Environmentally friendly water-based damping coating for vehicles and preparation method thereof

Abstract

The present invention is applicable to the technical field of coating preparation and provides an environmentally friendly water-based damping coating for vehicles and a preparation method thereof. The water-based damping coating comprises the following raw materials in the following percentages: 25-50% emulsion, 0.1-4.5% emulsifier, 0.2-0.8% defoamer, 0.3-3.0% white oil, 0.3-2.0% dispersant, 0.2-5% starch, 61.7-68.6% inorganic filler, and 0.1-0.8% thickener. The present invention successfully constructs an efficient water transfer channel by precisely selecting a non-ionic emulsifier and adding the non-ionic emulsifier to a planetary mixer containing the emulsion for mixing and stirring, ensuring that the moisture of the coating can be quickly and evenly discharged during the baking process, avoiding bubbling and cracking. In addition, the preparation method provided by the present invention simplifies the process flow and reduces production costs, while maintaining the environmental characteristics and excellent performance of the water-based damping coating.

Description

Technical Field

[0001] The invention belongs to the technical field of coating preparation, and in particular relates to an environmentally friendly water-based damping coating for vehicles and a preparation method thereof. Background Art

[0002] Water-based damping coatings are environmentally friendly materials with sound-absorbing, sound-isolating, vibration-reducing, and heat-insulating properties. They are widely used for vibration and noise reduction in vehicles, aircraft, ships, rail transit, household appliances, and various machinery. Their unique ability to directly convert mechanical vibration energy into heat dissipation effectively controls vibration and noise. Compared to traditional asphalt damping coatings, they not only overcome winter fragility and poor environmental performance, but also promote lightweighting of vehicles, offering significant economic and environmental benefits. Vehicle lightweighting is a key factor in modern vehicle manufacturing. On the one hand, lightweighting reduces vehicle weight, conserving raw materials and lowering costs; on the other hand, it reduces traction and braking forces, achieving energy savings and consumption reductions. Lightweighting offers significant and long-term economic benefits.

[0003] However, existing water-based damping coatings still face some challenges in the preparation and application process: such as bubbling and cracking caused by the coating surface drying too quickly during the baking process, and the difficulty in balancing the foaming rate and material strength. To solve these problems, the Chinese patent with publication number CN106700303A solves the bubbling problem of high-temperature coatings by selecting a defoaming agent that strongly reduces the surface tension and adding one or more surfactants to the emulsion system, but the effect does not meet expectations. The amount of surfactant added must be reasonably matched with the amount of defoaming agent, otherwise the expansion rate will be too large, affecting practicality and strength. The Chinese patent with publication number CN106554686A selected different emulsifiers to be added to the water-based damping coating, but did not give the effect of the composite emulsifier and the amount of different emulsifiers on the performance of the damping coating. Chinese patent publication number CN107880654A utilizes the unique molecular structure of a quick-drying emulsion to rapidly release moisture. Thermally conductive fillers are added to adjust the temperature difference between the inside and outside of the coating, controlling the rate of moisture vaporization and escape. The addition of porous fillers facilitates the smooth escape of internal water vapor. However, this formulation is complex and costly. Chinese patent publication number CN109439123B provides an acrylic emulsion for a high-temperature bakeable water-based damping coating. During synthesis, increasing the emulsifier dosage and functional monomers only reduces the size of the latex particles, leaving no amphiphilic emulsifier remaining to effectively provide channels for water vapor evaporation. Consequently, an environmentally friendly water-based damping coating for vehicles and its preparation method are proposed. Summary of the Invention

[0004] The purpose of the present invention is to provide an environmentally friendly water-based damping coating for vehicles and a preparation method thereof, aiming to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An environmentally friendly water-based damping coating for vehicles, comprising the following raw materials in the following percentages:

[0007] Emulsion 25-50%, emulsifier 0.1-4.5%, defoamer 0.2-0.8%, white oil 0.3-3.0%, dispersant 0.3-2.0%, starch 0.2-5%, inorganic filler 61.7-68.6%, thickener 0.1-0.8%.

