A hydrophobic brightening coating composition for tunnels and preparation method thereof

Abstract

The present invention relates to a hydrophobic brightening coating composition for tunnels and its preparation method. This invention uses an acrylate resin emulsion as the resin matrix, which is modified by adding fluorinated silicone oil to enhance its hydrophobicity. Furthermore, modified hollow glass microspheres and modified mica powder are added to enhance its reflective properties. The active groups of the modified hollow glass microspheres and modified mica powder bond with the active groups in the fluorinated silicone oil-modified acrylate emulsion, further enhancing the durability of the hydrophobic brightening coating composition. The resulting hydrophobic brightening coating exhibits excellent water resistance, reflectivity, and durability.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a hydrophobic brightening coating composition for tunnels and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of expressway construction in my country, the mileage of highway tunnels has also shown a rapid growth trend. The average annual increase in highway tunnel mileage exceeds 1,000 kilometers. Driving in tunnels must meet safety, comfort, and energy efficiency requirements. The existing highway tunnel lighting quality evaluation index system, consisting of indicators such as the contrast display coefficient (QC), the luminance of the 2-meter-high walls on both sides of the tunnel, the luminance uniformity of the middle section and the longitudinal luminance uniformity of the centerline, and the flicker frequency of the lighting arrangement, directly determines whether the tunnel lighting meets these safety, comfort, and energy efficiency requirements.

[0003] Tunnel wall materials influence various parameters within the tunnel lighting quality evaluation index system. Tunnel decorative materials can be broadly categorized into six categories: concrete (undecorated), paint, tile (ceramic tile), coated fiber-reinforced concrete panels (such as Vitra and Kaso), composite aluminum panels (such as fluorocarbon aluminum and porcelain-baked aluminum), and enameled steel. Research has shown that applying reflective coatings to tunnel sidewalls improves internal lighting and contributes to safer rescue operations.

[0004] Reflective coatings are primarily composed of a polymer resin matrix and reflective fillers. Polymer matrices include acrylic resins, polyurethane resins, epoxy resins, and polyester resins. Reflective fillers include glass beads, silver aluminum powder, and titanium dioxide. Reflective coatings work based on the principle of retroreflection, utilizing the illumination and reflection of headlights to illuminate the road ahead, increasing the distance at which drivers can detect objects ahead, giving them more time to take appropriate safety measures.

[0005] Patent CN105130344A discloses a tunnel fireproof and energy-saving reflective coating. This coating is composed of sulphoaluminate cement, slag powder, filler, fly ash, reflective material, and flame retardant. This invention offers sustained fire resistance and significant reflection from various light sources. Compared to similar reflective coatings, it offers significantly higher fireproofing and better reflectivity. It can be widely used in tunnel fireproofing and energy-saving projects. It is free of toxic and polluting substances, is easy to apply, and saves energy.

[0006] Patent CN111777888A discloses a self-luminous reflective coating for the inner wall of a highway tunnel and an application method thereof. The self-luminous reflective coating for the inner wall of a highway tunnel provided by the method has the following advantages: (1) energy-saving and environmentally friendly, which can significantly reduce the energy consumption of highway tunnels while meeting the requirements of tunnel lighting; (2) low maintenance cost, good weather resistance, strong adhesion, good corrosion resistance, and durability that is 4-5 times that of lighting fixtures; (3) short drying time, easy construction, low organic matter content, and environmentally friendly; (4) the composite coating has a large retroreflection coefficient, a long minimum viewing distance, and good reflective effect.

[0007] Patent CN118185355A discloses a process for preparing a reflective coating adhesive with high-strength adhesive properties. This process significantly enhances the adhesive properties of the coating adhesive by adding components such as carboxymethyl cellulose, polyvalerolactone, and diacetone acrylate. This process effectively achieves the goal of improving the adhesive's bonding effectiveness by improving the adhesive's components, avoiding the significant shedding of the coating when used in harsh outdoor environments due to the use of a high concentration of water-based ingredients. This process significantly facilitates the long-term use of the reflective coating adhesive.

