Composite water-based blotting paint, preparation method and application thereof

Abstract

The application discloses a kind of composite water-based transfer printing coating and its preparation method and application.The composite water-based transfer printing coating, raw material includes the following components: component A: water-based modified hydroxyl acrylic polyurethane, auxiliary one and water;Component B: water dispersion isocyanate curing agent;Component C: water-based ultraviolet curing polyurethane resin one, photoinitiator, auxiliary two and water;Component D: water-based ultraviolet curing polyurethane resin two, water-based ultraviolet curing polyurethane resin three, photoinitiator, auxiliary three and water;The functionality of the water-based ultraviolet curing polyurethane resin two>the functionality of the water-based ultraviolet curing polyurethane resin three>the functionality of the water-based ultraviolet curing polyurethane resin one.The water-based transfer printing coating of the application has the advantages of flexibility, chemical resistance, scratch resistance, fast curing, and has excellent adhesion.

Description

Technical Field

[0001] This invention relates to the field of water-based printing coating technology, and in particular to a composite water-based printing coating, its preparation method, and its application. Background Technology

[0002] Imprint coating is an emerging coating technology. The process involves using a silicone mold to imprint a texture onto the coating surface before the UV layer cures. LED lights then cure the texture, "copying" it onto the coating surface and enhancing its aesthetic and decorative effect. Currently, imprint coatings on the market typically consist of a base coat, a mid-coat UV texture layer, and a top coat UV protective layer. The base coat primarily ensures adhesion to the substrate and provides color. The mid-coat UV texture layer provides adhesion to both the base coat and the top coat UV protective layer, while also ensuring the imprintability and release properties of the silicone mold texture. The top coat UV protective layer, located on the outermost layer, not only provides the imprintability and release properties of the silicone mold texture but also exhibits excellent wear resistance, chemical resistance, and stain resistance.

[0003] During the printing process, the coating is in a vacuum, effectively isolating it from the oxygen required for UV curing. Therefore, LED curing significantly increases the polymerization and cross-linking speed of the coating surface, resulting in a higher cross-linking density after curing and thus significantly improving its physical and chemical properties. This technology has been widely used in the 3C electronics industry. However, currently, mainstream printing coatings on the market are still mainly solvent-based, with VOC content typically exceeding 420g / L, posing a significant environmental impact.

[0004] However, water-based printing coatings offer significant advantages in environmental performance compared to other types. Nevertheless, existing water-based printing coatings still face some challenges in practical applications. For example, they currently cannot effectively balance flexibility and chemical resistance: maintaining a hardness ≥500g4H for extended periods (168 hours) under high temperature and humidity conditions (65℃ / 90% relative humidity) without cracking. Furthermore, chemical resistance tests to oleic acid and triethanolamine show that the coating may bubble or peel off. Additionally, the adhesion of the topcoat UV protective layer of water-based printing coatings to the intermediate UV texture layer is difficult to consistently achieve ≥4B, and after prolonged testing under high temperature and humidity conditions (boiling at 85℃ for 8 hours or 65℃ / 90% relative humidity for 504 hours), the adhesion may decrease to <4B. These issues affect the coating's lifespan, and in daily use, the coated surface may show minor scratches from contact with items such as keys, fruit knives, brushes, and cosmetic mirrors.

[0005] Therefore, given the current limitations of water-based printing coatings, it is necessary to further research and improve them to overcome the shortcomings of existing technologies. Summary of the Invention

[0006] The purpose of this invention is to provide a composite water-based printing coating that combines flexibility, chemical resistance, and fast drying, and also has good scratch resistance and coating adhesion.

[0007] The first aspect of the present invention is:

[0008] A composite water-based printing coating is provided.

[0009] The second aspect of the present invention is as follows:

[0010] A water-based printing coating is provided.

[0011] The third aspect of the present invention is:

[0012] A method for preparing an aqueous imprinting coating is provided.

[0013] The fourth aspect of this invention is:

[0014] The application of the water-based printing coating is provided.

[0015] Specifically, the technical solution adopted according to the first aspect of the present invention is as follows:

[0016] A composite water-based printing coating, wherein the raw materials of the water-based printing coating include the following components:

[0017] Component A: Waterborne modified hydroxyl acrylic polyurethane, additive 1, and water;

[0018] Component B: Water-dispersible isocyanate curing agent;

[0019] Component C: Waterborne UV-curable polyurethane resin I, photoinitiator, additive II, and water;

[0020] Component D: Waterborne UV-curable polyurethane resin II, Waterborne UV-curable polyurethane resin III, Photoinitiator, Additives III, and Water;

[0021] The functionality of the second waterborne UV-curable polyurethane resin is greater than that of the third waterborne UV-curable polyurethane resin, which in turn is greater than that of the first waterborne UV-curable polyurethane resin.

[0022] According to embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0023] In the coating of this invention, firstly, the water-based modified hydroxyl acrylic polyurethane in component A provides the basic framework of the coating. This polymer not only has good elasticity and flexibility, but also contains hydroxyl and acrylate groups, enabling it to undergo a crosslinking reaction. The water-dispersible isocyanate curing agent in component B contains isocyanate groups, which react with the hydroxyl groups in component A to form strong chemical bonds. This chemical crosslinking firmly fixes the coating to the substrate surface, significantly enhancing adhesion.

[0024] Secondly, components C and D of the coating contain waterborne UV-curable polyurethane resin and a photoinitiator. These resins possess various functional groups, such as acryloyl and hydroxyl groups, which can undergo UV curing reactions under the action of the photoinitiator. The UV photoinitiator generates free radicals or ions under UV irradiation, promoting cross-linking and cross-chaining reactions between polymers to form a three-dimensional network structure. This cross-linked network not only enhances the mechanical properties of the coating but also effectively improves its adhesion to the substrate.

[0025] Finally, the functionality of waterborne UV-curable polyurethane resin II is higher than that of waterborne UV-curable polyurethane resin III, while that of waterborne UV-curable polyurethane resin I is the lowest. Resins with higher functionality provide more reaction sites, allowing for more effective chemical bonding with other components; resins with lower functionality play a connecting role in chemical crosslinking, enhancing the overall bonding strength of the coating and forming stronger crosslinked networks and more robust adhesion.

