JP4332751B2 - Curable anti-fogging coating composition - Google Patents

Description

  The present invention relates to a curable antifogging coating agent composition. In particular, the present invention relates to a curable antifogging coating agent composition used for plastic articles such as lamp lenses for vehicle lamps, curved mirrors installed outdoors, shields for helmets, etc., which require transparency.

  Polymethacrylate resin (PMMA), polycarbonate resin (PC), polyethylene terephthalate resin (PET), vinyl chloride resin (PVC), etc. are excellent in transparency, moldability, and mechanical properties, and are particularly lightweight compared to glass. Since it has the advantages of excellent impact resistance, low cost and easy molding, it is widely used in many fields. Specifically, taking advantage of such performance, automotive applications such as headlamp lenses, side lamps and tail lamp materials, or curved mirrors, helmet shields, plastic lenses for eyeglasses, packaging films, agriculture installed outdoors It is often used for sheet.

  However, in general, a synthetic resin material is likely to be clouded due to water existing in the air as water droplets due to a rapid temperature change in a high humidity environment. For example, when a headlamp or tail lamp of an automobile is lit in a high humidity environment, a rapid temperature change may occur on the inner surface and the outer surface of the cover of the lamp, and fogging due to small water droplets may occur on the inner surface. As a result, the aesthetics of the portion may be impaired, and the product value may be reduced, and further, the illumination luminance may be lowered, resulting in a safety obstacle.

  Various proposals have been made as methods for preventing such cloudiness caused by water droplets. For example, (1) a method of applying a surfactant to the substrate surface (see Patent Document 1), (2) a method of applying a coating agent containing a hydrophilic resin and a surfactant to the substrate surface (Patent Document 2) (3) A method of forming a film having photocatalytic activity on the surface of the substrate (see Patent Document 3), (4) An electric heater is applied to the inside or the back surface of the substrate, and the substrate is heated by energization. Then, there is a method of making the dew point or higher (see Patent Document 4).

  However, the method (1) is excellent in the initial antifogging property, but has a disadvantage that the applied antifogging agent is washed away by the attached water or rainwater, and the antifogging effect is lost. Therefore, it is limited to applications that can be repeatedly applied such as agricultural vinyl sheets and eyeglass lenses. The method (2) expresses antifogging properties by the effect of the hydrophilic resin and the bleed effect of the surfactant, and has a relatively long antifogging effect, but in some cases, it is the same as (1) In some cases, the anti-fogging effect is lost due to washing away the surfactant and the water resistance of the hydrophilic resin is low, resulting in coating film defects. The method (3) is a film made of an inorganic substance such as titanium oxide, so it has excellent physical strength. However, ultraviolet light is necessary for the development of anti-fogging properties, and functions in all environments. is not. The method (4) has an excellent anti-fogging effect, but its usage is extremely limited due to cost and power supply problems.

In view of the current situation as described above, in general, the method (2) is considered to be the most practical from the viewpoints of performance, cost, and versatility, and various hydrophilic properties are particularly aimed at improving performance. Proposals for resins have been made. For example, a block copolymer comprising a polymer part of a hydrophilic monomer selected from (meth) acrylamide derivatives and hydroxyalkyl (meth) acrylate and a polymer part of a hydrophobic monomer (see Patent Document 5) ), And a block or graft copolymer comprising a polymer part of N-methylol (meth) acrylamide and a hydrophilic monomer and a polymer part of a hydrophobic monomer (see Patent Document 6). However, both have problems from the viewpoint of cost and stable production because they employ a complicated polymerization method for synthesizing a block or graft copolymer. Further, in the former case, it is a photopolymerizable composition, and there is a defect that causes a decrease in the antifogging effect and a coating film defect unless sufficient crosslinking reaction is caused by curing by light irradiation. For this reason, unevenness occurs on the light-irradiated surface of the molded product having a complicated shape, which causes a problem. In the latter case, it is a thermosetting antifogging coating composition by N-methylol group, but in order to obtain a coating film having good performance, a strict treatment of a curing time of 30 minutes or more at a high temperature of 120 ° C. or higher. Conditions are needed. Accordingly, when the curing temperature is lowered for the purpose of coating or saving energy on a plastic material whose heat distortion temperature is not so high, the coating film is insufficiently cured, resulting in a decrease in water resistance. There is also a proposal to lower the curing temperature by adding an acidic phosphoric acid alkyl ester as a catalyst to the heat curable antifogging coating composition (see Patent Document 7), but it is difficult to control the curing rate, the drying temperature, Curing may be incomplete depending on the coating environment and the solvent, causing a decrease in water resistance, a whitening phenomenon of the coating film, and the like. Furthermore, depending on the acid catalyst used, corrosion of the coating tool or the like becomes a problem.
Japanese Patent Laid-Open No. 2-16185 JP 2001-40294 A Japanese Patent No. 2943768 JP-A-8-317841 JP-A-4-21461 JP-A-6-212146 JP 2003-105255 A

