Antifogging agent composition and antifogging product

Abstract

The present application provides an antifogging agent composition containing a copolymer (A), colloidal silica (B), and a solvent (C), (A) being a (meth)acrylate copolymer obtained from a monomer mixture containing monomers (a-1) to (a-3), (C) containing water (C-1), a monohydric alcohol solvent (C-2) having 1 to 4 carbon atoms, a solvent (C-3) having a boiling point of 100°C or higher and 200°C or lower and having at least one functional group selected from the group consisting of a ketone group, an ester group, two or more ether groups, a thione group, and an amide group in the molecule, an alcohol ether solvent (C-4) represented by general formula (5): R 10 -O-R 11 -OH, the total of (C-1) to (C-4) and the mass ratio of (C-3) and (C-4) being a specific amount relative to 100 parts by mass of the total of (A) and (B). The antifogging agent composition can form an antifogging coating film that is excellent in transparency, water resistance, initial adhesion, antifogging properties, and repeated antifogging properties, is less likely to produce sag marks, can suppress liquid sagging at the time of coating, has adhesion after pre-drying when coated as a thin film, and can suppress cracking when coated as a thick film.

Description

TECHNICAL FIELD

[0001] The present application relates to an antifog agent composition and an antifog property product. BACKGROUND

[0002] In a vehicle lamp such as a headlamp of an automobile, sometimes high-humidity air enters a lamp chamber, a lens is cooled by external air or rain, and water condenses on the inner surface to generate fog. As a result, there is a problem that the brightness of the vehicle lamp decreases, and the appearance of the lens surface is damaged, thereby causing discomfort to the user. In order to prevent such fog of the lens, a method of forming an antifog coating film by applying an antifog agent to a site where fog is generated is known (Patent Documents 1 to 3). It is generally required that the antifog coating film has transparency and water resistance, and does not cause liquid sagging at the time of application.

[0003] For example, Patent Document 1 discloses an antifog agent composition containing a specific copolymer, a surfactant, and an acid catalyst. Further, Patent Document 2 discloses an antifog agent composition containing a specific copolymer, specific silica particles, and a hydrolysis condensate of a specific siloxane compound. Further, Patent Document 3 discloses an antifog agent composition containing a hydrophilic compound and a metal oxide.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-6881

[0007] Patent Document 2: Japanese Patent Application Publication No. 2018-2865

[0008] Patent Document 3: International Publication No. 2019 / 163918 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] For the antifog coating film, if a water film is formed on the surface of the antifog coating film due to a water-soluble component such as a surfactant, sometimes a phenomenon that water in the water film locally flows down (sagging) occurs. If water-soluble components in the antifog coating film dissolve in the water film, sagging occurs and the water evaporates, and then the dissolved water-soluble components are precipitated on the surface of the antifog coating film, and the shape of the sagging trace remains, which causes a problem of appearance failure of the vehicle lamp. Further, sometimes the antifog property when a water film is repeatedly formed in the lens (repeated antifog property) decreases.

[0011] The antifogging agent composition disclosed in Patent Document 1 has a repeated antifogging property and can make sag marks unnoticeable by using a specific (meth)acrylate copolymer and a specific surfactant, but if the surfactant is added in a large amount in order to impart a high antifogging property, sag marks are sometimes generated.

[0012] Further, the antifogging agent compositions disclosed in Patent Documents 2 and 3 suppress the generation of sag marks by compounding inorganic components with organic components, but when a large amount of inorganic components are contained, there are technical problems of causing agglomeration between the inorganic components, a decrease in transparency of a coating film, or a decrease in repeated antifogging property.

[0013] On the other hand, when the antifogging agent is applied to a headlamp lens or the like of an automobile, in order to obtain a smooth antifogging coating film, pre-drying is sometimes performed after the application, or when the application is performed to a lens having a complex shape, it is sometimes difficult to perform the application with a uniform film thickness, and a portion to which a thick film is applied is generated.

[0014] When the application is performed under the above conditions, the antifogging agent compositions disclosed in Patent Documents 2 and 3 have technical problems of a decrease in adhesion after pre-drying when applied in a thin film, and a technical problem of generation of cracks (a phenomenon of cracking of an antifogging coating film and generation of a crack) on a portion to which a thick film is applied.

[0015] In view of the above, an object of the present application is to provide an antifogging agent composition which can form an antifogging coating film excellent in transparency, water resistance, initial adhesion, antifogging property, and repeated antifogging property, is less likely to generate sag marks, can suppress liquid sagging at the time of application, has adhesion after pre-drying when applied in a thin film, and can suppress cracks when applied in a thick film.

[0016] Technical means for solving the technical problem

[0017] That is, the present application relates to an antifogging agent composition containing a copolymer (A), colloidal silica (B), and a solvent (C), wherein the copolymer (A) is a (meth)acrylate copolymer obtained from a monomer mixture containing a monomer (a-1) represented by General Formula (1), a monomer (a-2) represented by General Formula (2), and one or more kinds of monomers (a-3) selected from the group consisting of a monomer having a hydroxyl group represented by General Formula (3) and a monomer having a hydroxyl group represented by General Formula (4).

[0018] [Chemical Formula 1]

[0019]

[0020] In General Formula (1), R 1 is a hydrogen atom or a methyl group, R 2 and R 3independently a hydrogen atom or a straight chain or branched alkyl group having 1 to 4 carbon atoms.

[0021] [Chemical Formula 2]

[0022]

[0023] in General Formula (2), R 4 is a hydrogen atom or a methyl group, and R 5 is a hydrogen atom or a straight chain or branched alkyl group having 1 to 8 carbon atoms.

[0024] [Chemical Formula 3]

[0025]

[0026] in General Formula (3), R 6 is a hydrogen atom or a methyl group, and R 7 is a straight chain or branched alkylene group having 1 to 8 carbon atoms.

[0027] [Chemical Formula 4]

[0028]

[0029] in General Formula (4), R 8 is a hydrogen atom or a methyl group, and R 9 is a straight chain or branched alkylene group having 2 to 8 carbon atoms.

[0030] The solvent (C) contains: water (C-1), a monohydric alcohol-based solvent (C-2) having 1 to 4 carbon atoms, a solvent (C-3) having at least one functional group selected from the group consisting of a ketone group, an ester group, two or more ether groups, a thione group, and an amide group in the molecule, and having a boiling point of 100°C or higher and 200°C or lower at one standard atmosphere, and an alcohol ether-based solvent (C-4) represented by General Formula (5): R 10 -O-R 11 -OH, in General Formula (5), R 10 is a straight chain or branched alkyl group having 1 or more and 8 or less carbon atoms, R 11 is a straight chain or branched alkylene group having 2 or more and 5 or less carbon atoms, and R 10 is a straight chain or branched alkyl group having 1 or more and 5 or less carbon atoms, and the total number of carbon atoms of R 11 is 3 or more and 12 or less, the total of the water (C-1), the solvent (C-2), the solvent (C-3), and the solvent (C-4) is 550 to 1350 parts by mass with respect to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B), and the mass ratio ((C-3) / (C-4)) of the solvent (C-3) and the solvent (C-4) is 0.3 to 15.

