OEM factory paint for integrated coating of vehicle body and plastic components, and integrated coating method

Abstract

An original equipment manufacturer (OEM) factory paint for integrated coating of a vehicle body and plastic components, and an integrated coating method. The OEM factory paint comprises a primer, a basecoat, and a clearcoat. According to the OEM factory paint for integrated coating of a vehicle body and plastic components, in the formulation of the primer, an aqueous IPDI curing agent is added to a conventional 1K waterborne surfacer primer, and then under the action of a guanidine-based catalyst, the primer can be rapidly cured at 70-80°C, thereby increasing the overall crosslinking density of a paint film, so that the paint film satisfies the mechanical property requirements specified by OEMs for OEM coatings; and in addition, by applying the same primer to plastic components, excellent mechanical properties are achieved, thereby allowing a vehicle body and a bumper to use the same surfacer, basecoat, and clearcoat to satisfy the performance requirements of integrated coating.

Description

An OEM original paint and integrated coating method for integrated coating of vehicle body and plastic parts Technical Field

[0001] This invention relates to the field of automobile manufacturing technology, specifically to an OEM original paint and an integrated coating method for the integrated coating of car bodies and plastic parts. Background Technology

[0002] In modern automotive manufacturing, painting the car body and plastic components is a crucial process. Painting not only protects the car body and components from environmental damage, extending their lifespan, but also enhances the car's appearance, thereby increasing consumer willingness to purchase.

[0003] In traditional painting processes, car bodies typically use water-based 3C1B (Three-Coat One-Bake) or B1B2 (Basecoat One-Bake, Basecoat Two-Bake) processes, baked at 145°C to 150°C; while plastic parts usually use solvent-based 3C1B paint, baked at 80°C. These paints release large amounts of organic solvents during use, posing harm to the environment and human health. Furthermore, because the car body and bumpers are painted separately, color matching takes a significant amount of time and frequently results in color discrepancies.

[0004] To reduce energy consumption and achieve energy conservation and emission reduction during the baking process at OEMs, lowering the baking temperature from 145℃ to 80℃ can save significant energy costs. Therefore, low-temperature environmentally friendly water-based coatings have gradually become a research and application hotspot. Low-temperature water-based paints, due to their ability to cure at 80℃, significantly reduce energy consumption and improve production efficiency, have received widespread attention. Currently, the main approach is to improve coating efficiency and quality by refining the formulation of 1K low-temperature plastic parts coatings and optimizing the coating process. For example, adding specific additives can improve the leveling and adhesion of the coating, thereby improving coating quality; furthermore, optimizing coating process parameters, such as adjusting coating temperature, humidity, and speed, can improve the uniformity and stability of the coating.

[0005] Despite the progress made in existing technologies, some problems still exist in practical applications:

[0006] 1. Performance Limitations: Existing low-temperature waterborne coatings are mainly based on the 1K system, which can meet the basic performance requirements for plastic parts, but has limitations for OEM body performance. Specifically, the paint film hardness is relatively soft (2B cannot reach H), and the chemical resistance and scratch resistance are poor. The main reason is that the curing speed of 1K waterborne intermediate coats and other layers is slow under low-temperature baking, resulting in insufficient cross-linking reaction. The paint film often needs to be cured for 7 days before its performance can be tested.

[0007] 2. Process complexity: The existing separate painting process for the car body and components is complex, requiring multiple color adjustments and matching, which increases production costs and time.

[0008] Summary of the Invention

[0009] In view of the deficiencies in the prior art, the purpose of this invention is to provide an OEM original paint for integrated coating of vehicle body and plastic parts. In addition, this invention also provides an integrated coating method, which uses the above-mentioned OEM original paint for integrated coating of vehicle body and plastic parts.

[0010] The first aspect of the present invention provides an OEM original paint for integrated coating of vehicle body and plastic parts, the OEM original paint including primer, color paint and clear coat;

[0011] The varnish comprises the following raw materials by weight: 85 wt% waterborne resin, 5 wt% DPM, 0.2 wt% SURFNOL 104BC, 0.2 wt% TWIN4100, 0.1 wt% to 0.5 wt% guanidine catalyst, 10 wt% DI Water, and 50 wt% isocyanate;

[0012] The primer comprises the following raw materials by weight: 72wt% HAE-1391, 1wt% DMEA aqueous solution, 0.1wt% to 1wt% guanidine catalyst, 0.5wt% Byk 028, 5wt% DPNB, 15wt% water, and 45wt% Bayhydur 401-70; or, the primer comprises the following raw materials by weight: 35wt% HAE-1391, 30wt% UH-2110, 1wt% DMEA aqueous solution, 0.1wt% to 1wt% guanidine catalyst, 0.5wt% Byk 028, 5wt% DPNB, 15wt% DI water, and 55wt% Bayhydur 401-70.

