White ink and preparation method therefor, and backlight module

Abstract

A white ink and a preparation method therefor, and a backlight module. The white ink comprises a resin substrate and mica microsheets doped in the resin substrate. The high-temperature stability and reflectivity of the white ink are improved by doping into a resin substrate mica microsheets having a sheet structure.

Description

White ink, preparation method thereof and backlight module

[0001] The present application claims priority to the Chinese patent application No. 202410949976.7, filed on July 15, 2024, and entitled "White ink, preparation method thereof and backlight module", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of display technology, for example a white ink, a preparation method thereof and a backlight module. BACKGROUND

[0003] Compared with the current mainstream display technologies such as LCD and OLED, the mini-LED screen has advantages such as high brightness, long service life, high contrast, wide color gamut, and excellent light control.

[0004] Although the mini-LED display technology has many advantages and broad prospects, there are still some problems that need to be solved in a timely manner, such as high cost leading to high price, less than ideal response speed, and large amount of heat generated during operation.

[0005] The reflective layer used on the substrate of the mini-LED display device is mostly white ink. However, its reflectivity is low (≤85%), the light utilization efficiency is not high, and it needs to be exposed and developed in the process step, which increases the cost and process time. In the reliability verification, especially in the cold and hot impact process, peeling phenomenon occurs at the bonding site. In addition, a large amount of heat is generated during the operation of the mini-LED, which also challenges the heat resistance of the material.

[0006] The performance of the ink itself may differ between different manufacturers, and the thickness of the ink and the post-process (such as high-temperature baking) may affect the reflectivity, resulting in low reflectivity. At the same time, the raw materials of the white ink, such as the base resin material, pigment, filler, additive, and solvent, also have a great impact on the reliability of the formula.

[0007] Therefore, it is a research focus in the field to improve the reflectivity and high-temperature stability of white ink to meet the use requirements of the mini-LED screen.

[0008] SUMMARY

[0009] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0010] In order to improve the reflectivity and reliability of the white ink, the present application provides a white ink, a preparation method thereof and a backlight module. By doping mica micro-particles with a sheet structure in the resin base material, the high-temperature stability and reflectivity of the white ink are improved.

[0011] In a first aspect, the present application provides a white ink, comprising a resin base material and mica microflakes doped in the resin base material.

[0012] In the present application, the mica microflakes have a lamellar structure inside, are lamellar crystals, have the advantages of high-temperature resistance, insulation, acid and alkali corrosion resistance, and good gloss, and when the mica microflakes are doped in the resin base material of the white ink, the optical performance (reflectivity) of the white ink is higher, and the high-temperature stability is also improved.

[0013] In a second aspect, the present application provides a preparation method of the white ink according to the first aspect, comprising the following steps:

[0014] Mixing resin base material raw materials and mica microflakes, and curing to obtain the white ink.

[0015] In a third aspect, the present application further provides a backlight module, comprising a backlight substrate and a reflective layer formed by curing the white ink according to the first aspect.

[0016] Compared with the related art, the present application has the following beneficial effects:

[0017] In the present application, the mica microflakes have a lamellar structure inside, are lamellar crystals, have the advantages of high-temperature resistance, insulation, acid and alkali corrosion resistance, and good gloss, and when the mica microflakes are doped in the resin base material of the white ink, the optical performance (reflectivity) of the white ink is higher, and the high-temperature stability is also improved.

[0018] Other aspects can be apparent after reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the technical solutions of the present application, and constitute a part of the specification, and are used to explain the technical solutions of the present application together with the embodiments of the present application, and do not constitute a limitation on the technical solutions of the present application.

[0020] FIG. 1 is a structure schematic diagram of a cross-sectional view of the white ink provided by the embodiment 1 of the present application.

[0021] FIG. 2 is a structure schematic diagram of a cross-sectional view of the white ink provided by the embodiment 8 of the present application.

[0022] FIG. 3 is a structure schematic diagram of a cross-sectional view of the white ink provided by the embodiment 10 of the present application.

[0023] In the drawings, 1 is a resin base material, and 2 is a mica microflake. DETAILED DESCRIPTION

[0024] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application, and should not be regarded as specific limitations on the present application.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion.

[0026] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0027] One of the purposes of the present application is to provide a white ink, which comprises a resin base material and mica micro-particles doped in the resin base material.

[0028] It should be noted that the mica micro-particles in the present application can be directly purchased through the market channel.

[0029] In the present application, the mica micro-particles present a layered structure inside, are sheet crystal, have the advantages of high temperature resistance, insulation, acid and alkali corrosion resistance and good gloss, etc., and by doping them in the resin base material of the white ink, the optical performance (reflectivity) of the white ink will be significantly improved, and the high temperature stability will also be improved.

[0030] If the mica micro-powder, i.e. non-sheet structure, is doped in the resin base material, the above optimization effect cannot be achieved. Because the reflectivity of the nano-level mica micro-powder is slightly lower than that of titanium dioxide, and the micro-mirror structure cannot be realized in the base material.

[0031] In one embodiment,

[0032] The angle between the plane where the surface of the mica micro-particle is located and the first direction is α; wherein,

[0033] α≥45°, the first direction is perpendicular to the plane where the surface of the resin base material is located.

[0034] In the present application, the angle α between the plane where the surface of the mica micro-particle is located and the first direction is adjusted to be greater than or equal to 45°, so that the mica micro-particles in the resin base material are regularly oriented and arranged, forming a "micro-mirror" structure in the resin base material, so that the reflectivity of the white ink is higher, which can reach more than 95%.

[0035] Further, α = 90°, the angle between the mica micro-particle and the first direction is 90°, and the reflectivity of the white ink is higher.

[0036] In one embodiment,

[0037] In one embodiment,

[0038] N≥2, the first direction is perpendicular to the plane where the surface of the resin substrate is located, the first direction is parallel to the second direction, or the first direction intersects the second direction.

