JP6220656B2 - Coating equipment - Google Patents

Description

  The present invention relates to a coating apparatus for coating a flame retardant on a battery substrate that is continuously conveyed.

  Conventionally, for example, the coating apparatus of Patent Document 1 includes a coating roll and a coating chamber having a liquid reservoir, and the liquid reservoir accommodates a part of the coating roll. A doctor blade is disposed above the coating roll, and a seal plate is disposed below the coating roll. The doctor blade and the seal plate are opposed to the top and bottom of the coating roll, and the outer periphery of the coating roll. The surface is pressed. Further, side seals are pressed against outer peripheral surfaces on both sides in the roll axis direction of the coating roll, and the liquid reservoir is sealed with the doctor blade, the seal plate, and the both side seals. Then, the coating apparatus is configured to apply the coating liquid measured by scraping off the excessive coating liquid with the doctor blade to the belt-like substrate that is continuously conveyed by the rotation operation of the coating roll. It has become.

  By the way, in the process of manufacturing a lithium ion secondary battery in recent years, for the purpose of preventing ignition when a short circuit occurs, a long positive electrode sheet, a negative electrode sheet, and a long battery sheet constituting the secondary battery using the coating apparatus as described above, and A flame retardant coating solution may be applied to the separator sheet.

JP 2002-177836 A

  However, the flame-retardant coating liquid used for the production of the secondary battery as described above contains a large number of non-conductive, relatively hard particles such as alumina, and the above-mentioned flow depends on the flow of the coating liquid. Friction force applied to each forming surface of the liquid reservoir, inflow hole, and outflow hole by each granular body, and each of the above granular bodies by winding the coating liquid with a coating roll rotating in the liquid reservoir. Due to the impact force applied to the formation surfaces of the liquid reservoir, the inflow hole, and the outflow hole, the formation surfaces of the liquid reservoir, the inflow hole, and the outflow hole are worn and unnecessary materials are mixed into the coating liquid. There is a fear. In particular, if the coating chamber is made of a conductive material, a conductive substance is contained in the coating liquid, and the manufactured secondary battery electrode may be a defective product that is easily short-circuited.

  This invention is made | formed in view of such a point, The place made into the objective is providing the coating apparatus which can prevent that the electrode for lithium ion secondary batteries manufactured becomes a defective article. It is in.

In order to achieve the above object, the technique disclosed in the present specification is characterized in that the hardness of the formation surface of the liquid reservoir in the coating chamber is increased.

  Specifically, a doctor blade and a seal plate are rolled on both sides in the roll radial direction of a coating roll partly immersed in a liquid reservoir of a coating chamber in which a coating liquid containing a large number of non-conductive particles is stored. While facing from both sides in the radial direction and being pressed against the coating roll, a coating device in which the liquid reservoir is sealed by pressing a pair of side seals on both sides in the roll axial direction of the coating roll, The following solutions were taken.

That is, in the first disclosed technique , at least a region facing the liquid reservoir of the coating chamber is formed of wear-resistant ceramics or diamond-like carbon.

In the second disclosed technology , the coating chamber includes a plurality of divided bodies, and a divided portion of each divided body is provided with a contact portion that comes into contact with each other in a combined state. An inflow hole and an outflow hole through which the coating liquid flows in and out of the liquid reservoir at a divided portion other than the contact part in a state where the contact parts of the body are brought into contact with each other and the divided bodies are combined with each other. The formed region facing the inflow hole and the outflow hole of the coating chamber is also formed of wear-resistant ceramics or diamond-like carbon.

In the third disclosed technique , the coating chamber includes a chamber main body made of an aluminum alloy material or a stainless steel material, and an abrasion-resistant ceramic layer coated on the formation surface of the liquid reservoir in the chamber main body. It is characterized by that.

In the fourth disclosed technique, particulate material contained in the coating liquid it is characterized in that it contains the wear resistance ceramic of the abrasion-resistant ceramic layer and the same kind.

