阅读说明：本技术 一种红色光学变色薄片及其制备办法 (Red optical color-changing sheet and preparation method thereof ) 是由 张秋月 郑康培 于 2019-11-20 设计创作，主要内容包括：本发明公开了一种红色光学变色薄片,所述薄片具有中心反射层,由中心反射层向外依次对称或非对称设有第一介质层、第一金属分光层、第二介质层的基本结构,通过选用合适的材料和膜层厚度,制备对称结构或不对称结构,构筑对红色波段相长的膜系结构,构造接近CIE1931体系中的过饱和的红,实现了在红色区间相长的条件,并且将红色波段主峰往视效率高效区前移,缩小了红色区间的半波宽,保证了色纯度和变色性能,实现正视颜色显示位于CIE1931体系中的红色色品区域,达到优化视效果,同时达到降低膜厚,提高材料利用率,降低能耗的目的。(The invention discloses a red optical color-changing sheet which is provided with a central reflecting layer, wherein a basic structure of a first medium layer, a first metal light splitting layer and a second medium layer is symmetrically or asymmetrically arranged from the central reflecting layer to the outside in sequence, a symmetrical structure or an asymmetrical structure is prepared by selecting proper materials and film layer thicknesses, a film system structure with a long red wave band is constructed, supersaturated red close to a CIE1931 system is constructed, the condition that the red interval is long is realized, the main peak of the red wave band is moved forward to a high-efficiency region of visual efficiency, the half-wave width of the red interval is reduced, the color purity and the color-changing performance are ensured, the red chromaticity region in the CIE1931 system is displayed by front-looking colors, the visual effect is optimized, and the purposes of reducing the film thickness, improving the material utilization rate and reducing the energy consumption are achieved.)

1. The red optical color-changing sheet is characterized by comprising a central reflecting layer, wherein a basic structure of a first dielectric layer, a first metal light-splitting layer and a second dielectric layer is symmetrically or asymmetrically arranged from the central reflecting layer to the outside in sequence, and the central reflecting layer is made of more than one of Al, Cr, Ti, Ni, Fe, Cu, Ag, Au, Sn, Mn, Co, Zr, Mo, W and Sm; the first dielectric layer is made of MgF₂、AlF₃、Na₃AlF₆、BaF₂、NdF₃、CaF₃、LiF、SiO₂、SiO、Al₂O₃、TiO_X、LiTiO_x、Ta₂O₅、ZrO₂、Nb₂O₅、HfO₂、Sb₂O₃、Fe₂O₃、CuO、NiO、Sm₂O₃、Nd₂O₃Wherein X is in the range of 1-2; the first metal light splitting layer is made of Al, Cr, Ti, Ni,Fe. More than one of Cu, Ag, Au, Sn, Mn, Co, Zr, Mo, W, Sm and the like, and the material of the second dielectric layer is SiO₂、SiO、Al₂O₃、TiO_X、LiTiO_x、Ta₂O₅、ZrO₂、Nb₂O₅、HfO₂、Sb₂O₃、Fe₂O₃、CuO、NiO、Sm₂O₃、Nd₂O₃Wherein, the value range of X is 1-2, the thickness of the central reflecting layer is 30-150nm, the thickness of the first dielectric layer is 100-250nm, the thickness of the first metal light splitting layer is 1-38nm, and the thickness of the second dielectric layer is 10-150 nm.

2. The red photochromic flake of claim 1, wherein the second dielectric layer has a thickness of from 15 to 90 nm.

3. The red optically variable sheet according to claim 1 or 2, wherein the central reflective layer is a composite central reflective layer or a magnetic core central reflective layer having a multilayer structure or an alloy structure of Al, Cr, Ti, Ni, Fe, Cu, Ag, Au, Sn, Mn, Co, Zr, Mo, W, Sm.

4. The red optically variable sheet according to claim 1 or 2, wherein a second metal-light-splitting layer is provided on the outside of the second dielectric layer, the second metal-light-splitting layer has a thickness of 0 to 7nm, and the material of the second metal-light-splitting layer is one of Al, Cr, Ti, Ni, Fe, Au, Sn, Mn, Co, Zr, Mo, W, Sm.

5. The red photochromic flake according to claim 1 or 2, wherein a third dielectric layer is arranged outside the second metal light-splitting layer, the thickness of the third dielectric layer is 0-250nm, and the material of the third dielectric layer is SiO₂、SiO、Al₂O₃、TiO_X、LiTiO_x、Ta₂O₅、ZrO₂、Nb₂O₅、HfO₂、Sb₂O₃、Fe₂O₃、CuO、NiO、Sm₂O₃、Nd₂O₃Wherein X is in the range of 1-2.

