CN114134464A

CN114134464A - Structural color pigment and preparation method thereof

Info

Publication number: CN114134464A
Application number: CN202111248299.9A
Authority: CN
Inventors: 龙芬; 向杰; 吴伟才; 石斌
Original assignee: Huizhou Foryou Optical Technology Co ltd
Current assignee: Huizhou Foryou Optical Technology Co ltd
Priority date: 2021-10-26
Filing date: 2021-10-26
Publication date: 2022-03-04

Abstract

The application provides a structural color pigment and a preparation method thereof, wherein the preparation method comprises the following steps: preparing a first optical material by adopting a vapor deposition method under the condition that the vacuum degree is 1.0E-2 pascal or below; crushing the first optical material; and carrying out heat treatment on the crushed first optical material to obtain a second optical material. The preparation method is simple in process, product diversity can be achieved, and physical and chemical properties of the product can be improved.

Description

Structural color pigment and preparation method thereof

Technical Field

The application relates to the technical field of preparation of structured color pigments, in particular to a structured color pigment and a preparation method thereof.

Background

The optical color-changing film is an application branch in optical films and comprises two main categories of optical chemical color-changing and optical physical color-changing, wherein the optical chemical color-changing and the optical physical color-changing are respectively the color-changing generated by chemical reaction caused by the action of light, and the optical color-changing generated by physical action of light, namely structural color. Structural color, also known as physical color, refers to the color produced by light and structural interactions commensurate with the magnitude of the wavelength of the light. Such as multi-beam interference effect of the film, layered interface light reflection and refraction, so that the film has the effect of color variation with angle, that is, under natural light, the transmitted or reflected light beam changes with angle along with the change of the incident angle due to the equivalent optical path of the film stack sequence, so as to cause the shift of the reflection or transmission spectrum, thereby the film can present different color conversion. For another example, a diffraction grating uses periodically arranged wiener structures to decompose light to produce iridescent colors.

In the prior art, an evaporation method is generally adopted to prepare a structural color optical film in a vacuum environment, but if a product with low cost and diversified optical effects is obtained through vacuum coating, the difficulty is very high. In the aspect of equipment, the device relates to a vacuum chamber system, a vacuum obtaining system, a vacuum measuring system, a power supply system, a mechanical transmission system, a heating and temperature measuring system, a precise evaporation source system, a water cooling system, a precise industrial control system, a water vapor trapping system and an ion source system. In the aspect of process, the method relates to a plurality of factors such as a film thickness monitoring technology, deposition rate matching, substrate temperature matching, vacuum degree matching, evaporation angle matching and the like. Therefore, the requirements for equipment and process are extremely high for preparing products with high quality and diversified color changing effects, and even individual requirements cannot be realized only by vacuum coating.

Therefore, the product is regulated and controlled only through the vacuum coating process, the defects of complex operation and single product are overcome, and the performance of the prepared optical film is lower.

Disclosure of Invention

The application provides a structural color pigment and a preparation method thereof, which are used for solving the technical problems that in the prior art, the product regulation and control are carried out only through vacuum coating, so that the control is complex, the product is single, and the performance of the prepared optical film is lower.

In order to solve the technical problem, the application adopts a technical scheme that: provided is a method for preparing a structured color pigment, the method comprising: preparing a first optical material by adopting a vapor deposition method under the condition that the vacuum degree is 1.0E-2 pascal or below; crushing the first optical material; and carrying out heat treatment on the crushed first optical material to obtain a second optical material.

Further, the first optical material is a color-changing material or a non-color-changing material.

Furthermore, the range of the vacuum degree is 5E-1 to 1.0E-2 pascal.

Further, the second optical material is a color-changing material or a non-color-changing material.

Further, performing heat treatment on the crushed first optical material, wherein the heat treatment comprises heating the crushed first optical material to a first temperature; maintaining the comminuted first optical material at a first temperature for a first predetermined time; raising the temperature of the first optical material after being crushed from the first temperature to a second temperature; maintaining the comminuted first optical material at a second temperature for a second predetermined time; and reducing the temperature of the crushed first optical material from the second temperature to a third temperature.

