High-adhesion wear-resistant automobile windshield wiper rubber strip water-based coating material and spraying process thereof

Abstract

The invention relates to a high-adhesion wear-resistant automobile windshield wiper rubber strip water-based coating material and a spraying process thereof, the high-adhesion wear-resistant automobile windshield wiper rubber strip water-based coating material comprises the following components by mass: 40-65 parts of a polyurethane prepolymer, the NCO content of the polyurethane prepolymer being 8-10%; the solid content of the acrylic resin is 40%-45%, and the glass transition temperature Tg of the acrylic resin is 65 DEG C; 3-8 parts of nano hexagonal boron nitride; 3-8 parts of forged aquadag; 5 to 10 parts of a water-based isocyanate cross-linking agent; 0.5 to 1.5 parts of a silane coupling agent; and 40 to 70 parts of deionized water. Through reasonable component design and a preparation process, the high-performance water-based coating material for the automobile windshield wiper rubber strip is provided, has high adhesive force, wear resistance and lubricity, is suitable for surface treatment of the automobile windshield wiper rubber strip, is used for surface coating of the automobile windshield wiper rubber strip, can effectively improve the wear resistance of a windshield wiper and prolong the service life of the windshield wiper, and has a good application prospect. Meanwhile, good adhesive force is kept.

Description

Technical Field

[0001] The present invention belongs to the field of automobiles, and particularly relates to a water-based coating material for a high-adhesion and wear-resistant automobile wiper rubber strip and a spraying process thereof. Background Art

[0002] Traditional wiper rubber strip coatings mostly adopt solvent-based formulations (such as styrene-butadiene rubber system 1), which have problems of VOCs emissions. Moreover, due to the lack of modification of graphite powder, its dispersibility is poor and the interfacial bonding is weak, resulting in insufficient adhesion, as shown in Chinese Patent CN112409907A; while the existing water-based polyurethane coatings are environmentally friendly, such as French Patent FR2921930, but have insufficient adhesion and their wear resistance is difficult to meet the relevant regulations of 500,000 times of scraping durability. Summary of the Invention

[0003] The purpose of the present invention is to provide a water-based coating material for a high-adhesion and wear-resistant automobile wiper rubber strip and a spraying process thereof.

[0004] To achieve the above purpose, the specific method is a water-based coating material for a high-adhesion and wear-resistant automobile wiper rubber strip, which comprises the following components in parts by mass:

[0005] 40-65 parts of polyurethane prepolymer, the NCO content of the polyurethane prepolymer is 8%-10%, and the molecular weight is 3000-5000;

[0006] 20-40 parts of acrylic resin, the solid content of the acrylic resin is 40%-45%, and the glass transition temperature Tg is 55-65°C;

[0007] 3-8 parts of nano hexagonal boron nitride, the particle size of the nano hexagonal boron nitride is 30-80nm;

[0008] 3-8 parts of forged graphite milk, the solid content of the forged graphite milk is 25%-35%;

[0009] 5-10 parts of water-based isocyanate crosslinking agent, the NCO content of the water-based isocyanate crosslinking agent is 8%-12%;

[0010] 0.5-1.5 parts of silane coupling agent;

[0011] 40-70 parts of deionized water.

[0012] Furthermore, the mass ratio of the polyurethane prepolymer to the acrylic resin is 1.5:1-2.5:1.

[0013] Furthermore, the forged graphite milk is stably suspended by a non-ionic dispersant.

[0014] The preparation method of the above-mentioned water-based coating material for a high-adhesion and wear-resistant automobile wiper rubber strip is as follows:

[0015] Step 1: Mix the polyurethane prepolymer and the acrylic resin at a shear rate of 1200 - 1800 rpm for 30 - 60 minutes to form a preliminary cross-linking of the hydrogen bond network;

[0016] Step 2: Ultrasonically disperse the nano hexagonal boron nitride and the silane coupling agent at 50 - 70 °C for 0.5 - 1.5 hours to form a modified lubricating phase; add forged graphite milk and continue stirring until evenly dispersed;

[0017] Step 3: Further add an aqueous isocyanate cross-linking agent and mix evenly.

