Red pigment chips

Abstract

The application provides a red pigment sheet. The red pigment sheet comprises a central layer and at least one set of interference cavity film stacks stacked on at least one side main surface of the central layer, each set of interference cavity film stacks comprising a first dielectric layer, a first metal light adjusting layer, a second dielectric layer and a second metal light adjusting layer which are sequentially stacked in a direction away from the central layer, wherein the thickness of the second dielectric layer is an even multiple of the thickness of the first dielectric layer, and the thicknesses of the first dielectric layer and the second dielectric layer are set so that when the observation angle is the normal direction of the main surface of the central layer, the red pigment sheet has only one main peak in the 380-780 nm wave band, the position of the main peak is at 600-700 nm, and the half peak width is less than 80 nm. The red pigment sheet has high color purity, wide color change color gamut, and large production tolerance and high efficiency.

Description

Technical Field

[0001] This application relates to the field of optically variable pigment technology, and in particular to a red pigment sheet. Background Technology

[0002] Optically variable interference pigments are produced by depositing multiple layers of thin films with interference effects on a suitable substrate using vapor deposition or other methods. When the observation angle changes, the optical path difference changes, resulting in constructive interference of light of different wavelengths at different angles, thus achieving angle-dependent color variation. Optically variable interference pigments are widely used in anti-counterfeiting and decoration.

[0003] Currently, there are many institutions engaged in the research and development of optical interference pigment sheets, and the color distribution of the optical interference pigments produced is also very wide, but there are not many that can achieve pure red structural color pigment sheets.

[0004] During the long-term research and development process, the inventors of this application discovered that existing red pigment chips have problems such as low yield, insufficient color purity, and too narrow color change range. Summary of the Invention

[0005] This application provides a red pigment sheet to solve the problems of low yield, insufficient color purity, and narrow color change range of existing red pigment sheets.

[0006] To solve the above-mentioned technical problems, one technical solution adopted in this application is: to provide a red pigment sheet, which includes a central layer and at least one set of interference cavity film stacks stacked on at least one main surface of the central layer. Each set of interference cavity film stacks includes a first dielectric layer, a first metal dimming layer, a second dielectric layer and a second metal dimming layer stacked sequentially in a direction away from the central layer. The thickness of the second dielectric layer is an even multiple of the thickness of the first dielectric layer. The thicknesses of the first dielectric layer and the second dielectric layer are set such that when the observation angle is the normal direction of the main surface of the central layer, the reflection peak of the red pigment sheet has only one main peak in the 380nm-780nm band, the position of the main peak is at 600-700nm, and the half-peak width is less than 80nm.

[0007] Furthermore, at least one set of interference cavity membrane stacks is symmetrically arranged on both sides of the central layer.

[0008] Furthermore, the thickness ratio of the first dielectric layer to the second dielectric layer is 1:2.

[0009] Furthermore, at least one set of interferometric cavity membrane stacks has a resin layer covering its outer surface.

[0010] Furthermore, the refractive index of the resin layer is 1.05–1.75, and the thickness of the resin layer is 50 nm–3000 nm.

[0011] Further, the material of the center layer comprises at least one of aluminum, silver, gold, platinum and indium, or the material of the center layer comprises at least one of iron, cobalt, nickel or oxides of at least one of them, or the material of the center layer comprises an alloy of at least two of iron, cobalt, nickel, manganese and carbon.

[0012] Further, the center layer comprises a first high-reflection metal layer, a magnetic layer and a second high-reflection metal layer which are sequentially stacked.

[0013] Further, the material of the first dielectric layer and the second dielectric layer comprises at least one of silicon dioxide, magnesium fluoride, titanium dioxide, aluminum oxide, silicon monoxide and zinc sulfide.

[0014] Further, the material of the first metal light-adjusting layer and the second metal light-adjusting layer comprises at least one of chromium, nickel, titanium, copper, germanium and silicon.

[0015] Further, when the observation angle deviates from the normal direction of the main surface of the center layer, the color change of the red pigment sheet comprises cyan.

