High-drawing aluminum-plastic film for soft-pack batteries and method for continuous batch production thereof

Abstract

The present disclosure provides a high-drawing aluminum-plastic film for soft-pack batteries and a method for continuous batch production thereof. The above method is to apply a modified polyester-type polyurethane glue mesh roller to an aluminum foil roll through a glue mesh roller; obtain aluminum foil A; the modified polyester-type polyurethane glue includes 40 to 55 parts of a polyester polyol main agent containing a hydroxyl end; 7 to 10 parts of a polyisocyanate curing agent, and 6 to 8 parts of a diluent. The nylon roll and the aluminum foil A are subjected to a first dry composite operation to obtain a nylon-aluminum foil composite film; the winding tension of the aluminum foil roll is controlled to match the winding tension of the nylon roll during the first dry composite operation. The polypropylene film and the nylon-aluminum foil composite film are subjected to a second dry composite operation and cut to obtain the aluminum-plastic film. The method can not only meet the high-drawing performance requirements, but also ensure the accuracy of the glue application amount; it also ensures that the separation force of the aluminum foil A and the nylon is small during the composite, so as to avoid the problems of curling and shrinkage caused by the difference in winding tension in continuous batch production.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic digital product production, and in particular to a high-deep-drawing aluminum-plastic film for soft-pack batteries and a method for continuous batch production thereof. Background Art

[0002] 3C digital products are a common type of electronic digital products. 3C digital products have built-in soft-pack lithium batteries, which can provide power for 3C digital products to ensure the normal operation of 3C digital products.

[0003] With the development of the market, consumers have higher requirements for 3C digital products, such as the requirement for 3C digital products to run longer. The problem of 3C digital products running longer can be solved by increasing the capacity of soft-pack lithium batteries.

[0004] However, when the capacity of soft-pack lithium batteries is increased, the diameter of soft-pack batteries becomes larger and larger, and the diameter of soft-pack batteries exceeds 7.5mm, which results in the need for traditional aluminum-plastic films to punch deeper holes in order to encapsulate soft-pack batteries with larger diameters. However, in actual applications, traditional aluminum-plastic films are prone to R corner damage during the punching process. For details, please refer to Figure 1 As a result, the current traditional aluminum-plastic film cannot meet the packaging and sealing requirements of soft-pack batteries with a diameter greater than 7.5mm.

[0005] In order to avoid the R-corner damage phenomenon that traditional aluminum-plastic film is prone to during the deep punching process, some scholars have conducted some in-depth discussions based on the R-corner damage phenomenon and found that the first places to be damaged during the deep punching process are the nylon and aluminum foil at the R-corner. At this time, the outer rubber layer connecting the nylon and aluminum foil plays a vital role. Therefore, a large number of scholars have focused on the outer rubber layer in their exploration of R-corner damage.

[0006] For example, Chinese patent document CN115160529B discloses an epoxy-modified polyurethane main resin and a single-component intrinsic hydrolysis-resistant and cooking-resistant aluminum-plastic film outer layer adhesive. In this way, by improving the flexibility, tear strength and adhesion of the outer layer, the problem of R corner damage easily occurring in traditional aluminum-plastic films during high-depth drawing processes is effectively solved.

[0007] However, in the production process of continuous batch dry lamination of aluminum-plastic film, the flexibility and adhesion of the outer rubber layer become higher, which is not conducive to winding, causing the nylon layer of the aluminum-plastic film to shrink easily during the winding process. For details, please refer to Figure 2 . Summary of the invention

[0008] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method that can meet the requirements of high-drawing performance and ensure the accuracy of the glue application amount; it is also conducive to the separation of the aluminum foil roll and the nylon roll during compounding, and it also ensures that the winding tension between the aluminum foil roll and the nylon roll is close, effectively avoiding the problem of nylon curling and shrinkage caused by the large difference in winding tension between the aluminum foil roll and the nylon roll in continuous batch production; the high-drawing aluminum-plastic film for soft-pack batteries and the continuous batch production method thereof are greatly reduced in production defective rate. .

[0009] The purpose of this disclosure is achieved through the following technical solutions:

[0010] A method for continuous batch production of high-drawing aluminum-plastic films for soft-pack batteries,

[0011] Place the aluminum foil roll and the nylon roll on the dry laminating machine respectively;

[0012] Feeding the aluminum foil of the aluminum foil roll into the gluing screen roller of the dry laminating machine;

[0013] The modified polyester polyurethane glue is applied to the aluminum foil by the glue screen roller to obtain aluminum foil A; wherein the modified polyester polyurethane glue comprises the following mass components:

[0014] 40 to 55 parts of a hydroxyl-terminated polyester polyol main agent;

[0015] 7 to 10 parts of polyisocyanate curing agent;

[0016] 6 to 8 parts of diluent;

[0017] Performing a first dry composite operation on the nylon of the nylon roll and the aluminum foil A to obtain a nylon-aluminum foil composite film; wherein the winding tension of the aluminum foil roll is controlled to match the winding tension of the nylon roll during the first dry composite operation;

[0018] Performing a second dry compounding operation on the polypropylene film and the nylon-aluminum foil composite film to obtain a nylon-aluminum foil-polypropylene film composite roll;

[0019] Performing a drying and aging operation on the nylon-aluminum foil-polypropylene film composite roll;

[0020] The nylon-aluminum foil-polypropylene film composite roll after drying and aging is cut to obtain the high-drawing aluminum-plastic film of the soft-pack battery.

[0021] In one embodiment, the winding tension during the first dry compounding operation is controlled to be 25kg to 32kg.

[0022] In one of the embodiments, in the step of feeding the aluminum foil of the aluminum foil roll into the gluing screen roller of the dry laminating machine, the unwinding tension of the aluminum foil roll is controlled to be smaller than the winding tension of the first dry laminating operation.

[0023] In one embodiment, the drying temperature of the first dry compounding operation is 90°C to 100°C.

[0024] In one embodiment, the diluent includes at least one of dimethyl carbonate, ethyl acetate, dimethyl carbonate and methyl acetate.

[0025] In one embodiment, the water content of the diluent does not exceed 300 ppm, and the alcohol content does not exceed 200 ppm.

[0026] In one embodiment, the polypropylene film and the nylon-aluminum foil composite film are subjected to a second dry composite operation using acid-modified polyolefin glue.

[0027] In one embodiment, the glue amount of the modified polyester polyurethane glue and the glue amount of the acid-modified polyolefin glue are (1.0-1.5): (2.0-2.5).

[0028] In one embodiment, after the step of placing the aluminum foil roll and the nylon roll on the dry laminating machine respectively, and before the step of feeding the aluminum foil of the aluminum foil roll into the gluing screen roller of the dry laminating machine, the following specific steps are also included:

[0029] Performing a surface pretreatment operation on the aluminum foil to obtain aluminum foil B;

[0030] The two sides of the aluminum foil B are treated with a surface modifier to form surface protection films on the two sides of the aluminum foil B.

[0031] A high-drawing aluminum-plastic film for soft-pack batteries is prepared by the method for continuous batch production of high-drawing aluminum-plastic films for soft-pack batteries described in any of the above embodiments.

[0032] Compared with the prior art, the present invention has at least the following advantages:

[0033] 1) The addition of 40 to 55 parts of a polyester polyol main agent containing a hydroxyl end, 7 to 10 parts of a polyisocyanate curing agent and 6 to 8 parts of a diluent can be mixed to obtain a modified polyester polyurethane glue with a suitable viscosity. On the premise of ensuring that the modified polyester polyurethane adhesive layer has strong toughness and softness, the peeling force between the aluminum foil and the nylon is improved, thereby improving the deep drawing performance of the aluminum-plastic film; effectively avoiding the phenomenon that the traditional aluminum-plastic film is prone to R corner damage during the high-depth drawing process, so as to better meet the packaging and sealing requirements of larger diameter soft-pack batteries, so as to better It can adapt to the market demand of electronic digital products; it can also ensure that the gluing wire roller can more comprehensively apply the modified polyester polyurethane glue mesh roller to the aluminum foil, thereby ensuring the accuracy of gluing; it is also conducive to the separation of the gluing wire roller and the aluminum foil after the gluing is completed, thereby ensuring that the separation force of the aluminum foil A and nylon is small when they are compounded, and effectively avoiding the phenomenon that the aluminum foil roll and the nylon roll are easy to shrink during the winding process due to the large separation force when the aluminum foil roll and the nylon roll are compounded. The defective rate of aluminum-plastic film production is reduced.

[0034] 2) By controlling the winding tension of the aluminum foil roll to match the winding tension of the nylon roll during the first dry composite operation, the winding tension between the aluminum foil roll and the nylon roll is ensured to be close, thereby effectively avoiding the problem of nylon curling and shrinkage caused by the large difference in winding tension between the aluminum foil roll and the nylon roll in continuous batch production, thereby ensuring that the high-drawing aluminum-plastic film of the soft-pack battery finally prepared has high flatness and does not shrink, further reducing the defective rate of aluminum-plastic film production.

