CN113563795B

CN113563795B - Anti-fouling coating and preparation method and application thereof

Info

Publication number: CN113563795B
Application number: CN202110773991.7A
Authority: CN
Inventors: 汪黎明; 张磊
Original assignee: Guangzhou University
Current assignee: Guangzhou University
Priority date: 2021-07-08
Filing date: 2021-07-08
Publication date: 2022-07-12
Anticipated expiration: 2041-07-08
Also published as: CN113563795A

Abstract

The invention discloses an anti-fouling coating and a preparation method and application thereof, wherein the preparation method of the anti-fouling coating comprises the following steps: firstly, heating hydroxyl silicone oil to obtain pretreated hydroxyl silicone oil; and mixing the pretreated hydroxyl silicone oil with a silane coupling agent and a catalyst, and reacting to obtain the anti-fouling coating. The invention carries out heating pretreatment on the hydroxyl silicone oil, so that the hydroxyl silicone oil and the silane coupling agent, the catalyst and the like generate physical and chemical crosslinking reaction in a semi-finished product state to obtain the silicon-based anti-fouling coating, and the material has excellent anti-graffiti performance, mechanical property and stronger adhesion.

Description

Anti-fouling coating and preparation method and application thereof

Technical Field

The invention relates to the technical field of anti-fouling, in particular to an anti-fouling coating and a preparation method and application thereof.

Background

Graffiti is seen in most towns around the world, and how to eliminate graffiti is a difficult problem. In protecting public places and historic buildings, removing graffiti requires a significant financial expenditure from local governments and agencies. If a protective layer is coated on the surface of a base material to be protected, the effect of preventing graffiti and removing the graffiti after the graffiti is drawn can be achieved, the problem of inundation of the graffiti can be effectively solved, and a certain space is provided for graffiti enthusiasts.

The traditional anti-doodling mode mainly comprises three types, namely: (1) the sacrificial anti-graffiti material is widely used but has higher cost and needs to be repeatedly coated; (2) semi-permanent graffiti-resistant materials, such as acrylic or epoxy resins or polyurethane coatings, resist multiple graffiti, but as the residence time of the graffiti on the surface of the coating increases, the degree of intrusion of the graffiti into the coating increases and eventually is difficult to remove; (3) the permanent anti-graffiti material has long service life and is easy to clean, and typical materials comprise fluororesin and organic silicon resin. The raw materials of the fluororesin are expensive and have certain toxicity; the organosilicon material has the characteristic of environmental friendliness.

The alkyl-terminated or hydroxyl-terminated Polydimethylsiloxane (PDMS) is a common organic silicon anti-fouling material, has the characteristics of low surface energy, adjustable elastic modulus, low surface roughness and the like, can effectively reduce the adhesion of the graffiti coating to a solid substrate, and can be easily removed from the surface under the action of water flow or external force. However, the molecular chain segment of PDMS is composed of Si-O repeating units, and simultaneously, two organic groups are connected to each Si, and the methyl group of the side chain can effectively reduce the surface energy, which is not beneficial to the long-time adhesion of the graffiti paint.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a preparation method of the anti-fouling coating, and the prepared anti-fouling coating is relatively low in cost, good in graffiti resistance, excellent in mechanical property and strong in adhesive force.

Meanwhile, the invention also provides the anti-fouling coating prepared by the preparation method and application thereof.

Specifically, the invention adopts the following technical scheme:

the first aspect of the invention provides a preparation method of an anti-fouling coating, which comprises the following steps:

heating the hydroxyl silicone oil to obtain pretreated hydroxyl silicone oil;

and mixing the pretreated hydroxyl silicone oil with a silane coupling agent and a catalyst, and reacting to obtain the anti-fouling coating.

The preparation method of the antifouling paint according to the first aspect of the invention has at least the following beneficial effects:

the invention carries out heating pretreatment on the hydroxyl silicone oil, so that the hydroxyl silicone oil and the silane coupling agent, the catalyst and the like generate physical and chemical crosslinking reaction in a semi-finished product state to obtain the silicon-based anti-fouling coating, and the material has excellent anti-graffiti performance, mechanical property and stronger adhesion.

