JP2014203006A - Optical coating film, method for producing the same, and antireflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical coating film capable of maintaining an antireflection characteristic for a long period of time under a high humidity environment.SOLUTION: There is provided the optical coating film which comprises a coating film formed on a base material. The coating film includes voids (X) each of which has a major axis (L) and minor axis perpendicular to the major axis, an average of the major axis (L) and the maximum minor axis (D): ((L+D)/2) being 20 nm or more and the major axis (L) and minor axis (D) of the voids satisfying 1<L/D. The voids (X) are not in contact with the base material at a boundary with the base material.

Description

  The present invention relates to an optical coating film, a method for producing an optical coating film, and an antireflection film.

  Conventionally, many of the antireflection films, which are optical coating films, are manufactured by a first process for forming a coating film and a second process for forming voids in the coating film. Thus, after forming a coating film, the antireflection film reduces the refractive index of the coating film and decreases the reflectance by forming voids in the coating film.

  For example, Patent Documents 1 to 4 disclose a porous body in which voids are introduced into a coating film using a pore-causing agent.

  Further, in Patent Documents 5 to 7, as a method of forming a low refractive index porous body that does not require extraction of the porous material from the coating film, a porous coating solution containing a chain metal oxide is used. A method for depositing a body is disclosed.

  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, an aqueous polymer dispersion excellent in mechanical strength, transparency, weather resistance, chemical resistance, optical properties, antifouling property, antifogging property, antistatic property and the like was used. A coating 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, when the porous causative agent used for forming the voids is removed in the extraction step, the film swells, causing poor appearance of the voids 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 film disclosed in Patent Document 9 has a problem that there is room for improvement in antireflection properties. Furthermore, the coating composition disclosed in Patent Document 11 has a problem that there is room for improvement in antireflection properties.

  In general, it is known that an antireflection film based on glass elutes alkali components from the inside of the glass in a humid environment. And has a problem of insufficient weather resistance such as lowering the antireflection effect.

  In view of the above-described problems of the prior art, an object of the present invention is to provide an optical coating film that can maintain excellent antireflection characteristics even in a humid environment.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that in the optical coating film having voids inside, the average value of the major axis (L) of the void (X) and the maximum value (D) of the minor axis perpendicular thereto By specifying the (average void size), the ratio (L / D) of the major axis (L) and minor axis (D) of the void (X), and the state between the void (X) and the substrate interface, a humid environment The inventors have found that an optical coating film capable of maintaining antireflection characteristics for a long period of time is obtained, and have completed the present invention.
That is, the present invention is as follows.

[1]
An optical coating consisting of a coating formed on a substrate,
In the coating film, the average value of the major axis (L) and the maximum value of the minor axis perpendicular to it (D): ((L + D) / 2) has a gap (X) of 20 nm or more,
The major axis (L) and minor axis (D) of the void (X) are 1 <L / D,
An optical coating film in which the gap (X) is not in contact with the base material at the interface with the base material.
[2]
The optical coating film according to [1], further including a void (Y) having an average void size of less than 20 nm around the void (X).
[3]
The optical coating film is formed by applying a coating composition containing a metal oxide (A) and polymer emulsion particles (B) and drying the precursor of the optical coating film at a temperature of 600 ° C. or higher. The optical coating film according to [1] or [2], which is formed by bonding.
[4]
The polymer emulsion particles (B) are particles having a core / shell layer structure,
The polymer emulsion particles (B) include a hydrolyzable silicon compound (b1) and a vinyl monomer (b2) having a secondary and / or tertiary amide group as a polymer monomer,
The ratio of the hydrolyzable silicon compound (b1-3) containing 3 or more hydrolyzable functional groups in the core layer is such that the vinyl monomer (b2) having the secondary and / or tertiary amide group In a mass ratio to the total amount with the hydrolyzable silicon compound (b1),
The optical coating film according to any one of [1] to [3], wherein (b1-3) / ((b1) + (b2)) ≧ 0.20.
[5]
The polymer emulsion particles (B) are particles having a core / shell layer structure,
The polymer emulsion particles (B) include a hydrolyzable silicon compound (b1) and a vinyl monomer (b2) having a secondary and / or tertiary amide group as a polymerization monomer,
The ratio of the hydrolyzable silicon compound (b1-3) containing three or more hydrolyzable functional groups in the shell layer is such that the vinyl monomer (b2) having the secondary and / or tertiary amide group has In a mass ratio to the total amount with the hydrolyzable silicon compound (b1),
0.01 <(b1-3) / ((b1) + (b2)) <0.20
The optical coating film according to any one of [1] to [4].
[6]
Applying a coating composition comprising a metal oxide (A) and polymer emulsion particles (B) and drying to form a precursor of an optical coating;
Sintering the precursor at a temperature of 500 ° C. or higher to form an optical coating;
A method for producing an optical coating film comprising:
[7]
The optical coating film according to any one of [1] to [5], wherein the optical coating film is an antireflection film.
[8]
Glass for solar cells, comprising the antireflection film according to [7].
[9]
A solar cell module comprising the antireflection film according to [7].
[10]
A condensing lens for a solar cell comprising the antireflection film according to [7].

  ADVANTAGE OF THE INVENTION According to this invention, the optical coating film which can maintain an antireflection characteristic for a long period of time in a humid environment is obtained.

  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.

[Optical coating]
The optical coating film of the present embodiment is composed of a coating film formed on a predetermined substrate, and in the coating film, the average value of the major axis (L) and the maximum value (D) of the minor axis perpendicular thereto. (Hereinafter, described as the average void size): ((L + D) / 2) has voids (X) of 20 nm or more.
The major axis (L) and minor axis (D) of the gap (X) satisfy 1 <L / D.
The gap (X) is not in contact with the base material at the interface with the base material.

(Base material)
The optical coating film of this embodiment consists of a coating film formed on a predetermined substrate.
The substrate can be variously selected according to the use of the optical coating film of the present embodiment.
For example, organic base materials such as synthetic resins and natural resins, inorganic base materials such as glass, and combinations thereof can be applied. Specifically, solar cell members (glass, modules, etc.), solar cells Various members that require improved light transmission and / or prevention of reflection, such as a light collecting lens, a photovoltaic cell, a liquid crystal display, glasses, a window glass, and a television.
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)
The optical coating film of this embodiment has a gap (X) in the coating film. The void (X) is an average value (average void size) of the major axis (L) and the maximum value (D) of the minor axis perpendicular to the major axis (L) (hereinafter sometimes simply referred to as minor axis (D)): ((L + D) / 2) is 20 nm or more.
When the average gap size of the gap (X) is 20 nm or more, a high antireflection effect can be obtained. The average gap size of the gap (X) is preferably 30 nm or more, and more preferably 40 nm or more.
Here, “the maximum value of the short diameter” refers to the maximum value among them when there are a plurality of diameters orthogonal to the long diameter (X) of the air gap.
The average void size is the average value of pore distribution obtained from the nitrogen adsorption method, the pore volume, the average void size obtained from the average pore diameter, the maximum void diameter directly observed with an electron microscope, or spherical particles Can be obtained from the calculated value of the maximum void diameter in the case of dense packing. Specifically, it can be determined by the method described in Examples described later.
As a method for controlling the average void size of the voids (X) to 20 nm or more, a method for controlling the composition of the polymer emulsion particles (B) to be described later used as a void forming material, a sintering temperature, a temperature rise, etc. Examples include a method for controlling the speed.

In the optical coating film of the present embodiment, the major axis (L) of the gap (X) and the minor axis (D) have a relationship of 1 <L / D. Thereby, the effect of coating film strength is obtained.
The L / D is preferably 1.2 or more, and more preferably 1.4 or more.
As a method of controlling the ratio of the major axis (L) and the minor axis (D) of the void (X) to 1 <L / D, there is a method of controlling the degree of crosslinking of the polymer emulsion particles (B) described later. Can be mentioned.

It is preferable that the optical coating film of this embodiment further has a void (Y) having an average void size of less than 20 nm. Thereby, the effect of improving the coating film strength is obtained.
Moreover, it is preferable to have a space | gap (Y) around the said space | gap (X). Here, “periphery” means that the surface is in direct contact with the surface of the gap (X) or exists at a distance that allows chemical interaction, thereby improving the coating strength. can get.
The average gap size of the gap (Y) is preferably 10 nm or less, and more preferably less than 5 nm.
As a method of forming the void (Y) around the void (X) and controlling the average void size of the void (Y) to 10 nm or less, the particle diameter of the metal oxide (A) described later, The method of controlling the addition amount of a decomposable silicon compound (C) is mentioned.

