High-wear-resistance and high-light-resistance automotive trim surface treating agent and preparation method thereof

Abstract

The invention discloses a high-wear-resistance and high-light-resistance automotive interior surface treating agent and a preparation method thereof, and relates to the technical field of fine chemical engineering and automotive interior materials. The treating agent is composed of 60-80 parts of aliphatic waterborne polyurethane resin dispersion, 5-15 parts of a wear-resistant and scratch-resistant auxiliary agent, 1-3 parts of a water-based cross-linking agent, an auxiliary agent and the like, wherein the wear-resistant and scratch-resistant auxiliary agent is a compound of light-stable weather-resistant surface hydrophilic modified nano silicon dioxide sol and polytetrafluoroethylene wax emulsion. The silane coupling agent mixed solution, the light stabilizer and the hydrophilic modifier are used for carrying out surface chemical modification on nano silicon dioxide, and the nano silicon dioxide is compounded with the polytetrafluoroethylene wax emulsion, so that the problems that nano particles are easy to agglomerate, the light stabilizer is easy to migrate and the wear resistance and the weather resistance are insufficient in the prior art are solved. The prepared surface treating agent has excellent wear resistance and scratch resistance, long-acting light resistance and weather resistance and good dispersion stability, and is suitable for surface treatment of automotive upholstery.

Description

Technical Field

[0001] This invention relates to the fields of fine chemicals and automotive interior materials technology, specifically to a high wear-resistant and light-resistant automotive interior surface treatment agent and its preparation method. Background Technology

[0002] With the rapid development of the automotive industry and the increasing demands of consumers for driving experience, the surface quality of automotive interior components such as dashboards, door panels, and seat leather has received widespread attention. To meet increasingly stringent environmental regulations, waterborne coatings with low volatile organic compound (VOC) emissions are gradually replacing traditional solvent-based coatings, becoming the mainstream choice for automotive interior surface treatment. Among these, aliphatic waterborne polyurethane resin dispersions are widely used as the base resin in interior surface treatment agents due to their good flexibility, adhesion, and solvent resistance. However, compared to solvent-based systems, simple waterborne polyurethane coatings often fall short in terms of surface mechanical strength, abrasion resistance, and light and weather resistance, making it difficult to directly meet the long-term use requirements of automotive interiors under harsh environments such as high temperature, high humidity, and strong ultraviolet radiation.

[0003] To improve the mechanical properties of coatings, existing technologies typically modify them by adding wear-resistant and scratch-resistant additives. Commonly used wear-resistant additives include inorganic particles such as nano-silica, while scratch-resistant additives often use polyethylene wax or polytetrafluoroethylene wax emulsions. However, directly adding inorganic nanoparticles to aqueous systems has significant drawbacks: due to their extremely high surface energy, nanoparticles are prone to aggregation, leading to uneven dispersion in the aqueous resin. This not only fails to effectively exert their nano-reinforcing effect but may also cause the coating to whiten and increase haze, severely affecting the interior appearance. Furthermore, the interfacial compatibility between inorganic particles and the organic resin matrix is ​​poor, resulting in weak bonding. Under external friction, the particles easily detach from the coating surface, further reducing the coating's wear resistance. While wax emulsions alone can provide a smooth feel, they cannot provide sufficient hardness support, making it difficult to simultaneously meet the dual requirements of high wear resistance and high scratch resistance.

[0004] Regarding light and weather resistance, automotive interiors are constantly exposed to sunlight streaming through car windows, making them highly susceptible to aging, discoloration, and cracking. Existing technologies often employ physical blending to add UV absorbers or hindered amine light stabilizers. However, these small-molecule light stabilizers do not chemically bond with the resin matrix and are prone to migration, surfacing, or evaporation during long-term use, leading to blooming and light-stabilizing failure, thus failing to provide long-lasting protection. Therefore, it is crucial to develop an automotive interior surface treatment agent that overcomes the shortcomings of inorganic nano-abrasion-resistant particles in aqueous systems, such as poor dispersion stability and weak interfacial bonding, as well as the tendency for light stabilizers to migrate and fail, while simultaneously possessing high abrasion resistance, high scratch resistance, and excellent long-lasting light and weather resistance. Summary of the Invention

