Color-changing pigment composition

Abstract

The invention provides a color-changing pigment composition. The color-changing pigment composition comprises a first pigment and a second pigment, wherein the first pigment comprises at least one optical color-changing pigment which changes color along with the angle; the second pigment comprises at least one structural color pigment capable of generating scattering color; wherein the first pigment and the second pigment are configured such that under ambient light, when the observation angle is parallel to the normal direction of the main surface of the color-changing pigment composition, the first pigment and the second pigment present the same color, and when the observation angle deviates from the normal direction of the main surface of the color-changing pigment composition, the first pigment and the second pigment present the same color. The colors presented by the first pigment and the second pigment are the same or different; under the inclined irradiation of the strong light source, the second pigment presents a scattering color, and the first pigment does not have the scattering color. The optically variable pigment composition has multiple anti-counterfeiting functions, the authenticity identification method is simple, and the optically variable pigment composition is extremely difficult to counterfeit.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of anti-counterfeiting technology, in particular to a color-changing pigment composition. BACKGROUND

[0002] Optical color-changing pigments are a kind of high-end anti-counterfeiting pigments that have attracted much attention in the market in recent years. The optical color-changing anti-counterfeiting technology is based on the goniochromatic effect of optical multilayer film multi-beam interference. Under the condition of changing the incident angle, the reflected light beam changes due to the change of the equivalent optical path with the angle, resulting in the shift of the reflection spectrum and thus the color effect changes with the change of the observation angle, thereby producing the color-changing effect. This color-changing effect cannot be reproduced by ordinary scanning / copying. In recent years, with the progress of the production technology of optical color-changing pigments and the continuous improvement of the production process, the application of optical color-changing anti-counterfeiting pigments has been expanded.

[0003] The present inventors have found in a long-term research process that although the structure of the existing optical color-changing material achieves the optical color-changing effect, the effect is relatively single and has been used for many years, and it is easy to be counterfeited. SUMMARY

[0004] The present application provides a color-changing pigment composition to solve the technical problem in the prior art that the effect of the optical color-changing material is single and easy to be counterfeited.

[0005] To solve the above technical problems, one technical solution adopted by the present application is to provide a color-changing pigment composition, which comprises a first pigment and a second pigment, the first pigment comprises at least one goniochromatic optical color-changing pigment, and the second pigment comprises at least one structural color pigment capable of producing a scattering color; wherein the first pigment and the second pigment are configured such that, under ambient light, when the observation angle is parallel to the normal direction of the main surface of the color-changing pigment composition, the colors presented by the first pigment and the second pigment are the same, and when the observation angle deviates from the normal direction of the main surface of the color-changing pigment composition, the colors presented by the first pigment and the second pigment are the same or different; under the oblique illumination of a strong light source, the second pigment presents a scattering color, and the first pigment does not have a scattering color.

[0006] In some embodiments, the film system structure of the goniochromatic optical color-changing pigment is a Fabry-Perot interference cavity structure.

[0007] In some embodiments, the second pigment comprises at least one goniochromatic optical color-changing pigment and at least one structural color pigment capable of producing a scattering color, and the film system structure of the structural color pigment capable of producing a scattering color is a Fabry-Perot interference cavity structure and a plurality of metal nanoparticles arranged on the outer surface of the Fabry-Perot interference cavity structure.

[0008] In some embodiments, the material of the metal nanoparticles includes at least one of silver, gold, copper, platinum, ruthenium, palladium, rhodium, cobalt, iron, nickel, and lead or an alloy of at least two thereof.

[0009] In some embodiments, under ambient light, when the observation angle is parallel to the normal direction of the major surface of the color-changing pigment composition, the color difference value presented by the first pigment and the second pigment is not greater than 4, wherein the colors presented by the first pigment and the second pigment are overall colors calculated according to the Lab color space.

[0010] In some embodiments, in the structural color pigments, the mass percentage of the scattering color structural color pigments that can be produced is not less than 50%.

[0011] In some embodiments, under dimmer ambient light, the color-changing pigment composition is irradiated by a strong light source at an oblique angle so that the second pigment presents a scattering color, wherein the illuminance value of the dimmer ambient light is less than or equal to 2000 lx.

[0012] In some embodiments, the strong light source is a strong white light, and the illuminance value of the strong light source is greater than or equal to 3000 lx.

[0013] In some embodiments, the oblique incidence angle of the strong light source is 30°-85°.

