Glass treatment composition and preparation method thereof

Abstract

The invention provides a glass treatment composition and a preparation method thereof. The glass treatment composition comprises, based on the total weight thereof: 0.1-2% by weight of hydrophobic silica particles having an average particle size of 7-12 nm; 0.01 to 0.1 wt% of a quaternary ammonium salt; and 97.9 to 99.89% by weight of a solvent oil having a flash point in the range of 10 to 40 DEG C; wherein the quaternary ammonium salt has a structure represented by a general formula (I), and R is C12-C18 alkyl. The glass treatment composition of the present invention has excellent hydrophobicity and good transparency while exhibiting excellent durability and volatilization speed. Compared with an existing product, the glass treatment composition solves the problems of raindrop residue caused by insufficient hydrophobicity or good hydrophobicity but poor transparency, can effectively improve the visibility of automobile rearview mirror glass in rainy days, and meets actual use requirements.

Description

Technical Field

[0001] This invention relates to the field of automotive glass surface treatment technology, and more specifically to a glass treatment composition for automotive rearview mirrors and its preparation method. Background Technology

[0002] As a core component ensuring vehicle safety during driving, the visual clarity of a car's rearview mirror directly affects the driver's ability to judge their surroundings. This is especially true in adverse weather conditions such as rain and snow, where the functionality of the rearview mirror glass faces severe challenges. Conventional car rearview mirror glass has a natural hydrophilic nature. When raindrops or water mist adhere to the surface, they easily form continuous water films or discrete droplets, significantly reducing the glass's light transmittance and interfering with the driver's observation of vehicles, pedestrians, and obstacles behind them. At night or in low-light environments, the water film or droplets can also produce irregular reflections of surrounding light sources, creating glare or light spots, further exacerbating visual interference and increasing the potential risk of traffic accidents.

[0003] To address this issue, the industry widely employs techniques involving the application of functional coatings to glass surfaces. Among these, hydrophobic coatings have become a research hotspot due to their ability to reduce liquid adhesion and promote water droplet sliding. The working principle of hydrophobic coatings is to construct low-surface-energy microstructures or chemical layers on the glass surface, reducing the contact area between the liquid and the surface, allowing raindrops to quickly detach under gravity or wind force, thereby maintaining the transparency of the glass. However, existing hydrophobic coating technologies still face numerous technical bottlenecks in practical applications, making it difficult to achieve a comprehensive balance of performance.

[0004] On the one hand, some hydrophobic coatings lack sufficient hydrophobicity to effectively prevent liquids from spreading on the surface. These coatings often suffer from imprecise surface energy control or microscopic defects during film formation, causing raindrops to partially spread and form a water film upon contact with the surface, preventing them from forming a stable spherical shape and still obstructing vision. Furthermore, the hydrophobic effect of these coatings is not durable. After repeated rain erosion, the adhesion of environmental pollutants, or temperature changes, the surface chemical structure is prone to degradation, leading to a rapid decline in hydrophobicity and requiring frequent recoating to maintain the effect.

[0005] On the other hand, some coating products with excellent hydrophobic properties often have significant defects in transparency. This problem mainly stems from unreasonable selection of coating materials or improper preparation processes: for example, if the functional particles used in the coating are too large or unevenly dispersed, light will be scattered within the coating, causing haze on the glass surface; if the refractive index difference between the coating and the glass substrate is too large, reflection loss will occur at the interface, affecting the overall light transmittance. In addition, some coating materials are inherently colored or prone to yellowing, further reducing the visual clarity of the glass, especially under strong light or backlight conditions, where this defect is more pronounced.

[0006] Besides the conflict between hydrophobicity and transparency, existing coatings also fall short of practical requirements in terms of durability and ease of application. Insufficient durability is mainly reflected in the weak adhesion between the coating and the glass substrate, making it prone to peeling during daily use due to wiping, vibration, or chemical corrosion. Simultaneously, the coating has poor weather resistance; long-term exposure to ultraviolet radiation, high temperature, and high humidity environments can easily lead to oxidation, cracking, and other aging phenomena, resulting in performance failure. Regarding ease of application, some coatings require complex pretreatment procedures or specific curing conditions, which not only increases the difficulty of operation but also prolongs the construction time, hindering practical application.

[0007] In summary, existing hydrophobic treatment technologies for glass surfaces suffer from numerous mutually restrictive issues regarding hydrophobicity, transparency, durability, and ease of application, failing to fully meet the demands of automotive rearview mirrors under complex operating conditions. Developing a glass treatment composition that simultaneously achieves excellent hydrophobicity, high transparency, good durability, and ease of application has become a pressing technical challenge in this field. Summary of the Invention

[0008] Based on the technical problems described above, the technical objective of this invention is to develop a glass treatment composition and its preparation method. This composition can solve the problems of insufficient hydrophobicity leading to raindrop residue or good hydrophobicity but poor transparency in existing products. It needs to have both excellent hydrophobicity and good transparency, while ensuring excellent durability and evaporation rate, so as to effectively improve the visibility of automotive rearview mirror glass in rainy weather and meet the actual use needs.

[0009] The inventors of this invention completed this invention after in-depth and meticulous research.

