Single-component high-permeability rust-bearing anticorrosive coating material, preparation method and application thereof

Abstract

The application relates to the technical field of anticorrosive coatings, in particular to a single-component high-permeability rust-bearing anticorrosive coating and a preparation method and application thereof. The single-component high-permeability rust-bearing anticorrosive coating is prepared from the following components in parts by weight: 30-50 parts of polyurethane prepolymer, 30-50 parts of wetting solvent, 10-30 parts of pigment and filler, 10-20 parts of water removal enhancer and 1.75-5 parts of auxiliary agent. The auxiliary agent comprises a dispersant, a thixotropic agent and a defoaming agent. The water removal enhancer is at least one of oxazolidine and aldimine. The curing time of the coating is accelerated, the drying time can be controlled to be less than 5 hours, the film integrity of the coating is improved, and the strength, wear resistance and hardness are improved by selecting and limiting the use amount of the water removal enhancer, selecting the polyol molecular weight of the polyurethane prepolymer and selecting the pigment and filler. The coating is more easily permeated into iron rust under the condition of spreading on the surface of the base material by limiting the type of the wetting solvent, so that the rust-bearing adhesion and anticorrosive performance of the coating are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of anticorrosive paint, and particularly relates to a single-component high-penetration rust-bearing anticorrosive paint as well as a preparation method and application thereof. BACKGROUND

[0002] Corrosion is a common degradation behavior caused by the interaction between metal materials and the surrounding environment, which can reduce the mechanical and chemical properties of metal materials (especially steel structures). In order to slow down the corrosion rate of steel structures and prolong their service life, coating protection is the most economical and effective corrosion protection method at present. However, excellent corrosion resistance requires that the rust products on the steel be removed completely before coating. Because the rust often contains water, Cl - and other strong corrosive media, which can accelerate the progress of the corrosion reaction, and the loose rust will also lead to the decrease of the adhesion between the paint film and the substrate, thus causing the peeling and falling off of the coating. Therefore, rust removal treatment is an important part of the coating process, and plays a decisive role in the success or failure of corrosion protection.

[0003] However, many large steel structure facilities such as buildings, bridges, ships and signal towers are difficult to be mechanically derusted due to the limitation of construction conditions during maintenance, and can only be derusted by hand or electric tools. The tedious process leads to the problems of poor rust removal quality and high rust removal cost in the coating process. Therefore, it is necessary to prepare a coating that can be directly applied on the rusted substrate.

[0004] Rust corrosion protection paint can be directly coated on the surface of the substrate which cannot be removed or not completely removed. The paint can greatly reduce the difficulty of on-site construction work, and can effectively avoid the problems of dust pollution and noise pollution caused by on-site construction rust removal, and reduce the harm to the human body. Among them, the penetration type rust corrosion protection paint can penetrate into the inside of the rust through its excellent penetration performance, and cover and solidify the rust which accelerates corrosion into a corrosion protection factor with barrier function, so as to convert the loose and easily corroded rust surface into a composite protective layer with good adhesion. Compared with other common rust corrosion protection paints such as conversion type rust paint, stable type rust paint, water-based rust paint and the like, the penetration type rust corrosion protection paint is one of the most widely used and best protective effect rust corrosion protection paints in the industry due to its simple preparation principle, reasonable protection mechanism and good protection effect (such as high rust adhesion and good corrosion resistance). Obviously, a large amount of organic solvent in the system makes the construction process of the paint have serious environmental pollution and safety problems. In addition, a large amount of solvent also prolongs the drying time of the coating, prolongs the construction period, and cannot meet the needs of some urgent construction periods. Especially for conventional single-component polyurethane rust paint, the moisture curing mechanism will further prolong the drying time of the coating (more than 10 hours), and the moisture curing process will also produce carbon dioxide, which will also cause defects in the coating and reduce the corrosion resistance of the coating. SUMMARY

[0005] The main purpose of the present application is to provide a single-component high-penetration rust corrosion protection paint and its preparation method and application, aiming at improving the technical problems of the existing penetration type rust corrosion protection paint such as insufficient penetration, slow curing speed and many coating defects.

[0006] To achieve the above purpose, the present application provides a single-component high-penetration rust corrosion protection paint, which is prepared from the following components in parts by weight: polyurethane prepolymer 30-50 parts, wetting solvent 30-50 parts, pigment and filler 10-30 parts, water removal enhancer 10-20 parts, and auxiliary agent 1.75-5 parts.

[0007] The auxiliary agent includes dispersant, thixotropic agent and defoaming agent, and the water removal enhancer is at least one of oxazolidine and aldimine.

