High-stability uv ink and preparation method thereof

Abstract

The application discloses a kind of high stability UV ink and preparation method thereof, it is related to ink technical field, ink is by following component by weight parts, acrylate oligomer 40-60 parts, active dilution monomer 20-30 parts, photoinitiator 5-10 parts, pigment 10-15 parts, dispersing agent 1-3 parts, stimulus response type viscosity regulator 3-8 parts and auxiliary agent 0.5-2 parts;Stimulus response type viscosity regulator gives ink dynamic viscosity regulation ability, ensure printing viscosity stability under different environments;Acrylate oligomer complex system etc. optimization makes that dot reproduction precision is significantly improved, pattern definition and detail restoration ability are greatly enhanced;Compound photoinitiation system cooperates specific illumination process, and curing efficiency is greatly improved, and production efficiency is significantly improved.

Description

Technical Field

[0001] This invention relates to the field of ink technology, specifically to a highly stable UV ink and its preparation method. Background Technology

[0002] UV inks, as an environmentally friendly type of ink, are widely used in printing and packaging due to their advantages such as fast drying speed, high gloss, and good abrasion resistance. However, existing UV inks still have some problems during use, such as poor viscosity stability. The ink viscosity is prone to change under different temperatures and shear rates, leading to unstable printing quality. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a highly stable UV ink. By optimizing the selection and reasonable proportioning of each component of the ink, and by employing a special preparation process, the aforementioned problems of existing UV inks are solved.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a highly stable UV ink, which, by weight, is composed of the following components: 40-60 parts of acrylate oligomer, 20-30 parts of reactive diluent monomer, 5-10 parts of photoinitiator, 10-15 parts of pigment, 1-3 parts of dispersant, 3-8 parts of stimulus-responsive viscosity modifier, and 0.5-2 parts of additives.

[0005] Preferably, the method for preparing the stimulus-responsive viscosity modifier includes the following steps:

[0006] Step (a): Dissolve 10-15 parts of dimethylaminoethyl methacrylate (temperature-sensitive unit), 5-8 parts of perfluorooctyl ethyl acrylate (shear-sensitive unit), and 2-4 parts of photoresponsive spirocyclic compound (photoresponsive unit) in supercritical CO2;

[0007] Step (b): React at 55-65 MPa and 45-55 °C for 1.5-2.5 hours;

[0008] Step (c): Decelerate to atmospheric pressure at a rate of 5 MPa / 10 min to obtain microcapsules with a particle size of 0.5-2 μm.

[0009] Preferably, the preparation steps of the photoresponsive spirocyclic compound are as follows:

[0010] Step (d): 2-Nitrobenzaldehyde and morpholinopropylamine were refluxed in ethanol for 3 hours to generate a Schiff base intermediate.

[0011] Step (e) Under argon protection, the intermediate is reacted with 2-hydroxy-1-naphthal at 120°C for 6 hours;

[0012] Step (f) Purification by column chromatography with eluent: ethyl acetate and petroleum ether in a volume ratio of 1:5, yielding purple crystals.

[0013] Preferably, the molar ratio of dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and the photoresponsive spirocyclic compound is 1.5-2.0:1:0.5-0.8.

[0014] Preferably, the acrylate oligomer is a mixture of polyurethane acrylate and epoxy acrylate in a mass ratio of 2.5-3.5:1.

[0015] Preferably, the reactive diluent monomer comprises trimethylolpropane triacrylate (TMPTA) and bisphenol A diacrylate ethoxylate (EO-BPADA) in a mass ratio of 2-3:1.

[0016] Preferably, the additive, by weight, comprises the following components: 0.3-1 parts of silicone leveling agent, 0.1-0.5 parts of hindered amine light stabilizer, and 0.1-0.5 parts of fluorinated surfactant.

[0017] Preferably, the dispersant is a mixture of polyester-modified polydimethylsiloxane and BYK-163 in a mass ratio of 2:1, and the photoinitiator comprises acylphosphine oxide and α-hydroxy ketone in a mass ratio of 3:1.

[0018] A method for preparing UV ink includes the following steps:

[0019] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40-50% of the total amount of active diluent monomer, and sonicate it for 20-40 minutes at a power of 300-500W and a frequency of 40kHz.

[0020] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3-0.5mm) at a grinding chamber temperature of 20℃ for 2-4 hours until the particle size D50≤2μm;

[0021] Step (3) Under nitrogen protection, add the acrylate oligomer and the remaining monomers in three stages at 25-45℃, with an interval of 15-25 minutes between each stage;

[0022] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1-1.5 hours under blue light irradiation at a wavelength of 405nm and a light intensity of 10-15mW / cm².

[0023] Preferably, the three-stage gradient addition in step (3) is specifically as follows:

[0024] First stage: Add 30-40% acrylate oligomer at 25℃, stirring at 300-400 rpm;

[0025] Second stage: Add 30-40% acrylate oligomer at 35℃, stirring at 500-600 rpm;

[0026] Third stage: Add the remaining components at 45℃, stirring at 800-1000 rpm.

[0027] Compared with the prior art, the present invention provides a highly stable UV ink and its preparation method, which has the following beneficial effects: by using a stimulus-responsive viscosity modifier pre-dispersion process, combined with its core-shell structure design, the viscosity change rate of the ink is controlled at 5.2% or less, ensuring rheological stability under different environments and printing conditions.

[0028] The innovative pigment ball milling and dispersion technology, combined with the compound dispersant, improves the dot reproduction rate to over 92%, which is about 10% higher than commercially available inks. It effectively eliminates dot blurring and distortion problems, meeting the high-precision requirements of high-end printing.

