JP2009262070A - Coating film forming apparatus, coating film forming method, polar plate for cell, and nonaqueous electrolyte secondary cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating film forming apparatus capable of precisely controlling the start end and the finish end of coating in each time with high productivity, when a thin film is formed by intermittently applying a coating material on the surface of a belt like base material laid over a plurality of rolls to feed the material in one direction, and a coating film forming method. <P>SOLUTION: In the coating film forming apparatus, the thin film is formed by bringing the belt-like base material 10 laid over the plurality of the rolls with prescribed tension and fed in one direction into contact with a coating roll 1b intermittently to partially apply the coating material 2 on the base material 10. In such a case, the plurality of the rolls include a driving roll 3 moved to switch the attitude of the base material 10 fed in one direction to a contact attitude in contact with the coating roll 1b and a non-contact attitude in no-contact with the coating roll 1b and a tension roll 5 mechanically joined to the driving roll 3 and moving linked with the driving roll 3 to suppress variation of the tension imparted on the base material 10 when the driving roll 3 is moved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a film forming apparatus, a film forming method, a battery electrode plate, and a non-aqueous electrolyte secondary battery, and more specifically, a heat-resistant protective film on the surface of a substrate such as a battery electrode plate. The present invention relates to a film forming apparatus and a film forming method for forming a thin film, a battery electrode plate manufactured thereby, and a non-aqueous electrolyte secondary battery.

  Lithium ion secondary batteries have a high capacity density for both positive electrode active materials (such as lithium-containing oxides) and negative electrode active materials (such as carbonaceous materials and Si compounds), and are thus being used as power sources for various devices. In recent years, further increases in capacity, output, and size have been demanded, and there is concern over overheating in the case where such a battery is abnormally short-circuited due to an unexpected situation.

  At present, a microporous film mainly made of a resin such as polyolefin is used as a separator for electronically insulating a positive electrode plate and a negative electrode plate. While this microporous film has excellent ability to retain nonaqueous electrolytes, it is easily deformed at high temperatures. Therefore, if an abnormal short circuit occurs inside the battery, overheating will cause defects to grow around the short-circuited part, leading to further overheating. There is a fear.

  Therefore, as in Patent Document 1, by forming a porous heat-resistant layer (protective film) containing magnesium oxide on the surface of the negative electrode plate, even if high heat is generated and the separator melts, the positive electrode plate and the negative electrode plate are A short-circuit prevention technique for preventing direct contact has been proposed.

  An example of a film forming apparatus for forming such a protective film is shown in FIG. 7 (see also Patent Document 2). This film forming apparatus includes an application roll 33 for applying a coating material 32 which is a raw material of the protective film to a long belt-like substrate 34. The application roll 33 is disposed so that the lower part is immersed in the paint 32 held in the container 31 and is rotated in the direction of the arrow 35 </ b> A while the upper part is in contact with the belt-like substrate 34. The base material 34 is wound around a plurality of rolls including an operation roll 36, a tension roll 37, a reference roll 38, and a guide roll 39, is given a certain tension, and is sent in the direction of an arrow 35B. Here, the base material 34 is in contact with the coating roll 33 at the lower surface of the portion spanned between the working roll 36 and the reference roll 38.

Then, when the operation roll 36 moves upward (shown by an imaginary line in the drawing) from the position indicated by the solid line in the drawing, the lower surface of the base material 34 that is in contact with the application roll 33 is separated from the coating roll 33. By moving the working roll 36 between the position indicated by the solid line and the position indicated by the imaginary line at a predetermined timing while feeding the base material 34 in one direction, the paint 32 is intermittently applied to the base material 34. Applied. Here, the tension roll 37 is urged by the urging member 40 so as to suppress the fluctuation of the tension of the base material 34 due to the movement of the operation roll 36, and is provided so as to move while in contact with the base material 34.
JP 2003-142078 A JP 2007-117973 A

As described above, in the conventional film forming apparatus, it is possible to prevent sagging from occurring on the base material by the tension roll biased by the biasing member. For this reason, in the said conventional apparatus, the intermittent application of a coating material needs to be performed at the speed | rate which a tension roll can fully follow. If intermittent coating is performed at a speed that cannot be followed by the tension roll, the base material becomes slack when the operation roll is moved to separate the base material from the coating roll after the completion of each coating. Thereby, the inconvenience that the terminal portion of the coating is not linear but is formed in a wave shape or the like occurs. That is, there is an inconvenience that the start and end of one coating cannot be precisely controlled.
Therefore, in the above conventional example, the feeding speed of the base material, that is, the coating speed is limited to a speed that the tension roll can follow, and this is an obstacle for improving the productivity. .

