Printing ink for LED (light-emitting diode) mask, preparation method of printing ink and preparation method of LED mask

Abstract

The invention relates to the technical field of display devices, in particular to ink for an LED mask, a preparation method of the ink and a preparation method of the LED mask. The ink for the LED mask comprises the following components in percentage by mass: 35%-50% of matrix resin, 25%-40% of a diluent, 15%-25% of a coloring agent, 2%-4% of an accelerant, 2%-4% of an anti-settling agent, 0.1%-1.2% of a weather-proof agent, 0.5%-1% of a dispersing agent, 0.4%-0.6% of a defoaming agent and 0.4%-0.6% of a flatting agent, wherein the coloring agent comprises pigment carbon black of which the blackness is less than or equal to 20; the weather-resistant agent comprises an ultraviolet absorbent and a free radical trapping agent in a mass ratio of (1-3): (1-3). According to the ink for the LED mask, the contrast ratio of the LED mask is improved, meanwhile, the ink color consistency and weather resistance of the LED mask are effectively improved, and therefore the color developing effect of an LED display screen is optimized, and the service life of the LED display screen is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and in particular to an ink for an LED mask and a preparation method thereof, and a preparation method of an LED mask. Background Art

[0002] Light Emitting Diode (LED) is a semiconductor electronic component that converts electrical energy into light energy. It has the advantages of energy saving, high efficiency, rich colors, fast response speed and long service life. It is increasingly widely used in display screens. Contrast is an important indicator to measure the performance of LED display screens, and has a very critical impact on display effects and visual effects. Generally speaking, the greater the contrast, the clearer and more eye-catching the image, and the brighter the color; while a smaller contrast will make the entire display screen composed of LEDs appear gray, seriously affecting the viewing effect.

[0003] LED mask is a component installed on the surface of LED display module, which can prevent glare, improve contrast, improve color uniformity and physical protection. At present, the method of improving the contrast of LED display is mainly to use ink to spray on the surface of LED mask to form a high-contrast paint film. However, traditional ink has the defects of poor ink color consistency and insufficient weather resistance, which affects the display effect of LED display. Summary of the invention

[0004] Based on this, it is necessary to provide an ink for an LED mask and a preparation method thereof and a preparation method of an LED mask to solve the problem that traditional inks have the defects of poor ink color consistency and insufficient weather resistance, which affects the display effect of the LED display.

[0005] The above-mentioned purpose of the present application is achieved through the following technical solutions:

[0006] In a first aspect of the present application, an ink for an LED mask is provided, comprising the following components by mass fraction:

[0007] ;

[0008] Wherein, the colorant comprises carbon black pigment with a blackness of ≤30;

[0009] The weathering agent comprises an ultraviolet absorber and a free radical scavenger in a mass ratio of (1-3): (1-3).

[0010] In some embodiments, the particle size of the pigment carbon black is 10 nm to 25 nm, and the DBP oil absorption value of the pigment carbon black is 80 mL / 100 g to 120 mL / 100 g.

[0011] In some embodiments, the ultraviolet absorber includes one or more of a benzotriazole ultraviolet absorber and a triazine ultraviolet absorber, and the free radical scavenger includes a hindered amine free radical scavenger.

[0012] In some embodiments, the base resin includes one or more of an acrylate resin, a polyurethane resin, and an epoxy resin.

[0013] In some embodiments, the diluent includes one or more of n-butyl acetate, ethyl acetate, and ethylene glycol monobutyl ether.

[0014] In some embodiments, the mass ratio of the n-butyl acetate, the ethyl acetate and the ethylene glycol monobutyl ether is (1-3):1:(1-2).

[0015] In some embodiments, the promoter includes one or more of an organometallic ester compound and a phosphate ester compound.

[0016] In some embodiments, the anti-settling agent includes one or more of polyamide compounds, modified bentonite, fumed silica, and hydroxyethyl cellulose.

[0017] In some embodiments, the dispersant includes one or more of an organosiloxane polymer, a modified polyester, an acetylene alcohol compound, and a polyolefin wax.

[0018] In some embodiments, the defoaming agent includes one or more of a silicone defoaming agent, a polyether-modified defoaming agent, and a mineral oil defoaming agent.

[0019] In some embodiments, the leveling agent includes one or more of a polyether-modified leveling agent, an organosilicon-based leveling agent, and a non-organosilicon-based leveling agent.

