A solvent-free marine environment self-repairing anti-corrosion coating and preparation method thereof

Abstract

The invention discloses a solvent-free marine environment self-repairing anticorrosive coating and a preparation method thereof, which belongs to the field of anticorrosive coatings, including component A and component B, wherein the mass ratio of component A to component B is 100:29-35; the component A includes the following components in parts by weight: 50-55 parts of epoxy-modified isocyanate oligomers, 30-35 parts of rutile titanium dioxide, 2-4 parts of fumed silica, 1.5-2 parts of thermally conductive dispersants, 2 parts of self-repairing compounds, 0.5-1 parts of silicone defoamers, and 1 part of carbon black powder; wherein the self-repairing compound is a compound prepared by Diels-Alder reaction; and the component B is cashew nut shell oil polyol. The present invention adds a compound prepared by DA reaction to epoxy-modified isocyanate oligomers, and uses DA reversible reaction to construct a self-repairing network, so that the coating formed by the coating can be self-repaired by heating after being scratched or impacted.

Description

Technical Field

[0001] The invention belongs to the field of anti-corrosion coatings and relates to a solvent-free marine environment self-repairing anti-corrosion coating and a preparation method thereof. Background Art

[0002] In the marine environment, due to its high salinity and high humidity, offshore facilities often face serious corrosion problems. The labor cost of repairing coatings in the marine environment is high. In order to meet the requirements of long-term corrosion protection in the marine environment and take into account the development trend of environmentally friendly coatings, solvent-free self-healing anti-corrosion coatings are the key research and development direction.

[0003] Existing self-healing coatings usually adopt the technical solution of microcapsules + self-healing agents, such as patent CN117417680A, a self-healing coating and its preparation method and application; the microcapsule design is filled with materials such as benzotriazole (BTA) as corrosion inhibitors in the capsule. When the coating is damaged, the capsule ruptures and releases the corrosion inhibitor, which reacts chemically with the damaged area to repair it, so as to achieve the purpose of delaying the spread of corrosion; however, the corrosion inhibitor cannot be replenished, so this technical solution can only achieve a limited number of self-repairs within a certain period of time, and the repair durability is short. At the same time, most of the current self-healing coatings are solvent-based coatings. Although solvent-based coatings have excellent performance, they do not meet the requirements of marine environmental protection, and water-based coatings cannot meet the performance requirements of heavy-duty corrosion protection in the marine environment. Therefore, there is currently a lack of an environmentally friendly and long-lasting self-healing coating to meet the use needs of marine scenes. Summary of the invention

[0004] The purpose of the present invention is to provide a solvent-free marine environment self-healing anti-corrosion coating and a preparation method thereof, which solves the current problem of lack of an environmentally friendly and long-lasting self-healing coating to meet the use requirements of marine scenes.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A solvent-free marine environment self-repairing anti-corrosion coating, comprising component A and component B, wherein the mass ratio of component A to component B is 100:29-35;

[0007] The component A comprises the following components in parts by weight: 50-55 parts of epoxy-modified isocyanate oligomer, 30-35 parts of rutile titanium dioxide, 2-4 parts of fumed silica, 1.5-2 parts of thermal conductive dispersant, 2 parts of self-healing compound, 0.5-1 part of silicone defoamer, and 1 part of carbon black powder; wherein the self-healing compound is a compound prepared by Diels-Alder reaction;

[0008] The component B is cashew nut shell oil polyol.

[0009] The present invention adds a compound prepared by a DA reaction to an epoxy-modified isocyanate oligomer, and utilizes a reversible DA reaction to construct a self-healing network, so that the coating formed by the coating can be restored by heating after being scratched or impacted; the self-healing temperature of the existing self-healing coatings prepared by utilizing DA reactants is mostly higher than 120°C, and the higher the temperature required for self-healing, the more difficult it is to perform the self-healing work; therefore, in order to reduce the self-healing temperature of the coating, the present invention innovatively adds cyclopentadiene as a capture agent in the nucleophilic substitution reaction of dimethyl N-cyanodithioimidate and potassium isopropyl cyanodithiocarbamate on the basis of the above, so that the generated self-healing polymer has a lower reaction temperature and good stability, thereby reducing the temperature required for self-healing. At the same time, a thermally conductive dispersant with good thermal conductivity is added. The mechanism of action of the dispersant is to change the surface properties of solid particles through adsorption to enhance their dispersibility; then, the thermally conductive dispersant in the present invention is adsorbed on components such as rutile titanium dioxide, fumed silica, and carbon black powder, which can not only make each component evenly dispersed, but also make each evenly dispersed component have a certain thermal conductivity, so that heat is transferred faster in the coating. The temperature of the coating self-repairing of the present invention is within 120°C.

