JP2017114950A - Coating film and method for producing coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating film which can maintain excellent antireflection properties for the long term even under a high-temperature and high-humidity environment while achieving both high antireflection properties and high mechanical strength.SOLUTION: A coating film is predominantly composed of silica. The coating film has holes. The holes have an average value of major axes of 5-300 nm. Per a unit cross-sectional area of a cross section of the coating film, a ratio between the number (X) of holes with a major axis of less than 20 nm and the number (Y) of holes with a major axis of 20 nm or more, (Y/X), is 0.3-3.0.SELECTED DRAWING: None

Description

  The present invention relates to a coating film and a method for producing the coating film.

2. Description of the Related Art Conventionally, as a method for producing an antireflection film, a method of producing a coating film by a first step and a second step of forming pores in the coating film is known. After forming a coating film in this way, when pores are formed in the coating film, it is known that the antireflective film produced by the coating film has a reduced coating film refractive index and a reduced reflectance. Conventionally, various techniques relating to coating film formation have been proposed.
For example, Patent Documents 1 to 4 disclose a porous body in which pores are introduced into a coating film using a porous material.
Patent Documents 5 to 7 disclose a method for forming a low refractive index porous body that does not require extraction of a porous material from a coating film.
Further, Patent Documents 8 and 10 disclose an antireflection film having excellent scratch resistance obtained by using a coating liquid containing a chain silica sol and spherical fine particles.
Furthermore, in Patent Document 9, a coating using an aqueous polymer dispersion excellent in mechanical strength, transparency, weather resistance, chemical resistance, optical properties, antifouling properties, antifogging properties, antistatic properties and the like is used. A membrane is disclosed.
Furthermore, Patent Document 11 describes a coating composition having excellent antifouling performance.

Japanese Unexamined Patent Publication No. 01-31501 Japanese Patent Laid-Open No. 07-140303 Japanese Patent Laid-Open No. 03-199043 JP-A-11-035313 JP 2001-188104 A Japanese Patent Laid-Open No. 11-061043 JP 11-292568 A JP 2005-10470 A International Publication No. 2007/069596 Pamphlet Special table 2011-530401 gazette International Publication No. 2010/104146 Pamphlet

However, in the techniques disclosed in Patent Documents 1 to 4, the coating film swells when the porous material used for forming the pores is removed in the extraction process, resulting in poor appearance of the pores and film peeling. And the problem that the film forming process is complicated.
Moreover, the porous body obtained by the method currently disclosed by patent documents 5-7 has the problem that mechanical strength is scarce.
Furthermore, the antireflection films disclosed in Patent Documents 8 and 10 have a problem that there is room for improvement in weather resistance.
Furthermore, the coating films and coating compositions disclosed in Patent Documents 9 and 11 have a problem that there is room for improvement in antireflection properties.
Furthermore, it is known that an antireflective film based on a conventionally known glass is generally eluted from the inside of the glass in a humid environment. The component has a problem with respect to weather resistance such that it penetrates into the pores of the antireflection film and reduces the antireflection effect.

  Therefore, in the present invention, in view of the above-mentioned problems of the prior art, it has high antireflection characteristics, can maintain excellent antireflection characteristics even in a high temperature and high humidity environment, and also has excellent mechanical strength. It aims at providing a coating film.

As a result of intensive studies to solve the above problems, the inventors of the present invention have high antireflection characteristics and high mechanical strength by controlling the size of the pores in a specific state in the coating film having pores inside. Thus, the present inventors have found that a coating film that can maintain excellent antireflection properties for a long period of time even in a high temperature and high humidity environment has been obtained, and the present invention has been completed.
That is, the present invention is as follows.

[1]
A coating film mainly composed of silica,
Has holes,
The average value of the major axis of the holes is 5 to 300 nm,
The ratio (Y / X) of the number of holes having a major axis of less than 20 nm (X) to the number of holes having a major axis of 20 nm or more (Y) per unit cross-sectional area of the coating film is 0.3-3. 0.0, the coating film.
[2]
The ratio (Y / Z) of the number of holes having a major axis of less than 10 nm (Z) to the number of holes having a major axis of 20 nm or more (Y) per unit sectional area of the coating film is 1.0 to 10. The coating film according to [1], which is 0.0.
[3]
The coating film according to [1] or [2], wherein the volume ratio of the pores in the coating film is 20 to 60 vol%.
[4]
The coating film according to any one of [1] to [3], which is an antireflection film.
[5]
The method for producing a coating film according to any one of [1] to [4],
Applying and drying a coating composition comprising silica (A) and polymer emulsion particles (B); and
Sintering at a temperature of 500 ° C. or higher;
The manufacturing method of the coating film which has.
[6]
Glass for solar cells, comprising the coating film according to any one of [1] to [4].
[7]
The solar cell module containing the coating film as described in any one of said [1] thru | or [4].
[8]
The condensing lens for solar cells containing the coating film as described in any one of said [1] thru | or [4].

  According to the present invention, it is possible to obtain a coating film capable of maintaining excellent antireflection characteristics for a long period of time even in a high temperature and high humidity environment while achieving both high antireflection characteristics and high mechanical strength.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail.
The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified within the scope of the gist.
In the present specification, “(meth) acrylate” means both acrylate and the corresponding methacrylate. “(Meth) acrylic acid” means both acrylic acid and methacrylic acid corresponding thereto.

[Coating]
The coating film of this embodiment is
A coating film mainly composed of silica,
Has holes,
The average value of the major axis of the holes is 5 to 300 nm,
The ratio (Y / X) of the number of holes having a major axis of less than 20 nm (X) to the number of holes having a major axis of 20 nm or more (Y) per unit cross-sectional area of the coating film is 0.3-3. .0.
The “main component” means 70% by mass or more in the coating film, preferably 80% by mass or more, and more preferably 90% by mass or more.

(Vacancy)
The coating film of this embodiment has pores in the coating film.
The shape of the holes may be any of spherical, substantially spherical, elliptical, polyhedral, needle-like, plate-like, fiber-like, irregular shape, and the like. In particular, it is preferable that the pores have irregular shapes, even when the film thickness of the coating film is not uniform, the light transmission performance per area is less likely to be uneven.
The shape of the hole can be identified from a photograph of the hole directly observed with an electron microscope.

(Average value of major axis of holes)
The average value of the major axis of the pores of the coating film of this embodiment is 5 to 300 nm, preferably 5 to 150 nm, and more preferably 10 to 100 nm.
It is preferable that pores of various sizes exist in the range of the major axis (L) in the range of 5 ≦ L ≦ 300 nm, and further, the pores of various sizes in the range of the major axis (L) in the range of 5 ≦ L ≦ 150 nm. It is preferable that pores exist.
The average value of the major axis of the pores can be measured by the method described in the examples described later.
As a method for controlling the pore size within the above numerical range, the particle diameter of silica (A) and polymer emulsion particles (B), which are components of a coating composition used for forming a coating film described later, Examples include a method of controlling the addition amount of the decomposable silicon compound (C), adjusting the order of addition, stirring conditions at the time of preparing the coating composition, and adjusting means such as post-treatment adjustment.

The pores of the coating film of this embodiment have a specific size distribution.
Specifically, the ratio (Y / X) of the number of holes having a major axis of less than 20 nm (X) to the number of holes having a major axis of 20 nm or more (Y) per unit cross-sectional area of the coating film cross section is 0. 3 to 3.0. As a result, both high antireflection performance and high hardness can be achieved, and in particular, excellent performance is obtained in that the antireflection performance does not change significantly even after exposure to a high temperature and high humidity atmosphere. Preferably (Y / X) is 0.4 to 2.5, more preferably 0.5 to 2.0.
Furthermore, the ratio (Y / Z) of the number (Z) of holes having a major axis of less than 10 nm and the number of holes having a major axis of 20 nm or more (Y) is preferably 1.0 to 10.0, more preferably. Is 1.5 to 8.5, and more preferably 2.0 to 8.0.
The pore size distribution can be measured by the method described in Examples described later.

  Examples of a method for controlling the pore size distribution within the above numerical range include a method for controlling the composition of a polymer emulsion particle (B) described later used as a pore-forming material, and a degree of crosslinking of the polymer emulsion particle (B). And a method for controlling the sintering temperature and the heating rate.

(Volume ratio of holes)
It is preferable that the volume ratio of the void | hole which the coating film of this embodiment has is 20-60 vol% from a viewpoint of antireflection performance and hardness. More preferably, it is 35-60 vol%, More preferably, it is 40-55 vol%.
The volume ratio of pores in the coating film of this embodiment can be calculated from the refractive index of the coating film.
Specifically, using the refractive index of 1.46 of silica contained in the coating film of the present embodiment as the main component and the refractive index of air, that is, the refractive index of air 1, the following formula (1) is obtained from the refractive index of the coating film. Can be used to determine the volume ratio of the pores.
(Volume ratio of pores) = (1.46- (refractive index of coating film)) / (1.46-1) × 100 (1)
The refractive index of the coating film can be obtained, for example, by using a reflection spectral film thickness meter.
In order for the volume ratio of the pores to be in the above range, the average particle size and amount of silica described later, the average particle size and amount of the polymer emulsion particles are adjusted, or the addition order of each component at the time of preparing the coating composition And a method of adjusting the mixing conditions.

(Film thickness)
The coating film of this embodiment can be used as an antireflection film, and the film thickness of the coating film is preferably 50 nm or more and 150 nm or less, and preferably 80 nm or more and 130 nm or less from the viewpoint of sufficient antireflection performance. Is more preferable.
When the film thickness is 50 nm or more, the film strength tends to be sufficiently maintained, and when the film thickness is 150 nm or less, the antireflection performance becomes uniform and a uniform coating film tends to be obtained. .
In order to obtain a coating film having a film thickness in such a range, the coating speed may be adjusted.
The film thickness can be obtained by calculation by measuring a cross section with an electron microscope, or measuring reflected light due to interference of a thin film with an optical ellipsometer or a reflection spectral film thickness meter.

[Method for producing coating film]
The coating film of this embodiment is
Applying a coating composition comprising silica (A) and polymer emulsion particles (B) and drying;
Sintering at a temperature of 500 ° C. or higher;
Have.
That is, the coating film of this embodiment applies a coating composition containing silica (A) and polymer emulsion particles (B), and sinters the precursor formed by drying at a temperature of 500 ° C. or higher. It is formed by.

(Coating composition)
The coating film of this embodiment uses a coating composition containing silica (A) and polymer emulsion particles (B), so that heteroaggregation of silica (A) and polymer emulsion particles (B), or silica ( A) Aggregation between each other can be formed.
Moreover, as a result of the polymer emulsion particles (B) being removed by sintering, voids are formed.
It is preferable that the coating film of this embodiment further contains the hydrolyzable silicon compound (C) mentioned later in the said coating composition.

The coating composition which forms the coating film of this embodiment can be prepared by mixing silica (A) and polymer emulsion particles (B).
In addition, an acid as a hydrolysis catalyst or a condensation catalyst may be added to the coating composition. When these acids are added, silica (A) and polymer emulsion particles are added from the viewpoint of blending stability. After mixing (B) to obtain a mixture, it is preferable to add an acid to the mixture.
Further, after adding acid to silica (A) to the isoelectric point of silica (A) and agglomerating, neutralize and stabilize with a base, and then add polymer emulsion particles (B). A mixture may be obtained.

  Examples of the acid include, but are not limited to, hydrogen halides such as hydrochloric acid and hydrofluoric acid; carboxylic acids such as acetic acid, trichloroacetic acid, trifluoroacetic acid, and lactic acid; sulfuric acid, methanesulfonic acid, p -Sulfonic acids such as toluenesulfonic acid; acidic emulsifiers such as alkylbenzenesulfonic acid, alkylsulfonic acid, alkylsulfosuccinic acid, polyoxyethylene alkylsulfuric acid, polyoxyethylene alkylarylsulfuric acid, polyoxyethylene distyrylphenyl ether sulfonic acid; acidic Or, acidic compounds such as weakly acidic inorganic salts, phthalic acid, phosphoric acid and nitric acid can be mentioned.

