Thermal-sensitive anti-counterfeiting ink for high-adhesion and high-water-resistance printing and preparation method thereof

Abstract

The present invention provides a high-adhesion and high-water-resistant heat-sensitive anti-counterfeiting ink for printing, comprising the following components in parts by mass: 30-40 parts of acrylic emulsion, 10-20 parts of polyurethane emulsion, 1-10 parts of bisphenol A epoxy resin, 1-10 parts of thermochromic dye, 1-10 parts of heat-sensitive microcapsules, 1-2 parts of a first coupling agent, 1-2 parts of a second coupling agent, 2-3 parts of a wetting agent, 2-3 parts of a cross-linking agent, 1-5 parts of a fluorine compound modifier, 1-2 parts of methyl silane, 1-10 parts of a wax emulsion, and 1-2 parts of a second coupling agent. ‑2 parts, defoaming agent 0.2‑1 parts, leveling agent 0.5‑1 parts, preservative 0.1‑0.5 parts; wherein, the acrylic emulsion, polyurethane emulsion, first coupling agent and wetting agent are fixed in the network structure formed by the cross-linking agent, and the hydrophobic layer formed by the wax emulsion, and the fluorine compound modifier, second coupling agent, and methyl silane are fixed in the three-dimensional network structure formed by the cured epoxy resin. The fixed components interact with each other, effectively improving the adhesion and water resistance of the ink.

Description

Technical Field

[0001] The present invention relates to the field of anti-counterfeiting technology, and in particular to a heat-sensitive anti-counterfeiting ink for high-adhesion and high-water-resistance printing and a preparation method thereof. Background Art

[0002] Thermal-sensitive anti-counterfeiting ink is a specialized ink designed for anti-counterfeiting purposes. It can reveal or conceal colors or patterns through temperature changes, thereby verifying the authenticity of items. In addition to its thermal color-changing effect, the performance of thermal-sensitive anti-counterfeiting ink also requires attention to its adhesion and water resistance to ensure its effectiveness and durability in actual use.

[0003] Adhesion refers to the ability of ink to adhere to the substrate surface, directly affecting the durability and effectiveness of anti-counterfeiting inks. Water resistance refers to the stability of inks in water or humid environments, particularly in conditions of high humidity or direct contact with water, maintaining their physical and chemical properties. Heat-sensitive anti-counterfeiting inks, in particular, require a certain temperature to achieve their anti-counterfeiting effect, and increasing temperature requires higher adhesion and water resistance.

[0004] In the prior art, the adhesion and water resistance of inks are generally improved by selecting a suitable substrate and adding additives. Although these methods can improve the adhesion and water resistance of inks to a certain extent, the overall improvement effect is limited. Some additives may even fail to truly play a role, resulting in poor final results. Summary of the Invention

[0005] The purpose of the present invention is to address the deficiencies of the existing technology and provide a high-adhesion and high-water-resistant thermal anti-counterfeiting ink for printing and a preparation method thereof. By optimizing the components and processes, the adhesion and water resistance of the ink are improved while ensuring the anti-counterfeiting effect of the ink.

[0006] According to a first aspect of the present invention, there is provided a thermosensitive anti-counterfeiting ink for high-adhesion and high-water resistance printing, comprising the following components in parts by mass: 30-40 parts of acrylic emulsion, 10-20 parts of polyurethane emulsion, 1-10 parts of bisphenol A epoxy resin, 1-10 parts of thermochromic dye, 1-10 parts of thermosensitive microcapsules, 1-2 parts of a first coupling agent, 1-2 parts of a second coupling agent, 2-3 parts of a wetting agent, 2-3 parts of a cross-linking agent, 1-5 parts of a fluorine compound modifier, 1-2 parts of methyl silane, 1-2 parts of a wax emulsion, 0.2-1 parts of a defoaming agent, 0.5-1 parts of a leveling agent, and 0.1-0.5 parts of a preservative.

[0007] Furthermore, the acrylic emulsion is a copolymer of methyl methacrylate and butyl acrylate, and the polyurethane emulsion is a polyurethane emulsion containing a long-chain alkyl group or an aromatic group.