In some embodiments of the present invention, the temperature for heating the hydroxyl silicone oil is 50 to 150 ℃, preferably 70 to 130 ℃. The time of the heating treatment is 0.01 to 20 hours, preferably 0.5 to 8 hours, and more preferably 1 to 3 hours.

In some embodiments of the invention, the hydroxy silicone oil has a viscosity of 500 to 30000mpa.s at 25 ℃.

In some embodiments of the present invention, the mass ratio of the hydroxyl silicone oil to the silane coupling agent is 0.01 to 99:1, preferably 0.1 to 10:1, and further preferably 0.5 to 10:1, and more preferably 1 to 5: 1.

In some embodiments of the present invention, the mass ratio of the polyhydroxy silicone oil to the catalyst is 1:0.0001 to 0.1, preferably 1:0.001 to 0.1.

In some embodiments of the present invention, the method for preparing the anti-fouling coating further comprises the step of adding an auxiliary agent, wherein the auxiliary agent is mixed with the pretreated hydroxyl silicone oil and the silane coupling agent before the catalyst is added.

In some embodiments of the present invention, the anti-fouling coating is prepared by a process more specifically comprising:

heating the hydroxyl silicone oil to obtain pretreated hydroxyl silicone oil;

cooling to 20-80 ℃, adding a silane coupling agent, reacting for 0.01-10 h, adding an auxiliary agent, and stirring for reacting for 0.01-10 h to obtain a mixed solution;

and adding a catalyst into the mixed solution for catalytic reaction for 0.01-10 h to obtain the anti-fouling coating.

In some embodiments of the invention, the silane coupling agent is a compound having three OR more OR OR NR in the formula_2-nA silane coupling agent of the group, wherein R is selected from hydrogen, C_1～20Straight or branched chain alkyl, cycloalkyl, aralkenyl and derivatives thereof, and the like, and n may be 0 or 1. The silane coupling agent includes but is not limited to one or more of methyltrimethoxysilane, ethyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-aminopropyltriethoxysilane, gamma-methacryloxypropyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, vinyltrimethoxysilane, 1, 2-bis (triethoxysilyl) ethane, vinyltris (2-methoxyethoxy) silane, gamma-chloropropyltrimethoxysilane, gamma-chloropropyltriethoxysilane, chloromethyltriethoxysilane, gamma-ureidopropyltriethoxysilane, etc.

The auxiliary agent comprises one or more of a bio-based surfactant, halogenated alkane, alcohols, ethers, amines (such as triethylamine), acid, alkali, organic/inorganic micro/nano particles (such as nano silicon dioxide) and the like. The bio-based surfactant has a certain film forming effect, halogenated alkane, alcohols and ethers can play a certain role in enhancing the film forming property, amines, acids and bases are helpful for accelerating the curing, and the organic/inorganic micro-nano particles have a certain role in improving the performance of a coating film. In practical application, whether the auxiliary agent is added or not can be selected according to needs, and the selection and the dosage of the auxiliary agent can be flexibly processed. For example, the mass ratio of the hydroxyl silicone oil to the auxiliary agent is 1:0.001 to 1, preferably 1:0.01 to 1, and more preferably 1:0.02 to 0.2.

In some embodiments of the invention, the catalyst comprises any one or more of an organotin compound, an organotitanium compound, an acid, a base, an organoboron compound, octyl phthalate butyl phthalate, cobalt isooctanoate, cobalt naphthenate, zirconium octanoate, calcium octanoate, zinc octanoate.

The organic tin compound comprises any one or more of dibutyltin dilaurate, di-n-octyltin dilaurate, stannous octoate, stannous isooctanoate, dioctyltin monocaprylate maleate, dibutyltin diisooctoate, 2-ethyl stannous hexanoate and organic tin complexes.

The organic titanium compound includes but is not limited to any one or more of organic titanate (such as diisopropyl bis (ethyl acetoacetate) titanate and isopropyl tris (dioctyl pyrophosphoryl acyloxy) titanate), tetra (trimethylsiloxy) titanium, diisopropoxy-bis (acetylacetonato) titanium, titanium alkoxide and organic titanium chelate.

The acids include, but are not limited to, strong acids (e.g., sulfuric acid), phosphoric acid, boric acid, arylsulfonic acids, C_1～18One or more of organic acid, Lewis acid and the like.

