Water-based corrosion-resistant transparent primer composition as well as preparation method and application thereof

Abstract

The invention discloses a water-based corrosion-resistant transparent primer composition as well as a preparation method and application thereof. The transparent primer composition is prepared from the following components in parts by weight: 41.0 to 51.0 parts of a water-based acrylic resin dispersion, 6.0 to 10.0 parts of water-based polyester resin, 3.0 to 5.0 parts of water-based epoxy resin, 9.0 to 12.0 parts of amino resin, 3.2 to 5.2 parts of an auxiliary agent, 8.0 to 12.0 parts of a hydrophilic organic solvent and 12.0 to 18.0 parts of deionized water, wherein the auxiliary agent is prepared from the following components in parts by weight: 0.8 to 1.2 parts of phosphate ester polymer; 0.6 to 0.8 part of a corrosion inhibitor; and 1.5 to 2.5 parts of fumed silica. The VOC content of the water-based corrosion-resistant transparent primer composition under spraying viscosity meets related requirements, and meanwhile, the water-based corrosion-resistant transparent primer composition has good adhesive force, corrosion resistance, water resistance and the like, and can be well applied to coating of automobile aluminum alloy finish turning hubs.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and more specifically to a water-based corrosion-resistant transparent primer composition, a preparation method thereof and an application thereof. Background Art

[0002] The water-based corrosion-resistant primer composition uses acrylic resin, polyester resin, epoxy resin and amino resin as the main film-forming substances. The chemical reaction between the components will form an insoluble and infusible network structure, which gives it excellent adhesion, good corrosion resistance, water resistance and other properties. It can be widely used in the painting of automobile aluminum alloy precision wheel hubs.

[0003] With the continuous improvement of environmental protection requirements, various environmental protection-related regulations are becoming more and more stringent, especially the restrictions on the emissions of volatile organic compounds (VOCs), harmful solvents and the content of various heavy metals are becoming higher and higher. The development of green, environmentally friendly, low-VOC emission water-based corrosion-resistant primers has become a development trend in the coatings industry.

[0004] In the prior art, solvent-based corrosion-resistant transparent primers are often used for coating in the fields of automotive parts. Since the raw materials used in the preparation are high-viscosity, low-solid solvent-based resins, which contain a large amount of organic solvents, the existing solvent-based corrosion-resistant primers can only meet the requirements of GB 24409-2020 "Limits of Hazardous Substances in Vehicle Coatings" that the upper limit of VOC content under construction is 670g / L. Water-based corrosion-resistant transparent primers are prepared from water-based resins and amino resins, and the solvent of the water-based resin itself is water. Therefore, water-based corrosion-resistant transparent primers can achieve lower VOC emissions than solvent-based corrosion-resistant transparent primers, and their upper limit of VOC content is only 350g / L, which is much lower than solvent-based corrosion-resistant transparent primers.

[0005] In view of this, it is particularly necessary to provide a water-based corrosion-resistant transparent primer composition suitable for aluminum alloy precision car wheels and meeting the limit requirement of VOC≤350g / L specified in GB 24409-2020 "Limits of Hazardous Substances in Vehicle Coatings". Summary of the invention

[0006] Based on the above facts, the purpose of the present invention is to provide a water-based corrosion-resistant transparent primer composition and its preparation method and application. The VOC content of the water-based corrosion-resistant transparent primer composition at the spraying viscosity (after deducting water) meets the requirements of GB24409-2020 "Limits of Hazardous Substances in Vehicle Coatings", and has good adhesion, corrosion resistance, water resistance and other properties.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] In one aspect, the present invention provides a water-based corrosion-resistant transparent primer composition, which comprises the following components based on 100 parts by weight:

[0009]

[0010]

[0011] Wherein, the auxiliary agent comprises:

[0012] Phosphate polymer 0.8-1.2 parts;

[0013] Corrosion inhibitor 0.6-0.8 parts;

[0014] 1.5-2.5 parts of fumed silica.

[0015] Furthermore, the pH of the water-based corrosion-resistant transparent primer composition is 8.6-9.2.

[0016] Furthermore, the aqueous acrylic resin dispersion has one or more of the following characteristics:

[0017] (1) Non-volatile content is 41.0-46.0%;

[0018] (2) Viscosity <1000 mPa.s;

[0019] (3) pH is 7.5-9.5.

[0020] Furthermore, the water-based polyester resin has one or more of the following characteristics:

[0021] (1) Non-volatile content is 43.0-46.0%;

[0022] (2) Viscosity of 35-500 mPa.s;

[0023] (3) pH is 6.0-8.0.

[0024] Furthermore, the waterborne epoxy resin has one or more of the following characteristics:

[0025] (1) Non-volatile content is 37.0-44.0%;

[0026] (2) Viscosity: 300-3000 mPa.s;

[0027] (3) pH is 6.0-9.5.

[0028] Furthermore, the amino resin is a partially methylated amino resin, the non-volatile content of which is 86.0-90.0%, and the viscosity is 1400-10500 mPa.s.

[0029] Furthermore, the non-volatile content of the phosphate polymer is 50.0-66.0%.

[0030] Furthermore, the corrosion inhibitor is selected from organic corrosion inhibitors, which are in solid powder form and have a non-volatile content of 100%.

[0031] Furthermore, the fumed silica is a hydrophilic fumed silica with a specific surface area of ​​200 m 2 / g.

[0032] In another aspect, the present invention provides a method for preparing the water-based corrosion-resistant transparent primer composition as described above, comprising the following steps:

[0033] Dispersing the fumed silica in a portion of a hydrophilic organic solvent, and grinding to obtain a fumed silica slurry with a fineness of less than 5 μm;

[0034] Under stirring conditions, adding a water-based acrylic resin dispersion, a water-based polyester resin and a water-based epoxy resin into deionized water, mixing well, adding the remaining hydrophilic organic solvent, and then adding an amino resin to obtain a resin mixture;

[0035] The fumed silica slurry is mixed with a resin mixture, and then other auxiliary components are added, and the pH is adjusted to obtain the water-based corrosion-resistant transparent primer composition.

[0036] In another aspect, the present invention provides a water-based corrosion-resistant transparent primer, which is prepared from raw materials including the water-based corrosion-resistant transparent primer composition as described above.

[0037] In another aspect, the present invention provides a water-based corrosion-resistant transparent coating, which is prepared from the water-based corrosion-resistant transparent primer as described above.

