Thermal insulation and noise reduction coating for vehicles, its preparation method and application on vehicles

Abstract

The application provides a heat-preserving and noise-reducing coating for vehicles, a preparation method thereof and application thereof on vehicles. The coating is prepared from the following raw materials in parts by mass: hollow microbeads 150-200, organic resin 120-140, preservative 1-3, thickening agent 8-10, multifunctional additive 1-2, film-forming additive 3-4 and deionized water 300-500. The coating uses hollow microbeads as the main raw material and appropriately increases the amount of thickening agent, so that the coating not only has the functions of heat preservation and noise reduction and excellent environmental protection performance, but also does not cause the wall-hanging phenomenon caused by the addition of a large amount of hollow microbeads in the spraying construction process, solves the problem that the coating easily flows when spraying at a thickness of more than 2 mm, and realizes one-time construction of a coating with a thickness of 1-5 mm in the spraying process of the heat-preserving and sound-insulating coating of the vehicle. The coating also has the characteristics of low cost and simple preparation process; the coating can be uniformly sprayed on the outer skin of the vehicle or the interior decoration of the vehicle by using the spraying method, and the construction is simple.

Description

Technical Field

[0001] This invention relates to the field of automotive materials technology, specifically to a heat-insulating and noise-reducing automotive coating, its preparation method, and its application in automobiles. Background Technology

[0002] There are many materials available for automotive insulation on the market. For special vehicles with high insulation performance requirements, such as those used in cold chain transportation, polyurethane spray coatings are generally chosen. This is mainly because polyurethane can be foamed in situ on the vehicle body substrate to form a closed-cell structure, and its interior is mainly composed of carbon dioxide gas, which partially turns into dry ice in low-temperature environments, forming a micro-vacuum structure that effectively blocks heat transfer. However, polyurethane's inherent pollution and difficulty in controlling foam thickness limit its application scenarios.

[0003] To address the aforementioned issues, Chinese patent application CN 116535909 A discloses a silica aerogel aqueous coating, its preparation method, and its application. The raw materials for preparing this silica aerogel aqueous coating include acrylic emulsion, silica aerogel dispersion, and a foaming agent; the raw materials for preparing the silica aerogel dispersion include hydrophobic silica aerogel, a dispersant, a coupling agent, a wetting agent, and water; the raw materials for preparing the silica aerogel aqueous coating also include at least one of titanium dioxide, mica powder, hollow glass microspheres, a film-forming aid, and a thickener. The silica aerogel aqueous coating disclosed in this patent application, after curing, forms a coating with excellent thermal insulation properties, as well as good adhesion and water resistance; however, due to the high cost of the aerogel used and the poor mechanical properties of the coating, the preparation of the coating requires pre-dispersion of the aerogel powder, making the process complex.

[0004] In addition, vehicles generate significant noise during operation, such as the loud noise from air compressors in refrigerated transport vehicles, reducing the comfort of drivers and passengers. To address this issue, hollow glass microspheres and other heat-insulating and noise-reducing coatings are typically added to aerogel coatings. Therefore, existing water-based heat-insulating and noise-reducing coatings for vehicles are relatively expensive and have complex manufacturing processes. Summary of the Invention

[0005] In view of this, the main objective of this invention is to provide an automotive thermal insulation and noise reduction coating, its preparation method, and its application in automobiles. This coating is aerogel-free, uses hollow microspheres as the main thermal insulation and noise reduction material, and features thermal insulation and noise reduction, low cost, and a simple preparation process. The coating can be uniformly sprayed onto the exterior or interior of a car using a simple application method.

[0006] Therefore, the first aspect of the present invention provides a vehicle heat insulation and noise reduction coating, the raw materials of which, by weight, include: 150-200 hollow microspheres, 120-140 organic resin, 1-3 preservatives, 8-10 thickeners, 1-2 multifunctional additives, 3-4 film-forming aids, and 300-500 deionized water.

[0007] The present invention also provides a method for preparing the above-mentioned automotive thermal insulation and noise reduction coating, comprising first mixing organic resin, deionized water, multifunctional additives, film-forming aids, and preservatives evenly; then adding hollow microspheres and stirring evenly; and then adding a thickener and stirring evenly.

[0008] A second aspect of this invention provides a method for applying the above-mentioned coating, wherein the automotive thermal insulation and noise reduction coating is sprayed onto the workpiece to form a thermal insulation and noise reduction coating layer. The thickness of the thermal insulation and noise reduction coating layer is 1-5 mm.

