Magnetic anti-counterfeiting aluminum-foil paper and preparation process thereof

Abstract

The invention relates to the technical field of anti-counterfeiting aluminum-foil paper, and discloses magnetic anti-counterfeiting aluminum-foil paper and a preparation process thereof.The magnetic anti-counterfeiting aluminum-foil paper is composed of aluminum-foil paper base paper and an anti-counterfeiting layer on the surface of the aluminum-foil paper base paper; wherein the anti-counterfeiting layer is obtained by curing a double anti-counterfeiting coating; the dual anti-counterfeiting coating comprises a first component and a second component, wherein the first component is prepared from the following raw materials: bisphenol A type epoxy resin, magnetic nano Fe3O4, temperature-control color-changing microcapsules, deionized water, a silane coupling agent and a dispersing agent; the second component comprises the following raw materials: an adhesive curing agent, dimethyl silicone oil, an antioxidant and deionized water; the magnetic anti-counterfeiting aluminum-foil paper prepared by the invention has double anti-counterfeiting properties of magnetism and temperature change, and has a lasting anti-counterfeiting effect, so that the service life of the magnetic anti-counterfeiting aluminum-foil paper is greatly prolonged, and the magnetic anti-counterfeiting aluminum-foil paper can meet the use requirements of various fields.

Description

Technical Field

[0001] The present invention relates to the technical field of anti-counterfeiting aluminum foil paper, and particularly relates to a magnetic anti-counterfeiting aluminum foil paper and a preparation process thereof. Background Art

[0002] With the progress of the times and the rapid development of the packaging industry, aluminum foil paper is increasingly widely used in food, handicrafts, cigarettes, gift packaging, etc. due to its excellent light-shielding performance, moisture-proof performance and decorative performance. However, with the increase in market demand, the problem of counterfeiting of genuine products has become increasingly serious, and ordinary anti-counterfeiting technologies are difficult to meet the current product safety requirements. Most of the current mainstream anti-counterfeiting means of aluminum foil paper rely on printing specific patterns, using text or laser markings, but these technologies are easily counterfeited and the anti-counterfeiting effect needs to be improved.

[0003] In recent years, magnetic anti-counterfeiting technology has gradually been introduced into the field of anti-counterfeiting of aluminum foil paper. By coating a magnetic material-containing coating on the surface of the aluminum foil paper and using a magnetic detection device to identify magnetic signals, the anti-counterfeiting level can be effectively improved. However, due to the general availability of magnetic materials, a single magnetic anti-counterfeiting technology still has the defect of being easily counterfeited. And currently, the adhesion of the coating with magnetic materials is not strong, and the binding ability with the substrate surface is poor. Therefore, under long-term use or harsh environments, the coating is easy to peel off, resulting in the loss of the anti-counterfeiting effect, and the short anti-counterfeiting timeliness will seriously shorten the service life of the anti-counterfeiting aluminum foil paper. Summary of the Invention

[0004] The purpose of the present invention is to provide a magnetic anti-counterfeiting aluminum foil paper and a preparation process thereof, which solve the following technical problems: (1) the problem that ordinary magnetic anti-counterfeiting aluminum foil paper is easily counterfeited relying only on magnetic detection; (2) the problem that the adhesion between the magnetic coating part of ordinary magnetic anti-counterfeiting aluminum foil paper and the substrate is not strong, resulting in general anti-counterfeiting timeliness and short service life of the magnetic anti-counterfeiting aluminum foil paper.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A magnetic anti-counterfeiting aluminum foil paper is composed of an aluminum foil base paper and an anti-counterfeiting layer on its surface; the anti-counterfeiting layer is obtained by curing a double anti-counterfeiting coating; the double anti-counterfeiting coating includes a first component and a second component; the first component includes the following raw materials in parts by weight: 60 - 80 parts of bisphenol A epoxy resin, 12 - 15 parts of magnetic nano-Fe3O4, 5 - 8 parts of temperature-controlled color-changing microcapsules, 100 - 120 parts of deionized water, 3 - 5 parts of silane coupling agent, 2 - 3 parts of dispersant; the second component includes the following raw materials in parts by weight: 20 - 30 parts of adhesion curing agent, 1 - 2 parts of dimethyl silicone oil, 2 - 3 parts of antioxidant, 50 - 80 parts of deionized water.

