Coating die head and coating device

Abstract

The utility model relates to a coating die head and a coating device, and the coating die head comprises a front knife lip which is provided with a first surface facing a substrate to be coated; the rear knife lip is provided with a second face facing the substrate to be coated, and the rear knife lip and the front knife lip are arranged in a spaced mode to define a slit; the first hydrophilic layer is arranged on the first surface, and the first hydrophobic layer is arranged on the second surface. According to the coating die head and the coating device, the phenomenon of liquid film breakage is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery preparation device, in particular to a coating die and a coating device. BACKGROUND

[0002] The slit coating is a kind of coating technology that under a certain pressure, the solution is pressed out along the gap of the die to be transferred to the substrate to be coated. It is applied in the field of battery preparation due to the advantages of fast coating speed and good coating film uniformity.

[0003] The coating die of the slit coating device includes a front blade lip and a back blade lip, and the front blade lip and the back blade lip are spaced apart to define a slit therebetween. In the process of coating, the coating die moves relative to the substrate to be coated, and the solution is discharged from the slit of the coating die to the substrate to be coated, so as to form a liquid film on the substrate to be coated. However, the liquid film coated on the substrate to be coated by the coating die in the related art is prone to the phenomenon of liquid film rupture. CONTENT OF THE INVENTION

[0004] In view of the above problems, the present application provides a coating die and a coating device, which can reduce the phenomenon of liquid film rupture on the substrate to be coated.

[0005] In a first aspect, the embodiments of the present application provide a coating die, which includes:

[0006] The front blade lip has a first surface facing the substrate to be coated.

[0007] The back blade lip has a second surface facing the substrate to be coated, and the back blade lip is spaced apart from the front blade lip to define a slit.

[0008] The first hydrophilic layer is arranged on the first surface, and the first hydrophobic layer is arranged on the second surface.

[0009] In actual coating, one side of the front blade lip and the rear blade lip faces the substrate to be coated, and the solution is discharged from the gap between the front blade lip and the rear blade lip to the substrate to be coated to form a liquid film. During the coating process, the coating die moves relative to the substrate to be coated, and the liquid film coated on the substrate to be coated is formed behind the front blade lip. Therefore, the side of the rear blade lip facing the substrate to be coated continuously passes through the liquid film. Since the second surface of the rear blade lip facing the substrate to be coated is provided with the first hydrophobic layer, the first hydrophobic layer is not easy to adhere to the solution, so that the solution is not easy to adhere to the rear blade lip, thereby the problem of poor coating quality caused by solution adhesion can be improved as much as possible. On this basis, if the solution discharged from the gap overflows between the front blade lip and the substrate to be coated, the first hydrophilic layer provided on the first surface of the front blade lip can adsorb the solution, so that the solution overflowing between the front blade lip and the substrate to be coated is tightly attached to the first hydrophilic layer, thereby the air mixed between the first hydrophilic layer and the solution can be reduced as much as possible, and the air mixed in the solution can be reduced as much as possible, and the phenomenon of liquid film rupture is improved. Moreover, the air mixed in the solution can be reduced as much as possible to extrude the local position of the liquid film, thereby the uniformity of the liquid film is improved.

[0010] In some embodiments, the second surface is provided with a hydrophilic groove; the first hydrophobic layer is located on one side of the hydrophilic groove close to the gap; and the coating die further comprises a second hydrophilic layer, which is arranged on the groove wall of the hydrophilic groove.

[0011] When the solution discharged from the gap accumulates too much between the rear blade lip and the substrate to be coated, the solution can overflow into the hydrophilic groove, and the second hydrophilic layer on the groove wall of the hydrophilic groove has hydrophilicity, which can make the solution adsorb in the hydrophilic groove as much as possible. Thus, the solution accumulation between the rear blade lip and the substrate to be coated is reduced, thereby the situation that the liquid film is too thick can be effectively reduced, and the situation that the solution leaks can be reduced. Since the solution is discharged from the gap and enters between the rear blade lip and the substrate to be coated, the solution discharged from the gap first passes through the first hydrophobic layer and then passes through the hydrophilic groove. In this embodiment, the first hydrophobic layer is located on one side of the hydrophilic groove close to the gap, so that the excess solution is not easy to adhere to the rear blade lip due to the presence of the first hydrophobic layer before entering the hydrophilic groove.

[0012] In some embodiments, the hydrophilic groove comprises a first groove wall and a second groove wall opposite to each other; one side of the first groove wall is connected with the second surface, and one side of the second groove wall is connected with the second surface; and the first groove wall and the second groove wall are respectively provided with a second hydrophilic layer.

[0013] Since one side edge of the first groove wall is connected with the second face and one side edge of the second groove wall is connected with the second face, the solution entering the hydrophilic groove first contacts the first groove wall and the second groove wall. By arranging the second hydrophilic layer on the first groove wall and the second groove wall respectively, the solution entering the hydrophilic groove can be quickly adsorbed by the second hydrophilic layer on the first groove wall and the second groove wall, and thus the accumulated solution can quickly enter the hydrophilic groove. That is, the phenomenon of over-thick liquid film and solution leakage caused by solution accumulation can be quickly and effectively improved.

[0014] In some embodiments, one side edge of the first groove wall away from the second face and one side edge of the second groove wall away from the second face are connected; and the first groove wall and the second groove wall are arranged at an included angle.

[0015] Since one side edge of the first groove wall away from the second face and one side edge of the second groove wall away from the second face are connected, the distance between the first groove wall and the second groove wall gradually decreases along the direction of the recess of the hydrophilic groove on the second face, that is, the distance between the second hydrophilic layers arranged on the first groove wall and the second groove wall decreases, so that the solution between the second hydrophilic layers on the two groove walls can be reliably adsorbed.

