High-voltage-resistant wear-resistant insulating photocureable coating, preparation method thereof and power battery shell coating

Abstract

The invention belongs to the technical field of insulating materials, and particularly relates to a high-voltage-resistant wear-resistant insulating photocureable coating, a preparation method thereof and a power battery shell coating. The high-pressure-resistant wear-resistant insulating photocureable coating is formed by mixing sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate and a photoinitiator; the sulfonated bisphenol A epoxy acrylate is prepared by carrying out epoxy ring-opening reaction on bisphenol A epoxy resin and 2-acrylamide-2-methylpropanesulfonic acid under the catalytic action; and the modified polyurethane acrylate is bifunctional organic silicon grafted polyurethane acrylate. A coating for a power battery shell, which is formed by the high-voltage-resistant wear-resistant insulating photocureable coating disclosed by the invention, is excellent in insulating property, can meet the insulating requirement of the power battery shell under a 800V framework at the present stage, and in addition, the formed coating has excellent wear resistance and shows good application and popularization prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of insulating materials, in particular to a high-voltage and wear-resistant insulating light-curing coating and a preparation method thereof, and a power battery shell coating. Background Art

[0002] New energy vehicles, characterized by low noise, high driving stability, and zero-emission, environmentally friendly features, are standing out in the rapidly developing automotive industry. As a core component of new energy vehicles, the insulation performance of batteries is a crucial safety indicator. Battery cells are a key component of batteries. As driving range increases, the number of battery packs connected in series increases, and the spacing between adjacent cells decreases, high-density battery packs increase the impact of contact between individual cells and the external environment during use. Failure to properly insulate the battery can lead to increased internal voltage, causing short circuits and leakage. Spraying a layer of insulating coating on the surface of the battery cell can effectively prevent internal short circuits, avoid thermal runaway and fire, and improve the durability and stability of the battery cell, extending its service life.

[0003] At present, traditional power batteries are often coated with PET blue film for insulation. However, with the rapid growth of the new energy vehicle market in the past two years, a large number of new models with 800V high-voltage platforms have emerged. Faced with a significant voltage increase, it is difficult for the blue film insulation solution to meet various performance requirements. For example, the 800V voltage platform requires the insulation layer to withstand a breakdown voltage of 3000V to 4000V, while the blue film solution only supports a maximum of 2500V, resulting in a high risk of breakdown under high voltage loads. High-voltage resistant light-curing coatings have become a viable solution. The coating is quickly applied to the battery cell by spraying and rapid light curing.

[0004] Light-curing insulating coatings have been applied to power battery housings, such as those produced by Parker of the United States. Domestic research on UV-curable insulating coatings, for example, includes CN103408716A, which uses polyurethane acrylate as the main component to prepare a UV-curable insulating coating, but its insulation performance is not ideal. CN114672223A, which uses modified epoxy acrylate as the main component, generally meets current application requirements, but the introduction of aramid nanofibers inevitably increases costs, hindering further industrialization.

[0005] In addition, during the transportation of battery cells and the driving of new energy electric vehicles, the battery cell casing will inevitably be worn and collided, causing the battery pack coating to fall off, thereby reducing the insulation effect under high-voltage environment. Summary of the Invention

[0006] Based on the deficiencies in the above-mentioned prior art, the present invention provides a high-voltage and wear-resistant insulating photocurable coating, a preparation method thereof, and a power battery shell coating. The present invention uses sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate, and a photoinitiator as raw materials, and mixes them to obtain a high-voltage and wear-resistant insulating photocurable coating; sulfonated bisphenol A epoxy acrylate is prepared by undergoing an epoxy ring-opening reaction of bisphenol A epoxy resin and 2-acrylamide-2-methylpropanesulfonic acid under the catalytic action. The high-voltage and wear-resistant insulating photocurable coating obtained by the method of the present invention is resistant to high voltage, wear-resistant, and has excellent insulation properties after curing. The raw materials are easily available and inexpensive, and the technical defects of the prior art photocurable insulating coating are overcome.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for preparing a high-voltage wear-resistant insulating light-curing coating, comprising the following steps:

[0009] Under an inert atmosphere, bisphenol A epoxy resin and an inhibitor, hydroquinone, are mixed to obtain a resin system; an aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and a catalyst, triphenylphosphine, are added to the resin system to carry out an epoxy ring-opening reaction, whereby the epoxy groups on the main chain of the bisphenol A epoxy resin are attacked by the strongly acidic sulfonic acid groups of the 2-acrylamide-2-methylpropanesulfonic acid to generate sulfonate bonds and hydroxyl groups; after the reaction, water is separated to obtain sulfonated bisphenol A epoxy acrylate, and the insulation effect of the sulfonated bisphenol A epoxy acrylate is improved through sulfonation modification. During the preparation of sulfonated bisphenol A epoxy acrylate, the role of adding hydroquinone is to prevent the occurrence of free radical polymerization to ensure the controllability of the reaction and the quality of the product. Specifically, on the one hand, during the reaction, free radicals triggered by heat, light or impurities may be generated. These free radicals will cause unnecessary polymerization of the sulfonated bisphenol A epoxy acrylate, thereby affecting the yield and purity of the sulfonated bisphenol A epoxy acrylate. On the other hand, the sulfonated bisphenol A epoxy acrylate has high reactivity and is easily affected by self-polymerization or over-polymerization initiated by free radicals. The presence of hydroquinone can continue to inhibit free radical activity after the reaction is completed, thereby improving the stability of the sulfonated bisphenol A epoxy acrylate.

