Uv curable inks for aluminum foil materials, method of preparation and use thereof

Abstract

The embodiment of the present application provides a UV curing ink for aluminum foil material, a preparation method and application thereof, and belongs to the technical field of coating compositions.The UV curing ink comprises the following components in parts by weight: a composite photoinitiator, 4-7 parts; a special prepolymer resin, 40-55 parts; an aliphatic polyurethane acrylate resin, 19-34 parts; an organic solvent, 5-10 parts; a monomer diluent, 11-20 parts; an adhesion promoter, 2-4 parts; and a matting powder, 5-10 parts; wherein the special prepolymer resin and the aliphatic polyurethane acrylate resin have double functional groups, the adhesion promoter has a double bond functional group, and the UV curing ink has a dense crosslinking network structure after low-energy UV curing.The UV curing ink of the present application has an adhesion of 5B and is resistant to bending, dichloromethane corrosion and swelling.

Description

Technical Field

[0001] This invention relates to the technical field of coating compositions, and particularly to a UV-curable ink for aluminum foil materials, its preparation method, and its application. Background Technology

[0002] Aluminum foil is widely used in packaging, electronics, energy, construction, and medical fields due to its excellent barrier properties, heat resistance, conductivity, and flexibility. In the packaging industry, aluminum foil is commonly used for packaging food, pharmaceuticals, and daily chemical products, requiring barrier properties for preservation and high-temperature resistance. In the electronics and new energy fields, aluminum foil is used in lithium battery current collectors, solid-state batteries, capacitors, and electromagnetic shielding materials. In the construction and industrial sectors, aluminum foil serves as a reflective film, heat exchanger, and label decoration material. In the medical and special applications, aluminum foil is used in medical dressings and aerospace materials.

[0003] In the surface treatment of aluminum foil materials, a layer of matte or glossy varnish is usually applied to protect the aluminum foil from oxidation, acid and alkali corrosion, and solvent erosion. For example, in cable sheathing, the aluminum foil coating not only provides electromagnetic shielding but also serves a decorative function. Existing aluminum foil inks mainly include solvent-based and water-based inks. These inks evaporate the solvent through thermosetting and rely on reactive groups (such as hydroxyl and amino groups) in the ink to cross-link with the curing agent to form a coating.

[0004] However, these two-component curable inks have the following inherent defects: (1) Slow solvent evaporation: Due to the non-absorbency of aluminum foil, the solvent evaporation rate is slow, resulting in low production efficiency. (2) Poor chemical resistance: When in contact with acids, alkalis, organic solvents (such as greases and paint removers) or inorganic solvents, the coating is prone to peeling, swelling or penetration. (3) Insufficient adhesion: UV curable inks have poor direct adhesion to aluminum foil, and usually require corona treatment, coating or chemical treatment of aluminum foil, which increases cost and production complexity. (4) Not resistant to dichloromethane: Dichloromethane, the main solvent in paint removers, easily causes the coating to swell and peel off, which cannot meet the high solvent resistance requirements. (5) Existing UV curable inks often use high functional group resins, resulting in a large shrinkage rate of the coating after curing, which does not match the low shrinkage rate of aluminum foil, further weakening the adhesion.

[0005] In view of this, a novel UV-curable ink for aluminum foil materials, its preparation method, and its application are proposed to solve all or part of the above problems. Summary of the Invention

[0006] To address at least one of the aforementioned problems and deficiencies in the prior art, embodiments of the present invention provide a novel UV-curable ink for aluminum foil materials, its preparation method, and its application. By introducing a low-functionality (dual-functionality) resin and an adhesion promoter with double-bonded functional groups, the ink coating forms a stable chemical bond with the aluminum foil material on the surface, possessing a dense three-dimensional cross-linked structure internally. This results in excellent adhesion and resistance to bending and dichloromethane corrosion and swelling. The technical solution is as follows:

[0007] According to one aspect of the present invention, a UV-curable ink for aluminum foil materials is provided. The UV-curable ink comprises the following components in parts by weight:

[0008] Composite photoinitiator, 4-7 parts;

[0009] Special prepolymer resin, 40-55 parts;

[0010] Aliphatic polyurethane acrylate resin, 19-34 parts;

[0011] Organic solvent, 5-10 parts;

[0012] Monomer diluent, 11-20 parts;

[0013] Adhesion promoter, 2-4 parts;

[0014] Matte powder, 5-10 parts;

[0015] Among them, the special prepolymer resin and aliphatic polyurethane acrylate resin have bifunctional groups, the adhesion promoter has double bond functional groups, and the UV-cured ink is cured with low energy (preferably 300-600 mJ / cm). 2 After UV curing, it has a dense cross-linked network structure.