[0016] In some embodiments, the hydrophilic groove further comprises a bottom wall connected between the first groove wall and the second groove wall; the bottom wall is provided with a second hydrophilic layer.

[0017] By connecting one side edge of the first groove wall away from the second face and one side edge of the second groove wall away from the second face with both ends of the bottom wall respectively, the hydrophilic groove thus constructed (compared with the hydrophilic groove shown in FIG. 1 and FIG. 2) has a larger capacity and can accommodate more solution, so that the phenomenon of over-thick liquid film and solution leakage caused by solution accumulation can be better improved.

[0018] In some embodiments, the ratio α of the size of the hydrophilic groove along the first direction to the size of the second face along the first direction satisfies the condition: 4 / 15≤α≤2 / 5;

[0019] The ratio β of the size of the hydrophilic groove along the second direction to the size of the hydrophilic groove along the first direction satisfies the condition: 5 / 2≤β≤15 / 4;

[0020] Wherein, the first direction is along the direction in which the first groove wall and the second groove wall face each other, and the second direction is perpendicular to the second face.

[0021] By the size design of the hydrophilic groove of the present embodiment, the amount of excess solution generated by conventional coating can be accommodated by the hydrophilic groove, so that the phenomenon of over-thick liquid film and solution leakage caused by solution accumulation can be effectively improved.

[0022] In some embodiments, the coating die further comprises a second hydrophobic layer, the second hydrophobic layer is arranged on the second face, and the second hydrophobic layer is located on the side of the hydrophilic groove away from the first hydrophobic layer.

[0023] Since the second hydrophobic layer is located on the side of the hydrophilic groove away from the first hydrophobic layer, that is, the first hydrophobic layer and the second hydrophobic layer are located on the two sides of the hydrophilic groove respectively, after the accumulated solution enters the hydrophilic groove, the second side can also resist the adhesion of the solution through the hydrophobic layers on the two sides of the hydrophilic groove respectively, thereby further reducing the adhesion of the solution on the trailing lip.

[0024] In some embodiments, the trailing lip has a third side facing away from the leading lip; the coating die further comprises a third hydrophobic layer arranged on the third side.

[0025] By arranging the third hydrophobic layer, the adhesion of the solution on the third side of the trailing lip facing away from the leading lip can be minimized, thereby improving the coating quality problem caused by the adhesion of the solution.

[0026] In some embodiments, the coating die further comprises a fourth hydrophobic layer arranged on the first side, and the first hydrophilic layer is located on the side of the fourth hydrophobic layer close to the slit.

[0027] If there is too much solution overflowing between the leading lip and the substrate to be coated, the solution may overflow between the fourth hydrophobic layer and the substrate to be coated. The fourth hydrophobic layer is not easy to adhere to the solution, so that the solution is not easy to adhere to the leading lip, thereby minimizing the problem of poor coating quality caused by the adhesion of the solution.

[0028] In some embodiments, the leading lip has a fourth side facing away from the trailing lip; the coating die further comprises a fifth hydrophobic layer arranged on the fourth side.

[0029] By arranging the fifth hydrophobic layer, the adhesion of the solution on the fourth side of the leading lip facing away from the trailing lip can be minimized, thereby improving the coating quality problem caused by the adhesion of the solution.

[0030] In some embodiments, the second side is parallel or coplanar to the first side.

[0031] In some embodiments, the second side and the first side form an included angle between the planes on which they are located; wherein, in the direction of the coating die towards the substrate to be coated, the distance between the second side and the first side gradually expands.

[0032] The arrangement of the second side and the first side of the coating die of the present embodiment is suitable for solutions with high viscosity. The flow rate of the solution with high viscosity is slow, so the injection pressure required when injecting the solution into the coating die is large, so the injection speed of the solution is fast. When the solution with high speed enters between the second side and the first side after passing through the fine and narrow slit, the speed can be buffered, reducing the turbulent flow phenomenon of the solution, thereby improving the film forming effect.

[0033] In a second aspect, the embodiments of the present application provide a coating device, which comprises a driving mechanism and the coating die of any of the above embodiments, and the driving mechanism is used to drive the coating die or the substrate to be coated to move, so that the coating die and the substrate to be coated move relative to each other.

[0034] In the actual coating process, one side of the front blade lip and the rear blade lip faces the substrate to be coated, and the solution is discharged from the gap between the front blade lip and the rear blade lip to the substrate to be coated to form a liquid film. In the coating process, the coating die and the substrate to be coated move relative to each other, and the liquid film coated on the substrate to be coated is formed behind the front blade lip. Therefore, the side of the rear blade lip facing the substrate to be coated will continuously pass through the liquid film. Since the second surface of the rear blade lip facing the substrate to be coated is provided with the first hydrophobic layer, the first hydrophobic layer is not easy to adhere to the solution, so that the solution is not easy to adhere to the rear blade lip, thereby the problem of poor coating quality caused by the adhesion of the solution can be improved as much as possible. On this basis, if the solution discharged from the gap overflows between the front blade lip and the substrate to be coated, the first hydrophilic layer arranged on the first surface of the front blade lip can adsorb the solution, so that the solution overflowing between the front blade lip and the substrate to be coated is closely attached to the first hydrophilic layer, thereby the air mixed between the first hydrophilic layer and the solution can be reduced as much as possible, and the air mixed in the solution can be reduced as much as possible, and the phenomenon of liquid film rupture is improved. Moreover, the extrusion of the air mixed in the solution to the local position of the liquid film can be reduced as much as possible, thereby the uniformity of the liquid film is improved.

[0035] The above description is only a summary of the technical solutions of the present application. In order to make the technical means of the present application more clearly understood, the embodiments of the present application can be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described in detail. BRIEF DESCRIPTION OF DRAWINGS

[0036] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the present application. Moreover, the same reference numerals are used throughout the same figures. In the drawings:

[0037] Figure 1 Structure schematic diagram of the coating die of some embodiments of the present application coating solution to the substrate to be coated.

