Infrared cutoff filter and spin coating preparation method

Abstract

The present invention discloses an infrared cut-off filter and a spin coating preparation method, the preparation method comprising the following steps: providing a glass substrate, and cleaning and pre-treating the surface of the glass substrate; sequentially coating and curing an infrared cut-off film, an anti-reflection film, an antistatic film and a waterproof and oil-proof film on the glass substrate by a spin coating process, so that a composite film is formed on the glass substrate; performing a multi-stage thermal curing treatment on the composite film on the glass substrate; and coating a protective film on the composite film after cooling. The present invention improves the adsorption force of the film layer during adsorption by fine cleaning of the glass substrate, and at the same time, through the coating and coating process of the composite film, it also solves the problem of unevenness and inappropriate thickness of the composite film during coating and coating, so that when the infrared cut-off filter is in use, the composite film provides good filtering and light transmission effects for the infrared cut-off filter, and prevents the infrared cut-off filter from being affected by the outside world, thereby improving the image quality.

Description

Technical Field

[0001] The invention relates to the field of preparation of infrared cut-off filters, and in particular to an infrared cut-off filter and a spin coating preparation method. Background Art

[0002] An infrared cut-off filter is an optical filter specially designed to block or reduce the transmission of infrared light while allowing visible light to pass. Such filters are widely used in various optical and electronic devices, including digital cameras, camcorders and other optical instruments that need to filter infrared light. Infrared cut-off filters have the advantages of improving image quality and protecting optical components.

[0003] The infrared cut-off filters currently used in smartphone cameras are limited by the existing coating process, resulting in uneven film layers, inappropriate thickness and insufficient adhesion. As a result, during the use of the infrared cut-off filter, the film layer is affected by itself and external environmental factors, which reduces the light transmittance and filtering effect of the infrared cut-off filter, thereby affecting image quality.

[0004] Therefore, an infrared cut-off filter and a spin coating preparation method are proposed to solve the problems of uneven film layer, inappropriate thickness and insufficient adhesion on the infrared cut-off filter. Summary of the invention

[0005] The object of the present invention is to provide an infrared cut-off filter and a spin coating preparation method, so as to solve the problems of uneven film layer, inappropriate thickness and insufficient adhesion on the infrared cut-off filter.

[0006] To achieve this purpose, the present invention adopts the following technical solutions: A spin coating preparation method for an infrared cut-off filter, the preparation method comprising the following steps: Step S100, providing a glass substrate, and cleaning and pre-treating the surface of the glass substrate; Step S200, coating a cured infrared cutoff film, an antireflection film, an antistatic film and a waterproof and oil-proof film on the glass substrate in sequence by a spin coating process to form a composite film on the glass substrate; Step S300, performing a multi-stage thermal curing treatment on the composite film on the glass substrate; Step S400: coating a protective film on the cooled composite film.

[0007] The step S100 specifically includes: Step S110, placing the glass substrate in an ultrasonic cleaning device, and ultrasonically cleaning the surface of the substrate using deionized water and a 2% NaOH solution; Step S120, placing the cleaned glass substrate in a hot air drying device and performing a drying process at a temperature of 70° C. to 80° C.; Step S130, placing the dried glass substrate in a clean room environment, controlling the ambient temperature and humidity to 20°C to 30°C and 40% to 45% humidity, and waiting for cooling to room temperature; Step S140, after cleaning the surface of the glass substrate by a plasma cleaning device, an ultra-thin transition layer is formed on the surface by a vapor deposition method; Step S150: finely polishing the surface of the glass substrate by an optical grinder.

[0008] The step S200 specifically includes: Step S210, pre-treating the coatings of the infrared cut-off film, the anti-reflection film, the antistatic film and the waterproof and oil-proof film by adjusting the viscosity and performing a heating treatment; Step S220, fixing the glass substrate on a rotating table of a spin coating device, and then allowing the rotating device to coat the infrared cutoff film coating on the surface of the glass substrate at a preset rotation speed and time, and curing the coating to obtain an infrared cutoff film; Step S230, allowing the rotating device to coat the anti-reflection film coating on the infrared cut-off film at a preset rotation speed and time, and to cure the anti-reflection film to obtain the anti-reflection film; Step S240, allowing the rotating device to coat the antistatic film coating on the antireflection film at a preset rotation speed and time, and solidify it to obtain an antistatic film; Step S250: allowing the rotating device to coat the waterproof and oil-proof film coating on the antistatic film at a preset rotation speed and time, and to cure the coating to obtain a waterproof and oil-proof film.

[0009] The step S300 specifically includes: Step S310, performing multi-stage curing of low temperature curing, high temperature curing and ultra-high temperature curing on the composite film; Step S320, using low-power plasma treatment equipment to clean and enhance the surface of the cured composite film again; Step S330, cooling the composite film after the plasma treatment to room temperature at a cooling rate of 4°C / min to 5°C / min.

[0010] The step S400 specifically includes: Step S410, fixing the glass substrate on a rotating worktable and rotating it at a preset speed; Step S420, spraying the protective coating on the surface of the composite film along a circular spiral path through a fully automated electrostatic spraying system, and extending outward from the center of the composite film to the edge; Step S430: After the protective coating is sprayed, thermal curing is performed to obtain a protective film.

[0011] In step S220, the infrared cut-off film coating includes coating, Coating and ITO transition film coating; When the infrared cut-off film coating is applied, five layers of 75 nm to 85 nm thick are applied alternately. Coating and coating, and in the 5th layer Coating with Layer 6 An ITO transition film coating with a thickness of 15nm to 25nm is applied between the coating layers; Coating by rotating equipment coating, When coating with ITO transition film, first perform preliminary spin coating and then perform secondary spin coating, wherein the preliminary spin coating speed is 400rpm~500rpm, the spin coating time is 10s~15s, the secondary coating speed is 1900rpm~2000rpm, and the spin coating time is 30s~35s; In step S230, the anti-reflection film coating is Coating, the thickness of the antireflection film coating is 100nm to 110nm; When the anti-reflection film coating is coated by a spin coating device, a preliminary spin coating is performed first and then a secondary spin coating is performed, wherein the preliminary spin coating speed is 400 rpm to 600 rpm, the spin coating time is 10 s to 15 s, the secondary coating speed is 2300 rpm to 2500 rpm, and the spin coating time is 30 s to 40 s; In step S240, the antistatic film coating is an ITO coating, and the thickness of the antistatic film coating is 95nm to 100nm; When the antistatic film coating is coated by a spin coating device, a preliminary spin coating is performed first and then a secondary spin coating is performed, wherein the preliminary spin coating speed is 500rpm-700rpm, the spin coating time is 15s-20s, the secondary coating speed is 2000rpm-2200rpm, and the spin coating time is 30s-35s; In step S250, the waterproof and oil-proof film coating is a PTFE coating, and the thickness of the waterproof and oil-proof film coating is 50nm to 60nm; When the antistatic film coating is coated by a spin coating device, the spin coating speed is 1400 rpm to 1500 rpm, and the spin coating time is 15 s to 20 s.

