Squeegee and powder coating apparatus

Abstract

This squeegee is to be relatively-moved in a certain direction while a desired gap is being formed with respect to a base material so as to obtain a uniform thickness for a powder layer composed of a powder body supplied on the base material, and is provided with: a first portion which vibrates in contact with the powder on the upstream side of the relative movement direction of the base material with respect to the squeegee; and a second portion which vibrates in contact with the powder on the downstream side of the relative movement direction of the base material with respect to the squeegee. The vibration direction of the first portion is different from the vibration direction of the second portion.

Description

Technical Field

[0001] The present disclosure relates to a squeegee and a powder coating apparatus.

Background Art

[0002] Conventionally, a technique of coating a powder on the surface of a member while transporting the member such as a metal foil has been widely known.

[0003] For example, Patent Document 1 discloses a technique of coating a composite material (powder) containing an active material on the surface of a current collector that is a long metal foil.

[0004] Also, Patent Document 2 discloses a method of applying vibrations of about 700 Hz to a cylindrical squeegee in order to suppress the retention of powder.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

[0006] A squeegee according to one aspect of the present disclosure is a squeegee that levels the thickness of a powder layer composed of powder supplied onto a base material by relatively moving in a certain direction while forming a desired gap with respect to the base material, and a first portion that vibrates in contact with the powder on the upstream side of the relative movement direction of the base material with respect to the squeegee, and a second portion that vibrates in contact with the powder on the downstream side of the relative movement direction of the base material with respect to the squeegee, and the vibration direction of the first portion is different from the vibration direction of the second portion.

Brief Description of the Drawings

[0007]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 2C

Figure 3

Figure 4A

Figure 4B

Figure 4C

Figure 5

Figure 6A

Figure 6B

Figure 6C

Figure 6D

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13A

Figure 13B

Figure 13C

Figure 14A

Figure 14B

Figure 15

Figure 16

Embodiments for Carrying Out the Invention

[0008] The problems of Patent Document 1 will be described with reference to FIGS. 9 and 10. FIG. 9 is a schematic diagram of a prior art using the blade-shaped squeegee 100 described in Patent Document 1. Further, FIG. 10 is a vector diagram showing the force applied to the powder 4 when the powder 4 comes into contact with the blade-shaped squeegee 100.

[0009] As shown in FIG. 9, Patent Document 1 describes that after supplying the powder 4 onto the surface of the metal foil as the base material 3, the thickness of the powder layer is uniformly adjusted by leveling the powder 4 with the blade-shaped squeegee 100.

[0010] However, as shown in FIG. 10, when the powder 4 contacts the surface 101 of the squeegee 100, the powder 4 receives a force 103 in the direction opposite to the moving direction 7 of the powder 4 (the relative moving direction of the base material 3 (metal foil) with respect to the squeegee 100) as a resistance force against the force 102 that vertically presses the contact surface of the squeegee 100 (the surface 101 of the squeegee). Therefore, when the fluidity of the powder 4 is low, the powder 4 tends to stay on the upstream side in the relative moving direction 7 of the base material 3 (metal foil) with respect to the squeegee 100. For this reason, a bridge is likely to occur between the squeegee 100 and the base material 3 (metal foil).

[0011] To suppress the retention of the powder 4 and the generation of a bridge, it is important to reduce the force 103 in the direction opposite to the moving direction of the powder (the relative moving direction 7 of the base material 3 (metal foil) with respect to the squeegee 100), which the powder 4 receives from the squeegee 100 as a resistance force against the force 102 that vertically presses the contact surface of the squeegee 100 (the surface 101 of the squeegee).

[0012] The problems of Patent Document 2 will be described with reference to FIGS. 11, 12, and 13A to 13C.

[0013] FIG. 11 shows a schematic diagram of a prior art for vibrating a columnar squeegee 150 described in Patent Document 2. FIG. 12 is a vector diagram showing the force applied to the powder 4 when the powder 4 comes into contact with the non-vibrating columnar squeegee 150. FIGS. 13A to 13C are vector diagrams showing the force applied to the powder 4 when the powder 4 comes into contact with the columnar squeegee 150 vibrated in the vibration direction A while maintaining the shortest distance 109 between the columnar squeegee 150 vibrated in the vibration direction A and the base material 3 in FIG. 11. Here, FIG. 13A is a vector diagram showing the force 111 with which the powder 4 pushes the squeegee 150 (the resultant force of the force 104 due to the conveyance of the base material and the force 110 applied to the powder 4 from the vibrating squeegee 150) when the squeegee 150 moves in the direction opposite to the relative movement direction 7 of the base material 3 with respect to the squeegee 150 as the movement of the squeegee 150 to one side in the vibration. FIG. 13B is a vector diagram showing the force 105 that vertically pushes the squeegee 150, which is a part of the force obtained by decomposing the force 111 with which the powder 4 pushes the squeegee 150 in FIG. 13A, and the force 107 that the powder 4 receives from the squeegee 150 as the resistance of the force. FIG. 13C is a vector diagram showing the state when the columnar squeegee 150 moves in the same direction as the relative movement direction 7 of the base material 3 with respect to the squeegee 150 as the movement of the squeegee 150 to the other side in the vibration.

[0014] In the case of the columnar squeegee 150 described in Patent Document 2 as shown in FIG. 11, unlike the case of the blade-shaped squeegee 100 described in Patent Document 1 shown in FIG. 9, as shown in FIG. 12, the force 104 by which the powder 4 pushes the squeegee 150 when conveyed to the base material 3 is decomposed into a force 105 that vertically presses the contact surface (squeegee surface 151) of the squeegee 150 and a force 106 that slides on the contact surface (squeegee surface 151) of the squeegee. The powder 4 receives a force 107 directed radially outward of the cylinder (squeegee 150) as a resistance force against the force 105 that vertically presses the contact surface (squeegee surface 151) of this squeegee 150. However, since the force 107 directed radially outward of this cylinder (squeegee 150) includes a component 108 in the direction opposite to the relative movement direction 7 of the base material 3, when the fluidity of the powder 4 is low, the powder 4 tends to stay on the upstream side in the relative movement direction 7 of the base material 3 with respect to the columnar squeegee 150. For this reason, it becomes a factor for a bridge to occur between the columnar squeegee 150 and the base material 3 (metal foil).

[0015] In the columnar squeegee 150, in order to suppress the retention of the powder 4 and the generation of a bridge, as a resistance force against the force 105 by which this powder 4 vertically presses the contact surface (squeegee surface 151) of the squeegee 150, it is important to reduce the force 107 received from the squeegee 150 directed radially outward of the squeegee 150 which is a cylinder, that is, to reduce the component of the force in the direction opposite to the direction in which the powder 4 moves (the relative movement direction 7 of the base material 3).

[0016] Also, in order to suppress the retention of the powder 4 and the generation of a bridge, it is also effective to increase the force 106 that slides on the contact surface (squeegee surface 151) of the squeegee 150, which is the decomposition of the force 104 by which the powder 4 pushes the squeegee 150 when conveyed to the base material 3. This is because by increasing the force 106, the entry of the powder 4 into the gap between the squeegee 150 and the base material 3 can be promoted.

[0017] Next, the case where the cylindrical squeegee 150 described in Patent Document 2 shown in FIG. 11 is vibrated along the vibration direction A in FIG. 11 including the relative movement direction 7 of the substrate 3 with respect to the squeegee 150 and the reverse direction thereof while maintaining the shortest distance 109 between the squeegee 150 and the substrate 3 will be similarly described.

