A non-polar solution assisted slot die and slot coating method

Abstract

The application discloses a non-polar solution assisted slot coating die and a slot coating method, wherein the non-polar solution assisted slot coating die comprises a first die body, a first injection cavity arranged on the side close to a lip, and a second injection cavity arranged on the side away from the lip, and the first injection cavity is arranged at intervals with the second injection cavity; a second die body; and a gasket clamped between the first die body and the second die body and located on the side away from the lip, so that the lip forms a coating gap. By arranging the first injection cavity on the side close to the lip of the first die body and the second injection cavity arranged at intervals on the side away from the lip, when the gasket is clamped on the first die body and the second die body, the side away from the lip is corresponded, and when the coating slot is coated, the non-polar solution in the second injection cavity forms isolation for the coating solution and the gasket, the non-polar solution is extruded and sucked to push and supplement the coating solution, and the contact between the coating solution and the gasket can be prevented, so that the gasket is protected.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a non-polar solution-assisted slit coating die and slit coating method. Background Technology

[0002] Slot coating heads are key components widely used in perovskite or optoelectronic solution coating machinery. The formulated solution, after being pressurized by an injection pump through the internal cavity of the slot coating head, is ejected from the outlet and uniformly coated onto the substrate surface. In the perovskite slot coating process, the perovskite solution is uniformly extruded onto the substrate through the gap between the upper and lower dies. This gap value is controlled by placing spacers of different thicknesses between the upper and lower dies, typically 50 micrometers. During the coating process, after entering the die head, the solution preferentially fills the flow channels within the die head cavity, finally filling the space between the upper and lower dies, and is extruded under continuous injection pressure.

[0003] Because perovskite solution is corrosive, it will come into contact with the gasket in the corresponding gap during the filling process of the perovskite solution in the mold head. Under the pressure of continuous injection, the perovskite solution will penetrate and remain in the contact surface between the gasket and the upper and lower molds, causing corrosion to the gasket.

[0004] In existing technologies, methods to solve the corrosion of perovskite solutions include cleaning the die head with a cleaning agent and then blowing compressed air into the die head to blow out the residual liquid, or manually disassembling and cleaning the die head. However, due to the complex flow channels inside the die head, compressed air can easily cause the residual liquid to dry and is difficult to completely remove. Disassembling and cleaning the die head is time-consuming and laborious, and repeated calibration is required when assembling the die head to restore the coating state.

[0005] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0006] To address the problems in existing technologies where cleaning the perovskite solution on the gasket of the cleaning die head involves using cleaning agents and then blowing out the residual liquid with compressed air, which can easily cause the perovskite solution to dry out and make it difficult to completely remove the residual liquid, and where disassembling the die head for cleaning can achieve complete cleaning, but requires repeated calibration during assembly, which is time-consuming and labor-intensive, this invention provides a perovskite solution slot coating nozzle and slot coating method.

[0007] This invention is achieved through the following technical solution: A non-polar solution-assisted slit coating die, wherein the non-polar solution-assisted slit coating die comprises: The first mold body includes a first injection cavity disposed near the lip, the first injection cavity being used to inject a coating solution; and a second injection cavity disposed away from the lip, the second injection cavity being used to inject a non-polar solution, the first injection cavity and the second injection cavity being disposed at an interval. The second mold body is detachably fastened to one side of the first mold body; A gasket is sandwiched between the first mold body and the second mold body and is located on the side away from the lip opening, so that the lip opening forms a coating gap.

[0008] The non-polar solution-assisted slit coating die head includes a gasket with extensions at both ends, the extensions protruding towards the lip side, and a limiting groove corresponding to the position of the second injection cavity formed between the two extensions. The limiting groove is used to restrict the extrusion direction of the non-polar solution.

[0009] The non-polar solution-assisted slit coating die head, wherein the limiting groove includes two clearance portions corresponding to the two ends of the second injection cavity, and the clearance portions are semi-circular; The second injection cavity is provided with exhaust holes that extend out of the first mold body at both ends, and the two exhaust holes correspond to the positions of the two relief portions respectively.

[0010] The non-polar solution-assisted slit coating die head, wherein the first injection cavity includes a first channel extending through the upper end of the first die body, and the first channel is tightly connected to the coating injection device; The second injection cavity includes a second channel extending from the upper end of the first mold body, and the second channel is tightly connected to a non-polar injection device.