[0038] In another aspect, the present invention provides the use of the aforementioned water-based corrosion-resistant transparent primer composition in the coating of automobile aluminum alloy finishing wheel hubs.

[0039] The beneficial effects of the present invention are as follows:

[0040] In the technical scheme of the present invention, by selecting, matching and controlling the amount of the raw materials of the transparent primer composition, the primer composition can be wet-to-wet sprayed with water-based or solvent-based liquid varnish, the corrosion-resistant primer spray solid content is greater than 25%, the spray viscosity range is 18-22 seconds / 20°C*4 cups, and the VOC content under the spray viscosity meets the requirements of GB 24409-2020 "Limits of Harmful Substances in Automotive Coatings" (GB 24409-2020 "Limits of Harmful Substances in Automotive Coatings" - Limit Value Requirements for VOC Content in Water-Based Coatings - Motorcycle (including electric motorcycles) and Bicycle (including electric bicycles) Coatings, Vehicle Parts - Coatings for Metal Parts - Primers - Limit Value (g / L) ≤ 350), and has good adhesion, corrosion resistance and water resistance. The water-based corrosion-resistant transparent primer composition provided by the present invention can be well applied to the coating of automotive aluminum alloy precision wheel hubs. DETAILED DESCRIPTION

[0041] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0042] In order to provide a transparent primer composition with good adhesion, corrosion resistance and water resistance suitable for aluminum alloy precision wheel hubs and meeting the limit requirement of VOC≤350g / L specified in GB 24409-2020 "Limits of Hazardous Substances in Vehicle Coatings", a specific embodiment of the present invention provides a water-based corrosion-resistant transparent primer composition, which comprises the following components based on 100 parts by weight:

[0043]

[0044] Wherein, the auxiliary agent comprises:

[0045] Phosphate polymer 0.8-1.2 parts;

[0046] Corrosion inhibitor 0.6-0.8 parts;

[0047] 1.5-2.5 parts of fumed silica.

[0048] In the technical solution of the present invention, water-based acrylic resin dispersion, water-based polyester resin, water-based epoxy resin and amino resin with specific addition amount and solid content are used as the main film-forming substances, and are matched with hydrophilic organic solvent and deionized water, so that the VOC of the prepared water-based corrosion-resistant transparent primer composition is ≤350g / L under the spraying viscosity.

[0049] The amino resin used will react with the water-based acrylic resin dispersion and the water-based polyester resin to achieve cross-linking and curing.

[0050] The phosphate polymer is added to improve the adhesion of the primer to the grooves of the aluminum alloy fine turning surface by increasing the plasticity of the substrate surface; the corrosion inhibitor is added to provide dense passivation protection for the aluminum alloy substrate surface to enhance the corrosion resistance of the primer; and a hydrophilic organic solvent is selected to ensure that the water-based corrosion-resistant transparent primer composition has good construction performance while ensuring that other properties remain unchanged.

[0051] Furthermore, the pH of the water-based corrosion-resistant transparent primer composition is 8.6-9.2.

[0052] In some examples, the aqueous acrylic resin dispersion has one or more of the following characteristics:

[0053] (1) The non-volatile content is 41.0-46.0%; exemplary non-volatile contents of aqueous acrylic resin dispersions include, but are not limited to, 41.0-43.0%, 44.0-46.0%, etc.;

[0054] (2) Viscosity < 1000 mPa.s; exemplary aqueous acrylic resin dispersions have viscosities including, but not limited to, 150-950 mPa.s, etc.;

[0055] (3) pH is 7.5-9.5; exemplary pH values ​​of aqueous acrylic resin dispersions include, but are not limited to, 7.5-8.5, 8.5-9.5, etc.

[0056] The use of the above-mentioned water-based acrylic resin dispersion not only meets other performance requirements of the primer composition, but also gives the paint film good water resistance, salt spray resistance, flexibility, corrosion resistance, adhesion and other properties.

[0057] Specifically, the aqueous acrylic resin dispersion includes but is not limited to PRO 1522CN (purchased from BASF), which has a non-volatile content of 44.0-46.0%, a viscosity of 150-950 mPa.s, and a pH of 8.5-9.5; it can also be AP 0081 (purchased from Suzhou Jiadian Company), which has a non-volatile content of 41.0-43.0%, a viscosity of <1000 mPa.s, and a pH of 7.5-8.5.

[0058] In some examples, the aqueous acrylic resin dispersion is a thermosetting acrylic resin dispersion, which contains no or only a very small amount of hydroxyl groups (much less than the content of hydroxyl groups in hydroxylated acrylic resins).

[0059] In this technical solution, water-based acrylic resin dispersion and water-based polyester resin are mixed to solve the problems of brittle paint film and poor adhesion caused by too high Tg value when only water-based acrylic resin dispersion is used; a small amount of epoxy resin is used to further improve the adhesion and corrosion resistance of the primer on aluminum alloy. If the amount of water-based acrylic resin dispersion and water-based polyester resin is not within the required range, it will affect the flexibility and hardness of the paint film.

[0060] Exemplarily, in the primer composition, the amount of the aqueous acrylic resin dispersion added includes but is not limited to 46-51 parts, 46-50 parts, 50-51 parts, 46.04 parts, 49.33 parts, 51 parts, etc.

[0061] In some examples, the waterborne polyester resin has one or more of the following characteristics:

[0062] (1) The non-volatile content is 43.0-46.0%; exemplary non-volatile contents of waterborne polyester resins include but are not limited to 43%, 44-46%, etc.;

[0063] (2) Viscosity of 35-500 mPa.s; exemplary viscosities of aqueous polyester resins include but are not limited to 35 mPa.s, 50-500 mPa.s, etc.;

[0064] (3) pH is 6.0-8.0; exemplary pH values ​​of aqueous polyester resins include, but are not limited to, 6.5-7.1.

[0065] The use of the waterborne polyester resin in this embodiment not only meets other performance requirements of the primer composition, but also gives the paint film good wetting and leveling properties, corrosion resistance and other properties.

[0066] Specifically, the water-based polyester resin is not limited to PU 1035W (purchased from BASF), with a non-volatile content of 43.0%, a viscosity of 35 mPa.s, and a pH of 6.0-8.0; or WATERSOL NP-6100 (Zhongshan) (purchased from DIC), with a non-volatile content of 44.0-46.0%, a viscosity of 50-500 mPa.s, and a pH of 6.5-7.1.