[0016] In some embodiments, the composite photoinitiator specifically includes any two or more blends of the following: pyrolysis-type 184 photoinitiator, TPO photoinitiator, hydrogen-abstracting BP photoinitiator, IHT-PI 910 photoinitiator, and 1173 photoinitiator.

[0017] In some embodiments, preferably, the composite photoinitiator is a blend of a pyrolytic 184 photoinitiator, a hydrogen-abstracting BP photoinitiator, and a TPO photoinitiator. The pyrolytic 184 photoinitiator comprises 0.5-1.5 parts by weight, the hydrogen-abstracting BP photoinitiator comprises 3-5 parts, and the TPO photoinitiator comprises 0.2-1.2 parts.

[0018] In some embodiments, specifically, the special prepolymer resin is any one or any combination of epoxy-modified acrylate, polyester-modified acrylate, and polyurethane-modified acrylate.

[0019] In some embodiments, preferably, the aliphatic polyurethane acrylate resin includes 8216 aliphatic polyurethane resin and 8122 aliphatic polyurethane resin. The 8216 aliphatic polyurethane resin is present in 15-25 parts by weight, and the 8122 aliphatic polyurethane resin is present in 4-9 parts by weight.

[0020] In some embodiments, specifically, the monomer diluent has low functional groups to increase the probability of double bond collisions in the resin. The monomer diluent includes any one or any combination thereof of isobornyl acrylate-IBOA, dicyclopentenyl acrylate-DCPA, hydroxyethyl methacrylate-HEMA, dipropylene glycol diacrylate-DPGDA, or similar products.

[0021] In some embodiments, preferably, the monomer diluent is isobornyl acrylate-IBOA and hydroxyethyl methacrylate-HEMA, wherein, by weight, isobornyl acrylate-IBOA is 5-10 parts and hydroxyethyl methacrylate-HEMA is 6-10 parts.

[0022] In some embodiments, specifically, the adhesion promoter is a phosphate ester promoter with double bond functional groups, which introduces phosphate ester groups into the UV-curable ink and establishes a synergistic adhesion effect with special prepolymer resins and aliphatic polyurethane acrylate resins.

[0023] According to another aspect of the present invention, a method for preparing a UV-curable ink for aluminum foil materials is provided. This method is used to prepare the UV-curable ink described above. The preparation method specifically includes the following steps:

[0024] Mix the composite photoinitiator, monomer diluent, and organic solvent, and stir at a speed of 400-600 r / min until the composite photoinitiator is completely dissolved.

[0025] Add the special prepolymer resin and aliphatic polyurethane acrylate resin, and stir and disperse at a speed of 600-800 r / min for 10-20 min.

[0026] Add matting powder, stir and disperse at 400-600 r / min for 10-20 min, then grind in a sand mill and filter with a 300 mesh filter cloth;

[0027] Add an adhesion promoter and stir and disperse at a speed of 400-600 r / min for 5-10 min to obtain UV-curable ink;

[0028] The UV-curable ink was uniformly coated onto the aluminum foil using a 10μm wire rod, resulting in a wet film thickness of 5-8μm. The curing energy was 300-600mJ / cm². 2 A matte ink coating is obtained after curing.

[0029] According to another aspect of the present invention, an application of a UV-curable ink on aluminum foil materials is provided. The UV-curable ink is the UV-curable ink described in the foregoing aspects or a UV-curable ink prepared by the preparation methods described in the foregoing aspects.

[0030] In some embodiments, UV-curable ink is coated onto the surface of aluminum foil and cured by UV to form a matte ink coating. The wet film thickness of this matte ink coating is 5-8 μm, the adhesion reaches 5B, the bending resistance is greater than 100 times, and it is resistant to dichloromethane immersion.

