UV insulation protective tape for new energy battery and preparation process thereof

Abstract

The application discloses a UV insulation protective adhesive tape for new energy batteries and a preparation process thereof, and relates to the technical field of adhesives. Specifically, the process comprises the following steps: S1: uniformly mixing epoxy resin, epoxy acrylate, a photobase generator, a photosensitizer, a free radical inhibitor, dipropylene glycol diacrylate, pentaerythritol tetra-3-mercaptopropionate, a mercapto-modified ternary ethylene-propylene rubber, a fluorine-containing modifier and an organic solvent to obtain a UV adhesive; S2: coating the UV adhesive on an insulation base film, curing at 90-110 DEG C for 5-8 min to obtain an adhesive layer, and compounding a release film on the surface of the adhesive layer to obtain the UV insulation protective adhesive tape for new energy batteries; and the UV insulation protective adhesive tape prepared by the application is of a delayed curing type and has excellent insulation and chemical corrosion resistance.

Description

Technical Field

[0001] This invention relates to the field of adhesive tape technology, specifically a UV insulating protective tape for new energy batteries and its preparation process. Background Technology

[0002] With the continuous improvement of energy density of new energy batteries, the requirements for internal insulation and protection of battery modules are becoming increasingly stringent. As a key material to ensure the long-term reliability of batteries, insulating protective tape is widely used for fixing, insulating and protecting battery cells, battery modules and high-voltage connectors. Traditional tapes mostly use thermosetting adhesives, which have limitations such as long curing time, high energy consumption and heat accumulation affecting battery performance, making it difficult to meet the needs of efficient production and precision manufacturing.

[0003] In recent years, ultraviolet (UV) curing technology has gained widespread attention in the fields of adhesives and coatings due to its advantages such as rapid curing and room temperature operation. However, in the field of new energy batteries, blue polyester (PET) film is generally used as the base film material for tapes. Most of the ultraviolet light will be blocked, resulting in the adhesive layer not being able to cure, which limits its application.

[0004] In conclusion, solving the above problems and preparing a UV insulating protective tape for new energy batteries is of great significance. Summary of the Invention

[0005] The purpose of this invention is to provide a UV insulating protective tape for new energy batteries and its preparation process, so as to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A process for preparing a UV insulating protective tape for new energy batteries includes the following steps: S1: Epoxy resin, epoxy acrylate, photoalkali-generating agent, photosensitizer, free radical inhibitor, 1,6-hexanediol diacrylate, pentaerythritol tetra-3-mercaptopropionate, mercapto-modified EPDM rubber, fluorine-containing modifier, and organic solvent are mixed evenly to obtain a UV adhesive. S2: Apply UV adhesive to the insulating base film and cure at 90~110℃ for 5~8 minutes to obtain an adhesive layer. Composite a release film is then applied to the surface of the adhesive layer to obtain a UV insulating protective tape for new energy batteries. The fluorinated modifier comprises fluorinated monofunctional epoxy monomers and fluorinated difunctional acrylate monomers in a mass ratio of 1.5 to 2.5:1.

[0007] Preferably, the UV adhesive comprises the following raw materials, by weight: 50 parts epoxy resin, 25-30 parts epoxy acrylate, 1-2 parts photoalkali-generating agent, 0.5-1 part photosensitizer, 0.5-1 part free radical inhibitor, 15-17 parts 1,6-hexanediol diacrylate, 60-70 parts pentaerythritol tetra-3-mercaptopropionate, 8-10 parts mercapto-modified ethylene propylene diene monomer (EPDM) rubber, 10-14 parts fluorine-containing modifier, and 25-30 parts organic solvent.

[0008] More preferably, the preparation method of the fluorinated monofunctional epoxy monomer includes the following steps: mixing 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol, epichlorohydrin and sodium hydroxide evenly, stirring and reacting at 110°C for 10-16 h, removing unreacted monomers by rotary evaporation to obtain the fluorinated monofunctional epoxy monomer.

[0009] Preferably, the fluorinated monofunctional epoxy monomer comprises the following raw materials, in parts by weight: 24-25 parts of 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol, 180-190 parts of epichlorohydrin, and 4-5 parts of sodium hydroxide, mixed evenly.

[0010] A preferred method for preparing the fluorinated bifunctional acrylate monomer includes the following steps: 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene and triethylamine are added to dichloromethane and mixed evenly, the mixture is cooled to 0-5°C, acryloyl chloride is added dropwise, and the dropwise addition time is controlled to be 1-2 h. After the dropwise addition is completed, the temperature is raised to 20-30°C, and the reaction is continued to be stirred for 8-16 h. The mixture is then heated to 40-45°C and the reaction is continued to be stirred for 4-6 h. The mixture is filtered, washed with saturated sodium bicarbonate and saturated sodium chloride solutions respectively, dried, and the solvent is removed by rotary evaporation to obtain the fluorinated bifunctional acrylate monomer.

