Hot-method aluminum-plastic film process

Abstract

The invention relates to the technical field of lithium ion battery flexible packaging, in particular to a hot-method aluminum-plastic film process which comprises the following steps: treating grease attached to the surface of an aluminum foil, uniformly coating the aluminum foil with glue, and sequentially drying at three temperature intervals of 75 DEG C, 85 DEG C and 100 DEG C to obtain the pretreated aluminum foil; dry compounding of nylon and aluminum foil; coating the corona surface of the CPP film with an adhesive to obtain a pretreated CPP film; volatilizing a solvent from the pretreated CPP film in a drying oven, and performing hot-pressing compounding on the pretreated CPP film and a PA / Al composite film to obtain a composite aluminum-plastic film; and quenching the composite aluminum-plastic film by using a cold roller, and rolling and cutting after the composite aluminum-plastic film reaches the room temperature to obtain a finished product. According to the hot-method aluminum-plastic film process, the peel strength and the heat sealing strength between the film layers are effectively improved, the production period is shorter, more energy is saved, the working efficiency is improved, and the process is simple, easy to implement, low in production cost, low in requirements for compounding and storage processes and suitable for application and popularization.

Description

Technical Field

[0001] The invention relates to the technical field of lithium ion battery soft packaging, in particular to a thermal aluminum-plastic film process. Background Art

[0002] Lithium-ion power batteries are known as the "green chemical energy" of the 21st century and have been widely used in many fields such as 3C consumer electronics, power batteries, and energy storage. As a key material for soft-pack lithium-ion batteries, aluminum-plastic film contains a high technological content. The performance of aluminum-plastic film directly determines the quality of lithium-ion batteries. Aluminum-plastic film can be roughly divided into three layers: the inner layer is the bonding layer, which is mostly made of polypropylene material and plays a sealing and bonding role; the middle layer is aluminum foil, which can prevent the penetration of water vapor outside the battery and prevent the leakage of internal electrolyte; the outer layer is the protective layer, which is mostly made of high-melting-point nylon material with strong mechanical properties to prevent external force from damaging the battery and protect the battery.

[0003] The research and development of high-quality aluminum-plastic film is the key to the successful development of soft-pack lithium-ion batteries, a high-tech product. As the shell of soft-pack lithium-ion batteries, it is an indispensable and important component of soft-pack lithium-ion batteries. At present, the two main processes of thermal composite and dry composite are used to prepare composite aluminum-plastic film. The thermal composite process refers to the thermal composite of aluminum foil and heat-sealing layer CPP film material using hot melt adhesive as a binder. The advantages are good weather resistance, no need to use a large amount of organic solvents in the production process, more environmentally friendly, and more suitable for large-scale continuous production. However, the traditional thermal composite process requires high-temperature hot pressing and bonding, which leads to damage to the flexibility of the substrate, and requires high-temperature aging and storage, which is time-consuming and energy-consuming. Therefore, we proposed a thermal aluminum-plastic film process. Summary of the invention

[0004] The main purpose of the present invention is to provide a thermal aluminum-plastic film process, which can effectively solve the problems in the background technology.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A thermal aluminum-plastic film process comprises the following steps:

[0007] S1. Aluminum foil pretreatment: treat the grease attached to the surface of the aluminum foil, evenly coat the aluminum foil with glue, and sequentially dry it at three temperature intervals of 75°C, 85°C, and 100°C to obtain the pretreated aluminum foil;

[0008] S2. Dry-type compounding of nylon and aluminum foil: dry-type compounding of the corona-treated nylon material and the pre-treated aluminum foil by a compounding machine, compounding the nylon material on the aluminum foil, curing and forming, and winding after cooling to obtain a PA / Al composite film;

[0009] S3, CPP film pretreatment: applying adhesive to the corona surface of the CPP film to obtain a pretreated CPP film;

[0010] S4, hot-pressing and compounding the CPP film and the PA / Al composite film: volatilizing the solvent of the pretreated CPP film in an oven, and hot-pressing and compounding it with the PA / Al composite film to obtain a composite aluminum-plastic film;

[0011] S5, obtaining the finished product: using a cold roller to quench the composite aluminum-plastic film, and then rolling and cutting it to room temperature to obtain the finished product.

[0012] Preferably, in S1, the glue is a modified polyurethane glue, and the coating amount of the glue is 5-12 g / m 2 .

[0013] Preferably, the modified polyurethane glue is prepared by dissolving polyester / ether polyol, carbon nanotubes, polyisocyanate and additives in ethyl acetate.

[0014] Preferably, in S2, the temperature of the dry compounding is 75-80°C.

[0015] Preferably, in S3, the post-corona dyne value of the corona surface of the CPP film is 30-50.