[0008] However, existing reflective coatings are easily soiled and difficult to clean, resulting in a short service life and often losing their reflective effect after a period of use. Tunnels, however, are a special type of highway infrastructure with relatively small interior spaces, making maintenance and cleaning of tunnel walls difficult. Therefore, there is an urgent need to develop a reflective coating that is dirt-resistant, long-lasting, and has a high reflectivity.

[0009] To address these challenges, the present invention provides a hydrophobic, brightening coating composition that exhibits excellent hydrophobicity, resists staining, and exhibits superior light reflectivity and durability. The present invention utilizes an acrylic resin emulsion as the resin matrix, which is modified by adding fluorinated silicone oil to enhance its hydrophobicity. Furthermore, the composition enhances light reflectivity by adding modified hollow glass microspheres and modified mica powder. The active groups of the modified hollow glass microspheres and modified mica powder bond with the active groups in the fluorinated silicone oil-modified acrylic emulsion, further enhancing the durability of the hydrophobic, brightening coating composition. Summary of the Invention

[0010] To address the above technical issues, the present invention provides a hydrophobic brightening coating composition for tunnels and a method for preparing the same. The resulting hydrophobic brightening coating composition for tunnels exhibits excellent hydrophobicity, light reflectivity, and durability. The present invention is achieved through the following technical solutions:

[0011] A hydrophobic brightening coating composition for tunnels comprises the following components, in parts by weight: 45 parts of fluorine-containing silicone oil-modified acrylate emulsion, 15-30 parts of modified hollow glass microspheres, 5-10 parts of modified mica powder, 3-5 parts of titanium dioxide, 2-5 parts of wetting agent, 2-6 parts of defoaming agent, and 1-5 parts of thickener.

[0012] Furthermore, the particle size of the modified hollow glass microspheres is 40-80 microns, and the modified hollow glass microspheres are hollow glass microspheres with surface hydroxylation. The modification process of the modified hollow glass microspheres is as follows:

[0013] A certain mass of hollow glass microspheres is added to a certain concentration of sodium hydroxide solution, stirred at room temperature for 2 to 3 hours, the hollow glass microspheres are filtered out, and washed with deionized water for 3 to 5 times until the pH value of the washing solution is within the range of 6 to 8. The obtained hollow glass microspheres are then vacuum dried at 60 to 80°C for 6 to 8 hours;

[0014] Furthermore, the modified mica powder is in the form of flakes, and the particle size of the modified mica powder is 5-15 μm; the modified mica powder is surface hydroxylated mica powder.

[0015] The modification process of the modified mica powder is as follows:

[0016] Add a certain mass of mica powder to a certain concentration of sodium hydroxide solution, stir at room temperature for 3 to 5 hours, filter out the mica powder, wash it with deionized water 2 to 5 times until the pH value of the washing solution is within the range of 6 to 8, and then vacuum dry the obtained mica powder at 60 to 80°C for 6 to 8 hours;

[0017] Furthermore, the titanium dioxide is rutile titanium dioxide;

[0018] Furthermore, the wetting agent is one or a combination of two or more of sodium dodecylbenzenesulfonate, sodium lauryl sulfate, and sodium stearate.

[0019] Furthermore, the defoaming agent is one of BYK-024, BYK-028, OS-5201, or a combination of two or more.

[0020] Furthermore, the thickener is one or a combination of two or more of PUR40, PUR41, and ASE-60.