  An object of the present invention is a coating agent capable of imparting antifogging properties to a substrate surface by a hydrophilic treatment, which can be easily cured and dried at room temperature, and the resulting coating film has water resistance and antifogging properties. Another object is to provide a novel anti-fogging coating agent composition which has both excellent anti-fogging effect and durability.

  The present inventor has intensively studied to solve the above problems. As a result, a copolymer obtained by polymerizing an isocyanate group-containing (meth) acrylate, a hydrophilic component N-substituted (meth) acrylamide, and a vinyl monomer has an isocyanate group contained therein in the air. Can self-crosslink even under mild conditions due to moisture present, and by using the above copolymer as an anti-fogging coating agent, it has both water resistance and anti-fogging property and has a long-lasting anti-fogging effect. It was found that an excellent coating film can be formed. Furthermore, it has been found that a more durable antifogging effect can be obtained by adding a surfactant.

That is, the present invention provides a curable antifogging coating agent composition as shown below.
Item 1. Isocyanatoethyl (meth) acrylate (a), general formula [II];

(Wherein R ³ represents a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R ⁵ represents a linear chain having 1 to 4 carbon atoms. A copolymer obtained by polymerizing an N-substituted alkyl (meth) acrylamide (b) and a (meth) acrylate monomer (c). Is a curable anti-fogging coating agent composition comprising, as an active ingredient, the sum of isocyanatoethyl (meth) acrylate (a) and N-substituted alkyl (meth) acrylamide (b) constituting the copolymer (p) Is a curable antifogging coating agent composition in which is is 50 to 99% by weight and isocyanatoethyl (meth) acrylate (a) is 5 to 30% by weight .
Item 2 . Item 2. The curable antifogging coating agent composition according to item 1, further comprising a surfactant, wherein the ratio of the copolymer (p) and the surfactant is 100: 0.1 to 20 in terms of solid content weight ratio.
Item 3 . Item 3. The curable antifogging coating composition according to Item 2 , wherein the surfactant is a polyoxyethylene alkyl ether having HLB = 6 to 11.

  Hereinafter, the present invention will be described in detail.

The copolymer (p) contained as an active ingredient in the curable antifogging coating agent composition of the present invention is an isocyanatoethyl (meth) acrylate (a), an N-substituted alkyl (meth) acrylamide (b), and It can be obtained by polymerizing a monomer mixture containing one or more monomers each selected from the (meth) acrylate monomer (c).

In the present invention, component (a) isocyanatoethyl (meth) acrylate is a (meth) acrylate monomer having a functional group that contributes to the following curing reaction.
-NCO + H ₂ O → -NH ₂ + CO ₂
-NH ₂ + -NCO → -NH-CO-NH-
That is, in the first stage of the curing reaction, an isocyanate group releases carbon dioxide in the presence of water to generate an amino group. In the second stage, a urea bond is generated from the reaction between the produced amino group and another isocyanate group, and the copolymer (p) is crosslinked.