[0008] The ordinary paint generally needs to reduce the surface tension of the system, so that it is easy to spread on the surface of the substrate; however, low surface tension is not conducive to the penetration of the material in the porous medium such as rust. Therefore, the present application introduces a special wetting solvent, so that the paint can spread on the surface of the metal substrate, and also better wet and penetrate into the capillary pores of the rust, thereby enhancing the paint and improving the rust adhesion and corrosion resistance of the coating; in addition, the present application also introduces oxazolidine and aldimine type water removal enhancer to react with moisture in the atmosphere to generate amine (crosslinking agent), and the amine reacts with the NCO group in the polyurethane prepolymer to obtain one-component polyurea resin (crosslinking and curing). The addition of the water removal enhancer not only solves the problem of carbon dioxide overflow to form defects in the moisture curing process of the one-component polyurethane rust paint, but also further improves the crosslinking density and film integrity of the coating, so that the mechanical properties and solvent resistance of the coating are improved. In addition, the coating also has the characteristics of high hardness and good wear resistance, and has strong barrier ability and corrosion resistance to corrosive media.

[0009] In addition, the introduction of the water removal enhancer also shortens the curing time of the paint, so that the coating can be dried within 5 hours, which is much faster than the traditional one-component polyurethane rust paint. In particular, the amount of the water removal enhancer in the present application needs to be limited to more than 10 parts by weight. When the amount of the water removal enhancer is less than 10 parts by weight, the water removal enhancer mainly plays a conventional water removal role, and the degree of participation in the above reaction is not strong, so that a better polyurethane urea and polyurea crosslinking network cannot be formed, and the curing (drying) time of the paint will be prolonged to 10-24h.

[0010] The wetting solvent can be at least one of vegetable oil, aromatic solvent oil, alkane solvent oil, tributyl citrate, petroleum hydrogenated light fraction, petroleum ether and mineral oil, and the pigment filler can be at least one of mica, iron oxide, aluminum powder, zinc powder, aluminum oxide, zinc oxide, graphene, aluminum silver paste, talc powder, calcium carbonate and barium sulfate.

[0011] Preferably, the weight parts of each raw material are as follows: polyurethane prepolymer 30-50 parts, wetting solvent 30-40 parts, pigment filler 10-20 parts, water removal enhancer 10-20 parts, and auxiliary agent 1.75-4.75 parts; in the auxiliary agent, the dispersant is 0.25-2 parts by weight, the thixotropic agent is 0.75-1.5 parts by weight, and the defoaming agent is 0.5-3 parts by weight.

[0012] Preferably, the polyurethane prepolymer is obtained by reacting isocyanate monomers and polyols, wherein the isocyanate accounts for 30-90wt% of the polyurethane prepolymer;

[0013] The isocyanate monomer is at least one of polymethylene polyphenyl polyisocyanate, diphenylmethane-4, 4'-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, cyclohexane dimethylene diisocyanate, 4, 4'-dicyclohexyl methane diisocyanate, tetramethyl xylylene diisocyanate and toluene diisocyanate;

[0014] The polyol is at least one of polyoxypropylene ether polyol, polytetrahydrofuran polyol, polyether polyol and polyolefin polyol.

[0015] The polyurethane prepolymer is prepared from isocyanate monomer and polyol, and the preparation process is simple. By controlling different isocyanates and polyols, polyurethane prepolymers with different functions such as different polymerization degree, branching degree, hardness, reactivity and locking degree can be obtained. When the generated polyurethane prepolymer reacts with the remaining raw materials, the film integrity of the coating can be further improved.

[0016] Preferably, the molecular weight of the polyol is 800-2000. Controlling the molecular weight of the polyol for preparing the polyurethane prepolymer in the above range can further shorten the curing time of the coating, and at the same time, the coating also has long-term storage stability, and the storage time of the finished coating after sealing can be up to 1 year or more. In addition, the polyurethane prepolymer prepared by using the polyol with the above molecular weight range also has high hardness after subsequent reaction.

[0017] Preferably, the wetting solvent is at least one of vegetable oil or tributyl citrate; the vegetable oil is at least one of castor oil, raw tung oil, cooked tung oil, soybean oil, peanut oil, orange oil, rapeseed oil and epoxy soybean oil.

[0018] The objective reason for choosing the above solvent is that they are all bio-based solvents, which is an important way to realize energy saving and emission reduction, low carbon and environmental protection in the repair process. Moreover, compared with traditional organic solvents, the solvents involved in the present application have lower toxicity, no negative impact on the atmosphere and environment water during the coating process, and can also reduce the risk of workers exposed to harmful chemicals.