[0026] Furthermore, the water-based printing coating of the present invention combines flexibility and chemical resistance, and can remain crack-free for a long time under extreme conditions, while maintaining high adhesion.

[0027] The water-based printing coating roller of this invention showed no scratches on the test surface and will not be scratched by metal, plastic or other everyday materials during daily use, thus avoiding surface scratches that affect its appearance.

[0028] The LED energy (UVV: 2500-3000 mJ / cm²) required for printing with the water-based printing coating of this invention 2 The curing time is only 3 seconds to complete the printing process, which is consistent with solvent-based printing coatings and does not affect production capacity.

[0029] According to one embodiment of the present invention, the raw materials of the water-based printing coating include the following components in parts by weight:

[0030] Component A: 60-80 parts of waterborne modified hydroxyl acrylic polyurethane;

[0031] Component B: 70-90 parts of water-dispersible isocyanate curing agent;

[0032] Component C: 85-90 parts of waterborne UV-curable polyurethane resin and 2-6 parts of photoinitiator;

[0033] Component D: 35-55 parts of waterborne UV-curable polyurethane resin II, 35-55 parts of waterborne UV-curable polyurethane resin III, and 2-6 parts of photoinitiator.

[0034] According to one embodiment of the present invention, the raw materials of the water-based printing coating include the following components in parts by weight:

[0035] Component A: 60-80 parts of waterborne modified hydroxyl acrylic polyurethane and 10-20 parts of water;

[0036] Component B: 70-90 parts of water-dispersible isocyanate curing agent;

[0037] Component C: 85-90 parts of waterborne UV-curable polyurethane resin, 2-6 parts of photoinitiator, and 5-10 parts of water;

[0038] Component D: 35-55 parts of waterborne UV-curable polyurethane resin; 35-55 parts of waterborne UV-curable polyurethane resin; 2-6 parts of photoinitiator and 2-8 parts of water.

[0039] According to one embodiment of the present invention, the raw materials of the water-based printing coating include the following components in parts by weight:

[0040] Component A: 60-80 parts of waterborne modified hydroxyl acrylic polyurethane, 10-20 parts of additive one and 10-20 parts of water;

[0041] Component B: 70-90 parts of water-dispersible isocyanate curing agent;

[0042] Component C: 85-90 parts of waterborne UV-curable polyurethane resin, 0.2-0.5 parts of additives, 2-6 parts of photoinitiator, and 5-10 parts of water;

[0043] Component D: 35-55 parts of waterborne UV-curable polyurethane resin; 35-55 parts of waterborne UV-curable polyurethane resin; 3-6 parts of additives; 2-6 parts of photoinitiator and 2-8 parts of water.

[0044] According to one embodiment of the present invention, the functionality of the waterborne UV-curable polyurethane resin is 2-3.

[0045] According to one embodiment of the present invention, the waterborne UV-curable polyurethane resin includes WU3202 from Wuxing Chemical Co., Ltd., which has a functionality of 2.

[0046] The WU3202 waterborne UV-curable polyurethane resin from Wuxing Chemical Co., Ltd. used in this invention has a functionality of 2 and excellent flexibility, providing excellent flexibility and adhesion for the coating of this invention.

[0047] Specifically, when this resin is combined with the base coating and the UV protective coating of the present invention, it can synergistically balance the flexibility and hardness of the entire imprint coating, so that the coating hardness of the present invention can reach 500g*4H, and at this hardness, the coating can still remain uncracking under the condition of bending at 45°.

[0048] The combination of the water-based UV-curable polyurethane resin and the initiator selected in this invention results in the coating exhibiting excellent mirror-like leveling and fullness in the wet film after baking, leading to clearer internal textures in the imprint. This is achieved at an imprinting energy of UVV: 2500-3000 mJ / cm². 2 A clear inner texture rubbing effect can be achieved within a time limit of 3 seconds.

[0049] The combination of the water-based UV-curable polyurethane resin and the initiator selected in this invention results in a coating of this invention having a UV curing energy of 250±50 mJ / cm² under a secondary mercury lamp. 2 Under these conditions, the coating not only dries rapidly but also achieves excellent interlayer adhesion with the topcoat UV protective layer. Furthermore, adhesion tests under high temperature and high humidity conditions (85℃*8H or 65℃ / 90% relative humidity 504H) show excellent adhesion, reaching a rating of at least 4B. These characteristics make this waterborne UV-curable polyurethane resin ideal for use in printing coatings, providing excellent coating performance and durability.

[0050] According to one embodiment of the present invention, the ratio of the trifunctionality of the waterborne UV-curable polyurethane resin II to that of the waterborne UV-curable polyurethane resin is 6-7:3-4, and both are silicone-modified polyurethane resins.

[0051] According to one embodiment of the present invention, the waterborne UV-curable polyurethane resin includes at least one of UA-2502 and UA-2396 from Jieshida. Its composition is a hexafunctional silicone-modified polyurethane resin. Because the contained silicone segments can synergistically crosslink with the anti-scratch additive of the present invention to form a dense three-dimensional silicone network structure on the coating surface, the smoothness of the coating is greatly improved, the coefficient of friction is reduced, and the scratch resistance is enhanced. In the roller test, the test object hardly stops when it collides with the protective layer, quickly sliding away, significantly reducing the contact time between the test object and the UV protective layer of the printing coating, thereby avoiding scratches and effectively preventing scratches caused by metal, plastic, and other materials in daily use from affecting the appearance.

[0052] Furthermore, the waterborne UV-curable polyurethane resin II, which combines six functionalities with organosilicon segments, can, under the synergistic effect of photoinitiator I and photoinitiator II of the present invention, enable the coating to exhibit excellent toughness and density during vacuum oxygen-isolated polymerization curing, and exhibit a high water droplet angle. The high density enables the coating of the present invention to have excellent water resistance, and can prevent water penetration from affecting the adhesion of the coating.

[0053] Therefore, even if chemicals come into contact with the coating, it will not cause excessive penetration, and moisture cannot permeate through the coating to the bottom and thus damage the coating structure. This ensures that when highly corrosive substances such as oleic acid and triethanolamine are dropped onto the coating of this invention, the coating will not produce bubbles or peel off, and will maintain excellent adhesion (≥4B). This also means that, in terms of water resistance testing, after undergoing boiling in water at 85°C for 8 hours or high temperature and humidity testing at 65°C / 90% relative humidity for 504 hours, the primer and topcoat work synergistically to prevent moisture penetration and maintain stable adhesion (≥4B).

