Marine antifouling paint with main chain degradation and drag reduction functions and preparation method thereof

Abstract

The invention relates to a marine antifouling paint with main chain degradation and drag reduction functions and a preparation method thereof, and relates to the technical field of marine antifouling paints.The marine antifouling paint is prepared from, by weight, 5-40 parts of marine antifouling resin with the main chain degradation and drag reduction functions, 0-10 parts of other resin, 0-40 parts of cuprous oxide, 0-10 parts of organic antifouling agent, 2-40 parts of pigment filler and 0-3 parts of thixotropic agent. And 10-40 parts of a solvent. Compared with the existing acrylate tin-free self-polishing paint, the acrylate tin-free self-polishing paint only contains hydrolyzable side groups, the surface updating of the acrylate tin-free self-polishing paint depends on the scouring of strong water flow, and the static antifouling effect is not ideal; the antifouling resin prepared by the invention has excellent main chain degradation performance and can show an excellent static antifouling effect; meanwhile, in the degradation process, silicone oil can be continuously released to the surface of the coating, the surface energy of the surface of the coating is reduced, and therefore the drag reduction effect is achieved. The operation method is simple, the cost is low, the method can be suitable for various sea areas, and the method has wide application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of marine antifouling materials, and in particular to a marine antifouling coating with main chain degradation and drag reduction functions and a preparation method thereof. Background Art

[0002] Marine organisms can attach to equipment operating in the ocean, posing a huge threat to the modern marine economy.

[0003] Applying antifouling coatings is the most economical and effective method to solve fouling and corrosion. Among them, silicone-based fouling-release coatings and polyacrylate self-polishing coatings are currently the best performing and most widely used marine antifouling coatings. However, the fouling-release performance of silicone-based fouling-release coatings depends on high water flow scouring, and cannot inhibit the attachment of marine organisms under static conditions. In addition, there are problems such as low mechanical strength and poor adhesion to the substrate. Polyacrylate self-polishing coatings are mainly based on self-polishing resins of zinc polyacrylate, copper or silane esters, and the antifouling effect can reach 3-5 years. However, the formula design of this antifouling coating is mainly aimed at large ships such as ocean-going ships, and its performance has certain requirements on the voyage period and speed. This is because the existing self-polishing resin structure contains only hydrolyzable side groups, which makes its surface self-renewal dependent on the scouring of strong water flow, and its static anti-fouling ability is not ideal; in addition, the attachment of marine organisms can increase the resistance of ships' navigation. The global maritime transportation industry loses $150 billion each year due to marine biofouling, of which the additional fuel consumption is $30 billion (energy consumption increases by about 10% due to biofouling), so the drag reduction performance of the coating is also of great significance.

[0004] Among the main chain degradable polymer antifouling coatings that are currently being studied more, common ones include polyesters such as polycaprolactone (PCL), polylactic acid (PLA), polybutylene succinate (PBS), and polybutylene adipate / terephthalate (PBAT). In seawater, they can form a constantly updated dynamic surface by breaking the main chain, making it difficult for marine microorganisms to attach. At the same time, the material is degraded into non-toxic small molecules, which are environmentally friendly antifouling materials. However, they also have the disadvantages of slow marine hydrolysis and difficulty in regulating the degradation rate. Taking polylactic acid as an example, whether the PLA sample is placed in fresh water or in the ocean, after one year of immersion, no obvious weight loss is observed in the PLA sample, and the GPC test shows that there is no obvious change in molecular weight. For other polyester plastics, such as PBAT and PBS, after being immersed in seawater for one year, their weight loss rate is also less than 2%, and the degradation is very slow. Polyglycolic acid, also known as polyhydroxyacetic acid, is polymerized from glycolic acid. Polyglycolic acid has a simple and regular linear molecular structure and is the simplest linear aliphatic polyester. Because it has the shortest repeating unit, it has the fastest hydrolysis rate among aliphatic polyesters. Similarly, polyglycolic acid copolymers also have a fast hydrolysis rate, and their low molecular weight products are ideal hydrolysis inducers. Taking polyglycolic acid as an example, polyglycolic acid specimens were placed in the ocean. After 6 months of immersion, the polyglycolic acid specimens basically disappeared.

[0005] Therefore, there is a need for a marine antifouling coating having both main chain degradation and drag reduction properties and a preparation method thereof. Summary of the invention

[0006] The purpose of the present invention is to provide a marine antifouling coating with both main chain degradation and drag reduction functions and a preparation method thereof in order to solve the above problems. The antifouling resin prepared by the present invention has excellent main chain degradation performance and can show excellent static antifouling effect; at the same time, during the degradation process, it can also continuously release silicone oil to the coating surface to reduce the surface energy of the coating surface, thereby achieving the effect of drag reduction. The operation method of the present invention is simple, the cost is low, it can be applied to a variety of sea areas, and has a wide range of application prospects. The antifouling coating has excellent main chain degradation performance and can show excellent static antifouling effect; at the same time, during the degradation process, it can also continuously release silicone oil to the coating surface to reduce the surface energy of the coating surface, thereby achieving the effect of drag reduction.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] The first object of the present invention is to provide a marine antifouling coating having both backbone degradation and drag reduction functions, wherein the marine antifouling coating comprises the following components in percentage by weight:

[0009]

[0010] More preferably, the marine antifouling coating having both backbone degradation and drag reduction functions comprises the following weight percentages:

[0011]

[0012]

[0013] Preferably, the structure of the marine antifouling resin having both main chain degradation and drag reduction functions is as shown in the following formula (I):

[0014]

[0015] Wherein, m and n are integers;

[0016] The structure represented by R is shown in the following formula (II):

[0017]

[0018] Where x, y and z are integers;

[0019] R1 represents an alkyl group or an aryl group having 1 or more carbon atoms;

[0020] R2 represents an alkyl group or an aryl group having 1 or more carbon atoms;

[0021] R' represents an alkyl group or an aryl group having 1 or more carbon atoms;

[0022] R3 represents an alkyl group having 1 or more carbon atoms;

[0023] R4 represents one of a methyl group, a hydroxy group, an amino group or an alcoholic hydroxy group.

