Preparation method of colorful film and shell

Abstract

This disclosure relates to a method for preparing a dazzling film and its housing. The method comprises depositing a brightness-enhancing film having a first color on a target substrate; then coating the brightness-enhancing film with ink having a second color to form a target color, wherein the second color has the same hue as the target color. This disclosed technical solution effectively addresses the high dependency risk associated with conventional dazzling films.

Description

Technical Field

[0001] The present disclosure relates to the technical field of thin film materials, and in particular to a preparation method and a shell of a colorful thin film. Background Art

[0002] With the widespread adoption of electronic products, consumers' demands for visual effects and appearance are gradually increasing. Related technologies generally employ stacking of plating film layers to achieve a dazzling color effect. The greater the total thickness of the plating film, the better the dazzling effect. However, as the thickness of the plating film increases, the reliability risks of the plating film, such as film cracking and UV plating loss, also increase. Summary of the Invention

[0003] The present disclosure provides a preparation method and shell of a colorful film to solve the technical problem of high risk of dependence of traditional colorful films.

[0004] To this end, in a first aspect, a method for preparing a colorful film comprises:

[0005] depositing a brightness enhancing film having a first color on a target substrate;

[0006] The brightness enhancement film is covered with ink having a second color to form a target color, wherein the second color and the target color have the same hue.

[0007] In a possible implementation, the L value of the first color is less than or equal to 60, the a value of the first color is -10 to 10, and the b value of the first color is -10 to 10.

[0008] In one possible implementation, the color difference between the second color and the target color is:

[0009] When the second color is the first color system, the L difference between the second color and the target color is ΔL, the a difference between the second color and the target color is Δa, and the b difference between the second color and the target color is Δb, where ΔL≤0.3, Δa≤0.1, and Δb≤0.15;

[0010] When the second color is a second color system, the L difference between the second color and the target color is ΔL, the a difference between the second color and the target color is Δa, and the b difference between the second color and the target color is Δb, where ΔL≤0.7, Δa≤1.2, and Δb≤0.5;

[0011] The color saturation of the second color system is higher than the color saturation of the first color system.

[0012] In one possible embodiment, depositing a brightness enhancing film having a first color on a target substrate includes: alternately depositing a first refractive index material layer and a second refractive index material layer on the target substrate so that the thickness of the brightness enhancing film is 10 nm to 300 nm; wherein the refractive index of the first refractive index material layer is greater than the refractive index of the second refractive index material layer.

[0013] In a possible implementation, the first refractive index material layer is provided with three layers, the second refractive index material layer is provided with two layers, and depositing a brightness enhancement film having a first color on a target substrate includes:

[0014] Depositing a first refractive index material layer with a thickness of 23 nm to 26 nm on a target substrate;

[0015] Depositing a second refractive index material layer with a thickness of 12 nm to 15 nm on a side of the first refractive index material layer away from the target substrate;

[0016] Depositing a first refractive index material layer with a thickness of 53 nm to 59 nm on a side of the second refractive index material layer away from the target substrate;

[0017] Depositing a second refractive index material layer with a thickness of 43 nm to 49 nm on a side of the first refractive index material layer away from the target substrate;

[0018] A first refractive index material layer with a thickness of 57 nm to 64 nm is deposited on a side of the second refractive index material layer away from the target substrate.

[0019] In a possible embodiment, the first refractive index material layer is provided with two layers, the second refractive index material layer is provided with one layer, and depositing a brightness enhancement film having a first color on the target substrate includes:

[0020] Depositing a first refractive index material layer with a thickness of 6 nm to 9 nm on a target substrate;

[0021] Depositing a second refractive index material layer with a thickness of 27 nm to 37 nm on a side of the first refractive index material layer away from the target substrate;

[0022] A first refractive index material layer with a thickness of 36 nm to 49 nm is deposited on a side of the second refractive index material layer away from the target substrate.

[0023] In one possible embodiment, the material of the first refractive index material layer is any one of Nb2O5, Ti3O5 or Si3N4; and / or the material of the second refractive index material layer is any one of SiO2, MgF2 or Al2O3

[0024] In a possible implementation, the thickness of the ink having the second color is 15 μm to 30 μm.

[0025] In one possible embodiment, the method for preparing the ink having the second color includes:

[0026] A plurality of inks of different hues are stirred and mixed to obtain ink having a second color.

[0027] In a second aspect, the present disclosure further provides a shell, the outer surface of which is provided with a colorful film, and the colorful film is prepared by the method for preparing the colorful film as described above.

