Long afterglow anti-counterfeiting leather coating with multiple stimulus responsiveness and preparation method thereof

Abstract

The application discloses a preparation method of a long-afterglow anti-fake leather coating with multiple stimulus responses, and specifically comprises the following steps: step 1, mixing a phosphorescent molecular compound, a layered nanosheet supramolecular assembly and an aqueous polymer emulsion, and then magnetically stirring at room temperature to obtain a long-afterglow anti-fake leather finishing agent with multiple stimulus responses; and step 2, preparing the long-afterglow anti-fake leather coating with multiple stimulus responses according to the product obtained in step 1. The application further discloses the long-afterglow anti-fake leather coating with multiple stimulus responses. The application solves the problems of a complex preparation process, high cost and the inability to realize double anti-fake in the existing anti-fake leather preparation method.

Description

Technical Field

[0001] This invention belongs to the field of anti-counterfeiting leather coating preparation technology, and relates to a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness. This invention also relates to a method for preparing a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness. Background Technology

[0002] Leather finishing not only enhances the aesthetics of leather and conceals surface defects, but also strengthens its durability, meeting the manufacturing needs of various leather products. As the core material for achieving these functions, leather coatings have a decisive impact on the appearance, hygiene, and physical and mechanical properties of leather products. In the leather industry, polyurethane and polyacrylate are common main components of leather coatings. However, with the increasing global consumer market demand for leather products with flame-retardant, antibacterial, anti-counterfeiting, anti-fouling, and self-cleaning properties, traditional leather finishing materials can no longer meet the multifunctional technical requirements of leather products. Therefore, developing new preparation systems to produce high-performance, multifunctional leather coatings has become an urgent priority.

[0003] Currently, patented technologies for the application of anti-counterfeiting leather have been disclosed. For example, Chinese patent (publication number: CN112442562A, application number: 202011483450.2, application date: 2020.12.16) discloses an anti-counterfeiting leather based on perovskite quantum dots and its preparation method. Perovskite quantum dots are prepared by using all-inorganic bismuth-based compounds such as cesium bromide and bismuth bromide, and these nanoscale quantum dots are penetrated into the leather using a vacuum filtration method. Utilizing the luminescent properties of perovskite quantum dots, they display a specific color under ultraviolet light, thereby achieving an anti-counterfeiting effect. Although the method provided in this patent has produced anti-counterfeiting leather with phosphorescent properties, the perovskite quantum dot preparation method is cumbersome and the coating cost is high. Furthermore, it only exhibits fluorescent anti-counterfeiting under ultraviolet light and has not yet achieved multi-level, high-efficiency anti-counterfeiting. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a long-afterglow anti-counterfeiting leather coating with multiple stimulus responses, which solves the problems of complex preparation process, high cost and inability to achieve dual anti-counterfeiting in existing anti-counterfeiting leather preparation methods.

[0005] Another object of the present invention is to provide a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness.

[0006] The first technical solution adopted in this invention is a method for preparing a long-afterglow anti-counterfeiting leather coating with multiple stimulus responses, specifically including the following steps:

[0007] Step 1: After mixing the phosphorescent molecular compound, the layered nanosheet supramolecular assembly and the aqueous polymer emulsion, the mixture is magnetically stirred at room temperature to obtain a long-afterglow anti-counterfeiting leather coating agent with multiple stimulus responses.

[0008] Step 2: Prepare a long-afterglow anti-counterfeiting leather coating with multiple stimulus responsiveness based on the intellectual property obtained in Step 1.

[0009] The first technical solution of this invention is further characterized by:

[0010] In step 1, the phosphorescent molecule compound is any one of 3-amino-N-ethylcarbazole, 5,12-dihydroindolo[3,2-a]carbazole, and 2-(9H-carbazolyl-9-yl)propionic acid.

[0011] In step 1, the aqueous polymer emulsion is a polyurethane or polyacrylate emulsion.

[0012] In step 1, the mass ratio of phosphorescent molecular compound, layered nanosheet supramolecular assembly and aqueous polymer emulsion is 0.001~0.01:0.03~0.15:1.

[0013] In step 1, the magnetic stirring speed is 600-900 rpm.

