Cooking-resistant environment-friendly ink and preparation method thereof

Abstract

The invention discloses cooking-resistant environment-friendly ink and a preparation method thereof. The cooking-resistant environment-friendly ink is prepared from the following raw materials in parts by weight: 45 to 55 parts of sulfonic acid type waterborne polyurethane emulsion, 0.5 to 1 part of defoaming agent, 25 to 35 parts of pigment, 30 to 40 parts of filler, 3 to 5 parts of coalescing agent, 0.5 to 1 part of wear-resistant additive, 15 to 20 parts of ethanol, 15 to 20 parts of deionized water and 0.2 to 0.5 part of ammonia water. In the preparation process of the sulfonic acid type waterborne polyurethane emulsion, a synthesized fluorescent agent and a chain extender are used. The synthesized fluorescent agent comprises a carbazole structure, a double bond and an organosiloxane structure, and the stability, heat resistance, steaming and boiling resistance and mechanical properties of the fluorescence characteristic of the ink are improved. Molecules of the synthesized chain extender comprise binary hydroxyl, a sodium sulfonate salt structure and cyano, so that the solid content of the ink is increased, the drying time of the ink is shortened, the crystallization degree of polyurethane is better, and the high temperature resistance of the ink is improved.

Description

Technical Field

[0001] The invention relates to the field of inks, and in particular to a boiling-resistant and environmentally friendly ink and a preparation method thereof. Background Art

[0002] Water-based ink is recognized as an environmentally friendly, non-toxic printing ink with the advantages of high solid content, good gloss and good fluidity. It is generally composed of binders, colorants, additives and water. Waterborne polyurethane has the advantages of easy modification, low solvent emissions and low pollution. It also has good physical and chemical properties such as adhesion, wear resistance and low temperature resistance. Therefore, it is widely used in water-based ink binders. Waterborne fluorescent polyurethane ink has the excellent properties of waterborne polyurethane and is endowed with functional anti-counterfeiting properties. It has good economic value and market prospects. The traditional method is to directly mix fluorescent small molecules with waterborne polyurethane to prepare waterborne fluorescent polyurethane. However, most fluorescent small molecules have poor water solubility and poor compatibility with polymers, resulting in low stability of waterborne fluorescent polyurethane and easy migration and precipitation. In addition, most fluorescent small molecules are toxic and have a negative impact on the environment. The pollution is serious, limiting its use.

[0003] In addition, since the latent heat of volatilization of water is higher than that of organic solvents, the drying time of water-based ink is prolonged, which is not conducive to modern use. The current research focus is on increasing the solid content of water-based polyurethane to reduce the drying time. Carboxylic acid-based water-based polyurethane is more commonly used, but its thermosolid content is lower than that of sulfonic acid-based water-based polyurethane, so the development of sulfonic acid-based water-based polyurethane is of great significance. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a boiling-resistant environmentally friendly ink and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A cooking-resistant environmentally friendly ink comprises the following raw materials in parts by weight: 45-55 parts of sulfonic acid type water-based polyurethane emulsion, 0.5-1 part of defoaming agent, 25-35 parts of pigment, 30-40 parts of filler, 3-5 parts of film-forming aid, 0.5-1 part of wear-resistant aid, 15-20 parts of ethanol, 15-20 parts of deionized water and 0.2-0.5 parts of ammonia water.

[0006] The defoamer is a polyether siloxane copolymer emulsion.

[0007] The pigment is carbon black.

[0008] The filler is gas-phase nano-silicon dioxide.

[0009] The film-forming aid is a mixture of ethylene glycol methyl ether and diethylene glycol butyl ether in a mass ratio of 1:1.

[0010] The wear-resistant additive is Brazilian emulsified wax.

[0011] The volume fraction of the ethanol is 95%.

[0012] The sulfonic acid type waterborne polyurethane emulsion is prepared by the following steps: Step S1: polytetramethylene ether glycol is placed in a three-necked flask equipped with a reflux condenser, a thermometer and a stirrer, and vacuum dried at 110°C for 1 hour, then stirred, isophorone diisocyanate and dibutyltin dilaurate are added to the flask, and the temperature is raised to 90°C, stirred at a constant temperature for 3-3.2 hours, cooled to 80°C, a chain extender and acetone are added, stirred at 80°C for 3 hours to obtain a prepolymer, cooled to 70°C, hydroxyethyl acrylate and 2,6 -di-tert-butyl-p-methylphenol, react with stirring at 70°C for 1-1.5h to obtain a reaction system, wherein the amount ratio of isophorone diisocyanate, polytetramethylene ether glycol, chain extender, hydroxyethyl acrylate, dibutyltin dilaurate, acetone and 2,6-di-tert-butyl-p-methylphenol is 1.0mol: 0.17mol: 0.71mol: 0.008mol: 0.001-0.002mol: 500-550mL: 0.008-0.010mol; Step S2: adding azobisisobutyronitrile and a fluorescent agent into DMF, stirring for 10-15 minutes to obtain a mixed solution, slowly dropping the mixed solution into the above reaction system, adding acetone under stirring after the dropping is completed, heating to 80° C., stirring and reacting at a constant temperature for 6-6.5 hours, cooling to 40° C. to obtain a mixed system, transferring the mixed system into a reactor, adding deionized water for emulsification at a high-speed shear of 900 r / min, and obtaining a sulfonic acid type waterborne polyurethane emulsion, wherein the amount ratio of azobisisobutyronitrile, fluorescent agent, DMF and acetone is 0.003-0.004 mol: 0.008 mol: 50-60 mL: 600-700 mL.