[0028] According to the preparation method and shell of the colorful film provided by the present disclosure, the preparation method of the colorful film includes: depositing a brightness enhancement film having a first color on a target substrate; covering the brightening film with ink having a second color to form a target color, and the second color has the same hue as the target color. Compared with the traditional colorful film that uses a colorful film system and a white oil cover to superimpose to achieve a colorful effect, the technical solution disclosed in the present disclosure proposes a preparation method of a colorful film that uses a brightening film and a colored ink to superimpose to achieve a colorful effect. This preparation method avoids the traditional preparation of colorful films that increases the thickness of the colorful film system to improve the colorful effect, and the increase in the thickness of the colorful film system brings reliability risks such as film cracking to the entire colorful film, and the colorful film prepared by this preparation method has a good colorful effect, a high appearance yield, and excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without inventive work. In addition, in the drawings, the same reference numerals are used for the same components, and the drawings are not drawn to scale.

[0030] Figure 1 A flowchart of the preparation process of the colorful film provided by the present disclosure;

[0031] Figure 2 A flowchart of the preparation process of the brightness enhancement film provided by the present disclosure;

[0032] Figure 3 A flowchart of the preparation process of the first colorful film provided by the present invention;

[0033] Figure 4 A flowchart of the preparation process of the second colorful film provided by the present disclosure;

[0034] Figure 5 Schematic diagram of the color synthesis of the purple colorful film prepared by the traditional method;

[0035] Figure 6 for Figure 5The performance test results of the obtained purple colorful film;

[0036] Figure 7 Schematic diagram of the color synthesis of the first purple dazzling film provided by the present disclosure;

[0037] Figure 8 A schematic diagram of the color synthesis of the second purple dazzling film provided by the present invention;

[0038] Figure 9 The Lab curves of traditional colorful films at different wavelengths are shown below.

[0039] Figure 10 The Lab change curve of the brightening film at different wavelengths;

[0040] Figure 11 Based on Figure 9 and Figure 10 Comparison table made by curve changes;

[0041] Figure 12 A schematic diagram of the color synthesis of a purple colorful film prepared according to the preparation method provided by the present disclosure;

[0042] Figure 13 Schematic diagram of the color synthesis of a light gray colorful film prepared according to the preparation method provided by the present disclosure. DETAILED DESCRIPTION

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present disclosure without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0044] The preparation of traditional colorful films usually involves electroplating a colorful film system with a colorful effect on a substrate first, and then covering the colorful film system with white ink or black ink to adjust the colorful color on the colorful film system through the white ink or black ink on the bottom cover, so that the entire colorful film can achieve the final target colorful color effect. To meet or improve the colorful effect of the colorful film, it is necessary to increase the thickness of the colorful film system. However, as the thickness of the colorful film system increases, the risk of dependence of the colorful film also increases, such as the probability of film cracking / UV plating off increases; and, the increase in the thickness of the colorful film system will prolong the film formation time of the colorful film system, which increases the probability of poor appearance; and the increase in the thickness of the colorful film system will also increase the electroplating consumables, increasing the production cost of the colorful film system. Figure 5The figure shows the color synthesis diagram of the purple colorful film prepared by the traditional method, which uses the colorful film system (yellow-green) and the white oil cover to achieve the purple colorful effect. Figure 6 This is the test result of purple colorful film. Figure 6 It can be seen that the purple colorful film prepared by traditional methods has dependent risks such as film cracking and UV plating loss in the 100-grid test.

[0045] Based on the above-mentioned traditional method for preparing colorful films, a method for preparing colorful films is proposed, which reduces the thickness of the colorful film system to reduce the colorful effect of the colorful film system, and then covers the colorful film system with colored ink to make the entire colorful film achieve the ultimate colorful color effect. Figure 7 As shown, in order to reduce the colorful effect of the colorful film (the yellow-green saturation is reduced and approaches light yellow-green), it is covered with white ink to obtain a pink colorful effect, but cannot achieve a purple colorful effect. Figure 8 As shown in the figure, after reducing the colorful effect of the colorful film system (the yellow-green saturation is reduced and approaches light yellow-green), it is covered with colored ink (purple-red ink, which has the same hue as purple), and the entire colorful film achieves the final purple colorful effect. However, in actual preparation, there are two adjustment factors, one is the adjustment of the shallow colorful effect of the colorful film system (the colorful effect after reduction), and the other is the adjustment of the color of the colored ink. Figure 9 As shown, in the adjustment of the colorful effect of the colorful film system, since the colorful film system is greatly affected by the wavelength of light, the colorful color of the colorful film changes greatly. Therefore, the shallow colorful effect (the reduced colorful effect) of the colorful film system is difficult to control.

[0046] It should be explained that UV plating loss means that in the UV test, when the product exposed to ultraviolet light undergoes a hundred-grid test or a strong stripping test, its film adhesion is low / poor.

[0047] Based on this, Figure 1 As shown, the embodiment of the present disclosure provides a method for preparing a colorful film, comprising:

[0048] Step S1: depositing a brightness enhancement film having a first color on a target substrate;

[0049] Step S2: Covering the brightness enhancement film with ink having a second color to form a target color, wherein the second color and the target color have the same hue.

