Liquid crystal film with intelligent information encryption function and its preparation method and application

Abstract

The present application relates to the technical field of functional liquid crystal materials, and discloses a liquid crystal film with intelligent information encryption function, its preparation method, and application. The liquid crystal film includes two parallel transparent substrates and a composite functional layer between the transparent substrates; the composite functional layer includes a honeycomb polymer matrix and liquid crystals filled in the pores of the polymer matrix, and the liquid crystal has a polymer network; the distribution density of the polymer network in different regions of the liquid crystal film is different, thereby making the liquid crystal film have a reversible information pattern that disappears (or appears) when the power is turned on and appears (or disappears) after the power is turned off; or a reversible information pattern that disappears (or appears) at low temperatures and appears (or disappears) at high temperatures. The distribution density of the polymer network in different regions of the liquid crystal film is different, and it has multiple responses such as electric field, temperature, and magnetic field, which can realize the visual effect of information pattern changing from nothing to something, from something to nothing, or color change, thereby having intelligent information encryption function.

Description

Technical Field

[0001] The present application relates to the technical field of functional liquid crystal materials, and in particular to a liquid crystal film with intelligent information encryption function, a preparation method thereof, and applications thereof. Background Art

[0002] At present, information patterning and controllable materials are usually realized using thermochromic, photochromic, electrochromic and other materials. Commonly used thermochromic materials include inorganic materials such as iodides, complexes, organometallic compounds, and organic materials such as spiropyran, fluorescent derivatives, and polythiophene; photochromic materials include inorganic materials such as WO3, silver chloride, and silver bromide, as well as organic materials such as spiropyran, fulgide, diarylethenes, spirooxazines, and azobenzenes; electrochromic materials include metal oxides or hydrates such as WO3, MoO3, V2O5, Nb2O5, and TiO2, and platinum group (such as Pt, Ir, Os, Pd, Rh, and Ru) metal oxides or hydrates such as NiO, IrO x , Rh2O3, as well as organic compounds such as polythiophenes and their derivatives, viologens, tetrathiafulvalene, metallophthalocyanines, polyaniline, polypyrrole, and polyethylenedioxythiophene. These materials can achieve reversible information patterning under the influence of an external field. However, these color-changing materials suffer from limited functionality and complex processing for flexible thin films.

[0003] Because liquid crystals are responsive to external fields such as electric and magnetic fields, heat, pressure, and humidity, they are an important class of organic thermochromic, photochromic, and electrochromic materials. Among thermochromic liquid crystals, temperature-sensitive color-changing devices, such as thin-film thermometers, have been widely used, utilizing the smectic or crystalline-cholesteric phase transitions of small-molecule and polymeric liquid crystals and the selective reflection properties of cholesteric liquid crystals to incident light. Among photochromic liquid crystals, a series of photochromic materials have been developed by incorporating azobenzene, molecular motors, and molecular switches into small-molecule and polymeric liquid crystals. Among electrochromic liquid crystals, small-molecule liquid crystals, polymer-dispersed liquid crystals, and polymer-stabilized liquid crystals all offer excellent electrochromic properties. All of these liquid crystal materials can achieve reversible information patterning under the influence of an external field.

[0004] However, there are some shortcomings that are difficult to overcome when using the above-mentioned liquid crystal materials to prepare information patterned controllable devices. Among them, small molecule liquid crystals are liquid, making it difficult to prepare large-area flexible films; while polymer liquid crystals have high viscosity, making it difficult to uniformly orient over a large area, making it difficult to process into large-area flexible films, and it is also difficult to switch patterns under the action of an external field. Polymer-stabilized liquid crystal (PSLC) films can achieve various patterns, but due to their low polymer network content, usually less than 10wt%, the peel strength between the two substrates is low, making it difficult to prepare large-area flexible films. Polymer-dispersed liquid crystals (PDLC) have a high polymer matrix content and high peel strength between the two substrates, making it possible to prepare large-area flexible films and have been widely used. However, the porous polymer matrix inside the PDLC cannot provide induction or stabilization for the orientation of the liquid crystal molecules, so its light control characteristics are single, and the film is normally in a light scattering state, making it impossible to achieve multiple patterns.

[0005] Existing reversible information patterned products can no longer meet diverse consumer needs, and there is an urgent need to develop new information patterned and controllable products. Summary of the Invention

[0006] The present application provides a liquid crystal film with intelligent information encryption function and its preparation method and application, aiming to solve the problems of existing liquid crystal information patterning controllable materials such as difficulty in film preparation, difficulty in pattern switching, and inability to achieve multiple patterning.

[0007] In order to achieve the above objectives, this application adopts the following technical solutions.

[0008] In the first aspect of the present application, a liquid crystal film with an intelligent information encryption function is provided, comprising two parallel transparent substrates and a composite functional layer between the transparent substrates; the composite functional layer comprises a honeycomb polymer matrix and liquid crystals filled in the pores of the polymer matrix, the liquid crystals having a polymer network; the distribution density of the polymer network in different regions of the liquid crystal film is different, thereby enabling the liquid crystal film to have a reversibly changing information pattern that disappears (or appears) when an electric field is applied and appears (or disappears) after the electric field is removed; or a reversibly changing information pattern that disappears (or appears) at low temperatures and appears (or disappears) at high temperatures.

[0009] In some embodiments, the raw materials of the composite functional layer include, by weight percentage, 5 to 60 wt% of flexible polymerizable monomers, 0.5 wt% to 15 wt% of rod-shaped photopolymerizable monomers, 20 wt% to 94.4 wt% of liquid crystals, 0.1 wt% to 5 wt% of initiators, and 0.1 to 2 wt% of spacer particles based on the sum of the amounts of flexible polymerizable monomers, rod-shaped photopolymerizable monomers, liquid crystal mixture, and initiator.

[0010] In some embodiments, the flexible polymerizable monomer includes at least one of a flexible photopolymerizable monomer or a flexible thermal polymerizable monomer; wherein the flexible photopolymerizable monomer can undergo free radical polymerization or cationic polymerization under ultraviolet light irradiation; and the flexible thermal polymerizable monomer can undergo thermal polymerization under heating conditions;

[0011] The rod-shaped photopolymerizable monomer can undergo free radical polymerization or cationic polymerization under ultraviolet light irradiation;

[0012] The liquid crystal is a positive liquid crystal, a negative liquid crystal or a dual-frequency driven liquid crystal;

[0013] The initiator is a free radical initiator, a cationic photoinitiator or a thermal initiator;

[0014] The spacer particles are styrene or silicon dioxide microspheres, and the diameter thereof is 2 microns to 100 microns.

