Extinction coating composition, extinction coating as well as preparation method and application of extinction coating

Abstract

The invention provides a matt coating composition, a matt coating and a preparation method and application thereof, the matt coating composition comprises the following components: a matt material, a surfactant, a dehydrating agent, polyamic acid and a solvent, and the matt coating composition has a high refractive index and a high matt coefficient through matching of the components. The coating can be coated on the surface of an optical glass element, and a coating is obtained after curing. The refractive index of the extinction coating at the wavelength of 633 nm is larger than 1.70, the extinction coefficient is larger than or equal to 0.09, it is measured that the interface reflectivity of the extinction coating and optical glass with the refractive index of 1.74 can be reduced to 0.026% in the visible spectrum range (400-800 nm), and the extinction coating is superior to current mainstream commercial extinction black paint. The matt coating is simple in preparation process and high in heat resistance, has a wide application prospect in the field of stray light suppression of an optical system, and is suitable for a high-temperature optical system.

Description

Technical Field

[0001] The invention belongs to the technical field of matte materials and relates to a matte coating composition, a matte coating and a preparation method and application thereof. Background Art

[0002] Optical systems such as camera lens groups, optical waveguide devices, and display devices contain a large number of optical glass components. For high-precision optical systems, these optical glass components usually have a high refractive index (n>1.7), such as lanthanide glass and heavy flint glass. When light is incident on the edge of an optical glass component of an optical system, according to the Fresnel equation (n 1 : Refractive index of glass, n 0 : refractive index of air; k 1 : Extinction coefficient of glass, k 0 : Extinction coefficient of air) It can be seen that due to the extreme mismatch between the optical constants of glass and air (refractive index n, extinction coefficient k), strong interface reflection will occur, forming stray light. Stray light is a harmful non-imaging light that will reduce the imaging quality of the optical system. In order to reduce the stray light caused by interface reflection, a black matte coating is usually applied to the edge of the optical glass element. When the optical constants of the matte coating and the optical glass element are relatively matched, the interface reflection of light can be significantly reduced, and the absorption of the incident light by the matte coating material is increased. Therefore, the matte coating has broad application prospects in the field of suppressing stray light in optical systems.

[0003] The research on matte coating of optical glass components began in the last century. Jin Zhenyu et al. proposed the design principle of matte black paint for lenses as follows: ① Suitable material composition: adjust the refractive index and extinction coefficient; ② Suitable preparation process: the filler size is as small as possible, less than one-fifth of the incident wavelength; ③ Suitable spectral absorber: ensure the absorption characteristics of black paint (Jin Zhenyu & Wang Haiyun. Research on black paint for optical lens. Optical Mechanics, 1987 (2): 43-50.). Eberhardt R. et al. listed a variety of automated methods for applying black paint (Eberhardt, R., Gebhardt, A., Weber, C., Risse, S. & Guyenot, V. New edge-blackening techniques for refractive optical elements. Optical Instrumentation & Systems Design, 1996: 659-666.). Japan has conducted a lot of research in the field of matte coatings for optical glass components. JP2011252949 discloses a coating preparation method using epoxy resin precursors, aromatic polyamines with a refractive index of 1.68 or higher, catalysts, and black particles, and applies it to optical glass components. The interface reflectivity is 0.05%, but the selected monomers are usually toxic, which is not conducive to large-scale production. JP2012246373 discloses a method for preparing a composite matte slurry whose raw materials are only matte agents and titanium oxide solutions, which are applied to the inner surface of optical glass components, and its micro-area interface reflectivity and ultraviolet light resistance are evaluated. However, due to the photochemical activity of titanium oxide, when the content is too high, there may be a risk of poor coating tolerance and failure. WO2022150470 discloses a high-refractive-index black paint material for the edge of a waveguide combiner and a coating method thereof. A coating with a refractive index higher than 1.70 is successfully synthesized by thermal curing and photocuring, but the effect of its interface reflectivity is not tested. WO2023139315 discloses a method for preparing a composite slurry of a siloxane polymer, titanium dioxide of different particle sizes and a black light-absorbing pigment, which is applied to the inner surface of an optical glass element and measures the reflectivity at the interface between the element and the coating to be less than 2%. However, since the UV-vis testing method is relatively indirect, it is difficult to accurately evaluate the anti-reflection performance of the coating, and the interface reflectivity is still relatively high.

