A high-performance direct-liquid environmentally friendly ink and its preparation method

Abstract

This invention belongs to the field of ink technology, specifically relating to a high-performance direct-liquid environmentally friendly ink and its preparation method. This high-performance direct-liquid environmentally friendly ink, by weight, comprises 5-10 parts edible pigment, 18-25 parts propylene glycol, 4-6 parts binder, 0.5-2 parts surfactant, 0.1-0.4 parts antibacterial agent, 0.2-0.5 parts rust inhibitor, 0.5-1.5 parts pH neutralizer, and 60-65 parts deionized water; the binder is a mixture of polyurethane emulsion and epoxy resin emulsion in a weight ratio of 1.5-2.5:3. This invention, through optimized formulation and using safe and environmentally friendly materials as raw materials, yields an ink that is safe and environmentally friendly to use, harmless to the human body, has a long shelf life, and exhibits good stability, dryness resistance, film-forming properties, and leak-proof performance, making it suitable for use in direct-liquid water-based pens.

Description

Technical Field

[0001] This invention belongs to the field of ink technology, specifically relating to a high-performance direct-liquid environmentally friendly ink and its preparation method. Background Technology

[0002] Direct-liquid water-based pens are increasingly favored among stationery pens due to their smooth writing, comfortable feel, and resistance to broken lines. However, the inks they use mostly use ethylene glycol as the main solvent, which is toxic to animals and harmful to health with long-term use. Furthermore, direct-liquid water-based inks are divided into water-based dye-based inks and water-based pigment-based inks. While water-based pigment-based inks offer better water and sunlight resistance and longer shelf life, their pigments are primarily organic compounds, and the use of organic solvents results in high volatility. Long-term use by children and exposure to volatile organic gases is detrimental to their health. Water-based dye-based inks can improve safety by selecting environmentally friendly dyes, but their durability, dryness resistance, and leak resistance are relatively poor. Therefore, it is essential to develop a direct-liquid ink that ensures the safety of water-based inks while also improving their performance. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a high-performance direct-liquid environmentally friendly ink and its preparation method. This high-performance direct-liquid environmentally friendly ink uses environmentally friendly materials such as edible color paste to replace organic pigments, non-toxic propylene glycol as a solvent, and natural antibacterial agents as raw materials, making it safe and environmentally friendly to use. The added novel binder can form a film at the pen tip, ensuring that the ink does not leak for a long time and has good smoothness when writing again. When used in direct-liquid water-based pens, it has good preservation, strong dryness resistance, and excellent leakage resistance, with excellent and stable overall performance.

[0004] To achieve the above objectives, the present invention provides a high-performance direct-liquid environmentally friendly ink, comprising the following raw material components by weight: 5-10 parts edible pigment, 18-25 parts propylene glycol, 4-6 parts binder, 0.5-2 parts surfactant, 0.1-0.4 parts antibacterial agent, 0.2-0.5 parts rust inhibitor, 0.5-1.5 parts pH neutralizer, and 60-65 parts deionized water;

[0005] The binder is a mixture of polyurethane emulsion and epoxy resin emulsion in a weight ratio of 1.5-2.5:3.

[0006] This invention uses edible pigments as the main raw materials, propylene glycol as the solvent, and natural antibacterial agents, resulting in an ink that is safe and environmentally friendly. The binder is a mixture of polyurethane emulsion and epoxy resin emulsion. The polyurethane emulsion has excellent film mechanical properties, water resistance, aging resistance, and dispersibility, and is pollution-free and safe. The epoxy resin emulsion is an aqueous emulsion of liquid epoxy resin, characterized by small particle size, water resistance, storage stability, and zero VOCs. By mixing the two as a novel binder, the advantages of both can be effectively combined, further improving the ink's safety, stability, water resistance, film-forming properties, and leak resistance. After using this novel binder and drying for a period of time, a soft film will form at the pen tip, ensuring that the ink will not leak during long-term storage. Moreover, the film formed is easy to break when writing again, without affecting the ink's flowability and resulting in good pen performance.

[0007] Furthermore, in the above technical solution, the polyurethane emulsion is composed of modified polyurethane emulsion and waterborne polyurethane emulsion mixed in a weight ratio of 2-3:1.