[0014] In some embodiments, the first pigment and the second pigment are printed in superposition, wherein the second pigment is superimposed on the first pigment.

[0015] The beneficial effects of the embodiments of the present application are as follows: Different from the prior art, the color-changing pigment composition of the present application includes a first pigment and a second pigment, the first pigment includes at least one goniochromatic optically variable pigment, and the second pigment includes at least one structural color pigment that can produce a scattering color; wherein under ambient light, when the observation angle is parallel to the normal direction of the major surface of the color-changing pigment composition, the colors presented by the first pigment and the second pigment are the same, and when the observation angle deviates from the normal direction of the major surface of the color-changing pigment composition, the colors presented by the first pigment and the second pigment are the same or different; under the oblique irradiation of a strong light source, the second pigment presents a scattering color, and the first pigment does not have a scattering color. The color-changing pigment composition of the present application combines different pigments, which combines the two anti-counterfeiting mechanisms of "angle color change" and "scattering appearance", to form a combined pattern and improve the anti-counterfeiting effect. The second pigment can be hidden in the first pigment and does not show a scattering color in a normal view, so it is not easy to be found, and can show a scattering color under the oblique irradiation of a strong light source, so that the user can easily complete the true and false identification. The use of the color-changing pigment composition of the present application is simple and economical in the true and false identification process, and the second pigment has an extension change effect of display / hiding, which is extremely difficult to imitate. BRIEF DESCRIPTION OF DRAWINGS

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of a color-changing pigment composition provided in this application;

[0018] Figure 2 This is a schematic diagram of the frontal structure of a pattern formed by a color-changing pigment composition provided in this application under ambient light.

[0019] Figure 3 yes Figure 2 The pattern shown is a side view of the structure under ambient light.

[0020] Figure 4 yes Figure 2 The pattern shown is a schematic diagram of its structure when illuminated at an angle by a strong white light source;

[0021] Figure 5 This is a schematic diagram of the frontal structure of a pattern formed by another color-changing pigment composition provided in this application under ambient light.

[0022] Figure 6 yes Figure 5 The pattern shown is a schematic diagram of the structure when illuminated at an angle by a strong white light source. Detailed Implementation

[0023] The present application will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present application, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the scope of protection of this application.

[0024] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0025] In today's society, counterfeit and substandard goods flood the market, disrupting normal market order and infringing upon the rights of consumers and the economic interests of manufacturers. To prevent and combat the production and sale of counterfeit goods, various anti-counterfeiting technologies have been researched and developed. In recent years, optically variable pigments have been widely used in high-end anti-counterfeiting fields.

[0026] Optical color-changing pigments possess strong interference colors and cannot be scanned or copied. They have been adopted by most countries and are widely used for anti-counterfeiting of valuable items and for protecting important information and documents. In recent years, they have also gradually penetrated the civilian anti-counterfeiting market. After years of development, the optical color-changing pigment industry is currently experiencing severe product homogenization. Even if new colors, higher color saturation, or brightness appear on the market, competing companies can easily imitate them after obtaining samples. With technological advancements, single anti-counterfeiting technologies are easier to counterfeit, and anti-counterfeiting technologies are trending towards more complex and multifaceted approaches.

[0027] Based on this, this application provides a color-changing pigment composition that forms a combination pattern through different pigments, which has a good anti-counterfeiting effect and is not easy to be counterfeited.

[0028] Please see Figure 1 As shown, Figure 1 This is a schematic diagram of an embodiment of a color-changing pigment composition provided in this application. Specifically, the color-changing pigment composition 10 includes a first pigment 11 and a second pigment 12.

[0029] The first pigment 11 includes at least one optically variable pigment that varies with angle, and the second pigment 12 includes at least one structural pigment capable of producing scattered colors. Specifically, under ambient light, when the viewing angle is parallel to the normal direction of the main surface of the pigment composition 10, the first pigment 11 and the second pigment 12 exhibit the same color; when the viewing angle deviates from the normal direction of the main surface of the pigment composition 10, the first pigment 11 and the second pigment 12 exhibit the same or different colors. Under oblique illumination from a strong light source, the second pigment 12 exhibits scattered colors, while the first pigment 11 does not.

[0030] Specifically, the first pigment 11 may include one or more optically variable pigments that change color with angle. The first pigment 11 is characterized by its angle-dependent color-changing property. That is, as the viewing angle changes, the color perceived by the human eye undergoes a continuous and reversible shift. The angle-dependent color-changing effect inherent in the first pigment 11 constitutes the first line of defense against counterfeiting.