[0050] In this embodiment, a brightening film is used directly to increase light transmittance, rather than a dazzling film. The brightening film is then covered with colored ink, resulting in the entire film achieving the desired dazzling effect. In this preparation method, the brightening film provides a transparent or very light color, while the primary hue of the dazzling film is provided by the colored ink. Therefore, the ink color has certain requirements: the secondary color of the ink must be the same hue as the target color. In this way, thanks to the brightening film's strong light transmittance, strong light passes through the colored ink, allowing the film to achieve a dazzling effect. Furthermore, the harmony between the brightening film's transparent or very light color and the colored ink achieves the target color.

[0051] In one example, Figure 12 Shown is a schematic diagram of the color synthesis of a purple colorful film prepared according to the preparation method provided by the present disclosure, Figure 13 This is a schematic diagram of the color synthesis of a light gray colorful film prepared according to the preparation method provided by the present disclosure. It can be seen that the preparation method proposed in this embodiment, which utilizes the superposition of a brightness enhancement film and a colored ink, can achieve a colorful effect of the target color. Moreover, this preparation method avoids the traditional method of increasing the thickness of the colorful film system to enhance the colorful effect, which brings reliability risks such as film cracking to the entire colorful film. At the same time, it also avoids the problem of difficulty in controlling the colorful effect reduced by the colorful film system in the preparation method of superposing a colorful film system with colored ink. Overall, the colorful film prepared by this preparation method has a good colorful effect, a high appearance yield, and excellent performance.

[0052] like Figure 10 and 11 As shown, the wavelength of light has a smaller effect on the brightness enhancement film than on the color film system. Under the same wavelength change, the b-value change of the color film system is significantly greater than that of the brightness enhancement film. Therefore, the color film system is greatly affected by light, while the brightness enhancement film is less affected by light. Thus, this embodiment achieves the dazzling effect of the color film by coating the brightness enhancement film with colored ink. This shifts the industry's difficulty to controlling the ink color and the color of the combined ink and brightness enhancement film, avoiding the need to adjust the color effect of the color film, greatly reducing the difficulty of preparing the color film, and facilitating the industrial production of the color film.

[0053] In one example, the preparation method of the colorful film proposed in the present disclosure can be achieved by a magnetron sputtering coating process. Specifically, first, a standard working gas (argon, etc.) and a reaction gas (oxygen, etc.) are filled into the magnetron sputtering coating machine, and the air pressure in the magnetron sputtering coating machine is maintained at 0.3Pa to 0.4Pa; then, a suitable target substrate is selected first, and the target substrate is placed into the magnetron sputtering coating machine; the niobium target is turned on, and the target current and deposition time are controlled to control the thickness of the brightening film. Of course, in other examples, the provision of a brightening film on the target substrate can also be achieved by other means, such as by chemical liquid deposition (CLD) or chemical vapor deposition (CVD), etc., which will not be elaborated here.

[0054] In one example, the ink may be coated on the brightness enhancement film by screen printing or spraying.

[0055] In a specific example, the first color on the brightness enhancement film is light yellow, and the second color of the ink is purple-red. Thus, by covering the light yellow brightness enhancement film with purple-red ink, a purple dazzling effect can be obtained.

[0056] In another specific example, the first color on the brightness enhancement film is transparent, and the second color of the ink is gray. Thus, by covering the transparent brightness enhancement film with gray ink, a light gray dazzling effect can be obtained.

[0057] In another specific example, the first color on the brightness enhancement film can also be transparent, and the second color of the ink can be light yellow. In this way, by covering the transparent brightness enhancement film with light yellow ink, a khaki color dazzling effect can be obtained.

[0058] Of course, in other specific embodiments, the first color of the brightness enhancing film may be a light color, and the second color of the ink may be blue. Thus, by covering the light-colored brightness enhancing film with blue ink, a light blue dazzling effect may be obtained.

[0059] In some embodiments, the L value of the first color is less than or equal to 60, the a value of the first color is -10 to 10, and the b value of the first color is -10 to 10.

[0060] In this embodiment, the Lab value of the first color of the brightness enhancement film is optimized to reduce the film's peak fluctuations and mitigate the adverse effects of light wavelength on the film. This reduces the fluctuations of the first color, and further reduces the first color's interference with the second color, ensuring that the target color is achieved when the first color is superimposed with the ink of the second color. Thus, by controlling the stability of the first color, the synergistic effect of the first color on the second color is effectively enhanced, making the acquisition of the target color faster and simpler.

