All-solid-content UV-curable coating composition

Abstract

The invention discloses a full-solid-content UV curing coating composition which comprises resin and monomers, the resin comprises phenolic aldehyde modified epoxy acrylic resin and polyurethane acrylic resin, and the monomers comprise two or more diacrylates. The invention also discloses a preparation method of the full-solid-content UV-curable coating composition, which comprises the following steps: (1) mixing the resin, a part of monomers and optional auxiliaries and pigments and fillers to obtain a premix; and (2) adding the other part of monomers and optional auxiliaries into the premix in the step (1). Further disclosed is a substrate coated with the full solid content UV curable coating composition.

Description

Technical Field

[0001] This invention relates to the field of coatings, and more specifically to all-solid UV-curable coatings. Background Technology

[0002] With the rapid global adoption of new energy electric vehicles, automakers are placing increasing emphasis on battery safety, requiring dielectric films to possess characteristics such as high shear strength (LSS), good electrolyte resistance, long-term stability, and high voltage resistance. Currently, blue film coating is a commonly used solution for battery dielectric properties. However, blue films perform poorly in terms of edge coverage, high voltage resistance, long-term stability, LSS, and adhesion, posing risks of leakage and fire. Dielectric coatings are an alternative solution to traditional blue films. However, current commercial dielectric coatings generally contain organic solvents such as benzene and xylene. Powder coatings require curing at temperatures above 130°C, with curing times exceeding 20 minutes, making the application process complex. Therefore, there is a need to develop a low-solvent, easy-to-apply dielectric coating with excellent mechanical properties. Summary of the Invention

[0003] To address the above technical problems, the inventors have conducted extensive research and developed a fully solid-content UV-curable coating composition. This coating composition has low VOC, can be cured at room temperature, and exhibits good edge and corner coverage, high LSS, high voltage resistance, good electrolyte resistance, and environmental aging resistance, thus meeting the application requirements of battery environments.

[0004] The present invention provides an all-solid UV-curable coating composition comprising a resin and a monomer, wherein the resin comprises a phenolic modified epoxy acrylate resin and a polyurethane acrylate resin, and the monomer comprises two or more diacrylates.

[0005] The present invention also provides a method for preparing the aforementioned all-solids UV-curable coating composition, comprising:

[0006] (1) A premix is ​​obtained by mixing a resin, a portion of monomers, and optional additives and pigments / fillers; and

[0007] (2) Add another portion of monomers and optional auxiliaries to the premix of step (1).

[0008] The present invention also provides a coated substrate, comprising a substrate and the said fully solid UV-curable coating composition coated on at least a portion of the substrate.

[0009] The features and advantages of the present invention will be specifically presented in the following detailed description of the embodiments. Detailed Implementation

[0010] As used herein, unless otherwise expressly stated, expressions such as numerical values, ranges, contents, or percentages used in the specification and claims should be considered to vary in all cases according to the term "about," even if the term is not explicitly stated. Therefore, unless stated to the contrary, the numerical parameters listed in the specification and claims herein are approximate values ​​and may vary according to the performance desired by the invention.

[0011] Although the numerical ranges and parameters listed in this invention are approximate, the values ​​listed in the specific embodiments are recorded as accurately as possible. However, any value inherently possesses a certain degree of error. This error is a necessary consequence of the standard deviation derived from the corresponding measurement method.

[0012] Furthermore, it should be understood that any numerical range described herein is intended to include all subranges falling within it. For example, the range “1 to 10” is intended to include all subranges between the minimum value 1 and the maximum value 10, i.e., a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

[0013] In this application, unless otherwise expressly stated, the use of the singular includes the plural and the plural includes the singular. Furthermore, in this application, unless otherwise expressly stated, the word "or" is used to mean "and / or," even if "and / or" may be explicitly used in certain circumstances. Additionally, in this application, unless otherwise expressly stated, the word "a" or "an" is used to mean "at least one." For example, "a" resin, "a" coating, etc., refer to any one or more of these articles. And, as those skilled in the art will recognize, features of one embodiment can be used in conjunction with other embodiments, even if not explicitly stated.

