Slot-type spray nozzle

Abstract

A slot-type spray nozzle according to one aspect of the present invention is provided with: a plurality of application liquid discharge ports arranged at intervals across the width direction thereof; a plurality of first gas discharge ports and second gas discharge ports disposed sandwiching the application liquid discharge ports to form pairs therewith and arranged at intervals across the width direction; and a first gas flow path and a second gas flow path each connecting from inside the nozzle to the first gas discharge ports and the second gas discharge ports, respectively. A surface where these discharge ports are present serves as a discharge surface, and the orientation in which the application liquid discharge ports are sandwiched between the first gas discharge ports and the second gas discharge ports serves as the nozzle thickness direction. As viewed along the nozzle thickness direction, the first center line and the second center line at the centers of the respective inner wall surfaces of the first gas discharge ports and the second gas discharge ports that sandwich the application liquid discharge ports to form pairs therewith intersect the discharge surface at inclinations in mutually opposite directions relative to a line perpendicular to the discharge surface passing through the center of the application liquid discharge ports.

Description

Slotted Spray Nozzle

[0001] The present invention relates to a slot-type spray nozzle.

[0002] As a device for applying a coating liquid to a substrate, a spray coating device is known which converts the coating liquid into droplets using a spray nozzle (hereinafter also simply referred to as "nozzle") and then sprays the droplets. Spray coating devices generally use one-fluid spray nozzles which convert the coating liquid into droplets using only liquid pressure, or two-fluid spray nozzles which discharge pressurized gas simultaneously with the coating liquid and atomize and spray the coating liquid using the impact force of the discharged gas.

[0003] In this spray coating device, from the viewpoint of substrate productivity and functionality, it is often required to form a thin film of uniform thickness over substantially the entire surface of a wide substrate. As a spray nozzle suitable for such a case, for example, Patent Document 1 discloses a slot-type spray nozzle having multiple coating liquid outlets extending across the coating width of the substrate and a pair of gas outlets that open continuously or intermittently across the width near the coating liquid outlets and are arranged to sandwich the coating liquid outlets. In this spray nozzle, the coating liquid outlets and gas outlets are formed by combining four nozzle blocks and at least one shim plate, and fine coating droplets can be generated by colliding high-speed gas with the coating liquid discharged from the coating liquid outlets. Furthermore, slot-type spray nozzles can be arranged with multiple coating liquid outlets in the width direction at very narrow intervals of approximately 5 mm to 20 mm. In such slot-type spray nozzles, arranging multiple small coating liquid outlets allows for more precise control of the coating liquid discharge rate than a configuration in which a continuous coating liquid outlet is provided across the entire width, making it effective for thin-film coating. Furthermore, by arranging these coating liquid discharge ports at narrow intervals, the coating liquid can be applied with a uniform distribution in the width direction.

[0004] Furthermore, Patent Document 2 discloses a nozzle for liquid adhesive filaments, which comprises a pair of nozzle blocks and a shim plate stack consisting of five shim plates interposed between the nozzle blocks, and which are fastened together with fixing bolts to form a nozzle. This shim plate stacked nozzle has a coating liquid outlet and a gas outlet with structures similar to those of the nozzle described in Patent Document 1, and is therefore also applicable to spray atomization.

[0005] JP 2006-026576 A JP 2008-212919 A

[0006] In order to achieve uniform coating in the width direction using a spray nozzle such as those disclosed in Patent Documents 1 and 2, it is necessary to maintain a certain distance between the nozzle outlet and the substrate so that the fine droplets sprayed in stripes from the coating liquid outlets arranged in the width direction are sufficiently dispersed and continuously distributed across the entire width of the nozzle. On the other hand, the greater this distance, the more likely it is that the fine droplets will evaporate during flight or disperse into the surrounding space, resulting in a decrease in the amount of droplets adhering to the target and a decrease in the efficiency of use of the coating liquid. It is also possible to reduce the arrangement pitch of the coating liquid outlets to achieve a continuous distribution in the width direction over a short spray distance. However, in this case, the total number of gas outlets increases, leading to an increase in the amount of gas discharged, which increases the amount of dispersal into the surrounding space and again reduces the efficiency of use of the coating liquid.

[0007] The present invention has been made in view of the above-mentioned problems, and has as its object to provide a slot-type spray nozzle that can form a continuous, uniform thin film in the width direction even when the distance to the target to be sprayed is short.

[0008] In order to solve the above problems and achieve the object, the present invention has the configuration described in any one of [1] to [7] below.

[0009] The slot type spray nozzle according to the present invention is [1] a slot type spray nozzle extending in a width direction, comprising: a plurality of coating liquid discharge ports arranged at intervals across the width direction; a plurality of first gas discharge ports and a plurality of second gas discharge ports arranged in pairs on either side of the coating liquid discharge port and spaced apart across the width direction; a first gas flow path connecting from the inside of the slot type spray nozzle to the first gas discharge port; and a second gas flow path connecting from the inside of the slot type spray nozzle to the second gas discharge port, The surface on which the second gas discharge port is present is defined as a discharge surface, the direction in which the coating liquid discharge port is sandwiched between the first gas discharge port and the second gas discharge port is defined as a nozzle thickness direction, and in the view of the arrows in the nozzle thickness direction, a first center line and a second center line taken through the centers of both inner wall surfaces of the first gas flow path and the second gas flow path connected to the first gas discharge port and the second gas discharge port, respectively, which are a pair sandwiching the coating liquid discharge port, intersect the discharge surface at inclinations in opposite directions to each other with respect to a perpendicular to the discharge surface that passes through the center of the coating liquid discharge port.

[0010] The slot type spray nozzle according to the present invention is characterized in that, in the invention described in [1] above, the first center line and the second center line intersect inside the slot type spray nozzle when viewed along an arrow in the nozzle thickness direction.

[0011] [3] The slot type spray nozzle according to the present invention is the invention described in [1] or [2] above, characterized in that, when viewed along an arrow in the nozzle thickness direction, the ratio of the widthwise length of an overlapping portion of the first gas outlet and the second gas outlet, which are a pair sandwiching the coating liquid outlet, to the widthwise lengths of the first gas outlet and the second gas outlet is 0.3 or more and 0.6 or less, and the angle formed by each of the first center line and the second center line and the outlet surface is 50 degrees or more and 60 degrees or less.

[0012] Furthermore, the slot type spray nozzle according to the present invention is characterized in that, in the invention described in any one of [1] to [3] above, the coating liquid discharge port is composed of a plurality of coating liquid discharge small nozzles arranged at intervals in the width direction, and when viewed with an arrow in the nozzle thickness direction, the plurality of coating liquid discharge small nozzles are arranged in positions that are symmetrical with respect to a line perpendicular to the discharge surface that passes through a point where the first center line and the second center line intersect.

[0013] The slot type spray nozzle according to the present invention is [5] a slot type spray nozzle extending in the width direction, comprising: a plurality of coating liquid discharge ports arranged at intervals in the width direction; a plurality of first gas discharge ports and a plurality of second gas discharge ports arranged in pairs on either side of the coating liquid discharge ports and arranged at intervals in the width direction; a first gas flow path connecting from the inside of the slot type spray nozzle to the first gas discharge port; and a second gas flow path connecting from the inside of the slot type spray nozzle to the second gas discharge port. a surface on which the coating liquid discharge port, the first gas discharge port, and the second gas discharge port are present is defined as a discharge surface; a direction in which the coating liquid discharge port is sandwiched between the first gas discharge port and the second gas discharge port is defined as a nozzle thickness direction; and when viewed along an arrow in the nozzle thickness direction, both inner wall surfaces of the first gas flow path and the second gas flow path connected to the first gas discharge port and the second gas discharge port, which are paired on either side of the coating liquid discharge port, are inclined in a manner such that they move away from the coating liquid discharge port as they approach the discharge surface.

