CN111098560A

CN111098560A - Photochromic gradient film and preparation method thereof

Info

Publication number: CN111098560A
Application number: CN201911386983.6A
Authority: CN
Inventors: 陈娟; 陈征; 王忠英
Original assignee: Shine Optoelectronics Kunshan Co Ltd
Current assignee: Shine Optoelectronics Kunshan Co Ltd
Priority date: 2019-12-29
Filing date: 2019-12-29
Publication date: 2020-05-05

Abstract

The application provides a photochromic gradient film and a preparation method thereof, wherein the photochromic gradient film comprises a base material and a photochromic layer, the photochromic layer is stacked on one side of the base material and contains a photochromic material, and the photochromic layer shows color gradient in a photochromic state. The photochromic gradual change film has a simple structure, a simple preparation method and no additional scarce energy. The color change can be realized by utilizing the light energy, the defect that the traditional gradual change film is invariable is overcome, and the time experience is improved.

Description

Photochromic gradient film and preparation method thereof

Technical Field

The invention relates to an optical film technology, in particular to a photochromic gradient film and a preparation method thereof.

Background

With the improvement of living standard, people have higher requirements on appearance decoration of various consumer products, for example, the appearance of mobile phones has become one of the main determinants of whether products are sold well. In recent years, the introduction of the gradient color brings new changes to the decoration of the mobile phone rear cover, so that the mobile phone rear cover becomes more aesthetic and attractive.

The color of the decorative film used in the market is fixed. To meet the increasing demands of consumers on the appearance of products, new design elements need to be introduced.

Therefore, there is a need for a new photochromic gradient film and a method for preparing the same.

Disclosure of Invention

The invention aims to: the new photochromic gradual change film is provided, the film changes color under the action of light, and the film has changeable visual effect of color gradual change, so that the defect that the color of the existing decorative film (gradual change film) is unchanged is overcome, and better photochromic gradual change color effect is achieved.

Another object of the present invention is to: the preparation method reduces the difficulty of the manufacturing process and the requirements on materials required by manufacturing, thereby improving the straight-going rate of manufacturing the photochromic gradient film.

In order to achieve the purpose, the technical scheme adopted by the application is as follows,

a photochromic gradual change film is characterized by comprising a base material and a photochromic layer,

the photochromic layer is stacked on one side of the base material, and contains a photochromic material, and the photochromic layer shows color gradual change in a photochromic state.

Preferably, the photochromic layer has a thickness gradually increasing or decreasing from one side to the other side, and contains a photochromic material therein, and exhibits a color gradient in a color-changing state.

Preferably, the photochromic layer has uniform thickness, a plurality of grooves are arranged in the photochromic layer, the grooves are filled with photochromic materials, and the photochromic gradual change film presents color gradual change in a photochromic state through one or a combination of the depth, the width and the duty ratio of the gradually changed grooves.

Preferably, the substrate is selected from one or a combination of glass, quartz, transparent plastic substrate, ceramic substrate, PET film, transparent PI film, PEN film, nano cellulose paper and explosion-proof film.

Preferably, the photochromic layer contains 2 or more than 2 photochromic materials, and the color gradient is presented by the superposition combination of colors in a color changing state.

Preferably, the photochromic layer, further comprises a gradient color layer,

the thickness of the gradient color layer is gradually increased or decreased from one side to the other side, or the thickness of the gradient color layer is consistent, a plurality of grooves which are gradually arranged are arranged in the gradient color layer, pigment is filled in the grooves,

the color gradient is realized by the combination of the gradient color layer and the photochromic layer in the color changing state.

Preferably, the thickness of the photochromic layer is gradually increased or decreased from one side to the other side, or the thickness of the photochromic layer is uniform,

Preferably, the gradient color layer comprises at least one gradient color film layer or at least one ultraviolet ray resistant gradient color layer.

