CN221613054U

CN221613054U - All-dielectric metallic bright silver structural color film

Info

Publication number: CN221613054U
Application number: CN202322924937.5U
Authority: CN
Inventors: 卜轶坤; 李延凯; 储著伟; 王梦东; 李祎
Original assignee: Xiamen Shandie Technology Co ltd
Current assignee: Xiamen Shandie Technology Co ltd
Priority date: 2023-10-31
Filing date: 2023-10-31
Publication date: 2024-08-27
Anticipated expiration: 2033-10-31

Abstract

The utility model discloses an all-dielectric metallic bright silver structural color film. The structural color film comprises an all-dielectric interference film, wherein the all-dielectric interference film comprises a red reflecting film stack, a green reflecting film stack and a blue reflecting film stack which are stacked in a preset sequence; each film stack is alternately stacked with a plurality of high refractive index dielectric films and a plurality of low refractive index dielectric films, and the hue, saturation and brightness of the film stack are controlled by the stacking period and the center wavelength of each film stack. The utility model realizes the silver-white metallic color effect of the visible light wave band based on the additive color mixing principle of the three primary colors of red, green and blue, and realizes the metallic bright silver of the visible light broadband high reflectivity by constructing three-wave band reflection band superposition by taking the wavelengths of the three primary colors of red, green and blue as the central wavelengths of the reflection bands. By selecting different three primary color wavelengths, different basic structures and unit periods, the reflectivity adjustment and bandwidth adjustment of different red, green and blue wave bands can be realized, and metallic color effects such as metallic warm silver, neutral silver, cold silver and the like can be realized.

Description

All-dielectric metallic bright silver structural color film

Technical Field

The utility model relates to the technical field of structural color films, in particular to an all-medium metal bright silver structural color film.

Background

Structural color is a color effect caused by the structure and geometry of an object. The color is not caused by chemical components or pigments, but is caused by phenomena such as interference, diffraction, or scattering of light. Structural colors often appear in nature, such as wings of butterflies, scales, pearls, oil films, and the like. The structural color is generated due to interference phenomenon generated according to structural features of the object when light is reflected or refracted at the surface of the object. When light encounters the surface of an object, multiple reflections and refractions occur, which light is superimposed to form new light, producing a specific color effect. Common structural colors are indigo, violet, green, metallic luster, and the like. These colors are vivid, varied and appear different colors as the viewing angle changes. Structural colors are not only widely available in nature, but are also used in manufactured products such as high gloss paints, color coatings, optical films, and the like.

The structural color has a plurality of advantages: firstly, the color is bright and rich, the structural color can present bright and rich colors, and often the color is a few conspicuous colors, so that the eyeballs of people are attracted; secondly, the visual effect is unique, and the structural color is generated due to the structural characteristics of the object, so that the color effect is unique and special, and is different from the traditional chemical dye or pigment; thirdly, the angle dependence, the color effect of the structural color can change along with the change of the observation angle, so that a dynamic feeling is brought to people, and the ornamental interest is increased; fourthly, the method is pollution-free and environment-friendly, the structural color does not depend on chemical dyes or pigments, but interference phenomenon is caused by the structure of the object, so that the method does not produce environmental pollution and harmful substances; fifth, durability is good, and since the structural color is not dependent on the dye or pigment, but is caused by the structural characteristics of the object itself, the color effect is more durable than the dye or pigment to some extent. In general, structural colors have wide application in the fields of biology, chemistry, material science, etc., and are not only common in nature, but also applied to artificial products, so that the uniqueness and visual effect of the structural colors provide a plurality of unique advantages.

The prior art for realizing metallic bright silver based on a film mode is as follows: as described in patent CN1138216C, a film structure scheme of a shiny metal sheet is described, and adopts a three-layer material structure, in which a metal aluminum layer is in the middle, the thickness is 100nm, two insulating layers of magnesium fluoride or silicon dioxide are symmetrically distributed on two sides, the thickness is about 100nm, and the introduction of the insulating layers improves the rigidity and brittle fracture of the metal aluminum, so as to be suitable for the applicability of breaking the film into pigment fragments. The metal brightness is mainly realized by ensuring that the high reflectivity of the whole wave band is realized by the visible light wave band, and the high reflectivity is realized by adopting metal such as metal aluminum, silver, gold and the like with the wide wave band. The structural color material is built by adopting a full-medium film, mainly aiming at red, green, blue, yellow, purple and other color colors, and is built by adopting a conventional full-medium reflective film structure (aHbL) ⁿ aH as introduced in patent CN100475915C, different levels of reflection peaks in a visible light wave band are built by combining different high-low refractive index film materials, and the structural color film with high saturation, high brightness and large color shift under large angle change is realized.

Disclosure of utility model

In view of the above, the utility model aims to provide an all-dielectric metallic bright silver structural color film, which can be used for realizing silver effect by constructing red, green and blue basic reflection film stacks by adopting all-dielectric film materials, and combining and collocating the central reflection band positions of the red, green and blue reflection film stacks and the film stack reflectivity to complete addition red, green and blue color matching.

According to one aspect of the present utility model, there is provided an all-dielectric metallic bright silver structural color film comprising an all-dielectric interference film comprising a red reflective film stack, a green reflective film stack, and a blue reflective film stack stacked in a predetermined order;

each film stack is alternately stacked by a plurality of high refractive index dielectric films and a plurality of low refractive index dielectric films, and the saturation, brightness and tone of the film stack are controlled by the refractive index ratio of the high refractive index material to the low refractive index material, the stacking period and the center wavelength of each film stack.