[0035] 3) Since the polyester polyol main agent containing hydroxyl ends can react with the polyisocyanate curing agent to generate a polyester-type branched three-dimensional cross-linked polymer, and the generated polyester-type branched three-dimensional cross-linked polymer can well bond the aluminum foil and nylon together, the addition of ether bonds is effectively avoided, thereby solving the problem that the ether bonds in the outer rubber layer of the traditional aluminum-plastic film affect the adhesion between the aluminum foil and nylon, and avoiding the hardness of the traditional modified polyurethane glue caused by the addition of carbon nanotubes to increase and affect the deep punching performance of the aluminum-plastic film. It not only improves the adhesion between aluminum foil and nylon, but also ensures that the modified polyester polyurethane adhesive layer formed after the final cross-linking and curing has a high cohesive force, so as to ensure that the modified polyester polyurethane adhesive layer is strong, tough and soft, thereby improving the peeling force between aluminum foil and nylon, and thus improving the punching performance of aluminum-plastic film; it effectively avoids the phenomenon that the traditional aluminum-plastic film is prone to R corner damage during the high-depth punching process, so as to ensure that the punching pit is higher, rounder, wrinkle-free and fuller, so as to better meet the market demand of electronic digital products. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 It is a practical object for the traditional aluminum-plastic film to be damaged at the R corner during the deep punching process;

[0038] Figure 2 It is a structural schematic diagram of the shrinkage of the conventional aluminum-plastic film of the present invention during continuous batch production;

[0039] Figure 3 It is a flow chart of a method for continuous batch production of high-drawing aluminum-plastic films for soft-pack batteries according to an embodiment of the present invention;

[0040] Figure 4 It is a schematic diagram of the segmented ripening of the modified polyester polyurethane glue of Examples 1 to 3 of the present invention;

[0041] Figure 5 This is a schematic diagram of detecting a deep pit according to Embodiment 3 of the present invention;

[0042] Figure 6 A schematic diagram of the structure of a heat-resistant elastic rubber ring connected to a nylon-aluminum foil-polypropylene film composite roll in one direction according to an embodiment of the present invention;

[0043] Figure 7 This is a structural diagram of a nylon-aluminum foil-polypropylene film composite roll during transportation according to an embodiment of the present invention.

[0044] Figure numerals: 10, heat-resistant elastic rubber ring; 100, installation cavity; 110, elastic restraint cavity; 120, stress release margin cavity; 200, double-sided adhesive layer; 20, nylon-aluminum foil-polypropylene film composite roll. DETAILED DESCRIPTION

[0045] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.

[0046] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0048] See also Figure 3 In order to better understand the technical solution and beneficial effects of the present disclosure, the present disclosure is further described in detail below in conjunction with specific embodiments. A method for continuous batch production of high-drawing aluminum-plastic films for soft-pack batteries in one embodiment includes some or all of the following steps:

[0049] S101, placing the aluminum foil roll and the nylon roll on the dry laminating machine respectively to prepare for continuous production. Specifically, the aluminum foil roll is placed on the aluminum foil unwinding roller of the dry laminating machine; the nylon roll is placed on the nylon unwinding roller of the dry laminating machine, so that the aluminum foil roll and the nylon roll are placed on the dry laminating machine to prepare for continuous batch production.

[0050] S102, feeding the aluminum foil of the aluminum foil roll into the glue screen roller of the dry laminating machine. Specifically, the aluminum foil of the aluminum foil roll is unwound and fed into the glue screen roller through the conveying assembly of the dry laminating machine, so that the matte surface of the aluminum foil faces the glue screen roller, so that the glue screen roller can apply the modified polyester polyurethane glue screen roller on the matte surface of the aluminum foil.

[0051] S103, using the glue screen roller to apply the modified polyester polyurethane glue screen roller to the aluminum foil to obtain aluminum foil A, and applying the modified polyester polyurethane glue screen roller to the matte surface of the aluminum foil. The modified polyester polyurethane glue comprises the following components by weight: 40 to 55 parts of the polyester polyol main agent containing hydroxyl ends; 7 to 10 parts of the polyisocyanate curing agent; and 6 to 8 parts of the diluent.

[0052] It should be noted that the nylon layer of the aluminum-plastic film on the market currently mostly contains a lubricant. If polyether polyurethane glue is used, the ether bond (—O—) of the polyether polyurethane glue forms a hydrogen bond with the amino group (—NH2) in the lubricant, which affects the adhesion between the aluminum foil and the nylon, resulting in the aluminum-plastic film obtained by using the polyether polyurethane glue to be easily delaminated during the high-depth drawing process, resulting in R corner damage. As Chinese patent document CN112009067B discloses a dry composite process for composite aluminum-plastic film for power batteries, since the modified polyurethane glue of the composite aluminum-plastic film is prepared by dissolving polyester / ether polyol, carbon nanotubes, polyisocyanate and additives in ethyl acetate according to a certain mass ratio, there are some ether bonds that affect the adhesion between the aluminum foil roll and the nylon roll. In addition, the added carbon nanotubes will cause the hardness of the modified polyurethane glue to be higher, resulting in reduced flexibility of the modified polyurethane glue, which makes it easy to break the R corner during high-depth drawing, and it still cannot break through the drawing performance requirement of a deep pit greater than 11.0 mm.

[0053] Therefore, in the present disclosure, a polyester polyol main agent containing a hydroxyl end is used to directly replace the polyester / ether polyol, so that the polyester polyol main agent containing a hydroxyl end can react with a polyisocyanate curing agent to generate a polyester-type polymer with a branched three-dimensional cross-linked structure, effectively avoiding the addition of ether bonds, thereby solving the problem that the existence of ether bonds in the outer rubber layer of the traditional aluminum-plastic film affects the adhesion between the aluminum foil and the nylon, so as to improve the deep drawing performance of the aluminum-plastic film.

[0054] Furthermore, if only the polyester polyol main agent containing hydroxyl ends is used to replace the polyester / ether polyol, it only eliminates the problem of interference between the lubricant in the nylon and the ether bond in the modified polyester polyurethane glue, but cannot ensure that the modified polyester polyurethane glue finally generated has strong toughness and softness. Therefore, in the present disclosure, the formula between the polyester polyol main agent containing hydroxyl ends, the isocyanate curing agent and the diluent is further optimized. In this way, not only the addition of carbon nanotubes is avoided, but also the viscosity of the modified polyester polyurethane glue obtained by adding 40 to 55 parts of the polyester polyol main agent containing hydroxyl ends, 7 to 10 parts of polyisocyanate curing agent and 6 to 8 parts of diluent is ensured to be more suitable, so that 40 to 55 parts of the polyester polyol main agent containing hydroxyl ends can react with 7 to 10 parts of polyisocyanate curing agent to generate a polyester-type branched three-dimensional cross-linked structure polymer, and the generated polyester The branched three-dimensional cross-linked polymer can bond aluminum foil and nylon together very well, which not only improves the adhesion between aluminum foil and nylon, but also ensures that the modified polyester polyurethane adhesive layer formed after the final cross-linking and curing has a high cohesive force, so as to ensure that the modified polyester polyurethane adhesive layer is strong, tough and soft, thereby improving the peeling force between aluminum foil and nylon, and further improving the punching performance of aluminum-plastic film; effectively avoiding the phenomenon that the traditional aluminum-plastic film is prone to R corner damage during the high-depth punching process, so as to ensure that the punching pit is higher, rounder, wrinkle-free and fuller, so as to better meet the market demand of electronic digital products.

[0055] It can also be understood that, since 40 to 55 parts of a hydroxyl-terminated polyester polyol main agent, 7 to 10 parts of a polyisocyanate curing agent and 6 to 8 parts of a diluent are mixed to obtain a modified polyester polyurethane glue with a more suitable viscosity, on the one hand, it is ensured that the gluing screen roller can more comprehensively apply the modified polyester polyurethane glue screen roller to the aluminum foil, thereby ensuring the accuracy of the gluing; on the other hand, it is conducive to the separation of the gluing screen roller and the aluminum foil after the gluing is completed, thereby ensuring that the separation force between the aluminum foil roll and the nylon roll is small during the composite process, effectively avoiding the large separation force between the aluminum foil roll and the nylon roll during the composite process, which causes a large winding tension between the subsequent aluminum foil roll and the nylon roll, resulting in the phenomenon that the nylon layer of the aluminum-plastic film is easily retracted during the winding process, thereby reducing the defective rate of the aluminum-plastic film production.

[0056] That is to say, by controlling the viscosity of the modified polyester polyurethane glue to be more appropriate, while meeting the high drawing performance requirements, it also ensures the accuracy of the glue application amount, and is also beneficial to the separation of the aluminum foil roll and the nylon roll during compounding, so as to ensure the preparation of a high-drawing aluminum-plastic film for soft-pack lithium batteries with high drawing performance, high peeling force and not easy to shrink.

[0057] In addition, the optimized modified polyester polyurethane glue can ensure that the modified polyester polyurethane glue is strong, tough and soft, so that a thinner coating in production can meet the adhesion and high drawing performance between nylon and aluminum foil, and can better meet the development needs of aluminum-plastic films for thin and high-energy electronic digital products, such as being more widely used in the production of soft-pack lithium battery cells for 3C digital products and energy storage.