[0010] The reaction equation for the preparation of sulfonated bisphenol A epoxy acrylate is:

[0011]

[0012] Weigh the following raw materials in parts by weight: 50 to 100 parts of sulfonated bisphenol A epoxy acrylate, 20 to 100 parts of modified polyurethane acrylate, and 1 to 5 parts of photoinitiator, and set aside.

[0013] Among them, the modified polyurethane acrylate is bifunctional silicone grafted polyurethane acrylate, and the bifunctional silicone grafted polyurethane acrylate is purchased from Shanghai Yinchang New Materials Co., Ltd. with model number YC3106.

[0014] The sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate and a photoinitiator are mixed evenly, heated and mixed evenly and defoamed to obtain a high-voltage and wear-resistant insulating light-curing coating.

[0015] Preferably, the mass ratio of bisphenol A epoxy resin to hydroquinone is 150-250:0.5-1.5.

[0016] Preferably, the mass ratio of bisphenol A epoxy resin to 2-acrylamide-2-methylpropanesulfonic acid is 150-250:50-100. The mass ratio of bisphenol A epoxy resin to 2-acrylamide-2-methylpropanesulfonic acid has an important influence on the sulfonation modification process. Within this ratio, the sulfonation modification ratio is high.

[0017] Preferably, the conditions for the epoxy ring-opening reaction are: heating at 60° C. to 90° C. for 4 h to 8 h.

[0018] Preferably, the high-voltage wear-resistant insulating photocuring coating also includes 0 to 60 parts of a reactive diluent, and the reactive diluent is selected from one or more of polyethylene glycol diacrylate, tripropylene glycol diacrylate, and 1,6-hexanediol diacrylate. The reactive diluent facilitates uniform mixing of the raw materials, and spraying can be performed if it contains a reactive diluent.

[0019] Preferably, the high-voltage wear-resistant insulating photocuring coating also includes 0 to 30 parts of wear-resistant filler, which increases the wear resistance. The wear-resistant filler is selected from one or more of aluminum oxide, zinc oxide, silicon dioxide, zirconium oxide, and yttrium oxide, and the size of the wear-resistant filler is 50nm to 10μm.

[0020] Preferably, the high-voltage wear-resistant insulating light-curing coating further comprises 5 to 15 parts of a pigment, and the pigment is a photosensitive oil printing agent with a coloring effect.

[0021] The present invention also protects the high-voltage wear-resistant insulating light-curing coating prepared by the preparation method.

[0022] The present invention also protects the power battery shell coating, which is prepared by free radical polymerization of high-voltage wear-resistant insulating light-curing coating under ultraviolet light irradiation.

[0023] Preferably, the power battery shell coating is prepared according to the following steps: after the high-voltage wear-resistant insulating photocurable coating is coated into a liquid film, it is irradiated under 405nm ultraviolet light for 1s to 10s. At this time, the photoinitiator forms free radicals, and the sulfonated bisphenol A epoxy acrylate and the modified polyurethane acrylate undergo free radical polymerization under the initiation of the photoinitiator to obtain the power battery shell coating, that is, the liquid photocurable coating is cured into a solid high-voltage wear-resistant insulating power battery shell coating.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention uses bisphenol A epoxy resin and 2-acrylamide-2-methylpropanesulfonic acid as raw materials, undergoing an epoxy ring-opening reaction under catalysis to produce sulfonated bisphenol A epoxy acrylate. The epoxy groups on the bisphenol A epoxy resin backbone are attacked by the strongly acidic sulfonic acid groups of the 2-acrylamide-2-methylpropanesulfonic acid, forming sulfonate ester bonds and hydroxyl groups. The sulfonation modification introduces weakly bound electrons, resulting in a relatively significant polarization effect, weakening the molecular polarity of the sulfonated bisphenol A epoxy acrylate. This improves the insulating effect of the sulfonated bisphenol A epoxy acrylate, resulting in a high-voltage, wear-resistant, insulating, light-cured coating produced using the sulfonated bisphenol A epoxy acrylate having better insulating properties. Furthermore, sulfonation increases molecular flexibility, improves the elongation at break of the sulfonated bisphenol A epoxy acrylate, and raises the pyrolysis temperature of the high-voltage, wear-resistant, insulating, light-cured coating.