[0024] Preferably, the marine antifouling resin having both main chain degradation and drag reduction functions can be prepared by the following steps:

[0025] a) Under nitrogen protection, lactic acid, glycolic acid, polyacid, polyol compound and catalyst are subjected to esterification and polycondensation reaction at 140-200°C, the top temperature of the fractionation tower is controlled between 100-105°C, most of the by-product water generated is distilled off at normal pressure, and then the temperature is kept between 200-230°C for 1-2h;

[0026] b) evacuating the mixture and gradually increasing the vacuum degree to remove trace amounts of water and excess polyol compounds under reduced pressure until the acid value of the synthesized product is lower than 5 mgKOH / g to obtain polylactic acid glycolic acid copolymer polyol; the reaction time is 4 to 12 hours;

[0027] c) Add terminal alcohol hydroxy silicone oil to the polylactic acid glycolic acid copolymer polyol obtained in step b), continue stirring for 0.5 to 2 hours, cool to 60 to 100° C., and add a proper amount of solvent B to dissolve. After dissolution, add a proper amount of isocyanate compound dropwise at 60 to 100° C., and continue to react for 0.5 to 3 hours after the addition is complete, to obtain a marine antifouling resin with both main chain degradation and drag reduction functions.

[0028] Preferably, the chemical reaction structure of step a) is as follows:

[0029]

[0030] Wherein R1 and R2 represent an alkyl group or an aryl group having 1 or more carbon atoms, and a, b, c, x, y, z, m and n are integers.

[0031] For ease of representation,

[0032]

[0033] The following may be referred to as

[0034] HO-R-OH.

[0035] Preferably, the viscosity of the terminal alcohol hydroxy silicone oil in step c) is between 100 and 10000 cs, and its structural formula is as follows:

[0036]

[0037] Where R represents an alkyl group with 1 or more C atoms,

[0038] R4 represents one of a methyl group, a hydroxy group, an amino group or an alcoholic hydroxy group.

[0039] Furthermore, ordinary hydroxy silicone oil has poor compatibility with polylactic acid-glycolic acid copolymer polyol. Although the two can achieve the effect of continuous release of silicone oil to the coating surface by blending, the resulting coating has poor physical properties, is easily stratified, and the release rate of silicone oil is difficult to control. In fact, terminal alcohol hydroxy silicone oil is selected, and the terminal alcohol hydroxyl group of the silicone oil can be cross-linked with polylactic acid-glycolic acid copolymer polyol through isocyanate groups, thereby increasing the compatibility of the two and making the release rate of silicone oil controllable.

[0040] Preferably, the solvent B in step c) is one or more of toluene, xylene, ethyl acetate, butyl acetate and methyl isobutyl ketone.

[0041] Preferably, the polyacid in step a) includes one or more of oxalic acid, terephthalic acid, succinic acid and adipic acid.

[0042] Preferably, the polyol compound in step a) comprises one or more of an aliphatic polyol compound and a polyether polyol.

[0043] Preferably, the polyol compound specifically includes one or more of ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, neopentyl glycol, hexylene glycol, isohexylene glycol, trimethylolpropane, pentaerythritol, polyethylene glycol 200, polyethylene glycol 400 and polyethylene glycol 800.

[0044] Preferably, the mass ratio of the glycolic acid in step a) to all monomers (excluding catalyst) is 10-80%.

[0045] Preferably, the molecular weight of the polylactic acid-glycolic acid copolymer polyol is 1,000 to 30,000.

[0046] More preferably, the mass proportion of the glycolic acid in step a) is 20-50%.

[0047] More preferably, the molecular weight of the polylactic acid-glycolic acid copolymer polyol is 2,000-10,000.

[0048] Furthermore, the degradation rate is related to the molecular weight of the polylactic acid glycolic acid copolymer polyol. The larger the molecular weight, the slower the degradation rate. In addition, the degradation rate is related to the glycolic acid content in the marine antifouling resin with both main chain degradation and drag reduction functions. The higher the glycolic acid content, the faster the hydrolysis rate.

[0049] In fact, polyglycolic acid has a simple and regular linear molecular structure and is the simplest linear aliphatic polyester. Since its repeating unit is the shortest, there is no other group protection around its ester group and it is basically in a "naked" state. It is extremely susceptible to attack by water molecules and has the fastest hydrolysis rate among aliphatic polyesters. Similarly, polylactic acid-glycolic acid copolymer also has a fast hydrolysis rate. The higher the glycolic acid content, the faster the hydrolysis rate. However, when the glycolic acid content is too high, the crystallinity of polylactic acid-glycolic acid copolymer will increase, thereby reducing the solubility of the antifouling resin and affecting the physical properties of the antifouling coating.

[0050] Preferably, the catalyst in step a) includes one or more of stannous octoate, stannous chloride, tetrabutyl titanate, zinc acetate, antimony acetate, antimony trioxide and ethylene glycol antimony.