[0061] In some embodiments, the color difference between the second color and the target color is:

[0062] When the second color is the first color system, the L difference between the second color and the target color is ΔL, the a difference between the second color and the target color is Δa, and the b difference between the second color and the target color is Δb, where ΔL≤0.3, Δa≤0.1, and Δb≤0.15;

[0063] When the second color is a second color system, the L difference between the second color and the target color is ΔL, the a difference between the second color and the target color is Δa, and the b difference between the second color and the target color is Δb, where ΔL≤0.7, Δa≤1.2, and Δb≤0.5;

[0064] The color saturation of the second color system is higher than the color saturation of the first color system.

[0065] In this embodiment, the second color of the ink is configured to enhance the superposition effect of the second color and the first color, thereby achieving a more vivid and colorful effect. Specifically, when the target color is a color with low color saturation, such as light yellow or light gray, the color difference between the second color and the target color needs to be configured to ΔL ≤ 0.3, Δa ≤ 0.1, and Δb ≤ 0.15. In this case, the target color is light / pale in the CIE color space coordinate diagram, and the target color has a low brightness. To obtain a colorful film with the target color, while using a colorless brightness enhancement film and increasing the transparency of the brightness enhancement film, the second color also needs to be controlled to a light / pale color with the same hue as the target color, and the brightness of the second color needs to be reduced to keep it consistent with the hue of the target color. When the target color is a color with high color saturation, such as pink or green, the color difference between the second color and the target color needs to be configured to ΔL≤0.7, Δa≤1.2, and Δb≤0.5; at this time, the color of the target color is deep / rich / bright in the CIE color space coordinate diagram, and the brightness of the target color is large. In order to obtain a colorful film of the target color, while using a brightening film with a certain color to provide a certain colorful effect, the color of the second color also needs to be controlled to be deep / rich / bright with the same hue as the target color, and the brightness of the second color needs to be increased to keep it consistent with the hue of the target color.

[0066] like Figure 2 As shown, in some embodiments, step S1 specifically includes the following steps S10 to S11, that is, depositing a brightness enhancement film having a first color on the target substrate includes:

[0067] Step S10: alternately depositing a first refractive index material layer and a second refractive index material layer on a target substrate, wherein the refractive index of the first refractive index material layer is greater than the refractive index of the second refractive index material layer;

[0068] Step S11: setting the thickness of the brightness enhancement film to 10 nm to 300 nm.

[0069] In this embodiment, the thickness of the entire brightness enhancement film is adjusted by adjusting the number of alternating first and second refractive index material layers and the thickness of each layer, thereby adjusting the first color of the brightness enhancement film. For example, but not limited to, the first refractive index material layer is a niobium pentoxide material layer, and the second refractive index material layer is a silicon dioxide material layer.

[0070] Of course, in other embodiments, the material of the first refractive index material layer may also be titanium pentoxide or silicon nitride; the material of the second refractive index material layer may also be magnesium fluoride or aluminum oxide.

[0071] In a specific example, the color on the first refractive index material layer is light yellow or transparent, and the color on the second refractive index material layer is transparent or other light colors close to transparent. In this way, by covering the target substrate with a light yellow or transparent first refractive index material layer, and then covering the first refractive index material layer with a transparent or light color close to transparent, a light color close to transparent or a transparent color can be obtained, and the light color or transparent color is the first color.

[0072] In one example, the different material layers of the colorful film system have a curved surface structure. Although this curved surface structure makes the colorful film system's wave peak more obvious, making the colorful film system more susceptible to the wavelength of light, this curved surface configuration of the material layers can effectively enhance the colorful effect of the colorful film system. In contrast, the first and second refractive index material layers of the brightness enhancement film in this embodiment are both flat structures. Although this flat structure reduces the brightness enhancement film's colorful effect, this flat configuration of the material layers effectively reduces the wave peak of the brightness enhancement film, reduces the influence of light wavelength on the brightness enhancement film, improves the stability of the first color on the brightness enhancement film, and facilitates the superposition of the first and second colors to achieve the target color.

[0073] In one example, the thickness of the brightness enhancement film is 10nm to 300nm. The preparation method of the colorful film provided by the present disclosure has greater adaptability to the thickness of the brightness enhancement film, which can meet the requirements of a brightness enhancement film with a thickness of 10nm to 300nm with a colorful effect. Specifically, under the premise of ensuring the colorful effect of the colorful film, the thickness of the brightness enhancement film can be set to less than 100nm. Of course, the brightness enhancement film layer can also be selected as a dielectric film with a thickness of 100nm to 200nm, or an ultra-strength film with a thickness of 200nm to 300nm.

[0074] In addition, the thickness of the brightness enhancement film is preferably 50nm to 200nm, and 200 to 300nm is second best. The present disclosure preferably coordinates the brightness enhancement film with a thickness of less than 200nm with the colored ink to produce a colorful film with a target color dazzling effect.

[0075] In some embodiments, the number of layers of the first refractive index material layer is at least two, the number of layers of the second refractive index material layer is one layer less than the number of layers of the first refractive index material layer, the first refractive index material layer and the second refractive index material layer are alternately stacked, and the ink covers the first refractive index material layer away from the target substrate.

