JP2017031325A - Aqueous coating liquid, film and manufacturing method therefor, laminate and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous coating liquid capable of forming a film excellent in antireflection property, scratch resistance and antifouling property, a film and a manufacturing method therefor, a laminate and a solar cell module.SOLUTION: There are provided an aqueous coating liquid containing water, a silica particle with average primary particle diameter of 100 nm or less and a binder precursor which is a salt of a compound containing at least one kind of trivalent element and pentavalent element which dissociate in a solution containing water and has molecular weight of 600 or less, a film using the aqueous coating liquid and a manufacturing method therefor and an application thereof.SELECTED DRAWING: None

Description

  The present invention relates to an aqueous coating solution, a film and a method for producing the same, a laminate, and a solar cell module.

  The aqueous coating solution containing silica fine particles uses a solvent containing water, and is used for various applications because the formed film has low surface energy and excellent transparency. Examples of the application include an antireflection film, an optical lens, an optical filter, a flattening film for a thin film transistor (TFT) of various displays, a dew condensation prevention film, an antifouling film, and a surface protective film. Among these, the antireflection film and the antifouling film are useful because they can be used for protective films for solar cell modules, surveillance cameras, lighting equipment, signs, and the like.

In recent years, various proposals have been made on aqueous coating liquids containing silica fine particles used for applications such as antifouling films.
For example, as an antifouling coating liquid that can be uniformly applied to the surface of a coating film having a water repellent property, it contains silica fine particles, water, a surfactant as essential components, and alcohol. An antifouling coating liquid that does not substantially contain has been proposed (see, for example, Patent Document 1).
In addition, as an antifouling agent having an excellent antifouling effect on a hard surface and having an easy washing effect, a positively charged silica-based compound having an average particle diameter of 1 to 100 nm and water is proposed. (For example, refer to Patent Document 2).

Japanese Patent No. 2010-138358 Japanese Patent Laid-Open No. 2002-3820

By the way, not only antifouling properties but also antireflection properties and scratch resistance are required for protective films such as solar cell modules and surveillance cameras that are installed outdoors and used for a long period of time.
However, although the coating film surface formed using the antifouling coating liquid described in Patent Document 1 has sufficient antifouling properties, the antireflection property and scratch resistance were not sufficient. Moreover, although the coating-film surface formed using the antifouling agent of patent document 2 has sufficient antifouling property, it was inferior to antireflection property and scratch resistance.
That is, in reality, a film excellent in all of antireflection properties, scratch resistance, and antifouling properties has not been provided.

The present invention has been made in view of the above circumstances, and a problem in one embodiment of the present invention is to provide an aqueous coating liquid that can form a film excellent in antireflection properties, scratch resistance, and antifouling properties. There is to do.
Moreover, the subject of another embodiment of this invention is providing the film | membrane excellent in antireflection property, scratch resistance, and antifouling property, its manufacturing method, a laminated body, and a solar cell module.

Means for solving the problems include the following embodiments.
[1] A salt of a compound containing water, silica particles having an average primary particle size of 100 nm or less, and a trivalent element dissociating in a solution containing water and at least one pentavalent element, and having a molecular weight And an aqueous coating solution containing a binder precursor having a molecular weight of 600 or less.

[2] The aqueous coating according to [1], wherein at least one of a trivalent element and a pentavalent element that dissociates in a solution containing water is at least one selected from aluminum, phosphorus, chromium, and iron. liquid.
[3] The aqueous coating solution according to [1] or [2], wherein the content ratio of the binder precursor to the silica particles in the aqueous coating solution is 0.0050 or more and 0.0525 or less by mass ratio.
[4] The aqueous coating liquid according to any one of [1] to [3], wherein the average primary particle diameter of the silica particles is 1 nm to 50 nm.
[5] The aqueous coating solution according to any one of [1] to [4], wherein the content ratio of the binder precursor to the silica particles in the aqueous coating solution is 0.0100 or more and 0.0350 or less.
[6] The aqueous coating solution according to any one of [1] to [5], wherein the surface of the silica particles is negatively charged.
[7] The aqueous coating solution according to any one of [1] to [6], wherein the pH is 8 or more and 12 or less.

[8] A coating film forming step of forming a coating film by applying the aqueous coating solution according to any one of [1] to [7] on a substrate, and a coating for drying the formed coating film A film drying process.
[9] The method for producing a film according to [8], further including a coating film baking step of baking the dried coating film at a temperature of 150 ° C. or higher and 400 ° C. or lower after the coating film drying step.

[10] The method according to [8], further including a coating film baking step of baking the dried coating film at a temperature of 150 ° C. to 400 ° C., wherein the coating film drying step and the coating film baking step are performed in one step. Manufacturing method of the film.
[11] The coating film that has undergone at least the coating film drying step has an absolute value of an average reflectance change ΔR of 2.0% at 5 ° incidence in light having a wavelength of 400 nm to 1100 nm as defined by the following formula (1): The method for producing a film according to any one of [1] to [10] as described above.
| Average reflectance change ΔR | = | _{Average reflectance of base material after} R _{film formation−Average reflectance of} R _{base material} | Formula (1)

  [12] The method for producing a film according to [11], wherein the absolute value of the average reflectance change ΔR is 2.5% or more.

[13] Silica particles having an average primary particle size of 100 nm or less and at least one of trivalent elements and pentavalent elements, and adjacent silica particles are composed of trivalent elements and pentavalent elements. A film having voids formed to be fixed to each other via at least one kind.
[14] The film according to [13], wherein the film thickness is 50 nm or more and 350 nm or less.

[15] A laminate having the film according to [13] or [14] on a substrate.
[16] The laminate according to [15], wherein the substrate is a glass substrate.
[17] A solar cell module comprising the laminate according to [15] or [16].

According to one embodiment of the present invention, it is possible to provide an aqueous coating solution that can form a film excellent in antireflection properties, scratch resistance, and antifouling properties.
Moreover, according to another embodiment of this invention, the film | membrane excellent in antireflective property, scratch resistance, and antifouling property, its manufacturing method, a laminated body, and a solar cell module can be provided.

  Hereinafter, specific embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention. .

In the present specification, a numerical range indicated using “to” means a range including the numerical values described before and after “to” as a minimum value and a maximum value, respectively.
In this specification, the amount of each component in the composition is the total amount 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.

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

[Aqueous coating solution]
The aqueous coating liquid of the present embodiment includes water, silica particles having an average primary particle size of 100 nm or less,
A binder precursor having a molecular weight of 600 or less, which is a salt of a compound containing at least one of a trivalent element and a pentavalent element that dissociates in a solution containing water.
According to the aqueous coating liquid, it is possible to form a film having good antireflection properties, scratch resistance, and antifouling properties.

Since the aqueous coating solution contains silica particles having an average primary particle size of 100 nm or less, a film having excellent hydrophilicity and antireflection properties can be formed. Furthermore, the binder precursor is a salt of a compound containing at least one of a trivalent element and a pentavalent element that dissociates in a solution containing water, and includes a binder precursor having a molecular weight of 600 or less.
Silica particles play a role as fillers, and the hydroxyl groups on the surface of the particles act to contribute to hydrophilicity. Therefore, the film formed of the aqueous coating solution containing silica particles has good surface hydrophilicity and excellent antifouling properties.
The binder precursor used in the aqueous coating solution of the present embodiment is a salt of a compound having a relatively low molecular weight, strong inorganicity, and high ionicity. For this reason, the salt of the compound is dissociated in the aqueous coating solution, and the ions of the trivalent element and pentavalent element are adsorbed on the surface of the silica particles in the dissociated state, so that undesired silica particles in the aqueous coating solution Aggregation can be suppressed. In addition, it is estimated that the binder derived from the binder precursor has a dense bond network derived from trivalent elements and pentavalent elements, and can firmly bond silica particles even in a small area. Is done.
That is, when an aqueous coating solution is applied onto a substrate and dried, the silica particles are strongly bonded to each other by a binder having a high inorganicity and a dense bonding network derived from the binder precursor. The binder existing between the formed silica particles is a very thin layer, and the silica particles are fixed in a small area close to the point adhesion with the adjacent particles, and fixed between the silica particles with a conventional organic binder. A film having a larger void is formed than in the case of the above. It is considered that the antireflection property of the film is superior to the conventional product due to the silica particles having high antireflection properties and the wide gaps between the silica particles in the film.
Further, even when the amount of the binder is small, adjacent silica particles are firmly bonded to each other, and as a result, the formed film is considered to have good scratch resistance.
Note that the present embodiment is not limited to the above-described estimation mechanism.

  In the present specification, “high ionicity” of a salt of a compound means both low ionization energy, ie, high cationicity, and high electronegativity, ie, high anionicity. It is used in the meaning including. A salt of a compound containing a tetravalent element, for example, a salt of a compound containing a trivalent element is lower in ionization energy than a salt of sodium silicate, and a salt of a compound containing a pentavalent element has an electronegativity. From a higher point, it is considered that since the ionicity is high, the ease of adsorption onto silica particles is further improved.

