JP2023106722A - Application agent for forming anti-fogging coating, method for producing anti-fogging article, and anti-fogging article - Google Patents

Abstract

To provide a one-pack application agent for forming anti-fogging coating capable of effectively removing hair dyes and gargles and preventing the occurrence of swelling when water scale is removed, a method for producing an anti-fogging article using the application agent for forming anti-fogging coating, and an anti-fogging article.SOLUTION: An application agent for forming an anti-fogging coating contains (A) a polyisocyanate having two or more isocyanate groups, (B) a polyol having an oxyethylene unit as a repeat unit and having three or more hydroxy groups in each molecule, and (C) a solvent. There are also provided a method for producing an anti-fogging article using the application agent for forming anti-fogging coating, and an anti-fogging article.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present disclosure relates to an antifogging film-forming coating agent, a method for producing an antifogging article, and an antifogging article.

In order to ensure the visibility of transparent substrates such as mirrors for bathrooms and washstands, window glass of automobiles and lenses of cameras, it is strongly desired to impart anti-fogging function to the surface of these substrates. ing.

Fogging that occurs on the main surface of a glass substrate such as a mirror or glass is caused by a dew condensation phenomenon in which countless minute water droplets are formed on the surface of the substrate. In order to prevent this fogging, there are hydrophilic coatings that form a uniform water film with countless minute water droplets on the substrate surface, and water-absorbing coatings that exhibit anti-fogging properties by incorporating water vapor and water droplets into the coating. is being investigated on a substrate.

In recent years, not only anti-fogging properties but also anti-fouling properties that make it difficult for dirt to adhere to the surface of substrates are sometimes required. Patent Document 1 discloses a structure in which a polyurethane film and a film made of a cured product of a composition containing an antifouling agent are laminated on a substrate in order to impart antifouling properties in addition to antifogging properties. An anti-fogging article is described.

Further, Patent Document 2 discloses an anti-fogging film-forming composition containing an isocyanate compound, a copolymer polyol, an acrylic polyol, and a surfactant with a specific structure, wherein the contents of the isocyanate compound and the acrylic polyol are within a specific range. A coating is described.

Japanese Patent Application Laid-Open No. 2021-4350 Japanese Patent No. 6578479

In Patent Document 1, an antifogging article having excellent antifogging properties and antifouling properties is obtained by providing a polyurethane coating on a substrate and further laminating a coating comprising a composition containing an antifouling agent thereon.

In Patent Document 1, at least two kinds of coating agents, namely, a coating agent for forming a polyurethane film and a coating agent containing an antifouling agent, are required, and the coating process must be performed at least twice.

In addition, Patent Document 2 describes a coating agent for forming an anti-fogging film that achieves both hydrophilicity and scratch resistance. , hair dyes and gargles may adhere, and an anti-fogging article excellent in removability of these is required. Further, there is a demand for an anti-fogging article that is less likely to swell when water scale adhering to its surface is removed.

An object of the present disclosure is to provide a coating agent for forming an anti-fogging film that is a one-liquid material, has excellent hair dye and mouthwash removability, and is less likely to swell when water scale is removed.

In addition, the present disclosure provides an anti-fogging article capable of producing an anti-fogging article that is excellent in hair dye removability and mouthwash removability by a single application step and that does not easily swell when water scale is removed. The purpose is to provide a method.

Furthermore, the present disclosure provides an anti-fogging article having a single-layer anti-fogging coating that is excellent in hair dye and mouthwash removability, and is less likely to swell when water scale is removed. aim.

The problem of the present disclosure is solved by the following configuration.
<1>
(A) a polyisocyanate having two or more isocyanate groups;
(B) a polyol comprising an oxyethylene unit as a repeating unit and having three or more hydroxy groups in the molecule;
(C) a solvent;
A coating agent for forming an antifogging film, comprising:
<2>
The coating agent for forming an antifogging film according to <1>, wherein the polyol (B) is a branched polyol.
<3>
The coating agent for forming an antifogging film according to <1>, wherein the polyol (B) is a cyclic polyol.
<4>
The coating agent for forming an antifogging film according to any one of <1> to <3>, further comprising (D) a water repellent agent or (E) a hydrophilic agent.
<5>
n _{( NCO) /n (OH), which is the ratio of the number n (NCO)} of isocyanate groups in the urethane-forming component to the number n _{(OH) of} hydroxyl groups in the urethane-forming component, is 1.0 to 3.0; The coating agent for forming an antifogging film according to any one of <1> to <4>.
<6>
For forming an antifogging film according to any one of <1> to <5>, wherein the content of the polyisocyanate (A) is 25 to 75% by mass with respect to 100% by mass of the urethane-forming component. Coating agent.
<7>
The coating for forming an antifogging film according to any one of <1> to <6>, wherein the content of the polyol (B) is 25 to 75% by mass with respect to 100% by mass of the urethane-forming component. agent.
<8>
The antifogging coating according to <4>, wherein the content of the water repellent agent (D) or hydrophilic agent (E) is 0.001 to 10.0% by mass with respect to 100% by mass of the urethane-forming component. Forming coating.
<9>
A method for producing an antifogging article having a substrate and an antifogging coating, comprising:
A step (1) of applying the coating agent for forming an antifogging film according to any one of <1> to <8> to the surface of a substrate to form a coating film;
Step (2) of evaporating the solvent (C) from the coating film and curing the coating film to form an antifogging coating;
A method for manufacturing an anti-fogging article.
<10>
The method for producing an antifogging article according to <9>, wherein the substrate is a glass substrate.
<11>
The method for producing an antifogging article according to <10>, wherein the surface of the glass substrate is coated with a silane coupling agent.
<12>
According to any one of <9> to <11>, in the step (2), the isocyanate groups of the polyisocyanate (A) react with the hydroxy groups of the polyol (B) to form a polyurethane. A method for producing an antifogging article.
<13>
The method for producing an antifogging article according to any one of <9> to <12>, wherein in the step (2), the coating film is heated at 80 to 170°C.
<14>
An antifogging article having a substrate and an antifogging coating,
The anti-fogging coating is a coating containing a polyurethane resin, which is a cured product of the coating agent for forming an anti-fogging coating according to any one of <1> to <8>,
The film thickness of the antifogging coating is 5 μm to 50 μm,
Anti-fogging article.
<15>
The antifogging article according to <14>, wherein the substrate is a glass substrate.
<16>
The antifogging article according to <15>, wherein the surface of the glass substrate is coated with a silane coupling agent.
<17>
Water is dropped on the surface of the anti-fogging coating placed horizontally, dried at 60° C. for 1 hour, and then water scale is removed. 14> to <16>, the antifogging article according to any one of the above items.