[0010] In the present invention, component A and component B undergo a cross-linking curing reaction after being mixed, and the main reaction mechanism is -NCO + HO-= -NH-COO-. This cross-linking curing reaction is an exothermic reaction, and the coating will heat up during curing. After the temperature rises, the DA reverse reaction and the DA reaction in the coating will occur simultaneously, which promotes the formation of a covalent bond between the epoxy-modified isocyanate oligomer and the self-healing compound, thereby forming a coating with stable performance.

[0011] The coating of the present invention mainly adopts an organic-inorganic hybrid system and a technology combining large molecules and small molecules. The coating does not require the addition of any organic solvents or diluents when used, and the VOC emission is less than 40g / L (national standard 100g / L, GB30981-2020).

[0012] Furthermore, the self-healing compound in component A is prepared by the following method:

[0013] A. Add dimethyl N-cyanodithioimidocarbonate, cyclopentadiene, and potassium isopropyl cyanodithiocarbamate into a container, mix at a stirring speed of 800 r / min, and react at 60° C. and a vacuum degree of ≤0.08 MPa for one hour to obtain a first intermediate;

[0014] B. Stirring isophorone diisocyanate and the first intermediate in a mixing container at a stirring speed of 800 r / min, and then using tetrahydrofuran as a catalyst to react at 55° C. for 24 hours to obtain a self-healing compound.

[0015] Based on the DA reaction, the self-healing compound prepared by the present invention using N-cyanodithioimidodimethyl carbonate, cyclopentadiene, potassium isopropyl cyanodithiocarbamate, and isophorone diisocyanate as main raw materials has good compatibility with epoxy-modified isocyanate oligomers, and the two can be evenly mixed; in addition, the dynamic covalent bonds formed in the self-healing compound of the present invention can be reconnected within 120° C. after being broken.

[0016] Furthermore, the epoxy-modified isocyanate oligomer in component A is prepared by the following method:

[0017] 70-75 parts of polyethylene adipate-1,4-butanediol ester diol and 0.05-0.06 parts of catalyst dibutyltin dilaurate were stirred and mixed at a stirring speed of 300 r / min, heated to 120°C, and dehydrated for 1 hour under the condition of maintaining a vacuum degree of ≤0.08 MPa; then cooled to 70°C, increased the stirring speed to 500 r / min, added 8-10 parts of dimethylol propionic acid and mixed for 10 minutes, and then 10-12 parts of isophorone diisocyanate were slowly added dropwise, and after the addition was completed, the temperature was raised to 85°C and reacted for 1.5 hours to obtain a prepolymer, and after the prepolymer was cooled to 40°C, E-44 epoxy resin was added, and the temperature was raised to 70°C and reacted for 1 hour to obtain an epoxy-modified polyurethane oligomer; wherein, the amount of E-44 epoxy resin added was 10-12% of the mass of the prepolymer.

[0018] The epoxy-modified isocyanate oligomer prepared by the above method is one of the main components of the coating, so that the coating has good film-forming properties, and the epoxy-modified isocyanate oligomer has good compatibility with inorganic substances such as rutile titanium dioxide, fumed silica, and carbon black powder, and after compounding, the coating also has good salt resistance, corrosion resistance and other properties. The coating prepared by the present invention is suitable for marine environments.

[0019] Furthermore, the mass ratio of isophorone diisocyanate to the first intermediate is 1:1; and the amount of tetrahydrofuran added is 10% of the isophorone diisocyanate.

[0020] Furthermore, the first intermediate is prepared by the following method: by weight, 1 part of N-cyanodithioimidocarbonate dimethyl ester, 3 parts of cyclopentadiene, and 1 part of cyanodithiocarbamic acid isopropyl ester potassium salt are added into a container, mixed at a stirring speed of 800 r / min, and reacted at 60° C. and a vacuum degree of ≤0.08 MPa for one hour to obtain the first intermediate.

[0021] Furthermore, the thermally conductive dispersant comprises the following components in parts by weight: 100 parts of esterified modified styrene maleic anhydride copolymer and 25-26 parts of magnesium aluminum silicate modified graphene oxide.