[0018] Furthermore, the mass ratio of the surface-modified nano hexagonal boron nitride in Step 2 to the added forged graphite milk is 1:0.8 - 1.2.

[0019] Furthermore, the acrylic resin in Step 1 is preheated to 40 °C to reduce the viscosity.

[0020] Furthermore, in Step 1, the polyurethane prepolymer and the acrylic resin are mixed under nitrogen protection to prevent the hydrolysis of isocyanate groups.

[0021] Furthermore, the modified lubricating phase is formed in Step 2, and the surface hydroxyl density after modification is ≥ 3.5 per nm 2 , to enhance the interfacial bonding force with the resin.

[0022] Furthermore, the aqueous isocyanate cross-linking agent uses HDI trimer as the cross-linking agent, and the addition amount is 8 ± 0.5% of the total amount of the resin obtained in Step 1, and triggers the acrylic-polyurethane synergistic cross-linking at pH 7.2 ± 0.3.

[0023] The spraying process of the above high-adhesion wear-resistant automotive wiper rubber strip aqueous coating material:

[0024] Step 1: Form a primer layer, precoat an epoxy primer on the surface of the wiper rubber strip to form a primer layer, the thickness of the primer layer is 5 μm, the adhesion grade is 4B, and pre-bake at 80 - 90 °C for 5 minutes to remove surface bubbles;

[0025] Step 2: Main coating spraying, using high-pressure airless spraying, the pressure is 15 - 18 MPa, the nozzle diameter is 0.5 - 0.8 mm, the wet film thickness is 25 - 30 μm, and let it stand and level for 5 - 8 minutes after spraying;

[0026] Step 3: Curing, cure by hot air circulation at 80 °C for 15 minutes, the heating rate ≤ 5 °C / min, and the dry film thickness is 15 - 18 μm;

[0027] Step 4: Secondary curing. Spray an ethanol solution containing 0.5% silane coupling agent on the coating surface obtained in Step 3, and perform secondary curing at 120 - 130 °C for 5 minutes to form a hydrophobic protective layer. SEM shows that a continuous transition layer is formed at the interface between the coating and the substrate, the thickness of the continuous transition layer is about 1 μm, and the bonding strength ≥ 15 MPa ASTM D4541.

[0028] The coating material (coating) of the present invention has the following advantages:

[0029] High adhesion: Resin synergistic system: The polyurethane prepolymer and the acrylic resin form an interpenetrating network structure (IPN) through block polymerization, improving adhesion (1 - level cross - hatch method) and wear resistance (Taber abrasion ≤ 15 mg / 1000 cycles). Through the synergistic effect of the polyurethane prepolymer and the acrylic resin, a strong hydrogen - bond network is formed, enhancing the adhesion between the coating and the substrate.

[0030] Wear resistance: Composite lubricating phase design: After the surface modification of nano - hexagonal boron nitride (h - BN) with KH550 coupling agent, it is compounded with forged graphite emulsion to form a gradient lubricating layer, reducing the friction coefficient to 0.08 - 0.12 (superior to 0.15 - 0.25 of the traditional single lubricating system), and significantly improving the wear resistance of the coating.

[0031] Lubricity: The synergistic effect of the modified nano - hexagonal boron nitride and the forged graphite emulsion enhances the lubricating performance of the coating and prolongs the service life of the wiper rubber strip.

[0032] Environmental friendliness: Environment - friendly cross - linking process: Use an aqueous isocyanate cross - linking agent (NCO content 8% - 12%), avoiding solvent pollution, and shortening the curing time to 30 minutes (60 minutes for the traditional system). Reduce the use of organic solvents, meeting environmental requirements.

