Anti-counterfeiting ink as well as preparation method and application thereof

Abstract

The invention relates to anti-counterfeiting ink as well as a preparation method and application thereof. The anti-counterfeiting ink comprises polymer chiral mesoporous microspheres, a fluorescent dye and a polymer solution, the polymer chiral mesoporous microsphere has a photonic forbidden band; the central wavelength of the photonic forbidden band is recorded as x nm, the width of the photonic forbidden band is recorded as y nm, the emission wavelength of the fluorescent dye is recorded as z nm, and | x-z | is smaller than or equal to 0.5 y. The anti-counterfeiting ink provided by the invention has the advantages of convenience in processing and writing and multi-mode anti-counterfeiting and encryption functions of circularly polarized light and multi-mode excitation, can meet the application requirements in the fields of anti-counterfeiting, information encryption and the like, and improves the information security.

Description

Technical Field

[0001] The present invention relates to the field of optical anti-counterfeiting technology, and in particular to an anti-counterfeiting ink and a preparation method and application thereof. Background Art

[0002] Counterfeiting and shoddy products are a problem that cannot be completely eradicated in human society. Anti-counterfeiting technology is widely used in daily life. However, with the advancement of science and technology, the level of counterfeiting is also constantly improving, posing a serious threat to the property safety of the people. Therefore, more advanced anti-counterfeiting technology is becoming more and more important.

[0003] Optical anti-counterfeiting technology is widely favored because of its diverse forms and low cost, such as anti-counterfeiting based on changes in parameters such as luminous intensity, luminous wavelength, and luminous lifetime. Circularly polarized light can increase the security of anti-counterfeiting because it carries additional polarization information. For example, CN101319108A ​​discloses a circularly polarized color-changing anti-counterfeiting ink that does not contain interference pigments and has a light-changing effect and a method for making the same. The ink includes components such as liquid crystal material, resin, filler, and solvent, wherein the liquid crystal material is processed from a cholesteric liquid crystal material, and the cholesteric liquid crystal material includes left-handed and / or right-handed cholesteric liquid crystal material or a mixture or polymer of the cholesteric liquid crystal material; the color of the pattern printed with the ink under circularly polarized light is completely different from the color under natural light or light, and can have a left-handed or right-handed or both left-handed and right-handed polarized light effect, and will also produce a color change effect as the human eye's viewing angle changes, thus having the uniqueness of anti-counterfeiting features.

[0004] However, for the application of circularly polarized materials, people generally hope to obtain a higher circularly polarized luminescence asymmetry factor (g lum ) However, they usually have a higher luminescence asymmetry factor (g lum ) liquid crystal circularly polarized luminescent materials must be confined in a rigid liquid crystal box to show their high asymmetry factor. Encapsulation of liquid crystal materials can solve this problem well. The rigid polymer shell can overcome the fluidity of the liquid crystal, and the chiral mesoporous polymer photonic microspheres of the liquid crystal template can overcome the influence of the strong polar environment of the liquid crystal on the luminescence performance of the fluorescent dye. The microspheres are easy to disperse in the aqueous phase and have good solution processing performance. They have unique advantages in preparing easy-to-write anti-counterfeiting inks. However, how to improve the circularly polarized luminescence asymmetry factor (g lum ) to expand the information encryption capability based on the specific rules of circular polarization dichroism is still a key issue that needs to be solved in the anti-counterfeiting field.

[0005] Therefore, there is an urgent need in this field to develop an anti-counterfeiting composite material with a high luminescence asymmetry factor and excellent solution processing performance, which can achieve multi-dimensional encryption and anti-counterfeiting to improve the level of information security. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides an anti-counterfeiting ink and a preparation method and application thereof. By designing the specific composition of the anti-counterfeiting composite material, an anti-counterfeiting ink with circularly polarized light that is easy to process and write is obtained. Multi-dimensional encryption anti-counterfeiting is used to improve the level of information security and expand its application in the anti-counterfeiting field.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides an anti-counterfeiting ink, the anti-counterfeiting ink comprising polymer chiral mesoporous microspheres, a fluorescent dye and a polymer solution;

[0009] The polymer chiral mesoporous microspheres have a photon bandgap;

[0010] The central wavelength of the photon bandgap is recorded as x nm, the width of the photon bandgap is recorded as y nm, the emission wavelength of the fluorescent dye is recorded as z nm, |xz|≤0.5y, where |xz| can be, for example, 0.4y, 0.3y, 0.2y, 0.1y or 0.