[0038] Figure 2 Structure schematic diagram of the coating die of some embodiments of the present application coating solution to the substrate to be coated.

[0039] Figure 3 Structure schematic diagram of the coating die of some embodiments of the present application coating solution to the substrate to be coated.

[0040] Figure 4 Structure diagram of a coating die for coating a solution onto a substrate to be coated according to some embodiments of the present application.

[0041] Figure 5 Structure diagram of a coating die for coating a solution onto a substrate to be coated according to some embodiments of the present application.

[0042] Figure 6 Structure diagram of a coating die for coating a solution onto a substrate to be coated according to some embodiments of the present application.

[0043] Figure 7 Structure diagram of a coating die for coating a solution onto a substrate to be coated according to some embodiments of the present application.

[0044] Reference signs in the detailed description of the embodiments are as follows:

[0045] 10, solution; 20, substrate to be coated; 101, slit;

[0046] 110, rake lip; 111, first face; 112, fourth face; 210, first hydrophilic layer; 220, fourth hydrophobic layer; 230, fifth hydrophobic layer;

[0047] 120, clearance lip; 121, second face; 122, third face; 1211, hydrophilic groove; 1211a, first groove wall; 1211b, second groove wall; 1211c, bottom wall; 310, first hydrophobic layer; 320, second hydrophilic layer; 330, second hydrophobic layer; 340, third hydrophobic layer. DETAILED DESCRIPTION

[0048] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments of the present application, and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0050] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0051] Reference within this document to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that any of the embodiments described herein can be combined with any of the other embodiments unless explicitly stated otherwise.

[0052] In the description of the embodiments of the present application, the term "and / or" is merely used to describe associated objects, that is, there can be three relationships, for example, A and / or B, which means that there are three cases, A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this document generally means that the front and rear associated objects are in an "or" relationship.

[0053] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0054] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0055] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing", and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0056] At present, from the development of market situation, the application of battery device is more and more extensive. The battery device is not only applied to the energy storage power system of hydropower, thermal power, wind power and solar power station, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment and aerospace and other fields. With the continuous expansion of the application field of battery device, the demand of its market is also increasing.

[0057] Slit coating is a kind of coating technology that the solution is pressed out along the gap of the die to transfer to the substrate to be coated under a certain pressure. It is applied in the field of battery preparation due to the advantages of fast coating speed and good coating film uniformity.

[0058] The coating die of the slit coating device includes a front blade lip and a rear blade lip, and the front blade lip and the rear blade lip are arranged at intervals, so as to define a slit between the two. In the coating process, the coating die moves relative to the substrate to be coated, and the solution is discharged from the slit of the coating die to the substrate to be coated, so as to form a liquid film on the substrate to be coated.

[0059] In order to reduce the problem of poor coating quality caused by the adhesion of solution on the coating die in the coating process, the surface of the front blade lip and the rear blade lip of the coating die of the slit coating device in the related art is respectively provided with a hydrophobic layer. However, the liquid film coated on the substrate to be coated by such coating die is prone to the phenomenon of liquid film rupture. The reason is that in actual coating, the relative moving speed of the coating die and the substrate to be coated and the discharging speed of the solution from the slit are not completely consistent. When the discharging speed of the solution from the slit is too fast or the relative moving speed of the coating die and the substrate to be coated is too slow, the solution discharged from the slit to the substrate to be coated will not only form a liquid film behind the front blade lip, but also overflow between the front blade lip and the substrate to be coated. Since the surface of the front blade lip towards the substrate to be coated is provided with a hydrophobic layer, air is easy to enter between the hydrophobic layer and the solution, so as to easily cause air to mix into the solution in the solution flowing process, and further easily cause the liquid film to rupture. Moreover, due to the extrusion of the mixed air to the local position of the liquid film, the liquid film is prone to be uneven.

[0060] Please refer to Figure 1 , Figure 1 The structure schematic diagram of the coating die of some embodiments of the present application coating solution to the substrate to be coated is shown. The coating die provided by some embodiments of the present application is used to coat solution 10 to the substrate to be coated 20.

[0061] The coating die includes a front lip 110, a rear lip 120, a first hydrophilic layer 210, and a first hydrophobic layer 310. The front lip 110 has a first surface 111 facing the substrate 20 to be coated. The rear lip 120 has a second surface 121 facing the substrate 20 to be coated, and the rear lip 120 and the front lip 110 are spaced apart to define a slit 101. The first hydrophilic layer 210 is disposed on the first surface 111, and the first hydrophobic layer 310 is disposed on the second surface 121.

[0062] Specifically, the front blade lip 110 and the rear blade lip 120 can be fixedly connected. The front blade lip 110 and the rear blade lip 120 can be spaced apart by setting a shim, or they can be left un-spaced, as long as a gap is maintained between them. The gap between the front blade lip 110 and the rear blade lip 120 is the slit 101. Figure 1 The diagram shows the XX' axis and ZZ' axis, where the depth direction of the slit 101 is along the ZZ' direction. The solution can be discharged from the slit 101 along the OZ' direction of the depth direction of the slit 101 (i.e., towards the substrate 20 to be coated), thereby being discharged onto the substrate 20 to be coated.