[0013] The chain extender is prepared by the following steps: Step A1: Add N,N-dihydroxyethylglycine to DMF, add dithionyl chloride under stirring, reflux and stir at 50°C for 4-5h, filter, extract, and dry to obtain intermediate 1, wherein the amount ratio of N,N-dihydroxyethylglycine, DMF and dithionyl chloride is 0.1mol:150mL:0.2-0.3mol; During the reaction, N,N-dihydroxyethylglycine reacts with thionyl chloride to generate intermediate 1, the structure of which is shown below:

[0014] Step A2: 2-hydroxy-2-methyl-3-butyronitrile, potassium carbonate and dimethyl sulfoxide are added to a flask to obtain a mixed solution a, and then the intermediate 1 is added to dimethyl sulfoxide to obtain a mixed solution b. The mixed solution b is slowly added dropwise to the mixed solution a in an ice-water bath at 0°C. After the addition is completed, the temperature is raised to 40°C, and the reaction is carried out at a constant temperature for 8-10 hours. The intermediate 2 is prepared by distillation under reduced pressure. The amount ratio of the intermediate 1, 2-hydroxy-2-methyl-3-butyronitrile, potassium carbonate and dimethyl sulfoxide is 0.1 mol: 0.1 mol: 0.01-0.015 mol: 100 mL; During the reaction, 2-hydroxy-2-methyl-3-butyronitrile reacts with intermediate 1 to generate an esterification product, namely intermediate 2. The structure of intermediate 2 is shown below:

[0015] Step A3: Add intermediate 2 and ethanol aqueous solution into a flask, start stirring, then add sodium nitrite, slowly raise the temperature to 90-95°C, when the liquid in the flask boils, start to dropwise add saturated aqueous solution of sodium bisulfite, after the dropwise addition is complete, continue stirring and reacting for 3-3.5 hours to obtain a mixed solution c, cool the mixed solution to room temperature, vacuum pump for 15-20 minutes, then pour the mixed solution c into ethanol aqueous solution, precipitate, extract with ethanol, and vacuum pump for 30-40 minutes to obtain a chain extender, the amount ratio of intermediate 2, ethanol aqueous solution, sodium nitrite, and saturated aqueous solution of sodium bisulfite is 0.1 mol: 180-200 mL: 0.016 mol: 20-25 mL, the volume ratio of ethanol to water in the ethanol aqueous solution is 8:2, and the volume fraction of ethanol is 95%; During the reaction, the double bond at the end of intermediate 2 reacts with sodium bisulfate to form a sodium sulfonate organic compound, i.e., a chain extender. The chain extender molecule includes a dihydroxyl group, a sodium sulfonate salt, and a cyano group. The dihydroxyl group can react with an isocyanate group, so that the chain extender can participate in the chain extension reaction; the sodium sulfonate salt is a hydrophilic group, so that the chain extender can give the polymer hydrophilicity while extending the chain; the cyano group has a large polarity, so that the chain extender can form a large degree of hydrogen bonding with the polymer. The chain extender structure is shown below:

[0016] The fluorescent agent is prepared by the following steps: Step B1: Add 3-aminocarbazole to a flask, add dichloromethane, stir for 5-10 minutes, place the flask in a 0°C ice-water bath, quickly add isocyanoethyl methacrylate, stir for 20-25 minutes, heat to room temperature, continue stirring for 16 hours, filter, recrystallize the filter cake with anhydrous ethanol, wash the crystals with anhydrous ether, and then dry the crystals in a vacuum drying oven at room temperature for 24 hours to obtain intermediate a, wherein the amount ratio of 3-aminocarbazole, dichloromethane and isocyanoethyl methacrylate is 0.1 mol: 150 mL: 0.10-0.12 mol; During the reaction, the primary amino group of 3-aminocarbazole reacts with the isocyano group of isocyanoethyl methacrylate to generate intermediate a. The structure of intermediate a is shown below:

[0017] Step B2: Add intermediate a, (3-chloropropyl)triethoxysilane, tetra-n-butylammonium bromide, toluene and sodium hydroxide solution to a flask, stir and react at 45°C for 3-3.5h, then cool to room temperature, and stir and react at room temperature for 12h. The obtained reaction solution is divided into an upper layer and a lower layer. The upper layer is washed with deionized water, and then with saturated brine, and then dried with anhydrous sodium sulfate, concentrated, and then added with petroleum ether for recrystallization. Dichloromethane is added to the obtained crystals, and then ethanol is added to precipitate crystals. The crystals are recrystallized with anhydrous ethanol to obtain a fluorescent compound. The amount ratio of intermediate a, (3-chloropropyl)triethoxysilane, tetra-n-butylammonium bromide, toluene, sodium hydroxide solution, petroleum ether and dichloromethane is 0.03mol: 0.28-0.30mol: 0.003mol: 50mL: 50mL: 100mL: 10-12mL; During the reaction, the intermediate a, (3-chloropropyl) triethoxysilane, undergoes nitrogen alkylation reaction to generate a fluorescent agent, which contains double bonds, carbazole structures and organosiloxane structures. The carbazole structure has strong fluorescence due to the presence of a large conjugated system and strong electron transfer, which makes the fluorescent agent have strong fluorescence; the double bond allows the small molecules of the fluorescent agent to be grafted into the polymer under the action of the initiator, avoiding the migration of small molecules and causing the instability of the fluorescent properties; the organosiloxane structure improves the thermal stability of the fluorescent agent. The structure of the fluorescent agent is shown below:

[0018] Beneficial effects of the invention: The cooking-resistant environmentally friendly ink disclosed in the invention comprises raw materials of sulfonic acid type water-based polyurethane emulsion, defoamer, pigment, filler, film-forming aid, wear-resistant aid, ethanol, deionized water and ammonia water. In the preparation process of the sulfonic acid type water-based polyurethane emulsion used, a synthetic chain extender and a fluorescent agent are used. The synthesized chain extender molecule comprises a dihydroxyl group, a sodium sulfonate salt structure and a cyano group. The dihydroxyl group reacts with the isocyanate group to participate in the chain extension reaction of the polyurethane and extend the chain segment of the polyurethane; the sodium sulfonate salt is a hydrophilic group, so that the chain extender gives the polymer hydrophilicity while extending the chain, and it increases the solid content of the polyurethane and shortens the drying time of the ink; the cyano group has a large polarity, so that the chain extender can form a large degree of hydrogen bonding with the polyurethane, especially the hydrogen bonding between the hard segments of the polyurethane, so that the separation degree of the soft and hard segments becomes larger, the self-aggregation degree of the soft segment becomes larger, and a better degree of crystallization is obtained. The hydrogen bonding also increases the physical crosslinking density, and improves the wear resistance, high temperature resistance and mechanical strength of the ink.

[0019] The synthesized fluorescent agent molecules include carbazole structure, double bond and organic siloxane structure. The carbazole structure has strong fluorescence due to the presence of a large conjugated system and strong electron transfer, which makes the sulfonic acid type waterborne polyurethane emulsion have strong fluorescence and gives the ink fluorescent properties; the double bond allows the fluorescent agent small molecules to be grafted into the polyurethane under the action of the initiator to avoid the migration of small molecules and the instability of the fluorescent properties of the ink; the silanol obtained by hydrolysis of the organic silicon oxygen structure can interact with the surface hydroxyl formed by the gas-phase nano-silica as a filler in ethanol to form a cross-linked network, thereby improving the heat resistance, boiling resistance and mechanical properties of the ink. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0021] A chain extender is prepared by the following steps: Step A1: Add N,N-dihydroxyethylglycine to DMF, add dithionyl chloride under stirring, reflux and stir at 50°C for 4 hours, filter, extract, and dry to obtain intermediate 1, wherein the amount ratio of N,N-dihydroxyethylglycine, DMF and dithionyl chloride is 0.1 mol: 150 mL: 0.2 mol; Step A2: 2-hydroxy-2-methyl-3-butyronitrile, potassium carbonate and dimethyl sulfoxide are added to a flask to obtain a mixed solution a, and then the intermediate 1 is added to dimethyl sulfoxide to obtain a mixed solution b. The mixed solution b is slowly added dropwise to the mixed solution a in an ice-water bath at 0°C. After the addition is completed, the temperature is raised to 40°C, and the reaction is carried out at a constant temperature for 8 hours. The intermediate 2 is obtained by distillation under reduced pressure. The amount ratio of the intermediate 1, 2-hydroxy-2-methyl-3-butyronitrile, potassium carbonate and dimethyl sulfoxide is 0.1 mol: 0.1 mol: 0.01 mol: 100 mL; Step A3: Add intermediate 2 and ethanol aqueous solution into a flask, start stirring, then add sodium nitrite, slowly raise the temperature to 90°C, when the liquid in the flask boils, start to dropwise add a saturated aqueous solution of sodium bisulfite, after the dropwise addition is complete, continue stirring and reacting for 3 hours to obtain a mixed solution c, cool the mixed solution c to room temperature, vacuum pump for 15 minutes, then pour the mixed solution c into ethanol aqueous solution, precipitate, extract with ethanol, and vacuum pump for 30 minutes to obtain a chain extender, the amount ratio of intermediate 2, ethanol aqueous solution, sodium nitrite, and saturated aqueous solution of sodium bisulfite is 0.1 mol: 180 mL: 0.016 mol: 20 mL, the volume ratio of ethanol and water in the ethanol aqueous solution is 8: 2, and the volume fraction of ethanol is 95%. Example

