Hydrophobic brightening coating composition for tunnel and preparation method of hydrophobic brightening coating composition

Abstract

The invention relates to a hydrophobic brightening coating composition for a tunnel and a preparation method of the hydrophobic brightening coating composition. According to the present invention, the acrylate resin emulsion is adopted as the resin matrix, the fluorine-containing silicone oil is added to modify the acrylate resin emulsion so as to improve the hydrophobicity, and in addition, the modified hollow glass beads are added, and the modified mica powder is matched so as to improve the light reflection performance. Meanwhile, active groups of the modified hollow glass beads and the modified mica powder are bonded with active groups in the fluorine-containing silicone oil modified acrylate emulsion, so that the durability of the hydrophobic brightening coating composition is further improved. The obtained hydrophobic brightening coating has good water resistance, light reflection and durability.

Description

Technical Field

[0001] The 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 highway construction in my country, the mileage of highway tunnels has also shown a relatively rapid development trend. The average annual increase in the mileage of highway tunnels exceeds 1,000 kilometers. Driving in tunnels needs to meet the requirements of safety, comfort and energy saving. The existing highway tunnel lighting quality evaluation index system consists of indicators such as contrast display coefficient qc, 2m high wall brightness on both sides of the tunnel, middle section road brightness uniformity and road centerline brightness longitudinal uniformity, and lamp arrangement flicker frequency, which directly determines whether the tunnel lighting can meet the requirements of safety, comfort and energy saving.

[0003] The wall material in the tunnel will affect the parameters of the tunnel lighting quality evaluation index system. The decoration materials in the tunnel can be roughly divided into 6 categories: concrete (i.e., keeping the original color of concrete, without decoration), paint, facing brick (ceramic tile), fiber concrete board with coating (such as Vitra board, Kaso board), composite aluminum board (such as fluorocarbon aluminum board, porcelain aluminum board), enameled steel board. Studies have shown that painting the side wall of the tunnel with reflective paint is conducive to improving the lighting environment inside the tunnel and also has a positive effect on tunnel safety rescue.

[0004] Reflective coatings are mainly composed of polymer resin matrix and reflective fillers. Polymer matrix includes acrylic resin, polyurethane resin, epoxy resin, polyester resin, etc. Reflective fillers include glass beads, silver aluminum powder, titanium dioxide, etc. Reflective coatings are based on the principle of retroreflection. They can use the illumination of car lights and the reflection of light to "light up" the front, increase the distance for drivers to find objects in front, and thus give drivers more time to take appropriate safety measures.

[0005] Patent CN105130344A discloses a tunnel fireproof energy-saving reflective coating. The tunnel fireproof energy-saving reflective coating is composed of sulphoaluminate cement, slag powder, filler, fly ash, reflective material and flame retardant. The invention has continuous fireproof properties, has obvious reflective effect on various light sources, has high fireproof properties compared with similar reflective coatings, has better reflective effect compared with similar fireproof coatings, can be widely used in tunnel fireproof energy-saving projects, has no toxic and polluting substances, is easy to construct, and saves energy.

[0006] Patent CN111777888A discloses a self-luminous and reflective coating for the inner wall of a highway tunnel and an application method. The self-luminous and reflective coating for the inner wall of a highway tunnel provided by this method has the following advantages: (1) Energy-saving and environmental protection, it can significantly reduce the energy consumption of highway tunnels on the premise of meeting the tunnel lighting requirements; (2) Low maintenance cost, good weather resistance, strong adhesion, good corrosion resistance, and the durability is 4-5 times that of lighting fixtures; (3) Short drying time, easy to construct, low organic matter content, and environmentally friendly; (4) The composite coating has a large retroreflective coefficient, a long minimum recognition distance, and good reflective effect.

[0007] Patent CN118185355A discloses a preparation process of a reflective coating adhesive with high-strength bonding performance. The preparation process of the reflective coating adhesive with high-strength bonding performance greatly improves the bonding performance of the coating adhesive by adding components such as carboxymethyl cellulose, polyvalerolactone, and diacetone acrylamide to the components of the reflective coating adhesive, and well achieves the purpose of improving the bonding effect of the adhesive by improving the components of the adhesive, avoiding the obvious peeling phenomenon that occurs when the coating is used in harsh outdoor environments due to the use of more water-based components, thus greatly facilitating the long-term use of the reflective coating adhesive.

