WO2025182814A1 - Anti-fogging agent composition and anti-fogging article having anti-fogging film formed from said composition - Google Patents

Abstract

This anti-fogging agent composition contains a copolymer (A), a polyfunctional block isocyanate compound (B), a surfactant (C), and a solvent (D), wherein the solvent (D) contains a dihydric alcohol (D-1) and a glycol ether (D-2) with the content of (D-1) being 5-35 parts by mass and the content of (D-2) being 3-15 parts by mass with respect to 100 parts by mass of the anti-fogging agent composition, and the mass ratio [(D-1)/(D-2) ] of (D-1) to (D-2) being 0.5-8.0. This anti-fogging agent composition provides an anti-fogging film formed by heat curing that excels in appearance, adhesion, anti-fogging performance, and water streaking marks, and can suppress dripping or brush marks during coating, and can suppress solvent cracking when performing heat curing at a high temperature.

Description

Antifogging agent composition and antifogging article having antifogging film formed from said composition

The present invention relates to an anti-fogging agent composition and an anti-fogging article having an anti-fogging film formed from the composition.

In vehicle lighting fixtures such as automobile headlamps, high-humidity air can enter the lamp chamber, causing the lens to cool due to external air or rainfall, resulting in condensation of water on the inner surface, causing fogging. This reduces the brightness of the vehicle light and impairs the aesthetic appearance of the lens surface, causing discomfort to users. A known method of preventing this type of lens fogging is to apply an anti-fogging agent to the area where fogging occurs (the inside of the lens) to form an anti-fogging film (a dried or hardened coating).

Patent Document 1 discloses an anti-fogging agent composition containing a specific hydrophilic resin, a surfactant, and a solvent.

The anti-fogging agent composition disclosed in Patent Document 1 is capable of suppressing solvent cracking and providing a good cured coating film appearance during coating and drying, and also has good paintability, resulting in a smooth coating film surface upon application.

JP 2016-027134 A

In recent years, automobile headlamps have increasingly adopted lens substrates with relatively high internal residual stress due to their increasing size and complexity. When an anti-fog composition is applied to such lens substrates and then heat-cured, solvent cracks are more likely to occur on the lens surface. Since there are limits to what can be achieved through production process innovations such as painting and heat-curing, there is a growing need for anti-fog composition solutions that can suppress solvent cracks.

The inventors have discovered that while glycol ether solvents, which are commonly used in conventional anti-fog compositions, impart good coating properties and coating appearance to anti-fog compositions, they also corrode the base resin at high temperatures during heat curing. Some production lines are designed to rapidly increase the lens temperature in order to improve productivity by shortening the heat curing time, and it has been discovered that in such cases solvent cracking occurs, raising concerns that the aesthetic appearance of the lens surface may be impaired.

The anti-fog composition disclosed in Patent Document 1 mentioned above can suppress solvent cracking at room temperature during application, but if the lens is rapidly heated and dried during heat curing, solvent cracking occurs, which can cause concerns about impairing the aesthetic appearance of the lens surface.

In light of the above, the present invention aims to provide an anti-fog agent composition that forms an anti-fog film by heat curing that has good appearance, adhesion, anti-fog properties, and water drip marks, and that can suppress dripping and blushing during application and solvent cracking when heat curing is performed at high temperatures, as well as an anti-fog article having an anti-fog film formed from said composition. Note that when application and heat curing are performed in a high-humidity environment (e.g., relative humidity of 80% or higher), the heat of vaporization caused by the solvent volatilizing on the coating surface causes a rapid drop in the coating surface temperature, causing moisture in the air to condense on the coating surface, resulting in aggregation and precipitation of resin components and the development of unevenness on the coating surface, causing the coating to appear white. This phenomenon is called blushing.

That is, the present invention provides an antifogging agent composition containing a copolymer (A), a polyfunctional blocked isocyanate compound (B), a surfactant (C), and a solvent (D), wherein the copolymer (A) is a (meth)acrylate copolymer obtained from a monomer mixture containing a monomer (A-1) represented by the following general formula (1):
(In general formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is a linear or branched alkyl group having 1 to 4 carbon atoms, -C(CH ₃ ) ₂ CH ₂ COCH ₃ , -C ₂ H ₄ N(CH ₃ ) ₂ , or -C ₃ H ₆ N(CH ₃ ) ₂ , and R ³ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.)
the solvent (D) contains a dihydric alcohol (D-1) and a glycol ether (D-2),
The dihydric alcohol (D-1) is a compound represented by the following general formula (7):
HO-R ¹⁵ -OH...(7)
(In general formula (7), R ¹⁵ is a linear, branched, or cyclic alkylene group having 1 to 10 carbon atoms.)
The glycol ether (D-2) is a compound represented by the following general formula (8):
R ¹⁶ -O-R ¹⁷ -OH...(8)
(In general formula (8), R ¹⁶ is a linear, branched, or cyclic alkyl group having 1 to 8 carbon atoms, and R ¹⁷ is a linear or branched alkylene group having 1 to 4 carbon atoms.)
the dihydric alcohol (D-1) is contained in an amount of 5 parts by mass or more and 35 parts by mass or less, and the glycol ether (D-2) is contained in an amount of 3 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the antifogging agent composition;
The antifogging agent composition according to the present invention relates to an antifogging agent composition in which the mass ratio of the dihydric alcohol (D-1) to the glycol ether (D-2) [(D-1)/(D-2)] is 0.5 or more and 8.0 or less.

The present invention also relates to an anti-fogging article having an anti-fogging film formed from the anti-fogging agent composition on a substrate.

The present invention provides an anti-fogging agent composition that forms an anti-fogging film by heat curing that has good appearance, adhesion, anti-fogging properties, and water drip marks, and that can suppress dripping and blushing during application and solvent cracking when heat curing is performed at high temperatures, as well as an anti-fogging article having an anti-fogging film formed from the composition.

The anti-fogging agent composition of the present invention contains a copolymer (A), a polyfunctional blocked isocyanate compound (B), a surfactant (C), and a solvent (D).

<Copolymer (A)>
The copolymer (A) of the present invention is a (meth)acrylate copolymer obtained from a monomer mixture containing the following monomer (A-1):

<Monomer (A-1)>
The monomer (A-1) is a monomer represented by the following general formula (1):
(In general formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is a linear or branched alkyl group having 1 to 4 carbon atoms, -C(CH ₃ ) ₂ CH ₂ COCH ₃ , -C ₂ H ₄ N(CH ₃ ) ₂ , or -C ₃ H ₆ N(CH ₃ ) ₂ , and R ³ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.)

In the general formula (1), examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a t-butyl group, etc. In the general formula (1), from the viewpoint of improving the anti-fogging performance of the anti-fogging film and the adhesion to the substrate, R ¹ is preferably a hydrogen atom, R ² is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group, and R ³ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.

Preferably, N,N-dimethyl(meth)acrylamide or N,N-diethyl(meth)acrylamide can be used as the monomer (A-1).

At least one type of the monomer (A-1) may be used, and two or more types may be used in combination.