[0020] In some embodiments, the ink for LED mask includes the following components by mass fraction:

[0021] .

[0022] In a second aspect of the present application, a method for preparing ink for an LED mask is provided, comprising the following steps:

[0023] Prepare the components for the LED mask ink as described above;

[0024] Mixing the base resin, part of the diluent, the dispersant, the accelerator and the leveling agent uniformly to obtain a mixed solution A;

[0025] The mixed solution A, the weathering agent, the anti-settling agent and the colorant are mixed evenly to obtain a mixed solution B;

[0026] The mixed solution B, the remaining diluent and the defoaming agent are mixed evenly to obtain a mixed solution C;

[0027] The mixed solution C is ground and filtered to obtain the LED mask ink.

[0028] In a third aspect of the present application, a method for preparing an LED mask is provided, comprising the following steps:

[0029] Mixing the ink for LED mask as described above with an organic solvent to obtain a diluted ink;

[0030] The semi-finished mask is sprayed with the diluted ink, and dried at 60° C. to 70° C. for 10 min to 15 min to obtain an LED mask.

[0031] This application has at least the following beneficial effects:

[0032] In the ink for LED masks provided by the present application, a pigment carbon black with a blackness of ≤30 is added as a colorant to improve the overall blackness of the ink, thereby improving the blackness of the LED mask and further improving the contrast of the LED display. Adding a specific ratio of ultraviolet absorbers and free radical scavengers as weathering agents effectively inhibits and slows down the rate of degradation and aging of the ink under the action of light radiation, improves the aging resistance of the ink, and enables the LED mask to maintain a high contrast after long-term outdoor use, thereby greatly extending the service life of the product. Adding an appropriate amount of diluent, promoter, anti-settling agent, dispersant, defoamer and leveling agent can adjust the physical and chemical properties of the ink, such as concentration, viscosity, thixotropy and adhesion, improve the uniformity of the dispersion of each component, avoid the aggregation and sedimentation of the colorant, and make the ink have good ink color consistency. Therefore, the ink for LED masks provided by the present application effectively improves the ink color consistency and weather resistance of the LED mask while improving the contrast of the LED mask, thereby optimizing the color rendering effect and service life of the LED display. DETAILED DESCRIPTION

[0033] In order to facilitate the understanding of the present application, the present application is further described in detail below in conjunction with specific embodiments. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0035] In the present application, the meaning of "and / or" includes any and all combinations of one or more related listed items. "At least one" means more than one, such as one, two and more than two. "Multiple" or "several" means at least two, such as two, three, etc., and "multi-layer" means at least two layers, such as two layers, three layers, etc., unless otherwise clearly and specifically defined. In the description of the present application, "several" means at least one, such as one, two, etc., unless otherwise clearly and specifically defined.

[0036] When a numerical range is disclosed in this application, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed in this application should be understood to include any and all subranges included therein.

[0037] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0038] In this application, "above" or "below" includes the number itself. For example, "1 below" includes 1.

[0039] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0040] In the present application, room temperature refers to indoor temperature, normal temperature or general temperature. Generally speaking, the range of room temperature can be any one of the following temperature intervals: 23°C ± 2°C, 25°C ± 5°C or 20°C ± 5°C.

[0041] The method to improve the contrast of LED display screens is mainly to use ink to spray on the surface of LED masks to form a high-contrast paint film. At present, most of the mask inks on the market are general standard ink products. There is a lack of ink products dedicated to LED masks, which has limitations when used. Most ink formulas are composed of various polymer materials. If there are differences in the formula design, or the raw materials are not properly controlled, or the ingredients are different in batches, or affected by factors such as the spraying process, ambient temperature and humidity, the ink is prone to inconsistent ink color after being sprayed on the mask, which ultimately leads to a mosaic effect on the LED display. At the same time, LED masks are used outdoors for a long time. Due to poor weather resistance, the paint film is easy to fade, resulting in a decrease in contrast, thereby affecting the display effect of the display module.

[0042] Based on this, the present application provides an ink for LED masks, which is used to solve the problem that traditional inks have poor ink color consistency and insufficient weather resistance, affecting the display effect of LED display screens.

