Preparation process of high-temperature-resistant laser-printable film

Abstract

The invention relates to a preparation process of a high-temperature-resistant laser-printable thin film applied to the related technical field of thin film forming, in the coating forming process of a laser sensitive layer, a variable-diameter liquid drainage slit is introduced, the local trend of the liquid drainage slit can be changed through a variable-diameter unit, coating liquid is subjected to channel changing before coating, and during channel changing, the laser sensitive layer is subjected to laser printing; compared with the prior art, the air bubbles in the coating liquid can be extruded and sheared at the small neck position, so that the air bubbles are discharged in an accelerated manner, meanwhile, the channel changing amplitude is controllable, the channel changing amplitude can be controlled to be increased, and the liquid discharging slit is necked synchronously during channel changing, so that the air bubbles in the coating liquid are extruded and sheared at the small neck position, and the air bubbles are discharged actively from passively. And the bubbles are passively discharged, so that the bubble removal effect and removal efficiency can be greatly improved, and the influence of the bubbles on the quality of a formed final film product is effectively reduced.

Description

Technical Field

[0001] The present invention relates to a film preparation process, in particular to a high-temperature resistant laser-printable film preparation process applied to the technical field related to film forming. Background Art

[0002] The main technical challenge in laser-printable films currently lies in the design of the laser-sensitive layer. Conventional laser-printable films (such as PET substrates) have poor temperature resistance (<150°C), while high-temperature-resistant films (such as PI films) typically require marking via inkjet or etching, which can be complex and environmentally polluting. This makes it relatively difficult to combine high-temperature resistance with laser responsiveness.

[0003] To solve the above problems, a nanoparticle-resin synergistic coating liquid system is generally used to simultaneously achieve high temperature resistance and laser response characteristics in a single coating. Since slit coating is a contactless coating method and the wet film thickness accuracy can be controlled within ±1% during coating, the coating liquid is generally applied through slit coating. However, slit coating has the following problems: bubbles are not completely eliminated during the early production process of the coating liquid, or air is introduced during the feeding process, resulting in a certain amount of bubbles in the coating liquid. During coating, pores are easily formed on the wet film, affecting the overall quality of the formed film.

[0004] The slit coating die disclosed in the Chinese patent specification with publication number CN114100958A and the slit coating device disclosed in the Chinese patent specification with publication number CN111434390B both adopt a simple exhaust channel design to achieve pre-elimination of bubbles. However, this method of bubble elimination is relatively passive and less proactive, resulting in poor removal effect. Some smaller bubbles are difficult to remove, and the impact on film thickness and uniformity still exists. Summary of the Invention

[0005] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is that certain bubbles exist in the coating liquid used to form the laser-sensitive coating, and the method for eliminating the bubbles in the prior art is relatively ineffective.

[0006] To solve the above problems, the present invention provides a process for preparing a high-temperature resistant laser-printable film, comprising the following steps: S1. Substrate pretreatment: Select a polyimide film with a thickness of 50-125 μm, perform solvent cleaning and oxygen plasma activation in sequence, and maintain the plasma activation time at 30-60 seconds; S2. Preparation of laser-sensitive coating: Disperse ZrO2 or TiO2 nanoparticles with a particle size of less than 100 nm in methylphenyl silicone resin, and add a mixed solvent to prepare a coating solution with a solid content of 25-35%; S3, coating and curing: A slit coating device is used to form a coating with a wet film thickness of 40-60μm on the substrate. Visual inspection is performed and multiple lane changes and necking operations are adapted to maintain the wet film free of pores and stripe marks. The wet film is then step-dried and cured to obtain a high-temperature resistant laser-printable film. S31. A visual inspection unit is provided on the side of the slit coating equipment close to the drying side. A diameter-changing unit is provided inside the slit coating equipment. After coating, the wet film is visually inspected to promptly detect defects such as air holes and streaks. When the above defects are detected, the diameter-changing unit is used to continuously change the channel and shrink the drainage slit to eliminate bubbles and reduce the quality of the subsequently obtained film. S4. Laser printing is performed on the obtained film: a 1064 nm fiber laser is used to control the energy density to 1-5 J / cm² for marking and printing; The slit coating equipment includes a coating die and a pressure system for controlling coating. A visual inspection unit is provided on the side of the coating die near the drying side. The visual inspection unit includes a high-definition camera and an image analysis unit. A vertical drainage slit is opened in the middle of the coating die, and a liquid collecting hemispherical cavity is opened on the inner wall of the middle of the drainage slit. The curved inner wall of the liquid collecting hemispherical cavity is fixedly connected to a liquid supply channel. The liquid supply channel is fixedly passed through the coating die, and the diameter reducing unit is arranged inside the turning point of the coating die.