[0005] The purpose of this invention is to provide a high wear-resistant and light-resistant automotive interior surface treatment agent and its preparation method, so as to solve the technical problems of easy agglomeration of inorganic nanoparticles, difficulty in achieving both wear resistance and tactile feel, and easy migration of light stabilizers leading to weather resistance failure in existing automotive interior surface treatment agents.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A high-wear-resistant and light-resistant automotive interior surface treatment agent comprises the following components in parts by weight: 60 to 80 parts of aliphatic waterborne polyurethane resin dispersion, 5 to 15 parts of wear-resistant and scratch-resistant additive, 1 to 3 parts of waterborne crosslinking agent, 0.2 to 1 part of wetting and leveling agent, 0.1 to 0.5 parts of defoamer, 0.5 to 2 parts of light-resistant and weather-resistant agent, and 10 to 20 parts of deionized water. The wear-resistant and scratch-resistant additive is a compound of light-stabilized, weather-resistant, surface-modified hydrophilic nano-silica sol and polytetrafluoroethylene wax emulsion.

[0008] In the above-mentioned high wear-resistant and light-resistant automotive interior surface treatment agent, the aliphatic waterborne polyurethane resin dispersion is specifically selected from one or more of polycarbonate-type anionic aliphatic waterborne polyurethane dispersions or polyester-type anionic aliphatic waterborne polyurethane dispersions with a solid content of 35% to 45% by weight.

[0009] The aqueous crosslinking agent is specifically selected from one or more of hydrophilic modified hexamethylene diisocyanate trimer and hydrophilic modified isophorone diisocyanate trimer.

[0010] The wetting and leveling agent is specifically selected from one or more of polyether-modified polydimethylsiloxane and fluorocarbon-modified polyacrylate.

[0011] The defoamer is specifically selected from one or more of mineral oil defoamers and polyether siloxane copolymer emulsion defoamers.

[0012] The light and weather resistant agent is specifically selected from one or more of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole.

[0013] The light-stabilized, weather-resistant, and hydrophilic-modified nano-silica sol in the wear-resistant and scratch-resistant additive is prepared by reacting nano-silica sol with a silane coupling agent mixture, a light stabilizer, and a hydrophilic modifier. The silane coupling agent mixture is composed of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane.

[0014] The light stabilizer is 1-(α-(benzotriazol-1-yl)benzyl)-2-naphthol;

[0015] The hydrophilic modifier is polyethylene glycol monomethyl ether methacrylate.

[0016] In the aforementioned wear-resistant and scratch-resistant additive, the solid content mass ratio of the light-stabilized, weather-resistant, surface-modified hydrophilic nano-silica sol to the polytetrafluoroethylene wax emulsion is 3:1 to 5:1. The light-stabilized, weather-resistant, surface-modified hydrophilic nano-silica sol has a particle size of 10 nanometers to 50 nanometers. The polytetrafluoroethylene wax emulsion has an average particle size of 0.2 micrometers to 0.5 micrometers.

[0017] This invention also provides a method for preparing the above-mentioned high abrasion resistance and light resistance automotive interior surface treatment agent, comprising the following steps:

[0018] The first step is to prepare the wear-resistant and scratch-resistant additive. This step specifically includes three sub-steps:

[0019] S1: Preparation of light-stable, weather-resistant, and hydrophilically modified nano-silica sol. The nano-silica sol was heated, and a silane coupling agent mixture was added dropwise to the reaction system. After maintaining the temperature for the reaction, a light stabilizer was added, and the reaction was continued at the same temperature. Subsequently, the temperature was lowered, and a hydrophilic modifier, polyethylene glycol monomethyl ether methacrylate, was added. The pH value was adjusted to obtain the target product. In this process, the silane coupling agent mixture was composed of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane in a mass ratio of 1:1:0.5. The solid content of the nano-silica sol was 30% by weight. 5 to 15 parts by weight of the silane coupling agent mixture were added dropwise to every 100 parts by weight of the nano-silica sol. The specific process parameters are as follows: the reaction system is heated to 60 to 80 degrees Celsius; after adding the silane coupling agent mixture, the reaction is kept at this temperature for 2 to 4 hours; after adding the light stabilizer, the reaction is kept at this temperature for 1 to 2 hours; after cooling to 40 to 50 degrees Celsius, the hydrophilic modifier is added, the pH value is adjusted to 8.0 to 9.0, and the reaction is stirred for 1 hour.

