Environmentally friendly offset printing ink and preparation method thereof

Abstract

The invention belongs to the technical field of offset printing ink, and specifically relates to an environmentally friendly offset printing ink and a preparation method thereof. The offset printing ink comprises the following raw materials by weight: 40-50 parts of a binder; 15-20 parts of a pigment; 15-20 parts of methyl soybean oleate; 1-2 parts of an anti-wear agent; 5-8 parts of a filler; and 4-6 parts of an auxiliary agent. The prepared ink has good environmental protection, low VOC content, high tinting power, good fluidity, fast fixing speed, good printing effect, and good antibacterial and mildew-proof effects, thereby preventing the ink from being contaminated by microorganisms during production, storage, and use.

Description

Technical Field

[0001] The invention belongs to the technical field of offset printing ink, and in particular relates to an environmentally friendly offset printing ink and a preparation method thereof. Background Art

[0002] The main components of ink are binders and colorants. The binder is the most important component of ink. It can disperse the colorant into the ink and give the ink properties such as fluidity, drying properties and viscosity. The binder of traditional offset ink uses mineral oil as a solvent, which will release VOCs and cause environmental pollution. In order to alleviate the impact of the oil crisis and reduce environmental pollution, the use of environmentally friendly binders instead of mineral oil binders to prepare environmentally friendly inks has become a new development trend. Among them, environmentally friendly inks include water-based inks, UV inks and plant-based inks. Among them, plant-based inks have the advantages of low cost, good oil solubility and stable performance. The most commonly used vegetable oil in plant-based inks is soybean oil. Soybean oil is a renewable resource, cheaper than other vegetable oils, and has a large yield. After decomposition, it can be completely integrated into the natural environment, has excellent environmental protection, and the obtained ink has a good printing effect. However, soybean oil has poor drying properties, resulting in poor performance when used as a binder, which in turn affects the use effect of the ink.

[0003] In order to improve the drying property of soybean oil and obtain soybean oil ink with better performance, soybean oil is usually modified; the patent with application number 201910065415.X discloses a quick-drying environmentally friendly soybean offset ink and a preparation method, in which 1,4-pentadiene-3-ol is used to chemically modify soybean oil so that the soybean oil molecular structure has more reactive double bonds, which is easier to react with oxygen in the air to form an ink film, thereby significantly improving the drying property of the soybean ink. However, the VOC content of the soybean ink finally obtained is relatively high, reaching 10-12%, and there is still room for improvement in its environmental performance; the patent with application number 202210281503.5 discloses a vegetable oil-based low-halogen environmentally friendly ink and a preparation method thereof, which uses soybean oil fatty acids and methyl methacrylate to obtain a quick-drying environmentally friendly soybean offset ink and a preparation method thereof. A modified short oil alkyd resin is prepared by double bond copolymerization method with n-butyl ester, refined soybean oil, glycerol, phthalic anhydride, lithium hydroxide and initiator as raw materials. The modified short oil alkyd resin has excellent self-drying property. The modified short oil alkyd resin is put into the preparation process of the binder by a two-step method. The prepared binder gives the ink excellent flow and printing ability, makes the ink film high gloss and friction resistance. The final ink is green and environmentally friendly, low in halogen, and has a MOSH&MOAH content of <1%. It is suitable for various offset printing machines, but its function is single and it is not suitable for preparing printed products that are in direct contact with the human body and need to have a certain antibacterial effect. Therefore, it is urgent to develop a vegetable oil type ink with antibacterial function and good environmental protection to meet market demand. Summary of the invention

[0004] In order to solve the above problems, the present invention provides an environmentally friendly offset printing ink and a preparation method thereof. The prepared ink has good environmental performance, low VOC content, high tinting strength, good fluidity, fast fixing speed, good printing effect, and also has good antibacterial and mildew-proof effects, thereby preventing the ink from being contaminated by microorganisms during production, storage and use.