[0063] The rear blade lip 120 and the front blade lip 110 are arranged in the direction that the coating die moves relative to the substrate 20 to be coated. In actual coating, the substrate 20 to be coated can remain stationary while the coating die moves; or the coating die can remain stationary while the substrate 20 to be coated moves, as long as relative movement occurs between the substrate 20 to be coated and the coating die. Figure 1 In the illustrated embodiment, the direction in which the coating die moves relative to the substrate 20 is specifically the OX' direction. The arrangement direction of the rear blade 120 and the front blade 110 is along the OX' direction of movement of the coating die relative to the substrate 20. That is, along the OX' direction of movement of the coating die relative to the substrate 20, the front blade 110 is in front of the rear blade 120. If the coating die remains stationary, the substrate 20 moves along the OX direction, i.e., the coating die moves relative to the substrate 20 along the OX' direction.

[0064] The depth direction of the slit 101 can be perpendicular to the arrangement direction of the rear blade 120 and the front blade 110.

[0065] exist Figure 1 In the illustrated embodiment, the second surface 121 is the side of the rear blade lip 120 facing the OZ' direction. The first surface 111 is the side of the front blade lip 110 facing the OZ' direction.

[0066] The first hydrophobic layer 310 can be a fluoropolymer coating, such as a coating of polyhexafluoropropylene, polytetrafluoroethylene, polyperfluoroethylene-propylene, polytrifluoroethylene, polyvinylidene fluoride, fluorosilicon resin, or the like. The first hydrophobic layer 310 can be disposed on the second face 121 by spraying, vacuum evaporation, or the like. The first hydrophobic layer 310 can also be a rough structure layer formed by spraying sand on the second face 121 to achieve a hydrophobic effect.

[0067] The first hydrophilic layer 210 can be a coating of a cross-linked polymer containing a hydrophilic group, such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacrylic acid, polydopamine, or the like. The first hydrophilic layer 210 can be disposed on the first face 111 by spraying, vacuum evaporation, or the like. Alternatively, the first hydrophilic layer 210 can be formed by ultraviolet-ozone treatment or plasma cleaning.

[0068] In actual coating, one side of the front blade lip 110 and the back blade lip 120 faces the substrate 20 to be coated, and the solution is discharged from the slit 101 between the front blade lip 110 and the back blade lip 120 to form a liquid film on the substrate 20 to be coated. During the coating process, the coating die moves relative to the substrate 20 to be coated, and the liquid film coated on the substrate 20 to be coated is formed behind the front blade lip 110. Therefore, the side of the back blade lip 120 facing the substrate 20 to be coated continuously passes through the liquid film. Since the second face 121 of the back blade lip 120 facing the substrate 20 to be coated is provided with the first hydrophobic layer 310, the first hydrophobic layer 310 is not easy to adhere to the solution, so that the solution is not easy to adhere to the back blade lip 120, thereby improving the problem of poor coating quality caused by solution adhesion as much as possible. On this basis, if the solution discharged from the slit 101 overflows between the front blade lip 110 and the substrate 20 to be coated, the first hydrophilic layer 210 provided on the first face 111 of the front blade lip 110 can adsorb the solution, so that the solution overflowing between the front blade lip 110 and the substrate 20 to be coated adheres to the first hydrophilic layer 210, thereby minimizing the mixing of air between the first hydrophilic layer 210 and the solution, and minimizing the mixing of air in the solution, thereby improving the phenomenon of liquid film rupture. Moreover, the mixing of air in the solution can be minimized to press the local position of the liquid film, thereby improving the uniformity of the liquid film.

[0069] In actual coating, if the relative movement speed of the coating die and the substrate 20 to be coated is inconsistent with the speed of the solution discharged from the slit 101, for example, when the speed of the solution discharged from the slit is too fast or the relative movement speed of the coating die and the substrate is too slow, the solution discharged from the slit 101 can accumulate too much between the back blade lip 120 and the substrate 20 to be coated. The accumulated solution can easily cause the liquid film to be too thick, and can also leak to the outside of the substrate 20 to be coated, causing waste. Therefore, please refer to Figures 2 to 5 , Figure 2Fig. 1 shows a schematic diagram of a coating die according to an embodiment of the present application, Figure 3 Fig. 2 shows a schematic diagram of a coating die according to another embodiment of the present application, Figure 4 Fig. 3 shows a schematic diagram of a coating die according to yet another embodiment of the present application, Figure 5 Fig. 4 shows a schematic diagram of a coating die according to still another embodiment of the present application.

[0070] In some embodiments, the second surface 121 is provided with a hydrophilic groove 1211. The first hydrophobic layer 310 is located on the side of the hydrophilic groove 1211 close to the slit 101. The coating die further comprises a second hydrophilic layer 320, which is provided on the groove wall of the hydrophilic groove 1211.

[0071] The second hydrophilic layer 320 can be a coating layer of a cross-linked polymer containing a hydrophilic group, such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacrylic acid, polydopamine, etc. The second hydrophilic layer 320 can be provided on the groove wall of the hydrophilic groove 1211 by spraying, vacuum evaporation, or the like. Alternatively, the second hydrophilic layer 320 can be formed by ultraviolet-ozone treatment, or plasma cleaning. The second hydrophilic layer 320 is provided on all or part of the groove wall of the hydrophilic groove 1211. The hydrophilic groove 1211 is concave from the second surface 121, forming a space for accommodating the solution.

[0072] If the relative movement speed of the coating die and the substrate 20 to be coated is inconsistent with the speed at which the solution is discharged from the slit 101, causing excessive accumulation of the solution discharged from the slit 101 between the trailing lip 120 and the substrate 20 to be coated, the solution can overflow into the hydrophilic groove 1211, and the second hydrophilic layer 320 on the groove wall of the hydrophilic groove 1211 has hydrophilicity, which can cause the solution to be adsorbed as much as possible in the hydrophilic groove 1211. Thus, the accumulation of the solution between the trailing lip 120 and the substrate 20 to be coated is reduced, thereby effectively reducing the situation of excessively thick liquid film, and reducing the situation of solution leakage.