[0031] Further, the present application relates to an antifogging product having an antifogging coating film formed of the antifogging agent composition on a substrate.

[0032] Effects of the Invention

[0033] Details of the mechanism of the effects of the antifogging agent composition of the present application are not yet fully understood, but are presumed as follows. However, the present application is not limited by this mechanism of action.

[0034] The antifogging agent composition of the present application contains the copolymer (A), the colloidal silica (B), and the solvent (C). The copolymer (A) contains the monomers (a-1) to (a-3), and thus improves the antifogging property of the antifogging coating film based mainly on the monomer (a-1), and reduces the water solubility of the copolymer (A) by forming a crosslinked structure on the antifogging coating film based on the monomer (a-2), thereby making it difficult to generate sag marks, improves the compatibility of the copolymer (A) with the colloidal silica (B) based on the monomer (a-3), and the copolymer (A) and the silica form a firm antifogging coating film via non-covalent bonds, thereby improving the water resistance of the antifogging coating film, and exhibiting the performance of making it difficult to generate sag marks. The colloidal silica (B) improves the hydrophilicity (antifogging property) of the antifogging coating film due to the hydrophilic groups on the surface and inside of the silica, and reduces the water solubility of the antifogging coating film after film formation by the inter-particle cohesion between the silicas, thereby making it difficult to generate sag marks, and exhibiting the performance of improving the water resistance. The solvent (C) contains the (C-1) to (C-4), and thus improves the solubility of the copolymer (A) based mainly on water (C-1), and improves the transparency of the antifogging coating film by suppressing the whitening of the antifogging coating film due to the aggregation of the copolymer (A), improves the volatility of the solvent (C) based on the monohydric alcohol solvent (C-2) having a high volatility and a carbon number of 1 to 4, suppresses the liquid sagging during coating by the increase in the solid content and the viscosity at the time of coating the substrate at the time of coating the antifogging agent composition, improves the adhesion after pre-drying at the time of thin film coating based on the solvent (C-3) having a specific functional group exhibiting permeability to the substrate (polycarbonate, polymethyl methacrylate), and alleviates the substrate permeability of the solvent (C-3) based on the alcohol ether solvent (C-4) not exhibiting permeability to the substrate (polycarbonate, polymethyl methacrylate) and having a high boiling point, and thus can suppress the generation of cracks at the time of thick film coating. Further, by containing the (C-1) to (C-4) in specific amounts improving the solubility of the copolymer (A) and the dispersibility of the colloidal silica (B), the whitening of the antifogging coating film due to the aggregation of the copolymer (A) and the aggregation of the silica is suppressed, and thus an antifogging coating film having a high transparency can be obtained. DETAILED DESCRIPTION

[0035] The antifogging agent composition of the present application contains the copolymer (A), the colloidal silica (B), and the solvent (C).

[0036] <Co-polymer (A)>

[0037] The co-polymer (A) of the present application is a (meth) acrylate co-polymer obtained from a monomer mixture containing the following monomer (a-1), monomer (a-2) and monomer (a-3).

[0038] <Monomer (a-1)>

[0039] The monomer (a-1) is represented by the following general formula (1):

[0040] [Chemical Formula 5]

[0041]

[0042] In the general formula (1), R 1 is a hydrogen atom or a methyl group, R 2 and R 3 are independently a hydrogen atom or a straight chain or branched chain alkyl group having a carbon number of 1 to 4.

[0043] The monomer (a-1) mainly has a function of improving the hydrophilicity of the co-polymer (A) and improving the anti-fogging property of the anti-fogging coating film. As the monomer (a-1), for example, acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N,N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N,N-dimethyl (meth) acrylamide, N,N-diethyl (meth) acrylamide and the like can be exemplified. From the viewpoint of the anti-fogging property and the excellent adhesion of the anti-fogging coating film to the substrate, N,N-dimethyl (meth) acrylamide is preferred. The monomer (a-1) can be used alone or in combination of two or more.

[0044] <Monomer (a-2)>

[0045] The monomer (a-2) is represented by the following general formula (2):

[0046] [Chemical Formula 6]

[0047]

[0048] In the general formula (2), R 4 is a hydrogen atom or a methyl group, and R 5 is a hydrogen atom or a straight chain or branched chain alkyl group having a carbon number of 1 to 8.

[0049] The monomer (a-2) mainly has the function of cross-linking between molecules by dehydration condensation reaction between N-hydroxymethyl or N-hydroxymethyl ether group, and dealcoholization of N-hydroxymethyl or N-hydroxymethyl ether group with hydroxyl group, forming cross-linked structure with the copolymer (A) to reduce water solubility of the copolymer (A), thereby not easily generating sagging marks. As the monomer (a-2), for example, N-hydroxymethyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-isobutoxymethyl (meth) acrylamide, and the like can be exemplified. From the viewpoint of not easily generating sagging marks of the antifog agent composition, N-hydroxymethyl (meth) acrylamide is preferred. The monomer (a-2) can be used alone or in combination of two or more.

[0050] <Monomer (a-3)>

[0051] The monomer (a-3) is one or more selected from the group consisting of a monomer having a hydroxyl group represented by the following general formula (3) and a monomer having a hydroxyl group represented by the following general formula (4).

[0052] [Chemical Formula 7]

[0053]

[0054] In the general formula (3), R 6 is a hydrogen atom or a methyl group, and R 7 is a linear or branched alkylene group having 1 to 8 carbon atoms.

[0055] [Chemical Formula 8]

[0056]

[0057] In the general formula (4), R 8 is a hydrogen atom or a methyl group, and R 9 is a linear or branched alkylene group having 2 to 8 carbon atoms.

[0058] The monomer (a-3) mainly has the function of forming a firm antifog coating film by improving the compatibility of the copolymer (A) with the colloidal silica (B), thereby having the performance of exhibiting no easy occurrence of sagging marks while improving the water resistance of the antifog coating film. As the monomer (a-3), for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, N-(2-hydroxyethyl) (meth) acrylamide, 4-hydroxybutyl (meth) acrylamide, and the like can be exemplified. From the viewpoint of excellent water resistance of the antifog coating film, 2-hydroxyethyl (meth) acrylate and N-(2-hydroxyethyl) (meth) acrylamide are preferred. The monomer (a-3) can be used alone or in combination of two or more.

[0059] The content of the monomer (a-1) in the monomer mixture is preferably 30 to 80% by mass. From the viewpoint of improving the antifog property of the copolymer and the transparency of the antifog coating film, the content of the monomer (a-1) in the monomer mixture is more preferably 40% by mass or more, and further preferably 50% by mass or more. In addition, from the viewpoint of suppressing the water solubility of the copolymer (A) and improving the water resistance, the content of the monomer (a-1) in the monomer mixture is more preferably 75% by mass or less, and further preferably 65% by mass or less. That is, from the viewpoint of improving the antifog property of the copolymer and the transparency of the antifog coating film, suppressing the water solubility of the copolymer (A), and improving the water resistance, the content of the monomer (a-1) in the monomer mixture is more preferably 40% by mass or more and 75% by mass or less, and further preferably 50% by mass or more and 65% by mass or less.