The base includes but is not limited to one or more of strong base (such as KOH, NaOH), organic amine (such as propylamine), quaternary ammonium salt and Lewis base.

The second aspect of the invention is to provide the antifouling paint obtained by the preparation method.

A third aspect of the invention is to provide the use of said anti-fouling coating for surface protection.

The invention also provides an anti-graffiti material which comprises a substrate and an anti-graffiti coating coated on the surface of the substrate, wherein the anti-graffiti coating is formed by coating the anti-fouling paint.

In some embodiments of the present invention, the substrate comprises glass, wood-made board, ceramic board, concrete board or wall, metal board, plastic board, glass fiber board, composite board (metal composite board, wood-plastic composite board, glass fiber reinforced plastic composite board, etc.).

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

(1) the anti-fouling coating has a good anti-doodling effect, can be used for doodling on a coating formed by the coating and completely removing doodling traces by simple erasing, can be repeatedly erased and written, can still use wet rags to erase the doodling when the doodling exceeds more than 10 hours, is particularly suitable for being applied to indoor wall decoration and outer wall decoration to prevent artificial doodling from influencing indoor or outdoor attractiveness, and can also be used for the educational training industry to replace the traditional blackboard and whiteboard;

(2) the anti-fouling coating has better transparency, and the original aesthetic appearance is not damaged when the anti-fouling coating is used on the surface of a substrate;

(3) the anti-fouling paint has strong adhesive force on various base materials, good water resistance and durability;

(4) the antifouling paint has the advantages of relatively low cost of raw materials, no toxicity, no harm, good biocompatibility, safety, health, no stimulation, simple preparation method and easy large-scale mass production.

(5) The anti-fouling coating can be compounded with various organic and inorganic materials, has good expansibility, can adapt to different application requirements, and has wide practical occasions.

Drawings

FIG. 1 is a graph of a coated louver test object of examples 1-4 and comparative examples 3-5;

FIG. 2 is a water resistance test chart of the coatings of examples 1 to 4, wherein a is immediately after immersion in water, and b is after immersion in water for 48 hours;

FIG. 3 is a water contact angle test picture of the coatings of examples 1 to 4 and comparative examples 3 to 5;

FIG. 4 is a graphical representation of ink resistance testing of the coatings of examples 1-4;

FIG. 5 is a graph of ink resistance tests for coatings of comparative examples 3-5;

FIG. 6 is a graph of a writing performance test object of the oil-repellent marker of the coating of examples 1 to 4;

FIG. 7 is a drawing of an oil-repellency marker writing performance test object of the coatings of comparative examples 3 to 5;

FIG. 8 is a drawing of a test object of the writing performance of the special graffiti pen for the coatings of examples 1-4;

FIG. 9 is a drawing of a writing performance test object of the special graffiti pen for the coating of comparative examples 3-5.

Detailed Description

The technical solution of the present invention is further described below with reference to specific examples. The starting materials used in the following examples, unless otherwise specified, are available from conventional commercial sources; the processes used, unless otherwise specified, are conventional in the art.

Example 1

Firstly, adding a proper amount of hydroxyl silicone oil into a flask, and stirring and heating for 1h at the temperature of 100 ℃. After the temperature is reduced to 30 ℃, adding the silane coupling agent methyltrimethoxysiloxane into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent of 1:1, and heating to 70 ℃ for 1 h. Adding triethylamine serving as an auxiliary agent into a flask at the temperature of 70 ℃ according to the mass ratio of the hydroxyl silicone oil to the auxiliary agent of 1:0.05, and stirring for 1 h. Adding a catalyst dibutyltin dilaurate into a flask according to the mass ratio of hydroxyl silicone oil to the catalyst of 1:0.001, and stirring for 1h to obtain the anti-fouling coating. And taking out and coating the substrate on a 7.3X 7.3cm ceramic substrate to obtain the anti-graffiti coating.