[0026] The present invention uses sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate, and a photoinitiator as raw materials to produce a high-voltage, wear-resistant, insulating, light-curing coating. Epoxy acrylate is a photosensitive resin that is inexpensive, has strong adhesion, excellent chemical resistance, and relatively high strength. The modified polyurethane acrylate is a bifunctional silicone-grafted polyurethane acrylate. The silicone grafting also enhances the insulating properties of the high-voltage, wear-resistant, insulating, light-curing coating.

[0027] The high-voltage wear-resistant insulating light-curing coating of the present invention has excellent wear resistance after being cured. The addition of silicone to the bifunctional silicone-grafted polyurethane acrylate increases the flexibility of the molecular chain and reduces the friction coefficient.

[0028] 2. The photoinitiator of the present invention generates free radicals under the irradiation of ultraviolet light, and the free radicals initiate the polymerization reaction of the acrylic resin. Therefore, the sulfonated bisphenol A epoxy acrylate and the modified polyurethane acrylate are initiated by the photoinitiator to undergo free radical polymerization.

[0029] 3. The wear-resistant filler of the present invention can also be modified by a silane coupling agent to enhance the connection between the wear-resistant filler and the sulfonated bisphenol A epoxy acrylate and the modified polyurethane acrylate, thereby reducing internal defects caused by organic and inorganic incompatibility, and also introducing silicon side chains to further enhance the insulation performance of the high-voltage wear-resistant insulating light-curing coating.

[0030] 4. After forming a 70μm thick coating on the aluminum alloy surface, the high-voltage wear-resistant insulating light-curing coating of the present invention has a breakdown voltage of 8440V, which is superior to the existing PET blue film and foreign imported UV light curing coating has better insulation performance.

[0031] 5. After the high-pressure wear-resistant insulating light-curing coating of the present invention is used to form a coating, a friction and wear test is carried out, and the surface is almost undamaged, while the existing PET blue film and the imported foreign Obvious scratches appear on the surface of the UV light-curing coating, so compared with the light-curing coating in the prior art, the high-voltage wear-resistant insulating light-curing coating of the present invention has better friction and wear resistance.

[0032] 6. The present invention conducts friction and wear tests on the high-voltage wear-resistant insulating light-curing coating. The results show that after the high-voltage wear-resistant insulating light-curing coating forms a coating, the friction coefficient is low and there is no damage on the surface after the test, which can further improve the applicability of new energy power batteries and extend their service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a real picture of spraying the high-pressure, wear-resistant, insulating light-curing coating of Example 6 on the surface of aluminum plates of different shapes.

[0035] Figure 2 The force and displacement curves of the overlap shear test using the high-pressure wear-resistant insulating light-curing coating of Example 6 are shown.

[0036] Figure 3 This is a surface diagram after a cross-crushing adhesion test is performed on the high-voltage wear-resistant insulating light-curing coating of Example 6.

[0037] Figure 4 For example 6 high voltage wear resistant insulating light curing coating, BPET is blue film and The friction coefficient of UV light-curing coating changes over time.

[0038] Figure 5 5x optical microscope surface morphology of different samples under the same wear conditions, where A is the high-voltage wear-resistant insulating light-curing coating of Example 6, BPET is the blue film, and C is UV light curing coating. DETAILED DESCRIPTION

[0039] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The experimental methods described in the embodiments of the present invention are all conventional methods unless otherwise specified.

[0040] Taking into account the technical problems of the existing photocurable insulating coatings such as insulation, manufacturing cost and wear resistance, the present invention provides a high-voltage and wear-resistant insulating photocurable coating. The present invention first uses 2-acrylamide-2-methylpropanesulfonic acid to sulfonate-modify bisphenol A epoxy resin, so that the obtained sulfonated bisphenol A epoxy acrylate has excellent insulation performance and flexibility; then, sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate and photoinitiator are used as raw materials to mix to obtain a high-voltage and wear-resistant insulating photocurable coating. When the high-voltage and wear-resistant insulating photocurable coating is irradiated with ultraviolet light, the photoinitiator forms free radicals, and the sulfonated bisphenol A epoxy acrylate and the modified polyurethane acrylate undergo free radical polymerization reaction under the initiation of the photoinitiator, thereby forming a high-voltage and wear-resistant insulating power battery shell coating. Among them, the addition of silicone to the bifunctional silicone-grafted polyurethane acrylate increases the flexibility of the molecular chain and reduces the friction coefficient; at the same time, the grafting of silicone also improves the insulating properties of the high-voltage and wear-resistant insulating photocuring coating; epoxy acrylate is cheap and effectively reduces costs; the high-voltage and wear-resistant insulating photocuring coating of the present invention effectively overcomes the technical defects of the existing photocuring insulating coating.

[0041] The technical solution of the present invention is further explained by using embodiments below, which are as follows:

[0042] Example 1

[0043] A method for preparing a high-voltage wear-resistant insulating light-curing coating comprises the following steps:

[0044] S1. Weigh the raw materials according to the following weight parts: 50 parts of sulfonated bisphenol A epoxy acrylate, 50 parts of modified polyurethane acrylate, 10 parts of reactive diluent, and 5 parts of photoinitiator, and set them aside; except for sulfonated bisphenol A epoxy acrylate, the remaining components are purchased from the market.

