Quartz sand-containing environment-friendly coating as well as preparation method and application thereof

Abstract

The invention relates to the technical field of coatings, and discloses an environment-friendly coating containing quartz sand as well as a preparation method and application of the environment-friendly coating. The preparation method comprises the following steps: uniformly mixing polyurethane acrylate, hydroxyethyl methylacrylate, the reactive diluent, the fluorine-containing diluent, the cross-linking agent, sulfydryl modified benzophenone, hydrophobic modified quartz sand and the photoinitiator to obtain the environment-friendly coating containing quartz sand. The quartz sand and the ultraviolet absorption component are introduced into the photocureable coating, so that the ultraviolet resistance and the hydrophobic property of the coating are improved, and meanwhile, the coating combines the texture of the quartz sand and the environment-friendly and durable characteristics of the photocureable coating, and can be applied to a surface coating of a decorative product.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to an environmentally friendly coating containing quartz sand, a preparation method thereof, and an application thereof. Background Art

[0002] Quartz sand is a natural mineral with the characteristics of high hardness, wear resistance, good chemical stability, etc. It is an ideal environmentally friendly material. Traditional coatings need to be cured at high temperatures, while UV-curable coatings are a new type of environmentally friendly and energy-saving coating with the characteristics of high efficiency, energy saving, economy, environmental friendliness and wide adaptability. Prior art such as Chinese patent application CN103952049A discloses a crack-resistant waterproof coating, which is made of polyurethane acrylic resin, silicone acrylate emulsion, quartz sand, xylene, glyoxal, ethyl acetate, potassium silicate, titanium dioxide, toluene diisocyanate, polyvinyl alcohol and water, and has good waterproof, anti-corrosion and anti-cracking properties. However, in the process of preparing the coating, inorganic fillers such as quartz sand are not surface treated, and the compatibility of the filler with the coating matrix needs to be improved. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide an environmentally friendly coating containing quartz sand, a preparation method and application thereof. By introducing quartz sand and ultraviolet absorbing components into a light-curing coating, the ultraviolet resistance and hydrophobicity of the coating are improved. At the same time, the coating combines the texture of quartz sand with the environmentally friendly and durable characteristics of the light-curing coating, and can be used as a surface coating for decorative products.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A method for preparing an environmentally friendly coating containing quartz sand comprises the following steps:

[0006] Step (1), mixing perfluoropolyether alcohol, tetrahydrofuran, and sodium hydride, adding allyl chloride, reacting, and purifying after the reaction to obtain allyl-modified perfluoropolyether alcohol;

[0007] Quartz sand, isocyanatepropyltriethoxysilane, and tetrahydrofuran are mixed and subjected to an impregnation reaction. After the reaction is completed, the mixture is filtered and dried to obtain isocyanate-modified quartz sand. Allyl-modified perfluoropolyether alcohol, a catalyst dibutyltin dilaurate, and trichlorotrifluoroethane are mixed and dissolved, and the isocyanate-modified quartz sand is added and reacted. After the reaction is completed, the mixture is filtered, washed, and dried to obtain hydrophobic modified quartz sand.

[0008] Step (2), polyurethane acrylate, hydroxyethyl methacrylate, active diluent trimethylolpropane triacrylate, fluorine-containing diluent 1H,1H,2H,2H-perfluorooctanol acrylate, crosslinking agent pentaerythritol tetrakis(3-mercaptopropionic acid) ester, mercapto-modified benzophenone, hydrophobic modified quartz sand, and photoinitiator are stirred evenly in the dark to obtain an environmentally friendly coating containing quartz sand.

[0009] Preferably, in step (1), the molar ratio of perfluoropolyether alcohol to allyl chloride is 1:1; the mass ratio of perfluoropolyether alcohol, tetrahydrofuran, and sodium hydride is 30:45-50:2.5-3; when preparing the allyl-modified perfluoropolyether alcohol, the stirring conditions are: stirring at a temperature of 25-30°C for 2-3 hours; and the reaction conditions are: stirring and reacting at a temperature of 55-60°C for 16-20 hours.

[0010] Preferably, in step (1), the purification operation comprises: cooling to room temperature after the reaction is completed, washing with 1 mol / L hydrochloric acid aqueous solution and water in sequence until neutral, adding a solvent perfluorocyclic ether, mixing, and then separating the liquids, taking the organic phase, and removing the solvent perfluorocyclic ether by distillation under reduced pressure.

[0011] Preferably, in step (1), the mass ratio of quartz sand, isocyanatepropyltriethoxysilane, and tetrahydrofuran is 1:0.02-0.025:10; and the immersion conditions are: immersion reaction at room temperature for 1-8 hours.

[0012] Preferably, in step (1), the mass ratio of allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, trichlorotrifluoroethane, and isocyanate-based quartz sand is 10-12:0.1-0.15:20-30:2; and the reaction conditions are: reaction at a temperature of 50-60° C. for 7-9 hours.

