Optical variable film and preparation method thereof

Abstract

The invention discloses an optical variable film and a preparation method thereof. The optical variable film comprises a substrate layer, an adjusting layer, a photochromic layer, a protective layer, a first color layer and a second color layer which are sequentially arranged in a stacked mode, the substrate layer comprises interference lines, and the thickness of the first color layer and the thickness of the second color layer are both larger than the thickness of the interference lines. The photochromic film provided by the invention can generate a macroscopic photochromic effect indoors and outdoors, has good reflectivity and adhesive force, and is not easy to fall off.

Description

Technical Field

[0001] The present application relates to the field of film coating, and in particular to a light-variable film and a preparation method thereof. Background Art

[0002] Existing color-changing coating products generally use photosensitive color-changing materials to directly add to the product surface to form an effect layer, which has problems such as poor durability, easy to fall off, limited use environment, and short product life. Summary of the invention

[0003] In view of this, the present application provides a light-variable film and a preparation method thereof that can solve the above-mentioned technical problems.

[0004] In a first aspect, the present application provides a photochromic film, comprising a base layer, an adjustment layer, a photochromic layer, a protective layer, a first color layer and a second color layer stacked in sequence, wherein the base layer comprises interference fringes, and the thickness of the first color layer and the thickness of the second color layer are both greater than the thickness of the interference fringes.

[0005] In some embodiments, the thickness of the interference fringes is 8 nm to 27 nm.

[0006] In some embodiments, the photochromic layer includes strontium aluminate, the thickness of the photochromic layer is 10 nm to 42 nm, the refractive index of the photochromic layer is 1.50 to 3.80, and the light absorption rate of the photochromic layer is 1.35 to 5.43.

[0007] In some embodiments, the thickness of the first color layer is 36 nm to 47 nm, the refractive index of the first color layer is 1.80 to 2.40, and the light absorption rate is 5.5×10 -4 ~47.3×10 -4 The thickness of the second color layer is 14 nm to 22 nm, the refractive index of the second color layer is 1.30 to 1.60, and the light absorption rate is 1×10 -5 ~12×10 -5 .

[0008] In some embodiments, the regulating layer includes hydrogenated silicon, and the protective layer includes at least one of silicon or titanium.

[0009] In some embodiments, the optically variable film further includes a third color layer and a fourth color layer, wherein the third color layer covers the surface of the second color layer away from the first color layer, and the fourth color layer covers the surface of the third color layer away from the second color layer, the thickness of the third color layer is 30nm~42nm, the refractive index of the third color layer is 1.80~2.40, and the light absorption rate is 5.5×10 -4 ~47.3×10-4 The thickness of the fourth color layer is 10 nm to 16 nm, the refractive index of the fourth color layer is 1.30 to 1.60, and the light absorption rate is 1×10 -5 ~12×10 -5 .

[0010] In some embodiments, the thickness of the third color layer and the thickness of the fourth color layer are both greater than the thickness of the interference fringes.

[0011] A second aspect of the present application provides a method for preparing a light-variable film, comprising the following steps: Providing a substrate, and forming interference patterns on the surface of the substrate to obtain a substrate layer; An adjustment layer, a photochromic layer, a protective layer, a first color layer and a second color layer are sequentially deposited on the surface of the base layer to obtain the photovariable film, wherein the interference fringes are located between the base and the adjustment layer, and the thickness of the first color layer and the thickness of the second color layer are both greater than the thickness of the interference fringes.

[0012] In some embodiments, the step of "forming interference lines on the surface of the substrate" includes: placing the substrate in an inductively coupled plasma device, introducing an inert gas at a rate of 150 sscm to 300 sscm, controlling the DC sputtering power of the silicon target in the inductively coupled plasma device to be 9 kW to 11 kW, etching the surface of the substrate to form interference lines, and the time for forming the interference lines is 5 s to 15 s.

[0013] In some embodiments, the step of “sequentially depositing an adjustment layer, a photochromic layer, a protective layer, a first color layer, and a second color layer on the surface of the base layer” comprises: Introducing hydrogen and inert gas into the inductively coupled plasma device at a rate of 50 sscm-85 sscm and 150 sscm-300 sscm, respectively, controlling the DC sputtering power of the silicon target to be 9 kW-11 kW, depositing the adjustment layer on the surface of the substrate layer, forming the adjustment layer for 25 s-35 s, and the interference fringe is located between the substrate and the adjustment layer; Inert gas is introduced at a rate of 150 sscm to 300 sscm, the DC sputtering power of the target is controlled to be 3 kW to 5 kW, and the photochromic layer is deposited on the surface of the adjustment layer away from the interference pattern, and the time for forming the photochromic layer is 8s to 15s; Inert gas is introduced at a rate of 150 sscm to 300 sscm, the DC sputtering power of the silicon target is controlled to be 10 kW to 12 kW, and the protective layer is deposited on the surface of the photochromic layer away from the regulating layer, and the time for forming the protective layer is 5 s to 15 s; Inert gas and nitrogen are introduced at a rate of 150 sscm-300 sscm and 180 sscm-300 sscm respectively, the DC sputtering power of the silicon target is controlled to be 9 kW-13 kW, and the first color layer is deposited on the surface of the protective layer away from the photochromic layer, and the time for forming the first color layer is 40 s-45 s; Inert gas and oxygen are introduced at rates of 150sscm-300sscm and 300sscm-400sscm respectively, the DC sputtering power of the silicon target is controlled to be 9 kW-13kW, and the second color layer is deposited on the surface of the first color layer away from the protective layer. The time for forming the second color layer is 12s-20s.