[0018] First, when the squeegee 150 vibrates in the reverse direction of the relative movement direction 7 of the substrate 3, as shown in FIG. 13A, as the powder 4 is conveyed to the substrate 3, the resultant force of the force 104 that the powder 4 pushes the squeegee 150 and the force 110 applied from the vibrating squeegee 150 to the powder 4 becomes the force 111 that the powder 4 pushes the squeegee. This force 111 that the powder 4 pushes the squeegee 150 can be decomposed into a force 105 that vertically presses the contact surface (squeegee surface 151) of the squeegee 150 and a force 106 that slides on the contact surface (squeegee surface 151), as shown in FIG. 13B. This powder 4 receives a force 107 directed radially outward of the cylinder as a resistance force against the force 105 that vertically presses the contact surface (squeegee surface 151) of the squeegee 150. Here, although the force 107 is smaller than the case where the squeegee 150 shown in FIG. 12 does not vibrate, since it includes a component 108 in the direction opposite to the relative movement direction 7 of the substrate 3, when the fluidity of the powder 4 is low, the powder 4 stays on the upstream side in the relative movement direction 7 of the substrate 3. For this reason, it becomes a factor for a bridge to occur between the cylindrical squeegee 150 and the substrate 3 (metal foil). Also, compared to the case where the squeegee 150 shown in FIG. 12 does not vibrate, the force 106 that slides on the contact surface (squeegee surface 151) of the squeegee becomes smaller, so that the powder 4 cannot be promoted to enter the gap between the squeegee 150 and the substrate 3. Also, when the fluidity of the powder 4 is low, the powder 4 stays on the upstream side in the relative movement direction 7 of the substrate 3. For this reason, it becomes a factor for a bridge to occur between the cylindrical squeegee 150 and the substrate 3 (metal foil).

[0019] Also, when the cylindrical squeegee 150 vibrates in the same direction as the relative movement direction 7 of the substrate 3, as shown in FIG. 13C, since the movement is in the direction in which the squeegee 150 moves away from the powder 4, the squeegee 150 has no effect of suppressing the retention and the occurrence of a bridge with respect to the powder 4.

[0020] Thus, when the cylindrical squeegee 150 described in Patent Document 2 is vibrated in the relative movement direction 7 of the base material 3 and the reverse direction thereof (vibration direction A in FIG. 11) while maintaining the shortest distance 109 between the squeegee 150 and the base material 3, the states shown in FIGS. 13B and 13C are repeated. From this, the force 107 directed radially outward of the cylinder applied to the powder 4 from the squeegee 150 is smaller than when the squeegee 150 does not vibrate, but includes a component 108 in the direction opposite to the relative movement direction 7 of the base material 3 with respect to the squeegee 150, and the force 106 that slides on the contact surface (squeegee surface 151) of the squeegee 150 becomes smaller than when the squeegee 150 does not vibrate. Therefore, it is not possible to promote the entry of the powder 4 into the gap between the squeegee 150 and the base material 3. From this, for example, when the powder 4 is very small such as having a particle diameter of several tens of μm to sub-microns and is likely to aggregate and has low fluidity, the effect of suppressing the retention of the powder 4 and the generation of bridges is not sufficient, and it is difficult to level the powder layer so that the thickness of the powder layer becomes uniform.

[0021] Next, the case where the cylindrical squeegee 150 described in Patent Document 2 is vibrated in a direction perpendicular to the relative movement direction 7 of the base material 3 with respect to the squeegee 150 (vibration direction B in FIG. 11) while maintaining the shortest distance 109 between the squeegee 150 and the base material 3 will be similarly described.

[0022] FIGS. 14A and 14B are vector diagrams showing the forces applied to the powder 4 when the powder 4 comes into contact with the cylindrical squeegee 150 vibrated in the vibration direction B in FIG. 11.

[0023] Here, FIG. 14A shows a vector diagram when the cylindrical squeegee 150 vibrates in one direction perpendicular to the relative movement direction 7 of the base material 3 while maintaining the shortest distance 109 between the squeegee 150 and the base material 3, as seen from above (looking through the squeegee 150 at the powder 4) of the force 111 with which the powder 4 pushes the squeegee 150 (the resultant force of the force 104 due to the conveyance of the base material 3 and the force 110 applied to the powder 4 from the vibrating squeegee 150). Further, FIG. 14B is a vector diagram showing the case when viewed from the side of the force 107 received by the powder 4 from the squeegee 150 as the resistance force of the force 105 obtained by decomposing the force 111 with which the powder 4 pushes the squeegee 150 in FIG. 14A.

[0024] First, when the squeegee 150 vibrates in one direction perpendicular to the relative movement direction 7 of the base material 3 while maintaining the shortest distance 109 between the squeegee 150 and the base material 3, as shown in Fig. 14A, when the powder body 4 is conveyed by the base material 3, the resultant force of the force 104 that the powder body 4 pushes the squeegee 150 and the force 110 applied to the powder from the vibrating squeegee 150 becomes the force 111 that the powder body 4 pushes the squeegee. Here, as shown in Fig. 14B, when this force is decomposed into the force 105 that perpendicularly presses the contact surface (squeegee surface 151) of the squeegee 150 and the force 106 that slides on the contact surface (squeegee surface 151) of the squeegee 150, substantially, the force 110 applied to the powder body 4 from the vibrating squeegee 150 does not act, and only the force 104 that the powder body 4 pushes the squeegee 150 due to being conveyed by the base material 3 acts. That is, it becomes the same state as when the powder body 4 comes into contact with the non-vibrating cylindrical squeegee 150 shown in Fig. 12. As a result, the powder body 4 receives a force 107 directed outward in the radial direction of the cylinder as a resistance force against the force 105 that perpendicularly presses the contact surface (squeegee surface 151) of this squeegee 150. This force 107 directed outward in the radial direction of the cylinder includes a component 108 in the direction opposite to the relative movement direction 7 of the base material 3 similar to the case where the squeegee 150 shown in Fig. 12 does not vibrate. Also, regarding the force 106 that slides on the contact surface (squeegee surface 151), there is little change compared to the case where the squeegee 150 shown in Fig. 12 does not vibrate, and no improvement effect can be obtained. From these facts, when the fluidity of the powder body 4 is low, the powder body 4 stays on the upstream side in the relative movement direction 7 of the base material 3 of the cylindrical squeegee 150. For this reason, it becomes a factor for a bridge to occur between the cylindrical squeegee 150 and the base material 3 (metal foil).

[0025] Also, here, the case where the cylindrical squeegee 150 vibrates in one direction perpendicular to the relative movement direction 7 of the base material 3 while maintaining the shortest distance 109 between the squeegee 150 and the base material 3 has been described. However, since the same state occurs when vibrating in the other direction which is the reverse direction, the description here is omitted.

