CN109597152B

CN109597152B - Narrow-band reflective film

Info

Publication number: CN109597152B
Application number: CN201710933107.5A
Authority: CN
Inventors: 于甄; 张国臻; 夏振
Original assignee: Zhangjiagang Kangdexin Optronics Material Co Ltd
Current assignee: Zhangjiagang Kangdexin Optronics Material Co Ltd
Priority date: 2017-09-30
Filing date: 2017-09-30
Publication date: 2021-05-11
Anticipated expiration: 2037-09-30
Also published as: CN109597152A

Abstract

The invention provides a narrow-band reflective film. The method comprises the following steps: a transparent substrate layer; reflectionA film system including n units of high and low refractive index materials, the reflective film system including at least one film system having a structure of [ (. alpha. ])₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL) wherein H represents a high refractive index material layer, L represents a low refractive index material layer, n and m are positive integers, n is greater than 3 and less than or equal to 150, m is greater than 3 and less than or equal to 50, m is less than or equal to n, and alpha is in the same film stack₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The same gradient rule on the same cosine waveform or sine waveform is satisfied independently; for the ith high and low index material unit alpha_iHβ_iL，1≤i≤n,α_iDenotes the optical thickness of the ith high refractive index material layer as a multiple of lambda/4, beta_iThe optical thickness of the ith low-refractive index material layer accounts for the multiple of lambda/4, and the reflecting film system or the transparent substrate layer is also provided with a light absorbing agent.

Description

Narrow-band reflective film

Technical Field

The invention relates to the field of optical film structures, in particular to a narrow-band reflecting film.

Background

The existing reflective film is coated on the surface A of a high-molecular PET substrate, and the surface B is coated with metallic aluminum, wherein the surface A is coated with HUD fluorescent powder, a dyeing material, nanosphere resin and the like, and the bandwidth of the HUD fluorescent powder, the dyeing material and the nanosphere resin is wider, so that the color gamut of an optical device applying the reflective film is poor, the whitening is serious, and the role product effect is poor. Meanwhile, most of the reflecting films in the market are full-wave-band cut-off reflecting films which adopt metal layers for reflection, and the product is low in transmittance and basically opaque due to full-wave reflection. The individual partial wavelength cut-off reflective film has a wide reflection wavelength range, so that the transmittance loss is large, and the film is basically a translucent product with a certain color. The product prepared by the invention has high transparency, no whitening and almost no color, has very high reflectivity in a plurality of specified wavelength ranges, and can form full-color reflection patterns according to the display requirement.

Therefore, a reflective film with a narrow reflection bandwidth is needed to optimize the optical effect of the optical device.

Disclosure of Invention

The invention mainly aims to provide a narrow-band reflecting film to solve the problem that the reflecting film in the prior art is large in reflection bandwidth.

In order to achieve the above object, according to one aspect of the present invention, there is provided a narrow band reflection film comprising: a transparent substrate layer; the reflecting film system comprises n high-low refractive index material units, wherein the high-low refractive index material units are sequentially laminated on one surface or two opposite surfaces of the transparent substrate layer, each high-low refractive index material unit comprises a high-low refractive index material layer and a low-low refractive index material layer matched with the high-low refractive index material layer, and the reflecting film system comprises at least one film system with the structure of alpha (alpha)₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL) wherein H represents a high refractive index material layer, L represents a low refractive index material layer, n and m are positive integers, n is greater than 3 and less than or equal to 150, m is greater than 3 and less than or equal to 50, m is less than or equal to n, and alpha in the same film stack₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The same gradient rule on the same cosine waveform or sine waveform is satisfied independently; for the ith high and low index material unit alpha_iHβ_iL，1≤i≤n,α_iDenotes the number of times of λ/4, β, of the optical thickness of the ith high refractive index material layer in the direction perpendicular to the transparent substrate layer_iThe optical thickness of the ith low-refractive index material layer in the direction perpendicular to the transparent substrate layer accounts for the multiple of lambda/4, lambda is the monitoring wavelength of the film stack, and a light absorbing agent is arranged in the reflecting film system or the transparent substrate layer.

Further, in the same film stack, for the ith high-low refractive index material unit alpha_iHβ_iL, the optical thickness of the high refractive index material layer is alpha_iλ/4, optical thickness of low refractive index material layer of β_iλ/4, refractive index of the high refractive index material layer is N_HThe physical thickness of the high refractive index material layer is D_HThen N is present_H*D_H＝α_iλ/4; the low refractive index material layer has a refractive index N_LThe physical thickness of the low refractive index material layer is D_LThen N is present_L*D_L＝β_iλ/4; wherein alpha is₁，α₂，...，α_mAnd beta_m，...，β₂，β₁Each independently satisfying the same transmutation law on the upper left half chord (such as the chord between 0 and pi/2), the lower left half chord (such as the chord between pi/2 and pi), the upper right half chord (such as the chord between pi and 3 pi/2) and the lower right half chord (such as the chord between 3 pi/2 and 2 pi) of the same sine waveform or cosine waveform in the range of 0-2 pi.

Further, when the narrow-band reflective film is monitored at a wavelength of 455nm, α is_i，β_iThe value range of (A) is as follows: alpha is more than or equal to 0.01_i≤3.2，0.01≤β_i3.2 or less, preferably 0.05 or less alpha_i≤2.8，0.05≤β_iLess than or equal to 2.8; preferably, 0.1. ltoreq. alpha._i≤2.8，0.1≤β_iLess than or equal to 2.8; more preferably, 0.2. ltoreq. alpha._i≤2.7，0.2≤β_i≤2.7。

Furthermore, the number of the high-refractive index material units and the low-refractive index material units of the film stack accounts for 60-99% of the total number of the high-refractive index material units and the low-refractive index material units of the reflecting film system.

Further, the physical thickness of the high refractive index material layer is 1 to 400nm, preferably 10 to 150nm, and the physical thickness of the low refractive index material layer is preferably 1 to 400nm, preferably 10 to 150 nm.

Furthermore, the refractive index of the high refractive index material layer is 1.5-5.0, preferably 1.65-3.0, and the refractive index of the low refractive index material layer is 1.1-1.5, preferably 1.25-1.48.

Further, the refractive index materials forming the high refractive index material layer and the low refractive index material layer are each independently selected from MgF₂、CaF₂Transition metal fluoride, ZnO, TiO₂、TiN、In₂O₃、SnO₃、Cr₂O₃、ZrO₂、Ta₂O₅、LaB₆、NbO、Nb₂O₃、Nb₂O₅、SiO₂、SiC、Si₃N₄、Al₂O₃And a fluorine-containing resin or a hollow silica-containing resin.

Further, the total number of layers of the high refractive index material layer and the low refractive index material layer is 12-60.

Furthermore, the optical admittance of the high-refractive-index material unit is more than 1.5 or 1 & lt, A & lt, 1.2, and the narrow-band reflection film can reflect light with the wavelength of 380-1200 nm in the width range of 20-50 nm.

Further, the film stack further comprises one or more bonding layers, and parts of adjacent film stacks are bonded through the bonding layers.

Further, the adhesive layer is an OCA adhesive layer or a PSA adhesive layer, and the thickness of the adhesive layer is preferably 0.005 to 0.2 mm.

The transparent base material layer is preferably a PET layer, COP layer, COC layer, CPI layer, PMMA layer, PEN layer, PC layer or TAC layer, and preferably has a thickness of 1 to 50 μm.

Further, the light absorber is disposed in at least a part of the high refractive index material layer and/or at least a part of the low refractive index material layer, or the reflective film system further includes one or more light absorber layers disposed adjacent to a part of the high refractive index material layer and/or the low refractive index material layer.