-Silica particles-
The aqueous coating liquid of this embodiment contains silica particles having an average primary particle diameter of 100 nm or less. Silica particles have a function of further exerting hydrophilicity while enhancing the physical resistance of a film formed by an aqueous coating solution. That is, the silica particles contribute to the hydrophilic expression of the film formed by the action of hydroxy groups on the particle surface.
The silica particles contained in the aqueous coating solution can be used without particular limitation as long as the average primary particle diameter is 100 nm or less.
Examples of silica particles that can be used in the aqueous coating solution of the present embodiment include hollow silica particles, porous silica particles, and nonporous silica particles. Examples of the shape of the silica particles include a spherical shape, a plate shape, a needle shape, and a bead shape.
The silica particles may be surface-treated silica particles whose surface is treated with an aluminum compound or the like. From the viewpoint of the antifouling property of the formed film, it is preferable to select an agent that does not inhibit the surface hydrophilicity of the silica particles.

If the average primary particle diameter of the silica particles exceeds 100 nm, undesirable light scattering is likely to occur, and the transparency and antireflection properties of the formed film may be reduced. Therefore, in this embodiment, the average primary particles Silica particles having a diameter of 100 nm or less are used.
The average primary particle size of the silica particles is preferably 50 nm or less, and more preferably 30 nm or less. Moreover, it is preferable that an average primary particle diameter is 1 nm or more from a viewpoint that aggregation of silica particles is suppressed more effectively. That is, the average primary particle diameter of the silica particles is preferably 1 nm or more and 50 nm or less.
When the film formed using the aqueous coating liquid of the present embodiment is used for, for example, an antireflection layer of a security camera cover, a cover for various sensors installed outdoors, the antireflection property is better. From the point of view, the average primary particle diameter of the silica particles is preferably 1 nm or more and 50 nm or less. When the film formed using the aqueous coating liquid of the present embodiment is used for, for example, a protective layer of a solar cell module, a protective layer of an automobile exterior member, etc., it has better scratch resistance and durability. From the viewpoint that it can be achieved, the average primary particle diameter of the silica particles is preferably 8 nm or less, more preferably 6 nm or less, and further preferably 2 nm or more and 4 nm or less.
Since the average primary particle diameter of the silica particles contained in the aqueous coating liquid is finer, in the film formed using the aqueous coating liquid, the silica particles are densely arranged to form a dense film with high hardness. It is considered that the scratch resistance of the film is improved. In addition, a dense film in which silica particles are densely arranged has a smooth film surface, so that the antifouling property of the formed film is considered to be more excellent.

  The average primary particle diameter of the silica particles can be obtained from an image of a photograph taken by observing the silica particles dispersed in 1-methoxy-2-propanol with a transmission electron microscope. Specifically, it was obtained by measuring the projected area of the silica particles from the image of the transmission electron micrograph, obtaining the equivalent circle diameter from the measured projected area, and arithmetically averaging the obtained equivalent circle diameter value. The value is the average primary particle diameter of the silica particles. In the present specification, the average primary particle diameter of the silica particles is obtained by measuring the projected areas of 300 silica particles, obtaining the equivalent circle diameters from the measured projected areas, and arithmetically averaging the obtained equivalent circle diameter values. The value obtained by is adopted.

The silica particles contained in the aqueous coating solution are preferably nonporous silica particles from the viewpoint of improving the scratch resistance of the formed film.
“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. In the present specification, the “nonporous silica particles” have a core such as a polymer inside the particles, and the outer shell (shell) of the core is silica or a silica precursor (for example, silica by firing). Silica particles having a core-shell structure composed of a changing material) are not included.

In the coating film formed with the aqueous coating solution, the nonporous silica particles are a state where each nonporous silica particle is aggregated into a single particle (aggregated by van der Waals force). After the coating film is dried, at least some of the non-porous silica particles adjacent to each other are connected to each other via a binder and fixed. Exists.
Since the silica particles contained in the aqueous coating liquid are nonporous silica particles, the hardness of the film is increased and the scratch resistance is further improved.

  As the silica particles, commercially available products may be used as long as the average primary particle diameter is 100 nm or less. Examples of commercially available products include NALCO (registered trademark) 8699 (aqueous dispersion of nonporous silica particles, average primary particle size: 3 nm, solid content: 15% by mass, manufactured by NALCO), NALCO (registered trademark) 1130 ( Aqueous dispersion of nonporous silica particles, average primary particle size: 8 nm, solid content: 30% by mass, manufactured by NALCO, Snowtex (registered trademark) XS (aqueous dispersion of nonporous silica particles, average primary particles) Diameter: 5 nm, solid content: 20% by mass, manufactured by Nissan Chemical Co., Ltd.). These commercially available products can be selected and used according to the purpose.

  The aqueous coating solution may contain only one type of silica particles or two or more types of silica particles. When two or more types of silica particles are contained, the silica particles can be arbitrarily selected according to the purpose, such as particles having different sizes or particles having different shapes.

The content of the silica particles is preferably 64% by mass to 95% by mass and more preferably 70% by mass to 95% by mass with respect to the total solid content of the aqueous coating liquid.
Moreover, 30 mass% or less is preferable with respect to the aqueous coating liquid whole quantity, 20 mass% or less is more preferable, and 10 mass% or less is further more preferable.
The content of silica particles indicates the total amount when the aqueous coating solution contains two or more types of silica particles.
When the content of the silica particles is within the above range, the dispersibility of the silica particles in the aqueous coating solution is enhanced, which is advantageous in preventing aggregation and the like. Further, the scratch resistance of the film formed using the aqueous coating solution becomes better, and a more excellent planar film can be formed.

The silica particles contained in the aqueous coating solution are preferably negatively charged on the surface.
Silica particles whose surface is negatively charged have better dispersion stability in an aqueous coating solution, and as a result, coating accuracy is further improved and the coated surface is improved. For this reason, the film formed of the aqueous coating solution has better antireflection properties and further improves the surface appearance.
In addition, since the surface of the silica particles is negatively charged, the surface of the film formed by the aqueous coating solution is also negatively charged, dirt is less likely to adhere, and the antifouling property of the film becomes better.
The charged state of the silica particles contained in the aqueous coating solution can be confirmed by measuring the Zeda potential. Specifically, the aqueous coating solution is appropriately diluted with deionized water while maintaining the pH, and the Zeda potential is measured for the obtained diluted aqueous coating solution, and the measurement result is negative. Is assumed that the silica particles are charged “negative”, and if the measurement result is positive, the silica particles are charged “positive”. For example, a Zeda potential measurement system (model number: ELSZ-1, manufactured by Otsuka Electronics Co., Ltd.) can be used as the Zeda potential measurement device.

-Binder precursor-
The aqueous coating liquid of this embodiment is a salt of a compound containing at least one of a trivalent element and a pentavalent element that dissociates in a solution containing water, and has a molecular weight of 600 or less. Hereinafter, it may be simply referred to as “binder precursor”.
When the binder precursor contains a salt of a compound containing at least one of a trivalent element and a pentavalent element, the salt dissociates in the aqueous coating solution, and ions containing a trivalent or pentavalent element are produced. When the generated ions are adsorbed and coated on the surface of the silica particles, undesired aggregation of the silica particles in the aqueous coating liquid can be suppressed.
By drying the coating film formed by applying the aqueous coating solution, the solvent containing water is removed from the binder precursor, and at least one of a trivalent element and a pentavalent element is applied by applying thermal energy. Are bonded to each other to form a multimer such as a dimer or a trimer, whereby a bonded network of inorganic compounds is formed between the silica particles. As a result, the formed dense bonded network is formed into a binder. It is considered that the silica particles can be firmly bonded to each other.

  The binder precursor has a molecular weight of 600 or less. In a relatively high molecular weight compound having a molecular weight of over 600, even if it contains a trivalent element and a pentavalent element, it is difficult to form a multimer by the reaction as described above depending on the application of thermal energy, and it is strong. Binder formation cannot be expected. The molecular weight of the binder precursor is preferably 450 or less, and preferably 300 or less because the formation reaction of multimers caused by the trivalent element and the pentavalent element more easily proceeds. Since formation can be expected, it is preferable.

  Examples of at least one of the trivalent element and pentavalent element include at least one selected from aluminum, phosphorus, chromium, and iron. Any of the elements described above is preferably used in the aqueous coating solution of the present embodiment. The bond network formed by at least one element selected from trivalent or pentavalent elements such as aluminum, phosphorus, chromium, and iron is compared with the case where a tetravalent element such as silicon is used. It becomes denser and silica particles can be bonded more firmly.