[0020] S2: Preparation of polytetrafluoroethylene (PTFE) wax emulsion. PTFE wax powder is mixed with an emulsifier and deionized water, and then homogenized and emulsified using a high-pressure homogenizer to obtain a PTFE wax emulsion. In this process, the emulsifier is a compound of sodium dodecyl sulfate and nonylphenol polyoxyethylene ether at a mass ratio of 2:1. The mass ratio of PTFE wax powder, emulsifier, and deionized water is 20:3:77. The homogenization and emulsification process parameters are: pressure 40 MPa to 60 MPa, temperature 80°C to 90°C, homogenization emulsification three times, and each homogenization time 5 minutes.

[0021] S3: Compounding. The light-stabilized, weather-resistant, surface-modified hydrophilic nano-silica sol prepared in step S1 and the polytetrafluoroethylene wax emulsion prepared in step S2 are added to a mixing vessel and stirred. The pH value is adjusted, and the mixture is filtered to obtain the wear-resistant and scratch-resistant additive. The specific process parameters are: stirring speed of 200 to 400 rpm, temperature of 25 to 40 degrees Celsius, stirring time of 30 to 60 minutes, and pH value adjusted to 7.0 to 8.0.

[0022] The second step is to prepare the surface treatment agent. Aliphatic waterborne polyurethane resin dispersion and deionized water are added to a dispersion tank and stirred. Wetting and leveling agent, defoamer, and light and weather resistant agent are added sequentially and dispersed at high speed. Then, the stirring speed is reduced, and the wear-resistant and scratch-resistant additive prepared in the first step is added and stirring continues. Finally, an aqueous crosslinking agent is added, stirred evenly, and filtered to obtain the high wear-resistant and light-resistant automotive interior surface treatment agent. Specific process parameters are as follows: after adding the aliphatic waterborne polyurethane resin dispersion and deionized water, the stirring speed is 300 rpm to 600 rpm, and the stirring time is 5 to 10 minutes; after adding the wetting and leveling agent, defoamer, and light and weather resistant agent, the high-speed dispersion speed is 800 rpm to 1200 rpm, and the dispersion time is 15 to 20 minutes; after adding the wear-resistant and scratch-resistant additive, the stirring speed is 400 rpm to 600 rpm, and the stirring time is 20 to 30 minutes.

[0023] This invention achieves a synergistic effect of excellent physical and mechanical properties and weather resistance through multi-component microstructure design and macroscopic compounding. First, a silane coupling agent mixture is used to chemically modify the surface of nano-silica. This not only provides abundant reaction sites for subsequent grafting but also enhances the interfacial chemical bonding between the inorganic particles and the aliphatic waterborne polyurethane resin dispersion matrix through amino and epoxy groups, preventing particle detachment during friction. Second, a specific light stabilizer, 1-(α-(benzotriazol-1-yl)benzyl)-2-naphthol, is firmly anchored to the surface of the nanoparticles through chemical bonding. The uniform dispersion characteristics of the nanoparticles in the coating construct a "lattice-like" long-lasting UV shielding network, fundamentally solving the problems of easy migration, blooming, and volatilization failure of traditional physically blended small-molecule light stabilizers. Furthermore, polyethylene glycol monomethyl ether is introduced... As a hydrophilic modifier, acrylate forms a steric hindrance layer on the surface of nanoparticles due to its long-chain structure, which greatly improves the dispersion stability of modified nano-silica in aqueous systems, effectively preventing agglomeration and sedimentation and ensuring the transparency of the coating. Finally, this modified nano-silica with high hardness and light stability is compounded with polytetrafluoroethylene wax emulsion with low surface energy. During the film formation process, the polytetrafluoroethylene wax tends to migrate to the surface to reduce the coefficient of friction, providing excellent smooth feel and reducing external impact. Meanwhile, the modified nano-silica dispersed in the coating interior and subsurface provides strong rigid support. This externally smooth and internally hard structural design significantly improves the wear resistance, scratch resistance and long-term light and weather resistance of automotive interior surfaces.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. This invention significantly improves the overall physical and mechanical properties of waterborne polyurethane coatings by using a compound of light-stable, weather-resistant, hydrophilically modified nano-silica sol and polytetrafluoroethylene wax emulsion as an abrasion-resistant and scratch-resistant additive. The high hardness of nano-silica provides structural support and abrasion resistance, while the low surface energy of polytetrafluoroethylene wax provides a low coefficient of friction and a smooth feel. This micro-compound strategy combining softness and hardness produces a synergistic effect of external smoothness and internal hardness, effectively solving the problem that a single additive cannot simultaneously achieve high abrasion resistance, high scratch resistance, and excellent tactile feel. This makes the treated automotive interior surfaces less prone to scratches or damage when subjected to external friction.