[0014] In this application, the terms "comprising" and similar terms mean including but not limited to, and do not exclude any variations or additions. Furthermore, although the present invention has described coating compositions and / or methods, etc., using terms such as "comprising," the coating compositions, etc., detailed herein may also be described as "consisting substantially of" or "consisting of".

[0015] As described above, the present invention relates to a fully solid UV-curable coating composition comprising a resin and a monomer, wherein the resin comprises a phenolic modified epoxy acrylate resin and a polyurethane acrylate resin, and the monomer comprises two or more diacrylates.

[0016] As used herein, the term “UV curing” refers to the process by which materials in a coating composition are cured into a film by ultraviolet (UV) radiation. In this context, the term “curing” refers to the process by which materials become “fixed” to form an irreversible cross-linked network, no longer flowing, melting, or dissolving.

[0017] As used herein, the term "total solids content" (also referred to as 100 wt% solids content) means that the cured coating composition comprises 100 wt% or nearly 100 wt% of the total mass of the coating composition. The total solids content UV-curable coating compositions according to the present invention have the advantage of low VOC release. As stated herein, "VOC (volatile organic compounds)" refers to any organic compound with a boiling point less than or equal to 250°C (482°F) measured at a standard atmospheric pressure of 101.3 kPa.

[0018] In this document, the term "resin" may be used interchangeably with "polymer." "Phenolic modified epoxy acrylate resin" refers to a polymer obtained by ring-opening esterification of the epoxy groups in a phenolic epoxy resin with (meth)acrylic acid. "Polyurethane acrylate resin" comprises a polyurethane portion and an acrylate portion linked by chemical bonds, wherein the polyurethane portion comprises organic units linked by urethane bonds, and the acrylate portion is derived from (meth)acrylic acid monomers.

[0019] Suitablely, the phenolic modified epoxy acrylate resin may have a functionality of 2-3. As used herein, "functionality" refers to the average number of functional groups per molecule that can participate in the reaction.

[0020] Suitablely, the polyurethane acrylic resin may have a functionality of 1-2. As used herein, "functionality" refers to the average number of functional groups per molecule that can participate in the reaction.

[0021] In the UV-curable coating composition according to the present invention, the weight ratio of the phenolic modified epoxy acrylate resin to the polyurethane acrylate resin can be from 0.15:1 to 17:1. Suitably, the weight ratio of the phenolic modified epoxy acrylate resin to the polyurethane acrylate resin can be 0.15:1 or higher, 0.2:1 or higher, 0.3:1 or higher, 0.4:1 or higher, 0.5:1 or higher, 0.6:1 or higher, 0.7:1 or higher, 0.8:1 or higher, 0.9:1 or higher, 1:1 or higher, 1.1:1 or higher, 1.2:1 or higher, 1.3:1 or higher, 1.4:1 or higher, 1.5:1 or higher, 1.6:1 or higher, 1.7:1 or higher, 1.8:1 or higher. The ratios are 1.9:1 or higher, 2:1 or higher, 2.1:1 or higher, 2.2:1 or higher, 2.3:1 or higher, 2.4:1 or higher, 2.5:1 or higher, 2.6:1 or higher, 2.7:1 or higher, 2.8:1 or higher, 2.9:1 or higher, or 3:1 or higher, and / or 17:1 or lower, 15:1 or lower, 13:1 or lower, 11:1 or lower, 9:1 or lower, 7:1 or lower, 6:1 or lower, 5:1 or lower, 4.5:1 or lower, 4:1 or lower, or 3.5:1 or lower. For example, the weight ratio of the phenolic modified epoxy acrylate resin to the polyurethane acrylate resin can be from 0.3:1 to 9:1, from 0.4:1 to 6:1, or within the range of any of the above ratios.

[0022] Based on the total weight of the UV-curable coating composition, the content of the phenolic modified epoxy acrylate resin may be 5 wt% or higher, 10 wt% or higher, or 15 wt% or higher, and / or 50 wt% or lower, 40 wt% or lower, or 30 wt% or lower. Based on the total weight of the UV-curable coating composition, the content of the phenolic modified epoxy acrylate resin may be 5-50 wt%, 10-40 wt%, 15-30 wt%, or within the range of any of the above values.