The monomer mixture preferably contains, as other monomers in addition to the monomer (A-1), one or more monomers (A-3) selected from the group consisting of a monomer (A-2) represented by the following general formula (2), a monomer represented by the following general formula (3), and a monomer represented by the following general formula (4), and one or more monomers (A-4) selected from the group consisting of a monomer represented by the following general formula (5), and a monomer represented by the following general formula (6):
(In general formula (2), ^R4 is a hydrogen atom or a methyl group, and ^R5 is a linear, branched, or cyclic hydrocarbon group having 1 to 18 carbon atoms.)
(In general formula (3), ^R6 is a hydrogen atom or a methyl group, ^R7 is a linear alkylene group having 1 to 4 carbon atoms, and ^R8 is a substituent having a heterocyclic skeleton.)
(In general formula (4), ^R9 is a hydrogen atom or a methyl group, and ^R10 is a substituent having a heterocyclic skeleton.)
(In general formula (5), R ¹¹ is a hydrogen atom or a methyl group, R ¹² is a linear or branched alkylene group having 2 to 4 carbon atoms, or —C ₂ H ₄ (OCO(CH ₂ ) ₅ ) _n —, where n is 1 to 5.)
(In general formula (6), R ¹³ is a hydrogen atom or a methyl group, and R ¹⁴ is a linear or branched alkylene group having 1 to 4 carbon atoms.)

<Monomer (A-2)>
The monomer (A-2) is a monomer represented by the following general formula (2):
(In general formula (2), ^R4 is a hydrogen atom or a methyl group, and ^R5 is a linear, branched, or cyclic hydrocarbon group having 1 to 18 carbon atoms.)

In the general formula (2), examples of the linear, branched, or cyclic hydrocarbon group having 1 to 18 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-amyl, i-amyl, t-amyl, n-hexyl, cyclohexyl, n-octyl, 2-ethylhexyl, n-nonyl, isobornyl, lauryl, myristyl, cetyl, and stearyl; alkenyl groups such as oleyl; and aryl groups such as phenyl. From the viewpoints of improving the adhesion and water resistance between the anti-fog film and the substrate and improving the anti-fog performance of the anti-fog film, the branched or cyclic hydrocarbon group having 3 to 16 carbon atoms is preferred, and the branched or cyclic hydrocarbon group having 4 to 12 carbon atoms is more preferred.

At least one type of the monomer (A-2) may be used, and two or more types may be used in combination.

<Monomer (A-3)>
The monomer (A-3) is at least one selected from the group consisting of a monomer represented by the following general formula (3) and a monomer represented by the following general formula (4).
(In general formula (3), ^R6 is a hydrogen atom or a methyl group, ^R7 is a linear alkylene group having 1 to 4 carbon atoms, and ^R8 is a substituent having a heterocyclic skeleton.)
(In general formula (4), ^R9 is a hydrogen atom or a methyl group, and ^R10 is a substituent having a heterocyclic skeleton.)

In the general formula (3), examples of the linear alkylene group having 1 to 4 carbon atoms include a methylene group, an ethylene group, a propylene group, and a butylene group, and examples of the substituent having a heterocyclic skeleton include an epoxy group, a 3,4-epoxycyclohexyl group, an oxetanyl group, a furyl group, a tetrahydrofuryl group, an oxotetrahydrofuryl group, a 2-oxo-1,3-dioxolanyl group, a mevalonate lactone group, and a cyclic trimethylol group. Examples include oxygen-containing heterocyclic substituents such as a propaneformal group; oxygen- and nitrogen-containing heterocyclic substituents such as a morpholino group; and nitrogen-containing heterocyclic substituents such as an N-succinimidyl group, a 1,2,2,6,6-pentamethyl-4-piperidyl group, a 2,2,6,6-tetramethyl-4-piperidyl group, and a 2,2,6,6-tetramethylpiperidine-1-oxyl group. The heterocyclic ring is preferably a 3-, 4-, 5-, or 6-membered ring. From the perspective of suppressing watermark whitening, the substituent having a heterocyclic skeleton is preferably an oxygen-containing heterocyclic substituent.

In general formula (4), examples of the substituent having a heterocyclic skeleton include oxygen-containing heterocyclic substituents such as epoxy groups, 3,4-epoxycyclohexyl groups, oxetanyl groups, furyl groups, tetrahydrofuryl groups, oxotetrahydrofuryl groups, 2-oxo-1,3-dioxolanyl groups, mevalonate lactone groups, and cyclic trimethylolpropane formal groups; oxygen- and nitrogen-containing heterocyclic substituents such as morpholino groups; and nitrogen-containing heterocyclic substituents such as N-succinimidyl groups, 1,2,2,6,6-pentamethyl-4-piperidyl groups, 2,2,6,6-tetramethyl-4-piperidyl groups, and 2,2,6,6-tetramethylpiperidine-1-oxyl groups. The heterocyclic ring is preferably a three-, four-, five-, or six-membered ring. From the perspective of suppressing watermark whitening, the substituent having a heterocyclic skeleton is preferably an oxygen-containing heterocyclic substituent.

Preferably, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, oxotetrahydrofurfuryl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, morpholinoethyl (meth)acrylate, tetramethylpiperidyl (meth)acrylate, and pentamethylpiperidyl (meth)acrylate can be used as the monomer (A-3). Glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, oxotetrahydrofurfuryl (meth)acrylate, and cyclic trimethylolpropane formal (meth)acrylate can be more preferably used.

At least one type of the monomer (A-3) may be used, and two or more types may be used in combination.

<Monomer (A-4)>
The monomer (A-4) is at least one selected from the group consisting of a monomer represented by the following general formula (5) and a monomer represented by the following general formula (6).
(In general formula (5), R ¹¹ is a hydrogen atom or a methyl group, R ¹² is a linear or branched alkylene group having 2 to 4 carbon atoms, or —C ₂ H ₄ (OCO(CH ₂ ) ₅ ) _n —, where n is 1 to 5.)
(In general formula (6), R ¹³ is a hydrogen atom or a methyl group, and R ¹⁴ is a linear or branched alkylene group having 1 to 4 carbon atoms.)

In the general formula (5), examples of the linear or branched alkylene group having 2 to 4 carbon atoms include an ethylene group, a propylene group, a 2-methylmethylene group, a butylene group, a 2-methylpropylene group, a 3-methylpropylene group, a 2,2-dimethylmethylene group, a 2-ethylmethylene group, etc. From the viewpoint of improving the water resistance and anti-fogging durability of the anti-fogging film, R ¹² is preferably a linear alkylene group having 2 to 4 carbon atoms, more preferably an ethylene group, a propylene group, or a 2-methylmethylene group, and even more preferably an ethylene group or a propylene group.

In the general formula (6), examples of the linear or branched alkylene group having 1 to 4 carbon atoms include a methylene group, an ethylene group, a propylene group, a 2-methylmethylene group, a butylene group, a 2-methylpropylene group, a 3-methylpropylene group, a 2,2-dimethylmethylene group, a 2-ethylmethylene group, etc. From the viewpoint of improving the water resistance and anti-fogging durability of the anti-fogging film, R ¹⁴ is preferably a linear alkylene group having 2 to 4 carbon atoms, more preferably a methylene group, an ethylene group, or a propylene group, and even more preferably a methylene group or an ethylene group.

Preferably, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, or 2-hydroxyethyl (meth)acrylamide can be used as the monomer (A-4). More preferably, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, or 2-hydroxyethyl (meth)acrylamide can be used.

At least one type of the monomer (A-4) may be used, and two or more types may be used in combination.

