Tempered glass digital printing ink and preparation method thereof

Abstract

The invention relates to the field of glass ink, in particular to tempered glass digital printing ink and a preparation method thereof.The tempered glass digital printing ink is prepared from, by weight, 24-40 parts of glass solvent, 8-12 parts of inorganic pigment, 40-48 parts of DES, 5-10 parts of propylene glycol, 2-6 parts of deionized water, 1-4 parts of polyvinyl alcohol, 0.1-0.5 part of borax, 0.3-1 part of Laponite RD, 0.5-1 part of dispersing agent, 0.1-0.3 part of flatting agent and 0.01-0.08 part of defoaming agent. A dynamic coordination network is constructed through coordination of polyvinyl alcohol and borax, a house-plate framework network is constructed through Laponite RD and interpenetrates with a weak cross-linked network of PVA-borax, the effect that tempered glass digital printing ink does not sink after standing is achieved, high viscosity, high wettability and low volatility are provided through addition of DES, the DES cooperates with polyvinyl alcohol and Laponite RD, and the printing ink has the advantages of high viscosity, high wettability and low volatility. A more stable system is jointly constructed, and the tempered glass digital printing ink with excellent performance is prepared.

Description

Technical Field

[0001] This application relates to the field of glass inks, and more particularly to a tempered glass digital printing ink and a method for preparing the same. Background Technology

[0002] Tempered glass digital printing ink is mainly composed of inorganic pigments, glass solvents, binders, and additives. Among them, the particle size of inorganic pigments and glass solvents is usually less than 1μm, which makes them prone to agglomeration and precipitation in the binder. This can clog and damage the printer nozzles, affecting the printing effect.

[0003] To achieve uniform dispersion of inorganic pigments, dispersants are often added to the binder in the preparation of tempered glass digital printing inks. Dispersants mainly include inorganic dispersants and organic dispersants. Inorganic dispersants mainly maintain the stability of tempered glass digital printing inks by generating charged particles that adsorb onto the surface of inorganic pigments, causing electrostatic repulsion between the inorganic pigment particles. Organic dispersants mainly maintain the stability of the dispersion system through steric hindrance.

[0004] However, due to the small particle size of glass solvents and inorganic pigments, their theoretical settling velocity in ordinary liquids is very slow. However, their large surface energy causes them to aggregate, accelerating the settling process. Therefore, to achieve the effect of particles remaining stationary without settling, it is necessary to construct a weakly gel continuous phase with yield stress. Summary of the Invention

[0005] To improve the non-settling effect of tempered glass digital printing ink, this application provides a tempered glass digital printing ink and its preparation method.

[0006] Firstly, this application provides a tempered glass digital printing ink, which adopts the following technical solution: A tempered glass digital printing ink comprises the following components in parts by weight: 24-40 parts glass solvent, 8-12 parts inorganic pigment, 40-48 parts DES, 5-10 parts propylene glycol, 2-6 parts deionized water, 1-4 parts polyvinyl alcohol, 0.1-0.5 parts borax, 0.3-1 part Laponite RD, 0.5-1 part dispersant, 0.1-0.3 parts leveling agent, and 0.01-0.08 parts defoamer.

[0007] By employing the above technical solution, borax, when dissolved in water, hydrolyzes to generate borate ions, which coordinate with the hydroxyl groups on the long chain of polyvinyl alcohol to form reversible diol-boronate bonds, constructing a weakly cross-linked network. This allows the tempered glass digital printing ink to exhibit "shear-thinning" behavior. The addition of Laponite RD, after dispersion in water, forms a three-dimensional "roof-and-plate" framework network, preventing the sedimentation of solid particles such as glass solvents and inorganic pigments in the system. Furthermore, the "roof-and-plate" framework network formed by Laponite RD can interpenetrate with the weakly cross-linked network of PVA-borax, forming a more stable and robust three-dimensional structure, significantly improving the thixotropic properties of the tempered glass digital printing ink. Furthermore, by using DES instead of traditional organic solvents as the main medium, DES provides high viscosity, strong wettability, and low volatility, while also exhibiting low ash content and clean ablation during firing. Additionally, the numerous hydrogen bonds in DES can interact with polyvinyl alcohol and Laponite... RD forms secondary hydrogen bonds, enabling the three to form a network. Through the combination of the above raw materials, high-performance tempered glass digital printing ink is produced, achieving the effects of tempered glass digital printing ink not settling when standing, running smoothly when sheared, flattening quickly when shearing stops, and then edge locking.