[0007] In the above-mentioned high-temperature resistant laser-printable film preparation process, a variable-diameter liquid discharge slit is introduced during the coating process, which can perform channel changing and necking operations, so that the coating liquid can be squeezed by channel changing and necking before discharge, thereby assisting the discharge of bubbles. Compared with the existing technology, the passive discharge of bubbles can greatly improve the bubble removal effect and removal efficiency, and effectively reduce the impact of bubbles on the quality of the final film product.

[0008] As a further improvement of the present application, the mixed solvent in step S2 is a solvent prepared according to a volume ratio of xylene:n-butanol=3:1.

[0009] As a further improvement of the present application, the step drying and curing operation in step S3 is specifically as follows: First, dry it at 80°C for 30 minutes, then dry it at 150°C for 1 hour, and finally dry it at 250°C for 2 hours.

[0010] As a further improvement of the present application, the variable diameter unit includes an active lane-changing plate, a passive lane-changing plate, a plurality of electric push rods corresponding to the active lane-changing plate, and a capacity-changing component corresponding to the passive lane-changing plate, which are respectively arranged on the left and right inner walls of the drainage slit. The electric push rods and the capacity-changing component are both located inside the turning point of the coating die head, and both correspond to the middle part of the active lane-changing plate and the passive lane-changing plate. An electromagnetic plate is also fixedly embedded in the coating die head. The electromagnetic plate is on the same side as the trapezoidal groove, and when the electromagnetic plate is energized, it generates a magnetic attraction on the middle part of the passive lane-changing plate.

[0011] As a further improvement of the present application, the variable capacity component includes a trapezoidal groove, a liquid guide groove and a liquid containing cavity excavated in the coating die head. The liquid guide groove connects the trapezoidal groove and the liquid containing cavity, and the liquid containing cavity is higher than the trapezoidal groove. The lower end portion of the liquid guide groove is a triangular open design, and the connection between the liquid guide groove and the trapezoidal groove is close to the top of the trapezoidal groove. The trapezoidal groove is filled with filling liquid, and the liquid level of the filling liquid is not higher than the triangular top of the liquid guide groove mouth.

[0012] As a further improvement of the present application, the active lane change plate includes two oblique change layers and a translation layer fixedly connected between the two oblique change layers. The translation layer is opposite to the middle of the trapezoidal groove. Multiple electric push rods are fixedly connected to the translation layer. The ends of the two oblique change layers away from each other are fixedly connected to the inner wall of the drainage slit. The oblique change layer is a corrosion-resistant elastic structure, and the translation layer is a hard structure.

[0013] As a further improvement of the present application, the passive lane change plate is an elastic structure with ferromagnetic material embedded inside, and the upper and lower ends of the passive lane change plate are fixedly connected to the inner wall of the drainage slit.

[0014] As another improvement of the present application, the passive lane change plate includes an elastic covering layer fixedly sealed at the mouth of the trapezoidal groove and a porous dynamic layer located outside the mouth of the trapezoidal groove. A laser emitter is also provided at the liquid cavity, and the axis of the laser emitter is not lower than the first three-point point of the straight line of the liquid cavity from top to bottom.

[0015] As another improved supplement to the present application, the porous dynamic layer includes a pre-filter layer and a dynamic positioning end and a fixed positioning end respectively fixedly connected to the upper and lower ends of the pre-filter layer. The fixed positioning end is fixedly connected to the lower end portion of the trapezoidal groove, and the dynamic positioning end is magnetically fixed to the upper end portion of the trapezoidal groove. Electromagnetic blocks are fixedly embedded in the left and right inner walls of the drainage slit. Both electromagnetic blocks correspond to the upper end of the passive lane change plate. When the two electromagnetic blocks are energized, they both generate magnetic attraction on the dynamic positioning end, and the pre-filter layer is an elastic porous structure.

