JP7322107B2 - Member having porous layer and coating liquid for forming porous layer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a member having a porous layer containing particles, and a coating liquid for forming a porous film containing particles.

A low refractive index film with a refractive index reduced to 1.3 or less is produced by forming voids in the film using hollow or chain-like silicon oxide particles to contain air (refractive index 1.0). Are known. A method of applying/drying a dispersion of silicon oxide particles is widely used for forming a low refractive index film containing voids therein. Such a low refractive index film is suitably used as a layer constituting an antireflection film.

In a low refractive index film using silicon oxide particles, if the proportion of voids in the film is too high, the film strength is weakened, and wear resistance, scratch resistance, and the like are lowered. In order to solve this problem, in Patent Document 1, hollow silicon oxide particles and solid fine silicon oxide particles are mixed to form a film to increase the strength of the film.

JP 2007-78711 A

However, since the film of Patent Document 1 contains fine silicon oxide particles, voids in the film are reduced and the refractive index is increased. As a result, the refractive index increases as the film strength increases, and the performance as a low refractive index film deteriorates.

The present invention has been made in view of the above problems, and provides a member having a porous layer containing particles, which has a low refractive index and excellent film strength, and a coating liquid for forming the porous layer containing particles. It provides.

A member according to the present invention is a member having a porous layer on a base material,
said porous layer comprising a plurality of silicon oxide particles bound together by an inorganic binder;
and at least one acid selected from the group consisting of the following general formulas (1) to (4).

COOH is selected for _A1 in the formula (1). n is an integer from 2 to 8;

One of A ₂ and A ₃ in formula (2) is SO ₃ H or PO ₃ H ₂ and the other is an acidic group selected from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. A divalent organic group having 1 to 20 carbon atoms is selected for R.

At least one of A ₂ , A ₃ and A ₄ in formula (3) is SO ₃ H or PO ₃ H ₂ and the rest are each from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. It is the acidic group of choice. A trivalent organic group having 1 to 20 carbon atoms is selected for R.

At least one of A ₂ , A ₃ , A ₄ and A ₅ in formula (4) is SO ₃ H or PO ₃ H ₂ and the rest are SO ₃ H, PO ₃ H ₂ , COOH and OH respectively. It is an acidic group selected from the group consisting of A tetravalent organic group having 1 to 20 carbon atoms is selected for R.

Further, the coating liquid according to the present invention comprises silicon oxide particles, an inorganic binder component, an organic solvent, at least one acid selected from the group consisting of the following general formulas (1) to (4), characterized by comprising

COOH is selected for _A1 in the formula (1). n is an integer from 2 to 8;

One of A ₂ and A ₃ in formula (2) is SO ₃ H or PO ₃ H ₂ and the other is an acidic group selected from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. A divalent organic group having 1 to 20 carbon atoms is selected for R.

At least one of A ₂ , A ₃ and A ₄ in formula (3) is SO ₃ H or PO ₃ H ₂ and the rest are each from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. It is the acidic group of choice. A trivalent organic group having 1 to 20 carbon atoms is selected for R.

At least one of A ₂ , A ₃ , A ₄ and A ₅ in formula (4) is SO ₃ H or PO ₃ H ₂ and the rest are SO ₃ H, PO ₃ H ₂ , COOH and OH respectively. It is an acidic group selected from the group consisting of A tetravalent organic group having 1 to 20 carbon atoms is selected for R.

According to the present invention, it is possible to provide a member having a porous layer containing silicon oxide particles, which has a low refractive index and excellent film strength, and to provide a coating liquid for forming the porous layer containing silicon oxide particles. can be realized.

1 is a schematic diagram showing an embodiment of a member of the invention; FIG. (a) is a schematic diagram showing one embodiment of a member having a porous layer containing hollow silicon oxide particles, and (b) showing one embodiment of a member having a porous layer containing chain silicon oxide particles. . It is a figure which shows the structural example of the imaging device using the member of this invention. 1 is a schematic diagram of a lens filter using the member of the present invention; FIG. (a) A schematic diagram of a face shield using the member of the present invention as a translucent member, (b) a schematic diagram of the translucent member.

1(a) and 1(b) are schematic diagrams showing an embodiment of a member 1 according to the present invention. In FIG. 1( a ), the member 1 has a substrate 10 and a porous layer 20 containing silicon oxide particles provided on the substrate 10 .

If necessary, as shown in FIG. 1B, a functional layer 30 such as an antifouling layer or a hydrophilic layer may be provided on the surface of the porous layer 20 opposite to the substrate 10 . Examples of the antifouling layer include a layer containing a fluoropolymer, a fluorosilane monomolecular layer, a layer containing titanium oxide particles, and the like. A hydrophilic polymer layer is preferable for the hydrophilic layer, and a layer containing a polymer having an amphoteric hydrophilic group such as a sulfobetaine group, a carbobetaine group, or a phosphorcholine group is particularly preferable.

Further, as shown in FIG. 1(c), the member 1 may be provided with an intermediate layer 40 between the substrate 10 and the porous layer 20 containing particles. By providing the intermediate layer 40, it becomes possible to prevent the diffusion of impurities from the base material and improve the antireflection performance. Examples of the intermediate layer 40 include inorganic compound layers such as oxides and nitrides, polymer layers, and the like. The intermediate layer 40 may be a single layer made of the materials described above, or may be a laminate in which a plurality of types of layers are laminated. Layers in which low refractive index layers having relatively low refractive indices are alternately laminated are preferred. The high refractive index layer preferably has a refractive index of 1.4 or more, and preferably contains any one selected from the group consisting of zirconium oxide, titanium oxide, tantalum oxide, niobium oxide and hafnium oxide. The low refractive index layer preferably has a refractive index of less than 1.4, and preferably contains one selected from the group consisting of silicon oxide and magnesium fluoride. A functional layer 30 may be provided on the surface of the porous layer 20 together with the intermediate layer 40 .

