A wear-resistant and stain-resistant UV coating and its preparation method

Abstract

The present invention relates to a wear-resistant and stain-resistant UV coating and a preparation method thereof, belonging to the technical field of UV coatings. The UV coating comprises, by weight: 100 parts of acrylate resin, 18-26 parts of modified anti-wear filler, 20-25 parts of reactive diluent, 3-3.5 parts of photoinitiator, 5-7 parts of color paste, 0.8-1 part of substrate wetting agent, 1-1.2 parts of leveling agent and 0.5-0.7 part of defoaming agent; the modified anti-wear filler is prepared by carrying out amine-ester exchange between methyl trifluoroacetate and diethylenetriamine to form an amide compound capped with a fluorine structure, i.e., a fluorinated modifier, and then using corundum powder as a carrier, and loading it onto the surface of corundum powder particles by means of the chelating property of the multi-nitrogen structure in the fluorinated modifier molecule. The organic amine in its structure provides an alkaline environment on the surface of corundum powder, and in-situ promotes the coupling of silane coupling agent KH-570 on corundum powder, and the surface of corundum powder is compound-modified; the introduction of the modified anti-wear filler endows the coating with good wear resistance and stain resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and specifically relates to a wear-resistant and stain-resistant UV coating and a preparation method thereof. Background Art

[0002] As an indispensable material in the industrial and civil fields, coatings play a key role in multiple industries. Especially in industries such as construction, transportation, automotive, and electronics, its excellent protective performance and decorative functions make it an indispensable material; among them, UV coatings have attracted wide attention due to their characteristics such as low curing temperature, low volatile content, and fast curing speed.

[0003] However, the existing UV coatings have deficiencies in wear resistance and resistance to pollutants. Especially in industrial equipment, outdoor buildings, and scenarios with high-intensity cleaning requirements, they are difficult to meet the needs. Summary of the Invention

[0004] In order to solve the technical problems mentioned in the background art, the purpose of the present invention is to provide a wear-resistant and stain-resistant UV coating and a preparation method thereof.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A wear-resistant and stain-resistant UV coating, comprising by weight: 100 parts of acrylate resin, 18 - 26 parts of modified anti-wear filler, 20 - 25 parts of reactive diluent, 3 - 3.5 parts of photoinitiator, 5 - 7 parts of color paste, 0.8 - 1 part of substrate wetting agent, 1 - 1.2 parts of leveling agent, and 0.5 - 0.7 parts of defoaming agent.

[0007] The modified anti-wear filler is prepared by the following method:

[0008] Step A1: Premix diethylenetriamine, methyl trifluoroacetate, and anhydrous tetrahydrofuran, pre-heat to 35 - 40 °C, apply stirring at 60 - 90 rpm, slowly add triethylamine and react for 4 - 5 h, then pressurize to 5 - 8 bar with nitrogen, continue to heat to 75 - 90 °C and reflux for 2.5 - 4 h. After the reaction, rotary evaporation is used to remove tetrahydrofuran to obtain a fluorinated modifier;

[0009] Furthermore, the feeding ratio of diethylenetriamine, methyl trifluoroacetate, triethylamine, and anhydrous tetrahydrofuran is 0.1 mol: 0.22 - 0.25 mol: 8 - 14 mL: 50 - 70 mL. Triethylamine is used as a basic catalyst to promote the amine-ester exchange between methyl trifluoroacetate and diethylenetriamine.

[0010] Step A2: Mix the silane coupling agent KH-570 with an acidic ethanol aqueous solution, stir at 120 - 150 rpm for hydrolysis at room temperature for 30 - 50 min to obtain a hydrolysis solution. Premix corundum powder, fluorinated modifier, and acetone and heat up to 40 - 50 °C, add the hydrolysis solution and disperse it by ultrasonic wave, let it stand for 24 h, take the bottom precipitate, wash it with water and dry it to obtain the modified anti-wear filler;

[0011] Further, the feeding ratio of corundum powder, fluorinated modifier, silane coupling agent KH-570, acidic ethanol aqueous solution, and acetone is 50 g : 0.9 - 1.3 g : 1.5 - 2 g : 30 - 40 mL : 60 - 80 mL. The poly-nitrogen structure in the fluorinated modifier has a chelating effect and is preferentially loaded onto the surface of corundum powder particles. The silane coupling agent KH-570 hydrolyzes into silanol in an acidic alcohol water environment. The organic amine in the fluorinated modifier provides a basic environment on the surface of corundum powder, in-situ promoting the coupling of silanol with corundum powder and grafting methacryloyloxy modification onto the surface of corundum powder.

