A corrosion-resistant epoxy resin coating

Abstract

The present invention relates to the technical field of coatings and discloses a corrosion-resistant epoxy resin coating. The corrosion-resistant epoxy resin coating consists of two parts: component 1 and component 2, wherein component 1 includes the following raw materials: bisphenol A epoxy resin, anti-corrosion illite, defoaming agent, antioxidant, ultraviolet absorber, and deionized water; component 2 includes the following raw materials: a heat-resistant cross-linking curing agent and a leveling agent. The present invention prepares anti-corrosion illite and a heat-resistant cross-linking curing agent and participates in the preparation process of the epoxy resin coating, so that the prepared epoxy resin coating has excellent mechanical strength, wear resistance, corrosion resistance and heat resistance, can meet the use requirements in high temperature environments and corrosive media, and the cured coating is wear-resistant, scratch-resistant, and not easy to break, and has a long service life.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, in particular to a corrosion-resistant epoxy resin coating. Background Art

[0002] Corrosion is a chemical change process that is ubiquitous in nature. It can be defined as changes that occur on the surface of materials due to chemical or electrochemical erosion. In industrial production, corrosion not only causes material damage, increases replacement costs, and causes economic losses, but also easily accelerates the aging process of equipment, thereby shortening the service life of the equipment and increasing operating and maintenance costs. Especially in the fields of petroleum, chemical, and electric power, corrosion of equipment and pipelines may lead to accidents such as leakage and explosion, seriously affecting the safety of life and property.

[0003] In order to prevent the occurrence of corrosion, people have developed many anti-corrosion methods, including electrochemical protection, anti-corrosion alloys, material surface modification, paint anti-corrosion, etc. Among them, paint anti-corrosion is popular because of its easy and simple operation, wide adaptability, low cost and easy maintenance. Epoxy resin coating is a high-performance coating prepared by adding various curing agents, pigments, fillers and other additives with epoxy resin as the main film-forming substance. Due to the highly polar hydroxyl groups and ether bonds in its structure, the prepared epoxy resin coating has excellent adhesion and can adapt to the coating requirements of various material surfaces. However, ordinary epoxy resin coatings have average high temperature resistance and corrosion resistance, insufficient mechanical strength, and are difficult to exist stably for a long time in high temperature and corrosive media in actual use, which seriously limits the use of epoxy resin coatings.

[0004] Patent No. CN115029046B discloses an epoxy resin coating and a preparation method thereof. The epoxy resin coating is obtained by uniformly mixing epoxy resin, polycaprolactone functionalized silica, nano-kaolin, defoamer, epoxy curing agent, wetting agent, leveling agent, modified rutile titanium dioxide, composite antibacterial agent, and water. The epoxy resin coating prepared by this patent has excellent salt spray resistance, can block the erosion of corrosive media, and exists stably in corrosive media. It also has excellent wear resistance, impact resistance and hardness, and has good antibacterial properties. It can meet the use requirements in various environments and has a long service life. However, the introduction of a large number of nanoparticles in this coating may affect the construction performance and cost of the coating. Improper operation can easily cause the agglomeration of nanoparticles, thereby affecting the performance of the coating. Summary of the Invention

[0005] The purpose of the present invention is to provide a corrosion-resistant epoxy resin coating, which solves the problems that ordinary epoxy resin coatings have poor high temperature resistance and corrosion resistance and are easily damaged during friction.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A corrosion-resistant epoxy resin coating consists of two parts, component 1 and component 2. Component 1 comprises the following raw materials in parts by weight: 80-100 parts of bisphenol A epoxy resin, 8-10 parts of anti-corrosion illite, 2-4 parts of defoaming agent, 1-3 parts of antioxidant, 1-2 parts of ultraviolet absorber, and 120-200 parts of deionized water; and component 2 comprises the following raw materials in parts by weight: 30-40 parts of heat-resistant cross-linking curing agent and 3-5 parts of leveling agent.

[0008] Furthermore, the defoaming agent is any one of dimethyl silicone oil defoaming agent and polyoxyethylene defoaming agent; the antioxidant is any one of antioxidant 1010, antioxidant TH-1790, and antioxidant 1024; the ultraviolet absorber is any one of ultraviolet absorber UV-1300 and ultraviolet absorber UV-3030; and the leveling agent is a polyurethane leveling agent.