The optical coating film of this embodiment is obtained by applying a coating composition containing a metal oxide (A) and polymer emulsion particles (B) and drying the precursor formed at a temperature of 600 ° C. or higher. It is preferable that it is formed by doing.
The optical coating film of the present embodiment includes the metal oxide (A) and the polymer emulsion particles (B) by including the metal oxide (A) and the polymer emulsion particles (B) in the coating composition. Heteroaggregation of these or aggregation of metal oxides (A) can be formed.
As a result of the removal of component (B) by sintering, voids (X) are formed, and voids (Y) are formed as voids between particles of component (A).

In the optical coating film of this embodiment, it is preferable that the coating composition further includes a hydrolyzable silicon compound (C).
By including the hydrolyzable silicon compound (C) in the coating composition, the hydrolyzable silicon compound (C) can be permeated into the voids (Y) having an average void size of less than 20 nm. The average void size of (Y) can be controlled.
In the coating composition, when the hydrolyzable silicon compound (C) is contained, the condensation reaction between the silanol group of the hydrolyzable silicon compound (C) and the hydroxyl group present on the surface of the metal oxide (A) As a result, a bond is formed, or a hydrogen bond is formed between the hydrolyzable silicon compound (C) and the metal oxide (A). Thereby, the mechanical strength of the coating film obtained from the coating composition is further increased. The hydrolyzable silicon compound (C) will be described later.

  The optical coating film of the present embodiment is antifouling against hydrophilic dirt when surface hydrophilicity is imparted due to the metal oxide (A) or the hydrolyzable silicon compound (C). Has an effect. That is, the optical coating film of the present embodiment can be washed away with rainwater even when the dirt adheres.

<Metal oxide (A)>
The metal oxide (A) preferably includes a spherical metal oxide (a1) and / or a non-spherical metal oxide (a2) having an aspect ratio (major axis / minor axis) of 3 to 25.

  Here, the spherical metal oxide (a1) refers to a metal oxide present in a particle state having 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 presence form of the spherical metal oxide (a1) may be primary particles or aggregated particles, and in the case of aggregated particles, the shape does not need to be a perfect sphere. You may have a corner | angular part.

  Here, the aspect ratio of the spherical metal oxide (a1) and the non-spherical metal oxide (a2) is measured by measuring the minor axis and the major axis of the metal oxide particles photographed with a transmission microscope (TEM), It can be determined by determining the major axis / minor axis from the measured value. The minor axis and the major axis are the short side and the long side of the circumscribed rectangle that minimizes the area circumscribing the metal oxide particles, respectively.

  Although it does not specifically limit as spherical metal oxide (a1), For example, oxides, such as silicon, aluminum, titanium, zirconium, zinc, tin, indium, gallium, germanium, antimony, molybdenum, are mentioned.

  The average particle diameter of the spherical metal oxide (a1) is preferably 1 to 100 nm, more preferably 1 to 50 nm, from the viewpoint of the transparency and mechanical strength of the optical coating film of the present embodiment. More preferably, it is 1-10 nm. Here, the average particle diameter of the spherical metal oxide (a1) is the primary particle diameter when the particles are present in the form of primary particles, and is aggregated when the particles are present in the form of aggregated particles. It refers to the particle diameter (secondary particle diameter) and can be determined by the following method. That is, the particle diameter (biaxial average) of the corresponding particles present in a transmission microscope (TEM) photograph taken by adjusting so that 100 to 200 spherical metal oxide (a1) particles are captured. It can be determined by measuring the diameter, that is, the average value of the minor axis and the major axis, and determining the average value of the measured particle diameters.

  The non-spherical metal oxide (a2) is a metal oxide having an aspect ratio (major axis / minor axis) of 3 or more, for example, a composite in which primary particles of metal oxide (fine) particles are connected in a bead shape. Examples thereof include particles, fibrous particles, acicular particles, plate-like particles, and hollow empty particles thereof.

  The non-spherical metal oxide (a2) is not particularly limited, and examples thereof include oxides such as silicon, aluminum, titanium, zirconium, zinc, tin, indium, gallium, germanium, antimony, and molybdenum.

  The non-spherical metal oxide (a2) has an aspect ratio (major axis / minor axis) of 3 to 25, preferably 3 to 15, and more preferably 3 to 10.

  The average major axis of the non-spherical metal oxide (a2) is preferably 20 to 250 nm, more preferably 30 to 150 nm, and further preferably 40 to 100 nm.

  In the optical coating film of the present embodiment, from the viewpoint of porosity and refractive index, the non-spherical metal oxide (a2) preferably has an aspect ratio (major axis / minor axis) of 3 or more, and an average major axis. Is preferably 20 nm or more. In addition, from the viewpoints of the transparency of the optical coating film and the antireflection performance, the nonspherical metal oxide (a2) preferably has an aspect ratio (major axis / minor axis) of 25 or less and an average major axis of 250 nm or less. Preferably there is.

  In addition, the average major axis of the non-spherical metal oxide (a2) is a transmission microscope (TEM) photograph taken by adjusting the non-spherical metal oxide (a2) so that 100 to 200 particles of the non-spherical metal oxide (a2) are captured. It can be determined by measuring the major axis of the corresponding particles present therein and determining the average value of the measured major axes.

  Specific examples of raw materials for forming the non-spherical metal oxide (a2) include “Snowtex-UP (registered trademark)” manufactured by Nissan Chemical Industries, Ltd. and “Snowtex-UP (registered trademark)” manufactured by the same company. “Snowtex-PSSO (registered trademark)” manufactured by the company, “Snowtex-PSS (registered trademark)” manufactured by the same company, alumina sol, pseudo-boehmite-based alumina, scaly silica “Sunlabry” manufactured by Asahi Glass Co., Ltd., and the like. This non-spherical silica sol may have a three-dimensionally curved shape.

  From the viewpoint of improving the mechanical strength and antireflection effect of the optical coating film of this embodiment, the mixing ratio (mass ratio) of the spherical metal oxide (a1) and the non-spherical metal oxide (a2) is The ratio is preferably 1: 1 to 1:40, more preferably 1: 3 to 1:20, and still more preferably 1: 3 to 1:10.

  In addition to the spherical metal oxide (a1) and the non-spherical metal oxide (a2), the coating composition for forming the optical coating film of the present embodiment includes, for example, boron, phosphorus, silicon, aluminum, and titanium. , Other metal oxides made of zirconium, zinc, tin, indium, gallium, germanium, antimony, molybdenum, and the like may be included.

<Polymer emulsion particles (B)>
The polymer emulsion particles (B) contained in the coating composition that forms the optical coating film of this embodiment are composed of a predetermined polymer. Examples of the polymer include, but are not limited to, polyurethane, polyester, poly (meth) acrylate, poly (meth) acrylate-silicone copolymer, polyvinyl acetate, polybutadiene, Polymers composed of polyvinyl chloride, chlorinated polypropylene, polyethylene, polystyrene, polystyrene- (meth) acrylate copolymers, rosin derivatives, alcohol adducts of styrene-maleic anhydride copolymers, etc. Etc.

The polymer emulsion particles (B) are obtained by polymerizing a hydrolyzable silicon compound (b1) and a vinyl monomer (b2) having a secondary and / or tertiary amide group from the viewpoint of coating strength. It is preferable to include as. Specifically, a heavy polymer obtained by polymerizing a hydrolyzable silicon compound (b1) and a vinyl monomer (b2) having a secondary and / or tertiary amide group in the presence of water and an emulsifier. More preferably, it is a combined emulsion particle.
The polymer emulsion particles (B) may be any of those obtained by polymerizing (b1) and (b2), a mixture of those obtained by polymerizing (b1) and (b2), or a composite thereof. It may be.

  From the viewpoint of transparency, the polymer emulsion particles (B) preferably have a number average particle diameter of 10 to 800 nm, more preferably 20 to 200 nm, and even more preferably 40 to 150 nm.

  In addition, the number average particle diameter of polymer emulsion particle | grains (B) can be measured by the method described in the below-mentioned Example.

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

  The interaction between the metal oxide (A) and the polymer emulsion particles (B) is not particularly limited, and examples thereof include a hydrogen bond and a chemical bond. Specifically, the hydrogen bond between the hydroxyl group of the metal oxide (A) and the secondary and / or tertiary amide group of the polymer emulsion particle (B), the hydroxyl group of the metal oxide (A), and And condensation (chemical bond) with a polymerization product of a hydrolyzable metal compound constituting the polymer emulsion particles (B).

  As described above, polymer emulsion particles are obtained by polymerizing the hydrolyzable silicon compound (b1) and the vinyl monomer (b2) having a secondary and / or tertiary amide group in the presence of water and an emulsifier. The hydrolyzable silicon compound (b1) used in the production of (B) is not limited to the following, but for example, a compound represented by the following formula (1) or a condensation product thereof, a silane cup A ring agent etc. are mentioned.