[0013] Preferably, in step (2), the environmentally friendly coating containing quartz sand contains, by weight, 40-50 parts of polyurethane acrylate, 10-20 parts of hydroxyethyl methacrylate, 30-40 parts of reactive diluent trimethylolpropane triacrylate, 3-4 parts of fluorine-containing diluent 1H,1H,2H,2H-perfluorooctanol acrylate, 8-10 parts of crosslinking agent pentaerythritol tetrakis(3-mercaptopropionic acid), 10-15 parts of mercapto-modified benzophenone, 50-60 parts of hydrophobically modified quartz sand, and 4-5 parts of photoinitiator.

[0014] Preferably, in step (2), the mercapto-modified benzophenone is prepared by the following steps:

[0015] S21, heating diethanolamine, adding paraformaldehyde in portions, reacting after the addition is complete, adding 2,4-dihydroxybenzophenone and methanol, and continuing the reaction, and after the reaction is complete, rotary evaporation, washing, and drying to obtain hydroxyethyl-modified benzophenone;

[0016] S22. Mix and dissolve 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, and acetone, add N,N′-dicyclohexylcarbodiimide, and react. After the reaction is completed, perform post-treatment to obtain mercapto-modified benzophenone.

[0017] Preferably, when preparing the mercapto-modified benzophenone in step (2), in S21, the molar ratio of diethanolamine, paraformaldehyde, 2,4-dihydroxybenzophenone, and methanol is 1:1.05-1.1:0.5:1.2-1.5; the stepwise addition of paraformaldehyde is as follows: adding the paraformaldehyde in batches at 70°C, with the same mass added each time, adding 4-5 times, and each time with an interval of 10-15 minutes; the reaction conditions are: reacting at 80°C for 2.5-3h; and the continued reaction conditions are: continuing the reaction at 80-85°C for 3-3.5h.

[0018] Preferably, when preparing the mercapto-modified benzophenone in step (2), in S22, the mass ratio of 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, acetone, and N,N′-dicyclohexylcarbodiimide is 10:13-13.2:100-120:19-19.4; and the reaction conditions are: stirring the reaction at room temperature for 30-36 hours.

[0019] Preferably, when preparing mercapto-modified benzophenone in step (2), in S22: the post-treatment operation includes: standing for 1-2 hours after the reaction is completed, filtering, taking the filter cake, adding 0°C ice water to wash, and drying at 50°C for 24 hours.

[0020] Preferably, an environmentally friendly coating containing quartz sand is prepared by the method for preparing the environmentally friendly coating containing quartz sand as described above.

[0021] Preferably, an environmentally friendly coating containing quartz sand as described above is used in the surface coating of a decorative product.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Perfluoropolyether alcohol has the advantages of large relative molecular mass, high fluorine content, flexible molecular chain, and good solubility. The present invention utilizes perfluoropolyether alcohol with a double-terminal hydroxyl structure to undergo a nucleophilic substitution reaction with allyl chloride under catalyst conditions, introduces allyl functional groups into the perfluoropolyether alcohol, and retains some alcoholic hydroxyl groups to provide active groups for subsequent reactions. Quartz sand is impregnated with isocyanatepropyltriethoxysilane to graft isocyanate functional groups onto its surface. The isocyanate groups are further reacted with the hydroxyl groups in the allyl-modified perfluoropolyether alcohol to graft the perfluoropolyether alcohol onto the surface of the quartz sand. The lower surface energy of the perfluoropolymer is utilized to give the hydrophobically modified quartz sand excellent hydrophobic properties.

[0024] 2. The present invention uses a Mannich reaction between a broad-spectrum ultraviolet absorber 2,4-dihydroxybenzophenone and diethanolamine and paraformaldehyde to synthesize hydroxyethyl-modified benzophenone, and then uses N,N′-dicyclohexylcarbodiimide as a dehydration condensation agent to activate the carboxyl group in 3-mercaptopropionic acid, so that the primary hydroxyl group in the hydroxyethyl-modified benzophenone and the carboxyl group in 3-mercaptopropionic acid undergo an esterification reaction, thereby introducing a thiol functional group. The obtained thiol-modified benzophenone serves as a reactive ultraviolet absorber, which can utilize the thiol group to participate in the photocuring reaction of the coating and bond to the coating matrix to play a long-lasting anti-ultraviolet effect.

[0025] 3. The present invention introduces a fluorine-containing diluent 1H,1H,2H,2H-perfluorooctanol acrylate, a mercapto-modified benzophenone, and a hydrophobically modified quartz sand into a light-curable polyurethane acrylate resin, utilizing the characteristics that the mercapto group reacts efficiently with carbon-carbon double bonds and is not inhibited by oxygen, thereby improving the curing efficiency of the coating; at the same time, since the perfluoropolymer has a low surface energy and the mercapto-modified benzophenone has excellent ultraviolet absorption properties, the hydrophobicity and ultraviolet resistance of the coating are improved; in addition, since the surface of the hydrophobically modified quartz sand has not only carbon-carbon double bonds but also urethane bonds, after introducing it into the coating, it can not only participate in the light-curing process of the coating, but also has good compatibility with the polyurethane acrylate resin, further improving the compatibility and dispersibility of the quartz sand in the coating matrix. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the synthesis of mercapto-modified benzophenone in the present invention;

[0027] Figure 2 1-2 are histograms of water contact angles of Examples 1-5 and Comparative Examples 1-2 in the comprehensive performance test of the present invention;