[0008] Furthermore, the emulsifier is a nonionic emulsifier, and the nonionic emulsifier includes disodium salt of alkylphenol polyoxyethylene ether sulfosuccinate monoester, aliphatic polyoxyethylene ether, fatty acid polyoxyethylene ether, alkylphenol polyoxyethylene ether, and fatty polyoxyethylene alcohol.

[0009] Furthermore, the emulsion is a mixture of one or more of an acrylic copolymer with a glass transition temperature of 0°C, a styrene-acrylic emulsion with a glass transition temperature of 20°C, and a styrene-butadiene emulsion with a glass transition temperature of 20°C.

[0010] Furthermore, the defoaming agent is an oligomer with surface activity.

[0011] Furthermore, the closed cup flash point of the white oil is 140-160°C.

[0012] Furthermore, the starch is corn starch or sweet potato starch.

[0013] Furthermore, the inorganic filler is formed by mixing any two or more of mica 10-20%, wollastonite 5-30%, heavy calcium powder 10-25% and talc 10-25%.

[0014] Furthermore, the thickener is a polyurethane thickener.

[0015] A method for preparing the above-mentioned environmentally friendly water-based damping coating for vehicles comprises the following steps:

[0016] Add emulsion, emulsifier and white oil to the planetary mixer at the same time and stir for 10 minutes until a uniform slurry is formed; then add dispersant and defoamer and stir for 10 minutes; finally, add inorganic filler and starch to the slurry and stir for 20 minutes until a uniform slurry is formed; then add thickener to the slurry and stir for 10 minutes to obtain a paste coating.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention has made a significant breakthrough in solving the problems of bubbling and cracking of the coating during the baking process. By accurately selecting non-ionic emulsifiers and adding the non-ionic emulsifiers to a planetary mixer containing an emulsion for mixing and stirring, the present invention successfully constructs an efficient water delivery channel to ensure that the moisture of the coating can be quickly and evenly discharged during the baking process, thereby avoiding bubbling and cracking, and significantly improving the quality and appearance of the coating. In addition, the preparation method provided by the present invention simplifies the process flow and reduces production costs, while maintaining the environmental characteristics and excellent performance of water-based damping coatings, providing a more reliable and economical solution for vibration reduction and noise reduction in vehicles, aircraft, ships and other fields. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0021] During the production process of high-build coatings, various emulsions and fillers are added and thoroughly stirred. At this point, the system is extremely chaotic and the various materials are in a state of very high potential energy. During high-temperature baking, water vapor has many channels for evaporation, such as gaps between raw materials and cracks in the foaming agent, which can allow water vapor to evaporate. Even without adding any other materials such as surfactants and defoamers, the coating surface will not produce bubbles or cracks. However, after the coating is left to stand, bulging will appear after applying the sample. At this time, the system's chaos is reduced, the potential energy is also reduced, and the surface tension is increased. Without the addition of emulsifiers, there are no channels formed by hydrophilic groups to reduce surface tension, and water vapor has no evaporation channels, which will naturally cause bubbles.

[0022] The method and amount of emulsifier added during the production of coatings have a certain impact on the coating. Coatings are very selective for the type of emulsifier. Therefore, the present invention tests two types of emulsifiers, anionic and nonionic, and also tests the mixed addition amount of the two types of emulsifiers and the different emulsifier dosages to compare the effects on coating performance.

[0023] Example 1: 33 parts of emulsion, 1 part of alkylphenol polyoxyethylene ether sulfosuccinate monoester disodium salt (emulsifier), and 0.9 part of white oil were added to a planetary mixer and stirred for 10 minutes. 1.1 parts of dispersant and 0.2 parts of defoamer were then added and stirred for an additional 10 minutes. Powders of calcium carbonate (21.7 parts), mica (20 parts), wollastonite (20 parts), and starch (2 parts) were added and stirred for a further 20 minutes. 0.1 part of thickener was added and stirred for a further 10 minutes to obtain a paste coating. The sample was then applied to a sample plate to a thickness of 3 mm and baked in a 140°C oven for 30 minutes.

