JP2015158537A - Anti-glare filmed article, manufacturing method therefor, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anti-glare filmed article that offers a higher anti-glare effect than conventional products; a manufacturing method that enables manufacturing of an article having an anti-glare film that offers a high anti-glare effect and abrasion resistance and is less susceptible to cracks and coloring; and an image display device with good visibility.SOLUTION: An anti-glare filmed article 10 comprises a base material 12 having an anti-glare film 14 formed thereon, where the article has a haze of no less than 15% and the anti-glare film 14 has a surface with a specular gloss of no greater than 25% at 60° and an arithmetic mean roughness Ra of no less than 0.17 μm. A manufacturing method for the anti-glare filmed article 10 involves; coating the base material 12 with a coating liquid containing a matrix precursor (A), inorganic particles (B), and a liquid medium (C) to form a coated film; bringing the coated film in contact with an alkaline water solution having pH of 10-12.5; and then baking the coated film to form the anti-glare film 14.

Description

  The present invention relates to an article with an antiglare film, a method for producing the same, and an image display device including the article with an antiglare film.

In image display devices (liquid crystal displays, organic EL displays, plasma displays, etc.) provided in various devices (TVs, personal computers, smartphones, mobile phones, etc.), room lights (fluorescent lamps, etc.), external light such as sunlight Is reflected on the display surface, the visibility decreases due to the reflected image.
As a method for suppressing the reflection of external light, there is a method in which an antiglare film having irregularities on its surface is disposed on the display surface of the image display device, and diffused reflection of external light makes the reflected image unclear.

  As a method for forming an antiglare film, a method is known in which a coating solution containing a matrix precursor such as an alkoxysilane hydrolysis condensate is applied to a substrate to form a coating film, and the coating film is baked ( Patent Documents 1 and 2). At this time, in order to form a coating film in a short time, a catalyst for promoting hydrolysis and condensation of the matrix precursor is added to the coating solution. Examples of the catalyst include an acid catalyst and an alkali catalyst. When an alkali catalyst is added, the hydrolysis and condensation of the matrix precursor proceeds too quickly, so that the coating solution gels and it becomes difficult to apply the coating solution. Therefore, as the catalyst, an acid catalyst in which hydrolysis and condensation of the matrix precursor proceeds slowly is used.

  By the way, in order to increase the antiglare effect of the antiglare film, it is necessary to increase the surface roughness (roughen the surface). In order to roughen the surface of the antiglare film, the coating liquid may be applied repeatedly to increase the film thickness of the antiglare film. However, when the coating film is baked after the coating liquid is applied repeatedly to increase the thickness of the coating film, cracks occur in the antiglare film formed by the baking. Moreover, when the coating film with a thick film thickness is baked at a high temperature in order to improve the wear resistance of the antiglare film, coloring occurs in the antiglare film formed by baking.

JP-A-60-109134 JP 2009-058640 A

  INDUSTRIAL APPLICABILITY The present invention provides a method for producing an article having an antiglare film having a higher antiglare effect than conventional ones, a method for producing an article having an antiglare film having high antiglare effect and wear resistance, and suppressed cracking and coloring, and visual recognition Provided is an image display device with good performance.

  The article with an antiglare film of the present invention is an article having an antiglare film on the surface of a substrate, the haze of the article is 15% or more, and the 60 ° specular gloss on the surface of the antiglare film is 25% or less, and the arithmetic average roughness Ra of the surface of the antiglare film is 0.17 μm or more.

The method for producing an article with an antiglare film according to the present invention is a method for producing an article having the antiglare film according to the present invention, and includes the following steps (i) to (iii).
(I) The process of apply | coating the coating liquid containing a matrix precursor (A), an inorganic particle (B), and a liquid medium (C) to a base material, and forming a coating film.
(Ii) A step of bringing the coating film into contact with an alkaline aqueous solution having a pH of 10 to 12.5 after the step (i).
(Iii) The process of baking the said coating film and forming an anti-glare film after the said process (ii).

The coating solution preferably further contains an acid catalyst (D).
The aqueous alkaline solution is preferably electrolytic reduced water.
The firing temperature in the step (iii) is preferably 200 to 480 ° C.
The substrate may be aluminosilicate glass.
The substrate may be a glass having a curved surface.

  The image display device of the present invention includes an image display device main body for displaying an image, and an article with an antiglare film of the present invention provided on the viewing side of the image display device main body or the anti-glare obtained by the manufacturing method of the present invention. And an article with a glare film.

The article with an antiglare film of the present invention has a higher antiglare effect than conventional ones.
According to the method for producing an article with an antiglare film of the present invention, an article having an antiglare film with high antiglare effect and wear resistance, and with suppressed cracking and coloring can be produced.
The image display device of the present invention has good visibility.

It is a cross-sectional schematic diagram which shows an example of the articles | goods with an anti-glare film of this invention.

The following definitions of terms apply throughout this specification and the claims.
The “matrix precursor” means a substance that can form a matrix of an antiglare film by firing.
The “silica precursor” means a substance that can form a matrix mainly composed of silica by firing.
“Containing silica as a main component” means containing 90 mass% or more of SiO ₂ .
The “hydrolyzable group bonded to a silicon atom” means a group that can be converted into an OH group bonded to a silicon atom by hydrolysis.
“Scaly particle” means a particle having a flat shape. The shape of the particles can be confirmed using a transmission electron microscope (hereinafter also referred to as TEM).
"Electrolytically reduced water" is generated on the cathode side when water containing electrolyte (tap water, electrolyte-added water, etc.) is electrolyzed by known electrolysis methods (ion exchange method, diaphragm method, mercury method, etc.) It means the liquid to be used.
The “60 ° specular gloss” is an anti-glare effect in which black tape is attached to the surface opposite to the side on which the anti-glare film is formed by the method described in JIS Z 8741: 1997 (ISO 2813: 1994). Measured for filmed articles.
“Haze” is measured by the method described in JIS K 7136: 2000 (ISO 14782: 1999).
The “arithmetic average roughness Ra” is measured by the method described in JIS B 0601: 2001 (ISO 4287: 1997).
The “average particle diameter” means the particle diameter at a point where the cumulative volume distribution curve is 50% in the cumulative volume distribution curve with the total volume distribution determined on the basis of volume being 100%, that is, the volume-based cumulative 50% diameter (D ₅₀ ). . The particle size distribution is obtained from a frequency distribution and a cumulative volume distribution curve measured with a laser diffraction / scattering particle size distribution measuring apparatus.
“Aspect ratio” means the ratio of the longest length to the thickness of the particles (longest length / thickness), and “average aspect ratio” is the average of the aspect ratios of 50 randomly selected particles Value. The thickness of the particles is measured by an atomic force microscope (hereinafter also referred to as AFM), and the longest length is measured by TEM.
The “pH of the alkaline aqueous solution” is measured at 23 ± 2 ° C. using a commercially available pH meter (for example, D-22, electrode type 9615, manufactured by Horiba, Ltd.).

<Article with antiglare film>
The article with an antiglare film of the present invention (hereinafter also simply referred to as an article with an antiglare film) has an antiglare film on the surface of a substrate.
FIG. 1 is a schematic cross-sectional view showing an example of an article with an antiglare film of the present invention. The article 10 with an antiglare film has a base material 12 and an antiglare film 14 formed on the surface of the base material 12.

  Examples of the article with an antiglare film include a protective plate and various filters provided on the viewing side of the image display device main body, a protective plate for a solar cell module, and the like.

  The haze of the article with an antiglare film is 15% or more, preferably 15 to 45%, more preferably 18 to 35%, and still more preferably 20 to 30%. When the haze is 15% or more, the antiglare effect is sufficiently exhibited. If the haze is 45% or less, a decrease in contrast of the image can be sufficiently suppressed.

(Base material)
Examples of the material for the substrate include transparent materials such as glass and resin, and glass is preferable from the viewpoint of heat resistance during firing in the step (iii) described later.
Examples of the glass include soda lime glass, borosilicate glass, aluminosilicate glass, and alkali-free glass. Aluminosilicate glass is preferred because large stress is easily applied by the tempering treatment even if the thickness is small, and is suitable as an article placed on the viewing side of the image display device. For the same reason, chemically strengthened glass is preferable, and chemically strengthened aluminosilicate glass is particularly preferable.
Examples of the resin include polyethylene terephthalate, polycarbonate, triacetyl cellulose, polymethyl methacrylate, and the like.

Examples of the form of the substrate include a plate and a film.
The shape of the substrate is usually a flat shape. Recently, in various devices (TVs, personal computers, smartphones, car navigation systems, etc.), the display surface of the image display device has been curved, and the curved surface is curved in accordance with the shape of the image display device. The shape which has this may be sufficient.