Preferably, the gradient color layer and the photochromic layer are disposed on the same side of the substrate, or the gradient color layer and the photochromic layer are disposed on both sides of the substrate.

Preferably, the photochromic gradient film further comprises a micro-nano structure layer, wherein the micro-nano structure layer is arranged on one side of the base material and comprises a plurality of micro-nano structures which are arranged in a protruding and/or recessed mode.

Preferably, the photochromic gradient film further comprises a reflecting layer and/or a coloring layer, which are laminated on the micro-nano structure layer.

Preferably, the photochromic gradient film also comprises photochromic ink which is colorless or colored by the photochromic material.

Preferably, the photochromic gradient film also comprises a photochromic ink containing red, yellow, blue and purple phases.

The embodiment of the application provides a preparation method of photochromic gradual change film, which is characterized by comprising the steps of arranging a photochromic layer on one side of a substrate, namely forming the photochromic layer with the thickness gradually increased or decreased from one side by using photochromic materials through inkjet printing, screen printing or offset printing, or impressing a texture on the substrate by using transparent impressing glue, wherein the texture comprises a groove with gradually changed depth and/or width and/or duty ratio, and filling photochromic ink into the groove.

Preferably, the manufacturing method is characterized in that another photochromic layer is formed on the other side of the substrate or on the photochromic layer.

Preferably, the grooves have a thickness ranging from 5.5 μm to 3.5 μm to 0.5 μm, and the photochromic material in the grooves has a thickness ranging from 3.5 μm to 2 μm to 0.2 μm.

The embodiment of the application provides a preparation method of a photochromic gradient film, which is characterized by comprising the following steps:

s11, forming a gradient color layer on one side of a base material;

s12, forming a photochromic layer on the other side of the base material or the gradient color layer; or

S11, forming a photochromic layer on one side of a base material;

and S12, forming a gradient color layer on the other side of the base material or on the photochromic layer.

Preferably, in the method, the photochromic layer has a uniform or graded thickness.

Preferably, in the preparation method, the gradient color layer and the photochromic layer are respectively formed by nanoimprint, ink-jet printing, screen printing, offset printing or coating process.

Advantageous effects

Compared with the scheme in the prior art, the photochromic gradual change film provided by the embodiment of the application has the function of color gradual change, and the color of the film is changed under the condition of irradiation of light (such as sunlight), so that the color gradual change is presented under the color change state. Meanwhile, the photochromic gradient film is low in manufacturing process difficulty, the visual effect of photochromic and gradient can be achieved by utilizing a single-layer photochromic structure during manufacturing, or on the basis, the photochromic gradient layer or another photochromic layer is further optimized to achieve a better visual effect of photochromic and gradient.

Drawings

In order to more clearly illustrate the embodiments of the present specification or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the specification, and for those skilled in the art, other drawings can be obtained according to the drawings without inventive exercise:

FIG. 1 is a schematic structural view of a photochromic gradient film according to a first embodiment of the present application;

FIG. 2 is a schematic structural diagram of a photochromic gradient film according to a second embodiment of the present application;

FIG. 3 is a schematic structural diagram of a photochromic gradient film according to a third embodiment of the present application;

FIG. 4 is a schematic structural diagram of a fourth embodiment of a photochromic gradient film;

FIG. 5 is a schematic structural diagram of a fifth embodiment of a photochromic gradient film of the present application;

FIG. 6 is a schematic structural diagram of a photochromic gradient film according to a sixth embodiment of the present application;

FIG. 7 is a schematic structural diagram of a photochromic gradient film according to a seventh embodiment of the present application;

FIG. 8 is a schematic structural view of a photochromic gradient film according to an eighth embodiment of the present application;

FIG. 9 is a schematic structural view of a photochromic gradient film according to a ninth embodiment of the present application;

FIG. 10 is a schematic structural view of a photochromic gradient film according to a tenth embodiment of the present application;

fig. 11 is a schematic structural view of a photochromic gradient film according to an eleventh embodiment of the present application.