[0005] The technical solution adopted by the present invention to solve the above problems is:

[0006] The invention discloses an environmentally friendly offset printing ink, which comprises the following raw materials in parts by weight: 40-50 parts of a binder; 15-20 parts of a pigment; 15-20 parts of soybean methyl ester; 1-2 parts of an anti-wear agent; 5-8 parts of a filler; and 4-6 parts of an auxiliary agent. The binder is composed of the following raw materials in parts by weight: 30-40 parts of rosin-modified phenolic resin; 20-30 parts of modified soybean oil; 15-20 parts of epoxy soybean oil propylene glycol ester; 5-10 parts of linseed oil; and 0.4-0.6 parts of aluminum distearate. The auxiliary agent is composed of propylene glycol and modified nano zinc oxide in a mass ratio of 3-5:1, wherein the propylene glycol evaporates slowly and can improve the adhesion of the ink, and the modified nano zinc oxide is used as an ink drying agent.

[0007] Furthermore, the wear-resistant agent is any one of polyethylene wax, polypropylene wax and polyamide wax.

[0008] Furthermore, the filler is any one of calcium carbonate, magnesium carbonate, barium sulfate and aluminum silicate.

[0009] Furthermore, the preparation method of the modified soybean oil is: add EDC hydrochloride and carboxymethyl chitosan aqueous solution to soybean oil, mix evenly, heat to 60-70°C under nitrogen protection, react for 4-6 hours, and obtain modified soybean oil after the reaction is completed; the mass ratio of the soybean oil, carboxymethyl chitosan, and EDC hydrochloride is 1:0.4-0.5:0.05-0.1.

[0010] Furthermore, the preparation method of the modified nano zinc oxide is as follows: S1, adding nano zinc oxide to ethanol and water, dispersing evenly, adding 3-aminopropyltriethoxysilane dropwise, reacting at 60-70° C. for 1-2 hours, centrifuging after the reaction is completed, taking the precipitate and drying it to obtain amino nano zinc oxide; the mass ratio of ethanol to water is 1:1.5-2; the mass ratio of nano zinc oxide to 3-aminopropyltriethoxysilane is 10:0.2-0.3;

[0011] S2, add amination nano zinc oxide to ethanol, disperse it evenly, add epichlorohydrin dropwise, react at 40-50°C for 4-5h, then add dodecyl dimethyl tertiary amine, heat to 78-80°C, reflux for 8-10h, centrifuge after the reaction is complete, take the precipitate and dry it to obtain hydroxylated nano zinc oxide; the ratio of amination nano zinc oxide, epichlorohydrin, and dodecyl dimethyl tertiary amine is 1:0.4-0.5:0.8-1;

[0012] S3. Add hydroxylated nano zinc oxide to ethanol and disperse it evenly. Add N,N'-carbonyldiimidazole and react at room temperature for 4-6 hours. Add carboxymethyl chitosan aqueous solution and heat to 40-50°C for 10-12 hours. After the reaction is completed, centrifuge and wash the precipitate with water and ethanol in turn. After drying, obtain modified zinc oxide. The mass ratio of hydroxylated nano zinc oxide, N,N'-carbonyldiimidazole and carboxymethyl chitosan is 1:0.6-0.8:1-1.5.

[0013] The present invention also provides a method for preparing an environmentally friendly offset printing ink, comprising the following steps: mixing a connecting material, a pigment, methyl soybean oleate, an anti-wear agent, a filler and an auxiliary agent uniformly according to a weight ratio, and grinding the mixture until the fineness of the ink is less than 10 μm to obtain the offset printing ink.

[0014] Furthermore, the preparation method of the connecting material is as follows: rosin-modified phenolic resin, modified soybean oil, propylene glycol epoxy soybean oil, and linseed oil are mixed uniformly according to a weight ratio, kept warm at 200-220° C. for 0.5-1 h, cooled to room temperature, and aluminum distearate is added, mixed thoroughly, and the connecting material is obtained.