[0012] Preferably, the pH value of the acidic ethanol solution is 2 - 3, and the volume fraction of ethanol is 40 - 55%. Under this condition, the silane coupling agent KH-570 is easy to hydrolyze fully and maintain a stable hydrolysis state, and is easy to be in-situ loaded onto the surface of corundum powder.

[0013] Preferably, the fineness of the corundum powder is 600 - 1000 mesh. At this particle size, it is easy to disperse, ensuring the fineness of the coating and providing good loadability at the same time.

[0014] Preferably, the acrylate resin is selected from polyurethane acrylate resin, which has good adhesion properties with most substrates, good wear resistance and weather resistance, and high applicability.

[0015] Preferably, the reactive diluent is composed of dipropylene glycol diacrylate and trimethylolpropane triacrylate in combination, ensuring good dilution effect, obtaining good crosslinking degree at the same time, and maintaining excellent toughness of the coating.

[0016] A preparation method of a wear-resistant and stain-resistant UV coating, specifically: Mix and dilute the acrylate resin and the reactive diluent, then add color paste, substrate wetting agent, leveling agent, and defoaming agent and mix them, and finally add the modified anti-wear filler and photoinitiator and grind and disperse them to obtain the UV coating.

[0017] The beneficial effects of the present invention:

[0018] The present invention adds a self-developed modified anti-wear filler to the existing UV coating system, endowing the coating with good wear resistance and stain resistance. The modified anti-wear filler is prepared by amine-ester exchange of methyl trifluoroacetate and diethylenetriamine to form an amide compound capped with a fluorine structure, namely a fluorinated modifier. Then, using corundum powder as a carrier, the fluorinated modifier is loaded onto the surface of corundum powder particles by utilizing the chelating property of the poly-nitrogen structure in the fluorinated modifier molecule. The organic amine in its structure provides an alkaline environment on the surface of corundum powder, in-situ promoting the coupling of silane coupling agent KH-570 on corundum powder and performing composite modification on the surface of corundum powder. Compared with the existing compound coatings, it has the following advantages:

[0019] 1. In the coating composite system, the fluorinated modifier introduces a double-hydrophobic fluoride into the coating. Taking corundum powder as a carrier, it is not easy to segregate in the coating, endowing the coating with uniform stain resistance and having a low impact on the adhesion and mechanical properties of the coating;

[0020] 2. In the cured coating of the coating, the surface of corundum powder is grafted with methacryloxy by silane coupling agent KH-570, which co-crosslinks with acrylate resin under photocuring, greatly improving the bonding strength between corundum powder and resin and being not easy to fall off during the friction and wear process, thereby fully exerting the wear-resistant effect;

[0021] The fluorinated modifier is filled in the crosslinking layer of corundum powder and resin. Its fluorine structure can reduce the interfacial tension of the resin, enabling the stress generated during shrinkage in the crosslinking process to be released. In addition, the fluorine structure can increase the mobility of the polymer chain, enabling the coating to deform better and not crack easily when subjected to external forces, making the protective performance of the coating more stable. Specific embodiments

[0022] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0023] Example 1, preparation of wear-resistant and stain-resistant UV coating, the specific implementation process is as follows:

[0024] (1) Preparation of modified anti-wear filler

[0025] Step A1: Premix diethylenetriamine, methyl trifluoroacetate, and anhydrous tetrahydrofuran, preheat to 35°C, apply stirring at 60 rpm, slowly add triethylamine, and react for 5 hours. Then, increase the pressure to 5 bar with nitrogen, continue to heat to 75°C, and reflux for 4 hours. The feed ratio of diethylenetriamine, methyl trifluoroacetate, triethylamine, and anhydrous tetrahydrofuran is 0.1 mol: 0.22 mol: 8 mL: 50 mL. After the reaction, remove tetrahydrofuran by rotary evaporation to obtain a fluorinated modifier.

