A wear-resistant and scratch-resistant printing ink and its preparation method and application

Abstract

The invention relates to the field of printing inks and discloses a wear-resistant and scratch-resistant printing ink, a preparation method thereof, and an application thereof. The printing ink comprises: a modified aqueous polyurethane emulsion, a modified mica sheet, a pigment, an additive, and deionized water; the modified aqueous polyurethane emulsion is prepared by introducing a double-terminal hydroxyl chain extender into a polymer; the double-terminal hydroxyl chain extender is reacted with a Schiff base intermediate obtained by reacting salicylaldehyde and p-aminobenzyl alcohol and isocyanoethyl methacrylate, and the obtained double-bonded Schiff base intermediate is reacted with 1,1,3,3-tetramethyldisiloxane to prepare the ink; the modified mica sheet is reacted with triethylenetetramine, formaldehyde, and acetone, and then formaldehyde is added under alkaline conditions for polycondensation, the obtained cationic polymer and glutaraldehyde are prepared into the cationic mica sheet, and finally polyaniline is grown on the surface of the mica sheet through interfacial polymerization. The ink prepared by the invention has good adhesion, high hardness, and excellent water resistance, wear resistance, heat resistance, antistatic properties, and antibacterial properties.

Description

Technical Field

[0001] The invention belongs to the technical field of printing inks, and in particular relates to a wear-resistant and scratch-resistant printing ink and a preparation method and application thereof. Background Art

[0002] As the printing industry's environmental requirements continue to rise, the use of solvent-based inks has been limited due to concerns about environmental pollution, safety risks, health hazards, high costs, and poor ink transfer efficiency. Compared to traditional inks, water-based inks, which use water as a solvent, can effectively reduce the emission of volatile organic compounds (VOCs), and are increasingly favored by the printing industry for their environmentally friendly properties.

[0003] Water-based inks are mainly composed of binder resins, pigments, additives, etc. Among them, resin, as the core material, has a direct impact on the overall performance of the ink. Water-based polyurethane is widely used in water-based ink resins due to its good film-forming properties, flexibility and chemical stability. However, water-based polyurethane also has certain defects, such as slightly poor wear resistance and scratch resistance. Moreover, since it contains a large number of hydrophilic groups, its water resistance and heat resistance still need to be improved. In addition, due to the insulating effect of the resin, the surface resistivity is very high, which causes electrostatic discharge effects during use, which may cause damage to the substrate and even lead to major accidents and economic losses such as fires. In addition, static electricity will absorb dust, affecting the appearance or function of the coating, which brings certain limitations to the application of water-based polyurethane. Summary of the Invention

[0004] In order to address the deficiencies mentioned in the above-mentioned background technology, the purpose of the present invention is to provide a wear-resistant and scratch-resistant printing ink, a preparation method and application thereof. By adding modified aqueous polyurethane emulsion and modified mica flakes, the prepared ink has good adhesion and high hardness, and at the same time has excellent water resistance, wear resistance, heat resistance, antistatic and antibacterial properties.

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

[0006] A wear-resistant and scratch-resistant printing ink, comprising the following components in parts by weight: 40-60 parts of modified waterborne polyurethane emulsion, 5-15 parts of modified mica flakes, 20-35 parts of pigment, 1-3 parts of defoaming agent, 0.5-1 part of thickener, and 20-30 parts of deionized water;

[0007] The modified waterborne polyurethane emulsion is prepared by using a double-terminal hydroxyl chain extender and 2,2-dimethylol propionic acid as chain extenders, which are introduced into a polymer system during the synthesis of a waterborne polyurethane prepolymer. The double-terminal hydroxyl chain extender is prepared by using salicylaldehyde and p-aminobenzyl alcohol to undergo a Schiff base reaction, and the obtained Schiff base intermediate is subjected to a nucleophilic addition reaction with isocyanoethyl methacrylate to obtain a double-bonded Schiff base intermediate. The double-bonded Schiff base intermediate is then subjected to a hydrosilylation reaction with 1,1,3,3-tetramethyldisiloxane to prepare the modified waterborne polyurethane emulsion.