Examples of the salt of the compound containing at least one of trivalent element and pentavalent element include aluminum metaphosphate, aluminum phosphate, sodium tripolyphosphate, lithium phosphate, magnesium phosphate, aluminum sulfate, aluminum silicate, and silicic acid. Examples include sodium aluminum (zeolite A), potassium chromate, potassium dichromate, and iron (III) phosphate. From the viewpoint of the effect, there are a plurality of reaction sites that contribute to the formation of the multimer, as the element, aluminum metaphosphate with phosphorus and aluminum with a plurality of trivalent and pentavalent elements. This is preferable because a stronger bond network is formed.
The aqueous coating solution of the present embodiment may contain only one kind of the salt of the compound described above, or may contain two or more kinds.
A salt of a compound containing at least one of a trivalent element and a pentavalent element that dissociates in a solution containing water is a strong bond network when a compound having a molecular weight of 600 or less, such as aluminum metaphosphate, is used. According to the study of the present inventors, the aluminum phosphate having a molecular weight exceeding 600 does not form a bond network even by the same operation, and the silica particles by the binder are formed. The strong bond was not formed.
The salt content of the compound containing at least one of trivalent and pentavalent elements as a binder precursor in the aqueous coating solution is connected to a capillary column having an inner diameter of 1 mm or less using a microflow pump. It can be measured by a measuring method using high performance liquid chromatography after feeding.

The content of the binder precursor is preferably 0.0050 or more and 0.0525 or less, and 0.0100 or more and 0.0350 or less in terms of mass ratio with respect to the content of silica particles contained in the aqueous coating solution. It is more preferable.
That is, by using the aqueous coating liquid of this embodiment, strong bonding can be achieved even in a ratio where the content of the binder precursor is extremely small with respect to the content of silica particles.
In general, for example, an organic binder such as tetraethoxysilane has a mass ratio of about 0.0530 or more with respect to the content of silica particles in order to bond silica particles firmly. In order to achieve a strong bond between the silica particles, for example, heating at a high temperature of 180 ° C. or higher is necessary. However, if the binder precursor described above is used, it is strong even at a temperature of about 150 ° C. A strong connection network is formed.

-Water-
The aqueous coating liquid of this embodiment contains water.
By using water as the aqueous medium of the aqueous coating solution, the burden on the environment is greatly reduced as compared with a coating solution using a large amount of a volatile organic solvent.
The water used for the aqueous coating solution is preferably deionized water or ion-exchanged water that does not contain impurities or has the content of impurities reduced as much as possible.
The content of water contained in the aqueous coating solution is preferably 50% by mass or more, more preferably 65% by mass or more, and more preferably 80% by mass or more with respect to the total amount of liquid components in the aqueous coating solution. More preferably it is.

-Other ingredients-
The aqueous coating liquid of the present embodiment may contain components other than silica particles having an average primary particle size of 100 nm or less, a binder precursor, and water depending on the purpose within a range that does not impair the effects of the present embodiment. Other components that can be optionally contained in the aqueous coating solution may be hereinafter referred to as “other components”.
Examples of other components that can be used in this embodiment include a surfactant, a hydrophilic organic solvent, a water-soluble polymer, and a water-dispersed latex.

(Surfactant)
The aqueous coating solution of the present embodiment can contain a surfactant for the purpose of improving the coating property of the aqueous coating solution and improving the effect of suppressing the aggregation of silica particles.
The surfactant can be selected and used according to the purpose of use of the aqueous coating solution.
As the surfactant, a nonionic surfactant is preferably used from the viewpoint of not impairing the dispersibility of the hydrophilic silica particles in the aqueous coating solution.

(Polyol type nonionic surfactant)
The aqueous coating liquid of this embodiment may contain a polyol type nonionic surfactant.
For example, a polyol-type nonionic surfactant having a property that it is difficult to adsorb on the surface of silica particles can reduce the surface tension of an aqueous coating solution in a small amount without reducing the dispersibility of silica particles. By using a polyol type nonionic surfactant for the coating solution, it is considered that the wettability of the aqueous coating solution to the substrate becomes better. By improving the wettability of the aqueous coating solution, the uniformity of the formed coating film is increased, and the surface shape of the film after heating is improved, and the formed film has better antireflection properties. It is thought that it will become a thing.

“Polyol type nonionic surfactant” is a surfactant having a plurality of hydroxyl groups, which does not contain an ion-dissociating moiety such as an anionic surfactant, a cationic surfactant, and an amphoteric surfactant. is there. Examples of the polyol type nonionic surfactant include sorbitan fatty acid ester, sucrose fatty acid ester, alkyl polyglucoside having a cyclic polyether structure as a hydrophilic group. Moreover, the glycerin fatty acid ester which does not have a cyclic polyether structure, the alkyl fatty acid ester of polyglycerol, the alkyl glyceryl ether, sorbitol, etc. are mentioned.
Among these, as the polyol type nonionic surfactant, a nonionic surfactant having a cyclic polyether as a hydrophilic group is preferable from the viewpoint that a better planar film can be formed. Furthermore, as a polyol type nonionic surfactant, alkylpolyglucoside is more preferable from the viewpoint that a film having better antireflection properties and antifouling properties can be formed.

The number of carbon atoms in the alkyl chain of the alkylpolyglucoside is preferably 5 to 20, more preferably 6 to 14, and still more preferably 8 to 14. The alkyl chain of the alkylpolyglucoside may be linear or branched. The average degree of polymerization of glucoside is preferably from 1 to 10, and more preferably from 1 to 5. Specific examples of the alkyl polyglucoside include decyl glucoside and octyl glucoside.
The weight average molecular weight of the alkylpolyglucoside is preferably 100 to 2000, and more preferably 100 to 1000.

  A commercially available product may be used as the polyol type nonionic surfactant. Examples of commercially available products include TRITON (registered trademark) BG-10 (alkyl polyglucoside surfactant, manufactured by Dow Chemical), Mydol (registered trademark) 10, 12 (alkyl polyglucoside surfactant, Kao ( ), Rheodor (registered trademark) SP-P10 (Sorbitan fatty acid ester surfactant, manufactured by Kao Corporation), Riquemar (registered trademark) L-71-D (diglycerin fatty acid ester surfactant, RIKEN vitamin ( Co., Ltd.), Exel (registered trademark) 95N (glycerin fatty acid ester, manufactured by Kao Corporation), Poem (registered trademark) PR-100 (alkyl glyceryl ether, manufactured by Riken Vitamin Co., Ltd.), DK Ester (registered trademark) (Sucrose fatty acid ester, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

The content when the aqueous coating solution contains a polyol-type nonionic surfactant is preferably 0.07% by mass to 1.0% by mass with respect to the total mass of the aqueous coating solution, The content is more preferably from mass% to 0.8 mass%, and further preferably from 0.07 mass% to 0.5 mass%.
When the content of the polyol type nonionic surfactant in the aqueous coating liquid is within the above range, the effect of addition, that is, the surface tension of the aqueous coating liquid is lowered, the wettability is improved, and the aqueous coating liquid is used. The micelle formation inside is suppressed, and the denseness of the silica particles in the formed film can be further increased.

(Hydrophilic organic solvent)
The aqueous coating solution may contain at least one hydrophilic organic solvent having excellent affinity with water in addition to water.
When the aqueous coating solution contains a hydrophilic organic solvent, the surface tension of the aqueous coating solution becomes lower, and a more uniform coating film can be formed. Further, when the hydrophilic organic solvent is a low boiling point organic solvent, there are advantages such as easy drying of the aqueous coating solution.

  It does not specifically limit as a hydrophilic organic solvent, Methanol, ethanol, isopropanol, butanol, acetone, ethylene glycol, ethyl cellosolve etc. are mentioned. From the viewpoint of easy availability and reduction of environmental burden, the hydrophilic organic solvent is preferably alcohol, and ethanol, isopropanol and the like are more preferable.

  When the aqueous coating solution contains a hydrophilic organic solvent in addition to water as an aqueous medium, the content of water used in the aqueous coating solution is preferably 30% by mass or more based on the total mass of the aqueous medium. More preferably, it is at least mass%.

  The solid content in the aqueous coating solution is preferably 0.1% by mass to 30% by mass, more preferably 0.2% by mass to 20% by mass, based on the total mass of the aqueous coating solution. More preferably, it is 0.5 mass%-10 mass%. The solid content in the aqueous coating solution can be adjusted by the content of the solvent, particularly water.

(PH of aqueous coating solution)
The pH of the aqueous coating solution is preferably 8 to 12, and more preferably 9 to 11.
By setting the pH of the aqueous coating solution to 8 to 12, it is considered that the aggregation of silica particles in the aqueous coating solution is suppressed, the dispersibility of the silica particles becomes better, and the coating accuracy is improved.
In particular, when silica particles whose surface is negatively charged are used, the isoelectric point of the silica particles whose surface is negatively charged is pH 4 to 6, and pH 8 to 12, which is a preferable pH of the aqueous coating solution, is. By being different from each other, it is considered that aggregation of fine silica particles is suppressed and the dispersibility of the silica particles becomes better.
By improving the coating accuracy of the aqueous coating solution, it is considered that the uniformity and surface shape of the film formed by the aqueous coating solution are improved, and in particular, it is easy to form a film with better antireflection properties.
When the pH of the aqueous coating solution is 8 to 12, aggregation of silica particles in the aqueous coating solution is suppressed, and a good planar film is formed. Therefore, a film excellent in antireflection property, scratch resistance, and antifouling property is formed by the aqueous coating solution. Moreover, the long-term stability fall of the aqueous coating liquid resulting from the melt | dissolution of the surface of the silica particle which arises when pH is too high, and the damage of a silica particle is suppressed, and the dispersion stability of the silica particle in an aqueous coating liquid improves more.