[0016] The beneficial effects of the present application are: different from the related art, the red pigment sheet provided by the present application comprises a center layer and at least one set of interference cavity film stack stacked on at least one side main surface of the center layer, each set of interference cavity film stack comprises a first dielectric layer, a first metal light-adjusting layer, a second dielectric layer and a second metal light-adjusting layer which are sequentially stacked away from the center layer. The thickness of the second dielectric layer is an even multiple of the thickness of the first dielectric layer, and the thicknesses of the first dielectric layer and the second dielectric layer are set so that when the observation angle is the normal direction of the main surface of the center layer, the red pigment sheet has only one main peak in the 380nm-780nm wave band, the position of the main peak is at 600-700nm, and the half peak width is less than 80nm. The color saturation of the red pigment sheet of the present application is high, the color change range is wide, the production tolerance is large, and the production efficiency is high. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0018] Figure 1 is a structural schematic diagram of a red pigment sheet according to an embodiment of the present application;

[0019] Figure 2 is a front view spectral reflectance diagram of the red pigment sheet in Embodiment 1;

[0020] Figure 3 is a side view 60° spectral reflectance plot of the red pigment chip in Example One;

[0021] Figure 4 is a front view spectral reflectance plot of the red pigment chip in Example Two;

[0022] Figure 5 is a side view 60° spectral reflectance plot of the red pigment chip in Example Two. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0024] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0025] In addition, if the embodiments of the present application involve descriptions such as “first”, “second”, etc., the descriptions of “first”, “second”, etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first”, “second” can explicitly or implicitly include at least one of the features. In addition, the technical solutions of the various embodiments can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is also not within the scope of protection claimed by the present application.

[0026] The present application provides a red pigment chip, please refer to Figure 1 as shown, Figure 1 is a structural schematic diagram of an embodiment of the red pigment chip provided by the present application. The red pigment chip 10 includes a central layer 11 and at least one set of interference cavity film stacks 12 stacked on at least one side main surface of the central layer 11.

[0027] Specifically, the central layer 11 includes two side main surfaces opposite to each other, at least one set of interference cavity film stacks 12 can be arranged on one side main surface of the central layer 11, or at least one set of interference cavity film stacks 12 can be arranged on both side main surfaces of the central layer 11.

[0028] Preferably, at least one set of interference cavity membrane stacks 12 are symmetrically arranged on both sides of the central layer 11. For example, in Figure 1 In the illustrated embodiment, a set of interference cavity film stacks 12 are symmetrically arranged on opposite sides of the central layer 11. In this way, both sides of the red pigment sheet 10 can exhibit the same color effect.

[0029] Furthermore, such as Figure 1 As shown, each set of interference cavity film stacks 12 includes a first dielectric layer 121, a first metal dimming layer 122, a second dielectric layer 123, and a second metal dimming layer 124, which are sequentially stacked along the direction away from the central layer 11.

[0030] The first metal dimming layer 122 and the first dielectric layer 121 form a first interference cavity, and the second metal dimming layer 124 and the second dielectric layer 123 form a second interference cavity.

[0031] In this design, the thickness of the first dielectric layer 121 in the first interference cavity is less than the thickness of the second dielectric layer 123 in the second interference cavity. Specifically, the thickness of the second dielectric layer 123 is an even multiple of the thickness of the first dielectric layer 121. For example, the thickness of the second dielectric layer 123 is 2 times, 4 times, or 6 times the thickness of the first dielectric layer 121. Since a larger thickness increases the cost of the red pigment sheet 10, the balance between performance and thickness can be measured through application methods.

[0032] Furthermore, in the red pigment sheet 10 of this application, the thickness of the first dielectric layer 121 and the second dielectric layer 123 is set such that when the observation angle is the normal direction of the main surface of the central layer 11, that is, at a 0° observation angle, there is only one main peak in the 380-780nm band, the position of the main peak is at 600-700nm, and the half-peak width is less than 80nm.

[0033] The red pigment flake 10 of this application has the characteristics of high-purity red and wide color gamut.

[0034] According to the reflection characteristics of the medium layer, the reflectivity of the single medium layer to the determined wavelength is periodic with the change of the film layer optical thickness. If the refractive index dispersion is ignored, the periodicity of the reflectivity of the single medium layer has a dual nature: it can appear periodic repetition when the film layer thickness increases; or it can appear periodic repetition of the reflectivity to different frequencies when the film layer thickness is constant. Therefore, in the prior art, to achieve the red effect, constructive interference is usually realized in the red band of about 600-700 nm, so the value between 600-700 nm is used as a reference wavelength, the thickness of the medium layer is set to an even multiple QWOT of the reference wavelength, and a plurality of equal-thickness interference cavities are combined to suppress the secondary peaks of the blue band interference. The reflection of the medium to light follows the multi-beam reflection principle, so the position of the reflection peak of the reflected light of a specific wavelength by the medium depends largely on the optical path difference, and the optical path difference Δ = 2ndcosθ, n is the refractive index, d is the thickness of the medium layer, and θ is the incident angle, so the size of the optical path difference depends on the refractive index, the thickness of the medium layer, and the incident angle. Therefore, the color change range can be adjusted by adjusting the refractive index and the thickness of the material.