[0076] In this embodiment, the specific structure and composition of the brightness enhancement film are optimized. Specifically, the total number of layers of the first refractive index material is increased by one layer. This allows light to enter the brightness enhancement film through the first refractive index material layer and exit the film through the first refractive index material layer. The second refractive index material layer is then enclosed within the first refractive index material layer. This allows light to be regulated within the brightness enhancement film, preventing light from entering the colored ink from being unregulated and seriously affecting the final color of the colorful film.

[0077] like Figure 3 As shown, in some embodiments, the first refractive index material layer has three layers, and the second refractive index material layer has two layers. Step S1 specifically includes the following steps S12 to S16, that is, depositing a brightness enhancement film having a first color on the target substrate includes:

[0078] Step S12: depositing a first refractive index material layer with a thickness of 23 nm to 26 nm on the target substrate;

[0079] Step S13: depositing a second refractive index material layer with a thickness of 12 nm to 15 nm on a side of the first refractive index material layer away from the target substrate;

[0080] Step S14: depositing a first refractive index material layer with a thickness of 53 nm to 59 nm on a side of the second refractive index material layer away from the target substrate;

[0081] Step S15: depositing a second refractive index material layer with a thickness of 43 nm to 49 nm on a side of the first refractive index material layer away from the target substrate;

[0082] Step S16: depositing a first refractive index material layer with a thickness of 57 nm to 64 nm on a side of the second refractive index material layer away from the target substrate.

[0083] In this embodiment, to achieve a purple dazzling effect, a brightness-enhancing film is configured as a composite film system comprising three layers of a first refractive index material and two layers of a second refractive index material, with the first and second refractive index material layers interlaced. This results in a light green or nearly transparent color. Pink ink is then applied to the brightness-enhancing film. When viewed from the pink ink side, the film appears purple, achieving the desired color. The thickness of the entire brightness-enhancing film is controlled at approximately 200 nm, while the thickness of the pink ink is controlled at approximately 17 to 19 μm. This significantly reduces the thickness of the entire dazzling film, effectively minimizing the risk of dependency on the film.

[0084] In a specific example, the preparation method of obtaining a light yellow brightness enhancement film is as follows:

[0085] First, a magnetron sputtering coater was filled with 400 sccm of argon and 80 sccm of oxygen, while maintaining the pressure at 8.8E-2Pa. An acrylic or PET substrate was selected as the target substrate and placed in the magnetron sputtering coater. The niobium target was turned on at a target power of 14 kW and a niobium pentoxide layer was deposited for 245 seconds to obtain a 24.5 nm thick niobium pentoxide layer.

[0086] Then, the magnetron sputtering coater was filled with 600 sccm of argon and 30 sccm of oxygen, while the pressure in the magnetron sputtering coater was maintained at 1.4E-1 Pa. The substrate electroplated with the niobium pentoxide layer was used as the target substrate, and the silicon target was turned on with a target power of 14 kW to deposit a silicon dioxide layer for 112 seconds, to obtain a silicon dioxide layer with a thickness of 13.5 nm.

[0087] Next, the magnetron sputtering coating machine was filled with 400 sccm of argon and 80 sccm of oxygen, while the pressure in the magnetron sputtering coating machine was maintained at 8.8E-2Pa. The substrate electroplated with the silicon dioxide layer was used as the target substrate, and the niobium target was turned on at a target power of 14 kW to deposit a niobium pentoxide layer for 560 seconds, thereby obtaining a niobium pentoxide layer with a thickness of 56 nm.

[0088] Next, the magnetron sputtering coater was filled with 600 sccm of argon and 30 sccm of oxygen, while the pressure in the magnetron sputtering coater was maintained at 1.4E-1 Pa. The substrate electroplated with the niobium pentoxide layer was used as the target substrate. The silicon target was turned on at a target power of 14 kW to deposit a silicon dioxide layer for 384 seconds, resulting in a silicon dioxide layer with a thickness of 46.03 nm.

[0089] Finally, the magnetron sputtering coating machine was filled with 400 sccm of argon and 80 sccm of oxygen, while the pressure in the magnetron sputtering coating machine was maintained at 8.8E-2Pa. The substrate electroplated with the silicon dioxide layer was used as a target substrate and placed in the magnetron sputtering coating machine. The niobium target was turned on at a target power of 14 kW to deposit a niobium pentoxide layer for 602 seconds, resulting in a niobium pentoxide layer with a thickness of 60.23 nm.

[0090] In this way, electroplating of a light yellow brightness enhancement film is achieved on the target substrate.