[0008] The modified mica sheet is prepared by firstly using triethylenetetramine, formaldehyde and acetone to undergo a Mannich reaction, then adding formaldehyde under alkaline conditions to undergo a condensation reaction to obtain a cationic polymer, then using the cationic polymer and glutaraldehyde to prepare a cationic mica sheet, and finally growing polyaniline on the surface of the cationic mica sheet by interfacial polymerization.

[0009] Preferably, the preparation method of the modified aqueous polyurethane emulsion comprises the following steps:

[0010] (1) Salicylaldehyde and p-aminobenzyl alcohol were placed in a reactor, methanol solvent was added, and the reaction was carried out at 55-65°C for 4-5 hours. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation, deionized water was added to the reaction solution, and the solution was continuously shaken until solids precipitated. The solution was left to stand at room temperature for 20-24 hours, and the reaction product was recrystallized from methanol to prepare a Schiff base intermediate.

[0011] (2) A Schiff base intermediate, isocyanoethyl methacrylate, and dibutyltin dilaurate were placed in a reactor, acetone solvent was added, and the mixture was stirred at 40-50°C for 10-12 hours. After the reaction was completed, the solvent was removed by rotary evaporation, and the unreacted product was removed by washing with ether. Finally, the mixture was vacuum dried to obtain a double-bonded Schiff base intermediate.

[0012] (3) Place the double-bonded Schiff base intermediate and the Custer catalyst in a reactor, add toluene solvent, heat to 55-70°C under a nitrogen atmosphere, then add 1,1,3,3-tetramethyldisiloxane, stir and react for 42-48 hours, and after the reaction is completed, remove the unreacted product by rotary evaporation to prepare a double-terminated hydroxyl chain extender;

[0013] (4) Polyester polyol, 2,2-dihydroxymethylpropionic acid and double-terminated hydroxyl chain extender were placed in a reactor, heated to 70-80°C, stirred and reacted for 25-40 minutes under a nitrogen atmosphere, and then isophorone diisocyanate and dibutyltin dilaurate were added to continue the reaction. The system was then cooled to 45-50°C and triethylamine was added for neutralization. Acetone was added during the reaction to reduce the viscosity of the system. After neutralization for 25-40 minutes, the temperature was lowered to room temperature, placed in an ice-water bath, deionized water was added dropwise, and ethylenediamine was added for post-chain extension. The stirring was continued for 1-2 hours, and the acetone was finally removed by rotary evaporation to prepare a modified waterborne polyurethane emulsion.

[0014] Preferably, the molar ratio of salicylaldehyde to p-aminobenzyl alcohol in step (1) is 1:1 to 1.1.

[0015] Preferably, the molar ratio of the Schiff base intermediate to isocyanoethyl methacrylate in step (2) is 1:1 to 1.05.

[0016] Preferably, in step (3), the molar ratio of the double-bonded Schiff base intermediate to 1,1,3,3-tetramethyldisiloxane is 2-2.1:1.

[0017] Preferably, the method for preparing the modified mica sheet comprises the following steps:

[0018] A. Triethylenetetramine was placed in a reactor, and hydrochloric acid solution was added to adjust the pH value of the system to 2-3. Then, formaldehyde and acetone were added, and the mixture was stirred at 18-22°C for 0.5-1h. Then, the pH value of the system was adjusted to 7.5-8 with sodium hydroxide solution. Formaldehyde was continued to be added, and the mixture was subjected to polycondensation reaction at 55-65°C for 30-40min to prepare a cationic polymer.

[0019] B. Dissolving the cationic polymer in deionized water to prepare an aqueous solution with a mass concentration of 8-12%, adjusting the pH value of the solution to 7.5-8 using sodium hydroxide, then adding mica flakes for ultrasonic dispersion, stirring and reacting at 60-75° C. for 0.5-1 h, filtering, washing, and drying after the reaction is completed, and then placing the product in a desiccant containing glutaraldehyde for 10-12 h to promote crosslinking of the cationic polymer on the mica flake surface with glutaraldehyde vapor, and finally taking out the product and drying it to prepare a cationic mica flake;

[0020] C. Add aniline to chloroform to obtain an organic phase solution, ultrasonically disperse cationic mica flakes in deionized water to obtain an aqueous phase dispersion, dissolve ammonium persulfate in a hydrochloric acid solution to obtain an initiator solution, mix the organic phase solution and the aqueous phase dispersion, and after obvious stratification occurs, dropwise add the initiator solution to the upper aqueous phase. Let the reaction system stand for 10 to 12 hours, then filter, wash, and dry to prepare modified mica flakes.

