WO2018221739A1

WO2018221739A1 - Coating composition and method for producing laminated body

Info

Publication number: WO2018221739A1
Application number: PCT/JP2018/021259
Authority: WO
Inventors: 悠五十部; 北川　浩隆
Original assignee: 富士フイルム株式会社
Priority date: 2017-06-02
Filing date: 2018-06-01
Publication date: 2018-12-06
Also published as: JPWO2018221739A1; JP6914330B2

Abstract

According to an aspect of the present invention there is provided a coating composition and a method for producing a laminated body. Said composition comprises: polymer particles; an inorganic oxide precursor; an electrolyte selected from an acid, a base, and a salt; and water. Said coating composition has a pH at 25°C of 4 to 10 and an electric conductivity at 25°C of at least 1 mS/m.

Description

Coating composition and method for producing laminate

The present disclosure relates to a coating composition and a method for producing a laminate.

In recent years, coating compositions for applying and forming a thin layer of several μm to several tens of nanometers by various coating methods are widely used in optical film, printing and photolithography applications. For example, since an aqueous coating solution uses a solvent containing water as a main component, the surface energy of the formed film is low and the transparency is excellent. On the other hand, the coating liquid containing an organic solvent as a main component has advantages such as low viscosity of the coating liquid and low surface tension of the coating liquid, and any of the coating liquids is used in various applications.

Specific applications of these coating liquids include, for example, antireflection films, optical lenses, optical filters, flat films for thin film transistors (TFTs) for various displays, anti-condensation films, antifouling films, surface protective films, etc. Is mentioned. Among these, the antireflection film is useful because it can be applied to protective films for solar cell modules, monitoring cameras, lighting equipment, signs, and the like.

For example, in a solar cell module, the reflection characteristics of the glass (so-called windshield) disposed on the outermost layer on the side on which sunlight is incident greatly affect the power generation efficiency. Various prevention coating solutions have been proposed.

As a technique related to the antireflection film of the solar cell module, for example, a technique related to a silica-based porous film has been proposed.
Specifically, a silica-based porous film having a plurality of pores in a matrix mainly composed of silica, having a refractive index in the range of 1.10 to 1.38, A silica-based porous film containing pores having a diameter of 20 nm or more and having pores having a diameter of 20 nm or more opened on the outermost surface of 13/10 ⁶ nm ² or less is disclosed and has excellent antireflection performance and the like. There is an example (see, for example, JP-A-2016-1199).

In addition to the above, a technique for forming an antifouling coating layer using an ionic surfactant as an aqueous antifouling coating material has been disclosed (see, for example, International Publication No. 2015/012021).
Further, there is a document disclosing preparation of an antireflection film-forming composition using an aqueous nitrate solution and an aqueous maleic acid solution, or preparing an antireflection coating composition using nitric acid (for example, Japanese Patent Application Laid-Open No. 2005-2005). No. 99693 and JP-A-2006-335605).

A technique for forming a film having antireflection performance on a substrate using a coating solution containing a composition for forming a silica-based porous film has been disclosed, as described in JP-A-2016-1199. For example, the coating solution used for forming the antireflection film has a neutral pH (pH = 4) from the viewpoint of corrosion resistance in each step, ease of handling (safety) of the solution, and the like. To 10). However, nitric acid is used in the composition described in Japanese Patent Application Laid-Open No. 2016-1199, as well as Japanese Patent Application Laid-Open No. 2005-99693 and Japanese Patent Application Laid-Open No. 2006-335605. There are many examples in which a strong acid such as nitric acid is used for the coating solution. Such a coating solution is likely to have a low pH, and concerns remain about the corrosion resistance and ease of handling during each step.

In view of the above, it has been found that when a weak acid is used to suppress a decrease in pH, a decrease in pH is suppressed, but there is a problem that thickness unevenness is likely to occur in the coating film.
For example, when a film is formed by a coating method in order to impart a function such as antireflection performance to the surface of glass or the like used in a solar cell module, charging is particularly likely to occur, and unevenness in film thickness is likely to occur due to charging. It was also found out. The film thickness unevenness not only tends to impair the antireflection performance, but also causes an image defect in which bright spots recognized as locally bright parts are scattered (bright spot-like failure), leading to appearance defects.
This phenomenon is found to be particularly prominent when applied to a substrate having a concavo-convex shape for the purpose of imparting antiglare properties to the surface, such as glass used in solar cell modules. It was.

Techniques related to the formation of functional layers such as antireflection films, such as the above-mentioned JP-A-2016-1199, International Publication No. 2015/012021, JP-A-2005-99693, and JP-A-2006-335605 However, it is difficult to avoid the occurrence of bright spot failure in the silica-based porous film disclosed in, for example, Japanese Patent Application Laid-Open No. 2016-1199. In fact, there are many examples in which a composition containing a strong acid is applied as in JP-A-2005-99693 and JP-A-2006-335605.
Moreover, although dissociative ionic surfactants are used as in International Publication No. 2015/012021, for example, when an antireflection layer is formed, good antireflection performance cannot be obtained.
Further, as in JP-A-2005-99693 and JP-A-2006-335605, a composition using a strong acid such as nitric acid as an electrolyte tends to cause a decrease in pH.

The present disclosure has been made in view of the above.
The problem to be solved by an embodiment of the present invention is to provide a coating composition that maintains pH and suppresses the occurrence of bright spot failures.
The problem to be solved by another embodiment of the present invention is to provide a method for producing a laminate in which pH is maintained and generation of bright spot failures is suppressed.

Specific means for achieving the above object includes the following aspects.
<1> Polymer particles, an inorganic oxide precursor, an electrolyte selected from an acid, a base, and a salt, and water, having a pH of 4 to 10 at 25 ° C., and conducting at 25 ° C. The coating composition has a degree of 1 mS / m or more.
<2> The coating composition according to <1>, wherein the electrical conductivity is 5 mS / m to 70 mS / m.
<3> The coating composition according to <1> or <2>, wherein the electrolyte is an ammonium salt.
<4> The inorganic oxide precursor includes at least one compound selected from a hydrolyzable silane compound represented by the following formula (1) and a partial hydrolysis condensate of the hydrolyzable silane compound <1>. The coating composition according to any one of <3>.
Formula (1): R ¹ —Si (OR ² ) ₃
In the formula (1), R ¹ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluorinated alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms, and R ² represents a hydrogen atom An atom or an alkyl group having 1 to 8 carbon atoms is represented.
<5> The application according to <4>, wherein the partially hydrolyzed condensate of the hydrolyzable silane compound includes at least one unit selected from the following formula (2), formula (3), and formula (4): It is a composition.
Formula (2): R ¹ —Si (OR ² ) ₂ O _1/2 unit Formula (3): R ¹ —Si (OR ² ) O _2/2 unit Formula (4): R ¹ —Si—O _{3 / 2} units In the formulas (2), (3) and (4), each R ¹ independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms, R ² each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.

<6> The coating composition according to any one of <1> to <5>, wherein the electrolyte content is 0.001 mol / L to 0.5 mol / L in terms of molar concentration.
<7> The coating composition according to any one of <1> to <6>, which is used for coating formation of a cured film of a laminate having a substrate having a concavo-convex structure on the surface and a cured film.
<8> A step of applying the coating composition according to any one of <1> to <7> on a substrate with a roll coater to form a coating film, a step of drying the coating film, and the drying And a step of obtaining a cured film by baking the coating film that has undergone the step of causing the laminate to be produced.
<9> The method for producing a laminate according to <8>, wherein the average film thickness of the cured film is 80 nm to 200 nm.
<10> The method for producing a laminate according to <8> or <9>, wherein the substrate is a glass substrate.
<11> The substrate is the method for producing a laminate according to any one of <8> to <10>, wherein the surface has an uneven structure.
The <12> roll coater is a method for producing a laminate according to any one of <8> to <11>, wherein the surface material of the roll for applying the coating composition to the surface of the substrate is rubber.

According to one embodiment of the present invention, there is provided a coating composition that is excellent in corrosion resistance in the production process, easy to handle liquid (safety), and can prevent the occurrence of bright spot failure. Moreover, according to other embodiment of this invention, the manufacturing method of the laminated body by which generation | occurrence | production of the bright spot-like failure was suppressed is provided.

FIG. 1 is a laser micrograph of volatile defects.

Hereinafter, the manufacturing method of the coating composition and laminate of the present disclosure will be described in detail.

In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value described in a numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described. Further, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the values shown in the examples.
In the present specification, the amount of each component in the composition is the sum of the plurality of substances present in the composition unless there is a specific indication when there are a plurality of substances corresponding to each component in the composition. Means quantity.

In addition, the term “process” in this specification is not limited to an independent process, and even if it cannot be clearly distinguished from other processes, the term is used as long as the intended purpose of the process is achieved. included.

<Coating composition>
The coating composition of the present disclosure includes polymer particles, an inorganic oxide precursor, an electrolyte selected from an acid, a base, and a salt, and water, and further includes other components as necessary. Also good.
In addition, the coating composition of the present disclosure is prepared so that the pH at 25 ° C. is in the range of 4 to 10, and the conductivity at 25 ° C. is 1 mS / m or more.

For example, as disclosed in Japanese Patent Application Laid-Open No. 2016-1199, a technique for forming a film having antireflection ability on a substrate using a coating liquid containing a composition for forming a silica-based porous film has been conventionally used. A technique that is disclosed and focuses on providing functions such as antireflection is known.
For example, a coating liquid for forming an antireflection film as a silica-based porous film has a pH near neutral (pH = 4) from the viewpoint of corrosion resistance in each step, ease of handling of the liquid (safety), and the like. 10) is preferable, but many compositions using strong acid in the coating solution, such as Japanese Patent Application Laid-Open No. 2016-1199, Japanese Patent Application Laid-Open No. 2005-99693, and Japanese Patent Application Laid-Open No. 2006-335605, are often used. It is done. However, use of a strong acid causes a decrease in pH, and there is concern about corrosion resistance and ease of handling. Thus, it has been found that when a weak acid is simply used to prevent the pH from being lowered, the pH drop can be suppressed, but the coating film has uneven thickness.
When this point was verified, it became clear that the uneven thickness of the coating film was caused by charging the strong acid that was the electrolyte into a weak acid, and the uneven thickness of the coating film was caused by the uneven charging that occurred in the surface. It was. The thickness unevenness of the coating film becomes a factor of reducing the antireflection property in the antireflection film, for example.