[0029] The combination of gradient feeding and blue light excitation technology increases the curing speed to over 12m / min, which is more than 20% faster than traditional processes, significantly shortening the production cycle and improving printing efficiency.

[0030] Excellent abrasion resistance: Through optimized molecular mixing and cross-linking processes, the friction fastness reaches level 4 or above, which is 1-2 levels higher than traditional inks, greatly enhancing the durability of printed materials and reducing wear and fading. Attached Figure Description

[0031] Figure 1 This is a diagram of the product prepared according to Embodiment 1 of the present invention. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] I. Viscosity Stability Test

[0034] Reference Standard: Currently, there is no unified national standard specifically for the viscosity stability of UV inks at specific temperatures and times. This test mainly refers to the general testing methods for ink stability and common practices in the industry. For assessing the stability of inks under different temperature environments, the physical properties of the ink are often observed after a certain period of temperature treatment, such as whether gelation or coarsening occurs, and the viscosity changes.

[0035] Test steps:

[0036] Prepare several clean, dry containers with sealed lids, accurately weigh an appropriate amount of the UV ink sample to be tested, and record the initial mass.

[0037] Place the containers containing the ink samples in a constant-temperature oven at 40°C, with the oven temperature fluctuating within ±1°C. During placement, ensure the sample containers are stable and do not interfere with each other.

[0038] After placing the ink sample in the oven for 30 days, remove the container and allow it to return to room temperature (25°C). This process can be done by placing the container in a temperature-stable indoor environment to cool naturally for at least 2 hours.

[0039] Viscosity measurements were performed using a calibrated rotational viscometer. Before measurement, a suitable rotor and rotation speed combination was selected based on the expected viscosity range of the ink sample to ensure the measurement results were within the effective measurement range of the viscometer. The rotor of the viscometer was slowly and vertically immersed into the ink sample until the required immersion depth was reached. The viscometer was then started, and the measurement was performed for the time specified in the instrument's operating manual. The obtained viscosity value was recorded.

[0040] The viscosity change rate is calculated using the formula: Viscosity change rate = (Viscosity after 30 days of storage - Initial viscosity) / Initial viscosity × 100%. Wherein, the initial viscosity is the viscosity value measured at room temperature before the ink sample underwent the 40℃ storage treatment.

[0041] II. Network Reproducibility Test

[0042] Reference standards: Refer to the general methods for dot reproducibility evaluation in the printing industry and relevant industry standards, such as dot quality evaluation specifications formulated by some printing associations for different printing processes and ink types. The main focus is on indicators such as the shape, size accuracy, and sharpness of dots at a specific screen ruling.

[0043] Test steps:

[0044] Create or select a standard 200 LPI printing test plate containing halftone patterns of different shapes (circles, squares, rhombuses, etc.) and different area percentages (such as 10%, 30%, 50%, 70%, 90%, etc.). The material, surface roughness, and other parameters of the test plate should meet the general standards of the printing industry to ensure that it can accurately reflect the halftone transfer performance of ink in actual printing.

[0045] Install the UV ink to be tested onto industry-standard printing equipment and adjust all parameters of the equipment to standard settings, including but not limited to printing pressure, ink supply, and printing speed. The printing pressure needs to be adjusted according to the printing plate and substrate type used to ensure uniform pressure and good ink transfer. The ink supply should be adjusted to ensure that the dots are clearly and completely printed on the substrate without ink buildup or missing dots. The printing speed should be set to the recommended speed range for this type of UV ink and substrate during normal production.

[0046] Use the selected substrate (usually industry-standard printing paper or film material) on the printing equipment, printing at least 5 sheets to ensure the reliability of the test results. During the printing process, closely observe the operating status of the printing equipment to ensure that the printing process is stable and free from abnormal fluctuations.

[0047] After printing, allow the ink to fully dry and cure (for UV inks, curing can be performed using standard UV curing equipment to ensure consistent curing conditions). Use a calibrated magnifying glass with a certain magnification (e.g., 10-20x) or a professional dot meter to observe and measure the dots on the printed material. For dot sharpness, mainly observe whether the dot edges are clear and sharp, and whether there is any blurring or ghosting. For dot accuracy, measure the actual area size of dots at different area percentages and compare it with the theoretical value to calculate the percentage of dot enlargement or shrinkage.

[0048] The dot reproduction rate is expressed as a percentage, and the formula is: Dot Reproduction Rate = (Total area of ​​actual accurately reproduced dots / Total area of ​​theoretical dots) × 100%. The total area of ​​actual accurately reproduced dots is obtained by summing the areas of dots whose shape and size meet the standard requirements among dots of different area percentages; the total area of ​​theoretical dots is calculated based on the area of ​​the dot pattern designed on the test version.

[0049] III. Curing speed test

[0050] Reference standards: Refer to industry testing standards related to UV ink curing speed, such as test specifications for the curing performance of UV inks on standard printing equipment developed by some ink production associations, and guidance documents on UV curing system performance evaluation provided by printing equipment manufacturers.

[0051] Test steps:

[0052] The UV ink to be tested is installed on a standard printing machine equipped with a standard UV curing lamp. It is ensured that the model, power, wavelength, and other parameters of the UV curing lamp meet industry standards, and that the lamp's usage time is within the specified validity period to guarantee stable luminescent performance. Simultaneously, the printing machine's transmission system and ink delivery system are inspected and tested to ensure normal operation.

