Wear-resistant UV (ultraviolet) light protective coating for electrochemical aluminum foil and preparation method of wear-resistant UV light protective coating

Abstract

The invention provides a wear-resistant UV (ultraviolet) light protective coating for electrochemical aluminum foil and a preparation method of the wear-resistant UV light protective coating. The coating is prepared from the following raw materials in parts by weight: 40 to 50 parts of polyurethane acrylate resin, 15 to 25 parts of fluorine modified acrylic resin, 20 to 30 parts of reactive diluent, 5 to 15 parts of inorganic filler, 2 to 7 parts of photoinitiator, 2 to 5 parts of silane coupling agent, 1 to 3 parts of flatting agent and 1 to 3 parts of antioxidant. The coating has good wear resistance, scratch resistance, temperature resistance, glossiness and weather resistance during use, can be used as an electrochemical aluminum foil protective layer to improve the durability of a product, and can also be applied to an ink protective layer of an IMD decorative film to improve the high temperature resistance of the product. The preparation method of the coating is stable in process, convenient to control, high in production efficiency and beneficial to industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coating technology, in particular to a wear-resistant UV bright protective coating for electrochemical aluminum foil and a preparation method thereof. BACKGROUND

[0002] As a commonly used decorative film material, electrochemical aluminum foil has been widely used in packaging printing, home appliances, 3C electronic products, anti-counterfeit labels, certificate cards and other fields due to its good appearance effect, good decoration, color fastness and good durability. Electrochemical aluminum foil can be divided into electrochemical aluminum stamping foil and electrochemical aluminum composite foil. The electrochemical aluminum stamping foil usually includes a base film layer, a release layer, a color layer, an aluminum plating layer and a glue layer, and the preparation process is usually to coat the release layer coating, the color layer coating on the base film layer, vacuum plating aluminum, and then coat glue, and finally roll the finished product. The electrochemical aluminum composite foil does not contain a release layer. The base film layer, as the carrier of the electrochemical aluminum foil structure, is usually made of PET, BOPP and other films. After the stamping process, the base film layer will be torn off, and the base film will remain in the composite process. The release layer can make the color layer and the aluminum plating layer separate smoothly from the base film during stamping. The color layer and the aluminum plating layer are used to provide the color and pattern effect required by the electrochemical aluminum foil. The aluminum plating layer is used to provide the main metal luster effect. The glue layer mainly plays a transfer or composite function.

[0003] However, the color layer and the aluminum plating layer of the electrochemical aluminum plating foil are easily scratched, worn or oxidized during production and subsequent processing, affecting its use effect, and a protective coating is often needed to improve its durability. However, the existing protective coating often cannot balance the wear resistance, scratch resistance, temperature resistance and weather resistance, affecting the service life of the product. Therefore, it is of great significance to provide a light-cured protective coating for the preparation of electrochemical aluminum stamping foil. After coating the release layer, the UV protective coating can be coated first, and then the color layer coating can be coated, which can effectively protect the color layer and the aluminum plating layer after transfer, improve the durability and use effect of the product. In addition, the UV protective coating can also be applied to electrochemical aluminum composite foil and IMD decorative film. SUMMARY

[0004] The present application relates to the field of coating technology, in particular to a wear-resistant UV bright protective coating for electrochemical aluminum foil and a preparation method thereof. The coating has good wear resistance, scratch resistance, gloss and weather resistance when used, and can be used as an electrochemical aluminum protective layer to improve the durability and use effect of the electrochemical aluminum foil. The preparation method of the film coating is stable, easy to operate, and has high production efficiency, which can meet the needs of industrial production.

[0005] The object of the present application is achieved by the following technical solution: a wear-resistant UV bright protective coating for electrochemical aluminum foil, comprising the following raw materials by weight: polyurethane acrylate resin 40-50 parts, fluorine-modified acrylic resin 15-25 parts, active diluent 20-30 parts, inorganic filler 5-15 parts, photoinitiator 2-7 parts, silane coupling agent 2-5 parts, antioxidant 1-3 parts, leveling agent 1-3 parts.