The substrate may have a functional layer on the surface of the substrate body.
Examples of the functional layer include an undercoat layer, an adhesion improving layer, and a protective layer.
The undercoat layer functions as an alkali barrier layer or a wide band low refractive index layer. The undercoat layer is preferably a layer formed by applying an undercoat coating composition containing a hydrolyzate of alkoxysilane (sol-gel silica) to the substrate body.

(Anti-glare film)
The antiglare film is, for example, a film in which inorganic particles (B) are present in a matrix formed by firing the matrix precursor (A), and the surface has irregularities.

  The 60 ° specular gloss on the surface of the antiglare film is 25% or less, preferably 0 to 25%, more preferably 0 to 20%, and still more preferably 0 to 15%. The 60 ° specular gloss on the surface of the antiglare film is an index of the antiglare effect. If the 60 ° specular gloss is 25% or less, the antiglare effect is sufficiently exhibited.

  The arithmetic average roughness Ra of the surface of the antiglare film is 0.17 μm or more, preferably 0.17 to 0.35 μm, more preferably 0.20 to 0.33 μm, and further more preferably 0.21 to 0.31 μm. preferable. If the arithmetic average roughness Ra of the surface of the antiglare film is 0.17 μm or more, the antiglare effect is sufficiently exhibited. When the arithmetic average roughness Ra of the surface of the antiglare film is 0.35 μm or less, a decrease in image contrast is sufficiently suppressed.

<Method for producing article with antiglare film>
The method for producing an article with an antiglare film according to the present invention includes the following steps (i) to (iii). If necessary, it may have a step of forming a functional layer on the surface of the substrate body before forming the anti-glare film, and a step of performing known post-processing after forming the anti-glare film. It may be.
(I) The process of apply | coating the coating liquid containing a matrix precursor (A), an inorganic particle (B), and a liquid medium (C) to a base material, and forming a coating film.
(Ii) A step of bringing the coating film into contact with an alkaline aqueous solution having a pH of 10 to 12.5 after the step (i).
(Iii) The process of baking the said coating film and forming an anti-glare film after the said process (ii).

[Step (i)]
When a coating liquid containing the matrix precursor (A), the inorganic particles (B), and the liquid medium (C) is applied to the substrate, the liquid medium (C) volatilizes and the matrix precursor (A) has. A part of the hydrolyzable group is hydrolyzed and condensed to form a coating film. When the coating solution contains an acid catalyst (D), the condensation proceeds linearly and a linear polymer is mainly formed. Therefore, compared with the case where an alkali catalyst is used, gelation is slow and many unreacted hydrolyzable groups remain.

(Coating solution)
The coating solution contains a matrix precursor (A), inorganic particles (B), and a liquid medium (C), and if necessary, an acid catalyst (D) and a known additive (E). Also good. When the matrix precursor (A) is a silica precursor, the coating solution contains a silane compound (A1) having a hydrocarbon group bonded to a silicon atom and a hydrolyzable group and a hydrolysis condensate thereof as the silica precursor. It is preferable to include at least either one or both. Moreover, it is preferable that a coating liquid contains a scaly particle (B1) at least as an inorganic particle (B).

  The ratio of the matrix precursor (A) (as oxide) is 35 to 90 mass in the solid content (100% by mass) in the coating solution (however, the matrix precursor (A) is as oxide). % Is preferable, and 50 to 88% by mass is more preferable. If the ratio of a matrix precursor (A) is 35 mass% or more, sufficient adhesive strength with a base material will be obtained. If the ratio of a matrix precursor (A) is 90 mass% or less, even if the film thickness is thick, the crack of an anti-glare film is fully suppressed.

The ratio of the total of the silane compound (A1) and its hydrolysis condensate (in terms of SiO ₂ ) is the solid content (100% by mass) in the coating solution (however, the silica precursor is in terms of SiO ₂ ). 5-30 mass% is preferable and 7-20 mass% is more preferable. If the total ratio of the silane compound (A1) and its hydrolysis condensate is 5% by mass or more, the cracks in the antiglare film can be sufficiently suppressed even if the film thickness is large. When the total ratio of the silane compound (A1) and its hydrolysis condensate is 30% by mass or less, sufficient wear resistance can be obtained.

  The proportion of the inorganic particles (B) is preferably 5 to 35% by mass in the solid content (100% by mass) in the coating solution (however, the matrix precursor (A) is converted to oxide), and 5 to 35% by mass is preferable. 30 mass% is more preferable. If the proportion of the inorganic particles (B) is 5% by mass or more, the haze of the article with the antiglare film will be sufficiently high, and the 60 ° specular gloss on the surface of the antiglare film will be sufficiently low. The dazzling effect is fully exhibited. If the proportion of the inorganic particles (B) is 35% by mass or less, sufficient wear resistance can be obtained.

  The ratio of the scale-like particles (B1) is preferably 5 to 35% by mass in the solid content (100% by mass) in the coating solution (however, the matrix precursor (A) is converted to oxide). -30 mass% is more preferable. When the ratio of the scale-like particles (B1) is 35% by mass or more, cracks in the antiglare film can be sufficiently suppressed even if the film thickness is large. When the ratio of the scale-like particles (B1) is 35% by mass or less, sufficient wear resistance strength can be obtained.

  1-5 mass% is preferable among coating liquid (100 mass%), and, as for the solid content density | concentration in a coating liquid, 2-4 mass% is more preferable. When the solid content concentration is 1% by mass or more, the amount of the coating solution can be reduced. If solid content concentration is 5 mass% or less, the uniformity of the film thickness of an anti-glare film will improve.

  The coating solution can be prepared, for example, by mixing a solution of the matrix precursor (A) and a dispersion of inorganic particles (B). The acid catalyst (D) is preferably included in the matrix precursor (A) solution in advance.

(Matrix precursor (A))
Examples of the matrix precursor (A) include a silica precursor, an alumina precursor, a zirconia precursor, and a titania precursor. From the viewpoint of easily controlling the reactivity, a silica precursor is preferable.

Examples of the silica precursor include alkoxysilane, a hydrolysis condensate of alkoxysilane (sol-gel silica), silazane and the like. From the viewpoint of each characteristic of the antiglare film, either alkoxysilane or its hydrolysis condensate or Both are preferable, and a hydrolysis condensate of alkoxysilane is more preferable.
Examples of the alumina precursor include aluminum alkoxide, hydrolysis condensate of aluminum alkoxide, water-soluble aluminum salt, aluminum chelate and the like.
Examples of the zirconia precursor include zirconium alkoxide, a hydrolysis condensate of zirconium alkoxide, and the like.
Examples of the titania precursor include titanium alkoxide, hydrolysis condensate of titanium alkoxide, and the like.

  The silica precursor is a silane compound (A1) having a hydrocarbon group bonded to a silicon atom and a hydrolyzable group, and its hydrolysis condensate, since cracks of the antiglare film are sufficiently suppressed even when the film thickness is large. It is preferable to include at least one or both of the above. The silica precursor may further contain a silica precursor (A2) other than the silane compound (A1) and its hydrolysis condensate, if necessary.

(Silane compound (A1))
The silane compound (A1) has a hydrocarbon group and a hydrolyzable group bonded to a silicon atom. The hydrocarbon group is one selected from —O—, —S—, —CO— and —NR′— (wherein R ′ is a hydrogen atom or a monovalent hydrocarbon group) between carbon atoms, or You may have group which combined 2 or more.

  The hydrocarbon group may be a monovalent hydrocarbon group bonded to one silicon atom, or may be a divalent hydrocarbon group bonded to two silicon atoms. Examples of the monovalent hydrocarbon group include an alkyl group, an alkenyl group, and an aryl group. Examples of the divalent hydrocarbon group include an alkylene group, an alkenylene group, and an arylene group.

  Examples of the hydrolyzable group include an alkoxy group, an acyloxy group, a ketoxime group, an alkenyloxy group, an amino group, an aminoxy group, an amide group, an isocyanate group, a halogen atom, and the like, and the stability and hydrolysis of the silane compound (A1). From the viewpoint of balance with ease of handling, an alkoxy group, an isocyanate group and a halogen atom (particularly a chlorine atom) are preferred. As an alkoxy group, a C1-C3 alkoxy group is preferable and a methoxy group or an ethoxy group is more preferable. When a plurality of hydrolyzable groups are present in the silane compound (A1), the hydrolyzable groups may be the same group or different groups, and it is easy to obtain that they are the same group. This is preferable.

  Examples of the silane compound (A1) include a compound represented by the formula (I) described later, an alkoxysilane having an alkyl group (methyltrimethoxysilane, ethyltriethoxysilane, etc.), an alkoxysilane having a vinyl group (vinyltrimethoxysilane). , Vinyltriethoxysilane, etc.), alkoxysilanes having an epoxy group (2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane) , 3-glycidoxypropyltriethoxysilane, etc.), alkoxysilanes having an acryloyloxy group (3-acryloyloxypropyltrimethoxysilane, etc.) and the like.