[0011] The non-polar solution-assisted slit coating die head is driven by a vertical motion mechanism. A coating platform is provided on the lower side of the non-polar solution-assisted slit coating die head. The coating platform is driven by a horizontal motion mechanism. A coating substrate and a sealing strip located on one side of the coating substrate are provided on the coating platform. The shape of the sealing strip is adapted to the shape of the lip.

[0012] A slit coating method, applied to the aforementioned non-polar solution-assisted slit coating die, the slit coating method comprising: After injecting a coating solution into the first injection chamber and a non-polar solution into the second injection chamber, the non-polar solution in the second injection chamber is pushed into the first injection chamber so that the coating solution in the first injection chamber flows out from the lip opening to perform the first coating. The coating solution is injected into the first injection cavity so that the non-polar solution in the first injection cavity returns to the second injection cavity. Then, the non-polar solution in the second injection cavity is pushed into the first injection cavity so that the coating solution in the first injection cavity flows out from the lip for the next coating.

[0013] The slit coating method, wherein injecting the coating solution into the first injection cavity and injecting the non-polar solution into the second injection cavity comprises: Press the lip opening and the sealing strip together to isolate the air in the gap of the lip opening; After injecting a coating solution into the first injection cavity, a non-polar solution is then injected into the second injection cavity; wherein, when the coating solution is injected into the first injection cavity, the coating solution fills the first injection cavity and the gap at the lip; when the non-polar solution is injected into the second injection cavity, the non-polar solution fills the second injection cavity and the gap between the first injection cavity and the second injection cavity.

[0014] In the slit coating method, when a coating solution is injected into the first injection chamber, air in the slit between the first injection chamber and the lip is discharged through an exhaust port located in the second injection chamber.

[0015] The slit coating method, wherein pushing the non-polar solution from the second injection chamber into the first injection chamber to allow the coating solution in the first injection chamber to flow out from the lip for the first coating includes: Separate the lip from the sealing strip and move the coated substrate to below the lip; Locking coating injection device; Applying pressure to the nonpolar injection device pushes the nonpolar solution in the second injection chamber into the first injection chamber, so that the coating solution in the first injection chamber flows out from the lip to perform the first coating.

[0016] The slit coating method, wherein injecting the coating solution into the first injection cavity to cause the non-polar solution in the first injection cavity to return to the second injection cavity comprises: Unlock the coating injection device; A pushing pressure is applied to the coating injection device to inject the coating solution into the first injection chamber, and a pumping pressure is applied to the non-polar injection device to cause the non-polar solution in the first injection chamber to return to the second injection chamber.

[0017] The beneficial effects of the present invention are as follows: By setting a first injection cavity on the side of the first mold body near the lip and setting a second injection cavity at intervals on the side away from the lip, the gasket is clamped on the side away from the lip when it is attached to the first mold body and the second mold body. When coating the slit, the non-polar solution in the second injection cavity isolates the coating solution and the gasket. The non-polar solution pushes and replenishes the coating solution by squeezing and suction, which can prevent the coating solution from contacting the gasket and protect the gasket. Attached Figure Description

[0018] Figure 1 This is a schematic diagram showing the usage state of the non-polar solution-assisted slit coating die head of the present invention; Figure 2 This is a schematic diagram of the disassembled structure of the non-polar solution-assisted slit coating die head of the present invention; Figure 3 This is a schematic cross-sectional view of the first mold body in the non-polar solution-assisted slit coating die head of the present invention; Figure 4 This is a schematic diagram of the end face structure of the first mold body in the non-polar solution-assisted slit coating die head of the present invention; Figure 5 This is a schematic diagram of the combined state of the non-polar solution-assisted slit coating die head of the present invention; Figure 6 This is a schematic diagram of the gasket structure in the non-polar solution-assisted slit coating die of the present invention; Figure 7 This is a flowchart of the slit coating method of the present invention.

[0019] exist Figures 1 to 7 In the middle: 10, first mold body; 11, first injection cavity; 12, second injection cavity; 13, lip; 14, first channel; 15, second channel; 16, vent hole; 20, second mold body; 30, gasket; 31, extension; 32, limiting groove; 33, clearance part; 40, coating injection device; 50, non-polar injection device; 60, coating platform; 61, coating substrate; 62, sealing strip. Detailed Implementation

[0020] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] In existing technologies, methods to solve the corrosion of perovskite solutions include cleaning the die head with a cleaning agent and then blowing compressed air into the die head to blow out the residual liquid, or manually disassembling and cleaning the die head. However, due to the complex flow channels inside the die head, compressed air can easily cause the residual liquid to dry and is difficult to completely remove. Disassembling and cleaning the die head is time-consuming and laborious, and repeated calibration is required when assembling the die head to restore the coating state.

