High gloss water-based silver ink with transfer paper effect, and preparation method and application thereof

Abstract

The present application relates to the technical field of ink, and discloses high-gloss water-based bright silver ink with transfer paper effect and a preparation method and application thereof.The high-gloss water-based bright silver ink comprises 60-70 parts by weight of water-based core-shell acrylic resin emulsion, 30-40 parts by weight of water-based polyurethane emulsion and 10-25 parts by weight of metal pigment, etc.The ink layer obtained by the ink has excellent hardness, flexibility and impact resistance, is not easy to break during processing, has strong bending and cracking resistance, and the ink layer does not burst or peel off after being folded multiple times.Meanwhile, the ink layer has good film-forming property, excellent leveling property and high flatness.The high reflectivity metal pigment such as vacuum aluminum plating is used in the present application, so that the ink layer has high gloss and strong metallic feeling.The high-gloss water-based bright silver ink prepared by the present application can be used on white cardboard or art paper to replace aluminum-plated transfer paper, has similar metallic gloss to the aluminum-plated transfer paper, and can be used to prepare cigarette packets, cosmetic boxes, wine boxes and other products.

Description

Technical Field

[0001] This invention relates to the field of ink technology, specifically to a high-gloss water-based bright silver ink with transfer paper effect, its preparation method, and its application. Background Technology

[0002] For a long time, high-end product packaging such as cigarettes, cosmetics, and alcoholic beverages have widely used aluminized transfer paper or aluminum foil composite paper as printing substrate. These materials, by laminating an extremely thin aluminum layer onto the paper surface, provide excellent metallic luster and smoothness, meeting the visual and tactile requirements of high-end packaging. However, the production of such materials has significant drawbacks. The production process is complex and energy-intensive: traditional aluminized transfer paper requires multiple processes such as PET film coating, vacuum aluminizing, lamination, and peeling, involving a high-energy-consuming vacuum environment and complex lamination processes. Environmental and cost pressures: Although its aluminum layer is very thin and relatively environmentally friendly, the production process still involves issues such as volatile organic compound emissions. The lamination process also limits the ease of paper recycling, and the overall cost is greatly affected by the aluminum material and the lamination process. Printing and processing limitations: Existing technologies attempt to use ordinary paper to print silver ink as a substitute, but often face problems such as insufficient metallic luster, poor leveling, low ink layer hardness and strength, and poor flexibility, leading to problems such as easy breakage and cracking during post-processing (such as die-cutting and folding). For example, existing patented technologies often use a single resin system (such as pure acrylic resin or a blend with nitrocellulose), which falls short in balancing gloss and flexibility. Some technologies employ cold stamping, which, while producing better results, still require additional materials such as laser film, failing to completely eliminate the need for composite processes and offering limited support for light-colored designs.

[0003] With increasingly stringent global environmental regulations and rising demands for cost control, the market urgently needs an innovative solution that can achieve a metallic effect comparable to metallized transfer paper directly on ordinary white cardboard or coated paper through environmentally friendly printing processes, while also possessing excellent processability. This invention aims to overcome the aforementioned shortcomings of existing technologies and provide a novel water-based high-metallic-gloss ink. By designing a unique dual-resin binder system combining a high-gloss core-shell structure acrylic resin and a highly flexible polyurethane resin, a water-based ink with excellent leveling properties, high metallic gloss, and superior flexibility is formulated. Combined with an optimized printing process, it can be directly printed on white cardboard or coated paper to obtain packaging prints that can replace traditional metallized transfer paper. Summary of the Invention

[0004] This invention solves the problem that acrylic coatings are difficult to achieve in terms of both good flexibility and hardness, and the ink layer is prone to cracking and peeling when folded.

[0005] The technical solution of the present invention is: a high-gloss water-based bright silver ink with transfer paper effect and its preparation method. The high-gloss water-based bright silver ink includes 60-70 parts by weight of water-based core-shell acrylic resin emulsion, 30-40 parts by weight of water-based polyurethane emulsion, 10-25 parts by weight of metallic pigment, 0.7-1.2 parts by weight of wetting and dispersing agent, 0.2-0.5 parts by weight of defoamer, 0.4-0.7 parts by weight of leveling agent, and 1.4-2.2 parts by weight of film-forming aid.

[0006] Preferably, the metallic pigments include high-scintillation aluminum pigments and vacuum-plated aluminum metallic pigments.

[0007] Preferably, the film-forming aids include alcohol ester 12, dipropylene glycol methyl ether, and dipropylene glycol butyl ether.

[0008] Preferably, the high-gloss water-based bright silver ink further includes a neutralizing agent, which may include ammonia or triethylamine.

[0009] The preferred method for preparing high-gloss water-based bright silver ink with transfer paper effect is as follows:

[0010] (1) Add dichloromethane, 5-hydroxyisophthalic acid, isocyanate methyl methacrylate, and dibutyltin dilaurate to a reaction vessel. Stir the reaction at 20-30℃ for 3-4 hours, then distill under reduced pressure. Add the product to water, adjust the pH to 2-3 with hydrochloric acid, precipitate the product, filter, and dry to obtain isophthalic acid urethane acrylate monomer. The preparation reaction formula is as follows:

[0011] .