[0008] However, the reflective coatings in the prior art are extremely easy to get dirty and difficult to clean, resulting in a short service life, and often cannot achieve the reflective effect after being used for a period of time. However, a tunnel is a special highway facility with a small internal space. Therefore, the maintenance and cleaning of the tunnel wall are not convenient. Therefore, there is an urgent need to develop a reflective coating that is dirt-resistant, has a long service life, and a high reflectivity.

[0009] Based on the above problems, the present invention provides a hydrophobic brightening coating composition with good hydrophobicity, not easy to get dirty, good reflectivity, and good durability. The present invention uses an acrylate resin emulsion as the resin matrix, modifies the acrylate resin emulsion by adding fluorosilicone oil to improve its hydrophobicity. In addition, by adding modified hollow glass microspheres and collocating with modified mica powder, its reflective performance is improved. At the same time, the active groups of the modified hollow glass microspheres and the modified mica powder are bonded to the active groups in the fluorosilicone oil-modified acrylate emulsion, further improving the durability of the hydrophobic brightening coating composition. Summary of the Invention

[0010] To solve the above technical problems, the present invention provides a hydrophobic brightening coating composition for tunnels and a preparation method thereof. The obtained hydrophobic brightening coating composition for tunnels has excellent hydrophobicity, reflectivity, and durability. The present invention is realized through the following technical solutions:

[0011] A hydrophobic and brightening coating composition for tunnels, by weight, comprises the following components: 45 parts of fluorosilicone 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, 1 - 5 parts of thickening agent.

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

[0013] Add a certain mass of hollow glass microspheres to a sodium hydroxide solution with a certain concentration, stir at room temperature for 2 - 3 h, filter out the hollow glass microspheres, wash them 3 - 5 times with deionized water until the pH value of the washing liquid is within the range of 6 - 8, and then vacuum-dry the obtained hollow glass microspheres at 60 - 80 °C for 6 - 8 hours;

[0014] Further, the modified mica powder is flaky, and the particle size of the modified mica powder is 5 - 15 μm; the modified mica powder is mica powder with a hydroxylated surface.

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

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

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

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

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

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

[0021] Further, the fluorosilicone oil-modified acrylate emulsion is prepared from 40 parts of methyl methacrylate, 10 - 20 parts of isooctyl acrylate, 5 - 10 parts of 2-hydroxyethyl acrylate, 8 - 15 parts of fluorosilicone 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 fluorosilicone oil is as follows:

[0023]

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

[0025] Add 1 - 4 parts of initiator and 30 - 40 parts of acetone into a reaction vessel, stir to completely dissolve the initiator, then add 40 parts of methyl methacrylate, 10 - 20 parts of isooctyl acrylate, 5 - 10 parts of 2-hydroxyethyl acrylate and 8 - 15 parts of fluorosilicone oil. After stirring evenly, raise the temperature to 70 - 85 °C and reflux for 2 - 3 h. After the reaction is completed, cool the obtained product to room temperature, then add 1 - 5 parts of anionic emulsifier, 2 - 6 parts of nonionic emulsifier, and 20 - 40 parts of deionized water and stir at high speed to mix, thus obtaining the fluorosilicone oil-modified acrylate emulsion.

[0026] Furthermore, the anionic emulsifier is selected from one or a combination of two or more of sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and disodium 1,2-dodecyldiethylether 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] Mix 45 parts of fluorosilicone oil-modified acrylate emulsion, 15 - 30 parts of modified hollow glass microspheres, and 5 - 10 parts of modified mica powder for 2 - 3 h to obtain a mixture; add 2 - 6 parts of defoamer, 3 - 5 parts of titanium dioxide, 2 - 5 parts of wetting agent, and 1 - 5 parts of thickener to the above mixture and stir evenly to obtain the hydrophobic brightening coating composition for tunnels.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] The present invention uses fluorosilicone oil to modify acrylate emulsion to obtain a fluorosilicone oil-modified acrylate emulsion. The fluorosilicone oil has unsaturated double bonds and can participate in the free radical polymerization of acrylate emulsion, enabling the fluorosilicone oil to be embedded in the acrylate polymer chain segment. The fluorosilicone oil has fluorine-containing groups and siloxane chain segments, and the above structures all belong to hydrophobic groups. Using the fluorosilicone oil-modified acrylate emulsion to prepare a hydrophobic brightening coating composition can increase the surface tension of the obtained coating composition and improve the hydrophobicity of the obtained coating composition.