[0019] The subjective reason is that tributyl citrate and vegetable oil have excellent wetting property and suitable surface tension (35-50 N / m), which can make the coating spread on the surface of the metal substrate, and also make it better infiltrate into the capillary pores of rust, enhance the coating effect of rust, and improve the adhesion and corrosion resistance of the coating. In addition, due to the special structure of tributyl citrate and vegetable oil, they can form hydrogen bonds with the coating (urea-based) to avoid solvent evaporation, and also integrate the solvent and resin, thereby improving the compactness of the coating, reducing the defects caused by solvent evaporation, and enhancing the corrosion resistance of the coating. Finally, tributyl citrate and vegetable oil have excellent water resistance, which can effectively prevent the metal from contacting with external oxygen, moisture and other substances, and reduce the risk of rust.

[0020] Preferably, the color filler is a combination of flaky color filler and spherical color filler, and the mass ratio of the flaky color filler to the spherical color filler is 1:1-2; the flaky color filler is micron-sized, and the spherical color filler is nano-sized, so that the micro-nano structure color filler formed can make the rusted coating have better performance.

[0021] The flaky color filler includes at least one of talc, calcium carbonate and barium sulfate, and the spherical color filler includes at least one of aluminum powder and zinc powder.

[0022] The color filler in the scheme can also be a combination of flaky color filler and spherical color filler, such as a combination of flaky inert fillers such as talc, calcium carbonate and barium sulfate with spherical active fillers such as zinc powder to realize complementary structure, and the composite structure is formed between the spherical and layered fillers, the spherical fillers are filled into the gaps of the flaky material accumulation, forming a more compact structure, improving the mechanical properties and ion penetration resistance of the coating, and having stronger corrosion resistance. At the same time, the film integrity can also be further improved.

[0023] More preferably, the polyurethane prepolymer is 30-40 parts by weight, the wetting solvent is 30-40 parts by weight, the color filler is 10-20 parts by weight, the water removal enhancer is 10-18 parts by weight, and the auxiliary agent is 2-4.75 parts by weight.

[0024] In the auxiliary agent, the dispersant is 0.5-1 parts by weight, the thixotropic agent is 0.75-1 parts by weight, and the defoaming agent is 0.5-3 parts by weight. When the content of the raw materials is controlled in the above range, the comprehensive performance of the obtained coating is better.

[0025] Preferably, the water removal enhancer is at least one of Incozol 2, Incozol 4, Incozol EH, Incozol LV, Aldirez BH and Aldirez A.

[0026] The dispersant is at least one of BYK-108, BYK-110, BYK-116, BYK-163, BYK-180, BYK-190 and BYK-9076;

[0027] The thixotropic agent is at least one of polyamide wax, organic bentonite, asbestos and fumed silica;

[0028] The defoaming agent is at least one of BYK-088, BYK-141, BYK-057, BYK-065, BYK-A530, BYK-A555 and BYK-1790.

[0029] In addition, the application also provides a preparation method of the single-component high-permeability rust-bearing anticorrosive coating.

[0030] (1) reacting isocyanate monomers and polyols at 70-80°C for 1-2 hours under inert gas protection to obtain a polyurethane prepolymer;

[0031] (2) mixing the polyurethane prepolymer, wetting solvent and water-removing enhancer uniformly at room temperature under sealed conditions;

[0032] (3) adding the pigments and fillers and the additives into the mixed raw materials of step (2) under sealed conditions, mixing uniformly to obtain the single-component high-permeability rust-bearing anticorrosive coating.

[0033] In the prior art, a small amount of oxazolidine and aldimine and the like water-removing agents are mixed with pigments and fillers to remove trace amounts of water in the system, so that the water-removing agents do not react with the polyurethane prepolymer when mixed, thereby improving the stability of the coating. In this process, the pigments and fillers are first mixed with the water-removing agents to remove water, and then the resin is mixed with the pigments and fillers after water removal to prepare the coating.

[0034] However, the purpose of using oxazolidine and aldimine compounds in the present application is not only to improve the storage stability of the coating, but also to accelerate the curing speed of the coating, reduce coating defects, and enhance the wear resistance and chemical corrosion resistance of the coating. Compared with the prior art, in addition to regulating the structure and amount of the water-removing enhancer, the preparation process of the coating is also limited, that is, the resin is first mixed with the water-removing enhancer, and then the pigments and fillers are added. In this preparation process, the resin and the water-removing enhancer can both react with the trace amounts of water in the pigments and fillers. Under the competition of the two, the amount of the polyurethane prepolymer in the system is appropriately reduced, but the water-removing enhancer can be stably retained in the coating system. When coating, the water-removing enhancer is preferentially decomposed into primary amines / alcohol amines under the action of moisture, which can rapidly crosslink with the polyurethane prepolymer to form polyurea, thereby triggering a significant increase in the curing speed of the coating, and avoiding the generation of carbon dioxide from the polyurethane prepolymer under the action of moisture to prevent the formation of coating defects.