SiWxRy (1)
(In the formula (1), W represents 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, R represents at least one group selected from the group consisting of amide groups, wherein R represents a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, and a substituted group. Or at least one hydrocarbon group 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 is 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 which is an example of the hydrolyzable silicon compound (b1) is a functional group having reactivity with organic substances such as a vinyl polymerizable group, an epoxy group, an amino group, a methacryl group, a mercapto group, and an isocyanate group. Is a hydrolyzable silicon compound present in the molecule.

  Examples of the hydrolyzable silicon compound (b1) include, but are not limited to, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, and tetra-n-butoxysilane. Tetraalkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane 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 Trialkoxysilanes such as idpropyltrimethoxysilane and 3-ureidopropyltriethoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n- Propyldiethoxysilane, diisopropyldimethoxysilane, diisopropyldiethoxysilane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-pentyldimethoxysilane, di-n-pentyldiethoxysilane, di- n-hexyldimethoxysilane, di-n-hexyldiethoxysilane, di-n-heptyldimethoxysilane, di-n-heptyldiethoxysilane, di-n-octyldimethoxysilane, di-n-octyldiethoxysilane Dialkoxysilanes such as di-n-cyclohexyldimethoxysilane, di-n-cyclohexyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane; trimethylmethoxysilane, trimethyl And monoalkoxysilanes such as ethoxysilane.

  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 measurement of the condensation product is preferably 200 to 5000, more preferably 300 to 1000. is there.

  Among the hydrolyzable silicon compounds (b1) described above, a silicon alkoxide having a phenyl group, such as phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, etc. is excellent in polymerization stability in the presence of water and an emulsifier. Therefore, it is preferable.

  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-described secondary and / or Vinyl monomers having a tertiary amide group and (b2) a copolymer or a chain transfer reaction to it is possible to generate a chemical bond.

The amount of the hydrolyzable silicon compound (b1) used is preferably in the range of 0.005 or more and 0.5 or less as a mass ratio (b1) / (B) to the polymer emulsion particles (B) to be obtained.
The mass of the polymer emulsion particles (B) is the above-mentioned vinyl monomer (b2) having secondary and / or tertiary amide groups, and other vinyl monomers (b3) copolymerizable therewith. Furthermore, it is the mass of the polymerization product obtained when all of the hydrolyzable silicon compound (b1) is polymerized.

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 optical coating film of this embodiment.
The content of the hydrolyzable silicon compound (b1) is preferably 0.01% by mass or more and 50% by mass or less with respect to 100% by mass of the polymer emulsion particles (B) from the viewpoint of polymerization stability. 0.1 mass% or more and 30 mass% or less is more preferable.

  The vinyl monomer (b2) having a secondary and / or tertiary amide group used for producing the polymer emulsion particles (B) 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, Nn-propylacrylamide, N-isopropylmethacrylamide, Nn-propylmethacrylamide, N-methyl-Nn-propylacrylamide, N- Methyl-N-isopropylacryl Amide, N-acryloylpyrrolidine, N-methacryloylpyrrolidine, 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.

  The amide group of the vinyl monomer (b2) used for producing the polymer emulsion particles (B) is a secondary and / or tertiary amide group, but a vinyl monomer having a tertiary amide group is used. And the resulting polymer emulsion particles (B) are preferred because the hydrogen bonding between the metal emulsion particles (B) and the metal oxide (A) is strengthened. Among them, in particular, N, N-diethylacrylamide is very excellent in polymerization stability in the presence of water and an emulsifier, and also has hydroxyl groups and metal oxides (polymerized products of the hydrolyzable silicon compound (b1) described above ( It is more preferable because it can form a strong hydrogen bond with the hydroxyl group of A).

  In addition, as the hydrolyzable silicon compound (b1) described above, in addition to the various compounds described above, a silane coupling agent having a vinyl polymerizable group or a thiol group may be used alone or the above-described silicon alkoxide or other silane couplings. Agents, and those mixed or complexed with their condensation products can be used.

The polymerization product of the hydrolyzable silicon compound (b1) constituting the polymer emulsion particles (B) and the polymerization product of the vinyl monomer (b2) having a secondary and / or tertiary amide group are: It may be compounded by hydrogen bonding or chemical bonding.
The (b1) and (b2) are preferably combined by various bonds such as a hydrogen bond and a chemical bond, but the form and state of the bond are not limited in any way. Furthermore, the above-mentioned complexation may be performed only in 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 monomer having a secondary and / or tertiary amide group ( It is more preferable to use a polymer obtained by polymerizing b2) because 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 100 parts by mass of the vinyl monomer (b2) having a secondary and / or tertiary amide group. On the other hand, it is preferably from 0.1 to 100 parts by mass from the viewpoint of polymerization stability, more preferably from 0.5 to 50 parts by mass, and even more preferably from 0.5 to 5 parts by mass. Is preferred.

  In the optical coating film of this embodiment, the vinyl monomer (b2) having a secondary and / or tertiary amide group used for obtaining the polymer emulsion particles (B) is another vinyl copolymerizable therewith. It can be copolymerized with the monomer (b3). As a result, the properties (such as glass transition temperature, molecular weight, hydrogen bonding strength, polarity, dispersion stability, weather resistance, and compatibility of the hydrolyzable silicon compound (b1) with the polymerization product) are further improved. It becomes possible to control effectively, which is preferable.

  The other vinyl monomer (b3) copolymerizable with the vinyl monomer (b2) having a secondary and / or tertiary amide group is not limited to the following. ) In addition to acrylic esters, aromatic vinyl compounds, and cyanide vinyl compounds, carboxyl group-containing vinyl monomers, hydroxyl group-containing vinyl monomers, epoxy group-containing vinyl monomers, carbonyl group-containing vinyl monomers, and the like Examples thereof include monomers containing a functional group.

Examples of the (meth) acrylic acid ester include, but are not limited to, 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 carbon atoms. (Poly) oxyethylene di (meth) acrylate etc. are mentioned.
Examples of the (meth) acrylic acid alkyl ester having 1 to 50 carbon atoms in the alkyl part include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylic acid. Examples include 2-ethylhexyl, methyl cyclohexyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, and the like.
Examples of the (poly) oxyethylene di (meth) acrylate having 1 to 100 ethylene oxide groups include, but are not limited to, ethylene glycol di (meth) acrylate and di (meth) acrylic. Examples include diethylene glycol acid, diethylene glycol methoxy (meth) acrylate, and tetraethylene glycol di (meth) acrylate.

  In the present specification, (meth) acrylic is a simple description of methacrylic or acrylic.

  The amount of the (meth) acrylic acid ester used (when using a plurality of (meth) acrylic acid esters, the total amount) is preferably in the total vinyl monomer constituting the polymer emulsion particles (B). It is 0-99.9 mass%, More preferably, it is 5-80 mass%.

The aromatic vinyl compound as the vinyl monomer (b3) is not particularly limited, and examples thereof include styrene and vinyl toluene.
The aromatic vinyl compound is preferably 0 to 99.9% by mass, and more preferably 5 to 80% by mass in the total vinyl monomers constituting the polymer emulsion particles (B).

The vinyl cyanide compound as the vinyl monomer (b3) is not particularly limited, and examples thereof include acrylonitrile and methacrylonitrile.
The vinyl cyanide compound is preferably 0 to 99.9% by mass, and more preferably 5 to 80% by mass in the total vinyl monomers constituting the polymer emulsion particles (B).

  The carboxyl group-containing vinyl monomer as the vinyl monomer (b3) is not particularly limited. For example, (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, anhydrous Mention may be made of maleic acid or half esters of dibasic acids such as itaconic acid and maleic acid. By using these carboxylic acid group-containing vinyl monomers, carboxyl groups can be introduced into the polymer emulsion particles (B), and electrostatic repulsion can be provided between the polymer emulsion particles. It is possible to improve the stability as an emulsion and to provide 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 amines such as ammonia, triethylamine and dimethylethanolamine, and bases such as NaOH and KOH. Also good.

  The amount of the carboxyl group-containing vinyl monomer used (when a plurality of carboxyl group-containing vinyl monomers are used, the total amount thereof) is the total vinyl monomers (B) constituting the polymer emulsion particles (B). In (b2) + (b3)), 0 to 50% by mass is preferable from the viewpoint of water resistance. More preferably, it is 0.1-10 mass%, More preferably, it is 0.1-5 mass%.

  The hydroxyl group-containing vinyl monomer as the vinyl monomer (b3) is not particularly limited, and examples thereof include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3- Hydroxyalkyl esters of (meth) acrylic acid such as hydroxypropy (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate; di-2-hydroxy Hydroxyalkyl esters of fumaric acid such as ethyl fumarate and mono-2-hydroxyethyl monobutyl fumarate; (poly) oxyethylene mono (meth) acrylates having 1 to 100 allyl alcohol and ethylene oxide groups; propylene oxide groups 1 to 1 0 (poly) oxypropylene mono (meth) acrylate; Furthermore, “Placcel FM, FA monomer” (trade name of caprolactone addition monomer manufactured by Daicel Chemical Industries) and other α, β-ethylenic properties And hydroxyalkyl esters of unsaturated carboxylic acids.

