Anti-forgery ink and preparation method thereof

Abstract

The invention provides anti-forgery ink and a preparation method thereof. The anti-forgery ink comprises the following components in parts by weight: 25-40 parts of graphene quantum dots loaded with ionic liquid, 1-4 parts of a surfactant, 30-45 parts of epoxy acrylic resin, 5-15 parts of an adhesive and 80-110 parts of an organic solvent, the graphene quantum dot loaded with the ionic liquid is prepared by performing thermal reduction reaction on a carbon nano tube, graphene oxide and the ionic liquid and then reacting with perchloric acid. The prepared anti-forgery ink is moderate in viscosity, the retention rate of fluorescence intensity is high after the anti-forgery ink is placed in hot water of 80 DEG C, ultraviolet lamp irradiation and the extreme environment of ethyl alcohol for 10 h, especially light resistance, ethyl alcohol resistance and the retention rate of the fluorescence intensity can reach 86% or above, and the anti-forgery ink has good fluorescence stability.

Description

Technical Field

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

[0002] Anti-counterfeiting ink is a special ink that achieves the purpose of anti-counterfeiting by adding colorants and binders with special functions. The use of fluorescent anti-counterfeiting is currently a widely used anti-counterfeiting technology with the advantages of low cost, good concealment, and easy color recognition. With the rapid development of nanotechnology, quantum dots have been used in anti-counterfeiting inks. In recent years, with the emergence of fullerenes, graphene, etc., carbon quantum dots have also received widespread attention. As a new quantum dot, carbon quantum dots have significant quantum confinement and marginal effects, and have the advantages of low cytotoxicity and chemical inertness, which has enabled scientific researchers to invest more in the study of synthetic carbon quantum dots. Some studies (Li Yongmei, Xiang Hua, Lin Muxiong, etc.) have found that commercially available fluorescent inks have problems such as a large particle size distribution range and poor concealment. At the same time, the stability of fluorescence is low, and the fluorescence cannot be well maintained under extreme conditions. Therefore, the development of high-quality anti-counterfeiting inks is still an important research topic at present. Summary of the invention

[0003] In view of this, the object of the present invention is to provide an anti-counterfeiting ink and a preparation method thereof.

[0004] The technical solution of the present invention is achieved in this way:

[0005] The present invention provides an anti-counterfeiting ink, comprising the following components in parts by weight: 25 to 40 parts of graphene quantum dots loaded with ionic liquid, 1 to 4 parts of surfactant, 30 to 45 parts of epoxy acrylic resin, 5 to 15 parts of adhesive and 80 to 110 parts of organic solvent;

[0006] The graphene quantum dots loaded with ionic liquid are prepared by subjecting carbon nanotubes, graphene oxide and ionic liquid to a thermal reduction reaction and then reacting with perchloric acid.

[0007] A further solution is to include the following components in parts by weight: 32-38 parts of graphene quantum dots loaded with ionic liquid, 2-4 parts of surfactant, 33-42 parts of epoxy acrylic resin, 8-12 parts of adhesive and 85-100 parts of organic solvent.

[0008] In a further embodiment, the surfactant includes Triton or aluminum stearate, the adhesive includes polyvinyl alcohol or polyethylene glycol, the organic solvent includes ethanol, n-butanol or acetone, and the anti-counterfeiting ink further includes a thickener and a leveling agent.

[0009] A further solution is that the preparation method of the graphene quantum dots loaded with ionic liquid includes: taking carbon nanotubes and graphene oxide, mixing, adding to an ionic liquid aqueous solution, stirring, introducing an inert gas for thermal reduction at 140-160° C. for 20-40 min, adding perchloric acid for reaction at 190-210° C. for 2-3 h, and calcining at 400-500° C. for 2-3 h to obtain graphene quantum dots loaded with ionic liquid.

[0010] In a further embodiment, the ionic liquid includes 1-butyl-3-methylimidazolium chloride or 1-methyl-3-octylimidazolium chloride, and the concentration of the ionic liquid is 0.03-0.06M.

