JP2017105936A - Antifogging agent composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antifogging agent composition capable of forming an antifogging coated film having antifogging property required for a vehicle lighting tool under a condition at low temperature for short time and a coated article thereof.SOLUTION: There is provided an antifogging agent composition containing a (meth)acrylic copolymer (A), a basic compound (B), a surfactant (C) and a solvent (D), wherein the (meth)acrylic copolymer (A) is an acrylic copolymer by copolymerization of a (meth)acrylic derivative, (meth)acrylic acid ester having sulfonic acid and (meth)acrylic acid ester at specific amounts, the solvent (D) contains at least C2 to 3 monovalent alcohol (d) and 2-methyl-2-butanol (d2) and having percentage of alcohol with the melting point of 64 to 250°C of 96.5 wt.% or more, total percentage of d1 and d2 in the solvent (D) is over 95.5 wt.% and percentage of d1 is 76.5 to 96.0 wt.%.SELECTED DRAWING: None

Description

  The present invention relates to an antifogging agent composition and a coated article thereof.

  In vehicle lamps such as automobile headlamps, high-humidity air enters the lamp chamber, the lens is cooled by outside air, rain, or the like, and moisture may condense on the inner surface of the lens, resulting in cloudiness. As a result, the brightness of the vehicle light decreases and the aesthetic appearance of the lens surface may be impaired, which may cause discomfort to the user. In order to prevent such fogging of the inner surface of the lens, a method of coating an antifogging agent composition on the inner surface of the lens to form an antifogging coating film is known.

  The anti-fogging agent composition includes a monomer having an N-methylol group or an N-alkoxymethylol group (N-methylol ether group), a monomer having a sulfonic acid group, and a monomer having an alkyl group. An antifogging agent composition containing a copolymer formed from a monomer mixture is known (Patent Document 1).

JP 2011-140589 A

  In the antifogging agent composition described in Patent Document 1, in order to obtain an antifogging coating film having antifogging properties required for vehicle lamps in a curing time of about several tens of minutes, this antifogging agent composition It was necessary to heat cure at about 80 ° C. or higher.

  Usually, polycarbonate (PC) resin or polymethyl methacrylate (PMMA) resin is used for the lens used for a vehicle lamp from the viewpoint of high transparency and excellent impact resistance. Since the PC resin has a thermal deformation temperature of about 130 ° C., the PC resin will not be deformed under the 80 ° C. thermosetting temperature condition, but the PMMA resin has a molecular weight, an additive, etc. Because of this difference, the heat distortion temperature is about 65 to 90 ° C., and therefore, there is a problem that the heat distortion temperature is deformed depending on the type of PMMA resin used under the heat curing temperature condition of 80 ° C.

  In order to solve this problem, it is possible to cure at a temperature at which this deformation can be prevented without depending on the type of PMMA resin, for example, at a temperature of about 60 ° C. There is a need for an anti-fogging agent composition that can be cured within a degree.

  The present invention provides an antifogging agent composition and a coated article thereof capable of forming an antifogging coating film having antifogging properties required for a vehicle lamp under a low temperature and a short time condition as compared with a conventional antifogging agent composition. The purpose is to provide.

  As a result of intensive studies to solve the above problems, the present inventors have found that a monomer having an N-methylol group or an N-alkoxymethylol group (N-methylol ether group), a monomer having a sulfonic acid group And an anti-fogging agent composition containing a specific acrylic copolymer formed from a monomer mixture containing a monomer having an alkyl group, by using a mixture of specific solvents at low temperature and short time conditions The inventors have found that an antifogging coating film having antifogging properties required for a vehicle lamp can be formed.

That is, the present invention is an antifogging agent composition containing an acrylic copolymer (A), a basic compound (B), a surfactant (C), and a solvent (D),
The acrylic copolymer (A) is represented by the following general formula (1)
[In the general formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is a straight-chain or branched-chain alkyl group having 1 to 4 carbon hydrogen atom or a carbon. A monomer (a1) represented by
The following general formula (2)
[In the general formula (2), R ³ is a hydrogen atom or a methyl group, X is O or NH, and R ⁴ is a linear or branched alkylene group having 1 to ⁴ carbon atoms. And a monomer (a2) represented by the following general formula (3)
[In the general formula (3), R ⁵ is a hydrogen atom or a methyl group, R ⁶ is a straight-chain or branched-chain alkyl group having 1 to 4 carbon atoms. An acrylic copolymer formed from a monomer mixture containing a monomer (a3) represented by
In the monomer mixture, the proportion of monomer (a1) is more than 6% by weight, less than 13% by weight, the proportion of monomer (a2) is more than 11% by weight, less than 19% by weight, and monomer The total proportion of (a1) to (a3) is over 90% by weight,
The proportion of the basic compound (B) is more than 60 mol% and less than 95 mol% with respect to the sulfonic acid group of the monomer (a2),
The solvent (D) contains an alcohol having a boiling point of 64 ° C. or more and 250 ° C. or less, including at least a monohydric alcohol (d1) having 2 to 3 carbon atoms and 2-methyl-2-butanol (d2),
The ratio of the alcohol having a boiling point of 64 ° C. or more and 250 ° C. or less in the solvent (D) is 96.5% by weight or more,
The total proportion of (d1) and (d2) in the solvent (D) is more than 95.5% by weight;
It is related with the anti-fogging agent composition whose ratio of the said (d1) in the said solvent (D) is 76.5 weight% or more and 96.0 weight% or less.