[0060] The content of the monomer (a-2) in the monomer mixture is preferably 5 to 35% by mass. From the viewpoint of forming a crosslinked structure of the copolymer (A) and not easily occurring of sagging marks, the content of the monomer (a-2) in the monomer mixture is more preferably 10% by mass or more, and further preferably 15% by mass or more. In addition, from the viewpoint of improving the transparency of the antifog coating film and the adhesion to the substrate, the content of the monomer (a-2) in the monomer mixture is more preferably 30% by mass or less, and further preferably 25% by mass or less. That is, from the viewpoint of forming a crosslinked structure of the copolymer (A), not easily occurring of sagging marks, and improving the transparency of the antifog coating film and the adhesion to the substrate, the content of the monomer (a-2) in the monomer mixture is more preferably 10% by mass or more and 30% by mass or less, and further preferably 15% by mass or more and 25% by mass or less.

[0061] The content of the monomer (a-3) in the monomer mixture is preferably 5 to 35% by mass. From the viewpoint of improving the water resistance of the antifog coating film, the content of the monomer (a-3) in the monomer mixture is more preferably 10% by mass or more, and further preferably 15% by mass or more. In addition, from the viewpoint of improving the transparency and adhesion to the substrate of the antifog coating film, the content of the monomer (a-3) in the monomer mixture is more preferably 30% by mass or less, and further preferably 25% by mass or less. That is, from the viewpoint of improving the water resistance of the antifog coating film, improving the transparency and adhesion to the substrate of the antifog coating film, the content of the monomer (a-3) in the monomer mixture is more preferably 10% by mass or more and 30% by mass or less, and further preferably 15% by mass or more and 25% by mass or less.

[0062] <Method for producing (meth)acrylate copolymer>

[0063] The (meth)acrylate copolymer is obtained by copolymerizing the monomer mixture. As the structure of the copolymer, any one of random copolymer, alternating copolymer, block copolymer, and graft copolymer can be used, and from the viewpoint of being able to easily produce the antifog agent composition while being able to improve the effects of the antifog agent composition, which are primarily antifog properties, a random copolymer is preferred. As the polymerization method for obtaining the copolymer, various known polymerization methods such as radical polymerization, cationic polymerization, anionic living polymerization, cationic living polymerization, and the like can be used, and from the viewpoint of ease of industrial productivity and performance in many aspects, radical polymerization is preferred. As the radical polymerization, general bulk polymerization, suspension polymerization, solution polymerization, emulsion polymerization, and the like can be used, and from the viewpoint of being able to directly use the polymerization product as the antifog agent composition, solution polymerization is preferred.

[0064] As the polymerization solvent for the solution polymerization, for example, alcoholic solvents such as water, methanol, ethanol, 1-propanol, 2-propanol, diacetone alcohol, and the like; glycolic solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, 3-methoxybutanol, 3-methoxy-3-methylbutanol, and the like; ketonic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and the like; etheric solvents such as tetrahydrofuran, dioxane, and the like; ester solvents such as methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl lactate, ethyl lactate, and the like; aromatic solvents such as benzene, toluene, xylene, and the like; amide solvents such as formamide, dimethylformamide, and the like; and the like can be used. Among these, water, alcoholic solvents, and glycolic solvents are preferred. The polymerization solvent can be used alone or two or more kinds can be used simultaneously.

[0065] The radical polymerization initiator can use an organic peroxide, an azo compound, or the like that is generally used. As the organic peroxide, for example, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-hexanoate, t-butyl peroxypivalate, t-hexyl peroxypivalate, or the like can be exemplified. As the azo compound, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), or the like can be exemplified. The radical polymerization initiator can be used alone or two or more kinds can be used simultaneously.

[0066] The amount of the radical polymerization initiator added is preferably 0.01 to 5 parts by mass relative to 100 parts by mass of the monomer mixture. In terms of easy control of the heat of polymerization, it is preferable to add the radical polymerization initiator dropwise into the reaction vessel while performing the polymerization. The temperature at which the polymerization reaction is performed can be appropriately changed depending on the kind of the radical polymerization initiator used, but for industrial production, it is preferably 30 to 150°C, more preferably 40 to 100°C.

[0067] From the viewpoint of imparting water resistance to the anti-fog coating film, the number average molecular weight (Mn) of the (meth)acrylate copolymer is preferably 3,000 or greater, more preferably 10,000 or greater, and further preferably 50,000 or greater. From the viewpoint of increasing the viscosity of the anti-fog agent composition and suppressing liquid sagging, the number average molecular weight (Mn) of the (meth)acrylate copolymer is preferably 500,000 or less, more preferably 300,000 or less, and further preferably 200,000 or less.

[0068] The number average molecular weight (Mn) of the (meth)acrylate copolymer can be found by the GPC method.

[0069] <Measurement conditions for number average molecular weight (Mn)>

[0070] Analytical device: HLC-8320 GPC (manufactured by TOSOH CORPORATION)

[0071] Guard column: Shodex GPC KD-G 4A (manufactured by Showa Denko K.K.)

[0072] First chromatographic column: Shodex GPC KD-806M 4A (manufactured by Showa Denko K.K.)

[0073] Second chromatographic column: Shodex GPC KD-803 4A (manufactured by Showa Denko K.K.)

[0074] Third chromatographic column: Shodex GPC KD-802.5 4A (manufactured by Showa Denko K.K.)

[0075] Detector: Differential refractometer

[0076] Column temperature: 40℃

[0077] Development solvent: dimethylformamide

[0078] Standard sample: polystyrene

[0079] Flow rate: 0.175 mL / min

[0080] Sample concentration: 0.2% by mass

[0081] Injection volume: 150μL

[0082] <Colloidal silica (B)>

[0083] The colloidal silica (B) of the present invention mainly has the effect of improving anti-fogging properties due to the hydrophilic groups on and inside the silica surface, and the function of reducing the water solubility of the anti-fogging coating by utilizing the interparticle cohesion between silica particles after film formation, thereby making it less prone to drip marks and improving water resistance.

[0084] The colloidal silica (B) is a component consisting of silica particles, represented by the chemical formula of SiO2, dispersed in a medium to form a colloidal state. Examples of solvents include methanol, ethanol, 2-propanol, 1-butanol, xylene, dimethylformamide, and water. Methanol, ethanol, 2-propanol, and water are preferred, and 2-propanol and water are more preferred. Furthermore, the surface of the silica particles in the colloidal silica (B) can be modified with a surface treatment agent such as a silane compound. At least one type of colloidal silica (B) can be used, or two or more can be used in combination.

[0085] The average particle size of the colloidal silica (B) is preferably 10–100 nm, more preferably 10–30 nm. The average particle size is the average primary particle size, expressed as the median diameter (D50) of the volumetric particle size distribution measured by dynamic light scattering. If the average particle size is less than 10 nm, there is a tendency for the adhesion between the obtained anti-fog coating and the substrate to decrease; if it is greater than 100 nm, there is a tendency for the transparency of the obtained anti-fog coating to decrease. Furthermore, the shape of the colloidal silica (B) can be granular, chain-like, or pearl necklace-like. Among these, the granular shape is preferred in terms of improving the transparency of the anti-fog coating.