[0054] According to one embodiment of the present invention, the waterborne UV-curable polyurethane resin includes at least one of UA-2412 and UA-2413 from Jieshida. Its composition is a 3-4 functionality silicone-modified polyurethane resin. In this invention, the waterborne UV-curable polyurethane resin, photoinitiator one, and photoinitiator two work together to enable the coating of the present invention to exhibit excellent flexibility, density, and a high water droplet angle during vacuum-isolated oxygen-inhibited polymerization curing. Therefore, when chemicals come into contact with the coating, the coating shrinks and clumps without spreading or penetrating. The primer and topcoat work synergistically to effectively prevent moisture from damaging the coating. When highly corrosive oleic acid or triethanolamine is added to the coating, it does not cause bubbles or peeling, and the adhesion test maintains ≥4B. In terms of water resistance testing, whether it is boiling at 85℃ for 8 hours or high temperature and high humidity at 65℃ / 90% relative humidity for 504 hours, the primer and topcoat still work synergistically to prevent moisture penetration, and the adhesion remains stable at ≥4B. Furthermore, due to its low functionality and superior flexibility, the coating can be bent up to 180° without cracking.

[0055] The waterborne UV-curable polyurethane resin III, when used in conjunction with the waterborne UV-curable polyurethane II of the present invention, can achieve a balance between flexibility and toughness.

[0056] According to one embodiment of the present invention, the photoinitiator includes at least one of 1-hydroxycyclohexane-phenyl ketone and 2-hydroxy-2-methyl-phenylacetone-1.

[0057] According to one embodiment of the present invention, the photoinitiator used in the present invention includes photoinitiator one and photoinitiator two. Photoinitiator one is 1-hydroxycyclohexane-phenyl ketone, which is co-cured with the aqueous UV-curable polyurethane resin of the present invention. During the printing process, an LED energy (UVV) of 2500-3000 mJ / cm is used. 2 Good surface drying effect can be achieved in 3 seconds, completing the printing process without affecting production efficiency, without reducing the life of silicone mold, and maintaining the clarity of the texture inside the printing; the photoinitiator is 2-hydroxy-2-methyl-phenylacetone-1, which is used for secondary curing after printing to further accelerate the surface drying and hard drying process to achieve the best performance of the coating.

[0058] According to one embodiment of the present invention, the waterborne modified hydroxyl acrylic polyurethane includes at least one of WPU2503 and WPU2402 from Huigu Chemical, with a solid mass ratio of 30-40%, an organic solvent content of <2%, and the remainder being water.

[0059] The use of the water-based modified hydroxyl acrylic polyurethane ensures that the coating of this invention can easily achieve the ideal film thickness during application, while also being extremely low in VOCs and very environmentally friendly. The water-based modified hydroxyl acrylic polyurethane, with hydroxyl acrylic groups grafted onto its main polyurethane structure, possesses excellent pigment orientation, exhibiting a very good alignment effect for aluminum silver paste and pearlescent powder, resulting in a strong metallic visual texture. Furthermore, because the main structure is polyurethane, the coating of this invention possesses excellent bending resistance and flexibility; bending at 90°C will not cause the coating to crack, and the interlayer adhesion is even stronger when combined with a UV intermediate coating texture layer.

[0060] According to one embodiment of the present invention, the waterborne modified hydroxyl acrylic polyurethane has a hydroxyl content of 1-1.6%. This component provides excellent flexibility in the coating. When it undergoes a crosslinking reaction with component B of the present invention, a specific three-dimensional network structure is formed, which can maintain a certain degree of toughness without reducing the overall hardness of the coating, while also maintaining excellent flexibility, and will not crack during bending tests; it also has the ability to resist the shrinkage of the intermediate UV texture layer. The base coat uses waterborne modified hydroxyl acrylic polyurethane raw material with a hydroxyl content of 1-1.6%. After being combined with the intermediate UV texture layer and the top UV protective layer of the present invention, the coating maintains its flexibility. When bent at 45° or under high temperature and humidity conditions of 65°C / 90%, the coating will not crack after 504 hours, demonstrating that the coating has excellent flexibility in high temperature and humidity environments.

[0061] According to one embodiment of the present invention, the water-dispersible isocyanate curing agent comprises Wanhua Chemical's... 269. At least one of 268. Its type is based on hexamethylene diisocyanate modified curing agent.

[0062] According to one embodiment of the present invention, the isocyanate curing agent has an isocyanate content of 18-20% by mass. This curing agent is chosen based on its optimized crosslinking reaction with the waterborne modified hydroxyl acrylic polyurethane of the present invention's base coating. This crosslinking reaction forms a denser and more interwoven network structure, significantly improving the coating's performance, including water resistance, chemical resistance, and flexibility. This structural optimization not only enhances the coating's density but also enables it to more effectively resist moisture and chemical attack while maintaining sufficient flexibility to withstand various environmental stresses and physical damage that the coating may encounter during use. By optimizing the isocyanate content of the water-dispersible isocyanate curing agent, the present invention ensures superior performance of the coating in various application scenarios.

[0063] According to one embodiment of the present invention, the weight ratio of the second waterborne UV-curable polyurethane resin and the third waterborne UV-curable polyurethane resin is 40-60:40-60. This ratio enables the coating of the present invention to achieve a hardness of 500g4H, while also meeting the performance requirements of not cracking after bending at 45° and not cracking after 168 hours of high temperature and high humidity at 65°C / 90%. The combination of the primer and topcoat allows the coating to still exhibit stable water resistance and maintain adhesion ≥4B in tests of boiling at 85°C for 8 hours or high temperature and high humidity at 65°C / 90% for 504 hours. Similarly, in tests of oleic acid and triethanolamine resistance without bubbling or peeling, the coating also achieves adhesion ≥4B.

[0064] According to one embodiment of the present invention, the additive one includes at least one of matting powder, defoamer, substrate wetting agent one, rheology modifier one, rheology modifier two, and cosolvent one.

