Lamp surface composite coating and preparation method thereof as well as LED module and preparation method thereof

Abstract

The invention provides a lamp surface composite coating and a preparation method thereof as well as an LED module and a preparation method thereof. The lamp surface composite coating comprises a coating mixture and a volatile solvent, the coating mixture comprises an ink mixture and modified inorganic matte powder in a mass ratio of (9-12): (0.5-1.2); wherein the ink mixture is prepared from the following components in parts by mass: 50 to 60 parts of epoxy resin, 25 to 35 parts of filler, 15 to 20 parts of organic solvent, 1 to 5 parts of flatting agent and 1 to 5 parts of dispersing agent; the filler comprises at least one of nano carbon spheres and modified nano carbon spheres; the modified inorganic matt powder comprises inorganic matt powder and a surface treating agent, wherein the inorganic matt powder comprises at least one of gas-phase SiO2, micronized wax, silica powder and talcum powder. The lamp surface composite coating disclosed by the invention can have good heat dissipation performance, and when the lamp surface composite coating is applied to an LED module, the heat dissipation performance and the optical performance in an LED display screen and the adhesive force between lamp beads and a lamp panel can be improved at the same time, so that the display effect of an LED is improved.

Description

Technical Field

[0001] The invention relates to the technical field of LED display, and mainly to a lamp surface composite coating and a preparation method thereof, an LED module and a preparation method thereof. Background Art

[0002] LED (Light Emitting Diode) display screen is composed of multiple LED display modules. It has the advantages of wide display color gamut, high brightness, large viewing angle, low power consumption, long life and large size. It has a broad market in the fields of interior and exterior wall display in public places such as shopping malls, airports, and railway stations.

[0003] At present, during the operation of the LED screen, the efficiency of converting electrical energy into light energy is only 20%-30%, and the remaining 70-80% of electrical energy is converted into heat energy. Heat accumulation will affect the luminous efficiency of LED lamp beads and the working performance of other components. On the other hand, when the conventional ink is used to spray the LED light board, due to the low absorption rate of the traditional ink to visible light and the high gloss, when the visible light is irradiated to the surface of the light board, total reflection or specular reflection occurs, resulting in the problem of reflection affecting the perception. In the structure of the LED display module, since the LED lamp beads are soldered to the PCB (Printed Circuit Board) board through the lamp pins, the adhesion of the LED lamp beads on the lamp board is almost equal to the welding force between the lamp pins and the PCB board. At present, the lamp beads on the LED lamp board are glued in each row or in alternate rows, but the improvement of the thrust of the lamp beads is limited to a certain direction, so that the LED display module still has the problem of easy displacement during use, which affects the perception and life. Therefore, the influence of heat dissipation, optical performance and adhesion between the lamp beads and the lamp board on the display effect of the LED in the LED display screen needs to be solved urgently. Summary of the invention

[0004] In view of the fact that in the prior art, heat dissipation, optical performance and adhesion between lamp beads and lamp boards in LED display screens have obvious effects on the display effect of LEDs, the purpose of the present invention is to provide a lamp surface composite coating and a preparation method thereof, an LED module and a preparation method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] One aspect of the present invention provides a composite coating for a lamp surface, comprising a coating mixture and a volatile solvent;

[0007] The coating mixture comprises an ink mixture and a modified inorganic matte powder in a mass ratio of (9-12):(0.5-1.2);

[0008] Wherein, the ink mixture includes, by weight, 50 to 60 parts of epoxy resin, 25 to 35 parts of filler, 15 to 20 parts of organic solvent, 1 to 5 parts of leveling agent, and 1 to 5 parts of dispersant;

[0009] The filler includes at least one of nano carbon spheres and modified nano carbon spheres;

[0010] The modified inorganic matte powder comprises inorganic matte powder and a surface treatment agent, and the inorganic matte powder comprises at least one of gas-phase SiO2, micro-powder wax, silicon micro-powder and talcum powder.

[0011] In an optional embodiment, the mass ratio of the coating mixture to the volatile solvent is (9.5-13.2):(1-1.5).

[0012] In an optional embodiment, the volatile solvent includes at least one of ethyl acetate, acetone, and butanone.

[0013] In an optional embodiment, the particle size of the coating mixture is less than 30 um.

[0014] In an optional embodiment, the modified nano-carbon spheres include nano-carbon spheres and a coupling agent, and the coupling agent includes at least one of 3-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, and methacryloxypropyltrimethoxysilane.

[0015] In an optional embodiment, the filler further includes at least one of silicon carbide and graphene;

[0016] In an optional embodiment, the surface treatment agent includes at least one of silane coupling agents such as hexamethyldisilazane, hexamethylvinylsilazane, and vinylethoxysilane.

[0017] In an optional embodiment, the particle size of the nano-carbon spheres ranges from 60 to 200 nm.

[0018] In an optional embodiment, the epoxy resin includes at least one of bisphenol A epoxy resin, novolac epoxy resin, and bisphenol A epoxy resin.

[0019] In an optional embodiment, the organic solvent includes at least one of propylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, ethylene glycol monobutyl ether, and dipropylene glycol methyl ether.

[0020] In an optional embodiment, the leveling agent includes at least one of a polyether polyester modified organic siloxane and a phosphate ester modified acrylic leveling agent.

[0021] In an alternative embodiment, the dispersant comprises sodium dodecyldibenzene disulfonate.

