A stone-impact resistant coating for new energy battery casings, its preparation method and application

Abstract

This invention provides an anti-stone-impact coating for new energy battery casings, its preparation method, and its application, belonging to the field of coating technology. The anti-stone-impact coating uses matte PVC resin, which, in synergy with PVC paste resin and PVC blended resin, enables the anti-stone-impact coating to achieve an impact-resistant matte finish. Microsphere foaming agents of different particle sizes, in synergy with the matte PVC resin, further enhance the impact-resistant matte finish and improve the scratch resistance of the anti-stone-impact coating. The anti-stone-impact coating of this invention, with its synergistic effects among its components, yields an anti-stone-impact coating with strong adhesion, high shear strength, and scratch resistance.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to an anti-stone impact coating for new energy battery casings, its preparation method, and its application. Background Technology

[0002] New energy vehicles, as an emerging industry, represent the future direction of the automotive industry. Batteries, as a core component of new energy vehicles, influence the overall performance and safety of the vehicle.

[0003] In existing technologies, the common methods to protect new energy power battery casings include adding a plastic bottom protective plate, spraying anti-stone impact coating, or spraying water-based chassis armor. Currently, the most common method is to spray anti-stone impact coating to form an anti-stone impact coating. This coating covers the surface of the battery casing and can be used to protect the appearance of the battery casing from sand and gravel impacts, as well as maintain the battery casing structure and battery function.

[0004] However, existing stone chip resistant coatings are not scratch resistant. On the one hand, during the production process, during stacking or transportation, bumps and knocks are inevitable. Once scratches appear, they will damage the appearance of the product and cause it to be rejected. On the other hand, during the driving process, too many scratches after stone chips will seriously affect the appearance of the car. Summary of the Invention

[0005] In view of the above-mentioned technical problems existing in the prior art, the present invention aims to provide an anti-stone impact coating for new energy battery casing with anti-scratch function, a preparation method and application.

[0006] One objective of this invention is to provide an anti-stone-impact coating for new energy battery casings, the anti-stone-impact coating comprising the following raw materials in parts by weight:

[0007] 5-20 parts PVC paste resin, 5-10 parts PVC blended resin, 5-10 parts matte PVC resin, 3-5 parts hygroscopic agent, 0.5-3 parts thixotropic agent, 2.5-11 parts microsphere foaming agent, 2-5 parts diluent, 3-5 parts glass microspheres, 2-8 parts toughening agent, 0.7-2 parts adhesion promoter, 0.2-3 parts heat stabilizer, 20-35 parts plasticizer, 15-30 parts nanofiller, and 0.05-1 part color paste.

[0008] The microsphere foaming agent includes at least two microsphere foaming agents with different particle sizes.

[0009] Preferably, the degree of polymerization of the matte PVC resin is 700 to 1000.

[0010] Preferably, the microsphere foaming agent includes microsphere foaming agent A and microsphere foaming agent B.

[0011] Preferably, the microsphere foaming agent A is 2 to 8 parts, and the microsphere foaming agent B is 0.5 to 3 parts.

[0012] Preferably, the microsphere foaming agent A has a particle size of 15–30 μm and an initial foaming temperature of 120–130 °C.

[0013] Preferably, the microsphere foaming agent B has a particle size of 5-15 μm and an initial foaming temperature of 100-120℃.

[0014] Preferably, the toughening agent comprises a core-shell polymer.

[0015] Preferably, the thixotropic agent comprises fumed silica.

[0016] Preferably, the hygroscopic agent comprises molecular sieves and / or calcium oxide.

[0017] Preferably, the adhesion promoter is a low molecular weight polyamide.

[0018] Preferably, the heat stabilizer is an organotin stabilizer or epoxidized soybean oil.

[0019] Preferably, the glass microspheres are solid glass microspheres with a particle size of 100-250 μm.

[0020] A second objective of this invention is to provide a method for preparing the anti-stone chip coating as described above, the method comprising:

[0021] First, add 80-90% plasticizer and diluent, mix well, then add PVC paste resin, PVC blended resin, matte PVC resin, toughening agent and color paste, and stir at low speed for 30-120 minutes.

[0022] Then, add nanofiller, foaming agent, glass microspheres, thixotropic agent, adhesion promoter, heat stabilizer and desiccant, and stir at high speed for 60 to 120 minutes;

[0023] Then, add some of the remaining plasticizer in multiple batches to adjust the viscosity to 50,000-70,000 cps;

[0024] Then, after degassing, it is cured at 20-25°C for 6-12 hours, and then plasticizer is added again to adjust the viscosity to 50,000-70,000 cps. After filtration, the anti-stone chip coating is obtained.