[0026] 2. This invention significantly improves the dispersion stability and interfacial bonding of inorganic nanoparticles in aqueous systems by using a specific combination of silane coupling agents containing amino and epoxy groups and a hydrophilic modifier to modify the surface of nano-silica. The steric hindrance provided by the hydrophilic long chains greatly inhibits the aggregation and sedimentation of nanoparticles, ensuring the storage stability of the treatment agent and the high transparency of the coating film, avoiding whitening or haze. At the same time, the introduction of active functional groups enhances the chemical bonding between inorganic particles and the organic resin matrix, preventing particles from falling off during friction and further extending the wear life of the coating.

[0027] 3. This invention achieves long-lasting light and weather resistance in automotive interior surface treatment agents. Through a chemical reaction, a specific light stabilizer with UV absorption function is grafted onto the surface of nano-silica, firmly anchoring the light-stabilizing groups onto the nanoparticle carrier. The uniform dispersion of the nanoparticles in the coating constructs a highly efficient lattice-type UV shielding network. This structural modification method completely solves the problems of migration, blooming, or volatilization that easily occur with traditional physically blended small-molecule light stabilizers during long-term use. It can effectively block UV damage to the matrix resin for a long time, significantly delaying the aging, discoloration, and cracking of automotive interior parts. Attached Figure Description

[0028] Figure 1 The infrared spectrum of the wear-resistant and scratch-resistant additive prepared in Example 1 of this invention. Detailed Implementation

[0029] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] Preparation of a high abrasion-resistant and light-resistant automotive interior surface treatment agent:

[0032] 1. Raw material components by weight:

[0033] 70 parts of aliphatic waterborne polyurethane resin dispersion (selected as polycarbonate-type anionic aliphatic waterborne polyurethane dispersion with a solid content of 40% by weight), 10 parts of abrasion-resistant and scratch-resistant additive, 2 parts of waterborne crosslinking agent (selected as hydrophilic modified hexamethylene diisocyanate trimer), 0.6 parts of wetting and leveling agent (selected as polyether modified polydimethylsiloxane), 0.3 parts of defoamer (selected as polyether siloxane copolymer emulsion defoamer), 1.2 parts of light and weather resistant agent (selected as bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate), and 15 parts of deionized water;

[0034] The wear-resistant and scratch-resistant additive is a mixture of light-stabilized, weather-resistant, surface-modified hydrophilic nano-silica sol and polytetrafluoroethylene wax emulsion at a solid content mass ratio of 4:1. The light-stabilized, weather-resistant, surface-modified hydrophilic nano-silica sol has a nano-silica particle size of 30 nanometers and a solid content of 25% by weight. The polytetrafluoroethylene wax emulsion has an average particle size of 0.35 micrometers.

[0035] The CAS number for the light stabilizer 1-(α-(benzotriazol-1-yl)benzyl)-2-naphthol is 132377-90-3, and its structure is as follows: .

[0036] 2. Preparation method:

[0037] The first step is to prepare the wear-resistant and scratch-resistant additive:

[0038] S1: Place 25% by weight of nano-silica sol in a reaction vessel, heat the reaction system to 70 degrees Celsius, and add 10 parts by weight of silane coupling agent mixture to the reaction system at a ratio of 10 parts by weight per 100 parts by weight of nano-silica sol. The silane coupling agent mixture (composed of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane in a mass ratio of 1:1) is added dropwise to the reaction system. The mixture was prepared by adding the ingredients in a 1:0.5 ratio and maintaining the temperature at 70°C for 3 hours. Then, the light stabilizer 1-(α-(benzotriazol-1-yl)benzyl)-2-naphthol was added to the reaction system, and the reaction was continued at 70°C for 1.5 hours. The reaction system was then cooled to 45°C, and the hydrophilic modifier polyethylene glycol monomethyl ether methacrylate was added. The pH of the system was adjusted to 8.5 using an alkaline regulator, and the reaction was stirred for 1 hour to obtain a light-stable, weather-resistant, surface-modified hydrophilic nano-silica sol.