[0031] The UV-curable inks, preparation methods, and applications for aluminum foil materials provided in the embodiments of the present invention have at least one or a portion of the following advantages:

[0032] (1) By introducing low-functional group resins (such as special prepolymer resins with bifunctional groups and aliphatic polyurethane acrylates) and phosphate ester adhesion promoters with double bond functional groups, the ink coating forms a stable chemical bond with the aluminum foil surface, thereby obtaining excellent adhesion (reaching 5B in the cross-cut adhesion test).

[0033] (2) Through the synergistic effect of low functional group resin system and monofunctional group monomer, the ink coating is made more flexible and can withstand more than 100 bending cycles without cracking or peeling, showing excellent flexibility and bending resistance.

[0034] (3) By optimizing the ratio of composite photoinitiator system (such as using a combination of 184, BP and TPO) and low functional group monomers, a dense three-dimensional cross-linked network structure is formed, which effectively resists the swelling and corrosion of dichloromethane and achieves excellent dichloromethane immersion performance.

[0035] (4) The UV curing energy during the preparation process is low, only 300-600 mJ / cm. 2 It falls within the low energy range, effectively saving energy and suitable for high-speed production processes;

[0036] (5) Low-energy UV light curing is used to further improve the curing reaction speed. No long-term heat curing is required. Combined with fast-drying solvents (such as ethyl acetate), it can be quickly cured after coating on the aluminum foil material, thereby improving the overall production efficiency.

[0037] (6) By using low-viscosity monomers (such as IBOA and HEMA), the surface tension of the ink system can be effectively reduced, the leveling and wetting properties of the ink on aluminum foil materials can be improved, and the ink adhesion can be further enhanced.

[0038] (7) Basic adhesion is provided by special prepolymer resin (such as 9213), while aliphatic polyurethane resin (such as 8216 and 8122) is combined to enhance solvent resistance and flexibility, and monomer diluent is used to adjust the reactivity and crosslinking density, thus forming a synergistic mechanism to improve the overall performance of ink adhesion. Attached Figure Description

[0039] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:

[0040] Figure 1 Photographs of UV-curable ink coating products according to Embodiment 1 of the present invention;

[0041] Figure 2 Photographs of UV-curable ink coating products according to Comparative Example 1 of the present invention;

[0042] Figure 3 The present invention provides a process flow for a method of preparing UV-curable ink according to an embodiment of the present invention.

[0043] Figure 4 This is a flowchart illustrating the steps of a method for preparing UV-curable ink according to an embodiment of the present invention. Detailed Implementation

[0044] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof.

[0045] The embodiments of the present invention provide a novel UV-curable ink for aluminum foil materials, a preparation method thereof, and its application. By introducing a low-functional group (bifunctional group) resin and an adhesion promoter with double bond functional groups, the ink coating forms a stable chemical bond with the aluminum foil material on the surface and has a dense three-dimensional cross-linked structure inside, thereby obtaining excellent adhesion and resistance to bending and dichloromethane corrosion and swelling.

[0046] The UV-curable ink mainly comprises the following components by weight:

[0047] Composite photoinitiator, 4-7 parts;

[0048] Special prepolymer resin, 40-55 parts;

[0049] Aliphatic polyurethane acrylate resin, 19-34 parts;

[0050] Organic solvent, 5-10 parts;

[0051] Monomer diluent, 11-20 parts;

[0052] Adhesion promoter, 2-4 parts;

[0053] Matte powder, 5-10 parts;

[0054] Among them, the special prepolymer resin and aliphatic polyurethane acrylate resin have bifunctional groups, the adhesion promoter has double bond functional groups, and the UV-curable ink has a dense cross-linked network structure after low-energy UV curing.

[0055] See Figure 1 The image shows a UV-curable ink coating product according to an embodiment (Example 1) of the present invention. Figure 2 This illustrates existing ink coating products for coating aluminum foil materials. (The image shows...) Figure 1 and Figure 2 The comparison shows that when dichloromethane is present on the product surface and the product is soaked for a certain period of time, the ink coating of this embodiment of the invention does not swell or peel off. Figure 2 The ink coating products showed obvious and severe corrosion and swelling.