[0014] The specific process of step 2 is as follows: transfer the leather finishing agent obtained in step 1 into the spray gun, spray it on the leather surface, and finally place the sprayed leather in the oven. After the moisture has completely evaporated, spray it again. Repeat this process 3 times to finally obtain a long-afterglow anti-counterfeiting leather coating with multiple stimuli response.

[0015] In step 2, the leather is any one of vegetable-tanned leather, chrome-tanned leather, or zircon-tanned leather.

[0016] The second technical solution adopted in this invention is a long-afterglow anti-counterfeiting leather coating with multiple stimulus responses, which is prepared by the above-mentioned preparation method of the long-afterglow anti-counterfeiting leather coating with multiple stimulus responses.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. This invention prepares a multi-stimuli-responsive long-afterglow anti-counterfeiting leather coating material by simply blending phosphorescent molecular compounds, layered nanosheet supramolecular assemblies, and polymer emulsions.

[0019] 2. This invention introduces nanosheets into coating materials, which not only enhances the mechanical properties of leather coatings but also endows them with adjustable anti-counterfeiting properties.

[0020] 3. This invention has the advantages of wide availability of materials, simple and effective application methods, and outstanding functions, and is expected to be widely used in the leather coating market. Attached Figure Description

[0021] Figure 1 This is a photograph of the phosphorescence characteristics of the anti-counterfeiting leather coating prepared in Example 1 of the preparation method of the long afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness of the present invention under natural light and 365nm ultraviolet light irradiation.

[0022] Figure 2 This is a photograph of the phosphorescence properties of the anti-counterfeiting leather coating prepared in Example 2 of the preparation method of the long afterglow anti-counterfeiting leather coating with multi-stimulus response of the present invention under natural light and 365nm ultraviolet light irradiation.

[0023] Figure 3 This is a photograph of the phosphorescence characteristics of the anti-counterfeiting leather coating prepared in Example 3 of the preparation method of the long afterglow anti-counterfeiting leather coating with multiple stimulus response of the present invention under natural light and 365nm ultraviolet light irradiation.

[0024] Figure 4 This invention relates to a method for preparing a long-afterglow anti-counterfeiting leather coating with multiple stimulus responses. Example 3 describes the phosphorescence properties of the anti-counterfeiting leather coating prepared under different temperature conditions. Detailed Implementation

[0025] The following detailed description is provided in conjunction with specific implementation methods.

[0026] The present invention discloses a method for preparing a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness, which specifically includes the following steps:

[0027] Step 1: After mixing the phosphorescent molecular compound, the layered nanosheet supramolecular assembly and the aqueous polymer emulsion, the mixture is magnetically stirred at room temperature for 30 minutes at a stirring rate of 600-900 rpm to obtain a long-afterglow anti-counterfeiting leather coating agent with multiple stimulus responses.

[0028] The phosphorescent molecule is any one of 3-amino-N-ethylcarbazole, 5,12-dihydroindolo[3,2-a]carbazole, and 2-(9H-carbazolyl-9-yl)propionic acid;

[0029] Layered nanosheet supramolecular assemblies were prepared by surface functionalization of zirconium phosphate, hydrotalcite, and lithium diatomite with polyphenolic compounds.

[0030] The aqueous polymer emulsion is either a polyurethane or a polyacrylate emulsion.

[0031] The mass ratio of phosphorescent molecular compound, layered nanosheet supramolecular assembly to aqueous polymer emulsion is (0.001~0.01):(0.03~0.15):1.

[0032] Step 2: Transfer the leather finishing agent obtained in Step 1 to a spray gun and spray it onto the leather surface. Finally, place the sprayed leather in a 50℃ oven and spray again after the moisture has completely evaporated. Repeat this process three times, with a total spray volume of 40-70 mL / m². 2 The final product is a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness.

[0033] The leather type can be any one of vegetable-tanned leather, chrome-tanned leather, or zircon-tanned leather.