[0021] Preferably, in step C, the mass ratio of aniline to cationic mica flakes is 0.7-1:1.

[0022] Preferably, the defoaming agent is one of organosilicon, polyether-modified silicon and polysiloxane defoaming agents; the thickener is one of sodium carboxymethyl cellulose and sodium carboxymethyl starch.

[0023] A method for preparing a wear-resistant and scratch-resistant printing ink comprises the following steps:

[0024] S1. Weigh each component by weight, add the modified waterborne polyurethane resin emulsion, modified mica flakes, defoamer and deionized water into a stirring tank and mix well to obtain a premix;

[0025] S2. Add pigment and thickener to the premix, continue stirring and mixing evenly, and prepare wear-resistant and scratch-resistant printing ink.

[0026] The invention discloses an application of a wear-resistant and scratch-resistant printing ink, wherein the wear-resistant and scratch-resistant printing ink is applied to paper, fabric, plastic, metal and glass products.

[0027] Beneficial effects of the present invention:

[0028] The invention utilizes the aldehyde group in salicylaldehyde and the amino group in p-aminobenzyl alcohol to undergo a Schiff base reaction to prepare a Schiff base-containing intermediate, then utilizes the phenolic hydroxyl group in the Schiff base-containing intermediate and the isocyanate group in isocyanoethyl methacrylate to undergo a nucleophilic addition reaction to prepare a double-bonded Schiff base-containing intermediate, and then utilizes two silicon-hydrogen bonds in 1,1,3,3-tetramethyldisiloxane to undergo a silicon-hydrogen addition reaction with the double-bonded Schiff base-containing intermediate to prepare a double-terminated hydroxyl chain extender having a Si-O-Si segment, a rigid benzene ring and an antibacterial Schiff base group with water resistance and heat resistance. The double-terminated hydroxyl chain extender and 2,2-dihydroxymethylpropionic acid are used together as chain extenders and are introduced into a polymer system during the synthesis of a water-based polyurethane prepolymer to prepare a modified water-based polyurethane emulsion, which imparts excellent water resistance, heat resistance and antibacterial properties to printing ink.

[0029] The present invention utilizes triethylenetetramine, formaldehyde and acetone to first undergo a Mannich reaction, and then formaldehyde is added under alkaline conditions to undergo a condensation reaction to prepare a cationic polymer. Subsequently, a mica sheet is modified using the cationic polymer and glutaraldehyde. During the modification process, the cationic polymer is adsorbed on the surface of the mica sheet through electrostatic action, and then glutaraldehyde is used to cross-link hydroxyl groups and amine groups to achieve firm adhesion and surface modification of the mica sheet. Subsequently, polyaniline is grown on the surface of the cationic mica sheet through interfacial polymerization to prepare a modified mica sheet. The modified mica sheet avoids the occurrence of agglomeration and lamination phenomena, making it impossible for small molecular components in the ink to linearly penetrate the barrier coating, thereby increasing the path for the small molecular components in the ink to pass through the mica sheet, and further improving the barrier effect of the coating on ink migration. In addition, the modified mica sheet has good compatibility with the waterborne polyurethane molecular chain, and the modified mica sheet is uniformly coated with the resin chain segments, which helps to enhance the antistatic performance of the printing ink. Simultaneously, the addition of the modified mica sheet improves the hardness and wear resistance of the printing ink to a certain extent. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] The water-based coating color paste (8111 bright red) in the examples of the present invention and the comparative examples was produced by Xingtai Hengji New Materials Technology Co., Ltd.

