Wear-resistant uv bright light protective coating for electrochemical aluminum foil and preparation method thereof

Abstract

The application provides a wear-resistant UV bright protective coating for electrochemical aluminum foil and a preparation method thereof. The coating comprises the following raw materials in parts by weight: 40-50 parts of polyurethane acrylate resin, 15-25 parts of fluorine-modified acrylic resin, 20-30 parts of active diluent, 5-15 parts of inorganic filler, 2-7 parts of photoinitiator, 2-5 parts of silane coupling agent, 1-3 parts of leveling agent and 1-3 parts of antioxidant. The coating has good wear resistance, scratch resistance, temperature resistance, gloss and weather resistance when used, can be used as a protective layer of electrochemical aluminum foil, improves the durability of the product, and can also be applied to the ink protective layer of IMD decorative film to improve the high temperature resistance of the product. The preparation method of the coating is stable in process, easy to control, high in production efficiency and beneficial to industrialized production.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a wear-resistant UV glossy protective coating for electroplated aluminum foil and its preparation method. Background Technology

[0002] Electroplated aluminum foil, as a commonly used decorative film material, has been widely used in packaging printing, home appliances, 3C electronic products, anti-counterfeiting labels, and ID cards due to its advantages such as good appearance, decorative properties, resistance to fading, and durability. Electroplated aluminum foil can be divided into electroplated aluminum hot stamping foil and electroplated aluminum composite foil. Electroplated aluminum hot stamping foil typically includes a multi-layer structure consisting of a base film layer, a release layer, a color layer, an aluminum plating layer, and an adhesive layer arranged sequentially. Its manufacturing process usually involves coating the base film layer with release coating and color coating, followed by vacuum aluminum plating, then coating with adhesive, and finally rewinding the finished product. Electroplated aluminum composite foil, on the other hand, does not contain a release layer. The base film layer, serving as the carrier of the electroplated aluminum foil structure, is typically made of films such as PET or BOPP. After hot stamping, the base film layer is removed; during the lamination process, it is retained. The release layer allows the color layer, aluminum plating layer, etc., to be easily separated from the base film during hot stamping. The color layer and aluminum plating layer provide the color and pattern effects required for the electroplated aluminum foil. The aluminum plating layer provides the main metallic luster effect. The adhesive layer mainly serves a transfer or lamination function.

[0003] However, the color layer and aluminum plating layer of electroplated aluminum foil are easily scratched, worn, or oxidized during production and subsequent processing, affecting their performance. A protective coating is often required to improve their durability. However, existing protective coatings often struggle to simultaneously achieve wear resistance, scratch resistance, temperature resistance, and weather resistance, impacting product lifespan. Therefore, this paper proposes a UV-curable protective coating. When preparing electroplated aluminum hot stamping foil, this UV protective coating can be applied after the release layer, followed by the color layer coating. This effectively protects the color layer and aluminum plating layer after transfer, improving product durability and performance, which is of significant importance. Furthermore, this UV protective coating can also be applied to electroplated aluminum composite foil and IMD decorative film. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art by providing a wear-resistant UV glossy protective coating for electroplated aluminum foil and its preparation method. This coating exhibits excellent wear resistance, scratch resistance, gloss, and weather resistance, and can be used as a protective layer for electroplated aluminum foil, improving its durability and performance. The preparation method of this thin-film coating is stable, easy to control, and has high production efficiency, meeting the needs of industrial production.

[0005] The objective of this invention is achieved through the following technical solution: A wear-resistant UV glossy protective coating for electroplated aluminum foil, comprising the following raw materials in parts by weight: 40-50 parts of polyurethane acrylate resin, 15-25 parts of fluorine-modified acrylic resin, 20-30 parts of reactive diluent, 5-15 parts of inorganic filler, 2-7 parts of photoinitiator, 2-5 parts of silane coupling agent, 1-3 parts of antioxidant, and 1-3 parts of leveling agent.

[0006] Furthermore, the preparation method of the polyurethane acrylate resin includes the following steps:

[0007] A1. Under nitrogen protection, add polyol to the reaction vessel and heat it. Add polyisocyanate dropwise so that the molar ratio of -OH of polyol to -NCO of polyisocyanate is 1:1.7-2.1. After the dropwise addition is complete, add catalyst. Stop the reaction when the measured -NCO reaches 1.1-1.2 times the theoretical residual value of the initial feed, and obtain mixture A.

[0008] A2. Cool mixture A, add polymerization inhibitor and solvent, and dropwise add hydroxyl-containing acrylate monomers so that the molar ratio of -OH to the remaining -NCO groups in mixture A is 1:1-1.15. After the addition is complete, heat the mixture and react until the residual -NCO content is ≤0.1%.

[0009] A3. Cool the reaction system to room temperature to obtain polyurethane acrylate resin.