For example, in a solar cell module, a base material with a functional layer (for example, a windshield) is mounted, and this windshield has an antireflection layer that suppresses reflection of sunlight on the side on which sunlight enters. . From the viewpoint of obtaining antireflection performance advantageous for improving power generation efficiency, it is important that an antireflective layer disposed on the windshield is formed with a film having an appropriate refractive index with an appropriate film thickness. . In order to apply the antireflection layer easily and uniformly over a wide area, a roll coating method is generally applied.
In the roll coating method, a coating film is formed by transferring the coating composition adhering to the coating roll for applying the coating composition directly to the substrate to the substrate, but friction is generated between the substrate and the coating roll. Charge is likely to occur. When frictional charging occurs, the surface of the substrate is not uniformly charged and uneven charging is likely to be formed. It is considered that the uneven charging tends to cause unevenness in the thickness of the coating film by acting on the coating film before drying. In this case, for example, the antireflection property is maximized when the thickness of the coating film is at a specific value. Therefore, when thickness unevenness occurs, the antireflection property decreases. In addition, as shown in FIG. 1, unevenness in thickness is caused by image defects (bright spot-like faults) in which bright spots recognized as sites that appear locally bright in the plane are scattered, resulting in poor appearance. Become.
The triboelectric charge as described above is likely to occur when the difference in the charge train between the substrate and the coating roll is large. For example, the rubber generally used for the material of the coating roll and the front substrate of the solar cell module, for example. It can be said that the glass to be mounted is in an environment in which frictional charging is likely to occur because of a large difference in charge column.
Furthermore, the windshield mounted on the solar cell module is generally provided with a concavo-convex structure on the surface in order to impart antiglare properties. When it has an uneven structure, the triboelectric charge amount when triboelectric charging occurs tends to be different between the convex part and the concave part. As a result, uneven charging occurs on the surface of the substrate, the thickness of the coating film becomes non-uniform due to the uneven charging, and the functionality such as antireflection properties further decreases.

It is presumed that when the conductivity of the coating composition is increased, an antistatic effect is obtained, so that uneven charging due to frictional charging hardly occurs and the occurrence of uneven coating thickness is also suppressed. For this reason, it is conceivable to use a strong acid having a high degree of ionization as a component for increasing the conductivity of the coating composition. However, as described above, simply using a strong acid leads to a decrease in pH of the coating composition.
On the other hand, it is conceivable to use an ionic surfactant that is an electrolyte as in, for example, International Publication No. 2015/012021, but the ionic surfactant cannot be expected to improve the thickness unevenness of the coating film, and is good. It has been found that a good antireflection performance cannot be obtained.

In the present disclosure, in view of the above, the conductivity is adjusted to 1 mS / m or more by adding a specific electrolyte. As a result, high electrical conductivity that can contribute to antistatic properties and pH near neutrality are compatible, and the occurrence of bright spot failure is suppressed without impairing corrosion resistance and handling properties.
The above effects are particularly effective when an ammonium salt is used as an electrolyte, and further effective when a hydrolyzable silane compound is used as an inorganic oxide precursor.

~ PH ~
The coating composition of the present disclosure has a pH adjusted to 4 to 10 at 25 ° C.
When the pH is in the range of 4 to 10, the concern about corrosion of electronic materials using metals is eliminated, and handling during work in the process (for example, coating or transportation of the coating composition) is easy.
The pH is more preferably in the range of 6 to 8 from the same viewpoint as described above.
The pH is a value measured using a pH meter (model number: HM-31, manufactured by Toa DKK) with the coating composition adjusted to 25 ° C. in a 25 ° C. environment.

~ Conductivity ~
In the coating composition of the present disclosure, the electrical conductivity at 25 ° C. is adjusted to 1 mS / m or more.
When the electrical conductivity is 1 mS / m or more, charging at the time of application can be kept low, and the degree of uneven charging on the substrate can be reduced. Thereby, the coating thickness nonuniformity resulting from charging nonuniformity is suppressed effectively.
The conductivity is more preferably 5 mS / m to 90 mS / m, and further preferably 5 mS / m to 70 mS / m from the above viewpoint.

The electrical conductivity is the reciprocal of the resistivity ρ in the formula when the resistance R between the bottom surfaces of the cylinder in the cylindrical conductor having the length L and the bottom area (cylinder cross-sectional area) A is expressed by the following formula. It is represented by
R = ρ (L / A)
The electrical conductivity measurement in the present disclosure is a value measured at a temperature of 25 ° C. based on the above. Specifically, the electrical conductivity meter (model number: CM-30R, cell: CT-57101B, Toa DKK) Can be measured at 25 ° C.

-Polymer particles-
The coating composition of the present disclosure contains at least one kind of polymer particles.
The polymer particles are particles that can be removed from the coating film formed by the coating composition, and are preferably particles that can be removed from the coating film by heat treatment.
Examples of the particles that can be removed from the coating film by the heat treatment include particles that are removed by at least one of thermal decomposition and volatilization when the heat treatment is performed.

The thermal decomposition temperature of the polymer particles is preferably 300 ° C. to 800 ° C., more preferably 400 ° C. to 700 ° C.
The thermal decomposition temperature means a temperature at which the mass reduction rate reaches 50% by mass in thermal mass / differential heat (TG / TDA) measurement.

Further, the glass transition temperature (Tg) of the polymer particles is preferably 0 ° C. to 150 ° C., more preferably 30 ° C. to 100 ° C.
By making Tg 150 degrees C or less, the antifouling property of the film | membrane obtained improves more. This is considered to be because the uneven distribution of the hydrolyzable silane compound on the film surface becomes easier by increasing the fluidity of the coating composition.
By setting Tg to 0 ° C. or higher, the scratch resistance of the resulting film is further improved. This is considered to be because the thermal decomposition temperature of the polymer particles can be set to 300 ° C. or higher, and pores of a uniform size can be obtained while maintaining the mechanical strength of the film high.
The glass transition temperature is obtained from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, it is described in “Supplemental Method” described in JIS K7121-1987 “Method for Measuring Glass Transition Temperature”. It is determined by “outer glass transition start temperature”.

In the present specification, “antifouling” is evaluated by the tape adhesive remaining property when cellotape (registered trademark) is applied. For example, in the field of solar cell modules, When the windshield is placed, for example, if a resin such as ethylene-vinyl acetate copolymer (EVA) contacts and adheres to an undesired region such as the windshield, it can be easily removed (eg, peeled off, wiped off, etc.). Properties can also be improved.

The polymer contained in the polymer particles is not particularly limited as long as polymer particles having a desired particle diameter can be obtained. The polymer is a single monomer selected from the group consisting of (meth) acrylic acid ester monomers, styrene monomers, diene monomers, imide monomers, and amide monomers (hereinafter also referred to as “specific monomer group”). A polymer or copolymer is preferred.
Moreover, from the viewpoint of the liquid aging stability of the coating composition, the polymer constituting the polymer particles preferably does not contain a functional group that reacts with and condenses with a silanol group such as a hydroxy group and a carboxy group.

(Meth) acrylic acid ester monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic Isobutyl acid, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, nonyl (meth) acrylate, (meth) Decyl acrylate, dodecyl (meth) acrylate, phenyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, (Meth) ethoxypropyl acrylate, diethylaminoethyl (Meth) acrylate, dialkylaminoalkyl (meth) acrylate, glycidyl (meth) acrylate, ethylene glycol diacrylate, diethyl glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, dipropylene Diacrylate of glycol, Diacrylate of tripropylene glycol, Dimethacrylate of ethylene glycol, Dimethacrylate of diethylene glycol, Dimethacrylate of triethylene glycol, Diacrylate of polyethylene glycol, Dimethacrylate of propylene glycol Acid ester, dipropylene glycol dimethacrylate, tripropylene Call dimethacrylate, and the like of.

Styrene monomers include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene, fluorostyrene, chlorostyrene, bromostyrene, Examples thereof include dibromostyrene, chloromethylstyrene, nitrostyrene, acetylstyrene, methoxystyrene, α-methylstyrene, vinyltoluene, sodium p-styrenesulfonate, and the like.

Examples of the diene monomer include butadiene, isoprene, cyclopentadiene, 1,3-pentadiene, dicyclopentadiene, and the like.

Examples of the imide monomer include maleimide, N-methylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide, 6-aminohexylsuccinimide, 2-aminoethylsuccinimide and the like.

Examples of amide monomers include acrylamide derivatives such as acrylamide and N-methylacrylamide, allylamine derivatives such as N, N-dimethylacrylamide and N, N-dimethylaminopropylacrylamide, and aminostyrenes such as N-aminostyrene. Can be mentioned.

The polymer contained in the polymer particles is preferably a polymer having a crosslinked structure in order to obtain dispersibility in a solvent.
The polymer particles having a crosslinked structure can be obtained by polymerizing an emulsifier described later and a crosslinking reactive monomer. Although there is no restriction | limiting in particular in the crosslinking reactive monomer which can be used, For example, what has an unsaturated double bond in a molecule | numerator, what has a radically polymerizable double bond, what has a reactive functional group in a molecule | numerator (Specific examples include carboxy group, hydroxy group, epoxy group, amino group, amide group, maleimide group, sulfonic acid group, phosphoric acid group, isocyanate group, alkoxy group, alkoxysilyl group, etc.) It is selected from one or a combination thereof.

Among these, as the crosslinking reactive monomer, a monomer having a radical polymerizable double bond is preferable, and a (meth) acrylate monomer having a plurality of radical polymerizable double bonds in the molecule, or a styrene-based monomer. Monomers are more preferred.
Examples of the crosslinking reactive monomer include trimethylolpropane triacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, decaethylene glycol dimethacrylate, pentadecaethylene glycol dimethacrylate, and 1,3-butylene dimethacrylate. , Allyl methacrylate, trimethylolpropane trimethacrylate, polyfunctional (meth) acrylates such as pentaerythritol tetraacrylate; aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof; N, N-divinylaniline; divinyl ether; Divinyl sulfide; divinyl sulfonic acid; polybutadiene; polyisoprene unsaturated polyester, etc. And the like.

The polymer particles are preferably nonionic polymer particles from the viewpoint of further improving scratch resistance and antifouling properties. When the coating composition contains nonionic polymer particles, the compatibility between the hydrolyzable silane compound and the nonionic polymer particles is improved, and the nonionic polymer particles are easily dispersed uniformly in the coating composition. As a result, when a film is formed by the coating composition, the distribution of vacancies existing in the film becomes uniform, and in combination with the fact that hydrolyzable silane compounds are unevenly distributed on the film surface, scratch resistance And antifouling property can be improved more.