[0015] In some embodiments, the flexible photopolymerizable monomer includes at least one of an acrylate monomer, an olefin monomer, a vinyl ether monomer, or an epoxy monomer;

[0016] The flexible thermal polymerizable monomer includes at least one of a mixture of epoxy monomers and thiol monomers, a mixture of epoxy monomers and amino monomers, a mixture of vinyl ether monomers and thiol monomers, a mixture of vinyl monomers and thiol monomers, or a mixture of a monomer containing an amino group, a hydroxyl group, a carboxyl group or a mercapto group and an isocyanate monomer;

[0017] The positive liquid crystal, negative liquid crystal and dual-frequency driven liquid crystal all include nematic liquid crystal, smectic liquid crystal, cholesteric liquid crystal, liquid crystal with smectic A phase-nematic phase transition or liquid crystal with smectic A phase-cholesteric phase transition;

[0018] Wherein, the cholesteric liquid crystal is prepared by cholesterol compounds, liquid crystal containing cholesterol compounds or nematic liquid crystal and chiral compounds; the liquid crystal with smectic A phase-cholesteric phase transition is prepared by cholesterol compounds, liquid crystal containing cholesterol compounds, or liquid crystal with smectic A phase-nematic phase transition and chiral compounds; the chiral molecule is S811, R811, S1011, R1011 or CB15;

[0019] The initiator includes at least one of benzoin ethyl ether, benzophenone, thioanthrone, benzil dimethyl ketal, 2-hydroxy-2-methyl-1-phenylacetone, trimethylbenzoyldiphenylphosphine oxide, benzoin diethyl ether diazonium salt, diaryl iodonium salt, triaryl sulfonium salt, alkyl sulfonium salt, iron arene salt, sulfonyloxy ketone, triaryl siloxy ether, amine curing agent, dibutyl tin, tributyl tin or organic lead compound.

[0020] In some embodiments, the rod-shaped photopolymerizable monomer has a structure or a combination thereof represented by any one of formulas (1) to (8):

[0021]

[0022] Wherein, m is 1 to 20; n is 1 to 20; x is 1 to 2; y is 1 to 2;

[0023] E and Q are acrylate, epoxy, vinyl ether or olefin functional groups.

[0024] In some embodiments, the raw material of the composite functional layer further includes a dye; the dye is an azo dye, an anthraquinone dye or a phthalocyanine dye.

[0025] A second aspect of the present application provides a method for preparing the liquid crystal film having the intelligent information encryption function, comprising:

[0026] S1, mixing the raw materials uniformly, adding the mixture between the substrates until the space between the substrates is filled, and performing a first curing by ultraviolet light polymerization and / or thermal polymerization to obtain a film A;

[0027] S2, under the condition that the liquid crystal material molecules in the film A are oriented or not oriented, irradiating the film A with ultraviolet light through a photomask at a temperature T1 for a time t1, performing a second curing, thereby obtaining a film B;

[0028] S3, under the condition that the liquid crystal material molecules in the film B are oriented or not oriented, the film B is irradiated with ultraviolet light for t2 time at temperature T2 to perform a third curing to obtain a liquid crystal film with intelligent information encryption function.

[0029] In some embodiments, when the flexible polymerizable monomer is a flexible photopolymerizable monomer, the preparation method includes:

[0030] The raw materials are mixed uniformly to form a precursor solution, and the precursor solution is added between the substrates until the space between the substrates is filled. Under the condition of orienting or not orienting the liquid crystal material molecules in the precursor solution, ultraviolet light is irradiated to the precursor solution through a photomask at a temperature T1 for a time t1 to perform a first curing to obtain a film A;

[0031] Under the condition that the liquid crystal material molecules in the film A are oriented or not oriented, the film A is irradiated with ultraviolet light for t2 time at temperature T2 for a second curing to obtain a liquid crystal film with intelligent information encryption function.

[0032] In some embodiments, the orientation is specifically: controlling the molecular orientation by applying an electric field to film A or film B;

[0033] and / or,

[0034] In S1, when the flexible polymerizable monomer is a flexible photopolymerizable monomer, ultraviolet light irradiation polymerization is adopted, the temperature is -20 to 60°C, the time is 5 to 90 seconds, and the ultraviolet light intensity is 0.5 to 300 mW / cm 2 When the flexible polymerizable monomer is a flexible thermal polymerizable monomer, thermal polymerization is adopted, the temperature is 20 to 120° C., and the time is 0.1 to 1 hour; when the flexible polymerizable monomer is a blend of a flexible photopolymerizable monomer and a flexible thermal polymerizable monomer, the flexible polymerizable monomer can be polymerized by ultraviolet radiation and thermal polymerization in steps;

[0035] and / or,

[0036] T1 is -20~60℃; t1 is 1~600s, and UV intensity is 0.5~300mW / cm 2 ;

[0037] and / or,

[0038] T2 is -20~60℃, t2 is 5~300s, and UV intensity is 0.5~300mW / cm 2 .

[0039] The third aspect of the present application provides the application of the above-mentioned liquid crystal film with intelligent information encryption function or the liquid crystal film with intelligent information encryption function prepared by the above-mentioned preparation method in a patterned controllable device.

[0040] Compared with the prior art, the present invention has the following advantages:

[0041] The liquid crystal film with intelligent information encryption function of the present application has different distribution densities of polymer networks in different regions and has multiple responses such as electric field, temperature and magnetic field. It can realize rich information pattern customization and can achieve various visual effects such as information pattern from nothing to something, from something to nothing or color change, thereby having information encryption function.

