Preparation method of high-precision 3D relief pattern with color changing effect

Abstract

The invention discloses a preparation method of a high-precision 3D relief pattern with a color changing effect. The method comprises the following steps: step 1, cleaning the surface of a glass substrate by adopting a cleaning solution; step 2, spin-coating photoresist on the cleaned surface of the glass substrate; 3, forming a grey-scale map by the low-frequency sawtooth grating and the high-frequency blazed grating, and importing the grey-scale map into laser direct writing equipment; step 4, etching the photoresist by adopting the laser direct writing equipment; step 5, developing the etched sample; and step 6, plating a metal film on the surface of the developed sample. The color-changing 3D relief pattern prepared by the method is high in micro-nano structure morphology precision and obvious in three-dimensional effect, has a color-changing effect when being observed from different visual angles, and is uniform in color change. The preparation method provided by the invention has no pollution hidden danger to the environment and is a green preparation method.

Description

Technical Field

[0001] The invention relates to the field of photolithography, and in particular to a method for preparing a high-precision 3D relief pattern with a color-changing effect. Background Art

[0002] Color-changing anti-counterfeiting technology has great application prospects in the fields of tobacco, wine, and currency, and has therefore received widespread attention from industry and academia. Ink color change has always been the mainstream technology for color-changing anti-counterfeiting.

[0003] At present, the inks that can be used for color-changing anti-counterfeiting mainly include temperature-sensitive inks, optically variable inks, moisture-sensitive inks, and pressure-sensitive inks. For example, the Chinese patent application with publication number CN108460444A discloses the use of temperature-sensitive inks to prepare QR code anti-counterfeiting labels. The labels are colorless and transparent at room temperature and show color after heating. The Chinese patent application with publication number CN101070040A discloses the use of optically variable inks to prepare patterned security devices, and in the embodiments, optically variable inks are applied to banknote anti-counterfeiting. Chinese patents (CN 202677720U) and Chinese patents (CN213082551U) respectively use moisture-sensitive inks to prepare anti-counterfeiting logos and label papers, which can display anti-counterfeiting information under different humidity conditions, and play a role in quickly distinguishing true from false. The Chinese patent application with publication number CN103318523A discloses that pressure-sensitive ink is placed under the bottle cap to prepare an anti-counterfeiting bottle cap with a hidden secret mark. When the bottle cap is rotated downward to press the pressure-sensitive ink, the transparent secret mark gradually appears.

[0004] The above solutions all use color-changing ink to achieve the purpose of anti-counterfeiting. However, during the production and use of color-changing ink, harmful gases and harmful wastewater will be generated, which poses a potential pollution risk to the environment. Summary of the invention

[0005] In order to solve the defects of the prior art, the present invention proposes a method for preparing a high-precision 3D relief pattern with a color-changing effect, which can replace ink dyes and eliminate the environmental pollution problems (harmful gases and harmful wastewater) caused by ink dyes during production and use.

[0006] One aspect of the present invention provides a method for preparing a high-precision 3D relief pattern with a color-changing effect, comprising the following steps:

[0007] Step 1, cleaning the surface of the glass substrate with a cleaning solution;

[0008] Step 2, spin coating the photoresist onto the cleaned surface of the glass substrate;

[0009] Step 3, combining the low-frequency sawtooth grating and the high-frequency blazed grating into a grayscale image, and importing the grayscale image into a laser direct writing device;

[0010] Step 4, etching the photoresist using the laser direct writing device;

[0011] Step 5, developing the etched sample; and

[0012] Step 6, coating a metal film on the surface of the developed sample.

[0013] Preferably, in step 2, the photoresist is preferably S1818, the spin coating speed is 2000-4000 rpm, and the thickness of the photoresist is 2-4 μm.

[0014] Preferably, in step 3, the structure of the low-frequency sawtooth grating is a right triangle with a height of 1 to 2 μm, and the width of the structure in the same relief pattern is variable within a range of 5 to 300 μm.

[0015] Preferably, in step 3, the structure of the high-frequency blazed grating is an isosceles triangle with a height of 0.4-0.8 μm, an aspect ratio of 1-2, an invariable width in the same relief pattern, and the center spacing of the high-frequency blazed grating structure is the same as its structural width.

