Anti-icing coating for vehicles and method for preparing the same

Abstract

The application discloses a kind of anti-icing coating for vehicle and preparation method thereof, with primer and topcoat, it is characterized in that, preparation raw material composition is as follows according to mass percentage: primer: anti-icing dispersion 15~25%, hydroxyl acrylic resin emulsion 40~55%, curing agent 15~25%, the rest is water;Topcoat: anti-icing dispersion 45~55%, ethanol 3~5%, the rest is water;Wherein, the raw material composition of the anti-icing dispersion is: micron grade MoS2 / WS2 mixture 16~24%, nanometer grade MoS2 / WS2 mixture 3~8%, silica sol 35~45%, organosiloxane 0.5~1.5%, auxiliary agent 1~1.5%, the rest is water.The application can improve the hydrophobic and icephobic performance of coating film with silica sol and nanometer-micron structure MoS2 / WS2 synergistic as main icephobic carrier, with higher hardness, good adhesion to glass, can adapt to the repeated washing of rain wiper on coating film, suitable for vehicle glass use.

Description

Technical Field

[0001] This invention relates to a water-based coating, specifically to an anti-icing coating for automobiles, and particularly to a transparent inorganic anti-icing coating for automotive glass. Background Technology

[0002] In winter, during rainy or snowy weather, vehicles are often covered in snow or have ice on their surfaces. Before using the vehicle, it is essential to remove the ice and snow from the windshields to ensure visibility.

[0003] Currently, de-icing methods for civilian vehicles mainly include the following: heating de-icing, which involves turning on the vehicle's air conditioning or heating the glass with a heating element to melt and remove the ice and snow; physical de-icing, which involves directly removing the ice and snow using tools such as ice scrapers; and de-icing agent de-icing, which involves spraying de-icing agent onto the ice surface and waiting for the ice and snow to melt naturally over time. These methods all have some effectiveness, but each also has its drawbacks. Heating de-icing is time-consuming and usually cannot efficiently cover the side windows; direct removal with tools is very difficult if it involves de-icing or melted and re-frozen snow, as the ice layer adheres strongly to the glass; and using de-icing agents requires a large amount of material and a long time to allow the ice to melt slowly from the outside in when the vehicle has a large iced area and a thick ice layer, and the effectiveness decreases as the temperature drops.

[0004] Icing-repellent or anti-icing materials are mostly used in large equipment such as power equipment, wind turbine blades, and ships, and are less commonly used in civilian applications. Furthermore, icing-repellent and hydrophobic properties are often linked; however, they are not equivalent, especially in terms of durability. While hydrophobic materials generally also have good icing-repellent properties, the dendrite growth process during icing can damage the hydrophobic / icing-repellent layer, and an overly rough hydrophobic layer can also increase the adhesion strength of the ice layer. In addition, when used in automotive glass, especially windshields, the coating is required to have good wash resistance, ensuring it continues to function normally even after repeated wiper cycles.

[0005] Chinese invention patent CN10864882A discloses a self-lubricating anti-icing coating. It adds an anti-icing lubricant to a modified acrylic resin and uses a polyisocyanate curing agent as component B to provide a self-lubricating effect on the surface after film formation. The anti-icing lubricant can be one or more of molybdenum disulfide, flake graphite, fluorinated graphite, paraffin wax, etc. This coating is applied to tinplate or low-carbon steel plates (see paragraphs 0019 and 0020 of the specification) and can form an anti-icing coating with good self-lubricating effect. However, this solution utilizes the lubricity of the anti-icing lubricant to form the anti-icing surface of the coating, which is not suitable for automotive glass. For example, when using molybdenum disulfide, although it can also have a low coefficient of friction and provide certain hydrophobic and anti-icing properties, its Mohs hardness is only 1-1.5. In working environments requiring repeated washing or frequent external force application to the coating, its durability is not ideal, leading to problems such as the coating cracking or a significant decrease in hydrophobic and anti-icing properties after a period of use.

[0006] Therefore, it is necessary to develop a coating suitable for automotive glass that has anti-icing properties and can still prevent icing even after repeated wiping by the wipers. Summary of the Invention

[0007] The objective of this invention is to provide an anti-icing coating for automotive glass, which can easily remove ice and snow covering vehicle windows. Another objective of this invention is to provide a method for preparing this coating.