Further, the heat treatment of the first optical material after pulverization includes heat treatment of the first optical material by mixing one or more of oxygen, nitrogen, argon, hydrogen, and the like.

Further, the first optical material and the second optical material are different in chemical composition and chemical structure, and the second optical material is superior in color change effect, magnetic property, thermal conductivity, electrical conductivity, corrosion resistance and oxidation resistance to the first optical material.

Further, the structure of the first optical material is a multiple metal-dielectric Fabry-Perot interference structure, or the structure of the first optical material is a full-dielectric high-low refractive index material film stack.

Further, the first optical material is a material having at least one of a magnetic property, an iridescent effect property and a photochromic property; the second optical material is a material having at least one of magnetic properties, iridescent effect properties and photochromic properties.

In order to solve the above technical problem, another technical solution adopted by the present application is: the structural color pigment is prepared by adopting the preparation method of any one of the embodiments.

The beneficial effects of the embodiment of the application are that: in contrast to the prior art, the present application provides a method for preparing a structured color pigment comprising: the first optical material is prepared by adopting a vapor deposition method under the condition that the vacuum degree is 1.0E-2 pascal or below, and in the application, the first optical material can be prepared under the environment with poor vacuum degree condition, so that the coating process is simplified; then crushing the first optical material; and then carrying out heat treatment on the crushed first optical material to further shape the first optical material so as to obtain a second optical material. The preparation method has the advantages of simple process, better manufacturing process and lower cost; moreover, by regulating and controlling the film system in the vacuum plating stage and matching a series of process conditions of heat treatment, the diversity of the product can be realized, and the physical and chemical properties of the product can be further improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic flow diagram of one embodiment of a method for preparing a structured color pigment provided herein;

FIG. 2 is a flowchart illustrating an embodiment of step S13 in FIG. 1;

FIG. 3 is an SEM image of sample No. 1 in the first embodiment of the disclosure;

FIG. 4 is an SEM image of sample No. 2 in the second embodiment;

FIG. 5 is an SEM image of a sample No. 3 in the third example provided by the present application;

FIG. 6 is an SEM image of a 4# sample of the fourth embodiment;

FIG. 7 is a schematic diagram of a theoretical simulated reflection curve of a film system according to one embodiment and another embodiment of the present disclosure;

FIG. 8 is a graph showing the actual measured reflectance curves of sample No. 1 in the first embodiment and sample No. 2 in the second embodiment;

FIG. 9 is a schematic diagram of a temperature-increasing curve of an embodiment corresponding to step S13 in FIG. 1;

FIG. 10 is a schematic diagram of a temperature-increasing curve of another embodiment corresponding to step S13 in FIG. 1;

FIG. 11 is a schematic diagram illustrating a temperature-increasing curve of another embodiment corresponding to step S13 in FIG. 1;

fig. 12 is a schematic diagram of a temperature-increasing curve of another embodiment corresponding to step S13 in fig. 1.

Detailed Description

The present application will now be described in detail with reference to specific embodiments thereof as illustrated in the accompanying drawings. These embodiments are not intended to limit the present application, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present application.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present application, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present application.

The inventor of the application discovers through a large number of experiments that in the whole process of a product, vacuum coating is combined with the treatment of the next step, specifically, a product which is not formed is prepared in the vacuum coating stage, the treatment of the next step is formed again, and the physical and chemical properties of the product, such as optical effect, magnetism and other properties, are regulated and controlled through the parameters of the vacuum coating stage and the parameters of the post-treatment stage, so that the requirements on the existing coating equipment can be reduced, the coating process is simplified, and the product diversification can be realized.

Referring to fig. 1, fig. 1 is a schematic flow chart of an embodiment of a method for preparing a structural color pigment provided in the present application, where the method includes:

s11: the first optical material is prepared by adopting a vapor deposition method under the condition that the vacuum degree is 1.0E-2 pascal or below.

