Attachment for coating

Abstract

NOT VISIBLE DUE TO STATUS OF PATENT

Description

Coating attachment

[0001] The present invention relates to a coating attachment used for applying a coating liquid to the inner walls of flow channels of a honeycomb substrate by a suction method.

[0002] An exhaust gas purification catalyst device for purifying exhaust gas emitted from an internal combustion engine of an automobile or the like has a configuration in which, for example, a catalyst coating layer containing an exhaust gas purification catalyst is applied to the inner walls of the flow paths of a honeycomb substrate.

[0003] Known methods for manufacturing such exhaust gas purification catalytic devices include, for example, a method that includes a coating step using a "suction method" (Patent Documents 1 to 3). The "suction method" involves placing a coating liquid for forming a catalyst coating layer on one end face of a honeycomb substrate and suctioning it from the opposite end face, causing the placed coating liquid to spread into the flow channels of the honeycomb substrate.

[0004] JP 2007-268484 A JP 2015-039672 A JP 2006-015205 A

[0005] When applying a coating liquid to the flow channels of a honeycomb substrate by suction, the coating liquid may adhere to part of the outer skin of the honeycomb substrate. The catalytic components, such as catalytic precious metals, contained in the coating liquid adhered to the outer skin of the honeycomb substrate do not contribute to purifying exhaust gases. Therefore, when applying the coating liquid, adhesion of the coating liquid to part of the outer skin of the honeycomb substrate leads to a loss of catalytic components.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coating attachment for suppressing adhesion of a coating liquid to a part of the outer skin of a honeycomb substrate when the coating liquid is applied to the inner walls of the flow channels of the honeycomb substrate by a suction method.

[0007] The present invention is as follows.

[0008] <<Aspect 1>> A coating attachment for applying a coating liquid to the inner walls of a flow path of a honeycomb substrate by a suction method, the coating attachment having a generally cylindrical shape with a first open end at one end and a second open end at the other end, a coating liquid storage section at the first open end, and a substrate abutment section for abutting against the outer peripheral edge of the end of the honeycomb substrate on the second open end side of the coating liquid storage section, the substrate abutment section having a tapered surface whose inner diameter increases toward the second open end side. <Aspect 2> The coating attachment according to Aspect 1, comprising, on the second open end side of the substrate abutting portion, a connecting portion coaxially surrounding the honeycomb substrate, and a substrate fixing portion for coaxially surrounding the honeycomb substrate and fixing the honeycomb substrate, in this order, and the connecting portion has an opening for connecting a region of the outer surface of the honeycomb substrate near the substrate abutting portion to outside air. <Aspect 3> The coating attachment according to Aspect 2, wherein the opening of the connecting portion extends in the circumferential direction of the connecting portion. <Aspect 4> The coating attachment according to Aspect 3, wherein the opening of the connecting portion extends around the entire circumference of the connecting portion. <Aspect 5> The coating attachment according to Aspect 4, wherein a portion of the connecting portion closer to the first open end than the opening and a portion closer to the second open end than the opening are connected by a plurality of columnar portions located within the opening and spaced apart from each other in the circumferential direction of the connecting portion. <Aspect 6> The coating attachment according to Aspect 5, wherein the cross-sectional shape of the columnar portion cut in a direction perpendicular to the axial direction of the coating attachment is circular, elliptical, polygonal, or arc-shaped. <Aspect 7> The coating attachment according to any one of Aspects 2 to 6, wherein the substrate fixing portion has a balloon-shaped member for pressing against the outer peripheral surface of the honeycomb substrate to fix it. <Aspect 8> The coating attachment according to any one of Aspects 1 to 7, wherein the substrate abutting portion is made of an elastic material. <Aspect 9> The coating attachment according to any one of Aspects 1 to 8, wherein the angle formed between the tapered surface of the substrate abutting portion and the axis of the coating attachment is 35° or more and 70° or less.Aspect 10: The coating attachment according to any one of Aspects 1 to 9, wherein the coating liquid storage section has a shape in which the inner diameter increases toward the first open end.

[0009] According to the coating attachment of the present invention, when a coating liquid is applied to the inner walls of the flow channels of a honeycomb substrate by a suction method, adhesion of the coating liquid to a part of the outer skin of the honeycomb substrate is suppressed.