[0042] The preparation method of the present application achieves the precise construction of patterned network structures during the polymerization process by regulating the polymerization rate, diffusion rate and phase separation process. It can prepare customized films with different patterns and is easy to process on a large area, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] To more clearly illustrate the technical solutions of the embodiments of this application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some of the embodiments described in this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0044] Figure 1Detailed illustrations of two masks used in the embodiments of this application;

[0045] FIG2 is a diagram showing the preparation process and working principle of the liquid crystal film of the present application; Figure 2a The following is a diagram showing the preparation process and working principle of a liquid crystal film with electrically controlled reversible information patterning function; Figure 2b The following is a diagram showing the preparation process and working principle of a liquid crystal film with temperature-controlled reversible information patterning function;

[0046] Figure 3 This is a physical picture of the liquid crystal film with the electrically controlled reversible information encryption function of Example 1;

[0047] Figure 4 A physical picture of the liquid crystal film with the electrically controlled reversible information encryption function according to Examples 2 and 3;

[0048] Figure 5 This is a physical picture of the liquid crystal film with temperature-controlled reversible information encryption function of Example 4;

[0049] Figure 6 This is a physical picture of the liquid crystal film with temperature-controlled reversible information encryption function of Example 5;

[0050] Figure 7 This is a physical picture of the liquid crystal film with electrically controlled reversible information encryption function of Example 6. DETAILED DESCRIPTION

[0051] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0052] In the following description of this embodiment, the terms "include", "comprising", "having" and "containing" are open-ended terms, meaning including but not limited to.

[0053] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, B exists alone, and both A and B exist. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0054] In the following description of this embodiment, the term "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0055] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0056] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0057] It will be understood by those skilled in the art that the numerical ranges in the examples of the present application are to be understood as specifically disclosing each intermediate value between the upper and lower limits of the range. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also included in the present application. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0058] Unless otherwise indicated, the technical / scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which this application belongs. Although this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of this application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of any conflict with any incorporated document, the content of this specification shall prevail.

[0059] In the first aspect, the present application provides a liquid crystal film with an intelligent information encryption function, comprising two parallel transparent substrates and a composite functional layer between the transparent substrates; the composite functional layer comprises a honeycomb polymer matrix and a liquid crystal mixture filled in the pores of the polymer matrix, the liquid crystal mixture having a polymer network; the distribution density of the polymer network in different regions of the liquid crystal film is different, thereby enabling the liquid crystal film to have a reversibly changing information pattern that disappears (or appears) when an electric field is applied and appears (or disappears) after the electric field is removed; or a reversibly changing information pattern that disappears (or appears) at low temperatures and appears (or disappears) at high temperatures.

[0060] Specifically, due to the different orientations of liquid crystal molecules in different regions, or the same orientation of liquid crystal molecules but different anchoring forces of the polymer network on the liquid crystal molecules, the light transmittance or light scattering intensity in different regions of the liquid crystal film changes to different degrees under the action of an external field (such as an electric field, magnetic field or temperature), resulting in the appearance or disappearance of the information pattern; after the external field is removed, the liquid crystal film returns to its initial state.

[0061] In the present application, the transparent substrate is a glass substrate, a PET substrate, or a glass substrate / PET substrate with a transparent indium tin oxide (ITO) conductive coating.

[0062] In this application, the composite functional layer between the two substrates comprises a polymer matrix with a porous honeycomb structure, with liquid crystals filling the pores of the polymer matrix. The liquid crystals comprise a polymer network, and the polymer network fibers can be arranged in either a non-oriented or oriented manner, such as vertical, parallel, or helical. It should be noted that the density of the polymer network varies in different regions of the liquid crystal film.

[0063] The liquid crystal film of the present application can present a pattern change process from nothing to something or from something to nothing under the action of an electric field. For example, when the liquid crystal uses a positive cholesteric phase liquid crystal and the polymer network is vertically oriented, in the area of ​​the liquid crystal film with high polymer fiber density, the liquid crystal molecules are anchored by the anchoring force of the polymer network and are transparent or translucent; in the area of ​​the liquid crystal film with low polymer fiber density, the liquid crystal molecules are oriented in a focal conic state under the action of the polymer network and are in a light scattering state. When the light scattering state area on the liquid crystal film is small and the transparent or translucent state area is large, a light scattering pattern is presented on a transparent or translucent background; and when the transparent or translucent state area of ​​the liquid crystal film is small and the light scattering state area is large, a transparent or translucent pattern is presented on a light scattering background. When the liquid crystal film is energized, the liquid crystal in the area with low polymer fiber density is vertically oriented and becomes transparent, the light scattering area disappears, the film as a whole becomes transparent, and the information pattern disappears; when the power is turned off, the liquid crystal molecules in the area with low polymer fiber density are oriented in a focal conic state and become light scattering, and the information pattern reappears; the liquid crystal film thus realizes the reversible patterning function.

[0064] For example, when negative liquid crystal is used or dual-frequency driven liquid crystal is used, the liquid crystal film can realize a reversible information patterning function in which a pattern is displayed when an electric field is applied and the pattern disappears when the electric field is removed.

[0065] In this application, when the liquid crystal is a smectic A-cholesteric phase transition liquid crystal (SmA-LC) and the polymer network is vertically oriented, the liquid crystal film exhibits a pattern change process from non-existent to present as the temperature changes. For example, when a liquid crystal is selected in which the polymer network is vertically oriented and exhibits a smectic A phase at low temperatures and a cholesteric phase at high temperatures, the smectic A phase liquid crystal molecules are vertically oriented at low temperatures, and the liquid crystal film is transparent. When the liquid crystal film is heated to the cholesteric phase, in areas with high polymer fiber density, the liquid crystal molecules are anchored by the anchoring force of the polymer network, and the liquid crystal molecules remain vertically oriented, and the film is transparent in these areas. However, in areas with low polymer fiber density, the polymer network anchors the liquid crystal molecules less strongly, and the cholesteric phase liquid crystal molecules exhibit a focal conic molecular orientation, and the film exhibits a light-scattering state in these areas. Depending on the size of the mask, as the temperature increases, a light-scattering pattern can be displayed on a transparent background, or a transparent information pattern can be displayed on a light-scattering background, realizing the information pattern from non-existent to present. As the temperature decreases, the information pattern disappears. Thus, as the temperature changes, the film exhibits a reversible change from non-existent to present information pattern.