[0015] The present invention has the following beneficial effects:

[0016] The present invention utilizes the condensation reaction of the carboxyl group in soybean oil and the amino group of carboxymethyl chitosan to graft the carboxymethyl chitosan onto the molecular structure of soybean oil. The carboxymethyl chitosan with antibacterial effect gives the modified soybean oil a good antibacterial effect, and can also adjust the viscosity and improve the adhesion of the ink. In order to improve the dispersibility of nano zinc oxide, the present invention modifies it. The nano zinc oxide is used as a raw material, and reacts with 3-aminopropyl triethoxysilane, epichlorohydrin, dodecyl dimethyl tertiary amine and carboxymethyl chitosan in sequence to obtain a modified nano zinc oxide containing long-chain quaternary ammonium salt and carboxymethyl chitosan on the surface. The long-chain quaternary ammonium salt gives the nano zinc oxide good dispersibility and antibacterial effect, so that it can be evenly dispersed in the ink system, prevent agglomeration, and then give full play to the effect of promoting drying, achieving a faster fixation speed, and acting together with carboxymethyl chitosan, nano zinc oxide itself and modified soybean oil to achieve multiple antibacterial effects.

[0017] The main components of the binder in the present invention are rosin-modified phenolic resin, modified soybean oil, epoxy soybean oil propylene glycol ester and linseed oil, all of which are easily decomposable plant-based raw materials, have good environmental protection and low VOC content; propylene glycol and modified nano zinc oxide are used as auxiliary agents, the modified nano zinc oxide has good dispersibility in the ink, can promote drying, and can also synergistically act with the modified soybean oil to improve the adhesion and antibacterial properties of the ink, and successfully prepares an ink with high tinting power, good fluidity, fast fixing speed and good printing effect, and also has good antibacterial and mildew-proof effects, thereby preventing the ink from being contaminated by microorganisms during production, storage and use. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] In the technical scheme of the present invention, the raw materials used in the following examples and comparative examples are all common commercial products, wherein the model of the rosin-modified phenolic resin is DCH2102; the pigment is the carbon black pigment model MA100; the viscosity average molecular weight of carboxymethyl chitosan is 5.0×10 3 , deacetylation degree is 90%, and carboxymethylation degree is 80%.

[0020] Example 1

[0021] An environmentally friendly offset printing ink comprises the following raw materials in parts by weight: 50 parts of a binder; 20 parts of a pigment; 20 parts of methyl soybean oleate; 1.5 parts of an anti-wear agent; 8 parts of a filler; and 6 parts of an auxiliary agent. The binder is composed of the following raw materials in parts by weight: 30 parts of rosin-modified phenolic resin; 25 parts of modified soybean oil; 15 parts of epoxy soybean oil propylene glycol ester; 5 parts of linseed oil; and 0.4 parts of aluminum distearate. The auxiliary agent is composed of propylene glycol and modified nano zinc oxide in a mass ratio of 5:1; the anti-wear agent is polyethylene wax; and the filler is calcium carbonate.

[0022] The preparation method of modified soybean oil is as follows: EDC hydrochloride and carboxymethyl chitosan aqueous solution are added to soybean oil, mixed evenly, heated to 70°C under nitrogen protection, reacted for 5 hours, and after the reaction is completed, dehydrated, filtered, and the filtrate is dried to obtain modified soybean oil; the mass ratio of soybean oil, carboxymethyl chitosan, and EDC hydrochloride is 1:0.5:0.1; the concentration of carboxymethyl chitosan in the carboxymethyl chitosan aqueous solution is 3%.

[0023] The preparation method of the connecting material is as follows: rosin-modified phenolic resin, modified soybean oil, propylene glycol epoxy soybean oil, and linseed oil are mixed uniformly according to weight ratio, kept warm at 200° C. for 1 hour, cooled to room temperature, added with aluminum distearate, and mixed thoroughly to obtain the connecting material.

[0024] The preparation method of modified nano zinc oxide is:

[0025] S1. Add nano zinc oxide to ethanol and water, disperse evenly, add 3-aminopropyltriethoxysilane dropwise, react at 70°C for 1 hour, centrifuge after the reaction is complete, take the precipitate and dry it to obtain amino nano zinc oxide; the mass ratio of ethanol to water is 1:2; the mass ratio of nano zinc oxide to 3-aminopropyltriethoxysilane is 10:0.3;

[0026] S2, add amination nano zinc oxide to ethanol, disperse it evenly, add epichlorohydrin dropwise, react at 50°C for 4h, then add dodecyl dimethyl tertiary amine, heat to 80°C, reflux for 10h, after the reaction is complete, centrifuge, take the precipitate and dry it to obtain hydroxylated nano zinc oxide; amination nano zinc oxide, epichlorohydrin, dodecyl dimethyl tertiary amine in a ratio of 1:0.5:1;