[0007] Further, the silane coupling agent is any one of silane coupling agent KH-550, silane coupling agent KH-560, and silane coupling agent KH-570; the dispersant is any one of sodium polyacrylate, sodium oleate, and sodium dodecylbenzenesulfonate; the antioxidant is any one of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and 3,5-di-tert-butyl-4-hydroxybenzoic acid.

[0008] Further, the preparation method of the magnetic nano-Fe3O4 includes the following steps:

[0009] Add FeCl3·6H2O and FeSO4·7H2O into deionized water, disperse them by magnetic stirring, place them in a constant temperature water bath, continuously introduce nitrogen, dropwise add ammonia water under stirring to adjust the pH to 10-10.5, continue stirring for 2-2.5 h after completion, stop the reaction after the solution becomes a black suspension, perform magnetic separation operation on the reaction solution, collect the black precipitate, and obtain magnetic nano-Fe3O4 after washing and drying.

[0010] Further, the mass ratio of FeCl3·6H2O, FeSO4·7H2O to deionized water is 8-12:4-6:180-220.

[0011] In this solution, through the redox reaction of ferric ions and ferrous ions under alkaline conditions and nitrogen atmosphere, magnetic nano-Fe3O4 is co-precipitated. Adding it to the preparation process of the double anti-counterfeiting coating endows the double anti-counterfeiting coating with magnetic response characteristics, enabling the prepared aluminum foil paper to generate specific signals under the action of magnetic detection equipment, forming a recognizable magnetic coating, thereby enhancing the anti-counterfeiting ability of the aluminum foil paper. At the same time, magnetic nano-Fe3O4 has chemical inertness, which can effectively improve the stability of the anti-counterfeiting layer and enable it to exert a long-term anti-counterfeiting effect.

[0012] Further, the temperature of the constant temperature water bath is 80-85 °C.

[0013] Further, the preparation method of the temperature-controlled color-changing microcapsule includes the following steps:

[0014] S1: Heat cholesteryl benzoate to melting, fully stir to form a core material melt; add Span-80 and mix it fully, place it in deionized water at 60-65 °C, and perform shear treatment to form an emulsion for standby;

[0015] S2: Place gelatin and xanthan gum in deionized water respectively, heat to 50-55 °C and stir evenly, and form a composite colloid solution after mixing;

[0016] S3: Add the emulsion to the composite colloid solution, mix and stir at 50 - 55 °C, adjust the pH to 4 - 4.5 by dropping dilute hydrochloric acid with a concentration of 1 - 1.5 mol / L, cool down to 10 - 12 °C, add glutaraldehyde and stir for 2 - 3 h. After completion, filter, wash, and dry to obtain the temperature-controlled color-changing microcapsules.

[0017] Further, in step S1, the mass ratio of cholesteryl benzoate, Span-80 to deionized water is 2 - 4:1 - 3:20 - 50.

[0018] Further, in step S2, the mass ratio of gelatin, xanthan gum to deionized water is 3 - 6:3 - 7:70 - 90.

[0019] Further, in step S3, the glutaraldehyde accounts for 0.4 - 0.8% of the total mass of the composite colloid solution.

[0020] In this scheme, cholesteryl benzoate is heated to melting to form a core material melt, which is emulsified to form an emulsion and used as the microcapsule core material. The core material and the wall material formed by the composite colloid solution of gelatin and xanthan gum are compounded by the complex coacervation method, and cross-linked with glutaraldehyde to obtain the temperature-controlled color-changing microcapsules. The core material of this kind of temperature-controlled color-changing microcapsule is cholesteryl benzoate, which has the ability of liquid crystal phase transition. It can trigger the change of liquid crystal pitch and reflect red light at 60 - 80 °C. At the same time, the wall material used is the composite colloid of gelatin and xanthan gum, which has certain light transmittance. When the temperature rises, external observers can intuitively see the color change. The microcapsule shell layer can protect the core material and effectively extend the service life of the core material. When used together with magnetic nano-Fe3O4 in the preparation process of the double anti-counterfeiting coating, the prepared anti-counterfeiting aluminum foil paper can have a double anti-counterfeiting mechanism, and the anti-counterfeiting effect is stable and long-lasting, greatly extending the service life of the anti-counterfeiting aluminum foil paper.