[0012] In step S220, after the infrared cutoff film coating is applied, a heat curing device is used to cure it to form an infrared cutoff film, wherein the curing temperature of the heat curing device is 110° C. to 120° C. and the curing time is 15 min to 20 min. In step S230, after the anti-reflection film coating is applied, a thermal curing device is used to cure it to form an anti-reflection film, wherein the curing temperature of the thermal curing device is 100° C. to 110° C. and the curing time is 10 min to 15 min. In step S240, after the antistatic film coating is applied, a heat curing device is used to cure it to form an antistatic film, wherein the curing temperature of the heat curing device is 140° C. to 150° C. and the curing time is 20 min to 25 min. In step S250, after the waterproof and oil-proof film coating is applied, it is cured by ultraviolet curing equipment to form a waterproof and oil-proof film, wherein the curing wavelength of the ultraviolet curing equipment during curing is 365nm and the time is 30s to 40s.

[0013] In the step S310, the low temperature curing temperature is 100°C to 110°C, the curing time is 25min to 30min, and the heating rate is 4°C / min to 5°C / min; the high temperature curing temperature is 120°C to 130°C, the curing time is 1h to 1.2h, and the heating rate is 4°C / min to 5°C / min; the ultra-high temperature curing temperature is 140°C to 150°C, the curing time is 10min to 15min, and the heating rate is 4°C / min to 5°C / min; In the step S320, the power of the plasma processing equipment is 40W to 50W, and the processing time is 15s to 20s.

[0014] In the step S410, the rotation speed of the workbench is 10 rpm to 15 rpm; In the step S420, the protective coating comprises modified silicone resin, nano-aluminum oxide particles and isopropyl alcohol, and the thickness of the protective coating is 5 to 10 μm; The nozzle diameter in the fully automated electrostatic spraying system is 0.2-0.3 mm, the spray angle is 65°C-70°C, the spray flow rate is 5-10 mL / min, and the air source pressure is 0.2-0.3 MPa; When the nozzle is spraying in the fully automated electrostatic spraying system, the vertical distance between the nozzle and the composite film is 15 cm to 20 cm, and the spraying speed of the nozzle is 10 cm / s to 15 cm / s; In the step S430, the thermal curing temperature is 110°C to 120°C, the curing time is 30min to 40min, and the curing is performed at a heating rate of 4°C / min to 5°C / min; After the protective coating is thermally cured, air flow circulation is performed in the thermal curing equipment for 4 to 5 minutes.

[0015] An infrared cutoff filter is prepared by the spin coating preparation method of the infrared cutoff filter as described above, the infrared cutoff filter comprises a glass substrate and a composite film, a protective film is arranged on the composite film, wherein the composite film comprises an infrared cutoff film, an anti-reflection film, an antistatic film, and a waterproof and oil-proof film from bottom to top.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. An infrared cutoff filter and a spin coating preparation method improve the adsorption force of the film layer by fine cleaning of the glass substrate, and at the same time solve the problem of unevenness and inappropriate thickness of the composite film during coating and coating through the coating process of the composite film. Therefore, when the infrared cutoff filter is in use, the composite film provides good filtering and light transmission effects for the infrared cutoff filter, prevents the infrared cutoff filter from being affected by the outside world, and improves the image quality.

[0017] 2. An infrared cutoff filter and a spin coating preparation method. The composite film is set to effectively improve the image quality of the infrared cutoff filter when in use. The cooperation of the infrared cutoff film and the anti-reflection film improves the filtering and light transmission effects of the infrared cutoff filter, prevents the color distortion of the imaging sensor, and reduces the loss of reflected light. At the same time, under the action of the antistatic film and the water- and oil-resistant film, the applicability of the infrared cutoff filter in humid and dusty environments is enhanced, ensuring that the optical performance of the infrared cutoff filter is not affected during long-term use.

[0018] 3. An infrared cutoff filter and a spin coating preparation method, through multi-stage thermal curing treatment, the mechanical strength and wear resistance of the composite film are significantly improved, and the cracking and wear of the film layer caused by mechanical stress or external environmental changes are reduced. The multi-stage curing process optimizes the microstructure of the film layer, reduces stress accumulation and light scattering, and improves the overall durability and reliability, making it suitable for various harsh environmental conditions.

[0019] 4. An infrared cutoff filter and a spin coating preparation method, which significantly improves the production efficiency and coating uniformity during protective film spraying through a fully automated electrostatic spraying system and annular spiral path spraying technology. The spraying system uses charged particles to quickly and evenly adhere to the surface of the composite film to form a dense protective layer, so that the protective film can effectively protect the composite film and increase the service life of the composite film. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0022] Figure 1 is a preparation flow chart of the method of the present invention; Figure 2 It is a schematic diagram of the cross-sectional structure of the composite membrane in the present invention.

[0023] Illustrations: 1. Glass substrate; 2. Composite film; 21. Infrared cutoff film; 22. Anti-reflection film; 23. Antistatic film; 24. Waterproof and oil-proof film; 3. Protective film. DETAILED DESCRIPTION

[0024] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0026] Embodiment 1: See also Figure 1In this embodiment, a spin coating preparation method of an infrared cut-off filter comprises the following steps: Step S100, providing a glass substrate, and cleaning and pre-treating the surface of the glass substrate; It should be noted that by cleaning and pre-treating the glass substrate, the light scattering phenomenon caused by the rough surface of the glass substrate can be reduced, the transmittance can be improved, and the adhesion of the composite film to the glass substrate can be improved.