[0010] Furthermore, in step A1, the polyisocyanate is isophorone diisocyanate and hexamethylene diisocyanate.

[0011] Furthermore, in step A1, the polyol is at least one of polycarbonate diol and poly(1,4-butanediol adipate).

[0012] Furthermore, in step A1, the catalyst is at least one of an organotin catalyst and an organobismuth catalyst.

[0013] Furthermore, in step A2, the polymerization inhibitor is at least one of hydroquinone, p-hydroxyanisole, and 2,6-di-tert-butyl-p-cresol.

[0014] Furthermore, in step A2, the solvent is at least one of acetone, butanone, ethyl acetate, and butyl acetate.

[0015] Furthermore, in step A2, the hydroxyl-containing acrylate monomer is at least one of hydroxyethyl acrylate (HEA), hydroxypropyl acrylate (HPA), hydroxydodecyl acrylate (HDA), hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate (HPMA), and hydroxydecyl methacrylate.

[0016] The polyurethane acrylate resin prepared by this invention achieves good compatibility with raw materials such as fluorinated modified acrylic resin and reactive diluent, ensuring coating uniformity and film-forming properties. It also works synergistically with inorganic fillers, fluorinated modified acrylic resin and other raw materials to improve the scratch resistance and abrasion resistance of the coating, while taking into account good flexibility, thereby improving the performance of the product and extending its service life.

[0017] Furthermore, the preparation method of the fluorinated modified acrylic resin includes the following steps:

[0018] B1. Under nitrogen protection, methyl methacrylate, isooctyl acrylate, hydroxyethyl methacrylate, hexafluorobutyl methacrylate, γ-methacryloyloxypropyltrimethoxysilane, methacrylic acid, and poly(1,4-butanediol adipate) diol are added to a solvent; then an initiator and dodecyl mercaptan are added and mixed thoroughly to obtain a premixed solution for later use; separately, the initiator and solvent are added to a reaction vessel, the temperature is raised to 80-90℃, and the premixed solution is added dropwise;

[0019] B2. After the premixed liquid is added, the reaction is carried out at a constant temperature. The initiator and solvent are added, the temperature is raised to 95-105℃, and after the reaction is completed, the temperature is lowered to below 40℃. The product is then discharged to obtain fluorinated modified acrylic resin.

[0020] The present invention prepares fluorinated acrylic resin by means of the above method, which helps to improve the weather resistance and solvent wiping resistance of the coating and can impart better gloss. The fluorinated acrylic resin can achieve good compatibility and synergistic effect with raw materials such as polyurethane acrylate resin and silane coupling agent to improve the overall performance of the protective coating.

[0021] Furthermore, the active diluent is at least one of isobornyl acrylate, caprolactone acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and pentaerythritol triacrylate.

[0022] Furthermore, the inorganic filler is at least one of nano-silica, nano-alumina, and nano-titanium dioxide.

[0023] Furthermore, the photoinitiator is at least one selected from 2,4,6-trimethylbenzoyl diphenylphosphine oxide, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, and 1-hydroxycyclohexylphenyl ketone.

[0024] Furthermore, the silane coupling agent is at least one selected from γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

[0025] Furthermore, the antioxidant is at least one of hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

[0026] Furthermore, the leveling agent is at least one of the following: silicone polyether, acrylate, and fluorocarbon compounds.

[0027] This invention also provides a method for preparing a wear-resistant UV gloss protective coating for electroplated aluminum foil, comprising the following steps:

[0028] (1) Mix polyurethane acrylate resin and fluorinated acrylic resin, heat and stir evenly; then add inorganic filler, silane coupling agent, antioxidant and leveling agent and mix evenly to obtain material one;

[0029] (2) Add reactive diluent and photoinitiator to material 1 and mix evenly to obtain wear-resistant UV glossy protective coating for electroplated aluminum foil.

[0030] The wear-resistant UV glossy protective coating for electroplated aluminum foil of the present invention can be used in several ways: (i) when preparing electroplated aluminum hot stamping foil, the UV protective coating is applied between the release layer and the color layer. After the electroplated aluminum foil hot stamping process is completed and the base film is removed, the protective layer is located on the outermost layer; (ii) after the electroplated aluminum hot stamping foil has been normally hot stamped on the substrate, the UV protective coating is then applied to the surface of the substrate, and the protective layer is also located on the outermost layer; (iii) when preparing electroplated aluminum composite foil, the UV protective coating is applied between the base film and the color layer, and after lamination, it becomes an intermediate interlayer. In all three of the above ways of use, the wear-resistant UV glossy protective coating can effectively protect the color layer, the aluminum plating layer, and the substrate or patch, improving the product's durability and practicality.

