Aqueous Visible Light Curing Compositions Containing Sodium Anthracene Methyl Sulfate Photoinitiator and Their Applications

Abstract

This invention provides an aqueous visible light curable composition containing anthracene methyl sulfate sodium salt photoinitiator and its application. This photoinitiator, by introducing sulfate-substituted methylene groups at the 9 and 10 positions of the anthracene ring as the main structural component, and using sodium ions as the balancing cation, has the following technical advantages: symmetrical dual ionic groups impart ultra-high water solubility, allowing dispersion without co-solvents; high photoinitiation efficiency, requiring only 0.1%–5% addition for rapid curing; after modification with methyl sulfate, the maximum absorption wavelength of the anthracene ring conjugated system red-shifts to 405±5 nm, perfectly matching industrial LED light sources; good compatibility with water-based resins, resulting in high coating hardness and good adhesion; and it is odorless, meeting environmental protection requirements.

Description

Technical Field

[0001] This invention belongs to the field of photocurable coating technology, specifically relating to an aqueous visible light curable composition using anthracene methyl sulfate sodium salt as a photoinitiator and its application. Background Technology

[0002] With increasingly stringent environmental regulations and the deepening of the concept of sustainable development, waterborne coatings, due to their extremely low emissions of volatile organic compounds (VOCs), have become an important alternative to traditional solvent-based coatings. According to industry statistics, VOC pollution released during coating processing ranks second globally, only after automobile exhaust. Against this backdrop, waterborne UV-curable coatings, combining the dual advantages of "low VOC emissions" and "high-efficiency, energy-saving curing," have become a current research hotspot.

[0003] Photoinitiators are compounds that can absorb light energy and initiate polymerization reactions, and are widely used in fields such as UV-curable coatings, inks, fiber optic coatings, and 3D printing. However, with increasingly stringent environmental and industrial application requirements, traditional photoinitiators still face many challenges in adapting to water-based systems, particularly in terms of water solubility, visible light response, and the long-term stability of the final product, which require further optimization.

[0004] Common photoinitiators are mainly ketone compounds, such as benzoin and its derivatives, benzoin derivatives, and "9H-thioxanthracene-9-one" and its derivatives (such as thioxanthone, thioxanthone, etc.). These compounds exhibit high initiation efficiency in the ultraviolet region and have become widely used photoinitiators on the market. Among them, photoinitiator 2959 (2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone), as an α-hydroxy ketone photoinitiator, has certain hydrophilic properties due to the presence of both hydroxyl and ketone groups in its molecular structure, and has been attempted for application in some aqueous systems. As a widely used aqueous photoinitiator, 2959 has achieved a low odor to some extent, but it has not achieved complete odorlessness; at the same time, although it has good solubility in some organic solvents, its actual water solubility is still insufficient, and it is prone to aggregation in high solid content or complex formulations, affecting curing uniformity; in addition, its light absorption efficiency in long wavelength regions such as 405 nm is limited, and it still mainly relies on ultraviolet light sources, which limits its widespread application in visible light curing systems.

[0005] Currently, aqueous systems place higher demands on photoinitiators: they not only need to possess good water solubility, but also need to be compatible with light sources in the visible light region (such as 405 nm) to achieve efficient initiation, while also considering low migration and environmental friendliness. Existing photoinitiators still have room for improvement in the following aspects:

[0006] (1) Water compatibility needs to be improved: Traditional photoinitiators (such as benzophenones and thioxanthones) are mostly oil-soluble, and phase separation is likely to occur when they are used directly in aqueous systems, affecting the uniformity of curing. Although they can be modified by introducing hydrophilic groups (such as polyether chains, sulfonates, etc.), such structural modifications are often accompanied by a decrease in initiation efficiency or an increase in synthesis complexity.

[0007] (2) Insufficient visible light response: Current industrial photocuring technology is gradually transitioning to long-wavelength LED light sources (such as 405 nm) to improve energy efficiency. However, the maximum absorption of most water-soluble photoinitiators is still concentrated in the short-wave ultraviolet region (<380 nm), and the molar extinction coefficient at 405 nm is low, which limits its application effect.