[0024] To address the aforementioned problems in the prior art, this invention provides a non-polar solution-assisted slit coating die, such as... Figure 1 As shown, the non-polar solution-assisted slit coating die head includes: a first die body 10, including a first injection cavity 11 disposed near the lip 13, the first injection cavity 11 being used to inject a coating solution; and a second injection cavity 12 disposed away from the lip 13, the second injection cavity 12 being used to inject a non-polar solution, the first injection cavity 11 and the second injection cavity 12 being spaced apart; a second die body 20, detachably fastened to one side of the first die body 10; and a gasket 30, the gasket 30 being sandwiched between the first die body 10 and the second die body 20, and located on the side away from the lip 13, so that the lip 13 forms a coating slit.

[0025] The present invention provides a first injection cavity 11 on the side of the first mold 10 near the lip 13 and a second injection cavity 12 spaced apart on the side away from the lip 13. When the gasket 30 is clamped on the first mold 10 and the second mold 20, it corresponds to the side away from the lip 13. When coating the slit, the non-polar solution in the second injection cavity 12 isolates the coating solution and the gasket 30. The non-polar solution pushes and replenishes the coating solution by squeezing and suction, which can prevent the coating solution from contacting the gasket 30 and protect the gasket 30.

[0026] In the above embodiments, such as Figure 1 , Figure 2 and Figure 4As shown, the main body of the non-polar solution-assisted slit coating die head of the present invention consists of a first die body 10, a second die body 20, and a gasket 30. The first die body 10 and the second die body 20 are respectively the upper and lower dies in a slit coating head in the prior art. The gasket 30 is sandwiched between the first die body 10 and the second die body 20 (e.g., ...). Figure 5 As shown), the thickness of the gasket 30 creates a predetermined distance between the first mold body 10 and the second mold body 20, thereby creating a gap of predetermined distance at the lip 13 of the first mold body 10 and the second mold body 20 for use as a coating port.

[0027] Specifically, the difference between this application and the prior art lies in that a first injection cavity 11 is provided on the side of the first mold body 10 near the lip 13, which is used to inject the coating solution in actual use; a second injection cavity 12 is provided on the side of the first mold body 10 away from the lip 13, which is used to inject a non-polar solution in actual use; the first injection cavity 11 and the second injection cavity 12 are arranged at a certain distance apart. In fact, as... Figure 2 and Figure 4 As shown, the first mold 10 and the second mold 20 have a certain length. Therefore, when the first injection cavity 11 and the second injection cavity 12 are actually set, they are preferably set along the length direction of the first mold 10 and parallel to the edge of the lip 13. The advantage of this setting is that when the non-polar solution is squeezed to form a coating solution and flows out from the lip 13, it can ensure that the coating solution is uniformly coated along the length direction of the first mold 10, preventing uneven coating thickness. At the same time, it is also convenient to control the movement distance of the non-polar solution, so as to achieve precise control of the coating solution extrusion and filling process.

[0028] In this embodiment, the coating solution can specifically be a perovskite solution. When the perovskite solution is uniformly coated on the substrate, it forms capillary coating beads, enabling precise and controllable wet film deposition. This supports large-area continuous manufacturing, and nanoscale thickness control can be achieved by controlling parameters such as pump speed, coating speed, and slit gap. However, due to the characteristics of the perovskite solution, it is also corrosive to corrosion-resistant materials such as SUS630. Therefore, if the residual perovskite solution adhering to the gasket 30 cannot be effectively removed, the gasket 30 will gradually corrode, causing a decrease in precision and affecting the accuracy of the slit dimensions. The non-polar solution can specifically be a toluene solution. As a non-polar solution, toluene solution exhibits a layering effect with the perovskite solution. It is immiscible and non-corrosive, and will not corrode the gasket 30 or the die head. When toluene solution is used as a non-polar solution in the non-polar solution-assisted slit coating die of the present invention, the toluene solution isolates the gasket 30 and the perovskite solution, effectively avoiding the problem that the perovskite solution is difficult to clean and causes corrosion on the surface of the gasket 30. In practical applications, since the problem of cleaning the perovskite solution is avoided, there is no need to disassemble and clean the die, which greatly facilitates the slit coating process and effectively improves work efficiency.

