Silica sol and its preparation method and glass and its preparation method

Abstract

This invention provides a silica sol and its preparation method, as well as a glass and its preparation method. The silica sol's raw materials include a complex alkoxysilane in a mass ratio of 30-40:1-5:45-60:1-5:0.01-0.1:8-13, a silane coupling agent, an organic solvent, an additive, a catalyst, and water. The complex alkoxysilane includes a first alkoxysilane and a second alkoxysilane in a mass ratio of 1:6-6:1. The first alkoxysilane has the structural formula: Si(OR) 1 )4, R 1 It is an alkyl group; the structural formula of the second alkoxysilane is R. 2 n Si(OR 3 ) 4‑n n is 1 or 2, R 2 R is a non-hydrolyzable organic functional group. 3 The silica sol is alkyl. The above-mentioned silica sol can withstand the high-temperature curing process, simplifying the preparation process of coated glass. The coating formed by silica sol has high hardness, high temperature resistance, wear resistance, and aging resistance.

Description

Technical Field

[0001] This invention relates to the field of functional coating preparation technology, and in particular to a silica sol and its preparation method and a glass and its preparation method. Background Technology

[0002] Currently, automotive glass coating products, such as coatings that block ultraviolet light, prevent blue light, absorb infrared light, prevent fog, and are hydrophobic, are generally cured under conditions of 100℃-200℃ (e.g., 190℃ for 30 minutes). Excessively high temperatures will greatly affect the application effect of the coating.

[0003] The bending process of automotive glass requires exposure to high temperatures (550℃-750℃), but existing coatings used on glass are unable to withstand such high temperatures.

[0004] Existing high-temperature resistant coating technologies, such as the Chinese patent CN103467074A which discloses a method for preparing a high-temperature resistant coating, include the following steps: (1) preparing mixed borosilicate glass powder by high-temperature melting; (2) preparing filler by high-temperature melting; (3) mixing additives; (4) preparing a high-temperature resistant slurry by grinding; and (5) preparing a high-temperature resistant coating by high-temperature curing. The coating of this invention has good high-temperature resistance and can be used for a long time below 1200℃. It also has low expansion performance and high radiation performance. However, this technology has the following problems: (1) the raw materials contain expensive components, which increases the cost; (2) the coating slurry preparation process requires high-temperature melting and other processes, which increases the complexity of the process and the production cost; (3) after the slurry is coated on the substrate surface, it is sintered at a high temperature of 800-1250℃ to obtain a high-temperature resistant coating. This sintering temperature is too high for automotive glass.

[0005] Therefore, there is a need to provide a glass coating that can withstand the high-temperature curing process. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a silica sol and its preparation method, as well as a glass and its preparation method. The silica sol provided by the present invention can withstand high-temperature curing processes and form a coating. The coating curing process can be carried out simultaneously with the glass bending and forming process, saving the need for a separate high-temperature curing step and simplifying the process.

[0007] To achieve the above objectives, the present invention provides a silica sol, the raw materials of which include a composite alkoxysilane, a silane coupling agent, an organic solvent, an auxiliary agent, a catalyst, and water in a mass ratio of 30-40:1-5:45-60:1-5:0.01-0.1:8-13; wherein the composite alkoxysilane comprises a first alkoxysilane and a second alkoxysilane in a mass ratio of 1:6-6:1; wherein the first alkoxysilane has the structural formula: Si(OR 1 )4, R1 It is an alkyl group; the structural formula of the second alkoxysilane is: R 2 n Si(OR 3 ) 4-n n is 1 or 2, R 2 R is a non-hydrolyzable organic functional group. 3 For alkyl.

[0008] In the aforementioned silica sol, the structural formula of the first alkoxysilane is Si(OR) 1 In )4, R 1 It is an alkyl group, and the number of carbon atoms in an alkyl group can be less than or equal to 3. Specifically, R 1 It is selected from one or more combinations of methyl, ethyl, and propyl. In some specific embodiments, the first alkoxysilane may specifically include tetramethyl orthosilicate and / or tetraethyl orthosilicate, etc.

[0009] In the aforementioned silica sol, the structural formula R of the dialkoxysilane is... 2 n Si(OR 3 ) 4-n In the middle, R 2 For non-hydrolyzable organic functional groups, further, R 2 Including alkyl and / or phenyl; furthermore, R 2 It may include phenyl groups and / or alkyl groups having 2 or fewer carbon atoms, for example, the R 2 It is selected from one or more combinations of methyl, ethyl, and phenyl.

[0010] In the aforementioned silica sol, the structural formula R of the dialkoxysilane is... 2 n Si(OR 3 ) 4-n In the middle, R 3 It can be an alkyl group, for example, an alkyl group with 3 or fewer carbon atoms. R 3 It can be selected from one or more combinations of methyl, ethyl and propyl.

[0011] In some specific embodiments, the second alkoxysilane may include one or more combinations of methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane.