[0008] Furthermore, the polyurethane emulsion is a polyurethane emulsion containing a long-chain alkyl group, and the preparation process is as follows:

[0009] Mix MDI, polyether polyol containing long-chain alkyl, polyhexanediol adipate polyol and cosolvent in a reaction kettle, and stir at 80-90° C. for 2-4 hours to obtain a prepolymer;

[0010] gradually adding the prepolymer into the emulsifier solution to form an emulsion under ultrasonic emulsification conditions;

[0011] Add ethylenediamine to the emulsion and continue stirring at 50-60°C until the reaction is complete;

[0012] The pH of the product after the reaction is adjusted to neutral, and the solvent is removed by distillation under reduced pressure after filtration to obtain a polyurethane emulsion containing a long-chain alkyl group.

[0013] Furthermore, the mass ratio of MDI, the long-chain alkyl-containing polyether polyol and the poly(hexamethylene adipate) polyol is 3:(2.5-3):2, and the mass ratio of ethylenediamine to MDI is 1:6.

[0014] Furthermore, the emulsifier includes a fatty acid salt emulsifier and a silicone emulsifier, wherein the fatty acid salt emulsifier accounts for 5-15% of the prepolymer weight, and the silicone emulsifier accounts for 1-5% of the prepolymer weight.

[0015] Furthermore, the first coupling agent includes γ-aminopropyltriethoxysilane (APTES), and the second coupling agent includes γ-glycidoxypropyltrimethoxysilane (GPTMS).

[0016] Furthermore, the wetting agent includes a glycol ether wetting agent (PGME), and the cross-linking agent includes an isocyanate cross-linking agent.

[0017] Furthermore, the fluorine compound modifier includes fluorinated acrylate copolymer and fluorinated polyethylene powder.

[0018] Furthermore, the mass ratio of the fluorinated acrylate copolymer to the fluorinated polyethylene powder is (4-5):3.

[0019] According to a second aspect of the present invention, there is provided a method for preparing the aforementioned high-adhesion and high-water resistance thermal anti-counterfeiting ink for printing, comprising the following steps:

[0020] S1: weighing raw materials according to mass fractions, pre-mixing acrylic emulsion, polyurethane emulsion, first coupling agent, wetting agent and cross-linking agent to obtain a first mixed solution;

[0021] Premixing bisphenol A epoxy resin, fluorine compound modifier, second coupling agent, methyl silane and wax emulsion to obtain a second mixed solution;

[0022] S2: adding the thermochromic dye to the first mixed solution and mixing them uniformly to obtain a third mixed solution;

[0023] S3: The second mixed solution and the third mixed solution are mixed evenly, and ball-milled to a fineness of ≤15 μm, and then the thermosensitive microcapsules are added and dispersed evenly to obtain a fourth mixed solution;

[0024] S4: Evenly mix the fourth mixed solution with the defoaming agent, the leveling agent, and the preservative, and adjust the viscosity with deionized water to obtain a heat-sensitive anti-counterfeiting ink.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] By optimizing the components and processes, each ingredient is immobilized in the network structure, effectively playing its own role, while working synergistically with each other to further enhance the effect, thereby effectively improving adhesion and water resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a process flow chart of the high-adhesion and high-water-resistant heat-sensitive anti-counterfeiting ink for printing of the present invention. DETAILED DESCRIPTION

[0028] In order to better understand the technical content of the present invention, specific embodiments are given and described below with reference to the accompanying drawings.

[0029] Various aspects of the present invention are described in this disclosure with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. The embodiments of the present disclosure are not necessarily intended to be comprehensive. It should be understood that the various concepts and embodiments described above, as well as those described in more detail below, can be implemented in any of a number of ways.

[0030] In an exemplary embodiment of the present invention, a high-adhesion and high-water-resistant heat-sensitive anti-counterfeiting ink for printing is provided, comprising the following components in parts by weight: 30-40 parts of acrylic emulsion, 10-20 parts of polyurethane emulsion, 1-10 parts of bisphenol A epoxy resin, 1-10 parts of thermochromic dye, 1-10 parts of heat-sensitive microcapsules, 1-2 parts of a first coupling agent, 1-2 parts of a second coupling agent, 2-3 parts of a wetting agent, 2-3 parts of a cross-linking agent, 1-5 parts of a fluorine compound modifier, 1-2 parts of methyl silane, 1-2 parts of a wax emulsion, 0.2-1 parts of a defoaming agent, 0.5-1 parts of a leveling agent, and 0.1-0.5 parts of a preservative.

[0031] As a preferred embodiment, the acrylic emulsion is a copolymer of methyl methacrylate and butyl acrylate, which has both high adhesion and flexibility.