As the silane compound (A1), a compound represented by the following formula (I) is preferable from the viewpoint that cracks in the antiglare film can be sufficiently suppressed even when the film thickness is large.
R _3-p L _p Si-Q-SiL _p R _3-p (I)

Q is from a divalent hydrocarbon group (-O-, -S-, -CO- and -NR'- (wherein R 'is a hydrogen atom or a monovalent hydrocarbon group) between carbon atoms). It may have a group obtained by combining one or two or more selected.).
Q is preferably an alkyl group having 2 to 8 carbon atoms and is preferably an alkyl group having 2 to 6 carbon atoms because it is easily available and the crack of the antiglare film can be sufficiently suppressed even when the film thickness is large. Further preferred.

L is a hydrolyzable group. Examples of the hydrolyzable group include those described above, and preferred embodiments are also the same.
R is a hydrogen atom or a monovalent hydrocarbon group. Examples of the monovalent hydrocarbon include those described above.
p is an integer of 1 to 3. p is preferably 2 or 3, particularly preferably 3, from the viewpoint that the reaction rate does not become too slow.

(Other silica precursor (A2))
Other silica precursors (A2) include hydrolyzed condensates (sol-gel silica) of alkoxysilanes (excluding the silane compound (A1)) and alkoxysilanes (excluding the silane compound (A1)). ), Silazane and the like, and from the viewpoint of each characteristic of the antiglare film, either one or both of alkoxysilane (however, excluding the silane compound (A1)) and its hydrolysis condensate are preferable. A hydrolysis condensate of (except for the silane compound (A1)) is more preferred.

  Examples of the alkoxysilane (excluding the silane compound (A1)) include tetraalkoxysilane (tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, and the like).

(Hydrolysis condensate)
In the case of tetraalkoxysilane, hydrolysis of the alkoxysilane is performed using water and an acid catalyst that are 4 times or more moles of alkoxysilane. Examples of the acid catalyst include inorganic acids (such as nitric acid, sulfuric acid, and hydrochloric acid) and organic acids (such as formic acid, oxalic acid, monochloroacetic acid, dichloroacetic acid, and trichloroacetic acid).

(Inorganic particles (B))
Examples of the inorganic particles (B) include silica particles, alumina particles, zirconia particles, and titania particles. Silica particles are preferable from the viewpoint of suppressing an increase in the refractive index of the film and reducing the reflectance.

  The inorganic particles (B) preferably contain at least scale-like particles (B1) from the viewpoint that cracks in the antiglare film can be sufficiently suppressed even when the film thickness is large. The inorganic particles (B) may further include other inorganic particles (B2) other than the scaly particles (B1) as necessary.

(Scale-like particles (B1))
The average aspect ratio of the scaly particles (B1) is preferably 50 to 650, more preferably 100 to 350, and still more preferably 170 to 240. If the average aspect ratio of the scaly particles (B1) is 50 or more, cracks in the antiglare film can be sufficiently suppressed even if the film thickness is large. When the average aspect ratio of the scaly particles (B1) is 650 or less, the dispersion stability in the coating solution is good.

  The average particle diameter of the scaly particles (B1) is preferably 0.08 to 0.42 μm, and more preferably 0.17 to 0.21 μm. If the average particle diameter of the scale-like particles (B1) is 0.08 μm or more, cracks in the antiglare film can be sufficiently suppressed even if the film thickness is large. When the average particle size of the scaly particles (B1) is 0.42 μm or less, the dispersion stability in the coating solution is good.

  Examples of the scaly particles (B1) include scaly silica particles, scaly alumina particles, scaly zirconia particles, scaly titania, and the like, which can suppress an increase in the refractive index of the film and reduce the reflectance. Scaly silica particles are preferred.

The flaky silica particles are flaky silica primary particles or silica secondary particles formed by laminating and laminating a plurality of flaky silica primary particles in parallel with each other. The silica secondary particles usually have a particle form of a laminated structure.
The scaly silica particles may be either one of the silica primary particles and the silica secondary particles, or both.

The thickness of the silica primary particles is preferably 0.001 to 0.1 μm. If the thickness of the silica primary particles is within the above range, scaly silica secondary particles in which one or a plurality of sheets are superposed with the planes oriented parallel to each other can be formed.
The ratio of the minimum length to the thickness of the silica primary particles is preferably 2 or more, more preferably 5 or more, and still more preferably 10 or more.

The thickness of the silica secondary particles is preferably 0.001 to 3 μm, and more preferably 0.005 to 2 μm.
The ratio of the minimum length to the thickness of the silica secondary particles is preferably 2 or more, more preferably 5 or more, and still more preferably 10 or more.
The silica secondary particles are preferably present independently of each other without fusing.

The SiO ₂ purity of the scaly silica particles is preferably 95.0% by mass or more, and more preferably 99.0% by mass or more.
For the preparation of the coating solution, a powder that is an aggregate of a plurality of scaly silica particles or a dispersion in which the powder is dispersed in a liquid medium is used. The silica concentration in the dispersion is preferably 1 to 80% by mass.

The powder or dispersion may contain not only scaly silica particles but also amorphous silica particles generated during the production of scaly silica particles. The scaly silica particles are, for example, pulverized and dispersed aggregated silica tertiary particles (hereinafter also referred to as silica aggregates) having gaps formed by irregularly overlapping the scaly silica particles. To obtain. Amorphous silica particles are in a state in which silica aggregates are atomized to some extent, but are not in the state of being atomized to individual scaly silica particles, and a shape in which a plurality of scaly silica particles form a lump. It is. If the amorphous silica particles are included, the denseness of the antiglare film to be formed may be reduced, and cracks may easily occur. Therefore, the smaller the content of amorphous silica particles in the powder or dispersion, the better.
The amorphous silica particles and the silica aggregates are both observed in black in TEM observation. On the other hand, the flaky silica primary particles or silica secondary particles are observed to be transparent or translucent in TEM observation.

As the flaky silica particles, commercially available ones may be used, or those produced may be used.
The scaly silica particles are preferably produced by the production method (P) described later. According to the production method (P), compared to a known production method (for example, the method described in Japanese Patent No. 4063464), the generation of amorphous silica particles in the production process is suppressed, and the inclusion of amorphous silica particles. A small amount of powder or dispersion can be obtained.

(Method for producing scaly silica particles (P))
The production method (P) includes a step of acid-treating silica powder containing silica aggregates in which scaly silica particles are aggregated at a pH of 2 or less, and alkali-treating the acid-treated silica powder at pH of 8 or more to obtain a silica aggregate. A peptization step and a step of wet crushing the alkali-treated silica powder to obtain scaly silica particles.

As the silica aggregate, so-called layered polysilicic acid and / or a salt thereof can be used. The layered polysilicic acid is a polysilicate having a silicate layer structure in which the basic structural unit is a SiO ₄ tetrahedron. Examples of the layered polysilicic acid and / or a salt thereof include silica-X (SiO ₂ -X), silica-Y (SiO ₂ -Y), Kenyaite, magadiite, macatite, islayite, kanemite, octosilicate, and the like. Silica-X or Silica-Y is preferred.

Silica-X and silica-Y are intermediate phases or metastable phases generated in the process of hydrotreating silica raw material to form cristobalite or quartz (quartz), and should also be referred to as quasicrystalline of silica. It is a weak crystal phase.
Silica-X and silica-Y have different X-ray diffraction patterns, but the appearance of particles observed with an electron microscope is very similar, and both can be preferably used to obtain scaly silica particles.

The spectrum of X-ray diffraction of silica-X is 2θ = 4.9 corresponding to a card (hereinafter simply referred to as an “ASTM card”) number 16-0380 registered in the American ASTM (American Society for Testing and Materials). Characterized by main peaks at °, 26.0 °, and 28.3 °.
The X-ray diffraction spectrum of silica-Y is characterized by main peaks at 2θ = 5.6 °, 25.8 ° and 28.3 ° corresponding to ASTM card number 31-1233.
The X-ray diffraction spectrum of the silica aggregate is preferably characterized by the main peak of silica-X and / or silica-Y.

"Formation of silica powder"
Examples of a method for forming a silica powder containing silica aggregates include a method in which one or more of silica hydrogel, silica sol and hydrous silicic acid are hydrothermally treated in the presence of an alkali metal salt. Note that the silica powder is not limited to those formed by this method, but includes those formed by an arbitrary method.

When the starting material is silica hydrogel:
By using silica hydrogel as a starting material, silica-X, silica-Y, etc. can be formed as silica aggregates in a low temperature, short-time reaction without producing crystals such as quartz and with high yield. .
As the silica hydrogel, particulate silica hydrogel is preferable. The particle shape of the silica hydrogel may be spherical or irregular. The method for granulating the silica hydrogel can be selected as appropriate.