[0091] like Figure 4 As shown, in some embodiments, there are two layers of the first refractive index material layer and one layer of the second refractive index material layer, and step S1 specifically includes the following steps S17 to S19, that is, depositing a brightness enhancement film having a first color on the target substrate includes:

[0092] Step S17: depositing a first refractive index material layer with a thickness of 6 nm to 9 nm on the target substrate;

[0093] Step S18: depositing a second refractive index material layer with a thickness of 27 nm to 37 nm on a side of the first refractive index material layer away from the target substrate;

[0094] Step S19: depositing a first refractive index material layer with a thickness of 36 nm to 49 nm on a side of the second refractive index material layer away from the target substrate.

[0095] In this embodiment, to achieve a gray dazzling effect, the brightness enhancement film is configured as a composite film system comprising two layers of a first refractive index material and a layer of a second refractive index material, with the second refractive index material layer disposed between the two first refractive index material layers. This results in the brightness enhancement film being transparent or light gray-green. Gray ink is then applied to the brightness enhancement film. When viewed from the gray ink side, the film appears light gray, achieving the desired color. The thickness of the entire brightness enhancement film layer is controlled between 71nm and 94nm, and the thickness of the gray ink is controlled between 20μm and 22μm, significantly reducing the thickness of the entire dazzling film and effectively reducing the risk of dependence on the dazzling film.

[0096] In a specific example, the preparation method for obtaining a transparent brightness enhancement film is as follows:

[0097] First, a magnetron sputtering coater was filled with 400 sccm of argon and 80 sccm of oxygen, while maintaining the pressure at 8.8E-2Pa. An acrylic or PET substrate was selected as the target substrate and placed in the magnetron sputtering coater. The niobium target was turned on at a target power of 14 kW to deposit a niobium pentoxide layer for 79 seconds, resulting in a 7.9 nm thick niobium pentoxide layer.

[0098] Then, the magnetron sputtering coater was filled with 600 sccm of argon and 30 sccm of oxygen, while the pressure in the magnetron sputtering coater was maintained at 1.4E-1 Pa. The substrate electroplated with the niobium pentoxide layer was used as the target substrate, and the silicon target was turned on with a target power of 14 kW to deposit a silicon dioxide layer for 275 seconds to obtain a silicon dioxide layer with a thickness of 33 nm.

[0099] Then, the magnetron sputtering coating machine was filled with 400 sccm of argon, 80 sccm of XX units of argon, and XX units of oxygen, while the pressure in the magnetron sputtering coating machine was maintained at 8.8E-2Pa. The substrate electroplated with the silicon dioxide layer was used as the target substrate, and the niobium target was turned on at a target power of 14 kW to deposit a niobium pentoxide layer for 440 seconds, thereby obtaining a niobium pentoxide layer with a thickness of 44 nm.

[0100] In this way, the transparent brightness enhancement film is electroplated on the target substrate.

[0101] In some embodiments, in step S2 , the thickness of the ink having the second color is 15 μm to 30 μm.

[0102] In this embodiment, the ink thickness is optimized to optimize the second color of the ink so that it is closer to the target color when superimposed with the first color of the brightness enhancement film. For example, but not limited to, when the target color is pink, the thickness of the pink ink is 17μm to 19μm; when the target color is blue, the thickness of the blue ink is 22μm to 26μm.

[0103] In some embodiments, in step S2, the method for preparing the ink having the second color includes:

[0104] A plurality of inks of different hues are stirred and mixed to obtain ink having a second color.

[0105] In addition, the present disclosure further provides a shell, the outer surface of which is provided with a colorful film, and the colorful film is prepared by the method for preparing the colorful film as described above.

[0106] This embodiment provides a method for using a colorful film. The colorful film can be applied to a housing to achieve a colorful effect and enhance the housing's aesthetics. The housing can be for electronic products such as mobile phones, laptops, wearable devices, and electrical appliances, or it can be an automobile. The housing can be made of, for example, but not limited to, glass, sapphire, acrylic, or PET. In this way, the colorful film achieves a colorful effect while minimizing the risk of dependency and preventing issues like film cracking.

[0107] In some embodiments, the housing further includes a protective film, which covers the colorful film.

[0108] In this embodiment, a protective film is provided to increase the service life of the colorful film, and the thickness of the protective film is 5 nm to 20 nm.

[0109] In one example, to reduce the impact of the protective film on the dazzling colors provided by the colorful film, the protective film is made of a transparent material with an imaginary part of the refractive index approaching zero. For example, but not limited to, the protective film can be made of quartz, glass, ITO transparent solid, polyester film transparent flexible material, etc.

[0110] To further illustrate the beneficial effects of the colorful film produced by the method for producing the colorful film provided by the present disclosure, the following is a detailed description of the embodiments. It should be understood that this embodiment further illustrates the present disclosure and does not limit the scope of protection of the present disclosure. Furthermore, the raw materials and equipment used in the embodiments can be purchased commercially.