[0011] Preferably, the fluorinated bifunctional acrylate monomer comprises the following raw materials, in parts by weight: 8-10 parts of 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene, 5.5-6 parts of triethylamine, 50-100 parts of dichloromethane, and 4.5-5 parts of acryloyl chloride.

[0012] Preferably, the photoalkali-producing agent includes WPBG-300; the photosensitizer includes 2-isopropylthioxanthone; and the free radical inhibitor includes 2,2,6,6-tetramethylpiperidine-1-oxo radical.

[0013] Preferred method for preparing UV adhesive includes the following steps: (1) adding photoalkali-generating agent to epoxy resin and mixing evenly at 100-110°C to obtain premix A; (2) adding mercapto-modified EPDM rubber and fluorinated monofunctional epoxy monomer to a portion of organic solvent and stirring and mixing at 40-50°C for 0.5-1h to obtain premix B; (3) adding photosensitizer, free radical inhibitor, and fluorinated difunctional acrylate monomer to the remaining organic solvent and mixing evenly at 20-25°C to obtain premix C; (4) adding premix B, premix C, 1,6-hexanediol diacrylate, pentaerythritol tetra-3-mercaptopropionate, and epoxy acrylate to premix A in sequence and mixing evenly, then degassing under vacuum to obtain UV adhesive.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: This application introduces mercapto-modified EPDM rubber into a delayed-curing UV adhesive and adds a fluorinated modifier composed of a specific fluorinated monofunctional epoxy monomer and a fluorinated difunctional acrylate monomer to synergistically improve the adhesive properties of the adhesive, so that the prepared UV insulating protective tape has excellent insulation and chemical corrosion resistance.

[0015] The fluorinated modifier is prepared by reacting an alcohol compound containing a hexafluoroisopropanol structure with epichlorohydrin via etherification and epoxidation to prepare a fluorinated monofunctional epoxy monomer, and by reacting it with acryloyl chloride via esterification to prepare a fluorinated difunctional acrylate monomer. By introducing fluorinated hydrophobic and oleophobic segments, the surface hydrophobicity and chemical corrosion resistance of the adhesive can be improved, as well as its insulation performance. Simultaneously, the monofunctional fluorinated epoxy monomer and the difunctional fluorinated acrylate monomer are selected to synergistically construct a low surface energy crosslinking network during the curing process. When exposed to ultraviolet light, the photoalkali-producing agent decomposes under light to generate alkaline substances, triggering the rapid formation of a crosslinking network between the thiol groups and the difunctional fluorinated acrylate monomer within the system. This provides initial strength and fixes the fluorinated chain ends, ensuring uniform dispersion in the system and reducing migration. In subsequent room temperature processes, the monofunctional fluorinated epoxy monomer reacts slowly with the remaining thiol groups. Due to its small size and monofunctional nature, it exhibits a certain degree of migration, thereby improving the chemical corrosion resistance of the adhesive.

[0016] Ethylene propylene diene monomer (EPDM) rubber, with its saturated main chain and lack of polar groups, possesses excellent insulation properties and chemical stability. However, due to the difference in polarity, it exhibits extremely poor compatibility with the epoxy resin matrix in delayed-curing UV adhesives, making uniform dispersion difficult. Furthermore, its unsaturated bonds have low reactivity, and the extremely short UV irradiation time in delayed-curing systems hinders effective participation in thiol-modified click reactions. Therefore, this application employs a chemical modification method involving thioacetic acid esterification followed by hydrolysis to introduce thiol groups, enhancing reactivity and facilitating the formation of an interpenetrating structure with the matrix, thereby improving compatibility. Simultaneously, the premixing of monofunctional fluorinated epoxy monomers with thiol-modified EPDM rubber improves its dispersibility upon subsequent addition to the matrix, thus ensuring adhesive strength while enhancing the tape's insulation and chemical resistance. Detailed Implementation

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] It should be noted that the preparation of thiol-modified EPDM rubber is based on existing technology. The process is as follows: (1) Under a nitrogen atmosphere, 10 parts of EPDM rubber (molecular weight of 39000, ethylene / propylene ratio of 46 / 54, unsaturation of 9.5%, diene type of ENB) are added to 100 parts of toluene and mixed evenly at 80°C. 1.5 parts of thioacetic acid and 0.04 parts of azobisisobutyronitrile are added and stirred at 85°C for 6 hours. Methanol is added for washing and drying to obtain thioacetic acid-esterified EPDM rubber. (2) Under a nitrogen atmosphere, 10 parts of thioacetic acid-esterified EPDM rubber are added to 150 parts of toluene and mixed evenly at 65°C. 12 parts of 10wt% sodium hydroxide methanol solution are slowly added and stirred for 2 hours. 35 parts of 3.6wt% hydrochloric acid solution are added, centrifuged, washed, dried, and stored at low temperature to obtain thiol-modified EPDM rubber.