[0022] Furthermore, the magnesium aluminum silicate modified graphene oxide is prepared by the following method: using methyl orthosilicate, aluminum chloride and magnesium chloride as main raw materials to prepare magnesium aluminum silicate sol; adding graphene oxide to the magnesium aluminum silicate sol and mixing them evenly, aging for 2-3 hours, then washing, calcining at 500°C and crushing to obtain magnesium aluminum silicate modified graphene oxide.

[0023] Furthermore, the mass ratio of methyl orthosilicate, aluminum chloride and magnesium chloride is 2:10:5.

[0024] Furthermore, the particle size of the rutile titanium dioxide is 200-400 nm, the particle size of the fumed silica is 7-40 nm, and the particle size of the carbon black powder is 20-50 nm.

[0025] The method for preparing a solvent-free marine environment self-repairing anti-corrosion coating comprises the following steps:

[0026] S1, preparing component A, comprising the following specific steps:

[0027] S1.1, preparation of epoxy modified isocyanate oligomer: 70-75 parts of polyethylene adipate glycol-1,4-butanediol ester diol and 0.05-0.06 parts of catalyst dibutyltin dilaurate were stirred and mixed at a stirring speed of 300 r / min, heated to 120°C, and dehydrated for 1 hour under the condition of maintaining a vacuum degree of ≤0.08 MPa; then cooled to 70°C, increased the stirring speed to 500 r / min, added 8-10 parts of dimethylol propionic acid and mixed for 10 minutes, and then 10-12 parts of isophorone diisocyanate were slowly added dropwise, and after the addition was completed, the temperature was raised to 85°C and reacted for 1.5 hours to obtain a prepolymer, and after the prepolymer was cooled to 40°C, E-44 epoxy resin was added, and the temperature was raised to 70°C and reacted for 1 hour to obtain an epoxy modified polyurethane oligomer, which was set aside;

[0028] S1.2, prepare a self-healing compound: add dimethyl N-cyanodithioimidocarbonate, cyclopentadiene, and potassium isopropyl cyanodithiocarbamate into a container, mix at a stirring speed of 800 r / min, and react at 60° C. and a vacuum degree of ≤0.08 MPa for one hour to obtain a first intermediate; stir isophorone diisocyanate and the first intermediate in a mixing container at a stirring speed of 800 r / min, and then use tetrahydrofuran as a catalyst to react at 55° C. for 24 hours to obtain a self-healing compound for standby use;

[0029] S1.3, mixing: at 70°C, add the self-healing compound to the epoxy-modified polyurethane oligomer, mix at a stirring speed of 500 r / min for 1 hour, then cool to 50°C, add a thermal conductive dispersant, continue stirring for 10 minutes, then add rutile titanium dioxide, fumed silica, silicone defoamer, and carbon black powder, increase the stirring speed to 800 r / min, and stir for 30 minutes to obtain component A for standby use;

[0030] S2, obtaining component B: component B is cashew nut shell oil polyol;

[0031] S3. Mix component A and component B: Evenly mix component A and component B to obtain a solvent-free marine environment self-healing anti-corrosion coating. The solvent-free marine environment self-healing anti-corrosion coating is applied to the metal surface that needs to be protected from corrosion. After drying and film formation, a coating with anti-corrosion properties is formed. The self-healing temperature of the coating is 40-120°C.

[0032] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0033] 1. The solvent-free marine environment self-repairing anti-corrosion coating of the present invention is prepared by adding DA to epoxy-modified isocyanate oligomers, and a self-repairing network is constructed by using a reversible reaction of DA, so that the coating formed by the coating can be restored by heating after being scratched or impacted;

[0034] 2. In the present invention, component A and component B undergo a cross-linking curing reaction after being mixed. This cross-linking curing reaction is an exothermic reaction. The coating will heat up during curing. After the temperature rises, the DA reverse reaction and the DA reaction in the coating will occur simultaneously, which promotes the formation of a covalent bond between the epoxy-modified isocyanate oligomer and the self-healing compound, thereby forming a coating with stable performance;

[0035] 3. In order to lower the self-healing temperature of the coating, the present invention adds a thermally conductive dispersant with good thermal conductivity, which can not only make the various components evenly dispersed, but also make each evenly dispersed component have a certain thermal conductivity, so that heat is transferred faster in the coating, thereby reducing the temperature required for self-healing. The self-healing temperature of the coating of the present invention is within 120°C.