[0053] Choose a substrate that meets industry standards, such as common printing paper or plastic film, and attach it to the paper or film feeding device of the printing equipment.

[0054] Adjust the printing speed of the printing equipment, starting with a lower speed, such as 5 m / min. During the printing process, observe the curing state of the ink on the printed material to determine if curing is complete. The following method can be used to judge: gently wipe the ink-printed area of ​​the printed material with a clean cotton ball or soft cloth. If the cotton ball or cloth does not pick up ink, and the ink surface is dry, smooth, and non-sticky, then the ink is considered to be completely cured; if ink is picked up, it indicates that the ink is not completely cured.

[0055] Gradually increase the printing speed by 1 m / min each time, repeating the printing and inspection process until the highest printing speed at which the ink can just fully cure is found. This speed is the curing speed of the UV ink, expressed in m / min. During the test, keep other printing parameters (such as ink supply, printing pressure, UV curing lamp power, and irradiation time) constant.

[0056] IV. Friction fastness test

[0057] Reference Standards: Primarily referenced are the ISO 2409 cross-cut adhesion test standard and relevant industry standards for testing the rubbing fastness of printing inks. The ISO 2409 cross-cut adhesion test is commonly used to evaluate the adhesion of coatings or inks to a substrate. By simulating a certain degree of friction, the ink's color fading and wear are observed, thus indirectly reflecting the ink's rubbing fastness.

[0058] Test steps:

[0059] The UV ink to be tested is printed on a substrate that meets industry standards to form a uniform and smooth ink film. After printing, the printed material is placed under standard environmental conditions (temperature 23℃, relative humidity 50±5%) for drying and curing. The curing time is determined according to the characteristics of the UV ink and standard requirements to ensure that the ink is completely cured.

[0060] Using a single-edged crisscross cutter conforming to ISO 2409 standards, select an appropriate crisscross spacing based on the thickness of the ink film (generally 1mm for thinner ink films and 2mm or 3mm for thicker ones). Apply stable pressure and maintain the appropriate spacing to cut the ink film at a uniform speed, ensuring the blade penetrates the substrate surface to create a series of parallel crisscrosses. Then, make another set of parallel crisscrosses at a 90° angle, intersecting the previous crisscrosses to form a grid pattern.

[0061] Gently sweep the surface of the gridded area with a soft brush to remove ink debris generated during cutting.

[0062] Select a transparent pressure-sensitive adhesive tape of suitable width (e.g., 15mm or 25mm) that meets standard requirements, such as 3M 600 tape. Smoothly attach one end of the tape to the center of the marked area. Apply even pressure to the tape using your fingers or a dedicated pressure roller to ensure full contact and firm adhesion between the tape and the ink film. After application, hold for at least 20 seconds to allow good adhesion to form between the tape and the ink film.

[0063] Grasp one end of the tape and tear it quickly at an angle of approximately 60° within 0.5-1.0 seconds. Maintain a smooth and continuous motion while tearing to avoid wobbling or uneven stretching of the tape.

[0064] Observe the color fading and wear of the ink film within the marked area, and evaluate it according to the rubbing fastness grade specified in the relevant standards. The rubbing fastness grade is generally divided into 0-5 levels, where level 0 indicates that the ink film has not peeled off at all, with the best adhesion and the highest rubbing fastness; level 5 indicates that the ink film has almost completely peeled off, with the worst adhesion and the lowest rubbing fastness. For specific evaluation, refer to the pictures or text descriptions provided in the standard, compare the tested marked area, and determine its corresponding rubbing fastness grade.

[0065] Introduction to related instruments:

[0066] Constant temperature drying oven, model: DHG-9070A, purpose description: used to perform constant temperature treatment of UV ink samples at 40℃ for 30 days, providing a stable high temperature environment for testing, with temperature fluctuation range controllable within ±1℃, ensuring consistency of test conditions.

[0067] Rotational viscometer, model: Brookfield DV2T, application description: By selecting an appropriate rotor and rotational speed combination, the viscosity of ink samples before and after processing is measured. During measurement, the rotor is vertically immersed in the ink sample. According to the instrument's principle, the viscous resistance experienced by the rotor is converted into a viscosity value, enabling accurate measurement of inks with different viscosity ranges and ensuring that the measurement results are within the valid range.

[0068] Standard printing equipment, model: Heidelberg Speedmaster CX102, intended for printing UV inks to be tested onto substrates. This equipment allows for precise adjustment of parameters such as printing pressure, ink supply, and printing speed to ensure printing under standard conditions. This results in printed dot patterns that accurately reflect the dot transfer performance of the ink, with high repeatability, ensuring reliable test results.

[0069] UV curing equipment, common model: PhoseonFireEdge, application description: to cure printed inks, providing stable and industry-standard UV curing conditions, such as specific wavelengths, light intensities and irradiation times, to ensure that the inks are completely dried and cured under the same conditions, avoiding the impact of insufficient curing on dot reproducibility test results.

[0070] Magnifying glasses or dot matrix detectors, common models include: Mitutoyo BHM-150 (magnifying glass), X-RiteeXact2 (dot matrix detector). Their uses include observing and measuring halftone dots on printed materials. Magnifying glasses, with magnification of 10-20x, allow for direct observation of dot edge sharpness and the presence of ghosting. Dot matrix detectors accurately measure the actual area of ​​dots at different percentages, calculating the percentage of dot enlargement or reduction by comparing it to theoretical values, thus accurately assessing dot reproduction rate.