[0014] [6] The slot type spray nozzle according to the present invention is characterized in that, in the invention described in [5] above, when viewed with an arrow in the nozzle thickness direction, a first center line taken through the centers of both inner wall surfaces of the first gas flow path and a second center line taken through the centers of both inner wall surfaces of the second gas flow path are located on opposite sides of a perpendicular line to the discharge surface that passes through the center of the coating liquid discharge port.

[0015] [7] The slot type spray nozzle according to the present invention is the invention described in [5] or [6] above, characterized in that, when viewed along the arrow in the nozzle thickness direction, the ratio of the widthwise length of the overlapping portion of the first gas outlet and the second gas outlet, which are a pair sandwiching the coating liquid outlet, to the widthwise lengths of the first gas outlet and the second gas outlet is 0.3 or less.

[0016] The present invention has the effect of providing a slot-type spray nozzle that improves diffusibility in the width direction by discharging gas having a velocity component in the width direction, and is capable of forming a uniform coating film even when the nozzle is close to the target to be sprayed.

[0017] FIG. 1 is a perspective view showing a schematic configuration of a slot-type spray nozzle according to a first embodiment of the present invention and a coating state. FIG. 2 is a view facing the cross-sectional hatched portion of the slot-type spray nozzle shown in FIG. 1. FIG. 3 is a discharge surface view of the slot-type spray nozzle according to the first embodiment of the present invention, viewed from the coating liquid discharge port side. FIG. 4 is a plan view of the shim plate stack of the slot-type spray nozzle according to the first embodiment of the present invention, viewed in the stacking direction from the nozzle block side. FIG. 5 is an enlarged view of the gas flow path portion of the slot-type spray nozzle shown in FIG. 4. FIG. 6 is a schematic diagram showing how sprayed fine droplets spread in the gas flow path shape shown in FIG. 5. FIG. 7 is an enlarged view of the gas flow path shown in FIG. 6, viewed from the discharge surface side. FIG. 8 is a schematic diagram showing how sprayed fine droplets spread in a conventional slot-type spray nozzle. FIG. 9 is a diagram illustrating a preferred gas flow path configuration of the slot-type spray nozzle according to the first embodiment of the present invention. FIG. 10 is a view of a set of flow paths in the shim plate stack constituting the gas flow path shown in FIG. 9, viewed from the discharge surface side. FIG. 11 is a diagram defining a gas discharge angle in a curved gas flow path. FIG. 12 is a diagram illustrating the configuration of a coating liquid flow path having a plurality of coating liquid discharge small orifices. FIG. 13A is a diagram illustrating a first example of a coating liquid flow path having a plurality of coating liquid discharge small orifices, other than that shown in FIG. 12. FIG. 13B is a diagram illustrating a second example of a coating liquid flow path having a plurality of coating liquid discharge small orifices, other than that shown in FIG. 12. FIG. 14 is an exploded perspective view illustrating the structure of a slot-type spray nozzle according to a first embodiment of the present invention. FIG. 15 is a schematic diagram illustrating how sprayed fine droplets spread in a slot-type spray nozzle according to a second embodiment of the present invention. FIG. 16 is an enlarged view of the slot-type spray nozzle shown in FIG. 15, viewed from the discharge surface side. FIG. 17 is a diagram illustrating a more preferable gas flow path configuration in a slot-type spray nozzle according to the second embodiment of the present invention. FIG. 18 is a diagram illustrating a configuration for an example of a slot-type spray nozzle according to the present invention. FIG. 19 is a diagram illustrating evaluation criteria for the examples. FIG. 20 is a diagram illustrating a distribution state in which the spray droplets are thin in the center and thick at the ends in the diffusion of the spray droplets.

[0018] As a result of extensive research into the above-mentioned problems, the inventors discovered that by tilting a gas flow path, which was previously configured so that the discharged pressurized gas traveled straight ahead perpendicular to the nozzle width direction, in the nozzle width direction, the velocity component of the pressurized gas in the width direction can be increased, which can be used to solve the above-mentioned problems, leading to the present invention. Because the pressurized gas is discharged along an inclined gas flow path, it has a velocity component in the width direction depending on the magnitude of the inclination. By colliding such pressurized gas with the coating liquid discharged from the nozzle tip, the fine droplets of the coating liquid can be made to fly with sufficient velocity components not only perpendicular to the nozzle outlet but also in the nozzle width direction, thereby increasing the spray width of the coating liquid per coating liquid outlet. As a result, the sprayed fine droplets have a continuous distribution in the nozzle width direction over a short flight distance, thereby shortening the distance between the nozzle outlet and the target to be sprayed and improving the use efficiency of the coating liquid.

[0019] The gas constituents of the pressurized gas used in the present invention are not limited, and nitrogen gas, etc. can be used in addition to air. The coating liquid used for spray coating is also not particularly limited, and examples thereof include solutions of inorganic or organic substances, or slurries in which inorganic or organic substances are dispersed in a binder and a solvent. The viscosity of the coating liquid must be low enough to allow the coating liquid to be atomized by the discharged gas, and generally, it is preferable that the viscosity be 500 mPas or less.

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following description is provided to facilitate understanding of the present invention and is not intended to limit the present invention in any way. The scope of the present invention is not limited to the embodiments described below, but includes all modifications within the scope of equivalents to the configurations described in the claims.

[0021] [Embodiment 1] Fig. 1 is a perspective view showing a schematic configuration of a slot type spray nozzle according to embodiment 1 of the present invention and a coating state. Fig. 2 is a view facing the cross-sectional hatched portion of the slot type spray nozzle shown in Fig. 1.

[0022] As shown in Figure 1, the spray nozzle 10 is a slot-type spray nozzle (an example of a slot-type spray nozzle according to the first embodiment of the present invention) extending in its width direction, and includes a pair of nozzle blocks 11a, 11b and a shim plate stack 12. In this spray nozzle 10, as shown in Figure 1, the pair of nozzle blocks 11a, 11b and the shim plate stack 12 disposed therebetween are stacked, and these nozzle blocks 11a, 11b and the shim plate stack 12 are fastened together by a plurality of fixing bolts 16 arranged in the width direction of the spray nozzle 10. The spray nozzle 10 is configured in this manner. In the present invention, the width direction refers to the direction in which the spray nozzle 10 extends. Hereinafter, the term "width direction" refers to the width direction of the spray nozzle 10, unless otherwise specified.

[0023] 2 , the shim plate stack 12 is a stack composed of a first gas shim plate 13 a, a second gas shim plate 13 b, a first partition shim plate 14 a, a second partition shim plate 14 b, and a coating liquid shim plate 15. More specifically, in the shim plate stack 12, the coating liquid shim plate 15 is interposed between the first partition shim plate 14 a and the second partition shim plate 14 b, and these three plates are interposed between the first gas shim plate 13 a and the second gas shim plate 13 b. For example, the shim plate stack 12 is composed of the first gas shim plate 13 a, the first partition shim plate 14 a, the coating liquid shim plate 15, the second partition shim plate 14 b, and the second gas shim plate 13 b stacked in this order.

[0024] 1, the spray nozzle 10 (for example, the nozzle block 11a) is provided with a coating liquid supply port 30 at the center in the width direction of the spray nozzle 10. A coating liquid manifold 31 communicating with the coating liquid supply port 30 is provided inside the spray nozzle 10. The coating liquid is supplied to the coating liquid manifold 31 from a coating liquid supply system (not shown) through the coating liquid supply port 30, and is spread uniformly in the width direction by the coating liquid manifold 31.