[0016] Preferably, in step 3, the region of the low-frequency sawtooth grating and the region of the high-frequency blazed grating are arranged alternately in the horizontal and vertical directions to form the grayscale image.

[0017] Preferably, in step 3, the area ratio of the regions of the multiple low-frequency sawtooth gratings to the regions of the multiple high-frequency blazed gratings is 1:1.

[0018] Preferably, the etching speed of the laser direct writing device is 50-400 mm / s, the laser power is 1000-2000 μW, the laser frequency is 200-500 KHz, and the spot diameter is 0.2-1.2 μm.

[0019] Preferably, in step 5, the developer is preferably AZ400K, the developer concentration is 10% to 30%, and the developing time is 20 to 80 seconds.

[0020] Preferably, in step 6, the substrate of the metal film is a mixture of one or more elemental metals of gold, silver, aluminum, nickel and thorium, or a mixture of one or more compound materials of gold, silver, aluminum, nickel and thorium.

[0021] Another aspect of the present invention provides a 3D relief pattern with a high-precision color-changing effect, wherein the 3D relief pattern is prepared by the aforementioned preparation method.

[0022] The beneficial effects of the present invention are:

[0023] The present invention effectively combines a sawtooth grating microstructure and a high-frequency blazed grating microstructure, and prepares a 3D relief pattern with a color-changing effect through a laser direct writing process. The color-changing 3D relief prepared by the present invention has high micro-nanostructure morphology accuracy, obvious three-dimensional effect, and a color-changing effect observed from different viewing angles, and the color changes evenly. The preparation method of the present invention has no environmental pollution risks and is a green preparation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the implementation methods in combination with the following drawings, among which:

[0025] Figure 1 This is a flow chart of preparing a 3D relief pattern with a high-precision color-changing effect according to Example 1 of the present invention;

[0026] Figure 2 3D relief pattern (conch) in Example 1 of the present invention;

[0027] Figure 3 This is a color comparison diagram of the same 3D relief pattern (conch) at different viewing angles in Example 1 of the present invention;

[0028] Figure 4 The figures are color comparison diagrams of two 3D relief patterns (conch) with different frequencies at the same viewing angle, wherein (A) is a schematic diagram of the 3D relief pattern (conch) of Example 1, and (B) is a schematic diagram of the 3D relief pattern (conch) of Example 2;

[0029] Figure 5 This is a physical picture of the arrangement of the low-frequency sawtooth grating and the high-frequency blazed grating of the 3D relief pattern (conch) in Example 1 of the present invention, wherein Figure 5 (A) is the laser confocal three-dimensional display mode, Figure 5 (B) is the laser + color display mode, Figure 5 (C) Figure 5 (A) Enlarged image of the dotted line part;

[0030] Figure 6 is a schematic diagram of a 3D relief pattern (conch) in Example 1 of the present invention, wherein Figure 6 (A) is the overall structure diagram. Figure 6 (B) and Figure 6 (C) is a local structure diagram.

[0031] In the figure: 101-beaker, 102-cleaning solution, 103-glass substrate, 104-dropper, 105-photoresist droplet, 106-computer, 107-laser direct writing equipment, 108-photoresist film before exposure, 109-developing solution, 110-photoresist film before exposure, 111-metal coating. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The method for preparing a high-precision 3D relief pattern with a color-changing effect provided by the present invention combines a low-frequency sawtooth grating and a high-frequency blazed grating structure to prepare a 3D relief pattern with a distinct three-dimensional structure. The relief pattern has a color-changing function, and the changed color is uniform. In addition, the preparation method of the present invention is green, environmentally friendly and pollution-free.

[0034] In the method for preparing a high-precision 3D relief pattern with a color-changing effect of the present invention, the low-frequency sawtooth grating can make the relief pattern have an obvious three-dimensional effect, the high-frequency blazed grating can make the relief pattern present color, and the metal plating can enhance the color effect of the relief pattern. The present invention realizes the display of a 3D relief pattern with a color-changing effect by combining a combination of a low-frequency sawtooth grating and a high-frequency blazed grating, laser direct writing and metal plating processes.

