阅读说明：本技术 一种双面铝金属化聚丙烯薄膜及其制备方法和电容器芯子 (Double-sided aluminum metalized polypropylene film, preparation method thereof and capacitor core ) 是由 韩秋城 古骏 杨峰 于 2019-09-29 设计创作，主要内容包括：本发明涉及一种双面铝金属化聚丙烯薄膜及其制备方法和电容器芯子。一种双面铝金属化聚丙烯薄膜包括聚丙烯基膜和两对铝金属化层；一种双面铝金属化聚丙烯薄膜的制备方法包括第一次真空蒸镀、未电晕面电晕、第二次真空蒸镀和后处理；一种电容器芯子包括成对单面金属化聚丙烯薄膜、聚丙烯光膜和双面铝金属化聚丙烯薄膜。本发明的双面铝金属化聚丙烯薄膜,其具有提高薄膜的耐电压能力的优点；另外,本发明的制备方法具有在聚丙烯薄膜两表面均匀蒸镀铝金属化层的优点；本发明的电容器芯子具有提高热聚合效果的优点。(The invention relates to a double-sided aluminum metalized polypropylene film, a preparation method thereof and a capacitor core. A double-sided aluminum metallized polypropylene film comprises a polypropylene base film and two pairs of aluminum metallized layers; a preparation method of a double-sided aluminum metalized polypropylene film comprises the steps of first vacuum evaporation, corona of a non-corona surface, second vacuum evaporation and post-treatment; a capacitor core includes a pair of single-sided metallized polypropylene films, a polypropylene light film, and a double-sided aluminum metallized polypropylene film. The double-sided aluminum metalized polypropylene film has the advantage of improving the voltage resistance of the film; in addition, the preparation method has the advantages that the aluminum metalized layers are uniformly evaporated on the two surfaces of the polypropylene film; the capacitor core of the invention has the advantage of improving the thermal polymerization effect.)

1. A two-sided aluminium metallized polypropylene film is characterized in that: the method is characterized in that: including the polypropylene base film, two surfaces of polypropylene base film all closely paste and are equipped with two aluminium metallization layers that set up side by side, same surface leave the limit in the middle of the strip interval formation between the aluminium metallization layer.

2. The double-sided aluminum metallized polypropylene film of claim 1, wherein: the total thickness of the double-sided aluminum metallized polypropylene film is 4.6-5.0 μm; wherein the sheet resistance of the aluminum metallization layer is 1.0 omega/□ -2.0 omega/□.

3. The double-sided aluminum metallized polypropylene film of claim 1, wherein: the width of the middle margin is 2.8mm-3.2 mm.

4. The method for preparing a double-sided aluminum metallized polypropylene film according to any one of claims 1 to 3, wherein: comprises the following steps of (a) carrying out,

s1 first vacuum evaporation: carrying out vacuum evaporation treatment on the corona surface on one side of the polypropylene base film, and evaporating an aluminum metalized layer on the corona surface on one side of the polypropylene base film to obtain a single-side aluminum metalized polypropylene film;

s2 corona of non-corona surface: taking a single-side aluminum metallized polypropylene film, firstly carrying out plasma pretreatment on the non-corona surface of the polypropylene base film, then carrying out corona treatment on the non-corona surface on the other side, and processing the non-corona surface into a corona surface to obtain a semi-finished film;

s3 second vacuum evaporation: taking a semi-finished product film, carrying out vacuum evaporation treatment on the corona surface on the other side of the polypropylene base film, and evaporating an aluminum metalized layer on the corona surface on the other side of the polypropylene base film to obtain a double-sided aluminum metalized polypropylene film semi-finished product;

and S4 post-processing: and carrying out aging and slitting treatment on the semi-finished product of the double-sided aluminum metallized polypropylene film to obtain the double-sided aluminum metallized polypropylene film.

5. The method for preparing a double-sided aluminum metallized polypropylene film according to claim 4, wherein the method comprises the following steps: in first vacuum evaporation plating and corona surface corona, all carry out following processing to the polypropylene base film in advance, install the polypropylene base film in vacuum environment, and vacuum is 4mbar-10 mbar.