[0019] Example 1: The preparation process of UV insulating protective tape includes the following steps; wherein, parts are parts by weight: Step 1: Preparation of fluorine-containing monofunctional epoxy monomers: 24.4 parts of 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol, 185 parts of epichlorohydrin, and 4.4 parts of sodium hydroxide were mixed evenly and stirred at 110℃ for 12 h. Unreacted monomers were removed by rotary evaporation to obtain fluorine-containing monofunctional epoxy monomers. Step 2: Preparation of fluorinated bifunctional acrylate monomer: 10 parts of 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene and 5.93 parts of triethylamine were added to 50 parts of dichloromethane and mixed evenly. The mixture was cooled to 1°C, and 4.85 parts of acryloyl chloride were added dropwise over a period of 1.5 h. After the addition was complete, the temperature was raised to 25°C and the reaction was stirred for 12 h. The mixture was then heated to 40°C and stirred for 5 h. The mixture was filtered, washed with saturated sodium bicarbonate and saturated sodium chloride solutions, dried, and the solvent was removed by rotary evaporation to obtain the fluorinated bifunctional acrylate monomer. Step 3: Preparation of UV adhesive: (1) Add photoalkali-generating agent to epoxy resin and mix evenly at 105℃ to obtain premix A; (2) Add mercapto-modified EPDM rubber and fluorinated monofunctional epoxy monomer to half of the organic solvent and stir and mix at 45℃ for 0.5h to obtain premix B; (3) Add photosensitizer, free radical inhibitor, and fluorinated difunctional acrylate monomer to the remaining half of the organic solvent and mix evenly at 25℃ to obtain premix C; (4) Add premix B, premix C, 1,6-hexanediol diacrylate, and pentaerythritol tetra-3-mercapto-1-mercapto-1-propanediol to the premix B. Poly(propylene glycol) acrylate and epoxy acrylate are sequentially added to premixed solution A and mixed evenly. The mixture is then degassed under vacuum to obtain a UV adhesive. The UV adhesive comprises the following raw materials in parts by weight: 50 parts epoxy resin, 26 parts epoxy acrylate, 2 parts photoalkali-generating agent, 0.8 parts photosensitizer, 0.8 parts free radical inhibitor, 16 parts 1,6-hexanediol diacrylate, 65 parts pentaerythritol tetra-3-mercaptopropionate, 9 parts mercapto-modified EPDM rubber, 12 parts fluorinated modifier (8 parts fluorinated monofunctional epoxy monomer and 4 parts fluorinated difunctional acrylate monomer), and 25 parts organic solvent. Step 4: Preparation of UV insulating protective tape: Apply UV adhesive to the insulating base film and cure at 105℃ for 5 minutes to obtain an adhesive layer. Then, laminate a release film onto the surface of the adhesive layer to obtain a UV insulating protective tape for new energy batteries.

[0020] Among them, the epoxy resin is model E51; the epoxy acrylate is model EA; the photoalkali-generating agent is model WPBG-300; the photosensitizer is 2-isopropylthioxanthone; the free radical inhibitor is 2,2,6,6-tetramethylpiperidine-1-oxy free radical; the CAS number of 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol is 718-64-9; and the CAS number of 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene is 802-93-7.

[0021] Example 2: The preparation process of UV insulating protective tape includes the following steps; wherein, parts are parts by weight: Step 1: Preparation of fluorine-containing monofunctional epoxy monomers: 24.4 parts of 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol, 185 parts of epichlorohydrin, and 4.4 parts of sodium hydroxide were mixed evenly and stirred at 110℃ for 12 h. Unreacted monomers were removed by rotary evaporation to obtain fluorine-containing monofunctional epoxy monomers. Step 2: Preparation of fluorinated bifunctional acrylate monomer: 10 parts of 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene and 5.93 parts of triethylamine were added to 50 parts of dichloromethane and mixed evenly. The mixture was cooled to 1°C, and 4.85 parts of acryloyl chloride were added dropwise over a period of 1.5 h. After the addition was complete, the temperature was raised to 25°C and the reaction was stirred for 12 h. The mixture was then heated to 40°C and stirred for 5 h. The mixture was filtered, washed with saturated sodium bicarbonate and saturated sodium chloride solutions, dried, and the solvent was removed by rotary evaporation to obtain the fluorinated bifunctional acrylate monomer. Step 3: Preparation of UV adhesive: (1) Add the photoalkali-generating agent to the epoxy resin and mix evenly at 105℃ to obtain premix A; (2) Add the mercapto-modified EPDM rubber and the fluorinated monofunctional epoxy monomer to half of the organic solvent and stir and mix at 45℃ for 0.5h to obtain premix B; (3) Add the photosensitizer, free radical inhibitor, and fluorinated difunctional acrylate monomer to the remaining half of the organic solvent and mix evenly at 25℃ to obtain premix C; (4) Add premix B, premix C, 1,6-hexanediol diacrylate, and pentaerythritol tetra-3- Mercaptopropionate and epoxy acrylate are sequentially added to premixed liquid A and mixed evenly. The mixture is then degassed under vacuum to obtain a UV adhesive. The UV adhesive comprises the following raw materials in parts by weight: 50 parts epoxy resin, 30 parts epoxy acrylate, 2 parts photoalkali-generating agent, 1 part photosensitizer, 1 part free radical inhibitor, 17 parts 1,6-hexanediol diacrylate, 70 parts pentaerythritol tetra-3-mercaptopropionate, 10 parts mercapto-modified EPDM rubber, 14 parts fluorinated modifier (9 parts fluorinated monofunctional epoxy monomer and 5 parts fluorinated difunctional acrylate monomer), and 30 parts organic solvent. Step 4: Preparation of UV insulating protective tape: Apply UV adhesive to the insulating base film and cure at 105℃ for 5 minutes to obtain an adhesive layer. Then, laminate a release film onto the surface of the adhesive layer to obtain a UV insulating protective tape for new energy batteries.

