Near-infrared laser response long afterglow luminescent anti-counterfeit label

Abstract

The utility model discloses a long afterglow luminous silica gel anti-counterfeit label with near-infrared laser response. The anti-counterfeit label comprises a label body, the label body comprises a first silica gel layer and a second silica gel layer which are arranged up and down, a ZnS: Cu, Co long afterglow luminescent material is embedded in the first silica gel layer, and a NaYF4: Yb, Tm up-conversion luminescent material is embedded in the second silica gel layer. The label can continuously emit macroscopic 528nm green long afterglow light after being irradiated by 980nm near-infrared laser for 1s in a dark environment, and the label can be observed for more than 1h in the dark environment. The label emits bright blue-white light under the irradiation of 980nm laser. After the label is irradiated by a fluorescent lamp, macroscopic green long-afterglow luminescence is generated under a dark condition. The label has potential application value in the anti-counterfeit label industry.

Description

Technical Field

[0001] The utility model belongs to the field of luminous anti-counterfeiting labels, and in particular relates to a near-infrared laser responsive long afterglow luminous anti-counterfeiting label. Background Art

[0002] Long afterglow luminescent materials, also known as luminous materials, have certain applications in the field of anti-counterfeiting labels, such as: a composite luminous anti-counterfeiting woven label (CN221057071U), a luminous label (CN217361010U), and an anti-counterfeiting paper card (CN216610629U). Luminous anti-counterfeiting labels can produce long afterglow after being irradiated with ultraviolet light or visible light, and can be observed with the naked eye in dark environments. However, luminous anti-counterfeiting labels cannot be excited by near-infrared lasers in dark environments, and can only be excited by ultraviolet light or visible light. Although luminous anti-counterfeiting labels have a simple structure and are easy to produce, they are also very easy to imitate. Therefore, it is of great significance to prepare advanced optical anti-counterfeiting labels through special composite optical materials and structural design, and realize the near-infrared laser response characteristics that traditional luminous anti-counterfeiting labels do not have, so as to effectively distinguish them from traditional luminous anti-counterfeiting labels and realize new anti-counterfeiting identification strategies. Summary of the invention

[0003] In order to solve the shortcomings and deficiencies of the prior art, the purpose of the utility model is to provide a long afterglow luminous anti-counterfeiting label responsive to near-infrared laser.

[0004] NaYF4:Yb,Tm is a typical ultraviolet-blue light upconversion luminescent material, which can emit ultraviolet light and blue light with peak values ​​of 364nm and 452nm under 980nm laser irradiation. ZnS:Cu,Co is a typical long afterglow luminescent material, which can produce bright green (528nm) long afterglow luminescence after being irradiated with ultraviolet light and blue light. The utility model embeds the upconversion luminescent material NaYF4:Yb,Tm and the long afterglow luminescent material ZnS:Cu,Co in silica gel in sequence, and a long afterglow silica gel sheet responsive to near-infrared laser can be obtained, which has a unique near-infrared laser responsive green long afterglow luminescence property and has great application prospects in the field of advanced luminescent anti-counterfeiting labels.

[0005] The utility model is special in that the anti-counterfeiting label can continuously emit 528nm green long afterglow light visible to the naked eye after being irradiated with 980nm near-infrared laser (500mW) for 1s in a dark environment, and the dark environment can be observed for more than 1h.

[0006] The purpose of the utility model is achieved through the following technical solutions:

[0007] A near-infrared laser responsive long afterglow luminescent anti-counterfeiting label comprises a label body, wherein the label body comprises a first silicone layer and a second silicone layer arranged up and down, the first silicone layer is embedded with a ZnS:Cu,Co long afterglow luminescent material, and the second silicone layer is embedded with a NaYF4:Yb,Tm up-conversion luminescent material.

[0008] Preferably, the ZnS:Cu,Co long afterglow luminescent material and the NaYF4:Yb,Tm up-conversion luminescent material are located in corresponding positions up and down.

[0009] Preferably, the thickness of the first silicone layer is 0.1-0.5 mm.

[0010] Preferably, the thickness of the second silicone layer is 0.1-0.5 mm.

[0011] Preferably, the label body has a length of 2-25 mm and a width of 1-10 mm.

[0012] The ZnS:Cu,Co long afterglow luminescent material can generate bright green (528nm) long afterglow luminescence under the excitation of ultraviolet light and blue light with wavelengths of 364nm and 452nm.

[0013] The NaYF4:Yb,Tm up-conversion luminescent material can emit ultraviolet light and blue light with peak values ​​of 364nm and 452nm under the condition of 980nm laser irradiation.

[0014] Preferably, the near-infrared laser responsive long afterglow luminescent anti-counterfeiting label further comprises an adhesive layer, and the adhesive layer is located below the second silicone layer.

[0015] More preferably, the material of the adhesive layer is a strong pressure-sensitive adhesive layer.

[0016] Preferably, the near-infrared laser responsive long afterglow luminescent anti-counterfeiting label further comprises a release paper layer, and the release paper layer is located below the adhesive layer.