[0045] S2. Preparation of sulfonated bisphenol A epoxy acrylate: bisphenol A epoxy resin and hydroquinone were added into a container at a mass ratio of 200:1, and stirred and mixed at 90° C. under a nitrogen atmosphere to obtain a resin system.

[0046] 75 parts of a 50 wt% aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and 2 parts of triphenylphosphine were added to the resin system, and the mixture was stirred at 90° C. for 6 h. Water was removed by rotary evaporation to obtain sulfonated bisphenol A epoxy acrylate.

[0047] S3. Preparation of high-voltage and wear-resistant insulating photocuring coating: sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate, reactive diluent and photoinitiator are added into a container, mechanically stirred for 6 hours to obtain a mixed resin, and then the mixed resin is placed in a 55°C oven for heat treatment for 12 hours, then mixed evenly and defoamed to obtain a high-voltage and wear-resistant insulating photocuring coating.

[0048] Example 2

[0049] A method for preparing a high-voltage wear-resistant insulating light-curing coating comprises the following steps:

[0050] S1. Weigh the raw materials according to the following weight parts: 80 parts of sulfonated bisphenol A epoxy acrylate, 40 parts of modified polyurethane acrylate, 5 parts of reactive diluent, and 5 parts of photoinitiator, and set them aside; except for sulfonated bisphenol A epoxy acrylate, the remaining components are purchased from the market.

[0051] S2. Preparation of sulfonated bisphenol A epoxy acrylate: bisphenol A epoxy resin and hydroquinone were added into a container at a mass ratio of 200:1, and stirred and mixed at 90° C. under a nitrogen atmosphere to obtain a resin system.

[0052] 75 parts of a 50 wt% aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and 2 parts of triphenylphosphine were added to the resin system, and the mixture was stirred at 90° C. for 6 h. Water was removed by rotary evaporation to obtain sulfonated bisphenol A epoxy acrylate.

[0053] S3. Preparation of high-voltage and wear-resistant insulating photocuring coating: sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate, reactive diluent and photoinitiator are added into a container, mechanically stirred for 6 hours to obtain a mixed resin, and then the mixed resin is placed in a 55°C oven for heat treatment for 12 hours, then mixed evenly and defoamed to obtain a high-voltage and wear-resistant insulating photocuring coating.

[0054] Example 3

[0055] A method for preparing a high-voltage wear-resistant insulating light-curing coating comprises the following steps:

[0056] S1. Weigh the raw materials according to the following weight parts: 100 parts of sulfonated bisphenol A epoxy acrylate, 60 parts of modified polyurethane acrylate, and 5 parts of photoinitiator, and set aside; except for sulfonated bisphenol A epoxy acrylate, the remaining components are purchased from the market.

[0057] S2. Preparation of sulfonated bisphenol A epoxy acrylate: bisphenol A epoxy resin and hydroquinone were added into a container at a mass ratio of 200:1, and stirred and mixed at 90° C. under a nitrogen atmosphere to obtain a resin system.

[0058] 75 parts of a 50 wt% aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and 2 parts of triphenylphosphine were added to the resin system, and the mixture was stirred at 90° C. for 6 h. Water was removed by rotary evaporation to obtain sulfonated bisphenol A epoxy acrylate.

[0059] S3. Preparation of high-voltage and wear-resistant insulating photocuring coating: sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate and photoinitiator are added into a container, mechanically stirred for 6 hours to obtain a mixed resin, and then the mixed resin is placed in a 55°C oven for heat treatment for 6 hours, further mixed evenly and defoamed to obtain a high-voltage and wear-resistant insulating photocuring coating.

[0060] Example 4

[0061] A method for preparing a high-voltage wear-resistant insulating light-curing coating comprises the following steps:

[0062] S1. Weigh the following raw materials according to weight: 100 parts sulfonated bisphenol A epoxy acrylate, 60 parts modified polyurethane acrylate, 5 parts photoinitiator, and 20 parts aluminum oxide with a particle size of 10 μm. Except for the sulfonated bisphenol A epoxy acrylate, all other components were purchased commercially.

[0063] S2. Preparation of sulfonated bisphenol A epoxy acrylate: bisphenol A epoxy resin and hydroquinone were added into a container at a mass ratio of 200:1, and stirred and mixed at 90° C. under a nitrogen atmosphere to obtain a resin system.

[0064] 75 parts of a 50 wt% aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and 2 parts of triphenylphosphine were added to the resin system, and the mixture was stirred at 90° C. for 6 h. Water was removed by rotary evaporation to obtain sulfonated bisphenol A epoxy acrylate.