[0006] Further, the preparation method of the polyurethane acrylate resin comprises the following steps: A1, under nitrogen protection, polyol is added to the reaction container and heated, and polyisocyanate is added dropwise, so that the molar ratio of -OH of polyol to -NCO of polyisocyanate is 1:1.7-2.1, after dropwise addition, catalyst is added, and the reaction is stopped when the measured -NCO reaches 1.1-1.2 times of the initial theoretical residual value, to obtain mixture A; A2, mixture A is cooled, a polymerization inhibitor and a solvent are added, and a hydroxyl-containing acrylate monomer is added dropwise, so that the molar ratio of -OH to the remaining -NCO groups in mixture A is 1:1-1.15, after dropwise addition, heating is carried out, and the reaction is carried out until the residual amount of -NCO is ≤0.1%; A3, the reaction system is cooled to room temperature to obtain a polyurethane acrylate resin.

[0007] Further, in step A1, the polyisocyanate is isophorone diisocyanate and hexamethylene diisocyanate.

[0008] Further, in step A1, the polyol is at least one of polycarbonate diol and polyhexanedioic acid-1,4-butanediol diol.

[0009] Further, in step A1, the catalyst is at least one of an organic tin catalyst and an organic bismuth catalyst.

[0010] Further, in step A2, the polymerization inhibitor is at least one of hydroquinone, p-hydroxyanisole, and 2,6-di-tert-butyl-p-cresol.

[0011] Further, in step A2, the solvent is at least one of acetone, butanone, ethyl acetate, and butyl acetate.

[0012] Further, 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.

[0013] The polyurethane acrylate resin prepared by the application is well matched with fluorine modified acrylic resin, active diluent and other raw materials, which guarantees the uniformity and film-forming property of the coating, and cooperates with inorganic fillers, fluorine modified acrylic resin and other raw materials to improve the scratch resistance and wear resistance of the coating, and has good flexibility, improves the use performance and prolongs the service life of the product.

[0014] Further, the preparation method of the fluorine modified acrylic resin comprises the following steps: B1, under the protection of nitrogen, methyl methacrylate, isooctyl acrylate, hydroxyethyl methacrylate, hexafluorobutyl methacrylate, gamma-methacryloyloxypropyl trimethoxysilane, methacrylic acid and polyhexanedioic acid-1, 4-butanediol glycol are added into a solvent; then an initiator and dodecanethiol are added and uniformly mixed to obtain a premix solution; the initiator and solvent are added into a reaction kettle, and the temperature is raised to 80-90 DEG C, and the premix solution is added dropwise; B2, after the premix solution is added dropwise, the temperature is raised to 95-105 DEG C, and the temperature is lowered to below 40 DEG C after the reaction is completed, and the fluorine modified acrylic resin is obtained.

[0015] The fluorine modified acrylic resin prepared by the above method can be well matched with polyurethane acrylate resin, silane coupling agent and other raw materials, and the comprehensive performance of the protective coating is improved.

[0016] Further, the active diluent is at least one of isobornyl acrylate, caprolactone acrylate, 1, 6-hexanediol diacrylate, trimethylolpropane triacrylate and pentaerythritol triacrylate.

[0017] Further, the inorganic filler is at least one of nano silicon dioxide, nano aluminum oxide and nano titanium dioxide.

[0018] Further, the photoinitiator is at least one of 2, 4, 6-trimethylbenzoyl diphenyl phosphine oxide, phenyl bis (2, 4, 6-trimethylbenzoyl) phosphine oxide and 1-hydroxycyclohexyl phenyl ketone.

[0019] Further, the silane coupling agent is at least one of gamma-methacryloyloxypropyl trimethoxysilane, gamma-glycidyl ether propyl trimethoxysilane and gamma-aminopropyl triethoxysilane.

[0020] Further, the antioxidant is at least one of hindered phenolic antioxidant, phosphite antioxidant and sulfur ester antioxidant.

[0021] Further, the leveling agent is at least one leveling agent selected from the group consisting of silicone polyether, acrylate, and fluorocarbon compound.