[0014] The light-variable film provided by the present application includes a base layer, an adjustment layer, a photochromic layer, a protective layer, a first color layer and a second color layer which are stacked in sequence, the base layer includes interference fringes, and the thickness of the first color layer and the thickness of the second color layer are both greater than the thickness of the interference fringes. The thickness of the first color layer and the thickness of the second color layer are controlled to be greater than the thickness of the interference fringes, and the interference fringes show ups and downs, and the light waves are interfered by the interference fringes to form colorful glare. The adjustment layer can adjust the brightness and darkness of the colorful glare, and then pass through the photochromic layer to make the light-variable film produce photochromism indoors and outdoors; at the same time, the existence of interference fringes allows the material of the adjustment layer to enter the gap of the base layer, so that there is a highly absorbent substance in the base layer, which acts as an adhesive, can improve the bonding force between the photochromic layer and the adjustment layer, so that the photochromic layer is not easy to fall off, improve the durability of the light-variable film, and extend its service life; at the same time, the protective layer can convert part of the light waves into microcurrents, stimulate the photochromic layer material to react, make it react more fully, and have better effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic cross-sectional view of a light-variable film provided in accordance with an embodiment of the present application.

[0016] Figure 2 A schematic diagram of a process for preparing a light-variable film according to an embodiment of the present application.

[0017] Figure 3 This is a real picture of the light-variable film provided in one embodiment of the present application before changing color indoors.

[0018] Figure 4This is a real picture of the light-variable film provided in one embodiment of the present application after changing color outdoors.

[0019] Main component symbols The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0020] The embodiments of the present application are described in detail below. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application. The reagents and materials described in the following embodiments can all be obtained from commercial sources.

[0021] See also Figure 1 The present application provides a photochromic film, comprising a base layer 1, an adjustment layer 2, a photochromic layer 3, a protective layer 4, a first color layer 5 and a second color layer 6 which are stacked in sequence, wherein the base layer 1 comprises interference fringes 11, and the thickness of the first color layer 5 and the thickness of the second color layer 6 are both greater than the thickness of the interference fringes 11.

[0022] Interference fringes 11 are formed on the surface of the base layer 1. The interference fringes 11 can form interference fringes under the irradiation of sunlight. The interference fringes produce colorful glare under the effect of reflection. However, the sharp angle of this colorful glare is too strong and needs to be smoothed. The adjustment layer 2 is needed to adjust the brightness value of the colorful glare to reduce the sharp angle of the colorful glare and increase its smoothing angle. The photochromic layer 3 is the key to the photochromic film to achieve indoor and outdoor color change. Its principle is to benefit the luminous properties of the fluorescent material. The fluorescent material can absorb visible light or ultraviolet light and provide a stronger light source outdoors, forming a stronger interference phenomenon with the interference fringes 11 of the base layer 1. Therefore, the photochromic film can have a brighter and more vivid colorful glare when it is outdoors. The protective layer 4 protects the photochromic layer 3, and can absorb light in a specific band and convert it into microcurrent, which excites the material of the photochromic layer 3 to undergo photochromism, further enhancing the photochromic effect. Controlling the thickness of the first color layer 5 and the thickness of the second color layer 6 to be greater than the thickness of the interference fringe 11 is conducive to the naked eye observing the color change of the optically variable film indoors and outdoors.

[0023] In some embodiments, the base layer 1 may be made of stainless steel, glass, metal, or the like.

[0024] In some embodiments, the interference pattern 11 is a moth-eye structure. The moth-eye structure has depressions and protrusions, and the surface is undulating, which can produce interference phenomenon under the irradiation of sunlight.

[0025] In some embodiments, the thickness of the interference fringe 11 is 8 nm to 27 nm. For example, the thickness of the interference fringe 11 can be 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 27 nm, or any value within the range formed by any two of the above values. The thickness of the interference fringe 11 within the above range is conducive to the light-variable film to produce a gradient color glare.

[0026] In some embodiments, the adjustment layer 2 includes silicon hydride, which can help the adjustment layer 2 better adjust the brightness of the seven-color glare. The adjustment layer 2 can be deposited on the surface of the interference pattern 11 away from the base layer 1 by sputtering or evaporation. Since the moth-eye structure has depressions and protrusions, part of the material of the adjustment layer 2 can enter the depressions on the surface of the moth-eye structure, acting as an adhesive, thereby enhancing the adhesion of the photochromic layer 3.

[0027] In some embodiments, the thickness of the adjustment layer 2 is 20 nm to 40 nm, the refractive index of the adjustment layer 2 is 3.80 to 4.80, and the light absorption rate of the adjustment layer 2 is 0.0003 to 0.897.