[0023] Based on the total weight of the UV-curable coating composition, the content of the polyurethane acrylic resin may be 3 wt% or higher, 8 wt% or higher, or 15 wt% or higher, and / or 40 wt% or lower, 30 wt% or lower, or 20 wt% or lower. Based on the total weight of the UV-curable coating composition, the content of the polyurethane acrylic resin may be 3-40 wt%, 8-30 wt%, 15-20 wt%, or within the range of any of the above values.

[0024] In the monomers of the UV-curable coating composition according to the invention, the diacrylate may comprise tripropylene glycol diacrylate and 1,6-hexanediol diacrylate. Suitably, the weight ratio of the tripropylene glycol diacrylate to the 1,6-hexanediol diacrylate may be from 0.15:1 to 6:1. Suitably, the weight ratio of the tripropylene glycol diacrylate to the 1,6-hexanediol diacrylate may be 0.15:1 or higher, 0.4:1 or higher, 0.8:1 or higher, 1:1 or higher, or 1.2:1 or higher, and / or 6:1 or lower, 5:1 or lower, 4:1 or lower, 3:1 or lower, 2:1 or lower, 1.8 or lower, 1.6 or lower, or 1.4 or lower. For example, the weight ratio of the tripropylene glycol diacrylate to the 1,6-hexanediol diacrylate can be from 0.4:1 to 3:1, from 0.8:1 to 2:1, or within any of the above-mentioned ratios.

[0025] Based on the total weight of the UV-curable coating composition, the content of the tripropylene glycol diacrylate may be 5 wt% or higher, 10 wt% or higher, or 15 wt% or higher, and / or 30 wt% or lower, 25 wt% or lower, or 20 wt% or lower. Based on the total weight of the UV-curable coating composition, the content of the tripropylene glycol diacrylate may be 5-30 wt%, 10-25 wt%, 15-20 wt%, or within the range of any of the above values.

[0026] Based on the total weight of the UV-curable coating composition, the content of the 1,6-hexanediol diacrylate may be 5 wt% or higher, 10 wt% or higher, or 15 wt% or higher, and / or 30 wt% or lower, 25 wt% or lower, or 20 wt% or lower. Based on the total weight of the UV-curable coating composition, the content of the 1,6-hexanediol diacrylate may be 5-30 wt%, 10-25 wt%, 15-20 wt%, or within the range of any of the above values.

[0027] In the UV-curable coating composition according to the present invention, a specific combination of resins and monomers can balance electrolyte resistance and flexibility, while also ensuring good adhesion of the coating film.

[0028] The UV-curable coating composition according to the present invention may further include a photoinitiator. The photoinitiator may include 1-hydroxy-cyclohexylphenyl ketone and / or 2,2-dimethoxy-2-phenylacetophenone. For example, the photoinitiator may include 1-hydroxy-cyclohexylphenyl ketone and 2,2-dimethoxy-2-phenylacetophenone. Suitably, the weight ratio of the 1-hydroxy-cyclohexylphenyl ketone to the 2,2-dimethoxy-2-phenylacetophenone may be from 0.2:1 to 4:1. Suitably, the weight ratio of the 1-hydroxy-cyclohexylphenyl ketone to the 2,2-dimethoxy-2-phenylacetophenone may be 0.2:1 or higher, 0.4:1 or higher, 0.6:1 or higher, 0.8:1 or higher, 1:1 or higher, 1.2:1 or higher, or 1.4:1 or higher, and / or 4:1 or lower, 3.5:1 or lower, 3:1 or lower, 2.5:1 or lower, 2:1 or lower, or 1.5:1 or lower. For example, the weight ratio of the 1-hydroxy-cyclohexylphenyl ketone to the 2,2-dimethoxy-2-phenylacetophenone may be from 0.2:1 to 3:1, from 0.4:1 to 1.5:1, or within the range of any of the above ratios.