[0026] Thus, when vibrating in a direction perpendicular to the relative movement direction 7 of the substrate 3 (vibration direction B in FIG. 11) while maintaining the shortest distance 109 between the columnar squeegee 150 and the substrate 3 described in Patent Document 2, the states shown in FIGS. 14A and 14B are obtained. Therefore, the force 107 directed radially outward of the column includes a component 108 in the direction opposite to the relative movement direction 7 of the substrate 3 similar to the case where the squeegee 150 does not vibrate. Furthermore, with respect to the case where the squeegee 150 does not vibrate, no improvement effect is obtained on the force 106 that slides on the contact surface (squeegee surface 151) of the squeegee 150, and the powder 4 cannot be promoted to enter the gap between the squeegee 150 and the substrate 3. From this, for example, in the case of very small powder 4 with a particle diameter of several tens of μm to submicron, which is easily aggregated and has low fluidity of the powder 4, the effect of suppressing the retention of the powder 4 and the generation of bridges is not sufficient, and it is difficult to flatten the powder layer so that the thickness of the powder layer becomes uniform.

[0027] Therefore, an object of the present disclosure is to provide a squeegee and a powder coating apparatus capable of forming a powder layer with little film thickness variation on the surface of a substrate.

[0028] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are all examples showing comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, steps, order of steps, etc. shown in the following embodiments are examples and are not intended to limit the present disclosure. In addition, among the components in the following embodiments, the components not described in the independent claims are described as optional components.

[0029] Each drawing is a schematic diagram and is not necessarily drawn precisely. Also, in each drawing, the same reference numerals are given to substantially the same configurations, and duplicate descriptions may be omitted or simplified.

[0030] In the following, terms indicating the relationship between elements such as uniform, parallel, flat, and orthogonal, terms indicating the shape of elements such as powdery, and numerical ranges do not represent only a strict meaning, but rather mean substantially equivalent ranges, for example, including differences of about several percent.

[0031] In addition, embodiments will be described below with appropriate reference to the drawings, but detailed descriptions may be omitted as necessary. For example, detailed descriptions of well-known matters and duplicate descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate understanding by those skilled in the art.

[0032] (Embodiment 1) FIG. 1A is a schematic diagram showing a powder coating apparatus according to Embodiment 1. FIG. 1B is a schematic diagram showing a squeegee 1 and a powder coating apparatus 2 according to Embodiment 1. Further, in FIG. 1B, the shortest distance 8 between the part 5 and the base material 3 due to the vibration of the part 5 and the shortest distance 9 between the part 6 and the base material 3 due to the vibration of the part 6 are illustrated. Note that the shortest distance 8 between the part 5 and the base material 3 may vary and is not limited to a certain value.

[0033] As shown in FIG. 1A, the powder coating apparatus 2 is an apparatus that coats the powder 4 on the surface 3a of the sheet-like base material 3 while transporting the base material 3 by a transport device which is a driving means. Specifically, the powder coating apparatus 2 continuously supplies the powder 4 using the powder supply unit 18 on the surface 3a of the base material 3 while transporting the base material 3 by the transport device. Further, the powder coating apparatus 2 may form a powder layer on the surface of the base material 3 by continuously compressing the base material 3 and the powder 4 on the base material 3 together by a roll press.

[0034] The powder coating apparatus 2 includes a powder supply unit 18 that supplies the powder 4 onto the surface 3a of the base material 3, a squeegee 1 that is arranged so that a gap is formed between the squeegee 1 and the base material 3 and adjusts the thickness of the powder layer composed of the powder 4 supplied onto the base material 3, and a driving unit 19 that relatively moves the base material 3 and the squeegee 1 in a certain direction.

[0035] By relatively moving such a squeegee 1 in a certain direction while forming a desired gap with respect to the base material 3, the thickness of the powder layer made of the powder 4 supplied onto the base material 3 can be leveled (smoothed uniformly). Further, the squeegee 1 has a vibration direction of a portion 5 (first portion) that vibrates in contact with the powder 4 on the upstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1, and a vibration direction of a portion 6 (second portion) that vibrates in contact with the powder 4 on the downstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1, which are different from each other.

[0036] The vibration direction of the portion 5 is a direction in which the powder 4 is crushed. Further, the vibration direction of the portion 6 is a direction in which the powder 4 is flattened.

[0037] More specifically, the vibration direction of the portion 5 is a direction in which the surface 5a of the portion 5 that vibrates in contact with the powder 4 approaches and separates from the base material 3. Further, the vibration direction of the portion 6 is a direction in which vibration is performed while maintaining the shortest distance 9 between the surface 6a of the portion 6 that vibrates in contact with the powder 4 and the base material 3. For example, it may be parallel to the movement direction 7 of the base material 3 like the vibration direction 13 of the portion 6, or may be orthogonal to the movement direction of the base material 3 like the vibration direction 14 of the portion 6. That is, the squeegee 1 can vibrate in different directions at the portion 5 and the portion 6. Further, in the present embodiment, the vibration direction of the portion 5 and the vibration direction of the portion 6 are orthogonal to each other.

[0038] In this embodiment, the part 5 and the part 6 are driven by the driving unit 19, but it is not limited thereto. For example, the driving unit 19 may include a vibration generator and a conveying device. The vibration generator vibrates the part 5 and the part 6 in different directions. Specifically, the vibration generator applies high-frequency vibrations in the vicinity of the ultrasonic band to each of the part 5 and the part 6, thereby causing high-frequency vibrations in the band of 2 kHz or more and 300 kHz to each of the part 5 and the part 6. Such a vibration generator applies vibrations to each of the part 5 and the part 6 simultaneously or individually. The conveying device can convey the base material 3 together with the powder 4 by moving the base material 3 in a predetermined direction. The conveying device continuously feeds out the base material 3 wound in a roll shape or intermittently feeds out the base material 3.

[0039] The part 5 vibrates along the direction (the direction of approaching and separating) in which the angle formed by the surface 3a of the base material 3 and the vibration direction is 90°. That is, the vibration direction of the part 5 is perpendicular to the base material 3. Further, the part 6 vibrates while maintaining the shortest distance 9 between the surface 6a of the part 6 in contact with the powder 4 and the surface 3a of the base material 3. That is, the part 6 vibrates along the direction parallel to the surface 3a of the base material 3. Here, the shortest distance 9 means the distance of the narrowest part of the gap between the part 6 and the base material 3.

[0040] Further, the powder coating apparatus 2 of this embodiment includes a powder supply unit 18 that continuously supplies the powder 4 onto the surface 3a of the base material 3, a squeegee 1 that is arranged so that a gap is formed between the squeegee 1 and the base material 3, and that adjusts the thickness of the powder layer formed of the powder 4 supplied onto the base material 3, and a driving unit 19 that relatively moves the base material 3 and the squeegee 1 in a certain direction (the same or different directions).

[0041] The frequency at which the parts 5 and 6 of the squeegee 1 vibrate is, for example, 2 kHz or more and 300 kHz or less.

[0042] The powder 4 may be any powdery substance. For example, a particle group containing an active substance with an average particle diameter (D50) of 0.005 μm or more and 50 μm or less can be used. The average particle diameter (D50) may be the volume-based median diameter calculated from the measurement values of the particle size distribution by the laser diffraction / scattering method. The average particle diameter (D50) can be measured using a commercially available laser analysis / scattering type particle size distribution measuring device.

[0043] FIGS. 2A to 2C are vector diagrams showing the forces applied to the powder 4 when the powder 4 comes into contact with the surface 5a of the portion 5 by vibrating the portion 5 in a direction in which the angle formed by the vibration direction of the portion 5 and the surface 3a of the base material 3 is 90° in FIG. 1B. In FIGS. 2A to 2C, the planar squeegee 1 is illustrated, but similar vector diagrams can be considered even when the surface 5a of the portion 5 is R-shaped or planar. The same applies to FIGS. 4A to 4C and FIGS. 6A to 6D hereinafter.