[0013] In one embodiment, the guanidine catalyst is prepared from the following raw materials in the indicated mass fractions: 5 wt% to 20 wt% cobalt chloride, 5 wt% to 20 wt% lanthanum oxide, 15 wt% to 30 wt% guanidine hydrochloride, 20 wt% to 30 wt% ethanol, and 15 wt% to 30 wt% water.

[0014] In one embodiment, the preparation of the guanidine catalyst includes the following steps:

[0015] Weigh out the prescribed amounts of cobalt chloride, lanthanum oxide, guanidine hydrochloride, ethanol, and water;

[0016] Cobalt chloride is added to ethanol and stirred slowly to dissolve it, thus obtaining a cobalt salt solution.

[0017] Lanthanum chloride was added to ethanol and stirred slowly to dissolve it, thus obtaining a lanthanum salt solution.

[0018] Add water to a four-necked flask, purge with nitrogen gas, heat to 60°C, add guanidine hydrochloride, stir slowly to dissolve, and then heat to 90°C to obtain a guanidine compound solution.

[0019] Under stirring, the cobalt salt solution was slowly added dropwise to the guanidine compound solution. After the addition was complete, stirring was continued for 30 minutes, followed by the slow addition of the lanthanum salt solution. After the addition was complete, the mixture was stirred at 90°C for 12 hours, cooled to room temperature, filtered, and washed to obtain the guanidine catalyst.

[0020] In one embodiment, the paint is a PUA paint or a PUD paint.

[0021] In one embodiment, the paint comprises raw materials containing the following mass fractions: 18wt%-25wt% DWOTAN6462, 10wt%-20wt% DAOTAN TW 1237, 10wt%-20wt% NeoPac E-123, 5wt%-10wt% CYMEL325, 10wt%-20wt% KNT water-based resin-free white paste, 0.2wt%-0.5wt% Twin4100, 0.2wt%-0.5wt% Surfynol 104E, 3wt%-7wt% co-solvent, and 5wt%-10wt% pure water.

[0022] The second aspect of the present invention provides an integrated coating method, which uses the above-mentioned OEM original paint to perform integrated coating on the car body and plastic parts.

[0023] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0024] 1. The OEM original paint provided by this invention includes a primer, a color coat, and a clear coat. The primer formula is made by adding a water-based IPDI curing agent to the original 1K water-based intermediate primer. Under the action of a guanidine catalyst, it can be rapidly cured at 70-80℃, which improves the overall cross-linking density of the paint film, thereby enabling the paint film to meet the mechanical performance requirements of the OEM coating. In addition, the same primer is used on plastic parts, resulting in excellent mechanical properties. This allows the use of the same intermediate coat, color coat, and clear coat on the body and bumper to achieve the performance requirements of integrated coating.

[0025] 2. This invention utilizes low-temperature water-based paint in OEM original paints, reducing the curing temperature from the initial 140℃ to 80℃. Compared to the high-temperature curing of traditional high-temperature water-based paints or solvent-based coatings, this significantly reduces energy consumption, improves production efficiency, and also enhances crosslinking density and mechanical properties compared to existing 1K low-temperature paints.

[0026] 3. This invention achieves integrated painting of the car body and plastic parts, reducing the number of color matching steps, simplifying the painting process, and thus reducing the overall production cost.

[0027] 4. This invention uses 2K low-temperature water-based paint, which avoids the harm to the environment and human health caused by the release of a large amount of organic solvents during the use of traditional solvent-based coatings, and is in line with the current trend of green and environmentally friendly development.

[0028] 5. The product performance of this invention can not only meet the mechanical performance requirements of the original manufacturer, but also improve the performance and quality of the paint film on plastic parts, reduce the customer's paint delivery system, and significantly improve the performance of the paint film.