[0028] Figure 3 It is a bar graph of the water absorption rates of Examples 1-5 and Comparative Examples 1-2 in the comprehensive performance test of the present invention. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] This embodiment discloses a method for preparing an environmentally friendly coating containing quartz sand, comprising the following steps:

[0032] Step (1), mixing perfluoropolyether alcohol, tetrahydrofuran, and sodium hydride in a mass ratio of 30:45:2.5, stirring at 25°C for 3h, adding allyl chloride, heating to 55°C and stirring for reaction for 20h, cooling to room temperature after completion of the reaction, washing with 1 mol / L hydrochloric acid aqueous solution and water in sequence until neutral, adding a solvent perfluorocyclic ether, mixing, and separating the liquids, taking the organic phase, and removing the solvent perfluorocyclic ether by distillation under reduced pressure to obtain an allyl-modified perfluoropolyether alcohol;

[0033] wherein the molar ratio of perfluoropolyether alcohol to allyl chloride is 1:1;

[0034] Quartz sand, isocyanatepropyltriethoxysilane, and tetrahydrofuran were mixed in a mass ratio of 1:0.02:10, and the mixture was immersed and reacted at room temperature for 1 hour. After the reaction was completed, the mixture was filtered, the filter cake was taken, and dried at 50°C for 24 hours to obtain isocyanate-modified quartz sand; allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, and trichlorotrifluoroethane were mixed and dissolved, and isocyanate-modified quartz sand was added. The mixture was reacted at 50°C for 9 hours. After the reaction was completed, the mixture was filtered, the filter cake was taken, and ethanol 10 times the mass of the filter cake was added for washing, and dried at 50°C for 24 hours to obtain hydrophobic modified quartz sand;

[0035] The mass ratio of allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, trichlorotrifluoroethane, and isocyanate-based quartz sand is 10:0.1:20:2;

[0036] Step (2), by weight, 40 parts of polyurethane acrylate, 20 parts of hydroxyethyl methacrylate, 40 parts of reactive diluent trimethylolpropane triacrylate, 3 parts of fluorine-containing diluent 1H,1H,2H,2H-perfluorooctanol acrylate, 8 parts of crosslinking agent pentaerythritol tetrakis(3-mercaptopropionic acid) ester, 10 parts of mercapto-modified benzophenone, 50 parts of hydrophobic modified quartz sand, and 4 parts of photoinitiator, stirred evenly in the dark to obtain an environmentally friendly coating containing quartz sand;

[0037] Wherein, the mercapto-modified benzophenone is prepared by the following steps:

[0038] S21, heating diethanolamine to 70°C, adding paraformaldehyde in portions, with the same mass added each time, adding four times, and each time with an interval of 15 minutes. After the addition is completed, heating to 80°C and reacting for 2.5 hours. After the reaction is completed, adding 2,4-dihydroxybenzophenone and methanol, and continuing to react at 80°C for 3.5 hours. After the reaction is completed, removing the solvent methanol by rotary evaporation, adding water for washing, and drying at 50°C for 24 hours to obtain hydroxyethyl modified benzophenone;

[0039] The molar ratio of diethanolamine, paraformaldehyde, 2,4-dihydroxybenzophenone, and methanol is 1:1.05:0.5:1.2;

[0040] S22, 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, and acetone were mixed and dissolved, N,N′-dicyclohexylcarbodiimide was added, and the mixture was stirred at room temperature for 36 hours. After the reaction was completed, the mixture was allowed to stand for 1 hour, filtered, and the filter cake was taken, washed with 0°C ice water, and dried at 50°C for 24 hours to obtain mercapto-modified benzophenone;

[0041] The mass ratio of 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, acetone, and N,N′-dicyclohexylcarbodiimide is 10:13:100:19.

[0042] Example 2

[0043] This embodiment discloses a method for preparing an environmentally friendly coating containing quartz sand, comprising the following steps:

[0044] Step (1), mixing perfluoropolyether alcohol, tetrahydrofuran, and sodium hydride in a mass ratio of 30:45:2.6, stirring at 25°C for 3h, adding allyl chloride, heating to 55°C and stirring for 20h, cooling to room temperature after the reaction, washing with 1mol / L hydrochloric acid aqueous solution and water to neutrality, adding solvent perfluorocyclic ether, mixing, separating the liquids, taking the organic phase, and removing the solvent perfluorocyclic ether by distillation under reduced pressure to obtain an allyl-modified perfluoropolyether alcohol;

[0045] wherein the molar ratio of perfluoropolyether alcohol to allyl chloride is 1:1;

[0046] Quartz sand, isocyanatepropyltriethoxysilane, and tetrahydrofuran were mixed in a mass ratio of 1:0.022:10, and the mixture was immersed and reacted at room temperature for 1 hour. After the reaction was completed, the mixture was filtered, the filter cake was taken, and dried at 50°C for 24 hours to obtain isocyanate-modified quartz sand; allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, and trichlorotrifluoroethane were mixed and dissolved, and isocyanate-modified quartz sand was added, and the mixture was reacted at 55°C for 8 hours. After the reaction was completed, the mixture was filtered, the filter cake was taken, and ethanol 10 times the mass of the filter cake was added for washing, and dried at 50°C for 24 hours to obtain hydrophobic modified quartz sand;