“Nonionic polymer particles” are polymer particles synthesized by emulsion polymerization using a nonionic emulsifier and containing a structure derived from the nonionic emulsifier in the structure.
Here, the nonionic polymer particle is a polymer particle that contains a structure derived from a nonionic emulsifier in its structure and does not substantially contain a structure derived from an anionic emulsifier or a structure derived from a cationic emulsifier. The term “substantially free” means that the ratio of the structure derived from the nonionic emulsifier is 99% by mass or more with respect to the total amount of the structure derived from the emulsifier.
The ratio of the structure derived from the nonionic emulsifier can be calculated by analyzing fragments of polymer particles by a known method using pyrolysis GC-MS (gas chromatograph mass spectrometry).

The nonionic polymer particles are preferably self-dispersing particles. Self-dispersing particles refer to particles made of water and alcohol-insoluble polymers that can be dispersed in an aqueous medium containing water and alcohol by the hydrophilic portion of the polymer particles themselves. The dispersed state means an emulsified state (emulsion) in which water and an alcohol-insoluble polymer are dispersed in an aqueous medium in a liquid state, and a dispersed state (suspension) in which a water-insoluble polymer is dispersed in an aqueous medium in a solid state. It includes both states.

Also, “water-insoluble” means that the amount dissolved in 100 parts by mass (25 ° C.) of water is 5.0 parts by mass or less.

Since the nonionic polymer particles are self-dispersing particles, the nonionic polymer particles are easily dispersed uniformly in the obtained film. Also, for example, the coating composition does not contain an emulsifier or the content of the emulsifier is applied. Since it can be 1 mass% or less with respect to the total mass of a composition, it is excellent in scratch resistance and antifouling property.

As the nonionic emulsifier for synthesizing nonionic polymer particles, various nonionic emulsifiers can be suitably used. The nonionic emulsifier is preferably a nonionic emulsifier having an ethylene oxide chain, and more preferably a nonionic reactive emulsifier having an ethylene oxide chain having a radical polymerizable double bond in the molecule. Thereby, the film | membrane which has favorable pencil hardness can be obtained. The reason is not clear, but because the emulsion stability during polymerization is good, the dispersion state of the polymer particles in the film is uniform, and the distribution of pores is uniform, resulting in non-uniform distribution of pores. It is considered that the occurrence of local capillary force and cracks resulting from the above is suppressed, and the scratch resistance of the resulting film is improved.

Specific examples of the nonionic emulsifier having an ethylene oxide chain include emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethyleneoxypropylene block copolymer, polyethylene glycol fatty acid ester, and polyoxyethylene sorbitan fatty acid ester. It is done.
Specific examples of reactive emulsifiers include polyethylene glycol mono (meth) acrylates, polyoxyethylene alkylphenol ether (meth) acrylates, polyoxyethylene glycol monomaleate esters having various molecular weights (different number of moles of ethylene oxide added), and their Derivatives, 2,3-dihydroxypropyl methacrylate, 2-hydroxyethylacrylamide, and the like, and reactive emulsifiers having an ethylene oxide chain are preferred.
As the reactive emulsifier having an ethylene oxide chain, any emulsifier can be used as long as the chain number is 1 or more as long as the ethylene oxide chain is present. Among them, the chain number of the ethylene oxide chain is preferably 2 to 30. Hereinafter, emulsifiers of 3 to 15 are particularly preferable. As the nonionic emulsifier having an ethylene oxide chain, at least one selected from these groups can be used.

A commercially available product may be used as the nonionic emulsifier.
Examples of commercially available nonionic emulsifiers include the “Neugen” series, the “Aqualon” series (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), “Latemul PD-420”, “Latemul PD-430”, “Latemul PD”. -450 "," Emulgen "series (above, manufactured by Kao Corporation). Above all, reactions having ethylene oxide chains such as “AQUALON” series, “Latemul PD-420”, “Latemul PD-430”, “Latemul PD-450”, etc., and having a radical polymerizable double bond in the molecule The most effective emulsifier is used.
Moreover, although it is preferable that the coating composition of this indication does not use an ionic polymer particle as a polymer particle, it can also use an ionic polymer particle together. When mixing ionic polymer particles, the mixing amount is usually 30 parts by mass or less, preferably 10 parts by mass or less, and most preferably 3 parts by mass or less with respect to 100 parts by mass of the total amount of polymer particles. It is.

The number average primary particle size of the polymer particles is preferably 30 nm to 200 nm.
When the number average primary particle size of the polymer particles is 30 nm or more, a coating composition having excellent antireflection properties of the resulting film can be obtained.
In the film formation using the coating composition, the polymer particles are preferably removed from the coating film. However, by setting the number average primary particle size of the polymer particles to 30 nm or more, emptying due to the removal of the polymer particles is performed. A hole is obtained, and a film excellent in antireflection can be formed. This is because when pores resulting from the removal of polymer particles are formed by removing the polymer particles from the coating film by heat treatment, the film shrinks after cooling by removing the polymer particles by heat treatment. It is considered that the pores formed by removing the polymer particles are suppressed from being crushed as the membrane contracts, and the pores are sufficiently obtained in the membrane.
When the number average primary particle size of the polymer particles is 200 nm or less, a coating composition that is superior in antireflection properties, scratch resistance and antifouling properties of the resulting film can be obtained. This is because when the pores resulting from the removal of the polymer particles are formed by heat treatment, the number average primary particle size of the polymer particles is set to 200 nm or less so that fine holes on the film surface after the removal of the polymer particles are formed. It is considered that the formation can be effectively suppressed.
The number average primary particle size of the polymer particles is preferably 150 nm or less, and more preferably 120 nm or less, from the viewpoint of stable pore formation. The number average primary particle size of the polymer particles is preferably 40 nm or more, more preferably 60 nm or more, and still more preferably 80 nm or more, from the viewpoint of stable pore formation.

The number average primary particle diameter of the polymer particles is measured by a dynamic light scattering method. Specifically, the value obtained as a cumulative 50% value (d50) of the number-converted particle diameter was measured using Microtrac (Version 10.1.2-211BH) manufactured by Nikkiso Co., Ltd., and the number of polymer particles. The average primary particle size is used.

The ratio of the total mass of the polymer particles to the SiO ₂ equivalent mass of the hydrolyzable silane compound described below is preferably 0.1 or more and 1 or less, and 0.2 or more and 0, from the viewpoint of antireflection properties of the resulting film. Is more preferably 0.9 or less, and further preferably 0.3 or more and 0.6 or less.
The total weight ratio of polymer particles to SiO ₂ mass in terms of the hydrolyzable silane compound is a value obtained by (mass of polymer particles) / (SiO ₂ mass in terms of the hydrolyzable silane compound).
The SiO ₂ equivalent mass of the hydrolyzable silane compound can be calculated from the molecular weight of the hydrolyzable silane compound by analyzing the structure of the target hydrolyzable silane compound.

-Inorganic oxide precursors-
The coating composition of the present disclosure contains at least one inorganic oxide precursor. By containing the inorganic oxide precursor, when the film is formed by the coating composition, the hydrophobic portion of the inorganic oxide precursor is unevenly distributed on the film surface, and a flat film surface is obtained. Thereby, antifouling property becomes favorable and also the flaw resistance of a film | membrane improves.

Examples of the inorganic oxide precursor include an organometallic compound and a halogenated metal compound.
Examples of the organometallic compound include an aluminum chelate compound, a hydrolyzable silane compound, and a partially hydrolyzed condensate (eg, oligomer) of the hydrolyzable silane compound. As the partial hydrolysis-condensation product of the hydrolyzable silane compound, a siloxane oligomer having a weight average molecular weight of 600 to 6000 is preferable.
Examples of the aluminum chelate compound include aluminum ethyl acetoacetate diisopropylate, aluminum alkyl acetoacetate diisopropylate, aluminum monoacetylacetonate bis (ethylacetoacetate) and the like. As the aluminum chelate compound, a commercially available product may be used, and examples of the commercially available product include aluminum chelates (for example, aluminum chelate D and aluminum chelate M) manufactured by Kawaken Fine Chemical Co., Ltd.
Examples of the metal halide compound include silicon tetrachloride and aluminum chloride.
Among these, hydrolyzable silane compounds and partially hydrolyzed condensates of hydrolyzable silane compounds are preferred in that they have a low refractive index and high antireflection properties.

Among the hydrolyzable silane compounds, at least one compound selected from a hydrolyzable silane compound represented by the following formula (1) and a partial hydrolysis condensate of the hydrolyzable silane compound is preferable.
The coating composition of the present disclosure may contain water so that a part of the hydrolyzable silane compound may be hydrolyzed and condensed. Therefore, the coating composition of this indication contains the hydrolyzable silane compound represented by Formula (1), and the partial hydrolysis-condensation product of the hydrolyzable silane compound represented by Formula (1). Also good.

Formula (1): R ¹ —Si (OR ² ) ₃
In the formula (1), R ¹ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluorinated alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms, and R ² represents a hydrogen atom An atom or an alkyl group having 1 to 8 carbon atoms is represented.
When R ¹ and R ² represent an alkyl group having 1 to 8 carbon atoms, R ¹ and R ² may be the same or different.

The hydrolyzable silane compound represented by “R ¹ —Si (OR ² ) ₃ ” in the formula (1) is a trifunctional alkoxysilane or a tetrafunctional alkoxysilane.
Examples of the trifunctional alkoxysilane represented by “R ¹ —Si (OR ² ) ₃ ” include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and n-propyltrimethoxysilane. N-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-hexyltri Ethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltrieto Sisilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyl Triethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxy Silane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyana Topropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloyloxypropyltrin- And trialkoxysilanes such as propoxysilane, 3- (meth) acryloyloxypropyltriisopropoxysilane, 3-ureidopropyltrimethoxysilane, and 3-ureidopropyltriethoxysilane.

Examples of the tetrafunctional alkoxysilane represented by “R ¹ —Si (OR ² ) ₃ ” include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, and tetra-n-butoxysilane. And tetraalkoxysilane.
Among the hydrolyzable silane compounds represented by the formula (1), trifunctional alkoxysilanes are preferable from the viewpoint that the hydrolyzable silane compounds are likely to be unevenly distributed on the film surface and the antifouling property of the film is further improved.

Among the trifunctional alkoxysilanes represented by the formula (1), R ¹ and R ² are preferably compounds having 1 to 6 carbon atoms, and more preferably R ¹ and R ² have 1 to 6 carbon atoms. 3 is an alkyl group. Specifically, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, etc. Can be mentioned.