6. A method of making a red photochromic flake according to claim 4 comprising the steps of:

1) sequentially plating/coating an isolation film layer on a glass or stainless steel or flexible plastic substrate;

2) sequentially plating a second metal light splitting layer, a second medium layer, a first metal light splitting layer, a first medium layer, a central reflecting layer, a first medium layer, a first metal light splitting layer, a second medium layer and a second metal light splitting layer; the materials of the first half period and the second half period of the film layer can be the same or different;

3) circulating the step 1) and the step 2) for a plurality of times;

4) demoulding, cleaning, crushing, surface modifying and other post-treatments to obtain the required red light variable slice;

or, directly and sequentially plating a central reflecting layer, a first dielectric layer, a first metal light splitting layer, a second dielectric layer and a second metal light splitting layer on the substrate.

7. The method of claim 6, wherein the coating is performed by physical vapor deposition/chemical vapor deposition.

The technical field is as follows:

the invention relates to the technical field of optical anti-counterfeiting and the technical field of high-grade color printing and coating, in particular to a red optical color-changing sheet and a preparation method thereof.

Background art:

the optical color-changing pigment (OVP) prepared based on the principle of film multi-beam interference is a high-end anti-counterfeiting material in the anti-counterfeiting field, the displayed color of the optical color-changing pigment has the characteristic of changing along with the change of an observation visual angle, the color-changing characteristic can not be reproduced by common color copying and electronic scanning, the anti-counterfeiting performance is extremely strong, and the optical color-changing pigment can be identified by human eyes, so the optical color-changing pigment is widely applied to currency, valuable securities and the like, tobacco and wine and high-end coating markets, particularly the application in daily commodities, and the optical color-changing pigment has a good color display effect besides the optical color-changing anti-counterfeiting function. In particular, red or wine-red is particularly preferred by women.

The invention content is as follows:

the invention aims to provide a red optical color-changing sheet and a preparation method thereof, which select proper materials and film thickness, adjust the proportion of interference light and the interference level number, form a new light interference curve, wherein the curve is close to a supersaturated red spectrum curve in a CIE1931 system: the condition of interference phase length is met in a red interval, the main peak of a red waveband is moved forward to a high-efficiency visual efficiency area, and a narrow half-wave width design is adopted, so that the half-wave width of the red interval is reduced, the color purity and the color change performance are ensured, the reflectivity of a purple waveband is properly kept, and the color saturation is increased; the front view color display is realized in a Red or wine Red chromaticity area (Red, purple Red or Red purple) in a CIE1931 system, the optimization view effect is achieved, the color display effect of the Red chromaticity area is expanded, the film thickness is reduced, the thickness of each period is greatly reduced to about 0.6 mu m, the reduction amplitude is about 40%, the material utilization rate is improved, the energy consumption is reduced, and the problem that the waste of raw materials and energy consumption is caused by the fact that the film thickness is greatly increased and the layer number is weakened to weaken the display effect is avoided.

CIE XYZ is the CIE color System (CIEColor System) developed by the international commission on illumination in 1931 and revised in 1964, which is the basis for other color systems. The three colors corresponding to red, green and blue are used as three primary colors, and according to the principle of the three primary colors, the colors are actually physical quantities, and people can calculate and measure the physical quantities. Based on mathematical models of vision and the results of color matching experiments, the international commission on lighting has specified a specification called "1931 CIE standard observer", which is actually a set of color matching functions represented by three curves, and is therefore also referred to as "CIE 1931 standard matching functions" in many documents. In the color matching experiment, the observer's viewing angle was specified to be 2 degrees, and therefore, it is also referred to as a tribasic color stimulus value (tristimulus values) curve of a standard observer. The red color of fig. 2 is defined as oversaturated red, and thus it is advantageous to design to allow some reflectivity in the violet band to increase the saturation of the red color. But if the reflection of this band is too strong, it becomes purplish red, and becomes another color. Thus, in the present invention, a supersaturated red spectral curve is defined as one that is highly reflective in the red band, has a certain reflectance in violet, and is low reflective in other bands, the visible color being red or wine-red.