[0011] The present invention uses polymer chiral mesoporous microspheres with photon bandgap to match with fluorescent dyes of corresponding emission wavelengths. After coupling the photon bandgap with the emission wavelength of the fluorescent dye, a circularly polarized luminescent material can be obtained. The material is evenly and stably dispersed in a polymer solution, so that the obtained anti-counterfeiting ink is easy to write. When the anti-counterfeiting ink is used for anti-counterfeiting, it has the concealment of circularly polarized light, and anti-counterfeiting inks made of different fluorescent dyes and polymer chiral mesoporous microspheres of different chirality can be used at the same time to add interference information to encrypt real information. Different written contents can be observed under the irradiation of excitation light of different bands and through different circular polarizers, which greatly improves information security.

[0012] Preferably, the emission wavelength of the fluorescent dye is located at the center of the photon bandgap, ie, xz=0.

[0013] Preferably, the center position of the photon bandgap is 450-800 nm, for example, it may be 500 nm, 550 nm, 600 nm, 650 nm, 680 nm, 700 nm, 720 nm, 750 nm or 780 nm.

[0014] Preferably, the width of the photon bandgap is 100-200 nm, for example, 110 nm, 130 nm, 150 nm, 170 nm or 190 nm.

[0015] Preferably, the emission wavelength of the fluorescent dye is ≥400 nm, for example, it can be 800 nm, 750 nm, 720 nm, 700 nm, 650 nm, 600 nm, 550 nm, 500 nm or 450 nm, etc. When the emission wavelength of the fluorescent dye matches the photon bandgap wavelength, the highest luminescence asymmetry factor is obtained.

[0016] Preferably, the photon bandgap is greater than the half-wave width of the emission wavelength of the fluorescent dye.

[0017] Preferably, the fluorescent dye is loaded on the polymer chiral mesoporous microspheres.

[0018] Preferably, the polymer chiral mesoporous microspheres are ellipsoidal.

[0019] Preferably, the concentration of the polymer chiral mesoporous microspheres in the anti-counterfeiting ink is 10-100 mg / g, for example, 20 mg / g, 30 mg / g, 50 mg / g, 70 mg / g or 90 mg / g.

[0020] Preferably, the mass ratio of the polymer chiral mesoporous microspheres to the fluorescent dye is (5-300):1, wherein the specific value of (5-300) can be, for example, 10, 20, 50, 80, 100, 120, 150, 200 or 250.

[0021] Preferably, in parts by weight, the raw materials for preparing the polymer chiral mesoporous microspheres include 100 parts of nematic liquid crystal, 0.01-0.8 parts of chiral dopant (for example, 0.05 parts, 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts or 0.7 parts, etc.), 30-80 parts of polymerized monomer (for example, 35 parts, 40 parts, 50 parts, 60 parts or 70 parts, etc.), 5-15 parts of cross-linking agent (for example, 6 parts, 8 parts, 10 parts, 12 parts or 14 parts, etc.) and 1-5 parts of initiator (for example, 1.5 parts, 2 parts, 3 parts, 4 parts or 4.5 parts, etc.).

[0022] Preferably, the nematic liquid crystal includes any one of nematic liquid crystal HTG135200, nematic liquid crystal SLC1717, nematic liquid crystal E7 or nematic liquid crystal 5CB, or a combination of at least two thereof, and more preferably the nematic liquid crystal HTG135200.

[0023] Preferably, the chiral dopant includes any one of R5011, S5011, S811 or R811 or a combination of at least two thereof, and more preferably R5011 or S5011.

[0024] Preferably, the polymerizable monomer includes an acrylic ester liquid crystal monomer.

[0025] Preferably, the polymerizable monomer includes any one or a combination of at least two of 1,4-bis[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene (C6M), 4-[[6-[(1-oxo-2-propenyl)oxy]hexyl]oxy]benzoic acid 4-methoxyphenyl ester (RM105) or 4-(3-acryloyloxypropoxy)benzoic acid 2-methyl-1,4-phenyl ester (RM257), and C6M is further preferred.

[0026] Preferably, the crosslinking agent comprises an acrylate crosslinking agent.

[0027] Preferably, the crosslinking agent comprises any one or a combination of at least two of trimethylolpropane triacrylate (TMPTA), 1,6-hexanediol diacrylate or isooctyl methacrylate;

[0028] Preferably, the initiator is a photoinitiator.

[0029] For example, the photoinitiator may be 2,2-dimethoxy-2-phenylacetophenone (I651), methyl benzoylformate (MBF), or the like.

[0030] Preferably, the method for preparing the polymer chiral mesoporous microspheres comprises the following steps:

[0031] The nematic phase liquid crystal, chiral dopant, polymerizable monomer, crosslinking agent and initiator are mixed, dispersed evenly in a dispersion solution, polymerization is initiated, and the nematic phase liquid crystal is washed away to obtain the polymer chiral mesoporous microspheres.