[0086] As the commercially available product of the colloidal silica (B), for example, product names: "SNOWTEX-XS", "SNOWTEX-S", "SNOWTEX-30", "SNOWTEX-50-T", "SNOWTEX-30L", "SNOWTEX-YL", "SNOWTEX-ZL", "SNOWTEX MP-1040", "SNOWTEX-UP", "SNOWTEX-PS-S", "SNOWTEX-PS-M", "SNOWTEX-OXS", "SNOWTEX-OS", "SNOWTEX-O", "SNOWTEX-O-40", "SNOWTEX-OL", "SNOWTEX-OYL", "SNOWTEX-OUP", "SNOWTEX-PS-SO", "SNOWTEX-PS-MO", "SNOWTEX-NXS", "SNOWTEX-NS", "SNOWTEX-N", "SNOWTEX-N-40", "SNOWTEX-CXS", "SNOWTEX-C", "SNOWTEX-CM", "SNOWTEX-AK", "SNOWTEX-AK-L", "SNOWTEX-AK-Y", "Methanol silica sol", "MA-ST-M", "MA-ST-M", "MA-ST-L", "IPA-ST", "IPA-ST-L", "IPA-ST-ZL", "IPA-ST-UP", "EG-ST", "NPC-ST-30", "PGM-ST", "DMAC-ST" (all of which are manufactured by Nissan Chemical Corporation) can be listed. Among them, "SNOWTEX-O", "SNOWTEX-O-40", "SNOWTEX-OL", "SNOWTEX-OYL", "SNOWTEX-N", "SNOWTEX-N-40", "Methanol silica sol", "MA-ST-M", "MA-ST-L", "IPA-ST", "IPA-ST-L", "IPA-ST-ZL" in which the average particle diameter is 10 to 100 nm and the shape is granular and water or a monohydric alcohol having 1 to 4 carbon atoms is used as the dispersion medium are preferred, and "SNOWTEX-O", "SNOWTEX-O-40", "SNOWTEX-N", "SNOWTEX-N-40", "Methanol silica sol", "MA-ST-M", "IPA-ST" in which the average particle diameter is 10 to 30 nm and the shape is granular and water or a monohydric alcohol having 1 to 4 carbon atoms is used as the dispersion medium are more preferred.

[0087] <Solvent (C)>

[0088] The solvent (C) of the present invention contains water (C-1); a monohydric alcohol solvent having 1 to 4 carbon atoms (C-2); a solvent having at least one functional group selected from the group consisting of ketone, ester, two or more ether, thionone, and amide groups, and having a boiling point of 100°C or higher and 200°C or lower at one standard atmosphere (C-3); general formula (5): R 10 -OR 11 -OH represents alcohol ether solvents (C-4), in general formula (5), R 10 R is a straight-chain or branched alkyl group with 1 or more but less than 8 carbon atoms. 11 R is a straight-chain or branched alkylene group with 2 or more but less than 5 carbon atoms. 10 With R 11 The total number of carbon atoms is 3 or more and 12 or less.

[0089] <Solvent (C-1)>

[0090] The water (C-1) primarily improves the transparency of the anti-fog coating by increasing the solubility of the copolymer (A) in the anti-fog composition and inhibiting the whitening of the anti-fog coating caused by the aggregation of the copolymer (A).

[0091] <Solvent (C-2)>

[0092] The solvent (C-2) is a monohydric alcohol having a straight-chain or branched alkyl group having 1 to 4 carbon atoms. The solvent (C-2) primarily functions to: increase solvent volatility; and, during the application of the anti-fogging agent composition, suppress liquid sagging by increasing the solid content and viscosity of the coating substrate. At least one solvent (C-2) is sufficient, and two or more can be used in combination.

[0093] Examples of solvents (C-2) include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, and tert-butanol. From the perspective of improving the volatility of the solvent (C), suppressing liquid sagging during coating, improving the solubility of the copolymer (A) and the dispersibility of the colloidal silica (B), suppressing the agglomeration of the copolymer (A) and the whitening of the anti-fog coating caused by silica agglomeration, and improving the transparency of the anti-fog coating, a monohydric alcohol with 1 to 3 carbon atoms is preferred.

[0094] <Solvent (C-3)>

[0095] The solvent (C-3) is a solvent having at least one functional group selected from the group consisting of ketone, ester, two or more ether, thionyl, and amide groups, and having a boiling point of 100°C or higher and 200°C or lower at one standard atmosphere. The solvent (C-3) primarily functions to improve the adhesion of the antifogging agent composition after pre-drying when it is coated as a film. Only one type of solvent (C-3) is required, but two or more can be used in combination.

[0096] Examples of solvents (C-3) include diethyl ketone, ethyl propyl ketone, diacetone, diisoacetone, dibutyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, diacetone alcohol, isopropylidene acetone, n-butyl acetate, isobutyl acetate, methyl lactate, ethyl lactate, acetylacetone, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, 1,2-diethoxyethane, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, 1,4-dioxane, dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, etc.

[0097] From the perspective of suppressing cracks when coating with thick films and improving adhesion when coating with thin films, the boiling point of the solvent (C-3) at one standard atmosphere is preferably in the range of 130°C to 170°C.

[0098] <Solvent (C-4)>

[0099] The solvent (C-4) is of general formula (5): R 10 -OR 11 The alcohol ether solvent represented by -OH, in general formula (5), R 10 R is a straight-chain or branched alkyl group with 1 or more but less than 8 carbon atoms. 11 R is a straight-chain or branched alkylene group with 2 or more but less than 5 carbon atoms. 10 With R 11 The total number of carbon atoms is 3 or more and 12 or less. The solvent (C-4) mainly functions to mitigate the permeability of (C-3) to the substrate and to inhibit cracking when the antifogging composition is coated in a thick film. At least one solvent (C-4) may be used, or two or more may be used in combination.

[0100] As the solvent represented by the general formula (5) in the solvent (C-4), for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-1-propyl ether, ethylene glycol mono-isopropyl ether, ethylene glycol mono-1-butyl ether, ethylene glycol mono-isobutyl ether, ethylene glycol mono-tert-butyl ether, ethylene glycol mono-1-hexyl ether, ethylene glycol mono-2-ethylhexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol-1-mono-propyl ether, propylene glycol mono-isopropyl ether, propylene glycol mono-1-butyl ether, 3-methoxy-1-butanol, 3-methoxy-3-methyl-1-butanol, and the like can be exemplified.

[0101] From the viewpoint of moderating the permeation of the solvent (C-3) into the substrate upon thermal curing of the anti-fog agent composition, and inhibiting the generation of cracks upon thick film coating, the difference between the boiling points of the solvent (C-4) and (C-3) at one standard atmosphere is preferably within 20°C.