[0031] The second pigment 12 includes at least one structural pigment capable of producing scattered colors. The second pigment 12 can be a single scattering pigment or a combination of scattering and interference pigments.

[0032] The second pigment 12 can possess dual properties, functioning as both an optically variable pigment and a scattering material. Under ambient light, the second pigment 12 exhibits a dominant reflective color. To achieve visual concealment between the second pigment 12 and the first pigment 11, its reflectance spectrum (especially its frontal color) in this mode can match that of the first pigment 11, ensuring indistinguishability to the human eye under normal observation conditions. When illuminated by high-intensity, directional white light at an angle, the second pigment 12 can display a new color, namely a scattered color. This scattered color differs from both its frontal and lateral colors. The second pigment 12 can produce scattered light of sufficient intensity, clearly distinguishable from the reflective color of the first pigment 11. This "scattered light" does not belong to the normal reflective light sequence, providing an additional, decisive criterion for authenticity verification, thus increasing the dimension of identification.

[0033] After forming a combined pattern using the aforementioned color-changing pigment composition 10, under ambient light, when an observer looks directly at the pattern, the reflected light from both the first pigment 11 and the second pigment 12 can be seen by the human eye. Simultaneously, the scattered light produced by the second pigment 12 can also be collected by the human eye. However, since the reflected light is significantly stronger than the scattered light, the color of the second pigment 12 is dominated by the reflected light. Because the first pigment 11 and the second pigment have similar frontal colors, the human eye can only see one combined pattern at this time and cannot distinguish between the first pigment 111 and the second pigment 12. When a strong light source is incident obliquely on the combined pattern, and the human eye and the light source are close and on the same normal side, the reflected light cannot be collected by the human eye because it exits from the other end of the normal. However, because the second pigment 12 can produce 360-degree spatially dispersed scattered light that can be collected by the human eye, the pattern can then be "displayed." Under both observation methods, the pattern seen by the human eye switches back and forth between the frontal color pattern and the scattered light pattern of the second pigment.

[0034] The above embodiments seamlessly integrate two advanced anti-counterfeiting technologies, angle-dependent color variation and strong photoscattering, into a single pattern. This composite anti-counterfeiting pattern is difficult to replicate and offers superior anti-counterfeiting effectiveness. Furthermore, under normal conditions, the anti-counterfeiting features of the second pigment 12 are hidden and invisible. This differs from traditional "visible" anti-counterfeiting marks, making it impossible for counterfeiters to detect the existence of complete anti-counterfeiting information during imitation, thus hindering their ability to counterfeit.

[0035] Alternatively, the strong light source can be a strong white light source, such as a flashlight, mobile phone light, or a desk lamp.

[0036] Optionally, the film structure of the angle-dependent color-changing pigment in the first pigment 11 can be a Fabry-Perot interferometer cavity structure. The color of this structure is produced by the selective reflection of specific wavelengths of light through the interference of incident light by its precise multilayer thin film structure. This structure constructs an optical resonant cavity, ensuring that only light waves satisfying the constructive interference condition are strongly reflected, thereby achieving pure colors with high color saturation and high brightness. For example, the first pigment 11 can be a symmetrical film structure of an absorption layer / dielectric layer / reflective layer / dielectric layer / absorption layer.

[0037] Optionally, the second pigment 12 may include at least one angle-dependent color-changing pigment and at least one structural pigment capable of producing scattered colors. The film structure of the structural pigment capable of producing scattered colors includes a Fabry-Perot interferometer structure and several metal nanoparticles disposed on the outer surface of the Fabry-Perot interferometer structure.

[0038] In the above embodiments, the second pigment 12 is a mixture of scattering and interference pigments. The film structure of the structural pigment in the second pigment 12 may include a Fabry-Perot interference cavity structure and metal nanoparticles disposed on the outer surface of the Fabry-Perot interference cavity structure. The second pigment 12 can utilize the interference effect of the film layer and the enhancement effect of the metal nanoparticles on scattered light to achieve not only an angle-dependent color-changing effect under ambient light but also different color changes under strong light. The angle-dependent interference pigment in the second pigment 12 serves to adjust the color, thereby aligning the frontal color of the second pigment 12 to the same level as the first pigment 11, thus increasing the concealment effect of the second pigment 12.