[0008] Furthermore, in the above technical solution, the modified polyurethane emulsion is a butyl acrylate modified polyurethane emulsion. The modification method is as follows: the polyurethane emulsion is first added to a dispersion vessel, heated to 35-45℃, an initiator and butyl acrylate are added, stirred and mixed, and the temperature is further increased to 75-95℃. The mixture is stirred and reacted for 2-3 hours to obtain the modified polyurethane emulsion. The mass ratio of polyurethane emulsion, initiator, and butyl acrylate is 1:0.01-0.1:0.3-0.8. This invention introduces ether bonds into the polyurethane emulsion structure. After a high-temperature reaction, a three-dimensional network structure can be formed on the polyurethane surface, improving the surface energy and tension of the polyurethane emulsion film. This allows for the formation of a soft film on the pen tip, preventing ink leakage. Simultaneously, this film can rupture upon re-engraving, exhibiting excellent performance. Specifically, any commonly used initiator can be used.

[0009] Furthermore, in the above technical solution, the edible color paste is one or more of edible lemon yellow, edible orange yellow, edible carmine, edible amaranth, edible indigo, and edible brilliant blue. This invention uses edible color paste as dye, which is pollution-free and requires no special organic solvents for dissolution, making it safe and environmentally friendly.

[0010] Furthermore, in the above technical solution, the surfactant is a polyoxyethylene ether phosphate. This invention selects polyoxyethylene ether phosphates as surfactants, which have excellent water solubility, dispersibility, and rust-preventive properties, are safe and non-irritating, and have good pH stability; they can be lauryl alcohol polyoxyethylene ether phosphate, fatty alcohol ether phosphate, etc.

[0011] Furthermore, in the above technical solution, the antibacterial agent is any one of β-1,4-polyglucosamine, O-hydroxymethyl chitosan, and trehalose. This invention selects a natural antibacterial agent, which has good biocompatibility, produces no pollutants, and is safe and environmentally friendly.

[0012] Furthermore, in the above technical solution, the rust inhibitor is a modified borate ester or triethanolamine borate ester; the pH neutralizer is one or more of triethanolamine, ammonia, sodium hydroxide, and potassium hydroxide. Modified borate ester is a product containing nitrogen borate ester derivatives, possessing the excellent rust prevention and extreme pressure anti-wear properties of traditional borate esters, as well as good corrosion resistance, while also exhibiting good pH stability and antibacterial properties. Triethanolamine borate ester is also a product containing nitrogen borate ester derivatives, possessing good extreme pressure and rust prevention properties. The pH of the ink is adjusted to 7-9 using a pH neutralizer.

[0013] This invention also provides a method for preparing a high-performance direct-liquid environmentally friendly ink, comprising the following steps:

[0014] S1. According to the formula, add the edible color paste, binder, propylene glycol, pH neutralizer and half of the deionized water into the dispersion tank in sequence, then add the surfactant and stir for 1-2 hours to obtain the mixture;

[0015] S2. Add the mixture obtained in S1 into a high-speed grinding mill and disperse for 2-3 hours to obtain the grinding material;

[0016] S3. Add the abrasive obtained in S2 into the dispersion vessel, then add the antibacterial agent, rust inhibitor and remaining deionized water in sequence. After stirring evenly, perform negative pressure treatment on the dispersion vessel to remove air bubbles and then filter to obtain high-performance direct liquid environmentally friendly ink.

[0017] Furthermore, in the above technical solution, in S2, the high-speed grinding speed is 2500-3000 r / min.

[0018] Furthermore, in the above technical solution, in S3, the pressure of the negative pressure treatment is negative 0.1-0.5MPa.

[0019] The beneficial effects of this invention are:

[0020] 1. This invention optimizes the formula, using safe and environmentally friendly raw materials as the main components, resulting in ink that is safe and environmentally friendly to use and harmless to the human body. Using butyl acrylate modified polyurethane emulsion and epoxy resin emulsion as binders can effectively improve the ink's stability, water resistance, film-forming properties, and leak resistance, while ensuring its writing performance. The addition of antibacterial and rust inhibitors ensures the ink's storability and improves its stability after writing, allowing it to be stored for a long time without discoloration.

[0021] 2. The preparation method of the present invention involves mixing and reacting first, then high-speed grinding and dispersing, and finally adding antibacterial and rust inhibitors and degassing treatment, which can improve the uniformity, stability and antibacterial properties of ink. The method is simple and easy to operate.

[0022] 3. The ink obtained by this invention has a long shelf life, strong resistance to ink leakage and drying, and is stable, making it suitable for use in direct-liquid water-based pens. Furthermore, due to its good leakage resistance, the writing length can be increased by extending the pen barrel, reducing the consumption of pen barrel and nib materials, thus achieving energy conservation and environmental protection. Detailed Implementation

[0023] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the raw materials used in the following examples are all commercially available products and can be purchased from the market.