[0022] A second aspect of the present invention provides a method for preparing a composite coating for a lamp surface, which is used to prepare the composite coating for a lamp surface as described in any one of the above embodiments, and the preparation method comprises the following steps:

[0023] S1: stirring the epoxy resin at a first preset speed, then adding the filler, the organic solvent and the dispersant, and stirring at a second preset speed to obtain a dispersed mixed liquid, wherein the second preset speed is greater than the first preset speed;

[0024] S2: adding the leveling agent into the dispersed mixed liquid, and stirring at a third preset speed to obtain the ink mixture;

[0025] S3: mixing and grinding the ink mixture and the modified inorganic matte powder to obtain the coating mixture.

[0026] In an optional implementation, the first preset rotation speed is 800-1000 rpm.

[0027] In an optional implementation, the second preset rotation speed is 1800-2000 rpm.

[0028] In an optional implementation, the third preset rotation speed is 800-1000 rpm.

[0029] The third aspect of the present invention provides an LED module, comprising a lamp board, lamp beads and a coating, wherein the coating is formed by applying the lamp surface composite coating described in any of the above embodiments to the surface of the lamp board, the lamp beads are arranged on the surface of the lamp board, the lamp surface composite coating covers the surface of the lamp board and fills the gap between the lamp beads and the lamp board.

[0030] In an optional embodiment, the lamp bead includes a chip and a pin connected to the chip, and one end of the pin away from the bottom of the chip is connected to the surface of the lamp board, forming the gap between the chip and the light board; the thickness of the coating is greater than the distance from the bottom of the chip to the surface of the light board, so that the pin is covered in the coating.

[0031] The fourth aspect of the present invention provides a method for preparing an LED module, wherein the LED module is prepared by using the lamp surface composite coating described in any of the above embodiments, and the method for preparing the LED module comprises the following steps:

[0032] S10: spraying a volatile solvent on the surface of the lamp board so that the lamp board is wetted by the volatile solvent, and then spraying the coating mixture on the surface of the lamp board; or, mixing the coating mixture and the volatile solvent to obtain a lamp surface composite coating, and spraying the lamp surface composite coating on the surface of the lamp board;

[0033] S20: Drying the lamp board until the volatile solvent is completely evaporated to obtain the LED module.

[0034] It can be seen from the above technical solution that the advantages and positive effects of the present invention are:

[0035] In the lamp surface composite coating disclosed in the present application, by using epoxy resin as a binder in the coating mixture, the prepared lamp surface composite coating has a certain degree of adhesion, and thus can have a better bonding force with the lamp board, thereby improving the problem of poor adhesion between the lamp beads and the lamp board; further, since the nano-carbon balls have high thermal conductivity and high emissivity, and the color of the nano-carbon balls after high-temperature carbonization is black, they can be used as pigments and heat dissipation fillers in the lamp surface composite coating at the same time, while improving the heat dissipation performance of the ink, and significantly improving the surface radiation heat dissipation capacity of the LED lamp board. Moreover, the use of inorganic matte powder as the matte filler in the lamp surface composite material, combined with the ink mixture, can make the surface of the LED lamp board matte frosted black, with diffuse reflection of light, and after being coated on the LED lamp board, it can achieve a matte effect and have a certain wear resistance.

[0036] The coating mixture made of the ink mixture and the modified inorganic matte powder is combined with a volatile solvent. Since the volatile solvent has the characteristic of being easy to volatilize, the lamp surface composite coating of the present application has excellent dispersibility and compatibility. When the lamp surface composite coating is applied on the surface of the LED light board, the problem of incomplete coverage on the light board due to the high viscosity of the coating mixture and the difficulty in dispersion can be avoided. Moreover, the use of the coating mixture and the volatile solvent allows the lamp surface composite coating to be more evenly dispersed and cover the surface of the light board. After the volatile solvent evaporates, the lamp surface composite coating can fill the gap between the lamp surface and the lamp beads, thereby completely wrapping the bottom of the lamp beads, further improving the adhesion between the lamp beads and the light board, while not affecting the coating effect of the lamp surface composite coating on the surface of the light board. Therefore, the lamp surface composite coating of the present application can improve the display effect of the LED by simultaneously improving the heat dissipation, optical properties and adhesion between the lamp beads and the light board in the LED display screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a flow chart of the steps of a method for preparing a composite coating for a lamp surface in one embodiment of the present application;

[0038] Figure 2 This is a cross-sectional schematic diagram of an LED module in one embodiment of the present application;

[0039] Figure 3 The following is a flowchart of the steps of the method for preparing an LED module in one embodiment of the present application; wherein the corresponding relationship between the reference numerals and the component names is as follows:

[0040] 100. LED module;

[0041] 1. Light board;

[0042] 2. lamp beads; 21. chips; 22. pins; 201. gaps;

[0043] 3. Coating. DETAILED DESCRIPTION

[0044] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work, all belong to the scope of protection of the present invention. If specific conditions are not indicated in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0045] As used herein, the term "prepared from" is synonymous with "comprising". As used herein, the terms "comprising", "including", "having", "containing" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0046] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0047] In these examples, parts and percentages are by mass unless otherwise indicated.

[0048] "Parts by mass" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass of all components is not limited to 100 parts.