[0008] This application constructs a dynamic coordination network by coordinating polyvinyl alcohol and borax, enabling tempered glass digital printing ink to exhibit "shear-thinning" behavior. Furthermore, a "house-and-brand" framework network built with Laponite RD prevents the sedimentation of solid particles such as glass solvents and inorganic pigments in the system. When the "house-and-brand" framework network formed by Laponite RD interpenetrates with the weakly cross-linked network of PVA-borax, the tempered glass digital printing ink achieves a non-settling effect upon standing. The addition of DES provides high viscosity, strong wettability, and low volatility, and synergistically with polyvinyl alcohol and Laponite RD to construct a more stable system, thereby producing a high-performance tempered glass digital printing ink.

[0009] Preferably, the degree of hydrolysis of the polyvinyl alcohol is 88-90%, and the degree of polymerization of the polyvinyl alcohol is 1500-2000.

[0010] By adopting the above technical solution, when the hydrolysis level of polyvinyl alcohol is too low, the number of hydrophobic acetyl groups on the polyvinyl alcohol molecular chain increases, which reduces the number of hydroxyl groups that can coordinate with borax, resulting in a decrease in the strength of the PVA-borax weak crosslinking network and a decrease in the thixotropic effect, making the solid particles in the system more prone to sedimentation. When the hydrolysis level of polyvinyl alcohol is too high, the number of hydroxyl groups on the polyvinyl alcohol molecular chain is too large, and the crosslinking points of the diol-boron ester formed with borax are too dense, resulting in an excessively rigid PVA-borax network with poor dynamic reversibility, which weakens the "shear thinning" behavior of tempered glass digital printing ink.

[0011] When the polymerization rate of polyvinyl alcohol is too low, the molecular chains of polyvinyl alcohol are too short, resulting in a weak and inelastic PVA-borax network formed by crosslinking with borax. This network cannot effectively support the suspension of solid particles in the system. Furthermore, the network constructed by short-chain polyvinyl alcohol is not spatially extended enough to form an effective, interpenetrating, and mutually reinforcing three-dimensional structure with the Laponite RD backbone network, thus reducing the thixotropic properties of tempered glass digital printing ink. When the polymerization rate of polyvinyl alcohol is too high, the viscosity of tempered glass digital printing ink becomes too high, and the speed of untangling and retangling of long-chain molecules is slow. This leads to a sluggish dynamic response in "shear thinning" and "structural recovery," which is not conducive to high-speed printing or spraying processes.

[0012] Preferably, the molar ratio of polyvinyl alcohol to boron atoms in borax is (10-14):1.

[0013] By adopting the above technical solution, when polyvinyl alcohol is relatively excessive, the insufficient amount of borax leads to too few diol-boron ester crosslinking points, resulting in a sparse and weak dynamic crosslinking network between polyvinyl alcohol molecular chains. This causes a decrease in the thixotropy of the tempered glass digital printing ink, making solid particles prone to sedimentation. Under shear action, the network is easily dissociated, but the viscosity drops significantly, resulting in poor workability due to "shear-resistant" properties. When polyvinyl alcohol is relatively small, the amount of borax added is relatively excessive, resulting in overly dense crosslinking points, rigid orientation of the dynamic crosslinking network, and poor dynamic reversibility, thus weakening the "shear-thinning" behavior of the tempered glass digital printing ink.

[0014] Preferably, the hydrogen bond donor of the DES is glycerol, and the hydrogen bond acceptor is choline chloride.

[0015] By adopting the above technical solution, glycerol molecules contain three hydroxyl groups, which are strong hydrogen bond donors, and chloride ions in choline chloride are good hydrogen bond acceptors. The combination of the two can form a dense and stable hydrogen bond network. Furthermore, the formed hydrogen bond network can form secondary hydrogen bonds with PVA, SiO2 surface -SiOH, and Laponite edge -Mg-OH, making it easier for the three to form a through network and jointly construct a more robust three-dimensional structure.

[0016] Glycerin itself has high viscosity, and the DES formed with choline chloride provides the basic viscosity required for tempered glass digital printing inks. Furthermore, this DES system has low surface tension and strong wetting ability, enabling it to form hydrogen bonds or Lewis acids with ≡Si-OH on the glass surface and -M-OH on the metal oxide surface, allowing the tempered glass digital printing ink to spread evenly on a smooth glass surface. Simultaneously, as a medium, DES is well-compatible with glass solvents, inorganic pigments, and other components, facilitating the formation of a uniform suspension system and promoting a dense ink film during the drying process.

[0017] Preferably, the molar ratio of glycerol to propylene glycol is (2-4):1.