Example 2

Firstly, adding a proper amount of hydroxyl silicone oil into a flask, and stirring and heating for 1h at the temperature of 100 ℃. After the temperature is reduced to 30 ℃, adding the silane coupling agent methyltrimethoxysiloxane into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent of 2:1, and heating to 70 ℃ for 1 h. Adding triethylamine serving as an auxiliary agent into a flask according to the mass ratio of the hydroxyl silicone oil to the auxiliary agent of 1:0.1, and stirring for 1 h. Adding a catalyst dibutyltin dilaurate into a flask according to the mass ratio of hydroxyl silicone oil to the catalyst of 1:0.01, and stirring for 1h to obtain the anti-fouling coating. Taking out and coating on the substrate to obtain the anti-doodling coating.

Example 3

Firstly, adding a proper amount of hydroxyl silicone oil into a flask, and stirring and heating for 1h at the temperature of 100 ℃. After the temperature is reduced to 30 ℃, adding the silane coupling agent methyltrimethoxysiloxane into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent of 3:1, and heating to 70 ℃ for 1 h. Adding triethylamine serving as an auxiliary agent into a flask according to the mass ratio of the hydroxyl silicone oil to the auxiliary agent of 1:0.1, and stirring for 1 h. Adding stannous octoate serving as a catalyst into a flask according to the mass ratio of 1:0.05 of hydroxyl silicone oil to the catalyst, and stirring for 1 hour to obtain the antifouling paint. Taking out and coating on the substrate to obtain the anti-doodling coating.

Example 4

Firstly, adding a proper amount of hydroxyl silicone oil into a flask, and stirring and heating for 1h at the temperature of 100 ℃. After the temperature is reduced to 30 ℃, adding the silane coupling agent methyltrimethoxysiloxane into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent of 4:1, and heating to 70 ℃ for 1 h. Adding triethylamine serving as an auxiliary agent into a flask according to the mass ratio of the hydroxyl silicone oil to the auxiliary agent of 1:0.15, and stirring for 1 h. Adding a catalyst stannous octoate into a flask according to the mass ratio of polyhydroxy silicone oil to the catalyst of 1:0.1, and stirring for 1h to obtain the anti-fouling coating. Taking out and coating on the substrate to obtain the anti-doodling coating.

Example 5

Firstly, adding a proper amount of hydroxyl silicone oil into a flask, and stirring and heating for 1.5h at the temperature of 110 ℃. After the temperature is reduced to 30 ℃, adding the silane coupling agent methyltrimethoxysiloxane into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent of 1:1, and heating to 65 ℃ for 1.5 h. Adding an auxiliary agent triethylamine into the flask according to the mass ratio of the polyhydroxy silicone oil to the auxiliary agent of 1:0.05, and stirring for 1 h. Adding a catalyst dibutyltin diisooctoate into a flask according to the mass ratio of hydroxyl silicone oil to the catalyst of 1:0.001, and stirring for 50min to obtain the anti-fouling coating. Taking out and coating on the substrate to obtain the anti-doodling coating.

Example 6

Firstly, adding a proper amount of hydroxyl silicone oil into a flask, and stirring and heating for 2 hours at the temperature of 120 ℃. After the temperature is reduced to 30 ℃, the silane coupling agent vinyl trimethoxy silane is added into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent of 1:1, and the temperature is raised to 60 ℃ and kept for 2 hours. Adding the nano silicon dioxide as the assistant into a flask according to the mass ratio of the hydroxyl silicone oil to the assistant of 1:0.05, and stirring for 1.5 h. Adding a catalyst dibutyltin diisooctoate into a flask according to the mass ratio of polyhydroxy silicone oil to the catalyst of 1:0.001, and stirring for 45min to obtain the anti-fouling coating. Taking out and coating on the substrate to obtain the anti-doodling coating.

Example 7

Firstly, adding a proper amount of hydroxyl silicone oil into a flask, and stirring and heating for 2.5 hours at the temperature of 120 ℃. After the temperature is reduced to 30 ℃, the silane coupling agent vinyl trimethoxy silane is added into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent of 2:1, and the temperature is raised to 55 ℃ and kept for 2.5 h. Adding the nano silicon dioxide as the assistant into a flask according to the mass ratio of the polyhydroxy silicone oil to the assistant of 1:0.1, and stirring for 2 hours. Adding a catalyst dibutyltin dilaurate into a flask according to the mass ratio of hydroxyl silicone oil to the catalyst of 1:0.01, and stirring for 40min to obtain the anti-fouling coating. Taking out and coating the substrate to obtain the anti-doodling coating.