[0029] Based on the total weight of the UV-curable coating composition, the photoinitiator content can be 0.4 wt% or higher, 1 wt% or higher, or 2 wt% or higher, and / or 20 wt% or lower, 10 wt% or lower, or 6 wt% or lower. Based on the total weight of the UV-curable coating composition, the photoinitiator content can be 0.4-20 wt%, 1-10 wt%, 2-6 wt%, or within the range of any of the above values.

[0030] The UV-curable coating composition according to the present invention may further include an adhesion promoter / coupling agent. In this document, " / " represents and / or. Suitably, the adhesion promoter / coupling agent may include phosphate ester adhesion promoters, silane coupling agents, titanate coupling agents, and / or zirconate coupling agents.

[0031] Based on the total weight of the UV-curable coating composition, the content of the adhesion promoter / coupling agent may be 0.5 wt% or higher, 1 wt% or higher, or 2 wt% or higher, and / or 10 wt% or lower, 7 wt% or lower, or 5 wt% or lower. Based on the total weight of the UV-curable coating composition, the content of the adhesion promoter / coupling agent may be 0.5-10 wt%, 1-7 wt%, 2-5 wt%, or within the range of any of the above values.

[0032] The UV-curable coating composition according to the present invention may further include pigments and fillers. The pigments and fillers refer to pigments and / or fillers. Suitably, the fillers may include inorganic fillers. Suitably, the inorganic fillers may include silicate powders and / or metal oxides. Suitably, the silicate powders may include talc and / or silica fume. Suitably, the metal oxides may include magnesium oxide and / or zinc oxide.

[0033] Based on the total weight of the UV-curable coating composition, the content of the pigments and fillers may be 2 wt% or higher, 5 wt% or higher, or 10 wt% or higher, and / or 30 wt% or lower, 20 wt% or lower, or 15 wt% or lower. Based on the total weight of the UV-curable coating composition, the content of the pigments and fillers may be 2-30 wt%, 5-20 wt%, 10-15 wt%, or within the range of any of the above values.

[0034] The UV-curable coating composition according to the invention may further include a rheology modifier. Suitably, the rheology modifier may include fumed silica. Based on the total weight of the UV-curable coating composition, the content of the rheology modifier may be from 0.2 to 5 wt%.

[0035] The UV-curable coating composition according to the present invention may further include a leveling agent. The leveling agent content may be from 0.2 to 5 wt% based on the total weight of the UV-curable coating composition.

[0036] The UV-curable coating composition according to the present invention may further include a wetting and dispersing agent. Suitably, the wetting and dispersing agent may include a nonionic wetting and dispersing agent. Based on the total weight of the UV-curable coating composition, the content of the wetting and dispersing agent may be from 0.2 to 5 wt%.

[0037] The UV-curable coating composition according to the present invention may further include a defoamer. The content of the defoamer may be from 0.2 to 5 wt%, based on the total weight of the UV-curable coating composition.

[0038] The UV-curable coating composition according to the invention may further include one or more other auxiliary components (additives), including but not limited to: preservatives that protect the coating from mold; pH adjusters that control and stabilize the coating; waxes that improve scratch resistance and feel; and so on. When these auxiliary components are present, each auxiliary component is present in an amount of up to about 5 wt% based on the total weight of the UV-curable coating composition.

[0039] Suitably, the fully solids-containing UV-curable coating composition according to the present invention may include: based on the total weight of the coating composition,

[0040] 5-50 wt% phenolic modified epoxy acrylic resin;

[0041] 3-40 wt% polyurethane acrylic resin;

[0042] 5-30 wt% tripropylene glycol diacrylate;

[0043] 5-30 wt% 1,6-hexanediol diacrylate; and

[0044] 0.4-20 wt% photoinitiator.

[0045] Suitably, the fully solids-containing UV-curable coating composition according to the present invention may include: based on the total weight of the coating composition,

[0046] 10-30 wt% phenolic modified epoxy acrylic resin;

[0047] 3-20 wt% polyurethane acrylic resin;

[0048] 5-20 wt% tripropylene glycol diacrylate;

[0049] 5-20 wt% of 1,6-hexanediol diacrylate;

[0050] 2-10 wt% photoinitiator; and

[0051] 1-7 wt% adhesion promoter / coupling agent.

