Water-based epoxy modified acrylate emulsion for ink and preparation method thereof

Abstract

The invention discloses a waterborne epoxy modified acrylate emulsion for ink and a preparation method of the waterborne epoxy modified acrylate emulsion, and relates to the technical field of ink processing. The adhesive is prepared from the following components in parts by weight: butyl acrylate, methyl methacrylate, modified epoxy resin, an emulsifier 2, dodecafluoroheptyl methacrylate, ethyl cellulose, dipropylene glycol butyl ether, N-acyl amino acid sodium, an initiator and deionized water. The coating further comprises an ultraviolet light absorber, modified nano silicon dioxide and modified hollow glass microspheres; the addition amount of the ultraviolet light absorber is 0.5%-2% of the total weight of the emulsion; the addition amount of the modified nano silicon dioxide is 1%-3% of the total weight of the emulsion; the mass ratio of the modified nano silicon dioxide to the modified hollow glass microspheres is 1: (3-4); by introducing multiple functional components and optimizing the preparation process, the water resistance, ultraviolet protection performance, drying efficiency and the like of the ink are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ink processing, in particular to a water-based epoxy-modified acrylate emulsion for ink and a preparation method thereof. Background Art

[0002] Ink is a crucial material used in printing, creating designs and text on substrates through printing or inkjet printing. Ink consists of a primary and secondary component, which is uniformly mixed and repeatedly rolled to form a viscous, colloidal fluid. It is composed of a binder (resin), pigment, filler, additive, and solvent. It is used in a variety of printing applications, including books and periodicals, packaging and decoration, architectural decoration, and electronic circuit boards. As social demand increases, the variety and production of inks are expanding and growing accordingly.

[0003] For example, Chinese patent application number CN202210949996.5, titled "A Water-Based Epoxy-Modified Acrylate Emulsion for Gravure Ink and Its Preparation Method," discloses a water-based epoxy-modified acrylate emulsion for gravure ink and its preparation method. This invention relates to the field of ink processing technology and is composed of the following ingredients: butyl acrylate, methyl methacrylate, modified epoxy resin, emulsifier, dodecafluoroheptyl methacrylate, ethyl cellulose, dipropylene glycol butyl ether, sodium N-acylamino acid, initiator, and deionized water. The invention prepares a water-based epoxy-modified acrylate emulsion for gravure ink, using water as a diluent, for use in gravure printing. The solvent used in the gravure ink is water, which is inexpensive, readily available, non-toxic, and pollution-free. The water-based epoxy-modified acrylate emulsion for gravure ink prepared by the invention exhibits good film-forming properties, is non-toxic and odorless, is environmentally friendly, and exhibits excellent bonding properties.

[0004] The above solution improves the ink's film-forming and bonding properties by introducing a modified epoxy resin and uses water as a diluent, achieving environmentally friendly printing. However, this invention still has room for improvement in terms of water resistance and UV protection. Summary of the Invention

[0005] The embodiments of the present application provide a water-based epoxy-modified acrylate emulsion for ink and a preparation method thereof, thereby solving the deficiencies of ink in the prior art in terms of water resistance and UV protection performance. By introducing multiple functional components and optimizing the preparation process, improvements in water resistance, UV protection performance, and drying efficiency of the ink are achieved.

[0006] The present application provides a water-based epoxy-modified acrylate emulsion for ink, which is prepared from the following ingredients by weight: 32 parts of butyl acrylate, 16 parts of methyl methacrylate, 7 parts of modified epoxy resin, 2.1 parts of emulsifier, 1.3 parts of dodecafluoroheptyl methacrylate, 3 parts of ethyl cellulose, 1.4 parts of dipropylene glycol butyl ether, 2 parts of sodium N-acylamino acid, 0.8 parts of initiator, and 65 parts of deionized water; The emulsion also includes a UV absorber, modified nano-silica, and modified hollow glass microspheres; Among them, the addition amount of ultraviolet absorber is 0.5%-2% of the total weight of the emulsion; The amount of modified nano-silica added is 1%-3% of the total weight of the emulsion; The mass ratio of modified nano-silica to modified hollow glass microspheres is 1:(3-4).

[0007] Furthermore, the ultraviolet absorber is Tinuvin 327.

[0008] Furthermore, the preparation method of the modified nano-silica is as follows: the surface of the nano-silica is modified by silane to form a hydrophobic layer to obtain the modified nano-silica; the particle size of the nano-silica is 10-20 nm, and the silane is octadecyltrimethoxysilane.

[0009] Furthermore, the preparation method of the modified hollow glass microspheres is as follows: mixing the hollow glass microspheres with a silane coupling agent, adding anhydrous ethanol for reaction, centrifuging and washing, and then drying to obtain hydrophobically modified hollow glass microspheres; the particle size of the hollow glass microspheres is 20-40 μm.

