A color-changing material based on the angle color-changing mechanism of the Papilio concave multi-layer structure and its preparation method

Abstract

The present invention relates to an angle color-changing model based on the concave multi-layer structure of the genus Papilio, which includes model units arranged in an array. Each model unit comprises a color information layer and a transparent layer, and the transparent layer covers the color information layer. The color information layer includes a rectangular thin layer with a central hole at its geometric center. The rectangular thin layer is divided into an even number of blocks, and the blocks are filled with pigment colors. The rectangular thin layer includes at least two different pigment colors. The transparent layer is recessed from the surface towards the central hole of the rectangular thin layer to form a three-dimensional recessed space, and the recessed space includes a plurality of inclined surfaces, and each inclined surface is arranged radially away from the center with the central hole as the center. The included angle between the inclined surface and the rectangular thin layer is 45°-75°. The ratio of the total thickness of the transparent layer to the width of the rectangular thin layer is 0.75-1.2. Based on the foregoing model and combined with the full-color 3D printing technology, a Papilio simulated angle color-changing material can be prepared, realizing the simulation of the dynamic color of the concave multi-layer structure of the genus Papilio from a macroscopic perspective.

Description

Technical Field

[0001] The present invention belongs to the technical field of new materials, and in particular to a color-changing material based on the angle color-changing mechanism of a Papilio concave multi-layer structure and a preparation method thereof. Background Art

[0002] Colors can be divided into structural colors, pigment colors, and combined colors. The mechanisms of these two colors are different, but both can make an object present a specific color. Structural color is the color produced by a pure physical structure without any pigment factors. Pigment color is the color produced based on the absorption or divergence of light by pigments. Combined color is a biological form formed by the combination of pigment color and structural color. Among them, structural color has many advantages that post-pigment color does not have. Compared with pigment color, which is easily affected by the environment and changes, structural color is usually composed of a simple physical structure. As long as its physical structure is not damaged, its color will not fade. Structural color not only has high brightness and high saturation, but also usually has an iridescent effect. Structural color does not rely on chemical substances such as toxic pigments and has good environmental protection.

[0003] At present, the preparation methods of single structural color materials can be divided into the following according to the optical principle of structural color: ① Rainbow films, titanium alloy anodic oxidation films, color-changing pearlescent powders, electroplated iridescence, etc. involved in multi-layer thin film interference. ② Laser direct writing, photolithography, numerical control machining, etc. involved in grating diffraction. ③ Cu2O sphere Mie scattering structural color coloring involved in scattering. ④ Dichroic glass, polarized displays, etc. involved in polarized light. ⑤ Photonic crystal structural color fibers, photonic crystal structural color fabrics, photonic crystal pigments, 3D printing to prepare patterned photonic crystals, etc. involved in photonic crystals. ⑥ Using natural biological materials to bond structural colors, etc. To obtain precise color effects in the preparation of the aforementioned single structural color materials, precise control of the microscopic structure and morphology of the materials is required. This not only requires high-precision operations, but also needs to be carried out under extremely stable environmental conditions. During the preparation process, continuous optimization is required to achieve high color consistency and repeatability. This not only requires high-precision equipment, but also places very high requirements on the professional knowledge and practical experience of designers or operators. These factors limit the effective preparation and wide application of structural color dynamic color-changing materials, and according to the existing technology, it is difficult to achieve color simulation and color control for specific purposes using currently easily available color-changing materials.

[0004] Lan Cuiqin, He Shuang and others found in the article "Research on Design Innovation Methods Inspired by Nature - Exploration of the Digital Biological Design Path" that the leopard chameleon changes its color by actively adjusting the lattice of guanine nanocrystals in the iridophore cells of the epidermis and dermis. Based on this inspiration, researchers in the industry can combine the bottom color information layer with the upper transparent crystal layer (which plays a refraction role), and by adjusting the crystal structure, the dynamic color change effect can be obtained under the influence of light refraction of different crystal structures. In addition, the structural colors on the wings of the swallowtail butterfly usually have very high brightness and saturation. This high brightness and saturation are due to its micro-nano structure being able to efficiently control the interference, diffraction, and scattering of light. For example, the wings of the blue morpho butterfly show a strong blue luster in the sun, which is very bright and has a metallic texture. With people's continuous pursuit of the quality of life, simulation materials based on the color mechanism of butterfly wings are increasingly loved and concerned in fields such as mobile terminals, automobile production, and clothing manufacturing. However, how to model and optimize the model parameters to obtain a color structure model with the optimal color effect of simulating the swallowtail butterfly wings remains a difficult problem that needs to be solved first. Summary of the Invention

[0005] (1) Technical problems to be solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a color-changing material based on the angle color-changing mechanism of the concave multi-layer structure of the swallowtail butterfly and its preparation method. By building an angle color-changing model of the concave multi-layer structure of the swallowtail butterfly and optimizing the model structure parameters, a color structure model with the optimal color effect is obtained, and a swallowtail butterfly simulation material is prepared by combining the Stratasys 3D inkjet voxel printing technology, realizing the simulation of the dynamic color of the concave multi-layer structure of the swallowtail butterfly from a macroscopic perspective.