According to the present disclosure, it is possible to provide an anti-fogging film-forming coating agent that is a one-liquid, excellent in hair dye removability and mouthwash removability, and less likely to swell when water scale is removed.

In addition, according to the present disclosure, an anti-fogging article can be manufactured that is excellent in hair dye removability and mouthwash removability in a single application step and that is less likely to swell when water scale is removed. can provide a manufacturing method of

Furthermore, according to the present disclosure, there is provided an anti-fogging article having a single-layer anti-fogging coating that is excellent in hair dye and mouthwash removability, and is less likely to swell when water scale is removed. be able to.

[Coating agent for forming anti-fogging film]
The coating agent for forming an antifogging film of the present disclosure is
(A) a polyisocyanate having two or more isocyanate groups;
(B) a polyol comprising an oxyethylene unit as a repeating unit and having three or more hydroxy groups in the molecule;
(C) a solvent;
It is a coating agent for forming an antifogging film containing.
<(A) Polyisocyanate Having Two or More Isocyanate Groups>
(A) A polyisocyanate having two or more isocyanate groups (also referred to as “polyisocyanate (A)”) will be described.

The polyisocyanate (A) serves as a skeleton component of the antifogging coating (also simply referred to as "coating"), and can impart water absorbency and hardness to the coating.

The polyisocyanate (A) is not particularly limited, and examples thereof include compounds having 2 to 5 isocyanate groups. Specific examples include hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, and bis(methylcyclohexyl). diisocyanate, toluene diisocyanate, and the like.

Further, the polyisocyanate (A) may be a polymer (e.g., dimer, trimer, etc.), or at least one selected from the group consisting of an allophanate structure, an adduct structure, a biuret structure and an isocyanurate structure. It may have a seed structure. For example, it may be a dimer using hexamethylene diisocyanate as a starting material, a compound having an allophanate structure using hexamethylene diisocyanate as a starting material, or a compound having a biuret structure using hexamethylene diisocyanate as a starting material. When the polyisocyanate (A) is a polymer, the number average molecular weight is preferably 100-20,000, more preferably 150-5,000, and particularly preferably 200-2,000.

The isocyanate groups of polyisocyanate (A) may be blocked isocyanate groups. The polyisocyanate (A) having blocked isocyanate groups is also called "blocked polyisocyanate (AH)".

A blocked isocyanate group is a group in which an isocyanate group is protected with a blocking agent, and the blocking agent is dissociated by heat treatment to regenerate the isocyanate group.

The blocked polyisocyanate (AH) is not particularly limited, and may be, for example, one in which the isocyanate groups of the aforementioned polyisocyanate are protected with a known blocking agent.

Also, the blocked polyisocyanate (AH) preferably has a urethane bond (--NHCOO--) in its molecule.

The number average molecular weight of the blocked polyisocyanate (AH) is preferably 100-20,000, more preferably 150-5,000, and particularly preferably 200-2,000.
<(B) Polyol Having Oxyethylene Units as Repeating Units and Having 3 or More Hydroxy Groups in the Molecule>
(B) A polyol having oxyethylene units as repeating units and having three or more hydroxy groups in the molecule (also referred to as "polyol (B)") will be described.

The polyol (B) can impart water absorbency to the antifogging coating by having oxyethylene units as repeating units. Having an oxyethylene unit as a repeating unit means that "-(CH ₂ CH ₂ O) _p -" is included in the molecule. p represents an integer of 2 or more.

The polyol (B) is not particularly limited. Both (B2) may be included.

The copolymerized polyol (B2) is a polyether obtained by ring-opening polymerization of ethylene oxide and propylene oxide using a phosphazene compound, a Lewis acid compound or an alkali metal compound catalyst as an initiator, followed by block addition or random addition. Polyols can be used.

The molar ratio of oxyethylene units/oxypropylene units in the copolymerized polyol (B2) may be from 45/55 to 90/10, preferably from 70/30 to 80/20.

The number average molecular weight of the polyol (B) is more preferably 200-10,000, still more preferably 300-5,000, and particularly preferably 400-2,000.

Polyol (B) is preferably a branched polyol (polyol having a branched structure in the molecule) or a cyclic polyol (polyol having a cyclic structure such as a four-, five-, or six-membered ring in the molecule). . Examples of branched polyols include trimethylolpropane ethoxylate, pentaerythritol ethoxylate, polyoxyethylene (13) polyglyceryl ether, and the like. Six-membered ring polyols include, for example, polyoxyethylene methyl glucoside (methyl gluceth-10, methyl gluceth-20, etc.), polyoxyethylene sorbitan monolaurate, and the like. Moreover, both a branched polyol and a cyclic polyol may be used as the polyol (B).

Polyol (B) is commercially available, for example, trimethylolpropane ethoxylate and pentaerythritol ethoxylate manufactured by Sigma-Aldrich, polyoxyethylene (13) polyglyceryl ether manufactured by Sakamoto Yakuhin Kogyo (trade name "SCE-750 ”), NOF Methyl Gluceth-10 (trade name “Macbiobride MG-10E”), NOF Methyl Gluceth-20 (trade name “Macbiobride MG-20E”), Sanyo Kasei Polymonolaurate oxyethylene sorbitan (trade name “Polysorbate T-20C”) and the like.
<(C) Solvent>
(C) The solvent (also referred to as “solvent (C)”) will be described.

As the solvent (C), it is preferable to use an acetate solvent or ketones. Specifically, the acetate solvents include amyl acetate, allyl acetate, isoamyl acetate, isobutyl acetate, isopropyl acetate, ethyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, n-butyl acetate, s- butyl, propyl acetate, benzyl acetate, methyl acetate, methyl cyclohexyl acetate and the like. Ketones include acetylacetone, acetone, isophorone, ethyl-n-butyl ketone, diisobutyl ketone, diisopropyl ketone, diethyl ketone, cyclohexanone, di-n-propyl ketone, methyl oxide, methyl-n-amyl ketone, methyl isobutyl ketone, methyl ethyl ketone, Methylcyclohexanone, methyl-n-butyl ketone, methyl-n-propyl ketone, methyl-n-hexyl ketone, methyl-n-heptyl ketone, diacetone alcohol, mixtures thereof and the like. Particularly preferred are isobutyl acetate, n-butyl acetate, s-butyl acetate and methyl ethyl ketone.
<(D) water repellent>
The coating agent for forming an antifogging film of the present disclosure may contain (D) a water repellent agent (also referred to as “water repellent agent (D)”).

The water repellent (D) is a component that imparts antifouling properties to the antifogging coating.

The water repellent (D) is not particularly limited, but preferably contains at least one compound selected from the group consisting of (D1), (D2) and (D3) below.

