Bailian ultra-black nano-composite coating and contrast enhancement application thereof in LED (light-emitting diode) display screen

Abstract

The invention relates to the technical field of display screen coatings, in particular to a Bailian ultra-black nano-composite coating and application of the Bailian ultra-black nano-composite coating in contrast enhancement of an LED display screen. The invention relates to a Bailian ultra-black nano composite material, which is prepared from the following ingredients in parts by weight: 200 parts of carbon nano tubes, 100 to 200 parts of graphene, 40 to 80 parts of antistatic materials, 20 to 40 parts of ferromanganese black, 400 to 600 parts of resin and 3000 to 4000 parts of ethyl acetate. The anti-static material comprises at least one of titanium black and chromium dioxide; the resin comprises at least one of epoxy resin, polyurethane resin and acrylic resin. On one hand, the corrosion resistance of the coating is enhanced through the ferromanganese black, and generation of pits in the surface of the coating is reduced; on the other hand, the antistatic material is added to improve a three-dimensional conductive network formed by the carbon nanotubes and the graphene, so that the aggregation degree of charges is reduced, and the adsorption probability of dust is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display screen coating, in particular to a Belyan super black nanocomposite coating and its application in contrast enhancement of LED display screens. BACKGROUND

[0002] The Belyan super black nanocomposite coating is a new type of material capable of efficiently absorbing incident light. The super black property of the coating is derived from the nanoscale structure design (such as carbon nanotube array or porous honeycomb structure), which can realize multiple scattering and absorption of incident light, and has extremely high light absorption rate. It has wide application prospects in scientific research and engineering application fields. The Belyan super black nanocomposite coating also has applications in LED display screens.

[0003] However, the components of the Belyan super black nanocomposite coating vary, and some Belyan super black nanocomposite coatings have poor corrosion resistance, which causes many pits on the surface of the coating after long-term use. These pits provide a foothold for dust in the environment, which in turn affects the image display effect of various display screens. For example, LED display screens have high resolution and fine picture quality, and dust on the surface will seriously affect their use. SUMMARY

[0004] To solve the problem of poor corrosion resistance of some Belyan super black nanocomposite coatings, which causes dust to fall on the surface of the display screen, the present application provides a Belyan super black nanocomposite material. On the one hand, the present application enhances the corrosion resistance of the coating by using manganese-iron black to reduce the generation of pits on the surface of the coating. On the other hand, the present application improves the three-dimensional conductive network composed of carbon nanotubes and graphene by adding an antistatic material to reduce the degree of charge accumulation and the probability of dust adsorption.

[0005] In a first aspect, the present application provides a Belyan super black nanocomposite material, which adopts the following technical solution: A Belyan super black nanocomposite material includes the following components by weight: Carbon nanotubes 200 parts, graphene 100-200 parts, antistatic material 40-80 parts, manganese-iron black 20-40 parts, resin 400-600 parts, ethyl acetate 3000-4000 parts; The antistatic material includes at least one of titanium suboxide and chromium dioxide; The resin includes at least one of epoxy resin, polyurethane resin, and acrylic resin.

[0006] By adopting the technical scheme, the manganese-iron black is composed of iron-manganese oxide (Fe-Mn-O), the crystal structure of which remains stable in high temperature (heat resistance up to 600 DEG C or above) and acid-alkali environment, effectively preventing the penetration and reaction of corrosion medium. As an inorganic pigment, the manganese-iron black has fine particle size and uniform dispersion, can fill the micropores in the coating, and reduce the penetration rate of water, oxygen and corrosive ions (Cl - , SO4 2- ). The addition of the manganese-iron black improves the corrosion resistance of the coating, thereby reducing the pits caused by environmental corrosion and reducing the probability of dust falling.