The hydroxyl value of the copolymer (A) can be calculated from the hydroxyl value (theoretical value) of the monomer (A-4) using the following formula:
[Hydroxyl value of monomer (A-4) (mg KOH/g)]=56,100/[molecular weight of monomer (A-4) (g/mol)]
[Hydroxyl value of copolymer (A)] = [Hydroxyl value of monomer (A-4) (mg KOH/g)] × [mass (g) of monomer (A-4)] / [mass (g) of copolymer (A)]
Furthermore, from the viewpoint of improving water resistance and reducing traces of dripping water, the viscosity is preferably 5 mgKOH/g or more, more preferably 20 mgKOH/g or more, and even more preferably 40 mgKOH/g or more, and from the viewpoint of improving adhesion, the viscosity is preferably 160 mgKOH/g or less, more preferably 120 mgKOH/g or less, and even more preferably 90 mgKOH/g or less.

The proportions of each monomer component in the monomer mixture that forms the copolymer (A) of the present invention are described below.

The amount of the monomer (A-1) is preferably 10 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the monomer mixture. From the viewpoint of improving anti-fogging performance, the amount of the monomer (A-1) is preferably 15 parts by mass or more, and more preferably 20 parts by mass or more per 100 parts by mass of the monomer mixture. From the viewpoint of improving adhesion and water resistance and reducing water drip marks, the amount of the monomer (A-1) is preferably 45 parts by mass or less, and more preferably 40 parts by mass or less.

When the monomer (A-2) is used, the amount of the monomer (A-2) is preferably 3 parts by mass or more and 30 parts by mass or less per 100 parts by mass of the monomer mixture. From the viewpoints of improving water resistance and adhesion and suppressing whitening due to dripping water, the amount of the monomer (A-2) is preferably 5 parts by mass or more, and more preferably 8 parts by mass or more per 100 parts by mass of the monomer mixture, and from the viewpoint of improving anti-fogging performance, the amount of the monomer (A-2) is preferably 25 parts by mass or less, and more preferably 20 parts by mass or less.

When the monomer (A-3) is used, the amount of the monomer (A-3) is preferably 20 parts by mass or more and 70 parts by mass or less per 100 parts by mass of the monomer mixture. From the viewpoints of improving adhesion and suppressing whitening due to dripping water, the amount of the monomer (A-3) is preferably 30 parts by mass or more, and more preferably 35 parts by mass or more per 100 parts by mass of the monomer mixture. From the viewpoints of improving anti-fogging properties and reducing the whitening due to dripping water, the amount of the monomer (A-3) is preferably 60 parts by mass or less, and more preferably 55 parts by mass or less per 100 parts by mass of the monomer mixture.

When the monomer (A-4) is used, the amount of the monomer (A-4) is preferably 5 parts by mass or more and 30 parts by mass or less per 100 parts by mass of the monomer mixture. From the viewpoint of improving water resistance and reducing water drip marks, the amount of the monomer (A-3) is preferably 8 parts by mass or more, more preferably 10 parts by mass or more, per 100 parts by mass of the monomer mixture. From the viewpoint of improving adhesion, the amount of the monomer (A-3) is preferably 25 parts by mass or less, more preferably 20 parts by mass or less.

When the monomers (A-2) to (A-4) are used, the total proportion of the monomers (A-1) to (A-4) in the monomer mixture is preferably 85% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

The monomer mixture may contain other monomers in addition to the monomers (A-1) to (A-4), such as aromatic vinyl monomers such as styrene, vinyl toluene, and α-methyl styrene; vinyl monomers containing a quaternary ammonium salt structure such as (meth)acryloyloxyethyl trimethyl ammonium chloride and (meth)acryloylaminopropyl trimethyl ammonium chloride; aromatic acrylic monomers such as phenoxyethyl (meth)acrylate; carboxyl group-containing monomers such as (meth)acrylic acid, itaconic acid, crotonic acid, and maleic acid, as well as their ammonium salts, organic amine salts, and alkali metal salts; sulfonic acid group-containing vinyl monomers such as styrene sulfonic acid, vinyl sulfonic acid, methallyl sulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, and 3-sulfopropyl (meth)acrylate, as well as their ammonium salts, organic amine salts, and alkali metal salts; Examples of suitable vinyl monomers include phosphate group-containing vinyl monomers such as 2-(meth)acryloyloxyethyl acid phosphate, and their ammonium salts, organic amine salts, and alkali metal salts; bifunctional (meth)acrylates such as 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol (meth)acrylate, 1,10-decanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, glycerin di(meth)acrylate, and N,N'-methylenebis[(meth)acrylamide]; multifunctional vinyl monomers such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate; and vinyl monomers having alkoxysilyl groups such as γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, and vinyltrimethoxysilane.

<Method for producing copolymer (A)>
The copolymer (A) of the present invention can be obtained by copolymerizing the above-mentioned monomer mixture. The copolymer structure may be any of random copolymers, alternating copolymers, block copolymers, and graft copolymers, but a random copolymer is preferred from the viewpoints of improving the effects of the antifogging agent composition, including antifogging properties, and facilitating the preparation of the antifogging agent composition. Various known polymerization methods, such as radical polymerization, cationic polymerization, living radical polymerization, living anionic polymerization, and living cationic polymerization, are used to obtain the copolymer. Radical polymerization is particularly preferred from the viewpoints of ease of industrial productivity and a wide range of performances. Examples of radical polymerization methods include conventional bulk polymerization, suspension polymerization, solution polymerization, and emulsion polymerization, but solution polymerization is preferred because the polymerized product can be used as an antifogging agent composition directly.

Examples of polymerization solvents used in the solution polymerization method include alcohol-based solvents such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, isobutanol, s-butanol, t-butanol, and diacetone alcohol; alcohol ether-based solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, 3-methoxy-1-butanol, and 3-methoxy-3-methyl-1-butanol; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based solvents such as tetrahydrofuran and dioxane; ester-based solvents such as methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl lactate, and ethyl lactate; aromatic solvents such as benzene, toluene, and xylene; amide-based solvents such as formamide and dimethylformamide; and water. These polymerization solvents may be used alone or in combination.

The radical polymerization initiator may be a commonly used organic peroxide, azo compound, or the like. Examples of organic peroxides include benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-hexanoate, t-butylperoxyneodecanoate, t-hexylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, t-butylperoxypivalate, and t-hexylperoxypivalate. Examples of azo compounds include 2,2'-azobisisobutyronitrile and 2,2'-azobis-2-methylbutyronitrile. The radical polymerization initiators may be used alone or in combination of two or more.

The amount of the radical polymerization initiator added is preferably 0.01 to 5 parts by mass per 100 parts by mass of the monomer mixture. It is preferable to carry out the polymerization while adding the radical polymerization initiator dropwise to the reaction vessel, as this makes it easier to control the heat generated by polymerization. The temperature at which the polymerization reaction is carried out varies depending on the type of radical polymerization initiator used, but for industrial production it is preferably 30 to 150°C, and more preferably 50 to 100°C.

The weight average molecular weight (Mw) of the copolymer (A) is preferably 50,000 or more, and more preferably 100,000 or more, from the viewpoint of imparting water resistance to the anti-fogging film. The weight average molecular weight (Mw) of the copolymer (A) is preferably 400,000 or less, and more preferably 300,000 or less, from the viewpoint of improving the coatability and handleability of the anti-fogging agent composition.

