A flexographic water-based printing ink and a method for preparing the same

Abstract

The application discloses a kind of flexible version water-based printing ink and preparation method thereof. Specifically including the following raw materials: connecting material 30-40 parts, reinforcing filler 1-2 parts, pigment 15-20 parts, deionized water 50-60 parts, isopropanol 1-2 parts, emulsified silicone oil 0.5-1 part, ammonia 0.5-1 part and drying agent 0.5-1 part. The raw material of connecting material is polyurethane prepared by modified rosin and diisocyanate, and end-capping is carried out, and the modified rosin provides good rigidity, corrosion resistance, waterproof and insulation and other advantages for ink, and benzimidazole end-capping increases the chemical stability of resin and the bonding strength of metal interface. Reinforcing filler is based on nano calcium carbonate, which improves the toughness of ink, so that the ink is not easy to crack, and the introduction of hindered amine and quaternary ammonium salt structure makes the ink more resistant to oxidation and bacterial decomposition.

Description

Technical Field

[0001] The invention relates to the field of printing ink preparation, and in particular to a flexographic water-based printing ink and a preparation method thereof. Background Art

[0002] Ink is a key material used in printing, creating designs and text on substrates through printing or inkjet printing. Ink consists of primary and secondary ingredients, which are uniformly mixed and repeatedly rolled to form a viscous, colloidal fluid. It is composed of binders (resins), pigments, fillers, additives, and solvents. It is used in a variety of printing applications, including books, packaging, architectural decoration, and electronic circuit boards. Because water-based printing inks use water as a solvent, they offer improved environmental performance compared to organic solvent-based inks. They contain no aromatic hydrocarbon solvents and significantly reduce VOCs. However, water-based inks have poorer adhesion than solvent-based inks. Outdoors, water-based inks can be corroded by acids and alkalis, degraded by ultraviolet rays, and degraded by bacteria. Harmful bacteria such as Staphylococcus aureus and Escherichia coli on public products can increase the risk of contact transmission and cross-infection. Therefore, it is crucial to provide a water-based ink with strong adhesion, environmental resistance, and antibacterial properties. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for preparing a flexographic water-based printing ink, which solves the problems of poor adhesion and poor stability of current water-based printing inks.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A method for preparing a flexographic water-based printing ink comprises the following steps:

[0006] Weigh the following raw materials in parts by weight: 30-40 parts binder, 1-2 parts reinforcing filler, 15-20 parts pigment, 50-60 parts deionized water, 1-2 parts isopropyl alcohol, 0.5-1 part silicone emulsifier, 0.5-1 part ammonia water, and 0.5-1 part desiccant. Add the raw materials to a high-speed ink dispenser and stir at a speed of 150-180 rpm and a temperature of 90-110°C for 10-12 hours to produce a flexographic water-based printing ink.

[0007] The pigment is a mixture of one or more of phthalocyanine green, phthalocyanine blue or phthalocyanine red in any proportion, and the desiccant is a mixture of one or more of red drying oil and white drying oil in any proportion.

[0008] Furthermore, the connecting material is prepared by the following steps:

[0009] Step A1: The rosin, p-aminobenzenesulfonic acid, toluene and p-toluenesulfonic acid were mixed uniformly, and reacted at a rotation speed of 80-100 rpm and a temperature of 70-80 °C for 2-3 h to obtain intermediate 1. The intermediate 1, butenediol and toluene were mixed uniformly, and reacted at a rotation speed of 100-120 rpm and a temperature of 50-60 °C for 2-3 h to obtain intermediate 2.

[0010] Step A2: The intermediate 2, isophorone diisocyanate, acetone and dibutyltin dilaurate were mixed uniformly, and reacted at a rotation speed of 220-250 rpm and a temperature of 100-120 °C for 3-5 h. N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid was added, and reacted at a rotation speed of 250-280 rpm and a temperature of 100-120 °C for 5-8 h to obtain a prepolymer. The prepolymer, 1H-benzimidazol-5-ol and acetonitrile were mixed uniformly, and reacted at a rotation speed of 120-150 rpm and a temperature of 90-110 °C for 6-8 h to obtain the sizing agent.