[0052] The present invention also relates to a method for preparing the aforementioned all-solids-content UV-curable coating composition, comprising:

[0053] (1) A premix is ​​obtained by mixing a resin, a portion of monomers, and optional additives and pigments / fillers; and

[0054] (2) Add another portion of monomers and optional auxiliaries to the premix of step (1).

[0055] Suitablely, step (1) further includes grinding the premix to a fineness ≤35 μm. Hereinafter, “fineness” refers to the maximum particle size in the material. Suitablely, step (1) further includes grinding the premix to a fineness ≤25 μm.

[0056] Suitablely, step (1) includes mixing the resin, a portion of the monomer and optional additives, and then adding pigments and fillers while stirring.

[0057] The method for preparing a fully solid-content UV-curable coating composition according to the present invention comprises:

[0058] (1) Mix the resin, a portion of the monomer, and optional additives, begin stirring, add pigments and fillers at a speed of 600-900 r / min, continue stirring until uniformly mixed to obtain a premix, and then refine the premix to a fineness ≤25 μm; and

[0059] (2) Add another portion of monomers and optional additives to the premix obtained in step (1) and stir at a speed of 600-900 r / min until the mixture is homogeneous.

[0060] This invention also relates to a fully solid-containing UV-curable coating composition, comprising a substrate and the fully solid-containing UV-curable coating composition coated on at least a portion of the substrate. Suitably, the substrate may include a metal substrate. Suitably, the substrate may include a portion of a battery. Suitably, the substrate may include a pretreated substrate. For example, the pretreatment may include laser polishing and / or plasma treatment.

[0061] The UV-curable coating composition of the present invention can be applied by any standard method known in the art, such as spraying, dipping, rolling, brushing, etc., and then cured under UV irradiation to form a coating. For example, this can be achieved by using an LED lamp or a Ga lamp at 800-1500 mJ / cm². 2 Perform the first curing, then use an Fe lamp at 5500-12000 mJ / cm². 2 A second curing is performed under energy. Suitably, the UV-curable coating composition according to the invention can have a dry film thickness of 70 to 150 μm. As used herein, "dry film thickness" refers to the thickness of the coating after it has been fully cured.

[0062] Example

[0063] The following embodiments further illustrate the invention, but should not be construed as limiting the invention to the details described in the embodiments. Unless otherwise stated, all parts and percentages in the following embodiments are by weight.

[0064] Examples 1-5: Fully Solid UV-Curing Coating Compositions According to the Invention

[0065] According to the components and dosages listed in Table 1 below, the UV-curable coating compositions containing all solids according to the present invention were prepared: Examples 1-5. The specific preparation method includes: sequentially adding resin, a portion of monomer, dispersant, and defoamer to a mixing tank; starting stirring; adding pigments and fillers at a speed of 600-900 r / min; continuing stirring for 30 min to ensure uniform mixing, thus obtaining a premix; transferring the premix to a grinding cylinder; grinding to a fineness ≤25 μm; and filtering the material into a mixing tank; and adding another portion of monomer, photoinitiator, adhesion promoter, leveling agent, and rheology modifier to the material in the mixing tank; uniformly dispersing at a speed of 600-900 r / min for 30 min to obtain the coating composition.

[0066] Table 1. Fully Solid UV-Curing Coating Compositions According to the Present Invention

[0067]

[0068] 1 SICO-O174 from Shandong Silicon Science & Technology New Materials;

[0069] 2 The H2000 is from Wacker, Germany;

[0070] 3 BYK171 from BYK;

[0071] 4 BYK2145 from BYK;

[0072] 5 POLYFLOW KL-406 from Kyoeeisha; and

[0073] 6 WA#1000 from Zibo Jinjiyuan.

[0074] Comparative Examples 1-6: Comparative examples of UV-curable coating compositions with full solids content

[0075] According to the components and dosages listed in Table 2 below, comparative examples of all-solids UV-curable coating compositions were prepared: Comparative Examples 1-6. The specific preparation methods included: sequentially adding resin, a portion of monomer, dispersant, and defoamer to a mixing tank; starting stirring; adding pigments and fillers at a speed of 600-900 r / min; continuing stirring for 30 min to ensure uniform mixing, thus obtaining a premix; transferring the premix to a grinding cylinder; grinding to a fineness ≤25 μm; and filtering the material back into the mixing tank; and adding another portion of monomer, photoinitiator, adhesion promoter, and leveling agent to the material in the mixing tank; uniformly dispersing at a speed of 600-900 r / min for 30 min to obtain the coating composition.

