JP2009028719A - Coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating apparatus in which a coating agent can be efficiently used. <P>SOLUTION: The coating apparatus is provided with: a housing member (15, 15a) for housing the coating agent; and a roll member (13) which is rotated to apply the coating agent to the object (2) to be coated. The roll member has an application area (13a) in the direction of a rotary shaft, on which a plurality of grooves for holding the coating agent are formed in the peripheral direction, and a non-application area (13b) which has the diameter smaller than that of the application area and is in a non-contact state with the coating agent housed in the housing member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a coating apparatus for applying a coating agent to an object to be coated using a roll member.

  Conventionally, there is one that forms a striped coating film on an object to be coated by gravure coating. This gravure coating is used for producing electrodes of secondary batteries such as lithium ion batteries.

  In the gravure coating apparatus that performs the above-described gravure coating, a gravure roll having a plurality of application regions engraved with a gravure pattern and a plurality of non-application regions not engraved with a gravure pattern is used. Then, the coating agent is supplied to the surface of the gravure roll, and the coating agent adhered to the surface of the gravure roll is rotated by rotating the gravure roll in the forward direction or the reverse direction with respect to the conveyance direction of the coating object. It is applied to the surface.

Here, in order to prevent the coating agent adhering to the non-application area of the gravure roll from being applied to the application object, a masking tape is applied to the area corresponding to the non-application area of the application object. . The masking tape is affixed to an object to be coated before the coating agent is applied, and is peeled off after the coating agent is applied to the object to be coated.
JP 2000-202358 A JP 2001-104852 A JP 2000-288462 A JP-A-11-207248 JP 2007-289829 A JP 2000-241933 A

  However, in the gravure coating using the masking tape, the problems described below occur.

  First, it is troublesome because the masking tape must be peeled off after the coating agent is applied to the object to be coated. Moreover, the masking tape that has been peeled off is discarded, but since the coating agent from the gravure roll is attached to the masking tape, the coating agent is wasted.

  Therefore, an object of the present invention is to provide a coating apparatus that can use a coating agent without waste and can apply the coating agent to a predetermined region of an object to be coated with a substantially uniform thickness.

  The coating apparatus of the present invention has a housing member that stores the coating agent, and a roll member for applying the coating agent to the object to be coated by a rotation operation. An application region in which a plurality of grooves for holding the application agent are formed in the circumferential direction, and a non-application region that has a diameter smaller than the diameter of the application region and is in a non-contact state with the application agent stored in the storage member It is characterized by having.

  Here, a blade member is provided for adjusting the amount of the coating agent that contacts the roll member and adheres to the roll member. In this blade member, the blade member is positioned at a position corresponding to the boundary between the application region and the non-application region. A notch can be formed. Further, when the blade member is formed of resin, the cut portion can be formed by utilizing the frictional force with the roll member.

  Moreover, the cover member for preventing adhesion of the coating agent to the non-application area can be provided at a position corresponding to the non-application area of the roll member. Thereby, it can prevent that a coating agent adheres to a non-application area | region, and can make a non-application area | region into a non-contact state with respect to a coating agent. On the other hand, since the non-application area in the roll member is smaller than the diameter of the application area, the roll member is arranged so that the non-application area is located away from the interface of the coating agent stored in the storage member. You can also Also in this case, the non-application area is not in contact with the application agent.

  In addition, at least the surface layer portion of the roll member can be formed of a ceramic material. More specifically, the roll member can be composed of a surface layer portion made of chromium oxide and a core portion made of stainless steel. Also, a plurality of application regions and non-application regions can be provided in the direction of the rotation axis of the roll member. In this case, the application region and the non-application region are alternately arranged in the rotation axis direction of the roll member. The above-described coating apparatus of the present invention is used for manufacturing an electrode of a secondary battery (such as a lithium ion battery). For example, the coating apparatus of the present invention can be used to apply a material (active material or the like) for forming an electrode layer to a current collector as an object to be coated.

