An extinction coating, a preparation method thereof, and a light-shielding film for optical instruments

Abstract

The present invention discloses a matting coating, a preparation method thereof and a light-shielding film for optical instruments, belonging to the technical field of light-shielding films. The raw materials for preparing the matting coating include the following components: polyacrylate polyol, polyester polyol, polyether-type polyol, matting powder, carbon black, curing agent, phosphor and additives. The particle size of the matting powder is 2 to 10 microns. By using polyacrylate polyol to modify polyurethane, the light-shielding film for optical instruments prepared by the present invention meets the matting corrosion process, the coating does not fall off or deform under thermal shock, is wear-resistant, high-temperature and high-humidity resistant, and also ensures that the reflectance and optical density do not change. After matting corrosion, the surface of the coating is hydrophobic and non-sticky, which is beneficial to optical stability. Fluorescent powder is also added on one side to facilitate customers to distinguish between the A side and the B side for use.

Description

Technical Field

[0001] The present invention relates to the technical field of light-shielding films, and in particular to a matte coating, a preparation method thereof, and a light-shielding film for optical instruments Background Art

[0002] With the rapid update and iteration of intelligent digital products and the higher requirements for the precision and rigor of scientific experiments, the demand for light-shielding materials for optical lenses is becoming wider, and the performance requirements for light-shielding materials are getting higher. In order to suppress the influence of external light on the imaging quality and avoid poor imaging phenomena such as ghosting and vignetting, it is necessary to improve the light extinction effect of the surface coating in the optical component

[0003] In order to improve the light-shielding property and sliding property of the light-shielding film, a large amount of lubricant and matte powder need to be added to the light-shielding ink. Currently, in the prior art, a large amount of carbon black, lubricant, matte powder and other fine particles are added to improve the sliding property and light-shielding property of the light-shielding film. However, due to the addition of a large amount of fine particles, the adhesion and wear resistance of the ink coating of the light-shielding film on the polyester base film are poor. There is also the use of large-density fluororesin particles as lubricants to improve the sliding property of the light-shielding film. However, the fluororesin particles are not easily dispersed, and when the thickness of the ink coating is thin, the appearance of the coating is poor, resulting in poor light-shielding property and sliding property

[0004] Therefore, it is necessary to provide a matte coating that is resistant to strong alkali, friction and has good coating adhesion to solve the above problems Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a matte coating, which can effectively improve the adhesion and surface hydrophobicity of the matte coating, and improve the friction resistance and strong alkali resistance of the light-shielding film

[0006] The present invention also provides a preparation method of the above matte coating

[0007] The present invention also provides a light-shielding film for optical instruments

[0008] The present invention also provides a preparation method of the light-shielding film for optical instruments

[0009] The first aspect of the present invention provides a matte coating. By weight, the preparation raw materials of the matte coating include the following components

[0010] 60-80 parts of polyacrylate polyol

[0011] 5-20 parts of polyester polyol

[0012] 5-20 parts of polyether polyol

[0013] Matting powder: 4 - 13 parts; the particle size of the matting powder is 2 - 10 microns;

[0014] Carbon black 6 - 18 parts;

[0015] Curing agent 15 - 50 parts;

[0016] Phosphor 0.55 - 1.5 parts;

[0017] Auxiliary agent 0.2 - 5 parts.

[0018] The matting coating according to the first aspect embodiment of the present invention has at least the following beneficial effects:

[0019] The matting coating described in the present invention has good optical properties and can effectively reduce phenomena such as glare and ghosting caused by stray light in optical devices;

[0020] The matting coating described in the present invention has good adhesion and alkali resistance, and still has good adhesion performance and optical stability after being treated with strong alkali;

[0021] The coating formed by the matting coating described in the present invention has good leveling property, small dynamic and static friction coefficients on the coating surface, and good wear resistance.