[0021] Further, in step S1, the rate of the shearing treatment is 1000 - 1500 rpm / min, and the time is 10 - 15 min.

[0022] Further, the preparation method of the adhesion curing agent includes the following steps:

[0023] SS1: Place polyethylene glycol and L-cysteine in toluene, fully mix them, add p-toluenesulfonic acid, heat up to 90 - 95 °C and react for 5 - 6 h. After reduced pressure distillation, collect the product to obtain modified polyethylene glycol;

[0024] SS2: Place the modified polyethylene glycol in N,N-dimethylformamide, fully mix and stir it, add 3-methacryloyldopamine and a catalyst, heat up to 60 - 70 °C and react for 3 - 5 h. After reduced pressure distillation, collect the product to obtain the adhesion curing agent.

[0025] Further, in step SS1, the mass ratio of polyethylene glycol, L-cysteine, toluene and p-toluenesulfonic acid is 2-4:2.5-3:70-90:0.4-0.8.

[0026] Further, in step SS2, the mass ratio of the modified polyethylene glycol, N,N-dimethylformamide, 3-methacryloyldopamine and the catalyst is 3.4-3.8:90-110:3-3.4:0.2-0.5.

[0027] In this solution, under the action of p-toluenesulfonic acid, the hydroxyl groups at both ends of the polyethylene glycol structure react with the carboxyl groups in the L-cysteine structure to obtain modified polyethylene glycol. Then, under the action of a catalyst, the amino groups in the modified polyethylene glycol structure react with the alkenyl groups in the 3-methacryloyldopamine structure through Michael addition reaction to obtain an adhesive curing agent with mercapto groups at both ends. This adhesive curing agent can crosslink with the matrix epoxy resin in the double anti-counterfeiting coating to promote the curing and film formation of the coating, and a anti-counterfeiting layer is prepared. At the same time, a large number of ether bonds in its structure can effectively enhance the flexibility of the coating molecular chain, enabling it to better adapt to the surface topography of the substrate and improve the adhesion ability. And the structure of this adhesive curing agent also contains catechol structure, which can form hydrogen bonds with the surface of the aluminum foil paper base paper and can also form coordination bonds with the aluminum ions on the surface, and produce a synergistic effect with the ether bonds, significantly enhancing the adhesion ability between the anti-counterfeiting layer and the aluminum foil paper base paper, so that the prepared anti-counterfeiting aluminum foil paper can exert a long-term anti-counterfeiting effect and significantly extend its service life.

[0028] Further, in step SS2, the catalyst is triethylamine.

[0029] Further, the preparation method of the double anti-counterfeiting coating includes the following steps:

[0030] Step 1: Mix bisphenol A epoxy resin, magnetic nano-Fe3O4, temperature-controlled color-changing microcapsules and deionized water, and after ultrasonic dispersion for 30-45 min, add a silane coupling agent and a dispersant, and stir well at a rotation speed of 200-300 r / min for 2-3 h to obtain the first component of the double anti-counterfeiting coating;

[0031] Step 2: Mix the adhesive curing agent, dimethyl silicone oil, antioxidant and deionized water, and stir well at a rotation speed of 150-250 r / min for 1-1.5 h to obtain the second component of the double anti-counterfeiting coating.

[0032] A preparation process of a magnetic anti-counterfeiting aluminum foil paper includes the following steps:

[0033] Step 1: Mix the first component and the second component of the double anti-counterfeiting coating evenly, and coat it on the surface of the aluminum foil paper base paper by roll coating method, controlling the coating thickness to be 20-25μm to obtain the precursor of the magnetic anti-counterfeiting aluminum foil paper;

[0034] Step 2: Cure the precursor of the magnetic anti-counterfeiting aluminum foil paper at room temperature for 3-5h to form an anti-counterfeiting layer, and obtain the magnetic anti-counterfeiting aluminum foil paper.

[0035] The beneficial effects of the present invention:

[0036] In the present invention, magnetic nano-Fe3O4, temperature-controlled color-changing microcapsules, and an adhesion curing agent are prepared and involved in the preparation process of the double anti-counterfeiting coating. When used as the anti-counterfeiting layer of the magnetic anti-counterfeiting aluminum foil paper, the prepared magnetic anti-counterfeiting aluminum foil paper can have double anti-counterfeiting properties of magnetism and temperature change, and the anti-counterfeiting effect lasts for a long time, greatly enhancing the service life of the magnetic anti-counterfeiting aluminum foil paper, so that it can meet the usage requirements of various fields.