[0021] Furthermore, the fluorinated silicone oil-modified acrylate emulsion is prepared from 40 parts of methyl methacrylate, 10-20 parts of isooctyl acrylate, 5-10 parts of hydroxyethyl acrylate, 8-15 parts of fluorinated silicone oil, 30-40 parts of acetone, 1-5 parts of anionic emulsifier, 2-6 parts of nonionic emulsifier, 1-4 parts of initiator, and 20-30 parts of deionized water;

[0022] Furthermore, the structural formula of the fluorine-containing silicone oil is as follows:

[0023]

[0024] Furthermore, the preparation process of the fluorinated silicone oil modified acrylate emulsion is as follows:

[0025] 1-4 parts of initiator and 30-40 parts of acetone are added to a reaction vessel and stirred to completely dissolve the initiator. Then, 40 parts of methyl methacrylate, 10-20 parts of isooctyl acrylate, 5-10 parts of hydroxyethyl acrylate and 8-15 parts of fluorinated silicone oil are added and stirred evenly. The temperature is raised to 70-85°C and refluxed for 2-3 hours. After the reaction is completed, the resulting product is cooled to room temperature. Then, 1-5 parts of anionic emulsifier, 2-6 parts of nonionic emulsifier and 20-40 parts of deionized water are added and stirred at high speed to obtain a fluorinated silicone oil modified acrylate emulsion.

[0026] Furthermore, the anionic emulsifier is selected from one or a combination of two or more of sodium lauryl sulfate, sodium dodecylbenzenesulfonate, and disodium 1,2-dodecyl diether disulfonate. The nonionic emulsifier is selected from fatty alcohol polyoxyethylene ether.

[0027] Furthermore, the initiator is selected from one or a combination of two or more of ammonium persulfate, sodium persulfate, potassium persulfate, and azobisisobutyronitrile.

[0028] Furthermore, the preparation process of the hydrophobic brightening coating composition for tunnels is as follows:

[0029] 45 parts of fluorine-containing silicone oil-modified acrylic emulsion, 15-30 parts of modified hollow glass microspheres, and 5-10 parts of modified mica powder are stirred and mixed for 2-3 hours to obtain a mixed solution; 2-6 parts of a defoamer, 3-5 parts of titanium dioxide, 2-5 parts of a wetting agent, and 1-5 parts of a thickener are added to the above mixed solution and stirred evenly to obtain a hydrophobic brightening coating composition for tunnels.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention uses fluorinated silicone oil to modify an acrylate emulsion to obtain a fluorinated silicone oil-modified acrylate emulsion. The fluorinated silicone oil has unsaturated double bonds and can participate in the free radical polymerization of the acrylate emulsion, embedding the fluorinated silicone oil into the acrylate polymer chain segments. The fluorinated silicone oil contains fluorinated groups and siloxane segments, both of which are hydrophobic groups. Using the fluorinated silicone oil-modified acrylate emulsion to prepare a hydrophobic brightening coating composition can increase the surface tension and hydrophobicity of the resulting coating composition.

[0032] The hollow glass microspheres and mica powder used in the present application are activated to expose highly active hydroxyl groups on their surfaces. During the preparation of the hydrophobic brightening coating composition, these exposed hydroxyl groups can undergo a dehydration condensation reaction with the silanol groups contained in the fluorinated silicone oil, thereby improving the binding properties of the hollow glass microspheres and mica powder in the system, which is of great help in improving the reflectivity and durability of the resulting coating composition.

[0033] The hollow glass microspheres and mica powder used in this application belong to two systems of reflective powder. Among them, the hollow glass microspheres have a circular structure, and the mica powder has a flaky structure. The two cooperate with each other to further improve the reflectivity of the resulting coating composition. DETAILED DESCRIPTION

[0034] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work premise belong to the scope of protection of the present invention. Those who do not specify specific conditions in the embodiments are carried out according to normal conditions or the conditions recommended by the manufacturer. Those whose reagents or instruments are not specified by the manufacturer are conventional products that can be purchased commercially.