[0017] More preferably, a tearing portion is provided at one end of the release paper layer.

[0018] In the prior art, upconversion materials are also used as advanced anti-counterfeiting labels. For example, a well-known liquor brand has an upconversion luminescent anti-counterfeiting label on its wine bottle. The label can produce green light under the irradiation of the 980nm laser pen included in the liquor packaging. However, the disadvantage is that after the laser is turned off, the green light disappears immediately and cannot be emitted for a long time, which is not conducive to anti-counterfeiting identification during actual use. The utility model combines the NaYF4:Yb, Tm upconversion luminescent label and the ZnS:Cu, Co long afterglow label into one, overcoming the contradictory problem that "near-infrared laser excitation upconversion material produces blue light and ultraviolet light, which is conducive to stimulating the long afterglow luminescence process of the long afterglow material, but at the same time, the near-infrared laser causes the accelerated release of the energy stored in the long afterglow material, resulting in the long afterglow material being unable to smoothly store the energy of blue light and ultraviolet light, and ultimately causing the long afterglow luminescence intensity to weaken or even disappear", and obtains a unique short-time near-infrared excitation-long afterglow luminescence property.

[0019] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0020] Traditional long afterglow anti-counterfeiting labels can only be excited by ultraviolet light, sunlight, and blue light, but cannot be excited by near-infrared lasers to produce afterglow. The utility model combines NaYF4:Yb,Tm upconversion luminescent material and ZnS:Cu,Co long afterglow material into one. In a dark environment, after being irradiated with a 980nm near-infrared laser (500mW) for 1s, it can continuously emit 528nm green long afterglow luminescence visible to the naked eye, and can be observed in a dark environment for more than 1h, thus obtaining a unique short-time near-infrared excitation-long afterglow luminescence property. In addition, it also has the luminescence properties of traditional anti-counterfeiting labels. For example, when the label is irradiated with a 980nm laser, the NaYF4:Yb,Tm upconversion luminescent material emits bright blue-white luminescence; after the label is irradiated with a fluorescent lamp, the ZnS:Cu,Co long afterglow luminescent material produces green long afterglow luminescence visible to the naked eye under dark conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of a long afterglow luminescent anti-counterfeiting label responsive to near-infrared laser, wherein 1 is the label body, 101 is the first silicone layer, 102 is the long afterglow luminescent material ZnS:Cu,Co, 103 is the up-conversion luminescent material NaYF4:Yb,Tm, 104 is the second silicone layer, 2 is the adhesive layer, 3 is the anti-sticking paper layer, and 4 is the tearing part.

[0022] Figure 2 This is the luminescence principle diagram of the long afterglow luminescent anti-counterfeiting label responsive to near-infrared laser.

[0023] Figure 3It is the luminescence spectrum of the up-conversion material NaYF4:Yb,Tm under 980nm laser excitation and the excitation spectrum of the long afterglow material ZnS:Cu,Co at 528nm.

[0024] Figure 4 It is a near-infrared laser responsive long afterglow luminescent anti-counterfeiting label that emits a long afterglow luminescence spectrum after being irradiated with ultraviolet light, blue light and near-infrared laser respectively.

[0025] Figure 5 The luminescence spectra of Example 1 after being irradiated with 365nm ultraviolet light and 980nm near-infrared laser respectively.

[0026] Figure 6 These are the luminescence spectra of Example 2 after being irradiated with 365nm ultraviolet light and 980nm near-infrared laser respectively.

[0027] Figure 7 These are the luminescence spectra of Example 3 after being irradiated with 365nm ultraviolet light and 980nm near-infrared laser respectively. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0029] If no specific conditions are specified in the examples of the present invention, the conventional conditions or the conditions recommended by the manufacturer are used. The raw materials, reagents, etc., which do not specify the manufacturer, are all conventional products that can be purchased from the market.

[0030] Example 1

[0031] The utility model discloses a near-infrared laser responsive long afterglow luminous anti-counterfeiting label. Figure 1 As shown, the label body 1 includes a first silicone layer 101 and a second silicone layer 104 arranged up and down, the first silicone layer 101 is embedded with a ZnS:Cu, Co long afterglow luminescent material 102, and the second silicone layer 104 is embedded with a NaYF4:Yb, Tm up-conversion luminescent material 103; the positions of the ZnS:Cu, Co long afterglow luminescent material and the NaYF4:Yb, Tm up-conversion luminescent material correspond to each other up and down.

[0032] The near-infrared laser responsive long afterglow luminescent anti-counterfeiting label further comprises an adhesive layer 2 , and the adhesive layer 2 is located below the second silicone layer 104 ; the material of the adhesive layer is a strong pressure-sensitive adhesive layer.

[0033] The near-infrared laser responsive long afterglow luminescent anti-counterfeiting label further comprises a release paper layer 3 , and the release paper layer 3 is located below the adhesive layer 2 .