[0039] In the present application, the mica flakes are arranged in the same direction in the second direction, forming a same orientation distribution, and forming a "micro-mirror" structure in the resin substrate, and the optical performance (reflectivity) is significantly improved.

[0040] Further, the angle between the plane where the surface of each mica flake is located and the first direction is greater than or equal to 45°.

[0041] In one embodiment,

[0042] The surface of the mica flake further comprises a coating layer, and the coating layer comprises titanium dioxide particles.

[0043] In the present application, the titanium dioxide particles are coated on the surface of the mica flake, which not only has a whitening effect, but also improves the reflectivity of white ink.

[0044] In an optional embodiment, the average diameter of the titanium dioxide particles in the coating layer is 200-300 nm, such as 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm or 300 nm, but not limited to the listed values, and other values not listed in this range are also applicable.

[0045] In an optional embodiment, the titanium dioxide particles in the coating layer include anatase titanium dioxide particles and / or rutile titanium dioxide particles, and the rutile titanium dioxide particles are optional. Rutile titanium dioxide has excellent weather resistance and stability, and can work for a long time in harsh environments while maintaining high whiteness, and has a more obvious whitening effect in white ink.

[0046] In one embodiment, the thickness of the coating layer is 300-1000 nm, such as 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm or 1000 nm, but not limited to the listed values, and other values not listed in this range are also applicable.

[0047] In the present application, the thickness of the coating layer is in the range of 300-1000 nm, which can better achieve the excellent whitening effect on the mica flake; if the thickness of the coating layer is too thick, the orientation process will become difficult and the expected optical effect cannot be achieved, and the viscosity of the substrate will be large, affecting the final coating process; if the thickness of the coating layer is too thin, the final optical effect (reflectivity) will also be affected.

[0048] In one embodiment,

[0049] The mica flake comprises first mica flake and second mica flake, and the coating layer comprises first coating layer and second coating layer, the first coating layer corresponds to the first mica flake, and the second coating layer corresponds to the second mica flake; wherein,

[0050] The maximum length diameter of the first mica flake is different from that of the second mica flake, and / or the thickness of the first coating layer is different from that of the second coating layer.

[0051] In the present application, "corresponding" means that the first coating layer is located on the surface of the first mica flake, and the second coating layer is located on the surface of the second mica flake.

[0052] In the present application, by matching the first mica flake and the second mica flake with different maximum length diameters, the mica flake with larger size (i.e. the mica flake with relatively longer maximum length diameter) plays a leading role to form a reflection layer, and the mica flake with smaller size (i.e. the mica flake with relatively shorter maximum length diameter) fills into the gap to enhance the light utilization rate and reduce the light leakage phenomenon, thereby improving the reflectivity; if all are mica flake with larger size, it is inevitable to produce large gap and cause light leakage, which will lose the light utilization rate; on the contrary, if all are small size, it is easy to form agglomeration, which will also cause poor light effect; further, the mass ratio of the first mica flake to the second mica flake is 5:1-20:1, for example, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1 or 20:1, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0053] In an optional embodiment, the maximum length diameter of the first mica flake and the maximum length diameter of the second mica flake are each independently 1-10 μm, for example, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm, etc., but not limited to the listed values, other values not listed in the range are also applicable.

[0054] Specifically,

[0055] The maximum length diameter of the first mica flake is greater than the maximum length diameter of the second mica flake, and the thickness of the first coating layer is greater than the thickness of the second coating layer.

[0056] Or,

[0057] The maximum length diameter of the first mica flake is less than the maximum length diameter of the second mica flake, and the thickness of the first coating layer is greater than the thickness of the second coating layer.

[0058] In the present application, the first mica flake and the second mica flake with different length diameters are selected, and the thickness of the first coating layer corresponding to the first mica flake and the thickness of the second coating layer corresponding to the second mica flake are controlled, thereby improving the comprehensive effect of the orientation arrangement and the light utilization rate.

[0059] In one embodiment,

[0060] The coating layer further comprises zirconium dioxide particles, and / or

[0061] The surface of the coating layer further comprises a protective layer.

[0062] The protective layer comprises zirconium dioxide particles.

[0063] In an optional embodiment, the average diameter of the zirconium dioxide particles in the coating layer or the protective layer is 10-80 nm, for example, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, or 80 nm, etc., but is not limited to the listed values, and other values not listed in this range are also applicable.

[0064] In the present application, the coating layer further comprises zirconium dioxide particles, which cooperates with the titanium dioxide particles in the coating layer to further improve the refractive index of the white ink and reduce light loss. If the coating layer only contains titanium dioxide particles, particle agglomeration may occur, the dispersion effect is poor, and larger voids are formed in space, causing scattering and light leakage, resulting in reduced reflectivity. When the zirconium dioxide particles are further coated as a separate protective layer on the surface of the coating layer, the reliability and stability of the material are greatly improved without losing light efficiency.

[0065] In one embodiment,

[0066] The coating layer further comprises zirconium dioxide particles.

[0067] The zirconium dioxide particles are filled between the titanium dioxide particles; or,

[0068] The zirconium dioxide particles are filled in the mesopores of the titanium dioxide particles.

[0069] In the present application, the zirconium dioxide particles exist in a filling manner between the coated titanium dioxide particles or in the mesopores of the titanium dioxide particles, fill the gaps of the coating layer, reduce light loss, and improve the refractive index.

[0070] Further,

[0071] The filling amount of the zirconium dioxide particles in the coating layer is 10-20%, for example, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, etc., but not limited to the listed values, and other values not listed in this range are also applicable.

[0072] In the present application, if the filling amount of the zirconium dioxide particles in the coating layer is too high, exceeding 20%, the product surface hardness will be too high, and if the filling amount of the zirconium dioxide particles in the coating layer is too low, less than 10%, the coating layer will have too many gaps, affecting the light utilization rate.

[0073] In one embodiment,

[0074] The thickness of the protective layer is 50-100 nm, for example, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm, etc., but not limited to the listed values, and other values not listed in this range are also applicable.

