Coating composition containing a (poly)glycerin-based monomer

Abstract

To provide a composition for coating that enables substrates such as glass and plastic to have water-repellent and anti-fogging performances in a sustained manner.SOLUTION: A composition for coating contains: a (poly)glycerol monomer that has a (poly)glycerol skeleton with an average degree of polymerization of 1-100, with its end having a polymerizable functional group; and a water-repellent monomer.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a coating composition. [Background technology]

[0002] Substrates such as glass and plastics are highly transparent and are used for optical films, glass, lenses, etc. However, under high temperature and humidity conditions or conditions with large temperature differences, condensation forms on the substrate surface, causing cloudiness and impairing visibility, which is a problem.

[0003] A common method for preventing this fogging phenomenon is to prepare a coating film that imparts an anti-fogging effect to the surface of the substrate. For example, a method has been disclosed in which a solution containing a surfactant or a surfactant and a hydrophilic polymer is applied to the surface of the substrate to make the surface hydrophilic and prevent the formation of water droplets (Patent Document 1).

[0004] However, the anti-fogging composition of Patent Document 1 has a problem in that the coating has low water resistance due to its high hydrophilicity, and is lost when washed away with water. Another method is to improve the ability of water droplets to slide off by making the coating surface super-water-repellent (Patent Document 2), but this sometimes results in fine water droplets adhering to the coating surface, causing fogging. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 03-215589 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-219071 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a coating composition that has both water repellency and anti-fogging properties. [Means for solving the problem]

[0007] As a result of intensive research, the present inventors have found that the above-mentioned problems can be solved by a coating composition comprising a (poly)glycerin-based monomer (A) having a (poly)glycerin skeleton with an average degree of polymerization of 1 to 100 and a polymerizable functional group at its terminal, and a water-repellent monomer (B), and have thus completed the present invention. [Effects of the Invention]

[0008] The coating resin composition containing the (poly)glycerin-based monomer of the present invention imparts both water repellency and anti-fogging properties to substrates such as glass and plastics, and has excellent durability of the anti-fogging effect. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described below based on the embodiments, but the scope of the present invention is not limited to these embodiments, and modifications made within the scope of the present invention also fall within the scope of the present invention. Note that the range "to" includes the upper and lower limits.

[0010] The (poly)glycerin-based monomer (A) according to the present invention has a (poly)glycerin skeleton with an average degree of polymerization of 1 to 100 and has a polymerizable functional group at its terminal. Note that (poly)glycerin refers to glycerin or polyglycerin.

[0011] The average degree of polymerization of the (poly)glycerol according to the present invention is 1 to 100, preferably 2 to 20, and most preferably 2 to 15. Here, the average degree of polymerization is calculated from the hydroxyl value determined by terminal analysis using the following formulas (2) and (3). The hydroxyl value in formula (3) is a numerical value that indicates the number of hydroxyl groups contained in the (poly)glycerol, and refers to the number of milligrams of potassium hydroxide required to neutralize the acetic acid required to acetylate the free hydroxyl groups contained in 1 g of the (poly)glycerol. The number of milligrams of potassium hydroxide is calculated in accordance with "Standard Testing Methods for the Analysis of Fats, Oils and Related Materials, 2013 Edition, Established by the Japan Oil Chemists' Society," edited by the Japan Oil Chemists' Society. Molecular weight=74n+18 (2) Hydroxyl value = 56110(n + 2) / molecular weight (3)

[0012] The polymerizable functional group according to the present invention is not particularly limited, and examples thereof include an alkoxysilyl group, a silanol group, an alkenyl group such as an allyl group or a vinyl group, an alkenyloxy group such as an allyloxy group or a vinyloxy group, a (meth)acryloyl group, an epoxy group, an isocyanate group, etc. Among these, the effects of the present invention are more pronounced with an alkoxysilyl group, an allyl group, and a vinyl group.

[0013] The (poly)glycerin-based monomer (A) according to the present invention is preferably a reaction product obtained by reacting a (poly)glycerin or a (poly)glycerin derivative having a first reactive functional group at its terminal with a polymerizable compound having a second reactive functional group.