[0008] To achieve the above-mentioned objectives, the technical solution adopted by this invention is: an anti-icing coating for automobiles, comprising a primer and a topcoat, wherein the raw material composition by mass percentage is as follows:

[0009] Primer: 15-25% anti-icing dispersion, 40-55% hydroxyl acrylic resin emulsion, 15-25% curing agent, and the balance being water;

[0010] Topcoat: 45-55% anti-icing dispersion, 3-5% ethanol, balance water;

[0011] The raw material composition of the anti-icing dispersion is as follows:

[0012] The mixture consists of 16-24% micron-sized MoS2 / WS2 mixture, 3-8% nano-sized MoS2 / WS2 mixture, 35-45% silica sol, 0.5-1.5% organosiloxane, 1-1.5% additives, and the balance being water.

[0013] In the above technical solution, the micron-sized MoS2 / WS2 mixture is a mixture of 10-20 μm MoS2 and WS2 in a mass ratio of 1:0.2-0.3, and the nano-sized MoS2 / WS2 mixture is a mixture of 50-80 nm MoS2 and WS2 in a mass ratio of 1:0.2-0.3.

[0014] The silica sol has a solid content of 28-32%, a pH value of 9-10, and an average particle size of 8-25 nm.

[0015] The organosiloxane is n-octyltriethoxysilane or heptadecafluorodecyltrimethoxysilane.

[0016] The hydroxyl acrylic emulsion has a solid content of 48-50% and a hydroxyl content of 2.8-4.0% based on solid content.

[0017] The curing agent is a water-dispersible isocyanate curing agent with an NCO content of 18-23%.

[0018] The additives include 2-amino-2-methyl-1-propanol, wetting agents, dispersants, and defoamers.

[0019] To achieve another objective of this invention, this invention provides a method for preparing an anti-icing coating for automobiles, comprising the following steps:

[0020] I. Preparation of anti-icing dispersion:

[0021] S1. Add water, micron-sized MoS2 / WS2 mixture, nano-sized MoS2 / WS2 mixture, and some additives to a container and disperse to obtain a homogeneous slurry;

[0022] S2. Add silica sol to the slurry obtained in S1, stir evenly, and then reflux and heat to the reaction temperature while stirring. Add organosiloxane at a uniform rate and continue to reflux and heat while stirring.

[0023] S3. Stop heating the slurry obtained in S2 while stirring and refluxing, add the remaining additives, let it cool naturally to room temperature, stop stirring, and obtain the anti-icing dispersion;

[0024] II. Preparation of primer:

[0025] The anti-icing dispersion obtained in step one is mixed evenly with the hydroxyl acrylic resin emulsion to obtain component A of the primer, and the curing agent is component B of the primer.

[0026] III. Preparation of Topcoat:

[0027] Mix the anti-icing dispersion obtained in step one, ethanol, and water evenly to obtain the topcoat.

[0028] In the preferred embodiment, step S1 involves two steps: stirring dispersion and ultrasonic dispersion. The stirring dispersion is performed at a speed of 1200–1400 rpm for 30–40 minutes, and the ultrasonic dispersion is performed for 30–40 minutes.

[0029] In step S2, the reaction temperature is 45-50°C, the stirring speed is 400-600 rpm, the organosiloxane dropwise addition time is controlled at 20-25 minutes, and after the dropwise addition is completed, the reaction continues for 50-60 minutes.

[0030] In step S3, the stirring speed is 300-400 rpm.

[0031] In the preferred embodiment, the additives added in step S1 are wetting agents and dispersants, and the additives added in step S3 are 2-amino-2-methyl-1-propanol (to adjust pH value) and defoamers.

[0032] To ensure the effectiveness of this invention, when applying the primer, first mix components A and B manually for 5-10 minutes until fully mixed, and then complete the application within 1 hour, controlling the wet film thickness to 120-150 μm. Within 2 hours after the primer is surface dry, apply the topcoat by spraying to ensure better adhesion between the topcoat and primer, controlling the wet film thickness to 50-80 micrometers to ensure substrate light transmittance and proper topcoat film formation, and to prevent partial peeling of the topcoat layer during use.

[0033] Due to the application of the above-mentioned technical solution, the present invention has the following advantages compared with the prior art:

[0034] 1. This invention incorporates a mixture of micron-sized MoS2 / WS2 and a mixture of nano-sized MoS2 / WS2, using silica sol and the nano-micron structured MoS2 / WS2 synergistically as the main ice-repellent carrier. This carrier has low surface energy and intrinsic hydrophobic / ice-repellent properties. The combined use of micron-sized and nano-sized materials ensures that MoS2 / WS2 retains this size structure after reacting with silica sol. The coating surface has a dual microstructure with alternating or overlapping micron-nano structures, which mimics the hydrophobic structure of surfaces such as lotus leaves and insect wings, thus improving the hydrophobic and ice-repellent properties of the coating. In addition, appropriate roughness allows the coating to retain an air cushion when in contact with water, providing a buffer space for ice crystal growth when water droplets freeze, reducing the risk of the coating being punctured by ice crystals.