[0075] In the present application, if the thickness of the protective layer is too thin, less than 50 nm, the coating effect is poor, which may result in a decrease in the scratch resistance of the material surface; if the thickness is too thick, exceeding 100 nm, although it improves stability and reliability, it will result in a loss of light efficiency.

[0076] In one embodiment,

[0077] The mica flakes include first mica flakes and second mica flakes, the coating layers include first coating layers and second coating layers, the protective layers include first protective layers and second protective layers, the first coating layers and the first protective layers correspond to the first mica flakes, and the second coating layers and the second protective layers correspond to the second mica flakes; wherein,

[0078] The difference between the thickness of the first coating layer of the first mica flakes and the thickness of the first protective layer is different from the difference between the thickness of the second coating layer of the second mica flakes and the thickness of the second protective layer.

[0079] In the present application, "corresponding" means that the first coating layer is located on the surface of the first mica flake, the first protective layer is coated on the surface of the first coating layer, the second coating layer is located on the surface of the second mica flake, and the second protective layer is coated on the surface of the second coating layer.

[0080] Specifically,

[0081] The maximum length diameter of the first mica flake is greater than that of the second mica flake, and the difference between the thickness of the first coating layer and the thickness of the first protective layer of the first mica flake is greater than the difference between the thickness of the second coating layer and the thickness of the second protective layer of the second mica flake.

[0082] Or,

[0083] The maximum length diameter of the first mica flake is less than that of the second mica flake, and the difference between the thickness of the first coating layer and the thickness of the first protective layer of the first mica flake is less than the difference between the thickness of the second coating layer and the thickness of the second protective layer of the second mica flake.

[0084] In the present application, the difference between the thickness of the coating layer and the thickness of the protective layer of the mica flake with a relatively larger maximum length diameter is relatively larger, achieving the purpose of reducing the difficulty in process preparation without affecting the overall light efficiency.

[0085] In one embodiment,

[0086] The resin substrate is further doped with titanium dioxide particles and / or zirconium dioxide particles.

[0087] In the present application, the resin substrate is doped with titanium dioxide particles (i.e., in addition to the doping of mica flake, titanium dioxide particles are also doped), so that the reflectivity of white ink is greatly improved; and the doping of zirconium dioxide particles in the resin substrate (i.e., in addition to the doping of mica flake, zirconium dioxide particles are also doped), plays a role in filling voids, achieving full utilization of light and reducing the loss of reflectivity.

[0088] In the present application, when titanium dioxide particles and zirconium dioxide particles are simultaneously doped in the resin substrate, the amount of titanium dioxide particles added is 50-70%, for example, 50%, 55%, 60%, 65% or 70%, etc., and the amount of zirconium dioxide particles added is 30-50%, for example, 30%, 35%, 40%, 45% or 50%, etc., but not limited to the listed values, other values not listed in this range are also applicable.

[0089] In one embodiment,

[0090] The resin substrate comprises a silicone resin substrate.

[0091] The white ink of the present application selects silicone resin as the base material. The silicon-oxygen bond of the silicone resin has high energy (443 Kj / mol), high heat resistance and mechanical properties, and excellent compatibility with other materials (such as mica flake, etc.), so that the white ink can work stably at high temperature for a long time without adverse effects, and has excellent reliability and stability.

[0092] It can be understood that, in addition to the silicone resin, the resin base material provided by the present application can also include other types of conventional resin base materials, such as polyester resin, etc.

[0093] The second object of the present application is to provide a preparation method of the white ink according to the first object,

[0094] The preparation method comprises the following steps:

[0095] Mixing the resin base material raw material and the mica flake, curing to obtain the white ink.

[0096] The preparation method provided by the present application is simple and easy to operate, does not require a complex preparation process, and is suitable for industrial application.

[0097] In one embodiment,

[0098] Before mixing, the mica flake is coated with a coating layer;

[0099] The coating layer comprises titanium dioxide particles.

[0100] In the present application, conventional methods that can achieve coating of titanium dioxide particles on mica flake are applicable, such as in-situ growth coating method or physical coating method, and the in-situ growth coating method can be selected.

[0101] Exemplarily, the present application provides a method for coating mica flake with titanium dioxide particles:

[0102] Titanium salt and mica flake to be coated are precipitated and coated in a solution, such as titanium tetrachloride and alkali method, organic acid titanium method, thermal hydrolysis method or buffer method, etc. Commonly used soluble titanium salts include titanium tetrachloride or titanyl sulfate, etc. Specific preparation parameters, etc. can be selected and adjusted by those skilled in the art according to actual needs.

[0103] Exemplarily, the present application takes the titanium tetrachloride and alkali method as an example. A proper amount of sodium hydroxide is dissolved in deionized water to prepare a 1 mol / L lye. Then, the prepared mixture of titanium tetrachloride and mica flake is gradually added to the lye, and the reaction rate and temperature should not be too high during this process. After the reaction is completed, the generated precipitate is washed with deionized water and placed in a vacuum oven for drying. Finally, the product can be obtained.

[0104] Further, in one embodiment,

[0105] The coating layer further comprises zirconium dioxide particles;

[0106] The zirconium dioxide particles are filled between the titanium dioxide particles; or,

[0107] The zirconium dioxide particles are filled in the mesopores of the titanium dioxide particles.

[0108] And / or, in one embodiment,

[0109] The coating layer is coated with a protective layer;

[0110] The protective layer comprises zirconium dioxide particles.

[0111] The preparation method of the zirconium dioxide particles is not particularly limited in the present application, and any method known within the scope of a person skilled in the art and applicable to the present application is applicable to the present application.

