Preparation method and production process of composite foil and corresponding composite foil

Abstract

The invention discloses a preparation method and a production process of a composite foil and the corresponding composite foil. The preparation method comprises the following steps: A0, pretreatment: at least carrying out chemical micro-etching on the surface of a film substrate layer; a1, a foil layer is generated, specifically, the cathode roller is immersed in the electrolyte to form the foil layer; a2, compounding: compounding the base material layer obtained in the step A0 with the foil layer obtained in the step A1. The method is convenient to implement, simple to operate, less in required flow, high in efficiency and convenient for realizing mass production; and the cost required by the compounding process is low. The defects of an existing treatment mode are overcome by creatively utilizing chemical reagent treatment, corona treatment does not need to be carried out on the ultrathin film base material layer, the adhesion is enhanced by adopting chemical micro-etching pretreatment instead of corona treatment, and the mechanical performance is compensated based on the chemical micro-etching process. The composite foil / composite current collector prepared on the basis of the production process has excellent composite stability and is not prone to falling off, and the mechanical strength including the tensile strength or the ductility is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of composite foil production, and more specifically, to a preparation method, production process of a composite foil, and the corresponding composite foil. Background Art

[0002] Composite foils such as composite current collectors can take into account energy density, safety, and battery cost, and have been applied as lithium battery materials in new energy, energy storage and other fields. In the currently common production methods of composite foils, such as the production of composite copper foils, it is common to use methods such as chemical vapor deposition and magnetron sputtering to deposit a metal foil layer on a substrate layer. Although such production methods can obtain composite current collectors, the operation of such production methods is difficult, there are many factors limiting the efficiency, and it is difficult to achieve mass production; moreover, the corresponding produced composite foils may still have problems such as insufficient adhesion stability, uneven lamination, or insufficient mechanical properties.

[0003] Therefore, there is an urgent need in the prior art for a new preparation method or production process of composite foils, which simplifies the production process, is convenient for mass production, and can obtain composite foils with excellent quality. Summary of the Invention

[0004] The present invention aims to overcome at least one of the above-mentioned deficiencies in the prior art, and provides a preparation method, production process of a composite current collector, and the corresponding composite current collector, which simplifies the production process, is convenient for mass production, and can obtain a composite current collector with excellent quality.

[0005] The technical solution adopted by the present invention is a method for preparing a composite foil, which includes the following steps: A0. Pretreatment: Chemically micro-etch at least the surface of the thin film substrate layer; A1. Generating a foil layer: Immerse the cathode roller in the electrolyte to form a foil layer; A2. Lamination: Laminate the substrate layer obtained in A0 with the foil layer obtained in A1.

[0006] Those skilled in the art should understand that at least steps A0 and A1 can be carried out simultaneously, and when A2 has started to be executed, A0, A1, and A2 can also continue to be carried out simultaneously, etc. Further, the composite foil includes a composite current collector with foil layers laminated on both sides of a substrate layer, and also includes a single-sided composite foil with a foil layer laminated on one side. In this application, a chemical micro-etching method is used to enhance the adhesion performance of the surface of the substrate layer, avoiding the decline in mechanical properties caused by methods such as corona treatment. The foil layer is generated separately, and then the substrate layer with excellent adhesion on the surface is laminated with the foil layer. The lamination includes adhesion, and thus the corresponding composite foil is obtained. The surface treatment of the substrate layer and the generation of the foil layer in this application are relatively independent, facilitating separate treatment and maintenance, and the corresponding process flow is also relatively stable; then through the lamination step, the substrate layer and the foil layer are laminated. Compared with common methods such as magnetron sputtering combined with evaporation to deposit a copper layer on the substrate layer, the overall production process of this application is simpler, easier to operate, enables mass production, and can effectively reduce production costs including multiple links such as equipment costs and processing costs. It should be noted that the composite foil obtained by the composite foil generation process of this application has multiple advantages such as stable lamination and high safety; compared with traditional methods such as corona treatment, the chemical micro-etching can control the etching depth, achieve nano-scale etching, and it is also convenient to compensate for mechanical properties by using the chemical etching method; the chemical micro-etching can improve the lamination strength between the substrate layer and the foil layer, making the composite foil not easy to fall off, and ensuring that the fracture strength and elongation rate of the substrate layer are not affected, thereby enabling the overall composite foil to have excellent mechanical properties, including tensile strength, elongation rate, etc., and improving the safety of the corresponding composite foil.

[0007] Further, the adhesion performance at least includes the dyne value, roughness, etc. The mechanical properties at least include tensile strength and elongation rate.

[0008] Further, step A0 specifically includes: A01. Apply a chemical treatment agent to the surface of the thin film substrate and carry out chemical micro-etching; A02. Remove the remaining components that no longer react; the components that no longer react include components such as water.

[0009] Further, step A0 also includes: A03. Coat a glue solution on the surface of the thin film substrate layer after chemical micro-etching to form a glue layer.

[0010] Further, step A0 also includes: A04. Cover a release film on at least one side of the glue layer; and before the substrate layer is sent to step A2 for lamination, peel off the release film on the side of the substrate layer for lamination with the foil layer.