[0073] Since the solution is discharged from the slit 101 and enters between the trailing lip 120 and the substrate 20 to be coated, the solution discharged from the slit 101 first passes through the first hydrophobic layer 310 and then passes through the hydrophilic groove 1211. In this embodiment, the first hydrophobic layer 310 is located on the side of the hydrophilic groove 1211 close to the slit 101, so that the excess solution is not easily adhered to the trailing lip 120 before entering the hydrophilic groove 1211 due to the presence of the first hydrophobic layer 310.

[0074] Please refer to Figures 2 to 5In some embodiments, the hydrophilic groove 1211 comprises a first groove wall 1211a and a second groove wall 1211b opposite to each other. One side of the first groove wall 1211a is connected with the second surface 121, and one side of the second groove wall 1211b is connected with the second surface 121. The first groove wall 1211a and the second groove wall 1211b are respectively provided with a second hydrophilic layer 320.

[0075] The first groove wall 1211a can be a plane or a curved surface. The second groove wall 1211b can be a plane or a curved surface.

[0076] Since one side of the first groove wall 1211a is connected with the second surface 121, and one side of the second groove wall 1211b is connected with the second surface 121, when the solution enters the hydrophilic groove 1211, it first contacts the first groove wall 1211a and the second groove wall 1211b. By respectively providing the first groove wall 1211a and the second groove wall 1211b with the second hydrophilic layer 320, the solution entering the hydrophilic groove 1211 can be quickly adsorbed by the second hydrophilic layer 320 on the first groove wall 1211a and the second groove wall 1211b, thereby quickly allowing the accumulated solution to enter the hydrophilic groove 1211. That is, the phenomenon of excessively thick liquid film and solution leakage caused by solution accumulation can be quickly and effectively improved.

[0077] Please refer to Figure 3 and Figure 4 In some embodiments, the side of the first groove wall 1211a away from the second surface 121 and the side of the second groove wall 1211b away from the second surface 121 are connected. The first groove wall 1211a and the second groove wall 1211b are arranged at an included angle.

[0078] Specifically in the embodiments shown in Figure 3 and Figure 4 , the first groove wall 1211a and the second groove wall 1211b are respectively inclined to the second surface 121. Either of the first groove wall 1211a and the second groove wall 1211b can also be perpendicular to the second surface 121. The included angle of the first groove wall 1211a and the second groove wall 1211b can be an acute angle, a right angle, or an obtuse angle.

[0079] Since the side of the first groove wall 1211a away from the second surface 121 and the side of the second groove wall 1211b away from the second surface 121 are connected, along the direction of the recess of the hydrophilic groove 1211 on the second surface 121, the distance between the first groove wall 1211a and the second groove wall 1211b gradually decreases, that is, the distance between the second hydrophilic layers 320 respectively provided on the first groove wall 1211a and the second groove wall 1211b decreases, so that the solution between the second hydrophilic layers 320 on the two groove walls can be reliably adsorbed.

[0080] Please refer to Figure 2 andFigure 5 In some embodiments, the groove wall of the hydrophilic groove 1211 includes a bottom wall 1211c, the first groove wall 1211a and the second groove wall 1211b are connected to two ends of the bottom wall 1211c respectively, and the bottom wall 1211c is provided with the second hydrophilic layer 320.

[0081] The bottom wall 1211c can be a plane or a curved surface, and can be parallel to the second surface 121 or inclined to the second surface 121. The first groove wall 1211a can be perpendicular to the second surface 121 or inclined to the second surface 121. The second groove wall 1211b can be perpendicular to the second surface 121 or inclined to the second surface 121. The first groove wall 1211a and the bottom wall 1211c can be perpendicular to each other or inclined to each other, and the second groove wall 1211b and the bottom wall 1211c can be perpendicular to each other or inclined to each other. The second hydrophilic layer 320 of the bottom wall 1211c can adsorb the solution, so that the solution can be reliably contained in the hydrophilic groove 1211.

[0082] In the present embodiment, by connecting the first groove wall 1211a and the second groove wall 1211b to two ends of the bottom wall 1211c respectively, the hydrophilic groove 1211 thus configured (compared with the hydrophilic groove shown in FIG. 1) has a larger capacity and can contain more solution, thereby better improving the phenomenon of over-thick liquid film and solution leakage caused by solution accumulation. Figure 3 And Figure 4 The hydrophilic groove shown in FIG. 1) has a larger capacity and can contain more solution, thereby better improving the phenomenon of over-thick liquid film and solution leakage caused by solution accumulation.

[0083] Please refer to Figures 2 to 5 In an embodiment, the ratio α of the size of the hydrophilic groove 1211 along the first direction PP' to the size of the second surface 121 along the first direction PP' satisfies the condition: 4 / 15≤α≤2 / 5. The ratio β of the size of the hydrophilic groove 1211 along the second direction QQ' to the size of the hydrophilic groove 1211 along the first direction PP' satisfies the condition: 5 / 2≤β≤15 / 4. Wherein, the first direction PP' is along the direction in which the first groove wall 1211a and the second groove wall 1211b face each other, and the second direction QQ' is perpendicular to the second surface 121.

[0084] Specifically, the ratio α of the size of the hydrophilic groove 1211 along the first direction PP' to the size of the second surface 121 along the first direction PP' can be 4 / 15, 1 / 3, 2 / 5, or any other value in the above range (4 / 15≤α≤2 / 5). The ratio β of the size of the hydrophilic groove 1211 along the second direction QQ' to the size of the hydrophilic groove 1211 along the first direction PP' can be 5 / 2, 3, 15 / 4, or any other value in the above range (5 / 2≤β≤15 / 4).

[0085] By the size design of the hydrophilic groove 1211, the amount of the solution generated by the conventional coating can be accommodated by the hydrophilic groove 1211, so that the liquid film over-thickness and solution leakage caused by solution accumulation can be effectively improved.