[0010] Fig. 1 is a schematic cross-sectional view showing an example of the configuration of a coating attachment of the present invention. Fig. 2 is a schematic cross-sectional view showing the coating attachment of Fig. 1 attached to a honeycomb substrate. Fig. 3 is a schematic cross-sectional view showing another example of the configuration of a coating attachment of the present invention. Fig. 4 is a schematic cross-sectional view showing the coating attachment of Fig. 3 attached to a honeycomb substrate. Fig. 5 is a perspective view of the coating attachment of Fig. 3.

[0011] <<Coating Attachment>> The coating attachment of the present invention is a coating attachment for applying a coating liquid to the inner walls of a flow path of a honeycomb substrate by a suction method, and has a generally cylindrical shape with a first open end at one end and a second open end at the other end, a coating liquid storage section at the first open end, and a substrate abutting section for abutting against the outer peripheral edge of the end of the honeycomb substrate on the second open end side of the coating liquid storage section, and the substrate abutting section has a tapered surface whose inner diameter increases toward the second open end side.

[0012] The coating attachment of the present invention may further have, in this order, a connecting portion that coaxially surrounds the honeycomb substrate and is located closer to the second opening end than the substrate abutment portion, and a substrate fixing portion that coaxially surrounds the honeycomb substrate and fixes the honeycomb substrate.

[0013] In this case, the connecting portion may have an opening for communicating the region of the outer peripheral surface of the honeycomb substrate near the substrate abutting portion with the outside air.

[0014] The coating attachment of the present invention has a substrate contact portion for contacting the outer peripheral edge of the end of the honeycomb substrate, which has a tapered surface, thereby preventing the coating liquid from adhering to part of the outer skin of the honeycomb substrate.

[0015] In the prior art, when a coating liquid is applied to the inner walls of the flow channels of a honeycomb substrate by a suction method, the coating liquid adheres to part of the outer skin of the honeycomb substrate for the following two main reasons.

[0016] First, when the coating attachment is placed on the upper end surface of the honeycomb substrate, the adhesion between the substrate contact portion and the honeycomb substrate is poor, which may cause the coating liquid to leak from the contact portion during suction.

[0017] Secondly, when using one coating attachment to continuously apply coating liquid to multiple honeycomb substrates, it is possible that the coating liquid remaining on the substrate contact portion will adhere to part of the outer skin of the next honeycomb substrate.

[0018] In this regard, since the coating attachment of the present invention has a tapered surface at the substrate contact portion, when placed on the upper end face of the honeycomb substrate, it is believed that the substrate contact portion and the honeycomb substrate are in close contact with each other, and leakage of the coating liquid from the contact portion is suppressed.Furthermore, since the coating attachment of the present invention has a tapered surface at the substrate contact portion and has a small contact area with the honeycomb substrate, it is believed that even if there is coating liquid remaining on the substrate contact portion, it is unlikely to adhere to part of the outer skin of the honeycomb substrate.

[0019] Furthermore, when the coating attachment of the present invention has a connecting portion and a substrate fixing portion on the second opening end side (lower side) of the substrate abutment portion, and the connecting portion has an opening for connecting the area of ​​the outer surface of the honeycomb substrate near the substrate abutment portion to the outside air, even if there is a small gap at the contact portion between the substrate abutment portion and the honeycomb substrate during suction, an airflow will be generated in the direction of the coating liquid storage portion, which is thought to highly suppress leakage of the coating liquid from the abutment portion.

[0020] It is believed that the combination of the above features of the coating attachment of the present invention significantly inhibits adhesion of the coating liquid to a portion of the outer skin of the honeycomb substrate during coating. However, the present invention is not limited to any particular theory.

[0021] The components of the coating attachment of the present invention will be described below in order.

[0022] <General Shape> The coating attachment of the present invention has a generally cylindrical shape with a first open end at one end and a second open end at the other end.