  Such a reaction makes it possible to exhibit sufficient strength of the antifogging coating film, stable antifogging effect for a long period of time, and adhesion to a substrate even under mild conditions. In addition, the isocyanate group in the present invention also acts to efficiently fix the surfactant contained in the curable antifogging coating composition described later on the surface of the coating film, enabling a long-term stable antifogging effect. To do.

Since isocyanatoethyl (meth) acrylate is used as the component (a), it is preferable from the viewpoint of the reaction rate (curing rate) of the curing reaction, polymerizability, and stability of the obtained copolymer (p).

  The curable antifogging coating agent composition of the present invention can adjust the crosslinking density to an optimum value depending on the proportion of the component (a) in the copolymer (p), and the amount is 5 to 30% by weight. preferable. When it is less than 5% by weight, the crosslinking density of the coating film is insufficient, and there is a possibility that sufficient water resistance and durability of the antifogging effect cannot be obtained. When it exceeds 30% by weight, the crosslinking density becomes too high, and the antifogging effect and the adhesion to the substrate may be lowered.

(B) above is a component N- substituted alkyl (meth) acrylamide represented by the general formula [II];

(In the formula, R ³ represents a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R ⁵ represents a linear chain having 1 to 4 carbon atoms. Jo or shows a branched alkyl group.) is represented by N- substituted alkyl (meth) acrylamide.

  Specific examples of N-substituted alkyl (meth) acrylamides include N-methyl (meth) acrylamide, N, N′-dimethyl (meth) acrylamide, N-ethyl (meth) acrylamide, and N, N′-diethyl (meth). Examples include acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and Nn-butyl (meth) acrylamide.

Component (b), N-substituted alkyl (meth) acrylamide, is a hydrophilic polymerizable monomer, is involved in maintaining excellent antifogging properties for a long period of time and improving heat resistance, and at the same time achieves both water resistance. Indispensable for. That is , N-substituted alkyl (meth) acrylamide represented by the general formula [II] is preferable from the viewpoint of moderate hydrophilicity, stability of the obtained copolymer (p) and physical properties. Further, among these N-substituted alkyl (meth) acrylamides (b) , N, N′-diethyl (meth) acrylamide and N-isopropyl (meth) acrylamide are preferable. In the present invention, unsubstituted (meth) acrylamide cannot be obtained with sufficient water resistance to withstand use due to its extreme hydrophilicity, and also has low solubility in organic solvents and low copolymer stability. I can not use it.

The antifogging performance and water resistance of the coating film can be controlled by the proportion of the component (b) in the copolymer (p). Moreover, it is necessary to consider the crosslinking density of the coating film by (a) component for the ratio of (b) component. Specifically, the amount of component (b) is 50 to 99% by weight of the total of isocyanatoethyl (meth) acrylate (a) and N-substituted alkyl (meth) acrylamide (b) constituting the copolymer (p). And isocyanatoethyl (meth) acrylate (a) in the range of 5 to 30% by weight. That is, the amount of the component (b) in the copolymer (p) is 20 to 94% by weight. If it is less than 20% by weight, a sufficient antifogging effect may not be obtained. If it exceeds 94% by weight, the penetrating ability of water into the coating film becomes too strong, and the coating film strength may be lowered.

The ( meth) acrylate monomer as the component (c) is necessary for improving the physical properties of the coating film, for example, the hardness, heat resistance, impact resistance and the like of the coating film. From the viewpoint of the storage stability of the copolymer (p), the (meth) acrylate monomer (c) preferably has no active hydrogen group that reacts with an isocyanate group, and the alkyl group has 1 to 18 carbon atoms. (Meth) acrylic acid alkyl ester, for example, (meth) acrylic acid methyl, ethyl, propyl, butyl, octyl, 2-ethylhexyl, decyl, dodecyl, stearyl ester and the like. Further, ether oxygen-containing alkyl esters having 3 to 18 carbon atoms of (meth) acrylic acid, for example, methoxyethyl ester, ethoxyethyl ester, methoxypropyl ester, methyl carbyl ester, ethyl carbyl ester, butyl carbyl ester, etc. It is done.

