JP2021070759A - Anti-fogging coating agent - Google Patents

Abstract

To provide an anti-fogging coating agent that has an excellent anti-fogging property and can hold the same for a long term.SOLUTION: An anti-fogging coating agent contains a copolymer (A) including a vinyl monomer having a carboxyl group (a1), a dialkyl(meth)acrylamide (where alkyls independently have C1-4 carbon atoms) (a2), and an alkyl(meth)acrylate (where an alkyl has C1-12 carbon atoms) (a3) as constituent monomers, a compound having a sulfonic acid group and a carboxyl group and/or a hydroxy group (B), a hydroxide of alkali metal and/or alkaline earth metal (C), and an aqueous medium (F).SELECTED DRAWING: None

Description

The present invention relates to an antifogging coating agent.

The reason why the base material such as glass or plastic becomes cloudy is that when the surface temperature drops below the dew point, the moisture in the air adheres as fine water droplets and the light is diffusely reflected on the base material surface. Therefore, fogging can be prevented by preventing the formation of water droplets on the surface of the base material.
Conventionally, as a method for imparting antifogging property, a method of coating the surface with a mixture of a plurality of surfactants (Patent Document 1) is known.

Japanese Unexamined Patent Publication No. 2003-201355

However, in Patent Document 1, the antifogging effect is short, and the antifogging property is not sufficiently satisfactory. An object of the present invention is to provide an anti-fog coating agent having excellent anti-fog properties and its durability.

The present inventors have arrived at the present invention as a result of diligent studies to solve the above problems. That is, in the present invention, a vinyl monomer (a1) having a carboxyl group, a dialkyl (alkyl has 1 to 4 carbon atoms independently) (meth) acrylamide (a2), and an alkyl (alkyl having 1 to 12 carbon atoms) ( Meta) Copolymer containing acrylate (a3) as a constituent monomer, compound (B) having a sulfonic acid group and a carboxyl group and / or a hydroxyl group, alkali metal and / or alkaline earth metal water. An antifogging coating agent (X) containing an oxide (C) and an aqueous medium (F).

The antifogging coating agent (X) of the present invention has the following effects.
(1) Excellent anti-fog property and its durability.
(2) Excellent moisture resistance of the coating film.
(3) Excellent adhesion to base materials (particularly polycarbonate and polymethyl methacrylate).

<Vinyl monomer having a carboxyl group (a1)>
The vinyl monomer (a1) having a carboxyl group in the present invention is an unsaturated monocarboxylic acid [(meth) acrylic acid (acrylic acid and / or meta) having 3 to 20 carbon atoms [hereinafter, may be abbreviated as C]. It means acrylic acid. The same applies hereinafter.), Crotonic acid, cinnamic acid, vinyl benzoic acid, alkenoic acid [C4 to 20 (preferably C4 to 13), for example, vinyl acetic acid, 3-methyl-3-butenoic acid, 3-. Penthenic acid, 4- and 5-hexenoic acid], monoalkyl (C1-8) esters of unsaturated dicarboxylic acids [C4-16, eg, maleic acid monoalkyl esters, fumaric acid monoalkyl esters, citraconic acid monoalkyl esters], Unsaturated dicarboxylic acid monoesters [C5-20, eg, ethylcarbitol monoester of maleic acid, ethylcarbitol monoester of fumaric acid, glycol monoester of itaconic acid], etc.], C4-20 (preferably C4-16). Unsaturated dicarboxylic acids [maleic acid, fumaric acid, citraconic acid, itaconic acid, etc.] and the like can be mentioned.

Of the above (a1), (meth) acrylic acid is preferable, and acrylic acid is more preferable, from the viewpoint of the curing rate of the antifogging coating agent (X).

<Dialkyl (alkyl each has 1 to 3 carbon atoms independently) (meth) acrylamide (a2)>
Examples of the dialkyl (alkyls independently have 1 to 3 carbon atoms) (meth) acrylamide (a2) in the present invention include dimethyl (meth) acrylamide, diethyl (meth) acrylamide, diisopropyl (meth) acrylamide, and N-ethyl-. Examples include N-methyl (meth) acrylamide.

Of the above (a2), dimethyl (meth) acrylamide is preferable from the viewpoint of adhesion and coating film strength.

<Alkyl (alkyl carbon number 1-12) (meth) acrylate (a3)>
Examples of the alkyl (alkyl having 1 to 12 carbon atoms) (meth) acrylate (a3) include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and 2-. Examples thereof include ethylhexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, and dodecyl (meth) acrylate.
Of the above (a3), alkyl (1 to 4 carbon atoms) (meth) acrylate is preferable, and methyl (meth) acrylate is more preferable, from the viewpoint of the strength of the coating film.