The weight average molecular weight (Mw) of the copolymer (A) can be determined by a GPC method using a sample prepared by dissolving the sample in tetrahydrofuran to prepare a 0.2% by mass solution and filtering the solution through a 0.5 μm membrane filter under the following conditions.
<Measurement of weight average molecular weight (Mw)>
Analytical equipment: HLC-8320GPC (manufactured by Tosoh Corporation)
Column: KD-802.5 (Showa Denko K.K.), KD-803 (Showa Denko K.K.), KD-80M (Showa Denko K.K.) connected in series Column size: 8.0 x 300 mm
Eluent: tetrahydrofuran Flow rate: 1.0 mL/min
Detector: differential refractometer Column temperature: 40°C
Standard sample: polystyrene

<Polyfunctional Blocked Isocyanate Compound (B)>
The multifunctional blocked isocyanate compound (B) of the present invention is a compound having two or more isocyanate groups per molecule, in which the isocyanate groups are blocked with a blocking agent. The multifunctional blocked isocyanate compound (B) is not particularly limited as long as it undergoes a crosslinking reaction with the copolymer (A) to form a cured film. At least one type of multifunctional blocked isocyanate compound (B) may be used, or two or more types may be used in combination.

In the polyfunctional blocked isocyanate compound (B), examples of compounds having two or more isocyanate groups per molecule include diisocyanate group-containing compounds such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, tetramethylxylidene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, trimethylhexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,3-(isocyanatomethyl)cyclohexane, and 1,5-naphthalene diisocyanate; and derivatives of these diisocyanate group-containing compounds such as biuret, isocyanurate, adduct, and allophanate. Among these, from the viewpoint of suppressing yellowing, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,3-(isocyanatomethyl)cyclohexane, and derivatives thereof are preferred.

Furthermore, examples of the blocking agent include compounds such as dialkyl malonate, 3,5-dimethylpyrazole, ε-caprolactam, phenol, methyl ethyl ketoxime, and alcohol. Among these, dialkyl malonate is preferred from the viewpoint of its good low-temperature curing properties.

As the polyfunctional blocked isocyanate compound (B), from the viewpoints of low-temperature curing properties and low yellowing, it is preferable to use an isocyanurate or biuret of hexamethylene diisocyanate blocked with dialkyl malonate.

The amount of the polyfunctional blocked isocyanate compound (B) is preferably 3 parts by mass or more and 30 parts by mass or less relative to 100 parts by mass of the copolymer (A). From the viewpoint of improving the water resistance and moisture resistance of the anti-fogging film and reducing the appearance of water drip marks, the amount is preferably 5 parts by mass or more, and more preferably 8 parts by mass or more. From the viewpoint of improving the anti-fogging performance and adhesion of the anti-fogging film and suppressing whitening of water drip marks, the amount is preferably 20 parts by mass or less, and more preferably 15 parts by mass or less.

The ratio of the copolymer (A) to the polyfunctional blocked isocyanate compound (B) used is preferably such that the equivalent ratio (NCO/OH) of the isocyanate groups of the polyfunctional blocked isocyanate compound (B) to the hydroxyl groups of the copolymer (A) is 0.05 or more and 0.60 or less, and from the viewpoint of improving the water resistance and moisture resistance of the anti-fogging film and reducing the appearance of water drip marks, it is more preferably 0.10 or more, and even more preferably 0.20 or more, and from the viewpoint of improving the anti-fogging performance and adhesion of the anti-fogging film, it is more preferably 0.50 or less, and even more preferably 0.40 or less.

A catalyst may also be used to promote the crosslinking reaction. Examples of such catalysts include metal organic compounds such as tin octoate, dibutyltin di(2-ethylhexanoate), dioctyltin di(2-ethylhexanoate), dioctyltin diacetate, dibutyltin dilaurate, and dibutyltin fatty acid salts; and tertiary amines such as tetramethylbutanediamine, 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]undecene-7, and 1,5-diazabicyclo[4.3.0]nonene-5.

<Surfactant (C)>
The surfactant (C) of the present invention may be at least one selected from the group consisting of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants, and may be used in combination of two or more types.

Examples of the anionic surfactant include fatty acid salts such as fatty acid alkali metal salts, such as sodium oleate and potassium oleate; higher alcohol sulfates, such as sodium lauryl sulfate and ammonium lauryl sulfate; alkylbenzene sulfonates and alkylnaphthalene sulfonates, such as sodium dodecylbenzene sulfonate and sodium alkylnaphthalene sulfonate; naphthalene sulfonate-formaldehyde condensates, dialkyl sulfosuccinates, dialkyl phosphate salts, and polyoxyethylene sulfate salts, such as sodium polyoxyethylene alkylphenyl ether sulfate; and fluorine-containing anionic surfactants, such as perfluoroalkyl group-containing carboxylates, perfluoroalkyl group-containing sulfonates, perfluoroalkenyl group-containing sulfonates, and perfluoroalkyl group-containing phosphate esters. From the viewpoint of improving the anti-fogging performance of the anti-fogging film, perfluoroalkenyl group-containing sulfonates and dialkyl sulfosuccinates are preferred.

Examples of the cationic surfactant include amine salts such as ethanolamines, laurylamine acetate, triethanolamine monoformate, and stearamidoethyl diethylamine acetate; and quaternary ammonium salts such as lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, dilauryldimethylammonium chloride, distearyldimethylammonium chloride, lauryldimethylbenzylammonium chloride, stearyldimethylbenzylammonium chloride, tetrabutylammonium bromide, and lauryltrimethylammonium bromide. From the perspective of improving the anti-fogging performance of the anti-fogging film, quaternary ammonium salts are preferred.

Examples of the amphoteric surfactant include fatty acid-type amphoteric surfactants such as dimethyl alkyl lauryl betaine, dimethyl alkyl stearyl betaine, lauryl dimethyl aminoacetic acid betaine, and lauric acid amidopropyl dimethyl aminoacetic acid betaine; sulfonic acid-type amphoteric surfactants such as dimethyl alkyl sulfobetaine; amine oxide-type amphoteric surfactants such as alkyl (or alkenyl) dimethyl amine oxide, alkyl (or alkenyl) di(hydroxyethyl) amine oxide, polyoxyethylene alkyl (or alkenyl) ether dimethyl amine oxide, and polyoxyethylene alkyl (or alkenyl) ether di(hydroxyethyl) amine oxide; and amino acid-type amphoteric surfactants such as alkyl glycine. Fatty acid-type amphoteric surfactants are preferred from the viewpoint of improving the anti-fogging performance of the anti-fogging film.

Examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene isodecyl ether, polyoxyethylene lauryl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenol and polyoxyethylene nonylphenol; polyoxyethylene acyl esters such as polyoxyethylene monolaurate and polyoxyethylene monostearate; polyoxyethylene sorbitan fatty acid esters such as polypropylene glycol ethylene oxide adduct, polyoxyethylene sorbitan monolaurate, and polyoxyethylene sorbitan monostearate; phosphate esters such as alkyl phosphate esters and polyoxyethylene alkyl ether phosphate esters; sugar esters, cellulose ethers, and polyether macromers. From the viewpoint of improving the anti-fogging performance of the anti-fogging film, polyoxyethylene alkyl ethers and polyether macromers are preferred.

From the viewpoint that good anti-fogging performance can be obtained with a relatively small amount of surfactant (C), it is preferable to use a combination of an anionic surfactant and a cationic surfactant, or a combination of an anionic surfactant and an amphoteric surfactant, and it is even more preferable to use a nonionic surfactant in combination.