[0027] S3. Add hydroxylated nano zinc oxide to ethanol and disperse it evenly. Add N,N'-carbonyldiimidazole and react at room temperature for 6 hours. Add carboxymethyl chitosan aqueous solution and heat to 50°C for 10 hours. After the reaction is completed, centrifuge and wash the precipitate with water and ethanol in turn. After drying, obtain modified zinc oxide. The mass ratio of hydroxylated nano zinc oxide, N,N'-carbonyldiimidazole and carboxymethyl chitosan is 1:0.8:1.5. The concentration of carboxymethyl chitosan in the carboxymethyl chitosan aqueous solution is 3%.

[0028] A method for preparing an environmentally friendly offset printing ink comprises the following steps: mixing a connecting material, a pigment, methyl soybean oleate, an anti-wear agent, a filler and an auxiliary agent uniformly according to a weight ratio, and grinding the mixture until the fineness of the ink is less than 10 μm to obtain the offset printing ink.

[0029] Example 2

[0030] An environmentally friendly offset printing ink comprises the following raw materials in parts by weight: 45 parts of a binder; 15 parts of a pigment; 18 parts of methyl soybean oleate; 2 parts of an anti-wear agent; 5 parts of a filler; and 4 parts of an auxiliary agent. The binder is composed of the following raw materials in parts by weight: 40 parts of rosin-modified phenolic resin; 30 parts of modified soybean oil; 20 parts of epoxy soybean oil propylene glycol ester; 10 parts of linseed oil; and 0.6 parts of aluminum distearate. The auxiliary agent is composed of propylene glycol and modified nano zinc oxide in a mass ratio of 3:1; the anti-wear agent is polyamide wax; and the filler is barium sulfate.

[0031] The preparation method of modified soybean oil is as follows: add EDC hydrochloride and carboxymethyl chitosan aqueous solution to soybean oil, mix evenly, heat to 60°C under nitrogen protection, react for 6 hours, dehydrate, filter, and dry the filtrate to obtain modified soybean oil after the reaction is completed; the mass ratio of soybean oil, carboxymethyl chitosan, and EDC hydrochloride is 1:0.4:0.08; the concentration of carboxymethyl chitosan in the carboxymethyl chitosan aqueous solution is 3%.

[0032] The preparation method of the connecting material is as follows: rosin-modified phenolic resin, modified soybean oil, propylene glycol epoxy soybean oil and linseed oil are mixed uniformly according to weight ratio, kept warm at 220° C. for 0.5 h, cooled to room temperature, added with aluminum distearate, mixed thoroughly and uniformly to obtain the connecting material.

[0033] The preparation method of modified nano zinc oxide is:

[0034] S1. Add nano zinc oxide to ethanol and water, disperse evenly, add 3-aminopropyltriethoxysilane dropwise, react at 60°C for 2h, centrifuge after the reaction is complete, take the precipitate and dry it to obtain amino nano zinc oxide; the mass ratio of ethanol to water is 1:1.5; the mass ratio of nano zinc oxide to 3-aminopropyltriethoxysilane is 10:0.2;

[0035] S2, add amination nano zinc oxide to ethanol, disperse it evenly, add epichlorohydrin dropwise, react at 40°C for 5h, then add dodecyl dimethyl tertiary amine, heat to 78°C, reflux for 9h, after the reaction is complete, centrifuge, take the precipitate and dry it to obtain hydroxylated nano zinc oxide; the ratio of amination nano zinc oxide, epichlorohydrin, dodecyl dimethyl tertiary amine is 1:0.4:0.9;

[0036] S3. Add hydroxylated nano zinc oxide to ethanol and disperse it evenly. Add N,N'-carbonyldiimidazole and react at room temperature for 5 hours. Add carboxymethyl chitosan aqueous solution and heat to 40°C for 12 hours. After the reaction is completed, centrifuge and wash the precipitate with water and ethanol in turn. After drying, obtain modified zinc oxide. The mass ratio of hydroxylated nano zinc oxide, N,N'-carbonyldiimidazole and carboxymethyl chitosan is 1:0.7:1.3. The concentration of carboxymethyl chitosan in the carboxymethyl chitosan aqueous solution is 3%.

