WO2023013295A1

WO2023013295A1 - Anti-fog layer and use thereof

Info

Publication number: WO2023013295A1
Application number: PCT/JP2022/025488
Authority: WO
Inventors: 政敬光本; 茂樹森井; 整二大黒
Original assignee: 長瀬産業株式会社
Priority date: 2021-08-02
Filing date: 2022-06-27
Publication date: 2023-02-09
Also published as: JP2023021624A; TWI822201B; TW202313175A; JP7106732B1

Abstract

Provided is an anti-fog layer that uses a water-based solvent and has superior heat resistance. This anti-fog layer includes organic fine particles (A) and has a glass transition temperature of 60°C or greater.

Description

Anti-fog layer and its use

The present invention relates to an anti-fogging layer and its use.

Patent Document 1 describes an antifogging thin film formed from a solution in which a metal alkoxide compound, oxide fine particles having a low equilibrium vapor pressure, and photocatalytically active anatase crystal titania fine particles are dispersed. .

Patent Document 2 describes a water-absorbing anti-fogging member having a fine uneven structure on its surface smaller than the wavelength λ of light to be transmitted.

Patent Document 3 describes an antifogging layer-forming composition containing a copolymer and a hydrolyzate containing specific structural units.

Patent Document 4 describes a coating film containing a metal oxide and polymer particles and having a ten-point average roughness of 5 nm or more and 300 nm or less.

JP-A-10-101374 JP-A-2004-45671 JP 2018-2865 A Patent No. 6483822

The generation of VOCs causes air pollution. Therefore, in 2004, a revised Air Pollution Control Law was issued in Japan, requiring a reduction in the amount of VOCs generated. The paint and ink industry uses large amounts of organic solvents to reduce viscosity during coating operations. Furthermore, of the 700,000 tons of VOC emissions in Japan, the paint industry accounts for about 40% and the ink industry accounts for about 5%. As described above, VOC countermeasures are an issue in the paint and ink industries.

　In paint coating work, various measures are taken to reduce the amount of organic solvents used. For example, there is a shift from organic solvent-based paints to water-based paints.

Solvent-based paints are currently used for anti-fogging paints for headlamps. However, in order to reduce the amount of organic solvent used, it is necessary to switch to a water-based paint. However, anti-fogging paints for headlamps are required to have heat resistance. Until now, no water-based anti-fogging paint could meet the heat resistance standards.

In addition, as in Patent Document 1, the method of forming an antifogging thin film by forming a composition containing a metal alkoxide compound requires baking at about 650°C after coating on a glass substrate. Therefore, the method cannot be used for plastic applications.

Although Patent Document 2 describes an anti-fogging member having a fine uneven structure on the surface as described above, it is actually difficult to form an uneven structure on the surface with a water-absorbing anti-fogging film. .

The composition for forming an antifogging layer described in Patent Document 3 has difficulty in maintaining antifogging properties after a heat resistance test. Furthermore, since an organic solvent is required in the production of the copolymer in the antifogging layer, it is difficult to eliminate the organic solvent and use a water-based paint.

It is difficult for the coating film described in Patent Document 4 to maintain antifogging properties after the heat resistance test.

One aspect of the present invention has been made in view of such circumstances, and an object thereof is to provide an antifogging layer that can be produced using an aqueous solvent and has excellent heat resistance.

In order to solve the above problems, the antifogging layer according to one aspect of the present invention contains organic fine particles (A) and has a glass transition temperature of 60°C or higher.

According to one aspect of the present invention, it is possible to provide an antifogging layer that uses an aqueous solvent and has excellent heat resistance.

FIG. 10 is an AFM (Atomic Force Microscopy) view of the antifogging layer of Example 32;

An embodiment of the present invention will be described in detail below.

As used herein, "(meth)acrylic acid" means either one or both of "acrylic acid" and "methacrylic acid", and "(meth)acrylate copolymer" means "(meth) It means a resin containing acrylic acid and its derivatives as main constituent units. Here, "(meth)acrylic acid" and "derivatives of (meth)acrylic acid" are collectively referred to as "(meth)acrylic monomers", and "derivatives of (meth)acrylic acid" include (meth) ) acrylates ((meth)acrylic acid esters) and (meth)acrylamides.

<Anti-fog layer>
An antifogging layer according to one embodiment of the present invention contains organic fine particles (A) and has a glass transition temperature of 60° C. or higher. The antifogging layer preferably contains organic fine particles (A), a curing agent (B) and a resin (C), and may contain other components.

The heat resistance of the anti-fogging layer is evaluated by the change in the anti-fogging property of the anti-fogging layer due to exposure to heat. The anti-fogging layer contains organic fine particles (A) and is an anti-fogging layer that is less likely to deteriorate in anti-fogging properties due to exposure to heat. For the evaluation method of the heat resistance of the antifogging layer, refer to the description in Examples.

(Glass transition temperature of antifogging layer)
The antifogging layer according to one aspect of the present invention has a glass transition temperature (Tg) of 60° C. or higher, preferably 80° C. or higher, preferably 90° C. or higher, and 100° C. or higher. is more preferably 110° C. or higher, and most preferably 120° C. or higher. Thereby, the heat resistance of the antifogging layer can be enhanced.

In order to increase the glass transition temperature (Tg) of the antifogging layer, the organic fine particles (A) described later should be selected, and the organic fine particles (A) should be added to the curing agent (B) and/or the resin (C). It is preferable to contain a large amount in the layer. The method for evaluating the glass transition temperature of the antifogging layer is evaluated by differential scanning calorimetry (DSC) analysis, which conforms to the method for measuring the glass transition temperature of the organic fine particles (A) described later.

(water contact angle)
The contact angle of water of the antifogging layer according to one aspect of the present invention is preferably 10° or less, more preferably 5° or less. When the antifogging layer has a water contact angle of 10° or less, the antifogging layer can have high antifogging properties. The water contact angle of the antifogging layer can be evaluated using a test piece left at room temperature of 23° C. and a relative humidity of 50%.

(Surface roughness Ra)
The antifogging layer according to one aspect of the present invention preferably has a surface roughness Ra of 5 nm or more and 200 nm or less. According to one aspect of the present invention, since an antifogging layer having excellent antifogging properties can be produced using water, the amount of organic solvent used can be reduced. As a result, the causes of air pollution and the generation of VOCs can be suppressed. Therefore, according to one aspect of the present invention, it is possible to reduce the adverse effects on the atmospheric environment, so it is possible to contribute to Goal 11 of the Sustainable Development Goals (SDGs) led by the United Nations, "Sustainable urban development." It becomes possible.