[0102] The content of the water (C-1) is preferably 50 to 550 parts by mass, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). From the viewpoint of improving the transparency of the anti-fog coating film, the content of the water (C-1) is more preferably 120 parts by mass or more, and further preferably 225 parts by mass or more, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). In addition, from the viewpoint of inhibiting the retention of air bubbles generated upon coating due to the increase in the viscosity of the anti-fog agent composition on the anti-fog coating film after curing, and improving the transparency of the anti-fog coating film, the content of the water (C-1) is more preferably 435 parts by mass or less, and further preferably 355 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). That is, from the viewpoint of improving the transparency of the anti-fog coating film, and inhibiting the retention of air bubbles generated upon coating due to the increase in the viscosity of the anti-fog agent composition on the anti-fog coating film after curing, and improving the transparency of the anti-fog coating film, the content of the water (C-1) is more preferably 120 parts by mass or more and 435 parts by mass or less, and further preferably 225 parts by mass or more and 355 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B).

[0103] The content of the solvent (C-2) is preferably 100 to 800 parts by mass relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). From the viewpoint of suppressing the occurrence of liquid sagging at the time of coating, the content of the solvent (C-2) is more preferably 200 parts by mass or more, and further preferably 270 parts by mass or more, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). In addition, from the viewpoint of improving the adhesion after pre-drying at the time of film coating, the content of the solvent (C-2) is more preferably 690 parts by mass or less, and further preferably 505 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). That is, from the viewpoints of suppressing the occurrence of liquid sagging at the time of coating and improving the adhesion after pre-drying at the time of film coating, the content of the solvent (C-2) is more preferably 200 parts by mass or more and 690 parts by mass or less, and further preferably 270 parts by mass or more and 505 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B).

[0104] The content of the solvent (C-3) is preferably 25 to 400 parts by mass relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). From the viewpoint of improving the adhesion at the time of film coating, the content of the solvent (C-3) is more preferably 65 parts by mass or more, and further preferably 90 parts by mass or more, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). In addition, from the viewpoint of suppressing the occurrence of cracks at the time of thick film coating, the content of the solvent (C-3) is more preferably 290 parts by mass or less, and further preferably 200 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). That is, from the viewpoints of improving the adhesion at the time of film coating and suppressing the occurrence of cracks at the time of thick film coating, the content of the solvent (C-3) is more preferably 65 parts by mass or more and 290 parts by mass or less, and further preferably 90 parts by mass or more and 200 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B).

[0105] The content of the solvent (C-4) is preferably 5 to 400 parts by mass relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). From the viewpoint of suppressing the occurrence of cracks at the time of thick film coating, the content of the solvent (C-4) is more preferably 25 parts by mass or more, and further preferably 70 parts by mass or more, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). In addition, from the viewpoint of improving the adhesion after pre-drying at the time of thin film coating, the content of the solvent (C-4) is more preferably 230 parts by mass or less, and further preferably 150 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). That is, from the viewpoints of suppressing the occurrence of cracks at the time of thick film coating and improving the adhesion after pre-drying at the time of thin film coating, the content of the solvent (C-4) is more preferably 25 parts by mass or more and 230 parts by mass or less, and further preferably 70 parts by mass or more and 150 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B).

[0106] The total content of the (C-1) to (C-4) components is 550 to 1350 parts by mass relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). From the viewpoints of suppressing the remaining of bubbles generated at the time of coating on the antifogging coating film and improving the transparency of the antifogging coating film, the total content of the (C-1) to (C-4) components is more preferably 810 parts by mass or more, and further preferably 900 parts by mass or more, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). In addition, from the viewpoint of suppressing the sagging of liquid at the time of coating, the total content of the (C-1) to (C-4) components is more preferably 1150 parts by mass or less, and further preferably 1015 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B). That is, from the viewpoints of suppressing the remaining of bubbles generated at the time of coating on the antifogging coating film, improving the transparency of the antifogging coating film, and suppressing the sagging of liquid at the time of coating, the total content of the (C-1) to (C-4) components is more preferably 810 parts by mass or more and 1150 parts by mass or less, and further preferably 900 parts by mass or more and 1015 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B).

[0107] The content of the water (C-1) is preferably 1000 parts by mass or more relative to 100 parts by mass of the copolymer (A), from the viewpoints of improving the solubility of the copolymer (A) and improving the transparency of the antifogging coating film.

[0108] The mass ratio of the solvent (C-3) to the solvent (C-4) ((C-3) / (C-4)) is 0.3 to 15. From the viewpoint of improving the adhesion after pre-drying when applied as a thin film and suppressing the generation of cracks when applied as a thick film, the mass ratio of the solvent (C-3) to (C-4) ((C-3) / (C-4)) is preferably in the range of 0.8 to 3.0, more preferably in the range of 1.0 to 2.0.

[0109] From the viewpoint of suppressing the generation of cracks when applied as a thick film and improving the adhesion of the anti-fog coating film, the content of the copolymer (A) in the total of the copolymer (A) and the colloidal silica (B) is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably 20% by mass or more. In addition, from the viewpoint of improving the anti-fog property and water resistance of the anti-fog coating film, the content of the copolymer (A) is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less.

[0110] From the viewpoint of being able to perform heat curing at a low temperature and in a short time, the anti-fog agent composition of the present application can add a curing catalyst.

[0111] As the curing catalyst, for example, alkyl sulfonic acid compounds such as sulfuric acid, fluorosulfonic acid, methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, aryl sulfonic acid compounds such as benzenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfonic acid, 4-ethylbenzenesulfonic acid, p-chlorobenzenesulfonic acid, m-xylene-4-sulfonic acid, 3-pyridine sulfonic acid, dinonyl naphthalene sulfonic acid, dinonyl naphthalene disulfonic acid, 1-pyrene sulfonic acid, and the like can be exemplified. From the viewpoint of excellent curing property and not easily remaining as a sag mark, the curing catalyst is preferably an aryl sulfonic acid compound having a benzyl structure or a naphthalene structure. The curing catalyst can be used alone or two or more kinds can be used at the same time.

[0112] In the case where the curing catalyst is used, from the viewpoint of promoting curing, sag marks, and improving water resistance, the mass ratio of the curing catalyst / the copolymer (A) is preferably 0.001 or more, and more preferably 0.003 or more. In addition, from the viewpoint of not deteriorating the properties of anti-fog property and sag marks, the mass ratio of the curing catalyst / the copolymer (A) is preferably 0.03 or less, and more preferably 0.01 or less. That is, in the case where the curing catalyst is used, from the viewpoint of promoting curing, sag marks, and improving water resistance, and not deteriorating the properties of anti-fog property and sag marks, the mass ratio of the curing catalyst / the copolymer (A) is more preferably 0.001 or more and 0.03 or less, and further preferably 0.003 or more and 0.01 or less.

[0113] From the viewpoint of being able to make the surface of the anti-fog coating film smoother, the anti-fog agent composition of the present application can add a leveling agent.

[0114] As the leveling agent, for example, polyether-modified polydimethylsiloxane, polyether-modified polydimethylpolysiloxane, polyether macromonomer-modified acrylate, acrylic polymer, silicone-acrylic polymer, and the like can be exemplified.