[0022] The application also provides a preparation method of the wear-resistant UV bright protective coating for electrochemical aluminum foil, comprising the following steps: (1) mixing polyurethane acrylate resin and fluorine-modified acrylic resin, heating and stirring uniformly; then adding inorganic fillers, silane coupling agent, antioxidant and leveling agent to mix uniformly to obtain material one; (2) adding active diluent and photoinitiator into the material one to mix uniformly to obtain the wear-resistant UV bright protective coating for electrochemical aluminum foil.

[0023] The wear-resistant UV bright protective coating for electrochemical aluminum foil can be used in various ways: (1) when preparing electrochemical aluminum stamping foil, the UV protective coating is coated between the release layer and the color layer, and after the electrochemical aluminum foil stamping process is completed and the base film is removed, the protective layer is located at the outermost layer; (2) after the electrochemical aluminum stamping foil normally completes the stamping process on the printing material, the UV protective coating is coated on the surface of the printing material, and the protective layer is also located at the outermost layer; (3) when preparing electrochemical aluminum composite foil, the UV protective coating is coated between the base film and the color layer, and after the compounding, it becomes the middle interlayer. In the above three use modes, the wear-resistant UV bright protective coating can effectively protect the color layer, the aluminum plating layer and the printing material or the substrate, improve the product durability, and has strong practicability.

[0024] The wear-resistant UV bright protective coating for electrochemical aluminum foil has the advantages that: the raw materials such as polyurethane acrylate resin, fluorine-modified acrylic resin, active diluent and inorganic fillers are compounded, the raw materials can be well matched, and the prepared coating has good wear resistance, scratch resistance, temperature resistance, gloss and weather resistance when used. The coating can be used as a protective layer for electrochemical aluminum foil to improve the product durability, 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 wear-resistant UV bright protective coating for electrochemical aluminum foil has stable process, is easy to control, has high production efficiency, and is beneficial to industrialized production. DETAILED DESCRIPTION

[0025] In order to facilitate the understanding of those skilled in the art, the application will be further described below in combination with examples, and the content mentioned in the embodiments is not a limitation of the application.

[0026] In some embodiments of the present application, a wear-resistant UV bright protective coating for electrochemical 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 active 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.

[0027] In some embodiments of the present application, the preparation method of the polyurethane acrylate resin comprises the following steps: A1, under nitrogen protection, 40-50 parts of polyol is added to a reaction container, and the temperature is raised to 50-60℃, then polyisocyanate is added dropwise, the amount of polyisocyanate added is such that the molar ratio of -OH of polyol to -NCO of polyisocyanate is 1:1.8-2.1, the dropwise adding time is 30-90min, after the dropwise adding is completed, 0.01-0.1 parts of catalyst is added, the temperature is raised to 70-75℃, and the reaction is kept for 2-3h, then the -NCO content is determined by di-n-butylamine method, and the reaction is stopped when the -NCO content reaches 1.1-1.2 times of the initial theoretical residual value, to obtain mixture A; A2, mixture A is cooled to 40-50℃, 0.05-0.2 parts of polymerization inhibitor and 30-60 parts of solvent are added, stirring for 10-30min, then hydroxyl-containing acrylate monomer is slowly added dropwise, the amount of hydroxyl-containing acrylate monomer added is such that the molar ratio of -OH to the remaining -NCO groups in mixture A is 1.0-1.15:1, the dropwise adding time is 30-90min, after the dropwise adding is completed, the temperature is raised to 60-70℃, and the reaction is carried out until the residual amount of -NCO is ≤0.1%; A3, the reaction system is cooled to room temperature to obtain polyurethane acrylate resin.

[0028] In some embodiments of the present application, in step A1, the polyisocyanate is at least one of isophorone diisocyanate and hexamethylene diisocyanate.

[0029] In some embodiments of the present application, in step A1, the polyol is at least one of polycarbonate diol and poly-1,4-butanediol adipate diol.

[0030] In some embodiments of the present application, in step A2, the polymerization inhibitor is at least one of hydroquinone, p-hydroxyanisole and 2,6-di-tert-butyl-p-cresol.

[0031] In some embodiments of the present application, 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.