The surface roughness Ra of the antifogging layer is 5 nm or more, and more preferably 10 nm or more. When the surface roughness Ra of the antifogging layer is 5 nm or more, the specific surface area of the antifogging layer surface can be increased, thereby enhancing the antifogging property of the antifogging layer. In other words, when the surface roughness Ra of the anti-fogging layer is less than 5 nm, the irregularities formed on the surface of the anti-fogging layer become smaller, and as a result, the surface area resulting from the fine irregularities becomes smaller, and the anti-fogging layer becomes thinner. Less water permeates. Therefore, the antifogging property of the antifogging layer is lowered. The surface roughness Ra of the antifogging layer is 200 nm or less, preferably 150 nm or less, more preferably 100 nm or less, even more preferably 70 nm or less, and preferably 50 nm or less. Most preferred. Since the surface roughness Ra of the antifogging layer is finer at 200 nm or less, it prevents the light transmittance of the antifogging layer from decreasing due to the scattering of visible light on the unevenness present on the surface of the antifogging layer. can. Therefore, the light transmittance of the antifogging layer can be enhanced. That is, the antifogging layer has a surface roughness Ra of 5 nm or more and 200 nm or less, so that it can have both high antifogging properties and high light transmittance.

The "arithmetic mean roughness Ra" defined in JIS-B-0601:2013 is adopted for the "surface roughness Ra" of the antifogging layer. A surface roughness measuring instrument [manufactured by Kosaka Laboratory Ltd., model name Surfcorer SE500] was used, and the surface roughness Ra was obtained under the conditions of a scanning range of 4 mm and a scanning speed of 0.2 mm/s.

The main component of the anti-fogging layer is the solid content containing the materials contained in the composition for producing the anti-fogging layer and their reaction products. The "solid content" preferably contains the organic fine particles (A), the curing agent (B), and the resin (C). In the antifogging layer, the solid organic fine particles (A) and resin (C) and the curing agent (B) can react with each other to form a reactant in the antifogging layer. In addition, the anti-fogging layer contains, as a solid content, inorganic particles, an absorbent, and others described later in addition to the organic fine particles (A), the curing agent (B), and the resin (C), as long as the effects of the present invention are not impaired. may contain components of

(Organic fine particles (A))
The organic microparticles (A) are resin microparticles having a polar group, and have a glass transition temperature of 60° C. or higher, preferably 80° C. or higher, preferably 90° C. or higher, and 100° C. or higher. is more preferably 110° C. or higher, and most preferably 120° C. or higher. The organic fine particles (A) are contained in the antifogging layer while maintaining the shape of the particles, and have a glass transition temperature of 60° C. or higher, so that the particles retain their shape even when the antifogging layer is heated. It can be included in the antifogging layer while maintaining the Thereby, for example, even if it is exposed to heat of 80° C. for a long time, the desired surface roughness Ra of the antifogging layer can be maintained. The resin constituting the organic fine particles (A) is not particularly limited as long as it has a glass transition temperature of 250° C. or less. The content of the organic fine particles (A) in the antifogging layer may be 58% by mass or more, preferably 65% by mass or more, and preferably 75% by mass, based on the total amount of solids contained in the antifogging layer as 100% by mass. % or more, and most preferably 80 mass % or more. By increasing the content of the organic fine particles (A) in the antifogging layer within the range of 58 to 99% by mass, the surface roughness Ra of the antifogging layer can be increased, thereby improving the antifogging effect. can enhance sexuality. In addition, the heat resistance of the antifogging layer can be further enhanced by containing a larger amount of the organic fine particles (A) having a glass transition temperature of 60° C. or higher within the range of 58 to 99% by mass. In addition, when the content of the organic fine particles (A) in the antifogging layer is smaller within the range of 99% by mass, the coating strength of the antifogging layer can be further increased. Therefore, if the amount is less than 99% by mass, the component that binds the organic fine particles (A) together can be increased, and the antifogging layer can be preferably formed. The content of the organic fine particles (A) in the antifogging layer means the content as a solid content that does not substantially contain a dispersion medium.

The organic fine particles (A) should be selected based on the glass transition temperature (Tg), the particle diameter D50, and the average SP value of the monomers contained as structural units in the resin of the organic fine particles (A).

The glass transition temperature of the organic fine particles (A) can be obtained from a DSC curve evaluated according to JIS-K-7122:2012 by differential scanning calorimetry (DSC) analysis. The temperature scanning range for obtaining the DSC curve and the evaluation conditions such as the temperature scanning speed are described in detail in Examples, so please refer to them.

Also, the glass transition temperature of the organic fine particles (A) may be roughly calculated as the average value of the glass transition temperatures of the homopolymers of the monomers contained as structural units in the organic fine particles (A). The glass transition temperature of the organic fine particles (A) is obtained by multiplying, for each monomer, the glass transition temperature of the homopolymer of the monomer and the mass ratio (% by mass) of each monomer contained in the resin as a structural unit. It is approximated as the sum of the values obtained by Here, the glass transition temperature of the homopolymer may refer to the value calculated by the Fox formula described in the Polymer Handbook [Polymer Hand Book (J. Brandrup, Interscience 1989)]. The glass transition temperature of the homopolymer, which is about 100,000, may be obtained from the DSC curve according to JIS-K-7122:2012, similarly to the method for measuring the glass transition temperature of the organic fine particles (A) described above. The organic fine particles (A) can increase the glass transition temperature of the organic fine particles (A) by containing a large number of monomers having a higher homopolymer glass transition temperature as structural units, thereby forming an antifogging layer. can increase the heat resistance of From the viewpoint of increasing the glass transition temperature of the organic fine particles (A), the homopolymer of the monomer contained as a structural unit in the organic fine particles (A) may have a glass transition temperature of 60° C. or higher, and may be 80° C. or higher. The temperature is preferably 90° C. or higher, more preferably 100° C. or higher, still more preferably 110° C. or higher, and most preferably 120° C. or higher. Further, although not limited, the glass transition temperature of the homopolymer of the monomer contained as a structural unit in the organic fine particles (A) may be 250° C. or lower. Examples of (meth)acrylamide-based monomers having a high homopolymer glass transition temperature include acrylamide (homopolymer Tg: 153°C) and acryloylmorpholine (homopolymer Tg: 145°C). From the viewpoint of increasing the glass transition temperature of the organic fine particles (A), the organic fine particles (A) contain structural units derived from a monomer having a glass transition temperature of 60° C. or higher in the homopolymer. It is preferably contained in an amount of 60% by mass or more, more preferably 80% by mass or more, based on 100% by mass of the constituting copolymer. In addition, although not limited thereto, the organic fine particles (A) contain 60% by mass or more of structural units derived from a monomer having a high glass transition temperature of 80° C. or higher in a homopolymer, and the glass in the homopolymer The constituent unit derived from a monomer having a transition temperature lower than 80° C. is 40% by mass or less relative to 100% by mass of the copolymer constituting the organic fine particle (A), thereby forming the glass of the organic fine particle (A). The transition temperature may be increased. For example, from the viewpoint of enhancing the dispersion stability of the organic fine particles (A) themselves in an aqueous system, the organic fine particles (A) contain structural units derived from a monomer having a polyethylene glycol chain such as methoxypolyethylene glycol methacrylate. preferably. However, structural units derived from monomers such as methoxypolyethylene glycol methacrylate have a low homopolymer glass transition temperature. For this reason, it may also contribute to lowering the heat resistance of the organic fine particles (A), and as a result, there is a tendency for the antifogging property after being exposed to heat to be lower. In the organic fine particles (A), from the viewpoint of preventing deterioration of the antifogging property due to heat, the constituent units of the homopolymer having a low glass transition temperature are contained in the organic fine particles (A), and the total amount of the constituent units is 100% by mass. , 40% by mass or less. The glass transition temperature of the structural unit of the homopolymer having a low glass transition temperature may be −40° C. or lower, preferably 0° C. or lower, more preferably 40° C. or lower, and lower than 80° C. is most preferred.