The member 1 according to the present invention can be preferably used as a lens, mirror, filter, functional film, or the like, depending on the form of the substrate 20 . In particular, it is suitable for applications requiring antireflection performance, such as optical lenses and antireflection films. For example, it can be used for cover glasses of semiconductors and liquid crystal displays, translucent shield members such as face shields and shield partitions, and optical systems of various optical devices. Among others, it is suitable as a lens constituting an imaging optical system of an imaging apparatus that requires high antireflection performance. The member 1 according to the present invention can also be used by attaching it to another member via an adhesive layer.

Embodiments according to the present invention will be specifically described below, but the present invention can be modified as appropriate without departing from the gist thereof, and is not limited to the embodiments described below.

(Base material)
Glass, ceramics, resin, metal, or the like can be used as the material of the base material 20 . Moreover, the shape is not limited, and may be a flat plate, a curved shape having a concave or convex surface, a film, or the like. A translucent base material may be used depending on the application.

The composition of glass or ceramics is not particularly limited. Examples include zirconium oxide, titanium oxide, tantalum oxide, niobium oxide, hafnium oxide, lanthanum oxide, gadolinium oxide, silicon oxide, calcium oxide, barium oxide, sodium oxide, potassium oxide, boron oxide, and aluminum oxide. The base material can be produced by methods such as grinding and polishing, mold forming, and float forming.

A thermoplastic resin or a thermosetting resin is preferable as the resin. Examples of thermoplastic resins include polyethylene terephthalate, PET (polyethylene naphthalate), PP (polypropylene), PMMA (polymethyl methacrylate, acrylic resin), triacetyl cellulose, PC (polycarbonate), cycloolefin polymer, polyvinyl alcohol, and the like. . Thermosetting resins include polyimide, epoxy resin, and urethane resin.

As the metal, a metal composed of one kind of metal element or an alloy containing two or more kinds of elements can be used.

[Porous layer containing particles]
FIGS. 2(a) and 2(b) are schematic diagrams showing partially enlarged porous layers 20 containing particles of the member of the present invention. FIG. 2(a) shows the case where the silicon oxide particles 21 are hollow particles, and FIG. 2(b) shows the case where the silicon oxide particles 21 are chain particles (connected bodies of solid particles). The porous layer 20 has a plurality of voids 23 between a plurality of silicon oxide particles 21 bound together by an inorganic binder 22 and contains an acid 24 in the layer. Moreover, as shown in FIGS. 2A and 2B, the porous membrane 20 is formed by stacking silicon oxide particles 21 on the surface of the base material 10 in a substantially uniform manner.

When used as an antireflection layer, the refractive index of the porous layer 20 is preferably 1.20 or more and 1.30 or less, more preferably 1.20 or more and 1.24 or less. If the refractive index is less than 1.20, the strength of the porous layer may be insufficient due to the large proportion of voids contained in the layer. If the refractive index exceeds 1.30, the refractive index difference between the air and the substrate 10 cannot be sufficiently reduced, and the antireflection effect may not be sufficiently obtained.

The surface of the porous layer 20 is preferably hydrophilic. Specifically, the contact angle of pure water at room temperature of 23° C. and humidity of 40 to 45% RH is preferably 3° or more and 20° or less, more preferably 5° or more and 10° or less. When the contact angle of pure water is less than 3°, moisture tends to enter the film from the surface of the porous layer 20, which tends to impair the environmental stability. If the pure water contact angle exceeds 20°, the bonding between the silicon oxide particles 21 becomes weak, and the wear resistance of the porous layer 20 tends to decrease.

Each element will be described in detail below.

(acid)
The acid 24 contained in the porous layer 20 of the present invention has 2 to 4 acidic groups and satisfies any one of the following general formulas (1) to (4). An acid having 5 or more acidic groups tends to separate in the coating liquid because it is difficult to dissolve in a solvent. Furthermore, it may become a steric hindrance in the porous film, disturbing the arrangement of the particles and causing light scattering.

COOH is selected for _A1 in the general formula (1). n is an integer from 2 to 8; (1) Acids satisfying the formula include tetrafluorosuccinic acid, (Tetrafluorosuccinic Acid), hexafluoroglutaric acid (Hexafluoroglutaric Acid), octafluoroadipic Acid (Octafluoroadipic Acid), dodecafluorosuberic acid (Dodecafluorosuberic Acid), Hexadecafluorosebacine acid (Hexadecafluorosebacic Acid) and the like.

At least one of _A2 and _A3 in general formula (2) is _SO3H or _PO3H2 , and the other _is selected from the group consisting of _SO3H , _{PO3H2 ,} COOH, and OH. It is an acidic group. A divalent organic group having 1 to 20 carbon atoms is selected for R. Acids satisfying the general formula (2) include 4,4'-biphenyldisulfonic acid, methylenediphosphonic acid, 4-phosphonobenzoic acid, 4-Phosphonobutyric Acid, 3-Amino-4-hydroxy-5-nitrobenzenesulfonic Acid, 5-amino-1-naphthol-3-sulfone Acid (5-Amino-1-naphthol-3-sulfonic Acid), 6-Amino-1-naphthol-3-sulfonic Acid (6-Amino-1-naphthol-3-sulfonic Acid), 1-Amino-2-naphthol -4-sulfonic acid (1-Amino-2-naphthol-4-sulfonic Acid), 2,2'-Benzidinedisulfonic acid (2,2'-Benzidinedisulfonic Acid), 4,4'-diaminostilbene-2,2' -disulfonic acid (4,4'-Diaminostilbene-2,2'-disulfonic Acid) and the like.