[0023] The coating attachment of the present invention is used to apply a coating liquid to the inner walls of the flow channels of a honeycomb substrate by a suction method. During coating, the honeycomb substrate is placed or fixed so that its axial direction is approximately parallel to the vertical direction. The coating attachment of the present invention is placed on the upper end face of the honeycomb substrate in this state, with the first open end facing upward and the second open end facing downward. Specifically, it is envisioned that the coating attachment of the present invention will be placed so that the tapered surface of the substrate contact portion abuts against the outer peripheral edge of the upper end face of the honeycomb substrate.

[0024] Therefore, the coating attachment of the present invention has a generally cylindrical shape that is advantageous for use by placing it on the end face of the honeycomb substrate.

[0025] Hereinafter, in this specification, the direction toward the first opening end of the coating attachment may be referred to as the "upward direction" or "upper side," and the direction toward the second opening end may be referred to as the "downward direction" or "lower side."

[0026] <Coating Liquid Storage Portion> The coating liquid storage portion in the coating attachment of the present invention is a portion for storing the coating liquid prior to suction when the coating liquid is applied to the inner walls of the flow channels of the honeycomb substrate by suction.

[0027] When the coating attachment of the present invention is placed on the end face of the honeycomb substrate, it becomes possible to store a coating liquid in a space defined by the end face of the honeycomb substrate, the inner wall of the portion extending from the substrate contact portion to the first open end, and the surface to which the first open end belongs. Therefore, the coating liquid storage portion may have any shape.

[0028] The coating liquid storage section may have a shape in which the inner diameter increases toward the first open end (upper side), which has the advantage of being able to store a large amount of coating liquid and being easy to clean after use.

[0029] The capacity of the coating liquid reservoir may be set appropriately depending on the planned coating amount.

[0030] The coating liquid reservoir may be made of a material appropriately selected by a person skilled in the art. For example, the coating liquid reservoir may be made of a synthetic resin, a metal, a ceramic, or the like. The entire coating liquid reservoir may be made of the same material, or may be made by combining multiple portions made of different materials.

[0031] <Substrate Contacting Portion> The coating attachment of the present invention has a substrate contacting portion for contacting the outer periphery of the end portion of the honeycomb substrate, located closer to the second open end (lower side) than the coating liquid reservoir portion.

[0032] The inside of this substrate contacting portion is a tapered surface whose inner diameter increases toward the second open end (lower side). Therefore, the uppermost part of the substrate contacting portion (the part of the substrate contacting portion closest to the first open end) is the part of the substrate contacting portion with the smallest inner diameter.

[0033] The substrate contact portion may be formed contiguous with the lowermost portion of the coating liquid storage portion (the portion of the coating liquid storage portion closest to the second open end). In this case, the uppermost portion of the substrate contact portion may coincide with the lowermost portion of the coating liquid storage portion and may be the portion with the smallest inner diameter in the coating liquid attachment of the present invention.

[0034] The angle between the tapered surface of the substrate contacting portion and the axis of the coating attachment may be, for example, 30° or more and 75° or less. From the viewpoint of ensuring fixation of the honeycomb substrate during coating, this angle may be, for example, 35° or more, 40° or more, 45° or more, or 50° or more, and from the viewpoint of suppressing uncoated flow paths near the outer peripheral edge of the honeycomb substrate, the angle may be, for example, 70° or less, 65° or less, 60° or less, or 55° or less.

[0035] The coating attachment of the present invention has a substrate contact portion having a tapered surface whose inner diameter increases toward the second open end (lower side), so that when the coating attachment is placed on the honeycomb substrate, the diameter of the tapered surface closest to the first open end (uppermost part) is smaller than the outer diameter of the honeycomb substrate.

[0036] In this case, the "protrusion width," defined as the difference between the radius of the honeycomb substrate and the radius of the top of the tapered surface, may be set in consideration of the balance between coating efficiency and the effects of the present invention. This "protrusion width" may be, for example, 0.3 mm or more, 0.5 mm or more, or 0.7 mm or more, and may be, for example, 2.0 mm or less, 1.8 mm or less, 1.5 mm or less, or 1.3 mm or less.

[0037] The inside (tapered surface) of the substrate contacting portion may be made of an elastic material. By making the tapered surface of the substrate contacting portion from an elastic material, the adhesiveness of the portion where the tapered surface of the substrate contacting portion and the honeycomb substrate contact each other is improved, and leakage of the coating liquid from that portion is suppressed. This suppresses adhesion of the coating liquid to a portion of the outer skin of the honeycomb substrate.

