Wear-resistant uv-cured coating and method for its production

Abstract

The present application relates to the technical field of UV coating, and discloses a wear-resistant UV curing coating and a preparation method thereof.The UV curing coating prepared by the present application comprises the following raw materials in parts by weight: 45-65 parts of acrylic resin, 15-25 parts of acrylate modified polyurethane, 8-15 parts of a modifier, 6-10 parts of a wear-resistant agent, 3.5-5.5 parts of a photoinitiator, 3-6 parts of isopropyl alcohol, 0.5-1 part of a defoaming agent, 0.1-0.5 parts of a leveling agent, and 20-30 parts of water; the coating is prepared by using acrylic resin and acrylate modified polyurethane as main raw materials and adding functional additives such as a modifier, isopropyl alcohol and a wear-resistant agent; the coating film after curing has excellent wear resistance, corrosion resistance and adhesion, and has a wide application prospect in the fields of building facilities and industrial equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of UV coating, in particular to a wear-resistant UV curing coating and a preparation method thereof. BACKGROUND

[0002] Ultraviolet (UV) curing coating is an environmentally friendly coating. It can produce active free radicals or cations by UV light to initiate photoinitiator, so as to promote the polymerization reaction of unsaturated double bonds in the resin system and quickly form a cross-linked and cured coating. Compared with traditional thermal curing coating, UV curing coating has the characteristics of fast curing speed (seconds), low energy consumption, low VOC emission, excellent coating performance, etc., and is widely used in the fields of electronics, automobiles, metal protection, etc.

[0003] However, the conventional UV curing coating still has deficiencies in corrosion resistance, wear resistance, adhesion, etc. The adhesion and wear resistance of the cured coating film are low, which can cause the coating film to fall off or wear out, allowing the coating film to be penetrated by corrosive media, thereby causing the overall corrosion resistance of the coating film to deteriorate, and ultimately leading to the decline of the overall performance of the substrate. In particular, the comprehensive performance under harsh environments (such as marine climate, chemical corrosion, mechanical wear, etc.) still needs to be improved. Therefore, in recent years, researchers have been committed to developing a UV curing coating with excellent corrosion resistance, wear resistance and adhesion to meet the actual application requirements. SUMMARY

[0004] In order to solve the above technical problems, the present application provides a wear-resistant UV curing coating and a preparation method thereof.

[0005] The object of the present application can be achieved by the following technical solutions:

[0006] A wear-resistant UV curing coating, comprising the following raw materials by weight: 45-65 parts of acrylic resin, 15-25 parts of acrylate modified polyurethane, 8-15 parts of modifier, 6-10 parts of wear-resistant agent, 3.5-5.5 parts of photoinitiator, 3-6 parts of isopropyl alcohol, 0.5-1 part of defoaming agent, 0.1-0.5 part of leveling agent, and 20-30 parts of water.

[0007] Further, the wear-resistant agent is a mixture of ceramic micro powder and nano molybdenum disulfide, and the mass ratio of ceramic micro powder to nano molybdenum disulfide is 1:2.

[0008] Further, the photoinitiator is one of 2-hydroxy-2-methylphenylpropanone, benzophenone and photoinitiator TPO.

[0009] Further, the defoaming agent is one of BYK-024 defoaming agent or BYK-052N defoaming agent.

[0010] Further, the flow agent is one of BYK-333 flow agent or BYK-354 flow agent;

[0011] The modifier is prepared by the following steps:

[0012] Step A1, 5-amino-2-nitro-trifluorotoluene is stirred uniformly in ethanol, dibutyltin dilaurate is added and stirred for 10 min, allyl isothiocyanate is added, and the temperature is raised to 50℃ for 3.5-4.5h, Pd / C and hydrazine hydrate are added, and the temperature is raised to 80℃ for refluxing for 5-6h, filtration, water is added to precipitate the product, drying, recrystallization, and the thiourea derivative is obtained;