Detailed Description

In order to make those skilled in the art better understand the technical solutions proposed by the present invention, the technical solutions in the embodiments of the present specification will be clearly and completely described below with reference to the drawings in the embodiments of the present specification, and it is obvious that the described embodiments are only a part of the embodiments in the present specification, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from one or more of the embodiments described herein without making any inventive step, shall fall within the scope of protection of the present invention.

The application provides a photochromic gradual change film, and the photochromic gradual change film changes color under the light (such as sunlight, ultraviolet light and the like) occasion, realizes the changeable gradual change effect, and overcomes the defect that the color of the traditional gradual change film is unchanged. The photochromic phenomenon is that the color changes under the irradiation of light sources such as sunlight or ultraviolet light, and the photochromic phenomenon can be restored to the original color reversibly after the light disappears.

The photochromic gradient film proposed in the present application is described in detail below with reference to the accompanying drawings.

As shown in fig. 1, which is a schematic structural diagram of a photochromic gradient film according to an embodiment of the present application, the photochromic gradient film 10 includes a substrate 11 and a photochromic layer 12, wherein the photochromic layer 12 is disposed on the substrate 11. In the present embodiment, the substrate 11 is a transparent substrate selected from glass, quartz, transparent plastic substrates, ceramics, etc., or selected from PET films, transparent PI films, PEN films, nanocellulose papers, explosion-proof films, etc. The photochromic layer comprises a photochromic material that exhibits a color gradient characteristic in one color change state. The photochromic layer has a thickness gradually increasing from one side to the other side, so that its color shows a gradual change characteristic under the irradiation of light due to the influence of the thickness. Preferably, the photochromic material-containing ink is prepared by processes of nano printing, ink-jet printing, silk screen printing, offset printing and the like or by adopting a deposition mode. Preferably, the photochromic layer can be colorless, i.e., transparent in a normal state. During manufacturing, the photochromic gradient color layer is printed on the substrate, namely, the photochromic material is mixed into the transparent imprinting glue, and the photochromic layer with the thickness gradually increasing (thickening) or gradually decreasing (thinning) from one side is imprinted. Compared with the color-changing schemes (such as electrochromism) of other embodiments, the photochromic gradual-changing film of the embodiment has the advantages of simple structure, simple manufacturing process and no need of additional scarce energy, can realize color change and color gradual change (namely, visible light color change and visual effect with color gradual change are realized under the irradiation of light) by utilizing light (such as sunlight and ultraviolet light), and thus, the appearance can be changed on the premise of not changing decoration (film) pieces, and new visual experience and dynamic sense are brought to consumers.

As a variation of the embodiment of fig. 1, as shown in fig. 2, which is a schematic structural diagram of a second example of the photochromic gradient film, the photochromic gradient film 20 has a substrate 21 and a photochromic layer 22, a groove 23 for accommodating a photochromic material is configured in the photochromic layer 22, and the groove 23 is arranged in a gradient manner (for example, by setting one or a combination of parameters of depth, width, duty ratio, and the like of the groove 23). In this embodiment, the base material 21 is a PET film having a thickness of 50 to 200 μm. In other embodiments, other materials as described above may be used for the substrate. Preferably, the width of the groove 23 varies, such as a periodic variation of the width of the groove 23 from 3.5 μm to 2 μm to 0.2 μm. During the preparation, the printing mode of preferred adoption nanometer printing, this photochromism layer contains during the preparation: s1, pressing texture on a transparent substrate 21 by using transparent pressing glue, wherein the texture comprises a plurality of grooves for containing photochromic materials, namely UV pressing texture; s2, filling the photochromic ink into the UV embossed texture. In S1, the transparent imprint adhesive is solvent-free uv-curable acrylic resin, and preferably, in one embodiment, at least one of the width, depth, and duty ratio of the groove is configured to be changed (gradually changed). In one embodiment, the width of the grooves varies from 5.5 μm to 3.5 μm to 0.5 μm, wherein the network of grooves on the surface of the transparent imprint gel is in a linear array (and in other embodiments is not limited to a linear array). S2, the photochromic ink is a transparent ink containing resin, curing agent, diluent, leveling agent, etc. and is prepared by adding resin, curing agent, diluent, leveling agent, etc. to the solution or dispersion of photochromic material. And after the photochromic ink is filled in the transparent impression glue, the photochromic ink is uniformly filled at the bottom of the groove of the transparent impression glue.