[0012] (2) Add water, butyl acrylate, methyl methacrylate and emulsifier SR-10 to the container, stir and mix to make a core layer pre-emulsion.

[0013] (3) Add water, methyl methacrylate, isophthalic acid urethane monomer, isooctyl acrylate, and emulsifier SR-10 to the container, stir and mix to prepare a shell pre-emulsion.

[0014] (4) Nitrogen gas is introduced into the reaction vessel, water is added, and core layer pre-emulsion and aqueous solution containing initiator are added dropwise. The dropwise addition time is controlled at 2-2.5h, and the temperature is heated to 80-85℃. After the dropwise addition is completed, the reaction is stirred for 1-1.5h. At the same time, shell layer pre-emulsion and aqueous solution containing initiator are added dropwise. The dropwise addition time is controlled at 1-1.5h, and the temperature is heated to 85-90℃. The reaction is stirred for 1-1.5h, cooled, and ammonia water is added dropwise to adjust the pH to 7.5-8 to obtain an aqueous core-shell acrylic resin emulsion.

[0015] (5) Nitrogen gas is introduced into the reaction vessel, and dry polyester polyol, isocyanate monomer and dibutyltin dilaurate are added. The mixture is heated to 75-80℃ and stirred for 2-2.5h. Then acetone and water-based chain extender are added. The temperature is lowered to 40-45℃ and stirred for 20-30min. Diamine chain extender is added and stirred for 20-30min. Water is added for dilution, and triethylamine is added dropwise for neutralization. Acetone is removed by vacuum distillation to obtain water-based polyurethane emulsion.

[0016] (6) Add water-based core-shell acrylic resin emulsion, water-based polyurethane emulsion, wetting and dispersing agent, metallic pigment and defoamer to the dispersion tank, disperse and mix for 30-40 minutes, then add leveling agent and film-forming aid, disperse and mix for 2-3 minutes, add neutralizing agent dropwise, adjust pH to 8-8.5, add water, adjust viscosity to 35-45 seconds for a Forecast 4-cup, pass through a 250-mesh nylon screen to obtain high-gloss water-based bright silver ink with transfer paper effect.

[0017] Preferably, in (1), the amount of 5-hydroxyisophthalic acid is 100 parts by weight, the amount of isocyanate methyl methacrylate is 85-94 parts by weight, and the amount of dibutyltin dilaurate is 1.4-2 parts by weight.

[0018] Preferably, in (2), the amount of butyl acrylate is 36-45 parts by weight, methyl methacrylate is 25-28 parts by weight, and emulsifier SR-10 is 1.3-1.5 parts by weight.

[0019] Preferably, in (3), the amount of methyl methacrylate is 12-15 parts by weight, the amount of isophthalic acid urethane monomer is 4-10 parts by weight, the amount of isooctyl acrylate is 7-9 parts by weight, and the amount of emulsifier SR-10 is 0.8-1.2 parts by weight.

[0020] Preferably, in (5), the amount of polyester polyol is 100 parts by weight, the amount of isocyanate monomer is 19-25 parts by weight, the amount of dibutyltin dilaurate is 0.022-0.028 parts by weight, the amount of water-based chain extender is 5.6-6.4 parts by weight, the amount of diamine chain extender is 1.1-1.4 parts by weight, and the amount of triethylamine is 4.3-4.7 parts by weight.

[0021] Preferably, the initiator in (4) includes ammonium persulfate or potassium persulfate.

[0022] Preferably, in (5), the polyester polyol includes polybutylene adipate.

[0023] Preferably, the isocyanate monomer in (5) includes isophorone diisocyanate.

[0024] Preferably, the aqueous chain extender in (5) includes 2,2-dihydroxymethylpropionic acid.

[0025] Preferably, the diamine chain extender in (5) includes ethylenediamine.

[0026] Preferably, high-gloss water-based bright silver inks with transfer paper effects are used in white cardboard or coated paper to replace metallized transfer paper.

[0027] (1) Substrate preparation: Select white cardboard or coated paper with a basis weight of 200-400 g / m² as the printing substrate.

[0028] (2) Printing high-gloss water-based bright silver ink: The water-based high-metallic ink is printed on the substrate surface in full or according to a pattern using gravure or flexographic printing methods. The cell depth of the gravure printing roller is 28-35μm; the ceramic anilox roller with 180-200 lines / inch is used for flexographic printing. After printing, it is dried in an oven at 80-110℃.

[0029] (3) Printing Color Inks: On the completely dried ink layer, multi-color printing is performed using conventional water-based inks, including base color, top color, and halftone dots. The unique design of the resin system ensures that the ink layer is dense and smooth, and subsequent inks can adhere perfectly, solving problems such as white spots and pinholes that are easy to occur when ordinary water-based inks are overprinted.

