CN113214434B

CN113214434B - Preparation of core-shell acrylic acid antifouling resin and application of core-shell acrylic acid antifouling resin in copper-free antifouling paint

Info

Publication number: CN113214434B
Application number: CN202110413868.4A
Authority: CN
Inventors: 胡建坤; 张庆华; 詹晓力
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2021-04-16
Filing date: 2021-04-16
Publication date: 2022-04-01
Anticipated expiration: 2041-04-16
Also published as: CN113214434A

Abstract

The invention relates to a coating technology, and aims to provide preparation of a core-shell acrylic antifouling resin and application of the core-shell acrylic antifouling resin in a copper-free antifouling coating. The method comprises the following steps: dripping mixed liquid containing methyl acrylate, acrylic acid, acrylamide, span, AIBN and azobisisovaleronitrile into the mixed liquid of azodiisobutyronitrile, xylene, ethylene glycol monobutyl ether and span 80; then adding benzoyl peroxide, and preserving the heat at 116 ℃; dropwise adding a mixed solution containing xylene, AIBN, isopropyl methacrylate, methyl methacrylate and styrene into a reaction system; and preserving the heat for 3 hours to obtain the core-shell acrylic antifouling resin. The core of the core-shell acrylic resin is an active polymer, and can generate hydrolysis reaction when contacting with water; the shell is a specially prepared moderate hydrophobic polymer, and can control the contact of water and the active polymer in the core, thereby realizing the adjustment of the release of the active polymer; does not contain copper, belongs to an environment-friendly antifouling coating and has application potential.

Description

Preparation of core-shell acrylic acid antifouling resin and application of core-shell acrylic acid antifouling resin in copper-free antifouling paint

Technical Field

The invention relates to the technical field of coatings, in particular to preparation of core-shell acrylic acid antifouling resin and application of the core-shell acrylic acid antifouling resin in a copper-free antifouling coating.

Background

The service process of ships, marine resource development equipment and coastal engineering facilities in a severe marine environment faces serious fouling and corrosion problems, which causes huge economic loss and potential safety hazard. According to statistics, the investment for preventing and controlling marine fouling reaches 400-. Various technical measures are taken to prevent the attachment of fouling organisms, but until now, antifouling coatings are still the most economical and effective means for preventing the attachment of marine organisms.

In 2008, the global sea area forbids the use of antifouling paint containing organotin biocidal materials, and a series of self-polishing antifouling paints taking copper acrylate/zinc/silicon resin as a film forming matter and cuprous oxide as a main antifouling agent are promoted. The amount of cuprous oxide used in the mainstream self-polishing coating is relatively high, typically around 40%. Although cuprous oxide is less harmful to the environment than organic tin, the following problems are also existed: (1) copper as a heavy metal element has certain toxicity and can not be degraded, and the large accumulation of copper in oceans or harbors can cause the death of a large amount of seaweed and seriously destroy the ecological balance; (2) cu₂The final product of the O, namely the basic copper carbonate, can be deposited and accumulated on the seabed, so that the respiratory frequency of shellfish organisms such as mussels is reduced, and the growth process of the shellfish organisms is damaged. Under such a background, the antifouling paint is trending toward environment-friendly development of low-copper/copper-free and heavy metal-free bactericides.

Many of the current environmentally friendly antifouling agents can achieve effectiveness, broad spectrum and low toxicity, but their release is too fast or too slow, such as early burst release, reduction of release rate in the parking period, etc., so that their efficacy is far from being exerted. The release of the antifouling agent is controlled depending on the matrix resin, and the polymer resin used is not only a carrier for the antifouling agent but also restricts the release of the antifouling agent and the retention of the antifouling agent on the surface of the coating. The cost of the acrylic acid copper zinc resin which is used in large quantity at present is lower, but the hydrolysis speed is difficult to control, and the antifouling period is short. The controlled release effect of the acrylic silicon resin and the linear acrylate resin is good, the application is more in the middle-high end market, but the cost is higher, and the large-area popularization is not facilitated. In view of such circumstances, the present invention provides a core-shell type acrylic antifouling resin and a copper-free antifouling paint composition comprising the same.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects of the prior art and provides preparation of a core-shell acrylic antifouling resin and application of the core-shell acrylic antifouling resin in a copper-free antifouling paint.