[0066] In the present application, when the liquid crystal is selected to have a smectic A-cholesteric phase transition liquid crystal, the polymer network in a part of the film is vertically oriented, and the polymer network fiber density is relatively low. This part of the film is transparent at low temperatures and is in a light-scattering state at high temperatures. The polymer network in another part of the film is randomly oriented (no orientation), and this part of the liquid crystal has a focal conic molecular orientation and is anchored by the polymer network. The film is in a light-scattering state at both high and low temperatures. Depending on the size of the mask, a light-scattering information pattern can be presented on a transparent background, or a transparent information pattern can be presented on a light-scattering background. As the temperature rises, the transparent part becomes light-scattering, and the pattern disappears, presenting a process of information pattern changing from presence to absence.

[0067] As a preferred embodiment of the present invention, the composite functional layer may further include a dye, such as an azo dye, anthraquinone dye, or phthalocyanine dye. In this case, the liquid crystal film can exhibit different colors. When the power is on / off or when the temperature is high / low, the color of different regions of the liquid crystal film changes, giving the liquid crystal film a color reversible patterning function.

[0068] In the present application, the raw materials of the composite functional layer include, by weight percentage, 5 to 60 wt% of a flexible polymerizable monomer, 0.5 to 15 wt% of a rod-shaped photopolymerizable monomer, 20 to 94.4 wt% of a liquid crystal mixture, 0.1 to 5 wt% of an initiator, and 0.1 to 2 wt% of spacer particles based on the combined amount of the flexible polymerizable monomer, rod-shaped photopolymerizable monomer, liquid crystal, and initiator. In the present application, the spacer particles are preferably polystyrene microspheres.

[0069] In the present application, the flexible polymerizable monomer includes at least one of a flexible photopolymerizable monomer or a flexible thermal polymerizable monomer. The flexible photopolymerizable monomer can undergo free radical polymerization or cationic polymerization under ultraviolet light irradiation, and includes at least one of an acrylate monomer, an olefin monomer, a vinyl ether monomer, or an epoxy monomer. The flexible thermal polymerizable monomer can undergo thermal polymerization under heating conditions, and includes at least one of a mixture of an epoxy monomer and a thiol monomer, a mixture of an epoxy monomer and an amino monomer, a mixture of a vinyl ether monomer and a thiol monomer, a mixture of a vinyl monomer and a thiol monomer, or a mixture of a monomer containing an amino group, a hydroxyl group, a carboxyl group, or a mercapto group and an isocyanate monomer.

[0070] The flexible polymerizable monomer is preferably hydroxypropyl methacrylate (HPMA), lauryl methacrylate (LMA), polyethylene glycol diacrylate (PEGDA600), or bisphenol A ethoxylate dimethacrylate (Bis-EMA15), and more preferably a mixture of HPMA, LMA, PEGDA600, or Bis-EMA15. The chemical formulas of the above four monomers are as follows:

[0071]

[0072] In this application, based on the performance requirements of the final device, the liquid crystal can be selected from positive liquid crystal, negative liquid crystal, or dual-frequency driven liquid crystal. The positive liquid crystal, negative liquid crystal, or dual-frequency driven liquid crystal can be selected from nematic liquid crystal, smectic liquid crystal, cholesteric liquid crystal, liquid crystal with smectic A phase-nematic phase transition, or liquid crystal with smectic A phase-cholesteric phase transition, such as positive nematic liquid crystal, negative cholesteric liquid crystal, and the like.

[0073] Among them, the cholesteric liquid crystal of the present application can be prepared using cholesterol compounds, liquid crystals containing cholesterol compounds, or nematic liquid crystals plus chiral compounds; the liquid crystals with smectic A phase-cholesteric phase transition can be prepared using cholesterol compounds, liquid crystals containing cholesterol compounds, or liquid crystals with smectic A phase-nematic phase transition plus chiral compounds.

[0074] Specifically, the chiral molecule can be selected from commercial chiral compounds such as S811, R811, S1011, R1011, or CB15, and its usage is 0.1 to 90 wt % of the mass of the cholesteric liquid crystal or the smectic A phase-cholesteric phase transition liquid crystal, preferably 0.1 to 4 wt %. In the present application, the chiral compound is preferably S811, and its chemical formula is as follows:

[0075]

[0076] The rod-shaped photopolymerizable monomer can undergo free radical polymerization or cationic polymerization under ultraviolet light irradiation, or can undergo free radical polymerization and cationic polymerization under ultraviolet light irradiation; it includes any one or a mixture of several of the structures represented by formula (1) to formula (8):

[0077]

[0078]

[0079] Wherein, m is 1 to 20; n is 1 to 20; x is 1 to 2; y is 1 to 2;

[0080] E and Q are acrylate, epoxy, vinyl ether or olefin functional groups.

[0081] The preferred rod-shaped photopolymerizable monomer in this application is C6M, whose chemical formula is as follows:

[0082]

[0083] In the present application, the initiator may be a free radical initiator, a cationic photoinitiator, or a thermal initiator. The free radical initiator includes at least one of benzoin ethyl ether, benzophenone, thioanthrone, benzyl dimethyl ketal, 2-hydroxy-2-methyl-1-phenylacetone, trimethylbenzoyl, diphenylphosphine oxide, or benzoin diethyl ether; the cationic photoinitiator includes at least one of a diazonium salt, a diaryliodonium salt, a triarylsulfonium salt, an alkylsulfonium salt, an iron arene salt, a sulfonyloxyketone, or a triarylsiloxane; and the thermal initiator includes at least one of an amine curing agent, dibutyltin, tributyltin, or an organic lead compound, wherein the amine curing agent is preferably K-54 or DMP-30.

[0084] In the embodiment of the present application, the photoinitiator is preferably benzil dimethyl ketal, i.e., photoinitiator 651, whose chemical formula is:

[0085]

[0086] In the present application, the spacer particles are preferably polystyrene microspheres.