[0027] Furthermore, the step S100 specifically includes: Step S110, placing the glass substrate in an ultrasonic cleaning device, and ultrasonically cleaning the surface of the substrate using deionized water and a 2% NaOH solution; Step S120, placing the cleaned glass substrate in a hot air drying device and performing a drying process at a temperature of 70° C. to 80° C.; Step S130, placing the dried glass substrate in a clean room environment, controlling the ambient temperature and humidity to 20°C to 30°C and 40% to 45% humidity, and waiting for cooling to room temperature; Step S140, after cleaning the surface of the glass substrate by a plasma cleaning device, an ultra-thin transition layer is formed on the surface by a vapor deposition method; Step S150, finely polishing the surface of the glass substrate by an optical grinder; Preferably, in step S120, the temperature of the hot air drying equipment is 80°C, and in step S130, the ambient temperature and humidity are controlled to be 25°C and 40%.

[0028] Step S200, coating a cured infrared cutoff film, an antireflection film, an antistatic film and a waterproof and oil-proof film on the glass substrate in sequence by a spin coating process to form a composite film on the glass substrate; It should be noted that by arranging a composite film composed of an infrared cutoff film, an anti-reflection film, an antistatic film and a waterproof and oil-proof film on a glass substrate, the composite film prepared according to the method can be applied to the glass substrate and put on the market, so that it has multiple functions, improves its comprehensive performance, and the mutual cooperation of different films improves the overall optical performance and surface characteristics.

[0029] Furthermore, the step S200 specifically includes: Step S210, pre-treating the coatings of the infrared cut-off film, the anti-reflection film, the antistatic film and the waterproof and oil-proof film by adjusting the viscosity and performing a heating treatment; Step S220, fixing the glass substrate on a rotating table of a spin coating device, and then allowing the rotating device to coat the infrared cutoff film coating on the surface of the glass substrate at a preset rotation speed and time, and curing the coating to obtain an infrared cutoff film; Step S230, allowing the rotating device to coat the anti-reflection film coating on the infrared cut-off film at a preset rotation speed and time, and to cure the anti-reflection film to obtain the anti-reflection film; Step S240, allowing the rotating device to coat the antistatic film coating on the antireflection film at a preset rotation speed and time, and solidify it to obtain an antistatic film; Step S250, allowing the rotating device to apply the waterproof and oil-proof film coating on the antistatic film according to a preset rotation speed and time, and solidify it to obtain a waterproof and oil-proof film; It should be noted that the infrared cutoff film provides excellent infrared shielding effect and reduces the color distortion of the sensor. It works synergistically with the anti-reflection film to ensure high transmittance. The anti-reflection film can improve the transmittance of visible light and reduce reflected light. It provides a uniform optical basis for the anti-static film. The anti-static film can prevent static electricity accumulation and dust adhesion to ensure long-term clear imaging. It cooperates with the waterproof and oil-proof film to improve outdoor adaptability. The waterproof and oil-proof film provides excellent hydrophobic and oleophobic properties to prevent stains from adhering and enhance the effect of the anti-static film in humid environments. The infrared cutoff film, anti-reflection film, anti-static film and waterproof and oil-proof film work synergistically during the application process to ensure imaging quality while having long-term stable environmental adaptability and high-performance reliability.

[0030] Furthermore, in step S220, the infrared cut-off film coating includes coating, Coating and ITO transition film coating; Specifically, Coating for Nanoparticles mixed dispersion, The viscosity of the nanoparticle mixed dispersion was 20 mPa·s; Coating for Nanoparticles mixed dispersion, The viscosity of the nanoparticle mixed dispersion was 20 mPa·s; When the infrared cut-off film coating is applied, five layers of 75 nm to 85 nm thick are applied alternately. Coating and coating, and in the 5th layer Coating with Layer 6 An ITO transition film coating with a thickness of 15nm to 25nm is applied between the coating layers; Preferably, Coating and The coating thickness is 80nm, and the ITO transition film coating thickness is 20nm; Coating by rotating equipment coating, When coating with ITO transition film, first perform preliminary spin coating and then perform secondary spin coating, wherein the preliminary spin coating speed is 400rpm~500rpm, the spin coating time is 10s~15s, the secondary coating speed is 1900rpm~2000rpm, and the spin coating time is 30s~35s; Preferably, the initial spin coating speed is 500 rpm, the spin coating time is 10 s, the secondary coating speed is 2000 rpm, and the spin coating time is 30 s; After the infrared cutoff film coating is applied, a heat curing device is used to cure it to form an infrared cutoff film, wherein the curing temperature of the heat curing device is 110° C. to 120° C., and the curing time is 15 min to 20 min; Preferably, the curing temperature of the thermal curing equipment is 120°C and the curing time is 15 minutes; It should be noted that at layer 5 Coating with Layer 6 Providing a transition film coating between the coatings improves the antistatic performance and also avoids affecting the optical properties of the infrared cut-off film.

[0031] Furthermore, in step S230, the anti-reflection film coating is Coating, the thickness of the antireflection film coating is 100nm to 110nm; Preferably, the thickness of the antireflection film coating is 110 nm; Specifically, Coating for Nanoparticle dispersions; When the anti-reflection film coating is coated by a spin coating device, a preliminary spin coating is performed first and then a secondary spin coating is performed, wherein the preliminary spin coating speed is 400 rpm to 600 rpm, the spin coating time is 10 s to 15 s, the secondary coating speed is 2300 rpm to 2500 rpm, and the spin coating time is 30 s to 40 s; Preferably, the initial spin coating speed is 600 rpm, the spin coating time is 10 s, the secondary coating speed is 2500 rpm, and the spin coating time is 40 s; After the anti-reflection film coating is applied, a heat curing device is used to cure it to form an anti-reflection film, wherein the curing temperature of the heat curing device is 100° C. to 110° C. and the curing time is 10 min to 15 min; Preferably, the curing temperature of the thermal curing equipment is 100° C. and the curing time is 10 minutes.

[0032] Furthermore, in step S240, the antistatic film coating is an ITO coating, and the thickness of the antistatic film coating is 95nm to 100nm; Preferably, the antistatic film coating has a thickness of 100 nm; Specifically, the ITO coating is an ITO nanoparticle dispersion, the ITO nanoparticle dispersion contains 99% ITO nanoparticles and 1% carbon nanotubes, and the viscosity of the ITO nanoparticle dispersion is 30 mPa·s; When the antistatic film coating is coated by a spin coating device, a preliminary spin coating is performed first and then a secondary spin coating is performed, wherein the preliminary spin coating speed is 500rpm-700rpm, the spin coating time is 15s-20s, the secondary coating speed is 2000rpm-2200rpm, and the spin coating time is 30s-35s; Preferably, the initial spin coating speed is 700 rpm, the spin coating time is 15 s, the secondary coating speed is 2200 rpm, and the spin coating time is 30 s; After the antistatic film coating is applied, a heat curing device is used to cure it to form an antistatic film, wherein the curing temperature of the heat curing device is 140° C. to 150° C. and the curing time is 20 min to 25 min; Preferably, the curing temperature of the thermal curing equipment is 150°C and the curing time is 20 minutes; It should be noted that adding carbon nanotubes to the ITO nanoparticle dispersion significantly improves the antistatic performance and reduces the surface resistance.