[0032] Polyurethane emulsion is a polyurethane emulsion containing long-chain alkyl or aromatic groups to improve adhesion and water resistance to non-polar substrates.

[0033] As a preferred embodiment, the polyurethane emulsion is a polyurethane emulsion containing a long-chain alkyl group, and the preparation process is as follows:

[0034] Mix MDI, polyether polyol containing long-chain alkyl, polyhexanediol adipate polyol and cosolvent in a reaction kettle, and stir at 80-90° C. for 2-4 hours to obtain a prepolymer;

[0035] gradually adding the prepolymer into the emulsifier solution to form an emulsion under ultrasonic emulsification conditions;

[0036] Add ethylenediamine to the emulsion and continue stirring at 50-60°C until the reaction is complete;

[0037] The pH of the product after the reaction is adjusted to neutral, and the solvent is removed by distillation under reduced pressure after filtration to obtain a polyurethane emulsion containing a long-chain alkyl group.

[0038] As a preferred embodiment, the mass ratio of MDI, the long-chain alkyl-containing polyether polyol and the poly(hexamethylene adipate) polyol is 3:(2.5-3):2, and the mass ratio of ethylenediamine to MDI is 1:6.

[0039] As a preferred embodiment, the emulsifier includes a fatty acid salt emulsifier and a silicone emulsifier, wherein the fatty acid salt emulsifier accounts for 5-15% of the prepolymer weight, and the silicone emulsifier accounts for 1-5% of the prepolymer weight.

[0040] As a preferred embodiment, the first coupling agent includes γ-aminopropyltriethoxysilane (APTES), which can form a chemical bond between the ink and the substrate to improve adhesion.

[0041] The second coupling agent includes γ-glycidoxypropyltrimethoxysilane (GPTMS), which enhances the chemical bond with the substrate, providing adhesion and water resistance.

[0042] As a preferred embodiment, the wetting agent includes a glycol ether wetting agent (PGME), which helps to improve the surface wettability of the ink, promotes uniform coating, and improves adhesion.

[0043] Cross-linking agents include isocyanate cross-linking agents, such as hexamethylene diisocyanate (HDI), which reacts with the ink during the film-forming process to form a network structure, thereby increasing the cross-linking density of the ink after film formation, and enhancing adhesion and water resistance.

[0044] In another preferred embodiment, the cross-linking agent further includes triethylenetetramine (TETA) as a curing agent for the epoxy resin to further increase the cross-linking density.

[0045] It is understandable that when TETA is used as a cross-linking agent, an isocyanate cross-linking agent must also be present, and TETA accounts for 10-15% of the total cross-linking agent mass.

[0046] As a preferred embodiment, the fluorine compound modifier includes fluorinated acrylate copolymer and fluorinated polyethylene powder, which enhances the hydrophobicity of the ink and improves its water resistance.

[0047] As a further preferred embodiment, the mass ratio of the fluorinated acrylate copolymer to the fluorinated polyethylene powder is (4-5):3.

[0048] As a preferred embodiment, the wax emulsion includes polyethylene wax emulsion, which forms a hydrophobic layer on the film-forming surface to improve water resistance; and methylsilane can increase hydrophobicity and improve water resistance.

[0049] It is understandable that the defoaming agent, leveling agent and preservative in the components can be selected from common types in the art and are not further limited here.

[0050] Combine Figure 1 As shown, in another exemplary embodiment of the present invention, a method for preparing the aforementioned high-adhesion and high-water-resistance thermal anti-counterfeiting ink for printing is also provided, comprising the following steps:

[0051] S1: weighing raw materials according to mass fractions, pre-mixing acrylic emulsion, polyurethane emulsion, first coupling agent, wetting agent and cross-linking agent to obtain a first mixed solution;

[0052] Premixing bisphenol A epoxy resin, fluorine compound modifier, second coupling agent, methyl silane and wax emulsion to obtain a second mixed solution;

[0053] S2: adding the thermochromic dye to the first mixed solution and mixing them uniformly to obtain a third mixed solution;

[0054] S3: The second mixed solution and the third mixed solution are mixed evenly, and ball-milled to a fineness of ≤15 μm, and then the thermosensitive microcapsules are added and dispersed evenly to obtain a fourth mixed solution;

[0055] S4: Evenly mix the fourth mixed solution with the defoaming agent, the leveling agent, and the preservative, and adjust the viscosity with deionized water to obtain a heat-sensitive anti-counterfeiting ink.