[0013] Further, in step A1, the amount ratio of 5-amino-2-nitro-trifluorotoluene, ethanol, dibutyltin dilaurate, allyl isothiocyanate, Pd / C, hydrazine hydrate and water is 0.01-0.03mol:100mL:0.0005-0.002g:0.01-0.03mol:0.1-0.3g:1.1-3.3g:100mL;

[0014] Step A2, the thiourea derivative and 1-benzothiophen-2-carboxaldehyde are added to toluene, stirred uniformly under nitrogen condition, and the temperature is raised to 110℃, condensation refluxing is carried out for 4.5-5.5h, the temperature is cooled to room temperature, poured into benzene and left for 5-10min, filtration, washing, drying, the product is collected and placed in sodium borohydride solution, reaction is carried out under ice water bath and nitrogen condition for 8-12h, filtration, washing, drying, and the benzothiophen-thiourea derivative is obtained;

[0015] Further, in step A2, the amount ratio of the thiourea derivative, 1-benzothiophen-2-carboxaldehyde, toluene, benzene and sodium borohydride solution is 0.01-0.03mol:0.01-0.03mol:100mL:100mL:15-30mL;

[0016] Further, the concentration of the sodium borohydride solution in step A2 is 0.5-2wt%;

[0017] Step A3, 1,4-dichlorobutane, DMF (N,N-dimethylformamide) and triethylamine are mixed and stirred uniformly under nitrogen condition, and then the benzothiophen-thiourea derivative is added, the temperature is raised to 80-90℃ for refluxing for 3.5-4.5h, rotary evaporation, column chromatography purification, drying, and the chlorobenzothiophen-thiourea derivative is obtained;

[0018] Further, in step A3, the amount ratio of 1,4-dichlorobutane, DMF, triethylamine and benzothiophen-thiourea derivative is 0.6-1.8g:100mL:1.1-3.3mL:2.2-6.6g;

[0019] Step A4, under the condition of nitrogen, the chlorobenzothiol-thiourea derivative, DMF, triethylamine are mixed and stirred uniformly, then dopamine hydrochloride is added, and the temperature is increased to 80 DEG C and refluxed for 4h, rotary evaporation, column purification, drying, to obtain the modifier;

[0020] Further, in step A4, the amount ratio of chlorobenzothiol-thiourea derivative, DMF, triethylamine and dopamine hydrochloride is 2.5-7.5g:100mL:1.3-3.9mL:3.2-9.6g.

[0021] A preparation method of the abrasion-resistant UV curing coating comprises the following steps:

[0022] The raw materials are weighed by weight parts, the acrylic resin, the acrylic ester modified polyurethane, the modifier, the isopropyl alcohol and the water are mixed, then stirred at a speed of 400-600rpm for 5-8min, then the abrasion-resistant agent, the defoaming agent and the leveling agent are added and stirred at a speed of 500-700rpm for 3-6min, finally the photoinitiator is added and stirred at a speed of 1000-1200rpm for 30-50min, to obtain the abrasion-resistant UV curing coating.

[0023] The abrasion-resistant UV curing coating has the advantages that:

[0024] The UV curing coating prepared by the method has the advantages that: the acrylic resin and the acrylic ester modified polyurethane are used as main raw materials, and the modifier, the isopropyl alcohol and the abrasion-resistant agent are added as functional additives; the coating film after curing has excellent abrasion resistance, corrosion resistance and adhesion, and has wide application prospects in the fields of building facilities and industrial equipment.

[0025] The UV curing coating in the application introduces the modifier and the abrasion-resistant agent, the introduction of the abrasion-resistant agent further improves the abrasion resistance of the original acrylic coating, so that the coating can adapt to the application environment with higher abrasion resistance requirement; the introduction of the modifier further improves the corrosion resistance and adhesion of the coating film after curing.