From the viewpoint that the hydrolyzable silane compound easily forms voids and the antireflection property when the antireflection film is formed is improved, partial hydrolysis condensation of the hydrolyzable silane compound represented by the above formula (1) Things are preferred.
Among these, a partial hydrolysis condensate of a hydrolyzable silane compound containing at least one unit (specific unit) selected from the following formula (2), formula (3) and formula (4) is more preferable. In this case, the effect of improving the scratch resistance of the film can also be expected.
Formula (2): R ¹ —Si (OR ² ) ₂ O _1/2 unit Formula (3): R ¹ —Si (OR ² ) O _2/2 unit Formula (4): R ¹ —Si—O _{3 / 2} units In the formulas (2), (3) and (4), each R ¹ independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluorinated alkyl group having 1 to 8 carbon atoms, or Represents an alkoxy group having 1 to 8 carbon atoms, and each R ² independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
Details of R ¹ and ^{R 2,} have the same meanings as ^{R 1} and ^{R 2} in Formula (1) also applies to the preferred embodiments.

Furthermore, the hydrolyzable silane compound tends to be unevenly distributed on the film surface, and is selected from the above formulas (2), (3) and (4) in that the antifouling property of the film is further improved. Among the units, R ¹ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a fluorinated alkyl group having 1 to 8 carbon atoms, and the total mass of the units is relative to the total mass of the hydrolyzable silane compound. It is preferable that it is 95 mass% or more. This is also suitable for improving the scratch resistance of the film.
As a hydrolysable silane compound in this indication, at least one sort of specific units chosen from the above-mentioned formula (2), formula (3), and formula (4) are 95 to the total mass of a hydrolyzable silane compound. It is preferable to contain at least mass% and have a weight average molecular weight of 600 to 6000. For example, a case where a tetrafunctional alkoxysilane and a trifunctional alkoxysilane capable of forming a specific unit are used in combination, and the total mass of the specific unit is 95% by mass or more based on the total mass of the hydrolyzable silane compound.

In the above formulas (2) to (4), R ¹ and R ² are more preferably within the following ranges. That is,
R ¹ each independently represents an alkyl group having 1 to 8 carbon atoms, and R ² each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
In the case where both the unit represented by the formula (2) and the unit represented by the formula (3) are included, the alkyl groups having 1 to 8 carbon atoms represented by R ¹ or R ² are the same. May be different.

The content of the specific unit in the hydrolyzable silane compound is preferably 98% by mass or more, more preferably 100% by mass from the viewpoint of further improving scratch resistance. In this case, antifouling properties can also be achieved.

The hydrolyzable silane compound is also preferably an oligomer having a weight average molecular weight of 600 to 6000. When the weight average molecular weight is in the above range, it is easy to achieve both scratch resistance and antifouling property of the film.
Specifically, when the hydrolyzable silane compound has a weight average molecular weight of 600 or more, the film obtained by the coating composition has excellent scratch resistance. This is presumably because the degree of condensation does not become too small when a film is formed from the coating composition. Further, when the weight average molecular weight of the hydrolyzable silane compound is 6000 or less, it becomes more excellent in scratch resistance and antifouling property. This is because it is easy to maintain the mobility of the hydrolyzable silane compound, and when the film is formed by the coating composition, the segregation amount of the hydrolyzable silane compound on the film surface is maintained, and a hardened surface layer is formed. it is conceivable that.

The weight average molecular weight of the hydrolyzable silane compound is preferably 1600 to 6000, more preferably 1600 to 3000 in terms of achieving both scratch resistance and antifouling properties and further improving it.

The weight average molecular weight refers to a value measured by gel permeation chromatography (GPC).
For measurement by GPC, HLC (registered trademark) -8020 GPC (Tosoh Corp.) is used as a measuring device, and TSKgel (Registered Trademark) Super Multipore HZ-H (4.6 mm ID × 15 cm, Tosoh Corp.) is used as a column. Are used, and dimethylformamide is used as an eluent. The measurement conditions are a sample concentration of 0.45 mass%, a flow rate of 0.35 mL / min, a sample injection amount of 10 μL, a measurement temperature of 40 ° C., and a differential refractive index (RI) detector. .
The calibration curve is “Standard sample TSK standard, polystyrene” of Tosoh Corporation: “F-40”, “F-20”, “F-4”, “F-1”, “A-5000”, “A -2500 "," A-1000 ", and" n-propylbenzene ".

The hydrolyzable silane compound is preferably a siloxane resin obtained using a trifunctional alkoxysilane capable of forming a specific unit. For example, at least one trifunctional alkoxysilane represented by the formula (1) is hydrolyzed. A siloxane resin obtained by condensation is also preferred.

In the hydrolyzable silane compound and the partial hydrolysis condensate thereof, the trifunctional alkoxysilane that can form the specific unit may contain one kind alone or two or more kinds.
The hydrolyzable silane compound, if necessary, a unit derived from a trifunctional alkoxysilane that can form a specific unit, a unit derived from another alkoxysilane other than the trifunctional alkoxysilane that can form a specific unit, and It may be a compound having In this case, the unit derived from the other alkoxysilane in the hydrolyzable silane compound is preferably less than 5% by mass of the total mass of the hydrolyzable silane compound.

Examples of the alkoxysilane that can be used in combination with the trifunctional alkoxysilane that can form the specific unit include trifunctional alkoxysilanes, tetrafunctional alkoxysilanes, and bifunctional alkoxysilanes other than the trifunctional alkoxysilane that can form the specific unit.
As the trifunctional alkoxysilane other than the trifunctional alkoxysilane capable of forming the specific unit, a trifunctional alkoxysilane other than the trifunctional alkoxysilane having a phenyl group is preferable. By using a trifunctional alkoxysilane other than the trifunctional alkoxysilane having a phenyl group, the mobility of the molecule can be maintained well. For this reason, in the film | membrane formed with the coating composition, the segregation to the film | membrane surface of a hydrolysable silane compound advances, and it is thought that it becomes easy to form the film | membrane which compatible favorable scratch resistance and antifouling property.

Examples of alkoxysilanes other than trifunctional alkoxysilanes include tetrafunctional alkoxysilanes and bifunctional alkoxysilanes.
Examples of the tetrafunctional alkoxysilane are as described above.
Examples of bifunctional alkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, diisopropyldimethoxysilane, diisopropyldi Ethoxysilane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-pentyldimethoxysilane, di-n-pentyldiethoxysilane, di-n-hexyldimethoxysilane, di-n-hexyl Examples include diethoxysilane, di-n-heptyldimethoxysilane, di-n-heptyldiethoxysilane, di-n-octyldimethoxysilane, and di-n-octyldiethoxysilane.
As the alkoxysilane other than the trifunctional alkoxysilane capable of forming the specific unit, only one kind may be used alone, or two or more kinds may be used.

The hydrolyzable silane compound in the present disclosure is an alkoxysilane (preferably a compound represented by the formula (1), the formula (2), the formula (3), and the formula (4) that forms at least one unit. 2), a trifunctional alkoxysilane forming at least one specific unit selected from the formulas (3) and (4) can be obtained by hydrolysis and condensation. For a specific synthesis method, for example, the description in JP-A No. 2000-159892 can be referred to.

As the hydrolyzable silane compound, a commercially available product may be used.
Examples of commercially available products include KC-89S (R ¹ : methyl group, R ² : methyl group, weight average molecular weight 770, manufactured by Shin-Etsu Chemical Co., Ltd.), KR-515 (R ¹ : methyl group, R ² : Methyl group, weight average molecular weight 1100, manufactured by Shin-Etsu Chemical Co., Ltd.), KR-500 (R ¹ : methyl group, R ² : methyl group, weight average molecular weight 1200, manufactured by Shin-Etsu Chemical Co., Ltd.), X-40 -9225 (R ¹ : methyl group, R ² : methyl group, weight average molecular weight 5200, manufactured by Shin-Etsu Chemical Co., Ltd.), X-40-9246 (R ¹ : methyl group, R ² : methyl group, weight average molecular weight) 3000, manufactured by Shin-Etsu Chemical Co., Ltd.), X-40-9250 (R ¹ : methyl group, R ² : methyl group, weight average molecular weight 6300, manufactured by Shin-Etsu Chemical Co., Ltd.).

The content of the hydrolyzable silane compound is preferably 1% by mass to 20% by mass, more preferably 1% by mass to 10% by mass, and more preferably 2% by mass to 8% by mass with respect to the total mass of the coating composition. Further preferred.

-Electrolytes-
The coating composition of the present disclosure contains at least one electrolyte selected from acids, bases and salts. By containing a specific electrolyte selected from an acid, a base, and a salt within a range that maintains the above pH, an antistatic effect required at the time of application can be obtained while suppressing an increase in pH. Thereby, the thickness unevenness of the coating film due to charging is suppressed, the occurrence of a bright spot failure is suppressed, and the corrosion resistance and the handling property are adapted.
The electrolyte refers to a compound that dissociates into a cation and an anion when dissolved in water as a solvent.
In the present disclosure, “acid” refers to a substance that provides H ⁺ , and “base” refers to a substance that receives H ⁺ . Of the acids, acids satisfying pKa <0 are strong acids.

As long as the acid can maintain the above-mentioned pH, either a weak acid or a strong acid may be used. Examples of the acid include weak acids such as acetic acid; strong acids such as nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid.
Examples of the base include sodium hydroxide, potassium hydroxide, ammonia and the like.
Examples of the salt include ammonium acetate, sodium acetate, potassium acetate, ammonium nitrate, sodium nitrate, potassium nitrate, ammonium sulfate, sodium sulfate, potassium sulfate, ammonium phosphate, sodium phosphate, potassium phosphate, ammonium chloride, sodium chloride and the like.

Moreover, it may replace with a salt and may add an acid and a base.
In the case of adding an acid and a base, it is preferable that the pKa of the acid is 5.5 or less and the pKa of the conjugate acid which is a base is 8.5 or more. When pKa is within the above range, ionization proceeds well and an improvement in conductivity can be expected.
Examples of adding an acid and a base include acetic acid (pKa: 4.8), hydrochloric acid (pKa: -8.0), sulfuric acid (pKa: -3.0), nitric acid (pKa: -1.4). ) And phosphoric acid (pKa: 2.1), sodium hydroxide (conjugated acid pKa: 15.7), potassium hydroxide (conjugated acid pKa: 15.7), ammonia (conjugated acid) PKa: 9.3) is added.

As the salt, an ammonium salt and a metal salt are preferable. Examples of the metal salt include a salt of an alkali metal (for example, sodium or potassium) and a salt of an alkaline earth metal (for example, magnesium or calcium). Among these, the metal salt remains in the film after the coating film is formed, and when the antireflection layer is formed as a functional layer, for example, the metal in the film affects the refractive index and has antireflection properties. An ammonium salt is preferable in that it may be lowered.
Therefore, as the salt, an ammonium salt of an acid selected from a weak acid and a strong acid is more preferable, and ammonium acetate, ammonium nitrate, ammonium sulfate, ammonium phosphate, ammonium chloride, and the like are more preferable.