[0025] 1 , a nozzle block 11a forming the front surface of the spray nozzle 10 is provided with a gas supply port 20a at the center of the width of the spray nozzle 10. A nozzle block 11b forming the back surface of the spray nozzle 10 is provided with a gas supply port 20b at the center of the width of the spray nozzle 10. Gas manifolds 21a and 21b communicating with the gas supply ports 20a and 20b, respectively, are provided inside the spray nozzle 10. Pressurized gas (gas discharged from the spray nozzle 10) is supplied from a pressurized gas source (not shown) through the gas supply port 20a to the gas manifold 21a and through the gas supply port 20b to the gas manifold 21b. The pressurized gas supplied in this manner is uniformly expanded in the width direction by each of the gas manifolds 21a and 21b.

[0026] 2, the spray nozzle 10 has a coating liquid discharge port 33 for discharging the coating liquid, and a coating liquid flow path 32 that connects the interior of the spray nozzle 10 to the coating liquid discharge port 33. The spray nozzle 10 also has a first gas discharge port 23a and a second gas discharge port 23b for discharging a gas, a first gas flow path 22a that connects the interior of the spray nozzle 10 to the first gas discharge port 23a, and a second gas flow path 22b that connects the interior of the spray nozzle 10 to the second gas discharge port 23b. The coating liquid expanded in the width direction by the coating liquid manifold 31 passes through the coating liquid flow path 32 formed by the first partition shim plate 14a, the second partition shim plate 14b, and the coating liquid shim plate 15, as shown in FIG. 2, and is discharged from the coating liquid discharge port 33. The pressurized gas expanded in the width direction by the gas manifold 21a passes through the first gas flow path 22a formed by the nozzle block 11a, the first gas shim plate 13a, and the first partition shim plate 14a, and is discharged at high speed from the first gas discharge port 23a. Similarly, the pressurized gas expanded in the width direction by the gas manifold 21b passes through the second gas flow path 22b formed by the nozzle block 11b, the second gas shim plate 13b, and the second partition shim plate 14b, and is discharged at high speed from the second gas discharge port 23b. The coating liquid discharged from the coating liquid discharge port 33 is sandwiched between the gas discharged at high speed (discharged gas), and forms a group of fine droplets 42 that fly in the gas discharge direction as shown in FIG. 2 and adhere to the substrate 40 being transported, thereby forming a coating film 41.

[0027] The material of the components constituting the spray nozzle 10 is not particularly limited, and from the viewpoint of processing precision and durability, a metal material, particularly a stainless steel material, can be used.

[0028] FIG. 3 is a discharge surface view of the slot-type spray nozzle according to the first embodiment of the present invention, as viewed from the coating liquid discharge port side. As shown in FIG. 3, a plurality of coating liquid discharge ports 33 of the spray nozzle 10 are arranged at intervals across the width of the spray nozzle 10. Specifically, on the discharge surface 17 (i.e., the nozzle tip) of the spray nozzle 10 shown in FIG. 3, the coating liquid discharge ports 33 have rectangular opening ends. As shown in FIG. 3, a plurality of such coating liquid discharge ports 33 are arranged at equal intervals across the width of the spray nozzle 10 at a pitch P so that the overall width of the arrangement of the coating liquid discharge ports 33 of the spray nozzle 10 is a spray width W3. As shown in FIG. 3, the first gas discharge port 23a and the second gas discharge port 23b of the spray nozzle 10 are arranged in pairs on either side of the coating liquid discharge port 33, and a plurality of the first gas discharge ports 23a and the second gas discharge ports 23b are arranged at intervals across the width of the spray nozzle 10. In detail, a pair of slit-shaped gas outlets, the first gas outlet 23a and the second gas outlet 23b, each having a gas outlet width W2, are arranged in the width direction at the same pitch P as the coating liquid outlet 33 so as to sandwich the coating liquid outlet 33 near the coating liquid outlet 33.

[0029] The optimum width W1 of each coating liquid discharge port 33 (hereinafter referred to as the coating liquid discharge width W1) varies depending on the viscosity of the coating liquid used and the flow rate of the coating liquid being discharged, but is preferably 100 μm or more from the viewpoint of minimizing processing variations in the shape of each coating liquid discharge port. Furthermore, in order to apply an appropriate internal pressure within the coating liquid manifold 31 and uniformly distribute the coating liquid from the coating liquid manifold 31 to each coating liquid discharge port 33, it is preferable that the upper limit of the coating liquid discharge width W1 be 400 μm or less. Furthermore, for the same reasons as for the coating liquid discharge width W1, the thickness of the coating liquid discharge port 33, i.e., the thickness of the coating liquid shim plate 15, is also preferably 200 μm or less. The arrangement pitch P of the coating liquid discharge ports 33 is preferably as narrow as possible from the viewpoint of the uniformity of the coating film in the width direction, and specifically, is preferably 20 mm or less.

[0030] The gas discharge width W2 is the width of each of the first gas discharge port 23a and the second gas discharge port 23b (the length in the width direction of the spray nozzle 10). The gas discharge width W2 is preferably longer than the coating liquid discharge width W1 so that the coating liquid discharged from each coating liquid discharge port 33 can be stably atomized by the discharged gas. The thickness of each of the first gas discharge port 23a and the second gas discharge port 23b is the thickness of each of the first gas shim plates 13a and the second gas shim plates 13b. From the viewpoint of increasing the velocity of the discharged gas to atomize the coating liquid, the thickness is preferably 100 μm or less, and more preferably 50 μm or less.

[0031] Furthermore, the closer the first gas discharge port 23a and the second gas discharge port 23b are to the coating liquid discharge port 33, the more quickly the gas discharged from each of the first gas discharge port 23a and the second gas discharge port 23b can collide with the coating liquid from the coating liquid discharge port 33. For this reason, the thickness of each of the first partition shim plate 14a and the second partition shim plate 14b is preferably 100 μm or less, and more preferably 50 μm or less.

[0032] FIG. 4 is a plan view of the shim plate stack of the slot-type spray nozzle according to the first embodiment of the present invention, viewed from the nozzle block in the stacking direction. FIG. 4 illustrates the flight of the coating liquid sprayed from the spray nozzle 10 when the shim plate stack 12 is viewed from the nozzle block 11a. As shown in FIG. 4, the coating liquid discharged from the coating liquid discharge port 33 becomes fine droplets 42, which fly while expanding in the width direction of the spray nozzle 10 due to the width vectors of the gas discharged from each of the first gas discharge port 23a and the second gas discharge port 23b and the effect of turbulent diffusion. After flying a certain distance d, the droplets 42 intersect with adjacent droplets discharged from adjacent coating liquid discharge ports 33 in the width direction, thereby forming droplets having a continuous distribution in the width direction. When these droplets 42 are sprayed onto a substrate 40, a uniform coating film 41 is formed on the substrate 40.

[0033] Figure 5 is an enlarged view of the gas flow path portion of the slot-type spray nozzle shown in Figure 4. Figure 5 shows an arrow view of the gas flow path portion of the above-mentioned spray nozzle 10 as viewed from the nozzle thickness direction. In the present invention, the nozzle thickness direction is a direction in which the coating liquid discharge port 33 of the spray nozzle 10 is sandwiched between the first gas discharge port 23a and the second gas discharge port 23b, as shown in Figures 2 and 3. In other words, this nozzle thickness direction is the same as the stacking direction of the shim plate stack 12 (shim plate stacking direction). As shown in Figure 5, the first gas flow path 22a is formed by first gas flow path inner wall surfaces 24aL and 24aR, which are both inclined inner walls that constitute the gas flow path when viewed from the nozzle thickness direction. Furthermore, as shown by the dashed line in Figure 5, the second gas flow path 22b is located at the rear side of the first gas flow path 22a (at the rear side of the paper in Figure 5), and similar to the first gas flow path 22a, is composed of second gas flow path inner wall surfaces 24bL, 24bR, which are both inner walls that are inclined when viewed from the arrow in the nozzle thickness direction.