[0025] The third objective of this invention is to provide an application of the anti-stone impact coating as described above, characterized in that, after the anti-stone impact coating is sprayed onto the battery casing, it is baked at 130-145°C for 15-25 minutes to form an anti-stone impact coating.

[0026] Preferably, the thickness of the anti-stone impact coating is 0.8-1.0 mm.

[0027] The beneficial effects of this invention include:

[0028] This invention uses matte PVC resin, which, in synergy with PVC paste resin and PVC blended resin, enables the anti-stone-impact coating to achieve an impact-resistant matte finish. Microsphere foaming agents of different particle sizes, working synergistically with the matte PVC resin, further enhance the impact-resistant matte finish and improve the scratch resistance of the anti-stone-impact coating. The anti-stone-impact coating of this invention, with its components working synergistically, yields an anti-stone-impact coating with strong adhesion, high shear strength, and excellent scratch resistance. Detailed Implementation

[0029] The following description includes certain specific details to provide a comprehensive understanding of the various disclosed embodiments. However, those skilled in the art will recognize that the embodiments can be implemented without employing one or more of these specific details, but using other methods, components, materials, etc.

[0030] Unless otherwise required by this invention, the terms “comprising” and “including” shall be interpreted in an open-ended, inclusive sense, meaning “including but not limited to”.

[0031] Throughout this specification, the terms "an embodiment," "an embodiment," "a preferred embodiment," or "some embodiments" refer to including, in at least one embodiment, a specific reference element, structure, or feature related to that embodiment. Therefore, the phrases "in an embodiment," "in a preferred embodiment," or "in some embodiments" appearing in different places throughout the specification do not necessarily all refer to the same embodiment. Furthermore, specific elements, structures, or features may be combined in one or more embodiments in any suitable manner.

[0032] According to a first aspect of the present invention, an anti-stone-impact coating for a new energy battery casing is provided, the anti-stone-impact coating comprising the following raw materials in parts by weight:

[0033] 5-20 parts PVC paste resin, 5-10 parts PVC blended resin, 5-10 parts matte PVC resin, 3-5 parts hygroscopic agent, 0.5-3 parts thixotropic agent, 2.5-11 parts foaming agent, 2-5 parts diluent, 3-5 parts glass microspheres, 2-8 parts toughening agent, 0.7-2 parts adhesion promoter, 0.2-3 parts heat stabilizer, 20-35 parts plasticizer, 15-30 parts nanofiller, and 0.05-1 part color paste.

[0034] The foaming agent is a microsphere foaming agent, including at least two microsphere foaming agents with different particle sizes.

[0035] In this invention, the PVC paste resin is selected from one or more of the following: emulsion polymerized PVC paste resin, seed emulsion polymerized PVC paste resin, micro-suspension polymerized PVC paste resin, seed micro-suspension polymerized PVC paste resin, or mixed PVC paste resin, preferably mixed PVC paste resin. The PVC paste resin is, for example, in quantities of 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, or 20 parts.

[0036] In this invention, the particle size of the PVC blended resin is 40–80 μm. When the particle size of the PVC blended resin exceeds 80 μm, the PVC blended resin is prone to sedimentation, affecting the processing and application performance of the product. The combined use of the PVC blended resin with a smaller particle size PVC paste resin can reduce the viscosity of the system, improve processing performance, and enhance the shear resistance of the stone chip resistance coating.

[0037] When the amount of PVC blended resin is less than 5 parts, the viscosity reduction effect is not ideal; when the amount of PVC blended resin exceeds 10 parts, it will lead to difficulties in plasticizing and processing. The amount of PVC blended resin is, for example, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, or 10 parts.

[0038] The preferred PVC blending resin is Shanghai Chlor-Alkali SB100.

[0039] In this invention, during the formation of the anti-stone-impact coating, matte PVC resin can cross-link within the anti-stone-impact coating to form a microgel. This results in the anti-stone-impact coating having different viscoelastic properties in its microstructure, creating minute permanent deformations on the surface of the coating. These permanent deformations can be, for example, irregular or wrinkled structures. These minute permanent deformations diffusely reflect and scatter light, reducing the gloss of the product surface and giving the anti-stone-impact coating an anti-impact matte finish. When the amount of matte PVC resin is less than 5 parts, continuous minute permanent deformations cannot form on the surface of the anti-stone-impact coating, resulting in poor anti-impact matte finish. When the amount of matte PVC resin is greater than 10 parts, the film-forming effect is poor.