[0031] The beneficial effects of this invention are as follows: The wear-resistant UV-gloss protective coating for electroplated aluminum foil of this invention is formulated by compounding polyurethane acrylate resin, fluorinated modified acrylic resin, reactive diluent, inorganic filler, and other raw materials. These raw materials achieve good synergistic effects, resulting in a coating with excellent wear resistance, scratch resistance, temperature resistance, gloss, and weather resistance during use. This coating can be used as a protective layer for electroplated aluminum foil, improving product durability; it can also be applied to the ink protective layer of IMD decorative films, improving the product's high-temperature resistance. The preparation method of the wear-resistant UV-gloss protective coating for electroplated aluminum foil of this invention is stable, easy to control, and has high production efficiency, which is conducive to industrial production. Detailed Implementation

[0032] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0033] In some embodiments of the present invention, a wear-resistant UV glossy protective coating for electroplated aluminum foil comprises the following raw materials in parts by weight: 40-50 parts of polyurethane acrylate resin, 15-25 parts of fluorine-modified acrylic resin, 20-30 parts of reactive diluent, 5-15 parts of inorganic filler, 2-7 parts of photoinitiator, 2-5 parts of silane coupling agent, 1-3 parts of antioxidant, and 1-3 parts of leveling agent.

[0034] In some embodiments of the present invention, the method for preparing the polyurethane acrylate resin includes the following steps:

[0035] A1. Under nitrogen protection, add 40-50 parts of polyol to the reaction vessel, heat to 50-60℃, and add polyisocyanate dropwise. The amount of polyisocyanate added should be such that the molar ratio of -OH of polyol to -NCO of polyisocyanate is 1:1.8-2.1. The dropwise addition time is 30-90 min. After the dropwise addition is complete, add 0.01-0.1 parts of catalyst, heat to 70-75℃, and keep the reaction at this temperature for 2-3 h. Determine the -NCO content using the di-n-butylamine method. Stop the reaction when the measured -NCO reaches 1.1-1.2 times the theoretical residual value of the initial feed, and obtain mixture A.

[0036] A2. Cool mixture A to 40-50℃, add 0.05-0.2 parts of polymerization inhibitor and 30-60 parts of solvent, stir for 10-30 min, then slowly add hydroxyl-containing acrylate monomers dropwise. The amount of hydroxyl-containing acrylate monomers added should be such that the molar ratio of -OH to the remaining -NCO groups in mixture A is 1.0-1.15:1, and the dropwise addition time is 30-90 min. After the dropwise addition is complete, raise the temperature to 60-70℃ and react until the residual -NCO content is ≤0.1%.

[0037] A3. Cool the reaction system to room temperature to obtain polyurethane acrylate resin.

[0038] In some embodiments of the present invention, in step A1, the polyisocyanate is at least one of isophorone diisocyanate and hexamethylene diisocyanate.

[0039] In some embodiments of the present invention, in step A1, the polyol is at least one of polycarbonate diol and poly(1,4-butanediol adipate).

[0040] In some embodiments of the present invention, in step A2, the polymerization inhibitor is at least one of hydroquinone, p-hydroxyanisole, and 2,6-di-tert-butyl-p-cresol.

[0041] In some embodiments of the present invention, in step A2, the hydroxyl-containing acrylate monomer is at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxydodecyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxydecyl methacrylate.

[0042] In some embodiments of the present invention, the preparation method of the fluorinated modified acrylic resin includes the following steps:

[0043] B1. Under nitrogen protection, methyl methacrylate, isooctyl acrylate, hydroxyethyl methacrylate, hexafluorobutyl methacrylate, γ-methacryloyloxypropyltrimethoxysilane, methacrylic acid, and poly(1,4-butanediol adipate) diol are added to a solvent; then an initiator and dodecyl mercaptan are added and mixed thoroughly to obtain a premixed solution for later use; separately, the initiator and solvent are added to a reaction vessel, heated, and then the premixed solution is added dropwise.

[0044] B2. After the premixed liquid is added, the reaction is carried out at a constant temperature. The initiator and solvent are added, and the temperature is raised to continue the reaction. After the reaction is completed, the temperature is lowered to below 40°C, and the material is discharged to obtain fluorinated modified acrylic resin.

[0045] In some embodiments of the present invention, the preparation method of the fluorinated modified acrylic resin includes the following steps:

[0046] B1. Under nitrogen protection, add 30-40 parts of methyl methacrylate, 20-30 parts of isooctyl acrylate, 3-8 parts of hydroxyethyl methacrylate, 10-20 parts of hexafluorobutyl methacrylate, 2-6 parts of γ-methacryloyloxypropyltrimethoxysilane, 1-3 parts of methacrylic acid, and 4-8 parts of poly(1,4-butanediol adipate) to 60-80 parts of solvent; then add 0.3-0.6 parts of initiator and 0.1-0.5 parts of dodecyl mercaptan, mix well to obtain a premixed solution, and set aside for use; separately add 0.2-0.5 parts of initiator and 10-20 parts of solvent to the reaction vessel, heat to 80-90℃, and dropwise add the premixed solution over a period of 60-120 minutes;

[0047] B2. After the premixed liquid is added, react for 2.5-3.5 h; add 0.2-0.5 parts of initiator and 20-30 parts of solvent, heat to 95-105℃, react for 90-150 min, cool to below 40℃, and discharge to obtain fluorinated modified acrylic resin.