[0010] Furthermore, the hollow glass microspheres also include large particle sizes of 1-5 μm and small particle sizes of 0.1-1 μm, and the mass ratio of the small particle size to the large particle size is 2:3.

[0011] Furthermore, the added amount of the ultraviolet absorber is 0.5%-2% of the total weight of the emulsion, preferably 2%; the added amount of the modified nano-silica is 1%-3% of the total weight of the emulsion, preferably 3%; the mass ratio of the modified nano-silica to the modified hollow glass microspheres is 1:(3-4), preferably 1:4.

[0012] Furthermore, the ink also includes one or more layers of emulsion.

[0013] Furthermore, the ink comprises two layers of emulsion, namely a first coating layer and a second coating layer, and the particle sizes and proportions of the hollow glass microspheres in the first coating layer and the second coating layer are different.

[0014] Furthermore, the mass ratio of the modified nano-silica to the modified hollow glass microspheres in the first coating layer is 1:(3-4), the hollow glass microspheres include large particles with a diameter of 1-5 μm and small particles with a diameter of 0.1-1 μm, and the mass ratio of the small particles to the large particles is 2:3; The mass ratio of modified nano-silica to modified hollow glass microspheres in the second coating layer is 1:1.5; the hollow glass microspheres include small particles with a diameter of 0.1-1 μm and ultra-large particles with a diameter of 10-15 μm, and the mass ratio of small particles to large particles is 3:7.

[0015] A method for preparing a water-based epoxy-modified acrylate emulsion for ink, comprising the following steps: (1) Weigh each raw material component according to its weight; (2) adding butyl acrylate, methyl methacrylate, and modified epoxy resin to deionized water in sequence, and slowly heating to obtain a mixed solution; (3) Add emulsifier, sodium N-acylamino acid, and initiator to the mixed solution in sequence, then add pre-dissolved ultraviolet absorber, modified nano-silica, and modified hollow glass microspheres, keep warm and stir, then add dodecafluoroheptyl methacrylate and ethyl cellulose, continue stirring, and after two stages of ultrasonic treatment, continue stirring to obtain the product.

[0016] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: First, Tinuvin 1130 converts UV energy into heat through intramolecular hydrogen bonding. Its conjugated structure effectively absorbs UV photons, reducing photochemical reactions. UV absorbers reduce photoinduced hydrolysis reactions and, by optimizing molecular arrangement, reduce free volume, resulting in a denser film structure. Ultrasonic treatment for coordinated dispersion ensures uniform distribution of the additives and minimizes microporous defects. UV absorbers, through their chemical structure, capture free radicals, such as peroxyl radicals, interrupting oxidation chain reactions. Secondly, hydrophobically modified nano-silica scatters ultraviolet rays in the 280-380nm band through its high specific surface area and nanoscale particle size, reducing the depth of ultraviolet penetration. Benzotriazole ultraviolet absorbers convert the absorbed ultraviolet energy into heat energy through intramolecular hydrogen bonds, avoiding polymer chain breakage. Physical scattering and chemical absorption complement each other, forming a synergistic mechanism of ultraviolet shielding and reducing ultraviolet transmittance. Nano-silica fills the gaps between acrylate and epoxy resin chains, and nanoparticles fill the free volume between polymer chains, extending the water molecule penetration path and reducing water vapor transmission rate. Third, the hollow glass microspheres have a hollow structure that can fill the macroscopic voids in the emulsion, complementing the modified nano-silica in filling the molecular-level gaps. This creates a dense physical barrier in the emulsion system, extending the permeation path for water molecules and oxygen. Their closed-pore structure restricts liquid water penetration, and silane coupling agent treatment forms a hydrophobic layer on the surface of the microspheres, reducing affinity with the aqueous phase and reducing water adsorption. The hollow portion of the hollow glass microspheres can store heat released by Tinuvin 1130 after absorbing ultraviolet light, slowly releasing it to continuously promote water evaporation. Combined with the high thermal conductivity of nano-silica, this forms synergistic heat conduction, evenly distributing heat in the emulsion system and preventing local overheating that could lead to emulsion degradation. Fourthly, by introducing hollow glass microspheres of varying particle sizes, a multi-scale protection and barrier system can be formed within the emulsion system. Small-particle microspheres fill microscopic voids, complementing the nano-silica to reduce free volume and block the water molecule permeation pathway, thereby reducing the water molecule permeation rate and enhancing the material's barrier to water molecules. The surface of the small-particle microspheres is modified with a silane coupling agent to enhance hydrophobicity, further reducing water vapor adsorption and improving the material's water resistance. Large-particle microspheres provide a macroscopic barrier, directly blocking liquid water penetration. Their surface reflects UV light and stores heat, complementing the UV scattering effect of the nano-silica to enhance the material's UV shielding effectiveness. The hollow structure stores heat absorbed by Tinuvin 1130, delaying heat release and reducing material performance changes caused by heat concentration. A double-layer coating design, combining hollow glass microspheres of varying particle sizes and ratios, modified nano-silica (SiO2), and Tinuvin 1130, achieves micro-macro synergistic protection and layered functional optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a graph showing the effect of different amounts of ultraviolet absorbers on the ultraviolet transmittance of a paint film formed by a water-based epoxy-modified acrylate emulsion in ink in Example 1 of the present invention; Figure 2 This is a graph showing the effect of different amounts of ultraviolet absorbers on the water resistance of the paint film formed by the water-based epoxy-modified acrylate emulsion in Example 1 of the present invention. DETAILED DESCRIPTION