[0032] In the present invention, the raw materials for preparing polymer chiral mesoporous microspheres include nematic liquid crystal, chiral dopant, polymerization monomer, crosslinking agent and initiator. The chiral nematic liquid crystal is used as a template, and the nematic liquid crystal is washed away to obtain polymer chiral mesoporous microspheres with randomly distributed holes. The photon bandgap of the chiral nematic liquid crystal is effectively retained, and the luminescence quenching of the luminescent molecules by the strong polar environment of the liquid crystal is avoided. The porous structure is conducive to loading fluorescent dyes, so as to obtain anti-counterfeiting ink with circularly polarized luminescence and easy processing and writing.

[0033] Preferably, the mass ratio of the nematic liquid crystal to the dispersed solution is 1:(10-50), wherein the specific value of (10-50) can be, for example, 15, 20, 25, 30, 35, 40 or 45.

[0034] Preferably, the dispersion solution comprises an aqueous polymer solution.

[0035] Preferably, the aqueous polymer solution comprises an aqueous polyvinyl alcohol solution.

[0036] Preferably, the polymer in the dispersion solution is the same as the polymer in the polymer solution.

[0037] As a preferred technical solution of the present invention, the polymer chiral mesoporous microspheres are prepared using a dispersed solution that is the same as the polymer solution in the anti-counterfeiting ink. This allows the prepared polymer chiral mesoporous microspheres to have good compatibility with the polymer solution, forming an anti-counterfeiting ink that is evenly dispersed and stable, thereby improving the solution processability and making it easy to write and store.

[0038] Preferably, the mass concentration of the polymer in the polymer aqueous solution is 1-15%, for example, 2%, 3%, 5%, 8%, 10% or 12%.

[0039] Preferably, after the dispersion is uniform, the resulting solution is applied into a thin layer and dried.

[0040] As a preferred technical solution of the present invention, by coating a mixed solution of nematic liquid crystal, chiral dopant, polymerization monomer, cross-linking agent and initiator into a thin layer and drying it, a film can be formed and stress can be generated, and the liquid crystal emulsion can be confined in the film and flattened into an ellipsoidal shape, resulting in a larger luminescence asymmetry factor value, thereby improving the encryption ability of the anti-counterfeiting ink.

[0041] Preferably, the thickness of the thin layer is 200-1000 μm, for example, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm or 900 μm.

[0042] Preferably, the operation of initiating polymerization comprises irradiation with light.

[0043] Preferably, the wavelength of the light is 300-500 nm, for example, 320 nm, 350 nm, 380 nm, 400 nm, 420 nm, 450 nm or 480 nm.

[0044] Preferably, the illumination time is 10-60 min, for example, 15 min, 20 min, 30 min, 40 min or 50 min.

[0045] Preferably, the solvent for washing away the nematic liquid crystal includes any one of water, n-hexane, cyclohexane or ethanol, or a combination of at least two of them.

[0046] Preferably, the fluorescent dye comprises any one of organic dyes, quantum dots, nanoparticles or carbon dots, or a combination of at least two of them.

[0047] It should be noted that there is no special restriction on the specific selection of organic dyes in the present invention. All commonly used organic dyes in the art are applicable, including but not limited to: Nile red, coumarin-6, perylene, 9,10-diphenylanthracene, cyanine dye cy5 or cyanine dye cy7, etc.

[0048] It should be noted that the present invention has no special restrictions on the specific selection of quantum dots. All commonly used quantum dots in the art are applicable, including but not limited to CdSe / ZnS visible light quantum dots, CuInSe 2 Quantum dots, PbS quantum dots, Ag 2 S quantum dots, etc.

[0049] It should also be noted that the present invention does not have any special restrictions on the specific selection of nanoparticles. All commonly used nanoparticles in the field are applicable, including but not limited to: 1% Tm upconversion nanoparticles, 20% Ca@NaYF4 nanoparticles, Yb-doped perovskite nanocrystals, etc.

[0050] It should be noted that the present invention has no special restrictions on the preparation method of the fluorescent dye. For example, the CuInSe 2 For the preparation method of quantum dots, please refer to the preparation method recorded in “Biocompatible near-infrared quantum dots delivered to the skin by microneedle patches record vaccination, Science Translational Medicine 11 (2019) eaay7162”.

[0051] The preparation method of the carbon dots can refer to the preparation method described in “Molecular Fluorescence in Citric Acid-Based Carbon Dots, The Journal of Physical Chemistry C 121 (2017) 2014-2022”.