  As a method for granulating the spherical silica hydrogel, for example, (α) a method of solidifying a silica hydrosol into a spherical shape in a liquid medium such as petroleum, (β) an alkali metal silicate aqueous solution and a mineral acid aqueous solution are used. A method of mixing to produce silica sol in a short time, releasing it into a gaseous medium, and gelling in the gas can be mentioned, and the method (β) is preferred. Examples of the mineral acid aqueous solution include a sulfuric acid aqueous solution, hydrochloric acid, and a nitric acid aqueous solution.

Specific examples of the method (β) are as follows.
An alkali metal silicate aqueous solution and a mineral acid aqueous solution are introduced into a container provided with a discharge port from a separate inlet and instantaneously uniformly mixed, and the SiO ₂ concentration is 130 g / L or more and the pH is 7 to 9. A silica sol is produced. The silica sol is discharged from a discharge port into a gaseous medium such as air and gelled in the air. The gelled product is dropped into an aging tank filled with water and aged for several minutes to several tens of minutes, an acid is added, and it is washed with water to obtain a spherical silica hydrogel.

The obtained silica hydrogel is a transparent and elastic spherical particle having an average particle diameter of about 2 to 10 mm with a uniform particle diameter, and may contain about 4 times as much water as SiO ₂ in mass ratio. The SiO ₂ concentration in the silica hydrogel is preferably 15 to 75% by mass.

When the starting material is silica sol:
As the silica sol, it is preferable to use a silica sol containing a specific amount of silica and an alkali metal.
As a silica sol, a molar ratio (SiO ₂ / Me ₂ ) between silica (SiO ₂ equivalent) and alkali metal (Me ₂ O equivalent; Me is an alkali metal such as Li, Na, K, etc. The same shall apply hereinafter). A silica sol obtained by dealkalizing an alkali metal silicate aqueous solution having an O) of 1.0 to 3.4 by an ion exchange resin method, an electrodialysis method, or the like is preferably used. SiO ₂ / Me ₂ O is preferably 3.5 to 20, 4.5 to 18 is more preferable.
As the alkali metal silicate aqueous solution, water glass (sodium silicate aqueous solution) appropriately diluted with water or the like is preferable.

SiO ₂ concentration in the silica sol is preferably from 2 to 20 wt%, and more preferably 3 to 15 wt%.
The average particle size of silica in the silica sol is preferably 1 to 100 nm. When the average particle diameter is 100 nm or less, the stability of the silica sol is good.
As the silica sol, those having an average particle diameter of 1 to 20 nm or less called active silicic acid are particularly preferable.

If the starting material is hydrous silicic acid:
When hydrous silicic acid is used as a starting material, silica powder containing silica aggregates can be formed by the same method as silica sol.

Hydrothermal treatment:
Silica powder containing silica agglomerates by performing hydrothermal treatment by heating one or more silica sources of silica hydrogel, silica sol and hydrous silicic acid in a heated pressure vessel such as an autoclave in the presence of an alkali metal salt The body can be formed.
Since the silica source is hydrothermally treated, purified water such as distilled water or ion exchange water may be further added to adjust the silica concentration to a desired range prior to charging the autoclave.
When a spherical silica hydrogel is used, it may be used as it is, or it may be pulverized or coarsely pulverized so that the average particle diameter is about 0.1 to 6 mm.

The type of the autoclave is not particularly limited. The autoclave may be provided with at least a heating means, a stirring means, and preferably a temperature measuring means.
The total SiO ₂ concentration in the treatment liquid in the autoclave is selected in consideration of stirring efficiency, crystal growth rate, yield and the like, and is usually preferably 1 to 30% by mass, and 10 to 20% by mass on the basis of all charged raw materials. Is more preferable. The total SiO ₂ concentration in the treatment solution is that the total SiO ₂ concentration in the system, SiO ₂ not only in the silica source, in the case of using sodium silicate or the like as an alkali metal salt, sodium silicate, etc. This is a value obtained by adding SiO ₂ brought into the system.

  In hydrothermal treatment, by coexisting an alkali metal salt with the silica source, the pH of the treatment liquid is adjusted to the alkali side, the silica solubility is increased moderately, the crystallization rate based on the so-called Ostwald ripening is increased, and the silica hydrogel Can be converted to silica-X and / or silica-Y.

Examples of the alkali metal salt include alkali metal hydroxide, alkali metal silicate, alkali metal carbonate, and the like, or a combination thereof. Examples of the alkali metal include Li, Na, K, and the like, or a combination thereof. The pH of the system is preferably 7 or more, more preferably 8 to 13, and further preferably 9 to 12.5. The molar ratio between the total SiO ₂ and an alkali metal (Me ₂ O equivalent) in the system _(SiO 2 / _Me 2 O) is preferably 4 to 15, 7 to 13 is more preferable.

  Hydrothermal treatment of silica sol or hydrous silicic acid is preferably performed at 150 to 250 ° C, more preferably 170 to 220 ° C, from the viewpoint of increasing the reaction rate and decreasing the progress of crystallization. The time for hydrothermal treatment of silica hydrosol or hydrous silicic acid can vary depending on the temperature of hydrothermal treatment, the presence or absence of addition of seed crystals, etc., but is preferably 3 to 50 hours, more preferably 3 to 40 hours, and more preferably 5 to 25 hours. Is more preferable.

  The hydrothermal treatment of silica hydrogel is preferably performed at 150 to 220 ° C, more preferably 160 to 200 ° C, and further preferably 170 to 195 ° C. The hydrothermal treatment time of the silica hydrogel may vary depending on the hydrothermal treatment temperature, the presence or absence of addition of seed crystals, etc., but is preferably 3 to 50 hours, more preferably 5 to 40 hours, even more preferably 5 to 25 hours. ˜12 hours is particularly preferred.

Promoting hydrothermal treatment efficiently, in order to shorten the processing time, that the charge of the silica source with respect to (SiO ₂ conversion) adding from 0.001 to 1 mass% of seed crystals (SiO ₂ conversion) preferable. As a seed crystal, silica-X, silica-Y, etc. can be used as they are or after being appropriately pulverized.

  After the hydrothermal treatment is complete, the product is removed from the autoclave, filtered and washed with water. The pH of the particles after the water washing treatment is preferably 5 to 9 and more preferably 6 to 8 when a 10% by mass water slurry is formed.

"Silica powder"
The average particle size of the obtained silica powder is preferably 7 to 25 μm, more preferably 7 to 11 μm.
The silica powder includes a silica aggregate in which scaly silica particles are aggregated. The silica aggregate is an aggregate-shaped silica tertiary particle having a gap formed by irregularly overlapping the scaly silica particles. The silica aggregate can be confirmed by using a scanning electron microscope (hereinafter also referred to as SEM) of the silica powder.

  In SEM, the flaky silica primary particles cannot be identified, and the flaky silica secondary particles formed by overlapping a plurality of the silica primary particles that are oriented parallel to each other in the plane can be identified. On the other hand, TEM can identify primary silica particles that are ultrathin piece particles through which an electron beam is partially transmitted. Further, it is possible to identify silica secondary particles in which the primary silica particles are aligned in parallel with each other and overlap each other. Silica primary particles and silica secondary particles are scaly silica particles.

  It is said that it is difficult to separate and isolate the flaky silica primary particles, which are the structural units, from the flaky silica secondary particles one by one. That is, in the layered overlap of the flaky silica primary particles, the bonds between the layers are strong and fused and integrated. Therefore, it is said that it is difficult to further crush the scaly silica secondary particles into silica primary particles. According to the production method (P), it is possible to make fine particles from silica aggregates to scaly secondary silica particles, and even fine particles like flaky silica primary particles.

"Acid treatment"
As an acid treatment method, an acidic liquid is added to a dispersion containing silica powder (including a slurry dispersion) (hereinafter also referred to as a silica dispersion) so that the pH of the system is 2 or less. And the method of processing with stirring arbitrarily is mentioned.
By treating the silica powder containing the silica aggregate with an acid treatment at a pH of 2 or less, the peptization of the silica aggregate can be promoted in the subsequent alkali treatment, and the generation of amorphous silica particles can be suppressed after the wet crushing step. .
Moreover, the alkali metal salt contained in a silica powder can be removed by performing an acid treatment. When the silica powder is formed by hydrothermal treatment, an alkali metal salt is added in the hydrothermal treatment.

The pH of the acid treatment may be 2 or less, and preferably 1.9 or less. By performing the acid treatment at a low pH in advance, the silica aggregates can be more easily peptized and crushed in the subsequent alkali treatment and wet crushing steps.
The acid treatment is preferably performed at room temperature for 8 hours or longer in order to sufficiently perform the treatment.

