Two-component elastic feel topcoat for abs substrate and its preparation method

Abstract

The application relates to the technical field of elastic topcoats, and particularly discloses a two-component elastic hand feeling topcoat for ABS substrates and a preparation method thereof. The two-component elastic hand feeling topcoat for ABS substrates comprises an A component and a B component, the A component comprises a modified emulsion and a filler, the B component comprises a solvent and a crosslinking agent, and the preparation raw material of the modified emulsion comprises an acrylate emulsion, tannin and a metal cation salt. The preparation method of the two-component elastic hand feeling topcoat comprises the following steps: S1, mixing the modified emulsion and the filler to obtain the A component, and mixing the solvent and the crosslinking agent to obtain the B component; and S2, mixing the A component and the B component. The two-component elastic hand feeling topcoat for ABS substrates has the advantages that the surface microcracks of the ABS substrate can be repaired, the low-temperature flexibility is good, and the topcoat is not prone to brittle cracking at low temperature. In addition, the preparation method has the advantages of fewer process steps and simplicity and high efficiency.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of elastic topcoats, and more particularly to a two-component elastic touch topcoat for ABS substrates and a preparation method thereof. BACKGROUND

[0002] The elastic touch topcoat is made of a highly elastic synthetic resin emulsion, the macromolecules of the resin are highly coiled, and the intermolecular force is weak, so that the resin is easily deformed under external force, and the deformation disappears after the external force is removed, so that the elastic touch topcoat exhibits elasticity. After the elastic touch topcoat is coated and solidified on the surface of a substrate, a uniform, continuous and tough protective film with elasticity is formed, which can compensate for and cover small cracks on the surface of the substrate.

[0003] Currently, there is a two-component topcoat which comprises an A component composed of a water-based acrylic emulsion, titanium white, a defoaming agent, a leveling agent, deionized water, a dispersing agent, a low-foam wetting agent and a solvent, and a B component composed of a solvent and a hydrophilic diisocyanate, wherein the acrylic emulsion imparts a certain elasticity to the paint film.

[0004] With the further development and application of coatings in the industry, people's requirements for the performance of coatings have improved. The film-forming property and elasticity of the acrylic emulsion are relatively good, but due to the lack of crosslinking points on the linear molecules thereof, it is difficult to form a three-dimensional network crosslinking state, which leads to the brittleness of the adhesive film at low temperature, reduces the low-temperature flexibility of the coating, and thus affects the performance of repairing cracks at low temperature. SUMMARY

[0005] In order to improve the low-temperature flexibility of the coating and reduce the problem of brittle cracking of the topcoat at low temperature, the application provides a two-component elastic touch topcoat for ABS substrates and a preparation method thereof.

[0006] In a first aspect, the application provides a two-component elastic touch topcoat for ABS substrates, which adopts the following technical solution:

[0007] A two-component elastic touch topcoat for ABS substrates comprises an A component and a B component, the A component comprises a modified emulsion and a filler, and the B component comprises a solvent and a crosslinking agent.

[0008] The preparation raw materials of the modified emulsion include an acrylic emulsion, tannin and a metal cation salt.

[0009] By adopting the technical scheme, when the water-based acrylic emulsion is used in the topcoat, the topcoat prepared has cracks in the interval of-40℃ to 0℃, and when the modified emulsion is used, the topcoat prepared has cracks at-49℃, which indicates that the low-temperature performance of the topcoat is improved by using the modified emulsion prepared in the application, so that the topcoat has a cracking phenomenon at a lower temperature. The reason may be that:

[0010] The acrylic emulsion has certain elasticity after curing due to its own characteristics; after the tannin and the metal cation salt react, the complex formed wraps the latex particles in the emulsion, thereby increasing the steric hindrance effect between the topcoat molecules and reducing the crystallinity, so as to improve the low-temperature performance. In summary, the combination of the three is beneficial to improve the low-temperature flexibility of the topcoat and reduce the cracking of the topcoat at low temperature.

[0011] Optionally, the acrylic emulsion is a silicone-modified acrylic emulsion.

[0012] By adopting the technical scheme, the silicone can improve the brittleness of the acrylic emulsion at low temperature, so that the silicone-modified acrylic emulsion is used as the film-forming matrix, and the tannin and the metal cation are combined to make the modified emulsion have better low-temperature performance and improve the low-temperature elongation rate of the paint film.