[0022] Example 3: The preparation process of UV insulating protective tape includes the following steps; wherein, parts are parts by weight: Step 1: Preparation of fluorine-containing monofunctional epoxy monomers: 24.4 parts of 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol, 185 parts of epichlorohydrin, and 4.4 parts of sodium hydroxide were mixed evenly and stirred at 110℃ for 12 h. Unreacted monomers were removed by rotary evaporation to obtain fluorine-containing monofunctional epoxy monomers. Step 2: Preparation of fluorinated bifunctional acrylate monomer: 10 parts of 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene and 5.93 parts of triethylamine were added to 50 parts of dichloromethane and mixed evenly. The mixture was cooled to 1°C, and 4.85 parts of acryloyl chloride were added dropwise over a period of 1.5 h. After the addition was complete, the temperature was raised to 25°C and the reaction was stirred for 12 h. The mixture was then heated to 40°C and stirred for 5 h. The mixture was filtered, washed with saturated sodium bicarbonate and saturated sodium chloride solutions, dried, and the solvent was removed by rotary evaporation to obtain the fluorinated bifunctional acrylate monomer. Step 3: Preparation of UV adhesive: (1) Add photoalkali-generating agent to epoxy resin and mix evenly at 105℃ to obtain premix A; (2) Add mercapto-modified EPDM rubber and fluorinated monofunctional epoxy monomer to half of the organic solvent and stir and mix at 45℃ for 0.5h to obtain premix B; (3) Add photosensitizer, free radical inhibitor, and fluorinated difunctional acrylate monomer to the remaining half of the organic solvent and mix evenly at 25℃ to obtain premix C; (4) Add premix B, premix C, 1,6-hexanediol diacrylate, and pentaerythritol tetra-3-mercapto-1-mercapto-1-propanediol to the premix B. Poly(methyl methacrylate) and epoxy acrylate are sequentially added to premixed liquid A and mixed evenly. The mixture is then degassed under vacuum to obtain a UV adhesive. The UV adhesive comprises the following raw materials in parts by weight: 50 parts epoxy resin, 25 parts epoxy acrylate, 1 part photoalkali-generating agent, 0.5 parts photosensitizer, 0.5 parts free radical inhibitor, 15 parts 1,6-hexanediol diacrylate, 60 parts pentaerythritol tetra-3-mercaptopropionate, 8 parts mercapto-modified EPDM rubber, 10 parts fluorinated modifier (7 parts fluorinated monofunctional epoxy monomer, 3 parts fluorinated difunctional acrylate monomer), and 25 parts organic solvent. Step 4: Preparation of UV insulating protective tape: Apply UV adhesive to the insulating base film and cure at 105℃ for 5 minutes to obtain an adhesive layer. Then, laminate a release film onto the surface of the adhesive layer to obtain a UV insulating protective tape for new energy batteries.

