Metallized film, preparation method and uses

Abstract

The present invention relates to the technical field of metallized films, and specifically relates to a metallized film, a preparation method and uses thereof. The metallized film includes a base layer, an intermediate layer and a copper-plated layer; the intermediate layer is located between the base layer and the copper-plated layer, and the copper-plated layer is processed on the intermediate layer by a laser scanning method. The intermediate layer is an alumina layer, and the intermediate layer is formed on the surface of the pretreated base layer by a vacuum evaporation method, including: performing aluminizing treatment on the surface of the base layer, and then continuously introducing an oxidation gas on the surface of the aluminized layer to form an alumina layer on the surface of the base layer. The above technical solution forms an intermediate layer on the base layer and forms a copper-plated layer on the intermediate layer, improving the bonding force between the base layer and the copper-plated layer. The surface thickness of the copper film formed by the laser scanning method is uniform. Moreover, the copper-plated layer is formed by the laser scanning method without offline operation, improving the production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of metallized films, and particularly relates to a metallized film, a preparation method and uses thereof. Background Art

[0002] As the negative electrode current collector of a lithium battery, copper foil mainly plays the role of carrying the negative electrode active material and collecting current. Traditional copper foil uses 99% high-purity electrolytic copper as the main material, which has problems such as high mass ratio, high cost, and restricting the improvement of the energy density of lithium batteries. Composite copper foil breaks through the bottleneck of traditional copper foil and is a good alternative material for traditional lithium battery current collectors (aluminum foil and copper foil), leading a new round of industrial trends. The essence of composite copper foil is to adopt a metal + polymer film structure and key processes of magnetron sputtering and electroplating, achieving higher energy density, lower cost, and higher safety. However, the thickness of the copper film surface formed by the magnetron plus electroplating process is uneven, and the magnetron sputtering process is an off-line process, resulting in low production efficiency. Summary of the Invention

[0003] The present invention aims to solve the above technical problems.

[0004] An object of the present invention is to provide a metallized film, in which a transition layer is formed on a base layer, and a copper-coated layer is formed on the transition layer, improving the bonding force between the base layer and the copper-coated layer, and the surface thickness of the copper film formed by the laser scanning method is uniform.

[0005] Another object of the present invention is to provide a metallized film, in which the copper-coated layer is formed by the laser scanning method, without off-line operation, improving the production efficiency.

[0006] The present invention provides a metallized film, including a base layer, a transition layer, and a copper-coated layer; the transition layer is located between the base layer and the copper-coated layer, and the copper-coated layer is processed on the transition layer by the laser scanning method; the transition layer is an alumina layer, and the transition layer is formed on the surface of the pretreated base layer by vacuum evaporation, including: performing aluminizing treatment on the surface of the base layer, and then continuously introducing an oxidation gas on the surface of the aluminized layer to form an alumina layer on the surface of the base layer.

[0007] According to an embodiment of the present disclosure, the base layer is a polyester film, a polypropylene film, or a polyimide film.

[0008] According to an embodiment of the present disclosure, the thickness of the copper-coated layer is 1 - 5 μm.

[0009] According to an embodiment of the present disclosure, the laser power used in the laser scanning method is 30 - 50 watts, and the processing rate is 60 - 100 mm / s.

[0010] The present invention also provides a method for preparing a metallized film as described in any one of the above, comprising the following steps:

[0011] Surface pretreatment of the base layer;

[0012] A transition layer is formed on the surface of the pretreated base layer by vacuum evaporation;

[0013] Copper is deposited on the transition layer by laser scanning to form a copper-deposited layer, obtaining the metallized film.

[0014] According to an embodiment of the present disclosure, the step of surface pretreatment of the base layer includes:

[0015] The surface of the base layer is successively pickled, washed with deionized water, and then dried.

[0016] According to an embodiment of the present disclosure, the step of depositing copper on the transition layer by laser scanning to form a copper-deposited layer and obtaining the metallized film includes:

[0017] Copper paste is coated on the transition layer, and after natural leveling, it is dried in an oven;

[0018] The laser power is set to 30 W, the processing rate is 90 - 100 mm / s for the first laser irradiation, and the duration is 1 - 3 minutes;

[0019] After that, the laser power is set to 50 W, the processing rate is 50 - 60 mm / s for the second laser irradiation, and the duration is 5 - 10 minutes, thereby depositing copper on the transition layer to form a copper-deposited layer and obtaining the metallized film.