[0043] In some embodiments, the ink for LED mask includes the following components by weight:

[0044] ;

[0045] Wherein, the colorant includes carbon black pigment with a blackness of ≤30;

[0046] The weathering agent includes an ultraviolet absorber and a free radical scavenger in a mass ratio of (1-3): (1-3).

[0047] In the ink for LED masks provided by the present application, a pigment carbon black with a blackness of ≤30 is added as a colorant to improve the overall blackness of the ink, thereby improving the blackness of the LED mask and further improving the contrast of the LED display. Adding a specific ratio of ultraviolet absorbers and free radical scavengers as weathering agents effectively inhibits and slows down the rate of degradation and aging of the ink under the action of light radiation, improves the aging resistance of the ink, and enables the LED mask to maintain a high contrast after long-term outdoor use, thereby greatly extending the service life of the product. Adding an appropriate amount of diluent, promoter, anti-settling agent, dispersant, defoamer and leveling agent can adjust the physical and chemical properties of the ink, such as concentration, viscosity, thixotropy and adhesion, improve the uniformity of the dispersion of each component, avoid the aggregation and sedimentation of the colorant, and make the ink have good ink color consistency. Therefore, the ink for LED masks provided by the present application effectively improves the ink color consistency and weather resistance of the LED mask while improving the contrast of the LED mask, thereby optimizing the color rendering effect and service life of the LED display.

[0048] In addition, the ink for LED masks provided in the present application also has the advantages of stable formula, stable performance and simple usage, which is beneficial to reducing the preparation cost of LED masks and has good economic benefits.

[0049] As an example, the mass fraction of the matrix resin includes but is not limited to 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49% or 50%, and can be further optionally 39% to 45%.

[0050] As an example, the mass fraction of the diluent includes but is not limited to 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39% or 40%, and can be further optionally 30% to 35%.

[0051] As an example, the mass fraction of the colorant includes but is not limited to 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24% or 25%, and can be further optionally 15% to 20%.

[0052] As an example, the mass fraction of the accelerator includes but is not limited to 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3%, 3.2%, 3.4%, 3.6%, 3.8% or 4%, and can be further optionally 2.5% to 3.5%.

[0053] As an example, the mass fraction of the anti-settling agent includes but is not limited to 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3%, 3.2%, 3.4%, 3.6%, 3.8% or 4%, and can be further optionally 2.5% to 3.5%.

[0054] As an example, the mass fraction of the weathering agent includes but is not limited to 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1% or 1.2%, and can be further optionally 0.4% to 1.2%.

[0055] As an example, the mass fraction of the dispersant includes, but is not limited to, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95% or 1%, and can further be 0.5% to 0.7%.

[0056] As an example, the mass fraction of the defoaming agent includes but is not limited to 0.4%, 0.42%, 0.44%, 0.46%, 0.48%, 0.5%, 0.52%, 0.54%, 0.56%, 0.58% or 0.6%, and can be further optionally 0.45% to 0.55%.

[0057] As an example, the mass fraction of the leveling agent includes but is not limited to 0.4%, 0.42%, 0.44%, 0.46%, 0.48%, 0.5%, 0.52%, 0.54%, 0.56%, 0.58% or 0.6%, and can be further optionally 0.45% to 0.55%.

[0058] In some embodiments, the ink for LED mask includes the following components by weight:

[0059] .

[0060] Understandably, pigment carbon black is a type of carbon black, and its tinting strength (or blackness), hue purity, dispersion performance, UV resistance, and acid and alkali resistance are significantly better than ordinary carbon black, which can give the ink a higher contrast and better ink color consistency. Generally, the blackness of pigment carbon black is related to its particle size. The smaller the particle size, the larger the specific surface area, the stronger the absorption and scattering of light, the higher the blackness, and the stronger the tinting power. According to GB / T 7044-2013 Pigment Carbon Black, pigment carbon black can be divided into six types: high pigment contact carbon black (HCC), high pigment furnace carbon black (HCF), medium pigment contact carbon black (MCC), medium pigment furnace carbon black (MCF), normal pigment contact carbon black (RCC) and normal pigment furnace carbon black (RCF); among them, the blackness of HCC and HCF is ≤22, and the particle size is 9nm~17nm; the blackness of MCC and MCF is 23~30, and the particle size is 18nm~25nm; the blackness of RCC and RCF is ≥31, and the particle size is 26nm~37nm. This application uses pigment carbon black with a blackness of ≤30 as a colorant, which has extremely strong tinting power and hiding power, and can effectively improve the blackness and contrast of the ink.