[0023] Comparative Example 1: Based on Example 1, without adding fluorinated monofunctional epoxy monomers, and with the remaining processes unchanged, the specific steps included are as follows: Step 1: Preparation of fluorinated bifunctional acrylate monomer: 10 parts of 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene and 5.93 parts of triethylamine were added to 50 parts of dichloromethane and mixed evenly. The mixture was cooled to 1°C, and 4.85 parts of acryloyl chloride were added dropwise over a period of 1.5 h. After the addition was complete, the temperature was raised to 25°C and the reaction was stirred for 12 h. The mixture was then heated to 40°C and stirred for 5 h. The mixture was filtered, washed with saturated sodium bicarbonate and saturated sodium chloride solutions, dried, and the solvent was removed by rotary evaporation to obtain the fluorinated bifunctional acrylate monomer. Step 2: Preparation of UV adhesive: (1) Add the photoalkali-generating agent to the epoxy resin and mix evenly at 105℃ to obtain premix A; (2) Add the mercapto-modified EPDM rubber to half of the organic solvent and stir and mix at 45℃ for 0.5h to obtain premix B; (3) Add the photosensitizer, free radical inhibitor, and fluorinated bifunctional acrylate monomer to the remaining half of the organic solvent and mix evenly at 25℃ to obtain premix C; (4) Add premix B, premix C, 1,6-hexanediol diacrylate, and pentaerythritol tetra-3 - Mercaptopropionate and epoxy acrylate are sequentially added to premixed liquid A and mixed evenly. Vacuum degassing is then performed to obtain UV adhesive. The UV adhesive comprises the following raw materials in parts by weight: 50 parts epoxy resin, 26 parts epoxy acrylate, 2 parts photoalkali-generating agent, 0.8 parts photosensitizer, 0.8 parts free radical inhibitor, 16 parts 1,6-hexanediol diacrylate, 65 parts pentaerythritol tetra-3-mercaptopropionate, 9 parts mercapto-modified EPDM rubber, 12 parts fluorinated modifier (fluorinated bifunctional acrylate monomer), and 25 parts organic solvent. Step 3: Preparation of UV insulating protective tape: The UV adhesive is coated on the insulating base film and cured at 105°C for 5 minutes to obtain the adhesive layer. A release film is then laminated on the surface of the adhesive layer to obtain the UV insulating protective tape for new energy batteries.

[0024] Comparative Example 2: Based on Example 1, without adding fluorinated bifunctional acrylate monomers, and with the rest of the process unchanged, specifically including the following steps: Step 1: Preparation of fluorine-containing monofunctional epoxy monomers: 24.4 parts of 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol, 185 parts of epichlorohydrin, and 4.4 parts of sodium hydroxide were mixed evenly and stirred at 110℃ for 12 h. Unreacted monomers were removed by rotary evaporation to obtain fluorine-containing monofunctional epoxy monomers. Step 2: Preparation of UV adhesive: (1) Add the photoalkali-generating agent to the epoxy resin and mix evenly at 105℃ to obtain premix A; (2) Add the mercapto-modified EPDM rubber and the fluorinated monofunctional epoxy monomer to half of the organic solvent and stir and mix at 45℃ for 0.5h to obtain premix B; (3) Add the photosensitizer and free radical inhibitor to the remaining half of the organic solvent and mix evenly at 25℃ to obtain premix C; (4) Add premix B, premix C, 1,6-hexanediol diacrylate, and pentaerythritol tetra-3 - Mercaptopropionate and epoxy acrylate are sequentially added to premixed liquid A and mixed evenly. Vacuum degassing is then performed to obtain UV adhesive. The UV adhesive comprises the following raw materials in parts by weight: 50 parts epoxy resin, 26 parts epoxy acrylate, 2 parts photoalkali-generating agent, 0.8 parts photosensitizer, 0.8 parts free radical inhibitor, 16 parts 1,6-hexanediol diacrylate, 65 parts pentaerythritol tetra-3-mercaptopropionate, 9 parts mercapto-modified EPDM rubber, 12 parts fluorinated modifier (fluorinated monofunctional epoxy monomer), and 25 parts organic solvent. Step 3: Preparation of UV insulating protective tape: The UV adhesive is coated on the insulating base film and cured at 105°C for 5 minutes to obtain the adhesive layer. A release film is then laminated on the surface of the adhesive layer to obtain the UV insulating protective tape for new energy batteries.