[0039] It should be noted that the aforementioned structural color pigments with metal nanoparticles exhibit enhanced selective wavelength scattering of incident light under strong white light, such as mobile phone light. This phenomenon is caused by a localized surface plasmon resonance (LSPR) phenomenon. LSPR is an optical phenomenon in which metal nanoparticles smaller than the wavelength of light absorb light. Under incident light, the electron cloud within the metal nanoparticle redistributes and polarizes, creating positive and negative electron clouds. When the polarization direction of the incident light is parallel to the line connecting two metal nanoparticles, the positive and negative electron clouds are distributed at the left and right ends of the nanoparticles, respectively. The opposite charges accumulated on the particle surfaces on both sides of the gap generate a strong electromagnetic field; this point is called a "hot spot." This "hot spot" region strongly enhances the scattering of incident light, and the scattering spectrum has certain peaks and troughs, causing the material's color to change under high-intensity light. Since what is observed by the naked eye under high light is mainly the scattered light from the material, the color change can be seen without finding a specific viewing angle.

[0040] The materials of metal nanoparticles may include at least one or an alloy of at least two of silver, gold, copper, platinum, ruthenium, palladium, rhodium, cobalt, iron, nickel, and lead.

[0041] Metal nanoparticles can be of any shape, such as spheres, hemispheres, ellipsoids, cubes, cuboids, octahedrons, dodecahedrons, hexahedrons, cylinders, stars, pyramids, triangular prisms, cylindrical shapes, and other irregular shapes. The size of the metal nanoparticles 124 ranges from 5 nm to 1 μm, for example, 5 nm, 10 nm, 50 nm, 100 nm, 500 nm, or 1 μm.

[0042] It is understood that the shape of the metal nanoparticles can be uniformly the same, such as all being spheres or all being hemispheres. In other embodiments, the metal nanoparticles may also be a mixture of multiple shapes, and the specific selection and setting can be made according to the actual situation, without being specifically limited here.

[0043] In other embodiments, the structural color pigments that can generate scattering colors may also include structural color pigments based on photonic crystals, structural color pigments based on dielectric nanoparticles, or thin film interference pigments based on special morphologies.

[0044] Optionally, under ambient light, when the viewing angle is parallel to the normal direction of the main surface of the color-changing pigment composition 10, the color difference value of the first pigment 11 and the second pigment 12 is no greater than 4, wherein the color of the first pigment 11 and the second pigment 12 is the overall color calculated according to the Lab color space.

[0045] The color difference value here refers to the overall color difference value calculated based on the Lab color space. The smaller the color difference value, the more similar the two colors are. The larger the color difference value, the more obvious the difference between the two colors. A color difference value of no more than 4 indicates that the color difference between the first pigment 11 and the second pigment 12 is small, and the observer cannot clearly perceive the difference in color. This allows the second pigment 12 to be hidden within the first pigment 11.

[0046] Optionally, in the structural color pigment, the mass percentage of metal nanoparticles is not less than 50%.

[0047] Metal nanoparticles act as scattering centers, and their scattering cross-section and scattering intensity are directly related to the particle concentration and total volume. A mass fraction of not less than 50% means that there are sufficiently high-density metal nanoparticles in the pigment particles to cause scattering.

[0048] With the above-mentioned proportions, the second pigment 12 can produce strong and bright scattered light when excited by a strong light source. This allows the hidden pattern to be clearly and accurately revealed during identification, and the scattered light signal can be easily captured by the naked eye even under conditions of ambient light interference.

[0049] A high proportion of metallic nanoparticles can make the intensity of scattered light as much as possible to suppress the residual stray reflected light, so that the color observed by the human eye is a pure and saturated "scattered color", creating a strong "hidden to revealed" dynamic effect.

[0050] Optionally, under relatively dim ambient light, a strong light source is used to obliquely irradiate the color-changing pigment composition 10 so that the second pigment 12 exhibits a diffused color, wherein the illuminance value of the relatively dim ambient light is less than or equal to 2000 lx.

[0051] Whether the human eye can see the scattered color of the second pigment 12 depends on the ratio of the scattered light signal to the background noise (signal-to-noise ratio). The background noise mainly comes from two parts: the residual reflected light from the first pigment 11 and the second pigment 12; and the interference from ambient light.

[0052] When the ambient light illuminance is less than or equal to 2000 lx, ambient light interference is reduced to a low level, preventing ambient light from interfering with scattered light. 2000 lx is approximately equivalent to bright indoor lighting, meaning that authentication can be performed in most indoor environments without absolute darkness, thus improving the convenience of anti-counterfeiting authentication.

