Environment-friendly water-based acrylic gravure ink and preparation process thereof

Abstract

This invention relates to the field of water-based ink technology, specifically to an environmentally friendly water-based acrylic gravure ink and its preparation process. The environmentally friendly water-based acrylic gravure ink comprises, by weight percentage: 30-70% pre-mixed resin solution, 0-30% water-based color paste, 0.1-1% water-based defoamer, 0.2-5% water-based wetting agent, 1-15% deionized water, 1-30% alcohol solvent, and 0-1% water-based chlorinated polypropylene emulsion. The pre-mixed resin solution comprises: 10-70% alkali-soluble colloidal acrylic resin, 0.5-5% pH adjuster, 20-50% alcohol solvent, and 1-20% deionized water. The alkali-soluble colloidal acrylic resin of this invention is prepared using a composite reactive emulsifier, and its monomers include glycidyl methacrylate. The water-based ink prepared by this invention exhibits excellent adhesion to transfer paper and other carriers, as well as superior die-cutting performance.

Description

Technical Field

[0001] This invention relates to the field of water-based ink technology, specifically to an environmentally friendly water-based acrylic gravure ink and its preparation process. Background Technology

[0002] Transfer paper, due to its high gloss, strong metallic texture, good flexibility, and aesthetic appeal, is widely used in the exquisite packaging of products such as wine, cigarettes, food, pharmaceuticals, cosmetics, daily chemicals, department stores, gifts, and handicrafts, making it a high-end packaging material with excellent decorative and anti-counterfeiting properties. However, the smooth surface of transfer paper results in poor ink absorption, making it difficult for the ink layer to penetrate into the paper. The ink only dries and solidifies on the surface, leading to poor ink adhesion. Furthermore, during printing, issues such as creases, folds, "bursting lines," and uneven ink application can easily occur, severely affecting print quality and reducing yield. Traditional solutions to these problems include adjusting the doctor blade, grinding the gravure plate surface, replacing the transfer paper, or adjusting the ink's penetration and adhesion to the transfer paper.

[0003] As a binder for water-based inks, the performance of water-based acrylic resins greatly affects the quality of the ink. The binder, as the continuous phase of the ink, is the flowing part of the ink and a key factor affecting its printing performance; the quality of the binder directly impacts the ink's performance. The function of the binder is to ensure that pigments are finely and evenly dispersed on the dispersing equipment; to ensure firm adhesion to the substrate; and to provide the ink with the necessary gloss, drying properties, and printability.

[0004] Currently, acrylic resin emulsions are widely used as binders in water-based ink production due to their advantages such as high stability, good gloss, good weather resistance, and good rheological properties. However, inks formulated with acrylic resin emulsions often suffer from drawbacks such as low stability, poor anti-tack properties, poor water resistance, and poor adhesion. Therefore, it is necessary to modify acrylic resin emulsions to meet the application requirements of water-based inks for transfer paper. Current modification methods for acrylic ester emulsions mainly include monomer modification, resin compounding modification, and inorganic particle modification.

[0005] CN110713750A discloses an environmentally friendly water-based acrylic gravure ink for printing on transfer paper. This ink includes film-forming resin emulsions such as water-based polybutadiene resin emulsion, epoxy-modified acrylic resin emulsion, and polyurethane-acrylate composite emulsion. It addresses the problem of poor ink film adhesion by compounding multiple emulsions. However, the polybutadiene emulsion has poor compatibility with acrylic resin emulsion and polyurethane-acrylate composite emulsion, making the composite emulsion prone to demulsification, resulting in a short shelf life and hindering industrial application.

[0006] CN108276515A discloses a high-gloss acrylic emulsion composition for cigarette packaging, which improves the crosslinking density of the coating film by introducing crosslinking active monomers into the acrylic resin, thereby improving the water resistance of the coating film. However, the increase in the crosslinking density of the coating film often leads to a decrease in adhesion, making it difficult for the obtained acrylic emulsion to meet the application requirements of gravure inks for transfer paper.

[0007] This invention provides a water-based acrylic ink with a reasonable formulation, exhibiting excellent properties such as good stability, moderate viscosity, low water absorption, and high adhesion. It can greatly improve the adhesion and water resistance of the formulated water-based ink and can be used in high-speed printing processes for beer packaging, cigarette pack transfer paper, and other applications. Summary of the Invention

[0008] The main objective of this invention is to provide an environmentally friendly water-based acrylic gravure ink and its preparation process. The ink formulation is rationally configured, the preparation process is simple, and the resulting water-based ink has advantages such as good stability, moderate viscosity, low water absorption, high adhesion, high-speed printing capability, and environmental friendliness. It can meet the quality requirements of mass production and can be used in high-speed printing processes for beer packaging, cigarette pack transfer paper, and other applications.