[0034] 5, a first center line 25a and a second center line 25b are set for the first gas discharge port 23a and the second gas discharge port 23b, respectively. The first center line 25a and the second center line 25b are lines taken through the centers of the inner wall surfaces of the first gas discharge port 23a and the second gas discharge port 23b, which are paired on either side of the coating liquid discharge port 33 as described above, when viewed from the arrow in the nozzle thickness direction. That is, the first center line 25a and the second center line 25b are lines including a locus obtained by continuously taking points equidistant from the inner wall surfaces of the first gas flow path 22a and the second gas flow path 22b from the gas manifold 21 to the discharge surface 17, and are lines obtained by extending the locus from the discharge surface 17 in the discharge direction. As described above, the discharge surface 17 is the nozzle tip of the spray nozzle 10, and is the surface on which the coating liquid discharge port 33, the first gas discharge port 23a, and the second gas discharge port 23b are located (see FIGS. 2 and 3 ). As shown in FIG. 5 , the acute angle at which the first center line 25a intersects with the discharge surface 17 in the nozzle thickness direction is defined as the first gas discharge angle θa, and the acute angle at which the second center line 25b intersects with the discharge surface 17 is defined as the second gas discharge angle θb. The first gas discharge angle θa is the angle of inclination of the first gas flow path 22a with respect to the discharge surface 17. The second gas discharge angle θb is the angle of inclination of the second gas flow path 22b with respect to the discharge surface 17.

[0035] The first center line 25a and the second center line 25b defined as described above intersect with the discharge surface 17 at inclinations in opposite directions relative to a perpendicular line to the discharge surface 17 passing through the center of the coating liquid discharge port 33 when viewed from the arrow in the nozzle thickness direction. Furthermore, in the first embodiment, the first center line 25a and the second center line 25b intersect with each other near the discharge surface 17, as shown in FIG. 5 . Furthermore, the smaller the first gas discharge angle θa and the second gas discharge angle θb described above, the more sufficient the widthwise velocity component of the discharged gas can be obtained. This achieves a diffusion effect of the fine droplets (droplet group 42 shown in FIG. 4 ) that are formed by atomizing the coating liquid from the coating liquid discharge port 33. On the other hand, when the first gas discharge angle θa and the second gas discharge angle θb are 45 degrees or greater, the linear component of the discharged gas can be sufficiently secured. This reduces the atomization of the fine droplets. From the viewpoint of maintaining the straightness of the fine droplets, it is preferable that the pair of gas ejection angles, the first gas ejection angle θa and the second gas ejection angle θb, be the same angle. However, in the present invention, the first gas ejection angle θa and the second gas ejection angle θb do not necessarily have to be the same angle.

[0036] Fig. 6 is a schematic diagram showing how sprayed fine droplets spread in the gas flow path shape shown in Fig. 5. Fig. 7 is an enlarged view of the gas flow path shown in Fig. 6 as viewed from the discharge surface side. Fig. 8 is a schematic diagram showing how sprayed fine droplets spread in a conventional slot type spray nozzle. Fig. 8 illustrates various aspects of the coating liquid flow path and gas flow path in a conventional slot type spray nozzle for comparison with the slot type spray nozzle (spray nozzle 10) according to embodiment 1 of the present invention.

[0037] In FIG. 6 , the solid arrow 26a indicates the direction of the gas (hereinafter, sometimes referred to as the first discharged gas) discharged from the discharge port (first gas discharge port 23a) of the first gas flow path 22a. The dashed arrow 26b indicates the direction of the gas (hereinafter, sometimes referred to as the second discharged gas) discharged from the discharge port (second gas discharge port 23b) of the second gas flow path 22b. The gas discharged from the first gas discharge port 23a is discharged at a discharge angle that follows the inclination of the first gas flow path 22a around the coating liquid flow path 32. The gas discharged from the second gas discharge port 23b is discharged at a discharge angle that follows the inclination of the second gas flow path 22b around the coating liquid flow path 32. As shown in FIG. 6 , the gases discharged from the first gas discharge port 23a and the second gas discharge port 23b are discharged at angles that are opposite to each other, i.e., with widthwise velocity components that are opposite to each other. Therefore, as shown in FIG. 7, the coating liquid discharged from the coating liquid discharge port 33 is sandwiched in the shim plate stacking direction between gases facing in opposite width directions. Then, the fine droplets (droplet group 42 shown in FIG. 6) generated by the collision of the first discharged gas and the second discharged gas with the coating liquid discharged from the coating liquid discharge port 33 ride on these gas flows, allowing the fine droplets to be diffused over a wide area in both width directions. Furthermore, as shown in FIG. 7, since there is no discharged gas without a width direction component in the first discharged gas and the second discharged gas, a high width direction diffusion effect of the fine droplets is obtained. Note that the first discharged gas and the second discharged gas eventually lose their width direction velocity component due to friction with each other. Therefore, the straightness of the fine droplets relative to the substrate to be coated is not impaired, and it is possible to suppress the dispersion of the fine droplets in the width direction.

[0038] In the conventional slot-type spray nozzle shown in Figure 8, the gas flow paths (first gas flow path 22a and second gas flow path 22b in Figure 8) were parallel to the coating liquid flow path 32. For this reason, the gas that passed through the gas flow paths and was discharged from the gas outlets (first gas outlet 23a and second gas outlet 23b in Figure 8) did not have a widthwise velocity component. Due to the effect of turbulent diffusion, the gas near the wall surface of the gas flow path spreads slightly in the widthwise direction after being discharged from the gas outlet. However, with the gas flow path shape in the conventional slot-type spray nozzle, the effect of diffusing the discharged gas in the widthwise direction is small.

[0039] In the embodiment of the slot-type spray nozzle according to the present invention described above, a single first gas flow path 22a connects the gas manifold 21a to one first gas outlet 23a, and a single second gas flow path 22b connects the gas manifold 21b to one second gas outlet 23b. However, the first gas flow path 22a (second gas flow path 22b) does not have to be a single path along the entire length of the flow path. It is sufficient that the first gas flow path 22a (second gas flow path 22b) becomes a single path at the portion connected to one first gas outlet 23a (second gas outlet 23b). In other words, multiple gas flow paths may merge upstream to form a single first gas flow path 22a (second gas flow path 22b), and the single first gas flow path 22a (second gas flow path 22b) may be connected to one first gas outlet 23a (second gas outlet 23b). The same applies to the embodiments of the slot type spray nozzle according to the present invention described below.

[0040] Next, FIG. 9 is a diagram illustrating a preferred gas flow path configuration of the slot-type spray nozzle according to the first embodiment of the present invention. FIG. 9 illustrates a more preferred positional relationship of the gas flow paths for the spray nozzle 10 according to the first embodiment. FIG. 10 illustrates a set of flow paths in a shim plate stack constituting the gas flow path shown in FIG. 9 , viewed from the discharge surface side. FIG. 10 illustrates an enlarged view of the shim plate stack 12 of the slot-type spray nozzle (spray nozzle 10) shown in FIG. 9 , viewed from the discharge surface side. As shown in FIG. 9 , when viewed along the arrows in the nozzle thickness direction, the first center line 25a and the second center line 25b intersect at a position inside the nozzle (i.e., inside the spray nozzle 10) relative to the discharge surface where the first gas discharge port 23a and the second gas discharge port 23b are located. In this configuration, as shown by the hatched area in FIG. 10 , the first gas discharge port 23a and the second gas discharge port 23b only partially overlap in the width direction near the coating liquid discharge port 33. On the other hand, non-overlapping portions can be formed at one end of each of the first gas outlet 23 a and the second gas outlet 23 b. The gases (first and second discharged gases) discharged from the non-overlapping portions of the first gas outlet 23 a and the second gas outlet 23 b are less likely to cause friction with gases having opposite widthwise velocity components. This appropriately suppresses attenuation of the widthwise velocity of each of the first and second discharged gases, thereby enabling the fine droplets of coating liquid discharged from the coating liquid outlet 33 to be more spread in the widthwise direction.