[0040] The matte PVC resin is, for example, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, or 10 parts.

[0041] The matte PVC resin is preferably SD-13 from Nippon Chiso Chemical Co., Ltd.

[0042] This invention also employs microsphere foaming agents of different particle sizes. On one hand, during heating and foaming, microsphere foaming agents of different particle sizes can form uneven structures of different sizes on the surface of the anti-stone-impact coating, which, in synergy with the matte PVC resin, can further enhance the anti-impact matte effect. On the other hand, after heating and foaming, the microsphere foaming agent can form expandable microspheres with good elasticity. When the anti-stone-impact coating encounters external impacts or scratches, the expandable microspheres can absorb energy and withstand a certain amount of pressure, improving scratch resistance. The microsphere foaming agent is, for example, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, or 10 parts.

[0043] In some preferred embodiments of the present invention, the degree of polymerization of the matte PVC resin is 700 to 1000.

[0044] When the degree of polymerization of the matte PVC resin is less than 700, a large number of small, bonded particles will exist on the surface of the anti-stone chip coating. These particles are irregular in shape and have many small particles on the surface, which will reduce the coating's compressive strength and consequently its scratch resistance. When the degree of polymerization of the matte PVC resin is greater than 1000, the viscosity of the coating system increases, which is not conducive to improving processing performance and leads to a decrease in the shear resistance and adhesion of the anti-stone chip coating.

[0045] In some preferred embodiments of the present invention, the microsphere foaming agent includes microsphere foaming agent A and microsphere foaming agent B.

[0046] Preferably, the microsphere foaming agent A is 2 to 8 parts, and the microsphere foaming agent B is 0.5 to 3 parts.

[0047] Preferably, the microsphere foaming agent A has a particle size of 15–30 μm and an initial foaming temperature of 120–130 °C.

[0048] Preferably, the microsphere foaming agent B has a particle size of 5-15 μm and an initial foaming temperature of 100-120℃.

[0049] In this invention, microsphere foaming agent B with a particle size of 5–15 μm preferentially foams to form smaller, elastically expanded microspheres, while microsphere foaming agent A with a particle size of 15–30 μm foams subsequently to form larger, elastically expanded microspheres. The elastically expanded microspheres of different sizes form uneven structures of varying sizes on the surface of the stone-impact resistant coating, which, in synergy with the matte PVC resin, further enhances the impact resistance and matte finish.

[0050] The microsphere foaming agent A is preferably Akzo909DU80, and the microsphere foaming agent B is preferably Akzo051DU40.

[0051] In this invention, the toughening agent is, for example, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, or 8 parts.

[0052] In some preferred embodiments of the present invention, the toughening agent comprises a core-shell polymer.

[0053] In this invention, the core of the core-shell polymer is polybutadiene-styrene rubber, and the shell is polymethyl methacrylate (PMMA). Adding core-shell polymer powder for modification can improve the toughness of the stone-impact resistant coating. Furthermore, the core-shell polymer powder in the stone-impact resistant coating makes the refractive index inside the coating uneven, which reduces the light transmittance and improves the scratch resistance.

[0054] The toughening agent is preferably Arkema Clearstrength XT100 or LG Chem EX700.

[0055] In this invention, the thixotropic agent is, for example, 0.5 parts, 0.7 parts, 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, or 3 parts.

[0056] In some preferred embodiments of the present invention, the thixotropic agent comprises fumed silica.

[0057] In this invention, the hygroscopic agent is, for example, 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, or 5 parts.

[0058] In some preferred embodiments of the present invention, the hygroscopic agent comprises molecular sieves and / or calcium oxide, preferably calcium oxide.

[0059] In this invention, the adhesion promoter is, for example, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, or 2 parts.

[0060] In some preferred embodiments of the present invention, the adhesion promoter is a low molecular weight polyamide.

[0061] The adhesion promoter is preferably Wuxi Shengyi 530E and / or Evonik Nourybond 382.

[0062] In this invention, the heat stabilizer is, for example, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, or 2 parts.

[0063] In some preferred embodiments of the present invention, the heat stabilizer is an organotin stabilizer and / or epoxidized soybean oil, preferably epoxidized soybean oil.