[0011] A further solution is that the mass ratio of the carbon nanotubes and graphene oxide is 1-2:1-2, and the mass volume ratio of the carbon nanotubes and graphene oxide to the ionic liquid aqueous solution and perchloric acid is 1g:8-12mL:50-60mL.

[0012] A further solution is that the concentration of perchloric acid is 1-2M.

[0013] The present invention also provides a method for preparing the anti-counterfeiting ink, comprising the following preparation steps:

[0014] S1: taking graphene quantum dots loaded with ionic liquid, adding them into an organic solvent for ultrasonic dispersion, adding epoxy acrylic resin, surfactant and adhesive after ultrasonic dispersion, stirring to obtain a premixed solution;

[0015] S2: adding a thickener and a leveling agent to the premixed liquid, and shearing the premixed liquid to obtain the anti-counterfeiting ink.

[0016] A further solution is that in step S1, the ultrasonic dispersion is performed at 350-400W for 10-30min; and the stirring is performed at 3500-4500rpm for 20-40min.

[0017] A further solution is that in step S2, the shearing is performed at 5000-7000 rpm for 5-10 min.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The invention uses graphene quantum dots loaded with ionic liquid, surfactant, epoxy acrylic resin, adhesive and organic solvent as raw materials to prepare an anti-counterfeiting ink. The viscosity of the anti-counterfeiting ink is moderate, and after being exposed to 80°C hot water, ultraviolet light and ethanol in extreme environments for 10 hours, the retention rate of fluorescence intensity is high, especially the light resistance and ethanol resistance. The retention rate of fluorescence intensity can reach more than 86%, and the anti-counterfeiting ink has good fluorescence stability.

[0020] The present invention uses carbon nanotubes and graphene oxide as raw materials, prepares graphene quantum dots loaded with ionic liquid by adding ionic liquid aqueous solution, and regulates reaction parameters, which is helpful to adjust the particle size of the graphene quantum dots, and has good fluorescence properties. The graphene quantum dots have good dispersibility after being mixed with connecting materials, etc., and have a large contact area with the connecting materials, etc., and the stability of the anti-counterfeiting ink is greatly improved. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods.

[0023] Unless otherwise specified, the materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources.

[0024] The ionic liquid used in the examples and comparative examples is 1-butyl-3-methylimidazolium chloride.

[0025] Example 1

[0026] The raw materials of anti-counterfeiting ink are as follows:

[0027] Graphene quantum dots 38 parts

[0028] 3 parts of surfactant Triton

[0029] Epoxy acrylic resin 33 parts

[0030] Adhesive polyvinyl alcohol 8 parts

[0031] 85 parts of organic solvent ethanol

[0032] Thickener 1 part

[0033] 1 part of leveling agent

[0034] Carbon nanotubes and graphene oxide in a mass ratio of 1:1 were added to a 0.03M ionic liquid aqueous solution, stirred at 60°C and 200rpm for 20min, nitrogen was introduced, thermal reduction was carried out at 150°C for 30min, 1M perchloric acid solution was added, the temperature was raised to 200°C for reaction for 2h, and calcined at 400°C for 2h to obtain graphene quantum dots loaded with ionic liquid; the mass volume ratio of the carbon nanotube and graphene oxide raw materials, the ionic liquid aqueous solution and the perchloric acid solution was 1g:10mL:60mL.

[0035] Take graphene quantum dots loaded with ionic liquid, add them into anhydrous ethanol and carry out 360W ultrasonic dispersion for 20 minutes, add epoxy acrylic resin, Triton and polyvinyl alcohol, stir at 4000rpm for 30 minutes, add polyacrylic acid thickener and silicone leveling agent H421, shear at 6000rpm for 10 minutes to obtain anti-counterfeiting ink.