[0049] At present, during the operation of the LED screen, the efficiency of converting electrical energy into light energy is only 20%-30%, and the remaining 70-80% of electrical energy is converted into heat energy. Heat accumulation will affect the luminous efficiency of LED lamp beads and the working performance of other components. On the other hand, when the conventional ink is used to spray the LED light board, due to the low absorption rate of the traditional ink to visible light and the high gloss, when the visible light is irradiated to the surface of the light board, total reflection or specular reflection occurs, resulting in the problem of reflection affecting the perception. In the structure of the LED display module, since the LED lamp beads are soldered to the PCB (Printed Circuit Board) board through the lamp pins, the adhesion of the LED lamp beads on the lamp board is almost equal to the welding force between the lamp pins and the PCB board. At present, the lamp beads on the LED lamp board are glued in each row or in alternate rows, but the improvement of the thrust of the lamp beads is limited to a certain direction, so that the LED display module still has the problem of easy displacement during use, which affects the perception and life. Therefore, the influence of heat dissipation, optical performance and adhesion between the lamp beads and the lamp board on the display effect of the LED in the LED display screen needs to be solved urgently.

[0050] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0051] The first aspect of the embodiment of the present application provides a composite coating for a lamp surface, comprising a coating mixture and a volatile solvent; the coating mixture comprises an ink mixture and a modified inorganic matte powder in a mass ratio of (9-12):(0.5-1.2); wherein, in parts by mass, the ink mixture comprises 50-60 parts of epoxy resin, 25-35 parts of filler, 15-20 parts of organic solvent, 1-5 parts of leveling agent, and 1-5 parts of dispersant; the filler comprises at least one of nano-carbon spheres and modified nano-carbon spheres; the modified inorganic matte powder comprises an inorganic matte powder and a surface treatment agent, and the inorganic matte powder comprises at least one of vapor-phase SiO2, micro-powder wax, silicon micro-powder, and talcum powder.

[0052] In the lamp surface composite coating provided in the embodiment of the present application, by using epoxy resin as a binder in the coating mixture, the prepared lamp surface composite coating has a certain degree of adhesion, and thus can have a better bonding force with the lamp board, thereby improving the problem of poor adhesion between the lamp beads and the lamp board; further, since the nano-carbon balls have high thermal conductivity and high emissivity, and the color of the nano-carbon balls after high-temperature carbonization is black, they can be used as pigments and heat dissipation fillers in the lamp surface composite coating, while improving the heat dissipation performance of the ink, and significantly improving the surface radiation heat dissipation capacity of the LED lamp board. Moreover, inorganic matte powder is used as the matte filler in the lamp surface composite material, and combined with the ink mixture, the surface of the LED lamp board can be matte frosted black, which has a diffuse reflection effect on light. After being coated on the LED lamp board, it can achieve a matte effect and have a certain wear resistance.

[0053] The coating mixture made of the ink mixture and the modified inorganic matte powder is combined with a volatile solvent. Since the volatile solvent has the characteristic of being easy to volatilize, the lamp surface composite coating of the present application has excellent dispersibility and compatibility. When the lamp surface composite coating is applied on the surface of the LED light board, the problem of incomplete coverage on the light board due to the high viscosity of the coating mixture and the difficulty in dispersion can be avoided. Moreover, the use of the coating mixture and the volatile solvent allows the lamp surface composite coating to be more evenly dispersed and cover the surface of the light board. After the volatile solvent evaporates, the lamp surface composite coating can fill the gap between the lamp surface and the lamp beads, thereby completely wrapping the bottom of the lamp beads, further improving the adhesion between the lamp beads and the light board, while not affecting the coating effect of the lamp surface composite coating on the surface of the light board. Therefore, the lamp surface composite coating of the present application can improve the display effect of the LED by simultaneously improving the heat dissipation, optical properties and adhesion between the lamp beads and the light board in the LED display screen.

[0054] It should be noted that since inorganic matte powder usually has a hydrophilic surface, the inorganic matte powder can be treated with a surface treatment agent to make its surface hydrophobic, thereby improving the dispersibility and compatibility of the inorganic matte powder in the epoxy resin. This can solve the problem that the unmodified inorganic matte powder may be difficult to disperse evenly in the epoxy resin, resulting in agglomeration, precipitation or stratification of the coating.

[0055] In a possible embodiment, the mass ratio of the coating mixture to the volatile solvent is (9.5-13.2):(1-1.5).

[0056] Due to the inclusion of epoxy resin, the overall viscosity of the coating mixture is high. When sprayed on the surface of the lamp board, it is easy to be difficult to disperse on the surface of the lamp board, resulting in poor coating effect. Within the mass ratio range of the coating mixture and the volatile solvent, the dispersion and uniform coating effect of the coating mixture on the surface of the lamp board can be effectively improved, so that the composite coating on the lamp surface can fully fill the gap between the lamp bead and the lamp board, thereby completely wrapping the bottom of the lamp bead to improve the bonding force between the lamp bead and the lamp board.

[0057] In a possible embodiment, the modified nano-carbon spheres include nano-carbon spheres and a coupling agent, and the coupling agent includes at least one of 3-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, and methacryloxypropyltrimethoxysilane.

[0058] Among them, by using a coupling agent to modify the surface of the nanocarbon spheres and then introducing organic functional groups into the surface of the nanocarbon spheres, their ability to bind to the epoxy resin can be further enhanced.

[0059] In a possible embodiment, the filler further includes at least one of silicon carbide and graphene.

[0060] Among them, since silicon carbide and graphene are fillers with high thermal conductivity, they can improve the distribution state of the lamp surface composite coating on the LED lamp board, which can not only make the lamp surface composite coating more evenly coated on the surface of the lamp board, but also further improve the radiation heat dissipation performance of the lamp surface composite coating.