[0016] In summary, during the coating process, the setting of a variable diameter drainage slit is introduced, and the local direction of the drainage slit can be changed through the variable diameter unit, so that the coating liquid changes lanes before coating. When changing lanes, the bubbles will be subjected to certain collision fluctuations, thereby accelerating their discharge. At the same time, the amplitude of the lane change is controllable, and the amplitude of the lane change can be controlled to increase, so that the drainage slit can synchronously achieve necking when changing lanes, thereby squeezing and shearing the bubbles in the coating liquid at the small neck, and changing the discharge of bubbles from passive to active. Compared with the existing technology, the passive discharge of bubbles can greatly improve the bubble removal effect and efficiency, and effectively reduce the influence of bubbles on the quality of the final film product. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of the first embodiment of this application; Figure 2 This is a cross-sectional view of a coating die head according to a first embodiment of the present application; Figure 3 A cross-sectional view of the lower end portion of the coating die head according to the first embodiment of the present application; Figure 4 This is a schematic cross-sectional view of the lower end portion of the coating die head when the drainage slit is redirected according to the first embodiment of the present application; Figure 5 This is a schematic diagram of the diversion portion of the drainage slit according to the first embodiment of the present application; Figure 6 This is a schematic diagram of the first embodiment of the present application when the diversion portion of the drainage slit is necked; Figure 7 This is a front view of the active lane change blade according to the first embodiment of the present application; Figure 8 This is a schematic diagram of a coating die head according to a second embodiment of the present application; Figure 9 This is a schematic diagram of the second embodiment of the present application in which the drainage slit diversion portion forms a filter layer; Figure 10 This is a schematic diagram of a passive lane change blade according to a second embodiment of the present application; Figure 11 This is a partial transverse schematic diagram of the liquid containing chamber according to the second embodiment of the present application; Figure 12 This is a cross-sectional schematic diagram of the assembleable and disassembled coating die head in the second embodiment of the present application.

[0018] Description of the numbers in the figure: 1 coating die head, 101 liquid discharge slit, 102 liquid collecting hemispherical cavity, 103 liquid supply channel, 2 electric push rods, 3 active lane change blades, 31 oblique change layer, 32 translation layer, 4 passive lane change blades, 41 elastic covering layer, 42 porous dynamic layer, 421 pre-filter layer, 422 dynamic positioning end, 423 fixed positioning end, 51 trapezoidal groove, 52 liquid containing cavity, 53 liquid guide groove, 6 laser emitters. DETAILED DESCRIPTION

[0019] Two implementation modes of the present application are described in detail below with reference to the accompanying drawings.

[0020] The first implementation method: Figure 1 A process for preparing a high-temperature resistant laser-printable film is shown, comprising the following steps: S1. Substrate pretreatment: Select a polyimide film with a thickness of 50-125 μm, perform solvent cleaning and oxygen plasma activation in sequence, and maintain the plasma activation time at 30-60 seconds; S2. Preparation of laser-sensitive coating: Dispersing ZrO2 or TiO2 nanoparticles (20-30 wt%) with a particle size of less than 100 nm in methylphenyl silicone resin, and adding a mixed solvent to prepare a coating solution with a solid content of 25-35%, wherein the mixed solvent is a solvent prepared in a volume ratio of xylene:n-butanol = 3:1; S3, coating and curing: A slit coating device is used to form a coating with a wet film thickness of 40-60μm on the substrate. Visual inspection is performed and multiple lane changes and necking operations are adapted to maintain the wet film free of pores and stripe marks. The wet film is then step-dried and cured to obtain a high-temperature resistant laser-printable film. S31. The slit coating equipment is provided with a visual inspection unit near the drying side, and a diameter-changing unit is provided inside the slit coating equipment. The wet film is visually inspected after coating to detect defects such as pores and stripes in time. When the above defects are detected, the drainage slit 101 is continuously changed and necked by the diameter-changing unit to eliminate bubbles and reduce the quality of the film obtained subsequently. During the coating process, the setting of the variable diameter drainage slit 101 is introduced, which can change the channel and neck, so that the coating liquid can be squeezed by the channel change and necking before being discharged, thereby assisting the discharge of bubbles. Compared with the existing technology, the passive discharge of bubbles can greatly improve the bubble removal effect and efficiency, and effectively reduce the influence of bubbles on the quality of the final film product.