6. The method for preparing a double-sided aluminum metallized polypropylene film according to claim 5, wherein the method comprises the following steps: the vacuum evaporation treatment comprises the following steps of,

s1 oil spray screen: heating an oil pot and an oil baffle plate, wherein shielding oil is sprayed to the corona surface of the polypropylene base film at intervals by the oil pot, the shielding oil is attached to the corona surface of the polypropylene base film through the oil baffle plate, and the spraying width of the shielding oil is 2.8mm-3.2 mm;

s2 main roll cooling: opening a refrigerating device, controlling the temperature of a refrigerating main roller to be-15-10 ℃, and cooling the polypropylene base film through the refrigerating main roller;

s3 vacuum evaporation: heating the evaporation boat, wherein the aluminum wire evaporated on the evaporation boat is attached to the corona surface of the polypropylene base film, and an aluminum metallization layer is formed;

s4 releasing the vacuum: and closing the vacuum pump, and releasing the vacuum to ensure that the pressure of the vacuum winding chamber is equal to the atmospheric pressure.

7. The method for preparing a double-sided aluminum metallized polypropylene film according to claim 6, wherein the method comprises the following steps: in the oil spraying screen belt step, the temperature of an oil can is 170 ℃, and the temperature of an oil baffle plate is 175 ℃.

8. The method for preparing a double-sided aluminum metallized polypropylene film according to claim 4, wherein the method comprises the following steps: in the step of plasma pretreatment, a plasma generator is adopted to spray plasma jet to the corona-free surface of the polypropylene basal membrane, and the outlet temperature of a nozzle of the plasma generator is 250-350 ℃.

9. The method for preparing a double-sided aluminum metallized polypropylene film according to claim 4, wherein the method comprises the following steps: the corona treatment step is specifically realized in a way that a mono-surface aluminum metallized polypropylene film passes through a space between polar plates with high voltage, and bombards the non-corona surface of a polypropylene base film by high voltage; wherein the bombardment intensity of the polar plate is 9.8 W.min/m-10.2 W.min/m.

10. A capacitor core, comprising: comprising a pair of single-sided metallized polypropylene films disposed side-by-side, a polypropylene optical film disposed between the single-sided metallized polypropylene films, and a double-sided aluminum metallized polypropylene film according to any one of claims 1 to 3.

Technical Field

The invention relates to the technical field of capacitors, in particular to a double-sided aluminum metalized polypropylene film, a preparation method thereof and a capacitor core.

Background

At present, the film capacitor market scale in China is small in whole, the film capacitor industry is developed rapidly in recent years, and particularly the downstream demand market is increased rapidly. In recent years, the system and the weight of the capacitor are reduced by 3-4 times, and meanwhile, the film plating technology and the cutting technology of a metallized film are improved, so that the development of film capacitance is greatly facilitated. In the field of double-sided evaporation metallized films, capacitors made of the films occupy more and more markets due to the advantages of small volume, large capacity, good stability, strong self-healing capability and the like. However, domestic enterprises are very concerned with the problems of great difficulty in coating and slitting processes, difficulty in controlling yield and the like. Therefore, in order to meet the market demand and the domestic demand for the development of thin film capacitors, it is necessary to develop a double-sided vapor-deposited metallized thin film having excellent performance.

The capacitor made of the common metallized film can not bear large current, the capacitor made of the metal foil can bear the large current but has no self-healing function, and the existing double-sided metallized polyester film on the market can bear larger current and has the self-healing function. In addition, because the polypropylene film has stronger dielectric strength and higher withstand voltage compared with the polyester film under the same thickness and environment. And the capacitor made of the polypropylene film has small dielectric loss. Therefore, the core double-sided metallized polyester film of the prior film capacitor is formed by overlapping and winding the single-sided metallized film and the light film.

However, because the polyester film and the polypropylene film have different physical properties, especially different thermal shrinkage ratios, if the three films are used to manufacture the capacitor core, the polyester film and the polypropylene film have poor thermal polymerization effect when the capacitor core is subjected to a hot-pressing process, which causes incompact compression between layers of the core, air exists between the films, oxidation of the acceleration metallization layer affects the performance and service life of the capacitor.

Therefore, if a double-sided vapor-deposited polypropylene film can be used instead of a double-sided vapor-deposited polyester film, all the substrates of the capacitor core are polypropylene films, the heat shrinkage ratio is the same, and the core is more effective in thermal polymerization at the time of hot pressing, which can solve the problem. Therefore, the market urgently needs to replace the double-sided vapor-deposited polyester film with the double-sided vapor-deposited polypropylene film.