[0028] For example, the thickness of the adjustment layer 2 can be 20nm, 25nm, 30nm, 35nm, 40nm or any value within the range formed by any two of the above values; the refractive index of the adjustment layer 2 can be 3.80, 4.00, 4.20, 4.40, 4.60, 4.80 or any value within the range formed by any two of the above values; the light absorption rate of the adjustment layer 2 can be 0.0003, 0.100, 0.200, 0.300, 0.400, 0.600, 0.700, 0.800, 0.897 or any value within the range formed by any two of the above values. The thickness of the adjustment layer 2 within the above range is conducive to better adjusting the light and dark values ​​of the seven-color dazzling light, and at the same time, it can enhance the bonding degree between the photochromic layer 3 and the adjustment layer 2.

[0029] In some embodiments, the photochromic layer 3 includes strontium aluminate, the thickness of the photochromic layer 3 is 10 nm to 42 nm, the refractive index of the photochromic layer 3 is 1.50 to 3.80, and the light absorption rate of the photochromic layer 3 is 1.35 to 5.43.

[0030] For example, the thickness of the photochromic layer 3 is 10 nm, 20 nm, 30 nm, 40 nm, 42 nm or any value within the range formed by any two of the above values; the refractive index of the photochromic layer 3 can be 1.50, 1.80, 2.00, 2.30, 2.50, 2.80, 3.00, 3.30, 3.50, 3.80 or any value within the range formed by any two of the above values; the light absorption rate of the photochromic layer 3 can be 1.35, 1.50, 2.00, 2.50, 3.00, 3.50, 4.00, 4.50, 5.00, 5.43 or any value within the range formed by any two of the above values. The thickness of the photochromic layer 3 is within the above range, which is conducive to maintaining the adhesion of the film layer, ensuring the stability of the optically variable film structure, and thus ensuring the optically variable effect of the optically variable film.

[0031] In some embodiments, the protective layer 4 includes at least one of silicon or titanium. The material of the protective layer 4 is preferably silicon, because silicon has good stability and absorption characteristics, can protect the photochromic layer 3, and can also provide specific light waves to the photochromic layer 3 to enhance the photochromic effect.

[0032] In some embodiments, the thickness of the protective layer 4 is 9 nm to 16 nm, the refractive index of the protective layer 4 is 3.6 to 4.8, and the light absorption rate of the protective layer 4 is 0.95 to 4.2.

[0033] In some embodiments, the thickness of the protective layer 4 can be 9 nm, 10 nm, 12 nm, 14 nm, 16 nm or any value within the range formed by any two of the above values, the refractive index of the protective layer 4 can be 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8 or any value within the range formed by any two of the above values, and the absorbance of the protective layer 4 can be 0.95, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.2 or any value within the range formed by any two of the above values. The thickness, refractive index and absorbance of the protective layer 4 are within the above ranges, which is beneficial for it to protect the photochromic layer 3, and at the same time can provide specific light waves to the photochromic layer 3 and enhance the photochromic effect.

[0034] In some embodiments, the thickness of the first color layer 5 is 36 nm to 47 nm, the refractive index of the first color layer 5 is 1.80 to 2.40, and the light absorption rate of the first color layer 5 is 5.5×10 -4 ~47.3×10 -4 The thickness of the second color layer 6 is 14 nm to 22 nm, the refractive index of the second color layer 6 is 1.30 to 1.60, and the light absorption rate of the second color layer 6 is 1×10 -5 ~12×10 -5 .

[0035] For example, the thickness of the first color layer 5 can be 36 nm, 38 nm, 40 nm, 42 nm, 44 nm, 46 nm, 47 nm, or any value within the range formed by any two of the above values; the refractive index of the first color layer 5 can be 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, or any value within the range formed by any two of the above values; the light absorption rate of the first color layer 5 can be 5.5×10 -4 , 10×10 -4 , 15×10 -4 , 20×10 -4 , 25×10 -4 ,30×10 -4 ,35×10 -4 , 40×10 -4 45×10 -4 47.3×10 -4 The thickness of the second color layer 6 can be 14 nm, 16 nm, 18 nm, 20 nm, 22 nm or any value within the range formed by any two of the above values. The refractive index of the second color layer 6 can be 1.30, 1.40, 1.50, 1.60 or any value within the range formed by any two of the above values. The light absorption rate of the second color layer 6 can be 1×10 -5 , 3×10 -5 , 6×10 -5 ,9×10 -5 , 12×10 -5 Or any value within the range formed by any two of the above values. The thickness, refractive index and light absorption rate of the first color layer 5 and the second color layer 6 are within the above ranges, so that the optically variable film can produce colored glare indoors and outdoors. In addition, the first color layer 5 can also play a role in hardening the structural strength of the optically variable film, which helps the optically variable film resist external impact or external laser energy.

[0036] In some embodiments, the optically variable film further includes a third color layer 7 and a fourth color layer 8, the third color layer 7 covers the surface of the second color layer 6 away from the first color layer 5, the fourth color layer 8 covers the surface of the third color layer 7 away from the second color layer 6, the thickness of the third color layer 7 is 30nm~42nm, the refractive index of the third color layer 7 is 1.80~2.40, and the light absorption rate of the third color layer 7 is 5.5×10 -4 ~47.3×10 -4 , the thickness of the fourth color layer 8 is 10 nm~16 nm, the refractive index of the fourth color layer 8 is 1.30~1.60, and the light absorption rate of the fourth color layer 8 is 1×10 -5 ~12×10-5 .