[0009] The environmentally friendly water-based acrylic gravure ink comprises the following components by weight percentage: 30-70% pre-mixed resin solution, 0-30% water-based color paste, 0.1-1% water-based defoamer, 0.2-5% water-based wetting agent, 1-15% deionized water, 1-30% alcohol solvent, and 0-1% water-based chlorinated polypropylene emulsion.

[0010] The solid content of the environmentally friendly water-based acrylic gravure ink can be adjusted by those skilled in the art according to actual application requirements. Adjustment methods are conventional in the field, such as adjusting the amount of solvent, the amount of resin solution, or the solid content. Preferably, the solid content of the environmentally friendly water-based acrylic gravure ink is 25-50%.

[0011] The pre-mixed resin solution includes alkali-soluble colloidal acrylic resin, pH adjuster, alcohol solvent, and deionized water.

[0012] Specifically, by weight percentage, the pre-prepared resin solution comprises 10-70% alkali-soluble colloidal acrylic resin, 0.5-5% pH adjuster, 20-50% alcohol solvent, and 1-20% deionized water.

[0013] Preferably, the pre-prepared resin solution comprises, by weight percentage: 25-60% alkali-soluble colloidal acrylic resin, 2-4% pH adjuster, 30-50% alcohol solvent, and 5-10% deionized water.

[0014] The pH adjuster is any one or a combination of two organic amines and inorganic ammonia. The organic amine includes at least one of dimethylethanolamine, triethylamine, and triethanolamine; the inorganic amine is ammonia water.

[0015] The aqueous wetting agent is any one or a combination of polyoxyethylene ethers, organosilicon aqueous leveling wetting agents, and anionic perfluorocarbon surfactants.

[0016] The water-based defoamer is any one or a combination of water-based mineral oil defoamers or water-based organosilicon defoamers.

[0017] The alcohol solvent is any one or a combination of ethanol, isopropanol, or n-propanol.

[0018] The water-based color paste can be any one or two of water-based color pastes or water-based dyes.

[0019] The aqueous chlorinated polypropylene emulsion can be selected from Wuhan Hyper-CPP25, and the chlorine content of the aqueous chlorinated polypropylene emulsion is 5-8%, and the solid content is 25-30%. Preferably, the mass percentage of the aqueous chlorinated polypropylene emulsion in the environmentally friendly aqueous acrylic gravure ink is 0.1-0.3%.

[0020] The preparation method of the alkali-soluble colloidal acrylic resin includes the following steps: S1. Preparation of pre-emulsion: Weigh each raw material component, add 90-110 parts of deionized water, 2-5 parts of composite emulsifier, 3-7 parts of acrylic resin and 0.1-1 parts of buffer to a stirring container and stir until completely dissolved. The stirring temperature is controlled at 20-30℃ to obtain a mixed solution. Then, slowly add 80-90 parts of mixed monomers dropwise to the mixed solution and stir at a speed of 500-1000 rpm for 20-40 minutes. The stirring temperature is maintained at 20-30℃. Finally, cool at room temperature to obtain the pre-emulsion.

[0021] S2. Preparation of alkali-soluble colloidal acrylic resin: Take 1 / 12 to 1 / 8 of the pre-emulsion into a reactor, heat the reactor to 70-90°C, and then slowly add 20-35% of the total weight of the initiator into the reactor, stirring continuously until blue light appears; continue to add the remaining pre-emulsion, initiator, and 3-7 parts of glycidyl methacrylate, and polymerize at a constant temperature for 0.5-1.5 hours to obtain an acrylic emulsion; finally, cool the acrylic emulsion to room temperature, adjust the pH value to 7-9 with sodium hydroxide solution, filter and discharge to obtain alkali-soluble colloidal acrylic resin.

[0022] The acrylic resin includes any one or a combination of two of pure acrylic resin or styrene-acrylic resin. Preferably, the acrylic resin can be selected from one or more of Soluryl-120, Soluryl-70, Soluryl-90, Joncryl-690, Joncryl-67, Joncryl-611, and Joncryl-678.