[0067] Exemplarily, in the primer composition, the amount of the water-based polyester resin added is 7-9 parts, 7.8-8.16 parts, 7.8 parts, 8.16 parts, etc.

[0068] In some examples, the waterborne epoxy resin has one or more of the following characteristics:

[0069] (1) The non-volatile content is 37.0-44.0%; illustratively, the non-volatile content of the waterborne epoxy resin includes but is not limited to 40-44%, 39-40%, etc.; preferably 40-44%;

[0070] (2) Viscosity of 300-3000 mPa.s; exemplary viscosity of waterborne epoxy resins includes but is not limited to 1000-1500 mPa.s, etc.;

[0071] (3) pH is 6.0-9.5; exemplary pH values ​​of waterborne epoxy resins include but are not limited to 6.0-8.0, 9.45, etc.; preferably 6.0-8.0.

[0072] The use of the waterborne epoxy resin in this embodiment not only meets other performance requirements of the primer composition, but also gives the paint film good storage stability and other properties.

[0073] Specifically, the water-based epoxy resin includes but is not limited to 6235 water-based epoxy resin (purchased from Shanghai Yitu Company), which has a non-volatile content of 40.0-44.0%, a viscosity of 300-3000mPa.s, and a pH of 6.0-8.0; it can also be EPICLON ZDW-497 (purchased from DIC Company), which has a non-volatile content of 39.65%, a viscosity of 1133mPa.s, and a pH of 9.45.

[0074] Adding too much water-based epoxy resin will cause the paint film to turn yellow and the weather resistance will be unqualified; adding too little water-based epoxy resin will affect the adhesion and corrosion resistance of the paint film.

[0075] Exemplarily, in the primer composition, the amount of waterborne epoxy resin added is 4-5 parts, 4-4.24 parts, 4 parts, 4.24 parts, etc.

[0076] In some examples, the amino resin is a partially methylated amino resin, and its non-volatile content is 86.0-90.0%, and its viscosity is 1400-10500 mPa.s. Exemplarily, the viscosity of the amino resin is 1400-10200 mPa.s, 5100-10200 mPa.s, 1400-6900 mPa.s, etc.; preferably 5100-10200 mPa.s.

[0077] Specifically, the amino resin includes but is not limited to CYMEL 370 (purchased from Allnex), which has a non-volatile content of 86.0-90.0% and a viscosity of 5100-10200 mPa.s; it can also be Resimene 741 (purchased from INEOS), which has a non-volatile content of 86.0-90.0% and a viscosity of 1400-6900 mPa.s.

[0078] Too much amino resin will cause excessive cross-linking of the paint film, making the paint film brittle and having unqualified adhesion; too little amino resin will cause the paint film to have unqualified water resistance and corrosion resistance.

[0079] Exemplarily, in the primer composition, the added amount of the amino resin is 10-12 parts, 10-11.3 parts, 10.5-11.3 parts, 10.5 parts, 11.3 parts, etc.

[0080] In this embodiment, further research has found that the amount ratio of the film-forming resins also affects the VOC content, water resistance and corrosion resistance of the final paint film. Preferably, when the mass ratio of the water-based acrylic resin dispersion, the water-based polyester resin, the water-based epoxy resin and the amino resin is (11.5-13): (1.8-2.1): 1: (2.4-3), the above effects are better. More preferably, it is (11.5-13): (1.95-2.04): 1: (2.62-2.83).

[0081] In some examples, the non-volatile content of the phosphate polymer is 50.0-66.0%. The non-volatile content of the phosphate polymer includes but is not limited to 50.0-52.0%, 59.0-66.0%, etc., preferably 50.0-52.0%, at which time the primer composition obtained has better acid and alkali corrosion resistance and salt spray resistance.

[0082] Specifically, the phosphate polymer includes but is not limited to -BOND AP 811 (purchased from Kashida Corporation), the non-volatile content of which is 50.0-52.0%; 2062 (available from Lubrizol), with a non-volatile content of 59.0-66.0%.

[0083] Exemplarily, in the primer composition, the added amount of the phosphate polymer is 0.8-1 part, 1-1.2 parts, 1 part, etc.

[0084] In some examples, the corrosion inhibitor is selected from organic corrosion inhibitors, which are in solid powder form and have a non-volatile content of 100%.

[0085] Specifically, the corrosion inhibitor is CANFAIR PPOA (purchased from Guangzhou Chenhui Chemical Company) with a non-volatile content of 100%; it can also be HALOX 350 (purchased from HALOX Company) with a non-volatile content of 100%. CANFAIR PPOA (purchased from Guangzhou Chenhui Chemical Company) is preferred, because the VOC content of the primer composition obtained is lower.

[0086] Exemplarily, in the primer composition, the corrosion inhibitor is added in an amount of 0.6-0.7 parts, 0.7-0.8 parts, 0.7 parts, etc.

[0087] In this embodiment, the fumed silica plays a thixotropic and anti-sagging role in the coating, which helps to paint the sharp corners of the aluminum alloy wheel hub, increase the thickness of the corrosion-resistant primer at the sharp corners, especially at the cutting edge of the finishing, and thus improve the edge anti-corrosion effect. In some examples, the fumed silica is a hydrophilic fumed silica; preferably, its specific surface area is 200m 2 / g.

[0088] Specifically, the fumed silica includes but is not limited to AEROSIL 200 (available from Evonik).

[0089] Exemplarily, in the primer composition, the added amount of fumed silica is 1.5-2 parts, 2-2.5 parts, 2 parts, etc.

[0090] In some examples, the additives also include one or more of a leveling agent, a defoaming agent, a pH adjuster, and a substrate wetting and dispersing agent. With appropriate amounts of additives such as a leveling agent, a pH adjuster, and a substrate wetting and dispersing agent, the problems of poor leveling and wetting of water-based coatings are solved.

[0091] Exemplarily, the leveling agent is an organosilicon leveling agent. Specifically, the organosilicon leveling agent includes but is not limited to one selected from TEGO 280 (purchased from TEGO) and BYK 345 (purchased from BYK) or a combination thereof. In the primer composition, the amount of the leveling agent added includes but is not limited to 0.2-0.3 parts, 0.2-0.25 parts, 0.25-0.3 parts, etc.

[0092] Exemplarily, the pH adjuster includes but is not limited to dimethylethanolamine (purchased from Yangzi Petrochemical-BASF Co., Ltd.). In the primer composition, the amount of the pH adjuster added includes but is not limited to 0-0.2 parts, 0-0.1 parts, 0.1-0.2 parts, etc.