The anti-fogging agent composition of the present invention further includes the following general formula (4) in addition to the monomer mixture.
[In the general formula (4), R ⁷ is a hydrogen atom or a methyl group, R ⁸ is a hydrogen atom or a linear alkyl group having 1 to 3 carbon atoms, and R ⁹ is a linear alkyl group having 1 to 3 carbon atoms. R ⁸ and R ⁹ may be the same or different. It is preferable that the monomer (a4) represented by this is included.

  In the antifogging agent composition of the present invention, the proportion of the alcohol (d3) having a boiling point other than (d1) and (d2) in the solvent (D) of 64 ° C. or higher and 250 ° C. or lower is 4.5% by weight. % Or less is preferable.

  The present invention relates to a coated article obtained by coating the object to be coated with the antifogging agent composition and heat-curing the antifogging agent composition.

  According to the antifogging agent composition of the present invention, for example, since the antifogging coating film obtained by thermosetting it at 60 ° C. for 40 minutes has antifogging properties required for vehicle lamps, As compared with the antifogging agent composition, it is possible to provide an antifogging agent composition and a coated article thereof that can form an antifogging coating film that exhibits antifogging properties by heat curing under low temperature and short time conditions.

  The antifogging agent composition of the present invention contains an acrylic copolymer (A), a basic compound (B), a surfactant (C), and a solvent (D).

<Acrylic copolymer (A)>
The acrylic copolymer (A) of the present invention comprises at least monomers (a1) to (a3) and is formed from a monomer mixture containing monomer (a4) as an optional component.

<Monomer (a1)>
The monomer (a1) of the present invention is a monomer having an N-methylol group or an N-methylol ether group represented by the following general formula (1), and is co-polymerized by a dehydration condensation reaction or a dealcoholization condensation reaction. It has a function of forming a crosslinked structure in the coalescence and imparting water resistance to the anti-fogging coating film.
[In the general formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is a straight-chain or branched-chain alkyl group having 1 to 4 carbon hydrogen atom or a carbon. ]

  In the monomer (a1), examples of the compound represented by the general formula (1) include N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N -Butoxymethyl (meth) acrylamide etc. are mentioned. As the monomer (a1), at least one type may be used, and two or more types may be used in combination.

<Monomer (a2)>
The monomer (a2) of the present invention is a monomer having a sulfonic acid group represented by the following general formula (2), a function as an acid catalyst, a function of increasing the hydrophilicity of an antifogging coating film, and The antifogging coating film has a function of imparting breath antifogging properties after a long-term water resistance test.
[In the general formula (2), R ³ is a hydrogen atom or a methyl group, X is O or NH, and R ⁴ is a linear or branched alkylene group having 1 to ⁴ carbon atoms. ]

  In the monomer (a2), examples of the compound represented by the general formula (2) include 2- (meth) acrylamido-2-methylpropanesulfonic acid, 2-((meth) acryloyloxy) ethanesulfonic acid, 3-((meth) acryloyloxy) -1-propanesulfonic acid and the like can be mentioned. As the monomer (a2), at least one type may be used, and two or more types may be used in combination.

<Monomer (a3)>
The monomer (a3) of the present invention is a monomer having an alkyl group represented by the following general formula (3), a function of increasing the hydrophobicity of the antifogging coating film, It has a function to improve the adhesion.
[In the general formula (3), R ⁵ is a hydrogen atom or a methyl group, R ⁶ is a straight-chain or branched-chain alkyl group having 1 to 4 carbon atoms. ]

  In the monomer (a3), the compound represented by the general formula (3) includes methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) ) Acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate and the like. As the monomer (a3), at least one type may be used, and two or more types may be used in combination.

<Monomer (a4)>
It is preferable that the monomer mixture forming the acrylic copolymer (A) further contains a (meth) acrylamide monomer (a4) represented by the following general formula (4). A monomer (a4) has a function which improves the hydrophilic property of an anti-fogging coating film.
[In the general formula (4), R ⁷ is a hydrogen atom or a methyl group, R ⁸ is a hydrogen atom or a linear alkyl group having 1 to 3 carbon atoms, and R ⁹ is a linear alkyl group having 1 to 3 carbon atoms. R ⁸ and R ⁹ may be the same or different. ]

  In the monomer (a4), the compound represented by the general formula (4) includes (meth) acrylamide, N-methylacrylamide, N, N-dimethyl (meth) acrylamide, and N-ethyl (meth) acrylamide. N, N-diethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide and the like. As the monomer (a4), at least one type may be used, and two or more types may be used in combination.

<Other monomers>
Examples of other monomers other than (a1) to (a4) that can form the acrylic copolymer (A) include known monomers other than (a1) to (a4), such as styrene and vinyl. Monomers having aromatic rings such as toluene and α-methylstyrene; (methoxy) polyethylene glycol mono (meth) acrylate, (methoxy) polypropylene glycol mono (meth) acrylate, (ethoxy) polyethylene glycol mono (meth) acrylate, ( Monomers having an alkoxyalkylene glycol group such as ethoxy) polypropylene glycol mono (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2- Hydroxyethyl (meth) ac Monomer having a hydroxyl group such as ε-caprolactone adduct of acrylate; monomer having a carboxyl group such as (meth) acrylic acid, crotonic acid, maleic acid, maleic acid half ester, and alkali metal salts and ammonium salts thereof A monomer having a nitrogen atom such as (meth) acryloylmorpholine, N-vinyl-2-pyrrolidone, 2-vinylpyridine and the like can be used.