[0008] (3) Migration and safety need further improvement: Some small molecule photoinitiators (such as Irgacure 907) tend to migrate from the cured film, which may affect the safety of the contact material; in addition, there is room for improvement in the toxicological performance of some initiators. Although migration can be inhibited to some extent by polymerization, it often leads to a decrease in photoreactivity.

[0009] To address these challenges, many studies have attempted to propose improvement measures, such as:

[0010] Self-assembled micelle methods (such as the method reported by Tian et al., which uses PMAA-b-PS to coat oil-soluble photoinitiators) can improve apparent water dispersibility to some extent, but the structure is sensitive to factors such as pH and ionic strength in complex aqueous environments, and its long-term stability still faces challenges.

[0011] While ionic modified benzophenone compounds can improve water solubility, their light response capability near 405 nm is limited, and the residual amine co-initiators in the system may pose a risk of side reactions.

[0012] Polymer photoinitiators perform well in reducing migration, but their synthesis is usually quite complex, and the steric hindrance of the molecular chain may affect photoactivity and reaction rate.

[0013] Anthracene and its derivatives, as a class of classic photosensitizers, possess excellent light absorption properties. However, their traditional structures exhibit poor water solubility, limiting their application in water-based photocuring systems. Therefore, the industry urgently needs to develop a novel photoinitiator that can balance high water solubility, efficient initiation in the visible light region, and low migration, while also matching the operating time window required in actual construction, in order to promote the further development and application of water-based photocuring technology. Summary of the Invention

[0014] Therefore, the purpose of this invention is to overcome the above-mentioned defects of the prior art and provide an environmentally friendly and efficient waterborne photocurable composition, which contains modified anthracene as a water-soluble photoinitiator, so as to solve the problems of poor water solubility, low initiation efficiency and high migration of existing waterborne photoinitiators.

[0015] This invention, based on extensive literature review and experimental research, identifies the following problems and proposes an innovative improvement: Anthracene, due to its unique structure, can undergo rapid cycloaddition dimerization under light irradiation, thus being photobleached. However, this type of compound still has certain limitations in practical applications because its photobleaching process is often too fast to match the operating time window required in actual construction. Traditional solutions (such as increasing the conjugated system or introducing electron-donating groups) can delay bleaching, but at the cost of water solubility or initiation activity.

[0016] This invention innovatively discovers that introducing sterically hindered ionic groups (-CH2SO3) at the 9 and 10 positions of the anthracene ring... - Na + It can simultaneously achieve the following three levels of regulation:

[0017] - Stereoscopic shielding effect: The methylene spatial barrier of the methyl sulfate group effectively inhibits the planar dimerization reaction of anthracene rings, and the photobleaching rate is significantly lower than that of unmodified anthracene, which can meet the time requirements in actual construction.

[0018] - Electronic regulation: The strong electron-withdrawing sulfate group widens the π-π transition band of the conjugated system, causing a red shift in the absorption spectrum and a doubling of the extinction coefficient;

[0019] - Ion anchoring effect: The dual ionic groups bind to the aqueous resin chain through electrostatic interaction, preventing the migration of small molecules.

[0020] Based on the above findings, the present invention provides an aqueous photocurable composition, comprising, based on 100 parts by weight: aqueous photocurable resin A: 30-60 parts; photoinitiator B: 0.1-5 parts; additive C: 0.1-15 parts; water: balance, wherein the photoinitiator B is sodium anthracene-9,10-dimethylene sulfate having the structure of formula (I):

[0021]

[0022] Among them, R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8Each is independently selected from one of hydrogen, C1-C12 alkyl, C3-C12 cycloalkyl, C2-C12 unsaturated hydrocarbon, C1-C12 alkoxy, C6-C12 aryl or aryloxy, C6-C12 aryl or aryloxy substituted with one or more C1-C6 alkyl groups, C6-C12 aryl or aryloxy substituted with one or more C1-C6 alkoxy groups, halogen, cyano, and nitro.