In the fifth technique disclosed, the wear-resistant ceramic layer is characterized by an alumina ceramic layer formed by the surface treatment method using plasma electrolytic reaction.

According to a sixth disclosed technique , the alumina ceramic layer includes a dense layer in close contact with the coating chamber and a porous layer in close contact with the surface of the dense layer.

In the seventh disclosed technology , the coating chamber includes a chamber body made of an aluminum alloy material or a stainless steel material, and a diamond-like carbon layer coated on the surface of the chamber body where the liquid reservoir is formed. It is characterized by.

In an eighth disclosed technique, the wear-resistant ceramic layer, characterized in that the hardness is not less than 800 Hv.

In a ninth disclosed technique , the diamond-like carbon layer has a hardness of 800 Hv or more.

In a tenth disclosed technology , the coating chamber is integrally formed of alumina.

In a 11 disclosed technology, a region including at least an outer peripheral surface of the coating roll is formed of ceramics, the doctor blade is characterized in that it is formed of a resin material.

In the first disclosed technology , even if each granular material contained in the flame-retardant coating liquid collides with or rubs against the liquid reservoir forming surface in the coating chamber, the hardness of the liquid reservoir forming surface Therefore, the formation surface of the liquid reservoir is not easily worn. Therefore, it can prevent that the unnecessary thing which generate | occur | produced by abrasion mixes in a flame-retardant coating liquid, and the electrode for secondary batteries turns into a defective product. In addition, even if the wear-resistant ceramic layer or diamond-like carbon layer is peeled off due to wear by each granular material, the ceramic layer and the diamond-like carbon layer are non-conductive, so even when mixed in the coating liquid The secondary battery electrode thus made becomes difficult to become a defective product.

In the second disclosed technique , not only the liquid reservoir formation surface in the coating chamber but also the inflow hole and outflow hole formation surfaces are hard and difficult to wear. Can be further prevented.

In the third or seventh disclosed technique , the processing is performed so that the hardness is increased only in a necessary portion of the coating chamber. Therefore, it is possible to reduce useless processing and suppress the manufacturing cost of the coating chamber.

In the fourth disclosed technology , since the coating liquid includes the same kind of granular material as the wear-resistant ceramic layer coated on the surface where the liquid reservoir is formed, the wear-resistant ceramic layer is peeled off and mixed in the coating liquid. However, the properties of the coating liquid do not change, and the manufactured secondary battery electrode can be prevented from becoming a defective product.

In the fifth disclosed technique , the impact resistance of the region facing the liquid reservoir of the coating chamber is increased, and the wear-resistant ceramic layer is more difficult to peel off during coating.

In the sixth disclosed technique , both the corrosion resistance and the peel resistance can be made high.

In the eighth disclosed technology , since the wear-resistant ceramic layer has high impact resistance to the granular material, the wear-resistant ceramic layer can be prevented from peeling off during coating.

In the ninth disclosed technique , since the diamond-like carbon layer has high wear resistance with respect to the granular material, the diamond-like carbon layer can be prevented from peeling off during coating.

In the tenth disclosed technology , the coating chamber is formed integrally, so that the coating chamber is compared with the case where the chamber body is coated with the wear-resistant ceramic layer after the chamber body is processed as in the third disclosed technology. Production time can be shortened, and the labor required for production can be reduced.

In the eleventh disclosed technology , when the excess coating liquid adhering to the outer peripheral surface of the coating roll is scraped off with the doctor blade, the outer peripheral surface of the coating roll and the tip of the doctor blade are partly removed due to wear. Even if mixed with the liquid, the material of the coating roll and the doctor blade is non-conductive, so that the manufactured secondary battery electrode is unlikely to be a defective product.

The coating apparatus according to implementation embodiments 1 is a schematic view as viewed from the side. It is the A section enlarged view of FIG. Is 1 equivalent diagram of the implementation form 2.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiment is merely exemplary in nature.