[0037] The preparation method of an environmentally friendly offset printing ink is the same as that of Example 1.

[0038] Example 3

[0039] An environmentally friendly offset printing ink comprises the following raw materials in parts by weight: 40 parts of a binder; 18 parts of a pigment; 15 parts of methyl soybean oleate; 1 part of an anti-wear agent; 6 parts of a filler; and 5 parts of an auxiliary agent. The binder is composed of the following raw materials in parts by weight: 35 parts of rosin-modified phenolic resin; 20 parts of modified soybean oil; 18 parts of epoxy soybean oil propylene glycol ester; 8 parts of linseed oil; and 0.5 parts of aluminum distearate. The auxiliary agent is composed of propylene glycol and modified nano zinc oxide in a mass ratio of 4:1; the anti-wear agent is polypropylene wax; and the filler is aluminum silicate.

[0040] The preparation method of modified soybean oil is as follows: EDC hydrochloride and carboxymethyl chitosan aqueous solution are added to soybean oil, mixed evenly, heated to 65°C under nitrogen protection, reacted for 4 hours, and after the reaction is completed, dehydrated, filtered, and the filtrate is dried to obtain modified soybean oil; the mass ratio of soybean oil, carboxymethyl chitosan, and EDC hydrochloride is 1:0.45:0.05; the concentration of carboxymethyl chitosan in the carboxymethyl chitosan aqueous solution is 3%.

[0041] The preparation method of the connecting material is as follows: rosin-modified phenolic resin, modified soybean oil, propylene glycol epoxy soybean oil, and linseed oil are mixed uniformly according to weight ratio, kept warm at 210° C. for 0.8 h, cooled to room temperature, added with aluminum distearate, and mixed thoroughly to obtain the connecting material.

[0042] The preparation method of modified nano zinc oxide is:

[0043] S1. Add nano zinc oxide to ethanol and water, disperse evenly, add 3-aminopropyltriethoxysilane dropwise, react at 65°C for 1.5h, centrifuge after the reaction is complete, take the precipitate and dry to obtain amino nano zinc oxide; the mass ratio of ethanol to water is 1:1.8; the mass ratio of nano zinc oxide to 3-aminopropyltriethoxysilane is 10:0.25;

[0044] S2, add amination nano zinc oxide to ethanol, disperse it evenly, add epichlorohydrin dropwise, react at 45°C for 5h, then add dodecyl dimethyl tertiary amine, heat to 80°C, reflux for 8h, after the reaction is complete, centrifuge, take the precipitate and dry it to obtain hydroxylated nano zinc oxide; the ratio of amination nano zinc oxide, epichlorohydrin, dodecyl dimethyl tertiary amine is 1:0.45:0.8;

[0045] S3. Add hydroxylated nano zinc oxide to ethanol and disperse it evenly. Add N,N'-carbonyldiimidazole and react at room temperature for 4 hours. Add carboxymethyl chitosan aqueous solution and heat to 45°C for 11 hours. After the reaction is completed, centrifuge and wash the precipitate with water and ethanol in turn. After drying, obtain modified zinc oxide. The mass ratio of hydroxylated nano zinc oxide, N,N'-carbonyldiimidazole and carboxymethyl chitosan is 1:0.6:1. The concentration of carboxymethyl chitosan in the carboxymethyl chitosan aqueous solution is 3%.

[0046] The preparation method of an environmentally friendly offset printing ink is the same as that of Example 1.

[0047] Example 4

[0048] An environmentally friendly offset printing ink comprises the following raw materials in parts by weight: 40 parts of a binder; 20 parts of a pigment; 15 parts of methyl soybean oleate; 2 parts of an anti-wear agent; 5 parts of a filler; and 5 parts of an auxiliary agent. The binder is composed of the following raw materials in parts by weight: 40 parts of rosin-modified phenolic resin; 25 parts of modified soybean oil; 18 parts of epoxy soybean oil propylene glycol ester; 7 parts of linseed oil; and 0.5 parts of aluminum distearate. The auxiliary agent is composed of propylene glycol and modified nano zinc oxide in a mass ratio of 3:1; the anti-wear agent is polyethylene wax; and the filler is magnesium carbonate.