[0038] The elastic material that forms the tapered surface of the substrate contacting portion may be one or more types selected from, for example, silicone rubber, fluororubber, and the like.

[0039] The material constituting the portion of the substrate contacting portion other than the tapered surface may be made of a highly rigid material that can maintain the shape of the substrate contacting portion, such as a synthetic resin or a metal.

[0040] The substrate contact portion in the present invention may be, for example, made of a highly rigid material and may have a cylindrical portion with a tapered inner surface on which a layer of elastic material is formed.

[0041] <Connecting Portion> As described above, the coating attachment of the present invention has a coating liquid storage portion and a substrate contact portion.

[0042] In addition to the coating liquid storage section and the substrate abutting section, the coating attachment of the present invention may further have, in this order, a connecting section that coaxially surrounds the honeycomb substrate and is located closer to the second open end than the substrate abutting section, and a substrate fixing section that coaxially surrounds the honeycomb substrate and fixes the honeycomb substrate.

[0043] The connecting portion in the coating attachment of the present invention has a structure that coaxially surrounds the honeycomb substrate, and may have an opening that allows the region of the outer peripheral surface of the honeycomb substrate near the substrate contact portion to communicate with the outside air.

[0044] The advantages of the connection part having an opening will be explained below using an example in which the pressure around the coating attachment is atmospheric pressure. However, the pressure around the coating attachment of the present invention is not limited to atmospheric pressure, and the coating attachment may be used under pressurized or reduced pressure.

[0045] When the coating attachment of the present invention does not have a connecting portion or a substrate fixing portion, when the coating attachment is placed on the upper end face of a honeycomb substrate, the region of the honeycomb substrate's outer surface near the substrate contact portion is naturally in contact with the outside air. Therefore, when coating liquid is stored in the coating liquid storage portion of the coating attachment placed on one end face of the honeycomb substrate and suction is performed from the opposite end face of the honeycomb substrate, the pressure in the region of the honeycomb substrate's outer surface near the substrate contact portion is atmospheric pressure, but because the coating liquid stored in the coating liquid storage portion is being suctioned, the pressure becomes lower than atmospheric pressure. Therefore, with this type of coating attachment, leakage of the coating liquid from the substrate contact portion is less likely to occur.

[0046] Next, consider a case where the coating attachment has a connecting portion and a substrate fixing portion. The honeycomb substrate to which the coating attachment of the present invention is applied may be made of ceramics having pores penetrating the partition walls. In this case, if the coating liquid is stored in the coating liquid storage portion of the coating attachment and suction is applied from the opposite end face of the honeycomb substrate, it is thought that air on the outer peripheral surface side of the honeycomb substrate will be sucked through the pores penetrating the partition walls, causing the pressure on the outer peripheral surface side of the honeycomb substrate to become lower than atmospheric pressure. In this case, there is a concern that the coating liquid stored in the coating liquid storage portion will leak beyond the substrate abutment portion into the reduced pressure region and adhere to the outer skin of the honeycomb substrate.

[0047] However, if the connecting portion has an opening for connecting the region of the outer peripheral surface of the honeycomb substrate near the substrate abutment portion to the outside air, even if the coating liquid is stored in the coating liquid storage portion of the coating attachment and suction is applied from the opposite end face of the honeycomb substrate, outside air flows in through the opening, and the air pressure in the region of the honeycomb substrate near the substrate abutment portion is maintained at atmospheric pressure. Therefore, during suction, the coating liquid stored in the coating liquid storage portion is prevented from leaking beyond the substrate abutment portion and onto the outer peripheral surface of the honeycomb substrate, preventing the coating liquid from adhering to the outer skin of the honeycomb substrate.

[0048] The openings of the connecting portions may extend in the circumferential direction of the connecting portions. In this case, the openings may extend discontinuously around the entire circumference of the connecting portions, or may extend continuously around the entire circumference of the connecting portions. If the openings of the connecting portions extend continuously around the entire circumference of the connecting portions, this is preferable in that air pressure in the region near the substrate abutment portion of the honeycomb substrate can be smoothly adjusted.