[0056] In one example, the composite photoinitiator can be any blend of two or more of the following: cleavage-type 184 photoinitiator, TPO photoinitiator, hydrogen-abstracting BP photoinitiator, IHT-PI 910 photoinitiator, and 1173 photoinitiator.

[0057] In one example, the special prepolymer resin may be any one or any combination thereof, such as epoxy-modified acrylate, polyester-modified acrylate, polyurethane-modified acrylate.

[0058] In one example, the aliphatic polyurethane acrylate resin used is 8216 aliphatic polyurethane resin and 8122 aliphatic polyurethane resin.

[0059] In one example, the monomer diluent has low functional groups to increase the probability of double bond collisions in the resin. The monomer diluent can be any one or any combination thereof from isobornyl acrylate-IBOA, dicyclopentenyl acrylate-DCPA, hydroxyethyl methacrylate-HEMA, dipropylene glycol diacrylate-DPGDA, or similar products.

[0060] In one example, the adhesion promoter is preferably a phosphate ester promoter with double bond functional groups, which introduces phosphate ester groups into the UV-curable ink and establishes a synergistic adhesion effect with special prepolymer resins and aliphatic polyurethane acrylate resins.

[0061] See Figure 3The present invention illustrates a process flow for preparing a UV-curable ink for aluminum foil materials according to an embodiment of the present invention.

[0062] See Figure 4 This shows, as Figure 3 The specific steps of the preparation process shown are as follows. This preparation method specifically includes the following steps:

[0063] Step S100: Mix the composite photoinitiator, monomer diluent and organic solvent, and stir at a speed of 400-600 r / min until the composite photoinitiator is completely dissolved.

[0064] Preferably, ethyl acetate is used as the organic solvent. After mixing, the mixture is placed on a high-speed mixer for stirring and dispersion. The absence of visible particles indicates that the composite photoinitiator has been completely dissolved.

[0065] Step S200: Add the special prepolymer resin and aliphatic polyurethane acrylate resin, and stir and disperse at a speed of 600-800 r / min for 10-20 min.

[0066] Step S300: Add matting powder, stir and disperse at a speed of 400-600 r / min for 10-20 min, then grind in a sand mill and filter using a 300 mesh filter cloth.

[0067] Specifically, after step S200, matting powder (e.g., silica) is added to the mixture. After stirring and dispersing with a high-speed disperser, the mixture is sand-milled 1-3 times. A 300-mesh filter cloth is tied to the outlet of the sand mill for filtration to ensure fineness and remove any particles that may be present.

[0068] Step S400: Add adhesion promoter and stir and disperse at a speed of 400-600 r / min for 5-10 min to obtain UV-curable ink.

[0069] Step S500: Using a 10μm wire rod, uniformly coat the UV-curable ink onto the aluminum foil material, achieving a wet film thickness of 5-8μm, and apply a curing energy of 300-600mJ / cm. 2 A matte ink coating is obtained after curing.

[0070] Among them, UV curing can be achieved by using mercury lamp irradiation, which is faster than thermal curing.

[0071] The present invention will be further described in detail below through several embodiments obtained by adjusting the components and proportions, as well as comparative examples of existing ink and coating products. The preparation methods of each embodiment and comparative example all use the methods described above. Figure 3 and Figure 4 The process flow and its process parameters are shown.

[0072] Example 1

[0073] The UV-curable ink of this embodiment comprises the following components by weight:

[0074] The composite photoinitiator blend includes 1 part of pyrolysis-type 184 photoinitiator, 3.5 parts of hydrogen-abstracting BP photoinitiator, and 0.5 parts of TPO photoinitiator;

[0075] The special prepolymer resin used is 9213 epoxy-modified acrylate, 50 parts;

[0076] The aliphatic polyurethane acrylate resin includes 20 parts of 8216 aliphatic polyurethane resin and 8 parts of 8122 aliphatic polyurethane resin.