[0033] Furthermore, in step S250, the waterproof and oil-proof film coating is a PTFE coating, and the thickness of the waterproof and oil-proof film coating is 50nm to 60nm; Preferably, the thickness of the waterproof and oil-proof film coating is 50 nm; Specifically, the PTFE coating is a PTFE solution, and the viscosity of the PTFE solution is 8 mPa·s; It should be noted that UV curing and plasma treatment improve the stability of the waterproof and oil-proof film coating; When the antistatic film coating is applied by a spin coating device, the spin coating speed is 1400 rpm to 1500 rpm, and the spin coating time is 15 s to 20 s; Preferably, the spin coating speed is 1500 rpm and the spin coating time is 20 s; After the waterproof and oil-proof film coating is applied, a UV curing device is used to cure it to form a waterproof and oil-proof film, wherein the UV curing device has a curing wavelength of 365 nm and a curing time of 30s to 40s during curing; Preferably, the curing time of the UV curing device is 30s; It should be noted that in the coating process of the above-mentioned infrared cutoff film coating, anti-reflection film coating and antistatic coating, the spin coating equipment can ensure the coating quality and uniformity through preliminary spin coating and secondary spin coating. The lower rotation speed during the preliminary spin coating can make the coating evenly distributed, and the higher rotation speed during the secondary spin coating can control the thickness and uniformity of the coating.

[0034] Step S300, performing a multi-stage thermal curing treatment on the composite film on the glass substrate; It should be noted that the multi-stage curing improves the stability and mechanical strength of the composite film, enhances the wear resistance and environmental resistance, reduces the stress in the composite film, and prevents the composite film from cracking.

[0035] Furthermore, the step S300 specifically includes: Step S310, performing multi-stage curing of low temperature curing, high temperature curing and ultra-high temperature curing on the composite film; Step S320, using low-power plasma treatment equipment to clean and enhance the surface of the cured composite film again; Step S330, cooling the composite film after the plasma treatment to room temperature at a cooling rate of 4°C / min to 5°C / min; Preferably, the cooling rate in step S330 is 5° C. / min.

[0036] Furthermore, in the step S310, the low temperature curing temperature is 100°C to 110°C, the curing time is 25min to 30min, and the heating rate is 4°C / min to 5°C / min; the high temperature curing temperature is 120°C to 130°C, the curing time is 1h to 1.2h, and the heating rate is 4°C / min to 5°C / min; the ultra-high temperature curing temperature is 140°C to 150°C, the curing time is 10min to 15min, and the heating rate is 4°C / min to 5°C / min; Preferably, the low-temperature curing temperature is 100°C, the curing time is 30 minutes, and the heating rate is 5°C / min; the high-temperature curing temperature is 120°C, the curing time is 1 hour, and the heating rate is 5°C / min; the ultra-high temperature curing temperature is 150°C, the curing time is 10 minutes, and the heating rate is 5°C / min.

[0037] Furthermore, in the step S320, the power of the plasma processing equipment is 40w-50w, and the processing time is 15s-20s; Preferably, the power of the plasma treatment equipment is 50w and the treatment time is 15s; It should be noted that through multi-stage curing, the microstructure of the composite film can be optimized, thereby reducing light scattering and improving optical transparency. Gradual curing can help reduce microscopic bubbles or impurities that may exist in the film layer and reduce optical loss. The gradual curing process can help seal the micropores in the film layer, improve its ability to resist moisture penetration, and increase its service life in a humid environment. At the same time, multi-stage curing and plasma treatment can further optimize the performance of the antistatic film and reduce the adverse effects of static electricity accumulation.

[0038] Step S400: coating a protective film on the cooled composite film.

[0039] It should be noted that the protective film disposed on the composite film also provides additional wear resistance and chemical protection for the composite film, thereby extending the service life of the infrared dielectric filter.

[0040] Furthermore, the step S400 specifically includes: Step S410, fixing the glass substrate on a rotating worktable and rotating it at a preset speed; Step S420, spraying the protective coating on the surface of the composite film along a circular spiral path through a fully automated electrostatic spraying system, and extending outward from the center of the composite film to the edge; Step S430: After the protective coating is sprayed, thermal curing is performed to obtain a protective film.

[0041] Furthermore, in the step S410, the rotation speed of the workbench is 10 rpm to 15 rpm; Preferably, the rotation speed of the workbench is 10 rpm; It should be noted that the rotation speed of the workbench at 10 rpm can ensure that the protective coating can be evenly distributed on the surface of the composite film during the spraying process, reducing the splashing of droplets caused by centrifugal force and ensuring the uniformity and density of the protective coating.

[0042] Furthermore, in the step S420, the protective coating comprises modified silicone resin, nano-aluminum oxide particles and isopropyl alcohol, and the thickness of the protective coating is 5 to 10 μm; The nozzle diameter in the fully automated electrostatic spraying system is 0.2-0.3 mm, the spray angle is 65°C-70°C, the spray flow rate is 5-10 mL / min, and the air source pressure is 0.2-0.3 MPa; When the nozzle is spraying in the fully automated electrostatic spraying system, the vertical distance between the nozzle and the composite film is 15 cm to 20 cm, and the spraying speed of the nozzle is 10 cm / s to 15 cm / s; Preferably, the vertical distance between the nozzle and the composite film is 15 cm, and the spraying speed of the nozzle is 10 cm / s; It should be noted that the protective coating is extended from the center to the edge through the annular spiral spraying path, avoiding the problem of excessive overlap or edge omission that occurs in traditional linear spraying, ensuring that the entire composite film surface obtains a uniform coating thickness. At the same time, the electrostatic spraying system utilizes the charged characteristics of the protective coating particles to enable them to be quickly adsorbed to the composite film surface to form a denser coating structure. The electrostatic spraying system cooperates with the annular spiral path to complete the coating of the entire composite film surface in a short time, thereby improving production efficiency. The electrostatic spraying technology combined with the thermal curing process also makes the protective coating more firmly bonded to the composite film surface, reducing the problem of coating peeling caused by mechanical friction or environmental influences. In addition, the nozzle diameter and spray angle ensure that the protective coating flow and coverage area are moderate to achieve uniform coating, the distance between the nozzle and the composite film and the spraying speed enhance the flatness and adhesion of the protective coating, and the protective coating with a thickness of 5 to 10 μm provides sufficient protection without affecting the optical properties.