[0058] In one embodiment, the modified polyester polyurethane glue further includes 2.5 to 5.0 parts of an auxiliary agent. Specifically, the auxiliary agent is an A-8 additive. The added A-8 additive helps to increase the connection strength between the modified polyester polyurethane glue and the aluminum-plastic film, thereby improving the toughness and softness of the modified polyester polyurethane glue. The A-8 additive is provided by the Guangque glue manufacturer.

[0059] In one of the embodiments, the viscosity of the polyester polyol main agent containing hydroxyl ends is 200mP.s~1000mP.s; the viscosity of the polyisocyanate curing agent is 1000mP.s~3000mP.s; the viscosity of A-8 is 12500mP.s~14500mP.s, so as to ensure that the viscosity of the modified polyester polyurethane glue obtained by compounding is appropriate, better ensure that the separation force between the aluminum foil product and nylon is small during compounding, and facilitate the separation of the gluing wire roller and the aluminum foil roll after the gluing is completed.

[0060] In a preferred embodiment, the polyester polyol main agent containing hydroxyl ends is the polyester polyol main agent containing hydroxyl ends A-622; its main function is to provide adhesion and bonding performance, and the polyester polyol main agent containing hydroxyl ends A-622 is provided by the Guangque glue manufacturer. The polyisocyanate curing agent is the polyisocyanate curing agent HL-76, and its main function is to achieve cross-linking and curing with the polyester polyol main agent containing hydroxyl ends to ensure the formation of a three-dimensional network structure, thereby improving the toughness and softness of the modified polyester polyurethane glue. The polyisocyanate curing agent HL-76 is provided by the Guangque glue manufacturer.

[0061] S104, performing a first dry composite operation on the nylon of the nylon roll and the aluminum foil A to obtain a nylon-aluminum foil composite film, thereby achieving a nylon-aluminum foil composite operation. During the first dry composite operation, the winding tension of the aluminum foil roll is controlled to match the winding tension of the nylon roll.

[0062] It can be understood that in actual production, since nylon is a plastic material, the shrinkage rate of nylon is relatively large, while aluminum foil is a metal material, the shrinkage rate of aluminum foil is relatively small. When the nylon-aluminum foil composite film is under the same winding tension, the aluminum foil and nylon will be stretched to different degrees; especially for elastic materials such as nylon, when subjected to a large external winding tension, the nylon is easily stretched and deformed. When the external force disappears, the stretched nylon will shrink to cause the nylon-aluminum foil composite film to curl and cause undesirable problems. Therefore, in the present disclosure, by controlling the winding tension of the aluminum foil roll to match the winding tension of the nylon roll during the first dry composite operation, the winding tension between the aluminum foil roll and the nylon roll is closer, which effectively avoids the problem of nylon curling and shrinkage caused by the large difference in winding tension between the aluminum foil roll and the nylon roll in continuous batch production.

[0063] S105, performing a second dry lamination operation on the polypropylene film and the nylon-aluminum foil composite film to obtain a nylon-aluminum foil-polypropylene film composite roll, thereby achieving a lamination operation of the polypropylene film and the nylon-aluminum foil composite film, so that the polypropylene film (CPP film) can be well adhered to the bright surface of the aluminum foil.

[0064] It can be understood that since the polypropylene film has good firmness and flexibility, the additional polypropylene film is beneficial to improving the high-drawing performance of the high-drawing aluminum-plastic film of the soft-pack battery; and since the polypropylene film has heat-sealing and moisture-proof properties, it can ensure the heat-sealing performance and electrolyte corrosion resistance of the high-drawing aluminum-plastic film of the soft-pack battery, thereby providing good protection for the soft-pack battery.

[0065] S106, performing a drying and aging operation on the nylon-aluminum foil-polypropylene film composite roll.

[0066] It is understandable that during the drying and aging process of the nylon-aluminum foil-polypropylene film composite roll, the modified polyester polyurethane glue and the acid-modified polyolefin glue can undergo cross-linking and curing reactions to form a stable chemical structure. For details, please refer to Figure 4 The reaction rate shown in the figure better ensures the adhesion between the layers of the nylon-aluminum foil-polypropylene film composite roll, thereby improving the peeling force of the layers of the nylon-aluminum foil-polypropylene film composite roll, and effectively avoiding the delamination of the high-drawing aluminum-plastic film of the soft-pack battery during the drawing process, which leads to R corner damage.

[0067] S107, cutting the nylon-aluminum foil-polypropylene film composite roll after the drying and aging operation to obtain the high-drawing aluminum-plastic film for the soft-pack battery, so as to obtain the high-drawing aluminum-plastic film for the soft-pack battery required for packaging.

[0068] The method for continuous batch production of the high-drawing depth aluminum-plastic film of the above-mentioned soft-pack battery; the modified polyester polyurethane glue is coated on the aluminum foil by the glue mesh roller, so that the modified polyester polyurethane glue can be coated on the aluminum foil, and the added 40 to 55 parts of the polyester polyol main agent containing a hydroxyl end, 7 to 10 parts of the polyisocyanate curing agent and 6 to 8 parts of the diluent can be compounded to obtain a relatively suitable viscosity. On the premise of ensuring that the modified polyester polyurethane adhesive layer has strong toughness and softness, the peeling force between the aluminum foil and nylon is also improved, thereby improving the drawing depth performance of the aluminum-plastic film; effectively avoiding The invention solves the problem that the traditional aluminum-plastic film is prone to R corner damage during the high-depth drawing process, so as to better meet the packaging and sealing requirements of soft-pack batteries with larger diameters, so as to better adapt to the market demand of electronic digital products; it is also beneficial to the separation of the gluing wire roller and the aluminum foil after the gluing is completed, so as to ensure that the separation force of the aluminum foil A and the nylon is small when they are compounded, and effectively avoid the phenomenon that the nylon layer of the aluminum-plastic film is easy to shrink during the winding process due to the large separation force when the aluminum foil roll and the nylon roll are compounded. The nylon of the nylon roll is subjected to a first dry composite operation with the aluminum foil A to obtain a nylon-aluminum foil composite film; wherein, during the first dry composite operation, the winding tension of the aluminum foil roll is controlled to match the winding tension of the nylon roll; to ensure that the winding tension between the aluminum foil roll and the nylon roll is close, and the problem of nylon curling and shrinkage caused by the large difference in the winding tension between the aluminum foil roll and the nylon roll in continuous batch production is effectively avoided, thereby ensuring that the high-drawing aluminum-plastic film of the soft-pack battery finally prepared has high flatness and does not shrink, further reducing the production cost. The defective rate is reduced; then, the polypropylene film and the nylon-aluminum foil composite film are subjected to a second dry composite operation to obtain a nylon-aluminum foil-polypropylene film composite roll; the nylon-aluminum foil-polypropylene film composite roll is subjected to a drying and aging operation; the nylon-aluminum foil-polypropylene film composite roll after the drying and aging operation is cut to obtain the high-drawing aluminum-plastic film of the soft-pack battery, so as to prepare an aluminum-plastic film with high drawing depth and strong flexibility, thereby ensuring that a higher, rounded, wrinkle-free and full-bodied drawing pit is drawn, so as to better meet the packaging and sealing requirements of soft-pack batteries with larger diameters.

[0069] In one embodiment, the winding tension during the first dry compounding operation is controlled to be 25kg to 32kg, so as to ensure that the winding tension of the aluminum foil roll is compatible with the winding tension of the nylon roll, and to ensure that the shrinkage rate or stretching rate of the aluminum foil A and the nylon are as close as possible, thereby reducing the probability of the nylon roll curling. In a preferred embodiment, the winding tension during the first dry compounding operation is controlled to be 28kg.

[0070] In one of the embodiments, in the step of feeding the aluminum foil of the aluminum foil roll into the gluing screen roller of the dry laminating machine, the unwinding tension of the aluminum foil roll and the unwinding tension of the nylon roll are controlled to be smaller than the winding tension of the first dry laminating operation, on the one hand, ensuring that the unwinding speed of the aluminum foil roll and the unwinding speed of the nylon roll can better meet the requirements of continuous batch production, and on the other hand, reducing the stretching of the aluminum foil roll and the nylon roll, thereby reducing the probability of deformation of the aluminum foil roll and the nylon roll, so as to reduce the interference with the matching degree of the winding tension of the aluminum foil roll originally set and the winding tension of the nylon roll, reduce the probability of shrinkage of the nylon-aluminum foil composite film during the winding process, and better ensure the quality of continuous batch production.

[0071] In one embodiment, the unwinding tension of the aluminum foil roll is 10kg to 15kg. In a preferred embodiment, the unwinding tension of the aluminum foil roll is 14kg.

[0072] In one embodiment, the unwinding tension of the nylon roll is 1.0kg to 2.5kg. In a preferred embodiment, the unwinding tension of the nylon roll is 2.5kg.

[0073] In one of the embodiments, in the first dry composite operation, the composite tension of aluminum foil A and nylon is controlled to be 30kg-40kg. In a preferred embodiment, the composite tension of aluminum foil A and nylon is controlled to be 40kg, especially in combination with the unwinding tension of the aluminum foil roll and the unwinding tension of the nylon roll, to ensure that the winding tension of the aluminum foil roll in the nylon-aluminum foil composite film matches the winding tension of the nylon roll, thereby reducing the shrinkage problem of the nylon-aluminum foil composite film due to the large composite tension in the first dry composite operation.