[0035] 2. This invention significantly improves the dispersion effect of MoS2 and WS2 by blending silica sol, organosiloxane, and MoS2 / WS2, especially by changing the stacking structure of the particles after the coating film dries, resulting in a high level of hydrophobic and ice-repellent properties after the coating film dries. In addition to retaining the low coefficient of friction of MoS2 / WS2, the coating film also has high hardness, so the coating film still has a long service life under repeated daily cleaning and repeated washing by windshield wipers.

[0036] 3. In this invention, the mixing of MoS2 / WS2 does not reduce the direct friction of the icing surface, but rather reduces the friction between fillers in the coating, lowers the coating viscosity, reduces the water content in the coating, and increases the film strength of the coating, thus significantly improving the friction resistance of the coating. At the same time, the combined use of micron and nano materials can also improve the strength of the coating. When micron-sized particles are stacked, there will be gaps, which will reduce the strength. Nano-sized particles can fill the gaps in the micron-sized particles, increasing the density.

[0037] 4. The mixture of MoS2 / WS2 also has a high thermal conductivity. When used on glass surfaces, it can not only suppress icing but also improve the efficiency of heating and de-icing.

[0038] 5. The anti-icing coating for vehicles provided by this invention cures at room temperature. In an environment of 25°C and 50% relative humidity, the coating film can reach the working performance requirements 48 hours after the topcoat is applied. The coating is thin, has good light transmittance, and has good adhesion to glass. Implementation

[0039] The present invention will be further described below with reference to embodiments:

[0040] Example 1: A method for preparing an anti-icing coating for vehicles, comprising the following steps:

[0041] I. Preparation of anti-icing dispersion:

[0042] S1. Add 36.45 parts by mass of water, 0.2 parts by mass of wetting agent WE3650 (BASF), 0.5 parts by mass of dispersant Dispers 740W (Evonik), 18 parts by mass of micron-sized MoS2 / WS2 mixed at a mass ratio of 1:0.2, wherein the MoS2 (Yumu New Materials) particle size is 10-15μm and the mass fraction is 99.9%, and the WS2 (Yumu New Materials) particle size is 15-20μm and the mass fraction is 99.9%, and 8 parts by mass of nano-sized MoS2 / WS2 mixed at a mass ratio of 1:0.25, wherein the MoS2 (Zhejiang Manli) particle size is 50-60nm and the mass fraction is 99.9%, and the WS2 (Zhejiang Manli) particle size is 65-75nm and the mass fraction is 99.9%, and disperse at 1400 rpm for 40 minutes to obtain a homogeneous slurry;

[0043] S2. The slurry obtained in S1 is ultrasonically dispersed for 30 minutes;

[0044] S3. Add 35 parts by mass of silica sol LS-30 (Zhejiang Yuda Chemical) to the slurry obtained in S2. The slurry has a solid content of 30.1%, a pH value of 9.6, and an average particle size of 12 nm. Stir the mixture at 450 rpm until homogeneous. Then, maintain the stirring speed and reflux the mixture to 45°C and maintain the temperature at 45~50°C. Add 1.5 parts by mass of organosiloxane n-octyltriethoxysilane A-137 (Momentive) at a uniform rate. The effective content of the organosiloxane is 98%. After the addition is completed in 25 minutes, continue to reflux the mixture with stirring for 60 minutes.

[0045] S4. Stop heating the slurry obtained in S3 while stirring and refluxing, and add 0.15 parts by weight of 2-amino-2-methyl-1-propanol (Angus) and 0.2 parts by weight of defoamer TEGO Foamex 825 (Evonik) while maintaining a speed of 300 rpm. Allow it to cool naturally to room temperature, then stop stirring to obtain an anti-icing dispersion.

[0046] II. Primer Preparation:

[0047] 40 parts by mass of hydroxyl acrylic resin emulsion Archsol 8576 (Wanhua Chemical), 25 parts by mass of the above-mentioned anti-icing dispersion, and 18.3 parts by mass of water were mixed evenly as primer component A. 16.7 parts by mass of curing agent Aquolin269 (Wanhua Chemical), with an NCO content of 19%, were packaged separately as primer component B.

[0048] III. Preparation of Topcoat:

[0049] 40 parts by mass of the above-mentioned anti-icing dispersion, 3 parts by mass of ethanol (Nantong Yaoxin Chemical Co., Ltd.) with a mass fraction of 95%, and 57 parts by mass of water were mixed evenly to obtain a transparent inorganic anti-icing coating topcoat for automobiles.