  Below, the ratio of each monomer component in the monomer mixture which forms the acrylic copolymer (A) of this invention is demonstrated.

  The proportion of the monomer (a1) in the monomer mixture forming the acrylic copolymer (A) is more than 6% by weight and less than 13%. The proportion of the monomer (a1) in the monomer mixture forming the acrylic copolymer (A) is preferably 7% by weight or more from the viewpoint of improving the adhesion between the antifogging coating film and the substrate, and is 8% by weight. % Or more is more preferable. The proportion of the monomer (a1) in the monomer mixture forming the acrylic copolymer (A) is 12% by weight or less from the viewpoint of maintaining the transparency of the antifogging coating film after the long-term water resistance test. Preferably, 11 weight% or less is more preferable.

  The proportion of the monomer (a2) in the monomer mixture forming the acrylic copolymer (A) is more than 11% by weight and less than 19% by weight. The proportion of the monomer (a2) in the monomer mixture forming the acrylic copolymer (A) is 12% by weight from the viewpoint of imparting the antifogging property after the long-term water resistance test to the antifogging coating film. The above is preferable, and 14% by weight or more is more preferable. The proportion of the monomer (a2) in the monomer mixture that forms the acrylic copolymer (A) is such that the adhesion between the antifogging coating film and the substrate is increased, and antifogging after a long-term water resistance test. From the viewpoint of maintaining the transparency of the coating film, it is preferably 18% by weight or less, and more preferably 16% by weight or less.

  The proportion of the monomer (a3) in the monomer mixture forming the acrylic copolymer (A) is preferably 60% by weight or more from the viewpoint of enhancing the adhesion between the antifogging coating film and the substrate, 65 weight% or more is more preferable. The proportion of the monomer (a3) in the monomer mixture forming the acrylic copolymer (A) is preferably 80% by weight or less, and 75% by weight or less from the viewpoint of improving the antifogging property of the antifogging coating film. Is more preferable.

  The total ratio of the monomers (a1) to (a3) in the monomer mixture forming the acrylic copolymer (A) is more than 90% by weight. From the viewpoint of maintaining the transparency of the anti-fogging coating film after the long-term water resistance test, the total proportion of the monomers (a1) to (a3) in the monomer mixture forming the acrylic copolymer (A) is 91 weight% or more is preferable and 95 weight% or more is more preferable.

  The proportion of the monomer (a4) in the monomer mixture forming the acrylic copolymer (A) is 0% by weight or more from the viewpoint of maintaining the transparency of the antifogging coating film after the long-term water resistance test. It is preferably less than 10% by weight, more preferably 0% by weight or more and 9% by weight or less, and further preferably 0% by weight or more and 5% by weight or less.

  The proportion of the other monomer in the monomer mixture forming the acrylic copolymer (A) is preferably 10% by weight or less, more preferably 5% by weight or less, and further preferably 3% by weight or less.

<Method for Producing Acrylic Copolymer (A)>
The acrylic copolymer (A) of the present invention can be obtained by copolymerizing the monomer mixture. The structure of the copolymer may be any of a random copolymer, an alternating copolymer, a block copolymer, and a graft copolymer, but an antifogging agent composition including antifogging properties. The random copolymer is preferable from the viewpoint that the effect of the antifogging agent composition can be easily prepared. As a polymerization method for obtaining the copolymer, various known polymerization methods such as a radical polymerization method, a cationic polymerization method, an anion living polymerization method, and a cation living polymerization method are adopted. The radical polymerization method is preferred from the viewpoint of performance over many meanings. As the radical polymerization method, usual bulk polymerization method, suspension polymerization method, solution polymerization method, emulsion polymerization method and the like are adopted. However, the solution polymerization method can be used as it is as an antifogging agent composition after polymerization. Is preferred.

  Examples of the polymerization solvent used in the solution polymerization method include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, s-butanol, t-butanol, diacetone alcohol, 2-methyl-2-butanol ( Alcohol solvents such as tertiary amyl alcohol); ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, 3-methoxy-1-butanol, 3-methoxy-3-methyl-1 -Alcohol ether solvents such as butanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethers such as tetrahydrofuran and dioxane Solvents: ester solvents such as methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl lactate, ethyl lactate, etc .; aromatic solvents such as benzene, toluene, xylene, formamide, dimethylformamide, etc. The amide solvent, water, etc. are used. These polymerization solvents may be used in at least one kind, and can be used in combination of two or more kinds.

  Among the polymerization solvents, it is preferable to use a solvent (d1) and / or a solvent (d2) described later from the viewpoint that they can be used as they are as an antifogging agent composition after polymerization.

  In the solution polymerization, from the viewpoint of facilitating industrial production by suppressing the polymerization heat generation in the monomer mixture forming the acrylic copolymer (A) in a total of 100 parts by weight of the monomer mixture and the polymerization solvent. , 50 parts by weight or less is preferable, and 40 parts by weight or less is more preferable.