[0011] Another object of the present invention is to provide a composite foil production process, including the following steps: S1. Unwind the base material layer to the laminating device; the surface of the base material layer is at least treated by chemical micro-etching; S2. Immerse the cathode roller in the electrolyte to form a foil layer; S3. The laminating device laminates the base material layer and the foil layer on the cathode roller for compounding, and guides the compounded foil away from the surface of the cathode roller; S4. Wind up the compounded foil.

[0012] Furthermore, during the unwinding process, the unwinding speed and / or deviation correction are adjusted in real time according to the tension of the base material layer; the unwinding and winding are coordinated to maintain the stretched state of the base material layer, so that the base material layer and the foil layer can be smoothly laminated and compounded; the quality of the compounded foil is improved. Deviation correction in real time according to the tension of the downstream base material layer is beneficial to timely overcome the roller deviation that may be caused by mechanical errors or roller running fluctuations during the unwinding process and maintain a stable production state.

[0013] Furthermore, the surface of the base material layer is micro-etched by applying a chemical treatment agent; the action thickness of the chemical micro-etching ≤ 1μm; the action thickness of the chemical micro-etching is the depth of the deepest etching position of the chemical micro-etching. Furthermore, the chemical micro-etching includes an etching depth range of 10nm - 1μm. Micro-etching the surface of the base material layer can achieve the improvement of the surface performance of the nano-level base material layer. The surface performance includes roughness, surface tension, etc., and the surface adhesion is improved; it is convenient to be compounded with other layer structures, especially with the metal layer, and a stable compound state is maintained. At the same time, compared with methods such as corona treatment, the loss of the mechanical strength of the base material layer by micro-etching is small. Micro-etching only acts on the surface micro-thickness and does not penetrate and damage the internal structure, so that while the surface performance of the base material layer is improved, the obvious influence on the mechanical strength can be avoided. And while the surface of the base material layer can be changed by using the micro-etching treatment agent, the mechanical properties can be compensated; the quality and use effect of the corresponding compounded foil are improved.

[0014] Further, the substrate layer includes PET film, PP film, PI film, PE film, PVC film, PBT film, PC film, PS film, ABS film, PA film, PASF film, PVDF film, PEDOT film, PANI film, and PPy film; that is, it includes the films corresponding to PET (polyethylene terephthalate), pp (polypropylene), PI (polyimide), PE (polyethylene), PVC (polyvinyl chloride), PBT (polybutylene terephthalate), PC (polycarbonate), PS (polystyrene), ABS (ternary copolymer of acrylonitrile (A)-butadiene (B)-styrene (S)), PA (polyamide), PASF (polyarylsulfone), PVDF (polyvinylidene fluoride), PEDOT (poly(3,4-ethylenedioxythiophene)), PANI (polyaniline), and PPy (polypyrrole). The thickness range of the substrate layer is 1.5~10μm; further, the thickness range of the substrate layer is 1.5~6μm. The foil layer includes at least copper foil; further, the thickness range of the foil is 0.8~10μm; furthermore, the thickness range of the foil is 0.8~3.5μm.

[0015] Further, in step S3, the foil layer is located on the cathode roller, with the cathode roller surface as the support surface. During the lamination process, the substrate layer is laminated on the foil layer, and in the production direction, there are at least two downward laminations against the cathode roller, for example, at least two consecutive and continuous downward laminations against the cathode roller, including the initial lamination and the final lamination, and the downward pressure F1 of the initial lamination > the downward pressure F2 of the final lamination. Furthermore, in the production direction, there are at least three downward laminations against the cathode roller, including the initial lamination, the transition lamination, and the final lamination, and the downward pressure F1 of the initial lamination > the downward pressure F2 of the final lamination; the downward pressure F1 of the initial lamination > the downward pressure F3 of the transition lamination; and / or, the downward pressure F1 of the initial lamination > the downward pressure F3 of the transition lamination > the downward pressure F2 of the final lamination, and the downward pressures of the initial lamination, the transition lamination, and the final lamination decrease in sequence, and the decreasing ratio range is 3%~20%; that is, F1×3%<F1 - F3 < F1×20%, F3×3%<F3 - F2 < F3×20%. Furthermore, the decreasing ratio range is 5%~15%, F1×5%<F1 - F3 < F1×15%, F3×5%<F3 - F2 < F3×15%. Further, the magnitudes of F1, F2, and F3 are in the range of 0.1N / in~10N / in (0.1N / inch~10N / inch). The initial lamination, the transition lamination, and the final lamination can be achieved by the downward pressure of three rollers arranged in sequence. This process is beneficial for full lamination and reduces defects such as air gaps and wrinkles.

[0016] Further, step S1 includes: S11, unreeling the substrate layer to the chemical micro-etching area, applying a chemical treatment agent on the surface of the substrate layer for chemical micro-etching; S12, transporting the film substrate layer that has undergone chemical micro-etching to a laminating device.

[0017] And the chemical treatment agent is applied on the surface of the substrate layer by at least roll coating, spraying and / or dipping; Further, in step S11, the chemical treatment agent micro-etches the film for 5 - 20 s.