[0007] In the antistatic material, the titanium suboxide can form a continuous conductive network in the coating, accelerate charge migration, and avoid static accumulation. The uniform dispersion of titanium suboxide particles enhances the electron transport efficiency inside the coating, especially in the thermal spraying process, which is closely combined with the resin matrix to form a low-resistance path, significantly reducing the surface resistivity. Chromium dioxide itself has certain semiconductor properties, and the defects and doping in its crystal structure can form a carrier channel to promote electron migration. The dispersed chromium dioxide particles in the coating form a conductive path by mutual contact, reducing the overall resistance of the coating, thereby accelerating the dissipation of static charges. The three-dimensional conductive network can be formed between carbon nanotubes and graphene, and the addition of the antistatic material can further improve the conductive performance and reduce the degree of charge accumulation on the surface of the coating, thereby reducing the probability of dust adsorption.

[0008] The present application enhances the corrosion resistance of the coating by manganese-iron black, and reduces the generation of pits on the surface of the coating. On the other hand, the three-dimensional conductive network composed of carbon nanotubes and graphene is improved by adding antistatic material, reducing the degree of charge accumulation and the probability of dust adsorption.

[0009] Preferably, the antistatic material is titanium suboxide.

[0010] By adopting the technical scheme, the titanium suboxide not only improves the conductive performance of the coating, but also remains chemically inert in strong acid, strong alkali and corrosive medium containing fluoride ions, avoiding the erosion of the coating itself. Therefore, the titanium suboxide particles can fill the micropores of the coating and reduce the penetration path of corrosive medium (such as Cl - , H2O).

[0011] Preferably, the antistatic material is a mixture of titanium suboxide and chromium dioxide.

[0012] By adopting the technical scheme, the chromium dioxide surface may have oxygen vacancies or specific charge distribution, which can interact with the carbon nanotubes / graphene through electrostatic adsorption or van der Waals force, affect the arrangement direction, and thus improve the overall conductive network. After the carbon nanotubes / graphene are directionally arranged and combined with the titanium suboxide particles, the high conductivity of the titanium suboxide enables the conductive network to have high electron mobility and low interface resistance.

[0013] In addition, the chromium dioxide is a ferromagnetic substance, and can be induced by an external magnetic field to make the carbon nanotubes or graphene have better directional arrangement effect. Therefore, the titanium suboxide and the chromium dioxide have good synergistic effect, which can further improve the conductive network and improve the antistatic ability of the coating.

[0014] Preferably, the mass ratio of the titanium suboxide and the chromium dioxide in the mixture is 10:3-5.

[0015] By adopting the technical scheme, when the content of the chromium dioxide is too low, the synergistic effect of the titanium suboxide and the chromium dioxide is not good, and the antistatic performance is limitedly improved; when the content of the chromium dioxide is too high, the proportion of the titanium suboxide is low, which also reduces the synergistic effect of the two and the corrosion resistance of the coating; therefore, the applicant finally determines that the mass ratio of the titanium suboxide and the chromium dioxide in the present application is appropriate.

[0016] Preferably, the resin is an epoxy resin.

[0017] By adopting the technical scheme, among the three resins, the manganese iron black, the titanium suboxide, and the chromium dioxide have stronger bonding force with the epoxy resin, and relatively, the coating has higher corrosion resistance and antistatic performance.

[0018] In a second aspect, the present application provides a preparation method of the Beilian super-black nanocomposite, which adopts the following technical scheme: The preparation method of the Beilian super-black nanocomposite is used for preparing the above-mentioned Beilian super-black nanocomposite, and includes the following steps: Step one: mix the formula amount of carbon nanotubes and graphene to obtain a mixture A; Step two: mix the mixture A, the antistatic material, and the manganese iron black into the resin, then mix the ethyl acetate, and uniformly stir to obtain the Beilian super-black nanocomposite.

[0019] In a third aspect, the present application provides an application of the Beilian super-black nanocomposite, which adopts the following technical scheme: The application of the Beilian super-black nanocomposite includes the following steps: spraying the Beilian super-black nanocomposite to the surface of a substrate, and curing to obtain a Beilian super-black nanocomposite coating.

[0020] Preferably, when the anti-static material in the Belian super black nanocomposite material includes chromium dioxide, the Belian super black nanocomposite material is sprayed to the surface of the substrate under the condition of a magnetic field, and after solidification, the Belian super black nanocomposite coating is obtained.