[0023] The aqueous photocurable composition of the present invention can be used for visible light curing that initiates free radical curing. The photoinitiation system of the present invention, when irradiated with a 405 nm light source, can effectively initiate rapid photocuring of free radical monomers / oligomers.

[0024] Waterborne UV-curable resin A

[0025] In this invention, the aqueous photocurable composition comprises an aqueous photocurable resin. The aqueous photocurable resin is conventional, and those skilled in the art can determine which photocurable resins can be used in this invention based on the description herein. In some embodiments of this invention, the aqueous photocurable resin comprises a water-soluble, photocurable unsaturated monomer, such as (meth)acrylamide, methacrylamide, and aqueous polyesters, polyacrylates, and polyurethane resins.

[0026] In some embodiments of the present invention, the waterborne UV-curable resin is selected from at least one of epoxy resin-based polymers and polyurethane-based polymers, used to provide good hardness, adhesion, and solvent resistance of the coating. In some embodiments of the present invention, the waterborne UV-curable resin is selected from one or more of waterborne polyurethane acrylates, waterborne epoxy acrylates, and waterborne polyester acrylates.

[0027] Photoinitiator B

[0028] The photoinitiator B described in this invention is sodium anthracene-9,10-dimethylene sulfate having the structure of formula (I):

[0029]

[0030] Among them, R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8Each is independently selected from one of hydrogen, C1-C12 alkyl, C3-C12 cycloalkyl, C2-C12 unsaturated hydrocarbon, C1-C12 alkoxy, C6-C12 aryl or aryloxy, C6-C12 aryl or aryloxy substituted with one or more C1-C6 alkyl groups, C6-C12 aryl or aryloxy substituted with one or more C1-C6 alkoxy groups, halogen, cyano, and nitro.

[0031] As used herein, the term "alkyl" includes saturated aliphatic hydrocarbons containing both straight and branched chains. For example, the term "C1-C12 alkyl," and the alkyl portion of other groups mentioned herein (e.g., C1-C12 alkoxy), refers to a straight or branched group of 1 to 12 carbon atoms (e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, or n-hexyl).

[0032] As used herein, the term "aryl" can include all carbon monocyclic or fused-ring polycyclic aromatic groups having a conjugated π-electron system. Aryl groups have 6 or 12 carbon atoms in a ring (or multiple rings). Most commonly, aryl groups have 6 carbon atoms in a ring. For example, as used herein, the term "C6-C12 aryl" refers to an aromatic group containing 6 to 12 carbon atoms, such as phenyl or naphthyl.

[0033] As used herein, the term "aryloxy group" refers to all carbon monocyclic or fused-ring polycyclic aromatic groups having a conjugated π-electron system linked by oxygen atoms. The aryl moiety in an aryloxy group has 6 to 12 carbon atoms in the ring (or rings). Most commonly, the aryl moiety in an aryloxy group has 6 carbon atoms in the ring. For example, as used herein, the term "C6-C12 aryloxy group" refers to an aryloxy group with 6 to 12 carbon atoms in the aryl moiety, such as phenoxy (-OC6H5) or naphthoxy (-OC... 10 H7).

[0034] In some preferred embodiments of the present invention, the photoinitiator B is a compound TM1 having the following structure:

[0035] .

[0036] This invention involves specific ionization modification of the anthracene ring, introducing a sodium methyl sulfate group (-CH2SO3) at each of its 9 and 10 positions. - Na + This invention utilizes the compound as a photoinitiator in aqueous photocurable compositions. The present invention reveals that using sodium anthracene methyl sulfate as a photoinitiator in aqueous photocurable compositions offers the following technical advantages:

[0037] 1. Symmetrical dual ionic groups impart ultra-high water solubility, allowing for dispersion without the need for co-solvents;

[0038] 2. It has a wide light absorption range (350-450nm), meeting the needs of most commercially available equipment, and also has high initiation efficiency, requiring only 0.1%-5% to achieve rapid curing;

[0039] 3. After modification with methyl sulfate, the maximum absorption wavelength of the anthracene ring conjugated system is red-shifted to 405±5 nm, which is a perfect match for industrial LED light sources;

[0040] 4. It has good compatibility with water-based resins, resulting in high coating hardness and good adhesion;

[0041] 5. Odorless, meeting environmental protection requirements.