Example 8

Firstly, adding a proper amount of hydroxyl silicone oil into a flask, and stirring and heating for 2.5 hours at the temperature of 130 ℃. After the temperature is reduced to 30 ℃, the silane coupling agent vinyl trimethoxy silane is added into the flask according to the mass ratio of hydroxyl silicone oil to silane coupling agent of 3:1, and the temperature is raised to 55 ℃ and kept for 2 hours. Adding the nano silicon dioxide as the assistant into a flask according to the mass ratio of the hydroxyl silicone oil to the assistant of 1:0.1, and stirring for 2 hours. Adding a catalyst dibutyltin dilaurate into a flask according to the mass ratio of polyhydroxy silicone oil to the catalyst of 1:0.1, and stirring for 20min to obtain the anti-fouling coating. Taking out and coating on the substrate to obtain the anti-doodling coating.

Example 9

Firstly, adding a proper amount of hydroxyl silicone oil into a flask, and stirring and heating for 2 hours at the temperature of 120 ℃. After the temperature is reduced to 30 ℃, the silane coupling agent vinyl trimethoxy silicon is added into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent alkyl being 3:1, and the temperature is raised to 60 ℃ and kept for 2 hours. Adding the nano silicon dioxide as the assistant into a flask according to the mass ratio of the hydroxyl silicone oil to the assistant of 1:0.5, and stirring for 2 hours. Adding an organic amine catalyst n-propylamine into a flask according to the mass ratio of polyhydroxy silicone oil to catalyst of 1:0.1, and stirring for 10min to obtain the antifouling paint. Taking out and coating the substrate to obtain the anti-doodling coating.

Comparative example 1

Firstly, adding a proper amount of hydroxyl silicone oil into a flask, and stirring and heating for 1h at the temperature of 100 ℃. After the temperature is reduced to 30 ℃, adding a silane coupling agent methyl trimethoxy silane into a flask according to the mass ratio of hydroxyl silicone oil to the silane coupling agent of 4:1, and heating to 70 ℃ for 1 hour. Adding triethylamine serving as an auxiliary agent into a flask according to the mass ratio of the hydroxyl silicone oil to the auxiliary agent of 1:0.05, and stirring for 1 h. Adding tetramethyl ammonium hydroxide serving as an alkaline catalyst into a flask according to the mass ratio of polyhydroxy silicone oil to the catalyst of 1:0.2, and stirring for 1h to obtain the anti-fouling coating. Taking out and coating the substrate to obtain the anti-doodling coating.

Comparative example 2

Under the condition of room temperature, firstly adding a proper amount of hydroxyl silicone oil into a flask, and then adding a silane coupling agent methyl trimethoxy siloxane into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent of 5: 1; stirring for 25min, then adding an auxiliary agent triethylamine into the flask according to the mass ratio of the hydroxyl silicone oil to the auxiliary agent of 1:0.05, and stirring for 2 h; and finally, adding a catalyst dibutyltin dilauric silicic acid into a flask according to the mass ratio of the hydroxyl silicone oil to the catalyst of 1:0.01, stirring for 10min, taking out and coating on a substrate.

Comparative example 3

Under the condition of room temperature, firstly adding a proper amount of hydroxyl silicone oil into a flask, then adding a silane coupling agent methyl trimethoxy siloxane into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent of 5:2, then adding an auxiliary agent triethylamine into the flask according to the mass ratio of the hydroxyl silicone oil to the auxiliary agent of 1:0.05, and then stirring for 2 hours; and finally, adding a catalyst dibutyltin dilauric silicic acid into a flask according to the mass ratio of the hydroxyl silicone oil to the catalyst of 1:0.01, stirring for 5min, taking out and coating on a substrate.

Comparative example 4

Adding a proper amount of hydroxyl silicone oil into a flask at 120 ℃ in the whole process, then adding a silane coupling agent methyltrimethoxysiloxane into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent of 5:1, then adding an auxiliary agent triethylamine into the flask according to the mass ratio of the hydroxyl silicone oil to the auxiliary agent of 1:0.1, and then stirring for 2 hours; and finally, adding a catalyst dibutyltin dilauric silicic acid into a flask according to the mass ratio of the hydroxyl silicone oil to the catalyst of 1:0.01, stirring for 5min, taking out and coating on a substrate.

