Alcohol-free fountain solution with low water volume and low emulsified oil ink and preparation method of alcohol-free fountain solution

Abstract

The invention discloses an alcohol-free fountain solution with low water volume and low emulsified ink and a preparation method of the alcohol-free fountain solution, and belongs to the technical field of offset printing. The preparation method is characterized in that step-by-step directional assembly comprises the following steps: firstly, dissolving a buffering agent, conductive salt and a chelating agent in hot water to prepare a pre-chelating solution; stirring polyether modified siloxane, a polyether surfactant and a self-assembly auxiliary agent in a warm organic phase at a low speed to form a wet pre-assembly compound; and slowly adding the compound into a pre-chelating solution, mixing, curing, carrying out ultrasonic treatment, and filtering to obtain the product. Through a unique formula and process, functional components are pre-combined on a molecular level, and the wetting efficiency is synergistically improved, so that the printing water amount is reduced to 50-65% of the traditional amount, the emulsification rate of the ink is greatly reduced, the quality of a printed product is fundamentally improved, ink piling is prevented, and the ink has the advantages of high efficiency, environment friendliness, equipment friendliness and the like.

Description

Technical Field

[0001] This invention relates to the field of offset printing technology, specifically to an alcohol-free dampening solution for low-water, low-emulsification inks and its preparation method. Background Technology

[0002] In offset printing, dampening solution is used to wet the non-image areas of the printing plate and maintain the ink-water balance. Traditional dampening solutions often contain isopropyl alcohol (IPA) to reduce surface tension and improve wettability. However, IPA is flammable, evaporates quickly, has a strong odor, is harmful to the health of operators, and pollutes the environment. Therefore, various alcohol-free dampening solutions have appeared on the market.

[0003] However, existing alcohol-free dampening solutions, in their pursuit of being alcohol-free, often introduce new technical contradictions: First, a large water supply is usually required to achieve sufficient printing plate wetting. Excessive water will directly lead to over-emulsification of the ink, causing a series of printing defects: the viscosity of the emulsified ink decreases, resulting in dot gain, dull colors, and poor gloss; at the same time, too much water will severely delay the drying speed of the ink's oxidative film formation, affecting the efficiency of subsequent processing.

[0004] Secondly, the high emulsification caused by high water content is the root cause of printing defects. On the one hand, the structure of over-emulsified ink is damaged, and its stability deteriorates; on the other hand, the large amount of inorganic salts added to maintain conductivity reacts with the free fatty acid components in the emulsified ink to form water-insoluble soap scum. This soap scum mixes with impurities such as paper dust and coating particles shed from the paper, accumulating continuously at the trailing edge of the printing roller, forming an "ink piling" phenomenon. This forces the printing press to stop frequently for cleaning, severely restricting production efficiency and print quality.

[0005] Currently, although some technologies attempt to improve specific properties by compounding surfactants or adding chelating agents, these improvements are often isolated. The components are usually only simply mixed physically, failing to simultaneously and fundamentally solve the core contradiction between "low water wetting" and "low ink emulsification" at the level of molecular synergy and process design. This makes it difficult to truly control the ink emulsification rate and eliminate the resulting ink piling problem while reducing water content. Summary of the Invention

[0006] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention aims to overcome the problem of excessive ink emulsification caused by the high water demand of existing alcohol-free dampening solutions. It provides an alcohol-free dampening solution with low water content and low emulsification of ink, along with its preparation method. Through unique component design and process control, the functional materials form a synergistic microstructure during preparation, thereby achieving excellent printing wettability while significantly reducing printing water consumption. This results in a substantial reduction in ink emulsification rate, simultaneously resolving issues such as poor print quality, slow drying, and ink piling problems.

[0007] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides an alcohol-free dampening solution for low-water, low-emulsification inks, comprising the following components by weight percentage: Main solvent and humectant: 55%–65%. This component consists of ethylene glycol tert-butyl ether, propylene glycol, and glycerin, with a mass ratio ranging from (10-20):(20-30):(15-25). Ethylene glycol tert-butyl ether acts as the main solvent, effectively reducing the surface tension of the system and promoting the dissolution of other components; propylene glycol and glycerin act as humectants, preventing excessive evaporation of moisture and maintaining the stability of the water-ink balance. The three components work synergistically in the above ratio, providing an optimal working environment for the functional components.

