Fluorine-containing polymer scratch-proof composition as well as preparation method and application thereof

Abstract

The invention discloses a fluorine-containing polymer scratch-proof composition as well as a preparation method and application thereof, and relates to the technical field of battery preparation. The fluorine-containing polymer scratch-proof composition is prepared from the following components: perfluoroalkyl ethyl acrylate, octadecyl acrylate, hydroxyethyl methylacrylate and butyl acrylate. The fluorine-containing polymer scratch-proof composition has the advantages of low surface tension, good mobility, high temperature resistance, good compatibility, environmental friendliness, low cost, no stickiness, no influence on other properties and durability of the material and easiness in processing.

Description

Technical Field

[0001] The present invention relates to the technical field of battery preparation, and more particularly, to a fluoropolymer anti-scratch composition, a preparation method thereof, and an application thereof. Background Art

[0002] In the field of battery production, the manufacture of electrode sheets is one of the key links, and its quality directly affects the performance and service life of the battery. During the electrode sheet cutting process, the PP drawing film conveyor belt, as a core component, is responsible for accurately transporting the electrode sheet to the cutting position. However, due to the repeated pressure of the die-cutting knife on the conveyor belt during the cutting process, knife marks of varying depths will inevitably appear on the surface of the conveyor belt. These knife marks not only affect the appearance of the conveyor belt, but more importantly, they will transmit pressure to the thin electrode sheet, resulting in indentations on the electrode sheet during die-cutting, thereby affecting the quality and consistency of the product. Therefore, protecting the PP drawing film conveyor belt from scratches is an important issue for improving battery production efficiency and product quality.

[0003] Existing anti-scratch technologies mainly rely on the application of traditional anti-scratch agents. These anti-scratch agents can reduce the generation of scratches on the conveyor belt surface to a certain extent, thereby protecting the integrity of the conveyor belt. However, traditional anti-scratch agents have many limitations in practical applications.

[0004] Firstly, insufficient heat resistance is a major defect of traditional anti-scratch agents. During battery production, especially in high-temperature environments, traditional anti-scratch agents are prone to decomposition or migration, resulting in a significant decline in their performance and being unable to provide continuous and effective protection for the conveyor belt. Secondly, environmental protection issues are becoming increasingly prominent. Many traditional anti-scratch agents contain components harmful to the environment, which runs counter to the strict environmental protection requirements of modern industry and does not conform to the trend of sustainable development. In addition, the production cost of traditional anti-scratch agents is relatively high, and when applied on a large scale, their maintenance and replacement costs cannot be ignored, which increases the operating burden of enterprises. Finally, traditional anti-scratch agents perform poorly in terms of water resistance, alkali resistance, and solvent resistance, limiting their application in diverse working environments, especially in battery production, where this limitation is particularly obvious.

[0005] In summary, existing anti-scratch technologies have various defects in the application in the field of battery production. Insufficient heat resistance causes traditional anti-scratch agents to be unable to continuously function in high-temperature environments; environmental protection issues make it difficult for them to meet increasingly strict regulatory requirements; high costs and frequent maintenance and replacement increase the operating burden of enterprises; while performance limitations restrict their applicability in complex working environments. These defects not only affect the service life of the conveyor belt, but also have a negative impact on the quality and efficiency of battery production, and urgently need to be solved through technological innovation.

[0006] In view of this, the present invention is specifically proposed. Summary of the Invention

[0007] The object of the present invention is to provide a fluoropolymer anti-scratch composition, a preparation method and an application thereof. The fluoropolymer anti-scratch composition has the advantages of low surface tension, good migration property, high heat resistance, good compatibility, environmental protection, low cost, non-stickiness, no influence on other properties of materials, durability and easy processing.

[0008] In order to achieve the above object of the present invention, the following technical solutions are specifically adopted: In the first aspect, the present invention provides a fluoropolymer anti-scratch composition, which comprises the following components: Perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate and butyl acrylate.

[0009] In an alternative embodiment, the fluoropolymer anti-scratch composition comprises the following components in parts by weight: Perfluoroalkyl ethyl acrylate, 30 parts to 50 parts; Octadecyl acrylate, 10 parts to 30 parts; 2-hydroxyethyl methacrylate, 5 parts to 10 parts; Butyl acrylate, 5 parts to 20 parts.

[0010] In the second aspect, the present invention provides a preparation method of a fluoropolymer anti-scratch composition, comprising: Adding perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate and butyl acrylate into an organic solvent to obtain a mixture; Adding an initiator to the mixture, and causing the perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate and butyl acrylate in the mixture to undergo a polymerization reaction under the action of free radicals generated by the initiator to obtain a fluoropolymer anti-scratch composition.

[0011] In an alternative embodiment, the organic solvent comprises methyl isobutyl ketone; In an alternative embodiment, the initiator comprises azobisisobutyronitrile.

[0012] In an alternative embodiment, the organic solvent accounts for 20% to 50% of the total weight; In an alternative embodiment, the initiator accounts for 0.5% to 1.2% of the total weight; In an alternative embodiment, the initiator accounts for 0.8% to 1.0% of the total weight; In an alternative embodiment, the addition method of the initiator is to add it in batches, and the interval time between adding different batches of the initiator is 15 minutes to 30 minutes; In an alternative embodiment, the number of batches of the initiator added is at least two; In an alternative embodiment, the preparation process of the mixture is carried out under a protective gas.

[0013] In an alternative embodiment, the perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate and butyl acrylate in the mixture are polymerized under the action of free radicals generated by the initiator, including: Performing heat reaction treatment on the mixture added with the initiator in the initiation polymerization stage and the acceleration polymerization stage in sequence; Wherein, the temperature of the acceleration polymerization stage is not less than that of the initiation polymerization stage.

