High-film-thickness automobile original factory water-based B1 base coat as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of materials, and particularly relates to a high-film-thickness automobile original factory water-based B1 base coat as well as a preparation method and application of the high-film-thickness automobile original factory water-based B1 base coat. The high-film-thickness automobile original factory water-based B1 base coat is prepared from the following components in parts by mass: 15 to 25 parts of acrylic acid modified high molecular weight polyurethane, 5 to 10 parts of water-based acrylic resin emulsion, 5 to 15 parts of modified high molecular weight polyester, 4 to 8 parts of amino resin, 1 to 1.5 parts of surfactant, 1 to 1.5 parts of thickening agent, 0.2 to 0.5 part of defoaming agent, 1 to 1.5 parts of dispersing agent, 0.5 to 1.5 parts of wetting leveling agent, 15 to 25 parts of pigment and 1 to 1.5 parts of talcum powder. 0.5-1 part of fumed silica, 0.5-2 parts of a pH regulator, 1-5 parts of ethylene glycol butyl ether, 2-8 parts of a cosolvent and 15-25 parts of water. According to the invention, the appearance qualification rate is improved, and the product has excellent performances of good flatness, good stone impact resistance, impact resistance, cupping resistance and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of materials, and in particular relates to a high-thickness original automobile water-based B1 basecoat and a preparation method and application thereof. Background Art

[0002] In recent years, energy conservation and environmental protection have been the themes of world development. Automobile manufacturers around the world have invested a lot of money in research, continuously improving process equipment and upgrading process levels. Automobile painting is one of the main processes in automobile manufacturing, and its energy consumption accounts for about 60% of the total energy consumption in the automobile manufacturing process. Reducing energy consumption and pollutant emissions in the painting process are of great significance to protecting people's living environment. Therefore, the current automobile painting industry has begun to gradually transform from the traditional 3C2B process system to the compact process system, and B1B2 is a representative process among them.

[0003] The traditional 3C2B coating process is: electrophoresis (baking)─ midcoat (baking)─ color paint + varnish (baking); the main process of the water-based B1B2 process is: electrophoresis (baking)─ color paint 1 + color paint 2─ pre-baking─ varnish (baking). Compared with the traditional 3C2B process, the biggest advantage of the water-based B1B2 process is that it reduces the midcoat, midcoat drying and midcoat grinding, greatly shortening the process, reducing the process time and saving energy. Compared with traditional solvent-based coatings, the currently used B1B2 water-based coatings have the advantages of low organic solvent content, reduced VOC emissions, low harm to the human body, high safety, and the tools and equipment used for coating can be cleaned with water, and less solvent is used. CN106543825A discloses a water-based metallic glitter base paint, which includes 50-60 parts of acrylic emulsion, 20-25 parts of water-based aluminum powder slurry, 1-4 parts of butyl glycol butyl ether, 0.5-0.8 parts of silicone leveling agent, 20-25 parts of deionized water, 1-3 parts of neutralizer, and 0.1-0.6 parts of defoamer in terms of mass fraction. However, the water-based metallic glitter base paint provided by the invention is not necessarily suitable for the water-based B1B2 process. The difficulty of controlling the quality of the paint film in the water-based B1B2 process is much higher than that of the traditional 3C2B process. The original water-based B1 base paint of the prior art has high requirements on the roughness of the body substrate, and is prone to defects such as orange peel defects on the paint surface and poor stone impact resistance. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a high-thickness automobile original water-based B1 basecoat and a preparation method and application thereof. The high-thickness automobile original water-based B1 basecoat provided by the present invention has the properties of a mid-coat as a basecoat, and is compatible with the problem of excessively high requirements for substrate roughness, thereby improving the appearance qualification rate. The paint film obtained by the present invention has excellent performance, strong operability, good flatness, stronger mechanical properties, good stone impact resistance, good hiding power and filling properties, and excellent impact resistance and cupping resistance.