  As the initiator in the radical polymerization, generally used organic peroxides, azo compounds and the like can be used. Organic peroxides include benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-hexanoate, t-butylperoxypivalate, t-hexylperoxypi Examples include valet. Examples of the azo compound include 2,2'-azobisisobutyronitrile and 2,2'-azobis-2-methylbutyronitrile. It is preferable that the usage-amount of a radical polymerization initiator is 0.01-5 weight part with respect to 100 weight part of monomer mixtures. The radical polymerization initiator is preferably polymerized while being dropped into the reaction vessel in terms of easy control of the heat generated by polymerization. Although the temperature which performs a polymerization reaction is suitably changed with the kind of radical polymerization initiator to be used, when manufacturing industrially, it is preferably 30-150 degreeC, More preferably, it is 40-100 degreeC.

  The weight average molecular weight (Mw) of the acrylic copolymer (A) is preferably 5,000 or more and more preferably 10,000 or more from the viewpoint of imparting water resistance to the antifogging coating film. The weight average molecular weight (Mw) of the acrylic copolymer (A) is preferably 100,000 or less, and more preferably 50,000 or less, from the viewpoint of enhancing the paintability and handling properties of the antifogging agent composition.

The weight average molecular weight (Mw) of the acrylic copolymer (A) can be determined by the GPC method. The sample can be measured under the following conditions using a sample dissolved in dimethylformamide to give a 0.2 wt% solution and filtered through a 0.45 μm membrane filter.
<Measurement of weight average molecular weight (Mw)>
・ Analyzer: CR-4A (manufactured by Shimadzu Corporation)
·column:
KD-802.5 (Showa Denko)
KD-803 (made by Showa Denko)
KD-80M (Showa Denko)
-Column size: 8.0 x 300 mm
-Eluent: Dimethylformamide-Flow rate: 1.0 ml / min
-Detector: differential refractometer-Column temperature: 55 ° C
Standard sample: polystyrene

<Basic compound (B)>
The basic compound (B) of the present invention has a function of neutralizing a part of the sulfonic acid group of the monomer (a2) and a function of imparting an antifogging property to the antifogging coating film after a long-term water resistance test. Have By neutralizing a part of the monomer (a2) with the basic compound (B), the hydrophilicity of the antifogging coating film can be further increased.

  Examples of the compound in the basic compound (B) include sodium hydroxide, calcium hydroxide, ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, dimethylaminoethanol, Examples include diethylaminoethanol, aniline, α-naphthylamine, benzylamine, pyridine, 2,6-lutidine, and imidazole. As the basic compound (B), at least one kind may be used, and two or more kinds may be used in combination.

  The ratio of the basic compound (B) is more than 60 mol% and less than 95 mol% with respect to the sulfonic acid group of the monomer (a2). The proportion of the basic compound (B) is preferably 70 mol% or more based on the sulfonic acid group of the monomer (a2) from the viewpoint of imparting the antifogging property after the long-term water resistance test to the antifogging coating film. 75 mol% or more is more preferable. The proportion of the basic compound (B) is preferably 93 mol% or less with respect to the sulfonic acid group of the monomer (a2) from the viewpoint of maintaining the transparency of the antifogging coating film after the long-term water resistance test. The mol% or less is more preferable.

  A method of adding the basic compound after polymerization of the acrylic copolymer (A), a method of adding to the monomer mixture containing the monomer (a2) before polymerization of the acrylic copolymer (A), an acrylic copolymer It can be used by the method of adding to the monomer (a2) before polymerization of (A).

<Surfactant (C)>
The surfactant (C) of the present invention is a component for improving the antifogging property by reducing the surface tension of water adhering to the coating film surface and forming a water film on the coating film surface. As the surfactant, all conventionally known surfactants can be used, and examples thereof include nonionic surfactants, anionic surfactants, cationic surfactants, and zwitterionic surfactants. As the surfactant, at least one kind may be used, and two or more kinds may be used in combination. Among these, it is preferable that at least one or more anionic surfactants are contained from the viewpoint of sustaining the effect.

  Examples of the nonionic surfactant include polyoxyethylene lauryl alcohol, polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, and polyoxyethylene nonylphenol. Polyoxyethylene alkyl aryl ethers, polyoxyethylene acyl esters such as polyoxyethylene glycol monostearate, polypropylene glycol ethylene oxide adducts, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate and other polyoxyethylene Ethylene sorbitan fatty acid esters, alkyl phosphate esters, polyoxyethylene alkyl ether phosphate esters Phosphoric acid esters such as Le, sugar esters, such as cellulose ethers are used.

  Examples of the anionic surfactant include fatty acid salts such as sodium oleate and potassium oleate, higher alcohol sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate, alkylbenzenes such as sodium dodecylbenzenesulfonate and sodium alkylnaphthalenesulfonate. Sulfonates and alkyl naphthalene sulfonates, naphthalene sulfonic acid formalin condensates, dialkyl sulfosuccinates, dialkyl phosphate salts, polyoxyethylene sulfate salts such as sodium polyoxyethylene alkylphenyl ether sulfate, and the like are used.

  Examples of the cationic surfactant include ethanolamines, laurylamine acetate, triethanolamine monoformate, amine salts such as stearamide ethyl diethylamine acetate, lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, dilauryldimethylammonium. Quaternary ammonium salts such as chloride, distearyldimethylammonium chloride, lauryldimethylbenzylammonium chloride and stearyldimethylbenzylammonium chloride are used.