[0007] (2) Technical solutions

[0008] In the first aspect, an angle color-changing model based on the concave multi-layer structure of the swallowtail butterfly of the present invention includes: a plurality of model units arranged in an array, each model unit including a color information layer and a transparent layer, and the transparent layer is covered and combined above the color information layer; the color information layer includes a rectangular thin layer, and a central hole is provided at the geometric center position of the rectangular thin layer; the rectangular thin layer is divided into an even number of blocks, and pigment colors are filled in the blocks, and at least two different pigment colors are included in the pigment colors on the rectangular thin layer;

[0009] The transparent layer is recessed from the surface towards the central hole position of the rectangular thin layer to form a three-dimensional recessed space. The three-dimensional recessed space includes a plurality of inclined surfaces. Each inclined surface is arranged radially away from the center with the central hole position as the center. The recessed space is centrosymmetric about the axis perpendicular to and passing through the central hole position. The included angle between the inclined surface in contact with the rectangular thin layer and the plane where the rectangular thin layer is located is 45°-75°. Among them, the ratio of the total thickness of the transparent layer to the width of the rectangular thin layer is 0.75-1.2.

[0010] In this application, no material is filled in the recessed space. In this application, the transparent layer and the recessed space jointly play a refraction role. The recessed space extends all the way to the central hole position, and the inside of the central hole position is empty. Therefore, the depth of the recessed space is the same as the height of the model unit.

[0011] According to a preferred embodiment of the present invention, in the model unit, the aspect ratio of the length to the width of the rectangular thin layer is 1:0.95-1.05 (preferably a square, that is, the aspect ratio of the length to the width is 1:1). The length and width of the model unit are 2.5 mm-6 mm. The height of the model unit is 2.13 mm-7.35 mm. The thickness of the rectangular thin layer is 0.25 mm-0.6 mm. The included angle between the inclined surface in contact with the rectangular thin layer and the plane where the rectangular thin layer is located is 60°-75°. The height of the transparent layer is the height of the model unit minus the thickness of the rectangular thin layer, and the height of the transparent layer is 1.88 mm-6.75 mm.

[0012] The size of the model unit reaches the macroscopic size, and it can simulate the dynamic color of the concave multi-layer structure of the Papilio genus from a macroscopic perspective. The foregoing size and ratio of the model unit can ensure that the color-changing material for 3D printing has a good angle color-changing effect and color display smoothness. In practical applications, it can be adjusted according to the color display effect. Under the condition of ensuring the foregoing ratio and slope angle, if the 3D printing equipment and technology permit, a smaller model unit size can also be used, but the minimum should not be less than 2 mm, otherwise the color-changing effect of the forming material is poor.

[0013] According to a preferred embodiment of the present invention, the included angle between the inclined surface in contact with the rectangular thin layer and the plane where the rectangular thin layer is located is 60°-75°, preferably 63° or 70°.

[0014] According to a preferred embodiment of the present invention, the area of the central hole position accounts for 4 / 64-9 / 64 of the area of the rectangular thin layer, and the inside of the central hole position is empty or filled with a transparent material.

[0015] According to a preferred embodiment of the present invention, the rectangular thin layer of the color information layer is divided into two blocks by a diagonal line, and the two blocks are filled with different pigments respectively; or the rectangular thin layer of the color information layer is divided into two blocks by the midline of one side, and the two blocks are filled with different pigments respectively. For example, one block is filled with dark blue and the other block is filled with light blue.

[0016] According to a preferred embodiment of the present invention, the rectangular thin layer of the color information layer is divided into four blocks by two intersecting diagonal lines, and the four blocks are filled with two pigment colors in an alternating manner; or the rectangular thin layer of the color information layer is divided into four blocks by the midlines of two adjacent sides, and the four blocks are filled with two pigment colors in an alternating manner. For example, the first block is filled with dark blue, the second block adjacent to it is filled with light blue, the third block adjacent to the second block is filled with dark blue, and the fourth block adjacent to it is filled with light blue.

[0017] In practical applications, the distribution and proportion of the transparent layer and the color information layer in the model unit can be optimized and adjusted. Through the optimization and adjustment, the interaction of light between different layers can be further accurately controlled to achieve the purpose of simulating the angle color change phenomenon of the concave multi-layer structure.

[0018] According to a preferred embodiment of the present invention, in the angle color change model based on the concave multi-layer structure of the Papilio genus, multiple model units are arranged in an array continuously in a manner that the blocks with the same color in the color information layer are adjacent; or multiple model units are arranged in an array continuously in a manner that the blocks with different colors in the color information layer are adjacent.