[0093] For example, the substrate wetting powder includes, but is not limited to, SURFYNOL 104PG-50 (available from Air Chemistry). In the primer composition, the amount of the substrate wetting powder added includes, but is not limited to, 0.1-0.2 parts, 0.1-0.15 parts, 0.15-0.2 parts, etc.

[0094] Exemplarily, the weight of the other components in the additive except the phosphate polymer, the corrosion inhibitor and the fumed silica is 0.3-0.7 parts in total.

[0095] Exemplarily, the total weight of the leveling agent, pH adjuster and substrate wetting and dispersing agent in the additive is 0.1-0.5 parts.

[0096] In some examples, the hydrophilic organic solvent is selected from one or a combination of ether solvents and ester solvents. Ether solvents have good hydrophilicity, which helps the stability and dispersion of amino resins, water-based acrylic resin dispersions, and water-based polyester resins in water-based systems; among them, high-boiling-point ether solvents can also prevent the problem of prickly heat during the primer baking process.

[0097] Specifically, the ether solvent includes but is not limited to one or a combination thereof selected from ethylene glycol butyl ether, propylene glycol methyl ether and tripropylene glycol methyl ether. In some preferred embodiments, the ether solvent includes 4.0-5.5 parts of ethylene glycol butyl ether, 4.0-5.5 parts of propylene glycol methyl ether, and 0-4.0 parts of tripropylene glycol methyl ether.

[0098] The addition amount of tripropylene glycol methyl ether includes but is not limited to 0 part, 0.1-4.0 parts. A small amount of high-boiling-point ether solvent tripropylene glycol methyl ether as a hydrophilic organic solvent is not only miscible with water, but also can prevent the problem of prickly heat during the baking process of the corrosion-resistant transparent primer.

[0099] According to another specific embodiment of the present invention, a method for preparing a water-based corrosion-resistant transparent primer composition is provided, comprising the following steps:

[0100] Dispersing the fumed silica in a portion of a hydrophilic organic solvent, and grinding to obtain a fumed silica slurry with a fineness of less than 5 μm;

[0101] Under stirring conditions, adding a water-based acrylic resin dispersion, a water-based polyester resin and a water-based epoxy resin into deionized water, mixing well, adding the remaining hydrophilic organic solvent, and then adding an amino resin to obtain a resin mixture;

[0102] The fumed silica slurry is mixed with a resin mixture, and then other auxiliary components are added, and the pH is adjusted to obtain the water-based corrosion-resistant transparent primer composition.

[0103] In some examples, the stirring rate is 300-400 r / min.

[0104] During the preparation of the primer composition, film-forming resin cannot be added during the dispersion and grinding of the fumed silica, otherwise the stability of the primer composition product will be affected. When the primer composition is used as a primer, flocculation will occur, resulting in poor wetting and leveling properties when sprayed.

[0105] In the preparation process of the primer composition, if the amino resin is added first and then the remaining hydrophilic organic solvent is added, the primer composition obtained is easy to agglomerate and difficult to mix evenly, and thus cannot be sprayed for construction.

[0106] In some examples, the preparation of the fumed silica slurry with a fineness of less than 5 μm comprises the following steps:

[0107] (1) adding ethylene glycol butyl ether and part of propylene glycol methyl ether into a container, stirring at 100-200 r / min, adding a formula amount of fumed silica under stirring, stirring for 5-10 min until the mixture is uniformly mixed, and setting aside;

[0108] (2) Add the fumed silica slurry stirred evenly in step (1) into a grinding device, rinse the container of the mixed fumed silica with the remaining propylene glycol methyl ether, add the rinsed propylene glycol methyl ether into the grinding device, grind and disperse the fumed silica slurry to a fineness of less than 5 μm, and obtain a fumed silica slurry with a fineness of less than 5 μm.

[0109] Compared with the use of propylene glycol methyl ether alone, the primer composition obtained by using different aqueous organic solvents in different stages in the preparation of the primer composition has a better appearance.

[0110] According to another specific embodiment of the present invention, a water-based corrosion-resistant transparent primer is provided. The water-based corrosion-resistant transparent primer is prepared from raw materials including the water-based corrosion-resistant transparent primer composition as described above.

[0111] According to another specific embodiment of the present invention, there is provided a water-based corrosion-resistant transparent coating, which is prepared from the water-based corrosion-resistant transparent primer as described above.

[0112] According to another specific embodiment of the present invention, there is provided a use of the above-mentioned water-based corrosion-resistant transparent primer composition in the coating of automobile aluminum alloy finishing wheel hubs.

[0113] In some examples, the application includes the following steps:

[0114] Applying the water-based corrosion-resistant transparent primer composition on the finished aluminum alloy wheel hub of an automobile, flash drying, and dehydrating;

[0115] A solvent-based clear coat is applied and cured to give a composite coating.

[0116] Furthermore, the flash drying condition is 80°C*10min.

[0117] Furthermore, the curing temperature is 140-150° C., and the curing time is 15-35 min, preferably 20 min.

[0118] Furthermore, the application method is air spraying and / or electrostatic hanging cup spraying.

[0119] Further, the thickness of the applied water-based corrosion-resistant transparent primer composition is 15-20 μm.

[0120] Further, the solvent-based varnish is applied to a thickness of 15-20 μm.

[0121] Furthermore, the thickness of the obtained composite coating is 50-60 μm.

[0122] The technical solution of the present invention is described below in conjunction with some specific embodiments:

[0123] The relevant raw material models and manufacturers used in the examples are as follows:

[0124] Water-based acrylic resin dispersion: PRO 1522CN, purchased from BASF; AP 0081, purchased from Suzhou Jiadian Company;

[0125] Waterborne polyester resin: PU 1035W, purchased from BASF; WATERSOL NP-6100 (Zhongshan), purchased from DIC;

[0126] Waterborne epoxy resin: 6235 waterborne epoxy resin, purchased from Shanghai Yitu Company; EPICLON ZDW-497, purchased from DIC Company;

[0127] Amino resin: CYMEL 370, purchased from Allnex; Resimene 741, purchased from INEOS;

[0128] Phosphate Ester Polymers: -BOND AP 811, purchased from Cashstar Corporation; 2062, purchased from Lubrizol;

[0129] Corrosion inhibitors: CANFAIR PPOA, purchased from Guangzhou Chenhui Chemical Company; HALOX 350, purchased from HALOX Company;

[0130] Leveling agent: TEGO 280, purchased from TEGO; BYK 345, purchased from BYK;

[0131] Substrate wetting and dispersing agent: SURFYNOL 104PG-50, purchased from Air Chemical;

[0132] pH adjuster: dimethylethanolamine, purchased from Yangzi Petrochemical-BASF Co., Ltd.;

[0133] Fumed silica: AEROSIL 200, purchased from Evonik.