  The present invention has been made in view of the above-mentioned problems. When a thin film is formed by intermittently applying a coating material to a surface of a belt-shaped substrate that is stretched over a plurality of rolls and fed in one direction. An object of the present invention is to provide a film forming apparatus and a film forming method that are highly productive and that can precisely control the start and end of each coating. Another object of the present invention is to provide a battery electrode plate having a protective film formed by such a film forming apparatus and a nonaqueous electrolyte secondary battery including the same.

In order to achieve the above object, the film forming apparatus of the present invention intermittently contacts a coating tool for holding a paint while feeding a strip-shaped substrate over a plurality of rolls with a predetermined tension in one direction. And a coating film forming apparatus for intermittently applying the paint to the base material to form a thin film,
The plurality of rolls are
An operation roll that is moved so as to switch the posture of the substrate sent in the one direction between a contact posture in which the substrate is in contact with the coating tool and a non-contact posture in which the substrate is not in contact with the coating tool;
A tension roll that is mechanically connected to the actuation roll and moves in conjunction with the actuation roll so that the tension of the substrate does not fluctuate when the actuation roll moves.

Here, the base material contacts the coating tool on one side,
Each of the working roll and the tension roll is pivotally supported by a connecting member that rotates about an axis that is equidistant from each axis,
It is preferable that the connecting member is rotated within a range in which the operation roll and the tension roll are always in contact with the other surface of the substrate.

Further, the base material is in contact with the coating tool on one side,
Each of the working roll and the tension roll is pivotally supported by a link mechanism that moves the rolls by the same distance in opposite directions along straight lines parallel to each other, and the other surface of the substrate is always It is also preferable that the moving mechanism is moved by the link mechanism within a contact range.

In addition, the plurality of rolls are
A fixed reference roll that is provided immediately before the working roll in the direction of feeding the base material and switches the posture of the base material between the contact posture and the non-contact posture in cooperation with the working roll. When,
A guide roll that is provided immediately after the tension roll in the feeding direction of the base material and guides the base material that has passed through the tension roll;
The reference roll and the guide roll are preferably provided with respective axes at symmetrical positions with respect to a plane where the distances between the working roll and the tension roll are always equal.

The substrate has a base layer formed corresponding to the coating area of the paint,
Driving means for driving the connecting member or the link mechanism to move the operating roll and the tension roll to switch the posture of the base material between the contact posture and the non-contact posture;
An underlayer detection means for detecting an underlayer on the substrate;
It is also preferable to include a control unit that controls the driving unit based on the detection result of the base layer detection unit.

The base material is formed by forming an electrode mixture layer containing an electrode active material as a base layer on a metal foil,
The thin film is a porous protective film covering the electrode mixture layer,
The protective film covers the entire surface of the electrode mixture layer and covers a predetermined region adjacent to the electrode mixture layer in the exposed metal foil surface on which the electrode mixture layer is not formed. preferable.

The end of the thin film in the direction in which the base material is sent has a linear shape extending perpendicular to the direction in which the thin film is sent,
It is also preferable that the film thickness of the end of the thin film is larger than the film thickness of the other part.

In order to achieve the above object, the film forming method according to the present invention includes a belt-like base material that is stretched over a plurality of rolls including a working roll and a tension roll in a predetermined direction with a predetermined tension. A film forming method of intermittently contacting with a holding coating tool to form a thin film by intermittently applying the paint to the base material,
The actuating roll is moved so as to switch the posture of the substrate sent in the one direction between a contact posture in which the substrate is in contact with the coating tool and a non-contact posture in which the substrate is not in contact with the coating tool,
The tension roll is mechanically connected to the working roll and moves in conjunction with the working roll so that the tension of the base material does not fluctuate due to the movement of the working roll.

  In order to achieve the above object, the battery electrode plate of the present invention has a protective film formed by the film forming apparatus.

  In order to achieve the above object, the nonaqueous electrolyte secondary battery of the present invention includes a battery electrode plate on which a protective film is formed by the film forming apparatus.