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains; the terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention; the term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0019] Example 1: A water-based epoxy-modified acrylate emulsion for ink is prepared from the following ingredients by weight: 32 parts of butyl acrylate, 16 parts of methyl methacrylate, 7 parts of modified epoxy resin, 2.1 parts of emulsifier, 1.3 parts of dodecafluoroheptyl methacrylate, 3 parts of ethyl cellulose, 1.4 parts of dipropylene glycol butyl ether, 2 parts of sodium N-acylamino acid, 0.8 parts of initiator, and 65 parts of deionized water; Adding an ultraviolet absorber to the emulsion, the addition amount of the ultraviolet absorber is 0.5%-2% of the total weight of the emulsion, and the ultraviolet absorber is Tinuvin 327; The modified epoxy resin preparation method comprises: (1) Lignin, deionized water and sodium sulfite were added to a reactor in sequence, stirred at a speed of 120 r / min for 40 min, and then sodium hydroxide solution was added dropwise. The reaction temperature was adjusted to 75°C, stirred for 3 hours, and allowed to stand for 2 hours. The pH of the reaction system was adjusted to 2.5 using hydrochloric acid solution, and the reaction system was centrifuged at high speed for 30 min. The reaction system was then filtered, washed with water until neutral, and dried to obtain pre-modified lignin. The mass fraction of the hydrochloric acid solution is 0.5%; (2) adjusting the solvent temperature to 80°C and keeping the temperature for 10 minutes, then adding epoxy resin and stirring until the epoxy resin is dissolved to obtain an epoxy resin solution; (3) Add the epoxy resin solution to the reactor, then add crotonic acid and catalyst, adjust the temperature to 75°C, keep stirring for 30 minutes, then add the pre-modified lignin, adjust the temperature to 112°C, and stir at 100 r / min for 2 hours; (4) After the stirring in step (3) is completed, the acid value is tested again. When the test result is less than 3 mgKOH / g, the reaction is stopped; (5) remove the solvent by distillation under reduced pressure and dry to constant weight to obtain the product.

[0020] The mixing mass ratio of the lignin, deionized water and sodium sulfite is 1:4:0.3 respectively; The mixing mass ratio of the lignin and the sodium hydroxide solution is 1:1; The mass fraction of the sodium hydroxide solution is 10%.

[0021] The solvent is propylene glycol methyl ether; The mass fraction of the epoxy resin solution is 18%.

[0022] The catalyst is dibenzoyl peroxide; The mixing mass ratio of epoxy resin solution, crotonic acid, catalyst and pre-modified lignin is 20:3:0.2:5.

[0023] The emulsifier is nonylphenol polyoxyethylene ether.

[0024] The initiator is ammonium peroxide.