[0022] The polyacrylate polyol adopted in the present invention has the functions of improving the alkali resistance, wear resistance and weather resistance of the coating; the polyester polyol can improve the adhesion of the coating; the polyether polyol can improve the flexibility of the coating. The present invention uses polyacrylate polyol to modify polyester polyol and polyether polyol, and the synergistic effect between the preparation raw materials improves the alkali resistance, friction resistance and adhesion of the coating.

[0023] Through the synergistic use of various materials, the present invention meets the matting corrosion process. The coating does not fall off or deform under thermal shock, is wear-resistant, high-temperature and high-humidity resistant, and also ensures that the reflectance and optical density remain unchanged. After matting corrosion, the coating surface is hydrophobic and non-sticky, which is beneficial to optical stability. Adding phosphor on one side also facilitates customers to distinguish between A and B sides.

[0024] Preferably, by weight, the preparation raw materials of the matting coating include the following components:

[0025] Polyacrylate polyol 65 - 76 parts;

[0026] Polyester polyol 7 - 15 parts;

[0027] Polyether polyol 8 - 15 parts;

[0028] Matting powder: 4 - 10 parts; the particle size of the matting powder is 4 - 6 microns;

[0029] Carbon black 8 - 15 parts;

[0030] 15 - 50 parts of curing agent;

[0031] 0.8 - 1 part of phosphor powder;

[0032] 1 - 5 parts of auxiliary agent.

[0033] More preferably, by weight, the raw materials for preparing the matting coating include the following components:

[0034] 75 parts of polyacrylate polyol;

[0035] 7 parts of polyester polyol;

[0036] 8 parts of polyether polyol;

[0037] Matting powder: 5 parts; the particle size of the matting powder is 4 - 6 microns;

[0038] 10 parts of carbon black;

[0039] 18 parts of curing agent;

[0040] 1 part of phosphor powder;

[0041] 5 parts of auxiliary agent.

[0042] According to some embodiments of the present invention, the mass ratio of the polyester polyol to the polyether polyol is 1:(1 - 2), for example, specifically it can be about 1:1, 1:1.5, 1:2.

[0043] According to some embodiments of the present invention, the hydroxyl value content of the polyacrylate polyol is 2% - 4.5%; for example, specifically it can be about 2%, 2.1%, 2.5%, 2.8%, 3%, 3.5%, 4.2%, 4.5%.

[0044] According to some embodiments of the present invention, the polyacrylate polyol can be selected from, for example, 1184SS - 51 acrylic polyol (hydroxyl value content is 2.0%) of Zahn Chemie AG and 1753 acrylic polyol (hydroxyl value content is 4.2%), OLESTER Q519 acrylic polyol (hydroxyl value content is about 2.8%) of Mitsui Chemicals, Inc., Japan, and Joncryl 911 acrylate polyol (hydroxyl value content is about 2.1%) of BASF Corporation.

[0045] The polyacrylate polyol adopted has good performance balance, high gloss potential, improves appearance while enhancing chemical resistance, mechanical resistance, outdoor durability and scratch resistance.

[0046] According to some embodiments of the present invention, the hydroxyl value content of the polyester polyol is 1.6% to 3.5%; specifically, for example, it can be approximately 1.6%, 2%, 2.5%, 2.8%, 3%, 3.5%.

[0047] According to some embodiments of the present invention, the polyester polyol can be selected, such as DESMOPHEN 1652 polyester polyol (hydroxyl value content is 1.6%) and DESMOPHEN 670 polyester polyol (hydroxyl value content is 3.6%) of Covestro, etc.

[0048] According to some embodiments of the present invention, the polyether polyol includes polytetrahydrofuran polyol, specifically it can be polytetrahydrofuran diol.

[0049] According to some embodiments of the present invention, the hydroxyl value content of the polyether polyol is 1.8% to 3.6%; specifically, for example, it can be approximately 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.6%.

[0050] According to some embodiments of the present invention, the average molecular weight of the polyether polyol is 1000 to 2000.