[0036] 4. The present invention mainly adopts an organic-inorganic hybrid system and a technology combining large molecules and small molecules. The coating does not require any organic solvents or diluents when used, and the VOC emission is less than 40g / L (national standard 100g / L, GB30981-2020). BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative work, among which:

[0038] Figure 1 is a microscopic image of a coating with knife marks in Example 5 of the present invention;

[0039] Figure 2 is a microscopic image of the coating after self-repair in Example 5 of the present invention; DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0042] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0043] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0044] Example 1

[0045] A preferred embodiment of the present invention provides a solvent-free marine environment self-repairing anti-corrosion coating, comprising component A and component B, wherein the mass ratio of component A to component B is 100:29;

[0046] The component A comprises the following components in parts by weight: 50-55 parts of epoxy modified isocyanate oligomer, 30-35 parts of rutile titanium dioxide, 2-4 parts of fumed silica, 1.5-2 parts of thermal conductive dispersant, 2 parts of self-healing compound, 0.5-1 part of silicone defoamer, and 1 part of carbon black powder; wherein the self-healing compound is a compound prepared by Diels-Alder reaction; the particle size of the rutile titanium dioxide is 200-400nm, the particle size of the fumed silica is 7-40nm, and the particle size of the carbon black powder is 20-50nm;

[0047] The component B is cashew nut shell oil polyol;

[0048] The self-healing compound in component A is prepared by the following method:

[0049] A. In parts by weight, 1 part of dimethyl N-cyanodithioimidocarbonate, 3 parts of cyclopentadiene, and 1 part of potassium isopropyl cyanodithiocarbamate are added into a container, mixed at a stirring speed of 800 r / min, and reacted for one hour at 60° C. and a vacuum degree of ≤0.08 MPa to obtain a first intermediate; the CAS number of dimethyl N-cyanodithioimidocarbonate in the present invention is 10191-60-3, and the CAS number of potassium isopropyl cyanodithiocarbamate is 36598-22-8;

[0050] B. Stirring isophorone diisocyanate and the first intermediate in a mixing container at a stirring speed of 800 r / min, and then using tetrahydrofuran as a catalyst to react at 55° C. for 24 hours to obtain a self-healing compound; the mass ratio of the isophorone diisocyanate to the first intermediate is 1:1; the amount of tetrahydrofuran added is 10% of the isophorone diisocyanate.

[0051] The epoxy-modified isocyanate oligomer in component A is prepared by the following method:

[0052] 70-75 parts of polyethylene adipate-1,4-butanediol ester diol and 0.05-0.06 parts of catalyst dibutyltin dilaurate were stirred and mixed at a stirring speed of 300 r / min, heated to 120°C, and dehydrated for 1 hour under the condition of maintaining a vacuum degree of ≤0.08 MPa; then cooled to 70°C, increased the stirring speed to 500 r / min, added 8-10 parts of dimethylol propionic acid and mixed for 10 minutes, and then 10-12 parts of isophorone diisocyanate were slowly added dropwise, and after the addition was completed, the temperature was raised to 85°C and reacted for 1.5 hours to obtain a prepolymer, and after the prepolymer was cooled to 40°C, E-44 epoxy resin was added, and the temperature was raised to 70°C and reacted for 1 hour to obtain an epoxy-modified polyurethane oligomer; wherein, the amount of E-44 epoxy resin added was 10-12% of the mass of the prepolymer.

[0053] The thermally conductive dispersant comprises the following components in parts by weight: 100 parts of esterified modified styrene maleic anhydride copolymer, 25-26 parts of magnesium aluminum silicate modified graphene oxide;

[0054] The magnesium aluminum silicate modified graphene oxide is prepared by the following method: using methyl orthosilicate, aluminum chloride and magnesium chloride as main raw materials to prepare magnesium aluminum silicate sol; adding graphene oxide to the magnesium aluminum silicate sol and mixing them evenly, aging for 2-3 hours, then washing, calcining at 500° C. and crushing to obtain magnesium aluminum silicate modified graphene oxide; wherein the mass ratio of methyl orthosilicate, aluminum chloride and magnesium chloride is 2:10:5.