[0008] Wetting agent system: 0.3%–3%. This system consists of polyether-modified siloxane and polyether surfactant (such as fatty alcohol polyoxyethylene ether), with a mass ratio of 1:(0.5–1.5). The polyether-modified siloxane provides extremely low static surface tension and rapid spreading ability, while the polyether surfactant improves dynamic wetting and dispersion stability in water. The two produce a synergistic wetting effect at the above specific ratio.

[0009] Self-assembling functional additive: 0.05%–1.5%. This additive is selected from plant polyphenol polyoxyethylene ether derivatives, preferably tea polyphenol polyoxyethylene ether, with a number average molecular weight (Mn) of 400–1500 and nano-layered silicates (such as synthetic lithium saponite). This additive is key to forming the wetting and cleaning functional composite unit. Its active groups, such as phenolic hydroxyl groups, can specifically interact with the wetting agent in subsequent preparation processes.

[0010] Conductive and buffering system: 0.7%–7%. This includes buffers (0.5%–5.0%, such as citrate and tartrate) and conductive salts (0.2%–2.0%, such as magnesium sulfate and potassium nitrate). This system is used to maintain the dampening solution in a stable, weakly acidic range of 4.5–5.0 and provides a suitable conductivity of 1200–1600 μS / cm.

[0011] Chelating stabilizers: 0.1%–3%. These are green chelating agents, such as gluconate, GLDA (tetrasodium glutamate diacetate), and EDDS (trisodium ethylenediamine disuccinate), used to strongly chelate calcium, magnesium, and other polyvalent metal ions in water, preventing them from reacting with ink components to form soap scum.

[0012] Emulsifying stabilizer and auxiliary cleaning agent: 0.1%–2%. A nonionic surfactant (such as an alkylphenol polyoxyethylene ether substitute) used to enhance the system's emulsifying and dispersing ability for ink impurities and to assist in cleaning.

[0013] Functional additives: 1.5%–8%. These include cosolvents (1.0%–3.0%, such as dipropylene glycol methyl ether), dispersants (0.2%–0.5%, such as polyacrylate), defoamers (0.1%–0.5%), and preservatives and bactericides (0.2%–1.0%), used to ensure product storage stability, workability, and biostability.

[0014] Deionized water: Balance, used as dispersion medium and diluent for the system.

[0015] Secondly, this invention provides a method for preparing the aforementioned alcohol-free dampening solution. The core of this method lies in guiding the functional components to achieve directional pre-assembly at the molecular level through a step-by-step, temperature-controlled, and speed-controlled process. This method includes the following steps: Preparation of S1 prechelated electrolyte solution: In a first container, deionized water is heated to 40–50°C, and a buffer, conductive salt, and chelation stabilizer are added and stirred until completely dissolved to obtain a prechelated electrolyte solution. The solution is then cooled to 25–35°C. This step aims to preferentially lock in metal ions.

[0016] S2 Wetting Pre-Assembled Complex Formation: In a second container, a portion of ethylene glycol tert-butyl ether (30%-50% of the total) is heated to 50-60°C. Polyether-modified siloxane, polyether surfactant, and self-assembly functional aid are added sequentially. The mixture is stirred at low speed (200-400 rpm) for 15-30 minutes to obtain a homogeneous and transparent wetting pre-assembled complex. This step is crucial for innovation; under specific temperature and organic phase conditions, the components pre-bind through intermolecular forces (such as hydrogen bonds) to form functional composite units.

[0017] S3 Controlled Integration: Under stirring conditions, the wetted pre-assembled composite obtained in step S2 is gradually added to the pre-chelated electrolyte solution in step S1 at a slow rate of 0.5–2 L / min, while maintaining a stable system temperature throughout the integration process. Slow addition aims to protect the integrity of the pre-assembled structure.

[0018] S4 Main Mixing: Add propylene glycol, glycerin, and the remaining main solvent and humectant to the system obtained in step S3 in sequence, and stir until homogeneous.

[0019] S5 Post-treatment and maturation: Add solubilizer, dispersant, defoamer and preservative and bactericide, increase the stirring speed to 400-800 rpm, and continue stirring for 30-50 minutes to homogenize and mature the system.

[0020] S6 Finishing: Cool the mixture obtained in step S5 to 20–25°C, and ultrasonically treat it at a frequency of 20–40 kHz for 5–15 minutes under the protection of an inert gas (such as nitrogen). Finally, filter to obtain the alcohol-free dampening solution. Ultrasonic treatment helps to achieve uniform dispersion and optimize performance.