[0011] Further, the rosin, p-aminobenzenesulfonic acid and toluene in step A1 were used in a ratio of 1 g:0.5 g:12 mL, and the p-toluenesulfonic acid was used in an amount of 2% of the amount of rosin. The intermediate 1, butenediol and toluene were used in a ratio of 1 g:0.2 g:10 mL.

[0012] Further, the intermediate 2, isophorone diisocyanate, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid and acetone in step A2 were used in a ratio of 1 g:2.4 g:0.5 g:20 mL, and the dibutyltin dilaurate was used in an amount of 2% of the mass of the intermediate 2. The prepolymer 2, 1H-benzimidazol-5-ol and acetonitrile were used in a ratio of 1 g:0.1 g:12 mL.

[0013] Further, the reinforcing filler was prepared by the following steps:

[0014] Step B1: The nano calcium carbonate was dispersed in deionized water, and ethanol and KH550 were added. The mixture was stirred at a rotation speed of 100-120 rpm and a temperature of 50-60 °C for 1-2 h to obtain a precursor 1. The precursor 1, propylene oxide, dimethylformamide and sulfuric acid were mixed uniformly, and reacted at a rotation speed of 90-110 rpm and a temperature of 60-80 °C for 2-3 h to obtain a precursor 2.

[0015] Step B2: Mix precursor 2, 1-chlorononane and acetonitrile evenly, and react at a speed of 80-100 rpm and a temperature of 70-80°C for 2-3 hours to obtain precursor 3. Mix precursor 3, 4-amino-2,2,6,6-tetramethylpiperidine and dimethylformamide evenly, and react at a speed of 100-120 rpm and a temperature of 60-80°C for 1-2 hours to obtain a reinforcing filler.

[0016] Furthermore, the usage ratio of nano-calcium carbonate, deionized water, ethanol and KH550 in step B1 is 1 g:30 mL:20 mL:5 mL, the usage ratio of precursor 1, propylene oxide dimethyl formamide and sulfuric acid is 1 g:0.8 g:10 mL:2 mL, and the concentration of sulfuric acid is 80%.

[0017] Furthermore, in step B2, the amount ratio of the precursor 2, 1-chlorononane and acetonitrile is 1g:8g:50mL, and the amount ratio of the precursor 3, 4-amino-2,2,6,6-tetramethylpiperidine and dimethylformamide is 1g:20g:100mL.

[0018] Beneficial effects of the present invention:

[0019] The present invention discloses a method for preparing a water-based printing ink, which specifically includes the following raw materials: a binder, a reinforcing filler, a pigment, deionized water, isopropyl alcohol, a defoaming agent, a neutralizer, and a desiccant. The binder is made of rosin, which can serve as a color carrier and enhance the ink's adhesion to paper. Rosin is a compound with a phenanthrene ring structure, and therefore has the advantages of strong rigidity, corrosion resistance, water resistance, and good insulation properties. Rosin is modified to eliminate active groups, and a water-based sulfonic acid group and two hydroxyl groups that can react with isocyanate groups are introduced. Through a polyurethane reaction, a sulfonic acid chain extender is used and a benzimidazole compound is used to cap the polyurethane. The polyurethane has excellent properties such as high strength, good toughness, wear resistance, and oil resistance. Compared with carboxylic acid chain extenders, sulfonic acid chain extenders have higher ionization, better thermal stability, and stronger hydrophilicity, thereby increasing the water content of the resin. Benzimidazole derivatives, containing two nitrogen atoms in the molecule, can be physically adsorbed on metal surfaces, improving the bonding effect at the resin-metal interface. The reinforcing filler is made of nano-calcium carbonate. Nano-calcium carbonate can improve the toughness of the ink and prevent the ink from cracking. At the same time, nano-calcium carbonate has good dispersibility. The nano-calcium carbonate is used to introduce a long-chain quaternary ammonium salt structure and a hindered amine structure into the ink. The long-chain quaternary ammonium salt can interact with the anionic groups on the cell membrane, and the long-chain alkyl group can be inserted into the lipid layer of the bacterial cell, changing the permeability of the cell membrane, destroying the membrane structure, and causing the bacterial cell to die, thereby improving the antibacterial ability of the ink and preventing bacteria from decomposing the ink. The hindered amine can prevent and inhibit the chain initiation reaction and chain growth reaction by capturing oxygen free radicals, thereby terminating the free radical chain reaction and achieving antioxidant ability. The binder is the main component of the ink. Improving the stability of the binder is the main method for improving the performance of the ink. The water-based printing ink disclosed by the present invention has high strength and chemical corrosion resistance. The reinforcing filler gives the water-based ink the ability to resist microbial decomposition and oxidation. Multiple effects work together to greatly improve the stability of the ink.