  When a hydroxyl group-containing vinyl monomer is used as the vinyl monomer (b3), the hydrogen bonding force between the metal oxide (A) and the vinyl monomer (b2) having a secondary and / or tertiary amide group. It becomes easy to control the water dispersion stability of the polymer emulsion particles (B).

  The amount of the hydroxyl group-containing vinyl monomer used is preferably 0 to 80% by mass, more preferably 0.1 to 50% by mass, and more preferably 0.1 to 50% by mass in the total vinyl monomers constituting the polymer emulsion particles (B). Preferably it is 0.1-10 mass%.

  Examples of the epoxy group-containing vinyl monomer as the vinyl monomer (b3) include, but are not limited to, glycidyl group-containing vinyl monomers. Examples of the glycidyl group-containing vinyl monomer include glycidyl (meth) acrylate, allyl glycidyl ether, and allyl dimethyl glycidyl ether.

  Examples of the carbonyl-containing vinyl monomer as the vinyl monomer (b3) include, but are not limited to, diacetone acrylamide.

  When the glycidyl group-containing vinyl monomer or the carbonyl group-containing vinyl monomer is used as the vinyl monomer (b3), the polymer emulsion particles (B) become reactive, and a hydrazine derivative, By crosslinking with a carboxylic acid derivative, an isocyanate derivative, or the like, it is possible to form a coating film having excellent solvent resistance. The amount of the glycidyl group-containing vinyl monomer or the carbonyl group-containing vinyl monomer used is preferably 0 to 50% by mass in the total vinyl monomers constituting the polymer emulsion particles (B).

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 Polyoxypropylene block copolymers, reactive emulsifier having a double bond of nonionic surface active agent and a radical polymerizable polyoxyethylene distyryl phenyl ether, and the like.

  Among these emulsifiers, when a reactive emulsifier having a radical polymerizable double bond is selected, the water dispersion stability of the polymer emulsion particles (B) is further improved, and water resistance, chemical resistance, It is more preferable because a coating film excellent in optical characteristics, strength, and the like can be formed.

  Examples of the reactive emulsifier having a radical polymerizable double bond include, but are not limited to, a vinyl monomer having a sulfonic acid group or a sulfonate group, and a vinyl monomer having a sulfate group. And alkali metal salts or ammonium salts thereof; vinyl monomers having a nonionic group such as polyoxyethylene; vinyl monomers having a quaternary ammonium salt;

  The salt of a vinyl monomer having a sulfonic acid group or a sulfonate group as the reactive emulsifier is not limited to the following. For example, the reactive emulsifier has a radically polymerizable double bond and has a sulfonic acid group. A partially substituted alkyl group having 1 to 20 carbon atoms, an alkyl ether group having 2 to 4 carbon atoms, a polyalkyl ether group having 2 to 4 carbon atoms, or carbon, partially substituted with a group that is an ammonium salt, sodium salt, or potassium salt A compound having a substituent selected from the group consisting of an aryl group of formula 6 or 10 and a succinic acid group; a vinyl sulfonate compound having a vinyl group to which an ammonium salt, sodium salt or potassium salt of a sulfonic acid group is bonded Etc.

  The compound having a succinic acid group partially substituted with a group that is an ammonium salt, sodium salt or potassium salt of the sulfonic acid group is not limited to the following, but examples include allylsulfosuccinate. Can be mentioned. These can also use a commercial item, and it is not specifically limited, For example, Eleminol JS-2 (brand name) (made by Sanyo Kasei Co., Ltd.), Latemuru S-120, S-180A, or S-180 (brand name) (Manufactured by Kao Corporation).

  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, which is partially substituted by a group which is an ammonium salt, sodium salt or potassium salt of a sulfonic acid group, Although not limited to, for example, Aqualon HS-10 or KH-1025 (trade name) (Daiichi Kogyo Seiyaku Co., Ltd.), Adekaria soap SE-1025N or SR-1025 (trade name) (Asahi) Denka Kogyo Co., Ltd.).

  The vinyl monomer having a nonionic group as the reactive emulsifier is not limited to the following, but for example, α- [1-[(allyloxy) methyl] -2- (nonylphenoxy) ethyl]- ω-Hydroxypolyoxyethylene (trade names: Adeka Soap NE-20, NE-30, NE-40, etc., manufactured by Asahi Denka Kogyo Co., Ltd.), polyoxyethylene alkylpropenyl phenyl ether (trade name: Aqualon RN-10) , RN-20, RN-30, RN-50, etc., manufactured by Dai-ichi Pharmaceutical Co., Ltd.).

  The amount of the emulsifier used in the synthesis of the polymer emulsion particles (B) is preferably within a range of 10 parts by mass or less with respect to 100 parts by mass of the polymer emulsion particles (B) to be obtained. A range of 5 parts by mass is more preferable.

  During the synthesis of the polymer emulsion particles (B), the polymerization of the hydrolyzable silicon compound (b1) and the vinyl monomer (b2) having a secondary and / or tertiary amide group is carried out in the presence of a polymerization catalyst. It is preferable.

  The polymerization catalyst for the hydrolyzable silicon compound (b1) can be appropriately selected according to the components of the monomer used for the polymerization, and is not limited to the following. For example, halogenation of hydrochloric acid, hydrofluoric acid, etc. Carboxylic acids such as hydrogen, acetic acid, trichloroacetic 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, polyoxy Acidic emulsifiers such as ethylene alkylarylsulfuric acid and polyoxyethylene distyrylphenyl ether sulfonic acid; acidic or weakly acidic inorganic salts, acidic compounds such as phthalic acid, phosphoric acid and nitric acid; sodium hydroxide, potassium hydroxide, Sodium methylate, sodium acetate, tetramethylammonium chloride Basic such as tetramethylammonium hydroxide, tributylamine, diazabicycloundecene, ethylenediamine, diethylenetriamine, ethanolamines, γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) -aminopropyltrimethoxysilane Compounds: Tin compounds such as dibutyltin octylate and dibutyltin dilaurate are listed. 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.

  As the polymerization catalyst for the vinyl monomer (b2) having a secondary and / or tertiary amide group, a radical polymerization catalyst that causes radical polymerization by heat or a reducing substance to cause addition polymerization of the vinyl monomer is preferable. Although not limited to the following, for example, water-soluble or oil-soluble persulfates, peroxides, azobis compounds and the like are used. Specific examples of the polymerization catalyst are not particularly limited. For example, potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, 2,2-azo Examples thereof include bisisobutyronitrile, 2,2-azobis (2-diaminopropane) hydrochloride, 2,2-azobis (2,4-dimethylvaleronitrile) and the like. As a compounding quantity of the said polymerization catalyst, 0.001-5 mass parts is preferable with respect to 100 mass parts of all the vinyl monomers which comprise a polymer emulsion particle (B). When it is desired to accelerate the polymerization rate and to perform polymerization at a low temperature of 70 ° C. or lower, for example, use a reducing agent such as sodium bisulfite, ferrous chloride, ascorbate, or longalite in combination with the radical polymerization catalyst. Is preferred.

  As described above, the polymer emulsion particles (B) are composed of the hydrolyzable silicon compound (b1) and the vinyl monomer (b2) having a secondary and / or tertiary amide group in the presence of water and an emulsifier. Furthermore, it can be obtained by polymerization using another vinyl monomer (b3) copolymerizable with the vinyl monomer (b2), if necessary, preferably in the presence of a polymerization catalyst. .

  Polymerization of the hydrolyzable silicon compound (b1) and the vinyl monomer (b2) having a secondary and / or tertiary amide group can be carried out separately, but by carrying out at the same time, It is preferable because a micro organic / inorganic composite can be achieved by hydrogen bonding between the two.

  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 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. Moreover, from the viewpoint of improving the transparency of the obtained coating film, the number average particle diameter of the polymer emulsion particles (B) is more preferably 5 to 100 nm. More preferably, it is 40-90 nm.

  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) Examples thereof include a method of synthesizing the polymer emulsion particles (B) by so-called emulsion polymerization in which b1) and a vinyl monomer (b2) having a secondary and / or tertiary amide group are polymerized.