  Examples of the zwitterionic surfactant include fatty acid type zwitterionic surfactants such as dimethylalkyl lauryl betaine and dimethylalkylstearyl betaine, sulfonic acid type zwitterionic surfactants such as dimethylalkylsulfobetaine, and alkylglycine. Is used.

  The content of the surfactant (C) is preferably 1 part by weight or more, preferably 2 parts by weight or more with respect to 100 parts by weight of the acrylic copolymer (A), from the viewpoint of enhancing the antifogging property of the antifogging coating film. Further preferred. The content of the surfactant (C) is 100 parts by weight of the acrylic copolymer (A) from the viewpoint of increasing the transparency of the antifogging coating film and increasing the adhesion between the antifogging coating film and the substrate. On the other hand, it is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less.

  As a method for mixing the surfactant (C) and the acrylic copolymer (A), the acrylic copolymer (A) is dissolved in, for example, a solvent (D) and the surfactant (C) is contained therein. ) May be added, and the surfactant (C) may be added together when the acrylic copolymer (A) is produced.

<Solvent (D)>
The solvent (D) of the present invention contains at least an alcohol having a boiling point of 64 ° C. or higher and 250 ° C. or lower, including a monohydric alcohol (d1) having 2 to 3 carbon atoms and 2-methyl-2-butanol (d2). To do.

<Solvent (d1)>
The solvent (d1) of the present invention is a monohydric alcohol having 2 to 3 carbon atoms, and examples include ethanol (boiling point 78 ° C.), n-propanol (boiling point 97 ° C.), and isopropanol (boiling point 82 ° C.). As the solvent (d1), at least one kind may be used, and two or more kinds may be used in combination.

<Solvent (d2)>
The solvent (d2) of the present invention is 2-methyl-2-butanol (tertiary amyl alcohol) (boiling point 102 ° C.).

<Solvent (d3)>
The solvent (d3) of the present invention is an alcohol having a boiling point other than the solvent (d1) and the solvent (d2) of 64 ° C. or higher and 250 ° C. or lower.

  As the solvent (d3) of the present invention, methyl alcohol (boiling point 64 ° C.), propylene glycol monoethyl ether (boiling point 120 ° C.), n-butanol (boiling point 117 ° C.), isopropyl diglycol (boiling point 207 ° C.), methyl triglycol (Boiling point 249 ° C.).

<Other solvents>
From the viewpoint of maintaining the transparency of the coating film after the long-term water resistance test, it is preferable that the antifogging agent composition of the present invention does not contain a solvent having a high boiling point, for example, a solvent having a boiling point exceeding 250 ° C.

  The proportion of the alcohol having a boiling point of 64 ° C. or more and 250 ° C. or less in the solvent (D) is 96.5% by weight or more. In the solvent (D), the proportion of the alcohol having a boiling point of 64 ° C. or more and 250 ° C. or less is preferably 97% by weight or more from the viewpoint of maintaining the transparency of the anti-fogging coating film after the long-term water resistance test. % By weight or more is more preferable, and 99% by weight or more is more preferable.

  The ratio of the solvent (d1) in the solvent (D) is 76.5% by weight or more and 96.0% by weight or less. From the viewpoint of maintaining the transparency of the anti-fogging coating film after the long-term water resistance test, it is preferably 77% by weight or more, more preferably 80% by weight or more, and further preferably 85% by weight or more. The ratio of the solvent (d1) in the solvent (D) is preferably 95% by weight or less, more preferably 94% by weight or less, and still more preferably 93% by weight or less, from the viewpoint of imparting transparency to the antifogging coating film. .

  The proportion of the solvent (d2) in the solvent (D) is preferably 4% by weight or more, more preferably 5% by weight or more, and further preferably 6% by weight or more from the viewpoint of imparting transparency to the anti-fogging coating film. . The ratio of the solvent (d2) in the solvent (D) is preferably 23% by weight or less, more preferably 20% by weight or less, from the viewpoint of maintaining the transparency of the antifogging coating film after the long-term water resistance test. More preferably, it is not more than% by weight.

  The content of the solvent (d2) is preferably more than 40 parts by weight and more preferably 45 parts by weight or more with respect to 1000 parts by weight of the solvent (d1) from the viewpoint of imparting transparency to the antifogging coating film. The content of the solvent (d2) is preferably less than 310 parts by weight and less than or equal to 300 parts by weight with respect to 1000 parts by weight of the solvent (d1) from the viewpoint of maintaining the transparency of the antifogging coating film after the long-term water resistance test. Is more preferable.

  The total proportion of the solvents (d1) and (d2) in the solvent (D) is more than 95.5% by weight. The total proportion of the solvents (d1) and (d2) in the solvent (D) is preferably 96% by weight or more and 97% by weight or more from the viewpoint of maintaining the transparency of the antifogging coating film after the long-term water resistance test. More preferred is 98% by weight or more.

  The proportion of the solvent (d3) in the solvent (D) is preferably 4% by weight or less, more preferably 3% by weight or less, and not contained in the solvent (D), from the viewpoint of imparting transparency to the antifogging coating film. Most preferred.