The invention is realized by the following technical scheme:

the red optical color-changing sheet is provided with a central reflecting layer, and a basic structure of a first dielectric layer, a first metal light splitting layer and a second dielectric layer is symmetrically or asymmetrically arranged from the central reflecting layer to the outside in sequence, wherein the central reflecting layer is made of more than one of Al, Cr, Ti, Ni, Fe, Cu, Ag, Au, Sn, Mn, Co, Zr, Mo, W and Sm, particularly, the central reflecting layer is a composite central reflecting layer and a magnetic core central reflecting layer which are of a multilayer structure or an alloy structure and are composed of the materials, such as an Al/Ni-Fe/Al magnetic core reflecting layer, and the first dielectric layer is made of MgF₂、AlF₃、Na₃AlF₆、BaF₂、NdF₃、CaF₃、LiF、SiO₂、SiO、Al₂O₃、TiO_X、LiTiO_x、Ta₂O₅、ZrO₂、Nb₂O₅、HfO₂、Sb₂O₃、Fe₂O₃、CuO、NiO、Sm₂O₃、Nd₂O₃Wherein, X is in the range of 1-2, the preferable refractive index is less than 1.6, the material of the first metal light splitting layer is more than one of Al, Cr, Ti, Ni, Fe, Cu, Ag, Au, Sn, Mn, Co, Zr, Mo, W, Sm, etc., and the material of the second dielectric layer is more than one of SiO, Cr, Ti, Ni, Fe, Cu, Ag, Au, Sn, Mn, Co, Zr, Mo, W, Sm, etc₂、SiO、Al₂O₃、TiO_X、LiTiO_x、Ta₂O₅、ZrO₂、Nb₂O₅、HfO₂、Sb₂O₃、Fe₂O₃、CuO、NiO、Sm₂O₃、Nd₂O₃Wherein, X is in the range of 1-2, the thickness of the central reflecting layer is between 30-150nm, the thickness of the first dielectric layer is 100-240nm, and the thickness of the first metal light splitting layer is as follows: 1-38nm, and the thickness of the second dielectric layer is 10-150nm, preferably 15-90 nm.

In particular, a second metal light splitting layer is arranged outside the second dielectric layer, and the thickness of the second metal light splitting layer is as follows: 0-7nm, and the second metal light splitting layer is made of one of Al, Cr, Ti, Ni, Fe, Au, Sn, Mn, Co, Zr, Mo, W, Sm and the like.

Particularly, a third dielectric layer is arranged outside the second metal light splitting layer, the thickness of the third dielectric layer is 0-250nm, and the material of the third dielectric layer is SiO₂、SiO、Al₂O₃、TiO_X、LiTiO_x、Ta₂O₅、ZrO₂、Nb₂O₅、HfO₂、Sb₂O₃、Fe₂O₃、CuO、NiO、Sm₂O₃、Nd₂O₃Wherein X is in the range of 1-2.

The invention also provides a preparation method of the red photochromic flake, which comprises the following steps:

1) sequentially plating/coating an isolation film layer on a glass or stainless steel or flexible plastic substrate;

2) sequentially plating a second metal light splitting layer, a second medium layer, a first metal light splitting layer, a first medium layer, a central reflecting layer, a first medium layer, a first metal light splitting layer, a second medium layer and a second metal light splitting layer; the materials of the first half period and the second half period of the film layer can be the same or different;

3) circulating the step 1) and the step 2) for a plurality of times;

4) demoulding, cleaning, crushing, surface modifying and other post-treatments to obtain the required red light variable slice.

Or, directly and sequentially plating a central reflecting layer, a first dielectric layer, a first metal light splitting layer, a second dielectric layer and a second metal light splitting layer on the substrate.

The coating method comprises Physical Vapor Deposition (PVD)/Chemical Vapor Deposition (CVD), such as laser evaporation, resistance evaporation, electron beam evaporation, sputtering deposition, etc.

According to the description of the color characteristics by the CIE-1931 standard colorimetry system, chromaticity coordinates x and y are used for representing chromaticity values of corresponding colors, and under the condition of a white light source, the chromaticity coordinates of a Red color domain are located in an irregular color block (Red, Purplish Red) area constructed by x being 0.4-0.73 and y being 0.135-0.345.

The invention has the following beneficial effects:

1) the invention firstly proposes to prepare supersaturated red photochromic flakes, the structure of which is close to that of supersaturated red in a CIE1931 system: the reflectivity of the purple waveband is properly kept, and the color saturation is increased; the peak re-peaking in 0-3 quarter wave thickness (QWOT) was found to be a more optimal choice at about 2 QWOT main peaks, although a five layer design is now used (first metal splitting layer M1: Ti-19nm first dielectric layer D1: MgF)₂170nm central reflecting layer MR Cu 100nm first dielectric layer D1 MgF₂170nm first metal splitting layer M1: Ti-19nm) is unimodal but half-waveThe width is very wide, see fig. 4, showing yellow, and therefore the design needs to be optimized by increasing the number of layers. This makes it possible to obtain: 1. the thickness is thin; 2. certain reflectivity is reserved in the blue-violet wave band; 3. the red wave band is a single reflection peak, the half wave width is narrow, and the color change performance is equivalent.