In one embodiment, the photochromic layer may be formed by screen printing, offset printing, or the like. In the production of the photochromic layer, the photochromic layer is disposed on the transparent substrate by printing using screen printing or offset printing. Wherein the substrate can be a PET film with a thickness of 50-200 μm. The photochromic ink is gradually distributed on the surface of the base material, and the thickness of the photochromic ink is 3-5 mu m.

In one embodiment, the photochromic layer is formed by ink-jet printing, and the ink-jet printing is performed on the base material by changing a single color or two-color hue at the time of forming the photochromic layer. The base material is a PET film with a thickness of 50-200 μm. The photochromic ink is gradually distributed on the surface of the base material, and the thickness of the photochromic ink is 0-5 mu m. The single color ink-jet printing (as shown in fig. 1) refers to that photochromic ink with a single color is sprayed on a substrate after color concentration is adjusted, the two-color ink-jet printing refers to that photochromic ink with two colors (two different colors) is sprayed on the substrate after color concentration is adjusted by mixing and is sprayed on the substrate or the photochromic ink with two laminated hues is sprayed on the substrate, and the colors of the photochromic ink comprise red, yellow, blue and purple phases.

The single-layer photochromic structure adopted in the photochromic gradient film of the above embodiment is further optimized by the inventor, that is, a color gradient layer (for example, a color gradient modification layer or an ultraviolet-resistant gradient color layer, referred to as a gradient color layer for short) is added, and the color gradient layer is combined with the photochromic layer to achieve a better visual effect of photochromic gradient. Preferably, the method adopts a laminated structure, so that the requirement on the photochromic material can be reduced. Provides the straight-line rate for manufacturing the photochromic gradient film.

Referring to fig. 3, a schematic structural diagram of a third embodiment of a photochromic gradient film is shown, the photochromic gradient film 30 includes a substrate 31, a first photochromic layer 31, and a second photochromic layer 32. After the two-layer photochromic structure is discolored, the combination of 2 lights with the same color or different colors (influenced by the thickness) enables the whole photochromic gradual-changing film to show gradual change.

Fig. 4 shows a variation of the embodiment of fig. 3, which is a schematic structural diagram of a photochromic gradient film according to a fourth embodiment of the present application, the photochromic gradient film 40 includes a substrate 41, a common gradient color layer 42, and a photochromic layer 43, wherein the photochromic layer 43 is laminated on the common gradient color layer 42. In one embodiment, the positions of the ordinary gradient color layer 42 and the photochromic layer 43 are interchanged. In one embodiment, the common gradient color layer 42 may also be a first photochromic layer and a photochromic layer 43 (a second photochromic layer).