[0022] A chain extender is prepared by the following steps: Step A1: Add N,N-dihydroxyethylglycine to DMF, add dithionyl chloride under stirring, reflux and stir at 50°C for 4.5h, filter, extract and dry to obtain intermediate 1, wherein the amount ratio of N,N-dihydroxyethylglycine, DMF and dithionyl chloride is 0.1mol:150mL:0.25mol; Step A2: 2-hydroxy-2-methyl-3-butyronitrile, potassium carbonate and dimethyl sulfoxide are added to a flask to obtain a mixed solution a, and then the intermediate 1 is added to dimethyl sulfoxide to obtain a mixed solution b. The mixed solution b is slowly added dropwise to the mixed solution a in an ice-water bath at 0°C. After the addition is completed, the temperature is raised to 40°C, and the reaction is carried out at a constant temperature for 9 hours. The intermediate 2 is obtained by distillation under reduced pressure. The amount ratio of the intermediate 1, 2-hydroxy-2-methyl-3-butyronitrile, potassium carbonate and dimethyl sulfoxide is 0.1 mol: 0.1 mol: 0.012 mol: 100 mL; Step A3: Add intermediate 2 and ethanol aqueous solution into a flask, start stirring, then add sodium nitrite, slowly raise the temperature to 92°C, when the liquid in the flask boils, start to dropwise add saturated aqueous solution of sodium bisulfite, after the dropwise addition is complete, continue stirring and reacting for 3.2 hours to obtain a mixed solution c, cool the mixed solution c to room temperature, vacuum pump for 18 minutes, then pour the mixed solution c into ethanol aqueous solution, precipitate, extract with ethanol, and vacuum pump for 35 minutes to obtain a chain extender, the amount ratio of intermediate 2, ethanol aqueous solution, sodium nitrite, and saturated aqueous solution of sodium bisulfite is: 0.1 mol: 190 mL: 0.016 mol: 22 mL, the volume ratio of ethanol and water in the ethanol aqueous solution is 8:2, and the volume fraction of ethanol is 95%. Example

[0023] A chain extender is prepared by the following steps: Step A1: Add N,N-dihydroxyethylglycine to DMF, add dithionyl chloride under stirring, reflux and stir at 50°C for 5h, filter, extract and dry to obtain intermediate 1, wherein the amount ratio of N,N-dihydroxyethylglycine, DMF and dithionyl chloride is 0.1mol:150mL:0.3mol; Step A2: 2-hydroxy-2-methyl-3-butyronitrile, potassium carbonate and dimethyl sulfoxide are added to a flask to obtain a mixed solution a, and then the intermediate 1 is added to dimethyl sulfoxide to obtain a mixed solution b. The mixed solution b is slowly added dropwise to the mixed solution a in an ice-water bath at 0°C. After the addition is completed, the temperature is raised to 40°C, and the reaction is carried out at a constant temperature for 10 hours. The intermediate 2 is obtained by distillation under reduced pressure. The amount ratio of the intermediate 1, 2-hydroxy-2-methyl-3-butyronitrile, potassium carbonate and dimethyl sulfoxide is 0.1 mol: 0.1 mol: 0.015 mol: 100 mL; Step A3: Add intermediate 2 and ethanol aqueous solution into a flask, start stirring, then add sodium nitrite, slowly heat up to 95°C, when the liquid in the flask boils, start to dropwise add saturated aqueous solution of sodium bisulfite, after the dropwise addition is complete, continue stirring and reacting for 3.5 hours to obtain a mixed solution c, cool the mixed solution c to room temperature, vacuum pump for 20 minutes, then pour the mixed solution c into ethanol aqueous solution, precipitate, extract with ethanol, and vacuum pump for 40 minutes to obtain a chain extender, the amount ratio of intermediate 2, ethanol aqueous solution, sodium nitrite, and saturated aqueous solution of sodium bisulfite is 0.1 mol: 200 mL: 0.016 mol: 25 mL, the volume ratio of ethanol and water in the ethanol aqueous solution is 8:2, and the volume fraction of ethanol is 95% Example

[0024] A fluorescent agent is prepared by the following steps: Step B1: Add 3-aminocarbazole to a flask, add dichloromethane, stir for 5 minutes, place the flask in an ice-water bath at 0°C, quickly add isocyanoethyl methacrylate, stir for 20 minutes, warm to room temperature, continue stirring for 16 hours, filter, recrystallize the filter cake with anhydrous ethanol, wash the crystals with anhydrous ether, and then dry the crystals in a vacuum drying oven at room temperature for 24 hours to obtain intermediate a, 3-aminocarbazole, dichloromethane and isocyanoethyl methacrylate The ratio of 0.1 mol: 150 mL: 0.10 mol; Step B2: Add intermediate a, (3-chloropropyl)triethoxysilane, tetra-n-butylammonium bromide, toluene and sodium hydroxide solution to a flask, stir and react at 45°C for 3h, then cool to room temperature, and stir and react at room temperature for 12h. The obtained reaction solution is divided into an upper layer and a lower layer. The upper layer is washed with deionized water, and then with saturated brine, and then dried with anhydrous sodium sulfate and concentrated. Then, petroleum ether is added for recrystallization. Dichloromethane is added to the obtained crystals, and then ethanol is added to precipitate crystals. The crystals are recrystallized from anhydrous ethanol to obtain a fluorescent compound. The amount ratio of intermediate a, (3-chloropropyl)triethoxysilane, tetra-n-butylammonium bromide, toluene, sodium hydroxide solution, petroleum ether and dichloromethane is 0.03mol:0.28mol:0.003mol:50mL:50mL:100mL:10mL. Example