[0134] Example 1

[0135] Water-based corrosion-resistant transparent primer composition 1

[0136] A water-based corrosion-resistant transparent primer composition 1 was prepared according to the formula shown in Table 1 below:

[0137] Table 1 Weight parts of raw materials in Example 1

[0138]

[0139] The preparation of the water-based corrosion-resistant transparent primer composition 1 comprises the following steps:

[0140] (1) Add about 4.0 parts of ethylene glycol butyl ether and 3.0 parts of propylene glycol methyl ether into a container, stir at 100-200 r / min, add 2.0 parts of fumed silica under stirring, stir for 5-10 minutes until the mixture is uniformly mixed, and set aside;

[0141] (2) adding the stirred fumed silica slurry to a grinding device, washing the container of the mixed fumed silica with the remaining 2.0 parts of propylene glycol methyl ether, adding the washed propylene glycol methyl ether to the grinding device, grinding and dispersing the fumed silica slurry to a fineness of less than 5 μm, and setting aside;

[0142] (3) adding 16.0 parts of deionized water, stirring at 300-400 r / min, first adding 46.04 parts of acrylic resin dispersion, 8.16 parts of water-based polyester resin, and 4.0 parts of water-based epoxy resin, respectively, and continuing stirring for 5-10 minutes;

[0143] (4) adding the remaining 1 part of ethylene glycol butyl ether and 1 part of tripropylene glycol methyl ether, stirring for 5-10 minutes, and then adding 10.5 parts of amino resin and continuing to stir for 5-10 minutes;

[0144] (5) adding 11.0 parts of the fumed silica slurry prepared in the second step;

[0145] (6) adding 1.00 part of phosphate polymer, 0.7 part of corrosion inhibitor, 0.26 part of leveling agent and 0.18 part of substrate wetting and dispersing agent, and stirring for 20-300 minutes;

[0146] (7) The pH value is adjusted to the range of 8.6-9.2 using 0.16 parts of a pH adjuster to obtain the water-based corrosion-resistant transparent primer composition 1.

[0147] Comparative Example 1

[0148] Water-based corrosion-resistant transparent primer composition C1

[0149] Example 1 was repeated except that a commercially available aqueous acrylic resin dispersion was used. A 2470 (non-volatile content of 44-47%, viscosity of 1500-3000 mPa.s, hydroxyl content of 3.9%) was used to replace the aqueous acrylic resin dispersion in Example 1 in equal solid amounts, and the amounts of other materials remained unchanged.

[0150] Compared with the aqueous acrylic resin dispersion of Example 1, A 2470 has a relatively high viscosity and contains a certain amount of hydroxyl reactive groups.

[0151] Comparative Example 2

[0152] Water-based corrosion-resistant transparent primer composition C2

[0153] Example 1 was repeated, except that the commercially available water-based polyester resin ACW 1011 (non-volatile content of 29.5-30.5%, bubble viscosity (Gardner) of Z4-Z6) was used to replace the water-based polyester resin in Example 1 in equal solid amounts, and the amounts of other materials remained unchanged.

[0154] Compared with the water-based polyester resin of Example 1, the water-based polyester resin ACW 1011 has a higher viscosity and a lower non-volatile content.

[0155] Comparative Example 3

[0156] Water-based corrosion-resistant transparent primer composition C3

[0157] Example 1 was repeated, except that the solid amount of commercially available water-based epoxy resin MODEPICS 304C was used to replace the water-based epoxy resin in Example 1, and the amounts of other materials remained unchanged.

[0158] Specifically, the non-volatile content of the waterborne epoxy resin MODEPICS 304C is 36.0%, which is relatively low.

[0159] Comparative Example 4

[0160] Water-based corrosion-resistant transparent primer composition C4

[0161] Example 1 was repeated, except that the amount of aqueous acrylic resin dispersion, aqueous polyester resin and deionized water was used. The specific weight percentages of the raw materials are shown in Table 2.

[0162] Table 2 Comparative Example 4 Raw Materials by Weight

[0163]

[0164] Comparative Example 5

[0165] Water-based corrosion-resistant transparent primer composition C5

[0166] Example 1 was repeated, except that the amount of aqueous acrylic resin dispersion, aqueous polyester resin and deionized water was used. The specific weight percentages of the raw materials are shown in Table 3.

[0167] Table 3 Comparative Example 5 Raw Materials by Weight

[0168]

[0169] Comparative Example 6

[0170] Water-based corrosion-resistant transparent primer composition C6

[0171] Example 1 was repeated, except that the amount of waterborne epoxy resin and deionized water was used. The specific weight percentages of the raw materials are shown in Table 4.

[0172] Table 4 Comparative Example 6 Raw Materials by Weight

[0173]

[0174] Comparative Example 7

[0175] Water-based corrosion-resistant transparent primer composition C7

[0176] Example 1 was repeated, except that the amount of waterborne epoxy resin and deionized water was used. The specific weight percentages of the raw materials are shown in Table 5.

[0177] Table 5 Comparative Example 7 Raw Materials by Weight

[0178]

[0179] Comparative Example 8

[0180] Water-based corrosion-resistant transparent primer composition C8

[0181] Example 1 was repeated, except that the amount of amino resin and deionized water was different. The specific weight percentages of the raw materials are shown in Table 6.

[0182] Table 6 Comparative Example 8 Raw Materials by Weight

[0183]

[0184] Comparative Example 9

[0185] Water-based corrosion-resistant transparent primer composition C9

[0186] Example 1 was repeated, except that the amount of amino resin and deionized water was changed. The specific weight percentages of the raw materials are shown in Table 7.

[0187] Table 7 Comparative Example 9 Raw Materials by Weight

[0188]

[0189] Test Example 1:

[0190] Performance test of water-based corrosion-resistant transparent primer composition

[0191] a) Construction

[0192] Base material: Pre-treated aluminum alloy wheel hub

[0193] Coating composition: aluminum alloy finishing wheel hub + water-based corrosion-resistant transparent primer (80℃*10min flash drying, dehydration) + solvent-based varnish (curing, curing temperature is 140-150℃, time is 20min), that is, a water-based corrosion-resistant transparent primer composite coating with a thickness of 50-60μm sprayed on the aluminum alloy finishing wheel hub is obtained.