[0056] For better understanding, the present invention is further described below with reference to several specific examples, but the preparation process is not limited thereto, and the content of the present invention is not limited thereto.

[0057] Unless otherwise specified, the materials in the examples were prepared according to existing methods or purchased directly from the market.

[0058] In the following examples and comparative examples, the first coupling agent used was APTES, the second coupling agent was GPTMS, the wetting agent was PGME, the crosslinking agent was HDI, the fluorinated compound modifier was a fluorinated acrylate copolymer and a fluorinated polyethylene micropowder (mass ratio 4:3), the wax emulsion was a polyethylene wax emulsion, the defoamer was BYK-024, the leveling agent was BYK-333, and the preservative was Dowicil 75.

[0059] Polyurethane emulsion is a polyurethane emulsion containing long-chain alkyl groups, and the preparation process is as follows:

[0060] MDI, a polyether polyol containing a long-chain alkyl group, polyhexanediol adipate polyol and a cosolvent are mixed in a reaction kettle and stirred at 80-90° C. for 2-4 hours to obtain a prepolymer; the mass ratio of MDI, the polyether polyol containing a long-chain alkyl group and the polyhexanediol adipate polyol is 3:2.5:2.

[0061] The prepolymer is gradually added to the emulsifier solution to form an emulsion under ultrasonic emulsification conditions; the fatty acid salt emulsifier accounts for 10% of the prepolymer mass, and the silicone emulsifier accounts for 3% of the prepolymer mass.

[0062] Add ethylenediamine to the emulsion at a mass ratio of ethylenediamine to MDI of 1:6, and continue stirring at 50-60°C until the reaction is complete.

[0063] The pH of the product after the reaction is adjusted to neutral, and the solvent is removed by distillation under reduced pressure after filtration to obtain a polyurethane emulsion containing a long-chain alkyl group. Example 1

[0064] 30 parts of acrylic emulsion, 20 parts of polyurethane emulsion, 5 parts of bisphenol A epoxy resin, 5 parts of thermochromic dye, 5 parts of thermosensitive microcapsules, 1 part of first coupling agent, 1 part of second coupling agent, 2 parts of wetting agent, 2 parts of crosslinking agent, 3 parts of fluorine compound modifier, 1 part of methyl silane, 1 part of wax emulsion, 0.6 parts of defoaming agent, 0.6 parts of leveling agent, and 0.5 parts of preservative.

[0065] S1: Weigh the raw materials according to their weight parts, and pre-mix the acrylic emulsion, the polyurethane emulsion, the first coupling agent, the wetting agent and the cross-linking agent at a rotation speed of 300 rpm to obtain a first mixed solution.

[0066] The bisphenol A epoxy resin, the fluorine compound modifier, the second coupling agent, the methyl silane and the wax emulsion were pre-mixed at a rotation speed of 300 rpm to obtain a second mixed solution.

[0067] S2: adding the thermochromic dye to the first mixed solution, and mixing them uniformly at a rotation speed of 300 rpm to obtain a third mixed solution.

[0068] S3: The second mixed solution and the third mixed solution were mixed uniformly at a rotation speed of 600 rpm, and ball-milled to a fineness of ≤15 μm, and then the thermosensitive microcapsules were added and dispersed uniformly at a rotation speed of 300 rpm to obtain a fourth mixed solution.

[0069] S4: The fourth mixed solution is mixed evenly with the defoaming agent, the leveling agent, and the preservative at a rotation speed of 300 rpm, and the viscosity is adjusted with deionized water to obtain a thermosensitive anti-counterfeiting ink. Example 2

[0070] 40 parts of acrylic emulsion, 10 parts of polyurethane emulsion, 8 parts of bisphenol A epoxy resin, 8 parts of thermochromic dye, 8 parts of thermosensitive microcapsules, 2 parts of first coupling agent, 2 parts of second coupling agent, 3 parts of wetting agent, 3 parts of crosslinking agent, 5 parts of fluorine compound modifier, 2 parts of methyl silane, 2 parts of wax emulsion, 0.6 parts of defoaming agent, 0.6 parts of leveling agent, and 0.5 parts of preservative.

[0071] S1: Weigh the raw materials according to their weight parts, and pre-mix the acrylic emulsion, the polyurethane emulsion, the first coupling agent, the wetting agent and the cross-linking agent at a rotation speed of 300 rpm to obtain a first mixed solution.