[0035] The present invention provides a method for preparing a high-precision 3D relief pattern with a color-changing effect, the preparation method comprising the following steps:

[0036] Step 1: Clean the surface of the glass substrate with a cleaning solution. Preferably, acetone, alcohol and deionized water are used to clean the substrate in sequence.

[0037] Step 2, spin-coating the photoresist onto the cleaned glass substrate surface. In this step, the photoresist is preferably S1818, and when the film thickness is between 2 and 4, S1818 has an excellent effect. Preferably, the spin-coating speed is 2000-4000 rpm, and the photoresist thickness is 2-4 μm.

[0038] Step 3, combining a plurality of low-frequency sawtooth gratings and a plurality of high-frequency blazed gratings to form a grayscale image, and importing the grayscale image into a laser direct writing device.

[0039] In a preferred embodiment of the present invention, the structure of the high-frequency blazed grating is an isosceles triangle with a height of 0.4 to 0.8 μm (for example, the height can be 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, and 0.8 μm). The aspect ratio of the high-frequency blazed grating is 1 to 2 (for example, the aspect ratio can be 1, 1.5, and 2), the width in the same relief pattern is not variable, and the center spacing of the grating structure is the same as its structural width (isosceles triangle width). The high-frequency isosceles triangle makes the relief structure appear colorful through diffraction. The grating diffraction formula is d(sinθ m +sinθ i )=mλ, where d is the grating constant, θ m is the diffraction angle, θ i is the incident angle, m is the diffraction order, and λ is the wavelength of light; by adjusting the height and width of the isosceles triangle, θ can be changed. m and θ i When m remains unchanged, λ changes, so the color of the relief structure will also change, thus achieving a color-changing effect.

[0040] In addition, in a preferred embodiment of the present invention, the low-frequency sawtooth grating structure is an isosceles triangle with a height of 1 to 2 μm. The width of the structure in the same relief pattern is variable, and the range of variation is 5 to 300 μm. The principle that the low-frequency sawtooth grating can make the relief pattern have a significant three-dimensional effect is the contrast between light and shadow. When light shines on the right-angled triangle micro-pattern, different light and dark areas will be generated. The longer the hypotenuse of the right-angled triangle, the gentler the slope formed by the hypotenuse and the base, the more light will be reflected into the human eye, and the brighter the area; conversely, the darker the area, this light and dark contrast will produce a 3D stereoscopic effect in the human eye, with the bright area being convex and the dark area being concave. The brighter the place, the longer the hypotenuse, and the longer the triangle period; conversely, the shorter the period.

[0041] And, in a preferred embodiment of the present invention, the low-frequency sawtooth grating region and the high-frequency blazed grating region are arranged alternately in the horizontal and vertical directions to form the grayscale image. In this arrangement, the ratio of the area of ​​the low-frequency sawtooth grating region to the area of ​​the high-frequency blazed grating region is 1:1, that is, the area of ​​the low-frequency sawtooth grating region is the same as the area of ​​the high-frequency blazed grating region.

[0042] Step 4: Etch the photoresist using a laser direct writing device.

[0043] In a preferred embodiment of the present invention, the etching speed of the laser direct writing device is 50 to 400 mm / s (e.g., 50 mm / s, 100 mm / s, 150 mm / s, 200 mm / s, 250 mm / s, 300 mm / s, 350 mm / s, 400 mm / s). Under the same conditions, the smaller the etching speed value of the laser direct writing device, the finer the etched structure, but the slower the speed; the larger the etching speed value, the faster the etching speed, but the coarser the structure.

[0044] In the method for preparing a high-precision 3D relief pattern with a color-changing effect in a preferred embodiment of the present invention, the laser power of the laser direct writing device is 1000-2000μW (e.g., 1000μW, 1250μW, 1500μW, 1750μW, 2000μW). Under the same conditions, the smaller the laser power, the shallower the etching depth, that is, the smaller the height value of the isosceles triangle; the greater the laser power, the greater the height value of the etched pattern.