In the technical scheme, the film structure color structure for realizing metallic bright silver based on the all-dielectric multilayer film is provided, the silver-white metallic color effect of a visible light wave band is realized according to the additive color mixing principle based on three primary colors of red, green and blue, the three-wave band reflection band superposition is constructed by taking the three primary color wavelengths of red, green and blue as the central wavelength of the reflection band, the metallic bright silver effect of the visible light wave band high reflectivity is realized, meanwhile, the reflectivity adjustment and bandwidth adjustment of different wave bands of red, green and blue can be realized by selecting different three primary color wavelengths and different fundamental structures and unit periods, and the metallic color effects of metallic warm silver, neutral silver, cold silver and the like can be realized. According to the three elements of color, brightness, tone and saturation correspond to the total medium reflection film stack, the design center wavelength lambda _R、λ_G、λ_B determines the main tone position of the three primary colors of red, green and blue, the bandwidth of the main reflection band of the reflection film stack determines the saturation of the three primary colors of red, green and blue, and the reflectivity of the reflection film stack determines the brightness of the three primary colors of red, green and blue. The basic relationship between the brightness, the tone and the saturation of the three elements of the color and the multi-layer dielectric film is that the reflection bandwidth of the dielectric film stack determines the saturation, the reflection bandwidth is determined by the ratio of the high refractive index to the low refractive index which is overlapped, and the wider the bandwidth is, the lower the saturation is; the larger the dielectric film stack period is, the higher the reflectivity is, and the higher the brightness is; the center wavelength determines the wavelength position of the reflection band and thus the corresponding color, i.e. hue, of the reflection band. For constructing metallic silver effect, the additive color mixing principle is adopted to perform color mixing of red, green and blue three primary colors, different center wavelengths of the three primary colors, different thickness tuning ratios and different film stack periods are selected, and the optimal combination can be performed on the brightness of the mixed color and the basic silver color tone of the mixed color respectively, so that neutral silver, warm silver, cold silver, silver yellow, gray silver and the like including silver color system color presentation with light color tone are realized.

In some embodiments, the material of the high refractive index dielectric film includes one of metal oxide, metal sulfide, metal nitride, or a mixture of at least two of the foregoing materials.

In the technical scheme, the high-refractive-index dielectric film can be selected from a fully transparent dielectric film material positioned in a visible light wave band, the refractive index range is 1.7-3, the extinction coefficient is lower than 10 ^-3, and the high-refractive-index dielectric film is fully transparent in the visible light wave band, so that the absorption of the dielectric material to light can be reduced to the greatest extent; has a higher refractive index and a higher reflectivity at a given thickness. Meanwhile, under the condition of the same optical thickness, the high refractive index material is beneficial to reducing the physical thickness of a film system, reducing the weight of the whole film and improving the optical performance; the absorption coefficient is small, the transparency is high, and the excellent optical constructive interference effect of the total dielectric reflection film can be realized; the material has high refractive index selectivity and can meet the requirements of different reflection bandwidths; the film has better mechanical property and wear resistance, and the film has good adhesive force and firmness and keeps the stability of optical performance.

In some embodiments, the low refractive index dielectric film comprises one of silicon dioxide, aluminum oxide, fluoride, or a mixture of at least two of the foregoing materials.

In the technical scheme, the low-refractive-index dielectric film can be selected from oxide and fluoride materials which are fully transparent in a visible light wave band and have refractive index ranging from 1.2 to 1.7, and the lower refractive index is favorable for combining the low-refractive-index dielectric film with the high-refractive-index dielectric material in the all-dielectric metallic bright silver structural color film to form a large refractive index ratio, so that high interference reflection is obtained under the condition of fewer film layers, a good light interference effect is realized, and bright metallic silver structural color is generated; inorganic materials such as silicon dioxide and aluminum oxide have good chemical stability, and can resist chemical substances in the environment such as humidity, temperature change and the like, so that the color stability of the all-dielectric metal bright silver structural color film in the long-term use process is ensured.

In some embodiments, the high refractive index dielectric film and the low refractive index dielectric film have a thickness of one quarter of the center wavelength of the film stack.

In the above technical scheme, based on the theory of optical interference multilayer films, the high-low refractive index all-dielectric film materials are alternately overlapped according to the optical thickness nd=λ/4 of a quarter of the central wavelength of a reflection band, so that constructive interference of the central wavelength can be realized, and the requirement of high reflectivity is met. In order to facilitate the unification of the thickness of the whole stacked film stack, reference wavelength lambda ₀ is introduced to represent all optical thicknesses, so that the value range of lambda ₀ can cover the whole visible light wave band from 380nm to 760nm, the value ranges of corresponding optical thickness coefficients a, b and c are all 0.5-2, the value range of high and low refractive indexes is considered to be 1.2-3, the optical thickness value of each film can be obtained by multiplying one fourth of the uniformly designed reference wavelength lambda ₀ by the optical thickness coefficient, the optical thickness is equal to the product of the refractive index of a material and the physical thickness, and accordingly the physical thickness value corresponding to each film can be obtained. So that the physical thickness of the corresponding high refractive index medium film of the whole film structure is in the range of 5nm-180nm, preferably 20nm-120 nm; the physical thickness of the corresponding low refractive index dielectric film is in the range of 10nm-250nm, preferably 40nm-170nm, and can well meet the full spectrum band strong interference effect of the visible light band, and the full dielectric metallic bright silver color is realized by using the wide band strong interference effect.

According to another aspect of the utility model, a method for preparing an all-dielectric metallic bright silver structural color film is provided for preparing the above-mentioned all-dielectric metallic bright silver structural color film,

The method comprises the following steps:

determining the material combination used by the all-dielectric interference film, selecting the central wavelengths of the red, green and blue reflecting film stacks, determining the stacking period of the red, green and blue reflecting film stacks according to the requirements on saturation and brightness, and determining the optical thickness coefficient of the dielectric film according to the central wavelengths of the red, green and blue reflecting film stacks;

And stacking the high-refractive-index dielectric layer material and the low-refractive-index dielectric material on a substrate according to a preset sequence through the center wavelength, the stacking period, the thickness coefficient and the material combination to obtain the all-dielectric interference film comprising a red reflecting film stack, a green reflecting film stack and a blue reflecting film stack.