First, a first optical material is prepared by a vapor deposition method. Specifically, the preparation of the first optical material may be performed using a physical vapor deposition method or a chemical vapor deposition method.

In one embodiment, the vacuum level may range from 1.0E-2 and below, and specifically, the initial vacuum level condition is set to 1.0E-2 pascal and below, and the inflation gas flow condition is set to correspond to the initial vacuum level, with the rule being to maintain the vacuum level at 1.0E-2 and below. In another embodiment, the vacuum degree can also be in the range of 5E-1 to 1.0E-2 pascal.

In the embodiment, the first optical material can be prepared in the environment with poor vacuum degree condition, the requirement on the existing coating equipment is reduced, and the coating process is simplified.

Further, in some specific embodiments, the first optical material may be a color changing material or a non-color changing material. The color-changing effect of the color-changing material can be as follows: the color changes to non-color and the metal color changes to color, the color is the color with different brightness and purity of one or more of red, orange, yellow, green, cyan, blue and purple, and the non-color is the color with different brightness, black, white and gray.

When the first optical material is a color-changing material, the structure of the first optical material may be a multiple heavy metal-dielectric fabry-perot interference structure. Further, the multiple metal-dielectric Fabry-Perot interference structure at least contains one of titanium, chromium, iron, aluminum, silver and copper or an alloy of at least two of the titanium, the chromium, the iron, the aluminum, the silver and the copper.

In other embodiments, the structure of the first optical material may also be a full-dielectric high-low refractive index material film stack. Further, the full-medium high-low refractive index material film stack at least contains one of titanium oxide, silicon oxide, magnesium fluoride and lanthanum titanate or the combination of at least two of the titanium oxide, the silicon oxide, the magnesium fluoride and the lanthanum titanate.

Further, the first optical material is a material having at least one of a magnetic property, an iridescent effect property and a photochromic property. That is, the first optical material may be a combination of magnetic, photochromic and iridescent properties. In other embodiments, the first optical material may also have any one or two of the above characteristics alone, such as the first optical material being a magnetic material or a non-magnetic material, the first optical material being an iridescent structural color pigment, or the first optical material being a photochromic pigment, etc.

In the above embodiment, when the first optical material is prepared, the preparation conditions can be set to be relatively low, so that the first optical material with relatively low performance can be obtained, thus the requirements on equipment and a preparation process can be reduced, the manufacturing process is optimized, and the production cost is saved.

S12: the first optical material is subjected to a pulverization treatment.

After the first optical material is obtained, the first optical material is subjected to crushing treatment, such as airflow crushing, hydraulic crushing or ultrasonic crushing.

In particular, the first optical material may be broken into pieces of 1-200 microns. For example, the first optical material is broken into pieces of 1 micron, 20 microns, 30 microns, 50 microns, 100 microns, 150 microns, or 200 microns.

S13: and carrying out heat treatment on the crushed first optical material to obtain a second optical material.

After the pulverized first optical material is obtained, it is further subjected to heat treatment to obtain a second optical material.

Specifically, the heat treatment mode comprises at least one of high-temperature annealing, electric heating, microwave heating, laser heating and infrared heating.

Further, the conditions of the heat treatment include combinations of various means such as reaction substance, reaction time, reaction temperature, heating means, and the like.

The reaction material for heat treatment may include one or more of oxygen, nitrogen, argon, hydrogen, etc.

In a specific embodiment, the step of heat treating the comminuted first optical material comprises:

s131: and heating the crushed first optical material to a first temperature.

In the heat treatment of the first optical material, the first optical material may be subjected to stepwise temperature rise. First, the temperature of the first optical material after pulverization is raised to a first temperature. Specifically, the first optical material may be linearly warmed to the first temperature.

S132: the comminuted first optical material is maintained at a first temperature for a first predetermined time.