[0021] Thirdly, this invention provides the application of the aforementioned alcohol-free dampening solution in offset printing. When using this dampening solution, due to its superior wetting efficiency, the water supply required by the printing press during startup and normal printing can be significantly reduced to 50%–65% of the water required by traditional alcohol-free dampening solutions. Simultaneously, thanks to its inherent dynamic cleaning and ion-blocking mechanism, it can effectively prevent ink buildup at the trailing edge of the printing roller for a long period, making it suitable for high-speed, long-run printing.

[0022] (III) Beneficial Effects The purpose of this invention is to provide an alcohol-free dampening solution for low-water, low-emulsification inks and its preparation method. It has the following beneficial effects: First, it achieves a significant reduction in ink emulsification rate: This invention, through a unique "wetting pre-assembled complex" design, optimizes the interfacial performance of the wetting unit at the molecular level, enabling rapid and uniform wetting of the printing plate with extremely low dosage. This drastically reduces the printing water supply to 50%-65% of the traditional amount, directly and effectively reducing the total amount of water intruding into the ink, thus significantly lowering the ink emulsification rate. A low-emulsification state is fundamental to ensuring the quality of all subsequent printing processes.

[0023] Secondly, it brings about a comprehensive improvement in overall printing quality: Based on the aforementioned low emulsification rate, the dampening solution of this invention brings a series of chain-like positive effects. First, the ink maintains good viscosity and tinting strength due to its low emulsification degree, resulting in more vibrant colors, higher saturation, and clearer dots in the printed product. Second, the low water content in the ink significantly accelerates the drying speed of its oxidative film, which is beneficial to improving printing efficiency. Ultimately, these factors work together to fundamentally avoid the "ink piling" problem caused by excessive ink emulsification and structural damage, achieving the dual goals of improving quality and ensuring production.

[0024] Finally, the step-by-step preparation process of this invention, especially the "pre-chelation" and "pre-assembly" steps, ensures the orderly synergy of each functional component. The formulation has a low content of conductive salts and contains sufficient amounts of highly efficient and environmentally friendly chelating agents, which can stably maintain a weakly acidic environment and block metal ions. Therefore, it has extremely low corrosiveness to the printing press's water circuits and metal rollers, extending equipment life. At the same time, the product has strong resistance to hard water, stable pH value and conductivity, and is suitable for different water qualities and operating conditions.

[0025] The formula completely eliminates isopropyl alcohol (IPA) and other harmful volatile organic compounds, using environmentally friendly raw materials to eliminate health hazards to operators and pollution to the atmospheric environment from the source, which is in line with the development direction of green printing. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] Example 1 This embodiment provides an alcohol-free dampening solution for low-water-content, low-emulsification inks, with the following composition: Deionized water: Balance (approximately 26.9%); Ethyl glycol tert-butyl ether: 15%; Propylene glycol: 22%; Glycerin: 20%; Polyether-modified siloxane: 0.4%; Polyether surfactants (fatty alcohol polyoxyethylene ethers): 0.4%; Tea polyphenol polyoxyethylene ether (Mn≈800): 0.5%; Nonionic surfactant (alternative to alkylphenol polyoxyethylene ether): 0.3%; Potassium citrate (buffer): 2.5%; Magnesium sulfate (conductive salt): 0.5%; Sodium gluconate (chelating agent): 1.0%; Dipropylene glycol methyl ether (cosolvent): 2.0%; Sodium polyacrylate (dispersant): 0.3%; Organosilicon defoamer: 0.2%; Isothiazolinone preservatives: 0.5%.

[0028] Preparation method: In the main reactor equipped with stirring and heating, a measured amount of deionized water was added, and the temperature was raised to 45°C. Potassium citrate, magnesium sulfate, and sodium gluconate were added, and the mixture was stirred at 400 rpm until completely dissolved, yielding a clear and transparent prechelated electrolyte solution. Heating was then stopped, and the solution was cooled to 30°C for later use.

[0029] In a premixing vessel, 40% of the total formulation of ethylene glycol tert-butyl ether (i.e., 6% of the total 15%) was added, and the mixture was heated to 55°C. Then, polyether-modified siloxane, fatty alcohol polyoxyethylene ether, and tea polyphenol polyoxyethylene ether were added sequentially, and the mixture was stirred continuously at a low speed of 300 rpm for 20 minutes to obtain a homogeneous, transparent wetted pre-assembled composite.