[0037] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. Description of the drawings

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 It is the process flow chart of the preparation of the magnetic anti-counterfeiting aluminum foil paper of the present invention. Specific embodiments

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0041] The preparation methods of magnetic nano-Fe3O4, temperature-controlled color-changing microcapsules, and an adhesion curing agent in the following embodiments and comparative examples of the present invention are as follows:

[0042] I. Preparation of magnetic nano-Fe3O4

[0043] 10 g of FeCl3·6H2O and 5 g of FeSO4·7H2O were added to 200 ml of deionized water. After magnetic stirring and dispersion, the mixture was placed in a constant temperature water bath at 82 °C, and nitrogen was continuously introduced. While stirring, ammonia water was added dropwise to adjust the pH to 10.2. After completion, stirring was continued for 2.3 h. The reaction was stopped after the solution turned into a black suspension. The reaction solution was subjected to magnetic separation operation, and the black precipitate was collected. After washing and drying, magnetic nano-Fe3O4 was obtained.

[0044] II. Preparation of temperature-controlled color-changing microcapsules

[0045] S1: 3 g of cholesteryl benzoate was heated to melting, and after sufficient stirring, a core material melt was formed; 2 g of Span-80 was added and mixed well with it. The mixture was placed in 35 ml of deionized water at 62 °C, and shearing treatment was carried out at a rate of 1200 rpm for 12 min to form an emulsion for standby;

[0046] S2: 5 g of gelatin and 5 g of xanthan gum were respectively placed in 80 ml of deionized water, heated to 52 °C and stirred evenly. After mixing, a composite colloid solution was formed;

[0047] S3: The emulsion was added to the composite colloid solution, and the mixture was stirred at 53 °C. Dilute hydrochloric acid with a concentration of 1.2 mol / L was added dropwise to adjust the pH to 4.2. The temperature was lowered to 11 °C, 0.6 g of glutaraldehyde was added and stirred for 2.5 h. After completion, filtration, washing and drying were carried out to obtain temperature-controlled color-changing microcapsules.

[0048] III. Preparation of adhesion curing agent

[0049] SS1: 3 g of polyethylene glycol and 2.8 g of L-cysteine were placed in 80 ml of toluene. After sufficient mixing, 0.6 g of p-toluenesulfonic acid was added, and the temperature was raised to 92 °C for reaction for 5.5 h. After reduced pressure distillation, the product was collected to obtain modified polyethylene glycol;

[0050] SS2: 3.6 g of modified polyethylene glycol was placed in 100 ml of N,N-dimethylformamide. After sufficient mixing and stirring, 3.2 g of 3-methacryloyldopamine and 0.3 g of triethylamine were added, and the temperature was raised to 65 °C for reaction for 4 h. After reduced pressure distillation, the product was collected to obtain an adhesion curing agent.

[0051] Example 1

[0052] Preparation of double anti-counterfeiting coating

[0053] Step 1: 60 parts of bisphenol A epoxy resin, 12 parts of magnetic nano-Fe3O4, 5 parts of temperature-controlled color-changing microcapsules and 100 parts of deionized water were mixed. After ultrasonic dispersion for 30 min, 3 parts of silane coupling agent KH-550 and 2 parts of sodium polyacrylate were added, and the mixture was sufficiently stirred at a rotation speed of 200 r / min for 2 h to obtain the first component of the double anti-counterfeiting coating;

[0054] Step 2: Mix 20 parts of the adhesion curing agent, 1 part of dimethyl silicone oil, 2 parts of 3,5 - di - tert - butyl - 4 - hydroxybenzyl alcohol with 50 parts of deionized water, and stir well at a rotation speed of 150 r / min for 1 h to obtain the second component of the double - anti - counterfeiting coating.