[0044] Here, FIG. 2A is a vector diagram showing the force 111a with which the powder 4 presses the surface 5a of the portion 5 (the resultant force of the force 104a with which the powder 4 conveyed to the base material 3 presses the surface 5a of the portion 5 and the force 110a applied to the powder 4 from the vibrating portion 5) when the surface 5a of the portion 5 approaches the base material 3 side (when moving in the first direction when the squeegee 1 vibrates). FIG. 2B is a vector diagram showing the force 105a that presses the surface 5a of the portion 5 perpendicularly and the force 112 that the powder 4 receives from the portion 5 as the resistance to the force 105a, obtained by decomposing the force 111a with which the powder 4 presses the surface 5a of the portion 5 in FIG. 2A. FIG. 2C is a vector diagram showing the case where the portion 5 is separated from the base material 3 (when moving in the second direction, which is the direction opposite to the first direction when the squeegee 1 vibrates).

[0045] In the case where the part 5 vibrates closer to and away from the surface 3a of the base material 3 so that the angle formed by the vibration direction of the part 5 and the surface 3a of the base material 3 is 90° in this embodiment, when the surface 5a of the part 5 is close to the base material 3 side, as shown in FIG. 2A, the resultant force of the force 104a that the powder 4 presses against the surface 5a of the part 5 by being conveyed to the base material 3 and the force 110a applied to the powder 4 from the vibrating surface 5a of the part 5 becomes the force 111a that the powder 4 presses against the surface 5a of the part 5. As shown in FIG. 2B, this force 111a that the powder 4 presses against the surface 5a of the part 5 is decomposed into a force 105a that presses perpendicularly against the contact surface of the surface 5a of the part 5 by the powder 4 and a force 106a that slides on the contact surface of the surface 5a of the part 5. At this time, the powder 4 receives a force 112 that is perpendicular to the contact surface of the surface 5a of this part 5 and directed outward of the part 5 as a resistance force against the force 105a that presses perpendicularly against the contact surface of the surface 5a of the part 5.

[0046] Here, paying attention to the component 113 (the force in the direction opposite to the moving direction 7) obtained by decomposing the force 112 that is perpendicular to the contact surface of the surface 5a of this part 5 and directed outward of the part 5, the component 113 can be made smaller compared to the case where the squeegee 150 shown in FIG. 12 does not vibrate (although FIG. 12 is shown as a cylindrical squeegee 150, the same applies even when the squeegee surface 151 has an R shape or a planar shape). For this reason, in this embodiment, it is possible to suppress the retention of the powder 4 on the upstream side in the relative moving direction 7 of the base material 3 with respect to the squeegee 1. That is, an effect can be obtained of suppressing the generation of a bridge between the squeegee 1 and the base material 3.

[0047] Similarly, paying attention to the force 106a that slides on the contact surface of the surface 5a of the part 5, which is obtained by decomposing the force 111 that the powder 4 presses against the surface 5a of the part 5, the force 106a can be made larger compared to the case where the squeegee 150 shown in FIG. 12 does not vibrate. For this reason, in this embodiment, an effect can be obtained of promoting the entry of the powder 4 into the gap between the squeegee 1 and the base material 3.

[0048] Also, when the surface 5a of the part 5 moves in a direction away from the base material 3 while the part 5 vibrates, as shown in FIG. 2C, the movement of the surface 5a of the part 5 away from the powder 4 occurs. Therefore, the surface 5a of the part 5 does not exert an action related to the retention and bridge formation on the powder 4.

[0049] From these facts, when the part 5 vibrates in proximity to and away from the surface 3a of the base material 3 such that the angle formed between the vibration direction of the part 5 and the surface 3a of the base material 3 is 90°, compared with the case where the squeegee 150 shown in FIG. 12 does not vibrate, an effect of suppressing the retention and bridge formation of the powder 4 and an effect of promoting the entry of the powder 4 into the gap between the squeegee 1 and the base material 3 can be obtained. From this, in the prior art where the squeegee 150 shown in FIG. 12 does not vibrate, even in the case of very small powder 4 such as having a particle diameter in the range of several tens of μm to submicrons, which is likely to aggregate and has low fluidity of the powder 4, it becomes possible to crush the powder 4 and flatten the powder layer so that the thickness of the powder layer becomes uniform.

[0050] Also, as shown in FIGS. 13B and 13C, even in the prior art where vibration is performed in the relative movement direction 7 of the base material 3 and the reverse direction (vibration direction A in FIG. 11) while maintaining the shortest distance 109 between the squeegee 150 and the base material 3, the component 108 (the force in the direction opposite to the relative movement direction 7 of the base material 3) obtained by decomposing the force 107, which is the resistance applied to the powder 4 from the squeegee 150, becomes smaller compared with the case where the squeegee 150 does not vibrate. Also, since the component of the force 106 that slides on the contact surface (squeegee surface 151) of the squeegee 150 becomes smaller, in the case of very small powder 4 such as having a particle diameter in the range of several tens of μm to submicrons, which is likely to aggregate and has low fluidity of the powder 4, it has been difficult to flatten the powder layer so that the thickness of the powder layer becomes uniform. However, in the present embodiment, by vibrating the part 5 in proximity to and away from the surface 3a of the base material 3 such that the angle formed between the vibration direction of the part 5 and the surface 3a of the base material 3 is 90°, it becomes possible to crush the powder 4 and flatten the powder layer so that the thickness of the powder layer becomes uniform.

[0051] Here, when the portion 5 vibrates in proximity to and away from the surface 3a of the base material 3 such that the angle formed between the vibration direction of the portion 5 and the surface 3a of the base material 3 is 90°, for example, by vibrating the portion 5 at a frequency of 2 kHz or more and 300 kHz or less, a friction resistance reduction effect between the powder bodies 4 can be obtained. Further, as a synergistic effect due to the friction resistance reduction effect, from the powder accumulation on the upstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1, the powder body 4 enters the gap between the squeegee 1 and the base material 3 while the flow path is constricted, and a high crushing / dispersion effect of the powder body 4 can also be obtained. As a result, in addition to improving the uniformity of the thickness of the powder layer, an effect of improving the uniformity inside the powder layer that suppresses aggregation and bias can be obtained together.

[0052] Further, in the squeegee 1 of the present embodiment, the portion 5 vibrates in proximity to and away from the surface 3a of the base material 3 such that the angle formed between the vibration direction of the portion 5 and the surface 3a of the base material 3 is 90°. Further, the portion 6 can be vibrated while maintaining the shortest distance 9 between the surface 6a of the portion 6 and the base material 3. Thereby, in the squeegee 1 of the present embodiment, compared with the case where the squeegee 150 shown in FIG. 12 does not vibrate, an effect of suppressing the retention and generation of bridges of the powder body 4 and an effect of promoting the entry of the powder body 4 into the gap between the squeegee 1 and the base material 3 can be obtained.

[0053] Here, the vibration direction of the portion 6 may be a vibration direction 13 parallel to the relative movement direction 7 of the base material 3 with respect to the squeegee 1, or may be a vibration direction 14 (front and back in the plane of the paper) perpendicular to the movement direction 7.