[0039] S2: Weigh polytetrafluoroethylene wax powder, composite emulsifier, and deionized water according to a mass ratio of 20:3:77. The composite emulsifier is a compound of sodium dodecyl sulfate and nonylphenol polyoxyethylene ether in a mass ratio of 2:1. After mixing the three, add them to a high-pressure homogenizer and homogenize and emulsify them under the conditions of 50 MPa pressure and 85 degrees Celsius. The homogenization and emulsification are performed 3 times, and the homogenization time is 5 minutes each time to obtain polytetrafluoroethylene wax emulsion.

[0040] S3: The light-stabilized, weather-resistant, surface-modified hydrophilic nano-silica sol prepared in step S1 and the polytetrafluoroethylene wax emulsion prepared in step S2 are added to a mixing vessel at a solid content mass ratio of 4:1. The mixture is stirred and mixed for 45 minutes at a stirring speed of 300 rpm and a temperature of 30 degrees Celsius. The pH of the system is adjusted to 7.5 with a regulator. After filtration through a 200-mesh filter cloth, the wear-resistant and scratch-resistant additive is obtained. Its infrared spectrum is shown below. Figure 1 As shown;

[0041] The second step is to prepare the surface treatment agent:

[0042] 70 parts of aliphatic waterborne polyurethane resin dispersion and 15 parts of deionized water were added to a dispersion tank and stirred at 450 rpm for 7 minutes to obtain a homogeneous mixture. 0.6 parts of wetting and leveling agent, 0.3 parts of defoamer, and 1.2 parts of light-resistant and weather-resistant agent were added sequentially to the mixture, and the stirring speed was increased to 1000 rpm for high-speed dispersion for 18 minutes. Then, the stirring speed was reduced to 500 rpm, and 10 parts of the wear-resistant and scratch-resistant additive prepared in the first step were added, and stirring continued for 25 minutes. Finally, 2 parts of waterborne crosslinking agent were added to the system, and stirring was maintained at 500 rpm until the system was homogeneous. After filtration through a 300-mesh filter cloth, the high wear-resistant and light-resistant automotive interior surface treatment agent was obtained.

[0043] Example 2

[0044] The preparation of a high wear-resistant and light-resistant automotive interior surface treatment agent is carried out according to the steps of Example 1, except that 70 parts of polycarbonate-type anionic aliphatic waterborne polyurethane dispersion are replaced with 60 parts of polyester-type anionic aliphatic waterborne polyurethane dispersion, and 0.6 parts of polyether-modified polydimethylsiloxane are replaced with 1 part of fluorocarbon-modified polyacrylate, while the rest remains the same as in Example 1.

[0045] Example 3

[0046] The preparation of a high wear-resistant and light-resistant automotive interior surface treatment agent is carried out according to the steps of Example 1, except that the 30-nanometer nano-silica particles are replaced with 10-nanometer nano-silica particles, and the 0.35-micron polytetrafluoroethylene wax emulsion is replaced with 0.2-micron polytetrafluoroethylene wax emulsion, while the rest remains the same as in Example 1.

[0047] Example 4

[0048] The preparation of a high wear-resistant and light-resistant automotive interior surface treatment agent follows the steps of Example 1, except that the solid content mass ratio of the light-stable, weather-resistant, surface-modified hydrophilic nano-silica sol to polytetrafluoroethylene wax emulsion is changed from 4:1 to 5:1, the 30-nanometer nano-silica particles are changed to 50-nanometer nano-silica particles, and the 0.35-micron polytetrafluoroethylene wax emulsion is changed to 0.5-micron polytetrafluoroethylene wax emulsion. The rest remains the same as in Example 1.

[0049] Comparative Example 1

[0050] The preparation of a high wear-resistant and light-resistant automotive interior surface treatment agent is carried out according to the steps of Example 1, except that the light-stable, weather-resistant, surface-modified hydrophilic nano-silica sol is replaced with nano-silica sol without any surface modification, and the rest is the same as in Example 1.

[0051] Comparative Example 2

[0052] The preparation of a high wear-resistant and light-resistant automotive interior surface treatment agent is carried out according to the steps of Example 1, except that the wear-resistant and scratch-resistant additive, which is a compound of light-stable, weather-resistant, surface-modified hydrophilic nano-silica sol and polytetrafluoroethylene wax emulsion at a solid content mass ratio of 4:1, is replaced with a single polytetrafluoroethylene wax emulsion as the wear-resistant and scratch-resistant additive, and the rest is the same as in Example 1.