[0055] The method for preparing a solvent-free marine environment self-repairing anti-corrosion coating comprises the following steps:

[0056] S1, preparing component A, comprising the following specific steps:

[0057] S1.1, preparation of epoxy modified isocyanate oligomer: 70-75 parts of polyethylene adipate glycol-1,4-butanediol ester diol and 0.05-0.06 parts of catalyst dibutyltin dilaurate were stirred and mixed at a stirring speed of 300 r / min, heated to 120°C, and dehydrated for 1 hour under the condition of maintaining a vacuum degree of ≤0.08 MPa; then cooled to 70°C, increased the stirring speed to 500 r / min, added 8-10 parts of dimethylol propionic acid and mixed for 10 minutes, and then 10-12 parts of isophorone diisocyanate were slowly added dropwise, and after the addition was completed, the temperature was raised to 85°C and reacted for 1.5 hours to obtain a prepolymer, and after the prepolymer was cooled to 40°C, E-44 epoxy resin was added, and the temperature was raised to 70°C and reacted for 1 hour to obtain an epoxy modified polyurethane oligomer, which was set aside;

[0058] S1.2, prepare a self-healing compound: add dimethyl N-cyanodithioimidocarbonate, cyclopentadiene, and potassium isopropyl cyanodithiocarbamate into a container, mix at a stirring speed of 800 r / min, and react at 60° C. and a vacuum degree of ≤0.08 MPa for one hour to obtain a first intermediate; stir isophorone diisocyanate and the first intermediate in a mixing container at a stirring speed of 800 r / min, and then use tetrahydrofuran as a catalyst to react at 55° C. for 24 hours to obtain a self-healing compound for standby use;

[0059] S1.3, mixing: at 70°C, add the self-healing compound to the epoxy-modified polyurethane oligomer, mix at a stirring speed of 500 r / min for 1 hour, then cool to 50°C, add a thermal conductive dispersant, continue stirring for 10 minutes, then add rutile titanium dioxide, fumed silica, silicone defoamer, and carbon black powder, increase the stirring speed to 800 r / min, and stir for 30 minutes to obtain component A for standby use;

[0060] S2, obtaining component B: component B is cashew nut shell oil polyol;

[0061] S3. Mix component A and component B: Evenly mix component A and component B to obtain a solvent-free marine environment self-healing anti-corrosion coating. The solvent-free marine environment self-healing anti-corrosion coating is applied to the metal surface that needs to be protected from corrosion. After drying and film formation, a coating with anti-corrosion properties is formed. The self-healing temperature of the coating is 40-120°C.

[0062] Example 2

[0063] This embodiment is based on Example 1, and is different from Example 1 in that a preferred embodiment of the present invention provides a solvent-free marine environment self-healing anti-corrosion coating, including component A and component B, and the mass ratio of component A to component B is 100:33.

[0064] Example 3

[0065] This embodiment is based on Embodiment 1, but is different from Embodiment 1 in that a preferred embodiment of the present invention provides a solvent-free marine environment self-healing anti-corrosion coating, comprising component A and component B, and the mass ratio of component A to component B is 100:35.

[0066] Example 4

[0067] Based on Example 2, this embodiment further optimizes Example 2. Component A in this embodiment includes the following components in parts by weight: 50 parts of epoxy-modified isocyanate oligomer, 30-35 parts of rutile titanium dioxide, 2-4 parts of fumed silica, 1.5-2 parts of thermal conductive dispersant, 2 parts of self-healing compound, 0.5-1 part of silicone defoaming agent, and 1 part of carbon black powder; wherein the self-healing compound is a compound prepared by Diels-Alder reaction; the particle size of the rutile titanium dioxide is 200-400nm, the particle size of the fumed silica is 7-40nm, and the particle size of the carbon black powder is 20-50nm; and component B is cashew nut shell oil polyol.

[0068] Example 5

[0069] Based on Example 2, this embodiment further optimizes Example 2. Component A in this embodiment includes the following components in parts by weight: 52.5 parts of epoxy-modified isocyanate oligomer, 30-35 parts of rutile titanium dioxide, 2-4 parts of fumed silica, 1.5-2 parts of thermally conductive dispersant, 2 parts of self-healing compound, 0.5-1 part of silicone defoaming agent, and 1 part of carbon black powder; wherein the self-healing compound is a compound prepared by Diels-Alder reaction; the particle size of the rutile titanium dioxide is 200-400nm, the particle size of the fumed silica is 7-40nm, and the particle size of the carbon black powder is 20-50nm; and component B is cashew nut shell oil polyol.

[0070] Example 6

[0071] Based on Example 2, this embodiment further optimizes Example 2. Component A in this embodiment includes the following components in parts by weight: 55 parts of epoxy-modified isocyanate oligomer, 30-35 parts of rutile titanium dioxide, 2-4 parts of fumed silica, 1.5-2 parts of thermal conductive dispersant, 2 parts of self-healing compound, 0.5-1 part of silicone defoaming agent, and 1 part of carbon black powder; wherein the self-healing compound is a compound prepared by Diels-Alder reaction; the particle size of the rutile titanium dioxide is 200-400nm, the particle size of the fumed silica is 7-40nm, and the particle size of the carbon black powder is 20-50nm; and component B is cashew nut shell oil polyol.