[0048] In some embodiments of the present invention, in steps B1 and B2, the initiator is at least one of benzoyl peroxide, ammonium persulfate, and potassium persulfate; and the solvent is at least one of butyl acetate and propylene glycol methyl ether acetate.

[0049] In some embodiments of the present invention, the solvent is composed of butyl acetate and propylene glycol methyl ether acetate in a mass ratio of 3-4:1-2.

[0050] In some embodiments of the present invention, the reactive diluent is at least one of isobornyl acrylate, caprolactone acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and pentaerythritol triacrylate.

[0051] In some embodiments of the present invention, the inorganic filler is at least one of nano-silica, nano-alumina and nano-titanium dioxide, with a particle size of 30-80 nm.

[0052] In some embodiments of the present invention, the photoinitiator is at least one selected from 2,4,6-trimethylbenzoyl diphenylphosphine oxide, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, and 1-hydroxycyclohexylphenyl ketone.

[0053] In some embodiments of the present invention, the silane coupling agent is at least one selected from γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

[0054] In some embodiments of the present invention, the antioxidant is at least one of hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

[0055] In some embodiments of the present invention, the leveling agent is at least one of organosilicon polyethers, acrylates, and fluorocarbon compounds.

[0056] In some embodiments of the present invention, a method for preparing a wear-resistant UV glossy protective coating for electroplated aluminum foil includes the following steps:

[0057] (1) Mix polyurethane acrylate resin and fluorinated acrylic resin, heat to 60-70℃, and stir at 300-600 rpm for 10-40 min; then add inorganic filler, silane coupling agent, antioxidant and leveling agent, and stir at 600-1200 rpm for 20-60 min to obtain material one.

[0058] (2) Add reactive diluent and photoinitiator to material 1 and mix evenly. Stir at 300-600 rpm for 20-60 min, and then perform vacuum degassing under -0.06 ~ -0.095 MPa conditions to obtain wear-resistant UV glossy protective coating for electroplated aluminum foil.

[0059] Example 1

[0060] In this embodiment, a wear-resistant UV glossy protective coating for electroplated aluminum foil comprises the following raw materials in parts by weight: 45 parts polyurethane acrylate resin, 20 parts fluorine-modified acrylic resin, 25 parts reactive diluent, 10 parts inorganic filler, 5 parts photoinitiator, 3 parts silane coupling agent, 1.5 parts antioxidant, and 2 parts leveling agent.

[0061] Furthermore, the preparation method of the polyurethane acrylate resin includes the following steps:

[0062] A1. Under nitrogen protection, add 45 parts of polyol to a reaction vessel, heat to 55℃, and add polyisocyanate dropwise, so that the molar ratio of -OH of polyol to -NCO of polyisocyanate is 1:1.9, with a dropwise addition time of 60 min. After the dropwise addition is complete, add 0.05 parts of dibutyltin dilaurate, and heat to 72℃. Determine the -NCO content using the di-n-butylamine method. Stop the reaction when the measured -NCO reaches 1.1 times the theoretical residual value of the initial feed, and obtain mixture A.

[0063] A2. Cool mixture A to 45°C, add 0.1 parts of polymerization inhibitor and 40 parts of solvent propylene glycol methyl ether acetate, stir for 20 min, then slowly add hydroxyethyl acrylate dropwise, so that the molar ratio of -OH to the remaining -NCO groups in mixture A is 1.05:1, and the dropwise addition time is 60 min. After the dropwise addition is complete, raise the temperature to 65°C and react until the residual -NCO content is ≤0.1%.

[0064] A3. Cool the reaction system to room temperature to obtain polyurethane acrylate resin.

[0065] Further, in step A1, the polyisocyanate is composed of isophorone diisocyanate and hexamethylene diisocyanate in a weight ratio of 4:1; the polyol is composed of polycarbonate diol (molecular weight 2000) and poly(1,4-butanediol adipate) diol (molecular weight 1000) in a weight ratio of 3:2. The isophorone diisocyanate is WANNATE® IPDI from Wanhua Chemical. The poly(1,4-butanediol adipate) diol has a molecular weight of 2000 and is HY-2022 from Jining Tangyi Chemical. The polycarbonate diol has a molecular weight of 1000 and is HK-B10 from Shandong Moore Chemical.