The coating composition preferably contains 0.1% by mass to 15% by mass of solid content, more preferably 0.2% by mass to 5% by mass, and more preferably 0.5% by mass to 4% by mass. It is further preferable to include it.
By containing 15% by mass or less of the solid content, it tends to be easily controlled to a desired film thickness in the coating film after drying. By containing 0.1% by mass or more of the solid content, the desired dry film Since it is not necessary to apply the coating composition thickly to obtain the thickness, the film thickness tends to be easily controlled.

The viscosity of the coating composition is preferably 0.1 mPa · s or more and 2000 mPa · s or less at 20 ° C., more preferably 1 mPa · s or more and 100 mPa · s or less, and 2 mPa · s or more and 12 mPa · s or less. More preferably it is.
In order to control the viscosity of the coating composition within such a range, the amount of silica (A), the amount of polymer emulsion particles (B), the type of solvent used, The method of adjusting using a surface tension adjusting agent is mentioned.
The viscosity of the coating composition can be measured with a known viscometer.

As described above, the coating composition contains silica (A) and polymer emulsion particles (B), so that heteroaggregation of silica (A) and polymer emulsion particles (B), or silica (A). Aggregation between each other can be formed.
In addition, the coating composition is freed from the polymer emulsion particle (B) component to form pores (M) by a sintering process described later, and pores (N) are formed as pores between the silica (A) particles. ) Is formed. Thereby, a coating film having pores is obtained from the coating composition.

<Silica (A)>
The silica (A) preferably contains spherical silica (a1) and / or nonspherical silica (a2) having an aspect ratio (major axis / minor axis) of 3 to 25.
Here, the spherical silica (a1) refers to silica (A) that exists in a particle state with an aspect ratio (major axis / minor axis) of less than 3.
The aspect ratio refers to the aspect ratio of the primary particles for those present in the primary particles themselves, and the aspect ratio of the aggregated particles for those present as the aggregated particles.
The spherical silica (a1) may be primary particles or aggregated particles.
When the spherical silica (a1) is an agglomerated particle, the shape does not need to be a perfect sphere, and may have corners, for example.

Here, the aspect ratio of the spherical silica (a1) and the non-spherical silica (a2) is determined by measuring the minor axis and the major axis of the silica (A) taken with a transmission microscope (TEM), It can be calculated by determining the ratio of the major axis to the minor axis.
The minor axis and the major axis respectively correspond to the short side and the long side of the circumscribed rectangle that minimizes the area circumscribing the silica (A) particles.

In the coating composition which forms the coating film of this embodiment, it is preferable to contain the hydrolyzable silicon compound (C) mentioned later. By containing the hydrolyzable silicon compound (C), the hydrolyzable silicon compound (C) can be permeated into pores having a major axis of less than 20 nm, and the pore size can be controlled. it can.
In the coating composition, when the hydrolyzable silicon compound (C) described later is included, a hydrogen bond is formed between the silanol group of the hydrolyzable silicon compound (C) and the hydroxyl group present on the surface of the silica (A). Is formed. Thereby, the mechanical strength of the coating film obtained from the coating composition is further increased. The hydrolyzable silicon compound (C) will be described in detail below.

The number average particle diameter of the spherical silica (a1) is preferably 1 nm or more and 100 nm or less, and preferably 1 nm or more and 50 nm or less, from the viewpoint of the transparency and mechanical strength of the coating film of this embodiment. More preferably, it is 1 nm or more and 10 nm or less. Here, the number average particle size of the spherical silica (a1) is the primary particle size when the particles are present in the form of primary particles, and the aggregated particle size when the particles are present in the form of aggregated particles. It refers to (secondary particle diameter) and can be determined by the following method.
That is, the particle diameter of silica (a1) (2) present in a transmission microscope (TEM) photograph taken by adjusting spherical particles of silica (a1) so as to show 100 to 200 particles. The average axis diameter (that is, the average value of the minor axis and the major axis) is measured, and the average of these particle diameters is determined.
Specifically, the number average particle diameter of the spherical silica (a1) can be measured by the method described in Examples described later.

Specific examples of the non-spherical silica (a2) include composite particles in which primary particles of silica (a1) are connected in a bead shape, fibrous particles, acicular particles, plate-like particles, and hollow empty particles thereof. Can be mentioned.
As described above, the non-spherical silica (a2) has an aspect ratio (major axis / minor axis) of 3 or more and 25 or less, preferably 3 or more and 15 or less, and more preferably 3 or more and 10 or less.
The average major axis (average major axis) of the non-spherical silica (a2) is preferably 20 nm or more and 250 nm or less, more preferably 30 nm or more and 150 nm or less, and further preferably 40 nm or more and 100 nm or less. .
When the aspect ratio is 3 or more and the average major axis is 20 nm or more, suitable porosity and refractive index tend to be obtained. Moreover, it exists in the tendency which is excellent in transparency and anti-reflective performance because an aspect ratio is 25 or less and an average major axis is 250 nm or less. In order to obtain non-spherical silica (a2) having an aspect ratio and an average major axis in such ranges, it is effective to produce silica (A) by a known sol-gel method.
The number average particle diameter of the non-spherical silica (a2) can be measured by the same method as the method for measuring the average particle diameter of the silica (a1) described above. Specifically, the number average particle diameter of the non-spherical silica (a2) can be measured by the method described in Examples described later.
Further, the average major axis of the non-spherical silica (a2) is present in a transmission microscope (TEM) photograph taken by adjusting the non-spherical silica (a2) particles so that they are 100 to 200 particles. It is obtained by measuring the major axis of the silica (a2), and calculating the average of the measured major axes.

Specific examples of raw materials for forming the non-spherical silica (a2) include “Snowtex-OUP (registered trademark)” manufactured by Nissan Chemical Industries, Ltd., “Snowtex-UP (registered trademark)” manufactured by the same company, and manufactured by the same company. “Snowtex-PSSO (registered trademark)” and “Snowtex-PSS (registered trademark)” manufactured by the same company; alumina sol, pseudo boehmite-based alumina, and scaly silica “Sunlably” manufactured by Asahi Glass Co., Ltd. may be mentioned. This non-spherical silica (a2) may have a three-dimensionally curved shape.
From the viewpoint of improving the mechanical strength and antireflection effect of the coating film of this embodiment, the mixing ratio ((a1 / a2), mass ratio) of spherical silica (a1) to nonspherical silica (a2) is 1 /. It is preferably 40 or more and 1/1 or less, more preferably 1/20 or more and 1/3 or less, and further preferably 1/10 or more and 1/3 or less.

<Polymer emulsion particles (B)>
The coating composition which forms the coating film of this embodiment contains a polymer emulsion particle (B).
The polymer constituting the polymer emulsion particles (B) is not limited to the following. For example, polyurethane, polyester, poly (meth) acrylate, poly (meth) acrylate-silicone copolymer Copolymer, polyvinyl acetate, polybutadiene, polyvinyl chloride, chlorinated polypropylene, polyethylene, polystyrene, polystyrene- (meth) acrylate copolymer, rosin derivative, styrene-maleic anhydride copolymer alcohol A polymer composed of an adduct is exemplified.

From the viewpoint of coating film strength, the polymer emulsion particles (B) are composed of a hydrolyzable silicon compound (b1) and a vinyl compound (b2) having a secondary and / or tertiary amide group (hereinafter simply referred to as “vinyl compound ( b2) ") is preferably obtained by polymerization.
The polymer emulsion particles (B) are obtained by polymerizing a hydrolyzable silicon compound (b1) and a vinyl compound (b2) having a secondary and / or tertiary amide group in the presence of water and an emulsifier. More preferably, it is obtained.

  The polymer emulsion particles (B) are a copolymer obtained by polymerizing the hydrolyzable silicon compound (b1) and the vinyl compound (b2), and a single polymer obtained by polymerizing the hydrolyzable silicon compound (b1) and the vinyl compound (b2). Either a polymer mixture or a composite may be used, or a combination thereof may be used.

The number average particle diameter of the polymer emulsion particles (B) (primary particle diameter; the number average particle diameter of the primary particles of the polymer emulsion particles (B)) is preferably 3 nm to 800 nm, preferably 5 nm to 200 nm. More preferably, it is 10 nm or more and 150 nm or less, and further preferably 20 nm or more and 100 nm or less.
By adjusting the number average particle size of the polymer emulsion particles (B) to the above range, the coating film is further improved in weather resistance, chemical resistance, optical properties, antifouling properties, antifogging properties, antistatic properties, etc. Can be formed. Moreover, the number average particle diameter of the polymer emulsion particles (B) can be measured by the method described in Examples described later.

In the coating composition for forming the coating film of this embodiment, the polymer emulsion particles (B) can be cured by causing the silica (A) to interact with the polymer emulsion particles (B).
In this case, the coating film of this embodiment obtained from the coating composition is preferable because the mechanical strength is improved.

  Examples of the method for obtaining the polymer emulsion particles (B) having the number average particle diameter in the above-described range include a hydrolyzable silicon compound in the presence of a sufficient amount of water for the emulsifier to form micelles. Examples include a method of synthesizing the polymer emulsion particles (B) by so-called emulsion polymerization in which (b1) and the vinyl compound (b2) are polymerized.

  In the coating composition for forming the coating film of the present embodiment, from the viewpoint of the mechanical strength of the coating film, silica (A) is allowed to interact with the polymer emulsion particles (B), thereby polymer emulsion particles ( It is preferred to cure B).

  Specific examples of the interaction between silica (A) and polymer emulsion particles (B) described above include hydrogen bonding and chemical bonding. More specifically, the hydrogen bond between the hydroxyl group of silica (A) and the secondary and / or tertiary amide group of polymer emulsion particles (B), and the hydroxyl group of silica (A) and the polymer Examples thereof include condensation (chemical bond) with a polymerization product of a hydrolyzable metal compound constituting the emulsion particles (B).

Specific examples of the hydrolyzable silicon compound (b1) include a compound represented by the following formula (2), a condensation product thereof, and a silane coupling agent.
SiWxRy (2)
(In Formula (2), W is an alkoxy group having 1 to 20 carbon atoms, a hydroxyl group, an acetoxy group having 1 to 20 carbon atoms, a halogen atom, a hydrogen atom, an oxime group having 1 to 20 carbon atoms, an enoxy group, an aminoxy group, And at least one group selected from the group consisting of amide groups and R is a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, and a substituent. Or at least one hydrocarbon selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms substituted with a halogen atom X represents an integer of 1 or more and 4 or less, and y is an integer of 0 or more and 3 or less, and x + y = 4.

  The silane coupling agent is a hydrolyzable silicon compound in which a functional group having reactivity with an organic substance such as a vinyl polymerizable group, an epoxy group, an amino group, a methacryl group, a mercapto group, or an isocyanate group exists in the molecule. is there.