[0032] In some embodiments of the present application, the preparation method of the fluorine modified acrylic resin comprises the following steps: B1, under the protection of nitrogen, methyl methacrylate, isooctyl acrylate, hydroxyethyl methacrylate, hexafluorobutyl methacrylate, gamma-methacryloxypropyl trimethoxysilane, methacrylic acid and polyhexanedioic acid-1,4-butanediol glycol are added into a solvent; then an initiator and dodecanethiol are added and uniformly mixed to obtain a premix solution for standby; another initiator and solvent are added into a reaction kettle, and then the premix solution is added dropwise after warming; B2, after the premix solution is added dropwise, the reaction is carried out for preservation; the initiator and solvent are added, and the reaction is continuously carried out for warming, and then the reaction is completed, and the temperature is reduced to below 40℃, and the product is discharged to obtain the fluorine modified acrylic resin.

[0033] In some embodiments of the present application, the preparation method of the fluorine modified acrylic resin comprises the following steps: B1, under the protection of nitrogen, 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 gamma-methacryloxypropyl trimethoxysilane, 1-3 parts of methacrylic acid and 4-8 parts of polyhexanedioic acid-1,4-butanediol glycol are added into 60-80 parts of a solvent; then 0.3-0.6 parts of an initiator and 0.1-0.5 parts of dodecanethiol are added and uniformly mixed to obtain a premix solution for standby; another 0.2-0.5 parts of an initiator and 10-20 parts of a solvent are added into a reaction kettle, and then the premix solution is added dropwise after warming to 80-90℃, and the dropwise adding time is 60-120 min; B2, after the premix solution is added dropwise, the reaction is carried out for 2.5-3.5 h; 0.2-0.5 parts of an initiator and 20-30 parts of a solvent are added, and then the temperature is raised to 95-105℃, and the reaction is carried out for 90-150 min, and then the temperature is reduced to below 40℃, and the product is discharged to obtain the fluorine modified acrylic resin.

[0034] In steps B1 and B2, the initiator is at least one of dibenzoyl peroxide, ammonium persulfate and potassium persulfate; and the solvent is at least one of butyl acetate and propylene glycol methyl ether acetate. In some embodiments of the present application, the solvent is composed of butyl acetate and propylene glycol methyl ether acetate according to a mass ratio of 3-4:1-2.

[0035] In some embodiments of the present application, the active diluent is at least one of isobornyl acrylate, caprolactone acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate and pentaerythritol triacrylate.

[0036] In some embodiments of the present application, the inorganic filler is at least one of nano-silica, nano-alumina and nano-titanium dioxide, and the particle size is 30-80 nm.

[0037] In some embodiments of the present application, the photoinitiator is at least one of 2,4,6-trimethylbenzoyl diphenyl phosphine oxide, phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide and 1-hydroxycyclohexyl phenyl ketone.

[0038] In some embodiments of the present application, the silane coupling agent is at least one of γ-methacryloxypropyl trimethoxysilane, γ-glycidyl ether propyl trimethoxysilane and γ-aminopropyl triethoxysilane.

[0039] In some embodiments of the present application, the antioxidant is at least one of hindered phenolic antioxidant, phosphite antioxidant and sulfur ester antioxidant.

[0040] In some embodiments of the present application, the leveling agent is at least one leveling agent of silicone polyether, acrylate and fluorocarbon compound.

[0041] In some embodiments of the present application, a preparation method of a wear-resistant UV bright protective coating for electrochemical aluminum foil comprises the following steps: (1) mixing polyurethane acrylate resin and fluorine-modified acrylic resin, heating to 60-70℃, stirring at a speed of 300-600 rpm for 10-40 min; then adding inorganic filler, silane coupling agent, antioxidant and leveling agent, stirring at a speed of 600-1200 rpm for 20-60 min, to obtain material one; (2) adding active diluent and photoinitiator into material one and mixing uniformly, stirring at a speed of 300-600 rpm for 20-60 min, then vacuum degassing under the condition of -0.06 ~ -0.095 MPa, to obtain the wear-resistant UV bright protective coating for electrochemical aluminum foil.

[0042] Example 1 In this embodiment, a wear-resistant UV bright protective coating for electrochemical aluminum foil comprises the following raw materials by weight: polyurethane acrylate resin 45 parts, fluorine-modified acrylic resin 20 parts, active diluent 25 parts, inorganic filler 10 parts, photoinitiator 5 parts, silane coupling agent 3 parts, antioxidant 1.5 parts, leveling agent 2 parts.