[0005] The technical solution of the present invention is:

[0006] A high-film thickness automotive original water-based B1 basecoat, comprising the following components and their mass fractions:

[0007] 15-25 parts of acrylic modified high molecular weight polyurethane, 5-10 parts of water-based acrylic resin emulsion, 5-15 parts of modified high molecular weight polyester, 4-8 parts of amino resin, 1-1.5 parts of surfactant, 1-1.5 parts of thickener, 0.2-0.5 parts of defoamer, 1-1.5 parts of dispersant, 0.5-1.5 parts of wetting and leveling agent, 15-25 parts of pigment, 1-1.5 parts of talc, 0.5-1 part of fumed silica, 0.5-2 parts of pH adjuster, 1-5 parts of ethylene glycol butyl ether, 2-8 parts of cosolvent, and 15-25 parts of water.

[0008] Furthermore, the high-thickness original automobile water-based B1 basecoat comprises the following components and their mass fractions:

[0009] 20 parts of acrylic modified high molecular weight polyurethane, 5 parts of water-based acrylic resin emulsion, 10 parts of modified high molecular weight polyester, 5 parts of amino resin, 1.5 parts of surfactant, 1.5 parts of thickener, 0.3 parts of defoamer, 1 part of dispersant, 0.5 parts of wetting and leveling agent, 20 parts of pigment, 1 part of talc, 0.5 parts of fumed silica, 2 parts of pH adjuster, 2 parts of ethylene glycol butyl ether, 4 parts of cosolvent, and 24.5 parts of water.

[0010] Furthermore, the acrylic acid modified high molecular weight polyurethane is allnex polyurethane resin 6466 / 36WA.

[0011] Furthermore, the modified high molecular weight polyester is a baking type water-based polyester resin WATERSOL ZHW-1346.

[0012] Furthermore, the co-solvent is one or both of isopropyl alcohol and isooctyl alcohol.

[0013] Furthermore, the co-solvent is composed of isopropanol and isooctyl alcohol in a mass ratio of 1-5:0-5.

[0014] Furthermore, the aqueous acrylic resin emulsion is an alkali-swellable aqueous acrylic resin emulsion; the surfactant is an acetylene glycol surfactant; the thickener is an alkali-thickening thickener; and the pH adjuster is dimethylethanolamine.

[0015] Furthermore, the dispersant is BYK-192 dispersant; and the wetting and leveling agent is BYK-345 wetting and leveling agent.

[0016] In addition, the present invention also provides a method for preparing a high-film thickness original automobile water-based B1 basecoat, the steps of which are as follows:

[0017] (1) Take the main cylinder A, add the formulated amount of acrylic modified high molecular weight polyurethane, modified high molecular weight polyester, 80% of the formulated amount of pH adjuster, water-based acrylic resin emulsion, and amino resin in sequence, and stir at a speed of 300 to 600 rpm for 15 to 20 minutes;

[0018] (2) Take another auxiliary cylinder B, add 40% of the formula amount of water, defoamer, dispersant, ethylene glycol butyl ether, pigment, talcum powder, and fumed silica in sequence, and grind to a fineness of less than 5 μm at 900 to 1200 rpm, a temperature below 40° C., and a flow rate of 10 to 15 L / min to obtain a primer slurry;

[0019] (3) After the primer slurry obtained in step (2) is cooled to room temperature, it is added to the main cylinder A of step (1), stirred at a speed of 300 to 600 rpm for 5 to 15 minutes, and a wetting and leveling agent, a surfactant, and a thickener in a prescribed amount are added, and stirred at a speed of 300 to 600 rpm for 15 to 20 minutes;

[0020] (4) Add the formulated amount of the co-solvent, the remaining amount of the pH adjuster, and the remaining amount of water into the main cylinder A of step (3), and stir at a speed of 600 to 900 rpm for 20 to 30 minutes to obtain the product.