  Examples of the hydrolyzable silicon compound (b1) include, but are not limited to, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetraisoproxysilane, and tetra-n-butoxysilane; Methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, n-butyltrimethoxysilane N-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane, vinyltrimethoxysilane, vinyltriet Sisilane, allyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3,3,3-tri Fluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3- Droxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloxypropyltri Methoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloyloxypropyltriisopropoxysilane, 3- (meth) acryloyloxypropyltri-n-propoxysilane, 3 -Trialkoxysilanes such as (meth) acryloyloxypropyltriisopropoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxylane, di- n-propyldimethoxysilane, di-n-propyldiethoxysilane, diisopropyldimethoxysilane, diisopropyldiethoxysilane, di-n-butyldimethoxylane, di-n-pentyldimethoxysilane, di-n-pentyldiethoxysilane, di -N-hexyldimethoxysilane, di-n-hexyldiethoxysilane, di-n-heptyldimethoxysilane, di-n-heptyldiethoxysilane, di-n-octyldimethoxysilane, di-n-octyldiethoxy Dialkoxysilanes such as lan, di-n-cyclohexyldimethoxysilane, di-n-cyclohexyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane; trimethylmethoxysilane, And monoalkoxysilanes such as trimethylethoxysilane.

Among the hydrolyzable silicon compounds (b1), phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane and the like, which are silicon alkoxides having a phenyl group, are excellent in polymerization stability in the presence of water and an emulsifier. It is preferable because it is excellent.
Among the hydrolyzable silicon compounds (b1), 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyl Dimethoxysilane, 3- (meth) acryloyloxypropyltri-n-propoxysilane, 3- (meth) acryloyloxypropyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, 2-trimethoxysilyl Silane coupling agents having a vinyl polymerizable group such as ethyl vinyl ether, and silane coupling agents having a thiol group such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane are the above-mentioned secondary and / or Can form a chemical bond by copolymerization or chain transfer reaction with a vinyl compound (b2) having a tertiary amide group, and can form a coating film with further excellent weather resistance, chemical resistance, optical properties, strength, etc. Therefore, it is preferable.
As the hydrolyzable silicon compound (b1), in addition to the above-mentioned various compounds, a silane coupling agent having a vinyl polymerizable group or a thiol group, alone or the above-described silicon alkoxide, other silane coupling agents, and those Those mixed with or complexed with the condensation product can be used.
Moreover, these hydrolyzable silicon compounds (b1) may be used alone or in combination of two or more.

  The hydrolyzable silicon compound (b1) may be used as a condensation product. In such a case, the weight average molecular weight in terms of polystyrene by GPC (gel permeation chromatography) measurement of the condensation product is preferably 200 to 5000, More preferably, it is 300-1000.

  The blending amount of the hydrolyzable silicon compound (b1) as a raw material is a mass ratio ((b1) / (B) to the mass of the resulting polymer emulsion particles (B) (hereinafter also simply referred to as “(B)”). )) Is preferably in the range of 0.005 to 0.5. In addition, said (b1) represents the mass of a hydrolysable silicon compound (b1).

  The mass ratio of the component derived from the hydrolyzable silicon compound (b1), that is, the content in the polymer emulsion particles is based on the total amount of the polymer emulsion particles (B) (100% by mass) from the viewpoint of polymerization stability. 0.01 mass% or more and 50 mass% or less is preferable, and 0.1 mass% or more and 30 mass% or less is more preferable.

  The mass of the polymer emulsion particles (B) refers to the vinyl compound (b2), the other vinyl compound (b3) copolymerizable with the vinyl compound (b2) described later, and the hydrolyzable silicon compound (b1). ) And the mass of the polymerization product obtained by polymerization.

  As the hydrolyzable silicon compound (b1), it is more preferable to use a silane coupling agent having a vinyl polymerizable group from the viewpoint of the weather resistance of the coating film of this embodiment.

  The vinyl compound (b2) having a secondary and / or tertiary amide group is not limited to the following. For example, N-methylacrylamide, N-methylmethacrylamide, N-ethylacrylamide, N, N -Dimethylacrylamide, N, N-dimethylmethacrylamide, N, N-diethylacrylamide, N-ethylmethacrylamide, N-methyl-N-ethylacrylamide, N-methyl-N-ethylmethacrylamide, N-isopropylacrylamide, N -N-propylacrylamide, N-isopropylmethacrylamide, Nn-propylmethacrylamide, N-methyl-Nn-propylacrylamide, N-methyl-N-isopropylacrylamide, N-acryloylpyrrolidine, N-methacryloyl Loridine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylhexahydroazepine, N-acryloylmorpholine, N-methacryloylmorpholine, N-vinylpyrrolidone, N-vinylcaprolactam, N, N′-methylenebisacrylamide, N, N'-methylenebismethacrylamide, N-vinylacetamide, diacetone acrylamide, diacetone methacrylamide, N-methylol acrylamide, N-methylol methacrylamide and the like can be mentioned.

The amide group of the vinyl compound (b2) having a secondary and / or tertiary amide group is a secondary amide group and / or a tertiary amide group, but is a vinyl compound (b2) having a tertiary amide group. And the hydrogen bonding property between silica (A) in the resulting polymer emulsion particles (B) tends to increase.
Among the vinyl compounds (b2) having the tertiary amide, N, N-diethylacrylamide is excellent in polymerization stability in the presence of water and an emulsifier, and is a hydroxyl group of a polymerization product of the hydrolyzable silicon compound (b1). And a hydroxyl group of silica (A) tends to be able to form a strong hydrogen bond, which is more preferable.

  The polymerization product of the hydrolyzable silicon compound (b1) and the polymerization product of the vinyl compound (b2) having a secondary and / or tertiary amide group may be combined by hydrogen bonding and chemical bonding.

  The hydrolyzable silicon compound (b1) and the vinyl compound (b2) having a secondary and / or tertiary amide group are preferably complexed by various bonds such as a hydrogen bond and a chemical bond. There is no limitation on the form of coupling. Further, the above-described complexing may be performed only on a part of the polymer emulsion particles (B).

As polymer emulsion particles (B), a hydrolyzable silicon compound (b1) which is a silane coupling agent having a vinyl polymerizable group or a thiol group, and a vinyl compound (b2) having a secondary and / or tertiary amide group It is more preferable to use a polymer obtained by polymerizing, since a coating film having further excellent weather resistance, chemical resistance, optical properties, strength and the like can be formed.
The compounding amount of the hydrolyzable silicon compound (b1), which is a silane coupling agent having a vinyl polymerizable group or a thiol group, is a vinyl compound having a secondary and / or tertiary amide group from the viewpoint of polymerization stability ( b2) It is preferable that they are 0.1 mass part or more and 100 mass parts or less with respect to 100 mass parts, More preferably, they are 0.5 mass part or more and 50 mass parts or less, 0.5 mass part or more and 5 mass parts or less. More preferably, it is at most parts.

The vinyl compound (b2) having a secondary and / or tertiary amide group is a copolymer with another vinyl compound (b3) (hereinafter also simply referred to as “vinyl compound (b3)”) copolymerizable therewith. The copolymer may be contained in the polymer emulsion particles (B). Thereby, characteristics of the polymerization product to be generated (glass transition temperature, molecular weight, hydrogen bonding force, polarity, dispersion stability, weather resistance, compatibility with the polymerization product of the hydrolyzable silicon compound (b1), etc.) It tends to be possible to control more effectively, which is preferable.
Specifically, as the vinyl compound (b3), (meth) acrylic acid ester, aromatic vinyl compound, vinyl cyanide compound; carboxyl group-containing vinyl compound, hydroxyl group-containing vinyl compound, epoxy group-containing vinyl compound, carbonyl group-containing A compound containing a functional group such as a vinyl compound is exemplified. When a hydroxyl group-containing vinyl compound is used, it becomes easy to control the hydrogen bonding force between silica (A) and vinyl compound (b2), and the water dispersion stability of the polymer emulsion particles (B) can be improved. This is preferable because it tends to be possible.

The (meth) acrylic acid ester is not limited to the following, but, for example, a (meth) acrylic acid alkyl ester having 1 to 50 carbon atoms in the alkyl part and an ethylene oxide group having 1 to 100 ( Poly) oxyethylene di (meth) acrylate.
Examples of (meth) acrylic acid alkyl ester having 1 to 50 carbon atoms in the alkyl part include, but are not limited to, for example, methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylic. Examples include n-butyl acid, 2-ethylhexyl (meth) acrylate, methyl cyclohexyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, and dodecyl (meth) acrylate. Examples of the (poly) oxyethylene di (meth) acrylate having 1 to 100 ethylene oxide groups include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, diethylene glycol methoxy (meth) acrylate, di ( A meta) acrylic acid tetraethylene glycol is mentioned.
Examples of the aromatic vinyl compound include styrene and vinyl toluene.
Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile.

The amount of (meth) acrylic acid ester, aromatic vinyl compound, and vinyl cyanide compound (the total amount when multiple types are used) is the vinyl constituting the polymer emulsion particles (B). 0 mass% or more and 99.9 mass% or less are preferable with respect to the compound whole quantity ((b2) + (b3), 100 mass%), and 5 mass% or more and 80 mass% or less are more preferable.
The above (b2) represents the mass of the vinyl compound (b2), and the above (b3) represents the mass of the vinyl compound (b3).

Examples of the carboxyl group-containing vinyl compound include, but are not limited to, for example, (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, or itaconic acid, maleic acid. Examples include half esters of dibasic acids. By using these carboxylic acid group-containing vinyl compounds, an electrostatic repulsion force is provided between the polymer emulsion particles (B) due to the introduction of carboxyl groups into the polymer emulsion particles (B). And the stability as an emulsion tends to be improved. This makes it possible for the polymer emulsion particles (B) to have resistance to an external dispersion breaking action such as agglomeration during stirring. At this time, in order to further improve the electrostatic repulsion force, the introduced carboxyl group is partially or completely neutralized with ammonia and amines such as triethylamine and dimethylethanolamine; a base such as NaOH and KOH. Also good.
The blending amount of the carboxyl group-containing vinyl compound (when using a plurality of carboxyl group-containing vinyl compounds, the total amount thereof) is the total amount of all vinyl compounds constituting the polymer emulsion particles (B) from the viewpoint of water resistance ( (B2) + (b3), 100% by mass) is preferably 0% by mass to 50% by mass, more preferably 0.1% by mass to 10% by mass, More preferably, it is at least 5% by mass.

The hydroxyl group-containing vinyl compound as the vinyl compound (b3) is not limited to the following, but for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropi (meta) ) Hydroxyalkyl esters of (meth) acrylic acid such as acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate; di-2-hydroxyethyl fumarate, Hydroxyalkyl ester of fumaric acid such as mono-2-hydroxyethyl monobutyl fumarate; (poly) oxyethylene mono (meth) acrylate having 1 to 100 allyl alcohol or ethylene oxide groups; 1 propylene oxide group ~ 100 (Poly) oxypropylene mono (meth) acrylate; commercially available “Placcel FM, FA monomer” (trade name of caprolactone addition monomer, manufactured by Daicel Chemical Industries, Ltd.), other α, β-ethylenically unsaturated carboxylic acids Examples include hydroxyalkyl esters of acids.
When a hydroxyl vinyl compound is used as the vinyl compound (b3), it is easy to control the hydrogen bonding force between the silica (A) and the vinyl monomer (b2) having a secondary and / or tertiary amide group. In addition, the water dispersion stability of the polymer emulsion particles (B) can be improved.
The compounding amount of the hydroxyl group-containing vinyl compound is 0% by mass or more and 80% by mass or less with respect to the total amount of all vinyl compounds ((b2) + (b3), 100% by mass) constituting the polymer emulsion particles (B). It is preferably 0.1% by mass or more and 50% by mass or less, and more preferably 0.1% by mass or more and 10% by mass or less.