[0034] Example 1

[0035] 100 mg of 3-amino-N-ethylcarbazole was dissolved in 10 mL of N,N-dimethylformamide solution and stirred at 800 rpm for 10 min at room temperature to prepare a 10 mg / mL 3-amino-N-ethylcarbazole solution for later use. 200 mg of lithium diatomaceous earth layered nanosheets were ultrasonically dispersed in 20 mL of deionized water, followed by the addition of 1 mL of 10 mg / mL gallic acid solution. The mixture was stirred at 500 rpm for 1 h at room temperature to obtain a lithium diatomaceous earth@gallic acid layered nanosheet supramolecular assembly dispersion. Then, 5 mL of 20% solids aqueous polyurethane emulsion, 1 mL of 3-amino-N-ethylcarbazole solution, and 15 mL of the lithium diatomaceous earth@gallic acid supramolecular assembly dispersion were sequentially added to a beaker and stirred at 600 rpm for 15 min at room temperature to obtain a long-afterglow anti-counterfeiting leather coating agent with multi-stimulus responsiveness. The above coating agent is transferred to a spray gun and sprayed evenly once on vegetable-tanned leather. It is then placed in a 50°C oven to dry. This process is repeated three times to obtain a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness.

[0036] Figure 1 These are photographs of the phosphorescence properties of the anti-counterfeiting leather coating prepared in Example 1 under natural light and 365nm ultraviolet (UV) light.

[0037] Figure 1 The image shows vegetable-tanned leather coated with an anti-counterfeiting layer. Under natural light, it appears orange-yellow, while under 365nm ultraviolet light, it exhibits strong blue-violet fluorescence, and even after the ultraviolet light is turned off, it retains a blue afterglow for 3 seconds. The different luminescence colors under natural light and 365nm ultraviolet light conditions demonstrate its excellent anti-counterfeiting effect.

[0038] Example 2

[0039] 100 mg of 2-(9H-carbazolyl-9-yl)propionic acid was dissolved in 10 mL of acetone and stirred at 800 rpm for 10 min at room temperature to prepare a 10 mg / mL 2-(9H-carbazolyl-9-yl)propionic acid solution for later use. 200 mg of hydrotalcite nanosheets were ultrasonically dispersed in 20 mL of deionized water, followed by the addition of 1 mL of a 10 mg / mL polydopamine compound solution. The mixture was stirred at 500 rpm for 1 h at room temperature to obtain a hydrotalcite@polydopamine layered nanosheet supramolecular assembly dispersion. Then, 5 mL of a 20% solids content aqueous polyacrylate emulsion, 0.1 mL of the 2-(9H-carbazolyl-9-yl)propionic acid solution, and 3 mL of the hydrotalcite@polydopamine supramolecular assembly dispersion were sequentially added to a beaker and stirred at 600 rpm for 15 min at room temperature to obtain a long-afterglow anti-counterfeiting leather coating agent with multi-stimulus responsiveness. The above coating agent is transferred to a spray gun and sprayed evenly once on chrome-tanned leather. It is then placed in a 50°C oven to dry. This process is repeated three times to obtain a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness.

[0040] Figure 2 These are photographs of the phosphorescence properties of the anti-counterfeiting leather coating prepared in Example 2 under natural light and 365nm ultraviolet (UV) light. Figure 2 The image shows chrome-tanned leather coated with an anti-counterfeiting layer. Under natural light, it appears as a bluish-green leather, but under 365nm ultraviolet light, it exhibits strong blue fluorescence and retains a blue afterglow for 4 seconds even after the ultraviolet light is turned off. The different luminescence colors under natural light and 365nm ultraviolet light conditions demonstrate its excellent anti-counterfeiting effect.

[0041] Example 3

[0042] 100 mg of 5,12-dihydroindodo[3,2-a]carbazole was dissolved in 10 mL of acetone solution and stirred at 800 rpm for 10 min at room temperature to prepare a 10 mg / mL 5,12-dihydroindodo[3,2-a]carbazole solution for later use. 200 mg of zirconium phosphate layered nanosheets were ultrasonically dispersed in 20 mL of deionized water, followed by the addition of 1 mL of a 10 mg / mL tannic acid solution. The mixture was stirred at 500 rpm for 1 h at room temperature to obtain a zirconium phosphate@tannic acid layered nanosheet supramolecular assembly dispersion. Then, 5 mL of a 20% solids content aqueous polyurethane emulsion, 0.3 mL of the 5,12-dihydroindodo[3,2-a]carbazole solution, and 5 mL of the zirconium phosphate@tannic acid supramolecular assembly dispersion were sequentially added to a beaker and stirred at 900 rpm for 15 min at room temperature to obtain a long-afterglow anti-counterfeiting leather coating agent with multi-stimulus responsiveness. The above coating agent is transferred to a spray gun and sprayed evenly once on zircon-tanned leather. It is then placed in a 50°C oven to dry. This process is repeated three times to obtain a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness.