[0025] The method for preparing a water-based epoxy-modified acrylate emulsion for ink comprises the following steps: (1) Weigh the raw material components according to their weight parts: butyl acrylate, methyl methacrylate, modified epoxy resin, emulsifier, dodecafluoroheptyl methacrylate, ethyl cellulose, dipropylene glycol butyl ether, sodium N-acylamino acid, initiator, and deionized water; (2) adding butyl acrylate, methyl methacrylate, and modified epoxy resin to deionized water in sequence, slowly heating, adjusting the temperature to 60° C., and stirring at a speed of 120 r / min for 2 hours to obtain a mixed solution; (3) Add emulsifier, sodium N-acylamino acid, and initiator to the mixture in sequence, then add pre-dissolved ultraviolet absorber, maintain stirring speed at 120 r / min, adjust temperature to 72°C, keep stirring for 1 hour, then add dodecafluoroheptyl methacrylate and ethyl cellulose, continue stirring for 40 minutes, and after two stages of ultrasonic treatment, continue stirring for 1 hour to obtain; The UV absorber was pre-dissolved by mixing Tinuvin 1130 and dipropylene glycol butyl ether in a mass ratio of 1:2 and stirring until completely dissolved to form a transparent solution. In the two-stage ultrasonic treatment, the first stage has an ultrasonic frequency of 40kHz and a treatment time of 15min; the second stage has an ultrasonic frequency of 30kHz and a treatment time of 20min; The method for preparing ink comprises the following steps: (1) Stir the prepared waterborne epoxy-modified acrylate emulsion and color paste until they are uniform; (2) Clean the surface of the printed substrate to ensure there is no oil or dust; (3) Use a wire rod applicator or a scraper to evenly apply the emulsion to the surface of the substrate; after coating, transfer it to an oven for drying to ensure that the water and solvent are fully evaporated to obtain the ink; Performance testing: 1. Ultraviolet transmittance: Use a UV-visible spectrophotometer (ASTM E308) to measure the transmittance in the 280-380nm band; 2. Yellowing time: Refer to ISO 4892-3 standard and record the time when the paint film turns obviously yellow in a xenon lamp aging box (irradiance 0.5 W / m², blackboard temperature 60℃); 3. Apply the sample on the surface of the glass plate, dry it, and then test the water resistance of the paint film according to GBT1733-1993; Experiments were conducted with different Tinuvin 1130 addition amounts. The Tinuvin 1130 addition amount and test results are shown in Table 1. Figure 1 and Figure 2 As shown: Table 1 The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages: As the amount of Tinuvin 1130 added increases, UV transmittance decreases. Tinuvin 1130 effectively absorbs UV rays, reducing the amount of UV rays penetrating the emulsion. UV rays are one of the main causes of oxidative degradation of components in the emulsion and yellowing of the paint film. The addition of Tinuvin 1130 can significantly prolong the yellowing time of the paint film. By absorbing UV rays, it reduces UV-induced oxidative degradation reactions, thereby delaying the yellowing process of the paint film. If the UV absorber is not fully dispersed, it will lead to decreased emulsion stability and demulsification or gelation. Through pre-dissolution and reasonable addition, Tinuvin 1130 can be evenly dispersed in the emulsion, avoiding the adverse effects of localized excessive concentration on emulsion stability. When the addition amount does not exceed 3%, the emulsion can maintain good stability. Benzotriazole UV absorbers (Tinuvin 1130) convert UV energy into heat through intramolecular hydrogen bonds. Their conjugated structure effectively absorbs UV photons, reducing photochemical reactions. UV absorbers reduce light-induced hydrolysis reactions and, by optimizing molecular arrangement, reduce free volume, resulting in a denser film structure. Ultrasonic treatment for coordinated dispersion ensures uniform distribution of the additives and minimizes microporous defects. The UV absorber's chemical structure captures free radicals, such as peroxyl radicals, interrupting oxidation chain reactions. Tinuvin 1130 exhibits excellent thermal stability below 112°C and is highly compatible with epoxy resins and emulsifiers. Predissolving in dipropylene glycol butyl ether prior to addition prevents emulsion breakage or viscosity abnormalities caused by uneven dispersion. When exposed to ultraviolet light, Tinuvin 1130 molecules absorb ultraviolet energy and transition from the ground state to an excited state. Subsequently, through intramolecular energy conversion, the energy is released in the form of heat, thereby preventing ultraviolet light from damaging polymer molecules in the emulsion, such as the polymer chains formed by butyl acrylate and methyl methacrylate, as well as modified epoxy resins. The effective effect of Tinuvin 1130 in emulsions depends on its good dispersibility. By pre-dissolving it in dipropylene glycol butyl ether, the solubility of dipropylene glycol butyl ether in Tinuvin 1130 is utilized to form a uniform solution. During the emulsion preparation process, the pre-dissolved Tinuvin 1130 solution is added and, with the help of stirring and ultrasonic treatment, it can be evenly dispersed in the emulsion system. It has good compatibility with other ingredients in the emulsion, preventing emulsion stratification or demulsification due to compatibility issues, and avoiding the problem of localized excessive concentration leading to decreased emulsion stability. Due to the anti-UV effect of Tinuvin 1130, emulsion products can better resist the erosion of ultraviolet rays when used outdoors, reducing problems such as oxidative degradation, chalking, and discoloration caused by UV exposure, thereby extending the service life of the emulsion products. Within a certain addition range (0.5%-2%), the addition of Tinuvin 1130 can enhance the water resistance of the emulsion. Tinuvin 1130 reduces the generation of free radicals triggered by UV rays, thereby enhancing the density of the paint film and improving water resistance. For applications such as outdoor printed materials that require high UV protection, emulsions containing Tinuvin 1130 can provide better UV resistance, meeting the needs of these fields and thus expanding the application range of the emulsion.

[0026] Example 2: The above example 1 achieves the effects of reducing UV transmittance, prolonging yellowing time, and improving water resistance by adding Tinuvin 1130, thereby improving the stability of printing quality. In order to further improve its stability, further improvements are made on the basis of example 1.