Examples of the epoxy group-containing vinyl compound include glycidyl group-containing vinyl compounds. Examples of the glycidyl group-containing vinyl compound include, but are not limited to, glycidyl (meth) acrylate, allyl glycidyl ether, and allyl dimethyl glycidyl ether.
Examples of the carbonyl-containing vinyl compound include, but are not limited to, diacetone acrylamide.
When an epoxy group-containing vinyl compound and / or a carbonyl group-containing vinyl compound is used, the polymer emulsion particles (B) become reactive and are resistant to solvents by crosslinking with hydrazine derivatives, carboxylic acid derivatives, isocyanate derivatives, and the like. It is possible to form a coating film having excellent properties.
The compounding amount of the epoxy group-containing vinyl compound and the carbonyl group-containing vinyl compound is 0% with respect to the total amount of all vinyl compounds constituting the polymer emulsion particles (B) ((b2) + (b3), 100% by mass). % To 50% by mass is preferable.

An emulsifier may be used in the synthesis of the polymer emulsion particles (B).
Examples of the emulsifier include, but are not limited to, alkylbenzenesulfonic acid, alkylsulfonic acid, alkylsulfosuccinic acid, polyoxyethylene alkylsulfuric acid, polyoxyethylenealkylarylsulfuric acid, polyoxyethylene distyrylphenyl ether sulfonic acid. Acidic emulsifiers such as alkali metal (Li, Na, K, etc.) salts of acidic emulsifiers, anionic surfactants such as ammonium salts of acidic emulsifiers, fatty acid soaps; alkyltrimethylammonium bromide, alkylpyridinium bromide, imidazolinium laurate Quaternary ammonium salts such as quaternary ammonium salts, pyridinium salts, imidazolinium salt type cationic surfactants; polyoxyethylene alkylaryl ethers, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene Oxypropylene block copolymer, nonionic surface active agent polyoxyethylene distyryl phenyl ether, and a reactive emulsifier having a radical-polymerizable double bond.
Among these emulsifiers, the reactive emulsifier having a radical polymerizable double bond further improves the water dispersion stability of the polymer emulsion particles (B), and also has water resistance, chemical resistance, and optical properties. It is preferable because it tends to form a coating film excellent in strength and the like.

  The reactive emulsifier having a radically polymerizable double bond is not limited to the following. For example, a vinyl compound having a sulfonic acid group or a sulfonate group, a vinyl compound having a sulfate group, or an alkali metal thereof. A vinyl compound having a nonionic group such as polyoxyethylene; a vinyl compound having a quaternary ammonium salt.

Examples of the salt of the vinyl compound having a sulfonic acid group or a sulfonate group include, but are not limited to, for example, an ammonium salt, a sodium salt, or potassium having a radical polymerizable double bond and a sulfonic acid group. Alkyl group having 1 to 20 carbon atoms, alkyl ether group having 2 to 4 carbon atoms, polyalkyl ether group having 2 to 4 carbon atoms, aryl group having 6 or 10 carbon atoms, partially substituted with a group that is a salt And a compound having a substituent selected from the group consisting of a succinic acid group; and a vinyl sulfonate compound having a vinyl group to which a group which is an ammonium salt, sodium salt or potassium salt of a sulfonic acid group is bonded.
Examples of the compound having a succinic acid group partially substituted with a group that is an ammonium salt, a sodium salt or a potassium salt of a sulfonic acid group include allylsulfosuccinate.
Moreover, as a commercial item, Eleminol JS-2 (trade name) (manufactured by Sanyo Kasei Co., Ltd.), Latemul S-120, S-180A or S-180 (trade name) (manufactured by Kao Corp.) can be mentioned. .
As a compound having an alkyl ether group having 2 to 4 carbon atoms or a polyalkyl ether group having 2 to 4 carbon atoms, partially substituted by a group which is an ammonium salt, sodium salt or potassium salt of a sulfonic acid group, Aqualon HS-10 or KH-1025 (trade name) (Daiichi Kogyo Seiyaku Co., Ltd.), Adeka Soap SE-1025N or SR-1025 (trade name) (Asahi Denka Kogyo Co., Ltd.) can be mentioned.

  Examples of the vinyl compound having a nonionic group include, but are not limited to, α- [1-[(allyloxy) methyl] -2- (nonylphenoxy) ethyl] -ω-hydroxypolyoxyethylene (product) Name: Adekaria soap NE-20, NE-30, NE-40, etc., manufactured by Asahi Denka Kogyo Co., Ltd., polyoxyethylene alkylpropenyl phenyl ether (trade names: Aqualon RN-10, RN-20, RN-30 , RN-50, etc., manufactured by Daiichi Pharmaceutical Industry Co., Ltd.).

  The amount of the emulsifier is preferably 10 parts by mass or less, and more preferably 0.001 part by mass or more and 5 parts by mass or less with respect to the total amount (100 parts by mass) of the polymer emulsion particles (B).

The polymer emulsion particles (B) are obtained by carrying out the polymerization of the hydrolyzable silicon compound (b1) and the vinyl compound (b2) having a secondary and / or tertiary amide group in the presence of a polymerization catalyst. Is preferred.
The polymerization catalyst for the hydrolyzable silicon compound (b1) is not particularly limited because it can be appropriately selected depending on the components used for the polymerization. Carboxylic acids such as chloroacetic acid, trifluoroacetic acid, trifluoroacetic acid and lactic acid; sulfonic acids such as sulfuric acid and p-toluenesulfonic acid; alkylbenzenesulfonic acid, alkylsulfonic acid, alkylsulfosuccinic acid, polyoxyethylene alkylsulfuric acid, polyoxyethylene alkylarylsulfuric acid Acidic emulsifiers such as polyoxyethylene distyryl phenyl ether sulfonic acid; acidic or weakly acidic inorganic salts, acidic compounds such as phthalic acid, phosphoric acid, nitric acid; sodium hydroxide, potassium hydroxide, sodium methylate, Sodium acetate, tetramethylammonium chloride, Basic such as lamethylammonium hydroxide, tributylamine, diazabicycloundecene, ethylenediamine, diethylenetriamine, ethanolamines, γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) -aminopropyltrimethoxysilane Compounds: Examples include tin compounds such as dibutyltin octylate and dibutyltin dilaurate.
Among these, acidic emulsifiers are preferable from the viewpoint of having an effect as an emulsifier as well as a polymerization catalyst, and alkylbenzenesulfonic acid having 5 to 30 carbon atoms is more preferable.

The polymerization catalyst for the vinyl compound (b2) having a secondary and / or tertiary amide group is preferably a radical polymerization catalyst that undergoes radical decomposition by heat or a reducing substance to cause addition polymerization of the vinyl compound.
The polymerization catalyst for the vinyl compound (b2) is not limited to the following, and examples thereof include water-soluble or oil-soluble persulfates, peroxides, and azobis compounds.
More specifically, potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, 2,2-azobisisobutyronitrile, 2,2- Examples thereof include azobis (2-diaminopropane) hydrochloride and 2,2-azobis (2,4-dimethylvaleronitrile).

  When acceleration of the polymerization rate or lower temperature polymerization at 70 ° C. or lower is desired, it is preferable to use a reducing agent such as sodium bisulfite, ferrous chloride, ascorbate, Rongalite in combination with the radical polymerization catalyst.

As a compounding quantity of the said polymerization catalyst, it is preferable that it is 0.001 mass part or more and 5 mass parts or less with respect to 100 mass parts of all the vinyl compounds which comprise a polymer emulsion particle (B).
As described above, the polymer emulsion particles (B) are hydrolyzed silicon compound (b1) in the presence of water and an emulsifier, vinyl compound (b2) having secondary and / or tertiary amide groups, and further if necessary. Accordingly, it can be obtained by polymerization using another vinyl compound (b3) copolymerizable with the vinyl compound (b2), preferably under a polymerization catalyst.

  Polymerization of the hydrolyzable silicon compound (b1) and the vinyl compound (b2) having a secondary and / or tertiary amide group can be carried out separately. It is preferable because micro organic and inorganic composites can be achieved by hydrogen bonding or the like.

The number average particle size of the polymer emulsion particles (B) (primary particle size: the number average particle size of the primary particles of the polymer emulsion particles (B)) is preferably 3 to 800 nm. By adjusting the number average particle size of the polymer emulsion particles (B) to the above range, the coating film is further improved in weather resistance, chemical resistance, optical properties, antifouling properties, antifogging properties, antistatic properties, etc. Can be formed.
Further, from the viewpoint of improving the transparency of the obtained coating film, the thickness is more preferably 5 nm or more and 200 nm or less, further preferably 10 nm or more and 150 nm or less, and further preferably 20 nm or more and 100 nm or less.
The method for obtaining the polymer emulsion particles (B) having such a number average particle diameter is not particularly limited, but the hydrolyzable silicon compound (in the presence of a sufficient amount of water for the emulsifier to form micelles) A method of synthesizing the polymer emulsion particles (B) by so-called emulsion polymerization, in which the vinyl compound (b2) having b1) and secondary and / or tertiary amide groups is polymerized.
As the emulsion polymerization method of the polymer emulsion particles (B), a hydrolyzable silicon compound (b1), a vinyl compound (b2) having a secondary and / or tertiary amide group, and a vinyl compound (if necessary) b3) as it is or in an emulsified state, after being dropped into the reaction vessel all at once, divided or continuously, and then in the presence of the polymerization catalyst, preferably under atmospheric pressure to 10 MPa as necessary, and The method of superposing | polymerizing on the conditions of about 30 degreeC or more and 150 degrees C or less reaction temperature is mentioned. In addition, you may change these pressures and reaction temperature suitably.

  The total amount of the hydrolyzable silicon compound (b1) and the total vinyl compound ((b2 + b3)) is not particularly limited, but the final solid content (all compounds are based on the total amount of these and water (100% by mass)). As a polymer obtained by polymerization (value calculated based on the total mass (calculated value) of vinyl (co) compound (b2, b3) and hydrolyzable silicon compound (b1) polymerization product)) 0.1 mass% or more and 70 mass% or less is preferable, and 1 mass% or more and 55 mass% or less is more preferable.

  In the emulsion polymerization of the polymer emulsion particles (B), a seed polymerization method in which the emulsion particles are previously present in the aqueous phase in order to grow or control the number average particle diameter of the polymer emulsion particles (B). The polymerization may be carried out at Thereby, it exists in the tendency which can obtain the polymer emulsion particle (B) with a more uniform number average particle diameter. The substance serving as the seed (nucleus) can be appropriately selected according to the reaction conditions and the like.

  The pH in the system in the polymerization reaction is preferably 1.0 or more and 10.0 or less, and more preferably 1.0 or more and 6.0 or less. In order to control the pH within such a range, it is possible to adjust using a pH buffer such as disodium phosphate, borax, sodium bicarbonate, and ammonia.

  As a method for obtaining the polymer emulsion particles (B), after polymerizing the hydrolyzable silicon compound (b1) and the vinyl compound (b2) in the presence of water, an emulsifier necessary for polymerization, and a solvent as necessary. Alternatively, a method of adding water until the polymerization product becomes an emulsion may be employed.

The polymer emulsion particles (B) preferably have a core layer and a shell layer.
The shell layer refers to the outermost layer, and layers other than the shell layer are core layers.
Furthermore, the flexibility of the core layer and the flexibility of the shell layer are preferably different, and the flexibility of the shell layer is more preferably higher than the flexibility of the core layer. When the flexibility of the shell layer is higher than the flexibility of the core layer, a desired coating film tends to be produced efficiently.
In order to control the flexibility of the core layer and the shell layer, as the hydrolyzable silicon compound (b1), a hydrolyzable silicon compound (b1-3) containing 3 or more hydrolyzable functional groups (hereinafter simply referred to as “ Hydrolyzable silicon compound (b1-3) "), and the vinyl monomer (b2) having the secondary and / or tertiary amide groups of the hydrolyzable silicon compound (b1-3) and the whole. It is preferable to prescribe | regulate the mass ratio with respect to the total amount of a hydrolysable silicon compound (b1).