[0026] The synergistic effect among the thiourea structure, fluorine element, thiophene structure and o-diphenol structure introduced in the modifier improves the corrosion resistance and adhesion of the substrate; the thiourea structure can form a chemical bond with metal ions (such as copper) on the metal surface to form a stable complex, thereby enhancing the corrosion resistance of the metal surface and the adhesion between the coating and the substrate, which helps to form stronger adhesion on the surface of the coating and improves the adhesion and durability of the coating; the introduction of fluorine element can form a carbon-fluorine bond with carbon atom, which has high hydrophobicity and oleophobicity, can isolate water, oxygen and corrosive medium, and effectively prevents the coating film from being corroded and damaged; when the thiophene structure in the coating contacts the metal surface, a chemical bond is formed between the sulfur atom in the thiophene molecule and the metal atom, which can make the thiophene molecule adhere to the metal surface tightly and form a dense passivation film to effectively isolate the metal from the external environment, thereby preventing the metal surface from being corroded; the ortho-phenolic hydroxyl group of the o-diphenol structure can form a hydrogen bond or a metal chelate bond with the substrate (such as metal), thereby significantly improving the adhesion. In addition, the o-diphenol structure in the modifier can also use the adsorption property of the phenolic hydroxyl group to adsorb the inorganic powder in the wear-resistant agent, so that the modifier can act as a "medium" connecting the inorganic powder and the cured resin, and improve the dispersibility and compatibility of the inorganic powder in the coating. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0028] Embodiment 1: The modifier is prepared by the following steps:

[0029] Step A1, 0.01 mol 5-amino-2-nitrobenzotrifluoride is uniformly stirred in 100 mL ethanol, 0.0005 g of dibutyltin dilaurate is added and stirred for 10 min, 0.01 mol of allyl isothiocyanate is added, and the temperature is raised to 50℃ for 3.5 h, then 0.1 g of Pd / C and 1.1 g of hydrazine hydrate are added, and the temperature is raised to 80℃ for reflux reaction for 5 h, then filtration, addition of 100 mL water to precipitate the product, drying, recrystallization, and the thiourea derivative is obtained;

[0030] Step A2, 0.01 mol of the thiourea derivative and 0.01 mol of 1-benzothiophen-2- carboxaldehyde were added into 100 mL of toluene, mixed and stirred uniformly under the condition of nitrogen, and heated to 110°C, and condensed to reflux for 4.5 h. After being cooled to room temperature, it was poured into 100 mL of benzene and left to stand for 5 min. After being filtered, washed and dried, the product was collected and placed in 30 mL of sodium borohydride solution. After being reacted for 8 h under the condition of ice water bath and nitrogen, it was filtered, washed and dried to obtain the benzothiophen-thiourea derivative, wherein the concentration of the sodium borohydride solution was 0.5 wt%;

[0031] Step A3, 0.6 g of 1,4-dichlorobutane, 100 mL of DMF and 1.1 mL of triethylamine were mixed and stirred uniformly under the condition of nitrogen. Then, 2.2 g of the benzothiophen-thiourea derivative was added, heated to 80°C and refluxed for 3.5 h. After being rotary evaporated, column chromatography was used for purification and drying to obtain the chlorobenzothiophen-thiourea derivative.

[0032] Step A4, 2.5 g of the chlorobenzothiophen-thiourea derivative, 100 mL of DMF and 1.3 mL of triethylamine were mixed and stirred uniformly under the condition of nitrogen. Then, 3.2 g of dopamine hydrochloride was added, heated to 80°C and refluxed for 4 h. After being rotary evaporated, column chromatography was used for purification and drying to obtain the modifier.

[0033] Example 2: The modifier was prepared by the following steps:

[0034] Step A1, 0.02 mol of 5-amino-2-nitrotoluene was stirred uniformly in 100 mL of ethanol. Then, 0.001 g of dibutyltin dilaurate was added and stirred for 10 min. Then, 0.02 mol of allyl isothiocyanate was added and heated to 50°C for reaction for 4 h. Then, 0.2 g of Pd / C and 2.2 g of hydrazine hydrate were added and heated to 80°C for reflux reaction for 5.5 h. After being filtered, 100 mL of water was added to precipitate the product, which was dried and recrystallized to obtain the thiourea derivative.