[0004] At present, the matte coating matrix usually uses polymer materials such as epoxy resin, acrylic resin, and silicone rubber. The intrinsic refractive index of these materials is in the range of 1.4-1.6, which is poorly matched with the optical constants of high-refractive-index optical glass elements. It is necessary to use dispersion technology or chemical synthesis technology (such as sol-gel method, solvent thermal method, etc.) to introduce high-refractive-index elements or nanoparticles into the polymer matrix resin in order to regulate the optical constants of the resin. However, due to the relatively low intrinsic refractive index of the resin, a high content of high-refractive-index elements or nanoparticles needs to be introduced to significantly change its optical constants. High addition has a negative impact on chemical synthesis, uniform dispersion of nanoparticles, and mechanical properties of the resin. On the other hand, for high-temperature resistant industrial cameras in metallurgy, glass, petroleum, chemical industry, steel and other industries, the operating temperature can reach above 200°C, and the matte coating should have high-temperature resistance and good mechanical properties at high temperatures, while traditional matte coatings cannot meet the above needs.

[0005] Therefore, it is particularly important to develop a matte coating with simple preparation process, good matte performance and strong heat resistance. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a matte coating composition, a matte coating and a preparation method and application thereof. The matte coating of the present invention can provide extremely low reflectivity and high absorption performance in optical glass elements, effectively reduce the interference of stray light in optical systems, and expand its application in high-temperature optical systems.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In one aspect, the present invention provides a matte coating composition, which comprises the following components: a matte material, a surfactant, a dehydrating agent, polyamic acid (PAA) and a solvent.

[0009] The present invention uses matting material, surfactant, dehydrating agent and PAA solution as raw materials, and obtains a slurry with good uniformity by mixing, that is, obtains a matting coating composition. Then, it is evenly coated on the surface of an optical glass element, and the matting coating is obtained after curing. Under the modification of the surfactant, the matting material can be evenly dispersed in the PAA matrix; the dehydrating agent can make the PAA solution pre-imidized at room temperature, so as to achieve the imidization process at a lower thermal curing temperature; the high refractive index matting material is used, and the refractive index and extinction coefficient of the slurry can be coordinated and regulated by adjusting the content of the matting material, so as to achieve the matching of the refractive index with the optical glass element, and at the same time, the stray light is efficiently absorbed.

[0010] Preferably, the matting material is one of carbon black and carbon nanotubes or a mixture of the two, preferably carbon black.

[0011] Preferably, the matte material accounts for 1-25% of the total solid content of the matte coating composition, such as 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22% or 25%, etc.

[0012] Preferably, the primary particle size of the carbon black is between 20-50 nm, for example, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm or 50 nm.

[0013] Preferably, the surfactant is one of Triton, sodium dodecyl sulfate or a silane coupling agent or a combination of at least two thereof, preferably Triton.

[0014] Preferably, the surfactant accounts for 4-10% of the total solid content of the matte coating composition, such as 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0015] Preferably, the dehydrating agent is one of carbonyldiimidazole (CDI), acetic anhydride, trifluoroacetic anhydride, or a combination of at least two thereof, preferably carbonyldiimidazole (CDI).

[0016] Preferably, the dehydrating agent accounts for 0-25% of the total solid content of the matte coating composition, for example 0%, 1%, 3%, 5%, 8%, 10%, 13%, 15%, 18%, 20%, 22% or 25%.

[0017] Preferably, the weight average molecular weight of the polyamic acid is 50,000-80,000, for example, 50,000, 55,000, 60,000, 65,000, 70,000, 75,000 or 80,000.

[0018] Preferably, the polyimide accounts for 60-95% of the total solid content of the matte coating composition, such as 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%.