[0087] In a second aspect, the present application provides a method for preparing the above-mentioned liquid crystal film with intelligent information encryption function, comprising:

[0088] S1, mixing the raw materials uniformly, adding the mixture between the substrates until the space between the substrates is filled, and performing a first curing by ultraviolet light polymerization and / or thermal polymerization to obtain a film A;

[0089] Specifically, under the action of UV radiation and a photoinitiator, the flexible photopolymerizable monomers polymerize and solidify under UV radiation to form a honeycomb-shaped polymer matrix, with liquid crystals filling the pores of the polymer matrix. A small amount of the rod-shaped photopolymerizable monomers polymerize and solidify, while the vast majority are distributed within the liquid crystals. This is because the collision probability between the free radicals of the flexible polymerizable monomers is much greater than that of the rigid rod-shaped photopolymerizable monomers. Therefore, during the first light-curing step, the flexible photopolymerizable monomers are primarily cured within a certain period of time.

[0090] When the flexible polymerizable monomer is a flexible thermal polymerizable monomer, under heating conditions, the flexible thermal polymerizable monomer is cured by thermal polymerization to form a honeycomb-shaped polymer substrate, and the liquid crystal is filled in the pores of the polymer substrate; the rod-shaped photopolymerizable monomer does not undergo polymerization and curing, and is distributed in the liquid crystal.

[0091] When the flexible polymerizable monomer is a flexible photopolymerizable monomer, the temperature of the ultraviolet light irradiation polymerization is -20 to 60°C, the time is 5 to 90 seconds, and the ultraviolet light intensity is 0.5 to 300 mW / cm 2 When the flexible polymerizable monomer is a flexible thermal polymerizable monomer, the thermal polymerization temperature is 20 to 120° C., and the time is 0.1 to 1 hour.

[0092] When the flexible polymerizable monomer is a blend of a flexible photopolymerizable monomer and a flexible thermal polymerizable monomer, the curing of the flexible polymerizable monomer can be carried out in steps of ultraviolet light irradiation polymerization and thermal polymerization.

[0093] S2, aligning or non-aligning the liquid crystal molecules in film A, irradiating film A with ultraviolet light through a mask for time t1 at temperature T1, performing a second curing to obtain film B;

[0094] Specifically, by applying an electric field to film A to control the orientation of liquid crystal molecules, the rod-shaped photopolymerizable monomers can be aligned along the direction of the electric field or aligned together with the liquid crystal molecules as the temperature changes. When film A needs to be oriented, at temperature T1, a mask is placed on film A, and an electric field is applied to cause the rod-shaped photopolymerizable monomers and liquid crystal molecules in film A to form a certain orientation. Ultraviolet light is then irradiated through the mask to cause the photopolymerizable monomers in the light-transmitting area of ​​the mask to undergo a polymerization reaction, completing the second curing. The mask of the present application, the actual material is as follows Figure 1 shown.

[0095] During the second curing, T1 is -20 to 60°C. According to the specific requirements of the custom pattern, t1 is 1 to 600s, and the UV intensity is 0.5 to 300mW / cm 2 .

[0096] S3, applying an electric field to the film B for orientation, or not orientation, irradiating the film B with ultraviolet light for t2 time at temperature T2, and performing a third curing to obtain a liquid crystal film with intelligent information encryption function.

[0097] By applying an electric field to film B to control molecular orientation, the rod-shaped photopolymerizable monomers can be oriented along the direction of the electric field with the liquid crystal molecules or oriented together with the liquid crystal molecules as the temperature changes. When film B needs to be oriented, at temperature T2, an electric field is applied to film B to cause the unpolymerized rod-shaped photopolymerizable monomers and liquid crystal molecules to form a certain orientation. Film B is then irradiated with ultraviolet light to cause the rod-shaped photopolymerizable monomers in the area blocked by the mask during the second curing process to polymerize, completing the third curing. T2 is -20 to 60°C; depending on the specific requirements of the custom pattern, t2 is 5 to 300 seconds, and the UV light intensity is 0.5 to 300 mW / cm 2 .

[0098] Because the remaining rod-shaped photopolymerizable monomer content in the unmasked and masked areas differs after the second photocuring, the polymer network density in the unmasked and masked areas differs after the third photocuring process. This application, through the second and third curing processes, produces polymer networks with a specific orientation and different fiber densities in the unmasked, light-transmitting areas and masked areas of the liquid crystal film.

[0099] When this application utilizes a liquid crystal material with a specific phase transition, in addition to using the aforementioned preparation method to prepare the target film, it is also possible to control the molecular orientation of the liquid crystal and photopolymerizable monomer mixture during the second and third photocuring processes by regulating the temperature T1 of the second and third curing processes, thereby controlling the orientation of the resulting polymer network fibers. Furthermore, the different diffusion rates of the rod-shaped photopolymerizable monomer free radicals at high and low temperatures and in different phases, combined with the use of a mask, can result in different densities of the polymer network fibers in different regions.

[0100] In the liquid crystal film of the present application, the regions with different polymer network fiber densities may have the same or different polymer network orientations.

[0101] In the present application, when the flexible photopolymerizable monomer is a flexible photopolymerizable monomer, since the free radical collision probability of the flexible photopolymerizable monomer is greater than the free radical collision probability of the rod-shaped photopolymerizable monomer, when the two coexist, the polymerization rate of the flexible photopolymerizable monomer is greater than the polymerization rate of the rod-shaped photopolymerizable monomer. Therefore, step S1 and step S2 in the above preparation method can be combined into one step; it can also be prepared by the following method:

[0102] The raw materials are mixed uniformly to form a precursor solution, and the precursor solution is added between the substrates until the space between the substrates is filled. Under the condition of orienting or not orienting the liquid crystal material molecules in the precursor solution, ultraviolet light is irradiated to the precursor solution through a photomask at a temperature T1 for a time t1 to perform a first curing to obtain a film A;

[0103] Under the condition that the liquid crystal material molecules in the film A are oriented or not oriented, the film A is irradiated with ultraviolet light for t2 time at temperature T2 for a second curing to obtain a liquid crystal film with intelligent information encryption function.

[0104] In this case, T1 is -20 to 60°C, T2 is -20 to 60°C, t1 is 1 to 600s, t2 is 5 to 300s, and the UV intensity is 0.5 to 300mW / cm 2 .