[0051] Such as PTMEG1000 polytetrahydrofuran diol (hydroxyl value content is 3.2% to 3.6%) and PTMEG2000 polytetrahydrofuran diol (hydroxyl value content is 1.8% to 2%) of Jining Huakai Resin Co., Ltd., etc.

[0052] Generally, polyurethane coatings are prepared by reacting polyester or polyether polyols with isocyanates. However, in the present invention, polyacrylate polyols are introduced into the polyester and polyether polyols, which can improve the alkali resistance and abrasion resistance of the coating.

[0053] According to some embodiments of the present invention, the curing agent is an aliphatic isocyanate curing agent, such as HT-100 of Wanhua Chemical Group Co., Ltd. of Yantai, Desmodur N 3300 of Covestro, 1,4-cyclohexane diisocyanate of Shandong Lanshi New Materials Co., Ltd., IPDI isophorone diisocyanate of Shandong Tonglan Chemical Co., Ltd., etc.

[0054] According to some embodiments of the present invention, the flatting agent is at least one of an organic flatting agent and an inorganic flatting agent.

[0055] In the present invention, a mixture of an organic flatting agent and an inorganic flatting agent is used, which not only maintains the flatting effect but also improves the hand feeling, hardness, and scratch resistance of the coating.

[0056] According to some embodiments of the present invention, the particle size of the matting powder is 2 to 9.5 micrometers; for example, specifically, it can be approximately 2 micrometers, 3 micrometers, 4 micrometers, 4.5 micrometers, 5 micrometers, 6 micrometers, 7 micrometers, 8 micrometers, 9 micrometers, 9.5 micrometers.

[0057] According to some embodiments of the present invention, the particle size of the organic matting powder is 4 to 7 micrometers. For example, M162 organic matting powder (particle size of 6 micrometers) from Dongguan Guangyue New Material Technology Co., Ltd. and S6 organic matting powder (particle size of 5 micrometers) from Dongguan Shengyuan Chemical Co., Ltd. can be selected, etc.

[0058] According to some embodiments of the present invention, the particle size of the inorganic matting powder is 3 to 9.5 micrometers. For example, ACEMATT TS 100 silica from Evonik Degussa (particle size of 9.5 micrometers) and E-1011 inorganic matting powder from Tosoh Corporation of Japan (particle size of 4 micrometers) can be selected, etc.

[0059] According to some embodiments of the present invention, the mass ratio of the organic matting powder to the inorganic matting powder is 1:1 to 3. For example, specifically, it can be approximately 1:1, 1:1.5, 1:2, 1:2.5, 1:3, etc.

[0060] Among the inorganic matting powders, silica-based matting powders are easy to disperse and can be added at any stage during the production process. They have excellent matting effects, extremely high transparency, high purity, and low conductivity. However, they may affect the matting effect during the grinding process; organic matting powders are polymers with unique structures, and the molecules contain special groups that can crosslink with the coating, which can improve the scratch resistance of the coating surface. The reactions that occur during the formation of the paint film fundamentally improve the elasticity, feel, surface hardness, gloss retention, and scratch resistance of the paint film. The combined use of organic matting powder and inorganic matting powder is complementary and has a good effect.

[0061] According to some embodiments of the present invention, the carbon black is at least one of high pigment carbon black and conductive carbon black.

[0062] According to some embodiments of the present invention, the particle size of the carbon black is 10 to 100 nanometers.

[0063] According to some embodiments of the present invention, the particle size of the carbon black is 10 to 50 nanometers. For example, specifically, it can be approximately 10 nanometers, 20 nanometers, 30 nanometers, 40 nanometers, 50 nanometers, etc.