[0066] Furthermore, in step A2, the polymerization inhibitor is p-hydroxyanisole; the hydroxyl-containing acrylate monomer is hydroxyethyl acrylate.

[0067] Furthermore, the preparation method of the fluorinated modified acrylic resin includes the following steps:

[0068] B1. Under nitrogen protection, 35 parts of methyl methacrylate, 25 parts of isooctyl acrylate, 5 parts of hydroxyethyl methacrylate, 16 parts of hexafluorobutyl methacrylate, 4 parts of γ-methacryloyloxypropyltrimethoxysilane, 2 parts of methacrylic acid, and 6 parts of poly(1,4-butanediol adipate) diol were added to 70 parts of solvent; then 0.4 parts of initiator and 0.2 parts of dodecyl mercaptan were added and mixed evenly to obtain a premixed solution for later use; separately, 0.3 parts of initiator and 10 parts of solvent were added to the reaction vessel, the temperature was raised to 85°C, and the premixed solution was added dropwise at a uniform rate for 120 min; the initiator was benzoyl peroxide, and the solvent was composed of butyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3; the molecular weight of poly(1,4-butanediol adipate) diol was 2000.

[0069] B2. After the premixed liquid is added, react for 3 hours; add 0.3 parts of initiator and 10 parts of solvent, heat to 95℃, react for 120 minutes, cool to below 40℃, and discharge to obtain fluorinated modified acrylic resin.

[0070] Furthermore, the reactive diluent is composed of isoborneol acrylate, 1,6-hexanediol diacrylate, and pentaerythritol triacrylate in a weight ratio of 3:1:1.

[0071] Furthermore, the inorganic filler is composed of nano-silica and nano-alumina in a mass ratio of 2:1, with a particle size of 30-80 nm.

[0072] Furthermore, the photoinitiator is composed of 2,4,6-trimethylbenzoyldiphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a mass ratio of 1:1.

[0073] Furthermore, the silane coupling agent is γ-methacryloyloxypropyltrimethoxysilane.

[0074] Furthermore, the antioxidant is composed of antioxidant 1010 and antioxidant 168 in a mass ratio of 2:1; the leveling agent is BYK-333.

[0075] In this embodiment, a method for preparing a wear-resistant UV glossy protective coating for electroplated aluminum foil includes the following steps:

[0076] (1) Mix polyurethane acrylate resin and fluorinated acrylic resin, heat to 65°C, and stir at 500 rpm for 20 min; then add inorganic filler, silane coupling agent, antioxidant and leveling agent, and stir at 1000 rpm for 30 min to obtain material one.

[0077] (2) Add reactive diluent and photoinitiator to material 1 and mix evenly. Stir at 500 rpm for 30 min and then perform vacuum degassing under -0.09 MPa conditions to obtain wear-resistant UV glossy protective coating for electroplated aluminum foil.

[0078] Example 2

[0079] In this embodiment, a wear-resistant UV glossy protective coating for electroplated aluminum foil comprises the following raw materials in parts by weight: 40 parts of polyurethane acrylate resin, 25 parts of fluorine-modified acrylic resin, 25 parts of reactive diluent, 12 parts of inorganic filler, 5 parts of photoinitiator, 4 parts of silane coupling agent, 1.5 parts of antioxidant, and 2 parts of leveling agent.

[0080] Furthermore, the preparation method of the polyurethane acrylate resin includes the following steps:

[0081] A1. Under nitrogen protection, add 45 parts of polyol to a reaction vessel, heat to 55°C, and add polyisocyanate dropwise, so that the molar ratio of -OH of polyol to -NCO of polyisocyanate is 1:1.9, with a dropwise addition time of 60 min. After the dropwise addition is complete, add 0.05 parts of dibutyltin dilaurate, and heat to 70°C. Determine the -NCO content using the di-n-butylamine method. Stop the reaction when the measured -NCO reaches 1.1 times the theoretical residual value of the initial feed, and obtain mixture A.

[0082] A2. Cool mixture A to 40°C, add 0.1 parts of polymerization inhibitor and 40 parts of solvent propylene glycol methyl ether acetate, stir for 20 min, then slowly add hydroxyethyl acrylate dropwise, so that the molar ratio of -OH to the remaining -NCO groups in mixture A is 1.05:1, and the dropwise addition time is 60 min. After the dropwise addition is complete, raise the temperature to 60°C and react until the residual -NCO content is ≤0.1%.

[0083] A3. Cool the reaction system to room temperature to obtain polyurethane acrylate resin.

[0084] Furthermore, in step A1, the polyisocyanate is composed of isophorone diisocyanate and hexamethylene diisocyanate in a weight ratio of 4:1; the polyol is composed of polycarbonate diol (molecular weight 2000) and poly(1,4-butanediol adipate) diol (molecular weight 1000) in a weight ratio of 3:2.