[0030] (4) Apply protective varnish: After color printing is completed, apply a layer of water-based or UV varnish to the entire printed surface and cure it to form a protective layer to improve the wear resistance, scratch resistance and overall gloss of the printed product.

[0031] The beneficial technical effects of this invention are as follows: using butyl acrylate, methyl methacrylate, etc. as the core layer, and isobutyl acrylate monomer, isooctyl acrylate, etc. as the shell layer, an aqueous core-shell acrylic resin emulsion is obtained by emulsion polymerization. This emulsion is then compounded with aqueous polyurethane as a binder for ink. When mixed with metal pigments such as vacuum aluminizing with high surface smoothness and light reflectivity, a high-gloss aqueous bright silver ink with a mirror effect similar to aluminized film and the effect of transfer paper is obtained.

[0032] This invention uses isophthalic acid urethane acrylate monomer as the shell layer of acrylic resin, introducing hydrophilic carboxyl groups, as well as benzene rings and urethane groups. The carboxyl groups impart good hydrophilicity and water dispersibility to the acrylic resin, improving the film-forming properties and leveling of the ink layer. The benzene ring structure enhances the strength and hardness of the ink layer. The urethane groups form hydrogen bonds with the urethane groups in the polyurethane, strengthening the interfacial forces and giving the polyurethane better toughening properties. The ink layer possesses excellent hardness, flexibility, and impact resistance, is not easily damaged during processing, has strong resistance to bending and cracking, and exhibits no bursting or peeling even after multiple folds. Simultaneously, the ink layer exhibits good film-forming properties, excellent leveling, and high flatness. Combined with high-reflectivity vacuum metallized metallic pigments, the ink layer achieves high gloss and a strong metallic feel. The prepared high-gloss water-based bright silver ink can be used on white cardboard or coated paper to replace metallized transfer paper, possessing a similar metallic gloss, making it better suited for products such as cigarette packs, cosmetic boxes, and wine boxes. Detailed Implementation

[0033] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In case of any inconsistency, the meaning set forth in this specification or derived from the content described herein shall prevail. Furthermore, the terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit the scope of this application.

[0034] The wetting and dispersing agent listed below, model OT-75, is from Cytec Chemicals. The vacuum metallizing pigment, model PV3407, is from Xiangxi Zuxing Technology Co., Ltd. The defoamer, model DC-65, is from Dow Corning (USA), and the leveling agent, model 104E, is from Gas Chemicals (USA).

[0035] Example 1:

[0036] (1) Add 250 mL of dichloromethane, 40 g of 5-hydroxyisophthalic acid, 34 g of isocyanate methacrylate and 8 g of dibutyltin dilaurate to the reaction vessel. Stir the reaction at 30 °C for 3 h, distill under reduced pressure, add the product to water, add 30% hydrochloric acid to adjust the pH to 3, precipitate out, filter and dry to obtain isophthalic acid urethane acrylate monomer.

[0037] (2) Add 350 mL of water, 400 g of butyl acrylate, 270 g of methyl methacrylate, and 13 g of emulsifier SR-10 to container A, stir and mix to prepare a core layer pre-emulsion; add 300 mL of water, 140 g of methyl methacrylate, 40 g of urethane isophthalate monomer, 80 g of isooctyl acrylate, and 10 g of emulsifier SR-10 to container B, stir and mix to prepare a shell layer pre-emulsion; introduce nitrogen gas into the reaction vessel, and add 1 00 mL of water was added dropwise, along with a core layer pre-emulsion and 220 mL of an aqueous solution containing 12 g of ammonium persulfate. The dropwise addition was controlled for 2.5 h, and the mixture was heated to 80 °C. After the addition was complete, the mixture was stirred for 1.5 h. Then, a shell layer pre-emulsion and an aqueous solution containing 4 g of ammonium persulfate were added dropwise. The dropwise addition was controlled for 1 h, and the mixture was heated to 85 °C. The mixture was stirred for 1.5 h, cooled, and the pH was adjusted to 8 by adding 20% ​​ammonia water. This yielded an aqueous core-shell acrylic resin emulsion.

[0038] (3) Nitrogen gas was introduced into the reaction vessel, and 300g of dry polybutylene adipate (average molecular weight 2000), 73g of isophorone diisocyanate and 66mg of dibutyltin dilaurate were added. The mixture was heated to 80°C and stirred for 2h. Then 60mL of acetone and 19.2g of 2,2-dimethylolpropionic acid were added. The temperature was lowered to 45°C and stirred for 20min. 3.3g of ethylenediamine was added and stirred for 20min. 500mL of water was added for dilution, and 14.1g of triethylamine was added dropwise for neutralization. The acetone was removed by vacuum distillation to obtain an aqueous polyurethane emulsion.