[0029] In the above embodiments, this application does not limit the selection of coating solution and non-polar solution. Those skilled in the art can select other solution systems for slot coating scenarios according to actual usage needs and the working principle of non-polar solution, and this application does not limit this.

[0030] In this embodiment, the second mold body 20 is fastened to one side of the first mold body 10, clamping the gasket 30. It can be assembled and fixed using screws through the mold closing screw holes, and further assembled with the operating machine through screws through the back plate mounting holes and the mold lifting screw holes. Figure 1 and Figure 2 As shown, the gasket 30 is located on the side away from the lip 13, so that the lip 13 forms a coating gap. Specifically, the main body of the gasket 30 is located on the upper side of the second injection cavity 12, so that after the non-polar solution is injected into the second injection cavity 12, it forms a protective covering on the gasket 30 and the gaps on both sides of the gasket 30, thereby achieving the effect of preventing the coating solution from contacting and corroding the gasket 30.

[0031] In another possible embodiment of the invention, such as Figure 2 and Figure 6As shown, the gasket 30 also includes extensions 31 at both ends in actual installation. The extensions 31 protrude towards the lip 13 to limit the left, right and top sides of the second injection cavity 12. That is, a limiting groove 32 corresponding to the position of the second injection cavity 12 is formed between the two extensions 31. When the non-polar solution in the second injection cavity 12 increases, the non-polar solution can only be squeezed and coated along the preset path, that is, towards the lip 13, due to the limiting effect formed by the gasket 30 body and the two extensions 31, and will not diffuse in other directions, thereby ensuring the stability and accuracy of the coating process.

[0032] Furthermore, during the injection of the coating solution into the first injection cavity 11 and the injection of the non-polar solution into the second injection cavity 12, the coating solution, after filling the first injection cavity 11, distributes to the slit at the lip 13 and to the gap between the first injection cavity 11 and the second injection cavity 12; the non-polar solution, after filling the first injection cavity 11, distributes to the gasket 30 and to the gap between the first injection cavity 11 and the second injection cavity 12, and finally comes into contact with the coating solution. During this process, to prevent air bubbles from forming between the coating solution and the non-polar solution and affecting the coating accuracy, in this embodiment, further... Vent holes 16 are provided at both ends of the second injection cavity 12. The vent holes 16 extend out of the outer side wall of the first mold body 10. Correspondingly, clearance portions 33 are provided at both ends of the limiting groove 32. The clearance portions 33 correspond to the positions of the vent holes 16 at both ends of the second injection cavity 12, and the clearance portions 33 are semi-circular. When a non-polar solution is injected into the second injection cavity 12, the air in the cavity can be discharged through the vent holes 16. Thus, when the coating solution and non-polar solution are injected into the non-polar solution assisted slit coating mold head for the first time, the situation where residual air bubbles in the mold head affect the coating accuracy can be avoided.

[0033] In another possible embodiment of the invention, such as Figure 1 , Figure 3 and Figure 4As shown, to achieve accurate control of injecting coating solution into the first injection chamber 11 and injecting non-polar solution into the second injection chamber 12, in this embodiment, the first injection chamber 11 also includes a first channel 14 extending from the upper end of the first mold body 10. The first channel 14 is tightly connected to the coating injection device 40 disposed externally. The coating injection device 40 can be controlled by a servo motor to accurately control the injection volume and the timing of injection and stopping of injection of the coating solution through a predetermined program. Correspondingly, the second injection chamber 12 also includes a second channel 15 extending from the upper end of the second mold body 20. The second channel 15 is tightly connected to the non-polar injection device 50 disposed externally. The non-polar injection device 50 is also controlled by a servo motor to accurately control the injection volume and the timing of injection, stopping of injection and suction of the non-polar solution through a predetermined program. Thus, it can cooperate with the coating injection device 40 to achieve continuous replenishment of coating solution during the coating process and improve the efficiency of replenishing coating solution.