[0010] Specifically, according to one aspect of the present invention, a glass treatment composition is provided, the glass treatment composition comprising, based on its total weight:

[0011] 0.1-2% by weight of hydrophobic silica particles with an average particle size of 7-12 nm;

[0012] 0.01-0.1% by weight of quaternary ammonium salts; and

[0013] Solvent oils with a flash point in the range of 10-40℃, comprising 97.9-99.89% by weight;

[0014] The quaternary ammonium salt has a structure represented by the following general formula (I):

[0015]

[0016] General Formula (I)

[0017] Where R is C 12 -C 18 alkyl.

[0018] According to another aspect of the present invention, a method for preparing the glass treatment composition according to the above description is provided, the method comprising uniformly mixing the components.

[0019] Compared with the prior art in this field, the advantages of the present invention are as follows:

[0020] 1. It achieves synergistic optimization of hydrophobicity and transparency, solving the problems of insufficient hydrophobicity leading to raindrop residue or excellent hydrophobicity but poor transparency in existing technologies, and can maintain good transparency while ensuring excellent hydrophobicity.

[0021] 2. It also has excellent durability. The treated glass surface can withstand a lot of water droplet impacts and can still maintain good hydrophobic effect after long-term use.

[0022] 3. Excellent evaporation rate and short drying time facilitate rapid construction and improve ease of use.

[0023] 4. The formula is rationally designed, using hydrophobic silica particles of specific particle size, quaternary ammonium salts with specific structures, and solvent oils with suitable flash points. The synergistic effect of each component makes the overall performance of the composition better, especially suitable for automotive rearview mirror glass treatment, effectively improving visibility in rainy weather. Detailed Implementation

[0024] It should be understood that, without departing from the scope or spirit of this disclosure, those skilled in the art can conceive of various other embodiments and can modify them based on the teachings of this specification. Therefore, the following specific embodiments are not intended to be limiting.

[0025] Unless otherwise specified, all figures used in this specification and claims to indicate feature dimensions, quantities, and physical properties should be understood to be modified by the term "about" in all cases. Therefore, unless stated to the contrary, the numerical parameters listed in the foregoing specification and appended claims are approximations, and those skilled in the art can appropriately modify these approximations to obtain the desired characteristics using the teachings disclosed herein. The use of numerical ranges indicated by endpoints includes all numbers within that range and any range within that range; for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, etc.

[0026] As mentioned above, the technical problem this invention aims to solve is that existing glass treatment products struggle to balance hydrophobicity and transparency. Automotive rearview mirror glass is hydrophilic; raindrops adhering to it during rain reduces transparency, especially at night where reflections impair visibility. Existing hydrophobic coatings either lack sufficient hydrophobicity, resulting in raindrop residue, or offer good hydrophobicity but poor transparency. Furthermore, some products suffer from poor durability and slow evaporation rates, failing to meet the comprehensive requirements of hydrophobicity, transparency, durability, and rapid drying in practical applications. Therefore, a glass treatment composition that can balance these properties is urgently needed.

[0027] The inventors of this invention discovered in their research that by combining hydrophobic silica particles (0.1-2 wt%) with an average particle size of 7-12 nm in a specific ratio, having the general formula (I) and R being C 12 -C 18 Alkyl quaternary ammonium salts (0.01-0.1 wt%) and solvent oils with flash points of 10-40°C (97.9-99.89 wt%) synergistically achieve excellent hydrophobicity, durability, volatility, and transparency in the resulting glass treatment composition. Specifically, hydrophobic silica particles of a certain particle size ensure a balance between hydrophobicity and transparency, the quaternary ammonium salts enhance coating adhesion and durability, and the solvent oils with specific flash points guarantee evaporation rates. This combination solves the problem of achieving both hydrophobicity and transparency in existing technologies, making it suitable for automotive rearview mirror glass treatment.

[0028] Specifically, according to one aspect of the present invention, a glass treatment composition is provided, the glass treatment composition comprising, based on its total weight:

[0029] 0.1-2% by weight of hydrophobic silica particles with an average particle size of 7-12 nm;

[0030] 0.01-0.1% by weight of quaternary ammonium salts; and

[0031] Solvent oils with a flash point in the range of 10-40℃, comprising 97.9-99.89% by weight;

[0032] The quaternary ammonium salt has a structure represented by the following general formula (I):

[0033]

[0034] General Formula (I)

[0035] Where R is C 12 -C 18 alkyl.

[0036] According to the technical solution of the present invention, the glass treatment composition, based on its total weight, mainly consists of three core components: hydrophobic silica particles, quaternary ammonium salt, and solvent oil, as described in detail below. The synergistic effect of each component is the key to achieving the excellent technical performance of the present invention.

[0037] Specifically, the glass treatment composition comprises 0.1-2% by weight of hydrophobic silica particles with an average particle size of 7-12 nm. This specific particle size range is of great significance to the technical effectiveness of the present invention.

[0038] From a hydrophobicity perspective, 7-12 nm nanoparticles can form a microscopic rough structure on the glass surface, enhancing hydrophobic properties. Particles that are too small (e.g., less than 7 nm) are prone to aggregation, leading to uneven surface energy distribution and thus reducing hydrophobicity; while particles that are too large (e.g., greater than 12 nm) will significantly reduce the transparency of the glass due to light scattering.