[0013] Optionally, in the modified emulsion, the weight ratio of the tannin to the silicone-modified acrylic emulsion is (0.18-0.22):10.

[0014] By adopting the technical scheme, when the amount of tannin is in the above range, the amount of the complex formed is appropriate, the wrapping effect on the surface of the latex particles is good, and the low-temperature performance of the coating is improved.

[0015] Through detection, when the weight ratio of the tannin to the silicone-modified acrylic emulsion is 0.1:10, the temperature at which the topcoat cracks is-52℃, and when the weight ratio of the tannin to the silicone-modified acrylic emulsion is in the range of (0.18-0.22):10, the temperature at which the topcoat cracks is-54℃, and the topcoat is not easy to crack at low temperature.

[0016] Optionally, in the modified emulsion, the weight ratio of the metal cation salt to the silicone-modified acrylic emulsion is (0.15-0.20):10.

[0017] By adopting the technical scheme, when the amount of the metal cation salt is in the above range, the amount of the complex formed with the tannin is appropriate, the wrapping effect on the latex particles is better, the low-temperature flexibility of the coating is improved, and the temperature at which cracks appear is further reduced.

[0018] When the weight ratio of the tannin and the silicone-modified acrylate emulsion is 0.1:10, the temperature at which the topcoat appears to be cracked is -52℃, and when the weight ratio of the tannin and the silicone-modified acrylate emulsion is in the range of (0.15-0.20):10, the temperature at which the topcoat appears to be cracked is -56℃, and the topcoat is not easy to be cracked at low temperature.

[0019] Optionally, the metal cation salt is one of ferric chloride, aluminum chloride, zirconium chloride, and zinc chloride.

[0020] By adopting the technical scheme, the metal cation salt can be selected from the above range, the topcoat prepared has better low-temperature flexibility, and the elongation at break is more than 827%, and the topcoat has better crack repairing effect on the base material.

[0021] Optionally, the preparation raw material of the modified emulsion further comprises a polyether type polyurethane prepolymer.

[0022] By adopting the technical scheme, it is detected that when the polyether type polyurethane prepolymer is not added in the modified emulsion, the temperature at which the topcoat appears to be cracked is -56℃ at the lowest, and when the polyether type polyurethane prepolymer is added in the modified emulsion, the temperature at which the topcoat appears to be cracked is further reduced to -58℃, and the low-temperature flexibility of the topcoat is better. The reason is that the ether group is easy to rotate, and the polyether type polyurethane has superior low-temperature flexibility. The compounding of the polyether type polyurethane and the silicone-modified acrylate emulsion makes the modified emulsion better improve the low-temperature flexibility of the topcoat and reduce the cracking phenomenon.

[0023] And the elongation at break is increased from 977% to 991% by adding the polyether type polyurethane prepolymer, and the performance of the topcoat is better.

[0024] Optionally, the weight ratio of the polyether type polyurethane prepolymer and the silicone-modified acrylate emulsion is (0.3-0.6):1.

[0025] By adopting the technical scheme, when the addition amount of the polyether type polyurethane prepolymer is in the above range, the ratio of the polyether type polyurethane prepolymer and the silicone-modified acrylate emulsion is appropriate, and the two are complementary to each other to improve the low-temperature flexibility of the topcoat.

[0026] It is detected that when the weight ratio of the polyether type polyurethane prepolymer and the silicone-modified acrylate emulsion is 0.25:1, the temperature at which the topcoat appears to be cracked is -58℃, and when the weight ratio of the polyether type polyurethane prepolymer and the silicone-modified acrylate emulsion is in the range of (0.3-0.6):1, the temperature at which the topcoat appears to be cracked is -60℃, and the topcoat is not easy to be cracked at low temperature.

[0027] Optionally, the weight ratio of the A component and the B component is (2-4):1.

[0028] The A component comprises the following components in parts by weight: modified emulsion 50-60 parts, filler 20-25 parts; the B component comprises the following components in parts by weight: solvent 30-40 parts, crosslinking agent 60-70 parts.

[0029] By adopting the technical scheme, the prepared finish paint is composed of the A component containing the modified emulsion and the B component, when the ratio of the A component to the B component and the amount of each component are within the above range, the prepared finish paint has relatively optimal adhesion and other performances, meets the use requirement, and has high flexibility at low temperature, and the finish paint is not prone to be brittle and cracked at low temperature.