[0043] Furthermore, in the step S430, the thermal curing temperature is 110°C to 120°C, the curing time is 30min to 40min, and the curing is performed at a heating rate of 4°C / min to 5°C / min; Preferably, the thermal curing temperature is 120°C, the curing time is 30 min, and the curing is performed at a heating rate of 5°C / min; After the protective coating is thermally cured, air circulation is performed in the thermal curing equipment for 5 minutes; Preferably, the airflow circulation in the heat curing equipment is performed for 4 to 5 minutes.

[0044] Embodiment 2: See also Figure 1 In this embodiment, a spin coating preparation method of an infrared cut-off filter comprises the following steps: Step S100, providing a glass substrate, and cleaning and pre-treating the surface of the glass substrate; It should be noted that by cleaning and pre-treating the glass substrate, the light scattering phenomenon caused by the rough surface of the glass substrate can be reduced, the transmittance can be improved, and the adhesion of the composite film to the glass substrate can be improved.

[0045] Furthermore, the step S100 specifically includes: Step S110, placing the glass substrate in an ultrasonic cleaning device, and ultrasonically cleaning the surface of the substrate using deionized water and a 2% NaOH solution; Step S120, placing the cleaned glass substrate in a hot air drying device and performing a drying process at a temperature of 70° C. to 80° C.; Step S130, placing the dried glass substrate in a clean room environment, controlling the ambient temperature and humidity to 20°C to 30°C and 40% to 45% humidity, and waiting for cooling to room temperature; Step S140, after cleaning the surface of the glass substrate by a plasma cleaning device, an ultra-thin transition layer is formed on the surface by a vapor deposition method; Step S150, finely polishing the surface of the glass substrate by an optical grinder; It should be noted that the ultra-thin transition layer is made of silicon oxide nanoparticles, and the thickness of the ultra-thin transition layer is 10nm. The ultra-thin transition layer can make the surface of the glass substrate have a better coating interface, so that the subsequent composite film can have a better adhesion effect when it is attached. When polishing the surface of the glass substrate, the polishing material is Suspension, polishing pressure is 50g / cm², polishing time is 10min, the surface roughness of the glass substrate is greater than 5nm (RMS). By polishing the surface of the glass substrate, the light scattering phenomenon caused by the rough surface of the glass substrate is reduced, and the transmittance is improved; Preferably, in step S120, the temperature of the hot air drying equipment is 80°C, and in step S130, the ambient temperature and humidity are controlled to be 25°C and 40%.

[0046] Step S200, coating a cured infrared cutoff film, an antireflection film, an antistatic film and a waterproof and oil-proof film on the glass substrate in sequence by a spin coating process to form a composite film on the glass substrate; It should be noted that by arranging a composite film composed of an infrared cutoff film, an anti-reflection film, an antistatic film and a waterproof and oil-proof film on a glass substrate, the composite film prepared according to the method can be applied to the glass substrate and put on the market, so that it has multiple functions, improves its comprehensive performance, and the mutual cooperation of different films improves the overall optical performance and surface characteristics.

[0047] Furthermore, the step S200 specifically includes: Step S210, pre-treating the coatings of the infrared cut-off film, the anti-reflection film, the antistatic film and the waterproof and oil-proof film by adjusting the viscosity and performing a heating treatment; Step S220, fixing the glass substrate on a rotating table of a spin coating device, and then allowing the rotating device to coat the infrared cutoff film coating on the surface of the glass substrate at a preset rotation speed and time, and curing the coating to obtain an infrared cutoff film; Step S230, allowing the rotating device to coat the anti-reflection film coating on the infrared cut-off film at a preset rotation speed and time, and to cure the anti-reflection film to obtain the anti-reflection film; Step S240, allowing the rotating device to coat the antistatic film coating on the antireflection film at a preset rotation speed and time, and solidify it to obtain an antistatic film; Step S250, allowing the rotating device to apply the waterproof and oil-proof film coating on the antistatic film according to a preset rotation speed and time, and solidify it to obtain a waterproof and oil-proof film; It should be noted that the infrared cutoff film provides excellent infrared shielding effect and reduces the color distortion of the sensor. It works synergistically with the anti-reflection film to ensure high transmittance. The anti-reflection film can improve the transmittance of visible light and reduce reflected light. It provides a uniform optical basis for the anti-static film. The anti-static film can prevent static electricity accumulation and dust adhesion to ensure long-term clear imaging. It cooperates with the waterproof and oil-proof film to improve outdoor adaptability. The waterproof and oil-proof film provides excellent hydrophobic and oleophobic properties to prevent stains from adhering and enhance the effect of the anti-static film in humid environments. The infrared cutoff film, anti-reflection film, anti-static film and waterproof and oil-proof film work synergistically during the application process to ensure imaging quality while having long-term stable environmental adaptability and high-performance reliability.

[0048] Furthermore, in step S220, the infrared cut-off film coating includes coating, Coating and ITO transition film coating; Specifically, Coating for Nanoparticles mixed dispersion, The nanoparticle dispersion contains 99.5% Nanoparticles and 0.5% ITO nanoparticles, The viscosity of the nanoparticle mixed dispersion was 20 mPa·s; Coating for Nanoparticles mixed dispersion, The nanoparticle dispersion contains 99.5% Nanoparticles and 0.5% ITO nanoparticles, The viscosity of the nanoparticle mixed dispersion is 20 mPa·s; the ITO transition film coating is indium tin oxide; When the infrared cut-off film coating is applied, five layers of 75 nm to 85 nm thick are applied alternately. Coating and coating, and in the 5th layer Coating with Layer 6 An ITO transition film coating with a thickness of 15nm to 25nm is applied between the coating layers; Preferably, Coating and The coating thickness is 80nm, and the ITO transition film coating thickness is 20nm; Coating by rotating equipment coating, When coating with ITO transition film, first perform preliminary spin coating and then perform secondary spin coating, wherein the preliminary spin coating speed is 400rpm~500rpm, the spin coating time is 10s~15s, the secondary coating speed is 1900rpm~2000rpm, and the spin coating time is 30s~35s; Preferably, the initial spin coating speed is 500 rpm, the spin coating time is 10 s, the secondary coating speed is 2000 rpm, and the spin coating time is 30 s; After the infrared cutoff film coating is applied, a heat curing device is used to cure it to form an infrared cutoff film, wherein the curing temperature of the heat curing device is 110° C. to 120° C., and the curing time is 15 min to 20 min; Preferably, the curing temperature of the thermal curing equipment is 120°C and the curing time is 15 minutes; It should be noted that through Nanoparticles mixed dispersion and ITO nanoparticles are added to the nanoparticle mixed dispersion to improve the infrared cutoff effect; in the 5th layer Coating with Layer 6 Providing a transition film coating between the coatings improves the antistatic performance and also avoids affecting the optical properties of the infrared cut-off film.