Fig. 5 is a schematic structural diagram of a fifth embodiment of a photochromic gradient film according to the present application. The photochromic gradient film 50 comprises a base material 51, a photochromic layer 52 and a gradient color layer 53, wherein the photochromic layer 52 is laminated on the transparent base material 51, and the gradient color layer 53 is laminated on the photochromic layer. In this embodiment, the gradient color layer 53 is a gradient color layer (in other embodiments, a plurality of gradient color layers) or an ultraviolet-resistant gradient color layer (in other embodiments, a plurality of ultraviolet-resistant gradient color layers). The photochromic layer may be graded or uniform in color. In one embodiment, the photochromic layer 52 and the gradient color layer 53 are disposed on both sides of the substrate 51 (as shown in fig. 6, the photochromic layer 62 and the gradient color layer 63 are disposed on both sides of the substrate 61, and the thickness of the gradient color layer 63 is gradually increased from one side to the other side in the x direction). At this time, the photochromic gradient film is applied to the occasion with light, the light firstly passes through the gradient color layer 53/63 (gradient color film layer or ultraviolet-resistant gradient color layer) and then irradiates on the photochromic layer, and the gradient color layer 53/63 has the characteristic of blocking ultraviolet rays, so that the light intensity received by the photochromic layer 52/62 is gradient, the uniform photochromic layer can also generate gradient color, and the processing technology of the uniform film layer is simpler than that of the gradient ink layer. In other embodiments, the graded color layer 53/63 includes a color film layer with a graded feature, such that the photochromic graded film exhibits a graded feature and has a richer color effect. The gradient color layer 53/63 can be prepared by ink jet printing, offset printing, screen printing.

During the manufacture, the gradual change color nanometer ink layer is printed on the base material, and the printing method comprises the following steps: ink jet, offset, screen printing, etc.; the uniform or graded photochromic layer is then printed by screen printing or offset printing. Wherein, the base material adopts a PET film with the thickness of 50-200 μm. The thickness of the ink layer with gradually changed colors printed by ink-jet printing, offset printing and silk-screen printing is changed, such as 3-2-0.2 μm. The photochromic ink is uniformly distributed on the surface of the color modification ink layer, and the thickness of the photochromic ink is about 8-10 mu m.

In the above embodiment, if the gradation color layer is an ultraviolet blocking gradation color layer, it has a function of gradation of ultraviolet transmittance, and an ultraviolet blocking layer containing an ultraviolet blocking agent, such as TiO2, ZnO, or an ultraviolet absorber, or a vacuum-deposited TiO2 layer, or a known ultraviolet blocking optical film layer by interference, is printed therein. The ultraviolet resistant nano material is a series of ultraviolet resistant agents which have absorption or refraction effects on sunlight and have better transparency after being coated into a film, and can be TiO2, ZnO, ultraviolet absorbers and the like. The wavelength band blocked by ultraviolet rays refers to a wavelength band that can cause the photochromic film to undergo a significant reversible color change within a time range. The thickness of the uvioresistant nano ink layer is periodically changed, for example, the thickness is changed from about 3.5 μm to 2 μm to 0.2 μm. The photochromic layer is uniformly distributed on the surface of the ultraviolet-resistant layer, and the thickness of the photochromic layer is 8-10 mu m.

Fig. 7 is a schematic structural diagram of a photochromic gradient film according to a seventh embodiment of the present application. The photochromic gradient film 70 comprises a substrate 71, a gradient color layer 72 and a photochromic layer 74, wherein the gradient color layer 72 comprises a groove (also called a groove) 73, an oil film forming color is filled in the groove network, the width and the depth of the groove are set according to a certain rule to form the color gradient film layer 72, and the photochromic layer 74 is laminated on the groove. The photochromic layer 74 is of uniform thickness.

As a variation of the embodiment of fig. 7, fig. 8 shows a schematic structural diagram of a photochromic gradient film, which is different in that a gradient color layer and a photochromic layer are located on both sides of a substrate. The photochromic gradient film 80 comprises a substrate 81, a gradient color layer 82 and a photochromic layer 84, wherein the gradient color layer (also called as a texture layer) 82 comprises a groove (also called as a groove and a groove texture) 83 filled with an oil film to form a color, the width and the depth of the groove are set according to a certain rule to form the color gradient film layer 82, and the photochromic layer 84 is arranged on the other side of the substrate 81 opposite to the gradient color layer 82. The photochromic layer 84 is of uniform thickness.