After the temperature of the first optical material after being crushed is raised to the first temperature, the first optical material is kept at the first temperature for a first preset time. That is, the temperature of the crushed first optical material is constant for the first predetermined time.

S133: and raising the temperature of the crushed first optical material from the first temperature to the second temperature.

After the first preset time, the first optical material is continuously heated to be heated from the first temperature to the second temperature. Specifically, the first optical material may be linearly warmed to the second temperature.

S134: and maintaining the crushed first optical material at a second temperature for a second predetermined time.

And after the temperature of the first optical material after being crushed is raised to the second temperature, keeping the temperature of the first optical material after being crushed at the second preset temperature for a second preset time, namely keeping the temperature of the first optical material after being crushed at the second preset temperature for the second preset time.

S135: and reducing the temperature of the crushed first optical material from the second temperature to a third temperature.

In addition, the temperature rising section or the temperature falling section in the heat treatment stage can be controlled step by step and in multiple sections according to actual requirements, and only one example is illustrated here, and the other cases can be analogized.

And after the second preset time, reducing the temperature of the first optical material from the second temperature to a third temperature. Specifically, the first optical material may be linearly cooled to a third temperature.

The chemical composition and chemical structure of the first optical material are changed by performing heat treatment on the crushed first optical material. The concrete embodiment is as follows: the first optical material and the second optical material have different chemical component ratios, different crystal forms of the components, or the two optical materials occur simultaneously.

In the above embodiment, the performance of the obtained second optical material is better than that of the first optical material. Specifically, the properties include physical properties and chemical properties. The physical properties include: discoloration effect, magnetic properties, thermal conductivity, electrical conductivity, and the like; the chemical properties include: corrosion resistance, oxidation resistance, and the like.

The second optical material may be a color changing material or a non-color changing material. The color-changing effect of the color-changing material can be as follows: the color changes to non-color and the metal color changes to color, the color is the color with different brightness and purity of one or more of red, orange, yellow, green, cyan, blue and purple, and the non-color is the color with different brightness, black, white and gray.

The second optical material is a material having at least one of magnetic properties, iridescent effect properties and photochromic properties. For example, the second optical material may have a combination of magnetic properties, iridescent effects, photochromic properties, and the like.

In one embodiment, the non-color of the first optical material and the color of the second optical material can be realized by regulating and controlling the film system in the vacuum plating stage and matching a series of process conditions of later-stage heat treatment, and the production cost can be obviously reduced.

In another embodiment, the first optical material obtained in the vacuum plating stage may not show a color change effect, or only have a metallic color, or be achromatic, and the second optical material obtained after the heat treatment may have a color change effect, such as a color-to-color change, a color-to-achromatic change, and other changes.

In another embodiment, the first optical material obtained in the vacuum plating stage may be a non-magnetic material, and the second optical material obtained after the heat treatment may have magnetism, so that the non-magnetic property of the first optical material and the magnetic property of the second optical material may be achieved.

In another embodiment, the first optical material obtained in the vacuum deposition stage can be made to have a non-iridescent effect and the second optical material obtained after the heat treatment can have an iridescent effect, so that the non-iridescent effect of the first optical material and the iridescent effect of the second optical material can be achieved.

In other embodiments, the transparency can be controlled, for example, after the vacuum plating stage, the first optical material is in a non-transparent state, and after the combination of heat treatments under different conditions, the transparency of the second optical material can be changed in different gradients, even completely transparent.

The following will describe the preparation method of the structural color pigment with reference to specific examples.

Example one

(1) Preparing the first optical material by physical vapor deposition

Setting the vacuum degree to be 1.0E-2Pa, vacuumizing a vacuum system to be 1.0E-2Pa, preparing a multilayer optical membrane for 20min under the condition of no oxygenation to obtain a first optical material, wherein the structure of the multilayer optical membrane is a multiple metal-dielectric Fabry-Perot interference structure, and specifically comprises the following steps: a/titanium/silica/titanium/total 5-layer structure, the thickness of which is respectively: 10nm/320nm/40nm/320nm/10nm/, and then the membrane is broken (using air flow or hydraulic, ultrasonic, etc.) into small pieces with a particle size of about 13 microns (D50), which are defined as (1-1) # samples.

