Preparation method and application of bionic hydrogel anti-counterfeit label

Abstract

The invention discloses a preparation method and application of a bionic hydrogel anti-counterfeit label. The bionic hydrogel anti-counterfeit label comprises a substrate layer for bearing encrypted information and an information carrier layer adhered to the substrate layer. The preparation method comprises the following steps: uniformly mixing a monomer hydroxyethyl methylacrylate, a cross-linking agent ethylene glycol dimethacrylate and a photoinitiator phenyl bis (2, 4, 6-trimethylbenzoyl) phosphine oxide to obtain a solution A for preparing an anti-counterfeit label precursor; dissolving ammonium molybdate hydrate (Mo7) into deionized water to obtain a solution B for dipping; transferring the solution A into a shaping template, reacting in a substrate pattern area of a to-be-copied piece under ultraviolet light, condensing into gel, and soaking in the solution B, so as to obtain the bionic hydrogel anti-counterfeit label. And then pattern generation is carried out under ultraviolet light so as to achieve the design of secondary encryption. The prepared anti-counterfeit label is high in identification degree, due to the multi-layer encryption characteristic of the anti-counterfeit label, the anti-counterfeit safety is higher, and the encoding mode is simple and easy to operate. And information encryption with the highest coding capacity of 1010000 can be realized only by doping one element.

Description

Technical Field

[0001] The invention relates to the field of polymer material preparation, and in particular to a preparation method and application of a bionic hydrogel anti-counterfeiting label. Background Art

[0002] Hydrogel is formed by cross-linking hydrophilic polymer chains in water. It is a functional polymer material with a three-dimensional network structure. It is often used in medicine, agriculture and information fields. Regarding information storage, wafers, glass chips, etc. have high preparation technology barriers and expensive raw materials. Replacing them with hydrogel substrates can greatly reduce their production costs, and combining them with photocuring methods can further reduce the requirements for preparation technology.

[0003] Physical anti-counterfeiting technology mainly refers to physical printing anti-counterfeiting technology. Special printing processes and processing equipment are used to create unique trace features in printed products to achieve the purpose of anti-counterfeiting. Most of them use optical bionic information for encryption. Existing means often use plant templates, including lotus leaves, rose petals, rose leaves, ginkgo leaves, velvet arrowroot leaves and other plant leaves or petals. Considering that feathers have a complex cascade sliding lock system, the system consists of a flexible hook, a slide rail and a thorn at the end of the slide rail as the end structure. Due to its own structural characteristics, its texture shape also varies due to the difference in the applied force, so the range of optical anti-counterfeiting templates can be expanded. At the same time, the present invention is still applicable to the original anti-counterfeiting templates, such as leaves. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a bionic hydrogel anti-counterfeiting label.

[0005] The anti-counterfeiting label of the bionic hydrogel prepared by the present invention contains two layers of anti-counterfeiting information, namely, primary micro-texture encryption information and secondary optical selection area pattern information.

[0006] The characteristic value of the first-level micro-texture encryption information can be calculated by using the Hamming distance calculation formula.

[0007] The secondary optical selection pattern information is due to the characteristic color of molybdenum ions in the structure.

[0008] The steps of the preparation method of the bionic hydrogel anti-counterfeiting label include the following: S1, mix the monomer, crosslinker and photoinitiator and stir them evenly to obtain solution A, wherein the monomer is hydroxyethyl methacrylate, the crosslinker is ethylene glycol dimethacrylate, and the photoinitiator is phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide; S2, dissolve ammonium molybdate hydrate (Mo7) in deionized water to obtain solution B; S3, transfer the solution A mentioned in S1 to the glass substrate area carrying the feather substrate and polymerize and condense under ultraviolet light to form a primary bionic anti-counterfeiting hydrogel label. S4, after the primary bionic anti-counterfeiting hydrogel label is immersed in solution B, a film paper illumination template with a set pattern is selected and the secondary anti-counterfeiting information is mapped to its surface by ultraviolet light irradiation to obtain a secondary encrypted bionic hydrogel anti-counterfeiting label.