As a variation of the embodiment of fig. 7, a schematic structural diagram of a photochromic gradient film is shown in fig. 9, which is different in that the thickness of the photochromic layer gradually increases or gradually decreases from one side to the other side. The photochromic gradient film 90 includes a substrate 91, a gradient color layer 92, and a photochromic layer 94, wherein the gradient color layer 92 includes a groove (also called a trench) 93 in which an oil film is filled in the trench network to form a color, the width and depth of the trench are set according to a certain rule to form a color gradient film layer 72, and the photochromic layer 92 is stacked thereon. The photochromic layer 94 has a thickness that gradually increases or decreases from side to side (for a description of the thickness, please refer to fig. 6).

As a modification of the embodiment of fig. 7, a schematic structural diagram of a photochromic gradient film is shown in fig. 10, which is different in that a micro-nano structure layer is disposed on the other side of the base material opposite to the gradient color layer, and the optical effect of the photochromic gradient film is improved by such a design. A photochromic gradient film 100, comprising a substrate 101, a gradient color layer 102, and a photochromic layer 104, wherein the gradient color layer 102 comprises a groove (also called a groove or a groove texture) 103 filled with an oil film to form a color, the width and depth of the groove are set according to a certain rule to form the color gradient film 102, and the photochromic layer 104 is stacked thereon (the thickness of the photochromic layer 104 may be the same or gradually increases/decreases from one side to the other side, the description of the thickness refers to fig. 6); a micro-nano structure layer 105 is arranged on the other side of the substrate 101 opposite to the gradient color layer 102. Preferably, the micro-nano structure layer 105 includes a plurality of lenses.

As a modification of the embodiment of fig. 10, a schematic structural view of a photochromic gradient film is shown in fig. 11, which is different in that a reflective layer and/or a colored layer are sequentially laminated on a micro-nano structure layer. A photochromic gradient film 110, comprising a substrate 111, a gradient color layer 112, and a photochromic layer 114, wherein the gradient color layer 112 comprises a groove (also called a groove or a groove texture) 113 filled with an oil film to form a color, the width and depth of the groove are configured in a gradient manner or set according to a certain rule to form the color gradient film 112, and the photochromic layer 114 is stacked thereon (the thickness of the photochromic layer 1104 can be uniform or gradually increased/decreased from one side to the other side); a micro-nano structure layer 115 is disposed on the other side of the substrate 111 facing the gradation layer 112, and a reflective layer 116 and a colored layer 117 are sequentially stacked thereon. The micro-nano structure layer 105 includes a plurality of lenses. The optical effect of the photochromic gradient film is improved through the design.

In this embodiment, the base 71 is a PET film with a thickness of 50 to 200 μm. The photochromic gradient film is prepared by the following steps of,

embossing groove textures 73, namely UV embossing textures, on the transparent substrate 71 by using transparent embossing glue; filling the color nano oil film into the groove network of the UV impressing texture to form a color gradient film, namely manufacturing a color gradient layer; the width, depth or duty ratio of the groove is gradually configured or set according to a certain rule. Followed by printing of the photochromic layer 74. Preferably, the photochromic layer 74 is screen printed. The photochromic layer 74 is uniform in thickness or graded in thickness. In the process of UV impressing the texture, the transparent impressing glue adopts solvent-free ultraviolet curing acrylic resin, the thickness is 5.5-3.5-0.5 μm, and the groove network on the surface of the transparent impressing glue is preferably a linear array. In the process of printing the color nano ink, the color nano ink is uniformly filled at the bottom of the groove of the transparent impression glue after being filled into the transparent impression glue and is communicated with the groove, and the thickness of the color nano ink layer is about 3.5-2-0.2 μm. The photochromic ink is uniformly distributed on the surface of the color modification ink layer, and the thickness of the photochromic ink is 8-10 mu m.