The content of the electrolyte selected from acids, bases and salts is preferably 0.001 mol / L to 0.5 mol / L, and preferably 0.005 mol / L to 0.4 mol / L as the molar concentration in the coating composition. More preferred is 0.01 mol / L to 0.3 mol / L.
When the content of the electrolyte selected from an acid, a base, and a salt is 0.001 mol / L or more, conductivity for reducing bright spot failure can be obtained. Further, when the content of the electrolyte selected from an acid, a base, and a salt is 0.5 mol / L or less, there is no concern of reducing the antireflection property when the antireflection film is formed.

-water-
The coating composition of the present disclosure contains water. By containing water, the polymer particles are dispersed and the hydrolyzable silane compound is dissolved.
The water is preferably water that does not contain impurities or has a reduced content of impurities. For example, deionized water is preferred.

The content of water in the coating composition is preferably 0.5% by mass to 20% by mass and preferably 2% by mass with respect to the total mass of the coating composition from the viewpoint of further improving the scratch resistance of the resulting film. Is more preferably 15% by mass, and further preferably 4% by mass to 10% by mass.
It is thought that a silica matrix can be efficiently formed in the film | membrane obtained with a coating composition as content of water is in the said range. In the present disclosure, the silica matrix refers to a phase obtained by condensation of a hydrolyzable silane compound or the like.

The coating composition of the present disclosure may contain an organic solvent in addition to water.
The organic solvent is not limited as long as it is an organic solvent in which polymer particles are dispersed and a hydrolyzable silane compound is dissolved. Examples of the organic solvent include alcohol solvents, ester solvents, ketone solvents, ether solvents, amide solvents and the like.
In this case, the total content of water and the organic solvent with respect to the total mass of the coating composition is preferably 80% by mass to 99% by mass, more preferably 10% by mass to 98% by mass, and 92% by mass to 97% by mass. % Is more preferable.

Examples of alcohol solvents include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, 1-pentanol, and 2-pentanol. 1-hexanol, 2-hexanol, 3-hexanol, 3-methyl-3-pentanol, cyclopentanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-2-butanol, 2-methyl- 2-pentanol, 2-methyl-3-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, Alcohols such as cyclohexanol, 5-methyl-2-hexanol, 4-methyl-2-hexanol, etc. Glycols such as ethylene glycol, diethylene glycol, triethylene glycol; ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethyl butanol, ethylene glycol monoethyl ether, And glycol ether solvents containing a hydroxyl group such as ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and propylene glycol monoethyl ether.
Examples of the ester solvent include methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, propyl acetate, isopropyl acetate, amyl acetate (pentyl acetate), isoamyl acetate (isopentyl acetate, 3-methylbutyl acetate), acetic acid 2 -Methylbutyl, 1-methylbutyl acetate, hexyl acetate, isohexyl acetate, propylene glycol monomethyl ether acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, Examples include methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, and methyl propionate.
Examples of ketone solvents include acetone, 1-hexanone, 2-hexanone, diethyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, propylene carbonate, and γ-butyrolactone. Can be mentioned.
Examples of the ether solvent include, in addition to the above glycol ether solvent containing a hydroxyl group, a glycol ether solvent not containing a hydroxyl group such as propylene glycol dimethyl ether, an aromatic ether solvent such as anisole, dioxane, tetrahydrofuran, 1,4- Examples include dioxane and isopropyl ether.
As the amide solvent, for example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide and the like can be used.
Among these, from the viewpoint of dispersibility of the polymer particles, an alcohol solvent is preferable, monovalent alcohol is more preferable, ethanol or 2-propanol is more preferable, and 2-propanol is particularly preferable.

The coating composition of the present disclosure preferably contains both water and an organic solvent. As a suitable combination of water and an organic solvent, a mixed solvent of water and 2-propanol is preferable from the viewpoint of material solubility.

When both water and the organic solvent are contained, the content of the organic solvent relative to the total amount of water and the organic solvent is preferably 50% by mass or more, more preferably 65% by mass or more, and 80% by mass. It is still more preferable that it is above. The upper limit of the content of the organic solvent can be, for example, 98% by mass or less.
When both the water and the organic solvent are contained, the antireflection property of the film obtained from the coating composition is more excellent by containing 50% by mass or more of the organic solvent. This is considered to be because a coating film having an excellent surface shape is easily obtained.

-Other ingredients-
The coating composition of the present disclosure may contain components other than the above components as long as the effects of the coating composition of the present disclosure are not significantly impaired.
Examples of other components include inorganic particles having a number average primary particle size of 3 nm to 100 nm, alkali metal silicates, surfactants, thickeners, and the like.

(Inorganic particles with a number average primary particle size of 3 nm to 100 nm)
The coating composition may contain inorganic particles having a number average primary particle size of 3 nm to 100 nm (hereinafter also referred to as “specific inorganic particles”). By containing inorganic particles having a number average primary particle size of 3 nm to 100 nm in the coating composition, the scratch resistance and antifouling property of the resulting film can be improved while maintaining suitable antireflection properties.

The specific inorganic particles are particles containing at least one of boron, phosphorus, silicon, aluminum, titanium, zirconium, zinc, tin, indium, gallium, germanium, antimony, molybdenum, cerium and the like, preferably at least of the above elements It is an oxide particle containing one element. Examples of such oxide particles include particles of silicon oxide (silica), titanium oxide, aluminum oxide (alumina), zinc oxide, germanium oxide, indium oxide, tin oxide, antimony oxide, cerium oxide, zirconium oxide, and the like. . The specific inorganic particles may contain other metal oxides other than those listed here.
From the viewpoint of further improving the antireflection property and scratch resistance of the film, silica or alumina particles are preferably used as the specific inorganic particles, and silica particles are more preferably used. Examples of the silica particles include hollow silica particles, porous silica particles, and nonporous silica particles. The shape of the silica particles is not particularly limited, and may be any shape such as a spherical shape, an elliptical shape, or a chain shape.
The silica particles may be silica particles whose surfaces are treated with an aluminum compound or the like.

The coating composition may contain two or more kinds of specific inorganic particles. When two or more types of specific inorganic particles are included, two or more types of specific inorganic particles having different shapes, particle sizes, and elemental compositions can be included.
The number average primary particle size of the specific inorganic particles is 3 nm to 100 nm. By setting the particle size to 3 nm or more, a sufficient scratch resistance improvement effect by adding the specific inorganic particles can be obtained. Moreover, by setting the particle size to 100 nm or less, the porosity of the film can be maintained at an appropriate value even when specific inorganic particles are added, and excellent antireflection performance can be obtained.
The number average primary particle size of the specific inorganic particles is preferably 80 nm or less, more preferably 30 nm or less, and particularly preferably 15 nm or less.

The number-average primary particle size of the specific inorganic particles can be obtained from an image of a photograph taken by observing the dispersed silica specific inorganic particles with a transmission electron microscope. Specifically, for 200 particles randomly extracted from the image of the photograph, the projected area of the specific inorganic particles is measured, the equivalent circle diameter is obtained from the measured projected area, and the obtained equivalent circle diameter value is obtained. The value obtained by arithmetic averaging is taken as the number average primary particle size of the specific inorganic particles.

As the silica particles suitably contained in the coating composition, nonporous silica particles are preferable.
“Nonporous silica particles” mean silica particles having no voids inside the particles, and are distinguished from silica particles having voids inside the particles such as hollow silica particles and porous silica particles. The “non-porous silica particles” have a core such as a polymer inside the particles, and the outer shell (shell) of the core is silica or a precursor of silica (for example, a material that changes to silica by firing).
The core-shell structured silica particles are not included.

When the non-porous silica particles are baked, it is considered that the state of the particles present in the coating film changes before and after baking. Specifically, in the coating film before firing, a state in which the respective nonporous silica particles are aggregated into a single particle (a state in which the particles are aggregated by van der Waals force or the like) is defined as a single particle. In the coating film after firing, it is considered that at least a part of the plurality of nonporous silica particles is present as a linked particle body connected to each other.
When the silica particles contained in the coating composition are nonporous silica particles, the scratch resistance is further improved. This is considered to be because the hardness of the film is increased because a plurality of nonporous silica particles are connected to form a particle connected body by baking the coating film.

Commercially available products may be used as the silica particles. Examples of commercially available products include NALCO (registered trademark) 8699 (aqueous dispersion of nonporous silica particles, number average primary particle size: 3 nm, solid content: 15% by mass, manufactured by NALCO), NALCO (registered trademark) 1130. (Aqueous dispersion of nonporous silica particles, number average primary particle size: 8 nm, solid content: 30% by mass, manufactured by NALCO), NALCO (registered trademark) 1030 (aqueous dispersion of nonporous silica particles, number average) Primary particle size: 13 nm, solid content: 30% by mass, manufactured by NALCO, NALCO (registered trademark) 1050 (aqueous dispersion of non-porous silica particles, number average primary particle size: 20 nm, solid content: 50% by mass, NALCO (trade name), NALCO (registered trademark) 1060 (aqueous dispersion of nonporous silica particles, number average primary particle size: 60 nm, solid content: 50% by mass, produced by NALCO), Snowtex (registered trade name) ST OXS (aqueous dispersion of nonporous silica particles, number average primary particle size: 4 nm to 6 nm, solid content: 10% by mass, manufactured by Nissan Chemical Industries), Snowtex (registered trademark) ST-O (nonporous silica) Water dispersion of particles, number average primary particle size: 10 nm to 15 nm, solid content: 20% by mass, manufactured by Nissan Chemical Industries, Ltd., Snowtex (registered trademark) ST-O-40 (water dispersion of nonporous silica particles) Product, number average primary particle size: 20 nm to 25 nm, solid content: 40% by mass, manufactured by Nissan Chemical Industries, Ltd., Snowtex (registered trademark) ST-OYL (aqueous dispersion of nonporous silica particles, number average primary particle) Diameter: 50 to 80 nm, solid content: 20% by mass, manufactured by Nissan Chemical Industries, Ltd., Snowtex (registered trademark) ST-OUP (aqueous dispersion of non-porous silica particles, number average primary particle size: 40 nm to 100 nm, Solid content: 15% by mass, Made production Chemical Industry Co., Ltd.), and the like.