[0039] From a transparency perspective, the particle size of 7-12 nm is much smaller than the wavelength of visible light (400-760 nm), which can reduce the scattering of light and ensure that the coating has almost no impact on the light transmittance of the glass.

[0040] The inventors of this invention discovered in their research that when the content of hydrophobic silica particles is less than 0.1% by weight, the hydrophobic silica particles cannot form a continuous hydrophobic layer, resulting in a significant decrease in durability; when the content of hydrophobic silica particles is greater than 2% by weight, the particles tend to agglomerate, leading to a decrease in transparency. According to some preferred embodiments of the present invention, a content of 0.5-2% by weight of hydrophobic silica particles can achieve a better balance between hydrophobicity and transparency.

[0041] The hydrophobic silica particles are silica particles with a surface hydrophobic treatment, specifically achieved through treatment with a silane coupling agent or a siloxane. The silane coupling agent can be one or more selected from trimethylethoxysilane, trimethylchlorosilane, propyldimethylchlorosilane, 3-glycidoxypropyltrimethoxysilane, octyltrichlorosilane, octadecyltrimethoxysilane, and 3-propyltriethoxysilane. The siloxane can be one or more selected from octamethylcyclotetrasiloxane, polydimethylsiloxane, hexamethyldisiloxane, 1,3-dibutyltetramethyldisiloxane, hexaethyldisiloxane, and 3-(1,2-epoxypropoxy)propylpentamethyldisiloxane. These treatment agents can introduce hydrophobic groups (such as methyl, alkyl, etc.) onto the surface of the silica particles, reducing the surface energy of the particles and enhancing their compatibility with other components.

[0042] According to the technical solution of the present invention, the glass treatment composition comprises 0.01-0.1% by weight of a quaternary ammonium salt, which has a structure represented by general formula (I):

[0043]

[0044] Where R is C 12 -C 18 alkyl.

[0045] Unbound by theory, the quaternary ammonium salt is believed to play multiple key roles in the composition. For example, the quaternary ammonium salt can enhance adhesion. Specifically, the siloxy group (-Si(OR)3) in the quaternary ammonium salt molecule can undergo a hydrolytic condensation reaction with the hydroxyl groups (-OH) on the glass surface to form a chemical covalent bond, significantly improving the adhesion between the coating and the glass substrate, thereby improving durability. Furthermore, the quaternary ammonium salt can also synergistically improve hydrophobic properties. Specifically, the long-chain alkyl group (R = C) in the quaternary ammonium salt molecule... 12 -C 18 Alkyl groups possess strong hydrophobicity and can synergistically reduce the surface energy of the coating and enhance hydrophobicity with hydrophobic silica particles. When R is a straight-chain alkyl group, the molecular arrangement is more regular, and the hydrophobic effect is more stable; preferably, R is C 15 -C 18 Straight-chain alkyl groups, with their longer chain structure, can further enhance durability and hydrophobicity.

[0046] The inventors of this invention discovered during their research that when the content of the quaternary ammonium salt is below 0.01% by weight, sufficient covalent bonds cannot be formed, resulting in decreased durability; when the content of the quaternary ammonium salt is above 0.1% by weight, excess quaternary ammonium salt will crystallize on the coating surface, leading to decreased transparency. Preferably, the content of the quaternary ammonium salt is 0.05-0.1% by weight, which achieves a balance between adhesion and transparency.

[0047] According to the technical solution of the present invention, the glass treatment composition comprises 97.9-99.89% by weight of solvent oil, with a flash point in the range of 10-40°C. The main function of the solvent oil is to disperse hydrophobic silica particles and quaternary ammonium salts, ensuring that the composition can be uniformly adhered to the glass surface during application and evaporates rapidly after application to form a uniform coating. During spraying or coating, the fluidity of the solvent oil ensures that the composition can fully cover the glass surface to form a continuous treatment layer; after application, its reasonable evaporation rate (based on flash point design) allows the solvent to evaporate quickly, promoting rapid film formation and reducing waiting time. In addition, the compatibility of the solvent oil with other components ensures that during solvent evaporation, the hydrophobic silica particles and quaternary ammonium salts can be orderly arranged on the glass surface, fully exerting their respective hydrophobic and adhesion effects, and ensuring the overall performance of the coating.

[0048] The inventors of this invention discovered during their research that solvent oil with a flash point in the range of 10-40°C is crucial for achieving the technical effects of this invention. Specifically, when the flash point is between 10-40°C, the solvent oil has a moderate vapor pressure at room temperature, allowing it to evaporate rapidly within a short time after spraying, promoting the rapid formation of a uniform coating of hydrophobic silica particles and quaternary ammonium salts on the glass surface. If the flash point is higher than 40°C, the evaporation rate of the solvent oil slows down significantly, resulting in a drying time exceeding 10 minutes, failing to meet the technical effect of "rapid construction," and potentially causing defects such as sagging and fogging due to solvent residue. Solvent oil with a flash point of 10-40°C has a moderate evaporation rate, allowing it to gradually evaporate after the hydrophobic silica particles and quaternary ammonium salts have fully spread, avoiding uneven component distribution (such as local particle agglomeration) due to excessively rapid evaporation or excessively thick coating due to excessively slow evaporation. If the flash point deviates from 10-40℃, it may damage the uniformity of the coating: if the flash point is too low (e.g., <10℃), the solvent oil evaporates instantly, which may cause the components to fail to spread fully, forming local voids and affecting hydrophobicity; if the flash point is too high (e.g., >40℃), the solvent will remain for a long time, causing the particles to agglomerate again and damaging the transparency.