[0024] The present invention will be further described in detail below with reference to embodiments:

[0025] Example 1

[0026] A high-performance direct-liquid environmentally friendly ink, comprising the following raw material components by weight:

[0027] 5 parts of edible color paste (edible brilliant blue);

[0028] 20 parts propylene glycol;

[0029] 5 parts of connector material;

[0030] 2 parts surfactant (polyoxyethylene ether phosphate);

[0031] 0.2 parts of antibacterial agent (β-1,4-polyglucosamine);

[0032] Rust inhibitor (modified borate ester) 0.2 parts;

[0033] 1 part pH neutralizer (triethanolamine);

[0034] 63 parts of deionized water;

[0035] The binder is a mixture of polyurethane emulsion and epoxy resin emulsion in a weight ratio of 2:3.

[0036] The polyurethane emulsion is a mixture of modified polyurethane emulsion and waterborne polyurethane emulsion in a weight ratio of 2:1.

[0037] The modified polyurethane emulsion is a butyl acrylate modified polyurethane emulsion. The modification method is as follows: the polyurethane emulsion is first added to a dispersion vessel, heated to 40°C, then azobisisovalerate and butyl acrylate are added, stirred and mixed, and the temperature is further increased to 80°C. The mixture is stirred and reacted for 2.5 hours to obtain the modified polyurethane emulsion.

[0038] A method for preparing high-performance direct-liquid environmentally friendly ink includes the following steps:

[0039] S1. According to the formula, add the edible color paste, binder, propylene glycol, pH neutralizer and half of the deionized water into the dispersion tank in sequence, then add the surfactant and stir for 1 hour to obtain the mixture;

[0040] S2. Add the mixture obtained in S1 into a high-speed grinder and grind and disperse it at a speed of 2500 r / min for 3 hours to obtain the grinding material;

[0041] S3. Add the abrasive obtained in S2 into the dispersion vessel, then add the antibacterial agent, rust inhibitor and remaining deionized water in sequence. After stirring evenly, apply negative pressure to the dispersion vessel at a pressure of -0.2MPa to remove air bubbles and then filter to obtain high-performance direct-liquid environmentally friendly ink.

[0042] Example 2

[0043] A high-performance direct-liquid environmentally friendly ink, comprising the following raw material components by weight:

[0044] 8 parts of edible coloring (edible carmine);

[0045] 22 parts of propylene glycol;

[0046] 4 parts of connector material;

[0047] 2 parts surfactant (polyoxyethylene ether phosphate);

[0048] 0.1 parts of antibacterial agent (O-hydroxymethyl chitosan);

[0049] Rust inhibitor (triethanolamine borate) 0.5 parts;

[0050] pH neutralizing agent (ammonia water) 0.8 parts;

[0051] 60 parts deionized water;

[0052] The binder is a mixture of polyurethane emulsion and epoxy resin emulsion in a weight ratio of 1.5:3.

[0053] The polyurethane emulsion is a mixture of modified polyurethane emulsion and waterborne polyurethane emulsion in a weight ratio of 3:1.

[0054] The modified polyurethane emulsion is a butyl acrylate modified polyurethane emulsion. The modification method is as follows: the polyurethane emulsion is first added to a dispersion vessel, heated to 35°C, then azobisisovalerate and butyl acrylate are added, stirred and mixed, and the temperature is further increased to 75°C. The mixture is stirred and reacted for 3 hours to obtain the modified polyurethane emulsion.

[0055] A method for preparing high-performance direct-liquid environmentally friendly ink includes the following steps:

[0056] S1. According to the formula, add the edible color paste, binder, propylene glycol, pH neutralizer and half of the deionized water into the dispersion tank in sequence, then add the surfactant and stir for 1-2 hours to obtain the mixture;

[0057] S2. Add the mixture obtained in S1 into a high-speed mill and grind and disperse it at a speed of 2800 r / min for 2.5 h to obtain the grinding material;

[0058] S3. Add the abrasive obtained in S2 into the dispersion vessel, then add the antibacterial agent, rust inhibitor and remaining deionized water in sequence. After stirring evenly, apply negative pressure to the dispersion vessel at a pressure of -0.1 MPa to remove air bubbles and then filter to obtain high-performance direct-liquid environmentally friendly ink.