The polymer emulsion particle (B) includes a core layer and a shell layer, a component derived from the hydrolyzable silicon compound (b1), and a vinyl compound (b2) having a secondary amide group and / or a tertiary amide group. It is preferable to contain the component derived from.
Moreover, it is preferable that the said hydrolysable silicon compound (b1) contains the hydrolysable silicon compound (b1-3) containing 3 or more hydrolyzable functional groups.

In the polymer emulsion particles (B), the mass ratio of the component derived from the hydrolyzable silicon compound (b1-3) contained in the core layer preferably satisfies the following formula (3).
Furthermore, it is more preferable to satisfy the following formula (3) in which “0.20” in the following formula (3) is set to “0.35”.
By satisfying the following formula (3), the coating film strength tends to be improved.
((B11-3) / ((b11) + (b12))) ≧ 0.20 (3)
(In Formula (3), (b11-3) represents the mass of the component derived from the hydrolyzable silicon compound (b1-3) contained in the core layer, and (b11) represents the total amount contained in the core layer. The mass of the component derived from the hydrolyzable silicon compound (b1) is represented, and (b12) represents the mass of the component derived from the vinyl compound (b2) contained in the core layer.

In the polymer emulsion particles (B), the mass ratio of the component derived from the hydrolyzable silicon compound (b1-3) in the shell layer preferably satisfies the following formula (4).
((B21-3) / ((b21) + (b22))) ≦ ((b11-3) / ((b11) + (b12))) (4)
(In Formula (4), (b21-3) represents the mass of the component derived from the hydrolyzable silicon compound (b1-3) contained in the shell layer, and (b21) represents the total amount contained in the shell layer. The mass of the component derived from the hydrolyzable silicon compound (b1) is represented, (b22) represents the mass of the component derived from the vinyl compound (b2) contained in the shell layer, and (b11-3) represents the core layer. Represents the mass of the component derived from the hydrolyzable silicon compound (b1-3) contained in (b1-3), (b11) represents the mass of the component derived from the total hydrolyzable silicon compound (b1) contained in the core layer, (B12) represents the mass of the component derived from the vinyl compound (b2) contained in the core layer.)

The coating film of this embodiment is obtained by applying a coating composition containing silica (A) and polymer emulsion particles (B), and if necessary, drying and sintering.
That is, in the coating film, all or part of the polymer emulsion particles (B) are removed by the sintering, and pores (M) are formed.
At that time, the condensation of the silica (A) layer around the polymer emulsion particles (B) proceeds rapidly, and the entire coating film shrinks. Here, since the core layer and the shell layer having different flexibility of the polymer emulsion particles (B) are present, the contraction of the coating film is alleviated, and the coating film is formed while suppressing the collapse of the pores (M). be able to.
As a result, it is possible to efficiently form a dense hole (N) around the hole (M) while retaining the hole (M), and to exhibit high antireflection performance and strength. Become. The term “periphery” means that the surface is in direct contact with the surface of the pore (M) or exists at a distance that allows chemical interaction. Moreover, it is suppressed that the base-material interface which forms a coating film, and the void | hole (M) in a coating film contact | connect directly. This is presumably because the polymer emulsion particles (B) relieve shrinkage of the coating film, thereby suppressing the pores (M) from being crushed and coming into contact with the substrate.

As described above, the hydrolyzable silicon compound (b1) preferably contains a hydrolyzable silicon compound (b1-3) containing three or more hydrolyzable functional groups.
Examples of the hydrolyzable silicon compound (b1-3) include, but are not limited to, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, and tetra-n-butoxy. Tetraalkoxysilanes such as silane; methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxy Silane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane, vinyl Rimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxy Propyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3 -Glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropyltri-n-propoxysilane, 3- (meth) acryloyloxypropyltriisopropoxysilane, 3-ure And trialkoxysilanes such as idpropyltrimethoxysilane and 3-ureidopropyltriethoxysilane.

  The polymer emulsion particles (B) are usually added to and blended with paints and molding resins, for example, thickeners, leveling agents, thixotropic agents, antifoaming agents, depending on the application and usage method. , Freezing stabilizer, Matting agent, Crosslinking reaction catalyst, Pigment, Curing catalyst, Crosslinking agent, Filler, Anti-skinning agent, Dispersant, Wetting agent, Light stabilizer, Antioxidant, UV absorber, Rheology control agent Antifoaming agent, film forming aid, rust preventive agent, dye, plasticizer, lubricant, reducing agent, antiseptic agent, antifungal agent, deodorant agent, yellowing preventive agent, antistatic agent or charge control agent Can be blended.

<Hydrolyzable silicon compound (C)>
In addition to the silica (A) and polymer emulsion particles (B) described above, the coating film of this embodiment is distinguished from the hydrolyzable silicon compound used for the polymerization of the polymer emulsion particles (B). It is preferable to further contain a silicon compound (C).
When the hydrolyzable silicon compound (C) is contained, a bond is formed by a condensation reaction between the silanol group of the hydrolyzable silicon compound (C) and the hydroxyl group present on the surface of the silica (A), or A hydrogen bond is formed between the hydrolyzable silicon compound (C) and the silica (A). By these, the coating film obtained from the said coating composition exists in the tendency for mechanical strength to increase more.
The coating film of this embodiment has an antifouling effect against hydrophilic dirt when it has surface hydrophilicity due to silica (A) and hydrolyzable silicon compound (C). That is, it has an antifouling effect in which dirt is washed away by rainwater.

The hydrolyzable silicon compound (C) is preferably one or more hydrolyzable silicon compounds selected from the group consisting of compounds represented by the following formulas (5), (6), and (7).
The hydrolyzable silicon compound (b1) described above is a component that constitutes the polymer emulsion particles (B), and is integrally incorporated in the polymer emulsion particle (B) component. Therefore, the hydrolyzable silicon compound (C) added independently from the polymer emulsion particles (B) is clearly distinguished from the hydrolyzable silicon compound (b1).

R ¹ _n SiX _4-n (5)
(In Formula (5), R ¹ may have any one selected from the group consisting of a hydrogen atom, a halogen group, a hydroxy group, a mercapto group, an amino group, a (meth) acryloyl group, and an epoxy group, Represents an alkyl group, an alkenyl group, an alkynyl group or an aryl group of formulas 1 to 10. X represents a hydrolyzable group, and n is an integer of 0 to 3.

X ³ Si—R ² _n —SiX ³ (6)
(In the formula (6), X ³ represents a hydrolyzable group, R ² represents .n representing an alkylene group or a phenylene group having 1 to 6 carbon atoms is 0 or 1.)

R ³ — (O—Si (OR ³ ) ₂ ) _n —OR ³ (7)
(In the formula (7), R ³ is .n represents an alkyl group having 1 to 6 carbon atoms is an integer of 2-8.)

The coating composition of the present embodiment comprises a mass of silica (A) (hereinafter also simply referred to as “(A)”) and a mass of polymer emulsion particles (B) (hereinafter also simply referred to as (B)). The mass ratio ((A) :( B)) is preferably 1: 0.05 to 1:10, more preferably 1: 0.1 to 1: 5, and 1: 0.5 to More preferably, it is 1: 3.
From the viewpoint of strength, the mass ratio ((A) :( C)) between the mass of silica (A) and the hydrolyzable silicon compound (C) (hereinafter also simply referred to as “(C)”) is 1: It is preferably 0.05 to 1: 5, more preferably 1: 0.1 to 1: 3, and even more preferably 1: 0.5 to 1: 2.

The mass ratio of silica (A) to polymer emulsion particles (B) ((A) :( B)) is (A) :( B) = 1: 0 from the viewpoint of weather resistance when used as a coating film. .05 or more, and preferably 1:10 or less from the viewpoint of transparency.
The mass ratio ((A) :( C)) of silica (A) and hydrolyzable silicon compound (C) is preferably 1: 0.05 or more from the viewpoint of mechanical strength and weather resistance. Further, ((A) :( C)) is preferably 1: 5 or less from the viewpoint of increasing the porosity and making the coating film have a low refractive index. The mass of the hydrolyzable silicon compound (C) is the mass in terms of SiO ₂ after hydrolysis and condensation of the hydrolyzable silicon compound (C).

It is preferable that the coating film of this embodiment contains the hydrolysis condensate (C ′) of the hydrolyzable silicon compound (C) described above (hereinafter simply referred to as “hydrolysis condensate (C ′)”).
Further, the coating film is composed of the hydrolysis condensate (C ′), polymer particles (B ′) produced by sintering the polymer emulsion particles (B) in the coating film (hereinafter simply referred to as “polymer particles ( B ′) ”)), and the non-spherical silica (a2) is bonded to the surface of the polymer particles (B ′) directly or via the spherical silica (a1), and the pores (M) It is preferable to have a structure that can be formed.
Further, the structure in which the non-spherical silica (a2) is bonded directly to the surface of the polymer particle (B ′) or indirectly through the spherical silica (a1) is a hydrolysis condensate (C ′). More preferably, the pores (M) are formed through the coating composition coated on the polymer particles (B ′). The coating film having such a structure tends to exhibit excellent mechanical strength and weather resistance as an antireflection film.

  The coating film of this embodiment consists of a coating film formed on a predetermined substrate, and is formed by applying a coating composition containing silica (A) and polymer emulsion particles (B) and drying it. It is preferable that the precursor is formed by sintering at a temperature of 500 ° C. or higher.

(Base material)
The coating film of this embodiment is formed on a predetermined substrate.
Various substrates can be selected depending on the application of the coating film of the present embodiment. As the substrate, although not limited to the following, for example, organic substrates such as synthetic resins and natural resins, inorganic substrates such as glass, and combinations thereof can be applied, specifically, Solar cell components (glass, modules, etc.), solar cell condensing lenses, photocells, liquid crystal displays, glasses, window glass, TV towers, various types of light transmission enhancement and / or prevention of reflection Member.
Other protective materials for solar power generation, concentrating solar power generation mirrors, solar power generation mirrors, condensing glass for solar power generation, buildings, steel structures, building materials, mortar, concrete, plastic, automobiles, etc. As mentioned.

(Coating process)
In the coating composition application step in the coating film manufacturing method of this embodiment, a coating composition containing silica (A) and polymer emulsion particles (B) is applied to a predetermined substrate.
The method for applying the coating composition to the substrate is not limited to the following, but includes, for example, spraying, flow coating, roll coating, brush coating, dip coating, spin coating, and screen printing. Method, casting method, gravure printing method, flexographic printing method and the like.
From the viewpoint of productivity, a roll coating method, a screen printing method, and a gravure printing method are preferable. For the purpose of coating on a large-sized substrate, a roll coating method is preferred.

(Drying process)
In the drying process in the coating film manufacturing method of the present embodiment, the coating composition is dried. In other words, after the coating composition is applied onto the substrate as described above, the coating composition is dried to remove the solvent that can be contained in the coating composition.
The drying method is not limited to the following, and examples thereof include natural drying, cold air drying, hot air drying, and infrared drying.
The drying temperature is preferably 5 ° C. or higher and 700 ° C. or lower, more preferably 10 ° C. or higher and 300 ° C. or lower, further preferably 20 ° C. or higher and 200 ° C. or lower, and even more preferably 25 ° C. or higher and 80 ° C. or lower.

(Sintering process)
In the sintering step in the coating film manufacturing method of the present embodiment, the coating composition is sintered at a temperature of 500 ° C. or higher. That is, the applied coating composition is sintered at a temperature of 500 ° C. or higher as a pore forming step. The sintering temperature is preferably 500 ° C. or higher and 800 ° C. or lower, and more preferably 600 ° C. or higher and 700 ° C. or lower. Further, sintering may be performed by performing ultraviolet irradiation such as a high-pressure mercury lamp simultaneously or in series.