[0019] According to a preferred embodiment of the present invention, the transparent layer is only one layer, and the transparent layer is recessed from the surface towards the central hole position of the rectangular thin layer to form a concave space in the shape of a frustum of a pyramid. The four faces of the concave space are inclined planes in the shape of isosceles trapezoids, and the angle between the inclined plane and the horizontal plane where the rectangular thin layer is located is 45° - 75° (preferably 60 - 75°). The center of the bottom surface of the concave space is vertically aligned with the central hole position of the rectangular thin layer. Preferably, when the aspect ratio of the rectangular thin layer is 1:1, the concave space is in the shape of a regular frustum of a pyramid.

[0020] In some embodiments of the present invention, the transparent layer comprises a plurality of stacked sub-layers, and a concave space is formed in the middle of each transparent layer. The order from bottom to top is set as follows: the first sub-layer is recessed from the surface towards the central hole of the rectangular thin body to form a first concave space in the shape of a frustum of a pyramid; the second sub-layer is recessed from the surface towards the first concave space to form a second concave space in the shape of a frustum of a pyramid. According to this rule, the nth sub-layer is recessed from the surface towards the (n - 1)th concave space to form the nth concave space in the shape of a frustum of a pyramid; the included angles between the inclined surfaces around the concave spaces of each sub-layer and the horizontal plane where the rectangular thin body is located are the same or different.

[0021] In some embodiments of the present invention, the side wall of the concave space is a convex octagonal cone or a cross shape, and the horizontal cross-section of the concave space is a convex octagon or a cross shape composed of twelve sides. Moreover, the inclined surface of the concave space is composed of multiple connected inclined surfaces from bottom to top, and the included angles between each connected inclined surface and the color information layer are different or the same. In this embodiment, the number of inclined surfaces is relatively large, and the formed color-changing material can reflect more colors. Under the concept of the present invention's solution, the specific shape of the model unit can be selected according to the required effect of the material.

[0022] In a second aspect, a method for preparing a color-changing material based on the angle color-changing mechanism of the Papilio concave multi-layer structure of the present invention includes the following steps:

[0023] Modeling according to the angle color-changing model of the Papilio genus concave multi-layer structure described in any of the above embodiments; then, using the Stratasys 3D inkjet voxel printing technology, printing and forming the color information layer with a colored photosensitive polymer material, and printing and forming the transparent layer with a transparent photosensitive polymer material; after printing, curing under UV light to obtain the color-changing material based on the angle color-changing mechanism of the Papilio concave multi-layer structure.

[0024] In a third aspect, the present invention provides a color-changing material based on the angle color-changing mechanism of the Papilio concave multi-layer structure, which is prepared by the above preparation method. Among them, the refractive index of the transparent photosensitive polymer material is preferably 1.55 - 1.60 (preferably 1.56).

[0025] (III) Beneficial effects

[0026] By constructing an angle color-changing model based on the Papilio genus concave multi-layer structure and optimizing the model structure parameters, the present invention obtains a color structure model with the optimal color effect, and combines the Stratasys 3D inkjet voxel printing technology to prepare a Papilio simulation material, realizing the simulation of the dynamic color of the Papilio genus concave multi-layer structure from a macroscopic perspective.

[0027] The present invention simplifies and designs the transparent layer structure, including the thickness of the transparent layer (the ratio to the width of the rectangular thin layer) and the shape of the concave space, etc., to achieve the effect of influencing the propagation path of light in the multi-layer structure. By simplifying the multi-layer concave structure, the preparation technical difficulty of the angle-changing material is reduced, and the material consumption is also reduced.

[0028] The present invention uses photosensitive materials for printing, thereby enabling the color simulation and color control of the dynamic color of the concave multi-layer structure of the genus Papilio using easily obtainable and inexpensive materials.

[0029] The present invention can be printed within the model unit size range of 6 mm - 2.5 mm, without the need for precise control of the microscopic structure morphology of the material, with low operation precision requirements. Compared with the current preparation technology of single structural color materials, the present invention prepares a color-changing material based on the angle-changing mechanism of the concave multi-layer structure of the genus Papilio, without the need to carry out in extremely stable environmental conditions, and the preparation process is simple and easy to control, with high repeatability and consistency. Through the technology of the present invention, the dynamic angle-changing simulation material of the genus Papilio has been further promoted and applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Analysis of the differences in the color and angle-changing phenomenon of the multi-layer concave structural color of the genus Papilio.

[0031] Figure 2 Construction process of the angle-changing model based on the concave multi-layer structure of the genus Papilio of the present invention.

[0032] Figure 3 Schematic diagram of the structure of a model unit in the angle-changing model based on the concave multi-layer structure of the genus Papilio constructed in Example 1.

[0033] Figure 4 According to Example 1 Figure 3 Photo of the color-changing material produced by Stratasys full-color 3D printing of the constructed model.

[0034] Figure 5 Two different color layout methods of the color information layer in the model unit of Example 3.

[0035] Figure 6 Array combination of the model unit of Example 3 in two different ways.