  The emulsion polymerization method of the polymer emulsion particles (B) is not particularly limited. For example, the hydrolyzable silicon compound (b1) and the vinyl monomer (b2) having a secondary and / or tertiary amide group, If necessary, another vinyl monomer (b3) copolymerizable with the vinyl monomer (b2) is dropped into the reaction vessel in a batch, divided, or continuously, as it is or in an emulsified state. In the presence of the polymerization catalyst, polymerization is preferably performed at a reaction temperature of about 30 to 150 ° C., preferably from atmospheric pressure to a pressure of 10 MPa if necessary. You may change a pressure and reaction temperature as needed. The ratio of the hydrolyzable silicon compound (b1) and the total amount of vinyl monomers to water is not particularly limited, but the final solid content (the polymer obtained when all of the added monomers are polymerized) (Value calculated based on the total mass (calculated value) of vinyl (co) polymer and hydrolyzable silicon compound (b1)) is 0.1 to 70% by mass, preferably 1 It is preferable to set it in a range of ˜55 mass%.

In carrying out the emulsion polymerization of the polymer emulsion particles (B), a seed polymerization method in which the emulsion particles are preliminarily present and polymerized in order to grow or control the particle diameter of the polymer emulsion particles (B) is performed. You may go. Thereby, polymer emulsion particles having a more uniform particle diameter can be obtained.
The substance used as the seed (nucleus) is not particularly limited, and a known substance can be used, and can be appropriately selected according to reaction conditions and the like.
The polymerization reaction may be allowed to proceed in the range of pH in the system of preferably 1.0 to 10.0, more preferably 1.0 to 6.0. The pH can be adjusted using a disodium phosphate, borax, or a pH buffer such as sodium bicarbonate or ammonia.

  As a method for obtaining the polymer emulsion particles (B), a hydrolyzable silicon compound (b1) and secondary and / or tertiary amide groups in the presence of water, an emulsifier necessary for polymerization, and a solvent as necessary. A method of adding water until the polymerization product becomes an emulsion after polymerizing the vinyl monomer (b2) having the above may be employed.

The polymer emulsion particles (B) preferably have a core / shell layer structure.
Furthermore, the core layer and the shell layer are preferably different in flexibility, and more preferably the shell layer is more flexible than the core layer.
As for the flexibility, a hydrolyzable silicon compound (b1-3) containing 3 or more hydrolyzable functional groups is used as the hydrolyzable silicon compound (b1), and the hydrolyzate containing 3 or more hydrolyzable functional groups. By defining the weight ratio of the functional silicon compound (b1-3) to the total amount of the vinyl monomer (b2) having the secondary and / or tertiary amide group and the total hydrolyzable silicon compound (b1) Can be controlled.

The hydrolyzable silicon compound (b1-3) component containing three or more hydrolyzable functional groups contained in the core layer comprises a total hydrolyzable silicon compound (b1), a secondary and / or tertiary amide group. (B1-3) / ((b1) + (b2)) ≧ 0.20 is preferable as a mass ratio with respect to the total amount with the vinyl monomer (b2) having, more preferably 0.35 or more. Thereby, the improvement effect of coating-film intensity | strength is acquired.
Further, the hydrolyzable silicon compound (b1-3) component containing three or more hydrolyzable functional groups contained in the shell layer is composed of a total hydrolyzable silicon compound (b1), a secondary and / or tertiary amide. 0.01 <(b1-3) / ((b1) + (b2)) <0.20 in terms of a mass ratio with respect to the total amount with the vinyl monomer having a group (b2), more preferably 0.1 <(B1-3) / ((b1) + (b2)) <0.3 is preferable. Thereby, the improvement effect of coating-film intensity | strength is acquired.

As described above, in the optical coating film of the present embodiment, it is preferable that the shell layer of the polymer emulsion particles (B) is more flexible than the core layer. Thereby, a desired optical coating film can be formed efficiently.
Specifically, in the step of forming the optical coating film of the present embodiment, a coating layer containing the metal oxide (A) and the polymer emulsion particles (B) is applied, and a precursor is formed. Thereafter, sintering is performed. That is, after the precursor is formed in the drying step of removing the solvent from the coating composition, a step of forming the void (X) by sintering is performed. In the step of forming the void (X), all or part of the polymer emulsion particles (B) are removed.
At that time, the condensation of the metal oxide (A) layer around the polymer emulsion particles (B) proceeds rapidly, and the entire coating film shrinks. Here, the presence of the core layer and the shell layer having different flexibility of the polymer emulsion particles (B) reduces the shrinkage of the coating film, and forms an optical coating film while suppressing the collapse of the void (X). Will be able to. As a result, while maintaining the gap (X), a dense gap (Y) is efficiently formed around the gap (X), and high antireflection performance and strength can be expressed. The term “periphery” means that the surface is in direct contact with the surface of the void (X) or exists at a distance that allows chemical interaction. Moreover, it is suppressed that the base-material interface which forms the optical coating film of this embodiment simultaneously, and the space | gap (X) in a coating film contact | connect directly. This is considered to suppress the voids (X) from being crushed and coming into contact with the substrate by the polymer emulsion particles (B) relaxing the contraction of the coating film.

Here, the void (X) can be observed with a transmission electron microscope (TEM) or a scanning electron microscope (SEM).
The air gap (X) is entirely or partially filled with an air layer, and its refractive index is very close to 1.
The average gap size of the gap (X) can be obtained from the average value of the major axis (L) and the maximum value (D) of the minor axis perpendicular to the major axis (L).
The average gap size of the gap (X) is preferably (L + D) / 2> 20 nm, and in relation to the coating film thickness (d), it is preferably d> (L + D) / 2.

  The hydrolyzable silicon compound (b1-3) containing three or more hydrolyzable functional groups is not limited to the following, and examples thereof include tetramethoxysilane, tetraethoxysilane, and tetra-n-propoxysilane. Tetraalkoxysilanes such as tetraisopropoxysilane and tetra-n-butoxysilane; methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltri Ethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n- Cutyltrimethoxysilane, vinyltrimethoxysilane, 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-hydroxypropiyl Trimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycid Xylpropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meta ) Acrylicoxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloyloxypropyltri-n-propoxysilane, 3- (meth) acryloyloxypropyl Examples include trialkoxysilanes such as triisopropoxysilane, 3-ureidopropyltrimethoxysilane, 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, etc. Can be blended.

<Hydrolyzable silicon compound (C)>
The optical coating film of this embodiment may further contain a hydrolyzable silicon compound (C) in addition to the metal oxide (A) and the polymer emulsion particles (B) described above.
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 (2), (3), and (4). .
The above-mentioned (b1) hydrolyzable silicon compound is a component constituting the polymer emulsion particles (B), and is incorporated integrally in the component (B), and the hydrolyzable silicon compound (C ) Is added separately from the component (A) and the component (B), and is clearly distinguished from the above-mentioned (b1) hydrolyzable silicon compound.

R ¹ _n SiX _4-n (2)
(In Formula (2), 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 (3)
(In the formula (3), 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 (4)
(In the formula (4), R ³ is .n represents an alkyl group having 1 to 6 carbon atoms is an integer of 2-8.)

<Content ratio of each component>
The coating composition for forming the optical coating film of this embodiment has a mass ratio ((A) :( B)) of the metal oxide (A) and the polymer emulsion particles (B) of 1: 0.05 to It is preferably 1:10, more preferably 1: 0.1 to 1: 5, and even more preferably 1: 0.5 to 1: 3.
The mass ratio ((A) :( C)) of the metal oxide (A) and the hydrolyzable silicon compound (C) is preferably 1: 0.05 to 1: 5 from the viewpoint of strength, The ratio is more preferably 1: 0.1 to 1: 3, and further preferably 1: 0.5 to 1: 2.

  The mass ratio ((A) :( B)) between the metal oxide (A) and the polymer emulsion particles (B) is (A) :( B) = 1 from the viewpoint of weather resistance when a coating film is formed. : It is preferable that it is 0.05 or more. From the viewpoint of transparency, it is preferably 1:10 or less.

The mass ratio ((A) :( C)) of the metal oxide (A) and the hydrolyzable silicon compound (C) is 1: 0.05 or more from the viewpoint of mechanical strength and weather resistance. preferable. In addition, the mass ratio ((A) :( C)) of the metal oxide (A) and the hydrolyzable silicon compound (C) increases the porosity and makes the coating film have a low refractive index. 5 or less is preferable. The mass of the hydrolyzable silicon compound (C) is the mass in terms of SiO ₂ after the hydrolyzable silicon compound (C) is hydrolyzed and condensed.

The optical coating film of this embodiment preferably contains the hydrolysis condensate (C ′) of the hydrolyzable silicon compound (C) described above, and the hydrolysis condensate (C ′) of the hydrolyzable silicon compound (C). ) Are bound to the surface of the polymer particles (B ′) of the polymer emulsion particles, and the non-spherical metal oxide (a2) is directly on the surface of the polymer particles (B ′) of the polymer emulsion particles, or It is preferable to have a structure in which a void (X) is formed from a precursor bonded through a spherical metal oxide (a1).
Alternatively, a structure in which the non-spherical metal oxide (a2) is bonded to the surface of the polymer particles (B ′) of the polymer emulsion particles directly or via the spherical metal oxide (a1) is added to the hydrolyzate. A void (X) is formed through the precursor coated with the hydrolytic condensate (C ′) of the decomposable silicon compound (C) and fixed to the polymer particles (B ′) of the polymer emulsion particles. It is preferable. The optical coating film having such a structure exhibits excellent mechanical strength and weather resistance as an antireflection film.