[0039] (4) Add 700g of water-based core-shell acrylic resin emulsion, 300g of water-based polyurethane emulsion, 10g of wetting and dispersing agent, 180g of vacuum aluminized metal pigment, and 3g of defoamer to the dispersion tank, disperse and mix for 40min, then add 4g of leveling agent and 14g of alcohol ester 12, disperse and mix for 2min, add 20% ammonia water by mass, adjust the pH to 8, add water, adjust the viscosity to 40 seconds for a 4-cup, and pass through a 250-mesh nylon screen to obtain a high-gloss water-based bright silver ink with transfer paper effect.

[0040] Example 2:

[0041] (1) Add 300 mL of dichloromethane, 40 g of 5-hydroxyisophthalic acid, 37.6 g of isocyanate methacrylate and 5.6 g of dibutyltin dilaurate to the reaction vessel, stir and react at 20 °C for 4 h, distill under reduced pressure, add the product to water, add 30% hydrochloric acid dropwise to adjust the pH to 2, precipitate out, filter and dry to obtain isophthalic acid urethane acrylate monomer.

[0042] (2) Add 400 mL of water, 450 g of butyl acrylate, 250 g of methyl methacrylate, and 13 g of emulsifier SR-10 to container A, stir and mix to prepare a core layer pre-emulsion; add 300 mL of water, 150 g of methyl methacrylate, 60 g of urethane isophthalate monomer, 70 g of isooctyl acrylate, and 12 g of emulsifier SR-10 to container B, stir and mix to prepare a shell layer pre-emulsion; introduce nitrogen gas into the reaction vessel, and add 100 g of butyl acrylate... mL of water was added dropwise, along with a core-layer pre-emulsion and 220 mL of an aqueous solution containing 10 g of ammonium persulfate. The addition time was controlled at 2.5 h, and the mixture was heated to 80 °C. After the addition was complete, the mixture was stirred and reacted for 1.5 h. Then, a shell-layer pre-emulsion and an aqueous solution containing 100 mL of an aqueous solution containing 5 g of ammonium persulfate were added dropwise. The addition time was controlled at 1.5 h, and the mixture was heated to 85 °C. The mixture was stirred and reacted for 1.5 h. After cooling, 20% ammonia water was added dropwise to adjust the pH to 8, thus obtaining an aqueous core-shell acrylic resin emulsion.

[0043] (3) Nitrogen gas was introduced into the reaction vessel, and 300g of dry polybutylene adipate (average molecular weight 2000), 75g of isophorone diisocyanate and 76mg of dibutyltin dilaurate were added. The mixture was heated to 80°C and stirred for 2 hours. Then 50mL of acetone and 16.8g of 2,2-dimethylolpropionic acid were added. The temperature was lowered to 40°C and stirred for 30 minutes. 4.2g of ethylenediamine was added and stirred for 30 minutes. 500mL of water was added for dilution, and 12.9g of triethylamine was added dropwise for neutralization. The acetone was removed by vacuum distillation to obtain an aqueous polyurethane emulsion.

[0044] (4) Add 600g of water-based core-shell acrylic resin emulsion, 400g of water-based polyurethane emulsion, 12g of wetting and dispersing agent, 250g of vacuum aluminized metal pigment, and 5g of defoamer to the dispersion tank, disperse and mix for 40min, then add 5g of leveling agent and 14g of dipropylene glycol methyl ether, disperse and mix for 3min, add 20% ammonia water by mass, adjust the pH to 8, add water, adjust the viscosity to 45 seconds for a 4-cup, and pass through a 250-mesh nylon screen to obtain a high-gloss water-based bright silver ink with transfer paper effect.

[0045] Example 3:

[0046] (1) Add 300 mL of water, 360 g of butyl acrylate, 280 g of methyl methacrylate, and 15 g of emulsifier SR-10 to container A, stir and mix to prepare a core layer pre-emulsion; add 250 mL of water, 120 g of methyl methacrylate, 80 g of urethane isophthalate monomer (prepared from Example 1), 90 g of isooctyl acrylate, and 8 g of emulsifier SR-10 to container B, stir and mix to prepare a shell layer pre-emulsion; introduce nitrogen gas into the reaction vessel. Add 100 mL of water, and simultaneously add the core layer pre-emulsion and 200 mL of aqueous solution containing 9 g of ammonium persulfate. Control the addition time to 2.5 h, and heat to 80 °C. After the addition is complete, stir and react for 1 h. Simultaneously add the shell layer pre-emulsion and 120 mL of aqueous solution containing 6 g of ammonium persulfate. Control the addition time to 1.5 h, and heat to 85 °C. Stir and react for 1.5 h. Cool, and add 20% ammonia water to adjust the pH to 7.5 to obtain an aqueous core-shell acrylic resin emulsion.