[0020] The connecting material uses rosin as a raw material. The carboxyl group of the rosin and the amino group of p-aminomethanesulfonic acid undergo amidation reaction under the action of p-toluenesulfonic acid to obtain intermediate 1. The conjugated double bond of the intermediate 1 and the double bond of butenediol undergo DA reaction to obtain intermediate 2. The hydroxyl group of the intermediate 2 and the isocyanate group of excess isophorone diisocyanate react under the action of dibutyltin dilaurate. The blocked isocyanate group continues to undergo chain extension with the amino group of N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid to obtain a prepolymer. The isocyanate group of the prepolymer reacts with the hydroxyl group of 1H-benzimidazole-5-ol to obtain the connecting material.

[0021] The reinforcing filler uses nano-calcium carbonate as a raw material, and the nano-calcium carbonate is surface-modified to obtain a precursor 1. The amino group of the precursor 1 and the epoxy group of propylene oxide react under the catalytic action of sulfuric acid to generate a tertiary amino group and a hydroxyl group to obtain a precursor 2. The tertiary amino group of the precursor 2 further reacts with 1-chlorononane to obtain a Menschutkin reaction to obtain a precursor 3. The hydroxyl group of the precursor 3 further reacts with the amino group of 4-amino-2,2,6,6-tetramethylpiperidine to generate carbamate to obtain a reinforcing filler. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0023] Example 1

[0024] A method for preparing a flexographic water-based printing ink comprises the following steps:

[0025] Weigh the following raw materials in parts by weight: 30 parts binder, 1 part reinforcing filler, 15 parts pigment, 50 parts deionized water, 1 part isopropyl alcohol, 0.5 part silicone emulsifier, 0.5 part ammonia solution, and 0.5 part desiccant. Add these raw materials to a high-speed ink dispenser and stir at 150 rpm and 90°C for 10 hours to prepare a flexographic water-based printing ink.

[0026] The pigment is a mixture of phthalocyanine green and phthalocyanine blue in a ratio of 1:1, the emulsified silicone oil is DF-2545 produced by Dongguan Defeng Defoaming Agent Co., Ltd., and the desiccant is red desiccant oil.

[0027] The connecting material is prepared by the following steps:

[0028] Step A1: Rosin, p-aminobenzenesulfonic acid, toluene and p-toluenesulfonic acid were mixed uniformly, and the mixture was reacted at a speed of 80 rpm and a temperature of 70°C for 2 h to obtain intermediate 1. Intermediate 1, butene glycol and toluene were mixed uniformly, and the mixture was reacted at a speed of 100 rpm and a temperature of 50°C for 2 h to obtain intermediate 2.

[0029] Step A2: Intermediate 2, isophorone diisocyanate, acetone and dibutyltin dilaurate were mixed uniformly, and reacted at 100 ℃ for 3 h at 220 rpm, and N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid was added, and reacted at 100 ℃ for 5 h at 250 rpm to obtain a prepolymer, and the prepolymer, 1H-benzimidazole-5-ol and acetonitrile were mixed uniformly, and reacted at 90 ℃ for 6 h at 120 rpm to obtain the adhesive.

[0030] The amount of the rosin, p-aminobenzenesulfonic acid and toluene in step A1 was 1 g: 0.5 g: 12 mL, and the amount of p-toluenesulfonic acid was 2% of the amount of the rosin, and the amount of intermediate 1, butene diol and toluene was 1 g: 0.2 g: 10 mL, and the amount of the rosin was 500 g, and the amount of intermediate 1 was 520 g.

[0031] The amount of intermediate 2, isophorone diisocyanate, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid and acetone in step A2 was 1 g: 2.4 g: 0.5 g: 20 mL, and the amount of dibutyltin dilaurate was 2% of the amount of intermediate 2, and the amount of prepolymer 2, 1H-benzimidazole-5-ol and acetonitrile was 1 g: 0.1 g: 12 mL, and the amount of intermediate 2 was 520 g, and the amount of prepolymer 2 was 1000 g.