[0021] The specific operation of step drying and curing is as follows: First, dry it at 80°C for 30 minutes, then dry it at 150°C for 1 hour, and finally dry it at 250°C for 2 hours.

[0022] S4. Laser printing is performed on the obtained film: a 1064 nm fiber laser is used to control the energy density to 1-5 J / cm² for marking and printing; like Figure 2 The slit coating equipment includes a coating die 1 and a pressure system for controlling coating. A visual inspection unit is provided on the side of the coating die 1 close to the drying side. The visual inspection unit includes a high-definition camera and an image analysis unit. A vertical drainage slit 101 is opened in the middle of the coating die 1. A liquid collecting hemispherical cavity 102 is opened on the inner wall of the middle of the drainage slit 101. The curved inner wall of the liquid collecting hemispherical cavity 102 is fixedly connected with a liquid supply channel 103. The liquid supply channel 103 is fixedly passed through the coating die 1. The diameter reducing unit is arranged inside the turning point of the coating die 1.

[0023] It is worth noting that the liquid level of the coating liquid is higher than the lower end of the liquid supply channel 103, and the upper end of the drainage slit 101 is connected to a one-way valve, so that the gas can be discharged from the inside to the outside, and the outside air cannot enter the drainage slit 101. During the operation of changing lanes and necking, the air in the squeezed and broken bubbles will gradually float up and be discharged outward along the drainage slit 101.

[0024] like Figure 3 The variable diameter unit includes an active lane-changing piece 3 and a passive lane-changing piece 4, which are respectively arranged on the left and right inner walls of the drainage slit 101, a plurality of electric push rods 2 corresponding to the active lane-changing piece 3, and a capacity-changing component corresponding to the passive lane-changing piece 4. The electric push rods 2 and the capacity-changing component are both located inside the turning point of the coating die 1, and both correspond to the middle parts of the active lane-changing piece 3 and the passive lane-changing piece 4. An electromagnetic piece is also fixedly embedded in the coating die 1. The electromagnetic piece is on the same side as the trapezoidal groove 51, and when the electromagnetic piece is energized, it generates a magnetic attraction on the middle part of the passive lane-changing piece 4. The passive lane-changing piece 4 is an elastic structure with ferromagnetic material embedded inside, and the upper and lower ends of the passive lane-changing piece 4 are fixedly connected to the inner wall of the drainage slit 101.

[0025] like Figure 4 The variable capacity component includes a trapezoidal groove 51, a liquid guide groove 53 and a liquid holding cavity 52 cut in the coating die head 1. The liquid guide groove 53 connects the trapezoidal groove 51 and the liquid holding cavity 52, and the liquid holding cavity 52 is higher than the trapezoidal groove 51. The lower end of the liquid guide groove 53 is a triangular open design, and the connection between the liquid guide groove 53 and the trapezoidal groove 51 is close to the top of the trapezoidal groove 51. The trapezoidal groove 51 is filled with a filling liquid. The filling liquid is a liquid with poor fluidity and high viscosity, so that the liquid level in the trapezoidal groove 51 is not easy to be excessively adjusted under normal circumstances, so that the passive lane change plate 4 can be relatively stable under normal circumstances, and then the drainage slit 101 is relatively stable, and the liquid level of the filling liquid is not higher than the triangular top of the mouth of the liquid guide groove 53, as shown in FIG. Figure 5-6When the drainage slit 101 needs to change lanes, the electromagnetic plate can be energized to adsorb the passive lane-changing plate 4, causing the passive lane-changing plate 4 to move toward the trapezoidal groove 51, thereby providing a certain space for the movement of the active lane-changing plate 3, so that the drainage slit 101 has enough space to change lanes; at the same time, under the pressure of the passive lane-changing plate 4, the filling liquid in the trapezoidal groove 51 can gradually move along the liquid guide groove 53 toward the liquid containing cavity 52 to avoid, so that the movement of the passive lane-changing plate 4 is not easily obstructed. When not changing lanes, the filling liquid in the trapezoidal groove 51 can provide a certain supporting force, so that the passive lane-changing plate 4 is not easily deformed, and the stability of the drainage slit 101 can be maintained.