In the above technical scheme, the full-medium metallic bright silver structural color film has a structure that λ_B(a₃Hb₃L)^z a₃Hc₃L a₃Hλ_G(a₂Hb₂L)^y a₂Hλ_R(a₁Hb₁L)^x c₁H, realizes the silver-white metallic color effect of visible light wave band based on the additive color mixing principle of three primary colors of red, green and blue, the central wavelength lambda _R、λ_G、λ_B of the red, green and blue reflection film stack is designed to determine the main tone position of the three primary colors of red, green and blue, the bandwidth of the main reflection band of the reflection film stack determines the saturation of the three primary colors of red, green and blue, and the reflectivity of the reflection film stack determines the brightness of the three primary colors of red, green and blue. The substrate mainly serves as a substrate for growing and bearing the structural color film, and can be a substrate for rigid processing or a flexible substrate. The basic requirement is that the surface be smooth, good finish, typically comprising a smooth stainless steel, mirror aluminum, mirror silver substrate or then a high finish glass, crystal or optical plastic selected from one of polyethylene terephthalate (PET), cellulose Triacetate (TAC), polymethyl methacrylate (PMMA), polycarbonate/polymethyl methacrylate composite (PC/PMMA), polyimide (PI), polypropylene (PP), polyvinylchloride (PVC), polyvinylbutyral (PVB), ethylene vinyl acetate copolymer (EVA), polyurethane elastomer (TPU), polytetrafluoroethylene (PTFE), fluoroethylpropene (FEP) or polyvinylidene fluoride (PVDF).

In some embodiments, the stacking period of the red, green and blue reflective film stacks is determined according to the requirements for saturation and brightness, specifically, the reflectivity of the basic medium reflective film stack is determined by the formula (1), and the reflection bandwidth is determined by the formulas (2) and (3)

Where n ₀ is the refractive index of the incident medium, n _g is the refractive index of the base material, n _L is the refractive index of the low refractive index material, n _H is the refractive index of the high refractive index material, S is the stacking period, Δg is the half width of the wave number, and λ _{In (a)} is the center wavelength of the medium reflective film stack.

In the above technical solution, formula (1) shows that when the refractive indexes of the incident medium, the high refractive index and low refractive index medium layer material, and the base material are unchanged, the reflectivity of the reflective film stack increases as the number of periods S increases. The reflection bandwidth is mainly related to the refractive index ratio of the dielectric layer, but the larger the period number is, the better the reflection band rectangle degree is, and the steeper the reflection band edge is. The number of cycles x, y, z of the red, green, and blue reflective film stacks should be determined as desired. x, y, z determine the total number of layers of the film stack, and the preparation process and film stress considered will generally range from 1 to 10, preferably from 3 to 6.

In some embodiments, the optical thickness coefficient of the dielectric film is determined according to the center wavelength of the red, green, and blue reflective film stacks, specifically: lambda ₀ is designated as a reference wavelength for the unified design of the entire red, green and blue stack sequence. The lambda/4 optical thickness coefficients a, b of the dielectric film are obtained from the formula (4)

Where lambda _R is the center wavelength of the red reflective film stack, lambda _G is the center wavelength of the green reflective film stack, and lambda _B is the center wavelength of the blue reflective film stack.

In some embodiments, the obtaining of the all-dielectric interference film further comprises:

The color effect exhibited by the film was evaluated and the film system was adjusted as needed.

In the technical scheme, the color effect of the film is evaluated, the film system is adjusted according to the requirement, part of layers can be inserted or deleted, the thickness of the part of layers is increased or reduced, fine adjustment is carried out on the center wavelength of the film stack, and the like.

In some embodiments, adjusting the film system as desired may include:

An all-dielectric metallic bright silver structural color film is deposited onto the release layer, and the multiple coatings are separated by brushing, scraping or washing by dissolving the release layer in a water bath or in a solvent.

In the above-described solution, an all-dielectric metallic bright silver structural color film is deposited onto a release layer, and the plurality of coatings are separated by brushing, scraping or washing by dissolving the release layer in a water bath (possibly at a relatively high temperature) or in a solvent (possibly at a relatively high temperature).

In some embodiments, the red, green, and blue reflective film stacks obtained by stacking high and low refractive index dielectric films at a center wavelength, stacking period, and thickness coefficient, are:

stacking dielectric films with high and low refractive indexes through a netlike film plating process to form a film membrane;

crushing the film web to obtain a film stack having an aspect ratio of at least 2:1 and an average particle size of about 5um to about 100 um;

repeating the above steps for a plurality of times to obtain a plurality of reflection film stacks.

In the above-described embodiments, the film may be formed by a web coating process in which the layers are sequentially deposited on a web material using conventional deposition techniques to form a film structure, which is then broken up and removed from the web, for example using a dissolving agent, to form a plurality of film pieces. The reducing tablet includes a plurality of film layers formed of a variety of different materials. Generally, the pigment flakes have an aspect ratio of at least 2:1 and an average particle size of from about 5um to about 1000um.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1-1 is a graph of reflectance spectra of an all-dielectric metallic bright silver structural color film of neutral silver effect as one embodiment of an all-dielectric metallic bright silver structural color film of the present utility model;

FIGS. 1-2 are structural color film chromaticity graphs of neutral silver effect of example 1 of an all-dielectric metallic bright silver structural color film of the present utility model;

FIG. 2-1 is a graph of reflectance spectra of an all-medium metallic bright silver structural color film of warm silver effect of example 2 of an all-medium metallic bright silver structural color film of the present utility model;

FIG. 2-2 is a structural color film chromaticity diagram of example 2 Warm silver effect of an all-dielectric metallic bright silver structural color film of the present utility model;

FIG. 3-1 is a graph of reflectance spectra of an all-dielectric metallic bright silver structural color film of example 3 cold silver effect of an all-dielectric metallic bright silver structural color film of the present utility model;