<Other monomers (a4)>
Examples of the monomer (a4) other than the above (a1), (a2) and (a3) include N-alkyl (C1-5) aminoalkyl (C1-5) (meth) acrylamide and hydroxyalkyl (a4). Examples thereof include C1-5) (meth) acrylate, vinylalkyl (C1-20) ether, (meth) acrylonitrile, ethylene, propylene, vinyl acetate and vinyl propionate.

<Copolymer (A)>
The copolymer (A) in the present invention includes the vinyl monomer (a1) having a carboxyl group, dialkyl (alkyl each independently has 1 to 4 carbon atoms) (meth) acrylamide (a2), and alkyl (alkyl carbon). Numbers 1 to 12) (meth) acrylate (a3) is contained as a constituent monomer.
Further, (A) may contain other monomers (a4) other than the above-mentioned (a1), (a2), and (a3) as constituent monomers.

Based on the total weight of (a1) to (a3) constituting the copolymer (A), preferably (a1) is 5 to 20% by weight, (a2) is 15 to 80% by weight, and (a3) is. It is 5 to 65% by weight.
Further, based on the total weight of the above (a1) to (a3), (a4) is preferably 10% by weight or less, more preferably 1 to 5% by weight.

Based on the weight of (A), from the viewpoint of antifogging property and moisture resistance, the carboxyl group of (A) is preferably 0.4 to 3.0 mol / kg, more preferably 1.0 to 2.5. Mol / kg.

The copolymer (A) can be produced by the above-mentioned (a1) to (a3), and if necessary, (a4) by a known solution polymerization method (preferably in the presence of a radical polymerization initiator (f)). The solution polymerization method is preferable from the viewpoint of productivity. When the aqueous solvent described later is used, it may be desolved after polymerization or it may be used as it is without desolving. When an aqueous solvent is used, a dehydrating agent may be used in combination.
The (A) is obtained, for example, as a solution of (A), and the content (% by weight) of (A) in the solution is the productivity and handling during the production of the antifogging coating agent (X) in the subsequent step. From the viewpoint of sex, it is preferably 5 to 80%, more preferably 10 to 70%, and particularly preferably 20 to 60%.

The polymerization temperature is preferably 0 to 200 ° C. from the viewpoint of productivity and molecular weight control of (A).
The polymerization time is preferably 1 to 10 hours from the viewpoint of reducing the residual monomer content in the product and productivity.
The end point of the polymerization reaction can be confirmed by the amount of residual monomer. The amount of residual monomer is preferably 5% or less, more preferably 3% or less, from the viewpoint of the strength of the coating film. The amount of residual monomer can be measured by a gas chromatography method.

Weight average molecular weight of (A) [hereinafter abbreviated as Mw. The measurement is performed by the gel permeation chromatography (GPC) method described later. ] Is preferably 5,000 to 200,000, more preferably 10,000 to 150,000, and particularly preferably 15,000 to 100, from the viewpoints of antifogging property, durability, coating film strength, and productivity. It is 000.
The GPC measurement conditions of Mw in the present invention and the number average molecular weight described later (hereinafter abbreviated as Mn. The measurement is performed by the GPC method described later) are as follows.
<GPC measurement conditions>
[1] Equipment: Gel permeation chromatography
"HLC-8120GPC", manufactured by Tosoh Corporation.
[2] Column: "TSKgel G6000PWxl", "TSKgel"
"G3000PWxl" [both manufactured by Tosoh Corporation] are connected in series.
[3] Eluent: Methanol / water = 30/70 (volume ratio) in which 0.5% by weight of sodium acetate is dissolved.
[4] Reference substance: Polyethylene glycol (hereinafter abbreviated as PEG)
[5] Injection conditions: sample concentration 0.25%, column temperature 40 ° C.

<Compound (B) having a sulfonic acid group and a carboxyl group and / or a hydroxyl group>
Examples of the compound (B) having a sulfonic acid group and a carboxyl group and / or a hydroxyl group in the present invention include compounds represented by the following general formulas (1) and (2).