[0030] In a second aspect, the application provides a preparation method of a two-component elastic touch finish paint for ABS substrate, which adopts the following technical scheme:

[0031] The preparation method of the two-component elastic touch finish paint for ABS substrate comprises the following steps:

[0032] S1, mixing a modified emulsion and a filler to obtain an A component; mixing a solvent and a crosslinking agent to obtain a B component;

[0033] S2, mixing the A component and the B component.

[0034] By adopting the technical scheme, the steps are less, the overall process is simple and efficient, which is beneficial to the industrialized scale-up preparation of the finish paint, and the adhesion and other performances of the prepared finish paint meet the use requirement, and the finish paint has good flexibility at low temperature, and the low-temperature brittle cracking problem of the current acrylic base paint is improved.

[0035] In summary, the application has the following beneficial effects:

[0036] 1. In the application, tannin and metal cation salt are added to the modified emulsion, the complex formed by the two wraps the latex particles in the acrylic emulsion, increases the steric hindrance between molecules, and reduces the crystallinity, thereby improving the low-temperature flexibility of the finish paint and improving the brittle cracking problem of the finish paint prepared from the acrylic emulsion at low temperature;

[0037] 2. In the application, the organic silicon-modified acrylic emulsion is preferably used, because the organic silicon can improve the low-temperature performance of the acrylic ester and reduce the low-temperature brittleness, and the finish paint prepared from the organic silicon-modified acrylic emulsion as the base material has better low-temperature flexibility and is not prone to brittle cracking at low temperature;

[0038] 3. In the application, the polyether type polyurethane prepolymer is further added to the modified emulsion, because the ether group is easy to rotate, which endows the polyether type polyurethane with superior low-temperature flexibility, and the compounding of the polyether type polyurethane with the organic silicon-modified acrylic emulsion can further improve the low-temperature flexibility of the finish paint and reduce the brittle cracking of the finish paint at low temperature. DETAILED DESCRIPTION

[0039] The application is further described in detail below in conjunction with the examples.

[0040] Preparation Example 1

[0041] A modified emulsion, the components and their usage amounts are shown in Table 1, is prepared by the following steps:

[0042] Add tannin and metal cation salt into the acrylate emulsion, and stir and mix for 1 h, to obtain.

[0043]

The acrylate emulsion is an aqueous acrylate emulsion, which is from Xinde Chemical Co., Ltd. in Yingde City, with model number 1022; and the metal cation salt in this example is ferric chloride.

[0044] Preparation Example 2

[0045] A modified emulsion, which is different from Example 1 in that an equal amount of silicone-modified acrylate emulsion is used instead of the aqueous acrylate emulsion.

[0046] Preparation Examples 3-8

[0047] A modified emulsion, which is different from Example 2 in that the usage amounts of the components are shown in Table 1.

[0048] Comparative Preparation Examples 1-2

[0049] A modified emulsion, which is different from Example 2 in that the usage amounts of the components are shown in Table 1.

[0050] Table 1: Components and their weights (kg) in Preparation Examples 1-8 and Comparative Preparation Examples 1-2

[0051]

[0052] Preparation Examples 9-10

[0053] A modified emulsion, which is different from Preparation Example 2 in that the usage of the metal cation salt is different, specifically as follows:

[0054] Preparation Example 2, the metal cation salt is ferric chloride.

[0055] Preparation Example 9, an equal amount of aluminum chloride is used instead of ferric chloride.

[0056] Preparation Example 10, an equal amount of zirconium chloride is used instead of ferric chloride.

[0057] Preparation Examples 11-14

[0058] A modified emulsion, which is different from Example 7 in that polyether polyurethane prepolymer is also added during the process of adding tannin and metal cation salt into the acrylate emulsion.

[0059] The amount of the polyether polyurethane prepolymer added is as follows:

[0060] Preparation Example 11, the weight ratio of the amount of the polyether polyurethane prepolymer added to the silicone-modified acrylate emulsion is 0.25:1.

[0061] Preparation Example 12, the weight ratio of the amount of the polyether polyurethane prepolymer added to the silicone-modified acrylate emulsion is 0.3:1.

[0062] Preparation Example 13, the weight ratio of the amount of the polyether polyurethane prepolymer added to the silicone-modified acrylate emulsion is 0.45:1.

[0063] Preparation Example 14, the weight ratio of the amount of the polyether polyurethane prepolymer added to the silicone-modified acrylate emulsion is 0.6:1.