[0047] (2) Nitrogen gas was introduced into the reaction vessel, and 300g of dry polybutylene adipate (average molecular weight 2000), 67g of isophorone diisocyanate and 84mg of dibutyltin dilaurate were added. The mixture was heated to 80°C and stirred for 2 hours. Then 50mL of acetone and 18.3g of 2,2-dimethylolpropionic acid were added. The temperature was lowered to 40°C and stirred for 30 minutes. 3.7g of ethylenediamine was added and stirred for 30 minutes. 450mL of water was added for dilution, and 12.6g of triethylamine was added dropwise for neutralization. The acetone was removed by vacuum distillation to obtain an aqueous polyurethane emulsion.

[0048] (4) Add 650g of water-based core-shell acrylic resin emulsion, 350g of water-based polyurethane emulsion, 10g of wetting and dispersing agent, 220g of vacuum metallized pigment, and 2g of defoamer to the dispersion tank, disperse and mix for 30min, then add 7g of leveling agent and 22g of alcohol ester 12, disperse and mix for 3min, add 20% ammonia water by mass, adjust the pH to 8, add water, adjust the viscosity to 40 seconds for the 4-cup of the Forecast cup, and pass through a 250-mesh nylon screen to obtain a high-gloss water-based bright silver ink with transfer paper effect.

[0049] Example 4:

[0050] (1) Add 400 mL of water, 420 g of butyl acrylate, 260 g of methyl methacrylate, and 14 g of emulsifier SR-10 to container A, stir and mix to prepare a core layer pre-emulsion; add 300 mL of water, 140 g of methyl methacrylate, 100 g of urethane isophthalate monomer (prepared from Example 1), 70 g of isooctyl acrylate, and 12 g of emulsifier SR-10 to container B, stir and mix to prepare a shell layer pre-emulsion; introduce into the reaction vessel Nitrogen gas was added to 100 mL of water, and simultaneously, a core-layer pre-emulsion and a 200 mL aqueous solution containing 10 g of ammonium persulfate were added dropwise. The addition time was controlled at 2.5 h, and the mixture was heated to 85 °C. After the addition was complete, the mixture was stirred and reacted for 1 h. Simultaneously, a shell-layer pre-emulsion and a 80 mL aqueous solution containing 4 g of ammonium persulfate were added dropwise. The addition time was controlled at 1.5 h, and the mixture was heated to 90 °C. The mixture was stirred and reacted for 1 h. After cooling, 20% ammonia water was added dropwise to adjust the pH to 8, thus obtaining an aqueous core-shell acrylic resin emulsion.

[0051] (2) Nitrogen gas was introduced into the reaction vessel, and 300g of dry polybutylene adipate (average molecular weight 2000), 72g of isophorone diisocyanate and 70mg of dibutyltin dilaurate were added. The mixture was heated to 75°C and stirred for 2.5h. Then 60mL of acetone and 17.5g of 2,2-dimethylolpropionic acid were added. The temperature was lowered to 40°C and stirred for 30min. 4g of ethylenediamine was added and stirred for 30min. 500mL of water was added for dilution, and 13.6g of triethylamine was added dropwise for neutralization. The acetone was removed by vacuum distillation to obtain an aqueous polyurethane emulsion.

[0052] (4) Add 650g of water-based core-shell acrylic resin emulsion, 350g of water-based polyurethane emulsion, 7g of wetting and dispersing agent, 180g of vacuum aluminized metal pigment, and 2g of defoamer to the dispersion tank, disperse and mix for 30min, then add 5g of leveling agent and 19g of dipropylene glycol butyl ether, disperse and mix for 3min, add 20% ammonia water by mass, adjust the pH to 8, add water, adjust the viscosity to 40 seconds for a 4-cup, and pass through a 250-mesh nylon screen to obtain a high-gloss water-based bright silver ink with transfer paper effect.

[0053] Comparative Example 1 differs from Example 1 in that acrylic acid is used instead of isophthalic acid urethane acrylate monomer.

[0054] (1) Add 350 mL of water, 400 g of butyl acrylate, 270 g of methyl methacrylate, and 13 g of emulsifier SR-10 to container A, stir and mix to prepare a core layer pre-emulsion; add 300 mL of water, 140 g of methyl methacrylate, 40 g of acrylic acid, 80 g of isooctyl acrylate, and 10 g of emulsifier SR-10 to container B, stir and mix to prepare a shell layer pre-emulsion; introduce nitrogen into the reaction vessel, add 100 mL of water, and simultaneously add the core layer pre-emulsion and 220 mL of aqueous solution containing 12 g of ammonium persulfate, control the addition time for 2.5 h, and heat to 80 °C. After the addition is complete, stir and react for 1.5 h, and simultaneously add the shell layer pre-emulsion and 80 mL of aqueous solution containing 4 g of ammonium persulfate, control the addition time for 1 h, and heat to 85 °C. Stir and react for 1.5 h, cool, and add 20% ammonia water to adjust the pH to 8 to obtain an aqueous core-shell acrylic resin emulsion.