[0043] Figure 3 These are photographs of the phosphorescence properties of the anti-counterfeiting leather coating prepared in Example 3 under natural light and 365nm ultraviolet (UV) light. Figure 3 The image shows zirconium-tanned leather coated with an anti-counterfeiting layer. Under natural light, it appears as a pale yellow leather, but under 365nm ultraviolet light, it exhibits strong blue fluorescence and retains a 3-second blue afterglow even after the ultraviolet light is turned off. The different luminescence colors under natural light and 365nm ultraviolet light conditions demonstrate its excellent anti-counterfeiting effect.

[0044] Figure 4 The phosphorescence properties of the anti-counterfeiting leather coating prepared in Example 3 under different temperature conditions. Figure 4 The image shows the phosphorescence properties of zirconium tanned leather coated with an anti-counterfeiting coating under different temperature conditions.

[0045] At 25℃, it appears pale blue under 365nm ultraviolet light, with a 3-second blue afterglow.

[0046] At 50℃, it exhibits strong cyan fluorescence under 365nm ultraviolet light irradiation, and shows a blue afterglow for 5 seconds after the ultraviolet light is turned off.

[0047] At 75℃, it exhibits a pale blue fluorescence under 365nm ultraviolet light irradiation, and shows a blue afterglow for 3 seconds after the ultraviolet light is turned off.

[0048] pass Figures 1-4It is known that the leather coating prepared by the present invention exhibits different colors under natural light and 365nm ultraviolet light, and also exhibits different phosphorescence characteristics at different temperatures, thus possessing multi-level anti-counterfeiting performance with dual phosphorescence response.

[0049] Example 4

[0050] 100 mg of 3-amino-N-ethylcarbazole was dissolved in 10 mL of N,N-dimethylformamide solution and stirred at 800 rpm for 10 min at room temperature to prepare a 10 mg / mL 3-amino-N-ethylcarbazole solution for later use. 200 mg of lithium diatomaceous earth layered nanosheets were ultrasonically dispersed in 20 mL of deionized water, followed by the addition of 1 mL of 10 mg / mL gallic acid solution. The mixture was stirred at 500 rpm for 1 h at room temperature to obtain a lithium diatomaceous earth@gallic acid layered nanosheet supramolecular assembly dispersion. Then, 5 mL of 20% solids aqueous polyurethane emulsion, 1 mL of 3-amino-N-ethylcarbazole solution, and 15 mL of the lithium diatomaceous earth@gallic acid supramolecular assembly dispersion were sequentially added to a beaker and stirred at 700 rpm for 15 min at room temperature to obtain a long-afterglow anti-counterfeiting leather coating agent with multi-stimulus responsiveness. The above coating agent is transferred to a spray gun and sprayed evenly once on vegetable-tanned leather. It is then placed in a 50°C oven to dry. This process is repeated three times to obtain a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness.

[0051] Example 5

[0052] 100 mg of 2-(9H-carbazolyl-9-yl)propionic acid was dissolved in 10 mL of acetone and stirred at 800 rpm for 10 min at room temperature to prepare a 10 mg / mL 2-(9H-carbazolyl-9-yl)propionic acid solution for later use. 200 mg of hydrotalcite nanosheets were ultrasonically dispersed in 20 mL of deionized water, followed by the addition of 1 mL of a 10 mg / mL polydopamine compound solution. The mixture was stirred at 500 rpm for 1 h at room temperature to obtain a hydrotalcite@polydopamine layered nanosheet supramolecular assembly dispersion. Then, 5 mL of a 20% solids aqueous polyacrylate emulsion, 0.1 mL of the 2-(9H-carbazolyl-9-yl)propionic acid solution, and 3 mL of the hydrotalcite@polydopamine supramolecular assembly dispersion were sequentially added to a beaker and stirred at 750 rpm for 15 min at room temperature to obtain a long-afterglow anti-counterfeiting leather coating agent with multi-stimulus responsiveness. The above coating agent is transferred to a spray gun and sprayed evenly once on chrome-tanned leather. It is then placed in a 50°C oven to dry. This process is repeated three times to obtain a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness.