  The content of the solvent (d3) is preferably less than 50 parts by weight with respect to 1000 parts by weight of the solvent (d1) from the viewpoint of maintaining the transparency of the antifogging coating film after a long-term water resistance test, and 45 parts by weight. The following is more preferable, 40 parts by weight or less is further preferable, 30 parts by weight or less is further more preferable, and it is most preferable that the solvent (D) is not included.

<Other ingredients>
The anti-fogging agent composition of the present invention can contain various conventional additives such as a leveling agent, an antioxidant, an ultraviolet absorber and a light stabilizer as necessary as other components.

<Manufacture of anti-fogging agent composition>
The antifogging agent composition comprises, for example, an acrylic copolymer (A) or a solution of an acrylic copolymer (A), a basic compound (B), and a surfactant (C), which are suitable for coating. For the purpose of adjusting the viscosity, the solvent (D) can be added to dissolve, disperse or dilute. The solid content and viscosity suitable for coating differ depending on the coating method, but in the case of the spray coating method, the acrylic copolymer (A) is preferably 2% by weight or more in the antifogging agent composition, and 5% by weight. The above is more preferable, 30% by weight or less is preferable, and 20% by weight or less is more preferable.

<Anti-fog coating>
The anti-fogging agent composition of the present invention can form an anti-fogging coating film on the surface of an object to be coated by coating the object to be coated by a coating method performed in a normal paint, followed by drying and heat curing.

  As the object to be coated, a known resin base material can be used regardless of the type, and polymethyl methacrylate resin, polycarbonate resin, polystyrene resin, acrylonitrile / styrene copolymer resin, polyvinyl chloride resin, acetate resin, ABS resin, polyester resin, polyamide resin and the like can be mentioned.

  When applying to the object to be coated, in order to increase the wettability of the anti-fogging agent composition to the object to be coated and to prevent the repelling, removal of foreign matter adhered to the surface of the object to be coated, degreasing, and washing are performed. Preferably it is done. Specific examples include dust removal with high-pressure air or ionized air, ultrasonic cleaning with an aqueous detergent solution or alcohol solvent, wiping using an alcohol solvent, cleaning with ultraviolet rays and ozone, and the like. As the coating method, a dipping method, a flow coating method, a roll coating method, a bar coating method, a spray coating method and the like are suitable.

  The drying is a step of evaporating and drying the solvent contained in the coating film at a temperature of 20 to 50 ° C. for 0.5 to 5 minutes.

  In the case where the object to be coated is a resin base material, the heating needs to be set to a heating temperature equal to or lower than the heat deformation temperature of the resin base material, but from the viewpoint of preventing slight deformation of the resin base material, The temperature is preferably 5 ° C. or less, more preferably 10 ° C. or less, from the heat distortion temperature of the substrate. For example, when the resin base material is a polymethyl methacrylate resin, it is preferably 60 ° C. or lower, and when it is a polycarbonate resin, it is preferably 110 ° C. or lower. For example, when the heating temperature is 60 ° C., the heating time is preferably 30 minutes or more, and more preferably 40 minutes or more. For example, when the heating temperature is 110 ° C., the heating time is preferably 5 minutes or more, and more preferably 10 minutes or more.

  The film thickness of the antifogging coating film is preferably 0.5 μm or more and more preferably 1.0 μm or more from the viewpoint of enhancing the antifogging property of the antifogging coating film. The film thickness of the antifogging coating film is preferably 10 μm or less, more preferably 5 μm or less, from the viewpoint of enhancing the smoothness of the antifogging coating film.

  The resin member on which the antifogging coating film is formed is preferably used for a vehicle lamp. Specific vehicle lights include headlights, auxiliary headlights, vehicle width lights, number lights, tail lights, parking lights, braking lights, reverse lights, direction indicators, auxiliary direction indicators, emergency flashing indicators, etc. Can be mentioned.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these implementation.

<Raw material>
The compounds used in Examples or Comparative Examples are shown below.
<Acrylic copolymer (A)>
<Monomer (a1)>
N-methylolacrylamide (N-MAA)
N-butoxymethylacrylamide (N-BMA)
<Monomer (a2)>
2-acrylamido-2-methylpropanesulfonic acid (AMPS)
2- (Methacryloyloxy) ethanesulfonic acid (MAES)
<Monomer (a3)>
Methyl methacrylate (MMA)
n-Butyl acrylate (BA)
<Monomer (a4)>
N, N-dimethylacrylamide (DMAA)
N, N-diethylacrylamide (DEAA)
<Basic compound (B)>
Triethanolamine Imidazole Sodium hydroxide <Surfactant (C)>
Sodium dioctylsulfosuccinate (manufactured by NOF Corporation, trade name: Rapisol A80)
<Solvent (D)>
<Solvent (d1)>
n-propanol (NPA)
<Solvent (d2)>
2-Methyl-2-butanol (tertiary amyl alcohol) (TAA)
<Solvent (d3)>
Methyl alcohol (MeOH)
Propylene glycol monoethyl ether (PGM)
n-Butanol (NBA)
Isopropyl diglycol (iPDG)
Methyl triglycol (MTG)
<Others>
Butyl triglycol (BTG)
<Leveling agent>
Polyether-modified polydimethylylsiloxane (BYK-333, manufactured by BYK Chemie)