As the acidic solution, an aqueous mineral acid solution such as a sulfuric acid aqueous solution, hydrochloric acid, nitric acid aqueous solution or the like can be used. The concentration of the mineral acid is preferably 1 to 37% by mass.
The SiO ₂ concentration in the silica dispersion is preferably 5 to 15% by mass. The pH of the silica dispersion is preferably 10-12.
The mixing ratio of the silica dispersion and the acidic liquid may be adjusted so that the pH is 2 or less, and is not particularly limited.

It is preferable to wash the silica powder after acid treatment of the silica dispersion. By washing, the alkali metal salt mixed by the hydrothermal treatment or a product derived therefrom can be removed.
Examples of the washing method include a method of washing with water when the silica dispersion is filtered or centrifuged.
The silica dispersion after washing may be adjusted by adding water or concentrating it to adjust the solid content concentration. When recovered as a silica cake after washing, water can be added to form a silica dispersion. The pH of the silica dispersion after washing is preferably 4-6.

"Aluminic acid treatment"
The silica powder after acid treatment may optionally be subjected to aluminate treatment.
By the treatment with aluminate, aluminum (Al) can be introduced into the surface of the silica particles in the silica powder and the surface can be modified so as to be negatively charged. Negatively charged silica powder can enhance dispersibility in acidic media.

Examples of the aluminate treatment method include a method in which an aqueous solution of aluminate is added to a silica dispersion, optionally stirred and mixed, and then heat treated to introduce Al into the surface of the silica particles.
The mixing is preferably performed at 10 to 30 ° C. for 0.5 to 2 hours.
The heat treatment is preferably performed under heating and reflux conditions, and is preferably performed at 80 to 110 ° C. for 4 hours or more.

Examples of the aluminate include sodium aluminate and potassium aluminate, and combinations thereof, and sodium aluminate is preferable.
The molar ratio (Al ₂ O ₃ / SiO ₂ ) between the aluminate salt (Al ₂ O ₃ equivalent) and the silica powder (SiO ₂ equivalent) is preferably 0.00040 to 0.00160.
As for the density | concentration of the aqueous solution of aluminate, 1-3 mass% is preferable.
The amount of the aluminate aqueous solution added is preferably 5.8 to 80.0 parts by mass with respect to 100 parts by mass of SiO ₂ in the silica dispersion.
The SiO ₂ concentration in the silica dispersion is preferably 5 to 20% by mass. The pH of the silica dispersion is preferably 6-8.

  The silica dispersion after the treatment with aluminate may be adjusted by adding water or concentrating it to adjust the solid content. The pH of the silica dispersion after the aluminate treatment is preferably 6-8.

"Alkaline treatment"
The silica powder after acid treatment and, if necessary, aluminate treatment is alkali-treated at pH 8 or more, and the silica aggregate is peptized.
By the alkali treatment, the strong bonds of the silica aggregates can be peptized to approach the form of individual scaly silica particles.

Peptizing the silica aggregate means imparting a charge to the silica aggregate and dispersing individual silica particles in the medium.
Almost all of the silica particles contained in the silica powder may be peptized into individual scaly silica particles by alkali treatment, or only a part thereof may be peptized to leave an aggregate. In addition, the silica aggregate contained in the silica dispersion may be peptized into individual scale-like silica particles, or only a part thereof may be peptized to leave the aggregate part. The remaining agglomerates can be crushed into individual scaly silica particles in a subsequent wet crushing step.

  The pH of the alkali treatment may be 8 or more, preferably 8.5 or more, and more preferably 9 or more. If the pH of the alkali treatment is 8 or more, peptization of the silica aggregates contained in the silica powder can be promoted. Further, even if the silica aggregate remains after the alkali treatment, the binding of the silica aggregate to the scaly silica particles can be weakened, and it is easy to disintegrate into individual scaly silica particles in the subsequent wet crushing step.

Examples of the alkali treatment method include a method in which an alkaline liquid is added to the silica dispersion so that the pH is 8 or more, and the treatment is optionally performed with stirring. Instead of the alkaline liquid, an alkali metal salt and water may be added separately.
The alkali treatment is preferably performed at 10 to 50 ° C. for 1 to 48 hours, more preferably 2 to 24 hours.

Examples of the alkali metal salt include hydroxides of alkali metals such as lithium (Li), sodium (Na), and potassium (K), carbonates, and the like, and combinations thereof.
An aqueous solution containing an alkali metal salt can be used as the alkaline liquid. Aqueous ammonia (NH ₄ ⁺ OH ⁻ ) may be used as the alkaline liquid.

The concentration of alkali metal salt in the silica dispersion (mass of alkali metal salt / total mass of water and alkali metal salt in silica dispersion × 100) is preferably 0.01 to 28% by mass, and 0.04 to 5 mass% is more preferable and 0.1-2.5 mass% is further more preferable.
The amount of the alkali metal salt is preferably 0.4 to 2.5 mmol, more preferably 0.5 to 2 mmol, with respect to 1 g of SiO ₂ in the silica dispersion.
The SiO ₂ concentration in the silica dispersion is preferably 3 to 7% by mass. The pH of the silica dispersion is preferably 8-11.
What is necessary is just to adjust so that pH may become 8 or more about the mixture ratio of a silica dispersion and an alkaline liquid, and it does not restrict | limit in particular.

The average particle diameter of the silica powder contained in the silica dispersion after the alkali treatment is preferably 3 to 10 μm, and more preferably 4 to 8.5 μm.
To the silica dispersion after the alkali treatment, water may be added or concentrated to adjust the solid content. The pH of the silica dispersion after the alkali treatment is preferably 8.0 to 12.5.

"Wet disintegration"
The alkali-treated silica powder is wet pulverized to obtain scaly silica particles.
The silica powder subjected to the alkali treatment includes amorphous silica particles in which the silica aggregates are peptized and a part of the remaining silica aggregates and the silica aggregates are atomized to some extent. By wet crushing this, the amorphous silica particles can be further crushed to obtain individual scaly silica particles. By carrying out the alkali treatment in advance, the crushing of the amorphous silica particles can be promoted in the wet crushing. Therefore, the amount of amorphous silica particles that remain without being sufficiently crushed can be suppressed.

  Wet crushing equipment includes wet crushing equipment (crushing) such as a wet bead mill, a wet ball mill, a thin-film swirl type high-speed mixer, and an impact crushing device (such as Nanomizer) that mechanically stirs at high speed using a crushing medium. Apparatus). In particular, in a wet bead mill, if medium beads such as alumina or zirconia having a diameter of 0.2 to 1 mm are used, the basic laminated structure of scaly silica particles should be crushed and dispersed so as not to be crushed and destroyed as much as possible. Is preferable. The impact pulverizer is a device in which a dispersion containing powder is put into a thin tube of 80 to 1000 μm under pressure, and the particles in the dispersion are collided with each other and dispersed. Use an impact pulverizer. Can break up the particles more finely.

The silica powder to be wet pulverized is preferably supplied to a wet pulverizer at a suitable concentration as a dispersion in purified water such as distilled water or ion exchange water.
The SiO ₂ concentration in the dispersion is preferably 0.1 to 20% by mass, and more preferably 0.1 to 15% by mass in consideration of the crushing efficiency and work efficiency due to the increase in viscosity.

"Cation exchange treatment"
The silica powder after wet crushing may optionally be subjected to cation exchange treatment.
By performing cation exchange treatment, cations, particularly metal ions, contained in the silica powder can be removed.

  As a method of the cation exchange treatment, there may be mentioned a method in which a cation exchange resin is added to a silica dispersion containing silica powder and the treatment is optionally performed with stirring. The cation exchange treatment is preferably performed at 10 to 50 ° C. for 0.5 to 24 hours.

Examples of the resin matrix of the cation exchange resin include styrene resins such as styrene-divinylbenzene, and (meth) acrylic acid resins.
As the cation exchange resin, a hydrogen type (H type) cation exchange resin is preferable, and examples thereof include a cation exchange resin having a sulfonic acid group, a carboxyl group, or a phosphoric acid group. The amount of the cation exchange resin is preferably 3 to 20 parts by mass with respect to 100 parts by mass of SiO ₂ in the silica dispersion.
The SiO ₂ concentration in the silica dispersion is preferably 3 to 20% by mass. The pH of the silica dispersion is preferably 4 or less.

(Other inorganic particles (B2))
Examples of other inorganic particles (B2) include spherical silica particles, spherical alumina particles, spherical zirconia particles, and spherical titania. As other inorganic particles (B2), the haze of the article with the antiglare film is sufficiently high, and the 60 ° specular gloss on the surface of the antiglare film is sufficiently low, and as a result, the antiglare effect is sufficiently high. From the viewpoint of exhibiting, spherical silica particles are preferable, and porous spherical silica particles are more preferable.