[0194] Painting process:

[0195] Corrosion-resistant transparent primer: Spray with an automatic air spray gun, air pressure 0.25 MPa, discharge volume 100cc, primer spray viscosity 18.0-22.0 seconds / 20℃*apply 4 cups; dry film thickness 15-20μm.

[0196] Solvent-based varnish: LACTEC robot, spraying under the conditions of hanging cup diameter 65mm, voltage 60Kv, hanging cup speed 20000rpm, and discharge volume 350cc, the varnish spraying viscosity is 30.0-32.0s / 20℃*4 cups; dry film thickness is 35-40μm.

[0197] b) Preparation of coating performance test samples, i.e. cutting off the single spokes of the aluminum alloy wheel hub that has been painted for construction test for coating performance test.

[0198] The performance testing method is shown in Table 8:

[0199] Table 8 Performance test methods

[0200]

[0201] The above method was used to test the performance of the water-based corrosion-resistant transparent primer of Example 1 and Comparative Examples 1-9. The results are shown in Tables 9 and 10.

[0202] Table 9 Performance of the primer of Example 1 and Comparative Examples 1-4

[0203]

[0204]

[0205] Table 10 Performance of primers of comparative examples 5-9

[0206]

[0207]

[0208] As can be seen from Table 9, the water-based corrosion-resistant transparent primer composition prepared in Example 1 was sprayed under standard construction conditions, and the paint film had no abnormal appearance. The VOC content was 310 g / L, which met the requirement of "≤350 g / L" specified in GB 24409, and the corrosion resistance and water resistance were qualified.

[0209] Comparative Example 1: Use commercially available aqueous acrylic resin dispersion A 2470 replaces the aqueous acrylic resin dispersion in Example 1 in an equal amount of solids. Aqueous acrylic resin dispersion A 2470 has a high viscosity and contains a certain amount of hydroxyl reactive groups, with a hydroxyl content of 3.9%. The use of this water-based acrylic resin dispersion will result in unqualified corrosion resistance (CASS) and adhesion, which is due to the increase in the number of reactive groups in the water-based acrylic resin dispersion in Comparative Example 1, which is unbalanced with the ratio of the number of reactive groups in the amino resin compared to Example 1, resulting in insufficient crosslinking of the paint film.

[0210] Comparative Example 2 uses commercially available water-based polyester resin ACW 1011 and other solids to replace the water-based polyester resin in Example 1, and the amounts of other materials remain unchanged. ACW 1011 has a low non-volatile content and high viscosity. The use of this water-based polyester resin will result in poor wetting and leveling of the water-based corrosion-resistant transparent primer on the aluminum alloy substrate, and the coating film does not cover the groove of the aluminum alloy wheel hub fine turning, and the corrosion resistance is unqualified.

[0211] Comparative Example 3 uses commercially available water-based epoxy resin MODEPICS 304C to replace the water-based epoxy resin in Example 1 in terms of solid amount, and the amounts of other materials remain unchanged. The non-volatile content of MODEPICS 304C is 36.0%, while the non-volatile content of the water-based epoxy resin preferred in the present invention is 37.0-44.0%, which is relatively low. The use of such water-based epoxy resin will lead to instability of the water-based corrosion-resistant transparent primer resin system, poor storage stability, and stratification.

[0212] In comparative example 4, the amount of amino resin remains unchanged, the amount of aqueous acrylic resin dispersion used is 53.04 parts, which exceeds the upper limit of the amount range of 51.0 parts, and the amount of the aqueous polyester resin used is 5.16 parts, which is lower than the lower limit of the amount range of 6.0 parts. Excessive use of aqueous acrylic resin dispersion and too low use of aqueous polyester resin will lead to poor flexibility of the paint film and unqualified adhesion of the composite coating.

[0213] The amount of amino resin in Comparative Example 5 remains unchanged, the amount of waterborne acrylic resin dispersion is 40.04 parts, which is lower than the lower limit of the amount range of 41.0 parts, and the amount of waterborne polyester resin is 12.16 parts, which exceeds the upper limit of the amount range of 10.0 parts. Too low an amount of waterborne acrylic resin dispersion and too much waterborne polyester resin will cause the paint film to become soft, and the hardness of the composite coating is unqualified.

[0214] In Comparative Example 6, the amount of waterborne acrylic resin dispersion, waterborne polyester resin and amino resin remains unchanged, and the amount of waterborne epoxy resin is 2.0 parts, which is lower than the lower limit of the amount ratio of 3.0 parts, and is not within the scope of the present invention, so this example is only Comparative Example 6. Too low an amount of waterborne epoxy resin will result in unqualified corrosion resistance of the paint.

[0215] The amount of waterborne acrylic resin dispersion, waterborne polyester resin and amino resin in Comparative Example 7 remains unchanged, and the amount of waterborne epoxy resin is 6.0 parts, which is higher than the upper limit of the amount ratio of 5.0 parts, and is not within the scope of the present invention, so this example is only Comparative Example 7. Too high an amount of waterborne epoxy resin will cause the paint film to turn yellow and the weather resistance to be unqualified.

[0216] In Comparative Example 8, the amount of waterborne acrylic resin dispersion, waterborne polyester resin and waterborne epoxy resin remains unchanged, and the amount of amino resin is 13.5 parts, which is higher than the upper limit of 12.0 parts. Too high an amount of amino resin will lead to excessive cross-linking of the paint film, making the paint film brittle and having unqualified adhesion.

[0217] In Comparative Example 9, the amount of waterborne acrylic resin dispersion, waterborne polyester resin and waterborne epoxy resin remains unchanged, and the amount of amino resin is 8.5 parts, which is lower than the lower limit of 9.0 parts. Too low an amount of amino resin will result in insufficient crosslinking density of the paint film, and the water resistance and corrosion resistance of the paint film are unqualified.

[0218] Example 2

[0219] Water-based corrosion-resistant transparent primer composition 2

[0220] Example 1 was repeated, except for the type and amount of the aqueous acrylic resin dispersion and the amount of deionized water. The weight percentages of the raw materials in Example 2 are shown in Table 11. The aqueous acrylic resin dispersion was AP 0081 and had a non-volatile content of 42%.