The surfactant (C) is preferably present in an amount of 0.5 to 5 parts by mass per 100 parts by mass of the copolymer (A). From the viewpoint of improving the anti-fogging performance of the anti-fogging film, the surfactant (C) is more preferably present in an amount of 1 part by mass or more, and even more preferably present in an amount of 1.5 parts by mass or more, per 100 parts by mass of the copolymer (A). From the viewpoint of improving the transparency of the anti-fogging film and suppressing whitening due to dripping water, the surfactant (C) is more preferably present in an amount of 4 parts by mass or less, and even more preferably present in an amount of 3 parts by mass or less. When an anionic surfactant and a cationic surfactant are used in combination, the mass ratio of the cationic surfactant to the anionic surfactant is preferably 0.01 to 0.50. When an anionic surfactant and an amphoteric surfactant are used in combination, the mass ratio of the amphoteric surfactant to the anionic surfactant is preferably 0.02 to 2.00. When an anionic surfactant and a cationic surfactant are used in combination with a nonionic surfactant, the mass ratio of the nonionic surfactant to the total of the anionic surfactant and the cationic surfactant is preferably 0.02 to 2.00; when an anionic surfactant and an amphoteric surfactant are used in combination with a nonionic surfactant, the mass ratio of the nonionic surfactant to the total of the anionic surfactant and the amphoteric surfactant is preferably 0.02 to 2.00.

<Solvent (D)>
The solvent (D) of the present invention contains at least a dihydric alcohol (D-1) and a glycol ether (D-2).

<Dihydric Alcohol (D-1)>
The dihydric alcohol (D-1) is a compound represented by the following general formula (7):
HO-R ¹⁵ -OH...(7)
(In general formula (7), R ¹⁵ is a linear, branched, or cyclic alkylene group having 1 to 10 carbon atoms.)

Examples of the dihydric alcohol (D-1) include 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,3-pentanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol, and 1,4-hexanediol. Examples of diols include 1,5-hexanediol, 1,6-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5-hexanediol, 3,4-hexanediol, 2-methyl-2,4-pentanediol, 1,2-heptanediol, 1,3-heptanediol, 1,4-heptanediol, 1,5-heptanediol, 1,6-heptanediol, 1,7-heptanediol, 2,3-heptanediol, 2,4-heptanediol, 2,5-heptanediol, 2,6-heptanediol, 3,4-heptanediol, 3,5-heptanediol, 4,5-heptanediol, and 2-ethyl-1,3-hexanediol.

From the viewpoint of suppressing dripping during coating, the dihydric alcohol (D-1) preferably has a boiling point of 240°C or less or has 8 or fewer carbon atoms, more preferably has a boiling point of 220°C or less or has 7 or fewer carbon atoms, and even more preferably has a boiling point of 210°C or less or has 6 or fewer carbon atoms. It is sufficient to use at least one type of dihydric alcohol (D), and two or more types can be used in combination.

The dihydric alcohol (D-1) is present in an amount of 5 to 35 parts by mass per 100 parts by mass of the antifogging composition. From the viewpoint of suppressing solvent cracking, the dihydric alcohol (D-1) is preferably present in an amount of 10 to 100 parts by mass of the antifogging composition, and more preferably 15 to 100 parts by mass. From the viewpoint of suppressing poor drying and reduced adhesion during heat curing, the amount is preferably present in an amount of 30 to 100 parts by mass, and more preferably 25 to 100 parts by mass.

<Glycol Ether (D-2)>
The glycol ether (D-2) is a compound represented by the following general formula (8).
R ¹⁶ -O-R ¹⁷ -OH...(8)
(In general formula (8), R ¹⁶ is a linear, branched, or cyclic alkyl group having 1 to 8 carbon atoms, and R ¹⁷ is a linear or branched alkylene group having 1 to 4 carbon atoms.)

Examples of the glycol ether (D-2) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-isopropyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-isobutyl ether, ethylene glycol mono-t-butyl ether, ethylene glycol mono-n-hexyl ether, ethylene glycol mono-n-octyl ether, ethylene glycol mono-2-ethylhexyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-isopropyl ether, propylene glycol mono-n-butyl ether, propylene glycol mono-isobutyl ether, propylene glycol mono-t-butyl ether, 3-methoxy-1-butanol, and 3-methoxy-3-methyl-1-butanol.

From the viewpoint of suppressing solvent cracking, the glycol ether (D-2) preferably has a boiling point of 180°C or less, or the total number of carbon atoms of R ¹⁶ and R ¹⁷ in the general formula (8) is 8 or less, and more preferably 160°C or less, or the total number of carbon atoms of R ¹⁶ and R ¹⁷ in the general formula (8) is 6 or less, and even more preferably 130°C or less, or the total number of carbon atoms of R ¹⁶ and R ¹⁷ in the general formula (8) is 4 or less. At least one type of glycol ether (D-2) may be used, or two or more types may be used in combination.

The glycol ether (D-2) is present in an amount of 3 to 15 parts by mass per 100 parts by mass of the antifogging composition. From the viewpoint of dissolving the copolymer (A) and surfactant (C), the glycol ether (D-2) is preferably present in an amount of 5 parts by mass or more, and more preferably 8 parts by mass or more, per 100 parts by mass of the antifogging composition. From the viewpoint of suppressing solvent cracking, the amount is preferably present in an amount of 12 parts by mass or less, and more preferably 10 parts by mass or less.

The mass ratio of the dihydric alcohol (D-1) to the glycol ether (D-2) [(D-1)/(D-2)] is 0.5 or more and 8.0 or less, and from the viewpoint of suppressing dripping during application, it is preferably 1.0 or more, and more preferably 2.0 or more, and from the viewpoint of suppressing solvent cracking, it is preferably 6.0 or less, and more preferably 4.0 or less.

<Colloidal silica>
The antifogging agent composition of the present invention can contain colloidal silica from the viewpoint of improving adhesion. The colloidal silica is fine particles of silica dispersed in a dispersion medium, and known colloidal silica can be used. From the viewpoint of the transparency of the antifogging film, the colloidal silica preferably has a particle diameter of 100 nm or less, more preferably 50 nm or less, and from the viewpoint of adhesion, the particle diameter is preferably 5 nm or more. The particle diameter is represented by the cumulant average particle diameter measured by dynamic light scattering. The colloidal silica may be used alone or in combination of two or more types.

Examples of the dispersion medium include water; alcohol-based solvents such as methanol, ethanol, isopropanol, 1-propanol, isobutanol, and 1-butanol; polyhydric alcohol-based solvents such as ethylene glycol; polyhydric alcohol derivatives such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and ethylene glycol monopropyl ether; ketone-based solvents such as methyl ethyl ketone, methyl isobutyl ketone, and diacetone alcohol; amide-based solvents such as dimethylacetamide; ester-based solvents such as ethyl acetate; and aromatic hydrocarbon-based solvents such as toluene.

Commercially available colloidal silica includes, for example, water-dispersed colloidal silica sol (trade names: Snowtex O, Snowtex OS, Snowtex O-40, Snowtex OXS, etc.), methanol-dispersed colloidal silica (trade name: Methanol Silica Sol), isopropanol-dispersed colloidal silica (trade name: IPA-ST), ethylene glycol-dispersed colloidal silica (trade name: EG-ST), ethylene glycol mono-n-propyl ether-dispersed colloidal silica (trade name: NPC-ST-30), and propylene glycol monomethyl ether. Examples of suitable colloidal silica dispersions include colloidal silica (trade name: PGM-ST), colloidal silica dispersed in dimethylacetamide (trade name: DMAC-ST), colloidal silica dispersed in methyl ethyl ketone (trade name: MEK-ST-40), colloidal silica dispersed in methyl isobutyl ketone (trade name: MIBK-ST), colloidal silica dispersed in ethyl acetate (trade name: EAC-ST), colloidal silica dispersed in propylene glycol monomethyl ether acetate (trade name: PMA-ST), and colloidal silica dispersed in toluene (trade name: TOL-ST) (all manufactured by Nissan Chemical Industries, Ltd.). To improve anti-fogging performance, the colloidal silica is preferably dispersed in water or a hydrophilic solvent.