[0030] Maintain the temperature inside the main reactor at 30°C and set the stirring speed to 500 rpm. Using a metering pump, slowly and evenly pump the wetted pre-assembled complex obtained in step 2 into the main reactor at a feeding rate of 1.0 L / min. After all the material has been added, continue stirring under these conditions for 10 minutes to ensure complete integration of the complex with the pre-chelation solution.

[0031] Add propylene glycol, glycerol and the remaining ethylene glycol tert-butyl ether (9%) to the main reactor in sequence, and keep stirring to mix the components evenly.

[0032] Add dipropylene glycol methyl ether, sodium polyacrylate, silicone defoamer, and isothiazolinone preservative. Increase the stirring speed to 600 rpm and stir continuously for 40 minutes to ensure the system is fully homogenized and matured.

[0033] The resulting liquid was cooled to 22°C and protected by purging the air above the system with nitrogen. Subsequently, the liquid was treated with an ultrasonic processor at a frequency of 28 kHz for 10 minutes.

[0034] Finally, the solution was filtered using a filter bag with a pore size of 1 μm to obtain a clear and transparent finished dampening solution.

[0035] Product performance: The obtained dampening solution has a pH of 4.7 and a conductivity of 1380 μS / cm, according to the test results.

[0036] Example 2 This embodiment demonstrates the implementation of the lower limit of the main solvent ratio and wetting agent ratio range in claim 1.

[0037] Deionized water: 28.7%; Ethyl glycol tert-butyl ether: 10%; Propylene glycol: 30%; Glycerin: 25%; Polyether-modified siloxane: 0.2%; Polyether surfactant: 0.1% (mass ratio of polyether-modified siloxane to polyether surfactant is 1:0.5); Tea polyphenol polyoxyethylene ether (Mn≈400): 0.05%; Nonionic surfactant: 0.1%; Potassium citrate: 2.0%; Magnesium sulfate: 0.2%; Sodium gluconate: 0.1%; Dipropylene glycol methyl ether: 1.0%; Sodium polyacrylate: 0.2%; Organosilicon defoamer: 0.1%; Isothiazolinone preservatives: 0.2%.

[0038] Preparation method: Refer to the steps in Example 1. In step 2, the ethylene glycol tert-butyl ether used for pre-assembly is 30% (i.e., 3%) of the total amount, heated to 55°C and stirred at low speed for 15 minutes. In step 3, the feeding rate is controlled at 0.5 L / min, and the stirring speed is 300 rpm. In step 6, the ultrasonic frequency is 20 kHz, and the treatment lasts for 5 minutes.

[0039] Product performance: pH value 4.5, conductivity 1250 μS / cm.

[0040] Example 3 This embodiment demonstrates the implementation of the upper limit of the main solvent ratio and the upper limit of the content of multiple components in claim 1.

[0041] Deionized water: 15.0%; Ethyl glycol tert-butyl ether: 20%; Propylene glycol: 20%; Glycerin: 15%; Polyether-modified siloxane: 1.2%; Polyether surfactants: 1.8% (mass ratio of the two is 1:1.5); Nano-sized magnesium aluminum silicate: 1.5%; Nonionic surfactant: 2.0%; Potassium hydrogen tartrate (buffer): 5.0%; Potassium nitrate (conductive salt): 2.0%; GLDA (chelating agent): 3.0%; Dipropylene glycol methyl ether: 3.0%; Sodium polyacrylate: 0.5%; Organosilicon defoamer: 0.5%; Isothiazolinone preservatives: 1.0%.

[0042] Preparation method: Refer to the steps in Example 1. In step 2, the ethylene glycol tert-butyl ether used for pre-assembly is 50% (i.e., 10%) of the total amount, heated to 60°C and stirred at low speed for 30 minutes. In step 3, the feeding rate is controlled at 2.0 L / min, and the stirring speed is 600 rpm. In step 6, the ultrasonic frequency is 40 kHz, and the treatment lasts for 15 minutes.

[0043] Product performance: pH value 5.0, conductivity 1580 μS / cm.

[0044] Example 4 This embodiment demonstrates the implementation of claim 4 with the addition of a structuring agent.

[0045] The formula was adjusted based on Example 1: Added nano-silica: 0.25% The amount of deionized water used will be reduced accordingly to approximately 26.65%.

[0046] Preparation method: It is basically the same as in Example 1, except that in the pre-assembly process of step S2, nano-silica, tea polyphenol polyoxyethylene ether, wetting agent, etc. are added together to the premix tank for mixing.