[0020] The present invention also provides a use of the metallized film as described in any one of the above in a thin film capacitor.

[0021] On the basis of conforming to common general knowledge in the art, the above preferred conditions can be combined arbitrarily to obtain various preferred examples of the present invention.

[0022] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0023] The metallized film provided by the embodiment of the present invention includes a base layer, a transition layer, and a copper-plated layer; the transition layer is located between the base layer and the copper-plated layer, and the copper-plated layer is processed on the transition layer by a laser scanning method; the transition layer is an alumina layer, and the transition layer is formed on the surface of the pretreated base layer by a vacuum evaporation method, including: performing aluminizing treatment on the surface of the base layer, and then continuously introducing an oxidation gas on the surface of the aluminized layer to form an alumina layer on the surface of the base layer. The above technical solution forms a transition layer on the base layer and a copper-plated layer on the transition layer, improving the bonding force between the base layer and the copper-plated layer. The surface thickness of the copper film formed by the laser scanning method is uniform. Moreover, the copper-plated layer is formed by the laser scanning method, eliminating the need for offline operation and improving production efficiency.

[0024] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following specifically illustrates the specific embodiments of the present invention. Specific Embodiments

[0025] The present invention will be further described below by way of examples. However, it can be understood that these specific examples will not limit the scope of the present invention in any way. It should be noted that unless otherwise specified, the raw materials used in the following examples are commercially available products, and their quality meets national standards.

[0026] The embodiment of the present disclosure provides a method for preparing a metallized film, including the following steps:

[0027] Step S1: Pretreat the surface of the base layer;

[0028] Step S2: Form a transition layer on the surface of the pretreated base layer by a vacuum evaporation method;

[0029] Step S3: Deposit copper on the transition layer by a laser scanning method to form a copper-plated layer, obtaining the metallized film.

[0030] According to the embodiment of the present disclosure, the base layer is a polyester film, a polypropylene film, or a polyimide film.

[0031] According to the embodiment of the present disclosure, the transition layer is an aluminized layer, a galvanized layer, or an alumina layer.

[0032] According to the embodiment of the present disclosure, the thickness of the copper-plated layer is 1-5 μm.

[0033] According to the embodiment of the present disclosure, the laser power used in the laser scanning method is 30-50 W, and the processing rate is 60-100 mm / s.

[0034] According to an embodiment of the present disclosure, the step S1 of pre-treating the surface of the base layer includes:

[0035] The surface of the base layer is successively pickled, washed with deionized water, and then dried.

[0036] This step is applicable to the case where the transition layer is an aluminized layer or a galvanized layer. When the transition layer is an alumina layer, this step can also be omitted. Specifically, the base layer is fed into a reduction tank, and a hydrogen sulfide solution is continuously introduced into the reduction tank. The temperature of the hydrogen sulfide solution is 85 - 90 °C. The base layer is fed into a cleaning tank, and deionized water is continuously introduced into the cleaning tank. Then, the base layer is dried at a temperature of 75 - 80 °C. The surface of the base layer is treated with the hydrogen sulfide solution to avoid large-scale oxidation of the transition layer on the surface of the base layer and ensure the bonding force between the base layer and the transition layer.

[0037] According to an embodiment of the present disclosure, the transition layer is an alumina layer;

[0038] The step S2 of forming a transition layer on the surface of the pre-treated base layer by vacuum evaporation includes:

[0039] The surface of the base layer is aluminized, and then an oxidation gas is continuously introduced onto the aluminized layer surface to form an alumina layer on the surface of the base layer.

[0040] Specifically, the base layer is fed into a vacuum coating machine, and an aluminized layer is formed on the working surface of the base layer by vacuum evaporation in the vacuum coating machine. Then, it is fed into a constant temperature oven for surface treatment of the aluminized layer. During the surface treatment of the aluminized layer, an oxidation gas is continuously introduced into the constant temperature oven, and the temperature of the hot air in the constant temperature oven is 100 °C - 105 °C.

[0041] According to an embodiment of the present disclosure, the step S3 of forming a copper-coated layer on the transition layer by laser scanning to obtain a metallized film includes:

[0042] Copper paste is coated on the transition layer. After natural leveling, it is dried in an oven;

[0043] Set the laser power to 30 watts, the processing rate to 90 - 100 mm / s, and perform a single laser irradiation for 1 - 3 minutes;

[0044] After that, set the laser power to 50 watts, the processing rate to 50 - 60 mm / s, and perform a second laser irradiation for 5 - 10 minutes, thereby forming a copper-coated layer on the transition layer to obtain a metallized film.