[0112] Exemplarily, the present application provides a method for filling zirconium dioxide particles in a coating layer:

[0113] A surfactant template method is provided to fill zirconium dioxide between titanium dioxide particles or in the mesopores of titanium dioxide particles; first, a suitable surfactant is selected and dissolved, then inorganic raw material titanium dioxide is added, and a sol or gel state is formed under certain conditions; an appropriate amount of zirconium dioxide particles is added to the formed sol or gel and subjected to hydrothermal reaction, and finally after cooling / filtering and drying, a preliminary mesoporous material is obtained, and then the surfactant template agent is removed by calcination or solvent extraction method.

[0114] The present application also provides a method for coating zirconium dioxide particles as a protective layer on the surface of the coating layer:

[0115] A sol-gel method is provided, in which titanium dioxide and zirconium dioxide are dissolved as precursor substances in a suitable solvent, and then by controlling conditions such as temperature and pH, the precursor solution undergoes hydrolysis and condensation to gradually form a sol, and as the reaction proceeds, the particles in the sol gradually aggregate to form a gel with a three-dimensional network structure. The gel is then heat treated to remove excess solvent and water, and the corresponding material is obtained.

[0116] In one embodiment,

[0117] Before solidification, the mica flake distribution orientation of the mixed gelatinous substance is adjusted, and the method for distribution orientation adjustment includes applying an electric field method or a natural leveling method.

[0118] Specifically,

[0119] The electric field parameter of the electric field application method includes: an electric field range of 0.01-1000 V / m, and a frequency range of 20-2000 Hz.

[0120] The preparation parameter of the natural leveling method includes: a leveling temperature of 60-70 °C, and a leveling time of 30-60 min.

[0121] In the present application, the specific preparation process of the electric field application method includes: applying an electric field in a first direction, and realizing the oriented arrangement of the mica flake in the resin base material by regulating the parameter of the electric field.

[0122] The specific preparation process of the natural leveling method includes: placing the mixed gelatinous substance in an oven to promote natural leveling by regulating the temperature and time, i.e. heating at 60 °C for 1 h, and realizing the oriented arrangement of the mica flake in the resin base material in the state of natural leveling.

[0123] In one embodiment, the resin base material raw material includes resin, coupling agent, catalyst, inhibitor, and curing agent.

[0124] The resin base material raw material further includes first particles and / or second particles; the first particles include titanium dioxide particles, and the second particles include zirconium dioxide particles.

[0125] In the present application, the types of the coupling agent, catalyst, inhibitor, and curing agent except for the resin are also selected according to the conventional technology; the person skilled in the art can select and adjust according to the actual needs.

[0126] In the optional embodiment, the coupling agent includes but is not limited to dimethyl di(chloroethane) silane, triethyl chlorosilane, methyl tri(vinyl dioxy) silane, etc.

[0127] In the optional embodiment, the catalyst includes but is not limited to platinum group metal catalyst, vinyl silane catalyst, epoxy resin catalyst, nitro compound catalyst, etc.

[0128] In the optional embodiment, the curing agent includes but is not limited to acid / alkali catalytic type organic silicon curing agent, alkyl type organic silicon curing agent, alcohol amine type organic silicon curing agent, ethyl silicate, etc.

[0129] In one embodiment,

[0130] The mixed raw material includes, in terms of weight parts:

[0131] For example, the weight fraction of the resin can be 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, or 60 parts, etc.; the weight fraction of the coupling agent can be 0.05 parts, 0.1 parts, 0.5 parts, 1 parts, 1.5 parts, or 2 parts, etc.; the weight fraction of the catalyst can be 0.05 parts, 0.1 parts, 0.5 parts, 1 parts, 1.5 parts, or 2 parts, etc.; the weight fraction of the inhibitor can be 0.01 parts, 0.05 parts, 0.1 parts, 0.5 parts, 1 parts, 1.5 parts, or 2 parts, etc.; the weight fraction of the curing agent can be 1 parts, 1.5 parts, 2 parts, 2.5 parts, or 3 parts, etc.; the weight fraction of the first particles and / or the second particles can be 0 parts, 1 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, or 15 parts, etc., but not limited to the listed values, and other values not listed in the range are also applicable.

[0132] It should be noted that in the preparation process of the specific embodiments, the weight fraction of the raw materials can be a single value or a range value, which does not affect the formation of the final product structure.

[0133] It can be understood that by adjusting the weight fraction of the mica microplate in the preparation raw materials, the purpose of enhancing the reflectivity of the material system is achieved; if the weight fraction of the mica microplate is too small, i.e., the amount of addition is too small, it is not conducive to improving the reflectivity; and if the weight fraction is too large, i.e., the amount of addition is too large, it will affect the orientation process of the mica microplate, and the material surface may become sticky and uneven.

[0134] The third purpose of the present application is to provide a backlight module, which comprises a backlight substrate and a reflective layer formed by curing the white ink according to the first purpose.

[0135] In the present application, the structures in the backlight module are conventional technical solutions except for the reflective layer.

[0136] Example 1

[0137] The present embodiment provides a white ink, as shown in FIG. 1, which comprises a resin substrate 1 (a silicone resin substrate) and mica microplates 2 (with a maximum length of 5 μm) doped in the silicone resin substrate.

[0138] The preparation method of the white ink is as follows:

[0139] The preparation raw materials are as follows in terms of weight fraction:

[0140] The above preparation raw materials are mixed in weight parts, and cured to obtain the white ink.

[0141] Example 2

[0142] The present embodiment provides a white ink, which comprises a silicone resin base material and mica microflakes (with a maximum length diameter of 1 μm) doped in the silicone resin base material.

[0143] The preparation method of the white ink is as follows:

[0144] The preparation raw materials are as follows in weight parts: The above preparation raw materials are mixed in weight parts, and cured to obtain the white ink.

[0145] Example 3

[0146] The present embodiment provides a white ink, which comprises a silicone resin base material and mica microflakes (with a maximum length diameter of 10 μm) doped in the silicone resin base material.

[0147] The preparation method of the white ink is as follows:

[0148] The preparation raw materials are as follows in weight parts:

[0149] The above preparation raw materials are mixed in weight parts, and cured to obtain the white ink.