HO- (A ¹ O) _m -CO-Z-CO- (A ² O) _n- OH (1)

[In formula (1), m and n are independently integers of 0 to 5 (preferably 0 to 1, more preferably 0); A ¹ and A ² each independently have 2 to 3 carbon atoms (preferably carbon atoms). The alkylene group of Eq. 2); (A ¹ O) and (A ² O) may be the same or different, respectively, and Z excludes two carboxyl groups from the dicarboxylic acid (B0) having a sulfonic acid group. Indicates the residue. ]

R ^1- (A ¹ O) _m -CO-Z-CO- (A ² O) _n- OH (2)

[In the formula (2), R ¹ is a hydrocarbyl group having 1 to 13 carbon atoms (for example, alkyl, alkenyl, cycloalkyl, aralkyl and aryl) and an alkoxy group having 1 to 13 carbon atoms (for example, methoxy group and ethoxy group). And dodecyloxy); m and n are independently integers of 0 to 5 (preferably 0 to 1, more preferably 0); A ¹ and A ² are independently 2 to 3 carbon atoms (preferably 2 carbon atoms). ) Alkylene group; (A ¹ O) and (A ² O) may be the same or different, respectively, and Z is the residue obtained by removing two carboxyl groups from the dicarboxylic acid (B0) having a sulfonic acid group. Indicates a group. ]

Examples of the dicarboxylic acid (B0) having a sulfonic acid group include aromatic dicarboxylic acid (B01), sulfoaliphatic dicarboxylic acid (B02), and substituted sulfosuccinic acid (B03).
Examples of the aromatic dicarboxylic acid (B01) include sulfobenzenedicarboxylic acid (5-sulfo-ortho-, iso- or terephthalic acid, etc.), sulfonaphthalenedicarboxylic acid and the like.
Examples of the sulfoaliphatic dicarboxylic acid (B02) include sulfoalkane or sulfoalkendicarboxylic acid (for example, sulfosuccinic acid, sulfoglutaric acid, sulfoadipic acid, sulfopimelic acid, sulfosveric acid, sulfoazeline acid, sulfosevacinic acid and sulfomaleic acid) Can be mentioned.
Examples of the substituted sulfosuccinic acid (B03) include compounds represented by the following general formula (3).

HOOC-CH-CH-COOH (3)
｜ ｜
R ¹ SO ₃ H

[In formula (3), R ¹ is a hydrocarbyl group having 1 to 13 carbon atoms (for example, alkyl, alkenyl, cycloalkyl, aralkyl and aryl), an alkoxy group (for example, methoxy group and ethoxy group), a hydroxyl group and a cyano group. Represents a group, aldehyde group, nitro group or halogen atom (eg chlorine and bromine). ]

Of the above (B0), (B01) is preferable, sulfobenzenedicarboxylic acid is more preferable, and 5-sulfo-isophthalic acid is particularly preferable.

<Hydroxides of alkali metals and / or alkaline earth metals (C)>
Examples of the alkali metal and / or alkaline earth metal hydroxide (C) in the present invention include alkali metal hydroxide (C1) and alkaline earth metal hydroxide (C2). Examples of the (C) include lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide and the like.
Of these (C), sodium hydroxide, potassium hydroxide, magnesium hydroxide and calcium hydroxide are preferable from the viewpoint of antifogging property and industry, and sodium hydroxide and potassium hydroxide are more preferable. .. These may be used alone or in combination of two or more.

<Aqueous medium (F)>
Examples of the aqueous medium in the present invention include water and / or an aqueous solvent (solubility in 100 g of water is 10 g or more, 25 ° C.), water, ketone [methyl ethyl ketone (hereinafter abbreviated as MEK), etc.], alcohol [methanol, isopropanol, etc.]. And so on.
Of the aqueous medium (F), water is preferably 50% by weight or more, and more preferably 80% by weight or more from the viewpoint of productivity.

<Anti-fog coating agent (X)>
The antifogging coating agent (X) of the present invention is the above-mentioned copolymer (A), compound (B) having a sulfonic acid group and a carboxyl group and / or a hydroxyl group, alkali metal and / or alkaline earth metal water. It contains an oxide (C) and an aqueous medium (F).

The weight ratio [(A) / (B)] of the copolymer (A) to the compound (B) having a sulfonic acid group and a carboxyl group and / or a hydroxyl group is preferably 75/25 to 97/3. Is.

Further, in (X), the molar ratio (γ1) calculated by the following formula is preferably 0.05 to 0.5, more preferably 0.1 to 0.4.

Molar ratio (γ1) =
Valuation of (C) x number of moles of (C) / total number of moles of carboxyl group and sulfonic acid group of (A) and (B)

The total content of (A), (B) and (C) in the antifogging coating agent (X) of the present invention is preferably 2 to 80% by weight, more preferably 2 to 80% by weight, from the viewpoint of productivity and coatability. It is 3 to 70% by weight, particularly preferably 4 to 60% by weight.