[0014] In an alternative embodiment, the temperature of the acceleration polymerization stage is greater than that of the initiation polymerization stage.

[0015] In an alternative embodiment, the initiation polymerization stage is: Controlling the mixture added with the initiator to react at a temperature of 70 °C to 75 °C for 5 hours to 6.5 hours.

[0016] In an alternative embodiment, the initiation polymerization stage is: Controlling the mixture added with the initiator to react at a temperature of 75 °C for 6.5 hours.

[0017] In an alternative embodiment, the acceleration polymerization stage is: Controlling the mixture added with the initiator to be heated to a temperature of 80 °C and react for 2 hours.

[0018] In a third aspect, the present invention provides a method for cutting a pole piece, including: Coating the surface of the conveyor belt of the cutting device with the fluoropolymer anti-scratch composition according to any one of the foregoing embodiments, and performing pole piece cutting through the cutting device.

[0019] In a fourth aspect, the present invention provides an application of the fluoropolymer anti-scratch composition in the preparation of a product for treating the surface of the conveyor belt in a cutting device.

[0020] Compared with the prior art, the beneficial effects of the present invention are: The present application provides a fluoropolymer anti-scratch composition, its preparation method and application. Among them, the fluoropolymer anti-scratch composition is composed of perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate and butyl acrylate, which significantly improves the anti-scratch performance and the durability of the material. Perfluoroalkyl ethyl acrylate endows the composition with excellent anti-scratch property, abrasion resistance and chemical stability. Octadecyl acrylate and butyl acrylate improve the flexibility and adhesion of the polymer, enhancing the bonding force with the substrate. 2-hydroxyethyl methacrylate improves the durability and surface stability of the coating, making the composition exhibit excellent protective performance under environments such as high temperature and corrosion, applicable to various surface protection fields, and improving the service life and anti-aging ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic flow chart of the preparation method of the fluoropolymer anti-scratch composition in the present application; Figure 2 It is a schematic flow chart of the preparation method of the fluoropolymer anti-scratch composition in the present application.

[0023] Reference numerals: 100 - cutting equipment; 1 - die-cutting knife; 2 - conveyor belt; 3 - fluoropolymer anti-scratch composition coating. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will describe the embodiments of the present invention in detail in conjunction with the examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. For those conditions not specified in the examples, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. Those reagents or instruments not specified in the manufacturer are all conventional products that can be obtained through commercial purchase.

[0025] In the embodiments of the present application, a fluoropolymer anti-scratch composition is provided, and the fluoropolymer anti-scratch composition includes the following components: Perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate and butyl acrylate.

[0026] In the fluoropolymer anti-scratch composition, these chemical substances play different roles respectively.

[0027] Perfluoroalkyl ethyl acrylate, namely the PFEMA unit in the composition, C3F7CH2CH2COOCH3, FEMA provides the core properties of the scratch-resistant agent, and its fluorine-containing structure endows the material with low surface energy and excellent chemical stability. It belongs to fluorine-containing compounds and has strong chemical stability, corrosion resistance and low friction characteristics. Its main function is to provide excellent scratch resistance and abrasion resistance, so that the composition is not easily damaged when in surface contact friction. In addition, the fluorinated alkyl chain segment also has water resistance and oil repellency, enhancing the anti-pollution ability of the surface and contributing to improving the high-temperature resistance of the composition.

[0028] Octadecyl acrylate, namely the ODA unit in the composition, C18H35CH2CH2COOCH3, the addition of ODA enhances the adhesion of the scratch-resistant agent to the substrate and improves the abrasion resistance of the product. This substance is a compound formed by octadecyl (C18) and acrylate monomer, and its main function is to act as a plasticizer to improve the flexibility of the polymer. It can improve the processability and adhesion of the composition and contribute to enhancing the bonding force with the substrate to prevent the coating from peeling off, thus improving the protection effect.

[0029] 2-Hydroxyethyl methacrylate, namely the HEMA unit in the composition, CH2CH(OH)COOCH3, the introduction of HEMA helps to improve the flexibility and impact resistance of the scratch-resistant agent, making it more suitable for various working environments. This substance has the characteristics of hydroxyl (-OH) and acrylic acid, which can increase the hydrophilicity of the material. At the same time, due to the hydroxyl group in its structure, it helps to introduce cross-linking points in the polymer. This makes the composition have higher durability and stability, especially in the use environment, it can effectively resist aging and thermal oxidation.

[0030] Butyl acrylate, namely the BA unit in the composition, CH2CH(CH3)COOCH3, adjusting the proportion of BA can optimize the rheological properties of the scratch-resistant agent to ensure its uniform distribution during application. This substance is a monomer used to improve the fluidity and flexibility of the polymer and enhance the compatibility with other components. In this composition, butyl acrylate is to improve the processability of the material and the toughness of the coating, so that the scratch-resistant composition can better adapt to surface morphology changes during use.

[0031] In summary, perfluoroalkyl ethyl acrylate provides strong scratch resistance, abrasion resistance and anti-pollution ability. Octadecyl acrylate, as a plasticizer, improves the flexibility and adhesion of the polymer. 2-Hydroxyethyl methacrylate enhances the durability and anti-aging ability of the material. Butyl acrylate improves the flexibility and processability of the material. The combination of these components endows the scratch-resistant composition with excellent performance in different applications, such as surface protection and durability.