[0061] In some embodiments, the particle size of the pigment carbon black is 10 nm to 25 nm, including but not limited to 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm or 25 nm.

[0062] In some embodiments, the DBP oil absorption value of the pigment carbon black is 80 mL / 100 g to 120 mL / 100 g, including but not limited to 80 mL / 100 g, 85 mL / 100 g, 90 mL / 100 g, 95 mL / 100 g, 100 mL / 100 g, 105 mL / 100 g, 110 mL / 100 g, 115 mL / 100 g or 120 mL / 100 g. The DBP oil absorption value refers to the number of milliliters of dibutyl phthalate (DBP) absorbed by each 100 g of pigment carbon black.

[0063] In some embodiments, the pigment carbon black is selected from one or more of Cabot BP1400 pigment carbon black, Cabot BP1300 pigment carbon black, Cabot BP1000 pigment carbon black, Cabot BP880 pigment carbon black and Cabot BP700 pigment carbon black. Further optionally, the pigment carbon black is Cabot BP880 pigment carbon black, which has the advantages of strong hiding power, easy dispersion, high gloss and good stability.

[0064] It can be understood that the weathering agent in this application is also called a light stabilizer, which is a type of auxiliary agent that can inhibit or slow down the degradation and aging of polymer materials under the action of light (mainly ultraviolet rays), and usually includes one or more of ultraviolet absorbers, free radical scavengers and quenchers. Among them, ultraviolet absorbers are a type of auxiliary agent that can absorb ultraviolet rays to protect materials from ultraviolet damage. Common ones include benzophenones, benzotriazoles and triazines. Free radical scavengers are a type of substance that can effectively capture and terminate free radical chain reactions, and play an important role in preventing material aging and degradation. Common ones include hindered amine compounds such as piperidine derivatives and imidazoline derivatives, as well as phenolic compounds such as butylated hydroxyanisole (BHA) and dibutylhydroxytoluene (BHT). Quenchers are a type of substance that can return excited molecules to the ground state by energy transfer or charge transfer, thereby reducing the probability of photochemical reactions. Common ones include metal ion quenchers and aromatic quenchers. The present application utilizes ultraviolet absorbers and free radical scavengers in a specific ratio for synergistic combination, which can effectively improve the aging resistance of ink and extend the service life of the LED mask.

[0065] As an example, the mass ratio of the ultraviolet absorber to the free radical scavenger is (1-3):(1-3), including but not limited to 1:1, 2:1, 3:1, 1:2, 3:2, 1:3 or 2:3.

[0066] In some embodiments, the ultraviolet absorber includes one or more of a benzotriazole ultraviolet absorber and a triazine ultraviolet absorber, and the free radical scavenger includes a hindered amine free radical scavenger. Among them, the benzotriazole ultraviolet absorber includes one or more of UV-P, UV-234, UV-326, UV-327, UV-328, UV-350 and UV-571; the hindered amine free radical scavenger includes UV-622.

[0067] In some embodiments, the matrix resin includes one or more of acrylate resin, polyurethane resin and epoxy resin, and may further be acrylate resin.

[0068] In some embodiments, the diluent includes one or more of n-butyl acetate, ethyl acetate, and ethylene glycol monobutyl ether.

[0069] N-butyl acetate, ethyl acetate and ethylene glycol monobutyl ether all have good solubility, and can dissolve the base resin and various functional additives in the ink, reduce the concentration and viscosity of the ink, and make the ink easier to apply. It can be understood that the diluent can be any one of n-butyl acetate, ethyl acetate and ethylene glycol monobutyl ether, or a combination of at least two of them.

[0070] In some embodiments, the mass ratio of n-butyl acetate, ethyl acetate and ethylene glycol monobutyl ether is (1-3):1:(1-2). As an example, the mass ratio of n-butyl acetate to ethyl acetate includes but is not limited to 1:1, 1.5:1, 2:1, 2.5:1 or 3:1, and the mass ratio of ethyl acetate to ethylene glycol monobutyl ether includes but is not limited to 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8 or 1:2.

[0071] The volatilization speeds of n-butyl acetate, ethyl acetate and ethylene glycol monobutyl ether are different. By rationally adjusting the mass ratio of the three diluents, the drying speed of the ink can be accurately adjusted and the drying speed of the ink can be matched with the construction process, thereby improving the quality of the paint film.