Each of A ₂ , A ₃ and A ₄ in general formula (3) is an acidic group selected from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. However, at least one of A ₂ , A ₃ and A ₄ is SO ₃ H or PO ₃ H ₂ . A trivalent organic group having 1 to 20 carbon atoms is selected for R. Acids satisfying general formula (3) include Nitrilotris, 1-Hydroxyethane-1,1-diphosphonic Acid, Alendronic Acid, Glycine -N,N-bis,4-sulfophthalic acid (Glycine-N,N-bis,4-Sulfophthalic Acid) and the like.

Each of A ₂ , A ₃ , A ₄ and A ₅ in general formula (4) is an acidic group selected from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. However, at least one of A ₂ , A ₃ , A ₄ and A ₅ is SO ₃ H or PO ₃ H ₂ . A tetravalent organic group having 1 to 20 carbon atoms is selected for R. [4] Acids satisfying the formula include N,N,N',N'-ethylenediaminetetrakis (N,N,N',N'-Ethylenediaminetetrakis), 2-phosphonobutane-1,2,4-tricarboxylic acid (2 -Phosphonobutane-1,2,4-tricarboxylic Acid), 2-hydroxy-1-(2-hydroxy-4-sulfo-1-naphthylazo)-3-naphthoic acid (2-Hydroxy-1-(2-hydroxy-4 -sulfo-1-naphthylazo)-3-naphthoic Acid) and the like.

The acidic group of the acid that satisfies any one of the general formulas (1) to (4) can modify the surface of the silicon oxide particles 21 . In the case of an acid having only one acidic group, only one silicon oxide particle can be modified. This allows one acid to modify multiple particles. As a result, the particles are bonded to each other by the acid 24 and the number of bonding points between the particles increases, so that the strength of the porous layer 20 can be increased.

The acid 24 contained in the porous layer 20 is determined by elemental analysis of the porous layer 20 or separation and quantitative analysis of organic acids by ion exclusion chromatography or the like to determine whether it has any of general formulas (1) to (4). can be specified.

The content of the acid in the porous layer is desirably 0.1 parts by mass or more and 10 parts by mass or less relative to the silicon oxide particles contained in the porous layer. If it is less than 0.1 part by mass, the particles will not be sufficiently dispersed, and the particles will tend to be disordered in the film and the strength of the film will tend to decrease. If the amount is more than 10 parts by mass, the film tends to have a reduced strength because the acid becomes an obstacle and the voids in the film increase.

(Silicon oxide particles)
Examples of silicon oxide particles 21 include spherical, cocoon-shaped, bale-shaped, disk-shaped, rod-shaped, needle-shaped, square-shaped, and chain-shaped particles. When the porous layer 20 is used as an antireflection layer, hollow silicon oxide particles having pores surrounded by shells as shown in FIG. Chain-shaped silicon oxide particles, which are particle linkages, are suitable. As the silicon oxide particles 21, wet silicon oxide particles are desirable. This is because wet silicon oxide particles have a greater number of silanol groups (Si—OH) on the particle surface than dry silicon oxide particles, and thus tend to interact more strongly with the acid 24 .

The hollow silicon oxide particles can lower the refractive index of the film 11 containing the particles by the air (refractive index 1.0) contained in the pores.

As a method for producing hollow silicon oxide particles, for example, known methods described in JP-A-2001-233611 and JP-A-2008-139581 can be used. When the silicon oxide particles 21 are hollow particles, the hollow silicon oxide particles 21 aligned as shown in FIG. A plurality of stacked layers are formed in the vertical direction.

The average particle size of the hollow silicon oxide particles is preferably 15 nm or more and 300 nm or less, more preferably 30 nm or more and 80 nm or less. When the average particle size is less than 15 nm, it is difficult to stably produce particles. If the average particle size exceeds 300 nm, large voids tend to occur between particles, and scattering due to silicon oxide particles tends to occur. However, when the porous layer 20 is not used as an antireflection film, the average particle size need not be 300 nm or less.

Here, the average particle diameter of the hollow silicon oxide particles is the average Feret diameter. This average Feret diameter can be measured by image processing of a transmission electron microscope image of a plurality of hollow silicon oxide particles contained in the coating liquid. As the image processing method, commercially available image processing such as image Pro PLUS (manufactured by Media Cybernetics) can be used. In a predetermined image area, the contrast is appropriately adjusted as necessary, the Feret diameter of each particle is measured by particle measurement, and the average value of a plurality of particles can be calculated.

The shell thickness of the hollow silicon oxide particles is 10% or more and 50% or less, preferably 20% or more and 35% or less of the average particle diameter. If the thickness of the shell is less than 10%, the strength of the particles themselves will be insufficient. If the thickness of the shell exceeds 50%, the ratio of voids to the volume occupied by the particles becomes small, and the effect of using hollow silicon oxide particles, that is, a layer having a refractive index of 1.3 or less cannot be achieved.

The chain-like silicon oxide particles are secondary particles in which a plurality of solid silicon oxide particles, which are primary particles, are continuous while being linear or curved. The size of chain-like particles can be represented by a minor axis and a major axis. The short diameter of the chain-like particles corresponds to the thickness of the chain-like particles, in other words, the average particle diameter of one primary particle. The short diameter can be calculated from the specific surface area obtained by the nitrogen adsorption method for the chain particles extracted from the coating liquid. The average short diameter of the chain-like silicon oxide particles is preferably 8 nm or more and 20 nm or less. If the short diameter is less than 8 nm, the surface area of the silicon oxide particles 21 is excessively increased, and there is a risk that the reliability of the film will be lowered due to the incorporation of moisture and chemical substances in the atmosphere. On the other hand, if the average minor axis exceeds 20 nm, there is a concern that the dispersion in the solvent becomes unstable and the coatability deteriorates.

The length of the chain-like silicon oxide particles corresponds to the length of the secondary particles, and the length of the particles in the coating liquid can be determined by the dynamic light scattering method. The long axis of the chain-like silicon oxide particles is preferably 4 to 8 times the short axis. If the major axis is less than 4 times the minor axis, the film may become dense and the refractive index may not be lowered sufficiently. It gets worse.

