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CN-121991551-A - Low-VOC environment-friendly water-based UV inkjet ink and preparation method thereof

CN121991551ACN 121991551 ACN121991551 ACN 121991551ACN-121991551-A

Abstract

The application discloses low-VOC environment-friendly water-based UV inkjet ink and a preparation method thereof, and relates to the technical field of inkjet printing materials. The ink takes a composite resin system as a core film forming matrix, the composite resin system is formed by compounding a water-based polyurethane acrylate dispersoid and a nano silicon dioxide-acrylic acid compound, and the product is obtained after high-pressure homogenization, water-based carrier adjustment and anti-yellowing agent modification and filtration by sequentially adding an active monomer and a photoinitiator dispersoid. The application uses water as a main dispersion medium to replace the traditional organic solvent, reduces VOC emission from a root, combines flexibility and rigidity, ensures quick curing of ink by the photoinitiator dispersoid, and inhibits aging and yellowing of the ink film by the anti-yellowing agent. The ink has the advantages of low VOC, strong film forming adhesive force, yellowing resistance and the like.

Inventors

  • LIU JINDE
  • SHI LEI

Assignees

  • 北京联创佳艺影像新材料技术有限公司

Dates

Publication Date
20260508
Application Date
20260310

Claims (10)

  1. 1. The preparation method of the low-VOC environment-friendly water-based UV inkjet ink is characterized by comprising the following steps: Pre-dispersing the composite resin system to obtain a pretreated composite resin system; sequentially adding active monomers and photoinitiator dispersoids into the pretreated composite resin system, stirring and mixing to form a premix; Homogenizing the premix under high pressure, adding an aqueous carrier, and then adding an anti-yellowing agent and stirring to obtain a mixed solution; filtering the regulated mixed solution to obtain low-VOC environment-friendly water-based UV inkjet ink; wherein the active monomer is polyethylene glycol diacrylate or trimethylolpropane triacrylate; the composite resin system is prepared by compounding a water-based polyurethane acrylate dispersion and a nano silicon dioxide-acrylic acid compound; The aqueous polyurethane acrylate dispersion is prepared from diisocyanate and hydroxyalkyl acrylate; The nano silicon dioxide-acrylic acid compound is prepared from nano silicon dioxide, a silane coupling agent and acrylic acid emulsion.
  2. 2. The method for preparing the low-VOC environment-friendly water-based UV inkjet ink according to claim 1 wherein the method for preparing the water-based polyurethane acrylate dispersion comprises the following steps: Under the protection of nitrogen, mixing diisocyanate and hydroxyalkyl acrylate according to the mass ratio of (1.5-2.5): 1, adding a catalyst accounting for 0.01% -0.1% of the total mass of reactants, and reacting for 1-3 hours at 60-90 ℃ to generate polyurethane prepolymer; and adding a chain extender into the polyurethane prepolymer, continuously reacting for 1-2 hours, cooling to 40-50 ℃, adding ammonia water, adding deionized water, and stirring for 30-60 minutes to obtain the aqueous polyurethane acrylate dispersion.
  3. 3. The method for preparing the low-VOC environment-friendly water-based UV inkjet ink according to claim 1, wherein the method for preparing the nano silica-acrylic acid compound comprises the following steps: Adding nano silicon dioxide into deionized water, performing ultrasonic dispersion for 10-20 min, adding a silane coupling agent according to the mass ratio of the nano silicon dioxide to the silane coupling agent of (90-95) (5-10), heating to 60-80 ℃, stirring and reacting for 1-2 h, and drying to obtain modified nano silicon dioxide; Mixing and stirring the acrylic emulsion and the modified nano silicon dioxide according to the mass ratio of (8-10): 1 for 10-15 min to obtain the nano silicon dioxide-acrylic compound.
  4. 4. The method for preparing the low-VOC environment-friendly water-based UV inkjet ink according to claim 1 wherein the preparation method of the composite resin system is as follows: Mixing the aqueous polyurethane acrylate dispersion with the nano silicon dioxide-acrylic acid compound according to the mass ratio of (4-6) to 1, and stirring and dispersing at 35-45 ℃ for 0.5-1 h to obtain a composite resin system.
  5. 5. The method for preparing the low-VOC environmental-friendly water-based UV inkjet ink according to claim 2 wherein the diisocyanate comprises any one of toluene diisocyanate or diphenylmethane diisocyanate; the catalyst comprises any one of dibutyl tin dilaurate or triethylene diamine; the hydroxyalkyl acrylate comprises any one of 2-hydroxyethyl acrylate or hydroxypropyl acrylate; the chain extender comprises any one of dimethylolpropionic acid or dimethylolbutyric acid; The mass ratio of the polyurethane prepolymer, the chain extender and the ammonia water in the aqueous polyurethane acrylate dispersion is (85-93)/(5-10)/(2-5).
  6. 6. The preparation method of the low-VOC environment-friendly water-based UV inkjet ink according to claim 3, wherein the mass ratio of the silane coupling agent to the ethanol to the deionized water in the silane coupling agent solution is (5-8): 80-90): 2-15; The silane coupling agent comprises any one of gamma-glycidyl ether oxypropyl trimethoxy silane or gamma-aminopropyl triethoxy silane.
  7. 7. The preparation method of the low-VOC environment-friendly water-based UV ink-jet ink is characterized in that the pre-dispersion treatment condition is that the temperature is 35-45 ℃ and the stirring time is 0.5-1 h; The stirring and mixing time is 1-2 hours; the high-pressure homogenizing pressure is 15-25 MPa, the homogenizing times are 1-3, and the system viscosity is regulated to 8.5m ~11.5m ; The filtering condition is that a nylon filter screen with 200-300 meshes is adopted for filtering.
  8. 8. The preparation method of the low-VOC environment-friendly water-based UV inkjet ink is characterized by comprising the steps of mixing a microencapsulated photoinitiator with a water-based photoinitiator dispersion according to a mass ratio (2-4): 1, adding deionized water to dilute to 15% -25% by mass fraction, and performing ultrasonic dispersion for 10-20 min to obtain the photoinitiator dispersion; The micro-encapsulation photoinitiator consists of a2, 4, 6-trimethyl benzoyl-diphenyl phosphine oxide capsule core and a polyurea capsule wall, wherein the active ingredient of the aqueous photoinitiator dispersoid is 2,4, 6-trimethyl benzoyl-diphenyl phosphine oxide.
  9. 9. The preparation method of the low-VOC environment-friendly water-based UV inkjet ink according to claim 1, wherein the mass ratio of the composite resin system to the active monomer to the photoinitiator dispersion to the water-based carrier to the anti-yellowing agent is (20-35): 10-12): 3-6): 42-66): 1-5; the anti-yellowing agent comprises any one of pentaerythritol tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] or UV-531; the aqueous carrier is obtained by mixing deionized water and ethanol according to a mass ratio of (5-10): 1.
  10. 10. A low VOC environmental protection aqueous UV inkjet ink prepared by the method of any one of claims 1 to 9.