[0064] In this invention, the glass microspheres are, for example, 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, or 5 parts.

[0065] In some preferred embodiments of the present invention, the glass microspheres are solid glass microspheres with a particle size of 100-250 μm. The addition of glass microspheres further promotes the formation of an uneven structure on the surface of the anti-stone chip coating, generating diffuse reflection and scattering of light, thus enhancing the scratch resistance effect.

[0066] In this invention, the plasticizer is, for example, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, or 35 parts.

[0067] In some preferred embodiments of the present invention, the plasticizer includes DOP and / or DINP, preferably DINP.

[0068] In this invention, the nanofiller is, for example, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, or 30 parts.

[0069] In some preferred embodiments of the present invention, the nanofiller includes nano-calcium carbonate, which can improve the rheological properties of the stone impact resistant coating, improve the formability of the stone impact resistant coating, and has the effect of toughening and reinforcing.

[0070] In this invention, the diluent is, for example, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.6 parts, 4.8 parts, or 5 parts.

[0071] In some preferred embodiments of the present invention, the diluent includes one or more of D40, D80, IP40 or IP80, preferably IP80.

[0072] In this invention, the color paste is, for example, 0.05 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, or 1 part.

[0073] According to a second aspect of the present invention, a method for preparing the anti-stone chip coating as described above is provided, the method comprising:

[0074] First, add 80-90% plasticizer and diluent, mix well, then add PVC paste resin, PVC blended resin, matte PVC resin, toughening agent and color paste, and stir at low speed for 30-120 minutes.

[0075] Then, add nanofiller, foaming agent, glass microspheres, thixotropic agent, adhesion promoter, heat stabilizer and desiccant, and stir at high speed for 60 to 120 minutes;

[0076] Then, add some of the remaining plasticizer in multiple batches to adjust the viscosity to 50,000-70,000 cps;

[0077] Specifically, after each addition of plasticizer, stir for 20 to 40 minutes and test the viscosity. When the viscosity reaches 50,000 to 70,000 cps, stop adding plasticizer.

[0078] Then, after degassing, it is cured at 20-25°C for 6-12 hours, and then plasticizer is added again to adjust the viscosity to 50,000-70,000 cps. After filtration, the anti-stone chip coating is obtained.

[0079] Specifically, viscosity was tested using a Brookfield 1.1 viscometer #7 at 20 rpm.

[0080] According to a second aspect of the present invention, an application of the anti-stone impact coating as described above is provided, characterized in that, after the anti-stone impact coating is sprayed onto the battery casing, it is baked at 130-145°C for 15-25 minutes to form an anti-stone impact coating.

[0081] Preferably, the thickness of the anti-stone impact coating is 0.8 to 1.0 mm.

[0082] Example

[0083] The present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0084] In the following embodiments, unless otherwise specified, all raw material components are commercially available products.

[0085] This invention includes Comparative Examples 1-4 and Examples 1-9. The raw materials used in the Examples and Comparative Examples are as follows:

[0086] The PVC paste resin is a mixed-method PVC paste resin; the PVC blended resin is Shanghai Chlor-Alkali SB100; the matting PVC resin is Nippon Chiso Chemical SD-13; the hygroscopic agent is calcium oxide; the thixotropic agent is fumed silica; microsphere foaming agent A is Akzo909DU80; microsphere foaming agent B is Akzo051DU40; the diluent is IP80; the glass microspheres are solid glass microspheres with a particle size of 150-250μm; the toughening agent is Arkema Clearstrength XT100; the adhesion promoter is Evonik Nourybond 382; the heat stabilizer is epoxidized soybean oil; the plasticizer is DINP; the nanofiller is nano-calcium carbonate with a particle size of 60-80nm; and the color paste is black color paste.

[0087] The mass ratios of each component in the comparative examples and embodiments are shown in Table 1.

[0088] Table 1 shows the mass ratios of each component in Comparative Examples 1-4 and Examples 1-9.

[0089]

[0090] Preparation methods of anti-stone chip coatings described in Comparative Examples 1-4 and Examples 1-9:

[0091] First, add 80-90% plasticizer and diluent, mix well, then add PVC paste resin, PVC blended resin, matte PVC resin, toughening agent and color paste, and stir at low speed for 30-120 minutes.

[0092] Then, add nanofillers, foaming agents, glass microspheres, thixotropic agents, adhesion promoters, heat stabilizers, and hygroscopic agents, and stir at high speed for 60–120 minutes.