In order to solve the technical problem, the solution of the invention is as follows:

the preparation method of the core-shell acrylic antifouling resin comprises the following steps:

(1) adding 0.2g of Azobisisobutyronitrile (AIBN), 75g of xylene, 20g of ethylene glycol monobutyl ether and 0.4g of span 80 into a 1L four-neck flask provided with a stirrer, a reflux condenser and nitrogen protection, and heating to 106 ℃;

(2) dropwise adding a mixed solution containing 70g of methyl acrylate, 25g of acrylic acid, 5g of acrylamide, 2.6g of span, 1.2g of AIBN and 0.3g of azobisisovaleronitrile into the reaction system in the step (1); after the dripping is finished at a constant speed for 3.5 hours, 0.3g of benzoyl peroxide is added, and then the temperature is raised to 116 ℃; keeping the temperature for 4h, and then cooling to 95 ℃;

(3) dropwise adding a mixed solution containing 145g of xylene, 4g of AIBN, 100g of isopropyl methacrylate (IPMA), 25g of Methyl Methacrylate (MMA) and 25g of styrene (St) into the reaction system in the step (2); after the dropwise adding is finished evenly for 3 hours, preserving the heat for 3 hours; and cooling to room temperature to obtain the core-shell acrylic antifouling resin (I).

The invention also provides a preparation method of the core-shell acrylic antifouling resin, which comprises the following steps:

(1) 0.2g of Azobisisobutyronitrile (AIBN), 75g of xylene and 20g of ethylene glycol monobutyl ether are added into a 1L four-neck flask which is provided with a stirrer, a reflux condenser and nitrogen protection; then adding 6.8g of acrylic acid, 8.2g of methacrylic acid, 6.7g of zinc oxide and 0.6g of water, and heating to 70 ℃; after reacting for 24 hours, adding a proper amount of molecular sieve to remove water, cooling and filtering, and collecting filtrate;

(2) taking 35g of methyl acrylate, 50g of ethyl acrylate, 3g of span 80, 1.2g of AIBN and 0.8g of azodiisovaleronitrile to form a mixed solution, dropwise adding the mixed solution into the filtrate obtained in the step (1) at 105 ℃, and finishing dropwise adding at a constant speed for 3.5 hours; then adding 0.3g of benzoyl peroxide, heating to 116 ℃, preserving heat for 4 hours, and cooling to 95 ℃;

(3) dropwise adding a mixed solution containing 146g of xylene, 4g of AIBN, 40g of triisopropylsilyl methacrylate, 50g of methyl acrylate and 60g of butyl methacrylate into the reaction system in the step (2); after the dropwise adding is finished evenly for 3 hours, then preserving the heat for 3 hours; and cooling to room temperature to obtain the core-shell acrylic antifouling resin (II).

(1) 0.2g of Azobisisobutyronitrile (AIBN), 75g of xylene and 20g of ethylene glycol monobutyl ether are added into a 1L four-neck flask which is provided with a stirrer, a reflux condenser and nitrogen protection; then adding 12g of acrylic acid, 6.6g of zinc oxide and 0.5g of water, and heating to 70 ℃; after reacting for 24 hours, adding a proper amount of molecular sieve to remove water, filtering and collecting filtrate;

(2) taking 30g of triisopropylsilyl methacrylate, 58g of ethyl acrylate, 3g of span 80, 1.2g of AIBN and 0.8g of azobisisovaleronitrile to form a mixed solution, dropwise adding the mixed solution into the filtrate obtained in the step (1) at the temperature of 85 ℃, and finishing the dropwise adding at a constant speed for 3.5 hours; then adding 0.3g of benzoyl peroxide, heating to 95 ℃, and keeping the temperature for 4 hours;

(3) dropwise adding a mixed solution containing 146g of xylene, 4g of AIBN, 40g of vinyl acetate, 50g of isooctyl acrylate and 60g of butyl methacrylate into the reaction system in the step (2); after 4 hours of uniform dropwise adding, then preserving heat for 3 hours; and cooling to room temperature to obtain the core-shell acrylic antifouling resin (III).