[0150] Example 4

[0151] The difference between the present embodiment and Example 1 is that, in the preparation method of the present embodiment, the weight parts of the mica microflakes is 40 parts.

[0152] The rest of the preparation method and parameters remain the same as those of Example 1.

[0153] Example 5

[0154] The difference between the present embodiment and Example 1 is that, in the preparation method of the present embodiment, the weight parts of the mica microflakes is 5 parts.

[0155] The rest of the preparation method and parameters remain the same as those of Example 1.

[0156] Example 6

[0157] The difference between the present embodiment and Example 1 is that, in the present embodiment, the angle α between the plane where the surface of each mica microflake is located and the first direction is all ≥45°, and the first direction is perpendicular to the plane where the surface of the resin base material is located.

[0158]

[0159] The preparation method comprises the following steps:

[0160] The mixed gelatinous substance is applied with an electric field along the first direction, and the electric field parameters are as follows: the electric field range is 0.01-1000 V / m, and the frequency range is 20-2000 Hz, so that the mica flake is distributed and oriented in the silicone resin base material; then, curing is performed to obtain the white ink.

[0161] The remaining preparation method and parameters are consistent with those in Example 1.

[0162] Example 7

[0163] The difference between the present example and Example 1 is that the angle α between the plane where the surface of each mica flake is located and the first direction is all greater than or equal to 45° in the present example, and the first direction is perpendicular to the plane where the surface of the resin base material is located.

[0164] The preparation method comprises the following steps:

[0165] The mixed gelatinous substance is applied with an electric field along the first direction, and the electric field parameters are as follows: the electric field range is 0.01-1000 V / m, and the frequency range is 20-2000 Hz, so that the mica flake is distributed and oriented in the silicone resin base material; then, curing is performed to obtain the white ink.

[0166] Example 8

[0167] The difference between the present example and Example 1 is that, as shown in FIG. 2, the angle α between the plane where the surface of each mica flake is located and the first direction is all equal to 90° (i.e., the mica flake is arranged in a super-horizontal manner in the silicone resin base material) in the present example, and the first direction is perpendicular to the plane where the surface of the resin base material is located.

[0168] In the preparation method, the electric field parameters are adjusted as follows: the electric field range is 800-1500 V / m, and the frequency range is 1500-2000 Hz.

[0169] The remaining preparation method and parameters are consistent with those in Example 1.

[0170] Example 9

[0171] The difference between the present example and Example 1 is that the angle α between the plane where the surface of each mica flake is located and the first direction is all less than 45° in the present example.

[0172] In the preparation method, the electric field parameters are adjusted as follows: the electric field range is 0.01-100 V / m, and the frequency range is 10-100 Hz.

[0173] The remaining preparation method and parameters are consistent with those in Example 1.

[0174] Example 10

[0175] The difference between the embodiment and the embodiment 1 is that, as shown in Fig. 3, the mica flake surface of the embodiment includes a coating layer, and the coating particles in the coating layer are titanium dioxide particles (average particle size is 300 nm), and the thickness of the coating layer is 600 nm.

[0176] In the preparation method, the mica flake is first subjected to coating modification treatment, and the specific process is as follows:

[0177] 40 g of sodium hydroxide is dissolved in 1 L of deionized water to prepare a 1 mol / L lye, and then the prepared mixture of 20 g of titanium tetrachloride and 40 g of mica flake is gradually added to the lye. The reaction rate and temperature should not be too high, and the temperature is room temperature, and the time is 4 h. After the reaction is completed, the generated precipitate is washed with deionized water and placed in a vacuum oven for drying. Finally, the titanium dioxide coated and modified mica flake is obtained.

[0178] The titanium dioxide coated and modified mica flake is used as a raw material for preparation.

[0179] The rest of the preparation method and parameters remain the same as those of the embodiment 1.

[0180] In Fig. 3, the mica flake in the white ink is enlarged, and it can be seen that the surface is coated with titanium dioxide particles, forming a core-shell structure as shown on the right side of Fig. 10.

[0181] Embodiment 11

[0182] The difference between the embodiment and the embodiment 1 is that the embodiment includes first mica flake (maximum length diameter is 8 μm) and second mica flake (maximum length diameter is 3 μm), and the mass ratio of the first mica flake to the second mica flake is 5:1.

[0183] The surface of the first mica flake is coated with a first coating layer, and the coating particles in the first coating layer are titanium dioxide particles (average particle size is 300 nm), and the thickness of the first coating layer is 600 nm.

[0184] The surface of the second mica flake is coated with a second coating layer, and the coating particles in the second coating layer are titanium dioxide particles (average particle size is 300 nm), and the thickness of the second coating layer is 300 nm.

[0185] In the preparation method, the first mica flake and the second mica flake are subjected to coating modification treatment, specifically as follows: the same titanium tetrachloride and alkali method as in Example 10 is adopted; 20 g of sodium hydroxide is added to 200 mL of deionized water respectively and stirred uniformly until dissolved, the two alkali waters are named as A and B respectively, then 4 g of prepared titanium tetrachloride and 4 g of mixed solution of mica flake (first mica flake and second mica flake respectively) are slowly added to the alkali water A, 4 g of titanium tetrachloride and 8 g of mixed solution of mica flake are added to the alkali water B, the reaction rate and temperature are room temperature, and the time length is 5 h. After the reaction is completed, the generated precipitate is washed thoroughly, and dried in a vacuum oven at 120°C for 6 h, and finally the product is obtained.

[0186] The first mica flake and the second mica flake subjected to coating modification treatment are used as raw materials for preparation.

[0187] The rest of the preparation method and parameters remain the same as in Example 1.

[0188] Example 12

[0189] The difference between this example and Example 11 is that this example contains only the first mica flake.

[0190] The rest of the preparation method and parameters remain the same as in Example 11.

[0191] Example 13

[0192] The difference between this example and Example 11 is that this example contains only the second mica flake.

[0193] The rest of the preparation method and parameters remain the same as in Example 11.