[0221] Table 11 Raw materials weight parts of Example 2

[0222]

[0223] The preparation of the above-mentioned water-based corrosion-resistant transparent primer composition 2 comprises the following steps:

[0224] (1) Add about 4.0 parts of ethylene glycol butyl ether and 3.0 parts of propylene glycol methyl ether into a container, stir at 100-200 r / min, add 2.0 parts of fumed silica under stirring, stir for 5-10 minutes until the mixture is uniformly mixed, and set aside;

[0225] (2) adding the stirred fumed silica slurry to a grinding device, washing the container of the mixed fumed silica with the remaining 2.0 parts of propylene glycol methyl ether, adding the washed propylene glycol methyl ether to the grinding device, grinding and dispersing the fumed silica slurry to a fineness of less than 5 μm, and setting aside;

[0226] (3) adding 12.71 parts of deionized water, stirring at 300-400 r / min, first adding 49.33 parts of acrylic resin dispersion, 8.16 parts of water-based polyester resin, and 4.0 parts of water-based epoxy resin, respectively, and continuing stirring for 5-10 minutes;

[0227] (4) adding the remaining 1 part of ethylene glycol butyl ether and 1 part of tripropylene glycol methyl ether, stirring for 5-10 minutes, and then adding 10.5 parts of amino resin and continuing to stir for 5-10 minutes;

[0228] (5) adding 11.0 parts of the fumed silica slurry prepared in the second step;

[0229] (6) adding 1.0 part of phosphate polymer, 0.7 part of corrosion inhibitor, 0.26 part of leveling agent and 0.18 part of substrate wetting and dispersing agent, and stirring for 20-300 minutes;

[0230] (7) The pH value was adjusted to the range of 8.6-9.2 using 0.16 parts of a pH adjuster to obtain the water-based corrosion-resistant transparent primer composition 2.

[0231] Example 3

[0232] Water-based corrosion-resistant transparent primer composition 3

[0233] Example 1 was repeated, except for the type and amount of waterborne polyester and the amount of deionized water. The weight percentages of the raw materials in Example 3 are shown in Table 12. The waterborne polyester resin was WATERSOL NP-6100 (Zhongshan) with a non-volatile content of 45%.

[0234] Table 12 Raw materials weight parts of Example 3

[0235]

[0236] The preparation of the above-mentioned water-based corrosion-resistant transparent primer composition 3 comprises the following steps:

[0237] (1) Add about 4.0 parts of ethylene glycol butyl ether and 3.0 parts of propylene glycol methyl ether into a container, stir at 100-200 r / min, add 2.0 parts of fumed silica under stirring, stir for 5-10 minutes until the mixture is uniformly mixed, and set aside;

[0238] (2) adding the stirred fumed silica slurry to a grinding device, washing the container of the mixed fumed silica with the remaining 2.0 parts of propylene glycol methyl ether, adding the washed propylene glycol methyl ether to the grinding device, grinding and dispersing the fumed silica slurry to a fineness of less than 5 μm, and setting aside;

[0239] (3) adding 16.36 parts of deionized water, stirring at 300-400 r / min, first adding 46.04 parts of acrylic resin dispersion, 7.80 parts of water-based polyester resin, and 4.0 parts of water-based epoxy resin, respectively, and continuing stirring for 5-10 minutes;

[0240] (4) adding the remaining 1 part of ethylene glycol butyl ether and 1 part of tripropylene glycol methyl ether, stirring for 5-10 minutes, and then adding 10.5 parts of amino resin and continuing to stir for 5-10 minutes;

[0241] (5) adding 11.0 parts of the fumed silica slurry prepared in the second step;

[0242] (6) adding 1.00 part of phosphate polymer, 0.7 part of corrosion inhibitor, 0.26 part of leveling agent and 0.18 part of substrate wetting and dispersing agent, and stirring for 20-300 minutes;

[0243] (7) The pH value was adjusted to the range of 8.6-9.2 using 0.16 parts of a pH adjuster to obtain the water-based corrosion-resistant transparent primer composition 3.

[0244] Example 4

[0245] Water-based corrosion-resistant transparent primer composition 4

[0246] A water-based corrosion-resistant transparent primer composition 4 was prepared according to the formulation shown in Table 13 below.

[0247] Table 13 Weight parts of raw materials in Example 4

[0248]

[0249] The preparation of the water-based corrosion-resistant transparent primer composition 4 comprises the following steps:

[0250] (1) Add about 4.0 parts of ethylene glycol butyl ether and 3.0 parts of propylene glycol methyl ether into a container, stir at 100 to 200 r / min, add 2.0 parts of fumed silica under stirring, stir for 5 to 10 minutes until the mixture is uniformly mixed, and set aside;

[0251] (2) adding the stirred fumed silica slurry to a grinding device, washing the container of the mixed fumed silica with the remaining 1.5 parts of propylene glycol methyl ether, adding the washed propylene glycol methyl ether to the grinding device, grinding and dispersing the fumed silica slurry to a fineness of less than 5 μm, and setting aside;

[0252] (3) adding 12.00 parts of deionized water, stirring at 300-400 r / min, first adding 51.00 parts of acrylic resin dispersion, 8.16 parts of water-based polyester resin, and 4.0 parts of water-based epoxy resin, respectively, and continuing stirring for 5-10 minutes;

[0253] (4) adding the remaining 0.5 parts of ethylene glycol butyl ether and 0.24 parts of tripropylene glycol methyl ether, stirring for 5-10 minutes, and then adding 11.3 parts of amino resin and continuing to stir for 5-10 minutes;

[0254] (5) adding 10.5 parts of the fumed silica slurry prepared in the second step;

[0255] (6) adding 1.00 part of phosphate polymer, 0.70 part of corrosion inhibitor, 0.26 part of leveling agent and 0.18 part of substrate wetting and dispersing agent, and stirring for 20-300 minutes;

[0256] (7) The pH value is adjusted to the range of 8.6-9.2 with 0.16 parts of pH adjuster to obtain the water-based corrosion-resistant transparent primer composition 4.

[0257] Example 5

[0258] Water-based corrosion-resistant transparent primer composition 5

[0259] Example 1 was repeated, except that the waterborne epoxy resin was EPICLON ZDW-497, the amount of which was 4.24 parts, and the amount of deionized water was changed to 15.76 parts.

[0260] Example 6

[0261] Water-based corrosion-resistant transparent primer composition 6

[0262] Example 1 was repeated, except that the amino resin was Resimene 741.