In addition, the minor axis and major axis of the chain-like silicon oxide contained in the film can be calculated from the scanning electron microscope image. The minor and major diameters can be measured from images obtained from scanning electron microscopy.

The primary particles that make up the chain-like silicon oxide particles may be in a state in which the individual shape can be clearly observed, or in a state in which the particles are fused to each other and the shape has collapsed. It is preferable to be in a state where the can be clearly observed. The primary particles constituting the chain-shaped silicon oxide particles may be spherical, cocoon-shaped, or bale-shaped, but are particularly preferably cocoon-shaped or bale-shaped, and have a minor axis of 8 nm or more and 20 nm or less, and a major axis of which the minor axis is the same. Particles of 1.5 times or more and 3.0 times or less are particularly preferred.

Particles having shapes other than chain-like silicon oxide particles, such as spherical, cocoon-shaped, bale-shaped, disk-shaped, rod-shaped, needle-shaped, and square-shaped particles, may be mixed in the coating solution. However, if the content of particles having a shape other than chain-like silicon oxide particles is too high, the refractive index becomes high. From the viewpoint of optical performance, it is desirable to add to an extent that the refractive index does not exceed 1.3.

Regardless of the shape, the silicon oxide particles preferably have a surface state that allows them to be bound together by a binder, which will be described later.

(inorganic binder)
The inorganic binder 22 that binds the silicon oxide particles together is preferably a silicon oxide compound. A preferred example of the silicon oxide compound is a cured silicon oxide oligomer obtained by hydrolyzing and condensing a silicate ester.

Since the inorganic binder 22 is the same inorganic material as the silicon oxide particles, the bonding strength between the particles is increased, and a porous layer that is less likely to deteriorate depending on the usage environment can be realized.

The amount of the binder in the porous layer is desirably 5 parts by mass or more and 20 parts by mass or less, more desirably 6 parts by mass or more and 17 parts by mass or less, relative to the silicon oxide particles contained in the porous layer. If the amount of the binder is less than 5 parts by mass, the strength of the film tends to decrease.

FIG. 3 shows a configuration example of an imaging apparatus having a lens barrel (interchangeable lens) as an optical device using the member according to the present invention. FIG. 3 shows a single-lens reflex digital camera combined with a lens barrel (interchangeable lens).

In the present invention, an optical device refers to a device having an optical system such as binoculars, a microscope, a semiconductor exposure device, and an interchangeable lens.

In addition, the imaging apparatus of the present invention refers to electronic equipment having an imaging element that receives light that has passed through an optical element, such as a camera system such as a digital still camera or a digital video camera, or a mobile phone. Note that the imaging device may be in the form of a module mounted on an electronic device, for example, a camera module.

In FIG. 3, a camera body 202 and a lens barrel 201, which is an optical device, are combined.

Light from a subject passes through an optical system including a plurality of lenses 203 and 205 arranged on the optical axis of the imaging optical system in a housing 220 of the lens barrel 201, and is received by an imaging device. The member according to the present invention can also be used as a lens that constitutes an optical system.

A lens 205 is supported by an inner barrel 204 and is movably supported with respect to an outer barrel of a lens barrel 201 for focusing and zooming.

During the observation period before photographing, light from the subject is reflected by the main mirror 207 in the housing of the camera body, passes through the prism 211 , and then through the finder lens 212 to show the photographed image to the photographer. The main mirror 207 is, for example, a half mirror, and light transmitted through the main mirror is reflected by a sub-mirror 208 toward an AF (autofocus) unit 213. This reflected light is used for distance measurement, for example. The main mirror 207 is attached to and supported by a main mirror holder 240 by adhesion or the like. During photographing, the main mirror 207 and the sub-mirror 208 are moved out of the optical path via a drive mechanism (not shown), the shutter 209 is opened, and the photographing light image incident from the lens barrel 201 is formed on the image sensor 210 . Further, the diaphragm 206 is configured to change the brightness and the depth of focus at the time of shooting by changing the aperture area.

By using the member according to the present invention as a lens constituting an optical system, reflection and scattering in the optical system can be suppressed, and excellent images can be obtained.

In addition, since the porous layer 20 of the member according to the present invention has high mechanical strength, it is suitable as the lens filter 250 mounted on the outermost side of the optical system. Depending on the type of lens filter 250, the lens filter 250 has a function of protecting the lens or imparting effects such as softening, color change, polarization, and dimming to the obtained image. An example of lens filter 250 is shown in FIG. The lens filter 250 has a frame 251 provided with a mounting portion 253 such as a screw thread or a bayonet mount for mounting on the housing 220 of the interchangeable lens, and a member (filter member) 252 according to the present invention is fitted. structure. The filter member 252 is provided with the porous layer 20 on the side opposite to the side on which the mounting portion 253 of the frame 251 is provided. Layer 20 is adapted to be located at the light incident surface.

The member according to the present invention can be employed as a translucent member of a face shield. FIG. 5A is a schematic diagram illustrating the face shield 60. FIG. The face shield 60 includes a translucent member 61 and a holding member 67 that holds the translucent member 61 . The holding member 67 has a structure for fixing the translucent member 61 to the user so that the translucent member 61 covers at least part of the user's face. The holding member 67 includes a fixing portion 65 to which the translucent member 61 is fixed, and a support portion 66 for fixing the fixing portion 65 to the user. The support portion 66 is coupled to the fixed portion 65 . The fixed portion 65 is rod-shaped, and the peripheral portion of the translucent member 61 is fixed to the fixed portion 65 on the side surface of the fixed portion 65 by a fixing component 69 such as a pin or a screw. The fixing part 69 can pass through the notches 91 and holes 92 of the translucent member 61 shown in FIG. 5(b). A belt-shaped support portion 66 is worn by the wearer to support the fixing portion 65 . The translucent member 61 of the face shield 60 covers, for example, at least one, preferably all of the user's eyes, nose and mouth.