[0047] The mass ratio of allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, trichlorotrifluoroethane, and isocyanate-based quartz sand is 10.5:0.13:25:2;

[0048] Step (2), by weight, 40 parts of polyurethane acrylate, 20 parts of hydroxyethyl methacrylate, 40 parts of reactive diluent trimethylolpropane triacrylate, 3.3 parts of fluorine-containing diluent 1H,1H,2H,2H-perfluorooctanol acrylate, 8.5 parts of crosslinking agent pentaerythritol tetrakis (3-mercaptopropionic acid) ester, 12 parts of mercapto-modified benzophenone, 53 parts of hydrophobic modified quartz sand, and 4.3 parts of photoinitiator, stirred evenly in the dark to obtain an environmentally friendly coating containing quartz sand;

[0049] Wherein, the mercapto-modified benzophenone is prepared by the following steps:

[0050] S21, heating diethanolamine to 70°C, adding paraformaldehyde in portions, with the same mass added each time, adding four times, and each time with an interval of 15 minutes. After the addition is completed, heating to 80°C and reacting for 2.5 hours. After the reaction is completed, adding 2,4-dihydroxybenzophenone and methanol, and continuing to react at 80°C for 3.5 hours. After the reaction is completed, removing the solvent methanol by rotary evaporation, adding water for washing, and drying at 50°C for 24 hours to obtain hydroxyethyl modified benzophenone;

[0051] The molar ratio of diethanolamine, paraformaldehyde, 2,4-dihydroxybenzophenone, and methanol is 1:1.05:0.5:1.2;

[0052] S22, 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, and acetone were mixed and dissolved, N,N′-dicyclohexylcarbodiimide was added, and the mixture was stirred at room temperature for 36 hours. After the reaction was completed, the mixture was allowed to stand for 1 hour, filtered, and the filter cake was taken, washed with 0°C ice water, and dried at 50°C for 24 hours to obtain mercapto-modified benzophenone;

[0053] The mass ratio of 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, acetone, and N,N′-dicyclohexylcarbodiimide is 10:13.05:110:19.1.

[0054] Example 3

[0055] This embodiment discloses a method for preparing an environmentally friendly coating containing quartz sand, comprising the following steps:

[0056] Step (1), perfluoropolyether alcohol, tetrahydrofuran, and sodium hydride are mixed in a mass ratio of 30:45:2.8, stirred at 28 ° C for 2.5 hours, allyl chloride is added, the temperature is raised to 58 ° C, and the reaction is stirred for 18 hours. After the reaction is completed, it is cooled to room temperature, washed with 1 mol / L hydrochloric acid aqueous solution and water to neutrality, a solvent perfluorocyclic ether is added, and the mixture is separated, the organic phase is taken, and the solvent perfluorocyclic ether is removed by distillation under reduced pressure to obtain an allyl-modified perfluoropolyether alcohol;

[0057] wherein the molar ratio of perfluoropolyether alcohol to allyl chloride is 1:1;

[0058] Quartz sand, isocyanatepropyltriethoxysilane, and tetrahydrofuran were mixed in a mass ratio of 1:0.023:10, and the mixture was immersed in the mixture for reaction at room temperature for 1 hour. After the reaction was completed, the mixture was filtered, the filter cake was taken, and the mixture was dried at 50°C for 24 hours to obtain isocyanate-modified quartz sand. Allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, and trichlorotrifluoroethane were mixed and dissolved, and the mixture was added with isocyanate-modified quartz sand. The mixture was reacted at 55°C for 8 hours. After the reaction was completed, the mixture was filtered, the filter cake was taken, and the mixture was washed with ethanol 10 times the mass of the filter cake, and dried at 50°C for 24 hours to obtain hydrophobic modified quartz sand.

[0059] The mass ratio of allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, trichlorotrifluoroethane, and isocyanate-based quartz sand is 11:0.13:25:2;

[0060] Step (2), by weight, 40 parts of polyurethane acrylate, 20 parts of hydroxyethyl methacrylate, 40 parts of reactive diluent trimethylolpropane triacrylate, 3.5 parts of fluorine-containing diluent 1H,1H,2H,2H-perfluorooctanol acrylate, 9 parts of crosslinking agent pentaerythritol tetrakis (3-mercaptopropionic acid) ester, 13 parts of mercapto-modified benzophenone, 55 parts of hydrophobic modified quartz sand, and 4.5 parts of photoinitiator, stirred evenly in the dark to obtain an environmentally friendly coating containing quartz sand;

[0061] Wherein, the mercapto-modified benzophenone is prepared by the following steps:

[0062] S21, heating diethanolamine to 70°C, adding paraformaldehyde in portions, with the same mass added each time, adding four times, and each time with an interval of 15 minutes. After the addition is completed, heating to 80°C and reacting for 2.8 hours. After the reaction is completed, adding 2,4-dihydroxybenzophenone and methanol, and continuing to react at 80°C for 3.5 hours. After the reaction is completed, removing the solvent methanol by rotary evaporation, adding water for washing, and drying at 50°C for 24 hours to obtain hydroxyethyl modified benzophenone;

[0063] The molar ratio of diethanolamine, paraformaldehyde, 2,4-dihydroxybenzophenone, and methanol is 1:1.05:0.5:1.2;

[0064] S22, 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, and acetone were mixed and dissolved, N,N′-dicyclohexylcarbodiimide was added, and the mixture was stirred at room temperature for 36 hours. After the reaction was completed, the mixture was allowed to stand for 1 hour, filtered, and the filter cake was taken, washed with 0°C ice water, and dried at 50°C for 24 hours to obtain mercapto-modified benzophenone;

[0065] The mass ratio of 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, acetone, and N,N′-dicyclohexylcarbodiimide is 10:13.1:110:19.2.