[0029] 6. The coating baking temperature of the present invention is 80℃ for 30 minutes, which is significantly lower than the traditional 140℃ for 30 minutes. This reduces the oven temperature, which is beneficial for energy conservation and emission reduction and meets the current social demand for environmental protection and energy saving. Attached Figure Description

[0030] Figure 1 shows a photograph of the water resistance of the paint film;

[0031] Figure 2 shows the state of the paint film after high-pressure water rinsing. Detailed Implementation

[0032] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0033] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] The existing OEM original factory paint has the following main technical problems: 1) Conventional low-temperature water-based paints have a slow curing speed at low temperatures, and the paint film hardness is only 2B, which is relatively soft and affects production efficiency; 2) Existing product performance cannot meet the mechanical performance requirements of the car body and bumper; 3) Existing car body and bumper are painted separately, which is a complex process that requires multiple color matching and adjustment, increasing production costs and time; 4) Existing painting processes, especially for the car body, require baking at temperatures above 140℃, resulting in high equipment energy consumption and hindering energy conservation and emission reduction.

[0035] In view of the above problems, the present invention proposes an OEM original paint for integrated coating of vehicle body and plastic parts, and a method for integrated coating of vehicle body and plastic parts using the OEM original paint.

[0036] This invention proposes a guanidine catalyst. When a water-based IPDI curing agent is added to the original 1K water-based intermediate primer, the guanidine catalyst enables it to cure rapidly at 70-80℃, increasing the overall crosslinking density of the paint film. This allows the paint film to meet the mechanical performance requirements of OEM coatings. Furthermore, the same primer can be used on plastic parts, resulting in excellent mechanical properties. This allows for the use of the same intermediate coat, color coat, and clear coat on the body and bumper, achieving integrated coating performance.

[0037] The integrated coating method proposed in this invention further employs a high-pressure airless sprayer with a spraying pressure set at 0.6 MPa, a spraying distance of 20 cm, a rotary cup speed of 50,000 rpm, and a spraying angle of 90°. This ensures the uniformity and quality of the coating. High-efficiency, low-energy-consumption coating equipment, such as electrostatic sprayers, can also be used to reduce energy consumption and achieve energy conservation and emission reduction. Simultaneously, by improving equipment design, such as using energy-saving motors and optimizing the equipment's insulation design, energy consumption can be further reduced.

[0038] The OEM original paint and integrated coating method for integrated coating of vehicle body and plastic parts provided by this invention can realize the application of low temperature water-based paint in OEM original paint, realize integrated coating of vehicle body and parts, reduce energy consumption and color difference matching times, improve production efficiency, and reduce production costs and time.

[0039] The present invention will be further described below through specific embodiments.

[0040] Example 1

[0041] This embodiment provides a guanidine catalyst, which is prepared by the following method:

[0042] Weigh out the prescribed amounts of cobalt chloride, lanthanum oxide, guanidine hydrochloride, ethanol, and water;

[0043] Add 10 grams of cobalt chloride to 15 grams of ethanol and stir slowly at 500-700 rpm to dissolve it, thus obtaining a cobalt salt solution.

[0044] Add 8 grams of lanthanum chloride to 12 grams of ethanol and stir slowly at 500-700 rpm to dissolve it, thus obtaining a lanthanum salt solution.

[0045] Add 25g of water to a four-necked flask, purge with nitrogen, heat to 60°C, add 25g of guanidine hydrochloride, dissolve at 200-300 rpm, then heat to 90°C to obtain a 50% concentration guanidine compound solution.

[0046] Under stirring, the cobalt salt solution was added dropwise to the guanidine compound solution over one hour. After the addition was complete, stirring was continued at 400-500 rpm for 30 minutes. Then, the lanthanum salt solution was added dropwise over one hour. After the addition was complete, the mixture was stirred at 90°C for 12 hours. The mixture was then cooled to room temperature, filtered, and washed to obtain the guanidine catalyst.

[0047] Example 2

[0048] This embodiment provides an OEM original paint for integrated coating of vehicle body and plastic parts, the OEM original paint including primer, color paint and clear coat.

[0049] The composition and content of the primer in this embodiment are shown in Table 1.

[0050] Table 1

[0051] The preparation method of the primer in this embodiment includes the following steps:

[0052] 1) Weigh 70g of HAE-1391 and add it to the main agent container. Stir at 100-200rpm. Add 5g of KNT resin-free primer mortar and stir at 300-500rpm for 30 minutes. After stirring evenly, add 1g of DMEA 10% in DI water solution and adjust the pH to 8.5-9.