[0077] The organic solvent used is 8 parts of ethyl acetate;

[0078] The monomer diluents include 8 parts of isobornyl acrylate-IBOA and 7 parts of hydroxyethyl methacrylate-HEMA;

[0079] Two parts of CD9051 phosphate ester were used as the adhesion promoter;

[0080] The matting agent uses 9 parts of silica.

[0081] The ink and coating products obtained by UV curing are milky white and free of particles, with a fineness of 3μm, a gloss of 8Gs, an adhesion of 5B, and can withstand immersion in carbon tetrachloride (simulated dichloromethane) for more than 30 seconds without swelling or peeling. They can withstand more than 100 flexes without cracking or peeling.

[0082] In one example, the composite photoinitiator blend system exhibits the following synergistic mechanism: the pyrolysis-type 184 photoinitiator primarily absorbs short-to-medium wavelength ultraviolet light (250-330nm), ensuring surface curing; the TPO photoinitiator primarily absorbs long-wave ultraviolet light (350-400nm), possessing strong penetrating power and responsible for deep curing; the hydrogen-absorbing BP photoinitiator, after absorbing ultraviolet light, can easily extract hydrogen atoms from other molecules to generate free radicals, promoting overall initiation efficiency. This composite photoinitiator blend system ensures efficient free radical generation at different wavelengths and coating depths in ink and coating products, achieving simultaneous and thorough surface and deep curing, thereby forming a high-crosslink density network. This is a key process for achieving resistance to dichloromethane swelling.

[0083] In one example, the resin system in the UV-curable ink component also has a synergistic effect. Since the resin system uses low-functional (preferably difunctional) resins, it is key to achieving a performance balance between flexibility and adhesion.

[0084] The polar functional groups (such as carboxyl groups -COOH) in the molecules of special prepolymer resins can form strong chemical bonds (such as -COO) with oxides (such as Al2O3) on the surface of aluminum foil materials. - ...Al + This provides basic adhesion to aluminum foil materials. At the same time, it also has a low shrinkage rate.

[0085] Both 8216 and 8122 aliphatic polyurethane resins offer excellent resistance to dichloromethane and flexibility. 8216 aliphatic polyurethane resin cures quickly, enabling rapid curing at low energy levels; while 8122 aliphatic polyurethane resin further enhances the overall flexibility of the UV-cured ink coating.

[0086] After mixing and dispersion, the special prepolymer resin and the 8216 and 8122 aliphatic polyurethane resins exhibit a synergistic effect: the special prepolymer resin has good adhesion but slightly poor solvent resistance, while the 8216 and 8122 aliphatic polyurethane resins have good solvent resistance but insufficient adhesion. Through the synergistic effect between the low-functional-group substances, the three components balance adhesion and dichloromethane resistance. In other words, the special prepolymer resin provides anchoring, while the 8216 and 8122 aliphatic polyurethane resins construct a swelling-resistant framework, thus jointly forming a strong and dense ink coating.

[0087] In one example, the monomer diluent, being both monofunctional and bifunctional, can also have a synergistic effect with the resin system.

[0088] The isoborneol group structure contained in IBOA acrylate gives it lower viscosity and surface tension. This not only reduces the viscosity of the system, which is beneficial for coating on aluminum foil materials, but more importantly, it makes the ink coating more wettable on the aluminum foil material, thereby promoting adhesion.

[0089] Hydroxyethyl methacrylate (HEMA), as a bifunctional monomer, can increase the probability of double bond collisions and enhance the reactivity of the resin system.

[0090] These monofunctional and / or difunctional monomer diluents complement each other in terms of reactivity and final properties. Isobornyl acrylate-IBOA improves wettability, while hydroxyethyl methacrylate-HEMA increases the reaction rate. When used in combination with low-functionality resin systems, they reduce the viscosity of the resin system and increase the probability of double bond collisions, thus ensuring curing speed while avoiding the increased brittleness and decreased adhesion problems caused by using high-functionality monomers.

[0091] In one example, the mechanism of action of the adhesion promoter can be explained as follows: the phosphate ester (CD9051) with double-bonded functional groups has a strong affinity for metals such as aluminum at one end of its molecule (-PO(OH)2), and can react with oxides on the metal surface to form stable ionic bonds; the double bond at the other end can participate in the UV curing reaction and form covalent bonds with the coating material. This constructs a stable chemical "bridge" between the aluminum foil surface and the ink coating, significantly improving the adhesion between the two, and producing a synergistic adhesion effect with the polar functional groups in the special prepolymer resin.