[0024] Example 2: The operation is the same as that of Example 1, except that 1 part of alkylphenol polyoxyethylene ether sulfosuccinate monoester disodium salt in Example 1 is replaced with 1 part of alkylphenol polyoxyethylene ether, and the rest remains unchanged.

[0025] Example 3: The operation is the same as that of Example 1, except that 1 part of disodium salt of alkylphenol polyoxyethylene ether sulfosuccinate monoester in Example 1 is replaced with 1 part of sodium dodecylbenzene sulfate, and the rest remains unchanged.

[0026] Example 4: The operation is the same as that of Example 1, except that 1 part of disodium salt of alkylphenol polyoxyethylene ether sulfosuccinate monoester in Example 1 is replaced with 1 part of sodium dodecylbenzenesulfonate, and the rest remains unchanged.

[0027] The sample results obtained in Examples 1 to 4 are shown in Table 1:

[0028] Table 1 Measured results of coatings obtained after adding different types of emulsifiers

[0029]

[0030] Table 1 shows that after the addition of nonionic surfactants, the coating surface is smooth and free of bubbles. However, after the addition of anionic surfactants, a good water transport channel for water vapor to evaporate is not formed within the system, resulting in blistering of the coating. Therefore, when the anionic and nonionic surfactants are added in the same amount, the nonionic surfactant has a better bubble control effect, while the anionic surfactant has no effect.

[0031] Example 5: 30 parts of emulsion (no emulsifier) ​​and 0.9 parts of white oil were added to a planetary mixer and stirred for 10 minutes. 1.0 parts of dispersant was then added and stirred for an additional 10 minutes. Powders of calcium carbonate (21.8 parts), mica (20 parts), talc (15 parts), wollastonite (10 parts), and starch (1 part) were added and stirred for a further 20 minutes. 0.3 parts of thickener was added and stirred for a further 10 minutes to obtain a paste. The sample was then applied to a sample plate to a thickness of 3 mm and baked in a 140°C oven for 30 minutes.

[0032] Example 6: 0.5 parts each of the emulsifiers alkylphenol polyoxyethylene ether sulfosuccinate monoester disodium salt and sodium dodecylbenzene sulfate, 20.8 parts of heavy calcium powder, and the amounts and order of addition of other raw materials are the same as in Example 5.

[0033] Example 7: 1.4 parts each of the emulsifiers alkylphenol polyoxyethylene ether sulfosuccinate monoester disodium salt and sodium lauryl sulfate, 19 parts of heavy calcium powder, and the amounts and order of addition of other raw materials are the same as in Example 5.

[0034] Example 8: 2.25 parts each of the emulsifiers alkylphenol polyoxyethylene ether sulfosuccinate monoester disodium salt and sodium lauryl sulfate, 17.3 parts of heavy calcium powder, and the amounts and order of addition of other raw materials are the same as in Example 5.

[0035] The sample results obtained in Examples 5 to 8 are shown in Table 2:

[0036] Table 2 Measured results of the coating obtained after adding the mixed emulsifier

[0037]

[0038] Table 2 shows that samples without emulsifiers showed no noticeable bubbles when scraped and baked immediately after production. However, bubbles appeared when scraped and baked the next day. Even after the anionic and nonionic emulsifiers were mixed and added to the system, small bubbles still appeared on the coating surface. This is because the anionic emulsifier failed to form a water transport channel, resulting in blistering on the coating surface.