[0033] Through reasonable component design and preparation process, this patent provides a high - performance water - based coating material for automotive wiper rubber strips, which has high adhesion, wear resistance and lubricity, is suitable for the surface treatment of automotive wiper rubber strips, and can effectively improve the wear resistance and service life of the wiper, while maintaining good adhesion. Detailed implementation mode

[0034] Example 1

[0035] Prepare the following raw materials:

[0036] 40 parts of polyurethane prepolymer with an NCO content of 8.5% and a molecular weight of 3000 - 5000:

[0037] 40 parts of acrylic resin, the solid content of the polyurethane prepolymer is 45%, and the glass transition temperature Tg is 65 °C;

[0038] 8 parts of nano hexagonal boron nitride, with the particle size of the nano hexagonal boron nitride being 50 nm;

[0039] Forged graphite emulsion (solid content 30%, particle size 200 nm): 8 parts, stably suspended using a non-ionic dispersant (Triton X-100);

[0040] 10 parts of waterborne isocyanate crosslinking agent, with the NCO content of the waterborne isocyanate crosslinking agent being 8%; in this example, HDI trimer is used as the crosslinking agent;

[0041] 1.5 parts of silane coupling agent, which is KH550 coupling agent;

[0042] 70 parts of deionized water.

[0043] Preparation of coating material:

[0044] S1 Low-speed premixing: Preheat the acrylic resin to 40 °C to reduce its viscosity, and stir it with the polyurethane prepolymer at 40 °C and 1200 rpm for 30 minutes under nitrogen protection to form a preliminary crosslinking of the hydrogen bond network to prevent the hydrolysis of isocyanate groups;

[0045] S2 Lubricating phase treatment: Surface-modify the nano hexagonal boron nitride. Ultrasonically disperse the nano hexagonal boron nitride (h-BN) and KH550 coupling agent at 60 °C for 1 hour to form a lubricating phase. After being modified by the KH550 silane coupling agent, the surface hydroxyl density is ≥ 3.5 per nm 2 , enhancing the interfacial bonding force with the resin; then compound it with the forged graphite emulsion at a mass ratio of 1:1 and perform high-speed shearing at 5000 rpm for 15 minutes to form a uniform slurry (Brookfield viscosity ≤ 300 cP) to form a uniform suspension;

[0046] S3 Crosslinking and curing: Add HDI trimer as the crosslinking agent to achieve mixing, trigger the synergistic crosslinking of acrylic-polyurethane at pH 7.2 to obtain the waterborne coating material.

[0047] Spraying coating process:

[0048] Forming a primer layer: Precoat an epoxy primer (thickness 5 μm, adhesion grade 4B) on the surface of the windshield wiper rubber strip, and pre-bake it at 80 °C for 5 minutes to remove surface bubbles;

[0049] Spraying the main coating: Use high-pressure airless spraying (pressure 15 MPa, nozzle diameter 0.5 mm), with a wet film thickness of 25 μm, and let it stand for 5 minutes for leveling after spraying;

[0050] Curing: Cure it by hot air circulation at 80 °C for 15 minutes, with a heating rate ≤ 5 °C / min, and a dry film thickness of 15 - 18 μm (error ± 1 μm).

[0051] Secondary curing: Spray an ethanol solution containing 0.5% silane coupling agent on the surface of the cured coating, and perform secondary curing at 120 °C for 5 minutes to form a hydrophobic protective layer (contact angle ≥ 110°); complete the spraying.

[0052] Example 2

[0053] Material formulation

[0054] Polyurethane prepolymer: 50 parts, NCO content 9%, molecular weight 4000;

[0055] Acrylic resin: 30 parts, solid content 42%, glass transition temperature (Tg) 55 °C;

[0056] Nano hexagonal boron nitride: 5 parts, particle size 50 nm;

[0057] Forged graphite milk: 5 parts, solid content 30%, stably suspended with a non-ionic dispersant;

[0058] Waterborne isocyanate crosslinking agent: 7 parts, NCO content 10%;

[0059] Silane coupling agent: 1 part;

[0060] Deionized water: 55 parts;

[0061] Prepare the coating material:

[0062] S1 Low-speed premixing: Preheat the acrylic resin to 40 °C to reduce its viscosity, and stir it with the polyurethane prepolymer at 40 °C and 1500 rpm for 45 minutes under nitrogen protection to form a preliminary crosslinking of the hydrogen bond network to prevent the hydrolysis of isocyanate groups;

[0063] S2 Lubricating phase treatment: Surface-modify nano hexagonal boron nitride. Ultrasonically disperse nano hexagonal boron nitride (h-BN) with KH550 coupling agent at 60 °C for 1 hour to form a lubricating phase. After being modified with a silane coupling agent, the surface hydroxyl density ≥ 3.5 per nm 2 , improving the interfacial bonding force with the resin; then compound it with forged graphite milk at a mass ratio of 1:1.2 and perform high-speed shearing at 5000 rpm for 15 minutes to form a uniform slurry (Brookfield viscosity ≤ 300 cP) to form a uniform suspension;

[0064] S3 Crosslinking and curing: Add HDI trimer as a crosslinking agent to achieve mixing, and trigger acrylic-polyurethane synergistic crosslinking at pH 7.3 to obtain a waterborne coating material.