[0053] 2) Take another container, add 0.5 g of KNTC59 catalyst, add 0.5 g of Byk 028 additive while stirring, add 5 g of DPNB co-solvent, mix well and then put it into the main agent tank, stir for 10 minutes; then add 10-15 g of pure water to adjust the viscosity.

[0054] 3) Weigh 100g of the main agent mixture, add 45g of Bayhydur 401-70 hardener, stir at 100rpm for 10min, and after mixing evenly, you will get the primer application liquid, ready to be used with color paint and clear varnish.

[0055] The composition and content of the varnish in this embodiment are shown in Table 2.

[0056] Table 2

[0057] The preparation method of the varnish in this embodiment includes the following steps:

[0058] 1) Weigh 85 grams of SETAQUA6511 and add it to the paint mixing tank, then turn on the stirrer at 100-200 rpm;

[0059] 2) In a separate small container, add 0.2 g of SURFNOL 104BC additive, 0.2 g of TWIN4100 additive, and 0.3 g of KNTC59 catalyst to 5 g of DPM solvent, stir well, and add to the paint mixing tank while stirring. Stir for 10 minutes.

[0060] 3) Use 10 grams of DI water to adjust the viscosity;

[0061] 4) Weigh 100g of clear varnish base agent and 50g of DESMODUR3390 isocyanate curing agent, stir at 100rpm for 10 minutes, and after mixing evenly, the clear varnish application liquid can be obtained.

[0062] The paint in this embodiment is a combination of water-based PUA and PUD low-temperature baking paint system. The paint contains the following raw materials by mass fraction: 22wt% DWOTAN6462, 17wt% DAOTAN TW 1237, 15wt% NeoPac E-123, 7wt% CYMEL325, 18wt% KNT water-based resin-free white paste, 0.3wt% Twin4100, 0.5wt% Surfynol 104E, 5wt% cosolvent, and the balance being pure water.

[0063] In this embodiment, the guanidine catalysts in the primer and varnish are the guanidine catalysts prepared in Example 1.

[0064] The process of applying the OEM original paint provided in this embodiment to the vehicle body and plastic parts in an integrated manner includes the following steps:

[0065] 1) Prepare PP and ABS sheets for the electrophoresis plate and plastic parts of the car body, and degrease the surface with isopropyl alcohol;

[0066] 2) Primer application: After the primer with hardener has been added, spray it onto the car body and bumpers to achieve a film thickness of 10-15 micrometers. The primer improves the adhesion of the coating and the car body's corrosion resistance.

[0067] 3) Wait for the primer to flash dry at room temperature for 5-8 minutes;

[0068] 4) Spray the colored paint, then pre-bake at 80℃ for 5-8 minutes to dehydrate;

[0069] 5) After dehydration, cool, spray with clear varnish with added curing agent, film thickness 35-40 microns, level for 8 minutes, bake at 80℃ for 30 minutes, no curing required, directly test and evaluate performance;

[0070] Example 3

[0071] This embodiment provides an OEM original paint for integrated coating of vehicle body and plastic parts, the OEM original paint including primer, color paint and clear coat.

[0072] The composition and content of the primer in this embodiment are shown in Table 3.

[0073] Table 3

[0074] The preparation method of the primer in this embodiment includes the following steps:

[0075] 1) Weigh 35g of HAE-1391 and add it to the main agent container. Stir at 100-200rpm. Add 30g of UH-2110. While stirring, add 5g of KNT resin-free primer mortar. Stir at 300-500rpm for 30 minutes. After stirring evenly, add 1g of DMEA 10% in DI water solution and adjust the pH to 8.5-9.

[0076] 2) In another container, add 1 gram of KNTC59 catalyst, add 0.5 grams of Byk 028 additive while stirring, and stir for 10 minutes; add 5 grams of DPNB co-solvent, mix well, and then add to the main agent container, and stir for 10 minutes; then add 15 grams of pure water to adjust the viscosity.

[0077] 3) Weigh 100g of the main agent and 55g of Bayhydur 401-70 hardener, stir at 100rpm for 10min, and after mixing evenly, you will get the primer application liquid, ready to be used with color paint and clear varnish.

[0078] The composition and preparation method of the varnish in this embodiment are the same as those in Example 2.