[0037] For example, the thickness of the third color layer 7 can be 30 nm, 32 nm, 34 nm, 36 nm, 38 nm, 40 nm, 42 nm, or any value within the range formed by any two of the above values; the refractive index of the third color layer 7 can be 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, or any value within the range formed by any two of the above values; the light absorption rate of the third color layer 7 is 5.5×10 -4 , 10.0×10 -4 , 15.0×10 -4 , 20.0×10 -4 , 25.0×10 -4 , 30.0×10 -4 ,35.0×10 -4 40.0×10 -4 45.0×10 -4 47.3×10 -4 or any value within the range formed by any two of the above values; the thickness of the fourth color layer 8 can be 10 nm, 12 nm, 14 nm, 16 nm or any value within the range formed by any two of the above values; the refractive index of the fourth color layer 8 can be 1.30, 1.40, 1.50, 1.60 or any value within the range formed by any two of the above values; the absorbance of the fourth color layer 8 can be 1×10 -5 , 2×10 -5 , 4×10 -5 , 6×10 -5 , 8×10 -5 , 10×10 -5 , 12×10 -5 Or any value within the range formed by any two of the above values. The thickness, refractive index and light absorption rate of the third color layer 7 and the fourth color layer 8 are within the above ranges, which can make the glare color produced by the optically variable film richer and more colorful. In addition, the third color layer 7 can also play a role in hardening the structural strength of the optically variable film, which helps the optically variable film resist external impact or external laser energy.

[0038] In some embodiments, the thickness of the third color layer 7 and the thickness of the fourth color layer 8 are both greater than the thickness of the interference fringes 11 .

[0039] See also Figure 2 The present application also provides a method for preparing the above-mentioned optically variable film, comprising the following steps: Providing a substrate, forming interference fringes 11 on the surface of the substrate, and obtaining a substrate layer 1; An adjustment layer 2, a photochromic layer 3, a protective layer 4, a first color layer 5 and a second color layer 6 are sequentially deposited on the surface of the substrate layer 1 to obtain a photovariable film, wherein the interference fringe 11 is located between the substrate and the adjustment layer 2, and the thickness of the first color layer 5 and the thickness of the second color layer 6 are both greater than the thickness of the interference fringe 11.

[0040] In some embodiments, the step of "forming interference lines 11 on the surface of the substrate" includes: placing the substrate in an inductively coupled plasma device, introducing an inert gas at a rate of 150 sscm to 300 sscm, controlling the DC sputtering power of the silicon target in the inductively coupled plasma device to be 9 kW to 11 kW, etching the surface of the substrate to form interference lines 11, and the time for forming the interference lines 11 is 5 s to 15 s.

[0041] For example, the rate of introducing the inert gas can be 150 sscm, 200 sscm, 250 sscm, 300 sscm or any value within the range formed by any two of the above values; the DC sputtering power of the silicon target can be 9 kW, 9.5 kW, 10 kW, 10.5 kW, 11 kW or any value within the range formed by any two of the above values; the time for forming the interference fringes 11 can be 5 s, 8 s, 10 s, 12 s, 15 s or any value within the range formed by any two of the above values. When the gas flow rate, the DC sputtering power of the silicon target and the time are within the above ranges when forming the interference fringes 11 on the surface of the substrate, the thickness of the obtained interference fringes 11 can be between 8 nm and 27 nm.

[0042] In some embodiments, the step of “sequentially depositing the adjustment layer 2, the photochromic layer 3, the protective layer 4, the first color layer 5 and the second color layer 6 on the surface of the base layer 1” comprises: Hydrogen and inert gas are introduced into the inductively coupled plasma device at a rate of 50 sscm-85 sscm and 150 sscm-300 sscm respectively, the DC sputtering power of the silicon target is controlled to be 9 kW-11 kW, and an adjustment layer 2 is deposited on the surface of the substrate layer 1. The time for forming the adjustment layer 2 is 25 s-35 s, and the interference fringes 11 are located between the substrate and the adjustment layer 2. The material of the adjustment layer 2 is silicon hydride. The rate of introducing hydrogen can be 50 sscm, 55 sscm, 60 sscm, 65 sscm, 70 sscm, 75 sscm, 80 sscm, 85 sscm or any value within the range formed by any two of the above values, and the rate of introducing inert gas can be 150 sscm, 180 sscm, 200 sscm, 220 sscm, 250 sscm, 280 sscm, 300sscm or any value within the range formed by any two of the above values, the DC sputtering power of the silicon target can be 9 kW, 9.5kW, 10kW, 10.5kW, 11kW or any value within the range formed by any two of the above values, and the time for forming the adjustment layer 2 can be 25s, 28s, 30s, 32s, 35s or any value within the range formed by any two of the above values; when preparing the adjustment layer 2, the gas flow rate, the DC sputtering power of the silicon target and the time are within the above range, so that the thickness of the prepared adjustment layer 2 is 20nm~40nm, the refractive index of the adjustment layer 2 is 3.80~4.80, and the absorbance of the adjustment layer 2 is 0.0003~0.897.