The outer surface (the surface opposite to the face side) of the translucent member 61 in the face shield 60 can be the front side, and the inner surface (the face side surface) can be the back side. Since the light source on the outer surface side can be the main factor of the reflected light, it is preferable to provide the porous layer on the outer surface side when an antireflection effect is expected. Also, the use of the face shield 60 is more likely to cause scratches on the outer surface than on the inner surface. Therefore, considering the scratch resistance of the translucent member 61, it is preferable to provide the porous layer on the outer surface side. It is also preferable to make it thicker than

The face shield 60 may be provided with a ventilation fan 68 for ventilating the atmosphere adjacent to the translucent member 61 . In this example, a ventilation fan 68 is provided inside the holding member 67 (fixed portion 65).

The use of the face shield 60 according to this embodiment not only protects the wearer's face, but also improves the work efficiency of the wearer due to the excellent visibility of the translucent member 61. There is an effect that the person facing the wearer can easily recognize the wearer's face and expression.

Although the face shield has been described in FIG. 5, the member according to the present invention is also suitable as a translucent member for a shield partition.

[Method for producing coating liquid and member]
Next, the coating liquid used for manufacturing the porous layer 20 will be described, and then the method for manufacturing the member 1 will be described.

(Coating liquid)
The coating liquid according to the present invention contains silicon oxide particles 21 , an acid 24 , an inorganic binder 22 component, and an organic solvent, which constitute the porous layer 20 .

Silicon oxide particles 21 and acid 24 are as described above.

As shown in FIGS. 2(a) and 2(b), the porous membrane 20 is formed by stacking silicon oxide particles 21 on the surface of the substrate 10 in multiple stages. A film in which the silicon oxide particles 21 are not evenly arranged tends to have an uneven stress distribution and a decrease in strength. state is desirable.

The alignment of the silicon oxide particles 21 mainly depends on the state of dispersion of the silicon oxide particles 21 in the coating liquid that forms the porous layer 20 containing the particles, and the coating film formation after applying the coating liquid to the substrate. It is affected by the dispersion state of the silicon oxide particles 21 at the time.

When the silicon oxide particles 21 are uniformly dispersed in the coating liquid, the silicon oxide particles 21 can be uniformly applied onto the substrate 10, and the silicon oxide particles 21 in the film after formation can be reduced. It tends to be highly ordered. If the silicon oxide particles 21 in the coating liquid are dispersed in an aggregated state under the influence of the dispersion medium and the component that becomes the inorganic binder 22, the particles in an aggregated state are coated and arranged on the substrate 10. Sex gets worse.

Further, even if the silicon oxide particles 21 are well dispersed in the coating liquid, if the silicon oxide particles 21 aggregate during the drying process after applying the coating liquid to the substrate, The alignment of the silicon oxide particles 21 is deteriorated.

Therefore, in order to obtain a film having excellent strength, the silicon oxide particles 21 must be uniformly dispersed in the coating liquid, and the silicon oxide particles 21 must be dispersed in the drying process of the coating liquid after coating on the substrate 10. It is desirable not to agglomerate.

Since the coating liquid used for manufacturing the porous layer 20 according to the present invention contains at least one acid selected from the group of acids listed in general formulas (1) to (4), the coating liquid The surfaces of the silicon oxide particles 21 in the working liquid are modified with the acid 24 . Due to the modification with the acid 21, the silicon oxide particles 21 are electrically charged and repel each other, so that the aggregation of the particles is suppressed and the particles are uniformly dispersed. This state is maintained even in the process of drying the coating liquid after it is applied to the substrate. Therefore, by using the coating liquid according to the present invention, a film having excellent strength in which the silicon oxide particles 21 are regularly and densely arranged can be obtained. can be realized.

The molecular weight of acid 24 is preferably 100 or more and 360 or less. If the molecular weight is less than 100, the viscosity tends to increase, making coating difficult, and the stability of the coating liquid over time tends to deteriorate. If the molecular weight is more than 360, an acid with a large molecular weight will be present between the particles, so the voids formed in the film will tend to be large and scattering will tend to occur easily.

The acid 24 is preferably contained in the range of 0.05 parts by mass or more and 10 parts by mass or less, more preferably 0.1 parts by mass or more and 2.0 parts by mass or less, relative to the silicon oxide particles. If the acid 24 contained in the coating liquid is less than 0.05 parts by mass relative to the silicon oxide, there is a tendency that the aggregation of the silicon oxide particles 21 cannot be suppressed after the coating liquid is applied to the substrate. Alternatively, the dispersion stability of the silicon oxide particles 21 is deteriorated due to the influence of the solvent and binder components in the coating liquid, and the coating liquid tends to thicken or gel over time. If the acid 24 is contained in an amount of more than 10 parts by mass relative to the silicon oxide, the acid 24 tends to hinder the alignment of the silicon oxide particles 21, increasing the voids 6 and reducing the strength.

The acid dissociation constant of acid 24 is preferably -1.2 pKa or more and 2 pKa or less, more preferably -1.2 pKa or more and 0.3 pKa or less. If the acid dissociation constant is less than -1.2 pKa, the arrangement of the silicon oxide particles 21 will be disturbed during the drying process after application to the substrate 10, and the strength of the film will tend to decrease. When the acid dissociation constant is larger than 2 pKa, the dispersibility of the silicon oxide particles 21 in the coating liquid is deteriorated, the alignment in the film is deteriorated, and the strength of the resulting film tends to be weak.

The acids 24 represented by the general formulas (1) to (4) are preferred in that they are highly safe in handling raw materials and many are in a solid state, and are easy to handle.