[0025] Comparative Example 3: Based on Example 1, without the addition of mercapto-modified EPDM rubber, and with the remaining processes unchanged, specifically including the following steps: Step 1: Preparation of fluorine-containing monofunctional epoxy monomers: 24.4 parts of 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol, 185 parts of epichlorohydrin, and 4.4 parts of sodium hydroxide were mixed evenly and stirred at 110℃ for 12 h. Unreacted monomers were removed by rotary evaporation to obtain fluorine-containing monofunctional epoxy monomers. Step 2: Preparation of fluorinated bifunctional acrylate monomer: 10 parts of 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene and 5.93 parts of triethylamine were added to 50 parts of dichloromethane and mixed evenly. The mixture was cooled to 1°C, and 4.85 parts of acryloyl chloride were added dropwise over a period of 1.5 h. After the addition was complete, the temperature was raised to 25°C and the reaction was stirred for 12 h. The mixture was then heated to 40°C and stirred for 5 h. The mixture was filtered, washed with saturated sodium bicarbonate and saturated sodium chloride solutions, dried, and the solvent was removed by rotary evaporation to obtain the fluorinated bifunctional acrylate monomer. Step 3: Preparation of UV adhesive: (1) Add the photoalkali-generating agent to the epoxy resin and mix evenly at 105℃ to obtain premix A; (2) Add the fluorinated monofunctional epoxy monomer to half of the organic solvent and stir and mix at 45℃ for 0.5h to obtain premix B; (3) Add the photosensitizer, free radical inhibitor, and fluorinated difunctional acrylate monomer to the remaining half of the organic solvent and mix evenly at 25℃ to obtain premix C; (4) Add premix B, premix C, 1,6-hexanediol diacrylate, and pentaerythritol tetra-3- Mercaptopropionate and epoxy acrylate are sequentially added to premixed solution A and mixed evenly. The mixture is then degassed under vacuum to obtain a UV adhesive. The UV adhesive comprises the following raw materials in parts by weight: 50 parts epoxy resin, 26 parts epoxy acrylate, 2 parts photoalkali-generating agent, 0.8 parts photosensitizer, 0.8 parts free radical inhibitor, 16 parts 1,6-hexanediol diacrylate, 65 parts pentaerythritol tetra-3-mercaptopropionate, 12 parts fluorinated modifier (8 parts fluorinated monofunctional epoxy monomer and 4 parts fluorinated difunctional acrylate monomer), and 25 parts organic solvent. Step 4: Preparation of UV insulating protective tape: Apply UV adhesive to the insulating base film and cure at 105℃ for 5 minutes to obtain an adhesive layer. Then, laminate a release film onto the surface of the adhesive layer to obtain a UV insulating protective tape for new energy batteries.

[0026] Comparative Example 4: Based on Example 1, the mercapto-modified EPDM rubber was not pre-blended with a fluorinated monofunctional epoxy monomer, and the remaining processes remained unchanged, specifically including the following steps: Step 1: Preparation of fluorine-containing monofunctional epoxy monomers: 24.4 parts of 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol, 185 parts of epichlorohydrin, and 4.4 parts of sodium hydroxide were mixed evenly and stirred at 110℃ for 12 h. Unreacted monomers were removed by rotary evaporation to obtain fluorine-containing monofunctional epoxy monomers. Step 2: Preparation of fluorinated bifunctional acrylate monomer: 10 parts of 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene and 5.93 parts of triethylamine were added to 50 parts of dichloromethane and mixed evenly. The mixture was cooled to 1°C, and 4.85 parts of acryloyl chloride were added dropwise over a period of 1.5 h. After the addition was complete, the temperature was raised to 25°C and the reaction was stirred for 12 h. The mixture was then heated to 40°C and stirred for 5 h. The mixture was filtered, washed with saturated sodium bicarbonate and saturated sodium chloride solutions, dried, and the solvent was removed by rotary evaporation to obtain the fluorinated bifunctional acrylate monomer. Step 3: Preparation of UV adhesive: (1) Add the photoalkali-generating agent to the epoxy resin and mix evenly at 105℃ to obtain premix A; (2) Add the mercapto-modified EPDM rubber to half of the organic solvent and stir and mix at 45℃ for 0.5h to obtain premix B; (3) Add the photosensitizer, free radical inhibitor, fluorinated monofunctional epoxy monomer, and fluorinated difunctional acrylate monomer to the remaining half of the organic solvent and mix evenly at 25℃ to obtain premix C; (4) Add premix B, premix C, 1,6-hexanediol diacrylate, and pentaerythritol tetra-3-mercapto-1 ... Poly(propylene glycol) acrylate and epoxy acrylate are sequentially added to premixed solution A and mixed evenly. The mixture is then degassed under vacuum to obtain a UV adhesive. The UV adhesive comprises the following raw materials in parts by weight: 50 parts epoxy resin, 26 parts epoxy acrylate, 2 parts photoalkali-generating agent, 0.8 parts photosensitizer, 0.8 parts free radical inhibitor, 16 parts 1,6-hexanediol diacrylate, 65 parts pentaerythritol tetra-3-mercaptopropionate, 9 parts mercapto-modified EPDM rubber, 12 parts fluorinated modifier (8 parts fluorinated monofunctional epoxy monomer and 4 parts fluorinated difunctional acrylate monomer), and 25 parts organic solvent. Step 4: Preparation of UV insulating protective tape: Apply UV adhesive to the insulating base film and cure at 105℃ for 5 minutes to obtain an adhesive layer. Then, laminate a release film onto the surface of the adhesive layer to obtain a UV insulating protective tape for new energy batteries.