[0032] Example 1 A method for preparing a modified aqueous polyurethane emulsion comprises the following steps:

[0033] (1) 1 mL of salicylaldehyde and 1.2 g of p-aminobenzyl alcohol were placed in a reactor, 50 mL of methanol solvent was added, and the reaction was carried out at 60 ° C for 4 h. After the reaction was completed, the reaction was cooled to room temperature, and the solvent was removed by rotary evaporation. Deionized water was added to the reaction solution and the solution was continuously shaken until solids precipitated. The solution was left to stand at room temperature for 24 h. The reaction product was recrystallized from methanol to prepare a Schiff base intermediate.

[0034] (2) 2.3 g of Schiff base intermediate (Mr = 227.3), 1.6 g of isocyanoethyl methacrylate and 0.001 g of dibutyltin dilaurate were placed in a reactor, 40 mL of acetone solvent was added, and the mixture was stirred at 45 ° C for 12 h. After the reaction was completed, the solvent was removed by rotary evaporation, and the unreacted product was removed by washing with ether. Finally, the double-bonded Schiff base intermediate was prepared by vacuum drying;

[0035] (3) 7.6 g of a double-bonded Schiff base intermediate (Mr = 382.4) and 0.3 g of a Custer catalyst (Pt 2 Wt%, xylene as solvent) were placed in a reactor, 40 mL of toluene solvent was added, and the temperature was raised to 65 °C under a nitrogen atmosphere. Then, 1.3 g of 1,1,3,3-tetramethyldisiloxane was added and stirred for 48 h. After the reaction was completed, the unreacted product was removed by rotary evaporation to prepare a double-terminated hydroxyl chain extender;

[0036] (4) 10 g of polyethylene adipate-1,4-butanediol ester diol, 0.7 g of 2,2-dihydroxymethylpropionic acid and 0.29 g of a double-terminal hydroxyl chain extender were placed in a reactor, heated to 80 °C, and stirred for reaction for 30 min under a nitrogen atmosphere. Then, 4 g of isophorone diisocyanate and 0.001 g of dibutyltin dilaurate were added to continue the reaction. The system was then cooled to 50 °C and neutralized by adding 0.48 g of triethylamine. A small amount of acetone was added during the reaction to reduce the viscosity of the system. After neutralization for 30 min, the system was cooled to room temperature and placed in an ice-water bath. Deionized water was added dropwise and 0.44 g of ethylenediamine was added for post-chain extension. The system was stirred for 1.5 h. Finally, the acetone was removed by rotary evaporation to prepare a modified waterborne polyurethane emulsion with a solid content of 30%.

[0037] Example 2 A method for preparing a modified mica sheet comprises the following steps:

[0038] A. 16 mL of triethylenetetramine was placed in a reactor, and a 1 mol / L hydrochloric acid solution was added to adjust the pH value of the system to 3. Then, 20 mL of formaldehyde and 18 mL of acetone were added, and the mixture was stirred at 20°C for 1 hour. Subsequently, the pH value of the system was adjusted to 8 using a 1 mol / L sodium hydroxide solution, and 18 mL of formaldehyde was added. The mixture was placed at 60°C for 40 minutes for polycondensation to prepare a cationic polymer.

[0039] B. Dissolve the cationic polymer in deionized water to prepare a 10% aqueous solution by mass, adjust the pH value of the solution to 8 using sodium hydroxide, then add 2 g of mica flakes and disperse them evenly by ultrasonication, place them at 70 ° C and stir for 1 h, filter them after completion of the reaction, wash them, and dry them, then place the product in a desiccant containing glutaraldehyde for 12 h, promote the crosslinking of the cationic polymer on the surface of the mica flakes with glutaraldehyde vapor, and finally take out the product and dry it to prepare a cationic mica flake;

[0040] C. Take 0.4 g of aniline and add it to 40 mL of chloroform to obtain an organic phase solution. Take 0.5 g of cationic mica flakes and ultrasonically disperse them in 40 mL of deionized water to obtain an aqueous phase dispersion. Take 0.1 g of ammonium persulfate and dissolve it in 20 mL of 1 mol / L hydrochloric acid solution to obtain an initiator solution. Mix the organic phase solution and the aqueous phase dispersion. After obvious stratification occurs, add the initiator solution dropwise to the upper aqueous phase. After the reaction system is allowed to stand for 12 hours, filter, wash, and dry to prepare modified mica flakes.

