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CN-121991453-A - Modified polypropylene base film, functional copper current collector and preparation method thereof

CN121991453ACN 121991453 ACN121991453 ACN 121991453ACN-121991453-A

Abstract

The invention discloses a modified polypropylene base film, a functional copper current collector and a preparation method thereof, and relates to the technical field of functional current collector base films. The raw materials of the modified polypropylene base film comprise a crosslinking master batch and an initiator, wherein the crosslinking master batch comprises pentaerythritol tetraacrylate and polypropylene with the mass ratio of 1 (5-15), and the addition amount of the initiator is 0.2-0.4wt% of the crosslinking master batch. The modified polypropylene base film prepared by the invention has strong interfacial binding force with the metal copper layer, and the functional copper current collector prepared based on the modified polypropylene base film has excellent stripping force and mechanical strength.

Inventors

  • Gao Shuobin
  • GU XIAOTONG
  • Zhao Fanjun
  • LI XUEFA

Assignees

  • 江阴纳力新材料科技有限公司

Dates

Publication Date
20260508
Application Date
20260211

Claims (10)

  1. 1. A modified polypropylene-based film is characterized in that raw materials of the modified polypropylene-based film comprise a crosslinking master batch and an initiator, wherein the crosslinking master batch comprises pentaerythritol tetraacrylate and polypropylene in a mass ratio of 1 (5-15), and the addition amount of the initiator is 0.2-0.4wt% of the crosslinking master batch.
  2. 2. The modified polypropylene-based film according to claim 1, wherein the modified polypropylene-based film is produced by the following steps: Step 1, adding pentaerythritol tetraacrylate and polypropylene into an organic solvent, stirring and mixing for 1-3 hours at 50-80 ℃ to form a crosslinked master batch, adding an initiator, and stirring and reacting for 1-3 hours at 140-170 ℃ to obtain a crosslinked modified PP polypropylene master batch; and 2, extruding, casting, biaxially stretching and post-treating the crosslinked modified PP polypropylene master batch to obtain the modified polypropylene base film.
  3. 3. The modified polypropylene-based film according to claim 1, wherein the raw materials of the modified polypropylene-based film further comprise modified talcum powder and a dispersing agent, the particle size of the modified talcum powder is 10-50 nm, the mass ratio of the modified talcum powder to the pentaerythritol tetraacrylate is (0.5-1): 1, and the adding amount of the dispersing agent is 0.05-0.08 wt% of the crosslinking master batch.
  4. 4. The modified polypropylene film according to claim 3, wherein the modified talc is prepared by the following steps: Adding talcum powder into ethanol, performing ultrasonic dispersion for 20-30 min, adjusting the pH to 4-5, adding methacryloxypropyl trimethoxysilane, setting the temperature to 50-70 ℃, stirring and reacting for 2-4 h, filtering, washing and drying, adding 0.2-0.5 mol/L NaOH, setting the temperature to 60-80 ℃, stirring for 2-4 h, adding HCl to adjust the pH to 6-7, filtering and drying to obtain pretreated talcum powder; and 2, adding the pretreated talcum powder into pyridine, dispersing in ultrasound, adding DMF, mixing, stirring to obtain talcum powder dispersion, adding N-methylglycine and 3, 4-dihydroxybenzaldehyde into the talcum powder dispersion to obtain a mixture, setting the temperature to 145-150 ℃, reacting for 90-110 hours, filtering, washing and drying to obtain the modified talcum powder.
  5. 5. A modified polypropylene film according to claim 4, wherein the pre-treated talcum powder comprises (8-12): 0.2-0.5): 25-35% by mass of talcum powder, methacryloxypropyl trimethoxysilane and NaOH, the talcum powder dispersion comprises (8-12): 9-16): 460-500% by mass of talcum powder, pyridine and DMF, and the mixture comprises (0.9-1.3): 1.0-1.2) by mass of N-methylglycine and 3, 4-dihydroxybenzaldehyde.
  6. 6. The modified polypropylene film according to claim 5, wherein the modified polypropylene film is produced by the following steps: Step 1, adding pentaerythritol tetraacrylate and polypropylene into an organic solvent to form a crosslinked master batch, sequentially adding an initiator, modified talcum powder and a dispersing agent, setting the temperature to be 220-280 ℃ and the pressure to be 0.8-2.0 MPa, and stirring and reacting for 150-300 minutes to obtain the crosslinked modified PP polypropylene master batch; and 2, extruding, casting, biaxially stretching and post-treating the crosslinked modified PP polypropylene master batch to obtain the modified polypropylene base film.
  7. 7. The modified polypropylene film according to claim 1, wherein the thickness of the modified polypropylene film is 4 to 5. Mu.m.
  8. 8. A functional copper current collector is characterized in that the functional copper current collector is prepared by taking the modified polypropylene base film as a base film according to any one of claims 1-7.
  9. 9. The method for preparing a functional copper current collector according to claim 8, wherein the method comprises the step of magnetron sputtering a copper layer on the surface of the modified polypropylene-based film.
  10. 10. The method for preparing a functional copper current collector according to claim 9, wherein the target material is copper, the sputtering power is 50-1000W, and the thickness of the copper layer is 100-5000 nm in the process of magnetron sputtering.