When the colloidal silica is used, it is preferably 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the copolymer (A). From the viewpoint of improving adhesion, the amount of the colloidal silica is more preferably 0.5 parts by mass or more, and even more preferably 1 part by mass or more, per 100 parts by mass of the copolymer (A). From the viewpoint of improving transparency and anti-fogging performance, it is more preferably 8 parts by mass or less, and even more preferably 5 parts by mass or less.

<Amino acid compounds>
The antifogging agent composition of the present invention can contain an amino acid compound from the viewpoint of reducing water drip marks. The amino acid compound of the present invention is an organic compound having one or more amino groups and one or more carboxy groups in the same molecule, and any conventionally known amino acid compound can be used, including natural aliphatic amino acids, natural aromatic amino acids, non-natural aliphatic amino acids, and non-natural aromatic amino acids. From the viewpoint of suppressing whitening due to drip marks, the amino acid compound may be an aminobenzoic acid compound, which is a non-natural aromatic amino acid, such as 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, 2-amino-3-hydroxybenzoic acid, 3-amino-4-hydroxybenzoic acid, anthranilic acid, 4-aminosalicylic acid, 4-amino-3-hydroxybenzoic acid, 5-aminosalicylic acid, 5-aminoisophthalic acid, 2-aminoterephthalic acid, 3,5-diaminobenzoic acid, 4-aminophthalic acid, and 3,4-diaminobenzoic acid. Hydroxy group-containing aminobenzoic acid compounds are more preferred, such as 2-amino-3-hydroxybenzoic acid, 3-amino-4-hydroxybenzoic acid, anthranilic acid, 4-aminosalicylic acid, 4-amino-3-hydroxybenzoic acid, and 5-aminosalicylic acid. At least one of the amino acid compounds may be used, and two or more of them may be used in combination.

When the amino acid compound is used, it is preferably present in an amount of 0.01 parts by mass or more and 5.00 parts by mass or less per 100 parts by mass of the copolymer (A). From the viewpoint of suppressing whitening due to dripping water marks, the amount of the amino acid compound is more preferably 0.05 parts by mass or more, and even more preferably 0.10 parts by mass or more per 100 parts by mass of the copolymer (A). From the viewpoint of improving anti-fogging performance and improving adhesion, it is more preferably present in an amount of 4.00 parts by mass or less, and even more preferably 3.00 parts by mass or less.

The anti-fogging agent composition of the present invention may further contain a diluent solvent.

The dilution solvent is used to adjust the solids content and viscosity of the anti-fog composition to suit its application. As the dilution solvent, it is preferable to use a monohydric alcohol-based solvent, which is thought to have little effect on solvent cracking in resin substrates, such as ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, and t-butanol. The solids content and viscosity suitable for application of the dilution solvent vary, but typically, it is preferably approximately 10 to 50 parts by weight, and more preferably approximately 20 to 40 parts by weight, per 100 parts by weight of the anti-fog composition.

The antifogging agent composition of the present invention may contain, as other components, various conventional additives such as leveling agents, curing catalysts, antioxidants, UV absorbers, and light stabilizers, as needed. The amount of each of the other components added may be the conventional amount for each additive, but is typically 5 parts by mass or less per 100 parts by mass of the copolymer (A).

<Anti-fog article>
The anti-fogging article of the present invention is obtained by applying the anti-fogging agent composition to an object to be coated by a coating method typically used for coating paints, followed by heat curing, thereby forming an anti-fogging film on the surface of the object to be coated.

The substrate to be coated can be any known resin substrate, including, for example, polymethyl methacrylate resin, polycarbonate resin, polystyrene resin, acrylonitrile-styrene copolymer resin, polyvinyl chloride resin, acetate resin, ABS resin, polyester resin, and polyamide resin.

When applying the anti-fog composition to the substrate, it is preferable to remove any foreign matter adhering to the surface of the substrate before application in order to increase the wettability of the anti-fog composition on the substrate and prevent repellency. Examples of methods include dust removal using high-pressure air or ionized air, ultrasonic cleaning with a detergent solution or alcohol solvent, wiping using an alcohol solvent, and cleaning with ultraviolet light and ozone. Examples of application methods include dipping, flow coating, roll coating, bar coating, and spray coating.

In order to achieve good anti-fogging properties and good coating appearance, the thickness of the anti-fogging film is preferably approximately 0.5 to 10 μm, and more preferably approximately 1 to 5 μm.

The anti-fogging article is not limited in its intended use, but can be used, for example, in vehicle lighting fixtures for automobiles. Examples of such vehicle lighting fixtures include headlights, auxiliary headlights, width lights, license plate lights, tail lights, parking lights, reversing lights, turn signals, auxiliary turn signals, and emergency flashers.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples.

<Production of Copolymer (A)>
A reaction vessel equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a cooling tube was charged with 250 parts by mass of n-butyl acetate as a polymerization solvent and heated to 60 ° C. while blowing in nitrogen gas. Next, a solution containing 30 parts by mass of N,N-dimethylacrylamide (manufactured by KJ Chemicals, trade name "DMAA") as monomer (A-1), 10 parts by mass of cyclohexyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) as monomer (A-2), 45 parts by mass of tetrahydrofurfuryl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) as monomer (A-3), 15 parts by mass of 2-hydroxyethyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) as monomer (A-4), 50 parts by mass of 1-butanol, and 0.5 parts by mass of t-butyl neodecanoate (manufactured by NOF Corporation, trade name "Perbutyl ND", active ingredient 70% by mass) as a radical polymerization initiator was added dropwise to the reaction vessel over 2 hours. After the dropwise addition was completed, the mixture was stirred for another 2 hours while maintaining the temperature at 60°C. The temperature was then raised to 70°C, and the mixture was heated and stirred for 2 hours, and then cooled to produce a solution of copolymer (A). The polymerization conversion of the charged monomers of copolymer (A) was measured by gas chromatography and found to be 99% or more. Furthermore, the weight average molecular weight of copolymer (A) was measured by gel permeation chromatography and found to be 250,000. The solids content of this copolymer (A) solution was 25% by mass. The hydroxyl value (theoretical value) of copolymer (A) was 72 mgKOH/g.

Example 1
<Production of anti-fogging agent composition>
To 400 parts by mass of the solution containing 100 parts by mass of the copolymer (A) obtained above, 200 parts by mass of 2,3-butanediol as the dihydric alcohol (D-1), 100 parts by mass of propylene glycol monomethyl ether as the glycol ether (D-2), and 300 parts by mass of 1-butanol as a dilution solvent were added, and the concentration of the diluted solution of copolymer (A) was adjusted to 10% by mass. Next, 14 parts by mass of an isocyanurate of hexamethylene diisocyanate blocked with dialkyl malonate (manufactured by Asahi Kasei Corporation, trade name "Duranate MF-K60B", active ingredient 60% by mass) as the polyfunctional blocked isocyanate compound (B), 2.0 parts by mass of sodium di(2-ethylhexyl)sulfosuccinate (manufactured by NOF Corporation, trade name "Rapisol A80", active ingredient 80% by mass) as the surfactant (C), 0.1 part by mass of dodecyltrimethylammonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass), and 1.0 part by mass of polyoxyethylene isodecyl ether (manufactured by NOF Corporation, trade name "Nonion ID-209", active ingredient 100% by mass), and 0.02 part by mass of polyether-modified polydimethylsiloxane (manufactured by BYK-Chemie KK, trade name "BYK-333") as a leveling agent were mixed together to produce an antifogging agent composition.