[0072] In some embodiments, the promoter includes one or more of an organic metal ester compound and a phosphate compound; wherein the organic metal ester chelate includes one or more of a titanate compound, an aluminate compound, and a zirconate compound. The organic metal ester compound or the phosphate compound is selected as the promoter, which can activate components such as colorants through coupling or bridging, improve their dispersion uniformity in the ink, and help improve the physical and chemical properties of the ink such as water resistance and solvent resistance; at the same time, it can also serve as an adhesion promoter, improve the bonding performance between the components and the bonding performance of the ink on the LED mask, and prevent the cracking, peeling or shedding of the paint film.

[0073] In some embodiments, the anti-settling agent includes one or more of polyamide compounds, modified bentonite, fumed silica and hydroxyethyl cellulose. Adding an appropriate amount of the anti-settling agent can form a three-dimensional gel network structure with the matrix resin through hydrogen bonding, so that the ink has strong thixotropy, can support, fix or block fixed particles such as colorants, effectively prevent the aggregation and sedimentation of colorants, thereby ensuring the consistency of the ink color.

[0074] In some embodiments, the dispersant includes one or more of an organosiloxane polymer, a modified polyester, an acetylene alcohol compound, and a polyolefin wax; wherein the acetylene alcohol compound is provided as a propylene glycol solution of the acetylene alcohol compound; further optionally, the dispersant includes one or more of an organosiloxane polymer, a modified polyester, and a polyolefin wax. Adding an appropriate amount of dispersant can effectively disperse and wet the colorant, prevent the aggregation and sedimentation of the colorant, and thus ensure the consistency of the ink color.

[0075] In some embodiments, the defoamer includes one or more of an organosilicon defoamer, a polyether modified defoamer, and a mineral oil defoamer. Adding an appropriate amount of the defoamer can inhibit the generation and introduction of bubbles during the preparation and application of the ink, release the bubbles from the ink, and thus improve the quality and performance of the paint film.

[0076] In some embodiments, the leveling agent includes one or more of a polyether modified leveling agent, an organosilicon leveling agent, and a non-organosilicon leveling agent. Adding an appropriate amount of the leveling agent can improve the surface smoothness and flatness of the paint film, making the paint film more smooth and scratch-resistant.

[0077] In a second aspect of the present application, a method for preparing ink for an LED mask is provided, which is used to prepare the ink for an LED mask as described above.

[0078] In some embodiments, the method for preparing the ink for LED mask comprises the following steps:

[0079] S11: Prepare components for the LED mask ink as described above;

[0080] S12: mixing the base resin, part of the diluent, the dispersant, the accelerator and the leveling agent uniformly to obtain a mixed solution A;

[0081] S13: Evenly mix the mixed solution A, the weathering agent, the anti-settling agent and the colorant to obtain a mixed solution B;

[0082] S14: Evenly mix the mixed solution B, the remaining diluent and the defoaming agent to obtain a mixed solution C;

[0083] S15: Grind and filter the mixed solution C to obtain ink for LED mask.

[0084] In some embodiments, the mass ratio of the diluent added in step S12 to the diluent added in step S14 is (1~2):(1~2), including but not limited to 1:1, 1:1.5, 1:2, 1.5:1, 1.5:2, 2:1 or 2:1.5, and can further be 1:1.

[0085] In some embodiments, the grinding process is performed using a nano sand mill, the grinding speed is 800 rpm to 1500 rpm, and the grinding time is 30 min to 60 min. As an example, the grinding speed includes but is not limited to 800 rpm, 900 rpm, 1000 rpm, 1100 rpm, 1200 rpm, 1300 rpm, 1400 rpm, 1500 rpm; the grinding time includes but is not limited to 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min.

[0086] In some embodiments, the filtration process is performed using a mesh screen, and the mesh number of the mesh screen is ≥ 12000 meshes. It can be understood that the mesh number of the mesh screen is ≥ 12000 meshes, and the hole size on the mesh screen is ≤ 1.25 μm, that is, the fineness of the ink for LED masks is ≤ 1.25 μm, including but not limited to 1.25 μm, 1.2 μm, 1.1 μm, 1 μm, 0.9 μm, 0.8 μm, 0.7 μm, 0.6 μm, 0.5 μm, 0.2 μm or 0.1 μm.