[0051] Preferably, the amount of the catalyst in step a) is 0.01-2 wt % of the mass of glycolic acid.

[0052] Preferably, the isocyanate compound in step c) is one or more of an adduct of toluene diisocyanate and trimethylolpropane (TDI-TMP), hexamethylene diisocyanate trimer (HDI trimer), isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI) and toluene diisocyanate dimer (TDI dimer); hereinafter referred to as

[0053] OCN-R′-NCO,

[0054] Here, R' represents an alkyl group having 1 or more carbon atoms, an aryl group, or the like.

[0055] Preferably, the chemical reaction structural formula in step c) is as follows:

[0056]

[0057] Where x, y, z, m and n are integers.

[0058] Preferably, the other resins include one or more of horsetail rosin, hydrogenated rosin, rosin glycerol ester, self-polishing acrylate resin and polyurethane resin.

[0059] More preferably, the other resins include one or more of horsetail rosin, hydrogenated rosin, and rosin glycerol ester.

[0060] Furthermore, the other resins need to have good compatibility with the marine antifouling resin having both main chain degradation and drag reduction functions; the combination of the two can adjust the physical properties and degradation rate of the coating, thereby being suitable for different sea areas.

[0061] Preferably, the organic antifouling agent includes one or more of copper pyrithione, mancozeb, (4,5-dichloro-N-octyl-4-isothiazoline-3-one)isothiazolinone derivatives, and the like.

[0062] Preferably, the pigment filler includes one or more of nano silicon dioxide, polytetrafluoroethylene, zinc oxide, calcium carbonate, talcum powder, diatomaceous earth, mica powder, titanium dioxide, antimony oxide, barium sulfate and red iron oxide.

[0063] Furthermore, pigments and fillers are important auxiliary materials for the preparation of marine antifouling coatings. They can give the coatings different colors and a certain covering power. At the same time, they can effectively improve the consistency of the antifouling coatings and improve the durability, weather resistance, heat resistance and mechanical strength of the coating film.

[0064] Preferably, the thixotropic agent includes one or more of organic bentonite, fumed silica, cellulose ethers, polyamide wax, and the like.

[0065] Furthermore, the addition of a thixotropic agent can increase the viscosity of the marine antifouling coating, prevent sagging during construction, and prevent stratification during storage of the coating, thereby improving the storage stability of the coating.

[0066] Preferably, the solvent A is one or more of toluene, xylene, ethyl acetate, butyl acetate and methyl isobutyl ketone.

[0067] The second object of the present invention is to provide a method for preparing the marine antifouling coating having both main chain degradation and drag reduction functions. The marine antifouling coating having both main chain degradation and drag reduction functions can be prepared by the following method:

[0068] (1) According to the above ratio, firstly, solvent A is placed in a disperser, stirred at a speed of 500 to 1000 r / min, and the marine antifouling resin having both main chain degradation and drag reduction functions and the other resins are added until the resin is completely dissolved;

[0069] (2) adding a thixotropic agent, continuing stirring for 10 to 20 minutes, and then sequentially adding cuprous oxide, pigments and fillers, and an organic antifouling agent in the order from liquid to powder and from small to large specific gravity, and continuing to disperse at a speed of 2000 to 3000 r / min for 30 to 60 minutes to obtain the marine antifouling coating having both main chain degradation and drag reduction functions.

[0070] Compared with the prior art, the beneficial effects of the present invention are embodied in the following aspects:

[0071] (1) The marine antifouling coating with both main chain degradation and drag reduction functions of the technical solution has a main chain degradation function: according to the design of the molecular structure, a series of marine antifouling resins with both main chain degradation and drag reduction functions can be prepared. These resins have excellent main chain degradation performance and do not require external water flow scouring. They have excellent antifouling effects even in a static state.

[0072] (2) The marine antifouling resin with both main chain degradation and drag reduction functions developed by this technical solution will continuously release silicone oil to the coating surface during the degradation process, thereby reducing the surface energy of the coating surface and increasing the difficulty of attachment of marine organisms, thereby achieving the effect of drag reduction.

[0073] (3) The marine antifouling coating with both main chain degradation and drag reduction functions developed by this technical solution has high strength and adhesion and excellent physical properties.

[0074] (4) The marine antifouling resin with main chain degradation and drag reduction functions developed by this technical solution can be biodegraded in the ocean, reducing the generation of marine microplastics, and is an environmentally friendly antifouling resin; at the same time, the resin can also be used in combination with other resins, thereby breaking through the limitation of the weak static antifouling ability of the existing self-polishing technology.

[0075] (5) The marine antifouling resin with main chain degradation and drag reduction functions developed by this technical solution has abundant raw material sources, simple production process, affordable price, and is easy to carry out industrial production.

[0076] In summary, the marine antifouling coating with main chain degradation and drag reduction functions provided by the present invention can play a good antifouling role even in a static state; at the same time, during the degradation process, the coating will continuously release silicone oil to the coating surface, reduce the surface energy of the coating surface, and increase the difficulty of marine organisms to attach, thereby achieving the effect of drag reduction. More importantly, the present invention has a simple operation method, low cost, is suitable for industrial production, has a wide range of application prospects, and can generate great social benefits.