[0065] According to one embodiment of the present invention, the matting agent includes at least one of E-1011 or E-220A from Tosoh Corporation. The main component of these matting agents is precipitated silica, which has low oil absorption and low thixotropy, and has no significant impact on the arrangement and texture of the aluminum silver paste and pearlescent powder. Their average particle size is 1.2-2.3 μm, which is extremely small and highly transparent, and does not significantly affect the color effect transparency of the color paste, aluminum silver paste, and pearlescent powder, effectively showcasing the color effect of the base coating.

[0066] According to one embodiment of the present invention, the defoamer includes at least one of BYK-022 from BYK Chemical and Foamex 810 from Evonik. The aqueous defoamer of the present invention uses a polyether polysiloxane polymer, maintaining the thixotropic nature of the system; therefore, when formulating metallic-effect coatings, no blackening or other defects in the coating visual effect will occur. Furthermore, this defoamer has excellent suppression effects on the dispersion of matting agents and the microbubbles generated during coating application and construction, both during coating preparation and subsequent use.

[0067] According to one embodiment of the present invention, the substrate wetting agent includes at least one of BYK-3455 and BYK-3456 from BYK Chemical and LE7 from Yueyang Kaimen. These components are mainly polyether-modified polydimethylsiloxane, which can significantly reduce static and dynamic surface tension, improve the wetting ability of the base coating to the substrate and the leveling of the wet film. In addition, they excellently exhibit the color effect of pigments and help the effect pigments to align on the coating surface, thereby improving the overall texture of the coating.

[0068] According to one embodiment of the present invention, the rheology modifier includes Wanhua Chemical's... At least one of U605 and BYK Chemical's RHEOBYK-H 7625VF. These components are primarily highly efficient pseudoplastic nonionic polyurethane thickeners, which significantly enhance the thixotropy and leveling properties of the system in the coatings of this invention, contributing to the orderly arrangement of effect pigments and thus improving the texture of the coating. Simultaneously, they significantly improve anti-sagging properties during application, effectively preventing the frame effect that may occur during coating application, thereby preventing blackening and mottling of effect pigments.

[0069] According to one embodiment of the present invention, the rheology modifier II includes at least one of Desparon's AQ-633E and AQ-630, the main component of which is modified polyamide wax amine salt. These rheology modifiers help to disperse effect pigments well in the coating and avoid hard sedimentation of effect pigments. In addition, during the application process, they can promote the directional alignment of effect pigments, further improving the overall texture of the coating.

[0070] According to one embodiment of the present invention, the co-solvent includes at least one selected from dipropylene glycol methyl ether, diethylene glycol butyl ether, and dipropylene glycol methyl ether. These co-solvents are characterized by high boiling points and low evaporation rates, while exhibiting good miscibility with water. Their application in coatings helps to form a dense coating and significantly slows down the drying rate of the coating at room temperature, thereby improving the performance of the coating in practical applications. The selection and use of co-solvents not only helps to improve the coating performance of the coating but also provides more working time during application, allowing the coating to better demonstrate its application advantages.

[0071] According to one embodiment of the present invention, component B further includes a second cosolvent, wherein the second cosolvent is propylene glycol diacetate. This cosolvent has the characteristics of low odor and low volatility, which helps to improve the environmental performance of the coating. At the same time, it can effectively extend the activation period of the base coat of the water-based printing coating, giving the coating a longer usable time during application. This choice of cosolvent not only helps to improve the application characteristics of the coating, but also ensures that the coating remains in good condition during application, thereby improving the coating effect and durability of the base coat.

[0072] According to one embodiment of the present invention, the auxiliary agent three includes an anti-scratch agent, which includes acrylate-modified polysiloxane.

[0073] According to one embodiment of the present invention, the third additive includes a substrate wetting agent and a scratch-resistant additive.

[0074] According to one embodiment of the present invention, the substrate wetting agent II includes at least one of Evonik Chemical's Tego Wet 270 and Yueyang Kaimen's LE 64. The main component of these wetting agents is a polyether-modified polysiloxane surfactant, which possesses excellent wetting properties and reduces surface tension. They can achieve excellent wetting and spreading effects in water-based printing coatings, especially at the interface between the UV texture layer and the base layer. This characteristic not only helps maintain the mirror-like leveling effect of the coating surface but also significantly improves the clarity of the internal texture during printing. By using these wetting agents, the overall quality and appearance of the printing coating can be effectively enhanced, ensuring that the applied UV texture layer is evenly distributed on the substrate surface and maintains good surface quality.

[0075] According to one embodiment of the present invention, the anti-scratch additive includes at least one of SN-4922 from Shenzhen Bamboo Chemical Co., Ltd. and TEGO Rad 2200N from Evonik Chemical Co., Ltd. Their main components are acrylate-modified polysiloxanes, which can significantly improve the smoothness of the coating surface and reduce the coefficient of friction. Upon impact, they allow objects to slide away quickly, thereby greatly reducing the contact time between the roller test object and the UV protective layer of the printing coating, thus improving scratch resistance. Furthermore, the acrylate functional groups in SN-4922 and TEGO Rad 2200N can crosslink and fix with the UV protective layer of the water-based printing coating of the present invention on the surface of the printing coating, persistently reducing the coefficient of friction and improving surface smoothness. This design allows the coating to maintain its resistance to roller testing for a long time, effectively avoiding scratches caused by materials such as metal and plastic in daily use, thereby maintaining a beautiful surface.

[0076] Specifically, the technical solution adopted according to the second aspect of the present invention is as follows:

[0077] A water-based printing coating includes a base layer, a mid-coat UV texture layer, and a top-coat UV protective layer, all stacked together. The base layer is made from components A and B of the water-based printing coating. The mid-coat UV texture layer is made from component C of the water-based printing coating. The top-coat UV protective layer is made from component D of the water-based printing coating.

[0078] Specifically, the technical solution adopted according to the third aspect of the present invention is as follows:

[0079] A method for preparing the water-based imprinting coating includes the following steps:

[0080] S1 is mixed with waterborne modified hydroxyl acrylic polyurethane, additive 1 and water to obtain component A. Component A is mixed with water-dispersed isocyanate curing agent and coated on substrate, then dried to obtain base coating.