[0085] Furthermore, in step A2, the polymerization inhibitor is p-hydroxyanisole; the hydroxyl-containing acrylate monomer is hydroxyethyl acrylate.

[0086] Furthermore, the preparation method of the fluorinated modified acrylic resin includes the following steps:

[0087] B1. Under nitrogen protection, 35 parts of methyl methacrylate, 25 parts of isooctyl acrylate, 5 parts of hydroxyethyl methacrylate, 16 parts of hexafluorobutyl methacrylate, 4 parts of γ-methacryloyloxypropyltrimethoxysilane, 2 parts of methacrylic acid, and 6 parts of poly(1,4-butanediol adipate) diol were added to 70 parts of solvent; then 0.4 parts of initiator and 0.2 parts of dodecyl mercaptan were added and mixed evenly to obtain a premixed solution for later use; separately, 0.3 parts of initiator and 10 parts of solvent were added to the reaction vessel, the temperature was raised to 85°C, and the premixed solution was added dropwise at a uniform rate for 120 min; the initiator was benzoyl peroxide, and the solvent was composed of butyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3;

[0088] B2. After the premixed liquid is added, react for 3 hours; add 0.3 parts of initiator and 10 parts of solvent, heat to 95℃, react for 120 minutes, cool to below 40℃, and discharge to obtain fluorinated modified acrylic resin.

[0089] Furthermore, the inorganic filler is nano-silica with a particle size of 30-80 nm. The silane coupling agent is γ-methacryloyloxypropyltrimethoxysilane.

[0090] In this embodiment, a method for preparing a wear-resistant UV glossy protective coating for electroplated aluminum foil includes the following steps:

[0091] (1) Mix polyurethane acrylate resin and fluorinated acrylic resin, heat to 60°C, and stir at 400 rpm for 30 min; then add inorganic filler, silane coupling agent, antioxidant and leveling agent, and stir at 1200 rpm for 20 min to obtain material one;

[0092] (2) Add reactive diluent and photoinitiator to material 1 and mix evenly. Stir at 400 rpm for 30 min and then perform vacuum degassing under -0.085 MPa conditions to obtain wear-resistant UV glossy protective coating for electroplated aluminum foil.

[0093] The rest of the content of this embodiment is the same as that of Embodiment 1, and will not be repeated here.

[0094] Example 3

[0095] In this embodiment, a wear-resistant UV glossy protective coating for electroplated aluminum foil comprises the following raw materials in parts by weight: 50 parts polyurethane acrylate resin, 15 parts fluorine-modified acrylic resin, 25 parts reactive diluent, 8 parts inorganic filler, 5 parts photoinitiator, 3 parts silane coupling agent, 1.5 parts antioxidant, and 2 parts leveling agent.

[0096] Furthermore, the preparation method of the polyurethane acrylate resin includes the following steps:

[0097] A1. Under nitrogen protection, add 45 parts of polyol to a reaction vessel, heat to 55℃, and add polyisocyanate dropwise, so that the molar ratio of -OH of polyol to -NCO of polyisocyanate is 1:1.9, with a dropwise addition time of 60 min. After the dropwise addition is complete, add 0.05 parts of dibutyltin dilaurate, and heat to 72℃. Determine the -NCO content using the di-n-butylamine method. Stop the reaction when the measured -NCO reaches 1.1 times the theoretical residual value of the initial feed, and obtain mixture A.

[0098] A2. Cool mixture A to 45°C, add 0.1 parts of polymerization inhibitor and 40 parts of solvent propylene glycol methyl ether acetate, stir for 20 min, then slowly add hydroxyethyl acrylate dropwise, so that the molar ratio of -OH to the remaining -NCO groups in mixture A is 1.05:1, and the dropwise addition time is 60 min. After the dropwise addition is complete, raise the temperature to 65°C and react until the residual -NCO content is ≤0.1%.

[0099] A3. Cool the reaction system to room temperature to obtain polyurethane acrylate resin.

[0100] Furthermore, the preparation method of the fluorinated modified acrylic resin includes the following steps:

[0101] B1. Under nitrogen protection, 35 parts of methyl methacrylate, 25 parts of isooctyl acrylate, 5 parts of hydroxyethyl methacrylate, 16 parts of hexafluorobutyl methacrylate, 4 parts of γ-methacryloyloxypropyltrimethoxysilane, 2 parts of methacrylic acid, and 6 parts of poly(1,4-butanediol adipate) diol were added to 70 parts of solvent; then 0.4 parts of initiator and 0.2 parts of dodecyl mercaptan were added and mixed evenly to obtain a premixed solution for later use; separately, 0.3 parts of initiator and 10 parts of solvent were added to the reaction vessel, the temperature was raised to 85°C, and the premixed solution was added dropwise at a uniform rate for 120 min; the initiator was benzoyl peroxide, and the solvent was composed of butyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3;

[0102] B2. After the premixed liquid is added, react for 3 hours; add 0.3 parts of initiator and 10 parts of solvent, heat to 95℃, react for 120 minutes, cool to below 40℃, and discharge to obtain fluorinated modified acrylic resin.