[0115] As commercially available products of the leveling agent, for example, product names "BYK-300", "BYK-320", "BYK-306", "BYK-307", "BYK-310", "BYK-313", "BYK-315N", "BYK-320", "BYK-322", "BYK-323", "BYK-325", "BYK-330", "BYK-331", "BYK-333", "BYK-342", "BYK-345 / 346", "BYK-347", "BYK-348", "BYK-349", "BYK-370", "BYK-377", "BYK-378", "BYK-3455", "BYK-3560", "BYK-3565", "BYK-3566" (manufactured by BYK), product names "KP-323", "KP-341", "KP-104", "KP-110", "KP-112", "KF-351A", "KF-352A", "KF-353", "KF-354L", "KF-355A", "KF-651A", "KF-945", "KF-640", "KF-642" (manufactured by Shin-Etsu Silicone Co., Ltd.), product names "DISPARLON 1970", "DISPARLON 230", "DISPARLON 1711EF", "DISPARLON 1761", "DISPARLON LS-001", "DISPARLON LS-050", "DISPARLON LS-460", "DISPARLON LS-480" (manufactured by Kusumoto Chemicals, Ltd.), product names "Poly-Flow WS", "Poly-Flow WS-314", "Poly-Flow KL-401", "Poly-Flow KL-402", "Poly-Flow KL-403", "Poly-Flow KL-404", "Poly-Flow KL-100", "Poly-Flow KL-850", "Poly-Flow KL-900", "LE-604", "LE-605", "LE-606" (manufactured by KYOEISYA CHEMICAL CO., LTD.), and the like can be exemplified. The leveling agent can be used alone or two or more kinds can be used simultaneously.

[0116] In the case where the leveling agent is used, the mass ratio of the leveling agent / the copolymer (A) is preferably 0.001 or more, more preferably 0.005 or more, from the viewpoint of improving the smoothness of the anti-fog coating film. In addition, the mass ratio of the leveling agent / the copolymer (A) is preferably 0.05 or less, more preferably 0.02 or less, from the viewpoint of not deteriorating the properties of the anti-fogging and sagging marks. That is, in the case where the leveling agent is used, the mass ratio of the leveling agent / the copolymer (A) is more preferably 0.001 or more and 0.05 or less, further preferably 0.005 or more and 0.02 or less, from the viewpoint of improving the smoothness of the anti-fog coating film, not deteriorating the properties of the anti-fogging and sagging marks.

[0117] In addition to the above-mentioned components, the anti-fog agent composition can be blended, as needed, with various additives such as a surfactant, an antioxidant, an ultraviolet absorber, a light stabilizer, and the like, which are commonly used as other components, within a range in which the properties of the sagging marks or the anti-fogging are not deteriorated. The other components can be blended in a conventional amount of addition of each additive, and are generally 5.0 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B).

[0118] <Anti-fogging product>

[0119] The anti-fogging product of the present application is formed by a coating method using a conventional coating material, in which the anti-fog agent composition is coated on a substrate (coated article) and is subjected to heat curing, thereby forming an anti-fog coating film on the surface of the substrate (coated article). In addition, a pre-drying step can be provided before the heat curing step, for the purpose of volatilizing and drying the solvent contained in the anti-fog coating film immediately after coating.

[0120] The kind of the substrate (coated article) is not particularly limited, and examples thereof include resin substrates such as polymethyl methacrylate resins, polycarbonate resins, polystyrene resins, acrylonitrile-styrene copolymer resins, polyvinyl chloride resins, acetate resins, ABS resins, polyester resins, and polyamide resins; and inorganic substrates such as glass. In addition, the shape of the substrate is not limited, and examples thereof include films or sheets, and molded products having a three-dimensional shape.

[0121] In the case where the substrate (coated article) is coated, it is preferable to remove foreign matter adhered to the surface of the substrate (coated article) before coating, for the purpose of improving the wettability of the anti-fog agent composition to the substrate (coated article), and preventing surface coating unevenness (hajiki). Examples of the removal of the foreign matter include dust removal using a high-pressure gas or an ionized gas, ultrasonic cleaning using a detergent aqueous solution or an alcoholic solvent, wiping using an alcoholic solvent or the like, and cleaning using ultraviolet rays or ozone. Examples of the coating method include dipping, flow coating, roll coating, bar coating, and spray coating.

[0122] The pre-drying is usually performed at a temperature of 20 to 50°C for 0.5 to 10 minutes.

[0123] When the substrate is a resin member, the heating is preferably performed at a temperature lower than the heat distortion temperature of the resin member. Since the heating time is affected by the heating temperature, it should be appropriately set. As one example, when the heating temperature is 80°C, the heating time is preferably 10 minutes or more, more preferably 15 minutes or more, and when the heating temperature is 130°C, the heating time is preferably 5 minutes or more, more preferably 10 minutes or more.

[0124] From the viewpoint of improving the adhesion after the pre-drying when applied as a thin film, the film thickness of the antifog coating film is preferably 0.5 μm or more, more preferably 1 μm or more. Further, from the viewpoint of suppressing the generation of cracks when applied as a thick film and suppressing the sagging of the liquid during the application, it is preferably 20 μm or less, more preferably 10 μm or less, and further preferably 7 μm or less.

[0125] The antifog product can be more favorably used for products used in environments where condensation is likely to occur, and the use thereof is not particularly limited. As the antifog product, for example, the following can be listed: vehicle lamps (headlamps, auxiliary headlamps, clearance lamps, license plate lamps, tail lamps, parking lamps, back-up lamps, turn signal lamps, auxiliary turn signal lamps, hazard warning lamps, etc.), eyeglasses, windows, mirrors, etc.

[0126] Example

[0127] Hereinafter, the application will be further explained by citing examples, but the application is not limited only by these examples.

[0128] Preparation of Copolymer (A)

[0129] Synthesis Example 1

[0130] Into a reaction vessel equipped with a stirring device, a nitrogen gas inlet tube, and a condenser tube, 120 parts by mass of 1-propanol as a solvent (C-2), 60 parts by mass of dimethyl acrylamide (DMAA) as a monomer (a-1), 20 parts by mass of N-methylol acrylamide (N-MAA) as (a-2), and 20 parts by mass of 2-hydroxyethyl acrylate (HEA) as (a-3) were added, and heated to 75°C while blowing nitrogen gas. To this, a liquid in which 0.6 parts by mass of t-hexyl peroxyneodecanoate as a radical polymerization initiator was dissolved in 30 parts by mass of 1-propanol (product name: Perhexyl ND, manufactured by NOF Corporation) was added dropwise over 3 hours. Further polymerization was performed for 2 hours, and a solution of the copolymer (A-1) of Example 1 having a copolymer concentration of 40 mass% and a number average molecular weight (Mn) of 94,000 was obtained.

[0131] <SYNTHESIS EXAMPLES -2 TO 6>

[0132] In each of the synthesis examples, the copolymer (A) of Synthesis Examples 2 to 6 was prepared in the same manner as in Synthesis Example 1 except that the raw material of Synthesis Example 1 was changed to the raw material and the ratio thereof described in Table 1.