[0035] Preparation Example 1

[0036] Preparation of fluorinated silicone oil modified acrylate emulsion:

[0037] 2 parts of ammonium persulfate and 35 parts of acetone were added to a reaction vessel and stirred to completely dissolve the ammonium persulfate. Then, 40 parts of methyl methacrylate, 12 parts of isooctyl acrylate, 6-hydroxyethyl acrylate and 8 parts of fluorinated silicone oil were added and stirred evenly. The temperature was raised to 75°C and refluxed for 3 hours. After the reaction was completed, the resulting product was cooled to room temperature. Then, 2 parts of sodium lauryl sulfate, 3 parts of fatty alcohol polyoxyethylene ether and 30 parts of deionized water were added and stirred at high speed to obtain a fluorinated silicone oil-modified acrylate emulsion.

[0038] Preparation Example 2

[0039] Preparation of fluorinated silicone oil modified acrylate emulsion:

[0040] 3 parts of potassium persulfate and 30 parts of acetone were added to a reaction vessel and stirred to completely dissolve the potassium persulfate. Then, 40 parts of methyl methacrylate, 14 parts of isooctyl acrylate, 5-hydroxyethyl acrylate and 12 parts of fluorinated silicone oil were added and stirred evenly. The temperature was raised to 70°C and refluxed for 3 hours. After the reaction was completed, the resulting product was cooled to room temperature. Then, 1 part of sodium lauryl sulfate, 4 parts of fatty alcohol polyoxyethylene ether and 35 parts of deionized water were added and stirred at high speed to obtain a fluorinated silicone oil-modified acrylate emulsion.

[0041] Preparation Example 3

[0042] Preparation of fluorinated silicone oil modified acrylate emulsion:

[0043] 2 parts of potassium persulfate and 35 parts of acetone were added to a reaction vessel and stirred to completely dissolve the potassium persulfate. Then, 40 parts of methyl methacrylate, 15 parts of isooctyl acrylate, 5-hydroxyethyl acrylate and 15 parts of fluorinated silicone oil were added and stirred evenly. The temperature was raised to 75° C. and refluxed for 2 hours. After the reaction was completed, the resulting product was cooled to room temperature. Then, 1 part of sodium dodecylbenzenesulfonate, 4 parts of fatty alcohol polyoxyethylene ether and 35 parts of deionized water were added and stirred at high speed to obtain a fluorinated silicone oil-modified acrylate emulsion.

[0044] Comparative Preparation Example 1

[0045] Preparation of fluorinated silicone oil modified acrylate emulsion:

[0046] 2 parts of ammonium persulfate and 35 parts of acetone were added to a reaction vessel and stirred to completely dissolve the ammonium persulfate. Then, 40 parts of methyl methacrylate, 12 parts of isooctyl acrylate, 6-hydroxyethyl acrylate and 6 parts of fluorinated silicone oil were added and stirred evenly. The temperature was raised to 75°C and refluxed for 3 hours. After the reaction was completed, the resulting product was cooled to room temperature. Then, 2 parts of sodium lauryl sulfate, 3 parts of fatty alcohol polyoxyethylene ether and 30 parts of deionized water were added and stirred at high speed to obtain a fluorinated silicone oil-modified acrylate emulsion.

[0047] Comparative Preparation Example 2

[0048] Preparation of fluorinated silicone oil modified acrylate emulsion:

[0049] 2 parts of ammonium persulfate and 35 parts of acetone were added to a reaction vessel and stirred to completely dissolve the ammonium persulfate. Then, 40 parts of methyl methacrylate, 12 parts of isooctyl acrylate, 6-hydroxyethyl acrylate and 18 parts of fluorinated silicone oil were added and stirred evenly. The temperature was raised to 75°C and refluxed for 3 hours. After the reaction was completed, the resulting product was cooled to room temperature. Then, 2 parts of sodium lauryl sulfate, 3 parts of fatty alcohol polyoxyethylene ether and 30 parts of deionized water were added and stirred at high speed to obtain a fluorinated silicone oil-modified acrylate emulsion.