(D1) has at least one group selected from the group consisting of a hydroxy group, a functional group that produces a hydroxy group by hydrolysis, a carboxy group, an amino group, and an isocyanate group, and a dialkylsiloxane moiety (SiR ₂ O, R is Linear polydialkylsiloxane (also referred to as “compound (D1)”) having an average number of 5 to 400 linear or branched alkyl groups each independently representing a linear or branched alkyl group having 1 to 10 carbon atoms. )
(D2) a fluoroalkylsilane having at least one group selected from the group consisting of a hydroxy group, a functional group that produces a hydroxy group upon hydrolysis, a carboxy group, an amino group, and an isocyanate group, and having a fluorocarbon moiety (“Compound (D2)".)
(D3) a perfluoropolyether having at least one group selected from the group consisting of a hydroxy group, a functional group that produces a hydroxy group upon hydrolysis, a carboxy group, an amino group, and an isocyanate group, and having a fluorocarbon moiety (" Also referred to as "compound (D3)".)
Examples of the functional group that produces a hydroxy group upon hydrolysis in the compounds (D1), (D2) and (D3) include an alkoxy group, preferably a linear or branched alkoxy group having 1 to 6 carbon atoms, specifically Specific examples include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a butoxy group.
(Compound (D1))
Since compound (D1) has a dialkylsiloxane moiety with excellent lubricity, it can impart antifouling properties to the film.

In the compound (D1), the average number of dialkylsiloxane moieties (SiR ₂ O) is preferably 20 to 50 in order to obtain a film having better antifouling properties and durability.

R of SiR ₂ O is preferably a methyl group or an ethyl group, more preferably a methyl group.

As the compound (D1), for example, polydimethylsiloxane represented by the following general formula [1] is preferably used.

In general formula [1], X ¹ and X ² each independently represent a monovalent or divalent functional group. a and b are each independently an integer of 0-3, and n is an integer of 10-400. However, a + b is 1 or more, and at least one of X ¹ and X ² is at least selected from the group consisting of a hydroxy group, a functional group that produces a hydroxy group by hydrolysis, a carboxy group, an amino group, and an isocyanate group. is one.

Specific examples of monovalent or divalent functional groups represented by X ¹ and X ² include a hydroxy group, an amino group, an epoxy group, a carboxy group, an acryloyl group, an allyl group, a mercapto group, and -C(=O)-OR. ¹ group (R ¹ represents a linear or branched saturated alkyl group having 1 to 4 carbon atoms), -O-C(=O)R ¹ group (R ¹ is -C(=O)-OR ¹ group R ¹ ), -A ¹ -B ¹ group (A ¹ represents a divalent organic group, B ¹ is a hydroxy group, amino group, epoxy group, -C(=O)-OR ¹ group ( R ¹ represents a linear or branched saturated alkyl group having 1 to 4 carbon atoms) or -O-C(=O)R ¹ group (R ¹ is -C(=O)-OR ¹ group of R ¹ )), -A ¹ -C (A ² ) (A ³ B ² ) (A ⁴ B ³ ) group (A ¹ represents a divalent organic group, A ² represents a hydrogen atom or a monovalent A ³ and A ⁴ each independently represent a divalent organic group, B ² or B ³ each independently represents a hydroxy group, an amino group, an epoxy group, a carboxy group, an acryloyl group , allyl group, mercapto group, -C(=O)-OR ¹ group (R ¹ represents a linear or branched saturated alkyl group having 1 to 4 carbon atoms) or -OC(=O)R ¹ group (R ¹ is the same as R ¹ of -C(=O)-OR ¹ group).
(Compound (D2))
The fluorocarbon moiety in compound (D2) is preferably _CF2 or _CF3 .

As the compound (D2), a fluoroalkylsilane having a functional group at one end represented by the following general formula [2], or a fluoroalkyl having a functional group at both ends represented by the following general formula [3] Silane is preferably used.

In general formula [2], each Y ¹ independently represents a monovalent functional group. p is an integer of 1 to 3 and represents the number of functional groups. m is an integer of 2-6. However, at least one ^Y1 represents at least one selected from the group consisting of a hydroxy group, a functional group that produces a hydroxy group upon hydrolysis, a carboxy group, an amino group, and an isocyanate group.

In general formula [3], Y ² and Y ³ each independently represent a monovalent functional group. m is an integer from 2 to 6 and represents the number of fluorocarbon moieties. q and r are each independently an integer of 1 to 3 and represent the number of monovalent functional groups. However, at least one of ^Y2 and ^Y3 represents at least one selected from the group consisting of a hydroxy group, a functional group that produces a hydroxy group upon hydrolysis, a carboxy group, an amino group, and an isocyanate group.

Compound (D2) has a fluorocarbon moiety that has excellent antifouling properties and removability against fouling components such as sebum components, fingerprints, and water stains, as well as durability, so it is effective in improving the antifouling properties and durability of the obtained film. play.

In addition, a perfluoroalkyl group (CF ₃ (CF ₂ ) _t-1 -) or a perfluoroalkylene group (-(CF ₂ ) _u -) having 2 to 6 fluorocarbon moieties in the molecule of the compound (D2) is preferred. Increasing the number of fluorocarbon moieties increases the durability of the resulting antifouling coating. t and u represent integers, and the "-" indicates a bond.
(Compound (D3))
The fluorocarbon moiety in compound (D3) is preferably _CF2 or _CF3 .

As the compound (D3), one represented by any one of the following general formulas [4] to [6] is preferable.

In general formula [4], Rf1 is a structure represented by the formula: -C _p F _2p O- (p is an integer of 1 to 6), or -C _q F _2q - (q is 1 to is an integer of 8.). Each Z independently represents a linear or branched alkoxy group having 1 to 6 carbon atoms, and specific groups include methoxy, ethoxy, propoxy, isopropoxy and butoxy. R is an alkyl group having 1 to 10 carbon atoms, and a is an integer of 1 to 3. n and n' are each integers of 1 to 5; m and m' are each integers of 0 to 2;

In general formula [5], r represents an integer of 1-200. Each Z independently represents a linear or branched alkoxy group having 1 to 6 carbon atoms, and specific groups include methoxy, ethoxy, propoxy, isopropoxy and butoxy.

In general formula [6], s represents an integer of 1-100, and t represents an integer of 1-10. Each Z independently represents a linear or branched alkoxy group having 1 to 6 carbon atoms, and specific groups include methoxy, ethoxy, propoxy, isopropoxy and butoxy.

Similarly to compound (D2), compound (D3) has antifouling properties and removability against staining components such as sebum components, fingerprints, and water stains, and has a fluorocarbon moiety that is excellent in durability. Effective in improving stain resistance and durability.
<(E) hydrophilic agent>
The coating agent for forming an antifogging film of the present disclosure may contain (E) a hydrophilic agent (also referred to as “hydrophilic agent (E)”).