[0025] A fluorescent agent is prepared by the following steps: Step B1: Add 3-aminocarbazole to a flask, add dichloromethane, stir for 8 minutes, place the flask in a 0°C ice-water bath, quickly add isocyanoethyl methacrylate, stir for 22 minutes, heat to room temperature, continue to stir for 16 hours, filter, recrystallize the filter cake with anhydrous ethanol, wash the crystals with anhydrous ether, and then dry the crystals in a vacuum drying oven at room temperature for 24 hours to obtain intermediate a, where the ratio of 3-aminocarbazole, dichloromethane and isocyanoethyl methacrylate is 0.1 mol: 150 mL: 0.11 mol; Step B2: Add intermediate a, (3-chloropropyl)triethoxysilane, tetra-n-butylammonium bromide, toluene and sodium hydroxide solution to a flask, stir and react at 45°C for 3.2 hours, then cool to room temperature, and stir and react at room temperature for 12 hours. The obtained reaction solution is divided into an upper layer and a lower layer. The upper layer is washed with deionized water, and then with saturated brine, and then dried with anhydrous sodium sulfate and concentrated. Then, petroleum ether is added for recrystallization. Dichloromethane is added to the obtained crystals, and then ethanol is added to precipitate crystals. The crystals are recrystallized from anhydrous ethanol to obtain a fluorescent compound. The amount ratio of intermediate a, (3-chloropropyl)triethoxysilane, tetra-n-butylammonium bromide, toluene, sodium hydroxide solution, petroleum ether and dichloromethane is 0.03 mol: 0.29 mol: 0.003 mol: 50 mL: 50 mL: 100 mL: 11 mL. Example

[0026] A fluorescent agent is prepared by the following steps: Step B1: Add 3-aminocarbazole to a flask, add dichloromethane, stir for 10 minutes, place the flask in a 0°C ice-water bath, quickly add isocyanoethyl methacrylate, stir for 25 minutes, heat to room temperature, continue to stir for 16 hours, filter, recrystallize the filter cake with anhydrous ethanol, wash the crystals with anhydrous ether, and then dry the crystals in a vacuum drying oven at room temperature for 24 hours to obtain intermediate a, the dosage ratio of 3-aminocarbazole, dichloromethane and isocyanoethyl methacrylate is: 0.1 mol: 150 mL: 0.12 mol; Step B2: Add intermediate a, (3-chloropropyl)triethoxysilane, tetra-n-butylammonium bromide, toluene and sodium hydroxide solution to a flask, stir and react at 45°C for 3.5 hours, then cool to room temperature, and stir and react at room temperature for 12 hours. The reaction solution is divided into an upper layer and a lower layer. The upper layer is washed with deionized water, and then with saturated brine. Then, it is dried with anhydrous sodium sulfate and concentrated, and then petroleum ether is added for recrystallization. Dichloromethane is added to the obtained crystals, and then ethanol is added to precipitate crystals. The crystals are recrystallized from anhydrous ethanol to obtain a fluorescent compound. The amount ratio of intermediate a, (3-chloropropyl)triethoxysilane, tetra-n-butylammonium bromide, toluene, sodium hydroxide solution, petroleum ether and dichloromethane is 0.03 mol: 0.30 mol: 0.003 mol: 50 mL: 50 mL: 100 mL: 12 mL. Example

[0027] A cooking-resistant environmentally friendly ink, comprising the following raw materials in parts by weight: 45 parts of sulfonic acid type water-based polyurethane emulsion, 0.5 parts of defoaming agent, 25 parts of pigment, 30 parts of filler, 3 parts of film-forming aid, 0.5 parts of wear-resistant aid, 15 parts of ethanol, 15 parts of deionized water and 0.2 parts of ammonia water; the defoaming agent is a polyether siloxane copolymer emulsion; the pigment is titanium dioxide; the filler is fumed silica; the film-forming aid is a mixture of ethylene glycol methyl ether and diethylene glycol butyl ether in a mass ratio of 1:1; the wear-resistant aid is emulsified Brazilian wax; the volume fraction of ethanol is 95%; The sulfonic acid type waterborne polyurethane emulsion is prepared by the following steps: Step S1: Place polytetramethylene ether glycol in a three-necked flask equipped with a reflux condenser, a thermometer and a stirrer, vacuum dry at 110°C for 1 hour, then start stirring, add isophorone diisocyanate and dibutyltin dilaurate to the flask, raise the temperature to 90°C, stir and react at constant temperature for 3 hours, cool to 80°C, add the chain extender obtained in Example 1 and acetone, stir and react at 80°C for 3 hours to obtain a prepolymer, cool to 70°C, add Add hydroxyethyl acrylate and 2,6-di-tert-butyl-p-methylphenol, and react with stirring at 70°C for 1 hour to obtain a reaction system, wherein the amount ratio of isophorone diisocyanate, polytetramethylene ether glycol, chain extender, hydroxyethyl acrylate, dibutyltin dilaurate, acetone and 2,6-di-tert-butyl-p-methylphenol is 1.0 mol: 0.17 mol: 0.71 mol: 0.008 mol: 0.001 mol: 500 mL: 0.008 mol; Step S2: adding azobisisobutyronitrile and the fluorescent agent obtained in Example 4 to DMF, stirring for 10 minutes to obtain a mixed solution, slowly dropping the mixed solution into the above reaction system, after the dropwise addition is completed, adding acetone with stirring, heating to 80°C, stirring and reacting at a constant temperature for 6 hours, cooling to 40°C to obtain a mixed system, transferring the mixed system to a reactor, adding deionized water for emulsification at a high-speed shear of 900 r / min, and obtaining a sulfonic acid type waterborne polyurethane emulsion, wherein the amount ratio of azobisisobutyronitrile, fluorescent agent, DMF and acetone is 0.003 mol: 0.008 mol: 50 mL: 600 mL.

