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CN-122011592-A - Modified polypropylene-based film, preparation method and application thereof

CN122011592ACN 122011592 ACN122011592 ACN 122011592ACN-122011592-A

Abstract

The scheme belongs to the technical field of composite current collector base films, and particularly relates to a modified polypropylene base film, a preparation method and application thereof, wherein the modified polypropylene base film comprises polypropylene resin, modified silicon dioxide, modified maleic anhydride grafted polypropylene, a slipping agent, an antioxidant and a nucleating agent, the modified silicon dioxide is obtained by performing ring-opening grafting reaction on silicon dioxide treated by a silane coupling agent KH560 and imidazole diol compound A, and the modified maleic anhydride grafted polypropylene is obtained by mixing maleic anhydride and compound B and then performing melt extrusion on the mixture and PP. According to the invention, imidazole functionalized silica and imidazole modified maleic anhydride grafted polypropylene are introduced into the PP matrix, so that double enrichment of imidazole groups on the matrix film body and the surface is realized, the binding force of a metal layer is improved, the peeling strength is improved, the compatibility between components can be improved more effectively, phase separation is avoided, balance between rigidity and toughness is realized, and the thickness uniformity and the surface flatness of the film are ensured.

Inventors

  • WANG RUNXIAO
  • WANG FENG
  • ZHUANG ZHI
  • HUANG HAN
  • LI JUN
  • WANG XIAOJUN
  • CHEN HUAIYU

Assignees

  • 扬州博恒新能源材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260410

Claims (9)

  1. 1. The modified polypropylene-based film is characterized by comprising the following components in parts by weight: 100 parts of polypropylene resin, 5-12 parts of modified silicon dioxide, 3-8 parts of modified maleic anhydride grafted polypropylene, 0.1-0.5 part of slipping agent, 0.3-0.8 part of antioxidant and 0.5-1 part of nucleating agent, The modified silicon dioxide is obtained by ring-opening grafting reaction of the treated nano silicon dioxide particles and a compound A by using a silane coupling agent KH 560; The modified maleic anhydride grafted polypropylene is obtained by mixing maleic anhydride, a compound B, an initiator and polypropylene resin and then carrying out melt extrusion; Compound A Compound B 。
  2. 2. The modified polypropylene-based film according to claim 1, wherein the modified silica is produced by the following process: Dispersing nano silicon dioxide particles in absolute ethyl alcohol by ultrasonic, adding a silane coupling agent KH560, raising the temperature, carrying out reflux reaction for 8 hours, centrifuging after the reaction is finished, washing with absolute ethyl alcohol, drying for standby, dispersing the dried solid in absolute ethyl alcohol again, adding a compound A, stirring and reacting for 8-12 hours at 70-90 ℃, centrifuging after the reaction is finished, washing with ethanol for 3-5 times, and vacuum drying at 60-80 ℃ to constant weight to obtain the imidazolyl functionalized modified silicon dioxide.
  3. 3. The modified polypropylene-based film according to claim 1, wherein the modified maleic anhydride grafted polypropylene is prepared by the following process: And (3) uniformly mixing polypropylene resin, maleic anhydride, a compound B and an initiator BPO, adding the mixture into a double-screw extruder, performing melt grafting reaction at 180-220 ℃, extruding, cooling and granulating to obtain modified maleic anhydride grafted polypropylene containing imidazole groups.
  4. 4. The modified polypropylene-based film according to claim 3, wherein the mass ratio of the polypropylene resin, the maleic anhydride, the compound B and the initiator BPO is 20-50:0.7-1.2:0.8-1.3:0.01.
  5. 5. The modified polypropylene-based film according to claim 1, wherein the slip agent is erucamide or oleamide.
  6. 6. The modified polypropylene-based film according to claim 1, wherein the antioxidant is at least one of antioxidant 1010, antioxidant 1076, and antioxidant 168.
  7. 7. The modified polypropylene-based film according to claim 1, wherein the nucleating agent is one selected from the group consisting of calcium carbonate whiskers, alumina, zeolite.
  8. 8. The method for producing a modified polypropylene-based film according to any one of claims 1 to 7, comprising the steps of: 1) Weighing polypropylene resin, modified silicon dioxide, modified maleic anhydride grafted polypropylene, a slipping agent, an antioxidant and a nucleating agent according to parts by weight, and uniformly mixing in a high-speed mixer to obtain a mixed material; 2) Adding the mixed material obtained in the step 1) into a double-screw extruder, carrying out melt blending extrusion at 190-230 ℃, casting the mixed material onto a cooling roller through a die head, and cooling a cast sheet; 3) Carrying out biaxial stretching on the cast sheet obtained in the step 2), and carrying out longitudinal stretching at 130-150 ℃ and stretching multiplying power of 4-6 times, and then carrying out transverse stretching at 150-170 ℃ and stretching multiplying power of 6-10 times; 4) And (3) carrying out heat setting treatment on the biaxially oriented film at 140-160 ℃ for 30-60 s, cooling, traction and rolling to obtain the modified polypropylene base film.
  9. 9. Use of the modified polypropylene-based film according to any one of claims 1 to 7 for the preparation of a composite current collector.