[0103] Furthermore, the reactive diluent is composed of isoborneol acrylate, 1,6-hexanediol diacrylate, and pentaerythritol triacrylate in a weight ratio of 3:1:1.

[0104] Furthermore, the inorganic filler is composed of nano-silica and nano-alumina in a mass ratio of 2:1, with a particle size of 30-80 nm.

[0105] Furthermore, the silane coupling agent is composed of γ-methacryloxypropyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane in a weight ratio of 2:1.

[0106] In this embodiment, a method for preparing a wear-resistant UV glossy protective coating for electroplated aluminum foil includes the following steps:

[0107] (1) Mix polyurethane acrylate resin and fluorinated acrylic resin, heat to 65°C, and stir at 500 rpm for 20 min; then add inorganic filler, silane coupling agent, antioxidant and leveling agent, and stir at 1000 rpm for 30 min to obtain material one.

[0108] (2) Add reactive diluent and photoinitiator to material 1 and mix evenly. Stir at 500 rpm for 30 min and then perform vacuum degassing under -0.09 MPa conditions to obtain wear-resistant UV glossy protective coating for electroplated aluminum foil.

[0109] The rest of the content of this embodiment is the same as that of Embodiment 1, and will not be repeated here.

[0110] Comparative Example 1

[0111] The difference between this comparative example and Example 1 is that the wear-resistant UV glossy protective coating for the electroplated aluminum foil in this comparative example does not contain fluorine-modified acrylic resin, but is replaced by an equal weight of polyurethane acrylate resin.

[0112] Comparative Example 2

[0113] The difference between this comparative example and Example 1 is that the wear-resistant UV glossy protective coating for electroplated aluminum foil in this comparative example comprises the following raw materials in parts by weight: 45 parts polyurethane acrylate resin, 20 parts fluorine-modified acrylic resin, 25 parts reactive diluent, 10 parts inorganic filler, 5 parts photoinitiator, 3 parts silane coupling agent, 1.5 parts leveling agent, and 2 parts antioxidant. The acrylic resin used is EBECRYL 8110 acrylic resin from Zhanxin.

[0114] The abrasion-resistant UV gloss protective coatings prepared in Examples 1-3 and Comparative Examples 1-2 were coated on a 20 μm PET substrate film with a dry coating amount of 2.0 g / m. 2 The coated wet film was pre-cured in an oven at 80℃ for 2 minutes, and then subjected to a strength of 500 mW / cm². 2 The sample was irradiated with ultraviolet light for 30 seconds and then placed at 23℃ and 50%RH for 24 hours to obtain the test sample. The performance of the sample was then tested, and the test results are shown in Table 1 below:

[0115]

[0116] Among them, the wear resistance was determined in accordance with GB / T 1768-2006. The sample was set as a circular disc with a diameter of 100 mm. A CS-10 grinding wheel was used with a load of 1000 g and a rotation of 500 rpm. The mass loss (mg) was measured and the results were recorded in Table 1.

[0117] The adhesion test was conducted as follows: The sample was set as a rectangular piece of 150×150mm. The surface coating was adhered with 3M 600 tape and quickly peeled off at a 90° vertical angle. The peeling area was considered qualified if it was not greater than 5%, and unqualified if it was greater than 5%. 100 samples were tested for each example and comparative example. 5 or fewer unqualified samples were classified as A, 15 or fewer unqualified samples as B, and more than 15 unqualified samples as C. The test results were recorded in Table 1.

[0118] The water resistance test was conducted using the following method: the sample was soaked in deionized water at 23°C for 24 hours, and the adhesion was tested. The results were recorded in Table 1.

[0119] The gloss was tested according to GB / T 9754-2007 (60°).

[0120] The weather resistance test was conducted using the following method: the sample was exposed to an ultraviolet lamp at a wavelength of 340 nm with an irradiance of 0.76 W / m². 2 The coating was treated under the irradiation conditions for 200 hours, and the gloss retention rate of the coating after irradiation was tested. The test results are recorded in Table 1.

[0121] The ethanol wiping resistance test was conducted using the following method: a cotton ball soaked in 95% ethanol was used to wipe the coating back and forth 100 times under a pressure of 500g. The test effect was observed, and the results were recorded in Table 1. "No change" means that the coating had no scratches, wrinkles, or discoloration; "slight wrinkling and peeling" means that wrinkles and peeling occurred on the surface covering ≤5% of the area. The samples from Examples 1-3 and Comparative Examples 1-2 were bent 180° with a shaft diameter of 1mm, and no cracks or peeling were observed.