[0065] Refer to Example 1 for wiper spraying.

[0066] Example 3

[0067] Material formulation

[0068] Polyurethane prepolymer: 60 parts, NCO content is 8.5%, molecular weight is 4500;

[0069] Acrylic resin: 35 parts, solid content is 43%, glass transition temperature (Tg) is 65 °C;

[0070] Nano hexagonal boron nitride: 6 parts, particle size is 60 nm;

[0071] Forged graphite milk: 6 parts, solid content is 32%, stably suspended with non-ionic dispersant;

[0072] Waterborne isocyanate crosslinking agent: 8 parts, NCO content is 11%;

[0073] Silane coupling agent: 1.2 parts;

[0074] Deionized water: 60 parts.

[0075] Preparation of coating material:

[0076] S1 Low-speed premixing: Preheat the acrylic resin to 40 °C to reduce viscosity, and stir with the polyurethane prepolymer at 40 °C and 1800 rpm for 45 minutes under nitrogen protection to form a preliminary crosslinking of the hydrogen bond network to prevent hydrolysis of isocyanate groups;

[0077] S2 Lubricating phase treatment: Surface modification of nano hexagonal boron nitride, ultrasonic disperse nano hexagonal boron nitride (h-BN) and KH550 coupling agent at 65 °C for 1 hour to form a lubricating phase. After modification with silane coupling agent, the surface hydroxyl density ≥ 3.5 per nm 2 , improve the interfacial bonding force with the resin; then compound with forged graphite milk at a mass ratio of 1:0.8, and perform high-speed shearing at 5000 rpm for 15 minutes to form a uniform slurry (Brookfield viscosity ≤ 300 cP) to form a uniform suspension;

[0078] S3 Crosslinking and curing: Add HDI trimer as a crosslinking agent to achieve mixing, trigger acrylic-polyurethane synergistic crosslinking at pH 7.3 to obtain a waterborne coating material.

[0079] Spray the wiper according to Reference Example 1.

[0080] Example 4

[0081] Material formula

[0082] Polyurethane prepolymer: 45 parts, NCO content is 9.5%, molecular weight is 3500;

[0083] Acrylic resin: 25 parts, solid content is 41%, glass transition temperature (Tg) is 65 °C;

[0084] Nano hexagonal boron nitride: 4 parts, particle size of 40 nm;

[0085] Forged graphite milk: 4 parts, solid content of 28%, stably suspended with a non-ionic dispersant;

[0086] Waterborne isocyanate crosslinking agent: 6 parts, NCO content of 9%;

[0087] Silane coupling agent: 0.8 parts;

[0088] Deionized water: 50 parts.

[0089] Preparation of coating material:

[0090] S1 Low-speed premixing: Preheat the acrylic resin to 40 °C to reduce viscosity, and stir with the polyurethane prepolymer at 40 °C and 1400 rpm for 40 minutes under nitrogen protection to form preliminary crosslinking of the hydrogen bond network to prevent hydrolysis of the isocyanate groups;

[0091] S2 Lubricating phase treatment: Surface modification of nano hexagonal boron nitride, ultrasonically disperse nano hexagonal boron nitride (h-BN) with KH550 coupling agent at 55 °C for 1 hour to form a lubricating phase, and the surface hydroxyl density ≥ 3.5 per nm after modification with the silane coupling agent 2 , improving the interfacial bonding force with the resin; then compound with forged graphite milk at a mass ratio of 1:1, and perform high-speed shearing at 5000 rpm for 15 minutes to form a uniform slurry (Brookfield viscosity ≤ 300 cP) to form a uniform suspension;

[0092] S3 Crosslinking and curing: Add HDI trimer as a crosslinking agent to achieve mixing, trigger acrylic-polyurethane synergistic crosslinking at pH 7.0 to obtain a waterborne coating material.