[0049] Preferably, from the perspective of simultaneously obtaining excellent hydrophobicity, durability and volatility, the flash point of the solvent oil is in the range of 10-20°C.

[0050] Solvent oils with a flash point in the range of 20-40°C preferably contain C. 6-12 Hydrocarbons, these types of hydrocarbon solvents have good compatibility with hydrophobic silica particles and quaternary ammonium salts, which can reduce agglomeration during the dispersion process and further improve the uniformity of the coating.

[0051] To further optimize the performance of the composition, the glass treatment composition of the present invention may further comprise C1-C3 alcohols. The composition may additionally comprise one or more C1-C3 alcohols, such as methanol, ethanol, n-propanol, or isopropanol. The addition of C1-C3 alcohols can adjust the polarity of the solvent system, enhance the dispersion stability of hydrophobic silica particles and quaternary ammonium salts, and especially prevent particle agglomeration in low-temperature environments (such as winter construction). Simultaneously, alcohol solvents are volatile and will not affect the overall evaporation rate.

[0052] Optionally, the glass treatment composition of the present invention may further comprise one or more of antioxidants (such as hindered phenols and phosphites) and toughening agents (such as polysiloxane elastomers). Antioxidants can inhibit the oxidative degradation of quaternary ammonium salts and hydrophobic silica particles during long-term use, extending the coating life; toughening agents can improve the flexibility of the coating and reduce cracking caused by temperature changes or vibration, making it particularly suitable for areas with large temperature differences.

[0053] According to another aspect of the present invention, a method for preparing the glass treatment composition according to the above description is provided, the method comprising uniformly mixing the components.

[0054] The preparation method of the glass treatment composition of the present invention includes uniformly mixing the components, which can be specifically divided into the following steps:

[0055] Dispersing hydrophobic silica particles: Add the measured amount of solvent oil to the container, then add the hydrophobic silica particles, and use a homogenizer to stir at a speed of 3000-4000 rpm for 10-15 minutes to ensure that the particles are completely dispersed and there is no obvious agglomeration.

[0056] Add quaternary ammonium salt: Add the measured amount of quaternary ammonium salt to the above dispersion and continue stirring at a speed of 1000-2000 rpm for 5-10 minutes to ensure that the quaternary ammonium salt is evenly dispersed and fully reacts with the silica particles.

[0057] Optional components: If C1-C3 alcohols, antioxidants or toughening agents need to be added, they can be added sequentially after the quaternary ammonium salt is dispersed, and stirred for 5-8 minutes until the system is homogeneous.

[0058] Filtration (optional): To remove any large particulate impurities that may be present, the mixed composition can be filtered through a 0.22 μm filter membrane to obtain the final product.

[0059] This preparation method is simple to operate, requires no high temperature or high pressure conditions, and is suitable for industrial production. By controlling the stirring speed and time in each step, the components can be uniformly dispersed, thereby ensuring the stability of the coating performance.

[0060] The glass treatment composition of the present invention exhibits the following significant advantages through the synergistic effect of the above-mentioned components:

[0061] (1) Excellent hydrophobicity: The micro-rough structure of hydrophobic silica particles and the long-chain alkyl of quaternary ammonium salt work together to reduce the surface energy of the coating, allowing raindrops to quickly detach from the glass surface.

[0062] (2) Good transparency: 7-12 nm silica particles can reduce light scattering, and the quaternary ammonium salt has good refractive index matching with the glass substrate, avoiding the generation of rainbow patterns or haze.

[0063] (3) Excellent durability: The covalent bond between the quaternary ammonium salt and the glass surface and the physical support of the silica particles enable the coating to withstand repeated rain erosion.

[0064] (4) Rapid evaporation rate: The solvent oil with a flash point of 10-40℃ can completely evaporate within 5-10 minutes, ensuring rapid film formation of the coating and reducing construction waiting time.

[0065] (5) Wide applicability: The composition of the present invention is not only applicable to automotive rearview mirror glass, but also to other glass components such as automotive windshields and side windows, and can even be extended to architectural glass, eyeglass lenses and other fields, with broad application prospects.

[0066] The glass treatment composition of the present invention is simple and convenient to use, and specifically includes the following steps:

[0067] Wipe the glass surface with alcohol or a special glass cleaner to remove oil, dust and other impurities, ensuring the surface is clean and dry.

[0068] Apply the composition evenly to the glass surface using a spray bottle or applicator, ensuring complete coverage. The optimal ambient temperature for application is 10-30°C, with a relative humidity below 70%, to prevent moisture from affecting the coating's film formation.

[0069] After application, allow it to stand for 5-10 minutes to allow the solvent oil to completely evaporate, forming a hydrophobic coating. No additional heating or UV curing is required, making it suitable for users to apply themselves.