According to the present invention, the tension roll is mechanically connected to the working roll and moves in conjunction with the working roll so that the tension of the substrate does not fluctuate when the working roll moves. Even if it is sent at a speed higher than that in the conventional apparatus, it is possible to prevent the base material from being slack due to the movement of the working roll. Therefore, productivity can be improved.
In addition, since no slack occurs in the base material, it is possible to more precisely control the start and end of each time of intermittent coating.

<Embodiment 1>
Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view of a film forming apparatus according to an embodiment of the present invention.

  The coated film forming apparatus of FIG. 1 can be used for producing at least one of a sheet-like electrode plate constituting a positive electrode and a negative electrode of a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. In this film forming apparatus, the protective film 11 is formed on the base material 10 so as to form, for example, a porous protective film 11 having heat resistance (see FIG. 2) on the surface of the long band-shaped base material 10 fed in one direction. The coating part 1 which applies the coating material 2 of the predetermined composition which is the raw material of this is provided.

Moreover, the film forming apparatus includes a plurality of rolls on which the base material 10 fed in one direction is stretched with a predetermined tension. The plurality of rolls include at least a reference roll 4, an operation roll 3, a tension roll 5, and a guide roll 6 shown in the drawing.
The film forming apparatus includes a sensor 21 and a control unit 22 which will be described in detail later, a coating roll drive motor, a take-up roll drive motor, a take-up roll drive motor, a connection member drive motor, and the like (not shown).

As shown in FIG. 2, the base material 10 is formed by applying a metal substrate 10a made of a metal foil such as a copper foil or an aluminum foil and an electrode mixture mainly composed of an electrode active material on the surface thereof. And an electrode plate mixture layer 10b as a base layer.
Here, as shown in FIG. 3, in the base material 10, the electrode plate mixture layer 10b is not formed over the entire length of the metal substrate 10a, but has a predetermined length in which the metal substrate 10a is exposed. An electrode plate mixture layer 10b having a certain length is formed on one or both sides of the metal substrate 10a in an intermittent manner with the exposed portion 10c interposed therebetween.

  The coating unit 1 includes a container 1a in which a paint 2 made of a slurry in which a filler made of an inorganic oxide is dispersed in a liquid component such as N-methyl-2-pyrrolidone (NMP) together with a small amount of a binder, and a paint 2 The coating roll 1b as a coating tool for contacting the base material 10 while applying the coating material 2 to the base material 10 in a state where is held on the peripheral surface.

  The coating roll 1b is arranged so that a part, for example, only the lower part of the coating roll 1b is immersed in the paint 2 in the container 1a. The coating material 2 adheres to the peripheral surface of the coating roll 1 b immersed in the coating material 2. The coating roll 1b is rotationally driven by a coating roll drive motor (not shown), and the portion to which the coating material 2 adheres intermittently contacts one surface of the substrate 10 at a position corresponding to the electrode plate mixture layer 10b. Thereby, the coating material 2 is intermittently applied to one surface of the substrate 10.

  Here, the long belt-like base material 10 is wound around the operation roll 3, the reference roll 4, the tension roll 5, and the guide roll 6 with a predetermined tension, and is sent in the direction indicated by the arrow 7B. The operation roll 3, the reference roll 4, the tension roll 5, and the guide roll 6 are rolls provided so as to freely rotate, and are always in contact with the surface of the substrate 10 opposite to the surface to which the paint 2 is applied. Is arranged. Moreover, after the base material 10 is unwound from the unwinding roll rotated by the unillustrated unwinding roll drive motor, and passes the reference | standard roll 4, the action | operation roll 3, the tension roll 5, and the guide roll 6 in this order Winding is performed by a winding roll that is rotationally driven by a winding roll drive motor (not shown). Then, the base material 10 has the one surface (the lower surface in the figure) in contact with the coating roll 1b at the intermediate position of the portion spanned between the reference roll 4 and the working roll 3, and the coating 2 is on that surface. To be applied.

  Here, each of the operation roll 3 and the tension roll 5 is pivotally supported by a connection member 8 that is rotated within a predetermined range about an axis I3 that is equidistant from the axes I1 and I2. The connecting member 8 is made of steel or the like so as to have sufficient rigidity, and the axes I1 and I2 of the actuating roll 3 and the tension roll 5 move completely in conjunction with the rotation of the connecting member 8.