[0071] Standard printing equipment, model: Heidelberg Speedmaster CX102, intended for mounting and printing UV inks to be tested. By gradually adjusting the printing speed, the curing process of the ink at different speeds is tested. Stable operation and precise parameter control of the equipment help to accurately determine the maximum printing speed at which the ink is just fully cured, i.e., the curing speed.

[0072] UV curing lamp, model: Hamamatsu LC8 (for use with printing equipment), application description: As a core component of the UV curing system, it provides ultraviolet light of specific wavelength and power for ink curing. Its model, power, wavelength and other parameters conform to industry-standard specifications, and it is within its validity period, ensuring stable luminescent performance and guaranteeing that the ink receives sufficient and consistent curing energy during the printing process.

[0073] Cotton balls or soft cloths are acceptable, regardless of their specific type, as long as they meet the standards of cleanliness and softness. Instructions for use: During the printing process, gently wipe the ink-printed areas of the printed material with cotton balls or soft cloths. Based on whether ink gets on the surface and the condition of the ink surface (dry, smooth, non-sticky), you can determine whether the ink has completely cured. It is a simple and effective tool for checking the curing status.

[0074] Single-edged crisscross cutter, model: QFH, application description: Select the appropriate crisscross spacing (1mm, 2mm, or 3mm) according to the ink film thickness to perform a crisscross operation on the ink film of printed materials. By cutting at a uniform speed, an intersecting grid is formed to simulate a certain degree of friction, providing a test basis for subsequent evaluation of the adhesion and friction resistance of the ink film.

[0075] Soft-bristled brush, no specific model required. Just make sure the bristles are soft and clean. Instructions for use: After marking the grid, use it to gently sweep the surface of the marked area to remove ink debris generated during cutting, so as to avoid the debris interfering with subsequent testing steps (such as applying tape) and result evaluation.

[0076] Transparent pressure-sensitive tape, model: 3M 600. Instructions for use: Apply the tape smoothly to the marked area, applying uniform pressure to ensure full contact and firm adhesion with the ink film. Then quickly tear the tape to simulate friction in actual use. Assess the friction resistance level based on the color fading and wear of the ink film.

[0077] Pressure roller, model: Rhopoint 5kg pressure roller, application: When applying tape, the pressure roller applies uniform pressure to the tape to ensure good adhesion between the tape and the ink film, making the testing process more standardized and the results more reliable.

[0078] Example 1

[0079] A highly stable UV ink, by weight, comprises 40 parts of acrylate oligomer (polyurethane acrylate to epoxy acrylate mass ratio 2.5:1), 20 parts of reactive diluent monomer (trimethylolpropane triacrylate to bisphenol A diacrylate mass ratio 2:1), 5 parts of photoinitiator (acylphosphine oxide to α-hydroxy ketone mass ratio 3:1), 10 parts of pigment, 1 part of dispersant (polyester modified polydimethylsiloxane to BYK-163 mass ratio 2:1), 3 parts of stimulus-responsive viscosity modifier (dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and photoresponsive spirocyclic compound molar ratio 1.5:1:0.5), and 0.5 parts of additives (0.3 parts of silicone leveling agent, 0.1 parts of hindered amine light stabilizer, and 0.1 parts of fluorinated surfactant).

[0080] UV ink was prepared according to the above preparation method:

[0081] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0082] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0083] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with a 15-minute interval between each stage. First stage: 30% acrylate oligomer is added at 25℃ with a stirring speed of 300 rpm; Second stage: 30% acrylate oligomer is added at 35℃ with a stirring speed of 500 rpm; Third stage: the remaining components are added at 45℃ with a stirring speed of 800 rpm.

[0084] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0085] Example 2

[0086] A highly stable UV ink, by weight, comprises 50 parts of acrylate oligomer (polyurethane acrylate to epoxy acrylate in a mass ratio of 3:1), 20 parts of reactive diluent monomer (trimethylolpropane triacrylate to bisphenol A diacrylate in a mass ratio of 2:1), 5 parts of photoinitiator (acylphosphine oxide to α-hydroxy ketone in a mass ratio of 3:1), 10 parts of pigment, 1 part of dispersant (polyester-modified polydimethylsiloxane to BYK-163 in a mass ratio of 2:1), 3 parts of stimulus-responsive viscosity modifier (dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and photoresponsive spirocyclic compound in a molar ratio of 1.5:1:0.5), and 0.5 parts of additives (0.3 parts of silicone leveling agent, 0.1 parts of hindered amine light stabilizer, and 0.1 parts of fluorinated surfactant).

[0087] UV ink was prepared according to the above preparation method:

[0088] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0089] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0090] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with a 15-minute interval between each stage. First stage: 30% acrylate oligomer is added at 25℃ with a stirring speed of 300 rpm; Second stage: 30% acrylate oligomer is added at 35℃ with a stirring speed of 500 rpm; Third stage: the remaining components are added at 45℃ with a stirring speed of 800 rpm.

[0091] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0092] Example 3

[0093] A highly stable UV ink, by weight, comprises 40 parts of acrylate oligomer (polyurethane acrylate to epoxy acrylate mass ratio 2.5:1), 25 parts of reactive diluent monomer (trimethylolpropane triacrylate to bisphenol A diacrylate mass ratio 2.5:1), 5 parts of photoinitiator (acylphosphine oxide to α-hydroxy ketone mass ratio 3:1), 10 parts of pigment, 1 part of dispersant (polyester modified polydimethylsiloxane to BYK-163 mass ratio 2:1), 3 parts of stimulus-responsive viscosity modifier (dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and photoresponsive spirocyclic compound molar ratio 1.5:1:0.5), and 0.5 parts of additives (0.3 parts of silicone leveling agent, 0.1 parts of hindered amine light stabilizer, and 0.1 parts of fluorinated surfactant).