[0072] The bisphenol A epoxy resin, the fluorine compound modifier, the second coupling agent, the methyl silane and the wax emulsion were pre-mixed at a rotation speed of 300 rpm to obtain a second mixed solution.

[0073] S2: adding the thermochromic dye to the first mixed solution, and mixing them uniformly at a rotation speed of 300 rpm to obtain a third mixed solution.

[0074] S3: The second mixed solution and the third mixed solution were mixed uniformly at a rotation speed of 600 rpm, and ball-milled to a fineness of ≤15 μm, and then the thermosensitive microcapsules were added and dispersed uniformly at a rotation speed of 300 rpm to obtain a fourth mixed solution.

[0075] S4: The fourth mixed solution is mixed evenly with the defoaming agent, the leveling agent, and the preservative at a rotation speed of 300 rpm, and the viscosity is adjusted with deionized water to obtain a thermosensitive anti-counterfeiting ink. Example 3

[0076] 40 parts of acrylic emulsion, 20 parts of polyurethane emulsion, 10 parts of bisphenol A epoxy resin, 10 parts of thermochromic dye, 5 parts of thermosensitive microcapsules, 2 parts of first coupling agent, 2 parts of second coupling agent, 3 parts of wetting agent, 3 parts of crosslinking agent, 5 parts of fluorine compound modifier, 2 parts of methyl silane, 2 parts of wax emulsion, 0.6 parts of defoaming agent, 0.6 parts of leveling agent, and 0.5 parts of preservative.

[0077] S1: Weigh the raw materials according to their weight parts, and pre-mix the acrylic emulsion, the polyurethane emulsion, the first coupling agent, the wetting agent and the cross-linking agent at a rotation speed of 300 rpm to obtain a first mixed solution.

[0078] The bisphenol A epoxy resin, the fluorine compound modifier, the second coupling agent, the methyl silane and the wax emulsion were pre-mixed at a rotation speed of 300 rpm to obtain a second mixed solution.

[0079] S2: adding the thermochromic dye to the first mixed solution, and mixing them uniformly at a rotation speed of 300 rpm to obtain a third mixed solution.

[0080] S3: The second mixed solution and the third mixed solution were mixed uniformly at a rotation speed of 600 rpm, and ball-milled to a fineness of ≤15 μm, and then the thermosensitive microcapsules were added and dispersed uniformly at a rotation speed of 300 rpm to obtain a fourth mixed solution.

[0081] S4: The fourth mixed solution is mixed evenly with the defoaming agent, the leveling agent, and the preservative at a rotation speed of 300 rpm, and the viscosity is adjusted with deionized water to obtain a thermosensitive anti-counterfeiting ink. Comparative Example 1

[0082] 40 parts of acrylic emulsion, 20 parts of polyurethane emulsion, 10 parts of bisphenol A epoxy resin, 10 parts of thermochromic dye, 5 parts of thermosensitive microcapsules, 2 parts of first coupling agent, 2 parts of second coupling agent, 3 parts of wetting agent, 3 parts of crosslinking agent, 5 parts of fluorine compound modifier, 2 parts of methyl silane, 2 parts of wax emulsion, 0.6 parts of defoaming agent, 0.6 parts of leveling agent, and 0.5 parts of preservative.

[0083] S1: Weigh the raw materials according to their weight parts, and pre-mix the acrylic emulsion, the polyurethane emulsion, the first coupling agent, the wetting agent and the cross-linking agent at a rotation speed of 300 rpm to obtain a first mixed solution.

[0084] S2: adding bisphenol A epoxy resin, fluorine compound modifier, second coupling agent, methyl silane, wax emulsion and thermochromic dye to the first mixed solution, and mixing at a rotation speed of 300 rpm to obtain a second mixed solution.

[0085] S3: The second mixed solution was ball-milled to a fineness of ≤15 μm, and then the thermosensitive microcapsules were added and dispersed uniformly at a rotation speed of 300 rpm to obtain a third mixed solution.