[0065] S3. Preparation of high-voltage and wear-resistant insulating photocuring coating: sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate and photoinitiator are added into a container, mechanically stirred for 6 hours to obtain a mixed resin, and then the mixed resin is placed in a 55°C oven for heat treatment for 10 hours, and then filler alumina is added, and the mixing and stirring is continued for 1 hour to obtain a mixed product, which is further mixed evenly and defoamed to obtain a high-voltage and wear-resistant insulating photocuring coating for power battery casings.

[0066] Example 5

[0067] A method for preparing a high-voltage wear-resistant insulating light-curing coating comprises the following steps:

[0068] S1. Weigh the following raw materials according to weight: 100 parts of sulfonated bisphenol A epoxy acrylate, 60 parts of modified polyurethane acrylate, 5 parts of photoinitiator, and 10 parts of aluminum oxide with a particle size of 500 nm. Except for the sulfonated bisphenol A epoxy acrylate, all other components were purchased commercially.

[0069] S2. Preparation of sulfonated bisphenol A epoxy acrylate: bisphenol A epoxy resin and hydroquinone were added into a container at a mass ratio of 200:1, and stirred and mixed at 90° C. under a nitrogen atmosphere to obtain a resin system.

[0070] 75 parts of a 50 wt% aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and 2 parts of triphenylphosphine were added to the resin system, and the mixture was stirred at 90° C. for 6 h. Water was removed by rotary evaporation to obtain sulfonated bisphenol A epoxy acrylate.

[0071] S3. Preparation of high-voltage and wear-resistant insulating photocuring coating: add sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate and photoinitiator into a container, stir mechanically for 6 hours to obtain a mixed resin, then place the mixed resin into a 55°C oven for heat treatment for 8 hours, add filler alumina, continue mixing and stirring for 1 hour to obtain a mixed product, further mix evenly and remove bubbles to obtain a high-voltage and wear-resistant insulating photocuring coating.

[0072] The high-voltage, wear-resistant, insulating light-curing coatings of Examples 1 to 5 were used to form a coating. The method was as follows: after forming a liquid film of the high-voltage, wear-resistant, insulating light-curing coatings of Examples 1 to 5, the liquid film was irradiated under 405 nm ultraviolet light for 10 seconds to obtain a coating. The coating performance comparison is shown in Table 1, where the coating thickness detection standard is GB / T13452.2-2008, and the coating breakdown voltage detection standard is GB / T1408.1-2016.

[0073] Table 1. Test results of coating properties formed by high-voltage wear-resistant insulating light-curing coatings in Examples 1 to 5.

[0074] project Example 1 Example 2 Example 3 Example 4 Example 5 coating thickness ～100 ～100 ～100 ～100 ～100 Breakdown voltage 6500V 7000V 9500V 8500V 9000V Coating color transparent transparent transparent White White

[0075] The results in Table 1 show that the breakdown voltages of Examples 3 and 5 are more excellent. Based on Table 1, Examples 3 and 5 are preferably selected and pigments are added to Examples 3 and 5.

[0076] Example 6

[0077] A method for preparing a high-voltage wear-resistant insulating light-curing coating is the same as the preparation steps of Example 3, except that 10 parts of powder blue pigment are further added, comprising the following steps:

[0078] S1. Weigh the raw materials according to the following weight parts: 100 parts of sulfonated bisphenol A epoxy acrylate, 60 parts of modified polyurethane acrylate, 5 parts of photoinitiator, and 10 parts of powder blue pigment, and set aside; except for sulfonated bisphenol A epoxy acrylate, the remaining components are purchased from the market.

[0079] S2. Preparation of sulfonated bisphenol A epoxy acrylate: bisphenol A epoxy resin and hydroquinone were added into a container at a mass ratio of 200:1, and stirred and mixed at 90° C. under a nitrogen atmosphere to obtain a resin system.

[0080] 75 parts of a 50 wt% aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and 2 parts of triphenylphosphine were added to the resin system, and the mixture was stirred at 90° C. for 6 h. Water was removed by rotary evaporation to obtain sulfonated bisphenol A epoxy acrylate.

[0081] S3. Preparation of high-voltage and wear-resistant insulating photocuring coating: sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate, photoinitiator and powder blue pigment are added into a container, mechanically stirred for 6 hours to obtain a mixed resin, and then the mixed resin is placed in a 55°C oven for heat treatment for 6 hours, further mixed evenly and defoamed to obtain a high-voltage and wear-resistant insulating photocuring coating.

[0082] The high-pressure wear-resistant insulating light-curing coating of Example 6 was sprayed to demonstrate the spraying performance: the high-pressure wear-resistant insulating light-curing coating was sprayed onto an aluminum plate with a size of 100 mm × 50 mm × 1 mm using an air spray gun. The initial pressure of the spray gun was 6 kg, and after the gun was opened, it stabilized at 3 to 4 kg. The aluminum plate was bent into different shapes, with attention paid to its edge coverage, to demonstrate the easy spraying properties of the high-pressure wear-resistant insulating light-curing coating. Figure 1 As shown, the results show that the high-pressure wear-resistant insulating light-curing coating of Example 6 can be cured and formed on aluminum plates of various shapes (including flat surfaces, curved surfaces, and right-angled surfaces). Through optical microscopy, the sprayed coating has a uniform thickness and can also cover the edge range well.