[0043] Further, the preparation method of the polyurethane acrylate resin comprises the following steps: A1, under nitrogen protection, polyol 45 parts was added into a reaction vessel, heated to 55°C, and polyisocyanate was added dropwise so that the molar ratio of -OH of polyol to -NCO of polyisocyanate was 1:1.9, the dropwise time was 60 min, after the dropwise addition was completed, dibutyltin dilaurate 0.05 parts was added, and the temperature was raised to 72°C; the -NCO content was determined by di-n-butylamine method, and the reaction was stopped when the -NCO reached 1.1 times the initial theoretical residual value, to obtain mixture A; A2, mixture A was cooled to 45°C, and polymerization inhibitor 0.1 parts and solvent propylene glycol methyl ether acetate 40 parts were added, stirred for 20 min, and then hydroxyethyl acrylate was slowly added dropwise so that the molar ratio of -OH to the remaining -NCO groups in mixture A was 1.05:1, the dropwise time was 60 min, after the dropwise addition was completed, the temperature was raised to 65°C, and the reaction was continued until the -NCO residual amount was ≤0.1%; A3, the reaction system was cooled to room temperature to obtain a polyurethane acrylate resin.

[0044] 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 polyhexanedioic acid-1,4-butanediol diol (molecular weight 1000) in a weight ratio of 3:2. Isophorone diisocyanate is WANNATE® IPDI from Wanhua Chemical. The molecular weight of polyhexanedioic acid-1,4-butanediol diol is 2000, and HY-2022 from Jining Tangyi Chemical is used. The molecular weight of polycarbonate diol is 1000, and HK-B10 from Shandong Moore Chemical is used.

[0045] Further, in step A2, the polymerization inhibitor is p-hydroxyanisole; and the hydroxyl-containing acrylate monomer is hydroxyethyl acrylate.

[0046] Further, the preparation method of the fluorine-modified acrylic resin comprises the following steps: B1, under nitrogen protection, methyl methacrylate 35 parts, isooctyl acrylate 25 parts, hydroxyethyl methacrylate 5 parts, hexafluorobutyl methacrylate 16 parts, γ-methacryloyloxypropyl trimethoxysilane 4 parts, methyl methacrylate 2 parts and polyhexanedioic acid-1,4-butanediol diol 6 parts were added into a solvent 70 parts; then initiator 0.4 parts and dodecanethiol 0.2 parts were added, mixed uniformly to obtain a premix, and reserved for use; another initiator 0.3 parts and solvent 10 parts were added into a reaction kettle, heated to 85°C, and the premix was added dropwise at a constant speed, the dropwise time was 120 min; the initiator was dibenzoyl peroxide, the solvent was composed of butyl acetate and propylene glycol methyl ether acetate in a mass ratio of 7:3; the molecular weight of polyhexanedioic acid-1,4-butanediol diol was 2000; B2, after the premixing liquid is added, the reaction is carried out for 3h; 0.3 parts of initiator and 10 parts of solvent are added, the temperature is raised to 95℃, the reaction is carried out for 120min, the temperature is reduced to below 40℃, the material is discharged, and a fluorine-modified acrylic resin is obtained.

[0047] Further, the active diluent is composed of isobornyl acrylate, 1,6-hexanediol diacrylate and pentaerythritol triacrylate according to a weight ratio of 3:1:1.

[0048] Further, the inorganic filler is composed of nano-silicon dioxide and nano-aluminum oxide according to a mass ratio of 2:1, and the particle size is 30-80nm.

[0049] Further, the photoinitiator is composed of 2,4,6-trimethylbenzoyl diphenyl phosphine oxide and 1-hydroxycyclohexyl phenyl ketone according to a mass ratio of 1:1.

[0050] Further, the silane coupling agent is γ-methacryloyl oxypropyl trimethoxysilane.

[0051] Further, the antioxidant is composed of antioxidant 1010 and antioxidant 168 according to a mass ratio of 2:1; and the leveling agent is BYK-333.