[0059] Example 3

[0060] A high-performance direct-liquid environmentally friendly ink, comprising the following raw material components by weight:

[0061] 10 parts of edible coloring (edible lemon yellow);

[0062] 25 parts of propylene glycol;

[0063] 6 parts of binder material;

[0064] 1 part surfactant (polyoxyethylene ether phosphate);

[0065] Trehalose 0.4 parts;

[0066] 0.3 parts of modified borate ester;

[0067] Sodium hydroxide 0.2 parts;

[0068] 66 parts of deionized water;

[0069] The binder is a mixture of polyurethane emulsion and epoxy resin emulsion in a weight ratio of 2.5:3.

[0070] The polyurethane emulsion is a mixture of modified polyurethane emulsion and waterborne polyurethane emulsion in a weight ratio of 2:1.

[0071] The modified polyurethane emulsion is a butyl acrylate modified polyurethane emulsion. The modification method is as follows: the polyurethane emulsion is first added to a dispersion vessel, heated to 45°C, then azobisisovalerate and butyl acrylate are added, stirred and mixed, and the temperature is further increased to 95°C. The mixture is stirred and reacted for 2 hours to obtain the modified polyurethane emulsion.

[0072] A method for preparing high-performance direct-liquid environmentally friendly ink includes the following steps:

[0073] S1. According to the formula, add the edible color paste, binder, propylene glycol, pH neutralizer and half of the deionized water into the dispersion tank in sequence, then add the surfactant and stir for 2 hours to obtain the mixture;

[0074] S2. Add the mixture obtained in S1 into a high-speed grinder and grind and disperse it at a speed of 3000 r / min for 2 hours to obtain the grinding material;

[0075] S3. Add the abrasive obtained in S2 into the dispersion vessel, then add the antibacterial agent, rust inhibitor and remaining deionized water in sequence. After stirring evenly, apply negative pressure to the dispersion vessel at a pressure of -0.5MPa to remove air bubbles and then filter to obtain high-performance direct-liquid environmentally friendly ink.

[0076] Comparative Example 1

[0077] A direct-liquid environmentally friendly ink, comprising the following raw material components by weight:

[0078] 5 parts of edible color paste (edible brilliant blue);

[0079] 20 parts propylene glycol;

[0080] 5 parts of connector material;

[0081] 2 parts surfactant (polyoxyethylene ether phosphate);

[0082] 0.2 parts of antibacterial agent (β-1,4-polyglucosamine);

[0083] Rust inhibitor (modified borate ester) 0.2 parts;

[0084] 1 part pH neutralizer (triethanolamine);

[0085] 63 parts of deionized water;

[0086] The binder is an epoxy resin emulsion;

[0087] The preparation method of the direct-liquid environmentally friendly ink is the same as that in Example 1.

[0088] Comparative Example 2

[0089] A direct-liquid environmentally friendly ink, comprising the following raw material components by weight:

[0090] 5 parts of edible color paste (edible brilliant blue);

[0091] 20 parts propylene glycol;

[0092] 5 parts of connector material;

[0093] 2 parts surfactant (polyoxyethylene ether phosphate);

[0094] 0.2 parts of antibacterial agent (β-1,4-polyglucosamine);

[0095] Rust inhibitor (modified borate ester) 0.2 parts;

[0096] 1 part pH neutralizer (triethanolamine);

[0097] 63 parts of deionized water;

[0098] The binder is a polyurethane emulsion;

[0099] The polyurethane emulsion is a mixture of modified polyurethane emulsion and waterborne polyurethane emulsion in a weight ratio of 2:1.

[0100] The modified polyurethane emulsion is a butyl acrylate modified polyurethane emulsion. The modification method is as follows: the polyurethane emulsion is first added to a dispersion vessel, heated to 40°C, an initiator and butyl acrylate are added, stirred and mixed, and the temperature is further increased to 80°C. The mixture is stirred and reacted for 2.5 hours to obtain the modified polyurethane emulsion.

[0101] The preparation method of the direct-liquid environmentally friendly ink is the same as that in Example 1.

[0102] Comparative Example 3

[0103] A direct-liquid environmentally friendly ink, comprising the following raw material components by weight:

[0104] 5 parts of edible color paste (edible brilliant blue);

[0105] 20 parts propylene glycol;

[0106] 5 parts of connector material;

[0107] 2 parts surfactant (polyoxyethylene ether phosphate);

[0108] 0.2 parts of antibacterial agent (β-1,4-polyglucosamine);

[0109] Rust inhibitor (modified borate ester) 0.2 parts;

[0110] 1 part pH neutralizer (triethanolamine);

[0111] 63 parts of deionized water;

[0112] The binder is a polyurethane emulsion;

[0113] The preparation method of the direct-liquid environmentally friendly ink is the same as that in Example 1.