[0012] In the aforementioned silica sol, the R in the structural formula of the first alkoxysilane... 1 R in the structural formula of dialkoxysilane 3 They can be the same or different.

[0013] In composite silica sols, the content of hydrolyzable groups in the first alkoxysilane is higher than that in the second alkoxysilane. This invention has found that when the proportion of the first alkoxysilane in the total alkoxysilane is too high, the hydrolysis reaction rate is too fast, resulting in an excessive number of hydroxyl groups in the generated molecular chains, which affects the weather resistance of the cured silica sol coating. Conversely, when the proportion of the first alkoxysilane in the composite alkoxysilane is too low, the hydrolysis reaction rate is too slow, resulting in too few hydroxyl groups in the generated molecular chains, which reduces the adhesion between the coating and the glass substrate. This invention, by controlling the ratio of the first to the second alkoxysilane, can ensure that the silica sol molecules generated in the reaction have a suitable molecular structure and hydroxyl group distribution, thereby improving the adhesion between the silica sol-formed coating and the glass substrate, and enabling the silica sol-formed coating to possess both high weather resistance and mechanical properties (such as abrasion resistance). The mass ratio of the silicate ester to the substituted alkoxysilane is generally controlled to be 1:6-6:1, for example, specific values ​​such as 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 8:7, 2:1, 3:1, 4:1, 5:1, 6:1, etc., and a range with any two of the above specific values ​​as endpoints.

[0014] In the aforementioned silica sol, the addition of a silane coupling agent improves the adhesion of the coating to the glass substrate surface while reducing surface roughness and making the coating surface smoother. The silane coupling agent includes γ-glycidoxypropyltrimethoxysilane (KH560) and / or γ-methacryloyloxypropyltrimethoxysilane (KH570). In some specific embodiments, the mass ratio of the silane coupling agent to the composite alkoxysilane can be controlled to 1-5:30-40, for example, specific values ​​such as 1:40, 1:35, 2:35, 5:30, etc., and a range with any two of the above specific values ​​as endpoints.

[0015] In the aforementioned silica sol, the organic solvent provides a sol-gel reaction system for the formation of the silica sol, and the evaporation of the organic solvent allows the silica sol to form a coating. The organic solvent includes ethanol and / or isopropanol. In some specific embodiments, the mass ratio of the organic solvent to the complex alkoxysilane can be controlled to be 45-60:30-40, for example, specific values ​​such as 45:40, 49:35, 49.1:35, 49:30, 60:30, etc., and a range with any two of the above specific values ​​as endpoints.

[0016] In the aforementioned silica sol, the additive can regulate the evaporation rate of the organic solvent, adjust the coating formation process, and promote coating formation. The additive includes propylene glycol methyl ether acetate and / or diethylene glycol ethyl ether. In some specific embodiments, the mass ratio of the additive to the complex alkoxysilane can be controlled to 1-5:30-40, for example, specific values ​​such as 1:40, 1:39, 3:39, 4:30, 5:30, etc., and a range with any two of the above specific values ​​as endpoints.

[0017] In the aforementioned silica sol, the catalyst includes an acidic catalyst, such as an inorganic acid. During the reaction to form the silica sol, under the action of the acidic catalyst, the raw materials in the silica sol first generate a linear polymer through a sol-gel reaction, and then further generate a network structure through a cross-linking reaction, resulting in a silica sol with excellent wear resistance. Compared with alkaline catalysts, coatings made from silica sol prepared with acidic catalysts have higher wear resistance.

[0018] This invention has found that excessive catalyst dosage leads to an excessive increase in Si-OH bonds formed by the hydrolysis of complex alkoxysilanes, resulting in particle agglomerates. The condensation process tends to occur within the particles rather than between them, leading to a decrease in coating density. This invention controls the hydrolysis and condensation rate by adjusting the amount of catalyst relative to the complex alkoxysilane, thus obtaining a dense silica sol film. Further high-temperature curing of the silica sol allows it to form a coating, increasing structural density and improving the coating's wear resistance and other mechanical properties.

[0019] In the above-mentioned silica sol, the mass ratio of the catalyst to the composite alkoxysilane is generally controlled to be 0.01-0.1:30-40, for example, it can be a specific value such as 0.01:40, 0.05:35, 0.05:30, 0.1:35, 0.1:30, etc., and a range with any two of the above specific values ​​as endpoints.

[0020] In some specific implementations, the mass ratio of water to the complex alkoxysilane can be controlled to be 8-13:30-40, for example, specific values ​​such as 8:40, 12:39, 13:39, 12:30, 13:30, etc., and a range with any two of the above specific values ​​as endpoints.

[0021] In the aforementioned silica sol, the catalyst may specifically include hydrochloric acid and / or nitric acid.

[0022] The present invention also provides a method for preparing the above-mentioned silica sol, the method comprising:

[0023] A solution A is obtained by mixing a composite alkoxysilane, a silane coupling agent, an organic solvent, and an auxiliary agent.