[0019] Preferably, the solvent is one or a combination of at least two of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, preferably N-methylpyrrolidone.

[0020] Preferably, the mass ratio of the solvent to the total solids in the matte coating composition is 5.5-7:1, for example, 5.5:1, 5.8:1, 6:1, 6.3:1, 6.5:1, 6.8:1 or 7:1, etc.

[0021] In another aspect, the present invention provides a method for preparing the matte coating composition as described above, the preparation method comprising the following steps:

[0022] The matte material, surfactant, dehydrating agent, polyamic acid and solvent are mixed to obtain the matte coating composition.

[0023] Preferably, the mixing comprises the following steps:

[0024] 1. Dissolving the matting material and the surfactant in a solvent and mixing and dispersing them;

[0025] II. dissolving polyamic acid in a solvent, and adding the obtained polyamic acid solution to the mixed solution obtained in step I to obtain solution A;

[0026] III. Dissolving a dehydrating agent in a solvent to obtain a solution B, and adding the solution B to the solution A for mixing to obtain the matte coating composition.

[0027] Preferably, the mixing method in step I is vacuum degassing and stirring.

[0028] Preferably, the specific process of the vacuum degassing and stirring is: stirring at a rate of 500-1000r / min (e.g., 500r / min, 600r / min, 700r / min, 800r / min, 900r / min or 1000r / min, etc.) for 3-5min (e.g., 3min, 4min or 5min) at normal pressure, and then stirring at a rate of 1500-2500r / min (e.g., 1500r / min, 1800r / min, 2000r / min, 2200r / min or 2500r / min, etc.) for 3-5min (e.g., 3min, 4min or 5min) under a vacuum degree of 20-60kPa (e.g., 20kPa, 30kPa, 40kPa, 50kPa or 60kPa, etc.).

[0029] Preferably, the solid content of the polyamic acid solution is 8-17%, for example 8%, 10%, 12%, 14%, 15% or 17%.

[0030] Preferably, the mixing method in step III is a combination of magnetic stirring and vacuum degassing stirring.

[0031] Preferably, under magnetic stirring, solution B is added dropwise into solution A to carry out a pre-imidization reaction, and then vacuum degassing and stirring are carried out.

[0032] Preferably, the specific process of the magnetic stirring is: stirring at a rate of 200-600 r / min (e.g., 200 r / min, 300 r / min, 400 r / min, 500 r / min or 600 r / min) for 20-30 min (e.g., 20 min, 25 min, 28 min or 30 min) at normal temperature and pressure.

[0033] Preferably, the vacuum degassing and stirring is performed at 2000 r / min for 5 minutes to obtain a mixed slurry.

[0034] In another aspect, the present invention provides a matte coating, which is obtained by curing the matte coating composition as described above.

[0035] On the other hand, the present invention provides a method for preparing the matte coating as described above, the preparation method comprising the following steps:

[0036] The matte coating composition is applied to the surface of an optical glass element and then cured to obtain a matte coating.

[0037] Preferably, the surface of the optical glass element is pretreated before coating, and the pretreatment is to ultrasonically clean the optical glass element in a cleaning agent for 3-10 minutes, for example, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes.

[0038] Preferably, the cleaning agent is one of deionized water, ethanol, isopropanol or acetone, or a combination of at least two of them, preferably ethanol.

[0039] Preferably, the coating is carried out by scraping or spraying, preferably by using a tetrahedral scraper.

[0040] Preferably, the coating controls the wet film thickness to be 50-1000 μm, for example, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm or 1000 μm.

[0041] Preferably, the curing is carried out in an oven.

[0042] Preferably, the curing temperature is 80-250°C, for example, 80°C, 100°C, 120°C, 140°C, 160°C, 180°C, 200°C, 230°C or 250°C.

[0043] Preferably, the curing time is 170-300 min, for example, 170 min, 190 min, 200 min, 230 min, 250 min, 280 min or 300 min.

[0044] Preferably, the curing is followed by cooling to obtain the matte coating.