[0041] 10 , the widthwise length of the first gas outlet 23a is defined as the first gas outlet width W2a, the widthwise length of the second gas outlet 23b is defined as the second gas outlet width W2b, and the length (widthwise length) of the portion where the first gas outlet width W2a and the second gas outlet width W2b overlap in the widthwise direction on the outlet surface is defined as the overlap width W2c. The ratio of the overlap width to the gas outlet width of each of the first gas outlet 23a and the second gas outlet 23b is defined as the overlap ratio Wr. In this case, the overlap ratio Wr (Wra) of the first gas outlet 23a is expressed as Wra = W2c / W2a. The overlap ratio Wr (Wrb) of the second gas outlet 23b is expressed as Wrb = W2c / W2b. When these overlap ratios Wra and Wrb are within an appropriate range, the dispersion effect of the fine droplets by the ejected gas can be maximized.

[0042] In the pair of first gas discharge port 23a and second gas discharge port 23b, the first gas discharge width W2a and the second gas discharge width W2b are preferably the same width (W2a = W2b). The fine droplets sprayed by collision between the first discharged gas from first gas discharge port 23a and the coating liquid from coating liquid discharge port 33, and the fine droplets sprayed by collision between the second discharged gas from second gas discharge port 23b and the coating liquid from coating liquid discharge port 33, each have a velocity vector in the width direction. When the first gas discharge width W2a and the second gas discharge width W2b are the same width, when these fine droplets are viewed as a droplet group, the sum of the velocity vectors of the droplet group indicates a straight line traveling in the direction of the extension of coating liquid flow path 32. On the other hand, if the first gas discharge width W2a and the second gas discharge width W2b are different from each other, the spray direction of the droplet group will be tilted to one side of the width direction due to the different gas discharge widths at the pair of first gas discharge port 23a and second gas discharge port 23b. If the first gas discharge width W2a and the second gas discharge width W2b are the same width, the overlap ratio Wr will also be the same (Wra = Wrb). However, the first gas flow path 22a and the second gas flow path 22b do not necessarily have to have the same gas flow path shape.

[0043] To further promote the diffusion of the fine droplets, there is an optimal combination of the overlap ratio Wr and the first and second gas ejection angles θa and θb (see FIG. 5 ) for the first and second gas ejection ports 23a and 23b. Specifically, when viewed in the nozzle thickness direction, it is preferable that the overlap ratio Wr (Wra and Wrb) for each of the first and second gas ejection ports 23a and 23b be 0.3 to 0.6, and that the first and second gas ejection angles θa and θb be 50 degrees to 60 degrees. More preferably, the overlap ratio Wr is 0.3 to 0.4, and the first and second gas ejection angles θa and θb are 50 degrees to 60 degrees. In this case, a greater diffusion effect can be expected.

[0044] FIG. 11 is a diagram defining the gas discharge angle in a curved gas flow path. FIG. 11 shows an example of a gas flow path having an arc-shaped flow path as a gas flow path of the slot-type spray nozzle (spray nozzle 10) according to the first embodiment, as viewed from the nozzle thickness direction. In the description of the embodiment up to this point, a linearly extending gas flow path has been used as an example, but the shape of the gas flow path of the spray nozzle 10 is not limited. For example, the first gas flow path 22a and the second gas flow path 22b of the spray nozzle 10 may be smooth arc-shaped flow paths as shown in FIG. 11. In this case, when viewed from the arrow in the stacking direction of the shim plates of the spray nozzle 10 (i.e., the arrow in the nozzle thickness direction), a tangent to the arc is taken at the intersection of the first center line 25a of the first gas flow path 22a and the discharge surface 17, and the angle formed by the tangent and the discharge surface 17 is defined as the first gas discharge angle θa. Similarly, a tangent to the arc is taken at the intersection of the second center line 25b of the second gas flow path 22b and the discharge surface 17, and the angle formed by the tangent and the discharge surface 17 is defined as a second gas discharge angle θb.

[0045] Furthermore, in the slot-type spray nozzle (spray nozzle 10) according to the first embodiment, the coating liquid discharge port may be composed of a plurality of coating liquid small ports arranged at intervals in the width direction. FIG. 12 is a diagram illustrating the configuration of a coating liquid flow path having a plurality of coating liquid discharge small ports. FIG. 12 shows, as an arrow view seen from the nozzle thickness direction, a configuration in which the discharge port (coating liquid discharge port) of a coating liquid flow path 32 is composed of a plurality of coating liquid discharge small ports 34, as a more preferred embodiment of the slot-type spray nozzle according to the first embodiment. As shown in FIG. 12, each of the plurality of coating liquid discharge small ports 34 is arranged at a position symmetrical with respect to a perpendicular line (not shown) extending from the intersection of the first center line 25a and the second center line 25b toward the discharge surface 17, as viewed from the arrow in the stacking direction of the shim plates of the spray nozzle 10 described above (i.e., as viewed from the arrow in the nozzle thickness direction). By providing the plurality of coating liquid discharge ports 34 in this arrangement, asymmetry is created in the width direction components of the gas affected by each of the first gas discharge port 23a and the second gas discharge port 23b at each coating liquid discharge port 34. This can further improve the diffusion effect of the fine droplets of coating liquid discharged from each of the plurality of coating liquid discharge ports 34. Note that when the plurality of coating liquid discharge ports 34 are viewed as a whole, the arrangement of each of these coating liquid discharge ports 34 is symmetrical in the width direction, so that the straightness of the fine droplets can be maintained.

[0046] While FIG. 12 illustrates an example in which two coating liquid flow paths 32 are provided for a pair of gas flow paths (first gas flow path 22a and second gas flow path 22b), the number of coating liquid flow paths 32 does not necessarily have to be two and may be three or more. Furthermore, while FIG. 12 illustrates an example in which two coating liquid flow paths 32 extend in a straight line from a coating liquid manifold (see, for example, the coating liquid manifold 31 shown in FIG. 4 ) to the discharge surface, it is not necessarily required that multiple coating liquid flow paths extend in a straight line from the coating liquid manifold to the discharge surface. FIG. 13A illustrates a first example of a coating liquid flow path configuration having multiple coating liquid discharge orifices, other than that shown in FIG. 12 . FIG. 13B illustrates a second example of a coating liquid flow path configuration having multiple coating liquid discharge orifices, other than that shown in FIG. 12 . A coating liquid flow path having a plurality of coating liquid discharge small ports may be formed in a shape in which one coating liquid flow path 32 is extended to the vicinity of the discharge surface 17 and branched into a plurality of paths near the tip, as shown in Fig. 13A. Alternatively, a coating liquid flow path having a plurality of coating liquid discharge small ports may be formed in a shape in which a plurality of bent coating liquid flow paths 32 are provided, as shown in Fig. 13B.

