A quick-drying corrosion-resistant topcoat and its preparation process

Abstract

The present invention relates to the technical field of topcoats, and discloses a quick-drying corrosion-resistant topcoat and a preparation process thereof. The quick-drying corrosion-resistant topcoat is composed of component A and component B; wherein component A includes the following raw materials: epoxy acrylate resin, anti-corrosion resin, mercapto-dimethylbenzene, defoamer, antioxidant, emulsifier, and leveling agent; component B includes the following raw materials: photoinitiator and deionized water; wherein the anti-corrosion resin is prepared by reacting a modified chloroacetic acid resin with 2-amino-5-fluorobenzotrifluoride; the modified chloroacetic acid resin is prepared by reacting a hydroxychloroacetic acid resin with 2-chloroacrylic acid; the mercapto-dimethylbenzene is prepared by reacting a modified dimethylbenzene with mercaptoethylamine; and the modified dimethylbenzene is prepared by intercalating dimethylbenzene with (3-carboxypropyl)trimethylammonium chloride. The topcoat prepared by the present invention has excellent quick-drying properties, wear resistance, and corrosion resistance, greatly expanding the application field of the topcoat.

Description

Technical Field

[0001] The invention relates to the technical field of topcoats, and in particular to a quick-drying corrosion-resistant topcoat and a preparation process thereof. Background Art

[0002] Topcoat is a kind of coating that acts on the surface of objects and plays a decorative and protective role. It is diverse and functional and is widely used in many fields. Nowadays, with the development of science and technology and the progress of industry, people have higher and higher requirements for the beauty and functionality of the surface of objects, and the limitations of traditional ordinary topcoats are gradually emerging.

[0003] The curing speed of topcoats has always been a key factor restricting their widespread application. After application, ordinary topcoats require a long cross-linking reaction to reach the ideal curing state and form a solid paint film. If the curing time is too long, the paint will easily flow along the surface of the coated object under the action of gravity, forming a sagging phenomenon. This not only destroys the aesthetics of the coating and causes its surface to be uneven, but also causes uneven coating thickness. Some areas are thin and easily eroded, while other areas are thick, which is prone to internal stress and increases the risk of cracking. Therefore, ordinary topcoats are difficult to use on objects with uneven surfaces. At the same time, ordinary topcoats are often subjected to physical friction when applied to the surface of objects. Their wear resistance is average and they are easily damaged by long-term friction, requiring frequent repair or replacement. When used in corrosive media, ordinary topcoats have poor corrosion resistance. The coating on the surface of the object will discolor, bubble, or even fall off due to the action of the corrosive medium, which not only seriously affects the aesthetics of the object but also loses its protective effect.

[0004] Patent publication number CN106280867B discloses a high-temperature, anti-corrosion epoxy paint and its preparation method. The prepared epoxy paint has excellent corrosion resistance, rust resistance, salt and alkali resistance, and high-temperature resistance. It is also hard, wear-resistant, and pressure-resistant, not prone to brittle fracture, and has excellent stability and crack resistance. Although the epoxy paint prepared in this patent has many excellent properties and can meet the needs of use in various environments, its curing efficiency is not improved. When applied to irregular surfaces, it is prone to sagging, which reduces the service life of the paint film. Summary of the Invention

[0005] The purpose of the present invention is to provide a quick-drying corrosion-resistant topcoat and a preparation process thereof, which solves the following technical problems: (1) the problem that ordinary topcoats have a short curing time and are prone to sagging after coating, resulting in uneven film thickness; (2) the problem that ordinary topcoats have average corrosion resistance and wear resistance and a short service life.

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

[0007] A quick-drying corrosion-resistant topcoat is composed of component A and component B. Component A comprises the following raw materials in parts by weight: 60-80 parts of epoxy acrylate resin, 25-30 parts of anti-corrosion resin, 12-15 parts of mercapto-benzene, 2-3 parts of defoamer, 3-5 parts of antioxidant, 2-5 parts of emulsifier, and 1-3 parts of leveling agent. Component B comprises the following raw materials in parts by weight: 3-6 parts of photoinitiator and 120-150 parts of deionized water. The anti-corrosion resin is prepared by reacting a modified chloroacetic acid resin with 2-amino-5-fluorobenzotrifluoride; the modified chloroacetic acid resin is prepared by reacting a hydroxychloroacetic acid resin with 2-chloroacrylic acid; the mercapto-benzene is prepared by reacting a modified benzene with mercaptoethylamine; and the modified benzene is prepared by intercalating (3-carboxypropyl)trimethylammonium chloride into benzene.