[0009] The present invention also provides an application of the above-mentioned coating in automobiles; further, it includes forming a thermal insulation and noise reduction coating formed of the above-mentioned coating between the automobile interior and the automobile exterior skin. The thermal insulation and noise reduction coating is formed by spraying it onto the interior of the automobile exterior skin.

[0010] Therefore, this invention uses hollow microspheres as a thermal insulation and noise reduction coating for automobiles, resulting in low cost; it only requires uniform mixing of raw materials to prepare the coating, and the preparation process and application are environmentally friendly. Compared with the existing technology where the amount of thickener is 0.1%-0.3% of the total mass of other raw materials, the amount of thickener used in this invention is 0.9%-1.5% of the total mass of the remaining raw materials in the coating. The significantly larger amount of thickener gives the automotive thermal insulation and noise reduction coating a certain degree of viscosity, preventing excessive residue buildup on the spray container during spraying and increasing ease of application. It also prevents the glass microspheres from agglomerating during the preparation process, resulting in a smooth surface and allowing for a single spray application of a coating thickness of 1-5 mm. The synergistic effect between the raw materials in the coating results in a coating that not only has good thermal insulation performance but also good noise reduction performance and good strength. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of the automotive thermal insulation and noise reduction coating provided in an embodiment of the present invention;

[0012] Figure 2 A diagram showing the surface condition of automotive thermal insulation and noise reduction coatings.

[0013] Figure 3 This is a photo of the inside of the spray bottle after the automotive insulation and noise reduction coating has been applied. Detailed Implementation

[0014] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0015] All terms used in this invention are common terms in the relevant field. Unless otherwise specified, the raw materials, equipment, preparation processes, testing methods, etc., used are all prior art in the relevant field. The hollow microspheres used in the embodiments and comparative examples of this invention are all sourced from Zhengzhou Shenglet Hollow Microsphere New Material Co., Ltd.

[0016] This invention uses hollow microspheres as the main raw material and appropriately increases the amount of thickener, so that the resulting automotive thermal insulation and noise reduction coating not only has the functions of thermal insulation and noise reduction, but also has excellent environmental performance and low cost. Moreover, when using the spraying process, there will be no coating wall sticking caused by the addition of a large number of hollow microspheres, which solves the problem of coating easy to flow when spraying a thickness greater than 2 mm. In the process of spraying automotive thermal insulation and sound insulation coating, a coating thickness of 1-5 mm can be applied in one go.

[0017] Specifically, the first aspect of the present invention provides a vehicle heat insulation and noise reduction coating, the raw materials of which, by weight, include: 150-200 hollow microspheres, 120-140 organic resin, 1-3 preservatives, 8-10 thickeners, 1-2 multifunctional additives, 3-4 film-forming aids, and 300-500 deionized water.

[0018] Hollow microspheres are a key material in thermal insulation and noise reduction coatings. They not only enhance the coating's strength but also serve as a functional material, improving its thermal insulation and noise reduction performance. The lower the density and the larger the particle size of the hollow glass microspheres, the better their thermal insulation and noise reduction performance. Preferably, the hollow microspheres have a density of 0.15-0.30 and a D90 of 85-120 μm. Using too many hollow glass microspheres can result in a thicker coating, making it difficult to disperse evenly and spray. Conversely, using too few microspheres can lead to a thinner coating, causing dripping during vertical spraying. Therefore, the amount of hollow glass microspheres is limited to 150-200 parts by weight, such as 150, 155, 160, 165, 170, 175, 180, 190, 195, or 200 parts.

[0019] In existing coatings, the main function of thickeners is to adjust viscosity, with TT935 being the preferred material. Furthermore, the amount of thickener used in existing coatings is relatively small. However, since this invention is a water-based thermal insulation coating containing a large number of hollow glass microspheres, and these hollow microspheres have a smooth spherical structure, if too little thickener is added, the coating viscosity will be low, leading to rapid stratification. If only a small amount of water is added to adjust the coating consistency, most of the coating will adhere to the inside of the spray bottle during spraying. Therefore, an appropriate amount of thickener is needed to adjust the viscosity. Conversely, if a large amount of thickener is used, the coating viscosity will be high, making the spraying process difficult. Therefore, the amount of thickener added in this invention is controlled at 8-10 parts by weight; preferably, the amount of thickener is 0.9%-1.5% of the total mass of the remaining raw materials in the automotive thermal insulation and noise reduction coating protected by this invention, so that the coating has a certain viscosity, improves the phenomenon of coating adhering to the wall during the spraying process of the fully hollow glass microsphere coating, and the surface of the coating formed after spraying will also become smooth, and a coating with a thickness of 1-5 mm can be sprayed in one go.