[0072] Comparative Example 1

[0073] Based on Example 2, this comparative example is different from Example 2 in that component A of this comparative example does not include a self-healing compound.

[0074] Comparative Example 2

[0075] Based on Example 2, the difference between this comparative example and Example 2 is that the dispersant in component A of this comparative example is a polyacrylate type dispersant, and the specific type is not limited.

[0076] Comparative Example 3

[0077] Based on Example 2, the difference between this comparative example and Example 2 is that the dispersant in component A of this comparative example is only esterified modified styrene maleic anhydride copolymer.

[0078] Comparative Example 4

[0079] Based on Example 2, the difference between this comparative example and Example 2 is that the dispersant in component A of this comparative example is only magnesium aluminum silicate modified graphene oxide.

[0080] Comparative Example 5

[0081] Based on Example 2, this comparative example is different from Example 2 in that the dispersant in component A of this comparative example is 100 parts of esterified modified styrene maleic anhydride copolymer and 25-26 parts of graphene oxide.

[0082] Comparative Example 6

[0083] Based on Example 1, this comparative example is different from Example 1 in that the self-healing compound in component A of this comparative example is 1 part.

[0084] Comparative Example 7

[0085] Based on Example 1, this comparative example is different from Example 1 in that the self-healing compound in component A of this comparative example is 3 parts.

[0086] Comparative Example 8

[0087] Based on Example 1, the difference between this comparative example and Example 1 is that no N-cyanodithioimidocarbonate dimethyl ester is added to the self-healing compound of this comparative example.

[0088] Comparative Example 9

[0089] Based on Example 1, this comparative example is different from Example 1 in that potassium isopropyl cyanodithiocarbamate is not added to the self-healing compound of this comparative example.

[0090] Test Example 1

[0091] VOC emission detection: According to the national standard 100g / L, GB30981-202, the VOC emission of the coatings prepared in Examples 1-6 was detected. The results are shown in Table 1.

[0092] Table 1 VOC emission test results

[0093] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 VOC emissions <40g / L <40g / L <40g / L <40g / L <40g / L <40g / L

[0094] Test Example 2

[0095] Salt resistance test: The coatings prepared in Examples 1-6 and Comparative Examples 1-9 were tested for salt spray resistance; the dried coating samples were placed in a salt spray test box, all coating thicknesses were kept consistent, the temperature was set at 35°C, continuous spraying, and salt spray deposition was 1-2 mL / h; the salt spray test solution was a 4wt% sodium chloride aqueous solution, and the coating samples were observed on time to observe whether the coating had abnormal phenomena such as rust, cracks, blistering, bulging, peeling, etc. The results are shown in Table 2.

[0096] Table 2 Test results of coating salt spray resistance

[0097] Coating salt spray resistance test 360h Coating salt spray resistance test 720h Coating salt spray resistance test 1080h Example 1 No abnormal phenomenon No abnormal phenomenon No abnormal phenomenon Example 2 No abnormal phenomenon No abnormal phenomenon No abnormal phenomenon Example 3 No abnormal phenomenon No abnormal phenomenon No abnormal phenomenon Example 4 No abnormal phenomenon No abnormal phenomenon No abnormal phenomenon Example 5 No abnormal phenomenon No abnormal phenomenon No abnormal phenomenon Example 6 No abnormal phenomenon No abnormal phenomenon No abnormal phenomenon Comparative Example 1 No abnormal phenomenon Bubbling occurs Rust, cracks, and blistering Comparative Example 2 No abnormal phenomenon No abnormal phenomenon No abnormal phenomenon Comparative Example 3 No abnormal phenomenon No abnormal phenomenon No abnormal phenomenon Comparative Example 4 No abnormal phenomenon No abnormal phenomenon Bubbling occurs Comparative Example 5 No abnormal phenomenon No abnormal phenomenon Bubbling occurs Comparative Example 6 No abnormal phenomenon No abnormal phenomenon Bubbling occurs Comparative Example 7 No abnormal phenomenon No abnormal phenomenon No abnormal phenomenon Comparative Example 8 No abnormal phenomenon No abnormal phenomenon Bubbling occurs Comparative Example 9 No abnormal phenomenon No abnormal phenomenon Bubbling occurs

[0098] Test Example 3

[0099] Self-repairing performance: The coatings prepared in Examples 1-6 and Comparative Examples 1-9 were tested for self-repairing performance, and the coating knife mark repair time at different temperatures was tested. The specific method is: the coating thickness of all coating samples is kept consistent, and a stroke is made on the coating sample with the same knife to form a "I"-shaped knife mark with a length of 2-3 cm. The coating sample is then placed under different temperature environments, and the knife mark repair time of the coating sample is tested. The knife mark disappears completely as seen by the naked eye. The results are shown in Table 3.