[0036] Figure 7 Schematic diagram of the transparent layer composed of several transparent layer sub-layers stacked together in Example 4.

[0037] Figure 8 Schematic diagram of the concave space of the transparent layer being in the shape of a convex octahedral cone or a cross in Example 5. DETAILED DESCRIPTION OF THE INVENTION

[0038] For a better explanation of the present invention for easy understanding, the present invention will be described in detail below in conjunction with the accompanying drawings and through specific embodiments.

[0039] Example 1

[0040] In this example, an angle-changing color model based on the concave multi-layer structure of the genus Papilio is constructed. The model construction process is as follows: Summarize the microscopic structure data of the structural color scales of Papilio bianor, Papilio ulysses, and Papilio maackii in the typical multi-layer concave structure with iridescence phenomenon in the genus Papilio, and compare and analyze the reasons for the differences in the colors and angle-changing color phenomena of the multi-layer concave structure color in the genus Papilio. The analysis results are as Figure 1 . The scales of Papilio are micron-sized, and the iridescent scales are composed of two forms: structural color scales and structural color scales + pigment color scales. The refractive index of the chitin layer is 1.56, the thickness of the air layer is 100 - 150 nm, and the refractive index of the air layer (there will be some cutin layer structures in the air layer) is 1.1 - 1.2, which is greater than the refractive index of pure air. There are a large number of depressions on the scales, the inclination angle of the depressions is 30 - 45°, the diameter of the depressions is 4 - 6 µm, and the depth is 1.5 - 2 µm. The number of chitin layers is 7 - 11 layers. Obviously, the natural multi-layer concave structure of this genus Papilio is too complex. Modeling directly based on the actual morphology of the iridescent scales of the genus Papilio will lead to extremely difficult preparation of color-changing simulation materials and high costs, and it is impossible to carry out production applications and development.

[0041] In order to transform the angle-changing color principle of the genus Papilio into an industrially applicable color-changing material and simulate the color-changing effect of Papilio, the present invention constructs a preliminary three-dimensional model based on the multi-layer concave structure prototype of Papilio maackii, and then makes the following adjustments to the preliminary three-dimensional model to obtain an angle-changing color model based on the concave multi-layer structure of the genus Papilio.

[0042] Step 1: Construct a three-dimensional model based on the multi-layer concave structure prototype of Papilio maackii to obtain a Figure 2 multi-connected concave multi-layer structure model as shown in (a); the concave multi-layer structure model includes several transparent layers, with a concave space structure in the middle of the transparent layers, and multiple transparent layers are stacked above the bottom support layer, and the bottom support layer carries color information.

[0043] Step 2: Disassemble the above multi-connected concave multi-layer structure model to obtain a Figure 2 single multi-layer concave combined color-changing model as shown in (b), and fill the 45° inclined part of the bottom side wall of the concave multi-layer structure with a transparent layer.

[0044] Step 3: Simplify the structure of a single multi-layered concave combined with a color-changing model, reduce the number of layers of the bottom support layer and the transparent layer, and obtain a single-layer concave combined with a color-changing model. According to the diffraction grating principle formed by the array arrangement of multiple concave structures, arrange the single-layer concave combined with a color-changing model in an array to obtain a combination of multiple single-layer concave combined with color-changing models as shown in Figure 2 (c). By simplifying the multi-layer concave structure, the preparation difficulty and cost of the angle color-changing material can be reduced. Using the diffraction grating principle formed by the array arrangement of multiple concave structures to arrange the model structure in an array can achieve the angle color-changing phenomenon.

[0045] Step 4: Fill the bottom support layer with colors in the mode of color blocks to obtain a color information layer, and obtain an array of multiple single-layer concave combined with color-changing models as shown in Figure 2 (d). Finally, adjust the aspect ratio of the color information layer to make the angle color-changing phenomenon of multiple single-layer concave combined with color-changing models coherent and natural. The final effect is as shown in Figure 2 (e).

[0046] Combined with Figure 3 shown, it is an enlarged view of a model unit 10 in the angle color-changing model based on the concave multi-layer structure of the genus Papilio as shown in Figure 2 (e). The model unit 10 includes a color information layer 11 and a transparent layer 12. The transparent layer 12 covers the color information layer 11. The color information layer 11 consists of a rectangular thin layer and pigment colors. A central hole 110 is provided at the geometric center position of the rectangular thin layer. Among them, the area of the central hole 110 accounts for 4 / 64 - 9 / 64 of the area of the rectangular thin layer, and the inside of the central hole is empty. The transparent layer 12 depresses from the surface towards the central hole 110 of the rectangular thin layer to form a frustum-shaped depression space. The four faces of the depression space are isosceles trapezoidal inclined surfaces 120, and the angle between the inclined surface 120 and the horizontal plane where the rectangular thin layer is located is 45° - 75°. The depression space is a centrosymmetric body figure with an axis perpendicular to and passing through the central hole 110. The center of the bottom surface of the depression space is connected to the central hole 110 of the rectangular thin layer, and the depth of the depression space is the same as the outer contour thickness of the model unit 10. Among them, the rectangular thin layer is divided into an even number of blocks, and the blocks are filled with pigment colors. The pigment colors on the rectangular thin layer include at least two different pigment colors. For example, Figure 3 (a), (b) and (c) shown, the rectangular thin layer of the color information layer 11 is divided into two blocks by a diagonal line, one block is filled with dark blue, and the other block is filled with light blue. Another example is that the rectangular thin layer of the color information layer 11 is divided into two blocks by the midline of one side, and the two blocks are filled with different pigments respectively. When the rectangular thin layer is filled with pigment colors, the color information layer 11 is obtained accordingly.