[0043] Inert gas is introduced at a rate of 150 sscm-300 sscm, and the DC sputtering power of the target material is controlled to be 3 kW-5 kW. The target material can be a strontium aluminate target material. The photochromic layer 3 is deposited on the surface of the adjustment layer 2 away from the interference pattern 11. The time for forming the photochromic layer 3 is 8 s-15 s. The rate of introducing the inert gas can be 150 sscm, 180 sscm, 200 sscm, 220 sscm, 250 sscm, 280 sscm, 300 sscm or any value within the range formed by any two of the above values. The DC sputtering power of the target material can be 3 kW, 3.5 kW, 4 kW, 4.5 kW, 5 kW, 6 kW, 7 kW, 8 kW, 9 kW, 10 kW, 11 kW, 12 kW, 13 kW, 14 kW, 15 kW, 16 kW, 17 kW, 18 kW, 19 kW, 20 kW, 21 kW, 22 kW, 25 kW, 26 kW, 27 kW, 28 kW, 30 kW, or any value within the range formed by any two of the above values. kW, 5kW or any value within the range formed by any two of the above values, the time for forming the photochromic layer 3 can be 8s, 10s, 12s, 15s or any value within the range formed by any two of the above values; when preparing the photochromic layer 3, the gas flow rate, the DC sputtering power of the target material and the time are within the above range, so that the thickness of the prepared photochromic layer 3 is 10 nm~42nm, the refractive index of the photochromic layer 3 is 1.50~3.80, and the absorbance of the photochromic layer 3 is 1.35~5.43.

[0044] An inert gas is introduced at a rate of 150 sscm to 300 sscm, and the DC sputtering power of the silicon target is controlled to be 10 kW to 12 kW. A protective layer 4 is deposited on the surface of the photochromic layer 3 away from the adjustment layer 2, and the time for forming the protective layer 4 is 5 s to 15 s. The rate of introducing the inert gas can be 150 sscm, 180 sscm, 200 sscm, 220 sscm, 250 sscm, 280 sscm, 300 sscm, or any value within the range formed by any two of the above values. The DC sputtering power of the silicon target can be 10 kW, 10.5 kW, 11 kW, 11.5 kW, 12 kW, or any value within the range formed by any two of the above values. The time for forming the protective layer 4 can be 5 s, 8 s, 10 s, 12 s, 15 s, or any value within the range formed by any two of the above values. When preparing the protective layer 4, the gas flow rate, the DC sputtering power of the silicon target and the time are within the above range, so that the thickness of the protective layer 4 is 9nm~16nm, the refractive index of the protective layer 4 is 3.6~4.8, and the absorbance of the protective layer 4 is 0.95~4.2.

[0045] Inert gas and nitrogen are introduced at rates of 150 sscm-300 sscm and 180 sscm-300 sscm respectively, the DC sputtering power of the silicon target is controlled to be 9 kW-13 kW, and a first color layer 5 is deposited on a surface of the protective layer 4 away from the photochromic layer 3, and the time for forming the first color layer 5 is 40 s-45 s, wherein the rate of introducing the inert gas can be 150 sscm, 180 sscm, 200 sscm, 220 sscm, 250 sscm, 280 sscm, 300 sscm or any value within the range formed by any two of the above values, the rate of introducing the nitrogen can be 180 sscm, 200 sscm, 230 sscm, 250 sscm, 280 sscm, 300 sscm or any value within the range formed by any two of the above values, the DC sputtering power of the silicon target can be 9 kW, 10 kW, 15 kW, 180 sscm, 200 sscm, 220 sscm, 250 sscm, 280 sscm, 300 sscm or any value within the range formed by any two of the above values, kW, 11 kW, 12 kW, 13 kW or any value within the range formed by any two of the above values, and the time for forming the first color layer 5 can be 40s, 41s, 42s, 43s, 44s, 45s or any value within the range formed by any two of the above values. When preparing the first color layer 5, the gas flow rate, the DC sputtering power of the silicon target and the time are within the above range, so that the thickness of the first color layer 5 is 36 nm~47 nm, the refractive index of the first color layer 5 is 1.80~2.40, and the absorbance of the first color layer 5 is 5.5×10 -4 ~47.3×10 -4 .

[0046] Inert gas and oxygen are introduced at rates of 150 sscm-300 sscm and 300 sscm-400 sscm respectively, the DC sputtering power of the silicon target is controlled to be 9 kW-13 kW, and the second color layer 6 is deposited on the surface of the first color layer 5 away from the protective layer 4, and the time for forming the second color layer 6 is 12 s-20 s, wherein the rate of introducing the inert gas can be 150 sscm, 180 sscm, 200 sscm, 220 sscm, 250 sscm, 280 sscm, 300 sscm or any value within the range formed by any two of the above values, the rate of introducing the oxygen can be 300 sscm, 320 sscm, 340 sscm, 360 sscm, 380 sscm, 400 sscm or any value within the range formed by any two of the above values, and the DC sputtering power of the silicon target can be 9 kW, 10 kW, 11 kW, 12 s, 13 s, 14 sscm, 15 sscm, 16 sscm, 17 sscm, 18 sscm, 19 sscm, 20 sscm, 22 sscm, 25 sscm, 28 sscm, 30 sscm or any value within the range formed by any two of the above values, kW, 12 kW, 13 kW or any value within the range formed by any two of the above values, and the time for forming the second color layer 6 can be 12 s, 14 s, 16 s, 18 s, 20 s or any value within the range formed by any two of the above values. When preparing the second color layer 6, the gas flow rate, the DC sputtering power of the silicon target and the time are within the above range, so that the thickness of the second color layer 6 is 14 nm to 22 nm, the refractive index of the second color layer 6 is 1.30 to 1.60, and the absorbance of the second color layer 6 is 1×10 -5 ~12×10 -5 .