[0053] Comparative Example 3

[0054] The preparation of a high wear-resistant and light-resistant automotive interior surface treatment agent is carried out according to the steps of Example 1, except that the nano-silica sol with photo-stable and weather-resistant surface hydrophilic modification by chemically bonding grafting light stabilizer is replaced with unmodified nano-silica sol with only physical blending of an equal amount of light stabilizer, and the rest is the same as in Example 1.

[0055] Comparative Example 4

[0056] The preparation of a high wear-resistant and light-resistant automotive interior surface treatment agent is carried out according to the steps of Example 1, except that the light stabilizer in the wear-resistant and scratch-resistant additive is replaced with bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and the rest is the same as in Example 1.

[0057] Comparative Example 5

[0058] The preparation of a high wear-resistant and light-resistant automotive interior surface treatment agent is carried out according to the steps of Example 1, except that the light stabilizer in the wear-resistant and scratch-resistant additive is replaced with 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, and the rest is the same as in Example 1.

[0059] Comparative Example 6

[0060] The preparation of a high wear-resistant and light-resistant automotive interior surface treatment agent is carried out according to the steps of Example 1, except that no light stabilizer is added in the preparation of the wear-resistant and scratch-resistant additive, and the rest is the same as in Example 1.

[0061] Performance testing:

[0062] Common automotive interior substrates (PP / PE composite sheets, automotive artificial leather, ABS engineering plastic sheets) were selected as test substrates. The substrates were wiped with anhydrous ethanol to remove oil, lightly sanded with 200-grit sandpaper, and then air-dried for later use. The high abrasion-resistant and light-resistant automotive interior surface treatment agent prepared in this invention was applied to the surface of the treated substrates by air spraying, and the dry film thickness was controlled to be 20~30μm. After coating, the substrates were first leveled at room temperature for 10~15min, and then baked and cured at 60±2℃ for 30min. After cooling to room temperature, the substrates were left to stand for 24h to obtain standard test samples.

[0063] 1. Xenon lamp aging test: Performed according to GB / T1865-2009, using a xenon lamp aging test chamber, selecting an automotive interior aging test filter, and setting the irradiance to 0.55W / (m²). 2. The test was conducted at a temperature of 65±2℃ and a relative humidity of 50±5% in the chamber. The spraying cycle was 120min / 18min (light / spray), and the aging test time was 2000h. After the test, the color difference ΔE of the sample coating was measured using a colorimeter according to GB / T11186.2-1989. The data are shown in Table 1.

[0064] 2. Ultraviolet Aging Test: Performed according to GB / T14522-2008, using a fluorescent ultraviolet aging test chamber, with the ultraviolet wavelength set to 313nm and the irradiance to 0.71W / (m²). 2. The test conditions were 4 hours of ultraviolet light irradiation (temperature 60±2℃) + 4 hours of condensation (temperature 50±2℃) as one cycle, with a cumulative aging of 1000 hours; the evaluation criteria after the test were the same as those for the xenon lamp aging test, and the data are shown in Table 1.

[0065] 3. Coating adhesion test: Performed according to GB / T9286-1998. Use a cross-cutting tool to make 10×10 squares (square size 1mm×1mm) on the coating surface, with the depth of the cross-cutting reaching the substrate surface. Use a soft brush to gently brush the cross-cutting area to remove paint debris. Apply 3M 600 tape tightly to the cross-cutting area, press the tape with your finger to ensure there are no air bubbles, and then quickly peel off the tape at a 60° angle. Observe the degree of coating peeling in the squares. Evaluate the adhesion level from 0 to 5, with level 0 being the best (no coating peeling) and level 5 being the worst (coating completely peeling off). The data are shown in Table 1.

[0066] 4. Abrasion resistance test: The test was conducted according to GB / T1768-2006 using a Taber abrasion tester with a CS-10 grinding wheel, a load mass of 500g, and a grinding wheel rotation frequency of 1000 revolutions. After the test, the mass of the sample before and after the test was measured using an electronic balance with an accuracy of 0.1mg. The mass loss rate was calculated. The lower the mass loss rate, the better the abrasion resistance of the coating. The data are shown in Table 1.