[0047] The concave space in the transparent layer 12 contains a plurality of inclined surfaces 121, the number of which is an even number. Each inclined surface 121 is arranged radially away from the center around the central hole position, and the angle between the inclined surface 121 and the plane of the rectangular thin layer is 45° - 75°. For example, Figure 3 in (a), the angle between the inclined surface 121 and the rectangular thin layer is 45°, Figure 3 in (b), the angle between the inclined surface 121 and the rectangular thin layer is 63°, Figure 3 in (c), the angle between the inclined surface 121 and the rectangular thin layer is 70°.

[0048] Furthermore, by comparing the influence of the angle size of the inclined surface 121 in the three-dimensional concave space on the angle color-changing effect, the results show that when the angle of the inclined surface 121 is in the range of 60° - 75°, the angle color-changing effect is better and the smoothness of the angle color change is more excellent. Therefore, it is preferably to make the angle between the inclined surface of the three-dimensional concave space and the rectangular thin layer between 60° - 75°. When the angle of the inclined surface 121 is fixed at 63°, by comparing the influence of the ratio of the height of the transparent layer 12 to the side length of the rectangular thin layer on the angle color-changing effect, the results show that when the ratio of the height of the transparent layer 12 to the side length of the rectangular thin layer is in the range of 0.75 - 1.2, the angle color-changing effect is better and the smoothness of the angle color change is more excellent. After the inclined surface angle or the thickness (height) of the transparent layer is further increased, the angle color change of the prepared color-changing material becomes unsmooth.

[0049] In order to simulate the dynamic color of the concave multi-layer structure of the Papilio genus from a macroscopic perspective, the size of the model unit 10 is optimized. Finally, the aspect ratio of the length to the width of the rectangular thin layer is determined to be 1:0.95 - 1.05, more preferably a square, and the side length is 2.5 mm - 6 mm. The concave space in the transparent layer 12 is not filled with any material, and together with the transparent layer, it plays the role of a refraction and diffraction grating to achieve the angle color-changing effect of simulating the Papilio butterfly wings. The thickness range of the transparent layer 12 is 1.88 mm - 6.75 mm, and the thickness of the color information layer 11 is 0.25 mm - 0.6 mm. There is no special limitation on the thickness of the color information layer 11, as long as it can be printed by 3D printing and carry pigment color information. The length and width of the entire model unit 10 are the same as those of the rectangular thin layer, and the height of the model unit 10 is 2.13 mm - 7.35 mm. By comparing the 3D printing effects of the model units designed with different size ranges and ratios, the angle color-changing effect of the color-changing material finally printed by the model unit that meets the above range is the best, and the smoothness of the angle color-changing effect is the best, while the specific shape of the concave space can have different deformations.

[0050] When the size of the model unit 10 is too small compared to the above range, it will cause the preparation difficulty of the angle-changing color material to increase exponentially, the precision requirement to be too high, the preparation process to be difficult to control, and the color display effect of the product to be poor. When the scale of the model unit 10 exceeds the above range, it will lead to poor smoothness of the angle-changing color phenomenon, poor angle-changing color effect, and obvious discontinuity in color display. In practical applications, it can be adjusted within this range according to the color display effect. In practical applications, the distribution and proportion of the transparent layer 12 and the color information layer 11 in the model unit can also be optimized. Through optimization, the interaction of light between different layers can be further accurately controlled to achieve the purpose of simulating the angle-changing color phenomenon of the concave multi-layer structure.

[0051] Example 2

[0052] This example provides a preparation method of a color-changing material based on the angle-changing color mechanism of the concave multi-layer structure of Papilio butterflies, which includes the following steps:

[0053] (1) Model and form an array according to the model unit 10 shown in Figure 3 (a), (b), and (c) of Example 1 to obtain an angle-changing color model based on the concave multi-layer structure of Papilio butterflies. Among them, the aspect ratio of the rectangular thin layer (color information layer 11) is 1:1, the side length is 4 mm, the angles between the inclined planes of the concave space and the color information layer 11 are 45°, 63°, and 70° respectively, the thickness of the transparent layer 12 is 1.5 mm, 3.0 mm, 4.5 mm, and the thickness of the color information layer 11 is 0.4 mm.