[0066] Example 4

[0067] This embodiment discloses a method for preparing an environmentally friendly coating containing quartz sand, comprising the following steps:

[0068] Step (1), perfluoropolyether alcohol, tetrahydrofuran, and sodium hydride are mixed in a mass ratio of 30:45:3, stirred at 30°C for 2h, allyl chloride is added, the temperature is raised to 60°C, and the reaction is stirred for 16h. After the reaction is completed, the mixture is cooled to room temperature, washed with 1 mol / L hydrochloric acid aqueous solution and water until neutral, a solvent perfluorocyclic ether is added, and the mixture is separated, the organic phase is taken, and the solvent perfluorocyclic ether is removed by distillation under reduced pressure to obtain an allyl-modified perfluoropolyether alcohol;

[0069] wherein the molar ratio of perfluoropolyether alcohol to allyl chloride is 1:1;

[0070] Quartz sand, isocyanatepropyltriethoxysilane, and tetrahydrofuran were mixed in a mass ratio of 1:0.024:10, and the mixture was immersed in the mixture for reaction at room temperature for 1 hour. After the reaction was completed, the mixture was filtered, the filter cake was taken, and the mixture was dried at 50°C for 24 hours to obtain isocyanate-modified quartz sand. Allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, and trichlorotrifluoroethane were mixed and dissolved, and the mixture was added with isocyanate-modified quartz sand. The mixture was reacted at 55°C for 8 hours. After the reaction was completed, the mixture was filtered, the filter cake was taken, and the mixture was washed with ethanol 10 times the mass of the filter cake, and dried at 50°C for 24 hours to obtain hydrophobic modified quartz sand.

[0071] The mass ratio of allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, trichlorotrifluoroethane, and isocyanate-based quartz sand is 11.5:0.13:25:2;

[0072] Step (2), by weight, 40 parts of polyurethane acrylate, 20 parts of hydroxyethyl methacrylate, 40 parts of reactive diluent trimethylolpropane triacrylate, 3.8 parts of fluorine-containing diluent 1H,1H,2H,2H-perfluorooctanol acrylate, 9.5 parts of crosslinking agent pentaerythritol tetrakis (3-mercaptopropionic acid) ester, 14 parts of mercapto-modified benzophenone, 58 parts of hydrophobic modified quartz sand, and 4.8 parts of photoinitiator, stirred evenly in the dark to obtain an environmentally friendly coating containing quartz sand;

[0073] Wherein, the mercapto-modified benzophenone is prepared by the following steps:

[0074] S21, heating diethanolamine to 70°C, adding paraformaldehyde in portions, with the same mass added each time, adding four times, and each time with an interval of 15 minutes. After the addition is completed, heating to 80°C and reacting for 2.8 hours. After the reaction is completed, adding 2,4-dihydroxybenzophenone and methanol, and continuing to react at 80°C for 3.5 hours. After the reaction is completed, removing the solvent methanol by rotary evaporation, adding water for washing, and drying at 50°C for 24 hours to obtain hydroxyethyl modified benzophenone;

[0075] The molar ratio of diethanolamine, paraformaldehyde, 2,4-dihydroxybenzophenone, and methanol is 1:1.1:0.5:1.5;

[0076] S22, 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, and acetone were mixed and dissolved, N,N′-dicyclohexylcarbodiimide was added, and the mixture was stirred at room temperature for 36 hours. After the reaction was completed, the mixture was allowed to stand for 1 hour, filtered, and the filter cake was taken, washed with 0°C ice water, and dried at 50°C for 24 hours to obtain mercapto-modified benzophenone;

[0077] The mass ratio of 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, acetone, and N,N′-dicyclohexylcarbodiimide is 10:13.15:110:19.3.

[0078] Example 5

[0079] This embodiment discloses a method for preparing an environmentally friendly coating containing quartz sand, comprising the following steps:

[0080] Step (1), perfluoropolyether alcohol, tetrahydrofuran, and sodium hydride are mixed in a mass ratio of 30:50:3, stirred at 30°C for 2h, allyl chloride is added, the temperature is raised to 60°C, and the reaction is stirred for 16h. After the reaction is completed, the mixture is cooled to room temperature, washed with 1mol / L hydrochloric acid aqueous solution and water until neutral, a solvent perfluorocyclic ether is added, the mixture is separated, the organic phase is taken, and the solvent perfluorocyclic ether is removed by distillation under reduced pressure to obtain an allyl-modified perfluoropolyether alcohol;

[0081] wherein the molar ratio of perfluoropolyether alcohol to allyl chloride is 1:1;