[0021] Another object of the present invention is to provide the application of the high-film thickness automobile original water-based B1 basecoat in the automobile B1B2 compact coating process.

[0022] The difficulty of controlling the quality of the paint film in the water-based B1B2 process is much higher than that in the traditional 3C2B process. First of all, in the original B1B2 process of automobile factories, B1 usually needs to be applied thinly, with a film thickness in the range of 10-14um. The reasons for thin application include: thin application will result in better flatness; fast drying speed can prevent the B1 primer from being bitten by the topcoat. If the paint film is thicker, the following problems will occur: (1) The B1 primer and the topcoat B2 coating will dissolve in wet-to-wet conditions, which will cause local or even large-scale loss of gloss in the paint film, which will have a great impact on the appearance of the entire topcoat; (2) The microscopic unevenness of the substrate is transmitted to the paint surface; (3) The solvent evaporates during the paint drying process, causing the surface tension gradient to form Bénard vortices; these will have a great impact on the flatness of the composite coating; (4) B1 color paint has the properties of topcoat. Since B1 color paint is thin, it has higher requirements on the roughness of the body substrate and is more likely to produce orange peel defects on the paint surface. Therefore, the film thickness needs to be strictly controlled during the construction process, and higher requirements are also placed on the performance of the matching coating. Thirdly, since there is no interface between the B1 layer and the topcoat B2 coating, the coating's ability to absorb impact energy decreases, thereby increasing the probability of damage from stone fragments hitting the surface of the vehicle body steel plate, resulting in poor stone impact resistance.

[0023] In view of the above technical difficulties, the present invention innovatively adopts modified high molecular weight polyester and acrylic modified high molecular weight polyurethane as the main body through a large number of creative experiments, and improves the pigment-to-base ratio (the ratio of pigment to resin in the coating). The B1 base paint is designed to have a certain filling property when applied thickly. As a base paint, it also has the properties of a middle coating, and is compatible with the problem of excessive demand for substrate roughness, thereby improving the appearance qualification rate; a paint film with stronger operability, flatness, mechanical properties, stone impact resistance, wider color matching, better hiding power and filling, and better impact resistance and cupping resistance can be obtained. The present invention solves the technical difficulties existing in the above-mentioned water-based B1B2 process by adding fumed silica and talcum powder, while improving the pigment-to-base ratio, adding modified high molecular weight polyester to improve appearance leveling and maintain important performance.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] (1) The high-thickness automotive original water-based B1 basecoat provided by the present invention has the properties of a mid-coat as a basecoat, and is compatible with the problem of excessively high requirements for substrate roughness, thereby improving the appearance qualification rate;

[0026] (2) The present invention has strong compatibility and can be used with various color paints of the original automobile B1B2 process. The light transmittance of the coating meets the relevant technical requirements.

[0027] (3) In the B1B2 process of the original automobile, B1 usually needs to be applied thinly, with a film thickness in the range of 10-14um, while the film thickness of the present invention is in the range of 20-25um, and the technical difficulties of thick paint films in the prior art are overcome. The paint film obtained by the present invention has excellent performance, strong operability, good flatness, stronger mechanical properties, good stone impact resistance, wider color matching, better hiding power and filling, better impact resistance and cupping resistance, low organic volatiles (VOC), meets national environmental protection requirements, is green and environmentally friendly, and meets the paint film index requirements of the original automobile paint. DETAILED DESCRIPTION

[0028] The present invention is further illustrated below through the description of specific implementation modes, but this is not a limitation of the present invention. Those skilled in the art can make various modifications or improvements based on the basic idea of ​​the present invention, but as long as they do not deviate from the basic idea of ​​the present invention, they are all within the scope of the present invention.

[0029] The purchasing information of each raw material in the following examples and comparative examples is shown in Table 1.