The invention further provides a formula of the copper-free antifouling paint, which comprises the following components in percentage by weight:

11-33% of core-shell acrylic antifouling resin as main resin;

6 to 9 percent of dimerized rosin and 1.5 to 3.5 percent of zinc ion controlled release resin as auxiliary resin;

1-3% of glass fiber as a reinforcing agent;

3-8% of SeaNine 211, 3-5% of zinc pyrithione and 6-10% of zineb as antifouling agents;

4-6% of iron oxide red and 12-40% of zinc oxide as pigments;

MT powder, organic bentonite or fumed silica 0.5 percent as an anti-settling thixotropic agent;

2-4% of controlled release plasticizer as an auxiliary agent;

xylene as solvent 11% and methyl isobutyl ketone 5%.

The invention also provides a formula of the copper-free antifouling paint, which comprises the following components in percentage by weight:

9-20% of core-shell acrylic antifouling resin as main resin;

4-9% of hydrogenated rosin and 4-8% of terpene resin as auxiliary resins;

1-3% of SEBS resin as a skeleton resin;

7-10% of SeaNine 2117, 6-10% of bromopyrrole nitrile, 3-6% of zinc pyrithione and 0.5% of metomidine as antifouling agents;

4-6% of iron oxide red and 8-12% of zinc oxide as pigments;

4-8% of sepiolite powder, 3-9% of wollastonite and 4-8% of talcum powder which are used as fillers;

1-4% of controlled release plasticizer as an auxiliary agent;

xylene as solvent 10.5-14% and methyl isobutyl ketone 5%.

In the invention, the preparation method of the controlled-release plasticizer comprises the following steps:

(1) adding 0.1g of AIBN and 198g of xylene into a 1L four-neck flask provided with a stirrer, a reflux condenser and nitrogen protection, and heating to 80 ℃;

(2) taking a mixed solution containing 100g of isooctyl acrylate, 40g of butyl acrylate, 60g of hydroxyethyl acrylate, 1.2g of AIBN and 0.5g of azobisisovaleronitrile AMBN, and dropwise adding the mixed solution into the reaction system in the step (1) by using a needle propeller at a constant speed for 3 hours; continuing to add 0.2g of AIBN, and then heating to 90 ℃;

(3) dropwise adding a mixed solution of 30g of methyl methacrylate, 40g of methoxyethyl acrylate, 30g of tributyl acrylate silicone grease, 5g of benzoyl peroxide and 95g of xylene into the reaction system in the step (2), and finishing dropwise adding within 4 hours;

(4) heating to 100 deg.c and maintaining for 3 hr; and cooling to room temperature to obtain the controlled-release plasticizer for the antifouling paint.

Description of the inventive principles:

a representative synthetic route for the present invention is shown in figure 1. As can be seen in fig. 1, the core-shell technique embeds the reactive polymer in the hydrophobic acrylate polymer. The core of the inner core is a polymer with high reactivity with seawater, and sodium salt is generated on the main chain of the polymer during reaction, so that the polishing process is triggered.

Polymer-COOH→Polymer-COO-Na⁺(soluble, trigger Polish)

The hydrophobic shell ensures a thin leaching layer during polishing, which reduces the diffusion resistance and facilitates the effective concentration of the active ingredient. The core-shell technology can strictly control the release of the antifouling agent in the formula and ensure that the antifouling agent can be released in a balanced manner in the polishing process, so that the service life of the coating is ensured in the whole service period. Compared with the zinc acrylate antifouling resin based on the ion exchange technology, the technology greatly enhances the controlled release capability of the antifouling agent, and effectively avoids the problem that the coating loses the antifouling capability prematurely due to sudden release and uneven release of the antifouling agent. Compared with the existing commonly used high-performance acrylic silicon antifouling resin, the resin prepared by the technology basically achieves the antifouling capability of the acrylic silicon resin, has lower production cost, and is a new technology with application potential (the detailed experimental result is shown in specific examples).