[0047] Figure 14 is an exploded perspective view illustrating the structure of the slot-type spray nozzle according to the first embodiment of the present invention. In the spray nozzle 10 shown in Figure 14, the nozzle block 11a has a coating liquid supply port 30 that receives a coating liquid and a coating liquid manifold 31 that spreads the coating liquid in the width direction. In this nozzle block 11a, the coating liquid supply port 30 is connected to the coating liquid manifold 31. Also, as shown in Figure 14, the nozzle blocks 11a and 11b have gas supply ports 20a and 20b that receive a gas and gas manifolds 21a and 21b that spread the gas in the width direction, respectively. In these nozzle blocks 11a and 11b, the gas supply ports 20a and 20b are connected to the gas manifolds 21a and 21b, respectively.

[0048] 14 , the first gas shim plate 13a and the second gas shim plate 13b have comb-shaped flow paths that are inclined in different directions relative to the discharge surface of the spray nozzle 10. When the first gas shim plate 13a is mated with the nozzle block 11a and the first partition shim plate 14a, the grooves between the comb teeth of the first gas shim plate 13a form a plurality of first gas flow paths 22a and first gas discharge ports 23a aligned in the width direction. Similarly, when the second gas shim plate 13b is mated with the nozzle block 11b and the second partition shim plate 14b, the grooves between the comb teeth of the second gas shim plate 13b form a plurality of second gas flow paths 22b and second gas discharge ports 23b aligned in the width direction. The grooves between the comb teeth of the first gas shim plate 13a communicate with the gas manifold 21a, allowing the pressurized gas supplied to the gas manifold 21a to be guided to the first gas outlet port 23a. Similarly, the grooves between the comb teeth of the second gas shim plate 13b communicate with the gas manifold 21b, allowing the pressurized gas supplied to the gas manifold 21b to be guided to the second gas outlet port 23b.

[0049] The coating liquid shim plate 15 has comb-shaped flow paths similar to the first gas shim plate 13a and second gas shim plate 13b described above. When the coating liquid shim plate 15 is mated with the first partition shim plate 14a and second partition shim plate 14b, grooves between the comb teeth of the coating liquid shim plate 15 form a plurality of coating liquid flow paths 32 aligned in the width direction and coating liquid discharge ports 33. Each of the plurality of coating liquid flow paths 32 communicates with the coating liquid manifold 31 through cutout portions 35 formed in the gas shim plate 13a and the partition shim plate 14a. The plurality of coating liquid flow paths 32 can guide the coating liquid supplied to the coating liquid manifold 31 to each of the plurality of coating liquid discharge ports 33.

[0050] [Embodiment 2] Figure 15 is a schematic diagram showing how sprayed fine droplets spread in a slot-type spray nozzle according to embodiment 2 of the present invention. Figure 15 is an enlarged view of a gas flow path portion of a slot-type spray nozzle according to embodiment 2 of the present invention (hereinafter sometimes referred to as the spray nozzle of embodiment 2) as viewed from the nozzle thickness direction. Figure 16 is an enlarged view of the slot-type spray nozzle shown in Figure 15 as viewed from the discharge surface side. Although the overall configuration of the spray nozzle of embodiment 2 is not particularly shown, in this spray nozzle, when viewed along the arrow in the nozzle thickness direction, both inner wall surfaces of the first gas flow path 22a and the second gas flow path 22b connected to the first gas discharge port 23a and the second gas discharge port 23b, which are paired with each other across the coating liquid discharge port 33, are inclined in a manner such that they move away from the coating liquid discharge port 33 as they move toward the discharge surface 17 of the spray nozzle.

[0051] 15 , in the spray nozzle of the second embodiment, the first gas flow path 22 a and the second gas flow path 22 b (arranged to overlap the first gas flow path 22 a in FIG. 15 ) each have a tapered shape that increases in width from the interior of the spray nozzle toward the discharge surface 17. That is, when viewed from the arrow in the nozzle thickness direction, both inner wall surfaces of the first gas flow path 22 a and the second gas flow path 22 b are inclined in a manner that increases in distance from the coating liquid discharge port 33 toward the discharge surface 17. When the first gas flow path 22 a and the second gas flow path 22 b have a tapered shape as described above, as shown in FIG. 16 , the gas discharged from the width direction center of the first gas discharge port 23 a does not have a width direction velocity component, but the gas discharged from the width direction end of the first gas discharge port 23 a has a width direction velocity component as indicated by the solid line arrow 26 a. Similarly, the gas discharged from the widthwise center of the second gas discharge port 23b does not have a widthwise velocity component, but the gas discharged from the widthwise end of the second gas discharge port 23b does have a widthwise velocity component as shown by the dashed arrows 26b. Therefore, with the spray nozzle of this second embodiment, as with the description of FIG. 6 in the first embodiment above, it is possible to obtain the effect of diffusing the sprayed fine droplets.

[0052] Fig. 17 is a diagram illustrating a more preferable gas flow path configuration in a slot-type spray nozzle according to Embodiment 2 of the present invention. Fig. 17 illustrates a more preferable positional relationship of the gas flow paths for the spray nozzle of Embodiment 2 shown in Figs. 15 and 16. In the spray nozzle of Embodiment 2, as shown in Fig. 17, the first gas flow path 22a and the second gas flow path 22b are arranged such that, when viewed in the nozzle thickness direction (shim plate stacking direction), a first center line 25a taken through the centers of both inner wall surfaces of the first gas flow path 22a and a second center line 25b taken through the centers of both inner wall surfaces of the second gas flow path 22b are located on opposite sides of a perpendicular line (not shown) to the discharge surface 17 that passes through the center of the coating liquid discharge port 33.

[0053] When the spray nozzle of the second embodiment is viewed from the discharge port side (discharge surface 17 side), the first gas discharge port 23a, the second gas discharge port 23b, and the coating liquid discharge port 33 of the spray nozzle appear to have the same configuration as that shown in Fig. 10. The definitions of the overlapping width W2c and the overlapping ratio Wr between the first gas discharge port 23a and the second gas discharge port 23b are the same as those in the first embodiment shown in Fig. 10. That is, in the second embodiment as well, when the widthwise length of the first gas discharge port 23a is defined as the first gas discharge width W2a, the widthwise length of the second gas discharge port is defined as the second gas discharge width W2b, and the length (widthwise length) of the portion where the first gas discharge width W2a and the second gas discharge width W2b overlap in the width direction on the discharge surface is defined as the overlapping width W2c, the ratio of the overlapping width to the respective gas discharge widths of the first gas discharge port 23a and the second gas discharge port 23b is defined as the overlapping ratio Wr. In this case, the overlap ratio Wr (Wra) of the first gas outlet 23a is expressed as Wra = W2c / W2a. The overlap ratio Wr (Wrb) of the second gas outlet 23b is expressed as Wrb = W2c / W2b. When these overlap ratios Wra and Wrb are within an appropriate range, the dispersion effect of the fine droplets by the discharged gas can be maximized. Even when the spray nozzle of the second embodiment has tapered discharge flow paths as shown in FIG. 17 for the first gas outlet 23a and the second gas outlet 23b, as in the first embodiment described above, when the sprayed fine droplets are viewed as a droplet group, the droplet group travels straight in the direction of the extension of the coating liquid flow path 32. For this reason, it is preferable that the pair of first gas discharge width W2a and second gas discharge width W2b are the same width (W2a = W2b), and in this case, the overlap rates Wra and Wrb of the first gas discharge port 23a and the second gas discharge port 23b are also the same (Wra = Wrb). However, the first gas flow path 22a and the second gas flow path 22b do not necessarily have to have the same gas flow path shape.

[0054] 17 , there is an optimal overlap ratio Wr for the first gas outlet 23a and the second gas outlet 23b for further promoting the diffusion of the fine droplets. Specifically, when viewed from the arrow in the nozzle thickness direction, the overlap ratio Wr (Wra and Wrb) for each of the first gas outlet 23a and the second gas outlet 23b is preferably 0.3 or less. While the lower limit of the overlap ratio Wr is not particularly limited, it is preferably 0.2 or greater.