(2) "thermochemical treatment" of pigments to obtain a second optical material

Electrically heating the fine slices prepared in the step (1) in an oxygen atmosphere, processing according to a temperature rise curve 1 in fig. 9, and slowly cooling to room temperature to obtain the front surface: green, side color: pink all-dielectric photochromic pigment (second optical material), the photochromic pigment resulting from this step being defined as sample # 1.

Example two (comparative test to example one)

(1) Optical film prepared by physical vapor deposition

Setting the vacuum degree to be 5.0E-3Pa, pumping a vacuum system to be 5.0E-3Pa, and preparing the multilayer optical membrane for 60min under the condition of no oxygenation, wherein the optical membrane is of an all-medium high-low refractive index material membrane stack structure and is characterized in that: titanium dioxide/silicon dioxide/titanium dioxide, the thickness of each layer is: 10nm/320nm/40nm/320nm/10nm, and then the membrane is broken (using airflow or hydraulic breaking, ultrasonic breaking, etc.) into small chips with the particle size of about 13 microns at D50, which is sample No. 2.

EXAMPLE III

(1) Preparing the first optical material by physical vapor deposition

Setting the vacuum degree to be 1.0E-2Pa, vacuumizing a vacuum system to be 1.0E-2Pa, requiring 20min, and preparing a multilayer optical color-changing membrane under the condition of oxygenation to obtain a first optical material, wherein the structure is a full-medium high-low refractive index material membrane stack structure, and the specific structure is as follows: titanium dioxide/silicon dioxide/titanium dioxide, the thicknesses are respectively: 10nm/320nm/40nm/320nm/10nm, and then the membrane is broken (using air flow or hydraulic, ultrasonic etc.) into small pieces with a particle size of about 25 microns at D50.

(2) "thermochemical treatment" of pigments to obtain a second optical material

The fine pieces prepared in (1) are heated electrically in an N2 atmosphere, treated according to a temperature rise curve 2 in FIG. 10, and then slowly cooled to room temperature, so that the front surface can be obtained: green, side color: pink all-dielectric photochromic pigment (second optical material), the photochromic pigment obtained in this step being defined as sample # 3.

EXAMPLE four (comparative test of EXAMPLE three)

Setting the vacuum degree to 5.0E-3Pa, pumping the vacuum system to 5.0E-3, requiring 60min, and preparing a multilayer optical color-changing membrane under the condition of oxygenation, wherein the membrane structure is an all-dielectric high-low refractive index material membrane stack structure and is as follows: titanium dioxide/silicon dioxide/titanium dioxide, the thickness of each layer is: 10nm/320nm/40nm/320nm/10nm, then the film is broken (using airflow or hydraulic breaking, ultrasonic breaking, etc.) into small thin pieces with the particle size of about 25 microns at D50, and then the optically variable pigment is defined as sample No. 4.

EXAMPLE five (translucency test)

(1) Preparing the first optical material by physical vapor deposition

Setting the vacuum degree to be 1.0E-2Pa, and preparing a multilayer optical membrane under the condition of no oxygenation to obtain a first optical material, wherein the first optical material is of a multiple metal-dielectric Fabry-Perot interference structure, and the specific structure is as follows: the silicon dioxide/titanium/silicon dioxide total 7-layer structure, the thickness is: 420nm/20nm/420nm/40nm/420nm/20nm/420nm, and then the membrane is broken (using airflow or hydraulic breaking, ultrasonic breaking, etc.) into small pieces with the particle size of about 30 microns at D50.