  The working roll 3 switches the posture of the base material 10 in a portion spanned between the reference roll 4 that is a fixed roll to a contact posture in which the base material 10 is in contact with the coating roll 1b and a non-contact posture in which it is not in contact. Thus, it is moved by the rotation of the connecting member 8. At this time, the tension roll 5 simultaneously moves upward by the same distance if the working roll 3 moves downward, and simultaneously moves downward by the same distance if the working roll 3 moves upward. As described above, the movement of the tension roll 5 is completely interlocked with the movement of the working roll 3.

  Here, the guide roll 6 and the reference roll 4 have the same diameter, and the respective axes I4 and I5 are in a plane 9 where the distances from the respective axes I1 and I2 of the working roll 3 and the tension roll 5 are always equal. They are provided so as to be symmetrical with respect to each other. Thus, the guide roll 6 positioned immediately after the tension roll 5 and the reference roll 4 positioned immediately before the working roll 3 in the direction of feeding the base material 10 are provided so as to be targets with respect to the plane. Therefore, the length of the base material 10 in the portion spanned from the reference roll 4 to the guide roll 6 through the working roll 3 and the tension roll 5 is determined by the rotation of the connecting member 8. Does not change even if moves.

  Therefore, even if the connecting member 8 is rotated so that the posture of the base material 10 is switched between the contact posture and the non-contact posture, the tension of the base material 10 does not change in principle, and the base material 10 There is no slack. Thereby, even if intermittent coating is performed at a high speed, it is possible to prevent the base material 10 from becoming slack at the start and end of each application of intermittent coating. Accordingly, it is possible to avoid inconveniences such as the start and end of each coating, in particular, the end does not become linear but wave. That is, the start or end of each coating can be precisely controlled. Therefore, it is possible to perform intermittent coating while feeding the base material 10 at a remarkably high speed compared to the case where the tension roll is urged by the urging member to suppress the fluctuation of the tension of the base material 10. Become. Thereby, productivity can be improved dramatically.

  Here, the distance between the axes of the reference roll 4 and the working roll 3 is preferably 1.2 times to 2.5 times the diameter of the coating roll 1b. As described above, by placing the reference roll 4 and the working roll 3 close to each other, the tension state of the base material 10 between the reference roll 4 and the working roll 3 is excellent only by applying a small tension to the base material 10. Can be. As a result, it is possible to prevent the tension applied to the base material 10 from being too large and the thin base material 10 from being cut or from being stretched, wrinkled or pulled. .

  The reason why the distance between the axes of the reference roll 4 and the working roll 3 is 1.2 times or more the diameter of the coating roll is to allow the working roll 3 to move smoothly. For this reason, it is preferable that the reference roll 4 and the working roll 3 are rolls having a relatively small diameter, and it is particularly preferable to have the same diameter as that of a coating roll 1b described later.

  The application roll 1b may be configured as a so-called gravure roll having a concave surface (gravure pattern) engraved on the peripheral surface. In this case, it is preferable to press a doctor blade (not shown) against the peripheral surface of the coating roll 1b with a constant pressure to scrape off the excess paint 2 in order to make the coating amount uniform. The doctor blade is more preferably made of resin in order to suppress wear of the coating roll 1b.

  FIG. 4 is an example of a gravure pattern when the coating roll 1b is configured as a gravure roll. In this coating roll 1b, a large number of paint reservoir grooves 12 that are gravure patterns are parallel to each other with a flat portion 13 therebetween, and a predetermined angle θ (for example, θ = 45 °) with respect to the radial direction of the coating roll 1b. It is inclined and engraved at an equal pitch on the entire peripheral surface.

  Here, as shown by an arrow 7 </ b> A in FIG. 1, the coating roll 1 b is preferably rotationally driven so that the contact portion with the base material 10 moves in the direction opposite to the feeding direction of the base material 10. As a result, slippage in the direction opposite to the rotation direction of the coating roll 1b occurs on the contact surface of the coating roll 1b with the base material 10. At this time, a small paint pool is formed on the rear side of the contact point between the coating roll 1b and the substrate 10 in the feeding direction of the substrate 10. The paint in the paint reservoir is guided by the rotation of the coating roll 1b and uniformly stretched. This prevents the trace of the paint reservoir groove 12 from sticking to the surface of the protective film 11. Therefore, it is possible to form the protective film 11 having a precise smooth surface.

  Further, according to the gravure pattern, the paint 2 transferred from the paint reservoir groove 12 to the base material 10 is thinly and evenly stretched by the flat surface portion 13. Therefore, the protective film 11 having a uniform and very thin film thickness, for example, 20 μm or less can be formed on the surface of the substrate 10.