[0045] As a preferred technical solution of the present invention, the method for preparing the matte coating comprises the following steps:

[0046] (1) Pre-treating the surface of the optical glass element: ultrasonically cleaning the optical glass element in a cleaning agent for 3-10 minutes;

[0047] (2) Preparation of matte composite slurry: mixing the matte material, surfactant, dehydrating agent and PAA solution in a solvent to obtain a matte composite slurry;

[0048] (3) The slurry is uniformly coated on the surface of the component, and the optical glass component coated with the slurry is placed in an oven for curing, and then cooled to obtain a matte coating.

[0049] In another aspect, the present invention provides use of the matte coating composition or matte coating as described above in optical glass.

[0050] The matte coating composition or matte coating of the present invention can be coated on the edge of optical glass, has strong heat resistance, has broad application prospects in the field of suppressing stray light in optical systems (such as lenses, optical waveguide devices, display equipment, etc.), and is suitable for high-temperature optical systems.

[0051] In another aspect, the present invention provides use of the matte coating composition or matte coating as described above in an optical lens, an optical waveguide device or a display apparatus.

[0052] The matte coating composition or matte coating of the present invention is suitable for high-temperature working environments, such as industrial high-temperature optical monitoring, aerospace optical sensing, high-temperature spectral analysis, etc.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] The matte coating composition of the present invention is obtained by combining components to obtain a composition with a high refractive index and extinction coefficient, which can be applied to the surface of an optical glass element and cured to obtain a coating. The refractive index of the matte coating at a wavelength of 633nm is greater than 1.70, and the extinction coefficient is greater than or equal to 0.09. It is measured that the interface reflectivity between the matte coating and the optical glass with a refractive index of 1.74 can be reduced to 0.026% in the visible spectrum range (400-800nm), which is better than the current mainstream commercial matte black paint. The matte coating of the present invention has a simple preparation process and strong heat resistance. It has a wide range of application prospects in the field of suppressing stray light in optical systems (such as lenses, optical waveguide devices, display equipment, etc.), and is suitable for high-temperature optical systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is an example of the present invention in a practical application scenario;

[0056] Among them, 1 is the lens of the lens group, 2 is the matte coating on the edge of the lens, 3 is the incident light, and 4 is the reflected light incident on the edge of the lens.

[0057] Figure 2 It is a schematic diagram of the interface reflectivity test of specific embodiments 1-6 of the present invention and comparative examples 1-3;

[0058] Figure 3 1. It is a graph of the reflectivity of the coating-glass interface in the visible light band of specific embodiments 1-6 of the present invention and comparative examples 1-3;

[0059] Figure 4 is a graph showing the change in interface reflectivity of specific embodiments 1 and 5 of the present invention and comparative examples 1 and 2 after aging at 250° C. for 24 hours;

[0060] Figure 5 This is a graph for evaluating adhesion using the hundred-grid method according to specific embodiment 1 of the present invention. DETAILED DESCRIPTION

[0061] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only used to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0062] Example 1

[0063] In this embodiment, a method for preparing a high temperature resistant matte coating applied to the edge of optical glass is provided, and its actual application scenario is illustrated as follows: Figure 1 As shown, the prepared matte coating is Figure 1 Corresponding to the part 2, to reduce the influence of reflection within the component on the optical system.

[0064] The preparation method comprises the following steps:

[0065] (1) First, the optical glass element is pretreated by placing it in ethanol and cleaning it under ultrasonication for 3 minutes to remove impurities such as oil on the surface of the element. After drying, it is fixed on a stainless steel plate.

[0066] (2) The composite material slurry is prepared as follows:

[0067] Weigh 0.03g of carbon black (CB) particles; weigh 0.07g of Triton; disperse the two in 1.5g of N-methylpyrrolidone (NMP), and mix them in a vacuum deaerator at 2000r / min for 5min to obtain a CB dispersion with good dispersion. Weigh 10g of 8% solid content polyamic acid (PAA) solution (prepared with NMP solvent in advance) and add the above CB dispersion. Add 400μL of CDI dispersion (containing 0.15g of CDI) under 400r / min magnetic stirring conditions, stir at room temperature for 30min, and then deaerate and stir in a vacuum deaerator at 2000r / min for 5min to obtain a mixed slurry.