[0055] (2) Add 700g of water-based core-shell acrylic resin emulsion, 300g of water-based polyurethane emulsion, 10g of wetting and dispersing agent, 180g of vacuum-metallized metal pigment, and 3g of defoamer to a dispersion tank, disperse and mix for 40min, then add 4g of leveling agent and 14g of alcohol ester 12, disperse and mix for 2min, add 20% ammonia water by mass, adjust the pH to 8, add water, adjust the viscosity to 40 seconds for a 4-cup, and pass through a 250-mesh nylon screen to obtain ink.

[0056] Comparative Example 2 differs from Example 1 in that acrylic acid and styrene are used instead of isophthalic acid urethane acrylate monomers.

[0057] (1) Add 350mL of water, 400g of butyl acrylate, 270g of methyl methacrylate, and 13g of emulsifier SR-10 to container A, stir and mix to prepare a core layer pre-emulsion; add 300mL of water, 140g of methyl methacrylate, 20g of acrylic acid, 20g of styrene, 80g of isooctyl acrylate, and 10g of emulsifier SR-10 to container B, stir and mix to prepare a shell layer pre-emulsion; introduce nitrogen gas into the reaction vessel, and add 100 mL of water was added dropwise, along with a core layer pre-emulsion and 220 mL of an aqueous solution containing 12 g of ammonium persulfate. The addition time was controlled at 2.5 h, and the mixture was heated to 80 °C. After the addition was complete, the mixture was stirred and reacted for 1.5 h. Then, a shell layer pre-emulsion and 80 mL of an aqueous solution containing 4 g of ammonium persulfate were added dropwise. The addition time was controlled at 1 h, and the mixture was heated to 85 °C. The mixture was stirred and reacted for 1.5 h. After cooling, 20% ammonia water was added dropwise to adjust the pH to 8, thus obtaining an aqueous core-shell acrylic resin emulsion.

[0058] (2) Add 700g of water-based core-shell acrylic resin emulsion, 300g of water-based polyurethane emulsion, 10g of wetting and dispersing agent, 180g of vacuum-metallized metal pigment, and 3g of defoamer to a dispersion tank, disperse and mix for 40min, then add 4g of leveling agent and 14g of alcohol ester 12, disperse and mix for 2min, add 20% ammonia water by mass, adjust the pH to 8, add water, adjust the viscosity to 40 seconds for a 4-cup, and pass through a 250-mesh nylon screen to obtain ink.

[0059] Comparative Example 3 differs from Example 1 in that it uses isophthalic acid acrylate monomer instead of isophthalic acid urethane acrylate monomer.

[0060] (1) Isophthalic acid acrylate (H2HIAAC) was prepared according to the method described in the journal article *New Journal of Chemistry*, 2019, vol.43, #26, pp.10232-10236, "Post-synthetic modification of a Tb-based metal–organic framework for highly selective and sensitive detection of metal ions in aqueous solution". The structural formula is as follows: .

[0061] (1) Add 350mL of water, 400g of butyl acrylate, 270g of methyl methacrylate, and 13g of emulsifier SR-10 to container A, stir and mix to prepare a core layer pre-emulsion; add 300mL of water, 140g of methyl methacrylate, 20g of acrylic acid, 20g of styrene, 80g of isooctyl acrylate, and 10g of emulsifier SR-10 to container B, stir and mix to prepare a shell layer pre-emulsion; introduce nitrogen gas into the reaction vessel, and add 100 mL of water was added dropwise, along with a core layer pre-emulsion and 220 mL of an aqueous solution containing 12 g of ammonium persulfate. The addition time was controlled at 2.5 h, and the mixture was heated to 80 °C. After the addition was complete, the mixture was stirred and reacted for 1.5 h. Then, a shell layer pre-emulsion and 80 mL of an aqueous solution containing 4 g of ammonium persulfate were added dropwise. The addition time was controlled at 1 h, and the mixture was heated to 85 °C. The mixture was stirred and reacted for 1.5 h. After cooling, 20% ammonia water was added dropwise to adjust the pH to 8, thus obtaining an aqueous core-shell acrylic resin emulsion.

[0062] (2) Add 700g of water-based core-shell acrylic resin emulsion, 300g of water-based polyurethane emulsion, 10g of wetting and dispersing agent, 180g of vacuum-metallized metal pigment, and 3g of defoamer to a dispersion tank, disperse and mix for 40min, then add 4g of leveling agent and 14g of alcohol ester 12, disperse and mix for 2min, add 20% ammonia water by mass, adjust the pH to 8, add water, adjust the viscosity to 40 seconds for a 4-cup, and pass through a 250-mesh nylon screen to obtain ink.

[0063] Comparative Example 4: The main difference between this comparative example and Example 1 is that phenol is used instead of 5-hydroxyisophthalic acid.

[0064] (1) Add 250 mL of dichloromethane, 20.66 g of phenol, 34 g of isocyanate methacrylate, and 8 g of dibutyltin dilaurate to a reaction vessel. Stir the reaction at 30 °C for 3 h. Distill under reduced pressure, wash the product with petroleum ether, and then recrystallize from ethanol to obtain phenylamino acrylate monomer with the following structural formula: .