[0111] Purple colorful films prepared by different preparation methods in Example Group 1

[0112] 1. Control group

[0113] ① Preparation of purple colorful film:

[0114] The purple colorful film is configured as a colorful film layer and an ink layer. The structure and thickness of the colorful film layer are designed by TFC software. As shown in Table 1, the colorful film layer presents a yellow-green colorful effect. At the same time, an acrylic / PET substrate is selected and placed on the hanging plate, where the size of the substrate is 156.22mm±0.08*72.94mm±0.08mm. Then, the substrate that has passed the inspection is placed into the chamber of the magnetron sputtering coating machine Hongda 1800H through the hanging plate, and the vacuum is pumped to 5.0E~3Pa, and the above-mentioned colorful film layer program is started. After the colorful film layer is electroplated on the substrate, a white ink layer is covered on the electroplated yellow-green colorful film layer to obtain a shell with the target purple colorful film, as shown in FIG. Figure 5 shown.

[0115] Table 1 Structure and thickness of colorful film layer

[0116] Cr <![CDATA[Nb2O5]]> <![CDATA[SiO2]]> <![CDATA[Nb2O5]]> <![CDATA[SiO2]]> <![CDATA[Nb2O5]]> 0.8—5nm 8.07nm 117.96nm 55.39nm 16.71nm 97.21nm

[0117] ②Performance test on the purple colorful shell, and the results are as follows Figure 6 The test results are shown.

[0118] ③Result analysis:

[0119] The purple color of the housing is good; however, the housing exhibited film cracking during the 100-grid test, and cracking also occurred at the R corners after lamination to 3D glass. This indicates that while this color film can achieve the housing's color effect, it carries a high risk of dependency and does not meet the dependency requirements for color films.

[0120] 2. Example Group

[0121] ① Preparation method of purple colorful film:

[0122] A light yellow brightening film is electroplated on the target substrate. The structure and thickness of the brightening film are shown in Table 2. Then, a pink ink with a thickness of 17um to 19um is covered on the brightening film to obtain the shell of the target purple colorful film. Figure 12 shown.

[0123] Table 2 Structure and thickness of brightness enhancement film

[0124] Cr <![CDATA[Nb2O5]]> <![CDATA[SiO2]]> <![CDATA[Nb2O5]]> <![CDATA[SiO2]]> <![CDATA[Nb2O5]]> 0.8—5nm 24.5nm 13.5nm 56nm 46.03nm 60.23nm

[0125] ②Performance testing was performed on the purple colorful effect housing, and the test results shown in Table 3 were obtained.

[0126] Table 3 Performance test results of the shell with purple colorful effect

[0127]

[0128] ③Result analysis:

[0129] The shell has a good purple color effect; the color of the brightening film changes little; it has high hardness; no film cracking occurs in a 100-grid test; it has good heat resistance; and it is resistant to UV radiation. This shows that the colorful film produced by the method for producing a colorful film provided by the present disclosure has a good color effect and excellent performance, with strong scratch resistance, high adhesion, and aesthetic advantages.

[0130] Example Group 2 Light Gray Colorful Film

[0131] 1. Preparation of light grey colorful film:

[0132] A transparent brightness enhancement film is electroplated on the target substrate. The structure and thickness of the brightness enhancement film are shown in Table 4. Then, a gray ink with a thickness of 17um to 19um is covered on the brightness enhancement film to obtain the target light gray colorful film shell, as shown in FIG. Figure 13 shown.

[0133] Table 4 Structure and thickness of the brightness enhancement film

[0134]

[0135]

[0136] 2. The performance of the light gray colorful film was tested, and the test results shown in Table 5 were obtained.

[0137] Table 5 Performance test results of the shell with light gray colorful effect

[0138]

[0139] 3. Result analysis:

[0140] The light gray color of the housing has a good dazzling effect; the color of the brightness enhancement film changes little; the hardness is high; the electroplating effect is good in the 100-grid test; the heat resistance is good; and the UV radiation resistance is good. The colorful film prepared by the method for preparing a colorful film provided by the present disclosure has a good dazzling effect and excellent performance, with strong scratch resistance, high adhesion, and aesthetic advantages.

[0141] Example 3 Preparation of Colorful Films of Different Colors

[0142] 1. Preparation of colorful films of different light colors: A transparent brightness-enhancing film was electroplated on the target substrate, and then covered with a light / pale ink to obtain a light yellow shell and a light gray shell, respectively. The color difference between the second color and the target color in the shells of different colors was analyzed, and the results are shown in Table 6.

[0143] Table 6 Color difference relationship between the second color and the target color in different light-colored shells

[0144]

[0145] 2. Preparation of colorful films of different dark colors: A light-colored brightening film was electroplated on the target substrate, and then covered with a dark / rich ink to obtain pink and green shells, respectively. The color difference between the second color and the target color in the shells of different colors was analyzed, and the results are shown in Table 7.