[0086] S4: The third mixed solution is mixed evenly with the defoaming agent, the leveling agent, and the preservative at a rotation speed of 300 rpm, and the viscosity is adjusted with deionized water to obtain a thermosensitive anti-counterfeiting ink. Comparative Example 2

[0087] 40 parts of acrylic emulsion, 20 parts of polyurethane emulsion, 10 parts of bisphenol A epoxy resin, 10 parts of thermochromic dye, 5 parts of thermosensitive microcapsules, 2 parts of first coupling agent, 2 parts of second coupling agent, 3 parts of wetting agent, 3 parts of crosslinking agent, 5 parts of fluorine compound modifier, 2 parts of methyl silane, 2 parts of wax emulsion, 0.6 parts of defoaming agent, 0.6 parts of leveling agent, and 0.5 parts of preservative.

[0088] S1: Weigh the raw materials according to their weight parts, and pre-mix the bisphenol A epoxy resin, the fluorine compound modifier, the second coupling agent, the methyl silane and the wax emulsion at a rotation speed of 300 rpm to obtain a first mixed solution.

[0089] S2: adding acrylic emulsion, polyurethane emulsion, first coupling agent, wetting agent, crosslinking agent and thermochromic dye into the first mixed solution, and mixing at a rotation speed of 300 rpm to obtain a second mixed solution.

[0090] S3: The second mixed solution was ball-milled to a fineness of ≤15 μm, and then the thermosensitive microcapsules were added and dispersed uniformly at a rotation speed of 300 rpm to obtain a fourth mixed solution.

[0091] S4: The fourth mixed solution is mixed evenly with the defoaming agent, the leveling agent, and the preservative at a rotation speed of 300 rpm, and the viscosity is adjusted with deionized water to obtain a thermosensitive anti-counterfeiting ink. Comparative Example 3

[0092] 40 parts of acrylic emulsion, 20 parts of polyurethane emulsion, 10 parts of bisphenol A epoxy resin, 10 parts of thermochromic dye, 5 parts of thermosensitive microcapsules, 2 parts of first coupling agent, 2 parts of second coupling agent, 3 parts of wetting agent, 3 parts of crosslinking agent, 5 parts of fluorine compound modifier, 2 parts of methyl silane, 2 parts of wax emulsion, 0.6 parts of defoaming agent, 0.6 parts of leveling agent, and 0.5 parts of preservative.

[0093] S1: Weigh the raw materials according to their weight, and stir the acrylic emulsion, polyurethane emulsion, and bisphenol A epoxy resin at a rotation speed of 300 rpm to obtain a first mixed solution.

[0094] S2: adding the first coupling agent and the second coupling agent to the first mixed solution, stirring at a rotation speed of 300 rpm to obtain a second mixed solution.

[0095] S3: adding a wetting agent to the second mixed solution, stirring at a rotation speed of 300 rpm until uniform, then adding a cross-linking agent, and continuing to stir until uniform, to obtain a third mixed solution.

[0096] S4: adding the thermochromic dye to the first mixed solution, mixing uniformly at a rotation speed of 300 rpm, and ball-milling to a fineness of ≤15 μm, then adding the thermosensitive microcapsules, and dispersing uniformly at a rotation speed of 300 rpm to obtain a fourth mixed solution.

[0097] S5: Add the fluorine compound modifier, methylsilane and wax emulsion to the fourth mixed solution, mix them evenly at a speed of 300 rpm, then continue to add the defoaming agent, leveling agent and preservative, mix them evenly at a speed of 300 rpm, and adjust the viscosity with deionized water to obtain a heat-sensitive anti-counterfeiting ink.

[0098] Performance Testing

[0099] The water-based inks prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests. The viscosity was determined according to the liquid ink viscosity test method (GB / T 13217.4-2008); the adhesion strength was determined according to the liquid ink adhesion strength test method (GB / T 13217.7-2009). An immersion test was conducted by printing the inks prepared in Examples and Comparative Examples on a 5 cm × 5 cm cardboard surface to prepare a sample. The sample was then immersed in water for 48 hours and then observed for surface condition. The scoring criteria are shown in Table 1.

[0100] Table 1

[0101]

[0102] The test results are shown in Table 2:

[0103] Table 2

[0104]

[0105] It can be seen from the above results that the thermosensitive anti-counterfeiting ink prepared by the present invention, through the optimization of components and processes, each component is immobilized in the network structure, effectively playing their respective roles, and at the same time synergistically playing their roles, further enhancing their effectiveness, thereby effectively improving adhesion and water resistance.