The application provides a preparation method of the photochromic gradient film, which comprises the following steps:

s11, forming a gradient color layer on one side of a base material;

s12, forming a photochromic layer on the other side of the base material or the gradient color layer; or the like, or, alternatively,

s11, forming a photochromic layer on one side of a base material;

and S12, forming a gradient color layer on the other side of the base material or on the photochromic layer. The gradient color layer visually presents a color gradient obtained by a thickness gradient (e.g., gradually increasing or gradually decreasing from one side to the other) of the gradient color layer or by a gradient arrangement of the grooves configured therein in width, depth and/or duty cycle.

In one embodiment, the photochromic gradient film further comprises a protective layer, which is stacked on the photochromic layer or on one side of the substrate or on the color gradient layer, and has a protective effect to prolong the service life of the film.

The photochromic gradual-change film in the embodiment can be used as a decorative film and used for shells of household appliances, various intelligent terminals and electronic products.

In the design of the photochromic gradual change film of the embodiment, the photochromic gradual change film comprises the base material and the photochromic layer, the photochromic layer changes color under the irradiation of light (such as sunlight) and has a gradual change effect, so that the appearance can be visually changed on the premise of not changing the decorative part, and various visual new experiences and dynamic effects are brought to consumers.

In the design of the substrate, a transparent substrate, such as one selected from glass, quartz, transparent plastic substrate, ceramic, etc., or one or a combination of PET film, transparent PI film, PEN film, nano cellulose paper, or explosion-proof film, etc., can be used.

In the design of the photochromic layer, which comprises a photochromic material, the photochromic layer exhibits a color gradient characteristic in at least one color change state. The thickness of the photochromic layer may be gradually increased (thickened)/decreased (thinned) from one side to the other side, so that the photochromic layer is subjected to photochromism under the irradiation of light, and the color of the photochromic layer is characterized by gradual change due to the film thickness. Preferably, the photochromic material-containing ink is prepared by processes of nano printing, ink-jet printing, silk screen printing, offset printing and the like or by adopting a deposition mode. Preferably, the photochromic layer can be colorless, i.e., transparent in a normal state. Compared with other color-changing schemes (such as electrochromism), the photochromic gradient film has the characteristics of simple structure and no need of adding a scarce energy source during manufacturing, and can be realized by light (such as sunlight and ultraviolet light) during utilization.

In the design of the photochromic layer, a groove is arranged in the photochromic layer, the photochromic material is filled in the groove, and the characteristic of photochromic color gradual change is realized through the gradual change setting of parameters such as the depth, the width, the duty ratio and the like of the groove. The photochromic material is colorless or colored photochromic ink which comprises red, yellow, blue and purple phases.

In the design of the photochromic layer, it may comprise a gradient color layer, the photochromic layer realizing the characteristic of photochromic color gradient through the combination thereof.

In the design of the photochromic layer, the film thickness thereof may be gradually increased/decreased from one side to the other side, achieving the characteristic of color gradation. The photochromic layer is matched with the photochromic layer to realize the characteristic of photochromic gradual change.

In the design of the photochromic layer, a groove is arranged in the photochromic layer, pigment is filled in the groove, and the characteristic of color gradual change (sometimes called as a texture layer) is realized by the gradual change of parameters such as the depth, the width, the duty ratio and the like of the groove, and the characteristic of photochromic color gradual change is realized by the cooperation of the groove and the photochromic layer.

In the design of the gradient color layer, it can be a layer of gradient color film or an uvioresistant gradient color layer. The photochromic layer is graded or uniform in color. The photochromic layer and the gradient color layer can be arranged on the same side of the substrate or arranged on two sides of the substrate. Preferably, the light passes through the gradient color layer before being irradiated on the photochromic layer when being disposed on both sides of the substrate.

It should be noted that in other embodiments, for the same photochromic gradient film, one or more of the features of "substrate", "photochromic layer", "gradient layer", "texture layer", "micro-nano structure layer" and the like may be included. That is, the above features can be arbitrarily arranged and combined and used for improvement of the photochromic gradient film.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A photochromic gradient film is characterized by comprising

A base material, a photochromic layer,

2. The photochromic gradient film of claim 1 wherein,

the thickness of the photochromic layer is gradually increased or decreased from one side to the other side, and the photochromic layer contains photochromic materials and shows color gradual change in a photochromic state.