<Crosslinking agent (D)>
The antifogging coating agent (X) of the present invention may contain a cross-linking agent (D) other than the above-mentioned (A) and (B), if necessary, in order to improve the physical characteristics of the coating film. When the cross-linking agent (D) contains a cross-linking agent (D) in which the total of the functional group reactive with the carboxyl group and the functional group reactive with the hydroxyl group is at least two, the cross-linking agent (D) and (A) and ( The weight [(D) / {(A) + (B)}] of (D) based on the total weight with B) is preferably 1/99 to 50/50, more preferably 3/97 to 40 /. 60, particularly preferably 5/95 to 30/70.

Examples of the cross-linking agent (D) include aminoalcohol (D1), polyamine (D2), polyol (D3), polyepoxide (D4), polyisocyanate (D5), polycarbodiimide (D6), and polyoxazoline (D7). It is preferable that (D) does not have a carboxyl group and / or a sulfonic acid group.

Examples of the amino alcohol (D1) include hydroxylamine of C2 to 20, an alkylene oxide (hereinafter abbreviated as AO) adduct of amine, and a mixture thereof.

Hydroxylamines include C2-20, for example, one having one hydroxyl group [for example, one having an amino group [for example, monoethanolamine, isopropanolamine], one having an amino group and an imino group [for example, 2- (2-aminoethylamino). ) Ethanol], etc.], those having two hydroxyl groups [those having an imino group (for example, diisopropanolamine, diethanolamine, etc.), etc.] can be mentioned.

AO adducts of amines include those with C3 or more and Mn 3,000 or less, such as aliphatic amines [C1-10, such as methylamine, ethylamine, n- and i-propylamine, ethylenediamine, diethylenetriamine], aromatic amines [ AO addition of C6-12, such as aniline, toluidine, xylylene diamine], alicyclic-containing amines [C4-10, such as cyclopentylamine, cyclohexylamine], heterocyclic amines [C4-10, such as piperazine] and the hydroxylamine. Things can be mentioned. The number of moles added with AO is preferably 1 to 20 moles. Many of these amine AO adducts have an imino group.

AOs include C2-12 or higher (preferably C2-4) AOs such as ethylene oxide, 1,2-propylene oxide, 1,2-, 2,3- and 1,3-butylene oxide, tetrahydrofuran. And 3-methyl-tetrahydrofuran), 1,3-propylene oxide, isobutylene oxide, α-olefin oxides of C5-12, substituted AOs such as styrene oxide, and combinations of two or more of these (random addition and / or block addition). ) Is included.

Of these (D1), C2-20 hydroxylamine is preferable from the viewpoint of the stability of the curable and antifogging coating agent (X), and monoethanolamine, diethanolamine, and isopropanolamine are particularly preferable. Diethanolamine is preferred. These may be used alone or in combination of two or more.

Examples of the polyamine (D2) include alkylenediamines, polyalkylene polyamines, alicyclic polyamines, heterocyclic polyamines, and mixtures thereof.

The alkylenediamine is an alkylenediamine containing an alkylene group of about C1 to 10, and examples thereof include ethylenediamine, propylenediamine, and hexamethylenediamine.

Examples of the polyalkylene polyamine include polyethyleneimine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, iminobispropylamine, 3-azahexane-1,6-diamine and the like.

Examples of the alicyclic polyamine include isophorone diamine, bis (aminomethyl) cyclohexane, 4,7-diazadecan-1,10-diamine and the like.

The heterocyclic polyamine contains, for example, a heterocycle which is an alicyclic hydrocarbon group containing at least one heteroatom such as a nitrogen atom, an oxygen atom and a sulfur atom in the molecule, and also contains a primary amino group and a primary amino group. / Or an amine having at least two secondary amino groups. For example, heterocyclic amines containing heterocyclic diamines [eg, piperazine, homopiperazin, N-methylpiperazin, N-ethylpiperazin, N-propylpiperazin, N-acetylpiperazin and 1- (chlorophenyl) piperazine, etc.], aminoalkyl. [For example, N-aminoethyl piperidine, N-aminopropyl piperidine, N-aminoethyl piperazine, N-aminopropyl piperazine, N-aminoethyl morpholine, N-aminopropyl morpholine, N-aminopropyl-2-pipecholine, N-amino Propyl-4-pipecholine and 1,4-bis (aminopropyl) piperazine, etc.] and the like.

Of these (D2), alkylenediamine and polyalkylene polyamine are preferable from the viewpoint of curability and stability of the antifogging coating agent (X), ethylenediamine and diethylenetriamine are more preferable, and ethylenediamine is particularly preferable. is there. These may be used alone or in combination of two or more.

Examples of the polyol (D3) include polyhydric alcohols, polyhydric phenols, and mixtures thereof.