[0081] S2 is mixed with waterborne UV-curable polyurethane resin I, photoinitiator, additive II and water, and heated to obtain component C. Component C is coated on the surface of the base layer and dried to obtain the intermediate UV texture layer.

[0082] S3 is a mixture of waterborne UV-curable polyurethane resin II, waterborne UV-curable polyurethane resin III, photoinitiator, additive III, and water. After heating, component D is obtained. Component D is coated on the surface of the intermediate UV texture layer and dried to obtain the topcoat UV protective layer. The base layer, intermediate UV texture layer, and topcoat UV protective layer constitute a waterborne imprinting coating.

[0083] Another aspect of the present invention relates to the application of the water-based printing coating in packaging material printing or 3C product decorative printing. This includes the water-based printing coating as described in the first aspect embodiment above. Since this application employs all the technical solutions of the above-described water-based printing coating, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments.

[0084] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Detailed Implementation

[0085] In the description of this invention, the use of terms such as "first," "second," etc., is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or implicitly indicating the order of the technical features indicated.

[0086] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the embodiments, and are only for the purpose of facilitating the description of this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0087] The terms "preferred," "more preferably," etc., used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0088] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0089] 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 the present invention.

[0090] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0091] In the examples and comparative examples, the water-based printing coatings were prepared according to the following steps:

[0092] Preparation steps for component A:

[0093] 1. Disperse the water-based modified hydroxyl acrylic polyurethane at 400 rpm for 2 minutes;

[0094] 2. Add the matting powder to the product obtained in step 1 while stirring at 800 rpm. Gradually increase the stirring speed to 800 rpm as the matting powder is added, disperse for 6 minutes, and stir evenly.

[0095] 3. Add the defoamer to the product obtained in step 2 while stirring at 1000 rpm, disperse for 15 minutes, and stir until homogeneous;

[0096] 4. Add wetting agent one to the product obtained in step 3 at a stirring speed of 600 rpm, disperse for 5 minutes, and stir evenly;

[0097] 5. Add rheology modifier 1 and rheology modifier 2 to the product obtained in step 4 in sequence at a stirring speed of 800 rpm, disperse for 12 minutes, and stir evenly.

[0098] 6. Add cosolvent 1 and deionized water sequentially to the product obtained in step 5 while stirring at 600 rpm, disperse for 6 minutes, and stir evenly to obtain component A.

[0099] Preparation steps for component B:

[0100] 7. Add cosolvent 2 to the water-dispersible isocyanate at a stirring speed of 800 rpm, disperse for 10 minutes, and stir evenly to obtain component B.

[0101] Preparation steps for component C:

[0102] 8. Disperse the water-based UV-curable polyurethane resin at 800 rpm for 3 minutes;

[0103] 9. Add substrate wetting agent II to the product obtained in step 8 at a stirring speed of 800 rpm, disperse for 3 minutes, and stir evenly;

[0104] 10. Heat the photoinitiator at 60°C until it is completely dissolved, cool it to 40°C, and add it to the product obtained in step 9 while stirring at 500 rpm. Disperse for 8 minutes and stir until homogeneous.

[0105] 11. Add deionized water slowly to the product obtained in step 10 while stirring at 500 rpm, disperse for 5 minutes, stir evenly, and obtain component C.

[0106] Preparation steps of component D:

[0107] 12. After mixing the water-based UV-curable polyurethane resin, disperse it for 3 minutes while stirring at 800 rpm.

[0108] 13. Add substrate wetting agent II to the product obtained in step 12 at a stirring speed of 800 rpm, disperse for 3 minutes, and stir evenly;

[0109] 14. Add the anti-scratch additive to the product obtained in step 13 at a stirring speed of 800 rpm, disperse for 5 minutes, and stir evenly;

[0110] 15. Heat the photoinitiator at 60°C until it is completely dissolved, cool it to 40°C, and add it to the mixture in step 14 while stirring at 500 rpm. Disperse for 8 minutes and stir until homogeneous.

[0111] 16. Slowly add deionized water to the product obtained in step 15 while stirring at 500 rpm, disperse for 5 minutes, stir evenly, and obtain component D.

[0112] In the examples and comparative examples, the water-based printing coating is prepared by the following steps:

[0113] S1 mixes the raw materials of component A and component B with deionized water in a mass ratio of 100:10:15, sprays the mixture onto the surface of the epoxy and fiberglass composite substrate, and bakes it at 70°C for 20 minutes to obtain the water-based printing coating base layer.

[0114] S2 mixes the raw material components of component C with deionized water at a ratio of 100:6, sprays the mixture onto the surface of the cooled water-based printing coating base layer, and bakes it at 60°C for 10 minutes. (LED energy UVV: 2800mj / cm²) 2 The inner texture was imprinted under a time of 3 seconds to obtain a water-based imprinting intermediate UV texture layer;

[0115] S3 mixes the raw material components of component D with deionized water at a ratio of 100:2, sprays it onto the above-mentioned water-based printing intermediate UV texture layer, and bakes it at 60°C for 10 minutes. The LED energy UVV is 2800 mJ / cm². 2 The outer texture was imprinted under a time limit of 3 seconds, and then subjected to an energy of 1000 mJ / cm². 2 Light intensity 100mw / cm 2 The above-mentioned water-based printing coating is obtained by secondary curing under mercury lamp UV light under certain conditions.

[0116] Example 1

[0117] A composite water-based printing coating, comprising components A, B, C, and D:

[0118] The raw material components of component A are as follows:

[0119]

[0120] The raw material components of component B are as follows:

[0121]

[0122] The raw material components of component C are as follows:

[0123] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin Wuxing Chemical WU3202 90 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 5.6 total 100 ;

[0124] The raw material components of component D are:

[0125] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin II Jieshida UA-2396 34 Waterborne UV-curable polyurethane resin three Jestar UA-2413 51 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Anti-scratch additives Shenzhu Chemical's SN-4922 4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 6.6 total 100 .

[0126] Example 2

[0127] The difference between Example 2 and Example 1 is that the amounts of waterborne UV-curable polyurethane resin II and waterborne UV-curable polyurethane resin III in component D are different.