[0114] Comparative Example 4

[0115] A direct-liquid environmentally friendly ink, comprising the following raw material components by weight:

[0116] 5 parts of edible color paste (edible brilliant blue);

[0117] 20 parts propylene glycol;

[0118] 5 parts of connector material;

[0119] 2 parts surfactant (polyoxyethylene ether phosphate);

[0120] 0.2 parts of antibacterial agent (β-1,4-polyglucosamine);

[0121] Rust inhibitor (modified borate ester) 0.2 parts;

[0122] 1 part pH neutralizer (triethanolamine);

[0123] 63 parts of deionized water;

[0124] The binder is a mixture of polyurethane emulsion and epoxy resin emulsion in a weight ratio of 2:3.

[0125] The polyurethane emulsion is an aqueous polyurethane emulsion.

[0126] The preparation method of the direct-liquid environmentally friendly ink is the same as that in Example 1.

[0127] Comparative Example 5

[0128] A high-performance direct-liquid environmentally friendly ink, comprising the following raw material components by weight:

[0129] 5 parts of edible color paste (edible brilliant blue);

[0130] 20 parts propylene glycol;

[0131] 5 parts of connector material;

[0132] 2 parts surfactant (polyoxyethylene ether phosphate);

[0133] 0.2 parts of antibacterial agent (β-1,4-polyglucosamine);

[0134] Rust inhibitor (modified borate ester) 0.2 parts;

[0135] 1 part pH neutralizer (triethanolamine);

[0136] 63 parts of deionized water;

[0137] The binder is a mixture of polyurethane emulsion and epoxy resin emulsion in a weight ratio of 2:3.

[0138] The polyurethane emulsion is a mixture of modified polyurethane emulsion and waterborne polyurethane emulsion in a weight ratio of 2:1.

[0139] The modified polyurethane emulsion is a butyl acrylate modified polyurethane emulsion. The modification method is as follows: the polyurethane emulsion is first added to a dispersion vessel, heated to 40°C, then azobisisovalerate and butyl acrylate are added, stirred and mixed, and the temperature is further increased to 80°C. The mixture is stirred and reacted for 2.5 hours to obtain the modified polyurethane emulsion.

[0140] A method for preparing high-performance direct-liquid environmentally friendly ink includes the following steps:

[0141] According to the formula, edible pigment, binder, propylene glycol, pH neutralizer, surfactant, antibacterial agent, rust inhibitor, and deionized water are added to the dispersion tank in sequence. After dispersion for 3 hours, the dispersion tank is subjected to negative pressure treatment at a pressure of negative 0.2 MPa to remove air bubbles and then filtered to obtain high-performance direct-liquid environmentally friendly ink.

[0142] Test case

[0143] To further verify the performance of the inks prepared in Examples 1-3 and Comparative Examples 1-5, the relevant performance indicators of the inks were first measured, and the results are shown in Table 1. Then, the inks were tested in a direct-liquid pen, as follows:

[0144] The pen tube has a diameter of 2.6 mm and the pen tip has a diameter of 0.5 mm.

[0145] 1. Drying time

[0146] Draw lines on the paper at a speed of 5 m / min and use an eraser to determine the ink drying time.

[0147] 2. Storage stability

[0148] At 25°C, the pen refill was directly exposed to the air for one month, and then the pen refill's writing performance was tested.

[0149] The pen refills were placed vertically in a 50℃ oven for 3 months to observe the number of days the refills did not leak and their leak-proof performance. At the same time, the smoothness of the pen refills' lines was tested by drawing lines on a writing circle tester.

[0150] The test results are shown in Table 2.

[0151] Table 1 Ink Performance Indicators

[0152] Group Viscosity (cps) Surface tension d / cm pH Leak-proof Coloring power % Example 1 4.5 38.9 7.6 Excellent 99.6 Example 2 4.9 39.5 7.8 Excellent 98.9 Example 3 5.2 39.2 7.8 Excellent 99.4 Comparative Example 1 3.5 39.8 7.7 generally 90.3 Comparative Example 2 4.3 38.7 7.7 better 93.5 Comparative Example 3 3.7 38.6 7.7 generally 91.6 Comparative Example 4 4.0 38.8 7.7 generally 92.7 Comparative Example 5 4.8 38.8 7.6 better 94.6

[0153] As can be seen from the results in Table 1, the ink prepared by the method of the present invention has suitable viscosity, surface tension, pH, leak-proof properties, and tinting strength, exhibiting excellent overall performance. In contrast, the inks in Comparative Examples 1-4, which did not use the novel binder of the present invention, all showed a significant decrease in performance, indicating that the novel binder of the present invention can effectively improve the overall performance of the ink.