Further, the light absorber is selected from one or more of inorganic light absorbers, organic light absorbers and organic-inorganic composite light absorbers, preferably, the inorganic light absorbers are metal oxides or metal salts, wherein the metal in the metal oxides and metal salts is copper, chromium, iron or cadmium, preferably, the organic light absorbers are phthalocyanine, porphyrin or azo, and the organic-inorganic composite light absorbers are phthalocyanine metal chelates, porphyrin metal chelates or azo metal chelates.

According to another aspect of the present invention, there is provided a narrow band reflective film having a structure represented by: sub-alpha₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL)^N0-Air, wherein,sub represents a transparent substrate layer, Air represents the atmosphere, H is a high-refractive-index material layer, and L is a low-refractive-index material layer; a high refractive index material layer and a low refractive index material layer matched with the high refractive index material layer form a high refractive index material unit and a low refractive index material unit, wherein m is a natural number and is more than 3 and less than or equal to 50; n0 represents the number of film stacks, 1 is more than or equal to N0 is less than 10; for the ith high and low index material unit alpha_iHβ_iL，1≤i≤n，α_iDenotes the number of times of λ/4, β, of the optical thickness of the ith high refractive index material layer in the direction perpendicular to the transparent substrate layer_iThe optical thickness of the ith low-refractive index material layer in the direction vertical to the transparent substrate layer accounts for the multiple of lambda/4, and lambda is the monitoring wavelength of the film stack; alpha is alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The part meeting the same gradient rule on the same sine waveform is a sine gradient area; alpha is alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The part of the sinusoidal wave which does not satisfy the same gradient rule on the same sinusoidal wave is a sinusoidal optimization area, or alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The part satisfying the same gradient rule on the same cosine waveform is a cosine gradient area; alpha is alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The part of the cosine waveform that does not satisfy the same gradient rule is a cosine optimization area,

the sum of the number of the high-refractive-index material layers and the number of the low-refractive-index material layers in the sine gradient region or the cosine gradient region accounts for 60-99% of the sum of the number of the high-refractive-index material layers and the number of the low-refractive-index material layers in the narrow-band reflecting film, and a light absorbing agent is further arranged in the reflecting film system or the transparent substrate layer.

Further, α of the above cosine-tapered region₁，α₂，...，α_mThe upper left half chord degressive beta of cosine waveform₁，β₂，...，β_mThe cosine waveform is increased in the upper right half chord, the cosine optimizing area is positioned at two ends of the cosine gradient area,and alpha in the cosine optimization region₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than alpha in the cosine gradient region₁And beta₁Difference of (a) and_mand beta_mA difference of (d); or alpha of the cosine-tapered region₁，α₂，...，α_mThe left lower half chord degressive beta of cosine waveform₁，β₂，...，β_mThe right lower half chord of the cosine waveform is increased progressively, the cosine optimization areas are positioned at two ends of the cosine tapered area, and alpha in the cosine optimization areas₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than alpha in the cosine gradient region₁And beta₁Difference of (a) and_mand beta_mThe difference of (a).

Further, α of the above-mentioned sinusoidal tapered region₁，α₂，...，α_mSatisfies the increasing of the upper left half chord of sine wave form, beta₁，β₂，...，β_mThe upper right half chord of the sine waveform is decreased progressively, the sine optimization areas are positioned at two ends of the sine gradient area, and alpha in the sine optimization area₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than alpha in the sinusoidal gradient region₁And beta₁Difference of (a) and_mand beta_mA difference of (d); or alpha of a sinusoidally graded region₁，α₂，...，α_mThe left lower half chord degressive, beta, of sine wave shape is satisfied₁，β₂，...，β_mThe right lower half chord of the sine waveform is increased progressively, the sine optimization areas are positioned at two ends of the sine gradient area, and alpha in the sine optimization area₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than alpha in the sinusoidal gradient region₁And beta₁Difference of (a) and_mand beta_mThe difference of (a).

Further, the high and low refractive index materials in the above film stacksThe number of units is modified by a waveform compensation factor, which is equal to alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The cosine waveform of each component accounts for the proportion of the complete quarter waveform, and when alpha is₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The compensation device is characterized in that the factor is 1 when the compensation device independently meets a complete quarter waveform of one of a left upper half-chord waveform, a left lower half-chord waveform, a right upper half-chord waveform and a right lower half-chord waveform, when the factor is less than 1, the number of the compensation high-refractive index material units in each film stack is less than or equal to 1-factor times of the number of the high-refractive index material units in the film stack, and in the compensation high-refractive index material units, the deviation between the optical thickness coefficient of the high-refractive index material layer and the optical thickness coefficient of the low-refractive index material layer and the optical thickness coefficient on the cosine waveform compensated by the compensation high-refractive index material units is less than +/-20%.

By applying the technical scheme of the invention, the distance between the adjacent high refractive index layers and the distance between the adjacent low refractive index material layers are equal to the distance of the spacing layer, the interference reaches the maximum when the distance of the spacing layer is a multiple of lambda/4 according to the Fabry-Perot interference principle, and the period of cosine is gradually increased according to the cosine wave characteristic of the wave particle binary transmission of light, so that the reflection film system is provided with a film system structure of alpha (alpha)₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL) — because the optical thickness coefficients (i.e., α, β) of the high refractive index material layers and the low refractive index material layers of the film stack follow the regular gradient of the cosine waveform, that is, the distance between the adjacent high refractive index layers and the distance between the adjacent low refractive index material layers exhibit the regular gradient of the cosine waveform, the interference effect of a specific wavelength is enhanced, and then the band range in which interference is formed corresponding to the corresponding refractive index will exhibit a tendency of narrowing, that is, the wavelength range of light in which the reflectivity abruptly changes is narrowed to a great extent by the film stack, thereby exhibiting the effect of narrow-band reflection. Meanwhile, according to the change of the number of film stacks in the narrow-band reflecting film, the number of narrow-band reflecting peaks changes correspondingly. In addition, in a reflective film system or throughThe light absorbent is also arranged in the bright substrate layer, so that the light with specific wavelength is absorbed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic cross-sectional view illustrating a narrow-band reflective film provided according to a preferred embodiment of the present invention;

fig. 2 is a schematic cross-sectional view illustrating a narrow-band reflection film provided according to another preferred embodiment of the present invention;

fig. 3 is a schematic sectional view showing a narrow-band reflection film provided according to still another preferred embodiment of the present invention;

FIG. 4 is a simulated test chart showing the light reflectance performance of the narrow-band reflective film of example 1 using the Essential Macleod film system design software according to the present invention;

FIG. 5 is a schematic view showing a transmittance test optical path system structure of a narrow-band reflective film according to embodiment 2 of the present invention;

FIG. 6 is a graph showing the light reflectance obtained as a result of the transmittance test of the narrow-band reflective film according to example 2 of the present invention;

FIG. 7 is a simulated test chart showing the light reflectance performance of the narrow-band reflective film of example 3 using the Essential Macleod film system design software according to the present invention;

FIG. 8 is a simulated test chart showing the light reflectance performance of the narrow-band reflective film of example 4 using the Essential Macleod film system design software according to the present invention;

FIG. 9 is a simulated test chart showing the light reflectance performance of the narrow-band reflective film of example 5 using the Essential Macleod film system design software according to the present invention;

FIG. 10 is a simulated test chart showing the light reflectance performance of the narrow-band reflective film of example 6 using the Essential Macleod film system design software according to the present invention;

FIG. 11 is a simulated test chart showing the light reflection performance of the narrow-band reflective film of example 7 using the Essential Macleod film system design software according to the present invention;

FIG. 12 is a graph showing simulated test of light reflectance performance of the narrow-band reflective film of comparative example 1 using the Essential Macleod film system design software in accordance with the present invention; and

fig. 13 shows a simulated test chart of the light reflection performance of the narrow-band reflective film of comparative example 2 using the Essential mechanical film system design software according to the present invention.

Wherein the figures include the following reference numerals:

10. a transparent substrate layer; 20. stacking the films; 21. a high refractive index material layer; 22. a layer of low refractive index material; 23. a bonding layer;

W₁a tungsten lamp; d₂A deuterium lamp; m₁～M₁₀A reflector; G. a grating; s₁An entrance slit; s₂An exit slit; C. a chopper modulator; r, a reference light colorimetric pool; s, a sample light colorimetric pool; PMT, photomultiplier tube.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

As analyzed in the background of the present application, the reflective film in the prior art has a large reflective bandwidth, which results in poor color gamut, severe whitening, and poor character effect of an optical device using the reflective film, and in order to solve the above problems, the present application provides a narrow-band reflective film, as shown in fig. 1 to 3, the narrow-band reflective film includes a transparent substrate layer 10 and a reflective film system, the reflective film system includes n high-refractive-index material units, the high-refractive-index material units are sequentially stacked on one surface or two opposite surfaces of the transparent substrate layer 10, each high-refractive-index material unit includes a high-refractive-index material layer 21 and a low-refractive-index material layer 22 paired with the high-refractive-index material layer, and the reflective film system includes at least one film system with an i (α is: (α₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL) film stack 20, wherein H represents a high refractive index material layer 21, L represents a low refractive index material layer 22, n and m are positive integers, n is greater than 3 and less than or equal to 150, m is greater than 3 and less than or equal to 50, m is less than or equal to n, and alpha in the same film stack 20₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The same gradient rule on the same cosine waveform or sine waveform is satisfied independently; for the ith high and low index material unit alpha_iHβ_iL，1≤i≤n,α_iDenotes the number of times of λ/4, β, of the optical thickness of the ith high refractive index material layer 21 in the direction perpendicular to the transparent base material layer 10_iIt is shown that the optical thickness of the ith low refractive index material layer 22 in the direction perpendicular to the transparent substrate layer 10 is a multiple of λ/4, λ is the monitoring wavelength of the film stack, and a light absorbing agent is further provided in the reflective film system or in the transparent substrate layer 10.

It should be noted that the sine waveform and the cosine waveform mentioned above in the present application are variation trends (limited to variation trends, and specific values are not limited by quadrants and positive and negative values) of standard sine waveforms and cosine waveforms in a coordinate system, that is, the sine waveform includes upper half strings and lower half strings that are symmetrically arranged, the upper half strings include upper left half strings (e.g., strings between 0 and pi/2) and upper right half strings (e.g., strings between 3 pi/2 and 2 pi), and the lower half strings include lower left half strings (e.g., strings between pi/2 and pi) and lower right half strings (e.g., strings between pi and 3 pi/2); the cosine waveform comprises a left half chord and a right half chord which are symmetrically arranged, the left half chord is a decreasing chord, the right half chord is an increasing chord, the left half chord comprises a left upper half chord and a left lower half chord, and the right half chord comprises a right upper half chord and a right lower half chord.

Since the cosine and sine waveforms are only phase differences. For convenience of description, only the cosine waveform will be described below. At present, in order to realize narrow-band reflection, the prior art is dedicated to increasing the number of layers of high-refractive-index material layers and low-refractive-index material layers in a reflective film system and selecting refractive materials, and the inventor of the present application unexpectedly finds that, when the thickness variation of the high-refractive-index material layers and the low-refractive-index material layers has direct correlation to the bandwidth of a reflection peak, based on the fact that the inventor of the present application deeply studies the thickness variation rule of the high-refractive-index material layers and the low-refractive-index material layers, and finds that a cosine film stack formed by the gradual variation of the optical thickness coefficients of the high-refractive-index material layers and the low-refractive-index material layers following the rule of. The action principle of the method is that:

according to the Fabry-Perot interference principle, when the frequency of the incident light satisfies the resonance condition, the transmission spectrum has a high peak value, which corresponds to a high transmittance. Assuming an interference intensity distribution:

in the formula I₀Is the incident light intensity; r is the energy reflectivity of the reflecting surface; δ is a phase difference between two adjacent coherent light beams, and R + T is 1(R is surface reflectance of the film system, and T is transmittance) depending on an incident light tilt angle. The distance between adjacent high refractive index layers and the distance between adjacent low refractive index material layers are equivalentAt the distance of the spacing layer, according to the Fabry-Perot interference principle, the interference reaches the maximum when the distance of the spacing layer is a multiple of lambda/4, and the period of the cosine gradually increases according to the cosine wave characteristic of the wave particle binary transmission of light, so that the film system structure is alpha (alpha) by arranging the film system structure in the reflective film system₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL) — the film stack 20, since the optical thickness coefficients (i.e., α, β) of the high refractive index material layer 21 and the low refractive index material layer 22 of the film stack 20 follow the law of cosine waveform, i.e., the distance between adjacent high refractive index layers and the distance between adjacent low refractive index material layers exhibit the law of cosine waveform, the interference effect of specific wavelength is enhanced, and then the band range in which interference is formed corresponding to the corresponding refractive index will exhibit a narrowing trend, i.e., the film stack 20 narrows the wavelength range of light in which the reflectivity is sharply changed to a great extent, thereby exhibiting the effect of narrow-band reflection, and further avoiding the defects of poor color gamut of optical devices, severe whitening, and poor character effect caused by large reflection bandwidth. Meanwhile, according to the change of the number of the film stacks 20, the number of the narrow-band reflection peaks changes correspondingly. In addition, a light absorbing agent is further provided in the reflective film system or the transparent substrate layer, thereby realizing absorption of light of a specific wavelength.

The above-mentioned effect can be achieved by changing the optical thickness coefficients of the high refractive index material layer 21 and the low refractive index material layer 22 only by following the same gradient law on the cosine waveform, and in a preferred embodiment of the present application, for the ith high and low refractive index material unit α in the same film stack 20_iHβ_iL, the optical thickness of the high refractive index material layer 21 is alpha_iλ/4, optical thickness of the low refractive index material layer 22 is β_iλ/4, refractive index of the high refractive index material layer 21 is N_HThe physical thickness of the high refractive index material layer 21 is D_HThen N is present_H*D_H＝α_iλ/4; the low refractive index material layer (22) has a refractive index N_LThe low refractive index material layer 22 has a physical thickness D_LThen N is present_L*D_L＝β_iλ/4; wherein alpha is₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The gradient-changing method is characterized in that the gradient-changing method independently satisfies the same gradient rule on the upper left half chord, the lower left half chord, the upper right half chord and the lower right half chord of the same sine waveform and cosine waveform in the range of 0-2 pi. The optical thickness coefficients follow the waveform change rule of four half-chords of the same sine wave in the range, and the difference value of the obtained optical thickness is in a narrower range, so that the narrow-band effect can be better exerted; and the common half-wave hole in the design of the optical film can not appear (in the actual preparation of the optical filter, a reflection peak is often appeared in a band-pass region, namely, a half-wave hole is generally called as the half-wave hole, and is also called as the half-wave falling of the optical filter).

The monitoring wavelength is determined by the incident light wavelength of the usage environment of the film stack, for example, 550nm is selected as the monitoring wavelength of visible light, and 750nm is selected as the monitoring wavelength of infrared light, which can be specifically selected according to the prior art, and is not described herein again.

Alpha when the narrow-band reflecting film takes 455nm as a monitoring wavelength in order to obtain a physical thickness which is easier to realize and control the total physical thickness of the narrow-band reflecting film_i，β_iThe value range of (A) is as follows: alpha is more than or equal to 0.01_i≤3.2，0.01≤β_i3.2, preferably 0.05. ltoreq. alpha_i≤2.8，0.05≤β_i2.8 or less, more preferably 0.1 or less,. alpha._i≤2.8，0.1≤β_iLess than or equal to 2.8; more preferably 0.2. ltoreq. alpha._i≤2.7，0.2≤β_i≤2.7。

In the design of the narrow-band reflective film of the present application, in order to make the reflective film system and the transparent substrate layer 10 have better hardness, adhesiveness, etc., a transitional high-low refractive index layer is generally disposed on the transparent substrate layer 10 before the film stack 20 is disposed, or a transitional layer is also disposed in order to improve the compatibility of the adjacent film stacks 20, for example, a material layer having a higher refractive index is disposed on the transparent substrate layer 10 as an anti-reflection layer. In order to ensure the narrow-band effect of the film stack 20, the number of the high-refractive-index material units in the film stack 20 is preferably 60 to 99% of the total number of the high-refractive-index material units in the reflective film system.

In consideration of the requirements of the structures of the optical filter, the anti-counterfeiting film, etc. for the narrow-band reflective film of the present application, the physical thickness of the high refractive index material layer 21 is preferably 1 to 400nm, preferably 10 to 150nm, and the physical thickness of the low refractive index material layer 22 is preferably 1 to 400nm, preferably 10 to 150 nm.

The refractive index of the high refractive index material layer 21 and the refractive index of the low refractive index material layer 22 can refer to the refractive index of the material for manufacturing the reflective film in the prior art, the refractive index of the high refractive index material layer 21 is 1.5 to 5.0, preferably 1.65 to 3.0, and the refractive index of the low refractive index material layer 22 is 1.1 to 1.5, preferably 1.25 to 1.48.

The refractive index materials forming the high refractive index material layer 21 and the low refractive index material layer 22 having the above refractive indexes may be selected from refractive index materials commonly used in the art, and the refractive index materials forming the high refractive index material layer 21 and the low refractive index material layer 22 are each independently selected from MgF₂、CaF₂Transition metal fluoride, ZnO, TiO₂、TiN、In₂O₃、SnO₃、Cr₂O₃、ZrO₂、Ta₂O₅、LaB₆、NbO、Nb₂O₃、Nb₂O₅、SiO₂、SiC、Si₃N₄、Al₂O₃And a fluorine-containing resin or a hollow silica-containing resin.

In addition, in order to increase the reflectance of the reflective film to a target wavelength, the total number of layers of the high refractive index material layer 21 and the low refractive index material layer 22 is preferably 12 to 60.

Preferably, the optical admittance of the high-refractive-index material unit is greater than 1.5 or 1 < A < 1.2, and the narrow-band reflective film can reflect light with a wavelength in a range of 380-1200 nm (A represents optical admittance) in a width range of 20-50 nm.

Each high refractive index material layer 21 and low refractive index material layer 22 in the film stack 20 of the present application may be formed by coating or sputtering, and is limited by the manufacturing method, when the number of layers of the high refractive index material layer 21 and the low refractive index material layer 22 is large, a part of the high refractive index material layer 21 and the low refractive index material layer 22 may be disposed on different transparent substrate layers 10, and then the high refractive index material layer 21 and the low refractive index material layer 22 on two transparent substrate layers 10 are combined, that is, as shown in fig. 2, preferably, the film stack 20 further includes one or more bonding layers 23, and a part of adjacent film stacks 20 are bonded by the bonding layers 23. After bonding, the excess transparent substrate layer 10 may remain or may be removed, preferably it is removed.

In order to avoid the unnecessary influence of the adhesive layer 23 on light as much as possible, the adhesive layer 23 is preferably an OCA adhesive layer or a PSA adhesive layer, and the thickness of the adhesive layer 23 is more preferably 0.005 to 0.2 mm. So that the adhesive can meet the bonding requirement and ensure enough light transmittance.

In a preferred embodiment of the present application, the transparent substrate layer 10 is a PET layer, a COP layer, a COC layer, a CPI layer, a PMMA layer, a PEN layer, a PC layer, or a TAC layer; the thickness of the transparent substrate layer 10 is preferably 1 to 50 μm. Of course, the transparent base layer 10 may be a hard base material such as glass, and when a flexible material such as a PET layer is selected as the transparent base layer 10, the flexibility of the narrow-band reflection film can be achieved.

The light absorbing agent can be disposed in various ways, for example, the light absorbing agent is disposed in at least a part of the high refractive index material layer 21 and/or at least a part of the low refractive index material layer 22, and the light absorbing agent is dispersed in the high refractive index material layer 21 and/or the low refractive index material layer 22, so that the narrow-band absorption effect is achieved without additionally increasing the thickness of the reflective film system. Alternatively, the light absorber may be provided in a separate structural layer, such as, preferably, as shown in fig. 3, the reflective film system further includes one or more light absorber layers 24, and the light absorber layer 24 is provided adjacent to a portion of the high refractive index material layer 21 and/or the low refractive index material layer 22. Fabricating the light absorber in a separate light absorber layer 24 increases the flexibility in the amount and location of the light absorber.

The light absorber used in the present application is selected from any one or more of inorganic light absorbers, organic light absorbers and organic-inorganic composite light absorbers, preferably, the inorganic light absorbers are metal oxides or metal salts, wherein the metal in the metal oxides and the metal salts is copper, chromium, iron or cadmium, preferably, the organic light absorbers are phthalocyanines, porphyrins or azos, and the organic-inorganic composite light absorbers are phthalocyanines metal chelates, porphyrins metal chelates or azo metal chelates. Such as the ABS series (e.g., ABS-642, ABS-626, etc.) by Exciton, and the FDR series (FDR-001, FDR-002, FDR-003, FDR-004, FDR-005, etc.) by the Shanda chemical industry.

In another exemplary embodiment of the present application, there is provided a narrow band reflective film, which can be referred to fig. 1, and has a structure represented as: sub-alpha₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL)^N0Air, wherein Sub represents the transparent base material layer 10, Air represents the atmosphere, H is the high refractive index material layer 21, and L is the low refractive index material layer 22; a high refractive index material layer 21 and a low refractive index material layer 22 matched with the high refractive index material layer form a high refractive index and low refractive index material unit, m is a natural number, and m is more than 3 and less than 50; n0 represents the number of film stacks, 1 is more than or equal to N0 is less than 10; for the ith high and low index material unit alpha_iHβ_iL，1≤i≤n，α_iDenotes the number of times of λ/4, β, of the optical thickness of the ith high refractive index material layer 21 in the direction perpendicular to the transparent base material layer 10_iDenotes that the optical thickness of the ith low refractive index material layer 22 in the direction perpendicular to the transparent substrate layer 10 is a multiple of λ/4, λ being the monitoring wavelength of the film stack; (ii) a Alpha is alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The part meeting the same gradient rule on the same sine waveform is a sine gradient area; alpha is alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The part of the sinusoidal wave which does not satisfy the same gradient rule on the same sinusoidal wave is a sinusoidal optimization area, or alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The part satisfying the same gradient rule on the same cosine waveform is a cosine gradient area; alpha is alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁Does not satisfy the same cosineThe part of the same gradient rule on the waveform is a cosine optimization area, wherein the sum of the number of high-refractive-index material layers and the number of low-refractive-index material layers in the sine gradient area or the cosine gradient area accounts for 60-99% of the sum of the number of high-refractive-index material layers and the number of low-refractive-index material layers in the narrow-band reflection film.

in the formula I₀Is the incident light intensity; r is the energy reflectivity of the reflecting surface; δ is a phase difference between two adjacent coherent light beams, and R + T is 1(R is surface reflectance of the film system, and T is transmittance) depending on an incident light tilt angle. The distance between the adjacent high refractive index material layers and the distance between the adjacent low refractive index material layers are equal to the distance between the spacer layers, and according to the Fabry-Perot interference principle, the interference is maximized when the distance between the spacer layers is a multiple of lambda/4, and according to the cosine wave characteristic of the wave particle binary transmission of light, the period of the cosine is gradually increased, so that the film system structure is arranged as | (alpha |)₁Hβ₁Lα₂Hβ₂L..α_mHβ_mL) | narrow-band reflective film, because the optical thickness coefficients (i.e., α, β) of the high refractive index material layer 21 and the low refractive index material layer 22 of the narrow-band reflective film follow the law of cosine waveform, i.e., the distance between adjacent high refractive index layers and the distance between adjacent low refractive index material layers show the law of cosine waveform, the interference effect of specific wavelength is enhanced, and then the band range in which interference is formed corresponding to the corresponding refractive index will show the trend of narrowing, i.e., the narrow-band reflective film can narrow the light wavelength range in which the reflectivity appears sharply, thereby the narrow-band reflective effect appears, and further the defects of poor color gamut, severe whitening and poor character effect of an optical device caused by large reflection bandwidth are avoided. At the same time, according to the narrow-band reflective film-in-filmThe number of the piles is changed, and the number of the narrow-band reflection peaks is correspondingly changed. In addition, a light absorbing agent is further provided in the reflective film system or the transparent substrate layer, thereby realizing absorption of light of a specific wavelength.

In a preferred embodiment of the present application, the alpha of the cosine-tapered region₁，α₂，...，α_mThe upper left half chord degressive beta of cosine waveform₁，β₂，...，β_mThe upper right half chord of the cosine waveform is increased progressively, the cosine optimization areas are positioned at two ends of the cosine tapered area, and alpha in the cosine optimization areas₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than alpha in the cosine gradient region₁And beta₁Difference of (a) and_mand beta_mA difference of (d); or alpha of the cosine-tapered region₁，α₂，...，α_mThe left lower half chord degressive beta of cosine waveform₁，β₂，...，β_mThe right lower half chord of the cosine waveform is increased progressively, the cosine optimization areas are positioned at two ends of the cosine tapered area, and alpha in the cosine optimization areas₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than alpha in the cosine gradient region₁And beta₁Difference of (a) and_mand beta_mThe difference of (a). In another preferred embodiment of the present application, α of the sinusoidal tapered region₁，α₂，...，α_mSatisfies the decreasing of the upper left half chord beta of the sine wave₁，β₂，...，β_mThe sine waveform is increased in the upper right half chord, the sine optimization areas are positioned at two ends of the sine gradient area, and alpha in the sine optimization area₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than alpha in the sinusoidal gradient region₁And beta₁Difference of (a) and_mand beta_mA difference of (d); or alpha of a sinusoidally graded region₁，α₂，...，α_mThe left lower half chord degressive, beta, of sine wave shape is satisfied₁，β₂，...，β_mThe right lower half chord of the sine waveform is increased progressively, the sine optimization areas are positioned at two ends of the sine gradient area, and alpha in the sine optimization area₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than alpha in the sinusoidal gradient region₁And beta₁Difference of (a) and_mand beta_mThe difference of (a). Through the arrangement mode, the problem of poor adaptability caused by too large thickness difference between the high refractive index material layer and the low refractive index material layer at the two ends of the sine gradient region or the cosine gradient region is solved.

In order to increase the reflectivity or increase the transmissivity in the non-reflective band, the number of film stacks is also adjusted according to the actual situation, and preferably, the number of high-low refractive index material units in each film stack is modified by a wave form compensation factor, wherein the factor is equal to alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The cosine waveform of each component accounts for the proportion of the complete quarter waveform, and when alpha is₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The compensation device is characterized in that the factor is 1 when the compensation device independently meets a complete quarter waveform of one of a left upper half-chord waveform, a left lower half-chord waveform, a right upper half-chord waveform and a right lower half-chord waveform, when the factor is less than 1, the number of the compensation high-refractive index material units in each film stack is less than or equal to 1-factor times of the number of the high-refractive index material units in the film stack, and in the compensation high-refractive index material units, the deviation between the optical thickness coefficient of the high-refractive index material layer and the optical thickness coefficient of the low-refractive index material layer and the optical thickness coefficient on the cosine waveform compensated by the compensation high-refractive index material units is less than +/-20%.

In order to make it easier for those skilled in the art to implement the present application, a process for manufacturing the reflective film of the present application will be exemplified below.

The method comprises the following steps of taking a high-refractive-index material with a high refractive index as one target material for magnetron sputtering, taking a low-refractive-index material with a low refractive index as the other target material for magnetron sputtering, placing a PET layer in a magnetron sputtering cavity, firstly sputtering a layer of high-refractive-index material and a layer of low-refractive-index material on the PET layer as transition layers, then alternately bombarding the two target materials so as to alternately sputter a high-refractive-index material layer and a low-refractive-index material layer on the transition layers, and stopping sputtering after co-sputtering the high-refractive-index material layer and the low-refractive-index material; repeating the process, stopping sputtering after sputtering the high-refractive-index material layer and the low-refractive-index material layer with the target quantity on the other release PET substrate layer, bonding the exposed high-refractive-index material layer and the exposed low-refractive-index material layer on the two PET substrate layers through OCA glue, and removing the release PET layer to form the reflecting film.

If the film stacks are arranged on both sides of the PET layer, the magnetron sputtering is continuously carried out on the other surface of the formed PET layer of the reflecting film, and the adopted target material can be the same as the steps or different from the steps.

For the above embodiments of specific process parameters of magnetron sputtering, those skilled in the art can refer to the related records of magnetron sputtering methods in the prior art, and details are not repeated here.

The advantageous effects of the present application will be further described below with reference to examples and comparative examples.

Example 1

Simulation experiment data:

an antireflection layer and a reflection film system (formed by alternately overlapping a high refractive index material layer and a low refractive index material layer) are arranged on a PET layer with the thickness of 0.05mm, wherein the central wavelength of incident light is set to be 532nm, the high refractive index material layer is a titanium dioxide layer with the refractive index of 2.354, the low refractive index material layer is a silicon dioxide layer with the refractive index of 1.46, the antireflection layer is composed of the titanium dioxide layer with the optical thickness of lambda/4 and the silicon dioxide layer, and the optical thickness coefficient of the reflection film system is designed as follows:

a first half membrane stack: 0.216H 1.836L 0.303H 1.691L 0.377H 1.591L 0.561H 1.501L 0.583H 1.422L 0.677H 1.358L 0.762H 1.259L 0.851H 1.192L 0.102H 1.102L 1.010H 1.020L 1.106H 0.921L 1.184H 0.886L 1.255H 0.767L 1.346H 0.714L 1.444H 0.634L 1.552H 0.564L 1.625H 0.432L 1.680H 0.416L 1.755H 0.396L 1.902H 0.233L 3.280H 0.905L, wherein the optical thickness coefficient of the high index material layer increases in accordance with the upper right half chord of the cosine waveform and the optical thickness coefficient of the low index material layer decreases in accordance with the upper left half chord of the cosine waveform;

a second half-film stack: 0.306H 2.574L 0.425H 2.369L 0.528H 2.230L 0.784H 2.101L 0.816H 1.987L 0.951H 1.899L 1.066H 1.766L 1.192H 1.667L 1.294H 1.545L 1.412H 1.428L 1.547H 1.289L 1.656H 1.245L 1.758H 1.070L 1.886H 0.996L 2.025H 0.885L 2.175H 0.791L 2.278H 0.603L 2.348H 0.581L 2.457H 0.550L 2.661H 0.326L 4.594H 1.265L, wherein the optical thickness coefficient of the high refractive index material layer increases in accordance with the upper right half chord of the cosine waveform and the optical thickness coefficient of the low refractive index material layer decreases in accordance with the lower left half chord of the cosine waveform;

the optical film was disposed on the above PET layer, and bonded between 0.905L and 0.306H by a PSA having a thickness of 0.1 mm.

The light reflection performance of the narrow-band reflective film was simulated by using the Essential Macleod film system design software, and the simulation results are shown in fig. 4 and table 1.

Example 2

Two half film stacks of the narrow-band reflective film corresponding to example 1 were prepared by magnetron sputtering, and a substrate (on which a 0.05mm PET layer was provided) was cleaned with clean cloth and ethanol. And (3) deflating the vacuum chamber, cleaning the inside of the bell jar by using a dust collector, filling the molybdenum boat with the film material to be evaporated, and recording the name of the film material of each boat. And the substrate is placed on the substrate holder without tilting the substrate. The bell jar is dropped down, and the vacuum chamber is vacuumized according to the operation rules of the film coating machine. When the vacuum degree reaches 7 multiplied by 10^-3And after Pa, pre-melting the film materials in the molybdenum boat in sequence to remove gas in the film materials. At this point, attention is paid to the baffle plate to prevent the substrate from being plated in the pre-melting process. When the vacuum degree meets the requirement, plating is carried out by adopting a method of controlling the optical thickness by adopting a lambda/4 extreme value method, and the control wavelength is placed at 532 nm. Titanium dioxide is first plated on the PET layer of the substrate and the photocurrent indicated by the amplifier will drop as the film layer thickens. When the photocurrent value just begins to rise, the baffle is immediately stopped. Then, the current is reduced to change the electrode,and (3) plating silicon dioxide, wherein when the silicon dioxide is plated, the photocurrent rises along with the increase of the film thickness, the film plating is stopped when the film thickness reaches an extreme value, and the film plating is repeated. When a spacer layer with an optical thickness of lambda/2 is plated, the thickness is doubled and should be stopped when the photocurrent rises and then falls to the extreme value. The latter layers are controlled as the former layers.

And after the coating is finished, stopping heating and vacuumizing according to the operating specification of the coating machine. After half an hour, the vacuum chamber of the film coating machine can be inflated to take out the coated interference filter. Then the coating machine is vacuumized according to the operating specification to keep clean, and finally the machine is stopped. The two half-film stacks were then bonded using a 0.1mm PSA. The measurement is carried out on a TU-1221 double-beam ultraviolet and visible spectrophotometer, a T-lambda curve is directly measured, and three main parameters lambda of the medium interference rate filter are obtained from the curve₀、T_max、Δλ/λ₀. The optical path system of the photometer is shown in FIG. 5. The principle of operation of a spectrophotometer is as follows: black lamp W₁Or deuterium lamps D₂The emitted light passes through a mirror M₁An entrance slit S₁And a mirror M₂After being collimated, the light irradiates the grating G, and the light diffracted by the grating G passes through the reflecting mirror M₃And an emission slit S₂Mirror M₄And a mirror M₅The light chopper C divides the light into two paths: one path is a reflector M₆Reference light colorimetric cell R and reflector M₈The other path is a reflecting mirror M₇Sample optical colorimetric pool S and reflector M₉And a mirror M₁₀And the sample is placed in a sample optical colorimetric pool of the optical path. The two paths of light intensity are alternately received by the photomultiplier and compared in intensity, and the transmittance of the sample is obtained. By changing the rotation angle of the chopper G, different wavelengths can be selected for measurement, so as to obtain a complete transmittance curve, and the transmittance curve is converted into a reflectance curve, which is shown in fig. 6 and table 1.

Example 3

Simulation experiment data:

the optical thickness coefficients of the high refractive index material layer and the low refractive index material layer of the film system were the same as in example 1, with two half film stacks disposed on opposite surfaces of the PET layer. The light reflection performance of the narrow-band reflection film was simulated by using the mclaud film system design software, and the simulation results are shown in fig. 7 and table 1.

Example 4

Simulation experiment data:

an antireflection layer and a reflection film system (formed by alternately overlapping a high refractive index material layer and a low refractive index material layer) are arranged on a PET layer with the thickness of 0.05mm, wherein the central wavelength of incident light is set to 520nm, the high refractive index material layer is a titanium dioxide layer with the refractive index of 2.354, the low refractive index material layer is a silicon dioxide layer with the refractive index of 1.46, the antireflection layer is composed of the titanium dioxide layer with the optical thickness of lambda/4 and the silicon dioxide layer, and the optical thickness coefficient of the reflection film system is designed as follows:

COP 0.251H 1.592L 0.552H 1.487L 0.582H 1.404L 0.675H 1.344L 0.764H 1.253L 0.834H 1.186L 0.916H 1.097L 0.988H 1.026L 1.088H 0.918L 1.165H 0.892L 1.248H 0.765L 1.350H 0.714L 1.446H 0.631L 1.552H 0.565L 1.620H 0.412L 1.250H 1.405L Air，

the light reflection performance of the narrow-band reflective film was simulated by using the Essential Macleod film system design software, and the simulation results are shown in fig. 8 and table 1.

Example 5

Simulation experiment data:

COP 1.667H 1.790L 1.352H 1.284L 1.298H 1.368L 1.474H 1.567L 1.736H 2.055L 1.955H 2.135L 0.554H 1.435L 0.971H 1.206L 1.276H 1.409L 1.487H 1.606L 1.712H 1.874L 1.004H 2.104L 0.947H 1.046L 1.019H 1.135L 1.300H 1.380L 1.518H 1.643L 1.808H 1.878L 1.962H 2.219L 0.800H 0.861L 1.070H 1.194L 1.291H 1.429L 1.516H 1.635L 1.768H 1.877L 2.006H 2.141L 0.792H 1.067L 1.436H 1.901L 0.678H 1.612L 1.566H 1.612L 1.675H 1.837L 1.829H 1.385L Air

the light reflection performance of the narrow-band reflective film was simulated by using the Essential Macleod film system design software, and the simulation results are shown in fig. 9 and table 1.

Example 6

Simulation experiment data:

0.216H 1.836L 0.303H 1.691L 0.377H 1.591L 0.561H 1.501L 0.583H 1.422L 0.677H 1.358L 0.762H 1.259L 0.851H 1.192L 0.102H 1.102L 1.010H 1.020L 1.106H 0.921L 1.184H 0.886L 1.255H 0.767L 1.346H 0.714L 1.444H 0.634L 1.552H 0.564L 1.625H 0.432L 1.680H 0.416L 1.755H 0.396L 1.902H 0.233L 3.280H 0.905L, wherein the optical thickness coefficient of the high index material layer increases in accordance with the upper right-half chord of the cosine waveform and the optical thickness coefficient of the low index material layer decreases in accordance with the upper left-half chord of the cosine waveform.

The light reflection performance of the narrow-band reflective film was simulated by using the Essential Macleod film system design software, and the simulation results are shown in fig. 10 and table 1.

Example 7

The simulation data shows that the film system is designed as in example 1, light absorber ABS-642 is disposed in the high refractive index material layer of 0.377H, uv-531 (2-hydroxy-4-n-octoxybenzophenone) ultraviolet light absorber is disposed in the low refractive index material layer of 1.591L, wherein the light absorber ABS-642 is about 1% by weight in the high refractive index material layer, and the uv-531 (2-hydroxy-4-n-octoxybenzophenone) ultraviolet light absorber is about 1% by weight in the low refractive index material layer. Due to the addition of the ultraviolet absorbent, the offset of the narrow-band reflecting film can be controlled within 50nm when offset is carried out at 0-30 degrees. The light reflection performance of the narrow-band reflective film was simulated by using the Essential mechanical film system design software, and the simulation results are shown in fig. 11 and table 1.

Comparative example 1

0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L。

the light reflection performance of the narrow-band reflective film was simulated by using the Essential Macleod film system design software, and the simulation results are shown in fig. 12 and table 1.

Comparative example 2

0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L 0.377H 1.591L。

the light reflection performance of the narrow-band reflective film was simulated by using the Essential Macleod film system design software, and the simulation results are shown in fig. 13 and table 1.

TABLE 1

As can be seen from the results of fig. 4 to 13, the present application implements an ideal narrow-band reflection effect by controlling the change of the optical thickness of the high refractive index material layer and the low refractive index material layer to change according to the cosine waveform rule, wherein the superposition of the two half film stacks in embodiments 1 and 2 increases the cut-off depth of the repeated cut-off wavelength of the two half film stacks, and the non-repeated portion is filled, thereby implementing the narrow-band reflection of the repeated portion. In addition, it can be seen from the comparison of fig. 4 and 11 and the comparison of the data of example 1 and example 7 that the narrow-band reflection is not affected at all after the addition of the ultraviolet absorber.

Moreover, as can be seen from the data in table 1, the simulation data in example 1 has better consistency with the experimental actual data in example 2, and it can be found from the comparison between example 1 and example 6 that increasing the number of layers of the high refractive index material layer and the low refractive index material layer is beneficial to increasing the reflectivity and reducing the bandwidth of the reflection peak, the color is sharper, and the reflected color effect is more prominent.

In addition, the inventor of the present application further performs different chromaticity detection on the narrow-band reflective film of example 2, and finds that, at a chromaticity of 0 °, the reflective film presents a gem green color, has a sharp color, has an effect similar to a green quantum dot, has a pure color, has a metallic texture, and has no whitening phenomenon, and at a chromaticity of 45 °, a narrow peak of the narrow-band reflective film is shifted to the left, and becomes a weak cyan color, and infrared light is added, and the whole color becomes metallic red, which indicates that the narrow-band reflective film of the present application has a good color change characteristic. The reflective films of comparative examples 1 and 2 had no discoloration and sharp chromaticity.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:

in the formula I₀Is the incident light intensity; r is the energy reflectivity of the reflecting surface; δ is a phase difference between two adjacent coherent light beams, and R + T is 1(R is surface reflectance of the film system, and T is transmittance) depending on an incident light tilt angle. The distance between adjacent high refractive index layers and the distance between adjacent low refractive index material layers are equal to the distance of the spacer layer, and according to the Fabry-Perot interference principle, the interference is maximized when the distance of the spacer layer is a multiple of lambda/4, and according to the cosine wave characteristic of the wave particle binary transmission of light, the period of the cosine is gradually increased, so that the reflection film system is provided with a film system structure of alpha (alpha is alpha)₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL) | film stack, because the optical thickness coefficient of the high refractive index material layer and the low refractive index material layer of the film stack follows the regular gradient of cosine waveform, namely the distance between the adjacent high refractive index layers and the distance between the adjacent low refractive index material layers show the regular gradient of cosine waveform, the interference effect of specific wavelength is enhanced, the wave band range which forms interference corresponding to the corresponding refractive index shows the trend of narrowing, namely the film stack can narrow the light wavelength range with sharp change of reflectivity to a great extent, thereby the occurrence of the phenomenonThe effect of narrow band reflections. Meanwhile, according to the change of the number of the film stacks, the number of the narrow-band reflection peaks correspondingly changes. In addition, a light absorbing agent is further provided in the reflective film system or the transparent substrate layer, thereby realizing absorption of light of a specific wavelength.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A narrow-band reflective film, comprising:

a transparent substrate layer (10);

the reflective film system comprises n high-low refractive index material units, wherein the high-low refractive index material units are sequentially stacked on one surface or two opposite surfaces of the transparent substrate layer (10), each high-low refractive index material unit comprises a high-refractive index material layer (21) and a low-refractive index material layer (22) matched with the high-refractive index material layer, and the reflective film system comprises at least one film system structure of | (alpha)₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL) -film stack (20), wherein H represents a high refractive index material layer (21), L represents a low refractive index material layer (22), n and m are positive integers, n is more than 3 and less than or equal to 150, m is more than 3 and less than or equal to 50, m is less than or equal to n, and alpha in the same film stack (20)₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The same gradient rule on the same cosine waveform or sine waveform is satisfied independently; for the ith high and low index material unit alpha_iHβ_iL，1≤i≤n,α_iDenotes that the optical thickness of the ith high refractive index material layer (21) in the direction perpendicular to the transparent substrate layer (10) is a multiple of lambda/4, beta_iThe optical thickness of the ith low-refractive index material layer (22) in the direction perpendicular to the transparent substrate layer (10) is multiplied by lambda/4, lambda is the monitoring wavelength of the film stack, and the reflecting film system is in orThe transparent substrate layer (10) is also provided with a light absorbent,

in the same stack (20), for the ith high-low refractive index material unit alpha_iHβ_iL, the optical thickness of the high refractive index material layer (21) is alpha_i*λ/4, the optical thickness of the low refractive index material layer (22) being β_i*λ/4, the refractive index of the high refractive index material layer (21) is N_HThe physical thickness of the high refractive index material layer (21) is D_HThen N is present_H*D_H＝α_i*Lambda/4; the low refractive index material layer (22) has a refractive index N_LThe low refractive index material layer (22) has a physical thickness D_LThen N is present_L*D_L＝β_i*Lambda/4; wherein alpha is₁，α₂，...，α_mAnd beta_m，...，β₂，β₁Each independently satisfying the same gradient rule on the upper left half chord, the lower left half chord, the upper right half chord and the lower right half chord of the same sine waveform or cosine waveform in the range of 0-2 pi,

when the narrow-band reflecting film takes 455nm as a monitoring wavelength, alpha_i，β_iThe value range of (A) is as follows: alpha is more than or equal to 0.01_i≤3.2，0.01≤β_i≤3.2。

2. The film of claim 1, wherein 0.05 ≦ α_i≤2.8，0.05≤β_i≤2.8。

3. The narrow band reflective film of claim 2, wherein 0.1 ≦ α_i≤2.8，0.1≤β_i≤2.8。

4. The narrow band reflective film of claim 3, wherein 0.2 ≦ α_i≤2.7，0.2≤β_i≤2.7。

5. The narrow band reflective film according to any one of claims 1 to 4, wherein the number of high and low refractive index material units of the film stack (20) accounts for 60 to 99% of the total number of high and low refractive index material units of the reflective film system.

6. The narrow band reflective film according to any one of claims 1 to 4, wherein the physical thickness of the high refractive index material layer (21) is 1 to 400 nm.

7. The narrow-band reflective film according to claim 6, wherein the physical thickness of the high refractive index material layer (21) is 10 to 150 nm.

8. The narrow band reflective film according to claim 6, wherein the low refractive index material layer (22) has a physical thickness of 1 to 400 nm.

9. The narrow band reflective film of claim 6, wherein the low refractive index material layer (22) has a physical thickness of 10 to 150 nm.

10. The narrow band reflection film according to any one of claims 1 to 4, wherein the high refractive index material layer (21) has a refractive index of 1.5 to 5.0, and the low refractive index material layer (22) has a refractive index of 1.1 to 1.5.

11. The film of claim 10, wherein the layer of high index material (21) has a refractive index of 1.65 to 3.0.

12. The narrow band reflective film of claim 10, wherein the low refractive index material layer (22) has a refractive index of 1.25 to 1.48.

13. The narrow-band reflective film according to any one of claims 1 to 4, wherein the refractive index materials forming the high refractive index material layer (21) and the low refractive index material layer (22) are each independently selected from MgF₂、CaF₂Transition metal fluoride, ZnO, TiO₂、TiN、In₂O₃、SnO₃、Cr₂O₃、ZrO₂、Ta₂O₅、LaB₆、NbO、Nb₂O₃、Nb₂O₅、SiO₂、SiC、Si₃N₄、Al₂O₃And a fluorine-containing resin or a hollow silica-containing resin.

14. The narrow band reflective film according to any one of claims 1 to 4, wherein the total number of layers of the high refractive index material layer (21) and the low refractive index material layer (22) is 12 to 60.

15. The narrow band reflective film of any of claims 1 to 3, wherein the high and low refractive index material units have an optical admittance of greater than 1.5 or 1 < A < 1.2, the film being capable of reflecting light in the 380-1200 nm range of wavelengths over a width range of 20-50 nm.

16. The narrow band reflective film according to any of claims 1 to 4, wherein the film stack (20) further comprises one or more adhesive layers (23), parts of adjacent film stacks (20) being bonded by the adhesive layer (23).

17. The narrowband reflective film according to claim 10, wherein the adhesive layer (23) is an OCA glue layer or a PSA glue layer.

18. The narrow band reflective film according to claim 17, wherein the adhesive layer (23) has a thickness of 0.005 to 0.2 mm.

19. The narrow-band reflective film according to any one of claims 1 to 4, wherein the transparent substrate layer (10) is a PET layer, a COP layer, a COC layer, a CPI layer, a PMMA layer, a PEN layer, a PC layer, or a TAC layer.

20. The narrowband reflective film according to claim 19, wherein the transparent substrate layer (10) has a thickness of 1 to 50 μm.

21. A narrow band reflective film according to claim 1, wherein the light absorber is provided in at least part of the high refractive index material layer (21) and/or at least part of the low refractive index material layer (22), or the reflective film system further comprises one or more light absorber layers (24), the light absorber layers (24) being provided adjacent to part of the high refractive index material layer (21) and/or the low refractive index material layer (22).

22. The narrow band reflective film according to claim 1, wherein the light absorber is selected from any one or more of an inorganic light absorber, an organic light absorber, and an organic-inorganic composite light absorber.

23. The narrowband reflective film of claim 22, wherein the inorganic light absorber is a metal oxide or metal salt, wherein the metal in the metal oxide and metal salt is copper, chromium, iron, or cadmium.

24. The narrow band reflective film of claim 22, wherein the organic light absorber is phthalocyanine, porphyrin or azo, and the organic-inorganic composite light absorber is a phthalocyanine metal chelate, a porphyrin metal chelate or an azo metal chelate.

25. A narrow band reflective film, wherein the structure of the narrow band reflective film is represented as: sub-alpha₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL)^N0-Air, wherein Sub represents the transparent substrate layer (10), Air represents the atmosphere, H is the high refractive index material layer (21), and L is the low refractive index material layer (22); the high-refractive-index material layer (21) and the low-refractive-index material layer (22) matched with the high-refractive-index material layer form a high-refractive-index material unit and a low-refractive-index material unit, m is a natural number, and m is more than 3 and less than or equal to 50; n0 represents the number of film stacks, 1 is more than or equal to N0 is less than 10; for the ith high and low index material unit alpha_iHβ_iL，1≤i≤n，α_iMeans that the ith high refractive index material layer (21) is arranged along the direction perpendicular to the transparent substrate layer (10)The optical thickness in the direction being a multiple of lambda/4, beta_iThe optical thickness of the ith low-refractive index material layer (22) in the direction perpendicular to the transparent substrate layer (10) accounts for the multiple of lambda/4, wherein lambda is the monitoring wavelength of the film stack;

α₁，α₂，...，α_mand beta_m，...，β₂，β₁The part meeting the same gradient rule on the same sine waveform is a sine gradient area; alpha is alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The part of the sinusoidal wave that does not satisfy the same gradient rule on the same sinusoidal wave is a sinusoidal optimization area, or

α₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The part satisfying the same gradient rule on the same cosine waveform is a cosine gradient area; alpha is alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The part of the cosine waveform that does not satisfy the same gradient rule is a cosine optimization area,

wherein the sum of the numbers of the high refractive index material layer and the low refractive index material layer of the sine gradient region or the cosine gradient region accounts for 60-99% of the sum of the numbers of the high refractive index material layer and the low refractive index material layer in the narrow-band reflective film, and a light absorbing agent is further arranged in the reflective film system or the transparent substrate layer (10),

the number of high and low index material units in each film stack is modified by a wave form compensation factor, which is equal to alpha₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The cosine waveform of each component accounts for the proportion of the complete quarter waveform, and when alpha is₁，α₂，...，α_mAnd beta_m，...，β₂，β₁The factor is 1 when the factor independently satisfies the complete quarter waveform of one of the left upper half chord waveform, the left lower half chord waveform, the right upper half chord waveform and the right lower half chord waveform, and when the factor is less than 1In each film stack, the number of the compensation high-refractive index and low-refractive index material units is less than or equal to 1-factor times of the number of the high-refractive index and low-refractive index material units of the film stack, and in the compensation high-refractive index and low-refractive index material units, the deviation between the optical thickness coefficient of the high-refractive index material layer and the optical thickness coefficient of the low-refractive index material layer and the optical thickness coefficient on the cosine waveform compensated by the optical thickness coefficient is less than +/-20%.

26. The narrowband reflective film of claim 25, wherein,

a of the cosine-tapered region₁，α₂，...，α_mThe upper left half chord of the cosine waveform is decreased progressively, beta₁，β₂，...，β_mThe cosine waveform is increased in the upper right half chord, the cosine optimization areas are positioned at two ends of the cosine gradient area, and alpha in the cosine optimization area₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than a in the cosine-tapered region₁And beta₁Difference of (a) and_mand beta_mA difference of (d); or

A of the cosine-tapered region₁，α₂，...，α_mThe left lower half chord degressive beta of the cosine waveform is satisfied₁，β₂，...，β_mThe cosine waveform is increased in the lower right half chord, the cosine optimization areas are positioned at two ends of the cosine gradient area, and alpha in the cosine optimization area₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than a in the cosine-tapered region₁And beta₁Difference of (a) and_mand beta_mThe difference of (a).

27. The narrowband reflective film of claim 25, wherein,

alpha of the sine gradient region₁，α₂，...，α_mSatisfies the increasing of the upper left half chord of the sine wave form, beta₁，β₂，...，β_mThe sine wave form is satisfied with descending of the upper right half chord, the sine optimization areas are positioned at two ends of the sine gradient area, and alpha in the sine optimization area₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than a in the sinusoidal gradient region₁And beta₁Difference of (a) and_mand beta_mA difference of (d); or

Alpha of the sine gradient region₁，α₂，...，α_mThe requirement of the left lower half chord degressive beta of the sine wave shape is met₁，β₂，...，β_mThe sine optimization area is positioned at two ends of the sine gradient area, and alpha in the sine optimization area₁，α₂，...，α_mWith a one-to-one correspondence of beta₁，β₂，...，β_mIs less than a in the sinusoidal gradient region₁And beta₁Difference of (a) and_mand beta_mThe difference of (a).