[0052] The preparation method of the Yb-doped perovskite nanocrystals can refer to the preparation method described in “Picosecond Quantum Cutting Generates Photoluminescence Quantum Yields Over 100% in Ytterbium-Doped CsPbCl3 Nanocrystals, Nano Letters 18 (2018) 3792-3799”.

[0053] Preferably, the solvent of the polymer solution comprises water.

[0054] Preferably, the polymer in the polymer solution includes any one of polyvinyl alcohol, gelatin, gum arabic, polymethyl methacrylate or polyethylene glycol, or a combination of at least two thereof, and polyvinyl alcohol is more preferably used.

[0055] Preferably, the mass concentration of the polymer in the polymer solution is 2-15%, for example, 3%, 5%, 8%, 10%, 12% or 14%.

[0056] Preferably, the weight average molecular weight of the polymer in the polymer solution is 9000-23000 g / mol, for example, 10000 g / mol, 12000 g / mol, 15000 g / mol, 18000 g / mol, 20000 g / mol or 22000 g / mol.

[0057] In a second aspect, the present invention provides a method for preparing the anti-counterfeiting ink as described in the first aspect, the preparation method comprising the following steps:

[0058] The polymer chiral mesoporous microspheres are immersed in a fluorescent dye solution, separated to obtain the polymer chiral mesoporous microspheres loaded with fluorescent dye, and the polymer chiral mesoporous microspheres loaded with fluorescent dye are dispersed in a polymer solution to obtain the anti-counterfeiting ink.

[0059] Preferably, the mass concentration of the fluorescent dye in the fluorescent dye solution is 1-5 mg / mL, for example, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, 3.5 mg / mL, 4 mg / mL or 4.5 mg / mL.

[0060] Preferably, the solvent of the fluorescent dye solution includes any one of n-hexane, toluene and cyclohexane, or a combination of at least two of them.

[0061] Preferably, the soaking time is 10-120 min, for example, 20 min, 30 min, 40 min, 50 min, 60 min, 80 min or 100 min, etc., more preferably 60 min.

[0062] Preferably, the immersion temperature is ≤50°C, for example, it may be 45°C, 40°C, 35°C, 30°C, 25°C, 20°C, 15°C, 10°C or 5°C, and more preferably 25°C.

[0063] Preferably, the separation is followed by drying.

[0064] In a third aspect, the present invention provides a use of the anti-counterfeiting ink as described in the first aspect in encrypted information or anti-counterfeiting patterns.

[0065] Preferably, the encrypted information or anti-counterfeiting pattern is drawn by encryption ink and interference ink;

[0066] The encrypted ink includes an anti-counterfeiting ink containing polymer chiral mesoporous microspheres with a single chirality and a fluorescent dye with a single excitation wavelength;

[0067] The interference ink includes an anti-counterfeiting ink having a different chirality from the encryption ink and / or an excitation wavelength of a fluorescent dye.

[0068] When the anti-counterfeiting ink provided by the present invention is used for encryption and anti-counterfeiting, a plurality of anti-counterfeiting inks are used for coordination, which are respectively used as encryption ink for recording real information and interference ink for recording interference information, and different written contents are observed under the irradiation of excitation light of different wavelengths and through different circular polarizers. The chirality of the interference ink and the encryption ink is different from the excitation wavelength of the fluorescent dye, but the same. Since the anti-counterfeiting ink has the property of circularly polarized luminescence, the correct encrypted information or anti-counterfeiting pattern can only be observed by using the correct circular polarizer and excitation light at the same time, thereby improving information security through multiple dimensions.

[0069] Compared with the prior art, the present invention has at least the following beneficial effects:

[0070] The anti-counterfeiting ink provided by the present invention comprises polymer chiral mesoporous microspheres, fluorescent dyes and polymer solutions. The fluorescent dyes can be loaded onto the polymer chiral mesoporous microspheres in any solution processing method, and have great processability. The photon bandgap of the polymer chiral mesoporous microspheres is coupled with the luminescent wavelength of the fluorescent dye to obtain a high g lum The circularly polarized luminescent material can be evenly and stably dispersed in the polymer solution to form an anti-counterfeiting ink that is easy to write. When the anti-counterfeiting ink is used for encryption and anti-counterfeiting, the corresponding circular polarizer and excitation light are required to observe the real information. In addition, other interference inks can be used in combination, which is easy to be doped with interference information, greatly improving information security through multiple dimensions. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 The circularly polarized luminescence spectra of the anti-counterfeiting inks obtained in Examples 1 and 2 are shown;