[0018] By employing the above technical solutions, when the amount of glycerol added is relatively excessive, the viscosity of DES becomes too high, the hydrogen bond network becomes too dense, interfering with the reversibility of the PVA-borax dynamic coordination network and weakening the "shear thinning" response sensitivity. When the amount of glycerol added is relatively insufficient, the amount of propylene glycol added is excessive. Due to the weak hydrogen bonding ability of propylene glycol, excessive amounts will dilute the strong hydrogen bond environment of DES and weaken its secondary hydrogen bond interactions with PVA and Laponite RD, leading to a loosening of the "through-network" structure. The ink's ability to suspend solid particles decreases when stationary, making sedimentation more likely.

[0019] Preferably, a tempered glass digital printing ink also contains fumed silica.

[0020] By adopting the above technical solution, the surface of fumed silica is rich in silanol groups, which can form a dense hydrogen bond network with hydroxyl and chloride ions in DES, the remaining hydroxyl groups on the polyvinyl alcohol chain, and the -Mg-OH groups on the edge of the Laponite RD sheet and the negatively charged sites on the surface. When fumed silica is distributed at the intersection of the PVA-borax network and the Laponite RD framework network, the strong multi-point hydrogen bonding ability of fumed silica can anchor the originally loose intersections together to form a reinforced node.

[0021] When stationary, fumed silica can act as a "structural reinforcing agent," strengthening network nodes, providing stronger support and a more defined solid-fluid transition threshold, thus improving the anti-settling effect. When sheared, fumed silica can act as a "sacrificial connection point," its weak interaction properties allowing it to quickly "give way" when flow is needed, thereby achieving a "shear-thinning" effect.

[0022] Preferably, the amount of fumed silica added is 0.1-0.4 parts.

[0023] By adopting the above technical solutions, when the amount of fumed silica added is too small, the intersection of the PVA-borax network and the Laponite RD skeleton network cannot be effectively riveted and reinforced, resulting in limited improvement in the structural strength of the three-dimensional network. Consequently, when the tempered glass digital printing ink is left to stand for a long time, the supporting force of the solid particles in the system mainly comes from the original network, which reduces the anti-settling effect. Furthermore, after shearing stops, the recovery of the tempered glass digital printing ink structure mainly comes from the slow recombination of PVA-borax dynamic bonds and the rearrangement of Laponite layers, resulting in an unsatisfactory recovery speed and affecting the fineness of the pattern. When the amount of fumed silica added is too large, the excess fumed silica will form its own dense hydrogen bond network. This hydrogen bond network will adsorb DES, polyvinyl alcohol, and Laponite, restricting the reversible breaking and recombination of PVA-borax dynamic covalent bonds, making it difficult for the viscosity of the tempered glass digital printing ink to decrease under high shear.

[0024] Preferably, the dispersant is at least one of phosphate ester and polyacrylate.

[0025] By adopting the above technical solution, the phosphate groups in the phosphate ester molecular structure have extremely strong polarity and can be firmly anchored to the surface of solid particles such as glass solvents and inorganic pigments through chemical adsorption or hydrogen bonding. The surface of these particles is usually rich in metal oxides, and the hydroxyl or metal sites on them can form a stable bond with the phosphate groups. Furthermore, the alkyl chains of the phosphate ester extend into the DES medium. When the particles approach each other, these alkyl chains adsorbed on the particle surface repel each other, generating a steric hindrance effect, preventing the particles from agglomerating and settling due to van der Waals forces.

[0026] Polyacrylate molecules contain a large number of carboxylate groups, which can be adsorbed at multiple points on the particle surface to form "anchored segments". The unadsorbed long chain portions extending into the solution form a thick polymer solvation layer. When two particles wrapped by polymer chains approach each other, these polymer layers compress and overlap each other, resulting in a reduction in the conformational entropy of the chain segments and generating a strong steric repulsion force, which effectively prevents the aggregation of solid particles.

[0027] By compounding phosphate esters and polyacrylates into a dispersant, phosphate esters can rapidly adsorb onto the surface of solid particles such as glass solvents and inorganic pigments in DES media, achieving rapid wetting and initial dispersion. Polyacrylates, on the other hand, have a relatively slower adsorption rate, but their long chains can form a thick protective layer, providing extremely strong long-term steric hindrance. Furthermore, phosphate esters provide the first strong anchoring point through strong chemisorption, while polyacrylates provide a second anchoring point through adsorption via multiple carboxyl groups, making the dispersant adhere more firmly to the surface of solid particles.