  The proportion of the component (c) in the copolymer (p) is preferably 1 to 50% by weight. If it is less than 1% by weight, sufficient physical properties may not be improved. If it exceeds 50% by weight, the effects of the components (a) and (b) described above may not satisfy the object of the present invention.

  The method for obtaining a copolymer (p) by copolymerizing a monomer mixture containing the component (a), the component (b), and the component (c) is not particularly limited, and various conventionally known polymerization methods are available. Can be used. For example, the copolymer (p) is obtained by reacting the monomer mixture in the presence of a radical polymerization initiator at a reaction temperature of 60 to 120 ° C., more preferably 75 to 100 ° C. for 3 to 12 hours. It is done. In particular, solution polymerization is advantageous from the viewpoint of productivity and workability.

  As the polymerization initiator, for example, azo compounds such as 2,2'-azobisisobutyronitrile and 2,2'-azobis-2-methylbutyronitrile, and peroxides such as benzoyl peroxide are preferable. The amount of the polymerization initiator used is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the monomer mixture.

  As an organic solvent used for solution polymerization, an organic solvent that does not have an active hydrogen group that reacts with an isocyanate group can be used alone or in admixture of two or more. Specific examples of such organic solvents include ester solvents such as ethyl acetate and butyl acetate, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, aromatic solvents such as toluene and xylene, methyl cyclohexane and ethyl cyclohexane. And aliphatic solvents such as tetrahydrofuran and ether solvents such as tetrahydrofuran and dioxane. From the viewpoint of stability during polymerization, drying properties during coating, and influence on the substrate to be coated, the boiling point of the solvent is preferably 60 ° C to 180 ° C.

  The curable antifogging coating agent composition of the present invention comprises a copolymer (a) obtained by copolymerizing a monomer mixture containing the component (a), the component (b), and the component (c) by various polymerization methods. p) The solution may be used as it is. Moreover, an organic solvent can be added as needed. In that case, it is necessary to consider the boiling point suitable for the coating conditions, the evaporation rate, the solubility of the copolymer (p) and the influence on the coating substrate, and the organic solvent to be added is an active hydrogen that reacts with an isocyanate group. It is necessary to select one having no group.

  Furthermore, in the curable antifogging coating agent composition of the present invention, a surfactant can be blended as necessary. As this surfactant, one or more surfactants selected from anionic surfactants, cationic surfactants, zwitterionic surfactants and nonionic surfactants are generally used. It is an agent.

  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, sodium dodecylbenzenesulfonate, and sodium alkylnaphthalenesulfonate. Examples thereof include alkylbenzene sulfonates and alkyl naphthalene sulfonates, naphthalene sulfonate formalin condensates, dialkyl sulfosuccinates, dialkyl phosphate salts, polyoxyethylene sulfate salts such as sodium polyoxyethylene alkylphenyl ether sulfate, and the like.

  Examples of cationic surfactants include amine salts such as ethanolamines, laurylamine acetate, triethanolamine monoformate, stearamide ethyl diethylamine acetate, lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, dilauryldimethyl. And quaternary ammonium salts such as ammonium chloride, distearyldimethylammonium chloride, lauryldimethylbenzylammonium chloride, and stearyldimethylbenzylammonium chloride.

  Examples of the zwitterionic surfactant include fatty acid type amphoteric surfactants such as dimethylalkyl lauryl betaine and dimethylalkyl stearyl betaine, sulfonic acid type amphoteric surfactants such as dimethylalkyl sulfobetaine, and alkylglycine. .