[0065] (2) Add 350 mL of water, 400 g of butyl acrylate, 270 g of methyl methacrylate, and 13 g of emulsifier SR-10 to container A, stir and mix to prepare a core layer pre-emulsion; add 300 mL of water, 140 g of methyl methacrylate, 40 g of phenylamino acrylate monomer, 80 g of isooctyl acrylate, and 10 g of emulsifier SR-10 to container B, stir and mix to prepare a shell layer pre-emulsion; introduce nitrogen gas into the reaction vessel, and add 10 g of emulsifier SR-10. 0 mL of water was added dropwise, along with a core-layer pre-emulsion and 220 mL of an aqueous solution containing 12 g of ammonium persulfate. The addition time was controlled at 2.5 h, and the mixture was heated to 80 °C. After the addition was complete, the mixture was stirred and reacted for 1.5 h. Simultaneously, a shell-layer pre-emulsion and an aqueous solution containing 4 g of ammonium persulfate were added dropwise. The addition time was controlled at 1 h, and the mixture was heated to 85 °C. The mixture was stirred and reacted for 1.5 h. After cooling, 20% ammonia water was added dropwise to adjust the pH to 8, thus obtaining a core-shell acrylic resin emulsion.

[0066] (3) Add 700g of water-based core-shell acrylic resin emulsion, 300g of water-based polyurethane emulsion, 10g of wetting and dispersing agent, 180g of vacuum-metallized metal pigment, and 3g of defoamer to a dispersion tank, disperse and mix for 40min, then add 4g of leveling agent and 14g of alcohol ester 12, disperse and mix for 2min, add 20% ammonia water by mass, adjust the pH to 8, add water, adjust the viscosity to 40 seconds for a 4-cup, and pass through a 250-mesh nylon screen to obtain ink.

[0067] Example 5, Printing application of ink:

[0068] (1) Substrate: 250g / m 2 White cardstock.

[0069] (2) Printing ink (prepared from Example 1): A gravure printing press with a cell depth of 32 μm was used for full-page printing. The oven temperature was set to three levels: 90°C, 100°C, and 90°C, and the air speed and exhaust volume were adjusted until the ink layer was completely dry.

[0070] (3) Printing ink: Print the pattern on the dried ink layer using commercially available water-based four-color ink for cigarette packs.

[0071] (4) Polishing: Finally, apply water-based abrasion-resistant varnish online and dry it with infrared and hot air.

[0072] The impact resistance of the cured film of the ink is tested according to standard GB / T 1732-2020. The flexibility is tested according to standard GB / T1731-2020. The hardness is tested according to standard GB / T 6739-2022.

[0073] The gloss of the ink layer at 60° was tested using a gloss meter at a temperature of 23°C and a relative humidity of 65%. Three points were randomly selected from the top, middle and bottom of the ink layer, and the gloss count values ​​were read and averaged.

[0074] The ink-printed material was folded 180° along the crease line using a folding endurance tester, and the ink layer was observed after 10 folds.

[0075] Table 1 Performance Tests

[0076]

[0077] Compared to Comparative Examples 1 to 4, Example 1 uses a water-based core-shell acrylic resin emulsion and a water-based polyurethane emulsion as binders for the ink. The added isophthalic acid urethane acrylate monomer introduces hydrophilic carboxyl groups, as well as benzene rings and urethane groups into the acrylic resin shell layer. The carboxyl groups can impart good hydrophilicity and water dispersibility to the acrylic resin, improving the film-forming properties and leveling properties of the ink layer. The benzene ring structure can improve the strength and hardness of the ink layer. The urethane groups can form hydrogen bonds with the urethane groups in the polyurethane, enhancing the interfacial forces between the two and giving the polyurethane better toughening properties. The ink layer has excellent flexibility and impact resistance, strong resistance to bending cracking, and no cracking or peeling after multiple folds. At the same time, the ink layer has good film-forming properties, excellent leveling properties, and high flatness. Combined with high-reflectivity vacuum metallized and other metallic pigments, the ink layer has high gloss and a strong metallic feel. In Examples 2 to 4, inks prepared by adjusting different ratios of waterborne core-shell acrylic resin emulsion and waterborne polyurethane emulsion also exhibited excellent impact resistance, flexibility, pencil hardness, and gloss.

[0078] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the scope of protection of the present invention.

Claims

1. A high-gloss water-based bright silver ink with transfer paper effect, characterized in that, The high-gloss water-based bright silver ink comprises: 60-70 parts by weight of water-based core-shell acrylic resin emulsion, 30-40 parts by weight of water-based polyurethane emulsion, 10-25 parts by weight of metallic pigment, 0.7-1.2 parts by weight of wetting and dispersing agent, 0.2-0.5 parts by weight of defoamer, 0.4-0.7 parts by weight of leveling agent, and 1.4-2.2 parts by weight of film-forming aid; The high-gloss water-based bright silver ink also includes a neutralizing agent.