[0009] Preferably, in step S1, the content of the crosslinking agent is 0.4%-1% of the molar content of the monomer, and the content of the initiator is 1.6-3.2% of the molar content of the monomer.

[0010] Preferably, in step S2, ammonium molybdate hydrate (Mo7) is dissolved in deionized water to obtain solution B, wherein the content of Mo7 is 50 mmol / L, etc.

[0011] Preferably, the polymerization coagulation time in step S3 is 5 min.

[0012] Preferably, the ultraviolet light irradiation time in step S4 is 6 min.

[0013] Compared with the prior art, the present invention has the following beneficial effects: the present invention uses feather microtexture structure as anti-counterfeiting information for the first time, combined with biological encryption. The preparation process is simple and easy to operate, avoiding the cumbersome steps of repeated freezing and thawing required by the existing hydrogel anti-counterfeiting labels. At the same time, the prepared anti-counterfeiting label has the characteristics of information writing, erasing, rewriting, and re-erasing, which not only realizes the information being burned after reading but also saves material resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a diagram of the preparation process of the anti-counterfeiting label prepared by the present invention.

[0015] Figure 2 Schematic diagram of the anti-counterfeiting label preparation process and the writing, erasure and re-writing of information.

[0016] Figure 3 This is the flow chart of micro-texture feature value calculation and encrypted information recognition.

[0017] Figure 4 Comparison diagram of stress and strain for different examples. DETAILED DESCRIPTION

[0018] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0019] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

[0020] like Figure 1 The color conversion rules and color change mechanisms provided by the preliminary experiments can be determined Figure 2 The information writing time is then used to write the anti-counterfeiting label information. Figure 2 As shown, the prepared anti-counterfeiting label contains two levels of encrypted information. They are the first level micro-texture encryption information and the second level optical selection pattern information. In the case of pre-delivered user feature values, according to Figure 3 The characteristic value of the anti-counterfeiting label is compared to see if it matches. If it matches, the mark is decrypted at the first level to identify its image; otherwise, it is marked as a counterfeit label.

[0021] To determine the light response time, the following Figure 1 The pre-experiment shown in the figure. It can be found that the prefabricated substrate begins to change color after 20 seconds under the irradiation of 254 nm ultraviolet light, and its color change gradually deepens with time. XPS test was carried out to analyze its principle. The upper and lower figures on the right are the comparison before and after ultraviolet light irradiation. Among them, the Mo(VI) absorption peak was observed at the binding energy of 232.49 eV and 235.69 eV. The Mo(V) absorption peak appeared at 231.79 eV and 234.99 eV. The valence state of the molybdenum element was synthesized by the Gaussian fitting method. The black solid line is the result of the fitting calculation, which is consistent with the test value. The calculated spectrum was integrated to obtain the area for calculating the ratio of the two valence states. The ratio of Mo(V) / Mo before ultraviolet light irradiation was 25.48%. After ultraviolet irradiation, the binding energy of the gel changed to a certain extent, and the Mo(V) / Mo value increased significantly to 40.81%. It can be seen that Mo(VI) in the gel undergoes photoreduction after ultraviolet light irradiation, thereby producing photochromism.

[0022] Example 1

[0023] The present invention provides a method for preparing a bionic hydrogel anti-counterfeiting label, referring to Figure 2 The preparation method described in (a) comprises the following steps: S1, hydroxyethyl methacrylate, ethylene glycol dimethacrylate, phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide are mixed and stirred to obtain solution A, wherein the content of the crosslinker is 1% of the molar content of the monomer, and the content of the initiator is 1.6% of the molar content of the monomer; S2, ammonium molybdate hydrate (Mo7) is dissolved in deionized water to obtain solution B, wherein the content of Mo7 is 50 mmol / L; S3, the solution A mentioned in S1 is transferred to the glass substrate area carrying the feather substrate and polymerized and condensed under ultraviolet light to form a primary bionic anti-counterfeiting hydrogel label, and the polymerization and condensation time is 5 min. S4, after the primary bionic anti-counterfeiting hydrogel label is immersed in solution B, a film paper illumination template with a set pattern is selected, and the secondary anti-counterfeiting information is mapped to its surface by ultraviolet light irradiation to obtain a secondary encrypted bionic hydrogel anti-counterfeiting label, and the ultraviolet light irradiation time is 6 min.