[0018] Further, the chemical treatment agent contains component A: acrylic resin; component B: silane compound; component C: etching component; and the ratio of component A, component B, and component C is (5 - 10)∶(10 - 30)∶(0.1 - 10); Further, the chemical treatment agent also contains component D: glacial acetic acid, and the ratio of component A, component B, component C, and component D is (5 - 10)∶(10 - 30)∶(0.1 - 10)∶(0.5 - 3); Further, it also contains component E: wetting agent, and the ratio of component A, component B, component C, component D, and component E is (5 - 10)∶(10 - 30)∶(0.1 - 10)∶(0.5 - 3)∶(0.1 - 0.5). Further, an appropriate amount of water component is also included. Further, component B silane compound includes: amino silane and / or its oligomer, and / or, epoxy silane and / or its oligomer. Further, the mass concentration of the chemical treatment stock solution in the chemical treatment agent is 6% - 15%. When the chemical treatment stock solution includes components A, B, and C, the chemical treatment stock solution contains component A: acrylic resin 5 - 10%; component B: silane compound 10 - 30%; component C: etching component 0.1 - 10%; the balance is water; when component D or components D and E are included, then the aforementioned chemical treatment stock solution can be: component A 5%, component B 15%, component C 0.5%, component D 0.5% and make up to 100% water; or, component A 5%, component B 15%, component C 0.5%, component D 0.5%, component E 0.1% and make up to 100% water, etc.

[0019] Further, component B includes: amino silane and / or its oligomer, and, epoxy silane and / or its oligomer, and the ratio between amino silane and / or its oligomer and epoxy silane and / or its oligomer is 1:3 - 3:1. Even further, the ratio between amino silane and / or its oligomer and epoxy silane and / or its oligomer is 1:1 - 3:1. In component C, the etching component includes phosphate, peroxide and / or oxidizing high-valent metal ions. The molecular weight of the acrylic resin in component A is 3000 - 20000; the particle size of the acrylic resin in component A is 0.05 - 0.2 μm.

[0020] The acrylic resin includes its polymers, such as polyacrylic acid, hydroxy acrylic resin, poly(methyl acrylate) (PMA), poly(ethyl acrylate) (PEA), or derivatives thereof, such as acrylate esters, poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA), or derivatives thereof, such as methacrylate esters, or maleic acid-acrylic acid copolymer, but not limited thereto; specifically, the acrylic resin can be a commercially available acrylic resin, polyacrylic acid emulsion, acrylic polymer, such as Mitsubishi MB-2595 acrylic resin, Boxing B-30 acrylic resin, Nanjing Gutian 445N acrylic polymer, etc.; the maleic acid-acrylic acid copolymer can be the product 479N maleic acid-acrylic acid copolymer sold by Nanjing Gutian Chemical Industry, or a type of maleic acid-acrylic acid copolymer often used as a water treatment agent or dispersant, such as the maleic acid-acrylic acid copolymer sold by Shandong Taihe Science & Technology Co., Ltd. as a water treatment agent (CAS No. 26677-99-6), or the maleic acid-acrylic acid copolymer sold by BASF as a dispersant (Sokalan CP9); the polyacrylic acid emulsion can be the product sold by Runchang Chemical Industry, such as Runchang Chemical Industry 6069 polyacrylic acid emulsion. The amino silane, amino silane oligomer, epoxy silane, and epoxy silane oligomer can all be products of the prior art. For example, the amino silane oligomer can be commercially available products such as γ-aminopropylmethyldiethoxysilane (KH-902), Crosile 8150, Crosile 5203, USi-O1302 amino silane oligomer, QX-1250 amino silane oligomer, Jinrunna KRN8025, Quanxi Silicon Industry 1146 amino silane oligomer, Evonik Dynasylan 1146, and Evonik Dynasylan SIVO 260. The epoxy silane oligomer can be commercially available products such as USi-O2301 from Nanjing Liansil Chemical Co., Ltd., SICO-OP200 from Shandong Sike New Materials Co., Ltd., etc. Further, the phosphate includes ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, potassium phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, sodium phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, ammonium phosphate, calcium phosphate, lithium phosphate, and N-butylpyridinium hexafluorophosphate. Further, the peroxide includes hydrogen peroxide, ammonium persulfate, potassium persulfate, benzoyl peroxide, tert-butyl peroxybenzoate, methyl ethyl ketone peroxide, ethyl peroxybenzene, 4,4′-dibenzoyl peroxide, sodium bisulfate persulfate, potassium bisulfate persulfate, calcium bisulfate persulfate, sodium peroxide, calcium peroxide, potassium peroxide, and organic peroxides. Further, the high-valent metal ions with oxidizing properties include metal ions with a valence of +2 or higher.It can be selected from metal ions with a valence state of +2 or above, specifically including Fe3+, V2+, V3+, V4+, V5+, Cr6+. Further, the high-valence metal ions with oxidizing properties can exist in the form of compounds combined with other ions. Further, the E-component wetting agent includes fluorine-containing surface wetting agents, such as the prior art FC-4430 (fluorosurfactant FC-4430), etc.