[0016] Preferably, in S3, the adhesive composition comprises, by mass, 1-50 parts of a main resin, 1-30 parts of a curing agent, 0.1-5 parts of an adhesion promoter, and 40-80 parts of a solvent.

[0017] Preferably, the main resin includes chlorinated polypropylene butene and maleic anhydride grafted modified polypropylene butene, and the mass ratio of chlorinated polypropylene butene to maleic anhydride grafted modified polypropylene butene is 5:3.

[0018] Preferably, the curing agent is a blocked isocyanate, the adhesion promoter is any one of a silane additive, a phosphoric acid derivative, and a phosphonic acid derivative, and the solvent includes cyclohexane and toluene, and the mass ratio of cyclohexane to toluene is 1:2.

[0019] Preferably, in S4, the actual coating amount of the adhesive on the pretreated CPP film after oven drying is 1.0-3.0 g / m2.

[0020] Preferably, in S4, the pre-treated CPP film and the PA / Al composite film are composited at a temperature of 110-150° C. and a pressure of 0.1-1.5 MPa.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The aluminum foil and nylon, as well as the PA / Al composite film and the CPP film of the present invention are bonded by a specific adhesive, a composite process and a drying method, which effectively improves the peel strength and heat sealing strength between the film layers. After the above treatment, the composite aluminum-plastic film product does not need to be stored at a high temperature offline, the production cycle is shorter, more energy-saving, and the work efficiency is improved.

[0023] 2. The present invention effectively solves the defect of short storage time of prepared adhesive by adjusting the main resin, curing agent and adhesion promoter. At the same time, by adding adhesion promoter, the long-term corrosion resistance of electrolyte under water conditions can be effectively improved. By combining the advantages of thermal composite and dry composite production, the effect of using dry composite materials to produce by thermal composite production process is achieved, which not only shortens the production cycle, but also ensures the initial bonding strength.

[0024] 3. The composite process of the present invention does not require high-temperature hot-pressing bonding, will not damage the flexibility of substrates such as nylon and aluminum foil, effectively maintains the stamping forming performance and product appearance of the composite aluminum-plastic film, and the obtained composite aluminum-plastic film has excellent electrolyte resistance, tensile properties, peel strength and other properties.

[0025] 4. The process of the present invention is simple, easy to implement, has low production cost, has low requirements on compounding and storage processes, and is suitable for popularization and application. DETAILED DESCRIPTION

[0026] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0027] Example 1

[0028] A thermal aluminum-plastic film process comprises the following steps:

[0029] S1. Aluminum foil pretreatment: treat the grease attached to the surface of the aluminum foil, evenly coat the aluminum foil with glue, and sequentially dry it at three temperature intervals of 75°C, 85°C, and 100°C to obtain the pretreated aluminum foil;

[0030] The glue is modified polyurethane glue, and the coating amount of the glue is 5g / m 2 .

[0031] The modified polyurethane glue is prepared by dissolving polyester / ether polyol, carbon nanotubes, polyisocyanate and an auxiliary agent in ethyl acetate.

[0032] S2. Dry-type compounding of nylon and aluminum foil: dry-type compounding of the corona-treated nylon material and the pre-treated aluminum foil by a compounding machine, compounding the nylon material on the aluminum foil, curing and forming, and winding after cooling to obtain a PA / Al composite film;

[0033] Wherein, the temperature of the dry compounding is 75°C.

[0034] S3, CPP film pretreatment: applying adhesive to the corona surface of the CPP film to obtain a pretreated CPP film;

[0035] Wherein, the post-corona dyne value of the corona surface of the CPP film is 30.

[0036] The adhesive composition includes, by mass, 1 part of main resin, 1 part of curing agent, 0.1 part of adhesion promoter and 40 parts of solvent.

[0037] The main resin includes chlorinated polypropylene butene and maleic anhydride grafted modified polypropylene butene, and the mass ratio of chlorinated polypropylene butene to maleic anhydride grafted modified polypropylene butene is 5:3.

[0038] Wherein, the curing agent is a blocked isocyanate, the adhesion promoter is a silane additive, the solvent includes cyclohexane and toluene, and the mass ratio of cyclohexane to toluene is 1:2.

[0039] S4, hot-pressing and compounding the CPP film and the PA / Al composite film: volatilizing the solvent of the pretreated CPP film in an oven, and hot-pressing and compounding it with the PA / Al composite film to obtain a composite aluminum-plastic film;

[0040] The actual coating amount of the adhesive on the pretreated CPP film after oven drying is 1.0 g / m 2 .

[0041] The pre-treated CPP film and the PA / Al composite film are composited at a temperature of 110° C. and a pressure of 0.1 MPa.