Examples of the polyhydric alcohol include C2-18 dihydric alcohols [ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4- and 1,3-butanediol, 1,6-hexanediol and neopentyl glycol. Etc.], C3-18 (preferably 3-12) tri-5-valent polyhydric alcohols [alcan polyols and their intra- and intermolecular dehydrations such as glycerin, trimethylolpropane, pentaerythritol, sorbitan, diglycerin. Sugars and derivatives thereof, such as a-methylglucoside, xylitol, glucose, fructose; etc.], and 6-10 or higher multihydric alcohols of C5-18 (preferably 5-12) [6-10 valences]. , And intramolecular or intermolecular dehydrations of polyhydric alcan polyols, such as dipentaerythritol; saccharides and derivatives thereof, such as sorbitol, mannitol, sucrose; etc.] and the like.

Examples of polyhydric phenols include divalent phenols [monocyclic polyhydric phenols (hydroquinone, etc.), bisphenols (bisphenol A, bisphenol F, etc.), etc.], and trivalent to pentavalent polyhydric phenols [monocyclic polyhydric phenols (pyrogalol, etc.). Fluoroglucin, etc.), formalin low condensate of phenol compound (3 to 5 valence) (number average molecular weight 1000 or less) (novolac resin, intermediate of resole), etc.], 6 to 10 valent or higher polyhydric phenol [phenol compound] Formalin low condensate (hexavalent or more) (number average molecular weight 1000 or less) (novolac resin, intermediate of resole), etc.], condensate of phenol and alkanolamine (Mannich polyol), and the like.

Of these (D3), polyhydric alcohol is preferable from the viewpoint of the stability of the curable and antifogging coating agent (X) and the transparency of the cured product, and glycerin and pentaerythritol are particularly preferable. Is glycerin. These may be used alone or in combination of two or more.

Examples of the polyepoxide (D4) include glycidyl ether of a polyhydric alcohol, glycidyl ester of a polybasic acid, and a mixture thereof.

Polyhydric alcohol glycidyl ethers include polyethylene glycol diglycidyl ether, bisphenol A type diglycidyl ether, bisphenol F type diglycidyl ether, glycerin triglycidyl ether, trimethylolpropantriglycidyl ether, pentaerythritol tetraglycidyl ether, and sorbitol hexaglycidyl ether. And so on.

Examples of the glycidyl ester of a polybasic acid include a phthalic acid diglycidyl ester.

Of these (D4), the polyhydric alcohol glycidyl ether is preferable from the viewpoint of the stability of the curable and antifogging coating agent (X) and the transparency of the cured product, and polyethylene glycol diglycidyl is more preferable. Ethers, glycerin triglycidyl ethers, sorbitol hexaglycidyl ethers, particularly preferred are glycerin triglycidyl ethers. These may be used alone or in combination of two or more.

The polyisocyanate (D5) is a polyisocyanate or a blocked polyisocyanate compound in which the isocyanate group of the polyisocyanate is blocked with an active hydrogen-containing compound.

Examples of the polyisocyanate constituting (D5) include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 1,12-dodecamethylene diisocyanate, cyclohexane-1,3- or 1,4-. Diisocyanate, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (also known as isophorone diisocyanate; IPDI), dicyclohexylmethane-4,4'-diisocyanate (also known as hydrogenated MDI), 2- or 4- Isocyanatocyclohexyl-2'-isocyanatocyclohexylmethane, 1,3- or 1,4-bis- (isocyanatomethyl) -cyclohexane, bis- (4-isocyanato-3-methylcyclohexyl) methane, 1,3- or 1,4-α, α, α', α'-tetramethylxylylene diisocyanate, 2,4- or 2,6-diisocyanatotoluene, 2,2'-, 2,4'-or 4,4' -Diisocyanatodiphenylmethane (MDI), 1,5-naphthalenediocyanate, p- or m-phenylenediocyanate, xylene diisocyanate, diphenyl-4,4'-diisocyanate and the like can be mentioned. Only one type of polyisocyanate may be used alone, or two or more types may be used in combination.

Of these polyisocyanates, 1,4-tetramethylene diisocyanate and 1,6-hexamethylene diisocyanate (1,4-tetramethylene diisocyanate) and 1,6-hexamethylene diisocyanate (1,4-tetramethylene diisocyanate) and 1,6-hexamethylene diisocyanate (1,4-tetramethylene diisocyanate) and 1,6-hexamethylene diisocyanate (1,4-tetramethylene diisocyanate) and 1,6-hexamethylene diisocyanate ( HDI), 1,12-dodecamethylene diisocyanate, more preferably 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI). These may be used alone or in combination of two or more.