[0024] The catalyst and water were mixed to obtain solution B;

[0025] Solution A and solution B are mixed and reacted to obtain the silica sol solution.

[0026] In the above preparation method, the obtained silica sol can be an amorphous silica sol.

[0027] The reaction in the above preparation method is a sol-gel reaction, during which the composite alkoxysilane undergoes hydrolysis and condensation. The reaction temperature is 50℃-70℃, such as 50℃, 55℃, 60℃, 65℃, 70℃, etc., and any two of these specific values ​​are endpoints; the reaction time is 4h-6h, such as 4h, 4.5h, 5h, 5.5h, 6h, etc., and any two of these specific values ​​are endpoints. The reaction temperature and reaction time are relatively mild, which can reduce production costs.

[0028] The present invention also provides a glass comprising a glass substrate and a coating applied to the surface of the glass substrate, the coating being formed by curing the aforementioned silica sol.

[0029] In the aforementioned glass, the curing temperature is 550℃-750℃, for example, specific values ​​such as 550℃, 600℃, 650℃, 700℃, 750℃, etc., and a range with any two of the aforementioned specific values ​​as endpoints. The curing time is 5min-10min, for example, specific values ​​such as 5min, 6min, 7min, 8min, 9min, 10min, etc., and a range with any two of the aforementioned specific values ​​as endpoints.

[0030] In the aforementioned glass, the coating is a high-temperature resistant coating, capable of withstanding high-temperature processing at 550℃-750℃, and possesses excellent optical properties, abrasion resistance, and aging resistance. The haze difference before and after the abrasion resistance test can be controlled within 2%, and further controlled within 1.5%. No cracks are observed after the xenon lamp aging test. The test conditions for the abrasion resistance test are as follows: the coating is bonded to the substrate to form the test sample; the haze of the test sample before the test is recorded; the test sample is placed on a plane abrasion tester with the coating facing upwards; the test pressure is 4.5N; a plane abrasion test is performed for 500 revolutions; the haze H1 is obtained by testing the area of ​​the test sample that has not undergone the abrasion resistance test, and the haze H2 is obtained by testing the area that has undergone the abrasion resistance test; the haze difference before and after the test is calculated as H2 - H1.

[0031] In the aforementioned glass, the thickness of the coating can be 100-1000 nm. In some specific embodiments, the thickness of the coating can be 112-560 nm, for example, 112 nm, 336 nm, or 560 nm, and coatings within this thickness range can further have an anti-reflective effect.

[0032] According to a specific embodiment of the present invention, the glass having the above-mentioned coating can have a transmittance of more than 93% for visible light with a wavelength of 380-780nm.

[0033] According to a specific embodiment of the present invention, the haze of the glass having the above-mentioned coating can be controlled to less than 1%, and further controlled to less than 0.5%.

[0034] According to a specific embodiment of the present invention, the reflectance of glass with the above coating to visible light in the 360nm-780nm range can be controlled to below 8%, and further controlled to below 7%.

[0035] In the aforementioned glass, the visible light transmittance of the glass substrate is greater than or equal to 70%. The glass substrate may include one or a combination of two or more of soda-lime glass, aluminosilicate glass, borosilicate glass, and lithium aluminosilicate glass. The type and color of the glass substrate can be selected according to actual application requirements. In some specific embodiments, the glass substrate may include ultra-clear glass, wherein the visible light transmittance of the ultra-clear glass can reach greater than or equal to 90%.

[0036] In the above-mentioned glass, the glass substrate can be a glass substrate with a refractive power of less than or equal to ≤110 mdp, and the glass substrate has excellent optical quality.

[0037] The present invention also provides a method for preparing the above-mentioned glass, which may include: applying a coating to the surface of the glass substrate, and curing the coating to form a coating layer to obtain the glass; wherein the coating comprises the silica sol provided by the present invention.

[0038] In the above preparation method, the coating can be carried out by a film coating method, such as roller coating, spray coating, dip coating, spin coating, etc.

[0039] In the above-mentioned glass preparation method, the curing conditions can be the curing conditions of silica sol, that is, the curing temperature of the coating can be 550℃-750℃, for example, specific values ​​such as 550℃, 600℃, 650℃, 700℃, 750℃, etc., and a range with any two of the above specific values ​​as endpoints; the curing time can be 5min-10min, for example, specific values ​​such as 5min, 6min, 7min, 8min, 9min, 10min, etc., and a range with any two of the above specific values ​​as endpoints.

[0040] In the preparation method of the above-mentioned glass, the coating comprises the above-mentioned silica sol and solvent. The solid content of the coating is 2%-5%. The solid content is the ratio of the mass of the remaining solids after heating the coating at 150°C for 2 hours to the total mass of the coating.