[0077] Compared with the current acrylic ester Wuxi self-polishing coatings, which generally contain only hydrolyzable side groups, their surface renewal depends on the scouring of strong water flow, and the static antifouling effect is not ideal; the antifouling resin prepared by the present invention has excellent main chain degradation performance and can show excellent static antifouling effect; at the same time, during the degradation process, silicone oil can be continuously released to the coating surface to reduce the surface energy of the coating surface, thereby achieving the effect of drag reduction. The present invention has a simple operation method, low cost, can be applied to a variety of sea areas, and has a wide range of application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 Schematic diagram of shallow sea immersion experiments of Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6, Comparative Example 1 and Comparative Example 2 (from left to right). DETAILED DESCRIPTION

[0079] The present invention is described in detail below in conjunction with specific embodiments, but is by no means intended to limit the present invention. Features such as preparation methods, materials, structures or composition ratios not explicitly described in this technical solution are considered to be common technical features disclosed in the prior art.

[0080] The present invention provides a marine antifouling coating having both main chain degradation and drag reduction functions, comprising the following weight percentages:

[0081]

[0082] More preferably, the marine antifouling coating having both backbone degradation and drag reduction functions comprises the following weight percentages:

[0083]

[0084] The present application provides a marine antifouling coating having both main chain degradation and drag reduction functions. The degradation speed has a certain relationship with the molecular weight of polylactic acid glycolic acid copolymer polyol. The larger the molecular weight, the slower the degradation speed. In addition, the degradation speed is related to the glycolic acid content in the marine antifouling resin having both main chain degradation and drag reduction functions. The higher the glycolic acid content, the faster the hydrolysis speed.

[0085] In fact, polyglycolic acid has a simple and regular linear molecular structure and is the simplest linear aliphatic polyester. Since its repeating unit is the shortest, there is no other group protection around its ester group and it is basically in a "naked" state. It is extremely susceptible to attack by water molecules and has the fastest hydrolysis rate among aliphatic polyesters. Similarly, polylactic acid-glycolic acid copolymer also has a fast hydrolysis rate. The higher the glycolic acid content, the faster the hydrolysis rate. However, when the glycolic acid content is too high, the crystallinity of polylactic acid-glycolic acid copolymer will increase, thereby reducing the solubility of the antifouling resin and affecting the physical properties of the antifouling coating.

[0086] Ordinary hydroxy silicone oil has poor compatibility with polylactic acid glycolic acid copolymer polyol. Although the two can achieve the effect of continuous release of silicone oil to the coating surface by blending, the resulting coating has poor physical properties, is easy to stratify, and the release rate of silicone oil is difficult to control. In fact, terminal alcohol hydroxy silicone oil is selected, the terminal alcohol hydroxyl group of the silicone oil can be cross-linked with polylactic acid glycolic acid copolymer polyol through isocyanate group, which increases the compatibility of the two and makes the release rate of silicone oil controllable.

[0087] The other resins need to have good compatibility with the marine antifouling resin having both main chain degradation and drag reduction functions; the combination of the two can adjust the physical properties and degradation rate of the coating, so that it is suitable for different sea areas.

[0088] Pigments and fillers are important auxiliary materials for the preparation of marine antifouling coatings. They can give the coatings different colors and a certain covering power. At the same time, they can effectively improve the consistency of the antifouling coatings and improve the durability, weather resistance, heat resistance and mechanical strength of the coating film.

[0089] The addition of thixotropic agent can increase the viscosity of marine antifouling coatings, prevent sagging during construction, and prevent stratification during storage of the coatings, thereby improving the storage stability of the coatings.

[0090] Cuprous oxide is an antifouling agent with a relatively high price. If the effect can be achieved without using it, costs can be saved.

[0091] In the following embodiments:

[0092] The acid value determination method is as follows: weigh 1-3g of polymer polyol, place it in a three-necked flask, add 20-30mL of a toluene-ethanol (2:1) mixed solution, shake the conical flask to completely dissolve the sample, heat it when necessary, drop 1% phenolphthalein indicator, titrate with 0.1mol / L standard KOH solution until it turns slightly red, and the end point is that it does not fade within 30s, and at the same time, a blank test is performed according to the same method.

[0093]

[0094] Where:

[0095] V 试验 ——The volume of standard KOH solution consumed in the test, mL;

[0096] V 空白 ——Blank consumption of KOH standard solution volume, mL;

[0097] C——molar concentration of KOH standard solution, mol / L;

[0098] W——sample mass, g;

[0099] 56.10 – The molar mass of potassium hydroxide, g / mol.

[0100] The surface energy testing method is: testing is performed with reference to the contact angle method in ISO 8296 standard.

[0101] The present invention has no special restrictions on the raw materials used above, and they can be generally commercially available. Among them, terminal alcohol hydroxy silicone oil was purchased from Anhui Aiyota Silicone Oil Co., Ltd. Rosin resin was purchased from Hubei Heifeima Chemical Technology Co., Ltd. Fumed silica was purchased from Evonik Degussa.

[0102] To further illustrate the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0103] The experimental methods in the following examples of the present invention without specifying specific conditions are generally based on conventional conditions.

[0104] Example 1

[0105] This embodiment provides a marine antifouling coating having both main chain degradation and drag reduction functions.