[0050] Usage test:

[0051] Mix components A and B of the primer and stir manually for 10 minutes until fully and evenly mixed. Apply the mixture to tempered glass by spraying to achieve a wet film thickness of 120 μm. After surface drying, immediately spray the topcoat to achieve a wet film thickness of 80 μm. After curing for 48 hours at 25±1℃ and 50±2% relative humidity, the adhesion is rated as grade 0 using the cross-cut adhesion test in GB / T 9286. The shear strength of the glass against ice is 13 kPa, as tested using the method in GB / T 33334. After 50,000 washes using the method in GB / T 9266, the shear strength against ice is 22 kPa.

[0052] Example 2: A method for preparing an anti-icing coating for vehicles, comprising the following steps:

[0053] I. Preparation of anti-icing dispersion:

[0054] S1. Add 25 parts by mass of water, 0.3 parts by mass of wetting agent WSS713 (Wuseshi New Materials), 0.7 parts by mass of dispersant Dispers 740W (Evonik), 24 parts by mass of micron-sized MoS2 / WS2 mixed at a mass ratio of 1:0.3, wherein the MoS2 (Shanghai Naio Nano) particle size is 10-15μm and the mass fraction is 99.9%, and the WS2 (Shanghai Naio Nano) particle size is 10-15μm and the mass fraction is 99.9%, and 4 parts by mass of nano-sized MoS2 / WS2 mixed at a mass ratio of 1:0.3, wherein the MoS2 (Bohuasi Nano) particle size is 50-60nm and the mass fraction is 99.9%, and the WS2 (Bohuasi Nano) particle size is 50-60nm and the mass fraction is 99.9%, and disperse at 1200 rpm for 30 minutes to obtain a homogeneous slurry;

[0055] S2. The slurry obtained in S1 is ultrasonically dispersed for 40 minutes;

[0056] S3. Add 45 parts by mass of silica sol CH83-130 (Jiangsu Guolian) to the slurry obtained in S2. The sol has a solid content of 30.0%, a pH of 9.9, and an average particle size of 19 nm. Stir at 550 rpm until homogeneous, then reflux and heat to 45°C while maintaining the stirring speed. Maintain the temperature at 45-50°C. Add 0.5 parts by mass of heptadecafluorodecyltrimethoxysilane KH-1713 (Hangzhou Jessica) at a uniform rate. The mass fraction of the added sol is 97%. After the addition is completed in 20 minutes, continue to reflux and heat for 50 minutes while stirring.

[0057] S4. Stop heating the slurry obtained in S3 while stirring and refluxing, and add 0.2 parts by mass of 2-amino-2-methyl-1-propanol (Angus) and 0.3 parts by mass of defoamer Foamstar ST 2410 (BASF) while maintaining a speed of 400 rpm. Allow it to cool naturally to room temperature, then stop stirring to obtain the anti-icing dispersion.

[0058] II. Primer Preparation:

[0059] 52 parts by mass of Archsol 8563 (Wanhua Chemical), a hydroxyl acrylic resin emulsion with a solid content of 50% and a hydroxyl content of 3.8%, 23 parts by mass of the above-mentioned anti-icing dispersion, and 1.4 parts by mass of water were mixed evenly as primer component A. 23.6 parts by mass of Aquolin 278 (Wanhua Chemical), a curing agent with an NCO content of 22%, were separately packaged as primer component B.

[0060] III. Preparation of Topcoat:

[0061] 55 parts by mass of the above-mentioned anti-icing dispersion, 5 parts by mass of ethanol (Nantong Yaoxin Chemical Co., Ltd.) with a mass fraction of 95%, and 40 parts by mass of water were mixed evenly to obtain a transparent inorganic anti-icing coating topcoat for automobiles.

[0062] test:

[0063] Mix components A and B of the primer and stir manually for 10 minutes until fully and evenly mixed. Apply the mixture to tempered glass by spraying to achieve a wet film thickness of 150 μm. After surface drying, immediately spray the topcoat to achieve a wet film thickness of 50 μm. After curing at 25±1℃ and 50±2% relative humidity for 48 hours, the adhesion is tested using the cross-cut test in GB / T 9286, and the adhesion is grade 0. The shear strength of the glass against ice is tested using the method in GB / T 33334, and the shear strength against ice is 10 kPa after 50,000 washes using the method in GB / T 9266, and the shear strength against ice is 18 kPa.