[0041] According to a specific embodiment of the present invention, the above-mentioned glass can be used as automotive glass. Since the coating on the glass surface is heat-resistant, the glass can be called heat-resistant coated automotive glass. The glass provided by the present invention has a heat-resistant coating, which can withstand not only the coating curing process (100℃-200℃) but also the high-temperature treatment process (550℃-750℃) during the bending and forming of automotive glass. Therefore, the glass provided by the present invention can combine the coating curing process and the high-temperature stage of glass bending and forming, allowing them to be carried out simultaneously, saving the separate high-temperature curing step of the coating, simplifying the production process, reducing energy consumption, and having high economic and environmental benefits.

[0042] According to a specific embodiment of the present invention, the method for preparing the glass includes: applying a coating to the surface of a glass substrate, bending the glass substrate, and simultaneously curing the coating to form a coating layer, thereby obtaining the glass.

[0043] The beneficial effects of this invention include:

[0044] 1. The silica sol provided by the present invention has a suitable molecular structure and hydroxyl distribution, which can not only bond firmly to the glass surface, but also has good compatibility with various additives and good weather resistance.

[0045] 2. The silica sol synthesis process provided by this invention is simple, does not require high temperature and high pressure conditions, and has a short reaction time; the synthesis process can achieve continuous production, simplifying the process flow and helping to reduce production costs. The raw materials for this silica sol are inexpensive, which can reduce raw material costs and improve the cost-effectiveness of the silica sol product.

[0046] 3. The silica sol coating provided by this invention has good adhesion to the glass surface, high coating hardness, good wear resistance, xenon lamp aging test and other properties, and can withstand high temperature processes and can be used to prepare high temperature resistant coated glass.

[0047] 4. The silica sol product provided by this invention can utilize the high-temperature stage of automotive glass bending to complete the coating curing process. The coating curing process can be carried out simultaneously with the glass bending process, saving the need for a separate high-temperature curing step, thus simplifying the production process and reducing energy consumption. This not only has economic benefits but also environmental benefits. Simultaneously, heat treatment can also be used to complete the silica sol condensation reaction, thereby densifying the coating and improving its mechanical properties. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the glass structure in the embodiments and comparative examples of the present invention.

[0049] Symbol explanation: Coating 1, glass substrate 2. Detailed Implementation

[0050] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0051] Example 1

[0052] This embodiment provides a silica sol, the preparation method of which includes:

[0053] (1) Using a three-necked flask equipped with a thermometer and a stirring device, add 150g tetraethyl orthosilicate, 25g methyltriethoxysilane, 10g KH560, 245g ethanol and 10g propylene glycol methyl ether acetate, and start stirring.

[0054] (2) Dissolve 0.25g of hydrochloric acid in 60g of water and stir until homogeneous to obtain a catalyst solution. Add the catalyst solution to a three-necked flask and continue stirring.

[0055] (3) Heat to 50°C, keep warm for 6 hours, then cool to room temperature. The discharged material is silica sol. This silica sol is a high-temperature resistant silica sol.

[0056] This embodiment also provides a type of glass. For example... Figure 1 As shown, the glass includes a glass substrate 2 and a coating 1, with the coating 1 covering the surface of the glass substrate 2. The coating 1 is a high-temperature resistant coating, formed by curing the silica sol prepared in this embodiment. The glass preparation method of this embodiment includes the following steps:

[0057] (1) Dilute the silica sol solution by 3 times, that is, take 100g of silica solution stock solution and add 200g of ethanol, stir evenly to obtain silica sol coating.

[0058] (2) After cleaning and drying the glass substrate, the above-mentioned silica sol coating is applied to the glass substrate using a spray coating process.

[0059] (3) After the coating surface is dry, the coated glass is placed in a muffle furnace and cured at 550°C for 10 minutes. After cooling, the glass is prepared and can be used as a high-temperature resistant coated automotive glass.

[0060] Example 2

[0061] This embodiment provides a silica sol, the preparation method of which includes:

[0062] (1) Using a three-necked flask equipped with a thermometer and a stirring device, add 100g tetraethyl orthosilicate, 50g methyltriethoxysilane, 25g KH560, 245g ethanol and 20g propylene glycol methyl ether acetate, and start stirring.

[0063] (2) Dissolve 0.25g of hydrochloric acid in 60g of water and stir until homogeneous to obtain a catalyst solution. Add the catalyst solution to a three-necked flask and continue stirring.

[0064] (3) Heat to 55°C, keep warm for 5.5 hours, then cool to room temperature. The discharged material is silica sol. This silica sol is a high-temperature resistant silica sol.

[0065] This embodiment also provides a type of glass. For example... Figure 1 As shown, the glass includes a glass substrate 2 and a coating 1, with the coating 1 covering the surface of the glass substrate 2. The coating 1 is a high-temperature resistant coating, formed by curing the silica sol prepared in this embodiment. The glass preparation method of this embodiment includes the following steps:

[0066] (1) Dilute the silica sol solution by 4 times, that is, take 100g of silica solution stock solution and add 300g of ethanol, stir evenly to obtain silica sol coating.