[0074] In one of the embodiments, the drying temperature of the first dry compounding operation is 90° C. to 100° C. to achieve initial shaping and fixation of the modified polyester polyurethane glue.

[0075] In one embodiment, the diluent includes at least one of dimethyl carbonate, ethyl acetate, dimethyl carbonate and methyl acetate.

[0076] In one embodiment, the water content of the diluent does not exceed 300 ppm, and the alcohol content does not exceed 200 ppm, to ensure that the water content and alcohol content of the diluent are small, thereby reducing the viscosity of the modified polyester polyurethane glue and the cross-linking reaction due to the added diluent containing more water or alcohol.

[0077] In one embodiment, the polypropylene film and the nylon-aluminum foil composite film are subjected to a second dry composite operation using acid-modified polyolefin glue.

[0078] It should be noted that although the high-drawing performance of the aluminum-plastic film can be improved by optimizing the modified polyester polyurethane glue, during the drawing process, the five layers of polypropylene film layer, inner rubber layer, aluminum foil layer, outer rubber layer and nylon layer are stretched together. When the drawing depth is greater than 7.5 mm, since the punching die head is in direct contact with the polypropylene film layer, if the traditional polyolefin glue is still used as the inner rubber layer, the traditional polyolefin glue is easily delaminated with the aluminum foil layer under the action of a larger drawing force, especially in the high-drawing depth greater than 11.00 mm, the delamination of the traditional polyolefin glue and the aluminum foil layer is more obvious.

[0079] Therefore, in the present disclosure, by acid-modifying the polyolefin glue, the acid-modified polyolefin glue is introduced with an acid functional group, so that the acid functional group can coordinate with the aluminum metal ions of the aluminum foil, thereby improving the adhesion between the acid-modified polyolefin glue and the aluminum foil, thereby improving the adhesion between the polypropylene film layer and the aluminum foil layer; effectively avoiding the acid-modified polyolefin glue from being easily delaminated with the aluminum foil layer under a large punching force, so as to ensure that a punching pit greater than 11.00 mm, round, wrinkle-free and full is punched out. For details, please refer to Figure 5 .

[0080] In one embodiment, the acid-modified polyolefin glue includes the following mass components: 90 parts to 100 parts of acid-modified polyolefin resin: 1 part to 5 parts of aliphatic polyisocyanate curing agent; 10 parts to 15 parts of methane; 3 parts to 5 parts of butanone, so as to ensure that the acid-modified polyolefin glue with high flexibility and high adhesion is obtained, thereby ensuring that the acid-modified polyolefin glue can buffer against higher punching forces to ensure that a punching pit greater than 11.00 mm, round, wrinkle-free and full is punched out.

[0081] It is worth mentioning that since most polypropylene films contain lubricants, the present invention uses acid-modified polyolefin glue to avoid the addition of ether bonds, thereby ensuring the adhesion between the polypropylene film and the nylon-aluminum foil composite film and improving the peeling force between the polypropylene film and the nylon-aluminum foil composite film.

[0082] In one embodiment, the acid-modified polyolefin resin is Toyotac PMA-KH solution provided by DYF manufacturer.

[0083] In one embodiment, the aliphatic polyisocyanate curing agent is Desmodur N3300, which is provided by Covestro.

[0084] In one embodiment, the viscosity of Toyotac PMA-KH is 1000mPa.s~2100mPa.s; the viscosity of Desmodur N3300 is less than 100mPa.s, thereby ensuring that the viscosity of the obtained acid-modified polyolefin glue is appropriate, ensuring that the gluing screen roller can more accurately apply the acid-modified polyolefin glue screen roller to the aluminum foil, thereby ensuring the accuracy of gluing; on the other hand, it is beneficial to the separation of the gluing screen roller and the nylon-aluminum foil composite film after the gluing is completed, thereby ensuring that the separation force of the nylon-aluminum foil composite film and the polypropylene film is small during the composite, effectively avoiding the large separation force of the nylon-aluminum foil composite film and the polypropylene film during the composite, resulting in a large winding tension of the subsequent nylon-aluminum foil-polypropylene film composite roll to cause the nylon-aluminum foil-polypropylene film composite roll to shrink, and further reducing the production defect rate.

[0085] It should be noted that in the process of deep drawing, since the elongation of the polypropylene film (1000-900) is greater than the elongation of the nylon layer (up to 200), the deep drawing of the aluminum-plastic film can be achieved. In addition, the modified polyester polyurethane glue layer used in the outer rubber layer gives the outer rubber layer a certain buffering and antagonistic effect, which can achieve a good protective effect on the outer nylon layer. However, in the process of high deep drawing, due to the direct contact between the deep drawing die head and the polypropylene film layer, the polypropylene film layer is subjected to the greatest force in the process of high deep drawing. In addition, the amount of the outer layer glue of the traditional aluminum-plastic film and the amount of the inner layer are generally set to 2:1, resulting in the thickness of the inner layer in the aluminum-plastic film being relatively thin, and the thinner inner layer cannot provide a good buffering and antagonistic effect for the polypropylene film, resulting in the polypropylene film being subjected to greater force under the action of high deep drawing force, which easily causes the polypropylene film layer to be delaminated, wrinkled or damaged, and it is impossible to ensure that the deep drawing pit is round and full. Therefore, in the present disclosure, by increasing the usage of the inner rubber layer, the inner rubber layer can play a good buffering and counteracting role for the polypropylene film layer during the high-depth punching process, effectively avoiding the polypropylene film from being subjected to greater stress under the action of high-depth punching force and being prone to delamination, wrinkling or damage.

[0086] It can be understood that if the amount of the inner rubber layer added is too much, the actual punching force reaching the nylon layer will be reduced, so that it is impossible to punch out a higher punching pit, that is, it affects the high punching performance of the aluminum-plastic film. If the amount of the inner rubber layer added is too little, it is impossible to ensure that the inner rubber layer can play a good buffering and antagonistic role on the polypropylene film layer, and there is still a phenomenon that the polypropylene film layer is delaminated, wrinkled or damaged. Therefore, in the present disclosure, by setting the glue amount of the modified polyester polyurethane glue and the glue amount of the acid-modified polyolefin glue to (1.0-1.5): (2.0-2.5), it is ensured that the thickness of the modified polyester polyurethane glue layer (outer rubber layer) formed in the end is less than the thickness of the acid-modified polyolefin glue layer (inner rubber layer), that is, the thickness of the inner rubber layer is increased, so that the inner rubber layer can achieve a good buffering and antagonism to the force of the polypropylene film layer, and it is also ensured that the punching force reaching the nylon layer is more appropriate, so as to ensure that a higher, round, wrinkle-free and full punching pit is punched out.

[0087] It should also be noted that the present invention can better ensure that the thickness variation of the high-drawing aluminum-plastic film of the soft-pack battery is small by adjusting the glue amount of the modified polyester polyurethane glue and the glue amount of the acid-modified polyolefin glue to (1.0~1.5): (2.0~2.5), so as to better meet the application of thin and high-energy electronic digital products.

[0088] In a preferred embodiment, the amount of modified polyester polyurethane glue applied is 6g / m 2 ~9g / m 2 ; The amount of acid-modified polyolefin glue applied is 12g / m 2 ~15g / m 2 ; To ensure that the thickness of the final acid-modified polyolefin glue layer is greater than that of the modified polyester polyurethane glue layer, thereby ensuring that the acid-modified polyolefin glue layer can well buffer and resist the force of the polypropylene film layer, so as to ensure that a higher, round, wrinkle-free and fuller punching pit can be punched out in the end, so as to better meet the development needs of thinner and higher punching performance aluminum-plastic films, such as in the application of soft-pack lithium batteries in 3C digital products, energy storage, etc.

[0089] It can be understood that since many concave dots are formed on the surface of the glue screen roller, these concave dots will hide part of the modified polyester polyurethane glue. Therefore, in order to ensure the accuracy of the modified polyester polyurethane glue screen roller coating, in one embodiment, in the step of coating the modified polyester polyurethane glue screen roller on the aluminum foil through the glue screen roller, the following relationship is set between the glue amount of the modified polyester polyurethane glue and the depth of the concave dots, the concentration of the modified polyester polyurethane glue and the density of the modified polyester polyurethane glue:

[0090] W1=(1 / 6~1 / 4)*μ1*N1*D1

[0091] W1—the amount of modified polyester polyurethane glue applied, g / ㎡;

[0092] μ1--depression dot depth;

[0093] N1—concentration of modified polyester polyurethane glue, %;

[0094] D1—density of modified polyester polyurethane glue;

[0095] This ensures the accuracy of the modified polyester polyurethane glue mesh roller coating.

[0096] Similarly, in one of the embodiments, the accuracy of the acid-modified polyolefin glue screen roller coating is that in the step of coating the acid-modified polyolefin glue screen roller on the aluminum foil through the glue screen roller, the following relationship is set between the glue amount of the acid-modified polyolefin glue and the depth of the recessed dots, the concentration of the acid-modified polyolefin glue and the density of the acid-modified polyolefin glue:

[0097] W2=(1 / 3~13 / 25)*μ2*N2*D2

[0098] W2—acid-modified polyolefin glue glue amount, g / ㎡;

[0099] μ2--depression dot depth;

[0100] N2—concentration of acid-modified polyolefin glue, %;

[0101] D2—density of acid-modified polyolefin glue;

[0102] This ensures the accuracy of the acid-modified polyolefin glue web roller coating.