[0094] UV ink was prepared according to the above preparation method:

[0095] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0096] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0097] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with a 15-minute interval between each stage. First stage: 30% acrylate oligomer is added at 25℃ with a stirring speed of 300 rpm; Second stage: 30% acrylate oligomer is added at 35℃ with a stirring speed of 500 rpm; Third stage: the remaining components are added at 45℃ with a stirring speed of 800 rpm.

[0098] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0099] Example 4

[0100] A highly stable UV ink, by weight, comprises 40 parts of acrylate oligomer (polyurethane acrylate to epoxy acrylate mass ratio 2.5:1), 20 parts of reactive diluent monomer (trimethylolpropane triacrylate to bisphenol A diacrylate mass ratio 2:1), 8 parts of photoinitiator (acylphosphine oxide to α-hydroxy ketone mass ratio 3:1), 10 parts of pigment, 1 part of dispersant (polyester modified polydimethylsiloxane to BYK-163 mass ratio 2:1), 3 parts of stimulus-responsive viscosity modifier (dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate to photoresponsive spirocyclic compound molar ratio 1.5:1:0.5), and 0.5 parts of additives (0.3 parts of silicone leveling agent, 0.1 parts of hindered amine light stabilizer, and 0.1 parts of fluorinated surfactant).

[0101] UV ink was prepared according to the above preparation method:

[0102] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0103] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0104] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with a 15-minute interval between each stage. First stage: 30% acrylate oligomer is added at 25℃ with a stirring speed of 300 rpm; Second stage: 30% acrylate oligomer is added at 35℃ with a stirring speed of 500 rpm; Third stage: the remaining components are added at 45℃ with a stirring speed of 800 rpm.

[0105] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0106] Example 5

[0107] A highly stable UV ink, by weight, comprises 40 parts of acrylate oligomer (polyurethane acrylate to epoxy acrylate mass ratio 2.5:1), 20 parts of reactive diluent monomer (trimethylolpropane triacrylate to bisphenol A diacrylate mass ratio 2:1), 5 parts of photoinitiator (acylphosphine oxide to α-hydroxy ketone mass ratio 3:1), 10 parts of pigment, 1 part of dispersant (polyester modified polydimethylsiloxane to BYK-163 mass ratio 2:1), 6 parts of stimulus-responsive viscosity modifier (dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate to photoresponsive spirocyclic compound molar ratio 1.8:1:0.7), and 0.5 parts of additives (0.3 parts of silicone leveling agent, 0.1 parts of hindered amine light stabilizer, and 0.1 parts of fluorinated surfactant).

[0108] UV ink was prepared according to the above preparation method:

[0109] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0110] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0111] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with a 15-minute interval between each stage. First stage: 30% acrylate oligomer is added at 25℃ with a stirring speed of 300 rpm; Second stage: 30% acrylate oligomer is added at 35℃ with a stirring speed of 500 rpm; Third stage: the remaining components are added at 45℃ with a stirring speed of 800 rpm.

[0112] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0113] Example 6

[0114] A highly stable UV ink, by weight, comprises 40 parts of acrylate oligomer (polyurethane acrylate to epoxy acrylate mass ratio 2.5:1), 20 parts of reactive diluent monomer (trimethylolpropane triacrylate to bisphenol A diacrylate mass ratio 2:1), 5 parts of photoinitiator (acylphosphine oxide to α-hydroxy ketone mass ratio 3:1), 10 parts of pigment, 1 part of dispersant (polyester modified polydimethylsiloxane to BYK-163 mass ratio 2:1), 3 parts of stimulus-responsive viscosity modifier (dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and photoresponsive spirocyclic compound molar ratio 1.5:1:0.5), and 1.5 parts of additives (0.7 parts of silicone leveling agent, 0.3 parts of hindered amine light stabilizer, and 0.5 parts of fluorinated surfactant).

[0115] UV ink was prepared according to the above preparation method:

[0116] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0117] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0118] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with a 15-minute interval between each stage. First stage: 30% acrylate oligomer is added at 25℃ with a stirring speed of 300 rpm; Second stage: 30% acrylate oligomer is added at 35℃ with a stirring speed of 500 rpm; Third stage: the remaining components are added at 45℃ with a stirring speed of 800 rpm.

[0119] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0120] Comparative Example 1

[0121] A UV ink, by weight, comprises 40 parts of acrylate oligomer (polyurethane acrylate to epoxy acrylate mass ratio 2.5:1), 20 parts of reactive diluent monomer (trimethylolpropane triacrylate to bisphenol A diacrylate mass ratio 2:1), 5 parts of photoinitiator (acylphosphine oxide to α-hydroxy ketone mass ratio 3:1), 10 parts of pigment, 1 part of dispersant (polyester modified polydimethylsiloxane to BYK-163 mass ratio 2:1), and 0.5 parts of additives (0.3 parts of silicone leveling agent, 0.1 parts of hindered amine light stabilizer, and 0.1 parts of fluorinated surfactant).

[0122] UV ink was prepared according to the above preparation method:

[0123] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0124] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0125] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with a 15-minute interval between each stage. First stage: 30% acrylate oligomer is added at 25℃ with a stirring speed of 300 rpm; Second stage: 30% acrylate oligomer is added at 35℃ with a stirring speed of 500 rpm; Third stage: the remaining components are added at 45℃ with a stirring speed of 800 rpm.