[0067] (2) After cleaning and drying the glass substrate, the above-mentioned silica sol coating is applied to the glass substrate using a spray coating process.

[0068] (3) After the coating surface is dry, the coated glass is placed in a muffle furnace and cured at 600°C for 9 minutes. After cooling, the glass is prepared and can be used as a high-temperature resistant coated automotive glass.

[0069] Example 3

[0070] This embodiment provides a method for preparing silica sol, including the following steps:

[0071] (1) Using a three-necked flask equipped with a thermometer and a stirring device, add 80g of tetraethyl orthosilicate, 70g of dimethyldiethoxysilane, 25g of KH570, 245g of isopropanol and 20g of diethylene glycol ethyl ether, and start stirring.

[0072] (2) Dissolve 0.25g of nitric acid in 60g of water and stir until homogeneous to obtain a catalyst solution. Add the catalyst solution to a three-necked flask and continue stirring.

[0073] (3) Heat to 60°C, keep warm for 5 hours, then cool to room temperature. The discharged material is silica sol. This silica sol is a high-temperature resistant silica sol.

[0074] This embodiment also provides a type of glass. For example... Figure 1 As shown, the glass includes a glass substrate 2 and a coating 1. The coating 1 is a high-temperature resistant coating formed by curing the silica sol described in this embodiment. The glass preparation method of this embodiment includes the following steps:

[0075] (1) Dilute the silica sol solution by 4 times, that is, take 100g of silica solution stock solution and add 300g of isopropanol, stir evenly to obtain silica sol coating.

[0076] (2) After cleaning and drying the glass substrate, the above-mentioned silica sol coating is applied to the glass substrate using a spray coating process.

[0077] (3) After the coating surface is dry, the coated glass is placed in a muffle furnace and cured at 650°C for 8 minutes. After cooling, the glass is prepared. This glass is a high-temperature resistant coated automotive glass.

[0078] Example 4

[0079] This embodiment provides a method for preparing silica sol, including the following steps:

[0080] (1) Using a three-necked flask equipped with a thermometer and a stirring device, add 25g tetramethyl orthosilicate, 150g phenyltrimethoxysilane, 5g KH570, 249.5g isopropanol and 5g diethylene glycol ethyl ether, and start stirring.

[0081] (2) Dissolve 0.5g of nitric acid in 65g of water and stir until homogeneous to obtain a catalyst solution. Add the catalyst solution to a three-necked flask and continue stirring.

[0082] (3) Heat to 70°C, keep warm for 4 hours, then cool to room temperature. The discharged material is silica sol. This silica sol is a high-temperature resistant silica sol.

[0083] This embodiment also provides a type of glass. For example... Figure 1 As shown, the glass includes a glass substrate 2 and a coating 1. The coating 1 is a high-temperature resistant coating formed by curing the silica sol described in this embodiment. The glass preparation method of this embodiment includes the following steps:

[0084] (1) Dilute the silica sol solution by 5 times, that is, take 100g of silica solution stock solution and add 400g of isopropanol, stir evenly to obtain silica sol coating.

[0085] (2) After cleaning and drying the glass substrate, the above-mentioned silica sol coating is applied to the glass substrate using a spray coating process.

[0086] (3) After the coating surface is dry, the coated glass is placed in a muffle furnace and cured at 750°C for 5 minutes. After cooling, the glass is prepared. This glass is a high-temperature resistant coated automotive glass.

[0087] In the above embodiments, since the curing process in step (3) is carried out in a muffle furnace with limited space, the curing process does not include the glass bending process. When the preparation method of the above embodiments needs to be applied to the glass bending process, the curing process can be combined with the glass bending process, that is, the coating curing is completed during the glass bending process.

[0088] Comparative Example 1

[0089] This comparative example provides a method for preparing silica sol, including the following steps:

[0090] (1) Using a three-necked flask equipped with a thermometer and a stirring device, add 150g of tetraethyl orthosilicate, 25g of KH560, 245g of ethanol and 20g of propylene glycol methyl ether acetate, and start stirring.

[0091] (2) Dissolve 0.25g of hydrochloric acid in 60g of water and stir until homogeneous to obtain a catalyst solution. Add the catalyst solution to a three-necked flask and continue stirring.

[0092] (3) Heat to 55°C, keep warm for 5.5 hours, then cool down to room temperature. The discharged material is silica sol.

[0093] This comparative example provides a type of glass, such as... Figure 1 As shown, the glass comprises a glass substrate 2 and a coating 1. The coating is a high-temperature resistant coating, formed by curing the silica sol of this comparative example. The preparation method of the glass of this comparative example includes the following steps:

[0094] (1) Dilute the silica sol solution by 4 times, that is, take 100g of silica solution stock solution and add 300g of ethanol, stir evenly to obtain silica sol coating.