[0133] [Table 1]

[0134]

[0135] The abbreviations in Table 1 are described below.

[0136] DMAA (N,N-dimethylacrylamide)

[0137] DEAA (N,N-diethylacrylamide)

[0138] N-MAA (N-hydroxymethylacrylamide)

[0139] HEA (2-hydroxyethyl acrylate)

[0140] HEMA (2-hydroxyethyl methacrylate)

[0141] <Example 1>

[0142] <Preparation of an Antifogging Agent Composition>

[0143] To 62.5 parts by mass (25 parts by mass in terms of solid content) of the above-obtained copolymer (A-1) solution was added 362.5 parts by mass of 1-propanol as the solvent (C-2), 150 parts by mass of diacetone alcohol as the solvent (C-3), 100 parts by mass of 3-methoxy-l-butanol as the solvent (C-4), and mixed 375 parts by mass (75 parts by mass in terms of solid content) of SNOWTEX O (manufactured by Nissan Chemical Corporation, acidic sol type, average particle diameter: 12 nm, solid content: 20%) as the colloidal silica (B), 0.1 part by mass of dinonylnaphthalene disulfonic acid as the curing catalyst, and 0.3 part by mass of a polyether-modified polydimethylsiloxane (product name: BYK333, manufactured by BYK Japan KK.) as the leveling agent, to prepare an antifogging agent composition having a solid content of 9.6%.

[0144] <Manufacture of an Antifogging Product>

[0145] The antifog agent composition obtained above was applied to a polycarbonate (PC) plate having a thickness of 3 mm by spray coating in such a manner that the film thickness of the cured antifog coating film would be about 1 to 5 μm, and was heat cured at 120°C for 20 minutes in an atmosphere of 25°C, 30% RH to produce an antifog product (test piece) having an antifog coating film.

[0146] Using the antifog agent composition and test piece obtained above, the following evaluations were performed. The evaluation results are shown in Table 2.

[0147] (1) Antifog property

[0148] (1-1) Steam test

[0149] The test piece was set at a position 5 cm above the water surface of a warm water bath maintained at 80°C with the antifog coating film surface facing downward, and steam from the warm water bath was continuously applied to a predetermined 5 cm x 5 cm area of the antifog coating film. The presence or absence of fog after 10 seconds of steam application was evaluated by visual observation according to the following four grades. In addition, as long as the evaluation was Δ or more, there was no problem in practical use, and it was preferable to be O, and more preferable to be.

[0150] : Water film was formed immediately after steam application, and no fog was observed.

[0151] : A momentary fog was observed immediately after steam application, but a water film was formed immediately thereafter, and no fog was observed.

[0152] : Fog was observed immediately after steam application, but a water film was formed, and no fog was observed.

[0153] : Fog was observed immediately after steam application, and no water film was formed.

[0154] (1-2) Repeated steam test (sustained test)

[0155] The test piece was set at a position 5 cm above the water surface of a warm water bath maintained at 80°C with the antifog coating film surface facing downward, and steam from the warm water bath was continuously applied to a predetermined 5 cm x 5 cm area of the antifog coating film for 10 seconds. After that, the test piece was dried at room temperature for 1 hour in a vertical standing state. After the above operation was repeated 50 times, the presence or absence of fog after 10 seconds of steam application was evaluated by visual observation according to the following four grades. In addition, as long as the evaluation was Δ or more, there was no problem in practical use, and it was preferable to be O, and more preferable to be.

[0156] : Water film was formed immediately after steam application, and no fog was observed.

[0157] : A momentary fog was observed immediately after steam application, but a water film was formed immediately thereafter, and no fog was observed.

[0158] Δ: Fog was observed immediately after steam application, but a water film was formed and no fogging occurred.

[0159] X: Fog was observed immediately after steam application and no water film was formed.

[0160] <(2) Transparency>

[0161] The haze of the test piece obtained in the production of the anti-fog product was measured using a haze meter NDH5000 manufactured by NIPPON DENSHOKU INDUSTRIES Co., Ltd. In addition, the blank was measured in air (without a substrate) and evaluated in accordance with the haze value in four grades as described below. In this test, as long as the evaluation is A or more, there is no problem in practical use. It is preferable that it be O, and more preferable that it be O. Furthermore, the haze value of a polycarbonate (PC) plate having a thickness of 3 mm was 0.30.

[0162] O: The haze value was 0.3 to 0.4.

[0163] O: The haze value was 0.4 to 0.6.

[0164] Δ: The haze value was 0.6 to 0.8.

[0165] X: The haze value was 0.8 or more.

[0166] <(3) Adhesion>

[0167] <(3-1) Initial Adhesion>

[0168] A notch was cut in a region of 1 cm in length and 1 cm in width on the anti-fog coating film surface at intervals of 1 mm in length and 1 mm in width using a cutting knife to form 100 checkers. A transparent tape was strongly pressed against the checkers and one end of the tape was peeled off at an angle of 45° at once. The state of the checkers was evaluated by the naked eye in three grades as described below. In addition, as long as the evaluation is O or more, there is no problem in practical use, and it is more preferable that it be O.

[0169] O: The haze value was 0.3 to 0.4.

[0170] O: The haze value was 0.4 to 0.6.

[0171] X: The haze value was 0.8 or more.

[0172] <(3-2) Adhesion after pre-drying when coating with a film>

[0173] The antifogging agent composition obtained above was applied to a polycarbonate (PC) plate by a spray method so that the film thickness of the cured antifogging coating film would be 1 μm, and after 3 minutes and 5 minutes of pre-drying in an environment of 25°C, 50% RH, heating and curing were performed at 120°C for 20 minutes. For the obtained antifogging coating film, a cutting knife was used to cut a notch in a region of 1 cm in length and 1 cm in width on the surface of the antifogging coating film at intervals of 1 mm in length and 1 mm in width to make 100 checkerboards. A transparent adhesive tape was strongly pressed against the checkerboard portion, and one end of the tape was peeled off at an angle of 45° at one time. The state of the checkerboard was evaluated by the naked eye according to the following three grades. In addition, as long as the evaluation was ○ or more, there was no problem in practical use, and it was more preferable that the evaluation be ◎.

[0174] ◎: No peeling was observed at all.

[0175] O: Partial peeling was observed.

[0176] X: Peeling was observed in all.

[0177] < (4) SAGGING MARKS >

[0178] A test piece was set at a position 5 cm above the water surface of a warm water bath maintained at 80°C with the antifogging coating film surface facing downward, and after steam from the warm water bath was continuously applied for 10 seconds to a predetermined 5 cm x 5 cm region of the antifogging coating film, the test piece was made to sag by being set vertically, and the test piece was set horizontally and left to dry at room temperature. After drying, the presence or absence of sagging marks was evaluated by the naked eye according to the following four grades. In addition, as long as the evaluation was Δ or more, there was no problem in practical use, and it was preferable that the evaluation be O, and more preferable that the evaluation be.

[0179] ◎: No sagging marks were observed at all.