[0021] Further, between steps S11 and S12, there are also included: step S11', squeezing, blowing dry, and / or drying treatments. Further, after applying the chemical treatment agent for 5 to 20 s, the substrate layer is squeezed, blown dry, and / or dried to remove components such as water that no longer continue to act.

[0022] Further, step S12 includes: S121, coating a glue solution on the surface of the chemically micro-etched thin film substrate layer to form a glue layer; S122, transporting the chemically micro-etched thin film substrate layer with a glue layer on its surface to a lamination device; further, after surface coating the glue solution, pre-curing is performed to form a glue layer; further, the glue solution is coated to form a glue layer with a thickness of 0.5 to 4 μm. Further still, after coating the glue solution, pre-curing is performed at a temperature of 80 to 90 °C to gel and shape the glue layer. In order to fully exert the effect of the glue layer, it can also be further cured in the temperature range of 50 to 90 °C after lamination.

[0023] Further, in step S1, the substrate layer is a substrate layer that has been at least chemically micro-etched on the surface, and at least one side of the substrate layer is covered with a glue layer.

[0024] Further, a release film is covered on the glue layer; it also includes the step: before performing step S3, peeling off the release film of the glue layer on the side of the substrate layer for lamination with the foil layer.

[0025] Further, steps S1 to S4 achieve the lamination of one side of the substrate layer with the foil layer; repeating steps S1 to S4 to obtain a composite foil with both sides of the substrate layer laminated with the foil layer; or, in step S1, both sides of the substrate layer are at least chemically micro-etched; step S3 achieves the lamination of one side of the substrate layer with the foil layer, and at least repeating step S3 to obtain a composite foil with both sides of the substrate layer laminated with the foil layer.

[0026] Further, between performing the first S1 to S4 and performing the second S1 to S4, there is also included the step: transferring the single-sided composite foil wound up to the unwinding position and unwinding it so that the unlaminated side faces the foil layer on the surface of the cathode roller when it is opposite to the cathode roller.

[0027] Further, a post-treatment step is also provided between steps S3 and S4. The post-treatment step includes: passivating the composite foil; and / or, cleaning the surface of the foil layer of the composite foil; and / or, hot-air drying and / or drying the composite layer. Further, after the passivation treatment, the step of extruding the residual passivation liquid on the surface of the composite foil is also included.

[0028] Another object of the present invention is to provide a composite foil prepared by the foregoing composite foil preparation method or the foregoing composite foil production process. Further, the total thickness range of the composite foil is 3 to 12 μm. More specifically, the total thickness range of the composite foil is 6 to 12 μm.

[0029] Another object of the present invention is to provide an electronic device, including: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the foregoing preparation method or the foregoing composite foil production process.

[0030] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, and the computer program is executed by a processor to implement the foregoing preparation method or the foregoing composite foil production process.

[0031] Compared with the prior art, the beneficial effects of the present application are as follows: The composite foil production process of the present application is easy to implement, simple to operate, requires fewer processes, has high efficiency, and is convenient for mass production. It is significantly different from common "one-step methods", "two-step methods", etc., and does not require a combination of complex magnetron sputtering, evaporation coating and other methods. Only pretreatment and generation are required respectively, and viscous lamination can be used; the cost required for the lamination process is low. Moreover, the production process has strong compatibility, and additional processing devices can be added according to requirements. It should be noted that the composite foil production process of the present application combines the characteristics of the production process of the present application, adopts a processing method mainly based on chemical treatment throughout the process, and reduces the threshold of production equipment; and creatively uses chemical reagent treatment to improve the deficiencies of the existing treatment methods. It is not necessary to perform corona treatment on the ultra-thin film substrate layer, but chemical micro-etching is used for pretreatment to replace corona treatment to enhance adhesion, and the mechanical properties are compensated based on the chemical micro-etching process; the mechanical properties of the substrate layer after pretreatment are not reduced compared with those before pretreatment. The composite foil / composite current collector prepared based on the production process of the present application has excellent composite stability, is not easy to fall off, and the mechanical strength including tensile strength or elongation rate is guaranteed, and it is beneficial to the mechanical properties of the substrate layer and the foil layer after lamination to be significantly greater than the mechanical properties of the simple superposition of the substrate layer and the foil layer. Description of the Drawings

[0032] Figure 1 This is a schematic diagram of the processing process of the thin film substrate of this application.

[0033] Figure 2 This is the schematic diagram (1) of the production process of the composite foil in Embodiment 3 of this application.

[0034] Figure 3 This is the schematic diagram (2) of the production process of the composite foil in Embodiment 3 of this application.

[0035] Figure 4 This is the schematic diagram of the production process of the composite foil in Embodiment 4 of this application.