[0030] Table 1: Purchase information of each raw material

[0031]

[0032]

[0033] Example 1: A high-film-thickness original automobile water-based B1 basecoat

[0034] The high-thickness original automobile water-based B1 basecoat comprises the following components and their weight fractions: 15 parts of acrylic acid-modified high molecular weight polyurethane, 5 parts of water-based acrylic resin emulsion, 5 parts of modified high molecular weight polyester, 4 parts of amino resin, 1 part of surfactant, 1 part of thickener, 0.2 parts of defoamer, 1 part of BYK-192 dispersant, 0.5 parts of BYK-345 wetting and leveling agent, 15 parts of pigment, 1 part of talc, 0.5 parts of fumed silica, 0.5 parts of pH adjuster, 1 part of ethylene glycol butyl ether, 2 parts of cosolvent, and 15 parts of water; the acrylic acid-modified high molecular weight polyurethane is Allnex polyurethane resin 6466 / 36WA; the modified high molecular weight polyester is a baking type water-based polyester resin WATERSOL ZHW-1346; the cosolvent is composed of isopropyl alcohol and isooctyl alcohol in a mass ratio of 1:5; the water-based acrylic resin emulsion is an alkali-swellable water-based acrylic resin emulsion; the surfactant is an acetylene glycol surfactant; the thickener is an alkali-thickening thickener; the fumed silica is Evonik AEROSIL R972; and the pH adjuster is dimethylethanolamine.

[0035] The preparation method of high film thickness original automobile water-based B1 basecoat is as follows:

[0036] (1) Take the main cylinder A, add the formula amount of acrylic modified high molecular weight polyurethane, modified high molecular weight polyester, 80% of the formula amount of pH adjuster, water-based acrylic resin emulsion, and amino resin in sequence, and stir at a speed of 300 rpm for 15 minutes;

[0037] (2) Take another auxiliary cylinder B, add 40% of the formula amount of water, defoamer, dispersant, ethylene glycol butyl ether, pigment, talcum powder, and fumed silica in sequence, and grind to a fineness of less than 5 μm at 900 rpm, a temperature of less than 40° C., and a flow rate of 10 L / min to obtain a primer slurry;

[0038] (3) After the primer slurry obtained in step (2) is cooled to room temperature, it is added to the main cylinder A of step (1), stirred at a speed of 3000 rpm for 5 minutes, and the formulated amount of wetting and leveling agent, surfactant, and thickener is added, and stirred at a speed of 300 rpm for 15 minutes;

[0039] (4) Add the formulated amount of the co-solvent, the remaining amount of the pH adjuster, and the remaining amount of water into the main cylinder A of step (3), and stir at a speed of 600 rpm for 20 minutes to obtain the product.

[0040] Example 2: A high-film-thickness original water-based B1 basecoat for automobiles

[0041] The high-thickness original automobile water-based B1 basecoat comprises the following components and their weight fractions: 25 parts of acrylic acid-modified high-molecular-weight polyurethane, 10 parts of water-based acrylic resin emulsion, 15 parts of modified high-molecular-weight polyester, 8 parts of amino resin, 1.5 parts of surfactant, 1.5 parts of thickener, 0.5 parts of defoamer, 1.5 parts of BYK-192 dispersant, 1.5 parts of BYK-345 wetting and leveling agent, 25 parts of pigment, 1.5 parts of talc, 1 part of fumed silica, 2 parts of pH regulator, 5 parts of ethylene glycol butyl ether, 8 parts of cosolvent, and 25 parts of water; the acrylic acid-modified high-molecular-weight polyurethane is Allnex polyurethane resin 6466 / 36WA; the modified high molecular weight polyester is a baking type water-based polyester resin WATERSOL ZHW-1346; the cosolvent is isopropyl alcohol; the water-based acrylic resin emulsion is an alkali-swellable water-based acrylic resin emulsion; the surfactant is an acetylene glycol surfactant; the thickener is an alkali-thickening thickener; the fumed silica is Evonik AEROSIL R972; and the pH adjuster is dimethylethanolamine.