[0045] Preferably, the spot diameter of the laser direct writing device is 0.2 to 1.2 μm (for example, 0.2 μm, 0.4 μm, 0.6 μm, 0.8 μm, 1 μm, 1.2 μm). The smaller the spot diameter, the finer the etched structure, but the slower the speed; the larger the spot diameter, the faster the etching speed, but the rougher the structure.

[0046] Step 5, developing the etched sample.

[0047] In a preferred embodiment of the present invention, the developer concentration is 10% to 30% (e.g., 10%, 15%, 20%, 25%, 30%). If the developer concentration is too low, the exposed photoresist cannot be fully removed, and the prepared 3D relief cannot show the full picture; if the developer concentration is too high, the photoresist may be removed too much, thereby damaging the morphology of the 3D relief.

[0048] In a preferred embodiment of the present invention, the developing time is 20 to 80 s (e.g., 20 s, 30 s, 40 s, 50 s, 60 s, 70 s, 80 s). If the developing time is too short, the developer cannot fully remove the exposed photoresist, and the prepared 3D relief cannot show the full picture; if the developing time is too long, the developer will easily remove too much photoresist and damage the morphology of the 3D relief.

[0049] Step 6: Plate a metal film on the surface of the developed sample to form the 3D relief pattern. In this step, the substrate of the metal film is a mixture of one or more elemental metals of gold, silver, aluminum, nickel and pickaxe, or a mixture of one or more compound materials of gold, silver, aluminum, nickel and pickaxe.

[0050] Example 1

[0051] Combine the following Figure 1-3, 5-6 describe Example 1 of the present invention in detail. Figure 1 : is a preparation flow chart of a method for preparing a high-precision 3D relief pattern with a color-changing effect according to Example 1 of the present invention, as shown in FIG. Figure 1 As shown, the preparation method of Example 1 comprises the following steps:

[0052] S1. Pour 50 ml of acetone (washing solution 102) into beaker 101 to remove organic impurities on the surface of 2-inch glass substrate 103; pour out the acetone solution, pour 40 ml of alcohol (washing solution 102) into beaker 101 to remove residual acetone on the surface of glass substrate 103; pour out the alcohol solution, pour 60 ml of deionized water (washing solution 102) into beaker 101 to remove residual alcohol on the surface of glass substrate 103. After cleaning, blow dry the glass substrate 103 with N2;

[0053] S2. The S1818 photoresist 105 is transferred to the glass substrate 103 using a dropper 104, the spin coater is turned on, the spin coating speed is set to 2000 rpm, and the spin coating time is 35 s;

[0054] S3. Import the grayscale image composed of the low-frequency sawtooth grating and the high-frequency blazed grating into the computer host 105, wherein the structure of the high-frequency blazed grating is an isosceles triangle with a height of 0.5 μm, a base length of 1 μm, and a center spacing of 1 μm; the structure of the low-frequency sawtooth grating is a right triangle with a height of 1.55 μm and a structure width, i.e., a base length of 5 to 300 μm. In other words, in the same relief pattern, the width of the low-frequency sawtooth grating in different areas can be variable.

[0055] S4. Expose the photoresist using a laser direct writing device, where the laser power is set to 1.25 mW, the spot size is 0.6 μm, and the laser frequency is 500 KHz;

[0056] S5. The exposed photoresist sample is placed in a developer having a concentration of 20% and a development time of 30 s;

[0057] S6. After the photoresist sample is developed, it is metal-coated, wherein the coating metal is aluminum and the coating thickness is 100 nm, thereby preparing a 3D relief pattern (conch) with a high-precision color-changing effect.

[0058] Figure 2 This is a top view of the 3D relief pattern (conch) in Example 1 of the present invention. Figure 2 As shown, under natural light conditions and when viewed from above, the 3D relief pattern appears colorless and transparent. Figure 3 Actual pictures of the same 3D relief pattern (conch) under natural light conditions and different viewing angles. Figure 3It can be clearly seen that the 3D relief pattern has color when observed from three different viewing angles; secondly, the color of the 3D relief pattern is different when observed from different viewing angles, (a) is blue-green, (b) is milky white, and (c) is orange-red, thus having a color-changing effect.