[0032] The reinforcing filler was prepared by the following steps:

[0033] Step B1: The nano calcium carbonate was dispersed in deionized water, and ethanol and KH550 were added, and stirred at 100 rpm at 50 ℃ for 1 h to obtain precursor 1, and precursor 1, propylene oxide, dimethylformamide and sulfuric acid were mixed uniformly, and reacted at 90 rpm at 60 ℃ for 2 h to obtain precursor 2.

[0034] Step B2: Precursor 2, 1-chlorononane and acetonitrile were mixed uniformly, and reacted at 80 rpm at 70 ℃ for 2 h to obtain precursor 3, and precursor 3, 4-amino-2,2,6,6-tetramethylpiperidine and dimethylformamide were mixed uniformly, and reacted at 100 rpm at 60 ℃ for 1 h to obtain the reinforcing filler.

[0035] The amount of nano calcium carbonate, deionized water, ethanol and KH550 in step B1 was 1 g: 30 mL: 20 mL: 5 mL, and the amount of precursor 1, propylene oxide, dimethylformamide and sulfuric acid was 1 g: 0.8 g: 10 mL: 2 mL, and the concentration of sulfuric acid was 80%, and the amount of nano calcium carbonate was 50 g, and the amount of precursor 1 was 50 g.

[0036] In step B2, the amount ratio of precursor 2, 1-chlorononane and acetonitrile is 1g:8g:50mL, the amount ratio of precursor 3, 4-amino-2,2,6,6-tetramethylpiperidine and dimethylformamide is 1g:20g:100mL, the amount of precursor 2 is 55g, and the amount of precursor 3 is 60g.

[0037] Example 2

[0038] A method for preparing a flexographic water-based printing ink comprises the following steps:

[0039] Weigh the following raw materials in parts by weight: 40 parts binder, 2 parts reinforcing filler, 20 parts pigment, 60 parts deionized water, 2 parts isopropyl alcohol, 1 part silicone emulsifier, 1 part ammonia solution, and 1 part desiccant. Add these raw materials to a high-speed ink dispenser and stir at 180 rpm and 110°C for 12 hours to prepare a flexographic water-based printing ink.

[0040] The pigment is a mixture of phthalocyanine red and phthalocyanine blue in a ratio of 1:1, the emulsified silicone oil is DF-2545 produced by Dongguan Defeng Defoaming Agent Co., Ltd., and the desiccant is white drying oil.

[0041] The connecting material is prepared by the following steps:

[0042] Step A1: Rosin, p-aminobenzenesulfonic acid, toluene and p-toluenesulfonic acid were mixed uniformly, and the mixture was reacted at a speed of 100 rpm and a temperature of 80°C for 3 h to obtain intermediate 1. Intermediate 1, butene glycol and toluene were mixed uniformly, and the mixture was reacted at a speed of 120 rpm and a temperature of 60°C for 3 h to obtain intermediate 2.

[0043] Step A2: Intermediate 2, isophorone diisocyanate, acetone and dibutyltin dilaurate are mixed uniformly, and the reaction is carried out at a speed of 250 rpm and a temperature of 120°C for 5 hours. N, N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid is added, and the reaction is carried out at a speed of 280 rpm and a temperature of 120°C for 8 hours to obtain a prepolymer. The prepolymer, 1H-benzimidazole-5-ol and acetonitrile are mixed uniformly, and the reaction is carried out at a speed of 150 rpm and a temperature of 110°C for 8 hours to obtain a connecting material.

[0044] The amount ratio of rosin, p-aminobenzenesulfonic acid and toluene in step A1 is 1g:0.5g:12mL, the amount of p-toluenesulfonic acid is 2% of the amount of rosin, the amount ratio of intermediate 1, butene glycol and toluene is 1g:0.2g:10mL, the amount of rosin is 500g, and the amount of intermediate 1 is 520g.

[0045] In step A2, the amount ratio of intermediate 2, isophorone diisocyanate, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid and acetone is 1g:2.4g:0.5g:20mL, the amount of dibutyltin dilaurate is 2% of the mass of intermediate 2, the amount ratio of prepolymer 2, 1H-benzimidazole-5-ol and acetonitrile is 1g:0.1g:12mL, the amount of intermediate 2 is 520g, and the amount of prepolymer 2 is 1000g.