[0106] Preparation of polylactic acid glycolic acid copolymer polyol:

[0107] a) 71.6 g (0.7 mol) of lactic acid with a mass concentration of 88%, 38 g (0.3 mol) of glycolic acid with a mass concentration of 60%, 35.4 g (0.3 mol) of succinic acid, 36 g (0.35 mol) of 1,4-butanediol and 0.2 g of tetrabutyl titanate were added to a reactor, the oil bath was heated to 180°C, the temperature of the top of the fractionation tower was maintained at 100-105°C, and the reaction was carried out for 3 hours; then the temperature was kept at 200°C for 1 hour;

[0108] b) evacuating the mixture and gradually increasing the degree of vacuum to remove trace amounts of water and excess ethylene glycol under reduced pressure until the acid value of the synthesized product is lower than 5 mgKOH / g, thereby obtaining a waxy poly(lactic acid-co-glycolic acid) copolymer polyol;

[0109] c) adding 5 g of terminal alcohol hydroxy silicone oil to the polylactic acid glycolic acid copolymer polyol obtained in step b), stirring for 1 h, cooling to 80° C., adding 10 g of butyl acetate and 10 g of xylene for dissolution, and then dropping 2 g of toluene diisocyanate. After the titration is completed, continuing the reaction for 1 h to obtain a marine antifouling resin (solid content 80±2%) having both main chain degradation and drag reduction functions.

[0110] Prepare marine antifouling coating according to the following weight ratio:

[0111] The invention comprises: 20g of marine antifouling resin having main chain degradation and drag reduction functions, 5g of horsetail rosin resin, 25g of cuprous oxide, 3g of organic antifouling agent, 26g of pigment and filler, 1g of thixotropic agent-organic bentonite and 20g of solvent.

[0112] Among them, 3g of the organic antifouling agent is copper pyrithione; 26g of the pigment filler specifically includes 5g of red iron oxide, 5g of zinc oxide and 16g of talcum powder; and 20g of the solvent is butyl acetate.

[0113] The marine antifouling coating with both main chain degradation and drag reduction functions is prepared by the following method:

[0114] (1) According to the above ratio, firstly, butyl acetate solvent is placed in a disperser, and at a speed of 1000 r / min, the marine antifouling resin having both main chain degradation and drag reduction functions and the other resins are added until the resin is completely dissolved;

[0115] (2) Add a thixotropic agent and continue stirring for 20 minutes, then add an organic antifouling agent, cuprous oxide, zinc oxide, talcum powder and red iron oxide in sequence, and continue dispersing at a speed of 3000 r / min for 60 minutes to obtain a marine antifouling coating with both main chain degradation and drag reduction functions.

[0116] Embodiment 2:

[0117] This embodiment provides a marine antifouling coating having both main chain degradation and drag reduction functions.

[0118] The preparation of polylactic acid glycolic acid copolymer polyol is the same as in Example 1.

[0119] Prepare marine antifouling coating according to the following weight ratio: (excluding cuprous oxide)

[0120] The invention comprises: 20g of marine antifouling resin having main chain degradation and drag reduction functions, 5g of horsetail rosin resin, 10g of organic antifouling agent, 44g of pigment and filler, 1g of thixotropic agent - organic bentonite and 20g of solvent.

[0121] Among them, 10g of the organic antifouling agent is a (4,5-dichloro-N-octyl-4-isothiazoline-3-one) isothiazolinone derivative; 44g of the color filler specifically includes 10g of red iron oxide, 10g of zinc oxide and 24g of barium sulfate; and 20g of the solvent is butyl acetate.

[0122] The preparation of the marine antifouling coating with both main chain degradation and drag reduction functions is the same as in Example 1.

[0123] Embodiment 3:

[0124] This embodiment provides a marine antifouling coating having both main chain degradation and drag reduction functions.

[0125] Preparation of polylactic acid glycolic acid copolymer polyol:

[0126] a) 61.4 g (0.6 mol) of lactic acid with a mass concentration of 88%, 50.7 g (0.3 mol) of glycolic acid with a mass concentration of 60%, 10.4 g (0.1 mol) of malonic acid, 14.4 g (0.16 mol) of 1,4-butanediol and 0.4 g of stannous octoate were added to a reactor, the oil bath was heated to 190°C, the temperature of the top of the fractionation tower was maintained at 100-105°C, and the reaction was carried out for 4 hours; then the temperature was kept at 210°C for 2 hours;

[0127] b) evacuating the mixture and gradually increasing the degree of vacuum to remove trace amounts of water and excess ethylene glycol under reduced pressure until the acid value of the synthesized product is lower than 5 mgKOH / g, thereby obtaining a waxy poly(lactic acid-co-glycolic acid) copolymer polyol;

[0128] c) Add 8 g of terminal alcohol hydroxy silicone oil, stir for 1 hour, cool to 70°C, add 15 g of butyl acetate and 5 g of xylene to dissolve, then add 3 g of hexamethylene diisocyanate (HDI) dropwise, and after titration, continue the reaction for 2 hours to obtain a marine antifouling resin (solid content 82±2%) with both main chain degradation and drag reduction functions.

[0129] Prepare marine antifouling coating according to the following weight ratio:

[0130] The invention comprises: 25g of marine antifouling resin having main chain degradation and drag reduction functions, 2g of rosin glycerol ester resin, 25g of cuprous oxide, 4g of organic antifouling agent, 23g of pigment and filler, 1g of thixotropic agent-fumed silica and 20g of solvent.

[0131] Among them, 4g of the organic antifouling agent is copper pyrithione; 26g of the pigment filler specifically includes 5g of red iron oxide, 10g of zinc oxide and 8g of talcum powder; and 20g of the solvent is butyl acetate.

[0132] The preparation of the marine antifouling coating with both main chain degradation and drag reduction functions is the same as in Example 1.