[0042] The anthracene-9,10-dimethylene sodium sulfate salt used in this invention can be prepared using conventional synthetic methods in the art. For example, the corresponding sulfate quaternary ammonium salt can be prepared according to the decarboxylation mechanism described in the literature (e.g., Organic Letters, 2024, 26(27), 5856-5861), and then the sodium sulfate photosensitizer of this invention can be obtained by passing it through a sodium ion exchange column.

[0043] A typical reaction procedure is as follows: Under a nitrogen atmosphere, anthracene acetic acid and ammonium persulfate are added to a round-bottom flask equipped with a magnetic stirrer, along with catalytic amounts of silver nitrate and 4,7-diphenyl-1,10-phenanthroline, as well as KH₂PO₄ and tetraalkylammonium hydrogen sulfate, dissolved in dichloromethane. The reaction is carried out at room temperature. After the reaction is completed by thin-layer chromatography (TLC), the reaction system is washed with saturated brine, the organic phase is collected, dried over anhydrous sodium sulfate, and purified by column chromatography. Then, ion exchange is performed to convert the quaternary ammonium salt to its sodium salt, with a yield typically reaching 80%-90%.

[0044] Additive C

[0045] According to the aqueous visible light curable composition provided by the present invention, the additive C may be selected from one or more of defoamers, thickeners, leveling agents, plasticizers, reactive diluents, dyes, adhesion promoters, polymerization inhibitors, and film-forming agents. In a preferred embodiment of the present invention, the total amount of the additive is 0.5-10 parts by weight.

[0046] The aqueous visible light curable composition provided by the present invention contains an organic reactive diluent, which improves the processability of the coating to facilitate application. In some embodiments of the present invention, the reactive diluent is selected from one or more of polyethylene glycol diacrylate, trimethylolpropane triacrylate, hydroxyethyl acrylate dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol butyl ether, and ethanol.

[0047] A second aspect of the invention also provides the application of the above-described aqueous visible light curing composition, including for preparing light-curing coatings on wood, metal, or plastic surfaces.

[0048] The aqueous visible light curing composition of the present invention uses sodium anthracene methyl sulfate as a photoinitiator, which significantly improves upon existing technologies in terms of spectral absorption, solubility, and migration stability. It achieves high initiation efficiency for visible light, good water solubility, and low migration, and can be widely used in aqueous UV-curing coatings, environmentally friendly inks, and other industrial applications with high requirements for safety and stability. It has significant technical improvement and practical value. Attached Figure Description

[0049] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings, wherein:

[0050] Figure 1 This is the ¹H NMR spectrum of the photoinitiator TM-1 prepared in Example 1 of this invention;

[0051] Figure 2 It is the photoinitiator TM-1 prepared in Example 1 of this invention. 13 C-NMR spectrum;

[0052] Figure 3 This is the UV-Vis absorption spectrum of photoinitiator TM-1 prepared in Example 1 of this invention;

[0053] Figure 4 This is a photobleaching curve of photoinitiator TM-1 prepared in Example 1 of the present invention. Detailed Implementation

[0054] The present invention will be further described in detail below with reference to specific embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0055] Example 1