[0046] The reinforcing filler is prepared by the following steps:

[0047] Step B1: Disperse nano-calcium carbonate in deionized water, add ethanol and KH550, and stir at a speed of 120 rpm and a temperature of 60°C for 2 hours to obtain precursor 1. Mix precursor 1, propylene oxide, dimethylformamide and sulfuric acid, and react at a speed of 110 rpm and a temperature of 80°C for 3 hours to obtain precursor 2.

[0048] Step B2: Precursor 2, 1-chlorononane and acetonitrile were mixed evenly, and the mixture was reacted at a speed of 100 rpm and a temperature of 80°C for 3 hours to obtain precursor 3. Precursor 3, 4-amino-2,2,6,6-tetramethylpiperidine and dimethylformamide were mixed evenly, and the mixture was reacted at a speed of 120 rpm and a temperature of 80°C for 2 hours to obtain a reinforcing filler.

[0049] In step B1, the amount ratio of nano-calcium carbonate, deionized water, ethanol and KH550 is 1g:30mL:20mL:5mL, the amount ratio of precursor 1, propylene oxide dimethylformamide and sulfuric acid is 1g:0.8g:10mL:2mL, the concentration of sulfuric acid is 80%, the amount of nano-calcium carbonate is 50g, and the amount of precursor 1 is 50g.

[0050] In step B2, the amount ratio of precursor 2, 1-chlorononane and acetonitrile is 1g:8g:50mL, the amount ratio of precursor 3, 4-amino-2,2,6,6-tetramethylpiperidine and dimethylformamide is 1g:20g:100mL, the amount of precursor 2 is 55g, and the amount of precursor 3 is 60g.

[0051] Example 3

[0052] A method for preparing a flexographic water-based printing ink comprises the following steps:

[0053] Weigh the following raw materials in parts by weight: 35 parts binder, 1.5 parts reinforcing filler, 18 parts pigment, 55 parts deionized water, 1.5 parts isopropyl alcohol, 0.8 parts silicone emulsifier, 0.8 parts ammonia, and 0.8 parts desiccant. Add these raw materials to a high-speed ink dispenser and stir at 165 rpm and 100°C for 11 hours to produce a flexographic water-based printing ink.

[0054] The pigment is a mixture of phthalocyanine green and phthalocyanine red in a ratio of 1:1, the emulsified silicone oil is DF-2545 produced by Dongguan Defeng Defoaming Agent Co., Ltd., and the desiccant is a mixture of red desiccant oil and white desiccant oil in a ratio of 1:1.

[0055] The connecting material is prepared by the following steps:

[0056] Step A1: Rosin, p-aminobenzenesulfonic acid, toluene and p-toluenesulfonic acid were mixed uniformly, and the mixture was reacted at a speed of 90 rpm and a temperature of 75°C for 2.5 hours to obtain intermediate 1. Intermediate 1, butene glycol and toluene were mixed uniformly, and the mixture was reacted at a speed of 110 rpm and a temperature of 55°C for 2.5 hours to obtain intermediate 2.

[0057] Step A2: Intermediate 2, isophorone diisocyanate, acetone and dibutyltin dilaurate were mixed uniformly, and the mixture was reacted at a speed of 235 rpm and a temperature of 110°C for 4 hours. N, N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid was added, and the mixture was reacted at a speed of 265 rpm and a temperature of 110°C for 6.5 hours to obtain a prepolymer. The prepolymer, 1H-benzimidazole-5-ol and acetonitrile were mixed uniformly, and the mixture was reacted at a speed of 135 rpm and a temperature of 100°C for 7 hours to obtain a connecting material.

[0058] The amount ratio of rosin, p-aminobenzenesulfonic acid and toluene in step A1 is 1g:0.5g:12mL, the amount of p-toluenesulfonic acid is 2% of the amount of rosin, the amount ratio of intermediate 1, butene glycol and toluene is 1g:0.2g:10mL, the amount of rosin is 500g, and the amount of intermediate 1 is 520g.