[0036] Description of the drawings: Thin film substrate layer processing system 100, chemical micro-etching device 110, residue removal device 120, unwinding device 1100, laminating device 1200, pressure roller combination 1210, guiding roller 1220, copper foil making machine 1300, cathode roller 1310, electrolytic cell 1320, passivation device 1400, winding device 1500, glue coating device 1600, pre-curing device 1700, peeling component 1800. Detailed implementation manners

[0037] The drawings of the present invention are only for illustrative purposes and should not be construed as a limitation to the present invention. To better illustrate the following embodiments, some components in the drawings are omitted, enlarged or reduced, which do not represent the dimensions of the actual products; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0038] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings and specific implementation manners. However, those skilled in the art will understand that the following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. For those conditions not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase. Embodiment 1

[0039] This embodiment discloses a method for preparing a composite foil, including the following steps: A0. Pretreatment: Chemically micro-etch at least the surface of the thin film substrate layer; A1. Generating a foil layer: Immerse the cathode roller in the electrolyte to form a foil layer; A2. Laminating: Laminate the substrate layer obtained in A0 with the foil layer obtained in A1.

[0040] Those skilled in the art should understand that steps A0, A1 and / or A2 can be carried out simultaneously. The composite foil includes a composite current collector with foil layers laminated on both sides of a substrate layer, and also includes a single-sided composite foil with a foil layer laminated on one side only.

[0041] Step A0 specifically includes: A01. Applying a chemical treatment agent to the surface of the thin film substrate and performing chemical micro-etching; A02. Removing the residual components that no longer react; the components that no longer react include components such as water.

[0042] In this embodiment, step A0 further includes: A03. Coating an adhesive solution on the surface of the chemically micro-etched thin film substrate layer to form an adhesive layer.

[0043] That is, step A0 can directly obtain a chemically micro-etched substrate layer (when the substrate layer can be directly laminated with the foil layer), and then enter the lamination process; or it can also be coated with an adhesive layer online after chemical micro-etching, and then enter the lamination process. Example 2

[0044] The difference between this embodiment and Example 1 is only that step A0 further includes: A04. Covering a release film on at least one side of the adhesive layer; and peeling off the release film on the side of the substrate layer for lamination with the foil layer before the substrate layer is sent to step A2 for lamination. That is, the difference from Example 1 is that this embodiment can also be produced in an offline cooperation mode, that is, in step A0, a chemically micro-etched thin film is obtained, and after covering an adhesive layer, a release film is covered for standby; when lamination is required, then enter the lamination process, and control the peeling of the corresponding release film of the substrate layer before lamination.

[0045] Then, a comparison is made between the online method of Example 1 (Group A), the composite foil obtained based on the micro-etched thin film in this embodiment (Group B), and the composite foil obtained based on the corona-treated thin film (Group C). Both Example 1 and this embodiment use an adhesive layer. The specific process of the composite foil obtained based on the corona-treated thin film is different from that of Example 1 and this embodiment only in that the thin film is not micro-etched, but corona-treated; specifically, it includes adjusting the parameters of the corona treatment machine so that the surface dyne value of the thin film reaches 34-36.

[0046] In this embodiment, the thin film uses a 3.6 μm thick PP film, the metal foil layer uses a 1.2 μm thick copper foil, and the composite copper foil is a composite copper foil with adhesive layers and foil layers symmetrically distributed on both sides of the thin film. The total thickness of the obtained composite copper foil is between 8.6 ± 0.1 μm.

[0047] The following test results are obtained: Tensile strength (longitudinal / Mpa) Tensile strength (transverse / Mpa) Elongation (longitudinal / %) Elongation (transverse / %) Peel strength N / 25mm Group A 197 177 3.4 3.2 5.275 Group B 206 187 3.6 3.3 5.322 Group C 161 154 2.6 2.3 3.825

[0048] The results show that in this embodiment, the comprehensive performance of Group B is better than that of Group A, and there are significant differences in the performance between Groups A and B and Group C. On the one hand, during the overall generation process of the composite foil, since Group B is not fully on-line, at least the treatment of the film before lamination is off-line treatment. This off-line treatment method is conducive to independently controlling the film processing process, significantly improving its performance in subsequent lamination with the foil layer. Based on the micro-etching and other processes of this application, Group A also has certain excellent comprehensive performance. However, since its processing process is fully on-line, it is not easy to improve and adjust the film separately, and the processing effect is limited by the length of the production line, production speed, etc. Therefore, the final formed composite foil is slightly weaker than Group B in some performances. In Group C, although the corona-treated film improves the lamination between the film and the foil layer, it causes great loss to the mechanical properties of the film, at least directly affecting the mechanical properties of the overall composite foil. The overall performance is weaker than that of Group A and Group B, and the difference is relatively significant. Example 3

[0049] As Figure 2 shown, this embodiment discloses a production process of a composite foil, including the following steps: S1. The unwinding device 1100 unwinds the base material layer to the lamination device 1200; the surface of the base material layer is at least treated by chemical micro-etching; S2. The cathode roller 1310 is immersed in the electrolyte in the electrolytic cell 1320 to form a foil layer; S3. The lamination device 1200 laminates the base material layer and the foil layer on the cathode roller 1310 and guides the laminated composite foil away from the surface of the cathode roller 1310; S4. The rewinding device 1500 rewinds the laminated composite foil.

[0050] During the unwinding process, the unwinding speed and / or deviation correction are adjusted in real time according to the tension of the base material layer; the unwinding and rewinding are coordinated to maintain the stretched state of the base material layer, so that the base material layer and the foil layer can be flatly laminated; the quality of the composite foil is improved.