Because the aluminum metallization layer is evaporated on the surface of the polypropylene, the surface of the polypropylene needs to be subjected to corona treatment, otherwise, the evaporated aluminum cannot be attached to the surface of the polypropylene film under a high vacuum condition. However, at present, manufacturers of polypropylene films for capacitors can only perform corona treatment on one side of the polypropylene film. Moreover, because the evaporated metal film layer is quite thin, how to uniformly evaporate the metal film layer is also a problem to be solved.

Disclosure of Invention

In view of the defects of the prior art, the first object of the present invention is to provide a double-sided aluminum metallized polypropylene film, which has the advantage of improving the voltage resistance of the film.

The second objective of the present invention is to provide a method for preparing a double-sided aluminum metalized polypropylene film, which solves the problem of depositing a layer of aluminum metalized layer on both sides of the polypropylene film, and has the advantage of uniformly depositing an aluminum metalized layer.

The third objective of the present invention is to provide a capacitor core, wherein each layer is made of polypropylene film, which has the advantage of improving the thermal polymerization effect.

In order to achieve the first object, the invention provides the following technical scheme:

a two-sided aluminium metallized polypropylene film is characterized in that: including the polypropylene base film, two surfaces of polypropylene base film all closely paste and are equipped with two aluminium metallization layers that set up side by side, same surface leave the limit in the middle of the strip interval formation between the aluminium metallization layer.

The invention is further configured to: the total thickness of the double-sided aluminum metallized polypropylene film is 4.6-5.0 μm; wherein the sheet resistance of the aluminum metallization layer is 1.0 omega/□ -2.0 omega/□.

The invention is further configured to: the width of the middle margin is 2.8mm-3.2 mm.

By adopting the technical scheme, the polypropylene base film is used for playing a role of a medium, the two aluminum metallization layers are used for conducting electricity and storing charges, and compared with a single metal layer or other metals, the charges stored in the aluminum metallization layer in unit area are increased, so that the storage capacity is high, and the voltage resistance is strong; meanwhile, the design of reserving edges in two sides is adopted, and the manufactured capacitor is equivalent to two capacitors which are connected in series, so that the voltage resistance of the capacitor is further improved.

In order to achieve the second object, the invention provides the following technical scheme:

a preparation method of a double-sided aluminum metalized polypropylene film is characterized by comprising the following steps: comprises the following steps of (a) carrying out,

s1 first vacuum evaporation: carrying out vacuum evaporation treatment on the corona surface on one side of the polypropylene base film, and evaporating an aluminum metalized layer on the corona surface on one side of the polypropylene base film to obtain a single-side aluminum metalized polypropylene film;

s2 corona of non-corona surface: taking a single-side aluminum metallized polypropylene film, firstly carrying out plasma pretreatment on the non-corona surface of the polypropylene base film, then carrying out corona treatment on the non-corona surface on the other side, and processing the non-corona surface into a corona surface to obtain a semi-finished film;

s3 second vacuum evaporation: taking a semi-finished product film, carrying out vacuum evaporation treatment on the corona surface on the other side of the polypropylene base film, and evaporating an aluminum metalized layer on the corona surface on the other side of the polypropylene base film to obtain a double-sided aluminum metalized polypropylene film semi-finished product;

and S4 post-processing: and carrying out aging and slitting treatment on the semi-finished product of the double-sided aluminum metallized polypropylene film to obtain the double-sided aluminum metallized polypropylene film.

The invention is further configured to: in first vacuum evaporation plating and corona surface corona, all carry out following processing to the polypropylene base film in advance, install the polypropylene base film in vacuum environment, and vacuum is 4mbar-10 mbar.

The invention is further configured to: the vacuum evaporation treatment comprises the following steps of,

s1 oil spray screen: heating an oil pot and an oil baffle plate, wherein shielding oil is sprayed to the corona surface of the polypropylene base film at intervals by the oil pot, the shielding oil is attached to the corona surface of the polypropylene base film through the oil baffle plate, and the spraying width of the shielding oil is 2.8mm-3.2 mm;

s2 main roll cooling: opening a refrigerating device, controlling the temperature of a refrigerating main roller to be-15-10 ℃, and cooling the polypropylene base film through the refrigerating main roller;

s3 vacuum evaporation: heating the evaporation boat, wherein the aluminum wire evaporated on the evaporation boat is attached to the corona surface of the polypropylene base film, and an aluminum metallization layer is formed;

s4 releasing the vacuum: and closing the vacuum pump, and releasing the vacuum to ensure that the pressure of the vacuum winding chamber is equal to the atmospheric pressure.