[0055] In the spray nozzle of the second embodiment, the overall appearance and disassembled state of the spray nozzle are similar to those of the spray nozzle 10 of the first embodiment described above. That is, the spray nozzle of the second embodiment has the same configuration as the spray nozzle 10 of the first embodiment described above, except for the configurations of the first gas flow path 22a and the second gas flow path 22b shown in Figures 15 and 17. The appearance of the spray nozzle of the second embodiment is similar to that shown in Figures 1 to 3, and the disassembled state of the spray nozzle of the second embodiment is similar to that shown in Figure 14. Furthermore, in the spray nozzle of the second embodiment, it is also preferable that the discharge port of the coating liquid flow path 32 is composed of a plurality of coating liquid discharge small ports 34, as in the configuration of the spray nozzle 10 of the first embodiment described above shown in Figures 12, 13A, and 13B.

[0056] The effectiveness of the present invention will be explained using examples, but the scope of the present invention is not limited to these examples.

[0057] Example 1 In Example 1, a spray nozzle 10 having a configuration similar to that of the slot-type spray nozzle shown in Figures 1 to 10 and 14 was used. A detailed description will be given of the shim plate stack 12 used in this spray nozzle 10. As described above, the shim plate stack 12 is composed of first gas shim plate 13a, second gas shim plate 13b, first partition wall shim plate 14a, second partition wall shim plate 14b, and coating liquid shim plate 15 (see Figures 2 and 14).

[0058] In the shim plate stack 12 of Example 1, the first gas shim plate 13a and the second gas shim plate 13b each had a thickness of 50 μm, a first gas discharge width W2a and a second gas discharge width W2b both of 3 mm, and the first gas discharge angle θa and the second gas discharge angle θb were the same. Furthermore, the first gas shim plate 13a and the second gas shim plate 13b each used multiple types of gas shim plates whose first gas discharge angle θa and second gas discharge angle θb each differed in seven steps of 10 degrees from 30 degrees to 90 degrees. By stacking these first gas shim plates 13a and second gas shim plates 13b while shifting them from each other in the width direction of the spray nozzle 10, the overlap ratio Wr of each of the first gas discharge port 23a and the second gas discharge port 23b was reduced in seven steps from 1.0 to 0.2 in increments of approximately 0.13. Because the first gas discharge width W2a and the second gas discharge width W2b are the same width, the overlap ratio Wra of the first gas discharge port 23a and the overlap ratio Wrb of the second gas discharge port 23b are the same value.

[0059] The first partition shim plate 14a and the second partition shim plate 14b each had a thickness of 50 μm. The coating liquid shim plate 15 had a thickness of 50 μm and a coating liquid discharge width W1 of 100 μm. To facilitate evaluation of the diffusibility of the gas and coating liquid per set of discharge ports, the first gas shim plate 13a was provided with only one set of a first gas flow path 22a and a first gas discharge port 23a, the second gas shim plate 13b was provided with only one set of a second gas flow path 22b and a second gas discharge port 23b, and the coating liquid shim plate 15 was provided with only one set of a coating liquid flow path 32 and a coating liquid discharge port 33.

[0060] [Evaluation Method] The evaluation method of Example 1 will be described in detail. In the evaluation method of Example 1, water was used as the coating liquid and air was used as the gas. In order to visualize the distribution of the sprayed fine droplets, water-sensitive test paper (manufactured by Syngenta) that has the property of irreversibly discoloring the areas where water droplets adhere was used, and the droplets were sprayed onto this.

[0061] Next, the installation configuration of the evaluation device will be described. FIG. 18 is a diagram illustrating the configuration for an embodiment of a slot-type spray nozzle according to the present invention. As shown in FIG. 18 , the spray nozzle 10 was installed so that the discharge surface 17 was parallel to the direction of gravity, and an evaluation plate 43 was placed directly in front of the nozzle so that the surface of the plate 43 was parallel to the discharge surface 17 of the spray nozzle 10. The distance from the discharge surface 17 of the spray nozzle 10 to the plate 43 was 80 mm, and a water-sensitive test paper 44 measuring 52 mm in length and 76 mm in width was attached to the center of the surface of the plate 43. The plate 43 was transported in the transport direction 50 indicated by the arrow in FIG. 18 by a robot cylinder (manufactured by IAI) (not shown). The plate 43 was passed perpendicular to the spray direction of droplets sprayed from the spray nozzle 10, causing a small amount of droplets to adhere to the water-sensitive test paper 44, and the distribution of the droplets was obtained. At this time, the deposited droplets are distributed in a spread manner to the left and right around the position of the coating liquid discharge port of the spray nozzle 10, and as shown in FIG. 19, a group of vertically striped droplets 45 are deposited on the water-sensitive test paper 44.

[0062] In the evaluation method of Example 1, the width W4 of the deposited droplet group 45 was measured as described above, and the larger this value was, the greater the diffusibility was determined to be. The reference example was an example based on a slot-type spray nozzle that satisfied the following conditions: the first gas discharge angle θa and the second gas discharge angle θb were each 90 degrees, and the overlap ratio Wr at each of the first gas discharge port 23a and the second gas discharge port 23b was 1.0. The evaluation results of the diffusing effect of the droplet group 45 were classified into the following five levels based on these conditions. A: The droplet group 45 spreads three times or more than the reference example. B: The droplet group 45 spreads two to three times more than the reference example. C: The droplet group 45 spreads less than twice as much as the reference example. D: The droplet group 45 spreads more than the reference example, but the droplet group 42 sprayed from the spray nozzle 10 is distributed so that the center is thin and the edges are thick, as shown in Figure 20. E: The width W4 of the droplet group 45 is equal to or less than the width (reference width) of the reference example, and there is no diffusing effect.

[0063] The evaluation results for Example 1 are shown in Table 1. In Table 1, the numbers in parentheses are the measured values ​​of the width W4 of the droplet group 45, and the units of the measurements are millimeters. The upper limit of the measurement of the width W4 is 76 mm, which is the width of the water-sensitive test paper 44 to which the droplet group 45 is attached. In Table 1, "gas discharge angle θ" is a collective term for the first gas discharge angle θa and the second gas discharge angle θb of the spray nozzle 10 used in the evaluation. "Overlap ratio Wr" is a collective term for the overlap ratio Wra of the first gas discharge port 23a and the overlap ratio Wrb of the second gas discharge port 23b of the spray nozzle 10. These collective terms are also used in the following description.

[0064]

[0065] The evaluation results of Example 1 shown in Table 1 indicate that reducing the gas discharge angle θ below 90 degrees results in a greater diffusion effect of the sprayed fine droplets. Furthermore, when the gas discharge angle θ is less than 90 degrees, reducing the overlap ratio Wr tends to result in a greater diffusion effect of the fine droplets. Furthermore, when the gas discharge angle θ is 90 degrees, reducing the overlap ratio Wr does not result in a greater diffusion effect of the fine droplets. Therefore, it is necessary to reduce not only the overlap ratio Wr but also the gas discharge angle θ. To achieve a greater diffusion effect of the fine droplets, the combination of the overlap ratio Wr and the gas discharge angle θ is important. Specifically, to achieve a diffusion effect at least twice that of the reference example, the overlap ratio Wr must be between 0.3 and 0.6, and the gas discharge angle θ must be between 50 and 60 degrees. Furthermore, to achieve a diffusion effect three times greater than that of the reference example, the overlap ratio Wr must be 0.3 to 0.4, and the gas ejection angle θ must be 50 degrees to 60 degrees. Combinations of the overlap ratio Wr and the gas ejection angle θ outside this range may achieve a greater diffusion effect in the width direction, but the distribution of the sprayed droplets may become uneven, as shown in droplet group 42 in FIG. 20. As a result, when a large number of gas ejection ports (e.g., first gas ejection port 23a and second gas ejection port 23b) and coating liquid ejection ports 33 are arranged on the ejection surface 17, it may be difficult to achieve a uniform distribution of the sprayed fine droplets.