[0068] (3) The matte coating preparation method is as follows:

[0069] The slurry was inverted on the surface of the optical glass element, and the dispersion was evenly coated on the surface of the optical glass element with the aid of a tetrahedral scraper. The tetrahedral scraper controlled the wet film thickness to be 1000 μm.

[0070] After the scraping is completed, the stainless steel template with the optical glass element fixed thereon is placed in an oven and cured at 120°C for 300 minutes. After cooling, a matte coating applied to the surface of the element is obtained.

[0071] The matte coating prepared in this example was tested as follows:

[0072] (1) The micro-area interface reflectivity of the coating-glass interface of the prepared matte coating was tested by micro-spectroscopy (goLite Solution, Shanghai Fuxiang Optics Co., Ltd.). The test schematic is shown in FIG. Figure 2 As shown;

[0073] (2) The transmittance of the prepared matte coating was tested using a UV-visible spectrophotometer (Lambda 1050+, PerkinElmer);

[0074] (3) The optical constants (refractive index and extinction coefficient) of the prepared matte coating were tested at a wavelength of 633 nm using an ellipsometer (Ellipsometer-EOPTICS-ME-LL, Wuhan Yiguang Technology Co., Ltd.);

[0075] (4) The adhesion performance of matte coating and optical glass components was evaluated by the Hundred Grid Method;

[0076] Test results such as Figure 3-4 , as shown in Table 1-2.

[0077] Example 2

[0078] The only difference between this embodiment and embodiment 1 is that the amount of carbon black particles added is 0.05 g, the amount of NMP solvent used for the initial mixing of the CB dispersion is 2 g, and the other conditions are the same as those in embodiment 1.

[0079] Example 3

[0080] The only difference between this embodiment and embodiment 1 is that the amount of carbon black particles added is 0.07 g, the amount of NMP solvent used for the initial mixing of the CB dispersion is 2.5 g, and the other conditions are the same as those in embodiment 1.

[0081] Example 4

[0082] The difference between this embodiment and embodiment 1 is that the amount of carbon black particles added is 0.01 g, and the NMP solvent used for the initial mixing of the CB dispersion is 1 g. A total of 5 g of a 17% solid content polyamic acid (PAA) solution is weighed and added to the above CB dispersion. Other conditions are the same as in embodiment 1.

[0083] Example 5

[0084] The only difference between this embodiment and embodiment 1 is that the amount of carbon black particles added is 0.01 g, and the NMP solvent used for the initial mixing of the CB dispersion is 1 g. Weigh a polyamic acid (PAA) solution with a solid content of 17%, a total of 5 g, and add the above CB dispersion. No CDI dispersion is added subsequently, and vacuum degassing and stirring treatment is directly performed. The curing conditions are: curing at 250°C for 170 minutes. Other conditions are the same as in embodiment 1.

[0085] Example 6

[0086] The only difference between this embodiment and embodiment 5 is that the surfactant Triton is not added, and other conditions are the same as those in embodiment 5.

[0087] Comparative Example 1

[0088] This comparative example uses the currently commercial Japanese black paint GT-7 to coat the surface of the optical glass element and cures it at 80° C. for 120 minutes.

[0089] Comparative Example 2

[0090] In this comparative example, the currently commercially available domestic black paint TR-1 was applied to the surface of the optical glass element and cured at 80° C. for 120 minutes.

[0091] Comparative Example 3

[0092] The difference from Example 5 is that this comparative example uses E51 epoxy resin, D230 polyetheramine as curing agent, acetone as solvent, uses the same mass fraction of CB and surfactant Triton as in Example 5, and uses the same vacuum degassing and stirring process, and finally cures at 100°C for 180 minutes to obtain.

[0093] The same method as in Example 1 was used to perform performance tests on the micro-region interface reflectivity and macroscopic transmittance in the visible light band (400-800 nm) of Examples 2-6 and Comparative Examples 1-3. The performance test results are shown in Table 1.