[0103] It should be noted that, as the amount of the acid-modified polyolefin glue applied increases, in order to ensure that the acid-modified polyolefin glue can be well coated on the bright surface of the aluminum foil of the nylon-aluminum foil composite film by the mesh roller. Therefore, in the present disclosure, 90 to 100 parts of acid-modified polyolefin resin, 1 to 5 parts of aliphatic polyisocyanate curing agent, 10 to 15 parts of methane, and 3 to 5 parts of butanone are compounded and used to ensure that the acid-modified polyolefin glue has a more suitable viscosity, that is, the acid-modified polyolefin glue has better fluidity. In this way, on the one hand, it is ensured that the bright surface of the aluminum foil of the nylon-aluminum foil composite film can be coated with a mesh roller to obtain a relatively uniform thickness of the acid-modified polyolefin glue layer, and on the other hand, it is ensured that after the mesh roller is coated, the nylon-aluminum foil composite film and the glue mesh roller are better separated, effectively avoiding the problem of deformation of the nylon-aluminum foil composite film, especially in conjunction with the formula of the glue amount of the acid-modified polyolefin glue, not only the accuracy of the acid-modified polyolefin glue mesh roller coating is better ensured, but also the consistency and uniformity of the coating of the acid-modified polyolefin glue produced in continuous batches are ensured. Further, in a preferred embodiment, the fluidity of the acid-modified polyolefin glue is 4W.

[0104] In one of the embodiments, the step of performing a second dry composite operation on the polypropylene film and the nylon-aluminum foil composite film includes the following specific steps: turning over the nylon-aluminum foil composite film so that the bright side of the aluminum foil of the nylon-aluminum foil composite film faces the gluing screen roller of the second dry composite operation, so that the gluing screen roller can apply the acid-modified polyolefin glue to the bright side of the aluminum foil of the nylon-aluminum foil composite film; then, feeding the nylon-aluminum foil composite film coated with the acid-modified polyolefin glue into the second dry composite and performing a composite operation with the polypropylene film to obtain a nylon-aluminum foil-polypropylene film composite roll.

[0105] It is worth mentioning that, since the amount of acid-modified polyolefin glue applied is larger than that of the traditional inner glue layer, the flowability of the thick acid-modified polyolefin glue slows down. In order to solve the problem of the slow flowability of the acid-modified polyolefin glue, the speed of continuous batch production can be reduced, but this will lead to a decrease in productivity. In order to find a method that does not require reducing the speed of continuous batch production to ensure that the thicker acid-modified polyolefin glue has a faster flowability, therefore, in the present disclosure, by adjusting the tension of the nylon-aluminum foil composite film in the second dry composite operation and the mesh roller coating force of the glue screen roller, the glue screen roller is in arc contact with the nylon-aluminum foil composite film during mesh roller coating. When the glue screen roller is in mesh roller coating, the nylon-aluminum foil composite film undergoes a slight arc deformation under the action of the glue screen roller to ensure that the glue screen roller is subjected to the force of the nylon-aluminum foil composite film. In this way, under the premise of minimizing the deformation of the nylon-aluminum foil composite film, it is also ensured that the gluing mesh roller can micro-extrude the bright surface of the aluminum foil of the nylon-aluminum foil composite film, so that the acid-modified polyolefin glue coated on the bright surface of the aluminum foil of the nylon-aluminum foil composite film can be better cast around when being squeezed by the mesh roller, and the thicker acid-modified polyolefin glue can be guaranteed to have faster castability without reducing the speed of continuous batch production, and ensure that the bright surface of the aluminum foil of the nylon-aluminum foil composite film is obtained. The acid-modified polyolefin glue with high flatness and good uniformity is obtained.

[0106] In one of the embodiments, by adjusting the tension of the nylon-aluminum foil composite film in the second dry composite operation and by controlling the tension of the nylon-aluminum foil composite film not to be too tight, the nylon-aluminum foil composite film is slightly straightened upward along the tangent direction of the glue screen roller to ensure that the nylon-aluminum foil composite film has a slight relaxation. In this way, when the glue screen roller is performing screen roller coating, the glue screen roller and the nylon-aluminum foil composite film are in slight arc contact, so that the glue screen roller can perform screen roller coating on the bright surface of the aluminum foil of the nylon-aluminum foil composite film while ensuring that the thicker acid-modified polyolefin glue can flow faster to the surroundings, thereby coating a uniform acid-modified polyolefin glue layer.

[0107] In one embodiment, due to the different materials of nylon and polypropylene film, the tensile strength of polypropylene film is lower than that of nylon, that is, polypropylene film is more prone to deformation. Therefore, in order to avoid deformation of polypropylene film during continuous batch production, first, the unwinding tension of polypropylene film is controlled to be 1kg to 2kg; to avoid deformation of polypropylene film before being fed into the glue screen roller of the second dry lamination operation. In a preferred embodiment, the unwinding tension of polypropylene film is 2kg.

[0108] Next, the composite tension of the polypropylene film and the nylon-aluminum foil composite film is controlled to be 35kg to 40kg. It can be understood that by controlling the composite tension of the polypropylene film and the nylon-aluminum foil composite film to be 35kg to 40kg, the composite tension of the five layers of polypropylene film, acid-modified polyolefin glue, aluminum foil, modified polyester polyurethane glue and nylon is ensured to be close, so as to avoid the problem of deformation of the polypropylene film when it is fed into the glue screen roller of the second dry composite operation, and better ensure the high flatness and no shrinkage of the high-drawing aluminum-plastic film of the soft-pack battery finally prepared, and well ensure the product quality of the high-drawing aluminum-plastic film of the soft-pack battery. In a preferred embodiment, the composite tension of the polypropylene film and the nylon-aluminum foil composite film is 40kg.

[0109] Finally, the tension of the second dry composite winding is controlled to be 20kg to 28kg; in particular, the tension of the composite winding of the first dry composite operation, the unwinding tension of the nylon roll and the unwinding tension of the aluminum foil roll are coordinated to ensure that the tension matching degree of the high-drawing aluminum-plastic film of the soft-pack battery is high in the entire process of continuous batch production, and better ensure that the high-drawing aluminum-plastic film of the soft-pack battery finally prepared is high in flatness and does not shrink. In a preferred embodiment, the tension of the second dry composite winding is controlled to be 28kg.

[0110] In one embodiment, the rotation speed of the gluing wire roller in the first dry lamination operation is 140r / min~154r / min, and the lamination roller speed is 100r / min~110r / min, so as to ensure that the lamination tension between the nylon roll and the aluminum foil A is more appropriate, so as to obtain a smooth and bubble-free nylon-aluminum foil composite film.

[0111] In one of the embodiments, the rotation speed of the gluing wire roller in the second dry lamination operation is 130r / min~144r / min, and the speed of the laminating roller is 100r / min~108r / min, so as to ensure that the laminating tension between the polypropylene film and the nylon-aluminum foil composite film is more appropriate, so as to obtain a smooth and bubble-free nylon-aluminum foil-polypropylene film composite roll.

[0112] In one embodiment, during the first dry lamination operation, a first entry inclined wrap angle is formed between the nylon roll and the aluminum foil A when entering the lamination roller. In this way, the nylon roll and the aluminum foil A are ensured to enter the lamination roller along the tangent direction of the two sides of the lamination roller, respectively, so as to ensure that the nylon of the nylon roll can be well attached to the modified polyester polyurethane glue of the aluminum foil A, and effectively avoid the problem of too much air being sandwiched into the nylon of the nylon roll when it is attached to the aluminum foil roll, thereby causing a large number of bubbles.

[0113] In one of the embodiments, the first entry tilt wrap angle is 1° to 15°.

[0114] Similarly, in one of the embodiments, in order to prevent the polypropylene film and the nylon-aluminum foil composite film from easily generating bubbles during the composite process, during the second dry composite operation, a second entry inclined wrap angle is formed between the nylon-aluminum foil composite film and the polypropylene film when entering the composite roller. In this way, the nylon-aluminum foil composite film and the polypropylene film are ensured to enter the composite roller along the tangent direction on both sides of the composite roller, respectively, so as to ensure that the polypropylene film can be well attached to the acid-modified polyolefin glue of the nylon-aluminum foil composite film, and effectively avoid the problem of excessive air being easily sandwiched into the polypropylene film when it is attached to the bright surface of the aluminum foil of the nylon-aluminum foil composite film, thereby causing bubbles.

[0115] In one of the embodiments, the second entry tilt wrap angle is 10° to 25°.