[0082] Quartz sand, isocyanatepropyltriethoxysilane, and tetrahydrofuran were mixed in a mass ratio of 1:0.025:10, and the mixture was immersed and reacted at room temperature for 1 hour. After the reaction was completed, the mixture was filtered, the filter cake was taken, and dried at 50°C for 24 hours to obtain isocyanate-modified quartz sand; allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, and trichlorotrifluoroethane were mixed and dissolved, and isocyanate-modified quartz sand was added. The mixture was reacted at 60°C for 7 hours. After the reaction was completed, the mixture was filtered, the filter cake was taken, and ethanol 10 times the mass of the filter cake was added for washing, and dried at 50°C for 24 hours to obtain hydrophobic modified quartz sand;

[0083] The mass ratio of allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, trichlorotrifluoroethane, and isocyanate-based quartz sand is 12:0.15:30:2;

[0084] Step (2), by weight, 40 parts of polyurethane acrylate, 20 parts of hydroxyethyl methacrylate, 40 parts of reactive diluent trimethylolpropane triacrylate, 4 parts of fluorine-containing diluent 1H,1H,2H,2H-perfluorooctanol acrylate, 10 parts of crosslinking agent pentaerythritol tetrakis (3-mercaptopropionic acid) ester, 15 parts of mercapto-modified benzophenone, 60 parts of hydrophobic modified quartz sand, and 5 parts of photoinitiator, stirred evenly in the dark to obtain an environmentally friendly coating containing quartz sand;

[0085] Wherein, the mercapto-modified benzophenone is prepared by the following steps:

[0086] S21, heating diethanolamine to 70°C, adding paraformaldehyde in portions, with the same mass added each time, adding four times, and each time with an interval of 15 minutes. After the addition is completed, heating to 80°C and reacting for 3 hours. After the reaction is completed, adding 2,4-dihydroxybenzophenone and methanol, and continuing to react at 85°C for 3 hours. After the reaction is completed, removing the solvent methanol by rotary evaporation, adding water for washing, and drying at 50°C for 24 hours to obtain hydroxyethyl modified benzophenone;

[0087] The molar ratio of diethanolamine, paraformaldehyde, 2,4-dihydroxybenzophenone, and methanol is 1:1.1:0.5:1.5;

[0088] S22, 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, and acetone were mixed and dissolved, N,N′-dicyclohexylcarbodiimide was added, and the mixture was stirred at room temperature for 36 hours. After the reaction was completed, the mixture was allowed to stand for 1 hour, filtered, and the filter cake was taken, washed with 0°C ice water, and dried at 50°C for 24 hours to obtain mercapto-modified benzophenone;

[0089] The mass ratio of 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, acetone, and N,N′-dicyclohexylcarbodiimide is 10:13.2:120:19.4.

[0090] Comparative Example 1

[0091] This comparative example discloses a method for preparing an environmentally friendly coating containing quartz sand, comprising the following steps:

[0092] In parts by mass, 40 parts of polyurethane acrylate, 20 parts of hydroxyethyl methacrylate, 40 parts of reactive diluent trimethylolpropane triacrylate, 3 parts of fluorine-containing diluent 1H,1H,2H,2H-perfluorooctanol acrylate, 8 parts of crosslinking agent pentaerythritol tetrakis(3-mercaptopropionate), 10 parts of mercapto-modified benzophenone, 50 parts of quartz sand, and 4 parts of photoinitiator are stirred evenly in the dark to obtain an environmentally friendly coating containing quartz sand;

[0093] Wherein, the mercapto-modified benzophenone is prepared by the following steps:

[0094] S1. Diethanolamine was heated to 70°C, and paraformaldehyde was added in portions. The mass of each addition was the same, and the number of additions was 4 times, with an interval of 15 minutes between each addition. After the addition was completed, the temperature was raised to 80°C and the reaction was carried out for 2.5 hours. After the reaction was completed, 2,4-dihydroxybenzophenone and methanol were added, and the reaction was continued at 80°C for 3.5 hours. After the reaction was completed, the solvent methanol was removed by rotary evaporation, and water was added for washing. The mixture was dried at 50°C for 24 hours to obtain hydroxyethyl modified benzophenone;

[0095] The molar ratio of diethanolamine, paraformaldehyde, 2,4-dihydroxybenzophenone, and methanol is 1:1.05:0.5:1.2;

[0096] S2. 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, and acetone were mixed and dissolved, N,N′-dicyclohexylcarbodiimide was added, and the mixture was stirred at room temperature for 36 hours. After the reaction was completed, the mixture was allowed to stand for 1 hour, filtered, and the filter cake was taken, washed with 0°C ice water, and dried at 50°C for 24 hours to obtain mercapto-modified benzophenone;

[0097] The mass ratio of 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, acetone, and N,N′-dicyclohexylcarbodiimide is 10:13:100:19.