[0105] The preparation process and working principle of the liquid crystal film of the present application are shown in FIG2. When the liquid crystal used is a positive cholesteric liquid crystal, the liquid crystal film is a liquid crystal film with an electrically controlled reversible information patterning function, and its preparation process and working principle are shown in FIG2. Figure 2a When no electric field is applied, in areas with low polymer network fiber density, the polymer network has a relatively small anchoring effect on the liquid crystal pairs, the liquid crystal molecules form a random orientation, and the liquid crystal film is in a scattering state; in areas with high polymer network fiber density, the polymer network has a greater anchoring effect on the liquid crystal molecules, the liquid crystal molecules are vertically oriented, and the liquid crystal film is transparent; at this time, a light scattering pattern is displayed on the transparent background, as shown in FIG. Figure 3 By controlling the size of the mask, a transparent pattern can also be displayed on a light-scattering background, such as Figure 4 As shown in Figure 1. When an electric field is applied, the liquid crystals become vertically aligned, the entire liquid crystal film becomes transparent, and the pattern disappears. When the electric field is turned off, the pattern reappears.

[0106] The liquid crystal film of the present application, when the liquid crystal used is a liquid crystal material with a certain phase transition, such as a liquid crystal material with a smectic A-cholesteric phase transition, and the polymer network is vertically oriented, the liquid crystal film is a liquid crystal film with temperature-controlled reversible information patterning function. Its preparation process and working principle are as follows Figure 2b As shown. When the ambient temperature is lower than the phase transition temperature of the liquid crystal, the smectic A liquid crystal molecules are vertically oriented, and the film is transparent as a whole. When the ambient temperature is higher than the phase transition temperature of the liquid crystal, in the area where the polymer network fiber density of the liquid crystal film is relatively small, the anchoring effect of the polymer network on the liquid crystal is relatively small, the liquid crystal undergoes a phase transition, and the film switches to a scattering state; while in the area where the polymer network fiber density of the liquid crystal film is relatively large, the anchoring effect of the polymer network on the liquid crystal molecules is relatively large, and when the liquid crystal is heated to the cholesteric phase, the liquid crystal molecules are still vertically oriented, and the film is still transparent; at this time, a pre-set light scattering pattern appears on the transparent background, as shown Figure 5 By controlling the size of the mask, a transparent pattern can be displayed on a light-scattering background. Figure 6 When the ambient temperature is lower than the transition temperature, the film becomes transparent as a whole and the pattern disappears.

[0107] The liquid crystal film of the present application has an intelligent information encryption function and can be used in information patterning controllable devices. The liquid crystal film displays (or does not display) an information pattern before applying an electric field, disappears (or displays) the information pattern after applying the electric field, and displays (or does not display) the information pattern again after turning off the electric field; or, the liquid crystal film has no (or has) an information pattern when it is lower than the phase transition temperature of the liquid crystal, presents (or does not present) an information pattern when it is higher than the phase transition temperature of the liquid crystal, and disappears (or displays) the information pattern again when the ambient temperature is lower than the phase transition temperature of the liquid crystal. By designing the shape and size of the mask to prepare regions of different shapes and sizes with different light transmittances, the customization of specific information patterns can be achieved on the liquid crystal film, which has broad application prospects in the fields of consumer electronics and information encryption.

[0108] The present application is further described below through examples.

[0109] Example 1

[0110] This embodiment provides a method for preparing a liquid crystal film with an electrically controlled reversible information patterning function. The raw materials and proportions thereof are shown in Table 1:

[0111] Table 1 Raw material ratio of Example 1

[0112]

[0113]

[0114] S1: Mix the raw materials described in Table 1 evenly, sandwich them between two layers of ITO conductive plastic films, and use a light intensity of 10 mW / cm at 15°C. 2 The film was irradiated with ultraviolet light for 20 seconds to initiate polymerization of most of the flexible photopolymerizable monomers, thereby obtaining a film A having a honeycomb polymer matrix;

[0115] S2: Place the customized mask on film A, apply an electric field to film A to transform it into a transparent state, heat film A to 40°C, and use a light intensity of 15mW / cm 2 Film A was irradiated with ultraviolet light for 600s, and a region with a relatively high density of polymer network fibers was formed in the light transmission region of the mask, thereby obtaining film B.

[0116] S3, remove the mask and continue to apply the electric field to keep the film B transparent. 2 The film is irradiated with ultraviolet light for 180 seconds, and regions with relatively low polymer network fiber density are formed outside the regions with relatively high polymer network fiber density, thereby obtaining a liquid crystal film with intelligent information encryption function.

[0117] The mask used in Example 1 is Figure 1The mask on the right is a physical picture of the liquid crystal film with intelligent information encryption function. Figure 3 When no electric field is applied, the Huawei logo appears light-scattering against a transparent background. However, when an electric field is applied, the film becomes transparent and the information pattern disappears.

[0118] Example 2

[0119] This embodiment provides a method for preparing a liquid crystal film with an electrically controlled reversible information patterning function. The raw materials and proportions thereof are shown in Table 1:

[0120] S1: Mix the raw materials described in Table 1 evenly, sandwich them between two layers of ITO conductive plastic films, and use a light intensity of 10 mW / cm at 15°C. 2 The film was irradiated with ultraviolet light for 20 seconds to initiate polymerization of most of the flexible photopolymerizable monomers, thereby obtaining a film A having a honeycomb polymer matrix;

[0121] S2: Place the customized mask on film A, apply an electric field to film A to transform it into a transparent state, heat film A to 40°C, and use a light intensity of 15mW / cm 2 Film A was irradiated with ultraviolet light for 600s, and a region with a relatively high density of polymer network fibers was formed in the light transmission region of the mask, thereby obtaining film B.

[0122] S3, remove the mask and continue to apply the electric field to keep the film B transparent. 2 The film is irradiated with ultraviolet light for 180 seconds, and regions with relatively low polymer network fiber density are formed outside the regions with relatively high polymer network fiber density, thereby obtaining a liquid crystal film with intelligent information encryption function.

[0123] The mask used in Example 2 is Figure 1 The mask on the left shows the actual picture of the liquid crystal film with intelligent information encryption function. Figure 4 When no electric field is applied, the Huawei logo appears transparent against a light-scattering background. When an electric field is applied, the film becomes transparent and the information pattern disappears.