[0064] To verify the effectiveness of the present invention, a comparative experiment was conducted:

[0065] Commercially available single-component (commercially available 1) and two-component (commercially available 2) anti-icing coatings were selected and sprayed onto tempered glass according to the instructions, with a wet film thickness of 120 μm. After sufficient curing time, the coatings were compared with Examples 1 and 2, and adhesion was tested using the cross-cut test method in GB / T 9286. The shear strength of the glass against ice was tested using the method in GB / T 33334, and after 50,000 washes using the method in GB / T 9266, the shear strength of the glass against ice was tested again. The results are shown in Table 1. The comparison results show that Examples 1 and 2 are more targeted at automotive glass. The adhesion of the single-component commercially available 1 and the two-component commercially available 2 anti-icing coatings on glass is not ideal. Commercially available 1 has poor washability and is not suitable for environments with frequent washing. Although commercially available 2 has good washability, its anti-icing performance decreases significantly after repeated washing, making it unsuitable for automotive glass, especially windshields. In contrast, Examples 1 and 2 of the present invention not only have good adhesion to tempered glass but also good anti-icing performance, and their anti-icing performance does not decrease significantly after repeated washing.

[0066] Table 1 Performance Test Comparison

[0067] .

Claims

1. An anti-icing coating for automobiles, comprising a primer and a topcoat, characterized in that, The raw material composition, by mass percentage, is as follows: Primer: 15-25% anti-icing dispersion, 40-55% hydroxyl acrylic resin emulsion, 15-25% curing agent, and the balance being water; Topcoat: 45-55% anti-icing dispersion, 3-5% ethanol, balance water; The raw material composition of the anti-icing dispersion is as follows: The mixture comprises 16-24% micron-sized MoS2 / WS2 mixture, 3-8% nano-sized MoS2 / WS2 mixture, 35-45% silica sol, 0.5-1.5% organosilane, 1-1.5% additives, and the balance being water. The organosilane is n-octyltriethoxysilane or heptadecafluorodecyltrimethoxysilane.

2. The anti-icing coating for vehicles according to claim 1, characterized in that: The micron-sized MoS2 / WS2 mixture is a mixture of 10-20 μm MoS2 and WS2 in a mass ratio of 1:0.2-0.3, and the nano-sized MoS2 / WS2 mixture is a mixture of 50-80 nm MoS2 and WS2 in a mass ratio of 1:0.2-0.

3.

3. The anti-icing coating for vehicles according to claim 1, characterized in that: The silica sol has a solid content of 28-32%, a pH value of 9-10, and an average particle size of 8-25 nm.

4. The anti-icing coating for vehicles according to claim 1, characterized in that: The hydroxyl acrylic resin emulsion has a solid content of 48-50%, and the hydroxyl content, calculated as solid content, is 2.8-4.0%.

5. The anti-icing coating for vehicles according to claim 1, characterized in that: The curing agent is a water-dispersible isocyanate curing agent with an NCO content of 18-23%.

6. The anti-icing coating for vehicles according to claim 1, characterized in that: The additives include wetting agents, dispersants, and defoamers.

7. The anti-icing coating for vehicles according to claim 6, characterized in that: The adjuvant includes 2-amino-2-methyl-1-propanol.

8. The preparation method of the automotive anti-icing coating according to claim 1, comprising the following steps: I. Preparation of anti-icing dispersion: S1. Add water, micron-sized MoS2 / WS2 mixture, nano-sized MoS2 / WS2 mixture, and some additives to a container and disperse to obtain a homogeneous slurry; S2. Add silica sol to the slurry obtained in S1, stir evenly, and then reflux and heat to the reaction temperature while stirring. Add organosilane at a uniform rate and continue to reflux and heat while stirring. S3. Stop heating the slurry obtained in S2 while stirring and refluxing, add the remaining additives, let it cool naturally to room temperature, stop stirring, and obtain the anti-icing dispersion; II. Preparation of primer: The anti-icing dispersion, hydroxyl acrylic resin emulsion and water obtained in step one are mixed evenly to obtain component A of the primer, and the curing agent is component B of the primer. III. Preparation of Topcoat: Mix the anti-icing dispersion obtained in step one, ethanol, and water evenly to obtain the topcoat.

9. The method for preparing the automotive anti-icing coating according to claim 8, characterized in that: In step S1, the dispersion consists of two steps: stirring dispersion and ultrasonic dispersion. The stirring dispersion speed is 1200-1400 rpm and the time is 30-40 minutes. The ultrasonic dispersion time is 30-40 minutes. In step S2, the reaction temperature is 45-50°C, the stirring speed is 400-600 rpm, the organosilane dropwise addition time is controlled at 20-25 minutes, and after the dropwise addition is completed, the reaction continues for 50-60 minutes. In step S3, the stirring speed is 300-400 rpm.