[0034] Furthermore, to achieve auxiliary control during the injection of coating solutions and non-polar solutions, and to achieve automated auxiliary control of the slit coating process, such as... Figure 1 As shown, in this embodiment, the non-polar solution-assisted slit coating die is driven by a vertical motion mechanism. This vertical motion mechanism and the coating die can be combined via screws in the backplate mounting holes and screws in the lifting screw holes, etc., to achieve the effect of moving the non-polar solution-assisted slit coating die through the vertical motion mechanism, or adjusting the non-polar solution-assisted slit coating die (such as adjusting horizontality, tilt angle, etc.) through additional functional components. A coating platform is provided on the lower side of the non-polar solution-assisted slit coating die. 60. The coating platform 60 is driven by a horizontal motion mechanism. A coating substrate 61 and a sealing strip 62 located on one side of the coating substrate 61 are provided on the coating platform 60. In actual use, the coating platform 60 is driven by the horizontal motion mechanism, which can achieve the effect of aligning a specific position of the coating substrate 61 or the sealing strip 62 with the lip 13. In conjunction with the vertical motion mechanism on the non-polar solution-assisted slit coating die head, the distance and position between the lip 13 and the coating platform 60 can be controlled to meet the needs of automated coating.

[0035] Specifically, the shape of the sealing strip 62 is adapted to the shape of the lip 13. The sealing strip 62 is made of soft silicone, rubber and other materials. When the coating solution is injected into the first injection cavity 11 for the first time, the vertical movement mechanism can make the lip 13 fit with the sealing strip 62 to seal the lip 13 and achieve the function of isolating air and smoothing the coating solution. When the lip 13 and the sealing strip 62 are fitted together, when the non-polar solution is injected into the second injection cavity 12 for the first time, the limiting effect of the lip 13 can ensure that the liquid pressure in the non-polar solution assisted slit coating die head is directed towards the second injection cavity 12. Thus, after the non-polar solution is injected, the air can be squeezed to the vent hole 16 to be discharged. In the further slit coating process, the lip 13 is aligned with the coating substrate 61 by a horizontal motion mechanism. During the coating process, the position of the coating substrate 61 is controlled by the horizontal motion mechanism to achieve an automated coating effect. In this process, the distance between the lip 13 and the coating substrate 61 and the moving speed can be controlled by the cooperation of the horizontal motion mechanism and the vertical motion mechanism. The coating speed can be controlled by the cooperation of the horizontal motion mechanism with the coating injection device 40 and the non-polar injection device 50, thereby achieving a variety of coating effects.

[0036] Based on the above embodiments, the actual usage process of the non-polar solution-assisted slit coating die of the present invention is as follows: First, the first mold 10, the second mold 20 and the gasket 30 are assembled and combined with the vertical motion mechanism. The coating substrate 61 and the sealing strip 62 are set on the coating platform 60, and the initial position of the coating platform 60 is such that the sealing strip 62 corresponds to the lip 13.

[0037] After the device is turned on, the lip 13 is in contact with the sealing strip 62. The coating injection device 40 is activated, and an appropriate amount of coating solution is injected into the first injection chamber 11 through the first channel 14. After the coating solution is filled, it will be distributed in the slit of the lip 13 and the gap between the first injection chamber 11 and the second injection chamber 12. Then, the non-polar injection device 50 is activated, and a non-polar solution is injected into the second injection chamber 12 through the second channel 15. The non-polar solution will be distributed in the gasket 30 and the gap between the first injection chamber 11 and the second injection chamber 12, and finally come into contact with the coating solution. During this process, the air in the second injection chamber 12 will be discharged through the exhaust hole 16.

[0038] Then, the coating injection device 40 is locked, and the lip 13 is aligned with the coating substrate 61 by the horizontal movement mechanism. The non-polar injection device 50 is controlled to apply pressure so that the coating solution is squeezed out along the lip 13. After a predetermined amount of coating solution is squeezed out, the coating injection device 40 is unlocked, and new coating solution is added to the first injection chamber 11. At the same time, the non-polar injection device 50 is pumped to return some of the non-polar solution to the non-polar injection device 50. At this point, the non-polar injection device 50 is switched to pressurization again to realize the next coating cycle.