[0045] Specifically, a certain amount of copper powder is weighed and dispersed in anhydrous ethanol under magnetic stirring until the powder is in a monodisperse state to obtain a copper paste. Then, using the spin coating process, the copper paste is spin-coated on the transition layer formed in step S2. After natural leveling, it is dried in an oven to ensure that the organic components in the copper paste are completely volatilized. After that, a laser beam is used to process the copper metal layer on the surface of the transition layer to achieve the connection between the transition layer and the copper-clad layer.

[0046] The power and irradiation duration of a single laser irradiation should not be too large. After a single laser irradiation, a certain strength of connection is achieved between the copper metal layer and the transition layer. The power and irradiation duration of the second laser irradiation can be appropriately increased, and the laser beam is used to perform secondary processing on the copper metal layer to achieve the purpose of mutual connection between the metals on the surface of the transition layer. In addition, the processing speed should be controlled during the first and second laser irradiations to ensure the flatness of the surface of the copper-clad layer. After testing, the processing speed of the first irradiation is 90 - 100 mm / s, and the processing speed of the second irradiation is 50 - 60 mm / s, and the surface of the copper-clad layer has good flatness. In addition, after the first laser irradiation, the copper metal layer that is not tightly connected to the transition layer can be removed using a dilute hydrochloric acid solution, and then a copper metal layer is deposited on the surface of the copper metal layer after the first laser processing using the natural sedimentation method to adjust the thickness of the copper-clad layer to be controlled within 1 - 5 μm, and then the laser beam is used to perform a second irradiation on the copper metal layer.

[0047] The embodiment of the present disclosure also provides a metallized film, including a base layer, a transition layer, and a copper-clad layer; the transition layer is located between the base layer and the copper-clad layer, and the copper-clad layer is processed on the transition layer using the laser scanning method. By forming a transition layer on the base layer and forming a copper-clad layer on the transition layer, the bonding strength between the base layer and the copper-clad layer is improved. The surface thickness of the copper film formed using the laser scanning method is uniform. Moreover, using the laser scanning method to form the copper-clad layer does not require offline operation, improving production efficiency. Among them, the base layer is a polyester film, a polypropylene film, or a polyimide film. The transition layer is an aluminum-plated layer, a zinc-plated layer, or an aluminum oxide layer. The thickness of the copper-clad layer is 1 - 5 μm. The laser power used in the laser scanning method is 30 - 50 watts, and the processing rate is 60 - 100 mm / s.

[0048] The embodiment of the present disclosure also provides the use of a metallized film as described in any one of the above in a thin film capacitor. Example 1

[0049] Feed the polyester film into the reduction tank, continuously introduce a hydrogen sulfide solution with a mass fraction of 30% into the reduction tank, and the temperature of the hydrogen sulfide solution is 85°C. Feed the polyester film into the cleaning tank, continuously introduce deionized water into the cleaning tank, and then dry the polyester film at a temperature of 75°C. Then feed the polyester film into a vacuum coating machine, and use vacuum evaporation to form a 0.3-μm aluminum coating on the surface of the polyester film. Weigh 3 g of copper powder and disperse it in 70 ml of absolute ethanol under magnetic stirring until the powder is in a monodispersed state to obtain copper paste. Then, using the spin coating process, spin-coat the copper paste on the aluminum coating, control the film thickness to be 1-5 μm, and after natural leveling, dry it in an oven at 120°C to ensure that the organic components in the copper paste are completely volatilized. Set the laser power to 30 W, the processing speed to 90 mm / s for the first laser irradiation for 1 minute; then set the laser power to 50 W, the processing speed to 50 mm / s for the second laser irradiation for 5 minutes, so as to deposit copper on the aluminum coating to form a copper-deposited layer and obtain a metallized film. Example 2