  Further, as the coating roll 1b, a relatively small roll having a diameter of 40 to 60 mm is used, and the contact area between the coating roll 1b and the substrate 10 is extremely small. In addition, it is preferable to apply accurately so as to be uniform. Moreover, by using such a roll, the stability at the time of contact / separation with the application | coating roll 1b of the base material 10 improves, and the position of the application start and application stop of a coating material can be set correctly. The reason why the diameter of the coating roll 1b is 40 mm or more is to obtain good rigidity and processing accuracy.

  Further, when a battery electrode plate is manufactured, a current collector made of copper foil or aluminum foil having a thickness of about 10 μm is used as the metal substrate 10 a of the base material 10. In order to apply the coating material 2 to the base material 10 using such a thin metal substrate 10a so that the application amount is uniform, the base material 10 is stretched at least at a portion in contact with the application roll 1b. It is necessary to feed the base material 10 under a certain tension so as not to cause wrinkles or pulling. This is because it is possible to prevent the occurrence of coating unevenness in which the coating amount of the paint 2 is not uniform.

  In this regard, when the base material 10 is fed in the direction opposite to the rotation direction of the coating roll 1b, the frictional force between the base material 10 and the coating roll 1b is increased, and the thin base material 10 is thin. Elongation, wrinkle or pulling is likely to occur. Therefore, using a roll with a relatively small diameter of 40 to 60 mm, the contact area between the base material 10 and the coating roll 1b is reduced, whereby the frictional force generated between the base material 10 and the coating roll 1b. There is an increasing need to suppress this.

Hereinafter, the control unit 22 will be described.
The control unit 22 is composed of, for example, a microcomputer, and controls at least the connection member drive motor. The connecting member drive motor is composed of a servo motor, and is controlled by the control unit 22 so that the operation roll 3 has a coating execution position where the base material 10 assumes a contact posture shown by a solid line in FIG. The connecting member 8 is driven so as to move at a predetermined timing between the coating non-execution position in the non-contact posture shown by the imaginary line in FIG.

  At this time, as shown in FIG. 5, for example, the sensor 21 made of a reflective photoelectric sensor detects the start end P <b> 1 and the end end P <b> 2 of each electrode mixture layer 10 b on the substrate 10 sent in one direction. The control unit 22 calculates the formation pitch of the electrode mixture layer 10b based on the detection result of the sensor 21, and based on the formation pitch, the control unit 22 moves the paint 2 from the position before the start end P1 of the electrode mixture layer 10b to the end P2. The connecting member drive motor is controlled so as to apply to the rear position. Thereby, the porous protective film 11 which coat | covers the whole each electrode mixture layer 10b is formed, and the battery electrode plate is completed. The protective film 11 should have a very thin film thickness of about 6 μm after the paint 2 is dried. Even with such a thin protective film 11, the film forming apparatus having the above-described configuration is used. As a result, the protective film 11 can be formed so that the start end P1 and the end end P2 are not wavy, but have a straight line shape.

  Here, the control unit 22 includes a central processing unit (CPU) and a memory, and the memory rotates the connection member 8 according to the type of the base material 10 and the type of the paint 2. Data such as range and rotation speed are stored in advance. The central processing unit of the control unit 22 controls the connecting member driving motor so as to rotate the connecting member 8 by a predetermined angle at a predetermined timing while referring to the data read from the memory.

  By the way, in the intermittent coating described above, the end P3 of the protective film 11 has a raised shape so that the film thickness is slightly larger than other portions. The reason why the end P3 has such a shape is that, as described above, a small paint pool is formed on the rear side of the contact point between the coating roll 1b and the substrate 10 in the feeding direction of the substrate 10. This paint reservoir is usually stretched by the coating roll 1b and disappears, but is left without being stretched when the coating roll 1b is separated from the substrate 10 after each coating. That is the cause of the end P3 having the shape described above.

  Here, in the present embodiment, the end P3 of the protective film 11 is set to be behind the end P2 of the electrode mixture layer 10b that is the base layer, and the end P3 of the protective film 11 is the metal substrate. Formed directly on 10a. Therefore, even if the thickness at the end P3 of the protective film 11 is larger than the thickness of the other part, the part does not become higher than the other part. As a result, even when the electrode plate is wound in a spiral shape or folded and laminated to form an electrode group, there is no portion where the thickness of the electrode plate is partially increased. Can be constructed more precisely.