[0086] Please refer to Figure 6 , Figure 6 The structure diagram of the coating die coating solution to the substrate to be coated is shown. In some embodiments, the coating die further comprises a second hydrophobic layer 330, which is arranged on the second surface 121, and the second hydrophobic layer 330 is located on the side of the hydrophilic groove 1211 away from the first hydrophobic layer 310.

[0087] The second hydrophobic layer 330 can be a fluoropolymer coating, such as a coating of polyhexafluoropropylene, polytetrafluoroethylene, polyperfluoroethylene, polytrifluoroethylene, polyvinylidene fluoride, fluorosilicon resin, etc. The second hydrophobic layer 330 can be arranged on the second surface 121 by spraying, vacuum evaporation, etc. The second hydrophobic layer 330 can also be a rough structure layer formed by spraying sand on the second surface 121, thereby achieving the hydrophobic effect.

[0088] Since the second hydrophobic layer 330 is located on the side of the hydrophilic groove 1211 away from the first hydrophobic layer 310, that is, the first hydrophobic layer 310 and the second hydrophobic layer 330 are respectively located on both sides of the hydrophilic groove 1211, so that after the accumulated solution enters the hydrophilic groove 1211, the second surface 121 can also resist the adhesion of the solution through the hydrophobic layers on both sides of the hydrophilic groove 1211, thereby further reducing the adhesion of the solution on the back lip 120.

[0089] Since the solution is discharged from the slit 101 and enters between the back lip 120 and the substrate to be coated 20, the solution discharged from the slit 101 first passes through the first hydrophobic layer 310, then passes through the hydrophilic groove 1211, and then passes through the second hydrophobic layer 330. Since the hydrophilic groove 1211 can accommodate the accumulated solution, the phenomenon of liquid film over-thickness and solution leakage can be reduced on the side of the hydrophilic groove 1211 away from the slit 101, and the solution is not easy to adhere to the second surface 121 on the side of the hydrophilic groove 1211 away from the slit 101, so the second hydrophobic layer 330 can also not be arranged on the side of the hydrophilic groove 1211 away from the slit 101 on the second surface 121 (such as Figures 2 to 5 ).

[0090] Please refer to Figure 1 , Figure 6 and Figure 7 , Figure 7A schematic diagram of a coating die applying a solution to a substrate to be coated is shown. In some embodiments, the trailing lip 120 has a third face 122 facing away from the leading lip 110. The coating die further comprises a third hydrophobic layer 340 disposed on the third face 122.

[0091] The third hydrophobic layer 340 covers all or part of the third face 122. Specifically, the third hydrophobic layer 340 can be a coating of a fluoropolymer, such as a coating of polyhexafluoropropylene, polytetrafluoroethylene, polyperfluoroethylene propylene, polytrifluoroethylene, polyvinylidene fluoride, fluorosilicone resin, etc. The third hydrophobic layer 340 can be disposed on the third face 122 by spraying, vacuum evaporation, etc. The third hydrophobic layer 340 can also be a rough structure layer formed on the third face 122 by spraying sand, thereby achieving a hydrophobic effect.

[0092] By disposing the third hydrophobic layer 340, the solution can be minimized to adhere to the third face 122 of the trailing lip 120 facing away from the leading lip 110, thereby improving the coating quality problem caused by solution adhesion.

[0093] Optionally, the third hydrophobic layer 340 extends to a side edge of the third face 122 close to the second face 121, so that the third hydrophobic layer 340 can be as close as possible to the substrate to be coated 20, i.e. as close as possible to the solution, and thus the third hydrophobic layer 340 can sufficiently and effectively reduce the solution adhering to the side edge of the third face 122 of the trailing lip 120 close to the second face 121.

[0094] Please refer to Figure 1 and Figure 7 In some embodiments, the third hydrophobic layer 340 is connected to the first hydrophobic layer 310. The end of the third hydrophobic layer 340 close to the second face 121 is connected to the end of the first hydrophobic layer 310 away from the slit 101, so that the connection between the third hydrophobic layer 340 and the first hydrophobic layer 310 can wrap the connection between the second face 121 and the third face 122, and thus the third hydrophobic layer 340 and the first hydrophobic layer 310 can sufficiently cover the second face 121 and the third face 122 and the connection between the two faces, and sufficiently and effectively reduce the solution adhering to the trailing lip 120.

[0095] Please refer to Figure 6 In some embodiments, the coating die further comprises a second hydrophobic layer 330 disposed on the second face 121, and the second hydrophobic layer 330 is located on the side of the hydrophilic groove 1211 away from the first hydrophobic layer 310. The third hydrophobic layer 340 is connected to the second hydrophobic layer 330.

[0096] Specifically, the third hydrophobic layer 340 is connected to the second hydrophobic layer 330 at an end of the second hydrophobic layer 330 away from the hydrophilic groove 1211, so that the connection between the third hydrophobic layer 340 and the second hydrophobic layer 330 can wrap the connection between the second face 121 and the third face 122, thereby effectively reducing the adhesion of the solution to the trailing lip 120.

[0097] Please refer to Figure 2 , Figure 6 and Figure 7 , Figure 7 The structure of the coating die of some embodiments of the present application is shown in the schematic diagram of the solution coating on the substrate to be coated. In some embodiments, the coating die further comprises a fourth hydrophobic layer 220, which is arranged on the first face 111. The first hydrophilic layer 210 is arranged on the side of the fourth hydrophobic layer 220 close to the slit 101.