[0049] The width of the opening of the connecting portion (the axial opening width of the coating attachment) may be set appropriately taking into consideration the intended degree of suction, the effectiveness of maintaining the air pressure in the area near the substrate abutment portion of the honeycomb substrate at atmospheric pressure, and the size of the coating attachment.

[0050] Such an opening may be formed, for example, by dividing the connecting portion into a portion closer to the first opening end than the opening (an upper portion) and a portion closer to the second opening end than the opening (a lower portion), and connecting the two portions with a columnar portion. In this case, there may be a plurality of columnar portions, and these columnar portions may be present inside the opening at intervals in the circumferential direction of the connecting portion. Here, if each columnar portion is configured to be entirely located inside the outer periphery of the connecting portion (closer to the axis of the coating attachment), the opening of the connecting portion can be configured to extend continuously around the entire periphery of the connecting portion.

[0051] The cross-sectional shape of the columnar portion cut in a direction perpendicular to the axial direction of the coating attachment may be, for example, a circle, an ellipse, a polygon, an arc, or a combination thereof.

[0052] The material constituting the connecting portion may be a highly rigid material capable of maintaining the shape of the connecting portion. The material constituting the portion of the substrate abutment portion other than the tapered surface may be, for example, a synthetic resin, a metal, or the like. The material constituting the columnar portion may be the same as or different from the material constituting the connecting portion. The columnar portion may be a component separate from the other portions of the connecting portion, or may be integrally formed with the other portions of the connecting portion.

[0053] <Substrate Fixing Section> The substrate fixing section in the coating attachment of the present invention has the function of coaxially surrounding the honeycomb substrate and fixing the honeycomb substrate. To perform this function, the substrate fixing section may include a substrate fixing section main body that coaxially surrounds the honeycomb substrate and supports the coating liquid storage section, the substrate abutment section, and the connecting section, and a balloon-shaped member that presses against the outer peripheral surface of the honeycomb substrate to fix it.

[0054] In order to effectively perform its supporting function, the substrate fixing part main body may have a flange part at the second open end of the coating attachment for fixing the coating attachment to a coating device, a coating table, etc. The substrate fixing part main body, including the flange part if present, may be made of a highly rigid member.

[0055] The balloon-shaped member may be configured, for example, such that its upper and lower ends are fixed between the substrate fixing body parts, and its middle part forms a gap between itself and the substrate fixing body part. According to this embodiment, air pressure, water pressure, or oil pressure can be applied to the gap between the middle part of the balloon-shaped member and the substrate fixing body part to expand the balloon-shaped member toward the center, thereby pressing and fixing the outer peripheral surface of the honeycomb substrate.

[0056] The material constituting the substrate fixing portion body may be made of a highly rigid material capable of maintaining its shape and fixing the honeycomb substrate. The material constituting this portion may be, for example, a synthetic resin, a metal, or the like. The balloon-shaped member may be made of an elastic material to exert its function of pressing against the outer peripheral surface of the honeycomb substrate and fixing it. The balloon-shaped member may be, for example, neoprene rubber, NBR, natural rubber, or the like.

[0057] <<Coating Method>> According to another aspect of the present invention, there is provided a method for coating a honeycomb substrate using the coating attachment of the present invention.

[0058] The method for coating a honeycomb substrate of the present invention includes the steps of attaching the coating attachment of the present invention to one end face of the honeycomb substrate (coating attachment attachment step), placing and storing a coating liquid in the coating liquid storage section of the coating attachment (coating liquid storage step), and sucking the coating liquid from the opposite end face of the honeycomb substrate (suction step).

[0059] In the coating attachment mounting step, the coating attachment is mounted on one end face of the honeycomb substrate so that the tapered surface of the substrate contacting portion contacts the outer peripheral edge of one end face of the honeycomb substrate. Here, the "overhang width," defined as half the difference between the diameter of the honeycomb substrate and the inner diameter of the top of the tapered surface of the substrate contacting portion (the portion of the substrate contacting portion with the smallest inner diameter), is preferably larger from the viewpoint of preventing leakage of the coating liquid from the contacting portion, and is preferably smaller from the viewpoint of improving the efficiency of supplying the coating liquid to the flow passages near the outer periphery of the honeycomb substrate. The "overhang width" may be appropriately set by a person skilled in the art, taking the above factors into consideration.