[0035] Step A2, 0.02 mol of the thiourea derivative and 0.02 mol of 1-benzothiophen-2- carboxaldehyde were added into 100 mL of toluene, mixed and stirred uniformly under the condition of nitrogen, and heated to 110°C, and condensed to reflux for 5 h. After being cooled to room temperature, it was poured into 100 mL of benzene and left to stand for 7.5 min. After being filtered, washed and dried, the product was collected and placed in 25 mL of sodium borohydride solution. After being reacted for 10 h under the condition of ice water bath and nitrogen, it was filtered, washed and dried to obtain the benzothiophen-thiourea derivative, wherein the concentration of the sodium borohydride solution was 1 wt%;

[0036] Step A3, under the condition of nitrogen, 1.2g 1,4-dichlorobutane, 100mL DMF and 2.2mL triethylamine are mixed and stirred uniformly, then 4.4g chlorobenzothiol-thiourea derivative is added, and the temperature is raised to 85℃ to reflux for 4h, then it is rotary evaporated, purified by column chromatography and dried to obtain the chlorobenzothiol-thiourea derivative;

[0037] Step A4, under the condition of nitrogen, 5g chlorobenzothiol-thiourea derivative, 100mL DMF and 2.6mL triethylamine are mixed and stirred uniformly, then 6.4g dopamine hydrochloride is added, and the temperature is raised to 80℃ to reflux for 4h, then it is rotary evaporated, purified by column chromatography and dried to obtain the modifier.

[0038] Example 3: The modifier is prepared by the following steps:

[0039] Step A1, 0.03mol 5-amino-2-nitrotoluene is stirred uniformly in 100mL ethanol, 0.002g dibutyltin dilaurate is added and stirred for 10min, then 0.03mol allyl isothiocyanate is added, and the temperature is raised to 50℃ to react for 4.5h, then 0.3g Pd / C and 3.3g hydrazine hydrate are added, and the temperature is raised to 80℃ to reflux for 6h, then it is filtered, 100mL water is added to precipitate the product, dried and recrystallized to obtain the thiourea derivative;

[0040] Step A2, 0.03mol thiourea derivative and 0.03mol 1-benzothiol-2-carboxaldehyde are added to 100mL toluene, mixed and stirred uniformly under the condition of nitrogen, and the temperature is raised to 110℃ to condense and reflux for 5.5h, then it is cooled to room temperature, poured into 100mL benzene and left to stand for 10min, then it is filtered, washed and dried, the product is collected and placed in 15mL sodium borohydride solution, and the reaction is carried out under the condition of ice water bath and nitrogen for 12h, then it is filtered, washed and dried to obtain the benzothiol-thiourea derivative, wherein the concentration of the sodium borohydride solution is 2wt%;

[0041] Step A3, under the condition of nitrogen, 1.8g 1,4-dichlorobutane, 100mL DMF and 3.3mL triethylamine are mixed and stirred uniformly, then 6.6g chlorobenzothiol-thiourea derivative is added, and the temperature is raised to 90℃ to reflux for 4.5h, then it is rotary evaporated, purified by column chromatography and dried to obtain the chlorobenzothiol-thiourea derivative;

[0042] Step A4, under the condition of nitrogen, 7.5g chlorobenzothiol-thiourea derivative, 100mL DMF and 3.9mL triethylamine are mixed and stirred uniformly, then 9.6g dopamine hydrochloride is added, and the temperature is raised to 80℃ to reflux for 4h, then it is rotary evaporated, purified by column chromatography and dried to obtain the modifier.

[0043] Example 4: A preparation method of wear-resistant UV curing coating includes the following steps:

[0044] The raw materials are weighed by parts by weight, 45 parts of acrylic resin, 15 parts of acrylate modified polyurethane, 8 parts of the modifier prepared in Example 1, 3 parts of isopropyl alcohol and 20 parts of water are mixed, stirred at a speed of 400 rpm for 5 min, then 6 parts of wear-resistant agent, 0.5 parts of BYK-024 defoaming agent and 0.1 parts of BYK-333 leveling agent are added and stirred at a speed of 500 rpm for 3 min, and finally 3.5 parts of 2-hydroxy-2-methylphenyl propionone is added and stirred at a speed of 1000 rpm for 50 min, to obtain a wear-resistant UV curing coating, wherein the wear-resistant agent is a mixture of ceramic micro powder and nano molybdenum disulfide, and the mass ratio of ceramic micro powder to nano molybdenum disulfide is 1:2.