[0026] Step A2: Prepare a 40% mass fraction of ethanol aqueous solution and adjust the pH value to 3 with formic acid, take a silane coupling agent KH-570 and an acidic ethanol aqueous solution, mix them, apply stirring at 120 rpm for hydrolysis at room temperature for 30 minutes to obtain a hydrolyzate, premix the corundum powder, fluorination modifier and acetone and heat them to 40°C, add the hydrolyzate and ultrasonically disperse, wherein the feed ratio of corundum powder, fluorination modifier, silane coupling agent KH-570, acidic ethanol aqueous solution and acetone is 50g:1.3g:1.5g:30mL:80mL, and the corundum powder is selected from 600 mesh micropowder. After standing for 24 hours, the bottom precipitate is washed with water and dried to obtain a modified anti-wear filler.

[0027] (2) Preparation of UV coating

[0028] The raw materials are measured in parts by weight: 100 parts of acrylate resin, and U-Cure 9303 polyurethane acrylate resin is used in the implementation process; 18 parts of modified anti-wear filler, which is homemade in this embodiment; 20 parts of active diluent, and dipropylene glycol diacrylate and trimethylolpropane triacrylate are compounded in a mass ratio of 2:1 in the implementation process; 3 parts of photoinitiator, and photoinitiator 1173 is used in the implementation process; 5 parts of color paste, and commercially available oily black paste is used in the implementation process; 0.8 parts of base wetting agent, and HY-6086 type raw material is used in the implementation process; 1 part of leveling agent, and HY-6410 type raw material is used in the implementation process; 0.5 parts of defoaming agent, and HY-1040F type raw material is used in the implementation process.

[0029] Add the acrylic resin and active diluent into the mixer, stir at a low speed of 30 rpm to dilute, then add the color paste, base wetting agent, leveling agent and defoaming agent and mix evenly, finally add the modified anti-wear filler and photoinitiator and grind and disperse to obtain the UV coating.

[0030] Example 2, preparation of wear-resistant and anti-fouling UV coating, the specific implementation process is as follows:

[0031] (1) Preparation of modified anti-wear filler

[0032] Step A1: Premix diethylenetriamine, methyl trifluoroacetate, and anhydrous tetrahydrofuran, preheat to 40°C, apply stirring at 90 rpm, slowly add triethylamine, and react for 4 hours. Then, increase the pressure to 8 bar with nitrogen, continue to heat to 90°C, and reflux for 2.5 hours. The feed ratio of diethylenetriamine, methyl trifluoroacetate, triethylamine, and anhydrous tetrahydrofuran is 0.1 mol: 0.25 mol: 14 mL: 70 mL. After the reaction, remove tetrahydrofuran by rotary evaporation to obtain a fluorinated modifier.

[0033] Step A2: Prepare a 55% mass fraction of ethanol aqueous solution and adjust the pH value to 2 with formic acid, take a silane coupling agent KH-570 and an acidic ethanol aqueous solution, mix them, apply stirring at 150 rpm for hydrolysis at room temperature for 50 minutes to obtain a hydrolyzate, premix the corundum powder, fluorinated modifier and acetone and heat them to 50°C, add the hydrolyzate and ultrasonically disperse, wherein the feed ratio of corundum powder, fluorinated modifier, silane coupling agent KH-570, acidic ethanol aqueous solution and acetone is 50g:0.9g:2g:40mL:60mL, and the corundum powder is selected from 1000 mesh micropowder. After standing for 24 hours, the bottom precipitate is washed with water and dried to obtain a modified anti-wear filler.