[0064] According to some embodiments of the present invention, the carbon black can be selected from EMPEROR 1600 high pigment carbon black of Cabot Corporation, high pigment carbon black MA100 of Mitsubishi of Japan, VXC72R conductive carbon black of Cabot Corporation, P100 conductive carbon black of Tianjin Zhengning New Material Technology Co., Ltd., TYT-5A conductive carbon black of Tianjin Tianyi Century Chemical Products Technology Development Co., Ltd., etc.

[0065] Among them, the conductive carbon black can reduce the surface resistance and improve the antistatic property; the high pigment carbon black can improve the light shielding property.

[0066] According to some embodiments of the present invention, the auxiliary agent includes at least one of a leveling agent and a dispersant.

[0067] According to some embodiments of the present invention, the leveling agent includes at least one of an acrylic leveling agent and a polyurethane leveling agent. For example, specifically, it can be at least one of the leveling agents KMT-5519 and KMT-5510 of Foshan Kening New Material Co., Ltd.

[0068] Preferably, the leveling agent is the KMT-5519 leveling agent.

[0069] According to some embodiments of the present invention, the dispersant includes at least one of the SDJ8110 dispersant of Guangdong Sanjia New Material Technology Co., Ltd. and the GS-2400 dispersant of Guangzhou Jingyi New Material Co., Ltd.

[0070] Preferably, the dispersant is the GS-2400 dispersant.

[0071] According to some embodiments of the present invention, the phosphor is a colorless phosphor.

[0072] According to some embodiments of the present invention, the particle size of the phosphor is 5 to 10 microns.

[0073] According to some embodiments of the present invention, the colorless phosphor is a phosphor that can emit bright light under ultraviolet light irradiation with a wavelength of 200 to 300 nm and the color disappears after leaving the ultraviolet light source, such as at least one of the invisible colorless ultraviolet-excited pigments produced by Shenzhen Aobo Security Anti-counterfeiting Technology Co., Ltd. and the ultraviolet colorless to colored light-changing powder produced by Shenzhen Yaodesheng Technology Co., Ltd.

[0074] According to some embodiments of the present invention, the raw materials for preparing the matting coating further include a solvent.

[0075] According to some embodiments of the present invention, the solvent includes at least one of methyl ethyl ketone, butyl acetate, and toluene.

[0076] Preferably, the solvent is ethyl acetate and methyl ethyl ketone.

[0077] According to some embodiments of the present invention, by weight, the content of the solvent is 100 - 500 parts.

[0078] Preferably, by weight, the content of the solvent is 100 - 300 parts.

[0079] The second aspect of the present invention provides a method for preparing a matting coating, and the preparation method includes the following steps:

[0080] Mix the raw materials for preparing the matting coating in proportion, and perform stirring and sanding treatments to obtain the matting coating.

[0081] According to some embodiments of the present invention, the preparation method specifically includes the following steps:

[0082] 1) Mix and stir the solvent, additives, matting powder and carbon black to obtain Component A;

[0083] 2) Add polyacrylate polyol, polyester polyol and polytetrahydrofuran diol to Component A;

[0084] 3) Sand the material in step 2), and add a curing agent and stir evenly to obtain the matting coating.

[0085] According to some embodiments of the present invention, in step 1), the stirring time is 0.8 - 1.5 h.

[0086] Preferably, in step 1), the stirring time is 1 h.

[0087] According to some embodiments of the present invention, in step 3), the machine for the sanding step is selected as a nano-dispersion sand mill.

[0088] According to some embodiments of the present invention, in step 3), the sanding time is 1 - 3 h.

[0089] Preferably, in step 3), the sanding time is 2 h.

[0090] The third aspect of the present invention provides a light-shielding film for an optical instrument, and the light-shielding film for an optical instrument includes a carrier base film, a first matting layer provided on one side of the carrier base film, and a second matting layer provided on the other side of the carrier base film; the raw materials for preparing the matting layer include the above-mentioned matting coating.

[0091] According to some embodiments of the present invention, the matting layers on the two opposite surfaces of the carrier base film are the first matting layer and the second matting layer respectively.