[0093] Then, add some of the remaining plasticizer in multiple batches to adjust the viscosity to 50,000-70,000 cps.

[0094] After each addition of plasticizer, stir for 20-40 minutes and test the viscosity. When the viscosity reaches 50,000-70,000 cps, stop adding plasticizer.

[0095] Then, after degassing, it is cured at 20-25°C for 6-12 hours, and then plasticizer is added again to adjust the viscosity to 50,000-70,000 cps. After filtration, the anti-stone chip coating is obtained.

[0096] Then, prepare the coated test pieces:

[0097] After the anti-stone impact coating is sprayed onto the test panel, it is baked at 130-145°C for 15-25 minutes to form an anti-stone impact coating with a thickness of 0.9 mm.

[0098] Then, the anti-stone chip coatings described in Examples 1-4 and Examples 1-9 were tested as follows:

[0099] (1) Adhesion test

[0100] Place the test board on a horizontal table. Use a utility knife and a ruler to draw two parallel lines 5mm apart on its surface. The utility knife should cut into the substrate without damaging it. Use the utility knife to cut the adhesive surface between the parallel lines and gently pry it up to separate the anti-stone-impact base coat from the substrate. Hold the lifted part with your hand, applying force perpendicular to the substrate, until the lifted part breaks. Determine the adhesion level according to Table 2.

[0101] Table 2 Adhesion Grade Standards

[0102] Adhesion rating Judgment criteria Level 1 Non-adhesive; the coating has no adhesion to the substrate and detaches completely from it. Level 2 Some of the adhering material remained on the substrate. Level 3 With sufficient adhesion, over 90% of the coating remains on the substrate, with only a small amount detaching. Level 4 Excellent adhesion; 100% of the material remains on the substrate and tears easily.

[0103] (2) Shear strength

[0104] The anti-stone impact coating was applied between two steel plates, with a coating area of ​​25*25mm. It was fixed with dovetail clips. After baking, the excess adhesive was removed. The adhesive layer thickness was 2mm. The steel plates were stretched at a speed of 50mm / min to test the shear strength of the anti-stone impact coating.

[0105] (3) Abrasion resistance

[0106] Test pieces with a base material of 100mm×100mm×1mm steel plate and a coating thickness of 0.5mm±0.05mm were used. After curing according to regulations, they were placed at room temperature for 24 hours. The test pieces were fixed on a stone impact tester with the coating facing upwards. M6 nuts (compliant with GB / T 41—2000, the same below) were used instead of stones and placed in a funnel, allowing them to fall freely down the tube to impact the coating surface at a flow rate of approximately 80g / s±20g / s. The test was stopped when the coating blistered or cracked, exposing the base material surface. The mass of the nuts was weighed or calculated.

[0107] (4) Flowability

[0108] On the designated substrate, apply the anti-stone chip coating using a mold with an area of ​​40mm*60mm and a thickness of 2mm. After application, place the test plate vertically for 20 minutes (60mm is the long side) and record the distance the coating slides off the steel plate.

[0109] (5) Scratch resistance

[0110] The paperclip scratching method uses a paperclip as the scratching head. The sample size is typically 152mm × 152mm, with a load of 0.75kg. During testing, the sample is placed on the base plate of the testing device, with its four edges parallel to the base plate. The loaded paperclip is released, and the sample is slowly pulled at a steady speed to scratch it. The scratch marks should be parallel to the sample edges, with a sliding distance of at least 100mm. A ruler can be used to guide the sample to ensure the scratch marks are parallel to the sample edges, and the scratch distance can be recorded. After scratching in one direction, the sample is rotated 90 degrees and pulled along the other edge until all four directions are scratched. The degree of scratching is evaluated visually. The scratch grade is determined according to Table 3.

[0111] Table 3 Scratch Resistance Rating Standards

[0112] grade Judgment criteria Level 5 The sample surface has severe scratches and is damaged. Level 4 The sample surface has significant scratches and the sample is slightly damaged. Level 3 The sample surface has clear scratch marks and a noticeable whitening. Level 2 The sample surface has slight scratches and slight whitening. Level 1 The sample had no scratches.

[0113] The test results of Comparative Examples 1-4 and Examples 1-9 are shown in Table 4.

[0114] Table 4 shows the test results of Comparative Examples 1-4 and Examples 1-9.