[0028] Secondly, this application provides a method for preparing tempered glass digital printing ink, which adopts the following technical solution: A method for preparing tempered glass digital printing ink includes the following steps: S1. Add the prescribed amounts of propylene glycol and deionized water to DES and mix thoroughly to obtain DES base solution; S2. Add the prescribed amount of Laponite RD to the DES base liquid, shear and disperse it, then add the prescribed amount of polyvinyl alcohol under stirring, and stir to obtain a mixed system. S3. Add the prescribed amount of borax to the mixing system, adjust the pH to 8.6-9.2, let it stand and stir, then add the prescribed amount of dispersant, glass solvent and inorganic pigment in sequence, and disperse evenly to obtain a pre-dispersed slurry; S4. The pre-dispersed slurry is bead milled to obtain bead milled slurry. The formulated amount of leveling agent and defoamer is then added to the bead milled slurry. After stirring evenly, vacuum degassing and filtration are performed, and the mixture is allowed to stand to obtain tempered glass digital printing ink.

[0029] By adopting the above technical solution, DES is prepared with propylene glycol and water to form a DES base liquid, which can provide a dispersion medium for subsequent components. Laponite RD can form a skeletal network in water, providing yield stress. The addition of polyvinyl alcohol can crosslink with the skeletal network of Laponite RD, and at the same time, it can form reversible glycol-boron ester bonds with the subsequently added borax under the condition of pH 8.6-9.2, forming a weak crosslinked network of PVA-borax that interpenetrates with the skeletal network formed by Laponite RD, forming a more stable and robust three-dimensional structure, improving the thixotropic properties of tempered glass digital printing ink. Finally, the pre-dispersed slurry is bead milled to refine the particle size, and then leveling agent and defoamer are added, followed by vacuum degassing to obtain a high-performance tempered glass digital printing ink.

[0030] Preferably, in step S3, the formulated amount of borax is added to the mixing system, the pH is adjusted to 8.6-9.2, and after standing and stirring, the formulated amounts of fumed silica, dispersant, glass solvent and inorganic pigment are added in sequence. After being dispersed evenly, a pre-dispersed slurry is obtained.

[0031] By adopting the above technical solution, fumed silica added to S3 will undergo hydrogen bonding in a weakly alkaline environment to form a three-dimensional network structure, which interpenetrates with the weakly cross-linked network of PVA-borax and the Laponite RD skeleton network, further improving the yield stress and thixotropy of the system.

[0032] In summary, this application includes at least one of the following beneficial technical effects: 1. This application constructs a dynamic coordination network through the coordination of polyvinyl alcohol and borax, enabling the tempered glass digital printing ink to exhibit "shear-thinning" behavior. Then, through the "house-brand" framework network built by Laponite RD, the sedimentation of solid particles such as glass solvent and inorganic pigments in the system is prevented. When the "house-brand" framework network formed by Laponite RD interpenetrates with the weak cross-linking network of PVA-borax, the tempered glass digital printing ink achieves the effect of not settling when standing. Furthermore, the addition of DES provides high viscosity, strong wettability, and low volatility, and works synergistically with polyvinyl alcohol and Laponite RD to jointly construct a more stable system, thereby obtaining a high-performance tempered glass digital printing ink. 2. This application adjusts the molar ratio of glycerol to propylene glycol to be within the range of (2-4):1. When the amount of glycerol added is relatively excessive, the viscosity of DES becomes too high, the hydrogen bond network becomes too dense, interfering with the reversibility of the PVA-borax dynamic coordination network and weakening the response sensitivity of "shear thinning". When the amount of glycerol added is relatively insufficient, the amount of propylene glycol added is excessive. Due to the weak hydrogen bonding ability of propylene glycol, excessive amounts will dilute the strong hydrogen bond environment of DES and weaken its secondary hydrogen bond interaction with PVA and Laponite RD, resulting in a loosening of the "through-network" structure. The ink's ability to suspend solid particles decreases when it stands, making it prone to sedimentation. 3. By adding fumed silica, the surface of which is rich in silanol groups, this application can form a dense hydrogen bond network with hydroxyl and chloride ions in DES, the remaining hydroxyl groups on the polyvinyl alcohol chain, and the -Mg-OH groups on the edge of the Laponite RD sheet and the negatively charged sites on the surface. When fumed silica is distributed at the intersection of the PVA-borax network and the Laponite RD framework network, the strong multi-point hydrogen bonding ability of fumed silica can anchor the originally loose intersections together to form a reinforced node. Detailed Implementation