[0060] In the coating liquid storage step, the coating liquid is placed and stored in the coating liquid storage portion of the coating attachment. The viscosity and amount of the coating liquid may be appropriately determined by a person skilled in the art depending on the size of the honeycomb substrate and the desired coating length (the percentage of the substrate length to be coated).

[0061] In the suction step, the coating liquid is sucked from the opposite end face of the honeycomb substrate. The degree and time of this suction may be appropriately set by those skilled in the art depending on the viscosity and amount of the coating liquid.

[0062] The coated honeycomb substrate can be dried and fired by a known method to form, for example, an exhaust gas purification catalyst device.

[0063] <<Specific Embodiments>> Hereinafter, examples of the configuration of the coating attachment of the present invention will be described with reference to the drawings.

[0064] FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a coating attachment of the present invention.

[0065] The coating attachment (100) of FIG. 1 has a generally cylindrical shape and a first opening (A １１ ) is opened at the lower end, and a second opening (A １２ ) is open.

[0066] The coating attachment (100) has a first open end (A １１ ) side, and the coating liquid storage section (110) is located closer to the second opening end (A １２ ) side has a substrate contact portion (120).

[0067] The coating liquid storage section (110) extends from the boundary with the substrate contact section (120) to the first open end (A １１ ) side (upper side), the same inner diameter is maintained for a while, but further １１ ) side, the inner diameter increases.

[0068] The substrate contacting portion (120) is formed continuously with the lowest part of the coating liquid storage portion (110), and the inside thereof is formed with a second opening end (A １２) side, the inner diameter becomes larger as it becomes a tapered surface (121).

[0069] FIG. 2 is a schematic cross-sectional view showing the state in which the coating attachment (100) shown in FIG. 1 is mounted on a honeycomb substrate (300).

[0070] In FIG. 2, the tapered surface (121) of the substrate contact portion (120) is shown contacting the outer peripheral edge of one end face of the honeycomb substrate (300). １ ") is the diameter (d ３００ ) and the inner diameter (d １２０ ) is defined as half the difference between

[0071] 1 and 2, when placed on the upper end surface of the honeycomb substrate 300, the area of ​​the outer peripheral surface of the honeycomb substrate 300 near the substrate contact portion 120 is always in contact with the outside air. Therefore, when coating is performed by the suction method using the coating attachment 100, the pressure in the area of ​​the outer peripheral surface of the honeycomb substrate 300 near the substrate contact portion is maintained at atmospheric pressure and is not reduced, so that leakage of the coating liquid from the substrate contact portion 120 is unlikely to occur.

[0072] The coating attachment (200) of FIG. 3 has a generally cylindrical shape and a first opening (A ２１ ) is opened at the lower end, and a second opening (A ２２ ) is open.

[0073] The coating attachment (200) has a first open end (A ２１ ) side, and the coating liquid storage section (210) is located closer to the second opening end (A ２２ ) side, and further, the second opening end (A ２２ ) side, it has a connecting portion (230) and a substrate fixing portion (240).

[0074] The configurations of the coating liquid storage section (210) and the substrate contact section (220) of the coating attachment (200) are similar to those of the coating liquid storage section (110) and the substrate contact section (120) of the coating attachment (100) shown in Figures 1 and 2, and the substrate contact section (220) has a tapered surface (221).

[0075] The connecting portion (230) coaxially surrounds the honeycomb substrate and has the function of connecting the substrate abutting portion (220) and a substrate fixing portion (240) described below.

[0076] The connecting portion (230) of the coating attachment (200) is divided into an upper connecting portion portion (230a) on the first opening end side (upper side) and a lower connecting portion portion (230b) on the second opening end side (lower side), and the gap between them forms an opening portion (231). The upper connecting portion portion (230a) and the lower connecting portion portion (230b) are connected by a plurality of columnar portions (230c). These columnar portions (230c) are arranged inside the opening portion (231) at intervals from each other in the circumferential direction of the connecting portion (230), and are all located inside the outer periphery of the connecting portion (230) (closer to the axis of the coating attachment (200)). Due to this arrangement of the multiple columnar portions (230c), the opening (231) of the gap between the upper connecting portion (230a) and the lower connecting portion (230b) extends continuously around the entire circumference of the connecting portion (230).