[0053] Optionally, the strong light source is strong white light, with an illuminance value greater than or equal to 3000 lx. In the second pigment 12, the metal nanoparticles (scattering centers) need to reach a certain energy threshold to be effectively excited and produce sufficiently intense scattered light. 3000 lx is an optimal value verified by experiments. A strong light source with this illuminance can initiate illumination with efficient scattering, and the visualization effect of the second pigment 12 is quite obvious.

[0054] When the ambient light illuminance is no greater than 2000 lx and the illuminance of the strong light source is no less than 3000 lx, it means that the signal strength of the strong light source is at least 1.5 times the noise level. This allows the scattered colors to stand out clearly and distinctly from the background, making them easily captured by the human eye and reducing the likelihood of ambiguous or unclear identification results.

[0055] Optionally, the angle of incidence of the strong light source is 30°-85°. According to the law of optical reflection, when light is incident at a large angle (not less than 30°), the specular reflection light generated from the interference cavity surfaces of the first pigment 11 and the second pigment 12 will be reflected at the same large angle to the other side of the normal. Since the human eye is required to be on the same side of the normal as the light source, this angle range ensures that the observer cannot receive the specular reflection light. This causes the reflected colors of the first pigment 11 and the second pigment 12, which depend on reflected light for color rendering, to disappear from the observer's field of vision, reducing background interference for the rendering of scattered light.

[0056] Optionally, the first pigment 11 and the second pigment 12 are overprinted, wherein the second pigment 12 is overprinted on the first pigment 11.

[0057] When the second pigment 12 is overlaid on the first pigment 11, under ambient light, the light must first penetrate the second pigment 12, then be reflected by the first pigment 11, and finally pass through the second pigment 12 again before entering the human eye. By precisely controlling the concentration and coverage of the ink in the second pigment 12, the mixed color can be made infinitely close to the color of the pure first pigment 11. This allows the hidden pattern of the second pigment 12 to be well concealed within the background pattern formed by the first pigment 11, achieving a high level of visual camouflage. Under the oblique illumination of a strong light source, the reflected light from the first pigment 11 is avoided. At this time, the excitation light acts directly on the outermost layer of the second pigment 12, exciting strong scattered light. Since the second pigment 12 is located on top, the scattered light it produces does not need to penetrate any other pigment layers and enters the human eye directly. Thus, the brightness loss of the scattered color is small, and the color saturation is high, resulting in a vivid and dazzling display effect.

[0058] Furthermore, compared to "overprinting," which requires precise alignment, "overprinting" offers greater tolerance for errors. As long as the second pigment 12 is printed completely within a specific area of ​​the first pigment 11, there is no need to worry about minor misalignments at the edges causing the outline of the hidden pattern to be exposed under normal light. This improves production efficiency and product yield.

[0059] For example, the color-changing pigment composition provided in this application will be described below.

[0060] First Embodiment

[0061] The first pigment 11 is a fully dielectric photochromic pigment with a Fabry-Perot interferometer cavity structure, and the second pigment 12 is a scattering structural color pigment with a Fabry-Perot interferometer cavity structure and surface-loaded noble metal nanoparticles. Both pigments have similar front and side colors, exhibiting photochromic characteristics of green when viewed from the front and blue when viewed from the side. The two pigments are then combined and printed using an overprinting method. The ink addition of the first pigment 11 is 15wt%, and a large "100" pattern is screen-printed. The ink addition of the second pigment 12 is 5-10wt%, and a smaller "100" pattern is printed within the larger "100" pattern using an overprinting method. Because the front colors of the two pigments are similar, the smaller "100" pattern is well hidden within the larger "100" pattern. Figure 2 and Figure 3 As shown, under ambient light, only the large "100" pattern is visible, appearing green when viewed directly and blue when viewed from the side; the second pigment, 12, is hidden. However, under the light of a mobile phone or a flashlight at an angle, as... Figure 4 As shown, the scattered light emitted by the small "100" pattern is dominant, so it can be displayed well, and the color is the third color—the scattered yellow.