Description

Modified polypropylene-based film, preparation method and application thereof Technical Field The invention relates to the technical field of composite current collector base films, in particular to a modified polypropylene base film, a preparation method and application thereof. Background The polypropylene (PP) film has the advantages of low density, good chemical corrosion resistance, low cost and the like, and is widely applied to the fields of food packaging, medical packaging, production and conveying pipelines, textiles, electronic components and the like. The composite current collector is a novel current collector material used in energy storage devices such as lithium ion batteries and the like, and is generally formed by compounding a metal layer (such as aluminum and copper) with a high polymer base material. PP films are widely used as a base film material for composite current collectors due to their light weight and chemical inertness. After the composite material is compounded with the metal layer, the conductivity of the metal is reserved, the weight is reduced, and the safety and the energy density of the battery are improved. However, the PP film has relatively poor impact resistance and temperature resistance, and when the composite current collector is prepared, the base film may be wrinkled and deformed, or lose shape stability under high pressure and high temperature environment, and the yield of the finished product is affected. In addition, the surface energy of the PP film is low, the adhesion between the metal layer and the PP base film is easy to be insufficient, so that the metal layer is easy to fall off or peel in subsequent processing (such as winding and bending), and the service life and the safety of the battery are seriously affected. In order to improve the performance of the PP film and enable the PP film to be better applied to a composite current collector, the current mainstream technology mainly adopts two approaches, namely adding inorganic fillers (such as talcum powder, calcium carbonate, silicon dioxide and the like) and blending with other polymers. However, direct addition of either inorganic fillers or organic polymers can cause other drawbacks. The inorganic filler is introduced in a large amount, so that the rigidity and the heat resistance of the film can be effectively improved, but the toughness of the film is obviously reduced, the density is increased, the brittle failure problem is easy to occur, and when the film is blended with the polar polymer, the phase separation phenomenon is often caused by insufficient compatibility, macroscopic defects are formed, and the comprehensive performance of the material is weakened. Disclosure of Invention Aiming at the defects in the prior art, the invention designs the imidazole-based functionalized modified silicon dioxide and the imidazole-modified polymaleic anhydride grafted polypropylene, which can effectively improve the comprehensive performance of the polypropylene film. In order to achieve the above purpose, the present invention provides the following technical solutions: the modified polypropylene-based film comprises the following components in parts by weight: 100 parts of polypropylene resin, 5-12 parts of modified silicon dioxide, 3-8 parts of modified maleic anhydride grafted polypropylene, 0.1-0.5 part of slipping agent, 0.3-0.8 part of antioxidant and 0.5-1 part of nucleating agent, The modified silicon dioxide is obtained by ring-opening grafting reaction of the treated nano silicon dioxide particles and a compound A by using a silane coupling agent KH 560; the modified maleic anhydride grafted polypropylene is obtained by mixing maleic anhydride, a compound B, an initiator and polypropylene and then carrying out melt extrusion; Compound A Compound B。 Further, the preparation process of the modified silicon dioxide comprises the following steps: Dispersing nano silicon dioxide particles in absolute ethyl alcohol by ultrasonic, adding a silane coupling agent KH560, raising the temperature, carrying out reflux reaction for 8 hours, centrifuging after the reaction is finished, washing with absolute ethyl alcohol, drying for standby, dispersing the dried solid in absolute ethyl alcohol again, adding a compound A, stirring and reacting for 8-12 hours at 70-90 ℃, centrifuging after the reaction is finished, washing with ethanol for 3-5 times, and vacuum drying at 60-80 ℃ to constant weight to obtain the imidazolyl functionalized modified silicon dioxide. Further, the preparation process of the maleic anhydride grafted polypropylene comprises the following steps: And (3) uniformly mixing polypropylene resin, maleic anhydride, a compound B and an initiator BPO, adding the mixture into a double-screw extruder, performing melt grafting reaction at 180-220 ℃, extruding, cooling and granulating to obtain modified maleic anhydride grafted polypropylene containing imidazole groups. Further, the mass ratio of