[0128] A composite water-based printing coating, comprising components A, B, C, and D:

[0129] The raw material components of component A are as follows:

[0130]

[0131] The raw material components of component B are as follows:

[0132]

[0133] The raw material components of component C are as follows:

[0134]

[0135]

[0136] The raw material components of component D are:

[0137] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin II Jieshida UA-2396 51 Waterborne UV-curable polyurethane resin three Jestar UA-2413 34 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Anti-scratch additives Shenzhu Chemical's SN-4922 4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 6.6 total 100 .

[0138] Example 3

[0139] The difference between Example 3 and Example 1 is that the waterborne modified hydroxyl acrylic polyurethane in component A is different. Specifically, the hydroxyl content of the waterborne modified hydroxyl acrylic polyurethane in Example 1 is 1.0%, while the hydroxyl content of the waterborne modified hydroxyl acrylic polyurethane in Example 3 is 1.8%.

[0140] A composite water-based printing coating, comprising components A, B, C, and D:

[0141] The raw material components of component A are as follows:

[0142]

[0143] The raw material components of component B are as follows:

[0144]

[0145] The raw material components of component C are as follows:

[0146] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin Wuxing Chemical WU3202 90 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 5.6 total 100 ;

[0147] The raw material components of component D are:

[0148] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin II Jieshida UA-2396 34 Waterborne UV-curable polyurethane resin three Jestar UA-2413 51 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Anti-scratch additives Shenzhu Chemical's SN-4922 4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 6.6 total 100 .

[0149] Example 4

[0150] The difference between Example 4 and Example 1 is that the water-dispersible isocyanate in component B is different. Specifically, Example 4 uses a dispersible isocyanate that reacts more slowly with hydroxyl groups to replace the water-dispersible isocyanate in Example 1.

[0151] A composite water-based printing coating, comprising components A, B, C, and D:

[0152] The raw material components of component A are as follows:

[0153]

[0154]

[0155] The raw material components of component B are as follows:

[0156] Preparation of raw materials Manufacturer Number of copies Water-dispersible isocyanates Double bond chemistry DB83100 80 Cosolvent 2 Propylene glycol diacetate 20 total 100 ;

[0157] The raw material components of component C are as follows:

[0158] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin Wuxing Chemical WU3202 90 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 5.6 total 100 ;

[0159] The raw material components of component D are:

[0160] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin II Jieshida UA-2396 34 Waterborne UV-curable polyurethane resin three Jestar UA-2413 51 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Anti-scratch additives Shenzhu Chemical's SN-4922 4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 6.6 total 100 .

[0161] Example 5

[0162] The difference between Example 5 and Example 1 is that the photoinitiators in component C are different. In Example 1, the photoinitiators in component C are photoinitiator one and photoinitiator two; in Example 5, the photoinitiators in component C are photoinitiator one and photoinitiator three.

[0163] A composite water-based printing coating, comprising components A, B, C, and D: wherein the raw material composition of component A is as follows:

[0164]

[0165] The raw material components of component B are as follows:

[0166]

[0167] The raw material components of component C are as follows:

[0168]

[0169] The raw material components of component D are:

[0170]

[0171]

[0172] Comparative Example 1

[0173] The difference between Comparative Example 1 and Example 1 is that in Component A of Comparative Example 1, waterborne hydroxy acrylic acid is used instead of the waterborne modified hydroxy acrylic polyurethane in Example 1.

[0174] A composite water-based printing coating, comprising components A, B, C, and D:

[0175] The raw material components of component A are as follows:

[0176]

[0177] The raw material components of component B are as follows:

[0178]

[0179] The raw material components of component C are as follows:

[0180] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin Wuxing Chemical WU3202 90 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 5.6 total 100 ;

[0181] The raw material components of component D are:

[0182]

[0183]

[0184] Comparative Example 2

[0185] The difference between Comparative Example 2 and Example 1 is that in Component A of Comparative Example 1, waterborne polyurethane is used instead of waterborne modified hydroxyl acrylic polyurethane in Example 1.

[0186] A composite water-based printing coating, comprising components A, B, C, and D:

[0187] The raw material components of component A are as follows:

[0188]

[0189] The raw material components of component B are as follows:

[0190]

[0191] The raw material components of component C are as follows:

[0192]

[0193]

[0194] The raw material components of component D are:

[0195] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin II Jieshida UA-2396 34 Waterborne UV-curable polyurethane resin three Jestar UA-2413 51 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Anti-scratch additives Shenzhu Chemical's SN-4922 4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 6.6 total 100 .

[0196] Comparative Example 3

[0197] The difference between Comparative Example 3 and Example 1 is that in Component B of Comparative Example 3, Waterborne UV-curable polyurethane resin IV (functionality 6) is used instead of Waterborne UV-curable polyurethane resin I (functionality 2) in Example 1.

[0198] A composite water-based printing coating, comprising components A, B, C, and D:

[0199] The raw material components of component A are as follows:

[0200]

[0201] The raw material components of component B are as follows:

[0202]

[0203] The raw material components of component C are as follows:

[0204] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin four Wuxing Chemical WU3601 90 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 5.6 total 100 ;

[0205] The raw material components of component D are:

[0206] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin II Jieshida UA-2396 34 Waterborne UV-curable polyurethane resin three Jestar UA-2413 51 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Anti-scratch additives Shenzhu Chemical's SN-4922 4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 6.6 total 100 .

[0207] Comparative Example 4

[0208] The difference between Comparative Example 4 and Example 1 is that component D in Comparative Example 4 contains only waterborne UV-curable polyurethane resin II and does not contain waterborne UV-curable polyurethane resin III.

[0209] A composite water-based printing coating, comprising components A, B, C, and D:

[0210] The raw material components of component A are as follows:

[0211]

[0212] The raw material components of component B are as follows:

[0213]

[0214] The raw material components of component C are as follows:

[0215] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin Wuxing Chemical WU3202 90 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 5.6 total 100 ;

[0216] The raw material components of component D are:

[0217] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin II Jieshida UA-2396 85 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Anti-scratch additives Shenzhu Chemical's SN-4922 4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 6.6 total 100 .

[0218] Comparative Example 5

[0219] The difference between Comparative Example 5 and Example 1 is that component D in Comparative Example 5 contains only waterborne UV-curable polyurethane resin III and does not contain waterborne UV-curable polyurethane resin II.