[0020] The main function of the organic resin is to form a film, making the coating a unified whole. The preferred material is a styrene-acrylic emulsion or a pure acrylic emulsion. If a large amount of organic resin is used, there will be more thermal bridges after the coating cures, and the coating viscosity will be low, making it prone to sagging during application. If the amount used is too small, the coating cannot form a unified whole with sufficient strength. Therefore, the preferred amount of organic resin is 120-140 parts by weight, such as 120, 125, 130, 135, or 140 parts.

[0021] The main function of the preservative is to prevent the coating from deteriorating during storage and use, and the preferred material is Kathon.

[0022] The main function of the multifunctional additive is to adjust the pH value of the coating system, thereby adjusting the viscosity of the coating system. The preferred material is ANP95.

[0023] The main function of the film-forming aid is to enable the resin in the coating to form a continuous whole, and the preferred material is dodecyl alcohol ester. If the amount of film-forming aid used is too large, it will reduce the water resistance of the coating; if the amount used is too small, the coating will not be able to cure and form a good whole. Therefore, the preferred amount of the film-forming aid is 3-4 parts by weight.

[0024] Water is mainly used as a solvent for coatings. If the amount of water used is too small, the coating will be too thick and difficult to apply. If the amount of water used is too large, the coating will be too thin and prone to dripping. Therefore, the preferred amount of water is 300-500 parts by weight, such as 300, 320, 350, 380, 400, 420, 450, 470, 500 parts, etc.

[0025] To ensure good application performance of the aforementioned automotive thermal insulation and noise reduction coating even at lower temperatures, the raw materials of the coating also include 1-3 parts by weight of antifreeze. The antifreeze is one or a combination of ethylene glycol and propylene glycol.

[0026] The present invention also provides a method for preparing the above-mentioned coating, comprising first mixing organic resin, deionized water, multifunctional additives, film-forming aids and preservatives evenly; then adding hollow microspheres and stirring evenly; and then adding thickener and stirring evenly.

[0027] In the preparation of the above-mentioned coating, the hollow microspheres can be pre-wetted with a non-curing liquid before being mixed with other raw materials to prevent the hollow microspheres from floating during coating preparation due to their light weight. Specifically, a portion of the hollow microspheres can be wetted with deionized water first, and then the remaining deionized water can be mixed evenly with organic resin, multifunctional additives, film-forming aids, and preservatives to form a first mixture; the hollow microspheres pre-wetted with deionized water can be added to the first mixture and mixed evenly to form a second mixture; the thickener can then be added to the second mixture and stirred evenly. An antifreeze agent can also be added to the first mixture.

[0028] A second aspect of the present invention provides a method for applying the above-mentioned coating, wherein the automotive thermal insulation and noise reduction coating is sprayed onto the workpiece to form a thermal insulation and noise reduction coating layer; wherein the thickness of the thermal insulation and noise reduction coating layer in a single spray application is 1-5 mm; to further shorten the spraying process cycle, the thickness of the coating layer in a single spray application is preferably 2-5 mm, such as 2 mm, 3 mm, 4 mm, 5 mm, etc.; more preferably 3-5 mm. The workpiece can be the interior of a vehicle body skin.

[0029] The present invention also provides an application of the above-mentioned coating in automobiles; further, the automotive thermal insulation and noise reduction coating is sprayed onto the interior of the automobile's outer skin to form a thermal insulation and noise reduction coating layer. Specifically, a thermal insulation and noise reduction coating formed by the above-mentioned coating is formed between the automobile interior and the automobile outer skin.

[0030] The above-mentioned technical solutions protected by the present invention will be further illustrated by specific embodiments below.

[0031] Examples 1-3

[0032] Each embodiment of the present invention provides a vehicle thermal insulation and noise reduction coating, the formulation of which is shown in Table 1 below by weight:

[0033] Table 1. Formulations (parts by weight) of automotive thermal insulation and noise reduction coatings provided in each embodiment.