[Method for producing optical coating film]
The optical coating film of this embodiment is prepared by preparing a coating composition containing a metal oxide (A), polymer emulsion particles (B), and, if necessary, a hydrolyzable silicon compound (C). It can be manufactured by applying and drying an object to form a precursor and sintering the precursor at a temperature of 500 ° C. or higher.

<Preparation of coating composition>
The coating composition contains a metal oxide (A), preferably a spherical metal oxide (a1), and a non-spherical metal oxide (a2) having an aspect ratio (major axis / minor axis) of 3 to 25 It is preferable to prepare by the 1st process of mix | blending an oxide (A) and polymer emulsion particle | grains (B), and obtaining a mixture, and the 2nd process of adding an acid to the said mixture.
In the case of adding an acid as a hydrolysis catalyst or a condensation catalyst as the “acid”, from the viewpoint of blending stability, the metal oxide (A) and the polymer emulsion particles (B) are blended first, and then the acid. Is preferably added. Or after making it aggregate by adding an acid to the isoelectric point of a metal oxide (A), after neutralizing and stabilizing with a base, you may add a polymer emulsion particle (B).

  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 Examples include weakly acidic inorganic salts, acidic compounds such as phthalic acid, phosphoric acid, and nitric acid.

As solid content of the said coating composition, 0.1 mass%-15 mass% are preferable, More preferably, 0.2 mass%-5 mass%, More preferably, 0.5 mass%-3 mass% are preferable.
It is preferable that the solid content is 15% by mass or less because it becomes easy to control the film thickness after drying to a desired film thickness. Further, it is preferable that the solid content is 0.1% by mass or more because it is not necessary to apply a thick coating composition in order to obtain a desired dry film thickness, and the film thickness can be easily controlled.
The viscosity of the coating composition is preferably 0.1 to 2000 mPa · s at 20 ° C., preferably 1 to 100 mPa · s, and more preferably 2 to 10 mPa · s.

  In the optical coating film of this embodiment, the coating composition described above is applied to a substrate and dried, and then part or all of the polymer emulsion particles (B) are removed to form voids (X). Is obtained. The step of forming this void (X) will be described later.

<The process of apply | coating a coating composition>
The coating composition prepared as described above is applied onto a predetermined material (described as a substrate).
The method for applying the above-described coating composition to the substrate is not particularly limited. For example, spraying, flow coating, roll coating, brush coating, dip coating, spin coating, screen printing, Examples thereof include a casting method, a gravure printing method, a flexographic printing method, and the like. From the viewpoint of productivity, roll coating, screen printing, and gravure printing are preferred. Furthermore, the roll coating method is preferable for the purpose of coating on a large-sized substrate.

As a film thickness which apply | coats the above-mentioned coating composition to a base material, 100 micrometers or less are preferable, More preferably, it is 50 micrometers or less, More preferably, 15 micrometers or less are preferable.
If the thickness exceeds 100 μm, a uniform coating film cannot be obtained, and a partially thick film is formed.

<Step of drying>
After coating the coating composition on the substrate as described above, the coating composition is dried to form a precursor of the optical coating film.
The drying method is not particularly limited, and examples thereof include natural drying, cold air drying, hot air drying, and infrared drying.
The drying temperature is preferably 5 to 700 ° C, more preferably 10 to 300 ° C, still more preferably 20 to 200 ° C, and most preferably 25 to 80 ° C.

<Sintering process>
Furthermore, the precursor of the optical coating film is sintered at a temperature of 500 ° C. or higher as a void forming step.
Preferably, sintering is performed by performing heat treatment at 600 ° C. to 800 ° C., more preferably 600 ° C. to 700 ° C., more preferably 600 ° C. to 650 ° C., ultraviolet irradiation such as a high-pressure mercury lamp, and the like in the coating film. It is possible to form voids.

  The optical coating film of this embodiment preferably has a thickness of 0.05 to 10 μm in terms of transparency and antireflection properties.

  The substrate on which the above-described coating composition for forming the optical coating film of the present embodiment is applied can be appropriately selected depending on the application, and is not particularly limited. For example, synthetic resins, natural resins, etc. Organic base materials, inorganic base materials such as glass, and combinations thereof.

  The optical coating film of this embodiment is a coating film formed on a substrate from the viewpoint of weather resistance, and is a hydrolysis condensate of a metal oxide (A) and / or a hydrolyzable silicon compound (C). (C ′) is preferably directly bonded to the substrate.

The optical coating film of this embodiment preferably has a surface water contact angle of 120 ° or less, more preferably 40 ° or less, and still more preferably 20 ° or less from the viewpoint of antifouling properties.
When the surface water contact angle of the antireflection film is, for example, 40 ° C. or less, there is an effect of preventing hydrophilic dirt, and when it is 40 ° C. or more, there is an effect that lipophilic dirt is easily wiped off.
In the present embodiment, the surface water contact angle can be measured by the method described in Examples described later.

(Use)
Since the optical coating film of the present embodiment is excellent in transparency and antireflection properties, solar cell members (glass, modules, etc.), solar cell condensing lenses, photovoltaic cells, liquid crystal displays, glasses, window glass In televisions and the like, it can be used as an antireflection film for members that require improved light transmission and / or prevention of reflection.

  Hereinafter, the present invention will be described with reference to specific examples and comparative examples, but the present invention is not limited thereto.

Various physical properties in Synthesis Examples, Examples, and Comparative Examples described later were measured by the following methods.
((1) Measurement of average particle diameter (nm))
The metal oxide (A) was magnified 50,000 to 100,000 times, and adjusted so that 100 to 200 spherical metal oxide (A) particles appeared, and a transmission micrograph was taken.
Next, the particle diameter (major axis and minor axis) of each photographed metal oxide (A) was measured, and an average value thereof ((major axis + minor axis) / 2) was obtained and used as an average particle diameter.

((2) Measurement of total light transmittance (%))
About the test plate manufactured by the Example and comparative example which are mentioned later, total light transmittance was measured by the method prescribed | regulated to JISK7361-1 using Nippon Denshoku Industries Co., Ltd. turbidimeter NDH2000.

((3) Measurement of pencil hardness)
A test pencil specified by JIS S6006 is manufactured from optical coating films manufactured in Examples and Comparative Examples described later, and 1 kg load is applied according to the pencil hardness evaluation method specified in JIS K5400 using the test pencil. The pencil hardness was evaluated.

((4) Measurement of surface water contact angle (°))
A drop of deionized water (1.0 μL) was placed on the surface of the optical coating film produced in Examples and Comparative Examples described later, and left at 20 ° C. for 10 seconds. Thereafter, the initial contact angle was measured using a CA-X150 contact angle meter manufactured by Kyowa Interface Science, Japan. The smaller the contact angle of water with the optical coating film, the higher the hydrophilicity of the coating surface.

((5) Weather resistance test)
For the test plates produced in the examples and comparative examples described later, a weathering test is allowed to stand for 4 hours in an environment of 135 ° C. and 85% humidity using an accelerated environment tester (EHS-411, manufactured by Espec Corp.). Went. In addition, the total light transmittance of the test plate after the weather resistance test was measured according to the method described in the above (2).

((6) Measurement of average void size of void (X) (Y))
The volume of voids was measured by a nitrogen adsorption method using “Canthochrome Autosorb-1” to determine the average void size. In addition, about the pore whose pore diameter is 18 nm or less, the volume of the space | gap was measured by BJH method and the average space | gap size was calculated | required.

((7) Number average particle diameter of polymer emulsion particles)
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 analyzer (trade name: Microtrac UPA, manufactured by Nikkiso Co., Ltd.).

((8) AR value, AR change rate)
Using the total light transmittance before and after the weather resistance test and the total light transmittance of the base material of the test plates manufactured according to Examples and Comparative Examples described later, the AR value, AR by the following formulas (6) and (7) The rate of change was calculated.

When the AR is 2% or more, it can be evaluated that the antireflection characteristic is good.
When the absolute value of the AR change rate is 50% or less, it can be evaluated that the weather resistance is good.

((9) Contact between substrate interface and void (X))
As a result of observing the coating film cross section with TEM (Hitachi S550, pressurization voltage 30 kV) for the optical coating film test plates obtained in Examples and Comparative Examples described later, the gap (X) is in direct contact with the substrate. Evaluated whether or not.