  Moreover, each groove part formed in the application | coating area | region of a roll member can be comprised by a curved surface. More specifically, each groove part can be comprised by one continuous curved surface. Thereby, it can suppress that an application agent remains adhering to a groove part, and can apply an application agent to a coated object efficiently via a roll member. Here, the groove formed of a curved surface can be formed using a laser. Moreover, the curved surface of a groove part can be made into the shape along the one part area | region in the outer peripheral surface of a cylindrical body. The cylindrical body as used herein has a cross section having a circular shape, an elliptical shape, a shape substantially equal to a circle or an ellipse.

  In addition, the plurality of groove portions may include first and second groove portions extending in directions intersecting each other. By using the first and second groove portions, it is possible to suppress the coating agent from shifting in the application region, and to disperse the coating agent in the application region. Thereby, the layer of the coating agent applied to the article to be coated can be made to have a substantially uniform thickness.

  According to this invention, the non-application area | region is made into a non-contact state with respect to the coating agent accommodated in the accommodating member by making the diameter of the non-application area | region formed in the roll member smaller than the diameter of an application area | region. Thereby, it becomes unnecessary to arrange | position a masking tape in the part which does not apply | coat an application agent among the to-be-coated objects like the past. Therefore, the coating agent adhering to the masking tape is not discarded together with the masking tape, and the coating agent can be prevented from being wasted.

  Examples of the present invention will be described below.

  A gravure coating apparatus (coating apparatus) that is Embodiment 1 of the present invention will be described with reference to FIG. Here, FIG. 1 is a schematic diagram showing the configuration of the gravure coating apparatus of the present embodiment.

  The base material 2 as an object to be coated is fed out from a raw fabric roll (not shown) and is given tension by stretching rolls 11 and 12. The stretching rolls 11 and 12 convey the base material 2 in the direction indicated by the arrow A by rotating in the direction indicated by the arrow B1 in FIG. 1 (counterclockwise direction). The base material 2 sent out from the spreading roll 12 is wound up by a winding roll (not shown).

  A gravure coating apparatus 1 is disposed on the opposite side of the base material 2 from the spreading rolls 11 and 12 side. A gravure roll (roll member) 13 is in contact with a region of the substrate 2 located between the spreading rolls 11 and 12. The gravure roll 13 is rotatably supported by a support mechanism 14. The stretching rolls 11 and 12 can move in the vertical direction of FIG. 1, and the pressure contact force of the gravure roll 13 with respect to the substrate 2 can be adjusted by adjusting the amount of movement.

  The gravure roll 13 is connected to an actuator via a power transmission mechanism (not shown), and rotates in response to a driving force from the actuator. The gravure roll 13 rotates in the direction opposite to the conveyance direction of the substrate 2 (in other words, the counterclockwise direction in FIG. 1) as indicated by an arrow B2 in FIG. In addition, you may rotate the gravure roll 13 in the same direction as the conveyance direction of the base material 2. FIG.

  A coating agent is supplied to the gravure roll 13 from a coating agent supplier 15. The coating agent supply machine 15 has a concave housing portion (housing member) 15a for housing the coating agent. The accommodating part 15a is formed in the shape (shape with curvature) along the outer periphery of the gravure roll 13, and a part of the gravure roll 13 is located in the accommodating part 15a. Specifically, approximately half of the gravure roll 13 is positioned inside the accommodating portion 15a.

  The container 15 a is connected to a supply source (not shown) of the coating agent via a supply path 15 b provided in the coating agent supply machine 15. Thereby, the coating agent supplied from the supply source is guided to the accommodating portion 15a via the supply path 15b. Here, the coating agent is always supplied from the supply source, and the coating agent supplied to the container 15a leaks from the container 15a as indicated by the dotted line in FIG. It is discharged outside the feeder 15.

  The coating agent is collected by a collection container (not shown) disposed below the coating agent supply machine 15 and returned to the supply source. In this way, the coating agent is circulated through the supply source and the coating agent supply machine 15.