(2) "thermochemical treatment" of pigments to obtain a second optical material

Heating the fine slices prepared in (1) in air by electricity, processing according to a temperature rise curve 3 in fig. 11, and then slowly cooling to room temperature to obtain the front surface: purple, lateral color: violet blue and light violet optical color changing pigment.

EXAMPLE six

(1) Preparing the first optical material by physical vapor deposition

Setting the vacuum degree to be 1.0E-2Pa, and preparing a multilayer optical membrane under the condition of no oxygenation to obtain a first optical material, wherein the first optical material is of a multiple metal-dielectric Fabry-Perot interference structure, and the specific structure is as follows: a/titanium/silica/aluminum/silica/titanium/total 5-layer structure with the respective thicknesses: and/7 nm/340nm/30nm/340nm/70nm, and then crushing the membrane (crushing by using airflow or hydraulic crushing, ultrasonic crushing and the like) into small fine pieces with the particle size of about 18 microns at D50.

(2) "thermochemical treatment" of pigments to obtain a second optical material

Electrically heating the fine slices prepared in the step (1) in air, uniformly heating to 300 ℃ within 60min, preserving heat for 2h at the temperature, and slowly cooling to room temperature to obtain the front surface: silver green, side color: silver yellow, bright silver in appearance.

EXAMPLE seven

(1) Preparing the first optical material by physical vapor deposition

Setting the vacuum degree to be 1.0E-3Pa, and preparing a multilayer optical film under the condition of no oxygenation to obtain a first optical material, wherein the structure of the first optical material is as follows: silica/iron/silica. The thicknesses are respectively as follows: 160nm/15nm/270nm/50nm/270nm/15nm/160 nm. The membrane is then broken (using air or hydraulic, ultrasonication, etc.) into small pieces with a particle size of 5 microns at D50.

(2) "thermochemical treatment" of pigments to obtain a second optical material

The fine pieces prepared in the step (1) are heated electrically in an oxygen-filled atmosphere, processed according to a temperature rise curve 4 in fig. 12, and then slowly cooled to room temperature, so that the front view color is green, the side view color is blue, and the maximum reflectivity is 51% when the observation angle is 60 °. The test remanence is 8T, and the coercive force is 300 Oe. When the included angle is 0 DEG, the reflectivity can reach 78%, the transmissivity is lower in the short wave band (380-550nm), and the highest transmissivity can reach 100% in the long wave band (550-780 nm). So that the first optical material obtained in the first step becomes to have the comprehensive characteristics of light variability, transparency and magnetism in the second step.

Example eight

(1) Preparing the first optical material by physical vapor deposition

Setting the vacuum degree to be 1.0E-2Pa, and preparing a multilayer optical membrane under the condition of no oxygenation to obtain a first optical material, wherein the first optical material is of a multiple metal-dielectric Fabry-Perot interference structure, and the specific structure is as follows: titanium/silicon dioxide/aluminum/silicon dioxide/titanium, 5-layer structure, thickness is: 1nm/240nm/40nm/240nm/1nm, and then the membrane is broken (using airflow breaking, hydraulic breaking, ultrasonic breaking and the like) into small fine pieces with the particle size of about 10 microns at D50.

(2) "thermochemical treatment" of the pigment to obtain a second optical material

Mixing the fine slices prepared in the step (1) with titanium salt and deionized water in a mass ratio of 10: 1: 89 mixing, slowly dripping urea while stirring, filtering, washing, and drying. The second optical material was obtained by heating in air by electric heating according to the temperature rise curve 1 in fig. 9. Thus obtaining the pigment flakes with rainbow colors.

Supplementary explanation: the outermost layer of the first optical material obtained in the step (1) is a discontinuous film and is titanium nanodots, and the surface color of the first optical material is silver yellow without a color change effect or an iridescent effect. And in the second step, after coating titanium dioxide, performing heat treatment to obtain a second optical material, wherein the surface of the second optical material is a micro-nano lattice (the size of the micro-nano lattice is larger than that of the titanium nano dots of the first optical material, the micro-nano lattice can reach the size of a visible light wave band and can generate diffraction action enough) to form a light splitting grating, and the diffraction action can generate rainbow color under natural illumination, and the effect of color variation along with angles can be realized due to the interference action of a silicon dioxide layer.