[0032] In this application, hollow glass microspheres and mica powder used are activated to expose hydroxyl groups with high activity on their surfaces. During the preparation of the hydrophobic brightening coating composition, these exposed hydroxyl groups can undergo dehydration condensation reactions with the silanol groups contained in the fluorosilicone oil, improving the binding property 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 reflective powders of two systems. 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. Specific Embodiments

[0034] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. However, those skilled in the art will understand that the following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For the reagents or instruments whose manufacturers are not specified, they are all conventional products that can be obtained through commercial purchase.

[0035] Preparation Example 1

[0036] Preparation of fluorosilicone oil-modified acrylate emulsion:

[0037] Add 2 parts of ammonium persulfate and 35 parts of acetone to a reaction vessel, stir to completely dissolve the ammonium persulfate, then add 40 parts of methyl methacrylate, 12 parts of isooctyl acrylate, 6 parts of 2-hydroxyethyl acrylate and 8 parts of fluorosilicone oil. After stirring evenly, raise the temperature to 75 °C and carry out a reflux reaction for 3 h. After the reaction is completed, cool the obtained product to room temperature, and then add 2 parts of sodium dodecyl sulfate, 3 parts of fatty alcohol polyoxyethylene ether, and 30 parts of deionized water and stir at high speed to mix, thus obtaining the fluorosilicone oil-modified acrylate emulsion.

[0038] Preparation Example 2

[0039] Preparation of fluorosilicone oil-modified acrylate emulsion:

[0040] Add 3 parts of potassium persulfate and 30 parts of acetone into a reaction vessel, stir to completely dissolve potassium persulfate, then add 40 parts of methyl methacrylate, 14 parts of isooctyl acrylate, 5 parts of 2-hydroxyethyl acrylate and 12 parts of fluorosilicone oil. After stirring evenly, raise the temperature to 70 °C and carry out a reflux reaction for 3 h. After the reaction is completed, cool the obtained product to room temperature, then add 1 part of sodium dodecyl sulfate, 4 parts of fatty alcohol polyoxyethylene ether and 35 parts of deionized water, and stir at high speed to mix them evenly, thus obtaining the fluorosilicone oil-modified acrylate emulsion.

[0041] Preparation Example 3

[0042] Preparation of fluorosilicone oil-modified acrylate emulsion:

[0043] Add 2 parts of potassium persulfate and 35 parts of acetone into a reaction vessel, stir to completely dissolve potassium persulfate, then add 40 parts of methyl methacrylate, 15 parts of isooctyl acrylate, 5 parts of 2-hydroxyethyl acrylate and 15 parts of fluorosilicone oil. After stirring evenly, raise the temperature to 75 °C and carry out a reflux reaction for 2 h. After the reaction is completed, cool the obtained product to room temperature, then add 1 part of sodium dodecylbenzenesulfonate, 4 parts of fatty alcohol polyoxyethylene ether and 35 parts of deionized water, and stir at high speed to mix them evenly, thus obtaining the fluorosilicone oil-modified acrylate emulsion.

[0044] Comparative Preparation Example 1

[0045] Preparation of fluorosilicone oil-modified acrylate emulsion:

[0046] Add 2 parts of ammonium persulfate and 35 parts of acetone into a reaction vessel, stir to completely dissolve ammonium persulfate, then add 40 parts of methyl methacrylate, 12 parts of isooctyl acrylate, 6 parts of 2-hydroxyethyl acrylate and 6 parts of fluorosilicone oil. After stirring evenly, raise the temperature to 75 °C and carry out a reflux reaction for 3 h. After the reaction is completed, cool the obtained product to room temperature, then add 2 parts of sodium dodecyl sulfate, 3 parts of fatty alcohol polyoxyethylene ether and 30 parts of deionized water, and stir at high speed to mix them evenly, thus obtaining the fluorosilicone oil-modified acrylate emulsion.