[0034] (2) Preparation of UV coating

[0035] The raw materials are measured in parts by weight: 100 parts of acrylate resin, and U-Cure 9303 polyurethane acrylate resin is used in the implementation process; 26 parts of modified anti-wear filler, which is homemade in this embodiment; 25 parts of active diluent, which is compounded by dipropylene glycol diacrylate and trimethylolpropane triacrylate in a mass ratio of 2:1 in the implementation process; 3.5 parts of photoinitiator, and photoinitiator 1173 is used in the implementation process; 7 parts of color paste, and a commercially available oily black paste is used in the implementation process; 1 part of base wetting agent, and HY-6086 type raw material is used in the implementation process; 1.2 parts of leveling agent, and HY-6410 type raw material is used in the implementation process; 0.7 parts of defoaming agent, and HY-1040F type raw material is used in the implementation process.

[0036] Add the acrylic resin and active diluent into the mixer, stir at a low speed of 30 rpm to dilute, then add the color paste, base wetting agent, leveling agent and defoaming agent and mix evenly, finally add the modified anti-wear filler and photoinitiator and grind and disperse to obtain the UV coating.

[0037] Example 3, preparation of wear-resistant and anti-fouling UV coating, the specific implementation process is as follows:

[0038] (1) Preparation of modified anti-wear filler

[0039] Step A1: Premix diethylenetriamine, methyl trifluoroacetate, and anhydrous tetrahydrofuran, preheat to 35°C, apply stirring at 60 rpm, slowly add triethylamine, and react for 5 hours. Then, increase the pressure to 6 bar with nitrogen, continue to heat to 80°C, and reflux for 3 hours. The feed ratio of diethylenetriamine, methyl trifluoroacetate, triethylamine, and anhydrous tetrahydrofuran is 0.1 mol: 0.23 mol: 10 mL: 60 mL. After the reaction, remove tetrahydrofuran by rotary evaporation to obtain a fluorinated modifier.

[0040] Step A2: Prepare a 50% mass fraction of ethanol aqueous solution and adjust the pH value to 3 with formic acid, take a silane coupling agent KH-570 and an acidic ethanol aqueous solution, mix them, apply stirring at 150 rpm for hydrolysis at room temperature for 40 minutes to obtain a hydrolyzate, premix the corundum powder, fluorination modifier and acetone and heat them to 45°C, add the hydrolyzate and ultrasonically disperse, wherein the feed ratio of corundum powder, fluorination modifier, silane coupling agent KH-570, acidic ethanol aqueous solution and acetone is 50g:1.1g:1.7g:35mL:70mL, and the corundum powder is selected from 800 mesh micropowder. After standing for 24 hours, the bottom precipitate is washed with water and dried to obtain a modified anti-wear filler.

[0041] (2) Preparation of UV coating

[0042] The raw materials are measured in parts by weight: 100 parts of acrylate resin, and U-Cure 9303 polyurethane acrylate resin is used in the implementation process; 20 parts of modified anti-wear filler, which is homemade in this embodiment; 22 parts of active diluent, and dipropylene glycol diacrylate and trimethylolpropane triacrylate are compounded in a mass ratio of 2:1 in the implementation process; 3.2 parts of photoinitiator, and photoinitiator 1173 is used in the implementation process; 6 parts of color paste, and commercially available oily black paste is used in the implementation process; 0.9 parts of base wetting agent, and HY-6086 type raw material is used in the implementation process; 1.1 parts of leveling agent, and HY-6410 type raw material is used in the implementation process; 0.6 parts of defoaming agent, and HY-1040F type raw material is used in the implementation process.

[0043] Add the acrylic resin and active diluent into the mixer, stir at a low speed of 30 rpm to dilute, then add the color paste, base wetting agent, leveling agent and defoaming agent and mix evenly, finally add the modified anti-wear filler and photoinitiator and grind and disperse to obtain the UV coating.