The isoelectric point of the silica particles varies slightly depending on the production method of the silica particles, the primary particle diameter, the surface state of the silica particles, etc., but in this case, the pH of the aqueous coating solution is adjusted to the pH of the isoelectric point of the silica particles. May be adjusted.
The pH of the aqueous coating solution in this specification is a value measured at 25 ° C. using a pH meter (model number: HM-31, manufactured by Toa DKK Co., Ltd.).

[Membrane production method]
Next, the manufacturing method of the film | membrane using the aqueous coating liquid as stated above is demonstrated.
The film manufacturing method of the present embodiment includes a coating film forming step of forming a coating film by applying the above-described aqueous coating liquid on a substrate, a coating film drying step of drying the formed coating film, including.
The aforementioned aqueous coating liquid is a salt of a compound containing water, silica particles having an average primary particle size of 100 nm or less, and at least one trivalent or pentavalent element that dissociates in a solution containing water, And the aqueous coating liquid containing the binder precursor whose molecular weight is 600 or less.

The film production method of the present embodiment preferably includes a coating film baking step of baking the dried coating film at a temperature of 150 ° C. or higher and 400 ° C. or lower after the coating film drying step.
The film manufacturing method of the present embodiment may include other steps as necessary within a range not impairing the effects of the present embodiment.

  In the film production method of the present embodiment, at least of water, silica particles having an average primary particle size of 100 nm or less, and a trivalent element and a pentavalent element that dissociate in a solution containing water. A coating film is formed by applying an aqueous coating solution containing a binder precursor having a molecular weight of 600 or less, which is a salt of a compound containing one kind, and then drying the formed coating film, A film having excellent antireflection properties, scratch resistance and antifouling properties can be obtained.

The reason why the film obtained by the manufacturing method of the present embodiment can achieve the effects as described above is not clear, but the present inventors presume as follows.
The binder precursor used in the aqueous coating liquid of the present embodiment contains a salt of a compound containing a trivalent element and a pentavalent element having strong inorganicity and high ionicity. The salt of the compound is dissociated in the aqueous coating solution and adsorbed on the surface of the silica particles. The ions adsorbed on the silica particles are multivalent ions derived from at least one of a trivalent element and a pentavalent element. Therefore, the binder precursor has more reaction sites and an odd number of reaction sites than when monovalent, divalent, or tetravalent ions are adsorbed. By heating at the time of removing the medium, not only adsorption to the silica particles but also ions covering the silica particles react with each other to easily form a multimer. Therefore, it is presumed that the binder obtained from the binder precursor has a dense bond network and can firmly bond the silica particles even in a small area.
The formed binder is a very thin layer, so silica particles are fixed in a small area close to point adhesion with adjacent particles, and than when fixed by a conventional organic binder between silica particles. However, a film having a larger void is formed. For this reason, the antireflection property of the film becomes better.
Moreover, even if the amount of the binder is small due to the physical properties of the binder, adjacent silica particles are firmly bonded to each other, and as a result, the formed film is considered to have good scratch resistance.
Furthermore, the silica particles are coated with the polyvalent ions derived from the binder precursor in the aqueous coating solution, so that the aggregation of the silica particles is suppressed, the dispersibility of the silica particles is improved, and the coating accuracy of the aqueous coating solution is improved. Therefore, the formed film is considered to have excellent antireflection properties.

  Hereafter, each process in the manufacturing method of the film | membrane of this embodiment is demonstrated in detail. Details of components used in each step will be described later.

[Coating film forming process]
In the coating film forming step, a compound containing at least one of water, silica particles having an average primary particle diameter of 100 nm or less, a trivalent element and a pentavalent element dissociating in a solution containing water is formed on the substrate. In this step, a coating film is formed by applying an aqueous coating solution containing a salt and a binder precursor having a molecular weight of 600 or less.
In the coating film forming process, as described above, due to the presence of the binder precursor, the dispersion and dispersion stability of the silica particles in the aqueous coating liquid are good, so the coating film is formed with good coating accuracy. I think it can be done.

The coating amount of the aqueous coating solution is not particularly limited, and can be appropriately set in consideration of operability and the like according to the solid content concentration in the aqueous coating solution, the desired film thickness, and the like.
The coating amount of the base material in the aqueous coating solution is generally ^is preferably ^{0.1mL / m 2 ~1000mL / m 2} , more preferably ^{1mL / m 2 ~100mL / m 2} , further preferably ^{1mL / m 2 ~50mL / m 2} . When the coating amount of the aqueous coating solution is within the above range, the coating accuracy is good, and a film having better antireflection properties can be formed.

  The method for applying the aqueous coating solution on the substrate is not particularly limited. As a coating method, any known coating method such as spray coating, brush coating, roller coating, bar coating, dip coating, or the like can be applied.

<Base material>
In the film manufacturing method of the present embodiment, the substrate on which the aqueous coating solution is applied is not particularly limited.
Examples of the substrate include substrates such as glass, resin, metal, ceramic, and composite materials thereof, and any of these substrates can be suitably used. Among these, a glass substrate is preferable as the substrate. When a glass substrate is used as the substrate, the condensation through the binder of hydroxy groups in the glass substrate is not only between the hydroxy groups of the silica particles but also between the hydroxy groups of the silica particles and the hydroxy groups of the glass surface. However, since it generate | occur | produces, the coating film excellent in adhesiveness with a base material can be formed.

[Coating film drying process]
The coating film drying step is a step of drying the coating film formed in the previous step.
In the coating film drying step, by drying the coating film formed by applying an aqueous coating solution, the silica particles are partially immobilized on the substrate via the binder formed by the binder precursor. A film is formed. Silica particles are fixed to each other via an inorganic binder, so that voids are generated between the silica particles, and the dried coating film is a film with excellent antireflection properties combined with the characteristics of the silica particles. It is considered to be.
In addition, in the coating film drying process, the coating film formed in the coating film forming process is accurately applied and the coating film formed more uniformly is dried. Therefore, the coating film after drying has a uniform thickness and excellent antireflection. It becomes a film with excellent properties.
In the coating film drying step, moisture in the aqueous coating solution is removed, so that a dense multimer of elements formed by a binder precursor containing a trivalent element and a pentavalent element is present between the silica particles. There is a binder in the binding network, silica particles are firmly bonded to each other through the binder, a dense film containing voids is formed between the silica particles, and a dry film with higher antireflection properties and hardness is formed, reflecting It is considered that a film having excellent scratch resistance as well as prevention can be obtained. Moreover, since the film becomes dense and the film surface becomes smooth, it is considered that dirt is difficult to adhere and excellent antifouling properties can be obtained.

The coating film can be dried 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 400 ° C. using the above heating device. When the coating film is dried by heating, for example, the heating time can be about 1 minute to 30 minutes.
As drying conditions for the coating film, drying conditions in which the coating film is heated at an ambient temperature of 40 ° C. to 200 ° C. for 1 minute to 10 minutes are preferable, 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 coating film thickness after drying can be appropriately selected according to the purpose of use of the film. Especially, it is preferable that the film thickness after drying is 50 nm or more. When the film thickness is 50 nm or more, the coating film after drying is more excellent in antireflection properties.
The coating film after drying preferably has a thickness of 50 nm to 350 nm, more preferably 100 nm to 300 nm, and particularly preferably 100 nm to 250 nm.

  The content of silica particles in the coating film after the coating film drying step and before the coating film baking step is 64% by mass to 95% by mass with respect to the total solid content of the coating film as described above. It is preferably 70% by mass to 95% by mass. When the content of the silica particles in the coating film after drying subjected to the coating film baking step is within the above range, a film excellent in antireflection properties, scratch resistance and antifouling properties can be formed.

[Coating film baking process]
The film manufacturing method of the present embodiment preferably includes a coating film baking step of baking the dried coating film at an ambient temperature of 150 ° C. or more and 400 ° C. or less after the above-described coating film drying step. .
The baking temperature in the coating film baking step may be a temperature exceeding 400 ° C., for example, exceeding 400 ° C. and not more than 800 ° C. However, by using the aqueous coating liquid of the present embodiment as described above, baking at an atmospheric temperature of 400 ° C. or lower further increases the hardness of the dense film formed in the coating film drying step, resulting in more scratch resistance. The anti-reflection property is remarkably improved by the formation of voids resulting from the improvement and the solid bonding of the silica particles through the binder.