[0049] The preparation method of modified soybean oil is as follows: EDC hydrochloride and carboxymethyl chitosan aqueous solution are added to soybean oil, mixed evenly, heated to 60°C under nitrogen protection, reacted for 5 hours, and after the reaction is completed, dehydrated, filtered, and the filtrate is dried to obtain modified soybean oil; the mass ratio of soybean oil, carboxymethyl chitosan, and EDC hydrochloride is 1:0.5:0.05; the concentration of carboxymethyl chitosan in the carboxymethyl chitosan aqueous solution is 3%.

[0050] The preparation method of the connecting material is the same as that of Example 1.

[0051] The preparation method of modified nano zinc oxide is:

[0052] S1, the same as step S1 in Example 1;

[0053] S2, add amination nano zinc oxide to ethanol, disperse it evenly, add epichlorohydrin dropwise, react at 40°C for 4h, then add dodecyl dimethyl tertiary amine, heat to 80°C, reflux for 8h, after the reaction is complete, centrifuge, take the precipitate and dry it to obtain hydroxylated nano zinc oxide; the ratio of amination nano zinc oxide, epichlorohydrin, dodecyl dimethyl tertiary amine is 1:0.4:1;

[0054] S3. Add hydroxylated nano zinc oxide to ethanol and disperse it evenly. Add N,N'-carbonyldiimidazole and react at room temperature for 5 hours. Add carboxymethyl chitosan aqueous solution and heat to 40°C for 10 hours. After the reaction is completed, centrifuge and wash the precipitate with water and ethanol in turn. After drying, obtain modified zinc oxide. The mass ratio of hydroxylated nano zinc oxide, N,N'-carbonyldiimidazole and carboxymethyl chitosan is 1:0.6:1.5. The concentration of carboxymethyl chitosan in the carboxymethyl chitosan aqueous solution is 3%.

[0055] The preparation method of an environmentally friendly offset printing ink is the same as that of Example 1.

[0056] Comparative Example 1

[0057] An environmentally friendly offset printing ink comprises the following raw materials in parts by weight: 50 parts of a binder; 20 parts of a pigment; 20 parts of methyl soybean oleate; 1.5 parts of an anti-wear agent; 8 parts of a filler; and 6 parts of an auxiliary agent. The binder is composed of the following raw materials in parts by weight: 30 parts of rosin-modified phenolic resin; 25 parts of soybean oil; 15 parts of epoxidized soybean oil propylene glycol ester; 5 parts of linseed oil; and 0.4 parts of aluminum distearate. The auxiliary agent is composed of propylene glycol and modified nano zinc oxide in a mass ratio of 5:1; the anti-wear agent is polyethylene wax; and the filler is calcium carbonate.

[0058] The preparation methods of the connecting material, modified nano zinc oxide and environmentally friendly offset printing ink are the same as those in Example 1.

[0059] Comparative Example 2

[0060] An environmentally friendly offset printing ink comprises the following raw materials in parts by weight: 50 parts of a binder; 20 parts of a pigment; 20 parts of methyl soybean oleate; 1.5 parts of an anti-wear agent; 8 parts of a filler; and 6 parts of an auxiliary agent. The binder is composed of the following raw materials in parts by weight: 30 parts of rosin-modified phenolic resin; 25 parts of modified soybean oil; 15 parts of epoxy soybean oil propylene glycol ester; 5 parts of linseed oil; and 0.4 parts of aluminum distearate. The auxiliary agent is composed of propylene glycol and hydroxylated nano zinc oxide in a mass ratio of 5:1; the anti-wear agent is polyethylene wax; and the filler is calcium carbonate.

[0061] The preparation method of modified soybean oil, connecting material, hydroxylated nano zinc oxide and environmentally friendly offset printing ink is the same as that in Example 1.