[0027] Modified nano-silica is also added to the emulsion, and the amount of modified nano-silica added is 1%-3% of the total weight of the emulsion; The surface of nano-silica is modified by silane to form a hydrophobic layer, thereby obtaining modified nano-silica; the particle size of the nano-silica is 10-20 nm, and the silane is octadecyltrimethoxysilane; The weight of the emulsifier is increased to 3.5 parts; When adding the pre-dissolved ultraviolet absorber in step (3), the modified nano-silica is added simultaneously, and the pre-dissolved modified nano-silica is slowly dripped into the mixed solution, maintaining a stirring speed of 120 r / min to avoid excessive local concentration; The pre-dissolution of the modified nano-silica is as follows: the modified nano-silica is mixed with propylene glycol methyl ether in a mass ratio of 1:5, and dispersed by ultrasonic wave (40kHz, 30min) to a particle size of <100 nm to form a stable suspension.

[0028] The experiment was conducted based on the addition of 2% Tinuvin 1130 in Example 1. The addition amount of modified nano-silica and the test results are shown in Table 2 below: Table 2 The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages: With increasing addition of modified nano-silica, UV transmittance gradually decreased, indicating that the physical scattering of the nanoparticles and the chemical absorption of Tinuvin 1130 form a synergistic effect, significantly enhancing UV shielding ability. Yellowing time is prolonged, thanks to the high thermal conductivity of the nanoparticles, which accelerates heat diffusion, reduces water retention, and delays photooxidation reactions. Water resistance is improved because the nanoparticles fill the molecular gaps and form a hydrophobic barrier. However, excessive addition (4%) leads to uneven dispersion and microcracks, which reduces water resistance. Hydrophobically modified nanosilica (10-20 nm) scatters UV rays in the 280-380 nm band through its high specific surface area and nanoscale particle size, reducing UV penetration depth. Benzotriazole UV absorbers convert absorbed UV energy into thermal energy release through intramolecular hydrogen bonds, preventing polymer chain breakage. Physical scattering and chemical absorption complement each other, forming a synergistic mechanism for UV shielding and reducing UV transmittance. Nanosilica fills the gaps between acrylate and epoxy resin chains, while nanoparticles fill the free volume between polymer chains, extending the water molecule permeation path and reducing water vapor transmission rate. Surface silane-modified nanoparticles form a hydrophobic layer that blocks liquid water penetration. UV absorbers inhibit light-induced hydrolysis reactions and reduce the hydrophilicity of polymer chains, thereby enhancing water resistance. The high thermal conductivity of nanosilica promotes the rapid diffusion of heat energy generated by Tinuvin 1130, accelerating water evaporation and shortening drying time, making it suitable for fast printing applications. The addition of modified nano-silica improves the stability, UV resistance and water resistance of the emulsion. Due to the improvement of the emulsion performance, the stability of printing quality is improved. During the printing process, the emulsion can better adhere to the printing substrate, reducing printing defects caused by ultraviolet rays and moisture, such as fading and blurring, thereby improving the quality and durability of printed products; the improved emulsion has better UV resistance and water resistance, and is suitable for occasions with high requirements on printing quality and relatively harsh use environments, such as outdoor advertising, packaging printing, etc., which expands the application range of the emulsion; by reducing UV transmittance and delaying yellowing time, the service life of printed products is extended, and the high thermal conductivity of nano-silica promotes rapid diffusion of heat energy, accelerates water evaporation, and shortens drying time, so it can be used for fast printing and improves production efficiency.

[0029] Example 3: In the above-mentioned Example 2, modified nano-silica is introduced on the basis of adding Tinuvin 1130 in Example 1. Through the synergistic effect of physical scattering of nanoparticles and chemical absorption of Tinuvin 1130, high thermal conductivity accelerates heat diffusion, and filling molecular gaps to form a hydrophobic barrier, the ultraviolet transmittance is reduced, the yellowing time is prolonged, and the water resistance is improved, thereby improving the performance of the emulsion and thus improving the stability of the printing quality. In order to further improve its stability, further improvements are made on the basis of Example 2.