[0035] The application also provides application of the single-component high-permeability rust-bearing anticorrosive paint in the anticorrosive field, and the single-component high-permeability rust-bearing anticorrosive paint has a dry time of less than or equal to 5 hours. After the paint is applied to a rusted substrate, the dry time can be controlled to be less than or equal to 5 hours.

[0036] Compared with the prior art, the single-component high-permeability rust-bearing anticorrosive paint has the following beneficial effects:

[0037] 1. The oxazolidine and aldimine type water removal enhancer is introduced, and the amount of the water removal enhancer is limited to 10-20 parts, so that the water removal enhancer is preferentially decomposed into primary amines / alcohol amines under the action of moisture in the air, which are rapidly crosslinked with the polyurethane prepolymer to form polyurea, thereby triggering a substantial increase in the curing speed of the paint, especially the dry time, which can be accelerated to less than or equal to 5 hours, much faster than traditional rust-bearing paints. At the same time, the polyurethane prepolymer also directly reacts with moisture to form a competitive system, avoiding the generation of carbon dioxide by direct exposure to the atmosphere, forming coating defects, improving the crosslinking density and film integrity of the coating, and making the coating have better mechanical properties and solvent resistance, high hardness, good wear resistance, strong barrier ability to corrosion ions, and strong corrosion resistance.

[0038] 2. The polyol used to prepare the polyurethane prepolymer has a molecular weight of 800-2000, which can further shorten the curing (dry) time of the paint.

[0039] 3. The sheet-shaped pigment and filler and the spherical pigment and filler are compounded to realize structural complementation, the spherical filler is filled into the gaps between the sheet-shaped materials to form a more compact structure, improve the mechanical properties of the coating and the ion permeation resistance of the coating, and further improve the film integrity. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other related drawings can be obtained by those skilled in the art without creative labor.

[0041] Figure 1 The coating reaction mechanism diagram after the addition of the water removal enhancer in the preparation of the single-component high-permeability rust-bearing anticorrosive paint of the present application, wherein A is a polyurethane prepolymer, and B is a water removal enhancer;

[0042] Figure 2 The film integrity electron microscope photo of the single-component high-permeability rust-bearing anticorrosive paint (with the addition of the water removal enhancer) of the present application;

[0043] Figure 3 EIS test chart of the coating obtained by compounding the flaky pigment and the spherical pigment of the embodiment 8-2 of the present application.

[0044] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work are within the protection scope of the present application.

[0046] In addition, the technical solutions of the embodiments can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize the combination. When the combination of the technical solutions appears to be contradictory or unachievable, it should be considered that the combination of the technical solutions does not exist and is not within the protection scope of the present application.

[0047] A preparation method of a single-component high-permeability rust-bearing anticorrosive coating, comprising the following steps:

[0048] (1) reacting isocyanate monomers and polyols at 70-80℃ for 1-2 hours under inert gas protection to obtain a polyurethane prepolymer, wherein the isocyanate accounts for 30-90wt% of the polyurethane prepolymer;

[0049] The isocyanate monomers are at least one of polymethylene polyphenyl polyisocyanate, diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, cyclohexane dimethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, tetramethyl xylylene diisocyanate and toluene diisocyanate;

[0050] The polyols are at least one of polyoxypropylene ether polyol, polytetrahydrofuran polyol, polyether polyol and polyolefin polyol, and the molecular weight of the polyols is 800-2000;

[0051] (2) mixing 30-50 parts of the polyurethane prepolymer, 30-50 parts of a wetting solvent and 10-20 parts of a water removal enhancer uniformly at room temperature under a sealed condition;

[0052] The wetting solvent is at least one of vegetable oil or tributyl citrate; the vegetable oil is at least one of castor oil, raw tung oil, cooked tung oil, soybean oil, peanut oil, orange oil, rapeseed oil and epoxy soybean oil; the water removal enhancer is at least one of oxazolidine and aldimine; specifically, at least one of Incozol 2, Incozol 4, Incozol EH, Incozol LV, Aldirez BH and Aldirez A;

[0053] (3) Under sealed conditions, 10-30 parts of the color filler and 1.75-5 parts of the auxiliary agent are added into the mixed raw materials in step (2) to be uniformly mixed to obtain the single-component high-permeability rust-bearing anticorrosive coating.