[0116] In one embodiment, after the step of placing the aluminum foil roll and the nylon roll on the dry laminating machine respectively, and before the step of feeding the aluminum foil of the aluminum foil roll into the glue screen roller of the dry laminating machine, the following specific steps are also included: first, the aluminum foil is subjected to surface pretreatment to effectively remove grease or impurities on the surface of the aluminum foil to ensure the adhesion between the aluminum foil and the modified polyester polyurethane glue and the acid-modified polyolefin glue to obtain aluminum foil B; then, the two sides of the aluminum foil B are subjected to surface treatment with a surface modifier to form surface protection films on the two sides of the aluminum foil B. Specifically, one side of the aluminum foil B is subjected to surface treatment with a passivation liquid to obtain a matte surface of the aluminum foil, thereby improving the adhesion between the matte surface of the aluminum foil and the modified polyester polyurethane glue, and further improving the peeling force between the aluminum foil layer and the nylon layer. Specifically, the thickness of the passivation liquid is less than 1um. Next, the other side of the aluminum foil B is treated with a surface treatment agent to form a bright surface on the other side of the aluminum foil B, so as to ensure that the acid-modified polyolefin glue can be well cast and laid flat on the bright surface of the aluminum foil, so as to ensure that a high-flatness and uniform acid-modified polyolefin glue layer is obtained on the bright surface of the aluminum foil, and reduce the entry of bubbles, thereby ensuring the quality of continuous batch production of high-drawing aluminum-plastic films for soft-pack batteries. Specifically, the thickness of the surface treatment agent is less than 1um.

[0117] In this embodiment, the thickness of the aluminum foil is 30 um to 45 um; preferably, the thickness of the aluminum foil is 40 um.

[0118] In one of the embodiments, the drying and aging operation conditions are 60°C to 90°C for 4 to 8 days to ensure that the modified polyester polyurethane glue and the acid-modified polyolefin glue can fully and comprehensively undergo cross-linking and curing reactions, thereby ensuring that the adhesion of each layer of the nylon-aluminum foil-polypropylene film composite roll is high and the flexibility is strong, so as to avoid the high-drawing aluminum-plastic film of the soft-pack battery from being easily delaminated during the drawing process and causing R corner damage, thereby ensuring that the high-drawing aluminum-plastic film of the soft-pack battery can punch out a higher, rounded, wrinkle-free and fuller drawing pit.

[0119] It can be understood that due to the increased usage of the inner rubber layer and the inherent characteristics of the winding type nylon-aluminum foil-polypropylene film composite roll, the drying and aging difficulty of the nylon-aluminum foil-polypropylene film composite roll becomes higher. Therefore, in one embodiment, by controlling the winding force to be smaller at the beginning of the second composite operation, the winding force in the middle is larger, and the winding tension is the smallest at the end, so as to ensure that the gap between each circle of the nylon-aluminum foil-polypropylene film composite roll after winding is relatively large, so as to reduce the compactness of each circle of the nylon-aluminum foil-polypropylene film composite roll, which is conducive to the subsequent drying and aging of the nylon-aluminum foil-polypropylene film composite roll. The external temperature can better enter the interior of the nylon-aluminum foil-polypropylene film composite roll, ensuring that the overall aging consistency of the nylon-aluminum foil-polypropylene film composite roll after drying and aging is better, and effectively ensuring the cross-linking effect of the high-drawing aluminum-plastic film of the soft-pack battery, so as to prepare a nylon-aluminum foil-polypropylene film composite roll with good overall aging consistency, strong flexibility, and good adhesion.

[0120] In one of the embodiments, before the step of drying and aging the nylon-aluminum foil-polypropylene film composite roll and after the step of performing a second dry composite operation on the polypropylene film and the nylon-aluminum foil composite film, the following step is also included: using a heat-resistant elastic rubber ring to fix the rolled nylon-aluminum foil-polypropylene film composite roll, so as to effectively avoid the problem of the nylon-aluminum foil-polypropylene film composite roll being scattered during the transportation process and affecting the transportation.

[0121] It should be noted that, compared with the traditional method of simply using fixing glue or binding tape, the fixing glue alone is easy to be torn apart and scattered, while the binding tape alone is inelastic, which causes the expanded nylon-aluminum foil-polypropylene film composite roll 20 to be easily tightened, thus affecting the overall maturation consistency of the nylon-aluminum foil-polypropylene film composite roll 20. Therefore, please refer to Figure 6 In one embodiment, a heat-resistant elastic rubber ring 10 is provided with an installation cavity 100, and a double-sided adhesive layer 200 is formed on an inner wall of one side of the installation cavity 100, and a release film is formed on the double-sided adhesive layer 200. When in use, the release film of the double-sided adhesive layer 200 is peeled off so that the double-sided adhesive layer 200 can be adhered to the other side of the installation cavity 100 under the action of an external force, so as to separate the installation cavity 100 into an elastic restraint cavity 110 and a stress release margin cavity 120, and the elastic restraint cavity 110 is used to set the nylon-aluminum foil-polypropylene film composite roll 20.

[0122] It can be understood that when in use, the operator sets the heat-resistant elastic rubber ring 10 on the outer peripheral wall of the nylon-aluminum foil-polypropylene film composite roll 20, then peels off the release film on the double-sided adhesive layer 200, and then presses the heat-resistant elastic rubber ring 10 provided with the double-sided adhesive layer 200 to make the double-sided adhesive layer 200 stick to the other side of the installation cavity 100, so as to divide the installation cavity 100 of the heat-resistant elastic rubber ring 10 into an elastic restraining cavity 110 and a stress release margin cavity 120, and the nylon-aluminum foil-polypropylene film composite roll 20 is located in the elastic restraining cavity 110, thereby realizing the limited fixation of the nylon-aluminum foil-polypropylene film composite roll 20, better ensuring the gap between each circle of the nylon-aluminum foil-polypropylene film composite roll 20 after winding, and also avoiding the nylon-aluminum foil-polypropylene film composite roll 20 being easily deformed during the transportation process. and when the nylon-aluminum foil-polypropylene film composite roll 20 is being dried and matured, the nylon-aluminum foil-polypropylene film composite roll 20 will slowly expand due to the heat, so that the diameter of the nylon-aluminum foil-polypropylene film composite roll 20 will slowly increase, so that the nylon-aluminum foil-polypropylene film composite roll 20 with an increased diameter will slowly break free from the fixation of the double-sided adhesive layer 200, so that the elastic restraint cavity 110 and the stress release margin cavity 120 can be restored to be connected, which is beneficial to the release of the stress of the nylon-aluminum foil-polypropylene film composite roll 20 during drying and maturation. In this way, the fixation of the nylon-aluminum foil-polypropylene film composite roll 20 during drying and maturation is achieved, and the problem of the heat-resistant elastic rubber ring 10 being too tightly mounted on the nylon-aluminum foil-polypropylene film composite roll 20, which affects the release of the stress of the nylon-aluminum foil-polypropylene film composite roll 20 during drying and maturation, is avoided.

[0123] It can be understood that in order to achieve better fixation of the transported nylon-aluminum foil-polypropylene film composite roll 20, and at the same time ensure that the nylon-aluminum foil-polypropylene film composite roll 20 can break free from the fixation of the double-sided adhesive layer 200 after drying and aging, in the present disclosure, the ratio of the area of ​​the double-sided adhesive layer 200 to the area of ​​the inner wall of the installation cavity 100 is 1:30, so as to ensure that the double-sided adhesive layer 200 is more appropriately distributed on the inner wall of the installation cavity 100. In this way, while satisfying the better fixation of the transported nylon-aluminum foil-polypropylene film composite roll 20, it can also ensure that the nylon-aluminum foil-polypropylene film composite roll 20 can break free from the fixation of the double-sided adhesive layer 200 after drying and aging.

[0124] It can be understood that in order to achieve better fixation of the nylon-aluminum foil-polypropylene film composite roll 20 during transportation, the nylon-aluminum foil-polypropylene film composite roll 20 is transported horizontally, and the stress release margin cavity 120 is set upward, see Figure 7In this way, it is ensured that the double-sided adhesive layer 200 of the heat-resistant elastic rubber ring 10 of the nylon-aluminum foil-polypropylene film composite roll 20 is not easy to fall off during the transportation process, thereby better ensuring that the nylon-aluminum foil-polypropylene film composite roll 20 is not scattered during the transportation process.

[0125] In one of the embodiments, a micro-gap is formed in the elastic restraint cavity of the nylon-aluminum foil-polypropylene film composite roll, which effectively prevents the heat-resistant elastic rubber ring from being too tight on the nylon-aluminum foil-polypropylene film composite roll, thereby preventing the nylon-aluminum foil-polypropylene film composite roll from having marks on it, thereby affecting the appearance quality of the high-drawing aluminum-plastic film for soft-pack lithium batteries. In addition, due to the existence of the micro-gap, the nylon-aluminum foil-polypropylene film composite roll will become slightly loosened between the turns of the nylon-aluminum foil-polypropylene film composite roll during transportation, which is beneficial to increase the gap between the turns of the nylon-aluminum foil-polypropylene film composite roll, thereby facilitating the release of stress of the nylon-aluminum foil-polypropylene film composite roll during drying and aging, and at the same time improving the overall aging consistency of the nylon-aluminum foil-polypropylene film composite roll, and realizing the fixation of the limit of the nylon-aluminum foil-polypropylene film composite roll.