[0126] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0127] Comparative Example 2

[0128] A UV ink, by weight, comprises 40 parts of acrylate oligomer (polyurethane acrylate), 20 parts of reactive diluent monomer (trimethylolpropane triacrylate and bisphenol A diacrylate in a mass ratio of 2:1), 5 parts of photoinitiator (acylphosphine oxide and α-hydroxy ketone in a mass ratio of 3:1), 10 parts of pigment, 1 part of dispersant (polyester-modified polydimethylsiloxane and BYK-163 in a mass ratio of 2:1), 3 parts of stimulus-responsive viscosity modifier (dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and photoresponsive spirocyclic compound in a molar ratio of 1.5:1:0.5), and 0.5 parts of additives (0.3 parts of silicone leveling agent, 0.1 parts of hindered amine light stabilizer, and 0.1 parts of fluorinated surfactant).

[0129] UV ink was prepared according to the above preparation method:

[0130] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0131] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0132] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with a 15-minute interval between each stage. First stage: 30% acrylate oligomer is added at 25℃ with a stirring speed of 300 rpm; Second stage: 30% acrylate oligomer is added at 35℃ with a stirring speed of 500 rpm; Third stage: the remaining components are added at 45℃ with a stirring speed of 800 rpm.

[0133] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0134] Comparative Example 3

[0135] A UV ink, by weight, comprises 40 parts of acrylate oligomer (polyurethane acrylate to epoxy acrylate mass ratio 2.5:1), 20 parts of reactive diluent monomer (trimethylolpropane triacrylate), 5 parts of photoinitiator (acylphosphine oxide to α-hydroxy ketone mass ratio 3:1), 10 parts of pigment, 1 part of dispersant (polyester modified polydimethylsiloxane to BYK-163 mass ratio 2:1), 3 parts of stimulus-responsive viscosity modifier (dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and photoresponsive spirocyclic compound molar ratio 1.5:1:0.5), and 0.5 parts of additives (0.3 parts of silicone leveling agent, 0.1 parts of hindered amine light stabilizer, and 0.1 parts of fluorinated surfactant).

[0136] UV ink was prepared according to the above preparation method:

[0137] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0138] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0139] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with a 15-minute interval between each stage. First stage: 30% acrylate oligomer is added at 25℃ with a stirring speed of 300 rpm; Second stage: 30% acrylate oligomer is added at 35℃ with a stirring speed of 500 rpm; Third stage: the remaining components are added at 45℃ with a stirring speed of 800 rpm.

[0140] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0141] Comparative Example 4

[0142] A UV ink, by weight, comprises 40 parts of acrylate oligomer (polyurethane acrylate to epoxy acrylate mass ratio 2.5:1), 20 parts of reactive diluent monomer (trimethylolpropane triacrylate to bisphenol A diacrylate mass ratio 2:1), 5 parts of photoinitiator (acylphosphine oxide), 10 parts of pigment, 1 part of dispersant (polyester modified polydimethylsiloxane to BYK-163 mass ratio 2:1), 3 parts of stimulus-responsive viscosity modifier (dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and photoresponsive spirocyclic compound molar ratio 1.5:1:0.5), and 0.5 parts of additives (0.3 parts of silicone leveling agent, 0.1 parts of hindered amine light stabilizer, and 0.1 parts of fluorinated surfactant).

[0143] UV ink was prepared according to the above preparation method:

[0144] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0145] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0146] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with a 15-minute interval between each stage. First stage: 30% acrylate oligomer is added at 25℃ with a stirring speed of 300 rpm; Second stage: 30% acrylate oligomer is added at 35℃ with a stirring speed of 500 rpm; Third stage: the remaining components are added at 45℃ with a stirring speed of 800 rpm.

[0147] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0148] Comparative Example 5

[0149] A UV ink, by weight, comprises 40 parts of acrylate oligomer (polyurethane acrylate to epoxy acrylate mass ratio 2.5:1), 20 parts of reactive diluent monomer (trimethylolpropane triacrylate to bisphenol A diacrylate mass ratio 2:1), 5 parts of photoinitiator (acylphosphine oxide to α-hydroxy ketone mass ratio 3:1), 10 parts of pigment, 1 part of dispersant (polyester modified polydimethylsiloxane), 3 parts of stimulus-responsive viscosity modifier (dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and photoresponsive spirocyclic compound molar ratio 1.5:1:0.5), and 0.5 parts of additives (0.3 parts of silicone leveling agent, 0.1 parts of hindered amine light stabilizer, and 0.1 parts of fluorinated surfactant).

[0150] UV ink was prepared according to the above preparation method:

[0151] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0152] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0153] Step (3) Under nitrogen protection, add the acrylate oligomer and the remaining monomers at once, at 45°C and a stirring speed of 800 rpm;

[0154] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0155] Comparative Example 6

[0156] A UV ink, by weight, comprises 40 parts of acrylate oligomer (polyurethane acrylate to epoxy acrylate mass ratio 2.5:1), 20 parts of reactive diluent monomer (trimethylolpropane triacrylate to bisphenol A diacrylate mass ratio 2:1), 5 parts of photoinitiator (acylphosphine oxide to α-hydroxy ketone mass ratio 3:1), 10 parts of pigment, 1 part of dispersant (polyester modified polydimethylsiloxane to BYK-163 mass ratio 2:1), 3 parts of stimulus-responsive viscosity modifier (dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and photoresponsive spirocyclic compound molar ratio 1.5:1:0.5), and 0.5 parts of additives (organosilicon leveling agent 0.3 parts, hindered amine light stabilizer 0.1 parts, fluorinated surfactant 0.1 parts).

