition in Example 3 after 2 months in the sea area, Figure 6 (b) is the photo of the sample sprayed with the marine anti-fouling composition in Example 3 after 9 months in the sea area, Figure 6 (c) is the photo of the sample sprayed with the marine anti-fouling composition in Comparative Example 5 after 2 months in the sea area, Figure 6 (d) is the photo of the sample sprayed with the marine anti-fouling composition in Comparative Example 5 after 9 months in the sea area. Detailed implementation manners

[0055] The present invention will be described in more detail below with reference to the accompanying drawings and in combination with embodiments. On the premise of no conflict, the embodiments and the features of the embodiments in the present invention can be combined or transformed with each other.

[0056] Artificial seawater was prepared with reference to "Determination of cathodic disbonding properties of coatings exposed to seawater - Paint and varnishes (GB / T 7790 - 2008)", and the release rate of DCOIT in it was measured using an ultraviolet - visible near - infrared spectrophotometer; the identification of the anti - fouling effect in shallow waters was based on "Test method for immersion of antifouling paint panels in shallow sea (GB / T 5370 - 2007)". Raw materials and reagents were purchased through normal commercial channels and were strictly dried before use, controlling the water content not to exceed 200 ppm.

[0057] Example 1

[0058] The preparation steps of the micro - nano mesoporous material are as follows:

[0059] S1. Take 80 g of sepiolite fibers and ultrasonically disperse them in 2000 mL of 10 wt% dilute hydrochloric acid aqueous solution, magnetically stir at 60 °C for 12 h, then wash with saturated NaHCO 3 solution until neutral, and then transfer to a muffle furnace for calcination at 250 °C for 1.5 h, and cool for use.

[0060] S2. Dissolve 50 mmol of DCOIT and 55 mmol of 6-bromo-1-hexanol in 300 mL of butyl acetate, then add 50 mg of KI, reflux at 50 °C for 10 h, and then slowly dropwise add a mixture of 57.5 mmol of ethyl 2,6-diisocyanatohexanoate and 52 mg of T-12, and continue the heat preservation reaction for 8 h, under the protection of N 2 atmosphere.

[0061] S3. Grind and sieve the modified sepiolite fiber prepared in S1, take 27 g of the 800-mesh powder, ultrasonically disperse it in 300 mL of butyl acetate, and then add it to the S2 system, heat up to 70 °C and continuously stir for 5 h, under the protection of N 2 atmosphere. Finally, after impurity removal, purification, drying and grinding, it is stored. The structure of the prepared micro-nano mesoporous material is as Figure 1 shown.

[0062] Example 2

[0063] The preparation steps of the micro-nano mesoporous material are as follows:

[0064] S1. Take 100 g of sepiolite fiber and ultrasonically disperse it in 2000 mL of 8 wt% dilute hydrochloric acid aqueous solution, magnetically stir at 50 °C for 10 h, and then wash it to neutral with saturated NaHCO 3 solution, and then transfer it to a muffle furnace and calcine at 200 °C for 2 h, and cool for use.

[0065] S2. Dissolve 50 mmol of DCOIT and 55 mmol of 6-bromo-1-hexanol in 250 mL of ethyl acetate, then add 50 mg of NaI, reflux at 45 °C for 12 h, and then slowly dropwise add a mixture of 55 mmol of ethyl 2,5-diisocyanatovalerate and 45 mg of T-12, and continue the heat preservation reaction for 7 h, under the protection of N 2 atmosphere.

[0066] S3. Grind and sieve the modified sepiolite fiber prepared in S1, take 25 g of the 2000-mesh powder, ultrasonically disperse it in 250 mL of ethyl acetate, and then add it to the S2 system, heat up to 65 °C and continuously stir for 6 h, under the protection of N 2 atmosphere. Finally, after impurity removal, purification, drying and grinding, it is stored.

[0067] Example 3

[0068] A marine antifouling composition, by weight, contains 15 parts of the micro-nano mesoporous material described in Example 1, 25 parts of cuprous oxide, 6 parts of zinc pyrithione, 35 parts of hyperbranched zinc resin, 3 parts of modified rosin, 2 parts of polyethylene wax, 1 part of chlorinated paraffin, 8 parts of talcum powder, 1 part of iron oxide red, 10 parts of xylene, and 5 parts of n-butanol.