[0126] In one of the embodiments, the size of the installation cavity is equal to the size of the nylon-aluminum foil-polypropylene film composite roll after drying and aging, and the elastic binding cavity is adapted to the size of the nylon-aluminum foil-polypropylene film composite roll that has not been dried and aged. In this way, under the premise of achieving the fixation of the nylon-aluminum foil-polypropylene film composite roll during drying and aging, it is also avoided that the heat-resistant elastic rubber ring is too tightly set on the nylon-aluminum foil-polypropylene film composite roll, thereby affecting the release of the stress of the nylon-aluminum foil-polypropylene film composite roll during drying and aging, and the overall aging consistency of the nylon-aluminum foil-polypropylene film composite roll is improved; it is also ensured that the fully aged nylon-aluminum foil-polypropylene film composite roll can be just attached to the heat-resistant elastic rubber ring to achieve the fixation of the aged nylon-aluminum foil-polypropylene film composite roll, and the marks of the heat-resistant elastic rubber ring on the nylon-aluminum foil-polypropylene film composite roll are reduced, thereby better ensuring the product quality of the nylon-aluminum foil-polypropylene film composite aluminum-plastic film.

[0127] In a preferred embodiment, the size of the installation cavity is equal to the size of the nylon-aluminum foil-polypropylene film composite roll after drying and aging, and the elastic restraint cavity is equal to the sum of the size of the undried and aging nylon-aluminum foil-polypropylene film composite roll and the microgap, so as to ensure that the dried and aged nylon-aluminum foil-polypropylene film composite roll can be just attached to the heat-resistant elastic rubber ring. On the premise of solving the problem of stress release of the nylon-aluminum foil-polypropylene film composite roll, the heat-resistant elastic rubber ring can also prevent the marks on the nylon-aluminum foil-polypropylene film composite roll, and better ensure the consistency of the overall aging of the nylon-aluminum foil-polypropylene film composite roll.

[0128] In one embodiment, the heat-resistant elastic rubber ring can be a silicone rubber ring. Of course, those skilled in the art can also use other replaceable rubber materials.

[0129] The present disclosure also provides a high-drawing aluminum-plastic film for soft-pack batteries, which is prepared by the method for continuous batch production of high-drawing aluminum-plastic films for soft-pack batteries described in any of the above embodiments. It can be understood that the method for continuous batch production of high-drawing aluminum-plastic films for soft-pack batteries disclosed in the present disclosure can prepare a high-drawing aluminum-plastic film for soft-pack batteries that is thin and high in energy and has high drawing performance, is round, wrinkle-free, and has high fullness.

[0130] In one embodiment, the high-draw aluminum-plastic film of the soft-pack battery includes, from the outside to the inside, a nylon layer, a modified polyester polyurethane glue layer, an aluminum foil layer, an acid-modified polyolefin glue layer and a polypropylene film layer stacked in sequence, wherein the modified polyester polyurethane glue layer is prepared by compounding 40 to 55 parts of the polyester polyol main agent containing a hydroxyl end; 7 to 10 parts of the polyisocyanate curing agent, and 6 to 8 parts of the diluent; the acid-modified polyolefin glue layer is prepared by compounding 90 to 100 parts of acid-modified polyolefin resin: 1 to 5 parts of aliphatic polyisocyanate curing agent; 10 to 15 parts of methane; and 3 to 5 parts of The butanone is compounded, and the thickness ratio of the modified polyester polyurethane glue layer to the acid-modified polyolefin glue layer is (1.0-1.5): (2.0-2.5), so that the thickness of the acid-modified polyolefin glue layer is greater than that of the modified polyester polyurethane glue layer, so that the acid-modified polyolefin glue layer can buffer and resist the force of the polypropylene film layer, and the inner glue layer can achieve better buffering and resisting against the force of the polypropylene film layer, while also ensuring that the punching force reaching the nylon layer is more appropriate, ensuring that a punching pit greater than 11.00mm, round, wrinkle-free and high in fullness is punched out, so as to better meet the application of thin and high-energy electronic digital products.

[0131] Compared with the prior art, the present invention has at least the following advantages:

[0132] 1) The addition of 40 to 55 parts of a polyester polyol main agent containing a hydroxyl end, 7 to 10 parts of a polyisocyanate curing agent and 6 to 8 parts of a diluent can be mixed to obtain a modified polyester polyurethane glue with a suitable viscosity. On the premise of ensuring that the modified polyester polyurethane adhesive layer has strong toughness and softness, the peeling force between the aluminum foil and the nylon is improved, thereby improving the deep drawing performance of the aluminum-plastic film; effectively avoiding the phenomenon that the traditional aluminum-plastic film is prone to R corner damage during the high-depth drawing process, so as to better meet the packaging and sealing requirements of larger diameter soft-pack batteries, so as to better It can adapt to the market demand of electronic digital products; it can also ensure that the gluing wire roller can more comprehensively apply the modified polyester polyurethane glue mesh roller to the aluminum foil, thereby ensuring the accuracy of gluing; it is also conducive to the separation of the gluing wire roller and the aluminum foil after the gluing is completed, thereby ensuring that the separation force of the aluminum foil A and nylon is small when they are compounded, and effectively avoiding the phenomenon that the aluminum foil roll and the nylon roll are easy to shrink during the winding process due to the large separation force when the aluminum foil roll and the nylon roll are compounded. The defective rate of aluminum-plastic film production is reduced.

[0133] 2) By controlling the winding tension of the aluminum foil roll to match the winding tension of the nylon roll during the first dry composite operation, the winding tension between the aluminum foil roll and the nylon roll is ensured to be close, thereby effectively avoiding the problem of nylon curling and shrinkage caused by the large difference in winding tension between the aluminum foil roll and the nylon roll in continuous batch production, thereby ensuring that the high-drawing aluminum-plastic film of the soft-pack battery finally prepared has high flatness and does not shrink, further reducing the defective rate of aluminum-plastic film production.

[0134] 3) Since the polyester polyol main agent containing hydroxyl ends can react with the polyisocyanate curing agent to generate a polyester-type branched three-dimensional cross-linked polymer, and the generated polyester-type branched three-dimensional cross-linked polymer can well bond the aluminum foil and nylon together, the addition of ether bonds is effectively avoided, thereby solving the problem that the ether bonds in the outer rubber layer of the traditional aluminum-plastic film affect the adhesion between the aluminum foil and nylon, and avoiding the hardness of the traditional modified polyurethane glue caused by the addition of carbon nanotubes to increase and affect the deep punching performance of the aluminum-plastic film. It not only improves the adhesion between aluminum foil and nylon, but also ensures that the modified polyester polyurethane adhesive layer formed after the final cross-linking and curing has a high cohesive force, so as to ensure that the modified polyester polyurethane adhesive layer is strong, tough and soft, thereby improving the peeling force between aluminum foil and nylon, and thus improving the punching performance of aluminum-plastic film; it effectively avoids the phenomenon that the traditional aluminum-plastic film is prone to R corner damage during the high-depth punching process, so as to ensure that the punching pit is higher, rounder, wrinkle-free and fuller, so as to better meet the market demand of electronic digital products.

[0135] Some specific examples are given below, and if % is mentioned, it means percentage by weight. It should be noted that the following examples do not exhaust all possible situations, and the materials used in the following examples can be obtained from commercial sources unless otherwise specified.

[0136] It should be noted that the main agent of polyester polyol containing hydroxyl end is A-622 (viscosity is 1000mPa.s), provided by Guangque manufacturer; the polyisocyanate curing agent is HL-76 (viscosity is 3000mPa.s), provided by Guangque manufacturer; the auxiliary agent is A-8 (12500mPa.s), provided by Guangque manufacturer; the diluent is methyl acetate, provided by Hongchuan manufacturer; the acid-modified polyolefin resin is PMA-KH (viscosity is 1510mPa.s), provided by DYF manufacturer; the aliphatic polyisocyanate curing agent is DesmodurN3300 (viscosity is 80mPa.s), provided by Covestro manufacturer; methane (CH) and butanone (MEK) are both provided by Hongchuan manufacturer;

[0137] Table 1 Recipe used

[0138]

[0139]

[0140] Method for continuous batch production of high-drawing aluminum-plastic films for soft-pack batteries of Examples 1 to 3:

[0141] Step 1: Place the aluminum foil roll (aluminum foil thickness is 30um) on the aluminum foil unwinding roller of the dry laminating machine; place the nylon roll on the nylon unwinding roller of the dry laminating machine; prepare for continuous production, and control the unwinding tension of the aluminum foil roll to 14kg; the unwinding tension of the nylon roll to 2.5kg;

[0142] Step 2: performing a surface pretreatment operation on the aluminum foil to obtain aluminum foil B; then, using a passivation solution (thickness less than 1 um) to perform surface treatment on one side of the aluminum foil B to form a matte surface on one side of the aluminum foil B; then using a surface treatment agent to perform surface treatment on the other side of the aluminum foil B to form a bright surface on the other side of the aluminum foil B; and obtaining a treated aluminum foil roll;

[0143] Step 3: Feed the aluminum foil roll processed in step 2 to the gluing screen roller through the conveying component of the dry laminating machine, so that the matte surface of the aluminum foil faces the gluing screen roller;

[0144] Step 4: Start the gluing operation of the dry laminating machine, so that the gluing screen roller is at 6g / m 2 The modified polyester polyurethane glue (compounded according to the formula table in Table 1) is applied to the matte surface of the aluminum foil by a mesh roller at a glue application amount of 154 r / min and a glue application mesh roller speed of 154 r / min; aluminum foil A is obtained;