[0042] The preparation method of high film thickness original automobile water-based B1 basecoat is as follows:

[0043] (1) Take the main cylinder A, add the formula amount of acrylic modified high molecular weight polyurethane, modified high molecular weight polyester, 80% of the formula amount of pH adjuster, water-based acrylic resin emulsion, and amino resin in sequence, and stir at a speed of 600 rpm for 20 minutes;

[0044] (2) Take another auxiliary cylinder B, add 40% of the formula amount of water, defoamer, dispersant, ethylene glycol butyl ether, pigment, talcum powder, and fumed silica in sequence, and grind to a fineness of less than 5 μm at 1200 rpm, a temperature of less than 40° C., and a flow rate of 15 L / min to obtain a primer slurry;

[0045] (3) After the primer slurry obtained in step (2) is cooled to room temperature, it is added to the main cylinder A of step (1), stirred at a speed of 600 rpm for 15 minutes, and a wetting and leveling agent, a surfactant, and a thickener in a prescribed amount are added, and stirred at a speed of 600 rpm for 20 minutes;

[0046] (4) Add the formulated amount of the co-solvent, the remaining amount of the pH adjuster, and the remaining amount of water into the main cylinder A of step (3), and stir at a speed of 900 rpm for 30 minutes to obtain the product.

[0047] Example 3: A high-film-thickness original automobile water-based B1 basecoat

[0048] The high-thickness original automobile water-based B1 basecoat comprises the following components and their weight fractions: 20 parts of acrylic acid-modified high molecular weight polyurethane, 5 parts of water-based acrylic resin emulsion, 10 parts of modified high molecular weight polyester, 5 parts of amino resin, 1.5 parts of surfactant, 1.5 parts of thickener, 0.3 parts of defoamer, 1 part of BYK-192 dispersant, 0.5 parts of BYK-345 wetting and leveling agent, 20 parts of pigment, 1 part of talcum powder, 0.5 parts of fumed silica, 2 parts of pH regulator, 2 parts of ethylene glycol butyl ether, 4 parts of cosolvent, and 24.5 parts of water; the acrylic acid-modified high molecular weight polyurethane is Allnex polyurethane resin 6466 / 36WA; the modified high molecular weight polyester is a baking type water-based polyester resin WATERSOL ZHW-1346; the cosolvent is isopropyl alcohol; the water-based acrylic resin emulsion is an alkali-swellable water-based acrylic resin emulsion; the surfactant is an acetylene glycol surfactant; the thickener is an alkali-thickening thickener; the fumed silica is Evonik AEROSIL R972; and the pH adjuster is dimethylethanolamine.

[0049] The preparation method of high film thickness original automobile water-based B1 basecoat is as follows:

[0050] (1) Take the main cylinder A, add the formula amount of acrylic modified high molecular weight polyurethane, modified high molecular weight polyester, 80% of the formula amount of pH adjuster, water-based acrylic resin emulsion, and amino resin in sequence, and stir at a speed of 500 rpm for 17 minutes;

[0051] (2) Take another auxiliary cylinder B, add 40% of the formula amount of water, defoamer, dispersant, ethylene glycol butyl ether, pigment, talcum powder, and fumed silica in sequence, and grind to a fineness of less than 5 μm at 1000 rpm, a temperature of less than 40° C., and a flow rate of 12 L / min to obtain a primer slurry;

[0052] (3) After the primer slurry obtained in step (2) is cooled to room temperature, it is added to the main cylinder A of step (1), stirred at a speed of 400 rpm for 10 minutes, and the formulated amount of wetting and leveling agent, surfactant, and thickener is added, and stirred at a speed of 400 rpm for 17 minutes;

[0053] (4) Add the formulated amount of the co-solvent, the remaining amount of the pH adjuster, and the remaining amount of water into the main cylinder A of step (3), and stir at a speed of 800 rpm for 25 minutes to obtain the product.