[0070] The following detailed description is intended to illustrate the contents of this disclosure by way of example and not by way of limitation.

[0071] Specific embodiment 1 is a glass treatment composition, which comprises, based on its total weight:

[0072] 0.1-2% by weight of hydrophobic silica particles with an average particle size of 7-12 nm;

[0073] 0.01-0.1% by weight of quaternary ammonium salts; and

[0074] Solvent oils with a flash point in the range of 10-40℃, comprising 97.9-99.89% by weight;

[0075] The quaternary ammonium salt has a structure represented by the following general formula (I):

[0076]

[0077] Where R is C 12 -C 18 alkyl.

[0078] Specific embodiment 2 is the glass processing composition described in specific embodiment 1, wherein the hydrophobic silica particles are silica particles whose surface has been hydrophobically treated.

[0079] Specific embodiment 3 is the glass processing composition described in specific embodiment 1, wherein the hydrophobic silica particles are silica particles whose surface has been treated with a silane coupling agent or siloxane.

[0080] Specific embodiment 4 is the glass treatment composition described in specific embodiment 3, wherein the silane coupling agent is selected from one or more of the following groups: trimethylethoxysilane, trimethylchlorosilane, propyldimethylchlorosilane, 3-glycidoxypropyltrimethoxysilane, octyltrichlorosilane, octadecyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

[0081] Specific embodiment 5 is the glass processing composition described in specific embodiment 3, wherein the siloxane is selected from one or more of the following groups: octamethylcyclotetrasiloxane, polydimethylsiloxane, hexamethyldisiloxane, 1,3-dibutyltetramethyldisiloxane, hexaethyldisiloxane, and 3-(1,2-epoxypropoxy)propylpentamethyldisiloxane.

[0082] Specific embodiment 6 is the glass treatment composition described in specific embodiment 1, wherein the glass treatment composition comprises 0.5-2% by weight of the hydrophobic silica particles.

[0083] Specific embodiment 7 is the glass processing composition described in specific embodiment 1, wherein in general formula (I), R is C 12 -C 18 Straight-chain alkyl groups.

[0084] Specific embodiment 8 is the glass processing composition described in specific embodiment 1, wherein in general formula (I), R is C 15 -C 18 Straight-chain alkyl groups.

[0085] Specific embodiment 9 is the glass treatment composition described in specific embodiment 1, wherein in general formula (I), R is n-dodecyl or n-octadecyl.

[0086] Specific embodiment 10 is the glass treatment composition described in specific embodiment 1, wherein the glass treatment composition contains 0.05-0.1% by weight of the quaternary ammonium salt.

[0087] Specific embodiment 11 is the glass processing composition described in specific embodiment 1, wherein the flash point of the solvent oil is in the range of 10-20°C.

[0088] Specific embodiment 12 is the glass processing composition described in specific embodiment 1, wherein the solvent oil with a flash point in the range of 10-40°C contains C. 6-12 hydrocarbon.

[0089] Specific embodiment 13 is the glass treatment composition described in specific embodiment 1, wherein the glass treatment composition further comprises C1-C3 alcohol.

[0090] Specific embodiment 14 is the glass processing composition described in specific embodiment 13, wherein the C1-C3 alcohol is selected from one or more of the group consisting of methanol, ethanol, n-propanol and isopropanol.

[0091] Specific embodiment 15 is the glass treatment composition described in specific embodiment 1, wherein the glass treatment composition further comprises one or more of an antioxidant and a toughening agent.

[0092] Specific embodiment 16 is the glass treatment composition described in specific embodiment 1, wherein the glass treatment composition is an automotive rearview mirror glass treatment composition.

[0093] Specific embodiment 17 is a method for preparing a glass treatment composition according to any one of specific embodiments 1-16, the method comprising uniformly mixing the components.

[0094] The present invention will now be described in more detail with reference to embodiments. It should be noted that these descriptions and embodiments are intended to facilitate understanding of the invention and are not intended to limit the invention. The scope of protection of the present invention is defined by the appended claims.

[0095] Example

[0096] In this invention, unless otherwise specified, all reagents used are commercially available products and are used directly without further purification.

[0097] Table 1 below lists the raw material information used in the embodiments and comparative examples of the present invention.

[0098] Table 1. Raw material information used in the embodiments and comparative examples of the present invention.

[0099]

[0100] Test methods

[0101] Hydrophobicity, durability, volatility (evaporation rate), and transparency tests were performed on the glass treatment compositions prepared in the following examples and comparative examples according to the methods described in detail below.

[0102] Hydrophobicity test

[0103] A clean glass slide measuring 5cm × 10cm was selected as the test substrate. The glass treatment composition to be tested was evenly sprayed onto the glass surface using a spray device, ensuring that the composition completely covered the entire glass slide, and left to stand for 10 minutes. Then, the treated glass slide was placed horizontally on the experimental table, and deionized water was drawn up with a dropper and added to the glass surface.

[0104] Evaluation criteria:

[0105] Observe the state of the water droplets on the glass surface and score them according to the following criteria:

[0106] A+: The water droplet detaches immediately upon contact with the glass surface;

[0107] A: The water droplet detaches from the glass surface within 2-3 seconds;

[0108] B: The water droplet is clearly spherical, but still remains on the glass surface;

[0109] C: The water droplet shape is not obvious and it remains on the glass surface.