[0034] One end of the anti-adhesive paper layer 3 is provided with a tearing portion 4 .

[0035] The luminous principle of the anti-counterfeiting label designed in this utility model is shown in Figure 2 The upconversion material NaYF4:Yb,Tm can emit 364nm, 452nm ultraviolet and blue light under 980nm near-infrared laser irradiation. These luminescence overlaps with the excitation spectrum of the long afterglow material ZnS:Cu,Co ( Figure 3 ), so as to effectively stimulate its long afterglow luminescence. As an example, the preparation method of the label body is: first, 0.7g of up-conversion material NaYF4:Yb, Tm powder and 1mL of thermosetting silicone liquid are mixed and stirred evenly, poured into a rectangular plastic mold, and heated in an oven at 100°C for 30 minutes to solidify the silicone to obtain a second silicone layer with a thickness of about 0.5mm and embedded with NaYF4:Yb, Tm up-conversion luminescent material. Then, 0.3g of long afterglow material ZnS:Cu, Co powder and 1mL of thermosetting silicone liquid are mixed and stirred evenly, poured on the second silicone layer, and heated in an oven at 100°C for 30 minutes to solidify the silicone to obtain a thin sheet with a thickness of about 1mm, which is cut into any shape, such as a rectangular sheet of 10mm*25mm*1mm, to obtain a long afterglow luminescent anti-counterfeiting label body that responds to near-infrared lasers. After being irradiated with ultraviolet light, blue light and near-infrared lasers, the label body can emit long afterglow luminescence with a peak at 528nm ( Figure 4 ).

[0036] Comparative Example 1

[0037] As a counter-example, another commercial long afterglow material CaAl2O4:Eu,Nd was used instead of ZnS:Cu,Co to prepare an anti-counterfeiting label using the same preparation process as Example 1. The label can emit long afterglow luminescence with a peak value of 445nm after irradiation with ultraviolet light, but cannot produce obvious long afterglow luminescence after irradiation with 980nm laser ( Figure 5 ).

[0038] Comparative Example 2

[0039] As a counter-example, another commercial long afterglow material Sr2MgSi2O7:Eu,Dy was used instead of ZnS:Cu,Co to prepare an anti-counterfeiting label using the same preparation process as in Example 1. The label can emit long afterglow luminescence with a peak value of 470nm after irradiation with ultraviolet light, but can only produce extremely weak long afterglow luminescence after irradiation with a 980nm laser ( Figure 6 ).

[0040] Comparative Example 3

[0041] As a counter-example, another commercial long afterglow material SrAl2O4:Eu,Dy was used instead of ZnS:Cu,Co to prepare an anti-counterfeiting label using the same preparation process as Example 1. The label can emit long afterglow luminescence with a peak value of 518nm after irradiation with ultraviolet light, but can only produce weak long afterglow luminescence after irradiation with 980nm laser ( Figure 7 ). It can be seen that the combination of ZnS:Cu,Co and NaYF4:Yb,Tm of the utility model can produce near-infrared laser response long afterglow luminescence properties that are significantly better than SrAl2O4:Eu,Dy.

[0042] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A near-infrared laser responsive long afterglow luminescent anti-counterfeiting label, characterized in that: The label body includes a first silicone layer and a second silicone layer arranged up and down, the first silicone layer is embedded with a ZnS:Cu,Co long afterglow luminescent material, and the second silicone layer is embedded with a NaYF4:Yb,Tm up-conversion luminescent material.

2. According to claim 1, a near-infrared laser responsive long afterglow luminescent anti-counterfeiting label, characterized in that: The ZnS:Cu,Co long afterglow luminescent material and the NaYF4:Yb,Tm up-conversion luminescent material are located in corresponding positions.

3. The near-infrared laser responsive long afterglow luminescent anti-counterfeiting label according to claim 1, characterized in that: The thickness of the first silicone layer is 0.1-0.5 mm.

4. The near-infrared laser responsive long afterglow luminescent anti-counterfeiting label according to claim 1, characterized in that: The thickness of the second silicone layer is 0.1-0.5 mm.

5. The near-infrared laser responsive long afterglow luminescent anti-counterfeiting label according to claim 1, characterized in that: The length of the label body is 2-25 mm, and the width is 1-10 mm.

6. The near-infrared laser responsive long afterglow luminescent anti-counterfeiting label according to claim 1, characterized in that: Also included is a bonding layer, which is located below the second silicone layer.

7. The near-infrared laser responsive long afterglow luminescent anti-counterfeiting label according to claim 6, characterized in that: The material of the bonding layer is a strong pressure-sensitive adhesive layer.

8. The near-infrared laser responsive long afterglow luminescent anti-counterfeiting label according to claim 1, characterized in that: Also included is a release paper layer, which is located below the adhesive layer.

9. The near-infrared laser responsive long afterglow luminescent anti-counterfeiting label according to claim 8, characterized in that: One end of the anti-adhesive paper layer is provided with a tearing portion.

Images