[0036] Example 2

[0037] The raw materials of anti-counterfeiting ink are as follows:

[0038] Graphene quantum dots 32 parts

[0039] 3 parts of surfactant Triton

[0040] Epoxy acrylic resin 42 parts

[0041] Adhesive polyvinyl alcohol 12 parts

[0042] 100 parts of organic solvent ethanol

[0043] Thickener 1 part

[0044] 1 part of leveling agent

[0045] Carbon nanotubes and graphene oxide in a mass ratio of 1:1 were added to a 0.03M ionic liquid aqueous solution, stirred at 60°C and 200rpm for 20min, nitrogen was introduced, thermal reduction was carried out at 150°C for 30min, 1M perchloric acid solution was added, the temperature was raised to 200°C for reaction for 2h, and calcined at 400°C for 2h to obtain graphene quantum dots loaded with ionic liquid; the mass volume ratio of the carbon nanotube and graphene oxide raw materials, the ionic liquid aqueous solution and the perchloric acid solution was 1g:10mL:60mL.

[0046] Take graphene quantum dots loaded with ionic liquid, add them into anhydrous ethanol and carry out 360W ultrasonic dispersion for 20 minutes, add epoxy acrylic resin, Triton and polyvinyl alcohol, stir at 4000rpm for 30 minutes, add polyacrylic acid thickener and silicone leveling agent H421, shear at 6000rpm for 10 minutes to obtain anti-counterfeiting ink.

[0047] Example 3

[0048] The raw materials of anti-counterfeiting ink are as follows:

[0049] Graphene quantum dots 28 parts

[0050] 3 parts of surfactant Triton

[0051] Epoxy acrylic resin 42 parts

[0052] Adhesive polyvinyl alcohol 12 parts

[0053] 96 parts of organic solvent ethanol

[0054] Thickener 1 part

[0055] 1 part of leveling agent

[0056] Carbon nanotubes and graphene oxide in a mass ratio of 1:1 were added to a 0.03M ionic liquid aqueous solution, stirred at 60°C and 200rpm for 20min, nitrogen was introduced, thermal reduction was carried out at 150°C for 30min, 1M perchloric acid solution was added, the temperature was raised to 200°C for reaction for 2h, and calcined at 400°C for 2h to obtain graphene quantum dots loaded with ionic liquid; the mass volume ratio of the carbon nanotube and graphene oxide raw materials, the ionic liquid aqueous solution and the perchloric acid solution was 1g:10mL:60mL.

[0057] Take graphene quantum dots loaded with ionic liquid, add them into anhydrous ethanol and carry out 360W ultrasonic dispersion for 20 minutes, add epoxy acrylic resin, Triton and polyvinyl alcohol, stir at 4000rpm for 30 minutes, add polyacrylic acid thickener and silicone leveling agent H421, shear at 6000rpm for 10 minutes to obtain anti-counterfeiting ink.

[0058] Example 4

[0059] The raw materials of anti-counterfeiting ink are as follows:

[0060] Graphene quantum dots 32 parts

[0061] 3 parts of surfactant Triton

[0062] Epoxy acrylic resin 42 parts

[0063] Adhesive polyvinyl alcohol 12 parts

[0064] 100 parts of organic solvent ethanol

[0065] Thickener 1 part

[0066] 1 part of leveling agent

[0067] Carbon nanotubes and graphene oxide in a mass ratio of 1:1 were added to a 0.06M ionic liquid aqueous solution, stirred at 60°C and 200rpm for 20min, nitrogen was introduced, thermal reduction was carried out at 150°C for 30min, 1M perchloric acid solution was added, the temperature was raised to 200°C for reaction for 2h, and calcined at 400°C for 2h to obtain graphene quantum dots loaded with ionic liquid; the mass volume ratio of carbon nanotube and graphene oxide raw materials, ionic liquid aqueous solution and perchloric acid solution was 1g:8mL:50mL.

[0068] Take graphene quantum dots loaded with ionic liquid, add them into anhydrous ethanol and carry out 360W ultrasonic dispersion for 20 minutes, add epoxy acrylic resin, Triton and polyvinyl alcohol, stir at 4000rpm for 30 minutes, add polyacrylic acid thickener and silicone leveling agent H421, shear at 6000rpm for 10 minutes to obtain anti-counterfeiting ink.