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 preferably 150 ° C. or higher and 400 ° C. or lower, more preferably 150 ° C. or higher and 350 ° C. or lower, and further preferably 200 ° C. or higher and 300 ° C. or lower. The firing time is preferably 1 minute to 20 minutes, and more preferably 1 minute to 10 minutes.

The coating film thickness after firing can be appropriately selected according to the intended use of the film. Especially, it is preferable that the film thickness after baking is 50 nm or more. When the film thickness is 50 nm or more, the coating film after baking is more excellent in antireflection properties.
The coating film after baking preferably has a film thickness of 50 nm to 350 nm, more preferably 100 nm to 300 nm, and particularly preferably 100 nm to 250 nm.

As described above, in the film manufacturing method of the present embodiment, the baking temperature is preferably 150 ° C. or higher and 400 ° C. or lower, and the baking temperature range includes the drying temperature range. For this reason, the manufacturing method of the film | membrane of this embodiment can perform the coating film drying process and the coating film baking process performed after the coating film drying process if needed in one process.
When the coating film drying step and the coating film baking step are performed in one step, the heating condition is preferably 150 ° C. or more and 400 ° C. or less, more preferably 180 ° C. or more and 350 ° C. or less, and 200 ° C. More preferably, it is 300 degrees C or less. The firing time is preferably 1 minute to 30 minutes, and more preferably 1 minute to 150 minutes.

[Other processes]
The film manufacturing method of the present embodiment may include other steps as necessary within a range not impairing the effects of the present embodiment.
Examples of other processes include a cleaning process, a surface treatment process, and a cooling process.

[Absolute value of average reflectance change ΔR]
The coating film after at least the coating film drying step has its antireflection performance based on the absolute value of the average reflectance change ΔR at the time of 5 ° incidence in light having a wavelength of 400 nm to 1100 nm, which is defined by the following formula (1). Can be represented.
The “coating film after having undergone at least the coating film drying process” may be a coating film that has undergone the above-described coating film drying process, and a film or coating that has undergone only the coating film drying process after the coating film forming process. After the film drying step, the coating film further subjected to the above-described coating film baking step, and the coating film after the coating film drying step and the coating film baking step are performed in one step are included.

| Average reflectance change ΔR | = | _{Average reflectance of base material after} R _{film formation−Average reflectance of} R _{base material} | Formula (1)

The average reflectance change ΔR in the formula (1) is the average reflectance of the base material on which the coating film is not formed (average reflectance of the R _{base material} ) and the average reflection of the base material having the coating film formed with the aqueous coating liquid. The rate ( _{average reflectance of the base material after the} R _{film is formed} ) can be determined by measuring a white barium sulfate plate as a reference.

The reflectance can be measured by using a spectrophotometer with an integrating sphere. In this specification, an ultraviolet-visible infrared spectrophotometer (model number: UV3100PC, manufactured by Shimadzu Corporation) is used as a measuring device, and the reflectance in light having a wavelength of 400 nm to 1100 nm is measured using an integrating sphere. A value obtained by arithmetically averaging the reflectance values at the respective wavelengths is adopted as the average reflectance.
The higher the absolute value of the average reflectance change ΔR, the better the antireflection property of the film.

  At least the absolute value of the coating film average reflectance change ΔR after drying is preferably 2.0% or more, and more preferably 2.5% or more, from the viewpoint of antireflection properties.

[film]
The film of the present embodiment includes silica particles having an average primary particle size of 100 nm or less and at least one of a trivalent element and a pentavalent element. Adjacent silica particles are composed of a trivalent element and a pentavalent element. It is a film | membrane which has the space | gap formed mutually fixed through at least 1 sort (s) of these elements.
In the membrane of this embodiment. The presence of voids between the silica particles can be confirmed by electron microscope analysis from the cross-sectional direction of the film. In this embodiment, the silica particles are firmly fixed even when heated at a temperature of 400 ° C. or lower. For example, when spherical silica particles are used, there is no deformation due to heating, and the silica particles Since the amount of the binder containing at least one of a trivalent element and a pentavalent element existing between them is extremely small, it is possible to confirm an appearance such that spherical silica particles are point-bonded to each other.

The presence of at least one of trivalent and pentavalent elements between the silica particles can be confirmed by X-ray photoelectric spectroscopy analysis from the cross-sectional direction of the film.
For example, a film formed by bonding between silica particles via a silicon compound such as alkoxysilane contains a silicon compound between the silica particles when the film is observed by electron microscopic analysis from the cross-sectional direction of the film described above. The presence of the binder layer can be confirmed, and voids having a smaller volume than the voids between the silica particles of this embodiment are observed. Moreover, although the presence of silicon as an element can be confirmed by X-ray photoelectric spectroscopy analysis from the cross-sectional direction of the film, the presence of a trivalent element and a pentavalent element cannot be confirmed.
In addition, about said analysis method, since surface shape and an elemental analysis can be performed simultaneously by using SEM-EDX by JEOL Co., Ltd., for example, it is preferable.
A method of measuring the cross section of the membrane at a magnification of 10,000 times or more with a fracture surface generated by breaking a membrane frozen in liquid nitrogen as a measurement target is preferable.

In the film of this embodiment, the silica particles are strongly bonded via a binder, and the amount of the binder is extremely small. As a result, it has excellent antireflection properties. Furthermore, since it is a dense film with a smooth surface, it is excellent in scratch resistance and antifouling properties.
The film of the present embodiment is preferably a film produced by the film production method of the present embodiment using the aqueous coating liquid of the present embodiment described above.
The aqueous coating solution preferably used for forming the film is synonymous with the aqueous coating solution of the present embodiment described above and the aqueous coating solution in the method of manufacturing a film of the present embodiment, and the preferred embodiments are also the same.

  Below, the preferable physical property of the film | membrane of this embodiment is shown.

(Film thickness)
The film of this embodiment preferably has a thickness of 50 nm to 350 nm, more preferably 100 nm to 300 nm, and still more preferably 100 nm to 250 nm from the viewpoint of antireflection properties.

[Laminate]
The laminated body of this embodiment has the film | membrane of this embodiment as stated above on a base material.
The laminate having the film of this embodiment is excellent in antireflection properties, scratch resistance, and antifouling properties due to the characteristics of the film of this embodiment.

(Laminate base material)
The base material in the laminated body of this embodiment is not specifically limited. As the substrate, the substrate used in the film forming method of the present embodiment described above can be similarly applied.
Examples of the substrate that can be used for the laminate include substrates such as glass, resin, metal, ceramic, and composite materials thereof, and any of these substrates can be suitably used in this embodiment. Especially, as a base material, a glass base material is preferable from an adhesive viewpoint with the film | membrane of this embodiment as stated above.

  Since the laminate having the film of the present embodiment on the substrate is excellent in antireflection, scratch resistance, and antifouling properties, for example, it is used for solar cell modules, surveillance cameras, lighting equipment, protective films for signs, etc. Can be suitably used.

[Solar cell module]
The solar cell module of the present embodiment includes the laminate of the present embodiment described above.
The solar cell module of the present embodiment is excellent in antireflection, scratch resistance, and antifouling properties provided on the solar light incident side of the solar cell element that converts the light energy of sunlight into electrical energy. It may be arranged between a laminate having the above film and a solar cell backsheet represented by a polyester film.
Between the laminated body of this embodiment, and solar cell backsheets, such as a polyester film, it seals with sealing materials represented by resin, such as ethylene-vinyl acetate copolymer, for example.

  Regarding members other than the laminate and the back sheet, such as a solar battery module and a solar battery cell, for example, see “Solar power generation system constituent materials” (supervised by Eiichi Sugimoto, Industrial Research Co., Ltd., issued in 2008). Have been described. It is preferable that the solar cell module of this embodiment is provided with the laminated body of this embodiment on the side on which sunlight is incident, and other configurations other than having the laminated body of this embodiment are arbitrary.

  As a base material provided in the side which sunlight injects, transparent resin base materials, such as a glass base material and an acrylic resin, etc. can be mentioned, for example, Preferably it is a glass base material.

There is no restriction | limiting in particular as a solar cell element used for the solar cell module of this embodiment. The solar cell module of the present embodiment includes 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-arsenide, etc. Any of various known solar cell elements such as III-V group or II-VI group compound semiconductor solar cell elements can be applied.
Since the solar cell module of the present embodiment includes a laminate having a film having good antireflection properties, scratch resistance, and antifouling properties, preferably on a glass substrate, undesired reflection of sunlight is suppressed, Sunlight can be efficiently supplied to the solar cell element. For this reason, even if it is used for a long period of time, the surface film is not damaged and the decrease in light transmission due to the adhesion of contaminants is suppressed. Since it is easily removed with water such as rain due to film properties, good power generation efficiency is maintained over a long period of time.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[Example 1]
[Preparation of aqueous coating solution 1]
Aqueous dispersion of silica particles (nonporous silica particles, NALCO (registered trademark) 8699: trade name, average primary particle diameter of silica particles: 3 nm, solid content: 15% by mass, surface potential: minus (negative), NALCO (Manufactured) 0.300 parts by mass of aluminum metaphosphate (manufactured by Taihei Chemical Industrial Co., Ltd., molecular weight 263.9) was added to 89.40 parts by mass. Furthermore, 2.10 parts by mass of a polyol type nonionic surfactant (trade name: TRITON (registered trademark) BG-10, alkylpolyglucoside surfactant, solid content: 70% by mass, manufactured by Dow Chemical Company) was added. Thereafter, deionized water was added in an amount such that the total amount became 1000 parts by mass, and the aqueous coating solution 1 was prepared by stirring.
In addition, the content ratio of the binder precursor with respect to the silica particle in the aqueous coating liquid 1 is 0.0224 in mass ratio.