2. The high-gloss water-based bright silver ink with transfer paper effect according to claim 1, characterized in that, The metallic pigments include high-scintillation aluminum pigments and vacuum-plated aluminum metallic pigments.

3. The high-gloss water-based bright silver ink with transfer paper effect according to claim 1, characterized in that, The film-forming aids include alcohol ester 12, dipropylene glycol methyl ether, and dipropylene glycol butyl ether.

4. The high-gloss water-based bright silver ink with transfer paper effect according to claim 1, characterized in that, The neutralizing agent includes ammonia or triethylamine.

5. A method for preparing a high-gloss water-based bright silver ink with transfer paper effect as described in any one of claims 1-4, characterized in that, The preparation method is as follows: add water-based core-shell acrylic resin emulsion, water-based polyurethane emulsion, wetting and dispersing agent, metallic pigment, and defoamer to a dispersion tank, disperse and mix for 30-40 minutes, then add leveling agent and film-forming aid, disperse and mix for 2-3 minutes, add neutralizing agent dropwise, adjust pH to 8-8.5, add water, adjust viscosity to 35-45 seconds for a Forecast 4-cup, sieve, and obtain a high-gloss water-based bright silver ink with transfer paper effect.

6. The method for preparing high-gloss water-based bright silver ink with transfer paper effect according to claim 5, characterized in that, The preparation method of the aqueous core-shell acrylic resin emulsion is as follows: (1) Add dichloromethane, 100 parts by weight of 5-hydroxyisophthalic acid, 85-94 parts by weight of isocyanate methacrylate, and 1.4-2 parts by weight of dibutyltin dilaurate to the reaction vessel. Stir the reaction at 20-30℃ for 3-4 hours, distill under reduced pressure, add the product to water, add hydrochloric acid to adjust the pH to 2-3, precipitate the precipitate, filter and dry to obtain isophthalic acid urethane acrylate monomer; (2) Add water, 36-45 parts by weight of butyl acrylate, 25-28 parts by weight of methyl methacrylate, and 1.3-1.5 parts by weight of emulsifier SR-10 to a container, stir and mix to prepare a core layer pre-emulsion; (3) Add water, 12-15 parts by weight of methyl methacrylate, 4-10 parts by weight of urethane isophthalate monomer, 7-9 parts by weight of isooctyl acrylate, and 0.8-1.2 parts by weight of emulsifier SR-10 to the container, stir and mix to prepare a shell pre-emulsion. (4) Nitrogen gas is introduced into the reaction vessel, water is added, and core layer pre-emulsion and aqueous solution containing 0.9-1.2 parts by weight of initiator are added dropwise. The dropwise addition time is controlled at 2-2.5 h, and the temperature is heated to 80-85℃. After the dropwise addition is completed, the reaction is stirred for 1-1.5 h. At the same time, shell layer pre-emulsion and aqueous solution containing 0.4-0.6 parts by weight of initiator are added dropwise. The dropwise addition time is controlled at 1-1.5 h, and the temperature is heated to 85-90℃. The reaction is stirred for 1-1.5 h, cooled, and ammonia water is added dropwise to adjust the pH to 7.5-8 to obtain an aqueous core-shell acrylic resin emulsion.

7. The method for preparing high-gloss water-based bright silver ink with transfer paper effect according to claim 6, characterized in that, The initiator includes ammonium persulfate or potassium persulfate.

8. The method for preparing high-gloss water-based bright silver ink with transfer paper effect according to claim 7, characterized in that, The method for preparing the waterborne polyurethane emulsion is as follows: nitrogen gas is introduced into the reaction vessel, 100 parts by weight of dry polyester polyol, 19-25 parts by weight of isocyanate monomer, and 0.022-0.028 parts by weight of dibutyltin dilaurate are added, the mixture is heated to 75-80℃, and stirred for 2-2.5 hours. Then, acetone and 5.6-6.4 parts by weight of waterborne chain extender are added, the temperature is lowered to 40-45℃, and the mixture is stirred for 20-30 minutes. Then, 1.1-1.4 parts by weight of diamine chain extender are added, and the mixture is stirred for 20-30 minutes. Water is added for dilution, and 4.3-4.7 parts by weight of triethylamine are added dropwise for neutralization. The acetone is removed by vacuum distillation to obtain the waterborne polyurethane emulsion.

9. The method for preparing high-gloss water-based bright silver ink with transfer paper effect according to claim 8, characterized in that, The polyester polyol includes polybutylene adipate, the isocyanate monomer includes isophorone diisocyanate, the aqueous chain extender includes 2,2-dimethylolpropionic acid, and the diamine chain extender includes ethylenediamine.

10. The application of a high-gloss water-based bright silver ink with transfer paper effect obtained by the preparation method as described in claim 9 in white cardboard or coated paper.

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