[0069] Example 4

[0070] A marine antifouling composition, by weight, contains 20 parts of the micro-nano mesoporous material described in Example 2, 25 parts of cuprous oxide, 4 parts of zinc pyrithione, 38 parts of hyperbranched zinc resin, 2 parts of modified rosin, 3 parts of polyethylene wax, 2 parts of chlorinated paraffin, 10 parts of talcum powder, 12 parts of xylene, and 6 parts of n-butanol.

[0071] Comparative Example 1

[0072] The preparation steps of the micro-nano mesoporous material are as follows:

[0073] S1. Dissolve 50 mmol of DCOIT and 55 mmol of 6-bromo-1-hexanol in 300 mL of butyl acetate, then add 50 mg of KI, reflux at 50 °C for 10 h, and then slowly dropwise add a mixture of 57.5 mmol of ethyl 2,6-diisocyanatohexanoate and 52 mg of T-12, and continue the insulation reaction for 8 h, under the protection of N 2 atmosphere.

[0074] S2. After vacuum drying sepiolite fiber at 105 °C for 2 h, sieve to obtain about 27 g of powder with a mesh size of about 800, ultrasonically disperse it in 300 mL of butyl acetate, then add it to the S1 system, heat up to 70 °C and continuously stir for 5 h, under the protection of N 2 atmosphere, and finally store it after impurity removal, purification, drying, and grinding.

[0075] Comparative Example 2

[0076] Take 4 g of sepiolite fiber and ultrasonically disperse it in 100 mL of 20 wt% hydrochloric acid aqueous solution, stir magnetically at 60 °C for 12 h, and then wash it with saturated NaHCO 3 solution until neutral, and then sample to observe the fiber morphology.

[0077] Comparative Example 3

[0078] Take 4 g of sepiolite fiber and ultrasonically disperse it in 100 mL of 10 wt% dilute hydrochloric acid aqueous solution, stir magnetically at 60 °C for 12 h, and then wash it with saturated NaHCO 3 solution until neutral, then transfer it to a muffle furnace and calcine it at 400 - 500 °C for 2 h, and sample to observe the fiber morphology after cooling.

[0079] Comparative Example 4

[0080] The preparation steps of the micro-nano mesoporous material are as follows:

[0081] The sepiolite fiber was not pretreated at all. Directly take about 27 g of powder with a mesh size of about 800, ultrasonically disperse it in 300 mL of butyl acetate dissolved with 50 mmol of DCOIT, soak it at room temperature for 48 h, and then dry it for use.

[0082] Comparative Example 5

[0083] A marine antifouling composition, except for the micro-nano mesoporous material prepared in Comparative Example 4, the remaining raw materials and dosages are the same as those in Example 3.

[0084] Analysis shows that in the FT-IR spectrum of the product obtained in Example 1, the Si-OH peak attributed to the modified sepiolite at 3460 cm -1 Although it is significantly weakened compared with that before polyurethaneization, it still appears, indicating that there is reaction redundancy of silanol groups. The C-Cl peak on the isothiazolinone ring appears at 840 cm -1 The -NCO peak attributed to ethyl 2,6-diisocyanatohexanoate at around 2260 cm -1 is significantly weakened after the S2 step and basically disappears after the S3 step. A new -NHCOO- peak appears near 1640 cm -1 and 1560 cm -1 A new stretching vibration peak of the Si-OCO- bond appears before and after 1100 cm -1 and 800 cm -1 , indicating that DCOIT has been successfully covalently grafted to the sepiolite fiber through the polyurethane bridging unit ( Figure 2 The 1 1H NMR spectrum can also prove it).

[0085] TGA thermogravimetric analysis (as Figure 3 shown) found that the heat resistance of DCOIT after grafting is improved, and the drug loading of the fiber reaches 60.6% (higher than the patent with the publication number CN115141508B), achieving high-throughput loading. Compared with dialysis dissolution and concentration enrichment detection, thermogravimetric analysis can more accurately and intuitively reflect the weight loss situation at each temperature stage, excluding the influence of the distortion of chemical drug loading data (mainly manifested as being too high) caused by some guest molecules entering the receptor pores through physical adsorption (the strength of intermolecular interaction can have a stress response to different temperatures, and the physical adsorption force is small, and desorption weight loss occurs in the low-temperature region, so it is easy to identify and distinguish).