[0047] Product performance: pH value 4.7, conductivity 1390 μS / cm. Product viscosity slightly increased, excellent static stability.

[0048] Example 5 This embodiment demonstrates the implementation of the upper limit of the pH and conductivity range in claim 3.

[0049] The formulation was adjusted based on Example 3, with modifications to the buffering and conductive systems: Buffer: Change to citric acid / tripotassium citrate system, and adjust the amount added to make the final pH value 5.0.

[0050] Conductive salt (potassium nitrate): The dosage was increased to 2.2%, resulting in a final conductivity of 1600 μS / cm. The amount of deionized water was adjusted accordingly.

[0051] Preparation method: Same as in Example 3.

[0052] Product performance: pH=5.0, conductivity=1600 μS / cm.

[0053] Comparative Example 1 This comparative example is used to demonstrate the necessity of self-assembly functional additives.

[0054] Formula: exactly the same as in Example 1, but with the removal of tea polyphenol polyoxyethylene ether (0.5%), and its proportion made up with deionized water (i.e., deionized water is 27.4%).

[0055] Preparation method: The process steps are exactly the same as those in Example 1.

[0056] Product performance: pH value 4.7, conductivity 1350 μS / cm.

[0057] Comparative Example 2 This comparative example is used to demonstrate the key aspects of the stepwise directional assembly process of the present invention.

[0058] Formula: exactly the same as in Example 3.

[0059] Preparation method: All solid components (buffers, conductive salts, chelating agents, etc.) and all liquid components (all main solvents, wetting agents, additives, etc., except for defoamers) are added to deionized water at once. The mixture is stirred directly at 800 rpm for 60 minutes at room temperature (approximately 25°C). Then, the defoamer is added, and the mixture is stirred for another 10 minutes. Finally, the mixture is filtered through a 1 μm filter bag. Pre-assembly, temperature-controlled feeding, and ultrasonic treatment are not performed.

[0060] Product performance: pH value 5.0, conductivity 1550 μS / cm.

[0061] Comparative Example 3: Product: The German Böttcher S-3007K alcohol-free dampening concentrate, which is sold in the market, was selected as a control.

[0062] Instructions for use: Dilute with deionized water at a concentration of 4% (by volume) as recommended in the product instructions, and adjust the pH of the diluted solution to the range of 4.5-5.0 for subsequent comparative testing.

[0063] Performance testing The products obtained in Examples 1-5 and Comparative Examples 1-3 were subjected to the following tests: 1. Minimum damping water volume test: On the laboratory proofing machine, adjust the damping solution concentration to the standard conductivity, and gradually reduce the water supply until the critical point where uneven water appears on the plate surface. Record the percentage of the water volume at this point relative to the normal water volume when using Comparative Example 2 to achieve good wetting.

[0064] 2. Anti-ink piling test: On a commercial four-color offset printing press, long-run printing (target 50,000 sheets) is carried out using the same batch of paper and ink. Every 5,000 sheets, the visual rating of ink piling at the end of the offset roller is checked and recorded (0: clean; 3: severe ink piling requires cleaning).

[0065] 3. Ink emulsification rate test: Mix the dampening solution with the specific offset printing ink according to the standard method, stir and centrifuge to separate the emulsification rate.

[0066] 4. Stability test: The dampening solution was sealed and stored in a 54℃ constant temperature oven for 14 days to simulate accelerated aging. The appearance was observed and the rate of change in conductivity was tested.

[0067] The test results are shown in Table 1: Table 1 Results analysis: Through a step-by-step directional assembly process, embodiments 1-5 of this invention first achieve a significant reduction in printing water content (52%-65%), and under this premise, effectively control the ink emulsification rate to a low level below 13.5%, which is significantly better than all comparative examples (19.5%-22.0%). This demonstrates the synergistic effectiveness of this invention in resolving the core contradiction between "low water content" and "low emulsification".

[0068] Key Components and Processes: Comparative Example 1 (lacking self-assembly aid) showed a significant performance deterioration, indicating that the aid is a crucial and essential component for constructing the "wetting-cleaning" functional unit and achieving low emulsification. Comparative Example 2 (simple mixing) exhibited the highest emulsification rate, fully demonstrating that the specific preparation process of this invention plays a decisive role in achieving component synergy and realizing the final performance, which cannot be replaced by simple mixing.