[0023] The mixed monomers include a combination of hard and soft monomers; the composite emulsifier includes one or more of nonionic reactive emulsifiers and anionic reactive emulsifiers. The hard monomers include methyl methacrylate and styrene, and the soft monomers include butyl acrylate. The buffer includes sodium bicarbonate, and the initiator includes ammonium persulfate.

[0024] Preferably, the composite emulsifier is a combination of a nonionic reactive emulsifier and anionic reactive emulsifier.

[0025] Preferably, the mass ratio of soft monomers to hard monomers in the mixed monomers is 1:(0.9~1.1), and more preferably 1:1.

[0026] Preferably, in the hard monomer, the mass ratio of methyl methacrylate to styrene is 1:(0.5~2).

[0027] Preferably, the proportion of glycidyl methacrylate in the alkali-soluble colloidal acrylic resin is 2.5% to 8.5% based on solids.

[0028] Preferably, the hard monomers in the alkali-soluble colloidal acrylic resin account for 30% to 50% of the total solids content.

[0029] Preferably, the proportion of soft monomers in the alkali-soluble colloidal acrylic resin is 30% to 50% based on solids.

[0030] Preferably, based on solids, the alkali-soluble colloidal acrylic resin contains 35-48% soft monomers and 35-48% hard monomers.

[0031] The alkali-soluble colloidal acrylic resin has a solid content of 30-60%. The average particle size of the alkali-soluble colloidal acrylic resin is 20-80 nm.

[0032] Furthermore, the preparation method of the pre-mixed resin solution includes the following steps: weigh each raw material component, then add deionized water, alcohol solvent, and pH adjuster to the mixing tank, and disperse at medium speed for 3-5 minutes using a disc-type stirring paddle; then add alkali-soluble colloidal acrylic resin while stirring, and disperse at 500-1500 rpm for 8-30 minutes to obtain the pre-mixed resin solution.

[0033] The preparation process of the environmentally friendly water-based acrylic gravure ink includes the following steps: SS1 Preparation of pre-mixed water-based color paste: First, add part of alcohol solvent and part of water-based wetting agent to the mixing tank, and disperse at medium speed for 3-5 minutes using a disc agitator; then add color powder and disperse at 500-1500 rpm for 5-10 minutes to obtain pre-mixed water-based color paste.

[0034] SS2 mixing and dispersion preparation of ink: The pre-mixed resin solution is put into an open tank, and then the pre-mixed water-based color paste, water-based defoamer, remaining water-based wetting agent, remaining alcohol solvent, water-based chlorinated polypropylene emulsion and deionized water are added in sequence while stirring. Then, the mixture is dispersed at 500~1500rpm for 10~15min using a disc agitator to obtain the finished ink.

[0035] The beneficial effects of this invention are as follows: First, the alkali-soluble colloidal acrylic resin component in the water-based acrylic gravure ink for transfer paper prepared by this invention uses a polymerizable emulsifier as the emulsifier component. By participating in the polymerization reaction, the emulsifier is attached to the polymer, and the emulsifier molecules are less prone to migration, thereby improving the water resistance of the emulsion coating. On the other hand, the film-forming emulsion of this invention is obtained through soap-free emulsion polymerization, resulting in an emulsion with small particle size and good permeability to the transfer paper substrate, which helps to improve the adhesion of the ink to the substrate.

[0036] Secondly, the alkali-soluble colloidal acrylic resin of the present invention uses glycidyl methacrylate as a functional monomer, and introduces epoxy groups into the side groups of the molecular chain of the emulsion to improve the adhesion and water resistance of the coating film. On the other hand, adding an appropriate amount of waterborne chlorinated polypropylene emulsion to the waterborne ink further enhances the application performance such as the adhesion of the ink to the water-based substrate.

[0037] Furthermore, by selecting the types and ratios of hard and soft monomers in the film-forming emulsion, this invention effectively balances the hardness, toughness, and toughness of the film-forming emulsion as well as its film-forming properties.

[0038] Specific implementation methods The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described and illustrated below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments provided by this invention without inventive effort are within the scope of protection of this invention.