[0194] Example 14

[0195] The difference between this example and Example 1 is that the surface of the mica flake in this example is coated with a coating layer, the coating particles in the coating layer are titanium dioxide particles (average particle size of 300 nm) and zirconium dioxide particles (average particle size of 30 nm, filling amount of 15%) filled in the mesopores of the titanium dioxide particles, and the thickness of the coating layer is 600 nm.

[0196] In the preparation method, the mica flake is first coated and modified, and the specific steps are as follows: the mesoporous material containing titanium dioxide and zirconium dioxide filled in the mesoporous material of titanium dioxide is prepared by using the template method or the sol-gel method; then, the coating layer is prepared by using the same method as that in Example 10; the specific steps are as follows: 10 g of long-chain alkyl quaternary ammonium salt is selected as a surfactant and dissolved in 200 mL of deionized water, then 15 g of inorganic raw material titanium dioxide is added, and after being heated at 60 ℃ for 8 h, a sol or gel state is formed; 7 g of zirconium dioxide particles are added to the formed sol or gel and subjected to hydrothermal reaction, and finally the preliminary mesoporous material is obtained after cooling / filtering and drying; then, the surfactant template is removed by calcination or solvent extraction.

[0197] Then, 40 g of sodium hydroxide is dissolved in 1 L of deionized water to prepare a 1 mol / L lye, and then the prepared mesoporous material and 40 g of mica flake mixture are gradually added to the lye, and the reaction rate and temperature should not be too high, the temperature is room temperature, and the time is 5 h. After the reaction is completed, the generated precipitate is washed with deionized water and placed in a vacuum oven for drying, and finally the product is obtained.

[0198] The coated and modified mica flake is used as a raw material for preparation.

[0199] The remaining preparation method and parameters remain the same as those in Example 1.

[0200] Example 15

[0201] The difference between this example and Example 1 is that in this example, the surface of the mica flake is coated with a coating layer, and the surface of the coating layer is coated with a protective layer; the coating particles in the coating layer are titanium dioxide particles (with an average particle size of 300 nm), and the thickness of the coating layer is 600 nm; the coating particles in the protective layer are zirconium dioxide particles (with an average particle size of 80 nm), and the thickness of the protective layer is 80 nm.

[0202] In the preparation method, the mica flake is first coated with a coating layer and a protective layer, and the specific steps are as follows: first, 20 g of mica slurry is heated to 70-80 ℃, and an appropriate amount of lye is added under uniform stirring, and the pH is controlled at 12-12.5; then, 20 g of titanium salt (titanium tetrachloride) is gradually added, and after sufficient reaction (6 h), hydrated titanium dioxide is deposited on the surface of the mica flake; after filtration, drying and calcination at a high temperature of 900 ℃ for 2 h, the target product is obtained. Then, the zirconium dioxide can be coated on the surface of the mica flake by using the hydrothermal method, and the specific steps are as follows: 50 g of mica slurry is taken and the temperature is controlled at 70-80 ℃, then 10 g of zirconium nitrate or zirconium sulfate is added, and boiling reflux is maintained for about 1 h; after filtration, water washing and drying, the target product is obtained by heating to 950 ℃ for calcination for half an hour.

[0203] The processed mica flake is used as a raw material for preparation.

[0204] The remaining preparation method and parameters are consistent with those of Example 1.

[0205] Example 16

[0206] The difference between this example and Example 1 is that the first mica flake (with a maximum length diameter of 8 μm) and the second mica flake (with a maximum length diameter of 3 μm) are included in this example, and the mass ratio of the first mica flake to the second mica flake is 10:1 to 3:1.

[0207] The surface of the first mica flake is sequentially coated with a first coating layer and a first protective layer from the inside to the outside, the coated particles of the first coating layer are titanium dioxide particles (with an average particle size of 200 nm), the thickness of the first coating layer is 600 nm, the coated particles of the first protective layer are zirconium dioxide particles (with an average particle size of 80 nm), and the thickness of the first protective layer is 100 nm.

[0208] The surface of the second mica flake is sequentially coated with a second coating layer and a second protective layer from the inside to the outside, the coated particles of the second coating layer are titanium dioxide particles (with an average particle size of 200 nm), the thickness of the second coating layer is 300 nm, the coated particles of the second protective layer are zirconium dioxide particles (with an average particle size of 30 nm), and the thickness of the second protective layer is 40 nm.

[0209] In the preparation method, the first mica flake and the second mica flake are first subjected to coating modification treatment, and the specific coating operation steps are as follows: see the above-mentioned Example 15.

[0210] Coating modification of the first mica flake: the mica flake is first subjected to coating layer coating and protective layer coating treatment, 50 g of mica slurry is heated to 70-80°C, an appropriate amount of alkali solution is added under uniform stirring, the pH is controlled to be 12-12.5, then 40 g of titanium salt (titanium tetrachloride) is gradually added, after sufficient reaction (6 h), hydrated titanium dioxide is deposited on the surface of the mica flake, and after filtration, drying and calcination at a high temperature of 900°C for 2 h, the target product (first coating layer) is obtained. Then, 50 g of mica original slurry is heated to 70-80°C, then 10 g of zirconium nitrate or zirconium sulfate is added, boiling reflux is maintained for about 1 h, then after filtration, water drying and heating to 950°C calcination for half an hour, the target product (first protective layer) is prepared.

[0211] The coating modification of the second mica flake is as follows: the mica flake is coated with a coating layer and a protective layer. First, 50 g of mica slurry is heated to 70-80°C, and an appropriate amount of alkali solution is added under uniform stirring, with the pH controlled at 12-12.5. Then, 20 g of titanium salt (titanium tetrachloride) is gradually added, and after sufficient reaction (6 h), hydrated titanium dioxide is deposited on the surface of the mica flake. After filtration, drying, and calcination at 900°C for 2 h, the target product (second coating layer) is obtained. Then, 50 g of mica slurry is heated to 70-80°C, and 4 g of zirconium nitrate or zirconium sulfate is added. Boiling reflux is maintained for about 1 h, and then the target product (second protective layer) is obtained after filtration, water-based drying, and heating to 950°C for calcination for half an hour.