  The control unit 22 may be configured to control the connecting roll drive motor and the application roll drive motor, or to control the take-up roll drive motor and the unwind roll drive motor. It may be configured.

  Here, the film thickness of the thin film (protective film 11) can be adjusted by changing the rotation speed of the coating roll 1b and the depth of the paint reservoir groove 12. At this time, as the rotation speed of the coating roll 1b is increased, the supply amount of the paint 2 is increased, and the film thickness of the thin film is increased. Similarly, as the depth of the paint reservoir groove 12 is increased, the supply amount of the paint paint 2 is increased and the film thickness of the thin film is increased. At this time, the ratio of the peripheral speed of the coating roll 1b to the feed speed of the base material 10 is preferably 200 to 500%. When the ratio is smaller than 200%, the gravure pattern on the peripheral surface of the coating roll 1b appears on the surface of the formed film and the film thickness becomes non-uniform. On the other hand, when the ratio is larger than 500%, the centrifugal rotation is performed. This is because inconveniences such as scattering of the paint 2 by force occur. By setting the ratio within the above range, a thin film with a uniform thickness can be formed with high accuracy even with a very thin film thickness.

  In addition, the use of an inorganic oxide as a filler to be included in the paint 2 requires heat resistance for use in a battery electrode plate, and in addition, for example, within the range of use of a lithium ion secondary battery. This is because it is necessary to be stable. Furthermore, the inorganic oxide is most preferably alumina from the viewpoint of electrochemical stability, and it is most preferable to use the coating material 2 in which a small amount of a binder is added to the alumina particles of about 1.2 μm and kneaded.

  Further, in the case of the positive electrode, the electrode mixture layer 10b uses, as an active material, a composite oxide such as lithium cobaltate and a modified product thereof (such as a solution in which aluminum or magnesium is dissolved). A mixture slurry obtained by mixing a binder and a conductive agent and kneading to obtain an optimum viscosity is applied to the metal substrate 10a. In the case of the negative electrode, for example, various active graphites, artificial graphite, and silicon-based composite materials such as silicides are used as active materials, and this active material is mixed with a binder and a conductive agent and kneaded to obtain an optimum viscosity. An agent slurry is formed on the metal substrate 10a.

<Embodiment 2>
Next, referring to FIG. 6, a film forming apparatus according to Embodiment 2 of the present invention will be described. FIG. 6 is a schematic view of a main part of the film forming apparatus of the second embodiment.
As shown in FIG. 6, in the film forming apparatus of the second embodiment, the working roll 3 and the tension roll 5 are mechanically connected by a link mechanism 14. Here, the link mechanism 14 is a mechanism for moving the working roll 3 and the tension roll 5 by the same distance in the opposite direction along the straight lines 9A and 9B parallel to the plane 9 of the first embodiment. is there. Other configurations of the second embodiment are the same as those of the first embodiment.

  Such a link mechanism 14 includes a pinion 14a disposed in the center of the operation roll 3 and the tension roll 5, and two racks provided so as to mesh with the pinion 14a and move in parallel with the straight lines 9A and 9B. 14b, 14c and two support members 14d, 14e connected to the racks 14b, 14c and supporting the shafts of the respective rolls. Here, the pinion 14a is rotationally driven in forward and reverse directions by a pinion drive motor (not shown) so that the control unit 22 performs intermittent coating on the substrate 10 in the same manner as in the first embodiment. Controls the pinion drive motor.

  Also in the film forming apparatus of the second embodiment, the operation roll 3 switches the posture of the base material 10 between a contact posture in which the base material 10 is in contact with the coating roll 1b and a non-contact posture in which the base material 10 is not in contact with the coating roll 1b. Even if it moves, the tension roll 5 moves so as to be completely interlocked with the working roll 3 so that the tension of the base material 10 does not fluctuate due to the movement, so that the same effect as in the first embodiment can be obtained. .

  The film forming apparatus of the present invention forms a thin film with a very thin film thickness of, for example, 20 μm or less intermittently with high productivity, while forming a highly accurate shape with excellent linearity at the coating end. In particular, it can be suitably applied to the step of forming the active material layer of the battery electrode plate and the porous protective film thereof.