[0072] Figure 2 : is the luminescence asymmetry factor curve of the anti-counterfeiting ink obtained in Examples 1 and 2;

[0073] Figure 3 This is the image of the anti-counterfeiting pattern obtained in Application Example 1 under sunlight;

[0074] Figure 4This is the image of the anti-counterfeiting pattern obtained in Application Example 1 under ultraviolet light;

[0075] Figure 5 This is the image of the anti-counterfeiting pattern obtained in Application Example 1 observed under ultraviolet light and through a circular polarizer. DETAILED DESCRIPTION

[0076] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0077] In the following specific implementation of the present invention, the materials involved are as follows:

[0078] 1) Nematic liquid crystal: HTG135200, Jiangsu Hecheng Display Technology Co., Ltd.;

[0079] 2) Chiral dopants: R5011, S5011;

[0080] 3) Polymerization monomer: 1,4-bis[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene (C6M);

[0081] 4) Crosslinking agent: trimethylolpropane triacrylate (TMPTA);

[0082] 5) Photoinitiator: benzil dimethyl ether (I-651);

[0083] 6) Fluorescent dyes

[0084] Coumarin-6, TCI (Shanghai) Chemical Industry Development Co., Ltd., N0659, chemiluminescence emission wavelength is 530 nm;

[0085] Nile Red, TCI (Shanghai) Chemical Industry Development Co., Ltd., P1137, chemiluminescence emission wavelength is 625nm;

[0086] 9,10-Diphenylanthracene, Shanghai Jizhi Biochemical Technology Co., Ltd., C15840, chemiluminescence emission wavelength is 430nm;

[0087] Cyanocyanine dye cy7, Shanghai Aladdin Biochemical Technology Co., Ltd., C196722, chemiluminescent emission wavelength is 780nm;

[0088] 7) Polymer

[0089] Polyvinyl alcohol, Shanghai MacLean Biochemical Technology Co., Ltd., P875083.

[0090] Example 1

[0091] An S-anti-counterfeiting ink, comprising polymer chiral mesoporous microspheres (photon bandgap center position is 610nm, width is 200nm), fluorescent dye (Nile red, emission wavelength is 625nm, half peak width is 50nm) and polyvinyl alcohol aqueous solution (polyvinyl alcohol mass concentration is 10%);

[0092] The anti-counterfeiting ink is prepared by the following method:

[0093] Nematic liquid crystal HTG135200 100 mg, chiral dopant S5011 0.18 mg, C6M 50 mg, crosslinker TMPTA 7.8 mg, and photoinitiator I651 2.5 mg were fully mixed, dispersed in a polyvinyl alcohol aqueous solution (3 g, wherein the polyvinyl alcohol concentration is 10 wt%), and after sufficient stirring, coated into a thin layer with a thickness of 600 μm, dried at 50° C. for 6 hours, annealed at 80° C., polymerized with 365 nm ultraviolet light for 20 minutes, washed with water and n-hexane in turn, and finally dried at 50° C. for 6 hours to obtain ellipsoidal chiral mesoporous microspheres of the polymer.

[0094] The fluorescent dye was dispersed in 3 mL of n-hexane to form a 2 mg / mL solution, 50 mg of the above-mentioned polymer chiral mesoporous microspheres were added, and the solution was immersed at 25° C. for 1 hour, centrifuged, dried at 50° C. for 6 hours, and a polyvinyl alcohol aqueous solution (3 g, polyvinyl alcohol mass concentration 10%) was added and stirred thoroughly to obtain the S-anti-counterfeiting ink.

[0095] Example 2

[0096] An R-anti-counterfeiting ink, the R-anti-counterfeiting ink is different from Example 1 only in that the chiral dopant S5011 in the preparation of polymer chiral mesoporous microspheres is replaced by the chiral dopant R5011, and other materials and preparation methods are the same as those in Example 1.

[0097] Example 3

[0098] A S-anti-counterfeiting ink, the difference between the S-anti-counterfeiting ink and Example 1 is that the amount of chiral dopant S5011 used is 0.24 mg (at this time, the center position of the photon bandgap of the obtained polymer chiral mesoporous microspheres is 450 nm, and the width is 200 nm) and the fluorescent dye is replaced by 9,10 diphenylanthracene (the emission wavelength is 430 nm, and the half-peak width is 60 nm). Other materials, amounts and preparation methods are the same as those in Example 1.

[0099] Example 4

[0100] An R-anti-counterfeiting ink, the R-anti-counterfeiting ink is different from Example 3 only in that the chiral dopant S5011 in the preparation of polymer chiral mesoporous microspheres is replaced by the chiral dopant R5011, and other materials, amounts and preparation methods are the same as those in Example 3.