[0077] The substrate fixing portion (240) has a function of coaxially surrounding the honeycomb substrate and fixing the honeycomb substrate.

[0078] The substrate fixing part (240) of the coating attachment (200) has a substrate fixing part main body (241) and a balloon-shaped member (242), and further has a flange part (243).

[0079] The substrate fixing part main body (241) of the substrate fixing part (240) has the function of providing strength to the substrate fixing part (240) and the coating attachment (200) and holding the entire coating attachment (200) in place so that it can achieve its intended purpose.

[0080] The balloon-shaped member (242) is made of an elastic member, and when air pressure, water pressure, or oil pressure is applied between it and the substrate fixing portion main body (241), it expands toward the center of the coating attachment (200) and presses against the outer surface of the honeycomb substrate to fix it.

[0081] In the coating attachment (200), the balloon-shaped member (242) is configured so that its upper end is sandwiched between the connecting portion upper part (230a) and the substrate fixing portion main body (241), its lower end is sandwiched between the flange part (243), and they are fixed together, and a gap can be formed between the middle part and the substrate fixing portion main body (241). Also, in the coating attachment (200), the upper end of the balloon-shaped member (242) constitutes part of the connecting portion lower part (230b). Such an embodiment is also included in the present invention.

[0082] The flange portion (243) may be used to secure the coating attachment (200) to a coating device, a coating table, etc. (neither of which are shown).

[0083] 4 shows the state in which the tapered surface (221) of the substrate contact portion (220) is in contact with the outer peripheral edge of one end face of the honeycomb substrate (300). Here, the balloon-shaped member (242) of the coating attachment (200) is shown expanding toward the center of the coating attachment (200) to press and fix the outer peripheral surface of the honeycomb substrate (300).

[0084] Also, "protrusion width (p ２ ") is the diameter (d ３００ ) and the inner diameter (d ２２０ ) is defined as half the difference between

[0085] FIG. 5 shows a perspective view of the coating attachment (200).

[0086] When the coating attachment (200) shown in Figures 3 to 5 is placed on the upper end surface of the honeycomb substrate (300), the outer peripheral surface of the honeycomb substrate (300) is surrounded by a connecting portion (230) and a substrate fixing portion (240). However, the connecting portion (230) has an opening (231) that extends continuously around its entire circumference. Therefore, when coating is performed by the suction method using the coating attachment (200), outside air flows in through the opening (231), and the pressure in the region of the outer peripheral surface of the honeycomb substrate (300) near the substrate abutment portion is maintained at atmospheric pressure and is unlikely to be reduced, thereby suppressing leakage of the coating liquid from the substrate abutment portion (220).

[0087] Examples 1 to 3 and Comparative Examples 1 and 2 Coating tests were carried out using a coating attachment having the general shape shown in Figure 2. The coating attachments used in each of the Examples and Comparative Examples were attachments with the angle (taper angle) between the tapered surface of the substrate-contacting portion and the axis of the coating attachment, and with or without an opening in the connecting portion, as shown in Table 1.

[0088] The materials constituting each part of the coating attachment used in the examples are as follows: Coating liquid storage part: polyethylene resin Substrate contact part Part other than tapered surface: polyethylene resin Tapered surface: silicone rubber sheet attached Substrate fixing part Part other than flange: polyethylene resin Flange: stainless steel Balloon-shaped member: neoprene rubber

[0089] The opening of the connecting portion in Examples 1 to 3 extended continuously around the entire circumference of the connecting portion, and the width of the opening (opening width in the axial direction of the coating attachment) was 1 mm. The "protrusion width," defined as half the difference between the diameter of the honeycomb substrate and the inner diameter of the uppermost part of the tapered surface of the substrate contact portion, was 1.0 mm.

[0090] The coating test was carried out by applying 80 g of coating liquid to a cylindrical cordierite honeycomb substrate having a diameter of 80 mm and a length of 65 mm by a suction method, and the presence or absence of uncoated flow paths and the amount of coating liquid (dry mass) attached to the outer skin of the honeycomb substrate were examined. Here, the coating test was carried out multiple times in succession, with the substrate being replaced with a new one in succession, and the average value of the multiple times was used as the amount of coating liquid attached to the outer skin.