[0095] (2) After cleaning and drying the glass sheet, the above-mentioned silica sol coating is applied to the glass substrate using a spray coating process.

[0096] (3) After the coating surface is dry, the coated glass is placed in a muffle furnace and cured at 600°C for 9 minutes. After cooling, the glass is prepared as a high-temperature resistant coated automotive glass.

[0097] Comparative Example 2

[0098] This comparative example provides a method for preparing silica sol, including the following steps:

[0099] (1) Using a three-necked flask equipped with a thermometer and a stirring device, add 140g tetraethyl orthosilicate, 10g methyltriethoxysilane, 25g KH560, 245g ethanol and 20g propylene glycol methyl ether acetate, and start stirring.

[0100] (2) Dissolve 0.25g of hydrochloric acid in 60g of water and stir until homogeneous to obtain a catalyst solution. Add the catalyst solution to a three-necked flask and continue stirring.

[0101] (3) Heat to 55°C, keep warm for 5.5 hours, then cool down to room temperature. The discharged material is silica sol.

[0102] This comparative example provides a type of glass, such as... Figure 1 As shown, the glass comprises a glass substrate 2 and a coating 1. The coating is a high-temperature resistant coating, formed by curing the silica sol of this comparative example. The preparation method of the glass of this comparative example includes the following steps:

[0103] (1) Dilute the silica sol solution by 4 times, that is, take 100g of silica solution stock solution and add 300g of ethanol, stir evenly to obtain silica sol coating.

[0104] (2) After cleaning and drying the glass sheet, the above-mentioned silica sol coating is applied to the glass substrate using a spray coating process.

[0105] (3) After the coating surface is dry, the coated glass is placed in a muffle furnace and cured at 600°C for 9 minutes. After cooling, the glass is prepared as a high-temperature resistant coated automotive glass.

[0106] Comparative Example 3

[0107] This comparative example provides a method for preparing silica sol, including the following steps:

[0108] (1) Using a three-necked flask equipped with a thermometer and a stirring device, add 150g of dimethyldiethoxysilane, 25g of KH570, 245g of isopropanol and 20g of diethylene glycol ethyl ether, and start stirring.

[0109] (2) Dissolve 0.25g of nitric acid in 60g of water and stir until homogeneous to obtain a catalyst solution. Add the catalyst solution to a three-necked flask and continue stirring.

[0110] (3) Heat to 60°C, keep warm for 5 hours, then cool down to room temperature. The discharged material is silica sol.

[0111] This comparative example provides a type of glass, such as... Figure 1 As shown, the glass comprises a glass substrate 2 and a coating 1. The coating is a high-temperature resistant coating, formed by curing the silica sol of this comparative example. The preparation method of the glass of this comparative example includes the following steps:

[0112] (1) Dilute the silica sol solution by 4 times, that is, take 100g of silica solution stock solution and add 300g of isopropanol, stir evenly to obtain silica sol coating.

[0113] (2) After cleaning and drying the glass sheet, the above-mentioned silica sol coating is applied to the glass substrate using a spray coating process.

[0114] (3) After the coating surface is dry, the coated glass is placed in a muffle furnace and cured at 650°C for 8 minutes. After cooling, the glass is prepared as a high-temperature resistant coated automotive glass.

[0115] Comparative Example 4

[0116] This comparative example provides a method for preparing silica sol, including the following steps:

[0117] (1) Using a three-necked flask equipped with a thermometer and a stirring device, add 80g of tetraethyl orthosilicate, 70g of dimethyldiethoxysilane, 25g of KH570, 245g of isopropanol and 20g of diethylene glycol ethyl ether, and start stirring.

[0118] (2) Dissolve 1g of nitric acid in 60g of water and stir until homogeneous to obtain a catalyst solution. Add the catalyst solution to a three-necked flask and continue stirring.

[0119] (3) Heat to 60°C, keep warm for 5 hours, then cool down to room temperature. The discharged material is silica sol.

[0120] This comparative example provides a type of glass, such as... Figure 1 As shown, the glass comprises a glass substrate 2 and a coating 1. The coating is a high-temperature resistant coating, formed by curing the silica sol of this comparative example. The preparation method of the glass of this comparative example includes the following steps:

[0121] (1) Dilute the silica sol solution by 4 times, that is, take 100g of silica solution stock solution and add 300g of isopropanol, stir evenly to obtain silica sol coating.

[0122] (2) After cleaning and drying the glass sheet, the above-mentioned silica sol coating is applied to the glass substrate using a spray coating process.

[0123] (3) After the coating surface is dry, the coated glass is placed in a muffle furnace and cured at 650°C for 8 minutes. After cooling, the glass is prepared as a high-temperature resistant coated automotive glass.