[0212] The first mica flake and the second mica flake after coating modification are used as raw materials for preparation.

[0213] The remaining preparation methods and parameters are consistent with those of Example 1.

[0214] Example 17

[0215] The difference between this example and Example 1 is that the silicone resin substrate in this example is also doped with titanium dioxide particles (with an average particle size of 500 nm).

[0216] In the preparation method, the raw materials are mixed in the following proportions by weight:

[0217] The above raw materials are mixed in the proportions by weight, and the white ink is obtained after curing.

[0218] Example 18

[0219] The difference between this example and Example 1 is that the silicone resin substrate in this example is also doped with zirconium dioxide particles (with an average particle size of 20 nm).

[0220] In the preparation method, the raw materials are mixed in the following proportions by weight:

[0221] The above raw materials are mixed in the proportions by weight, and the white ink is obtained after curing.

[0222] Example 19

[0223] The difference between this example and Example 1 is that the silicone resin substrate in this example is also doped with titanium dioxide particles (with an average particle size of 100 nm) and zirconium dioxide particles (with an average particle size of 50 nm).

[0224] The mass percentage of the titanium dioxide particles is 60%, and the mass percentage of the zirconium dioxide particles is 40%, based on the total mass of the titanium dioxide particles and the zirconium dioxide particles being 100%.

[0225] In the preparation method, the preparation raw materials are as follows in terms of weight parts:

[0226] The white ink is obtained by mixing and solidifying the preparation raw materials in the above weight parts.

[0227] Comparative Example 1

[0228] The difference between the present comparative example and Example 1 is that the white ink provided in the present comparative example does not contain mica flakes.

[0229] In the preparation method, no mica flakes are added to the preparation raw materials.

[0230] The remaining preparation method and parameters are consistent with those of Example 1.

[0231] [Performance Test]

[0232] The white inks provided in Examples 1-19 and Comparative Example 1 are subjected to performance tests:

[0233] (a) Reflectance: The reflectance value of the white ink coating is tested by using a Konica Minolta CM-3600A spectrophotometer;

[0234] (b) Whiteness value: The whiteness value of the white ink coating is tested by using a Shanghai Yuefeng SBDY-3 whiteness meter;

[0235] (c) Yellowing resistance: After the cured white ink sample is placed in an oven at 200℃ for 5 minutes, the reflectance is tested by using a Konica Minolta CM-3600A spectrophotometer, and the yellowing resistance is evaluated by the change in the reflectance value.

[0236] The test results of Examples 1-5 and Comparative Example 1 are shown in Table 1.

[0237] Table 1

[0238] From Table 1, it can be seen that:

[0239] From the data results of Example 1 and Examples 4 and 5, it can be seen that if the amount of mica flakes added in the white ink is too much, the light reflection performance of the material will be affected, and if the amount of mica flakes added is too little, the reflectance will decrease.

[0240] From the data results of Example 1 and Comparative Example 1, it can be seen that the present application significantly improves the whiteness value and yellowing resistance of the material by doping mica flakes in the white ink.

[0241] The test results of Example 1 and Examples 6-9 and Comparative Example 1 are shown in Table 2.

[0242] Table 2

[0243] From Table 2, it can be seen that:

[0244] From the data results of Example 1 and Examples 6-9, it can be seen that the mica flakes in the resin substrate are distributed in an oriented manner, effectively improving the utilization of light, and thus greatly improving the reflectivity; and the angle a between the plane in which each mica flake surface lies and the first direction is ≥45°, which can better achieve the utilization of light and reduce light loss.

[0245] The test results of Example 1 and Examples 10-16 and Comparative Example 1 are shown in Table 3.

[0246] Table 3

[0247] From Table 3, it can be seen that:

[0248] From the data results of Example 1 and Example 10, it can be seen that the mica flake surface is coated with a titanium dioxide particle coating layer, which not only has a whitening effect but also improves the reflectivity of the material.

[0249] From the data results of Example 1, Examples 11-13, it can be seen that in the present application, different sizes of mica flakes are mixed and doped, the larger size mica flakes play a dominant role in forming a reflection layer, and the smaller size mica flakes fill into the voids to enhance the utilization of light and reduce light leakage, thereby improving the reflectivity; while only large size mica flakes are used, it is inevitable that large voids will be produced, causing light leakage and reducing the utilization of light; while both are small size mica flakes, they are prone to agglomeration, also causing poor light efficiency.

[0250] From the data results of Example 10 and Examples 14-16, it can be seen that the mica flake surface is only coated with titanium dioxide particles, which may cause particle agglomeration, forming larger voids in the coating layer, causing scattering and light leakage, resulting in limited improvement in reflectivity; while the zirconium dioxide particles are filled or coated as a separate protective layer, the utilization of light is improved, light loss is avoided, and the reflectivity is significantly improved.

[0251] The data results of Example 1 and Examples 17-19 and Comparative Example 1 are shown in Table 4.

[0252] Table 4

[0253] From Table 4, it can be seen that:

[0254] From the data results of Example 1 and Examples 17-19, it can be seen that, in addition to the mica flake doping, the further doping of titanium dioxide particles and / or zirconium dioxide particles in the resin substrate of the present application improves the reflectivity and heat resistance while whitening.

[0255] In summary, in the present application, the mica flake has a layered structure inside, which is a lamellar crystal, has the advantages of high temperature resistance, insulation, acid and alkali corrosion resistance and good gloss, and when it is doped in the resin substrate of the white ink, the optical performance (reflectivity) of the white ink is obviously improved, and the high temperature stability is also improved; further, by orienting the distribution of the mica flake, or by surface modification treatment of the mica flake, or by adding doping particles in the resin substrate, the light utilization is improved, the light loss is reduced, the reflectivity of the white ink is greatly improved, and the whitening effect is also achieved.