[0092] Example 2

[0093] In this embodiment, the composite photoinitiator blend includes 1 part of pyrolytic 184 photoinitiator, 2.5 parts of hydrogen abstraction BP photoinitiator (the amount is reduced compared to Example 1), and 0.5 parts of TPO photoinitiator. The base materials and weight proportions of other components remain the same as in Example 1.

[0094] The ink and coating products obtained by UV curing have an adhesion of 5B, but they swell and peel after being soaked in carbon tetrachloride solution for more than 30 seconds.

[0095] Reducing the amount of hydrogen-abstracting BP photoinitiator decreases the efficiency of the composite photoinitiator blend system. This is because sufficient free radicals cannot be generated within a very short time to stimulate double bond breaking and crosslinking, leading to incomplete crosslinking of the resin and monomers, a decrease in crosslinking density, and ultimately, inability to resist swelling by dichloromethane. This demonstrates the significant impact of the composition and amount of the composite photoinitiator on the formation of a dense crosslinked network structure.

[0096] Example 3

[0097] In this embodiment, the monomer diluent includes 5 parts of isobornyl acrylate-IBOA and 10 parts of hydroxyethyl methacrylate-HEMA (the ratio of the two was adjusted and the amount of hydroxyethyl methacrylate-HEMA was appropriately increased compared to Example 1). The base materials and weight parts of other components remain the same as in Example 1.

[0098] The adhesion of ink coatings obtained by UV curing decreases to 3B-4B, and the coating peels off after about 30 flex cycles.

[0099] Increasing the amount of the reactive monomer diluent HEMA (hydroxyethyl methacrylate) further enhances the curing reactivity, but it also leads to an overly vigorous curing reaction. This results in increased brittleness and decreased flexibility of the formed ink coating, consequently deteriorating adhesion and flexural strength. This indicates that the type and amount of monomer diluent need to be precisely balanced to ensure both reactivity and coating mechanical properties.

[0100] Example 4

[0101] In this embodiment, the special prepolymer resin used is 9213 epoxy-modified acrylate, 56 parts, with the amount increased; the aliphatic polyurethane acrylate resin includes 20 parts of 8216 aliphatic polyurethane resin and 2 parts of 8122 aliphatic polyurethane resin (the amount of 8122 is reduced). The base materials and weight parts of other components remain consistent with those in Example 1.

[0102] The ink and coating products obtained by UV curing have an adhesion of 5B, but they swell and peel after being soaked in carbon tetrachloride solution for more than 30 seconds.

[0103] While increasing the amount of 9213 epoxy-modified acrylate theoretically enhances adhesion, its resistance to dichloromethane is relatively poor. Increasing its amount while reducing the amount of 8122 aliphatic polyurethane resin, which has excellent solvent resistance, disrupts the synergistic balance between the resin systems, leading to a decrease in the overall solvent resistance of the ink coating.

[0104] Example 5

[0105] In this embodiment, the special prepolymer resin used is 9213 epoxy-modified acrylate, 45 parts, a reduced amount; the aliphatic polyurethane acrylate resin includes 20 parts of 8216 aliphatic polyurethane resin and 13 parts of 8122 aliphatic polyurethane resin (the amount of 8122 is increased). The base materials and weight parts of other components remain consistent with those in Example 1.

[0106] The adhesion of ink coatings obtained by UV curing decreases to 2B-3B, and the coating peels off after about 20 flexes.

[0107] Increasing the amount of 8122 aliphatic polyurethane resin is equivalent to reducing the proportion of 9213 epoxy-modified acrylate, which provides the basic adhesion. Although the flexibility and solvent resistance of the ink coating may be improved, the relatively insufficient amount of 9213 epoxy-modified acrylate weakens the chemical bonding between it and the aluminum foil material, resulting in a significant decrease in adhesion.

[0108] Example 6

[0109] In this embodiment, no adhesion promoter is added, and the base materials and weight proportions of other components remain the same as in Example 1.