[0033] The raw materials in this application include the following: Glass solvent: The glass solvent of this application is composed of the following components: 30% silicon oxide, 35.75% bismuth oxide, 11.2% boron oxide, 11.7% zinc oxide, 2.5% titanium oxide, 6.8% sodium oxide, and 2.05% lithium oxide, which are commercially available products purchased from Dormad Xiamen Fine Chemical Co., Ltd. Inorganic pigments: Cobalt aluminum blue and chrome green can be selected. This application takes cobalt aluminum blue with D50≤0.3 µm as an example. Borax: Commercially available product with CAS number 1303-96-4 is used; Laponite RD: Utilizing Laponite RD from Shanghai Davy New Materials Co., Ltd.; Phosphate esters: Polyether phosphate esters, polyethylene glycol methacrylate phosphate esters, etc. can be selected. This application takes the commercially available product TEGO DISPERS 655 from Shanghai Mengdihu Industrial Co., Ltd. as an example. Polyacrylate: Sodium polyacrylate from Dongguan Materials & Chemicals Plastics Technology Co., Ltd. Leveling agent: This application takes polyether-modified PDMS from Hubei Chengfeng Chemical Co., Ltd. as an example; Defoamer: This application takes the organosilicon defoamer from Errek (Shandong) Chemical Group Co., Ltd. as an example; Fumed silica: Fumed silica with a particle size of 10-20 nm is used. This application takes hydrophilic A20 fumed silica with a particle size of 15 nm as an example.

[0034] The present application will be further described in detail below with reference to embodiments and comparative examples. Example 1

[0035] A method for preparing tempered glass digital printing ink includes the following steps: S1. Choline chloride and glycerol are mixed in a molar ratio of 1:2, heated to 65°C and stirred until clear and transparent to obtain 42 kg of DES. Then, after cooling to 45°C, 8 kg of propylene glycol, 4 kg of deionized water and 0.4 kg of dispersant are added and stirred evenly to obtain DES base liquid. The dispersant is a mixture of phosphate ester and polyacrylate, and the mass ratio of phosphate ester and polyacrylate is 3:1. S2. 0.6 kg of Laponite RD was sieved into the DES base liquid at 7000 rpm. After shearing for 10 min, the temperature was raised to 80°C. 2 kg of polyvinyl alcohol was slowly added in batches while stirring. The mixture was stirred at a constant temperature for 40 min to obtain a mixed system. S3. Prepare a 10wt% borax aqueous solution using 0.3kg borax. After cooling the mixture to 30℃, add the 10wt% borax aqueous solution and adjust the pH to 8.9 with triethanolamine. After stirring for 15 minutes, add 0.4kg dispersant and start paddle stirring at 25℃. Add 32kg glass solvent in portions and slowly add it in portions. After the glass solvent is completely wetted, add 10kg inorganic pigment in portions and disperse at 5000rpm for 15 minutes to obtain a pre-dispersed slurry. S4. Add the pre-dispersed slurry to a horizontal bead mill with a ceramic cavity, and fill it with zirconia beads with a particle size of 0.3 nm to a volume fraction of 65%. Grind at a linear velocity of 12 m / s and stabilize the discharge temperature at ≤35℃ with cooling water until the particle size reaches the inkjet safety line to obtain bead mill slurry. Then add 0.2 kg of leveling agent and 0.05 kg of defoamer to the bead mill slurry, stir for 5 min, and adjust the pH to 8.8-9.1 with triethanolamine. Pour it into a vacuum defoaming tank for defoaming until it is visually mirror-like and there are no visible microbubbles. Then filter it through a 1.0 µm nylon / polyethersulfone terminal filter membrane at 0.2 MPa in a cylindrical filter, and nitrogen-seale and let it stand to obtain tempered glass digital printing ink.

[0036] The degree of hydrolysis of polyvinyl alcohol is 89%, and the degree of polymerization is 1800.

[0037] Example 2-3 Examples 2-3 are based on the preparation method of Example 1, but the component ratio of the tempered glass digital printing ink is adjusted as shown in Table 1.

[0038] Comparative Examples 1-4 Comparative Examples 1-4 were prepared based on the method in Example 1, but the component ratios of the tempered glass digital printing ink were adjusted as shown in Table 1.

[0039] Performance testing The tempered glass digital printing inks of Examples 1-3 and Comparative Examples 1-4 were analyzed using the following specific testing methods: 1. Viscosity The viscosity of tempered glass digital printing ink was measured using a rotational viscometer at 25°C.

[0040] 2. Suspension stability Weigh 20mL of tempered glass digital printing ink sample and put it into a 50mL transparent glass bottle with a ground glass stopper. Place the transparent glass bottle upright in an 80℃ oven for 30 days and record the time when precipitation appears in the transparent glass bottle. When precipitation appears in the bottle, gently invert the bottle 3 times and observe whether the precipitation can be completely and evenly dispersed.

[0041] Based on the above detection method, the test results of Examples 1-3 and Comparative Examples 1-4 were obtained, as shown in Table 1 below.