[0042] S5, obtaining the finished product: using a cold roller to quench the composite aluminum-plastic film, and then rolling and cutting it to room temperature to obtain the finished product.

[0043] Example 2

[0044] A thermal aluminum-plastic film process comprises the following steps:

[0045] S1. Aluminum foil pretreatment: treat the grease attached to the surface of the aluminum foil, evenly coat the aluminum foil with glue, and sequentially dry it at three temperature intervals of 75°C, 85°C, and 100°C to obtain the pretreated aluminum foil;

[0046] The glue is modified polyurethane glue, and the coating amount of the glue is 12g / m 2 .

[0047] The modified polyurethane glue is prepared by dissolving polyester / ether polyol, carbon nanotubes, polyisocyanate and an auxiliary agent in ethyl acetate.

[0048] S2. Dry-type compounding of nylon and aluminum foil: dry-type compounding of the corona-treated nylon material and the pre-treated aluminum foil by a compounding machine, compounding the nylon material on the aluminum foil, curing and forming, and winding after cooling to obtain a PA / Al composite film;

[0049] Wherein, the temperature of the dry compounding is 80°C.

[0050] S3, CPP film pretreatment: applying adhesive to the corona surface of the CPP film to obtain a pretreated CPP film;

[0051] Wherein, the post-corona dyne value of the corona surface of the CPP film is 50.

[0052] The adhesive composition comprises, by mass, 50 parts of a main resin, 30 parts of a curing agent, 5 parts of an adhesion promoter and 80 parts of a solvent.

[0053] The main resin includes chlorinated polypropylene butene and maleic anhydride grafted modified polypropylene butene, and the mass ratio of chlorinated polypropylene butene to maleic anhydride grafted modified polypropylene butene is 5:3.

[0054] Wherein, the curing agent is a blocked isocyanate, the adhesion promoter is a phosphoric acid derivative, the solvent includes cyclohexane and toluene, and the mass ratio of cyclohexane to toluene is 1:2.

[0055] S4, hot-pressing and compounding the CPP film and the PA / Al composite film: volatilizing the solvent of the pretreated CPP film in an oven, and hot-pressing and compounding it with the PA / Al composite film to obtain a composite aluminum-plastic film;

[0056] The actual coating amount of the adhesive on the pretreated CPP film after oven drying is 3.0 g / m 2 .

[0057] The pre-treated CPP film and the PA / Al composite film are composited at a temperature of 150° C. and a pressure of 1.5 MPa.

[0058] S5, obtaining the finished product: using a cold roller to quench the composite aluminum-plastic film, and then rolling and cutting it to room temperature to obtain the finished product.

[0059] Example 3

[0060] A thermal aluminum-plastic film process comprises the following steps:

[0061] S1. Aluminum foil pretreatment: treat the grease attached to the surface of the aluminum foil, evenly coat the aluminum foil with glue, and sequentially dry it at three temperature intervals of 75°C, 85°C, and 100°C to obtain the pretreated aluminum foil;

[0062] The glue is modified polyurethane glue, and the coating amount of the glue is 8g / m 2 .

[0063] The modified polyurethane glue is prepared by dissolving polyester / ether polyol, carbon nanotubes, polyisocyanate and an auxiliary agent in ethyl acetate.

[0064] S2. Dry-type compounding of nylon and aluminum foil: dry-type compounding of the corona-treated nylon material and the pre-treated aluminum foil by a compounding machine, compounding the nylon material on the aluminum foil, curing and forming, and winding after cooling to obtain a PA / Al composite film;

[0065] Wherein, the temperature of the dry compounding is 78°C.

[0066] S3, CPP film pretreatment: applying adhesive to the corona surface of the CPP film to obtain a pretreated CPP film;

[0067] Wherein, the post-corona dyne value of the corona surface of the CPP film is 40.

[0068] The adhesive composition includes, by mass, 25 parts of a main resin, 15 parts of a curing agent, 2.8 parts of an adhesion promoter and 60 parts of a solvent.

[0069] The main resin includes chlorinated polypropylene butene and maleic anhydride grafted modified polypropylene butene, and the mass ratio of chlorinated polypropylene butene to maleic anhydride grafted modified polypropylene butene is 5:3.

[0070] Wherein, the curing agent is a blocked isocyanate, the adhesion promoter is a phosphonic acid derivative, the solvent includes cyclohexane and toluene, and the mass ratio of cyclohexane to toluene is 1:2.

[0071] S4, hot-pressing and compounding the CPP film and the PA / Al composite film: volatilizing the solvent of the pretreated CPP film in an oven, and hot-pressing and compounding it with the PA / Al composite film to obtain a composite aluminum-plastic film;

[0072] The actual coating amount of the adhesive on the pretreated CPP film after oven drying is 2.0 g / m 2 .