[0040] Example 1 Step 1: Preparation of alkali-soluble colloidal acrylic resin. The preparation method of the alkali-soluble colloidal acrylic resin is as follows: (1) Weigh the raw materials. By weight, weigh 3 parts of composite emulsifier (nonionic polymerizable emulsifier ER-30 and anionic polymerizable emulsifier SE-10N, with a mass ratio of 1:1), 5 parts of glycidyl methacrylate, 86 parts of mixed monomers, 1 part of acrylic resin, 0.5 parts of buffer sodium bicarbonate, 0.6 parts of initiator ammonium persulfate, and 100 parts of deionized water. The mixed monomers are soft monomers and hard monomers in a mass ratio of 1:1; the soft monomer is butyl acrylate; the hard monomers are styrene and methyl methacrylate in a mass ratio of 1:1. The acrylic resin is Soluryl-120.

[0041] (2) Preparation of pre-emulsion: First, according to the ratio, deionized water, composite emulsifier, acrylic acid and buffer are added to a stirring container and stirred evenly until completely dissolved. The stirring temperature is controlled at about 20°C to obtain a mixed solution. Then, the mixed monomers are slowly added dropwise to the mixed solution and stirred at a speed of 800 r / min for about 30 min. The stirring time is controlled at about 25°C. The pre-emulsion is obtained by cooling at room temperature. (3) Preparation of alkali-soluble colloidal acrylic resin: First, take 1 / 10 of the weight of the pre-emulsion into the reactor, heat the reactor to 80°C, and then slowly add about 1 / 3 of the weight of the initiator into the reactor, stirring continuously until blue light appears; continue to add the remaining pre-emulsion, the remaining initiator and glycidyl methacrylate, and polymerize at a constant temperature for 1 hour to obtain an acrylic emulsion; finally, cool the acrylic emulsion to room temperature, adjust the pH value to about 7.5 with sodium hydroxide solution, filter and discharge to obtain alkali-soluble colloidal acrylic resin A.

[0042] Step 2: Preparation of pre-mixed resin solution: Add 5 parts water, 26 parts ethanol, and 4 parts pH adjuster dimethylethanolamine to a mixing tank and disperse at medium speed for 3 minutes using a disc agitator. Then, while stirring, add 65 parts alkali-soluble colloidal acrylic resin and disperse at 1000 rpm for 20 minutes to obtain a pre-prepared resin solution.

[0043] Step 3: Preparing the ink: S1, Preparation of pre-mixed water-based color paste: Add 39.8 parts of ethanol and 0.2 parts of water-based leveling and wetting agent Tego270 to the mixing tank, and disperse at medium speed for 5 min using a disc stirrer; then add 60 parts of transparent yellow pigment, and disperse at 1000 rpm for 5 min to obtain the pre-mixed water-based color paste.

[0044] S2, Mixing, Dispersion and Conditioning: Add 55 parts of pre-mixed resin solution to the mixing tank, and then add 20 parts of water-based color paste, 0.1 parts of water-based defoamer Tego810, 1 part of deionized water, 23.4 parts of ethanol, and 0.5 parts of water-based leveling and wetting agent Tego270 in sequence while stirring. Disperse the mixture using a disc agitator at 500 rpm for 15 minutes. Finally, adjust the pH of the ink to approximately 8.0 to obtain the finished product.

[0045] Example 2: Step one is basically the same as step one in Example 1, except that an equal amount of Joncryl-67 is used to replace Soluryl-120.

[0046] Step two is: Add 5 parts water, 40 parts isopropanol, and 4.5 parts pH adjuster dimethylethanolamine to a mixing tank and disperse at medium speed for 3 minutes using a disc agitator. Then, while stirring, add 50.5 parts alkali-soluble colloidal acrylic resin and disperse at 1000 rpm for 20 minutes to obtain a pre-mixed resin solution.

[0047] Step three is: S1, Preparation of pre-mixed water-based color paste: Add 52 parts of ethanol and 1 part of water-based leveling and wetting agent tego270 to the mixing tank, and disperse at medium speed for 5 min using a disc stirrer; then add 47 parts of pink pigment, and disperse at 1000 rpm for 5 min to obtain the pre-mixed water-based color paste.

[0048] S2, Mixing, Dispersion and Conditioning: Add 50 parts of pre-mixed resin solution to the mixing tank, and then add 30 parts of water-based color paste, 0.1 parts of water-based defoamer Tego810, 3 parts of deionized water, 15.8 parts of isopropanol and 1 part of water-based leveling and wetting agent Tego270 in sequence while stirring. Disperse using a disc agitator at 500 rpm for 15 minutes. Finally, adjust the pH of the ink to about 8.2 to obtain the finished product.