((10) (b1-3) ratio in the core layer and shell layer of the polymer emulsion particles (B))
Vinyl monomer (b2) and total hydrolyzability of hydrolyzable silicon compound (b1-3) containing three or more hydrolyzable functional groups in the core layer and shell layer of polymer emulsion particles (B) The mass ratio ((b1-3) / ((b1) + (b2)) to the total amount with the silicon compound (b1) was calculated.

(Synthesis example)
Hereinafter, synthesis examples of the polymer emulsion particles (B) used in Examples and Comparative Examples described later are described.
(Synthesis Example 1)
<Synthesis of Polymer Emulsion Particle (B-1) Water Dispersion>
A reactor having a reflux condenser, a dropping tank, a thermometer, and a stirring device was charged with 1600 g of ion-exchanged water and 7 g of dodecylbenzenesulfonic acid, and then heated to 80 ° C. with stirring to prepare the mixed liquid (1). Obtained.
To the obtained mixed liquid (1), a mixed liquid (2) of 185 g of dimethyldimethoxysilane and 117 g of phenyltrimethoxysilane (b1-3) as a core layer was added while maintaining the temperature in the reaction vessel at 80 ° C. It was dripped over 2 hours 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-methacryloxypropyltrimethoxy as a shell layer were added to the obtained mixed liquid (3). Silane (b1-3) 1.3 g mixed solution (4), diethylacrylamide 165 g, acrylic acid 3 g, reactive emulsifier (trade name “Adekaria Soap SR-1025”, manufactured by Asahi Denka Co., Ltd., solid content 25 (5% by weight aqueous solution) 13 g, a mixed solution (5) of 2% by weight aqueous ammonium persulfate 40 g, and 1900 g of ion-exchanged water were added dropwise simultaneously over a period of about 2 hours while maintaining the temperature in the reaction vessel at 80 ° C. Thus, a mixture (6) was obtained.
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 Particle (B-2) Water Dispersion>
A reactor having a reflux condenser, a dropping tank, a thermometer, and a stirring device was charged with 1600 g of ion-exchanged water and 12 g of dodecylbenzenesulfonic acid, and then heated to 80 ° C. with stirring to prepare the mixed liquid (1). Obtained.
To the obtained mixture (1), a mixture (2) of 185 g of dimethyldimethoxysilane and 151 g of phenyltrimethoxysilane (b1-3) as a core layer was added in a state where the temperature in the reaction vessel was kept at 80 ° C. It was dripped over 2 hours 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-methacryloxypropyltrimethoxy as a shell layer were added to the obtained mixed liquid (3). Silane (b1-3) 1.3 g mixed solution (4), diethylacrylamide 165 g, acrylic acid 3 g, reactive emulsifier (trade name “Adekaria Soap SR-1025”, manufactured by Asahi Denka Co., Ltd., solid content 25 (5% by weight aqueous solution) 13 g, a mixed solution (5) of 2% by weight aqueous ammonium persulfate 40 g, and 1900 g of ion-exchanged water were added dropwise simultaneously over a period of about 2 hours while maintaining the temperature in the reaction vessel at 80 ° C. Thus, a mixture (6) was obtained.
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 40 nm. 10% by mass, pH 3.2) was obtained.

(Synthesis Example 3)
<Synthesis of Polymer Emulsion Particle (B-3) Water Dispersion>
A reactor having a reflux condenser, a dropping tank, a thermometer, and a stirring device was charged with 1600 g of ion-exchanged water and 12 g of dodecylbenzenesulfonic acid, and then heated to 80 ° C. with stirring to prepare the mixed liquid (1). Obtained.
To the obtained mixed liquid (1), a mixed liquid (2) of 185 g of dimethyldimethoxysilane and 117 g of phenyltrimethoxysilane (b1-3) as a core layer was added while maintaining the temperature in the reaction vessel at 80 ° C. It was dripped over 2 hours 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-methacryloxypropyltrimethoxy as a shell layer were added to the obtained mixed liquid (3). Silane (b1-3) 1.3 g mixed solution (4), diethylacrylamide 165 g, acrylic acid 3 g, reactive emulsifier (trade name “Adekaria Soap SR-1025”, manufactured by Asahi Denka Co., Ltd., solid content 25 (5% by weight aqueous solution) 13 g, a mixed solution (5) of 2% by weight aqueous ammonium persulfate 40 g, and 1900 g of ion-exchanged water were added dropwise simultaneously over a period of about 2 hours while maintaining the temperature in the reaction vessel at 80 ° C. Thus, a mixture (6) was obtained.
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 Particle (B-4) Water Dispersion>
A reactor having a reflux condenser, a dropping tank, a thermometer, and a stirring device was charged with 1600 g of ion-exchanged water and 12 g of dodecylbenzenesulfonic acid, and then heated to 80 ° C. with stirring to prepare the mixed liquid (1). Obtained.
To the obtained mixed liquid (1), a mixed liquid (2) of 185 g of dimethyldimethoxysilane and 72 g of phenyltrimethoxysilane (b1-3) as a core layer was added in a state where the temperature in the reaction vessel was kept at 80 ° C. It was dripped over 2 hours 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-methacryloxypropyltrimethoxy were added as a shell layer to the obtained mixed liquid (3). Silane (b1-3) 1.3 g mixed solution (4), diethylacrylamide 165 g, acrylic acid 3 g, reactive emulsifier (trade name “Adekaria Soap SR-1025”, manufactured by Asahi Denka Co., Ltd., solid content 25 (5% by weight aqueous solution) 13 g, a mixed solution (5) of 2% by weight aqueous ammonium persulfate 40 g, and 1900 g of ion-exchanged water were added dropwise simultaneously over a period of about 2 hours while maintaining the temperature in the reaction vessel at 80 ° C. Thus, a mixture (6) was obtained.
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 42 nm. 10% by mass, pH 3.2) was obtained.

(Synthesis Example 5)
<Synthesis of Polymer Emulsion Particle (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, 12 g of dodecylbenzenesulfonic acid, 25% aqueous solution of polyoxyethylene nonylphenyl ether (Emulgen 950, manufactured by Kao Corporation) After adding 20 parts, the mixture was heated to 80 ° C. with stirring to obtain a mixed solution (1).
In the resulting mixture (1), 18 g of methacrylic acid, 216 g of methyl methacrylate, 216 g of butyl acrylate, 6.9 g of 3-methacryloxypropyltrimethoxysilane (b1-3), and 101 g of methyltrimethoxysilane were used as the core layer. Then, a mixed solution (2) of 2% by weight aqueous solution of ammonium persulfate (40 g) was dropped over about 2 hours while keeping the temperature in the reaction vessel at 80 ° C. to obtain a mixed solution (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, a reactive emulsifier (trade name “Adekaria Soap SR-1025”, Asahi Denka Co., Ltd.) was added to the resulting mixture (3) as a shell layer. Manufactured solution, solid content 25 mass% aqueous solution) 13 g, ammonium persulfate 2 mass% aqueous solution 40 g and ion-exchanged water 1900 g mixed liquid (4) for about 2 hours with the temperature in the reaction vessel maintained at 80 ° C. The mixture (5) was obtained by dripping simultaneously.
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, pH 3.2) was obtained.

[Synthesis Example 6]
-Synthesis of polymer emulsion particle (B-6) aqueous dispersion In a reactor having a reflux condenser, a dropping tank, a thermometer and a stirrer, 2600 g of ion-exchanged water, 12 g of dodecylbenzenesulfonic acid, polyoxyethylene nonylphenyl After adding 20 parts of a 25% aqueous solution of 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) of 18 g of methacrylic acid, 216 g of methyl methacrylate, 216 g of butyl acrylate, and 40 g of a 2 mass% aqueous solution of ammonium persulfate as a core layer was added to the obtained mixed liquid (1) at a temperature of 80 in the reaction vessel. The mixture (3) was obtained by dropwise addition over about 2 hours while maintaining the temperature.
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), methyltril as a shell layer were added to the obtained mixed liquid (3). 101 g of methoxysilane, 13 g of reactive emulsifier (trade name “Adekaria Soap SR-1025”, manufactured by Asahi Denka Co., Ltd., solid content 25% by mass aqueous solution), 40 g of 2% by mass aqueous solution of ammonium persulfate, and 1900 g of ion-exchanged water The mixture (4) was added dropwise simultaneously 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 particle (B-7) 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, polyoxyethylene nonylphenyl After adding 20 parts of a 25% aqueous solution of 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) of 18 g of methacrylic acid, 216 g of methyl methacrylate, 216 g of butyl acrylate, and 40 g of a 2 mass% aqueous solution of ammonium persulfate as a core layer was added to the obtained mixed liquid (1) at a temperature of 80 in the reaction vessel. The mixture (3) was obtained by dropwise addition over about 2 hours while maintaining the temperature.
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, reactive emulsifier (trade name “ADEKA rear soap SR-1025” were added to the obtained mixed liquid (3) as a shell layer. , Manufactured by Asahi Denka Co., Ltd., 25 g solid solution (solid content 25 wt%), a mixed solution (4) of 2 wt% ammonium persulfate aqueous solution 40 g, and 1900 g ion-exchanged water, the temperature in the reaction vessel is kept at 80 ° C. The mixture (5) was obtained by dripping simultaneously over about 2 hours.
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-7) having a number average particle diameter of 140 nm.