[0061] In a possible embodiment, the volatile solvent includes at least one of ethyl acetate, acetone, and butanone.

[0062] In a possible embodiment, the particle size of the coating mixture is less than 30um. On the one hand, by controlling the particle size of the coating mixture within a range of less than 30um, when light is irradiated on the coating surface, more diffuse reflection occurs, thereby reducing specular reflection and glare. The use of the composite coating on the lamp surface is conducive to making the LED lamp surface visually softer and more comfortable, avoiding the impact of reflection and glare on the perception.

[0063] On the other hand, grinding can be performed during the mixing process of the ink mixture and the modified inorganic matte powder until the particle size is less than 30um, so that the ink mixture and the modified inorganic matte powder can be fully mixed, and the modified inorganic matte powder can be evenly dispersed in the ink mixture to form a coating mixture. The ink mixture and the modified inorganic matte powder have good compatibility, so that stratification, agglomeration or precipitation is not easy to occur, which helps to maintain the stability and consistency of the lamp surface composite coating, thereby improving the coating performance and final effect of the lamp surface composite coating.

[0064] In a possible embodiment, the surface treatment agent includes at least one of silane coupling agents such as hexamethyldisilazane, hexamethylvinylsilazane, and vinylethoxysilane.

[0065] Since the compatibility and dispersibility between inorganic matte powder and epoxy resin will affect the composite coating of the lamp surface, the inorganic matte powder is surface modified by using a surface treatment agent to change its surface from hydrophilic to hydrophobic. The modified inorganic matte powder can be more evenly dispersed in the epoxy resin, reducing the occurrence of agglomeration and precipitation. At the same time, since the modified inorganic matte powder can form a chemical bond with the epoxy resin, the bonding force between the inorganic matte powder and the epoxy resin is enhanced, so that the coating has a matte frosted black color after curing, and has better stability and durability.

[0066] In a possible embodiment, the particle size range of the nano-carbon spheres is 60 to 200 nm. Among them, the nano-carbon spheres within this particle size range can have a specific surface area suitable for the composite coating of the lamp surface, and thus are more suitable for the heat dissipation effect and thermal conductivity of the LED module. At the same time, the nano-carbon spheres within this particle size range have the advantages of good dispersibility and compatibility with the epoxy resin matrix, making it easier for the nano-carbon spheres to be evenly dispersed in the epoxy resin and the inorganic matte powder, which is beneficial to improve the coating effect and optical performance of the composite coating on the lamp surface on the lamp board.

[0067] Preferably, the particle size of the nano carbon spheres is in the range of 90 nm.

[0068] In a possible embodiment, the epoxy resin includes at least one of bisphenol A epoxy resin, novolac epoxy resin, and bisphenol A epoxy resin.

[0069] Among them, the epoxy resin can be one of bisphenol A epoxy resin, phenolic epoxy resin, bisphenol A epoxy resin, or a combination of at least two or more groups. Since bisphenol A epoxy resin, phenolic epoxy resin, and bisphenol A epoxy resin are epoxy resins with smaller molecular weights, their molecular chains are shorter and they are easier to penetrate into the surface of the lamp board, making it easier for the lamp surface composite coating to form a strong chemical bond with the surface of the lamp board and the lamp beads between the lamp board surfaces, thereby improving the adhesion of the lamp surface composite coating on the lamp board surface and the adhesion between the lamp beads and the lamp board.

[0070] In a possible embodiment, the organic solvent includes at least one of propylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, ethylene glycol monobutyl ether, and dipropylene glycol methyl ether.

[0071] In a possible embodiment, the leveling agent includes at least one of a polyether polyester modified organic siloxane and a phosphate ester modified acrylic leveling agent.

[0072] By adopting the above-mentioned leveling agent, the surface tension of the composite coating on the lamp surface can be reduced, and the uniform spreading of the coating on the substrate can be promoted, thereby reducing defects such as brush marks, orange peel, pinholes, etc. on the coating surface, making the coating applied on the surface of the lamp panel smoother and flatter.

[0073] In one possible embodiment, the dispersant includes sodium dodecyl dibenzene disulfonate.

[0074] Please see attached Figure 1 The second aspect of the embodiment of the present application provides a method for preparing a composite coating for a lamp surface, which is used to prepare the composite coating for a lamp surface of any of the above embodiments, and the preparation method comprises the following steps:

[0075] S1: stirring the epoxy resin at a first preset speed, then adding filler, organic solvent and dispersant, and stirring at a second preset speed to obtain a dispersed mixed liquid, wherein the second preset speed is greater than the first preset speed;

[0076] S2: adding a leveling agent into the dispersed mixed liquid, and stirring at a third preset speed to obtain an ink mixture;

[0077] S3: mixing and grinding the ink mixture and the modified inorganic matte powder to obtain a coating mixture;

[0078] Specifically, before performing step S1, 50-60 parts of epoxy resin, 25-35 parts of nano-carbon spheres, 15-20 parts of organic solvent, 1-5 parts of leveling agent, and 1-5 parts of dispersant may be weighed in parts by mass.

[0079] In step S1, the nano-carbon spheres can be fully dispersed in the epoxy resin by physical means of oscillating grinding and high-speed dispersion, and the interfacial tension between the two phases can be reduced by adding a dispersant to improve the compatibility and dispersibility between the nano-carbon spheres and the epoxy resin.