[0064]

The polyether polyurethane prepolymer is from Zibo Zhuo Yue Science and Technology Development Co., Ltd., model T80.

[0065] Examples 1-4

[0066] A two-component elastic feel topcoat for ABS substrates is prepared by the following steps:

[0067] S1, the modified emulsion (prepared by Preparation Example 1), filler (titanium dioxide), tegO830, BYK381, water, BYK190, are mixed at 25°C under stirring for 20 min to obtain component A; the solvent (propylene glycol diacetate), crosslinking agent (Bayhydur XP 2655) are mixed at 25°C under stirring for 30 min to obtain component B; wherein the components in each of components A and B and their respective weights are shown in Table 2;

[0068] S2, component A and component B are mixed in a weight ratio of 2:1 for 20 min to obtain the product.

[0069] Table 2-1 Components and their weights (kg) in component A in Examples 1-4

[0070]

[0071]

[0072] Table 2-2 Components and their weights (kg) in component B in Examples 1-4

[0073]

[0074] Comparative Example 1

[0075] A topcoat, which differs from Example 1 in that an equal amount of water-based acrylic emulsion is used instead of the modified emulsion.

[0076] The water-based acrylic emulsion is obtained from Xindeliang Chemical Co., Ltd., model 1022.

[0077] Examples 5-6

[0078] A two-component elastic touch topcoat for ABS substrates, which differs from Example 1 in that the weight ratio of the A component to the B component is different, as follows:

[0079] Example 1, the weight ratio of the A component to the B component is 2:1.

[0080] Example 5, the weight ratio of the A component to the B component is 3:1.

[0081] Example 6, the weight ratio of the A component to the B component is 4:1.

[0082] Examples 7-19, Comparative Examples 2-3

[0083] A two-component elastic touch topcoat for ABS substrates, which differs from Example 3 in that the use of the modified emulsion is as shown in Table 3, but the amount of the modified emulsion used in the topcoat is unchanged.

[0084] Table 3 Use of modified emulsion in Examples 5, 7-19, and Comparative Examples 2-3

[0085] Example 5 7 8 9 10 11 12 13 14 15 16 17 18 19 Preparation Example of Modified Emulsion 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Comparative Example 2 3 \ \ \ \ \ \ \ \ \ \ \ \ Comparative Preparation Example of Modified Emulsion 1 2 \ \ \ \ \ \ \ \ \ \ \ \

[0086] Performance testing

[0087] The topcoats prepared in the examples and comparative examples were tested for the following properties, and the test results are shown in Table 4.

[0088] Test methods

[0089] 1. Low-temperature flexibility, tested according to GB / T 16777-2008, with a test bar diameter of 10 mm, and test temperatures of -40°C, -45°C, -47°C, -49°C, -50°C, -52°C, -54°C, -56°C, -58°C, and -60°C, respectively. The temperature at which cracks or fractures appear on the surface of the test sample was recorded. The lower the temperature, the better the low-temperature flexibility of the topcoat, and the less likely the topcoat is to crack at low temperatures.

[0090] 2. Elongation at break, tested according to GB / T 16777-2008.

[0091] Table 4 Performance test results

[0092] Item Temperature at which cracking, breaking occurs (°C) Breaking elongation (%) Example 1 -49 837 Example 2 -50 855 Example 3 -50 861 Example 4 -50 853 Example 5 -52 876 Example 6 -50 872 Example 7 -52 894 Example 8 -52 911 Example 9 -54 935 Example 10 -54 928 Example 11 -54 942 Example 12 -56 977 Example 13 -56 963 Example 14 -56 974 Example 15 -56 972 Example 16 -58 991 Example 17 -60 1013 Example 18 -60 1035 Example 19 -60 1028 Comparative Example 1 -40 760 Comparative Example 2 -40 826 Comparative Example 3 -40 803

[0093] As can be seen from Table 4, the modified emulsion prepared in Preparation Example is used in Example 1, the prepared finish film cracks at -49℃, and the elongation at break is as high as 837%; in Comparative Example 1, because the equal amount of water-based acrylic emulsion is used instead of the modified emulsion, the prepared finish film cracks in the range of -40℃ to 0℃, and the elongation at break is 760%. It is shown that the low-temperature flexibility of the finish film can be improved by adding the modified emulsion, the brittle cracking at low temperature is reduced, the elasticity of the finish film is better, the crack is better covered, and the use needs are met.