  The configuration for supplying the coating agent to the gravure roll 13 is not limited to the configuration shown in the coating agent supply unit 15. That is, any configuration may be used as long as a storage member that stores the coating agent is provided and the gravure roll 13 is brought into contact with the coating agent in the storage member.

  A doctor blade (blade member) 16 is in pressure contact with the surface of the gravure roll 13. The doctor blade 16 has a function of wiping off an excess coating agent adhering to the surface of the gravure roll 13 and filling the gravure pattern (engraving portion) formed on the surface of the gravure roll 13 with the coating agent substantially evenly. Have.

  The doctor blade 16 is made of a resin such as plastic or rubber and is held by a holder 17. Here, the specific shape of the doctor blade 16 will be described later.

  Next, a specific configuration of the gravure roll 13 will be described with reference to FIG. Here, FIG. 2A is a side view when the gravure roll 13 is viewed from a direction orthogonal to the rotation axis, and FIG. 2B is a cross-sectional view taken along line XX in FIG. is there.

  The gravure roll 13 has an application region 13a in which a gravure pattern (a plurality of grooves) is engraved in the circumferential direction and a non-application region 13b in which the gravure pattern is not engraved in the circumferential direction. A coating agent is held in the gravure pattern formed in the coating region 13a. That is, when the gravure roll 13 rotates, the coating agent adheres to the gravure pattern in the coating region 13a located in the accommodating portion 15a.

  When the gravure roll 13 is further rotated in a state where the coating agent is attached to the coating region 13a, the coating region 13a holding the coating agent comes into contact with the substrate 2, and the coating agent on the coating region 13a is transferred to the substrate 2. The Thereby, application | coating of the coating agent with respect to the base material 2 is performed.

  Here, the outer diameter R1 of the application region 13a is larger than the outer diameter R2 of the non-application region 13b. In addition, each application | coating area | region 13a has a substantially uniform outer diameter in this whole. Each non-application region 13b also has a substantially uniform outer diameter throughout. L in FIG. 2B indicates the length of the gravure roll 13 in the rotation axis direction.

  Further, as shown in FIG. 2 (B), the gravure roll 13 is formed on a roll core 13c formed of a metal such as iron or SUS (stainless steel) having rigidity and toughness, and an outer surface of the roll core 13c. And a ceramic layer 13d having a predetermined thickness. The ceramic layer 13d is formed by plasma spraying ceramic powder (such as chromium oxide) on the outer surface of the roll core 13c. For example, chromium oxide can be used as the ceramic powder. Since chromium oxide has a relatively high Vickers hardness, the wear resistance of the gravure roll 13 can be improved. Moreover, since chromium oxide has a relatively high absorption rate of laser light, it is suitable for forming a gravure pattern using laser irradiation.

  And the gravure pattern is formed in the area | region corresponding to the application | coating area | region 13a among the outer surfaces of the ceramic layer 13d. Specifically, after the ceramic layer 13d is formed on the surface of the roll core 13c, the surface of the ceramic layer 13d is polished and a gravure pattern is formed by laser irradiation. Here, by using the ceramic layer 13d, a gravure pattern can be easily formed by laser irradiation.

The thickness of the ceramic layer 13d can be appropriately set in consideration of wear resistance and the like. Specifically, when the thickness of the ceramic layer 13d is D and the outer diameter of the application region 13a of the gravure roll 13 is R1, it is preferable to satisfy the relationship of the following formula (1).
40.0 ≦ R1 / D ≦ 466.7 (1)

  When the value of R1 / D is larger than the upper limit value of the formula (1), in other words, when the thickness D of the ceramic layer 13d with respect to the outer diameter R1 is too small, the wear resistance of the ceramic layer 13d is insufficient. turn into. Further, when the value of R1 / D is smaller than the lower limit value of the formula (1), in other words, when the thickness D of the ceramic layer 13d with respect to the outer diameter R1 is too large, the ceramic layer 13d is subjected to thermal expansion or stress. The risk of cracking increases.