[0054] (2) Use the Stratasys full-color 3D printing technology to print and form the dark blue and light blue parts in the color information layer 11 with a colored photosensitive polymer material, and print and form the transparent layer 12 with a transparent photosensitive polymer material with a refractive index of 1.56. After 3D printing is completed, it is irradiated under UV light of 500 W for 3 min for curing and shaping to obtain a color-changing material based on the angle-changing color mechanism of the concave multi-layer structure of Papilio butterflies. The physical photos of the prepared color-changing material are as shown in Figure 4 (a), (b), and (c).

[0055] Example 3

[0056] This example is different from the angle-changing color model based on the concave multi-layer structure of Papilio butterflies finally constructed in Example 1. The main difference is that the rectangular thin layer of the color information layer 11 is divided into four blocks. The four blocks are filled with different pigments respectively or the four blocks are filled with two pigment colors in an interleaved manner.

[0057] As shown in Figure 5As shown in (a), the rectangular thin layer of the color information layer 11 of the model unit 10 is evenly divided into four blocks by two diagonals. The first block is filled with dark blue, the second block adjacent to it is filled with light blue, the third block adjacent to the second block is filled with dark blue, and the fourth block adjacent to it is filled with light blue. As Figure 5 As shown in (b), the rectangular thin layer of the color information layer 11 of the model unit 10 is evenly divided into four blocks by two diagonals. The first block is filled with dark blue, the second block adjacent to it is filled with light blue, the third block adjacent to the second block is filled with dark blue, and the fourth block adjacent to it is filled with light blue.

[0058] After obtaining Figure 5 the model unit 10 shown in (b), there are two ways of the array arrangement of the model unit 10: As Figure 6 shown in (a), the blocks with the same color of the color information layer 11 are arranged adjacent to each other in an array continuous arrangement; or, as Figure 6 shown in (b), the blocks with different colors of the color information layer are arranged adjacent to each other in an array continuous arrangement. Specifically, it can be adjusted according to the angle color change effect.

[0059] In other embodiments, among the above four blocks, 3 / 4 of the blocks can also be filled with one pigment color, and the remaining 1 / 4 can be filled with another pigment color. Specifically, according to the color display effect, different pigment colors can be filled in according to the designed ratio.

[0060] In other embodiments, the rectangular thin layer of the color information layer 11 can be further divided into 8 or even 16 blocks. These blocks are arranged radially outward from the center hole 110 of the rectangular thin layer. These blocks are filled with two pigment colors in an interleaved manner.

[0061] Embodiment 4

[0062] This embodiment is different from the angle color change model based on the Papilio genus concave multi-layer structure finally constructed in Embodiment 1. The main difference lies in: the number of layers of the transparent layer 12 is different.

[0063] As Figure 7 shown in (a), in this embodiment, the transparent layer 12 includes a plurality of stacked sub-layers 121, and the ratio of the total height of the transparent layer to the side length of the rectangular thin layer is in the range of 0.75 - 1.2. The side length of a single model unit 10 is controlled within 6 mm - 2.5 mm (the same as the length and width of the bottom color information layer 11). Among them, as Figure 7As shown in (a), the inclined surface of the concave space in this embodiment is multi-segmented, and the angles of each segment of slope are the same or different. At this time, concave spaces are respectively formed in the middle of each sub-layer 121 in the transparent layer 12, and are arranged in the following manner in the order from bottom to top: the first sub-layer is recessed from the surface towards the central hole 110 of the rectangular body thin layer to form a first concave space in the shape of a frustum of a pyramid; the second sub-layer is recessed from the surface towards the first concave space to form a second concave space in the shape of a frustum of a pyramid. According to this rule, the third sub-layer is recessed from the surface towards the second concave space to form a third concave space in the shape of a frustum of a pyramid. Among them, the included angles between the peripheral inclined surfaces of the concave spaces of each sub-layer and the horizontal plane where the rectangular body thin layer is located are different. When the included angles between the peripheral inclined surfaces of the concave spaces of each sub-layer and the horizontal plane where the rectangular body thin layer is located are the same, then these stacked sub-layers 12 can be regarded as a continuous transparent layer 12.

[0064] When the ratio of the total thickness of the transparent layer of the model unit 10 to the color information layer 11 is set to 1.2, the included angle between the inclined surface of the concave space corresponding to the first sub-layer and the color information layer 11 is set to 75°, and the color information layer 11 is a square with a side length of 5.6 mm, the pigment colors of the color information layer 11 are arranged in the manner of Figure 7 (a). After being printed by photosensitive material 3D printing in the manner of Embodiment 2, the material color display effect is as shown in Figure 7 (b). If the ratio of the total thickness of the transparent layer to the color information layer 11 or the inclined surface angle is continuously increased, it will cause a delay in the angle color change effect of the material.