[0035] By analyzing the light path, the first medium layer 121 close to the center layer 11 is the layer that determines the color hue base tone. If it is set to be too thick, it will shorten the period of reflectivity on the wavelength, that is, it will reduce the spacing between the interference peaks, and additional interference secondary peaks will be generated in the visible light band. The second medium layer 123 away from the center layer can form an additional interference cavity, which mainly plays a filtering role, so the color change range can be widened by increasing the thickness. Based on the above principle, the selected multi-layer medium layer is based on an interference cavity group, the thickness relationship of the medium layers in the cavity group is set to an even multiple relationship, and the first medium layer 121 close to the center layer 11 is set to a thin layer, that is, the thickness of the second medium layer 123 is an even multiple of the thickness of the first medium layer 121. In this way, both constructive interference in the red region and widening of the color change range can be achieved.

[0036] Alternatively, as shown in Figure 1 the outer surface of at least one set of interference cavity film stacks 12 is coated with a resin layer 13. Specifically, the inventors of the present application found in continuous experiments that when the center layer 11 and the interference cavity film stack 12 are prepared by plating and form a precursor, and then are crushed, the outermost layer of the precursor is coated with a resin layer 13, which can effectively narrow the spectral half-width, further improve the brightness and purity of the color, and the resin layer 13 can serve as a protective layer to improve the weather resistance of the pigment.

[0037] The red pigment flake 10 of this application has enhanced sensitivity to the medium layer, and can still ensure the good quality of the hue of the red pigment flake 10 within a certain error range; in terms of hue, in the red area of ​​the 1931 CIEXYZ color space, it is manifested as an oversaturated red, with a wide range of color change, and the side color can reach the cyan-green area. It has obvious color change and high weather resistance.

[0038] Optionally, the refractive index of the resin layer 13 is in the range of 1.05–1.75, for example, the refractive index of the resin layer 13 is 1.2, 1.5, or 1.7. The physical thickness of the resin layer 13 is in the range of 50 nm–3000 nm, for example, the physical thickness of the resin layer 13 can be 50 nm, 70 nm, 100 nm, 1000 nm, 2000 nm, or 3000 nm.

[0039] Optionally, the material of the central layer 11 may include a highly reflective metal, primarily including at least one of aluminum, silver, gold, platinum, and indium.

[0040] Optionally, the material of the central layer 11 may also include a magnetic material. Specifically, the material of the central layer 11 may include oxides of at least one of iron, cobalt, and nickel. Alternatively, the material of the central layer 11 may include an alloy of at least two of iron, cobalt, nickel, manganese, and carbon.

[0041] Optionally, the central layer 11 may include a first highly reflective metal layer, a magnetic layer, and a second highly reflective metal layer stacked sequentially. That is, the central layer 11 may be composed of two layers of highly reflective metal material sandwiching a layer of magnetic material.

[0042] Optionally, the materials of the first dielectric layer 121 and the second dielectric layer 123 include at least one of silicon dioxide, magnesium fluoride, titanium dioxide, aluminum oxide, silicon monoxide, and zinc sulfide.

[0043] Optionally, the materials of the first metal dimming layer 122 and the second metal dimming layer 124 include at least one of chromium, nickel, titanium, copper, germanium and silicon.

[0044] In summary, in the interference cavity film stack 12 of the red pigment sheet 10 provided in this application, the thickness relationship between the second dielectric layer 123 and the first dielectric layer 121 is set to an even multiple, which can achieve constructive interference in the red region and broaden the color change range. Furthermore, coating the outermost layer of the precursor with a resin layer 13 effectively narrows the half-width of the spectrum, further improving the brightness and purity of the color, and the resin layer 13 can also serve as a protective layer, improving the weather resistance of the red pigment sheet 10. Two specific embodiments of the red pigment sheet are described below.

[0045] Example 1

[0046] In this embodiment, the red pigment sheet comprises a 9-layer structure precursor, the structure of which can be seen from Figure 1 As shown, the precursor is coated with a resin layer after being crushed. The precursor is: / Cr (thickness 6 nm) / SiO2 (thickness 440 nm) / Cr (thickness 8 nm) / SiO2 (thickness 220 nm) / AL (thickness 30 nm) / SiO2 (thickness 220 nm) / Cr (thickness 8 nm) / SiO2 (thickness 440 nm) / Cr (thickness 8 nm) / . After the precursor is plated in a vacuum system, the precursor is crushed, and then the precursor is placed in resin to coat a resin layer, so as to obtain a red pigment sheet.