The specific inorganic particles can be contained to such an extent that the effects according to the embodiment of the present invention are not impaired, and the content thereof is 0.03 to 1.0 in terms of mass ratio with respect to the hydrolyzable silane compound. Preferably, 0.03 to 0.5 is more preferable, and 0.03 to 0.1 is most preferable. When the content ratio of the inorganic particles to the hydrolyzable silane compound is 0.03 or more, a film quality excellent in scratch resistance is easily obtained. When the content ratio of the inorganic particles to the hydrolyzable silane compound is 1.0 or less, it is advantageous for forming a film having a small surface unevenness and a good surface condition, and excellent antifouling properties are easily obtained.

(Alkali metal silicate)
The coating composition may contain an alkali metal silicate.
By containing an alkali metal silicate, both antireflection properties and scratch resistance can be improved. The alkali metal silicate refers to an alkali metal salt of silicic acid, and an alkali metal silicate represented by the following formula A is preferable.
M ₂ O · nSiO ₂ Formula A

In the formula A, M represents an alkali metal.
Examples of the alkali metal include lithium (Li), sodium (Na), potassium (K), cesium (Cs), and the like.
As the alkali metal represented by M, Li or K is preferable.
By selecting Li or K as the alkali metal, the scratch resistance is further improved as compared with Na.
In formula A, n represents the molar ratio of alkali metal silicate. n is preferably a compound of 5.0 or less from the viewpoint of crosslinkability.
When the molar ratio n of the alkali metal silicate is an appropriate value, it is considered that crosslinking becomes easy. Therefore, when M is Li, it is considered that by selecting a compound satisfying n ≦ 5.0, the alkali metal silicate is easily crosslinked with the silica particles, and the scratch resistance is further improved. When the alkali metal represented by M is Li, n is more preferably 3.0 or more.

(Surfactant)
The coating composition can contain a surfactant. By containing the surfactant, it is effective in improving the wettability of the coating composition to the substrate.
Examples of the surfactant include acetylene-based nonionic surfactants and polyol-based nonionic surfactants. As the surfactant, commercially available products may be used. For example, Olfin series (for example, Olphine EXP.4200, Olphine EXP.4123, etc.) manufactured by Nissin Chemical Industry Co., Ltd., Dow Chemical Co., Ltd. TRITON BG-10 manufactured by Kao Corporation or Mydoll series manufactured by Kao Corporation (for example, Mydoll 10, Mydoll 12, etc.) can be used.

(Thickener)
The coating composition can contain a thickener. By including the thickener, the viscosity of the coating composition can be adjusted.
Examples of the thickener include polyether, urethane-modified polyether, polyacrylic acid, polyacryl sulfonate, polyvinyl alcohol, and polysaccharides. Among these, polyether, modified polyacrylic sulfonate, and polyvinyl alcohol are preferable. Commercially available products that are marketed as thickeners may be used. Examples of commercially available products include SN thickener 601 (polyether), SN thickener 615 (modified polyacrylic sulfonate), and Fuji Film manufactured by San Nopco. Examples include polyvinyl alcohol (degree of polymerization: about 1,000 to 2,000) manufactured by Wako Pure Chemical Industries.
The content of the thickener is preferably about 0.01% by mass to 5.0% by mass with respect to the total mass of the coating composition.

~ Solid content ~
The solid content of the coating composition is preferably 1% by mass to 20% by mass, more preferably 1% by mass to 10% by mass, and still more preferably 2% by mass to 8% by mass with respect to the total mass of the coating composition.
When the solid content of the coating composition is within the above range, the film obtained from the coating composition can be a film that can provide better antireflection properties. This is because when the solid content is in the above range, the coating film of the coating composition can follow the coating surface of the substrate with a uniform film thickness, and a film with a uniform thickness without film thickness unevenness can be obtained. This is probably because of this.
The solid content in the coating composition can be adjusted by the content of water or water and an organic solvent.
In addition, solid content amount in this indication means the ratio of the mass remove | excluding water and the organic solvent from the coating composition with respect to the total mass of a coating composition.

The coating composition of the present disclosure has the effect of suppressing unevenness in the thickness of the coating film due to charging during coating, and consequently suppressing the occurrence of bright spot failures.
From this viewpoint, the coating composition of the present disclosure can be suitably used for forming an antireflection film that is a cured product of the coating composition, for example. The antireflection film using the coating composition of the present disclosure is excellent in antireflection properties because a film having an appropriate refractive index is formed with a highly uniform thickness in which occurrence of uneven thickness is suppressed. . Further, as described above, it can be excellent in scratch resistance and antifouling property.

An antireflection film will be described as an example as a cured product of the coating composition of the present disclosure.
The coating composition of the present disclosure can be suitably used for coating formation of a cured film of a laminate having a substrate having a concavo-convex structure on the surface and a cured film. For example, a windshield mounted on a solar cell module has an antireflection film for reducing the reflection of sunlight on a glass substrate, and provides an antiglare property to the surface of the glass substrate. An uneven shape is provided for the purpose.

The antireflection property of the antireflection film is indicated by the following change in average reflectance (ΔR).
In the antireflection film according to the present disclosure, the numerical value of ΔR is a positive value.
Specifically, the reflectivity of a laminate in which an antireflection film is formed on a base material using a UV-visible-infrared spectrophotometer (model number: UV3100PC, manufactured by Shimadzu Corporation) in light having a wavelength of 400 nm to 1,100 nm. (%) Is measured using an integrating sphere. When measuring the reflectance, a black tape (model number: SPV-202) is applied to the surface of the base material that is the back surface in order to suppress reflection of the back surface of the laminate (the surface on the side where the antireflection film of the base material is not formed). , Made by Nitto Denko). Then, the average reflectance (R ^AV ; unit%) of the laminate is calculated from the measured reflectance at each wavelength in the wavelength range of 400 nm to 1,100 nm. Similarly, the reflectance (%) of light having a wavelength of 400 nm to 1,100 nm of a base material on which no antireflection film is formed is measured. Then, the average reflectance (R ^0AV ; unit%) of the substrate is calculated from the measured reflectance at each wavelength in the wavelength range of 400 nm to 1,100 nm.
Next, a change (ΔR; unit:%) of the average reflectance with respect to the base material on which the antireflection film is formed is ^calculated from the average reflectances R ^AV and R ^0AV according to the following formula (a).
ΔR = R ^0AV −R ^AV formula (a)
ΔR indicates that the greater the value is and the greater the value, the better the antireflection (AR) property.

The reflectance can be measured by using a spectrophotometer with an integrating sphere. In the present disclosure, an ultraviolet-visible-infrared spectrophotometer (model number: UV3100PC, manufactured by Shimadzu Corporation) is used as a measuring apparatus, and the reflectance in light having a wavelength of 400 nm to 1,100 nm is measured using an integrating sphere, A value obtained by arithmetically averaging the reflectance values at the wavelengths of is used as the average reflectance.

ΔR of the antireflection film is preferably 2.3% or more, more preferably 2.6% or more from the viewpoint of antireflection properties.

The average film thickness of the antireflection film can be in the range of 50 nm to 250 nm from the viewpoint of antireflection properties. Among these, 80 nm to 200 nm is preferable from the viewpoint of antireflection properties.
For the average film thickness, the antireflection film was cut in parallel to the direction perpendicular to the film surface, and the cut surface was observed at 10 points with a scanning electron microscope (SEM). It is obtained by measuring the thickness and averaging the ten measured values (film thickness) obtained. When the antireflection film is formed on the base material, the antireflection film is cut together with the base material in a direction perpendicular to the substrate surface of the base material, and the above observation is performed. As a base material, the base material used for manufacture of the laminated body mentioned later can be used.

<Method for producing laminate>
The method for producing a laminate of the present disclosure includes a step of applying the above-described coating composition of the present disclosure on a substrate with a roll coater to form a coating film (hereinafter also referred to as “coating film forming step”). And a step of drying the coating film (hereinafter also referred to as “drying step”) and a step of baking the coating film that has undergone the drying step to obtain a cured film (hereinafter also referred to as “baking step”). . Moreover, the manufacturing method of the laminated body of this indication may have other processes, such as a washing process, a surface treatment process, and a cooling process, as needed.

In the method for producing a laminate according to the present disclosure, since the coating composition described above is used, the laminate has excellent antireflection properties and the occurrence of bright spot failures regardless of the surface state of the substrate. The body is manufactured and has excellent scratch resistance and antifouling properties.

-Coating film formation process-
In the coating film forming step, the above-described coating composition of the present disclosure is coated on a substrate with a roll coater to form a coating film.

In the coating film forming step, as described above, the present disclosure includes a specific electrolyte, polymer particles, and a hydrolyzable silane compound so as to suppress charging during coating and suppress the occurrence of coating thickness unevenness. Since the coating composition is used, the film formed through at least the drying process and the baking process described later can suppress the occurrence of bright spot-like failure, and has excellent antireflection properties when it is an antireflection film. It becomes. In addition, the film has excellent scratch resistance and antifouling properties.

The coating amount of the coating composition is not particularly limited, and can be appropriately set in consideration of operability and the like according to the solid content concentration in the coating composition, the desired film thickness, and the like. The coating amount of the coating composition is preferably 0.01 mL / m ² to 30 mL / m ² , more preferably 0.1 mL / m ² to 20 mL / m ² , and 1 mL / m ² to 15 mL / m ^2. it is more preferably m ^2. When the coating amount of the coating composition is within the above range, the coating accuracy is improved, and a film having better antireflection properties can be formed.

In the method for manufacturing a laminate of the present disclosure, a roll coater is used for coating in the coating film forming step. When a film is formed using a roll coater, the surface of the substrate is charged and the coating film is likely to have uneven thickness. The uneven thickness of the coating film due to charging causes a bright spot-like failure.
The occurrence of bright spot failure is particularly likely to occur when the surface material of the roll (that is, the coating roll) that applies the coating composition to the surface of the substrate is rubber. Therefore, when the coating roll containing rubber is applied to at least a part of the surface, the effect of the manufacturing method of the laminate of the present disclosure is further enhanced.
An example of the rubber is ethylene propylene diene rubber (EPDM).

As the base material, any base material such as glass, resin, metal, ceramic, or a composite material in which at least one selected from glass, resin, metal, and ceramic is combined can be selected.
Even when any substrate is used, the effect of the method for producing a laminate of the present disclosure is expected, but the coating roll on which the coating composition is applied is most likely to interact with the substrate. A glass substrate is preferable in that the effect is further enhanced.

When a glass substrate is used, the condensation of hydroxy groups occurs not only between the hydroxyl groups of the hydrolyzable silane compound but also between the hydroxyl group of the hydrolyzable silane compound and the hydroxyl group of the glass surface, A coating film having excellent adhesion to the substrate can be formed.