[0014] The (poly)glycerin or (poly)glycerin derivative having a first reactive functional group at its terminal is preferably a compound represented by the structure of the following formula (1).

[0015] [ka] (n, p, q, and r each represent the number of repeating units, n is an integer of 1 to 100, and p, q, and r each are integers of 0 to 50. AO represents an alkylene oxide having 1 to 4 carbon atoms. R1 may be the same or different and represents hydrogen or a reactive functional group having at its terminal any one selected from the group consisting of a thiol group, a (meth)acryloyl group, an epoxy group, and an allyl group.)

[0016] Examples of AO include ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO), with ethylene oxide (EO) being preferred. p, q, and r in formula (1) each represent the average number of alkylene oxides added per hydroxyl group of polyglycerol, and each is preferably 0 to 50, more preferably 1 to 20. The sum of p, q, and r (p+q+r) is more preferably 1 to 130, and even more preferably 5 to 120.

[0017] Specific examples of (poly)glycerin or (poly)glycerin derivatives having a first reactive functional group include (poly)glycerin, (poly)glycerin alkylene oxide adducts, (poly)glycerin (alkylene oxide) thioglycolic acid esters, (poly)glycerin (alkylene oxide) 3-mercaptopropionic acid esters, (poly)glycerin (alkylene oxide) (meth)acrylates, (poly)glycerin (alkylene oxide) (poly)glycidyl ethers, and (poly)glycerin (alkylene oxide) (poly)allyl ethers.

[0018] The second reactive functional group is not particularly limited, and examples thereof include a vinyl group, an allyl group, an isocyanate group, a thiol group, a (meth)acryloyl group, an epoxy group, a hydroxyl group, an amino group, and a hydrosilyl group. Examples of polymerizable compounds having a second reactive functional group include vinyltrimethoxysilane, vinyltriethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and N-2-(aminoethyl)-3-aminopropyl. Examples of such silanes include methyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-aminopropyltriethoxysilane, trimethoxysilane, triethoxysilane, dimethoxymethylsilane, diethoxymethylsilane, allyl glycidyl ether, diallylglycidylglycerin, allylglycidyl phthalate, allylglycidyl hexahydrophthalate, 1,2-epoxy-4-vinylcyclohexane, allyl mercaptan, polyethylene glycol allyl ether, polyethylene glycol diallyl ether, allyl dimethylamine, and diallylmethylamine.

[0019] The (poly)glycerin-based monomer (A) of the present invention is preferably obtained by reacting a first reactive functional group contained at the terminal of (poly)glycerin or a (poly)glycerin derivative with a second reactive functional group contained in a polymerizable compound. Furthermore, it is obtained by reacting a second reactive functional group at the terminal of a polymerizable compound. Specific examples include reaction products of (poly)glycerin, (poly)glycerin alkylene oxide adducts, or (poly)glycerin derivatives having thiol groups at their terminals with polymerizable compounds having any of vinyl, isocyanate, epoxy, and amino groups; reaction products of (poly)glycerin derivatives having (meth)acryloyl or allyl groups at their terminals with polymerizable compounds having any of vinyl, allyl, thiol, (meth)acryloyl, and hydrosilyl groups; and reaction products of (poly)glycerin derivatives having epoxy groups at their terminals with polymerizable compounds having any of thiol, hydroxyl, and hydrosilyl groups. In the resulting reaction product, it is preferable that 20 to 100% of the first reactive functional groups of the (poly)glycerin or (poly)glycerin derivative are reacted and bonded, and it is more preferable that 50 to 100% of the first reactive functional groups are reacted and bonded.

[0020] The water-repellent monomer (B) of the present invention is a water-repellent monomer containing at least one of a fluorine-based compound and a silicone-based compound, such as an acrylate having a fluoroalkyl group, a fluoroalkyl ether group, or a fluoroalkenyl group, a silane, a siloxane, an alkoxysilane, a methoxy group-containing silicone resin, a methyl-based silicone resin, or a methylphenyl-based silicone resin.