[0047] In some embodiments, after the step of “depositing the second color layer 6 on the surface of the first color layer 5 away from the protective layer 4”, the method further includes: Inert gas and nitrogen are introduced at rates of 150 sscm-300 sscm and 180 sscm-300 sscm respectively, the DC sputtering power of the silicon target is controlled to be 9 kW-13 kW, and a third color layer 7 is deposited on a surface of the second color layer 6 away from the first color layer 5, and the time for forming the third color layer 7 is 30 s-40 s, wherein the rate of introducing the inert gas can be 150 sscm, 180 sscm, 200 sscm, 220 sscm, 250 sscm, 280 sscm, 300 sscm or any value within the range formed by any two of the above values, the rate of introducing the nitrogen can be 180 sscm, 200 sscm, 230 sscm, 250 sscm, 280 sscm, 300 sscm or any value within the range formed by any two of the above values, the DC sputtering power of the silicon target can be 9 kW, 10 kW, 15 kW, 20 kW, 220 sscm, 250 sscm, 280 sscm, 300 sscm or any value within the range formed by any two of the above values, kW, 11 kW, 12 kW, 13 kW or any value within the range formed by any two of the above values, and the time for forming the third color layer 7 can be 30s, 32s, 34s, 36s, 38s, 40s or any value within the range formed by any two of the above values. When preparing the third color layer 7, the gas flow rate, the DC sputtering power of the silicon target and the time are within the above range, so that the thickness of the third color layer 7 is 30nm~42nm, the refractive index of the third color layer 7 is 1.80~2.40, and the absorbance of the third color layer 7 is 5.5×10 -4 ~47.3×10 -4 .

[0048] Inert gas and oxygen are introduced at rates of 150 sscm-300 sscm and 300 sscm-400 sscm respectively, the DC sputtering power of the silicon target is controlled to be 9 kW-13 kW, and a fourth color layer 8 is deposited on the surface of the third color layer 7 away from the second color layer 6, and the time for forming the fourth color layer 8 is 8s-15s, wherein the rate of introducing the inert gas can be 150 sscm, 180 sscm, 200 sscm, 220 sscm, 250 sscm, 280 sscm, 300 sscm or any value within the range formed by any two of the above values, the rate of introducing the oxygen can be 300 sscm, 320 sscm, 340 sscm, 360 sscm, 380 sscm, 400 sscm or any value within the range formed by any two of the above values, and the DC sputtering power of the silicon target can be 9 kW, 10 kW, 11 kW, 12 kW, 15 kW, 16 kW, 17 kW, 18 kW, 20 sscm, 220 sscm, 250 sscm, 280 sscm, 300 sscm or any value within the range formed by any two of the above values, kW, 12 kW, 13 kW or any value within the range formed by any two of the above values, and the time for forming the fourth color layer 8 can be 8 s, 10 s, 12 s, 15 s or any value within the range formed by any two of the above values. When preparing the fourth color layer 8, the gas flow rate, the DC sputtering power of the silicon target and the time are within the above range, so that the thickness of the fourth color layer 8 is 10 nm to 16 nm, the refractive index of the fourth color layer 8 is 1.30 to 1.60, and the absorbance of the fourth color layer 8 is 1×10 -5 ~12×10 -5 .

[0049] The present application is described in detail below through specific embodiments.

[0050] Example 1 S1: pre-start and clean the inductively coupled plasma spectrometer, and then place the 304 stainless steel substrate into the inductively coupled plasma spectrometer; S2: introducing argon gas into the inductively coupled plasma spectrometer at a rate of 220 sscm, the DC power of the silicon target is 10 kW, laser etching is performed, the laser time is 10 s, and a moth-eye structure is obtained, and the thickness of the moth-eye structure is obtained; S3: The DC power of the silicon target and the gas flow rate of argon gas remain unchanged, and H2 is introduced into the inductively coupled plasma spectrometer at a rate of 70 sscm. The time of introducing H2 is 29.46 s, and a silicon hydrogenation layer (i.e., adjustment layer 2) is formed on the surface of the moth-eye structure away from the stainless steel substrate; S4: Only argon gas is introduced into the inductively coupled plasma spectrometer, and the gas flow rate of argon gas is still 220 sscm. The DC power of the strontium aluminate target is set to 5 kW to form a strontium aluminate layer (i.e., photochromic layer 3) on the surface of the hydrogenated silicon layer away from the moth-eye structure. This process takes 12 seconds. S5: Only argon gas is introduced into the inductively coupled plasma spectrometer, the gas flow rate of argon gas is 221 sscm, and the DC power of the silicon target is 11 kW, so as to form a silicon layer on the surface of the strontium aluminate layer away from the silicon hydrogenation layer, and this process is carried out for 10 seconds; S6: introducing argon gas into the inductively coupled plasma spectrometer at a rate of 220 sscm, introducing nitrogen gas into the inductively coupled plasma spectrometer at a rate of 300 sscm, and the DC power of the silicon target is 10 kW, so as to form a silicon nitride layer (i.e., the first color layer 5) on the surface of the silicon layer away from the strontium aluminate layer, and the time for this process is 42 seconds; S7: introducing argon gas into the inductively coupled plasma spectrometer at a rate of 220 sscm, introducing oxygen gas into the inductively coupled plasma spectrometer at a rate of 350 sscm, and the DC power of the silicon target is 10 kW, so as to form a silicon dioxide layer (i.e., the second color layer 6) on the surface of the first color layer 5 away from the silicon layer, and the process is carried out for 16 seconds; S8: Stop introducing oxygen, keep the gas flow rate of argon unchanged, introduce nitrogen into the inductively coupled plasma spectrometer at a rate of 300 sscm, and the DC power of the silicon target is 10 kW, so as to form a silicon nitride layer (i.e., the third color layer 7) on the surface of the second color layer 6 away from the first color layer 5. This process takes 36 seconds; S9: Stop introducing nitrogen, keep the gas flow rate of argon unchanged, introduce oxygen into the inductively coupled plasma spectrometer at a rate of 350sscm, and the DC power of the silicon target is 10kW to form a silicon nitride layer (i.e., the fourth color layer 8) on the surface of the third color layer 7 away from the second color layer 6. This process takes 12s.