[0067] Table 1

[0068] Xenon lamp aging test (ΔE) Ultraviolet aging test (ΔE) Adhesion test level Quality loss rate (%) Example 1 0.6 0.8 Level 0 1.2 Example 2 0.7 0.9 Level 0 1.3 Example 3 0.5 0.7 Level 0 1.1 Example 4 0.6 0.8 Level 0 1.2 Comparative Example 1 2.1 2.5 Level 1 4.5 Comparative Example 2 1.8 2.2 Level 1 5.2 Comparative Example 3 3.5 4.2 Level 2 4.6 Comparative Example 4 2.6 3.1 Level 0 1.4 Comparative Example 5 2.8 3.3 Level 0 1.4 Comparative Example 6 6.5 7.8 Level 0 1.3

[0069] This invention constructs a uniformly dispersed, lattice-like, long-lasting UV shielding network by chemically bonding a specific light stabilizer to the surface of nano-silica modified with a silane coupling agent and a hydrophilic modifier. Simultaneously, the synergistic compounding of polytetrafluoroethylene (PTFE) wax emulsion and modified nanoparticles forms a microstructure that is smooth on the outside and hard on the inside. This results in a coating exhibiting extremely low color difference and excellent gloss retention under xenon lamp and UV aging conditions. Furthermore, the strong interfacial bonding between the nanoparticles and the resin matrix maintains the highest adhesion. In contrast, unmodified nanoparticles cause uneven protection and haze due to agglomeration; single PTFE wax lacks UV absorption capacity; physically blended light stabilizers quickly fail due to migration and blooming; replacing them with conventional light stabilizers has some effect but is not as effective as the chemically bonded system; and systems completely lacking light-stabilizing protection suffer severe photo-oxidative degradation, leading to yellowing, chalking, and cracking. Moreover, the coatings in the comparative example, which lacked effective interfacial bonding, also showed a decreasing adhesion trend.

[0070] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-wear-resistant and light-resistant automotive interior surface treatment agent, characterized in that, Its raw materials include the following components in parts by weight: 60 to 80 parts of aliphatic waterborne polyurethane resin dispersion, 5 to 15 parts of abrasion-resistant and scratch-resistant additive, 1 to 3 parts of waterborne crosslinking agent, 0.2 to 1 part of wetting and leveling agent, 0.1 to 0.5 parts of defoamer, 0.5 to 2 parts of light-resistant and weather-resistant agent, and 10 to 20 parts of deionized water; The wear-resistant and scratch-resistant additive is a compound of light-stabilized, weather-resistant, surface-modified hydrophilic nano-silica sol and polytetrafluoroethylene wax emulsion.

2. The high wear-resistant and light-resistant automotive interior surface treatment agent according to claim 1, characterized in that, The aliphatic waterborne polyurethane resin dispersion is selected from one or more of polycarbonate-type anionic aliphatic waterborne polyurethane dispersions or polyester-type anionic aliphatic waterborne polyurethane dispersions with a solid content of 35% to 45% by weight. The aqueous crosslinking agent is selected from hydrophilically modified hexamethylene diisocyanate trimer; The wetting and leveling agent is selected from one or more of polyether-modified polydimethylsiloxane and fluorocarbon-modified polyacrylate. The defoamer is selected from one or more of mineral oil defoamers and polyether siloxane copolymer emulsion defoamers; The light and weather resistant agent is selected from one or more of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole.

3. The high wear-resistant and light-resistant automotive interior surface treatment agent according to claim 1, characterized in that, The light-stabilized, weather-resistant, surface-modified hydrophilic nano-silica sol is prepared by reacting and modifying nano-silica sol with a mixture of silane coupling agent, light stabilizer, and hydrophilic modifier. The silane coupling agent mixture is composed of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane. The light stabilizer is 1-(α-(benzotriazol-1-yl)benzyl)-2-naphthol; The hydrophilic modifier is polyethylene glycol monomethyl ether methacrylate.

4. A high abrasion-resistant and light-resistant automotive interior surface treatment agent according to claim 1 or 3, characterized in that, In the wear-resistant and scratch-resistant additive, the solid content mass ratio of the light-stabilized, weather-resistant, surface-modified hydrophilic nano-silica sol to the polytetrafluoroethylene wax emulsion is 3:1 to 5:

1. The nano-silica particles in the light-stable, weather-resistant, surface-modified hydrophilic nano-silica sol have a particle size of 10 nanometers to 50 nanometers. The average particle size of the polytetrafluoroethylene wax emulsion is 0.2 micrometers to 0.5 micrometers.