[0110] In the application of the product according to the present invention for the hydrophobic coating of rearview mirrors, in terms of hydrophobicity, A+ is "excellent"; A is "good"; B is "unacceptable"; and C is "poor".

[0111] Durability test

[0112] Select a clean glass slide measuring 5cm x 10cm. Using a spray device, evenly spray the glass treatment composition to be tested onto the glass surface, ensuring the composition completely covers the entire glass slide. Let it stand for 10 minutes. Then, fix the treated glass slide at a 45-degree angle and place it 10cm directly below a water tap. Turn on the tap and control the water flow to drip continuously onto the glass surface at a rate of 1-2 drops per second.

[0113] Evaluation criteria:

[0114] Observe the state of the water droplets on the glass surface, record the total number of water droplets that fall from the surface until they no longer bounce off and remain attached, and score them according to the following criteria:

[0115] A+: The cumulative number of water droplets is greater than 200;

[0116] A: The cumulative number of water droplets is 100-200;

[0117] B: The cumulative number of water droplets is 50-100;

[0118] C: The cumulative number of water droplets is less than 50.

[0119] In terms of durability, for the application of the product according to the present invention in the hydrophobic coating of rearview mirrors, A+ is "excellent"; A is "good"; B is "unacceptable"; and C is "poor".

[0120] Volatility (evaporation rate) test

[0121] Select a clean glass slide measuring 5cm × 10cm. Use a spray device to evenly spray the glass treatment composition to be tested onto the glass surface, ensuring that the composition completely covers the entire glass slide. After the composition is sprayed, start timing and test and score the hydrophobicity of the glass surface at different drying time points (e.g., immediately after spraying, 3 minutes, 5 minutes, 10 minutes, etc.) according to the above-described "Hydrophobicity Test Method".

[0122] Evaluation criteria:

[0123] Record the drying time taken for the glass surface to achieve a hydrophobicity rating of A, and score it according to the following criteria:

[0124] A+: Drying time < 5 minutes;

[0125] A: Drying time is 5-10 minutes;

[0126] B: Drying time is 10-30 minutes;

[0127] C: Drying time > 30 minutes.

[0128] In the case of the application of the product according to the present invention for the hydrophobic coating of rearview mirrors, in terms of volatility (evaporation rate), A+ is "excellent"; A is "good"; B is "unacceptable"; and C is "poor".

[0129] Transparency test

[0130] A clean mirror with dimensions of 8cm × 10cm was selected as the test substrate. The glass treatment composition to be tested was evenly sprayed onto the mirror surface using a spray device, ensuring that the composition completely covered the entire mirror surface, and left to stand for 10 minutes. Then, the appearance of the treated mirror and an untreated mirror of the same size was compared, and the differences in appearance were observed under the following four environmental conditions: normal environment without strong light; normal environment with strong light; nighttime environment without strong light; nighttime environment with strong light.

[0131] Evaluation criteria:

[0132] Based on the appearance comparison results under different environments, the following criteria are used for scoring:

[0133] A+: The appearance of the treated mirror is completely consistent with that of the untreated mirror in all four of the above environments;

[0134] A: I can feel that there is a coating on the mirror, but it does not affect the view in any of the four environments mentioned above;

[0135] B: I can feel that there is a coating on the mirror. It does not affect vision in normal light and at night, but it does affect vision in normal light and at night.

[0136] C: A coating can be felt on the mirror surface, and it affects vision in all four of the above environments.

[0137] In the application of the product according to the present invention for the hydrophobic coating of rearview mirrors, in terms of transparency, A+ is "excellent"; A is "good"; B is "unacceptable"; and C is "poor".

[0138] Example 1 (E1)

[0139] Solvent oil D20 was added to a container, followed by hydrophobically modified fumed silica particles R106. The mixture was stirred using a homogenizer at 3000-4000 rpm to obtain a solvent oil dispersion of hydrophobically modified nano-silica. Then, quaternary ammonium salt DC5700 was added to the solvent oil dispersion and stirred until completely mixed to obtain the final glass treatment composition 1.

[0140] The glass treatment composition 1 comprises 1% by weight of hydrophobically modified fumed silica particles R106, 0.1% by weight of quaternary ammonium salt DC5700 and 98.9% by weight of solvent oil D20, as shown in Table 2 below.

[0141] Then, according to the test methods for hydrophobicity, durability, volatility (evaporation rate) and transparency described in detail above, the glass treatment composition 1 prepared in Example 1 was subjected to hydrophobicity, durability, volatility (evaporation rate) and transparency, respectively, and the results are shown in Table 2 below.

[0142] Examples 2-8 (E2-E8) and Comparative Examples 1-6 (CE1-CE6)

[0143] Glass treatment compositions 2-8 and comparative glass treatment compositions 1-6 were prepared in a manner similar to that of Example 1 above, except that the types and / or proportions of raw materials were changed as shown in Table 2 below.

[0144] In Comparative Example 2, a comparative glass treatment composition 2 was prepared in a manner similar to that of Example 1 above, except that amino silicone oil was used instead of quaternary ammonium salt DC5700.