[0154] Table 2 Performance Tests of Direct-Liquid Pen Leads

[0155]

[0156] As can be seen from the results in Table 2, the ink prepared by the formula and preparation method of this invention, when made into a direct-liquid pen refill, dries and forms a film quickly after writing, effectively preventing ink leakage. After being placed vertically in an oven at 50°C for 3 months, the remaining ink content is still above 99%, demonstrating strong resistance to drying and leakage. At the same time, the ink flow is good when starting to write again, and the writing performance remains basically unchanged. This indicates that the ink prepared by the formula and preparation method of this invention has good film-forming properties, resistance to ink leakage, resistance to drying, and antibacterial properties, resulting in smooth and stable writing and excellent overall performance.

[0157] Finally, it should be emphasized that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high performance straight liquid environment-friendly ink, characterized in that, The raw material components include the following by weight: 5-10 parts of edible color paste, 18-25 parts of propylene glycol, 4-6 parts of binder, 0.5-2 parts of surfactant, 0.1-0.4 parts of bacteriostatic agent, 0.2-0.5 parts of anti-rust agent, 0.5-1.5 parts of pH neutralizing agent, and 60-65 parts of deionized water; The binder is a mixture of polyurethane emulsion and epoxy resin emulsion in a weight ratio of 1.5-2.5:3; The polyurethane emulsion is compounded and mixed from modified polyurethane emulsion and water-based polyurethane emulsion in a weight ratio of 2-3:1; The modified polyurethane emulsion is butyl acrylate modified polyurethane emulsion, and the modification method is as follows: the polyurethane emulsion is first added to a dispersion kettle, heated to 35-45℃, an initiator and butyl acrylate are added, stirred and mixed, and then heated to 75-95℃, and stirred and reacted for 2-3h to obtain the modified polyurethane emulsion; wherein the mass ratio of polyurethane emulsion, initiator and butyl acrylate is 1:0.01-0.1:0.3-0.

8.

2. The high performance direct liquid environmental friendly ink according to claim 1, characterized in that, The edible color paste is one or more of edible lemon yellow, edible orange yellow, edible cochineal, edible amaranth, edible indigo, and edible bright blue.

3. The high performance direct liquid environmental friendly ink according to claim 1, characterized in that, The surfactant is polyoxyethylene ether phosphate.

4. The high performance direct liquid environmental friendly ink according to claim 1, wherein, The bacteriostatic agent is any one of β-1,4-polyglucosamine, O-methylol chitosan, and trehalose.

5. The high performance direct liquid environmental friendly ink according to claim 1, wherein, The anti-rust agent is modified borate ester; and the pH neutralizing agent is one or more of triethanolamine, ammonia, sodium hydroxide, and potassium hydroxide.

6. The high performance direct liquid environmental friendly ink according to claim 5, characterized in that, The anti-rust agent is triethanolamine borate.

7. The preparation method of the high-performance direct liquid environmentally friendly ink according to any one of claims 1-6, characterized in that, The method comprises the following steps: S1. According to the proportion, edible color paste, binder, propylene glycol, pH neutralizing agent, and half of the deionized water are sequentially added to a dispersion kettle, then a surfactant is added, and stirred for 1-2h to obtain a mixture; S2. The mixture obtained in S1 is added to a high-speed grinder and dispersed for 2-3h to obtain a ground material; S3. The ground material obtained in S2 is added to a dispersion kettle, then a bacteriostatic agent, an anti-rust agent, and the remaining deionized water are sequentially added, stirred uniformly, and then the dispersion kettle is subjected to negative pressure treatment, filtered after removing bubbles, and a high-performance direct liquid type environment-friendly ink is obtained.

8. The method for preparing a high-performance direct-liquid environmentally friendly ink according to claim 7, characterized in that, In S2, the speed of high-speed grinding is 2500-3000r / min.

9. The method for preparing a high-performance direct-liquid environmentally friendly ink according to claim 7, characterized in that, In S3, the pressure of negative pressure treatment is -0.1MPa.

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