[0009] Furthermore, the preparation method of the heat-resistant cross-linking curing agent comprises the following steps:

[0010] S1: placing a hydroxychloroacetate resin in acetone, introducing nitrogen to deoxygenate, adding dimethyl monochlorosilane, heating to reflux for reaction, and collecting the product after reduced pressure distillation to obtain a silylated chloroacetate resin;

[0011] S2: Place the silylated chloroacetic acid resin in toluene, mix and stir thoroughly, introduce nitrogen, add 4-methacryloyloxy trimellitic anhydride and a catalyst, raise the temperature to 70-80°C and react for 8-10 hours, collect the product after reduced pressure distillation, and obtain a heat-resistant cross-linking curing agent.

[0012] In this solution, through a heating reflux reaction, the hydroxyl groups in the hydroxychlorovinyl resin structure react with the silicon-chlorine groups in the dimethylmonochlorosilane structure to obtain a silylated chlorovinyl resin containing a silicon-hydrogen bond in the structure. Then, under the action of a catalyst, the silicon-hydrogen bonds in the silylated chlorovinyl resin structure react with the alkenyl groups in the 4-methacryloyloxytrimellitic anhydride structure to obtain a heat-resistant cross-linking curing agent. This heat-resistant cross-linking curing agent contains anhydride groups in its structure and can be used as a curing agent for epoxy resin coatings. It reacts with the epoxy groups in the epoxy resin structure to form a cross-linked structure, significantly improving the heat resistance and corrosion resistance of the coating. At the same time, its structure forms a high-temperature resistant silicon-oxygen bond that can participate in the curing process of the epoxy resin coating, further improving the heat resistance of the coating, making it suitable for use in high-temperature environments and having a long service life.

[0013] Furthermore, in step S1, the heating reflux reaction time is 10-12 hours.

[0014] Furthermore, in step S2, the catalyst is chloroplatinic acid.

[0015] Furthermore, the method for preparing the corrosion-resistant illite comprises the following steps:

[0016] SS1: Place illite in deionized water and ultrasonically disperse it for 10-15 minutes. Then, introduce nitrogen and add naphthalene diisocyanate and dibutyltin dilaurate. Heat to 80-85°C and react for 3-5 hours. Centrifuge, wash, and vacuum dry to obtain modified illite.

[0017] SS2: Place the modified illite in anhydrous ethanol, ultrasonically disperse it for 15-20 minutes, then introduce nitrogen, add 2-methyl-4-heptafluoroisopropylaniline and stannous octoate, heat and stir, filter, wash and dry to obtain corrosion-resistant illite.

[0018] In this solution, under the catalytic action of dibutyltin dilaurate, the hydroxyl groups on the surface of illite react with the isocyanate groups in the naphthalene diisocyanate structure to obtain a modified illite containing isocyanate groups in its structure. Then, under the action of stannous octoate, the isocyanate groups in the modified illite structure react with the amino groups in the 2-methyl-4-heptafluoroisopropylaniline structure to obtain anti-corrosion illite. This anti-corrosion illite, after organic modification, can be uniformly dispersed in epoxy resin coatings. The naphthalene rings in its structure can enhance the wear resistance of the epoxy resin coating. Furthermore, this anti-corrosion illite has a unique lamellar structure that can form a physical barrier in the coating to effectively block the intrusion of corrosive media. Its surface is grafted with an organic fluorine structure, which can effectively improve the corrosion resistance of the epoxy resin coating, further enhancing the corrosion resistance of the coating and making the prepared epoxy resin coating stable in corrosive media. This greatly expands the application field of epoxy resin coatings and extends their service life.

[0019] Furthermore, in step SS1, the particle size of the illite is 0.3-1 μm.

[0020] Furthermore, in step SS2, the temperature of the heating and stirring is 70-80° C., and the time is 5-6 hours.

[0021] Furthermore, the preparation method of the corrosion-resistant epoxy coating comprises the following steps:

[0022] Step 1: Pour bisphenol A epoxy resin, anti-corrosion illite, defoamer, antioxidant, ultraviolet absorber, and deionized water into a mixer, set the speed to 500-600 r / min, and mix thoroughly for 0.5-1 hour to obtain component 1;

[0023] Step 2: Stir the heat-resistant cross-linking curing agent and the leveling agent at a rate of 300-500 r / min for 0.3-0.5 h to obtain component 2.

[0024] Beneficial effects of the present invention:

[0025] The present invention prepares anti-corrosion illite and heat-resistant cross-linking curing agent in the preparation process of epoxy resin coating, so that the prepared epoxy resin coating has excellent mechanical strength, wear resistance, corrosion resistance and heat resistance, can meet the use requirements in high temperature environment and corrosive medium, and the cured coating is wear-resistant, scratch-resistant and not easy to break, and has a long service life.