[0076] Table 2. Comparative examples of all-solids UV-curable coating compositions

[0077]

[0078] 1 SICO-O174 from Shandong Silicon Science & Technology New Materials;

[0079] 2 The H2000 is from Wacker, Germany;

[0080] 3 BYK171 from BYK;

[0081] 4 BYK2145 from BYK;

[0082] 5 POLYFLOW KL-406 from Kyoeeisha; and

[0083] 6 WA#1000 from Zibo Jinjiyuan.

[0084] Performance testing:

[0085] The coating compositions of Examples 1-5 and Comparative Examples 1-6 were coated onto a 1 mm thick 3003 aluminum alloy substrate and then cured under the following conditions: using an LED lamp or a Ga lamp at 800-1500 mJ / cm². 2 Perform the first curing, then use an Fe lamp at 5500-12000 mJ / cm². 2 A second curing process is then performed. The cured coating thickness is 110 ± 10 μm.

[0086] The following performance tests were performed on the coated substrates described above:

[0087] 1-Resistant to electrolyte

[0088] The coated substrate was immersed in an electrolyte (including dimethyl carbonate, diethyl carbonate, and ethylene carbonate) at room temperature (20-25°C) for 30 days, and then the leakage current, adhesion, and shear strength of the coating were tested.

[0089] Requirements: Use a 25mm diameter circular electrode; under AC 4kV, the leakage current should be less than 0.5 mA within 60s; under DC 5kV, it should not break down within 60s; the adhesion should be grade 0-1; and the shear strength should be greater than 9 MPa.

[0090] 2- Impact resistance

[0091] The impact resistance of the coating was determined according to the GB / T 1732-2020 standard. Specifically, a 1 kg hammer was used to perform a normal impact, ensuring that the impacted part of the coating was at least 15 mm from the edge and that the edges of each impact point were at least 15 mm apart. The coating surface was then observed and the leakage current of the coating was tested.

[0092] Requirements: Impact height of at least 10 cm, no cracks on the paint film surface; use a 25mm diameter circular electrode, leakage current less than 0.5 mA within 60s under AC 4kV; and no breakdown within 60s under DC 5kV.

[0093] 3-Adhesion

[0094] The adhesion of the coating is determined according to the GB / T 9286-2021 standard.

[0095] 4-Abrasion resistant

[0096] The abrasion resistance of the coating was determined according to GB / T 1768-2006. Specifically, the test load was 1 kg, a CS17 grinding wheel was used, and the rotation speed was 50 r / min. The leakage current of the coating after 3000 revolutions was tested.

[0097] Requirements: Using a 25mm diameter circular electrode, the leakage current should be less than 0.5 mA within 60 seconds under AC 4kV; and the electrode should not break down within 60 seconds under DC 5kV.

[0098] The results of the above tests are summarized in Table 3 below.

[0099] Table 3. Performance test results of Examples 1-5 and Comparative Examples 1-6

[0100]

[0101] *The impact resistance test results indicate that after impact from the listed height, the paint film can meet the requirements of no surface cracks and leakage current.

[0102] The performance test results above show that the all-solid UV-curable coating composition provided by this invention achieves excellent electrolyte resistance, impact resistance, abrasion resistance, and high adhesion through formulation design. Comparative Example 1, which uses only polyurethane acrylate resin without the combination of phenolic modified epoxy acrylate resin and polyurethane acrylate resin, fails to meet application requirements for electrolyte resistance and abrasion resistance. Comparative Example 2, which uses polyurethane acrylate resin combined with difunctional epoxy acrylate, fails to meet the requirements for electrolyte resistance and abrasion resistance, and its impact resistance is reduced. Comparative Example 3, which uses a monomer mixture of tripropylene glycol diacrylate and hydroxyethyl acrylate, results in a coating with unsatisfactory electrolyte resistance and abrasion resistance. Comparative Example 4, which uses only tripropylene glycol diacrylate, also results in a coating with unsatisfactory electrolyte resistance and abrasion resistance. Comparative Example 5, which uses a photoinitiator, results in a coating with unsatisfactory electrolyte resistance, abrasion resistance, and adhesion. Comparative Example 6, which does not use an adhesion promoter / coupling agent, results in poor adhesion of the coating.