[0146] Table 7 Color difference between the second color and the target color in different dark shells

[0147]

[0148] 3. Result analysis:

[0149] As shown in Tables 6 and 7, the color difference range between the second color and the target color is different in different saturation color systems. In order to obtain a shell of the target color and meet user needs, it is necessary to reasonably control the color difference between the second color and the target color. Specifically, in a light color system with low saturation, the color difference range between the second color and the target color needs to be controlled to ΔL≤0.3, Δa≤0.1, and Δb≤0.15. At this time, the brightness enhancement film is controlled to be colorless and transparent. In a dark color system with high saturation, the difference range between the second color and the target color needs to be controlled to ΔL≤0.7, Δa≤1.2, and Δb≤0.5. At this time, the brightness enhancement film is controlled to be a light transparent state.

[0150] In summary, compared to traditional methods for preparing colorful films, the method disclosed herein can effectively overcome the conflict between colorful effects and film thickness. Even when the thickness of the prepared colorful film reaches 300 nm, the risk of dependence on the film can be reduced. Furthermore, the thickness of the colorful film prepared by the method disclosed herein can be reduced to below 100 nm, effectively reducing the production cost of the colorful film, improving electroplating efficiency, and facilitating industrial production.

[0151] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0152] The foregoing description is intended only to provide specific embodiments of the present disclosure, which will enable those skilled in the art to understand and implement the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the embodiments shown herein, but rather to be construed in the broadest manner consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a colorful film, characterized in that: include: Depositing a brightness enhancement film having a first color on a target substrate, wherein the L value of the first color is less than or equal to 60, the a value of the first color is -10 to 10, and the b value of the first color is -10 to 10; Covering the brightness enhancement film with ink having a second color to form a target color, wherein the second color has the same hue as the target color; The color difference between the second color and the target color is: When the second color is a first color system, the L difference between the second color and the target color is ΔL, the a difference between the second color and the target color is Δa, and the b difference between the second color and the target color is Δb, where ΔL≤0.3, Δa≤0.1, and Δb≤0.15; When the second color is a second color system, the L difference between the second color and the target color is ΔL, the a difference between the second color and the target color is Δa, and the b difference between the second color and the target color is Δb, where ΔL≤0.7, Δa≤1.2, and Δb≤0.5; The color saturation of the second color system is higher than the color saturation of the first color system.

2. The method for preparing a colorful film according to claim 1, characterized in that: Depositing a brightness enhancing film having a first color on a target substrate includes: alternately depositing a first refractive index material layer and a second refractive index material layer on the target substrate so that the thickness of the brightness enhancing film is 10nm~300nm; wherein the refractive index of the first refractive index material layer is greater than the refractive index of the second refractive index material layer.

3. The method for preparing a colorful film according to claim 2, characterized in that: The first refractive index material layer has three layers, the second refractive index material layer has two layers, and the step of depositing a brightness enhancement film having a first color on the target substrate includes: Depositing a first refractive index material layer with a thickness of 23 nm to 26 nm on the target substrate; Depositing a second refractive index material layer with a thickness of 12 nm to 15 nm on a side of the first refractive index material layer away from the target substrate; Depositing a first refractive index material layer with a thickness of 53 nm to 59 nm on a side of the second refractive index material layer away from the target substrate; Depositing a second refractive index material layer with a thickness of 43 nm to 49 nm on a side of the first refractive index material layer away from the target substrate; A first refractive index material layer with a thickness of 57 nm to 64 nm is deposited on a side of the second refractive index material layer away from the target substrate.

4. The method for preparing a colorful film according to claim 2, characterized in that: The first refractive index material layer has two layers, the second refractive index material layer has one layer, and the step of depositing a brightness enhancement film having a first color on the target substrate includes: Depositing a first refractive index material layer with a thickness of 6 nm to 9 nm on the target substrate; Depositing a second refractive index material layer with a thickness of 27 nm to 37 nm on a side of the first refractive index material layer away from the target substrate; A first refractive index material layer with a thickness of 36 nm to 49 nm is deposited on a side of the second refractive index material layer away from the target substrate.

5. The method for preparing a colorful film according to any one of claims 2 to 4, characterized in that: The material of the first refractive index material layer is any one of Nb2O5, Ti3O5 or Si3N4; And / or, the material of the second refractive index material layer includes any one of SiO 2 , MgF 2 or Al 2 O 3 .

6. The method for preparing a colorful film according to claim 1, characterized in that: The thickness of the ink having the second color is 15 μm to 30 μm.

7. The method for preparing a colorful film according to claim 6, characterized in that: The method for preparing the ink having the second color comprises: A plurality of inks of different hues are stirred and mixed to obtain ink having a second color.

8. A housing, characterized in that: The outer surface of the shell is provided with a colorful film, and the colorful film is prepared by the method for preparing a colorful film according to any one of claims 1 to 7.

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