Although the hydrophilic agent (E) is not particularly limited, a compound represented by any one of the following general formulas [7] to [9] is preferred.

[In general formula [7], X is a single bond, an alkylene group having 1 to 10 carbon atoms which may have a substituent, or an arylene group having 6 to 18 carbon atoms which may have a substituent. Y represents either a single bond, an ester bond, an amide bond, a sulfonate ester bond, a sulfonate amide bond, or an ether bond. However, when X is a single bond, Y also becomes a single bond together with X. Also, n is a natural number from 2 to 22. ]

[In the general formula [8], X is a single bond, an alkylene group having 1 to 10 carbon atoms which may have a substituent, or an arylene group having 6 to 18 carbon atoms which may have a substituent. Y represents either a single bond, an ester bond, an amide bond, a sulfonate ester bond, a sulfonate amide bond, or an ether bond. However, when X is a single bond, Y also becomes a single bond together with X. Also, n is a natural number from 2 to 22. ]

[In general formula [9], R is a linear, branched or cyclic alkyl group having 10 to 22 carbon atoms. ]
The fluorine-containing compounds represented by general formula [7] and general formula [8] impart an antifouling function to the antifogging article of the present disclosure, and also act as a surfactant. Furthermore, these surfactants are free of isocyanate-reactive groups such as hydroxyl groups, mercapto groups and amino groups. Here, the antifouling property refers to the staining resistance to staining components such as sebum components, fingerprints and water stains, and the removability of the staining components.

In the present disclosure, the fluorine-containing surfactant represented by the general formula [7] and the quaternary ammonium salt represented by the general formula [9] are preferable from the viewpoint of not reducing the hydrophilicity and hardness.

In the quaternary ammonium salt represented by the general formula [9], R is preferably a linear, branched or cyclic alkyl group having 15 to 22 carbon atoms, and a linear, branched or cyclic alkyl group having 16 to 20 carbon atoms. or more preferably a cyclic alkyl group.

A surfactant that is solid at room temperature (eg, the quaternary ammonium salt) may crystallize a small amount of the surfactant present on the surface of the film, making the film cloudy. Therefore, surfactants that are liquid at room temperature (for example, fluorine-containing surfactants represented by general formula [7]) are more preferable. Further, in the fluorine-containing surfactant represented by the general formula [7], in the general formula [7], X and Y are preferably single bonds, and n is preferably a natural number of 8 to 16. , 9 to 13 natural numbers.
<(F) Polytetramethylene ether glycol>
The coating agent for forming an antifogging film of the present disclosure may further contain (F) polytetramethylene ether glycol (also referred to as "polytetramethylene ether glycol (F)"). The number average molecular weight of the polytetramethylene ether glycol (F) is preferably 100-4000, more preferably 500-2000, particularly preferably 800-1200.
<(G) Short-chain polyol having a number average molecular weight of 60 to 200>
The coating agent for forming an antifogging film of the present disclosure may further contain (G) a short-chain polyol having a number average molecular weight of 60 to 200 (also referred to as “short-chain polyol (G)”).

The short chain polyol (G) is a polyol having a short chain length and having a number average molecular weight in the range of 60-200.

By containing the short-chain polyol (G), the hardness of the coating is likely to be improved. The number of hydroxyl groups per molecule of the short-chain polyol (G) may be 2 or 3.

Examples of short-chain polyols (G) include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2 , 3-butanediol, 1,5-pentanediol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol , triethylene glycol, glycerin, 2-ethyl-2-(hydroxymethyl)-1,3-propanediol, 1,2,6-hexanetriol, alkyl polyols such as 2,2′-thiodiethanol, diethanolamine, triethanol Examples include alkanolamines such as amines, and they can be used alone, as a mixture, or as a copolymer having a number average molecular weight in the range of 60-200.

Among these, ethylene glycol and triethylene glycol are preferable from the viewpoint of improving the hardness of the film, and 1,2-propanediol, 1,2-butanediol, 1,3-butanediol and 2,3-butanediol are preferred. Such short-chain polyols having secondary or tertiary hydroxyl groups, which are less active than primary hydroxyl groups, are preferable from the viewpoint of the stability of the coating solution (prolonged pot life).
<Urethane-forming component>
As used herein, the term “urethane-forming component” refers to, among the components contained in the coating agent for forming an anti-fogging film of the present disclosure, components that are raw materials for forming polyurethane, water repellent (D) and All components except hydrophilic agent (E).

Typically, the "urethane-forming component" is polyisocyanate (A), polyol (B), polytetramethylene ether glycol (F), and short-chain polyol in the antifogging film-forming coating agent of the present disclosure. Represents (G).

When the coating agent for forming an antifogging film of the present disclosure contains polyisocyanate (A) and polyol (B), and does not contain polytetramethylene ether glycol (F) and short-chain polyol (G), " "Urethane-forming components" are polyisocyanate (A) and polyol (B).

In other cases as well, the "urethane-forming component" is considered in the same manner as above.
<Content of each component>
The content of the polyisocyanate (A) in the coating agent for forming an antifogging film of the present disclosure is preferably 25 to 75% by mass, more preferably 30 to 70% by mass, based on 100% by mass of the urethane-forming component. more preferably 35 to 70% by mass.

The content of the polyol (B) in the coating agent for forming an antifogging film of the present disclosure is preferably 25 to 75% by mass, more preferably 30 to 70% by mass, based on 100% by mass of the urethane-forming component. is more preferable, and 30 to 65% by mass is even more preferable.

The content of the solvent (C) in the anti-fogging film-forming coating agent of the present disclosure is, for example, such that the solid content concentration in the anti-fogging film-forming coating agent of the present disclosure is 10 to 50% by mass. , can be adjusted. The solid content refers to all components excluding the solvent (C) from all components in the coating agent for forming an antifogging film of the present disclosure, and the solid content concentration is the concentration (content) of the solid content. is.

When the coating agent for forming an antifogging film of the present disclosure contains a water repellent agent (D) or a hydrophilic agent (E), the water repellent agent (D) in the coating agent for forming an antifogging film of the present disclosure or The content of the hydrophilic agent (E) is preferably 0.001 to 10.0% by mass, more preferably 0.005 to 5.0% by mass, relative to 100% by mass of the urethane-forming component. , more preferably 0.01 to 2.0% by mass.

When the coating agent for forming an antifogging film of the present disclosure contains polytetramethylene ether glycol (F), the content of polytetramethylene ether glycol (F) in the coating agent for forming an antifogging film of the present disclosure is preferably 5 to 15% by mass, more preferably 8 to 10% by mass, based on 100% by mass of the urethane-forming component.