[0069] Overall performance: Low ink emulsification rate is the cornerstone of a series of subsequent excellent properties. As shown in Table 1, it is precisely because of the low emulsification rate that the embodiments of the present invention simultaneously exhibit excellent anti-ink piling ability and printing drying speed (low emulsification facilitates rapid ink curing). At the same time, the conductivity changes little after accelerated aging in each embodiment, indicating high system stability and equipment friendliness.

[0070] Examples 2, 3, and 5 demonstrate that, at each endpoint of the scope of the claims, the technical solution of the present invention can stably achieve low emulsification rate control under low water content, verifying the rationality of the scope of the claims.

[0071] In summary, this invention, through innovative component design and step-by-step directional assembly process, successfully and synergistically solves the technical contradiction between low water wetting and low ink emulsification rate, providing an environmentally friendly alcohol-free dampening solution with excellent overall performance suitable for high-speed long-run printing.

[0072] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An alcohol-free dampening solution for low-water, low-emulsification inks, characterized in that, By mass percentage, it includes the following components: Main solvent and humectant: 55% to 65%, wherein the main solvent and humectant include ethylene glycol tert-butyl ether, propylene glycol and glycerin in a mass ratio of (10-20):(20-30):(15-25); Wetting agent system: 0.3% to 3%, including polyether-modified siloxane and polyether surfactant, with a mass ratio of 1:(0.5-1.5); Self-assembly functional additive: 0.05% to 1.5%, wherein the self-assembly functional additive is a plant polyphenol polyoxyethylene ether derivative or a nano-layered silicate; Conductive and buffering systems: 0.7%–7%, including conductive salts and buffers; Chelating stabilizer: 0.1%–3%, a green chelating agent; Emulsifying stabilizer and auxiliary cleaning agent: 0.1%–2%, a nonionic surfactant; Functional additives: 1.5%–8%, including solubilizers, dispersants, defoamers, and preservatives and bactericides; Deionized water: Balance.

2. The alcohol-free dampening solution for low-water, low-emulsification inks according to claim 1, characterized in that, The plant polyphenol polyoxyethylene ether derivative is tea polyphenol polyoxyethylene ether, with a number average molecular weight of 400-1500.

3. The alcohol-free dampening solution for low-water, low-emulsification inks according to claim 1, characterized in that, The dampening solution has a pH of 4.5–5.0 and a conductivity of 1200–1600 μS / cm.

4. The alcohol-free dampening solution for low-water, low-emulsification inks according to claim 1, characterized in that, The dampening solution also contains 0.01% to 0.5% of a structuring agent, which is at least one of nano-silica or nano-alumina.

5. A method for preparing an alcohol-free dampening solution as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1. In the first container, deionized water is heated to 40-50°C, buffer, conductive salt and chelating stabilizer are added, and stirred to dissolve to obtain a pre-chelated electrolyte solution, and then cooled to 25-35°C. S2. In the second container, heat a portion of ethylene glycol tert-butyl ether to 50-60°C, add polyether-modified siloxane, polyether surfactant and self-assembly functional aid, and stir at a low speed of 200-400 rpm for 15-30 minutes to obtain a wetted pre-assembled composite. S3 Under stirring conditions, the wetted pre-assembled complex obtained in step S2 is slowly added to the pre-chelated electrolyte solution in step S1 at a rate of 0.5 to 2 L / min, while keeping the system temperature stable. S4. Add propylene glycol, glycerin, and the remaining main solvent and humectant sequentially to the system obtained in step S3, and stir until homogeneous. Add solubilizer, dispersant, defoamer and preservative and bactericide to S5, increase the stirring speed to 400-800 rpm, and continue stirring for 30-50 minutes; S6. The mixture obtained in step S5 is ultrasonically treated at a frequency of 20-40 kHz for 5-15 minutes, and finally filtered to obtain the alcohol-free dampening solution.

6. The method for preparing an alcohol-free dampening solution for low-water, low-emulsification inks according to claim 5, characterized in that, In step S2, the amount of the ethylene glycol tert-butyl ether used accounts for 30% to 50% of its total mass.

7. The method for preparing an alcohol-free dampening solution for low-water, low-emulsification inks according to claim 5, characterized in that, In step S3, the stirring speed is 300-600 rpm.

8. The method for preparing an alcohol-free dampening solution for low-water, low-emulsification inks according to claim 5, characterized in that, In step S6, the system is cooled to 20-25°C before ultrasonic treatment and ultrasonic treatment is performed under inert gas protection.

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