  Nonionic surfactants include, for example, polyoxyethylene higher alcohol ethers such as polyoxyethylene lauryl alcohol, polyoxyethylene lauryl ether and polyoxyethylene oleyl ether, polyoxyethylene octylphenol, polyoxyethylene nonylphenol and other polyoxyethylene nonylphenol. Polyoxyethylene such as oxyethylene alkyl aryl ethers, polyoxyethylene acyl esters such as polyoxyethylene glycol monostearate, polypropylene glycol ethylene oxide adduct, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate Such as sorbitan fatty acid esters, alkyl phosphate esters, polyoxyethylene alkyl ether phosphate esters, etc. Acid esters, sugar esters, and cellulose ethers and the like.

  Of these, nonionic surfactants or anionic surfactants are preferred from the viewpoints of the bleeding effect from the coating film, the adsorptivity to the coating film surface, and the chemical stability of the surfactant. A polyoxyethylene alkyl ether having HLB = 6 to 11 as a nonionic surfactant is particularly preferred from the viewpoint of maintaining the antifogging effect and preventing the appearance of the coating film from changing.

  The blending ratio of these surfactants is preferably solid (weight ratio): copolymer (p): surfactant = 100: 0.1-20, copolymer (p): surfactant = More preferably, it is 100: 1-10. When the blending amount of the surfactant is less than 0.1 parts by weight, there is a possibility that the antifogging improvement due to the addition of the surfactant may not be recognized, and when it exceeds 20 parts by weight, the water resistance of the coating film There is a risk that the strength will be low.

  In the curable antifogging coating composition of the present invention, if necessary, various conventional additives such as an ultraviolet absorber, a leveling agent, a rheology control agent, a curing catalyst, an antioxidant, a dispersant, a dye, and a pigment are blended. can do. In particular, the curing catalyst may be an organic tin-based catalyst such as dibutyltin dilaurate or dibutyltin dioctoate, an organic lead-based catalyst such as lead octoate, or triethylamine, dimethyloctylamine, diazabicyclone, depending on the coating conditions. A catalyst of a tertiary amine compound such as decene can be used. Moreover, if it is in the range which does not prevent the effect of this invention, it can also modify | denature with compatible resin as needed. For example, polyethylene glycol, polypropylene glycol, acrylic resin, polyester resin, or the like can be used.

  The above-mentioned method of blending the surfactant and additive may be added in advance to the copolymer (p) solution, but is preferably blended immediately before coating from the viewpoint of storage stability of the coating agent.

  The method for coating the substrate with the curable antifogging coating composition of the present invention is not particularly limited, and is performed by a conventionally known method such as brush coating, spray coating, dip coating, spin coating, curtain coating or the like. In order to develop sufficient anti-fogging effect and good adhesion to the substrate without causing defects such as cracks in the coating film, the coating film is applied so that the dry film thickness is 3 to 30 μm. Is preferred.

  There is no restriction | limiting in particular as a means to harden the said coating film, For example, it can carry out by the conventionally well-known method using natural drying or oven. Although it does not restrict | limit especially as conditions in the case of hardening, It is preferable to make it harden | cure at the temperature of normal temperature (about 20 degreeC)-100 degreeC. When drying at a high temperature for a long time (for example, a drying temperature of 150 ° C. and a drying time of 30 minutes), the anti-fogging effect may be reduced and the coating film may be yellowed.

  The curable antifogging coating agent composition of the present invention can be cured even under mild conditions, while providing a coating film having excellent water resistance and antifogging properties. Moreover, the adhesiveness with base materials, such as various plastics, is also favorable. Furthermore, it is excellent also in water resistance. Therefore, when the curable antifogging coating agent composition of the present invention is coated, for example, on the inner surface of a plastic lens in a vehicular lamp, the film can be formed under mild conditions below the molding processing temperature of the plastic lens, and Energy saving and cost reduction. Furthermore, the excellent anti-fogging effect and the durability of the coating film obtained by the curable anti-fogging coating agent composition of the present invention makes it possible to maintain the illumination brightness and the beauty of the portion for a long period of time.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the following production examples, examples, and comparative examples, “part” means “part by weight”.