[Production of membrane sample 1]
The aqueous coating liquid 1 was applied onto a glass substrate using a bar coater (coating amount: 10 mL / m ^{2 to} 20 mL / m ² ) to form a coating film (coating film forming step).
The coating film was heated using an oven at an ambient temperature of 100 ° C. for 2 minutes and dried (coating film drying step). Next, the dried coating film is baked at an atmospheric temperature of 280 ° C. for 3 minutes using an electric furnace (coating film baking step), and a film sample 1 including a film formed using an aqueous coating solution on a glass substrate is obtained. Produced.
In addition, the film sample 1 was produced on the application | coating conditions from which the film thickness after drying and baking of the film | membrane formed on a glass base material will be 130 nm.

[Example 2]
[Preparation of aqueous coating solution 2]
In the preparation of the aqueous coating liquid 1, an aqueous dispersion of silica particles was prepared from Snowtex (registered trademark) 50 (trade name, average primary particle diameter of silica particles: 25 nm, solid content: 48% by mass, surface potential: minus, Nissan. Aqueous coating solution 2 was prepared in the same manner as aqueous coating solution 1 except that the amount added was changed to 27.9 parts by mass. In addition, the content ratio of the binder precursor with respect to the silica particle in the aqueous coating liquid 2 is 0.0224 in mass ratio.

[Production of membrane sample 2]
A membrane sample 2 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 2.

[Example 3]
[Preparation of aqueous coating solution 3]
In the preparation of the aqueous coating solution 1, an aqueous dispersion of silica particles was prepared by using a trade name: Snowtex (registered trademark) ZL, average primary particle diameter of silica particles: 100 nm, solid content: 40% by mass, surface potential: minus, Nissan Aqueous coating solution 3 was prepared in the same manner as aqueous coating solution 1 except that the amount was changed to 33.5 parts by mass from Chemical Industries. In addition, the content ratio of the binder precursor with respect to the silica particles in the aqueous coating liquid 3 is 0.0224 in mass ratio.

[Production of membrane sample 3]
A membrane sample 3 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 3.

[Example 4]
[Preparation of aqueous coating solution 4]
In the preparation of the aqueous coating solution 1, the aqueous coating solution was the same as the aqueous coating solution 1 except that the addition amount of aluminum metaphosphate as a binder precursor was changed from 0.300 parts by mass to 0.120 parts by mass. 4 was prepared. In addition, the content ratio of the binder precursor with respect to the silica particles in the aqueous coating liquid 4 is 0.0089 in mass ratio.

[Production of membrane sample 4]
A membrane sample 4 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 4.

[Example 5]
[Preparation of aqueous coating solution 5]
In the preparation of the aqueous coating solution 1, the aqueous coating solution was the same as the aqueous coating solution 1 except that the addition amount of aluminum metaphosphate as a binder precursor was changed from 0.300 parts by mass to 0.500 parts by mass. 5 was prepared. In addition, the content ratio of the binder precursor with respect to the silica particle in the aqueous coating liquid 5 is 0.0373 by mass ratio.

[Preparation of membrane sample 5]
A membrane sample 5 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 5.

[Example 6]
[Production of membrane sample 6]
The film was formed except that the film formed on the glass substrate was changed to a film thickness of 130 nm after drying and baking using the aqueous coating solution 1 used in the preparation of the film sample 1 and changed to a film thickness of 40 nm. In the same manner as Sample 1, a membrane sample 6 was produced.

[Example 7]
[Production of membrane sample 7]
Using the aqueous coating solution 1 used in the production of the film sample 1, the film formed on the glass substrate was changed from a film thickness of 130 nm after drying and baking to a film thickness of 360 nm. Similarly, a membrane sample 7 was produced.

[Example 8]
[Preparation of aqueous coating solution 8]
In the preparation of the aqueous coating solution 3, the aqueous coating solution was the same as the aqueous coating solution 3 except that the addition amount of aluminum metaphosphate as a binder precursor was changed from 0.300 parts by mass to 0.704 parts by mass. 8 was prepared. In addition, the content ratio of the binder precursor with respect to the silica particles in the aqueous coating liquid 8 is 0.0525 in mass ratio.

[Production of membrane sample 8]
A membrane sample 8 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 8.

[Example 9]
[Preparation of aqueous coating solution 9]
In the preparation of the aqueous coating solution 3, the aqueous coating solution was the same as the aqueous coating solution 3 except that the addition amount of aluminum metaphosphate as a binder precursor was changed from 0.300 parts by mass to 0.067 parts by mass. 8 was prepared. In addition, the content ratio of the binder precursor with respect to the silica particle in the aqueous coating liquid 8 is 0.0050 by mass ratio.

[Preparation of membrane sample 9]
A membrane sample 9 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 9.

[Example 10]
[Preparation of aqueous coating solution 10]
In the preparation of the aqueous coating solution 3, an aqueous dispersion of silica particles was prepared using a trade name: Snowtex (registered trademark) XL, an average primary particle diameter of silica particles: 50 nm, a solid content: 40% by mass, a surface potential: minus, Nissan. Made by Chemical Industry Co., Ltd., except that the addition amount was changed to 33.5 parts by mass, and the addition amount of aluminum metaphosphate as a binder precursor was changed from 0.300 parts by mass to 0.704 parts by mass. An aqueous coating solution 10 was prepared in the same manner as Solution 3. In addition, the content ratio of the binder precursor with respect to the silica particles in the aqueous coating liquid 10 is 0.0525 by mass ratio.

[Production of membrane sample 10]
A membrane sample 10 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 10.

[Example 11]
[Preparation of aqueous coating solution 11]
In the preparation of the aqueous coating liquid 3, an aqueous dispersion of silica particles was made from Snowtex (registered trademark) XL (trade name, average primary particle diameter of silica particles: 50 nm, solid content: 40 mass%, surface potential: minus, Nissan Chemical Co., Ltd. Manufactured by Kogyo Co., Ltd.), the addition amount was changed to 33.5 parts by mass, and the addition amount of aluminum metaphosphate as a binder precursor was changed from 0.300 parts by mass to 0.067 parts by mass. An aqueous coating solution 11 was prepared in the same manner as the coating solution 3. In addition, the content ratio of the binder precursor with respect to the silica particle in the aqueous coating liquid 11 is 0.0050 by mass ratio.
[Production of membrane sample 11]
A membrane sample 11 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 11.

[Example 12]
[Preparation of aqueous coating solution 12]
In the preparation of the aqueous coating liquid 1, an aqueous dispersion of silica particles was prepared by using a trade name: NALCO (registered trademark) 1130, nonporous silica particles, average primary particle diameter of silica particles: 8 nm, solid content: 30% by mass, surface Potential: minus, made by NALCO, the addition amount was changed to 44.70 parts by mass, and the addition amount of aluminum metaphosphate as a binder precursor was changed from 0.300 parts by mass to 0.134 parts by mass In the same manner as in the aqueous coating solution 1, an aqueous coating solution 12 was prepared. In addition, the content ratio of the binder precursor with respect to the silica particle in the aqueous coating liquid 12 is 0.0100 by mass ratio.
[Production of membrane sample 12]
A membrane sample 12 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 12.

[Example 13]
[Preparation of aqueous coating solution 13]
In the preparation of the aqueous coating liquid 1, an aqueous dispersion of silica particles was prepared by using a trade name: NALCO (registered trademark) 1130, nonporous silica particles, average primary particle diameter of silica particles: 8 nm, solid content: 30% by mass, surface Potential: minus, made by NALCO, the addition amount was changed to 44.70 parts by mass, and the addition amount of aluminum metaphosphate as a binder precursor was changed from 0.300 parts by mass to 0.469 parts by mass In the same manner as in the aqueous coating solution 1, an aqueous coating solution 13 was prepared. In addition, the content ratio of the binder precursor with respect to the silica particle in the aqueous coating liquid 13 is 0.0350 by mass ratio.
[Production of membrane sample 13]
A membrane sample 13 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 13.