[0032] The novel fluoropolymer anti-scratch composition provided by this embodiment reduces scratches and adhesion through low surface tension, protecting the conveyor belt from damage; relying on the high heat resistance of the fluoropolymer, it ensures stable performance in high-temperature environments and is suitable for various industrial scenarios; at the same time, this anti-scratch agent has good compatibility with the PP drawn film conveyor belt material and does not affect other properties of the conveyor belt. In addition, the present invention uses environmentally friendly materials, reducing the impact on the environment, meeting the environmental protection requirements of modern industry, and having a low cost during production and application, which helps to reduce the operating costs of enterprises. More importantly, the novel anti-scratch agent has excellent durability, can maintain its performance during long-term use, and reduces the frequency of maintenance and replacement.

[0033] In summary, the fluoropolymer anti-scratch composition in this embodiment has significant advantages in practical applications. It not only has a wide application prospect in the above industries, but also its environmental friendliness, low cost and good compatibility make it an ideal substitute for traditional anti-scratch agents. With the increasingly strict environmental protection regulations and the increasing demand for cost control, the fluoropolymer anti-scratch composition will occupy an important position in the market and can meet the needs of modern industry for efficient, environmentally friendly and economical anti-scratch solutions.

[0034] In some embodiments, the fluoropolymer anti-scratch composition includes the following components in weight fractions: Perfluoroalkyl ethyl acrylate, 30 parts to 50 parts; for example, it can be 30 parts, 40 parts, 50 parts, etc.

[0035] Octadecyl acrylate, 10 parts to 30 parts; for example, it can be 10 parts, 20 parts, 30 parts, etc.

[0036] 2-Hydroxyethyl methacrylate, 5 parts to 10 parts; for example, it can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.

[0037] Butyl acrylate, 5 parts to 20 parts. For example, it can be 5 parts, 8 parts, 10 parts, 15 parts, 20 parts, etc.

[0038] For example, assuming the proportion of PFEMA is 40 parts, the proportion of ODA is 20 parts, the proportion of HEMA is 15 parts, and the proportion of BA is 25 parts, the simplified structure of the copolymer can be expressed as: (C3F7CH2CH2COOCH3)4(C18H35CH2CH2COOCH3)2(CH2CH(OH)COOCH3)1.5(CH2CH(CH3)COOCH3)2.5.

[0039] Reference Figure 1 , in the embodiments of the present application, a preparation method of a fluoropolymer anti-scratch composition is provided, including: Step S1, perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate and butyl acrylate are added to an organic solvent to obtain a mixture.

[0040] In this step, the four monomers are mixed with the organic solvent to form a homogeneous mixture, preparing for the subsequent polymerization reaction. After accurately weighing perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate and butyl acrylate according to a certain weight ratio, they are added to the organic solvent. The choice of organic solvent has an important influence on the uniformity of the mixture and the progress of the subsequent polymerization reaction.

[0041] Finally, a homogeneous mixture is obtained, in which each monomer and the solvent are fully mixed, providing a suitable reaction medium for the subsequent polymerization reaction.

[0042] In the mixture, the organic solvent can evenly disperse each monomer, avoiding monomer aggregation, thus ensuring the uniform progress of the polymerization reaction. The presence of the organic solvent can adjust the reaction rate, making the reaction more controllable and avoiding problems caused by overly violent reactions. The preparation process of the mixture is relatively simple, easy to operate and control. At room temperature, the weighed monomers are sequentially added to the organic solvent and stirred evenly. The stirring method can be mechanical stirring, and the stirring speed is adjusted according to the properties of the solvent and the monomers, generally controlled at a medium speed to ensure uniform mixing and no excessive bubbles are introduced.

[0043] In some embodiments, the organic solvent includes methyl isobutyl ketone.

[0044] In some preferred embodiments, the organic solvent accounts for 20% - 50% of the total weight; Step S2, an initiator is added to the mixture, and perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate and butyl acrylate in the mixture undergo a polymerization reaction under the action of free radicals generated by the initiator to obtain a fluoropolymer anti-scratch composition.

[0045] In this step, the monomers in the mixture are induced to undergo a polymerization reaction by the initiator to generate a fluoropolymer anti-scratch composition.

[0046] Specifically, an initiator (such as azobisisobutyronitrile) can be added to the mixture, and then the mixture is placed under certain reaction conditions (such as temperature, time, etc.) to make the monomers undergo a polymerization reaction under the action of free radicals generated by the initiator. The addition amount of the initiator needs to be optimized according to the total amount of the monomers and the reaction conditions to ensure the smooth progress of the reaction and the performance of the product.

[0047] After the polymerization reaction, the monomers in the mixture are converted into a fluoropolymer anti-scratch composition, which has excellent properties such as low surface tension, high temperature resistance, and good compatibility.

[0048] In this step, the initiator can efficiently initiate the polymerization of monomers, enabling the reaction to be completed in a relatively short time and improving the production efficiency.

[0049] The fluoropolymer anti-scratch composition produced through the polymerization reaction has excellent properties such as low surface tension, high heat resistance, and good compatibility, and can meet the requirements of different industrial applications. By controlling the addition amount of the initiator and the reaction conditions, the progress of the polymerization reaction can be precisely controlled, thereby obtaining a product with stable performance.

[0050] In some embodiments, the initiator includes azobisisobutyronitrile.

[0051] In some embodiments, the initiator accounts for 0.5% - 1.2% of the total weight; for example, it can be 0.5%, 0.8%, 1.0%, 1.2%, etc.

[0052] In some embodiments, the initiator accounts for 0.8% - 1.0% of the total weight; for example, it can be 0.8%, 0.9%, 1.0%, etc.

[0053] In some embodiments, the addition method of the initiator is to add it in batches, and the interval time between adding different batches of the initiator is 15 minutes - 30 minutes; for example, it can be 15 minutes, 20 minutes, 25 minutes, 30 minutes, etc.

[0054] In some embodiments, the number of batches of adding the initiator is at least two; For example, it can be added in two batches, 60% in the first batch and 40% added in the second batch, with an interval time of 15 - 30 minutes, such as 30 minutes.