[0079] The paint in this embodiment is a combination of water-based PUA and PUD low-temperature baking paint system. The paint contains the following raw materials by mass fraction: 22wt% DWOTAN6462, 17wt% DAOTAN TW 1237, 15wt% NeoPac E-123, 7wt% CYMEL325, 18wt% KNT water-based resin-free white paste, 0.3wt% Twin4100, 0.5wt% Surfynol 104E, 5wt% cosolvent, and the balance being pure water.

[0080] In this embodiment, the guanidine catalysts in the primer and varnish are the guanidine catalysts prepared in Example 1.

[0081] The process of applying the OEM original paint provided in this embodiment to the vehicle body and plastic parts in an integrated manner includes the following steps:

[0082] 1) Prepare PP and ABS sheets for the electrophoresis plate and plastic parts of the car body, and degrease the surface with isopropyl alcohol;

[0083] 2) Primer application: After the primer with hardener has been added, spray it onto the car body and bumpers to achieve a film thickness of 10-15 micrometers. The primer improves the adhesion of the coating and the car body's corrosion resistance.

[0084] 3) Wait for the primer to flash dry at room temperature for 5-8 minutes;

[0085] 4) Spray the colored paint, then pre-bake at 80℃ for 5-8 minutes to dehydrate;

[0086] 5) After dehydration, cool, spray with clear varnish with added curing agent, film thickness 35-40 microns, level for 8 minutes, bake at 80℃ for 30 minutes, no curing required, directly test and evaluate performance;

[0087] Comparative Example 1

[0088] This comparative example provides an OEM original paint, which includes primer, color paint and clear coat.

[0089] The paint used in this embodiment is the same as that in Embodiment 1;

[0090] In this embodiment, neither the primer nor the clear coat contains a drying agent, and the reaction rate and mechanical properties of the paint film are compared.

[0091] The composition and content of the primer in this comparative example are shown in Table 4;

[0092] Table 4

[0093] The preparation method of the primer in this comparative example includes the following steps:

[0094] 1) Weigh 70g of HAE-1391 and add it to the main agent container. Stir at 100-200rpm. Add 5g of KNT resin-free primer mortar and stir at 300-500rpm for 30 minutes. After stirring evenly, add 1g of DMEA 10% in DI water solution and adjust the pH to 8.5-9.

[0095] 2) In another container, add 0.5g of Byk 028 additive and 5g of DPNB co-solvent, mix well and then put it into the main agent container, stir for 10 minutes; then add 10-15g of pure water to adjust the viscosity.

[0096] 3) Weigh 100g of the above mixture, add 45g of Bayhydur 401-70 hardener, stir at 100rpm for 10min, and after mixing evenly, you will get the primer application liquid, ready to be used with color paint and clear coat.

[0097] The composition and content of the varnish in this comparative example are shown in Table 5.

[0098] Table 5

[0099] The preparation method of the varnish in this comparative example includes the following steps:

[0100] 1) Weigh 85 grams of SETAQUA6511 and add it to the main agent container, then turn on the stirrer at 100-200 rpm;

[0101] 2) In a separate small container, mix 0.2 g of SURFNOL 104BC adjuvant and 0.2 g of TWIN4100 adjuvant evenly, and add them to the main agent container while stirring. Stir for 10 minutes.

[0102] 3) Use 10 grams of DI water to adjust the viscosity of the main agent.

[0103] 4) Weigh 100g of clear varnish base agent and 50g of DESMODUR3390 isocyanate curing agent, stir at 100rpm for 10 minutes, and after mixing evenly, the clear varnish application liquid can be obtained.

[0104] The paint in this comparative example is a low-temperature baking paint system combining water-based PUA and PUD. The paint contains the following raw materials by mass fraction: 22wt% DWOTAN6462, 17wt% DAOTAN TW 1237, 15wt% NeoPac E-123, 7wt% CYMEL325, 18wt% KNT water-based resin-free white paste, 0.3wt% Twin4100, 0.5wt% Surfynol 104E, 5wt% co-solvent, and the balance being pure water.

[0105] The process of applying an integrated coating to the vehicle body and plastic parts using the OEM original paint provided in this comparison example includes the following steps:

[0106] 1) Prepare PP and ABS sheets for the electrophoresis plate and plastic parts of the car body, and degrease the surface with isopropyl alcohol;

[0107] 2) Primer application: After the primer with hardener has been added, spray it onto the car body and bumpers to achieve a film thickness of 10-15 micrometers. The primer improves the adhesion of the coating and the car body's corrosion resistance.