[0039] Example 9: 30 parts of emulsion, 0.5 parts of disodium alkylphenol polyoxyethylene ether sulfosuccinate, and 0.9 parts of white oil were added to a planetary mixer and stirred for 10 minutes. 1.0 parts of dispersant was also added and stirred for 10 minutes. Then, 21.3 parts of calcium carbonate powder, 20 parts of mica, 15 parts of talc, 10 parts of wollastonite, and 1 part of starch were added and stirred for a further 20 minutes. 0.3 parts of thickener was added and stirred for a further 10 minutes to obtain a paste coating. The sample was then applied to a test panel to a thickness of 3 mm and baked in a 140°C oven for 30 minutes.

[0040] Example 10: The operation is the same as that in Example 9, except that the amount of the emulsifier alkylphenol polyoxyethylene ether sulfosuccinate monoester disodium salt is changed to 1.5 parts, and the amount of the powder heavy calcium is changed to 20.3 parts, and the other parts remain unchanged.

[0041] Example 11: The operation is the same as that in Example 9, except that the amount of the emulsifier alkylphenol polyoxyethylene ether sulfosuccinate monoester disodium salt is changed to 2.5 parts, and the amount of the powder heavy calcium is changed to 19.3 parts, and the other parts remain unchanged.

[0042] The sample results obtained in Examples 9 to 11 are shown in Table 3:

[0043] Table 3 Measured results of the coatings obtained after adding different amounts of nonionic emulsifiers

[0044] Corresponding samples Amount of alkylphenol polyoxyethylene ether sulfosuccinate monoester disodium salt added (parts) Phenomenon Example 9 0.5 Smooth surface without bubbles Example 10 1.5 Smooth surface without bubbles Example 11 2.5 Smooth surface without bubbles

[0045] It can be seen from Table 3 that no bubbles appeared after adding different amounts of non-ionic emulsifier to make samples, and the sample surface was smooth.

[0046] Example 12: 28 parts of emulsion, 0.5 parts of sodium dodecylbenzene sulfate (emulsifier), and 0.9 parts of white oil were added to a planetary mixer and stirred for 10 minutes. 1.0 parts of dispersant was then added and stirred for another 10 minutes. 21.3 parts of calcium carbonate powder, 22 parts of mica, 25 parts of talc, and 1 part of starch were added and stirred for a further 20 minutes. 0.3 parts of thickener was added and stirred for a further 10 minutes to obtain a paste coating. The sample was then applied to a sample plate to a thickness of 3 mm and baked in a 140°C oven for 30 minutes.

[0047] Example 13: The operation is the same as that in Example 12, except that the amount of the emulsifier sodium dodecylbenzene sulfate is changed to 1.5 parts and the powdered calcium carbonate is changed to 20.3 parts. Other changes remain unchanged.

[0048] Example 14: The operation is the same as that in Example 12, except that the amount of the emulsifier sodium lauryl sulfate is changed to 2.5 parts and the powdered calcium carbonate is changed to 19.3 parts. Other changes remain unchanged.

[0049] The sample results obtained in Examples 12 to 14 are shown in Table 4:

[0050] Table 4 Measured results of the coatings obtained after adding different amounts of anionic emulsifiers

[0051] Corresponding samples Amount of sodium lauryl sulfate added (parts) Phenomenon Example 12 0.5 Small bubbles appear on the surface Example 13 1.5 There are bubbles on the surface Example 14 2.5 There are bubbles on the surface

[0052] As can be seen from Table 4, bubbles appeared after samples were prepared by adding different amounts of anionic emulsifiers, indicating that the system used in the present invention is not suitable for adding anionic emulsifiers.

[0053] In summary, the present invention has experimentally found that nonionic emulsifiers can effectively disperse the emulsion and surround it on the surface of latex particles to form water channels, making the product surface smooth and bubble-free. The addition of anionic surfactants has a poor effect, and the water in the coating is not discharged in time, resulting in the formation of bubbles.

[0054] The invention adopts the method of firstly putting emulsion, nonionic emulsifier and white oil into a planetary mixer for mixing, then adding various liquid raw materials, and finally adding powder, and obtaining the water-based damping coating after fully stirring.