"Implementation form 1"
Figure 1 shows a coating apparatus 1 according to the implementation form 1. The coating device 1 is guided by a plurality of guide rolls 11 (only two are shown in FIG. 1) and is conveyed to the battery substrate W conveyed in the upward direction (conveying direction X1 in FIG. 1). The protective layer is formed by applying a coating liquid).

  Although not shown, the battery substrate W has a current collector made of a copper foil having a thickness of about 10 to 20 μm and a thickness of about 50 to 100 μm that is continuously pasted in the substrate transport direction on both sides of the current collector. It consists of an active material layer.

  The flame retardant 10 includes a large number of granular materials 10a made of non-conductive alumina having a hardness of about 2 μm or less and a hardness of about 2000 Hv. 2 is exaggerated for the sake of convenience.

  The coating device 1 includes a ceramic coating roll 2 rotatably supported on a device fixing side (not shown), and a large number of cells (not shown) are formed in the outer peripheral surface of the coating roll 2 as recesses. ing.

  On one side of the coating roll 2 in the roll radial direction, a coating chamber 3 extending in the roll rotation axis direction of the coating roll 2 is provided.

  The coating chamber 3 includes an aluminum alloy chamber main body 3a having a substantially U-shaped cross section that opens to the coating roll 2 side, and an inner portion of the chamber main body 3a stores a liquid reservoir 3b that stores the flame retardant 10. A part of the coating roll 2 is immersed in the liquid reservoir 3b.

  The chamber body 3a includes a first divided body 4 constituting the anti-coating roll 2 side of the coating chamber 3, and a second divided body 5a located on the coating roll 2 side above the first divided body 4. The first divided body 4 is divided into a third divided body 5b located on the coating roll 2 side below the first divided body 4.

  On the coating roll 2 side in the first divided body 4, a bulging portion 4a having a substantially mountain-shaped cross section that bulges toward the coating roll 2 is formed, and the coating roll 2 of the bulging portion 4a is formed. The side surface constitutes a forming surface 40a that forms a shallow recess on the anti-coating roll 2 side and forms the liquid reservoir 3b.

  In addition, an upper through hole 4b and a lower through hole 4c that penetrate in the horizontal direction intersecting the rotational axis direction of the coating roll 2 are formed through the upper and lower portions of the first divided body 4, respectively. .

  The part where the first divided body 4 is divided with the second divided body 5a, that is, the surface above the forming surface 40a on the coating roll 2 side of the first divided body 4 is the upper contact portion 40b. It is composed.

  On the other hand, a portion where the first divided body 4 is divided with the third divided body 5b, that is, a surface below the forming surface 40a on the coating roll 2 side of the first divided body 4 is in a lower side contact. Part 40c is configured.

  The formation surface 40a of the liquid reservoir 3b, the upper contact portion 40b, the lower contact portion 40c, the formation surface 40d of the upper through hole 4b, and the formation surface 40e of the lower through hole 4c are provided with wear resistance. A thickness H1 of the alumina ceramic layer La covered with the ceramic layer and the alumina ceramic layer La, which is the same kind as the alumina granule 10a contained in the flame retardant 10, and is coated on the formation surface 40a of the liquid reservoir 3b. Is substantially the same as the thickness H2 of the alumina ceramic layer La covered with the formation surface 40d of the upper through hole 4b and the formation surface 40e of the lower through hole 4c.

  The second divided body 5a has a substantially rectangular cross section and has a rectangular bar shape extending in the direction of the rotation axis of the coating roll 2, and the divided portion is combined with the first divided body 4 A contact portion 50b that contacts the upper contact portion 40b, and a groove 50c that extends obliquely downward on the coating roll 2 side from a position corresponding to the upper through hole 4b. The upper half portion has a shape that is greatly recessed toward the coating roll 2 side.

  The alumina ceramic layer La is coated on the surface of the second divided body 5a that extends straight up and down on the side opposite to the first divided body 4, the contact portion 50b, and the groove 50c, and the alumina ceramic layer La Is substantially the same as the thickness H2 of the layer La.