[0145] Step 5: When setting the first dry composite operation, a first entry inclined wrap angle of 8° is formed between the aluminum foil A and the nylon roll entering the composite roller, ensuring that the nylon roll and the aluminum foil A enter the composite roller along the tangent direction on both sides of the composite roller for the first dry composite operation, and controlling the first dry composite operation conditions: the composite tension is 40kg; the composite roller speed is 110r / min; the winding tension is 28kg; the drying temperature is 90°C, and a nylon-aluminum foil composite film is obtained;

[0146] Step 6: Turn over the nylon-aluminum foil composite film so that the bright side of the aluminum foil of the nylon-aluminum foil composite film faces the glue screen roller for the second dry composite operation; and control the glue screen roller to press 15g / m 2 The nylon-aluminum foil composite film is coated with a screen roller at a glue amount of 100 g and a speed of 144 r / min for the glue screen roller, so that the acid-modified polyolefin glue screen roller is coated on the bright surface of the aluminum foil of the nylon-aluminum foil composite film;

[0147] Step 7: feeding the nylon-aluminum foil composite film coated with the acid-modified polyolefin glue in step 6 into the composite roller of the second dry operation, and at the same time, the polypropylene film roll enters the composite roller of the second dry composite operation with a 2kg unwinding tension, and controls the polypropylene film and the nylon-aluminum foil composite film to form a second entry inclined wrap angle of 10°, the composite tension is 40kg; the composite roller speed is 108r / min; the winding tension is 28kg; the drying temperature is 80°C; and a nylon-aluminum foil-polypropylene film composite roll is obtained;

[0148] Step 8: Sleeve the heat-resistant elastic rubber ring on the outer wall of the nylon-aluminum foil-polypropylene film composite roll in step 7, then peel off the release film on the double-sided adhesive layer, and then press the heat-resistant elastic rubber ring provided with the double-sided adhesive layer to make the double-sided adhesive layer stick to the other side of the installation cavity, so that the nylon-aluminum foil-polypropylene film composite roll is located in the elastic restraint cavity;

[0149] Step 9: The nylon-aluminum foil-polypropylene film composite roll fixed in step 8 is sent to a aging box in a horizontal position with the stress release margin cavity facing upward, and is aged at 65° C. for 2 days and 80° C. for 2 days, respectively, to obtain the nylon-aluminum foil-polypropylene film composite roll;

[0150] Step 10: Cut the nylon-aluminum foil-polypropylene film composite roll after the drying and aging operation to obtain the high-drawing aluminum-plastic film of the soft-pack battery.

[0151] Among them, the preparation method of modified polyester polyurethane glue is as follows: first, A-8 is mixed with methyl acetate to obtain a solvent, and then 1 / 3 of the solvent is added to A-622 and stirred evenly; then, HL-76 curing agent is added while stirring evenly to obtain a mixed solution B; then, 1 / 3 kg of solvent is used to clean the curing agent barrel, and the mixed solution B is poured in, and finally the remaining solvent is poured into the mixed solution B, and stirred in one direction for 5 minutes to obtain modified polyester polyurethane glue.

[0152] Preparation method of acid-modified polyolefin glue: first, add 1 / 9 CH4 and 1 / 26 MEK to PMA-KH and stir for 15 minutes to obtain a mixed solution C; then add 8 / 9 CH4 and 25 / 26 MEK to the isocyanate curing agent of Desmodur N3300 and stir evenly for 15 minutes to obtain D; finally, mix C and D together and continue to stir for 10 minutes to obtain acid-modified polyolefin glue.

[0153] Comparative Example 1

[0154] The difference from Example 3 is that the formula of the modified polyester polyurethane glue in step 4 is different, that is, Comparative Example 1 is compounded using the formula of Chinese patent document CN112009067B, and the rest remains unchanged.

[0155] Comparative Example 2

[0156] The difference from Example 3 is that the glue screen roller in step 6 is 3g / m 2 The gluing amount requirement is met; that is, the gluing amount ratio of the traditional outer rubber layer to the inner rubber layer is 2:1, and the rest remains unchanged.

[0157] Comparative Example 3

[0158] The difference from Example 3 is that in step 8, in Example 3, a traditional simple fixing tape is used to fix the nylon-aluminum foil-polypropylene film composite roll, and the rest remains unchanged.

[0159] The high-drawing aluminum-plastic films of the soft-pack batteries prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested for peel strength, electrolyte resistance, and appearance of deep-drawing pits to obtain the test results in Table 2:

[0160] NY / L refers to nylon layer and aluminum foil layer; L / CPP refers to aluminum foil layer and polypropylene film;

[0161] Table 2

[0162]

[0163]

[0164] From the comparison between Examples 1 to 3 and Comparative Examples 1 to 2, it can be seen that since Examples 1 to 3 have optimized the formula of the outer rubber layer (modified polyester polyurethane glue) and used acid-modified polyolefin glue at the same time, it is ensured that Examples 1 to 3 can punch out punching pits that are larger than 11.00 mm, round, wrinkle-free and full.

[0165] From the comparison between Example 3 and Comparative Example 3, it can be seen that since Comparative Example 3 uses traditional simple fixing tape to fix the nylon-aluminum foil-polypropylene film composite roll, the overall aging consistency of the nylon-aluminum foil-polypropylene film composite roll cannot be guaranteed, resulting in partial delamination of the high-drawing aluminum-plastic film obtained by cutting during drawing, accompanied by partial R-corner damage. This shows that the overall aging consistency of the nylon-aluminum foil-polypropylene film composite roll obtained by drying and aging in Comparative Example 3 is poorer than that in Example 3.

[0166] The above-mentioned embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the disclosed patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the disclosed patent shall be subject to the attached claims.

Claims

1. A method for continuous batch production of high-drawing aluminum-plastic film for soft-pack batteries, characterized in that: The steps include: Place the aluminum foil roll and the nylon roll on the dry laminating machine respectively; Feeding the aluminum foil of the aluminum foil roll into the gluing screen roller of the dry laminating machine; The modified polyester polyurethane glue is applied to the aluminum foil by the glue screen roller to obtain aluminum foil A; the modified polyester polyurethane glue comprises the following mass components: 40 to 55 parts of polyester polyol main agent containing hydroxyl end; 7 to 10 parts of polyisocyanate curing agent; 6~8 parts of diluent; The nylon of the nylon roll and the aluminum foil A are subjected to a first dry composite operation to obtain a nylon-aluminum foil composite film; wherein the unwinding tension of the aluminum foil roll is 10kg-15kg; the unwinding tension of the nylon roll is 1.0kg-2.5kg; the winding tension during the first dry composite operation is controlled to be 25kg-32kg to ensure that the winding tension of the aluminum foil roll in the nylon-aluminum foil composite film matches the winding tension of the nylon roll; A second dry compounding operation is performed on the polypropylene film and the nylon-aluminum foil composite film using acid-modified polyolefin glue to obtain a nylon-aluminum foil-polypropylene film composite roll; The acid-modified polyolefin glue comprises the following mass components: 90 to 100 parts of acid-modified polyolefin resin; 1 to 5 parts of aliphatic polyisocyanate curing agent; 10 to 15 parts of methane; 3 to 5 parts of butanone; The glue amount of the modified polyester polyurethane glue and the glue amount of the acid-modified polyolefin glue are (1.0~1.5):(2.0~2.5); the glue amount of the modified polyester polyurethane glue is 6g / m 2 ~9g / m 2 The amount of the acid-modified polyolefin glue is 12g / m 2 ~15g / m 2 ; Performing a drying and aging operation on the nylon-aluminum foil-polypropylene film composite roll; The nylon-aluminum foil-polypropylene film composite roll after drying and aging is cut to obtain the high-drawing aluminum-plastic film of the soft-pack battery.

2. The method for continuous batch production of high-drawing aluminum-plastic film for soft-pack batteries according to claim 1, characterized in that: The drying temperature of the first dry compounding operation is 90°C to 100°C.

3. The method for continuous batch production of high-drawing aluminum-plastic film for soft-pack batteries according to claim 1, characterized in that: The diluent includes at least one of ethyl acetate, dimethyl carbonate and methyl acetate.

4. The method for continuous batch production of high-drawing aluminum-plastic film for soft-pack batteries according to claim 1, characterized in that: The water content of the diluent does not exceed 300 ppm, and the alcohol content does not exceed 200 ppm.

5. The method for continuous batch production of high-drawing aluminum-plastic film for soft-pack batteries according to claim 1, characterized in that: After the step of placing the aluminum foil roll and the nylon roll on the dry laminating machine respectively, and before the step of feeding the aluminum foil of the aluminum foil roll into the gluing screen roller of the dry laminating machine, the following specific steps are also included: Performing a surface pretreatment operation on the aluminum foil to obtain aluminum foil B; The two sides of the aluminum foil B are treated with a surface modifier to form surface protection films on the two sides of the aluminum foil B.

6. A high-drawing aluminum-plastic film for soft-pack batteries, characterized in that: The soft-pack battery is prepared by the method for continuous batch production of high-drawing aluminum-plastic film according to any one of claims 1 to 5.

Images