(Particle size (D50))
The organic fine particles (A) can adjust the surface roughness Ra of the antifogging layer by the particle diameter thereof. Here, the particle diameter D50 of the organic fine particles (A) is a particle diameter corresponding to cumulative 50% on a volume basis, and the particle diameter D50 is sometimes referred to as a median particle diameter or a median diameter. The volume-based particle diameter D50 is preferably determined by a laser diffraction method using a dynamic light scattering particle size distribution analyzer or the like.

The particle diameter D50 of the organic fine particles (A) is preferably 5 nm or more and 200 nm or less, more preferably 10 nm or more and 150 nm or less, and 15 nm or more and 100 nm or less. is more preferred. The surface roughness Ra of the antifogging layer can be further increased by the unevenness caused by the organic fine particles (A) having a larger particle diameter D50 within the range of 5 nm to 200 nm. That is, the organic fine particles (A) can make the surface roughness Ra of the antifogging layer within the range of 5 nm or more and 200 nm or less. That is, the organic fine particles (A) can provide the antifogging layer with a surface roughness Ra of 5 nm or more and 200 nm or less. Therefore, the antifogging property of the antifogging layer can be enhanced. Further, by using the organic fine particles (A) having a smaller particle diameter D50 within the range of 5 nm or more and 200 nm or less, the light transmittance of the antifogging layer can be further enhanced.

(SP value)
The average value of the SP values of the monomers contained as structural units in the resin constituting the organic fine particles (A) is the mass ratio of each monomer contained in the resin as a structural unit ( (% by mass)). The SP value of each monomer is determined by the following formula (1) based on the Fedors calculation method (see "Polymer Engineering and Science", Vol. 14, No. 2 (1974), pp. 148-154). be able to.

In formula (1), δ is the solubility parameter (SP value), Σ _i Δei is the molar evaporation energy of the monomer (cal/mol), and Σ _i Δvi is the molar volume of the monomer (cm ³ /mol). The unit of the solubility parameter obtained from the above formula (1) is (cal/cm ³ ) ^1/2 , and in this specification, 2.0455×(cal/cm ³ ) ^1/2 = (J/cm ³ ) Assuming that ^1/2 = MPa ^1/2 , MPa ^1/2 is adopted as the unit of the SP value. The hydrophilicity of the organic fine particles (A) can be confirmed using the average SP value of the monomers contained as structural units in the organic fine particles (A) as an indicator.

The average SP value of each monomer contained as a structural unit in the organic fine particles (A) can be 21 MPa ^1/2 or more, preferably 24 MPa ^1/2 or more, and is 26 MPa ^1/2 or more. is preferred, and 27 MPa ^1/2 or more is more preferred. Further, the organic fine particles (A) preferably have an SP value of 32 MPa ^1/2 or less. From the viewpoint of making the SP value of water (47.9) closer to the SP value of water (47.9) in order to increase the hydrophilicity of the organic fine particles (A), the average SP value of the monomer should be higher with a lower limit of 21 MPa ^1/2 . preferable. Moreover, the SP value of the monomer obtained from the formula (1) is not limited as long as it is close to the SP value of water (47.9 MPa ^1/2 ), but it can be 32 MPa ^1/2 or less.

A monomer contained as a structural unit in the resin may be a (meth)acrylic monomer, and the (meth)acrylic monomer includes, for example, a (meth)acrylamide monomer, a (meth)acrylate and (meth)acrylic acid-based monomers, and may contain other monomers described later. (Meth) acrylic monomers such as (meth) acrylamide monomers and (meth) acrylate monomers may have a crosslinkable functional group. A crosslinkable functional group other than an unsaturated double bond group such as a vinyl group or a (meth)acryloyl group that contributes to the monomer being included as a structural unit of the resin that constitutes the organic fine particle (A). means.

(Meth)acrylamide-based monomers are preferred as monomers with high SP values. That is, by including a structural unit derived from a (meth)acrylamide-based monomer in the (meth)acrylate copolymer, the SP value of the resin can be increased, and the hydrophilicity of the organic fine particles (A) can be increased. can be done. Examples of (meth)acrylamide-based monomers include acrylamide, acryloylmorpholine, methacrylamide, dialkyl(meth)acrylamides such as dimethylacrylamide, and monoalkyl(meth)acrylamides such as isopropylacrylamide. From the viewpoint of increasing the hydrophilicity of the organic fine particles (A), the structural units derived from the (meth)acrylamide-based monomer are the total structural units derived from the monomers contained in the (meth)acrylate copolymer. Based on 100% by mass, the content is preferably 5 to 100% by mass, more preferably 50 to 95% by mass. The (meth)acrylamide-based monomer may have a crosslinkable functional group, like the (meth)acrylate-based monomer described later.

(Meth) crosslinkable functional groups possessed by acrylamide-based monomers include, for example, N-methylol groups, N-alkoxymethylol groups, N-methylol ether groups and the like, and having such crosslinkable functional groups ( Examples of meth)acrylamide-based monomers include N-methylolacrylamide and N-methylolamethacrylamide.

(Meth)acrylate-based monomers include (meth)acrylate-based monomers having no crosslinkable functional group and (meth)acrylate-based monomers having a crosslinkable functional group. be done. Examples of (meth)acrylate monomers having no crosslinkable functional group include alkyl (meth)acrylates such as butyl methacrylate and ethyl methacrylate; dialkylamino groups such as dimethylaminoethyl acrylate ( meth)acrylate; (meth)acrylate monomers having a structure derived from (poly)alkylene glycol such as methoxyethyl acrylate and methoxydiethylene glycol acrylate. Structural units derived from (meth)acrylate-based monomers having no crosslinkable functional groups in the fine particle resin are, for example, within a range in which the average SP value of the above monomers is 21 MPa ^1/2 or more. should be included in

Examples of the crosslinkable functional group possessed by the (meth)acrylate monomer include a hydroxyl group, a carboxyl group, a mercapto group, a phenol group, an amino group, a silanol group, and a crosslinkable functional group such as an alkoxysilyl group. Examples of (meth)acrylate monomers having crosslinkable functional groups include 2-hydroxyethyl (meth)acrylate.