[0059] As mentioned above Figure 2 and Figure 3 As shown, the relief pattern (conch) prepared in Example 1 of the present invention has an obvious 3D effect, presents bright colors, and presents different colors at different viewing angles, with a color-changing effect.

[0060] like Figure 5 Shown are actual pictures of the arrangement of low-frequency grating and high-frequency grating of the 3D relief pattern (conch) in Example 1 of the present invention, wherein (A) is the laser confocal three-dimensional display mode, (B) is the laser + color display mode, and (C) is an enlarged image of the dotted part in (A), which presents the measured curve morphology of the low-frequency sawtooth grating and the high-frequency blazed grating. Figure 5 In the figure, 51 is a low-frequency sawtooth grating area, and 52 is a high-frequency blazed grating area. The low-frequency sawtooth grating area 51 and the high-frequency blazed grating area 52 are arranged alternately in the horizontal and vertical directions to form the grayscale image. Under this arrangement, the ratio of the area of ​​the low-frequency sawtooth grating area 51 to the area of ​​the high-frequency blazed grating area 52 is 1:1. The advantages of this arrangement are that it can ensure both a good 3D effect and bright colors.

[0061] Figure 6 is a schematic diagram of a 3D relief pattern (conch) in Example 1 of the present invention, wherein Figure 6 (A) is the overall structure diagram. Figure 6 (B) and Figure 6 (C) is a local structure diagram. Figure 6 (B) shows the structure of the 3D relief depression. Figure 6 (C) shows the structure of the 3D relief protrusions, and Figure 6 (B) and Figure 6 (C) The different period lengths of the low-frequency gratings in different design areas are clearly presented.

[0062] Example 2

[0063] The present embodiment provides a method for preparing a high-precision 3D relief pattern with a color-changing effect, comprising the following steps:

[0064] S1. Pour 40 ml of acetone (washing solution 102) into beaker 101 to remove organic impurities on the surface of 2-inch glass substrate 103; pour out the acetone solution, pour 30 ml of alcohol (washing solution 102) into beaker 101 to remove residual acetone on the surface of glass substrate 103; pour out the alcohol solution, pour 80 ml of deionized water (washing solution 102) into beaker 101 to remove residual alcohol on the surface of glass substrate 103. After cleaning, blow dry the glass substrate 103 with N2;

[0065] S2. The S1818 photoresist 105 is transferred to the glass substrate using a dropper 104, the spin coater is turned on, the spin coating speed is set to 2500 rpm, and the spin coating time is 30 s;

[0066] S3. A grayscale image composed of a sawtooth grating and a high-frequency blazed grating is imported into the computer host 105. The high-frequency blazed grating is an isosceles triangle with a height of 0.5 μm, a base length of 1.18 μm, and a center spacing of 1.18 μm; the low-frequency sawtooth grating is an isosceles triangle with a height of 1.55 μm, and a structure width, i.e., a base length of 5 to 300 μm. In other words, in the same relief pattern, the width of the low-frequency sawtooth grating in different regions can be variable.

[0067] S4. Expose the photoresist using a laser direct writing device, where the laser power is set to 1.25 mW, the spot size is 0.6 μm, and the laser frequency is 500 KHz;

[0068] S5. The exposed photoresist sample is placed in a developer having a concentration of 20% and a development time of 30 s;

[0069] S6. After the photoresist sample is developed, a metal coating is performed on it, wherein the coating metal is aluminum and the coating thickness is 100 nm;

[0070] The relief pattern (conch) prepared in Example 2 is as follows: Figure 4 As shown in (B), it has a clear 3D effect and also presents bright colors. When observed from the same viewing angle, the colors presented in Example 2 are similar to those in Example 3. Figure 4 (A) The colors of the relief patterns in Example 1 are different. It can be seen that in Example 2, by changing the width of the high-frequency blazed grating, the color of the relief pattern prepared can be changed accordingly, that is, when the width of the high-frequency blazed grating is different, the relief pattern prepared presents different colors at the same viewing angle.

[0071] Comparative Example 1

[0072] The difference between this comparative example and Example 1 is that a high-frequency block grating is used instead of a high-frequency blazed grating in step S3, and the other steps and methods are the same as those in Example 1 and will not be repeated here.