[0008] Furthermore, the defoaming agent is any one of dimethyl silicone oil and fatty alcohol polyoxyethylene ether; the antioxidant is any one of antioxidant 1010, antioxidant 2246, and antioxidant 1135; the emulsifier is any one of calcium dodecylbenzenesulfonate, sodium dodecyl polyoxyethylene ether sulfate, alkylphenol polyoxyethylene ether sulfonate, sodium dodecylbenzenesulfonate, and sodium dodecyl sulfate; the leveling agent is any one of polybutyl acrylate and polyethyl acrylate; and the photoinitiator is any one of benzoin dimethyl ether, thioxanthone, benzophenone, and 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one.

[0009] Furthermore, the preparation method of the anti-corrosion resin comprises the following steps:

[0010] S1: placing hydroxychloroacetic acid resin and 2-chloroacrylic acid in toluene, stirring and mixing thoroughly, adding p-toluenesulfonic acid, heating to react, and collecting the product after reduced pressure distillation to obtain a modified chloroacetic acid resin;

[0011] S2: Place the modified chloroacetic acid resin and 2-amino-5-fluorobenzotrifluoride in N,N-dimethylformamide, add a catalyst, raise the temperature to 55-65°C and react for 6-8 hours, collect the product after reduced pressure distillation, and obtain an anti-corrosion resin.

[0012] In this scheme, the hydroxyl group in the hydroxychlorovinyl resin structure and the carboxyl group in the 2-chloroacrylic acid structure undergo an esterification reaction under the action of p-toluenesulfonic acid, introducing a double bond into the polymer chain segment of the chlorovinyl resin to obtain a modified chlorovinyl resin. Then, under the action of a catalyst, the active chlorine in the modified chlorovinyl resin structure undergoes a substitution reaction with the amino group in the N,N-dimethylformamide structure of 2-amino-5-fluorotrifluorotoluene to obtain an anti-corrosion resin. This anti-corrosion resin uses the hydroxychlorovinyl resin as a polymer matrix chain segment, and the multiple double bonds introduced in its structure can participate in the curing process of the topcoat. , so that it interacts with the topcoat matrix material, cross-links and entangles to form a tight network structure, thereby effectively enhancing the corrosion resistance and wear resistance of the topcoat. At the same time, organic fluorine is introduced into the anti-corrosion resin structure to make it contain a large number of CF bonds. These bonds have small polarization rates, short bond distances, but large bond energies and excellent chemical stability, and can effectively resist the erosion of corrosive media, further enhancing the corrosion resistance of the topcoat, and enabling it to maintain its structural stability in corrosive media, effectively expanding the use field of the topcoat, and greatly increasing the service life of the topcoat in corrosive media.

[0013] Furthermore, in step S1, the temperature of the temperature-raising reaction is 90-95° C., and the time is 3-5 hours.

[0014] Furthermore, in step S2, the catalyst is potassium carbonate.

[0015] Furthermore, the preparation method of the mercaptolated dickite comprises the following steps:

[0016] SS1: Place dickite in deionized water and ultrasonically disperse for 10-15 minutes. Add (3-carboxypropyl)trimethylammonium chloride and stir thoroughly for 8-10 hours. Filter, wash, and dry to obtain modified dickite.

[0017] SS2: Place the modified dickite in anhydrous ethanol, ultrasonically disperse it for 12-15 minutes, add mercaptoethylamine and a composite catalyst, heat to 60-65°C and react for 5-6 hours, filter, wash and dry to obtain the thiolated dickite.

[0018] In this scheme, (3-carboxypropyl)trimethylammonium chloride with a quaternary ammonium group is used to perform intercalation modification on dickite to obtain modified dickite containing carboxyl groups. Then, under the action of a composite catalyst, the carboxyl groups in the modified dickite structure react with the amino groups in the mercaptoethylamine structure to obtain thiolated dickite. This thiolated dickite has good compatibility with the topcoat matrix material and can effectively enhance the wear resistance of the topcoat. At the same time, its structure has multiple thiols. During the UV curing process of the topcoat, the thiol-ene can undergo a click reaction, which can effectively reduce oxygen inhibition during the UV curing process and form a better cross-linked structure, thereby effectively accelerating the curing process of the topcoat and enabling it to cure quickly. When used for the protection of convex or irregular surfaces, it effectively avoids the problem of uneven paint film thickness caused by topcoat sagging, thereby extending the service life of the paint film.