[0050] Comparative Preparation Example 3

[0051] Preparation of acrylic emulsion:

[0052] 2 parts of ammonium persulfate and 35 parts of acetone were added to a reaction vessel and stirred to completely dissolve the ammonium persulfate. Then, 40 parts of methyl methacrylate, 12 parts of isooctyl acrylate and 6-hydroxyethyl acrylate were added and stirred evenly. The temperature was raised to 75°C and refluxed for 3 hours. After the reaction was completed, the resulting product was cooled to room temperature. Then, 2 parts of sodium lauryl sulfate, 3 parts of fatty alcohol polyoxyethylene ether and 30 parts of deionized water were added and stirred at high speed to obtain a fluorine-containing silicone oil-modified acrylate emulsion.

[0053] Preparation Example 4

[0054] The preparation process of modified hollow glass microspheres is as follows:

[0055] 15 g of 40 μm hollow glass microspheres were added to 300 ml of a 5 wt% sodium hydroxide aqueous solution and stirred at room temperature for 3 h. The hollow glass microspheres were filtered out and washed four times with deionized water until the pH value of the washing solution was in the range of 6 to 8. The obtained hollow glass microspheres were then vacuum dried at 60°C for 8 h.

[0056] Preparation Example 5

[0057] The preparation process of modified mica powder is as follows:

[0058] 10 g of flaky mica powder with a particle size of 10 μm was added to 200 ml of a 7 wt% sodium hydroxide aqueous solution, stirred at room temperature for 5 h, and the mica powder was filtered out and washed with deionized water 5 times until the pH value of the washing solution was in the range of 6 to 8. The obtained mica powder was then vacuum dried at 70°C for 6 h.

[0059] Example 1

[0060] A hydrophobic brightening coating composition for tunnels comprises the following components, in parts by weight: 45 parts of the fluorine-containing silicone oil-modified acrylate emulsion obtained in Preparation Example 1, 15 parts of the modified hollow glass microspheres obtained in Preparation Example 4, 8 parts of the modified mica powder obtained in Preparation Example 5, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, 2 parts of BYK-024, and 1 part of PUR40.

[0061] The preparation process of the hydrophobic brightening coating composition for tunnels is as follows:

[0062] 45 parts of the fluorinated silicone oil-modified acrylate emulsion obtained in Preparation Example 1, 15 parts of the modified hollow glass microspheres obtained in Preparation Example 4, and 8 parts of the modified mica powder obtained in Preparation Example 5 were stirred and mixed for 2 hours to obtain a mixed solution; 2 parts of BYK-024, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, and 1 part of PUR40 were added to the above mixed solution and stirred evenly to obtain a hydrophobic brightening coating composition for tunnels.

[0063] Example 2

[0064] A hydrophobic brightening coating composition for tunnels comprises the following components, in parts by weight: 45 parts of the fluorine-containing silicone oil-modified acrylate emulsion obtained in Preparation Example 2, 18 parts of the modified hollow glass microspheres obtained in Preparation Example 4, 6 parts of the modified mica powder obtained in Preparation Example 5, 4 parts of rutile titanium dioxide, 2 parts of sodium lauryl sulfate, 3 parts of BYK-024, and 2 parts of PUR40.

[0065] The preparation process of the hydrophobic brightening coating composition for tunnels is as follows:

[0066] 45 parts of the fluorine-containing silicone oil-modified acrylate emulsion obtained in Preparation Example 2, 18 parts of the modified hollow glass microspheres obtained in Preparation Example 4, and 6 parts of the modified mica powder obtained in Preparation Example 5 were stirred and mixed for 3 hours to obtain a mixed solution; 3 parts of BYK-024, 4 parts of rutile titanium dioxide, 2 parts of sodium lauryl sulfate, and 2 parts of PUR40 were added to the above mixed solution and stirred evenly to obtain a hydrophobic brightening coating composition for tunnels.