[0034]

[0035] This invention also provides a method for preparing the above-mentioned coating, comprising: first, impregnating hollow microspheres with 100 parts by weight of deionized water; then, mixing the remaining deionized water with the organic resin, multifunctional additive, film-forming aid, and preservative shown in Table 1 to form a first mixture; adding hollow microspheres pre-impregnated with deionized water to the first mixture and mixing evenly to form a second mixture; and finally, adding the thickener to the second mixture and stirring evenly.

[0036] This invention also provides an application of the above-described coating in an automobile. For example... Figure 1 As shown, a thermal insulation and noise reduction coating 3, approximately 3 mm thick, formed from the aforementioned coating, is created between the automotive interior 1 and the automotive exterior 3. This thermal insulation and noise reduction coating is obtained by spraying the aforementioned automotive thermal insulation and noise reduction coating provided in the embodiment onto the interior of the automotive exterior 3.

[0037] Performance testing

[0038] Comparative Example 5 provides a two-component polyurethane insulation material (WANEFOAM RH7003) used in the market.

[0039] The following performance tests were conducted on the coatings provided in the above embodiments and the corresponding comparative examples, and the results are shown in Table 2.

[0040] Coating stability test: After the coatings in Examples 1-3 and Comparative Examples 1-4 were prepared, they were allowed to stand for 30 min and then tested to see if they separated into layers.

[0041] Coating uniformity test: The surface condition of the paste-like coatings in Examples 1-3 and Comparative Examples 1-4 was observed during preparation. The surface conditions of the coatings in Examples 1, 1, 2, and 4 are as follows: Figure 2 As shown;

[0042] Observation of spraying performance: The coatings provided in the examples and comparative examples were sprayed onto the inside of a 30 cm × 30 cm × 30 cm iron box using a real stone paint sprayer, with a thickness of approximately 2 mm. In Comparative Example 4, a 30 cm × 30 cm × 2 mm sample block was made using a 30 cm × 30 cm × 2 mm mold, cured, and then attached to the inside of the iron box (excess material was sanded off during attachment). The insulation material in Comparative Example 5 was mixed evenly at a 1:1 mass ratio, placed within a 30 cm × 30 cm × 2 mm square for free foaming, then sanded into a 30 cm × 30 cm × 2 mm sample block, and attached to the inside of the iron box (excess material was sanded off during attachment). A decibel meter was placed inside the iron box to obtain samples of the coated iron box. The interior of the real stone paint sprayer was observed after the coating was applied. The internal state of the sprayer after application in Examples 1 and Comparative Examples 1 and 2 was as follows: Figure 3 As shown;

[0043] Coating sound insulation performance test: 3 L of water was evenly sprayed from a height of 3 meters onto the iron box sample with the coating formed in the "Spraying Construction Performance Observation" for about 1 hour to simulate the situation when a car is raining, and the average value of the decibel meter was measured.

[0044] Coating thermal insulation performance test: Use an 1100 W bathroom heater to irradiate the iron box sample with the coating formed in the "spraying construction performance observation" at a distance of 0.6 meters for about 1 hour to simulate the situation of a car being exposed to the sun in summer. Use a thermometer to test the internal temperature of the iron box.

[0045] One-time spray thickness test: Use a real stone paint sprayer to spray Examples 1-3 and Comparative Examples 1-3 to a thickness of 5 mm in one go. Use a two-component polyurethane sprayer to spray the material in Comparative Example 5 to a thickness of 5 mm. Observe the appearance of the coating after curing and test its thickness to calculate the average value.

[0046] Environmental performance test: The VOC values ​​of the coatings provided in each embodiment and comparative example were tested respectively.