[0054] Thereby, by causing the portion 5 to vibrate in proximity to and away from the surface 3a of the base material 3 such that the angle formed between the vibration direction of the portion 5 and the surface 3a of the base material 3 is 90°, an increase in film thickness variation can be suppressed, and while obtaining a retention suppression effect, a bridge suppression effect, a fluidity imparting effect, and a crushing / dispersion effect, the uniformity of the film thickness can be made compatible.

[0055] By vibrating the squeegee 1 at a frequency of, for example, 2 kHz or more and 300 kHz or less, the friction resistance reduction effect between the powders 4 can be obtained. As a synergistic effect, while maintaining the shortest distance 9 between the surface 6a of the portion 6 and the base material 3, the flattening effect of the powder layer can be further improved by vibrating.

[0056] In addition, for example, the very small powder 4 with a particle size of several tens of μm to sub-micron will progress in aggregation when in a static state, and the fluidity of the powder 4 will decline. Therefore, in the present embodiment, by continuously processing the powder 4 at a plurality of portions (portion 5 and portion 6) with different vibration directions, while maintaining the state where the powder 4 is imparted with fluidity, the processing at each portion (portion 5 and portion 6) of the squeegee 1 becomes possible. Thus, it is possible to obtain many effects such as a residence suppression effect, a bridge suppression effect, a crushing / dispersion effect, and a film thickness uniformity.

[0057] (Embodiment 2) FIG. 3 shows a schematic view of the squeegee 1 and the powder coating apparatus 2 according to the present embodiment.

[0058] In Embodiment 2, in the direction where the angle formed by the vibration direction of the portion 5 and the surface 3a of the base material 3 is not 90°, on the upstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1, the surface 5a of the portion 5 and the base material 3 are close to each other, and on the downstream side, they are separated. Except for vibrating the squeegee 1, it is the same as Embodiment 1. Therefore, the differences from Embodiment 1 will be described below.

[0059] FIGS. 4A to 4C are vector diagrams showing the forces applied to the powder 4 when the powder 4 contacts the surface 5a of the portion 5 in the case where the vibration is performed so as to approach toward the upstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1 and separate toward the downstream side, instead of the direction where the angle formed by the vibration direction of the portion 5 and the surface 3a of the base material 3 is 90° in FIG. 3.

[0060] Here, FIG. 4A is a vector diagram showing the force 111a with which the powder 4 presses against the surface 5a of the part 5 when the surface 5a of the part 5 is close to the base material 3 side (the resultant force of the force 104a with which the powder 4 presses against the surface 5a of the part 5 as it is conveyed to the base material 3 and the force 110a applied to the powder 4 from the vibrating part 5). Further, FIG. 4B is a vector diagram showing the force perpendicular to the surface 5a of the part 5, which is obtained by decomposing the force 111a with which the powder 4 presses against the surface 5a of FIG. 4A, and the force received by the powder 4 from the part 5 as the resistance force to the force 105a. Further, FIG. 4C is a vector diagram showing the case when the part 5 is separated from the base material 3.

[0061] In the present embodiment, instead of the direction in which the angle formed by the vibration direction of the part 5 and the surface 3a of the base material 3 is 90°, when the part 5 vibrates in a direction approaching the upstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1 and separating toward the downstream side, when approaching the upstream side, as shown in FIG. 4A, the resultant force of the force 104a with which the powder 4 presses against the surface 5a of the part 5 as it is conveyed to the base material 3 and the force 110a applied to the powder 4 from the vibrating surface 5a of the part 5 becomes the force 111a with which the powder 4 presses against the surface 5a of the part 5. This force 111a with which the powder 4 presses against the surface 5a of the part 5 is decomposed into a force 105a that presses perpendicularly against the contact surface of the surface 5a of the part 5 and a force 106a that slides on the contact surface of the surface 5a of the part 5, as shown in FIG. 4B. This powder 4 receives a force 112 that is the resistance force to the force 105a that presses perpendicularly against the contact surface of the surface 5a of this part 5.

[0062] Here, when paying attention to the component 113 of the force 112, the component 113 can be made smaller compared to the case where the squeegee 150 shown in FIG. 12 does not vibrate (although FIG. 12 is shown as a cylindrical squeegee 150, the same applies even when the squeegee surface 151 is R-shaped or planar). For this reason, in the present embodiment, on the upstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1, the retention of the powder 4 can be suppressed. That is, an effect can be obtained of suppressing the generation of a bridge between the squeegee 1 and the base material 3.

[0063] Similarly, when focusing on the force 106a that slides on the contact surface of the surface 5a of the part 5, which is the decomposition of the force 111a by which the powder 4 presses on the surface 5a of the part 5, there is no change from the case where the squeegee 150 shown in FIG. 12 does not vibrate, and it is not likely to deteriorate as in the prior art shown in FIG. 13B.

[0064] From these facts, in the present embodiment, by causing vibration that approaches toward the upstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1 and separates toward the downstream side, while maintaining the shortest distance 109 between the columnar squeegee 150, which is the prior art shown in FIGS. 13B and 13C, and the base material 3, compared to the case of vibrating in the relative movement direction 7 of the base material 3 and the reverse direction thereof (vibration direction A in FIG. 11), the effects of suppressing the retention of the powder 4 and the generation of bridges and promoting the entry of the powder 4 into the gap between the squeegee 1 and the base material 3 can be obtained. For example, in the case of a very small powder 4 having a particle diameter of several tens of μm to submicrons, which is likely to aggregate and has low fluidity, in addition to improving the uniformity of the thickness of the powder layer, the effect of improving the uniformity inside the powder layer that suppresses aggregation and deviation can be obtained together. From this, a homogeneous powder layer with a small thickness variation on the surface 3a of the base material 3 and with aggregation and deviation suppressed inside can be formed.

[0065] Still, when the surface 5a of the part 5 and the base material 3 are separated on the downstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1, as shown in FIG. 4C, the movement is in the direction in which the surface 5a of the part 5 moves away from the powder 4, so the effect of suppressing the retention and the generation of bridges of the surface 5a of the part 5 on the powder 4 does not act so much.

[0066] Also, regarding the form, vibration, and effect of the part 6 that vibrates in contact with the powder 4 on the downstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1 in the second embodiment, since they are the same as those in the first embodiment, the description is omitted.

[0067] (Embodiment 3) FIG. 5 is a schematic view of the squeegee 1 and the powder coating apparatus 2 according to the present embodiment.

[0068] In the present embodiment, it is not the direction in which the angle formed by the vibration direction of the portion 5 and the surface 3a of the base material 3 is 90°, but is close to the downstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1 and vibrates so as to be spaced apart toward the upstream side. Since it is the same as the first embodiment except for this, only the differences from the first embodiment will be described below.