[0087] In a third aspect of the present application, a method for preparing an LED mask is provided, which is a method for using the ink for an LED mask as described above.

[0088] In some embodiments, the method for preparing the LED mask comprises the following steps:

[0089] S21: mixing the ink for LED mask as described above and an organic solvent to obtain a diluted ink;

[0090] S22: spraying the semi-finished mask with diluted ink, and drying at 60° C. to 70° C. for 10 min to 15 min to obtain an LED mask.

[0091] In some embodiments, in step S21, the organic solvent includes one or more of toluene, xylene, trimethylbenzene, ethyl acetate, butyl acetate, acetone, isophorone and petroleum ether, and can further be selected as oil-opening water. Among them, oil-opening water is a mixed solvent containing organic solvents such as toluene and xylene, which is commonly used to dilute ink, adjust ink viscosity and coloring power, improve spray applicability, increase spraying area, and reduce raw material costs.

[0092] In some embodiments, in step S21, the mass ratio of the LED mask ink to the organic solvent is 1:(2-3), including but not limited to 1:2, 1:2.2, 1:2.4, 1:2.6, 1:2.8 or 1:3.

[0093] In some embodiments, in step S21, the LED mask ink and the organic solvent are stirred and diluted in a stirring barrel, and the stirring speed is 100 rpm to 150 rpm, for example, 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm, or 150 rpm.

[0094] In some embodiments, in step S22, the spraying process is performed under constant temperature and humidity conditions, wherein the constant temperature and humidity conditions may be: a temperature of 25° C. and a relative humidity of 60%.

[0095] In some embodiments, in step S22, a fuel spray gun is used; the fuel spray volume of the fuel spray gun is 180mL / min~240mL / min, for example, 180mL / min, 190mL / min, 200mL / min, 210mL / min, 220mL / min, 230mL / min or 240mL / min; the air pressure of the fuel spray gun is 0.05MPa~0.2MPa, for example, 0.05MPa, 0.08MPa, 0.1MPa, 0.12MPa, 0.15MPa, 0.18MPa or 0.2MPa.

[0096] In some embodiments, in step S22, after the spraying process, the mask is transported to an oven for drying by a spray reciprocator; the drying temperature is 60°C to 70°C, for example, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C; the drying time is 10min to 15min, for example, 10min, 11min, 12min, 13min, 14min or 15min.

[0097] In some embodiments, the thickness of the paint film formed on the surface of the LED mask is 20 μm to 30 μm. As an example, the thickness of the paint film formed on the surface of the LED mask includes but is not limited to 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm or 30 μm.

[0098] The following is further described in conjunction with specific embodiments and comparative examples. The raw materials involved in the following specific embodiments and comparative examples, unless otherwise specified, can all be commercially available, the instruments used, unless otherwise specified, can all be commercially available, and the processes involved, unless otherwise specified, are all routinely selected by those skilled in the art.

[0099] Example 1

[0100] (1) Referring to Table 1, the ink for LED mask of this embodiment includes the following components by mass fraction:

[0101] .

[0102] Wherein, the base resin is acrylate resin;

[0103] The diluent is n-butyl acetate, ethyl acetate and ethylene glycol monobutyl ether in a mass ratio of 1.5:1:1;

[0104] The colorant is Cabot BP880 carbon black, with a blackness of ≤30 and a specific surface area of ​​220m 2 / g, DBP oil absorption value is 105mL / 100g, particle size is 16nm, and tinting strength is 153%.

[0105] The accelerator is a phosphate compound;

[0106] The anti-settling agent is fumed silica;

[0107] The weathering agent is a compound of benzotriazole ultraviolet absorber UV-234 (2-(2-hydroxy-3',5'-dicumylphenyl)benzotriazole) and UV-622 (poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinylethanol) succinate) in a mass ratio of 1:1.

[0108] The dispersant is an organosiloxane polymer;

[0109] The defoaming agent uses mineral oil defoaming agent;

[0110] The leveling agent is a polyether modified leveling agent.