[0030] Modified hollow glass microspheres are also added to the emulsion; the mass ratio of modified nano-silica to modified hollow glass microspheres is 1:(3-4); Hollow glass microspheres and a silane coupling agent are mixed in a mass ratio of 10:1, and anhydrous ethanol is added so that the mass ratio of the hollow glass microspheres to the anhydrous ethanol is 1:5; the mixture is reacted at 60°C for 2 hours, washed by centrifugation, and dried at 60°C to obtain hydrophobically modified hollow glass microspheres; the particle size of the hollow glass microspheres is 10-15 μm; The modified hollow glass microspheres are pre-dissolved by mixing the modified hollow glass microspheres with dipropylene glycol butyl ether in a mass ratio of 1:4, and stirring at a speed of 80-100 rpm for 10 minutes to form a uniform modified hollow glass microsphere suspension; The weight of the initiator is increased to 1.2 parts; In step (3), an emulsifier, sodium N-acylamino acid, an initiator, and a pre-dissolved modified nano-silica solution are sequentially added to the mixed solution; Then add the pre-dissolved modified hollow glass spheres and stir at 80-100 rpm for 5 minutes to avoid breaking the microspheres; Add the pre-dissolved Tinuvin 1130 solution and keep stirring at 120 rpm; Adjust the temperature to 72°C, keep stirring for 1 hour, then add dodecafluoroheptyl methacrylate and ethyl cellulose, continue stirring for 40 minutes, and continue stirring for 1 hour after two stages of ultrasonic treatment. The first of the two ultrasonic treatments was at 40 kHz for 20 minutes to disperse nano-silica; the second was at 30 kHz for 25 minutes to disperse hollow glass microspheres. The experiment was conducted based on the modified nano-silica addition amount (wt%) of 3% in Example 2. The addition amount of the modified hollow glass microspheres and the test results are shown in Table 3 below: Table 3 The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages: As can be seen from the above table, the UV transmittance is further reduced, the yellowing time is prolonged, and the water resistance is improved; the hollow glass microspheres have a hollow structure, which can fill the macroscopic voids in the emulsion, complementing the modified nano-silica filling the molecular-level gaps, building a dense physical barrier in the emulsion system, extending the permeation path of water molecules and oxygen, and its closed-pore structure restricts the penetration of liquid water. After treatment with silane coupling agents, a hydrophobic layer is formed on the surface of the microspheres, reducing the affinity with the water phase and reducing water adsorption; the macroscopic size of the microspheres can directly block the penetration of liquid water, while the modified hydrophobic surface further reduces water vapor adsorption, fills the gaps between polymer chains, reduces the mobility of molecular segments, and thus inhibits the diffusion of water molecules; the hollow part of the hollow glass microspheres can store Tinuvin After absorbing ultraviolet light, 1130 releases heat slowly to continuously promote water evaporation. Combined with the high thermal conductivity of nano-silica, this creates synergistic heat conduction, evenly distributing heat throughout the emulsion system and preventing local overheating that could lead to emulsion degradation. This heat storage mechanism makes the drying process more uniform, shortens drying time, and avoids cracks in the paint film caused by rapid drying. The smooth surface of the hollow glass microspheres can reflect some ultraviolet light, reducing direct exposure to epoxy resin and acrylate molecules. This complements the chemical absorption of Tinuvin 1130, creating a dual protection of reflection and absorption. By controlling the specific stirring speed and time, the modified hollow glass microsphere suspension is ensured to be evenly dispersed in the emulsion system, thus preventing the microspheres from breaking and ensuring the stability and performance of the system. The two-stage ultrasonic treatment is used to disperse the nano-silica and hollow glass microspheres respectively, improving the dispersion effect and making each component evenly distributed in the emulsion to give full play to its role. Enhanced UV protection and anti-yellowing properties enable printed materials to maintain color stability and appearance quality for a longer period of time during use, reducing fading and discoloration problems caused by UV radiation; improved water resistance enables printed materials to better maintain performance stability in humid environments, avoid problems such as shedding and blistering caused by moisture erosion, and improve product durability; the uniform drying process can reduce defects such as paint film cracks and sagging that occur during the printing process, improve the surface quality and gloss of printed materials, and the stable emulsion performance makes the printing process smoother, reduces printing failures caused by emulsion performance fluctuations, and improves printing efficiency and production stability; the improved emulsion system has more excellent performance and can meet application scenarios with higher requirements for UV protection, water resistance and printing quality, such as outdoor advertising, architectural decoration, car film and other fields.

[0031] Example 4: Based on the modified nano-silica introduced in Example 2, the above Example 3 further introduces hollow glass microspheres to further reduce the ultraviolet transmittance, extend the yellowing time, and improve water resistance, thereby improving the emulsion performance and thus improving the stability of printing quality. In order to further improve its stability, further improvements are made on the basis of Example 3.