  In addition, the third divided body 5b has substantially the same structure as the second divided body 5a except that the third divided body 5b is symmetrically arranged vertically with respect to the second divided body 5a. The same code | symbol as the 2 division body 5a is attached | subjected, and detailed description is abbreviate | omitted.

  In the state where the first divided body 4 and the second divided body 5a are combined by bringing the contact portion 50b of the second divided body 5a into contact with the upper contact portion 40b of the first divided body 4 The upper through-hole 4b and the groove 50c form an outflow hole 3d having a substantially S-shaped cross section through which the flame retardant 10 flows out from the liquid reservoir 3b, while the abutment portion of the third divided body 5b. 50b is brought into contact with the lower contact portion 40c of the first divided body 4 so that the first divided body 4 and the third divided body 5b are combined, and the lower through hole 4c and the recessed groove 50c are combined. Thus, an inflow hole 3c having a substantially S-shaped cross section for allowing the flame retardant 10 to flow into the liquid reservoir 3b is formed.

  The alumina ceramic layer La is formed by a so-called PEO (plasma electrical oxidation) using a plasma electrolytic reaction, and a specific example of the surface treatment method is “KURACERA developed by Kurashiki Boring Kiko Co., Ltd. There is a surface treatment method called.

The alumina ceramic layer La has a hardness of 800 Hv or more, a volume resistivity of 1.0 × 10 ⁻³ (Ω · m) or more, a hardness equal to or higher than that of the hard Cr plating layer, and aluminum. It has a hardness equal to or higher than an anodic oxide film (about 400 Hv) and has a property that it is harder to conduct electricity than a hard Cr plating layer.

  As shown in FIG. 2, the alumina ceramic layer La includes a dense layer La1 that is in close contact with the chamber body 3a and a porous layer La2 that is in close contact with the surface of the dense layer La1. 1 and 2 are exaggerated for the sake of convenience.

  On the side of the second divided body 5a opposite to the first divided body 4, a plate-shaped resin doctor blade 6 is fixed by a fixed block 6a so as to extend straight downward.

  The lower end of the doctor blade 6 is pressed against the outer peripheral surface of the coating roll 2 to seal the downstream side of the liquid reservoir 3b in the roll rotation direction, and the extra flame retardant 10 adhering to the outer peripheral surface is applied to the coating roller 2. The work roll 2 is scraped and measured by the rotating operation.

  On the other hand, on the side of the third divided body 5b opposite to the first divided body 4, a plate-shaped resin seal plate 7 is fixed by a fixed block 7a so as to extend straight upward.

  The seal plate 7 faces the doctor blade 6 and has an upper end pressed against the outer peripheral surface of the coating roll 2 to seal the upstream side in the roll rotation direction of the liquid reservoir 3b.

  Further, a pair of resin side seals 8 is attached to the end of the coating chamber 3 in the roll rotation axis direction, and the liquid reservoir 3b is formed by the doctor blade 6, the seal plate 7 and the side seals 8. It is designed to be sealed.

  Then, the coating apparatus 1 uses the coating roll 2 while circulating the flame retardant 10 accumulated in the liquid reservoir 3b through the inflow hole 3c and the outflow hole 3d by a flame retardant circulation device (not shown). The flame retardant 10 is applied to the battery substrate W by a rotation operation in the transport direction X1 and the reverse direction X2 (see FIG. 1) of the battery substrate W.

In implementation embodiment 1, at the time of coating by the coating apparatus 1, and set the rotation speed of the coating roll 2 to about 50 to 150 m / min, in the liquid reservoir portion 3b of the coating roll 2 rotating operation The speed of the flame retardant 10 to be rotated by is equal to the rotation speed of the coating roll 2. The accompanying speed of the flame retardant 10 is 2 to 5 times the inflow speed of the flame retardant 10 in the inflow hole 3 c, and a large number of granular materials 10 a made of alumina in the flame retardant 10 are applied to the coating chamber 3. It becomes to apply a large impact on the forming surface 40a of the liquid reservoir portion 3b in, according to the implementation mode 1, the said coating chamber 3, and such as described above alumina ceramic layer La is coated, flame retardant 10 Even if each granular material 10a contained therein collides with or rubs against the formation surface 40a of the liquid reservoir 3b in the coating chamber 3, the formation surface 40a of the liquid reservoir 3b has a high hardness. The formation surface 40a of 3b is hard to wear. Therefore, it can prevent that the unnecessary thing generated by abrasion mixes with the flame retardant 10 and the electrode for secondary batteries becomes a defective product. Further, even if the alumina ceramic layer La is peeled off due to wear by the granular materials 10a, the alumina ceramic layer La is non-conductive, so that the produced secondary battery electrode is not mixed even in the coating liquid. It becomes difficult to become a defective product.