Comparative example 5

Adding a proper amount of hydroxyl silicone oil into a flask at the temperature of 60 ℃ in the whole process, then adding a silane coupling agent methyl trimethoxy siloxane into the flask according to the mass ratio of the hydroxyl silicone oil to the silane coupling agent of 5:1, then adding a triethylamine promoter into the flask according to the mass ratio of the hydroxyl silicone oil to the auxiliary agent of 1:0.1, and then stirring for 2 hours; and finally, adding a catalyst dibutyltin dilauric silicic acid into a flask according to the mass ratio of the hydroxyl silicone oil to the catalyst of 1:0.5, stirring for 5min, taking out and coating on a substrate.

The raw material composition and preparation parameters of the above examples and comparative examples are shown in table 1 below.

TABLE 1 raw Material composition and preparation parameters

Note: the room temperature is ambient temperature and is 20-25 ℃.

The coatings of the above examples and comparative examples were subjected to performance tests, and the results are shown in table 2 below.

TABLE 2 coating Performance test results

Note: the adhesion test standard refers to the Baige test method, and the smaller the number, the higher the adhesion.

The coatings prepared in the embodiments 1 to 4 are soft in texture and have certain elasticity, and according to the test results in the table 1, the coatings prepared in the embodiments 1 to 4 are high in drying speed and strong in adhesive force, reach the 0-grade, and are good in water resistance and scrawling resistance. Comparative example 1 using tetramethylammonium hydroxide as a catalyst, the result was that after the coating was prepared on the substrate, the inside of the coating remained liquid at room temperature for more than 6 hours, and was not of practical value. Comparative example 2 shows that the drying time is too long and the interior is still liquid for more than 6 hours at room temperature, and thus it is not practical.

More specific performance testing procedures are as follows:

(1) adhesion test

The picture of the coating hundred grid test object of the examples 1-4 and the comparative examples 3-5 is shown in figure 1, and it can be seen from the picture that the coatings of the examples 1-4 and the comparative examples 3-5 have good transparency; in the scribing process, the coating of examples 1 to 4 has no peeling of the grid edge after scribing, while the scribing areas of comparative examples 3 to 5 have peeling, and the peeling of comparative example 4 and comparative example 5 is more serious.

(2) Water resistance test

The substrate coated with the anti-graffiti coating is placed in water and soaked at normal temperature, and a real figure immediately after the substrate is placed in water and soaked in water for 48 hours is shown in fig. 2. As can be seen from figure 2, the coatings of examples 1-4 have no peeling or falling phenomenon after being soaked in water for 48 hours, and the coatings are complete.

(3) Water contact Angle test

The pictures of the water contact angle test of the coatings of examples 1-4 and comparative examples 3-5 are shown in fig. 3, and the water contact angle test results show that the water contact angle of the coating is not greatly influenced by fine adjustment of the parameters for preparing the anti-fouling coating.

(4) Anti-graffiti test

The ink was dropped onto the coating surface and after 5 hours, it was then wiped off using a wet towel, and the results are shown in fig. 4 and 5. It can be seen that the ink on the coatings of the embodiments 1 to 4 can be erased cleanly by simple erasing without leaving any trace; the same effect was maintained after 20 repeated rubs. The coatings of comparative examples 3-5 also had similar ink rub-off effects.

Writing on the coating with an oil marker and then wiping off with a wet towel, the results are shown in fig. 6 and 7. It can be seen that the characters written on the coatings of the embodiments 1 to 4 can be erased cleanly by simple erasing; the same effect was maintained after 20 repeated rubs. In contrast, the oily marker writing on the surface of the coating of comparative examples 3-5 left a very obvious mark after being erased with a wet towel, and could not be completely erased.

Instead, a special graffiti pen was used to write on the coating and then wiped off using a wet towel, the results of which are shown in fig. 8 and 9. It can be seen that the erasing effect of each coating on the writing trace of the special graffiti pen is similar to that of an oil-based marking pen, namely, the characters of the writing content on the coatings of the embodiments 1-4 can be erased completely by simple erasing without any trace being left; the same effect can be still kept after 20 times of repeated scrubbing; and the writing contents of the special graffiti pen on the coating surface of the comparative examples 3-5 leave traces after being erased by using a wet towel, and cannot be completely erased, wherein the residual traces of the comparative example 3 are slightly lighter than those of the comparative examples 4 and 5.