[0065] Embodiment 5

[0066] This embodiment is different from the angle color change model based on the concave multi-layer structure of the genus Papilio finally constructed in Embodiment 1. The main difference lies in: the three-dimensional shape of the concave space in the middle of the transparent layer 12 is different. As shown in Figure 8 (b), the side wall of the concave space is a convex octagonal cone, the horizontal cross-section of the concave space is an octagon, and the transparent layer 12 of the model unit 10 has four sharp corners.

[0067] As shown in Figure 8 (a) of, the three-dimensional shape of the concave space in the middle of the transparent layer 12 is "cross-shaped", the horizontal cross-section of the concave space is a cross composed of twelve sides, and the four sharp corners of the transparent layer 12 are respectively intercepted by a plane with an included angle of about 2 - 5° with the horizontal plane to form an inclined surface with an included angle of 2 - 5° with the horizontal plane. When the cross-shaped concave space is at the bottom, the width of the cross surface is the smallest and converges into two cross-shaped intersecting line segments. As it gradually approaches the top of the concave space from the bottom, the width of the cross surface increases. Therefore, as shown in Figure 8 (a) of the model unit, its concave space is a three-dimensional shape composed of several cross shapes that gradually increase from bottom to top.

[0068] Material forming effect: When the included angle between the inclined plane of the concave space of the model unit and the color information layer 11 is set to 63°, and the ratio of the total thickness of the transparent layer 12 to the color information layer 11 is set to 0.84, when the color information layer 11 is a square with a side length of 4 mm, the pigment color of the color information layer 11 is arranged according to Figure 8 the ways of (a) and (b) in. After being 3D printed with photosensitive materials in the manner of Embodiment 2, the material color display effects are respectively as Figure 8 shown in (c) and (d) in. It can be seen from the figure that compared with the foregoing embodiments, it is found that the inclined planes of the concave space around the central hole position are generally even numbers, the three-dimensional shape of the concave space is a centrosymmetric body, and the more the number of inclined planes, the more colors are reflected. The angle color-changing effect is slightly worse than that of Embodiment 1. However, at the same time, this embodiment can endow the material with a crystal-clear visual appearance while enabling the material to have an angle color-changing effect similar to that of a Papilio memnon. In production applications, the specific shape of the model unit can be selected according to the color display requirements of the product.

[0069] In other embodiments, the transparent layer 12 is recessed towards the central hole position 110 of the rectangular thin layer to form a concave space in the shape of a convex octahedron or a cross, and the inclined planes of the concave space are composed of multiple connected inclined planes from bottom to top, and the inclined angles of each connected inclined plane with the color information layer 11 are different or the same.

[0070] In summary, aiming at the current situation that it is difficult to prepare a single structural color material with an angle color-changing effect, with high operation precision, strong professional requirements, and the difficulty in obtaining high-precision equipment and expensive materials, the present invention constructs an angle color-changing model based on the concave multi-layer structure of the Papilio genus. By planning the layout of the color information layer 11, adjusting the thickness of the transparent layer 12 and the shape and parameters of the concave space, the simulation of the angle color-changing phenomenon of the concave multi-layer structure of the Papilio genus is realized. The main contents of the present invention include the construction of a digital model, the optimization of the model structure parameters, and the integrated preparation technology of a simulated Papilio genus concave structure dynamic angle color-changing material based on full-color 3D printing. Among them, through the layout planning of the color information layer 11, the color phenomenon of the dynamic change of the structural color of the concave multi-layer structure of the Papilio genus is simulated. The model design of the color information layer 11 takes into account the mixing and superposition optical effects of the pigment color and the transparent layer 12 during the arrangement of the color array, so as to realize the simulation of the color-changing phenomenon at a specific angle. Compared with the prototype of the multi-layer concave structure of the Papilio genus, the thickness of the transparent layer 12 and the shape of the concave space that play an optical effect are simplified and redesigned during the modeling process, achieving the effect of influencing the propagation path of light in the multi-layer structure, and expanding the length and width of the model unit to the range of 2.5 mm - 6 mm, greatly reducing the technical difficulty and reducing material consumption. In addition, in the foregoing embodiments, the model unit with a concave space in the shape of a frustum of a pyramid constructed in Embodiments 1-2 has the optimal angle color-changing effect after being formed by 3D printing. Especially when the inclined plane angle is 60-70 degrees, the angle color-changing effect of the material is the smoothest.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements, or when the technical features in the above embodiments do not conflict with each other, can be combined in the manner described in the embodiments, and these modifications, replacements or combinations do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An angle color-changing model based on the concave multi-layer structure of the Papilio genus, characterized in that, It includes: A plurality of model units arranged in an array, each model unit comprising a color information layer and a transparent layer, the transparent layer being covered and combined above the color information layer; the color information layer comprises a rectangular thin layer, and a central hole is provided at the geometric center position of the rectangular thin layer; the rectangular thin layer is divided into an even number of blocks, and pigment colors are filled in the blocks, and at least two different pigment colors are included in the pigment colors on the rectangular thin layer; The transparent layer is recessed from the surface towards the central hole of the rectangular thin layer to form a three-dimensional recessed space, the three-dimensional recessed space comprises a plurality of inclined surfaces, and the inclined surfaces are arranged radially away from the center with the central hole as the center, and the recessed space is centrosymmetric about an axis perpendicular to and passing through the central hole; the included angle between the inclined surface in contact with the rectangular thin layer and the plane where the rectangular thin layer is located is 45°-75°; wherein, the ratio of the total thickness of the transparent layer to the width of the rectangular thin layer ranges from 0.75 to 1.