[0052] In the embodiment, a preparation method of a wear-resistant UV bright protective coating for an electrochemical aluminum foil comprises the following steps: (1) polyurethane acrylate resin and fluorine-modified acrylic resin are mixed, the temperature is raised to 65℃, and stirring is carried out at a speed of 500 rpm for 20min; then inorganic filler, silane coupling agent, antioxidant and leveling agent are added, and stirring is carried out at a speed of 1000 rpm for 30min, to obtain material one; (2) active diluent and photoinitiator are added to material one and uniformly mixed, stirring is carried out at a speed of 500 rpm for 30min, and then vacuum degassing is carried out under the condition of-0.09 MPa, to obtain the wear-resistant UV bright protective coating for the electrochemical aluminum foil.

[0053] Example 2 In the embodiment, a wear-resistant UV bright protective coating for an electrochemical aluminum foil comprises the following raw materials by weight: 40 parts of polyurethane acrylate resin, 25 parts of fluorine-modified acrylic resin, 25 parts of active 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.

[0054] Further, the preparation method of the polyurethane acrylate resin comprises the following steps: A1, under nitrogen protection, polyol 45 parts was added into a reaction vessel, heated to 55℃, dropwise added polyisocyanate, so that the molar ratio of -OH of polyol and -NCO of polyisocyanate was 1:1.9, the dropwise adding time was 60 min, after the dropwise adding was completed, dibutyltin dilaurate 0.05 parts was added, heated to 70℃; -NCO content was determined by di-n-butylamine method, when the measured -NCO reached 1.1 times of the initial theoretical residual value, the reaction was stopped, mixture A was obtained; A2, mixture A was cooled to 40℃, added polymerization inhibitor 0.1 parts and solvent propylene glycol methyl ether acetate 40 parts, stirred for 20 min, slowly dropwise added hydroxyethyl acrylate, so that the molar ratio of -OH and the remaining -NCO groups in mixture A was 1.05:1, the dropwise adding time was 60 min, after the dropwise adding was completed, heated to 60℃, reacted until the residual amount of -NCO was ≤0.1%; A3, the reaction system was cooled to room temperature, polyurethane acrylate resin was obtained.

[0055] Further, in step A1, the polyisocyanate was composed of isophorone diisocyanate and hexamethylene diisocyanate according to a weight ratio of 4:1; the polyol was composed of polycarbonate diol (molecular weight 2000) and polyhexanedioic acid-1,4-butanediol diol (molecular weight 1000) according to a weight ratio of 3:2.

[0056] Further, in step A2, the polymerization inhibitor was p-hydroxyanisole; the hydroxyl-containing acrylate monomer was hydroxyethyl acrylate.

[0057] Further, the preparation method of the fluorine-modified acrylic resin included the following steps: B1, under nitrogen protection, methyl methacrylate 35 parts, isooctyl acrylate 25 parts, hydroxyethyl methacrylate 5 parts, hexafluorobutyl methacrylate 16 parts, γ-methacryloyloxypropyl trimethoxysilane 4 parts, methyl methacrylate 2 parts and polyhexanedioic acid-1,4-butanediol diol 6 parts were added into solvent 70 parts; then initiator 0.4 parts and dodecanethiol 0.2 parts were added, mixed uniformly, a premix was obtained, and was ready for use; another initiator 0.3 parts and solvent 10 parts were added into a reaction kettle, heated to 85℃, the premix was added at a constant speed, the dropwise adding time was 120 min; the initiator was dibenzoyl peroxide, the solvent was composed of butyl acetate and propylene glycol methyl ether acetate according to a mass ratio of 7:3; B2, after the dropwise adding of the premix was completed, the reaction was carried out for 3 h; initiator 0.3 parts and solvent 10 parts were added, heated to 95℃, reacted for 120 min, cooled to below 40℃, discharged, and the fluorine-modified acrylic resin was obtained.

[0058] Further, the inorganic filler is nano-silica with a particle size of 30-80 nm. The silane coupling agent is γ-methacryloxypropyltrimethoxysilane.