[0124] Test Example 1

[0125] This test example provides the test results for the appearance, coating thickness, visible light transmittance, haze, reflectance, abrasion resistance, and aging resistance of the high-temperature coated automotive glass of Examples 1, 2, 3, and 4, and Comparative Examples 1, 2, 3, and 4. The results are summarized in Table 1. The original glass sheet (i.e., glass substrate 2 in the above examples and comparative examples) used was ordinary clear glass with a thickness of 2 mm, a visible light transmittance of 93.0%, a haze of 0.20%, and a reflectance of 8.24%. The test methods for each parameter are as follows:

[0126] Coating thickness: The coating thickness was measured using a spectroelliptic spectrometer.

[0127] Visible light transmittance: The transmittance spectrum in the wavelength range of 250-2500 nm was measured using a spectrophotometer. The visible light transmittance of 380-780 nm was calculated according to ISO 9050 standard. The transmittance mentioned in this application refers to the average value obtained by measuring five different points on the same glass sample.

[0128] Reflectance: The reflectance of light in the wavelength range of 360-780nm is measured using a spectrophotometer to obtain the average reflectance.

[0129] Abrasion resistance: Using a surface abrasion tester, the glass sample is placed on the instrument with the coating facing up, and a surface abrasion test is performed on it for 500 revolutions under a pressure of 4.9N.

[0130] Haze: A haze meter was used to test the glass samples before and after the abrasion resistance test. Haze H1 was obtained from the area that did not undergo the abrasion resistance test, and haze H2 was obtained from the area that did undergo the abrasion resistance test. The difference in haze before and after the test was calculated as H2 - H1. A haze difference of less than 2% before and after the test was considered acceptable for the coating's abrasion resistance.

[0131] Aging resistance: The aging resistance test method is to put the sample into a xenon lamp aging chamber, with a rainfall cycle of 102 minutes of drying followed by 18 minutes of rainfall, and a concentration of 300-400nm: 60±2w / m. 2 To determine the radiation intensity, the test duration was 3000 hours, the blackboard temperature was 65±3℃, and the relative humidity was 50±10% for the aging resistance test. After the aging resistance test, the appearance of the coating was observed to see if cracks appeared.

[0132] Table 1

[0133]

[0134] As shown in Table 1, the high-temperature resistant coatings for automotive glass prepared in Examples 1, 2, 3, and 4, and Comparative Examples 1, 2, 3, and 4, exhibited normal appearance after high-temperature curing, with high visible light transmittance, low haze, and low reflectivity. Regarding abrasion resistance and aging resistance, the automotive glass coatings in Examples 1, 2, 3, and 4 passed both tests. The automotive glass coatings in Comparative Examples 1, 2, 3, and 4 passed the aging resistance test but failed the abrasion resistance test, exhibiting significant changes in haze after the abrasion test.

[0135] The reason for the difference in abrasion resistance between the automotive glass coatings in the examples and the comparative examples is:

[0136] Comparative Examples 1, 2, and 2 serve as control experiments. It is understood that the coating thicknesses of Comparative Examples 1, 2, and 2 differ from those of Example 2 by 15 nm and 1 nm, respectively. This degree of difference in coating thickness is an unavoidable error during the preparation process and will not significantly affect the optical and mechanical performance test results. The differences in performance results in the above experiments mainly stem from the differences in preparation parameters. Compared to Example 2, the silica sol formulation in Comparative Example 1 contains only tetraethyl orthosilicate as an alkoxysilane raw material, while the silica sol formulation in Comparative Example 2 has an excessively high proportion of tetraethyl orthosilicate. During the sol-gel reaction, due to the excessive amount of hydrolyzable alkoxy groups, the initial hydrolysis reaction is too rapid, and the subsequent condensation reaction is incomplete. This leads to a decrease in the density of the coating and a reduction in the adhesion between the coating and the glass, thereby reducing the wear resistance of the coating.

[0137] Comparative Examples 3, 4, and 3 serve as control experiments. It is understood that the coating thicknesses of Comparative Examples 3 and 4 differ from those of Example 3 by 12 nm and 5 nm, respectively. This difference in coating thickness is an unavoidable error during the preparation process and will not significantly affect the optical and mechanical performance test results. The differences in performance results in the above experiments mainly stem from the differences in preparation parameters. Compared to Example 3, the silica sol formulation in Comparative Example 3 contains only dimethyldiethoxysilane as the alkoxysilane raw material. During the sol-gel reaction, due to the relatively low number of hydrolyzable alkoxy groups, the initial hydrolysis reaction is slow, leading to partial hydrolysis and condensation of silanes to generate sol products with lower cross-linking degrees. This reduces the coating density and consequently decreases the coating's wear resistance. In Comparative Example 4, the excessive amount of nitric acid catalyst results in a too-fast hydrolysis rate, increasing the formation of Si-OH bonds. This easily leads to the formation of particulate aggregates, and condensation tends to occur within the particles, while less polymerization occurs between particles. This results in reduced coating density and poor wear resistance.