[0044] Example 4, preparation of wear-resistant and anti-fouling UV coating, the specific implementation process is as follows:

[0045] (1) Preparation of modified anti-wear filler

[0046] Step A1: Premix diethylenetriamine, methyl trifluoroacetate, and anhydrous tetrahydrofuran, preheat to 40°C, apply stirring at 90 rpm, slowly add triethylamine, and react for 5 hours. Then, increase the pressure to 7 bar with nitrogen, continue to heat to 85°C, and reflux for 3 hours. The feed ratio of diethylenetriamine, methyl trifluoroacetate, triethylamine, and anhydrous tetrahydrofuran is 0.1 mol: 0.22 mol: 12 mL: 70 mL. After the reaction, remove tetrahydrofuran by rotary evaporation to obtain a fluorinated modifier.

[0047] Step A2: Prepare a 45% mass fraction of ethanol aqueous solution and adjust the pH value to 2 with formic acid, take a silane coupling agent KH-570 and an acidic ethanol aqueous solution, mix them, apply stirring at 150 rpm for hydrolysis at room temperature for 40 minutes to obtain a hydrolyzate, premix the corundum powder, fluorinated modifier and acetone and heat them to 45°C, add the hydrolyzate and ultrasonically disperse, wherein the feed ratio of corundum powder, fluorinated modifier, silane coupling agent KH-570, acidic ethanol aqueous solution and acetone is 50g:1.2g:1.6g:40mL:70mL, and the corundum powder is selected from 800 mesh micropowder. After standing for 24 hours, the bottom precipitate is washed with water and dried to obtain a modified anti-wear filler.

[0048] (2) Preparation of UV coating

[0049] The raw materials are measured in parts by weight: 100 parts of acrylate resin, and U-Cure 9303 polyurethane acrylate resin is used in the implementation process; 22 parts of modified anti-wear filler, which is homemade in this embodiment; 23 parts of active diluent, and dipropylene glycol diacrylate and trimethylolpropane triacrylate are compounded in a mass ratio of 2:1 in the implementation process; 3.2 parts of photoinitiator, and photoinitiator 1173 is used in the implementation process; 6 parts of color paste, and commercially available oily black paste is used in the implementation process; 0.9 parts of base wetting agent, and HY-6086 type raw material is used in the implementation process; 1 part of leveling agent, and HY-6410 type raw material is used in the implementation process; 0.5 parts of defoaming agent, and HY-1040F type raw material is used in the implementation process.

[0050] Add the acrylic resin and active diluent into the mixer, stir at a low speed of 30 rpm to dilute, then add the color paste, base wetting agent, leveling agent and defoaming agent and mix evenly, finally add the modified anti-wear filler and photoinitiator and grind and disperse to obtain the UV coating.

[0051] Comparative Example 1: Referring to Example 4, the modified anti-wear filler was replaced with the same weight portion of KH-570-coupled corundum powder, and the rest of the implementation process was exactly the same. Among them, the preparation method of KH-570-coupled corundum powder was as follows: Mix the silane coupling agent KH-570 and an ethanol aqueous solution, adjust the pH value to 3.5 with formic acid, stir and hydrolyze at room temperature for 1 h, then add 800-mesh corundum powder for ultrasonic dispersion, stand for 24 h, take the bottom sediment for washing with water and drying. During the implementation process, the feeding ratio of corundum powder, silane coupling agent KH-570 and ethanol aqueous solution was 50 g: 2.5 g: 100 mL, and the volume fraction of the ethanol aqueous solution was 50%.

[0052] Comparative Example 2: This comparative example was based on Comparative Example 1, and 0.4 part of 2-perfluorooctyl ethyl acrylate was added to the raw material formula and added together with the KH-570-coupled corundum powder, and the rest of the implementation process was exactly the same.