[0086] In addition, SEM shows that the sepiolite used in Example 1 has a complete and relatively loose fiber morphology (even has been unbundled into single filaments) after S1 acid etching + calcination, with a smooth surface and a length exceeding 4 μm (as shown in Figure a of Figure 4 ). After the S3 step, the surface roughness of the fiber increases (as shown in Figure b of Figure 4 ), covered with dot-like protrusions, which also indirectly confirms the successful linking of DCOIT again.

[0087] The peak shape displacements of the composition in Example 2 in the FT-IR spectrum are basically the same as those in Example 1. The drug loading measured by TGA is 54.8%. The reason may be that the modified sepiolite fiber used is relatively short and thick (2000 mesh), and the loading of the "comb-like" antifouling agent long chain is slightly lower.

[0088] Correspondingly, if the sepiolite is not treated in advance, such as in Comparative Example 1, the fiber crystals are dense, the intrinsic silanol groups in the superficial surface and internal cavities are few and the activity is low, and the free water is not completely calcined, resulting in the -NCO group being consumed without value, the number of "bridges" of polyurethane units is limited, and a large amount of DCOIT quaternary ammonium alcohol salts cannot be covalently bonded to the sepiolite molecules, and the chemical drug loading is less than 30%. During TGA detection, a large proportion of abnormal burning loss occurs in the low temperature zone (similar to Comparative Example 4), which also reflects that the guest molecules are still mostly coupled in the form of physical adsorption.

[0089] In order to investigate the effects of hydrochloric acid solubility and calcination temperature in step S1 on the pore structure of sepiolite, we specially designed comparative examples 2 and 3. Under SEM, it can be observed that when the hydrochloric acid concentration increases from 15% to 20wt%, the fiber begins to show a decrease in specific surface area, pore blockage, and fiber breakage; and when calcined above 400℃, the crystal water (and even hydroxyl water) in the fiber is continuously lost, and the pores gradually collapse.

[0090] Depend on Figure 5 It is not difficult to see that the release of DCOIT in Example 1 is basically stable after about 14 days in artificial seawater, and it has been "progressively" dissolved (almost close to constant speed) in the subsequent 98 days. The dual degradation process of the polyurethane covalent bridging site and the self-polishing of the hyperbranched zinc resin play a good role in the "locking → unlocking" slow release regulation. The weak intermolecular force in Comparative Example 4 is not enough to support the long-term loading of DCOIT in the receptor pore (stable section 14-49 days). As the immersion time increases, the drug release increases significantly after 50 days. It is easy to foresee that at this rate, the drug dosage will be exhausted in the near future.

[0091] Figure 6 The difference in antifouling performance in a certain sea area of ​​the South China Sea after the samples were sprayed with the marine antifouling compositions in Example 3 and Comparative Example 5 was clearly reflected. After the summer and autumn (more than 9 months) when marine organisms reproduced vigorously, the surface of the coating in Example 3 was smooth and clean, and the influence of the sample edge effect was eliminated. There were few species climbing in the central area (such as Figure 6 In contrast, in Comparative Example 5, a large number of barnacles and mussels grew, occupying nearly 1 / 3 of the area (as shown in Figure b). Figure 6 In fact, the killing effect of comparative example 5 in the first two months was not significantly different from that of embodiment 3 ( Figure 6 C-graph Vs. Figure 6 Figure a), however, due to the difference in the antifouling agent system, in Comparative Example 5, DCOIT is physically adsorbed by sepiolite alone, and it is difficult for sepiolite to restrict its slow release for a long time, and it gradually becomes exhausted after a certain period of time; thanks to the strong chemical bonding, the antifouling system of Example 3 has a "zero-order" drug release function. After the "bridge" connecting the sepiolite fibers slowly disintegrates, DCOIT is gradually "unlocked" to exert a long-term effect.