<(1) Evaluation of Solvent Cracks>
Assuming a case where the temperature rises suddenly during heat curing, a substrate (polycarbonate resin plate) is left to stand for 2 hours in a dryer set to a heating temperature of 120°C or 130°C, and one drop (about 20 mg) of the antifogging composition obtained above is attached to the substrate (polycarbonate resin plate) when the temperature reaches 120°C or 130°C. The substrate (polycarbonate resin plate) with the antifogging composition attached is returned to the dryer and heat-cured for 20 minutes, after which the appearance of the droplet portion is observed with a laser microscope and evaluated according to the following four-point scale. Note that an evaluation of C or higher is acceptable for practical use.
A: At a heating temperature of 130°C, no abnormality was observed in the appearance of the antifogging agent composition-applied portion.
B: At a heating temperature of 130°C, abnormalities were observed in the appearance of the antifogging composition-adhered portion, but at a heating temperature of 120°C, no abnormalities were observed in the appearance of the antifogging composition-adhered portion.
C: At a heating temperature of 120°C, slight abnormalities were observed in the appearance of the antifogging agent composition-applied site.
D: At a heating temperature of 120°C, abnormalities were observed in the appearance of the antifogging agent composition-adhered portion.

<(2) Evaluation of paintable film thickness>
The anti-fog composition obtained above was spray-coated onto a 15 cm x 15 cm substrate (polycarbonate resin plate), and the substrate (polycarbonate resin plate) was placed upright in a dryer set to 120°C and heat-cured for 20 minutes. The test piece was removed from the dryer, and the thickness of the anti-fog film on the coated product, which had been visually confirmed to have no dripping, was measured and rated on the following three-point scale. A rating of B or higher was acceptable for practical use.
A: The maximum film thickness is 5 μm or more.
B: The maximum film thickness is less than 5 μm and 4 μm or more.
C: The maximum film thickness is less than 4 μm.

<(3) Brushing evaluation>
The antifogging agent composition obtained above was spray-coated onto a substrate (polycarbonate resin plate) in an atmospheric environment of 30°C and 90% RH so that the thickness of the coating film after curing would be approximately 2 to 4 μm, and the plate was left in the same environment for 10 minutes. Next, heat curing was carried out at 120°C for 20 minutes to obtain a test piece. The coating film produced by the above method was visually observed and rated on the following three-point scale. A rating of B or higher indicates no practical problems.
A: No abnormalities such as bleaching were observed.
B: Partial bleaching is observed.
C: Whitening is observed throughout.

<Preparation of Anti-Fog Article>
The antifogging agent composition obtained above was spray coated onto a substrate (polycarbonate resin plate) in an atmospheric environment of 25°C and 30% RH so that the thickness of the coating film after curing would be about 2 to 4 μm, and the coating was then heat-cured at 120°C for 20 minutes to prepare an antifogging article (test piece) having an antifogging film.

Table 1 shows the results obtained using the test specimens obtained above and the evaluation methods (4) to (7) below.

<(4) Initial Adhesion>
The presence or absence of peeling of the coating film was visually evaluated according to JIS K 5400 8.5.1 using the following three-level scale: A rating of B or higher indicates no practical problem.
A: No peeling was observed.
B: A small amount of peeling is observed.
C: Completely peeled off.

<(5) Adhesion after moisture resistance test>
The test pieces were left to stand at 50°C and 95% RH for 240 hours or 1000 hours, and then left to stand at room temperature for 1 hour. After that, the presence or absence of peeling of the coating film was visually evaluated according to JIS K 5400 8.5.1 using the following three-level evaluation. A rating of C or higher indicates no practical problems.
A: No peeling was observed after 1000 hours of humidity resistance test.
B: Peeling was observed after 1000 hours of the humidity resistance test, but no peeling was observed after 240 hours.
C: A small amount of peeling was observed after 240 hours of the humidity resistance test.
D: Partial or complete peeling occurred after 240 hours of humidity resistance test.

<(6) Steam Anti-Fog Property>
The test piece was placed with the coating surface facing downwards at a height of 2 cm above the water surface of a hot water bath maintained at 80°C, and the coating was continuously irradiated with steam from the hot water bath. The presence or absence of cloudiness after 10 seconds of irradiation was visually evaluated on the following four-point scale. A rating of B or higher was deemed acceptable for practical use.
A: No cloudiness is observed.
B: Clouding is observed, but the clouding disappears within 10 seconds of steam irradiation.
C: After 10 seconds of steam irradiation, an uneven water film was observed on part or all of the surface.

<(7) Water drip marks>
The test piece was placed with the coating surface facing downwards at a height of 2 cm above the water surface of a hot water bath maintained at 80°C, and steam from the hot water bath was continuously irradiated onto the coating for 30 seconds. After that, the test piece was held upright and the drips were dried at room temperature for 10 to 15 minutes. This process was repeated 10 times, and the resulting drip marks were visually evaluated on the following three-point scale. A rating of B or higher was acceptable for practical use.
A: Water drip marks are barely noticeable.
B: Water drip marks are slightly noticeable or slightly white.
C: Water drip marks are noticeable or white.

<Examples 2 to 44, Comparative Examples 1 to 9>
<Production of anti-fogging agent composition and fabrication of anti-fogging article>
In each of the Examples and Comparative Examples, antifogging agent compositions of Examples 2 to 44 and Comparative Examples 1 to 9 were produced 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 shown in Tables 1 to 4. Furthermore, antifogging articles (test pieces) having antifogging films of Examples 2 to 44 and Comparative Examples 1 to 9 were produced in the same manner as in Example 1.

Tables 1 to 4 show the results obtained for the anti-fogging agent composition and anti-fogging film obtained above using the evaluation methods (1) to (7) above.

In Tables 1 to 4, monomers (A-1) to (A-4) are:
DMAA is N,N-dimethylacrylamide (manufactured by KJ Chemicals, trade name "DMAA");
DEAA is N,N-diethylacrylamide (manufactured by KJ Chemicals, trade name "DEAA");
CHA is cyclohexyl acrylate (Tokyo Chemical Industry Co., Ltd.);
EHA is 2-ethylhexyl acrylate (Tokyo Chemical Industry Co., Ltd.);
IBOA is isobornyl acrylate (Tokyo Chemical Industry Co., Ltd.);
THFA is tetrahydrofurfuryl acrylate (Tokyo Chemical Industry Co., Ltd.);
CTFA is cyclic trimethylolpropane formal acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat #200, CTFA");
GMA is glycidyl methacrylate (Tokyo Chemical Industry Co., Ltd.);
HEA is 2-hydroxyethyl acrylate (Tokyo Chemical Industry Co., Ltd., hydroxyl value 483 mg KOH/g);
HBA is 4-hydroxybutyl acrylate (Tokyo Chemical Industry Co., Ltd., hydroxyl value 389 mg KOH/g);
HEAA refers to 2-hydroxyethyl acrylamide (manufactured by KJ Chemicals, trade name "HEAA", hydroxyl value 487 mg KOH/g).