[0055] It should be noted that the decomposition temperature of the initiator in this embodiment is ~60°C - 70°C, which is suitable for the reaction conditions of 75°C - 85°C during the preparation process, is compatible with the current solvent system, has a moderate decomposition rate, stable radical release, a narrow molecular weight distribution, and few residues (generating nitrogen and isobutyronitrile), does not affect the chemical stability of the anti-scratch agent, meets the patent environmental protection requirements, and is highly compatible with processes such as nitrogen protection and temperature control.

[0056] It should be noted that the selection of the initiator has an important impact on the rate of the polymerization reaction and the performance of the product. The azobisisobutyronitrile used in this embodiment has high initiation efficiency.

[0057] It should be noted that within a suitable temperature and time range, temperature and time have a crucial impact on the reaction process. Temperature can not only enable the fusion of various materials to achieve a balanced reaction rate and product stability, but also ensure that the monomer conversion rate meets the standard, while avoiding increased energy consumption or by-product formation due to overreaction. In terms of time, without temperature rise compensation, the reaction will be difficult to proceed completely; when the reaction is complete, its performance is close to that of the product under standard conditions. If you want to shorten the reaction time, it is necessary to optimize the temperature matching to avoid differences between batches.

[0058] The adjustment of parameters in different embodiments aims to optimize performance (such as improving the uniformity of molecular weight) or adapt to changes in raw material ratios, which also reflects the flexibility of the process. For example, the reasonable range can include the following: Temperature (adjusted according to performance requirements): Initial temperature: 70°C - 75°C, duration: 6 - 7 hours; Heating stage: 80°C - 85°C, duration: 1.5 hours - 2 hours (the time needs to be adjusted in coordination with the temperature).

[0059] In some embodiments, the preparation process of the mixture is carried out under a protective gas.

[0060] As mentioned above, the protective gas can be nitrogen. Among them, nitrogen protection helps to prevent the oxidation of raw materials during the polymerization process and ensure product quality.

[0061] Specifically, the initiator can be added to the mixture under nitrogen protection. During the reaction process, the reaction can be made more uniform by stirring and other means.

[0062] In some embodiments, in step S2, the perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate, and butyl acrylate in the mixture undergo a polymerization reaction under the action of free radicals generated by the initiator, including: Step S21, the mixture added with the initiator is sequentially subjected to heat reaction treatment in an initiation polymerization stage and an accelerated polymerization stage; wherein, the temperature in the accelerated polymerization stage is not less than that in the initiation polymerization stage.

[0063] During the polymerization reaction of this technology, the reaction is divided into an initiation polymerization stage and an acceleration polymerization stage, and different-stage heating reactions are carried out respectively. First of all, it is to control the reaction rate of free radical polymerization and prevent the reaction from being too fast or out of control. This method uses free radical polymerization, in which an initiator (such as azobisisobutyronitrile, AIBN) generates free radicals after thermal decomposition, initiating the polymerization reaction of monomers. The initial temperature of the initiation polymerization stage is relatively low (for example, 75 °C), and its function is to slowly initiate the generation of free radicals, preventing a large number of free radicals from being generated in a short time, resulting in too fast reaction rate, excessive heat release, and even possible overheating or gelation of the polymerization system. As the reaction progresses, the free radical concentration gradually increases and the monomers are gradually consumed. At this time, if the temperature is not increased, it may lead to a decrease in the free radical concentration, affecting the polymerization rate and the final degree of polymerization.

[0064] Secondly, to increase the degree of polymerization and optimize the molecular structure of the polymer. In the acceleration polymerization stage, by raising the temperature (for example, 80 °C or higher), the activity of free radicals can be increased, the polymerization rate of monomers can be accelerated, and the molecular weight of the final polymer can be increased; it can promote the complete polymerization of unreacted monomers, improve the conversion rate of the product, reduce residual monomers, and improve product performance. This process can ensure that the polymer forms a complete long-chain structure, enhancing the wear resistance, adhesion, and stability of the material, making the scratch resistance of the final product better.

[0065] Thirdly, to reduce side reactions and improve product purity. In the initiation polymerization stage, controlling the temperature can reduce unnecessary side reactions, such as self-termination reactions (that is, premature combination between free radicals, resulting in the formation of oligomers, affecting the performance of the final polymer), or crosslinking or gelation (if the free radical concentration is too high, it may cause polymer crosslinking, affecting solubility and rheological properties). In the acceleration polymerization stage, by appropriately raising the temperature, the reaction rate can be accelerated, reaction residues can be reduced, and at the same time, chain transfer or degradation caused by long-term low-temperature reactions can be prevented.

[0066] In addition, to optimize product performance and improve durability. By carrying out staged heating reactions, the uniformity of the polymer can be improved, the problem of too wide molecular weight distribution can be reduced, and the coating consistency can be improved. By moderately raising the temperature, the polymer chain segments are arranged more regularly, enhancing the wear resistance, adhesion, and chemical stability of the scratch-resistant agent. Avoid product defects caused by one-time high-temperature reactions, such as bubbles and uneven local crosslinking.

[0067] As mentioned above, the initiation polymerization stage refers to the initial stage of the polymerization reaction. In this stage, the main goal is to activate the initiator, generate free radicals, and initiate the polymerization of monomers.