  Here, as an example in which the value of R1 / D indicates the lower limit value of the formula (1), there is a case where the outer diameter R1 is 20 [mm] and the thickness D is 0.5 [mm]. Moreover, as an example in which the value of R1 / D indicates the upper limit value of the formula (1), there is a case where the outer diameter R1 is 70 [mm] and the thickness D is 0.15 [mm]. The thickness of the ceramic layer 13d is larger than the groove depth of the gravure pattern formed in the application region 13a.

  Moreover, the outer diameter R1 of the application | coating area | region 13a and the outer diameter R2 of the non-application | coating area | region 13b among the gravure rolls 13 can be set suitably. However, if the outer diameter R2 is too small, the strength of the gravure roll 13 is lowered. Therefore, the outer diameter R2 may be set within a range in which the strength can be secured. And outer diameter R1 should just be larger than outer diameter R2. Here, the outer diameter R2 is preferably 0.9 times the outer diameter R1.

Furthermore, it is preferable that the outer diameter R1 satisfies the relationship of the following formula (2) with respect to the total length (length in the rotation axis direction) L of the gravure roll 13.
4.2 ≦ L / R1 ≦ 15.0 (2)

  Here, the total length L of the gravure roll 13 may be the length of the gravure roll 13 itself, or may be the length of the gravure roll 13 in the region inside the both ends supported by the bearings. Good. When the total length L of the gravure roll 13 is 300 [mm], the outer diameter R1 can be set to an arbitrary value within the range of 20 to 70 [mm].

  When the value of L / R1 is larger than the upper limit value of the expression (2), in other words, when the outer diameter R1 is too small with respect to the total length L of the gravure roll 13, the rigidity of the gravure roll 13 decreases, The gravure roll 13 will bend. Moreover, when the value of L / R1 is smaller than the lower limit of Formula (2), in other words, when the outer diameter R1 is too large with respect to the total length L of the gravure roll 13, the gravure roll 13 ( The contact area of the application region 13a) increases. Here, when the surface of the substrate 2 in contact with the gravure roll 13 has an uneven portion (unevenness caused by a manufacturing error), the bead varies depending on the position on the substrate 2. In addition, a bead means the liquid pool of the coating agent formed between the gravure roll 13 and the base material 2. FIG. If the bead varies, the width of the coating film (coating agent film) formed on the substrate 2 may vary as a result, or the coating film may be striped.

  If the outer diameters R1 and R2 are set as described above, the application of the coating agent to the substrate 2 can be stabilized.

  In addition, although a present Example demonstrates the case where three application area | regions 13a are formed in the gravure roll 13, it does not restrict to this. That is, only one application region 13a may be formed, or a plurality of application regions 13a may be formed.

  On the other hand, a cover member 18 having the shape shown in FIG. 3 is disposed in a portion corresponding to the non-application area 13 b in the gravure roll 13. The cover member 18 has a shape with a curvature, and can be formed of Teflon (registered trademark) or the like. The inner peripheral surface 18a of the cover member 18 is formed in a shape along the non-application area 13b of the gravure roll 13, and faces the non-application area 13b. Here, a gap for ensuring the rotation of the gravure roll 13 is formed between the inner peripheral surface 18a of the cover member 18 and the non-application area 13b.

  Further, the outer peripheral surface 18b of the cover member 18 is formed in a shape along the accommodating portion 15a of the coating agent supply machine 15, and is fixed to the accommodating portion 15a. Here, the width of the cover member 18 is substantially equal to the width of the non-application area 13b (length in the rotation axis direction).

  In the state where the cover member 18 is fixed to the storage portion 15a, both end portions 18c and 18d in the circumferential direction of the cover member 18 are interfaced with the coating agent 3 stored in the storage portion 15a (in other words, in other words, as shown in FIG. (Liquid level) It is located above 3a. Thereby, the cover member 18 prevents the coating agent 3 from adhering to the non-application area 13 b of the gravure roll 13. FIG. 4 is a schematic diagram illustrating the configuration of the gravure roll 13, the cover member 18, and the coating agent 3 that are located inside the accommodating portion 15 a.