[0103] Although specific aspects of the invention have been explained and described, it will be apparent to those skilled in the art that many other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the appended claims are intended to cover all such changes and modifications that fall within the scope of the invention.

Claims

1. A fully solid UV-curable coating composition comprising a resin and a monomer, wherein the resin comprises a phenolic modified epoxy acrylate resin and a polyurethane acrylate resin, and the monomer comprises two or more diacrylates.

2. The UV-curable coating composition of claim 1, wherein the weight ratio of the phenolic modified epoxy acrylate resin to the polyurethane acrylate resin is from 0.15:1 to 17:

1.

3. The UV-curable coating composition of claim 1 or 2, wherein the weight ratio of the phenolic modified epoxy acrylate resin to the polyurethane acrylate resin is 0.4:1 to 6:

1.

4. The UV-curable coating composition according to any one of claims 1-3, wherein the phenolic modified epoxy acrylate resin has a functionality of 2-3.

5. The UV-curable coating composition according to any one of claims 1-4, wherein the polyurethane acrylic resin has a functionality of 1-2.

6. The UV-curable coating composition according to any one of claims 1-5, wherein the monomer comprises tripropylene glycol diacrylate and 1,6-hexanediol diacrylate.

7. The UV-curable coating composition of claim 6, wherein the weight ratio of the tripropylene glycol diacrylate to the 1,6-hexanediol diacrylate is from 0.15:1 to 6:

1.

8. The UV-curable coating composition of claim 6 or 7, wherein the weight ratio of the tripropylene glycol diacrylate to the 1,6-hexanediol diacrylate is 0.8:1 to 2:

1.

9. The UV-curable coating composition according to any one of claims 1-8, further comprising an initiator-based component.

10. The UV-curable coating composition of claim 8, wherein the initiator comprises 1-hydroxy-cyclohexylphenyl ketone and / or 2,2-dimethoxy-2-phenylacetophenone.

11. The UV-curable coating composition according to any one of claims 1-10, further comprising 0.5-10 wt% of an adhesion promoter and / or coupling agent based on the total weight of the coating composition.

12. The UV-curable coating composition of claim 11, wherein the adhesion promoter and / or coupling agent comprises phosphate ester adhesion promoters, silane coupling agents, titanate coupling agents, and / or zirconate coupling agents.

13. The UV-curable coating composition according to any one of claims 1-12, further comprising 2-30 wt% pigments and fillers based on the total weight of the coating composition.

14. The UV-curable coating composition of claim 13, wherein the pigments and fillers comprise silicate inorganic fillers and / or metal oxide inorganic fillers.

15. A method for preparing a UV-curable coating composition containing all solids as described in any one of claims 1-14, comprising: (1) Mix the resin, a portion of the monomer and optional additives and pigments to obtain a premix; and (2) Add another portion of monomers and optional auxiliaries to the premix of step (1).

16. The preparation method of claim 15, wherein step (1) further comprises grinding the premix to a fineness ≤35 μm.

17. A coated substrate comprising a substrate and a fully solid UV-curable coating composition as described in any one of claims 1-14 coated on at least a portion of the substrate.

18. The coated substrate of claim 17, wherein the substrate comprises a metal substrate.

19. The coated substrate as claimed in claim 17 or 18, wherein the substrate comprises a portion of the battery.

20. The coated substrate as claimed in any one of claims 17-19, wherein the substrate comprises a pretreated substrate, the pretreatment comprising laser polishing and / or plasma treatment.

21. The coated substrate according to any one of claims 17-20, wherein the coating formed by the UV-curable coating composition has a thickness of 70 to 150 μm.

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