[0049] Example 3: Based on Example 1, 0.2 parts of waterborne chlorinated polypropylene emulsion Hyper-CPP25 were added in step three of the mixing, dispersing and conditioning process.

[0050] Example 4: Based on Example 1, step one adjusts the mass ratio of the hard monomer to styrene and methyl methacrylate to 3:7.

[0051] Example 5:

[0052] Based on Example 1, step one adjusts the mass ratio of the hard monomer to styrene and methyl methacrylate to 7:3.

[0053] Comparative Example 1: Based on Example 1, in step one, glycidyl methacrylate is replaced with an equal amount of methyl methacrylate, i.e., glycidyl methacrylate is not added.

[0054] Comparative Example 2: Based on Example 1, in step one, the amount of glycidyl methacrylate was adjusted to 10 parts, and the amount of methyl methacrylate was reduced by 5 parts.

[0055] Comparative Example 3: Based on Example 1, in step one, the amount of mixed monomers remains unchanged, and the ratio of hard monomers to soft monomers is adjusted to 7:3.

[0056] Comparative Example 4: Based on Example 1, in step one, the amount of mixed monomers remains unchanged, and the ratio of hard monomers to soft monomers is adjusted to 3:7.

[0057] Comparative Example 5: Based on Example 3, in step one, glycidyl methacrylate was replaced with an equal amount of methyl methacrylate, i.e., glycidyl methacrylate was not added.

[0058] Comparative Example 6: Based on Example 3, in step one, the amount of glycidyl methacrylate was adjusted to 10 parts, and the amount of methyl methacrylate was reduced by 5 parts.

[0059] Comparative Example 7 Based on Example 3, the amount of waterborne chlorinated polypropylene emulsion Hyper-CPP25 added was adjusted to 2 parts.

[0060] Comparative Example 8 Based on Example 1, step two is omitted. In the preparation process of water-based ink, the pre-mixed resin emulsion is not prepared first. Instead, the raw material components of the pre-mixed resin emulsion are directly added in the S2 stage of step three according to the raw material ratio to prepare the finished ink.

[0061] Application performance testing The application performance of water-based inks was tested according to GB / T 26395-2024. A film was coated onto transfer paper, and the test was conducted after the film dried.

[0062] Gloss: Gloss was tested using a 60° gloss meter.

[0063] Leveling: Visual inspection, scored based on the number of pinholes, shrinkage cavities, and crystal points, with 5 points being the best and 0 points being the worst.

[0064] Adhesion: Tested using the cross-cut adhesion test, requiring grade 0 or 1, with grade 5 being the worst.

[0065] Abrasion resistance: Dry and wet abrasion tests were conducted, requiring more than 50 dry abrasion cycles and more than 20 wet abrasion cycles.

[0066] Die-cutting adaptability: Tested using the V-fold test method, simulating the indentation and folding process. Grade 0: No cracks, no tape staining (Excellent). Grade 1: Minor cracks, barely visible to the naked eye, slight tape staining (Good). Grade 2 and above: Obvious cracks, exposed white material, significant tape staining (Unacceptable).

[0067] Storage stability: Place in a -20℃ refrigerator and a 50℃ oven respectively, observe and record every 7 days, and pass if there are no problems after 6 months.

[0068] The application performance test results of the inks obtained in the examples are shown in Table 1.

[0069] Table 1: Application Performance Test Results of Examples

[0070] The application performance test results of the inks obtained in the comparative example are shown in Table 2.

[0071] Table 2: Performance Test Results of Comparative Applications

[0072] As can be seen from the test results of the examples and comparative examples in Tables 1 and 2, the water-based gravure ink for transfer paper produced in this invention exhibits excellent adhesion, resistance to dry and wet rubbing, and excellent die-cutting adaptability. The use of a composite reactive emulsifier and the introduction of an appropriate amount of glycidyl methacrylate as a functional monomer during the preparation of the alkali-soluble colloidal acrylic resin improves the adhesion of the water-based ink. Furthermore, the appropriate addition of water-based chlorinated polypropylene emulsion further enhances the adhesion and resistance to dry and wet rubbing of the water-based ink.

[0073] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An environmentally friendly water-based intaglio acrylic ink, characterized by, By mass percentage, it comprises the following components: 30-70% pre-mixed resin solution, 0-30% water-based color paste, 0.1-1% water-based defoamer, 0.2-5% water-based wetting agent, 1-15% deionized water, 1-30% alcohol solvent, and 0-1% water-based chlorinated polypropylene emulsion.