[0068] In the initiation polymerization stage, the generation of free radicals and the initial chain growth mainly occur. Usually, initiators such as azobisisobutyronitrile (AIBN) are used in this process. Under specific temperature conditions, AIBN decomposes to generate free radicals (-CN), and these free radicals react with monomers to form active polymer chains. The generated free radicals will attack monomers such as perfluoroalkyl ethyl acrylate and octadecyl acrylate, initiate chain growth, and gradually form a preliminary polymer structure. To ensure the stability of the reaction, a relatively low temperature is usually adopted in this stage to prevent the initiator from decomposing too quickly, avoid too high a concentration of free radicals, and thus reduce the risk of side reactions (such as cross-linking and by-product generation). In addition, the low-temperature condition can effectively control the reaction rate, prevent the system from overheating, and avoid local overheating or explosive polymerization caused by intense exotherm. At the same time, in this stage, the preliminary molecular weight growth is mainly completed. The monomers start to polymerize, but the overall degree of polymerization is still relatively low, and the molecular weight needs to be further increased in the subsequent acceleration polymerization stage to ensure that the final polymer has excellent properties.

[0069] As described above, in the acceleration polymerization stage after the initiation polymerization stage, the rate of the polymerization reaction is increased by raising the temperature, the molecular weight of the polymer is increased, and the monomers are made to react as completely as possible.

[0070] The main function of the acceleration polymerization stage is to increase the polymerization rate to ensure that the polymerization reaction proceeds efficiently and fully. In the initiation polymerization stage, due to the relatively low initial concentration of free radicals, the reaction rate is slow. As the polymerization reaction progresses and enters the acceleration polymerization stage, raising the temperature can enhance the activity of free radicals, accelerate the growth of polymer chains, thereby increasing the overall reaction rate, making the remaining monomers react fully, and increasing the conversion rate. At the same time, appropriately raising the temperature helps to form longer polymer chains, increase the molecular weight, and further enhance the abrasion resistance, adhesion, and mechanical properties of the anti-scratch agent. In addition, temperature control is crucial for reducing residual monomers and improving the coating quality. If the temperature is too low, some monomers may not polymerize fully, resulting in unreacted monomers remaining in the product, affecting its environmental friendliness and safety. Moderately raising the temperature can promote the complete polymerization of monomers, reduce residues, improve the purity of the product, and reduce the release of harmful volatile organic compounds (VOCs). At the same time, a higher reaction temperature can also optimize the polymer structure and enhance its durability. The temperature increase in the acceleration polymerization stage not only speeds up the chain growth rate but may also promote the occurrence of cross-linking reactions, thereby improving the thermal stability, chemical resistance, and adhesion of the polymer. This is crucial for enhancing the long-term stability and durability of the anti-scratch agent, enabling it to maintain excellent performance under various environmental conditions.

[0071] The temperature in the acceleration polymerization stage is not less than that in the initiation polymerization stage.

[0072] The temperature in the accelerating polymerization stage is limited to be not less than that in the initiating polymerization stage, mainly to maintain the free radical concentration, prevent the reaction from stagnating, increase the monomer conversion rate, and ensure the continuous progress of the polymerization reaction. During the free radical polymerization process, the free radical concentration gradually decreases. If the temperature decreases, the reaction rate may significantly slow down or even stop, resulting in a decrease in the molecular weight of the polymer, incomplete polymerization of the monomer, an increase in by-products, and thus affecting the wear resistance, scratch resistance, and coating uniformity of the product. Appropriately increasing the temperature to the accelerating polymerization stage (such as 80 °C or higher) can enhance the free radical activity, ensure the growth of polymer chains, accelerate the monomer conversion rate, increase the molecular weight and mechanical properties of the final product, promote cross-linking reactions at the same time, improve the durability and scratch resistance of the coating, and ensure the integrity and chemical stability of the polymer structure. In addition, increasing the temperature can also promote the full polymerization of residual monomers, reduce by-products, improve the environmental performance, adhesion, and service life of the product. Reasonable temperature control can also reduce the generation of oligomers, reduce the influence of side reactions, make the performance of the final product more uniform, and improve the purity and stability of the scratch-resistant coating. The method of heating in stages optimizes the controllability of the process. First, low-temperature initiation ensures uniform start-up of the reaction, avoiding local high-temperature accumulation. Then, heating accelerates polymerization, improving the reaction rate and controllability of the molecular weight, and avoiding operational problems caused by too long production cycles or increased system viscosity. In summary, the technology limitation optimizes the efficiency of free radical polymerization, improves the wear resistance, durability, adhesion, and environmental stability of the product, and ensures the efficient application of the scratch-resistant agent in industrial fields such as automotive, electronics, medical, and photovoltaic.

[0073] In some embodiments, the temperature in the accelerating polymerization stage is greater than that in the initiating polymerization stage.

[0074] In some embodiments, the initiating polymerization stage is as follows: Control the mixture after adding the initiator to react at a temperature of 70 °C to 75 °C for 5 hours to 6.5 hours.

[0075] In some embodiments, the initiating polymerization stage is as follows: Control the mixture after adding the initiator to react at a temperature of 75 °C for 6.5 hours.

[0076] In some embodiments, the accelerating polymerization stage is as follows: Control the mixture after adding the initiator to be heated to a temperature of 80 °C and react for 2 hours.

[0077] In the embodiments of the present application, a method for cutting an electrode sheet is provided, including: (1) Coating (coating) the surface of the conveyor belt of the cutting equipment with the fluoropolymer scratch-resistant composition according to any one of the foregoing embodiments; (2) Cut the electrode sheet using the cutting device.

[0078] The above-mentioned cutting device is usually used for cutting, dividing, and processing materials. In this embodiment, the cutting device is applied to the processing process of the electrode sheet. The electrode sheet refers to a thin film material (such as the positive electrode sheet or negative electrode sheet of a lithium battery) used in fields such as lithium batteries and electronic components. The cutting device consists of the following parts: a cutting tool for precisely cutting the electrode sheet; a conveying system for transporting the electrode sheet from one end to the cutting position; and a conveyor belt that serves as a substrate support during the cutting process and transports the electrode sheet smoothly and continuously under the cutting tool.