[0098] The fourth hydrophobic layer 220 can be a fluoropolymer coating, such as a coating of polyhexafluoropropylene, polytetrafluoroethylene, polyperfluoroethylene propylene, polytrifluoroethylene, polyvinylidene fluoride, fluorosilicon resin, etc. The fourth hydrophobic layer 220 can be arranged on the first face 111 by spraying, vacuum evaporation, etc. The fourth hydrophobic layer 220 can also be a rough structure layer formed by spraying sand on the first face 111, thereby achieving the effect of hydrophobicity.

[0099] Since the first hydrophilic layer 210 is arranged on the side of the fourth hydrophobic layer 220 close to the slit 101, that is, in the actual coating process, the fourth hydrophobic layer 220 is in front of the first hydrophilic layer 210.

[0100] If the solution discharged from the slit 101 overflows between the trailing lip 110 and the substrate to be coated 20, the first hydrophilic layer 210 (compared to the fourth hydrophobic layer 220) will first contact the solution, and the first hydrophilic layer 210 will be in close contact with the overflowing solution, reducing the mixing of air into the solution and improving the phenomenon of liquid film rupture and the uniformity of the liquid film.

[0101] Since the fourth hydrophobic layer 220 is in front of the first hydrophilic layer 210, if the solution overflowing between the trailing lip 110 and the substrate to be coated 20 is less, the fourth hydrophobic layer 220 may not contact the solution. If the solution overflowing between the trailing lip 110 and the substrate to be coated 20 is more, the solution may overflow between the fourth hydrophobic layer 220 and the substrate to be coated 20, and the fourth hydrophobic layer 220 is not easy to adhere to the solution, thereby making it difficult for the solution to adhere to the trailing lip 110, and further improving the problem of poor coating quality caused by the adhesion of the solution.

[0102] Further, please refer to Figure 2 , Figure 6 and Figure 7In some embodiments, the fourth hydrophobic layer 220 covers less area of the first face 111 than the first hydrophilic layer 210.

[0103] Specifically, the fourth hydrophobic layer 220 can have a dimension along the arrangement direction of the front blade lip 110 and the back blade lip 120 that is less than the dimension of the first hydrophilic layer 210 along the arrangement direction of the front blade lip 110 and the back blade lip 120.

[0104] As the first hydrophilic layer 210 covers a larger area, the solution that overflows between the front blade lip 110 and the substrate 20 to be coated has a larger area of adhesion to the first hydrophilic layer 210, thereby stabilizing the form of the solution between the front blade lip 110 and the substrate 20 to be coated, and further improving the coating quality.

[0105] For reference Figure 1 In some embodiments, the fourth hydrophobic layer 220 is not provided in front of the first hydrophilic layer 210 on the first face 111, so that the area of the first face 111 for providing the first hydrophilic layer 210 is larger. The first hydrophilic layer 210 can cover most or even all of the area of the first face 111.

[0106] As the first hydrophilic layer 210 covers a larger area, the solution that overflows between the front blade lip 110 and the substrate 20 to be coated has a larger area of adhesion to the first hydrophilic layer 210, thereby stabilizing the form of the solution between the front blade lip 110 and the substrate 20 to be coated, and further improving the coating quality.

[0107] For reference Figures 1 to 7 In some embodiments, the front blade lip 110 has a fourth face 112 facing away from the back blade lip 120. The coating die further comprises a fifth hydrophobic layer 230 provided on the fourth face 112.

[0108] The fifth hydrophobic layer 230 covers all or part of the area of the fourth face 112. Specifically, the fifth hydrophobic layer 230 can be a coating layer of a fluoropolymer, such as a coating layer of polyhexafluoropropylene, polytetrafluoroethylene, polyperfluoroethylene propylene, polytrifluoroethylene, polyvinylidene fluoride, fluorosilicon resin, etc. The fifth hydrophobic layer 230 can be provided on the fourth face 112 by spraying, vacuum evaporation, etc. The fifth hydrophobic layer 230 can also be a rough structure layer formed on the fourth face 112 by spraying corundum, thereby achieving a hydrophobic effect.

[0109] By providing the fifth hydrophobic layer 230, the adhesion of the solution to the fourth face 112 of the front blade lip 110 facing away from the back blade lip 120 can be minimized, thereby improving the coating quality problem caused by the adhesion of the solution.

[0110] Optionally, the fifth hydrophobic layer 230 extends to the side edge of the fourth face 112 close to the first face 111 at one end of the first face 111, so that the fifth hydrophobic layer 230 can be as close as possible to the substrate 20 to be coated, i.e. as close as possible to the solution, and thus the fifth hydrophobic layer 230 can sufficiently and effectively reduce the adhesion of the solution to the side edge of the fourth face 112 close to the first face 111 of the front lip 110.

[0111] Please refer to Figure 6 and Figure 7 In some embodiments, the coating die further comprises a fourth hydrophobic layer 220 arranged on the first face 111. The first hydrophilic layer 210 is arranged on the side of the fourth hydrophobic layer 220 close to the slit 101. The fifth hydrophobic layer 230 is connected to the fourth hydrophobic layer 220.

[0112] Specifically, one end of the fifth hydrophobic layer 230 close to the first face 111 is connected to the end of the fourth hydrophobic layer 220 away from the first hydrophilic layer 210, so that the connection between the fifth hydrophobic layer 230 and the fourth hydrophobic layer 220 can wrap the connection between the first face 111 and the fourth face 112, and thus the fifth hydrophobic layer 230 and the fourth hydrophobic layer 220 can sufficiently cover the first face 111, the fourth face 112 and the connection between the two, and sufficiently and effectively reduce the adhesion of the solution to the front lip 110.

[0113] Please refer to Figures 1 to 3 In some embodiments, the second face 121 is coplanar with the first face 111, i.e. located on the same virtual plane.

[0114] In other embodiments, the second face 121 and the first face 111 can also be arranged in parallel, for example, the second face 121 and the first face 111 have a height difference in the depth direction of the slit 101 and are arranged in parallel.