[0111] (2) The method for preparing the ink for LED mask provided in this embodiment comprises the following steps:

[0112] Prepare the LED mask ink components according to step (1);

[0113] Add half of the diluent, dispersant, accelerator and leveling agent to the base resin, stir evenly in a reactor to obtain a mixed solution A;

[0114] Add weathering agent, anti-settling agent and colorant to mixed solution A, stir evenly to obtain mixed solution B;

[0115] Mix the mixture B, the remaining half of the diluent and the defoamer, and stir evenly to obtain a mixture C;

[0116] The mixed solution C was transferred to a nano sand mill, stirred at a rotation speed of 1000 rpm for 45 minutes, and filtered through a 12000 mesh sieve to obtain an ink for LED masks.

[0117] (3) The method for preparing the LED mask provided in this embodiment comprises the following steps:

[0118] The LED mask ink and the oil-opening water described in step (1) are stirred and diluted in a stirring barrel at a mass ratio of 1:2 to obtain a diluted ink, and the ink is continuously stirred at a stirring rate of 120 rpm during the spraying process;

[0119] Under constant temperature and humidity conditions of 25°C and 60% relative humidity, the spray volume of the spray gun was controlled to be 200 mL / min and the air pressure to be 0.1 MPa, and the diluted ink was sprayed on the semi-finished mask. It was then transported to an oven through a spray reciprocating machine and dried at 65°C for 12 minutes to form a paint film with a thickness of 25 μm, thereby obtaining an LED mask.

[0120] Embodiment 2~4

[0121] The formulas of the inks for LED masks of Examples 2 to 4 are detailed in Table 1. The preparation methods of the inks for LED masks and the preparation methods of the LED masks are the same as those of Example 1.

[0122] Comparative Examples 1 to 5

[0123] The formulas of the inks for LED masks of Comparative Examples 1 to 5 are detailed in Table 1. The preparation methods of the inks for LED masks and the preparation methods of the LED masks are the same as those of Example 1.

[0124] Among them, the formula of the ink for LED mask of Comparative Example 5 is basically the same as that of Example 4, except that the pigment carbon black is replaced by ordinary carbon black, whose blackness is 32, DBP oil absorption value is 55mL / 100g, particle size is 40nm~60nm, and tinting strength is 65%.

[0125] Test Case

[0126] 1. Test items:

[0127] (1) Adhesion test: refer to GB / T 9286-1998 Cross-cut test for paint and varnish films.

[0128] (2) Alcohol resistance test: Use the spray method to make a 10μm paint film with ink for the LED mask, and use alcohol with a concentration of ≥99.7% to wipe it under the action of 500g force. It is required to wipe back and forth ≥50 times (one back and forth counts as one time) without exposing the primer.

[0129] (3) Blackness value test: refer to GB / T 7048-2012 Determination of blackness of carbon black.

[0130] (4) Ultraviolet (UV) radiation aging test: The LED mask is placed in a UV aging test chamber at a temperature of 80°C and an irradiation intensity of 0.76W / m 2 , irradiation exposure at a wavelength of 340nm for 8h, then exposure without irradiation and condensation for 4h at an ambient temperature of 50℃, a total of 12h is one cycle, and a total of 120 cycles (1440h) are performed. The color difference value of the LED mask before and after 120 cycles is tested.

[0131] (5) High temperature and high humidity test: Store the LED mask under high temperature and high humidity conditions of 85°C and 85% for 168 hours, and observe whether the paint film on the surface of the LED mask falls off.

[0132] (6) Hot and cold shock test: The LED mask is subjected to hot and cold shock from high temperature 80℃ to low temperature -40℃. Each temperature is maintained for 15 minutes. The time of each temperature change is less than 5 minutes. The cycle is repeated 252 times (168 hours). Observe whether the paint film on the surface of the LED mask falls off.

[0133] (II) Test results: The above test results are shown in Table 2.

[0134] As shown in Table 2, after the LED mask inks of Examples 1 to 4 were made into paint films, the adhesion reached 100%, and the number of wipes in the alcohol resistance test was between 82 and 88 times, which met the standard requirements.

[0135] After the ink for LED masks of Examples 1 to 4 is sprayed on the mask surface, the blackness value of the LED mask is ≤28.6, the color difference value before aging is ≤0.5, the color difference value after aging is ≤0.8, and the color difference value before and after aging is ≤0.3, which has the characteristics of high contrast, good ink color consistency and excellent aging resistance. At the same time, the paint film on the surface of the LED masks of Examples 1 to 4 did not fall off in the high temperature and humidity test and the hot and cold shock test, indicating that it has the characteristics of strong adhesion and high weather resistance under high temperature and humidity conditions and hot and cold shock conditions.