[0051] In this embodiment, the surface of the base material layer is micro-etched by applying a chemical treatment agent; the base material layer includes PET film, PP film, PI film, PE film, PVC film, PBT film, PC film, PS film, ABS film, PA film, PASF film, PVDF film, PEDOT film, PANI film, and PPy film. The thickness range of the base material layer is 1.5 - 10 μm, specifically, it can be 1.5 - 6 μm. The foil layer at least includes copper foil; the thickness range of the foil is 0.8 - 10 μm; specifically, it can be 0.8 - 3.5 μm.

[0052] Step S1 includes: S11. The unwinding device 1100 unwinds the substrate layer to the chemical micro-etching area, and the chemical micro-etching device 110 applies a chemical treatment agent to the surface of the substrate layer for chemical micro-etching; S12. The film substrate layer that has undergone chemical micro-etching is transported to the laminating device 1200. And the chemical micro-etching device 110 applies the chemical treatment agent to the surface of the substrate layer at least by roll coating, spraying, and / or immersion, as Figure 1 shown; in this embodiment, in step S11, the chemical treatment agent micro-etches the film for 5 to 20 s.

[0053] The chemical treatment agent used in this embodiment includes component A: acrylic resin; component B: silane compound; component C: etching component; and the ratio of component A, component B, and component C is (5 - 10):(10 - 30):(0.1 - 10); further, the chemical treatment agent further includes component D: glacial acetic acid, and the ratio of component A, component B, component C, and component D is (5 - 10):(10 - 30):(0.1 - 10):(0.5 - 3); further, it further includes component E: wetting agent, and the ratio of component A, component B, component C, component D, and component E is (5 - 10):(10 - 30):(0.1 - 10):(0.5 - 3):(0.1 - 0.5). Further, an appropriate amount of water component is also included. Further, component B silane compound includes: amino silane and / or its oligomer, and / or, epoxy silane and / or its oligomer. Further still, the ratio of component A, component B, and component C is 5:15:(0.5 - 1). Further still, the mass concentration of the chemical treatment agent is 6% - 15%. When the chemical treatment stock solution includes components A, B, and C, the chemical treatment stock solution includes component A: acrylic resin 5 - 10%; component B: silane compound 10 - 30%; component C: etching component 0.1 - 10%; the balance is water; when component D is included and the ratio of component A, component B, component C, and component D is 5:15:0.5:0.5, or when components D and E are included and the ratio of component A, component B, component C, component D, and component E is 5:15:0.5:0.5:0.1, then the aforementioned chemical treatment stock solution can correspond to: component A 5%, component B 15%, component C 0.5%, component D 0.5% and make up 100% of water, or, component A 5%, component B 15%, component C 0.5%, component D 0.5%, component E 0.1% and make up 100% of water, etc.

[0054] Component B includes: aminosilane and / or its oligomer, and epoxy silane and / or its oligomer, and the ratio between aminosilane and / or its oligomer and epoxy silane and / or its oligomer is 1:3 to 3:1. Further, the ratio between aminosilane and / or its oligomer and epoxy silane and / or its oligomer is 3:1. The etching component in Component C includes phosphate, peroxide and / or oxidizing high-valent metal ions. The molecular weight of the acrylic resin in Component A is 3000 to 20000; the particle size of the acrylic resin in Component A is 0.05 to 0.2 μm. Further, the wetting agent in Component E includes fluorine-containing surface wetting agents, such as FC-4430 (fluorosurfactant FC-4430) in the prior art, etc.

[0055] Between step S11 and S12, there also includes: step S11’, squeezing, air drying and / or drying treatment, such as Figure 1 shown, drying is carried out through the residue removal device 120; the chemical micro-etching process and the residue removal process can be realized by the integrated thin film substrate layer processing system 100, such as Figure 1 shown. In this embodiment, that is, 5 to 20 s after applying the chemical treatment agent, the substrate layer is squeezed, air dried and / or dried to remove components such as water that no longer act.

[0056] Specifically, when it is necessary to improve the adhesion effect by means of the adhesive layer, such as Figure 3 shown, step S12 may include: S121, coating the adhesive liquid on the surface of the thin film substrate layer that has undergone chemical micro-etching through the coating device 1600 to form an adhesive layer; S122, transporting the thin film substrate layer that has undergone chemical micro-etching and has an adhesive layer on its surface to the lamination device 1200. In step S121, after the adhesive liquid is coated on the surface, pre-curing is carried out through the pre-curing device 1700 to form an adhesive layer; and in this embodiment, the adhesive liquid is coated to form an adhesive layer with a thickness of 0.5 to 4 μm. After the adhesive liquid is coated, it is pre-cured at a temperature of 80 to 90 °C to make the adhesive liquid layer gel and take shape. In order to fully exert the effect of the adhesive layer, it can also be further cured in the temperature range of 50 to 90 °C after lamination.