Compared with the prior art, the invention has the beneficial effects that:

1. the core-shell acrylic antifouling resin provided by the invention has low cost, basically reaches the level of acrylic copper-zinc resin, and is beneficial to large-scale popularization;

2. the core-shell acrylic resin has an active polymer as an inner core, and can generate hydrolysis reaction when contacting water; the shell is a specially prepared moderate hydrophobic polymer, and can control the contact of water and the active polymer in the core, thereby realizing the adjustment of the release of the active polymer;

3. the invention does not contain copper, belongs to an environment-friendly antifouling coating and has great application potential;

4. the invention adopts D113 resin, enhances the enrichment effect of zinc ions, is beneficial to maintaining the high concentration of the zinc ions on the surface of the coating and improves the antifouling effect;

5. the invention adopts the controlled release plasticizer, which can not only plasticize but also control release; compared with the traditional plasticizer butyl phthalate, the antifouling property is greatly improved.

Drawings

FIG. 1 is a representative synthesis scheme for core-shell acrylic antifouling resins.

Detailed Description

Firstly, synthesis of core-shell polymer (I):

0.2g of Azobisisobutyronitrile (AIBN), 75g of xylene, 20g of ethylene glycol monobutyl ether and 0.4g of span 80 are added into a 1L four-neck flask provided with a stirrer, a reflux condenser and nitrogen protection, the temperature is raised to 106 ℃, then mixed liquid containing 70g of methyl acrylate, 25g of acrylic acid, 5g of acrylamide, 2.6g of span, 1.2g of AIBN and 0.3g of azobisisovaleronitrile is weighed, after the constant dropping for 3.5 hours, 0.3g of benzoyl peroxide is added, then raising the temperature to 116 ℃, keeping the temperature for 4h, then lowering the temperature to 95 ℃, then weighing a mixed solution containing 145g of xylene, 4g of AIBN, 100g of isopropyl methacrylate (IPMA), 25g of Methyl Methacrylate (MMA) and 25g of styrene (St), uniformly dropwise adding the mixed solution after 3 h, then, after keeping the temperature for 3 hours, cooling to room temperature to obtain the core-shell acrylic antifouling resin (I). The measured solid content is 51.8%; the emulsion particle size is most distributed around 620nm by the detection of a laser particle sizer; the resin had a number average molecular weight of 19587, a weight average molecular weight of 55117 and a dispersity of 2.814 by GPC.

Secondly, synthesis of core-shell polymer (II):

adding 0.2g of Azobisisobutyronitrile (AIBN), 75g of xylene and 20g of ethylene glycol monobutyl ether into a 1L four-neck flask provided with a stirrer, a reflux condenser and nitrogen protection, then adding 6.8g of acrylic acid, 8.2g of methacrylic acid, 6.7g of zinc oxide and 0.6g of water, heating to 70 ℃, reacting for 24 hours, adding a proper amount of molecular sieve to remove water, cooling, filtering, collecting filtrate, then adding 35g of methyl acrylate, 50g of ethyl acrylate, 3g of span 80, 1.2g of AIBN and 0.8g of azobisisovaleronitrile into the mixture to form a mixed solution, adding 0.3g of benzoyl peroxide after 3.5 hours of constant-speed dropwise addition under the condition of 105 ℃, heating to 116 ℃, keeping the temperature for 4 hours, cooling to 95 ℃, then weighing the mixed solution containing 146g of xylene, 4g of AIBN, 40g of triisopropylsilicate methacrylate, 50g of methyl acrylate and 60g of butyl methacrylate, and after the uniform dropwise addition is finished for 3 hours, preserving the heat for 3 hours, and cooling to room temperature to obtain the core-shell acrylic antifouling resin (II). The measured solid content is 55.9%; the emulsion particle size is most distributed around 830nm by the detection of a laser particle sizer; the resin had a number average molecular weight of 14587, a weight average molecular weight of 47349 and a dispersity of 3.246 by GPC.