  Next, a specific shape of the doctor blade 16 will be described with reference to FIG. Here, FIG. 5 is a front view of the doctor blade 16.

  A cut portion 16a is formed at a position corresponding to the end portion (edge) of the application region 13a at the end portion of the doctor blade 16 that contacts the surface of the gravure roll 13. The cut portion 16a may be formed in the doctor blade 16 in advance, or may be formed using frictional force with the gravure roll 13 as described below.

  First, a doctor blade 16 having no notch 16a is prepared, and one end of the doctor blade 16 is brought into pressure contact with the outer surface of the gravure roll 13 (application region 13a). Then, by rotating the gravure roll 13, the cut portion 16 a can be formed in the doctor blade 16 by the frictional force with the edge of the application region 13 a. In this embodiment, since the doctor blade 16 is made of resin, the cut portion 16a can be easily formed by the ceramic layer 13d of the gravure roll 13.

  Moreover, if the notch part 16a is formed by the frictional force with the gravure roll 13, the notch part 16a can be accurately formed at a position corresponding to the edge of the application region 13a.

  When the doctor blade 16 having the above-described configuration is bent and brought into pressure contact with the outer peripheral surface of the gravure roll 13, a portion of the doctor blade 16 corresponding to the application region 13a is in pressure contact with the application region 13a. Further, the cut portion 16a of the doctor blade 16 contacts the side wall surface 13e located between the application region 13a and the non-application region 13b in the gravure roll 13. Thereby, the coating agent adhering to the side wall surface 13e can be wiped off by the cut portion 16a of the doctor blade 16.

  Here, when the gravure coating is performed on the base material 2 while the coating agent is attached to the side wall surface 13e, the side wall surface of the coating film 30 formed on the base material 2 as shown in FIG. The thickness corresponding to 13e (in other words, the end in the width direction of the coating layer 30) 30a may be the largest. And when the base material 2 on which the coating film 30 having a non-uniform thickness is formed is taken up by a take-up roll, the thickness at the end 30a of the coating film 30 gradually increases. Excessive load.

  On the other hand, according to the present embodiment, as described above, since the coating agent attached to the side wall surface 13e of the gravure roll 13 can be wiped off by the cut portion 16a of the doctor blade 16, the coating applied on the substrate 2 is performed. The thickness of the film 30 can be made substantially uniform. For this reason, even if the base material 2 coated with the coating film 30 is wound, the diameter of the wound base material 2 can be prevented from being partially different, and the coating film 30 causes an excessive load on the base material 2. There is no need to spend any money.

  In the present embodiment, the gravure roll 13 can be prevented from being worn by forming the surface of the gravure roll 13 with the ceramic layer 13d and forming the doctor blade 16 with a resin material.

  In addition, by configuring the surface of the gravure roll 13 with the ceramic layer 13d, it is possible to prevent the surface of the gravure roll 13 from being easily scraped by the particles of the coating agent when the coating agent contains particles. it can. For example, when the gravure roll 13 having the chrome plating applied to the surface of the core portion made of iron is used, the surface of the gravure roll 13 (chrome plating) may be scraped by particles contained in the coating agent. is there. In this case, the shape of the gravure pattern formed in the application region 13a of the gravure roll 13 changes, and the amount of the coating agent applied to the substrate 2 also changes. In this embodiment, by forming the ceramic layer 13d on the surface of the gravure roll 13, it is possible to suppress the surface of the gravure roll 13 from being scraped by particles contained in the coating agent, and the abrasion resistance of the gravure roll 13. Can be improved. In addition, by suppressing the wear of the gravure roll 13, it is possible to prevent the wear powder from being mixed into the coating film applied to the substrate 2.