When the coating agent for forming an antifogging film of the present disclosure contains a short-chain polyol (G), the content of the short-chain polyol (G) in the coating agent for forming an antifogging film of the present disclosure is It is preferably 1 to 15% by mass, more preferably 2 to 10% by mass, and even more preferably 3 to 8% by mass, based on 100% by mass of the component.
<n _(NCO) /n _(OH) >
n _(NCO) /n, which is the ratio of the number n _(NCO) of isocyanate groups in the urethane-forming component and the number n _(OH) of hydroxyl groups in the urethane-forming component in the coating agent for forming an antifogging film of the present disclosure _(OH) is preferably 1.0 to 3.0, more preferably 1.1 to 2.5, even more preferably 1.2 to 2.0.

The number of blocked isocyanate groups is also included in the number n of isocyanate groups (NCO).
<Other components and their content>
The coating agent for forming an anti-fogging film of the present disclosure is cured to increase the curing speed when forming an anti-fogging film by curing the coating film formed by applying the coating agent for forming an anti-fogging film. It may contain a catalyst.

When the coating agent for forming an antifogging film of the present disclosure contains a curing catalyst, the content of the curing catalyst in the coating agent for forming an antifogging film of the present disclosure is It is preferably 0.001 to 0.5% by mass.

Examples of curing catalysts include organic metal compounds such as organic tin compounds, organic titanium compounds, organic zirconium compounds and organic bismuth compounds, and amine compounds.

The coating agent for forming an antifogging film of the present disclosure may contain a leveling agent that promotes the smoothness of the coating film on the substrate.

When the coating agent for forming an anti-fogging film of the present disclosure contains a leveling agent, the content of the leveling agent in the coating agent for forming an anti-fogging film of the present disclosure is It is preferably 0.01 to 0.50% by mass, more preferably 0.05 to 0.25% by mass.

The coating agent for forming an antifogging film of the present disclosure may contain additives that improve the heat resistance, weather resistance, and water resistance of the coating film.

Examples of the additives include hindered amine-based light stabilizers, benzotriazole-based ultraviolet absorbers, hindered phenol-based antioxidants, carbodiimide-based hydrolysis inhibitors, and the like. The above additives may be used singly or in combination.

When the coating agent for forming an anti-fogging film of the present disclosure contains the above additive, the content of the additive in the coating agent for forming an anti-fogging film of the present disclosure is 0.2 to 10.0% by mass, more preferably 0.5 to 2.0% by mass.

The application of the coating agent for forming an anti-fogging film of the present disclosure is not particularly limited. Glass or mirrors, specifically rearview mirrors, door mirrors, etc., and other openings such as glasses, camera lenses, goggles, helmet shields, refrigerated showcases, freezer showcases, testing machines, precision equipment cases, etc. Examples include observation windows, road reflectors, displays of mobile communication devices such as mobile phones, and the like.
[Method for producing antifogging article]
The manufacturing method of the anti-fogging article of the present disclosure comprises:
A method for manufacturing an antifogging article having a substrate and an antifogging coating, comprising:
a step (1) of applying the coating agent for forming an antifogging film of the present disclosure to the surface of a substrate to form a coating film;
Step (2) of evaporating the solvent (C) from the coating film and curing the coating film to form an antifogging coating;
A method for manufacturing an antifogging article, comprising:

An antifogging article is obtained by performing the above step (1) and the above step (2) in this order.
<Base material>
As the base material, a plate-like one is preferably used, and glass is typically used. The glass is plate glass made of soda-lime glass, which is commonly used for automotive, architectural, and industrial glass, and is plate glass produced by the float method, duplex method, roll-out method, or the like, and the manufacturing method is not particularly limited.

Glass types include various colored glasses such as clear, green, bronze, etc., various functional glasses such as UV, IR cut glass, electromagnetic shielding glass, and fireproof glass such as wired glass, low expansion glass, and zero expansion glass. Various glass products such as glass, tempered glass and similar glass, laminated glass and multi-layer glass, mirrors produced by the silver coating method or vacuum film forming method, and flat plates and bent plates can be used.

The plate thickness of the substrate is not particularly limited, but is preferably 1 mm or more and 10 mm or less, and particularly preferably 1 mm or more and 5 mm or less.

The formation of the antifogging coating on the surface of the substrate may be carried out on only one side of the substrate, or on both sides depending on the application. Moreover, the formation of the antifogging coating may be performed on the entire surface of the base material or on a part of the base material surface.

The surface of the glass substrate is preferably coated with a primer component such as a silane coupling agent in order to improve the adhesion between the glass substrate and the antifogging coating. When applying the silane coupling agent to the substrate, the silane coupling agent may be diluted with alcohol, water, or the like to about 0.05 to 2.0% by mass. Examples of the silane coupling agent include aminosilane, mercaptosilane and epoxysilane. Silane coupling agents having an amino group are particularly preferred, and γ-glycidoxypropyltrimethoxy, γ-aminopropyltriethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane and the like are particularly preferred. Thus, the step of applying a solution containing the above coupling agent to the base material is a particularly preferable embodiment in which the adhesiveness between the base material and the coating is improved.

It is preferable that the base material is a glass base material and that a silane coupling agent having an amino group is applied to the surface of the glass base material.

The substrate may be a resin film such as polyethylene terephthalate, a resin such as polycarbonate, or the like, in addition to the glass substrate. An anti-fogging article may be obtained by forming the anti-fogging film on the surface of these resinous transparent substrates, and the article may be attached to a glass substrate.
<Step (1)>
Step (1) is a step of applying the coating agent for forming an antifogging film of the present disclosure to the surface of a substrate to form a coating film.

Before the step (1), the base material described above and the coating agent for forming the antifogging film of the present disclosure described above are prepared.

The coating agent for forming an antifogging film of the present disclosure can be applied to a substrate by known means such as dip coating, flow coating, spin coating, roll coating, spray coating, screen printing, and flexographic printing. .
<Step (2)>
Step (2) is a step of evaporating the solvent (E) from the coating film and curing the coating film to form an antifogging coating.

Curing the coating specifically refers to reacting raw materials in the coating to form polyurethane and to solidify the coating.

In step (2), it is preferred that the isocyanate groups of the polyisocyanate (A) react with the hydroxy groups of the polyol (B) to form a polyurethane.

In step (2), the film is left at room temperature or heat-treated at 170° C. or less to cure the coating film and evaporate the solvent (C), thereby solidifying the coating film to form an antifogging coating.