Thirdly, synthesis of core-shell polymer (III):

adding 0.2g of Azobisisobutyronitrile (AIBN), 75g of xylene and 20g of ethylene glycol monobutyl ether into a 1L four-neck flask provided with a stirrer, a reflux condenser and nitrogen protection, then adding 12g of acrylic acid, 6.6g of zinc oxide and 0.5g of water, heating to 70 ℃, reacting for 24 hours, adding a proper amount of molecular sieve for removing water, filtering, collecting filtrate, then adding 30g of triisopropylsilyl methacrylate, 58g of ethyl acrylate, 3g of span 80, 1.2g of AIBN and 0.8g of azobisisovaleronitrile into the mixture, adding 0.3g of benzoyl peroxide after finishing dropping at a constant speed of 3.5 hours at the temperature of 85 ℃, heating to 95 ℃, preserving heat for 4 hours, then weighing the mixture containing 146g of xylene, 4g of AIBN, 40g of vinyl acetate, 50g of isooctyl acrylate and 60g of butyl methacrylate, uniformly dropping after 4 hours, preserving heat for 3 hours, and cooling to room temperature to obtain the core-shell acrylic antifouling resin (III). The measured solid content is 54.8%; the emulsion particle size is most distributed around 760nm by the detection of a laser particle sizer; the resin had a number average molecular weight of 12673, a weight average molecular weight of 42682, and a degree of dispersion of 3.368, as determined by GPC.

Fourthly, synthesis of controlled release plasticizer

Adding 0.1g of AIBN and 198g of xylene into a 1L four-neck flask provided with a stirrer, a reflux condenser tube and nitrogen protection, heating to 80 ℃, then weighing a mixed solution containing 100g of isooctyl acrylate, 40g of butyl acrylate, 60g of hydroxyethyl acrylate, 1.2g of AIBN and 0.5g of azobisisovaleronitrile AMBN, dropwise adding 0.2g of AIBN by using a needle propeller at a constant speed for 3 hours, then heating to 90 ℃, dropwise adding a mixed solution containing 30g of methyl methacrylate, 40g of methoxyethyl acrylate, 30g of tributyl silicone acrylate, 5g of benzoyl peroxide and 95g of xylene within 4 hours, then heating to 100 ℃, preserving heat for 3 hours, and cooling to room temperature to obtain the antifouling paint controlled-release plasticizer.

Five, copper-free antifouling paint composition I (economic type)

Copper-free antifouling coating composition one (economy) is shown in the following table:

the total amount of the components is 100 percent. The zinc ion controlled release resin has a binding effect on zinc ions and can play a slow release effect on the zinc ions, such as D113 resin, vanillin-chitosan resin and the like.

The controlled-release plasticizer is a resin capable of performing a controlled-release plasticizing effect prepared in example 4, and is used to replace a conventional plasticizer. The same is as follows.

The economic antifouling paint comprises the following components in percentage by weight:

note: performing antifouling paint hanging plate test in Zhoushan snail sea area (30 degrees 01'N and 122 degrees 06' E); the MT powder is Achima CRAYVALLAC polyamide modified hydrogenated castor oil; DBP is dibutyl phthalate; in the one-year antifouling evaluation, the fouling organism attachment ratio was preferably 10% or less, more preferably 10 to 20% or less, and less preferably 20% or more. The same is as follows.

Columns 10-12 of the table above are comparative examples to examples 1-9, the formulation of which uses the conventional plasticizer DBP (dibutyl phthalate). It can be seen from the test data of the comparative example that the antifouling evaluation result is better than that of the traditional plasticizer DBP by further adding the controlled release plasticizer on the basis of the application of the core-shell type antifouling resin.

Introduction of comparative example 10C:

on the basis of the paint formulation described in example 10, the applicant further prepared a comparative sample 10C using an economical zinc acrylate antifouling resin (zinc acrylate resin H60Z produced by hengtai paint industries ltd, zhou shan) sold on the market instead of the core-shell type antifouling resin i, and used it for antifouling paint hanging plate testing. After one year of hanging plates on the actual sea, the biological attachment rate of the sample is 41%, and the evaluation result is poor. While the antifouling effect (19%) of example 10 is relatively much better than that (41%) of comparative example 10C, indicating that the antifouling performance of the core-shell type acrylic antifouling resin is much better than that of the conventional zinc acrylate antifouling resin.