[0092] In summary, through mature means such as simple hydrothermal acid etching, quaternization, and silanol amino esterification, the DCOIT-like derivative guest molecules are firmly encapsulated in the sepiolite receptor container, providing a valuable reference for the high-order utilization of inorganic powders and the high-throughput chemical loading (60.6%) of marine antifouling agents. Subsequently, other micro-nano mesoporous material matrices rich in graftable functional groups such as halloysite, montmorillonite, zeolite, fumed silica, and metal-organic frameworks, which contain active hydroxyl groups, amino groups, etc., can be modified in the same way. The components of the marine antifouling composition prepared with this organic-inorganic hybrid slow-release system have good compatibility, and have the properties of high efficiency, broad spectrum, low toxicity, and long effectiveness, and are suitable for the antifouling needs of various scenarios such as moving ships, offshore pastures, and static platforms.

[0093] The content clarified in the above embodiments should be understood that these embodiments are only used to interpret the present invention more clearly, rather than limiting the scope of the present invention. After referring to the present invention, various equivalent forms of modification made by those skilled in the art inspired by this fall within the protection scope defined by the appended claims of the present invention.

Claims

1. An antifouling agent, characterized in that: Contains the following molecular structure: ； The preparation method of the antifouling agent comprises the following steps: Dissolve the DCOIT-like derivative and the halogenated fatty alcohol in a solvent, heat to reflux, then dropwise add a mixture of diisocyanate and a catalyst, and continue to keep the temperature to react; The structure of the DCOIT-like derivative is as shown in Formula II: ； In formula II, R1 and R2 are both -Cl; R3 is -C8H 17 ; The halogenated fatty alcohol is a chlorinated, brominated or iodinated fatty alcohol containing 1 to 8 carbon atoms; The diisocyanate is 2,3-diisocyanatopropionate, 2,4-diisocyanatobutyrate, 2,5-diisocyanatovalerate, 2,6-diisocyanatohexanoate, 2,7-diisocyanatoheptanoate, 2,8-diisocyanatooctanoate, 2,9-diisocyanatononanoate or 2,10-diisocyanatodecanoate.

2. A micro-nano mesoporous material, characterized in that: The invention comprises a micro-nano mesoporous material matrix and the antifouling agent according to claim 1, wherein the activated silanol groups in the micro-nano mesoporous material matrix are covalently linked to -NCO units in the antifouling agent.

3. The micro-nano mesoporous material according to claim 2, characterized in that: The micro-nano mesoporous material matrix includes one or more of sepiolite, halloysite, montmorillonite, zeolite, gas silica and organic metal framework.

4. The micro-nano mesoporous material according to claim 3, characterized in that: When the micro-nano mesoporous material matrix is ​​sepiolite, the particle size of the micro-nano mesoporous material matrix is ​​200-3000 meshes.

5. The micro-nano mesoporous material according to any one of claims 2 to 4, characterized in that: The preparation method of the micro-nano mesoporous material comprises the following steps: S1, subjecting the micro-nano mesoporous material substrate to hydrothermal acid etching, cleaning, calcination, and cooling for standby use; S2, dissolving the DCOIT-like derivative and the halogenated fatty alcohol in a solvent, heating to reflux, then dropping a mixture of diisocyanate and a catalyst, and continuing the reaction at a heat preservation temperature; S3, grinding and dispersing the modified matrix of the micro-nano mesoporous material obtained in S1 in a solvent, adding it into the S2 system to react at a high temperature, and then purifying, drying, grinding and storing it; The structure of the DCOIT-like derivative is as shown in Formula II: ； In formula II, R1 and R2 are both -Cl; R3 is -C8H 17 ; The halogenated fatty alcohol is a chlorinated, brominated or iodinated fatty alcohol containing 1 to 8 carbon atoms; The diisocyanate is 2,3-diisocyanatopropionate, 2,4-diisocyanatobutyrate, 2,5-diisocyanatovalerate, 2,6-diisocyanatohexanoate, 2,7-diisocyanatoheptanoate, 2,8-diisocyanatooctanoate, 2,9-diisocyanatononanoate or 2,10-diisocyanatodecanoate.

6. A marine antifouling composition, characterized in that The invention comprises 10 to 30 parts of the micro-nano mesoporous material according to any one of claims 2 to 5, and further comprises 25 to 45 parts of cuprous oxide, 5 to 10 parts of zinc pyrithione, 30 to 40 parts of hyperbranched zinc resin, 3 to 5 parts of modified rosin, 1 to 3 parts of polyethylene wax, 0 to 3 parts of chlorinated paraffin, 0 to 10 parts of filler, 0 to 3 parts of red iron oxide, and 10 to 20 parts of organic solvent.

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