[0042] Table 1. Composition ratios and performance tests of tempered glass digital printing inks from Examples 1-3 and Comparative Examples 1-4.

[0043] Referring to Table 1, it can be seen from the comparison of Examples 1-3 and Comparative Examples 1-3 that the addition of polyvinyl alcohol and borax can significantly improve the performance of tempered glass digital printing ink. This is because borax hydrolyzes to generate borate ions after dissolving in water, which coordinate with the hydroxyl groups on the long chain of polyvinyl alcohol to form reversible diol-boron ester bonds, constructing a weak cross-linked network, which enables the tempered glass digital printing ink to exhibit "shear thinning" behavior.

[0044] Comparing Examples 1-3 and Comparative Example 4, it can be seen that the addition of Laponite RD can also improve the performance of tempered glass digital printing ink. This may be because the "house-brand" skeleton network formed by Laponite RD can interpenetrate with the weak cross-linked network of PVA-borax, forming a more stable and robust three-dimensional structure, which significantly improves the thixotropic properties of tempered glass digital printing ink.

[0045] Examples 4-7 Examples 4-7 are based on the preparation method of Example 1, with adjustments made to the degree of hydrolysis and degree of polymerization of polyvinyl alcohol, as shown in Table 2.

[0046] The tempered glass digital printing inks of Examples 4-7 were subjected to the above performance tests, and the test results are shown in Table 2.

[0047] Table 2. Degree of hydrolysis and degree of polymerization of polyvinyl alcohol in Examples 1 and 4-7, and their performance test results.

[0048] Referring to Table 2, comparing Examples 1 and 4-7, it can be seen that the tempered glass digital printing ink exhibits the best performance when the degree of hydrolysis of polyvinyl alcohol (PVA) is 88-90% and the degree of polymerization of PVA is in the range of 1500-2000. This may be because when the hydrolysis degree of PVA is too low, the number of hydroxyl groups on the PVA molecular chain that can coordinate with borax decreases, leading to a decrease in the strength of the PVA-borax weak crosslinking network, making the solid particles in the system more prone to sedimentation. When the hydrolysis degree of PVA is too high, the number of hydroxyl groups on the PVA molecular chain is excessive, resulting in overly dense diol-boron ester crosslinking points with borax, leading to an overly rigid PVA-borax network with poor dynamic reversibility, thus weakening the "shear thinning" behavior of the tempered glass digital printing ink. When the polymerization degree of PVA is too low, the PVA molecular chain is too short, resulting in a weak and inelastic PVA-borax network that cannot effectively support the suspension of solid particles in the system. Furthermore, the network constructed by short-chain PVA is not spatially extended enough to easily connect with Laponite. The RD framework network forms an effective, interpenetrating, and mutually reinforcing three-dimensional structure, which reduces the thixotropy of tempered glass digital printing ink. When the polymerization rate of polyvinyl alcohol is too high, the viscosity of tempered glass digital printing ink will be too high, and the speed of untangling and retangling of long-chain molecules will be slow, resulting in a sluggish dynamic response of "shear thinning" and "structural recovery", which is not conducive to high-speed printing or spraying processes.

[0049] Examples 8-11 Example 8 is based on the preparation method of Example 1, but the molar ratio of polyvinyl alcohol to boron atoms in borax is adjusted to 10:1, while the other conditions remain unchanged.

[0050] Example 9 is based on the preparation method of Example 1, except that the molar ratio of polyvinyl alcohol to boron atoms in borax is adjusted to 14:1, while the other conditions remain unchanged.

[0051] Example 10 is based on the preparation method of Example 1, except that the molar ratio of polyvinyl alcohol to boron atoms in borax is adjusted to 5:1, while the other conditions remain unchanged.

[0052] Example 11 is based on the preparation method of Example 1, except that the molar ratio of polyvinyl alcohol to boron atoms in borax is adjusted to 18:1, while the other conditions remain unchanged.

[0053] The tempered glass digital printing inks of Examples 8-11 were subjected to the above performance tests, and the test results are shown in Table 3.

[0054] Table 3. Molar ratio of boron atoms in polyvinyl alcohol and borax in Examples 1 and 8-11 and their performance test results.

[0055] Referring to Table 3, comparing Examples 1 and 8-11, it can be seen that when the molar ratio of polyvinyl alcohol to boron atoms in borax is in the range of (10-14):1, the resulting tempered glass digital printing ink exhibits the best performance. This may be because when polyvinyl alcohol is relatively excessive, insufficient borax leads to too few diol-boron ester crosslinking points, resulting in a sparse and weak dynamic crosslinking network between polyvinyl alcohol molecular chains. This leads to a decrease in the thixotropy of the tempered glass digital printing ink, making solid particles prone to sedimentation. Furthermore, under shear action, the network dissociates easily, but the viscosity decreases significantly, resulting in poor workability due to "shear-resistant" properties. When polyvinyl alcohol is relatively small, the amount of borax added is relatively excessive, leading to overly dense crosslinking points, rigid orientation of the dynamic crosslinking network, and poor dynamic reversibility, thus weakening the "shear-thinning" behavior of the tempered glass digital printing ink.