[0133] Embodiment 4:

[0134] This embodiment provides a marine antifouling coating having both main chain degradation and drag reduction functions.

[0135] The preparation of polylactic acid glycolic acid copolymer polyol is the same as in Example 3.

[0136] Prepare marine antifouling coating according to the following weight ratio: (excluding cuprous oxide)

[0137] The invention comprises: 25g of marine antifouling resin having main chain degradation and drag reduction functions, 2g of rosin glycerol ester resin, 12g of organic antifouling agent, 40g of pigment and filler, 1g of thixotropic agent-fumed silica and 20g of solvent.

[0138] Among them, 12g of the organic antifouling agent is a (4,5-dichloro-N-octyl-4-isothiazoline-3-one) isothiazolinone derivative; 44g of the color filler specifically includes 10g of red iron oxide, 10g of zinc oxide and 20g of barium sulfate; and 20g of the solvent is ethyl acetate.

[0139] The preparation of the marine antifouling coating with both main chain degradation and drag reduction functions is the same as in Example 1.

[0140] Embodiment 5:

[0141] This embodiment provides a marine antifouling coating having both main chain degradation and drag reduction functions.

[0142] Preparation of polylactic acid glycolic acid copolymer polyol:

[0143] a) 61.4 g (0.6 mol) of lactic acid with a mass concentration of 88%, 50.7 g (0.3 mol) of glycolic acid with a mass concentration of 60%, 5.2 g (0.05 mol) of neopentyl glycol and 0.6 g of zinc acetate were added to a reactor, the oil bath was heated to 185° C., the temperature of the top of the fractionation tower was maintained at 100-105° C., and the reaction was carried out for 3 hours; then the temperature was kept at 220° C. for 2 hours;

[0144] b) evacuating the mixture and gradually increasing the degree of vacuum to remove trace amounts of water and excess ethylene glycol under reduced pressure until the acid value of the synthesized product is lower than 5 mgKOH / g, thereby obtaining a waxy poly(lactic acid-co-glycolic acid) copolymer polyol;

[0145] c) Add 6 g of terminal alcohol hydroxy silicone oil, stir for 1 hour, cool to 70°C, add 10 g of butyl acetate and 5 g of xylene to dissolve, then add 4 g of isophorone diisocyanate (IPDI) dropwise, and after titration, continue the reaction for 2 hours to obtain a marine antifouling resin (solid content 82±2%) with both main chain degradation and drag reduction functions.

[0146] Prepare marine antifouling coating according to the following weight ratio:

[0147] The invention comprises: 22g of marine antifouling resin having main chain degradation and drag reduction functions, 4g of hydrogenated rosin resin, 25g of cuprous oxide, 4g of organic antifouling agent, 24g of pigment and filler, 1g of thixotropic agent - fumed silica and 20g of solvent.

[0148] Among them, 4g of the organic antifouling agent is copper pyrithione; 24g of the pigment filler specifically includes 5g of red iron oxide, 10g of zinc oxide and 9g of talcum powder; and 20g of the solvent is butyl acetate.

[0149] The preparation of the marine antifouling coating with both main chain degradation and drag reduction functions is the same as in Example 1.

[0150] Embodiment 6:

[0151] This embodiment provides a marine antifouling coating having both main chain degradation and drag reduction functions.

[0152] The preparation of polylactic acid glycolic acid copolymer polyol is the same as in Example 5.

[0153] Prepare marine antifouling coating according to the following weight ratio: (excluding cuprous oxide)

[0154] The invention comprises: 22g of marine antifouling resin having main chain degradation and drag reduction functions, 4g of hydrogenated rosin resin, 12g of organic antifouling agent, 41g of pigment and filler, 1g of thixotropic agent - fumed silica and 20g of solvent.

[0155] Among them, 12g of the organic antifouling agent is a (4,5-dichloro-N-octyl-4-isothiazoline-3-one) isothiazolinone derivative; 41g of the color filler specifically includes 10g of red iron oxide, 10g of zinc oxide and 21g of barium sulfate; 20g of the solvent includes 10g of ethyl acetate and 10g of butyl acetate.

[0156] The preparation of the marine antifouling coating with both main chain degradation and drag reduction functions is the same as in Example 1.

[0157] Comparative Example 1:

[0158] This comparative example provides a marine antifouling coating.

[0159] Preparation of polylactic acid polyol:

[0160] a) 71.6 g (0.7 mol) of lactic acid with a mass concentration of 88%, 36 g (0.35 mol) of 1,4-butanediol and 0.2 g of stannous octoate were added to a reactor, the oil bath was heated to 180°C, the temperature of the top of the fractionation tower was maintained at 100-105°C, and the reaction was carried out for 3 hours; then the temperature was kept at 200°C for 1 hour;

[0161] b) evacuating the mixture and gradually increasing the degree of vacuum to remove trace amounts of water and excess ethylene glycol under reduced pressure until the acid value of the synthesized product is lower than 5 mgKOH / g, thereby obtaining a waxy polylactic acid polyol;

[0162] c) adding 5 g of terminal alcohol hydroxy silicone oil to the polylactic acid polyol obtained in step b), stirring for 1 h, cooling to 80° C., adding 10 g of butyl acetate and 8 g of xylene for dissolution, and then dropping 2 g of toluene diisocyanate. After the titration is completed, continuing the reaction for 1 h to obtain a marine antifouling resin (solid content 80±2%) having both main chain degradation and drag reduction functions.