The active hydrogen-containing compound (blocking agent) used in (D5) is not particularly limited, and is: -OH group (alcohols, phenols, etc.), = N-OH group (oximes, etc.), = NH group. Examples thereof include compounds having (amines, amides, imides, lactams, etc.), compounds having a −CH ₂ − group (active oxime group), and azoles.
For example, phenol, cresol, xylenol, ε-caprolactam, δ-valerolactam, γ-butyrolactam, methanol, ethanol, n-, i-, or t-butyl alcohol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol mono. Ethyl ether, propylene glycol monomethyl ether, benzyl alcohol, formamide oxime, acetaldoxime, acetoxime, methyl ethyl ketooxime, diacetyl monooxime, benzophenone oxime, cyclohexane oxime, dimethyl malonate, ethyl acetoacetate, acetylacetone, pyrazole and the like.

Among these blocking agents, methyl ethyl ketooxime and dimethyl malonate are preferable from the viewpoint of the dissociation temperature of isocyanate and the transparency of the cured product. These may be used alone or in combination of two or more.

Examples of the carbodiimide (D6) include monocarbodiimide compounds and polycarbodiimide compounds. For example, dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropylcarbodiimide, diphenylcarbodiimide, di-t-butylcarbodiimide, di-β-naphthylcarbodiimide and the like can be mentioned.

Of these (D6), a polycarbodiimide compound is preferable from the viewpoint of the stability of the curable and antifogging coating agent (X) and the transparency of the cured product. Carbodilite V-02 and Carbodilite E-01. (D6) may be used alone or in combination of two or more.

Examples of polyoxazoline (D7) include 2,2'-bis- (2-oxazoline), 2,2'-methylene-bis- (2-oxazoline), and 2,2'-ethylene-bis- (2-oxazoline). , 2,2'-Trimethylene-bis- (2-oxazoline), 2,2'-tetramethylene-bis- (2-oxazoline), 2,2'-hexamethylene-bis- (2-oxazoline), 2, 2'-octamethylene-bis- (2-oxazoline), 2,2'-ethylene-bis- (4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis- (2- Oxazoline), 2,2'-m-phenylene-bis- (4,4'-dimethyl-2-oxazoline), bis- (2-oxazolinercyclohexane) sulfide and bis- (2-oxazolinylnorbornan) sulfide Examples thereof include an aqueous resin obtained by polymerizing an unsaturated oxazoline such as 2-vinyl-2-oxazoline and 2-isopropenyl-2-oxazoline with another unsaturated compound.

Of these (D7), a polymer having an acrylic main chain is preferable from the viewpoint of the stability of the curable and antifogging coating agent (X) and the transparency of the cured product, and for example, it is commercially available. Examples of the product include Epocross WS-500 and Epocross WS-700 manufactured by Nippon Shokubai Co., Ltd. (B7) may be used alone or in combination of two or more.

Of the above (D), (D4), (D6), and (D7) are preferable from the viewpoints of antifogging property, adhesion, curability, stability of the antifogging coating agent (X), and transparency of the cured product. ), More preferably (D6).

The antifogging coating agent (X) of the present invention is a curing accelerator, an adhesion improver, a viscosity modifier, an antioxidant, an ultraviolet absorber, a stabilizer, and a plasticizer, if necessary, as long as the effects of the present invention are not impaired. One or more other additives selected from the group consisting of agents, waxes, pigments or dyes, antistatic agents, antibacterial agents, antifungal agents, fragrances, flame retardants, dispersants, film-forming aids and wetting agents. Agent (E) may be used in combination.

The total amount of the additive (E) used is, for example, 50% or less based on the total weight of (A) and (B), preferably 0 from the viewpoint of the addition effect of each additive, the strength of the coating film, and the adhesion. .5 to 20%.
The amount of each additive used based on the total weight of (A) and (B) is, for example, 10 for each of the curing accelerator, the antioxidant, the ultraviolet absorber, the stabilizer, the antibacterial agent, the mold retardant and the fragrance. % Or less, preferably 0.5 to 5% from the same viewpoint as above; plasticizers, waxes, pigments or dyes, antistatic agents, flame retardants, dispersants, film-forming aids and wetting agents, for example, 10% each. Hereinafter, it is preferably 1 to 5% from the same viewpoint as above.

Examples of the method for producing the antifogging coating agent (X) of the present invention include (co) polymer (A), compound (B), alkali metal and / or alkali earth metal hydroxide (C), and the like. It is also obtained by mixing an aqueous medium (F), and if necessary, a cross-linking agent (D) and an additive (E). The mixing time is, for example, 1 minute to 3 hours, and the mixed state of the antifogging coating agent (X) can be visually confirmed.
The above (A), (B), (C), (F), and if necessary, (D) and (E) may be mixed in the form of a solution of the aqueous medium (F), respectively.