[0145] Then, according to the test methods for hydrophobicity, durability, volatility (evaporation rate) and transparency described in detail above, the glass treatment compositions 2-8 and comparative glass treatment compositions 1-6 prepared in Examples 2-8 (E2-E8) and Comparative Examples 1-6 (CE1-CE6) were tested for hydrophobicity, durability, volatility (evaporation rate) and transparency, respectively, and the results are shown in Table 2 below.

[0146] Table 2 shows the component ratios and performance test results of the glass treatment compositions prepared in Examples 1-8 (E1-E8) and Comparative Examples 1-6 (CE1-CE6).

[0147]

[0148] As can be seen from the data shown in Table 2, the glass treatment composition having a specific composition within the scope of the present invention simultaneously possesses good hydrophobicity, durability, volatility (evaporation rate), and transparency. This solves the problem of insufficient hydrophobicity leading to raindrop residue or good hydrophobicity but poor transparency, effectively improving the visibility of automotive rearview mirror glass in rainy weather and meeting practical usage needs.

[0149] Specifically, Examples 1 (E1) through 6 (E6) and 8 (E8) used R106 with an average particle size of 7 nm, while Example 7 (E7) used R972 with an average particle size of 12 nm. All of these particles achieved an A+ level of hydrophobicity and an A or A+ level of transparency. This verifies that particles in the 7-12 nm particle size range can enhance hydrophobicity through a microscopic rough structure, while simultaneously reducing light scattering and ensuring transparency due to their particle size being much smaller than the visible light wavelength (400-760 nm).

[0150] Comparative Example 1 (CE1) used 14 nm H17 particles. Although the hydrophobicity reached the A+ level, the transparency dropped to the B level. Unbound from theory, it is believed that the reason is that 14 nm particles are close to the short-wavelength limit of visible light, which easily causes slight light scattering, resulting in increased coating haze, proving that particle size exceeding 12 nm will destroy transparency.

[0151] Examples 1 (1 wt% hydrophobic silica particle content), 3 (2 wt% hydrophobic silica particle content), 4 (0.1 wt% hydrophobic silica particle content), and 5 (0.5 wt% hydrophobic silica particle content) all fall within the range of 0.1-2 wt%, and all exhibit A+ hydrophobicity. Specifically, E1, E3, and E5 with a content of 0.5-2 wt% achieve A+ durability, while E4 with a content of 0.1 wt% achieves A durability. This indicates that higher particle content (0.5-2 wt%) can form a more continuous hydrophobic layer, improving erosion resistance.

[0152] In Comparative Example 5 (CE5), the content of hydrophobic silica particles was 0.09% by weight (less than 0.1% by weight), the hydrophobicity dropped to Grade A, and the durability was only Grade B. It was not bound by theory and was believed to be easily dispersed by water flow because the particles could not form a complete hydrophobic layer. In Comparative Example 6 (CE6), the content of hydrophobic silica particles was 2.5% by weight (more than 2% by weight), the hydrophobicity was Grade A+, but the transparency dropped to Grade B. It was not bound by theory and was believed to be due to the agglomeration of excessive particles leading to increased light scattering.

[0153] Examples 1-8 all contain 0.01-0.1% by weight of quaternary ammonium salt, achieving an A+ level of hydrophobicity and an A or A+ level of durability. Unbound by theory, it is believed that quaternary ammonium salts enhance coating adhesion by forming covalent bonds with hydroxyl groups on the glass surface through siloxy groups, while long-chain alkyl groups synergistically improve hydrophobicity. For example, a comparison between Example 1 (E1) (0.1% by weight DC5700) and Example 8 (E8) (0.1% by weight LS-8012) shows that when R is octadecyl, the durability (A+) is superior to that of dodecyl (A), because the longer alkyl chain enhances intermolecular forces and improves erosion resistance.

[0154] Comparative Example 2 (CE2) used amino silicone oil instead of quaternary ammonium salt, resulting in a decrease in hydrophobicity to grade B and durability to grade B only. Unbound by theory, it is believed that although amino silicone oil contains hydrophobic groups, it cannot form covalent bonds with glass, resulting in poor coating adhesion, and the silicone oil molecules are easily washed away by rainwater. These results demonstrate that quaternary ammonium salt is the key component for ensuring both hydrophobicity and durability.

[0155] The durability of Example 1 (quaternary ammonium salt content of 0.1 wt%) and Example 5 (quaternary ammonium salt content of 0.05 wt%) was A+, while the durability of Comparative Example 5 (CE5) was reduced to B due to the quaternary ammonium salt content of 0.009 wt% (less than 0.01 wt%). This is not theoretically constrained and is believed to be due to the insufficient covalent bonding formed by the low quaternary ammonium salt content, which makes the coating prone to peeling.

[0156] The evaporation rates of Example 1 (D20, flash point 20℃) and Example 2 (D10, flash point 10℃) were both A+ grade (<5 minutes), while the evaporation rate of Example 6 (D40, flash point 40℃) was A grade (5-10 minutes), which meets the design expectation of a flash point range of 10-40℃. These solvent oils have moderate vapor pressure, allowing for rapid evaporation and promoting uniform film formation of the components.