[0028] A cooking-resistant environmentally friendly ink is prepared by the following steps: Add sulfonic acid type water-based polyurethane emulsion and defoamer into a stirring kettle, stir at 500 r / min for 10 minutes, then increase the speed to 2000 r / min, high-speed shear and disperse grinding for 30 minutes, add pigment, filler, film-forming aid, wear-resistant aid, ethanol and deionized water into the stirring kettle, high-speed shear and disperse grinding at 3000 r / min for 60 minutes, adjust the pH to 8.0 with ammonia water to obtain cooking-resistant environmentally friendly ink. Example

[0029] A cooking-resistant environmentally friendly ink, comprising the following raw materials in parts by weight: 50 parts of sulfonic acid type water-based polyurethane emulsion, 0.8 parts of defoaming agent, 30 parts of pigment, 35 parts of filler, 4 parts of film-forming aid, 0.8 parts of wear-resistant aid, 18 parts of ethanol, 18 parts of deionized water and 0.3 parts of ammonia water; the defoaming agent is a polyether siloxane copolymer emulsion; the pigment is titanium dioxide; the filler is fumed silica; the film-forming aid is a mixture of ethylene glycol methyl ether and diethylene glycol butyl ether in a mass ratio of 1:1; the wear-resistant aid is emulsified Brazilian wax; the volume fraction of ethanol is 95%; The sulfonic acid type waterborne polyurethane emulsion is prepared by the following steps: Step S1: Place polytetramethylene ether glycol in a three-necked flask equipped with a reflux condenser, a thermometer and a stirrer, vacuum dry at 110°C for 1 hour, then start stirring, add isophorone diisocyanate and dibutyltin dilaurate to the flask, raise the temperature to 90°C, stir and react at constant temperature for 3.1 hours, cool to 80°C, add the chain extender obtained in Example 2 and acetone, stir and react at 80°C for 3 hours to obtain a prepolymer, cool to 70°C, add Hydroxyethyl acrylate and 2,6-di-tert-butyl-p-methylphenol were stirred and reacted at 70°C for 1.2 hours to obtain a reaction system, wherein the amount ratio of isophorone diisocyanate, polytetramethylene ether glycol, chain extender, hydroxyethyl acrylate, dibutyltin dilaurate, acetone and 2,6-di-tert-butyl-p-methylphenol was 1.0 mol: 0.17 mol: 0.71 mol: 0.008 mol: 0.0015 mol: 525 mL: 0.009 mol; Step S2: Add azobisisobutyronitrile and the fluorescent agent obtained in Example 5 to DMF, stir for 12 minutes to obtain a mixed solution, slowly drop the mixed solution into the above reaction system, after the dropwise addition is completed, add acetone under stirring, heat to 80°C, react at a constant temperature with stirring for 6.2 hours, cool to 40°C to obtain a mixed system, transfer the mixed system to a reactor, add deionized water under 900r / min high-speed shearing to emulsify, and obtain a sulfonic acid type water-based polyurethane emulsion, wherein the amount ratio of azobisisobutyronitrile, fluorescent agent, DMF and acetone is 0.0035mol:0.008mol:55mL:650mL.

[0030] A cooking-resistant environmentally friendly ink is prepared by the following steps: Add sulfonic acid type water-based polyurethane emulsion and defoamer into a stirring kettle, stir at 550 r / min for 12 minutes, then increase the speed to 2000 r / min, high-speed shear and disperse grinding for 30 minutes, add pigment, filler, film-forming aid, wear-resistant aid, ethanol and deionized water into the stirring kettle, high-speed shear and disperse grinding at 3000 r / min for 60 minutes, adjust the pH to 8.2 with ammonia water to obtain cooking-resistant environmentally friendly ink. Example

[0031] A cooking-resistant environmentally friendly ink, comprising the following raw materials in parts by weight: 45-55 parts of sulfonic acid type water-based polyurethane emulsion, 1 part of defoamer, 35 parts of pigment, 40 parts of filler, 5 parts of film-forming aid, 1 part of wear-resistant aid, 20 parts of ethanol, 20 parts of deionized water and 0.5 parts of ammonia water; the defoamer is a polyether siloxane copolymer emulsion; the pigment is titanium dioxide; the filler is fumed silica; the film-forming aid is a mixture of ethylene glycol methyl ether and diethylene glycol butyl ether in a mass ratio of 1:1; the wear-resistant aid is emulsified Brazilian wax; the volume fraction of ethanol is 95%; The sulfonic acid type waterborne polyurethane emulsion is prepared by the following steps: Step S1: Place polytetramethylene ether glycol in a three-necked flask equipped with a reflux condenser, a thermometer and a stirrer, vacuum dry at 110°C for 1 hour, then start stirring, add isophorone diisocyanate and dibutyltin dilaurate to the flask, raise the temperature to 90°C, stir and react at constant temperature for 3.2 hours, cool to 80°C, add the chain extender obtained in Example 3 and acetone, stir and react at 80°C for 3 hours to obtain a prepolymer, cool to 70°C, add Add hydroxyethyl acrylate and 2,6-di-tert-butyl-p-methylphenol, and react with stirring at 70°C for 1.5h to obtain a reaction system, wherein the amount ratio of isophorone diisocyanate, polytetramethylene ether glycol, chain extender, hydroxyethyl acrylate, dibutyltin dilaurate, acetone and 2,6-di-tert-butyl-p-methylphenol is 1.0 mol: 0.17 mol: 0.71 mol: 0.008 mol: 0.002 mol: 550 mL: 0.010 mol; Step S2: Add azobisisobutyronitrile and the fluorescent agent obtained in Example 6 to DMF, stir for 15 minutes to obtain a mixed solution, slowly drop the mixed solution into the above reaction system, after the dropwise addition is completed, add acetone under stirring, heat to 80°C, react at a constant temperature with stirring for 6.5 hours, cool to 40°C to obtain a mixed system, transfer the mixed system to a reactor, add deionized water under 900r / min high-speed shearing to emulsify, and obtain a sulfonic acid type water-based polyurethane emulsion, wherein the amount ratio of azobisisobutyronitrile, fluorescent agent, DMF and acetone is 0.004mol:0.008mol:60mL:700mL.