The component that becomes the inorganic binder 22 is preferably a silicon oxide oligomer. Silicon oxide particles originally have silanol (Si—OH) groups on the surface, but the number of silanol groups on the surface can be further increased by mixing with silicon oxide oligomers in the coating solution. As a result, it becomes possible to achieve a surface state in which the silicon oxide particles 21 are more likely to bind to each other. When the coating composition is applied and dried, the silicon oxide oligomer turns into silicon oxide, and a plurality of chain-like silicon oxide particles 21 are fixed in contact with each other, so a film with high scratch resistance can be realized. .

In the coating liquid of the present invention, the content of the component that becomes the inorganic binder 22 is preferably 0.2 parts by mass or more and 20 parts by mass or less relative to the silicon oxide particles 21, and more preferably 0.2 parts by mass or more and 17 parts by mass or less. preferable. If the content of the component that becomes the inorganic binder 22 is less than 0.2 parts by mass relative to the silicon oxide particles 21, the silicon oxide particles 21 cannot be sufficiently dispersed in the dispersion liquid, and a high-strength film cannot be obtained. tend to be unobtainable. Further, when the content of the component that becomes the inorganic binder 22 is more than 10 parts by mass with respect to the silicon oxide particles 21, the inorganic binder disturbs the arrangement of the particles, and the obtained film deteriorates the scattering of visible light. The refractive index tends to increase.

The organic solvent that can be used for the coating liquid may be any solvent that does not precipitate the silicon oxide particles 21 or cause the coating liquid to rapidly increase in viscosity. Examples include the following solvents. Methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methylpropanol, 1-pentanol, 2-pentanol, cyclopentanol, 2-methylbutanol, 3-methylbutanol, 1 -hexanol, 2-hexanol, 3-hexanol, 4-methyl-2-pentanol, 2-methyl-1-pentanol, 2-ethylbutanol, 2,4-dimethyl-3-pentanol, 3-ethylbutanol, monohydric alcohols such as 1-heptanol, 2-heptanol, 1-octanol and 2-octanol; Dihydric or higher alcohols such as ethylene glycol and triethylene glycol. Ethers such as methoxyethanol, ethoxyethanol, propoxyethanol, isopropoxyethanol, butoxyethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-propoxy-2-propanol, 3-methoxy-1-butanol Ethers such as alcohols, dimethoxyethane, diglyme (diethylene glycol dimethyl ether), tetrahydrofuran, dioxane, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether. Esters such as ethyl formate, ethyl acetate, n-butyl acetate, methyl lactate, ethyl lactate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate and propylene glycol monomethyl ether acetate. various aliphatic or alicyclic hydrocarbons such as n-hexane, n-octane, cyclohexane, cyclopentane and cyclooctane; Various aromatic hydrocarbons such as toluene, xylene and ethylbenzene. Various ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone. Various chlorinated hydrocarbons such as chloroform, methylene chloride, carbon tetrachloride, tetrachloroethane. aprotic polar solvents such as N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, ethylene carbonate; Among these solvents, it is also possible to use a mixture of two or more kinds of solvents.

From the viewpoint of the dispersibility of the silicon oxide particles 21 and the applicability of the coating liquid, it is preferable that 30 mass % or more of the solvent contained in the coating liquid is a water-soluble solvent having a hydroxyl group with 4 or more and 6 or less carbon atoms. . from ethoxyethanol, propoxyethanol, isopropoxyethanol, butoxyethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-propoxy-2-propanol, ethyl lactate, 3-methoxy-1-butanol, among others It is particularly preferred to include at least one selected solvent. The use of these solvents suppresses radial coating traces that occur during coating and liquid residue on the periphery of the substrate, thereby improving coatability.

(Manufacturing method of member)
The method for manufacturing the member 1 of the present invention includes the steps of applying the coating liquid onto the base material 10 and drying and/or baking the base material 10 to which the coating liquid has been applied. .

Examples of methods for applying the coating liquid to the substrate 10 include spin coating, blade coating, roll coating, slit coating, printing, gravure coating, and dip coating. When manufacturing a member having a three-dimensionally complicated shape such as a concave surface, the spin coating method is preferable because it is easy to apply a uniform thickness.

The step of drying and/or curing is a step for removing the organic solvent and binding the silicon oxide particles 21 without disturbing their alignment to form the porous layer 20 . The step of drying and/or curing depends on the heat resistance temperature of the substrate 10, but it is preferable to process at 20°C or higher and 200°C or lower. The time for the drying and/or curing step may be any time that does not affect the substrate 10 and can remove the organic solvent in the layer, but is preferably 5 minutes or more and 200 hours or less. It is preferably 30 minutes or more and 24 hours or less.

In Examples 1 to 18, a coating liquid for forming the porous layer 20 was prepared by the following method, the porous layer was formed on the substrate, and a member having the porous layer 20 was manufactured. 1 was produced. At that time, the coating liquid and the obtained porous layer 20 were evaluated as follows.

<Evaluation of Coatability of Coating Solution>
A coating liquid was dropped onto the polished surface of a glass substrate (φ30 mm, synthetic quartz with a thickness of 1 mm, one side of which was polished) so that the thickness of the porous layer 20 was about 110 nm, and a film was formed by a spin coater. At that time, the appearance of the film containing the particles was observed with an optical microscope to see if any defects occurred, and evaluation was made according to the following criteria.
A: Coating unevenness is not observed B: Inconspicuous dripping marks and foreign matter are slightly generated C: Remarkable coating unevenness such as streak-like unevenness due to foreign matter occurs and appearance is bad If the evaluation is A, the coatability is poor. In the case of B, it was judged that the coatability was good.