[0157] Comparative Example 3 (CE3, D60, flash point 60°C) and Comparative Example 4 (CE4, D80, flash point 80°C) both exceeded the upper limit of 40°C, and their evaporation rates dropped to Class B (10-30 minutes) and Class C (>30 minutes), respectively. They were not bound by theory and it is believed that the coating sagging was caused by the slow evaporation of the solvent, and even the residual solvent damaged the hydrophobic structure.

[0158] Examples 1-8 used solvent oils (D10, D20, D40) with flash points of 10-40℃, and the transparency of all of them reached A or A+ grade. Because these solvents have good compatibility with particles and quaternary ammonium salts, they can reduce agglomeration. However, Comparative Examples 3 and 4 had secondary agglomeration of particles due to the residue of high flash point solvents. Although the transparency was still A grade, the evaporation rate defect made them unsuitable for practical use.

[0159] The overall performance (hydrophobicity A+, durability A / A+, evaporation rate A / A+, transparency A / A+) of Examples 1-8 is significantly better than that of the comparative examples, confirming the synergistic effect of "7-12 nm hydrophobic silica particles + 0.01-0.1% by weight quaternary ammonium salt + 10-40℃ flash point solvent oil". Unbound by theory, it is believed that the hydrophobic silica particles provide a hydrophobic microstructure, the quaternary ammonium salt enhances adhesion and synergistically promotes hydrophobicity, and the solvent oil ensures dispersion and rapid film formation. These three elements work synergistically to achieve a performance balance of "hydrophobicity-transparency-drying". The comparative examples, due to deviations from any key parameter (such as excessive particle size, excessive content, lack of quaternary ammonium salt, or excessively high solvent flash point), resulted in at least one performance degradation, failing to meet the actual usage requirements of automotive rearview mirrors.

[0160] Although specific embodiments have been shown and described herein, those skilled in the art will understand that various alternative and / or equivalent embodiments can be used instead of the shown and described specific embodiments without departing from the scope of the invention. This application is intended to include any improvements or modifications to the specific embodiments discussed herein. Those skilled in the art will understand that various modifications and changes can be made without departing from the scope of the invention. Such modifications and changes are intended to fall within the scope of the invention as defined in the appended claims.

Claims

1. A glass treatment composition, said glass treatment composition comprising, based on its total weight: 0.1-2% by weight of hydrophobic silica particles with an average particle size of 7-12 nm; 0.01-0.1% by weight of quaternary ammonium salts; and Solvent oils with a flash point in the range of 10-40℃, comprising 97.9-99.89% by weight; The quaternary ammonium salt has a structure represented by the following general formula (I): General Formula (I) Where R is C 12 -C 18 alkyl.

2. The glass treatment composition according to claim 1, wherein the hydrophobic silica particles are silica particles with a surface hydrophobic treatment.

3. The glass treatment composition according to claim 1, wherein the hydrophobic silica particles are silica particles whose surface has been treated with a silane coupling agent or a siloxane.

4. The glass treatment composition according to claim 3, wherein the silane coupling agent is selected from one or more of the group consisting of: trimethylethoxysilane, trimethylchlorosilane, propyldimethylchlorosilane, 3-glycidoxypropyltrimethoxysilane, octyltrichlorosilane, octadecyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

5. The glass treatment composition according to claim 3, wherein the siloxane is selected from one or more of the group consisting of: octamethylcyclotetrasiloxane, polydimethylsiloxane, hexamethyldisiloxane, 1,3-dibutyltetramethyldisiloxane, hexaethyldisiloxane, and 3-(1,2-epoxypropoxy)propylpentamethyldisiloxane.

6. The glass treatment composition according to claim 1, wherein the glass treatment composition comprises 0.5-2% by weight of the hydrophobic silica particles.

7. The glass treatment composition according to claim 1, wherein in general formula (I), R is C 12 -C 18 Straight-chain alkyl groups.

8. The glass treatment composition according to claim 1, wherein in general formula (I), R is C 15 -C 18 Straight-chain alkyl groups.

9. The glass treatment composition according to claim 1, wherein in general formula (I), R is n-dodecyl or n-octadecyl.

10. The glass treatment composition according to claim 1, wherein the glass treatment composition comprises 0.05-0.1% by weight of the quaternary ammonium salt.

11. The glass treatment composition according to claim 1, wherein the flash point of the solvent oil is in the range of 10-20°C.

12. The glass treatment composition according to claim 1, wherein the solvent oil with a flash point in the range of 10-40°C contains C 6-12 hydrocarbon.

13. The glass treatment composition according to claim 1, wherein the glass treatment composition further comprises C1-C3 alcohols.

14. The glass processing composition according to claim 13, wherein the C1-C3 alcohol is selected from one or more of the group consisting of methanol, ethanol, n-propanol and isopropanol.

15. The glass treatment composition according to claim 1, wherein the glass treatment composition further comprises one or more of an antioxidant and a toughening agent.

16. The glass treatment composition according to claim 1, wherein the glass treatment composition is an automotive rearview mirror glass treatment composition.

17. A method for preparing a glass treatment composition according to any one of claims 1-16, the method comprising uniformly mixing the components.

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