  The coating film of this embodiment is a coating film formed on a substrate from the viewpoint of weather resistance, and silica (A) and / or hydrolysis condensate (C ′) is directly bonded to the substrate. It is preferable that

The surface water contact angle of the coating film of this embodiment is preferably 120 ° or less, more preferably 40 ° or less, and even more preferably 20 ° or less from the viewpoint of antifouling properties.
When the surface water contact angle is 40 ° or less, it tends to have an effect of preventing hydrophilic dirt, and when it is 40 ° or more, lipophilic dirt tends to be easily wiped off.

[Use]
Since the coating film of this embodiment is excellent in transparency, antireflection characteristics, and durability, it can be used as a coating film for solar cells.
That is, it can be applied as a coating film for glass for solar cells, a coating film for solar cell modules, and a coating film for condensing lenses for solar cells.
By setting it as these coating films, the improvement of the output of a solar cell is achieved and the solar cell which can maintain a high output over a long term is obtained.

Hereinafter, the present embodiment will be described more specifically with specific examples and comparative examples. However, the present embodiment is not limited to the following examples.
Measurement and evaluation of various physical properties in Synthesis Examples, Examples, and Comparative Examples described later were measured and evaluated by the following methods.

[Measurement of physical properties]
((Physical property 1) Number average particle diameter of silica (A) (nm))
About the silica (A) used in the examples and comparative examples described later, the transmission type is adjusted by magnifying the particles to 50,000 to 100,000 times and reflecting 100 to 200 spherical silica (A) particles. Pictures were taken using a microscope.
Next, the particle diameter (major axis and minor axis) of each photographed silica (A) was measured, and the average value ((major axis + minor axis) / 2) was determined. The average value for 100 to 200 silica (A) particles was calculated and used as the number average particle size.

((Physical property 2) Number average particle diameter (nm) of polymer emulsion particles (B))
The number average particle diameter of the polymer emulsion particles (B) produced by the synthesis example described later was measured with a dynamic light scattering type particle size distribution measuring device (trade name: Microtrac UPA, manufactured by Nikkiso Co., Ltd.).

((Property 3) Mass ratio of components derived from hydrolyzable silicon compound (b1-3) containing three or more hydrolyzable functional groups in the core layer and shell layer of polymer emulsion particles (B))
Vinyl compound (b2) of the mass (b11-3) of the component derived from the hydrolyzable silicon compound (b1-3) containing three or more hydrolyzable functional groups in the core layer of the polymer emulsion particles (B) The ratio of the mass of the component derived from (b12) and the mass of the component derived from the total hydrolyzable silicon compound (b1) to the total amount (b11), that is, ((b11-3) / ((b11) + (b12 )) Was calculated and is shown in “Mass ratio core layer” in Tables 1 and 2.
Moreover, the mass of the component derived from the vinyl compound (b2) of the mass (b21-3) of the component derived from the hydrolyzable silicon compound (b1-3) containing three or more hydrolyzable functional groups in the shell layer. The ratio to the total amount of (b22) and the mass (b21) of the component derived from the total hydrolyzable silicon compound (b1), that is, ((b21-3) / ((b21) + (b22)) was calculated. This is shown as “mass ratio shell layer” in Tables 1 and 2.

((Physical property 4) Pore size distribution (number (X) whose major axis is less than 20 nm, number (Y) whose major axis is 20 nm or more, number (Z) whose major axis is less than 10 nm, average major axis size, (Y / X), (Y / Z))
The test plates manufactured in Examples and Comparative Examples described later were broken with a hammer, and the cross section of the broken test plate was observed and measured using a scanning electron microscope (trade name “S-5500” manufactured by Hitachi, Ltd.). did.
After fixing the test plate to the sample stage, the cross section of the test plate was Pt-coated (about 3 nm thick) by ion sputtering.
Next, a naphthalene protective film (thickness of about 200 nm) was applied to the coated surface using a naphthalene coater.
Thereafter, the AR layer was subjected to microsampling processing using a FIB processing apparatus, and a processed piece was picked up.
The picked-up work piece was fixed to a grid and processed into a thin piece (about 100 nmt) to obtain a microscopic sample.
The measurement magnification was 100,000, and the pores in the coating film were specified from the obtained image.
Furthermore, the measurement magnification was set to 100,000 times, the major axis of all pores existing in the film having a width of 1250 nm of the obtained image was measured, and the average value of the major axis (average major axis size) was calculated.
Further, the number of holes having a major axis of 20 nm or more (Y) and the number of holes having a major axis of less than 20 nm (X) were counted.
The abundance ratio (Y / X) was calculated from the number.
Similarly, the number (Z) of vacancies whose major axis was less than 10 nm was counted. The abundance ratio (Y / Z) was calculated from the number.

((Property 5) Void volume ratio (%) and film thickness (nm))
For the coating film of the test plate manufactured in the examples and comparative examples described later, using a reflection spectral film thickness meter (manufactured by Otsuka Electronics: FE-3000), the reflectance for each wavelength of 230 to 800 nm is measured, The refractive index of the glass substrate was measured using the back side of the glass substrate.
Next, the interference with the glass substrate and the coating thin film for each wavelength of 230 to 800 nm on the coating film side is measured, and the measured values are fitted by the least square method, and the refractive index and film thickness of the coating film are measured. (Nm) was determined.
Furthermore, the refractive index of air was set to 1, the refractive index of silica was set to 1.46, and the void volume ratio was obtained from the following formula (8).
(Void volume ratio) = (1.46- (refractive index of coating film)) / (1.46-1) × 100 (8)

[Characteristic evaluation method]
(Evaluation 1) Total light transmittance (%)
About the test plates manufactured in Examples and Comparative Examples described later, the total light transmittance is measured using a turbidimeter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd. in accordance with the method defined in JIS K7361-1. It was measured.
It has good characteristics as a coating film for solar cells that can contribute to the output of the solar cell if the transmittance is 1.5% or more, compared to the transmittance of 91.7% of the test plate (glass) without the coating film. It was judged that
In Table 1 and Table 2, the difference with the transmittance | permeability of the test board (glass) without a coating film was shown as AR (%).

(Evaluation 2) Total light transmittance (%) after high temperature and high humidity, low temperature cycle test (HF test)
About the test board manufactured by the Example and comparative example which are mentioned later, the temperature environment which makes it heat up and cools in the temperature range from -40 degreeC to 85 degreeC using an acceleration environment tester (Espec Co., Ltd. make, EHS-411). It was.
A condensation freezing test was performed by repeating the cycle of leaving to stand at a temperature of 85 ° C. and humidity of 85% for 20 hours, cooling to −40 ° C., leaving to stand for 0.5 hours, and raising the temperature to 85 ° C. for 10 cycles.
The temperature raising and lowering rates were each 10 ° C./sec.
The total light transmittance of the test plate after the HF test was measured according to the method described in (Evaluation 1) above.
If the decrease in the total light transmittance after the HF test was less than 1%, the HF test resistance was judged to be good.
In Tables 1 and 2, the difference between the transmittance of the test plate (glass) without the coating film is shown as AR (%), and the difference between the initial value and the AR (%) after the HF test is expressed as “AR change rate”. % ".

(Evaluation 3) Pencil Hardness Using a test pencil specified by JIS S6006, the pencil hardness at 1 kg load was evaluated according to the pencil hardness evaluation method specified by JIS K5400.

(Evaluation 4) Water contact angle A drop of deionized water (1.0 μL) was placed on the surface of the optical coating film and allowed to stand at 20 ° C. for 10 seconds.
Thereafter, the water contact angle was measured using a CA-X150 contact angle meter manufactured by Kyowa Interface Science Co., Ltd.
The smaller the water contact angle with respect to the optical coating film, the higher the hydrophilicity of the film surface.

(Synthesis example)
Hereinafter, synthesis examples of the polymer emulsion particles (B) used in Examples and Comparative Examples described later are described.

(Synthesis Example 1) Polymer Emulsion Particles (B-1) Synthesis of Aqueous Dispersion 1600 g of ion-exchanged water and 7 g of dodecylbenzenesulfonic acid are charged into a reactor having a reflux condenser, a dropping tank, a thermometer and a stirring device. Then, the mixture was heated to 80 ° C. with stirring to obtain a mixed liquid (1).
A mixture (2) obtained by mixing 185 g of dimethyldimethoxysilane and 117 g of phenyltrimethoxysilane (b1-3) as a raw material for the core layer into the mixture (1) thus obtained was adjusted to a temperature in the reaction vessel. It dropped over about 2 hours in the state kept at 80 degreeC, and the liquid mixture (3) was obtained.
Thereafter, the mixed liquid (3) was stirred for about 1 hour while the temperature in the reaction vessel was 80 ° C.
Next, 150 g of butyl acrylate, 30 g of tetraethoxysilane (b1-3), 145 g of phenyltrimethoxysilane (b1-3), and 3-methacryloxypropyl as raw materials for the shell layer were added to the obtained mixed liquid (3). Mixed liquid (4) obtained by mixing 1.3 g of trimethoxysilane (b1-3), 165 g of diethylacrylamide, 3 g of acrylic acid, reactive emulsifier (trade name “Adekaria Soap SR-1025”, Asahi Denka A mixed solution (5) obtained by mixing 13 g manufactured by Co., Ltd., 25% by weight solid content aqueous solution), 40 g of 2% by weight aqueous solution of ammonium persulfate, and 1900 g of ion-exchanged water was set at a temperature of 80 in the reaction vessel. The mixture (6) was obtained by simultaneously dropping over about 2 hours while maintaining the temperature.
Further, as a heat curing, the mixture (6) was stirred for about 2 hours while the temperature in the reaction vessel was 80 ° C.
Thereafter, the mixture (6) was cooled to room temperature, filtered through a 100-mesh wire mesh, the concentration was adjusted with purified water, and an aqueous dispersion (solid content) of polymer emulsion particles (B-1) having a number average particle diameter of 87 nm. 10% by mass, pH 3.2) was obtained.

(Synthesis Example 2) Synthesis of Polymer Emulsion Particles (B-2) Aqueous Dispersion 1600 g of ion-exchanged water and 22 g of dodecylbenzenesulfonic acid are charged into a reactor having a reflux condenser, a dropping tank, a thermometer and a stirring device. Then, the mixture was heated to 80 ° C. with stirring to obtain a mixed liquid (1).
The mixture (2) obtained by mixing 185 g of dimethyldimethoxysilane and 151 g of phenyltrimethoxysilane (b1-3) as a raw material for the core layer into the mixture (1) thus obtained was adjusted to a temperature in the reaction vessel. It dropped over about 2 hours in the state maintained at 80 degreeC, and the liquid mixture (3) was obtained.
Thereafter, the mixed liquid (3) was stirred for about 1 hour while the temperature in the reaction vessel was 80 ° C.
Next, 150 g of butyl acrylate, 30 g of tetraethoxysilane (b1-3), 145 g of phenyltrimethoxysilane (b1-3), and 3-methacryloxypropyl as raw materials for the shell layer were added to the obtained mixed liquid (3). Mixed liquid (4) obtained by mixing 1.3 g of trimethoxysilane (b1-3), 165 g of diethylacrylamide, 3 g of acrylic acid, reactive emulsifier (trade name “Adekaria Soap SR-1025”, Asahi Denka A mixed solution (5) obtained by mixing 13 g manufactured by Co., Ltd., 25% by weight solid content aqueous solution), 40 g of 2% by weight aqueous solution of ammonium persulfate, and 1900 g of ion-exchanged water was set at a temperature of 80 in the reaction vessel. The mixture (6) was obtained by simultaneously dropping over about 2 hours while maintaining the temperature.
Further, as a heat curing, the mixture (6) was stirred for about 2 hours while the temperature in the reaction vessel was 80 ° C.
Thereafter, the mixture (6) was cooled to room temperature, filtered through a 100-mesh wire mesh, the concentration was adjusted with water, and an aqueous dispersion (solid content) of polymer emulsion particles (B-2) having a number average particle diameter of 30 nm. 10% by mass, pH 3.2) was obtained.