[0051] See also Figure 3 and Figure 4 , Figure 3 This is a photo of the optically variable film prepared in this embodiment before it changes color indoors. Figure 4 This is a photo of the light-variable film prepared in this embodiment after changing color outdoors. It can be seen that the light-variable film can produce a photochromic effect when outdoors, generating colorful glare with a gradient color.

[0052] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not have step S2, and the remaining steps are the same as those of Example 1.

[0053] Embodiment 2~embodiment 3 The differences between the preparation methods of Examples 2 and 3 and Example 1 are shown in Table 1, and the rest are the same as Example 1.

[0054] Table 1 The thickness, refractive index and absorbance of the interference fringes, adjustment layer, photochromic layer, protective layer, first color layer, second color layer, third color layer and fourth color layer of Examples 1 to 3 and Comparative Example 1 are shown in Tables 2 and 3.

[0055] Table 2 Table 3 <Performance Test> Reflectivity: Light with a specific diameter and a wavelength range of 400nm~700nm is incident on the photosensitive hole to be tested. The integrating sphere receiver collects all the light that penetrates the part and converts the light signal into a digital signal output using the photoelectric effect. By measuring the reflectivity of the sample, it is tested whether the optical variable film will have an adverse effect on the clarity and pixels of the camera lens. The incident light sensed by the receiver before placing the sample is I0, and the reflected light received after placing the sample is I2. The reflectivity: R%=I2 / I0 *100%. Using this method to measure, when the reflectivity is within the range of 50%±1%, it can be considered that the optical variable film will not have an adverse effect on the clarity and pixels of the camera lens.

[0056] Color difference: Use the colorimeter CM700D for color difference test, mainly based on the Lab principle of CIE color space, to measure the Lab value of the sample to be tested and the standard base plate, where L represents brightness, with white (bright) in the positive direction and black (darker) in the negative direction; A is the red-green coordinate axis, with red in the positive direction and green in the negative direction; B is the yellow-blue coordinate axis, with yellow in the positive direction and blue in the negative direction.

[0057] Boiling water grid: Place the sample to be tested in a water bath and boil it in boiling water for 7 minutes. Then use a grid knife to cut the optically variable film on the surface of the sample into grids with a length and width of 1 mm. Use 3M special inspection tape to stick to the area with the grids and pull it to observe the shedding of the optically variable film. If the edge of the cut is completely smooth and there is no film peeling, the test level is 5B; if there is a small piece of peeling at the intersection of the cut, and the actual damage in the cross-cut area does not exceed 5%, the test level is 4B; if there is film peeling at the edge and / or intersection of the cut, and its area is greater than 5% but less than 15%, the test level is 3B; if there is partial film peeling or a large piece peeling along the edge of the cut, or some squares are peeled off in whole, and the peeling area exceeds 15% but less than 35%, the test level is 2B; if there is a large piece of peeling at the edge of the cut or some squares are partially or completely peeled off, and its area is 35% to 65% of the cross-cut area, the test level is 1B; the peeling situation is more serious than 1B, and it is 0B. If the boiling water hundred-grid test level reaches 4B or 5B, it can be considered that the optically variable film has good adhesion.

[0058] The test results of Examples 1 to 3 and Comparative Example 1 are shown in Table 4.

[0059] Table 4 Note: In Table 4, boiling water hundred grid test level ≧4B means that the boiling water hundred grid test level of this embodiment is 4B or 5B.

[0060] It can be seen from Tables 1 to 4 that, compared with Comparative Example 1, the reflectivity of the optically variable films obtained in Examples 1 to 3 is maintained within the range of 50%±1%, which will not adversely affect the clarity and pixels of the camera lens, and can produce bright and colorful glare. In addition, Examples 1 to 3 have color changes when observed at angles of 0 degrees, 40 degrees, and 90 degrees, which means that as the observation angle changes, the color of the colorful glare produced by the optically variable film will also change to a certain extent. However, the reflectivity of the optically variable film of Comparative Example 1 exceeds the range of 50%±1%, which will adversely affect the clarity and pixels of the camera lens. And Comparative Example 1 does not have color changes when observed at angles of 0 degrees, 40 degrees, and 90 degrees.