[0110] The adhesion of the ink and coating products obtained by UV curing decreased to 4B, and the coating peeled off after about 50 flex cycles.

[0111] Without the addition of adhesion promoters such as phosphate ester adhesion promoter CD9051, the ink coating and aluminum foil material lack the stable chemical "bridge" provided by the resin system. Relying solely on the polar functional groups of 9213 epoxy-modified acrylate, both adhesion and the flexural strength related to adhesion will decline, demonstrating the crucial role of adhesion promoters in establishing stable adhesion performance.

[0112] Comparative Example 1

[0113] This embodiment uses an existing solvent-based chemical-resistant matte oil product for testing. This product specifically includes the following components by weight:

[0114] Butyl acetate, 20 parts;

[0115] Hydroxyacrylate resin, 43 parts;

[0116] Butyl acetate, 16 parts;

[0117] Polyester polyol resin, 8 parts;

[0118] Matte powder, 6 parts;

[0119] Dibutyltin dilaurate, 0.12 parts;

[0120] Ethyl acetate, 2.4 parts;

[0121] Epoxy phosphate adhesion promoter, 1.5 parts.

[0122] The product in Comparative Example 1 achieved an adhesion of 5B and could withstand more than 100 flexes without cracking, but it swelled and peeled after being soaked in carbon tetrachloride solution for more than 30 seconds.

[0123] Comparative Example 1 uses a thermosetting method, which results in a slower cross-linking speed and a less dense cross-linked structure compared to UV curing. Its low cross-linking density fails to effectively prevent the penetration and swelling of strong solvent molecules such as dichloromethane.

[0124] The product performance parameter test results of the above embodiments and comparative examples are shown in Table 1.

[0125] Table 1 Performance test results of UV inks used for aluminum foil materials

[0126]

[0127] The UV-curable inks obtained in Examples 1-6 above can be used for surface coating of aluminum foil materials, forming a matte ink coating after UV curing. The UV curing process can achieve efficient curing using a low energy supply range, for example, a low curing energy of 300-600 mJ / cm². 2The matte ink coating has a wet film thickness of 5-8μm, an adhesion of 5B (cross-cut adhesion test), a bending resistance of more than 100 times, and can withstand immersion in dichloromethane for more than 30 seconds without swelling or peeling. It is particularly suitable for fields with high requirements for chemical resistance and flexibility, such as high-end electronic shielding materials, cable sheathing, and special packaging.

[0128] The UV-curable inks, preparation methods, and applications for aluminum foil materials provided in the embodiments of the present invention have at least one or a portion of the following advantages:

[0129] (1) By introducing low-functional group resins (such as special prepolymer resins with bifunctional groups and aliphatic polyurethane acrylates) and phosphate ester adhesion promoters with double bond functional groups, the ink coating forms a stable chemical bond with the aluminum foil surface, thereby obtaining excellent adhesion (reaching 5B in the cross-cut adhesion test).

[0130] (2) Through the synergistic effect of low functional group resin system and monofunctional group monomer, the ink coating is made more flexible and can withstand more than 100 bending cycles without cracking or peeling, showing excellent flexibility and bending resistance.

[0131] (3) By optimizing the ratio of composite photoinitiator system (such as using a combination of 184, BP and TPO) and low functional group monomers, a dense three-dimensional cross-linked network structure is formed, which effectively resists the swelling and corrosion of dichloromethane and achieves excellent dichloromethane immersion performance.

[0132] (4) The UV curing energy during the preparation process is low, only 300-600 mJ / cm. 2 It falls within the low energy range, effectively saving energy and suitable for high-speed production processes;

[0133] (5) Low-energy UV light curing is used to further improve the curing reaction speed. No long-term heat curing is required. Combined with fast-drying solvents (such as ethyl acetate), it can be quickly cured after coating on the aluminum foil material, thereby improving the overall production efficiency.

[0134] (6) By using low-viscosity monomers (such as IBOA and HEMA), the surface tension of the ink system can be effectively reduced, the leveling and wetting properties of the ink on aluminum foil materials can be improved, and the ink adhesion can be further enhanced.