[0054] The color filler is a combination of flaky color filler and spherical color filler, and the mass ratio of the flaky color filler to the spherical color filler is 1:1-2; the flaky color filler includes at least one of talcum powder, calcium carbonate and barium sulfate, and the spherical color filler includes at least one of aluminum powder and zinc powder.

[0055] It can be seen from the electron microscope pictures that the flaky and spherical structure complementary color filler has a more compact morphology structure, which reduces the porosity of the coating. Figure 3 It can be seen from the EIS test pictures in the table that the flaky and spherical structure complementary color filler improves the ion permeability of the coating and improves the corrosion resistance.

[0056] The auxiliary agent includes a dispersing agent, a thixotropic agent and a defoaming agent, the dispersing agent is at least one of BYK-108, BYK-110, BYK-116, BYK-163, BYK-180, BYK-190 and BYK-9076, the thixotropic agent is at least one of polyamide wax, organic bentonite, asbestos and fumed silica, and the defoaming agent is at least one of BYK-088, BYK-141, BYK-057, BYK-065, BYK-A530, BYK-A555 and BYK-1790.

[0057] The technical solutions of the present application are further described in detail in combination with specific embodiments, and it should be understood that the following embodiments are only used to explain the present application and are not used to limit the present application. (The following embodiments are carried out under sealed conditions in each step)

[0058] Embodiment 1

[0059] (1) 20 parts by weight of polymethylene polyphenyl polyisocyanate, 10 parts by weight of polyoxypropylene ether polyol (weight average molecular weight is 2000) are reacted at 80 DEG C for 1.5 hours under inert gas protection to obtain a polyurethane prepolymer;

[0060] (2) To the polyurethane prepolymer, 30 parts by weight of mineral oil and 15 parts by weight of Incozol 2 were added, and mixed and stirred uniformly at normal temperature using a high-speed disperser (wherein the rotation speed of the high-speed disperser was 150, and the following examples were consistent);

[0061] (3) To the raw materials in step (2), 10 parts by weight of mica iron oxide, 1 part by weight of fumed silica, 0.5 part by weight of BYK-108 and 0.25 part by weight of BYK-088 were added, and mixed and stirred uniformly at normal temperature using a high-speed disperser (wherein the rotation speed of the high-speed disperser was 150), to obtain a single-component high-penetration rust-bearing anticorrosive coating.

[0062] Example 2

[0063] (1) 20 parts by weight of polymethylene polyphenyl polyisocyanate, 20 parts by weight of diphenylmethane-4,4'-diisocyanate and 10 parts by weight of polyoxypropylene ether polyol (weight average molecular weight 1000) were reacted under inert gas protection at 75°C for 1.5 hours to obtain a polyurethane prepolymer;

[0064] (2) To the polyurethane prepolymer, 30 parts by weight of mineral oil, 20 parts by weight of petroleum ether and 20 parts by weight of Incozol 2 were added, and mixed and stirred uniformly at normal temperature using a high-speed disperser;

[0065] (3) To the raw materials in step (2), 10 parts by weight of mica iron oxide, 20 parts by weight of aluminum powder, 4 parts by weight of fumed silica, 0.5 part by weight of BYK-108 and 0.5 part by weight of BYK-088 were added, and mixed and stirred uniformly at normal temperature using a high-speed disperser, to obtain a single-component high-penetration rust-bearing anticorrosive coating.

[0066] Example 3

[0067] (1) 10 parts by weight of polymethylene polyphenyl polyisocyanate, 10 parts by weight of diphenylmethane-4,4'-diisocyanate and 10 parts by weight of polyoxypropylene ether polyol (weight average molecular weight 1500) were reacted under inert gas protection at 70°C for 2 hours to obtain a polyurethane prepolymer;

[0068] (2) To the polyurethane prepolymer, 10 parts by weight of mineral oil, 20 parts by weight of petroleum ether, 10 parts by weight of Incozol 2 and 10 parts by weight of Aldirez A were added, and mixed and stirred uniformly at normal temperature using a high-speed disperser;

[0069] (3) To the raw materials in step (2), 10 parts by weight of aluminum powder, 4 parts by weight of fumed silica, 0.5 part by weight of BYK-108 and 0.5 part by weight of BYK-088 were added, and mixed and stirred uniformly at normal temperature using a high-speed disperser, to obtain a single-component high-penetration rust-bearing anticorrosive coating.