  The average particle diameter of the other inorganic particles (B2) is preferably 0.3 to 2 μm, and more preferably 0.5 to 1.5 μm. If the average particle diameter of the other inorganic particles (B2) is 0.3 μm or more, the antiglare effect is sufficiently exhibited. When the average particle diameter of the other inorganic particles (B2) is 2 μm or less, the dispersion stability in the coating solution is good.

The BET specific surface area of the porous spherical silica particles is preferably 200 to 300 m ² / g.
The pore volume of the porous spherical silica particles is preferably 0.5 to 1.5 cm ³ / g.
As a commercially available product of the porous spherical silica particles, there can be mentioned Light Star (registered trademark) series manufactured by Nissan Chemical Industries.

(Liquid medium (C))
The liquid medium (C) is a solvent for dissolving the matrix precursor (A), and is a dispersion medium for dispersing the inorganic particles (B).

  Examples of the liquid medium (C) include water, alcohols, ketones, ethers, cellosolves, esters, glycol ethers, nitrogen-containing compounds, sulfur-containing compounds and the like.

Examples of alcohols include methanol, ethanol, isopropanol, butanol, diacetone alcohol and the like.
Examples of ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone.
Examples of ethers include tetrahydrofuran and 1,4-dioxane.
Examples of cellosolves include methyl cellosolve and ethyl cellosolve.
Examples of esters include methyl acetate and ethyl acetate.
Examples of glycol ethers include ethylene glycol monoalkyl ether.
Examples of nitrogen-containing compounds include N, N-dimethylacetamide, N, N-dimethylformamide, N-methylpyrrolidone and the like.
Examples of the sulfur-containing compound include dimethyl sulfoxide.
A liquid medium (C) may be used individually by 1 type, and may be used in combination of 2 or more type.

Since water is required for hydrolysis of alkoxysilane and the like in the matrix precursor (A), the liquid medium (C) contains at least water unless the liquid medium is replaced after hydrolysis of the alkoxysilane.
The liquid medium (C) may be a mixed liquid of water and another liquid. Examples of other liquids include alcohols, ketones, ethers, cellosolves, esters, glycol ethers, nitrogen-containing compounds, and sulfur-containing compounds. Among the other liquids, as the solvent for the matrix precursor (A), alcohols are preferable, and methanol, ethanol, isopropyl alcohol, and butanol are particularly preferable.

(Acid catalyst (D))
The acid catalyst (D) is a component that accelerates hydrolysis and condensation of the matrix precursor and forms a coating film in a short time.
The acid catalyst (D) may be added for hydrolysis and condensation of raw materials (alkoxysilane, etc.) during the preparation of the solution of the matrix precursor (A), and is an application composed of essential components. It may be further added after preparing the liquid.
Examples of the acid catalyst (D) include inorganic acids (such as nitric acid, sulfuric acid, and hydrochloric acid) and organic acids (such as formic acid, oxalic acid, monochloroacetic acid, dichloroacetic acid, and trichloroacetic acid).

(Additive (E))
The coating liquid may further contain an additive (E) as long as it does not impair the effects of the present invention.
Examples of the additive (E) include ultraviolet absorbers, infrared reflection / infrared absorbers, antireflection agents, surfactants for improving leveling properties, metal compounds for improving durability, and the like.

(Application method)
As a coating method, known wet coating methods (spray coating method, spin coating method, dip coating method, die coating method, curtain coating method, screen coating method, ink jet method, flow coating method, gravure coating method, bar coating method, flexographic method) Coating method, slit coating method, roll coating method, etc.).
As a coating method, a spray method is preferable because sufficient unevenness can be easily formed.

Examples of the nozzle used in the spray method include a two-fluid nozzle and a one-fluid nozzle.
The particle size of the droplets of the coating liquid discharged from the nozzle is usually 0.1 to 100 μm, and preferably 1 to 50 μm. If the particle size of the droplets is 1 μm or more, it is possible to form irregularities that sufficiently exhibit the antiglare effect in a short time. If the particle size of the droplet is 50 μm or less, it is easy to form moderate unevenness that sufficiently exhibits the antiglare effect.

The particle size of the droplets can be adjusted as appropriate according to the type of nozzle, spray pressure, liquid volume, and the like. For example, in a two-fluid nozzle, the higher the spray pressure, the smaller the droplet, and the larger the liquid volume, the larger the droplet.
The particle size of the droplet is the Sauter average particle size measured by a laser measuring device.

  The arithmetic average roughness Ra and 60 ° specular glossiness of the surface of the antiglare film can be adjusted by applying time, that is, the number of coated surfaces (number of overcoating) by a spray method under a certain application condition. As the number of coated surfaces increases, the arithmetic average roughness Ra of the surface of the antiglare film increases. As a result, the 60 ° specular gloss decreases, the reflected image becomes unclear (the antiglare effect increases), and the haze is Increases (contrast decreases).

  When applying the coating solution by the spray method, it is preferable to heat the substrate to 30 to 90 ° C. in advance. If the temperature of a base material is 30 degreeC or more, since a liquid medium (C) will evaporate quickly, it will be easy to form sufficient unevenness | corrugation. If the temperature of a base material is 90 degrees C or less, the adhesiveness of a base material and an anti-glare film will become favorable. In the case where the substrate is a glass plate having a thickness of 5 mm or less, a heat insulating plate that has been set to a temperature equal to or higher than the temperature of the substrate in advance may be disposed under the substrate to suppress a decrease in the temperature of the substrate.

[Step (ii)]
The hydrolyzable group remaining in the coating film is hydrolyzed and condensed by bringing the aqueous solution having a pH of 10 to 12.5 into contact with the coating film formed in the step (i). Since the condensation by the alkali catalyst proceeds three-dimensionally, gelation occurs rapidly and the remaining hydrolyzable groups are greatly reduced.

(Alkaline aqueous solution)
The aqueous alkaline solution may be one in which an alkaline catalyst is dissolved in water, or electrolytic reduced water. In the case of an alkali catalyst, the coating film is contaminated by metal ions or the like, and there is a possibility that the durability may be adversely affected. For this reason, electrolytic reduced water is preferable as the alkaline aqueous solution.

Examples of the alkali catalyst include ammonia, sodium hydroxide, potassium hydroxide and the like.
The electrolytic reduced water may be commercially available electrolytic reduced water (so-called alkaline ion water); using a commercially available alkaline ion water conditioner or the like, water containing electrolyte (tap water, electrolyte added water, etc.) is publicly known. It may be produced by electrolysis by an electrolytic method (ion exchange method, diaphragm method, mercury method, etc.).
The electrolytically reduced water contains cations derived from the electrolyte, and hydroxide ions and hydrogen molecules generated by electrolysis. Since electrolytically reduced water contains hydrogen molecules, the oxidation-reduction potential is lower than that obtained by dissolving an alkali catalyst in water.

  The pH of the alkaline aqueous solution is 10 to 12.5, preferably 10.5 to 12, and more preferably 10.5 to 11.5. If the pH of the aqueous alkali solution is 10 or more, hydrolysis and condensation of the hydrolyzable group proceed rapidly. When the pH of the alkaline aqueous solution exceeds 12.5, the formed coating film is likely to be eroded or deteriorated.

(Contact method)
Examples of the method of bringing the aqueous solution into contact with the coating film include a method of immersing an article with a coating film in an aqueous alkaline solution;
The contact time is preferably 0.5 to 5 minutes, more preferably 1 to 3 minutes. When the contact time exceeds 5 minutes, the formed coating film is likely to be eroded or deteriorated.
It is preferable to wash the coating film with water after contacting the coating solution with the alkaline aqueous solution.

[Step (iii)]
By baking the coating film after the step (ii), the remaining hydrolyzable groups are substantially decomposed and the film is densified to form an antiglare film.

The firing temperature is preferably 200 ° C. or higher, more preferably 300 to 480 ° C., and further preferably 300 to 450 ° C. When the firing temperature is 200 ° C. or higher, an antiglare film having sufficiently high wear resistance is formed. If the firing temperature is lower than 480 ° C., it is easy to control internal stress that causes cracks.
The firing time is preferably 10 to 120 minutes, more preferably 30 to 60 minutes.

<Action mechanism>
In the article with an antiglare film of the present invention described above, the haze of the article is 15% or more, and the 60 ° specular gloss on the surface of the antiglare film is 25% or less. Since the arithmetic average roughness Ra of the surface is 0.17 μm or more, the antiglare effect is higher than the conventional one.

  Moreover, in the manufacturing method of the articles | goods with an anti-glare film of this invention demonstrated above, the coating liquid containing a matrix precursor (A), an inorganic particle (B), and a liquid medium (C) is used as a base material. After coating to form a coating film, the coating solution is brought into contact with an alkaline aqueous solution having a pH of 10 to 12.5. For the following reason, the coating solution is used to increase the antiglare effect of the antiglare film. The anti-glare film is cracked and colored even if the coating film with a thick film is baked at a high temperature in order to increase the film thickness of the anti-glare film and improve the wear resistance of the anti-glare film. It can be suppressed.