[Example 14]
[Preparation of aqueous coating solution 14]
In the preparation of the aqueous coating liquid 1, an aqueous dispersion of silica particles was prepared using a trade name: Snowtex (registered trademark) AK, average primary particle diameter of silica particles: 10 nm, solid content: 18% by mass, surface potential: plus, Nissan An aqueous coating solution 14 was prepared in the same manner as the aqueous coating solution 1 except that the amount was changed to 74.4 parts by mass from Chemical Industries. In addition, the content ratio of the binder precursor with respect to the silica particle in the aqueous coating liquid 14 is 0.0224 in mass ratio.
[Production of membrane sample 14]
A membrane sample 14 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 14.

[Example 15]
[Preparation of aqueous coating solution 15]
An aqueous coating solution 15 was prepared in the same manner as the aqueous coating solution 1 except that no polyol type nonionic surfactant was added in the preparation of the aqueous coating solution 1. In addition, the content ratio of the binder precursor with respect to the silica particles in the aqueous coating liquid 15 is 0.0224 in mass ratio.
[Preparation of membrane sample 15]
A membrane sample 15 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 15.

[Example 16]
[Preparation of aqueous coating solution 16]
An aqueous coating solution 16 was prepared in the same manner as the aqueous coating solution 1 except that 0.1 mol / L hydrochloric acid was further added to adjust the pH to 8.0 in the preparation of the aqueous coating solution 1. In addition, the content ratio of the binder precursor with respect to the silica particles in the aqueous coating liquid 16 is 0.0224 in mass ratio.
[Production of membrane sample 16]
A membrane sample 16 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 16.

[Example 17]
[Preparation of aqueous coating solution 17]
In the preparation of the aqueous coating solution 1, an aqueous dispersion of silica particles was prepared using a trade name: Snowtex (registered trademark) O, an average primary particle diameter of silica particles: 10 nm, a solid content: 20% by mass, a surface potential: plus, Nissan. Aqueous coating solution 17 was prepared in the same manner as aqueous coating solution 1 except that the amount was 66.9 parts by mass and the polyol type nonionic surfactant was not added. In addition, the content ratio of the binder precursor with respect to the silica particle in the aqueous coating liquid 17 is 0.0224 in mass ratio.
[Preparation of membrane sample 17]
A membrane sample 17 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 17.

[Example 18]
[Production of membrane sample 18]
A membrane sample 19 was produced in the same manner as the membrane sample 1 except that the firing condition was changed to 150 ° C. in the production of the membrane sample 1.

[Example 19]
[Preparation of membrane sample 19]
A membrane sample 19 was produced in the same manner as the membrane sample 1 except that the firing condition was changed to 400 ° C. in the production of the membrane sample 1.

[Example 20]
[Production of membrane sample 20]
A membrane sample 20 was produced in the same manner as the membrane sample 1 except that the firing condition was changed to 500 ° C. in the production of the membrane sample 1.

[Example 21]
[Production of membrane sample 21]
A membrane sample 21 was produced in the same manner as the membrane sample 1 except that the firing condition was changed to 130 ° C. in the production of the membrane sample 1.

[Example 22]
[Membrane sample 22 production]
A membrane sample 22 was produced in the same manner as the membrane sample 1 except that the coating film drying step performed in the production of the membrane sample 1 and the optional coating film baking step were performed in one step.

[Example 23]
[Preparation of aqueous coating solution 23]
In the production of the aqueous coating liquid 1, an aqueous coating liquid 23 was prepared in the same manner as the aqueous coating liquid 1 except that the amount of the binder precursor added was changed to 0.80 parts by mass. In addition, the content ratio of the binder precursor with respect to the silica particles in the aqueous coating liquid 23 is 0.0600 in mass ratio.
[Production of membrane sample 23]
A membrane sample 23 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 23.

[Example 24]
[Preparation of aqueous coating solution 24]
In the production of the aqueous coating solution 1, the aqueous coating solution 24 was prepared in the same manner as the aqueous coating solution 1 except that the amount of addition of aluminum metaphosphate as a binder precursor was changed from 0.300 parts by mass to 0.05 parts by mass. Was prepared. In addition, the content ratio of the binder precursor with respect to the silica particles in the aqueous coating liquid 24 is 0.0040 in mass ratio.
[Preparation of membrane sample 24]
A membrane sample 24 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 25.

[Example 25]
[Preparation of aqueous coating solution 25]
In the preparation of the aqueous coating liquid 1, an aqueous dispersion of silica particles was prepared using a trade name: Snowtex (registered trademark) ST-30, an average primary particle diameter of silica particles: 10 nm, a solid content: 30% by mass, and a surface potential: minus. An aqueous coating solution 25 was prepared in the same manner as the aqueous coating solution 1 except that the amount was changed to 44.6 parts by mass from Nissan Chemical Industries. In addition, the content ratio of the binder precursor with respect to the silica particles in the aqueous coating liquid 25 is 0.0224 in mass ratio.
[Preparation of membrane sample 25]
A membrane sample 25 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the aqueous coating solution 25.

[Comparative Example 1]
[Preparation of comparative aqueous coating solution 1]
89.4 parts by mass of an aqueous dispersion of silica particles (trade name: NALCO (registered trademark) 8699, nonporous silica particles, average primary particle diameter of silica particles: 450 nm, solid content: 15% by mass, manufactured by NALCO) A comparative aqueous coating solution 1 was prepared by adding deionized water in an amount of 1000 parts by mass and stirring. In addition, the content ratio of the binder precursor with respect to the silica particle in the comparative aqueous coating liquid 1 is 0.0220 by mass ratio.
The pH of the comparative aqueous coating solution 1 (25 ° C.) was measured by the same method as that of the aqueous coating solution 1 and found to be 10.5.

[Production of Comparative Membrane Sample 1]
A comparative membrane sample 1 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the comparative aqueous coating solution 1.

[Comparative Example 2]
[Preparation of comparative aqueous coating solution 2]
In the production of the aqueous coating solution 1, a comparative aqueous coating solution 2 was prepared in the same manner as in the aqueous coating solution 1 except that the binder precursor aluminum metaphosphate was not added. The content ratio of the binder precursor to the silica particles in the comparative aqueous coating solution 2 is 0.000 in terms of mass ratio.

[Production of Comparative Membrane Sample 2]
A comparative membrane sample 2 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the comparative aqueous coating solution 2.

[Comparative Example 3]
[Preparation of comparative aqueous coating solution 3]
In the preparation of the aqueous coating solution 1, the product name: tetraethoxysilane (98% solution, molecular weight 208.3), solid content: 98% by mass, manufactured by Wako Pure Chemical Industries A comparative aqueous coating solution 3 was prepared in the same manner as the aqueous coating solution 1 except that the amount added was changed to 0.450 parts by mass. In addition, the content ratio of the binder precursor with respect to the silica particle in the comparative aqueous coating liquid 3 is 0.0329 by mass ratio.

[Production of Comparative Membrane Sample 3]
A comparative membrane sample 3 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the comparative aqueous coating solution 3.

[Comparative Example 4]
[Preparation of comparative aqueous coating solution 4]
In the preparation of the aqueous coating solution 1, instead of the binder precursor aluminum metaphosphate, the trade name: sodium sulfite (molecular weight: 126.0), solid content: 100% by mass, manufactured by Wako Pure Chemical Industries, Ltd. A comparative aqueous coating solution 4 was prepared in the same manner as the aqueous coating solution 1 except that was changed to 0.450 parts by mass. The content ratio of the binder precursor to the silica particles in the comparative aqueous coating solution 4 is 0.0347 in mass ratio.

[Preparation of Comparative Membrane Sample 4]
A comparative membrane sample 4 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the comparative aqueous coating solution 4.

[Comparative Example 5]
[Preparation of comparative aqueous coating solution 5]
In preparation of the aqueous coating solution 1, instead of aluminum metaphosphate as a binder precursor, sodium silicate (molecular weight 122.1), solid content: 38% by mass aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) was added. A comparative aqueous coating solution 5 was prepared in the same manner as the aqueous coating solution 1 except that the amount was changed to 0.750 parts by mass. The content ratio of the binder precursor to the silica particles in the comparative aqueous coating solution 5 is 0.0213 in terms of mass ratio.

[Production of Comparative Membrane Sample 5]
A comparative membrane sample 5 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the comparative aqueous coating solution 5.

[Comparative Example 6]
[Preparation of comparative aqueous coating solution 6]
In the preparation of the aqueous coating solution 1, a comparison was made in the same manner as in the aqueous coating solution 1, except that sodium hexametaphosphate (molecular weight 611.8, manufactured by Phosphor Chemical Industries) was used instead of aluminum metaphosphate as a binder precursor. An aqueous coating solution 6 was prepared. In addition, the content ratio of the binder precursor with respect to the silica particles in the comparative aqueous coating liquid 6 is 0.0224 in mass ratio.

[Preparation of Comparative Membrane Sample 6]
A comparative membrane sample 6 was produced in the same manner as the membrane sample 1 except that the aqueous coating solution 1 used in the production of the membrane sample 1 was changed to the comparative aqueous coating solution 6.

[Evaluation of aqueous coating solution]
The pH of each obtained aqueous coating solution at 25 ° C. was measured using a pH meter (model number: HM-31, manufactured by Toa DKK Co., Ltd.). The results are shown in Table 1 below.