[0039] During the coating process described above, the distance and speed between the lip 13 and the coating substrate 61 are controlled by the cooperation of horizontal and vertical motion mechanisms, according to the desired coating effect. Simultaneously, the horizontal motion mechanism works in conjunction with the coating injection device 40 and the non-polar injection device 50 to accurately control the injection volume, injection timing, and suction timing of the coating solution and non-polar solution, thus achieving an automated coating process. Furthermore, during the coating process, the non-polar solution isolates the coating solution and the gasket 30, preventing corrosion from contact between the coating solution and the gasket 30, ensuring the stability and accuracy of the coating.

[0040] Based on the above embodiments, the present invention also provides a slit coating method, such as... Figure 7 As shown, the slot coating method includes: S100: After injecting the coating solution into the first injection chamber and injecting the non-polar solution into the second injection chamber, push the non-polar solution in the second injection chamber into the first injection chamber so that the coating solution in the first injection chamber flows out from the lip and performs the first coating. S200. The coating solution is injected into the first injection cavity so that the non-polar solution in the first injection cavity returns to the second injection cavity, and then the non-polar solution in the second injection cavity is pushed into the first injection cavity so that the coating solution in the first injection cavity flows out from the lip for the next coating.

[0041] In this embodiment, step S100 is the initial injection of coating solution and non-polar solution. During this process, after the coating solution is injected into the first injection chamber and the non-polar solution is injected into the second injection chamber, a non-polar solution isolation pad is formed inside the coating die head, ensuring uniform contact with the coating solution. When the non-polar solution in the second injection chamber is pushed into the first injection chamber, the coating solution in the first injection chamber flows out from the lip due to hydraulic pressure, thus completing the first coating process. Step S200 is the cyclic coating process after the first coating. During this process, when the coating solution is injected into the first injection chamber, the non-polar solution in the first injection chamber is controlled to retreat into the second injection chamber. At this time, the coating die head is replenished with coating solution. Then, the non-polar solution in the second injection chamber is pushed into the first injection chamber, and the replenished coating solution is squeezed out along the lip. By cyclically operating step S200, continuous slit coating can be achieved.

[0042] Furthermore, the steps of injecting the coating solution into the first injection chamber and injecting the non-polar solution into the second injection chamber further include: S110. Press the lip and the sealing strip together to isolate the air in the gap of the lip; S120. After injecting a coating solution into the first injection cavity, a non-polar solution is injected into the second injection cavity; wherein, when the coating solution is injected into the first injection cavity, the coating solution fills the first injection cavity and the gap at the lip; when the non-polar solution is injected into the second injection cavity, the non-polar solution fills the second injection cavity and the gap between the first injection cavity and the second injection cavity.

[0043] In this embodiment, pressing the lip and sealing strip together ensures that air in the lip gap is effectively isolated, providing a basis for the stable injection of the subsequent coating solution and non-polar solution, and preventing air from affecting the coating quality. While keeping the lip and sealing strip pressed together, when the coating solution is injected into the first injection cavity, the coating solution fully fills the first injection cavity and the gap at the lip. Then, the non-polar solution is injected into the second injection cavity. This non-polar solution fills the second injection cavity and the gap between the first and second injection cavities. On one hand, the non-polar solution provides isolation and protection for the coating solution and the gasket; on the other hand, it allows the non-polar solution to abut against the upper surface of the coating solution. During the subsequent process of pushing the non-polar solution from the second injection cavity into the first injection cavity, it ensures that the coating solution is subjected to uniform hydraulic pressure and flows out evenly from the lip.

[0044] Furthermore, during the above operation, when the coating solution is injected into the first injection cavity, the air in the gap between the first injection cavity and the lip is discharged along the exhaust hole located in the second injection cavity. In this embodiment, since the lip is pressed against the sealing strip, the channel connected to the external air is isolated. Therefore, when the coating solution is injected into the first injection cavity, the air in the coating die moves upward and is discharged along the exhaust hole due to the influence of the gravity of the coating solution, the surface tension of the liquid, and the pressure.

[0045] When a non-polar solution is injected into the second injection chamber, under the influence of gravity, the non-polar solution first forms contact with the upper surface of the coating solution. As the non-polar solution increases, the gas in the corresponding space is discharged along the vent hole until the non-polar solution fills the second injection chamber and forms a coating on the lower surface of the pad. This process ensures that no air remains inside the entire coating die during the injection process, avoiding the formation of air bubbles that affect the coating accuracy.