[Example 1]
An aqueous dispersion of the polymer emulsion particles (B-1) synthesized in Synthesis Example 1 was used as the polymer emulsion particles (B). Water-dispersed colloidal silica having an average particle size of 5 nm (trade name “Snowtex OXS (described as“ ST-OXS ”in Table 1)”) as a raw material for the spherical metal oxide (A), manufactured by Nissan Chemical Industries, Ltd. , Solid content of 10% by mass).
Tetraethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the hydrolyzable silicon compound (C).
These were mixed at a solid content mass ratio shown in Table 1, adjusted with 20% ethanol water so as to have a solid content of 2%, and then stirred to obtain a coating composition (E-1).

The coating composition (E-1) was applied to a substrate (5 cm × 5 cm white glass) using a spin coater so as to have a film thickness of 100 nm, then dried at 25 ° C. for 60 minutes, and further in an electric furnace After being sintered at 600 ° C. for 3 minutes, it was quenched and a test plate (G-1) having a coating film (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 ′) = 300 / It became 100/45.
In addition, (B ′) is a polymer particle derived from the polymer emulsion particles (B) obtained after the sintering, and (C ′) is a hydrolyzable silicon compound (C) obtained after the sintering. The hydrolysis condensate of

[Example 2]
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 ′) = 150/100 / It was set to 15. 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 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 test plate (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 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 test plate (G-4) are shown in Table 1.

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

Example 6
Instead of tetraethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), methyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) was used. Other conditions were the same as in Example 1 to obtain a test plate (G-6). The evaluation results of the obtained test plate (G-6) are shown in Table 1.

Example 7
The mass ratio of each component was adjusted to (A) / (B ′) / (C ′) = 200/100/100. 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.

Example 8
An aqueous dispersion of the polymer emulsion particles (B-4) synthesized in Synthesis Example 4 was used as the polymer emulsion particles (B). Other conditions were the same as in Example 1 to obtain a test plate (G-8). The evaluation result of the obtained test plate (G-8) is shown in Table 1.

Example 9
The mass ratio of each component was adjusted to (A) / (B ′) / (C ′) = 300/100/0. Other conditions were the same as in Example 8, and a test plate (G-9) was obtained. The evaluation results of the obtained test plate (G-9) are shown in Table 1.

[Comparative Example 1]
An aqueous dispersion of the polymer emulsion particles (B-5) synthesized in Synthesis Example 5 was used as the polymer emulsion particles (B). Other conditions were the same as in Example 1 to obtain a test plate (G-11). Table 1 shows the evaluation results of the obtained test plate (G-11).

[Comparative Example 2]
An aqueous dispersion of the polymer emulsion particles (B-6) synthesized in Synthesis Example 6 as the polymer emulsion particles (B), and an aqueous dispersion colloidal silica having an average particle diameter of 4 nm as a raw material for the spherical metal oxide (A) (product) The name “NALCO1115” (manufactured by Nalco Company, solid content: 16.5% by mass) was mixed at a solid content mass ratio shown in Table 1 and adjusted with 20% ethanol water to a solid content of 2%, followed by stirring. A coating composition (E-10) was obtained.
The coating composition (E-10) was applied to a base material (5 cm × 5 cm white glass) using a spin coater so as to have a film thickness of 100 nm, and then dried at 25 ° C. for 60 minutes. Then, after sintering at 600 ° C. for 3 minutes, the test plate (G-12) having the coating film (F-10) was obtained after quenching. At this time, the composition ratio in the coating film (F-10) (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). The evaluation results of the obtained test plate (G-12) are shown in Table 1.

[Comparative Example 3]
Polymer emulsion particles (B-7) as polymer emulsion particles (B) (acrylic emulsion, solid content 32%, pH 7.7, viscosity 150 mPa · s, acid value 39, glass transition temperature 74 ° C., minimum film formation temperature − 10 ° C.), water-dispersed colloidal silica having an average particle diameter of 4 nm (trade name “NALCO1115”, manufactured by Nalco Company, solid content of 16.5% by mass) as a raw material for the spherical metal oxide (A), Mixed at a partial mass ratio. Thereafter, the pH was adjusted to 2.5 with a 0.1N hydrochloric acid aqueous solution, and further adjusted with 20% ethanol water so that the solid content was 2% to obtain a coating composition (E-11).
The coating composition (E-11) was applied to a substrate (5 cm × 5 cm white glass) using a spin coater so as to have a film thickness of 100 nm, then dried at 25 ° C. for 60 minutes, and further in an electric furnace After being sintered at 600 ° C. for 3 minutes, it was quenched and a test plate (G-13) having a coating film (F-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 ′) = 90 / It became 10/0.
Other conditions were the same as in Example 1 to obtain a test plate (G-13). The evaluation results of the obtained test plate (G-13) are shown in Table 1.

The evaluation results of Examples 1 to 9 and Comparative Examples 1 to 3 described above are shown in Table 1 below.
In Table 1, the rightmost column shows the total light transmittance and water contact angle data of only the base materials (5 cm × 5 cm white plate glass) used in Examples 1 to 9 and Comparative Examples 1 to 3. .

As shown in Table 1, in Examples 1 to 9, even after the weather resistance test, the total light transmittance is high, has an excellent antireflection effect, and has a practically sufficient mechanical strength. I found out.
On the other hand, in Comparative Examples 1 to 3, it was confirmed that the total reflection transmittance was lowered after the weather resistance test, and the antireflection characteristics were lowered.

  The optical coating film of the present invention is an antireflection film of a member that needs to improve light transmission and / or prevent reflection, such as a solar cell, a photovoltaic cell, a liquid crystal display, glasses, a window glass, a television, and the like. It has industrial applicability as an antifouling coating for members.

Claims (10)

An optical coating consisting of a coating formed on a substrate,
In the coating film, the average value of the major axis (L) and the maximum value of the minor axis perpendicular to it (D): ((L + D) / 2) has a gap (X) of 20 nm or more,
The major axis (L) and minor axis (D) of the void (X) are 1 <L / D,
An optical coating film in which the gap (X) is not in contact with the base material at the interface with the base material.   The optical coating film according to claim 1, further comprising voids (Y) having an average void size of less than 20 nm around the voids (X).   The optical coating film is formed by applying a coating composition containing a metal oxide (A) and polymer emulsion particles (B) and drying the precursor of the optical coating film at a temperature of 600 ° C. or higher. The optical coating film according to claim 1, wherein the optical coating film is formed by bonding. The polymer emulsion particles (B) are particles having a core / shell layer structure,
The polymer emulsion particles (B) include a hydrolyzable silicon compound (b1) and a vinyl monomer (b2) having a secondary and / or tertiary amide group as a polymer monomer,
The ratio of the hydrolyzable silicon compound (b1-3) containing 3 or more hydrolyzable functional groups in the core layer is such that the vinyl monomer (b2) having the secondary and / or tertiary amide group In a mass ratio to the total amount with the hydrolyzable silicon compound (b1),
The optical coating film according to claim 1, wherein (b1-3) / ((b1) + (b2)) ≧ 0.20. The polymer emulsion particles (B) are particles having a core / shell layer structure,
The polymer emulsion particles (B) include a hydrolyzable silicon compound (b1) and a vinyl monomer (b2) having a secondary and / or tertiary amide group as a polymerization monomer,
The ratio of the hydrolyzable silicon compound (b1-3) containing three or more hydrolyzable functional groups in the shell layer is such that the vinyl monomer (b2) having the secondary and / or tertiary amide group has In a mass ratio to the total amount with the hydrolyzable silicon compound (b1),
0.01 <(b1-3) / ((b1) + (b2)) <0.20
The optical coating film according to any one of claims 1 to 4, wherein Applying a coating composition comprising a metal oxide (A) and polymer emulsion particles (B) and drying to form a precursor of an optical coating;
Sintering the precursor at a temperature of 500 ° C. or higher to form an optical coating;
A method for producing an optical coating film comprising:   The optical coating film according to any one of claims 1 to 5, wherein the optical coating film is an antireflection film.   A glass for solar cell comprising the antireflection film according to claim 7.   A solar cell module comprising the antireflection film according to claim 7.   The condensing lens for solar cells containing the anti-reflective film of Claim 7.