[0059] In step A2, the amount ratio of intermediate 2, isophorone diisocyanate, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid and acetone is 1g:2.4g:0.5g:20mL, the amount of dibutyltin dilaurate is 2% of the mass of intermediate 2, the amount ratio of prepolymer 2, 1H-benzimidazole-5-ol and acetonitrile is 1g:0.1g:12mL, the amount of intermediate 2 is 520g, and the amount of prepolymer 2 is 1000g.

[0060] The reinforcing filler is prepared by the following steps:

[0061] Step B1: Disperse nano-calcium carbonate in deionized water, add ethanol and KH550, and stir at a speed of 110 rpm and a temperature of 55°C for 1.5 hours to obtain precursor 1. Precursor 1, propylene oxide, dimethylformamide and sulfuric acid are mixed uniformly, and reacted at a speed of 100 rpm and a temperature of 70°C for 2.5 hours to obtain precursor 2.

[0062] Step B2: Precursor 2, 1-chlorononane and acetonitrile were mixed evenly, and the reaction was carried out at a speed of 90 rpm and a temperature of 75°C for 2.5 hours to obtain precursor 3. Precursor 3, 4-amino-2,2,6,6-tetramethylpiperidine and dimethylformamide were mixed evenly, and the reaction was carried out at a speed of 110 rpm and a temperature of 70°C for 1.5 hours to obtain a reinforcing filler.

[0063] In step B1, the amount ratio of nano-calcium carbonate, deionized water, ethanol and KH550 is 1g:30mL:20mL:5mL, the amount ratio of precursor 1, propylene oxide dimethylformamide and sulfuric acid is 1g:0.8g:10mL:2mL, the concentration of sulfuric acid is 80%, the amount of nano-calcium carbonate is 50g, and the amount of precursor 1 is 50g.

[0064] In step B2, the amount ratio of precursor 2, 1-chlorononane and acetonitrile is 1g:8g:50mL, the amount ratio of precursor 3, 4-amino-2,2,6,6-tetramethylpiperidine and dimethylformamide is 1g:20g:100mL, the amount of precursor 2 is 55g, and the amount of precursor 3 is 60g.

[0065] Comparative Example 1

[0066] Compared with Example 1, this comparative example uses 1,4-butanediol instead of intermediate 2, and the remaining steps are the same.

[0067] Comparative Example 2

[0068] Compared with Example 1, this comparative example did not use 1-chlorononane, and the remaining steps were the same.

[0069] Comparative Example 3

[0070] Compared with Example 1, this comparative example does not use 4-amino-2,2,6,6-tetramethylpiperidine, and the remaining steps are the same.

[0071] The flexographic water-based printing ink prepared by the present invention was applied to a CR4 grade cold-rolled carbon steel plate that complies with ISO3574, and a high-low temperature (alternating) wet heat test chamber was used to perform artificial accelerated aging tests on Examples 1-3 and Comparative Examples 1-3. This test is based on relevant test standards such as GB / T2423.2-2008, GB / T2423.1-2008, and GB / T2423.4-2008. The single aging test process is as follows: (1) The temperature is increased from room temperature to 70±2°C within 2 hours and maintained for 4 hours, and the humidity is not controlled. (2) The temperature is reduced to 25±3°C within 2 hours and maintained at a humidity of 95±3% for 4 hours. (3) The temperature is reduced from 25±3°C to -40±3°C within 2 hours and maintained for 4 hours, and the humidity is not controlled. (4) Raise the temperature to 25±3°C within 2 hours, maintain it at a humidity of 90±3% for 4 hours, set the aging time to 15d and 30d, and observe its appearance. XD-21-865 lamp aging test chamber was used to perform xenon lamp radiation accelerated aging tests on Examples 1-3 and Comparative Examples 1-3. This test is based on GB / T 16422.2-2014, and the aging experimental environment is: at a blackboard temperature of 65±3°C and an irradiance of 1.10±0.02W / m 2 The aging irradiation was carried out under 15d and 30d aging conditions, and the appearance was observed. The results are shown in Table 1:

[0072] Table 1

[0073]

[0074] According to GB / T21866-2008, a sample printed with flexographic water-based printing ink was placed on a film to ensure uniform bacterial contact. After a period of incubation, the number of viable bacteria on the sample was measured and the antibacterial rate was calculated. The test bacteria were Staphylococcus aureus and Escherichia coli. The results are shown in Table 2:

[0075] Table 2

[0076]

[0077] According to Table 1 and Table 2, the water-based ink prepared by Examples 1-3 has better environmental stability and can kill certain bacteria. Comparative Example 1 uses 1,4-butanediol instead of intermediate 2, lacks rosin structure as a color vehicle and corrosion-resistant component, causing the sample color to continue to lighten and cracks to continue to increase in weight, Comparative Example 2 does not use 1-chlorononane, lacks the bactericidal ability of quaternary ammonium salt, resulting in poor bactericidal effect, Comparative Example 3 does not use 4-amino-2,2,6,6-tetramethylpiperidine, lacks hindered phenol structure, causing the sample to continue to lighten and cracks to continue to increase in xenon lamp radiation accelerated aging test. In summary, a flexographic water-based printing ink provided by the present invention has good environmental stability and antibacterial ability.

[0078] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a flexographic water-based printing ink, characterized in that: The specific steps include: Weigh the following raw materials in parts by weight: 30-40 parts of a binder, 1-2 parts of a reinforcing filler, 15-20 parts of a pigment, 50-60 parts of deionized water, 1-2 parts of isopropyl alcohol, 0.5-1 part of an emulsified silicone oil, 0.5-1 part of aqueous ammonia, and 0.5-1 part of a desiccant; add the raw materials into a high-speed ink mixing machine and stir to prepare a flexographic water-based printing ink; The connecting material is prepared by the following steps: Step A1: rosin, p-aminobenzenesulfonic acid, toluene and p-toluenesulfonic acid are uniformly mixed and reacted to obtain intermediate 1; intermediate 1, butenediol and toluene are uniformly mixed and reacted to obtain intermediate 2; Step A2: Intermediate 2, isophorone diisocyanate, acetone, and dibutyltin dilaurate are uniformly mixed and reacted, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid is added and reacted to obtain a prepolymer, and the prepolymer, 1H-benzimidazol-5-ol, and acetonitrile are uniformly mixed and reacted to obtain a linker; In step A1, the amount ratio of rosin, p-aminobenzenesulfonic acid and toluene is 1g:0.5g:12mL, the amount of p-toluenesulfonic acid is 2% of the amount of rosin, and the amount ratio of intermediate 1, butene glycol and toluene is 1g:0.2g:10mL.

2. The method for preparing a flexographic water-based printing ink according to claim 1, wherein: The amount ratio of intermediate 2, isophorone diisocyanate, N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonic acid and acetone in step A2 is 1g: 2.4g: 0.5g: 20mL, the amount of dibutyltin dilaurate is 2% of the mass of intermediate 2, and the amount ratio of prepolymer 2, 1H-benzimidazole-5-ol and acetonitrile is 1g: 0.1g: 12mL.

3. The method for preparing a flexographic water-based printing ink according to claim 1, wherein: The reinforcing filler is prepared by the following steps: Step B1: Dispersing nano-calcium carbonate in deionized water, adding ethanol and KH550, and stirring to obtain precursor 1; uniformly mixing precursor 1, propylene oxide, dimethylformamide, and sulfuric acid, and reacting to obtain precursor 2; Step B2: Precursor 2, 1-chlorononane and acetonitrile are uniformly mixed and reacted to obtain precursor 3. Precursor 3, 4-amino-2,2,6,6-tetramethylpiperidine and dimethylformamide are uniformly mixed and reacted to obtain a reinforcing filler.

4. The method for preparing a flexographic water-based printing ink according to claim 3, wherein: In step B1, the usage ratio of nano-calcium carbonate, deionized water, ethanol and KH550 is 1 g:30 mL:20 mL:5 mL, and the usage ratio of precursor 1, propylene oxide dimethylformamide and sulfuric acid is 1 g:0.8 g:10 mL:2 mL.

5. The method for preparing a flexographic water-based printing ink according to claim 3, wherein: In step B2, the amount ratio of the precursor 2, 1-chlorononane and acetonitrile is 1 g:8 g:50 mL, and the amount ratio of the precursor 3, 4-amino-2,2,6,6-tetramethylpiperidine and dimethylformamide is 1 g:20 g:100 mL.

6. A water-based printing ink, characterized in that: Prepared according to any one of the preparation methods described in claims 1-5.

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