[0083] According to the coating lap shear test standard: ASTM D1002, the adhesion ability of high-voltage wear-resistant insulating light-curing coatings to aluminum substrates was studied through the lap shear test of adhesive materials. The test method is as follows: according to the requirements of the standard, two rectangular aluminum plates are prepared and glued together at the overlap area with an overlap length of 12.5mm; then, a universal mechanical testing machine is used to record the maximum load at which failure occurs at a tensile force of 1.3mm / min. Figure 2 As shown, the results show that after the lap shear test of the bonding material, the failure mode is adhesive fracture failure, while the coating formed by the high-voltage wear-resistant insulating light-curing coating has no change, indicating that the coating has good adhesion.

[0084] According to the coating cross crush adhesion test standard: ASTMD3359, the cross crush adhesion test is used to evaluate the adhesion performance of the coating formed by the high-pressure wear-resistant insulating light-curing paint on the aluminum plate substrate. The specific operation is as follows: Use a grid cutter to scratch a cross-cut pattern on the surface of the coating formed by the high-pressure wear-resistant insulating light-curing paint, then use tape to stick to the cut area and tear it off quickly, and finally evaluate the adhesion by observing the peeling of the cut area. The grade is evaluated according to the size of the peeling area, usually from 0 (best) to 5 (worst). Figure 3 As shown, after the cross-crushing adhesion test, the cut is almost completely smooth, there is no peeling in the cut area, and the adhesion level reaches level 0.

[0085] Example 7

[0086] A method for preparing a high-voltage wear-resistant insulating light-curing coating is the same as the preparation steps of Example 3, except that 10 parts of red pigment are further added, comprising the following steps:

[0087] S1. Weigh the raw materials according to the following weight parts: 100 parts of sulfonated bisphenol A epoxy acrylate, 60 parts of modified polyurethane acrylate, 5 parts of photoinitiator, and 10 parts of powder blue pigment, and set aside; except for sulfonated bisphenol A epoxy acrylate, the remaining components are purchased from the market.

[0088] S2. Preparation of sulfonated bisphenol A epoxy acrylate: bisphenol A epoxy resin and hydroquinone were added into a container at a mass ratio of 200:1, and stirred and mixed at 90° C. under a nitrogen atmosphere to obtain a resin system.

[0089] 75 parts of a 50 wt% aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and 2 parts of triphenylphosphine were added to the resin system, and the mixture was stirred at 90° C. for 6 h. Water was removed by rotary evaporation to obtain sulfonated bisphenol A epoxy acrylate.

[0090] S3. Preparation of high-voltage and wear-resistant insulating photocuring coating: sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate, photoinitiator and red pigment are added into a container, mechanically stirred for 6 hours to obtain a mixed resin, and then the mixed resin is placed in a 55°C oven for heat treatment for 6 hours, further mixed evenly and defoamed to obtain a high-voltage and wear-resistant insulating photocuring coating.

[0091] Example 8

[0092] A method for preparing a high-voltage wear-resistant insulating light-curing coating is the same as the preparation steps of Example 5, except that 10 parts of powder blue pigment is further added, comprising the following steps:

[0093] S1. Weigh the following raw materials according to weight: 100 parts of sulfonated bisphenol A epoxy acrylate, 60 parts of modified polyurethane acrylate, 5 parts of photoinitiator, and 10 parts of aluminum oxide with a particle size of 500 nm. Except for the sulfonated bisphenol A epoxy acrylate, all other components were purchased commercially.

[0094] S2. Preparation of sulfonated bisphenol A epoxy acrylate: bisphenol A epoxy resin and hydroquinone were added into a container at a mass ratio of 200:1, and stirred and mixed at 90° C. under a nitrogen atmosphere to obtain a resin system.

[0095] 75 parts of a 50 wt% aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and 2 parts of triphenylphosphine were added to the resin system, and the mixture was stirred at 90° C. for 6 h. Water was removed by rotary evaporation to obtain sulfonated bisphenol A epoxy acrylate.

[0096] S3. Preparation of high-voltage and wear-resistant insulating photocuring coating: add sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate and photoinitiator into a container, stir mechanically for 6 hours to obtain a mixed resin, then place the mixed resin into an oven at 55°C for heat treatment for 8 hours, add filler aluminum oxide and powder blue pigment, continue mixing and stirring for 1 hour to obtain a mixed product, further mix evenly and remove bubbles to obtain a high-voltage and wear-resistant insulating photocuring coating.

[0097] Example 9

[0098] A method for preparing a high-voltage wear-resistant insulating light-curing coating is the same as the preparation steps of Example 5, except that 10 parts of red pigment are further added, comprising the following steps:

[0099] S1. Weigh the following raw materials according to weight: 100 parts of sulfonated bisphenol A epoxy acrylate, 60 parts of modified polyurethane acrylate, 5 parts of photoinitiator, and 10 parts of aluminum oxide with a particle size of 500 nm. Except for the sulfonated bisphenol A epoxy acrylate, all other components were purchased commercially.