<Strength Evaluation of Porous Layer>
A porous layer 20 was formed on the polished surface of a glass substrate (synthetic quartz having a diameter of 30 mm and a thickness of 1 mm and having one side polished). After reciprocating the surface of the porous layer 20 50 times with a polyester wiper (alpha wiper TX1009 manufactured by Texwipe Co., Ltd.) with a load of 300 g/cm 2 , the appearance was evaluated with an optical microscope. Evaluation criteria are as follows.
A: Almost no change in appearance B: Slight change in appearance, fine line scratches, etc. C: Significant change in appearance, line scratches, film peeling, etc. In the invention, when the evaluation was A, the strength was excellent, and when the evaluation was B, the strength was good, and it was determined that there was no problem with the strength.

<Evaluation of refractive index of porous layer>
A porous layer 20 containing particles was formed on the polished surface of a glass substrate (synthetic quartz having a diameter of 30 mm and a thickness of 1 mm and having one side polished). Using a spectroscopic ellipsometer (VASE, manufactured by JA Woollam Japan), light is incident on the porous layer 20, and the reflected light is measured from a wavelength of 380 nm to 800 nm to calculate the refractive index. Refraction at a wavelength of 550 nm rate was evaluated according to the following criteria.
A: 1.24 or less B: More than 1.24 and 1.30 or less C: More than 1.30 If the evaluation is A or B, it is judged that a porous layer suitable as a low refractive index layer has been obtained. bottom.

<Evaluation of scattering of porous layer>
A glass substrate (φ30 mm, 1 mm thick synthetic quartz with both sides polished) was placed on a substrate holder. An illuminance meter (T-10M, manufactured by Konica Minolta Sensing Co., Ltd.) was installed on the substrate holder, and while measuring the illuminance, white light was irradiated so that the illuminance from the vertical direction on the surface of the substrate was 4000 lux. Next, a member in which the porous layer 20 was formed on the same glass substrate was placed on a substrate holder so that white light was irradiated from the porous layer 20 side. The installed member was tilted at 45°, and photographed with a camera (lens: EF 50 mm F2.5 manufactured by Compact Macro Canon Inc., camera: EOS-70D manufactured by Canon Inc.) from the normal direction of the surface opposite to the irradiated surface. The photographing conditions of the camera were ISO 400, white balance fine, aperture 10, and shutter speed 10 seconds. From the obtained image, the average brightness value was calculated for arbitrary four points of 700 pix×700 pix and used as the scattering value.

In the present invention, when the scattering value calculated by the method described above was 25 or less, the porous layer 20 was evaluated as having low scattering.

<Contact angle of porous layer>
Pure water was dropped on the surface of the porous layer opposite to the substrate, and the contact angle of pure water was measured at room temperature of 23° C. and humidity of 40 to 45% RH. The contact angle was measured by taking an image 1000 ms after dropping the pure water.

[Example 1]
1-Ethoxy-2-propanol was added to 400 g of an isopropyl alcohol dispersion of hollow silicon oxide particles (Sururia 1110 manufactured by Nikki Shokubai Kasei Co., Ltd., average particle diameter of about 50 nm, shell thickness of about 10 nm, solid content concentration of 20.5% by mass). While adding, the isopropyl alcohol was distilled off by heating. Isopropyl alcohol was distilled off until the solid concentration reached 19.5% by mass to prepare 420 g of a 1E2P solvent replacement solution for hollow silicon oxide particles (hereinafter referred to as solvent replacement solution 1). An acid was added to the obtained solvent replacement liquid 1 so that the mass ratio of the hollow silicon oxide particles to the acid component was 400:1, whereby a dispersion liquid 1 was obtained. The added acid is an acid having two acidic groups (Tetrafluorosuccinic Acid, manufactured by Tokyo Chemical Industry Co., Ltd.).

In another container, 12.48 g of ethyl silicate, 13.82 g of ethanol, and an aqueous nitric acid solution (3% concentration) were added and stirred at room temperature for 10 hours to prepare silica sol 1 (solid concentration: 11.5% by mass). It was confirmed by gas chromatography that the starting ethyl silicate had completely reacted.

Dispersion 1 was diluted with ethyl lactate so that the solid content concentration was 3.9% by mass, and then silica sol 1 was added so that the ratio of hollow silicon oxide particles to silica sol component was 100:11. Furthermore, a coating liquid 1 containing hollow silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The resulting coating liquid 1 was dropped onto a glass substrate, and the formed porous layer was formed into a film with a spin coater so as to have a thickness of about 110 nm, and then baked at 140° C. for 30 minutes in a constant temperature furnace. A member 1-1 having a porous layer 20-1 containing particles was obtained. The contact angle of pure water on the surface of the porous layer 20-1 opposite to the substrate was 10°.

[Example 2]
Dispersion liquid 2 was obtained by adding acid to solvent replacement liquid 1 so that the ratio of the hollow silicon oxide particles to the acid component was 400:1. The added acid is an acid having two acidic groups (Octafluoroadipic Acid manufactured by Tokyo Chemical Industry Co., Ltd.).

Dispersion 2 was diluted with ethyl lactate so that the solid content concentration was 3.9% by mass, and then silica sol 1 was added so that the mass ratio of hollow silicon oxide particles to silica sol component was 100:11. Furthermore, a coating liquid 2 containing hollow silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The obtained coating liquid 2 was dropped onto a glass substrate, and after forming a film with a spin coater so that the formed porous layer had a thickness of about 110 nm, it was baked at 140° C. for 30 minutes in a constant temperature furnace. A member 1-2 having a porous layer 20-2 containing particles was obtained. The contact angle of pure water on the surface of the porous layer 20-2 opposite to the substrate was 10°.

[Example 3]
To 350 g of an aqueous dispersion of hydrophilic silicon oxide particles (PL-1 manufactured by Fuso Chemical Industry Co., Ltd., average particle diameter of about 15 nm, length/breadth = 2.6, solid content concentration of 12% by mass), 1-methoxy-2 -Water was distilled off by heating while adding propanol (hereinafter abbreviated as PGME). Water was distilled off until the solid concentration reached 15% by mass to prepare 280 g of a PGME solvent replacement solution for hydrophilic silicon oxide particles (hereinafter referred to as solvent replacement solution 2). An acid was added to the obtained solvent replacement liquid 2 so that the weight ratio of the hydrophilic silicon oxide particles to the acid component was 100:1 to obtain a dispersion liquid 3. The added acid is an acid having three acidic groups (Nitrilotris manufactured by Tokyo Chemical Industry Co., Ltd.).