[0069] Figures 6A to 6D show that in FIG. 5, the surface 5a of the portion 5 that vibrates in contact with the powder 4 on the upstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1 is not in the direction in which the angle formed by the vibration direction of the portion 5 and the surface 3a of the base material 3 is 90°. Further, FIGS. 6A to 6D are vector diagrams showing the force applied to the powder 4 when the portion 5 is vibrated so as to be close to the downstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1 and to be spaced apart toward the upstream side, by the contact of the powder 4 with the surface 5a of the portion 5. Here, FIG. 6A is a vector diagram showing the force 111a with which the powder 4 presses the surface 5a of the portion 5 (the resultant force of the force 104a with which the powder 4 presses the surface 5a of the portion 5 as the powder 4 is conveyed to the base material 3 and the force 110a applied from the vibrating portion 5 to the powder 4) when the surface 5a of the portion 5 and the base material 3 are close to each other on the downstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1. Further, FIG. 6B is a vector diagram showing the force 105a that vertically presses the surface 5a of the portion 5 obtained by decomposing the force 111a with which the powder 4 presses the surface 5a of the portion 5 in FIG. 6A, and the force received by the powder 4 from the portion 5 as the reaction force of the force 105a. Further, FIG. 6C is a vector diagram showing the force 111a with which the powder 4 presses the surface 5a of the portion 5 when the portion 5 is separated from the base material 3. Further, FIG. 6D is a vector diagram showing the force 105a that vertically presses the surface 5a of the portion 5 obtained by decomposing the force 111a with which the powder 4 presses the surface 5a of the portion 5 in FIG. 6C, and the force received by the powder 4 from the portion 5 as the reaction force of the force.

[0070] In the present embodiment, instead of the direction in which the angle formed by the vibration direction of the part 5 and the surface 3a of the base material 3 is 90°, when vibrations are generated that approach toward the downstream side of the relative movement direction 7 of the base material 3 and separate toward the upstream side, when approaching toward the downstream side, as shown in FIG. 6A, the resultant force of the force 104a that the powder body 4 presses against the surface 5a of the part 5 by being conveyed to the base material 3 and the force 110a applied to the powder body 4 from the vibrating surface 5a of the part 5 becomes the force 111a that the powder body 4 presses against the surface 5a of the part 5. As shown in FIG. 6B, this force 111a that the powder body 4 presses against the surface 5a of the part 5 is decomposed into a force 105a that presses perpendicularly against the contact surface of the surface 5a of the part 5 by the powder body 4 and a force 106a that slides on the contact surface of the surface 5a of the part 5. Further, as a resistance force against the force 105a that the powder body 4 presses perpendicularly against the contact surface of the surface 5a of the part 5, the powder body 4 receives a force 112 that is perpendicular to the contact surface of the surface 5a of the part 5 and directed outward from the part 5.

[0071] Here, focusing on the force 106a that slides on the contact surface of the squeegee 1 obtained by decomposing the force 111a that the powder body 4 presses against the surface 5a of the part 5, it can be made extremely large compared to the case where the squeegee 150 shown in FIG. 12 does not vibrate (although FIG. 12 is shown as a cylindrical squeegee 150, the same applies even when the squeegee surface 151 has an R shape or a planar shape). For this reason, in the present embodiment, a great effect can be obtained that promotes the entry of the powder body 4 into the gap between the squeegee 1 and the base material 3.

[0072] Similarly, as a resistance force against the force 105a that presses perpendicularly against the contact surface of the surface 5a of the part 5, the powder body 4 receives a force 112 that is perpendicular to the contact surface of the surface 5a of the part 5 and directed outward from the inside of the part 5. Here, focusing on the component 113 that is in the direction opposite to the relative movement direction 7 of the base material 3, it is equivalent to the case where the squeegee 150 shown in FIG. 12 does not vibrate and is difficult to deteriorate (although FIG. 12 is shown as a cylindrical squeegee 150, the same applies even when the squeegee surface 151 has an R shape or a planar shape).

[0073] Also, when the vibration is not in the direction where the angle formed by the vibration direction of the part 5 and the surface 3a of the base material 3 is 90°, but is made to approach toward the downstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1 and separate toward the upstream side, when it is separating toward the upstream side, as shown in FIG. 6C, the resultant force of the force 104a that the powder body 4 presses the surface 5a of the part 5 by being conveyed to the base material 3 and the force 110a applied to the powder body from the vibrating surface 5a of the part 5 becomes the force 111a that the powder body 4 presses the surface 5a of the part 5. As shown in FIG. 6D, this force 111a that the powder body 4 presses the surface 5a of the part 5 is decomposed into a force 105a that vertically presses the contact surface of the surface 5a of the part 5 and a force 106a that slides on the contact surface of the surface 5a of the part 5. The powder body 4 receives a force 112 that is perpendicular to the contact surface of the surface 5a of this part 5 and directed from the inside of the part 5 toward the outside as a resistance force against the force 105a that vertically presses the contact surface of the surface 5a of the part 5.

[0074] Here, paying attention to the force 106a that slides on the contact surface of the surface 5a of the part 5, into which the force 111a that the powder body 4 presses the surface 5a of the part 5 is decomposed, it becomes smaller compared to the case where the squeegee 150 shown in FIG. 12 does not vibrate.

[0075] Also, paying attention to the component 113 of the force 112 that the powder body 4 receives as a resistance force against the force 105a that vertically presses the contact surface of the surface 5a of the part 5, it is difficult to deteriorate in the same way as the case where the squeegee 150 shown in FIG. 12 does not vibrate (although FIG. 12 is shown with the cylindrical squeegee 150, it can be considered in the same way regardless of whether the squeegee surface 151 is R-shaped or planar).

[0076] Here, when vibration is applied not in the direction where the angle formed by the vibration direction of part 5 and the surface 3a of the base material 3 is 90°, but in a direction approaching the downstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1 and separating toward the upstream side, the states shown in FIGS. 6B and 6D are repeated. Focus on the force 106a that slides on the contact surface of the surface 5a of part 5, which is the decomposition of the force 111a with which the powder 4 presses on the surface 5a of part 5 in that case. When approaching the downstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1, the force 106a that slides on the contact surface of the surface 5a of part 5 can be made extremely large. In this case, a great effect can be obtained that promotes the entry of the powder 4 into the gap between the squeegee 1 and the base material 3. When separating toward the upstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1, although the force 106a that slides on the contact surface of the surface 5a of part 5 becomes small, in the continuous vibration operation, a great effect can be obtained that promotes the entry of the powder 4 into the gap between the squeegee 1 and the base material 3.

[0077] Also, the component 113 in the direction opposite to the relative movement direction 7 of the base material 3 of the force 112 received by the powder 4 as a resistance to the force 105a that vertically presses on the contact surface of the surface 5a of part 5 is not likely to deteriorate during the continuous vibration operation, being equivalent to the case where the squeegee 150 shown in FIG. 12 does not vibrate (although FIG. 12 is represented by a cylindrical squeegee 150, the same consideration applies regardless of whether the squeegee surface 151 is R-shaped or planar).

[0078] Thus, by repeating FIGS. 13B and 13, the component 108 of the force 107 directed radially outward of the cylinder, which the powder 4 receives as a resistance to the force 105 pressing the contact surface of the squeegee 150 vertically, can be made smaller than in the case where the squeegee 150 shown in FIG. 12 does not vibrate. In the prior art shown in FIG. 11, the force 106 obtained by decomposing the force 111 with which the powder 4 presses the squeegee 150 deteriorates and becomes smaller than in the case where the squeegee 150 does not vibrate. However, when the surface 5a of the portion 5 in the present embodiment vibrates so as to approach the downstream side in the relative movement direction 7 of the base material 3 with respect to the squeegee 1 and move away from the upstream side with respect to the base material 3, the force 106a for sliding the contact surface of the surface 5a of the portion 5 becomes extremely large. Therefore, it is possible to promote the entry of the powder 4 into the gap between the squeegee 1 and the base material 3, and an effect of suppressing the occurrence of retention and bridging of the powder 4 on the upstream side in the relative movement direction 7 of the base material 3 with respect to the squeegee 1 can be obtained. As a result, for example, even when the powder 4 is very small with a particle diameter in the range of several tens of μm to submicron and is liable to aggregate and has low fluidity, in addition to improving the uniformity of the thickness of the powder layer, an effect of improving the uniformity inside the powder layer that suppresses aggregation and deviation can be obtained together. Therefore, a homogeneous powder layer with small thickness variation on the surface 3a of the base material 3 and no aggregation and deviation inside can be formed.