[0108] 3) Wait for the primer to flash dry at room temperature for 5-8 minutes;

[0109] 4) Spray the colored paint, then pre-bake at 80℃ for 5-8 minutes to dehydrate;

[0110] 5) After dehydration, cool, spray with clear varnish with added curing agent, film thickness 35-40 microns, level for 8 minutes, bake at 80℃ for 30 minutes, no curing required, directly test and evaluate performance;

[0111] Comparative Example 2

[0112] This comparative example provides an OEM original paint, which includes primer, color paint and clear coat.

[0113] DBTDL drier was added to primer and clear coat, and the reaction rate and mechanical properties of the coating film were compared.

[0114] The composition and content of the primer in this comparative example are shown in Table 6.

[0115] Table 6

[0116] The preparation method of the primer in this comparative example includes the following steps:

[0117] 1) Weigh 70g of HAE-1391 and add it to the main agent container. Stir at 100-200rpm. Add 5g of KNT resin-free primer mortar and stir at 300-500rpm for 30 minutes. After stirring evenly, add 1g of DMEA 10% in DI water solution and adjust the pH to 8.5-9.

[0118] 2) In another container, add 0.5g of DBTDL drying agent, 0.5g of BYk 028 additive, and 5g of DPNB co-solvent. Mix well and then add to the main agent container. Stir for 10 minutes. Then add 10-15g of pure water to adjust the viscosity.

[0119] 3) Weigh 100g of the above mixture, add 45g of Bayhydur 401-70 hardener, stir at 100rpm for 10min, and after mixing evenly, you will get the primer application liquid, ready to be used with color paint and clear coat.

[0120] The composition and content of the varnish in this comparative example are shown in Table 7.

[0121] Table 7

[0122] The preparation method of the varnish in this comparative example includes the following steps:

[0123] 1) Weigh 85 grams of SETAQUA6511 and add it to the main agent container, then turn on the stirrer at 100-200 rpm;

[0124] 2) In a separate small container, mix 0.2 g of SURFNOL 104BC adjuvant, 0.2 g of TWIN4100 adjuvant, and 0.3 g of DBTDL drying agent. Add the mixture to the main agent container while stirring, and stir for 10 minutes.

[0125] 3) Use 10 grams of DI water to adjust the viscosity of the main agent;

[0126] 4) Weigh 100g of clear varnish base agent and 50g of DESMODUR3390 isocyanate curing agent, stir at 100rpm for 10 minutes, and after mixing evenly, the clear varnish application liquid can be obtained.

[0127] The paint in this comparative example is a low-temperature baking paint system combining water-based PUA and PUD. The paint contains the following raw materials by mass fraction: 22wt% DWOTAN6462, 17wt% DAOTAN TW 1237, 15wt% NeoPac E-123, 7wt% CYMEL325, 18wt% KNT water-based resin-free white paste, 0.3wt% Twin4100, 0.5wt% Surfynol 104E, 5wt% co-solvent, and the balance being pure water.

[0128] The OEM original paint provided in this comparative example is used for integrated painting of the car body and plastic parts, similar to Comparative Example 1.

[0129] Comparative Example 3

[0130] This comparative example provides an OEM original paint, which includes primer, color paint and clear coat.

[0131] Sn-based driers were added to primers and clear coats, and the reaction rate and mechanical properties of the coating films were compared.

[0132] The composition and content of the primer in this comparative example are shown in Table 8.

[0133] Table 8

[0134] The preparation method of the primer in this comparative example includes the following steps:

[0135] 1) Weigh 70g of HAE-1391 and add it to the main agent container. Stir at 100-200rpm. Add 5g of KNT resin-free primer mortar and stir at 300-500rpm for 30 minutes. After stirring evenly, add 1g of DMEA 10% in DI water solution and adjust the pH to 8.5-9.

[0136] 2) In another container, add 0.5g of Sn-type drying agent, 0.5g of BYk 028 additive, and 5g of DPNB cosolvent. Mix well and then add to the main agent container. Stir for 10 minutes. Then add 10-15g of pure water to adjust the viscosity.

[0137] 3) Weigh 100g of the above mixture, add 45g of Bayhydur 401-70 hardener, stir at 100rpm for 10min, and after mixing evenly, you will get the primer application liquid, ready to be used with color paint and clear coat.

[0138] The composition and content of the varnish in this comparative example are shown in Table 9.