Further, at the time of producing (A), a monomer (a1n) in which a part or all of (a1) is neutralized by (C) may be used.
Further, when (B) has a carboxyl group and a sulfonic acid group, (Bn) in which a part or all of (B) is neutralized by (C) may be used.
In that case, for example, sodium acrylate as a monomer is prepared by charging acrylic acid and sodium hydroxide in the present invention, and for example, sodium 5-sulfo-terephthalate is 5-sulfo-terephthalate. It is calculated as if an acid and sodium hydroxide were charged in the constitution of the present invention.

<Anti-fog coating film, anti-fog article>
The anti-fog coating agent (X) of the present invention is an anti-fog article formed by coating and heat-curing a base material (polycarbonate, polymethyl methacrylate, glass, etc.) or an anti-fog film (X) itself. It is preferably used as a cloudy coating film.
Examples of the coating method include dip coating, roll coating, spin coating, spray coating and the like, but the coating method is not particularly limited thereto.
The heat curing temperature is preferably 50 ° C. to 250 ° C., more preferably 80 ° C. to 200 ° C. from the viewpoint of productivity and transparency of the coating film.

<Anti-fog coating film, anti-fog article>
The anti-fog coating agent (X) of the present invention is suitable as an anti-fog article obtained by coating, baking and heat-curing a plate glass, a resin plate, or the like, or an anti-fog coating film obtained by forming (X) itself into a film. Used for.
Examples of the coating method include dip coating, roll coating, spin coating, spray coating and the like, but the coating method is not particularly limited thereto.
The heat curing temperature at the time of baking is preferably 50 ° C. to 250 ° C., more preferably 80 ° C. to 200 ° C. from the viewpoint of productivity and transparency of the coating film.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. In the following, parts and% indicate parts by weight and% by weight, respectively.

<Manufacturing example 1>
200 parts [solvent] of isopropanol was charged into the autoclave, and nitrogen was aerated under stirring to replace the nitrogen in the autoclave (gas phase oxygen concentration of 500 ppm or less). A solution in which 0.22 parts of 2,2'-azobis (2-methylbutyronitrile) [radical polymerization initiator (f-1)] was dissolved in 20 parts of isopropanol after raising the temperature to 82 ° C. while blowing nitrogen. And a mixed solution of 10 parts of methacrylic acid (a1-2), 30 parts of dimethylacrylamide (a2-1), 55 parts of butylmethacrylate (a3-2) and 5 parts of 2-hydroxyethyl methacrylate (a4-1). Was simultaneously added dropwise over 3 hours, and further stirred at 82 ° C. for 2 hours to carry out a polymerization reaction.
Next, 140 parts of isopropanol [solvent] was removed, and then the mixture was cooled to 30 ° C. Further, isopropanol [solvent] was added to adjust the concentration to obtain a solution (40% by weight) of the copolymer (A-1).

<Production Example 2, Comparative Production Example 1>
In Production Example 1, a solution (40% by weight) of each copolymer (A) was obtained in the same manner as in Production Example 1 except that the raw materials (parts) used in Table 1 were followed.

<Manufacturing example 3>
In Production Example 1, the polymerization reaction was carried out according to the raw materials (parts) used in Table 1.
Next, the isopropanol [solvent] was removed, and water was added so that the non-volatile component became 40% to obtain an aqueous solution (40% by weight) of the copolymer (A-3). The results are shown in Table 1.

<Examples 1 to 5, Comparative Example 1>
According to the compounding composition (part) shown in Table 2, each antifogging coating agent (X) was prepared by charging and mixing in a container.
Next, on a polycarbonate resin (PC) plate having a thickness of 5 mm and 100 mm square, each of the obtained antifogging coating agents (X) was spray-coated so that the thickness of the coating film after curing was 5 μm. After being applied uniformly, heat treatment was performed for 30 minutes in a circulation dryer at 120 ° C. to obtain each antifogging article having an antifogging coating film.
Each of the obtained antifogging articles was evaluated according to the evaluation method described later. The results are shown in Table 2.