Further, the 1#, 2#, 3# and 4# optical color changing pigments obtained in example one, example two, example three and example four were tested for acid resistance and alkali resistance by national standard (GB/T5221.5-2008); testing the reflectivity and the saturation of the 1#, 2#, 3# and 4# optical color-changing pigments by a photometer; the results of the tests are shown in table 1.

The 1#, 2#, 3# and 4# optical color changing pigments obtained in example one, example two and example three were subjected to a high temperature resistance test, and the results are shown in table 1. Temperature resistance test method: taking 2.0g of sample in a crucible, raising the temperature of a muffle furnace to a test temperature, and then placing the test sample in the muffle furnace to be heated for 30 min; taking out, cooling at room temperature, and absorbing moisture for 4 h; and scraping and observing, wherein the evaluation standard is as follows: the sample scraping after the test also has better light variation effect, and the color phase is similar to that before the treatment.

Table 1 list of test results for each sample

As can be seen from Table 1, the second optical material prepared by the preparation method provided by the application has excellent reflectivity, acid resistance, alkali resistance and high temperature resistance.

Further, the Scanning Electron Microscope (SEM) images obtained by subjecting the 1#, 2#, 3#, and 4# optical color changing pigments to SEM Scanning tests show that, as shown in fig. 3 to 6, microscopically, the density of the 1# sample is significantly higher than that of the 2# sample and that of the 3# sample is higher than that of the 4# sample, which corresponds to the resistance results tested in table 1. The section of the 1# and 3# samples is more regular, which shows that the two samples are transformed in crystal form or component, and are different from the 2# and 4# samples.

Further, the sample # 1-1 and the sample # 1 of the first example were subjected to X-ray diffraction analysis, and it was found that the sample # 1 after the "heat treatment" clearly had the formation of a new substance and the product had a better crystallinity. This result corresponds to the increased resistance of the test in table 1.

In order to further understand the reflection condition of each sample, theoretical simulation is carried out on the sample structures in the first embodiment and the second embodiment, the obtained theoretical reflection curve is shown in fig. 7, through comparison of two groups of tests, the conditions set by the first embodiment are 1.0E-2 pascal, the time is 20min, the conditions set by the second embodiment are 5.0E-3 pascal, and the time is 60min, each preparation process saves at least 40min in time, meanwhile, the electric power required by a vacuum pumping system for maintaining a lower vacuum degree in the coating process is greatly reduced, the effective working time is increased in one day, and the efficiency is greatly improved. Meanwhile, the vacuum pumping system does not need a vacuum pump with multiple stages and higher specifications, and a deep cooling system is not needed, so that the coating vacuum equipment is simplified. Therefore, the cost of the plating film of the first embodiment is much lower than that of the second embodiment, and the actual reflectivity of the samples 1# and 2# is tested under the same conditions, and the result is shown in fig. 8. From the test results, the actual and theoretical trends are substantially consistent, so the curve reflectivity of the second pigment obtained by the preparation method of the application is higher. Therefore, compared with a single coating process, the color change effect of the product is better.

Further, the preparation of pigment with optically variable, transparent and magnetic characteristics is realized by the seventh embodiment, which is very difficult to realize by only vacuum coating, because it is difficult to evaporate a film layer having both magnetism and certain transparency only by the coating process. By the preparation method, the severity of the final product to the original process is reduced, and the diversity of product performance can be realized.

The effect results of SEM analysis, X-ray diffraction analysis and surface color are combined to display, and the unification of color changing effect, cost and chemical stability can be considered by combining various process conditions.