[0079] The above-mentioned conveyor belt is a key component in the cutting device. Its main functions may include stably transporting the electrode sheet, that is, ensuring that the electrode sheet remains flat and in the correct position during the cutting process; and withstanding pressure. That is, the conveyor belt may be scratched, indented, or damaged under the pressure of the die-cutting tool, affecting the quality of the electrode sheet and the lifespan of the conveyor belt.

[0080] The coating process (coating) needs to be refined according to material characteristics and application scenarios. In the substrate pretreatment stage, the surface of the conveyor belt must be deeply cleaned (it is recommended to wipe it with isopropyl alcohol or acetone), and activation treatment should be carried out. The activation treatment can be plasma treatment (power 50W - 200W, treatment time 30 - 120 seconds) or chemical etching (treatment with 0.5 - 2% hydrogen fluoride solution for 10 - 30 seconds) to ensure that the surface energy is increased to more than 40 mN / m, thereby enhancing the adhesion of the coating.

[0081] The choice of coating process should be based on specific application scenarios. The following methods can be adopted: (1) Spraying: The spray gun pressure is controlled at 0.3 - 0.6 MPa; (2) Roll coating: The roll speed is set at 5 - 15 m / min; (3) Dip coating: The dipping time is controlled at 30 - 120 seconds; (4) Brush coating: A brush with a hardness of HB grade is selected. The wet film thickness needs to be strictly controlled between 20 - 100 μm to ensure that the dry film thickness is between 1 - 5 μm, meeting the requirements of different application scenarios.

[0082] The coating environment should be maintained under ISO Class 7 dust-free conditions with a temperature of 18 - 25°C and a humidity ≤ 50% RH to prevent uneven solvent volatilization and water vapor interference and ensure the stability of the coating quality.

[0083] The main purpose of the coating process is to evenly coat the surface of the substrate with a coating material to form a wet film. The curing process, on the other hand, transforms the wet film into a dry film with specific properties through physical or chemical changes, thereby endowing the coating with its final functional properties, such as adhesion, abrasion resistance, and corrosion resistance. Therefore, after the coating process, a curing process is required.

[0084] The curing process adopts a gradient program: first, pre-cure at 50 °C for 30 minutes, then perform the main cure at 80 °C for 2 hours, and finally post-cure at 120 °C for 30 minutes. The entire curing process needs to be carried out under nitrogen protection (oxygen content < 100 ppm) to avoid oxidation and yellowing, ensuring the performance and appearance of the coating.

[0085] After curing, quality inspection can be carried out. The quality verification process is crucial, and the following testing methods are required to ensure the coating quality: use an X-ray fluorescence thickness gauge to detect the film thickness deviation, and the deviation range should be controlled within ±0.2 μm; adopt the ASTM D3359 cross-cut method to test the adhesion, and the adhesion grade should reach above 4B; conduct a Taber abrasion test, and the weight loss after 5000 cycles should be less than 2 mg.

[0086] Through the above strict quality control measures, it is ensured that the coating exhibits excellent performance and reliability in various application scenarios.

[0087] For example, during the cutting process, the conveyor belt needs to be coated to enhance its scratch resistance. For example, the coating process is as follows: (1) Surface cleaning: First, clean the surface of the conveyor belt to remove dust, oil, etc., to ensure the adhesion of the scratch-resistant coating to the conveyor belt surface.

[0088] (2) Preparation of the scratch-resistant agent solution: Prepare the coating solution according to the fluoropolymer scratch-resistant composition in the foregoing embodiment. The solution includes perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate, and butyl acrylate, and methyl isobutyl ketone may be used as the solvent.

[0089] (3) Coating methods: Brush coating: Evenly brush the scratch-resistant agent solution on the surface of the conveyor belt.

[0090] Spraying: Use spraying equipment to evenly spray the scratch-resistant agent on the surface of the conveyor belt.

[0091] Dip coating: Immerse the conveyor belt in the scratch-resistant agent solution and then dry it.

[0092] Roll coating: Use roll coating equipment to evenly roll coat the conveyor belt.

[0093] Curing treatment: After coating, heating and curing are usually required to ensure that the scratch-resistant coating forms a firm film on the surface of the conveyor belt. The curing temperature and time depend on the characteristics of the scratch-resistant agent. For example, heating at 80 °C for 2 hours can completely cure the coating.

[0094] Coat the surface of the conveyor belt of the cutting equipment with a fluoropolymer scratch-resistant agent, aiming to significantly improve the wear resistance of the conveyor belt, reduce scratches and damage through its low friction characteristics, high hardness and low surface energy. At the same time, it can effectively disperse the pressure of the die-cutting knife, reduce the indentation on the pole piece during the cutting process, thereby improving the processing accuracy and the quality of the pole piece. In addition, the scratch-resistant coating can extend the service life of the conveyor belt, reduce maintenance and replacement costs, and at the same time reduce the adhesion problem between the pole piece and the conveyor belt, improve production efficiency, and ensure the consistency and high quality of the pole piece products.

[0095] Reference Figure 2 , where Figure 2 A is before coating the fluoropolymer scratch-resistant composition material, the downward pressure mark of the die-cutting knife remains unchanged and can be superimposed after die-cutting; while Figure 2 B is after coating the fluoropolymer scratch-resistant composition material, the downward pressure mark after die-cutting is not obvious.

[0096] In the embodiments of the present application, an application of a fluoropolymer scratch-resistant composition in preparing a product for surface treatment of a conveyor belt in a cutting equipment is provided.