[0024] Refer to Figure 2 (b) The butterfly pattern is mapped onto the primary anti-counterfeiting label with a micro-texture structure. The information retention time is observed. At room temperature, the information can be completely eliminated after about 18 hours, and the imaging effect is not affected after re-mapping.

[0025] Reference Figure 3 , explain the steps of using the anti-counterfeiting label. Figure 2 The bionic hydrogel anti-counterfeiting label is prepared according to the preparation steps, and the characteristic values ​​are calculated, and the results are a=0.1, b=0.7, and the characteristic values ​​are further transmitted to the user. The user receives the characteristic values ​​and the bionic hydrogel anti-counterfeiting label entity. An electronic device is used to check whether the characteristic values ​​match. If they match, the image features are further identified to obtain the original image information. After the information disappears, the label can be reused.

[0026] Example 2

[0027] The present invention provides a method for preparing a bionic hydrogel anti-counterfeiting label, referring to Figure 2 The preparation method described in (a) comprises the following steps: S1, hydroxyethyl methacrylate, ethylene glycol dimethacrylate, phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide are mixed and stirred to obtain solution A, wherein the content of the crosslinker is 0.4% of the molar content of the monomer, and the content of the initiator is 1.6% of the molar content of the monomer; S2, ammonium molybdate hydrate (Mo7) is dissolved in deionized water to obtain solution B, wherein the content of Mo7 is 50 mmol / L; S3, the solution A mentioned in S1 is transferred to the glass substrate area carrying the feather substrate and polymerized and condensed under ultraviolet light to form a primary bionic anti-counterfeiting hydrogel label, and the polymerization and condensation time is 5 min. S4, after the primary bionic anti-counterfeiting hydrogel label is immersed in solution B, a film paper illumination template with a set pattern is selected, and the secondary anti-counterfeiting information is mapped to its surface by ultraviolet light irradiation to obtain a secondary encrypted bionic hydrogel anti-counterfeiting label, and the ultraviolet light irradiation time is 6 min.

[0028] Example 3

[0029] The present invention provides a method for preparing a bionic hydrogel anti-counterfeiting label, referring to Figure 2 The preparation method described in (a) comprises the following steps: S1, hydroxyethyl methacrylate, ethylene glycol dimethacrylate, phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide are mixed and stirred to obtain solution A, wherein the content of the crosslinker is 1% of the molar content of the monomer, and the content of the initiator is 3.2% of the molar content of the monomer; S2, ammonium molybdate hydrate (Mo7) is dissolved in deionized water to obtain solution B, wherein the content of Mo7 is 50 mmol / L; S3, the solution A mentioned in S1 is transferred to the glass substrate area carrying the feather substrate and polymerized and condensed under ultraviolet light to form a primary bionic anti-counterfeiting hydrogel label, and the polymerization and condensation time is 5 min. S4, after the primary bionic anti-counterfeiting hydrogel label is immersed in solution B, a film paper illumination template with a set pattern is selected, and the secondary anti-counterfeiting information is mapped to its surface by ultraviolet light irradiation to obtain a secondary encrypted bionic hydrogel anti-counterfeiting label, and the ultraviolet light irradiation time is 6 min.

[0030] The stress-strain test was conducted on the A solution-cured precursor in Examples 1, 2, and 3 with different crosslinking agent monomer ratios. The results are as follows: Figure 4 As shown, the specific parameters of the test component are shown in the attached figure to clarify its tensile properties.

[0031] Microtexture feature value calculation and encrypted information recognition were performed for different substrates in Examples 2 and 3, and the results are as follows: Figure 3 shown.