[0057] Specifically, in step S3, the foil layer is located on the cathode roller 1310 of the raw foil machine 1300, with the cathode roller surface as the support surface. During the lamination process, the base material layer is laminated onto the foil layer, and in the production direction, there are at least two downward lamination presses against the cathode roller 1310. For example, there are at least two consecutive and continuous stages of downward lamination presses against the cathode roller, including the initial press and the final press, and the downward press force F1 of the initial press > the downward press force F2 of the final press. Further, in the production direction, there are at least three downward lamination presses against the cathode roller 1310. For example, in the lamination device 1200 of this embodiment, the corresponding lamination is achieved through three pressure rollers of the pressure roller combination 1210, including the initial press, the transition press, and the final press, and the downward press force F1 of the initial press > the downward press force F2 of the final press; the downward press force F1 of the initial press > the downward press force F3 of the transition press; and / or, the downward press force F1 of the preliminary press > the downward press force F3 of the transition press > the downward press force F2 of the final press, and the downward press forces of the preliminary press, the transition press, and the final press decrease in sequence, and the decreasing ratio range is 3% - 20%; that is, F1×3% < F1 - F3 < F1×20%, F3×3% < F3 - F2 < F3×20%. Further, the decreasing ratio range is 5% - 15%, F1×5% < F1 - F3 < F1×15%, F3×5% < F3 - F2 < F3×15%. Further, the magnitudes of F1, F2, and F3 are in the range of 0.1 N / in - 10 N / in (0.1 N / inch - 10 N / inch). The preliminary press, the transition press, and the final press can be achieved by the downward pressure of three pressure rollers arranged in sequence. This process is beneficial to full lamination and reduces defects such as air gaps and wrinkles. After lamination by the pressure roller combination 1210, the composite foil material is also separated from the cathode roller 1310 through the separation roller 1220 in the lamination device 1200.

[0058] In this embodiment, steps S1 - S4 can simultaneously laminate both surfaces of the base material layer; however, if steps S1 - S4 in this embodiment can only achieve lamination of one side of the base material layer with the foil layer, then steps S1 - S4 can be repeated to obtain a composite foil material with both sides of the base material layer laminated with the foil layer; alternatively, both sides of the base material layer in step S1 are at least chemically micro-etched; step S3 realizes lamination of one side of the base material layer with the foil layer, then at least step S3 is repeated to obtain a composite foil material with both sides of the base material layer laminated with the foil layer.

[0059] And for the convenience of repeated execution, in this embodiment, between the first execution of S1 - S4 and the second execution of S1 - S4, the steps may further include: transferring the single-sided composite foil material wound up to the unwinding position, and when unwinding to face the cathode roller 1310, the unlaminated side faces the foil layer on the surface of the cathode roller 1310.

[0060] In order to improve the effect of the composite foil, in this embodiment, after the lamination, that is, a post-treatment step is further provided between steps S3 and S4. The post-treatment step includes: passivating the composite foil through a passivation device 1400 storing a passivation solution; after the passivation treatment, the steps further include: extruding the residual passivation solution on the surface of the composite foil; and / or, cleaning the surface of the foil layer of the composite foil; and / or, hot air drying and / or drying the composite foil. Example 4

[0061] This embodiment discloses a production process of a composite foil. The only difference from Example 3 is that in step S1, the substrate layer is a substrate layer that has been at least chemically micro-etched on the surface, and at least one side of the substrate layer is covered with an adhesive layer.

[0062] Specifically, a release film is further covered on the adhesive layer; the steps further include: before step S3 is executed, peeling off the release film of the adhesive layer on the side of the substrate layer for lamination with the foil layer through a peeling component 1800.

[0063] As Figure 4 shown, that is, this embodiment uses a processed thin film for production, and the processes of chemical micro-etching and applying glue to the thin film are offline processes. Example 5

[0064] This embodiment discloses a composite foil prepared by using the composite foil preparation method of the foregoing Example 1 or Example 2, or the composite foil production process of the foregoing Example 3 or Example 4. In this embodiment, the composite foil production process of the foregoing Example 3 or Example 4 is adopted. The thickness range of the composite foil is 3-12 μm; when both sides of the thin film are laminated, the total thickness range of the composite foil can be 6-12 μm. Example 6

[0065] In this embodiment, the test group composite foils are prepared by using the composite foil production processes of Example 3 (Group A1) and Example 4 (Group B1) respectively. Both Group A1 and Group B1 use an adhesive layer; and the pressing pressure of the pressing roller decreases in the production direction; at the same time, a control group is prepared. In the control group, the corona-treated thin film is used to replace the chemically micro-etched thin film of the present application. The corona treatment process is the same as that of Example 2. The adhesive layer is coated online. When moving to between the lamination device 1200 and the cathode roller 1310, the pressing roller of the lamination device 1200 directly presses the thin film onto the cathode roller 1310 (there is no difference in the pressing pressure of the pressing rollers in the same pressing roller combination 1210), and the lamination with the foil layer is carried out to obtain the control group composite foil. The thin film uses a 3.6-μm-thick PP thin film, and the metal foil layer uses a 1.2-μm-thick copper foil. The composite copper foil is a composite copper foil with adhesive layers and foil layers symmetrically distributed on both sides of the thin film. The total thickness range of the obtained composite copper foil is between 8.6 ± 0.1 μm.