[0067] Example 3

[0068] A hydrophobic brightening coating composition for tunnels comprises the following components, in parts by weight: 45 parts of the fluorine-containing silicone oil-modified acrylate emulsion obtained in Preparation Example 3, 20 parts of the modified hollow glass microspheres obtained in Preparation Example 4, 8 parts of the modified mica powder obtained in Preparation Example 5, 3 parts of rutile titanium dioxide, 2 parts of sodium lauryl sulfate, 3 parts of BYK-024, and 2 parts of PUR40.

[0069] The preparation process of the hydrophobic brightening coating composition for tunnels is as follows:

[0070] 45 parts of the fluorine-containing silicone oil-modified acrylate emulsion obtained in Preparation Example 3, 20 parts of the modified hollow glass microspheres obtained in Preparation Example 4, and 8 parts of the modified mica powder obtained in Preparation Example 5 were stirred and mixed for 3 hours to obtain a mixed solution; 3 parts of BYK-024, 3 parts of rutile titanium dioxide, 2 parts of sodium lauryl sulfate, and 2 parts of PUR40 were added to the above mixed solution and stirred evenly to obtain a hydrophobic brightening coating composition for tunnels.

[0071] Comparative Example 1

[0072] A hydrophobic brightening coating composition for tunnels comprises the following components, in parts by weight: 45 parts of the fluorine-containing silicone oil-modified acrylate emulsion obtained in Comparative Preparation Example 1, 15 parts of the modified hollow glass microspheres obtained in Preparation Example 4, 8 parts of the modified mica powder obtained in Preparation Example 5, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, 2 parts of BYK-024, and 1 part of PUR40.

[0073] The preparation process of the hydrophobic brightening coating composition for tunnels is as follows:

[0074] 45 parts of the fluorinated silicone oil-modified acrylate emulsion obtained in Comparative Preparation Example 1, 15 parts of the modified hollow glass microspheres obtained in Preparation Example 4, and 8 parts of the modified mica powder obtained in Preparation Example 5 were stirred and mixed for 2 hours to obtain a mixed solution; 2 parts of BYK-024, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, and 1 part of PUR40 were added to the above mixed solution and stirred evenly to obtain a hydrophobic brightening coating composition for tunnels.

[0075] Comparative Example 2

[0076] A hydrophobic brightening coating composition for tunnels comprises the following components, in parts by weight: 45 parts of the fluorine-containing silicone oil-modified acrylate emulsion obtained in Comparative Preparation Example 2, 15 parts of the modified hollow glass microspheres obtained in Preparation Example 4, 8 parts of the modified mica powder obtained in Preparation Example 5, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, 2 parts of BYK-024, and 1 part of PUR40.

[0077] The preparation process of the hydrophobic brightening coating composition for tunnels is as follows:

[0078] 45 parts of the fluorinated silicone oil-modified acrylate emulsion obtained in Comparative Preparation Example 2, 15 parts of the modified hollow glass microspheres obtained in Preparation Example 4, and 8 parts of the modified mica powder obtained in Preparation Example 5 were stirred and mixed for 2 hours to obtain a mixed solution; 2 parts of BYK-024, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, and 1 part of PUR40 were added to the above mixed solution and stirred evenly to obtain a hydrophobic brightening coating composition for tunnels.

[0079] Comparative Example 3

[0080] A hydrophobic brightening coating composition for tunnels comprises the following components, in parts by weight: 45 parts of the acrylic emulsion obtained in Comparative Preparation Example 3, 15 parts of the modified hollow glass microspheres obtained in Preparation Example 4, 8 parts of the modified mica powder obtained in Preparation Example 5, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, 2 parts of BYK-024, and 1 part of PUR40.