[0093] Refer to Example 1 for wiper spraying.

[0094] Comparative Example 1

[0095] Traditional solvent-based wiper coating:

[0096]

[0097] Comparative Example 2

[0098] Fluorocarbon wiper coating

[0099]

[0100] Comparative Example 3

[0101] French Patent FR2921930 Coating

[0102] The above Examples 1-4 and Comparative Examples 1-3 were subjected to the following tests (observations) as follows:

[0103] 1. Adhesion grade test: The test was carried out according to ASTM D3359 specification; the test conditions were changed to test the adhesion and heat resistance change performance;

[0104] 2. Abrasion test: The test was carried out according to the Taber abrasion standard;

[0105] 3. Wear resistance life verification (500,000 cycles): CS-10 wheel wear test (1 kg load) was carried out;

[0106] 4. Dynamic friction coefficient test (reciprocating test): The test was carried out with a dynamic friction coefficient tester (DFT);

[0107] 5. Weather resistance test: Weather resistance (QUV 500 h), and the test was carried out with a QUV ultraviolet weathering test chamber;

[0108] 6. Measurement of VOC emission (g / L);

[0109] 7. Chemical resistance (immersed in 5% NaCl for 72 h);

[0110] 8. Heat resistance (-20°C to 80°C cycle 50 times);

[0111] 9. Curing time (80°C)

[0112] Table 1 Comparison of various performance indicators

[0113]

[0114] Examples 1-4 and Comparative Examples 1-3 were respectively observed for their performance in various aspects and tabulated:

[0115] Table 2 Comparative table of resin system innovation test

[0116]

[0117] Dual-resin synergy: Acrylic resin (low-temperature toughness) and polyurethane resin (chemical bonding) were compounded to form a hydrogen bond cross-linked network, and the interfacial bonding strength was increased to ≥5 MPa.

[0118] Breakthrough in weather resistance: Through the optimization of the resin ratio, the coating remained intact at a high temperature of 150°C, which was better than the heat resistance limit of 120°C of Comparative Example 2.

[0119] Examples 1-4 and Comparative Example 2 were observed through Taber friction test, ASTM D4060 test, and microstructure analysis:

[0120] Table 3 Advanced nature of nano-lubrication system

[0121]

[0122] The coefficient of friction (μ) is reduced by about 55%, the wear amount (mg / 1000 times) is reduced by about 60%, and the service life is extended by 2 times as seen from the continuity test of the lubricating layer;

[0123] Modification with nano - hexagonal boron nitride: Nano - hexagonal boron nitride (particle size < 100nm) modified by KH550 coupling agent through ultrasonic treatment forms a layered lubricating structure with graphite milk after surface hydroxylation, and the coefficient of friction is as low as 0.08 (0.15 in Comparative Document 2). ← Lubrication synergy effect: The compounding of forged graphite milk (3 - 5%) and nano - hexagonal boron nitride results in a wear amount that is only 50% of that of the commercially available graphite coating.

[0124] Observed through gas chromatography analysis, drying curve test, and chemical immersion test:

[0125] Table 4 Comparison of environmental protection and process advantage tests

[0126]

[0127]

[0128] Replacement with aqueous system: Deionized water solvent replaces xylene, and the VOC emission is reduced by 90%, which is better than the competing solvent - based formula and meets GB 24409 - 2020.

[0129] Coupling agent pretreatment process: After nano - hexagonal boron nitride is modified by KH550, the peel strength between the coating and the rubber matrix is increased to ≥ 3.5 N / mm (≤ 1.2 N / mm for the traditional process), and the process adaptability is wider and the environmental tolerance is improved.

[0130] Other comparative data tests of the examples and comparative examples

[0131] Table 5 Accelerated wear life test (500,000 cycles)

[0132]

[0133] The wear rate of the coating of the present invention is only 33% of that of the traditional coating, and it remains intact after 500,000 cycles (SEM shows that the lubricating film is continuous); verified by the Martindale wear tester, the wear amount is reduced by 57% compared with the competing fluorocarbon coating, reaching the leading level in the industry.