[0026] like Figure 7 The active lane change blade 3 includes two oblique change layers 31 and a translation layer 32 fixedly connected between the two oblique change layers 31. The translation layer 32 is opposite to the middle of the trapezoidal groove 51. Multiple electric push rods 2 are fixedly connected to the translation layer 32. The ends of the two oblique change layers 31 that are away from each other are fixedly connected to the inner wall of the drainage slit 101. The oblique change layer 31 is a corrosion-resistant elastic structure, and the translation layer 32 is a hard structure. When the electric push rod 2 is extended, it has a stable fulcrum, so that the active lane change blade 3 can show a trapezoidal change as a whole, thereby adapting to the shape of the trapezoidal groove 51, and making the drainage slit 101 at the lane change better.

[0027] like Figure 3 When the coating die head 1 is not working, the active lane-changing piece 3 and the passive lane-changing piece 4 are in their original vertical state. When coating starts, the electric push rod 2 can be extended to push the active lane-changing piece 3, and the electromagnetic piece can be turned on simultaneously to absorb the passive lane-changing piece 4 to retract, thereby achieving lane change, thereby extending the falling path of the coating liquid, and requiring multiple bends and diversions during the falling process, thereby increasing the squeezing and shearing force on the bubbles and accelerating the overflow of the bubbles. When the visual inspection unit detects that there are still air holes in step S3, the electric push rod 2 can be further extended to reduce the gap of the drainage slit 101 at the diversion point, thereby achieving necking, so as to further eliminate When the visual inspection unit detects that the wet film formed in step S3 has a striped pattern, it is judged that the drainage slit 101 may have excessive necking, which has affected the falling of the coating liquid to a certain extent. At this time, the electric push rod 2 can be controlled to shorten to reduce the necking amplitude. At this time, the gap between the active lane change blade 3 and the passive lane change blade 4 is increased, so that the falling resistance of the coating liquid is reduced until the wet film is restored. Through the cooperation of the visual inspection unit, the operations of diversion and necking can be controlled in real time, thereby maintaining the coated wet film without pores and stripe defects. Compared with the existing technology, the quality of the final finished film is effectively guaranteed.

[0028] In summary, during the coating process, the setting of the variable diameter drainage slit 101 is introduced, and the local direction of the drainage slit 101 can be changed through the variable diameter unit, so that the coating liquid changes lanes before coating. When changing lanes, the bubbles will be subjected to certain collision fluctuations, thereby accelerating their discharge. At the same time, the amplitude of the lane change is controllable, and the amplitude of the lane change can be controlled to increase, so that the drainage slit 101 can synchronously achieve necking when changing lanes, thereby squeezing and shearing the bubbles in the coating liquid at the small neck, so that the discharge of the bubbles changes from passive to active. Compared with the existing technology, the passive discharge of bubbles can greatly improve the bubble removal effect and efficiency, and effectively reduce the influence of bubbles on the quality of the final film product.

[0029] The second implementation method: This embodiment further improves the passive lane change blade 4 on the basis of the first embodiment, and the rest of the parts remain the same as the first embodiment.

[0030] Figure 8 As shown, the passive lane change plate 4 includes an elastic covering layer 41 fixedly sealed at the mouth of the trapezoidal groove 51 and a porous dynamic layer 42 located outside the mouth of the trapezoidal groove 51, as shown in FIG. Figure 11 , a laser emitter 6 is also provided at the liquid chamber 52, and the axis of the laser emitter 6 is not lower than the first three points of the straight line from the top to the bottom of the liquid chamber 52, such as Figure 10 The porous dynamic layer 42 includes a pre-filter layer 421 and a dynamic positioning end 422 and a fixed positioning end 423 fixedly connected to the upper and lower ends of the pre-filter layer 421 respectively. The fixed positioning end 423 is fixedly connected to the lower end portion of the trapezoidal groove 51, and the dynamic positioning end 422 is magnetically fixed to the upper end portion of the trapezoidal groove 51. Electromagnetic blocks are fixedly embedded in the left and right inner walls of the drainage slit 101. Both electromagnetic blocks correspond to the upper end of the passive lane change plate 4. When the two electromagnetic blocks are energized, they both generate magnetic attraction on the dynamic positioning end 422. The pre-filter layer 421 is an elastic porous structure and is made of high temperature and corrosion resistant materials.