(C), cross-linking agent (D), and (F) used in Examples and Comparative Examples are as follows.
(C-1): Sodium hydroxide (C-2): Potassium hydroxide (D-1) solution: Polycarbodiimide [Product name "Carbodilite V-04", manufactured by Nisshinbo Holdings, Inc., active ingredient 40% by weight
Carbodiimide equivalent: 335 g / eq]
(D-2): Polyepoxide [Product name "Denacol EX-313", manufactured by Nagase ChemteX Corporation,
Epoxy equivalent: 141 g / eq, glycerin triglycidyl ether]
(F-1): Ion-exchanged water (F-2): Methanol

<1> Anti-fog (PC board)
The coating film surface of the antifogging article held for 1 hour in a constant temperature and humidity chamber maintained at 20 ° C. and a relative humidity of 50% was held 6 cm above a hot water bath at 80 ° C., and the time until fogging was observed was measured. did. The test results were evaluated according to the following criteria.
<Evaluation criteria>
Time until cloudiness ◎: 70 seconds or more ○: 35 seconds or more, less than 70 seconds Δ: 10 seconds or more, less than 35 seconds ×: less than 10 seconds

<2> Heat resistance (evaluation of anti-fog durability) (PC board)
The coating film of the antifogging article was kept in a constant temperature bath kept at 110 ° C. for 15 days, and the change in appearance and the rate of decrease in the antifogging property were evaluated according to the following criteria.
<Evaluation criteria>
⊚: No change in appearance, reduction rate of anti-fog property is less than 20% ○: No change in appearance, reduction rate of anti-fog property is 20% or more, less than 30% Δ: Change in appearance or anti-fog property Reduction rate of 30% or more ×: There is a change in appearance, and the reduction rate of the anti-fog test is 30% or more.

(Decrease rate of anti-fog property) =
[(T1)-(t2)] × 100 / (t1)

However, (t1): Antifogging property (time) of the coating film before the heat resistance test.
(T2): Anti-fog property (time) of the coating film after the heat resistance test

<3> Adhesion (evaluation of adhesion with PC)
The anti-fog coating surface was subjected to a grid test in accordance with JIS K5600-5-6, and evaluated according to the following criteria.
<Evaluation criteria>
⊚: No peeling of squares and no peeling at crosscut intersection ○: No peeling of squares and slight peeling at crosscut intersection Δ: 1 to 3 squares out of 100 squares ×: 100 There is peeling of 4 or more squares in the square

<4> Moisture resistance The anti-fog coating film is kept in a constant temperature and humidity chamber maintained at 20 ° C. and 60% relative humidity for 420 hours, and changes in the appearance of the coating film surface (discoloration, swelling, peeling, etc.) are confirmed. , Evaluated according to the following criteria.
<Evaluation criteria>
◎: No change in appearance ○: Very slight change in appearance △: Change in appearance ×: Significant change in appearance

From the results in Tables 1 and 2, it can be seen that the antifogging coating agent of the present invention is superior in antifogging property and its durability, moisture resistance of the coating film, and adhesion to the substrate as compared with the comparative ones.

Since the antifogging coating agent of the present invention is excellent in antifogging property and its durability, moisture resistance of the coating film, and adhesion to the base material, a polycarbonate plate, a glass plate, a wash basin, a bath mirror, etc. It is extremely useful because it can be widely and suitably used for various coating applications that require visibility.

Claims (7)

A vinyl monomer (a1) having a carboxyl group, a dialkyl (alkyl has 1 to 4 carbon atoms independently) (meth) acrylamide (a2), and an alkyl (alkyl having 1 to 12 carbon atoms) (meth) acrylate (a3). A copolymer (A) containing the above as a constituent monomer, a compound (B) having a sulfonic acid group and a carboxyl group and / or a hydroxyl group, an alkali metal and / or an alkali earth metal hydroxide (C), An antifogging coating agent (X) containing the aqueous medium (F) as well. Based on the total weight of (a1) to (a3) constituting the copolymer (A), (a1) is 5 to 20% by weight, (a2) is 15 to 80% by weight, and (a3) is 5 to 5%. The antifogging coating agent according to claim 1, which is 65% by weight. The antifogging coating agent according to claim 1 or 2, wherein the weight ratio [(A) / (B)] of the copolymer (A) to the compound (B) is 75/25 to 97/3. Further, it contains a cross-linking agent (D) in which a total of at least two functional groups having reactivity with a carboxyl group other than the above (A) and (B) and a functional group having reactivity with a hydroxyl group is at least two. The antifogging coating agent according to any one of claims 1 to 3. The cross-linking agent (D) is selected from the group consisting of aminoalcohol (D1), polyamine (D2), polyol (D3), polyepoxide (D4), polyisocyanate (D5), polycarbodiimide (D6) and polyoxazoline (D7). The antifogging coating agent according to claim 4, which is at least one kind. An anti-fog article obtained by applying the anti-fog coating agent (X) according to any one of claims 1 to 5 and heat-curing. An anti-fog coating film obtained by heat-curing the anti-fog coating agent (X) according to any one of claims 1 to 5.