JP2014214063A - Silica-based porous film, article having silica-based porous film, and method for producing the same article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silica-based porous film that has good antireflection performance and antifouling property and is produced in a simple production process, to provide an article having the silica-based porous film and to provide a method for producing the article.SOLUTION: The silica-based porous film has a plurality of holes in a matrix composed mainly of silica, has a refractive index in the range of 1.10-1.38. The holes include a hole having a diameter of not less than 20 nm. The number of holes having a diameter of not less than 20 nm opening to the outermost surface of the film is 13/10nmor less and the outermost surface has a water contact angle of 70° or more.

Description

  The present invention relates to a silica-based porous membrane, an article with a silica-based porous membrane, and a method for producing the same.

Articles having an antireflection film on the surface of a transparent substrate such as a glass plate are used as cover members for solar cells, various displays and their front plates, various window glasses, touch panel cover members, and the like.
One of antireflection films used for glass plates and the like is a silica-based porous film. Since the silica-based porous film has pores in a matrix containing silica as a main component, the refractive index is lower than that in the case where there are no pores.
Various methods have been proposed as a method for producing a silica-based porous membrane. As one of them, there is a method of applying and heat-treating a coating liquid containing a silica precursor such as alkoxysilane and pore forming particles (for example, Patent Document 1). In this method, the pore-forming particles are removed simultaneously with the formation of the matrix by the heat treatment or after the formation of the matrix, thereby forming the pores. This method has an advantage that the process is simple and the size and porosity of the pores can be controlled by the size and blending amount of the pore-forming particles used as a template.

The antireflection film is disposed on the outermost layer of the article because of its function. For this reason, the antireflection film is required to have antifouling properties (that dirt is difficult to adhere and can be easily removed even if it adheres).
However, since the above-mentioned silica-based porous film has a large number of open holes and irregularities on the outermost surface, there is a problem that dirt easily adheres and it is difficult to remove the adhered dirt.
For example, in the manufacturing process of the solar cell, a step of bonding the cover member and the solar cell with a sealing material is performed. When a silica-based porous film is used as the antireflection film, there is a problem that EVA, which is a sealing material, penetrates into the silica-based porous film in the manufacturing process and the antireflection performance is lowered. In addition, the soaked EVA is difficult to peel off from the silica-based porous film, and even after peeling, the color of the silica-based porous film where the EVA has soaked becomes different from the other parts. There are also problems such as.

As a countermeasure against the problems in the above manufacturing process and the like, a protective film is provided on a silica-based porous film. However, this method is expensive and time-consuming.
As a method for imparting antifouling properties, there is a method of applying a fluorine-based water-repellent coating agent. When this method is applied to a silica-based porous membrane, the antifouling property against oil and fat stains and EVA can be easily improved at a lower cost than when a protective film is provided. However, in this case, there is a concern that the applied coating agent soaks into the silica-based porous film, closes the pores, and reduces the antireflection performance. Furthermore, tempered glass is used from the viewpoint of safety when used for solar cell applications, etc., and as a technique for strengthening the glass, the glass is heated to 600 to 700 ° C. and then rapidly cooled by blowing air onto the surface. When tempering is performed by a chemical strengthening method in which ion exchange is performed on a glass surface by impregnating a glass containing sodium ions with a molten salt containing 300 to 500 ° C. containing potassium ions, The water repellent coating agent is thermally decomposed. Therefore, in order to impart antifouling properties, it is necessary to apply the water-repellent coating agent again after the glass strengthening step, which makes the manufacturing process complicated.

Special table 2010-509175

  The present invention has been made in view of the above circumstances, and provides a silica-based porous film having good antireflection performance and antifouling property, and having a simple manufacturing process, an article including the same, and a method for manufacturing the same. For the purpose.

The present invention has the following aspects.
[1] A silica-based porous film having a plurality of pores in a matrix mainly composed of silica,
The refractive index is in the range of 1.10 to 1.38;
As the holes, including holes having a diameter of 20 nm or more,
The number of holes having a diameter of 20 nm or more opened on the outermost surface is 13/10 ⁶ nm ² or less,
A silica-based porous membrane having a water contact angle of 70 ° or more on the outermost surface.
[2] The silica-based porous membrane according to [1], wherein an average value of the distance from the outermost surface to the uppermost portion of the pores existing below the outermost surface is 10 to 80 nm.
[3] The silica-based porous membrane according to [1] or [2], wherein the average diameter of the pores is 15 to 100 nm.
[4] The silica-based porous membrane according to any one of [1] to [3], wherein pores having a diameter of 20 nm or more existing inside the silica-based porous membrane are independent pores.
[5] The silica-based porous membrane according to any one of [1] to [4], wherein the outermost surface has an arithmetic average roughness (Sa) of 3.0 nm or less.
[6] An article with a silica-based porous film having the silica-based porous film according to any one of [1] to [5] on the surface of the article.

[7] A method for producing an article with a silica-based porous film having a silica-based porous film having a plurality of pores in a matrix mainly composed of silica on the surface of the article,
Applying a coating liquid containing a matrix precursor, particles removable from the matrix, and a liquid medium to the surface of the article and heat-treating the coating liquid;
The matrix precursor contains the following compound (A), the following compound (B1), and the following compound (B2), and satisfies the following condition (I):
The content of the compound (A) is 5% by mass or more based on the total solid content contained in the coating solution,
The method for producing an article with a silica-based porous film, wherein the particles have an average primary particle diameter of 20 to 130 nm.
Compound (A): Hydrolyzate and partial condensate of silane compound (1) represented by the following general formula (1), and silane compound (1) and silane compound represented by the following general formula (2) ( 2) at least one compound selected from the group consisting of co-hydrolysates and partial condensates, and at least a structure derived from a silane compound in which n in the general formula (1) is 2. Compound.
Y _n SiX _4-n (1)
SiX ₄ (2)
[Wherein, X represents a hydrolyzable group, Y represents a non-hydrolyzable group whose dielectric constant of Y-OH is 50 F / m or less, and n represents an integer of 1 to 3. ]
Compound (B1): At least one compound selected from the group consisting of a silane compound in which n in the general formula (1) is 1 or 3, its hydrolysis and partial condensate.
Compound (B2): At least one compound selected from the group consisting of the silane compound (2), a hydrolyzate and a partial condensate thereof.
Condition (I): The compound (A) with respect to the total amount of the number of moles of the silane compound (2) forming the compound (A) and the number of moles of the silane compound (2) forming the compound (B2). The ratio [(1) / (2)] of the total amount of the number of moles of the silane compound (1) to be formed and the number of moles of the silane compound (1) to form the compound (B1) is 0.1 to 25. It is in the range of 0.

[8] The method for producing an article with a silica-based porous film according to [7], wherein the compound (B1) has a group having a double bond as Y.
[9] The mass ratio [matrix precursor / particles] of the content of the matrix precursor (in terms of SiO ₂ ) to the content of the particles in the coating solution is within a range of 0.7 to 6.0. A method for producing an article with a silica-based porous film according to [7] or [8].
[10] The method for producing an article with a silica-based porous film according to any one of [7] to [9], wherein the particles are made of carbon or an organic polymer.
[11] The silica-based porous material according to [10], wherein the organic polymer comprises a homopolymer or a copolymer of at least one monomer selected from the group consisting of methyl methacrylate, styrene, acrylonitrile, butadiene, and isoprene. A method for producing an article with a membrane.

  According to the present invention, it is possible to provide a silica-based porous film having good antireflection performance and antifouling property and having a simple manufacturing process, an article provided with the same, and a method for manufacturing the same.

It is sectional drawing which shows one Embodiment of the articles | goods with a silica type porous membrane in this invention. It is a schematic sectional drawing which illustrates typically the structure of the silica type porous membrane in the article with a silica type porous membrane shown in FIG. It is sectional drawing which shows one Embodiment of the articles | goods with a silica type porous membrane in this invention. 2 is a SEM photograph ((a) surface, (b) cross section) of a glass plate with a silica-based porous film obtained in Example 1. FIG. 4 is a SEM photograph ((a) surface, (b) cross section) of a glass plate with a silica-based porous film obtained in Example 2. FIG. It is a SEM photograph ((a) surface, (b) cross section) of the glass plate with a silica type porous membrane obtained in Example 10. FIG. It is a SEM photograph ((a) surface, (b) cross section) of the glass plate with a silica type porous membrane obtained in Example 13. It is a SEM photograph ((a) surface, (b) cross section) of the glass plate with a silica type porous membrane obtained in Example 14. It is a SEM photograph ((a) surface, (b) cross section) of the glass plate with a silica type porous membrane obtained in Example 15. It is a SEM photograph ((a) surface, (b) cross section) of the glass plate with a silica type porous membrane obtained in Example 16.

Hereinafter, the present invention will be described with reference to exemplary embodiments.
<Article with Silica-based Porous Membrane of First Embodiment>
FIG. 1 is a cross-sectional view showing a first embodiment of an article with a silica-based porous film having the silica-based porous film of the present invention on the surface of the article.
The article 10 with a silica-based porous film of the present embodiment has a glass plate 12 and a silica-based porous film 14 formed on the surface of the glass plate 12.

(Glass plate 12)
Examples of the glass include soda lime glass, borosilicate glass, aluminosilicate glass, and alkali-free glass.
The glass plate 12 may be a smooth glass plate formed by a float method or the like, or may be a template glass having irregularities on the surface. Further, not only flat glass but also glass having a curved surface shape may be used.
The thickness of the glass plate 12 is not particularly limited. For example, glass having a thickness of 0.2 to 10 mm can be used. The thinner the thickness, the lower the light absorption, which is preferable for the purpose of improving the transmittance.

When the glass plate 12 is an architectural or vehicle window glass, soda lime glass having the following composition is preferred.
In mass percentage display based on oxide,
SiO _2: 65~75%,
Al ₂ O _3: 0~10%,
CaO: 5 to 15%,
MgO: 0 to 15%,
Na ₂ O: 10~20%,
K ₂ O: 0 to 3%,
Li ₂ O: 0 to 5%,
Fe ₂ O ₃ : 0 to 3%,
TiO _2: 0~5%,
CeO ₂ : 0 to 3%,
BaO: 0 to 5%,
SrO: 0 to 5%,
B ₂ O _3: 0~15%,
ZnO: 0 to 5%,
ZrO ₂ : 0 to 5%,
SnO ₂ : 0 to 3%,
SO ₃ : 0 to 0.5%.

When the glass plate 12 is an alkali free glass, what has the following composition is preferable.
In mass percentage display based on oxide,
SiO _2: 39~70%,
Al ₂ O ₃ : 3 to 25%,
B ₂ O _3: 1~30%,
MgO: 0 to 10%,
CaO: 0 to 17%,
SrO: 0 to 20%,
BaO: 0 to 30%.

When the glass plate 12 is a mixed alkali glass, those having the following composition are preferred.
In mass percentage display based on oxide,
SiO _2: 50~75%,
Al ₂ O _3: 0~15%,
MgO + CaO + SrO + BaO + ZnO: 6 to 24%,
_{Na 2 O + K 2 O:} 6~24%, including.

  When the glass plate 12 is a solar cell cover glass, a satin-patterned template glass with an uneven surface is preferable. As the template glass, soda lime glass (white plate glass) having a lower iron component ratio (high transparency) than soda lime glass (blue plate glass) used for ordinary window glass or the like is preferable.

(Silica-based porous film 14)
FIG. 2 is a schematic cross-sectional view schematically illustrating the configuration of the silica-based porous film 14.
The silica-based porous film 14 has a plurality of pores 22 having a diameter of 20 nm or more in a matrix 21 mainly composed of silica.
The silica-based porous film 14 has a relatively low refractive index (reflectance) because the matrix 21 is mainly composed of silica. Moreover, it is excellent in chemical stability, adhesiveness with the glass plate 12, abrasion resistance, and the like. Furthermore, by having the holes 22 in the matrix 21, the refractive index is lower than when the holes 22 are not provided.
The silica-based porous film 14 may have pores with a diameter of less than 20 nm (not shown) in the matrix 21.

That the matrix 21 has silica as a main component means that the proportion of silica is 90% by mass or more in the matrix (100% by mass).
The matrix 21 is preferably made of silica substantially. Being substantially composed of silica means that it is composed of only silica except for inevitable impurities (for example, a structure derived from a non-hydrolyzable group Y included in a silane compound (1) described later).
The matrix 21 may contain a small amount of components other than silica. The components include Li, B, C, N, F, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, and Sr. , Y, Zr, Nb, Ru, Pd, Ag, In, Sn, Hf, Ta, W, Pt, Au, Bi, and compounds such as one or more ions and oxides selected from lanthanoid elements .
The matrix 21 may include not only two-dimensionally polymerized matrix components but also three-dimensionally polymerized nanoparticles. Examples of the composition of the nanoparticles include Al ₂ O ₃ , SiO ₂ , SnO ₂ , TiO ₂ , ZnO, and ZrO ₂ . The size of the nanoparticles is preferably 1 to 100 nm. The shape of the nanoparticles is not particularly limited, and examples thereof include a spherical shape, a needle shape, a hollow shape, a sheet shape, and a square shape.

A plurality of pores 22 having a diameter of 20 nm or more exist in the silica-based porous film 14. Thereby, the excellent antireflection performance is obtained.
The diameter of the pores is measured from an image obtained by observing a cross section of the silica-based porous film 14 using a scanning electron microscope (hereinafter also referred to as SEM). When the shape of the hole in the image is not a perfect circle, the average value of the minor axis and the major axis is taken as the diameter.

The average diameter of the pores contained in the matrix 21 (hereinafter also referred to as “average pore diameter”) is preferably 15 to 100 nm, and more preferably 20 to 80 nm. When the average pore diameter is 15 nm or more, sufficient antireflection performance as an antireflection film is obtained, and when it is 100 nm or less, the durability and light transmittance of the silica-based porous film 14 are good.
The average pore diameter can be obtained by measuring the diameter of 100 pores from an image obtained by observing the cross section of the silica-based porous film 14 using SEM and calculating the average value thereof.

The silica-based porous film 14 has an outermost surface dense layer 14b on the outermost surface (surface opposite to the glass plate 12 side) 14a side. The outermost surface dense layer 14b is a region that substantially does not include the holes 22 having a diameter of 20 nm or more.
The term “substantially free” means that the number of pores 22 (open holes) opened in the outermost surface 14a of the silica-based porous film 14 (hereinafter also referred to as “the number of outermost open holes”) is 13/10 ⁶ nm. ² or less. The number of holes on the outermost surface is preferably 10/10 ⁶ nm ² or less, particularly preferably 0. That is, it is particularly preferable that the outermost surface dense layer 14b is a region where there are no holes 22 having a diameter of 20 nm or more.
The number of open holes on the outermost surface is the number of openings having a diameter of 20 nm or more existing in an area of 1000 nm × 1000 nm from an image obtained by observing the outermost surface 14a of the silica-based porous film 14 with an SEM. It is calculated by measuring. When the shape of the opening in the image is not a perfect circle, the average value of the minor axis and the major axis is taken as the diameter.

The number of open pores on the outermost surface of the silica-based porous film 14 is 13/10 ⁶ nm ² or less, and the absence of large-diameter pores on the outermost surface contributes to the improvement of the antifouling property. By having almost no large-diameter pores, dirt hardly penetrates into the pores inside the silica-based porous film 14, and the attached dirt is easy to remove.
The fact that there are almost no large-diameter holes on the outermost surface also contributes to improved durability.
When conventional porous silica membranes contain pores with a diameter of 20 nm or more, the pores communicate with each other and many open pores are formed on the membrane surface. When performed, the porous structure is broken and the antireflection performance tends to be lowered. For example, when a conventional silica-based porous film is directly formed on the surface of the glass plate 12, the porous structure at the portion in contact with the glass plate 12 under wet heat conditions is broken by the influence of alkali, and the antireflection performance is lowered.
On the other hand, in the present invention, since the number of outermost surface open holes is small, the matrix 21 has excellent durability even though the holes 21 having a diameter of 20 nm or more are included in the matrix 21. For example, even when the silica-based porous film 14 is formed directly on the surface of the glass plate 12 and placed under wet heat conditions, the porous structure is maintained over a long period of time, and the antireflection performance is unlikely to deteriorate. It also has excellent wear resistance. The effect of suppressing the deterioration of the antireflection performance under wet heat conditions is that the outermost surface dense layer 14b allows moisture in the outside air to pass through the silica-based porous film 14 and reach the glass plate 12 to generate alkali. It is thought that it can be suppressed.
Thus, the antifouling property and durability (moisture heat resistance, wear resistance, etc.) are improved, so that the usefulness of the silica-based porous film 14 as an antireflection film is improved.
In addition, the influence which the void | hole less than 20 nm in diameter has on durability is small. Therefore, the silica-based porous film 14 may have pores having a diameter of less than 20 nm (not shown) in the outermost surface dense layer 14b and the matrix 21 in other regions.

The outermost surface 14a of the silica-based porous film 14, that is, the surface of the outermost dense layer 14b, has a water contact angle of 70 ° or more, preferably 75 ° or more, particularly preferably 80 ° or more.
The number of holes 22 (the number of outermost surface open holes) opened on the outermost surface 14a of the silica-based porous film 14 is 13/10 ⁶ nm ² or less, and the water contact angle of the outermost surface 14a is 70 ° or more. As a result, hydrophobic stains such as oil stains and EVA are less likely to adhere to the outermost surface 14a, and even if they adhere, they are easy to remove and exhibit excellent antifouling properties. For example, in the case of a transparent substrate for solar cells, especially cover glass, even if a sealing material (such as EVA) melted in the manufacturing process of the solar cell module adheres to the outermost surface 14a, the sealing material can be easily peeled off. Discoloration due to the soaked sealing material hardly occurs.
The upper limit of the water contact angle of the outermost surface 14a is not particularly limited in terms of antifouling properties, but is usually 120 ° or less from the viewpoint of the surface energy of the Y group that the compound (A) has.
The method for measuring the water contact angle is as shown in the examples described later.
The water contact angle of the outermost surface 14a can be adjusted by the material (for example, the compound (A) mentioned by the manufacturing method mentioned later) which comprises the outermost surface dense layer 14b.

In the present invention, the pores 22 having a diameter of 20 nm or more existing inside the silica-based porous membrane 14 are preferably independent holes, not connecting holes.
The term “independent pores” refers to granular pores that exist independently in the matrix. It is preferable that the pores 22 existing inside the silica-based porous membrane 14 are independent pores, so that water vapor or the like hardly penetrates the interface between the glass and the membrane and is excellent in heat and moisture resistance.
For example, as shown in the manufacturing method described later, a step of applying a coating liquid containing a matrix precursor, particles (C) that can be removed from the matrix, and a liquid medium (D) to the surface of the article and heat-treating it. When the silica-based porous film 14 is formed through the process, organic polymer nanoparticles are used as the particles (C), and the pores 22 existing inside the silica-based porous film obtained by pyrolyzing the particles are independent pores. And a plurality of holes 22 are present one by one.
On the other hand, in the conventional silica-based porous film obtained by a method of laminating inorganic nanoparticles, which is a general method for producing a silica-based porous film, voids between the particles form connection holes. In the case where the inside of the film is composed of connecting holes, even if a dense layer is formed on the outermost surface, moisture and the like are likely to permeate into the interface between the glass and the film, so that the moisture and heat resistance tends to be insufficient.

The average film thickness (hereinafter also referred to as “the outermost surface dense layer average film thickness”) d of the outermost surface dense layer 14b is preferably 10 to 80 nm, and more preferably 13 to 60 nm. When the outermost surface dense layer average film thickness d is 10 nm or more, the effect of suppressing moisture in the outside air from reaching the glass is good. If the average thickness d of the outermost surface dense layer is 80 nm or less, the refractive index of the entire film can be kept low, and the antireflection performance is good.
The outermost surface dense layer average film thickness indicates an average value of the distance from the outermost surface 14a of the silica-based porous film 14 to the uppermost part of the pores 22 having a diameter of 20 nm or more existing under the outermost surface 14a.
The measuring method of the average thickness of the outermost surface dense layer is as shown in the examples described later.

  The ratio of the outermost surface dense layer average film thickness d (nm) to the average total film thickness (nm) of the silica-based porous film 14 takes into consideration the desired outermost surface dense layer average film thickness d, average total film thickness, and the like. Although it can set suitably and it is not specifically limited, 8 to 40% is preferable and 10 to 30% is more preferable.

40-300 nm is preferable and, as for the average total film thickness of the silica type porous membrane 14, 80-200 nm is more preferable. When the average total film thickness of the silica-based porous film 14 is 40 nm or more, light interference occurs in the visible light region, and antireflection performance is exhibited. If the average total film thickness of the silica-based porous film 14 is 300 nm or less, the film can be formed without generating cracks.
The method for measuring the average total film thickness is as shown in the examples described later.

The refractive index of the silica-based porous film 14 is in the range of 1.10 to 1.38, preferably in the range of 1.15 to 1.35. If the refractive index of the silica-based porous film 14 is 1.38 or less, sufficient pores 22 are present in the silica-based porous film 14, and the reflectance of the silica-based porous film 14 is sufficiently low, Excellent anti-reflection performance. If the refractive index of the silica type porous membrane 14 is 1.10 or more, the porosity of the silica type porous membrane 14 will not become too high, and durability will improve.
The refractive index of the silica-based porous film 14 is an average value of the entire silica-based porous film 14 and is measured by an ellipsometer. The specific measurement method is as shown in the examples described later. In the silica-based porous film 14, the outermost surface dense layer and other regions have different refractive indexes.

The arithmetic average roughness (Sa) of the outermost surface 14a of the silica-based porous membrane 14 is preferably 3.0 nm or less, and more preferably 2.5 nm or less.
If the outermost surface 14a has smoothness with an arithmetic average roughness (Sa) of 3.0 nm or less, durability, such as wear resistance, is improved. In addition, the antifouling property is improved such that the dirt is difficult to adhere and the attached dirt is easy to remove, and the usefulness as an antireflection film is improved. A film having many open pores on the surface or a film obtained by using core-shell type particles or hollow particles is not preferable because of high arithmetic average roughness (Sa).
The method of measuring the arithmetic average roughness (Sa) is as shown in the examples described later.

The average reflectance (hereinafter also referred to as “average reflectance (5 ° incidence)”) of light having a wavelength of 400 to 1100 nm incident on the surface of the silica-based porous film 14 at an incident angle of 5 ° is 2.0% or less. It is preferable that it is 1.7% or less. If the average reflectance (5 ° incidence) of the silica-based porous film 14 is 2.0% or less, the antireflection performance required for a solar cell cover glass or the like is sufficiently satisfied.
The incident angle in this specification is an angle formed by the incident direction of light and the normal line of the surface of the silica-based porous film.
The measuring method of the average reflectance (5 ° incidence) is as shown in the examples described later.

The average transmittance of light having a wavelength of 400 to 1100 nm that is incident on the surface of the article 10 with a silica-based porous membrane on the silica-based porous membrane 14 side at an incident angle of 0 ° (hereinafter also referred to as “average transmittance (0 ° incidence)”) .) Is preferably 94.0% or more, more preferably 94.5% or more. If the average transmittance (0 ° incidence) of the article 10 with a silica-based porous film is 94.0% or more, the light transmittance required for a cover glass of a solar cell is sufficiently satisfied.
The average transmittance of an article with a silica-based porous film using another light-transmitting substrate instead of the glass plate 12 in the article with a silica-based porous film 10 may be 94.0% or more as described above. preferable.
The measuring method of the average transmittance (0 ° incidence) is as shown in the examples described later.

<The manufacturing method of the article with a silica type porous membrane of a first embodiment>
The article 10 with a silica-based porous film can be produced by forming a silica-based porous film 14 on a glass plate 12.
In the formation of the silica-based porous film 14, first, a matrix precursor shown below, particles that can be removed from the matrix (hereinafter, also referred to as particles (C)), and a liquid medium (hereinafter, liquid medium (D) The coating liquid containing the above is applied to the surface of the glass plate 12 and heat-treated.
The matrix 21 is formed from the matrix precursor by heat-treating the coating film of the coating solution.
If the particles (C) can be removed by heat treatment, the particles (C) are removed by the heat treatment, and the silica-based porous film 14 is formed. Specifically, when the particles (C) are composed of a thermally decomposable material (for example, a thermally decomposable organic polymer), the heat treatment temperature when forming the matrix 21 is the thermal decomposition temperature of the thermally decomposable material. By setting the above temperature, the particles (C) are vaporized, pass through the fine pores in the matrix 21 and are released to the outside of the matrix 21, and the silica-based porous film 14 is formed. The heat treatment for forming the matrix 21 may be performed at a temperature lower than the thermal decomposition temperature, and after the film formation, the heat treatment may be performed again at a temperature equal to or higher than the thermal decomposition temperature.
When the particles (C) are not removed by the heat treatment, the silica-based porous film 14 is subjected to a removal treatment corresponding to the material constituting the particles (C) before or after the formation of the matrix 21 by the heat treatment. Can be formed.

[Matrix precursor]
The matrix precursor contains the following compound (A), compound (B1), and compound (B2). The compounds (A), (B1), and (B2) are derived from one or both of the following silane compounds (1) and (2).

The silane compound (1) is a compound represented by the following general formula (1).
Y _n SiX _4-n (1)
[Wherein, X represents a hydrolyzable group, Y represents a non-hydrolyzable group whose dielectric constant of Y-OH is 50 F / m or less, and n represents an integer of 1 to 3. ]

In formula (1), X represents a hydrolyzable group. The hydrolyzable group is a group that can convert a Si—X group into a Si—OH group by hydrolysis.
Examples of X include halogen atoms (for example, chlorine atoms), alkoxy groups, acyloxy groups, aminoxy groups, amide groups, ketoximate groups, hydroxyl groups, epoxy groups, glycidyl groups, isocyanate groups, and the like. An alkoxy group is particularly preferable because the hydrolysis polycondensation reaction can be easily controlled. As an alkoxy group, a C1-C4 alkoxy group is preferable and a methoxy group or an ethoxy group is more preferable.

Y represents a non-hydrolyzable group in which the dielectric constant of Y—OH is 50 F / m or less.
The non-hydrolyzable group is a functional group whose structure does not change under the condition that the Si—X group becomes a Si—OH group by hydrolysis.
A literature value may be used for the dielectric constant of Y—OH, but it can be measured by the following measurement method.
The dielectric constant of Y-OH is determined by applying an electric field to the sample by a bridge circuit using a network analyzer (manufactured by Agilent Technologies, PNA microwave vector network analyzer) in accordance with JIS-R1627. And the phase was calculated from the measured values.

Examples of Y include a hydrocarbon group that may be substituted with a fluorine atom. The hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group containing an unsaturated bond such as a double bond.
Specific examples of Y include a perfluoropolyether group, a perfluoroalkyl group, an alkyl group, an aryl group (such as a phenyl group), a group having a double bond (hereinafter also referred to as a group (Y1)), and the like. . Examples of the group (Y1) include a vinyl group, an acryloyl group, an acryloyloxyalkyl group, a methacryloyl group, a methacryloyloxyalkyl group, and a styryl group.

When n is 1 or 2, the plurality of Xs that the silane compound (1) has may be the same or different. The same group is preferable in terms of availability, ease of controlling the hydrolysis reaction, and the like.
When n is 2 or 3, the plurality of Y possessed by the silane compound (1) may be the same or different. The same group is preferable in terms of availability, ease of controlling the hydrolysis reaction, and the like.

  Specific examples of the silane compound (1) include, for example, monoalkyltrialkoxysilane (methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, etc.) , Dialkyl dialkoxysilane (dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane, etc.), trialkylmonoalkoxysilane (trimethylmethoxysilane, trimethylethoxysilane) Triethylmethoxysilane, triethylethoxysilane, tripropylmethoxysilane, tripropylethoxysilane, etc.), monoaryltrialkoxysila (Phenyltrimethoxysilane, phenyltriethoxysilane, etc.), diaryl dialkoxysilane (diphenyldimethoxysilane, diphenyldiethoxysilane, etc.), triarylmonoalkoxysilane (triphenylmethoxysilane, triphenylethoxysilane, etc.), perfluoropolyether Examples thereof include alkoxysilanes having a group (perfluoropolyether triethoxysilane and the like), alkoxysilanes having a perfluoroalkyl group (perfluoroethyltriethoxysilane and the like), and the like. These may be used alone or in combination of two or more.

The silane compound (2) is a compound represented by the following general formula (2).
SiX ₄ (2)
[Wherein, X represents a hydrolyzable group. ]

In the formula (2), examples of X include the same as X in the formula (1).
The four Xs that the silane compound (2) has may be the same or different. The same group is preferable in terms of availability, ease of controlling the hydrolysis reaction, and the like.
Specific examples of the silane compound (2) include, for example, tetraalkoxysilane (tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, etc.).

{Compound (A)}
The compound (A) is selected from the group consisting of the hydrolyzate and partial condensate of the silane compound (1), and the cohydrolyzate and partial condensate of the silane compound (1) and the silane compound (2). And a compound having a structure derived from at least the silane compound (1-2).
That is, the silane compound (1) forming the compound (A) includes at least the silane compound (1-2).
Of the above, the silane compound (1-2) is preferably a dialkyl dialkoxy silane or a diaryl dialkoxy silane, more preferably a dialkyl dialkoxy silane, from the viewpoint of having a large amount of X and a sufficient amount of X for condensation. .
The silane compound (1) forming the compound (A) may be only the silane compound (1-2), and the silane compound (1-2) and the silane in which n in the general formula (1) is 1 or 3 It may be a mixture with a compound.
20 mol% or more is preferable and, as for the ratio of the silane compound (1-2), in the total amount of the silane compound (1) which forms a compound (A), it is more preferable that it is 40 mol% or more. The upper limit is not particularly limited, and may be 100%.

The hydrolyzate and partial condensate of the silane compound (1), and the cohydrolyzate and partial condensate of the silane compound (1) and the silane compound (2) can be obtained by ordinary methods.
For example, a hydrolyzate or a partial condensate can be obtained by adding and mixing water to the silane compound (1) or to the silane compound (1) and the silane compound (2). The silane compounds (1) and (2) are highly reactive, and a hydrolysis reaction or a partial condensation reaction can proceed even by adding water.
At this time, it is preferable to add a catalyst together with water. An acid or an alkali can be used as the 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 hydrolyzate or partial condensate to be produced.
The obtained reaction solution is usually used as it is or after appropriately diluted to prepare the coating solution. Therefore, the catalyst used for hydrolysis is preferably one that does not hinder the dispersion of the particles (C).
5-80 degreeC is preferable and the temperature at the time of performing a hydrolysis and a partial polycondensation reaction has more preferable 10-70 degreeC. If it is 5 degreeC or more, a hydrolysis polycondensation reaction will fully advance, and if it is 80 degrees C or less, hydrolysis polycondensation reaction control is easy.
The smaller the number of Y, the easier the hydrolysis and condensation reaction proceeds, and the silane compound (2) is more easily condensed than the silane compound (1). Therefore, when the silane compound (1) and the silane compound (2) are co-hydrolyzed, the reaction solution contains only a co-hydrolyzate or partial condensate of the silane compound (1) and the silane compound (2). However, a hydrolyzate or partial condensate of the silane compound (2), that is, the compound (B2) is also produced. This reaction solution can be used as it is for preparing a coating solution.

In the compound (A), X may remain unreacted. The content of X remaining in the compound (A) is an uncondensed compound represented by the general formula (1) because the compound (A) maintains a low dielectric constant and easily forms the outermost layer in the coating film. The total molar amount of X contained in the body is preferably less than 29 mol%, and more preferably less than 15 mol%.
Content of X in a compound (A) can be adjusted with conditions, such as the value of n of a compound (A), the reaction temperature at the time of a hydrolysis reaction and a condensation reaction, reaction time, water addition amount, catalyst addition amount.

The average molecular weight of the compound (A) is preferably in the range of 200 to 2000, and more preferably in the range of 300 to 1500. If the average molecular weight is 200 or more, volatilization of unreacted components is suppressed, and if it is 2000 or less, sufficient transparency can be secured.
The average molecular weight can be controlled by the amount of water added, the reaction temperature, the content of the precursor (silane compound (1) or silane compounds (1) and (2)), and the like.
The average molecular weight is a polystyrene-reduced weight average molecular weight measured by gel permeation chromatography (GPC).

{Compound (B1)}
The compound (B1) is at least one compound selected from a silane compound in which n in the general formula (1) is 1 or 3, a hydrolyzate thereof, and a partial condensate thereof.
The silane compound (1-2) is not included in the silane compound (1) forming the compound (B1).
The silane compound (1) forming the compound (B1) may be only a silane compound in which n is 1 (hereinafter also referred to as silane compound (1-1)), or a silane compound in which n is 3 (hereinafter referred to as silane). Compound (1-3) only) or a mixture of the silane compound (1-1) and the silane compound (1-3).
As a silane compound (1) which forms a compound (B1), a silane compound (1-1) is preferable.
Of the above, the silane compound (1-1) is preferably monoalkyltrialkoxysilane or monoaryltrialkoxysilane, because it is easily available and does not generate an inert gas during thermal decomposition. Is more preferable.
The hydrolyzate and partial condensate of the silane compound (1) can be obtained by a conventional method as described above.

As the compound (B1), a compound having a group (Y1) (a group having a double bond) as Y is particularly preferable since it is excellent in the durability improving effect. The group (Y1) is considered to contribute to improvement in durability by forming a carbon chain between Si atoms by a double bond cleavage condensation reaction and increasing flexibility. Examples of the group (Y1) include the same groups as described above.
The compound (B1) may have a group other than the group (Y1) as Y.

The average molecular weight of the compound (B1) is preferably in the range of 200 to 2000, and more preferably in the range of 300 to 1500. If the average molecular weight is 200 or more, volatilization of unreacted components is suppressed, and if it is 2000 or less, sufficient transparency can be secured.
The average molecular weight can be controlled by the amount of water added, the reaction temperature, the content of precursors (silane compounds (1-1), (1-3)), and the like.

{Compound (B2)}
The compound (B2) is at least one compound selected from the silane compound (2), a hydrolyzate thereof, and a partial condensate thereof.
The hydrolyzate and partial condensate of the silane compound (2) can be obtained by a conventional method as described above.
The silane compound (1) and the silane compound (2) may be mixed in advance to perform a cohydrolysis polycondensation reaction. In this case, the obtained reaction solution contains a hydrolyzate or partial condensate of the silane compound (1) and a hydrolyzate or partial condensate of the silane compound (2). This reaction solution can be used as it is for preparing a coating solution.
The compound (B2) is preferably a silane compound (2) using tetraalkoxysilane in which the alkoxy group has 1 or 2 carbon atoms.

The average molecular weight of the compound (B2) is preferably in the range of 200 to 2000, and more preferably in the range of 300 to 1500. If the average molecular weight is 200 or more, volatilization of unreacted components is suppressed, and if it is 2000 or less, sufficient transparency can be secured.
The average molecular weight can be controlled by the amount of water added, the reaction temperature, the content of the precursor (silane compound (2)), and the like.

{Contents of compounds (A), (B1), (B2)}
In the coating solution, the content of the compound (A) is 5% by mass or more, preferably 5 to 70% by mass, and more preferably 10 to 51% by mass with respect to the total solid content contained in the coating solution.
The content is a solid content in terms of SiO ₂ (solid content when all Si of the compound (A) contained in the coating liquid is converted to SiO ₂ ).
By setting the content of the compound (A) in the coating solution to 5% by mass or more, the outermost surface dense layer 14b is formed with a sufficient thickness, and the number of open pores on the outermost surface of the silica-based porous film 12 is 13 / It can be 10 ⁶ nm ² or less. Moreover, the smoothness of the outermost surface 14a is high, and arithmetic mean roughness Sa can be 3.0 nm or less. Further, the hydrophobicity of the outermost surface of the silica-based porous film 14 is sufficiently high (for example, the water contact angle is 70 ° or more).
Antifouling properties are improved such that the number of pores on the outermost surface is small and the smoothness and hydrophobicity of the outermost surface are high, making it difficult for dirt to adhere and facilitating removal of attached dirt. Moreover, the outstanding moisture resistance is acquired because there are few outermost surface open | release holes. Moreover, wear resistance is also improved because the smoothness of the outermost surface is high.

The contents of the compounds (A), (B1), and (B2) in the matrix precursor satisfy the following condition (I).
Condition (I): Total amount of the number of moles of the silane compound (2) forming the compound (A) and the number of moles of the silane compound (2) forming the compound (B2) [total number of silane compounds (2) The total amount of the number of moles of the silane compound (1) forming the compound (A) and the number of moles of the silane compound (1) forming the compound (B1) with respect to the number of moles] [total number of silane compounds (1) The [number of moles] ratio [(1) / (2)] is in the range of 0.1 to 25.0. (1) / (2) is preferably 0.1 to 10.0, and more preferably 0.5 to 5.0.
By setting the value of (1) / (2) to 25.0 or less, and further setting the content of the compound (A) to 70% by mass or less, sufficient antireflection performance and durability can be obtained. When the value of (1) / (2) exceeds 25.0, since the amount of the silane compound (2) is too small, the thickness of the lower layer region where the pores 22 are present becomes thin, and the antireflection performance is also improved. There is a possibility that the degree of condensation of the matrix precursor is low and the durability is insufficient.

  The coating solution may contain a matrix precursor other than the compounds (A), (B1), and (B2) as long as the effects of the present invention are not impaired. Examples of matrix precursors other than the compounds (A), (B1), and (B2) include monoalkyltrialkoxysilanes that do not correspond to the compound (B1) (methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyl) Triethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, etc.), trialkylmonoalkoxysilane (trimethylmethoxysilane, trimethylethoxysilane, triethylmethoxysilane, triethylethoxysilane, tripropylmethoxysilane, tripropylethoxysilane, etc.), Monoaryltrialkoxysilane (phenyltrimethoxysilane, phenyltriethoxysilane, etc.), diaryl dialkoxysilane (diphenyldimethoxysilane, diphenyldiethoxy) Silane), triarylmonoalkoxysilane (triphenylmethoxysilane, triphenylethoxysilane, etc.), alkoxysilane having a perfluoropolyether group (perfluoropolyethertriethoxysilane, etc.), alkoxysilane having a perfluoroalkyl group (perfluoroethyl) In addition to triethoxysilane, etc., silicone oil, silicone oligomer, silicone resin, water glass and the like can be mentioned.

The content of the matrix precursor in the coating liquid is a coating liquid is not particularly limited as long as it is within the range of possible application, the total amount of the coating liquid with respect to (100 mass%), as calculated as SiO ₂ solid content concentration, 0. 2-20 mass% is preferable and 0.5-15 mass% is more preferable. If it is 0.2% by mass or more, hydrolysis polycondensation reaction proceeds sufficiently, and if it is 20% by mass or less, hydrolysis polycondensation reaction control is easy and long-term storage stability is good.
Incidentally, SiO ₂ in terms of solids are solids when all the Si matrix precursor contained in the coating liquid was converted into SiO _2.

[Particle (C)]
The particles (C) are particles that can be removed from the matrix, for example, particles that can be removed by heat treatment, particles that can be removed by plasma treatment, particles that can be removed by solvent immersion, particles that can be removed by acid or alkali immersion, Examples thereof include particles that can be removed by light irradiation.
Since heat treatment is required to form the outermost surface dense layer 14b, the particles (C) are preferably particles that can be removed by heat treatment, but before or after the heat treatment, plasma treatment, solvent immersion, acid or alkali immersion, Alternatively, the outermost surface dense layer 14b may be formed by heat treatment after removal by light irradiation.

Examples of particles that can be removed by heat treatment include particles made of a thermally decomposable material or a thermally sublimable material.
100-800 degreeC is preferable and, as for the thermal decomposition temperature of a thermally decomposable material, 200-700 degreeC is more preferable.
Examples of the thermally decomposable material include carbon, organic polymer, and surfactant micelle. Among these, carbon or an organic polymer is preferable from the viewpoint of stability over time.
The thermal decomposition temperature of carbon in air is about 500 ° C. The thermal decomposition temperature of the organic polymer in air varies depending on the type and molecular weight of the organic polymer, but is generally about 200 to 600 ° C. The thermal decomposition temperature of the organic polymer can be measured by differential thermal-thermogravimetric simultaneous measurement (TG-DTA).
The particles that can be removed by the heat treatment may be core-shell particles coated with an inorganic oxide such as SiO ₂ that is not removed by the heat treatment. When the thickness of the shell is thick, irregularities derived from particles are likely to be formed on the film surface, and the shell thickness is preferably 5 nm or less because insufficient wear resistance and dirt are likely to adhere. From the viewpoint of antireflection performance, it is more preferable that a component that cannot be removed by heating is not included.

The organic polymer is not particularly limited as long as synthesis of nanoparticles having a desired particle size can be obtained, but (meth) acrylic monomers, styrene monomers, diene monomers, imide monomers, amide monomers. Homopolymers or copolymers of monomers selected from the group consisting of (hereinafter also referred to as “specific monomer group”) are preferred.
Acrylic monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, (meth ) Pentyl acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, ( (Meth) acrylic acid dodecyl, (meth) acrylic acid phenyl, (meth) acrylic acid methoxyethyl, (meth) acrylic acid ethoxyethyl, (meth) acrylic acid propoxyethyl, (meth) acrylic acid butoxyethyl, (meth) acrylic acid Ethoxypropyl, diethylaminoethyl (meth) acrylate , Dialkylaminoalkyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide, diacetone acrylamide, glycidyl (meth) acrylate, ethylene glycol diacrylate, diethyl glycol diacrylate, triethylene glycol Diacrylic acid ester, polyethylene glycol diacrylic acid ester, dipropylene glycol diacrylic acid ester, tripropylene glycol diacrylic acid ester, ethylene glycol dimethacrylic acid ester, diethylene glycol dimethacrylic acid ester, triethylene glycol dimethacrylic acid ester , Polyethylene glycol diacrylate, propylene glycol dimethacrylate , Dimethacrylates of dipropylene glycol, dimethacrylate ester of tripropylene glycol.
Examples of styrene monomers include alkyl styrene; styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, octyl styrene, fluorostyrene, chloro. Examples include styrene, bromostyrene, dibromostyrene, chloromethylstyrene, nitrostyrene, acetylstyrene, methoxystyrene, α-methylstyrene, vinyltoluene, sodium p-styrenesulfonate, and the like.
Examples of the diene monomer include butadiene, isoprene, cyclopentadiene, 1,3-pentadiene, dicyclopentadiene, and the like.
Examples of the imide monomers include maleimide, N-methylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide, 6-aminohexyl succinimide, 2-aminoethyl succinimide, and the like.
Examples of amide monomers include acrylamide derivatives such as acrylamide and N-methylacrylamide, allylamine derivatives such as N, N-dimethylacrylamide and N, N-dimethylaminopropylacrylamide, and acrylamide derivatives such as acrylamide and N-methylacrylamide. And aminostyrenes such as N-aminostyrene.

When the organic polymer is a copolymer of a monomer selected from the specific monomer group, the copolymer may be a copolymer of two or more monomers selected from the specific monomer group. In addition, at least one selected from the specific monomer group and at least one monomer other than the monomer selected from the specific monomer group may be copolymerized.
Examples of the other monomers include divinylbenzene, vinyl acetate, vinylpyridine, acrylic acid, methacrylic acid, tetrahydrophthalic acid, maleic acid, itaconic acid, fumaric acid, citraconic acid, crotonic acid, isocrotonic acid, norbornene dicarboxylic acid, methylene Malonic acid, monoethyl itaconate, monobutyl itaconate, monomethyl maleate, monoethyl maleate, monobutyl maleate, monopropyl maleate, monooctyl maleate, carboxyalkyl vinyl ether, carboxyalkyl vinyl ester, bicyclo [2,2,1] Hept-2-ene-5,6-dicarboxylic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic acid Acrylic acid such as water, aminoethyl (meth) acrylate, propylaminoethyl (meth) acrylate, dimethylaminoethyl methacrylate, aminopropyl (meth) acrylate, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate or the like Alkyl ester derivatives of methacrylic acid, vinylamine derivatives such as N-vinyldiethylamine, N-acetylvinylamine, allylamine, methacrylamine, N-methylacrylamine, N, N-dimethylacrylamide, N, N-dimethylaminopropylacrylamide Allylamine derivatives such as phenyl (meth) acrylate, benzyl (meth) acrylate, vinyl salicylate, vinylidene chloride, vinyl chlorohexanecarboxylate, 2-chloroacrylate Chill, 2-chloroethyl methacrylate, acrylonitrile, methacrylonitrile, methacrylamide, N-methylol methacrylamide, N-methoxyethyl methacrylamide, N-butoxymethyl methacrylamide, aminoethyl (meth) acrylate, (meth) Propylaminoethyl acrylate, dimethylaminoethyl methacrylate, aminopropyl (meth) acrylate, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, alkyl ester derivatives of acrylic acid or methacrylic acid, N-vinyldiethylamine, N- Vinylamine derivatives such as acetylvinylamine, allylamine, methacrylamine, N-methylacrylamine, N, N-dimethylacrylamide, N, N-dimethylaminopropylamine Allylamine derivatives such as acrylamide, acrylamide derivatives such as acrylamide and N-methylacrylamide, p-aminostyrene, N-methylol (meth) acrylamide and diacetone acrylamide, 6-aminohexyl succinimide, 2-aminoethyl succinic acid Imides, glycidyl methacrylate, mono and diglycidyl esters of maleic acid, mono and diglycidyl esters of fumaric acid, mono and diglycidyl esters of crotonic acid, mono and diglycidyl esters of tetrahydrophthalic acid, mono and glycidyl esters of itaconic acid Mono and diglycidyl esters of butenetricarboxylic acid, mono and diglycidyl esters of citraconic acid, mono and glycidyl esters of allyl succinic acid, and the like Ricidyl ester, alkyl glycidyl ester of p-styrene carboxylic acid, allyl glycidyl ether, glycidyl ether acrylate, glycidyl methacrylate, -2-ethyl glycidyl acrylate, 2-ethyl glycidyl methacrylate Tail, 2-methylallyl glycidyl ether, styrene-p-glycidyl ether, glycidyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, acrylic acid or methacrylic acid Monoester of acid and polypropylene glycol or polyethylene glycol, adduct of lactones and 2-hydroxyethyl (meth) acrylate, trifluoromethyl methyl (meth) acrylate, (meth) acrylic 2-trifluoromethyl ethyl oxalate, (meth) acrylic acid-2-perfluoromethyl ethyl, (meth) acrylic acid-2-perfluoroethyl-2-perfluorobutyl ethyl, (meth) acrylic acid 2-perfluoroethyl, perfluoromethyl (meth) acrylate, dipa-fluoromethyl methyl (meth) acrylate, vinyl acetate, vinyl propionate, vinyl n-butyrate, vinyl isobutyrate, vinyl pivalate, capron Vinyl acetate, vinyl persate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pt-butyl benzoate, vinyl salicylate, vinylidene chloride, vinyl chlorohexanecarboxylate, 2-chloroethyl acrylate, methacrylic acid 2-chloroethyl, 3-chloro-2-hydroxypropyl methacrylate , Β-methacryloyloxyethyl hydrogen phthalate, phenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di ( (Meth) acrylate, diethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,1,1 -Trishydroxymethylethane diacrylate, 1,1,1-trishydroxymethylethane triacrylate, 1,1,1-trishydroxymethylprop N triacrylate, N-methylol acrylic amide and the like.
In the copolymer, the proportion of monomer units selected from the specific monomer group is preferably 80 mol% or more, particularly preferably 100 mol%, based on the total of all monomer units.

200-600 degreeC is preferable and, as for the thermal decomposition temperature of the said homopolymer or copolymer, 300-500 degreeC is more preferable.
As the organic polymer, in addition to the homopolymer or copolymer of the specific monomer group, polyethylene glycol, polypropylene glycol, polyisobutylene glycol, polyethylene oxide-polypropylene oxide diblock polymer, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock A polymer, polyvinyl alcohol, silicone or the like can also be used.

The particles that can be removed by the plasma treatment can be decomposed and removed by irradiating the film made of the matrix precursor and the particles (C) with plasma. Examples of the material of the particles include the organic polymers described above.
The particles that can be removed by immersion in the solvent can be dissolved and removed by immersing the film made of the matrix precursor and the particles (C) in the solvent. Examples of the material of the particles include diglyme, N, N-dimethylformamide, N, N-dimethylacetamide, ethyl acetate, ethyl acetoacetate, N-methyl-2-pyrrolidinone, 2-pyrrolidinone, 1,3-dimethyl- Polystyrene as soluble in solvents such as 2-imidazolidinone, dimethyl sulfoxide, toluene, xylene, benzene, trichlene, mineral spirits, benzol, xylol, γ-butyrolactone, tetrahydrofuran, methyl ethyl ketone, acetone, dichloromethane, chloroform, methylene chloride And polymethyl acrylate.
Particles that can be removed by acid or alkali immersion can be dissolved and removed by immersing a film made of the matrix precursor and particles (C) in acid or alkali. Examples of the material of the particles include zinc oxide, basic zinc carbonate, calcium carbonate and the like which can be dissolved in acids such as hydrochloric acid, nitric acid, and sulfuric acid. Zinc oxide etc. are mentioned as what melt | dissolves in alkalis, such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and ammonia.
Particles that can be removed by light irradiation can be removed by irradiating light (for example, ultraviolet rays, etc.) to the film composed of the matrix precursor and the particles (C) and photodissolving. Examples of the material of the particles include zinc oxide and cadmium sulfide.
When the particles (C) are removed by the plasma treatment, solvent immersion, acid or alkali immersion, or light irradiation, heat treatment is performed before and / or after the step of removing the particles (C) in order to form the outermost surface dense layer. It is preferable.

The particles (C) are preferably made of a thermally decomposable material in that the particles (C) can be removed simultaneously with the heat treatment when the matrix precursor is used as a matrix, and the production process becomes simple. Especially, it is preferable to consist of carbon or an organic polymer at the point of thermal decomposition temperature. That is, the particles (C) are preferably carbon particles or organic polymer particles.
As a carbon particle, a commercially available thing may be used and what was manufactured by the manufacturing method of a well-known carbon nanoparticle may be used.
As an organic polymer particle, a commercially available thing may be used and what was manufactured by the manufacturing method of a well-known organic polymer nanoparticle may be used. For example, a dispersion in which organic polymer nanoparticles are dispersed can be obtained by a known emulsion polymerization method. Specifically, an aqueous dispersion of organic polymer nanoparticles can be obtained by adding a monomer to water containing a surfactant, mixing to form micelles, and adding a polymerization initiator for polymerization. Moreover, you may use the organic polymer nanoparticle obtained by the soap free polymerization method which does not use surfactant.

The average primary particle diameter of the particles (C) is 20 to 130 nm, and preferably 30 to 100 nm. When the average primary particle diameters of the particles (C) is at 20nm or more, can form a silica-based porous membrane having pores with a diameter of 20nm, If it is 130nm or less, the number of outermost surface open pores ^13/10 6 nm It can be: Moreover, when the average primary particle diameter of the particles (C) is in the range of 20 to 130 nm, the average pore diameter is likely to be in the range of 15 to 100 nm.
The average primary particle size in this specification is 100 particles randomly selected from an image obtained by observation with a transmission electron microscope, the particle size of each particle is measured, and the particle size of 100 particles is determined. It is average.

As particle | grains (C), 1 type may be used independently and 2 or more types from which a material, an average primary particle diameter, etc. differ may be used together.
The content of the particles (C) in the coating solution is such that the mass ratio [matrix precursor / particles] of the content of the matrix precursor (in terms of SiO ₂ ) to the content of the particles (C) is 0.7 to 6. The amount is preferably in the range of 0.0, and more preferably in the range of 1.0 to 4.0.
If the matrix precursor / particle is 6.0 or less, the porosity in the silica-based porous film 14 is sufficiently high, and the refractive index of the silica-based porous film 14 is sufficiently low (for example, 1.38 or less). become. When the matrix precursor / particle is 0.7 or more, the porosity in the silica-based porous film 14 does not become too high, and the durability is excellent.

[Liquid medium (D)]
The liquid medium (D) is a liquid that dissolves the matrix precursor and disperses the particles (C), and may be a single liquid or a mixed liquid in which two or more liquids are mixed.
Since water is required for hydrolysis of the silane compounds (1) and (2), the liquid medium (D) preferably contains at least water.
Water and other liquids may be used in combination. Examples of the other liquid include alcohols (methanol, ethanol, isopropanol, butanol, diacetone alcohol, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), ethers (tetrahydrofuran, 1,4-dioxane, etc.). ), Cellosolves (methyl cellosolve, ethyl cellosolve, etc.), esters (methyl acetate, ethyl acetate, etc.), glycol ethers (ethylene glycol monoalkyl ether, etc.), nitrogen-containing compounds (N, N-dimethylacetamide, N, N -Dimethylformamide, N-methylpyrrolidone, etc.), sulfur-containing compounds (dimethylsulfoxide, etc.) and the like.
Among the other liquids, as the matrix precursor solvent, alcohols are preferable, and methanol, ethanol, and isopropanol are particularly preferable.
Among the other liquids, as the dispersion medium for the particles (C), any of alcohols, ketones, ethers, cellosolves, esters, glycol ethers, nitrogen-containing compounds, sulfur-containing compounds and the like may be used. Good.

The coating solution may contain components other than the matrix precursor and the particles (C) as long as the effects of the present invention are not impaired.
Examples of the other component include a curing catalyst (metal chelate, metal alcoholate, organotin, etc.) for improving the reactivity of the matrix precursor.

Examples of the method for preparing the coating liquid include a method of mixing a solution of a matrix precursor and a dispersion of particles (C), and a solution containing the compound (A) (hereinafter also referred to as precursor solution A). A method of mixing a solution containing compound (B1) and compound (B2) (hereinafter also referred to as precursor solution B) and a dispersion of particles (C) is preferable.
The precursor solution A can be prepared by subjecting the silane compound (1-2) to hydrolysis treatment with the silane compounds (1-1), (1-3), and (2) as necessary.
The precursor solution B can be prepared by hydrolyzing one or both of the silane compounds (1-1) and (1-3) and the silane compound (2).
More specifically, the preparation methods of the precursor solution B include the following methods (α) to (γ).
(Α) A method in which the silane compound (1) ((1-1) or (1-3)) and the compound (2) in the solution are hydrolyzed and then diluted with a solvent as necessary.
(Β) A solution of the silane compound (1) ((1-1) or (1-3)) after hydrolyzing the silane compound (2) in the solution (preferably after elapse of 1 hour or more after hydrolysis) And diluting with a solvent if necessary.
(Γ) A method of hydrolyzing the silane compound (2) in the solution, diluting with a solvent, and then adding a solution of the silane compound (1) ((1-1) or (1-3)).
Among these, the method (α) is preferable because the co-hydrolysis of the silane compound (1) and the silane compound (2) is efficiently performed.
When preparing a precursor solution A containing a co-hydrolyzate or partial condensate of silane compound (1) and silane compound (2), or a compound containing compound (B2) in addition to compound (A) In the preparation of the precursor solution B described above, it can be prepared in the same manner except that at least the silane compound (1-2) is used as the silane compound (1). It can also be prepared by the following method (δ).
(Δ) After hydrolyzing the silane compound (1) (including at least (1-2)) in the solution (preferably after 1 hour or more has passed since hydrolysis), the solution of the silane compound (2) is added. And then diluting with a solvent if necessary.

As a coating method of the coating liquid, known wet coating methods (spin coating method, spray 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) Method, flexo coat method, slit coat method, roll coat method, sponge coat method, etc.).
10-100 degreeC is preferable and, as for the liquid temperature at the time of application | coating of a coating liquid, 20-80 degreeC is more preferable.

What is necessary is just to determine the heat processing temperature suitably according to the glass plate 12, particle | grains (C), or a matrix precursor.
In order to use the matrix precursor as the matrix 21, heat treatment may be performed at 80 ° C. or higher, but 100 ° C. or higher is preferable, and 200 to 700 ° C. is more preferable. When the heat treatment temperature is 100 ° C. or higher, the matrix 21 is densified and the durability is improved. When the heat treatment temperature is 700 ° C. or lower, the alkali diffusion from the glass can be kept low, and the moisture resistance is good.
When the particles (C) are composed of a thermally decomposable material such as carbon or an organic polymer, and the particles (C) are removed by heat treatment, the heat treatment is performed at a temperature equal to or higher than the heat decomposition temperature of the thermally decomposable material. , Particles (C) can be removed. In this case, the heat treatment temperature is preferably (thermal decomposition temperature + 100 ° C.) or higher, more preferably (thermal decomposition temperature + 50 ° C.) or higher.
When the particles (C) are removed by heat treatment, heat treatment for using the matrix precursor as the matrix 21 may be performed at a temperature lower than the thermal decomposition temperature before the heat treatment.
It is preferable that the heat treatment also serves as a step of strengthening the glass. When using glass for solar cell applications, tempered glass is used from the viewpoint of safety. The tempered glass has a compressive stress on the surface, has a higher strength than a general float plate glass, and is excellent in safety because it becomes granular even when broken.
As a technique for strengthening the glass, a heat strengthening method in which the glass is heated to 600 to 700 ° C. and then rapidly cooled by blowing air onto the surface, and a glass containing sodium ions is melted at 300 to 500 ° C. containing potassium ions. The chemical strengthening method which ion-exchanges on the glass surface by impregnating with salt is mentioned.

When the particles (C) cannot be removed by the heat treatment, the particles (C) are removed by removal other than the heat treatment before or after the heat treatment.
Examples of the removal method other than the heat treatment include plasma treatment, solvent immersion, acid or alkali immersion, and light irradiation as mentioned in the description of the particles (C). Specifically, a method of irradiating a film comprising a matrix precursor and particles (C) with plasma, a method of immersing the film in a solvent, a method of immersing the film in an acid or an alkali, The method of irradiating etc. is mentioned.
In terms of simplicity in the manufacturing process, particles (C) are composed of a thermally decomposable material such as carbon and organic polymer, and the particles (C) are removed by heat treatment and at the same time the glass is further strengthened. It is preferable.

(Function and effect)
In the manufacturing method described above, the coating liquid is applied onto the article 10, preheated as necessary, heat-treated, and a series of steps of removing the particles (C) is performed once, whereby the pores 22 are obtained. Silica having a two-layer structure with different distribution states (the outermost surface dense layer 14b having no pores 22 having a diameter of 20 nm or more and a layer having pores 22 having a diameter of 20 nm or more on the glass substrate 12 side) The system porous membrane 14 can be formed.

In the production method of the present invention, it is important to use at least three kinds of compounds (A), (B1) and (B2) in combination as a matrix precursor.
As described above, the compounds (A), (B1), and (B2) are derived from one or both of the silane compounds (1) and (2), and the compounds (A) and (B1) are , Derived from the silane compound (1), containing Y (non-hydrolyzable group having a dielectric constant of Y-OH of 50 F / m or less), and the compound (B2) does not contain Y. Compounds (A) and (B1) differ in the value of n, the content of X, and consequently the content of Y.
Silane compound (1): a compound represented by the following general formula (1).
Silane compound (2): a compound represented by the following general formula (2).
Y _n SiX _4-n (1)
SiX ₄ (2)
[Wherein, X represents a hydrolyzable group, Y represents a non-hydrolyzable group whose dielectric constant of Y-OH is 50 F / m or less, and n represents an integer of 1 to 3. ]

Therefore, the compounds (A), (B1), and (B2) have different dielectric constants (polarities). Among these, the compound (B2) formed from the silane compound (2) has the largest dielectric constant. Further, in the compound (A) and the compound (B1), the compound (A) tends to have a lower dielectric constant as a whole (in the case of the silane compound (1-1) where n = 1, n = 2). This is because the number of Y is smaller than that in the case of the silane compound (1-2), and in the case of the silane compound (1-3) of n = 3, it is considered that they are present almost without condensation.
Originally, the dielectric constant of each of the compounds (A), (B1), and (B2), that is, the hydrolyzate (Y _n Si (OH) _{4 -n} , Si (OH) _{4 of} each of the silane compounds (1) and (2). ) And the dielectric constant of the partial condensate, but since it is difficult to measure the dielectric constant of the hydrolyzate and the partial condensate itself, the inventors have The model was applied and verified.
Specifically, the hydrolyzate and partial condensate of silane compound (1) (compounds (A) and (B1)) are Y—OH, the hydrolyzate and partial condensate of silane compound (2) (compound (B2)). )) Was selected as a similar compound. Most of the hydrolyzate of the silane compound (2) is Si (OH) ₄ , and its dielectric constant is close to HO—OH.
As a result, it was found that if the dielectric constant difference between HO—OH and Y—OH is large, a compound having a small dielectric constant is likely to float in the coating film, and as a result, the outermost surface dense layer 14b is likely to be formed.

The dielectric constant of HO—OH is 89.2 F / m. By having Y in Y—OH having a smaller dielectric constant than this, the interface free energy of the hydrolyzate or partial condensate of the silane compound (1) is the hydrolyzate (Si (OH)) of the silane compound (2). ₄ ) or lower than the interface free energy of the partial condensate.
When Y is a hydrocarbon group that may be substituted with a fluorine atom, as shown below, the longer the chain length of the hydrocarbon group, or the fluorine atom that replaces the hydrogen atom of the hydrocarbon group. The larger the number, the smaller the dielectric constant of Y—OH.
[Similar compound of silane compound (1) (Y—OH)]
CH ₃ -OH (methanol: permittivity 33.1F / m).
CH ₃ CH ₂ -OH (ethanol: permittivity 23.8F / m).
_{CH 3 (CH 2) 5 -OH} (1- hexanol dielectric constant 13.3F / m).
C ₆ H ₅ -OH (phenol: permittivity 2.9F / m).
CF ₃ CH ₂ -OH (trifluoroethanol: permittivity 2.1F / m).

Since the interface free energy of the hydrolyzate or partial condensate of the silane compound (1) is lower than the interface free energy of the hydrolyzate or partial condensate of the silane compound (2), the compounds (A) and (B1) And a coating solution containing (B2) is applied to the surface of an article such as a glass plate, the compounds (A) and (B1) having Y float up in the coating film, while having a non-hydrolyzable group Y. The compound (B2) not present hardly floats in the coating film. Further, the particles (C) having a certain average primary particle diameter are hardly floated. Therefore, a concentration gradient (local distribution) of the compounds (A), (B1), (B2) and particles (C) occurs in the coating film. Specifically, the compounds (A) and (B1) are unevenly distributed on the outermost surface side in the coating film, and accordingly, the compound (B2) and particles (C) are unevenly distributed on the article side in the coating film. become. In particular, as described above, the compound (A) tends to have a lower dielectric constant than the compound (B1) as a whole, and tends to be unevenly distributed on the outermost surface side (upper layer side).
Therefore, the coating film is heat-treated and the compounds (A), (B1) and (B2) are used as matrices, respectively, and a removal treatment corresponding to the material of the particles (C) is performed simultaneously with the heat treatment or before or after the heat treatment. By applying, the lower layer side becomes a region having pores 22 having a shape corresponding to the shape of the particles (C), and the upper layer side becomes a region having almost no pores 22 (outermost surface dense layer 14b). .

On the upper layer side (outermost surface dense layer 14b) and the lower layer side (region where pores 22 having a diameter of 20 nm or more are distributed) formed on the silica-based porous film 14 as described above, the composition of the matrix 21 is It is considered different. That is, the matrix 21 constituting the lower layer side is mainly composed of the heat-treated product of the compound (B2), and does not contain or contains very little structure derived from the non-hydrolyzable group Y. The matrix 21 constituting the upper layer side is mainly composed of a heat-treated product of the compound (A) or the compound (B1) and includes a structure derived from the non-hydrolyzable group Y of the silane compound (1).
In particular, the matrix 21 near the outermost surface 14a is mainly composed of a heat-treated product of the compound (A). Since compound (A) has a low X content, the matrix formed from compound (A) is more hydrophobic than the matrix formed from compound (B1) or compound (B2).

Therefore, when the coating solution contains the compound (A), the hydrophobicity of the silica-based porous film 14 to be formed becomes higher than when the coating solution does not contain the compound (A). For example, the water contact angle on the outermost surface is 70 ° or more. A certain silica-based porous film 14 can be formed. When the water contact angle on the outermost surface is 70 ° or more, the antifouling property is improved and the usefulness as an antireflection film is improved.
Moreover, when a coating liquid contains a compound (B1), durability with respect to abrasion etc. of the silica type porous membrane 14 formed will improve compared with the case where this is not included. The effect is particularly remarkable when the group (Y1) is contained. This is considered to be because a carbon chain is formed between Si atoms forming a matrix by performing a double bond cleavage polymerization reaction, and flexibility is increased.

In the production method, the outermost surface dense layer is formed depending on the content of the matrix precursor (compounds (A), (B1), (B2)) in the coating solution, the average primary particle diameter of the particles (C), and the like. The average film thickness d can be adjusted.
For example, in the matrix precursor, as the content ratio of the compound (A) and the compound (B1) increases (the content ratio of the compound (B2) decreases), the outermost surface dense layer average film thickness d tends to increase. Moreover, the larger the average primary particle diameter of the particles (C), the more difficult the particles (C) to float to the outermost surface side, and the outermost surface dense layer average film thickness d tends to increase.

In the production method, the average film thickness d of the outermost surface dense layer 14b can be adjusted by the difference in dielectric constant between the compound (B2) and the compound (A). For example, when X (hydrolyzable group) of the silane compound (2) is an alkoxy group, the smaller the number of carbon atoms in the alkoxy group, the faster the hydrolysis proceeds and the easier the conversion to Si—OH. As a result, the dielectric constant of the compound (B2) increases (dielectric constant: Si-X <Si-OH), and the dielectric constant difference between the compound (B2) and the compound (A) increases, and the compound (B A) tends to be unevenly distributed on the outermost layer side, and the average film thickness d of the outermost surface dense layer 14b tends to increase.
From the viewpoint of increasing the average film thickness d of the outermost surface dense layer 14b, the compound (B2) is preferably a silane compound (2) using tetraalkoxysilane having an alkoxy group having 1 or 2 carbon atoms.

In the production method, the refractive index of the silica-based porous film 14 to be formed can be adjusted by the blending amount of the particles (C). For example, as the content of the particles (C) with respect to the total solid content of the coating liquid increases, the refractive index tends to decrease. For example, the refractive index can be 1.38 or less. The lower the refractive index, the lower the reflectance and the better the antireflection performance.
Moreover, according to this manufacturing method, the arithmetic mean roughness of the silica type porous membrane 14 formed can be 3.0 nm or less. This is because the vicinity of the outermost surface is not a porous structure but a dense structure with almost no pores derived from the particles (C), so that the porous structure is broken by an impact in the manufacturing process and the surface smoothness is reduced. This is considered to be able to prevent the decrease. As the hole arithmetic average roughness in the vicinity of the outermost surface is smaller, the wear resistance, antifouling property and the like are improved, and the usefulness as an antireflection film is improved.

As one of known methods for producing a silica-based porous membrane, there is a method in which a coating liquid in which hollow silica fine particles are dispersed in a matrix precursor solution is applied and heat-treated. In the case of this method, if the size of the hollow silica fine particles is small, a silica-based porous film having a surface open pore number of 13/10 ⁶ nm ² or less can be formed. However, when the size of the hollow silica fine particles is increased in order to make the refractive index 1.38 or less (for example, the internal pore diameter is 20 nm or more), pores having a diameter of 20 nm or more are formed between the hollow silica fine particles, A hole opens in the outermost surface. Moreover, since the shape of the hollow silica fine particles is reflected on the outermost surface, the arithmetic average roughness (Sa) tends to be larger than 3 nm.

<Article with Silica-based Porous Membrane of Second Embodiment>
FIG. 3 is a cross-sectional view showing a second embodiment of an article with a silica-based porous film having the silica-based porous film of the present invention on the surface of the article. In the present embodiment, components corresponding to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
An article 20 with a silica-based porous film of the present embodiment includes a glass plate 12, an undercoat layer 16 formed on the surface of the glass plate 12, and a silica-based porous film 14 formed on the surface of the undercoat layer 16. And have.
The undercoat layer 16 has a function as an alkali barrier layer or a wide band low refractive index layer. By having the undercoat layer 16 between the glass plate 12 and the silica-based porous film 14, durability, particularly moisture and heat resistance, is further improved. Further, since the antireflection performance and the reflected color are achromatic, the appearance and the like are improved.

The undercoat layer 16 includes a layer composed only of a matrix mainly composed of silica, a layer having a plurality of pores in a matrix mainly composed of silica, and a silica solid in a matrix mainly composed of silica. Examples thereof include a layer having particles and a layer having silica hollow particles in a matrix mainly composed of silica.
Examples of the matrix mainly composed of silica include a heat-treated product of sol-gel silica (hydrolyzed product or partial condensate of alkoxysilane), a heat-treated product of silazane, and the like, and a heat-treated product of sol-gel silica is preferable.
The thickness of the undercoat layer is preferably 10 to 500 nm.
The refractive index of the undercoat layer is preferably 1.30 to 1.50, more preferably 1.35 to 1.46.

As the alkoxysilane used for the sol-gel silica, the silane compound (1), the silane compound (2), and other known alkoxysilanes can be used. For example, tetraalkoxysilane (tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, etc.), alkoxysilane having a perfluoropolyether group (perfluoropolyether triethoxysilane, etc.), alkoxy having a perfluoroalkyl group Silane (perfluoroethyltriethoxysilane, etc.), alkoxysilane having vinyl group (vinyltrimethoxysilane, vinyltriethoxysilane, etc.), alkoxysilane having epoxy group (2- (3,4-epoxycyclohexyl) ethyltrimethoxy Silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane), acryloyloxy group Alkoxysilanes (3-acryloyloxy propyl trimethoxysilane and the like) or the like having the like.
The hydrolyzate and partial condensate of alkoxysilane can be obtained in the same manner as the hydrolyzate and partial condensate of silane compound (1).

<The manufacturing method of the article with a silica type porous membrane of a second embodiment>
The article 20 with a silica-based porous film forms, for example, a coating liquid (hereinafter also referred to as a lower layer coating liquid) and a silica-based porous film 14 for forming the undercoat layer 16 on the glass plate 12. Can be manufactured by sequentially applying and heat-treating a coating liquid (hereinafter also referred to as an upper layer coating liquid).
The heat treatment may be performed only after the upper layer coating solution is applied, or may be performed after the lower layer coating solution is applied and after the upper layer coating solution is applied. Alternatively, the glass plate 12 may be heated to a heat treatment temperature in advance, and a lower layer coating solution and an upper layer coating solution may be sequentially applied to the surface of the glass plate 12.
50-300 degreeC is preferable and the heat processing temperature in the case of performing heat processing after apply | coating a lower layer coating liquid and before apply | coating an upper layer coating liquid is more preferable.
The upper layer coating solution and the formation procedure of the silica-based porous film 14 using the same are the same as those in the first embodiment.

[Lower layer coating solution]
As a lower layer coating solution, a matrix precursor solution (sol-gel silica solution, silazane solution, etc.); a mixture of particles (C) or hollow particle dispersion and matrix precursor solution; silica solid particle dispersion And a mixture of a matrix precursor solution and the like.
The lower layer coating solution may contain hollow silica particles for improving the transmittance and decolorizing the reflected color, a surfactant for improving the leveling property, a metal compound for improving the durability of the coating film, and the like.

Examples of the matrix precursor include sol-gel silica (alkoxysilane hydrolyzate or partial condensate), silazane and the like, and sol-gel silica is preferable.
As the alkoxysilane, the silane compound (1), the silane compound (2), and other known alkoxysilanes can be used. For example, tetraalkoxysilane (tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, etc.), alkoxysilane having a perfluoropolyether group (perfluoropolyether triethoxysilane, etc.), alkoxy having a perfluoroalkyl group Silane (perfluoroethyltriethoxysilane, etc.), alkoxysilane having vinyl group (vinyltrimethoxysilane, vinyltriethoxysilane, etc.), alkoxysilane having epoxy group (2- (3,4-epoxycyclohexyl) ethyltrimethoxy Silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane), acryloyloxy group Alkoxysilanes (3-acryloyloxy propyl trimethoxysilane and the like) or the like having the like.
Sol-gel silica can be obtained by the same method as the hydrolyzate and partial condensate of the silane compound (1).

Examples of the solvent for the matrix precursor include those similar to the liquid medium (D), and a mixed solvent of water and alcohols (methanol, ethanol, isopropanol, butanol, diacetone alcohol, etc.) is preferable.
As a dispersion medium for the dispersion liquid of particles (C), hollow particles or silica solid particles, water, alcohols, ketones, ethers, cellosolves, esters, glycol ethers, nitrogen-containing compounds, sulfur-containing compounds, etc. And the same as those mentioned for the liquid medium (D).

As a coating method of the coating liquid for forming the undercoat layer 16, known wet coating methods (spin coating method, spray 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, flexo coating method, slit coating method, roll coating method, etc.).
The liquid temperature during application of the coating liquid for forming the undercoat layer 16 is preferably room temperature to 200 ° C, more preferably room temperature to 150 ° C.

While the present invention has been described with reference to the exemplary embodiments, the present invention is not limited to the above-described embodiments. Each configuration in the above embodiment, a combination thereof, and the like are examples, and the addition, omission, replacement, and other modifications of the configuration can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the silica-based porous film 14 is formed by performing a series of steps of applying the coating liquid on the glass plate 12, performing heat treatment, and removing the particles (C) once. Although shown, the present invention is not limited to this. For example, the silica-based porous film 14 may be a film formed by performing the above process a plurality of times. From the viewpoint of ease of production, film homogeneity, etc., it is preferably a film formed by performing the above process once or twice, and a film formed by performing the above process once. It is particularly preferred that
When performing the said process twice or more, the composition (a kind of a matrix precursor, particle | grains (C), a compounding quantity, etc.) of the coating liquid used at each process may be the same or different.

  Articles 10 and 20 with a silica type porous membrane may have other layers other than undercoat layer 16 between glass board 12 and silica type porous membrane 14. Examples of the other layers include a fingerprint removing layer, an antistatic layer, a water-repellent antifouling layer, a hydrophilic antifouling layer, an ultraviolet shielding layer, an infrared shielding layer, and a wavelength conversion layer.

In the said embodiment, although the example which provided the silica type porous membrane of this invention on the glass plate was shown, the article | item which provides the silica type porous membrane of this invention on the surface is not limited to a glass plate. For example, an organic resin film, an organic resin plate, an organic-inorganic hybrid substrate, or the like may be used.
The article provided with the silica-based porous film of the present invention is preferably made of a transparent material such as glass or organic resin, and a glass plate is preferred.

The silica-based porous membrane of the present invention has excellent antifouling properties and good antireflection performance. Moreover, it is excellent also in durability, such as moisture heat resistance and abrasion resistance. Therefore, it is useful as an antireflection film for various articles such as glass plates.
Articles with a silica-based porous film having a silica-based porous film on the surface of the present invention are transparent parts for vehicles (headlight covers, side mirrors, front transparent substrates, side transparent substrates, rear transparent substrates, etc.), transparent for vehicles Parts (instrument panel surface, etc.), meters, architectural windows, show windows, displays (notebook computers, monitors, LCDs, PDPs, ELDs, CRTs, PDAs, etc.), LCD color filters, touch panel substrates, pickup lenses, optics Lenses, eyeglass lenses, camera parts, video parts, CCD cover substrates, optical fiber end faces, projector parts, copier parts, transparent substrates for solar cells, mobile phone windows, backlight unit parts (for example, light guide plates, cold cathode tubes, etc.) ), Backlight unit parts LCD brightness enhancement film (for example, Prism, transflective film, etc.), liquid crystal brightness enhancement film, organic EL light-emitting element component, inorganic EL light-emitting element component, phosphor light-emitting element component, optical filter, end face of optical component, illumination lamp, cover of lighting fixture, amplification laser light source It is useful as an antireflection film, a polarizing film, an agricultural film and the like.
Among the above, in the case of transparent substrates for solar cells, particularly cover glass, antifouling properties that can prevent adhesion of melted sealing materials (such as EVA) in the manufacturing process of solar cells and are difficult to adhere to the adhesion marks. Required. Since the article of the present invention satisfies such a requirement, it is highly useful as a transparent substrate for solar cells.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.
Among Examples 1 to 16 described later, Examples 1 to 12 are examples, and Examples 13 to 16 are comparative examples.
The measurement method and evaluation method used in each example are shown below.

(Average primary particle size of particles)
After the particle dispersion was diluted to 0.1% by mass with water, it was sampled on the collodion membrane and observed with a transmission electron microscope (manufactured by Hitachi, Ltd., model: H-9000), and 100 particles (B ) Were randomly selected, and the average value obtained by measuring the diameter of each particle was defined as the average primary particle size of the particles.

(Weight average molecular weight of matrix precursor)
After the matrix precursor was diluted to 0.5% with tetrahydrofuran, the measurement was performed using a high-speed GPC apparatus (manufactured by Tosoh Corporation, model: HLC-8320GPC).

(Average reflectance (5 ° incidence))
The reflectance of light incident at an incident angle of 5 ° on the surface of the upper layer (silica-based porous film) side of the produced glass plate with a silica-based porous film was measured with a spectrophotometer (manufactured by Hitachi, Ltd., model: U-4100). The average reflectance (%) within the wavelength range of 400 to 1100 nm was determined. In addition, in order to prevent the back surface light reflection of a glass plate, the back surface was painted black and measured.

(Average transmittance (0 ° incidence))
A spectrophotometer (model: U-4100, manufactured by Hitachi, Ltd.) was used to measure the transmittance of light incident at an incident angle of 0 ° on the surface (silica porous film) side of the manufactured glass plate with a silica porous film. The average transmittance (%) in the wavelength range of 400 to 1100 nm was determined. In addition, in order to prevent the back surface light diffusion of the glass plate, the measurement was performed by attaching quartz glass to the back surface with anisole.

(Average total film thickness, outermost surface dense layer average film thickness)
Each of the average total film thickness and the outermost surface dense layer average film thickness was observed with a scanning electron microscope SEM (manufactured by Hitachi, Ltd., model: S-4300) of the cross section of the produced glass plate with a silica-based porous film. From the obtained image, the thickness of each of the silica-based porous film and the outermost surface dense layer was measured at 100 locations, and the average value thereof was calculated.

(Average hole diameter)
The average pore diameter in the upper layer (silica porous membrane) of the produced glass plate with a silica-based porous membrane is 100 pores measured by a scanning electron microscope SEM (manufactured by Hitachi, Ltd., model: S-4300). The diameters were measured and the average value was calculated.

(Number of holes on the outermost surface)
The number of open pores on the outermost surface is determined by scanning electron microscope SEM (manufactured by Hitachi, Ltd., model: S-4300) on the uppermost surface (silica porous membrane) side of the manufactured glass plate with silica porous membrane. The number of openings having a diameter of 20 nm or more present in a region of 1000 nm × 1000 nm was determined from the observed and obtained images.

(Upper layer refractive index)
The refractive index of the silica-based porous film is determined by measuring the manufactured glass plate with the silica-based porous film with an ellipsometer (manufactured by JA Woollam, model: M-2000DI), and measuring the refractive index at a wavelength of 589.3 nm. Asked. In addition, in order to prevent the back surface reflection of a glass plate, the back surface was painted black and measured.

(Arithmetic mean roughness)
The arithmetic average roughness (Sa) of the outermost surface on the upper layer (silica-based porous film) side of the produced glass plate with a silica-based porous film is measured using a scanning probe microscope apparatus (SII Nano Technology, SPA400DFM). The measurement range was 10 μm × 10 μm.

(Average transmittance after moisture resistance test)
The manufactured glass plate with a silica-based porous membrane was put into a constant temperature and humidity chamber at 85 ° C. and a relative humidity of 85%, and a moisture resistance test was performed for 1000 hours.
About the glass plate with a silica type porous membrane after a moisture resistance test, the average transmittance | permeability (0 degree incidence) of wavelength 400-1100nm was calculated | required in the same procedure as the above.
From the measurement results, the amount of change in the average transmittance before and after the moisture resistance test (average transmittance before the moisture resistance test (%) − average transmittance after the moisture resistance test (%)) was determined.
The closer the amount of change is to 0, the higher the heat-and-moisture resistance of the silica-based porous membrane. The amount of change is preferably 0 to 1.5, particularly preferably 0 to 0.5.

(Average transmittance after wear test)
A wear test in which the surface of the produced glass plate with a silica-based porous film is reciprocated 1000 times with a load of 1 kg in a felt of 4.9 cm × 1.25 cm in an atmosphere of 50% humidity and a temperature of 23 ° C. Went.
About the glass plate with a silica type porous membrane after an abrasion test, the average transmittance | permeability (0 degree incidence | injection) of wavelength 400-1100nm was calculated | required in the same procedure as the above.
From the measurement results, the amount of change in average transmittance before and after the wear test (average transmittance before wear test (%) − average transmittance after wear test (%)) was determined.
The closer the amount of change is to 0, the higher the wear resistance of the silica-based porous film. The amount of change is preferably 0 to 1.5, particularly preferably 0 to 0.5.

(Water contact angle)
From the injection needle, 1 μL of water droplets (20 ± 5 ° C.) are dropped onto the surface of the silica-based porous membrane at 6 locations at 1.5 cm intervals, and θ / 2 from the radius and height of the water droplets taken from the horizontal direction. Each contact angle was calculated by the method, and the average value of 6 points was defined as the contact angle of the film.

(EVA peeling force)
A 0.8 mm thick ethylene-vinyl acetate copolymer resin (EVA) film is cut into a width of 5 mm and a length of 40 mm, placed on the surface of a silica-based porous membrane, and held in a drying furnace at 160 ° C. for 30 minutes. did. After removing from the drying oven and the substrate temperature has dropped to room temperature, the force necessary to peel off the EVA film adhering to the silica-based porous membrane (EVA peeling force, unit: g / 5 mm) is measured using a spring balance. It was measured.

(Matrix precursor solution)
Solid content concentration (mass%) of matrix precursor solutions A-1 to A-6 used in each example, solvent, types of matrix precursors (compounds (A) and (B2)) and compositions (matrix precursors) The ratio of each compound when the total amount is 100 mol% (mol% in terms of SiO ₂ )), n = 2 compounds among the silane compounds (1) forming the compound (A) (silane compounds (1- 2)) (mol% in terms of SiO ₂ ) is shown in Table 1.
Solid content concentration (mass%) of matrix precursor solutions B-1 and B-2 used in each example, solvent, types of matrix precursors (compounds (B1) and (B2)) and compositions (matrix precursors) Table 2 shows the ratio of each compound (mol%) when the total amount of is 100 mol%.

In Tables 1 and 2, the solid content concentration is the SiO ₂ equivalent solid content concentration of the matrix precursor.
IPA is isopropyl alcohol.
The methyl methoxy oligomer represents a polymer having several to several tens of silane compounds (1) in which X in the general formula (1) is a methoxy group and two Ys are methyl groups.
The methylphenylmethoxy oligomer represents a polymer having several to several tens of silane compounds (1) in which X in the general formula (1) is a methoxy group and Y is a methyl group and a phenyl group.
The ratio (mol%) of the compound of n = 2 in the silane compound (1) forming the compound (A) and the unreacted X content (mol%) in the compound (A) were determined by NMR measurement. Asked.
Methyl silicate refers to a polymer of several molecules to several tens of molecules of methyltrimethoxysilane.
TEOS represents tetraethoxysilane (a silane compound in which X in the general formula (2) is an ethoxy group).
VTMS indicates vinyltrimethoxysilane (a silane compound in which X in the general formula (1) is a methoxy group, Y is a vinyl group, and n is 1).
MTMS indicates methyltrimethoxysilane (a silane compound in which X in the general formula (1) is a methoxy group, Y is a methyl group, and n is 1).

Matrix precursor solutions A-1 to A-6 were prepared by the following procedure.
A glass container was charged with a predetermined amount of isopropyl alcohol, 4.52 g of water, and 0.22 g of nitric acid having a concentration of 10% by mass as a catalyst, and the mixture was stirred while maintaining the temperature at 25 ° C. A predetermined amount of each of the compound (A) and the compound (B2) was added thereto, and the mixture was stirred for 1 hour, thereby hydrolyzing the compound (A) or co-hydrolyzing the compound (A) and the compound (B2). Matrix precursor solutions A-1 to A-6 were obtained. The predetermined amount of isopropyl alcohol is such an amount that the mass ratio of isopropyl alcohol / water becomes a value shown in Table 1.

Matrix precursor solutions B-1 to B-2 were prepared by the following procedure.
A predetermined amount of ethanol, 4.52 g of water, and 0.22 g of 10 mass% nitric acid as a catalyst were charged in a glass container, and the temperature was kept at 25 ° C. and stirring was performed. A predetermined amount of each of the compound (B1) and the compound (B2) is added thereto, and the mixture is stirred for 1 hour, so that the co-hydrolysis of the compound (B1) and the compound (B1) is performed, and the matrix precursor solutions B-1 to B -2 was obtained. The predetermined amount of ethanol is such an amount that the mass ratio of ethanol / water becomes the value shown in Table 2.

(Particle dispersion)
Table 3 shows the solid content concentration (% by mass), the dispersion medium, the particle material, and the average primary particle diameter (nm) of the particle dispersions C-1 to C-3 used in each example.
PMMA indicates poly (methyl methacrylate) and PS indicates polystyrene.
Each of the particle dispersions C-1 to C-3 was prepared by the following procedure.

[Preparation of Particle Dispersion C-2]
Sodium dodecyl lactate (SDS) and water were charged into a glass container and stirred. Thereto, methyl methacrylate (MMA) was added, stirred and emulsified. As a polymerization initiator, ammonium persulfate (APS) was added, heated to 70 ° C. and held for 1 hour to synthesize particles, and then ethanol was added and diluted to a solid content concentration of 2% by mass to disperse the particles. A liquid C-2 was obtained.

[Preparation of Particle Dispersions C-1 and C-3]
Styrene and water were charged into a glass container and stirred. Thereto was added sodium para-styrenesulfonate hydrate, and the mixture was stirred and emulsified. As a polymerization initiator, potassium peroxodisulfate (KPS) was added, heated to 70 ° C. and held for 10 hours to synthesize the particles, and then ethanol was added and the solid content concentration was 2% by mass or 6% by mass. Were diluted to obtain particle dispersions C-1 and C-3.

[Examples 1-8, 10-16]
Tetraethoxysilane and hollow silica particles are mixed in ethanol, a 0.083 mass% nitric acid aqueous solution is added as a catalyst, the temperature is kept at 25 ° C. and the mixture is stirred for 1 hour, ethanol is added, and the solid content concentration is 2. A lower layer (undercoat layer) coating solution was prepared by diluting to 2% by mass.
The upper layer coating solution was prepared by mixing the particle dispersions of the types and blending amounts (g) shown in Tables 4 to 6, the matrix precursor solution A, the matrix precursor solution B, and ethanol.

The lower layer coating solution is applied to the surface of a glass plate (soda lime glass, manufactured by Asahi Glass Co., Ltd., size: 100 mm × 100 mm, thickness: 3.2 mm) using a spin coater under spin coating conditions of a rotation speed of 500 rpm for 20 seconds. After coating, an undercoat layer was formed by heat treatment at 180 ° C. for 30 seconds.
Next, after coating the upper layer coating liquid on the surface of the undercoat layer with a spin coater under the spin coat conditions (number of revolutions (rpm) × time) shown in Tables 4 to 6, Tables 4 to 6 are applied. A silica-based porous film was formed by heat treatment under the firing conditions shown (temperature × time) to obtain a glass plate with a silica-based porous film.
“←” in Tables 4 to 6 indicates that the conditions are the same as the conditions shown in the left column of the same row.

[Example 9]
The particle dispersion liquid of the type and blending amount shown in Table 5, the matrix precursor solution A, the matrix precursor solution B, and ethanol were mixed to prepare an upper layer coating solution.
After applying the upper layer coating solution on the surface of a glass plate (soda lime glass, manufactured by Asahi Glass Co., Ltd., size: 100 mm × 100 mm, thickness: 3.2 mm) by spin coating (rotation speed: 500 rpm × 20 seconds), A silica-based porous film was formed by heat treatment at 850 ° C. for 3 minutes and 30 seconds to obtain a glass plate with a silica-based porous film.

Said measurement and evaluation were performed about the obtained glass plate with a silica type porous membrane. The results are shown in Tables 4-6.
In addition, scanning electron micrographs of (a) surface (silica porous membrane side) and (b) cross sections of the glass plates with silica-based porous film of Examples 1, 2, 10, 13 to 16 are shown in FIGS. 10 shows.

The silica-based porous membranes of Examples 1 to 12 had a water contact angle of 70 ° or more on the outermost surface, high hydrophobicity, small EVA peeling force, and excellent antifouling property.
In particular, the silica-based porous membranes of Examples 1 and 2 in which the coating solutions having the compound (A) content of 5% by mass and 20% by mass, respectively, with respect to the total solid content have an EVA peeling force of less than 700 g / 5 mm. And antifouling property was high. Moreover, the high transmittance | permeability of 94.5% or more was shown, and it was excellent in the antireflection performance. Furthermore, the change in transmittance after the wear resistance test and after the moisture resistance test was less than 0.5%, and the durability was excellent.
From the results of Examples 1 and 2 and Examples 3 and 4 in which coating solutions having a compound (A) content of 50% by mass and 63% by mass, respectively, with respect to the total solid content, It was confirmed that when the content of A) is greatly increased, the change in the transmittance after the wear resistance test or after the moisture resistance test is increased, and the durability tends to be lowered.
Although it is an Example, the silica porous membrane of Example 5 which does not contain the compound (B1) having a structure containing a double bond in the matrix precursor contains the compound (B1) having a structure containing a double bond As compared with the porous silica membrane of Example 2, the change in average transmittance after the durability test was large, and it was confirmed that the durability was deteriorated.
From the results of Examples 2 and 6 to 8 in which the mass ratio [matrix precursor / particle] of the matrix precursor content (SiO ₂ conversion) to the particle content is different, the smaller the mass ratio [matrix precursor / particle] is, the smaller the mass ratio [matrix precursor / particle] is. It has been confirmed that the average transmittance increases and the durability increases as the mass ratio [matrix precursor / particle] increases.
Although it is an Example, the silica porous membrane of Example 9 which does not have an undercoat layer has a large change in transmittance after the moisture resistance test as compared with Example 2 formed using the same coating solution and under the same conditions. It was confirmed that it was preferable to have an undercoat layer.
In all of Examples 1 to 12, the pores having a diameter of 20 nm or more inside the film were independent holes.

On the other hand, Example 13 using a coating solution having a content of compound (A) of 3.0% by mass relative to the total solid content, and methyl not containing a structure derived from n = 2 silane compound (1-2) The silica-based porous membrane of Example 16 using a coating solution of methoxy oligomer has a water contact angle on the outermost surface of less than 70 °, low hydrophobicity, EVA peel strength of over 700 g / 5 mm, and antifouling properties. It was low.
The silica porous membrane of Example 14 in which the matrix precursor did not contain the compound (B2) formed from the silane compound (2) had a low average transmittance and insufficient durability.
The mass ratio of the matrix precursor content (SiO ₂ equivalent) to the particle content (matrix precursor / particles) is formed using a coating liquid having a 0.7, and the outermost surface open pore number is 52/10 ^6. The silica porous membrane of Example 15 of nm ² had a large average transmittance change after the durability test of 1.5 or more, was insufficient in durability, and was not practical.

DESCRIPTION OF SYMBOLS 10 Article with silica-based porous film 12 Glass plate 14 Silica-based porous film 16 Undercoat layer 20 Article with silica-based porous film

Claims (11)

A silica-based porous film having a plurality of pores in a matrix mainly composed of silica,
The refractive index is in the range of 1.10 to 1.38;
As the holes, including holes having a diameter of 20 nm or more,
The number of holes having a diameter of 20 nm or more opened on the outermost surface is 13/10 ⁶ nm ² or less,
A silica-based porous membrane having a water contact angle of 70 ° or more on the outermost surface.   2. The silica-based porous membrane according to claim 1, wherein an average value of a distance from the outermost surface to the uppermost portion of pores having a diameter of 20 nm or more existing under the outermost surface is 10 to 80 nm.   The silica-based porous film according to claim 1 or 2, wherein the average diameter of the pores is 15 to 100 nm.   The silica-based porous membrane according to any one of claims 1 to 3, wherein pores having a diameter of 20 nm or more existing inside the silica-based porous membrane are independent pores.   The silica-based porous membrane according to any one of claims 1 to 4, wherein the arithmetic average roughness (Sa) of the outermost surface is 3.0 nm or less.   An article with a silica-based porous film having the silica-based porous film according to any one of claims 1 to 5 on the surface of the article. A method for producing an article with a silica-based porous film having a silica-based porous film having a plurality of pores in a matrix mainly composed of silica on the surface of the article,
Applying a coating liquid containing a matrix precursor, particles removable from the matrix, and a liquid medium to the surface of the article and heat-treating the coating liquid;
The matrix precursor contains the following compound (A), the following compound (B1), and the following compound (B2), and satisfies the following condition (I):
The content of the compound (A) is 5% by mass or more based on the total solid content contained in the coating solution,
The method for producing an article with a silica-based porous film, wherein the particles have an average primary particle diameter of 20 to 130 nm.
Compound (A): Hydrolyzate and partial condensate of silane compound (1) represented by the following general formula (1), and silane compound (1) and silane compound represented by the following general formula (2) ( 2) at least one compound selected from the group consisting of co-hydrolysates and partial condensates, and at least a structure derived from a silane compound in which n in the general formula (1) is 2. Compound.
Y _n SiX _4-n (1)
SiX ₄ (2)
[Wherein, X represents a hydrolyzable group, Y represents a non-hydrolyzable group whose dielectric constant of Y-OH is 50 F / m or less, and n represents an integer of 1 to 3. ]
Compound (B1): At least one compound selected from the group consisting of a silane compound in which n in the general formula (1) is 1 or 3, its hydrolysis and partial condensate.
Compound (B2): At least one compound selected from the group consisting of the silane compound (2), a hydrolyzate and a partial condensate thereof.
Condition (I): The compound (A) with respect to the total amount of the number of moles of the silane compound (2) forming the compound (A) and the number of moles of the silane compound (2) forming the compound (B2). The ratio [(1) / (2)] of the total amount of the number of moles of the silane compound (1) to be formed and the number of moles of the silane compound (1) to form the compound (B1) is 0.1 to 25. It is in the range of 0.   The method for producing an article with a silica-based porous film according to claim 7, wherein the compound (B1) has a group having a structure including a double bond as the Y. The mass ratio [matrix precursor / particles] of the content of the matrix precursor (in terms of SiO ₂ ) to the content of the particles in the coating solution is in the range of 0.7 to 6.0. Item 9. A method for producing an article with a silica-based porous film according to Item 7 or 8.   The method for producing an article with a silica-based porous film according to any one of claims 7 to 9, wherein the particles are made of carbon or an organic polymer.   The silica-based porous membrane according to claim 10, wherein the organic polymer is composed of a homopolymer or a copolymer of at least one monomer selected from the group consisting of methyl methacrylate, styrene, acrylonitrile, butadiene and isoprene. Article manufacturing method.