[0079] Also, regarding the form, vibration, and effect of the portion 6 that vibrates in contact with the powder 4 on the downstream side in the relative movement direction 7 of the base material 3 with respect to the squeegee 1 in Embodiment 3, since they are the same as those in Embodiment 1, the description thereof is omitted.

[0080] Here, in one embodiment of the present disclosure, as an example of the powder 4, its average particle diameter (D50) was set to be 0.005 μm or more and 50 μm or less. However, the same effect can be obtained for particle diameters other than these, and it is not limited thereto.

[0081] Hereinafter, the embodiments of the present disclosure will be described in more detail using specific experimental examples. Note that the present invention is not limited by the following experimental examples, and can be appropriately modified and implemented without changing the gist thereof.

[0082] (Experimental Example) As an experimental example, a film formation of a positive electrode mixture layer 10 including a positive electrode active material 11 and a solid electrolyte 12 of an all-solid-state battery was carried out. As the positive electrode active material 11, LiNi1 / 3Co1 / 3Mn1 / 3 with an average particle diameter D50 of 5 μm was used, and as the solid electrolyte, Li2S-P2S5 with an average particle diameter D50 of 0.8 μm was used. A mixture mixed so as to have a volume ratio of 7:3 was formed into a film. Further, the mixture was supplied onto the substrate 3 on the upstream side of the relative movement direction 7 of the substrate 3 with respect to the squeegee 1, and the mixture was leveled by the squeegee 1 of Embodiments 1 to 3, so that a film formation was carried out on the aluminum foil serving as the substrate 3 with a coating width of 50 mm, a coating length of 200 mm, and a target film thickness of 300 μm. The coating speed was 10 m / min. Further, the vibration conditions of the portion 5 that vibrates in contact with the powder 4 on the upstream side of the relative movement direction 7 of the substrate 3 with respect to the squeegee 1 and the portion 6 that vibrates in contact with the powder 4 on the downstream side were the same, the vibration frequency was 35 kHz, and the amplitude was 5 μm.

[0083] Further, the vibration direction of the portion 5 that vibrates in contact with the powder 4 on the upstream side of the relative movement direction 7 of the substrate 3 with respect to the squeegee 1 was vibrated in a direction in which the angle formed by the substrate 3 and the vibration direction was 90° in Embodiment 1, in Embodiment 2, it was vibrated in a direction in which the angle formed by the substrate 3 and the vibration direction of the portion 5 was 45° on the upstream side of the relative movement direction 7 of the substrate 3 with respect to the squeegee 1, and in Embodiment 3, it was vibrated in a direction in which the angle formed by the substrate 3 and the vibration direction of the portion 5 was 45° on the downstream side of the relative movement direction 7 of the substrate 3 with respect to the squeegee 1.

[0084] Further, in each embodiment, film formation was carried out for the case where the vibration direction of the portion 6 that vibrates in contact with the powder 4 on the downstream side of the relative movement direction 7 of the substrate 3 with respect to the squeegee 1 was vibrated in the relative movement direction 7 of the substrate 3 with respect to the squeegee 1 and the reverse direction thereof, and the case where it was vibrated in a direction perpendicular to the relative movement direction 7 of the substrate 3 with respect to the squeegee 1.

[0085] Further, as comparative examples, while maintaining the shortest distance 109 between the ski squeegee 150, which is the prior art shown in FIG. 11, and the base material 3, the ski squeegee 150 was vibrated in the relative movement direction 7 of the base material 3 with respect to the ski squeegee 150 and the reverse direction thereof (vibration direction A in FIG. 11) (Comparative Example 1), and the cylindrical ski squeegee 150 was vibrated in a direction perpendicular to the relative movement direction 7 of the base material 3 with respect to the ski squeegee 150 while maintaining the shortest distance 109 between the ski squeegee 150 and the base material 3 (vibration direction B in FIG. 11) (Comparative Example 2). Film formation was similarly carried out. Here, the vibration conditions of the ski squeegee 150 were the conditions disclosed in Patent Document 2, with the vibration frequency of the ski squeegee 150 being 700 Hz and the amplitude being 5 μm.

[0086] The in-plane film thickness variation of the obtained positive electrode mixture layer 10 was measured using a laser displacement meter as shown in FIG. 7, across the powder layer at 5-mm intervals in the coating width direction and the coating direction, respectively. Regarding the maximum value of the film thickness variation ((maximum film thickness - minimum film thickness) / (average film thickness)) in each powder layer, less than ±2.5% was designated as "A", ±2.5% or more and less than ±5% was designated as "B", and ±5% or more was designated as "C".

[0087] Also, when observing the cross-section of the positive electrode mixture layer 10 as shown in FIG. 8, the total area of the agglomerated portions of the solid electrolyte 12 with a cross-sectional area of 100 μm 2 or more was measured. If it was less than 2% with respect to the cross-sectional area of the positive electrode mixture layer 10, it was designated as "A", 2% or more and less than 10% was designated as "B", and 10% or more was designated as "C".

[0088] The results of each embodiment according to the present disclosure are shown in Table 1 of FIG. 15. Also, the results of the comparative examples according to the prior art are shown in Table 2 of FIG. 16.

[0089] In Experimental Examples 1 to 6, which are one embodiment of the present disclosure, the vibration direction of the vibrating portion 5 in contact with the powder 4 on the upstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1 and the vibration direction of the vibrating portion 6 in contact with the powder 4 on the downstream side are different. Under any conditions, both the effect of suppressing the retention of the powder 4 and the generation of bridges and the effect of promoting the entry of the powder 4 into the gap between the squeegee 1 and the base material 3 can be obtained, and both the reduction of film thickness variation and the suppression of aggregation of the solid electrolyte 12 can be achieved.

[0090] On the other hand, in Experimental Examples 7 to 8, in which the columnar squeegee 150 of the prior art is vibrated while maintaining the shortest distance 109 between the squeegee 150 and the base material 3, although it is insufficient, film formation can be achieved with a certain degree of film thickness variation, but the compatibility between the reduction of film thickness variation and the suppression of aggregation of the solid electrolyte 12 cannot be achieved. This is because, in order to obtain a high crushing and dispersion effect of the powder 4, for example, when setting higher frequency conditions, although there is an improvement tendency regarding the aggregation state, the film thickness variation tends to deteriorate. Conversely, in order to suppress the film thickness variation, for example, when setting lower frequency conditions, although an improvement effect can be seen regarding the film thickness variation, the aggregation state tends to deteriorate.

[0091] Thus, in the prior art in which the columnar squeegee 150 is vibrated while maintaining the shortest distance 109 between the squeegee 150 and the base material 3, it is difficult to achieve both the ensuring of film thickness accuracy and the uniformity of film quality. In contrast, in the present embodiment in which the vibration direction of the vibrating portion 5 in contact with the powder 4 on the upstream side of the relative movement direction 7 of the base material 3 with respect to the squeegee 1 and the vibration direction of the vibrating portion 6 in contact with the powder 4 on the downstream side are different, such compatibility becomes possible.