[0066] Then, perform performance tests and comparisons on the composite foils of the experimental group and the control group; obtain the corresponding test results.

[0067] The results are shown in the following table: Tensile strength (longitudinal / Mpa) Tensile strength (transverse / Mpa) Elongation (longitudinal / %) Elongation (transverse / %) Peel strength N / 25mm Whether obvious wrinkles or air gaps were observed Group A1 195 173 3.5 3.2 5.125 None Group B1 213 186 3.6 3.3 5.475 None Control group 176 154 2.7 2.2 3.375 Yes

[0068] The results show that: The test results of Examples A1 and B1 and the control group in this embodiment are similar to those of Example 2. In terms of comprehensive performance, Group B1 is superior to Group A1, and Groups A1 and B1 are significantly superior to the control group. It should be noted that for the composite copper foil produced by the control group, obvious wrinkles and air gaps can be observed, and due to the poor bonding, its adhesion performance is significantly worse than that of Groups A1 and B1; its stability and safety are also significantly inferior to those of Groups A1 and B1. Example 7

[0069] This embodiment discloses an electronic device, including: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and when the instructions are executed by the at least one processor, the at least one processor is enabled to execute the preparation method or the composite foil production process as described above. Example 8

[0070] This embodiment discloses a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the preparation method or the composite foil production process as described above is implemented.

[0071] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solutions of the present invention, rather than limitations on the specific implementation manners of the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the claims of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a composite foil, characterized in that, It includes the following steps: A0. Pretreatment: Chemically micro-etch at least the surface of the thin film substrate layer; A1. Generating a foil layer: Immerse the cathode roller in the electrolyte to form a foil layer; A2. Laminating: Laminate the substrate layer obtained in A0 with the foil layer obtained in A1.

2. The method for preparing a composite foil according to claim 1, characterized in that, Step A0 specifically includes: A01. Apply a chemical treatment agent to the surface of the thin film substrate and perform chemical micro-etching; A02. Remove the remaining components that have not continued to react.

3. The method for preparing the composite foil according to claim 1 or 2, characterized in that, Step A0 further includes: A03. Coat an adhesive solution on the surface of the chemically micro-etched thin film substrate layer to form an adhesive layer.

4. The method for preparing a composite foil according to claim 3, characterized in that, Step A0 further includes: A04. Cover a release film on at least one side of the adhesive layer; And before the substrate layer is sent to step A2 for lamination, peel off the release film on the side of the substrate layer for laminating with the foil layer.

5. A production process for a composite foil, characterized in that, It includes the following steps: S1. Unwind the substrate layer to the laminating device; the surface of the substrate layer is at least chemically micro-etched; S2. Immerse the cathode roller in the electrolyte to form a foil layer; S3. The laminating device laminates the substrate layer with the foil layer on the cathode roller for lamination and guides the laminated foil away from the surface of the cathode roller; S4. Wind up the laminated foil.

6. The production process of the composite foil according to claim 5, characterized in that, Step S1 includes: S11. Unwind the substrate layer to the chemical micro-etching area, apply a chemical treatment agent to the surface of the substrate layer for chemical micro-etching; S12. Transfer the chemically micro-etched thin film substrate layer to the laminating device.

7. The production process of the composite foil according to claim 6, characterized in that, Between step S11 and S12, there is also included: step S11'. Perform squeezing, drying, and / or drying treatment.

8. The production process of the composite foil according to claim 6 or 7, characterized in that, Step S12 includes: S121. Coat an adhesive solution on the surface of the chemically micro-etched thin film substrate layer to form an adhesive layer; S122. Transfer the chemically micro-etched thin film substrate layer with an adhesive layer on its surface to the laminating device.

9. The production process of the composite foil according to claim 5, characterized in that, In step S1, the substrate layer is a substrate layer whose surface is at least chemically micro-etched, and at least one side of the substrate layer is covered with an adhesive layer.

10. The production process of the composite foil according to claim 9, characterized in that, A release film is covered on the adhesive layer; it also includes the step: before step S3 is executed, peel off the release film on the adhesive layer on the side of the substrate layer for laminating with the foil layer.

11. The production process of the composite foil according to any one of claims 5 to 10, characterized in that, Steps S1 to S4 achieve lamination of one side of the substrate layer with the foil layer; repeat steps S1 to S4 to obtain a composite foil with both sides of the substrate layer laminated with the foil layer; or, in step S1, both sides of the substrate layer are at least chemically micro-etched; step S3 achieves lamination of one side of the substrate layer with the foil layer, and at least repeat step S3 to obtain a composite foil with both sides of the substrate layer laminated with the foil layer.

12. A composite foil, characterized in that, It is prepared by using the method for preparing a composite foil according to any one of claims 1 to 4, or by using the production process of the composite foil according to claims 5 to 11.

13. An electronic device, characterized in that, It includes: At least one processor, and A memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the preparation method according to any one of claims 1 to 4 or the production process of the composite foil according to claims 5 to 11.

14. A computer-readable storage medium storing a computer program, characterized in that, The computer program is executed by the processor to implement the preparation method according to any one of claims 1 to 4 or the production process of the composite foil according to claims 5 to 11.

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