[0055] The present invention has achieved a significant breakthrough in solving the problems of bubbling and cracking of the coating during the baking process. By carefully selecting non-ionic emulsifiers, the present invention successfully constructs an efficient water transfer channel, ensuring that the water in the coating can be quickly and evenly discharged during the baking process, thereby avoiding bubbling and cracking, and significantly improving the quality and appearance of the coating. In addition, the preparation method provided by the present invention simplifies the process flow and reduces production costs, while maintaining the environmental characteristics and excellent performance of water-based damping coatings, providing a more reliable and economical solution for vibration and noise reduction in vehicles, aircraft, ships and other fields.

[0056] In addition, the present invention conducted the following experiments:

[0057] 1) Test purpose: To test the performance of the coating obtained in Example 10, with the curing conditions being 140° C. and 30 min.

[0058] 2) Test items: appearance, density (before and after curing), non-volatile matter content, pressure flow viscosity, appearance after curing, fluidity, adhesion (room temperature, after heat resistance, after moisture resistance, after hot and cold cycling resistance, after cold resistance, after over-baking resistance, after salt spray resistance), storage stability (appearance, pressure flow viscosity change rate), ash content, loss factor, odor, volatile organic compounds, combustion characteristics, expansion rate (thickness direction).

[0059] 3) Test results, see Table 5:

[0060] Table 5 Test results

[0061]

[0062]

[0063] It can be seen from the results in Table 5 that the test results of appearance, density (before and after curing), non-volatile matter content, pressure flow viscosity, appearance after curing, fluidity, adhesion (room temperature, after heat resistance, after moisture resistance, after hot and cold cycling resistance, after cold resistance, after overbaking resistance, after salt spray resistance), storage stability (appearance, pressure flow viscosity change rate), ash content, loss factor, odor, volatile organic matter, combustion characteristics, and expansion rate (thickness direction) of the samples submitted meet the requirements.

[0064] The above are only preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several variations and improvements can be made without departing from the concept of the present invention. These should also be regarded as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. An environmentally friendly water-based damping coating for vehicles, characterized in that: Includes the following percentages of ingredients: Emulsion 25~50%, emulsifier 0.1~4.5%, defoamer 0.2~0.8%, white oil 0.3~3.0%, dispersant 0.3~2.0%, starch 0.2~5%, inorganic filler 61.7~68.6%, thickener 0.1~0.8%; The emulsifier is alkylphenol polyoxyethylene ether sulfosuccinate monoester disodium salt; The emulsion is a mixture of one or more of an acrylic copolymer with a glass transition temperature of 0°C, a styrene-acrylic emulsion with a glass transition temperature of 20°C, and a styrene-butadiene emulsion with a glass transition temperature of 20°C; The inorganic filler is prepared by mixing any two or more of the following raw materials: 10-20% mica, 5-30% wollastonite, 10-25% heavy calcium powder, and 10-25% talc.

2. The environmentally friendly water-based damping coating for vehicles according to claim 1, characterized in that: The defoaming agent is an oligomer with surface activity.

3. The environmentally friendly water-based damping coating for vehicles according to claim 1, characterized in that: The closed cup flash point of the white oil is 140-160°C.

4. The environmentally friendly water-based damping coating for vehicles according to claim 1, characterized in that: The starch is corn starch or sweet potato starch.

5. The environmentally friendly water-based damping coating for vehicles according to claim 1, characterized in that: The thickener is a polyurethane thickener.

6. A method for preparing the environmentally friendly water-based damping coating for vehicles according to any one of claims 1 to 5, characterized in that: The following steps are involved: Add emulsion, emulsifier and white oil to the planetary mixer at the same time and stir for 10 minutes until a uniform slurry is formed; then add dispersant and defoamer and stir for 10 minutes; finally, add inorganic filler and starch to the slurry and stir for 20 minutes until a uniform slurry is formed; then add thickener to the slurry and stir for 10 minutes to obtain a paste coating.

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