  Furthermore, by using the gravure coating apparatus of the present embodiment, variations in the width and thickness of the coating film can be suppressed as compared with a coating apparatus using a die head. In this embodiment, since it is not necessary to use a masking tape as in the prior art, there is no coating agent adhering to the masking tape, and the coating agent can be used without waste. Thereby, manufacturing cost can be reduced.

  Next, a modification of the present embodiment will be described with reference to FIG. Here, FIG. 7 is a diagram showing a configuration around the gravure roll. In this modification, the cover member 18 described in the above embodiment is omitted. Hereinafter, this modification will be specifically described. In addition, about the member which has the same function as the member demonstrated in the Example mentioned above, the same code | symbol is used and detailed description is abbreviate | omitted.

  In this modification, the application region 13a of the gravure roll 13 is brought into contact with the coating agent 3 accommodated in the accommodating portion 15a, and the non-application region 13b is not brought into contact with the coating agent 3. That is, the non-application area 13 b is located at a position away from the interface (liquid level) of the application agent 3. Here, on the side wall surface 13 e located at the boundary between the application region 13 a and the non-application region 13 b, a part of the region is in contact with the coating agent 3.

  According to the configuration described above, it is possible to prevent the coating agent 3 from adhering to the non-application region 13b without using the cover member 18 described in the first embodiment. On the other hand, also in this modification, the doctor blade 16 described in the first embodiment is used. And also in this modification, the same effect as the Example mentioned above can be acquired.

By using the gravure coating apparatus according to the above-described embodiments and modifications, for example, an electrode (a positive electrode or a negative electrode) of a secondary battery can be manufactured. Examples of the secondary battery include a nickel-hydrogen battery and a lithium ion battery. Here, for example, when manufacturing an electrode (negative electrode) of a lithium ion battery, carbon (graphite) as a coating agent can be applied to the current collector (copper foil) as the base material 2. . In addition, in order to prevent an internal short circuit with respect to the negative electrode of this configuration, when an inorganic oxide layer is formed on the carbon, the inorganic oxide is applied to the carbon by using a gravure coating device. can do. Examples of the inorganic oxide include Al ₂ O ₃ , MgO, and SiO ₂ .

  In the gravure coating apparatus according to the embodiment and the modification described above, the gravure pattern formed in the application region 13a of the gravure roll 13 can be configured as shown in FIG. Here, FIG. 8 is an enlarged view of a part of the application region 13a.

  In the application region 13a, a plurality of groove portions 13a1 arranged side by side in the rotation axis direction of the gravure roll 13 (left and right direction in FIG. 8) are formed. Each groove portion 13 a 1 extends in a direction inclined with respect to the rotation axis of the gravure roll 13. The plurality of groove portions 13a1 extend in the same direction.

  Moreover, each groove part 13a1 is comprised by one continuous curved surface. Specifically, each groove part 13a1 is formed in the shape along the one part area | region in the outer peripheral surface of a cylindrical body. Here, the cylindrical body has a cross-sectional shape orthogonal to the longitudinal direction formed in a circular shape, an elliptical shape, or a shape substantially equivalent to these shapes. In addition, the curvature (or curvature radius) in each groove part 13a1 can be set suitably.

  By configuring the groove 13a1 with the curved surface shown in FIG. 8, the amount of the coating agent applied to the substrate 2 can be stabilized. Here, when the groove 13a2 is formed as shown in FIG. 9, there is a possibility that the coating agent is clogged in a part of the groove 13a2. That is, in the configuration shown in FIG. 9, since the bottom of the groove 13a2 has an acute angle, the coating agent may remain attached to the bottom of the groove 13a2. For example, when the above-described inorganic oxide is used as the coating agent, the inorganic oxide particles may clog the bottom of the groove 13a2. In such a case, in the groove portion 13a2, the volume capable of holding the coating agent decreases, and the amount of the coating agent applied to the substrate 2 decreases.