[0059] In the embodiment, a preparation method of the wear-resistant UV bright protective coating for electrochemical aluminum foil includes the following steps: (1) Mix the polyurethane acrylate resin and the fluorine-modified acrylic resin, and heat to 60°C. Stir at a speed of 400 rpm for 30 min. Then add the inorganic filler, the silane coupling agent, the antioxidant, and the leveling agent. Stir at a speed of 1200 rpm for 20 min to obtain material one; (2) Mix the active diluent and the photoinitiator uniformly in the material one. Stir at a speed of 400 rpm for 30 min. Then perform vacuum degassing under the condition of -0.085 MPa to obtain the wear-resistant UV bright protective coating for electrochemical aluminum foil.

[0060] The remaining contents of the embodiment are the same as those of Example 1, which will not be described here.

[0061] Example 3 In the embodiment, a wear-resistant UV bright protective coating for electrochemical aluminum foil includes the following raw materials by weight: 50 parts of polyurethane acrylate resin, 15 parts of fluorine-modified acrylic resin, 25 parts of active diluent, 8 parts of inorganic filler, 5 parts of photoinitiator, 3 parts of silane coupling agent, 1.5 parts of antioxidant, and 2 parts of leveling agent.

[0062] Further, the preparation method of the polyurethane acrylate resin includes the following steps: A1. Under nitrogen protection, add 45 parts of polyol to a reaction container, heat to 55°C, and drop 45 parts of polyol. The molar ratio of -OH of the polyol to -NCO of the polyisocyanate is 1:1.9, the drop time is 60 min, and after the drop is completed, add 0.05 parts of dibutyl tin dilaurate, and heat to 72°C. Determine the -NCO content by the di-n-butylamine method, and stop the reaction when the measured -NCO reaches 1.1 times the initial theoretical residual value. A mixture A is obtained; A2. Cool the 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 drop hydroxyethyl acrylate, so that the molar ratio of -OH to the remaining -NCO groups in the mixture A is 1.05:1, the drop time is 60 min, and after the drop is completed, heat to 65°C, and react until the residual amount of -NCO is ≤0.1%. A3. Cool the reaction system to room temperature to obtain a polyurethane acrylate resin.

[0063] Further, the preparation method of the fluorine-modified acrylic resin includes the following steps: B1, under the protection of nitrogen, methyl methacrylate 35 parts, isooctyl acrylate 25 parts, hydroxyethyl methacrylate 5 parts, hexafluorobutyl methacrylate 16 parts, gamma-methacryloyloxypropyl trimethoxysilane 4 parts, 2 parts of methacrylic acid and polyhexanedioic acid-1, 4-butanediol glycol 6 parts are added into solvent 70 parts; then add initiator 0.4 parts and dodecanethiol 0.2 parts, mix uniformly, get premix, ready for use; take another initiator 0.3 parts and solvent 10 parts into the reaction kettle, heat to 85℃, add the premix at a constant speed, the drop time is 120 min; the initiator is dibenzoyl peroxide, the solvent is composed of butyl acetate and propylene glycol methyl ether acetate according to the mass ratio of 7:3; B2, after the premix is added, react for 3h; add initiator 0.3 parts and solvent 10 parts, heat to 95℃, react for 120 min, cool down to below 40℃, discharge, get fluorine modified acrylic resin.

[0064] Further, the active diluent is composed of isobornyl acrylate, 1, 6-hexanediol diacrylate and pentaerythritol triacrylate according to the weight ratio of 3:1:1.

[0065] Further, the inorganic filler is composed of nano-silicon dioxide and nano-aluminum oxide according to the mass ratio of 2:1, the particle size is 30-80 nm.

[0066] Further, the silane coupling agent is composed of gamma-methacryloyloxypropyl trimethoxysilane and gamma-glycidyl ether propyl trimethoxysilane according to the weight ratio of 2:1.

[0067] In this embodiment, a preparation method of wear-resistant UV bright protective coating for electrochemical aluminum foil, comprising the following steps: (1) mix polyurethane acrylate resin and fluorine modified acrylic resin, heat to 65℃, stir at the speed of 500 rpm for 20 min; then add inorganic filler, silane coupling agent, antioxidant and leveling agent, stir at the speed of 1000 rpm for 30 min, get material one; (2) add active diluent and photoinitiator into material one, mix uniformly, stir at the speed of 500 rpm for 30 min, then vacuum degassing under the condition of-0.09 MPa, get wear-resistant UV bright protective coating for electrochemical aluminum foil.