Samples of the coatings of examples 1-2, 5-7 were randomly drawn and tested for basic mechanical properties as follows:

inspection item	Results of actual measurement in examples 1-2 and 5-7	Inspection method
			Adhesion/grade	2	GB/T1720-1979
Impact resistance/(kg. cm)	≥40	GB/T1732-93
			Flexibility/mm	≤2	GB/T1731-79
Salt water resistance (Normal temperature, 14d)	No bubbling, no falling and no change of coating	GB/T10834-2008
			Storage stability (50, 30d)	Qualified	GB/T6753.3-1986
Storage stability (Room temperature, 9 months)	Qualified	GB/T6753.3-1986

Sixthly, copper-free antifouling paint composition II (high performance)

The copper-free antifouling paint composition two is shown in the following table:

the total amount of the components is 100 percent. The skeleton resin is butadiene-modified styrene-butadiene resin (SEBS resin); the terpene resin can be T100 or T105 terpene resin;

a representative antifouling paint formulation consists of:

note: SEBS is butadiene-modified styrene-butadiene resin (taiwan tai rubber); MT powder is polyamide modified hydrogenated castor oil (Acoma CRAYVALLAC)

Introduction of comparative example 22C:

on the basis of the paint formulation described in example 22, the applicant further replaced the core-shell type antifouling resin i of this example with a commercially available high-performance acrylic silicone antifouling resin (acrylic silicone resin SPSi-100 produced by yao-shi cheng chemicals ltd.) to prepare a comparative sample 22C, which was used for the antifouling paint suspending board test. After one year of the live sea hanging plate, the bioadhesion rate of the comparative sample 22C was 2%, and the evaluation result was excellent. The antifouling effect (3%) of the sample in example 22 is substantially equivalent to that of the sample in comparative example 22C (2%), which shows that the antifouling performance of the core-shell type antifouling acrylic resin substantially reaches the level of the antifouling acrylic silicone resin, but the cost is low (the antifouling performance of the acrylic silicone resin is more than or equal to 80 yuan/kg, and the antifouling performance of the core-shell type antifouling resin is less than or equal to 30 yuan/kg), so that the product of the invention has market competitiveness relatively.

Introduction of comparative example 22D:

on the basis of the paint formulation described in example 22, the applicant further prepared a comparative sample 22D by replacing the core-shell type antifouling resin i in this example with an economical zinc acrylate antifouling resin (zinc acrylate resin H60Z manufactured by hengtai paint industries ltd, zhou shan) on the market, and used it for antifouling paint hanging plate test. After one year of the live sea wall plate, the bio-adhesion rate of the comparative sample 22D was 14%, and the evaluation result was good. The antifouling effect (3%) of the sample in example 22 of the present invention is much better than that of the comparative sample 22D (14%), indicating that the antifouling property of the core-shell acrylic antifouling resin of the present invention is very excellent.

Samples of the coatings of examples 21-23, 27-29 were randomly drawn and tested for basic mechanical properties as follows:

Claims

1. the copper-free antifouling paint is characterized by comprising the following components in percentage by weight:

11-33% of core-shell acrylic antifouling resin as main resin;

1-3% of glass fiber as a reinforcing agent;

4-6% of iron oxide red and 12-40% of zinc oxide as pigments;

0.5 percent of organic bentonite or fumed silica used as an anti-settling thixotropic agent;

2-4% of controlled release plasticizer as an auxiliary agent;

xylene 11% and methyl isobutyl ketone 5% as solvents;

the core-shell acrylic antifouling resin as the main resin is prepared by any one of the following methods:

(1) the first scheme specifically comprises the following steps:

(1.1) adding 0.2g of Azobisisobutyronitrile (AIBN), 75g of xylene, 20g of ethylene glycol monobutyl ether and 0.4g of span 80 into a 1L four-neck flask which is provided with a stirrer, a reflux condenser and nitrogen protection, and heating to 106 ℃;