[0062] Comparative Example 3

[0063] An environmentally friendly offset printing ink comprises the following raw materials in parts by weight: 50 parts of a binder; 20 parts of a pigment; 20 parts of methyl soybean oleate; 1.5 parts of an anti-wear agent; 8 parts of a filler; and 6 parts of an auxiliary agent. The binder is composed of the following raw materials in parts by weight: 30 parts of rosin-modified phenolic resin; 25 parts of modified soybean oil; 15 parts of epoxy soybean oil propylene glycol ester; 5 parts of linseed oil; and 0.4 parts of aluminum distearate. The auxiliary agent is composed of propylene glycol and nano zinc oxide in a mass ratio of 5:1; the anti-wear agent is polyethylene wax; and the filler is calcium carbonate.

[0064] The preparation method of modified soybean oil, binder and environmentally friendly offset printing ink is the same as that in Example 1.

[0065] Related tests

[0066] The basic performance tests of the inks prepared in Examples 1-4 and Comparative Examples 1-3 were carried out, wherein the tinting strength was tested with reference to the standard GB / T13217.1-2020 "Test Method for Color and Tinting Strength of Ink"; at a temperature of 25°C and a humidity of 60-70%, a viscosity meter was used to measure the viscosity value at 400rpm, 32°C, and 60s; a flowability meter was used to measure the fluidity; at a temperature of 25°C and a humidity of 60-70%, after the printing adaptor was developed, the fixing speed was measured by a fixing speed measuring machine; the VOC content of the ink was determined with reference to the standard GB38507-2020 "Limits of Volatile Organic Compounds (VOCs) in Ink"; and the VOC content of the ink was determined with reference to GB / T 13217.7-2023 "Ink Adhesion Test Method" tests the adhesion of the ink; Printing effect test: The ink is printed with a high-speed rotary printing press at a speed of 200m / min, and Chinese characters and numbers are printed in Chinese font size 8 on ordinary A4 paper. The print quality is evaluated by its clarity, where A represents clear and smooth lines, B represents relatively clear and slightly thick lines, and C represents rough edges and blur; the test results are shown in Table 1.

[0067] Table 1 Basic performance test results of ink

[0068]

[0069]

[0070] It can be seen from the results in Table 1 that the inks of Examples 1-4 have high tinting power, good fluidity, fast fixing speed, low VOC content, good adhesion and printing effect, indicating that their basic performance is good; compared with Comparative Examples 1-3, the carboxymethyl chitosan grafted on the molecular structure of the modified soybean oil in the connecting material in Example 1 of the present invention can adjust the viscosity and improve the adhesion of the ink; the auxiliary agent is composed of propylene glycol and modified nano zinc oxide, wherein propylene glycol evaporates slowly, which improves the adhesion of the ink, and the surface of the modified nano zinc oxide contains a long-chain quaternary ammonium salt, which has a good dispersing effect and can be evenly dispersed in the ink system to prevent agglomeration, thereby giving full play to the role of promoting drying, achieving a faster fixing speed, and the carboxymethyl chitosan contained on the surface of the modified nano zinc oxide works together with propylene glycol and modified soybean oil to improve the adhesion of the ink, thereby achieving a good printing effect.

[0071] The antibacterial properties of the inks prepared in Examples 1-4 and Comparative Examples 1-3 were tested, wherein the culture medium was nutrient agar, the bacterial species were Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Aspergillus niger, and the bacterial suspensions were prepared at a concentration of 2.0×10 6 mL, 0.5 g ink was added to the bacterial suspension, cultured at 37°C for 24 h, and the size of the inhibition zone was detected; the results are shown in Table 2.

[0072] Table 2 Test results of antibacterial properties of ink

[0073]

[0074]

[0075] From the results in Table 2, it can be seen that the diameters of the antibacterial zones of the inks of Examples 1-4 are all larger than those of Comparative Examples 1-3, indicating that they have good antibacterial effects on Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Aspergillus niger; compared with Comparative Examples 1-3, in Example 1 of the present invention, carboxymethyl chitosan with antibacterial effect is grafted onto the molecular structure of the modified soybean oil in the binder, and long-chain quaternary ammonium salt and carboxymethyl chitosan with antibacterial effect are grafted onto the surface of the modified nano zinc oxide in the auxiliary agent, and the nano zinc oxide itself also has a certain antibacterial effect. The three work together to play an antibacterial role, achieving a good antibacterial effect, giving the ink a good antibacterial and mildew-proof effect, and avoiding microbial contamination of the ink during production, storage and use.