In order to promote curing of the coating film, heating is preferably performed at 80 to 170°C, more preferably at 100 to 165°C, and even more preferably at 120 to 160°C.
[Anti-fogging article]
The anti-fogging article of the present disclosure is
An antifogging article having a substrate and an antifogging coating,
The antifogging coating is a coating containing polyurethane, which is a cured product of the coating agent for forming an antifogging coating of the present disclosure,
The film thickness of the antifogging coating is 5 μm to 50 μm,
It is an antifogging article.

The base material of the antifogging article is as described in [Method for producing antifogging article]. In particular, it is preferable that the base material is a glass base material, and that the surface of the glass base material is coated with a silane coupling agent having an amino group.

The thickness of the antifogging coating is 5 μm to 50 μm, preferably 10 μm to 45 μm, more preferably 15 μm to 40 μm, particularly preferably 20 μm to 30 μm.

The pencil hardness of the antifogging coating is preferably 2H or more, more preferably 3H or more.

The anti-fogging coating of the anti-fogging article is prepared by dripping water on the surface of the anti-fogging coating placed horizontally, drying at 60 ° C. for 1 hour, removing water scale, and swelling the part where water scale was attached. It is preferable that the step of the portion is 200 nm or less.

Examples of the present disclosure will be described below, but the present disclosure is not limited to the following examples.

In the present examples and comparative examples, a coating agent (coating solution) for forming an antifogging film for producing an antifogging article was prepared, and the coating film made of the coating solution applied on the substrate was heat-treated, An antifog article was produced by curing to an antifog coating. The method for preparing the coating liquid and the method for producing the antifogging article are as described below. Next, the obtained antifogging article was subjected to quality evaluation by the method shown below.

[Thickness of anti-fogging coating]: The thickness of the anti-fogging coating is measured by making a cut in the surface of the anti-fogging coating with a cutter, and using a surface roughness meter (Kosaka research Measured with Surfcorder ET-4000A manufactured by Shosha Co., Ltd., and the average value of 5 points was taken as the film thickness of the antifogging coating.

[Anti-fogging property]: The surface of the anti-fogging coating film of the anti-fogging article is exposed to saturated steam at 15°C in a room with a temperature of 10°C and a humidity of 30%. The antifogging time of the antifogging coating film was defined as the time when the surface of the antifogging coating film began to cloud. A value obtained by dividing the antifogging time by the film thickness was evaluated as the antifogging property.

[Pencil hardness]: In accordance with JIS K 5600 Paint general test method (1999), the surface of the anti-fogging coating film was scratched twice with a pencil loaded with a load of 750 g. The hardness of the pencil that was absent was taken as the pencil hardness of the antifogging coating film.

[Removability of hair dye]: A two-liquid mixed type hair coloring agent for gray hair (black brown) containing paraphenylenediamine was applied in a circular shape with a diameter of about 10 mm to the surface of the anti-fogging coating film, and left at room temperature for 1 hour. After allowing to stand at normal humidity (5-35°C, relative humidity 45-85%), the adhered portion is washed with water to wash off the hair coloring agent. After that, cotton soaked with a colorless and transparent neutral dishwashing detergent (5-fold dilution) is applied to the colored portion of the hair coloring agent, and after 1 hour, wipe off with a wet cotton cloth. After the test, CM-2600d (manufactured by Konica Minolta) is used to measure the color difference of the colored portion before and after the test. A color difference formula of ΔE94 (CIE1994) was used to calculate the color difference. The smaller the color difference value, the better the hair dye removability.

[Removability of mouthwash]: A povidone-iodine mouthwash is applied in a circular shape with a diameter of about 10 mm to the surface of the anti-fogging film and left for 1 hour at normal temperature and normal humidity (5-35°C, relative humidity 45-85%). After that, wash the attached part with water and wash off the gargle. Thereafter, a cotton pad soaked with a colorless and transparent neutral dishwashing detergent (diluted 5 times) is attached to the colored portion of the mouthwash, and after 1 hour, wipe off with a wet cotton cloth. After the test, CM-2600d (manufactured by Konica Minolta) is used to measure the color difference of the colored portion before and after the test. A color difference formula of ΔE94 (CIE1994) was used to calculate the color difference. The smaller the color difference value, the better the mouthwash removability.

[Water stain resistance test]: Tap water is dropped on the surface of the antifogging film placed horizontally, and dried at 60°C for 1 hour. After drying, the water scale is removed, and the step of the swollen part where the water scale has adhered is measured, and those that are difficult to visually confirm swelling (200 nm or less) are accepted (○), and those exceeding 200 nm are rejected ( x).
[Comparative Example 1]
(Preparation of anti-fogging coating liquid)
As an isocyanate, 23.70 g of a dimer-type polyisocyanate of hexamethylene diisocyanate (trade name “Desmodur N3200”; manufactured by Sumika Covestrourethane) was prepared, and this was used as a chemical agent A.

In addition, each component listed below was mixed in the following specified amounts to obtain a total amount of drug B of 78.12 g.
<Solvent>
Mixture of isobutyl acetate and diacetone alcohol; 60.00 g
Acetylacetone; 1.80 g
<Water absorbing polyol>
Oxyethylene/oxypropylene copolymer bifunctional polyol having a number average molecular weight of 4000 (trade name “Toho Polyol PB-4000”; manufactured by Toho Chemical Industry Co., Ltd.); 9.78 g
<Aliphatic Polyester Diol>
Aliphatic polyester diol having a number average molecular weight of 1250 (trade name “PLAXEL L212AL”; manufactured by Daicel; 4.89 g,
<Short chain polyol>
Ethylene glycol; 1.63 g
<Leveling agent>
Organically modified silicone substrate wetting agent KL-400HF (manufactured by Kyoeisha Chemical Co., Ltd.); 0.02 g
101.86 g of coating liquid 1 was prepared by mixing the above agents A and B, and adding 0.04 g of dibutyltin dilaurate (hereinafter referred to as DBTDL) as a curing catalyst.