[0101] Example 5

[0102] A S-anti-counterfeiting ink, the difference between the S-anti-counterfeiting ink and Example 1 is that the amount of chiral dopant S5011 is 0.20 mg (at this time, the center position of the photon bandgap of the obtained polymer chiral mesoporous microspheres is 520 nm, and the width is 200 nm) and the fluorescent dye is replaced by coumarin-6 (the emission wavelength is 530 nm, and the half-peak width is 50 nm). Other materials, amounts and preparation methods are the same as those in Example 1.

[0103] Example 6

[0104] An R-anti-counterfeiting ink, the R-anti-counterfeiting ink is different from Example 5 only in that the chiral dopant S5011 in the preparation of polymer chiral mesoporous microspheres is replaced by the chiral dopant R5011, and other materials, amounts and preparation methods are the same as those in Example 5.

[0105] Example 7

[0106] A S-anti-counterfeiting ink, the difference between the S-anti-counterfeiting ink and Example 1 is that the amount of chiral dopant S5011 is 0.14 mg (at this time, the center position of the photon bandgap of the obtained polymer chiral mesoporous microspheres is 780 nm, and the width is 200 nm) and the fluorescent dye is replaced by cyanine dye cy7 (emission wavelength is 780 nm, half-peak width is 50 nm), and other materials, amounts and preparation methods are the same as those in Example 1.

[0107] Example 8

[0108] An R-anti-counterfeiting ink, the R-anti-counterfeiting ink is different from Example 7 only in that the chiral dopant S5011 in the preparation of polymer chiral mesoporous microspheres is replaced by the chiral dopant R5011, and other materials, amounts and preparation methods are the same as those in Example 7.

[0109] Example 9

[0110] An S-anti-counterfeiting ink, the difference between the S-anti-counterfeiting ink and Example 1 is that the fluorescent dye is dispersed with 3 mL of n-hexane to form a 0.05 mg / mL solution, and other materials, amounts and preparation methods are the same as those in Example 1.

[0111] Example 10

[0112] An S-anti-counterfeiting ink, the difference between the S-anti-counterfeiting ink and Example 1 is that the fluorescent dye is dispersed with 3 mL of n-hexane to form a 5 mg / mL solution, and other materials, amounts and preparation methods are the same as those in Example 1.

[0113] Embodiment 11

[0114] An S-anti-counterfeiting ink, the difference between the S-anti-counterfeiting ink and Example 1 is that the polyvinyl alcohol aqueous solution is replaced by an equal amount and concentration of polymethyl methacrylate (Shanghai McLean Biochemical Technology Co., Ltd., P821347), and other materials, amounts and preparation methods are the same as those in Example 1.

[0115] Example 12

[0116] A S-anti-counterfeiting ink, which differs from Example 1 in that in the preparation of polymer chiral mesoporous microspheres, nematic liquid crystal, chiral dopant, C6M, cross-linking agent, and photoinitiator are mixed and dispersed in a polyvinyl alcohol aqueous solution with a polyvinyl alcohol mass concentration of 0.5%, and other materials, amounts, and preparation methods are the same as those in Example 1.

[0117] Example 13

[0118] A S-anti-counterfeiting ink, which differs from Example 1 in that in the preparation of polymer chiral mesoporous microspheres, nematic liquid crystal, chiral dopant, C6M, cross-linking agent, and photoinitiator are mixed and dispersed in a polyvinyl alcohol aqueous solution with a polyvinyl alcohol mass concentration of 20%, and other materials, amounts, and preparation methods are the same as those in Example 1.

[0119] Embodiment 14

[0120] An S-anti-counterfeiting ink. The difference between the S-anti-counterfeiting ink and Example 1 is that the S-anti-counterfeiting ink is coated into a thin layer with a film thickness of 50 μm, and other materials, amounts and preparation methods are the same as those in Example 1.

[0121] Embodiment 15

[0122] An S-anti-counterfeiting ink, the S-anti-counterfeiting ink is different from Example 1 in that the S-anti-counterfeiting ink is coated into a thin layer with a film thickness of 2000 μm, and other materials, amounts and preparation methods are the same as those in Example 1.