Among the base materials, when a base material having a concavo-convex structure on the surface is used, the effect of the method for manufacturing a laminate of the present disclosure is further enhanced.
The base material having a concavo-convex structure refers to a base material having a surface arithmetic average roughness Ra of 0.1 μm to 1.0 μm. By laminating a coating film on a substrate having Ra in this range, a laminate having antiglare properties and functions such as antireflection is formed. Ra is more preferably 0.2 μm to 0.7 μm from the viewpoint of imparting functions such as antiglare property and antireflection.
The arithmetic average roughness Ra is a value measured according to JIS-B0601 using a surface roughness meter (model number: Handy Surf E-35B, manufactured by Tokyo Seimitsu Co., Ltd.).

-Drying process-
In the drying process, the coating film formed in the coating film forming process is dried.
In the drying step, the coating film is preferably fixed on the substrate by removing the solvent in the coating composition.
A dense film is formed by removing the solvent in the coating composition. If the coating composition contains inorganic particles such as silica particles, the inorganic particles are densely arranged in the film, and a denser film is formed. It is considered that excellent scratch resistance can be obtained when the film becomes dense and the hardness increases. Moreover, since the film becomes dense and the film surface becomes smooth, it is considered that dirt is difficult to adhere and the antifouling property is excellent.

The coating film may be dried at room temperature (25 ° C.) or using a heating device.
The heating device is not particularly limited as long as it can be heated to a target temperature, and any known heating device can be used. As the heating device, an oven, an electric furnace, or the like, or a heating device uniquely manufactured according to the production line can be used.

The coating film may be dried by, for example, heating the coating film at an ambient temperature of 40 ° C. to 200 ° C. using the above heating device. When the coating film is dried by heating, for example, the heating time can be about 1 to 30 minutes.
The drying conditions for the coating film are preferably drying conditions in which the coating film is heated at an atmospheric temperature of 40 ° C. to 200 ° C. for 1 minute to 10 minutes, and drying is performed at an atmospheric temperature of 100 ° C. to 180 ° C. for 1 minute to 5 minutes. Conditions are more preferred.

The average film thickness of the coating film after drying can be in the range of 50 nm or more, and preferably in the range of 80 nm to 200 nm. When the average film thickness is 50 nm or more, the film has excellent antireflection properties, and when it is 80 to 200 nm, the antireflection properties are excellent. The method for measuring the average film thickness is as described above.

-Baking process-
In the firing step, the coating film that has undergone the drying step is fired to obtain a cured film.
In the firing step, firing is preferably performed at an ambient temperature of 400 ° C. to 800 ° C. By baking the dried coating film at an ambient temperature of 400 ° C. to 800 ° C., the hardness of the dense film formed in the drying process is further increased, and the scratch resistance is further improved. Furthermore, since organic components in the coating film, especially at least part of the polymer particles, are thermally decomposed and disappeared by baking, voids of any size are partially formed in the coating film after baking, and antireflection properties Can be improved effectively.

The coating film can be baked using a heating device. The heating device is not particularly limited as long as it can be heated to a target temperature, and any known heating device can be used. As the heating device, in addition to an electric furnace or the like, it is possible to use a firing device uniquely produced in accordance with a production line.
The firing temperature (atmosphere temperature) of the coating film is more preferably 450 ° C. or higher and 800 ° C. or lower, further preferably 500 ° C. or higher and 800 ° C. or lower, and particularly preferably 600 ° C. or higher and 800 ° C. or lower. The firing time is preferably from 1 minute to 10 minutes, and more preferably from 1 minute to 5 minutes.

The average film thickness of the cured film is preferably 80 nm to 200 nm.
When the average film thickness of the cured film after firing is within the above range, the antireflection property of the film is excellent when the laminate has an antireflection film.
The average film thickness is obtained by cutting a laminate having a fired film sample (for example, an antireflection film) on a glass substrate in parallel to a direction perpendicular to the substrate surface of the substrate, and then using the scanning electron microscope ( It is obtained by observing 10 spots with SEM, measuring the film thickness of each observed spot from 10 SEM images, and averaging the 10 measured values (film thickness) obtained.

-Other processes-
The manufacturing method of the laminated body of this indication may include other processes other than said process as needed. Examples of other processes include a cleaning process, a surface treatment process, and a cooling process.

The laminated body in the present disclosure may be a windshield mounted on a solar cell module. In this case, the solar cell module includes a laminate in the present disclosure, that is, a laminate having the base material and the antireflection film in the present disclosure.
The solar cell module includes a solar cell element that converts light energy of sunlight into electric energy, a laminate according to the present disclosure that is disposed on a side where sunlight enters, and a solar cell backsheet represented by a polyester film. It may be arranged between and. The laminate according to the present disclosure and a back sheet for solar cells such as a polyester film are sealed with a sealing material typified by a resin such as an ethylene-vinyl acetate copolymer.

Since the solar cell module includes the laminate having the above-described antireflection film, the solar cell module has excellent antireflection properties and excellent scratch resistance. Therefore, light caused by scratches on the film surface when used for a long period of time. It is considered that the decrease in permeability is suppressed and the power generation efficiency is excellent.
The solar cell module according to the present disclosure preferably includes the laminate according to the present disclosure in the outermost layer of the solar cell module. That is, the outermost layer of the solar cell module according to the present disclosure is preferably an antireflection film. In the solar cell module of the present disclosure, even if the outermost layer is an antireflection film, the antireflection film according to the present disclosure has an antifouling property that can easily remove a resin such as a sealing material. Excellent production efficiency can be obtained.

The members other than the laminate and the back sheet in the solar cell module are described in detail in, for example, “Solar power generation system constituent material” (supervised by Eiichi Sugimoto, Kogyo Kenkyukai, 2008). As for a solar cell module, the form provided with the layered product concerning this indication on the side which sunlight enters is preferred, and there is no restriction in composition other than the layered product concerning this indication.

The base material disposed on the solar light incident side of the solar cell module is preferably in the form of a base material of the laminate according to the present disclosure. Examples of the base material include glass, resin, metal, ceramic, or And a base material such as a composite material obtained by combining at least one selected from glass, resin, metal and ceramic. A preferred substrate is a glass substrate.

There is no restriction | limiting in particular as a solar cell element used for a solar cell module. Solar cell modules include silicon-based solar cell elements such as single crystal silicon, polycrystalline silicon, and amorphous silicon, copper-indium-gallium-selenium, copper-indium-selenium, cadmium-tellurium, gallium-arsenic III-V Any of various known solar cell elements such as Group II or Group II-VI compound semiconductor solar cell elements can be applied.

Hereinafter, embodiments of the method for producing a coating composition and a laminate according to the present disclosure will be described more specifically by way of examples. However, the embodiments in the present disclosure are not limited to the following examples as long as they do not exceed the gist thereof.

Example 1
-Synthesis of polymer particles 1-
A mixed solution having the following composition was stirred and emulsified with a homogenizer at 10,000 rpm (round per minute) for 5 minutes while cooling to obtain 64.8 parts by mass of an emulsion.
<Composition of mixture>
Ion exchange water: 35 parts by mass Methyl methacrylate: 13.8 parts by mass,
n-butyl acrylate: 13.8 parts by mass,
Methoxypolyethyleneglycol methacrylate (n = 9): 0.6 parts by mass Diethylene glycol dimethacrylate: 0.6 parts by mass Nonionic reactive emulsifier having an ethylene oxide chain (trade name: Latemul PD-450 (main component: polyoxyalkylene alkenyl ether) , Manufactured by Kao Corporation): 0.4 parts by mass Polymerization initiator (trade name V-65, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.): 0.6 parts by mass

On the other hand, in a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen gas blowing tube, ion-exchanged water: 35 parts by mass, a nonionic reactive emulsifier having an ethylene oxide chain (trade name LATEMUL PD-450 (main component : Polyoxyalkylene alkenyl ether), manufactured by Kao Corporation): 0.2 part by mass was added, the temperature was raised to 65 ° C., and then the atmosphere was replaced with nitrogen.
The emulsion was uniformly dropped over 3 hours while maintaining 65 ° C under a nitrogen atmosphere, and further reacted at 65 ° C for 2 hours.
After completion of the reaction, the reaction mixture was cooled to obtain an aqueous emulsion (polymer particle 1) having a solid content concentration of 30% by mass and an average primary particle size of 100 nm.

Polymer particles 1 (active ingredient concentration 30% by mass) 2.5 parts by mass and KR-500 (inorganic oxide precursor (methyltrimethoxysilane oligomer), manufactured by Shin-Etsu Chemical Co., Ltd., active ingredient concentration 100% by mass) 3 0.1 part by mass, 0.5 parts by mass of an acetic acid aqueous solution (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., diluted with water to an active ingredient concentration of 10% by mass) and an aqueous ammonium acetate solution (Fuji Film Wako Pure Chemical Industries, Ltd.) 0.05 parts by weight, 4.7 parts by weight of water, 89.1 parts by weight of Toxo IPA (2-propanol, manufactured by Tokuyama Corporation), Were mixed and stirred to prepare a coating solution (coating composition).
It was pH = 7.3 when pH (25 degreeC) of the coating liquid was measured by the method shown below.
Moreover, when the electrical conductivity (25 degreeC) of the coating liquid was measured by the method shown below, it was electrical conductivity = 1.0 mS / m.

-Production of membrane samples and laminates-
The prepared coating solution was coated on a 3 mm thick template glass substrate (arithmetic mean roughness Ra of coated surface Ra = 0.4 μm) using a roll coater (material: EPDM (ethylene propylene diene rubber)) (coating amount: 0.2 mL / m ² to 3 mL / m ² ) to form a coating film, which was then dried using an oven at an ambient temperature of 100 ° C. for 1 minute.
Next, the dried coating film was baked at an atmospheric temperature of 700 ° C. for 3 minutes using an electric furnace to prepare a film sample (antireflection film).
As described above, a laminate having a film sample as an antireflection film on a glass substrate was obtained. The film sample was formed so that the final average film thickness of the film sample formed on the glass substrate was 130 nm.
Ra was measured according to JIS-B0601 using a surface roughness meter (model number: Handy Surf E-35B, manufactured by Tokyo Seimitsu Co., Ltd.).

The average film thickness is obtained by cutting a laminate having a fired film sample (antireflection film) on a glass substrate in parallel to a direction orthogonal to the substrate surface of the substrate, and then cutting the cut surface with a scanning electron microscope (SEM). 10), the film thickness of each observation part was measured from 10 SEM images, and the obtained 10 measured values (film thickness) were averaged.

-Evaluation-
The following evaluation was performed using the coating solution, film sample or laminate obtained above. The evaluation results are shown in Table 1.
In Tables 1 to 6, “-” in the added amount of each component indicates that the corresponding component is not contained.