[0122] The test results show that the wear-resistant UV glossy protective coatings for electroplated aluminum foil in Examples 1-3 have excellent wear resistance, scratch resistance and weather resistance compared to Comparative Examples 1-2, while also having good gloss. They can be used as a protective layer for electroplated aluminum foil, improving product durability and making them highly practical.

[0123] The specific embodiments described above are further illustrations of the technical solution and beneficial effects of the present invention, and are not intended to limit the implementation methods. For those skilled in the art, any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A wear-resistant UV-gloss protective coating for electroplated aluminum foil, characterized in that, The raw materials include the following parts by weight: 40-50 parts polyurethane acrylate resin, 15-25 parts fluorinated acrylic resin, 20-30 parts reactive diluent, 5-15 parts inorganic filler, 2-7 parts photoinitiator, 2-5 parts silane coupling agent, 1-3 parts antioxidant, and 1-3 parts leveling agent; the preparation method of the fluorinated acrylic resin includes the following steps: B1. Under nitrogen protection, methyl methacrylate, isooctyl acrylate, hydroxyethyl methacrylate, hexafluorobutyl methacrylate, γ-methacryloyloxypropyltrimethoxysilane, methacrylic acid, and poly(1,4-butanediol adipate) diol are added to a solvent; then an initiator and dodecyl mercaptan are added and mixed thoroughly to obtain a premixed solution for later use; separately, the initiator and solvent are added to a reaction vessel, the temperature is raised to 80-90℃, and the premixed solution is added dropwise; B2. After the premixed liquid is added, the reaction is carried out at a constant temperature. The initiator and solvent are added, the temperature is raised to 95-105℃, and after the reaction is completed, the temperature is lowered to below 40℃. The product is then discharged to obtain fluorinated modified acrylic resin.

2. The wear-resistant UV-gloss protective coating for electroplated aluminum foil according to claim 1, characterized in that, The preparation method of the polyurethane acrylate resin includes the following steps: A1. Under nitrogen protection, add polyol to the reaction vessel and heat it. Add polyisocyanate dropwise so that the molar ratio of -OH of polyol to -NCO of polyisocyanate is 1:1.7-2.

1. After the dropwise addition is complete, add catalyst. Stop the reaction when the measured -NCO reaches 1.1-1.2 times the theoretical residual value of the initial feed, and obtain mixture A. A2. Cool mixture A, add polymerization inhibitor and solvent, and dropwise add hydroxyl-containing acrylate monomers so that the molar ratio of -OH to the remaining -NCO groups in mixture A is 1:1-1.

15. After the addition is complete, heat the mixture and react until the residual -NCO content is ≤0.1%. A3. Cool the reaction system to room temperature to obtain polyurethane acrylate resin.

3. The wear-resistant UV-gloss protective coating for electroplated aluminum foil according to claim 2, characterized in that: In step A2, the hydroxyl-containing acrylate monomer is at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxydodecyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxydecyl methacrylate.

4. The wear-resistant UV-gloss protective coating for electroplated aluminum foil according to claim 1, characterized in that: The active diluent is at least one of isobornyl acrylate, caprolactone acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and pentaerythritol triacrylate.

5. The wear-resistant UV-gloss protective coating for electroplated aluminum foil according to claim 1, characterized in that: The inorganic filler is at least one of nano-silica, nano-alumina, and nano-titanium dioxide.

6. The wear-resistant UV glossy protective coating for electroplated aluminum foil according to claim 1, characterized in that: The photoinitiator is at least one selected from 2,4,6-trimethylbenzoyl diphenylphosphine oxide, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, and 1-hydroxycyclohexylphenyl ketone.

7. The wear-resistant UV glossy protective coating for electroplated aluminum foil according to claim 1, characterized in that: The silane coupling agent is at least one selected from γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

8. The wear-resistant UV gloss protective coating for electroplated aluminum foil according to claim 1, characterized in that: The antioxidant is at least one of hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

9. The wear-resistant UV-gloss protective coating for electroplated aluminum foil according to claim 1, characterized in that: The leveling agent is at least one of the following: silicone polyether, acrylate, and fluorocarbon compounds.

10. The method for preparing the wear-resistant UV gloss protective coating for electroplated aluminum foil according to any one of claims 1-9, characterized in that: Includes the following steps: (1) Mix polyurethane acrylate resin and fluorinated acrylic resin, heat and stir evenly; then add inorganic filler, silane coupling agent, antioxidant and leveling agent and mix evenly to obtain material one; (2) Add reactive diluent and photoinitiator to material 1 and mix evenly to obtain wear-resistant UV glossy protective coating for electroplated aluminum foil.

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