[0163] Prepare marine antifouling coating according to the following weight ratio:

[0164] The invention comprises: 22g of marine antifouling resin having main chain degradation and drag reduction functions, 4g of horsetail rosin resin, 25g of cuprous oxide, 3g of organic antifouling agent, 25g of pigment and filler, 1g of thixotropic agent - organic bentonite and 20g of solvent.

[0165] Among them, 3g of the organic antifouling agent is copper pyrithione; 25g of the pigment filler specifically includes 5g of red iron oxide, 5g of zinc oxide and 15g of talcum powder; and 20g of the solvent is butyl acetate.

[0166] The preparation of marine antifouling coating is the same as in Example 1.

[0167] Comparative Example 2

[0168] This comparative example provides a marine antifouling coating.

[0169] Preparation of polylactic acid glycolic acid copolymer polyol:

[0170] a) 61.4 g (0.6 mol) of lactic acid with a mass concentration of 88%, 50.7 g (0.3 mol) of glycolic acid with a mass concentration of 60%, 10.4 g (0.1 mol) of malonic acid, 14.4 g (0.16 mol) of 1,4-butanediol and 0.4 g of stannous octoate were added to a reactor, the oil bath was heated to 190°C, the temperature of the top of the fractionation tower was maintained at 100-105°C, and the reaction was carried out for 4 hours; then the temperature was kept at 210°C for 2 hours;

[0171] b) evacuating the mixture and gradually increasing the degree of vacuum to remove trace amounts of water and excess ethylene glycol under reduced pressure until the acid value of the synthesized product is lower than 5 mgKOH / g, thereby obtaining a waxy poly(lactic acid-co-glycolic acid) copolymer polyol;

[0172] c) adding 15 g of butyl acetate and 5 g of xylene to dissolve the mixture, thereby obtaining a main chain degradable marine antifouling resin (solid content 80±2%).

[0173] Prepare marine antifouling coating according to the following weight ratio:

[0174] The invention comprises: 22g of main chain degradable marine antifouling resin, 5g of rosin glycerol ester resin, 25g of cuprous oxide, 4g of organic antifouling agent, 23g of pigment and filler, 1g of thixotropic agent-fumed silica and 20g of solvent.

[0175] Among them, 4g of the organic antifouling agent is copper pyrithione; 26g of the pigment filler specifically includes 5g of red iron oxide, 8g of zinc oxide and 10g of talcum powder; and 20g of the solvent is butyl acetate.

[0176] The preparation of marine antifouling coating is the same as in Example 1.

[0177] Long-term and firm adhesion to the surface of the substrate is a prerequisite for the marine antifouling coating to exert its antifouling effect, so the coating adhesion strength is one of the important indicators for testing the quality of the marine antifouling coating; the antifouling coating prepared by the present invention may have a certain effect on the adhesion of the coating due to the addition of some silicone oil. The 8 marine antifouling coatings prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were tested for their adhesion strength in accordance with the GB / T 1720-2020 standard, where the substrate was a mark iron sheet coated with an epoxy zinc-rich primer. As shown in Table 1, the antifouling coatings prepared in Examples 1 to 6 and Comparative Examples 1 to 2 had an adhesion strength of more than 1 MPa, which fully met the use requirements of marine antifouling coatings.

[0178] Table 1. Adhesion of coatings.

[0179] Adhesion strength (MPa) Example 1 1.3±0.1 Example 2 1.4±0.1 Example 3 1.2±0.1 Example 4 1.3±0.1 Example 5 1.7±0.1 Example 6 1.7±0.1 Comparative Example 1 1.3±0.1 Comparative Example 2 2.2±0.1

[0180] Surface energy is an important factor affecting the drag reduction performance of marine antifouling coatings. Low surface energy can prevent the initial attachment of marine organisms and reduce the resistance generated during the navigation of ships, thus achieving a drag reduction effect. Studies have shown that the surface energy between liquids and solids has a certain correlation with the contact angle. The larger the contact angle, the lower the surface energy; conversely, the higher the surface energy. The eight marine antifouling coatings prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were tested for their surface energy with reference to the contact angle method in ISO 8296 standard; as shown in Table 2, the surface energies of the antifouling coatings prepared in Examples 1 to 6 and Comparative Example 1 were all lower than 27 mJ / m 2, has low surface energy characteristics, can play a drag reduction effect, wherein the silicone oil content in Example 3 and Example 4 is higher, and its surface energy is also lower; as a comparison, in Comparative Example 2, no alcohol hydroxy silicone oil component is added, and the surface energy of the self-polishing antifouling coating obtained is 30mJ / m 2 The above is difficult to achieve the effect of drag reduction.

[0181] Table 2. Surface energies of coatings.

[0182] <![CDATA[Surface energy (mJ / m 2 )]]> Example 1 26.6±0.1 Example 2 26.2±0.1 Example 3 24.2±0.1 Example 4 23.8±0.1 Example 5 25.5±0.1 Example 6 25.3±0.1 Comparative Example 1 26.3±0.1 Comparative Example 2 30.6±0.1

[0183] The marine antifouling coatings prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were subjected to shallow sea immersion tests in accordance with the national standard GB / T5370-2007 "Shallow Sea Immersion Test Method for Antifouling Paint Samples". The test location was Xiamen 725 Board Hanging Base, and the test time was from May 5, 2022 to July 25, 2023. The results are as follows: Figure 1 As shown, from left to right are Example 1, Example 2, Example 3, Example 4, Example 5, Example 6, Comparative Example 1 and Comparative Example 2. The results are as follows Figure 1 As shown, after 1 year of shallow sea immersion test, the surfaces of the samples of Examples 1 to 6 are still smooth, with basically no marine organisms attached, and have good antifouling performance; in Comparative Example 1, since no glycolic acid monomer is added to adjust the degradation rate of the resin, after 1 year, the coating surface has slight marine organisms attached; in Comparative Example 2, since no alcohol hydroxy silicone oil component is added, after 1 year, although there is no marine organism attached to the coating surface, the coating surface is a little rough. The operation method of the present invention is simple, low-cost, suitable for industrial production, and has broad application prospects.