[0021] By adopting the technical scheme, the chromium dioxide is a ferromagnetic substance, and the chromium dioxide can be induced by an external magnetic field, so that the directional arrangement effect of the carbon nanotubes or graphene is better, and the conductive network can be further improved, and the anti-static ability of the coating is improved.

[0022] In summary, the application has the following beneficial effects: 1. On the one hand, the manganese iron black is used to enhance the corrosion resistance of the coating and reduce the generation of pits on the surface of the coating; on the other hand, the anti-static material is added to improve the three-dimensional conductive network composed of carbon nanotubes and graphene, reduce the degree of charge accumulation, and reduce the adsorption probability of dust; 2. The anti-static material of the application is a mixture of titanium suboxide and chromium dioxide, which can exert the synergistic effect of titanium suboxide and chromium dioxide, thereby further improving the anti-static ability of the coating; in particular, the chromium dioxide is induced by an external magnetic field when the coating is applied, so that the directional arrangement effect of the carbon nanotubes or graphene is better. DETAILED DESCRIPTION

[0023] In the application, the raw materials include the following parts: Chromium dioxide: a commercially available product with CAS number 12018-01-8 is used; Titanium suboxide: a commercially available product with CAS number 12065-65-5 is used; Manganese iron black: a commercially available product with CAS number 68186-94-7 is used; The application will be further described in detail in combination with examples and comparative examples.

[0024] Example 1 A preparation method of a Belian super black nanocomposite material includes the following steps: Step one: 200g of carbon nanotubes and 200g of graphene are mixed to obtain a mixture A; Step two: the mixture A, 80g of titanium suboxide, and 40g of manganese iron black are added to 600g of epoxy resin for mixing, and then 4000g of ethyl acetate is added for mixing, and after ultrasonic stirring, a Belian super black nanocomposite material is obtained.

[0025] An application of the Beilian super black nanocomposite, comprising the following steps: spraying the Beilian super black nanocomposite to a glass surface, the spraying angle being 75° (70-80° are all acceptable), adopting a ladder curing process, specifically, 2h at 80℃, then 1h at 120℃, and finally 12h at 60℃, and the Beilian super black nanocomposite coating is obtained.

[0026] The base material can be a display screen such as an LED display screen, a metal material, etc. in addition to glass. The present application is only exemplified by glass.

[0027] Example 2-3 Example 2-3 is based on the preparation method of Example 1, and the content of each component of the Beilian super black nanocomposite is adjusted, and the specific adjustment is shown in Table 1.

[0028] Comparative Example 1-2 Comparative Example 1 is based on the preparation method of Example 1, and no manganese black is added.

[0029] Comparative Example 2 is based on the preparation method of Example 1, and no titanium suboxide is added.

[0030] The Beilian super black nanocomposite coatings of Examples 1-3 and Comparative Example 1-2 are subjected to the following performance detection tests.

[0031] Performance detection test 1. Corrosion resistance According to GB / T 17897 2016, the corrosion rate is determined.

[0032] 2. Anti-static performance First, the Beilian super black nanocomposite coating is placed in a 35℃ salt spray environment for 12h, and the salt spray concentration is 5% sodium chloride solution. Then, it is placed in a room temperature environment for 5 days, and the number of dust points per square centimeter on the Beilian super black nanocomposite coating is counted.

[0033] Table 1: Component content (unit: g) and performance detection table of Examples 1-3 and Comparative Example 1-2 As shown in Table 1, it can be seen from Comparative Examples 1-3 and Comparative Example 1-2 that if the Beilian super black nanocomposite coating does not contain manganese black, the corrosion resistance of the coating decreases. This may be because manganese black, as an inorganic pigment, has a small particle size and is uniformly dispersed, which can fill the micropores in the coating and reduce the penetration rate of water, oxygen and corrosive ions (Cl - , SO4 2- ). The addition of manganese black improves the corrosion resistance of the coating, thereby reducing the pits caused by environmental corrosion, and also reducing the number of dust points.