[0092] According to some embodiments of the present invention, the phosphor is present in only one of the first extinction layer and the second extinction layer.

[0093] Adding a phosphor can more conveniently and quickly distinguish different sides of the light-shielding film during use.

[0094] According to some embodiments of the present invention, the thickness of a single extinction layer is 2 to 20 micrometers.

[0095] According to some embodiments of the present invention, the thickness of the carrier base film is 40 to 200 micrometers, and for example, it can be about 40 micrometers, 50 micrometers, 60 micrometers, 80 micrometers, 100 micrometers, 120 micrometers, 150 micrometers, 180 micrometers, 200 micrometers, etc.

[0096] According to some embodiments of the present invention, the carrier base film includes at least one of a black polyester film, a transparent polyester film, a black polycarbonate film, a transparent polycarbonate film, a black polyimide film, a transparent polyimide film, a brown polyimide film, a black polyamideimide film, and a transparent polyamideimide film.

[0097] Preferably, the carrier base film is at least one of a black polyester film and a transparent polyester film.

[0098] According to some embodiments of the present invention, the coating method of the extinction coating is at least one of slot extrusion coating, gravure coating, knife coating, and gravure roll coating.

[0099] Preferably, the coating method of the extinction coating is at least one of slot extrusion coating and gravure coating.

[0100] More preferably, the coating method of the extinction coating is gravure coating.

[0101] Gravure coating can coat a very thin coating onto a very thin material. The gravure roll has a small diameter and light weight. It is convenient to replace the gravure roll for different coating amounts. At the same time, reverse coating can obtain a relatively flat coating with a uniform distribution of the coating amount.

[0102] The fourth aspect of the present invention provides a method for preparing the above-mentioned light-shielding film for an optical instrument, and the preparation method includes the following steps:

[0103] Coat the extinction coating on one surface of the carrier base film, dry it to form a first extinction layer; then coat the extinction coating on the other opposite surface of the carrier base film, dry it to form a second extinction layer. After curing, the light-shielding film for the optical instrument is obtained.

[0104] According to some embodiments of the present invention, the drying temperature is 60 to 160 °C, for example, it can be approximately 60 °C, 100 °C, 120 °C, 125 °C, 130 °C, 135 °C, 140 °C, 145 °C, 150 °C, 160 °C, etc.

[0105] According to some embodiments of the present invention, the drying time is 2 to 5 minutes, for example, it can be approximately 2 minutes, 3 minutes, 4 minutes, 5 minutes, etc.

[0106] If the baking time is short and the temperature is too low, the solvent volatilizes incompletely, resulting in the coating being sticky after winding and curing, which will affect the appearance and optical properties.

[0107] According to some embodiments of the present invention, the curing temperature is 20 to 65 °C, for example, it can be approximately 20 °C, 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 65 °C, etc.

[0108] According to some embodiments of the present invention, the curing time is 20 to 60 hours, for example, it can be approximately 20 hours, 25 hours, 30 hours, 35 hours, 40 hours, 45 hours, 50 hours, 55 hours, 60 hours, etc.

[0109] Unless otherwise specified, the "about" in the present invention actually means that the allowable error is within the range of ±2%, for example, about 100 is actually 100 ± 2% × 100.

[0110] Other features and advantages of the present invention will be described in the subsequent specification, and, in part, will become apparent from the specification or be understood by implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0111] The above and / or additional aspects and advantages of the present invention will become apparent and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0112] Figure 1 It is a schematic structural diagram of the light-shielding composite film of the optical instrument in the test example of the present invention;

[0113] Figure 2 It is a process flow chart of the preparation of the light-shielding composite film of the optical instrument in the test example of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0114] The following will clearly and completely describe the concept of the present invention and the technical effects generated in combination with the embodiments to fully understand the purpose, features, and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0115] Example 1

[0116] This example provides a preparation method of a matting coating, and the preparation method includes the following steps:

[0117] According to the weight parts of the preparation raw materials shown in Table 1

[0118] 1) Mix and stir the solvent, auxiliary agent, matting powder and carbon black to obtain Component A;

[0119] 2) Mix and add polyacrylate polyol, polyester polyol and polytetrahydrofuran diol into Component A;

[0120] 3) Grind the materials in step 2), add a curing agent and stir evenly to obtain the matting coating.