[0184] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A marine antifouling coating with both backbone degradation and drag reduction functions, It is characterized in that The marine antifouling paint comprises the following components in percentage by weight:

2. A marine antifouling coating having both main chain degradation and drag reduction functions according to claim 1, It is characterized in that The structure of the marine antifouling resin having both main chain degradation and drag reduction functions is shown in the following formula (I): Wherein, m and n are integers; The structure represented by R is shown in the following formula (II): Where x, y and z are integers; R 1 represents an alkyl group or an aryl group having 1 or more carbon atoms; R 2 represents an alkyl group or an aryl group having 1 or more carbon atoms; R' represents an alkyl group or an aryl group having 1 or more carbon atoms; R 3 It represents an alkyl group with 1 or more C atoms; R 4 It represents one of a methyl group, a hydroxy group, an amino group or an alcoholic hydroxy group.

3. A marine antifouling coating having both main chain degradation and drag reduction functions according to claim 2, It is characterized in that The method for preparing the marine antifouling resin having both main chain degradation and drag reduction functions comprises the following steps: a) Under nitrogen protection, subjecting lactic acid, glycolic acid, polyacid, polyol compound and catalyst to esterification and polycondensation reaction, removing byproduct water at normal pressure, and then keeping warm; b) evacuating the mixture and gradually increasing the degree of vacuum to remove trace amounts of water and excess polyol compounds under reduced pressure until the acid value of the synthesized product is lower than 5 mgKOH / g, thereby obtaining poly(lactic acid-co-glycolic acid) copolymer polyol; c) adding terminal alcohol hydroxy silicone oil to the polylactic acid glycolic acid copolymer polyol obtained in step b), continuing stirring, cooling, adding solvent B to dissolve, dropping the isocyanate compound, and after the dropping is completed, continuing the reaction to obtain a marine antifouling resin with both main chain degradation and drag reduction functions.

4. A marine antifouling coating having both main chain degradation and drag reduction functions according to claim 3, It is characterized in that The polyacid in step a) includes one or more of oxalic acid, terephthalic acid, succinic acid and adipic acid; or, The polyol compound in step a) includes one or more of an aliphatic polyol compound and a polyether polyol; or, Step a) the glycolic acid accounts for 10 to 80% of all monomers by mass; The molecular weight of the polylactic acid glycolic acid copolymer polyol is 1000 to 30000; The catalyst in step a) includes one or more of stannous octoate, stannous chloride, tetrabutyl titanate, zinc acetate, antimony acetate, antimony trioxide and antimony glycolate; or, Step a) The amount of the catalyst is 0.01-2 wt% of the mass of glycolic acid; In step c), the solvent B is one or more of toluene, xylene, ethyl acetate, butyl acetate and methyl isobutyl ketone. The isocyanate compound in step c) is one or more of an adduct of toluene diisocyanate and trimethylolpropane, hexamethylene diisocyanate trimer, isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and toluene diisocyanate dimer.

5. A marine antifouling coating having both backbone degradation and drag reduction functions according to claim 1, It is characterized in that The other resins include one or more of horsetail rosin, hydrogenated rosin, rosin glycerol ester, self-polishing acrylate resin and polyurethane resin.

6. A marine antifouling coating having both backbone degradation and drag reduction functions according to claim 1, It is characterized in that The organic antifouling agent includes one or more of copper pyrithione, mancozeb, and (4,5-dichloro-N-octyl-4-isothiazoline-3-one)isothiazolinone derivatives.

7. A marine antifouling coating having both backbone degradation and drag reduction functions according to claim 1, It is characterized in that The pigments and fillers include one or more of nano silicon dioxide, polytetrafluoroethylene, zinc oxide, calcium carbonate, talcum powder, diatomaceous earth, mica powder, titanium dioxide, antimony oxide, barium sulfate and red iron oxide.

8. A marine antifouling coating having both main chain degradation and drag reduction functions according to claim 1, It is characterized in that The thixotropic agent includes one or more of organic bentonite, fumed silica, cellulose ethers and polyamide wax.

9. A marine antifouling coating having both backbone degradation and drag reduction functions according to claim 1, It is characterized in that The solvent A is one or more of toluene, xylene, ethyl acetate, butyl acetate and methyl isobutyl ketone.

10. A method for preparing a marine antifouling coating having both main chain degradation and drag reduction functions as claimed in any one of claims 1 to 9, It is characterized in that The preparation method comprises the following steps: (1) According to the ratio, firstly, solvent A is stirred at a speed of 500 to 1000 r / min, and the marine antifouling resin and other resins having both main chain degradation and drag reduction functions are added until the resin is completely dissolved; (2) adding a thixotropic agent, continuing stirring, and then adding cuprous oxide, pigments and fillers, and an organic antifouling agent, dispersing at a speed of 2000 to 3000 r / min for 30 to 60 minutes to obtain the marine antifouling coating having both main chain degradation and drag reduction functions.

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