[0124] Example 3

[0125] This embodiment provides a method for preparing a liquid crystal film with an electrically controlled reversible information patterning function. The raw materials and proportions thereof are shown in Table 1:

[0126] S1: Mix the raw materials described in Table 1 evenly, sandwich them between two layers of ITO conductive plastic films, and use a light intensity of 10 mW / cm at 15°C. 2 The film was irradiated with ultraviolet light for 20 seconds to initiate polymerization of most of the flexible photopolymerizable monomers, thereby obtaining a film A having a honeycomb polymer matrix;

[0127] S2: Place the customized mask on film A, apply an electric field to film A to transform the film into a transparent state, heat film A to 15°C, and use a light intensity of 5mW / cm 2 Film A was irradiated with ultraviolet light for 180 seconds, and a region with a relatively low density of polymer network fibers was formed in the light-transmitting region of the mask, thereby obtaining film B.

[0128] S3, remove the mask and continue to apply the electric field to keep the film B transparent. 2 The film is irradiated with ultraviolet light for 600 seconds, and regions with relatively high polymer network fiber density are formed outside the regions with relatively low polymer network fiber density, thereby obtaining a liquid crystal film with intelligent information encryption function.

[0129] The mask used in Example 3 is Figure 1 The mask on the right is a physical picture of the liquid crystal film with intelligent information encryption function. Figure 4 When no electric field is applied, the Huawei logo appears transparent against a light-scattering background. When an electric field is applied, the film becomes transparent and the information pattern disappears.

[0130] Example 4

[0131] This embodiment provides a method for preparing a liquid crystal film with a temperature-controlled reversible patterning function. The raw materials and proportions thereof are shown in Table 2:

[0132] Table 2 Raw material ratio of Example 4

[0133]

[0134] The composition of the smectic-cholesteric phase transition liquid crystal (SmA-ChLC) is as follows:

[0135]

[0136] S1: Mix the raw materials described in Table 2 evenly, sandwich them between two layers of ITO conductive plastic films, and use a light intensity of 10 mW / cm at 15°C. 2 The film was irradiated with ultraviolet light for 20 seconds to initiate polymerization of most of the flexible photopolymerizable monomers, thereby obtaining a film A having a honeycomb polymer matrix;

[0137] S2: Place the customized mask on film A, apply an electric field to film A to transform it into a transparent state, heat film A to 40°C, and use a light intensity of 15mW / cm 2 Film A was irradiated with ultraviolet light for 600s, and a region with a relatively high density of polymer network fibers was formed in the light transmission region of the mask, thereby obtaining film B.

[0138] S3, remove the mask and continue to apply the electric field to keep the film B transparent. 2 The film is irradiated with ultraviolet light for 180 seconds, and regions with relatively low polymer network fiber density are formed outside the regions with relatively high polymer network fiber density, thereby obtaining a liquid crystal film with intelligent information encryption function.

[0139] The mask used in Example 4 is Figure 1 The mask on the right is a physical picture of the liquid crystal film with intelligent information encryption function. Figure 5 At low temperatures, the liquid crystal film is transparent, while at high temperatures, the Huawei logo appears light-scattering against a transparent background.

[0140] Example 5

[0141] This embodiment provides a method for preparing a liquid crystal film with a temperature-controlled reversible patterning function. The raw materials and proportions thereof are shown in Table 2:

[0142] S1: Mix the raw materials described in Table 2 evenly, sandwich them between two layers of ITO conductive plastic films, and use a light intensity of 10 mW / cm at 15°C. 2 The film was irradiated with ultraviolet light for 20 seconds to initiate polymerization of most of the flexible photopolymerizable monomers, thereby obtaining a film A having a honeycomb polymer matrix;

[0143] S2: Place the customized mask on film A, apply an electric field to film A to transform it into a transparent state, heat film A to 40°C, and use a light intensity of 15mW / cm 2 Film A was irradiated with ultraviolet light for 600s, and a region with a relatively high density of polymer network fibers was formed in the light transmission region of the mask, thereby obtaining film B.

[0144] S3, remove the mask and continue to apply the electric field to keep the film B transparent. 2 The film is irradiated with ultraviolet light for 180 seconds, and regions with relatively low polymer network fiber density are formed outside the regions with relatively high polymer network fiber density, thereby obtaining a liquid crystal film with intelligent information encryption function.

[0145] The mask used in Example 5 is Figure 1 The mask on the left shows the actual picture of the liquid crystal film with intelligent information encryption function. Figure 6 At low temperatures, the liquid crystal film is transparent, while at high temperatures, a transparent Huawei logo pattern is displayed against a light-scattering background.

[0146] Example 6

[0147] This embodiment provides a two-step method for preparing a liquid crystal film with an electrically controlled reversible patterning function. The raw materials and proportions are shown in Table 1:

[0148] S1, the raw materials described in Table 1 were mixed evenly and sandwiched between two layers of ITO conductive plastic films; an electric field was applied to the films, and a customized mask was placed on the ITO conductive plastic films. The light intensity was 20 mW / cm at 50 °C. 2 The film was irradiated with ultraviolet light for 600s, and a region with a relatively high density of polymer network fibers was formed in the light transmission region of the mask, thereby obtaining film A;

[0149] S2, remove the mask and continue to apply the electric field to keep the film A transparent. 2 The film is irradiated with ultraviolet light for 180 seconds, and regions with relatively low polymer network fiber density are formed outside the regions with relatively high polymer network fiber density, thereby obtaining a liquid crystal film with intelligent information encryption function.

[0150] The mask used in Example 6 is Figure 1 The mask on the right is a physical picture of the liquid crystal film with intelligent information encryption function. Figure 7 When no electric field is applied, the Huawei logo appears light-scattering against a transparent background. However, when an electric field is applied, the film becomes transparent and the information pattern disappears.

[0151] Although this specification has been used to fully describe the present application using general descriptions and specific embodiments, it is obvious to those skilled in the art that modifications or improvements may be made based on the present application. Therefore, such modifications or improvements made without departing from the spirit of the present application are within the scope of protection claimed in this application.