[0121] Example 2

[0122] This example provides a preparation method of a matting coating, and the preparation method includes the following steps:

[0123] According to the weight parts of the preparation raw materials shown in Table 1

[0124] 1) Mix and stir the solvent, auxiliary agent, matting powder and carbon black to obtain Component A;

[0125] 2) Mix and add polyacrylate polyol, polyester polyol and polytetrahydrofuran diol into Component A;

[0126] 3) Grind the materials in step 2), add a curing agent and stir evenly to obtain the matting coating.

[0127] Comparative Example 1

[0128] The difference between this comparative example and Example 1 is that polyacrylate polyol is not added.

[0129] Comparative Example 2

[0130] The difference between this comparative example and Example 1 is that polyester polyol is not added.

[0131] Comparative Example 3

[0132] The difference between this comparative example and Example 1 is that polyether polyol is not added.

[0133] Comparative Example 4

[0134] The difference between this comparative example and Example 1 is that organic matting agent is not added.

[0135] Table 1 Weight parts of the preparation raw materials of Examples 1-2 and Comparative Examples 1-4

[0136]

[0137]

[0138] Test Example

[0139] A light-shielding composite film for an optical instrument, using the matting coatings prepared in Examples 1-2 and Comparative Examples 1-4. The structural schematic diagram of the light-shielding composite film for the optical instrument is as Figure 1 shown.

[0140] The preparation steps of the light-shielding composite film for the optical instrument include: selecting a black polyester film as the carrier base film, coating the raw materials of the first black matting layer on one surface of the carrier base film, drying at 130 °C for 5 min, and then coating the raw materials of the second black matting layer on the other opposite surface of the carrier base film, drying at 130 °C for 5 min. After curing at 55 °C for 48 h, the light-shielding composite film for the optical instrument is obtained. The process flow chart of the preparation of the light-shielding composite film for the optical instrument is as Figure 2 shown.

[0141] Test Method

[0142] In the present invention, various tests are carried out on the light-shielding composite films prepared under the above different preparation conditions to verify their performance in terms of optical density, glossiness, surface resistance, surface roughness, coating scratch resistance, coating adhesion, high temperature and high humidity reliability, etc.

[0143] For the above characteristics, the test methods are as follows:

[0144] 1. Optical Density

[0145] Optical density is a measure of the light absorption characteristic of an object, that is, the ratio of the incident light amount to the reflected light amount or the transmitted light amount, usually expressed as the decimal logarithm of the reciprocal of the transmittance or reflectance, and is an important parameter characterizing the light-shielding performance of the light-shielding composite film. The transmittance of the cured light-shielding composite film is tested by a Hitachi 4100 spectroscopic analyzer for calculation. The greater the optical density, the smaller the light transmittance, and the better the light-shielding property of the light-shielding composite film. Five points are tested and the average value is taken. If it is greater than 6, it is recorded as ○, if it is greater than 4 and less than 6, it is recorded as △, and if it is less than 4, it is recorded as ×.

[0146] 2. Glossiness

[0147] Glossiness is used to characterize the reflection degree of the surface of the matting coating of the light-shielding composite film to visible light, and is a parameter characterizing the matting effect of the light-shielding composite film. According to the GB / T9754-2007 standard, the surface glossiness of the light-shielding composite film when the incident angle of visible light is 60° is tested. The lower the glossiness, the better the matting property. Five points are tested and the average value is taken.