[0041] Example 3 A wear-resistant and scratch-resistant printing ink comprises the following components in parts by weight: 44 parts of the modified aqueous polyurethane emulsion prepared in Example 1, 6 parts of the modified mica flakes prepared in Example 2, 24 parts of aqueous coating color paste (8111 bright red), 1 part of defoaming agent J0407, 0.5 parts of thickener sodium carboxymethyl cellulose, and 22 parts of deionized water.

[0042] The preparation method of the above-mentioned wear-resistant and scratch-resistant printing ink comprises the following steps:

[0043] S1. Weigh each component by weight, add the modified waterborne polyurethane resin emulsion, modified mica flakes, defoamer and deionized water into a stirring tank and mix well to obtain a premix;

[0044] S2. Add pigment and thickener to the premix, continue stirring and mixing evenly, and prepare wear-resistant and scratch-resistant printing ink.

[0045] Example 4 A wear-resistant and scratch-resistant printing ink comprises the following components in parts by weight: 51 parts of the modified aqueous polyurethane emulsion prepared in Example 1, 10 parts of the modified mica flakes prepared in Example 2, 30 parts of an aqueous coating color paste (8111 bright red), 2 parts of a defoaming agent J0407, 0.7 parts of a thickener of sodium carboxymethyl cellulose, and 27 parts of deionized water.

[0046] The preparation method of the above-mentioned wear-resistant and scratch-resistant printing ink is the same as that of Example 3.

[0047] Example 5 A wear-resistant and scratch-resistant printing ink comprises the following components in parts by weight: 58 parts of the modified aqueous polyurethane emulsion prepared in Example 1, 13 parts of the modified mica flakes prepared in Example 2, 34 parts of aqueous coating color paste (8111 bright red), 2.5 parts of defoaming agent J0407, 0.8 parts of thickener sodium carboxymethyl cellulose, and 30 parts of deionized water.

[0048] The preparation method of the above-mentioned wear-resistant and scratch-resistant printing ink is the same as that of Example 3.

[0049] Comparative Example 1 A method for preparing an aqueous polyurethane emulsion comprises the following steps:

[0050] 10 g of polyethylene adipate-1,4-butanediol ester diol, 0.7 g of 2,2-dihydroxymethylpropionic acid and 0.03 g of 1,4-butanediol were placed in a reactor, heated to 80 ° C, and stirred for reaction for 30 min under a nitrogen atmosphere. Then, 4 g of isophorone diisocyanate and 0.001 g of dibutyltin dilaurate were added to continue the reaction. The system was then cooled to 50 ° C and 0.48 g of triethylamine was added for neutralization. A small amount of acetone was added during the reaction to reduce the viscosity of the system. After neutralization for 30 min, the temperature was cooled to room temperature, placed in an ice water bath, deionized water was added dropwise, and 0.44 g of ethylenediamine was added for post-chain extension. Stirring was continued for 1.5 h, and finally, the acetone was removed by rotary evaporation to prepare a modified waterborne polyurethane emulsion with a solid content of 30%.

[0051] Comparative Example 2 A wear-resistant and scratch-resistant printing ink comprises the following components in parts by weight: 58 parts of the aqueous polyurethane emulsion prepared in Comparative Example 1, 13 parts of the modified mica flakes prepared in Example 2, 34 parts of an aqueous coating color paste (8111 bright red), 2.5 parts of a defoaming agent J0407, 0.8 parts of a thickener, sodium carboxymethyl cellulose, and 30 parts of deionized water.

[0052] The preparation method of the above-mentioned wear-resistant and scratch-resistant printing ink is the same as that of Example 3.

[0053] Comparative Example 3 A wear-resistant and scratch-resistant printing ink comprises the following components in parts by weight: 58 parts of the modified aqueous polyurethane emulsion prepared in Example 1, 13 parts of the cationic mica flakes prepared in Example 2, 34 parts of an aqueous coating color paste (8111 bright red), 2.5 parts of a defoaming agent J0407, 0.8 parts of a thickener, sodium carboxymethyl cellulose, and 30 parts of deionized water.