The invention is further configured to: in the oil spraying screen belt step, the temperature of an oil can is 170 ℃, and the temperature of an oil baffle plate is 175 ℃.

The invention is further configured to: in the step of plasma pretreatment, a plasma generator is adopted to spray plasma jet to the corona-free surface of the polypropylene basal membrane, and the outlet temperature of a nozzle of the plasma generator is 250-350 ℃.

The invention is further configured to: the corona treatment step is specifically realized in a way that a mono-surface aluminum metallized polypropylene film passes through a space between polar plates with high voltage, and bombards the non-corona surface of a polypropylene base film by high voltage; wherein the bombardment intensity of the polar plate is 9.8 W.min/m-10.2 W.min/m.

By adopting the technical scheme, in order to ensure that the aluminum metalized layer can be smoothly and firmly attached to the corona-free surface of the polypropylene film, when the corona-free surface of the polypropylene film is subjected to evaporation coating, the corona-free surface of the polypropylene film is subjected to plasma pretreatment, so that gaseous aluminum can be smoothly attached to the corona-free surface of the polypropylene film; meanwhile, vacuum evaporation treatment is adopted, so that gaseous aluminum is deposited on the corona surface of the polypropylene film in a vacuum high-temperature environment, the obtained aluminum metalized layer is thin and uniform, the uniform metal film layer is also a guarantee of good capacitive performance, the capacity of a capacitor using the film is prevented from being different, the sizes of capacitor cores after winding are prevented from being different, and the purpose of evaporating aluminum metalized films on two surfaces of the polypropylene film is finally achieved.

In order to achieve the third object, the invention provides the following technical solutions:

a capacitor core comprises a pair of single-sided metalized polypropylene films arranged side by side, a polypropylene light film arranged between the single-sided metalized polypropylene films and a double-sided aluminum metalized polypropylene film.

Through adopting above-mentioned technical scheme, adopt two-sided aluminium metallized polypropylene film and single face metallized polypropylene film and the cooperation of polypropylene membrane to wind when the condenser core is convoluteed, then three kinds of films all are the polypropylene film material, and the thermal contraction ratio is close, and when condenser core hot pressing, the thermal polymerization effect can obtain promoting. Therefore, the manufactured capacitor has better effect and longer service life, and the capacitor has the effects of being more silent when in use and the like, thereby meeting the market demand.

In conclusion, the beneficial technical effects of the invention are as follows:

1. because the double-sided aluminum metalized polypropylene film adopts the polypropylene base film as a medium and is assisted by the two aluminum metalized layers for conducting and storing charges, and the design of reserving edges in the double sides is adopted, the manufactured capacitor is equivalent to two capacitors which are connected in series, and the voltage resistance of the capacitor is favorably improved;

2. the method adopts the plasma pretreatment and corona treatment modes to treat the non-corona surface of the polypropylene film, and carries out vacuum evaporation on the aluminum metallization layer in a high-vacuum metal deposition mode, thereby solving the problem that a layer of aluminum metal layer is condensed on both the front surface and the back surface of the polypropylene film by evaporation and having the advantage of uniformly evaporating the aluminum metallization layer;

3. according to the capacitor core, each layer is made of the polypropylene film, the thermal shrinkage ratio of each layer is approximate, and the capacitor core has the advantage of improving the thermal polymerization effect.

Drawings

Fig. 1 is a schematic structural view of a double-sided aluminum metallized polypropylene film according to example 1 of the present invention.

Fig. 2 is a flowchart of a method provided in embodiment 2 of the present invention.

Fig. 3 is a schematic structural view of a capacitor core according to embodiment 3 of the present invention.

In the figure, 1, polypropylene base film; 2. an aluminum metallization layer; 3. reserving an edge in the middle; 4. single-sided metallized polypropylene film; 5. a polypropylene light film; 6. double-sided aluminum metallized polypropylene film.

Detailed Description

The present invention will be described in further detail with reference to the following drawings and examples.