<Example 1>
<Production of acrylic copolymer (A)>
In a reaction vessel equipped with a stirrer, a nitrogen introducing tube and a cooling tube, 275 parts by weight of n-propanol (NPA) as a solvent (d1) and 10 parts by weight of N-methylolacrylamide (N-MAA) as a monomer (a1) 15 parts by weight of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as the monomer (a2), 55 parts by weight of methyl methacrylate (MMA) as the monomer (a3), and n-butyl acrylate (BA) 17. 5 parts by weight, N, N-dimethylacrylamide (DMAA) 2.5 parts by weight as monomer (a4), and 9.7 g of triethanolamine (monomer (a2) of AMPS as basic compound (B)) Amount equivalent to 90 mol% with respect to sulfonic acid group, calculation method; {AMPS charged parts by weight} ÷ molar mass of AMPS × 90% ÷ 100 × {triethanol Charged molar mass} = 15 ÷ 207.4 × 90 ÷ 100 × 149.2 = 9.7) of the amine and heated to 65 ° C. while blowing nitrogen gas. Thereto, 1.6 parts by weight of a hydrocarbon diluted product of t-hexylperoxypivalate as a radical polymerization initiator (trade name: Perhexyl PV manufactured by NOF Corporation) was dissolved in 35 parts by weight of NPA as a solvent (d1). Was added dropwise over 3 hours. After further polymerization for 4.5 hours, the temperature was raised to 80 ° C., and polymerization was carried out at that temperature for 1.5 hours to obtain a copolymer (weight average molecular weight (Mw) = 150,000) of Example 1 acrylic. A solution of copolymer (A) was obtained.

<Manufacture of anti-fogging agent composition>
371.3 parts by weight of the acrylic copolymer (A) solution (100 parts by weight of the acrylic copolymer (A), 9.7 parts by weight of the basic compound (B), 260 parts by weight of NPA as the solvent (d1)) Part)), 740 parts by weight of NPA and 300 parts by weight of 2-methyl-2-butanol (tertiary amyl alcohol) (TAA) were added to adjust the copolymer concentration to 7.1% by weight. C) 10 parts by weight of sodium di-2-ethylhexylsulfosuccinate (trade name: Rapisol A-80 (active ingredient 80% by weight) manufactured by NOF Corporation) (8 parts by weight in terms of pure product, 2 parts by weight remaining) And methanol- and water)) and 0.05 parts by weight of polyether-modified polydimethylsiloxane (trade name: BYK-333 manufactured by Big Chemie Japan Co., Ltd.) as a leveling agent. It was obtained antifogging agent composition of Example 1.

<Examples 2 to 22>
<Production of acrylic copolymer (A)>
Except having changed into the monomer of Table 1, and the basic compound, the method of Example 1 was used and the solution of the acrylic copolymer (A) of Examples 2-22 was obtained.

<Manufacture of anti-fogging agent composition>
The antifogging agent of Example 1 except that the acrylic copolymer (A) of Example 1 was changed to the acrylic copolymer (A) of Examples 2 to 22 and changed to the solvent (D) of Table 1. The antifogging agent compositions of Examples 2 to 22 were obtained by the method described in the production of the composition.

<Creation of anti-fogging coating film>
Each antifoggant composition obtained above was applied to a polymethyl methacrylate resin plate by a spray coating method so that the film thickness after curing was 2 to 3 μm, dried at room temperature for 5 minutes, and then 60 Heat curing at 40 ° C. for 40 minutes was performed to obtain a test piece of an antifogging coating film. About these anti-fogging coating films, evaluation of following (1)-(5) was performed. The results are shown in Table 1.

(1) Evaluation of steam antifogging property The test piece was placed at a height of 5 cm from the water surface of a warm water bath in which the test piece of the antifogging coating was kept at 40 ° C. The antifogging coating film was continuously irradiated with steam from a warm water bath, and the presence or absence of fogging after 300 seconds from the irradiation was visually evaluated. The case where no cloudiness was observed and a smooth water film was formed was marked with ◎, and the case where cloudiness was not observed but the water film was not smooth but was rough was marked with ×.

(2) Evaluation of transparency of coating film The transparency of the test piece of the anti-fogging coating film was visually evaluated. A transparent material was marked with ◯, and a white material with whitening was marked with ×.

(3) Evaluation of adhesion The presence or absence of peeling of the antifogging coating film was visually evaluated based on JIS K 5400 8.5.1. A sample in which no separation was observed was marked with ◯, and a sample in which separation was observed was marked with ×.

(4) Evaluation of transparency of coating film after long-term water resistance test After immersing a test piece of anti-fogging coating film in warm water at 40 ° C for 240 hours, it was dried at room temperature, and the appearance of the anti-fogging coating film was visually evaluated. . The case where it was exactly the same as the state of the initial coating film and no change was observed was rated as ○, and the case where whitening or dissolution of the coating film was observed was rated as x.

(5) Evaluation of breath anti-fogging property after long-term water resistance test After immersing the test piece of the anti-fogging coating film in warm water of 40 ° C. for 240 hours, it is dried at room temperature and exhaled at room temperature on the test piece of the anti-fogging coating film. And the presence or absence of cloudiness was visually evaluated. The case where cloudiness was not recognized was rated as ◯, and the case where cloudiness was observed was rated as x.