Description

Modified polypropylene base film, functional copper current collector and preparation method thereof Technical Field The invention relates to the technical field of functional current collector base films, in particular to a modified polypropylene base film, a functional copper current collector and a preparation method thereof. Background The current collector is a sheet material with high conductivity, and is generally made of a polymer material serving as a base film, and carriers serving as active substances are uniformly coated on two sides of the current collector, wherein polypropylene becomes one of ideal base materials due to abundant raw materials and low cost, and then a metal layer is plated on the surface of the current collector through magnetron sputtering, water electroplating and other processes, so that the current collector has excellent performance and a unique sandwich structure. The improvement of the performance of the lithium ion battery is a core challenge in the field of new energy, and a current collector is taken as a key component of the battery, so that the technical innovation of the current collector is very important. Compared with the traditional single current collector, the functional current collector has excellent performances of conductivity, low cost, high safety and the like, but the prior art still has certain technical bottlenecks that firstly, the interface bonding force is insufficient, polypropylene and a metal layer are obviously different in properties under the traditional magnetron sputtering process, only weak bonding force can be formed between the polypropylene and the metal layer, when the battery is subjected to charge-discharge circulation, the active substance volume change can form stress concentration at the interface, so that the metal layer is gradually peeled off, the peeling force is reduced, finally, the risk of short circuit in the battery is caused, secondly, the mechanical strength is insufficient, the polypropylene is used as a base film in the battery circulation and is deformed after being extruded by the active substance, the active substance is embedded with be temporarily released from one's regular work expansion stress, the base film is irreversibly plastically deformed, the base film is contracted, the metal layer is not supported due to shrinkage, the base film is cracked, a conductive network is invalid, the metal layer is finally cracked, and the battery capacity is reduced with the increase of the circulation times. In summary, to solve the above problems, a modified polypropylene-based film and a functional copper current collector are prepared. Disclosure of Invention The invention aims to provide a modified polypropylene-based film, a functional copper current collector and a preparation method thereof, so as to solve the problems in the background technology. In order to solve the technical problems, the invention provides the following technical scheme: The raw materials of the modified polypropylene-based film comprise a crosslinking master batch and an initiator, wherein the crosslinking master batch comprises pentaerythritol tetraacrylate and polypropylene with the mass ratio of 1 (5-15), and the addition amount of the initiator is 0.2-0.4wt% of the crosslinking master batch. Wherein the initiator comprises one or more of dicumyl peroxide, tert-butyl benzoyl peroxide, methyl ethyl ketone peroxide and benzoyl peroxide. More optimally, the preparation method of the modified polypropylene-based film comprises the following steps: Step 1, adding pentaerythritol tetraacrylate and polypropylene into an organic solvent, stirring and mixing for 1-3 hours at 50-80 ℃ to form a crosslinked master batch, adding an initiator, and stirring and reacting for 1-3 hours at 140-170 ℃ to obtain a crosslinked modified PP polypropylene master batch; and 2, extruding, casting, biaxially stretching and post-treating the crosslinked modified PP polypropylene master batch to obtain the modified polypropylene base film. More optimally, the raw materials of the modified polypropylene-based film also comprise modified talcum powder and a dispersing agent, wherein the particle size of the modified talcum powder is 10-50nm, the mass ratio of the modified talcum powder to the pentaerythritol tetraacrylate is (0.5-1): 1, and the adding amount of the dispersing agent is 0.05-0.08 wt% of the crosslinking master batch. Wherein the dispersing agent comprises one or more of maleic acid acrylic acid copolymer, polyvinylpyrrolidone and polyvinyl alcohol. More optimally, the preparation method of the modified talcum powder comprises the following steps: Adding talcum powder into ethanol, performing ultrasonic dispersion for 20-30 min, adjusting the pH to 4-5, adding methacryloxypropyl trimethoxysilane, setting the temperature to 50-70 ℃, stirring and reacting for 2-4 h, filtering, washing and drying, adding 0.2-0.5 mol/L NaOH, setting the temperature to 60-80 ℃