[0091] The coating liquid used in the coating test was a slurry coating liquid for forming a catalyst coating layer of an exhaust gas purification catalyst device, and had the following viscosity at 25°C: shear rate 383 s －１ Viscosity at shear rate: 180 mPa·s, shear rate: 3.83 s －１ Viscosity at: 5,000 mPa·s

[0092] The results are shown in Table 1.

[0093]

[0094] Referring to Table 1, the following can be seen:

[0095] In the coating tests of Comparative Examples 1 and 2, in which a coating attachment with no opening in the connecting portion was used, there were no uncoated flow paths, but the amount of coating liquid adhering to the outer shell was large.

[0096] In contrast, in the coating tests of Examples 1 to 3, in which a coating attachment having a tapered substrate contact portion and an opening at the connecting portion was used, only a few or no uncoated flow paths were left uncoated, and the amount of coating liquid attached to the outer skin was small. In Example 3, some of the flow paths near the outer periphery of the honeycomb substrate were uncoated, but this was not to the extent that it would cause a practical problem.

[0097] These coating tests verified that the coating attachment of the present invention achieves the intended purpose.

[0098] DESCRIPTION OF SYMBOLS 100, 200 Coating attachment 110, 210 Coating liquid storage section 120, 220 Substrate contact section 121, 221 Tapered surface 230 Connecting section 230a Connecting section upper section 230b Connecting section lower section 230c Pillar-shaped section 231 Opening 240 Substrate fixing section 241 Substrate fixing section main body 242 Balloon-shaped member 243 Flange section 300 Honeycomb substrate A １１ , A ２１ First opening A １２ , A ２２ Second opening d １２０ , d ２２０ Inner diameter of the top of the tapered surface d ３００ Diameter of honeycomb substrate p １ , p ２ Overhang width

Claims

1. A coating attachment for coating a coating liquid on the inner wall of a flow path of a honeycomb substrate by a suction method, having a substantially cylindrical shape with a first opening end opening at one end and a second opening end opening at the other end, having a coating liquid reservoir at the first opening end, and having a substrate contact portion for contacting the outer peripheral edge of the end of the honeycomb substrate on the second opening end side of the coating liquid reservoir, wherein the substrate contact portion has a tapered surface whose inner diameter expands as it goes to the second opening end side. Coating attachment.

2. On the second opening end side of the substrate contact portion, in this order, a connecting portion that coaxially surrounds the honeycomb substrate and a substrate fixing portion for fixing the honeycomb substrate coaxially surrounding the honeycomb substrate, and the connecting portion has an opening for communicating a region near the substrate contact portion of the outer peripheral surface of the honeycomb substrate with the outside air. The coating attachment according to claim 1.

3. The coating attachment according to claim 2, wherein the opening of the connecting portion extends in the circumferential direction of the connecting portion.

4. The coating attachment according to claim 3, wherein the opening of the connecting portion extends over the entire circumference of the connecting portion.

5. A portion of the connecting portion on the first opening end side of the opening and a portion of the connecting portion on the second opening end side of the opening are connected to each other in the circumferential direction of the connecting portion by a plurality of columnar portions spaced apart from each other inside the opening. The coating attachment according to claim 4.

6. The coating attachment according to claim 5, wherein a cross-sectional shape obtained by cutting the columnar portion in a direction perpendicular to the axial direction of the coating attachment is circular, elliptical, polygonal, or arc-shaped.

7. The coating attachment according to any one of claims 2 to 6, wherein the substrate fixing portion has a balloon-shaped member for pressing and fixing the outer peripheral surface of the honeycomb substrate.

8. The coating attachment according to any one of claims 1 to 7, wherein the substrate contact portion is made of an elastic material.

9. The coating attachment according to any one of claims 1 to 8, wherein an angle formed by the tapered surface of the substrate contact portion and the axis of the coating attachment is 35° or more and 70° or less.

10. The coating liquid storage part has a shape in which the inner diameter expands as it goes toward the first opening end side. The coating attachment according to any one of claims 1 to 9.