[0080] The second preset speed may be greater than the first preset speed. Since the addition of nano-carbon balls, organic solvents and dispersants may increase the viscosity of the system or change its fluidity, the second preset speed is designed to be greater than the first preset speed, which is conducive to fully mixing all components.

[0081] Specifically, the first preset rotation speed may be 800-1000 rpm, and the second preset rotation speed may be 1800-2000 rpm.

[0082] In step S2, a leveling agent is added to the dispersed mixed liquid in S1 and stirred at a third preset speed so that the leveling agent can be evenly dispersed in the coating system, which is beneficial to improving the fluidity and flatness of the subsequently prepared lamp surface composite coating.

[0083] Specifically, the third preset rotation speed may be 800-1000 rpm.

[0084] In step S3, the ink mixture is mixed with the modified inorganic matte powder (surface-treated inorganic matte powder) and ground. The purpose of this step is to evenly disperse the modified inorganic matte powder in the ink mixture to form a uniform coating mixture. Moreover, the grinding process helps to reduce the particle size of the coating mixture, improve the fineness and uniformity of the coating, so that the coating formed on the surface of the light board can have a more uniform matte black texture, and further improve the dispersibility of the modified inorganic matte powder in the ink mixture.

[0085] Among them, the ink mixture and the modified inorganic matte powder in a mass ratio of (9-12): (0.5-1.2) can be mixed and ground until the fineness of the mixture of the ink mixture and the modified inorganic matte powder is less than 30um to obtain a lamp surface composite coating. In this step, the modified inorganic matte powder can be evenly dispersed in the ink mixture to form a uniform coating mixture. The grinding process helps to reduce the particle size and improve the fineness and uniformity of the coating.

[0086] It should be noted that the surface treatment agent can react with the inorganic matte powder by heating and mixing to modify the surface of the inorganic matte powder to make the surface hydrophobic, thereby improving the dispersibility and compatibility of the inorganic matte powder in the epoxy resin.

[0087] Furthermore, the preparation method of the lamp surface composite coating also includes: mixing the coating mixture with a volatile solvent to obtain the lamp surface composite coating.

[0088] Specifically, in some embodiments, when the lamp surface composite coating is used, the volatile solvent is first evenly sprayed on the surface of the lamp board, and then the coating mixture is coated on the surface of the lamp board soaked with the volatile solvent, and the coating mixture and the volatile solvent are mixed and compatible on the surface of the lamp board.

[0089] In the above-mentioned use process, the mass ratio of the coating mixture to the volatile solvent is (9.5-13.2):(1-1.5).

[0090] In some other embodiments, when the lamp surface composite coating is used, the coating mixture and the volatile solvent may be mixed first, and then the mixture, ie, the lamp surface composite coating, may be coated on the surface of the lamp panel.

[0091] In the above-mentioned use process, the mass ratio of the coating mixture and the volatile solvent is (9.5~13.2):(1.5~2). Figure 2The third aspect of the embodiment of the present application provides an LED module 100, including a lamp board 1, lamp beads 2 and a coating 3, wherein the coating 3 is formed by applying the lamp surface composite coating described in any of the above embodiments to the surface of the lamp board 1, the lamp beads 2 are arranged on the surface of the lamp board 1, the lamp surface composite coating covers the surface of the lamp board 1, and fills the gap 201 between the lamp beads 2 and the lamp board 1.

[0092] Among them, by using the lamp surface composite coating described in any of the above embodiments to be coated on the surface of the lamp board 1, the lamp surface composite coating is cured to form a coating 3. Since the coating 3 contains nano-carbon balls, the coating 3 can enhance the radiation heat dissipation capacity of the lamp board 1, so that the heat generated by the LED module 100 during operation can be more effectively dissipated, avoiding heat accumulation, thereby improving the luminous efficiency and working stability of the lamp beads 2. Compared with the prior art of improving the heat dissipation effect by changing the material and structure of the LED screen body and adding fans and other equipment, the coating 3 used in this application is more direct and effective.

[0093] Moreover, the inorganic matte powder in the coating 3 acts as a matte filler, making the surface of the lamp board 1 in the LED module 100 matte and frosted black, which has a diffuse reflection effect on light and achieves a matte effect. This not only effectively solves the reflection problem of the lamp board 1, but also improves the visual comfort of the lamp board 1. At the same time, the inorganic matte powder also has a certain wear resistance, which helps to extend the service life of the LED module 100.

[0094] In terms of improving the adhesion between the lamp bead 2 and the lamp board 1, the epoxy resin in the lamp surface composite coating is used as a binder, which has higher mechanical strength and bonding strength than other resins, so that the bonding force between the lamp bead 2 and the lamp board 1 is significantly strengthened. At the same time, before coating the lamp board 1, the volatile solvent is used to improve its fluidity on the surface of the LED lamp board 1, so that the lamp surface composite coating can fully fill the space between the lamp bead 2 and the lamp board 1, thereby completely wrapping the bottom of the lamp bead 2, enhancing the adhesion between the lamp bead 2 and the lamp board 1, so that the LED module 100 can have a stable display effect and a longer service life.

[0095] like Figure 2 As shown, in some embodiments, the lamp bead 2 includes a chip 21 and a pin 22 connected to the chip 21, and one end of the pin 22 away from the chip 21 is connected to the surface of the lamp board 1, and a gap 201 is formed between the pin 22 and the chip 21. The thickness of the coating 3 is greater than the distance from the bottom of the chip 21 to the surface of the lamp board 1, so that the pin 22 is covered in the coating 3.