[Evaluation of membrane sample]
About each film | membrane sample obtained above, the film thickness of the formed film | membrane, antireflection (AR: AntiReflection) property, scratch resistance, antifouling property, and surface shape were evaluated. The evaluation results are shown in Table 1.

<Film thickness>
About each film | membrane sample, film | membrane cutting was performed with the microtome, the field emission scanning electron microscope (FE-SEM) was observed from the cross-sectional direction, and the film thickness was measured. Each film sample was measured at 10 locations, and the average value was calculated to obtain the film thickness.

<Antireflection (AR)>
The reflectivity of each film sample with light having a wavelength of 400 nm to 1100 nm was measured using an integrating sphere with an ultraviolet-visible infrared spectrophotometer (model number: UV3100PC, manufactured by Shimadzu Corporation).
At the time of reflectance measurement, a black tape was attached to the glass substrate surface on the back surface in order to suppress reflection on the back surface of the glass substrate having the film sample (the surface on which the glass substrate film was not formed). . The average reflectance is calculated from the reflectance of each wavelength at wavelengths of 400 nm to 1100 nm obtained by measurement, and the absolute value (| ΔR |) of the change in average reflectance with respect to the glass substrate on which no film is formed is expressed by the following formula: Calculated according to (1). In addition, | ΔR | indicates that the higher the numerical value, the better the antireflection (AR) property.

| Average reflectance change ΔR | = | _{Average reflectance of base material after} R _{film formation−Average reflectance of} R _{base material} | Formula (1)

<Scratch resistance>
Using a rubbing tester under environmental conditions of a temperature of 25 ° C. and a relative humidity of 55%, the membrane surface of the membrane sample was subjected to a load of 50 g on steel wool (# 0000, manufactured by Nippon Steel Wool Co., Ltd.) at a speed of 1000 mm / min. After reciprocating 10 times in one direction, the film surface was observed visually and with an optical microscope (magnification: 100 times), and scratch resistance was evaluated according to the following evaluation criteria. Visual observation was performed under a fluorescent lamp and a tungsten light source. As for scratch resistance, [A], [B] and [C] are acceptable.

-Evaluation criteria-
[A]: No flaws were confirmed on the film surface by any of visual observation under a fluorescent lamp, visual observation under a tungsten light source, and observation with an optical microscope.
[B]: No damage was confirmed on the film surface by visual observation under a fluorescent lamp or visual observation under a tungsten light source, but slight damage was confirmed by observation with an optical microscope.
[C]: No flaws were confirmed on the film surface by visual observation under a fluorescent lamp, but slight flaws were confirmed on the film surface by visual observation under a tungsten light source and observation with an optical microscope.
[D]: In all of visual observation under a fluorescent lamp, visual observation under a tungsten light source, and observation with an optical microscope, linear scratches were confirmed on the film surface, and the number of scratches was 1 to 20. It was. The number of scratches parallel to the reciprocating direction of the rubbing tester was counted as one, regardless of the length of the scratch.
[E]: In all of visual observation under a fluorescent lamp, visual observation under a tungsten light source, and observation with an optical microscope, linear flaws were confirmed on the film surface, and the number of flaws was 21 or more.

<Anti-fouling>
A natural ocher pigment (manufactured by Holbein Co., Ltd.) was uniformly dispersed on the membrane of the membrane sample and adhered, and then the back surface of the membrane sample was struck to remove the attached natural ocher pigment. This operation was repeated 10 times. Thereafter, the adhesion state of the natural ocher pigment was visually confirmed, and the antifouling property was evaluated according to the following evaluation criteria. As for the antifouling property, [A] and [B] are acceptable.

-Evaluation criteria-
[A]: The natural ocher pigment did not adhere to the film surface, and the film surface was colorless and transparent.
[B]: Natural ocher pigment slightly adhered to the film surface, but the film surface was almost colorless and transparent.
[C]: A natural ocher pigment adhered to the entire surface of the film, and a decrease in transparency of the film surface was confirmed visually.
[D]: Natural ocher pigment adhered to the entire surface of the film surface, and the film surface was almost opaque.

<Surface shape>
The surface of the film sample after drying and before baking and the surface of the film sample after baking were observed visually and with an optical microscope (magnification: 100 times), and the surface condition was evaluated according to the following evaluation criteria. In Table 1, “after baking and before baking” is expressed as “unfired”, and “after baking” is expressed as “baking”. As for the planar shape, [A], [B] and [C] are allowable ranges.

-Evaluation criteria-
[A]: Aggregates of silica particles were not confirmed at all in an area of 30 cm square on the film surface by both visual observation and an optical microscope.
[B]: Aggregates of silica particles were not visually confirmed in an area of 30 cm square on the surface of the film, but a few aggregates of silica particles were confirmed by observation with an optical microscope.
[C]: Agglomerates of silica particles were confirmed in an area of less than 5% of an area of 30 cm square on the film surface.
[D]: Agglomerates of silica particles were confirmed in an area of 5% or more and less than 30% of the 30 cm square area on the film surface.
[E]: Agglomerates of silica particles were confirmed in a region of 30% or more of the area of 30 cm square on the film surface by visual observation.

As shown in Table 1, each film sample of the example formed using the aqueous coating liquid of the example was excellent in antireflection property, scratch resistance, and antifouling property.
From the comparison between Example 1 and Example 22, even when the coating film drying step and the coating film baking step are performed in one step, the resulting film is antireflective, as in the case where it is performed in two steps. It can be seen that both scratch resistance and antifouling properties are good.
On the other hand, even if the binder precursor was contained, Comparative Example 1 in which the particle diameter of the silica particles was large was inferior in all of antireflection properties, scratch resistance, and antifouling properties. Further, Comparative Example 2 using an aqueous coating solution not containing a binder precursor, and Comparative Examples 3 to 5 using a binder precursor containing a divalent or tetravalent element both have antifouling properties. It was defective and the desired scratch resistance was difficult to obtain. Even in the case of a salt of a compound containing a pentavalent element, Comparative Example 6 using an aqueous coating solution containing a compound having a molecular weight exceeding 600 was inferior in both antifouling properties and scratch resistance.

Claims (17)

Water, silica particles having an average primary particle size of 100 nm or less,
A binder precursor having a molecular weight of 600 or less, which is a salt of a compound containing at least one of a trivalent element and a pentavalent element that dissociates in a solution containing water;
An aqueous coating solution containing   The aqueous coating solution according to claim 1, wherein at least one of the trivalent element and the pentavalent element is at least one selected from aluminum, phosphorus, chromium, and iron.   The aqueous coating liquid according to claim 1 or 2, wherein a content ratio of the binder precursor to the silica particles is 0.0050 or more and 0.0525 or less by mass ratio.   4. The aqueous coating solution according to claim 1, wherein the silica particles have an average primary particle diameter of 1 nm to 50 nm.   The aqueous coating liquid according to any one of claims 1 to 4, wherein a content ratio of the binder precursor to the silica particles is 0.0100 or more and 0.0350 or less by mass ratio.   The aqueous coating solution according to claim 1, wherein the surface of the silica particles is negatively charged.   The aqueous coating solution according to any one of claims 1 to 6, wherein the pH is 8 or more and 12 or less. A coating film forming step of forming a coating film by applying the aqueous coating liquid according to any one of claims 1 to 7 on a substrate;
A coating film drying step of drying the formed coating film;
The manufacturing method of the film | membrane containing this.   The film manufacturing method according to claim 8, further comprising a coating film baking step of baking the dried coating film at a temperature of 150 ° C. or higher and 400 ° C. or lower after the coating film drying step.   Furthermore, the coating film baking process of baking the coating film after drying at the temperature of 150 degreeC or more and 400 degrees C or less is included, The said coating film drying process and the said coating film baking process are performed by 1 process. A method for producing a membrane. The coating film that has undergone at least the coating film drying step has an absolute value of the average reflectance change ΔR at the time of 5 ° incidence in the light having a wavelength of 400 nm to 1100 nm as defined by the following formula (1): 2.0% or more The manufacturing method of the film | membrane of any one of Claims 8-10.

| Average reflectance change ΔR | = | _{Average reflectance of base material after} R _{film formation−Average reflectance of} R _{base material} | Formula (1)
  The method for producing a film according to claim 11, wherein an absolute value of the average reflectance change ΔR is 2.5% or more.   Silica particles having an average primary particle diameter of 100 nm or less and at least one of trivalent elements and pentavalent elements, and the adjacent silica particles are at least of the trivalent elements and pentavalent elements The film | membrane which has the space | gap formed mutually fixed through 1 type.   The film according to claim 13, wherein the film thickness is 50 nm or more and 350 nm or less.   The laminated body which has a film | membrane of Claim 13 or Claim 14 on a base material.   The laminate according to claim 15, wherein the substrate is a glass substrate.   A solar cell module provided with the laminated body of Claim 15 or Claim 16.