  On the other hand, in the structure shown in FIG. 8, since the groove part 13a1 is comprised by the continuous curved surface, it can suppress that a coating agent gets blocked. Thereby, all of the coating agent retained in the groove 13a1 can be transferred to the substrate 2. And since the quantity of the coating agent apply | coated to the base material 2 does not vary, a fixed amount of coating agent can be apply | coated to the base material 2 continuously.

  Moreover, the gravure pattern formed in the application | coating area | region 13a of the gravure roll 13 can be comprised as shown in FIG. Here, FIG. 10A is a schematic diagram showing the application region 13a, and FIG. 10B is a diagram showing the state of the coating film applied to the substrate 2. FIG.

  In the configuration shown in FIG. 10A, a plurality of groove portions 13a1 constituting a gravure pattern are formed so as to extend in two different directions. That is, it has the groove part 13a1 extended in the 1st direction D1 inclined with respect to the rotating shaft of the gravure roll 13, and the groove part 13a1 extended in the 2nd direction D2 different from the 1st direction D1. As shown in FIG. 10A, the first and second directions D1 and D2 intersect each other. In FIG. 10A, the ridge line of each groove 13a1 is shown so that the extending direction of each groove 13a1 can be easily understood, and does not represent the actual shape of the application region 13a.

  Here, the shape of each groove part 13a1 is the same as the shape shown in FIG. 8, and is comprised by the continuous curved surface. Further, the first direction D1 and the second direction D2 can be set as appropriate. For example, the first and second directions D1 and D2 can be in a line symmetric or plane symmetric relationship. In addition, the angles (acute angles) formed by the rotation axis direction of the gravure roll 13 and the first and second directions D1 and D2 can be different from each other.

  10A, the coating film 31 having a substantially uniform thickness can be formed on the substrate 2 as shown in FIG.

  Here, as shown in FIG. 11A, when each groove 13a1 is formed so as to extend in only one direction, the coating agent held in the groove 13a1 is subjected to the action of gravity or the like, and the groove 13a1. It will move in the direction of extending. That is, there is a possibility that the coating agent held in the groove 13a1 may be shifted to one end side of the coating region 13a. If a coating agent is applied to the substrate 2 in such a state, a coating film 32 having different thicknesses at both ends may be formed as shown in FIG. In other words, in the coating film 32, the thickness of one end becomes thicker than the thickness of the other end.

  As shown in FIG. 11B, if the regions having different thicknesses in the coating film 32 are cut, the coating film 32 having a substantially uniform thickness can be obtained, but the cut portion is wasted. End up.

  On the other hand, in the configuration shown in FIG. 10A, since the plurality of groove portions 13a1 extend in a direction intersecting with each other, it is possible to prevent the coating agent accommodated in each groove portion 13a1 from being offset. That is, since the coating agent can be dispersed in a plurality of directions (first and second directions D1 and D2) in the coating region 13a, the coating agent can be prevented from being offset. In such a state, when a coating agent is applied to the substrate 2, a coating film 31 having a substantially uniform thickness can be obtained. In this case, as shown in FIG. 11B, it is not necessary to cut the base material on which the coating film is formed, and waste of the coating agent and the base material can be eliminated.

Moreover, it is preferable that the number (so-called number of lines) N of the groove portions 13a1 formed in the application region 13a satisfy the following formula (3). Here, the number N of lines indicates the number of grooves 13a1 per inch on the surface of the application region 13a.
85 ≦ N ≦ 200 (3)

  When the number N of lines is smaller than 85, the area of the bank portion (portion other than the groove portion) formed between the adjacent groove portions 13a1 becomes too large, and a continuous coating film is formed on the base material 2. It becomes impossible to do. That is, a coating film having a pattern corresponding to the plurality of groove portions 13a1 is formed on the substrate 2.

  When the number N of lines is larger than 200, the width of each groove 13a1 becomes too narrow. And when a coating agent contains particle | grains, the particle | grains contained in a coating agent become difficult to adhere to each groove part 13a1, and it may become impossible to apply | coat the particle | grains of a coating agent to the base material 2. FIG. .