[0055] Example 2

[0056] Preparation of the double - anti - counterfeiting coating

[0057] Step 1: Mix 70 parts of bisphenol A epoxy resin, 13 parts of magnetic nano - Fe3O4, 7 parts of temperature - controlled color - changing microcapsules with 110 parts of deionized water. After ultrasonic dispersion for 38 min, add 4 parts of silane coupling agent KH - 560 and 2.5 parts of sodium oleate, and stir well at a rotation speed of 250 r / min for 2.5 h to obtain the first component of the double - anti - counterfeiting coating;

[0058] Step 2: Mix 25 parts of the adhesion curing agent, 1.5 parts of dimethyl silicone oil, 2.5 parts of 3,5 - di - tert - butyl - 4 - hydroxybenzyl alcohol with 65 parts of deionized water, and stir well at a rotation speed of 200 r / min for 1.2 h to obtain the second component of the double - anti - counterfeiting coating.

[0059] Example 3

[0060] Preparation of the double - anti - counterfeiting coating

[0061] Step 1: Mix 80 parts of bisphenol A epoxy resin, 15 parts of magnetic nano - Fe3O4, 8 parts of temperature - controlled color - changing microcapsules with 120 parts of deionized water. After ultrasonic dispersion for 45 min, add 5 parts of silane coupling agent KH - 570 and 3 parts of sodium dodecylbenzenesulfonate, and stir well at a rotation speed of 300 r / min for 3 h to obtain the first component of the double - anti - counterfeiting coating;

[0062] Step 2: Mix 30 parts of the adhesion curing agent, 2 parts of dimethyl silicone oil, 3 parts of 3,5 - di - tert - butyl - 4 - hydroxybenzoic acid with 80 parts of deionized water, and stir well at a rotation speed of 250 r / min for 1.5 h to obtain the second component of the double - anti - counterfeiting coating.

[0063] Comparative Example 1

[0064] Preparation of the double - anti - counterfeiting coating

[0065] Step 1: Mix 70 parts of bisphenol A epoxy resin, 7 parts of temperature - controlled color - changing microcapsules with 110 parts of deionized water. After ultrasonic dispersion for 38 min, add 4 parts of silane coupling agent KH - 560 and 2.5 parts of sodium oleate, and stir well at a rotation speed of 250 r / min for 2.5 h to obtain the first component of the double - anti - counterfeiting coating;

[0066] Step 2: Mix 25 parts of adhesion curing agent, 1.5 parts of dimethyl silicone oil, 2.5 parts of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol with 65 parts of deionized water, and stir thoroughly for 1.2 h at a rotation speed of 200 r / min to obtain the second component of the dual anti-counterfeiting coating.

[0067] Comparative Example 2

[0068] Preparation of Dual Anti-counterfeiting Coating

[0069] Step 1: Mix 70 parts of bisphenol A epoxy resin, 13 parts of magnetic nano-Fe3O4 and 110 parts of deionized water, after ultrasonic dispersion for 38 min, add 4 parts of silane coupling agent KH-560, 2.5 parts of sodium oleate, and stir thoroughly for 2.5 h at a rotation speed of 250 r / min to obtain the first component of the dual anti-counterfeiting coating;

[0070] Step 2: Mix 25 parts of adhesion curing agent, 1.5 parts of dimethyl silicone oil, 2.5 parts of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol with 65 parts of deionized water, and stir thoroughly for 1.2 h at a rotation speed of 200 r / min to obtain the second component of the dual anti-counterfeiting coating.

[0071] Comparative Example 3

[0072] Preparation of Dual Anti-counterfeiting Coating

[0073] Step 1: Mix 70 parts of bisphenol A epoxy resin, 13 parts of magnetic nano-Fe3O4, 7 parts of cholesteryl benzoate and 110 parts of deionized water, after ultrasonic dispersion for 38 min, add 4 parts of silane coupling agent KH-560, 2.5 parts of sodium oleate, and stir thoroughly for 2.5 h at a rotation speed of 250 r / min to obtain the first component of the dual anti-counterfeiting coating;

[0074] Step 2: Mix 25 parts of adhesion curing agent, 1.5 parts of dimethyl silicone oil, 2.5 parts of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol with 65 parts of deionized water, and stir thoroughly for 1.2 h at a rotation speed of 200 r / min to obtain the second component of the dual anti-counterfeiting coating.