[0096] Specifically, the lamp bead 2 is composed of a chip 21 and a pin 22, and one end of the pin 22 away from the bottom of the chip 21 is connected to the surface of the lamp board 1 to form an electrical connection. After the lamp surface composite coating is applied to the lamp board 1, a coating 3 is formed on the surface of the lamp board 1, and the coating 3 completely covers the pin 22, and at the same time fills the gap 201 between the pin 22 and the lamp board 1. The thickness of the coating 3 is greater than the distance from the bottom of the chip 21 to the surface of the lamp board 1. Compared with the solution of connecting the pin 22 to the lamp bead 2 by dispensing in the prior art, the coating 3 of the present application can cover the entire surface of the lamp board 1, and as a bottom filling layer, completely wrap the bottom of the lamp bead 2 in all directions, thereby effectively strengthening the bonding force between the pin 22 of the lamp bead 2 and the surface of the lamp board 1, strengthening the thrust of the lamp bead 2, and improving product reliability.

[0097] Please see attached Figure 3 A fourth aspect of the embodiments of the present application provides a method for preparing an LED module, wherein the LED module is prepared by using the lamp surface composite coating according to any of the above embodiments, and the method for preparing the LED module comprises the following steps:

[0098] S10: spraying a volatile solvent on the surface of the lamp board so that the lamp board is wetted by the volatile solvent, and then spraying the coating mixture on the surface of the lamp board; or, mixing the coating mixture and the volatile solvent to obtain a lamp surface composite coating, and then spraying the lamp surface composite coating on the surface of the lamp board;

[0099] S20: spraying the coating mixture on the surface of the lamp board, and then drying the lamp board until the volatile solvent is completely evaporated to obtain an LED module.

[0100] Specifically, in step S10, after the volatile solvent is sprayed on the surface of the lamp board and the surface of the lamp board is fully wetted by naked eye observation, the coating mixture is sprayed on the surface of the lamp board. Since the volatile solvent has good compatibility with the composite coating on the lamp surface, the volatile solvent can play a "priming" role, which is conducive to the coating mixture having good fluidity when sprayed on the surface of the lamp board, and further conducive to the uniform coating and adhesion of the composite coating on the lamp surface on the surface of the lamp board, so that a uniform, dense and firm coating can be formed after drying.

[0101] Furthermore, due to the surface tension of the composite coating on the lamp surface formed by the coating mixture and the volatile solvent, it can be filled from the gaps in the lamp beads to the bottom of the lamp beads and between the lamp board. The coating thus formed can completely wrap the bottom of the lamp beads in all directions, thereby comprehensively improving the bonding strength between the lamp beads and the lamp board.

[0102] In step S20, the lamp panel is dried. Since the volatile solvent is volatile, it can be completely evaporated in the subsequent drying process, and does not affect the curing effect of the lamp surface composite coating on the lamp surface.

[0103] Specifically, the coating mixture may be sprayed onto the surface of the lamp panel using an inkjet machine.

[0104] In another embodiment, a method for preparing an LED module comprises mixing a coating mixture and a volatile solvent to obtain a lamp surface composite coating, and then spraying the lamp surface composite coating on the surface of a lamp board; spraying the lamp surface composite coating on the surface of the lamp board, and then drying the lamp board until the volatile solvent is completely evaporated to obtain an LED module.

[0105] The coating mixture and the volatile solvent may be premixed so that the lamp surface composite coating has suitable fluidity and viscosity before being sprayed on the surface of the lamp board, so as to flow evenly on the surface of the lamp board, thereby forming a more uniform and denser coating on the surface of the lamp board.

[0106] The lamp surface composite coating of the present application is further described in detail below in conjunction with the embodiments.

[0107] Example 1

[0108] Embodiment 1 provides an LED module, which is prepared by the following method:

[0109] According to weight, 50 parts of bisphenol A epoxy resin, 25 parts of nano carbon spheres, 15 parts of propylene glycol methyl ether acetate, 1 part of polyether polyester modified organosiloxane, and 1 part of sodium dodecyl diphenyl disulfonate are weighed; wherein the nano carbon spheres with a particle size of 60 nm are used;

[0110] The bisphenol A epoxy resin was stirred at 800 rpm, and then the nano carbon spheres, propylene glycol methyl ether acetate and sodium dodecyl dibenzene disulfonate were added, and then stirred at 1800 rpm to obtain a dispersed mixed liquid;

[0111] Adding polyether polyester modified organosiloxane into the dispersed mixed liquid, stirring at 800 rpm to obtain an ink mixture;

[0112] The ink mixture and the modified gas-phase SiO2 in a mass ratio of 9:1.2 are mixed and ground to obtain a coating mixture, wherein the gas-phase SiO2 is modified by hexamethyldisilazane to obtain the modified gas-phase SiO2;

[0113] Weigh a coating mixture and ethyl acetate in a mass ratio of 9.5:1.5, and spray the ethyl acetate on the surface of the lamp board so that the lamp board is wetted by the ethyl acetate;

[0114] The coating mixture is sprayed on the surface of the lamp board, and then the lamp board is dried until the ethyl acetate is completely volatilized to obtain an LED module.