[0100] S2. Preparation of sulfonated bisphenol A epoxy acrylate: bisphenol A epoxy resin and hydroquinone were added into a container at a mass ratio of 200:1, and stirred and mixed at 90° C. under a nitrogen atmosphere to obtain a resin system.

[0101] 75 parts of a 50 wt% aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and 2 parts of triphenylphosphine were added to the resin system, and the mixture was stirred at 90° C. for 6 h. Water was removed by rotary evaporation to obtain sulfonated bisphenol A epoxy acrylate.

[0102] S3. Preparation of high-voltage and wear-resistant insulating photocuring coating: add sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate and photoinitiator into a container, stir mechanically for 6 hours to obtain a mixed resin, then place the mixed resin into an oven at 55°C for heat treatment for 8 hours, add filler aluminum oxide and red pigment, continue mixing and stirring for 1 hour to obtain a mixed product, further mix evenly and remove bubbles to obtain a high-voltage and wear-resistant insulating photocuring coating.

[0103] The high-voltage wear-resistant insulating light-curing coatings of Examples 6 to 9 were used to form coatings. The method was as follows: forming liquid films of the high-voltage wear-resistant insulating light-curing coatings of Examples 6 to 9, respectively, and irradiating them under 405 nm ultraviolet light for 10 seconds to obtain coatings. A preliminary comparison of the properties of the coatings is shown in Table 2, wherein the viscosity of the coatings was tested using a viscometer:

[0104] Table 2 Test results of coating properties formed by high-voltage wear-resistant insulating light-curing coatings of Examples 6 to 9

[0105] project Example 6 Example 7 Example 8 Example 9 coating thickness 70~80μm 70~80μm 70~80μm 70~80μm Breakdown voltage 8440V 8130V 7650V 7660V Coating color blue red blue red Paint viscosity 9863mPa·s 9271mPa·s 10835mPa·s 12082 mPa·s

[0106] The results in Table 2 show that the breakdown voltage of Example 6 is the highest. Based on Table 2, the high-voltage and wear-resistant insulating light-curing coating of Example 6 is preferably selected.

[0107] The following is an example of the high-pressure wear-resistant insulating light-curing coating of Example 6 to form a coating, and the coating is formed with PET blue film and imported foreign The performance of UV light-curing coatings was compared, and the results are shown in Table 3. The coating thermal conductivity standard is ASTM D5470, and the coating friction and wear test standard is GB / T 1768-79. The friction coefficient and wear conditions are tested by a friction and wear tester. The test parameters are: friction force 10N, reciprocating speed 4mm / s, frequency 0.5Hz, and friction time 15min. The Shore hardness is tested using a Shore D durometer, and the thermal conductivity is tested using a laser thermal conductivity meter.

[0108] Table 3 Comparison of high-pressure wear-resistant insulating light-curing coatings and commercial battery shell insulating materials in Example 6

[0109]

[0110]

[0111] The results in Table 3 show that the breakdown performance of the high-voltage wear-resistant insulating light-curing coating of Example 6 is better than that of the PET blue film and UV light curing coating; the viscosity of the high pressure wear resistant insulating light curing coating of Example 6 is also UV coating viscosity is similar; and the wear resistance and hardness are much better than PET blue film and UV light curing coating.

[0112] Figure 4 The results show that the high-voltage wear-resistant insulating light-curing coating of Example 6 has the smallest friction coefficient and the strongest wear resistance.

[0113] Figure 5 The results show that the high-voltage wear-resistant insulating light-curing coating of Example 6 has good wear resistance. In the same friction and wear test, the surface of the high-voltage wear-resistant insulating light-curing coating of Example 6 has no wear. Both the UV coating and the PET blue film showed obvious wear.

[0114] Example 10

[0115] A method for preparing a high-voltage wear-resistant insulating light-curing coating comprises the following steps:

[0116] S1. Weigh the raw materials according to the following weight parts: 75 parts of sulfonated bisphenol A epoxy acrylate, 100 parts of modified polyurethane acrylate, and 3 parts of photoinitiator, and set aside; except for sulfonated bisphenol A epoxy acrylate, the remaining components are purchased from the market.

[0117] S2. Preparation of sulfonated bisphenol A epoxy acrylate: bisphenol A epoxy resin and hydroquinone were added into a container at a mass ratio of 150:0.5, and stirred and mixed at 75° C. under a nitrogen atmosphere to obtain a resin system.

[0118] 100 parts of a 50 wt% aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and 2 parts of triphenylphosphine were added to the resin system, and the mixture was stirred at 75° C. for 4 h. Water was removed by rotary evaporation to obtain sulfonated bisphenol A epoxy acrylate.