[0157] UV ink was prepared according to the above preparation method:

[0158] Step (1) Pre-disperse the stimulus-responsive viscosity modifier in 40% of the total active diluent monomer and sonicate it for 20 minutes at a power of 300W and a frequency of 40kHz.

[0159] Step (2) Add pigment and dispersant, and ball mill with zirconia beads (Φ0.3mm) at a grinding chamber temperature of 20℃ for 2 hours until the particle size D50≤2μm;

[0160] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with a 15-minute interval between each stage. First stage: 30% acrylate oligomer is added at 25℃ with a stirring speed of 300 rpm; Second stage: 30% acrylate oligomer is added at 35℃ with a stirring speed of 500 rpm; Third stage: the remaining components are added at 45℃ with a stirring speed of 800 rpm.

[0161] Step (4) Add photoinitiator and additives, and stir at a constant speed for 1 hour under blue light irradiation at a wavelength of 405nm and a light intensity of 10mW / cm².

[0162] Comparative Example 7

[0163] Purchase commercially available UV inks.

[0164] Table 1 shows the composition of Comparative Example 7.

[0165]

[0166] The UV inks obtained from Examples 1, 2, 3, 4, 5, 6 and Comparative Examples 1, 2, 3, 4, 5, 6, 7 were grouped and numbered as follows: UM-BH-01, UM-BH-02, UM-BH-03, UM-BH-04, UM-BH-05, UM-BH-06, UM-BH-07, UM-BH-08, UM-BH-09, UM-BH-010, UM-BH-011, UM-BH-012, and UM-BH-013. Performance tests were conducted on the products from the Examples and Comparative Examples, specifically including viscosity stability (40℃ / 30 days), viscosity change rate, dot reproducibility (200 LPI), curing speed (m / min), and rubbing fastness (grade). Detailed test results are shown in Tables 2 and 3.

[0167] Table 2 shows the test results for viscosity stability and dot reproducibility.

[0168]

[0169] Table 3 shows the test results for curing speed and friction fastness.

[0170]

[0171] Ultrasonic treatment utilizes the cavitation effect generated by high-frequency vibration to fully disperse the regulator microcapsules in the monomer, avoid agglomeration, and ensure their uniform distribution in the ink system, laying the foundation for subsequent dynamic regulation.

[0172] In Comparative Example 1, without the addition of this regulator, the viscosity change rate after 30 days at 40°C was as high as 18.7%. However, in Examples 1 to 6, the regulator was effectively dispersed through this treatment step, and the viscosity change rate was controlled at 5.2% or less. This is because the uniformly dispersed regulator, with its core layer's temperature-sensitive unit (dimethylaminoethyl methacrylate) and light-responsive unit, and its shell layer's shear-sensitive unit (perfluorooctyl ethyl acrylate), can respond promptly to environmental changes at 25-45°C and 500-5000 s⁻¹ shear rates. Through changes in molecular conformation or interactions between groups, it achieves dynamic viscosity adjustment, ensuring the rheological stability of the ink under different printing conditions.

[0173] The appropriate grinding chamber temperature prevents some components in the ink from undergoing chemical reactions or changes in performance due to excessive temperature. The grinding action of the zirconia beads enables the pigment to achieve finer dispersion in the synergy of the dispersant (polyester-modified polydimethylsiloxane and BYK-163 compounded at a mass ratio of 2:1).

[0174] In the dot reproducibility test, Comparative Examples 1 to 6 all had dot reproducibility rates below 90% due to improper dispersion processes or dispersant selection, with Comparative Example 7 showing 84% for commercially available ink. However, after this treatment step, Examples 1 to 6 exhibited uniform pigment dispersion, improved ink flow and leveling, and dot reproducibility rates of 92% and above, with a maximum of 95%. This is because the finely dispersed pigment particles reduce light scattering and diffuse reflection, resulting in clearer, more regular dot edges and thus improving the clarity and accuracy of the pattern, meeting the demands of high-precision printing.

[0175] Step (3) Under nitrogen protection, the acrylate oligomer and the remaining monomers are added in three stages at 25-45℃, with each stage spaced 15-25 minutes apart. In the first stage, 30-40% of the acrylate oligomer is added at 25℃ and stirred at low speed (300-400 rpm) to allow the oligomer to slowly integrate into the system and avoid agglomeration due to excessively high local concentrations. In the second stage, the temperature is raised to 35℃ and 30-40% of the oligomer is added and stirred at medium speed (500-600 rpm) to promote initial intermolecular interactions. In the third stage, the remaining components are added at 45℃ and stirred at high speed (800-1000 rpm) to accelerate uniform mixing. At the same time, this temperature is conducive to the movement of active groups in the oligomers and monomers, promoting pre-reaction and entanglement between molecules.

[0176] Comparing the curing speed test data, Comparative Examples 1 to 6, due to improper addition methods or lack of temperature control, all had curing speeds below 11 m / min, while Comparative Example 7 achieved 10 m / min. Examples 1 to 6, through a gradient addition process, achieved more uniform mixing and more thorough intermolecular interactions, resulting in curing speeds of 12 m / min and above, with the fastest reaching 14 m / min. In the rubbing fastness test, Examples 1 to 6 all achieved a rubbing fastness grade of 4 or above, with the highest being 5, significantly better than the comparative examples. This is because the molecular structure formed by thorough mixing and pre-reaction allows for the formation of a denser and stronger cross-linked network during subsequent curing, improving the strength and abrasion resistance of the ink film.