[0056] Examples 12-15 Example 12 is based on the preparation method of Example 1, but the molar ratio of glycerol to propylene glycol is adjusted to 2:1, while the other conditions remain unchanged.

[0057] Example 13 is based on the preparation method of Example 1, but the molar ratio of glycerol to propylene glycol is adjusted to 4:1, while the other conditions remain unchanged.

[0058] Example 14 is based on the preparation method of Example 1, but the molar ratio of glycerol to propylene glycol is adjusted to 1:1, while the other conditions remain unchanged.

[0059] Example 15 is based on the preparation method of Example 1, but the molar ratio of glycerol to propylene glycol is adjusted to 6:1, while the other conditions remain unchanged.

[0060] The tempered glass digital printing inks of Examples 12-15 were subjected to the above performance tests, and the test results are shown in Table 4.

[0061] Table 4 Performance test results for Examples 1 and 12-15

[0062] Referring to Table 4, a comparison of Examples 1 and 12-15 shows that the tempered glass digital printing ink exhibits the best performance when the molar ratio of glycerol to propylene glycol is in the range of (2-4):1. This may be because when the amount of glycerol added is relatively excessive, the viscosity of DES becomes too high, the hydrogen bond network becomes too dense, interfering with the reversibility of the PVA-borax dynamic coordination network and weakening the response sensitivity of "shear thinning." When the amount of glycerol added is relatively insufficient, the amount of propylene glycol added is excessive. Due to the weak hydrogen bonding ability of propylene glycol, excessive amounts will dilute the strong hydrogen bond environment of DES and weaken its secondary hydrogen bond interactions with PVA and Laponite RD, leading to a loosening of the "through-network" structure. The ink's ability to suspend solid particles decreases when stationary, making it prone to sedimentation.

[0063] Example 16 Example 16 is based on the preparation method of Example 1, but 0.2 kg of fumed silica is added to S3. The specific steps of S3 are as follows: add the prescribed amount of borax to the mixed system, adjust the pH to 8.9, let it stand and stir, and then add the prescribed amount of fumed silica, dispersant, glass solvent and inorganic pigment in sequence. After dispersing evenly, a pre-dispersed slurry is obtained. The particle size of the fumed silica is 15 nm, and the other conditions remain unchanged.

[0064] Examples 17-20 Examples 17-20 are based on the preparation method of Example 16, but the amount of fumed silica added is adjusted, as shown in Table 5.

[0065] The tempered glass digital printing inks of Examples 16-20 were subjected to the above performance tests, and the test results are shown in Table 5.

[0066] Table 5. The amount of fumed silica added and its performance test results in Examples 1 and 16-20.

[0067] Referring to Table 5, a comparison of Examples 1 and 16-20 shows that the addition of fumed silica significantly improves the performance of tempered glass digital printing ink. This is likely because the surface of fumed silica is rich in silanol groups, which can form a dense hydrogen bond network with hydroxyl and chloride ions in DES, the remaining hydroxyl groups on the polyvinyl alcohol chain, and the -Mg-OH groups and negatively charged sites on the surface of Laponite RD sheets. When fumed silica is distributed at the intersection of the PVA-borax network and the Laponite RD framework network, its strong multi-point hydrogen bonding ability can anchor the originally loose intersections together, forming a reinforced node. When stationary, fumed silica can act as a "structural reinforcing agent," providing stronger support and a more defined solid-fluid transition threshold by reinforcing network nodes, thus improving the anti-settling effect. During shearing, fumed silica can act as a "sacrificial bonding point," and its weak interaction characteristics allow it to quickly "give way" when flow is required, thereby achieving a "shear-thinning" effect.