2) The invention uses the principle of light interference, prepares a symmetrical structure or an asymmetrical structure by selecting proper materials and film layer thickness, adjusts the proportion and the interference level of interference light, re-seeks peaks to form a new light interference curve, constructs a film system structure with long red wavelength band, and constructs supersaturated red which is close to that in a CIE1931 system: the reflectivity of a purple waveband is properly kept, the Red waveband of a high-efficiency area with the maximum visual efficiency is increased, the color saturation is increased, the condition of phase lengthening in a Red area is realized, the main peak of the Red waveband is moved forward to the high-efficiency area with the visual efficiency, the half-wave width of the Red area is reduced, the color purity and the color change performance are guaranteed, the aim of displaying a Red (Red, purple Red) chromaticity area in a CIE1931 system by the orthographic color is realized, the visual effect is optimized, the thickness of each period is greatly reduced to about 0.6 mu m, the amplitude is reduced by 40%, the purposes of reducing the film thickness, improving the material utilization rate and reducing the energy consumption are achieved, the phenomenon that a short-wave reflection secondary peak usually occurs when a Red reflection peak is constructed by a traditional 5-layer symmetrical optical variable structure is overcome, and the problem that the waste of raw materials and the energy consumption is caused by the fact that the display effect is. Also solves the problems that the prior optical color changing pigment produced by vacuum coating has low efficiency and high production cost, and restricts the application field of the pigment.

In conclusion, the invention selects proper materials and film thickness, adjusts the proportion of interference light and the interference level number, forms a new light interference curve which is close to the supersaturated red spectrum curve in the CIE1931 system: the condition of interference phase length is met in a red interval, the main peak of a red waveband is moved forward to a high-efficiency visual efficiency area, and a narrow half-wave width design is adopted, so that the half-wave width of the red interval is reduced, the color purity and the color change performance are ensured, the reflectivity of a purple waveband is properly kept, and the color saturation is increased; the front view color display is realized in a Red or wine Red chromaticity region (Red, purple Red or Reddish pure) in a CIE1931 system, the optimization view effect is achieved, the color display effect of the Red chromaticity region is expanded, the film thickness is reduced, the thickness of each period is greatly reduced to about 0.6 mu m, the reduction amplitude is about 40%, the material utilization rate is improved, the energy consumption is reduced, and the problem that the waste of raw materials and energy consumption is caused by the fact that the film thickness is greatly increased and the layer number is weakened to the display effect is avoided.

Description of the drawings:

figure 1 is a graph of the visual efficiency,

FIG. 2 is a supersaturated red in the CIE system;

figure 3 is a schematic diagram of the structure of a red photochromic flake of the present invention,

the MR, the central reflecting layer, the D1, the first dielectric layer, the M1, the first metal light splitting layer, the D2, the second dielectric layer, the M2 and the second metal light splitting layer.

Fig. 4 is a light variation curve of the five-layer structure of the present design 5;

wherein the first metal light splitting layer M1 is Ti-19nm

First dielectric layer D1 MgF₂-170nm

The central reflecting layer MR is Cu-100nm

First dielectric layer D1 MgF₂-170nm

The first metal splitting layer M1: Ti-19 nm.

FIG. 5 is a vertically observed reflectance spectrum of the 7-layer structure of example 1;

FIG. 6 is a 0-60 degree chromaticity variation trace for the 7-layer structure of example 1;

FIG. 7 is a vertically observed reflectance spectrum of the 7-layer structure of comparative example 1;

FIG. 8 is a 0-60 degree chromaticity variation trace for the 7-layer structure of comparative example 1;

FIG. 9 is a vertically observed reflectance spectrum of the 7-layer structure of example 2;

fig. 10 is a 0-60 degree chromaticity variation trace for the 7-layer structure of example 2.

FIG. 11 is the vertical observation reflectance spectrum of the 9-layer structure of example 3;

FIG. 12 is a 0-60 degree chromaticity variation trace for the 9-layer structure of example 3;

FIG. 13 is a vertically observed reflectance spectrum of the 7-layer structure of example 5;

fig. 14 is a 0-60 degree chromaticity variation trace for the 7-layer structure of example 5.

FIG. 15 is a vertically observed reflectance spectrum of the 7-layer structure of comparative example 2;

fig. 16 is a 0-60 degree chromaticity variation trace of the 7-layer structure of comparative example 2.

FIG. 17 is a vertically observed reflectance spectrum of the 11-layer structure of example 6;

fig. 18 is a 0-60 degree chromaticity variation trace for the 11-layer structure of example 6.

The specific implementation mode is as follows:

the following is a further description of the invention and is not intended to be limiting.