[0026] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 2 is a thermogravimetric curve of illite, modified illite and anti-corrosion illite in the embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] The preparation methods of the heat-resistant cross-linking curing agent and the anti-corrosion illite in the following examples and comparative examples of the present invention are as follows:

[0031] 1. Preparation of heat-resistant cross-linking curing agent

[0032] S1: 3 g of hydroxychloroacetate resin was placed in 60 ml of acetone, nitrogen was introduced to remove oxygen, 2.6 g of dimethyl monochlorosilane was added, and the mixture was heated under reflux for 10 h. The product was collected after vacuum distillation to obtain a silylated chloroacetate resin;

[0033] S2: Place 3.2 g of silanized chloroacetic acid resin in 80 ml of toluene, mix and stir thoroughly, introduce nitrogen, add 3 g of 4-methacryloyloxy trimellitic anhydride and 0.3 g of chloroplatinic acid, raise the temperature to 70°C and react for 8 hours. Collect the product after reduced pressure distillation to obtain a heat-resistant cross-linking curing agent.

[0034] The content of anhydride groups in the heat-resistant cross-linking curing agent was measured by titration. 2 g of the heat-resistant cross-linking curing agent was weighed as a sample, added to 80 ml of toluene, heated under reflux for 0.5 h and thoroughly mixed. After cooling, an excess of 0.1 mol / L KOH-ethanol standard solution was added, and the mixture was heated under reflux for another 6 h. After cooling, 1 ml of phenolphthalein indicator was added, and the excess KOH-ethanol standard solution was counter-titrated with 0.1 mol / L HCl-isopropanol standard solution. The amount of excess alkali consumed and the amount of acid neutralized were recorded. The content of anhydride groups in the sample was calculated according to the following formula: W = (V-V1) × C × M 酸酐 ×100% / m; where W is the content of anhydride groups in the sample, %; V is the volume of KOH-ethanol solution added, ml; V1 is the volume of HCl-isopropanol standard solution consumed, ml; C is the concentration of KOH-ethanol standard solution, mol / L; M 酸酐 is the molar mass of the anhydride group, g / mol. Calculation shows that the content of anhydride groups in the heat-resistant cross-linking curing agent is 8.62%. This is due to the hydrosilylation reaction between the silicon-hydrogen bonds in the silylated vinyl chloride resin structure and the alkenyl groups in the 4-methacryloyloxy trimellitic anhydride structure, which introduces anhydride groups into the vinyl chloride resin polymer chain segments.

[0035] 2. Preparation of anti-corrosion illite

[0036] SS1: 3 g of illite with a particle size of 0.3 μm was placed in 80 ml of deionized water and ultrasonically dispersed for 10 min. Then, nitrogen was introduced, and 2.8 g of naphthalene diisocyanate and 0.2 g of dibutyltin dilaurate were added. The temperature was raised to 80°C and reacted for 3 h. The modified illite was obtained after centrifugation, washing, and vacuum drying.

[0037] SS2: Place 3.5 g of modified illite in 100 ml of anhydrous ethanol, ultrasonically disperse for 15 minutes, then introduce nitrogen. Add 3 g of 2-methyl-4-heptafluoroisopropylaniline and 0.3 g of stannous octoate. Heat to 70°C and stir for 5 hours. Filter, wash, and dry to obtain corrosion-resistant illite.

[0038] Illite, modified illite and corrosion-resistant illite were analyzed by thermogravimetric analysis. Figure 1It can be seen that the mass retention rate of illite at high temperature is 96.3%, and the lost part is caused by the decomposition of crystalline water in its structure; the mass retention rate of modified illite at high temperature is 48.15%, and the lost part is caused by the thermal decomposition of naphthalene diisocyanate grafted on its surface; the mass retention rate of anti-corrosion illite at high temperature is 24.4%, and the lost part is caused by the thermal decomposition of organic matter grafted on the surface of illite. Example

[0039] Preparation of epoxy resin coating

[0040] Step 1: Pour 80 parts of bisphenol A epoxy resin, 8 parts of anti-corrosion illite, 2 parts of dimethyl silicone oil defoamer, 1 part of antioxidant 1010, 1 part of ultraviolet absorber UV-1300, and 120 parts of deionized water into a mixer, set the speed to 500 r / min, and mix thoroughly for 0.5 h to obtain component 1;