(Meth)acrylate monomers having crosslinkable functional groups other than unsaturated double bond groups such as vinyl groups and (meth)acryloyl groups are included as structural units in the (meth)acrylate copolymer. When formed, the crosslinkable functional group can react with, for example, a curing agent (B) described later, inorganic particles, or the like. In addition, regarding structural units derived from a (meth)acrylamide-based monomer having an N-methylol group, an N-alkoxymethylol group, or an N-methylol ether group, a dehydration condensation reaction and a dealcoholization condensation reaction are carried out to form organic fine particles (A). It is expected that the surface roughness Ra of the antifogging layer will be easily maintained by cross-linking with and the shape of the organic fine particles (A) will be stabilized. The (meth)acrylic monomer having a crosslinkable functional group is not limited, but the total of structural units derived from the monomers contained in the (meth)acrylate copolymer is 100 mass. %, preferably 1 to 100% by mass, more preferably 5 to 90% by mass.

(Meth)acrylic acid-based monomers include, for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, and the like. The (meth)acrylic acid-based monomer is preferably acrylic acid or methacrylic acid. These (meth)acrylic acid-based monomers may also be monomers capable of reacting with, for example, a curing agent (B) described later, in that they have a carboxyl group as a crosslinkable functional group.

Other monomers include monomers such as acrylonitrile and methacrylonitrile, and vinyl-based monomers such as vinyl acetate, styrene, N-vinylpyrrolidone, and vinylmethyloxazolidinone. Methyloxazolidinone can be a monomer having an oxazolidinone group as a crosslinkable functional group.

Organic fine particles (A) are typically derived from (meth)acrylamide-based monomers, (meth)acrylate-based monomers, and (meth)acrylic acid-based monomers as main structural units. It may be fine particles of a (meth)acrylate copolymer containing a structural unit that The (meth)acrylate copolymer can suitably impart hydrophilicity to the organic fine particles (A) by containing a structural unit derived from a monomer having a high SP value.

The organic fine particles (A) can be obtained from Takamatsu Yushi Co., Ltd., for example, as a powder or a dispersion liquid.

Table 1 below shows examples of representative monomers that can be contained as structural units in the resin of the organic fine particles (A), and the glass transition temperatures and SP values of their homopolymers. From the glass transition temperatures and SP values of the homopolymers of the monomers exemplified in Table 1, it can be confirmed that the (meth)acrylamide-based monomer is preferable in that it has a high glass transition temperature and a high SP value.

(Curing agent (B))
The antifogging layer preferably contains a curing agent (B). As a result, an antifogging layer can be obtained in which the individual particles constituting the organic fine particles (A) are fixed to each other via the curing agent (B) in the layer. Curing agent (B) preferably contains a compound having at least one crosslinkable functional group. The anti-fogging layer may also be a layer formed by a cross-linking reaction product of a compound having a cross-linkable functional group contained in the curing agent (B) and the organic fine particles (A). The curing agent (B) itself may be a compound that undergoes a cross-linking polymerization reaction, but it should cross-link with the cross-linking functional group of the (meth)acrylate-based monomer, which is the structural unit of the organic fine particles (A). is preferably a compound having a functional group capable of The compound contained in the curing agent (B) preferably has at least one, preferably two or more crosslinkable functional groups in its chemical structure. As long as the curing agent (B) has at least one or more crosslinkable functional groups, the compound may be a monomeric compound, an oligomer, or a polymer.

The content of the curing agent (B) is preferably in the range of 1% by mass or more and 30% by mass or less in terms of solid content, assuming that the total solid content of the antifogging layer is 100% by mass. Within this range, the higher the content of the curing agent (B), the higher the film strength of the antifogging layer. Further, in the range of 1% by mass or more and 30% by mass or less, the smaller the amount, the higher the antifogging property can be imparted to the antifogging layer.

The functional group that the compound contained in the curing agent (B) has and is capable of undergoing a cross-linking reaction with the cross-linkable functional group of the organic fine particles (A) is a functional group that cross-links with each other. Synonymous. Examples of crosslinkable functional groups possessed by the curing agent (B) include carbodiimide groups, epoxy groups, isocyanate groups, blocked isocyanate groups, oxazoline groups, hydrazide groups, and aziridine groups. These crosslinkable functional groups are N-methylol groups, N-alkoxymethylol groups, N-methylol ether groups, and hydroxyl groups, silanol groups, alkoxysilyl groups, which the above (meth)acrylate monomers may have, It can preferably react with a crosslinkable functional group such as a carboxyl group, a mercapto group, a phenol group and an amino group.

Although the compound having such a crosslinkable functional group is not limited, it is preferably a water-soluble compound that dissolves in an aqueous system or a water-dispersible compound that disperses in an aqueous system. That is, curing agent (B) is available as an aqueous solution, aqueous dispersion, or emulsion and can be included in the composition for forming the antifogging layer. The curing agent (B) may contain an organic solvent as long as the effects of the present invention are not impaired.

The curing agent (B) includes, for example, a curing agent having a carbodiimide group, such as Carbodilite (registered trademark) (manufactured by Nisshinbo Chemical Co., Ltd.), Carbosista (registered trademark) (manufactured by Teijin Limited), N,N'- Dicyclohexylcarbodiimide (available from Tokyo Chemical Industry Co., Ltd.), N,N'-diisopropylcarbodiimide (available from Fujifilm Wako Pure Chemical Industries, Ltd.), 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide ( available from Fujifilm Wako Pure Chemical Industries, Ltd.), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (available from Fujifilm Wako Pure Chemical Industries, Ltd.), bis(2,6-diisopropylphenyl)carbodiimide (available from Kawaguchi Chemical Industry Co., Ltd.) and the like. Curing agents having an epoxy group include, for example, Denacol (registered trademark) (manufactured by Nagase ChemteX Corporation), water-based epoxy resin jER (registered trademark) series (manufactured by Mitsubishi Chemical Corporation), ADEKA RESIN (registered trademark) EM series ( manufactured by ADEKA Corporation) and the like. Curing agents having a blocked isocyanate group include, for example, Duranate (registered trademark) (manufactured by Asahi Kasei Corporation), Coronate (registered trademark) series (manufactured by Tosoh Corporation), and the like. Curing agents having an oxazoline group include, for example, Epocross (registered trademark) (manufactured by Nippon Shokubai Co., Ltd.), poly(2-ethyl-2-oxazoline) (available from FUJIFILM Wako Pure Chemical Industries, Ltd.), and the like. . Curing agents having a hydrazide group include adipic acid dihydrazide (available from Tokyo Kasei Co., Ltd.), sebacic acid dihydrazide, dodecanediohydrazide, isophthalic acid dihydrazide, and salicylic acid hydrazide (all available from Otsuka Chemical Co., Ltd.). is mentioned. As a curing agent having an aziridine group, Chemitite (registered trademark) (manufactured by Nippon Shokubai Co., Ltd.), trimethylolpropane tris [3-(2-methylaziridin-1-yl) propionate] (available from Nippon Daikei Energy Co., Ltd.) etc.