FIG. 3-2 is a structural color film chromaticity diagram of example 3 cold silvery effect of an all-dielectric metallic bright silvery structural color film of the present utility model;

FIG. 4-1 is a graph of reflectance spectra of an all-dielectric metallic bright silver structural color film of example 4 silver sand effect of an all-dielectric metallic bright silver structural color film of the present utility model;

FIG. 4-2 is a structural color film chromaticity diagram of example 4 silver sand color effect of an all-dielectric metallic bright silver structural color film of the present utility model;

FIG. 5-1 is a graph of reflectance spectra of an all-dielectric metallic bright silver structural color film of the gray silver effect of example 5 of an all-dielectric metallic bright silver structural color film of the present utility model;

FIG. 5-2 is a structural color film chromaticity diagram of the gray silver effect of example 5 of an all-dielectric metallic bright silver structural color film of the present utility model;

FIG. 6-1 is a graph of reflectance spectra of an all-dielectric metallic bright silver structural color film of example 6 silver yellow effect of an all-dielectric metallic bright silver structural color film of the present utility model;

FIG. 6-2 is a structural color film chromaticity diagram of example 6 silver yellow effect of an all-dielectric metallic bright silver structural color film of the present utility model;

FIG. 7 is a schematic illustration of a specific structure of an all-dielectric metallic bright silver structural color film according to the present utility model.

Detailed Description

The utility model is described in further detail below with reference to the drawings and examples. It is specifically noted that the following examples are only for illustrating the present utility model, but do not limit the scope of the present utility model. Likewise, the following examples are only some, but not all, of the examples of the present utility model, and all other examples, which a person of ordinary skill in the art would obtain without making any inventive effort, are within the scope of the present utility model.

The utility model provides an all-dielectric metal bright silver structural color film, which can be used for constructing red, green and blue basic reflection film stacks by adopting all-dielectric film materials in a basic design framework, and combining and collocating to complete additive red, green and blue color matching by adjusting the central reflection band positions of the red, green and blue reflection film stacks and the film stack reflectivity, so as to realize the silver effect.

The red base stack was defined as lambda _R(a₁Hb₁L)^x c₁ H; the green base stack was defined as lambda _G(a₂Hb₂L)^yc₂ H; the blue base stack was defined as lambda _B(a₃Hb₃L)^z c₃ H. Wherein lambda _R、λ_G、λ_B represents the center wavelength of the designed red, green and blue total-medium reflection film stacks respectively; capital letter H represents a high refractive index dielectric film, and capital letter L represents a low refractive index dielectric film; lowercase letters a, b, c are lambda/4 optical thickness coefficients of the dielectric film, and subscripts 1, 2, 3 thereof represent wavelengths centered on lambda _R、λ_G、λ_B, respectively; the letters x, y, z represent the number of cycles that the sequence repeats for the same thickness. The optical thickness value of each film can be obtained by multiplying one fourth of the uniformly designed reference wavelength lambda ₀ by an optical thickness coefficient, and the optical thickness is equal to the product of the refractive index of the material and the physical thickness, so that the corresponding physical thickness value of each film can be obtained.

The red, green, blue base stacks may also be expressed (including but not limited to the following forms): red lambda _R(a₁Hb₁ L) ≡x, green lambda _G(a₂Hb₂ L) ≡y, blue lambda _B(a₃Hb₃ L) ≡z; red lambda _R(b₁La₁ H)/(x, green lambda _G(b₂La₂ H)/(y, blue lambda _B(b₃La₃ H)/(z); red lambda _R(b₁La₁H)^x c₁ L, green lambda _G(b₂La₂H)^yc₂ L, blue lambda _B(b₃La₃H)^z c₃ L.

According to the three elements of color, brightness, tone and saturation correspond to the total medium reflection film stack, the design center wavelength lambda _R、λ_G、λ_B determines the main tone position of the three primary colors of red, green and blue, the bandwidth of the main reflection band of the reflection film stack determines the saturation of the three primary colors of red, green and blue, and the reflectivity of the reflection film stack determines the brightness of the three primary colors of red, green and blue. For constructing metallic silver effect, the additive color mixing principle is adopted to perform color mixing of red, green and blue three primary colors, different three primary color center wavelengths are selected, different high and low refractive index material combinations, different thickness tuning ratios and different film stack periods are selected, and the optimal combination can be performed on the brightness of the mixed color and the basic silver color tone of the mixed color respectively, so that neutral silver, warm silver, cold silver, silver yellow, gray silver and the like can be realized, and the color presentation of the silver system with light color tone and silver color is realized.

According to different color effect demands, the synthesized color mixing film system comprises the following structures:

D1:λ_B(a₃Hb₃L)^zλ_G(a₂Hb₂L)^yλ_R(a₁Hb₁L)^x

D2:λ_B(a₃Hb₃L)^z a₃Hλ_G(a₂Hb₂L)^y a₂Hλ_R(a₁Hb₁L)^x c₁H

D3:λ_B(a₃Hb₃L)^z a₃Hc₃Lλ_G(a₂Hb₂L)^y a₂Hc₂Lλ_R(a₁Hb₁L)^x a₁H

D4:λ_B(b₃La₃H)^zλ_G(b₂La₂H)^yλ_R(b₁La₁H)^x

D5:λ_B(b₃La₃H)^z b₃Lλ_G(b₂La₂H)^y b₂Lλ_R(b₁La₁H)^x b₁L

D6:λ_B(b₃La₃H)^z b₃Lc₃Hλ_G(b₂La₂H)^y b₂Lc₂Hλ_R(b₁La₁H)^x b₁L

The high refractive index dielectric film in this embodiment is made of oxide, sulfide or nitride material with refractive index ranging from 1.7-3, such as tantalum oxide (Ta ₂O₅), titanium oxide (TiO ₂), hafnium oxide (HfO ₂), Zirconium oxide (ZrO ₂), niobium oxide (Nb ₂O₅), yttrium oxide (Y ₂O₃), zinc sulfide (ZnS), silicon nitride (Si ₃N₄), Bismuth oxide (Bi ₂O₃), cerium oxide (CeO ₂), chromium oxide (Cr 2O 3), magnesium oxide (MgO), neodymium oxide (Nd ₂O₃), zinc oxide (ZnO) or a mixture of at least two of the foregoing materials; The low refractive index dielectric film is made of oxide or fluoride material with full transparency in visible light band and refractive index ranging from 1.2 to 1.7, such as silicon dioxide (Si 0 ₂), aluminum oxide (Al ₂O₃) or fluoride or mixture of at least two of the above materials, such as magnesium fluoride (MgF ₂), Aluminum fluoride (AlF ₃), cerium fluoride (CeF ₃), lanthanum chloride (LaF ₃), sodium hexafluoroaluminate (Na ₃AlF₆), Neodymium fluoride (NdF ₃), barium fluoride (BaF ₂), calcium fluoride (CaF ₂) or lithium fluoride (LiF) or a mixture of at least two of the foregoing.

The substrate is made of polished glass, polished stainless steel, polished mirror aluminum, mirror silver, and flexible plastic substrates such as polyethylene terephthalate (PET), cellulose Triacetate (TAC), polymethyl methacrylate (PMMA), polycarbonate/polymethyl methacrylate composite (PC/PMMA), polyimide (PI), polypropylene (PP), polyvinyl chloride (PVC), polyvinyl butyral (PVB), ethylene Vinyl Acetate (EVA), polyurethane elastomer (TPU), polytetrafluoroethylene (PTFE), fluoroethyl propylene (FEP), or polyvinylidene fluoride (PVDF). The substrate has a release layer material which is a readily water-soluble fluoride, chloride, or a water-soluble organic material and an organic solvent such as polyvinyl alcohol, acrylic resin, polyvinyl acetate, or chloride or fluoride.

As a method for preparing the structural color film, the structural color film of the full-medium metallic bright silver has the structure that λ_B(a₃Hb₃L)^z a₃Hc₃L a₃Hλ_G(a₂Hb₂L)^y a₂Hλ_R(a₁Hb₁L)^x c₁H, realizes the silver-white metallic color effect of visible light wave band based on the additive color mixing principle of three primary colors of red, green and blue, the central wavelength lambda _R、λ_G、λ_B of a red, green and blue reflecting film stack is designed to determine the main tone position of the three primary colors of red, green and blue, the bandwidth of the main reflecting band of the reflecting film stack determines the saturation of the three primary colors of red, green and blue, and the reflectivity of the reflecting film stack determines the brightness of the three primary colors of red, green and blue. The design steps are as follows:

S1, determining materials used by a film system, wherein the materials comprise a high-refractive-index dielectric layer material H, a low-refractive-index dielectric material L and a substrate material, and comprehensively considering the refractive index n, the extinction coefficient k, the physical properties of the materials such as hardness, stability, thermal properties and the like;

S2, selecting the central wavelength lambda _R、λ_G、λ_B of the red, green and blue reflecting film stacks, and determining the dominant hue position of the color represented by the structural color film;

S3, determining the cycle numbers x, y and z of the red, green and blue reflecting film stacks according to the requirements on the saturation and brightness, determining the reflectivity of the basic medium reflecting film stack H (LH) ≡S by the formula (1), and determining the reflection bandwidth by the formulas (2) and (3)

Where n ₀ is the refractive index of the incident medium and n _g is the refractive index of the base material. Equation (1) shows that when the refractive index of the incident medium, the high refractive index and low refractive index medium layer material, and the refractive index of the base material are unchanged, the reflectivity of the reflective film stack increases as the number of periods S increases. The reflection bandwidth is mainly related to the refractive index ratio of the medium layer with high and low refractive indexes, but the larger the period number is, the better the reflection band rectangle degree is, and the steeper the reflection band edge is. The cycle numbers x, y and z of the red, green and blue reflecting film stacks are determined according to the needs;

S4, for the central wavelength lambda _R、λ_G、λ_B of the selected red, green and blue reflecting film stacks, lambda ₀ is designated as a reference wavelength for unified design of the whole red, green and blue film stack sequence for convenience of representation. In this embodiment, the purpose of the reference wavelength is to consider that, when the simulation design is actually performed, the system defaults to only one reference wavelength, all thicknesses are converted into corresponding optical thickness values according to the wavelength, and for the film layer structure in which several different reflection film stacks are stacked and combined, from the viewpoint of convenience in description, the central wavelengths of the different reflection film stacks and the reference wavelength given by the system are generally used for scaling, and the scaling coefficients of the wavelengths are used for representing the corresponding optical thicknesses. The lambda/4 optical thickness coefficients a, b of the dielectric material layer are obtained from the formula (4)

S5, stacking the obtained red reflection film stack lambda _R(a₁Hb₁L)^x a₁ H, green reflection film stack lambda _G(a₂Hb₂L)^ya₂ H and blue reflection film stack lambda _B(a₃Hb₃L)^z a₃ H in a certain order to obtain a film system λ_B(a₃Hb₃L)^za₃Hλ_G(a₂Hb₂L)^y a₂Hλ_R(a₁Hb₁L)^x a₁H;

S6, evaluating the color effect exhibited by the film, adjusting the film system according to the requirement, inserting or deleting partial layers, increasing or reducing the thickness of partial layers, fine-tuning lambda _R、λ_G、λ_B, and the like, for example, adjusting the red reflection film stack lambda _R(a₁Hb₁L)^x a₁ H to lambda _R(a₁Hb₁L)^x c₁ H and the blue reflection film stack to lambda _B(a₃Hb₃L)^z a₃Hc₃ L, and adjusting the film system to λ_B(a₃Hb₃L)^z a₃Hc₃L a₃Hλ_G(a₂Hb₂L)^ya₂Hλ_R(a₁Hb₁L)^x c₁H(, wherein c is the lambda/4 optical thickness coefficient of the dielectric material layer. x, y, z determine the total number of layers of the film stack, and the preparation process and film stress considered will generally range from 1 to 10, preferably from 3 to 6. In this embodiment, the basis of the utility model is that the metallic silver effect is realized by overlapping the thickness of three reflective film stacks of red, green and blue, and different duty ratios of the three primary colors of the basic reflective film stacks in the overlapping can cause the presented metallic silver to present different silver color effects, for example, if the duty ratio of blue and green is more, the duty ratio of red is less, the superimposed metallic silver effect presents a cold silver effect, if the duty ratio is balanced, the superimposed metallic silver effect presents a silvery white effect, and if the duty ratio of red is more, the superimposed metallic silver presents a warm silver effect. Therefore, the preparation can be adjusted according to actual requirements after the preparation is completed.