(1) Bright spot-like failure The surface of the laminate having the fired film sample (antireflection film) on the template glass substrate is viewed with a laser microscope (model number: VK-9710, manufactured by KEYENCE) with a field of view of 10 cm. It was observed by ² to calculate the number per unit area by counting the number of bright pixel indicated by the arrow in FIG.
It is evaluated that the bright spot-like failure is suppressed as the number is smaller.

(2) pH
The coating solution was measured at 25 ° C. using a pH meter (model number: HM-31, manufactured by Toa DKK).

(3) Conductivity The coating solution was measured at 25 ° C. using a conductivity meter (model number: CM-30R, cell: CT-57101B, Toa DKK).

(4) Antireflection (AR) property A wavelength of 380 nm of a laminate in which a film sample (antireflection film) is formed on a glass substrate by an ultraviolet visible infrared spectrophotometer (model number: UV3100PC, manufactured by Shimadzu Corporation). The reflectance (%) in light of ˜1,100 nm was measured using an integrating sphere. The reflectance was measured by attaching a black tape to the surface of the glass substrate serving as the back surface in order to suppress reflection of the back surface of the laminate (the surface on which the film sample of the glass substrate was not formed). . Then, the average reflectance (R ^AV ; unit%) of the laminate was calculated from the measured reflectance of each wavelength at wavelengths of 380 nm to 1,100 nm.
In the same manner as described above, the reflectance (%) of light with a wavelength of 380 nm to 1,100 nm was measured for a glass substrate on which no film sample was formed. Then, the average reflectance (R ^0AV ; unit%) of the glass substrate was calculated from the measured reflectance of each wavelength at wavelengths of 380 nm to 1,100 nm.
From the above average reflectances R ^AV and R ^0AV , the average reflectance change (ΔR; unit:%) relative to the glass substrate on which no film sample was formed was calculated according to the following formula (a).
ΔR indicates that the larger the value, the better the antireflection (AR) property.
ΔR = R ^0AV −R ^AV formula (a)
The allowable range of antireflection properties is 2.3% or more, and preferably 2.6% or more.
The calculated antireflection performance (ΔR) was ranked according to the evaluation criteria shown below. Ranks A to C are allowable ranges for antireflection.
<Evaluation criteria>
A: ΔR ≧ 2.9
B: 2.6 ≦ ΔR <2.9
C: 2.3 ≦ ΔR <2.6
D: 2.0 ≦ ΔR <2.3
E: ΔR <2.0

(5) Antifouling property (tape adhesive residue)
Cellotape (registered trademark) (manufactured by Nichiban Co., Ltd., width 18 mm, length 56 mm) was attached to the membrane surface of the membrane sample and rubbed with an eraser to attach the tape to the sample membrane. One minute after the tape was attached, the end of the tape was held and held at a right angle to the sample film surface, and peeled off instantaneously.
After that, the area where the tape of the sample film was adhered was divided into 100 rows of 10 rows × 10 columns = 100 continuous lattices, and the lattice in which the adhesive of the tape remained without being peeled out of the 100 lattices. The number (x) of was measured. The smaller the value of x, the better the antifouling property (tape adhesive residue).
The allowable range of the tape adhesive remaining property is that the number of grids (x) is 9 or less. The number (x) of the measured grids was ranked according to the evaluation criteria shown below.
<Evaluation criteria>
A: x ≦ 3 B: 4 ≦ x ≦ 9 C: x ≧ 10

(Examples 2 to 20, Comparative Examples 1 to 4)
In Example 1, a coating solution was prepared in the same manner as in Example 1 except that the types and amounts of the compounds in the coating composition were changed as shown in Tables 1 to 6 below. A laminate was prepared and further measured and evaluated. The results of measurement and evaluation are shown in Tables 1 to 6 below.
The average film thicknesses of the film samples (antireflection films) in Examples 2 to 20 and Comparative Examples 1 to 4 are both 130 nm as in Example 1.
In Tables 1 to 6, “-” in the added amount of each component indicates that the corresponding component is not contained.

Details of the components in Tables 1 to 6 are as follows.
KR-500: methyltrimethoxysilane oligomer (inorganic oxide precursor (unit 20% to 30% by mass represented by the above formula (2) and unit 70% to 80% represented by the above formula (3) Hydrolyzable silane compound containing mass%); SiO ₂ : 63 mass%, Shin-Etsu Chemical Co., Ltd.)
KBM-13: Methyltrimethoxysilane (inorganic oxide precursor (unit: 100% by mass represented by the above formula (1)); SiO ₂ : 44% by mass, Shin-Etsu Chemical Co., Ltd.)
MS-51: tetramethoxysilane oligomer (inorganic oxide precursor (units represented by the above formula (2) 45 mass% to 55 mass% and units represented by the above formula (3) 45 mass% to 55 mass%) % Hydrolyzable silane compound); SiO ₂ : 52% by mass, Shin-Etsu Chemical Co., Ltd.)
KBE-04: tetraethoxysilane (inorganic oxide precursor (unit: 100% by mass represented by the above formula (1)); SiO ₂ : 29% by mass, Shin-Etsu Chemical Co., Ltd.)
Aluminum chelate D: Aluminum monoacetylacetonate bis (ethylacetoacetate) (Kawaken Fine Chemical Co., Ltd.)
Acetic acid: FUJIFILM Wako Pure Chemicals, pKa: 4.8
・ Nitric acid: FUJIFILM Wako Pure Chemicals, pKa: -1.4
・ Phosphoric acid: FUJIFILM Wako Pure Chemicals, pKa: 2.1
・ Ammonia: FUJIFILM Wako Pure Chemicals, pKa: 9.3 (conjugated acid)
・ Ammonium acetate: FUJIFILM Wako Pure Chemical Co., Ltd. ・ Ammonium nitrate: FUJIFILM Wako Pure Chemical Co., Ltd. ・ Ammonium sulfate: FUJIFILM Wako Pure Chemical Co., Ltd. Yakuhin Co., Ltd. Sodium nitrate: FUJIFILM Wako Pure Chemicals Co., Ltd. Sodium chloride: FUJIFILM Wako Pure Chemicals Co., Ltd. Water: Deionized water IPA: Toxo IPA (2-propanol; manufactured by Tokuyama Co., Ltd.)

As shown in Tables 1 to 6, in the coating compositions of Examples containing an electrolyte selected from acids, bases and salts in a predetermined pH range, the occurrence of bright spot failure is effectively suppressed. In addition, the electrical conductivity was ensured, and the decrease in the antireflection property due to the withstand voltage was also suppressed.
When an ammonium salt was used as the electrolyte, as shown in Examples 9 to 16, the antireflection property was superior to the case where an alkali metal salt was used. This is presumably because the alkali metal remained in the film changed the refractive index and adversely affected the antireflection performance. Therefore, it is considered that an ammonium salt is more preferable as the electrolyte than a metal salt.
In addition, as shown in Examples 17 to 20, the inorganic oxide precursor is superior in antireflection and antifouling properties when a hydrolyzable silane compound is used as compared with Example 20 using aluminum chelate. It was.
On the other hand, in Comparative Examples 1 and 2 that do not use an electrolyte selected from acids, bases, and salts, the conductivity was remarkably lowered, and the occurrence of bright spot-like failures remarkably appeared. Further, in Comparative Example 3 using phosphoric acid, since the degree of ionization of phosphoric acid itself was low, the electrical conductivity of the coating composition was remarkably lowered, and as a result, the occurrence of bright spot-like failures appeared remarkably. In Comparative Example 4, since only nitric acid, which is a strong acid, was used, the pH dropped significantly, and there was a problem in terms of corrosion resistance and handling in the production process.

The coating composition of the present disclosure is suitable for a wide range of technical fields in which image defects typified by bright spot failures are suppressed and high quality in appearance is required. For example, an optical lens, an optical filter, a surveillance camera, a sign Or a light-incident-side member (front glass, lens, etc.) of a solar cell module, a protective film provided on a light-irradiation-side member (diffusion glass, etc.) of a lighting device, an antireflection film, and a thin film transistor for various displays It is suitably used for a flattening film for (TFT).

The disclosure of Japanese Patent Application No. 2017-110450 filed on June 2, 2017 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually stated to be incorporated by reference, Incorporated herein by reference.

Claims

It contains polymer particles, an inorganic oxide precursor, an electrolyte selected from acids, bases and salts, and water, has a pH of 4 to 10 at 25 ° C., and an electrical conductivity of 1 mS at 25 ° C. / M or more of the coating composition.
The coating composition according to claim 1, wherein the conductivity is 5 mS / m to 70 mS / m.
The coating composition according to claim 1 or 2, wherein the electrolyte is an ammonium salt.
The inorganic oxide precursor contains at least one compound selected from a hydrolyzable silane compound represented by the following formula (1) and a partial hydrolysis condensate of the hydrolyzable silane compound: The coating composition according to claim 3.
Formula (1): R 1 —Si (OR 2 ) 3
In the formula (1), R 1 represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluorinated alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms, and R 2 represents It represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
The coating composition according to claim 4, wherein the partially hydrolyzed condensate of the hydrolyzable silane compound contains at least one unit selected from the following formula (2), formula (3) and formula (4). .
Formula (2): R 1 —Si (OR 2 ) 2 O 1/2 unit Formula (3): R 1 —Si (OR 2 ) O 2/2 unit Formula (4): R 1 —Si—O 3 / 2 units In the formulas (2), (3) and (4), each R 1 independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluorinated alkyl group having 1 to 8 carbon atoms, Alternatively, it represents an alkoxy group having 1 to 8 carbon atoms, and each R 2 independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
The coating composition according to any one of claims 1 to 5, wherein the electrolyte content is 0.001 mol / L to 0.5 mol / L in terms of molar concentration.
The coating composition according to any one of claims 1 to 6, which is used for coating formation of the cured film of a laminate having a substrate having a concavo-convex structure on the surface and a cured film.
Applying a coating composition according to any one of claims 1 to 7 on a substrate with a roll coater to form a coating film;
Drying the coating film;
Baking the coating film that has undergone the drying step to obtain a cured film; and
The manufacturing method of the laminated body which has this.
The method for producing a laminate according to claim 8, wherein the average film thickness of the cured film is 80 nm to 200 nm.
The method for producing a laminate according to claim 8 or 9, wherein the substrate is a glass substrate.
The method for producing a laminate according to any one of claims 8 to 10, wherein the substrate has a concavo-convex structure on a surface thereof.
The method for producing a laminate according to any one of claims 8 to 11, wherein in the roll coater, a surface material of a roll for applying the coating composition on a surface of the substrate is rubber.