[0054] The preparation method of the above-mentioned wear-resistant and scratch-resistant printing ink is the same as that of Example 3.

[0055] Comparative Example 4 A wear-resistant and scratch-resistant printing ink comprises the following components in parts by weight: 58 parts of the modified aqueous polyurethane emulsion prepared in Example 1, 13 parts of mica flakes, 34 parts of aqueous coating color paste (8111 bright red), 2.5 parts of defoaming agent J0407, 0.8 parts of thickener sodium carboxymethyl cellulose, and 30 parts of deionized water.

[0056] The preparation method of the above-mentioned wear-resistant and scratch-resistant printing ink is the same as that of Example 3.

[0057] Performance testing

[0058] The printing inks prepared in Examples 3-5 and Comparative Examples 2-4 were subjected to performance testing:

[0059] (1) Wear resistance test: The wear resistance is evaluated by wear test and change of water contact angle on ink surface. The specific operation is as follows: place a piece of 7000 mesh SiC sandpaper on the ink surface and press a 200g weight on the gauze paper. Drag the sample on the sandpaper horizontally at a constant speed for 10cm, rotate the sample clockwise 90°, and then drag it horizontally at a constant speed for 10cm. This is one cycle. Repeat 30 wear cycles and measure the water contact angle of the ink surface before and after wear. The data results are shown in Table 1.

[0060] (2) Hardness test: According to ASTM D3363-00, the hardness of the ink was tested using a pencil scratch hardness tester. The data results are shown in Table 1.

[0061] (3) Adhesion test: According to ASTM D3359-97, the ink adhesion test was carried out using a grid knife and 3M tape. The data results are shown in Table 1.

[0062] (4) Heat resistance test: Under nitrogen atmosphere, the sample was heated from 35°C to 700°C at a heating rate of 10°C / min. The initial decomposition temperature of the material was recorded and its heat resistance was evaluated. Generally speaking, the higher the initial decomposition temperature, the stronger the heat resistance, and vice versa. The data results are shown in Table 1.

[0063] (5) Antistatic performance test: The surface resistance and volume resistance of the ink were measured using a ZC36 high resistance meter. The antistatic performance was evaluated by comparing the resistance values. The data results are shown in Table 1.

[0064] (6) Antibacterial performance test: The fluorescent Escherichia coli detection method was used to test the antibacterial performance. The ink was screen-printed on a 5cm×5cm fabric. The luminescence range of the colony was 3×10 6 -6×10 6 cfu / mL, the specific operation is: add 800 μL of fluorescent Escherichia coli liquid at different positions on the ink surface, take 200 μL of the ink surface liquid after 60 minutes to test its luminescence value, calculate the inhibition rate according to the change of luminescence value, and obtain the data results as shown in Table 1.

[0065] Table 1 Sample performance test results

[0066] Group Project Example 3 Example 4 Example 5 Comparative Example 2 Comparative Example 3 Comparative Example 4 Water contact angle before wear / ° 97.3 98.5 100.9 83.7 99.3 99.6 Water contact angle after wear / ° 91.7 93.2 94.8 77.2 93.5 85.9 Difference in water contact angle before and after wear / ° 5.6 5.3 6.1 6.5 5.8 13.7 Initial thermal decomposition temperature / ℃ 271.7 283.9 288.6 252.1 285.0 283.3 Adhesion 5B 5B 5B 5B 5B 5B hardness 2H 2H 2H 2H 2H H Surface resistivity / Ω <![CDATA[8.1×10 7 ]]> <![CDATA[7.7×10 7 ]]> <![CDATA[7.4×10 7 ]]> <![CDATA[7.4×10 7 ]]> <![CDATA[9.5×10 7 ]]> <![CDATA[9.9×10 7 ]]> Volume resistivity / Ω·m <![CDATA[9.5×10 7 ]]> <![CDATA[8.8×10 7 ]]> <![CDATA[8.2×10 7 ]]> <![CDATA[8.4×10 7 ]]> <![CDATA[1.5×10 8 ]]> <![CDATA[1.7×10 8 ]]> Antibacterial rate / % 92.3 96.6 97.3 79.9 97.1 96.9