[0054] Comparative Example 1: A car original water-based B1 basecoat

[0055] The original water-based B1 basecoat for automobiles comprises the following components and their weight fractions: 20 parts of DSM polyurethane resin Neopac E-123, 5 parts of water-based acrylic resin emulsion, 10 parts of modified high molecular weight polyester, 5 parts of amino resin, 1.5 parts of surfactant, 1.5 parts of thickener, 0.3 parts of defoamer, 1 part of BYK-192 dispersant, 0.5 parts of BYK-345 wetting and leveling agent, 20 parts of pigment, 1 part of talcum powder, 0.5 parts of fumed silica, 2 parts of pH regulator, 2 parts of ethylene glycol butyl ether, 4 parts of cosolvent, and 24.5 parts of water; the modified high molecular weight polyester is a baking type water-based polyester resin WATERSOL ZHW-1346; the cosolvent is isopropanol; the water-based acrylic resin emulsion is an alkali-swellable water-based acrylic resin emulsion; the surfactant is an acetylene glycol surfactant; the thickener is an alkali-thickening thickener; the fumed silica is Evonik AEROSILR972; and the pH adjuster is dimethylethanolamine.

[0056] The preparation method of the original automobile water-based B1 basecoat is similar to that of Example 3.

[0057] The difference from Example 3 is that the allnex polyurethane resin TW6466 / 36WA was replaced by DSM polyurethane resin Neopac E-123.

[0058] Comparative Example 2: A car original water-based B1 basecoat

[0059] The original water-based B1 basecoat for automobiles comprises the following components and their weight fractions: 20 parts of acrylic acid-modified high molecular weight polyurethane, 5 parts of water-based acrylic resin emulsion, and 10 parts of alkyd resin. AZ 541w 42 / WA 10 parts, amino resin 5 parts, surfactant 1.5 parts, thickener 1.5 parts, defoamer 0.3 parts, BYK-192 dispersant 1 part, BYK-345 wetting and leveling agent 0.5 parts, pigment 20 parts, talcum powder 1 part, fumed silica 0.5 parts, pH adjuster 2 parts, ethylene glycol butyl ether 2 parts, cosolvent 4 parts, water 24.5 parts; the acrylic acid modified high molecular weight polyurethane is Allnex polyurethane resin TW 6466 / 36WA; the cosolvent is isopropanol; the aqueous acrylic resin emulsion is an alkali-swellable aqueous acrylic resin emulsion; the surfactant is an acetylene glycol surfactant; the thickener is an alkali-thickening thickener; the fumed silica is Evonik AEROSIL R972; and the pH adjuster is dimethylethanolamine.

[0060] The preparation method of the original automobile water-based B1 basecoat is similar to that of Example 3.

[0061] The difference from Example 3 is that the baking type waterborne polyester resin WATERSOL ZHW-1346 is replaced by the allnex alkyd resin AZ 541w 42 / WA.

[0062] Comparative Example 3: A car original water-based B1 basecoat

[0063] The high-thickness original automobile water-based B1 basecoat comprises the following components and their weight fractions: 20 parts of acrylic acid-modified high molecular weight polyurethane, 5 parts of water-based acrylic resin emulsion, 10 parts of modified high molecular weight polyester, 5 parts of amino resin, 1.5 parts of surfactant, 1.5 parts of thickener, 0.3 parts of defoamer, 1 part of BYK-192 dispersant, 0.5 parts of BYK-345 wetting and leveling agent, 20 parts of pigment, 1 part of talcum powder, 0.5 parts of Elementis DeuRheo 201P, 2 parts of pH regulator, 2 parts of ethylene glycol butyl ether, 4 parts of cosolvent, and 24.5 parts of water; the acrylic acid-modified high molecular weight polyurethane is Allnex polyurethane resin 6466 / 36WA; the modified high molecular weight polyester is a baking type water-based polyester resin WATERSOLZHW-1346; the cosolvent is isopropyl alcohol; the water-based acrylic resin emulsion is an alkali-swellable water-based acrylic resin emulsion; the surfactant is an acetylene glycol surfactant; the thickener is an alkali-thickening thickener; the fumed silica is Evonik AEROSIL R972; and the pH adjuster is dimethylethanolamine.