[0123] Comparative Example 1

[0124] An S-anti-counterfeiting ink, comprising polymer chiral mesoporous microspheres (photon bandgap center position is 610nm, width is 200nm), fluorescent dye (9,10 diphenylanthracene, maximum emission wavelength is 430nm, half peak width is 60nm) and polyvinyl alcohol aqueous solution (polyvinyl alcohol mass concentration is 10%);

[0125] The anti-counterfeiting ink is prepared by the following method:

[0126] Nematic liquid crystal HTG135200 100 mg, chiral dopant S5011 0.18 mg, C6M 50 mg, crosslinker TMPTA 7.8 mg, and photoinitiator I651 2.5 mg were fully mixed, dispersed in a polyvinyl alcohol aqueous solution (3 g, wherein the polyvinyl alcohol concentration is 10 wt%), and after sufficient stirring, coated into a thin layer with a thickness of 600 μm, dried at 50° C. for 6 hours, annealed at 80° C., polymerized with 365 nm ultraviolet light for 20 minutes, washed with water and n-hexane in turn, and finally dried at 50° C. for 6 hours to obtain ellipsoidal chiral mesoporous microspheres of the polymer.

[0127] The fluorescent dye was dispersed in 3 mL of n-hexane to form a 2 mg / mL solution, 50 mg of the above-mentioned polymer chiral mesoporous microspheres were added, and the solution was immersed at 25°C for 1 hour. After centrifugation, the solution was dried at 50°C for 6 hours, and a polyvinyl alcohol aqueous solution (3 g, polyvinyl alcohol mass concentration 10%) was added and stirred thoroughly to obtain the S-anti-counterfeiting ink whose photon bandgap did not match the emission wavelength of the fluorescent dye.

[0128] Application Example 1

[0129] An anti-counterfeiting pattern is obtained by using the products obtained in Example 1 and Example 6 as ink, using a flexible electronic printer (model scientific 4), setting a program to draw the pattern, and drawing in a dispensing mode.

[0130] The luminescence asymmetry factor (g / cm2) of the anti-counterfeiting ink (wherein the total concentration of the polymer chiral mesoporous microspheres and the fluorescent dye is 300 mg / mL and the solvent is a polyvinyl alcohol aqueous solution with a mass concentration of 10%) was tested using a circular polarization fluorescence spectrometer (CPL-200) at an excitation wavelength of 365 nm. lum ), and the results are summarized in Table 1.

[0131] Table 1

[0132]

[0133]

[0134] The test results show that the anti-counterfeiting ink provided by the present invention couples the photon bandgap of the polymer chiral mesoporous microspheres with the emission wavelength of the fluorescent dye and is evenly and stably dispersed in the polymer solution to form an easy-to-write anti-counterfeiting ink. lum ∣≥0.1. Combined Figure 3-Figure 5It can be seen that when the anti-counterfeiting ink provided by the present invention is used to draw information, only when the correct circular polarizer and excitation light are used at the same time can the correct encrypted information or anti-counterfeiting pattern be observed, and the information security is excellent. By comparing Example 1 with Examples 9 and 10, it can be seen that the anti-counterfeiting ink obtained by the present invention has a higher circular polarized light asymmetry factor by further optimizing the ratio of polymer chiral mesoporous microspheres and fluorescent dyes.

[0135] By comparing Example 1 with Examples 12-15, it can be seen that the present invention further improves the luminescence asymmetry factor of the chiral mesoporous microspheres by optimizing the concentration of polyvinyl alcohol and the thickness of the coating layer during the preparation of the chiral mesoporous microspheres.

[0136] By comparing Example 1 with Comparative Example 1, it can be seen that the present invention can obtain a higher circularly polarized light asymmetry factor by matching the photon bandgap with the emission wavelength of the fluorescent dye.

[0137] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. An anti-counterfeiting ink, characterized in that: The anti-counterfeiting ink comprises polymer chiral mesoporous microspheres, fluorescent dye and polymer solution; The polymer chiral mesoporous microspheres have a photon bandgap; The central wavelength of the photon bandgap is recorded as x nm, the width of the photon bandgap is recorded as y nm, the emission wavelength of the fluorescent dye is recorded as z nm, and |xz|≤0.5y.

2. The anti-counterfeiting ink according to claim 1, characterized in that: The photon bandgap width is greater than the half-wave width of the emission wavelength of the fluorescent dye; Preferably, the emission wavelength of the fluorescent dye is ≥400nm; Preferably, the fluorescent dye is loaded on the polymer chiral mesoporous microspheres; Preferably, the polymer chiral mesoporous microspheres are ellipsoidal; Preferably, the concentration of the polymer chiral mesoporous microspheres in the anti-counterfeiting ink is 10-100 mg / g; Preferably, the mass ratio of the polymer chiral mesoporous microspheres to the fluorescent dye is (5-300):

1.