[0047] Comparative Preparation Example 2

[0048] Preparation of fluorosilicone oil-modified acrylate emulsion:

[0049] Add 2 parts of ammonium persulfate and 35 parts of acetone into a reaction vessel, stir to completely dissolve ammonium persulfate, then add 40 parts of methyl methacrylate, 12 parts of isooctyl acrylate, 6 parts of 2-hydroxyethyl acrylate and 18 parts of fluorosilicone oil. After stirring evenly, raise the temperature to 75 °C and carry out a reflux reaction for 3 h. After the reaction is completed, cool the obtained product to room temperature, then add 2 parts of sodium dodecyl sulfate, 3 parts of fatty alcohol polyoxyethylene ether and 30 parts of deionized water, and stir at high speed to mix them evenly, thus obtaining the fluorosilicone oil-modified acrylate emulsion.

[0050] Comparative Preparation Example 3

[0051] Preparation of acrylate emulsion:

[0052] Add 2 parts of ammonium persulfate and 35 parts of acetone to a reaction vessel, stir to completely dissolve the ammonium persulfate, then add 40 parts of methyl methacrylate, 12 parts of isooctyl acrylate, and 6 parts of 2-hydroxyethyl acrylate. After stirring evenly, raise the temperature to 75 °C and reflux for 3 h. After the reaction is completed, cool the obtained product to room temperature, then add 2 parts of sodium dodecyl sulfate, 3 parts of fatty alcohol polyoxyethylene ether, and 30 parts of deionized water, and stir at high speed to mix, thus obtaining a fluorosilicone oil-modified acrylate emulsion.

[0053] Preparation Example 4

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

[0055] Add 15 g of hollow glass microspheres with a particle size of 40 μm to 300 ml of a sodium hydroxide aqueous solution with a mass fraction of 5 wt%, stir at room temperature for 3 h, filter out the hollow glass microspheres, wash them 4 times with deionized water until the pH value of the washing liquid is in the range of 6 - 8, and then vacuum-dry the obtained hollow glass microspheres at 60 °C for 8 hours;

[0056] Preparation Example 5

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

[0058] Add 10 g of flaky mica powder with a particle size of 10 μm to 200 ml of a sodium hydroxide aqueous solution with a mass fraction of 7 wt%, stir at room temperature for 5 h, filter out the mica powder, wash it 5 times with deionized water until the pH value of the washing liquid is in the range of 6 - 8, and then vacuum-dry the obtained mica powder at 70 °C for 6 hours;

[0059] Example 1

[0060] A hydrophobic brightening coating composition for tunnels, by weight, comprises the following components: 45 parts of the fluorosilicone 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] Mix 45 parts of the fluorosilicone 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 for 2 h to obtain a mixed liquid; add 2 parts of BYK-024, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, and 1 part of PUR40 to the above mixed liquid, and stir evenly to obtain a hydrophobic brightening coating composition for tunnels.

[0063] Example 2

[0064] A hydrophobic brightening coating composition for tunnels, by weight, comprises the following components: 45 parts of the fluorosilicone 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 dodecyl 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] Mix 45 parts of the fluorosilicone 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 for 3 h to obtain a mixed liquid; add 3 parts of BYK-024, 4 parts of rutile titanium dioxide, 2 parts of sodium dodecyl sulfate, and 2 parts of PUR40 to the above mixed liquid, and stir evenly to obtain a hydrophobic brightening coating composition for tunnels.

[0067] Example 3

[0068] A hydrophobic brightening coating composition for tunnels, by weight, comprises the following components: 45 parts of the fluorosilicone 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 dodecyl 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] Mix 45 parts of the fluorosilicone 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 for 3 h to obtain a mixed liquid; add 3 parts of BYK-024, 3 parts of rutile titanium dioxide, 2 parts of sodium dodecyl sulfate, and 2 parts of PUR40 to the above mixed liquid, and stir evenly to obtain a hydrophobic brightening coating composition for tunnels.