[0047] As shown in Figure 2 The pigment sheet of this embodiment has the characteristics of higher red saturation (reflected in narrower red half-peak width) and wide color change range. As shown in Figure 3 When the observation angle deviates from the normal direction of the main surface of the central layer by 60°, the main peak is shifted to 540 nm.

[0048] The red pigment sheet of this embodiment has higher color saturation (reflected in narrower half-peak width, the half-peak width is less than 80 nm, and the short-wave region impurity peak is suppressed to less than 10%), and the total thickness is small, which reduces the material cost and film forming time cost.

[0049] Example Two

[0050] In this embodiment, the red pigment sheet comprises a 17-layer structure precursor, and the precursor is coated with a resin layer after being crushed. The plating precursor structure is: Cr (thickness 4 nm) / SiO2 (thickness 440 nm) / Cr (thickness 6 nm) / SiO2 (thickness 220 nm) / Cr (thickness 4 nm) / SiO2 (thickness 440 nm) / Cr (thickness 6 nm) / SiO2 (thickness 220 nm) / AL (thickness 30 nm) / SiO2 (thickness 220 nm) / Cr (thickness 6 nm) / SiO2 (thickness 440 nm) / Cr (thickness 4 nm) / SiO2 (thickness 220 nm) / Cr (thickness 6 nm) / SiO2 (thickness 440 nm) / Cr (thickness 4 nm) / . After the precursor is plated in a vacuum system, the precursor is crushed, and then the precursor is placed in resin to coat a resin layer, so as to obtain a red pigment sheet. The red pigment sheet of this embodiment has more saturated chroma compared with the red pigment sheet of Example One, which can be seen from Figure 4 As shown, it is reflected in narrower half-peak width, the half-peak width is less than 50 nm, the short-wave region impurity peak is suppressed to less than 10%, and it has a wider color change range in the color change range. As shown in Figure 5 Figure 5 ​is the reflectance spectrum of 60° observation angle, when the observation angle is 60°, the main peak is shifted to 530nm. The color change range is through red, orange, yellow, green, blue, and the color change range is widened.

[0051] The red pigment sheet of the embodiment has very special color change performance, and the production cost is almost doubled compared to the first embodiment. In specific applications, the performance and cost balance point can be measured by application approach.

[0052] The above is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent flow transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A red pigment chip, characterized by, The red pigment sheet comprises a central layer and at least one set of interference cavity film stacks stacked on at least one side main surface of the central layer, each set of the interference cavity film stacks comprises a first dielectric layer, a first metal light modulation layer, a second dielectric layer and a second metal light modulation layer stacked in sequence away from the central layer, Wherein, the thickness of the second dielectric layer is an even multiple of the thickness of the first dielectric layer, the thicknesses of the first dielectric layer and the second dielectric layer are set so that when the observation angle is the normal direction of the main surface of the central layer, the red pigment sheet has only one main peak in the 380-780nm wave band, the position of the main peak is at 600-700nm, and the half peak width is less than 80nm, Wherein, the outer surface of the at least one set of interference cavity film stacks is coated with a resin layer, the resin layer is used at least to narrow the spectral half-wave width, improve color display brightness and purity.

2. The red pigment chip according to claim 1, characterized in that, The central layer is symmetrically provided with the at least one set of interference cavity film stacks on both sides opposite to each other.

3. The red pigment chip according to claim 1, characterized in that, The thickness ratio of the first dielectric layer to the second dielectric layer is 1:

2.

4. The red pigment chip according to claim 1, characterized in that The refractive index of the resin layer is: 1.05-1.75, the thickness of the resin layer is: 50nm-3000nm.

5. The red pigment chip according to claim 1, wherein The material of the central layer comprises at least one of aluminum, silver, gold, platinum and indium, or, The material of the central layer comprises at least one of iron, cobalt, nickel or oxides of at least one of them, or, The material of the central layer comprises an alloy of at least two of iron, cobalt, nickel, manganese and carbon.

6. The red pigment chip according to claim 1, characterized in that The central layer comprises a first high-reflection metal layer, a magnetic layer and a second high-reflection metal layer stacked in sequence.

7. The red pigment chip according to claim 1, characterized in that, The material of the first dielectric layer and the second dielectric layer comprises at least one of silicon dioxide, magnesium fluoride, titanium dioxide, aluminum oxide, silicon monoxide and zinc sulfide.

8. The red pigment chip according to claim 1, characterized in that, The material of the first metal light modulation layer and the second metal light modulation layer comprises at least one of chromium, nickel, titanium, copper, germanium and silicon.

9. The red pigment chip according to claim 1, characterized in that, When the observation angle deviates from the normal direction of the main surface of the central layer, the discoloration of the red pigment sheet comprises cyan.

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