[0220] A composite water-based printing coating, comprising components A, B, C, and D:

[0221] The raw material components of component A are as follows:

[0222]

[0223]

[0224] The raw material components of component B are as follows:

[0225]

[0226] The raw material components of component C are as follows:

[0227] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin Wuxing Chemical WU3202 90 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 5.6 total 100 ;

[0228] The raw material components of component D are:

[0229] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin three Jestar UA-2413 85 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Anti-scratch additives Shenzhu Chemical's SN-4922 4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 6.6 total 100 .

[0230] Comparative Example 6

[0231] The difference between Comparative Example 6 and Example 1 is that in Comparative Example 6, waterborne UV-curable polyurethane resin 5 is used instead of waterborne UV-curable polyurethane resin 3 in component D of Example 1.

[0232] A composite water-based printing coating, comprising components A, B, C, and D:

[0233] The raw material components of component A are as follows:

[0234]

[0235]

[0236] The raw material components of component B are as follows:

[0237]

[0238] The raw material components of component C are as follows:

[0239] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin Wuxing Chemical WU3202 90 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 5.6 total 100 ;

[0240] The raw material components of component D are:

[0241] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin II Jieshida UA-2396 34 Waterborne UV-curable polyurethane resin five Zhanxin UC7200 51 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Anti-scratch additives Shenzhu Chemical's SN-4922 4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 6.6 total 100 .

[0242] Comparative Example 7

[0243] The difference between Comparative Example 7 and Example 1 is that in Comparative Example 7, waterborne UV-curable polyurethane resin 5 is used instead of waterborne UV-curable polyurethane resin 2 in component D of Example 1.

[0244] A composite water-based printing coating, comprising components A, B, C, and D:

[0245] The raw material components of component A are as follows:

[0246]

[0247] The raw material components of component B are as follows:

[0248]

[0249] The raw material components of component C are as follows:

[0250] Preparation of raw materials Manufacturer Number of copies Waterborne UV-curable polyurethane resin Wuxing Chemical WU3202 90 Substrate wetting agent 2 Evonik Chemical Tego Wet 270 0.4 Photoinitiator 1 1-Hydroxycyclohexylphenyl ketone 2 Photoinitiator II 2-Hydroxy-2-methyl-phenylacetone-1 2 Deionized water / 5.6 total 100 ;

[0251] The raw material components of component D are:

[0252]

[0253]

[0254] Performance testing:

[0255] The water-based printing coatings prepared in Examples 1-5 and Comparative Examples 1-7 were used to prepare water-based printing coatings. The coatings were tested as follows, and the test results are shown in Table 1.

[0256] Table 1

[0257]

[0258]

[0259] As shown in Table 1, the water-based printing coating of this invention combines flexibility and chemical resistance. It does not crack when bent at 45°C, nor does it crack after 168 hours of high temperature and high humidity at 65°C / 90% conditions, maintaining a hardness of 500g*4H. Simultaneously, it is resistant to oleic acid, and the TEA coating exhibits no bubbles and does not peel off, with an adhesion test result ≥4B. The adhesion remains stable at ≥4B after boiling at 85°C*8H or high temperature and high humidity at 65°C / 90% conditions for 504H. The test tube surface shows no scratches. LED energy UVV: 2800mj / cm². 2 The printing process can be completed in 3 seconds.

[0260] Specifically:

[0261] Compared with Example 3, although Example 3 also uses water-based modified hydroxyl acrylic polyurethane resin, the hydroxyl content is 1.8%, which is higher than that of the water-based modified hydroxyl acrylic polyurethane resin in Example 1. This results in the coating after crosslinking with the isocyanate curing agent of component B being more brittle than that in Example 1. The brittleness is more pronounced in high temperature and high humidity environments. Therefore, the high temperature and high humidity coating maintained at 65°C / 90% for 168 hours will crack and fail to meet the requirements.

[0262] Compared with Example 4, Example 4B component is a dispersible isocyanate that reacts slowly with hydroxyl groups. The density of the coating structure after cross-linking with the base layer component A cannot work well with the intermediate UV texture layer and the top UV protective layer. Therefore, the adhesion of high temperature and high humidity and boiling water resistance tests is 0B, which does not meet the requirements.

[0263] Compared with Comparative Example 1, Example 1 is an aqueous hydroxy acrylic resin. The comparative example does not have polyurethane chain segments with similar high flexibility in structure. The coating after crosslinking with the isocyanate curing agent of component B is more brittle. The coating will crack during bending and high temperature and humidity tests. It cannot work in synergy with the intermediate UV texture layer and the topcoat UV protective layer. Therefore, the adhesion of high temperature and humidity and water boiling resistance tests is 0B, which does not meet the requirements.

[0264] Compared with Comparative Example 2, Example 1 is a waterborne polyurethane resin. The Comparative Example does not have a hydroxyl acrylic chain segment with similar excellent toughness in its structure. The crosslinking reaction with the isocyanate curing agent of component B is insufficient, the hardness is too low and does not meet the requirements. At the same time, the crosslinking density of the coating is not enough and the adhesion in the high temperature and high humidity test and the water boiling resistance test is 0B, which does not meet the requirements.

[0265] Compared with Comparative Example 3, Example 1 uses a high-hardness, six-functionality waterborne UV-curable polyurethane resin. The high functionality of Comparative Example 3 results in rapid curing and high cross-linking density of the coating, which leads to no adhesion of the UV topcoat protective layer. Therefore, the imprinted coating has no interlayer adhesion, bending cracks, high temperature and high humidity cracks, and an adhesion of 0B in the boiling water test. Specifically, in Example 1, the functionality of waterborne UV-curable polyurethane resin II is greater than that of waterborne UV-curable polyurethane resin III, which is greater than that of waterborne UV-curable polyurethane resin I. In Comparative Example 3, the functionality of waterborne UV-curable polyurethane resin II is equal to that of waterborne UV-curable polyurethane resin III, which is greater than that of waterborne UV-curable polyurethane resin I. Since waterborne UV-curable polyurethane resin I is a component of component C (corresponding to the intermediate UV texture layer of the coating), and waterborne UV-curable polyurethane resins II and III are components of component D (corresponding to the topcoat UV protective layer of the coating), in Example 1, with more functional groups in the surface layer (topcoat UV protective layer) resin and fewer functional groups in the intermediate layer (intermediate UV texture layer) resin, it can play a connecting role in chemical crosslinking, enhancing the overall bonding strength of the coating. In summary, due to the different resin functionalities of the intermediate and surface layers in the coating of Example 1, the intermediate layer can react more effectively with the functional groups in the surface layer to form stronger chemical bonds, thereby improving its adhesion. In contrast, the coating of Comparative Example 3, due to its similar functionality, could not effectively form a similar cross-linked structure, resulting in relatively low adhesion.