[0050] Feed the polyimide film into the reduction tank, continuously introduce a hydrogen sulfide solution with a mass fraction of 32% into the reduction tank, and the temperature of the hydrogen sulfide solution is 85°C. Feed the polyimide film into the cleaning tank, continuously introduce deionized water into the cleaning tank, and then dry the polyimide film at a temperature of 75°C. Then feed the polyimide film into a vacuum coating machine, and use vacuum evaporation to form a 0.5-μm zinc coating on the surface of the polyimide film. Weigh 3 g of copper powder and disperse it in 70 ml of absolute ethanol under magnetic stirring until the powder is in a monodispersed state to obtain copper paste. Then, using the spin coating process, spin-coat the copper paste on the zinc coating, control the film thickness to be 1-5 μm, and after natural leveling, dry it in an oven at 120°C to ensure that the organic components in the copper paste are completely volatilized. Set the laser power to 30 W, the processing speed to 90 mm / s for the first laser irradiation for 2 minutes; then set the laser power to 50 W, the processing speed to 50 mm / s for the second laser irradiation for 7 minutes, so as to deposit copper on the zinc coating to form a copper-deposited layer and obtain a metallized film. Example 3

[0051] The polyimide film is fed into a reduction tank, and a hydrogen sulfide solution with a mass fraction of 35% is continuously introduced into the reduction tank. The temperature of the hydrogen sulfide solution is 85°C. The polyimide film is then fed into a cleaning tank, and deionized water is continuously introduced into the cleaning tank. Then, the polyimide film is dried at a temperature of 75°C. Subsequently, the polyimide film is fed into a vacuum coating machine, and an aluminum coating is formed on the surface of the polyimide film by vacuum evaporation in the vacuum coating machine. Next, the polyimide film is fed into a constant-temperature oven for surface treatment. During the surface treatment of the aluminum coating, an oxidation gas is continuously introduced into the constant-temperature oven. The oxidation gas can be composed of ozone and carbon dioxide. The temperature of the hot air in the constant-temperature oven is 100°C, and an aluminum oxide layer with a thickness of 0.6 μm is formed on the surface of the polyimide film. Weigh 3 g of copper powder and disperse it in 70 ml of absolute ethanol under magnetic stirring until the powder is in a monodispersed state to obtain copper paste. Then, using the spin coating process, the copper paste is spin-coated on the aluminum oxide layer, and the film thickness is controlled to be 1 - 5 μm. After natural leveling, it is dried in an oven at 120°C to ensure that the organic components in the copper paste are completely volatilized. Set the laser power to 30 W and the processing rate to 90 mm / s for the first laser irradiation for 3 minutes; then set the laser power to 50 W and the processing rate to 50 mm / s for the second laser irradiation for 10 minutes, thereby forming a copper-coated layer on the aluminum oxide layer to obtain a metallized film. Example 4

[0052] The polypropylene film is fed into a reduction tank, and a hydrogen sulfide solution with a mass fraction of 30% is continuously introduced into the reduction tank. The temperature of the hydrogen sulfide solution is 90°C. The polypropylene film is then fed into a cleaning tank, and deionized water is continuously introduced into the cleaning tank. Then, the polypropylene film is dried at a temperature of 80°C. Subsequently, the polypropylene film is fed into a vacuum coating machine, and an aluminum coating is formed on the surface of the polypropylene film by vacuum evaporation in the vacuum coating machine. Next, the polypropylene film is fed into a constant-temperature oven for surface treatment. During the surface treatment of the aluminum coating, an oxidation gas is continuously introduced into the constant-temperature oven. The oxidation gas can be composed of ozone and carbon dioxide. The temperature of the hot air in the constant-temperature oven is 100°C, and an aluminum oxide layer with a thickness of 0.5 μm is formed on the surface of the polypropylene film. Weigh 3 g of copper powder and disperse it in 70 ml of absolute ethanol under magnetic stirring until the powder is in a monodispersed state to obtain copper paste. Then, using the spin coating process, the copper paste is spin-coated on the aluminum oxide layer, and the film thickness is controlled to be 1 - 5 μm. After natural leveling, it is dried in an oven at 120°C to ensure that the organic components in the copper paste are completely volatilized. Set the laser power to 30 W and the processing rate to 100 mm / s for the first laser irradiation for 3 minutes; then set the laser power to 50 W and the processing rate to 60 mm / s for the second laser irradiation for 10 minutes, thereby forming a copper-coated layer on the aluminum oxide layer to obtain a metallized film. Example 5