Claims

1. A liquid crystal film with intelligent information encryption function, characterized in that: The invention comprises two parallel transparent substrates and a composite functional layer between the transparent substrates; the composite functional layer comprises a honeycomb polymer matrix and liquid crystals filled in the pores of the polymer matrix, wherein the liquid crystals have a polymer network; the distribution density of the polymer network varies in different regions of the liquid crystal film, thereby enabling the liquid crystal film to have a reversible information pattern that disappears at low temperatures and is displayed at high temperatures, or is displayed at low temperatures and disappears at high temperatures; The liquid crystal is a positive liquid crystal; The preparation method of the liquid crystal film with intelligent information encryption function includes: S1, mixing the raw materials uniformly, adding the mixture between the substrates until the space between the substrates is filled, and performing a first curing by ultraviolet light polymerization and / or thermal polymerization to obtain a film A; S2, under the condition that the liquid crystal material molecules in the film A are oriented or not oriented, irradiating the film A with ultraviolet light through a photomask at a temperature T1 for a time t1, performing a second curing, thereby obtaining a film B; S3, under the condition that the liquid crystal material molecules in the film B are oriented or not oriented, the film B is irradiated with ultraviolet light for t2 time at temperature T2 to perform a third curing to obtain a liquid crystal film with intelligent information encryption function.

2. The liquid crystal film with intelligent information encryption function according to claim 1, characterized in that: The raw materials of the composite functional layer include 5-60wt% of flexible polymerizable monomer, 0.5wt%~15wt% of rigid rod-shaped photopolymerizable monomer, 20wt%~94.4wt% of liquid crystal, 0.1wt%~5wt% of initiator, and 0.1wt%~2wt% of spacer particles based on the total amount of flexible polymerizable monomer, rod-shaped photopolymerizable monomer, liquid crystal mixture and initiator.

3. The liquid crystal film with intelligent information encryption function according to claim 2, characterized in that: The flexible polymerizable monomer includes at least one of a flexible photopolymerizable monomer and a flexible thermal polymerizable monomer; wherein the flexible photopolymerizable monomer can undergo free radical polymerization or cationic polymerization under ultraviolet light irradiation; and the flexible thermal polymerizable monomer can undergo thermal polymerization under heating conditions; The rod-shaped photopolymerizable monomer can undergo free radical polymerization or cationic polymerization under ultraviolet light irradiation; The positive liquid crystal is a smectic A phase-cholesteric phase transition liquid crystal; The initiator is a free radical initiator, a cationic photoinitiator or a thermal initiator; The spacer particles are styrene or silicon dioxide microspheres, and the diameter thereof is 2 microns to 100 microns.

4. The liquid crystal film with intelligent information encryption function according to claim 3, characterized in that: The flexible photopolymerizable monomer includes at least one of an acrylate monomer, an olefin monomer, a vinyl ether monomer or an epoxy monomer; The flexible thermal polymerizable monomer includes at least one of a mixture of epoxy monomers and thiol monomers, a mixture of epoxy monomers and amino monomers, a mixture of vinyl ether monomers and thiol monomers, a mixture of vinyl monomers and thiol monomers, or a mixture of a monomer containing an amino group, a hydroxyl group, a carboxyl group or a mercapto group and an isocyanate monomer; The smectic A phase-cholesteric phase transition liquid crystal is prepared by cholesterol compounds, liquid crystal containing cholesterol compounds, or smectic A phase-nematic phase transition liquid crystal and a chiral compound; the chiral compound is S811, R811, S1011, R1011 or CB15; The initiator includes at least one of benzoin ethyl ether, benzophenone, thioanthrone, benzil dimethyl ketal, 2-hydroxy-2-methyl-1-phenylacetone, trimethylbenzoyldiphenylphosphine oxide, benzoin diethyl ether diazonium salt, diaryliodonium salt, triarylsulfonium salt, alkylsulfonium salt, iron arene salt, sulfonyloxy ketone, triarylsiloxy ether, amine curing agent, dibutyltin, tributyltin or organic lead compound.

5. The liquid crystal film with intelligent information encryption function according to claim 3, characterized in that: The rod-shaped photopolymerizable monomer has a structure shown in any one of formulas (1) to (8) or a combination thereof: ； ； ； Among them, m is 1~20; n is 1~20; x is 1~2; y is 1~2; E and Q are acrylate, epoxy, vinyl ether or olefin functional groups.

6. The liquid crystal film with intelligent information encryption function according to claim 2, characterized in that: The raw materials of the composite functional layer also include dyes; The dye is an azo dye, an anthraquinone dye or a phthalocyanine dye.

7. The liquid crystal film with intelligent information encryption function according to claim 2, characterized in that: When the flexible polymerizable monomer is a flexible photopolymerizable monomer, the preparation method includes: The raw materials are mixed uniformly to form a precursor solution, and the precursor solution is added between the substrates until the space between the substrates is filled. Under the condition of orienting or not orienting the liquid crystal material molecules in the precursor solution, ultraviolet light is irradiated to the precursor solution through a photomask at a temperature T1 for a time t1 to perform a first curing to obtain a film A; Under the condition that the liquid crystal material molecules in the film A are oriented or not oriented, the film A is irradiated with ultraviolet light for t2 time at temperature T2 for a second curing to obtain a liquid crystal film with intelligent information encryption function.

8. The liquid crystal film with intelligent information encryption function according to claim 7, characterized in that: The orientation is specifically: controlling the molecular orientation by applying an electric field to the film A or the film B; and / or, In S1, when the flexible polymerizable monomer is a flexible photopolymerizable monomer, ultraviolet light irradiation polymerization is performed at a temperature of -20 to 60°C, a time of 5 to 90 seconds, and an ultraviolet light intensity of 0.5 to 300 mW / cm 2 When the flexible polymerizable monomer is a flexible thermal polymerizable monomer, thermal polymerization is adopted, the temperature is 20~120℃, and the time is 0.1~1h; when the flexible polymerizable monomer is a blend of a flexible photopolymerizable monomer and a flexible thermal polymerizable monomer, the flexible polymerizable monomer can be polymerized by ultraviolet radiation and thermal polymerization in steps; and / or, T1 is -20~60℃; t1 is 1~600s, and UV light intensity is 0.5~300mW / cm 2 ; and / or, T2 is -20~60℃, t2 is 5~300s, and UV intensity is 0.5~300mW / cm 2 .

9. Use of the liquid crystal film with intelligent information encryption function according to any one of claims 1 to 8 in a patterned controllable device.

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