[0266] Compared to Example 5, Example 5 used phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide as the photoinitiator. This initiator had weak surface curing ability and insufficient surface drying of the printed coating, resulting in the internal texture of the printed coating not being surface dried, which affected the overall appearance of the coating texture. Specifically, compared to 2-hydroxy-2-methyl-phenylacetone-1 in Example 1, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide lacks active hydroxyl groups and cannot effectively participate in the crosslinking reaction in the UV curing system. Therefore, the curing rate and degree in the coating are affected, which may lead to incomplete curing or a slow curing rate, thus reducing the coating's surface drying performance. On the other hand, the introduction of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide reduces the effective crosslinking reaction active sites in the coating, resulting in a decrease in the coating's curing rate and surface drying performance.

[0267] Compared with Comparative Example 4, Example 1 uses a single waterborne UV-curable polyurethane resin II. The single waterborne UV-curable polyurethane resin II has excessively high toughness, which leads to bending cracking of the printed coating and cracking during high temperature and high humidity testing.

[0268] Compared with Comparative Example 5, Example 1 uses a single water-based UV-curable polyurethane resin III. The single water-based UV-curable polyurethane resin III has too high flexibility, resulting in insufficient toughness of the imprinted coating and failure to meet the hardness standard. The coating surface will show obvious scratches during roller testing.

[0269] Compared with Comparative Example 6, Example 1 is a combination of waterborne UV-curable polyurethane resin II and waterborne UV-curable polyurethane resin V. Waterborne UV-curable polyurethane resin V is a flexible resin without silicone segments. After being combined in the preferred ratio, the silicone segments are insufficient, resulting in insufficient anti-pollution and penetration performance against chemicals. Therefore, the adhesion after resistance to oleic acid and triethanolamine is 0B. At the same time, the coating has insufficient scratch resistance, resulting in slight scratches on the surface during roller testing.

[0270] Compared with Comparative Example 7, Example 1 was a combination of waterborne UV-curable polyurethane resin III and waterborne UV-curable polyurethane resin V. Waterborne UV-curable polyurethane resin V is a flexible resin without silicone segments. After being combined in the preferred ratio, the silicone segments were insufficient and the flexible resin content was too high. This resulted in insufficient resistance to chemical contamination and penetration, and insufficient toughness of the coating. Therefore, the hardness did not meet the standard requirements, and the adhesion after resistance to oleic acid and triethanolamine was 0B. At the same time, the coating's scratch resistance was insufficient, resulting in slight scratches on the surface during roller testing.

[0271] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A composite aqueous blotting coating, characterized by: The raw materials of the water-based overprint coating include the following components by weight: A component: auxiliary agent one, water and 60-80 parts of water-based modified hydroxyl acrylic polyurethane; B component: 70-90 parts of water-dispersed isocyanate curing agent; C component: auxiliary agent two, water, 85-90 parts of water-based ultraviolet curing polyurethane resin one, 2-6 parts of photoinitiator; D component: auxiliary agent three, water, 35-55 parts of water-based ultraviolet curing polyurethane resin two, 35-55 parts of water-based ultraviolet curing polyurethane resin three, 2-6 parts of photoinitiator; Both the water-based ultraviolet curing polyurethane resin two and the water-based ultraviolet curing polyurethane resin three are organic silicon modified polyurethane resins, the functionality of the water-based ultraviolet curing polyurethane resin one is 2, the functionality of the water-based ultraviolet curing polyurethane resin two is 6, and the functionality of the water-based ultraviolet curing polyurethane resin three is 3-4; The hydroxyl content of the water-based modified hydroxyl acrylic polyurethane is 1-1.6%, and the mass percentage content of isocyanate of the water-dispersed isocyanate curing agent is 18-20%.

2. A composite aqueous blotting coating according to claim 1, characterized in that: The auxiliary agent three includes a scratch-resistant auxiliary agent, and the scratch-resistant auxiliary agent includes an acrylate modified polysiloxane.

3. A composite aqueous blotting coating according to claim 1, characterized in that: The photoinitiator includes at least one of 1-hydroxycyclohexyl-phenyl ketone and 2-hydroxy-2-methyl-phenylpropanone-1.

4. An aqueous blotting coating characterized by: The coating includes a bottom coating layer, a middle coating UV texture layer and a top coating UV protective layer arranged in layers, the raw materials of the bottom coating layer include the A component and the B component of the water-based overprint coating according to any one of claims 1 to 3, the raw materials of the middle coating UV texture layer include the C component of the water-based overprint coating according to any one of claims 1 to 3, and the raw materials of the top coating UV protective layer include the D component of the water-based overprint coating according to any one of claims 1 to 3.

5. A method of preparing an aqueous blotting coating as claimed in claim 4, characterized in that: The coating includes the following steps: S1: mixing the water-based modified hydroxyl acrylic polyurethane, the auxiliary agent one and the water to obtain component A, mixing the component A and the water-dispersed isocyanate curing agent, coating on a substrate, drying to obtain a bottom coating layer; S2: mixing the water-based ultraviolet curing polyurethane resin one, the photoinitiator, the auxiliary agent two and the water, heating to obtain component C, coating the component C on the surface of the bottom coating layer, drying to obtain a middle coating UV texture layer; S3: mixing the water-based ultraviolet curing polyurethane resin two, the water-based ultraviolet curing polyurethane resin three, the photoinitiator, the auxiliary agent three and the water, heating to obtain component D, coating the component D on the surface of the middle coating UV texture layer, drying to obtain a top coating UV protective layer.

6. Application of the composite water-based overprint coating according to any one of claims 1 to 3 in packaging material printing, label printing or 3C product decorative printing.

Images