[0053] Feed the polypropylene film into a reduction tank, continuously introduce a hydrogen sulfide solution with a mass fraction of 30% into the reduction tank, the temperature of the hydrogen sulfide solution is 90 °C, feed the polypropylene film into a cleaning tank, continuously introduce deionized water into the cleaning tank, and then dry the polypropylene film at a temperature of 80 °C. Then feed the polypropylene film into a vacuum coating machine, and use vacuum evaporation to form an aluminized layer on the surface of the polypropylene film in the vacuum coating machine. Then feed the polypropylene film into a constant temperature oven for surface treatment. During the surface treatment of the aluminized layer, continuously introduce an oxidation gas into the constant temperature oven. The oxidation gas can be composed of ozone and carbon dioxide. The temperature of the hot air in the constant temperature oven is 100 °C, and an aluminum oxide layer with a thickness of 0.4 μm is formed on the surface of the polypropylene film. Weigh 3 g of copper powder and disperse it in 70 ml of absolute ethanol under magnetic stirring until the powder is in a monodisperse state to obtain a copper paste. Then, using the spin coating process, spin-coat the copper paste on the aluminum oxide layer, and control the film thickness to 2 μm. After natural leveling, dry it in an oven at 120 °C to ensure that the organic components in the copper paste are completely volatilized. Set the laser power to 30 W, the processing speed to 100 mm / s, and perform a single laser irradiation for 3 minutes. Then use a dilute hydrochloric acid solution to remove the copper metal layer that is not tightly connected to the transition layer, and then use the natural sedimentation method to deposit a layer of copper metal layer on the surface of the copper metal layer after the first laser processing to adjust the thickness of the copper-plated layer, controlling it within 1 - 5 μm. Then set the laser power to 50 W, the processing speed to 60 mm / s, and perform a second laser irradiation for 10 minutes, so as to form a copper-plated layer on the aluminum oxide layer to obtain a metallized film.

[0054] For the metallized film obtained in the above embodiment, by forming a transition layer on the base layer and forming a copper-plated layer on the transition layer, the bonding strength between the base layer and the copper-plated layer is improved. The surface thickness of the copper film formed by the laser scanning method is uniform. Moreover, using the laser scanning method to form the copper-plated layer does not require offline operation, which improves the production efficiency.

[0055] Test the performance of the metallized films prepared in the above Examples 1 - 5. Among them, the test method for surface peel strength is JIS-C-6481, and the film thickness is measured using a film thickness gauge from Xi'an Xingyue Company. The test method is to select 3 - 5 test points on the film surface, measure the film thickness at the test points, and calculate the maximum thickness error. The results are shown in the following table:

[0056]

[0057] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention; any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above, or modify it into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A metallized film, characterized in that, it comprises a base layer, a transition layer and a copper-plated layer; the base layer is a polyester film, a polypropylene film or a polyimide film; the transition layer is located between the base layer and the copper-plated layer, and the copper-plated layer is processed on the transition layer by a laser scanning method; the transition layer is an alumina layer, and the transition layer is formed on the surface of the pretreated base layer by a vacuum evaporation method, including: performing aluminizing treatment on the surface of the base layer, and then continuously introducing an oxidizing gas on the surface of the aluminized layer to form an alumina layer on the surface of the base layer; the step of forming a copper-plated layer on the transition layer by using a laser scanning method to obtain a metallized film includes: coating copper paste on the transition layer, waiting for natural leveling, and then drying in an oven; setting the laser power to 30 watts, the processing speed to 90-100 mm / s for the first laser irradiation, and the duration to 1-3 minutes; then setting the laser power to 50 watts, the processing speed to 50-60 mm / s for the second laser irradiation, and the duration to 5-10 minutes, so as to form a copper-plated layer on the transition layer to obtain a metallized film.

2. The metallized film according to claim 1, characterized in that, the thickness of the copper-plated layer is 1-5 μm.

3. The preparation method of the metallized film according to any one of claims 1-2, characterized in that, it comprises the following steps: Pretreating the surface of the base layer; Forming a transition layer on the surface of the pretreated base layer by a vacuum evaporation method; Forming a copper-plated layer on the transition layer by using a laser scanning method to obtain a metallized film.

4. The preparation method of the metallized film according to claim 3, characterized in that, the step of pretreating the surface of the base layer includes: Sequentially pickling, washing with deionized water and then drying the surface of the base layer.

5. The use of the metallized film according to any one of claims 1-2 in a film capacitor.

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