[0034] If the sub-titanium oxide is not contained in the Belian super black nano composite coating, the corrosion resistance of the coating will decrease to a certain extent, and the anti-static performance will decrease more. The reason may be that the sub-titanium oxide can form a continuous conductive network in the coating, accelerate the migration of electric charge, and avoid the accumulation of static electricity. The sub-titanium oxide not only can improve the conductivity of the coating, but also has stable crystal structure, and remains chemically inert in strong acid, strong alkali and fluoride ion containing corrosive medium, avoiding the corrosion of the coating itself. Therefore, the sub-titanium oxide particles can fill the pores of the coating, reduce the penetration path of the corrosive medium (such as Cl - , H2O).

[0035] In addition, it is found that the comprehensive performance of example 1 is the best among comparative examples 1-3, so example 1 is preferred.

[0036] Examples 4-7 Example 4 is based on the preparation method of example 1, and 80g of sub-titanium oxide is replaced by 80g of chromium dioxide.

[0037] Example 5 is based on the preparation method of example 1, and 80g of sub-titanium oxide is replaced by 80g of a mixture of sub-titanium oxide and chromium dioxide, and the mass ratio of sub-titanium oxide to chromium dioxide in the mixture is 10:4.

[0038] Examples 6-7 are based on the preparation method of example 5, and the mass ratio of sub-titanium oxide to chromium dioxide is adjusted, and the specific adjustment is shown in table 2.

[0039] The Belian super black nano composite coating of examples 4-7 is subjected to the performance test as above, and the test results are shown in table 2.

[0040] Table 2: anti-static material types and mass ratio of sub-titanium oxide to chromium dioxide and performance test data of examples 1 and examples 4-7 As shown in table 2, comparative examples 1 and examples 4-7, the corrosion resistance of chromium dioxide is not as good as that of sub-titanium oxide, but the surface of chromium dioxide may have oxygen vacancies or specific charge distribution, which can interact with carbon nanotubes / graphene through electrostatic adsorption or van der waals force, affect the arrangement direction, and improve the overall conductive network, so that the anti-static performance of the coating containing chromium dioxide is better.

[0041] When chromium dioxide and sub-titanium oxide are compounded, chromium dioxide promotes the directional arrangement of carbon nanotubes / graphene, and the high conductivity of sub-titanium oxide makes the conductive network have high electron mobility and low interface resistance.

[0042] With the proportion of chromium dioxide in the mixture gradually increasing, the antistatic performance of the coating shows a trend of first rising and then falling, because with the proportion of chromium dioxide in the mixture gradually increasing, the synergistic effect of titanium suboxide and chromium dioxide gradually increases, thereby gradually improving the antistatic performance of the coating. When exceeding a certain range, the proportion of titanium suboxide is low, which will also reduce the synergistic effect of the two, and also reduce the corrosion resistance of the coating.

[0043] Examples 8-9 Examples 8-9 are based on the preparation method of Example 1, and the types of resins are adjusted, and the specific adjustments are shown in Table 3.

[0044] The performance of the Belian super black nano composite coating of Examples 8-9 is detected as above, and the test results are shown in Table 3.

[0045] Table 3 Resin types and performance test data of Example 1 and Examples 8-9 As shown in Table 3, comparing Example 1 and Examples 8-9, among the three resins, the coating prepared by the epoxy resin has higher corrosion resistance and antistatic performance. It may be due to the stronger bonding force of manganese black, titanium suboxide and chromium dioxide and the epoxy resin.

[0046] Examples 10-12 Example 10 is modified from Example 1, and the Belian super black nano composite material is sprayed onto the surface of the glass under the condition of a magnetic field strength of 1.5T (0.5T-1.5T can be used), a spraying angle of 75° (70-80° can be used), and a ladder curing process, which is 80°C for 2h, then 120°C for 1h, and finally 60°C for 12h, to obtain the Belian super black nano composite coating.

[0047] Example 11 is based on the preparation method of Example 10, and 80g of titanium suboxide is replaced by 80g of chromium dioxide.

[0048] Example 12 is based on the preparation method of Example 10, and 80g of titanium suboxide is replaced by a mixture of 80g of titanium suboxide and 80g of chromium dioxide, and the mass ratio of titanium suboxide to chromium dioxide in the mixture is 10:4.

[0049] The performance of the Belian super black nano composite coating of Examples 10-12 is detected as above, and the test results are shown in Table 4.