[0021] The molecular weight of (B) is not particularly limited and can be appropriately selected depending on the purpose.

[0022] The amount of (B) in the coating composition of the present invention is 0.01% by mass or more and 10% by mass or less, preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 1% by mass or less, relative to (A). When the amount of (B) is 0.01% by mass or more, water repellency is exhibited. Furthermore, when the amount of (B) is 10% by mass or less, whitening or clouding does not occur on the coating film surface, and excellent anti-fogging properties are achieved.

[0023] The coating composition of the present invention may contain silicate monomers such as TMOS and TEOS, silicate oligomers such as methyl silicate and ethyl silicate, polysilsesquioxane, etc., within the range that does not impair the effects of the present invention.

[0024] The coating composition of the present invention may further contain other additives, such as ultraviolet absorbers, colorants, pigments, antioxidants, anti-yellowing agents, bluing agents, antifoaming agents, thickeners, anti-settling agents, antistatic agents, surfactants, adhesion promoters, infrared absorbers, and light stabilizers.

[0025] Furthermore, the coating composition of the present invention may be mixed with an organic solvent. For example, alcohols include methanol, ethanol, butanol, isobutanol, isopropyl alcohol, propanol, t-butanol, sec-butanol, and benzyl alcohol; ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, and diacetone alcohol; esters include ethyl acetate, methyl acetate, butyl acetate, sec-butyl acetate, methoxybutyl acetate, amyl acetate, propyl acetate, isopropyl acetate, ethyl lactate, methyl lactate, and butyl lactate; ethers include isopropyl ether, methyl cellosolve, ethyl cellosolve, and butyl cellosolve; glycols include ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol; and glycol esters include ethylene glycol. Examples of the glycol ethers include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, butyl diglycol, methyl triglycol, 1-methoxy-2-propanol, propylene glycol monobutyl ether, 3-methoxy-3-methyl-1-butanol, diethylene glycol monohexyl ether, propylene glycol monomethyl ether propionate, dipropylene glycol methyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, and diethylene glycol diethyl ether. Examples of the aromatic hydrocarbons include benzene, toluene, and xylene. These organic solvents can be used alone or in combination of two or more.

[0026] The coating composition of the present invention can be applied to various substrates and cured to produce a cured coating film. The curing method is not particularly limited, and known methods such as photocuring, thermal curing, and curing by sol-gel reaction can be used depending on the reactive groups of the coating composition.

[0027] When the coating composition of the present invention is cured by light or heat, it is preferable to use a polymerization initiator.

[0028] The photopolymerization initiator is not particularly limited, and examples thereof include benzil ketals such as 2,2-dimethoxy-1,2-diphenylethan-1-one, α-hydroxyacetophenones such as 1-hydroxycyclohexyl phenyl ketone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one, aminoacetophenones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, acylphosphine oxides such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and monoacylphosphine oxide, benzoin, benzoin methyl photoradical polymerization initiators such as benzoins such as benzoin ether, benzoin ethyl ether, benzoin butyl ether, and benzoin isopropyl ether; benzophenones such as benzophenone, methylbenzophenone, 4,4'-bisdiethylaminobenzophenone, and 4-benzoyl-4'-methyldiphenyl sulfide; and thioxanthones such as 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2-isopropylthioxanthone; photocationic polymerization initiators (photoacid generators) such as onium salt-based compounds such as diazonium salts, iodonium salts, sulfonium salts, and phosphonium salts; organometallic complexes typified by iron arene complexes; and photoanionic polymerization initiators (photobase generators) such as oxime ester-based compounds, ammonium-based compounds, benzoin-based compounds, dimethoxybenzyl urethane-based compounds, and orthonitrobenzyl urethane-based compounds. The amount of the photopolymerization initiator used is not particularly limited, but is generally preferably 0.1 to 10 parts by weight per 100 parts by weight of the total amount of the (poly)glycerin-based monomer and the water-repellent monomer that constitute the coating composition.