[0045] Example 5: A preparation method of a wear-resistant UV curing coating comprises the following steps:

[0046] The raw materials are weighed by parts by weight, 55 parts of acrylic resin, 20 parts of acrylate modified polyurethane, 12 parts of the modifier prepared in Example 2, 4.5 parts of isopropyl alcohol and 25 parts of water are mixed, stirred at a speed of 500 rpm for 6 min, then 8 parts of wear-resistant agent, 0.7 parts of BYK-052N defoaming agent and 0.3 parts of BYK-333 leveling agent are added and stirred at a speed of 600 rpm for 5 min, and finally 4.5 parts of benzophenone is added and stirred at a speed of 1100 rpm for 40 min, to obtain a wear-resistant UV curing coating, wherein the wear-resistant agent is a mixture of ceramic micro powder and nano molybdenum disulfide, and the mass ratio of ceramic micro powder to nano molybdenum disulfide is 1:2.

[0047] Example 6: A preparation method of a wear-resistant UV curing coating comprises the following steps:

[0048] The raw materials are weighed by parts by weight, 65 parts of acrylic resin, 25 parts of acrylate modified polyurethane, 15 parts of the modifier prepared in Example 3, 6 parts of isopropyl alcohol and 30 parts of water are mixed, stirred at a speed of 600 rpm for 8 min, then 10 parts of wear-resistant agent, 1 part of BYK-052N defoaming agent and 0.5 parts of BYK-354 leveling agent are added and stirred at a speed of 700 rpm for 6 min, and finally 5.5 parts of photoinitiator TPO is added and stirred at a speed of 1200 rpm for 30 min, to obtain a wear-resistant UV curing coating, wherein the wear-resistant agent is a mixture of ceramic micro powder and nano molybdenum disulfide, and the mass ratio of ceramic micro powder to nano molybdenum disulfide is 1:2.

[0049] Comparative Example 1: This comparative example is a UV curing coating, which is different from Example 6 in that the modifier prepared in Example 3 is not added, and the rest is the same.

[0050] Comparative Example 2: This comparative example is a UV-cured coating, which is different from Example 6 in that the modified agent prepared in Example 3 is replaced by the benzothiophen-sulfourea derivative prepared in Example 3, and the rest are the same.

[0051] Comparative Example 3: This comparative example is a UV-cured coating, which is different from Example 6 in that the modified agent prepared in Example 3 is replaced by the chlorobenzothiophen-sulfourea derivative prepared in Example 3, and the rest are the same.

[0052] Comparative Example 4: This comparative example is a UV-cured coating, which is different from Example 6 in that no wear-resistant agent is added, and the rest are the same.

[0053] The UV-cured coatings prepared in Examples 4-6 and Comparative Examples 1-3 are tested for performance:

[0054] Abrasion resistance test: (1) Test the abrasion resistance of the coating according to standard GB / T 1768-2006; (2) Use a steel wool abrasion tester, test area 1cm*1cm, weight 1KG, test distance 4CM, frequency 1 minute 50 times back and forth friction until there are scratches on the surface;

[0055] Corrosion resistance test: (1) Test the salt spray resistance of the coating according to GB / T 10125-2021, using sodium chloride salt spray for 500h; (2) Test the acid and alkali resistance of the coating according to GB / T 9274-1988;

[0056] Adhesion test: Test the adhesion of the coating according to GB / T 9286-1998;

[0057] The test results are shown in Table 1:

[0058] Table 1: Performance test results

[0059]

[0060] The UV-cured coating prepared in the present application has excellent abrasion resistance, corrosion resistance and adhesion after abrasion resistance test, corrosion resistance test and adhesion test, as shown in Table 1.

[0061] The above content is only an example and explanation of the concept of the present application, and those skilled in the art can make various modifications or supplements to the described specific examples or use similar ways to replace them, as long as they do not deviate from the scope defined by the concept of the present application, and all should belong to the protection scope of the present application.