[0180] O: Almost no sagging marks were observed.

[0181] Δ: Sagging marks were not obvious.

[0182] X: Sagging marks were obvious.

[0183] < (5) CRACKS WHEN THICK FILM IS APPLIED >

[0184] The antifogging agent composition obtained above was applied to a polycarbonate (PC) plate by a spray method, and heating and curing were performed at 120°C for 20 minutes. The thinnest film thickness at which cracks were generated in the obtained antifogging coating film was measured using a film thickness meter F20-EXR manufactured by Filmetrics, Inc., and evaluation was performed according to the following four grades. In addition, as long as the evaluation was Δ or more, there was no problem in practical use, and it was preferable that the evaluation be O, and more preferable that the evaluation be.

[0185] ◎: The film thickness at which cracks were generated was 6 μm or more.

[0186] O: film thickness at which cracking occurs is 5 to 6 μm.

[0187] Δ: film thickness at which cracking occurs is 4 to 5 μm.

[0188] X: film thickness at which cracking occurs is less than 4 μm.

[0189] <(6) Water resistance>

[0190] After immersing the test piece in 40°C warm water for 240 hours, the appearance of the anti-fog coating film after standing at room temperature for 1 hour was evaluated by the naked eye according to the following 4 grades. In addition, as long as the evaluation is O or more, there is no problem in practical use, and more preferably, it is.

[0191] ◎: appearance is not changed compared to before the test.

[0192] O: the surface of the anti-fog coating film is slightly rough.

[0193] X: the anti-fog coating film is peeled off.

[0194] <(7) Coatability (liquid sagging)

[0195] When the anti-fog agent composition obtained above was coated on a coated substrate polycarbonate (PC) plate by a spray coating method, and the coated polycarbonate (PC) plate was vertically erected and allowed to dry, the thickest film thickness at which no liquid sagging of the coating liquid occurred was measured using a film thickness meter F20-EXR manufactured by Filmetrics, Inc., and evaluated according to the following 4 grades. In addition, as long as the evaluation is Δ or more, there is no problem in practical use, and preferably, it is O, and more preferably, it is.

[0196] ◎: film thickness at which liquid sagging occurs is 6 μm or more.

[0197] O: film thickness at which liquid sagging occurs is 5 to 6 μm.

[0198] Δ: film thickness at which liquid sagging occurs is 4 to 5 μm.

[0199] X: film thickness at which liquid sagging occurs is less than 4 μm.

[0200] <Examples 2 to 33, Comparative Examples 1 to 10>

[0201] <Preparation of anti-fog agent composition and production of anti-fog property product>

[0202] In each of the examples and comparative examples, the antifogging agent composition of Examples 2 to 33 and Comparative Examples 1 to 10 was prepared in the same manner as in Example 1, except that the raw materials of Example 1 were changed to the raw materials and their proportions described in Tables 2 to 5. Further, the antifogging property product (test piece) having the antifogging coating film of Examples 2 to 33 and Comparative Examples 1 to 10 was produced in the same manner as in Example 1.

[0203] The same evaluation as in Example 1 was carried out using the antifogging agent composition and test piece obtained above. The results are shown in Tables 2 to 5.

[0204] [Table 2]

[0205]

[0206] [Table 3]

[0207]

[0208] [Table 4]

[0209]

[0210] [Table 5]

[0211]

[0212] The abbreviations in Tables 2 to 5 are described below.

[0213] ST-O (product name: "SNOWTEX O", average particle diameter: 12 nm, water-dispersed silica sol, manufactured by Nissan Chemical Corporation, effective ingredient: 20 mass%)

[0214] IPA-ST (product name: "IPA-ST", average particle diameter: 12 nm, 2-propanol-dispersed silica sol, manufactured by Nissan Chemical Corporation, effective ingredient: 30 mass%)

[0215] DNNDSA (dinonyl naphthalene disulfonic acid)

[0216] RAPISOLA-80 (product name: "RAPISOLA-80", sulfosuccinic acid diester salt, manufactured by NOF Corporation)

[0217] BYK-333 (product name: "BYK333", polyether-modified polydimethylsiloxane, manufactured by BYK Company)

Claims

1. An antifogging agent composition, which is an antifogging agent composition containing a copolymer (A), colloidal silica (B), and a solvent (C), characterized in that, the copolymer (A) is a (meth)acrylate copolymer obtained from a monomer mixture containing a monomer (a-1) represented by General Formula (1), a monomer (a-2) represented by General Formula (2), and one or more monomers (a-3) selected from the group consisting of a monomer having a hydroxyl group represented by General Formula (3) and a monomer having a hydroxyl group represented by General Formula (4), [Chemical Formula 1] In General Formula (1), R 1 is a hydrogen atom or a methyl group, R 2 and R 3 are independently a hydrogen atom or a straight chain or branched alkyl group having a carbon chain of 1 to 4, [Chemical Formula 2] In General Formula (2), R 4 is a hydrogen atom or a methyl group, and R 5 is a hydrogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms. [Chemical Formula 3] In General Formula (3), R 6 is a hydrogen atom or a methyl group, R 7 is a linear or branched alkylene group having 1 to 8 carbon atoms, [Chemical Formula 4] In General Formula (4), R 8 is a hydrogen atom or a methyl group, R 9 is a linear or branched alkylene group having 2 to 8 carbon atoms, the solvent (C) contains: water (C-1), a monohydric alcohol solvent (C-2) having 1 to 4 carbon atoms, a solvent (C-3) having at least one functional group selected from the group consisting of a ketone group, an ester group, two or more ether groups, a thione group, and an amide group in the molecule, and having a boiling point of 100°C or higher and 200°C or lower at one standard atmosphere, and General Formula (5): R 10 -O-R 11 -OH, alcohol ether solvents (C-4), In General Formula (5), R 10 is a linear or branched alkyl group having 1 or more and 8 or less carbon atoms, R 11 is a linear or branched alkylene group having 2 or more and 5 or less carbon atoms, R 10 is a linear or branched alkyl group having 1 or more and 8 or less carbon atoms, and the total number of carbon atoms of R 11 is 3 or more and 12 or less. the total of the water (C-1), the solvent (C-2), the solvent (C-3), and the solvent (C-4) is 550 to 1350 parts by mass with respect to 100 parts by mass of the total of the copolymer (A) and the colloidal silica (B), the mass ratio ((C-3) / (C-4)) of the solvent (C-3) and the solvent (C-4) is 0.3 to 15.

2. The anti-fog agent composition according to claim 1, characterized by in the monomer mixture, the proportion of the monomer (a-1) is 30 to 80 mass%, the proportion of the monomer (a-2) is 5 to 35 mass%, and the proportion of the monomer (a-3) is 5 to 35 mass%.

3. The anti-fog agent composition according to claim 1 or 2, characterized by, in the total of the copolymer (A) and the colloidal silica (B), the proportion of the copolymer (A) is 10 to 50 mass%.

4. An anti-fog product characterized in that, an antifogging film formed of the antifogging agent composition described in Claim 1 or 2 on a substrate.

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