[0064] The preparation method of the original automobile water-based B1 basecoat is similar to that of Example 3.

[0065] The difference from Example 3 is that the fumed silica is replaced by Elementis DeuRheo 201P.

[0066] Comparative Example 4: A high-film-thickness original automotive water-based B1 basecoat

[0067] The high-thickness original water-based B1 basecoat for automobiles comprises the following components and their weight fractions: 20 parts of acrylic acid-modified high-molecular-weight polyurethane, 5 parts of water-based acrylic resin emulsion, 10 parts of modified high-molecular-weight polyester, 5 parts of amino resin, 1.5 parts of surfactant, 1.5 parts of thickener, 0.3 parts of defoamer, 1 part of BYK-192 dispersant, 0.5 parts of BYK-345 wetting and leveling agent, 20 parts of pigment, 0.5 parts of talc, 1 part of fumed silica, 2 parts of pH regulator, 2 parts of ethylene glycol butyl ether, 4 parts of cosolvent, and 24.5 parts of water; the acrylic acid-modified high-molecular-weight polyurethane is Allnex polyurethane resin 6466 / 36WA; the modified high molecular weight polyester is a baking type water-based polyester resin WATERSOL ZHW-1346; the cosolvent is isopropyl alcohol; the water-based acrylic resin emulsion is an alkali-swellable water-based acrylic resin emulsion; the surfactant is an acetylene glycol surfactant; the thickener is an alkali-thickening thickener; the fumed silica is Evonik AEROSIL R972; and the pH adjuster is dimethylethanolamine.

[0068] The preparation method of the original automobile water-based B1 basecoat is similar to that of Example 3.

[0069] The difference from Example 3 is that the mass fraction of talc is adjusted from 1 part to 0.5 part, and the mass fraction of fumed silica is adjusted from 0.5 part to 1 part.

[0070] Test Example 1: Performance Test

[0071] 1. Test materials: high-film thickness original automobile water-based B1 basecoat prepared in Example 1, Example 2, and Example 3, and original automobile water-based B1 basecoat prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4.

[0072] 2. The test items and methods are shown in Table 2.

[0073] Table 2 Test items and test methods

[0074]

[0075]

[0076] 3. The test results are shown in Table 3.

[0077] Table 3 Comprehensive performance test results of the present invention

[0078]

[0079]

[0080] Table 4 Comprehensive performance test results of comparative examples 1-4

[0081]

[0082]

[0083]

[0084] It can be seen from Table 3 that, according to the reasonable combination and ratio of each component, the high-thickness automobile original water-based B1 basecoat prepared in Examples 1 to 3 of the present invention has an adhesion of level 0, high hardness, good water resistance, strong impact resistance, strong crack resistance, good acid resistance, alkali resistance, moisture and heat resistance, and excellent storage stability, stone impact resistance, aging resistance and other properties.

[0085] From the comparison between Table 3 and Table 4, it can be seen that compared with Comparative Examples 1 to 4, changing the formula materials or proportions will lead to a serious decrease in key performance, highlighting the synergistic effect of the components in the high-thickness original automobile water-based B1 basecoat prepared by the present invention, and having more excellent comprehensive performance.