[0100] Table 3 Self-repair performance test results

[0101] 40℃ Knife mark repair time 60℃ Knife mark repair time 80℃ Knife mark repair time 100℃ Knife mark repair time 120℃ knife mark repair time 130℃ Knife mark repair time Example 1 >60min 30-33min 24-27min 17-22min 10-15min 12-14min Example 2 >60min 25-28min 18-20min 11-14min 5-8min 5-9min Example 3 >60min 32-36min 28-30min 20-24min 13-16min 13-15min Example 4 >60min 26.5-28min 19-20min 13-14min 7-8min 7-9min Example 5 >60min 25-26min 18-19min 11-12min 5-6min 5-6min Example 6 >60min 27-28min 19-20min 13-14min 7-8min 7-8min Comparative Example 1 No fix No fix No fix No fix No fix No fix Comparative Example 2 No fix >60min >60min >60min >60min >60min Comparative Example 3 No fix >60min >60min >60min >60min >60min Comparative Example 4 No fix >60min >60min 55-60min 40-46min 38-40min Comparative Example 5 >60min >60min 40-43min 27-32min 20-25min 20-25min Comparative Example 6 No fix >60min 43-45min 29-34min 23-25min 20-25min Comparative Example 7 >60min 30-31min 24-26min 16-20min 10-12min 11-12min Comparative Example 8 No fix No fix >60min 40-50min 35-38min 20-22min Comparative Example 9 No fix No fix >60min 40-50min 35-36min 20-25min

[0102] The present invention has a repairing effect on knife marks within 40-120°C. At 120°C, the knife mark repair time can reach 5-6 minutes. The microscopic image of the coating sample containing knife marks under the ratio of Example 5 of the present invention is shown in Figure 1. At 100°C, the microscopic image of the coating sample after repair for 12 minutes is shown in Figure 2. Figure 2 As shown, compared Figure 1 and Figure 2 , indicating that the coating of the present invention has a self-repairing function.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made by any technician familiar with the field within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A solvent-free marine environment self-repairing anti-corrosion coating, characterized by: It comprises component A and component B, wherein the mass ratio of component A to component B is 100:29-35; The component A comprises the following components in parts by weight: 50-55 parts of epoxy-modified isocyanate oligomer, 30-35 parts of rutile titanium dioxide, 2-4 parts of fumed silica, 1.5-2 parts of thermal conductive dispersant, 2 parts of self-healing compound, 0.5-1 part of silicone defoamer, and 1 part of carbon black powder; wherein the self-healing compound is a compound prepared by Diels-Alder reaction; The component B is cashew nut shell oil polyol; The self-healing compound in component A is prepared by the following method: A. Add dimethyl N-cyanodithioimidocarbonate, cyclopentadiene, and potassium isopropyl cyanodithiocarbamate into a container, mix at a stirring speed of 800 r / min, and react at 60° C. and a vacuum degree of ≤0.08 MPa for one hour to obtain a first intermediate; B. Mixing isophorone diisocyanate and the first intermediate in a mixing container at a stirring speed of 800 r / min, and then using tetrahydrofuran as a catalyst, reacting at 55° C. for 24 hours to obtain a self-healing compound; The thermally conductive dispersant comprises the following components in parts by weight: 100 parts of esterified modified styrene maleic anhydride copolymer, 25-26 parts of magnesium aluminum silicate modified graphene oxide; The mass ratio of isophorone diisocyanate to the first intermediate is 1:1; the amount of tetrahydrofuran added is 10% of isophorone diisocyanate; The first intermediate is prepared by the following method: by weight, 1 part of N-cyanodithioimidocarbonate dimethyl ester, 3 parts of cyclopentadiene, and 1 part of cyanodithiocarbamic acid isopropyl ester potassium salt are added into a container and mixed at a stirring speed of 800r / min, and reacted at 60°C and a vacuum degree of ≤0.08MPa for one hour to obtain the first intermediate.