By comparing examples 1-4 with comparative example 1, it can be seen that proper selection of the catalyst is one of the key factors in the success of sample preparation. Compared with the comparative examples 2 to 5, the examples 1 to 4 show that the reaction process is very slow and the coating forming state is poor at normal temperature; samples obtained under different heating conditions for different formulations all suffer from different levels of drawbacks, such as: the coating obtained in the comparative example 3 at normal temperature has good stain resistance to ink, but has poor stain resistance to oily marking pens and special doodle pens, and cannot be thoroughly removed; comparative example 4 and comparative example 5 are in a high-temperature state, the reaction process is rapid, the coating is solidified before operation, and the subsequent construction operation is not facilitated, wherein the resistance of the comparative example 4 to a special graffiti pen is poor, the resistance of the comparative example 5 to an oil mark pen is poor, and after the graffiti is performed by using an oil mark pen, an erasing test is performed, so that clear marks are left on the surface of the graffiti.

The test results of the coatings of examples 5 to 9 are the same as those of examples 1 to 4, and are not repeated herein.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A preparation method of an anti-fouling coating is characterized by comprising the following steps: the method comprises the following steps:

heating hydroxyl silicone oil to obtain pretreated hydroxyl silicone oil, wherein the temperature for heating the hydroxyl silicone oil is 70-150 ℃, and the time is 0.5-8 hours;

cooling the pretreated hydroxyl silicone oil to 20-80 ℃, adding a silane coupling agent, reacting for 0.01-10 h, adding an auxiliary agent, and reacting for 0.01-10 h again to obtain a mixed solution;

adding a catalyst into the mixed solution to perform catalytic reaction for 0.01-10 hours to obtain an anti-fouling coating;

the mass ratio of the hydroxyl silicone oil to the silane coupling agent is 0.1-10: 1; the mass ratio of the hydroxyl silicone oil to the auxiliary agent is 1: 0.02-0.2; the mass ratio of the hydroxyl silicone oil to the catalyst is 1: 0.0001-0.1;

the silane coupling agent is OR OR NR with a molecular formula containing three OR more_2-nA silane coupling agent of the group, wherein R is selected from hydrogen and C_1～20Straight or branched chain alkyl, cycloalkyl, aralkenyl and derivatives thereof, n is 0 or 1;

the auxiliary agent comprises one or more of a bio-based surfactant, halogenated alkane, alcohols, ethers, amines, acids, bases and organic/inorganic micro-nano particles;

the catalyst comprises any one or more of organic tin compounds, organic titanium compounds, acids, bases, organic boron compounds, cobalt iso-octoate, cobalt naphthenate, zirconium octoate, calcium octoate and zinc octoate, and the bases comprise one or more of KOH, NaOH, propylamine and Lewis bases.

2. The method of claim 1, wherein: the temperature for heating the hydroxyl silicone oil is 70-130 ℃.

3. The method of claim 1, wherein: and the time for heating the hydroxyl silicone oil is 1-3 h.

4. The method of claim 1, wherein: the viscosity of the hydroxyl silicone oil at 25 ℃ is 500-30000 mPa.S.

5. The method of claim 1, wherein: the mass ratio of the hydroxyl silicone oil to the silane coupling agent is 0.5-10: 1.

6. the method according to claim 5, wherein: the mass ratio of the hydroxyl silicone oil to the silane coupling agent is 1-5: 1.

7. The method of claim 1, wherein: the mass ratio of the hydroxyl silicone oil to the catalyst is 1: 0.001-0.1.

8. An antifouling coating obtained by the preparation method of any one of claims 1 to 7.

9. Use of the antifouling coating according to claim 8 for surface protection.

10. An anti-graffiti material, characterized by: comprises a substrate and an anti-graffiti coating coated on the surface of the substrate, wherein the anti-graffiti coating is formed by coating the anti-fouling coating of claim 8.

11. The anti-graffiti material of claim 10, wherein: the base material comprises glass, wooden plates, ceramic plates, concrete plates or walls, metal plates, plastic plates, glass fiber plates and composite plates.