[0029] Examples of the thermal polymerization initiator include thermal radical polymerization initiators such as azo compounds typified by 2,2'-azobisbutyronitrile (AIBN) and peroxides typified by benzoyl peroxide (BPO), and thermal cationic polymerization initiators such as benzenesulfonate esters and alkylsulfonium salts. The amount of the thermal polymerization initiator used is not particularly limited, but generally, 0.1 to 20 parts by weight is preferred per 100 parts by weight of the total amount of the (poly)glycerin-based monomer and water-repellent monomer that constitute the coating composition.

[0030] When the coating composition of the present invention is cured by a sol-gel reaction, water is added as necessary for the hydrolysis of the metal alkoxide. It is also preferable to use a catalyst to promote the hydrolysis of the metal alkoxide and the polycondensation reaction. Such a catalyst may be an acid catalyst or an alkali catalyst used in conventional sol-gel processes. Examples of acid catalysts include hydrochloric acid, nitric acid, sulfuric acid, formic acid, organic acids, and photoacid generators. Examples of alkali catalysts include inorganic base compounds such as metal hydroxides and ammonia, organic base compounds such as amines and phosphines, and photobase generators.

[0031] The coating composition of the present invention can be suitably used as a water-repellent and anti-fogging agent, an anti-condensation agent, or a stress relaxation agent. A cured coating film obtained by curing such a coating composition has excellent anti-fogging properties for substrates such as glass and plastic, and is suitably used as an anti-fogging coating agent for automobile windshields, lamp covers, camera lenses, goggles, etc. [Example]

[0032] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0033] [Synthesis Example 1] A reaction vessel equipped with a thermometer and a stirrer was charged with 425 g of tetraglycerin EO 60 mole adduct, 210 g of 3-isocyanatepropyltriethoxysilane (manufactured by TCI), and 0.13 g of dibutyltin dilaurate, and the mixture was stirred at 40°C for 4 hours to obtain 635 g of compound (A1). Note that 100% of the hydroxyl groups at the terminals of the polyglycerin derivative were reacted.

[0034] [Synthesis Example 2] A reaction vessel equipped with a thermometer and a stirrer was charged with 80 g of tetraglycerin EO 60 mole adduct, 20 g of 3-isocyanatepropyltriethoxysilane (manufactured by TCI), and 0.01 g of dibutyltin dilaurate, and the mixture was stirred at 60°C for 6 hours to obtain 100 g of compound (A2). Note that 50% of the hydroxyl groups at the terminals of the polyglycerin derivative were reacted.

[0035] [Synthesis Example 3] A reaction vessel equipped with a thermometer and a stirrer was charged with 37 g of tetraglycerin EO 12 mole adduct, 63 g of 3-isocyanatepropyltriethoxysilane (manufactured by TCI), and 0.01 g of dibutyltin dilaurate, and the mixture was stirred at 60°C for 5 hours to obtain 100 g of compound (A3). Note that 100% of the hydroxyl groups at the terminals of the polyglycerin derivative were reacted.

[0036] [Synthesis Example 4] A reaction vessel equipped with a thermometer and a stirrer was charged with 66 g of diglycerin EO 40 mole adduct, 34 g of 3-isocyanatepropyltriethoxysilane (manufactured by TCI), and 0.01 g of dibutyltin dilaurate, and the mixture was stirred at 60°C for 12 hours to obtain 100 g of compound (A4). Note that 100% of the hydroxyl groups at the terminals of the polyglycerin derivative were reacted.

[0037] [Synthesis Example 5] A reaction vessel equipped with a thermometer and a stirrer was charged with 66 g of a 120 mole EO adduct of decaglycerin, 34 g of 3-isocyanatepropyltriethoxysilane (manufactured by TCI), and 0.01 g of dibutyltin dilaurate, and the mixture was stirred at 40°C for 4 hours to obtain 100 g of compound (A5). Note that 100% of the hydroxyl groups at the terminals of the polyglycerin derivative were reacted.