[0031] like Figure 9At regular intervals, the two electromagnetic blocks on the same side of the electric push rod 2 can be controlled to be energized, and then the electromagnetic block on the same side of the trapezoidal groove 51 can be controlled to be de-energized, so that the upper end of the porous dynamic layer 42 quickly moves toward the other inner wall of the drainage slit 101 and is fixed and adsorbed. At this time, the passive lane-changing piece 4 is in an inclined state and spans the drainage slit 101, which can shear and intercept the falling coating liquid to form a temporary filter layer. When there are many particulate impurities in it, the passive lane-changing piece 4 will gradually be blocked. At this time, the pressure there gradually increases, causing the filling liquid to be pressurized and the liquid level to move up. When the liquid level reaches the laser emitter 6, the laser emitter 6 can quickly obtain the signal, and then judge that there are too many impurities in the coating liquid, which is convenient for the staff to adjust the coating liquid in time, effectively avoiding the continuous wet film coating of substandard coating liquid, resulting in batches of substandard film products, thereby effectively reducing resource waste.

[0032] like Figure 12 It is worth noting that in order to facilitate the cleaning of the particle impurities intercepted by the passive lane change piece 4, the coating die head of the corresponding passive lane change piece and the variable capacity component can be set to be assembled and detachable and fixed by bolts.

[0033] The detection time of each passive lane change piece 4 is set according to actual needs. When the detection time is passed and the laser emitter 6 is not triggered, it can be judged that the coating liquid does not contain small particles, or contains very few small particles, that is, the particulate impurities do not exceed the standard. At this time, the two electromagnetic blocks can be controlled to cooperate again to realize the restoration of the upper end of the passive lane change piece 4 to above the mouth of the trapezoidal groove 51. At this time, the diversion, necking and bubble removal operations of the first embodiment can be continued.

[0034] Since the coating liquid is prone to oxidation and condensation of small particles, the long-term aggregation of small particles can easily clog the mouth of the coating head, resulting in an overall striped defect, affecting the quality of the finished product. In addition, when the drainage slit 101 is not blocked in time in the early stage, the excessive content of small particles in the coating liquid will also affect the quality of the finished product, easily leading to substandard batches of finished film and a waste of resources. This embodiment is mainly set up based on this problem, which facilitates the timely detection of the problem of small particle condensation in the coating liquid and effectively avoids the subsequent problem of the drainage slit 101 being blocked.

[0035] In view of current actual needs, the protection scope of the above-mentioned implementation mode adopted in this application is not limited to this. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the protection scope of the present invention.

Claims

1. A process for preparing a high-temperature resistant laser-printable film, characterized in that: The following steps are involved: S1. Substrate pretreatment: Select a polyimide film with a thickness of 50-125 μm, perform solvent cleaning and oxygen plasma activation in sequence, and maintain the plasma activation time at 30-60 seconds; S2. Preparation of laser-sensitive coating: Disperse ZrO2 or TiO2 nanoparticles (20-30 wt%) with a particle size of less than 100 nm in methylphenyl silicone resin, and add a mixed solvent to prepare a coating solution with a solid content of 25-35%; S3, coating and curing: A slit coating device is used to form a coating with a wet film thickness of 40-60μm on the substrate. Visual inspection is performed and multiple lane changes and necking operations are adapted to maintain the wet film free of pores and stripe marks. The wet film is then step-dried and cured to obtain a high-temperature resistant laser-printable film. S31. A visual inspection unit is provided on the side of the slit coating device close to the drying side. A diameter-changing unit is provided inside the slit coating device. After coating, the wet film is visually inspected to promptly detect defects such as air holes and stripes. When the above defects are detected, the drainage slit (101) is continuously operated by changing the channel and shrinking the neck through the diameter-changing unit to eliminate bubbles and reduce the quality of the film obtained subsequently. S4. Laser printing is performed on the obtained film: a 1064 nm fiber laser is used to control the energy density to 1-5 J / cm² for marking and printing; The slit coating device comprises a coating die (1) and a pressure system for controlling coating, wherein a visual inspection unit is provided on a side of the coating die (1) close to the drying side, wherein the visual inspection unit comprises a high-definition camera and an image analysis unit, wherein a vertical liquid discharge slit (101) is formed in the middle of the coating die (1), a liquid collecting hemispherical cavity (102) is formed on the inner wall of the middle of the liquid discharge slit (101), a liquid supply channel (103) is fixedly connected to the curved inner wall of the liquid collecting hemispherical cavity (102), and the liquid supply channel (103) is fixedly passed through the coating die (1), and the diameter reducing unit is provided inside the turning point of the coating die (1).