[0106] While the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A method for preparing a heat-sensitive anti-counterfeiting ink for high-adhesion and high-water-resistance printing, characterized in that: The thermosensitive anti-counterfeiting ink comprises the following components in parts by weight: 30-40 parts of acrylic emulsion, 10-20 parts of polyurethane emulsion, 1-10 parts of bisphenol A epoxy resin, 1-10 parts of thermochromic dye, 1-10 parts of thermosensitive microcapsules, 1-2 parts of a first coupling agent, 1-2 parts of a second coupling agent, 2-3 parts of a wetting agent, 2-3 parts of a cross-linking agent, 1-5 parts of a fluorine compound modifier, 1-2 parts of methylsilane, 1-2 parts of a wax emulsion, 0.2-1 parts of a defoaming agent, 0.5-1 parts of a leveling agent, and 0.1-0.5 parts of a preservative. Wherein, the acrylic emulsion is a copolymer of methyl methacrylate and butyl acrylate, the polyurethane emulsion is a polyurethane emulsion containing a long-chain alkyl group or an aromatic group, and the fluorine compound modifier includes a fluorinated acrylate copolymer and a fluorinated polyethylene powder; The preparation method of the thermosensitive anti-counterfeiting ink comprises the following steps: S1: weighing raw materials according to their mass fractions, pre-mixing the acrylic emulsion, the polyurethane emulsion, the first coupling agent, the wetting agent, and the cross-linking agent to obtain a first mixed solution; Premixing bisphenol A epoxy resin, fluorine compound modifier, second coupling agent, methyl silane and wax emulsion to obtain a second mixed solution; S2: adding the thermochromic dye to the first mixed solution and mixing them uniformly to obtain a third mixed solution; S3: The second mixed solution and the third mixed solution are mixed evenly, and ball-milled to a fineness of ≤15 μm, and then the thermosensitive microcapsules are added and dispersed evenly to obtain a fourth mixed solution; S4: Evenly mix the fourth mixed solution with the defoaming agent, the leveling agent, and the preservative, and adjust the viscosity with deionized water to obtain a heat-sensitive anti-counterfeiting ink.

2. The method for preparing a heat-sensitive anti-counterfeiting ink for high-adhesion and high-water-resistance printing according to claim 1, characterized in that: The polyurethane emulsion is a polyurethane emulsion containing long-chain alkyl groups, and the preparation process is as follows: Mix MDI, polyether polyol containing long-chain alkyl, polyhexanediol adipate polyol and cosolvent in a reaction kettle, and stir at 80-90° C. for 2-4 hours to obtain a prepolymer; gradually adding the prepolymer into the emulsifier solution to form an emulsion under ultrasonic emulsification conditions; Add ethylenediamine to the emulsion and continue stirring at 50-60°C until the reaction is complete; The pH of the product after the reaction is adjusted to neutral, and the solvent is removed by distillation under reduced pressure after filtration to obtain a polyurethane emulsion containing a long-chain alkyl group.

3. The method for preparing a heat-sensitive anti-counterfeiting ink for high-adhesion and high-water-resistance printing according to claim 2, characterized in that: The mass ratio of MDI, long-chain alkyl-containing polyether polyol and polyhexamethylene adipate polyol is 3:(2.5-3):2, and the mass ratio of ethylenediamine to MDI is 1:

6.

4. The method for preparing a heat-sensitive anti-counterfeiting ink for high-adhesion and high-water-resistance printing according to claim 2, characterized in that: The emulsifier includes a fatty acid salt emulsifier and a silicone emulsifier. The fatty acid salt emulsifier accounts for 5-15% of the prepolymer weight, and the silicone emulsifier accounts for 1-5% of the prepolymer weight.

5. The method for preparing a heat-sensitive anti-counterfeiting ink for high adhesion and high water resistance printing according to claim 1, characterized in that: The first coupling agent includes γ-aminopropyltriethoxysilane (APTES), and the second coupling agent includes γ-glycidoxypropyltrimethoxysilane (GPTMS).

6. The method for preparing a heat-sensitive anti-counterfeiting ink for high-adhesion and high-water resistance printing according to claim 1, characterized in that: The wetting agent includes a glycol ether wetting agent PGME, and the cross-linking agent includes an isocyanate cross-linking agent.

7. The method for preparing a heat-sensitive anti-counterfeiting ink for high-adhesion and high-water resistance printing according to claim 1, characterized in that: The mass ratio of fluorinated acrylate copolymer to fluorinated polyethylene powder is (4-5):3.

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