[0019] Furthermore, in step SS2, the composite catalyst is 4-dimethylaminopyridine and dicyclohexylcarbodiimide in a ratio of 0.3-1:0.9-3.

[0020] A preparation process of a quick-drying corrosion-resistant topcoat comprises the following steps:

[0021] Step 1: Evenly mix epoxy acrylate resin, anti-corrosion resin, mercapto-dimethylbenzene, defoamer, antioxidant, emulsifier, and leveling agent to obtain component A;

[0022] Step 2: Evenly mix the photoinitiator and deionized water to obtain component B.

[0023] Beneficial effects of the present invention:

[0024] The present invention prepares an anti-corrosion resin and mercapto-containing pyroxene in the preparation process of the topcoat, so that the prepared topcoat has excellent wear resistance and corrosion resistance, can meet the use requirements in various environments, and has a long service life. At the same time, the topcoat prepared by the present invention has quick-drying properties, can effectively solve the problem of uneven paint film caused by sagging when the topcoat is used on irregular surfaces, and greatly expands the application field of the topcoat.

[0025] 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

[0026] 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.

[0027] Figure 1 The present invention is a flow chart of the preparation process of the quick-drying corrosion-resistant topcoat. DETAILED DESCRIPTION

[0028] 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.

[0029] The preparation methods of the anti-corrosion resin and mercapto-dipyridinium in the following examples and comparative examples of the present invention are as follows:

[0030] 1. Preparation of anti-corrosion resin

[0031] S1: 3 g of hydroxychloroacetic acid resin and 2.5 g of 2-chloroacrylic acid were placed in 50 ml of toluene, stirred thoroughly, and 0.2 g of p-toluenesulfonic acid was added. The mixture was heated to 90°C and reacted for 3 h. The product was collected after vacuum distillation to obtain a modified chloroacetic acid resin.

[0032] S2: 3.2 g of modified chloroacetic acid resin and 3 g of 2-amino-5-fluorobenzotrifluoride were placed in 80 ml of N,N-dimethylformamide, 0.1 g of potassium carbonate was added, and the temperature was raised to 55°C for reaction for 6 h. The product was collected after reduced pressure distillation to obtain an anti-corrosion resin.

[0033] The nitrogen element analysis of the modified chlorovinyl resin and the anti-corrosion resin using a Carlo Erba 1106 elemental analyzer showed that the modified chlorovinyl resin did not contain nitrogen, while the nitrogen content in the anti-corrosion resin was 6.1%. This was due to the reaction between the active chlorine in the modified chlorovinyl resin structure and the amino group in the 2-amino-5-fluorotrifluorotoluene structure.

[0034] 2. Preparation of thiolated dickite

[0035] SS1: Place 2.5 g of dickite in 100 ml of deionized water, ultrasonically disperse for 10 min, add 2.8 g of (3-carboxypropyl)trimethylammonium chloride, stir thoroughly for 8 h, filter, wash, and dry to obtain the modified dickite.

[0036] SS2: Place 3 g of modified dickite in 120 ml of anhydrous ethanol, ultrasonically disperse for 12 minutes, then add 3.5 g of mercaptoethylamine, 0.3 g of 4-dimethylaminopyridine and 0.9 g of dicyclohexylcarbodiimide. Heat to 60°C and react for 5 hours. After filtering, washing and drying, the thiolated dickite is obtained.

[0037] Analysis of the nitrogen and sulfur contents in modified diopside and thiolated diopside showed that the nitrogen content in modified diopside was 3.3%, and no sulfur was contained; the nitrogen content in thiolated diopside was 5.6%, and the sulfur content was 7.1%. Compared with modified diopside, the nitrogen content in thiolated diopside was significantly increased and sulfur appeared, which was due to the reaction between the carboxyl group in the modified diopside structure and the amino group in the mercaptoethylamine structure. Example

[0038] Preparation technology of quick-drying corrosion-resistant topcoat

[0039] Step 1: uniformly mix 60 parts of epoxy acrylate resin, 25 parts of anti-corrosion resin, 12 parts of mercapto dickite, 2 parts of dimethyl silicone oil, 3 parts of antioxidant 1010, 2 parts of calcium dodecylbenzenesulfonate, and 1 part of polyethyl acrylate to obtain component A;

[0040] Step 2: Mix 3 parts of benzoin dimethyl ether and 120 parts of deionized water to obtain component B. Example