[0032] Hollow glass microspheres include large particle size 1-5μm and small particle size 0.1-1μm, and the mass ratio of small particle size to large particle size is 2:3; Modified nano-silica and small-size hollow glass microspheres were mixed in a mass ratio of 1:1, propylene glycol methyl ether (mass ratio of 1:5) was added, and ultrasonic treatment (40 kHz / 20 min) was performed to form a composite suspension; Large-size hollow glass microspheres were mixed with dipropylene glycol butyl ether (mass ratio 1:4) and stirred at low speed (80 rpm / 10 min) to avoid breakage; In the emulsion preparation step (3), the composite suspension and the large-diameter hollow glass microsphere suspension are added in sequence; The first of the two ultrasonic treatments was 40 kHz for 25 minutes, and the second was 30 kHz for 30 minutes. The experiment was conducted based on the modified hollow glass microspheres and modified nano-silica in Example 3 with a mass ratio of 1:4. The test results showed that the ultraviolet transmittance (280-380nm) was 20%, the yellowing time (h) was 290h, and the water resistance (h) was 140h. The ink also includes two emulsion coating layers, wherein the mass ratio of modified nano-silica to modified hollow glass microspheres in the first coating layer is 1:(3-4), the hollow glass microspheres include large particles with a diameter of 1-5 μm and small particles with a diameter of 0.1-1 μm, and the mass ratio of the small particle size to the large particle size is 2:3; The mass ratio of modified nano-silica to modified hollow glass microspheres in the second coating layer is 1:1.5; the hollow glass microspheres include small particles with a diameter of 0.1-1 μm and ultra-large particles with a diameter of 10-15 μm, and the mass ratio of small particles to large particles is 3:7; Based on the above experiments, further experiments were conducted, two layers were applied, and tests were performed; the test results showed that the UV transmittance (280-380nm) was 13%, the yellowing time (h) was 350h, and the water resistance (h) was 165h.

[0033] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages: By introducing hollow glass microspheres of different particle sizes, a multi-scale protection and barrier system can be formed in the emulsion system. Small-particle microspheres fill microscopic gaps, complement nano-silica, reduce free volume, block the water molecule penetration path, thereby reducing the water molecule penetration rate and enhancing the material's barrier ability to water molecules; the surface of small-particle microspheres is modified with silane coupling agents to enhance hydrophobicity, further reduce the adsorption of water vapor, and improve the material's water resistance; large-particle microspheres provide macroscopic barriers, directly blocking liquid water penetration, and their surface can reflect ultraviolet rays and store heat. Complementing the ultraviolet scattering effect of nano-silica, it enhances the material's shielding effect against ultraviolet rays. The hollow structure stores heat absorbed by Tinuvin 1130, delaying heat release and reducing changes in material properties caused by heat concentration. The combination of small and large particle sizes balances microscopic filling and macroscopic barrier properties, creating a synergistic effect and forming a multi-scale protection and barrier system. The small particle size is pre-dispersed by blending with nano-silica, while the large particle size is processed independently to prevent the breakage of large-particle microspheres and the aggregation of small-particle microspheres, ensuring uniform distribution of the microspheres in the material and stable performance. Nano-silica and small-particle glass microspheres together fill the molecular gaps and reduce the free volume. At the same time, large-particle glass microspheres form a macroscopic physical barrier to block the penetration of liquid water. This allows printed materials to maintain good performance in humid environments, making them less likely to deform or fade due to water absorption, thereby extending the service life of printed materials. Nano-silica scatters ultraviolet rays, large-particle glass microspheres reflect ultraviolet rays, and ultraviolet absorbers absorb ultraviolet rays and convert them into heat energy. The three work synergistically to further enhance the protection against ultraviolet rays and effectively reduce the damage of ultraviolet rays to the color of printed materials. Through a double-layer coating design, combined with hollow glass microspheres of different particle sizes and ratios, modified nano-silica and Tinuvin 1130, micro-macro synergistic protection and functional layered optimization are achieved; The first layer of small-particle hollow glass microspheres and modified nano-silica work together to fill the molecular gaps, reduce the free volume, and extend the water molecule penetration path. Its function is to enhance the density of the material from a microscopic level, provide a basis for subsequent protection, effectively block the invasion of water molecules, and improve the water resistance of the material; the large-particle hollow glass microspheres initially store heat and reflect some ultraviolet rays. The heat storage function can store heat when the material absorbs it, avoiding local overheating; reflecting ultraviolet rays can reduce the direct exposure of ultraviolet rays to the material, reduce the risk of material aging due to ultraviolet radiation, and extend the service life of the material; The small-sized hollow glass microspheres in the second coating layer fill the remaining voids in the bottom layer, enhancing hydrophobicity and further optimizing the material's microstructure. This enhances the surface's hydrophobicity, making it less susceptible to water wetting and improving water resistance. The ultra-large hollow glass microspheres act as the heat storage core, blocking liquid water penetration and reflecting ultraviolet rays. The ultra-large hollow structure enhances their heat storage capacity, enabling them to effectively store heat and release it slowly. At the same time, their larger size can physically block liquid water penetration, and their ultraviolet reflection function synergizes with the underlying large-sized microspheres to provide more comprehensive UV protection. The first layer of nano-silica scatters UV rays, while the large-particle hollow glass microspheres partially reflect them. The second layer of ultra-large-particle hollow glass microspheres further reflect UV rays, forming a multi-layered UV protection system that significantly reduces UV transmittance. The small-particle hollow glass microspheres and nano-silica in the two layers jointly fill the molecular gaps, reducing free volume. The large-particle and ultra-large-particle hollow glass microspheres form physical barriers at different levels. Tinuvin 1130 releases heat after absorbing UV rays, while the ultra-large-particle hollow glass microspheres store heat. The nano-silica conducts heat and accelerates the uniform distribution of heat, avoiding local overheating that may cause cracking of the paint film, while shortening the drying time. Through the regulation of two layers of hollow glass microspheres with different particle sizes and dosages, micro-macro synergistic protection is achieved, significantly improving the UV protection and water resistance of ink printed products, allowing printed products to maintain good condition for a long time in harsh outdoor environments, further expanding the product's application areas.