2. The process for preparing a high-temperature resistant laser-printable film according to claim 1, characterized in that: The mixed solvent in step S2 is a solvent prepared according to a volume ratio of xylene:n-butanol=3:

1.

3. The process for preparing a high-temperature resistant laser-printable film according to claim 1, wherein: The step drying and curing operation in step S3 is specifically as follows: First, dry it at 80°C for 30 minutes, then dry it at 150°C for 1 hour, and finally dry it at 250°C for 2 hours.

4. The process for preparing a high-temperature resistant laser-printable film according to claim 1, wherein: The variable diameter unit comprises an active lane-changing plate (3), a passive lane-changing plate (4), a plurality of electric push rods (2) corresponding to the active lane-changing plate (3), and a variable capacity component corresponding to the passive lane-changing plate (4), which are respectively arranged on the left and right inner walls of the liquid discharge slit (101). The electric push rods (2) and the variable capacity component are both located inside the turning point of the coating die head (1), and both correspond to the middle parts of the active lane-changing plate (3) and the passive lane-changing plate (4). An electromagnetic plate is also fixedly embedded in the coating die head (1). The electromagnetic plate is on the same side as the trapezoidal groove (51), and generates a magnetic attraction force on the middle part of the passive lane-changing plate (4) when the electromagnetic plate is energized.

5. The process for preparing a high-temperature resistant laser-printable film according to claim 4, characterized in that: The variable capacity component comprises a trapezoidal groove (51), a liquid guide groove (53) and a liquid containing cavity (52) cut into the coating die head (1); the liquid guide groove (53) connects the trapezoidal groove (51) and the liquid containing cavity (52), and the liquid containing cavity (52) is higher than the trapezoidal groove (51); the lower end of the liquid guide groove (53) is designed as a triangular opening, and the connection between the liquid guide groove (53) and the trapezoidal groove (51) is close to the top of the trapezoidal groove (51); the trapezoidal groove (51) is filled with a filling liquid, and the liquid level of the filling liquid is not higher than the triangular top of the mouth of the liquid guide groove (53).

6. The process for preparing a high-temperature resistant laser-printable film according to claim 5, characterized in that: The active lane change plate (3) includes two oblique change layers (31) and a translation layer (32) fixedly connected between the two oblique change layers (31), the translation layer (32) is directly opposite the middle of the trapezoidal groove (51), the plurality of electric push rods (2) are fixedly connected to the translation layer (32), the ends of the two oblique change layers (31) that are away from each other are fixedly connected to the inner wall of the drainage slit (101), the oblique change layer (31) is a corrosion-resistant elastic structure, and the translation layer (32) is a hard structure.

7. The process for preparing a high-temperature resistant laser-printable film according to claim 4, wherein: The passive lane changing plate (4) is an elastic structure with ferromagnetic material embedded inside, and both upper and lower ends of the passive lane changing plate (4) are fixedly connected to the inner wall of the drainage slit (101).

8. The process for preparing a high-temperature resistant laser-printable film according to claim 4, characterized in that: The passive lane change plate (4) comprises an elastic covering layer (41) fixedly sealed at the mouth of the trapezoidal groove (51) and a porous dynamic layer (42) located outside the mouth of the trapezoidal groove (51). A laser emitter (6) is also provided at the liquid containing cavity (52), and the axis of the laser emitter (6) is not lower than the first three-point point of the straight line from the top to the bottom of the liquid containing cavity (52).

9. The process for preparing a high-temperature resistant laser-printable film according to claim 8, characterized in that: The porous dynamic layer (42) includes a pre-filter layer (421) and a dynamic positioning end (422) and a fixed positioning end (423) respectively fixedly connected to the upper and lower ends of the pre-filter layer (421), the fixed positioning end (423) being fixedly connected to the lower end portion of the trapezoidal groove (51), and the dynamic positioning end (422) being magnetically fixed to the upper end portion of the trapezoidal groove (51). Electromagnetic blocks are fixedly embedded in the left and right inner walls of the liquid discharge slit (101), and the two electromagnetic blocks correspond to the upper end of the passive lane change plate (4). When the two electromagnetic blocks are energized, they both generate magnetic attraction on the dynamic positioning end (422), and the pre-filter layer (421) is an elastic porous structure.

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