[0041] Preparation technology of quick-drying corrosion-resistant topcoat

[0042] Step 1: Evenly mix 70 parts of epoxy acrylate resin, 28 parts of anti-corrosion resin, 13 parts of mercapto-dipyridazine, 2.5 parts of fatty alcohol polyoxyethylene ether, 4 parts of antioxidant 2246, 3 parts of sodium lauryl polyoxyethylene ether sulfate, and 2 parts of polybutyl acrylate to obtain component A;

[0043] Step 2: Evenly mix 4 parts of 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one and 135 parts of deionized water to obtain component B. Example

[0044] Preparation technology of quick-drying corrosion-resistant topcoat

[0045] Step 1: Evenly mix 80 parts of epoxy acrylate resin, 30 parts of anti-corrosion resin, 15 parts of mercapto dickite, 3 parts of dimethyl silicone oil, 5 parts of antioxidant 1135, 5 parts of sodium dodecylbenzenesulfonate, and 3 parts of polyethyl acrylate to obtain component A;

[0046] Step 2: Mix 6 parts of benzophenone and 150 parts of deionized water to obtain component B.

[0047] Comparative Example 1

[0048] Preparation process of topcoat

[0049] Step 1: Evenly mix 70 parts of epoxy acrylate resin, 13 parts of mercapto-dipyridazine, 2.5 parts of fatty alcohol polyoxyethylene ether, 4 parts of antioxidant 2246, 3 parts of sodium lauryl polyoxyethylene ether sulfate, and 2 parts of polybutyl acrylate to obtain component A;

[0050] Step 2: Evenly mix 4 parts of 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one and 135 parts of deionized water to obtain component B.

[0051] Comparative Example 2

[0052] Preparation process of topcoat

[0053] Step 1: Evenly mix 70 parts of epoxy acrylate resin, 28 parts of anti-corrosion resin, 2.5 parts of fatty alcohol polyoxyethylene ether, 4 parts of antioxidant 2246, 3 parts of sodium lauryl polyoxyethylene ether sulfate, and 2 parts of polybutyl acrylate to obtain component A;

[0054] Step 2: Evenly mix 4 parts of 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one and 135 parts of deionized water to obtain component B.

[0055] Comparative Example 3

[0056] Preparation process of topcoat

[0057] Step 1: Evenly mix 70 parts of epoxy acrylate resin, 28 parts of modified chloroacetic acid resin, 13 parts of mercapto-dipyridazine, 2.5 parts of fatty alcohol polyoxyethylene ether, 4 parts of antioxidant 2246, 3 parts of sodium lauryl polyoxyethylene ether sulfate, and 2 parts of polybutyl acrylate to obtain component A;

[0058] Step 2: Evenly mix 4 parts of 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one and 135 parts of deionized water to obtain component B.

[0059] Comparative Example 4

[0060] Preparation process of topcoat

[0061] Step 1: Evenly mix 70 parts of epoxy acrylate resin, 28 parts of anti-corrosion resin, 13 parts of modified ground stone, 2.5 parts of fatty alcohol polyoxyethylene ether, 4 parts of antioxidant 2246, 3 parts of sodium lauryl polyoxyethylene ether sulfate, and 2 parts of polybutyl acrylate to obtain component A;

[0062] Step 2: Evenly mix 4 parts of 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one and 135 parts of deionized water to obtain component B.

[0063] Performance testing

[0064] The topcoats prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were used as samples, and component A and component B were mixed and coated on a steel plate that met the specifications. The topcoats were irradiated under ultraviolet light with a wavelength of 395 nm and an energy density of 600 mW / cm2 until the topcoat was cured. The cotton ball blowing method was used to determine whether the curing was complete. The curing time taken when the cotton ball could be blown away and no cotton fibers were left on the film surface was recorded by a stopwatch. Each group was tested 3 times, and the results were averaged to determine the curing rate of the sample. The cured samples were subjected to a wear resistance test in accordance with the reference standard GB / T1768-2006 to determine the wear resistance of the samples. The cured samples were subjected to a salt spray test in accordance with the reference standard GB / T1771-2007 to determine the corrosion resistance of the samples. The specific test results are shown in the table below:

[0065]

[0066] It can be seen from the above table that the samples prepared in Examples 1 to 3 all have excellent wear resistance and corrosion resistance, and at the same time, have a short curing time and quick-drying characteristics. In the sample prepared in Comparative Example 1, no anti-corrosion resin is added, and the corrosion resistance is poor. In the sample prepared in Comparative Example 2, no mercapto-dipstone is added, and the wear resistance is not as good as that of the embodiment and the sample curing time is long. In the sample prepared in Comparative Example 3, modified chloroacetic acid resin and mercapto-dipstone are directly added, and the corrosion resistance needs to be improved. In the sample prepared in Comparative Example 4, modified ipstone and anti-corrosion resin are directly added, and the sample curing time is long and the curing rate is slow.