[0049] Furthermore, in step S230, the anti-reflection film coating is Coating, the thickness of the antireflection film coating is 100nm to 110nm; Preferably, the thickness of the antireflection film coating is 110 nm; Specifically, Coating for The nanoparticle dispersion needs to be subjected to low-frequency ultrasonic oscillation before coating, with an oscillation frequency of 20 kHz and a time of 5 minutes. The viscosity of the nanoparticle dispersion was 10 mPa·s; When the anti-reflection film coating is coated by a spin coating device, a preliminary spin coating is performed first and then a secondary spin coating is performed, wherein the preliminary spin coating speed is 400 rpm to 600 rpm, the spin coating time is 10 s to 15 s, the secondary coating speed is 2300 rpm to 2500 rpm, and the spin coating time is 30 s to 40 s; Preferably, the initial spin coating speed is 600 rpm, the spin coating time is 10 s, the secondary coating speed is 2500 rpm, and the spin coating time is 40 s; After the anti-reflection film coating is applied, a heat curing device is used to cure it to form an anti-reflection film, wherein the curing temperature of the heat curing device is 100° C. to 110° C. and the curing time is 10 min to 15 min; Preferably, the curing temperature of the thermal curing equipment is 100°C and the curing time is 10 minutes; It should be noted that the optical uniformity of the anti-reflection film coating is improved by low-frequency ultrasonic oscillation, further reducing the reflected light.

[0050] Furthermore, in step S240, the antistatic film coating is an ITO coating, and the thickness of the antistatic film coating is 95nm to 100nm; Preferably, the antistatic film coating has a thickness of 100 nm; Specifically, the ITO coating is an ITO nanoparticle dispersion, the ITO nanoparticle dispersion contains 99% ITO nanoparticles and 1% carbon nanotubes, and the viscosity of the ITO nanoparticle dispersion is 30 mPa·s; When the antistatic film coating is coated by a spin coating device, a preliminary spin coating is performed first and then a secondary spin coating is performed, wherein the preliminary spin coating speed is 500rpm-700rpm, the spin coating time is 15s-20s, the secondary coating speed is 2000rpm-2200rpm, and the spin coating time is 30s-35s; Preferably, the initial spin coating speed is 700 rpm, the spin coating time is 15 s, the secondary coating speed is 2200 rpm, and the spin coating time is 30 s; After the antistatic film coating is applied, a heat curing device is used to cure it to form an antistatic film, wherein the curing temperature of the heat curing device is 140° C. to 150° C. and the curing time is 20 min to 25 min; Preferably, the curing temperature of the thermal curing equipment is 150°C and the curing time is 20 minutes; It should be noted that adding carbon nanotubes to the ITO nanoparticle dispersion significantly improves the antistatic performance and reduces the surface resistance.

[0051] Furthermore, in step S250, the waterproof and oil-proof film coating is a PTFE coating, and the thickness of the waterproof and oil-proof film coating is 50nm to 60nm; Preferably, the thickness of the waterproof and oil-proof film coating is 50 nm; Specifically, the PTFE coating is a PTFE solution, which contains 99.9% PTFE and 0.1% Nanoparticles, PTFE solution viscosity is 8 mPa·s; It should be noted that when adding Nanoparticles form a hierarchical nanostructure in the waterproof and oil-proof film coating, which enhances the hydrophobicity and stain resistance of the waterproof and oil-proof film coating. UV curing and plasma treatment improve the stability of the waterproof and oil-proof film coating. When the antistatic film coating is applied by a spin coating device, the spin coating speed is 1400 rpm to 1500 rpm, and the spin coating time is 15 s to 20 s; Preferably, the spin coating speed is 1500 rpm and the spin coating time is 20 s; After the waterproof and oil-proof film coating is applied, a UV curing device is used to cure it to form a waterproof and oil-proof film, wherein the UV curing device has a curing wavelength of 365 nm and a curing time of 30s to 40s during curing; Preferably, the curing time of the UV curing device is 30s; It should be noted that in the coating process of the above-mentioned infrared cutoff film coating, anti-reflection film coating and antistatic coating, the spin coating equipment can ensure the coating quality and uniformity through preliminary spin coating and secondary spin coating. The lower rotation speed during the preliminary spin coating can make the coating evenly distributed, and the higher rotation speed during the secondary spin coating can control the thickness and uniformity of the coating.

[0052] Step S300, performing a multi-stage thermal curing treatment on the composite film on the glass substrate; It should be noted that the multi-stage curing improves the stability and mechanical strength of the composite film, enhances the wear resistance and environmental resistance, reduces the stress in the composite film, and prevents the composite film from cracking.

[0053] Furthermore, the step S300 specifically includes: Step S310, performing multi-stage curing of low temperature curing, high temperature curing and ultra-high temperature curing on the composite film; Step S320, using low-power plasma treatment equipment to clean and enhance the surface of the cured composite film again; Step S330, cooling the composite film after the plasma treatment to room temperature at a cooling rate of 4°C / min to 5°C / min; Preferably, the cooling rate in step S330 is 5° C. / min.

[0054] Furthermore, in the step S310, the low temperature curing temperature is 100°C to 110°C, the curing time is 25min to 30min, and the heating rate is 4°C / min to 5°C / min; the high temperature curing temperature is 120°C to 130°C, the curing time is 1h to 1.2h, and the heating rate is 4°C / min to 5°C / min; the ultra-high temperature curing temperature is 140°C to 150°C, the curing time is 10min to 15min, and the heating rate is 4°C / min to 5°C / min; Preferably, the low-temperature curing temperature is 100°C, the curing time is 30 minutes, and the heating rate is 5°C / min; the high-temperature curing temperature is 120°C, the curing time is 1 hour, and the heating rate is 5°C / min; the ultra-high temperature curing temperature is 150°C, the curing time is 10 minutes, and the heating rate is 5°C / min.