[0119] S3. Preparation of high-voltage and wear-resistant insulating photocuring coating: sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate and photoinitiator are added into a container, mechanically stirred for 6 hours to obtain a mixed resin, and then the mixed resin is placed in a 50°C oven for heat treatment for 5 hours, further mixed evenly and defoamed to obtain a high-voltage and wear-resistant insulating photocuring coating.

[0120] Example 11

[0121] A method for preparing a high-voltage wear-resistant insulating light-curing coating comprises the following steps:

[0122] S1. Weigh the raw materials according to the following weight parts: 50 parts of sulfonated bisphenol A epoxy acrylate, 20 parts of modified polyurethane acrylate, and 1 part of photoinitiator, and set aside; except for sulfonated bisphenol A epoxy acrylate, the remaining components are purchased from the market.

[0123] S2. Preparation of sulfonated bisphenol A epoxy acrylate: bisphenol A epoxy resin and hydroquinone were added into a container at a mass ratio of 250:1.5, and stirred and mixed at 60° C. under a nitrogen atmosphere to obtain a resin system.

[0124] 50 parts of a 50 wt% aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and 2 parts of triphenylphosphine were added to the resin system, and the mixture was stirred at 60° C. for 8 h. Water was removed by rotary evaporation to obtain sulfonated bisphenol A epoxy acrylate.

[0125] S3. Preparation of high-voltage and wear-resistant insulating photocuring coating: sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate and photoinitiator are added into a container, mechanically stirred for 6 hours to obtain a mixed resin, and then the mixed resin is placed in a 60°C oven for heat treatment for 3 hours, further mixed evenly and defoamed to obtain a high-voltage and wear-resistant insulating photocuring coating.

[0126] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

[0127] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for preparing a high-voltage wear-resistant insulating light-curing coating, characterized in that: The steps include: Under an inert atmosphere, bisphenol A epoxy resin and an inhibitor, hydroquinone, are mixed to obtain a resin system; an aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid and a catalyst are added to the resin system to undergo an epoxy ring-opening reaction, whereby the epoxy groups on the main chain of the bisphenol A epoxy resin are attacked by the sulfonic acid groups of the 2-acrylamide-2-methylpropanesulfonic acid to form sulfonate ester bonds and hydroxyl groups; after completion of the reaction, water is separated to obtain sulfonated bisphenol A epoxy acrylate; Weigh the following raw materials according to the following weight parts: 50 to 100 parts of sulfonated bisphenol A epoxy acrylate, 20 to 100 parts of modified polyurethane acrylate, and 1 to 5 parts of photoinitiator; Wherein, the modified polyurethane acrylate is bifunctional silicone grafted polyurethane acrylate; Sulfonated bisphenol A epoxy acrylate, modified polyurethane acrylate and a photoinitiator are uniformly mixed to obtain a high-voltage and wear-resistant insulating light-curing coating.

2. The method for preparing a high-voltage wear-resistant insulating light-curing coating according to claim 1, characterized in that: The mass ratio of bisphenol A epoxy resin to hydroquinone is 150-250:0.5-1.

5.

3. The method for preparing a high-voltage wear-resistant insulating light-curing coating according to claim 1, characterized in that: The mass ratio of bisphenol A epoxy resin to 2-acrylamide-2-methylpropanesulfonic acid is 150-250:50-100.

4. The method for preparing a high-voltage wear-resistant insulating light-curing coating according to claim 1, characterized in that: The conditions for the epoxy ring-opening reaction are: heating at 60°C to 90°C for 4h to 8h.

5. The method for preparing a high-voltage wear-resistant insulating light-curing coating according to claim 1, characterized in that: The high-voltage wear-resistant insulating light-curing coating further comprises 0 to 60 parts of a reactive diluent, which is selected from one or more of polyethylene glycol diacrylate, tripropylene glycol diacrylate, and 1,6-hexanediol diacrylate.

6. The method for preparing a high-voltage wear-resistant insulating light-curing coating according to claim 1, characterized in that: The high-voltage wear-resistant insulating light-curing coating further comprises 0 to 30 parts of wear-resistant filler, which is selected from one or more of aluminum oxide, zinc oxide, silicon dioxide, zirconium oxide and yttrium oxide; and the size of the wear-resistant filler is 50 nm to 10 μm.

7. The method for preparing a high-voltage wear-resistant insulating light-curing coating according to claim 1, characterized in that: The high-voltage wear-resistant insulating light-curing paint further comprises 5 to 15 parts of pigment, which is a photosensitive oil print.

8. A high-voltage, wear-resistant, insulating light-curing coating prepared by the preparation method according to any one of claims 1 to 7.

9. A power battery shell coating, characterized in that: The high-voltage wear-resistant insulating light-curing coating is prepared by subjecting the coating to free radical polymerization under ultraviolet light.

10. The power battery shell coating according to claim 9, characterized in that: The power battery shell coating is prepared according to the following steps: after applying the high-voltage wear-resistant insulating light-curing coating into a liquid film, it is irradiated under 405nm ultraviolet light for 1s to 10s to carry out a free radical polymerization reaction to obtain the power battery shell coating.

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