[0134] Table 6 Comparison table of adhesion and temperature correlation

[0135]

[0136] Table 7 Comparison table of adhesion and temperature change resistance performance

[0137]

[0138] Through the synergistic crosslinking of two resins (acrylic - polyurethane), after 5 cycles of temperature change from -50°C to 150°C, the coating shows no cracking or peeling. After 500h of damp heat aging test, the adhesion retention rate is ≥95%, which is better than that of the coating in the comparative example (≤60%). Corrosion resistance verification (salt spray test, ASTM B117)

[0139] Table VIII Comparison Table of Corrosion Resistance Tests

[0140] Coating type Results of 720h salt spray test Corrosion expansion width (mm) Comparative example 1 Substrate rust area ≥ 50% 2.5-3.0 Comparative example 2 Slight pitting corrosion (area ≤ 10%) 0.5-1.0 Coating of Example 1 No substrate rust, coating intact ≤0.1 Coating of Example 2 No substrate rust, coating intact ≤0.1 Coating of Example 3 No substrate rust, coating intact ≤0.1 Coating of Example 4 No substrate rust, coating intact ≤0.1

[0141] The nano - hexagonal boron nitride / forged graphite milk composite layer blocks the penetration of corrosive media. After 720h of salt spray test, the electrochemical impedance (EIS) value remains ≥1×10 9 Ω·cm 2 , which is 3 orders of magnitude higher than that of the traditional coating. Through the cross - cut method test, the adhesion grade in the corrosion area remains 4B, verifying the long - term protection ability of the coating.

[0142] Test standards: GB 24409 - 2020, drying curve method, centrifugal stability test observation:[[]]END]]

[0143] Table IX Comparison Table of Environmental Friendliness and Process Stability

[0144]

[0145] The VOC emissions of the water - borne system are 80% lower than the national standard limit (≤50g / L). Through gas chromatography (GC - MS), it is verified that there is no harmful solvent residue. After the nano - hexagonal boron nitride is modified by KH550, the slurry shows no stratification under centrifugal stability (3000rpm, 30min), meeting the requirements of industrial production.

[0146] Table X Comparison Table of Wear Resistance Life Verification (500,000 cycles)

[0147]

[0148] The wear amount of the coating of the present invention is only 60mg after 500,000 cycles, and the friction coefficient remains stable (±5%), which is significantly better than that of Comparative Example 1 and Comparative Example 2 (120mg, and the friction coefficient rises to 0.25). SEM shows that the nano - hexagonal boron nitride - forged graphite milk composite lubricating layer still maintains a dense structure after long - term wear, verifying its self - repair property.

[0149] Table XI Environmental Adaptability Enhancement Test

[0150]

[0151] The wide-temperature performance is achieved through the co-crosslinking of two resins (acrylic-polyurethane). The recombination of hydrogen bond networks at high temperatures inhibits coating cracking. In a salt spray environment, the nano-hexagonal boron nitride-forged graphite milk layer blocks the penetration of Cl-, and the electrochemical impedance value remains ≥1×10 9 Ω·cm 2 , and the protective performance is better than that of the traditional epoxy resin system (≤1×10 6 Ω·cm 2 ).

[0152] The above examples and test data fully demonstrate that the coating material and spraying method provided by this patent have the advantages of high adhesion, high wear resistance, lubricity, and environmental protection, can effectively improve the wear resistance and service life of windshield wipers, and maintain good adhesion at the same time.

[0153] The above examples are only for illustrating the present invention and not for limiting it. Those skilled in the relevant technical fields can also make various transformations or modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also fall within the scope of the present invention, which should be defined by each claim.

Claims

1. A water-based coating material for a high-adhesion and wear-resistant automotive wiper rubber strip, characterized in that, It contains the following components in parts by mass: 40 - 65 parts of polyurethane prepolymer, the NCO content of the polyurethane prepolymer is 8% - 10%, and the molecular weight is 3000 - 5000; 20 - 40 parts of acrylic resin, the solid content of the acrylic resin is 40% - 45%, and the glass transition temperature Tg is 55 - 65 °C; 3 - 8 parts of nano - hexagonal boron nitride, the particle size of the nano - hexagonal boron nitride is 30 - 80 nm; 3 - 8 parts of forged graphite milk, the solid content of the forged graphite milk is 25% - 35%; 5 - 10 parts of aqueous isocyanate cross - linker, the NCO content of the aqueous isocyanate cross - linker is 8% - 12%; 0.5 - 1.5 parts of silane coupling agent; 40 - 70 parts of deionized water.