[0075] Comparative Example 4

[0076] Preparation of Dual Anti-counterfeiting Coating

[0077] Step 1: Mix 70 parts of bisphenol A epoxy resin, 13 parts of magnetic nano-Fe3O4, 7 parts of temperature-controlled color-changing microcapsules and 110 parts of deionized water, after ultrasonic dispersion for 38 min, add 4 parts of silane coupling agent KH-560, 2.5 parts of sodium oleate, and stir thoroughly for 2.5 h at a rotation speed of 250 r / min to obtain the first component of the dual anti-counterfeiting coating;

[0078] Step 2: Mix 25 parts of modified polyethylene glycol, 1.5 parts of dimethyl silicone oil, 2.5 parts of 3,5 - di - tert - butyl - 4 - hydroxybenzyl alcohol with 65 parts of deionized water, and stir thoroughly at a speed of 200 r / min for 1.2 h to obtain the second component of the double - anti - counterfeiting coating.

[0079] Performance testing

[0080] Mix the first component and the second component of the double - anti - counterfeiting coatings prepared in Examples 1 - 3 and Comparative Examples 1 - 4 evenly, coat them on the surface of a qualified aluminum foil substrate, and after curing at room temperature for 3 h, refer to the standard GB / T5210 - 2006 to detect the adhesion of the samples; use a vibrating sample magnetometer to test the magnetic saturation of the samples to judge the magnetic anti - counterfeiting ability of the samples; use a hot air gun to heat the samples to 70 °C to observe whether the color development on the surface of the samples is clear, and observe whether the color fades after cooling. One heating and subsequent cooling is one cycle. After 100 cycles, record the number of cycles completed by the samples to judge the temperature - change anti - counterfeiting ability of the samples. The specific test results are shown in the following table:

[0081]

[0082]

[0083] As can be seen from the above table, the samples prepared in Examples 1 - 3 all have excellent adhesion ability, magnetic anti - counterfeiting ability, and temperature - change anti - counterfeiting ability. In the sample prepared in Comparative Example 1, magnetic nano - Fe3O4 was not added, so it does not have magnetic anti - counterfeiting ability. In the sample prepared in Comparative Example 2, temperature - controlled color - changing microcapsules were not added, so it does not have temperature - change anti - counterfeiting ability. In the sample prepared in Comparative Example 3, cholesteryl benzoate was directly added, which has temperature - change anti - counterfeiting ability but the number of cycles is less than that of the examples, and the anti - counterfeiting timeliness is shorter. In the sample prepared in Comparative Example 4, modified polyethylene glycol was directly added as a curing agent. Due to the lack of catechol structure in its structure, its adhesion ability is inferior to that of the examples.

[0084] Use the double - anti - counterfeiting coatings prepared in Examples 1 - 3 to prepare magnetic anti - counterfeiting aluminum foil paper respectively. The specific preparation process includes the following steps:

[0085] ① Mix the first component and the second component of the double - anti - counterfeiting coating evenly, and use the roll - coating method to coat it on the surface of the aluminum foil layer, controlling the coating thickness to be 23 μm to obtain the precursor of the magnetic anti - counterfeiting aluminum foil paper;

[0086] ② Cure the precursor of the magnetic anti - counterfeiting aluminum foil paper at room temperature for 4 h to form an anti - counterfeiting layer, and obtain the magnetic anti - counterfeiting aluminum foil paper.

[0087] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0088] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the specific embodiments described or use similar methods for substitution, as long as they do not deviate from the scope defined by the concept of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A magnetic anti-counterfeiting aluminum foil paper, characterized in that, It consists of two parts: an aluminum foil base paper and an anti-counterfeiting layer on its surface; the anti-counterfeiting layer is obtained after curing a double anti-counterfeiting coating; the double anti-counterfeiting coating includes a first component and a second component; the first component includes the following raw materials in parts by weight: 60-80 parts of bisphenol A epoxy resin, 12-15 parts of magnetic nano Fe3O4, 5-8 parts of temperature-controlled color-changing microcapsules, 100-120 parts of deionized water, 3-5 parts of silane coupling agent, 2-3 parts of dispersant; the second component includes the following raw materials in parts by weight: 20-30 parts of adhesion curing agent, 1-2 parts of dimethyl silicone oil, 2-3 parts of antioxidant, 50-80 parts of deionized water.

2. The magnetic anti-counterfeiting aluminum foil paper according to claim 1, characterized in that, The silane coupling agent is any one of silane coupling agent KH-550, silane coupling agent KH-560, and silane coupling agent KH-570; the dispersant is any one of sodium polyacrylate, sodium oleate, and sodium dodecylbenzenesulfonate; the antioxidant is any one of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and 3,5-di-tert-butyl-4-hydroxybenzoic acid.