[0050] Table 4 Antistatic material types and whether to spray under a magnetic field of Example 1 and Examples 10-12 and performance test data table As shown in Table 4, comparative example 1 and examples 10-12 show that titanium suboxide is not a magnetic material, and the magnetic field has little effect on titanium suboxide. Chromium dioxide is a magnetic material, and the external magnetic field induces chromium dioxide, which makes the directional arrangement of carbon nanotubes or graphene better, and has a better conductive network, thereby improving the anti-static performance of the coating.

[0051] When titanium suboxide and chromium dioxide are compounded, and an external magnetic field is applied, the synergistic effect of the two can be further promoted, and the conductive performance is further improved, thereby improving the anti-static performance of the coating.

[0052] Application example The application example can use any one of the examples 1-12 of the super black nanocomposite coating.

[0053] Application example 1 An application of a super black nanocomposite material includes the following steps: spraying the super black nanocomposite material of example 1 to the surface of an LED display screen, and using a step curing process, specifically 2h at 80℃, then 1h at 120℃, and finally 12h at 60℃, and the super black nanocomposite coating is obtained.

[0054] The LED display screen with the super black nanocomposite coating has an optical performance of a light transmittance ≥99.3% in the 380-780nm wavelength band and a black field reflectance ≤0.6%. The protective performance is a pencil hardness ≥3H (ASTM D3363 standard test). The impact resistance performance is an impact resistance energy ≥90 in·lb (ASTM D2794 standard test).

[0055] The LED display screen without the super black nanocomposite coating and the LED display screen with the super black nanocomposite coating are tested by the VESA standard, and it is found that the display screen contrast ratio of the LED display screen without the super black nanocomposite coating is 1500:1, and the display screen contrast ratio of the LED display screen with the super black nanocomposite coating is 5000:1. The reason for the increase in the display screen contrast ratio of the LED display screen with the super black nanocomposite coating is that the coating surface roughness Ra≤0.05μm, which enhances the black field depth by reducing diffuse reflection, and the three-dimensional network structure of carbon nanotubes / graphene reduces light scattering.

[0056] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contributions after reading the present specification, and the modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A Beilian ultra-black nanocomposite material, characterized in that: The composition comprises the following components in parts by weight: 200 parts of carbon nanotubes, 100-200 parts of graphene, 40-80 parts of antistatic material, 20-40 parts of manganese iron black, 400-600 parts of resin, and 3000-4000 parts of ethyl acetate; The antistatic material includes at least one of titanium dioxide and chromium dioxide; The resin includes at least one of epoxy resin, polyurethane resin and acrylic resin.

2. The Beilian ultra-black nanocomposite material according to claim 1, characterized in that: The antistatic material is titanium dioxide.

3. The Beilian ultra-black nanocomposite material according to claim 1, characterized in that: The antistatic material is a mixture of titanium dioxide and chromium dioxide.

4. The Beilian ultra-black nanocomposite material according to claim 3, characterized in that: The mass ratio of titanium dioxide to chromium dioxide in the mixture is 10:3-5.

5. The Beilian ultra-black nanocomposite material according to claim 1, characterized in that: The resin is epoxy resin.

6. The method for preparing the Beilian ultra-black nanocomposite material according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Mixing the carbon nanotubes and graphene in a prescribed amount to obtain a mixture A; Step 2: Add mixture A, antistatic material and manganese iron black into the resin and mix them, then add ethyl acetate and mix them, and then ultrasonically stir them to obtain the Belian ultra-black nano-composite material.

7. An application of the Beilian ultra-black nanocomposite material according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: spraying the Beilian ultra-black nano-composite material onto the surface of a substrate, and forming the Beilian ultra-black nano-composite coating after curing.

8. The use of the Beilian ultra-black nanocomposite material according to claim 7, characterized in that: The following steps are involved: When the antistatic material in the Beilian ultra-black nanocomposite material includes chromium dioxide, the Beilian ultra-black nanocomposite material is sprayed onto the surface of the substrate under magnetic field conditions, and after curing, it becomes the Beilian ultra-black nanocomposite coating.

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