[0076] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or device; although the embodiments of the present application have been shown and described, it can be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An environmentally friendly offset printing ink, characterized in that: The offset printing ink comprises the following raw materials in parts by weight: 40-50 parts of a binder; 15-20 parts of a pigment; 15-20 parts of methyl soybean oleate; 1-2 parts of an anti-wear agent; 5-8 parts of a filler; and 4-6 parts of an auxiliary agent. The binder is composed of the following raw materials in parts by weight: 30-40 parts of rosin-modified phenolic resin; 20-30 parts of modified soybean oil; 15-20 parts of epoxy soybean oil propylene glycol ester; 5-10 parts of linseed oil; and 0.4-0.6 parts of aluminum distearate. The auxiliary agent is composed of propylene glycol and modified nano zinc oxide in a mass ratio of 3-5:

1. The preparation method of the modified soybean oil is as follows: add EDC hydrochloride and carboxymethyl chitosan aqueous solution to soybean oil, mix evenly, heat to 60-70° C. under nitrogen protection, react for 4-6 hours, and obtain modified soybean oil after the reaction is completed; The preparation method of the modified nano zinc oxide is: S1. Add nano zinc oxide to ethanol and water, disperse evenly, add 3-aminopropyltriethoxysilane dropwise, react at 60-70°C for 1-2h, centrifuge after the reaction is complete, take the precipitate and dry it to obtain amino nano zinc oxide; S2, add amination nano zinc oxide to ethanol, disperse it evenly, add epichlorohydrin dropwise, react at 40-50°C for 4-5h, then add dodecyl dimethyl tertiary amine, heat to 78-80°C, reflux for 8-10h, centrifuge after the reaction is complete, take the precipitate and dry it to obtain hydroxylated nano zinc oxide; S3, add hydroxylated nano zinc oxide to ethanol, disperse evenly, and add -Carbonyldiimidazole, react at room temperature for 4-6 hours, add carboxymethyl chitosan aqueous solution, heat to 40-50°C, react for 10-12 hours, after the reaction is completed, centrifuge, wash the precipitate with water and ethanol in turn, and dry to obtain modified zinc oxide.

2. The environmentally friendly offset printing ink according to claim 1, characterized in that: The wear-resistant agent is any one of polyethylene wax, polypropylene wax and polyamide wax.

3. The environmentally friendly offset printing ink according to claim 1, characterized in that: The filler is any one of calcium carbonate, magnesium carbonate, barium sulfate and aluminum silicate.

4. The environmentally friendly offset printing ink according to claim 1, characterized in that: In the preparation method of modified soybean oil, the mass ratio of soybean oil, carboxymethyl chitosan and EDC hydrochloride is 1:0.4-0.5:0.05-0.

1.

5. The environmentally friendly offset printing ink according to claim 1, characterized in that: In step S1, the mass ratio of ethanol to water is 1:1.5-2; the mass ratio of nano zinc oxide to 3-aminopropyltriethoxysilane is 10:0.2-0.

3.

6. The environmentally friendly offset printing ink according to claim 1, characterized in that: The hydroxylated nano zinc oxide in step S3, -The mass ratio of carbonyldiimidazole to carboxymethyl chitosan is 1:0.6-0.8:1-1.

5.

7. A method for preparing an environmentally friendly offset printing ink according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: mixing the connecting material, the pigment, methyl soybean oleate, the wear-resistant agent, the filler and the auxiliary agent uniformly according to the weight ratio, and grinding the mixture until the fineness of the ink is less than 10 micrometers to obtain the offset printing ink.

8. The method for preparing an environmentally friendly offset printing ink according to claim 7, characterized in that: The preparation method of the connecting material is as follows: rosin modified phenolic resin, modified soybean oil, propylene glycol epoxy soybean oil ester and linseed oil are mixed uniformly according to weight ratio, kept warm at 200-220° C. for 0.5-1 h, cooled to room temperature, added with aluminum distearate, and fully mixed to obtain the connecting material.

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