  Further, not only the formation surface 40a of the liquid reservoir 3b in the coating chamber 3, but also the formation surfaces 40d and 40e of the inflow hole 3c and the outflow hole 3d become hard and difficult to wear. It is possible to further prevent unwanted materials from peeling off.

  Further, since the processing is performed so that only necessary portions of the coating chamber 3 have high hardness, it is possible to reduce useless processing and reduce the manufacturing cost of the coating chamber 3.

  In addition, since the flame retardant 10 includes the same kind of granular material 10a as the alumina ceramic layer La coated on the formation surface 40a of the liquid reservoir 3b, the alumina ceramic layer La may be peeled off and mixed in the flame retardant 10. The property of the flame retardant 10 does not change, and the manufactured secondary battery electrode can be prevented from becoming a defective product.

  Further, since the alumina ceramic layer La is formed by a surface treatment method using a plasma electrolytic reaction, the impact resistance of the region facing the liquid reservoir 3b of the coating chamber 3 is increased, and the alumina ceramic layer La is coated at the time of coating. The layer La becomes more difficult to peel off.

  Moreover, since the alumina ceramic layer La is formed by laminating the dense layer La1 and the porous layer La2, the coating apparatus 1 having both high corrosion resistance and peeling resistance can be obtained.

  Further, the alumina ceramic layer La has a hardness of 800 Hv or more, and a large impact is applied to the liquid reservoir 3b by the granular material 10a made of alumina of the flame retardant 10 that is rotated by the rotation of the coating roll 2 in the liquid reservoir 3b. Even if it is added to the formation surface 40a, the alumina ceramic layer La has a high impact resistance to the granular material 10a, so that the alumina ceramic layer La can be prevented from peeling off during coating.

  Further, when the doctor blade 6 scrapes off the excess flame retardant 10 adhering to the outer peripheral surface of the coating roll 2, if the outer peripheral surface of the coating roll 2 and a part of the tip of the doctor blade 6 are peeled off due to wear, the flame retardant 10 Even if mixed, the materials of the coating roll 2 and the doctor blade 6 are non-conductive, so that the manufactured secondary battery electrode is unlikely to be defective.

In the implementation form 1, the first split body 4, but by covering the alumina ceramic layer La to the second divided member 5a and the third split body 5b, not limited to this, for example, diamond-like carbon (hereinafter, DLC) layer Lb may be coated. The DLC layer Lb is formed by first applying electroless nickel plating to the first divided body 4, the second divided body 5a, and the third divided body 5b, and then depositing DLC on the upper surface of the electroless nickel by vacuum evaporation. Let it form. Since the DLC layer Lb has a hardness of 800 Hv or more and has high wear resistance with respect to the granular material 10a, even if a large force is applied to the forming surface 40a by each granular material 10a during coating, The DLC layer Lb is difficult to peel off. Therefore, similarly to the alumina ceramic layer La described above, even if each granular material 10a contained in the flame retardant 10 collides with the formation surface 40a of the liquid reservoir 3b in the coating chamber 3, the liquid reservoir is formed by the DLC layer Lb. The formation surface 40a of 3b becomes difficult to wear, and it is possible to prevent the unnecessary material generated by the wear from being mixed in the flame retardant 10 and causing the electrode for the secondary battery to become a defective product.