In Tables 1 to 4, the polyfunctional blocked isocyanate compound (B) is
Duranate MF-K60B is an isocyanurate of hexamethylene diisocyanate blocked with dialkyl malonate (manufactured by Asahi Kasei Corporation, active ingredient 60% by mass, NCO content 6.5% by mass);
Duranate WM44-L70G is an isocyanurate of hexamethylene diisocyanate blocked with dialkyl malonate (manufactured by Asahi Kasei Corporation, active ingredient 70% by mass, NCO content 5.3% by mass).

In Tables 1 to 4, surfactants (C) are:
Rapisol is sodium di(2-ethylhexyl)sulfosuccinate (manufactured by NOF Corporation, trade name "Rapisol A-80", active ingredient 80% by mass);
Pelex TR is sodium ditridecyl sulfosuccinate (manufactured by Kao Corporation, trade name "Pelex TR", active ingredient 70% by mass);
F100 is perfluoroalkenyl sulfonate (manufactured by Neos Co., Ltd., active ingredient 100% by mass);
DTAB: dodecyltrimethylammonium bromide (Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass);
TBAB: tetrabutylammonium bromide (Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass);
BL-SF is lauryl dimethylaminoacetic acid betaine (manufactured by NOF Corporation, trade name "Nissan Anon BL-SF", active ingredient 35.5% by mass);
BDL-SF is lauramidopropyl dimethylaminoacetic acid betaine (manufactured by NOF Corporation, trade name "Nissan Anon BDL-SF", active ingredient 30% by mass);
DM10 is decyldimethylamine oxide (manufactured by Lion Specialty Chemicals, trade name "Cadenax DM10D-W", active ingredient 40% by mass).
DM14 is myristyl dimethylamine oxide (manufactured by Lion Specialty Chemicals, trade name "Cadenax DM14D-N", active ingredient 25% by mass);
ID-209 is polyoxyethylene isodecyl ether (NOF Corporation, trade name "Nonion ID-209", active ingredient 100% by mass);
Softanol 120 is a polyoxyethylene alkyl ether (manufactured by Nippon Shokubai Co., Ltd., "Softanol 120", active ingredient 100% by mass);
BYK-3560 represents a polyether macromer-modified acrylate (manufactured by BYK-Chemie, active ingredient 100% by mass).

In Tables 1 to 4, the dihydric alcohol (D-1) is
23BD is 2,3-butanediol (Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass, boiling point 182°C);
HG is 2-methyl-2,4-pentanediol (Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass, boiling point 197°C);
13PD is 1,3-propanediol (Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass, boiling point 214°C);
14BD is 1,4-butanediol (Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass, boiling point 228°C);
3M15PD indicates 3-methyl-1,5-pentanediol (manufactured by Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass, boiling point 250°C).

In Tables 1 to 4, the glycol ether (D-2) is
PGM is propylene glycol monomethyl ether (Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass, boiling point 120°C);
EGtBE is ethylene glycol mono-t-butyl ether (Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass, boiling point 152°C);
MMB: 3-methoxy-3-methyl-1-butanol (Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass, boiling point 174°C);
EGHE represents ethylene glycol monohexyl ether (manufactured by Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass, boiling point 208°C).

In Tables 1 to 4, the colloidal silica is
Snowtex O is a water-dispersed colloidal silica sol (manufactured by Nissan Chemical Industries, Ltd., active ingredient 20% by mass, particle size 12 nm);
Snowtex N refers to a water-dispersed colloidal silica sol (manufactured by Nissan Chemical Industries, Ltd., active ingredient 20% by mass, particle size 12 nm).

In Tables 1 to 4, the amino acid compounds are:
4ABA is 4-aminobenzoic acid (Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass);
4ASA refers to 4-aminosalicylic acid (manufactured by Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass).

In Tables 1 to 4, the leveling agents are
BYK-333 refers to polyether-modified polydimethylsiloxane (manufactured by BYK-Chemie, active ingredient 100% by mass).

In Tables 1 to 4, the dilution solvents are:
NBA represents 1-butanol (manufactured by Tokyo Chemical Industry Co., Ltd., active ingredient 100% by mass).

Claims (3)

An antifogging agent composition comprising a copolymer (A), a polyfunctional blocked isocyanate compound (B), a surfactant (C), and a solvent (D),
The copolymer (A) is a (meth)acrylate copolymer obtained from a monomer mixture containing a monomer (A-1) represented by the following general formula (1):
(In general formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is a linear or branched alkyl group having 1 to 4 carbon atoms, -C(CH ₃ ) ₂ CH ₂ COCH ₃ , -C ₂ H ₄ N(CH ₃ ) ₂ , or -C ₃ H ₆ N(CH ₃ ) ₂ , and R ³ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.)
the solvent (D) contains a dihydric alcohol (D-1) and a glycol ether (D-2),
The dihydric alcohol (D-1) is a compound represented by the following general formula (7):
HO-R ¹⁵ -OH...(7)
(In general formula (7), R ¹⁵ is a linear, branched, or cyclic alkylene group having 1 to 10 carbon atoms.)
The glycol ether (D-2) is a compound represented by the following general formula (8):
R ¹⁶ -O-R ¹⁷ -OH...(8)
(In general formula (8), R ¹⁶ is a linear, branched, or cyclic alkyl group having 1 to 8 carbon atoms, and R ¹⁷ is a linear or branched alkylene group having 1 to 4 carbon atoms.)
the dihydric alcohol (D-1) is contained in an amount of 5 parts by mass or more and 35 parts by mass or less, and the glycol ether (D-2) is contained in an amount of 3 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the antifogging agent composition;
an antifogging agent composition, wherein the mass ratio of the dihydric alcohol (D-1) to the glycol ether (D-2) [(D-1)/(D-2)] is 0.5 or more and 8.0 or less. The monomer mixture comprises a monomer (A-2) represented by the following general formula (2),
one or more monomers (A-3) selected from the group consisting of monomers represented by the following general formula (3) and monomers represented by the following general formula (4),
The antifogging agent composition according to claim 1, characterized in that it contains one or more monomers (A-4) selected from the group consisting of monomers represented by the following general formula (5) and monomers represented by the following general formula (6):
(In general formula (2), ^R4 is a hydrogen atom or a methyl group, and ^R5 is a linear, branched, or cyclic hydrocarbon group having 1 to 18 carbon atoms.)
(In general formula (3), ^R6 is a hydrogen atom or a methyl group, ^R7 is a linear alkylene group having 1 to 4 carbon atoms, and ^R8 is a substituent having a heterocyclic skeleton.)
(In general formula (4), ^R9 is a hydrogen atom or a methyl group, and ^R10 is a substituent having a heterocyclic skeleton.)
(In general formula (5), R ¹¹ is a hydrogen atom or a methyl group, R ¹² is a linear or branched alkylene group having 2 to 4 carbon atoms, or —C ₂ H ₄ (OCO(CH ₂ ) ₅ ) _n —, where n is 1 to 5.)
(In general formula (6), R ¹³ is a hydrogen atom or a methyl group, and R ¹⁴ is a linear or branched alkylene group having 1 to 4 carbon atoms.) An anti-fogging article comprising an anti-fogging film formed on a substrate from the anti-fogging agent composition described in claim 1 or 2.