When the coating solution is applied to form a coating film, when the coating solution contains an acid catalyst (D), a linear polymer is mainly formed. Therefore, many unreacted hydrolyzable groups remain. When the coating film is baked in a state where many unreacted hydrolyzable groups remain, the reaction of the unreacted hydrolyzable group proceeds and the coating film shrinks. Since the shrinkage of the coating film becomes more noticeable as the film thickness increases, cracks occur in the antiglare film. Moreover, when the film thickness of a coating film is thick, the organic substance which generate | occur | produces by reaction of a hydrolysable group will be confined in a film | membrane. If baking is continued at a high temperature in a state where the organic matter is confined in the film, the organic matter is decomposed and the antiglare film is colored by carbon or the like.
On the other hand, in the present invention, before the coating film is fired, the hydrolyzable group remaining in the coating film is hydrolyzed and condensed by contacting the coating film with an alkaline aqueous solution having a pH of 10 to 12.5. To do. Since the condensation with the alkali catalyst proceeds rapidly, the remaining hydrolyzable groups are greatly reduced. Therefore, even if the coating film having a thick film thickness by recoating the coating solution is baked at a high temperature, cracks and coloring of the antiglare film can be suppressed.

<Image display device>
The image display device of the present invention includes an image display device main body for displaying an image, and an article with an antiglare film of the present invention provided on the viewing side of the image display device main body.

Examples of the image display device main body include a liquid crystal panel, an organic EL panel, a plasma display panel, and the like.
The article with the antiglare film may be provided integrally with the image display device main body as a protective plate of the image display device main body, or may be disposed on the viewing side of the image display device main body as various filters.

  In the image display device of the present invention described above, the article with the antiglare film of the present invention having a high antiglare effect is provided on the viewing side of the image display device main body, so that the visibility is good.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by the following description.
Examples 1 to 17 are examples, and examples 18 to 25 are comparative examples.

(Haze)
The haze of the article with an antiglare film was measured at a substantially central portion of the antiglare film by a method described in JIS K 7136: 2000 using a haze meter (manufactured by Murakami Color Research Laboratory, HM-150L2).

(60 ° specular gloss)
The 60 ° specular glossiness of the surface of the antiglare film is measured using a gloss meter (Nippon Denshoku Kogyo Co., Ltd.) for an article with an antiglare film with a black tape attached to the surface opposite to the side on which the antiglare film is formed. (Manufactured by PG-3D), and measured at approximately the center of the antiglare film by the method described in JIS Z 8741: 1997.

(Arithmetic mean roughness Ra)
The arithmetic average roughness Ra of the surface of the antiglare film was measured by a method described in JIS B 0601: 2001 using a surface roughness meter (manufactured by Tokyo Seimitsu Co., Ltd., Surfcom (registered trademark) 1500DX).

(Coloring)
The coloring of the antiglare film was evaluated by observing the antiglare film with the naked eye and by the following criteria.
○: No coloring.
Δ +: There is very little coloring.
Δ: Light coloration.
X: There is clear coloring.

(crack)
The cracks in the antiglare film were evaluated based on the following criteria for images observed at 500 times using an optical microscope.
○: There is no crack.
Δ +: There are 1 to 2 cracks.
Δ: There are 3 to 5 cracks.
X: There are 6 or more cracks.

(Abrasion resistance)
The abrasion resistance of the surface of the antiglare film is determined by attaching an eraser (Lion Corporation, GAZA1K, length 18 mm x width 11 mm) to a rubbing tester (made by Ohira Rika Kogyo Co., Ltd.), and attaching the eraser to 9.8 x 10 ^-2. Horizontal reciprocation was performed on the surface of the antiglare film at a pressure of MPa. The amount of change in the haze of the article with the antiglare film and the amount of change in the 60 ° specular glossiness of the surface of the antiglare film after the 200 times of reciprocating the eraser with respect to before 200 reciprocation of the eraser was determined. The smaller the amount of change in haze and 60 ° specular gloss, the better the wear resistance. The 60 ° specular gloss was measured on an article with an antiglare film in which a black tape was not attached to the surface opposite to the side on which the antiglare film was formed.

(Anti-glare)
The antiglare property of the antiglare film was evaluated by visually observing the reflection of the indoor fluorescent lamp (reflected image of the fluorescent lamp) on the antiglare film side of the article with the antiglare film and evaluating it according to the following criteria.
○: The reflected image is not visible.
X: A reflected image is visible.

(Production of scale-like silica particle dispersion (a))
"Formation of silica powder"
A sodium silicate aqueous solution (SiO ₂ / Na ₂ O = 3.0 (molar ratio), SiO ₂ concentration: 21.0% by mass) of 2000 mL / min and a sulfuric acid aqueous solution (sulfuric acid concentration: 20.0% by mass). Then, it was introduced into a container equipped with a discharge port from a separate introduction port and instantaneously and uniformly mixed to produce a silica sol. The flow ratio of the two liquids was adjusted so that the pH of the silica sol discharged from the discharge port into the air was 7.5 to 8.0. Silica sol was continuously released into the air from the outlet. The silica sol became spherical droplets in the air and gelled in the air while drawing a parabola and staying for about 1 second. The gelled material was dropped into an aging tank filled with water and aged. After aging, the pH was adjusted to 6 and washed thoroughly with water to obtain a silica hydrogel. The obtained silica hydrogel was spherical particles, and the average particle diameter was 6 mm. The mass ratio of water to SiO ₂ in the silica hydrogel was 4.55 times.

The silica hydrogel was coarsely pulverized to an average particle size of 2.5 mm using a double roll crusher. 7249 kg of silica hydrogel (SiO ₂ concentration: 18% by mass) so that the total SiO ₂ / Na ₂ O in the system was 12.0 (molar ratio) in an autoclave (with an anchor-type stirring blade) having a capacity of 17 m ³ and 1500 kg of an aqueous sodium silicate solution (SiO ₂ concentration: 29.00% by mass, Na ₂ O concentration: 9.42% by mass, SiO ₂ / Na ₂ O = 3.18 (molar ratio)) was charged into this, 1560 kg was added, 4682 kg of high-pressure steam having a saturation pressure of 1.67 MPa was added while stirring at 10 rpm, the temperature was raised to 185 ° C., and hydrothermal treatment was performed for 5 hours. The total SiO ₂ concentration in the system was 12.5% by mass.
The obtained silica dispersion was filtered and washed to take out silica powder and observed using TEM. It was confirmed that the silica powder contained silica aggregates. The average particle diameter of the silica powder by a laser diffraction / scattering particle size distribution measuring apparatus (Horiba, Ltd., LA-950, the same shall apply hereinafter) was 8.33 μm.

"Acid treatment"
While stirring 10100 g of a silica dispersion containing silica powder (solid content concentration measured by an infrared moisture meter: 13.3% by mass, pH: 11.4) with a stirrer, an aqueous sulfuric acid solution (sulfuric acid concentration: 20% by mass) ) Of 1083 g. The pH after the addition was 1.5. Stirring was continued for 18 hours at room temperature, and the treatment was performed.
The acid-treated silica dispersion was filtered and washed with 50 mL of water per gram of SiO ₂ . The washed silica cake was collected, and water was added to prepare a slurry-like silica dispersion. The solid content concentration of the silica dispersion measured with an infrared moisture meter was 14.7% by mass, and the pH was 4.8.

"Aluminic acid treatment"
7000 g of the silica dispersion after acid treatment was placed in a 10 L flask, and stirred with an overhead stirrer, while 197 g of an aqueous sodium aluminate solution (concentration: 2.02 mass%) (Al ₂ O ₃ / SiO ₂ = 0.00087). (Molar ratio)) was added in small portions. The pH after the addition was 7.2. After the addition, stirring was continued for 1 hour at room temperature. Then, it heated up and processed for 4 hours on heating-reflux conditions.

"Alkaline treatment"
While stirring 775 g of the silica dispersion after the aluminate treatment with a stirrer, 43.5 g of potassium hydroxide (1 mmol / g-silica) and 1381 g of water were added. The pH after addition was 9.9. Stirring was continued for 24 hours at room temperature, and the treatment was performed. The average particle diameter of the silica powder after the alkali treatment was 7.98 μm.

"Wet disintegration"
The silica dispersion after the alkali treatment is treated in 30 passes at a discharge pressure of 130 to 140 MPa using an ultra-high pressure wet atomization device (manufactured by Yoshida Kikai Kogyo Co., Ltd., Nanomizer (registered trademark) NM2-2000AR, impact diameter generator of 120 μm pore size). The silica powder was crushed and dispersed. The pH of the silica dispersion after pulverization was 9.3, and the average particle size measured by a laser diffraction / scattering particle size distribution analyzer was 0.182 μm.