[0067] As can be seen from the data results in Table 1, the inks prepared in Examples 3-5 of the present invention have good adhesion and high hardness, and also have excellent water resistance, wear resistance, heat resistance, antistatic and antibacterial properties. Among them, the aqueous polyurethane emulsion added in Comparative Example 2 did not introduce a double-terminated hydroxyl chain extender, and its measured water contact angle, initial thermal decomposition temperature and antibacterial rate were lower than those of Examples 3-5. The reason is that due to the lack of grafting of Si-O-Si segments and Schiff base groups, the water resistance, heat resistance and antibacterial properties were reduced. In Comparative Example 3, the modified mica sheets were replaced with cationic mica sheets in equal amounts, and the mica sheets were not modified in Comparative Example 4. The surface resistivity and volume resistivity of Comparative Example 3-4 were higher than those of Example 3-5. In addition, the difference in the water contact angle before and after wear of Comparative Example 4 was higher than that of Example 3-5, and the hardness was lower than that of Example 3-5, indicating that the modification of the mica sheets improved the wear resistance, hardness and antistatic properties of the ink to a certain extent.

[0068] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0069] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A wear-resistant and scratch-resistant printing ink, characterized in that: The invention comprises the following components in parts by weight: 40-60 parts of modified waterborne polyurethane emulsion, 5-15 parts of modified mica flakes, 20-35 parts of pigment, 1-3 parts of defoaming agent, 0.5-1 part of thickener, and 20-30 parts of deionized water; The modified waterborne polyurethane emulsion is prepared by using a double-terminal hydroxyl chain extender and 2,2-dimethylol propionic acid as chain extenders, which are introduced into a polymer system during the synthesis of a waterborne polyurethane prepolymer. The double-terminal hydroxyl chain extender is prepared by using salicylaldehyde and p-aminobenzyl alcohol to undergo a Schiff base reaction, and the obtained Schiff base intermediate is subjected to a nucleophilic addition reaction with isocyanoethyl methacrylate to obtain a double-bonded Schiff base intermediate. The double-bonded Schiff base intermediate is then subjected to a hydrosilylation reaction with 1,1,3,3-tetramethyldisiloxane to prepare the modified waterborne polyurethane emulsion. The molar ratio of the double-bonded Schiff base intermediate to 1,1,3,3-tetramethyldisiloxane is 2 to 2.1:1; The modified mica sheet is prepared by firstly using triethylenetetramine, formaldehyde and acetone to undergo a Mannich reaction, then adding formaldehyde under alkaline conditions to undergo a condensation reaction to obtain a cationic polymer, then using the cationic polymer and glutaraldehyde to prepare a cationic mica sheet, and finally growing polyaniline on the surface of the cationic mica sheet by interfacial polymerization.

2. The wear-resistant and scratch-resistant printing ink according to claim 1, characterized in that: The preparation method of the modified aqueous polyurethane emulsion comprises the following steps: (1) Salicylaldehyde and p-aminobenzyl alcohol were placed in a reactor, methanol solvent was added, and the reaction was carried out at 55-65°C for 4-5 hours. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation, deionized water was added to the reaction solution, and the solution was continuously shaken until solids precipitated. The solution was left to stand at room temperature for 20-24 hours, and the reaction product was recrystallized from methanol to prepare a Schiff base intermediate. (2) A Schiff base intermediate, isocyanoethyl methacrylate, and dibutyltin dilaurate were placed in a reactor, acetone solvent was added, and the mixture was stirred at 40-50°C for 10-12 hours. After the reaction was completed, the solvent was removed by rotary evaporation, and the unreacted product was removed by washing with ether. Finally, the mixture was vacuum dried to obtain a double-bonded Schiff base intermediate. (3) Place the double-bonded Schiff base intermediate and the Custer catalyst in a reactor, add toluene solvent, heat to 55-70°C under a nitrogen atmosphere, then add 1,1,3,3-tetramethyldisiloxane, stir and react for 42-48 hours, and after the reaction is completed, remove the unreacted product by rotary evaporation to prepare a double-terminated hydroxyl chain extender; (4) Polyester polyol, 2,2-dihydroxymethylpropionic acid and double-terminated hydroxyl chain extender were placed in a reactor, heated to 70-80°C, stirred and reacted for 25-40 minutes under a nitrogen atmosphere, and then isophorone diisocyanate and dibutyltin dilaurate were added to continue the reaction. The system was then cooled to 45-50°C and triethylamine was added for neutralization. Acetone was added during the reaction to reduce the viscosity of the system. After neutralization for 25-40 minutes, the temperature was lowered to room temperature, placed in an ice-water bath, deionized water was added dropwise, and ethylenediamine was added for post-chain extension. The stirring was continued for 1-2 hours, and the acetone was finally removed by rotary evaporation to prepare a modified waterborne polyurethane emulsion.