[0094] The reason for the analysis may be that the acrylic emulsion has a certain elasticity, which can make up for the crack; the complex of tannin and metal cation wraps the latex particles, thereby increasing the steric hindrance effect between the film molecules, reducing the crystallinity, improving the low-temperature performance, and making the finish film crack at a lower temperature.

[0095] Comparative Examples 2-3 and Example 3 differ in that the modified emulsion lacks tannin or metal cation salt, the finish film cracks in the range of -40℃ to 0℃, and the elongation at break decreases to different degrees compared with Example 3, indicating that adding only one of the two does not improve or even reduces the performance of the finish film.

[0096] Examples 2-4 and Example 1 differ in the use amount of each component. As can be seen from Table 4, the performance of the finish film in Examples 2-4 is better, and the use amount of each component should be within the range of Examples 2-4.

[0097] Examples 5-6 and Example 1 differ in the weight ratio of A component to B component. When the use amount of A component and B component is within the range of Examples 1, 5 and 6, the performance of the finish film is better.

[0098] Example 7 and Example 5 differ in that equal amount of silicone-modified acrylic emulsion is used instead of water-based acrylic emulsion in the modified emulsion, not only the cracking temperature is further reduced from -50℃ to -52℃, the low-temperature flexibility of the finish film is better, and the elongation at break is also improved, and the crack sealing performance of the finish film is better.

[0099] Examples 8-10 and Example 7 differ in the addition amount of tannin, and the cracking temperature of the finish film gradually decreases from -52℃ to -54℃; Examples 11-13 and Example 9 differ in the addition amount of metal cation salt, and the cracking temperature of the finish film gradually decreases from -54℃ to -56℃; it is shown that when the use amount of tannin and metal cation salt is within the range of Examples 8-13, the low-temperature flexibility of the prepared finish film is better, and the finish film is not easy to crack at low temperature.

[0100] The difference between the embodiments 14-15 and the embodiment 12 is that the metal cation salt is used differently, and the performance of the topcoat is better. It should be noted that in the present application, the metal cation salt can be selected from ferric chloride, aluminum chloride, zirconium chloride and zinc chloride, and does not have a great influence on the performance of the topcoat. In the present application, only ferric chloride, aluminum chloride and zirconium chloride are briefly introduced.

[0101] The difference between the embodiments 16-19 and the embodiment 12 is that the polyether polyurethane prepolymer is added in the preparation process of the modified emulsion. The temperature at which the topcoat appears to be cracked is reduced from -56℃ to -60~-58℃, indicating that the addition of the polyether polyurethane prepolymer further enhances the low-temperature flexibility of the topcoat, making the topcoat less likely to be cracked;

[0102] The reason for this may be that the polyether polyurethane prepolymer has excellent low-temperature flexibility after polymerization, and the compounding of the polyether polyurethane prepolymer, the silicone-modified acrylate emulsion, the tannin and the metal cation salt makes the topcoat have better low-temperature flexibility, improving the brittle cracking problem of the topcoat at low temperature.

[0103] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A two-component elastic feel topcoat for ABS substrates, characterized in that, The A component comprises modified emulsion and filler; the B component comprises solvent and crosslinking agent; The raw material of the modified emulsion comprises acrylate emulsion, tannin, metal cation salt and polyether type polyurethane prepolymer; The acrylate emulsion is silicone modified acrylate emulsion; In the modified emulsion, the weight ratio of tannin to silicone modified acrylate emulsion is (0.18-0.22):10; In the modified emulsion, the weight ratio of metal cation salt to silicone modified acrylate emulsion is (0.15-0.20):10; The weight ratio of the adding amount of the polyether type polyurethane prepolymer to silicone modified acrylate emulsion is (0.3-0.6):1; The weight ratio of the A component to the B component is (2-4):1; The A component comprises the following components in weight fraction: modified emulsion 50-60 parts, filler 20-25 parts; the B component comprises the following components in weight fraction: solvent 30-40 parts, crosslinking agent 60-70 parts.

2. A two-component elastic feel topcoat for ABS substrates according to claim 1, characterized in that: The metal cation salt is one of ferric chloride, aluminum chloride, zirconium chloride and zinc chloride.

3. A process for the preparation of a two-component elastic feel topcoat for ABS substrates according to any one of claims 1-2, characterized by: The method comprises the following steps: S1, mixing modified emulsion and filler to obtain the A component; mixing solvent and crosslinking agent to obtain the B component; S2, mixing the A component and the B component.

Images