"Cation exchange"
161 mL of the cation exchange resin was added to 1550 g of the crushed silica dispersion, and the mixture was treated at room temperature for 17 hours while stirring with an overhead stirrer. Thereafter, the cation exchange resin was separated. The pH of the silica dispersion after cation exchange was 3.7.

`` Density adjustment ''
The silica dispersion after cation exchange was treated with an ultrafiltration membrane (manufactured by Daisen Membrane System, MOLSEP (registered trademark), molecular weight cut off: 150,000) to adjust the concentration.
When silica particles were taken out from the obtained silica dispersion (flaky silica particle dispersion (a)) and observed with TEM, it was confirmed that they were only scaly silica particles substantially free of amorphous silica particles. It was done.
The average particle diameter of the flaky silica particles contained in the flaky silica particle dispersion (a) was the same as that after wet crushing, and was 0.182 μm. The average aspect ratio was 188.
The solid content concentration of the scaly silica particle dispersion (a) measured with an infrared moisture meter was 5.0% by mass.

[Example 1]
(Preparation of base solution (b))
While stirring 30.83 g of denatured ethanol (manufactured by Nippon Alcohol Sales Co., Ltd., Solmix (registered trademark) AP-11, a mixed solvent mainly composed of ethanol; the same shall apply hereinafter), silicate 40 (manufactured by Tama Chemical Industry Co., Ltd. 3.70 g of a mixture of ethoxysilane and its hydrolysis condensate, solid content concentration (SiO ₂ conversion: 40% by mass) and 6.00 g of the scaly silica particle dispersion (a) were added and stirred for 30 minutes. To this, a mixed solution of 3.55 g of ion exchange water and 0.06 g of an aqueous nitric acid solution (nitric acid concentration: 61 mass%) was added and stirred for 60 minutes. To this, 0.09 g of porous spherical silica particles (manufactured by Nissan Chemical Industries, Lightstar (registered trademark) LA-S23A, solid content concentration (SiO ₂ conversion): 23 mass%)) was added and stirred for 15 minutes. A base liquid (b) having a solid content concentration (SiO ₂ conversion) of 4.1% by mass was prepared. Incidentally, SiO ₂ in terms of solid concentration is a solid content concentration when all Si of Silicate 40 was converted to SiO _2.

(Preparation of silane compound solution (c))
While stirring 3.76 g of denatured ethanol, a mixed solution of 0.37 g of ion-exchanged water and 0.01 g of an aqueous nitric acid solution (nitric acid concentration: 61% by mass) was added and stirred for 5 minutes. 0.54 g of 1,6-bis (trimethoxysilyl) hexane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-3066, solid content concentration (in terms of SiO ₂ ): 37% by mass) is added, and it is kept at 60 ° C. for 15 minutes in a water bath. The mixture was stirred to prepare a silane compound solution (c) having a solid content concentration (SiO ₂ conversion) of 4.3% by mass.

(Preparation of coating solution)
While stirring the base solution (b), the silane compound solution (c) was added and stirred for 60 minutes. To this, 51.09 g of denatured ethanol was added and stirred at room temperature for 30 minutes to obtain a coating solution having a solid content concentration (SiO ₂ conversion) of 2.0 mass%.

(Manufacture of glass plate with antiglare film)
As a glass plate, soda lime glass (Asahi Glass Co., Ltd., FL 1.1, size: 300 mm × 300 mm, thickness: 1.1 mm) was prepared. The surface of the glass plate was washed with sodium bicarbonate water, rinsed with ion exchange water, and dried.

The glass plate was preheated in a preheating furnace (Isuzu Seisakusho, VTR-115). With the surface temperature of the glass plate kept at 80 ° C., the coating solution is applied to the surface of the glass plate under the conditions of spray pressure: 0.4 MPa, nozzle moving speed: 750 mm / min, spray pitch: 22 mm, and finally The coating was applied by a spraying method so that the formed antiglare film had a coating surface number (number of overcoating) of 60 ° specular gloss as shown in Table 1.
A 6-axis coating robot (manufactured by Kawasaki Robotics, JF-5) was used for application by the spray method. As the nozzle, a VAU nozzle (manufactured by Spraying System Japan) was used.

The pH of the electrolytically reduced water produced with an alkali ion water conditioner was measured at 23 ° C. ± 2. Specifically, it measured as follows using the pH meter (Horiba Ltd. make, D-22, electrode type 9615). The pH meter was calibrated with pH standard solutions (4.01, 6.86, 9.18). The electrolytic reduced water to be measured was put in a beaker, put in a water bath set at 23 ± 2 ° C., and waited until the measured temperature was reached. When the electrolytically reduced water reached the measurement temperature, pH measurement was performed.
The glass plate with a coating film was placed on a dedicated jig, immersed in electrolytic reduction water together with the jig, taken out after 3 minutes, and washed with ion exchange water for about 30 seconds. After washing, ion exchange water on the surface of the glass plate with the coating film was blown off with an air gun.

  Then, it heat-cured for 30 minutes at 450 degreeC in air | atmosphere, and obtained the glass plate with an anti-glare film. The evaluation results are shown in Table 1.

[Examples 2 to 19]
Using the alkaline aqueous solution shown in Table 1, dipping and firing were performed under the conditions shown in Table 1, and the antiglare film finally formed was coated so that the 60 ° specular glossiness was the value shown in Table 1. A glass plate with an antiglare function was obtained in the same manner as in Example 1 except that the number of surfaces (number of times of overcoating) was set. The evaluation results are shown in Table 1.

In Examples 1 to 17, in which the coating film was baked at 300 to 550 ° C. after contacting the alkaline aqueous solution having a pH of 10 to 12.5 with the coating film, the antiglare effect and the wear resistance were high, and cracks and coloring were observed. An article having a suppressed antiglare film could be produced.
In Examples 18 to 22 where the coating film was baked at 400 to 550 ° C. without bringing the coating film into contact with an alkaline aqueous solution having a pH of 10 to 12.5, cracks and coloring were observed in the antiglare film.
In Example 23 in which the coating film was baked at 300 ° C. without bringing the coating film into contact with an alkaline aqueous solution having a pH of 10 to 12.5, the antiglare film was colored and the wear resistance was insufficient. .
Example 24: Although the coating film was baked at 450 ° C. after contacting an aqueous alkali solution having a pH of 10 to 12.5 with the coating film, the 60 ° specular gloss was high (ie, the antiglare film was thin). In No. 1, cracking and coloring of the antiglare film were suppressed, and although the abrasion resistance was good, no antiglare effect was observed.
In Example 25, in which the coating film was baked at 450 ° C. after contacting the coating film with an alkaline aqueous solution having a pH of 9.5, cracks and coloring were observed in the antiglare film.

  The article with an antiglare film of the present invention can be used on an image display device (liquid crystal display, organic EL display, plasma display, etc.) provided in various devices (TV, personal computer, smartphone, mobile phone, etc.). This is useful for suppressing a decrease in visibility due to the reflection of light. Moreover, it can be used suitably also for articles | goods (protection board for solar cell modules etc.) other than an image display apparatus.

10 Article with antiglare film 12 Base material 14 Antiglare film

Claims (8)

An article having an antiglare film on the surface of a substrate,
The haze of the article is 15% or more,
The 60 ° specular gloss on the surface of the antiglare film is 25% or less,
An article with an antiglare film, wherein the arithmetic average roughness Ra of the surface of the antiglare film is 0.17 μm or more. A method for producing an article having the antiglare film according to claim 1,
A method for producing an article with an antiglare film, comprising the following steps (i) to (iii):
(I) The process of apply | coating the coating liquid containing a matrix precursor (A), an inorganic particle (B), and a liquid medium (C) to a base material, and forming a coating film.
(Ii) A step of bringing the coating film into contact with an alkaline aqueous solution having a pH of 10 to 12.5 after the step (i).
(Iii) The process of baking the said coating film and forming an anti-glare film after the said process (ii).   The manufacturing method of the articles | goods with an anti-glare film of Claim 2 in which the said coating liquid further contains an acid catalyst (D).   The method for producing an article with an antiglare film according to claim 2 or 3, wherein the alkaline aqueous solution is electrolytically reduced water.   The manufacturing method of the articles | goods with an anti-glare film as described in any one of Claims 2-4 whose baking temperature in the said process (iii) is 200-480 degreeC.   The manufacturing method of the article | item with an anti-glare film as described in any one of Claims 2-5 whose said base material is aluminosilicate glass.   The manufacturing method of the article | item with an anti-glare film as described in any one of Claims 2-6 whose said base material is glass which has a curved surface. An image display device main body for displaying an image;
An article with an antiglare film according to claim 1 or an article with an antiglare film obtained by the production method according to any one of claims 2 to 7, provided on the viewing side of the image display device main body. An image display device comprising:

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