[0056] Preparation of photoinitiator TM1

[0057] Under a nitrogen atmosphere, 2-(anthracene-9-yl)acetic acid (1.0 mmol), ammonium persulfate (3.0 mmol), AgNO3 (0.05 mmol, 5 mol%), 4,7-diphenyl-1,10-phenanthroline (L: 0.05 mmol, 5 mol%), KH2PO4 (1.2 mmol), and tetrabutylammonium hydrogen sulfate (1.2 mmol) were dissolved in dry dichloromethane (5 mL) in a round-bottom flask equipped with a magnetic stirrer. The mixture was stirred at room temperature for 12 hours until the reaction was complete as monitored by TLC, indicating that the starting material 2-(anthracene-9-yl)acetic acid had been consumed. The reaction system was washed with saturated brine, the organic phase was collected, dried over anhydrous sodium sulfate, purified by column chromatography, and then exchanged using a sodium ion exchange column to obtain anthracene-9,10-dimethylene sulfate sodium salt, denoted as TM1, with a yield of 86%.

[0058]

[0059] Example 2

[0060] The aqueous visible light curable composition of the present invention is prepared according to the following formula by weight:

[0061] Waterborne resin: Waterborne polyurethane acrylate (Zhanxin, UCECOAT® 7156, solid content 50%): 50 parts;

[0062] Sodium anthracene-9,10-dimethylene sulfate prepared in Example 1: 2 parts;

[0063] Reactive diluent: Polyethylene glycol diacrylate (Mn=400): 10 parts;

[0064] BYK-011 defoamer: 0.2 parts;

[0065] Hydroxyethyl cellulose film-forming agent: 1 part;

[0066] Deionized water: 36.8 parts.

[0067] Preparation method: Mix waterborne resin and deionized water and stir until uniform; add anthracene-9,10-dimethylene sulfate sodium salt and reactive diluent in sequence, and stir at 500 r / min for 30 min; add other additives and continue stirring for 15 min to obtain a uniform waterborne visible light curable composition.

[0068] Performance testing

[0069] (a) Solubility test

[0070] At room temperature, the photoinitiator TM1 and photoinitiator 2959 (CAS No.: 106797-53-9, hereinafter referred to as "2959") prepared in Example 1 were dissolved in common organic solvents methanol and acetone, as well as in water, and the solubility was recorded according to the following classification criteria:

[0071] • (Rapid dissolution): Under room temperature and stirring conditions, a clear, transparent, and homogeneous solution can be formed within 1 minute;

[0072] ○ (Slow dissolution): Under room temperature and stirring conditions, a clear, transparent and homogeneous solution can be formed in more than 5 minutes; or it cannot be completely dissolved at room temperature, but a clear, transparent and homogeneous solution can be formed when heated to 50-60℃, and there is no obvious turbidity after returning to room temperature.

[0073] × (Partially dissolved): It cannot be completely dissolved in more than 5 minutes under room temperature and stirring conditions; or it can be completely dissolved when heated to 50-60℃, but becomes obviously cloudy after returning to room temperature.

[0074] The test results are shown in Table 1.

[0075]

[0076] As can be seen from the data in Table 1, the photoinitiator TM1 of the present invention exhibits superior water solubility compared to the conventional water-soluble photoinitiator 2959 in the prior art.

[0077] (II) Measurement of ultraviolet-visible spectroscopy and photobleaching performance

[0078] The ultraviolet-vis absorption spectrum (UV-vis) was measured on a Shimadzu UV-1900 UV-vis spectrophotometer using methanol as the solvent at a concentration of 2 × 10⁻⁶. -5 mol / L.

[0079] According to Beer-Lambert law, the molar extinction coefficient is ε = A. bn / c, where A bn ν is the absorbance of the UV-Vis absorption spectrum, and c is the concentration.

[0080] Photobleaching experiment: Using methanol as solvent, the changes in the UV-Vis absorption spectrum of the sample solution were measured by a Shimadzu UV-1900 UV-Vis spectrophotometer under a 450 nm LED.

[0081] Figure 3 This is the UV-Vis absorption spectrum of TM-1. The UV spectral data are as follows: 353 nm, ε: 5170; 371 nm, ε: 8120; 392 nm, ε: 8080.