5. A method for preparing a high abrasion-resistant and light-resistant automotive interior surface treatment agent as described in any one of claims 1 to 4, characterized in that, Includes the following steps: The first step is to prepare the wear-resistant and scratch-resistant additive: S1: Heat the nano silica sol, add a mixture of silane coupling agents dropwise to the reaction system, add a light stabilizer after the reaction, then cool down and add the hydrophilic modifier polyethylene glycol monomethyl ether methacrylate, adjust the pH value, and obtain a light-stable, weather-resistant, surface-modified hydrophilic nano silica sol. S2: Mix polytetrafluoroethylene wax powder with emulsifier and deionized water, and then homogenize and emulsify the mixture using a high-pressure homogenizer to obtain a polytetrafluoroethylene wax emulsion. S3: Add the light-stable, weather-resistant, surface-modified hydrophilic nano-silica sol prepared in step S1 and the polytetrafluoroethylene wax emulsion prepared in step S2 into a mixing vessel and stir to mix. Adjust the pH value and filter to obtain the wear-resistant and scratch-resistant additive. The second step is to prepare the surface treatment agent: Aliphatic waterborne polyurethane resin dispersion and deionized water were added to a dispersion tank and stirred. Wetting and leveling agent, defoamer and light and weather resistant agent were added in sequence and dispersed at high speed. Then the stirring speed was reduced and the wear-resistant and scratch-resistant additive prepared in the first step was added and stirring continued. Finally, waterborne crosslinking agent was added, stirred evenly and filtered to obtain the high wear-resistant and light-resistant automotive interior surface treatment agent.

6. The method for preparing the high wear-resistant and light-resistant automotive interior surface treatment agent according to claim 5, characterized in that, In step S1, the silane coupling agent mixture is composed of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane in a mass ratio of 1:1:0.5; the solid content of the nano-silica sol is 20%-30% by weight; 5 to 15 parts by weight of the silane coupling agent mixture are added dropwise to every 100 parts by weight of nano-silica sol.

7. The method for preparing the high wear-resistant and light-resistant automotive interior surface treatment agent according to claim 5, characterized in that, In step S1, the reaction system is heated to 60°C to 80°C; after adding the silane coupling agent mixture, the reaction is kept at this temperature for 2 to 4 hours; after adding the light stabilizer, the reaction is kept at this temperature for another 1 to 2 hours; after cooling to 40°C to 50°C, a hydrophilic modifier is added, the pH value is adjusted to 8.0 to 9.0, and the reaction is stirred for 1 hour.

8. The method for preparing the high wear-resistant and light-resistant automotive interior surface treatment agent according to claim 5, characterized in that, In step S2, the emulsifier is a compound of sodium dodecyl sulfate and nonylphenol polyoxyethylene ether in a mass ratio of 2:1; the mass ratio of polytetrafluoroethylene wax powder, emulsifier and deionized water is 20:3:77; the homogenization emulsification pressure is 40 MPa to 60 MPa, the temperature is 80 degrees Celsius to 90 degrees Celsius, the homogenization emulsification is performed 3 times, and the homogenization time is 5 minutes each time.

9. The method for preparing the high wear-resistant and light-resistant automotive interior surface treatment agent according to claim 5, characterized in that, In step S3, the stirring speed is 200 to 400 rpm, the temperature is 25 to 40 degrees Celsius, the stirring time is 30 to 60 minutes, and the pH value is adjusted to 7.0 to 8.

0.

10. The method for preparing the high wear-resistant and light-resistant automotive interior surface treatment agent according to claim 5, characterized in that, In the second step, after adding the aliphatic waterborne polyurethane resin dispersion and deionized water, the stirring speed is 300 to 600 rpm, and the stirring time is 5 to 10 minutes; after adding the wetting and leveling agent, defoamer and light and weather resistant agent, the high-speed dispersion speed is 800 to 1200 rpm, and the dispersion time is 15 to 20 minutes. After adding the wear-resistant and scratch-resistant additive, the stirring speed is 400 to 600 rpm, and the stirring time is 20 to 30 minutes.

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