[0032] The above embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. The present invention is not limited to the detailed description of the above embodiments. For those skilled in the art, without departing from the principles and spirit of the present invention, various changes, modifications, substitutions and variations are made to these embodiments, which still fall within the scope of protection of the present invention.

Claims

1. An anti-counterfeiting label based on bionic hydrogel, characterized in that: The anti-counterfeiting label includes one or more transparent substrates, the transparent substrates include groove patterns and a plane for placing the substrate of the to-be-copied object, the groove patterns are used for macroscopic structural shaping, and the to-be-copied object is used for microscopic bionic coding. Then, the template ultraviolet light is irradiated on the shaped surface to generate an encrypted pattern to prepare a multi-layer encrypted label containing two characteristic values.

2. The anti-counterfeiting label based on biomimetic hydrogel according to claim 1, characterized in that: The bionic hydrogel anti-counterfeiting label can be prepared by the following steps: S1, mixing and stirring the monomer, the cross-linking agent, and the photoinitiator to obtain solution A, wherein the monomer is hydroxyethyl methacrylate, the cross-linking agent is ethylene glycol dimethacrylate, and the photoinitiator is phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide; S2, dissolving ammonium molybdate hydrate (Mo7) in deionized water to obtain solution B; S3, transferring the solution A mentioned in S1 to the glass substrate area carrying the feather substrate and polymerizing and condensing it under ultraviolet light to form a primary bionic anti-counterfeiting hydrogel label. S4, selecting a film paper illumination template with a set pattern and mapping the secondary anti-counterfeiting information to the label surface prepared in step S3 by ultraviolet light irradiation to obtain a secondary encrypted bionic hydrogel anti-counterfeiting label.

3. The anti-counterfeiting label based on biomimetic hydrogel according to claim 1, characterized in that: The calculation formula of the coding capacity of the bionic hydrogel anti-counterfeiting label is: coding capacity = M N , where M is the number of optical response signals generated by any point in the substrate layer, M=2,10, and N is the total number of all points in the substrate layer, N=10×10, 50×50, 100×100.

4. The anti-counterfeiting label based on biomimetic hydrogel according to claim 1, characterized in that: The content of the crosslinking agent is 1%-2% of the molar content of the monomer, and the content of the initiator is 1.6%-2% of the molar content of the monomer.

5. The anti-counterfeiting label based on biomimetic hydrogel according to claim 1, characterized in that: The primary coding pattern is a microstructure pattern of the to-be-copied part, and the secondary coding pattern is a selected area encryption pattern obtained by ultraviolet light mapping.

6. The anti-counterfeiting label based on biomimetic hydrogel according to claim 1, characterized in that: The transparent substrate is glass, PDMS or acrylic.

7. The anti-counterfeiting label based on biomimetic hydrogel according to claim 1, characterized in that: The object to be replicated may be a biological structure with micro-texture features such as feathers and leaves.

8. The anti-counterfeiting label based on biomimetic hydrogel according to claim 1, characterized in that: The characteristic values ​​are respectively the Hamming distance and the Hamming inner distance. The calculation formula of the Hamming distance is: a(x,y)=∑x[i]⊕y[i], where i=1,..n-1, x, y are n-bit codes obtained by binarizing or decimalizing two different label scan images, and ⊕ represents exclusive OR. The calculation formula of the Hamming inner distance is: b(x,y)=∑x[i]⊕x[i+1], where i=1,..n-1, and satisfies x[n]=x[1], x, y are n-bit codes obtained by binarizing or decimalizing the label scan images, and ⊕ represents exclusive OR.

9. The anti-counterfeiting label based on biomimetic hydrogel according to any one of claims 1 to 8, characterized in that: The anti-counterfeiting label can be scanned and verified by an electronic device for its bionic microstructure, so as to be applied to read and verify identity information; and further present an encrypted image under daily lighting.

10. The biomimetic hydrogel-based anti-counterfeiting label according to any one of claims 1 to 8, characterized in that: The ciphertext information of the anti-counterfeiting label can be encrypted and destroyed.

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