When the total amount of Coating Liquid 1 was 100% by mass, the urethane-forming component in Coating Liquid 1 was 39% by mass. Also, based on the raw material of coating liquid 1, the number of isocyanate groups was 2.0 times the number of hydroxyl groups in the polyol. In coating liquid 1, the isocyanate compound is contained in an amount of 59.3% by mass with respect to 100% by mass of the total amount of urethane-forming components.
(Preparation of base material)
A mirror was prepared by forming a silver film on the back surface of a soda-lime glass plate having a rectangular shape and a size of 100 mm×100 mm×5 mm (thickness) by a conventional method. A mixed solution of 89 g of ion-exchanged water, 10 g of propanol, and 1 g of 3-(2-aminoethylamino)propyltrimethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) as an amino-based silane coupling agent were prepared. . Wipe the glass surface of the mirror with a wiper made of cellulose fiber (trade name “BEMCOT”, model M-1, 50 mm × 50 mm, manufactured by Ozu Sangyo) soaked with the mixed solution, then wash with water and apply a primer. A layered mirror was provided as a substrate.
(Formation of anti-fogging article)
The coating liquid 1 is applied by spin coating to the main surface of the substrate on which the primer layer is formed to form a coating film, and then heat treated at about 160 ° C. for about 10 minutes to obtain a film thickness of 18 μm. An antifogging article having a fogging coating was obtained.
[Example 1]
(Preparation of anti-fogging coating liquid)
As an isocyanate, 32.98 g of an isocyanurate-type polyisocyanate of hexamethylene diisocyanate (trade name “MHG-80B”; solid content concentration 80% by mass; manufactured by Asahi Kasei Corporation) was prepared. Let this be drug A.

In addition, each component listed below was mixed in the following specified amounts to obtain a total amount of drug B of 69.79 g.
<Solvent>
Mixture of isobutyl acetate and diacetone alcohol; 43.40 g
Acetylacetone; 2.25 g,
<Water absorbing polyol>
Pentaerythritol ethoxylate (15/4 EO/OH, branched polyol) of a tetrafunctional polyol with a number average molecular weight of 450 having the following structure (manufactured by Sigma-Aldrich); 23.62 g

ａ、ｂ、ｃ、ｄは正の整数であり、ａ＋ｂ＋ｃ＋ｄ＝１５である

a, b, c, d are positive integers and a+b+c+d=15

<Leveling agent>
Organically modified silicone substrate wetting agent KL-400HF (manufactured by Kyoeisha Chemical Co., Ltd.); 0.02 g
<Light stabilizer>
Hindered amine light stabilizer ADEKA STAB LA-72 (manufactured by ADEKA); 0.50 g
102.82 g of coating liquid 2 was prepared by mixing the above agents A and B and adding 0.05 g of dibutyltin dilaurate (hereinafter referred to as DBTDL) as a curing catalyst.

When the total amount of Coating Liquid 2 was 100% by mass, the urethane-forming component in Coating Liquid 2 was 49% by mass. Also, based on the raw material of coating liquid 2, the number of isocyanate groups was 1.0 times the number of hydroxyl groups in the polyol. In the coating liquid 2, the isocyanate compound is contained in an amount of 52.8% by mass with respect to 100% by mass of the total amount of the urethane-forming components.
(Preparation of base material)
A mirror was prepared by forming a silver film on the back surface of a soda-lime glass plate having a rectangular shape and a size of 100 mm×100 mm×5 mm (thickness) by a conventional method. A mixed solution of 89 g of ion-exchanged water, 10 g of propanol, and 1 g of amino-based silane coupling agent X-12-972F (manufactured by Shin-Etsu Chemical Co., Ltd.) were prepared. Wipe the glass surface of the mirror with a wiper made of cellulose fiber (trade name “BEMCOT”, model M-1, 50 mm × 50 mm, manufactured by Ozu Sangyo) soaked with the mixed solution, then wash with water and apply a primer. A layered mirror was provided as a substrate.
(Formation of anti-fogging article)
The coating liquid 2 is applied by spin coating to the main surface of the substrate on which the primer layer is formed to form a coating film, and then heat treatment is performed at about 160 ° C. for about 10 minutes to obtain a film thickness of 23 μm. An antifogging article having a fogging coating was obtained.
[Example 2]
In the agent B of Example 1, the water-absorbent polyol pentaerythritol ethoxylate was replaced with a trifunctional polyol trimethylolpropane ethoxylate (branched polyol) (manufactured by Sigma-Aldrich) having a number average molecular weight of 450 and having the following structure. Except for this, the same operation as in Example 1 was performed to obtain an antifogging article.

ｅ、ｆ、ｇは正の整数であり、ｅ＋ｆ＋ｇ＝２０

e, f, g are positive integers, e+f+g=20

[Example 3]
(Preparation of anti-fogging coating liquid)
45.05 g of blocked isocyanate (trade name “Duranate SBB70P”; solid content concentration 70% by mass; manufactured by Asahi Kasei Corporation) was prepared. Let this be drug A.

In addition, each component listed below was mixed in the following specified amounts to obtain a total amount of drug B of 57.71 g.
<Solvent>
Mixture of isobutyl acetate and diacetone alcohol; 36.49 g
Acetylacetone; 2.25g
<Water absorbing polyol>
Polyoxyethylene (13) polyglyceryl ether of a tetrafunctional polyol having a number average molecular weight of 738 and having the following structure (trade name “SCE-750” manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.); 18.47 g

Ｒはエチレンオキサイド（ＣＨ_２ＣＨ_２Ｏ）である。また、ｍ、ｎ、ｏ、ｐは正の整数であり、ｍ＋ｎ＋ｏ＋ｐ＝１３である。

R is ethylene _oxide ( _CH2CH2O ). Also, m, n, o, and p are positive integers, and m+n+o+p=13.

<Water repellent agent (antifouling agent)>
KF-6123 (manufactured by Shin-Etsu Chemical Co., Ltd.) of polydimethylsiloxane compound modified with polyether at both ends: 0.005 g
<Light stabilizer>
Hindered amine light stabilizer ADEKA STAB LA-72 (manufactured by ADEKA); 0.50 g
102.78 g of coating liquid 3 was prepared by mixing the above agents A and B and adding 0.025 g of dibutyltin dilaurate (hereinafter referred to as DBTDL) as a curing catalyst.

When the total amount of Coating Liquid 3 was 100% by mass, the urethane-forming component in Coating Liquid 3 was 49% by mass. In addition, based on the raw material of coating liquid 3, the number of isocyanate groups was 1.1 times the number of hydroxyl groups in the polyol. In coating liquid 3, the isocyanate compound is contained in an amount of 63.1% by mass with respect to 100% by mass of the total amount of urethane-forming components.

An antifogging article was obtained in the same manner as in Example 1 except that Coating Liquid 3 was used instead of Coating Liquid 2.
[Example 4]
(Preparation of anti-fogging coating liquid)
43.00 g of blocked isocyanate (trade name “Duranate SBB70P”; solid content concentration 70% by mass; manufactured by Asahi Kasei Corporation) was prepared. Let this be drug A.

In addition, each component listed below was mixed in the following specified amounts to obtain a total amount of drug B of 59.48 g.
<Solvent>
Mixture of isobutyl acetate and diacetone alcohol; 42.10 g
Acetylacetone; 2.03g
<Water absorbing polyol>
Methyl gluceth-10, a tetrafunctional polyol having a number average molecular weight of 634 and having the following structure (trade name “Macbiobride MG-10E”; manufactured by NOF Corporation, six-membered ring polyol); 14.90 g

ａ、ｂ、ｃ、ｄは正の整数であり、ａ＋ｂ＋ｃ＋ｄ＝１０である。

a, b, c, and d are positive integers, and a+b+c+d=10.