(Resin (C))
The antifogging layer preferably contains a resin (C) in addition to the organic fine particles (A) and the curing agent (B) described above. Since the antifogging layer contains the resin (C), the resin (C) and the curing agent (B) can be reacted to form a stronger coating. In addition, by including the resin (C), the adhesion to the substrate can be enhanced.

That is, the resin (C) preferably has a crosslinkable functional group so as to react with at least the curing agent (B). Among them, the crosslinkable functional group is, for example, an acid group such as a carboxyl group, a hydroxyl group, a phenol group, an amino group, or the like, from the viewpoint that the water solubility or water dispersibility of the resin (C) itself can be improved. It is more preferable to have Examples of the resin (C) include polyester resins, polycarbonate-based urethane resins, epoxy ester resins, alkyd resins, water-soluble phenol resins, and the like. It can be an emulsion. The anti-fogging layer can be suitably prepared as an aqueous coating agent by containing the resin (C).

When the resin (C) has an acid group such as a carboxyl group, the acid value of the resin (C) is preferably in the range of 1 to 200 mgKOH/g, more preferably 2 to 60 mgKOH/g. preferable. Accordingly, within the range of the acid value, the higher the acid value, the higher the water solubility of the resin (C) and the higher the heat resistance of the antifogging layer. Further, the higher the acid value, the more the composition described below can be made into an aqueous solvent-based composition. In addition, the lower the acid value, the higher the water resistance of the antifogging layer containing the resin (C).

When the resin (C) has hydroxyl groups, the hydroxyl value of the resin (C) is preferably in the range of 1 to 200 mgKOH/g, preferably 2 to 120 mgKOH/g. Accordingly, within the range of the hydroxyl value, the higher the hydroxyl value, the higher the water solubility of the resin (C) and the higher the heat resistance of the antifogging layer. Moreover, the higher the hydroxyl value, the more the composition described later can be made into an aqueous solvent-based composition. In addition, the lower the hydroxyl value, the higher the water resistance of the antifogging layer containing the resin (C).

In addition, when the resin (C) is a resin having a phenol group or an amino group, as with the resin (C) having a carboxyl group and a hydroxyl group, the water solubility of the resin (C) and the heat resistance of the antifogging layer to be produced are , and the water resistance of the antifogging layer, the amount of phenol groups or amino groups in the resin (C) may be designed.

The resin (C) preferably has a glass transition temperature of 20°C or higher, more preferably 50°C or higher. Thereby, the heat resistance of the antifogging layer can be further enhanced.

The compounding ratio of the curing agent (B) and the resin (C) is such that the cured product of the curing agent (B) and the resin (C) has a high glass transition temperature. For example, an appropriate compounding ratio may be determined from the acid value and/or the hydroxyl value.

The antifogging layer is contained in the antifogging layer such that the total amount of the curing agent (B) and the resin (C) is 2% by mass or more and 43% by mass or less in terms of the solid content contained in the antifogging layer. Within this range, the smaller the amount, the better the heat resistance of the antifogging layer. The total content of the curing agent (B) and the resin (C) in the antifogging layer is preferably 43% by mass or less, more preferably 20% by mass or less in terms of solid content. Moreover, when the total content of the curing agent (B) and the resin (C) in the antifogging layer is 2% by mass or more, the film strength of the antifogging layer can be increased.

For example, the resin (C) is obtained as an aqueous solution, aqueous dispersion, or emulsion, and can be included in the composition described below.

Examples of the resin (C) include polyester resins such as Pes resin series (manufactured by Takamatsu Yushi Co., Ltd.) and Aronmelt (registered trademark) PES-1000, 2000 series (manufactured by Toa Gosei Co., Ltd.). Examples of water-based phenolic resins include Phenolite (registered trademark) TD-4304 (manufactured by DIC Corporation). Polycarbonate-based urethane resins include Hydran (registered trademark) (manufactured by DIC Corporation), epoxy ester resins, and alkyd resins such as Watersol (registered trademark) (manufactured by DIC Corporation).

(Inorganic particles)
The antifogging layer may contain inorganic particles as another component. The inorganic particles contained in the antifogging layer are preferably, for example, alumina, silica, zirconia, titania, zinc oxide, other metal oxide fine particles, carbon, etc. Alumina sol, colloidal silica, silica sol, zirconia sol, titania sol, other metal They are available as colloidal particles such as sols of fine oxide particles. The colloidal particles can be acidic sols, alkaline sols, or neutral stabilized sols. The inorganic particles can be crosslinked with the curing agent (B) and/or the resin (C) described above, and the inorganic particles can also be crosslinked with each other.

The inorganic particles may have a volume-based particle diameter D50 of 2 nm or more, preferably 3 nm or more. This can prevent the surface roughness of the antifogging layer from being damaged. Further, the inorganic particles preferably have a particle diameter D50 of 200 nm or less from the viewpoint of imparting high light transmittance to the antifogging layer.

The content of the inorganic particles is, for example, preferably in the range of 0.1% by mass or more and 10.0% by mass or less when the total amount of solids contained in the antifogging layer is 100% by mass. When the content of the inorganic particles is 10.0% by mass or less, it is possible to suitably prevent deterioration of the antifogging properties due to the inorganic particles. In addition, when the content of the inorganic particles is set to 0.1% by mass or more, the anti-fogging layer has the effect of imparting heat resistance as high light transmittance.

The inorganic particles may be obtained as powder, dispersion, or sol, and may contain an organic solvent such as alcohol to the extent that the effects of the present invention are not impaired. Examples of such inorganic particles include Aluminasol 10A (manufactured by Kawaken Fine Chemicals Co., Ltd.), and colloidal silica such as Snowtech (registered trademark) series (manufactured by Nissan Chemical Industries, Ltd.).

(other ingredients)
The anti-fogging layer may contain an absorbent, a film-increasing aid, and an anti-freezing agent as other components.

Absorbents include, for example, mixed layer clay. The mixed bed clay may preferably be an industrially synthesized synthetic clay, such as smectite, bentonite, montmorillonite, and the like. By adding an absorbent, the function of absorbing and retaining water in the antifogging layer can be added, and the antifogging performance can be enhanced. These mixed bed clays may be included in the compositions described below as anti-settling agents and/or viscosity modifiers, in addition to being absorbents.

Although the mixed layer clay is not limited, for example, it is preferable to use one with a particle diameter D50 of 200 nm or less in the long axis. The content of the mixed layer clay may be appropriately designed within a range that does not impair the effects of the present invention. It is preferably in the range of mass % or less.

Mixed layer clay minerals include, for example, smectites such as Sumecton (registered trademark) and Kunipia (registered trademark) (both manufactured by Kunimine Industries Co., Ltd.).