[0032] A cooking-resistant environmentally friendly ink is prepared by the following steps: Add sulfonic acid type water-based polyurethane emulsion and defoamer into a stirring kettle, stir at 600 r / min for 15 minutes, then increase the speed to 2000 r / min, high-speed shear and disperse grinding for 30 minutes, add pigment, filler, film-forming aid, wear-resistant aid, ethanol and deionized water into the stirring kettle, high-speed shear and disperse grinding at 3000 r / min for 60 minutes, adjust the pH to 8.5 with ammonia water to obtain cooking-resistant environmentally friendly ink.

[0033] Comparative Example 1 This comparative example is a commercially available retort-resistant environmentally friendly ink.

[0034] Comparative Example 2 Compared with Example 9, the chain extender was replaced with 2,2-dihydroxymethylpropionic acid, and the other steps were the same as those in Example 9 to obtain a boiling-resistant and environmentally friendly ink.

[0035] Comparative Example 3 Compared with Example 9, the fluorescent agent is replaced with 3-aminocarbazole, and the other steps are exactly the same as Example 9 to obtain a boiling-resistant and environmentally friendly ink.

[0036] The following is a further effect test on the boiling-resistant environmentally friendly ink prepared by the present invention, and the test results are as follows.

[0037] In order to test the cooking-resistant environmentally friendly ink prepared by the present invention, performance tests were carried out according to GB / T13217.4-2023, GB / T13217.7-2023, QB / T5344-201X and related standards, and the results are shown in Table 1.

[0038] Table 1:

[0039] According to the data in Table 1, compared with Example 1, it can be seen that the retort-resistant environmentally friendly ink prepared in Example 7, Example 8 and Example 9 has a viscosity suitable for printing, excellent adhesion, high retort resistance, good heat resistance and high solid content compared with the commercially available retort-resistant environmentally friendly ink; compared with Example 2, it can be seen that compared with the use of a synthetic chain extender, the solid content of the ink obtained by using 2,2-dihydroxymethylpropionic acid to participate in the chain extension reaction of polyurethane is greatly reduced, and the sulfonate type chain extender has a greater advantage in increasing the solid content of the ink; compared with Example 3, it can be seen that compared with the use of a synthetic fluorescent agent, carbazole is used to act as a fluorescent agent, the lack of a double bond cannot be grafted with polyurethane and the lack of an organic silane structure leads to a decrease in the retort resistance and heat resistance of the obtained ink.

[0040] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described 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 protection scope of the present invention.

Claims

1. A boiling-resistant environmentally friendly ink, characterized by: The invention comprises the following raw materials in parts by weight: 45-55 parts of sulfonic acid type waterborne polyurethane emulsion, 0.5-1 parts of defoaming agent, 25-35 parts of pigment, 30-40 parts of filler, 3-5 parts of film-forming agent, 0.5-1 parts of wear-resistant agent, 15-20 parts of ethanol, 15-20 parts of deionized water and 0.2-0.5 parts of ammonia water; the defoaming agent is polyether siloxane copolymer emulsion; the pigment is carbon black; the filler is fumed nano-silica; the film-forming agent is a mixture of ethylene glycol methyl ether and diethylene glycol butyl ether in a mass ratio of 1:1; the wear-resistant agent is Brazilian emulsified wax; the volume fraction of ethanol is 95%; The sulfonic acid type waterborne polyurethane emulsion is prepared by the following steps: Step S1: placing polytetramethylene ether glycol in a three-necked flask equipped with a reflux condenser, a thermometer and a stirrer, vacuum drying at 110° C. for 1 hour, then starting stirring, adding isophorone diisocyanate and dibutyltin dilaurate to the flask, heating to 90° C., stirring and reacting at a constant temperature for 3-3.2 hours, cooling to 80° C., adding a chain extender and acetone, stirring and reacting at 80° C. for 3 hours to obtain a prepolymer, cooling to 70° C., adding hydroxyethyl acrylate and 2,6-di-tert-butyl-p-methylphenol to the prepolymer, stirring and reacting at 70° C. for 1-1.5 hours to obtain a reaction system; Step S2: Add azobisisobutyronitrile and a fluorescent agent to DMF, stir for 10-15 minutes to obtain a mixed solution, slowly drop the mixed solution into the above reaction system, add acetone under stirring after the dropwise addition is completed, heat to 80°C, stir and react at a constant temperature for 6-6.5 hours, cool to 40°C to obtain a mixed system, transfer the mixed system to a reactor, add deionized water under 900r / min high-speed shearing to emulsify, and obtain a sulfonic acid type waterborne polyurethane emulsion.