[0038] [Synthesis Example 6] A reaction vessel equipped with a thermometer, stirrer, and Dean-Stark apparatus was charged with 764 g of tetraglycerin (polyglycerin with an average degree of polymerization of 4) with 60 moles of EO, 163 g of 3-mercaptopropionic acid, 900 g of toluene, and 45 g of p-toluenesulfonic acid. The mixture was heated to a toluene reflux atmosphere with stirring, and a dehydration condensation reaction was carried out over approximately 6 hours. After completion of the reaction, the mixture was neutralized with sodium bicarbonate and extracted with ethyl acetate:toluene = 50:50. The organic layer was distilled under reduced pressure to obtain 367 g of the 3-mercaptopropionic acid ester of the tetraglycerin with 60 moles of EO. A reaction vessel equipped with a stirrer was charged with 319 g of the 3-mercaptopropionic acid ester of the tetraglycerin with 60 moles of EO and 81 g of vinyltrimethoxysilane, and the mixture was stirred for 45 minutes while irradiating with UV light, obtaining 400 g of compound (A6). In addition, 100% of the hydroxyl groups at the terminals of the polyglycerin derivative were reacted.

[0039] [Synthesis Example 7] A reaction vessel equipped with a thermometer and a stirrer was charged with 10 g of tetraglycerin with 12 moles of EO, 16.7 g of 50% aqueous thorium hydroxide solution, and 2.24 g of tetrabutylammonium bromide, and the mixture was stirred at 40°C. 25.3 g of allyl bromide was added dropwise, and the mixture was stirred for 22 hours while heating at 40°C. After the reaction was completed, the mixture was extracted with toluene, and the solvent was distilled off under reduced pressure to synthesize the allyl ether of tetraglycerin with 12 moles of EO. Next, 10.0 g of the allyl ether of tetraglycerin with 12 moles of EO and 6.22 g of triethoxysilane were charged, and the mixture was stirred at room temperature in the presence of a Karstedt's catalyst, yielding 16 g of compound (A7).

[0040] [Synthesis Example 8] A screw tube was charged with 9.10 g of silicon-containing fluororesin, 32.2 g of ethyl acetate, 0.28 g of 3-isocyanatepropyltriethoxysilane (manufactured by TCI), and 100 ppm (relative to the theoretical yield) of dibutyltin dilaurate, and the mixture was stirred at 40°C for 24 hours to obtain 42 g of compound (B1) with a concentration of 5 wt%.

[0041] Example 1 A coating composition was obtained by uniformly mixing 1.0 g of compound (A1), 0.20 g of a 5 wt% ethyl acetate solution of compound (B1), 1.0 g of 1-methoxy-2-propanol, 0.37 g of water, and 0.3 g of formic acid under stirring. The coating composition was then applied to a hydrophilically treated glass plate (76 mm × 52 mm × 1.2 mm), air-dried at room temperature for 1 hour, and then heated and dried at 150 °C for 30 minutes to obtain a cured coating film with a thickness of approximately 27 μm. The glass plate was then hydrophilically treated by immersion in an alkaline solution (a mixture of 500 mL of isopropanol, 41.6 g of potassium hydroxide, and 83.3 g of ion-exchanged water) for 15 hours and then washed with 0.2 mol / L hydrochloric acid solution and ion-exchanged water.

[0042] The resulting cured coating films were evaluated for water repellency and anti-fogging properties as follows. (water repellency) Water repellency was evaluated by measuring the water contact angle of the cured coating surface. Using a contact angle measuring device (Drop Master DM500, manufactured by Kyowa Interface Science Co., Ltd.), 1 μL of ion-exchanged water was dropped onto the cured coating, and the contact angle was measured 60 seconds after the drop. (Anti-fogging) The cured coating film was placed 2.0 cm above the surface of water adjusted to 50°C, and the cured coating film was visually evaluated for cloudiness, and the time it took for the coating film to become cloudy was measured.