[0256] The applicant declares that the above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and those skilled in the art should understand that any changes or replacements within the technical scope disclosed by the present application, which can be easily thought of by any person skilled in the art, falls within the protection scope and disclosure scope of the present application.

Claims

1. A white ink, comprising a resin base material and mica flakes doped in the resin base material. 2.The white ink according to claim 1, wherein, an angle between a plane where a surface of the mica flakes locates and a first direction is α; wherein, α ≥ 45°, and the first direction is perpendicular to a plane where a surface of the resin base material locates. 3.The white ink according to claim 2, wherein, the angle α is 45°. 4.The white ink according to claim 1, wherein, N mica flakes are arranged adjacently in a second direction, and an angle between a plane where a surface of each of the mica flakes locates and a first direction is the same; wherein, N ≥ 2, the first direction is perpendicular to a plane where a surface of the resin base material locates, the first direction is parallel to the second direction, or the first direction intersects with the second direction. 5.The white ink according to claim 4, wherein, the angle between the plane where the surface of each of the mica flakes locates and the first direction is greater than or equal to 45°. α＝90°。 6.The white ink according to claim 1, wherein, the surface of the mica flakes further comprises a coating layer, and the coating layer comprises titanium dioxide particles. 7.The white ink according to claim 6, wherein, a thickness of the coating layer is 300-1000 nm. 8.The white ink according to claim 6, wherein, the mica flakes comprise first mica flakes and second mica flakes, the coating layer comprises first coating layers and second coating layers, the first coating layers correspond to the first mica flakes, and the second coating layers correspond to the second mica flakes; wherein, a maximum length diameter of the first mica flakes is different from a maximum length diameter of the second mica flakes, and / or a thickness of the first coating layers is different from a thickness of the second coating layers. 9.The white ink according to claim 8, wherein, the maximum length diameter of the first mica flakes is greater than the maximum length diameter of the second mica flakes, and the thickness of the first coating layers is greater than the thickness of the second coating layers. 10.The white ink according to claim 8, wherein, the maximum length diameter of the first mica flakes is less than the maximum length diameter of the second mica flakes, and the thickness of the first coating layers is greater than the thickness of the second coating layers. 11.The white ink according to claim 6, wherein, the coating layer further comprises zirconium dioxide particles, and / or a surface of the coating layer further comprises a protective layer; and the protective layer comprises zirconium dioxide particles. 12.The white ink according to claim 11, wherein, the coating layer further comprises zirconium dioxide particles; the zirconium dioxide particles are filled between the titanium dioxide particles; or the zirconium dioxide particles are filled in mesopores of the titanium dioxide particles. 13.The white ink according to claim 12, wherein, a filling amount of the zirconium dioxide particles in the coating layer is 10-20%. 14.The white ink according to claim 11, wherein, a thickness of the protective layer is 50-100 nm. 15.The white ink according to claim 11, wherein, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The mica flake includes a first mica flake and a second mica flake, the coating layer includes a first coating layer and a second coating layer, the protective layer includes a first protective layer and a second protective layer, the first coating layer and the first protective layer correspond to the first mica flake, the second coating layer and the second protective layer correspond to the second mica flake; wherein, The difference between the thickness of the first coating layer and the thickness of the first protective layer of the first mica flake is different from the difference between the thickness of the second coating layer and the thickness of the second protective layer of the second mica flake.

16. The white ink according to claim 15, wherein, The maximum length diameter of the first mica flake is greater than the maximum length diameter of the second mica flake, and the difference between the thickness of the first coating layer and the thickness of the first protective layer of the first mica flake is greater than the difference between the thickness of the second coating layer and the thickness of the second protective layer of the second mica flake.

17. The white ink according to claim 15, wherein, The maximum length diameter of the first mica flake is less than the maximum length diameter of the second mica flake, and the difference between the thickness of the first coating layer and the thickness of the first protective layer of the first mica flake is less than the difference between the thickness of the second coating layer and the thickness of the second protective layer of the second mica flake.

18. The white ink according to claim 1, wherein, The resin base material is further doped with titanium dioxide particles and / or zirconium dioxide particles.

19. The white ink according to claim 1, wherein, The resin base material includes a silicone resin base material.

20. A preparation method of the white ink according to any one of claims 1-19, comprising the following steps: Mixing resin base material raw materials and mica flake, curing to obtain the white ink.

21. The preparation method according to claim 20, wherein, Before the mixing, the mica flake is coated with a coating layer; The coating layer includes titanium dioxide particles.

22. The preparation method according to claim 21, wherein, The coating layer further includes zirconium dioxide particles; The zirconium dioxide particles are filled between the titanium dioxide particles; or, The zirconium dioxide particles are filled in the mesopores of the titanium dioxide particles.

23. The preparation method according to claim 21, wherein, The coating layer is coated with a protective layer; The protective layer includes zirconium dioxide particles.

24. The preparation method according to claim 20, wherein, Before the curing, the mixed gelatinous substance is subjected to mica flake distribution orientation adjustment, and the distribution orientation adjustment method includes an electric field application method or a natural leveling method. The electric field parameter of the electric field application method includes an electric field range of 0.01-1000 V / m and a frequency range of 20-2000 Hz; 25. The method of manufacturing according to claim 24, wherein, The preparation parameter of the natural leveling method includes a leveling temperature of 60-70 °C and a leveling time of 30-60 min. The resin base material raw materials include resin, coupling agent, catalyst, inhibitor and curing agent; 26. The method of manufacturing according to claim 20, wherein, The resin base material raw materials further include first particles and / or second particles; the first particles include titanium dioxide particles, and the second particles include zirconium dioxide particles. ​ 27. The method of manufacturing according to claim 20, wherein, The mixed raw materials include, by weight parts:

28. A backlight module, comprising: The backlight module comprises a backlight substrate and a reflective layer formed by curing the white ink according to any one of claims 1-19.

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