2. The solvent-free marine environment self-repairing anti-corrosion coating according to claim 1, characterized in that: The epoxy-modified isocyanate oligomer in component A is prepared by the following method: 70-75 parts of polyethylene adipate-1,4-butanediol ester diol and 0.05-0.06 parts of catalyst dibutyltin dilaurate were stirred and mixed at a stirring speed of 300 r / min, heated to 120°C, and dehydrated for 1 hour under the condition of maintaining a vacuum degree of ≤0.08 MPa; then cooled to 70°C, increased the stirring speed to 500 r / min, added 8-10 parts of dimethylol propionic acid and mixed for 10 minutes, and then 10-12 parts of isophorone diisocyanate were slowly added dropwise, and after the addition was completed, the temperature was raised to 85°C and reacted for 1.5 hours to obtain a prepolymer, and after the prepolymer was cooled to 40°C, E-44 epoxy resin was added, and the temperature was raised to 70°C and reacted for 1 hour to obtain an epoxy-modified polyurethane oligomer; wherein, the amount of E-44 epoxy resin added was 10-12% of the mass of the prepolymer.

3. The solvent-free marine environment self-repairing anti-corrosion coating according to claim 1, characterized in that: The magnesium aluminum silicate modified graphene oxide is prepared by the following method: using methyl orthosilicate, aluminum chloride and magnesium chloride as raw materials to prepare magnesium aluminum silicate sol; adding graphene oxide to the magnesium aluminum silicate sol and mixing them evenly, aging for 2-3 hours, then washing, calcining at 500° C. and crushing to obtain magnesium aluminum silicate modified graphene oxide.

4. The solvent-free marine environment self-repairing anti-corrosion coating according to claim 3, characterized in that: The mass ratio of methyl orthosilicate, aluminum chloride and magnesium chloride is 2:10:

5.

5. The solvent-free marine environment self-repairing anti-corrosion coating according to claim 1, characterized in that: The particle size of the rutile titanium dioxide is 200-400 nm, the particle size of the fumed silicon dioxide is 7-40 nm, and the particle size of the carbon black powder is 20-50 nm.

6. A method for preparing a solvent-free marine environment self-repairing anti-corrosion coating according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, preparing component A, comprising the following specific steps: S1.1, preparation of epoxy modified isocyanate oligomer: 70-75 parts of polyethylene adipate glycol-1,4-butanediol ester diol and 0.05-0.06 parts of catalyst dibutyltin dilaurate were stirred and mixed at a stirring speed of 300 r / min, heated to 120°C, and dehydrated for 1 hour under the condition of maintaining a vacuum degree of ≤0.08 MPa; then cooled to 70°C, increased the stirring speed to 500 r / min, added 8-10 parts of dimethylol propionic acid and mixed for 10 minutes, and then 10-12 parts of isophorone diisocyanate were slowly added dropwise, and after the addition was completed, the temperature was raised to 85°C and reacted for 1.5 hours to obtain a prepolymer, and after the prepolymer was cooled to 40°C, E-44 epoxy resin was added, and the temperature was raised to 70°C and reacted for 1 hour to obtain an epoxy modified polyurethane oligomer, which was set aside; S1.2, prepare a self-healing compound: add dimethyl N-cyanodithioimidocarbonate, cyclopentadiene, and potassium isopropyl cyanodithiocarbamate into a container, mix at a stirring speed of 800 r / min, and react at 60° C. and a vacuum degree of ≤0.08 MPa for one hour to obtain a first intermediate; stir isophorone diisocyanate and the first intermediate in a mixing container at a stirring speed of 800 r / min, and then use tetrahydrofuran as a catalyst to react at 55° C. for 24 hours to obtain a self-healing compound for standby use; S1.3, mixing: at 70°C, add the self-healing compound to the epoxy-modified polyurethane oligomer, mix at a stirring speed of 500 r / min for 1 hour, then cool to 50°C, add a thermal conductive dispersant, continue stirring for 10 minutes, then add rutile titanium dioxide, fumed silica, silicone defoamer, and carbon black powder, increase the stirring speed to 800 r / min, and stir for 30 minutes to obtain component A for standby use; S2, obtaining component B: component B is cashew nut shell oil polyol; S3. Mix component A and component B: Evenly mix component A and component B to obtain a solvent-free marine environment self-healing anti-corrosion coating. The solvent-free marine environment self-healing anti-corrosion coating is applied to the metal surface that needs to be protected from corrosion. After drying and film formation, a coating with anti-corrosion properties is formed. The self-healing temperature of the coating is 40-120°C.

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