[0043] <Examples 2 to 7> Coating compositions and cured coating films were prepared in the same manner as in Example 1, except that the compound (A1) used in Example 1 was changed to compounds (A2) to (A7) and the amount of water was changed accordingly, and the water repellency and anti-fogging properties were evaluated.

[0044] Example 8 A coating composition and a cured coating film were prepared in the same manner as in Example 1, except that the amount of compound (B1) added in Example 1 was changed from 1 part to 0.3 parts, and the amount of water was changed accordingly, and the water repellency and anti-fogging properties were evaluated.

[0045] Example 9 A coating composition and a cured coating film were prepared in the same manner as in Example 1, except that the amount of compound (B1) added in Example 1 was changed from 1 part to 2 parts, and the amount of water was changed accordingly, and the water repellency and anti-fogging properties were evaluated.

[0046] <Reference example 1> 1.0 g of compound (A1), 1.0 g of 1-methoxy-2-propanol, 0.37 g of water, and 0.3 g of formic acid were uniformly mixed and stirred to obtain a coating composition. The coating composition was then applied to a hydrophilically treated glass plate (76 mm × 52 mm × 1.2 mm), air-dried at room temperature for 1 hour, and then heated and dried at 150 ° C for 30 minutes to obtain a cured coating film with a film thickness of approximately 30 μm. The water repellency and anti-fogging properties of the obtained cured coating film were evaluated in the same manner as in Examples 1 to 9.

[0047] The blending compositions and evaluation results of Examples 1 to 9 and Reference Example 1 are shown in Tables 1 and 2.

[0048] [Table 1]

[0049] [Table 2]

[0050] Example 1, which is a cured coating film of a coating composition comprising the (poly)glycerin-based monomer (A) and the water-repellent monomer (B) of the present invention, had higher water repellency and anti-fogging properties than Reference Example 1, which comprises only the (poly)glycerin-based monomer (A). It was also confirmed that similar performance could be obtained in Examples 2 to 7, in which the structure of the (poly)glycerin-based monomer (A) was modified. Furthermore, similar effects were obtained when the amount of water-repellent monomer (B) added was changed. From the above evaluation results, it became clear that the cured coating film obtained from the coating composition of the present invention has moisture absorbing and releasing properties, achieving both water repellency and anti-fogging properties.

Claims

1. a (poly)glycerin-based monomer (A) having a (poly)glycerin skeleton with an average degree of polymerization of 1 to 100 and a polymerizable functional group at its terminal; A water-repellent monomer (B) containing at least one of a fluorine-based compound and a silicone-based compound. A coating composition comprising: one of the polymerizable functional groups is an alkoxysilyl group, an allyl group, or a vinyl group; The blending amount of (B) relative to (A) is 0.01% by mass or more and 10% by mass or less. A coating composition comprising:

2. 2. The coating composition according to claim 1, wherein (A) is a reaction product obtained by reacting (poly)glycerin or a (poly)glycerin derivative having a first reactive functional group at an end with a polymerizable compound having a second reactive functional group, and wherein the first reactive functional group is reacted with the second reactive functional group.

3. 3. The coating composition according to claim 2, wherein the (poly)glycerin or (poly)glycerin derivative having a first reactive functional group at an end thereof is represented by the following formula (1): 【Chemical 1】 (n, p, q, and r each represent the number of repeating units, n is an integer of 1 to 100, and p, q, and r each are integers of 0 to 50. AO represents an alkylene oxide having 1 to 4 carbon atoms. R1 may be the same or different and represents hydrogen or a reactive functional group having at its terminal any one selected from the group consisting of a thiol group, a (meth)acryloyl group, an epoxy group, and an allyl group.)

4. 3. The coating composition according to claim 2, wherein the second reactive functional group is one selected from the group consisting of a vinyl group, an allyl group, an isocyanate group, a thiol group, a (meth)acryloyl group, an epoxy group, an amino group, and a hydrosilyl group.

5. A cured product formed by curing the coating composition according to any one of claims 1 to 4.

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