[0097] The following further illustrates the present invention through specific embodiments, but it should be understood that these embodiments are only used for more detailed description and should not be construed as limiting the present invention in any form.

[0098] Example 1 In this embodiment, a fluoropolymer scratch-resistant composition was prepared.

[0099] Experimental method: (1) Raw material ratio: PFEMA 40%, ODA 20%, HEMA 15%, BA 15%. This ratio aims to balance the scratch-resistant performance and cost, while ensuring the durability and environmental adaptability of the scratch-resistant agent.

[0100] (2) Polymerization conditions: Under nitrogen protection, the raw materials were added to methyl isobutyl ketone, azobisisobutyronitrile was added as an initiator, and the reaction was carried out at 75 °C for 6.5 hours, and then the temperature was raised to 80 °C and reacted for 2 hours. Nitrogen protection ensures that there is no oxygen interference during the reaction process, prevents the oxidation of the raw materials, and ensures the smooth progress of the polymerization reaction.

[0101] Thus, a fluoropolymer scratch-resistant composition was prepared.

[0102] Example 2 In this example, a fluoropolymer anti-scratch composition was prepared.

[0103] Experimental method: (1) Raw material ratio: PFEMA 35%, ODA 25%, HEMA 10%, BA 20%. The adjusted ratio aims to improve the wear resistance and durability of the anti-scratch agent while maintaining cost-effectiveness.

[0104] (2) Polymerization conditions: Under nitrogen protection, the raw materials were added to methyl isobutyl ketone, azobisisobutyronitrile was added as an initiator, and the reaction was carried out at 75 °C for 7 hours, and then the temperature was raised to 85 °C and reacted for 1.5 hours. Prolonging the reaction time and increasing the final reaction temperature helps to increase the molecular weight and performance of the polymer.

[0105] Thus, a fluoropolymer anti-scratch composition was prepared.

[0106] Example 3 In this example, a fluoropolymer anti-scratch composition was prepared.

[0107] Experimental method: (1) Raw material ratio: PFEMA 30%, ODA 15%, HEMA 20%, BA 25%. This ratio particularly emphasizes cost-effectiveness while maintaining the necessary anti-scratch performance.

[0108] (2) Polymerization conditions: Under nitrogen protection, the raw materials were added to methyl isobutyl ketone, azobisisobutyronitrile was added as an initiator, and the reaction was carried out at 70 °C for 6 hours, and then the temperature was raised to 85 °C and reacted for 2 hours. The lower initial reaction temperature helps to control the reaction rate, while the higher final reaction temperature helps to improve the performance of the polymer.

[0109] Thus, a fluoropolymer anti-scratch composition was prepared.

[0110] Comparative Example 1 To compare the performance differences between the fluoropolymer anti-scratch agent and the traditional anti-scratch agent, a common traditional anti-scratch agent on the market was selected as a control in this example. The following is the formula of the traditional anti-scratch agent.

[0111] Experimental method: Traditional anti-scratch agent formula: (1) Polytetrafluoroethylene (PTFE) powder: 50%; (2) Silicone oil: 30%; (3) Mineral oil: 20%.

[0112] It should be noted that PTFE provides certain low-friction and non-adhesive properties, but may have limitations in terms of wear resistance and compatibility. Silicone oil increases the lubricity of the anti-scratch agent, but may be volatile at high temperatures, affecting long-term performance. Mineral oil is used to reduce costs, but its heat resistance and chemical resistance are poor.

[0113] Preparation method (1)Mix the above raw materials in a high-speed blender until evenly dispersed.

[0114] (2)It is prepared directly by physical mixing without a special polymerization process.

[0115] Comparative test experiment: For the fluoropolymer anti-scratch compositions prepared in Examples 1-3, surface energy test, water resistance test, alkali resistance test, solvent resistance test, wear resistance and durability test were carried out. The experimental results are shown in Table 1. The data of water resistance, alkali resistance and solvent resistance were obtained by standard test methods (ISO standard test methods).

[0116] Table 1. Comparison of anti-scratch agent performance in examples and comparative examples

[0117] (1)Referring to the data in Table 1, the surface energy of Comparative Example 1 (traditional anti-scratch agent) is 32.0 mN / m, which indicates that the traditional anti-scratch agent has limited effect in reducing surface tension and cannot effectively reduce scratch and adhesion problems. Examples 1-3 (new anti-scratch agent): The surface energy is significantly reduced to 14.3-14.7 mN / m, much lower than that of the traditional anti-scratch agent. This means that the new anti-scratch agent has an extremely low surface tension, can significantly reduce scratches and adhesion, and thus improve the anti-scratch performance.

[0118] (2)In terms of water resistance (increase in surface energy), the water resistance of Comparative Example 1 is poor, and the surface energy increases from 32.0 mN / m to 35.0 mN / m, an increase of 3.0 mN / m. This shows that the performance of the traditional anti-scratch agent drops significantly in a humid environment and is easily affected by water erosion and loses its anti-scratch effect. While for Examples 1-3: The water resistance is excellent, and the surface energy shows no obvious increase (no significant change was detected, marked as " / "). This indicates that the new anti-scratch agent can still maintain a low surface tension in a humid environment and its anti-scratch performance is not affected.

[0119] (3) In terms of alkali resistance (surface energy increase), the alkali resistance of Comparative Example 1 is poor, and the surface energy increases from 32.0 mN / m to 38.0 mN / m, an increase of 6.0 mN / m. This indicates that the performance of traditional anti-scratch agents deteriorates severely in an alkaline environment and is prone to failure due to chemical erosion. In contrast, Examples 1-3 have excellent alkali resistance, and the surface energy shows no obvious increase. This shows that the new anti-scratch agent can still maintain stable anti-scratch performance in an alkaline environment and is applicable to more industrial scenarios.