[0069] Test example

[0070] The anti-counterfeiting ink prepared in Examples 1 to 4 was printed on wood-free paper using a screen printing plate and dried naturally. Each sample was immersed in hot water at 80°C for 10 hours to test the hot water resistance, immersed in ultraviolet light for 10 hours to test the light resistance, and immersed in anhydrous ethanol for 10 hours to test the ethanol resistance. The fluorescence retention rate was measured compared with the initial fluorescence intensity to characterize the fluorescence stability. The fluorescence was detected using a fluorescence spectrophotometer with an excitation light source of 365nm. The viscosity of the ink was measured using a rotational viscometer. The results are shown in Table 1 below.

[0071] Table 1 Viscosity and fluorescence stability results of anti-counterfeiting inks

[0072]

[0073]

[0074] As can be seen from Table 1 above, the viscosity of the anti-counterfeiting ink of Examples 1 to 4 meets the requirements of GB / T 17001.1-2011 "Anti-counterfeiting ink Part 1: UV-excited fluorescent anti-counterfeiting ink". After 10 hours, the fluorescence stability of the anti-counterfeiting ink under different testing conditions is different, among which the hot water resistance is relatively poor, the light resistance and ethanol resistance are good, and the retention rate of the fluorescence intensity is above 86%, indicating that the graphene quantum dots loaded with ionic liquid prepared by carbon nanotubes, quartz powder, graphene oxide and ionic liquid are scientifically matched with surfactants, epoxy acrylic resins, adhesives, organic solvents, thickeners and leveling agents. The obtained graphene quantum dot ink has moderate viscosity and good fluorescence stability under 80°C hot water, ultraviolet light irradiation and ethanol environment.

[0075] Example 5

[0076] The raw materials of anti-counterfeiting ink are as follows:

[0077] Graphene quantum dots 32 parts

[0078] 3 parts of surfactant Triton

[0079] Epoxy acrylic resin 42 parts

[0080] Adhesive polyvinyl alcohol 12 parts

[0081] 100 parts of organic solvent ethanol

[0082] Thickener 1 part

[0083] 1 part of leveling agent

[0084] Carbon nanotubes and graphene oxide in a mass ratio of 1:1 were added to a 0.05M ionic liquid aqueous solution, stirred at 60°C and 200rpm for 20min, nitrogen was introduced, thermal reduction was carried out at 120°C for 30min, 1M perchloric acid solution was added, the temperature was raised to 180°C for reaction for 2h, and calcined at 400°C for 2h to obtain graphene quantum dots loaded with ionic liquid; the mass volume ratio of the carbon nanotube and graphene oxide raw materials, the ionic liquid aqueous solution and the perchloric acid solution was 1g:10mL:60mL.

[0085] Take graphene quantum dots loaded with ionic liquid, add them into anhydrous ethanol and carry out 360W ultrasonic dispersion for 20 minutes, add epoxy acrylic resin, Triton and polyvinyl alcohol, stir at 4000rpm for 30 minutes, add polyacrylic acid thickener and silicone leveling agent H421, shear at 6000rpm for 10 minutes to obtain anti-counterfeiting ink.

[0086] Comparative Example 1

[0087] The difference between this comparative example and Example 2 is that graphene quantum dots loaded with ionic liquid are not prepared, and the specific steps are as follows:

[0088] The raw materials of anti-counterfeiting ink are as follows:

[0089] Graphene quantum dots 32 parts

[0090] 3 parts of surfactant Triton

[0091] Epoxy acrylic resin 42 parts

[0092] Adhesive polyvinyl alcohol 12 parts

[0093] 100 parts of organic solvent ethanol

[0094] Thickener 1 part

[0095] 1 part of leveling agent

[0096] Take carbon nanotubes and graphene oxide in a mass ratio of 1:1, pass nitrogen, perform thermal reduction at 150°C for 30 min, add 1M perchloric acid solution, raise the temperature to 200°C for reaction for 2 h, and calcine at 400°C for 2 h to obtain graphene quantum dots; the mass volume ratio of carbon nanotubes and graphene oxide raw materials and perchloric acid solution is 1g:60mL.

[0097] Take graphene quantum dots, add them into anhydrous ethanol and carry out 360W ultrasonic dispersion for 20 minutes, add epoxy acrylic resin, Triton and polyvinyl alcohol, stir at 4000rpm for 30 minutes, add polyacrylic acid thickener and silicone leveling agent H421, shear at 6000rpm for 10 minutes to obtain anti-counterfeiting ink.