[0115] Adhesion rating Shear strength, MPa Abrasion resistance, kg Flowability, mm Scratch rating Comparative Example 1 Level 3 0.9 16 1 Level 5 Comparative Example 2 Level 4 0.8 20 0 Level 2 Comparative Example 3 Level 3 0.9 18 0 Level 4 Comparative Example 4 Level 3 0.8 18 0 Level 4 Example 1 Level 4 1.1 23 0 Level 1 Example 2 Level 4 1.0 19 0 Level 3 Example 3 Level 4 0.9 19 0 Level 3 Example 4 Level 4 0.9 20 0 Level 3 Example 5 Level 4 1.0 19 0 Level 3 Example 6 Level 4 1.0 21 0 Level 2 Example 7 Level 4 1.1 20 0 Level 2 Example 8 Level 4 1.0 20 0 Level 2 Example 9 Level 4 1.1 20 0 Level 2

[0116] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of the invention as described above, which are not provided in detail for the sake of brevity.

[0117] The embodiments of this invention are intended to cover all such substitutions, modifications, and variations falling within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this invention should be included within the protection scope of this invention.

Claims

1. A stone-impact resistant coating for new energy battery casings, characterized in that, The anti-stone chip coating comprises the following raw materials in parts by weight: 5-20 parts PVC paste resin, 5-10 parts PVC blended resin, 5-10 parts matte PVC resin, 3-5 parts hygroscopic agent, 0.5-3 parts thixotropic agent, 2.5-11 parts foaming agent, 2-5 parts diluent, 3-5 parts glass microspheres, 2-8 parts toughening agent, 0.7-2 parts adhesion promoter, 0.2-3 parts heat stabilizer, 20-35 parts plasticizer, 15-30 parts nanofiller, and 0.05-1 parts color paste; The foaming agent includes microsphere foaming agent A and microsphere foaming agent B with different particle sizes; The microsphere foaming agent A is 2-8 parts, and the microsphere foaming agent B is 0.5-3 parts; The microsphere foaming agent A has a particle size of 15~30μm and an initial foaming temperature of 120~130℃; The microsphere foaming agent B has a particle size of 5~15μm and an initial foaming temperature of 100~120℃.

2. The anti-stone-impact coating for new energy battery casings as described in claim 1, characterized in that, The degree of polymerization of the matte PVC resin is 700~1000.

3. The anti-stone-impact coating for new energy battery casings as described in claim 1, characterized in that, The toughening agent comprises a core-shell polymer.

4. The anti-stone-impact coating for new energy battery casings as described in claim 1, characterized in that, The thixotropic agent includes fumed silica.

5. The anti-stone-impact coating for new energy battery casings as described in claim 1, characterized in that, The hygroscopic agent includes molecular sieves and / or calcium oxide.

6. The anti-stone-impact coating for new energy battery casings as described in claim 1, characterized in that, The adhesion promoter is a low molecular weight polyamide.

7. The anti-stone-impact coating for new energy battery casings as described in claim 1, characterized in that, The heat stabilizer is an organotin stabilizer or epoxidized soybean oil.

8. The anti-stone-impact coating for new energy battery casings as described in claim 1, characterized in that, The glass microspheres are solid glass microspheres with a particle size of 100~250μm.

9. A method for preparing an anti-stone chip coating as described in any one of claims 1 to 8, characterized in that, The preparation method includes: First, add 80-90% of plasticizer and diluent, mix well, then add PVC paste resin, PVC blended resin, matte PVC resin, toughening agent and color paste, and stir at low speed for 30-120 minutes. Then, add nanofiller, microsphere foaming agent, glass microspheres, thixotropic agent, adhesion promoter, heat stabilizer and hygroscopic agent, and stir at high speed for 60~120min; Then, add some of the remaining plasticizer in multiple batches to adjust the viscosity to 50,000-70,000 cps; Then, after degassing, it is cured at 20~25℃ for 6~12 hours, and then plasticizer is added again to adjust the viscosity to 50,000-70,000 cps. After filtration, the anti-stone chip coating is obtained.

10. The application of an anti-stone chip coating as described in any one of claims 1 to 8, characterized in that, After the anti-stone impact coating is sprayed onto the battery casing, it is baked at 130~145℃ for 15~25 minutes to form an anti-stone impact coating.

11. An application of the anti-stone chip coating as described in claim 10, characterized in that, The thickness of the anti-stone chip coating is 0.8~1.0 mm.

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