[0148] 3. Surface Resistance

[0149] Surface resistance is an important parameter for measuring the antistatic effect of the light-shielding composite film. According to the ASTM D-257 standard, during the test, just place two heavy hammers on the surface of the light-shielding composite film and press the test button, and the surface resistance value of the measured object will be displayed on the instrument. Take the average value after testing 5 points.

[0150] 4. Surface roughness

[0151] Surface roughness refers to the unevenness of the light-shielding composite film surface with relatively small spacing and tiny peaks and valleys. The distance (wavelength) between two wave peaks or two wave valleys is very small (less than 1 mm), and it belongs to the microscopic geometric shape error. The smaller the surface roughness, the smoother the surface. According to the GB / T131-2006 standard, after calibrating the test probe with a standard test piece before the test, place the probe on the surface of the light-shielding composite film to test the surface roughness Ra, and take the average value after testing 5 points.

[0152] 5. Scratch resistance

[0153] The surface scratch resistance of the light-shielding composite film is an important parameter for characterizing the reliability of the light-shielding composite film during die-cutting, assembly, and use of optical devices. According to the GB / T 9279-2015 standard, use a circular needle, at a speed of 5 mm / s and a load of 200 g. If no scratches are caused on the surface of the light-shielding composite film after 5 measurements, it is marked as ○, otherwise it is marked as ×.

[0154] 6. Contact angle

[0155] Poor hydrophobicity on the surface of the light-shielding composite film will cause the light-shielding composite film to stick together after die-cutting cleaning and after alkali liquor matting cleaning and drying, affecting the light-shielding effect and assembly operation efficiency of the light-shielding composite film. According to the GB / T 30693-2014 standard, test the water contact angle on the surface of the light-shielding composite film, and take the average value after testing 10 points. When the surface water contact angle of the light-shielding composite film is greater than 90°, the surface of the light-shielding composite film is a hydrophobic surface, marked as ○, otherwise marked as ×.

[0156] 7. Lubricity

[0157] In order to study the surface lubricity of the light-shielding composite film, test the dynamic friction coefficient (μd) and static friction coefficient (μs) of the light-shielding composite film surface according to the GB / T 10006-2021 standard. If both the dynamic friction coefficient (μd) and the static friction coefficient (μs) are less than 0.3, it is marked as ○, if greater than 0.3, it is marked as ×.

[0158] 8. Coating adhesion

[0159] According to the GB / T9286-2021 standard, the initial adhesion of the black matte layer of the light-shielding composite film was tested using the white grid knife method. To study the adhesion of the coating after alkali-resistant matte treatment of the light-shielding composite film, the adhesion of the coating after alkali solution matte treatment of the light-shielding composite film was also tested under the condition of soaking in 50% concentration of NaOH solution at 80 °C for 30 minutes. The edge of the incision of the white grid knife test on both sides of the light-shielding film is smooth and there is no peeling at the edge of the grid, which is marked as ○, otherwise it is marked as ×.

[0160] 9. High-temperature and high-humidity reliability test.

[0161] The light-shielding composite film was placed in a high-temperature and high-humidity chamber at a temperature of 85 °C and a relative humidity of 85% for 120 hours, and then taken out and placed at room temperature for 2 hours. If there are no defects such as peeling, white dots, and black dots on the surface of the light-shielding composite film, it is marked as ○, otherwise it is marked as ×.

[0162] Table 2 Performance test results of the light-shielding composite films of Examples 1-2 and Comparative Examples 1-3

[0163]

[0164] According to Examples 1-2, the light-shielding composite film of the present invention has good optical properties, coating adhesion and surface hydrophobicity, and at the same time improves the friction resistance, strong alkali resistance and high-temperature and high-humidity resistance of the light-shielding film.

[0165] According to Example 1 and Comparative Example 1, when the extinction coating does not contain polyacrylate polyol with good alkali resistance, wear resistance and weather resistance, the gloss of the obtained light-shielding composite film decreases significantly, and the scratch resistance and high-temperature and high-humidity resistance are also affected.