[0120] (4) In terms of solvent resistance, the solvent resistance of Comparative Example 1 is poor, and the surface energy increases from 32.0 mN / m to 36.0 mN / m, an increase of 4.0 mN / m. This indicates that the performance of traditional anti-scratch agents deteriorates significantly in an organic solvent environment and is prone to failure due to solvent erosion. In contrast, Examples 1-3 have excellent solvent resistance, and the surface energy shows no obvious increase. This shows that the new anti-scratch agent can still maintain a low surface tension in an organic solvent environment, and the anti-scratch performance is not affected.

[0121] (5) In terms of abrasion resistance (wear rate), the abrasion resistance of Comparative Example 1 is poor, and the wear rate is 15%. This indicates that traditional anti-scratch agents are prone to wear during long-term use, and the problems of scratches and damage are relatively serious. In contrast, the abrasion resistance of Examples 1-3 is significantly improved, and the wear rate is only 2%-3%. This shows that the new anti-scratch agent can effectively reduce scratches and damage during long-term use and extend the service life.

[0122] (6) In terms of durability (1000 hours), the durability of Comparative Example 1 is poor, and the performance decreases by 30% after 1000 hours. This indicates that traditional anti-scratch agents are prone to failure during long-term use and need to be replaced frequently. Examples 1-3 have excellent durability, and the performance only decreases by 5%-6% after 1000 hours. This shows that the new anti-scratch agent can still maintain a stable anti-scratch effect during long-term use and reduce the maintenance and replacement frequency.

[0123] Through comparative analysis, the new fluoropolymer anti-scratch agent is significantly superior to the traditional anti-scratch agent in terms of surface energy, water resistance, alkali resistance, solvent resistance, abrasion resistance, and durability. The low surface energy of the new anti-scratch agent can effectively reduce scratches and adhesion problems. At the same time, its excellent chemical resistance makes it perform well in terms of water resistance, alkali resistance, and solvent resistance, and is applicable to more complex environments. In addition, the high abrasion resistance and durability of the new anti-scratch agent enable it to maintain a stable anti-scratch effect during long-term use and reduce the maintenance and replacement frequency. Although its raw material cost may be slightly higher than that of traditional anti-scratch agents, its excellent performance and long service life can significantly reduce the maintenance cost and have a higher cost performance. Therefore, the new fluoropolymer anti-scratch agent is an ideal substitute for traditional anti-scratch agents and has significant market application advantages.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A fluoropolymer anti-scratch composition, characterized in that, The fluoropolymer anti-scratch composition includes the following components: Perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate, and butyl acrylate.

2. The fluoropolymer anti-scratch composition according to claim 1, wherein The fluoropolymer anti-scratch composition includes the following components in weight fractions: Perfluoroalkyl ethyl acrylate, 30 parts to 50 parts; Octadecyl acrylate, 10 parts to 30 parts; 2-hydroxyethyl methacrylate, 5 parts to 10 parts; Butyl acrylate, 5 parts to 20 parts.

3. A preparation method of a fluoropolymer anti-scratch composition, characterized in that, Including: Adding perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate, and butyl acrylate into an organic solvent to obtain a mixture; Adding an initiator to the mixture, and causing the perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate, and butyl acrylate in the mixture to undergo a polymerization reaction under the action of free radicals generated by the initiator to obtain a fluoropolymer anti-scratch composition; Preferably, the organic solvent includes methyl isobutyl ketone; Preferably, the initiator includes azobisisobutyronitrile; Preferably, the organic solvent accounts for 20% to 50% of the total weight; Preferably, the initiator accounts for 0.5% to 1.2% of the total weight; Preferably, the initiator accounts for 0.8% to 1.0% of the total weight; Preferably, the addition method of the initiator is to add it in batches, and the interval time for adding the initiator in different batches is 15 minutes to 30 minutes; Preferably, the number of batches of the addition of the initiator is at least two; Preferably, the preparation process of the mixture is carried out under a protective gas.

4. The preparation method of the fluoropolymer anti-scratch composition according to claim 3, characterized in that, The causing the perfluoroalkyl ethyl acrylate, octadecyl acrylate, 2-hydroxyethyl methacrylate, and butyl acrylate in the mixture to undergo a polymerization reaction under the action of free radicals generated by the initiator includes: Performing heat reaction treatment on the mixture added with the initiator in an initiation polymerization stage and an accelerated polymerization stage in sequence; Among them, the temperature of the accelerated polymerization stage is not less than that of the initiation polymerization stage.

5. The preparation method of the fluoropolymer anti-scratch composition according to claim 4, characterized in that, The temperature of the accelerated polymerization stage is greater than that of the initiation polymerization stage.

6. The preparation method of the fluoropolymer anti-scratch composition according to claim 4, characterized in that, The initiation polymerization stage is: Controlling the mixture after adding the initiator to react at a temperature of 70°C to 75°C for 5 hours to 6.5 hours.

7. The preparation method of the fluoropolymer anti-scratch composition according to claim 6, characterized in that, The initiation polymerization stage is: Controlling the mixture after adding the initiator to react at a temperature of 75°C for 6.5 hours.

8. The preparation method of the fluoropolymer anti-scratch composition according to claim 4, characterized in that, The accelerated polymerization stage is: Controlling the mixture after adding the initiator to be heated to a temperature of 80°C and react for 2 hours.

9. A method for cutting a pole piece, characterized in that, Including: Coating the surface of the conveyor belt of the cutting equipment with the fluoropolymer anti-scratch composition according to any one of claims 1-2, and performing pole piece cutting through the cutting equipment.

10. Use of a fluoropolymer anti-scratch composition in the preparation of a product for treating the surface of a conveyor belt in a cutting equipment.

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