[0027] Comparative Example 5: Based on Example 1, a fluorine-containing bifunctional epoxy monomer was used, with the remaining processes unchanged. The specific steps included were as follows: Step 1: Preparation of fluorine-containing bifunctional epoxy monomer: 20.5 parts of 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene, 185 parts of epichlorohydrin and 4.4 parts of sodium hydroxide were mixed evenly and stirred at 110℃ for 12 h. Unreacted monomers were removed by rotary evaporation to obtain fluorine-containing bifunctional epoxy monomer. Step 2: Preparation of fluorinated bifunctional acrylate monomer: 10 parts of 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene and 5.93 parts of triethylamine were added to 50 parts of dichloromethane and mixed evenly. The mixture was cooled to 1°C, and 4.85 parts of acryloyl chloride were added dropwise over a period of 1.5 h. After the addition was complete, the temperature was raised to 25°C and the reaction was stirred for 12 h. The mixture was then heated to 40°C and stirred for 5 h. The mixture was filtered, washed with saturated sodium bicarbonate and saturated sodium chloride solutions, dried, and the solvent was removed by rotary evaporation to obtain the fluorinated bifunctional acrylate monomer. Step 3: Preparation of UV adhesive: (1) Add the photoalkali-generating agent to the epoxy resin and mix evenly at 105℃ to obtain premix A; (2) Add the mercapto-modified EPDM rubber and the fluorinated bifunctional epoxy monomer to half of the organic solvent and stir and mix at 45℃ for 0.5h to obtain premix B; (3) Add the photosensitizer, free radical inhibitor, and fluorinated bifunctional acrylate monomer to the remaining half of the organic solvent and mix evenly at 25℃ to obtain premix C; (4) Add premix B, premix C, 1,6-hexanediol diacrylate, and pentaerythritol tetra-3-mercapto-1-mercapto-1-propanediol to the premix B. Poly(propylene glycol) acrylate and epoxy acrylate are sequentially added to premixed solution A and mixed evenly. The mixture is then degassed under vacuum to obtain a UV adhesive. The UV adhesive comprises the following raw materials in parts by weight: 50 parts epoxy resin, 26 parts epoxy acrylate, 2 parts photoalkali-generating agent, 0.8 parts photosensitizer, 0.8 parts free radical inhibitor, 16 parts 1,6-hexanediol diacrylate, 65 parts pentaerythritol tetra-3-mercaptopropionate, 9 parts mercapto-modified EPDM rubber, 12 parts fluorinated modifier (8 parts fluorinated bifunctional epoxy monomer, 4 parts fluorinated bifunctional acrylate monomer), and 25 parts organic solvent. Step 4: Preparation of UV insulating protective tape: Apply UV adhesive to the insulating base film and cure at 105℃ for 5 minutes to obtain an adhesive layer. Then, laminate a release film onto the surface of the adhesive layer to obtain a UV insulating protective tape for new energy batteries.

[0028] Performance testing: The tapes were prepared according to the methods of each embodiment and comparative example. After removing the release film from the tapes, they were tested under light intensity of 30mW / cm at a wavelength of 365nm. 2 After being treated with ultraviolet light for 20 seconds, the sample adhered to the surface of the battery aluminum plate and was left to stand at room temperature for 72 hours to obtain the test sample.

[0029] (1) Tensile shear strength test was performed in accordance with GB / T 7124. The tensile rate was set to 5 mm / min. Five samples were tested for each example and the average value was taken. (2) Measure the insulation resistance value according to GB / T 1408.2, under the condition of DC voltage of 1500V and test time of 60 seconds; (3) Soak the sample in an acidic sample at 80℃ and pH 2 for 1 hour, wash it, dry it at room temperature, measure the tensile shear strength again, and calculate the retention rate; the experimental data are shown in the table below.

[0030] In conclusion, Comparative Example 1, without the addition of fluorinated monofunctional epoxy monomers, lacked low surface energy migration components in the post-curing stage, resulting in defects in the crosslinking network, a decrease in tensile shear strength, and a reduction in chemical corrosion resistance. Comparative Example 2, without the addition of fluorinated difunctional acrylate monomers, showed a decrease in crosslinking density and dispersibility in the early curing stage, leading to a reduction in insulation. Comparative Example 3, without the addition of mercapto-modified EPDM rubber, showed an increase in strength but a decrease in insulation performance. Comparative Example 4, without pre-blending the mercapto-modified EPDM rubber with fluorinated monofunctional epoxy monomers, showed a decrease in dispersibility, tensile shear strength, and chemical corrosion resistance. Comparative Example 5, using fluorinated difunctional epoxy monomers, lacked the migration of monofunctional components, resulting in reduced chemical corrosion resistance.

[0031] In summary, this application introduces mercapto-modified EPDM rubber into a delayed-curing UV adhesive and adds a fluorinated modifier composed of a specific fluorinated monofunctional epoxy monomer and a fluorinated difunctional acrylate monomer to synergistically improve the adhesive properties of the adhesive, resulting in a UV insulating protective tape with excellent insulation and chemical corrosion resistance.