[0082] Figure 4The photobleaching curve of TM-1 shows that the photoinitiator TM1 of this invention has very good photobleaching performance in the visible light region. The photobleaching time of TM1 is 60 minutes, that is, it loses its photoinitiating performance in about 60 minutes, which can match the operating time window required in actual construction.

[0083] (iii) Odor test

[0084] Test method: Seven odor judges evaluated the odor of the fully cured samples according to five levels: A - odorless; B - slight odor; C - odorous; D - pungent; E - very pungent. The test results are shown in Table 2.

[0085]

[0086] The results above show that the odor of the photoinitiator used in this invention is far lower than that of commercially available water-based photoinitiator 2959.

[0087] (iv) Initiator migration test

[0088] To evaluate whether TM1 migrates after polymer curing, verify its initiation efficiency, and determine its stability, a comparison was made with the existing water-soluble photoinitiator 2959. The experimental methods are as follows:

[0089] Following the formulation and preparation method of Example 2, only the amount of photoinitiator TM1 prepared in Example 1 was changed to prepare a series of aqueous visible light curable compositions of the present invention. The amount of photoinitiator TM1 is shown in Table 3. The prepared aqueous visible light curable compositions were uniformly distributed on glass slides coated with silicone spacers with a thickness of 1 mm. Subsequently, the samples were placed at a wavelength of 405 nm and an intensity of 100 mW / cm. 2 Under the light source of LED light, the coating sample TM1 of Example 1 was obtained after 10 minutes.

[0090] Following the same method, TM1 was replaced with photoinitiator 2959 to prepare comparative samples, as shown in Table 3.

[0091] The cured film was cut into small pieces and pulverized into powder. 100 mg of the powder was dissolved in 2 mL of anhydrous ethanol. Samples were taken every 24 hours, with soaking times of 24 h, 48 h, and 72 h. The presence of photoinitiators in the soaking solution was detected using UV-Vis spectroscopy, and migration was assessed by detecting changes in characteristic absorption peaks.

[0092] The UV absorption spectrum of the initial anhydrous ethanol was detected using a UV spectrophotometer, yielding the absorbance A1 of the maximum absorption peak in the 350-450 nm range. The absorbance A2 of the maximum absorption peak in the 350-450 nm range was then detected using the same UV spectrophotometer. If the photoinitiator migrates into the immersion solution, the absorbance of the maximum absorption peak in the 350-450 nm range will decrease; that is, the absorbance of the photoinitiator that migrated into the solution is (A1-A2). The degree of photoinitiator migration is calculated, i.e., the migration rate A = (A1-A2) / A1. A larger value indicates a greater migration amount.

[0093] Evaluation criteria:

[0094] ○: Mobility A < 0.01;

[0095] ×: Mobility A > 0.01.

[0096] The test results are summarized in Table 3 below.

[0097] (v) Coating hardness test (pencil hardness test)

[0098] Test Method: Place the coating sample prepared in Test (IV) above on a hard, flat surface. Use a series of pencils of known hardness (from softest to hardest: 6B to 9H), sharpen the pencils to a lead of approximately 3-5 mm, and fix them in a pencil hardness tester at a 45° angle to the coating surface. Push the instrument forward at a speed of approximately 1 mm / s, allowing the pencil lead to scratch the coating surface. Start with a softer pencil and gradually replace it with a harder pencil until a pencil of a certain hardness grade can scratch the coating. The pencil hardness of the coating is defined as the highest hardness grade that failed to cut or scratch the coating.

[0099] (vi) Adhesion test (cross-cut test)

[0100] Test method: Using a new utility knife blade, cut six parallel cuts into the coating surface obtained in Test (IV) above, down to the substrate. Then, make the same number of vertical cuts at the same spacing to form 25 (5×5) squares of 1mm×1mm each. After removing debris, firmly adhere tape to the square area, and then quickly peel off the tape at a 90° angle. Check the coating peeling in the grid area.

[0101] Assessment rating: Adhesion rating is divided into 0-5 levels, where:

[0102] Grade 0: The cut edges are completely smooth, with no chips falling off (adhesion rate 100%).