The film-increasing aid includes water-soluble organic solvents having a boiling point higher than that of water, such as butyl cellosolve (ethylene glycol-monobutyl ether), texanol (2,2,4-trimethylpentane-1,3-diol monoisobutyrate) and other organic solvents. Also, the antifreeze agent is typically ethylene glycol. A water-soluble organic solvent refers to an organic solvent that dissolves in water at room temperature (23° C.) at a concentration of at least 4.0% by mass. The film-increasing aid and the antifreezing agent are also organic solvents, and the content of the film-increasing aid in the antifogging layer is preferably 4.0% by mass or less, preferably 2% by mass or less, and 0 It is preferably 0.5% by mass or less, more preferably 0.1% by mass or less. In addition, by making it 4.0 mass % or less, it is possible to prevent the heat resistance of the anti-fogging layer from being impaired, in other words, the deterioration of the anti-fogging property due to exposure to heat. Further, by making the content 4.0% by mass or less, the organic fine particles (A) themselves can be prevented from being dissolved by the organic solvent, and the surface roughness Ra of the antifogging layer can be maintained. This is expected to prevent deterioration of antifogging properties caused by surface roughness.

Other components of the antifogging layer include surfactants such as leveling agents, antifoaming agents, dispersants, and emulsifiers, viscosity modifiers, antioxidants, UV absorbers, plasticizers, and preservatives. , an antifungal agent, and a water-resistant agent. Some of these surfactants and additives may be included as solids in the composition for making the antifogging layer. The anti-fogging layer may contain coloring agents such as coloring pigments and dyes in order to impart a beautiful appearance to the substrate within a range that does not impair the effects of the present invention. The antifogging layer may contain, for example, a pH adjuster, a pH buffering agent, etc. derived from the composition for producing the antifogging layer.

〔substrate〕
A substrate according to one aspect of the present invention comprises a substrate layer (a) and an antifogging layer (b), wherein the antifogging layer (b) is disposed on the substrate layer (a). The antifogging layer (b) is the antifogging layer according to one aspect of the present invention described above. The description of the antifogging layer (b) conforms to the description of the antifogging layer according to one aspect of the present invention, and the same description will not be repeated.

The substrate layer (a) is a layer for placing the antifogging layer (b) thereon. The material of the substrate layer (a) can be appropriately selected according to the use of the substrate. Examples of the substrate layer (a) include glass, resin materials, metals, ceramics, and the like, and composite materials thereof may also be used. Among them, a plastic having optical transparency is more preferable. Examples of plastics having optical transparency include molding polycarbonate resins, acrylic resins, polyester resins, polystyrene resins, ABS resins, polyvinyl chloride resins, polyamide resins, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), Polycyclohexylene dimethylene terephthalate copolyester resin (Tritan (registered trademark): manufactured by Eastman Chemical Company) and the like.

The shape of the substrate layer (a) is not limited as long as the substrate according to one aspect of the present invention is provided with the antifogging layer (b). That is, the substrate according to one aspect of the present invention can be a substrate molded into a desired shape depending on the application. The substrate may be, for example, a light-transmitting substrate that constitutes a part of a vehicle such as a passenger car, a lighting device such as a headlamp or a tail lamp in a ship, an aircraft, or the like, or a spectacle lens.

The method of arranging the antifogging layer (b) on the substrate layer (a) is not particularly limited. For example, after applying a composition for producing the antifogging layer (b) onto the substrate layer (a), the composition may be cured. The method for curing the composition may be appropriately selected according to the components of the composition, and for example, the composition may be cured by drying by heating.

For example, in the substrate layer (a), the surface on which the antifogging layer (b) is formed is subjected to a surface treatment to improve the wettability and/or adhesion of the antifogging layer (b). good too. Surface treatments include, for example, corona discharge treatment, chemical conversion treatment, plasma treatment, acid and alkaline solution treatment, and the like. Further, the surface of the substrate layer (a) on which the antifogging layer (b) is formed may be coated with a surface treatment agent such as a primer and a coupling agent.
A known method can be adopted as a method for applying the composition according to one aspect of the present invention. For example, the application method includes a spray coating method, a dip coating method, a roll coating method, a bar coater method, and the like. mentioned.

In addition, drying and curing after applying the composition according to one aspect of the present invention may be appropriately designed according to the type of the curing agent (B) or the resin (C), and is not limited. , 60° C. or higher, preferably 100° C. or higher. In the composition according to one aspect of the present invention, the organic fine particles (A) contained in the composition have a high glass transition temperature, so that the aqueous solvent is sufficiently dried and the curing agent (B) is sufficiently cross-linked. One of the advantages is that it is possible to prevent deterioration of the antifogging property due to heating of the antifogging layer while promoting the antifogging property.

In the preparation of the antifogging layer, the application and drying of the composition according to one aspect of the present invention, and the heating may be performed once, or may be repeated multiple times so as to obtain the desired film thickness. Alternatively, the antifogging layer may be produced by repeating the application and drying of the composition according to one aspect of the present invention a plurality of times and heating once.

The film thickness of the composition according to one aspect of the present invention after coating and drying, that is, the film thickness of the antifogging layer is preferably, for example, 20 nm to 10000 nm on the surface of the substrate. When the film thickness of the antifogging layer is 20 nm or more, suitable antifogging properties can be imparted to the substrate covered with the antifogging layer. Further, when the film thickness of the antifogging layer is 10000 nm or less, high light transmittance can be imparted to the antifogging layer.

〔Composition〕
A composition for producing an antifogging layer according to one aspect of the present invention (hereinafter simply referred to as "the composition according to one aspect of the present invention") contains organic fine particles (A) and water, The glass transition temperature of the organic fine particles (A) is preferably 60° C. or higher. That is, the composition, the organic fine particles (A) may be a water-based composition. The description of the configuration of the composition according to one aspect of the present invention (including the description of the components described below) conforms to the description regarding the antifogging layer according to one aspect of the present invention, and the same description will not be repeated. By using the composition according to one aspect of the present invention, the antifogging layer according to one aspect of the present invention can be suitably produced.

The composition according to one aspect of the present invention more preferably contains a curing agent (B). Moreover, the content of the curing agent (B) is more preferably 1% by mass or more and 30% by mass or less in terms of solid content. By setting the content of the curing agent (B) to 1% by mass or more, an antifogging layer having good heat resistance can be obtained, and by setting the content of the curing agent (B) to 30% by mass or less, sufficient strength can be obtained. of antifogging layer can be obtained.

The composition according to one aspect of the present invention preferably further contains a curing agent (B) and a resin (C). Further, it is more preferable that the total amount of the curing agent (B) and the resin (C) is 2% by mass or more and 43% by mass or less in terms of solid content. By setting the total amount of the curing agent (B) and the resin (C) to 2% by mass or more, the adhesion of the antifogging layer to the substrate is obtained, and the total amount of the curing agent (B) and the resin (C) is 43% by mass. % or less, a surface roughness for enhancing the antifogging property of the antifogging layer can be obtained.