[0055] Furthermore, in the step S320, the power of the plasma processing equipment is 40w-50w, and the processing time is 15s-20s; Preferably, the power of the plasma treatment equipment is 50w and the treatment time is 15s; It should be noted that through multi-stage curing, the microstructure of the composite film can be optimized, thereby reducing light scattering and improving optical transparency. Gradual curing can help reduce microscopic bubbles or impurities that may exist in the film layer and reduce optical loss. The gradual curing process can help seal the micropores in the film layer, improve its ability to resist moisture penetration, and increase its service life in a humid environment. At the same time, multi-stage curing and plasma treatment can further optimize the performance of the antistatic film and reduce the adverse effects of static electricity accumulation.

[0056] Step S400: coating a protective film on the cooled composite film.

[0057] It should be noted that the protective film disposed on the composite film also provides additional wear resistance and chemical protection for the composite film, thereby extending the service life of the infrared dielectric filter.

[0058] Furthermore, the step S400 specifically includes: Step S410, fixing the glass substrate on a rotating worktable and rotating it at a preset speed; Step S420, spraying the protective coating on the surface of the composite film along a circular spiral path through a fully automated electrostatic spraying system, and extending outward from the center of the composite film to the edge; Step S430: After the protective coating is sprayed, thermal curing is performed to obtain a protective film.

[0059] Furthermore, in the step S410, the rotation speed of the workbench is 10 rpm to 15 rpm; Preferably, the rotation speed of the workbench is 10 rpm; It should be noted that the rotation speed of the workbench at 10 rpm can ensure that the protective coating can be evenly distributed on the surface of the composite film during the spraying process, reducing the splashing of droplets caused by centrifugal force and ensuring the uniformity and density of the protective coating.

[0060] Furthermore, in the step S420, the protective coating comprises modified silicone resin, nano-aluminum oxide particles and isopropyl alcohol, and the thickness of the protective coating is 5 to 10 μm; The nozzle diameter in the fully automated electrostatic spraying system is 0.2-0.3 mm, the spray angle is 65°C-70°C, the spray flow rate is 5-10 mL / min, and the air source pressure is 0.2-0.3 MPa; When the nozzle is spraying in the fully automated electrostatic spraying system, the vertical distance between the nozzle and the composite film is 15 cm to 20 cm, and the spraying speed of the nozzle is 10 cm / s to 15 cm / s; Preferably, the vertical distance between the nozzle and the composite film is 15 cm, and the spraying speed of the nozzle is 10 cm / s; It should be noted that the protective coating is extended from the center to the edge through the annular spiral spraying path, avoiding the problem of excessive overlap or edge omission that occurs in traditional linear spraying, ensuring that the entire composite film surface obtains a uniform coating thickness. At the same time, the electrostatic spraying system utilizes the charged characteristics of the protective coating particles to enable them to be quickly adsorbed to the composite film surface to form a denser coating structure. The electrostatic spraying system cooperates with the annular spiral path to complete the coating of the entire composite film surface in a short time, thereby improving production efficiency. The electrostatic spraying technology combined with the thermal curing process also makes the protective coating more firmly bonded to the composite film surface, reducing the problem of coating peeling caused by mechanical friction or environmental influences. In addition, the nozzle diameter and spray angle ensure that the protective coating flow and coverage area are moderate to achieve uniform coating, the distance between the nozzle and the composite film and the spraying speed enhance the flatness and adhesion of the protective coating, and the protective coating with a thickness of 5 to 10 μm provides sufficient protection without affecting the optical properties.

[0061] Furthermore, in the step S430, the thermal curing temperature is 110°C to 120°C, the curing time is 30min to 40min, and the curing is performed at a heating rate of 4°C / min to 5°C / min; Preferably, the thermal curing temperature is 120°C, the curing time is 30 min, and the curing is performed at a heating rate of 5°C / min; After the protective coating is thermally cured, air circulation is performed in the thermal curing equipment for 5 minutes; Preferably, the airflow circulation in the heat curing equipment is performed for 4 to 5 minutes.

[0062] Embodiment 3: See also Figure 2An infrared cutoff filter in this embodiment is prepared by the spin coating preparation method of the infrared cutoff filter as described in Example 1. The infrared cutoff filter includes a glass substrate 1 and a composite film 2, and a protective film 3 is arranged on the composite film 2. The composite film 2 includes an infrared cutoff film 21, an anti-reflection film 22, an antistatic film 23, and a waterproof and oil-proof film 24 from bottom to top.

[0063] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an infrared cut-off filter by spin coating, characterized in that: The preparation method comprises the following steps: Step S100, providing a glass substrate, and cleaning and pre-treating the surface of the glass substrate; Step S200, coating a cured infrared cutoff film, an antireflection film, an antistatic film and a waterproof and oil-proof film on the glass substrate in sequence by a spin coating process to form a composite film on the glass substrate; Step S300, performing a multi-stage thermal curing treatment on the composite film on the glass substrate; Step S400: coating a protective film on the cooled composite film.

2. The spin coating method for preparing an infrared cut-off filter according to claim 1, characterized in that: The step S100 specifically includes: Step S110, placing the glass substrate in an ultrasonic cleaning device, and ultrasonically cleaning the surface of the substrate using deionized water and a 2% NaOH solution; Step S120, placing the cleaned glass substrate in a hot air drying device and performing a drying process at a temperature of 70° C. to 80° C.; Step S130, placing the dried glass substrate in a clean room environment, controlling the ambient temperature and humidity to 20°C to 30°C and 40% to 45% humidity, and waiting for cooling to room temperature; Step S140, after cleaning the surface of the glass substrate by a plasma cleaning device, an ultra-thin transition layer is formed on the surface by a vapor deposition method; Step S150: finely polishing the surface of the glass substrate by an optical grinder.