[0047] Table 2. Results of Coating Performance Tests

[0048]

[0049] As can be seen from Table 2, when preparing thermal insulation and noise reduction coatings using hollow glass microspheres, compared with Example 1, the coatings provided by Comparative Examples 1 and 2 contain less thickener. The prepared coatings show stratification after standing for 30 minutes, indicating poor stability. Moreover, the surface of the coating prepared in Comparative Example 1 is unevenly dispersed, and the microspheres show obvious agglomeration. In addition, during the spraying process of Comparative Examples 1 and 2, the addition of a large amount of hollow microspheres and insufficient thickener leads to excessive stratification during spraying, resulting in a large amount of coating adhering to the wall. Furthermore, the thinner sprayed material causes the coating to flow easily when spraying a layer thicker than 2 mm, as seen in Comparative Examples 1-3. A single layer spraying thickness of 2-5 mm is beneficial for shortening the coating construction cycle and improving the production cycle of coatings such as automotive outer skin. Therefore, the coating provided in this embodiment of the invention improves the problem of glass microspheres easily clumping during the stirring process by adjusting an appropriate amount of thickener. At the same time, it solves the problem of paint sticking to the wall due to excessively rapid layering during spraying caused by the addition of a large number of hollow microspheres, as well as the problem of paint easily flowing when spraying with a thickness greater than 2mm.

[0050] Depend on Figure 2 It can be seen that the surface of Example 1 is relatively fine and uniform compared to the surface of Comparative Example 2. The surface of Comparative Example 1 shows clumping, and the surface of Comparative Example 4 shows lumps. Therefore, the coating provided by the embodiments of the present invention has good dispersibility.

[0051] Depend on Figure 3 It can be seen that: after spraying, Comparative Example 1 had less paint remaining in the spray bottle, while the paints in Comparative Examples 1 and 2 had more paint remaining in the spray bottle after spraying, and the separation interface of the paint was abrupt. Therefore, the amount of thickener in the paint provided in the embodiments of the present invention is 8-10 parts by mass, which makes it less likely to stick to the wall during spraying, and the paint residue in the spray bottle is less, thus reducing paint waste.

[0052] Compared to Example 1, Comparative Example 3 used less hollow glass microspheres, making it prone to dripping during spraying; Comparative Example 4 used more hollow glass microspheres, resulting in a higher viscosity and making it difficult to spray. Therefore, in the embodiments of the present invention, by adjusting the amount of hollow glass microspheres and coordinating them with other raw materials, the coating prepared using low-density hollow glass microspheres exhibits excellent heat insulation and noise reduction effects.

[0053] Compared with Comparative Example 5, the coatings provided in Examples 1-3 have better thermal insulation and noise reduction effects. Therefore, the coatings provided in the embodiments of the present invention have good environmental protection performance and construction performance, as well as good thermal insulation and noise reduction effects, and can achieve the construction of low-thickness coatings during the spraying process of automotive thermal insulation and sound insulation coatings.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A type of automotive thermal insulation and noise reduction coating, comprising, by weight, 160-200 parts hollow microspheres, 120-140 parts organic resin, 1-3 parts preservative, 8-10 parts thickener, 1-2 parts multifunctional additives, 3-4 parts film-forming aids, 1-3 parts antifreeze, and 300-500 parts deionized water; wherein, The hollow microspheres are hollow glass microspheres with a density of 0.15-0.30 and a particle size D90 of 85-120 μm. The organic resin is styrene-acrylic emulsion or pure acrylic emulsion. The amount of thickener is 0.9%-1.5% of the total mass of the remaining raw materials in the automotive thermal insulation and noise reduction coating. The preservative is Kathon. The thickener is TT935. The multifunctional additive is ANP95. The film-forming aid is dodecyl alcohol ester. The antifreeze is one or a combination of ethylene glycol and propylene glycol. The automotive thermal insulation and noise reduction coating is prepared by the following method: first, the hollow microspheres are soaked in a portion of deionized water, and then the remaining deionized water is mixed evenly with the organic resin, multifunctional additive, film-forming aid and preservative to form a first mixture. The antifreeze is added to the first mixture. Hollow microspheres pre-soaked in deionized water are added to the first mixture and mixed evenly to form a second mixture. The thickener is added to the second mixture and stirred evenly.

2. A method for applying the automotive thermal insulation and noise reduction coating as described in claim 1, wherein the automotive thermal insulation and noise reduction coating is sprayed onto the workpiece by a spraying method, and the thickness of the automotive thermal insulation and noise reduction coating in a single spray is 2-5 mm.

3. The construction method according to claim 2, characterized in that, The thickness of the automotive thermal insulation and noise reduction coating in a single spray application is 3-5 mm.

4. The application of the automotive thermal insulation and noise reduction coating as described in claim 1 on automobiles.

5. The application according to claim 4, characterized in that, The automotive thermal insulation and noise reduction coating is sprayed onto the inside of the vehicle's outer skin to form a thermal insulation and noise reduction coating.

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