[0053] Take the phosphatized low-carbon steel sheet as the substrate, and apply the UV coating prepared above to the surface of the substrate with a coater, and apply ultraviolet light irradiation with an intensity of 220 W / m 2 for curing for 5 min, stand for 24 h, and conduct the following tests on the coating performance:

[0054] Refer to the standard of GB / T 13452.2-2008 to detect the curing thickness of the coating; refer to the standard of GB / T 9286-2021 to detect the adhesion of the coating; refer to the standard of GB / T 1768-2006 to detect the abrasion resistance of the coating, the rotation speed was 60 rpm, the load was 1000 g, and the number of running times was 500 times; refer to the standard of GB / T 30791-2014 for T-bend test; refer to the standard of ASTM D7490-13 to detect the surface water contact angle of the coating; the specific test results are shown in Table 1:

[0055] Table 1

[0056]

[0057] It can be seen from the test results in Table 1 that the coating prepared in the example has excellent abrasion resistance after curing, the T-bend test reaches 0T, the coating has excellent toughness, is not easy to crack and fall off during deformation, and at the same time has a high water contact angle and good anti-fouling performance.

[0058] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions 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 a suitable manner in any one or more embodiments or examples.

[0059] The above content is only an example and explanation of the present invention. Those skilled in the art of the present technology can make various modifications, supplements or use similar methods for substitution to the described specific embodiments. As long as they do not deviate from the invention or exceed the scope defined by this claims, they should fall within the protection scope of the present invention.

Claims

1. A wear-resistant and stain-resistant UV coating, characterized in that, It includes, by weight parts: 100 parts of acrylate resin, 18 - 26 parts of modified anti-wear filler, 20 - 25 parts of reactive diluent, 3 - 3.5 parts of photoinitiator, 5 - 7 parts of color paste, 0.8 - 1 part of substrate wetting agent, 1 - 1.2 parts of leveling agent, and 0.5 - 0.7 part of defoamer; The modified anti-wear filler is prepared by the following method: Step A1: Premix diethylenetriamine, methyl trifluoroacetate, and anhydrous tetrahydrofuran, pre-heat to 35 - 40 °C, stir and slowly add triethylamine to react for 4 - 5 h. Then pressurize with nitrogen to 5 - 8 bar, continue to heat to 75 - 90 °C for reflux reaction for 2.5 - 4 h. After the reaction, rotary evaporate to remove tetrahydrofuran to obtain a fluorinated modifier; Step A2: Mix silane coupling agent KH-570 and acidic ethanol aqueous solution, stir and hydrolyze at room temperature for 30 - 50 min to obtain a hydrolyzate. Premix corundum powder, fluorinated modifier, and acetone and heat to 40 - 50 °C, add the hydrolyzate and disperse by ultrasonic, stand for 24 h, take the bottom precipitate, wash with water and dry to obtain the modified anti-wear filler.

2. The wear-resistant and stain-resistant UV coating according to claim 1, characterized in that, The feeding ratio of diethylenetriamine, methyl trifluoroacetate, triethylamine, and anhydrous tetrahydrofuran is 0.1 mol: 0.22 - 0.25 mol: 8 - 14 mL: 50 - 70 mL.

3. An abrasion-resistant and stain-resistant UV coating according to claim 2, wherein, The feeding ratio of corundum powder, fluorinated modifier, silane coupling agent KH-570, acidic ethanol aqueous solution, and acetone is 50 g: 0.9 - 1.3 g: 1.5 - 2 g: 30 - 40 mL: 60 - 80 mL.

4. The wear-resistant and stain-resistant UV coating according to claim 3, wherein The pH value of the acidic ethanol solution is 2 - 3, and the volume fraction of ethanol is 40 - 55%.

5. The wear-resistant and stain-resistant UV coating according to claim 3, wherein, The fineness of the corundum powder is 600 - 1000 mesh.

6. The wear-resistant and stain-resistant UV coating according to claim 1, wherein The acrylate resin is selected from polyurethane acrylate resin.

7. An abrasion-resistant and stain-resistant UV coating according to claim 1, wherein, The reactive diluent is composed of dipropylene glycol diacrylate and trimethylolpropane triacrylate.

8. A preparation method of the wear-resistant and stain-resistant UV coating according to any one of claims 1-7, characterized in that, Specifically: Mix and dilute the acrylate resin and the reactive diluent, then add the color paste, substrate wetting agent, leveling agent, and defoamer and mix. Finally, add the modified anti-wear filler and photoinitiator and grind and disperse to obtain the UV coating.

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