[0115] Example 2

[0116] Embodiment 2 provides an LED module, which is prepared by the following method:

[0117] According to weight, 60 parts of phenolic epoxy resin, 35 parts of nano carbon spheres, 20 parts of diethylene glycol ethyl ether acetate, 5 parts of phosphate-modified acrylic acid, and 5 parts of sodium dodecyl dibenzene disulfonate were weighed; wherein the nano carbon spheres with a particle size of 200 nm were used;

[0118] The phenolic epoxy resin was stirred at a speed of 1000 rpm, and then the nano carbon spheres, diethylene glycol ethyl ether acetate and sodium dodecyl dibenzene disulfonate were added, and then the mixture was stirred at a speed of 2000 rpm to obtain a dispersed mixed liquid;

[0119] Adding phosphate-modified acrylic acid into the dispersed mixed liquid, stirring at a rotation speed of 1000 rpm to obtain an ink mixture;

[0120] The ink mixture and modified talc powder in a mass ratio of 12:0.5 are mixed and ground to obtain a coating mixture, wherein the talc powder is modified by using hexamethylvinylsilazane to obtain the modified talc powder;

[0121] Weigh a coating mixture and acetone in a mass ratio of 13.2:1, and spray the acetone on the surface of the lamp board so that the lamp board is wetted by the acetone;

[0122] The coating mixture is sprayed on the surface of the lamp board, and then the lamp board is dried until the acetone is completely volatilized to obtain an LED module.

[0123] Example 3

[0124] Embodiment 3 provides an LED module, which is prepared by the following method:

[0125] According to weight parts, weigh 50 parts of bisphenol A epoxy resin, 25 parts of modified nano carbon spheres, 15 parts of propylene glycol methyl ether acetate, 1 part of polyether polyester modified organosiloxane, and 1 part of sodium dodecyl diphenyl disulfonate;

[0126] The bisphenol A epoxy resin was stirred at 800 rpm, and then modified nano-carbon spheres, propylene glycol methyl ether acetate and sodium dodecyl dibenzene disulfonate were added, and then stirred at 1800 rpm to obtain a dispersed mixed solution, wherein the modified nano-carbon spheres were obtained by modifying the nano-carbon spheres with a coupling agent KH550 (aminopropyltriethoxysilane), and the particle size of the nano-carbon spheres was 130 nm;

[0127] Adding polyether polyester modified organosiloxane into the dispersed mixed liquid, stirring at 800 rpm to obtain an ink mixture;

[0128] The ink mixture and the modified gas-phase SiO2 in a mass ratio of 10:1 are mixed and ground to obtain a coating mixture, wherein the gas-phase SiO2 is modified by hexamethyldisilazane to obtain the modified gas-phase SiO2;

[0129] Weigh a coating mixture and ethyl acetate in a mass ratio of 11:1, and spray the ethyl acetate on the surface of the lamp board so that the lamp board is wetted by the ethyl acetate;

[0130] The coating mixture is sprayed on the surface of the lamp board, and then the lamp board is dried until the ethyl acetate is completely volatilized to obtain an LED module.

[0131] Example 4

[0132] Embodiment 4 provides an LED module, which is prepared by the following method:

[0133] According to weight parts, weigh 50 parts of bisphenol A epoxy resin, 25 parts of nano carbon spheres, 15 parts of propylene glycol methyl ether acetate, 1 part of polyether polyester modified organosiloxane, and 1 part of sodium dodecyl diphenyl disulfonate;

[0134] The bisphenol A epoxy resin was stirred at 800 rpm, and then the nano carbon spheres, propylene glycol methyl ether acetate and sodium dodecyl dibenzene disulfonate were added, and then stirred at 1800 rpm to obtain a dispersed mixed liquid;

[0135] Adding polyether polyester modified organosiloxane into the dispersed mixed liquid, stirring at 800 rpm to obtain an ink mixture;

[0136] The ink mixture and the modified gas-phase SiO2 in a mass ratio of 10:1 are mixed and ground to obtain a coating mixture, wherein the gas-phase SiO2 is modified by hexamethyldisilazane to obtain the modified gas-phase SiO2;

[0137] Weighing and mixing the lamp surface composite coating and the volatile solvent in a mass ratio of 9:1 to obtain the lamp surface composite coating;

[0138] The lamp surface composite coating is sprayed on the surface of the lamp board, and then the lamp board is dried until the volatile solvent is completely evaporated to obtain the LED module.

[0139] Comparative Example 1

[0140] Comparative Example 1 provides a conventional ink-sprayed LED module, which is prepared by the following method:

[0141] Conventional ink of the same gram weight as that of Examples 1 to 4 is sprayed on the lamp board by an inkjet device, wherein the main components of the conventional ink are: 52% to 62% acrylic resin, 32% to 35% graphite powder, 4% to 8% additives, and 5% to 10% mixed solvent. After spraying, the lamp board is baked to cure the ink to obtain the LED module.

[0142] The coating effect test was performed on the LED modules in Examples 1 to 4 and Comparative Example 1. The performances are shown in Table 1.

[0143] Specifically, the LED modules in Examples 1 to 4 and Comparative Example 1 were aged for 8 hours, the surface temperature of the lamp board was tested with an infrared temperature measuring gun, and a thrust test was performed.

[0144] Specifically, after the IED module is powered on and the light is turned on, a white screen is displayed for 8 hours. Then, the surface temperature of the lamp board at five points, namely the upper left, lower left, upper right, lower right and center, is tested using an infrared temperature gun. The average temperature of the five points is then taken as the surface temperature of the lamp board.

[0145] In the thrust test, take 5 points at the upper left, lower left, upper right, lower right and center, use the thrust tester to completely push down the lamp beads on the IED module, record the maximum value of the thrust tester, and then take the thrust average of these 5 points as the thrust average of the lamp board.