In this embodiment, a Physical Vapor Deposition (PVD) method is used to prepare a thin film, for example, a method combining ion beam sputter deposition (IBS), magnetron sputter deposition (MS), electron beam Evaporation (EB), and electron beam evaporation ion assisted deposition (eb+iad) is used to prepare a thin film; chemical Vapor Deposition (CVD) methods and methods for liquid phase coating of pearlescent type films may also be employed.

The full-media metallic bright silver structural color film is deposited onto the release layer, and the multiple coatings are separated by brushing, scraping or washing, by dissolving the release layer in a water bath (possibly at a relatively high temperature) or in a solvent (possibly at a relatively high temperature). It may also be formed by a web-coating process in which the layers are sequentially deposited on a web material using conventional deposition techniques to form a thin film structure, which is then broken up and removed from the web, for example with a dissolving agent, to form a plurality of thin film pieces. The reducing tablet includes a plurality of film layers formed of a variety of different materials. Generally, the pigment flakes have an aspect ratio of at least 2:1 and an average particle size of from about 5um to about 100um.

One of the embodiments

The full-medium metallic bright silver structural color film capable of realizing the neutral silver effect has the structure that λ_B(a₃Hb₃L)^zλ_G(a₂Hb₂L)^yλ_R(a₁Hb₁L)^x, is used for selecting red central wavelength lambda _R = 680.1nm, green central wavelength lambda _G = 544.08nm and blue central wavelength lambda _B =453.4 nm, and lambda ₀ =453.4 nm is designated as reference wavelength for unified design of the whole red, green and blue film stack sequence, so that lambda/4 optical thickness coefficients are respectively: a ₁＝b₁＝1.5、a₂＝b₂＝1.2、a₃＝b₃ =1, and the stacking periods of the red, green and blue reflective film stacks are respectively as follows: the high refractive index dielectric material layer H adopts tantalum pentoxide (Ta ₂O₅) with the refractive index value of 2.15, the low refractive index dielectric material layer L adopts silicon dioxide (SiO ₂) with the refractive index value of 1.46, the total film layer number is 24, and the total physical thickness is 1925.2nm. The physical thickness values of the layers of the film stack sequence can be obtained from the optical thickness values and the refractive index of the material, as shown in table 1. The reflectance spectrum of this example is shown in FIG. 1-1, with a reflectance of up to 99% at 500nm, and a reflectance of greater than 95% for both wavelength bands 475.8nm-529.8nm and 592.4nm-633.5 nm. Fig. 1-2 show chromaticity graphs with chromaticity coordinates x:0.3152 and y:0.3387, which are close to the equivalent white spot, and with coordinates equivalent to the standard silver, and with brightness very high up to 97.7149 under CIE1931 standard chromaticity observer conditions.

Table 1A film thickness parameter Table (unit: nm) of examples

Layer number	Layer1	Layer2	Layer3	Layer4	Layer5	Layer6
							Thickness of (L)	116.03	79.09	116.03	79.09	116.03	79.09
Layer7	Layer8	Layer9	Layer10	Layer11	Layer12	Layer13
							116.03	79.09	92.82	63.27	92.82	63.27	92.82
Layer14	Layer15	Layer16	Layer17	Layer18	Layer19	Layer20
							63.27	92.82	63.27	77.35	52.73	77.35	52.73
Layer21	Layer22	Layer23	Layer24
							77.35	52.73	77.35	52.73

Table 2 one chromaticity specification parameter of the examples

Example 2

The full-medium metallic bright silver structural color film can realize a warm silver effect, and has the structure that λ_B(a₃Hb₃L)^z a₃Hλ_G(a₂Hb₂L)^y a₂Hλ_R(a₁Hb₁L)^x c₁H, selects red central wavelength lambda _R =675 nm, green central wavelength lambda _G =540 nm and blue central wavelength lambda _B =450 nm, and lambda ₀ =450 nm is designated as a reference wavelength for unified design of the whole red, green and blue film stack sequences, so that lambda/4 optical thickness coefficients can be obtained respectively: a ₁＝b₁＝1.5、c₁＝1.4、a₂＝b₂＝1.2、a₃＝b₃ =1, and the stacking periods of the red, green and blue reflective film stacks are respectively as follows: x=4, y=z=2, zinc sulfide (ZnS) is selected as the high refractive index dielectric material layer H, the refractive index value is 2.43, magnesium fluoride (MgF ₂) is selected as the low refractive index dielectric material layer L, the refractive index value is 1.38, the total number of layers is 17, and the total physical thickness is 1489.79nm. The physical thickness values of the layers of the stack sequence can be derived from the optical thickness values, the refractive index of the material, as shown in table 3. The reflectance spectrum of this example is shown in FIG. 2-1, with three major reflection bands at 438.1nm, 560nm and 658.1nm, respectively, with reflectivities of 95%,98% and 99.4%, respectively. A broadband high reflectance is achieved in the red band from 620nm to 740nm, with the red band increasing in duty ratio in additive color mixing in the film stack sequence, and a chromaticity graph is shown in fig. 2-2. Under the condition of CIE1931 standard chromaticity observer, chromaticity coordinates of the film stack are x:0.324 and y:0.3371, the film stack is close to an isoelectric white spot, presents warm silver color which is biased to a red long-wave band, and has very high brightness which reaches 95.7823.