[0068] Comparing Examples 16 and 17-20, it can be seen that the tempered glass digital printing ink obtained when the amount of fumed silica added is between 0.1-0.4 kg has the best performance. This may be because when the amount of fumed silica added is too small, the PVA-borax network and Laponite... The intersections of the RD framework network were not effectively riveted and reinforced, resulting in limited improvement in the structural strength of the three-dimensional network. Consequently, when the tempered glass digital printing ink is left to stand for a long time, the supporting force of the solid particles in the system mainly comes from the original network, which reduces the anti-settling effect. Furthermore, after shearing stops, the recovery of the tempered glass digital printing ink structure relies more on the slow recombination of PVA-borax dynamic bonds and the rearrangement of Laponite layers, resulting in an unsatisfactory recovery speed. When too much fumed silica is added, the excess fumed silica will form its own dense hydrogen bond network. This hydrogen bond network will adsorb DES, polyvinyl alcohol, and Laponite, restricting the reversible breaking and recombination of PVA-borax dynamic covalent bonds, making it difficult for the viscosity of the tempered glass digital printing ink to decrease under high shear.

[0069] Examples 21-22 Examples 21-22 are based on the preparation method of Example 1, but the components of the dispersant are adjusted as shown in Table 6.

[0070] The tempered glass digital printing inks of Examples 21-22 were subjected to the above performance tests, and the test results are shown in Table 6.

[0071] Table 6. Dispersant components and their performance test results in Examples 1 and 21-22

[0072] Referring to Table 6, a comparison of Examples 1 and 21-22 shows that the tempered glass digital printing ink obtained in Example 1 performs significantly better than the tempered glass digital printing inks of Examples 21-22. This is likely because the phosphate ester and polyacrylate are compounded into a dispersant. The phosphate ester can be rapidly adsorbed onto the surface of solid particles such as glass solvent and inorganic pigments in the DES medium, achieving rapid wetting and initial dispersion. The adsorption rate of polyacrylate is relatively slow, but its long chains can form a thick protective layer, providing extremely strong long-term steric hindrance. Furthermore, the phosphate ester can provide a first strong anchoring point through strong chemisorption, while the polyacrylate provides a second anchoring point through adsorption via multiple carboxyl groups, making the dispersant adhere more firmly to the surface of the solid particles.

[0073] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A tempered glass digital printing ink, characterized in that, It comprises the following components in parts by weight: 24-40 parts glass solvent, 8-12 parts inorganic pigment, 40-48 parts DES, 5-10 parts propylene glycol, 2-6 parts deionized water, 1-4 parts polyvinyl alcohol, 0.1-0.5 parts borax, 0.3-1 part Laponite RD, 0.5-1 part dispersant, 0.1-0.3 parts leveling agent, and 0.01-0.08 parts defoamer.

2. The tempered glass digital printing ink according to claim 1, characterized in that, The degree of hydrolysis of the polyvinyl alcohol is 88-90%, and the degree of polymerization of the polyvinyl alcohol is 1500-2000.

3. The tempered glass digital printing ink according to claim 1, characterized in that, The molar ratio of polyvinyl alcohol to boron atoms in borax is (10-14):

1.

4. The tempered glass digital printing ink according to claim 1, characterized in that, The hydrogen bond donor of the DES is glycerol, and the hydrogen bond acceptor is choline chloride.

5. The tempered glass digital printing ink according to claim 4, characterized in that, The molar ratio of glycerol to propylene glycol is (1-2):

1.

6. The tempered glass digital printing ink according to claim 1, characterized in that, It also contains fumed silica with a particle size of 10-20 nm.

7. The tempered glass digital printing ink according to claim 6, characterized in that, The amount of fumed silica added is 0.1-0.4 parts.

8. The tempered glass digital printing ink according to claim 1, characterized in that, The dispersant is at least one of phosphate ester and polyacrylate.

9. A method for preparing a tempered glass digital printing ink according to claims 1-8, comprising the following steps: S1. Add the prescribed amounts of propylene glycol and deionized water to DES and mix thoroughly to obtain DES base solution; S2. Add the prescribed amount of Laponite RD to the DES base liquid, shear and disperse it, then add the prescribed amount of polyvinyl alcohol under stirring, and stir to obtain a mixed system. S3. Add the prescribed amount of borax to the mixing system, adjust the pH to 8.6-9.2, let it stand and stir, then add the prescribed amount of dispersant, glass solvent and inorganic pigment in sequence, and disperse evenly to obtain a pre-dispersed slurry; S4. The pre-dispersed slurry is bead milled to obtain bead milled slurry. The formulated amount of leveling agent and defoamer is then added to the bead milled slurry. After stirring evenly, vacuum degassing and filtration are performed, and the mixture is allowed to stand to obtain tempered glass digital printing ink.

10. The method for preparing tempered glass digital printing ink according to claim 9, characterized in that, In S3, the prescribed amount of borax is added to the mixing system, the pH is adjusted to 8.6-9.2, and after standing and stirring, the prescribed amounts of fumed silica, dispersant, glass solvent and inorganic pigment are added in sequence. After being dispersed evenly, a pre-dispersed slurry is obtained.

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