(Synthesis Example 3) Synthesis of Polymer Emulsion Particles (B-3) Aqueous Dispersion 1600 g of ion-exchanged water and 15 g of dodecylbenzene sulfonic acid are charged into a reactor having a reflux condenser, a dropping tank, a thermometer and a stirrer. Then, the mixture was heated to 80 ° C. with stirring to obtain a mixed liquid (1).
A mixture (2) obtained by mixing 185 g of dimethyldimethoxysilane and 117 g of phenyltrimethoxysilane (b1-3) as a raw material for the core layer into the mixture (1) thus obtained was adjusted to a temperature in the reaction vessel. It dropped over about 2 hours in the state maintained at 80 degreeC, and the liquid mixture (3) was obtained.
Thereafter, the mixed liquid (3) was stirred for about 1 hour while the temperature in the reaction vessel was 80 ° C.
Next, 150 g of butyl acrylate, 30 g of tetraethoxysilane (b1-3), 105 g of phenyltrimethoxysilane (b1-3) and 3-methacryloxypropyl as raw materials for the shell layer were added to the obtained mixed liquid (3). Mixed liquid (4) obtained by mixing 1.3 g of trimethoxysilane (b1-3), 165 g of diethylacrylamide, 3 g of acrylic acid, reactive emulsifier (trade name “Adekaria Soap SR-1025”, Asahi Denka A mixed solution (5) obtained by mixing 13 g manufactured by Co., Ltd., 25% by weight solid content aqueous solution), 40 g of 2% by weight aqueous solution of ammonium persulfate, and 1900 g of ion-exchanged water was set at a temperature of 80 in the reaction vessel. The mixture (6) was obtained by simultaneously dropping over about 2 hours while maintaining the temperature.
Further, as a heat curing, the mixture (6) was stirred for about 2 hours while the temperature in the reaction vessel was 80 ° C.
Thereafter, the mixture (6) is cooled to room temperature, filtered through a 100-mesh wire mesh, the concentration is adjusted with purified water, and an aqueous dispersion (solid content) of polymer emulsion particles (B-3) having a number average particle diameter of 45 nm. 10% by mass, pH 3.2) was obtained.

(Synthesis Example 4) Synthesis of Polymer Emulsion Particles (B-4) Aqueous Dispersion 1600 g of ion-exchanged water and 4 g of dodecylbenzenesulfonic acid are charged into a reactor having a reflux condenser, a dropping tank, a thermometer and a stirrer. Then, the mixture was heated to 80 ° C. with stirring to obtain a mixed liquid (1).
The mixture (2) obtained by mixing 185 g of dimethyldimethoxysilane and 72 g of phenyltrimethoxysilane (b1-3) as a raw material for the core layer into the mixture (1) thus obtained was adjusted to a temperature in the reaction vessel. It dropped over about 2 hours in the state maintained at 80 degreeC, and the liquid mixture (3) was obtained.
Thereafter, the mixed liquid (3) was stirred for about 1 hour while the temperature in the reaction vessel was 80 ° C.
Next, 150 g of butyl acrylate, 30 g of tetraethoxysilane (b1-3), 92 g of phenyltrimethoxysilane (b1-3), and 3-methacryloxypropyl as raw materials for the shell layer were added to the obtained mixed liquid (3). Mixture (4) obtained by mixing 1.3 g of trimethoxysilane (b1-3), 165 g of diethyl acrylamide, 3 g of acrylic acid, reactive emulsifier (trade name “Adekari Soap SR-1025”, Asahi Denka A mixed solution (5) obtained by mixing 13 g manufactured by Co., Ltd., 25% by weight solid content aqueous solution), 40 g of 2% by weight aqueous solution of ammonium persulfate, and 1900 g of ion-exchanged water was set at a temperature of 80 in the reaction vessel. The mixture (6) was obtained by simultaneously dropping over about 2 hours while maintaining the temperature.
Further, as a heat curing, the mixture (6) was stirred for about 2 hours while the temperature in the reaction vessel was 80 ° C. Thereafter, the mixture (6) is cooled to room temperature, filtered through a 100-mesh wire mesh, the concentration is adjusted with purified water, and an aqueous dispersion (solid content) of polymer emulsion particles (B-4) having a number average particle diameter of 140 nm. 10% by mass, pH 3.2) was obtained.

(Synthesis Example 5) Synthesis of Polymer Emulsion Particles (B-5) Water Dispersion In a reactor having a reflux condenser, a dropping tank, a thermometer and a stirring device, 2600 g of ion-exchanged water, 5 g of dodecylbenzenesulfonic acid, poly After adding 10 parts by mass of a 25% aqueous solution of oxyethylene nonylphenyl ether (Emulgen 950, manufactured by Kao Corporation), the mixture was heated to 80 ° C. with stirring to obtain a mixed solution (1).
In the obtained mixed liquid (1), 18 g of methacrylic acid, 216 g of methyl methacrylate, 216 g of butyl acrylate, and 6.9 g of 3-methacryloxypropyltrimethoxysilane (b1-3) as a raw material for the core layer, methyltrimethoxy A mixture (2) obtained by mixing 101 g of silane (b1-3) and 40 g of a 2 mass% aqueous solution of ammonium persulfate was dropped over about 2 hours while maintaining the temperature in the reaction vessel at 80 ° C. A liquid mixture (3) was obtained.
Thereafter, the mixed liquid (3) was stirred for about 1 hour while the temperature in the reaction vessel was 80 ° C.
Next, 245 g of butyl acrylate, 245 g of methyl methacrylate, 10 g of acrylic acid, a reactive emulsifier (trade name “ADEKA rear soap SR-1025”, Asahi Denka ( Co., Ltd., 25% by weight solids aqueous solution) 13 g, 40 g of 2% by weight ammonium persulfate aqueous solution, and 1900 g of ion-exchanged water (4) were mixed, and the temperature in the reaction vessel was brought to 80 ° C. The mixture (5) was obtained by simultaneously dropping over about 2 hours while maintaining the state.
Further, as a heat curing, the mixture (5) was stirred for about 2 hours while the temperature in the reaction vessel was 80 ° C.
Thereafter, the mixture (5) is cooled to room temperature, filtered through a 100-mesh wire mesh, the concentration is adjusted with purified water, and an aqueous dispersion (solid content) of polymer emulsion particles (B-5) having a number average particle diameter of 120 nm. 10% by mass) was obtained.

(Synthesis Example 6) Synthesis of Polymer Emulsion Particles (B-6) Aqueous Dispersion In a reactor having a reflux condenser, a dropping tank, a thermometer and a stirring device, 2600 g of ion-exchanged water, 12 g of dodecylbenzenesulfonic acid, poly After adding 20 parts by mass of a 25% aqueous solution of oxyethylene nonylphenyl ether (Emulgen 950, manufactured by Kao Corporation), the mixture was heated to 80 ° C. with stirring to obtain a mixed solution (1).
A mixed liquid (2) obtained by mixing 18 g of methacrylic acid, 216 g of methyl methacrylate, 216 g of butyl acrylate, and 40 g of a 2 mass% ammonium persulfate aqueous solution as a raw material for the core layer into the obtained mixed liquid (1). It dropped over about 2 hours in the state which maintained the temperature in reaction container at 80 degreeC, and obtained the liquid mixture (3).
Thereafter, the mixed liquid (3) was stirred for about 1 hour while the temperature in the reaction vessel was 80 ° C.
Next, 245 g of butyl acrylate, 245 g of methyl methacrylate, 10 g of acrylic acid, and 6.9 g of 3-methacryloxypropyltrimethoxysilane (b1-3) as raw materials for the shell layer were added to the obtained mixed liquid (3). 101 g of methyltrimethoxysilane (b1-3), 13 g of reactive emulsifier (trade name “Adekaria Soap SR-1025”, manufactured by Asahi Denka Co., Ltd., 25 mass% solid content aqueous solution), 40 g of 2 mass% aqueous solution of ammonium persulfate And a mixture (4) obtained by mixing 1900 g of ion-exchanged water were simultaneously added dropwise over about 2 hours while maintaining the temperature in the reaction vessel at 80 ° C. to obtain a mixture (5).
Further, as a heat curing, the mixture (5) was stirred for about 2 hours while the temperature in the reaction vessel was 80 ° C.
Thereafter, 0.1N aqueous ammonia was gradually added and stirred until the pH of the mixture reached 8. The mixture (5) was filtered through a 100-mesh wire mesh, and the concentration was adjusted with purified water to obtain an aqueous dispersion (solid content 10% by mass) of polymer emulsion particles (B-6) having a number average particle size of 120 nm. .

(Synthesis Example 7) Synthesis of Polymer Emulsion Particles (B-7) Water Dispersion In a reactor having a reflux condenser, a dropping tank, a thermometer and a stirring device, 2600 g of ion-exchanged water, 12 g of dodecylbenzenesulfonic acid, poly After adding 10 parts of a 25% aqueous solution of oxyethylene nonylphenyl ether (Emulgen 950, manufactured by Kao Corporation), the mixture was heated to 80 ° C. with stirring to obtain a mixed solution (1).
A mixed liquid (2) obtained by mixing 18 g of methacrylic acid, 216 g of methyl methacrylate, 216 g of butyl acrylate, and 40 g of a 2 mass% ammonium persulfate aqueous solution as a raw material for the core layer into the obtained mixed liquid (1). It dropped over about 2 hours in the state which maintained the temperature in reaction container at 80 degreeC, and obtained the liquid mixture (3).
Thereafter, the mixed liquid (3) was stirred for about 1 hour while the temperature in the reaction vessel was 80 ° C.
Next, 245 g of butyl acrylate, 245 g of methyl methacrylate, 10 g of acrylic acid, 101 g of methyltrimethoxysilane (b1-3), reactive emulsifier (trade name “ ADEKA rear soap SR-1025 ", manufactured by Asahi Denka Co., Ltd., solid content 25% by weight aqueous solution) 13g, ammonium persulfate 2% by weight aqueous solution 40g, and mixed solution (4) obtained by mixing 1900g of ion-exchanged water Were simultaneously added dropwise over about 2 hours while maintaining the temperature in the reaction vessel at 80 ° C. to obtain a mixture (5).
Further, as a heat curing, the mixture (5) was stirred for about 2 hours while the temperature in the reaction vessel was 80 ° C.
Thereafter, 0.1N aqueous ammonia was gradually added and stirred until the pH of the mixture reached 8. The mixture (5) was filtered through a 100-mesh wire mesh, and the concentration was adjusted with purified water to obtain an aqueous dispersion of polymer emulsion particles (B-7) having a number average particle diameter of 140 nm (solid content 10% by mass). .