[0081] The preparation process of the hydrophobic brightening coating composition for tunnels is as follows:

[0082] 45 parts of the acrylic emulsion obtained in Comparative Preparation Example 3, 15 parts of the modified hollow glass microspheres obtained in Preparation Example 4, and 8 parts of the modified mica powder obtained in Preparation Example 5 were stirred and mixed for 2 hours to obtain a mixed solution; 2 parts of BYK-024, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, and 1 part of PUR40 were added to the above mixed solution and stirred evenly to obtain a hydrophobic brightening coating composition for tunnels.

[0083] Comparative Example 4

[0084] A hydrophobic brightening coating composition for tunnels comprises the following components, in parts by weight: 45 parts of the fluorine-containing silicone oil-modified acrylate emulsion obtained in Preparation Example 1, 15 parts of unmodified hollow glass microspheres used in Preparation Example 4, 8 parts of unmodified mica powder used in Preparation Example 5, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, 2 parts of BYK-024, and 1 part of PUR40.

[0085] The preparation process of the hydrophobic brightening coating composition for tunnels is as follows:

[0086] 45 parts of the fluorinated silicone oil-modified acrylate emulsion obtained in Comparative Preparation Example 1, 15 parts of the unmodified hollow glass microspheres used in Preparation Example 4, and 8 parts of the unmodified mica powder used in Preparation Example 5 were stirred and mixed for 2 hours to obtain a mixed solution; 2 parts of BYK-024, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, and 1 part of PUR40 were added to the above mixed solution and stirred evenly to obtain a hydrophobic brightening coating composition for tunnels.

[0087] Substrate treatment

[0088] Clean the surface of the substrate tinplate, remove the old paint film, rust, oil, oxide scale and debris on the surface, and ensure that the substrate surface is free of rust, oil, dust and water marks.

[0089] The hydrophobic brightening coating compositions for tunnels of Examples 1-3 and Comparative Examples 1-4 were applied to a clean tinplate surface with a thickness of 100 μm and dried at 40-50° C. for 8 h to obtain a hydrophobic brightening coating.

[0090] Performance Testing

[0091] 1. Adhesion test: Grid method, adhesion test is carried out in accordance with GB / T9286-2021.

[0092] 2. Hydrophobicity test: Water contact angle test is conducted according to GB / T 30693-2014.

[0093] 3. Durability test: Conduct artificial climate aging test according to GB / T 23987-2009.

[0094] 4. Salt spray resistance test: Neutral salt spray resistance test is carried out in accordance with GB / T 1771-2007.

[0095] 5. Retroreflective luminance coefficient (mcd / (m2.lx): tested in accordance with GB / T16322-2009.

[0096] Table 1 Test results of hydrophobic brightening coating compositions for tunnels obtained from various examples and comparative examples

[0097]

[0098] As can be seen from the experimental results in Table 1, by comparing Example 1 with Comparative Examples 1-2, it can be seen that by adding a limited amount of fluorinated silicone oil, the adhesion of the resulting hydrophobic brightening coating composition is significantly improved. A larger amount of fluorinated silicone oil is more detrimental to the improvement in adhesion than a smaller amount. A comparison of Example 1 with Comparative Examples 3-4 shows that the coating composition with the addition of fluorinated silicone oil has improved adhesion compared to the solution without the addition of fluorinated silicone oil, and the solution with the addition of fluorinated silicone oil but without modification of the hollow glass microspheres and mica powder.

[0099] In addition, by comparing Examples 1-3 with Comparative Examples 1-4, it can be seen that the coating composition to which a limited amount of fluorinated silicone oil is added has obvious improvements in hydrophobicity, durability, salt spray resistance and reflectivity.

[0100] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the defined scope, they should all fall within the scope of protection of the present invention.