Claims

1. A wear resistant UV-cured coating, characterized in that, The raw materials include the following weight parts: acrylic resin 45-65 parts, acrylate modified polyurethane 15-25 parts, modifier 8-15 parts, wear-resistant agent 6-10 parts, photoinitiator 3.5-5.5 parts, isopropyl alcohol 3-6 parts, defoaming agent 0.5-1 part, leveling agent 0.1-0.5 part, and water 20-30 parts; The wear-resistant agent is a mixture of ceramic micro powder and nano molybdenum disulfide, wherein the mass ratio of the ceramic micro powder to the nano molybdenum disulfide is 1:2; The modifier is prepared by refluxing chlorobenzothiophen-sulfourea derivative and dopamine hydrochloride at 80℃ for 4h, the chlorobenzothiophen-sulfourea derivative is prepared by refluxing benzothiophen-sulfourea derivative and 1,4-dichlorobutane at 80-90℃ for 3.5-4.5h, the benzothiophen-sulfourea derivative is prepared by reacting sulfourea derivative and 1-benzothiophen-2-carboxaldehyde at 110℃ for 4.5-5.5h, and then reducing with sodium borohydride solution, the sulfourea derivative is prepared by reacting 5-amino-2-nitrofluorobenzene and allyl isothiocyanate at 50℃ for 3.5-4.5h, and then reducing with hydrazine hydrate.

2. A wear resistant UV cured coating according to claim 1, wherein, The modifier is prepared by the following steps: In step A1, 5-amino-2-nitrofluorobenzene, ethanol, dibutyltin dilaurate, allyl isothiocyanate, Pd / C, hydrazine hydrate and water are used in a ratio of 0.01-0.03mol:100mL:0.0005-0.002g:0.01-0.03mol:0.1-0.3g:1.1-3.3g:100mL. ​ ​ ​ 3. A wear resistant UV cured coating according to claim 2, wherein, ​ 4. A wear resistant UV cured coating according to claim 2, wherein, In step A2, the ratio of the amounts of the thiourea derivative, 1-benzothiophen-2-carboxaldehyde, toluene, benzene and sodium borohydride solution is 0.01-0.03 mol:0.01-0.03 mol:100 mL:100 mL:15-30 mL, wherein the concentration of the sodium borohydride solution is 0.5-2 wt%.

5. A wear resistant UV cured coating according to claim 2, wherein, In step A3, the ratio of the amounts of 1,4-dichlorobutane, DMF, triethylamine and benzothiophen-thiourea derivative is 0.6-1.8 g:100 mL:1.1-3.3 mL:2.2-6.6 g.

6. A wear resistant UV cured coating according to claim 2, wherein, In step A4, the ratio of the amounts of chlorobenzothiophen-thiourea derivative, DMF, triethylamine and dopamine hydrochloride is 2.5-7.5 g:100 mL:1.3-3.9 mL:3.2-9.6 g.

7. The abrasion resistant UV cured coating of claim 1, wherein, The photoinitiator is one of 2-hydroxy-2-methylphenylpropanone, benzophenone and photoinitiator TPO.

8. The abrasion resistant UV cured coating of claim 1, wherein, The defoaming agent is one of BYK-024 defoaming agent or BYK-052N defoaming agent.

9. The abrasion resistant UV cured coating of claim 1, wherein, The leveling agent is one of BYK-333 leveling agent or BYK-354 leveling agent.

10. A process for the preparation of the abrasion resistant UV-cured coating according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: The raw materials are weighed by weight parts, the acrylic resin, the acrylic ester modified polyurethane, the modifier, the isopropyl alcohol and the water are mixed, then stirred at a speed of 400-600 rpm for 5-8 min, the wear-resistant agent, the defoaming agent and the leveling agent are added and stirred at a speed of 500-700 rpm for 3-6 min, finally the photoinitiator is added and stirred at a speed of 1000-1200 rpm for 30-50 min, thus the wear-resistant UV curing coating is obtained.

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