2.

2. The angle color-changing model based on the concave multi-layer structure of the Papilio genus according to claim 1, wherein In the model unit, the aspect ratio of the length to the width of the rectangular thin layer is 1:0.95-1.05, the length and width of the model unit are 2.5 mm-6 mm, the height of the model unit is 2.13 mm-7.35 mm, and the thickness of the rectangular thin layer is 0.25 mm-0.6 mm; the included angle between the inclined surface in contact with the rectangular thin layer and the plane where the rectangular thin layer is located is 60°-75°.

3. The angle color-changing model based on the concave multi-layer structure of the Papilio genus according to claim 1, wherein The number of the inclined surfaces is an even number, the area of the central hole accounts for 4 / 64-9 / 64 of the area of the rectangular thin layer, and the inside of the central hole is empty.

4. The angle color-changing model based on the concave multi-layer structure of the Papilio genus according to claim 1, characterized in that, The rectangular thin layer of the color information layer is divided into two blocks by a diagonal line, and different pigment colors are filled in the two blocks respectively; or the rectangular thin layer of the color information layer is divided into two blocks by the midline of one side, and different pigment colors are filled in the two blocks respectively.

5. The angle color-changing model based on the concave multi-layer structure of the Papilio genus according to claim 1, characterized in that, The rectangular thin layer of the color information layer is divided into four blocks by two intersecting diagonal lines, and two pigment colors are filled in the four blocks in a staggered manner; or the rectangular thin layer of the color information layer is divided into four blocks by the midlines of two adjacent sides, and two pigment colors are filled in the four blocks in a staggered manner.

6. The angle color-changing model based on the concave multi-layer structure of the Papilio genus according to claim 1, characterized in that, In the angle-changing color model based on the Papilio genus concave multi-layer structure, a plurality of model units are arranged in an array in a continuous manner with the blocks of the color information layer having the same color adjacent to each other; or, a plurality of model units are arranged in an array in a continuous manner with the blocks of the color information layer having different colors adjacent to each other.

7. The angle color-changing model based on the concave multi-layer structure of the Papilio genus according to claim 1, wherein The transparent layer is only one layer, and the transparent layer is recessed from the surface towards the central hole of the rectangular thin layer to form a recessed space in the shape of a frustum of a pyramid, and the four surfaces of the recessed space are inclined surfaces of isosceles trapezoids, the included angle between the inclined surface and the horizontal plane where the rectangular thin layer is located is 45°-75°, and the center of the bottom surface of the recessed space is aligned with the central hole of the rectangular thin layer in the vertical direction.

8. The angle color-changing model based on the Papilio genus concave multi-layer structure according to claim 1, characterized in that The transparent layer comprises a plurality of stacked sub-layers, and a recessed space is respectively formed in the middle of each transparent layer, and the order from bottom to top is set as follows: the first sub-layer is recessed from the surface towards the central hole of the rectangular thin layer to form a first recessed space in the shape of a frustum of a pyramid; The second sub-layer is recessed from the surface towards the first recessed space to form a second recessed space in the shape of a frustum of a square pyramid. According to this rule, the nth transparent layer is recessed from the surface towards the (n - 1)th recessed space to form the nth recessed space in the shape of a frustum of a square pyramid; the included angles between the inclined surfaces around the recessed spaces of each sub-layer and the horizontal plane where the rectangular thin layer is located are the same or different.

9. The angle color-changing model based on the concave multi-layer structure of the Papilio genus according to claim 1, characterized in that, The side wall of the recessed space is a convex octahedral cone or a cross shape, and the horizontal cross-section of the recessed space is a convex octagon or a cross shape composed of twelve sides.

10. A preparation method of a color-changing material based on the angle color-changing mechanism of the Papilio concave multi-layer structure, characterized in that, It includes the following steps: Modeling is carried out according to the angle-changing color model based on the Papilio genus recessed multi-layer structure described in any one of claims 1-9; then, using the Stratasys 3D inkjet voxel printing technology, the color information layer is printed and formed with a colored photosensitive polymer material, and the transparent layer is printed and formed with a transparent photosensitive polymer material; After printing, it is cured under UV light to obtain the color-changing material based on the angle-changing color mechanism of the Papilio recessed multi-layer structure.

11. A color-changing material based on the angle color-changing mechanism of the Papilio concave multi-layer structure, characterized in that, The material is prepared by the preparation method of claim 10 above; the refractive index of the transparent photosensitive polymer material is 1.55 - 1.60.

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