[0046] Furthermore, the aforementioned process of pushing the non-polar solution from the second injection chamber into the first injection chamber, so that the coating solution in the first injection chamber flows out from the lip opening to perform the first coating, includes: S130. Separate the lip from the sealing strip and move the coating substrate to below the lip; S140, Locking coating injection device; S150: Apply pressure to the non-polar injection device to push the non-polar solution in the second injection chamber into the first injection chamber, so that the coating solution in the first injection chamber flows out from the lip to perform the first coating.

[0047] In this embodiment, since the liquid injection work in the coating die head has been completed in the above steps, the next step is to carry out slit coating. Therefore, the lip and the sealing strip are separated to open the slit at the lip, and the coating substrate is moved to the bottom of the lip to determine the initial coating position and ensure that the coating solution can be accurately coated on the predetermined position of the coating substrate.

[0048] Furthermore, locking the coating injection device is to prevent the coating solution from accidentally flowing out during the process of pushing the non-polar solution into the first injection chamber, causing the coating solution to be sandwiched or mixed with the non-polar solution, thus affecting the coating accuracy and quality. During the process of applying pressure to the non-polar injection device, the non-polar solution in the second injection chamber enters the first injection chamber. At this time, the non-polar solution exerts pressure on the coating solution in the first injection chamber, causing the coating solution to flow out from the lip and be evenly coated on the coating substrate, completing the first coating process.

[0049] It should be noted that during the above operation, the non-polar solution does not need to completely fill the first injection chamber. Partial entry or non-entry does not affect the coating of the solution. In fact, those skilled in the art should control the amount of non-polar solution pushed to prevent the coating solution in the first injection chamber from layering or mixing with the non-polar solution during replenishment. In subsequent operation steps, when the first injection chamber is replenished with coating solution, because the coating solution and the non-polar solution are incompatible, the non-polar solution can be completely pushed back into the second injection chamber and the non-polar injection device under hydraulic pressure.

[0050] In another possible embodiment of the present invention, the above-described injection of the coating solution into the first injection cavity to cause the non-polar solution in the first injection cavity to return to the second injection cavity includes: S210. Unlock the coating injection device; S220. Apply a pushing pressure to the coating injection device to inject the coating solution into the first injection chamber, and apply a pumping pressure to the non-polar injection device to cause the non-polar solution in the first injection chamber to return to the second injection chamber.

[0051] In this embodiment, unlocking the coating injection device allows new coating solution to be injected into the first injection chamber to replenish the coating solution consumed during the first coating process. Subsequently, pressure is applied to the coating injection device to inject new coating solution into the first injection chamber. During this process, the pressure in the first injection chamber gradually increases due to the injection of coating solution. To improve the smoothness of coating replenishment and prevent coating solution from flowing out of the lip due to pressure, suction is simultaneously applied to the non-polar injection device. This operation reduces the pressure in the second injection chamber, creating a pressure difference. Under the action of the pressure difference, the non-polar solution originally located in the first injection chamber is pushed back into the second injection chamber, and a portion of the non-polar solution previously pushed out is drawn back into the non-polar injection device.

[0052] This method not only replenishes the coating solution but also ensures that the non-polar solution does not mix with the newly injected coating solution. Furthermore, during this operation, the non-polar solution maintains its isolating effect on the coating solution and the gasket. After completing the above steps, the state inside the coating die head returns to a state similar to the initial state, except that one coating cycle has been completed on the coating substrate. At this point, the non-polar solution from the second injection chamber can be pushed into the first injection chamber again for the next coating cycle. This process can be repeated to achieve continuous slit coating.

[0053] In summary, the present invention provides a non-polar solution-assisted slit coating die and a slit coating method. The non-polar solution-assisted slit coating die includes: a first die body, including a first injection cavity disposed near the lip, the first injection cavity being used to inject a coating solution; and a second injection cavity disposed away from the lip, the second injection cavity being used to inject a non-polar solution, the first injection cavity and the second injection cavity being spaced apart; a second die body, detachably fastened to one side of the first die body; and a gasket, the gasket being sandwiched between the first die body and the second die body and located on the side away from the lip, so that the lip forms a coating slit.

[0054] This invention provides a first injection cavity on the side of the first mold body near the lip, and a second injection cavity spaced apart on the side away from the lip. When the gasket is clamped on the first and second mold bodies, it corresponds to the side away from the lip. During the coating slit process, the non-polar solution in the second injection cavity isolates the coating solution and the gasket. The non-polar solution pushes and replenishes the coating solution through compression and suction, preventing the coating solution from contacting the gasket and protecting the gasket.