[0094] Table 1:

[0095] Micro-area interface reflectivity / % Macro transmittance / % Example 1 0.026 ～0 Example 2 0.028 ～0 Example 3 0.030 ～0 Example 4 0.027 ～0 Example 5 0.020 ～0 Example 6 0.027 ～0 Comparative Example 1 0.051 ～0 Comparative Example 2 0.078 ～0 Comparative Example 3 0.110 ～0

[0096] In Table 1, ~ means approximately equal to.

[0097] Table 2

[0098] Refractive Index Extinction coefficient Example 1 1.712 0.015 Example 2 1.732 0.029 Example 3 1.729 0.054 Example 4 1.694 0.009 Example 5 1.701 0.009 Example 6 1.722 0.007

[0099] As can be seen from Table 1, by comparing Examples 1-4, it can be found that as the CB content increases, the micro-region interface reflectivity will also increase. According to the Fresnel reflection law with an absorbing medium, this is due to the increase in the refractive index and extinction coefficient in the system after the addition of CB (Table 2). Substituting the corresponding optical constants into the Fresnel equation, it can be obtained that the interface reflectivity of Example 1 and the optical glass is the smallest, indicating that the higher the degree of matching. Comparing Example 5 and Example 4, under the same CB content conditions, the interface reflectivity of Example 5 is slightly lower than that of Example 4, but the method adopted in Example 5 is 250°C high temperature curing, which greatly limits its application in actual optical systems. Under the same CB content and curing conditions, the interface reflectivity of Example 6 is greater than that of Example 5. This is because the lack of surfactant modification of carbon black particles leads to uneven dispersion in the composite system, which ultimately results in a high interface reflectivity.

[0100] Comparative Examples 1 and 2 correspond to two commercial black paints from Japan and China, respectively, and Comparative Example 3 is a sample of epoxy resin used in the current mainstream matte black paint under the same mass fraction of matte material conditions as Example 5. It can be seen from Table 1 that the interface reflectances of the three are all higher than that of Example 1, which may be due to the low refractive index of the commercial black paint and epoxy resin themselves, which cannot match the high refractive index of the optical glass element.

[0101] like Figure 3 As shown, the interface reflectivity change curves of all embodiments and comparative examples in the visible light band (400-800nm) are displayed, and correspond to the visible light average interface reflectivity data listed in Table 1. It can be observed from the figure that the interface reflectivity of Examples 1-6 fluctuates little in the entire visible light band, showing excellent extinction stability, indicating that its optical properties are consistent over a wide wavelength range. However, Comparative Examples 1-3 show obvious reflectivity peak fluctuations in the wavelength range of 600-700nm, which may be related to the structural defects or light absorption characteristics of the material. This result shows that the embodiments have significant advantages over the comparative examples in suppressing interface reflection and improving the extinction effect. The heat resistance of Examples 1, 5 and Comparative Examples 1, 2 is as shown in FIG. Figure 4 As shown, under the condition of aging at 250° C. for 24 hours, the interface reflectivity between the black paint coating of Example 1 and the optical glass element only changes by 0.002%, which is better than Example 5 and Comparative Examples 1 and 2, and has better thermal stability.

[0102] The matte coating of Example 1 was tested by the cross-cut method. After the test, it was found that the edges of the cross-cuts were intact and no coating fell off, which proved that it had good adhesion.

[0103] It can be seen that the present invention has developed a high temperature resistant matte coating for optical glass edges, which has a high refractive index (n>1.70), has an extremely low interface reflectivity (0.026%) at the interface with high refractive index optical glass elements in the visible light band (400-800nm), and is opaque. At the same time, it has good heat resistance and adhesion ( Figure 5 ) and other characteristics.

[0104] The present invention uses the above examples to illustrate the preparation method of the high temperature resistant matt coating applied to the edge of optical glass of the present invention, but is not limited to the above examples, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A matte coating composition, characterized in that: The matte coating composition comprises the following components: a matte material, a surfactant, a dehydrating agent, polyamic acid and a solvent.