[0032] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A preparation process for a UV insulating protective tape for new energy batteries, characterized in that: Includes the following steps: S1: Epoxy resin, epoxy acrylate, photoalkali-generating agent, photosensitizer, free radical inhibitor, 1,6-hexanediol diacrylate, pentaerythritol tetra-3-mercaptopropionate, mercapto-modified EPDM rubber, fluorine-containing modifier, and organic solvent are mixed evenly to obtain a UV adhesive. S2: Apply UV adhesive to the insulating base film and cure at 90~110℃ for 5~8 minutes to obtain an adhesive layer. Composite a release film is then applied to the surface of the adhesive layer to obtain a UV insulating protective tape for new energy batteries. The fluorinated modifier comprises fluorinated monofunctional epoxy monomers and fluorinated difunctional acrylate monomers in a mass ratio of 1.5 to 2.5:

1.

2. The preparation process of a UV insulating protective tape for new energy batteries according to claim 1, characterized in that: The UV adhesive comprises the following raw materials, by weight: 50 parts epoxy resin, 25-30 parts epoxy acrylate, 1-2 parts photoalkali-generating agent, 0.5-1 part photosensitizer, 0.5-1 part free radical inhibitor, 15-17 parts 1,6-hexanediol diacrylate, 60-70 parts pentaerythritol tetra-3-mercaptopropionate, 8-10 parts mercapto-modified ethylene propylene diene monomer (EPDM) rubber, 10-14 parts fluorine-containing modifier, and 25-30 parts organic solvent.

3. The preparation process of a UV insulating protective tape for new energy batteries according to claim 1, characterized in that: The preparation method of the fluorinated monofunctional epoxy monomer includes the following steps: 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol, epichlorohydrin and sodium hydroxide are mixed evenly, stirred and reacted at 110°C for 10-16 h, and unreacted monomers are removed by rotary evaporation to obtain the fluorinated monofunctional epoxy monomer.

4. The preparation process of a UV insulating protective tape for new energy batteries according to claim 3, characterized in that: The fluorinated monofunctional epoxy monomer comprises the following raw materials, by weight: 24-25 parts of 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol, 180-190 parts of epichlorohydrin, and 4-5 parts of sodium hydroxide, mixed evenly.

5. The preparation process of a UV insulating protective tape for new energy batteries according to claim 1, characterized in that: The preparation method of the fluorinated bifunctional acrylate monomer includes the following steps: 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene and triethylamine are added to dichloromethane and mixed evenly, the temperature is lowered to 0~5℃, acryloyl chloride is added dropwise, the dropwise addition time is controlled to be 1~2h, after the dropwise addition is completed, the temperature is raised to 20~30℃, the reaction is continued to be stirred for 8~16h, the temperature is raised to 40~45℃, the reaction is continued to be stirred for 4~6h, the mixture is filtered, washed with saturated sodium bicarbonate and saturated sodium chloride solutions respectively, dried, and the solvent is removed by rotary evaporation to obtain the fluorinated bifunctional acrylate monomer.

6. The preparation process of a UV insulating protective tape for new energy batteries according to claim 5, characterized in that: The fluorinated bifunctional acrylate monomer comprises the following raw materials, by weight: 8-10 parts 1,3-bis(α-hydroxyhexafluoroisopropyl)benzene, 5.5-6 parts triethylamine, 50-100 parts dichloromethane, and 4.5-5 parts acryloyl chloride.

7. The preparation process of a UV insulating protective tape for new energy batteries according to claim 1, characterized in that: The photoalkali-producing agent includes WPBG-300; the photosensitizer includes 2-isopropylthioxanthrone; and the free radical inhibitor includes 2,2,6,6-tetramethylpiperidine-1-oxo radical.

8. The preparation process of a UV insulating protective tape for new energy batteries according to claim 1, characterized in that: The preparation method of the UV adhesive includes the following steps: (1) adding the photoalkali-generating agent to the epoxy resin and mixing it evenly at 100~110℃ to obtain premix A; (2) adding the mercapto-modified EPDM rubber and the fluorinated monofunctional epoxy monomer to a portion of the organic solvent and stirring and mixing at 40~50℃ for 0.5~1h to obtain premix B; (3) adding the photosensitizer, free radical inhibitor, and fluorinated difunctional acrylate monomer to the remaining organic solvent and mixing it evenly at 20~25℃ to obtain premix C; (4) adding premix B, premix C, 1,6-hexanediol diacrylate, pentaerythritol tetra-3-mercaptopropionate, and epoxy acrylate to premix A in sequence and mixing evenly, then degassing under vacuum to obtain the UV adhesive.

9. The UV insulating protective tape obtained by the preparation process of a UV insulating protective tape for new energy batteries according to any one of claims 1 to 8.

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