In summary, in the first vacuum coating stage, the final product effect is optimal by changing the vacuum coating conditions, such as reducing the vacuum degree to a relatively low state, controlling certain conditions in the subsequent process and compensating through a relatively simple process, thereby achieving the effects of reducing the overall cost and enhancing the effect. Moreover, the control of material proportion, crystal structure and compound type is realized more accurately by regulating and controlling different processing environments and conditions in the process from the target material to the final finished product. The preparation method can optimize the process, reduce the requirements on equipment and simultaneously realize product diversification, such as preparation of transparent pigment, magnetic pigment and transparent magnetic pigment.

In the second step of the process, various effects can be achieved by controlling the atmosphere during the thermal reaction, such as: when the all-dielectric material needs to be prepared, a semi-finished product containing a metal simple substance or a partially oxidized metal oxide can be plated in the first step, and then the high-transparency all-dielectric material can be formed after the semi-finished product is subjected to heat treatment containing oxidizing gas; similarly, a fully oxidized or partially oxidized metal oxide semi-finished product may be formed in the first step by plating, and then subjected to a heat treatment in a reducing gas to form a highly metallic material. In addition, when the heat treatment is performed, different reaction curves can be adjusted according to the characteristics of the first-step semi-finished product to achieve different effects, for example, the transparent full-quality light variation effect can be achieved by using the curve 1 in fig. 9 and the curve 2 in fig. 10; the semi-permeable effect can be achieved by curve 3 in fig. 11, and so on. The selection can be specifically performed according to actual needs, and is not limited herein.

The application also provides a structural color pigment which is prepared by adopting the preparation method of any one of the embodiments. For the preparation method of the structural color pigment, please refer to the description of any of the above embodiments, which is not repeated herein.

It should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art will be able to make the description as a whole, and the embodiments may be appropriately combined to form other embodiments as will be appreciated by those skilled in the art.

The above detailed description is given for the purpose of illustrating a practical embodiment of the present application and is not to be construed as limiting the scope of the present application, and any equivalent embodiments or modifications that do not depart from the technical spirit of the present application are intended to be included therein.

Claims

1. A method for preparing a structured color pigment, the method comprising:

preparing a first optical material by adopting a vapor deposition method under the condition that the vacuum degree is 1.0E-2 pascal or below;

crushing the first optical material;

and carrying out heat treatment on the crushed first optical material to obtain a second optical material.

2. The method of claim 1, wherein the first optical material is a color changing material or a non-color changing material.

3. The method according to claim 2, wherein the degree of vacuum is in a range of 5.0E "1 to 1.0E" 2 pascals.

4. The method of claim 1, wherein the second optical material is a color changing material or a non-color changing material.

5. The method of claim 1, wherein the heat treating the comminuted first optical material comprises,

heating the crushed first optical material to a first temperature;

maintaining the comminuted first optical material at the first temperature for a first predetermined time;

raising the temperature of the first optical material after being crushed from the first temperature to a second temperature;

maintaining the comminuted first optical material at the second temperature for a second predetermined time;

and reducing the temperature of the first optical material after being crushed from the second temperature to a third temperature.

6. The method of claim 1, wherein the heat treating the comminuted first optical material comprises,

the first optical material is subjected to heat treatment by mixing one or more of oxygen, nitrogen, argon, hydrogen, and the like.

7. The production method according to claim 1, wherein the first optical material and the second optical material are different in chemical composition and chemical structure, and the second optical material is superior in discoloration effect, magnetic property, thermal conductivity, electrical conductivity, corrosion resistance, and oxidation resistance to the first optical material.

8. The method as claimed in claim 2, wherein the first optical material is structured as a multiple metal-dielectric Fabry-Perot interference structure, or the first optical material is structured as a film stack of all-dielectric high-low refractive index materials.

9. A production method according to claim 1, wherein the first optical material is a material having at least one of a magnetic property, an iridescence effect property and a photochromic property; the second optical material is a material having at least one of magnetic properties, iridescent effect properties and photochromic properties.

10. A structural color pigment, characterized in that it is produced by the production method according to any one of claims 1 to 9.