[0115] Please refer to Figure 4 and Figure 5 In some embodiments, the second face 121 and the first face 111 form an angle between the planes on which they are located. In the direction of the coating die towards the substrate 20 to be coated, the distance between the second face 121 and the first face 111 gradually expands.

[0116] The angle between the second face 121 and the first face 111 can be an acute angle, and is not limited to be a right angle or an obtuse angle. Since the distance between the second face 121 and the first face 111 gradually expands in the direction of the coating die towards the substrate 20 to be coated, the space between the second face 121 and the first face 111 has a larger capacity for containing the solution. In this embodiment, the second face 121 and the first face 111 are inclined towards the substrate 20 to be coated.

[0117] The arrangement of the second surface 121 of the coating die and the first surface 111 is suitable for a solution with high viscosity. The solution with high viscosity has a low flow rate, and thus a large injection pressure is required to inject the solution into the coating die, and the solution is injected at a high speed. The solution injected at a high speed can be buffered when passing through the narrow slit 101 and entering the space between the second surface 121 and the first surface 111, and the turbulence of the solution is reduced, thereby improving the film forming effect.

[0118] In an embodiment of the present application, a coating device is also provided, which comprises a driving mechanism and the coating die according to any one of the above embodiments, and the driving mechanism is used to drive the coating die or the substrate to be coated to move relative to each other.

[0119] The specific structure of the driving mechanism can refer to the prior art, and will not be described here.

[0120] In actual coating, one side of the front blade lip 110 and the rear blade lip 120 faces the substrate 20 to be coated, and the solution is discharged from the slit 101 between the front blade lip 110 and the rear blade lip 120 to form a liquid film on the substrate 20 to be coated. During the coating process, the coating die and the substrate 20 to be coated move relative to each other, and the liquid film coated on the substrate 20 to be coated is formed behind the front blade lip 110, and thus the side of the rear blade lip 120 facing the substrate 20 to be coated will continuously pass through the liquid film. The second surface 121 of the rear blade lip 120 facing the substrate 20 to be coated is provided with the first hydrophobic layer 310, and the first hydrophobic layer 310 is not easy to adhere to the solution, so that the solution is not easy to adhere to the rear blade lip 120, thereby improving the problem of poor coating quality caused by the adhesion of the solution as much as possible. If the solution discharged from the slit 101 overflows between the front blade lip 110 and the substrate 20 to be coated, the first hydrophilic layer 210 arranged on the first surface 111 of the front blade lip 110 can adsorb the solution, so that the solution overflowing between the front blade lip 110 and the substrate 20 to be coated is tightly attached to the first hydrophilic layer 210, thereby reducing the air mixed between the first hydrophilic layer 210 and the solution as much as possible, and further reducing the air mixed in the solution, and improving the phenomenon of liquid film rupture. Moreover, the air mixed in the solution can be pressed as much as possible to the local position of the liquid film, thereby improving the uniformity of the liquid film.

[0121] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A coating die characterized by, The coating die comprises: a rake lip having a first face facing a substrate to be coated; a flank lip having a second face facing the substrate to be coated, the flank lip being spaced apart from the rake lip to define a slit; and a first hydrophilic layer provided on the first face and a first hydrophobic layer provided on the second face.

2. The coating die according to claim 1, wherein: the second face is provided with a hydrophilic groove; and the first hydrophobic layer is located on a side of the hydrophilic groove close to the slit. The coating die further comprises a second hydrophilic layer provided on a groove wall of the hydrophilic groove.

3. The coating die according to claim 2, wherein: the hydrophilic groove comprises a first groove wall and a second groove wall opposite to each other; and the first groove wall and the second groove wall are respectively provided with the second hydrophilic layer.

4. The coating die according to claim 3, wherein: a side of the first groove wall away from the second face is connected with a side of the second groove wall away from the second face; and 5. The coating die of claim 3, wherein the first groove wall and the second groove wall are arranged at an included angle. The hydrophilic groove further comprises a bottom wall connected between the first groove wall and the second groove wall; and the bottom wall is provided with the second hydrophilic layer.

6. The coating die according to claim 5, wherein: a ratio α of a size of the hydrophilic groove along a first direction to a size of the second face along the first direction satisfies a condition of 4 / 15≤α≤2 / 5; 7. The coating die of claim 3, wherein a ratio β of a size of the hydrophilic groove along a second direction to a size of the hydrophilic groove along the first direction satisfies a condition of 5 / 2≤β≤15 / 4; 8. The coating die of any one of claims 1-7, wherein, wherein the first direction is along a direction in which the first groove wall and the second groove wall face each other, and the second direction is perpendicular to the second face. The coating die further comprises a second hydrophobic layer provided on the second face, the second hydrophobic layer being located on a side of the hydrophilic groove away from the first hydrophobic layer.

9. The coating die of any one of claims 1-7, wherein, The flank lip has a third face facing away from the rake lip.

10. The coating die of any one of claims 1-7, wherein, The coating die further comprises a third hydrophobic layer provided on the third face.

11. The coating die of any one of claims 1-7, wherein, The coating die further comprises a fourth hydrophobic layer provided on the first face, the first hydrophilic layer being located on a side of the fourth hydrophobic layer close to the slit.

12. The coating die of any one of claims 1-7, wherein, The rake lip has a fourth face facing away from the flank lip; and The coating die further comprises a fifth hydrophobic layer provided on the fourth face.

13. A coating apparatus characterized by comprising: The second face is parallel to or coplanar with the first face. The second face is located at an included angle with the first face. Wherein, in a direction of the coating die facing the substrate to be coated, a distance between the second face and the first face gradually increases. A drive mechanism for driving the coating die or the substrate to be coated to move so as to relatively move the coating die and the substrate to be coated.

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