[0061] The above implementation modes are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application is described in detail with reference to the above implementation modes, a person skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A light-variable film, characterized in that: It includes a base layer, an adjustment layer, a photochromic layer, a protective layer, a first color layer and a second color layer which are stacked in sequence, wherein the base layer includes interference fringes, and the thickness of the first color layer and the thickness of the second color layer are both greater than the thickness of the interference fringes.

2. The optically variable film according to claim 1, wherein: The thickness of the interference fringes is 8 nm to 27 nm.

3. The optically variable film according to claim 1, wherein: The photochromic layer comprises strontium aluminate, the thickness of the photochromic layer is 10 nm to 42 nm, the refractive index of the photochromic layer is 1.50 to 3.80, and the light absorption rate of the photochromic layer is 1.35 to 5.

43.

4. The optically variable film according to claim 1, wherein: The thickness of the first color layer is 36 nm to 47 nm, the refractive index of the first color layer is 1.80 to 2.40, and the light absorption rate is 5.5×10 -4 ~47.3×10 -4 The thickness of the second color layer is 14 nm to 22 nm, the refractive index of the second color layer is 1.30 to 1.60, and the light absorption rate is 1×10 -5 ~12×10 -5 .

5. The optically variable film according to claim 1, characterized in that: The adjustment layer includes hydrogenated silicon, and the protection layer includes at least one of silicon or titanium.

6. The optically variable film according to claim 1, wherein: The optically variable film further comprises a third color layer and a fourth color layer, wherein the third color layer covers the surface of the second color layer away from the first color layer, and the fourth color layer covers the surface of the third color layer away from the second color layer, the thickness of the third color layer is 30nm-42nm, the refractive index of the third color layer is 1.80-2.40, and the light absorption rate is 5.5×10 -4 ~47.3×10 -4 The thickness of the fourth color layer is 10 nm to 16 nm, the refractive index of the fourth color layer is 1.30 to 1.60, and the light absorption rate is 1×10 -5 ~12×10 -5 .

7. The optically variable film according to claim 6, characterized in that: The thickness of the third color layer and the thickness of the fourth color layer are both greater than the thickness of the interference fringes.

8. A method for preparing a light-variable film according to any one of claims 1 to 7, characterized in that: The following steps are involved: Providing a substrate, and forming interference patterns on the surface of the substrate to obtain a substrate layer; An adjustment layer, a photochromic layer, a protective layer, a first color layer and a second color layer are sequentially deposited on the surface of the base layer to obtain the photovariable film, wherein the interference fringes are located between the base and the adjustment layer, and the thickness of the first color layer and the thickness of the second color layer are both greater than the thickness of the interference fringes.

9. The method for preparing the optically variable film according to claim 8, characterized in that: The step of "forming interference lines on the surface of the substrate" includes: placing the substrate in an inductively coupled plasma device, introducing an inert gas at a rate of 150sscm~300sscm, controlling the DC sputtering power of the silicon target in the inductively coupled plasma device to be 9 kW~11kW, etching the surface of the substrate to form interference lines, and the time for forming the interference lines is 5s~15s.

10. The method for preparing the optically variable film according to claim 9, characterized in that: The step of "sequentially depositing an adjustment layer, a photochromic layer, a protective layer, a first color layer and a second color layer on the surface of the base layer" comprises: Introducing hydrogen and inert gas into the inductively coupled plasma device at a rate of 50 sscm-85 sscm and 150 sscm-300 sscm, respectively, controlling the DC sputtering power of the silicon target to be 9 kW-11 kW, depositing the adjustment layer on the surface of the substrate layer, forming the adjustment layer for 25 s-35 s, and the interference fringe is located between the substrate and the adjustment layer; Inert gas is introduced at a rate of 150 sscm to 300 sscm, the DC sputtering power of the target is controlled to be 3 kW to 5 kW, and the photochromic layer is deposited on the surface of the adjustment layer away from the interference pattern, and the time for forming the photochromic layer is 8s to 15s; Inert gas is introduced at a rate of 150 sscm to 300 sscm, the DC sputtering power of the silicon target is controlled to be 10 kW to 12 kW, and the protective layer is deposited on the surface of the photochromic layer away from the adjustment layer, and the time for forming the protective layer is 5 s to 15 s; Inert gas and nitrogen are introduced at a rate of 150 sscm-300 sscm and 180 sscm-300 sscm respectively, the DC sputtering power of the silicon target is controlled to be 9 kW-13 kW, and the first color layer is deposited on the surface of the protective layer away from the photochromic layer, and the time for forming the first color layer is 40 s-45 s; Inert gas and oxygen are introduced at rates of 150sscm-300sscm and 300sscm-400sscm respectively, the DC sputtering power of the silicon target is controlled to be 9 kW-13kW, and the second color layer is deposited on the surface of the first color layer away from the protective layer. The time for forming the second color layer is 12s-20s.

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