[0066] In Example 2, a shim plate stack 12 having first gas flow passages 22a and second gas flow passages 22b with flow passage shapes as shown in Figures 15 to 17 (a shim plate stack of a slot-type spray nozzle according to Embodiment 2 of the present invention) was used instead of the shim plate stack 12 of Example 1. The shim plate stack 12 used in Example 2 will be described in detail below.

[0067] In the shim plate stack 12 of Example 2, the first gas shim plate 13a and the second gas shim plate 13b each had a thickness of 50 μm, and the first gas discharge width W2a and the second gas discharge width W2b were both 3 mm. Furthermore, in these first gas shim plates 13a and 13b, the first gas flow path 22a had a width of 1 mm at the portion communicating with the gas manifold 21a and was a tapered flow path that widened to 3 mm toward the first gas discharge port 23a. Similarly, the second gas flow path 22b had a width of 1 mm at the portion communicating with the gas manifold 21b and was a tapered flow path that widened to 3 mm toward the second gas discharge port 23b. The first partition wall shim plate 14a and the second partition wall shim plate 14b each had a thickness of 50 μm. Other than these, the configuration was the same as in Example 1 described above.

[0068] In Example 2, the evaluation was also performed under the same conditions as in Example 1. The evaluation results for Example 2 are shown in Table 2. For comparison with the conventional flow path shape, Table 2 also lists the evaluation results for the case where the "gas discharge angle θ is 90 degrees" shown in Table 1.

[0069]

[0070] The evaluation results for Example 2 shown in Table 2 reveal that Example 2, in which the gas flow path is simply tapered, can achieve a greater diffusion effect for the sprayed fine droplets than the reference example, regardless of the overlap ratio Wr. Furthermore, the flow path shape of Example 2 also has an optimal range for the overlap ratio Wr, and results show that at least when the overlap ratio Wr is 0.3 or less, the diffusion effect for the fine droplets is increased compared to when the overlap ratio Wr is 1.0.

[0071] As described above, the slot type spray nozzle according to the present invention can be widely used for applying finely divided coating liquid to a substrate.

[0072] 10 spray nozzle 11a, 11b nozzle block 12 shim plate stack 13a first gas shim plate 13b second gas shim plate 14a first partition shim plate 14b second partition shim plate 15 coating liquid shim plate 16 fixing bolt 17 discharge surface 20a, 20b gas supply port 21a, 21b gas manifold 22a first gas flow path 22b second gas flow path 23a first gas discharge port 23b second gas discharge port 24aL, 24aR first gas flow path inner wall surface 24bL, 24bR second gas flow path inner wall surface 25a, 25b center line 26a solid line arrow 26b dashed line arrow 30 coating liquid supply port 31 coating liquid manifold 32 coating liquid flow path 33 Coating liquid discharge port 34 Coating liquid discharge small port 35 Cutout portion 40 Substrate 41 Coating film 42 Droplet group 43 Plate 44 Water-sensitive test paper 45 Droplet group (attached droplet group) 50 Transport direction d Fixed distance P Array pitch of coating liquid discharge port W1 Coating liquid discharge width W2 Gas discharge width W2a First gas discharge width W2b Second gas discharge width W2c Gas discharge overlap width W3 Spray width W4 Width of attached droplet group Wra, Wrb Overlap ratio θa, θb Gas discharge angle

Claims

1. A slot-type spray nozzle extending in the width direction, comprising: a plurality of coating liquid discharge ports arranged at intervals across the width direction; a plurality of first gas discharge ports and a plurality of second gas discharge ports arranged in pairs on either side of the coating liquid discharge port and spaced apart across the width direction; a first gas flow path connecting the interior of the slot-type spray nozzle to the first gas discharge port; and a second gas flow path connecting the interior of the slot-type spray nozzle to the second gas discharge port, wherein the surface on which the coating liquid discharge port, the first gas discharge port, and the second gas discharge port are located is defined as a discharge surface, and the direction in which the coating liquid discharge port is sandwiched between the first gas discharge port and the second gas discharge port is defined as the nozzle thickness direction, a first center line and a second center line taken through the centers of both inner wall surfaces of the first gas flow path and the second gas flow path connected to the first gas discharge port and the second gas discharge port, respectively, which are a pair with the coating liquid discharge port sandwiched between them, intersect the discharge surface at inclinations in opposite directions to each other with respect to a perpendicular to the discharge surface that passes through the center of the coating liquid discharge port, when viewed with an arrow in the nozzle thickness direction.

2. The slot type spray nozzle according to claim 1, characterized in that, when viewed along an arrow in the nozzle thickness direction, the first center line and the second center line intersect inside the slot type spray nozzle.

3. The slot-type spray nozzle according to claim 2, characterized in that, when viewed with an arrow in the nozzle thickness direction, the ratio of the widthwise length of the overlapping portion of the first gas outlet and the second gas outlet, which are a pair sandwiching the coating liquid outlet, to the widthwise lengths of the first gas outlet and the second gas outlet is 0.3 to 0.6, and the angles formed by the first center line and the second center line and the outlet surface are 50 degrees to 60 degrees.

4. A slot-type spray nozzle according to any one of claims 1 to 3, characterized in that the coating liquid discharge port is made up of a plurality of coating liquid discharge small ports arranged at intervals in the width direction, and when viewed with an arrow in the nozzle thickness direction, the plurality of coating liquid discharge small ports are arranged in positions that are symmetrical with respect to an axis of symmetry that is a perpendicular line to the discharge surface that passes through the point where the first center line and the second center line intersect.

5. A slot-type spray nozzle extending in the width direction, comprising: a plurality of coating liquid discharge ports arranged at intervals in the width direction; a first gas discharge port and a second gas discharge port arranged in pairs with the coating liquid discharge port sandwiched between them and arranged at intervals in the width direction; a first gas flow path connecting the interior of the slot-type spray nozzle to the first gas discharge port; and a second gas flow path connecting the interior of the slot-type spray nozzle to the second gas discharge port, wherein a surface on which the coating liquid discharge port, the first gas discharge port, and the second gas discharge port are present is defined as a discharge surface, and the direction in which the coating liquid discharge port is sandwiched between the first gas discharge port and the second gas discharge port is defined as a nozzle thickness direction, and when viewed with an arrow in the nozzle thickness direction, both inner wall surfaces of the first gas flow path and the second gas flow path connected to the first gas discharge port and the second gas discharge port, respectively, which are paired with each other with the coating liquid discharge port sandwiched between them, are inclined in a manner that they move away from the coating liquid discharge port as they approach the discharge surface. A slot-type spray nozzle characterized by:

6. The slot-type spray nozzle according to claim 5, wherein, when viewed along an arrow in the nozzle thickness direction, a first center line taken through the centers of both inner wall surfaces of the first gas flow path and a second center line taken through the centers of both inner wall surfaces of the second gas flow path are located on opposite sides of a perpendicular line to the discharge surface that passes through the center of the coating liquid discharge port.

7. The slot-type spray nozzle according to claim 6, characterized in that, when viewed from the arrow in the nozzle thickness direction, the ratio of the widthwise length of the overlapping portion of the first gas outlet and the second gas outlet, which are a pair sandwiching the coating liquid outlet, to the widthwise lengths of the first gas outlet and the second gas outlet is 0.3 or less.

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