Table 3 two film thickness parameter tables (units: nm) for the examples

Layer number	Layer1	Layer2	Layer3	Layer4	Layer5	Layer6
							Thickness of (L)	64.66	121.62	69.27	121.62	69.27	121.62
Layer7	Layer8	Layer9	Layer10	Layer11	Layer12	Layer13
							69.27	121.62	124.69	97.3	55.42	97.3	101.6
Layer14	Layer15	Layer16	Layer17
							81.08	46.18	81.08	46.18

Table 4 exemplary dichromatic parameters

Example 3

The full-medium metallic bright silver structural color film can realize a cold silver effect, and has the structure that λ_B(a₃Hb₃L)^z a₃Hc₃Lλ_G(a₂Hb₂L)^y a₂Hc₂Lλ_R(a₁Hb₁L)^x a₁H, selects red central wavelength lambda _R =630 nm, green central wavelength lambda _G =540 nm and blue central wavelength lambda _B =450 nm, and lambda ₀ =450 nm is designated as a reference wavelength for unified design of the whole red, green and blue film stack sequences, so that the three reflection film stack stacking periods with lambda/4 optical thickness coefficients of ：a₁＝b₁＝1.4、a₂＝b₂＝1.2、c₂＝1.3、a₃＝b₃＝1、c₂＝1.1, red, green and blue respectively are respectively: the high refractive index dielectric material layer H is silicon nitride (Si ₃N₄), the refractive index value is 2.07, the low refractive index dielectric material layer L is silicon dioxide (SiO ₂), the refractive index value is 1.46, the total layer number is 27, and the total physical thickness is 2030.42nm. The physical thickness values of the layers of the stack sequence can be derived from the optical thickness values, the refractive index of the material, as shown in table 5. The reflectance spectrum of this example is shown in FIG. 3-1, with the 90% reflectance major reflection band lying in the 450nm-610nm band, and a reflectance of up to 98.98% at 480 nm. In the stack sequence, the blue band is increased in duty in additive color mixing, and the chromaticity diagram is shown in fig. 3-2. Under the condition of CIE1931 standard chromaticity observer, the chromaticity coordinates of the film stack are x:0.3036 and y:0.3358, the film stack is close to an isoelectric white spot, and the film stack presents cold silver which is biased to a blue short wave band, and the brightness is very high and reaches 97.9882.

Table 5 three film thickness parameter tables (units: nm) for examples

Table 6 three-chromaticity specific parameters of the examples

Example 4

The full-medium metal bright silver structural color film can realize silver sand effect, and has the structure that λ_B(b₃La₃H)^zλ_G(b₂La₂H)^yλ_R(b₁La₁H)^x, selects red central wavelength lambda _R = 680.1nm, green central wavelength lambda _G = 544.08nm and blue central wavelength lambda _B =453.4 nm, and lambda ₀ =453.4 nm is designated as reference wavelength for unified design of the whole red, green and blue film stack sequences, so that lambda/4 optical thickness coefficients are respectively: a ₁＝b₁＝1.5、a₂＝b₂＝1.2、a₃＝b₃ =1, and the stacking periods of the red, green and blue reflective film stacks are respectively as follows: the high refractive index dielectric material layer H adopts zirconium oxide (ZrO ₂) with the refractive index value of 2.08, the low refractive index dielectric material layer L adopts sodium hexafluoroaluminate (Na ₃AlF₆) with the refractive index value of 1.35, the total layer number is 30, and the total physical thickness is 2561.1nm. The physical thickness values of the layers of the stack sequence can be derived from the optical thickness values, the refractive index of the material, as shown in table 7. The reflection spectrum of the embodiment is shown in fig. 4-1, the main reflection band is positioned in the full wave band of visible light of 420nm-760nm, the average reflectivity reaches 96.44%, and the reflectivity at 525nm is up to 99.7%. Fig. 4-2 shows a chromaticity diagram thereof. Under the condition of CIE1931 standard chromaticity observer, its chromaticity coordinates are x:0.3149 and y:0.333, and are close to the isokinetic white point, and their coordinates are identical to standard silver color, and their brightness is very high, and can be reached to 99.008. The chromaticity parameters correspondent to said film pile sequence are shown in Table 8, and its whole body presents silvery white effect.

Table 7 four film thickness parameter tables (units: nm) for the examples

Layer number	Layer1	Layer2	Layer3	Layer4	Layer5	Layer6
							Thickness of (L)	81.71	125.94	81.71	125.94	81.71	125.94
Layer7	Layer8	Layer9	Layer10	Layer11	Layer12	Layer13
							81.71	125.94	81.71	125.94	65.37	100.76	65.37
Layer14	Layer15	Layer16	Layer17	Layer18	Layer19	Layer20
							100.76	65.37	100.76	65.37	100.76	65.37	100.76
Layer21	Layer22	Layer23	Layer24	Layer25	Layer26	Layer27
							54.48	83.96	54.48	83.96	54.48	83.96	54.48
Layer28	Layer29	Layer30
							83.96	54.48	83.96