3. The anti-counterfeiting ink according to claim 1 or 2, characterized in that: The raw materials for preparing the polymer chiral mesoporous microspheres include 100 parts of nematic liquid crystal, 0.01-0.4 parts of chiral dopant, 30-80 parts of polymerizable monomer, 5-15 parts of crosslinking agent and 1-5 parts of initiator in parts by weight; Preferably, the nematic liquid crystal includes any one of nematic liquid crystal HTG135200, nematic liquid crystal SLC1717, nematic liquid crystal E7 or nematic liquid crystal 5CB, or a combination of at least two thereof, and more preferably the nematic liquid crystal HTG135200; Preferably, the chiral dopant includes any one of R5011, S5011, S811 or R811 or a combination of at least two thereof, and more preferably R5011 or S5011; Preferably, the polymerizable monomer comprises an acrylic ester liquid crystal monomer; Preferably, the polymerizable monomer includes any one of 1,4-bis[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene, 4-[[6-[(1-oxo-2-propenyl)oxy]hexyl]oxy]benzoic acid 4-methoxyphenyl ester or 4-(3-acryloyloxypropoxy)benzoic acid 2-methyl-1,4-phenyl ester or a combination of at least two thereof; Preferably, the cross-linking agent comprises an acrylate cross-linking agent; Preferably, the crosslinking agent includes any one or a combination of at least two of trimethylolpropane triacrylate, 1,6-hexanediol diacrylate or isooctyl methacrylate; Preferably, the initiator is a photoinitiator.

4. The anti-counterfeiting ink according to any one of claims 1 to 3, characterized in that: The method for preparing the polymer chiral mesoporous microspheres comprises the following steps: Mixing nematic liquid crystal, chiral dopant, polymerizable monomer, crosslinking agent and initiator, dispersing them evenly in a dispersion solution, initiating polymerization, washing away the nematic liquid crystal, and obtaining the polymer chiral mesoporous microspheres; Preferably, the mass ratio of the nematic liquid crystal to the dispersed solution is 1:(10-50); Preferably, the dispersion solution comprises an aqueous polymer solution; Preferably, the polymer aqueous solution comprises a polyvinyl alcohol aqueous solution; Preferably, the mass concentration of the polymer in the polymer aqueous solution is 1-15%; Preferably, after the dispersion is uniform, the resulting solution is applied into a thin layer and dried; Preferably, the operation of initiating polymerization comprises irradiation with light; Preferably, the wavelength of the light is 300-500nm; Preferably, the illumination time is 10-60 min; Preferably, the solvent for washing away the nematic liquid crystal includes any one of water, n-hexane, cyclohexane or ethanol, or a combination of at least two of them.

5. The anti-counterfeiting ink according to any one of claims 1 to 4, characterized in that: The fluorescent dye includes any one of organic dyes, quantum dots, nanoparticles or carbon dots, or a combination of at least two of them.

6. The anti-counterfeiting ink according to any one of claims 1 to 5, characterized in that: The solvent of the polymer solution includes water; Preferably, the polymer in the polymer solution includes any one of polyvinyl alcohol, gelatin, gum arabic, polymethyl methacrylate or polyethylene glycol, or a combination of at least two thereof, and more preferably polyvinyl alcohol; Preferably, the mass concentration of the polymer in the polymer solution is 2-15%; Preferably, the weight average molecular weight of the polymer in the polymer solution is 9000-23000 g / mol.

7. A method for preparing the anti-counterfeiting ink according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: The polymer chiral mesoporous microspheres are immersed in a fluorescent dye solution, separated to obtain the polymer chiral mesoporous microspheres loaded with fluorescent dye, and the polymer chiral mesoporous microspheres loaded with fluorescent dye are dispersed in a polymer solution to obtain the anti-counterfeiting ink.

8. The preparation method according to claim 7, characterized in that: The mass concentration of the fluorescent dye in the fluorescent dye solution is 1-5 mg / mL; Preferably, the solvent of the fluorescent dye solution includes any one of n-hexane, toluene, and cyclohexane, or a combination of at least two thereof; Preferably, the soaking time is 10-120 min; Preferably, the soaking temperature is ≤50°C; Preferably, the separation is followed by drying.

9. Use of the anti-counterfeiting ink as claimed in any one of claims 1 to 6 in encrypted information or anti-counterfeiting patterns.

10. The use according to claim 9, characterized in that: The encrypted information or anti-counterfeiting pattern is drawn by encryption ink and interference ink; The encrypted ink includes an anti-counterfeiting ink containing polymer chiral mesoporous microspheres with a single chirality and a fluorescent dye with a single excitation wavelength; The interference ink includes an anti-counterfeiting ink having a different chirality from the encryption ink and / or an excitation wavelength of a fluorescent dye.

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