[0067] 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.

[0068] 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 quick-drying corrosion-resistant topcoat, characterized in that: The invention comprises component A and component B; the component A comprises the following raw materials in parts by weight: 60-80 parts of epoxy acrylate resin, 25-30 parts of anti-corrosion resin, 12-15 parts of mercapto-benzene, 2-3 parts of defoamer, 3-5 parts of antioxidant, 2-5 parts of emulsifier, and 1-3 parts of leveling agent; the component B comprises the following raw materials in parts by weight: 3-6 parts of photoinitiator and 120-150 parts of deionized water; the anti-corrosion resin is prepared by reacting a modified chloroacetic acid resin with 2-amino-5-fluorobenzotrifluoride; the modified chloroacetic acid resin is prepared by reacting a hydroxychloroacetic acid resin with 2-chloroacrylic acid; the mercapto-benzene is prepared by reacting a modified benzene with mercaptoethylamine; and the modified benzene is prepared by intercalating (3-carboxypropyl)trimethylammonium chloride into benzene.

2. A quick-drying corrosion-resistant topcoat according to claim 1, characterized in that: The defoaming agent is any one of dimethyl silicone oil and fatty alcohol polyoxyethylene ether; the antioxidant is any one of antioxidant 1010, antioxidant 2246, and antioxidant 1135; the emulsifier is any one of calcium dodecylbenzenesulfonate, sodium dodecyl polyoxyethylene ether sulfate, alkylphenol polyoxyethylene ether sulfonate, sodium dodecylbenzenesulfonate, and sodium dodecyl sulfate; the leveling agent is any one of polybutyl acrylate and polyethyl acrylate; and the photoinitiator is any one of benzoin dimethyl ether, thioxanthone, benzophenone, and 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one.

3. The quick-drying corrosion-resistant topcoat according to claim 1, characterized in that: The preparation method of the anti-corrosion resin comprises the following steps: S1: placing hydroxychloroacetic acid resin and 2-chloroacrylic acid in toluene, stirring and mixing thoroughly, adding p-toluenesulfonic acid, heating to react, and collecting the product after reduced pressure distillation to obtain a modified chloroacetic acid resin; S2: Place the modified chloroacetic acid resin and 2-amino-5-fluorobenzotrifluoride in N,N-dimethylformamide, add a catalyst, raise the temperature to 55-65°C and react for 6-8 hours, collect the product after reduced pressure distillation, and obtain an anti-corrosion resin.

4. A quick-drying corrosion-resistant topcoat according to claim 3, characterized in that: In step S1, the temperature of the temperature-raising reaction is 90-95° C. and the time is 3-5 hours.

5. The quick-drying corrosion-resistant topcoat according to claim 3, characterized in that: In step S2, the catalyst is potassium carbonate.

6. The quick-drying corrosion-resistant topcoat according to claim 1, characterized in that: The preparation method of the mercaptolated dickite comprises the following steps: SS1: Place dickite in deionized water and ultrasonically disperse for 10-15 minutes. Add (3-carboxypropyl)trimethylammonium chloride and stir thoroughly for 8-10 hours. Filter, wash, and dry to obtain modified dickite. SS2: Place the modified dickite in anhydrous ethanol, ultrasonically disperse it for 12-15 minutes, add mercaptoethylamine and a composite catalyst, heat to 60-65°C and react for 5-6 hours, filter, wash and dry to obtain the thiolated dickite.

7. The quick-drying corrosion-resistant topcoat according to claim 6, characterized in that: In step SS2, the composite catalyst is 4-dimethylaminopyridine and dicyclohexylcarbodiimide in a ratio of 0.3-1:0.9-3.

8. A process for preparing the quick-drying corrosion-resistant topcoat according to claim 1, characterized in that: The following steps are involved: Step 1: Evenly mix epoxy acrylate resin, anti-corrosion resin, mercapto-dimethylbenzene, defoamer, antioxidant, emulsifier, and leveling agent to obtain component A; Step 2: Evenly mix the photoinitiator and deionized water to obtain component B.

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