(Synthesis Example 8) Synthesis of Polymer Emulsion Particles (B-8) Aqueous Dispersion 1600 g of ion-exchanged water and 44 g of dodecylbenzenesulfonic acid were charged into a reactor having a reflux condenser, a dropping tank, a thermometer and a stirrer. Then, the mixture was heated to 80 ° C. with stirring to obtain a mixed liquid (1).
The mixture (2) obtained by mixing 185 g of dimethyldimethoxysilane and 151 g of phenyltrimethoxysilane (b1-3) as a raw material for the core layer into the mixture (1) thus obtained was adjusted to a temperature in the reaction vessel. It dropped over about 2 hours in the state maintained at 80 degreeC, and the liquid mixture (3) was obtained.
Thereafter, the mixed liquid (3) was stirred for about 1 hour while the temperature in the reaction vessel was 80 ° C.
Next, 150 g of butyl acrylate, 30 g of tetraethoxysilane (b1-3), 145 g of phenyltrimethoxysilane (b1-3), and 3-methacryloxypropyl as raw materials for the shell layer were added to the obtained mixed liquid (3). Mixed liquid (4) obtained by mixing 1.3 g of trimethoxysilane (b1-3), 165 g of diethylacrylamide, 3 g of acrylic acid, reactive emulsifier (trade name “Adekaria Soap SR-1025”, Asahi Denka A mixed solution (5) obtained by mixing 13 g manufactured by Co., Ltd., 25% by weight solid content aqueous solution), 40 g of 2% by weight aqueous solution of ammonium persulfate, and 1900 g of ion-exchanged water was set at a temperature of 80 in the reaction vessel. The mixture (6) was obtained by simultaneously dropping over about 2 hours while maintaining the temperature.
Further, as a heat curing, the mixture (6) was stirred for about 2 hours while the temperature in the reaction vessel was 80 ° C.
Thereafter, the mixture (6) was cooled to room temperature, filtered through a 100-mesh wire mesh, the concentration was adjusted with water, and an aqueous dispersion (solid content) of polymer emulsion particles (B-8) having a number average particle diameter of 20 nm. 8% by mass, pH 2.8) was obtained.

[Example 1]
As the polymer emulsion particles (B), an aqueous dispersion of the polymer emulsion particles (B-1) synthesized in (Synthesis Example 1) was used.
As a raw material for spherical silica (A), water-dispersed colloidal silica having an average particle size of 5 nm (trade name “Snowtex OXS” (described as “ST-OXS” in Table 1) ”, manufactured by Nissan Chemical Industries, Ltd., solid Min. 10% by weight).
Tetraethoxysilane (TEOS manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the hydrolyzable silicon compound (C).
These were adjusted and mixed so that it might become the solid content mass ratio of Table 1, and after adjusting with 20% ethanol water so that the whole solid content might be 2 mass%, it stirred, coating composition (E -1) was obtained.
The above coating composition (E-1) is applied to the surface of the base material (5 cm × 5 cm solar cell glass: Asahi Glass's Solite total light transmittance 91.7%) on which the sunlight enters, a spin coater Was applied at a rotational speed of 1500 rpm for 10 seconds to a film thickness of 100 nm, dried at 25 ° C. for 60 minutes, further sintered in an electric furnace at 600 ° C. for 3 minutes, then rapidly cooled and applied. A test plate (G-1) having a membrane (F-1) was obtained.
At this time, the composition ratio in the coating film (F-1) (similar to the mass ratio of each component calculated in terms of solid content of the coating composition) is (A) / (B ′) / (C ′) = 100 / It became 60/50.
In addition, (A) is a mass ratio of silica (A), and (B ′) is a mass ratio of polymer particles (B ′) derived from the polymer emulsion particles (B) obtained after the sintering. Yes, (C ′) is the mass ratio of the hydrolyzable condensate (C ′) of the hydrolyzable silicon compound (C) obtained after the sintering.
The void | hole is indefinite shape and the evaluation result of the obtained test board (G-1) is shown in Table 1.

[Example 2]
The composition ratio in the coating film corresponding to the coating film (F-1) (similar to the mass ratio of each component calculated in terms of solid content of the coating composition) is (A) / (B ′) / (C ′ ) = 40/110/50 The mixing amount was adjusted.
Other conditions were the same as in Example 1 to obtain a test plate (G-2).
The evaluation results of the obtained test plate (G-2) are shown in Table 1.

Example 3
As the polymer emulsion particles (B), an aqueous dispersion of the polymer emulsion particles (B-2) synthesized in the above (Synthesis Example 2) was used.
Other conditions were the same as in [Example 1] to obtain a test plate (G-3).
The evaluation results of the obtained (G-3) are shown in Table 1.

Example 4
As the polymer emulsion particles (B), an aqueous dispersion of the polymer emulsion particles (B-3) synthesized in the above (Synthesis Example 3) was used.
Other conditions were the same as in [Example 1] to obtain a test plate (G-4).
The evaluation results of the obtained (G-4) are shown in Table 1.

Example 5
As a raw material for spherical silica (A), water-dispersed colloidal silica having an average particle diameter of 10 nm (trade name “Snowtex OS (indicated in Table 1 as“ ST-OS ”)”), manufactured by Nissan Chemical Industries, Ltd. , Solid content 20% by mass).
Other conditions were the same as in [Example 4] to obtain a test plate (G-5).
The evaluation results of the obtained test plate (G-5) are shown in Table 1.

Example 6
The composition ratio of each component of the coating film (similar to the mass ratio of each component calculated in terms of solid content of the coating composition) is (A) / (B ′) / (C ′) = 100/200/60. The mixing amount was adjusted as follows.
Other conditions are the same as in [Example 5], and the evaluation results of the test plate (G-6) are shown in Table 1.
The evaluation results of the obtained test plate (G-6) are shown in Table 1.

Example 7
An aqueous dispersion of the polymer emulsion particles (B-4) synthesized in the above (Synthesis Example 4) was used as the polymer emulsion particles (B).
The composition ratio of each component (similar to the mass ratio of each component calculated in terms of solid content of the coating composition) is mixed so that (A) / (B ′) / (C ′) = 50/100/50 The amount was adjusted.
Other conditions were the same as in [Example 1] to obtain a test plate (G-7).
The evaluation results of the obtained test plate (G-7) are shown in Table 1.

[Comparative Example 1]
As the polymer emulsion particle (B), an aqueous dispersion of the polymer emulsion particle (B-5) synthesized in the above (Synthesis Example 5) was used.
Other conditions were the same as in [Example 7] to obtain a test plate (G-8).
Table 2 shows the evaluation results of the obtained test plate (G-8).

[Comparative Example 2]
As the polymer emulsion particles (B), an aqueous dispersion of the polymer emulsion particles (B-6) synthesized in the above (Synthesis Example 6) was used.
Other conditions were the same as in [Example 1] to obtain a test plate (G-9).
Table 2 shows the evaluation results of the obtained test plate (G-9).

[Comparative Example 3]
As the polymer emulsion particles (B), an aqueous dispersion of the polymer emulsion particles (B-7) synthesized in (Synthesis Example 7) was used.
Other conditions were the same as in [Example 1] to obtain a test plate (G-10).
The evaluation result of the obtained test plate (G-10) is shown in Table 2.

[Comparative Example 4]
Using the aqueous dispersion of the polymer emulsion particles (B-6) synthesized in the above (Synthesis Example 6) as the polymer emulsion particles (B), an aqueous dispersion having an average particle diameter of 4 nm as a raw material for the spherical silica (A) Colloidal silica (trade name “NALCO1115”, manufactured by Nalco Company, solid content 16.5% by mass) was used.
These were adjusted and mixed so that it might become mass ratio of solid content of Table 2, and after adjusting with 20% ethanol water so that the whole solid content might be 2 mass%, it stirred, and coating composition (E -11) was obtained.
The above coating composition (E-11) is applied to the surface of the base material (5 cm × 5 cm solar cell glass: Asahi Glass's Solite total light transmittance 91.7%) on which the sunlight is incident. After applying for 10 seconds at a rotation speed of 1500 rpm, the sample was dried at 25 ° C. for 60 minutes, further sintered in an electric furnace at 600 ° C. for 3 minutes, and then rapidly cooled to obtain a test plate having a coating film (F-11) ( G-11) was obtained.
At this time, the composition ratio in the coating film (F-11) (similar to the mass ratio of each component calculated in terms of solid content of the coating composition) is (A) / (B ′) / (C ′) = It adjusted so that it might become 90/10/0.
Other conditions were the same as in Example 1 to obtain a test plate (G-11).
The evaluation results of the obtained test plate (G-11) are shown in Table 2.

[Comparative Example 5]
As the polymer emulsion particles (B), an aqueous dispersion of the polymer emulsion particles (B-7) synthesized in the above (Synthesis Example 7) is used, and an aqueous dispersion having an average particle diameter of 4 nm is used as a raw material for the spherical silica (A). Colloidal silica (trade name “NALCO1115”, manufactured by Nalco Company, solid content of 16.5% by mass) was mixed at a solid content mass ratio shown in Table 2.
Then, it adjusted to pH2.5 with 0.1N hydrochloric acid aqueous solution, and also adjusted with 20% ethanol water so that solid content might be 2 mass%, and obtained coating composition (E-12).
The above coating composition (E-12) is applied to the surface of the substrate (5 cm × 5 cm glass for solar cell: Asahi Glass's Solite total light transmittance 91.7%) on which sunlight is incident. Was applied at a rotational speed of 1500 rpm for 10 seconds to a film thickness of 100 nm, dried at 25 ° C. for 60 minutes, further sintered in an electric furnace at 600 ° C. for 3 minutes, then rapidly cooled and applied. A test plate (G-12) having a membrane (F-12) was obtained.
At this time, the composition ratio in the coating film (F-12) (similar to the mass ratio of each component calculated in terms of solid content of the coating composition) is (A) / (B ′) / (C ′) = It adjusted so that it might become 90/10/0.
Other conditions were the same as in [Example 1] to obtain a test plate (G-12).
Table 2 shows the evaluation results of the obtained test plate (G-12).

[Comparative Example 6]
As the polymer emulsion particles (B), an aqueous dispersion of the polymer emulsion particles (B-7) synthesized in the above (Synthesis Example 8) is used, and an aqueous dispersion having an average particle diameter of 4 nm is used as a raw material for the spherical silica (A). Colloidal silica (trade name “NALCO1115”, manufactured by Nalco Company, solid content 16.5% by mass) was used.
Other conditions were the same as in [Example 1] to obtain a test plate (G-13).
Table 2 shows the evaluation results of the obtained test plate (G-13).

Tables 1 and 2 show the evaluation results of Examples 1 to 7 and Comparative Examples 1 to 6 described above.
In Table 2, in the right end column, the base materials used in Examples 1 to 7 and Comparative Examples 1 to 5 (5 cm × 5 cm solar cell glass: Asahi Glass Solite total light transmittance 91.7%) Only the total light transmittance and water contact angle data are shown.
In Examples 1-7, the coating film which can maintain an anti-reflective characteristic for a long time in a high-temperature, high-humidity environment was obtained, making high anti-reflective characteristic and high mechanical strength compatible.

  The optical coating film of the present invention is an antireflection film of a member that needs to improve light transmittance and prevent reflection of solar cells, photovoltaic cells, liquid crystal displays, glasses, window glass, televisions, etc. It has industrial applicability as an antifouling coat.

Claims (8)

A coating film mainly composed of silica,
Has holes,
The average value of the major axis of the holes is 5 to 300 nm,
The ratio (Y / X) of the number of holes having a major axis of less than 20 nm (X) to the number of holes having a major axis of 20 nm or more (Y) per unit cross-sectional area of the coating film is 0.3-3. 0.0, the coating film.   The ratio (Y / Z) of the number of holes having a major axis of less than 10 nm (Z) to the number of holes having a major axis of 20 nm or more (Y) per unit sectional area of the coating film is 1.0 to 10. The coating film according to claim 1, which is 0.0.   The coating film of Claim 1 or 2 whose volume ratio of the said void | hole in the said coating film is 20-60 vol%.   The coating film according to any one of claims 1 to 3, which is an antireflection film. It is a manufacturing method of the coating film as described in any one of Claims 1 thru | or 4, Comprising:
Applying and drying a coating composition comprising silica (A) and polymer emulsion particles (B); and
Sintering at a temperature of 500 ° C. or higher;
The manufacturing method of the coating film which has.   The glass for solar cells containing the coating film as described in any one of Claims 1 thru | or 4.   The solar cell module containing the coating film as described in any one of Claims 1 thru | or 4.   The condensing lens for solar cells containing the coating film as described in any one of Claims 1 thru | or 4.