Claims

1. A hydrophobic brightening coating composition for tunnels, characterized in that: The invention comprises the following components by weight: 45 parts of fluorinated silicone oil-modified acrylate emulsion, 15-30 parts of modified hollow glass microspheres, 5-10 parts of modified mica powder, 3-5 parts of titanium dioxide, 2-5 parts of wetting agent, 2-6 parts of defoaming agent, and 1-5 parts of thickener. The modified hollow glass microspheres are surface-hydroxylated hollow glass microspheres, and the modified mica powder is surface-hydroxylated mica powder. The fluorinated silicone oil-modified acrylate emulsion is prepared from 40 parts of methyl methacrylate, 10-20 parts of isooctyl acrylate, 5-10 parts of hydroxyethyl acrylate, 8-15 parts of fluorinated silicone oil, 30-40 parts of acetone, 1-5 parts of anionic emulsifier, 2-6 parts of nonionic emulsifier, 1-4 parts of initiator, and 20-40 parts of deionized water. The structural formula of the fluorinated silicone oil is as follows:

2. A hydrophobic brightening coating composition for tunnels according to claim 1, characterized in that: The particle size of the hollow glass microspheres is 40-80 microns. The modification process of the modified hollow glass microspheres is as follows: a certain mass of hollow glass microspheres is added to a sodium hydroxide solution of a certain concentration, stirred at room temperature for 2-3 hours, filtered out the hollow glass microspheres, washed with deionized water for 3-5 times until the pH value of the washing solution is within the range of 6-8, and then the obtained hollow glass microspheres are vacuum dried at 60-80°C for 6-8 hours.

3. A hydrophobic brightening coating composition for tunnels according to claim 1, characterized in that: The modified mica powder is in the form of flakes, and the particle size of the modified mica powder is 5-15 μm. The modification process of the modified mica powder is as follows: a certain mass of mica powder is added to a sodium hydroxide solution of a certain concentration, stirred at room temperature for 3-5 hours, filtered to remove the mica powder, washed with deionized water for 2-5 times until the pH value of the washing solution is within the range of 6-8, and then the obtained mica powder is vacuum dried at 60-80° C. for 6-8 hours.

4. A hydrophobic brightening coating composition for tunnels according to claim 1, characterized in that: The wetting agent is one or a combination of two or more of sodium dodecylbenzene sulfonate, sodium lauryl sulfate, and sodium stearate.

5. The hydrophobic brightening coating composition for tunnels according to claim 1, characterized in that: The defoaming agent is one of BYK-024, BYK-028, and OS-5201, or a combination of two or more thereof.

6. The hydrophobic brightening coating composition for tunnels according to claim 1, wherein: The thickener is one of PUR40, PUR41, and ASE-60, or a combination of two or more thereof.

7. The hydrophobic brightening coating composition for tunnels according to claim 1, characterized in that: The preparation process of the fluorinated silicone oil-modified acrylate emulsion is as follows: 1-4 parts of an initiator and 30-40 parts of acetone are added to a reaction container, stirred to completely dissolve the initiator, then 40 parts of methyl methacrylate, 10-20 parts of isooctyl acrylate, 5-10 parts of hydroxyethyl acrylate and 8-15 parts of fluorinated silicone oil are added, stirred evenly, the temperature is raised to 70-85° C., refluxed for 2-3 hours, and after the reaction is completed, the resulting product is cooled to room temperature, then 1-5 parts of anionic emulsifier, 2-6 parts of nonionic emulsifier and 20-40 parts of deionized water are added and mixed at high speed with stirring to obtain the fluorinated silicone oil-modified acrylate emulsion.

8. The method for preparing a hydrophobic brightening coating composition for tunnels according to any one of claims 1 to 7, wherein: 45 parts of fluorine-containing silicone oil-modified acrylic emulsion, 15-30 parts of modified hollow glass microspheres, and 5-10 parts of modified mica powder are stirred and mixed for 2-3 hours to obtain a mixed solution; 2-6 parts of a defoamer, 3-5 parts of titanium dioxide, 2-5 parts of a wetting agent, and 1-5 parts of a thickener are added to the above mixed solution and stirred evenly to obtain the hydrophobic brightening coating composition for tunnels.

Images