[0138] Compared with Comparative Examples 1 to 4, the silica sol raw materials of Examples 1, 2, 3 and 4 are composed of two alkoxysilanes, with a moderate number of hydrolyzable alkoxy groups, sufficient degree of hydrolysis and condensation, and the resulting coating structure is dense, has strong adhesion to glass, and has high wear resistance.

[0139] The above results demonstrate that the silica sol provided by this invention bonds firmly to the glass surface, forming a dense, high-hardness, high-temperature resistant, wear-resistant, and aging-resistant coating. Glass coated with this material exhibits excellent optical properties and weather resistance. Furthermore, the coating formation process can be combined with the bending and shaping process during preparation, simplifying the production process, reducing energy consumption, and providing both economic and environmental benefits.

[0140] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application, and such improvements and refinements are also considered to be within the protection scope of this application.

Claims

1. A silica sol, the raw materials of which include a composite alkoxysilane, a silane coupling agent, an organic solvent, an additive, a catalyst and water in a mass ratio of 30-40:1-5:45-60:1-5:0.01-0.1:8-13; in, The composite alkoxysilane comprises a first alkoxysilane and a second alkoxysilane in a mass ratio of 1:6 to 6:

1. The structural formula of the first alkoxysilane is: Si(OR) 1 )4, R 1 It is an alkyl group; The structural formula of the second alkoxysilane is: R 2 n Si(OR 3 ) 4-n n is 1 or 2, R 2 R is a non-hydrolyzable organic functional group. 3 For alkyl.

2. The silica sol according to claim 1, wherein, In the structural formula of the first alkoxysilane, R 1 It is selected from one or more combinations of methyl, ethyl and propyl.

3. The silica sol according to claim 1, wherein, In the structural formula of dialkoxysilane: R 2 Including alkyl and / or phenyl, R 3 It is selected from one or more combinations of methyl, ethyl and propyl.

4. The silica sol according to claim 3, wherein, R 2 It is selected from one or more combinations of methyl, ethyl, and phenyl.

5. The silica sol according to claim 1, wherein, The silane coupling agent includes γ-glycidoxypropyltrimethoxysilane and / or γ-methacryloxypropyltrimethoxysilane.

6. The silica sol according to claim 1, wherein, The organic solvents include ethanol and / or isopropanol.

7. The silica sol according to claim 1, wherein, The adjuvants include propylene glycol methyl ether acetate and / or diethylene glycol ethyl ether.

8. The silica sol according to claim 1, wherein, The catalyst includes an acidic catalyst.

9. The silica sol according to claim 8, wherein, The catalyst includes hydrochloric acid and / or nitric acid.

10. A method for preparing silica sol according to any one of claims 1-9, the method comprising: A solution A is obtained by mixing a composite alkoxysilane, a silane coupling agent, an organic solvent, and an auxiliary agent. The catalyst and water were mixed to obtain solution B; Solution A and solution B are mixed and reacted to obtain the silica sol solution.

11. The preparation method according to claim 10, wherein, The reaction temperature is 50℃-70℃, and the reaction time is 4h-6h.

12. A glass comprising a glass substrate and a coating applied to the surface of the glass substrate, said coating being formed by curing a silica sol according to any one of claims 1-9.

13. The glass according to claim 12, wherein, The glass is automotive glass.

14. The glass according to claim 12, wherein, The difference in haze of the glass before and after the abrasion resistance test is less than or equal to 2%.

15. The glass according to claim 14, wherein, The difference in haze of the glass before and after the abrasion resistance test is less than or equal to 1.5%.

16. The glass according to claim 12, wherein, The thickness of the coating is 100-1000 nm.

17. The glass according to claim 16, wherein, The coating has a thickness of 112-560 nm.

18. The glass according to claim 12, wherein, The glass has a transmittance of 93% or more for visible light with a wavelength of 380-780nm.

19. The glass according to claim 12, wherein, The haze of the glass is less than or equal to 1%.

20. The glass according to claim 19, wherein, The haze of the glass is less than or equal to 0.5%.

21. The glass according to claim 12, wherein, The glass has a reflectivity of less than or equal to 8% for visible light in the 360nm-780nm range.

22. The glass according to claim 21, wherein, The glass has a reflectance of less than or equal to 7% for visible light in the 360nm-780nm range.

23. A method for preparing the glass according to any one of claims 12-22, the method comprising: A coating is applied to the surface of a glass substrate, and the coating is cured to form a coating layer, thereby obtaining the glass. The coating comprises the silica sol as described in any one of claims 1-9.

24. The method for preparing glass according to claim 23, wherein, The preparation method includes: applying the coating to the surface of the glass substrate, bending the glass substrate, and simultaneously curing the coating to form a coating layer to obtain the glass.

25. The method for preparing glass according to claim 23 or 24, wherein, The curing temperature is 550℃-750℃, and the curing time is 5min-10min.

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