[0073] The relief pattern (conch) prepared in Comparative Example 1 has an obvious 3D effect, but does not show color.

[0074] Comparative Example 2

[0075] The difference between this comparative example and Example 1 is that a high-frequency sin grating is used instead of a high-frequency blazed grating in step S3, and the other steps and methods are the same as those in Example 1 and will not be repeated here.

[0076] The relief pattern (conch) prepared in Comparative Example 2 has an obvious 3D effect and also presents color, but the color difference uniformity is not good and is relatively mixed.

[0077] In summary, the method for preparing a high-precision 3D relief pattern with a color-changing effect provided by the present invention combines a low-frequency sawtooth grating and a high-frequency blazed grating structure in design, and combines laser direct writing and metal plating in process. The prepared high-precision 3D relief pattern has an obvious three-dimensional effect. The present invention has a color-changing effect at different viewing angles, changes color evenly, and has no risk of fading. The preparation method of the present invention has no environmental pollution risks and is a green preparation method.

[0078] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing a high-precision 3D relief pattern with a color-changing effect, characterized in that: The method comprises the following steps: Step 1, cleaning the surface of the glass substrate with a cleaning solution; Step 2, spin coating the photoresist onto the cleaned surface of the glass substrate; Step 3, combining the low-frequency sawtooth grating and the high-frequency blazed grating into a grayscale image, and importing the grayscale image into a laser direct writing device; Step 4, etching the photoresist using the laser direct writing device; Step 5, developing the etched sample; and Step 6: coating a metal film on the surface of the developed sample to form the 3D relief pattern.

2. The method for preparing a high-precision 3D relief pattern with a color-changing effect according to claim 1, characterized in that: In the step 2, the photoresist is preferably S1818, the spin coating speed is 2000-4000 rpm, and the thickness of the photoresist is 2-4 μm.

3. The method for preparing a high-precision 3D relief pattern with a color-changing effect according to claim 1, characterized in that: In step 3, the structure of the low-frequency sawtooth grating is a right triangle with a height of 1 to 2 μm. The width of the structure in the same relief pattern is variable within a range of 5 to 300 μm.

4. The method for preparing a high-precision 3D relief pattern with a color-changing effect according to claim 1, characterized in that: In step 3, the structure of the high-frequency blazed grating is an isosceles triangle with a height of 0.4 to 0.8 μm and an aspect ratio of 1 to 2. The width in the same relief pattern is constant, and the center spacing of the high-frequency blazed grating structure is the same as its structural width.

5. The method for preparing a high-precision 3D relief pattern with a color-changing effect according to claim 1, characterized in that: In the step 3, the region of the low-frequency sawtooth grating and the region of the high-frequency blazed grating are arranged alternately in the horizontal and vertical directions to form the grayscale image.

6. The method for preparing a high-precision 3D relief pattern with a color-changing effect according to claim 5, characterized in that: In step 3, the area ratio of the regions of the multiple low-frequency sawtooth gratings to the regions of the multiple high-frequency blazed gratings is 1:

1.

7. The method for preparing a high-precision 3D relief pattern with a color-changing effect according to claim 1, characterized in that: The etching speed of the laser direct writing device is 50-400 mm / s, the laser power is 1000-2000 μW, the laser frequency is 200-500 KHz, and the spot diameter is 0.2-1.2 μm.

8. The method for preparing a high-precision 3D relief pattern with a color-changing effect according to claim 1, characterized in that: In the step 5, the developer is preferably AZ400K, the developer concentration is 10% to 30%, and the developing time is 20 to 80 seconds.

9. The method for preparing a high-precision 3D relief pattern with a color-changing effect according to claim 1, characterized in that: In step 6, the substrate of the metal film is a mixture of one or more single metals of gold, silver, aluminum, nickel and tantalum, or a mixture of one or more compound materials of gold, silver, aluminum, nickel and tantalum.

10. A 3D relief pattern with high-precision color-changing effect, characterized in that: The 3D relief pattern is prepared by the preparation method according to any one of claims 1 to 9.

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