3. The wear-resistant and scratch-resistant printing ink according to claim 2, characterized in that: In the step (1), the molar ratio of salicylaldehyde to p-aminobenzyl alcohol is 1:1-1.

1.

4. The wear-resistant and scratch-resistant printing ink according to claim 2, characterized in that: The molar ratio of the Schiff base intermediate to isocyanoethyl methacrylate in step (2) is 1:1 to 1.

05.

5. The wear-resistant and scratch-resistant printing ink according to claim 1, characterized in that: The preparation method of the modified mica sheet comprises the following steps: A. Triethylenetetramine was placed in a reactor, and hydrochloric acid solution was added to adjust the pH value of the system to 2-3. Then, formaldehyde and acetone were added, and the mixture was stirred at 18-22°C for 0.5-1h. Then, the pH value of the system was adjusted to 7.5-8 with sodium hydroxide solution. Formaldehyde was continued to be added, and the mixture was subjected to polycondensation reaction at 55-65°C for 30-40min to prepare a cationic polymer. B. Dissolving the cationic polymer in deionized water to prepare an aqueous solution with a mass concentration of 8-12%, adjusting the pH value of the solution to 7.5-8 using sodium hydroxide, then adding mica flakes for ultrasonic dispersion, stirring and reacting at 60-75° C. for 0.5-1 h, filtering, washing, and drying after the reaction is completed, and then placing the product in a desiccant containing glutaraldehyde for 10-12 h to promote crosslinking of the cationic polymer on the mica flake surface with glutaraldehyde vapor, and finally taking out the product and drying it to prepare a cationic mica flake; C. Add aniline to chloroform to obtain an organic phase solution, ultrasonically disperse cationic mica flakes in deionized water to obtain an aqueous phase dispersion, dissolve ammonium persulfate in a hydrochloric acid solution to obtain an initiator solution, mix the organic phase solution and the aqueous phase dispersion, and after obvious stratification occurs, dropwise add the initiator solution to the upper aqueous phase. Let the reaction system stand for 10 to 12 hours, then filter, wash, and dry to prepare modified mica flakes.

6. The wear-resistant and scratch-resistant printing ink according to claim 5, characterized in that: In step C, the mass ratio of aniline to cationic mica flakes is 0.7-1:

1.

7. The wear-resistant and scratch-resistant printing ink according to claim 1, characterized in that: The defoaming agent is one of organic silicon, polyether modified silicon and polysiloxane defoaming agents; the thickener is one of sodium carboxymethyl cellulose and sodium carboxymethyl starch.

8. A method for preparing the wear-resistant and scratch-resistant printing ink according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Weigh each component by weight, add the modified waterborne polyurethane resin emulsion, modified mica flakes, defoamer and deionized water into a stirring tank and mix well to obtain a premix; S2. Add pigment and thickener to the premix, continue stirring and mixing evenly, and prepare wear-resistant and scratch-resistant printing ink.

9. A use of the wear-resistant and scratch-resistant printing ink according to claim 1, characterized in that: The wear-resistant and scratch-resistant printing ink is applicable to paper, fabric, plastic, metal and glass products.