[0070] Example 4

[0071] (1) 20 parts by weight of polymethylene polyphenyl polyisocyanate, 10 parts by weight of isophorone diisocyanate, 20 parts by weight of polyoxypropylene ether polyol (weight average molecular weight of 2000) were reacted under inert gas protection at 80°C for 1 hour to obtain a polyurethane prepolymer;

[0072] (2) 30 parts by weight of mineral oil, 13 parts by weight of Incozol EH were added to the polyurethane prepolymer, and mixed and stirred uniformly at room temperature using a high-speed disperser;

[0073] (3) 10 parts by weight of aluminum paste, 0.75 parts by weight of fumed silica, 2 parts by weight of BYK-108, 2 parts by weight of BYK-088 were further added to the raw materials in step (2), and mixed and stirred uniformly at room temperature using a high-speed disperser to obtain a single-component high-penetration rust-bearing anticorrosive coating.

[0074] Example 5

[0075] (1) 10 parts by weight of cyclohexane dimethylene diisocyanate, 10 parts by weight of isophorone diisocyanate, 10 parts by weight of polyolefin polyol (weight average molecular weight of 1000) were reacted under inert gas protection at 75°C for 1.5 hours to obtain a polyurethane prepolymer;

[0076] (2) 20 parts by weight of mineral oil, 20 parts by weight of non-cycloalkane solvent oil (80# solvent oil), 15 parts by weight of Incozol EH, 5 parts by weight of Aldirez A were added to the polyurethane prepolymer, and mixed and stirred uniformly at room temperature using a high-speed disperser;

[0077] (3) 10 parts by weight of aluminum paste, 10 parts by weight of aluminum powder, 1.5 parts by weight of fumed silica, 0.25 parts by weight of BYK-108, 0.5 parts by weight of BYK-088 were further added to the raw materials in step (2), and mixed and stirred uniformly at room temperature using a high-speed disperser to obtain a single-component high-penetration rust-bearing anticorrosive coating.

[0078] Comparative Example 1

[0079] The parameters and preparation steps of this comparative example are consistent with Example 2, and the only difference is that other conventional water removal agents except oxazolidine and aldimine are used, as shown in the following table:

[0080] Type of water removing agent Comparative Example 1-1 Toluene sulfonyl isocyanate Comparative Example 1-2 Calcium oxide Comparative Example 1-3 Triethyl orthoformate

[0081] Comparative Example 2

[0082] The parameters and preparation steps of this comparative example are consistent with Example 2, and the only difference is that the amount of water removal enhancer is adjusted, and the specific adjustment is as shown in the following table:

[0083] Amount of water removal enhancer Comparative Example 2-1 1 part Comparative Example 2-2 3 parts Comparative Example 2-3 5 parts Comparative Example 2-4 7 parts Comparative Example 2-5 9 parts Comparative Example 2-6 12 parts Comparative Example 2-7 15 parts Comparative Example 2-8 18 parts

[0084] Note: the amount of other raw materials not mentioned in the above table remains unchanged.

[0085] Comparative Example 3

[0086] The parameters and preparation steps of the present comparative example are consistent with Example 2, the only difference is that the order of adding raw materials is different, the water enhancer-Incozol 2 is mixed with other raw materials such as pigments and fillers, and after completely removing water, the polyurethane prepolymer is added.

[0087] The rust-bearing anticorrosive coating prepared by Examples 1-5 and Comparative Examples 1-3 is coated on 70*150cm steel plate and tinplate, and various performance tests are carried out, and the specific test results are shown in the following table:

[0088]

[0089] Note: (1) the viscosity of the coating is tested by using NDJ-5S rotary viscometer, 25℃; (2) the coating dry time test method refers to GB / T 1728-1979; (3) the coating flexibility test method refers to GB / T 1731-1993; (4) the coating hardness test method refers to GB / T 6739-2006; (5) the coating abrasion test method refers to GB / T 5478-2008, CS-17, load 1000g, 1000rad, 60r / min; (6) the coating adhesion test method refers to GB / T 5210-2006; (7) the coating contact angle test method refers to GB / T 30447-2013; (8) the coating salt spray resistance test method refers to GB / T 1765-1979; (9) the coating storage stability test method refers to GB 6753.3-86.

[0090] From the test results of Examples 1-3, it can be seen that the coating of the present application can be directly brushed on the rusty or corroded steel substrate, realizing excellent anticorrosion protection effect, the rust-bearing anticorrosive coating has the characteristics of high adhesion and strong surface tolerance, the flexibility test data is 2mm; at the same time, the rust-bearing anticorrosive coating also has excellent salt spray resistance, the storage stability of the material is greatly improved, the curing speed is increased, and the dry time can be controlled within 5h.