[0073] The pre-treated CPP film and the PA / Al composite film are composited at a temperature of 130° C. and a pressure of 0.7 MPa.

[0074] S5, obtaining the finished product: using a cold roller to quench the composite aluminum-plastic film, and then rolling and cutting it to room temperature to obtain the finished product.

[0075] The invention provides a thermal aluminum-plastic film process, in which aluminum foil and nylon, as well as PA / Al composite film and CPP film are bonded by a specific adhesive, composite process and drying method, which effectively improves the peel strength and heat sealing strength between the film layers. After the above treatment, the composite aluminum-plastic film product does not need to be stored at high temperature offline, so the production cycle is shorter, more energy-saving and work efficiency is improved. By adjusting the main resin, curing agent and adhesion promoter, the defect of short storage time of the prepared adhesive is effectively solved. At the same time, by adding the adhesion promoter, the long-term corrosion resistance of the electrolyte under water conditions can be effectively improved. , and combined with the advantages of hot composite and dry composite production, the effect of using dry composite materials to produce by hot composite production process is achieved, which not only shortens the production cycle, but also ensures the initial bonding strength; the composite process does not require high-temperature hot pressing and bonding, and will not damage the flexibility of substrates such as nylon and aluminum foil, effectively maintaining the stamping forming performance and product appearance of the composite aluminum-plastic film, and the obtained composite aluminum-plastic film has excellent electrolyte resistance, tensile properties, peel strength and other properties; the process is simple, easy to implement, low production cost, low requirements for the composite and storage process, and suitable for promotion and application.

[0076] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A thermal aluminum-plastic film process, characterized in that: The steps include: S1. Aluminum foil pretreatment: treat the grease attached to the surface of the aluminum foil, evenly coat the aluminum foil with glue, and sequentially dry it at three temperature intervals of 75°C, 85°C, and 100°C to obtain the pretreated aluminum foil; S2. Dry-type compounding of nylon and aluminum foil: dry-type compounding of the corona-treated nylon material and the pre-treated aluminum foil by a compounding machine, compounding the nylon material on the aluminum foil, curing and forming, and winding after cooling to obtain a PA / Al composite film; S3, CPP film pretreatment: applying adhesive to the corona surface of the CPP film to obtain a pretreated CPP film; S4, hot-pressing and compounding the CPP film and the PA / Al composite film: volatilizing the solvent of the pretreated CPP film in an oven, and hot-pressing and compounding it with the PA / Al composite film to obtain a composite aluminum-plastic film; S5, obtaining the finished product: using a cold roller to quench the composite aluminum-plastic film, and then rolling and cutting it to room temperature to obtain the finished product.

2. A thermal aluminum-plastic film process according to claim 1, characterized in that: In S1, the glue is a modified polyurethane glue, and the coating amount of the glue is 5-12g / m 2 .

3. A thermal aluminum-plastic film process according to claim 2, characterized in that: The modified polyurethane glue is prepared by dissolving polyester / ether polyol, carbon nanotubes, polyisocyanate and an auxiliary agent in ethyl acetate.

4. A thermal aluminum-plastic film process according to claim 1, characterized in that: In S2, the temperature of the dry compounding is 75-80°C.

5. A thermal aluminum-plastic film process according to claim 4, characterized in that: In S3, the post-corona dyne value of the corona surface of the CPP film is 30-50.

6. A thermal aluminum-plastic film process according to claim 1, characterized in that: In S3, the adhesive composition includes, by mass, 1-50 parts of a main resin, 1-30 parts of a curing agent, 0.1-5 parts of an adhesion promoter, and 40-80 parts of a solvent.

7. A thermal aluminum-plastic film process according to claim 6, characterized in that: The main resin includes chlorinated polypropylene butene and maleic anhydride grafted modified polypropylene butene, and the mass ratio of chlorinated polypropylene butene to maleic anhydride grafted modified polypropylene butene is 5:

3.

8. A thermal aluminum-plastic film process according to claim 6, characterized in that: The curing agent is a blocked isocyanate, the adhesion promoter is any one of a silane additive, a phosphoric acid derivative, and a phosphonic acid derivative, and the solvent includes cyclohexane and toluene, and the mass ratio of cyclohexane to toluene is 1:

2.

9. A thermal aluminum-plastic film process according to claim 1, characterized in that: In S4, the actual coating amount of the adhesive on the pretreated CPP film after drying in the oven is 1.0-3.0 g / m2.

10. A thermal aluminum-plastic film process according to claim 1, characterized in that: In S4, the pre-treated CPP film and the PA / Al composite film are composited at a temperature of 110-150° C. and a pressure of 0.1-1.5 MPa.