[0092] Here, in the present embodiment, although the powder 4 is taken as an example of a particle group containing an active material, the same effect can be obtained in powders of other functional materials, and the raw material, composition, particle shape, and particle diameter are not particularly limited.

[0093] Further, the powder 4 may contain only one type of powder or may contain two or more types of powders. When the powder 4 is a compound powder composed of a plurality of types of powders, if high-frequency vibration near the ultrasonic band is applied to the squeegee 1 to flatten the powder 4, the dispersibility of the plurality of types of powder 4 is improved. That is, the plurality of types of powder 4 are more likely to be dispersed with each other, and it is difficult for a specific type of powder 4 to be unevenly formed into a film on the substrate 3. This is because the high-frequency vibration near the ultrasonic band is transmitted to the powder 4 existing in a certain region before reaching the squeegee 1 due to the high-frequency vibration near the ultrasonic band of the squeegee 1, and the plurality of types of particles constituting the powder 4 vibrate and flow, so that the plurality of types of particles constituting the powder 4 are mixed with each other, and it is considered that the dispersibility is improved.

[0094] Further, the substrate 3 is a long thin plate and is unwound from a wound state and wound up after coating, but the substrate 3 is not limited to such a form. The substrate 3 having a desired shape may be relatively moved with respect to the squeegee 1 by the driving unit 19, and after the coating of the powder 4 is completed, a new substrate 3 may be intermittently relatively moved with respect to the squeegee 1 by the driving unit 19. Further, the substrate 3 may not be wound in a roll shape. The substrate 3 is not limited to a sheet shape, and any shape that can be coated with the powder 4 using the powder coating apparatus 2 may be used. Further, in the present embodiment, the substrate 3 is a current collector including a metal foil, but the material is not particularly limited, and any substrate that can be coated with the powder 4 using the powder coating apparatus 2 can be used.

[0095] (Other modifications, etc.) As described above, the present disclosure has been described based on Embodiments 1 to 3, but the present disclosure is not limited to these Embodiments 1 to 3 and the like.

[0096] In addition, forms obtained by making various modifications conceivable by those skilled in the art to Embodiments 1 to 3, and forms realized by arbitrarily combining the components and functions in Embodiments 1 to 3 without departing from the gist of the present disclosure are also included in the present disclosure.

[0097] According to the present disclosure, a powder layer with little film thickness variation can be formed on the surface of the substrate.

Industrial Applicability

[0098] The squeegee and powder coating apparatus of the present disclosure can produce a powder layer that is solvent-free, has little variation in film thickness, and is uniform, and thus can also be applied to the formation of a composite layer or the like of a high-quality energy device (for example, an all-solid-state battery).

Explanation of Signs

[0099] 1 Squeegee 2 Powder coating apparatus 3 Substrate 3a Surface of the substrate 4 Powder 5 Site (first site) 5a Surface of site 5 6 Site (second site) 6a Surface of site 6 7 Relative movement direction of the substrate with respect to the squeegee 8 Shortest distance between site 5 and the substrate 9 Shortest distance between site 6 and the substrate 10 Positive electrode composite layer 11 Positive electrode active material 12 Solid electrolyte 13 Vibration direction of site 6 parallel to the relative movement direction 7 of the substrate 3 with respect to the squeegee 1 14 Vibration direction of site 6 perpendicular to the relative movement direction 7 of the substrate 3 with respect to the squeegee 1 18 Powder supply unit 19 Driving unit 100 Blade-shaped squeegee in the conventional method 101 Surface of the blade-shaped squeegee in the conventional method 102 Force with which the powder presses perpendicularly against the contact surface of the squeegee 103 Force in the direction opposite to the movement direction of the powder (relative movement direction of the substrate (metal foil) with respect to the squeegee) 104 Force with which the powder presses the squeegee as it is transported to the substrate 104a Force with which the powder 4 presses the surface 5a of site 5 as it is transported to the substrate 3 105 Force that presses perpendicularly against the contact surface of the squeegee The force that perpendicularly presses the contact surface with the surface 5a of part 5 106 The force that slides on the contact surface of the squeegee 106a The force that slides on the contact surface of the surface 5a of part 5 107 The force directed radially outward of the cylinder 108 The component in the direction opposite to the relative movement direction 7 of the base material with respect to the squeegee 109 The shortest distance between the squeegee and the base material 110 The force applied to the powder from the vibrating squeegee 110a The force applied to the powder 4 from the vibrating part 5 111 The force with which the powder 4 presses the squeegee 150, which is the resultant force of the force 104 with which the powder 4 presses the squeegee 150 due to being conveyed to the base material 3 and the force 110 applied to the powder 4 from the vibrating squeegee 150 111a The force with which the powder 4 presses the surface 5a of part 5, which is the resultant force of the force 104a with which the powder 4 presses the surface 5a of part 5 due to being conveyed to the base material 3 and the force 110a applied to the powder 4 from the surface 5a of the vibrating part 5 112 As the resistance to the force 105a that perpendicularly presses the contact surface of the surface 5a of part 5, a force perpendicular to the contact surface of the surface 5a of part 5 and directed from the inside to the outside of part 5 113 The component of the force 112, which is perpendicular to the contact surface of the surface 5a of part 5 and directed from the inside to the outside of part 5, in the direction opposite to the relative movement direction 7 of the base material 3 with respect to the squeegee 1 150 The cylindrical squeegee in the conventional method 151 The surface of the cylindrical squeegee in the conventional method

Claims

1. A squeegee for leveling the thickness of a powder layer composed of powder supplied onto a base material by relatively moving the base material in a certain direction while forming a desired gap with respect to the base material, a first part that vibrates in contact with the powder on the upstream side in the relative moving direction of the base material with respect to the squeegee, and a second part that vibrates in contact with the powder on the downstream side in the relative moving direction of the base material with respect to the squeegee, wherein the vibration direction of the first part is different from the vibration direction of the second part squeegee.

2. The vibration direction of the first part is a direction for crushing the powder, and the vibration direction of the second part is a direction for flattening the powder The squeegee according to claim 1.

3. The vibration direction of the first part is a direction in which the surface of the first part that vibrates in contact with the powder approaches and separates from the base material, and the vibration direction of the second part is a direction in which vibration is performed while maintaining the shortest distance between the surface of the second part that vibrates in contact with the powder and the base material The squeegee according to claim 2.

4. The vibration direction of the first part is a direction perpendicular to the base material The squeegee according to claim 3.

5. The vibration direction of the second part is parallel to the moving direction of the base material The squeegee according to claim 3.

6. The vibration direction of the second part is orthogonal to the moving direction of the base material The squeegee according to claim 3.

7. The frequencies for vibrating the first part and the second part are 2 kHz or more and 300 kHz or less The squeegee according to any one of claims 1 to 6.

8. A powder supply unit for supplying powder onto the surface of a base material, the squeegee according to any one of claims 1 to 7, which is arranged so that a gap is formed between the squeegee and the base material and adjusts the thickness of a powder layer composed of powder supplied onto the base material, and a driving unit for relatively moving the base material and the squeegee in a certain direction powder coating apparatus.

Images