3. The spin coating method for preparing an infrared cut-off filter according to claim 1, characterized in that: The step S200 specifically includes: Step S210, pre-treating the coatings of the infrared cut-off film, the anti-reflection film, the antistatic film and the waterproof and oil-proof film by adjusting the viscosity and performing a heating treatment; Step S220, fixing the glass substrate on a rotating table of a spin coating device, and then allowing the rotating device to coat the infrared cutoff film coating on the surface of the glass substrate at a preset rotation speed and time, and curing the coating to obtain an infrared cutoff film; Step S230, allowing the rotating device to coat the anti-reflection film coating on the infrared cut-off film at a preset rotation speed and time, and to cure the anti-reflection film to obtain the anti-reflection film; Step S240, allowing the rotating device to coat the antistatic film coating on the antireflection film at a preset rotation speed and time, and solidify it to obtain an antistatic film; Step S250: allowing the rotating device to coat the waterproof and oil-proof film coating on the antistatic film at a preset rotation speed and time, and to cure the coating to obtain a waterproof and oil-proof film.

4. The spin coating method for preparing an infrared cut-off filter according to claim 1, characterized in that: The step S300 specifically includes: Step S310, performing multi-stage curing of low temperature curing, high temperature curing and ultra-high temperature curing on the composite film; Step S320, using low-power plasma treatment equipment to clean and enhance the surface of the cured composite film again; Step S330, cooling the composite film after the plasma treatment to room temperature at a cooling rate of 4°C / min to 5°C / min.

5. The spin coating method for preparing an infrared cut-off filter according to claim 1, characterized in that: The step S400 specifically includes: Step S410, fixing the glass substrate on a rotating worktable and rotating it at a preset speed; Step S420, spraying the protective coating on the surface of the composite film along a circular spiral path through a fully automated electrostatic spraying system, and extending outward from the center of the composite film to the edge; Step S430: After the protective coating is sprayed, thermal curing is performed to obtain a protective film.

6. The spin coating method for preparing an infrared cut-off filter according to claim 3, characterized in that: In step S220, the infrared cut-off film coating includes coating, Coating and ITO transition film coating; When the infrared cut-off film coating is applied, five layers of 75 nm to 85 nm thick are applied alternately. Coating and coating, and in the 5th layer Coating with Layer 6 An ITO transition film coating with a thickness of 15nm to 25nm is applied between the coating layers; Coating by rotating equipment coating, When coating with ITO transition film, first perform preliminary spin coating and then perform secondary spin coating, wherein the preliminary spin coating speed is 400rpm~500rpm, the spin coating time is 10s~15s, the secondary coating speed is 1900rpm~2000rpm, and the spin coating time is 30s~35s; In step S230, the anti-reflection film coating is Coating, the thickness of the antireflection film coating is 100nm to 110nm; When the anti-reflection film coating is coated by a spin coating device, a preliminary spin coating is performed first and then a secondary spin coating is performed, wherein the preliminary spin coating speed is 400 rpm to 600 rpm, the spin coating time is 10 s to 15 s, the secondary coating speed is 2300 rpm to 2500 rpm, and the spin coating time is 30 s to 40 s; In step S240, the antistatic film coating is an ITO coating, and the thickness of the antistatic film coating is 95nm to 100nm; When the antistatic film coating is coated by a spin coating device, a preliminary spin coating is performed first and then a secondary spin coating is performed, wherein the preliminary spin coating speed is 500rpm-700rpm, the spin coating time is 15s-20s, the secondary coating speed is 2000rpm-2200rpm, and the spin coating time is 30s-35s; In step S250, the waterproof and oil-proof film coating is a PTFE coating, and the thickness of the waterproof and oil-proof film coating is 50nm to 60nm; When the antistatic film coating is coated by a spin coating device, the spin coating speed is 1400 rpm to 1500 rpm, and the spin coating time is 15 s to 20 s.

7. The spin coating method for preparing an infrared cut-off filter according to claim 3, characterized in that: In step S220, after the infrared cutoff film coating is applied, a heat curing device is used to cure it to form an infrared cutoff film, wherein the curing temperature of the heat curing device is 110° C. to 120° C. and the curing time is 15 min to 20 min. In step S230, after the anti-reflection film coating is applied, a thermal curing device is used to cure it to form an anti-reflection film, wherein the curing temperature of the thermal curing device is 100° C. to 110° C. and the curing time is 10 min to 15 min. In step S240, after the antistatic film coating is applied, a heat curing device is used to cure it to form an antistatic film, wherein the curing temperature of the heat curing device is 140° C. to 150° C. and the curing time is 20 min to 25 min. In step S250, after the waterproof and oil-proof film coating is applied, it is cured by ultraviolet curing equipment to form a waterproof and oil-proof film, wherein the curing wavelength of the ultraviolet curing equipment during curing is 365nm and the time is 30s to 40s.

8. The method for preparing an infrared cut-off filter by spin coating according to claim 4, characterized in that: In the step S310, the low temperature curing temperature is 100°C to 110°C, the curing time is 25min to 30min, and the heating rate is 4°C / min to 5°C / min; the high temperature curing temperature is 120°C to 130°C, the curing time is 1h to 1.2h, and the heating rate is 4°C / min to 5°C / min; the ultra-high temperature curing temperature is 140°C to 150°C, the curing time is 10min to 15min, and the heating rate is 4°C / min to 5°C / min; In the step S320, the power of the plasma processing equipment is 40W to 50W, and the processing time is 15s to 20s.

9. The method for preparing an infrared cut-off filter by spin coating according to claim 5, characterized in that: In the step S410, the rotation speed of the workbench is 10 rpm to 15 rpm; In the step S420, the protective coating comprises modified silicone resin, nano-aluminum oxide particles and isopropyl alcohol, and the thickness of the protective coating is 5 to 10 μm; The nozzle diameter in the fully automated electrostatic spraying system is 0.2-0.3 mm, the spray angle is 65°C-70°C, the spray flow rate is 5-10 mL / min, and the air source pressure is 0.2-0.3 MPa; When the nozzle is spraying in the fully automated electrostatic spraying system, the vertical distance between the nozzle and the composite film is 15 cm to 20 cm, and the spraying speed of the nozzle is 10 cm / s to 15 cm / s; In the step S430, the thermal curing temperature is 110°C to 120°C, the curing time is 30min to 40min, and the curing is performed at a heating rate of 4°C / min to 5°C / min; After the protective coating is thermally cured, air flow circulation is performed in the thermal curing equipment for 4 to 5 minutes.

10. An infrared cut-off filter, characterized in that: The infrared cutoff filter is prepared by the spin coating preparation method according to any one of claims 1 to 9, wherein the infrared cutoff filter comprises a glass substrate and a composite film, wherein the composite film comprises an infrared cutoff film, an antireflection film, an antistatic film, a waterproof and oil-proof film and a protective film from bottom to top.

Images