<Light stabilizer>
Hindered amine light stabilizer ADEKA STAB LA-72 (manufactured by ADEKA); 0.45 g
102.50 g of coating liquid 4 was prepared by mixing the above agents A and B and adding 0.023 g of dibutyltin dilaurate (hereinafter referred to as DBTDL) as a curing catalyst.

The urethane-forming component in the coating liquid 4 was 44% by mass when the total amount of the coating liquid 4 was 100% by mass. Also, based on the raw material of coating liquid 4, the number of isocyanate groups was 1.1 times the number of hydroxyl groups in the polyol. In coating liquid 4, the isocyanate compound is contained in an amount of 66.9% by mass with respect to 100% by mass of the total amount of urethane-forming components.

An antifogging article was obtained in the same manner as in Example 1, except that Coating Liquid 4 was used instead of Coating Liquid 2.
[Example 5]
An antifogging article was obtained in the same manner as in Example 4, except that 0.005 g of X-22-4952 (manufactured by Shin-Etsu Chemical Co., Ltd.) was added as a water repellent to the agent B of Example 4. .
[Example 6]
In the agent B of Example 5, the water-absorbing polyol "Macbiobride MG-10E" was replaced with "Methyl Gluceth-20" (trade name "Mac Biobride MG-20E"; made by NOF, six-membered ring polyol), and changed the water repellent agent from "X-22-4952" to KF-6123 (manufactured by Shin-Etsu Chemical Co., Ltd.), a polydimethylsiloxane compound modified with polyether at both ends ) was performed in the same manner as in Example 5 to obtain an antifogging article.
[Example 7]
In the drug B of Example 5, trimethylolpropane ethoxylate (hereinafter referred to as TEE) (manufactured by Sigma-Aldrich) was further added as a water-absorbing polyol, and the solid content mass ratio was changed to "Macbiobride MG-10E: TEE = 50. An antifogging article was obtained in the same manner as in Example 5, except that the content was changed to: 50.
[Example 8]
The water repellent agent "X-22-4952" of Example 5 was changed to one-end hexafluoropropene-modified polyoxyethylene compound Ftergent 212M (manufactured by Neos) as a hydrophilic agent; The same operation as in Example 5 was performed to obtain an antifogging article.

The results are shown in Table 1 below.

From the results in Table 1, the coating agents for forming an anti-fogging film of Examples 1 to 8 are one-liquid, excellent in hair dye removability and mouthwash removability, and swelling occurs when water scale is removed. It was found to be a coating agent for forming an anti-fogging film that is difficult to apply.

In Examples 1 to 8, only water-absorbent polyol was used as the polyol component, and aliphatic polyester diol, short-chain polyol, acrylic polyol, etc., which are polyol components other than the water-absorbent polyol used in the conventional technology and Comparative Example 1, were used. Although not included, an antifogging coating with sufficient film hardness could be obtained.

The anti-fogging article of the present disclosure is used for construction such as mirrors and window glass for bathrooms and bathroom vanities, and for vehicles, ships, aircraft, etc., such as window glass or mirrors, specifically room mirrors, Can be used for door mirrors, etc. Other lenses such as eyeglasses and cameras, goggles, helmet shields, refrigerated showcases, freezer showcases, testing machines, openings and peepholes of precision equipment cases, road reflectors, displays of mobile communication devices such as mobile phones, etc. is also available.

Claims (17)

(A) a polyisocyanate having two or more isocyanate groups;
(B) a polyol comprising an oxyethylene unit as a repeating unit and having three or more hydroxy groups in the molecule;
(C) a solvent;
A coating agent for forming an antifogging film, comprising: The coating agent for forming an antifogging film according to claim 1, wherein the polyol (B) is a branched polyol. The coating agent for forming an antifogging film according to claim 1, wherein the polyol (B) is a cyclic polyol. 4. The coating agent for forming an antifogging film according to any one of claims 1 to 3, further comprising (D) a water repellent agent or (E) a hydrophilic agent. n _{( NCO) /n (OH), which is the ratio of the number n (NCO)} of isocyanate groups in the urethane-forming component to the number n _{(OH) of} hydroxyl groups in the urethane-forming component, is 1.0 to 3.0; The coating agent for forming an antifogging film according to any one of claims 1 to 4. The coating agent for forming an antifogging film according to any one of claims 1 to 5, wherein the content of the polyisocyanate (A) is 25 to 75% by mass with respect to 100% by mass of the urethane-forming component. . The coating agent for forming an antifogging film according to any one of claims 1 to 6, wherein the content of the polyol (B) is 25 to 75% by mass with respect to 100% by mass of the urethane-forming component. The antifogging coating according to claim 4, wherein the content of the water repellent agent (D) or hydrophilic agent (E) is 0.001 to 10.0% by mass with respect to 100% by mass of the urethane-forming component. Forming coating. A method for producing an antifogging article having a substrate and an antifogging coating, comprising:
A step (1) of applying the coating agent for forming an antifogging film according to any one of claims 1 to 8 to the surface of a substrate to form a coating film;
Step (2) of evaporating the solvent (C) from the coating film and curing the coating film to form an antifogging coating;
A method for manufacturing an anti-fogging article. 10. The method for producing an antifogging article according to claim 9, wherein said substrate is a glass substrate. The method for producing an antifogging article according to claim 10, wherein the surface of the glass substrate is coated with a silane coupling agent. The antifogging according to any one of claims 9 to 11, wherein in the step (2), the isocyanate groups of the polyisocyanate (A) react with the hydroxy groups of the polyol (B) to form polyurethane. method of manufacturing a sexual product. The method for producing an antifogging article according to any one of claims 9 to 12, wherein in the step (2), the coating film is heated at 80 to 170°C. An antifogging article having a substrate and an antifogging coating,
The antifogging coating is a coating containing a polyurethane resin, which is a cured product of the coating agent for forming an antifogging coating according to any one of claims 1 to 8,
The film thickness of the antifogging coating is 5 μm to 50 μm,
Anti-fogging article. 15. The antifogging article according to claim 14, wherein said substrate is a glass substrate. 16. The antifogging article according to claim 15, wherein the surface of said glass substrate is coated with a silane coupling agent. Water is dropped on the surface of the antifogging coating placed horizontally, dried at 60° C. for 1 hour, and then water scale is removed. Item 17. The antifogging article according to any one of items 14 to 16.