[0139] Table 9

[0140] The preparation method of the varnish in this comparative example includes the following steps:

[0141] 1) Weigh 85 grams of SETAQUA6511 and add it to the main agent container, then turn on the stirrer at 100-200 rpm;

[0142] 2) In a separate small container, add 0.2 g of SURFNOL 104BC additive, 0.2 g of TWIN4100 additive, and 0.3 g of...

[0143] Add the Sn-type drying agent to the main agent container while stirring, and stir for 10 minutes.

[0144] 3) Use 10 grams of DI water to adjust the viscosity of the main agent;

[0145] 4) Weigh 100g of clear varnish base agent and 50g of DESMODUR3390 isocyanate curing agent, stir at 100rpm for 10 minutes, and after mixing evenly, the clear varnish application liquid can be obtained.

[0146] The paint in this comparative example is a water-based PUA and PUD combination low-temperature baking paint system. The paint contains the following raw materials by mass fraction: 22wt% DWOTAN6462, 17wt% DAOTAN TW 1237, 15wt% NeoPac E-123, 7wt% CYMEL325, 18wt% KNT water-based resin-free white paste, 0.3wt% Twin4100, 0.5wt% Surfynol 104E, 5wt% co-solvent, and the balance being pure water.

[0147] The OEM original paint provided in this comparative example is used for integrated painting of the car body and plastic parts, similar to Comparative Example 1.

[0148] Comparative Example 4

[0149] This comparative example provides an OEM original paint, which includes primer, color paint and clear coat.

[0150] Bi group driers were added to primers and clear coats, and the reaction rate and mechanical properties of the coating films were compared.

[0151] The composition and content of the primer in this comparative example are shown in Table 10.

[0152] Table 10

[0153] The preparation method of the primer in this comparative example includes the following steps:

[0154] 1) Weigh 70g of HAE-1391 and add it to the main agent container. Stir at 100-200rpm. Add 5g of KNT resin-free primer mortar and stir at 300-500rpm for 30 minutes. After stirring evenly, add 1g of DMEA 10% in DI water solution and adjust the pH to 8.5-9.

[0155] 2) In another container, add 0.5 g of Bi group drying agent, 0.5 g of BYk 028 additive, and 5 g of DPNB cosolvent. Mix well and then pour into the main agent container. Stir for 10 minutes. Then add 10-15 g of pure water to adjust the viscosity.

[0156] 3) Weigh 100g of the above mixture, add 45g of Bayhydur 401-70 hardener, stir at 100rpm for 10min, and after mixing evenly, you will get the primer application liquid, ready to be used with color paint and clear coat.

[0157] The composition and content of the varnish in this comparative example are shown in Table 11.

[0158] Table 11

[0159] The preparation method of the varnish in this comparative example includes the following steps:

[0160] 1) Weigh 85 grams of SETAQUA6511 and add it to the main agent container, then turn on the stirrer at 100-200 rpm;

[0161] 2) In a separate small container, add 0.2 g of SURFNOL 104BC additive, 0.2 g of TWIN4100 additive, and 0.3 g of...

[0162] Add the Bi group drying agent, stir well, and add it to the main agent container while stirring. Stir for 10 minutes.

[0163] 3) Use 10 grams of DI water to adjust the viscosity of the main agent;

[0164] 4) Weigh 100g of clear varnish base agent and 50g of DESMODUR3390 isocyanate curing agent, stir at 100rpm for 10 minutes, and after mixing evenly, the clear varnish application liquid can be obtained.

[0165] The paint in this comparative example is a low-temperature baking paint system combining water-based PUA and PUD. The paint contains the following raw materials by mass fraction: 22wt% DWOTAN6462, 17wt% DAOTAN TW 1237, 15wt% NeoPac E-123, 7wt% CYMEL325, 18wt% KNT water-based resin-free white paste, 0.3wt% Twin4100, 0.5wt% Surfynol 104E, 5wt% co-solvent, and the balance being pure water.

[0166] The OEM original paint provided in this comparative example is used for integrated painting of the car body and plastic parts, similar to Comparative Example 1.

[0167] Test case

[0168] This experimental example mainly describes the synthesis of KNTC59 guanidine driers in Example 1. Examples 2-3 describe the effects of different amounts of driers and slight differences in the main resin on the performance of OEM original paints. The performance of OEM original paints obtained in Comparative Examples 1-4 is tested. By adjusting different catalysts, the type and addition ratio of the paint film are verified, and its mechanical properties are poor.