[0071] Comparative Example 1

[0072] A hydrophobic and brightening coating composition for tunnels, by weight, comprises the following components: 45 parts of the fluorosilicone 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 and brightening coating composition for tunnels is as follows:

[0074] Mix 45 parts of the fluorosilicone 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 by stirring for 2 h to obtain a mixed solution; add 2 parts of BYK-024, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, and 1 part of PUR40 to the above mixed solution, and stir evenly to obtain the hydrophobic and brightening coating composition for tunnels.

[0075] Comparative Example 2

[0076] A hydrophobic and brightening coating composition for tunnels, by weight, comprises the following components: 45 parts of the fluorosilicone 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 and brightening coating composition for tunnels is as follows:

[0078] Mix 45 parts of the fluorosilicone 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 by stirring for 2 h to obtain a mixed solution; add 2 parts of BYK-024, 3 parts of rutile titanium dioxide, 3 parts of sodium dodecylbenzenesulfonate, and 1 part of PUR40 to the above mixed solution, and stir evenly to obtain the hydrophobic and brightening coating composition for tunnels.

[0079] Comparative Example 3

[0080] A hydrophobic and brightening coating composition for tunnels, by weight, comprises the following components: 45 parts of the acrylate 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 and 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 dodecylbenzene sulfonate, 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 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 dodecylbenzene sulfonate, 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 acrylic 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 dodecylbenzene sulfonate, 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 remaining 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 carried out 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: Conduct neutral salt spray resistance test according to GB / T 1771-2007.

[0095] 5. Retroreflective brightness coefficient (mcd / (m2·lx)): Tested according to GB / T 16322-2009.

[0096] Table 1 Test results of hydrophobic brightening coating compositions for tunnels obtained in each example and comparative example

[0097]

[0098] 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 fluorosilicone oil, the adhesion of the obtained hydrophobic brightening coating composition is significantly improved. If the amount of fluorosilicone oil is relatively large, it is more unfavorable for the improvement of adhesion compared to a smaller amount. By comparing Example 1 with Comparative Examples 3-4, it shows that the coating composition added with fluorosilicone oil has improved adhesion compared to the technical solutions without adding fluorosilicone oil and those with added fluorosilicone oil but unmodified 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 added with a limited amount of fluorosilicone oil has obvious improvements in hydrophobicity, durability, salt spray resistance, and reflectivity.

[0100] The above content is only an example and explanation of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods to replace them. As long as they do not deviate from the concept of the invention or exceed the defined scope, they should fall within the protection scope 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 fluorine-containing silicone oil modified acrylic 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 hollow glass microspheres with hydroxylation on the surface, and the modified mica powder is mica powder with hydroxylation on the surface.

2. A hydrophobic brightening coating composition for tunnels as claimed in 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: adding a certain mass of hollow glass microspheres to a sodium hydroxide solution of a certain concentration, stirring at room temperature for 2-3 hours, filtering out the hollow glass microspheres, washing them with deionized water for 3-5 times until the pH value of the washing solution is in the range of 6-8, and then vacuum drying the obtained hollow glass microspheres at 60-80°C for 6-8 hours.

3. A hydrophobic brightening coating composition for tunnels as claimed in 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 out 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 as claimed in claim 1, characterized in that: The wetting agent is one or a combination of two or more of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate and sodium stearate.

5. A hydrophobic brightening coating composition for tunnels as claimed in 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. A hydrophobic brightening coating composition for tunnels as claimed in claim 1, characterized in that: The thickener is one of PUR40, PUR41, ASE-60 or a combination of two or more thereof.

7. A hydrophobic brightening coating composition for tunnels as claimed in claim 1, characterized in that: The fluorinated silicone oil-modified acrylic 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.

8. A hydrophobic brightening coating composition for tunnels as claimed in claim 7, characterized in that: The structural formula of the fluorine-containing silicone oil is as follows:

9. A hydrophobic brightening coating composition for tunnels as claimed in claim 7, 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 into 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 increased to 70-85°C, refluxed for 2-3h, after the reaction is completed, the obtained 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, stirred and mixed at high speed to obtain the fluorinated silicone oil modified acrylate emulsion.

10. A method for preparing a hydrophobic brightening coating composition for tunnels according to any one of claims 1 to 9, characterized in that: 45 parts of fluorinated 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 mixed solution, and stirred evenly to obtain the hydrophobic brightening coating composition for tunnels.

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