CN109613637B

CN109613637B - Decorative film

Info

Publication number: CN109613637B
Application number: CN201710939113.1A
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: 2021-10-26
Anticipated expiration: 2037-09-30
Also published as: CN109613637A

Abstract

The invention provides a decorative film. The reflective film of the decorative film includes a hollow refractive material portion, the refractive material portion includes at least one film having an alpha structure₁Hβ₁Lα₂Hβ₂L...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 optical thickness of the ith high refractive index material layer as a multiple of lambda/4, beta_iThe optical thickness of the ith low index material layer is expressed as a multiple of λ/4, λ being the monitored wavelength of the stack. The pattern color displayed by the refraction material part of the decoration film is sharp.

Description

Decorative film

Technical Field

The invention relates to the field of optical film structures, in particular to a decorative film.

Background

The known in-mold decoration forming technology is widely applied to appearance parts such as electronic products, household appliances, automobiles and the like, when the known in-mold decoration forming technology is applied to manufacturing mirror surfaces or color changing effects with dazzling shells, one or more layers of metal or pigment layers are required to be coated on the surface of a base material, if the effect of changing different colors according to different visual angles is required to be achieved, a multi-layer evaporation method is required to be used for manufacturing, but the ductility of a metal coating formed by evaporation is poor, so that the qualification rate of the in-mold decoration forming technology is low, and the integral product quality cannot be improved.

In order to solve the above-mentioned defects of the metal coating, the prior art uses a multilayer optical film as a decorative film based on the interference principle generated by the multilayer optical film, and although the color of the multilayer optical film changes with the change of the viewing angle, the color presented by the multilayer optical film has poor color gamut, severe whitening and no obvious color identification, so that the decorative effect of the multilayer optical film is difficult to achieve the decorative effect of the metal coating.

Disclosure of Invention

The invention mainly aims to provide a decorative film to solve the problem of poor decorative effect of a multilayer optical film in the prior art.

In order to achieve the above object, according to one aspect of the present invention, there is provided a decoration film including: a transparent substrate layer having opposing first and second surfaces; a reflective film disposed on the first surface and/or the second surface of the transparent substrate layer, the reflective film including a hollowed-out refractive material portion, each high-refractive-index material unit including a high-refractive-index material layer and a low-refractive-index material layer paired therewith, the refractive material portion including at least one film system 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_iIt is shown that the optical thickness of the ith low refractive index material layer in the direction perpendicular to the transparent substrate layer is a multiple of λ/4, λ being the monitoring wavelength of the stack.

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 storeIn N_H*D_H＝α_i*Lambda/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, α₁，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 455nm is used as the monitoring wavelength of the decorative film, alpha 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。

Further, 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 refractive-index material part.

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 decorative film can reflect light with the wavelength of 380-1200 nm in the width range of 20-50 nm.

Further, the reflective film system further comprises a transparent leveling layer, the transparent leveling layer is arranged in the gap of the refractive material portion, so that the surface, far away from the transparent substrate layer, of the reflective film system is a plane, and the shape of the refractive material portion is preferably a line, a figure or a character.

Furthermore, the reflecting film system also comprises one or more bonding layers, and part 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, a light absorbing agent is further disposed in the refractive material portion or in the transparent substrate layer, preferably, the light absorbing agent 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 refractive material portion further includes one or more light absorbing agent layers disposed adjacent to a part of the high refractive index material layer and 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 decoration film having a structure represented by: sub-alpha₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL)^N0Air, wherein Sub represents the transparent substrate layer and the decorative film, - [ alpha ], [₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL)^N0L represents a film stack, the film stack is of a hollow structure, Air represents the atmosphere, H represents a high-refractive-index material layer, and L represents 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 perpendicular to the transparent substrate layer accounts for the multiple of lambda/4; 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 which does not meet the same gradient rule on the same cosine waveform 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 in the sine gradient area or the cosine gradient area accounts for the sum of the numbers of the high-refractive-index material layer and the low-refractive-index material layer in the film stackAnd the sum of the number of the low-refractive-index material layers is 60-99%.

Further, α of the above 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 decreased, 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 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 decreased in a descending way, 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 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 are positiveAlpha in chord optimization zone₁，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 number of the high-refractive-index and low-refractive-index material units in each film stack is modified by a wave form compensation coefficient 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%.