[0098] Table 2 Viscosity and fluorescence stability results of anti-counterfeiting inks

[0099]

[0100] From Table 2 above, compared with Example 5, the thermal reduction temperature and the reaction temperature are lowered, the particle size of the graphene quantum dots increases, and then the fluorescence stability decreases; compared with Comparative Example 1, the addition of ionic liquid helps to adjust the particle size of the graphene quantum dots. It has been measured that the particle size distribution of the graphene quantum dots in Example 2 is in the range of 5 to 12 nm, the average particle size is 8.3 nm, and it has good fluorescence properties. The graphene quantum dots have good dispersibility after mixing with the connecting material, etc., and the contact area with the connecting material is large, and the stability of the anti-counterfeiting ink is improved.

[0101] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An anti-counterfeiting ink, characterized in that: The invention comprises the following components in parts by weight: 25 to 40 parts of graphene quantum dots loaded with ionic liquid, 1 to 4 parts of surfactant, 30 to 45 parts of epoxy acrylic resin, 5 to 15 parts of adhesive and 80 to 110 parts of organic solvent; The graphene quantum dots loaded with ionic liquid are prepared by subjecting carbon nanotubes, graphene oxide and ionic liquid to a thermal reduction reaction and then reacting with perchloric acid.

2. The anti-counterfeiting ink according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 32 to 38 parts of graphene quantum dots loaded with ionic liquid, 2 to 4 parts of surfactant, 33 to 42 parts of epoxy acrylic resin, 8 to 12 parts of adhesive and 85 to 100 parts of organic solvent.

3. The anti-counterfeiting ink according to claim 1, characterized in that: The surfactant includes Triton or aluminum stearate, the adhesive includes polyvinyl alcohol or polyethylene glycol, the organic solvent includes ethanol, n-butanol or acetone, and the anti-counterfeiting ink further includes a thickener and a leveling agent.

4. An anti-counterfeiting ink according to claim 1 or 2, characterized in that: The preparation method of the graphene quantum dots loaded with ionic liquid comprises: taking carbon nanotubes and graphene oxide, mixing, adding into an ionic liquid aqueous solution, stirring, introducing inert gas for thermal reduction at 140-160° C. for 20-40 min, adding perchloric acid for reaction at 190-210° C. for 2-3 h, and calcining at 400-500° C. for 2-3 h to obtain the graphene quantum dots loaded with ionic liquid.

5. The anti-counterfeiting ink according to claim 4, characterized in that: The ionic liquid includes 1-butyl-3-methylimidazolium chloride or 1-methyl-3-octylimidazolium chloride, and the concentration of the ionic liquid is 0.03-0.06M.

6. The anti-counterfeiting ink according to claim 4, characterized in that: The mass ratio of the carbon nanotubes to graphene oxide is 1-2:1-2, and the mass volume ratio of the carbon nanotubes and graphene oxide to the ionic liquid aqueous solution and perchloric acid is 1g:8-12mL:50-60mL.

7. The anti-counterfeiting ink according to claim 4, characterized in that: The concentration of perchloric acid is 1-2M.

8. The method for preparing an anti-counterfeiting ink according to any one of claims 1 to 7, characterized in that: The method comprises the following preparation steps: S1: taking graphene quantum dots loaded with ionic liquid, adding them into an organic solvent for ultrasonic dispersion, adding epoxy acrylic resin, surfactant and adhesive after ultrasonic dispersion, stirring to obtain a premixed solution; S2: adding a thickener and a leveling agent to the premixed liquid, and shearing the premixed liquid to obtain the anti-counterfeiting ink.

9. The method for preparing an anti-counterfeiting ink according to claim 8, characterized in that: In step S1, the ultrasonic dispersion is performed at 350-400W for 10-30min; and the stirring is performed at 3500-4500rpm for 20-40min.

10. The method for preparing an anti-counterfeiting ink according to claim 8, characterized in that: In step S2, the shearing is performed at 5000-7000 rpm for 5-10 minutes.

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