2. The matte coating composition according to claim 1, characterized in that: The matting material is one of carbon black and carbon nanotubes or a mixture of the two, preferably carbon black; Preferably, the matte material accounts for 1-25% of the total solid content of the matte coating composition; Preferably, the primary particle size of the carbon black is 20-50 nm.

3. The matte coating composition according to claim 1 or 2, characterized in that: The surfactant is one or a combination of at least two of Triton, sodium dodecyl sulfate or a silane coupling agent, preferably Triton; Preferably, the surfactant accounts for 4-10% of the total solid content of the matte coating composition; Preferably, the dehydrating agent is one or a combination of at least two of carbonyldiimidazole, acetic anhydride, and trifluoroacetic anhydride, preferably carbonyldiimidazole; Preferably, the dehydrating agent accounts for 0-25% of the total solid content of the matte coating composition; Preferably, the weight average molecular weight of the polyamic acid is 50000-80000; Preferably, the polyimide accounts for 60-95% of the total solid content of the matte coating composition; Preferably, the solvent is one or a combination of at least two of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, preferably N-methylpyrrolidone; Preferably, the mass ratio of the solvent to the total solids in the matte coating composition is 5.5-7:

1.

4. The method for preparing the matte coating composition according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: The matte material, surfactant, dehydrating agent, polyamic acid and solvent are mixed to obtain the matte coating composition.

5. The preparation method according to claim 4, characterized in that: The mixing comprises the following steps:

1. Dissolving the matting material and the surfactant in a solvent and mixing and dispersing them; II. dissolving polyamic acid in a solvent, and adding the obtained polyamic acid solution to the mixed solution obtained in step I to obtain solution A; III. dissolving a dehydrating agent in a solvent to obtain a solution B, and adding the solution B to the solution A for mixing to obtain the matte coating composition; Preferably, the mixing method in step I is vacuum degassing and stirring; Preferably, the specific process of vacuum degassing and stirring is: stirring at a rate of 500-1000 r / min for 3-5 min under normal pressure, and then stirring at a rate of 1500-2500 r / min for 3-5 min under a vacuum degree of 20-60 kPa; Preferably, the solid content of the polyamic acid solution is 8-17%; Preferably, the mixing method in step III is a combination of magnetic stirring and vacuum degassing stirring; Preferably, under magnetic stirring, solution B is added dropwise into solution A to perform a pre-imidization reaction, and then vacuum degassing and stirring are performed; Preferably, the specific process of the magnetic stirring is: stirring at a rate of 200-600 r / min for 20-30 min at normal temperature and pressure; Preferably, the vacuum degassing and stirring is performed at 2000 r / min for 5 minutes to obtain a mixed slurry.

6. A matte coating, characterized in that: The matte coating is obtained by curing the matte coating composition according to any one of claims 1 to 4.

7. The method for preparing a matte coating according to claim 6, characterized in that: The preparation method comprises the following steps: The matte coating composition is applied to the surface of an optical glass element and then cured to obtain a matte coating.

8. The preparation method according to claim 7, characterized in that: The surface of the optical glass element is pretreated before coating, wherein the pretreatment is to ultrasonically clean the optical glass element in a cleaning agent for 3-10 minutes; Preferably, the cleaning agent is one or a combination of at least two of deionized water, ethanol, isopropanol or acetone, preferably ethanol; The coating method is scraping or spraying, preferably scraping with a tetrahedron scraper; Preferably, the coating controls the wet film thickness to be 50-1000 μm; Preferably, the curing is carried out in an oven; Preferably, the curing temperature is 80-250°C; Preferably, the curing time is 170-300 min; Preferably, the curing is followed by cooling to obtain the matte coating.

9. Use of the matte coating composition according to any one of claims 1 to 4 or the matte coating according to claim 6 in optical glass.

10. Use of the matte coating composition according to any one of claims 1 to 4 or the matte coating according to claim 6 in an optical lens, an optical waveguide device or a display device.

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