Further, the film stack or the transparent substrate layer is further provided with a light absorber, preferably, the light absorber is arranged 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 film stack further comprises one or more light absorber layers, and the light absorber layers are arranged adjacent to a part of the high refractive index material layer and the low refractive index material layer.

Further, above-mentioned decorating film still includes transparent leveling layer, and transparent leveling layer sets up in hollow out construction's space and the surface of the transparent substrate layer of keeping away from of membrane heap and the surface of the transparent substrate layer of keeping away from of transparent leveling layer form a plane, and preferred hollow out construction is line, figure or characters.

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 areCorresponding to the distance of the spacer layer, and according to the Fabry-Perot interference principle, the interference reaches the maximum when the distance of the spacer layer is a multiple of lambda/4, and the period of the cosine is gradually increased 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) — for the film stack, since the optical thickness coefficients (such as α and β) of the high refractive index material layer and the low refractive index material layer 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 of interference corresponding to the corresponding refractive index will exhibit a tendency of narrowing, that is, the film stack will narrow the wavelength range of light with sharp change in reflectivity to a great extent, thereby exhibiting the effect of narrow-band reflection; and because the membrane of this application piles for hollow out construction, consequently demonstrate the fretwork pattern shape of membrane pile, when this decorating film of orthographic view, based on the narrowband reflection effect, this pattern has the bright-colored sharp ornamental effect of colour, and when observation angle skew, the pattern colour changes, and the back pattern colour that changes is still comparatively sharp to more outstanding decorative effect has been realized, can be applied to the decoration of building materials, household electrical appliances 3C product, and realize outstanding discernment decorative effect.

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 decoration film according to a preferred embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view illustrating a decoration film according to another preferred embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view illustrating a decoration film according to still another preferred embodiment of the present invention;

FIG. 4 is a simulated test chart showing the light reflectance performance of the decorative 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 decorative film according to embodiment 2 of the present invention;

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

FIG. 7 is a simulated test chart showing the light reflectance performance of the decorative 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 decorative film of example 4 using the Essential Macleod film system design software in accordance with the present invention;

FIG. 9 is a simulated test chart showing the light reflectance performance of the decorative film of example 5 using the Essential Macleod film system design software in accordance with the present invention;

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

fig. 11 is a graph showing a simulated test of the light reflection performance of the decorative film of example 7 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. a refractive material portion; 21. a high refractive index material layer; 22. a layer of low refractive index material; 23. a bonding layer; 24. a light absorber layer; 30. and a transparent leveling 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, in order to solve the problems of the decorative film in the prior art, which has a decorative effect that is difficult to achieve the decorative effect of the metal plating layer, and the optical device using the decorative film has poor color gamut, severe whitening and poor character effect, the present application provides a decorative film, as shown in fig. 1 and 2, which includes a transparent substrate layer 10 and a reflective film system, wherein the transparent substrate layer 10 has a first surface and a second surface opposite to each other; the reflective film is disposed on the first surface and/or the second surface of the transparent substrate layer 10, the reflective film includes a hollowed-out refractive material portion 20, the refractive material portion 20 includes n stacked high refractive index material units, 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, the refractive material portion 20 includes at least one film system structure of [ (. alpha. ])₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL) a film stack ofH 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 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 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 being the monitoring wavelength of the stack.

It should be noted that the sine waveform and the cosine waveform in the present application are variation trends (limited to the variation trend, and the specific numerical values are not limited by quadrants and positive and negative values) of the standard sine waveform and the cosine waveform in the coordinate system, that is, the sine waveform includes an upper half chord and a lower half chord that are symmetrically arranged, the upper half chord includes an upper left half chord and an upper right half chord, and the lower half chord includes a lower left half chord and a lower right half chord; 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, 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 has conducted intensive research on 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 21 and the low refractive index material layers 22 following the rule of cosine waveform has an outstanding effect on reducing the bandwidth of the reflection peak. 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 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, since the optical thickness coefficients (such as α and β) of the high refractive index material layer 21 and the low refractive index material layer 22 of the film stack follow the regular gradient of 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 cosine waveform, the interference effect of specific wavelength is enhanced, and the band range of interference corresponding to the corresponding refractive index will exhibit a tendency of narrowing, that is, the film stack will narrow the wavelength range of light with sharp change of reflectivity to a great extent, thereby exhibiting the effect of narrow-band reflection, and further avoiding the defects of poor color gamut, severe whitening, and poor character effect of the optical device caused by large reflection bandwidth, and since the film stack of the present application is a hollow structure, the hollow pattern shape of the film stack is displayed, when the decorative film is viewed, based on narrow-band reflection effect, the pattern has vivid and sharp ornamental effect, and when the observation angle is deviated, the pattern has bright and sharp colorThe color is changed, and the changed color of the pattern is still sharper, so that a more prominent decorative effect is realized, the decorative pattern can be applied to the decoration of building materials and household appliance 3C products, and a prominent identification decorative effect is realized. Meanwhile, according to the change of the number of the film stacks, the number of the narrow-band reflection peaks correspondingly changes.

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.

In a preferred embodiment of the present invention, the narrow-band reflection and decoration effects 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 according to the same gradient law on the sine waveform or the cosine waveform_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 practical preparation of the optical filter, a reflection usually appears in a band-pass area, namely, a position of half of the central wavelength of a reflection bandPeaks, commonly referred to as half-wave apertures, also referred to as half-wave dips of the filter).

Alpha at 455nm as the monitor wavelength for the decorative film in order to obtain a more easily achievable physical thickness and to control the total physical thickness of the decorative 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 decorative film design of this application, in order to make the hardness, the adhesion etc. of reflective film system and transparent substrate layer 10 better, generally can set up the high low refractive index layer of transition on transparent substrate layer 10 before setting up the membrane stack, perhaps in order to improve the adaptability of adjacent membrane stack, also can set up the transition layer, in order to guarantee the narrowband effect of membrane stack, the quantity of the high low refractive index material unit in preferred above-mentioned membrane stack accounts for 60 ~ 99% of the total number of the high low refractive index material unit of refractive index material portion.

In consideration of the application requirements of the decoration 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 decorative film can reflect light with a wavelength in the range of 380-1200 nm (A represents the optical admittance) in the width range of 20-50 nm.

In addition, in order to improve the application stability of the decorative film of the present application, it is preferable that the reflective film system further includes a transparent flattening layer 30, and the transparent flattening layer 30 is disposed in the gap of the refractive material portion 20 so that the surface of the reflective film system away from the transparent base material layer is a flat surface. Of course, if the transparent leveling layer 30 is not provided, since the physical thickness of the film stack is in the nanometer level, the negative effect is not obvious during the application, the hollow film stack can be protected after the transparent leveling layer 30 is provided, and the application stability and the service life of the decorative film are improved. The decorative film of the present application can decorate the grain effect, various figures, characters, etc., and thus the shape of the refraction material portion 20 is preferably grain, figure, or character.

Each of the high refractive index material layer 21 and the low refractive index material layer 22 in the reflective film system of the present application may be formed by coating or sputtering, which 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 the two transparent substrate layers 10 are combined, that is, as shown in fig. 2, preferably, the reflective film system further includes one or more bonding layers 23, and a part of adjacent film stacks 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 substrate layer 10 may be a hard substrate such as glass, and when a flexible material such as a PET layer is selected as the transparent substrate layer 10, the decorative film can be made flexible.

A light absorbing agent is further disposed in the refractive material portion 20 or in the base material layer to further absorb a specific wavelength. 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 absorbers may be provided in a separate structural layer, such as is preferred as shown in fig. 3, the refractive material section 20 further including one or more light absorber layers 24, the light absorber layers 24 being provided adjacent to portions of the high refractive index material layer 21 and 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 is mainly derived from the existing light absorber materials, for example, the light absorber is preferably selected from one or more of inorganic light absorbers, organic light absorbers and organic-inorganic composite light absorbers, the inorganic light absorber is preferably a metal oxide or a metal salt, wherein the metal in the metal oxide and the metal salt is copper, chromium, iron or cadmium, the organic light absorber is preferably phthalocyanine, porphyrin or azo, and the organic-inorganic composite light absorber is preferably phthalocyanine metal chelate, porphyrin metal chelate or azo metal chelate.

In another exemplary embodiment of the present application, there is provided a decorative film, which may be referred to in fig. 1, and has a structure represented by: sub-alpha₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL)^N0Air, wherein Sub represents the transparent substrate layer 10, - (. alpha.), (alpha.)₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL)^N0| represents a film stack which is a hollow structure, Air represents the atmosphere, H represents a high refractive index material layer 21, and L represents a 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; 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 which does not meet the same gradient rule on the same cosine waveform 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 area or the cosine gradient area accounts for the high refractive index of the film stack60-99% of the sum of the number of the material layers with the low refractive indexes.

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) — since the optical thickness coefficients (such as α and β) of the high refractive index material layer 21 and the low refractive index material layer 22 of the decorative film 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 tends to be narrowed, that is, the decorative film 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 since the film stack of the present application is a hollow structure, the shape of the hollow pattern of the film stack is displayed, and when the decorative film is viewed in front view, the pattern has a vivid and sharp ornamental effect based on the narrow-band reflection effect, and when the viewing angle is shifted, the color of the pattern is changed, and the changed color of the pattern is still sharper, thereby realizing more prominent decorative effect, and the pattern can be used for decorationThe method is applied to the decoration of building materials and household appliance 3C products, and realizes the outstanding recognition decoration effect. Meanwhile, according to the change of the number of film stacks in the decorative film, the number of narrow-band reflection peaks changes correspondingly.

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 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). 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 absorb light of a specific wavelength, it is preferable that a light absorbing agent is further provided in the film stack or the transparent substrate layer. The light absorbing agent is arranged 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, 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 realized on the basis of not additionally increasing the thickness of the reflecting film system. Or the stack may further include one or more light absorber layers 24, the light absorber layers 24 being disposed adjacent portions of the high index material layer 21 and the low 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.

In order to improve the application stability of the decorative film of the present application, it is preferable that the decorative film further includes a transparent planarization layer 30, and the transparent planarization layer 30 is disposed in the hollow space and the surface of the film stack far away from the transparent substrate layer 10 and the surface of the transparent planarization layer 30 far away from the transparent substrate layer 10 form a plane. Of course, if the transparent leveling layer 30 is not provided, since the physical thickness of the film stack is in the nanometer level, the negative effect is not obvious during the application, the hollow film stack can be protected after the transparent leveling layer 30 is provided, and the application stability and the service life of the decorative film are improved. The decorative film of the present application can decorate the grain effect, various figures, characters, etc., and thus the shape of the refraction material portion 20 is preferably grain, figure, or character.

Preferably, the hollow structure is a line, a figure or a character.

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, and arranging a mask plate on the PET layer, wherein the mask plate is of a hollow structure, and the pore part of the mask plate is used for the high-refractive-index material and the low-refractive-index material to pass through so as to form a refractive material part. Firstly, sputtering a layer of high-refractive-index material and a layer of low-refractive-index material on a PET layer to serve as a transition layer, then bombarding two targets alternately to alternately sputter a high-refractive-index material layer and a low-refractive-index material layer on the transition layer, and stopping sputtering after co-sputtering the high-refractive-index material layer and the low-refractive-index material layer with target quantities.

When the number of the high-refractive-index material layers and the low-refractive-index material layers formed in the process is insufficient, the process is repeated, the sputtering is stopped after the high-refractive-index material layers and the low-refractive-index material layers in the target number are sputtered on the other release PET substrate layer, the exposed high-refractive-index material layers and the exposed low-refractive-index material layers on the two PET substrate layers are bonded through OCA glue, the release PET layers are removed, and the reflecting film is formed. The OCA glue can be used as a bonding layer or a transparent flat layer.

If the high-low refractive index material film groups are arranged on both sides of the PET layer, the magnetron sputtering is continuously carried out on the other surface of the PET layer of the formed reflection 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:

a PET layer with a thickness of 0.05mm was used as a transparent substrate layer. The method comprises the following steps of arranging a film stack (formed by alternately overlapping a high-refractive-index material layer and a low-refractive-index material layer) of an anti-reflection layer and a reflection film system on a PET (polyethylene terephthalate) layer, setting the shape pattern of the film stack to be a landscape pattern, filling hollow gaps in the film stack with PET, setting the central wavelength of incident light to be 532nm, setting the high-refractive-index material layer to be a titanium dioxide layer with the refractive index of 2.354, setting the low-refractive-index material layer to be a silicon dioxide layer with the refractive index of 1.46, wherein the anti-reflection layer consists of the titanium dioxide layer with the optical thickness of lambda/4 and the silicon dioxide layer, and setting the optical thickness coefficient of the reflection film system to be:

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 above decorative film was simulated using the Essential mechanical film system design software, and the simulation results are shown in fig. 4 and table 1.

Example 2

The two half film stacks of the decorative film corresponding to the embodiment 1 are manufactured by adopting a magnetron sputtering process, and the substrate is cleaned by using clean cloth and ethanol. Designing a mask plate with a gap of 'landscape pattern'.

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 inclining the substrate, and the mask plate is placed on the cleaned 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 return, the photocurrent will be immediatelyThe baffle is blocked. And then, reducing the current to change the electrode, plating silicon dioxide, wherein when the silicon dioxide is plated, the photocurrent rises along with the increase of the film thickness, stopping plating the film when the extreme value is reached, and repeating the steps to plate the film. 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 above decorative film was simulated using the Essential mechanical film system design software, and the simulation results are shown in fig. 7 and table 1.

Example 4

Simulation experiment data:

a PET layer with a thickness of 0.05mm was used as a transparent substrate layer. The method comprises the following steps of arranging a film stack (formed by alternately overlapping a high-refractive-index material layer and a low-refractive-index material layer) of an anti-reflection layer and a reflection film system on a PET (polyethylene terephthalate) layer, setting the shape of the film stack to be 'KDX', filling hollow gaps in the film stack with PET, setting the central wavelength of incident light to be 520nm, setting the high-refractive-index material layer to be a titanium dioxide layer with the refractive index of 2.354, setting the low-refractive-index material layer to be a silicon dioxide layer with the refractive index of 1.46, wherein the anti-reflection layer consists of the titanium dioxide layer with the optical thickness of lambda/4 and the silicon dioxide layer, and setting the optical thickness coefficient of the reflection film system to be:

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 above decorative film was simulated using the Essential mechanical film system design software, and the simulation results are shown in fig. 8 and table 1.

Example 5

Simulation experiment data:

a PET layer with a thickness of 0.05mm was used as a transparent substrate layer. The anti-reflection film comprises a PET layer, a film stack (formed by alternately overlapping a high-refractive-index material layer and a low-refractive-index material layer) of a reflection film system is arranged on the PET layer, wherein the shape of the film stack is set to be a tree-texture stripe, hollow gaps in the film stack are filled with PET, the central wavelength of incident light is set to be 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 anti-reflection layer consists 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 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 above decorative film was simulated using the Essential mechanical film system design software, and the simulation results are shown in fig. 9 and table 1.

Example 6

Simulation experiment data:

a PET layer with a thickness of 0.05mm was used as a transparent substrate layer. The anti-reflection film comprises a PET layer, a film stack (formed by alternately overlapping a high-refractive-index material layer and a low-refractive-index material layer) of a reflection film system is arranged on the PET layer, wherein the shape of the film stack is set to be a petal pattern, hollow gaps in the film stack are filled with PET, 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 anti-reflection 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:

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 above decorative film was simulated using the Essential mechanical film system design software, and the simulation results are shown in fig. 10 and table 1.

Example 7

The film system design was the same as example 2, where light absorber ABS-642 was placed in the high refractive index material layer of 0.377H, uv-531 (2-hydroxy-4-n-octoxybenzophenone) uv absorber was placed in the low refractive index material layer of 1.591L, where the weight percentage of light absorber ABS-642 in the high refractive index material layer was about 1%, and the weight percentage of uv-531 (2-hydroxy-4-n-octoxybenzophenone) uv absorber in the low refractive index material layer was about 1%. 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 rest is the same as example 2. The resulting light reflectance curve is shown in FIG. 11.

Comparative example 1

Printing an ink layer on a PET layer with the thickness of 0.150mm to form a plurality of groups of KDX characters, arranging a PET flattening layer on the characters, and enabling the total thickness of the whole PET layer and the PET flattening layer to be 0.250 mm.

TABLE 1

As can be seen from the results of fig. 4 to 11, the present application adjusts and controls 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, so as to achieve an ideal narrow-band reflection effect, 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, so as to achieve the narrow-band reflection of the repeated portion, and when light passes through, a landscape pattern is displayed, and when viewed from the front, the effect of vivid and sharp colors is achieved, and when the light deviates a certain angle, the color of the pattern changes. 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, so that 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 decorative 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 weak cyan, and infrared rays are added, so that the overall color becomes metallic red, which indicates that the decorative film of the present application has a high-quality color-changing characteristic. Comparative example 1 is a conventional decorative film, having no discoloration and sharp color characteristics.

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) due to high refraction of the film stackThe optical thickness coefficients of the rate material layer and the low refractive index material layer follow 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, so that the interference effect of specific wavelength is enhanced, the wave band range forming interference corresponding to the corresponding refractive index shows the trend of narrowing, namely the film stack can narrow the light wavelength range with sharp reflectivity to a great extent, thereby the narrow-band reflection effect is generated, and the hollow pattern shape of the film stack is displayed because the film stack is in a hollow structure, when the decorative film is looked forward, the pattern has the ornamental effect of bright and sharp color based on the narrow-band reflection effect, when the observation angle deviates, the pattern color changes, and the changed pattern color is still comparatively large, therefore, the method realizes a more prominent decorative effect, can be applied to the decoration of building materials and household appliance 3C products, and realizes a prominent identification decorative effect. Meanwhile, according to the change of the number of the film stacks, the number of the narrow-band reflection peaks correspondingly changes.

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. An ornamental film, comprising:

a transparent substrate layer (10) having opposing first and second surfaces;

the reflective film system sets up on the first surface and/or the second surface of transparent substrate layer (10), the reflective film system includes refractive material portion (20) of fretwork, refractive material portion (20) include n superpose high low refractive index material unit, each high low refractive index material unit includes a high refractive index material layer (21) and a low refractive index material layer (22) of mating with it, refractive material portion (20) include that at least one membrane system structure is | (alpha)₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL) -wherein H represents the high refractive index material layer (21), L represents the 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 the same is the alpha in the 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 said high and low refractive index material unit α_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_iMeans 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 lambda/4, lambda being the monitoring wavelength of the film stack,

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 (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,

alpha when the decorative film takes 455nm as a monitoring wavelength_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 decorative film of claim 1, wherein the decorative film has an α of 0.05 ≦ α at a monitoring wavelength of 455nm_i≤2.8，0.05≤β_i≤2.8。

3. The decorative film of claim 2, wherein the decorative film has an α of 0.1. ltoreq. at a monitoring wavelength of 455nm_i≤2.8，0.1≤β_i≤2.8。

4. The decorative film of claim 3, wherein the decorative film has an α of 0.2. ltoreq. at a monitoring wavelength of 455nm_i≤2.7，0.2≤β_i≤2.7。

5. An ornamental 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 accounts for 60 to 99% of the total number of high and low refractive index material units of the refractive index material portion.

6. An ornamental film according to any one of claims 1 to 4, wherein said high refractive index material layer (21) has a physical thickness of 1 to 400 nm.

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

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

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

10. An ornamental film according to any one of claims 1 to 4, wherein said high refractive index material layer (21) has a refractive index of 1.5 to 5.0, and said low refractive index material layer (22) has a refractive index of 1.1 to 1.5.

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

12. An ornamental film according to claim 10, wherein said low refractive index material layer (22) has a refractive index of 1.25 to 1.48.

13. An ornamental film according to any one of claims 1 to 4, wherein the refractive index materials forming said high refractive index material layer (21) and said 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. An ornamental film according to any one of claims 1 to 4, wherein the total number of layers of said high refractive index material layer (21) and said low refractive index material layer (22) is 12 to 60.

15. The decoration film according to any one of claims 1 to 4 wherein the high and low refractive index material unit has an optical admittance of more than 1.5 or 1 < A < 1.2, A representing the optical admittance, the decoration film being capable of reflecting light having a wavelength in the range of 380 to 1200nm in a width range of 20 to 50 nm.

16. The decoration film according to any one of claims 1 to 4, wherein the reflection film train further comprises a transparent flattening layer (30), the transparent flattening layer (30) being provided in the gap of the refractive material portion (20) so that the surface of the reflection film train remote from the transparent base material layer is a plane.

17. An ornamental film according to claim 16, wherein said refracting material portion (20) has a shape of a grain, a figure or a letter.

18. An ornamental film according to claim 16, wherein said reflective film stack further comprises one or more adhesive layers (23), and parts of adjacent said film stacks are adhered by said adhesive layers (23).

19. An ornamental film according to claim 18, wherein said adhesive layer (23) is an OCA glue layer or a PSA glue layer.

20. An ornamental film according to claim 19, wherein said adhesive layer (23) has a thickness of 0.005 to 0.2 mm.

21. The decorative 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.

22. The decorative film according to any one of claims 1 to 4, wherein the thickness of the transparent substrate layer (10) is 1 to 50 μm.

23. An ornamental film according to claim 1, wherein a light absorbing agent is further provided in said refractive material portion (20) or in said transparent substrate layer.

24. An ornamental film according to claim 23, wherein said light absorber is provided in at least a part of said high refractive index material layer (21) and/or at least a part of said low refractive index material layer (22), or said refractive material portion (20) further comprises one or more light absorber layers (24), said light absorber layer (24) being provided adjacent to a part of said high refractive index material layer (21) and said low refractive index material layer (22).

25. The decoration film according to claim 23 or 24 wherein, the light absorber is selected from any one or more of inorganic light absorbers, organic light absorbers and organic-inorganic composite light absorbers.

26. The decorative film according to claim 25, wherein the inorganic light absorber is a metal oxide or a metal salt, wherein a metal in the metal oxide and the metal salt is copper, chromium, iron, or cadmium.

27. The decorative film according to claim 25, wherein the organic light absorber is phthalocyanine, porphyrin or azo, and the organic-inorganic composite light absorber is phthalocyanine metal chelate, porphyrin metal chelate or azo metal chelate.

28. An ornamental film, wherein a structure of the ornamental film is represented as: sub-alpha₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL)^N0| Air, wherein Sub represents the transparent substrate layer (10), | (α)₁Hβ₁Lα₂Hβ₂L...α_mHβ_mL)^N0The method comprises the following steps of (a) representing a film stack, wherein the film stack is of a hollow structure, Air represents the atmosphere, H is a high-refractive-index material layer (21), and L is a 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_iDenotes that the optical thickness of the ith high refractive index material layer (21) in the direction perpendicular to the transparent substrate layer 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 accounts for the multiple of lambda/4, and lambda is the monitoring wavelength of the film stack;

α₁，α₂，...，α_mand beta_m，...，β₂，β₁Well-fullThe part which is consistent with 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 number of the high refractive index material layers and the number of the low refractive index material layers of the sine tapered region or the cosine tapered region accounts for 60-99% of the sum of the number of the high refractive index material layers and the low refractive index material layers in the film stack,

a of the cosine-tapered region₁，α₂，...，α_mThe upper left half chord of the cosine waveform is increased and decreased gradually, 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 of the cosine waveform is increased and decreased gradually, beta₁，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).

29. The decorative film of claim 28,

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).

30. The decorated film of claim 28, wherein the number of high and low index material units in each film stack is modified by a wave form compensation factor, said factor being equal to α₁，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 comprises a compensation high-refractive index material unit and a compensation low-refractive index material unit, wherein the compensation high-refractive index material unit is 1-factor times of the number of high-refractive index material units of the film stack, and in the compensation high-refractive index material unit, the optical thickness coefficient of the high-refractive index material layer, the optical thickness coefficient of the low-refractive index material layer and the deviation of the optical thickness coefficient on the cosine waveform compensated by the compensation high-refractive index material unit are less than +/-20%.

31. The decorative film of claim 28, wherein a light absorber is further disposed in the film stack or the transparent substrate layer.

32. The decorative film according to claim 31, wherein the light absorber is disposed in at least a portion of the high refractive index material layer (21) and/or at least a portion of the low refractive index material layer (22), or the film stack further comprises one or more light absorber layers (24), the light absorber layers (24) being disposed adjacent to a portion of the high refractive index material layer (21) and the low refractive index material layer (22).

33. The decorative film according to claim 28, further comprising a transparent planarization layer (30), wherein the transparent planarization layer (30) is disposed in the hollow-out structure, and the surface of the film stack far from the transparent substrate layer (10) and the surface of the transparent planarization layer (30) far from the transparent substrate layer (10) form a plane.

34. The decoration film of claim 33, wherein the hollow structure is a line, a figure or a letter.