[0041] Step 2: Stir 30 parts of heat-resistant cross-linking curing agent and 3 parts of polyurethane leveling agent at a rate of 300 r / min for 0.3 h to obtain component 2. Example

[0042] Preparation of epoxy resin coating

[0043] Step 1: Pour 90 parts of bisphenol A epoxy resin, 9 parts of anti-corrosion illite, 3 parts of polyoxyethylene defoamer, 2 parts of antioxidant TH-1790, 1.5 parts of ultraviolet absorber UV-3030, and 160 parts of deionized water into a mixer, set the speed to 550 r / min, and mix thoroughly for 0.8 h to obtain component 1;

[0044] Step 2: Stir 35 parts of heat-resistant cross-linking curing agent and 4 parts of polyurethane leveling agent at a rate of 400 r / min for 0.4 h to obtain component 2. Example

[0045] Preparation of epoxy resin coating

[0046] Step 1: Pour 100 parts of bisphenol A epoxy resin, 10 parts of anti-corrosion illite, 4 parts of dimethyl silicone oil defoamer, 2 parts of antioxidant 1024, 2 parts of ultraviolet absorber UV-1300, and 200 parts of deionized water into a mixer, set the speed to 600 r / min, and mix thoroughly for 1 hour to obtain component 1;

[0047] Step 2: Stir 40 parts of heat-resistant cross-linking curing agent and 5 parts of polyurethane leveling agent at a rate of 500 r / min for 0.5 h to obtain component 2.

[0048] Comparative Example 1

[0049] Preparation of epoxy resin coating

[0050] Step 1: Pour 90 parts of bisphenol A epoxy resin, 3 parts of polyoxyethylene defoamer, 2 parts of antioxidant TH-1790, 1.5 parts of ultraviolet absorber UV-3030, and 160 parts of deionized water into a mixer, set the speed to 550 r / min, and mix thoroughly for 0.8 h to obtain component 1;

[0051] Step 2: Stir 35 parts of heat-resistant cross-linking curing agent and 4 parts of polyurethane leveling agent at a rate of 400 r / min for 0.4 h to obtain component 2.

[0052] Comparative Example 2

[0053] Preparation of epoxy resin coating

[0054] Step 1: Pour 90 parts of bisphenol A epoxy resin, 9 parts of anti-corrosion illite, 3 parts of polyoxyethylene defoamer, 2 parts of antioxidant TH-1790, 1.5 parts of ultraviolet absorber UV-3030, and 160 parts of deionized water into a mixer, set the speed to 550 r / min, and mix thoroughly for 0.8 h to obtain component 1;

[0055] Step 2: Stir 35 parts of phthalic anhydride and 4 parts of polyurethane leveling agent at a rate of 400 r / min for 0.4 h to obtain component 2.

[0056] Comparative Example 3

[0057] Preparation of epoxy resin coating

[0058] Step 1: Pour 90 parts of bisphenol A epoxy resin, 9 parts of modified illite, 3 parts of polyoxyethylene defoamer, 2 parts of antioxidant TH-1790, 1.5 parts of ultraviolet absorber UV-3030, and 160 parts of deionized water into a mixer, set the speed to 550 r / min, and mix thoroughly for 0.8 h to obtain component 1;

[0059] Step 2: Stir 35 parts of heat-resistant cross-linking curing agent and 4 parts of polyurethane leveling agent at a rate of 400 r / min for 0.4 h to obtain component 2.

[0060] Performance testing

[0061] The epoxy resin coating component 1 and component 2 prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were mixed and evenly coated on a tinplate that met the specifications. After curing at 120° C. for 5 minutes, the mixture was demoulded to prepare a sample that met the specifications. The sample was subjected to a salt spray test with reference to the standard GB / T1771-2007 to determine the corrosion resistance of the sample. The sample and the sample after treatment at 200° C. for 72 hours were subjected to a tensile strength test with reference to the standard GB / T1040-2006. Taber abrasion test was used to determine the corrosion resistance of the sample. The tester tests the wear resistance of the sample. Two grinding wheels are placed on the sample. The grinding wheel movement speed is set to 40r / min to perform a wear test on the sample. The initial mass of the sample and the mass of the sample after 10,000 revolutions of wear are recorded. The sample wear value is calculated using the following formula: m=m1-m2; where m is the sample wear value, g / 10,000r; m1 is the sample initial mass, g; m2 is the sample mass after wear, g; the smaller the wear value, the better the sample wear resistance; the specific test results are shown in the table below:

[0062]

[0063] It can be seen from the above table that the samples prepared in Examples 1 to 3 all have excellent corrosion resistance, mechanical strength, high temperature resistance and wear resistance, can meet the use requirements in various environments and have a long service life. The sample prepared in Comparative Example 1 does not add anti-corrosion illite, and the sample prepared in Comparative Example 2 directly adds phthalic anhydride as a curing agent without adding a heat-resistant cross-linking curing agent. Therefore, the high temperature resistance, wear resistance and corrosion resistance of the samples prepared in Comparative Example 1 and Comparative Example 2 are not as good as those in the examples. In the sample prepared in Comparative Example 3, modified illite is directly added without adding anti-corrosion illite, and the corrosion resistance is not as good as that in the examples, but the high temperature resistance and wear resistance are at a relatively high level.

[0064] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0065] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the scope defined by the concept of the invention, they should all fall within the scope of protection of the present invention.

Claims

1. A corrosion-resistant epoxy resin coating, characterized in that: The invention comprises component 1 and component 2, wherein component 1 comprises the following raw materials in parts by weight: 80-100 parts of bisphenol A epoxy resin, 8-10 parts of anti-corrosion illite, 2-4 parts of defoaming agent, 1-3 parts of antioxidant, 1-2 parts of ultraviolet absorber, and 120-200 parts of deionized water; and component 2 comprises the following raw materials in parts by weight: 30-40 parts of heat-resistant cross-linking curing agent and 3-5 parts of leveling agent. The method for preparing the anti-corrosion illite comprises the following steps: SS1: Place illite in deionized water and ultrasonically disperse it for 10-15 minutes. Then, introduce nitrogen and add naphthalene diisocyanate and dibutyltin dilaurate. Heat to 80-85°C and react for 3-5 hours. Centrifuge, wash, and vacuum dry to obtain modified illite. SS2: Place the modified illite in anhydrous ethanol, ultrasonically disperse for 15-20 minutes, then introduce nitrogen, add 2-methyl-4-heptafluoroisopropylaniline and stannous octoate, heat and stir, filter, wash and dry to obtain corrosion-resistant illite; The preparation method of the heat-resistant cross-linking curing agent comprises the following steps: S1: placing a hydroxychloroacetate resin in acetone, introducing nitrogen to deoxygenate, adding dimethyl monochlorosilane, heating to reflux for reaction, and collecting the product after reduced pressure distillation to obtain a silylated chloroacetate resin; S2: Place the silylated chloroacetic acid resin in toluene, mix and stir thoroughly, introduce nitrogen, add 4-methacryloyloxy trimellitic anhydride and a catalyst, raise the temperature to 70-80°C and react for 8-10 hours, collect the product after reduced pressure distillation, and obtain a heat-resistant cross-linking curing agent.

2. A corrosion-resistant epoxy resin coating according to claim 1, characterized in that: The defoaming agent is any one of dimethyl silicone oil defoaming agent and polyoxyethylene defoaming agent; the antioxidant is any one of antioxidant 1010, antioxidant TH-1790, and antioxidant 1024; the ultraviolet absorber is any one of ultraviolet absorber UV-1300 and ultraviolet absorber UV-3030; and the leveling agent is a polyurethane leveling agent.

3. The corrosion-resistant epoxy resin coating according to claim 1, characterized in that: In step S1, the heating reflux reaction time is 10-12 hours.

4. The corrosion-resistant epoxy resin coating according to claim 1, characterized in that: In step S2, the catalyst is chloroplatinic acid.

5. The corrosion-resistant epoxy resin coating according to claim 1, characterized in that: In step SS1, the particle size of the illite is 0.3-1 μm.

6. The corrosion-resistant epoxy resin coating according to claim 1, characterized in that: In step SS2, the temperature of the heating and stirring is 70-80° C., and the time is 5-6 hours.

7. The corrosion-resistant epoxy resin coating according to claim 1, characterized in that: The preparation method of the corrosion-resistant epoxy resin coating comprises the following steps: Step 1: Pour bisphenol A epoxy resin, anti-corrosion illite, defoamer, antioxidant, ultraviolet absorber, and deionized water into a mixer, set the speed to 500-600 r / min, and mix thoroughly for 0.5-1 hour to obtain component 1; Step 2: Stir the heat-resistant cross-linking curing agent and the leveling agent at a rate of 300-500 r / min for 0.3-0.5 h to obtain component 2.

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