3. The photochromic gradient film of claim 1 wherein,

the photochromic layer has uniform thickness and is provided with a plurality of grooves,

the groove is filled with photochromic materials, and the photochromic gradual-changing film presents color gradual change in a color-changing state through one or the combination of the depth, the width and the duty ratio of the groove which is gradually changed.

4. The photochromic gradient film of claim 1 wherein the substrate is selected from one or a combination of glass, quartz, transparent plastic substrate, ceramic substrate, PET film, transparent PI film, PEN film, nano cellulose paper, explosion-proof film.

5. The photochromic gradient film of claim 1, wherein the photochromic layer comprises 2 or more photochromic materials, and the color gradient is represented by a superposition combination of colors in a photochromic state.

6. The photochromic gradient film of claim 1, wherein the photochromic layer further comprises a gradient color layer,

the thickness of the gradient color layer is gradually increased or gradually decreased from one side to the other side, or

The thickness of the gradient color layer is consistent, a plurality of grooves are arranged in the gradient color layer in a gradient way, pigments are filled in the grooves,

7. The photochromic gradient film of claim 6 wherein,

the photochromic layer has a thickness gradually increasing or decreasing from one side to the other, or

The photochromic layer is consistent in thickness, and color gradual change is realized through the combination of the gradual change color layer and the photochromic layer in a color changing state.

8. The photochromic gradient film of claim 6 wherein the gradient color layer comprises at least one layer of a gradient color film or at least one ultraviolet resistant gradient color layer.

9. The photochromic gradient film according to claim 6, 7 or 8, wherein the gradient color layer and the photochromic layer are disposed on the same side of the substrate, or the gradient color layer and the photochromic layer are disposed on both sides of the substrate.

10. The photochromic gradient film according to claim 6, 7 or 8, further comprising a micro-nano structure layer disposed on one side of the substrate, wherein the micro-nano structure layer comprises a plurality of micro-nano structures arranged in a convex and/or concave manner.

11. The photochromic gradient film of claim 10, further comprising a reflective layer and/or a colored layer laminated on the micro-nanostructure layer.

12. The photochromic gradient film of claim 1 wherein the photochromic material is a colorless or colored photochromic ink.

13. The photochromic gradient film of claim 12 wherein the photochromic ink comprises red, yellow, blue, violet phases.

14. A method for preparing a photochromic gradient film is characterized by comprising

A photochromic layer is arranged on one side of the substrate, i.e. the photochromic material is formed into a photochromic layer with gradually increasing or decreasing thickness from one side by ink-jet printing, screen printing or offset printing, or

And (3) stamping a texture on the substrate by using a transparent stamping glue, wherein the texture comprises grooves with gradually changed depths and/or widths and/or duty ratios, and filling photochromic ink into the grooves.

15. The method of claim 14, wherein another photochromic layer is formed on the other side of the substrate or on the photochromic layer.

16. The method according to claim 14, wherein the step of preparing the composition,

the thickness of the groove is changed from 5.5 mu m to 3.5 mu m to 0.5 mu m, and the thickness of the photochromic material in the groove is changed from 3.5 mu m to 2 mu m to 0.2 mu m.

17. A preparation method of a photochromic gradient film is characterized by comprising the following steps:

s11, forming a gradient color layer on one side of a base material;

s12, forming a photochromic layer on the other side of the base material or the gradient color layer;

or the like, or, alternatively,

s11, forming a photochromic layer on one side of a base material;

18. The method according to claim 17, wherein the step of preparing the composition,

the photochromic layer has a uniform or graded thickness.

19. The method according to claim 17, wherein the step of preparing the composition,

the gradient color layer and the photochromic layer are respectively formed by nano-imprinting, ink-jet printing, silk-screen printing, offset printing or coating process.