(1.2) dropwise adding a mixed solution containing 70g of methyl acrylate, 25g of acrylic acid, 5g of acrylamide, 2.6g of span, 1.2g of AIBN and 0.3g of azobisisovaleronitrile into the reaction system in the step (1); after the dripping is finished at a constant speed for 3.5 hours, 0.3g of benzoyl peroxide is added, and then the temperature is raised to 116 ℃; keeping the temperature for 4h, and then cooling to 95 ℃;

(1.3) adding a mixed solution containing 145g of xylene, 4g of AIBN, 100g of isopropyl methacrylate IPMA, 25g of methyl methacrylate MMA and 25g of styrene (St) dropwise into the reaction system in the step (2); after the dropwise adding is finished evenly for 3 hours, preserving the heat for 3 hours; cooling to room temperature to obtain the core-shell acrylic acid antifouling resin (I);

(2) the second scheme specifically comprises the following steps:

(2.1) adding 0.2g of Azobisisobutyronitrile (AIBN), 75g of xylene and 20g of ethylene glycol monobutyl ether into a 1L four-neck flask which is provided with a stirrer, a reflux condenser and nitrogen protection; then adding 6.8g of acrylic acid, 8.2g of methacrylic acid, 6.7g of zinc oxide and 0.6g of water, and heating to 70 ℃; after reacting for 24 hours, adding a proper amount of molecular sieve to remove water, cooling and filtering, and collecting filtrate;

(2.2) taking 35g of methyl acrylate, 50g of ethyl acrylate, 3g of span 80, 1.2g of AIBN and 0.8g of azobisisovaleronitrile to form a mixed solution, dropwise adding the mixed solution into the filtrate obtained in the step (1) at the temperature of 105 ℃, and finishing the dropwise adding at a constant speed for 3.5 hours; then adding 0.3g of benzoyl peroxide, heating to 116 ℃, preserving heat for 4 hours, and cooling to 95 ℃;

(2.3) dropwise adding a mixed solution containing 146g of xylene, 4g of AIBN, 40g of triisopropylsilyl methacrylate, 50g of methyl acrylate and 60g of butyl methacrylate into the reaction system in the step (2); after the dropwise adding is finished evenly for 3 hours, then preserving the heat for 3 hours; cooling to room temperature to obtain core-shell acrylic acid antifouling resin (II);

(3) the third scheme specifically comprises the following steps:

(3.1) adding 0.2g of Azobisisobutyronitrile (AIBN), 75g of xylene and 20g of ethylene glycol monobutyl ether into a 1L four-neck flask which is provided with a stirrer, a reflux condenser and nitrogen protection; then adding 12g of acrylic acid, 6.6g of zinc oxide and 0.5g of water, and heating to 70 ℃; after reacting for 24 hours, adding a proper amount of molecular sieve to remove water, filtering and collecting filtrate;

(3.2) taking 30g of triisopropylsilyl methacrylate, 58g of ethyl acrylate, 3g of span 80, 1.2g of AIBN and 0.8g of azobisisovaleronitrile to form a mixed solution, dropwise adding the mixed solution into the filtrate obtained in the step (1) at the temperature of 85 ℃, and finishing the dropwise adding at a constant speed for 3.5 hours; then adding 0.3g of benzoyl peroxide, heating to 95 ℃, and keeping the temperature for 4 hours;

(3.3) dropwise adding a mixed solution containing 146g of xylene, 4g of AIBN, 40g of vinyl acetate, 50g of isooctyl acrylate and 60g of butyl methacrylate into the reaction system in the step (2); after 4 hours of uniform dropwise adding, then preserving heat for 3 hours; cooling to room temperature to obtain core-shell acrylic acid antifouling resin (III);

the preparation method of the controlled-release plasticizer used as the auxiliary agent comprises the following steps:

(2) dropwise adding a mixed solution containing 100g of isooctyl acrylate, 40g of butyl acrylate, 60g of hydroxyethyl acrylate, 1.2g of AIBN and 0.5g of AMBN into the reaction system in the step (1) by using a needle propeller at a constant speed for 3 hours; continuing to add 0.2g of AIBN, and then heating to 90 ℃;

2. The copper-free antifouling paint is characterized by comprising the following components in percentage by weight: