JP2017072624A - 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 which has an anti-glare film formed by coating and baking a coating liquid containing a silica precursor and which is less susceptible to having cracks and peeling of the anti-glare film even when the film is thick, and to provide a manufacturing method for the same and an image display device that offers good visibility.SOLUTION: Provided is an article 10 having an anti-glare film 14 formed on a surface of a base material 12, where the anti-glare film 14 is obtained by coating the base material 12 with a coating liquid containing a silica precursor (A), scale-like particles (B), and a liquid medium (C) and baking it. The coating liquid contains, as the silica precursor (A), at least either or both of a silane compound (A1) having a hydrocarbon group bonded to a silicon atom and a hydrolyzable group, and a hydrolysis condensate thereof.SELECTED DRAWING: Figure 1

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 liquid containing a silica precursor such as a hydrolysis condensate of alkoxysilane is applied to a substrate and baked (Patent Documents 1 and 2, etc.).
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 film thickness of the antiglare film is increased, the internal stress increases, and cracks and film peeling occur in the antiglare film.

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

  The present invention is an article having an antiglare film formed by applying and baking a coating liquid containing a silica precursor, and the antiglare film is prevented from being cracked or peeled off even when the film thickness is large. An article with a film, a manufacturing method thereof, and an image display device with good visibility are provided.

  The article with an antiglare film of the present invention is an article having an antiglare film on the surface of a substrate, and the antiglare film comprises a silica precursor (A), scaly particles (B), a liquid medium ( C) is applied to a substrate and baked, and the coating liquid contains, as the silica precursor (A), hydrocarbon groups bonded to silicon atoms and hydrolyzability. It includes at least one or both of a silane compound (A1) having a group and a hydrolysis-condensation product thereof.

The 60 ° specular gloss on the surface of the antiglare film is preferably 20% or less.
The total ratio 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 (A) is in terms of SiO ₂ ). .) Is preferably 5 to 30% by mass.
The ratio of the scale-like particles (B) is 5 to 35% by mass in the solid content (100% by mass) in the coating solution (however, the silica precursor (A) is converted to SiO ₂ ). Is preferred.

The silane compound (A1) is preferably a compound represented by the following formula (I).
R _3-p L _p Si-Q-SiL _p R _3-p (I)
However, Q is a divalent hydrocarbon group (-O-, -S-, -CO- and -NR'- (where R 'is a hydrogen atom or a monovalent hydrocarbon group between carbon atoms). ), L may be a hydrolyzable group, and R may be a hydrogen atom or a monovalent hydrocarbon group. , P is an integer of 1 to 3.

It is preferable that the silica precursor (A) further includes one or both of alkoxysilane (however, excluding the silane compound (A1)) and a hydrolysis condensate thereof.
The scaly particles (B) are preferably scaly silica particles.
The base material may be chemically tempered glass.
The substrate may be aluminosilicate glass.
The substrate may be a glass having a curved surface.

  The method for producing an article with an antiglare film according to the present invention is a method for producing an article having an antiglare film on the surface of a substrate, the silica precursor (A), the scaly particles (B), and a liquid medium. (C) is applied to a substrate, and is fired to form an antiglare film, and the coating liquid is a hydrocarbon bonded to silicon atoms as the silica precursor (A). It includes at least one or both of a silane compound (A1) having a group and a hydrolyzable group and a hydrolysis-condensation product thereof.

  The image display device of the present invention comprises 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.

The article with an antiglare film of the present invention is an article having an antiglare film formed by applying and baking a coating liquid containing a silica precursor, and the antiglare film is cracked or peeled off even if the film thickness is large. Is suppressed.
According to the method for producing an article with an antiglare film of the present invention, even if a thick antiglare film is formed by a method of applying and baking a coating solution containing a silica precursor, the antiglare film is cracked or peeled off. Is unlikely to occur.
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 “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).
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.

<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 preferably 15% or more, more preferably 15 to 45%, and still more preferably 18 to 35%. 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 glass, metal, resin, silicon, wood, and paper.
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 includes a silica precursor (A), scaly particles (B), and a liquid medium (C), and if necessary, other particles (D) other than scaly particles (B), In a matrix mainly composed of silica, which is obtained by applying a coating liquid which may contain a known additive (E) to a substrate and baking it, and derived from the silica precursor (A) Scale-like particles (B) are present. The coating liquid contains at least one or both of a silane compound (A1) having a hydrocarbon group bonded to a silicon atom and a hydrolyzable group and a hydrolysis condensate thereof as a silica precursor (A).

  The 60 ° specular gloss on the surface of the antiglare film is preferably 20% or less, more preferably 17% or less, and even more preferably 15% or less. The 60 ° specular gloss on the surface of the antiglare film is an index of the antiglare effect. If the 60 ° specular gloss is 20% or less, the antiglare effect is sufficiently exhibited.

  The arithmetic average roughness Ra of the surface of the antiglare film is preferably 0.17 μm or more, more preferably 0.17 to 0.40 μm, and further preferably 0.20 to 0.35 μm. 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 0.40 μm or less, a decrease in image contrast is sufficiently suppressed.

<Method for producing article with antiglare film>
In the method for producing an article with an antiglare film of the present invention, a coating solution containing a silica precursor (A), scaly particles (B), and a liquid medium (C) is applied to a substrate and baked to prevent it. A step of forming a dazzling film. 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.

(Coating solution)
The coating solution contains a silica precursor (A), scaly particles (B), and a liquid medium (C), and if necessary, other particles (D) other than scaly particles (B), known The additive (E) may be included. The coating liquid contains at least one or both of a silane compound (A1) having a hydrocarbon group bonded to a silicon atom and a hydrolyzable group and a hydrolysis condensate thereof as a silica precursor (A).

The proportion of the silica precursor (A) (in terms of SiO ₂₎ had a solid content (100 mass%) in the coating solution (provided that a silica precursor (A) is a SiO ₂ conversion.) Among the 35 to 90 mass % Is preferable, and 50 to 88% by mass is more preferable. When the proportion of the silica precursor (A) is 35% by mass or more, sufficient adhesion strength with the substrate can be obtained. If the ratio of the silica precursor (A) is 90% by mass or less, cracks and film peeling of the antiglare film can be sufficiently suppressed even if the film thickness is large.

The total ratio 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 (A) is in terms of SiO ₂ ). ) Is preferably 5 to 30% by mass, more preferably 7 to 20% by mass. When the total ratio of the silane compound (A1) and its hydrolysis condensate is 5% by mass or more, cracks and film peeling of 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 ratio of the scale-like particles (B) is preferably 5 to 35% by mass in the solid content (100% by mass) in the coating solution (however, the silica precursor (A) is converted to SiO ₂ ). -30 mass% is more preferable. When the ratio of the scale-like particles (B) is 5% by mass or more, cracks and peeling of the antiglare film can be sufficiently suppressed even if the film thickness is large. When the ratio of the scale-like particles (B) is 35% by mass or less, sufficient wear resistance can be obtained.

When other particles (D) are included, the ratio of the other particles (D) is the solid content (100% by mass) in the coating solution (however, the silica precursor (A) is converted to SiO ₂ ). 0.5-5 mass% is preferable and 1-3 mass% is more preferable. If the proportion of other particles (D) is 0.5% by mass or more, 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. Therefore, the antiglare effect is sufficiently exhibited. When the ratio of the other particles (D) is 5% by mass or less, sufficient wear resistance 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 liquid includes, for example, a solution containing one or both of the silane compound (A1) and its hydrolysis condensate, a dispersion of scaly particles (B), and, if necessary, the silane compound (A1) and It can prepare by mixing the solution of other silica precursors (A2) other than the hydrolysis-condensation product, and the dispersion liquid of other particles (D).
In the case where a hydrolyzed condensate of tetraalkoxysilane is used as the other silica precursor (A2), a solution of tetraalkoxysilane from the point that an antiglare film having desired performance can be produced with high reproducibility, or After mixing the solution of the mixture of tetraalkoxysilane and its hydrolysis condensate and the dispersion of scale-like particles (B), the tetraalkoxysilane is hydrolyzed and condensed in the presence of scale-like particles (B). It is preferable.

(Silica precursor (A))
The silica precursor (A) includes at least one or both of a silane compound (A1) having a hydrocarbon group and a hydrolyzable group bonded to a silicon atom, and a hydrolysis condensate thereof. The silica precursor (A) 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 and film peeling of the antiglare film are 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, since it is easily available and even if the film thickness is large, cracks and film peeling of the antiglare film are sufficiently suppressed. More preferred is an alkyl group.

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 carried out using 4 times or more moles of water of the alkoxysilane and an acid or alkali as a catalyst. Examples of the acid 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). Examples of the alkali include ammonia, sodium hydroxide, potassium hydroxide and the like. The catalyst is preferably an acid from the viewpoint of long-term storage stability of the alkoxysilane hydrolysis condensate.

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

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

  Examples of the scaly particles (B) include scaly silica particles, scaly alumina particles, scaly titania, scaly zirconia, and the like. 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. When the amorphous silica particles are included, the denseness of the antiglare film to be formed may be reduced, and cracks and film peeling 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, (i) a method in which silica hydrosol is solidified in a spherical shape in a liquid medium such as petroleum, (ii) 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 (ii) 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 (ii) 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.

(Liquid medium (C))
The liquid medium (C) is a solvent that dissolves the silica precursor (A), and is a dispersion medium that disperses the scaly particles (B) and other particles (D).

  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 the alkoxysilane in the silica 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 silica precursor (A), alcohols are preferable, and methanol, ethanol, isopropyl alcohol, and butanol are particularly preferable.

(Other particles (D))
Examples of the other particles (D) include spherical silica particles, rod-like silica particles, and acicular silica particles. As other particles (D), 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 exhibited. In view of the above, spherical silica particles are preferable, and porous spherical silica particles are more preferable.

  The average particle diameter of the other particles (D) is preferably 0.3 to 2 μm, and more preferably 0.5 to 1.5 μm. If the average particle diameter of the other particles (D) is 0.3 μm or more, the antiglare effect is sufficiently exhibited. When the average particle diameter of the other particles (D) 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.

(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.

(Baking method)
The baking may be performed simultaneously with the application by heating the substrate when the application solution is applied to the substrate, or may be performed by heating the coating film after the application solution is applied to the substrate.
The firing temperature is preferably 30 ° C. or higher. For example, when the substrate is glass, 100 to 750 ° C. is more preferable, and 200 to 480 ° C. is more preferable.

(Mechanism of action)
In the article with an antiglare film of the present invention and the method for producing the same described above, either one of the silane compound (A1) having a hydrocarbon group and a hydrolyzable group bonded to a silicon atom, and a hydrolysis condensate thereof. Alternatively, since a coating solution containing both and scale-like particles (B) is applied to a substrate and baked to form an antiglare film, hydrocarbons derived from the silane compound (A1) in the antiglare film Groups and scaly particles (B) are present. Therefore, even if the film thickness of the antiglare film formed by applying and baking the coating liquid containing the silica precursor (A) is increased, the antiglare film is present due to the presence of hydrocarbon groups and scaly particles (B). Shrinkage is reduced and internal stress is reduced. As a result, even if the film thickness is large, cracks and film peeling 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, since the article with the antiglare film of the present invention in which cracks and film peeling of the antiglare film are suppressed is provided on the viewing side of the image display device main body, Good properties.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by the following description.
Examples 1 to 11 are examples, and examples 12 to 20 are comparative examples.

(60 ° specular gloss)
The 60 ° specular glossiness of the surface of the antiglare film is determined by using a gloss meter (Nippon Denshoku Industries Co., Ltd.) (Manufactured by PG-3D), and measured at approximately the center of the antiglare film by the method described in JIS Z 8741: 1997.

(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).

(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).

(Film peeling)
The anti-glare film peeling was evaluated according to the following criteria for images observed at 200 times using an optical microscope.
X: There are many film peelings.
Δ: There is a slight film peeling.
○: No film peeling is observed.

(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 difference (absolute value) in 60 ° specular gloss of the surface of the antiglare film before and after the eraser was reciprocated 200 times was determined. The smaller the difference in 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.

(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 34.33 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. 4.20 g of a mixture of ethoxysilane and its hydrolysis condensate, solid content concentration (SiO ₂ conversion: 40% by mass) and 2.00 g of scaly silica particle dispersion (a) were added and stirred for 30 minutes. To this, a mixed solution of 3.55 g of ion-exchanged water and 0.06 g of an aqueous nitric acid solution (nitric acid concentration: 61% by 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 the mixture is added 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 the spray method with the number of coated surfaces (number of overcoating) such that the antiglare film to be formed had a 60 ° specular gloss as shown in Table 2.
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.
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 2.

[Examples 2 to 20]
Except having changed into the composition shown in Table 1, it carried out similarly to Example 1, and prepared the coating liquid of Examples 2-20.
Example 1 except that the coating solution was changed and the number of coated surfaces (number of overcoatings) was changed so that the 60 ° specular gloss of the antiglare film finally formed became the value shown in Table 2. Similarly, a glass plate with an antiglare function was obtained. The evaluation results are shown in Table 2.
In Example 10, 1,2-bis (triethoxysilyl) ethane (manufactured by AMAX Co., SIB1817) was used as the silane compound (A1).

  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 (12)

An article having an antiglare film on the surface of a substrate,
The antiglare film is obtained by applying a coating liquid containing a silica precursor (A), scaly particles (B), and a liquid medium (C) to a substrate, followed by firing.
The coating solution contains at least one or both of 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 (A). Article with antiglare film.   The article with an antiglare film according to claim 1, wherein the 60 ° specular gloss on the surface of the antiglare film is 20% or less. 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 (A) is in terms of SiO ₂ ) .), The article with an antiglare film according to claim 1 or 2, wherein the content is 5 to 30% by mass. The ratio of the scaly particles (B) is 5 to 35% by mass in the solid content (100% by mass) in the coating solution (however, the silica precursor (A) is converted to SiO ₂ ). The article with an antiglare film according to any one of claims 1 to 3. The article with an antiglare film according to any one of claims 1 to 4, wherein the silane compound (A1) is a compound represented by the following formula (I).
R _3-p L _p Si-Q-SiL _p R _3-p (I)
However,
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). And may have one or a combination of two or more selected.)
L is a hydrolyzable group,
R is a hydrogen atom or a monovalent hydrocarbon group,
p is an integer of 1 to 3.   The said silica precursor (A) contains any one or both of alkoxysilane (however, except the said silane compound (A1)) and its hydrolysis condensate, The any one of Claims 1-5. An article with an antiglare film as described in 1.   The article with an antiglare film according to any one of claims 1 to 6, wherein the scaly particles (B) are scaly silica particles.   The article with an antiglare film according to any one of claims 1 to 7, wherein the base material is chemically strengthened glass.   The article with an antiglare film according to any one of claims 1 to 8, wherein the substrate is an aluminosilicate glass.   The article with an antiglare film according to any one of claims 1 to 9, wherein the substrate is a glass having a curved surface. A method for producing an article having an antiglare film on the surface of a substrate,
A step of applying a coating liquid containing a silica precursor (A), scaly particles (B), and a liquid medium (C) to a substrate and baking to form an antiglare film;
The coating solution contains at least one or both of 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 (A). A method for producing an article with an antiglare film. An image display device main body for displaying an image;
An image display device comprising: the article with an antiglare film according to any one of claims 1 to 10 provided on a viewing side of the image display device main body.

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