[0135] (7) Basic adhesion is provided by special prepolymer resin (such as 9213), while aliphatic polyurethane resin (such as 8216 and 8122) is combined to enhance solvent resistance and flexibility, and monomer diluent is used to adjust the reactivity and crosslinking density, thus forming a synergistic mechanism to improve the overall performance of ink adhesion.

[0136] While some embodiments of the present general inventive concept have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. A UV-curable ink for aluminum foil material, characterized by, The UV curing ink comprises the following components by weight parts: a composite photoinitiator, 4-7 parts; a special prepolymer resin, 40-55 parts; an aliphatic polyurethane acrylate resin, 19-34 parts; an organic solvent, 5-10 parts; a monomer diluent, 11-20 parts; an adhesion promoter, 2-4 parts; a matting powder, 5-10 parts; wherein the composite photoinitiator is a blend of cleavage type 184 photoinitiator, hydrogen abstraction type BP photoinitiator and TPO photoinitiator, the cleavage type 184 photoinitiator is 0.5-1.5 parts by weight, the hydrogen abstraction type BP photoinitiator is 3-5 parts by weight, and the TPO photoinitiator is 0.2-1.2 parts by weight, the special prepolymer resin and the aliphatic polyurethane acrylate resin have dual functional groups, the special prepolymer resin is 9213 epoxy modified acrylate, the adhesion promoter is a phosphate ester promoter with double bond functional groups, the phosphate ester group is introduced into the UV curing ink and establishes a synergistic adhesion effect with the special prepolymer resin and the aliphatic polyurethane acrylate resin, The UV-cured ink has a dense crosslinked network structure after being cured by 300-600 mJ / cm 2 of UV curing energy.

2. The UV curing ink according to claim 1, wherein the aliphatic polyurethane acrylate resin comprises 8216 aliphatic polyurethane resin and 8122 aliphatic polyurethane resin, wherein by weight parts, the 8216 aliphatic polyurethane resin is 15-25 parts, the 8122 aliphatic polyurethane resin is 4-9 parts.

3. The UV curing ink according to claim 1, wherein the monomer diluent has low functional groups to increase the probability of double bond collision of the resin, the monomer diluent comprises any one or any combination of isobornyl acrylate-IBOA, dicyclopentenyl acrylate-DCPA, hydroxyethyl methacrylate-HEMA, and dipropylene glycol diacrylate-DPGDA.

4. The UV curing ink according to claim 3, wherein the monomer diluent is isobornyl acrylate-IBOA and hydroxyethyl methacrylate-HEMA, wherein by weight parts, the isobornyl acrylate-IBOA is 5-10 parts, the hydroxyethyl methacrylate-HEMA is 6-10 parts.

5. A method for the preparation of a UV-curable ink for aluminum foil material, said method for the preparation of a UV-curable ink for aluminum foil material for the preparation of a UV-curable ink according to any one of claims 1-4, characterized in that, The preparation method comprises the following steps: mixing the composite photoinitiator, the monomer diluent and the organic solvent, stirring and dispersing at a speed of 400-600 r / min until the composite photoinitiator is completely dissolved; adding the special prepolymer resin and the aliphatic polyurethane acrylate resin, stirring and dispersing at a speed of 600-800 r / min for 10-20 min; adding the matting powder, after stirring and dispersing at a speed of 400-600 r / min for 10-20 min, sanding with a sand mill and filtering with 300 mesh filter cloth; adding the adhesion promoter, stirring and dispersing at a speed of 400-600 r / min for 5-10 min to obtain the UV curing ink; UV curable inks were uniformly bar coated on aluminum foil material using 10 pm wire bar, wet film thickness 5-8 pm, at curing energy 300-600 mJ / cm 2 The matt ink coating was obtained after curing.

6. Use of the UV-curable ink according to any one of claims 1-4 or the UV-curable ink prepared according to the preparation method of claim 5 on an aluminum foil material, characterized in that, the UV-curable ink is coated on the surface of the aluminum foil, and a matte ink coating is formed after UV curing; the wet film thickness of the matte ink coating is 5-8 μm, the adhesion reaches 5B, the number of bending resistance is greater than 100 times, and the resistance to dichloromethane immersion is achieved.

Images