[0062] Second Embodiment

[0063] The first pigment 11 is a fully dielectric photochromic pigment with a Fabry-Perot interferometer cavity structure, and the second pigment 12 is a scattering structural color pigment with a Fabry-Perot interferometer cavity structure and surface-loaded noble metal nanoparticles. Both pigments have similar front and side colors, exhibiting photochromic characteristics of green when viewed from the front and blue when viewed from the side. The two pigments are then combined and printed using an overprinting method. The ink addition amount of the first pigment 11 is 15wt%, and a lotus leaf pattern is screen-printed. The ink addition amount of the second pigment 12 is 5-10wt%, and a lotus flower pattern is printed within the lotus leaf pattern using an overprinting method. Figure 5 As shown, because the two pigments are similar in color when viewed directly, the lotus flower pattern is well hidden within the lotus leaf pattern; under ambient light, only the lotus leaf pattern is visible. However, under the light of a mobile phone / flashlight at an angle, as... Figure 6 As shown, the lotus pattern is well-displayed because the diffused light emitted by the lotus flower dominates the display, and its color is the third color—the diffused yellow. The lotus pattern's transformation from "hidden" to "revealed" under strong white light perfectly embodies the meaning of "flowers blooming in the light."

[0064] In summary, the color-changing pigment composition 10 of the above embodiments combines two anti-counterfeiting mechanisms, "angle-based color change" and "scattering-based revealing," to form a combined pattern, thereby improving the anti-counterfeiting effect. The second pigment 12 can be hidden within the first pigment 11, and does not display scattered color when viewed directly, making it difficult to detect. However, it can display scattered color under oblique illumination from a strong light source, making it easier for users to verify authenticity. The second pigment 12 has an extended effect of showing / hiding, making it extremely difficult to counterfeit.

[0065] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0066] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of this application and are not intended to limit the scope of protection of this application. All equivalent embodiments or modifications made without departing from the spirit of the art of this application should be included within the scope of protection of this application.

Claims

1. A color-changing pigment composition, characterized in that, The color-changing pigment composition includes a first pigment and a second pigment. The first pigment includes at least one angle-dependent optically variable pigment; The second pigment includes at least one structural color pigment capable of producing scattered colors; The first pigment and the second pigment are configured such that, under ambient light, when the viewing angle is parallel to the normal direction of the main surface of the color-changing pigment composition, the first pigment and the second pigment exhibit the same color; when the viewing angle deviates from the normal direction of the main surface of the color-changing pigment composition, the first pigment and the second pigment exhibit the same color or different color; under oblique illumination of a strong light source, the second pigment exhibits a scattered color, while the first pigment does not have the scattered color.

2. The color-changing pigment composition according to claim 1, characterized in that, The film structure of the angle-dependent color-changing optical pigment is a Fabry-Perot interferometer cavity structure.

3. The color-changing pigment composition according to claim 1, characterized in that, The second pigment includes at least one of the angle-dependent color-changing optical pigments and at least one of the structural color pigments capable of generating scattering colors. The film structure of the structural color pigment capable of generating scattering colors includes a Fabry-Perot interferometer structure and a plurality of metal nanoparticles disposed on the outer surface of the Fabry-Perot interferometer structure.

4. The color-changing pigment composition according to claim 3, characterized in that, The materials of the metal nanoparticles include at least one or an alloy of at least two of the following: silver, gold, copper, platinum, ruthenium, palladium, rhodium, cobalt, iron, nickel, and lead.

5. The color-changing pigment composition according to any one of claims 1-4, characterized in that, Under ambient light, when the viewing angle is parallel to the normal direction of the main surface of the color-changing pigment composition, the color difference between the first pigment and the second pigment is no greater than 4, wherein the colors of the first pigment and the second pigment are the overall colors calculated according to the Lab color space.

6. The color-changing pigment composition according to claim 3, characterized in that, In the structural color pigment, the mass percentage of the structural color pigment that can produce scattering color is not less than 50%.

7. The color-changing pigment composition according to claim 1, characterized in that, In dim ambient light, the color-changing pigment composition is tilted and irradiated with the strong light source so that the second pigment exhibits the scattered color, wherein the illuminance value of the dim ambient light is less than or equal to 2000 lx.

8. The color-changing pigment composition according to claim 1 or 7, characterized in that, The strong light source is strong white light, and the illuminance value of the strong light source is greater than or equal to 3000 lx.

9. The color-changing pigment composition according to claim 1, characterized in that, The angle of incidence of the high-intensity light source is 30°-85°.

10. The color-changing pigment composition according to claim 1, characterized in that, The first pigment and the second pigment are overprinted, wherein the second pigment is overprinted on the first pigment.

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