Claims

1. A high-film thickness automotive original water-based B1 basecoat, characterized in that: Includes the following components and their mass fractions: 15-25 parts of acrylic modified high molecular weight polyurethane, 5-10 parts of water-based acrylic resin emulsion, 5-15 parts of modified high molecular weight polyester, 4-8 parts of amino resin, 1-1.5 parts of surfactant, 1-1.5 parts of thickener, 0.2-0.5 parts of defoamer, 1-1.5 parts of dispersant, 0.5-1.5 parts of wetting and leveling agent, 15-25 parts of pigment, 1-1.5 parts of talc, 0.5-1 part of fumed silica, 0.5-2 parts of pH adjuster, 1-5 parts of ethylene glycol butyl ether, 2-8 parts of cosolvent, and 15-25 parts of water.

2. The high-thickness automotive original water-based B1 basecoat according to claim 1, characterized in that: Includes the following components and their mass fractions: 20 parts of acrylic modified high molecular weight polyurethane, 5 parts of water-based acrylic resin emulsion, 10 parts of modified high molecular weight polyester, 5 parts of amino resin, 1.5 parts of surfactant, 1.5 parts of thickener, 0.3 parts of defoamer, 1 part of dispersant, 0.5 parts of wetting and leveling agent, 20 parts of pigment, 1 part of talc, 0.5 parts of fumed silica, 2 parts of pH adjuster, 2 parts of ethylene glycol butyl ether, 4 parts of cosolvent, and 24.5 parts of water.

3. The high-thickness automotive original water-based B1 basecoat according to claim 1 or 2, characterized in that: The acrylic acid modified high molecular weight polyurethane is an allnex polyurethane resin TW 6466 / 36WA.

4. The high-thickness automotive original water-based B1 basecoat according to claim 1 or 2, characterized in that: The modified high molecular weight polyester is a baking type waterborne polyester resin WATERSOL ZHW-1346.

5. The high-thickness original automobile water-based B1 basecoat according to claim 1 or 2, characterized in that: The co-solvent is one or both of isopropanol and isooctyl alcohol.

6. The high-thickness original automobile water-based B1 basecoat according to claim 5, characterized in that: The co-solvent is composed of isopropanol and isooctyl alcohol in a mass ratio of 1-5:0-5.

7. The high-thickness automotive original water-based B1 basecoat according to claim 1 or 2, characterized in that: The aqueous acrylic resin emulsion is an alkali swelling type aqueous acrylic resin emulsion; the surfactant is an acetylene glycol surfactant; the thickener is an alkali thickening type thickener; and the pH adjuster is dimethylethanolamine.

8. The high-thickness original automobile water-based B1 basecoat according to claim 1 or 2, characterized in that: The dispersant is BYK-192 dispersant; the wetting and leveling agent is BYK-345 wetting and leveling agent.

9. The method for preparing the high-thickness original automobile water-based B1 basecoat according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Take the main cylinder A, add the formulated amount of acrylic modified high molecular weight polyurethane, modified high molecular weight polyester, 80% of the formulated amount of pH adjuster, water-based acrylic resin emulsion, and amino resin in sequence, and stir at a speed of 300 to 600 rpm for 15 to 20 minutes; (2) Take another auxiliary cylinder B, add 40% of the formula amount of water, defoamer, dispersant, ethylene glycol butyl ether, pigment, talcum powder, and fumed silica in sequence, and grind to a fineness of less than 5 μm at 900 to 1200 rpm, a temperature below 40° C., and a flow rate of 10 to 15 L / min to obtain a primer slurry; (3) After the primer slurry obtained in step (2) is cooled to room temperature, it is added to the main cylinder A of step (1), stirred at a speed of 300 to 600 rpm for 5 to 15 minutes, and a wetting and leveling agent, a surfactant, and a thickener in a prescribed amount are added, and stirred at a speed of 300 to 600 rpm for 15 to 20 minutes; (4) Add the formulated amount of the co-solvent, the remaining amount of the pH adjuster, and the remaining amount of water into the main cylinder A of step (3), and stir at a speed of 600 to 900 rpm for 20 to 30 minutes to obtain the product.

10. Use of the high-thickness automobile original water-based B1 basecoat according to any one of claims 1 to 8 in automobile B1B2 compact coating process.

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