Production example (Manufacture of copolymer)
To a reaction vessel equipped with a stirrer, a condenser, a thermometer, a dropping device, a nitrogen introduction tube, and a heating / cooling jacket, 300 parts of toluene was charged, and heated and stirred under a temperature of 85 ° C. in a nitrogen stream. While maintaining the same temperature, 170 parts of N, N′-diethylacrylamide, 5 parts of ethyl acrylate, 25 parts of isocyanatoethyl methacrylate and a polymerization initiator 2,2′-azobisiso A mixture of 4 parts of butyronitrile was added dropwise over 2 hours. Next, after stirring at the same temperature for 3 hours, 0.5 part of 2,2′-azobisisobutyronitrile was added, and further stirred at the same temperature for 2 hours to obtain a colorless and transparent copolymer P-1. A solution was obtained.

  The heating residue of the obtained copolymer P-1 solution (heating residue after drying for 3 hours in a thermostat at 105 ° C .: solid content) was 41.9%, and the viscosity at 23 ° C. was 120 mPa · s. Met.

  A copolymer P-2 solution to a copolymer P-6 solution and a copolymer C- for a comparative example were prepared in the same manner as in the above production method except that the dripping components were changed as shown in Tables 1 and 2. 1 solution to copolymer C-2 solution was obtained. Further, the viscosity (B-type viscometer) of these copolymer solutions was measured in the same manner as described above. The results are shown in Table 1 and Table 2.

In addition, the symbol in Table 1 and Table 2 represents the following meaning.
N-DMAAm = N, N′-dimethylacrylamide (“trade name DMAA” manufactured by Kojin Co., Ltd.),
N-DEAAm = N, N′-diethylacrylamide (“trade name DEAA” manufactured by Kojin Co., Ltd.),
N-iPAAm = N-isopropylacrylamide (“trade name NIPAM” manufactured by Kojin Co., Ltd.),
MMA = methyl methacrylate (special grade reagent manufactured by Wako Pure Chemical Industries, Ltd.)
EA = ethyl acrylate (Wako Pure Chemical Industries, Ltd., reagent first grade product),
MEA = 2-methoxyethyl acrylate (Wako Pure Chemical Industries, Ltd., reagent first grade product),
MOI = isocyanatoethyl methacrylate (“trade name Karenz MOI” manufactured by Showa Denko KK),
AIBN = 2,2′-azobisisobutyronitrile (special grade product manufactured by Wako Pure Chemical Industries, Ltd.).

Examples 1-14 and Comparative Examples 1-3
A curable antifogging coating agent obtained by diluting the copolymer solution produced in the above production example with a mixed solvent of methyl ethyl ketone: n-heptane = 50: 50 so that the solid content of the copolymer is 30% by weight. A curable antifogging coating agent composition in which a surfactant was blended with the composition and the diluted copolymer solution was obtained. The blending composition is shown in Tables 3 to 5. Next, each composition was coated on a substrate using an air spray machine so that the dry film thickness was 5 μm, dried under each condition, and then stored at room temperature for 24 hours as a test piece. did.

In addition, the symbol in Table 3-Table 5 represents the following meaning.
(Surfactant)
SF-1 = polyoxyethylene [n = 2] lauryl ether (HLB = 6.8, “trade name Emulgen 102KG” manufactured by Kao Corporation),
SF-2 = polyoxyethylene [n = 3] lauryl ether (HLB = 8.1, “trade name Emulgen 103” manufactured by Kao Corporation),
SF-3 = polyoxyethylene [n = 8] oleyl ether (HLB = 10.0, “trade name Emulgen 408” manufactured by Kao Corporation),
SF-4 = sodium n-dodecylsulfonate (first grade reagent manufactured by Wako Pure Chemical Industries, Ltd.)
SF-5 = sodium di (2-ethylhexyl) sulfosuccinate (a reagent product manufactured by Tokyo Chemical Industry Co., Ltd.)
SF-6 = polyether-modified silicone (trade name FZ-2105 manufactured by Toray Dow Corning Co., Ltd.).
(Coating substrate)
PC = polycarbonate,
PMMA = polymethyl methacrylate.
(Drying conditions)
Condition-1 = no heat drying,
Condition-2 = 80 ° C. × 30 minutes,
Condition-3 = 150 ° C. × 1 minute.