Comprehensive evaluation In the evaluations of (1) to (5) above, a case where there is no x in any evaluation is ○, a case where x is at least in any evaluation is x, and a case where the overall evaluation is ○ is practical. no problem.

<Comparative Examples 1-17>
<Production of acrylic copolymer (A)>
Except having changed into the monomer of Table 2, and the basic compound, the method of Example 1 was used and the solution of the acrylic copolymer (A) of Comparative Examples 1-17 was obtained.

<Manufacture of anti-fogging agent composition>
The antifogging agent of Example 1 except that the acrylic copolymer (A) of Example 1 was changed to the acrylic copolymer (A) of Comparative Examples 1 to 17 and the solvent (D) of Table 2 was changed. The antifogging agent compositions of Comparative Examples 1 to 17 were obtained by the method described in the production of the composition.

<Creation of anti-fogging coating film>
The test piece of the anti-fogging coating film of Comparative Examples 1-17 was obtained by the method as described in an Example. About these anti-fogging coating films, evaluation of said (1)-(5) was performed. The results are shown in Table 2.

  The anti-fogging coating films obtained by heat-curing the anti-fogging agent compositions of Examples 1 to 22 at 60 ° C. for 40 minutes satisfy all the evaluation criteria of (1) to (5). Was confirmed. Therefore, according to the anti-fogging agent composition of Examples 1 to 22, the anti-fogging coating film having anti-fogging properties required for vehicle lamps under low temperature and short time conditions than the conventional anti-fogging agent composition. It was found that it can be formed.

The antifogging coating film of Comparative Examples 1-2 is from the antifogging agent composition in which the content of the solvent (d2) contained in the antifogging agent composition is not the predetermined amount of the present invention with respect to the solvent (d1). It is the obtained coating film. Moreover, the antifogging coating films of Comparative Examples 3 to 9 have a content of any of the monomers (a1) to (a4) forming the acrylic copolymer (A) or the basic compound (B), It is the coating film obtained from the anti-fogging agent composition which is not the predetermined amount of this invention. Furthermore, the antifogging coating films of Comparative Examples 10 to 17 have a predetermined content of the present invention in which the content of alcohol having a boiling point of 64 ° C. or more and 250 ° C. or less including (d1) and (d2) contained in the solvent (D) is It is the coating film obtained from the antifogging agent composition which is not.
It was confirmed that the anti-fogging coating films of Comparative Examples 1 to 17 cannot satisfy at least one evaluation criterion in the evaluations (1) to (5). Therefore, in the antifogging agent compositions of Comparative Examples 1 to 17, it is not possible to form an antifogging coating film having antifogging properties required for vehicle lamps at a lower temperature and in a shorter time than conventional antifogging agent compositions. I understood it.

Claims (4)

An antifogging agent composition comprising an acrylic copolymer (A), a basic compound (B), a surfactant (C), and a solvent (D),
The acrylic copolymer (A) is represented by the following general formula (1)
[In the general formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is a straight-chain or branched-chain alkyl group having 1 to 4 carbon hydrogen atom or a carbon. A monomer (a1) represented by
The following general formula (2)
[In the general formula (2), R ³ is a hydrogen atom or a methyl group, X is O or NH, and R ⁴ is a linear or branched alkylene group having 1 to ⁴ carbon atoms. And a monomer (a2) represented by the following general formula (3)
[In the general formula (3), R ⁵ is a hydrogen atom or a methyl group, R ⁶ is a straight-chain or branched-chain alkyl group having 1 to 4 carbon atoms. An acrylic copolymer formed from a monomer mixture containing a monomer (a3) represented by
In the monomer mixture, the proportion of monomer (a1) is more than 6% by weight, less than 13% by weight, the proportion of monomer (a2) is more than 11% by weight, less than 19% by weight, and monomer The total proportion of (a1) to (a3) is over 90% by weight,
The proportion of the basic compound (B) is more than 60 mol% and less than 95 mol% with respect to the sulfonic acid group of the monomer (a2),
The solvent (D) contains an alcohol having a boiling point of 64 ° C. or more and 250 ° C. or less, including at least a monohydric alcohol (d1) having 2 to 3 carbon atoms and 2-methyl-2-butanol (d2),
The ratio of the alcohol having a boiling point of 64 ° C. or more and 250 ° C. or less in the solvent (D) is 96.5% by weight or more,
The total proportion of (d1) and (d2) in the solvent (D) is more than 95.5% by weight;
The anti-fogging agent composition whose ratio of said (d1) in the said solvent (D) is 76.5 weight% or more and 96.0 weight% or less.
In addition to the monomer mixture, the following general formula (4)
[In the general formula (4), R ⁷ is a hydrogen atom or a methyl group, R ⁸ is a hydrogen atom or a linear alkyl group having 1 to 3 carbon atoms, and R ⁹ is a linear alkyl group having 1 to 3 carbon atoms. R ⁸ and R ⁹ may be the same or different. ] The antifogging agent composition of Claim 1 containing the monomer (a4) represented by these.
The proportion of alcohol (d3) having a boiling point other than (d1) and (d2) in the solvent (D) of 64 ° C or higher and 250 ° C or lower is 4.5% by weight or less. An antifogging agent composition described in 1.
A coated article obtained by applying the antifogging agent composition according to any one of claims 1 to 3 to an object to be coated, and heating and curing the antifogging agent composition.