Furthermore, the volume V of the groove 13a1 formed in the application region 13a preferably satisfies the following formula (4).
4 ≦ V ≦ 60 (4)

Here, the volume V is a volume [cm ³ / m ² ] per square mail on the surface of the application region 13a. Further, the volume V is a value that depends on the number N of lines when the depth (groove depth) of the groove 13a1 is constant. Here, the depth of the groove 13a1 can be set to a value in the range of 30 to 130 [μm].

  On the other hand, the edge of the application region 13a in the gravure roll 13 preferably has an angle of 90 degrees. In addition, when the edge has a curvature, the radius of curvature is preferably set to 0.1 [mm] or less.

  As described above, by forming the edge of the coating region 13a, it is possible to suppress variation in the thickness of the end portion in the width direction of the coating film. That is, in the case where the edge of the application region 13a has a curvature, when the radius of curvature is larger than 0.1 [mm], the amount of the coating agent adhering to the edge in the application region 13a is reduced to other portions. May be larger than the amount of coating agent omitted. If the coating agent is applied to the substrate 2 in such a state, the end in the width direction of the coating film protrudes from the other portions, and a coating film having a substantially uniform thickness cannot be obtained. .

It is the schematic of the gravure coating apparatus which is Example 1 of this invention. It is the side view (A) and sectional drawing (B) of a gravure roll. It is an external appearance perspective view of a cover member. It is a figure which shows the positional relationship of a gravure roll and a cover member. It is the schematic which shows the structure of a doctor blade. It is the schematic which shows the coating film formed on the base material by the conventional gravure coating. It is the schematic which shows the structure of a part of gravure coating apparatus which is a modification of Example 1. FIG. It is the elements on larger scale in the application | coating area | region of a gravure roll. It is the elements on larger scale in the application | coating area | region of a gravure roll. It is the schematic (A) which shows the structure of the gravure pattern in an application area | region, and sectional drawing (B) of the base material in which the coating film was formed. It is the schematic (A) which shows the structure of the gravure pattern in an application area | region, and sectional drawing (B) of the base material in which the coating film was formed.

Explanation of symbols

1: gravure coating device 2: base material 13: gravure roll 13a: coating region 13b: non-coating region 13c: roll core 13d: ceramic layer 15: coating agent supplier 15a: container 16: doctor blade

Claims (10)

A housing member for housing the coating agent;
A roll member for applying a coating agent to an object to be coated by a rotating operation;
In the rotation axis direction, the roll member is
An application region in which a plurality of grooves for holding the coating agent are formed in the circumferential direction;
A coating apparatus having a diameter smaller than the diameter of the coating area and having a non-coating area in a non-contact state with the coating agent accommodated in the housing member. A blade member that contacts the roll member and adjusts the amount of coating agent adhered to the roll member;
The coating apparatus according to claim 1, wherein the blade member has a cut portion at a position corresponding to a boundary between the application region and the non-application region in the roll member. The blade member is made of resin,
The coating device according to claim 2, wherein the cut portion is formed using a frictional force with the roll member.   It has a cover member provided in the position corresponding to the non-application area | region of the said roll member, and prevents adhesion of the coating agent with respect to the said non-application | coating area | region. Coating device.   5. The coating apparatus according to claim 1, wherein at least a surface layer portion of the roll member is formed of a ceramic material.   6. The coating apparatus according to claim 5, wherein the roll member has a surface layer portion made of chromium oxide and a core portion made of stainless steel.   The coating apparatus according to claim 1, wherein the roll member includes a plurality of the coating area and the non-coating area in the rotation axis direction.   The coating apparatus according to claim 1, wherein the object to be coated and the coating agent are materials constituting electrodes of a secondary battery.   Each said groove part is comprised by the curved surface, The coating device as described in any one of Claim 1 to 8 characterized by the above-mentioned.   10. The coating apparatus according to claim 1, wherein the plurality of groove portions include first and second groove portions extending in a direction intersecting with each other.

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