[0091] From the test results of Examples 4-5, it can be seen that when the amounts of the raw materials are limited in the preferred ranges (polyurethane prepolymer 30-50 parts, wetting solvent 30-40 parts, pigment and filler 10-20 parts, water removal enhancer 10-20 parts, and auxiliary agent 1.75-4.75 parts; in the auxiliary agent, dispersant 0.25-2 parts by weight, thixotropic agent 0.75-1.5 parts by weight, and defoaming agent 0.5-3 parts by weight), the rust-proof paint prepared has better performance, especially the hardness, wear resistance, and rust adhesion of the paint are all improved.

[0092] From the test results of Example 1 and Comparative Example 1, it can be seen that when other types of water removal agents are used, the hardness of the coating is decreased, the adhesion is weakened, the wear value is increased, and the corrosion resistance is decreased. From the test results of Example 1 and Comparative Example 2, it can be seen that when the amount of the water removal agent is less than 10 parts by weight, the tack-free time of the paint is extended to 10 h, the curing time is greatly increased, the hardness of the coating is somewhat decreased, the adhesion is somewhat weakened, the wear value is somewhat increased, and the corrosion resistance is not much different. From the test results of Example 1 and Comparative Example 3, it can be seen that when the water removal agent is mixed with the pigment and filler to remove water first, and then the polyurethane prepolymer is added, the viscosity of the coating is large, and the storage stability is poor.

[0093] Example 6

[0094] In this example, the parameters and preparation steps are the same as in Example 5, except that the weight average molecular weight of the polyol in step (1) is different, as shown in the following table:

[0095] Weight average molecular weight of polyol Example 5 1000 Example 6-1 800 Example 6-2 2000 Example 6-3 3000 Example 6-4 4000 Example 6-5 5000 Example 6-6 8000

[0096] The rust-proof paint prepared in Example 6 is applied to 70*150 cm steel plates and tin plates, and then various performance tests are conducted, and the specific test results are shown in the following table:

[0097]

[0098] From the test results of Example 6, it can be seen that when the molecular weight of the polyol gradually increases, the viscosity of the paint increases, the tack-free time is also extended, the overall mechanical properties of the coating are decreased, the coating becomes soft, the corrosion resistance is decreased, and the storage stability is decreased.

[0099] Example 7

[0100] In this example, the parameters and preparation steps are the same as in Example 5, except that the type of the wetting solvent is different, as shown in the following table:

[0101] Type of wetting solvent Example 5 20 parts by weight of mineral oil, 20 parts by weight of non-cycloparaffin solvent oil Example 7-1 40 parts by weight of vegetable oil - tung oil Example 7-2 40 parts by weight of tributyl citrate Example 7-3 40 parts by weight of butanone

[0102] The rusted anticorrosive coating prepared in Example 7 was coated on 70*150 cm steel plate and tinplate, and various performance tests were conducted, and the specific test results are shown in the following table:

[0103]

[0104]

[0105] From the test results of Example 7, it can be seen that when the type of wetting solvent is different, when tung oil is selected as the wetting solvent, the tung oil can undergo oxidation reaction with oxygen in the air to shorten the drying time of the coating, and at the same time, the coating has more excellent mechanical properties and corrosion resistance; when tributyl citrate is selected as the wetting solvent, the coating can spread on the surface of the metal substrate, and at the same time, it can better infiltrate into the capillary pores of the rust, enhance the coating effect of the coating on the rust, and improve the adhesion and corrosion resistance of the coating. When traditional wetting solvents such as butanone are used, although they have the physical property of easy volatilization, but after the solvent volatilizes, there will be a large number of pores on the surface of the coating, resulting in uneven coating, so the adhesion of the coating will be significantly reduced, and the corrosion resistance of the coating will be reduced.

[0106] Example 8

[0107] The parameters and preparation steps of this example are consistent with Example 5, and the only difference is that the types of pigments and fillers are different, as shown in the following table:

[0108] Type of pigment and filler Example 5 10 parts by weight of aluminum paste, 10 parts by weight of aluminum powder Example 8-1 10 parts by weight of flaky calcium carbonate, 10 parts by weight of spherical zinc powder Example 8-2 6 parts by weight of flaky barium sulfate, 14 parts by weight of spherical aluminum powder Example 8-3 10 parts by weight of graphene, 10 parts by weight of zinc powder

[0109] The rusted anticorrosive coating prepared in Example 8 was coated on 70*150 cm steel plate and tinplate, and various performance tests were conducted, and the specific test results are shown in the following table:

[0110]

[0111] From the test results of Example 8, it can be seen that when the pigments and fillers are compounded by flaky pigments and spherical pigments, the coating obtained has better coating film integrity, so the hardness in the test data is higher, the abrasion value is lower, and the corrosion resistance is improved.