3. A magnetic anti-counterfeiting aluminum foil paper according to claim 1, characterized in that, The preparation method of the magnetic nano Fe3O4 includes the following steps: Add FeCl3·6H2O and FeSO4·7H2O to deionized water, disperse them by magnetic stirring, place them in a constant temperature water bath, continuously introduce nitrogen, dropwise add ammonia water under stirring to adjust the pH to 10-10.5, continue stirring for 2-2.5 h after completion, stop the reaction after the solution becomes a black suspension, perform magnetic separation on the reaction solution, collect the black precipitate, and obtain magnetic nano Fe3O4 after washing and drying.

4. The magnetic anti-counterfeiting aluminum foil paper according to claim 3, characterized in that, The temperature of the constant temperature water bath is 80-85 °C.

5. A magnetic anti-counterfeiting aluminum foil paper according to claim 1, characterized in that, The preparation method of the temperature-controlled color-changing microcapsules includes the following steps: S1: Heat cholesteryl benzoate to melting, stir well to form a core material melt; add Span-80 and mix well with it, place it in deionized water at 60-65 °C, and perform shear treatment to form an emulsion for standby; S2: Place gelatin and xanthan gum in deionized water respectively, heat to 50-55 °C and stir evenly, and form a composite colloid solution after mixing; S3: Add the emulsion to the composite colloid solution, mix and stir at 50-55 °C, dropwise add dilute hydrochloric acid with a concentration of 1-1.5 mol / L to adjust the pH to 4-4.5, cool down to 10-12 °C, add glutaraldehyde and stir for 2-3 h, and obtain temperature-controlled color-changing microcapsules after filtration, washing and drying.

6. The magnetic anti-counterfeiting aluminum foil paper according to claim 5, characterized in that, In step S1, the rate of the shear treatment is 1000-1500 rpm / min, and the time is 10-15 min.

7. A magnetic anti-counterfeiting aluminum foil paper according to claim 1, characterized in that, The preparation method of the adhesion curing agent includes the following steps: SS1: Place polyethylene glycol and L-cysteine in toluene, mix well, add p-toluenesulfonic acid, heat to 90-95 °C and react for 5-6 h, perform vacuum distillation, and collect the product to obtain modified polyethylene glycol; SS2: Place the modified polyethylene glycol in N,N-dimethylformamide, mix and stir well, add 3-methacryloyldopamine and a catalyst, heat to 60-70 °C and react for 3-5 h, perform vacuum distillation and collect the product to obtain the adhesion curing agent.

8. A magnetic anti-counterfeiting aluminum foil paper according to claim 7, characterized in that, In step SS2, the catalyst is triethylamine.

9. The magnetic anti-counterfeiting aluminum foil paper according to claim 1, characterized in that, The preparation method of the double anti-counterfeiting coating comprises the following steps: Step 1: Mix bisphenol A epoxy resin, magnetic nano-Fe3O4, temperature-controlled color-changing microcapsules and deionized water, and after ultrasonic dispersion for 30 - 45 min, add a silane coupling agent and a dispersant, and stir thoroughly at a rotation speed of 200 - 300 r / min for 2 - 3 h to obtain the first component of the double anti-counterfeiting coating; Step 2: Mix an adhesion curing agent, dimethyl silicone oil, an antioxidant and deionized water, and stir thoroughly at a rotation speed of 150 - 250 r / min for 1 - 1.5 h to obtain the second component of the double anti-counterfeiting coating.

10. A preparation process of the magnetic anti-counterfeiting aluminum foil paper as described in claim 1, characterized in that, Comprises the following steps: Step 1: Mix the first component and the second component of the double anti-counterfeiting coating evenly, and use the roller coating method to coat the surface of the aluminum foil paper base paper, and control the coating thickness to be 20 - 25 μm to obtain a magnetic anti-counterfeiting aluminum foil paper precursor; Step 2: Cure the magnetic anti-counterfeiting aluminum foil paper precursor at room temperature for 3 - 5 h to form an anti-counterfeiting layer, and obtain the magnetic anti-counterfeiting aluminum foil paper.

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