[0103] Level 1: Slight peeling of the coating at the cut intersections, affecting less than 5% of the square area;

[0104] Level 2: The coating peels off along the edges and at the intersections of cuts, affecting an area of ​​5%-15%;

[0105] Level 3: Partial or large-area peeling of the coating, affecting an area of ​​15%-35%;

[0106] Level 4: Large areas of coating peel off, affecting 35%-65% of the area;

[0107] Level 5: The area of ​​detachment is greater than 65%.

[0108] Test Results: The coating prepared by the aqueous visible light curing composition of this invention showed a grade of 0 after cross-cut adhesion testing. This indicates that the coating prepared by the aqueous visible light curing composition of this invention has excellent adhesion to the substrate and is not prone to peeling or flaking under external stress, ensuring the long-term durability and reliability of the coating.

[0109]

[0110] The above experimental results show that: (1) the photoinitiator TM1 of the present invention has excellent solubility in water and is suitable for waterborne photocuring applications; (2) the photoinitiation efficiency experiment shows that TM1 has excellent initiation performance and fast photocuring speed, exhibiting high polymerization efficiency; (3) the photoinitiator TM1 hardly migrates in the cured polymer film, showing excellent migration resistance, indicating that TM1 is suitable for applications with strict requirements on the migration of photoinitiators; (4) the photocurable coating prepared by the visible light curing composition provided by the present invention not only has high surface hardness and can effectively resist mechanical damage, but also exhibits excellent adhesion to the substrate; (5) the photoinitiator TM1 of the present invention has no VOC volatilization.

[0111] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Those skilled in the art can make various modifications and alterations within the spirit and principles of the present invention, and any modifications, equivalent substitutions, or improvements within this scope should be considered as covered by the protection scope of the present invention.

Claims

1. An aqueous visible light curable composition, comprising, based on 100 parts by weight of the composition: Waterborne UV-curable resin A: 30-60 parts; Photoinitiator B: 0.1-5 parts; Additive C: 0.1-15 parts; and Water: Balance The photoinitiator B is sodium anthracene-9,10-dimethylene sulfate having the structure of formula (I): in, R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 Each is independently selected from one of hydrogen, C1-C12 alkyl, C3-C12 cycloalkyl, C2-C12 unsaturated hydrocarbon, C1-C12 alkoxy, C6-C12 aryl or aryloxy, C6-C12 aryl or aryloxy substituted with one or more C1-C6 alkyl groups, C6-C12 aryl or aryloxy substituted with one or more C1-C6 alkoxy groups, halogen, cyano, and nitro.

2. The aqueous visible light curable composition according to claim 1, wherein, The photoinitiator B is a compound TM1 having the following structure: 。 3. The aqueous visible light curable composition according to claim 1, wherein, The content of photoinitiator B is 0.1-3 parts by mass.

4. The aqueous visible light curable composition according to claim 3, wherein, The content of photoinitiator B is 0.5-2 parts by mass.

5. The aqueous visible light curable composition according to claim 1, wherein, The waterborne UV-curable resin A is selected from one or more of waterborne polyurethane acrylate, waterborne epoxy acrylate, and waterborne polyester acrylate.

6. The aqueous visible light curable composition according to claim 1, wherein, The additive C is selected from one or more of the following: defoamer, thickener, leveling agent, plasticizer, reactive diluent, dye, adhesion promoter, and polymerization inhibitor.

7. The aqueous visible light curable composition according to claim 6, wherein, The reactive diluent is selected from one or more of polyethylene glycol diacrylate, trimethylolpropane triacrylate, hydroxyethyl acrylate dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol butyl ether, and ethanol.

8. The aqueous visible light curable composition according to claim 1, wherein, The total amount of the auxiliary agent C is 0.5-10 parts by mass.

9. The application of the aqueous visible light curable composition according to any one of claims 1 to 8, characterized in that, Used to prepare light-cured coatings for wood, metal or plastic surfaces.

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