[0098] Comparative Example 2

[0099] This comparative example discloses a method for preparing an environmentally friendly coating containing quartz sand, comprising the following steps:

[0100] Step (1), mixing perfluoropolyether alcohol, tetrahydrofuran, and sodium hydride in a mass ratio of 30:45:2.5, stirring at 25°C for 3h, adding allyl chloride, heating to 55°C and stirring for reaction for 20h, cooling to room temperature after completion of the reaction, washing with 1 mol / L hydrochloric acid aqueous solution and water in sequence until neutral, adding a solvent perfluorocyclic ether, mixing, and separating the liquids, taking the organic phase, and removing the solvent perfluorocyclic ether by distillation under reduced pressure to obtain an allyl-modified perfluoropolyether alcohol;

[0101] wherein the molar ratio of perfluoropolyether alcohol to allyl chloride is 1:1;

[0102] Quartz sand, isocyanatepropyltriethoxysilane, and tetrahydrofuran were mixed in a mass ratio of 1:0.02:10, and the mixture was immersed and reacted at room temperature for 1 hour. After the reaction was completed, the mixture was filtered, the filter cake was taken, and dried at 50°C for 24 hours to obtain isocyanate-modified quartz sand; allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, and trichlorotrifluoroethane were mixed and dissolved, and isocyanate-modified quartz sand was added. The mixture was reacted at 50°C for 9 hours. After the reaction was completed, the mixture was filtered, the filter cake was taken, and ethanol 10 times the mass of the filter cake was added for washing, and dried at 50°C for 24 hours to obtain hydrophobic modified quartz sand;

[0103] The mass ratio of allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, trichlorotrifluoroethane, and isocyanate-based quartz sand is 10:0.1:20:2;

[0104] Step (2), by weight, 40 parts of polyurethane acrylate, 20 parts of hydroxyethyl methacrylate, 40 parts of active diluent trimethylolpropane triacrylate, 3 parts of fluorine-containing diluent 1H,1H,2H,2H-perfluorooctanol acrylate, 8 parts of crosslinking agent pentaerythritol tetrakis (3-mercaptopropionic acid) ester, 10 parts of 2,4-dihydroxybenzophenone, 50 parts of hydrophobic modified quartz sand, and 4 parts of photoinitiator are stirred evenly in the dark to obtain an environmentally friendly coating containing quartz sand.

[0105] In the above embodiments and comparative examples: perfluoropolyether alcohol is from Solvay Group Co., Ltd., with the product name of double-terminal Z-type perfluoropolyether alcohol and a molecular weight of 1500 g / mol; isocyanatepropyltriethoxysilane is from Aladdin Biochemical Technology Co., Ltd., with CAS number: 24801-88-5; polyurethane acrylate is from Nanjing Jiazhong Chemical Technology Co., Ltd., with the product name of polyurethane acrylate JZ-302; 1H,1H,2H,2H-perfluorooctanol acrylate is from Aladdin Biochemical Technology Co., Ltd., with CAS number: 17527-29-6; the photoinitiator is commercially available, with the product name of photoinitiator 1173; and the quartz sand is commercially available, with a specification of 325 mesh.

[0106] Test example

[0107] The environmentally friendly coatings containing quartz sand prepared in Examples 1-5 and Comparative Examples 1-2 were cured under UV-LED light for 30 minutes, and comprehensive performance tests were performed after the curing was completed. Specific test results are shown in Table 1:

[0108] Table 1

[0109]

[0110] The detection of each indicator in Table 1 is based on the following standards: the water contact angle is measured by measuring the contact angle of the coating surface formed after curing of Examples 1-5 and Comparative Examples 1-2 using a contact angle meter; the water absorption rate is measured with reference to HGT3344 "Determination of Water Absorption of Paint Films"; the adhesion is measured with reference to GB / T1720 "Determination of Adhesion of Paint Films"; the UV resistance is represented by the discoloration level, and the specific test method is: a QUV ultraviolet accelerated aging test is carried out in a UV aging test equipment for 800 hours. After the test is completed, the discoloration level is determined with reference to GB / T1766 "Rating Method for Aging of Paints and Varnishes".

[0111] According to the test results in Table 1, it can be seen that the environmentally friendly coating containing quartz sand prepared in the present invention has anti-ultraviolet properties and waterproof properties.

[0112] In the present invention, isocyanate groups react further with the hydroxyl groups in the allyl-modified perfluoropolyether alcohol to graft the perfluoropolyether alcohol onto the surface of quartz sand. The low surface energy of the perfluoropolymer imparts excellent hydrophobicity to the hydrophobically modified quartz sand. Comparative Example 1, which did not undergo surface modification of the quartz sand and lacked the hydrophobicity-enhancing effect of the perfluoropolyether alcohol, exhibited a lower water contact angle and a higher water absorption rate than the examples.

[0113] The present invention utilizes a mercapto-modified benzophenone made from the broad-spectrum UV absorber 2,4-dihydroxybenzophenone as a reactive UV absorber. The mercapto group can participate in the coating's photocuring reaction, bonding to the coating matrix and providing long-lasting UV protection. Comparative Example 2 does not modify the 2,4-dihydroxybenzophenone, and the UV-absorbing component is more susceptible to migration, resulting in inferior UV protection compared to the examples.

[0114] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an environmentally friendly coating containing quartz sand, comprising the following steps: Polyurethane acrylate, hydroxyethyl methacrylate, active diluent, fluorine-containing diluent, crosslinking agent, mercapto-modified benzophenone, hydrophobic modified quartz sand and photoinitiator are stirred evenly in the dark to obtain an environmentally friendly coating containing quartz sand.