[0055] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A non-polar solution-assisted slit coating die, characterized in that, The non-polar solution-assisted slit coating die head includes: The first mold body includes a first injection cavity disposed near the lip, the first injection cavity being used to inject a coating solution; and a second injection cavity disposed away from the lip, the second injection cavity being used to inject a non-polar solution, the first injection cavity and the second injection cavity being disposed at an interval. The second mold body is detachably fastened to one side of the first mold body; A gasket is sandwiched between the first mold body and the second mold body and is located on the side away from the lip opening, so that the lip opening forms a coating gap.

2. The non-polar solution-assisted slit coating die according to claim 1, characterized in that, The gasket includes extensions at both ends, which protrude toward the lip. A limiting groove is formed between the two extensions, corresponding to the position of the second injection cavity. The limiting groove is used to restrict the extrusion direction of the non-polar solution.

3. The non-polar solution-assisted slit coating die according to claim 2, characterized in that, The limiting groove includes two clearance portions corresponding to the two ends of the second injection cavity, and the clearance portions are semi-circular. The second injection cavity is provided with exhaust holes that extend out of the first mold body at both ends, and the two exhaust holes correspond to the positions of the two relief portions respectively.

4. The non-polar solution-assisted slit coating die according to claim 1, characterized in that, The first injection cavity includes a first channel extending through the upper end of the first mold body, and the first channel is tightly connected to the coating injection device; The second injection cavity includes a second channel extending from the upper end of the first mold body, and the second channel is tightly connected to a non-polar injection device.

5. The non-polar solution-assisted slit coating die according to claim 1, characterized in that, The non-polar solution-assisted slit coating die is driven by a vertical motion mechanism; A coating platform is provided on the lower side of the non-polar solution-assisted slit coating die head. The coating platform is driven by a horizontal motion mechanism. A coating substrate and a sealing strip located on one side of the coating substrate are provided on the coating platform. The shape of the sealing strip is adapted to the shape of the lip.

6. A slit coating method, applied to the non-polar solution-assisted slit coating die of any one of claims 1-5, characterized in that, The slot coating method includes: After injecting a coating solution into the first injection chamber and a non-polar solution into the second injection chamber, the non-polar solution in the second injection chamber is pushed into the first injection chamber so that the coating solution in the first injection chamber flows out from the lip opening to perform the first coating. The coating solution is injected into the first injection cavity so that the non-polar solution in the first injection cavity returns to the second injection cavity. Then, the non-polar solution in the second injection cavity is pushed into the first injection cavity so that the coating solution in the first injection cavity flows out from the lip for the next coating.

7. The slit coating method according to claim 6, characterized in that, The step of injecting the coating solution into the first injection chamber and injecting the non-polar solution into the second injection chamber includes: Press the lip opening and the sealing strip together to isolate the air in the gap of the lip opening; After injecting a coating solution into the first injection cavity, a non-polar solution is then injected into the second injection cavity; wherein, when the coating solution is injected into the first injection cavity, the coating solution fills the first injection cavity and the gap at the lip; when the non-polar solution is injected into the second injection cavity, the non-polar solution fills the second injection cavity and the gap between the first injection cavity and the second injection cavity.

8. The slit coating method according to claim 7, characterized in that, When the coating solution is injected into the first injection chamber, the air in the gap between the first injection chamber and the lip is discharged through the vent hole located in the second injection chamber.

9. The slit coating method according to claim 7, characterized in that, The step of pushing the nonpolar solution from the second injection chamber into the first injection chamber, so that the coating solution from the first injection chamber flows out from the lip opening to perform the first coating, includes: Separate the lip from the sealing strip and move the coated substrate to below the lip; Locking coating injection device; Applying pressure to the nonpolar injection device pushes the nonpolar solution in the second injection chamber into the first injection chamber, so that the coating solution in the first injection chamber flows out from the lip to perform the first coating.

10. The slit coating method according to claim 8, characterized in that, The step of injecting the coating solution into the first injection cavity to cause the non-polar solution in the first injection cavity to return to the second injection cavity includes: Unlock the coating injection device; A pushing pressure is applied to the coating injection device to inject the coating solution into the first injection chamber, and a pumping pressure is applied to the non-polar injection device to cause the non-polar solution in the first injection chamber to return to the second injection chamber.

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