[0166] According to Example 1 and Comparative Examples 2-3, when the extinction coating does not contain polyester polyol with good adhesion, the wear resistance of the obtained light-shielding composite film becomes poor, and due to the lack of polytetrahydrofuran diol with better flexibility, the high-temperature and high-humidity resistance is poor.

[0167] According to Example 1 and Comparative Example 4, when the extinction coating does not contain organic matting agent, the elasticity and coating surface morphology of the obtained light-shielding composite film are affected, resulting in a poor matting effect. In particular, due to the mixed use of organic matting powder and inorganic matting powder, to a certain extent, the matting effect of the extinction coating is improved, and the obtained light-shielding composite film has better gloss.

[0168] The above has described the embodiments of the present invention in detail, but the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the purpose of the present invention. In addition, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

Claims

1. A matting coating, characterized in that, By weight parts, the raw materials for preparing the matting coating include the following components: 60 - 80 parts of polyacrylate polyol; 5 - 20 parts of polyester polyol; 5 - 20 parts of polyether polyol; Matting powder: 4 - 13 parts; the particle size of the matting powder is 2 - 10 microns; 6 - 18 parts of carbon black; 15 - 50 parts of curing agent; 0.55 - 1.5 parts of phosphor powder; 0.2 - 5 parts of auxiliary agent; The hydroxyl value content of the polyacrylate polyol is 2% - 4.5%; the hydroxyl value content of the polyester polyol is 1.6% - 3.5%; the hydroxyl value content of the polyether polyol is 1.8% - 3.6%; The matting powder includes organic matting powder and inorganic matting powder; the mass ratio of the organic matting powder to the inorganic matting powder is 1:1 - 3; the average molecular weight of the polyether polyol is 1000 - 2000.

2. The matting coating according to claim 1, wherein The curing agent is an aliphatic isocyanate curing agent.

3. The matting coating according to claim 1, wherein, The carbon black is at least one of high - pigment carbon black and conductive carbon black.

4. The matting coating according to claim 1, wherein The auxiliary agent includes at least one of a leveling agent and a dispersant.

5. A method for preparing the matting coating according to any one of claims 1 to 4, characterized in that, The preparation method includes: Mix the raw materials for preparing the matting coating in proportion, and carry out stirring and sanding treatment.

6. The preparation method of the matting coating according to claim 5, characterized in that, The time of the sanding treatment is 1 - 3 h.

7. A light-shielding film for an optical instrument, characterized in that, The light - shielding film for optical instruments includes a carrier base film, a first matting layer provided on one side of the carrier base film, and a second matting layer provided on the other side of the carrier base film; The raw materials for preparing the matting layer include the matting coating as described in any one of claims 1 - 4.

8. The light-shielding film for an optical instrument according to claim 7, characterized in that, The thickness of the matting layer is 2 - 20 microns.

9. The light-shielding film for an optical instrument according to claim 7, wherein The thickness of the carrier base film is 40 - 200 microns.

10. A method for preparing a light-shielding film for an optical instrument according to any one of claims 7 to 9, characterized in that, The preparation method includes: Coat the matting coating on one surface of the carrier base film, dry it to form a first matting layer; then coat the matting coating on the other opposite surface of the carrier base film, dry it to form a second matting layer, and after curing, the light - shielding film for optical instruments is obtained.

11. The method for preparing a light-shielding film for an optical instrument according to claim 10, wherein, The drying temperature is 60 - 160 °C.

12. The method for preparing a light-shielding film for an optical instrument according to claim 10, characterized in that, The drying time is 2 - 5 min.

13. The method for preparing a light-shielding film for an optical instrument according to claim 10, wherein The curing temperature is 20 - 65 °C.

14. The method for preparing a light-shielding film for an optical instrument according to claim 10, wherein The curing time is 20 - 60 h.

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