[0263] Example 7

[0264] Water-based corrosion-resistant transparent primer composition 7

[0265] Example 1 was repeated, except that HALOX 350 was used as the corrosion inhibitor.

[0266] Example 8

[0267] Water-based corrosion-resistant transparent primer composition 8

[0268] Example 1 was repeated, except that the phosphate polymer was 2062.

[0269] Example 9

[0270] Water-based corrosion-resistant transparent primer composition 9

[0271] Example 1 was repeated, except that the weight portion of the aqueous acrylic resin dispersion was 41.0 parts, the weight portion of the aqueous polyester resin was 10.0 parts, the weight portion of the aqueous epoxy resin was 5.0 parts, the weight portion of the amino resin was 10.09 parts, the weight portion of deionized water was 18.0 parts, and the weight portion of tripropylene glycol methyl ether was 1.61 parts.

[0272] Example 10

[0273] Water-based corrosion-resistant transparent primer composition 10

[0274] Example 1 was repeated, with the only difference being the types of waterborne acrylic resin dispersion, waterborne polyester resin, waterborne epoxy resin and amino resin and the amounts of some components. The weight parts of the raw materials in Example 10 are shown in Table 14.

[0275] Table 14 Raw materials weight parts of Example 10

[0276]

[0277]

[0278] According to the method of the above-mentioned Test Example 1, the VOC content and main coating properties of the water-based corrosion-resistant transparent primer compositions prepared in Examples 2-10 were tested. The test results are shown in Table 15, and the test results are similar to those of Example 1, indicating that the components and proportions of the water-based corrosion-resistant transparent primer specified in the scheme of the present invention can achieve good performance, and the types of water-based acrylic resin dispersions, water-based polyester resins, water-based epoxy resins and amino resins used in the present invention have excellent effects.

[0279] Table 15 VOC content and main parameters of water-based primers of Examples 2-10

[0280]

[0281]

[0282] Comparative Example 10

[0283] Water-based corrosion-resistant transparent primer composition C10

[0284] The only difference between Comparative Example 10 and Example 1 is that in the preparation process of the water-based corrosion-resistant clear paint composition C10, the water-based acrylic resin dispersion is ground and dispersed together with the fumed silica and a portion of the hydrophilic solvent. As a result, the prepared water-based corrosion-resistant clear primer composition flocculates after being left at room temperature for 1 day, and the flocculated clear primer has poor spray wetting and leveling properties after being diluted with water and stirred evenly.

[0285] Comparative Example 11

[0286] Water-based corrosion-resistant transparent primer composition C11

[0287] Compared with Example 1, the difference of Comparative Example 11 is that in step (4), the amino resin is added first, and then the remaining hydrophilic organic solvent is added. As a result, the obtained transparent primer composition agglomerates, is unevenly mixed, and cannot be sprayed.

[0288] Comparative Example 12

[0289] Water-based corrosion-resistant transparent primer composition C12

[0290] The only difference between Comparative Example 12 and Example 1 is that propylene glycol methyl ether is used to replace ethylene glycol butyl ether and tripropylene glycol methyl ether. Results The water-based corrosion-resistant transparent primer coating obtained under the same viscosity and plate making process had prickly heat at the center hole of the wheel hub, and the appearance was unqualified.

[0291] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A water-based corrosion-resistant transparent primer composition, It is characterized in that The total weight is 100 parts, comprising the following components: Wherein, the auxiliary agent comprises: Phosphate polymer 0.8-1.2 parts; Corrosion inhibitor 0.6-0.8 parts; 1.5-2.5 parts of fumed silica.

2. The water-based corrosion-resistant transparent primer composition according to claim 1, It is characterized in that The pH value of the water-based corrosion-resistant transparent primer composition is 8.6-9.

2.

3. The water-based corrosion-resistant transparent primer composition according to claim 1, It is characterized in that The aqueous acrylic resin dispersion has one or more of the following characteristics: (1) Non-volatile content is 41.0-46.0%; (2) Viscosity <1000 mPa.s; (3) pH is 7.5-9.

5.

4. The water-based corrosion-resistant transparent primer composition according to claim 1, It is characterized in that The waterborne polyester resin has one or more of the following characteristics: (1) Non-volatile content is 43.0-46.0%; (2) Viscosity of 35-500 mPa.s; (3) pH is 6.0-8.

0.

5. The water-based corrosion-resistant transparent primer composition according to claim 1, It is characterized in that The waterborne epoxy resin has one or more of the following characteristics: (1) Non-volatile content is 37.0-44.0%; (2) Viscosity: 300-3000 mPa.s; (3) pH is 6.0-9.

5.

6. The water-based corrosion-resistant transparent primer composition according to claim 1, It is characterized in that The amino resin is a partially methylated amino resin, the non-volatile content of which is 86.0-90.0% and the viscosity is 1400-10500 mPa.s; and / or The non-volatile content of the phosphate polymer is 50.0-66.0%; and / or The corrosion inhibitor is selected from organic corrosion inhibitors, which are solid powders with a non-volatile content of 100%; and / or The fumed silica is hydrophilic fumed silica with a specific surface area of ​​200 m 2 / g.

7. A method for preparing the water-based corrosion-resistant transparent primer composition according to any one of claims 1 to 6, It is characterized in that The steps include: Dispersing the fumed silica in a portion of a hydrophilic organic solvent, and grinding to obtain a fumed silica slurry with a fineness of less than 5 μm; Under stirring conditions, adding a water-based acrylic resin dispersion, a water-based polyester resin and a water-based epoxy resin into deionized water, mixing well, adding the remaining hydrophilic organic solvent, and then adding an amino resin to obtain a resin mixture; The fumed silica slurry is mixed with a resin mixture, and then other auxiliary components are added, and the pH is adjusted to obtain the water-based corrosion-resistant transparent primer composition.

8. A water-based corrosion-resistant transparent primer, It is characterized in that The water-based corrosion-resistant transparent primer is prepared from raw materials including the water-based corrosion-resistant transparent primer composition according to any one of claims 1 to 6.

9. A water-based corrosion-resistant transparent coating, It is characterized in that The invention is prepared from the water-based corrosion-resistant transparent primer as claimed in claim 8.

10. Use of the water-based corrosion-resistant transparent primer composition according to any one of claims 1 to 6 in the coating of automobile aluminum alloy finishing wheel hubs.

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