2. The eco-friendly water-based gravure printing ink according to claim 1, characterized in that, By weight percentage, the pre-prepared resin solution comprises 10-70% alkali-soluble colloidal acrylic resin, 0.5-5% pH adjuster, 20-50% alcohol solvent, and 1-20% deionized water.

3. The eco-friendly water-based gravure printing ink according to claim 2, characterized in that, The raw materials for preparing the alkali-soluble colloidal acrylic resin, by weight percentage, include a composite emulsifier, acrylic resin, mixed monomers, and glycidyl methacrylate.

4. The eco-friendly water-based gravure printing ink according to claim 3, characterized in that, The composite emulsifier is a reactive emulsifier, which includes one or more of nonionic reactive emulsifiers and anionic reactive emulsifiers.

5. The eco-friendly water-based gravure printing ink according to claim 3, characterized in that, The acrylic resin includes one or more of pure acrylic resin or styrene-acrylic resin.

6. The eco-friendly water-based gravure printing ink according to claim 3, characterized in that, The mixed monomers include soft monomers and hard monomers; the hard monomers include methyl methacrylate and styrene, and the soft monomers include butyl acrylate.

7. The eco-friendly water-based gravure printing ink according to any one of claims 1 to 6, characterized in that, The pH adjuster is one or more of organic amines and inorganic ammonia; the aqueous wetting agent is one or more of silane-based aqueous leveling wetting agents and anionic perfluorocarbon surfactants; the aqueous defoamer is one or more of aqueous mineral oil defoamers or aqueous organosilicon defoamers; and the alcohol solvent is one or more of ethanol, isopropanol, and n-propanol.

8. The eco-friendly water-based gravure printing ink according to claim 2, characterized in that, The preparation method of the alkali-soluble colloidal acrylic resin includes the following steps: S1. Preparation of pre-emulsion: Weigh each raw material component, add 90-110 parts of deionized water, 2-5 parts of composite emulsifier, 3-7 parts of acrylic resin and 0.1-1 parts of buffer to a mixing container and stir until completely dissolved. The stirring temperature is controlled at 20-30℃ to obtain a mixed solution. Then, slowly add 80-90 parts of mixed monomers dropwise to the mixed solution and stir at a speed of 500-1000 rpm for 20-40 minutes. The stirring temperature is maintained at 20-30℃. Finally, cool at room temperature to obtain the pre-emulsion. S2. Preparation of alkali-soluble colloidal acrylic resin: Take 1 / 12 to 1 / 8 of the pre-emulsion into a reactor, heat the reactor to 70-90°C, and then slowly add 20-35% of the total weight of the initiator into the reactor, stirring continuously until blue light appears; continue to add the remaining pre-emulsion, the remaining initiator, and 3-7 parts of glycidyl methacrylate, and polymerize at a constant temperature for 0.5-1.5 hours to obtain an acrylic emulsion; finally, cool the acrylic emulsion to room temperature, adjust the pH value to 7-9 with sodium hydroxide solution, filter and discharge to obtain alkali-soluble colloidal acrylic resin.

9. The eco-friendly water-based gravure printing ink according to any one of claims 1 to 7, characterized in that, The preparation method of the pre-mixed resin solution includes the following steps: Add pH adjuster, alcohol solvent, and deionized water to the mixing tank, start stirring, add alkali-soluble colloidal acrylic resin, disperse evenly, and obtain pre-mixed resin solution.

10. A process for preparing the environmentally friendly water-based gravure printing ink according to any one of claims 1-7, characterized in that, Includes the following steps: SS1 can optionally prepare pre-mixed water-based color paste: Prepare a stirable open tank, first add part of alcohol solvent and part of water-based wetting agent, and disperse at medium speed for 3-5 min using a disc-type stirring paddle; then add color powder, and disperse at 500-1500 rpm for 5-10 min to obtain pre-mixed water-based color paste; SS2 mixing and dispersion preparation of ink: The pre-mixed resin solution is put into an open tank, and then, while stirring, optional pre-mixed water-based color paste, water-based defoamer, residual water-based wetting agent, residual alcohol solvent, water-based chlorinated polypropylene emulsion, and deionized water are added in sequence. Then, the mixture is dispersed at 500~1500 rpm for 10~15 min using a disc agitator to obtain the finished ink.

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