[0053] Example 6

[0054] 100 mg of 5,12-dihydroindodo[3,2-a]carbazole was dissolved in 10 mL of acetone solution and stirred at 800 rpm for 10 min at room temperature to prepare a 10 mg / mL 5,12-dihydroindodo[3,2-a]carbazole solution for later use. 200 mg of zirconium phosphate layered nanosheets were ultrasonically dispersed in 20 mL of deionized water, followed by the addition of 1 mL of a 10 mg / mL tannic acid solution. The mixture was stirred at 500 rpm for 1 h at room temperature to obtain a zirconium phosphate@tannic acid layered nanosheet supramolecular assembly dispersion. Then, 5 mL of a 20% solids content aqueous polyurethane emulsion, 0.3 mL of the 5,12-dihydroindodo[3,2-a]carbazole solution, and 5 mL of the zirconium phosphate@tannic acid supramolecular assembly dispersion were sequentially added to a beaker and stirred at 850 rpm for 15 min at room temperature to obtain a long-afterglow anti-counterfeiting leather coating agent with multi-stimulus responsiveness. The above coating agent is transferred to a spray gun and sprayed evenly once on zircon-tanned leather. It is then placed in a 50°C oven to dry. This process is repeated three times to obtain a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness.

Claims

1. A method for preparing a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness, characterized in that: Specifically, the steps include the following: Step 1: The phosphorescent molecular compound, the layered nanosheet supramolecular assembly, and the aqueous polymer emulsion are mixed and magnetically stirred at room temperature to obtain a long-afterglow anti-counterfeiting leather coating agent with multiple stimulus responses; In Step 1, the phosphorescent molecular compound is any one of 3-amino-N-ethylcarbazole, 5,12-dihydroindolo[3,2-a]carbazole, and 2-(9H-carbazolyl-9-yl)propionic acid; The layered nanosheet supramolecular assembly is prepared by surface functionalization of polyphenolic compounds with zirconium phosphate, hydrotalcite, and lithium diatomite. Step 2: Prepare a long-afterglow anti-counterfeiting leather coating with multiple stimulus responsiveness based on the product obtained in Step 1.

2. The method for preparing a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness according to claim 1, characterized in that: In step 1, the aqueous polymer emulsion is a polyurethane or polyacrylate emulsion.

3. The method for preparing a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness according to claim 2, characterized in that: In step 1, the mass ratio of phosphorescent molecular compound, layered nanosheet supramolecular assembly and aqueous polymer emulsion is 0.001~0.01:0.03~0.15:

1.

4. The method for preparing a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness according to claim 3, characterized in that: In step 1, the magnetic stirring speed is 600-900 rpm.

5. The method for preparing a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness according to claim 4, characterized in that: The specific process of step 2 is as follows: the leather coating agent obtained in step 1 is transferred to a spray gun and sprayed on the leather surface. Finally, the sprayed leather is placed in an oven and sprayed again after the moisture has completely evaporated. This process is repeated 3 times to finally obtain a long-afterglow anti-counterfeiting leather coating with multiple stimuli responsiveness.

6. The method for preparing a long-afterglow anti-counterfeiting leather coating with multi-stimulus responsiveness according to claim 5, characterized in that: In step 2, the leather is any one of vegetable-tanned leather, chrome-tanned leather, or zircon-tanned leather.

7. A long-afterglow anti-counterfeiting leather coating with multiple stimulus responsiveness, prepared by the preparation method of the long-afterglow anti-counterfeiting leather coating with multiple stimulus responsiveness as described in any one of claims 1 to 6.

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