2. The method for preparing an environmentally friendly coating containing quartz sand according to claim 1, wherein: When preparing the environmentally friendly coating containing quartz sand: The environmentally friendly coating containing quartz sand contains, in parts by mass, 40-50 parts of polyurethane acrylate, 10-20 parts of hydroxyethyl methacrylate, 30-40 parts of reactive diluent trimethylolpropane triacrylate, 3-4 parts of fluorine-containing diluent 1H,1H,2H,2H-perfluorooctanol acrylate, 8-10 parts of crosslinking agent pentaerythritol tetrakis(3-mercaptopropionic acid), 10-15 parts of mercapto-modified benzophenone, 50-60 parts of hydrophobically modified quartz sand, and 4-5 parts of photoinitiator.

3. The method for preparing an environmentally friendly coating containing quartz sand according to claim 1, wherein: When preparing the environmentally friendly coating containing quartz sand: The active diluent is trimethylolpropane triacrylate; the fluorine-containing diluent is 1H,1H,2H,2H-perfluorooctanol acrylate; and the crosslinking agent is pentaerythritol tetrakis (3-mercaptopropionate).

4. The method for preparing an environmentally friendly coating containing quartz sand according to claim 1, wherein: When preparing the environmentally friendly coating containing quartz sand, the hydrophobic modified quartz sand is prepared by the following steps: S1, mixing perfluoropolyether alcohol, tetrahydrofuran, and sodium hydride, adding allyl chloride, reacting, and purifying after the reaction to obtain allyl-modified perfluoropolyether alcohol; S2, mixing quartz sand, isocyanatepropyltriethoxysilane, and tetrahydrofuran, and impregnating the mixture for reaction. After the reaction is completed, filtering and drying the mixture to obtain isocyanate-based quartz sand; S3. Mix and dissolve the allyl-modified perfluoropolyether alcohol, the catalyst dibutyltin dilaurate, and trichlorotrifluoroethane, add isocyanate-based quartz sand, and react. After the reaction is completed, filter, wash, and dry to obtain hydrophobic modified quartz sand.

5. The method for preparing an environmentally friendly coating containing quartz sand according to claim 4, characterized in that: When preparing the hydrophobic modified quartz sand in the environmentally friendly coating containing quartz sand: In S1, the molar ratio of perfluoropolyether alcohol to allyl chloride is 1:1; the mass ratio of perfluoropolyether alcohol, tetrahydrofuran, and sodium hydride is 30:45-50:2.5-3; the stirring conditions are: stirring at 25-30°C for 2-3 hours; the reaction conditions are: stirring at 55-60°C for 16-20 hours; In S2, the mass ratio of quartz sand, isocyanatepropyltriethoxysilane, and tetrahydrofuran is 1:0.02-0.025:10; and the immersion conditions are: immersion reaction at room temperature for 1-8 hours.

6. The method for preparing an environmentally friendly coating containing quartz sand according to claim 4, characterized in that: When preparing the hydrophobic modified quartz sand in the environmentally friendly coating containing quartz sand: In S3, the mass ratio of allyl-modified perfluoropolyether alcohol, catalyst dibutyltin dilaurate, trichlorotrifluoroethane, and isocyanate-based quartz sand is 10-12:0.1-0.15:20-30:2; and the reaction conditions are: reaction at a temperature of 50-60° C. for 7-9 hours.

7. The method for preparing an environmentally friendly coating containing quartz sand according to claim 1, characterized in that: When preparing the environmentally friendly coating containing quartz sand, the mercapto-modified benzophenone is prepared by the following steps: S1. Heating diethanolamine, adding paraformaldehyde in portions, reacting, adding 2,4-dihydroxybenzophenone and methanol, and continuing the reaction. After the reaction is completed, rotary evaporation, washing, and drying to obtain hydroxyethyl modified benzophenone; S2. Mix and dissolve 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, and acetone, add N,N′-dicyclohexylcarbodiimide, and react. After the reaction is completed, perform post-treatment to obtain mercapto-modified benzophenone.

8. The method for preparing an environmentally friendly coating containing quartz sand according to claim 7, characterized in that: When preparing the mercapto-modified benzophenone in the environmentally friendly coating containing quartz sand: In S1, the molar ratio of diethanolamine, paraformaldehyde, 2,4-dihydroxybenzophenone, and methanol is 1:1.05-1.1:0.5:1.2-1.5; the stepwise addition of paraformaldehyde is as follows: adding the same mass of paraformaldehyde in 4-5 additions at 70°C, with an interval of 10-15 minutes between each addition; the reaction is carried out at 80°C for 2.5-3 hours; and the continued reaction is carried out at 80-85°C for 3-3.5 hours. In S2, the mass ratio of 3-mercaptopropionic acid, hydroxyethyl-modified benzophenone, acetone, and N,N′-dicyclohexylcarbodiimide is 10:13-13.2:100-120:19-19.4; and the reaction conditions are: stirring and reacting at room temperature for 30-36 hours.

9. An environmentally friendly coating containing quartz sand prepared by the method for preparing an environmentally friendly coating containing quartz sand according to any one of claims 1 to 8.

10. Use of the environmentally friendly paint containing quartz sand according to claim 9 in the surface coating of decorative products.

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