2. The boiling-resistant environmentally friendly ink according to claim 1, characterized in that: The chain extender is prepared by the following steps: Step A1: Add N,N-dihydroxyethylglycine to DMF, add dichlorothionyl under stirring, reflux and stir at 50°C for 4-5h, filter, extract and dry to obtain intermediate 1; Step A2: Add 2-hydroxy-2-methyl-3-butyronitrile, potassium carbonate and dimethyl sulfoxide into a flask to obtain a mixed solution a, then add the intermediate 1 into dimethyl sulfoxide to obtain a mixed solution b, slowly dropwise add the mixed solution b into the mixed solution a in a 0°C ice-water bath, after the dropwise addition is completed, heat to 40°C, react at constant temperature for 8-10 hours, and distill under reduced pressure to obtain the intermediate 2; Step A3: Add intermediate 2 and ethanol aqueous solution into a flask, start stirring, then add sodium nitrite, slowly raise the temperature to 90-95°C, when the liquid in the flask boils, start adding a saturated aqueous solution of sodium bisulfite dropwise, after the addition is complete, continue stirring and reacting for 3-3.5 hours to obtain a mixed solution c, cool the mixed solution c to room temperature, vacuum pump for 15-20 minutes, then pour the mixed solution into ethanol aqueous solution to precipitate, extract with ethanol, and vacuum pump for 30-40 minutes to obtain a chain extender.

3. The boiling-resistant environmentally friendly ink according to claim 1, characterized in that: The fluorescent agent is prepared by the following steps: Step B1: Add 3-aminocarbazole to a flask, add dichloromethane, stir for 5-10 minutes, place the flask in a 0°C ice-water bath, quickly add isocyanoethyl methacrylate, stir and react for 20-25 minutes, heat to room temperature, continue stirring and react for 16 hours, filter, recrystallize the filter cake with anhydrous ethanol, wash the crystals with anhydrous ether, and then dry the crystals in a vacuum drying oven at room temperature for 24 hours to obtain intermediate a; Step B2: Add intermediate a, (3-chloropropyl)triethoxysilane, tetra-n-butylammonium bromide, toluene and sodium hydroxide solution to a flask, stir and react at 45°C for 3-3.5 hours, then cool to room temperature, and stir and react at room temperature for 12 hours. The reaction solution is divided into an upper layer and a lower layer. The upper layer is washed with deionized water, and then with saturated brine. It is then dried with anhydrous sodium sulfate, concentrated, and then recrystallized by adding petroleum ether. Dichloromethane is added to the obtained crystals, and then ethanol is added to precipitate crystals. The crystals are then recrystallized with anhydrous ethanol to obtain a fluorescent agent.

4. The boiling-resistant environmentally friendly ink according to claim 1, characterized in that: In step S1, the usage ratio of isophorone diisocyanate, polytetramethylene ether glycol, chain extender, hydroxyethyl acrylate, dibutyltin dilaurate, acetone and 2,6-di-tert-butyl-p-methylphenol is 1.0 mol: 0.17 mol: 0.71 mol: 0.008 mol: 0.001-0.002 mol: 500-550 mL: 0.008-0.010 mol.

5. The boiling-resistant environmentally friendly ink according to claim 1, characterized in that: In step S2, the usage ratio of azobisisobutyronitrile, fluorescent agent, DMF and acetone is 0.003-0.004 mol: 0.008 mol: 50-60 mL: 600-700 mL.

6. The environmentally friendly boiling-resistant ink according to claim 2, characterized in that: In step A1, the usage ratio of N,N-dihydroxyethylglycine, DMF and dithionyl chloride is 0.1 mol:150 mL:0.2-0.3 mol.

7. The environmentally friendly boiling-resistant ink according to claim 2, characterized in that: In step A2, the usage ratio of intermediate 1, 2-hydroxy-2-methyl-3-butyronitrile, potassium carbonate and dimethyl sulfoxide is 0.1 mol: 0.1 mol: 0.01-0.015 mol: 100 mL.

8. The environmentally friendly boiling-resistant ink according to claim 2, characterized in that: In step A3, the usage ratio of intermediate 2, ethanol aqueous solution, sodium nitrite and saturated aqueous solution of sodium bisulfite is 0.1 mol:180-200 mL:0.016 mol:20-25 mL, the volume ratio of ethanol to water in the ethanol aqueous solution is 8:2, and the volume fraction of ethanol is 95%.

9. The boiling-resistant and environmentally friendly ink according to claim 3, characterized in that: In step B1, the amount ratio of 3-aminocarbazole, dichloromethane and isocyanoethyl methacrylate is 0.1 mol: 150 mL: 0.10-0.12 mol; in step B2, the amount ratio of intermediate a, (3-chloropropyl)triethoxysilane, tetra-n-butylammonium bromide, toluene, sodium hydroxide solution, petroleum ether and dichloromethane is 0.03 mol: 0.28-0.30 mol: 0.003 mol: 50 mL: 50 mL: 100 mL: 10-12 mL.

10. The method for preparing a boiling-resistant environmentally friendly ink according to claim 1, characterized in that: Prepared by the following steps: Add sulfonic acid type water-based polyurethane emulsion and defoamer into a stirring kettle, stir at a speed of 500-600r / min for 10-15min, then increase the speed to 2000r / min, high-speed shear and disperse grinding for 30min, add pigment, filler, film-forming aid, wear-resistant aid, ethanol and deionized water into the stirring kettle, high-speed shear and disperse grinding at a speed of 3000r / min for 60min, adjust the pH to 8.0-8.5 with ammonia water to obtain cooking-resistant environmentally friendly ink.

Images