[0112] From the test results of Example 8-4, it can be seen that the pigments and fillers can also be compounded by graphene and sacrificial pigments (aluminum powder or zinc powder). The metal pigments such as aluminum powder and zinc powder preferentially undergo oxidation reaction to form a dense aluminum oxide and zinc oxide protective film, and after compounding with graphene with special structure, the salt fog resistance of the coating can be significantly enhanced.

[0113] Example 9

[0114] (1) 10 parts by weight of isophorone diisocyanate, 10 parts by weight of xylylene diisocyanate, 20 parts by weight of polyether polyol (weight average molecular weight 1000) were reacted at 75°C for 1.5 hours under inert gas protection to obtain a polyurethane prepolymer;

[0115] (2) 15 parts by weight of raw tung oil, 15 parts by weight of cooked tung oil, 15 parts by weight of Aldirez A were added to the polyurethane prepolymer, and mixed and stirred uniformly at room temperature using a high-speed disperser;

[0116] (3) 10 parts by weight of flaky talc, 10 parts by weight of spherical zinc powder, 1 part by weight of fumed silica, 0.85 parts by weight of BYK-108, 0.75 parts by weight of BYK-088 were further added to the raw materials in step (2), and mixed and stirred uniformly at room temperature using a high-speed disperser to obtain a single-component high-penetration rust-bearing anticorrosive coating.

[0117] Example 10

[0118] (1) 10 parts by weight of cyclohexane dimethylene diisocyanate, 10 parts by weight of 4,4'-dicyclohexylmethane diisocyanate, 10 parts by weight of polyolefin polyol (weight average molecular weight 1000) were reacted at 75°C for 1.5 hours under inert gas protection to obtain a polyurethane prepolymer;

[0119] (2) 12 parts by weight of tributyl citrate, 20 parts by weight of epoxy soybean oil, 18 parts by weight of Incozol LV were added to the polyurethane prepolymer, and mixed and stirred uniformly at room temperature using a high-speed disperser;

[0120] (3) 6 parts by weight of flaky barium sulfate, 14 parts by weight of spherical aluminum powder, 1 part by weight of fumed silica, 1 part by weight of BYK-163, 0.5 parts by weight of BYK-065 were further added to the raw materials in step (2), and mixed and stirred uniformly at room temperature using a high-speed disperser to obtain a single-component high-penetration rust-bearing anticorrosive coating.

[0121] The rust-bearing anticorrosive coating prepared in Examples 9-10 was coated on 70*150 cm steel plates and tinplate, and various performance tests were conducted, and the specific test results are shown in the following table:

[0122]

[0123] As can be seen from the test results of Examples 9-10, when the amount of each raw material is limited to the optimal range (30-40 parts of polyurethane prepolymer, 30-40 parts of wetting solvent, 10-20 parts of pigments and fillers, 10-18 parts of dehydration reinforcing agent, and 2-4.75 parts of additives; among the additives, 0.5-1 parts by weight of dispersant, 0.75-1 parts by weight of thixotropic agent, and 0.5-3 parts by weight of defoamer), and the molecular weight of polyol, the type of wetting solvent, and the type of pigments and fillers are simultaneously limited, the obtained coating has a shorter drying time, higher hardness after curing, greater adhesion, lower abrasion value, and better anti-corrosion performance.

[0124] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A single-component, high-penetration, rust-resistant anti-corrosion coating, characterized in that, The single-component high-penetration rust-resistant anti-corrosion coating is prepared using the following steps: (1) 10 parts by weight of cyclohexanedimethyl diisocyanate, 10 parts by weight of isophorone diisocyanate and 10 parts by weight of polyolefin polyol with a weight average molecular weight of 1000 were reacted at 75°C for 1.5 hours under inert gas protection to obtain polyurethane prepolymer. (2) Add 20 parts by weight of mineral oil, 20 parts by weight of No. 80 solvent oil, 15 parts by weight of Incozol EH and 5 parts by weight of Aldirez A to the polyurethane prepolymer and mix them evenly using a high-speed disperser at room temperature. (3) Add 10 parts by weight of graphene, 10 parts by weight of zinc powder, 1.5 parts by weight of fumed silica, 0.25 parts by weight of BYK-108 and 0.5 parts by weight of BYK-088 to the raw materials in step (2), and mix them evenly using a high-speed disperser at room temperature to obtain the single-component high-penetration rust-resistant anti-corrosion coating.

2. The application of a single-component high-penetration rust-resistant anti-corrosion coating as described in claim 1 in the field of corrosion protection, characterized in that, The drying time of the single-component high-penetration rust-resistant anti-corrosion coating is ≤5h.

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