2. The waterborne coating for a high-adhesion and wear-resistant automotive wiper strip according to claim 1, wherein: The mass ratio of the polyurethane prepolymer to the acrylic resin is 1.5:1 - 2.5:

1.

3. The water-based coating for a high-adhesion and wear-resistant automotive wiper strip according to claim 1, characterized in that: The forged graphite milk is stably suspended by a non - ionic dispersant.

4. The waterborne coating material for a high-adhesion and wear-resistant automotive wiper rubber strip according to any one of claims 1 to 3, characterized in that: The preparation method is as follows: Step 1: Mix the polyurethane prepolymer and the acrylic resin at a shear rate of 1200 - 1800 rpm for 30 - 60 minutes to form a preliminary cross - link of the hydrogen bond network; Step 2: Ultrasonically disperse the nano - hexagonal boron nitride and the silane coupling agent at 50 - 70 °C for 0.5 - 1.5 hours to form a modified lubricating phase; add the forged graphite milk and continue stirring until evenly dispersed; Step 3: Further add the aqueous isocyanate cross - linker and mix evenly.

5. The water-based coating for a high-adhesion and wear-resistant automotive wiper rubber strip according to claim 4, characterized in that: The mass ratio of the surface - modified nano - hexagonal boron nitride in Step 2 to the added forged graphite milk is 1:0.8 - 1.

2.

6. The waterborne coating material for a high-adhesion and wear-resistant automotive wiper rubber strip according to claim 4, characterized in that: The acrylic resin in Step 1 is pre - heated to 40 °C to reduce the viscosity.

7. The waterborne coating material for a high-adhesion and wear-resistant automotive wiper rubber strip according to claim 4, characterized in that: In Step 1, the polyurethane prepolymer and the acrylic resin are mixed under nitrogen protection.

8. The waterborne coating material for a high-adhesion and wear-resistant automotive wiper rubber strip according to claim 4, wherein: The second step forms a modified lubricating phase, and the surface hydroxyl density after modification is ≥ 3.5 per nm 2 , so as to enhance the interfacial bonding force with the resin.

9. The water-based coating material for a high-adhesion and wear-resistant automotive wiper rubber strip according to claim 4, characterized in that: The aqueous isocyanate cross - linker uses HDI trimer as the cross - linker, and the addition amount is 8 ± 0.5% of the total amount of the resin obtained in Step 1, and triggers the acrylic - polyurethane synergistic cross - link at pH 7.2 ± 0.

3.

10. The spraying process of a high - adhesion and wear - resistant automotive wiper rubber strip aqueous coating material according to any one of claims 4 - 9, characterized in that: Step 1: Form a primer layer, pre - coat an epoxy primer on the surface of the wiper rubber strip to form a primer layer, the thickness of the primer layer is 5 μm, the adhesion grade is 4B, and pre - bake at 80 - 90 °C for 5 minutes to remove surface bubbles; Step 2: Main coating spraying, using high - pressure airless spraying, the pressure is 15 - 18 MPa, the nozzle diameter is 0.5 - 0.8 mm, the wet film thickness is 25 - 30 μm, and let it stand for 5 - 8 minutes after spraying for leveling; Step 3: Curing, cure by hot air circulation at 80 °C for 15 minutes, the heating rate ≤ 5 °C / min, and the dry film thickness is 15 - 18 μm; Step 4: Secondary curing, spray an ethanol solution containing 0.5% silane coupling agent on the surface of the coating in Step 3, and perform secondary curing at 120 - 130 °C for 5 minutes to form a hydrophobic protection layer; SEM shows that a continuous transition layer is formed at the interface between the coating and the substrate, the thickness of the continuous transition layer is about 1 μm, and the bonding strength ≥ 15 MPa ASTM D4541.

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