[0068] The rest of this embodiment is the same as example 1, which will not be repeated here.

[0069] Comparative example 1 The difference between this comparative example and example 1 is that the wear-resistant UV bright protective coating for electrochemical aluminum foil in this comparative example does not contain fluorine modified acrylic resin, and an equal weight of polyurethane acrylate resin is used instead.

[0070] Comparative Example 2 The difference between this comparative example and Example 1 is that the aluminum foil in this comparative example is coated with a wear-resistant UV bright protective coating including the following raw materials in parts by weight: polyurethane acrylate resin 45 parts, fluorine-modified acrylic resin 20 parts, reactive diluent 25 parts, inorganic filler 10 parts, photoinitiator 5 parts, silane coupling agent 3 parts, leveling agent 1.5 parts, antioxidant 2 parts. The acrylic resin used is Zannan Acrylic Resin EBECRYL 8110.

[0071] The wear-resistant UV bright protective coating prepared for Examples 1-3 and Comparative Examples 1-2 is coated on a 20 μm PET base film, and the dry glue amount of the coating is 2.0 g / m 2 The coated wet film is placed in an oven at 80°C for 2 min for pre-curing, and then irradiated with ultraviolet light with an intensity of 500 mW / cm 2 for 30 s, and then placed at 23°C, 50% RH for 24 h to obtain a sample to be tested. The sample is tested for performance, and the test results are shown in Table 1 below: Among them, the wear resistance is tested in accordance with GB / T 1768-2006, the sample is set as a circular piece with a diameter of 100 mm, a CS-10 grinding wheel is used, a load of 1000 g is applied, and the sample is rotated 500 times. The mass loss (mg) is measured, and the measured results are recorded in Table 1.

[0072] The adhesion test is performed using the following method: the sample is set as a rectangular piece with a size of 150 x 150 mm, the surface coating is pasted with 3M600 tape, and the tape is quickly peeled off vertically at 90°. If the detached area is not greater than 5%, it is qualified, and if the detached area is greater than 5%, it is unqualified. For each example and comparative example, 100 samples are tested. If no more than 5 samples are unqualified, it is A; if no more than 15 samples are unqualified, it is B; and if more than 15 samples are unqualified, it is C. The measured results are recorded in Table 1.

[0073] The water resistance test is performed using the following method: after the sample is soaked in deionized water at 23°C for 24 h, the adhesion is tested, and the measured results are recorded in Table 1.

[0074] The gloss is tested in accordance with GB / T 9754-2007 (60°).

[0075] The weather resistance test is performed using the following method: the sample is treated under the following conditions: ultraviolet light with a wavelength of 340 nm, irradiance of 0.76 W / m 2 for 200 h. The gloss retention rate of the coating after irradiation is tested, and the test results are recorded in Table 1.

[0076] The ethanol resistance wiping performance test was performed as follows: a cotton ball soaked in 95% ethanol was used to wipe the coating back and forth 100 times under a pressure of 500 g, and the test results were observed and recorded in Table 1. "No change" means that the coating has no scratches, no wrinkles, and no discoloration; "slight wrinkles and peeling" means that the surface has wrinkles and peeling of ≤5% area. The samples of Examples 1-3 and Comparative Examples 1-2 were bent 180° at a 1 mm shaft diameter, and none of them had cracks or peeling.

[0077] According to the test results, the abrasion-resistant UV bright protective coating for the electrochemical aluminum foil of Examples 1-3 has excellent abrasion resistance, scratch resistance, and weather resistance, and also has good gloss, compared with Comparative Examples 1-2. It can be used as an electrochemical aluminum protective layer to improve the durability of the product and has strong practicality.

[0078] The above specific examples are further illustrations of the technical solutions and beneficial effects of the present application, and are not limitations on the embodiments. Any obvious substitutions for those skilled in the art without departing from the concept of the present application are within the protection scope of the present application.

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 fluorine-modified 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.

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 1, 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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