[0146] Table 1 Coating effect of LED module

[0147] Surface temperature Thrust average Coating surface effect Example 1 55.1℃ 2.78Kg Matte matte black Example 2 53.0℃ 2.57Kg Matte matte black Example 3 51.8℃ 2.62Kg Matte matte black Example 4 55.9℃ 2.75Kg Matte matte black Comparative Example 1 65.2℃ 2.05Kg Bright Black

[0148] It can be seen from the above table that the fillers in Examples 1 to 4 are nano-carbon balls and modified nano-carbon balls. Compared with Comparative Example 1, after lighting and aging for 8 hours, the surface temperature of the lamp boards in Examples 1 to 4 is lower, indicating that the lamp surface composite coating disclosed in the present application has better heat dissipation performance; the binder resin in Examples 1 to 4 is epoxy resin. Compared with Comparative Example 1, the thrust of the lamp beads is significantly improved, indicating that the lamp surface composite coating disclosed in the present application can strengthen the bonding force between the lamp beads and the PCB board; modified inorganic matte powder is added in Examples 1 to 4. Compared with Comparative Example 1, the lamp surface is matte frosted black, indicating that the lamp surface composite coating disclosed in the present application has a good extinction effect.

[0149] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A composite coating for lamp surface, characterized in that: Includes coating mixtures and volatile solvents; The coating mixture comprises an ink mixture and a modified inorganic matte powder in a mass ratio of (9-12):(0.5-1.2); Wherein, the ink mixture includes, by weight, 50 to 60 parts of epoxy resin, 25 to 35 parts of filler, 15 to 20 parts of organic solvent, 1 to 5 parts of leveling agent, and 1 to 5 parts of dispersant; The filler includes at least one of nano carbon spheres and modified nano carbon spheres; The modified inorganic matte powder comprises inorganic matte powder and a surface treatment agent, and the inorganic matte powder comprises at least one of gas-phase SiO2, micro-powder wax, silicon micro-powder and talcum powder.

2. The lamp surface composite coating according to claim 1, characterized in that: The mass ratio of the coating mixture to the volatile solvent is (9.5-13.2):(1-1.5); and / or The volatile solvent includes at least one of ethyl acetate, acetone and butanone.

3. The lamp surface composite coating according to claim 1, characterized in that: The particle size of the coating mixture is less than 30 μm.

4. The lamp surface composite coating according to claim 1, characterized in that: The modified nano-carbon spheres include nano-carbon spheres and a coupling agent, wherein the coupling agent includes at least one of 3-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, and methacryloxypropyltrimethoxysilane; and / or The filler also includes at least one of silicon carbide and graphene.

5. The lamp surface composite coating according to claim 1, characterized in that: The surface treatment agent includes at least one of silane coupling agents such as hexamethyldisilazane, hexamethylvinylsilazane, vinylethoxysilane, etc.; and / or The particle size of the nano carbon spheres is in the range of 60 to 200 nm; and / or The epoxy resin comprises at least one of bisphenol A epoxy resin, novolac epoxy resin and bisphenol A epoxy resin; and / or The organic solvent comprises at least one of propylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, ethylene glycol monobutyl ether, and dipropylene glycol methyl ether; and / or The leveling agent includes at least one of a polyether polyester modified organic siloxane and a phosphate modified acrylic leveling agent; and / or The dispersant includes sodium dodecyldibenzene disulfonate.

6. A method for preparing a composite coating for a lamp surface, characterized in that: Used to prepare the lamp surface composite coating according to any one of claims 1 to 5, the preparation method comprises the following steps: The epoxy resin is stirred at a first preset speed, and then after adding the filler, the organic solvent and the dispersant, the mixture is stirred at a second preset speed to obtain a dispersed mixed liquid, wherein the second preset speed is greater than the first preset speed; Adding the leveling agent into the dispersed mixed liquid, stirring at a third preset speed to obtain the ink mixture; The ink mixture and the modified inorganic matte powder are mixed and ground to obtain the coating mixture.

7. The method for preparing the composite coating for lamp surface according to claim 6, characterized in that: The first preset speed is 800-1000 rpm; and / or The second preset speed is 1800-2000 rpm; and / or The third preset rotation speed is 800-1000 rpm.

8. An LED module, characterized in that: It comprises a lamp board, lamp beads and a coating, wherein the coating is formed by applying the lamp surface composite coating according to any one of claims 1 to 5 on the surface of the lamp board, the lamp beads are arranged on the surface of the lamp board, the lamp surface composite coating covers the surface of the lamp board and fills the gap between the lamp beads and the lamp board.

9. The LED module according to claim 8, characterized in that: The lamp bead comprises a chip and a pin connected to the chip, one end of the pin away from the chip is connected to the surface of the lamp board, and the gap is formed between the chip and the lamp board; The thickness of the coating is greater than the distance from the bottom of the chip to the surface of the lamp board, so that the pins are covered in the coating.

10. A method for preparing an LED module, characterized in that: The LED module according to claim 8 is prepared by using the lamp surface composite coating according to any one of claims 1 to 5, and the preparation method of the LED module comprises the following steps: Spraying a volatile solvent on the surface of the lamp board so that the lamp board is wetted by the volatile solvent, and then spraying the coating mixture on the surface of the lamp board; or, mixing the coating mixture and the volatile solvent to obtain a lamp surface composite coating, and then spraying the lamp surface composite coating on the surface of the lamp board; The lamp board is dried until the volatile solvent is completely evaporated to obtain the LED module.

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