[0177] Blue light irradiation provides a specific excitation wavelength for the photoinitiator, enabling it to efficiently absorb light energy and rapidly generate free radicals to initiate polymerization. The compounded photoinitiator system broadens the absorption spectrum and improves photoinitiation efficiency. The silicone leveling agent, hindered amine light stabilizer, and fluorinated surfactant in the additives are uniformly dispersed in the ink system during stirring, each playing its role: the silicone leveling agent improves the ink's surface tension, resulting in better leveling; the hindered amine light stabilizer enhances the ink's anti-aging properties; and the fluorinated surfactant reduces surface energy, strengthening the ink's anti-fouling and abrasion resistance.

[0178] Examples 1 to 6, processed using this step, showed significantly better curing speed and rubbing fastness than the comparative example. The curing speed increased to 12 m / min or higher, and the rubbing fastness grade reached 4 or higher, while the comparative example's curing speed was below 11 m / min, and the rubbing fastness grade was 3.5 or lower. This indicates that this step, by optimizing the photoinitiation and additive dispersion processes, significantly improved the curing efficiency and overall performance of the ink.

[0179] In summary, through careful design and improvement of the preparation steps, this invention achieves a synergistic improvement in various aspects of UV ink performance, including viscosity stability, dot reproducibility, curing speed, and rubbing fastness, from the microscopic molecular level to the macroscopic ink properties. Compared with traditional inks and comparative products, it has significant technical advantages and application value.

[0180] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A high-stability UV ink, characterized by, Composed of the following components by weight parts: acrylate oligomer 40-60 parts, active diluent monomer 20-30 parts, photoinitiator 5-10 parts, pigment 10-15 parts, dispersant 1-3 parts, stimulus-responsive viscosity modifier 3-8 parts and auxiliary agent 0.5-2 parts; The preparation method of the stimulus-responsive viscosity modifier comprises the following steps: Step (a): 10-15 parts of dimethylaminoethyl methacrylate, 5-8 parts of perfluorooctyl ethyl acrylate and 2-4 parts of light-responsive spiro compound are dissolved in supercritical CO2; Step (b): reaction at 55-65 MPa, 45-55℃ for 1.5-2.5 hours; Step (c): depressurize to normal pressure at a rate gradient of 5 MPa / 10 min to obtain microcapsules with a particle size of 0.5-2 μm; The preparation steps of the light-responsive spiro compound are as follows: Step (d): 2-nitrobenzaldehyde and morpholinyl propylamine are refluxed in ethanol for 3 hours to generate a Schiff base intermediate; Step (e): under argon protection, the intermediate is reacted with 2-hydroxy-1-naphthaldehyde at 120℃ for 6 hours; Step (f): purified by column chromatography, eluent: ethyl acetate and petroleum ether in a volume ratio of 1:5, to obtain purple crystals.

2. The high-stability UV ink according to claim 1, characterized in that: The molar ratio of dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and light-responsive spiro compound is 1.5-2.0:1:0.5-0.

8.

3. The high-stability UV ink according to claim 1, characterized in that: The acrylate oligomer is a compound of polyurethane acrylate and epoxy acrylate in a mass ratio of 2.5-3.5:

1.

4. The high-stability UV ink according to claim 1, characterized in that: The active diluent monomer contains trimethylolpropane triacrylate and ethoxylated bisphenol A diacrylate in a mass ratio of 2-3:

1.

5. The high-stability UV ink according to claim 1, characterized in that: The auxiliary agent, composed of the following components by weight parts: silicone leveling agent 0.3-1 parts, hindered amine light stabilizer 0.1-0.5 parts and fluorine surfactant 0.1-0.5 parts.

6. The high-stability UV ink according to claim 1, characterized in that: The dispersant is a compound of polyester modified polydimethylsiloxane and BYK-163 in a mass ratio of 2:1, and the photoinitiator contains acyl phosphine oxide and α-hydroxy ketone in a mass ratio of 3:

1.

7. A process for the preparation of a UV ink according to any one of claims 1 to 6, characterized in that, Comprising the following steps: Step (1): the stimulus-responsive viscosity modifier is pre-dispersed in 40-50% of the total amount of active diluent monomer, and ultrasonic treatment is carried out at a power of 300-500 W and a frequency of 40 kHz for 20-40 minutes; Step (2): add pigments and dispersants, and ball mill with zirconium oxide beads at a mill cavity temperature of 20℃ for 2-4 hours until the particle size D50≤2 μm; Step (3): under nitrogen protection, add acrylate oligomer and the remaining monomers in three stages at 25-45℃, with an interval of 15-25 minutes between each stage; Step (4) Add photo initiator and adjuvant, irradiate under blue light at wavelength 405 nm, light intensity 10-15 mW / cm 2 Uniformly stir under blue light for 1-1.5 hours.

8. The method of claim 7, wherein: The three-stage gradient addition of step (3) is as follows: First stage: add 30-40% of the acrylate oligomer at 25℃, with a stirring rate of 300-400 rpm; Second stage: add 30-40% of the acrylate oligomer at 35℃, with a stirring rate of 500-600 rpm; Third stage: add the remaining components at 45℃, with a stirring rate of 800-1000 rpm.

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