Table 8 four-color specific parameters of the examples

Example 5

The full-medium metallic bright silver structural color film can realize gray silver effect, and has the structure that λ_B(b₃La₃H)^z b₃Lλ_G(b₂La₂H)^y b₂Lλ_R(b₁La₁H)^x b₁L. selects red central wavelength lambda _R =675 nm, green central wavelength lambda _G =540 nm and blue central wavelength lambda _B =450 nm, and lambda ₀ =450 nm is designated as reference wavelength for unified design of the whole red, green and blue film stack sequences, so that lambda/4 optical thickness coefficients can be obtained respectively: a ₁＝b₁＝1.5、a₂＝b₂＝1.2、a₃＝b₃ =1, and the stacking periods of the red, green and blue reflective film stacks are respectively as follows: x=4, y=2, z=3, hafnium oxide (HfO ₂) is selected as the high refractive index dielectric material layer H, the refractive index value is 1.96, magnesium fluoride (MgF ₂) is selected as the low refractive index dielectric material layer L, the refractive index value is 1.38, the total number of layers is 19, and the total physical thickness is 1878.76nm. The physical thickness values of the layers of the stack sequence can be derived from the optical thickness values, the refractive index of the material, as shown in table 9. The reflectance spectrum of this example is shown in FIG. 5-1, with the main reflection bands at 425nm, 558.1nm and 720nm, respectively, with a reflectance of up to 88.77% at 425 nm. Fig. 5-2 shows a chromaticity diagram thereof. Under the condition of CIE1931 standard chromaticity observers, chromaticity coordinates of the film stack are x:0.289, y:0.3266, the film stack is close to an isoelectric white spot, and the film stack presents cold silver which is biased to a blue short wave band, has moderate brightness, and has a chromaticity parameter corresponding to 83.0712.

Table 9 five film thickness parameter tables (units: nm) for the examples

Film layer	Layer1	Layer2	Layer3	Layer4	Layer5	Layer6
							Thickness of (L)	121.62	86.11	121.62	86.11	121.62	86.11
Layer7	Layer8	Layer9	Layer10	Layer11	Layer12	Layer13
							121.62	86.11	218.92	68.89	97.3	68.89	178.38
Layer14	Layer15	Layer16	Layer17	Layer18	Layer19
							57.41	81.08	57.41	81.08	57.41	81.08

Specific parameters of five-color product of Table 10 examples

Example 6

The full-medium metal bright silver structural color film can realize a silver-yellow effect, and has the structure that λ_B(b₃La₃H)^z b₃Lc₃Hλ_G(b₂La₂H)^y b₂Lc₂Hλ_R(b₁La₁H)^x b₁L, selects red central wavelength lambda _R =705 nm, green central wavelength lambda _G =564 nm and blue central wavelength lambda _B =470 nm, and designates lambda ₀ =470 nm as reference wavelength for uniformly designing the whole red, green and blue film stack sequences, so that the three reflection film stack stacking periods with lambda/4 optical thickness coefficients of ：a₁＝b₁＝1.5、a₂＝b₂＝1.2、c₂＝1.35、a₃＝b₃＝1、c₂＝1.1, red, green and blue respectively are respectively: the high refractive index dielectric material layer H is zirconia (ZrO ₂) with a refractive index value of 2.08, the low refractive index dielectric material layer L is silica (SiO ₂) with a refractive index value of 1.46, the total number of layers is 23, and the total physical thickness is 1995.85nm. The physical thickness values of the layers of the stack sequence can be derived from the optical thickness values, the refractive index of the material, as shown in table 11. The reflectance spectrum of this example is shown in FIG. 6-1, with 80% reflectance major bands at 470nm-560nm and 620nm-700nm, respectively, and the highest reflectance occurs at 530nm green and 650nm red wavelengths, with reflectivities of 95.6% and 92.8%, respectively. Fig. 6-2 shows a chromaticity diagram thereof. Under the CIE1931 standard chromaticity observer condition, chromaticity coordinates of the film stack are x:0.3207 and y:0.36, the film stack is close to an isoelectric white spot, the film stack is biased to Huang Yinse, the brightness is higher, and chromaticity parameters corresponding to the film stack sequence are shown in Table 12.

Table 11 six film thickness parameter tables (units: nm) for the examples

Layer number	Layer1	Layer2	Layer3	Layer4	Layer5	Layer6
							Thickness of (L)	120.38	84.92	120.38	84.92	120.38	84.92
Layer7	Layer8	Layer9	Layer10	Layer11	Layer12	Layer13
							120.38	84.92	120.38	76.42	96.3	67.93	96.3
Layer14	Layer15	Layer16	Layer17	Layer18	Layer19	Layer20
							67.93	96.3	62.27	80.25	56.61	80.25	56.61
Layer21	Layer22	Layer23
							80.25	56.61	80.25

Table 12 six-color specific parameters of the examples

According to the embodiment, the application provides a film structure color structure for realizing metallic bright silver based on an all-dielectric multilayer film, the silver-white metallic color effect of a visible light wave band is realized according to the additive color mixing principle based on three primary colors of red, green and blue, the three-wave band reflection band superposition is constructed by taking the wavelengths of the three primary colors of red, green and blue as the central wavelength of the reflection band, the metallic bright silver effect of the visible light wave band high reflectivity is realized, meanwhile, the reflectivity adjustment and bandwidth adjustment of different wave bands of red, green and blue can be realized by selecting different wavelengths of the three primary colors and different periods of the unit, and the metallic color effects of metallic warm silver, neutral silver, cold silver and the like can be realized.

The foregoing description is only a partial embodiment of the present utility model, and is not intended to limit the scope of the present utility model, and all equivalent devices or equivalent processes using the descriptions and the drawings of the present utility model or directly or indirectly applied to other related technical fields are included in the scope of the present utility model.

Claims

1. The all-dielectric metallic bright silver structural color film is characterized by comprising an all-dielectric interference film, wherein the all-dielectric interference film comprises a red reflection film stack, a green reflection film stack and a blue reflection film stack which are stacked in a preset sequence;

Each film stack is formed by alternately stacking a plurality of high-refractive-index dielectric films and a plurality of low-refractive-index dielectric films, and the saturation, brightness and tone of the film stack are respectively controlled through the refractive index ratio of the high-refractive-index material to the low-refractive-index material, the stacking period and the central wavelength of each film stack.

2. An all-dielectric metallic bright silver structural color film as defined in claim 1,

The thickness of the high refractive index dielectric film and the low refractive index dielectric film is one quarter of the center wavelength of the film stack.