[0136] The ink for LED masks in Comparative Examples 1 to 3 does not add weathering agents. Although the blackness value can be controlled below 30, the color difference value after aging is between 1.14 and 1.51, and the aging resistance is poor. The ink for LED masks in Comparative Example 4 does not add dispersants and anti-settling agents, and its blackness value is 29.3. The color difference value before and after aging is significantly increased, with low contrast, poor ink color consistency and poor aging resistance. Comparative Example 5 replaces pigment carbon black with ordinary carbon black, and the blackness value reaches 35.3, and the color difference value after aging reaches 1.32. After the high temperature and high humidity test and the hot and cold shock test, the paint film shows slight shedding, which proves that pigment carbon black can not only improve the blackness, contrast and ink color consistency of the ink, but also significantly improve the aging resistance, weather resistance and adhesion.

[0137] In summary, the inks for LED masks of Examples 1 to 4 have the advantages of strong adhesion and good solvent resistance. Thanks to the added weathering agent and colorant, the LED masks prepared in Examples 1 to 4 have the advantages of high contrast, good ink color consistency and strong weather resistance.

[0138] Table 1. Formula of ink for LED mask (unit: wt%)

[0139]

[0140] Table 2. Performance of LED mask ink and reliability test of LED mask

[0141]

[0142] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0143] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of protection of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims.

Claims

1. An ink for LED mask, characterized in that: The components include the following mass fractions: ； Wherein, the colorant comprises carbon black pigment with a blackness of ≤30; The weathering agent comprises an ultraviolet absorber and a free radical scavenger in a mass ratio of (1-3): (1-3).

2. The LED mask ink according to claim 1, wherein: The particle size of the pigment carbon black is 10nm-25nm, and the DBP oil absorption value of the pigment carbon black is 80mL / 100g-120mL / 100g.

3. The LED mask ink according to claim 1, characterized in that: The ultraviolet absorber includes one or more of a benzotriazole ultraviolet absorber and a triazine ultraviolet absorber, and the free radical scavenger includes a hindered amine free radical scavenger.

4. The LED mask ink according to claim 1, characterized in that: The matrix resin includes one or more of acrylate resin, polyurethane resin and epoxy resin.

5. The ink for LED mask according to claim 1, characterized in that: The diluent includes one or more of n-butyl acetate, ethyl acetate and ethylene glycol monobutyl ether.

6. The ink for LED mask according to claim 5, characterized in that: The mass ratio of the n-butyl acetate, the ethyl acetate and the ethylene glycol monobutyl ether is (1-3):1:(1-2).

7. The LED mask ink according to any one of claims 1 to 6, characterized in that: One or more of the following conditions are met: (1) The accelerator includes one or more of an organic metal ester compound and a phosphate ester compound; (2) The anti-settling agent includes one or more of polyamide compounds, modified bentonite, fumed silica and hydroxyethyl cellulose; (3) The dispersant includes one or more of an organosiloxane polymer, a modified polyester, an acetylenic alcohol compound and a polyolefin wax; (4) The defoaming agent includes one or more of silicone defoaming agents, polyether modified defoaming agents and mineral oil defoaming agents; (5) The leveling agent includes one or more of a polyether modified leveling agent, a silicone leveling agent and a non-silicone leveling agent.

8. The ink for LED mask according to claim 7, characterized in that: The ink for LED mask includes the following components by mass fraction: 。 9. A method for preparing ink for LED mask, characterized in that: The following steps are involved: The ink preparation component for LED mask according to any one of claims 1 to 8; Mixing the base resin, part of the diluent, the dispersant, the accelerator and the leveling agent uniformly to obtain a mixed solution A; The mixed solution A, the weathering agent, the anti-settling agent and the colorant are mixed evenly to obtain a mixed solution B; The mixed solution B, the remaining diluent and the defoaming agent are mixed evenly to obtain a mixed solution C; The mixed solution C is ground and filtered to obtain the LED mask ink.

10. A method for preparing an LED mask, characterized in that: The following steps are involved: Mixing the ink for LED mask according to any one of claims 1 to 8 and an organic solvent to obtain a diluted ink; The semi-finished mask is sprayed with the diluted ink, and dried at 60° C. to 70° C. for 10 min to 15 min to obtain an LED mask.

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