It is the schematic of the film formation apparatus which concerns on Embodiment 1 of this invention. It is sectional drawing of the state in which the protective film was formed in the base material by the film forming apparatus of FIG. It is a perspective view of the base material of the battery electrode plate in which a protective film is formed with the film formation apparatus of FIG. It is a top view of the application roll in which the gravure pattern was formed. It is a perspective view which shows the process which forms a protective film in a base material with the film formation apparatus of FIG. It is the schematic of the principal part of the film forming apparatus which concerns on Embodiment 2 of this invention. It is the schematic of the conventional film formation apparatus.

Explanation of symbols

1 coating part 1b coating roll (coating tool)
2 paint 3 working roll 4 reference roll 5 tension roll 6 guide roll 8 connecting member 9 plane 10 base material 11 protective film (thin film)
14 Link mechanism 21 Sensor 22 Control unit

Claims (10)

A thin film is formed by intermittently contacting a belt-like substrate with a coating tool for holding a coating material while intermittently contacting the coating material while holding the coating material on a plurality of rolls with a predetermined tension. A film forming apparatus for forming
The plurality of rolls are
An operation roll that is moved so as to switch the posture of the substrate sent in the one direction between a contact posture in which the substrate is in contact with the coating tool and a non-contact posture in which the substrate is not in contact with the coating tool;
A tension roll that is mechanically connected to the actuation roll and moves in conjunction with the actuation roll so that the tension of the substrate does not fluctuate when the actuation roll moves.
Film forming device. The substrate is in contact with the coating tool on one side;
Each of the working roll and the tension roll is pivotally supported by a connecting member that rotates about an axis that is equidistant from each axis,
The film forming apparatus according to claim 1, wherein the connection member rotates in a range in which the operation roll and the tension roll always contact the other surface of the base material. The substrate is in contact with the coating tool on one side;
Each of the working roll and the tension roll is pivotally supported by a link mechanism that moves the rolls by the same distance in opposite directions along straight lines parallel to each other, and the other surface of the substrate is always The film forming apparatus according to claim 1, wherein the film forming apparatus is moved by the link mechanism within a range of contact. The plurality of rolls are
A fixed reference roll that is provided immediately before the working roll in the direction of feeding the base material and switches the posture of the base material between the contact posture and the non-contact posture in cooperation with the working roll. When,
A guide roll that is provided immediately after the tension roll in the feeding direction of the base material and guides the base material that has passed through the tension roll;
4. The film forming apparatus according to claim 2, wherein the reference roll and the guide roll are provided with respective axes at symmetrical positions with respect to a plane in which distances between the working roll and the tension roll are always equal. The substrate has a base layer formed corresponding to the coating area of the paint,
Driving means for driving the connecting member or the link mechanism to move the operating roll and the tension roll to switch the posture of the base material between the contact posture and the non-contact posture;
An underlayer detection means for detecting an underlayer on the substrate;
The film forming apparatus according to claim 2, further comprising a control unit that controls the driving unit based on a detection result of the base layer detection unit. The base material is formed by forming an electrode mixture layer containing an electrode active material as a base layer on a metal foil,
The thin film is a porous protective film covering the electrode mixture layer,
The said protective film covers the whole area | region of the said electrode mixture layer, and covers the predetermined area | region adjacent to the said electrode mixture layer among the surfaces of the exposed metal foil in which the said electrode mixture layer is not formed. 5. The film forming apparatus according to 5. The end of the thin film in the direction in which the base material is sent has a linear shape extending perpendicular to the direction in which the thin film is sent,
The film forming apparatus according to claim 6, wherein the film thickness of the end of the thin film is larger than the film thickness of the other part. The belt-like base material is intermittently brought into contact with a coating tool for holding a paint while being fed in one direction over a plurality of rolls including an operation roll and a tension roll with a predetermined tension, and the paint is applied to the base material. A film forming method in which a thin film is formed by intermittently applying
The actuating roll is moved so as to switch the posture of the substrate sent in the one direction between a contact posture in which the substrate is in contact with the coating tool and a non-contact posture in which the substrate is not in contact with the coating tool,
A method of forming a film, wherein the tension roll is mechanically connected to the working roll and moves in conjunction with the working roll so that the tension of the base material does not fluctuate due to the movement of the working roll.   A battery electrode plate on which a protective film is formed by the film forming apparatus according to claim 6.   A nonaqueous electrolyte secondary battery comprising a battery electrode plate on which a protective film is formed by the film forming apparatus according to claim 6.

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