Also, in the implementation mode 1, to form a chamber body 3a of an aluminum alloy material is not limited thereto and may be formed of stainless steel.

Furthermore, in the implementation mode 1, and covers the alumina ceramic layer La formation surface 40a of the liquid reservoir portion 3b, after coating the alumina ceramic layer La formation surface 40a of the liquid reservoir portion 3b, the alumina ceramic layer An alumina layer may be formed by spraying alumina on the surface of La to further improve the wear resistance and durability of the formation surface 40a of the liquid reservoir 3b.

"Implementation form 2"
Figure 3 shows a coating apparatus 1 according to the implementation form 2. In the second embodiment, only the structure of the coating chamber 3 is different from that of the first embodiment, and the others are the same as those of the first embodiment. Therefore, only the parts different from the first embodiment will be described below.

  The coating chamber 3 of Embodiment 2 is integrally formed with alumina. That is, the region facing the liquid reservoir 3b of the coating chamber 3, the region facing the inflow hole 3c (formation surface 40d), and the region facing the outflow hole 3d (formation surface 40e) are wear resistant. It is made of ceramics.

Therefore, according to the implementation mode 2, since forming the coating chamber 3 with integral coating compared to coat the alumina ceramic layer La in the chamber body 3a after processing the such chamber body 3a of the first embodiment The production time of the chamber 3 is shortened, and the labor involved in production can be reduced.

In the implementation form 1 and 2, has a coating roll 2 and ceramic may be formed of stainless steel or a resin material. Alternatively, a metal coating roll 2 with a ceramic coating or a hard carbon film surface-treated or a resin coating roll 2 with a plating treatment may be used.

Furthermore, in the implementation form 1,2, the sealing plate 7 was used those made of a resin, may be of other materials, for example, it may be used as stainless steel and rubber. Moreover, you may use what gave the ceramic coat | court to the metal. Alternatively, a metal seal plate 7 with a ceramic coating and a hard carbon film surface-treated, or a resin seal plate 7 with a plating treatment may be used.

In addition, in the implementation form 1,2, the doctor blade 6 is was made of resin, may be of other materials, for example, may be used those made of metal and rubber. Alternatively, a metal doctor blade 6 with a ceramic coating and a hard carbon film surface-treated, or a resin doctor blade 6 with a plating treatment may be used.

Then, the coating apparatus 1 of the implementation forms 1 and 2, is performed the coating against cell substrate W comprising a current collector and the active material layer made of copper foil, not limited to this, Coating can also be performed on the battery substrate W to be a resin separator film for a lithium ion secondary battery.

  The present invention is suitable for a coating apparatus for coating a flame retardant on a battery substrate that is continuously conveyed.

DESCRIPTION OF SYMBOLS 1 Coating apparatus 2 Coating roll 3 Coating chamber 3a Chamber main body 3b Liquid reservoir part 3c Inflow hole 3d Outflow hole 4 1st division body 5a 2nd division body 5b 3rd division body 6 Doctor blade 7 Seal plate 8 Side seal 10 Flame retardant 10a Granule 40a Liquid reservoir formation surface 40b Upper contact portion 40c Lower contact portion 40d Inflow hole formation surface 40e Outflow hole formation surface 50b Contact portion 50c Concave groove La Alumina ceramic layer La1 Dense layer La2 porous layer Lb diamond-like carbon layer W battery substrate

Claims (2)

The doctor blade and seal plate are opposed from both sides in the roll radial direction on both sides in the roll radial direction of the coating roll partially immersed in the liquid reservoir of the coating chamber in which the coating liquid containing a large number of non-conductive particles accumulates. In addition to being in pressure contact with the coating roll, a coating device in which the liquid reservoir is sealed by pressing a pair of side seals on both sides in the roll axial direction of the coating roll,
A coating apparatus, wherein the coating chamber is integrally formed of alumina . In the coating device according to claim 1,
The region including at least the outer peripheral surface of the coating roll is formed of ceramics,
The said doctor blade is formed with the resin material, The coating device characterized by the above-mentioned.

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