[0169] The performance testing methods are as follows:

[0170] 1) The surface drying time test is conducted at room temperature and is the time it takes for the cotton ball to no longer stick.

[0171] 2) The paint film adhesion and pencil hardness were tested at 80℃ for 30 minutes.

[0172] 3) The water resistance of the paint film is the result of the test at 80℃ for 30 minutes, followed by a test at 40℃ for 10 days;

[0173] 4) The paint film is resistant to high-pressure water rinsing. After 30 minutes at 80℃, rinse with water at 90 bar water pressure, 70℃ water temperature, 10cm, and 30 seconds.

[0174] The test results are shown in Table 4. The performance comparison results show that all formulations containing driers can accelerate the curing of low-temperature paint films to varying degrees. However, the formulation containing KNTC59 catalyst has the shortest drying time from surface dry to fully dry, achieving the best performance. This also provides technical support for OEM original paint baking at a low temperature of 80℃.

[0175] Table 12

[0176] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An OEM original factory paint for integrated coating of vehicle body and plastic parts, characterized in that, The OEM original paint includes primer, color paint, and clear coat; The varnish comprises the following raw materials by weight: 80wt%-85wt% waterborne resin, 6wt%-8wt% DPM, 0.1wt%-0.5wt% SURFNOL 104 BC, 0.1wt%-0.5wt% TWIN4100, 0.1wt%-0.5wt% guanidine catalyst, 5wt%-10wt% DI Water, and 50wt%-60wt% isocyanate; The primer comprises the following raw materials by weight: 70wt%-75wt% HAE-1391, 1wt%-3wt% DMEA aqueous solution, 5wt%-10wt% KNT resin-free primer conductive paste, 0.1wt%-1wt% guanidine catalyst, 0.2%-0.5wt% Byk 028, 5wt%-8wt% DPNB, 10wt%-15wt% DI water, and 45wt%-50wt% Bayhydur 401-70; or, the primer comprises the following raw materials by weight: 30wt%-35wt% HAE-1391, 30wt%-40wt% UH-2110, 1wt%-2wt% DMEA aqueous solution, 0.1wt%-1wt% guanidine catalyst, 0.5wt%-1wt% Byk 028, 3wt%-5wt% DPNB, and 10wt%-15wt% DI water. Water, 50wt%-55wt%Bayhydur 401-70.

2. The OEM original paint for integrated coating of vehicle body and plastic parts according to claim 1, characterized in that, The guanidine catalyst is prepared from the following raw materials in the indicated mass fractions: 5 wt%–20 wt% cobalt chloride, 5 wt%–20 wt% lanthanum oxide, 15 wt%–30 wt% guanidine hydrochloride, 20 wt%–30 wt% ethanol, and 15 wt%–30 wt% water.

3. The OEM original paint for integrated coating of vehicle body and plastic parts according to claim 2, characterized in that, The preparation of the guanidine catalyst includes the following steps: Weigh out the prescribed amounts of cobalt chloride, lanthanum oxide, guanidine hydrochloride, ethanol, and water; Cobalt chloride was added to ethanol and stirred at 500-700 rpm to dissolve it, thus obtaining a cobalt salt solution. Lanthanum chloride was added to ethanol and stirred at 500-700 rpm to dissolve it, thus obtaining a lanthanum salt solution. Water was added to the reaction vessel, nitrogen gas was introduced, and the temperature was raised to 60°C. Guanidine hydrochloride was added and stirred at 200-300 rpm to dissolve it. Then the temperature was raised to 90°C to obtain a 50% concentration guanidine compound solution. Under stirring, the cobalt salt solution was added dropwise to the guanidine compound solution over one hour. After the addition was complete, the mixture was stirred at 400-500 rpm for 30 minutes. Then, the lanthanum salt solution was added dropwise over one hour. After the addition was complete, the mixture was stirred at 90°C for 12 hours. The mixture was then cooled to room temperature, filtered, and washed to obtain the guanidine catalyst.

4. The OEM original paint for integrated coating of vehicle body and plastic parts according to claim 1, characterized in that, The paint is a single-component PUA paint or PUD paint.

5. An integrated coating method, characterized in that, The vehicle body and plastic parts are coated with the OEM original paint as described in any one of claims 1-4.

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