  Next, the anti-fogging performance and physical properties of each of the coating substrates (test pieces) thus obtained were evaluated according to the evaluation methods shown below. The results are shown in Tables 3-5.

<Dryness of coating film>
A gauze was laid on the coating substrate, a weight of 500 g was placed thereon, and the appearance of the coating film after 1 hour was visually evaluated.
A: No gauze marks are observed.
○: Small irregularities are observed.
Δ: Large irregularities are observed.
X: Gauze is stuck.

<Adhesion>
The peeling of the coating film was visually evaluated according to JIS K 5600-5-6.
○: No peeling at all.
(Triangle | delta): Small peeling is recognized at the intersection of a crosscut part.
X: Large peeling is recognized.

<Water resistance>
After immersing the coating substrate in warm water at 40 ° C. for 240 hours, the appearance of the coating film dried at room temperature was visually evaluated.
○: No change at all.
Δ: Light whitening occurs.
X: A coating film defect such as whitening or peeling occurs.

<Exhalation anti-fogging property>
Exhaled air was sprayed on the coated substrate at room temperature, and the presence or absence of cloudiness generated on the surface was visually evaluated.
A: No cloudiness is observed.
○: Clouding occurs when breathing for 5 seconds or more.
Δ: Cloudiness is observed, but the cloudiness disappears after the end of the exhalation.
X: Cloudiness is recognized.

<Low-temperature breath anti-fogging property>
After storing the coated substrate at 5 ° C. for 1 hour, exhaled air was immediately blown, and the presence or absence of fogging formed on the surface was visually evaluated.
A: No cloudiness is observed.
○: Clouding occurs when exhaling for 5 seconds or more.
Δ: Cloudiness is observed, but the cloudiness disappears after the end of the exhalation.
X: Cloudiness is recognized.

<Steam anti-fogging property>
The coating base material was continuously sprayed with 40 ° C. steam, and the presence or absence of fogging formed on the surface after 1 hour was visually evaluated.
A: No cloudiness is observed, and a flat water film is formed.
○: Clouding is not recognized and large water droplets are formed.
Δ: Cloudiness is observed, but the cloudiness disappears after the completion of the 40 ° C. steam spraying.
X: Cloudiness is recognized.

<Anti-fog durability>
The coating substrate was immersed in warm water at 40 ° C. for 1 hour, dried at room temperature, and sprayed at room temperature for 10 times, and the presence or absence of cloudiness generated on the surface was visually evaluated.
A: No cloudiness is observed.
○: Clouding occurs when breathing for 5 seconds or more.
Δ: Cloudiness is observed, but the cloudiness disappears after the end of the exhalation.
X: Cloudiness is recognized.

Claims (3)

Isocyanatoethyl (meth) acrylate (a), general formula [II];

(Wherein R ³ represents a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms , and R ⁵ represents a linear chain having 1 to 4 carbon atoms. A copolymer obtained by polymerizing an N-substituted alkyl (meth) acrylamide (b) and a (meth) acrylate monomer (c). Is a curable anti-fogging coating agent composition comprising, as an active ingredient, the sum of isocyanatoethyl (meth) acrylate (a) and N-substituted alkyl (meth) acrylamide (b) constituting the copolymer (p) Is a curable antifogging coating agent composition in which is is 50 to 99% by weight and isocyanatoethyl (meth) acrylate (a) is 5 to 30% by weight. 2. The curable antifogging coating composition according to claim 1, further comprising a surfactant, wherein the ratio of the copolymer (p) to the surfactant is 100: 0.1 to 20 in terms of a solid content weight ratio. . The curable antifogging coating composition according to claim 2 , wherein the surfactant is a polyoxyethylene alkyl ether having an HLB of 6 to 11.