Further, in the composition according to one aspect of the present invention, the content of the organic fine particles (A) is more preferably 58% by mass or more and 99% by mass or less in terms of solid content. This is for suitably producing the antifogging layer according to one aspect of the present invention.

Further, in the composition according to one aspect of the present invention, it is more preferable that the content of the organic solvent is less than 4.0% by mass relative to the solid content. According to the composition according to one aspect of the present invention, an antifogging layer having excellent antifogging properties can be produced using water, so that the amount of organic solvent used can be reduced. Examples of the organic solvent include water-soluble organic solvents having a boiling point higher than that of water, which are used as film-increasing aids or freezing agents.

The composition according to one aspect of the present invention, as a composition for producing an antifogging layer, preferably contains 30 to 50000 parts by mass of water as a solvent with a total solid content of 100 parts by mass. This makes it possible to obtain a composition (coating agent) for producing an antifogging layer that can suitably exhibit antifogging properties of the organic fine particles (A). Water as a solvent can be, for example, deionized water, distilled water, tap water, industrial water, and the like. In this specification, the term “solid content” is distinguished from water that evaporates from the composition and volatile solvents, and is included as a composition in the antifogging layer produced using the composition according to one aspect of the present invention. A component need not necessarily be "solid".

Further, by coating and curing the composition according to one aspect of the present invention, an anti-fogging layer containing organic fine particles (A) and having a surface roughness Ra of 5 nm or more and 200 nm or less is produced. A method of manufacturing a cloudy layer is also within the scope of the present invention. Thus, by using the composition according to one aspect of the present invention, the antifogging layer according to one aspect of the present invention can be suitably produced. The substrate to which the composition is applied may be appropriately selected according to the purpose of the antifogging layer.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in the embodiments It is included in the technical scope of the present invention.

〔summary〕
The antifogging layer according to aspect 1 of the present invention contains organic fine particles (A) and has a glass transition temperature (Tg) of 60° C. or higher.

In the antifogging layer according to aspect 2 of the present invention, in aspect 1, it is preferable that the content of the organic fine particles (A) is 58% by mass or more and 99% by mass or less in terms of solid content.

In the

aspect

1 or 2, the anti-fogging layer according to aspect 3 of the present invention preferably has a water contact angle of less than 10°.

In the antifogging layer according to aspect 4 of the present invention, in any one of aspects 1 to 3, the glass transition temperature of the organic fine particles (A) is preferably 60°C or higher.

The antifogging layer according to aspect 5 of the present invention, in any one of aspects 1 to 4, preferably has a surface roughness Ra of 5 nm or more and 200 nm or less.

A substrate according to aspect 6 of the present invention comprises a substrate layer (a) and an antifogging layer (b), wherein the antifogging layer (b) is the antifogging layer according to any one of aspects 1 to 5. layer and is disposed on said substrate layer (a).

In the substrate according to aspect 7 of the present invention, in aspect 6, it is preferable that the substrate layer (a) is a plastic having optical transparency.

A composition according to aspect 8 of the present invention is a composition for producing an antifogging layer according to any one of aspects 1 to 5, comprising organic fine particles (A) and water.

The composition according to aspect 9 of the present invention, in aspect 8, preferably has an organic solvent content of less than 4.0% by mass relative to the solid content of the antifogging layer.

In the composition according to aspect 10 of the present invention, in aspect 8 or 9, the organic fine particles (A) are a (meth)acrylate copolymer, and the (meth)acrylate copolymer is a monomer mixture. It is preferably a copolymer obtained by polymerization.

The composition according to aspect 11 of the present invention, in any one of aspects 8 to 10, further comprises a resin (C), and the resin (C) is a water-soluble resin, a water-dispersible resin, and a resin emulsion. is preferably selected.

An embodiment of the present invention will be described below.

The coating agents of Examples 1-37 and the coating agents of Comparative Examples 1-4 were prepared, and the anti-fogging layers produced from these coating agents were evaluated.

The materials used to prepare each coating agent are as follows.

〔material〕
(organic fine particles)
It was obtained as an aqueous dispersion of 20% by mass of (meth)acrylate copolymer fine particles (manufactured by Takamatsu Yushi Co., Ltd.). Tables 2 and 3 below show the monomers constituting the (meth)acrylate copolymers used in Examples and Comparative Examples.

(Inorganic particles)
Alumina sol: Alumina sol 10A (solid content 10% by mass, manufactured by Kawaken Fine Chemicals Co., Ltd.)
Colloidal silica: Snowtex (registered trademark) OXS (solid content 10% by mass, manufactured by Nissan Chemical Co., Ltd.)
(Organic fine particles: resin (C))
Polyester resin:
Pesresin A-640; manufactured by Takamatsu Oil Co., Ltd., solid content 25% Pesresin A-645GH; manufactured by Takamatsu Oil Co., Ltd., solid content 30% Polycarbonate-based urethane resin:
Hydran (registered trademark) WLS-210; manufactured by DIC Corporation, epoxy ester resin with a solid content of 35%:
Watersol (registered trademark) EFD-5560; manufactured by DIC Corporation, alkyd resin with a solid content of 40%:
Water Sol (registered trademark) BCD-3100; manufactured by DIC Corporation, solid content 43% water-soluble phenolic resin:
Water-soluble resole PE-602, manufactured by DIC Corporation, solid content 42% product (absorbent)
Synthetic smectite: Sumecton (registered trademark) SA (Kunimine Industries Co., Ltd.)
(curing agent)
Carbodiimide: Carbodilite (registered trademark) E-02 (manufactured by Nisshinbo Chemical Inc.)
Aziridine: Chemitite (registered trademark) DZ-22E (Nippon Shokubai Co., Ltd.)
Adipic acid dihydrazide (manufactured by Tokyo Chemical Industry Co., Ltd.)
Epoxy compound: Denacol (registered trademark) EX-810
(manufactured by Nagase ChemteX Corporation)
Blocked isocyanate: Duranate (registered trademark) WM44-L70G
(manufactured by Asahi Kasei Corporation)
Oxazoline compound: Epocross (registered trademark) WS-700 (manufactured by Nippon Shokubai Co., Ltd.)
(Film-forming aid)
Butyl cellosolve: (manufactured by Tokyo Chemical Industry Co., Ltd.)

[Preparation]
The coating of Example 1 was prepared by the following procedure. First, 500 g of an aqueous dispersion of (meth)acrylate copolymer fine particles was prepared, and 20 g of an aqueous dispersion of a polyester resin was added to the aqueous dispersion. Next, 10 g of an aqueous dispersion of alumina sol and 10 g of carbodiimide in terms of solid content as a curing agent were added to the aqueous dispersion of the (meth)acrylate copolymer fine particles. Thereafter, the aqueous dispersion was stirred, and aqueous ammonia (1 mol/L) was added to adjust the pH to 8.0, thereby obtaining a coating agent of Example 1. Coating agents of Examples 2 to 37 and Comparative Examples 1 to 4 were prepared in the same manner as the coating agent of Example 1 according to the compositions shown in Tables 2 and 3 below.