Description

Low-VOC environment-friendly water-based UV inkjet ink and preparation method thereof Technical Field The application relates to the technical field of ink-jet printing materials, in particular to low-VOC environment-friendly water-based UV ink-jet ink and a preparation method thereof. Background Along with the rising global environmental awareness, the printing industry has increasingly stringent requirements for green environmental protection materials, and low-VOC and pollution-free inkjet ink becomes the core direction of industry transformation. The traditional solvent type ink-jet ink takes an organic solvent as a main dispersion medium, the VOC content is high, a large amount of harmful gas is released in the production and use processes, the atmospheric pollution is caused, the health of operators can be endangered, and the application scene of the ink-jet ink is strictly limited by environmental protection regulations. However, the existing aqueous UV inkjet ink still has a plurality of technical bottlenecks, and it is difficult to combine the environmental protection property and the comprehensive application property. In terms of a resin system, most products depend on single type of resin, so that mechanical properties are unbalanced after film formation, or the film is insufficient in flexibility, poor in friction resistance and impact resistance, or insufficient in rigidity, and cannot meet the requirements of industrial printing on the hardness of an ink film, so that the storage stability of the ink is affected, a printing nozzle is blocked, and the printing precision is reduced. Therefore, there is a need to develop a low-VOC environment-friendly inkjet ink and simultaneously construct a novel formulation system that combines environmental protection, mechanical properties, stability and yellowing resistance. Disclosure of Invention The application aims to overcome the defects of the prior art, and provides the low-VOC environment-friendly water-based UV inkjet ink and the preparation method thereof, wherein the film forming performance, the stability and the yellowing resistance of the ink are improved while the VOC emission is greatly reduced by constructing a composite resin system and optimizing the functions of functional components, so that the problem that the environment-friendly performance and the service performance of the conventional water-based UV inkjet ink are difficult to be compatible is solved, and the requirements of the market on green and high-efficiency printing materials are met. In order to achieve the above purpose, the application adopts the following technical scheme: in a first aspect, the application provides a method for preparing a low-VOC environmental-friendly aqueous UV inkjet ink, comprising: pre-dispersing the composite resin system to obtain a pretreated composite resin system; sequentially adding active monomers and photoinitiator dispersoids into the pretreated composite resin system, stirring and mixing to form a premix; Homogenizing the premix under high pressure, adding an aqueous carrier, and then adding an anti-yellowing agent and stirring to obtain a mixed solution; filtering the regulated mixed solution to obtain low-VOC environment-friendly water-based UV inkjet ink; The active monomer is polyethylene glycol diacrylate or trimethylolpropane triacrylate, and is used as an active diluent for UV curing, and can be subjected to free radical polymerization with a resin matrix in the subsequent photo-curing process, so that the crosslinking density of a film is improved; The composite resin system is prepared by compounding a water-based polyurethane acrylate dispersion and a nano silicon dioxide-acrylic acid compound; the aqueous polyurethane acrylate dispersion is prepared from diisocyanate and hydroxyalkyl acrylate; The nano silicon dioxide-acrylic acid compound is prepared from nano silicon dioxide, a silane coupling agent and acrylic emulsion. Further, the preparation method of the aqueous polyurethane acrylate dispersion comprises the following steps: Under the protection of nitrogen, mixing diisocyanate and hydroxyalkyl acrylate according to the mass ratio of (1.5-2.5): 1, adding a catalyst accounting for 0.01% -0.1% of the total mass of reactants, and reacting for 1-3 hours at 60-90 ℃ to generate polyurethane prepolymer; and adding a chain extender into the polyurethane prepolymer, continuously reacting for 1-2 hours, cooling to 40-50 ℃, adding ammonia water, adding deionized water, and stirring for 30-60 minutes to obtain the aqueous polyurethane acrylate dispersion. In the composite resin system, diisocyanate molecules are provided with isocyanate groups (-NCO), hydroxyalkyl acrylate molecules are provided with hydroxyl groups (-OH), nucleophilic addition reaction is carried out on the diisocyanate molecules and the hydroxyl groups (-OH) under the action of a catalyst, electron-deficient carbon atoms in the isocyanate groups are attacked b