[0034] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Various modifications and variations are readily apparent to those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A water-based epoxy-modified acrylate emulsion for ink, characterized in that: The composition is made from the following ingredients by weight: 32 parts of butyl acrylate, 16 parts of methyl methacrylate, 7 parts of modified epoxy resin, 2.1 parts of emulsifier, 1.3 parts of dodecafluoroheptyl methacrylate, 3 parts of ethyl cellulose, 1.4 parts of dipropylene glycol butyl ether, 2 parts of sodium N-acylamino acid, 0.8 parts of initiator, and 65 parts of deionized water; The emulsion also includes a UV absorber, modified nano-silica, and modified hollow glass microspheres; Among them, the addition amount of ultraviolet absorber is 0.5%-2% of the total weight of the emulsion; The amount of modified nano-silica added is 1%-3% of the total weight of the emulsion; The mass ratio of modified nano-silica to modified hollow glass microspheres is 1:(3-4).

2. The aqueous epoxy-modified acrylate emulsion for ink according to claim 1, wherein: The ultraviolet absorber is Tinuvin 327.

3. The aqueous epoxy-modified acrylate emulsion for ink according to claim 1, wherein: The preparation method of the modified nano-silica comprises the following steps: modifying the surface of the nano-silica with silane to form a hydrophobic layer to obtain the modified nano-silica; the particle size of the nano-silica is 10-20 nm, and the silane is octadecyltrimethoxysilane.

4. The aqueous epoxy-modified acrylate emulsion for ink according to claim 1, wherein The preparation method of the modified hollow glass microspheres comprises the following steps: mixing the hollow glass microspheres with a silane coupling agent, adding anhydrous ethanol for reaction, washing by centrifugation, and drying to obtain hydrophobically modified hollow glass microspheres; the particle size of the hollow glass microspheres is 20-40 μm.

5. The aqueous epoxy-modified acrylate emulsion for ink according to claim 4, wherein: The hollow glass microspheres further include large particle sizes of 1-5 μm and small particle sizes of 0.1-1 μm, and the mass ratio of the small particle size to the large particle size is 2:

3.

6. The aqueous epoxy-modified acrylate emulsion for ink according to claim 1, wherein: The added amount of the ultraviolet absorber is 0.5%-2% of the total weight of the emulsion, preferably 2%; the added amount of the modified nano-silica is 1%-3% of the total weight of the emulsion, preferably 3%; the mass ratio of the modified nano-silica to the modified hollow glass microspheres is 1:(3-4), preferably 1:

4.

7. The aqueous epoxy-modified acrylate emulsion for ink according to claim 1, wherein: Inking also includes applying one or more layers of emulsion.

8. The aqueous epoxy-modified acrylate emulsion for ink according to claim 7, wherein: The ink comprises two layers of emulsion, namely a first coating layer and a second coating layer. The particle sizes and proportions of the hollow glass microspheres in the first coating layer and the second coating layer are different.

9. The aqueous epoxy-modified acrylate emulsion for ink according to claim 8, wherein: The mass ratio of modified nano-silica to modified hollow glass microspheres in the first coating layer is 1:(3-4), the hollow glass microspheres include large particles with a diameter of 1-5 μm and small particles with a diameter of 0.1-1 μm, and the mass ratio of small particles to large particles is 2:3; The mass ratio of modified nano-silica to modified hollow glass microspheres in the second coating layer is 1:1.5; the hollow glass microspheres include small particles with a diameter of 0.1-1 μm and ultra-large particles with a diameter of 10-15 μm, and the mass ratio of small particles to large particles is 3:

7.

10. A method for preparing the aqueous epoxy-modified acrylate emulsion for ink according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Weigh each raw material component according to its weight; (2) adding butyl acrylate, methyl methacrylate, and modified epoxy resin to deionized water in sequence, and slowly heating to obtain a mixed solution; (3) Add emulsifier, sodium N-acylamino acid, and initiator to the mixed solution in sequence, then add pre-dissolved ultraviolet absorber, modified nano-silica, and modified hollow glass microspheres, keep warm and stir, then add dodecafluoroheptyl methacrylate and ethyl cellulose, continue stirring, and after two stages of ultrasonic treatment, continue stirring to obtain the product.

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