[Production of anti-fogging layer]
Using bar coater #2, the coating agent of Example 1 was applied to a polycarbonate test piece (thickness: 2 mm). Then, the coating agent was dried and cured by heating the test piece coated with the coating agent at a temperature of 90° C. for 20 minutes. As a result, a test piece having an antifogging layer with a thickness of about 1 μm was produced. Test pieces with antifogging layers of Examples 2 to 37 and Comparative Examples 1 to 4 were prepared according to the same procedure as the preparation of the antifogging layer from the coating agent of Example 1.

[Each evaluation]
Using the test pieces provided with the antifogging layers of Examples 1 to 37 and Comparative Examples 1 to 4, the following evaluations were performed. Evaluation results are shown in Tables 4 and 5.

(Particle size)
The particle diameter (unit: nm) of the organic fine particles was evaluated as the particle diameter corresponding to cumulative 50% on a volume basis. The particle size of the organic fine particles was measured with a dynamic light scattering particle size distribution analyzer (device name: Nanotrac Wave II UT151, manufactured by Microtrac Bell). Nanotrac is a registered trademark of the company.

(Glass transition temperature (Tg) of organic fine particles)
The glass transition temperature (Tg) of the organic fine particles was measured using DSC (differential scanning calorimetry, device name: EXSTAR DSC6200, manufactured by Seiko Instruments Inc.). The glass transition temperature (Tg) of the organic fine particles was obtained by measuring a DSC curve according to JIS-K-7122:2012 and obtaining the DSC curve. The mass of the sample used for DSC measurement was 5 mg. The first scan ramped the temperature range from −10° C. to 300° C. at a rate of 20° C./min, then cooled the sample using liquid nitrogen, followed by a second scan from −10° C. to The temperature range up to 300° C. was heated at a rate of 20° C./min, and the glass transition temperature of the organic fine particles was derived from the DSC curve obtained by the second scan.

(Surface roughness Ra)
The surface roughness Ra of the anti-fogging layer was measured in accordance with JIS-B-0601-2013 using a surface roughness measuring instrument [manufactured by Kosaka Laboratory Ltd., model name Surfcorer SE500], scanning range 4 mm, scanning speed 0. It was obtained under the condition of .2 mm/s.

(Atomic force microscope observation)
Using an AFM (atomic force microscope, device name: Dimension 3100, manufactured by Veeco), the antifogging layer produced from the coating agent of Example 32 was observed with an atomic force microscope. The results are shown in FIG.

(Glass transition temperature (Tg) of antifogging layer)
The glass transition temperature Tg of the antifogging layer was measured by DSC (differential scanning calorimetry, device name: EXSTAR DSC6200, manufactured by Seiko Instruments Inc.). The sample mass of the antifogging layer was 5 mg, and the temperature range, heating rate, and number of scans for obtaining the DSC curve were the same as the conditions for obtaining the DSC curve of the glass transition temperature (Tg) of the organic fine particles. Therefore, the description is omitted.

(water contact angle)
The contact angle of the antifogging layer to water was measured using a contact angle meter (device name: CV-DT A type, manufactured by Kyowa Interface Science Co., Ltd.).

(Paint film transparency)
The coating film transparency (light transmittance) of the test piece provided with the antifogging layer was measured using a haze meter ("HAZE METER NDH5000", manufactured by Nippon Denshoku Industries Co., Ltd.). The HAZE value is measured according to JIS-K7361-1: 1997 under the conditions that the light source is a white LED and the luminous flux is 14 mm. It was evaluated as more preferable. The HAZE value of the 2 mm-thick polycarbonate test piece itself was 0.30.
○: HAZE value was 0.30 or more and less than 0.40.
Δ: The HAZE value was 0.40 or more and less than 0.50.
x: HAZE value was 0.50 or more.

(Anti-fogging property)
In an air-conditioned room at a temperature of 23° C. and a humidity of 50%, breath was blown to the antifogging layer formed on the test piece for 5 seconds, and the antifogging property was evaluated according to the following criteria.
O: Not cloudy at all.
Δ: Slightly cloudy, but quickly recovers.
x: Cloudy.

(Heat-resistant)
Each test piece was allowed to stand for 240 hours under temperature conditions of 80° C., 100° C., and 110° C., and then allowed to stand for 1 hour in a constant temperature chamber air-conditioned at a temperature of 23° C. and a humidity of 50%. After that, antifogging properties and light transmission properties were evaluated.

(gloss value)
The gloss value was measured using a 3-angle surface gloss meter (apparatus name: Micro Trigloss, manufactured by BYK) under the condition of an incident angle of 60°. The gloss value is measured by stacking 10 sheets of A4 copy paper (manufactured by Itochu Pulp & Paper Co., Ltd., whiteness 92%), and setting the test piece on which the antifogging layer of each example and comparative example is prepared. measured in

As shown in Tables 4 and 5, according to the antifogging layer according to one aspect of the present invention, the Tg of the antifogging layer is 60°C or higher, more preferably 110°C or higher, so that after the heat resistance test, It was also shown that the anti-fogging property is excellent.

Claims

An antifogging layer containing organic fine particles (A) and having a glass transition temperature (Tg) of 60°C or higher.
The antifogging layer according to claim 1, wherein the content of the organic fine particles (A) is 58% by mass or more and 99% by mass or less in terms of solid content.
The antifogging layer according to claim 1 or 2, which has a water contact angle of less than 10°.
The antifogging layer according to any one of claims 1 to 3, wherein the organic fine particles (A) have a glass transition temperature of 60°C or higher.
The antifogging layer according to any one of claims 1 to 4, wherein the surface roughness Ra is 5 nm or more and 200 nm or less.
a substrate layer (a);
and an anti-fogging layer (b),
The antifogging layer (b) is the antifogging layer according to any one of claims 1 to 5, and is disposed on the substrate layer (a).
substrate.
The substrate layer (a) is a plastic having optical transparency,
A substrate according to claim 6 .
A composition for making an antifogging layer according to any one of claims 1 to 5,
organic fine particles (A);
including water and
Composition.
The content of the organic solvent is less than 4.0% by mass with respect to the solid content of the antifogging layer.
A composition according to claim 8 .
The organic fine particles (A) are a (meth)acrylate copolymer,
The (meth)acrylate copolymer is a copolymer obtained by polymerizing a monomer mixture,
A composition according to claim 8 or 9.
further comprising a resin (C),
The composition according to any one of claims 8 to 10, wherein said resin (C) is selected from water-soluble resins, water-dispersible resins and resin emulsions.