Dispersion 3 was diluted with 1-propoxy-2-propanol so that the solid content concentration was 4.5% by mass, and then silica sol was added so that the ratio of hydrophilic silicon oxide particles to silica sol components was 100:6. 1 was added. Furthermore, the coating liquid 3 containing hydrophilic silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The resulting coating liquid 3 was dropped onto a glass substrate, and the formed porous layer was formed into a film with a spin coater so as to have a thickness of about 110 nm. A member 1-3 having a porous layer 20-3 containing chain-like silicon oxide particles was obtained. The contact angle of pure water on the surface of the porous layer 20-3 opposite to the substrate was 6°.

[Example 4]
An acid was added to the solvent replacement liquid 2 so that the weight ratio of the hydrophilic silicon oxide particles to the acid component was 200:1, and a dispersion liquid 4 was obtained. The added acid is an acid having four acidic groups (N,N,N',N'-Ethylenediaminetrakis manufactured by Tokyo Chemical Industry Co., Ltd.).

After diluting the dispersion liquid 4 with 1-propoxy-2-propanol so that the solid content concentration is 4.5% by mass, the hydrophilic silicon oxide particles:silica sol component is diluted so that the mass ratio is 100:6. Silica sol 1 was added. Furthermore, a coating liquid 4 containing hydrophilic silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The resulting coating liquid 4 is dropped onto a glass substrate, and the resulting porous layer is formed into a film with a spin coater so as to have a thickness of about 110 nm. A member 1-4 having a porous layer 20-4 containing linear silicon oxide particles was obtained. The contact angle of pure water on the surface of the porous layer 20-4 opposite to the substrate was 7°.

[Example 5]
An acid was added to the solvent replacement liquid 2 so that the weight ratio of the hydrophilic silicon oxide particles to the acid component was 200:1, and a dispersion liquid 5 was obtained. The added acid is an acid having two acidic groups (Tetrafluorosuccinic Acid, manufactured by Tokyo Chemical Industry Co., Ltd.).

After diluting the dispersion 5 with 1-propoxy-2-propanol so that the solid content concentration is 4.5% by mass, the hydrophilic silicon oxide particles:silica sol component is diluted so that the mass ratio is 100:6. Silica sol 1 was added. Further, the mixture was mixed and stirred at room temperature for 2 hours to obtain a coating liquid 5 containing hydrophilic silicon oxide particles.

The resulting coating liquid 5 is dropped onto a glass substrate, and the resulting porous layer is formed into a film with a spin coater so as to have a thickness of about 110 nm. A member 1-5 having a porous layer 20-5 containing linear silicon oxide particles was obtained. The contact angle of pure water on the surface of the porous layer 20-5 opposite to the substrate was 7°.

[Example 6]
An acid was added to the solvent replacement liquid 1 so that the mass ratio of the hollow silicon oxide particles to the acid component was 500:1, and a dispersion liquid 6 was obtained. The added acid is an acid having two acidic groups (Tetrafluorosuccinic Acid, manufactured by Tokyo Chemical Industry Co., Ltd.).

Dispersion 6 was diluted with ethyl lactate so that the solid content concentration was 3.9% by mass, and then silica sol 1 was added so that the mass ratio of hollow silicon oxide particles to silica sol component was 100:6. Furthermore, a coating liquid 6 containing hollow silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The obtained coating liquid 6 is dropped onto a glass substrate, and the formed porous layer is formed into a film with a spin coater so that the thickness is about 110 nm, and then baked at 140° C. for 30 minutes in a constant temperature furnace. A member 1-6 having a porous layer 20-6 containing particles was obtained. The contact angle of pure water on the surface of the porous layer 20-6 opposite to the substrate was 10°.

[Example 7]
An acid was added to the solvent replacement liquid 1 so that the ratio of the hollow silicon oxide particles to the acid component was 250:1, and a dispersion liquid 7 was obtained. The added acid is an acid having two acidic groups (Octafluoroadipic Acid manufactured by Tokyo Chemical Industry Co., Ltd.).

Dispersion 7 was diluted with ethyl lactate so that the solid content concentration was 3.9% by mass, and then silica sol 1 was added so that the mass ratio of hollow silicon oxide particles to silica sol component was 100:11. Furthermore, a coating liquid 7 containing hollow silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The obtained coating liquid 7 is dropped onto a glass substrate, and the formed porous layer is formed into a film with a spin coater so that the thickness is about 110 nm, and then baked at 140° C. for 30 minutes in a constant temperature furnace. A member 1-7 having a porous layer 20-7 containing particles was obtained. The contact angle of pure water on the surface of the porous layer 20-7 opposite to the substrate was 10°.

[Example 8]
An acid was added to the solvent replacement liquid 2 so that the ratio of the hydrophilic silicon oxide particles to the acid component was 100:1, and a dispersion liquid 8 was obtained. The added acid is an acid having two acidic groups (Tetrafluorosuccinic Acid, manufactured by Tokyo Chemical Industry Co., Ltd.).

After diluting dispersion liquid 8 with 1-propoxy-2-propanol so that the solid content concentration is 4.5% by mass, silica sol is added so that the ratio of hydrophilic silicon oxide particles to silica sol components is 100:6. 1 was added. Furthermore, a coating liquid 8 containing hydrophilic silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The obtained coating liquid 8 is dropped onto a glass substrate, and the formed porous layer is formed into a film with a spin coater so that the thickness is about 110 nm, and then baked at 140° C. for 30 minutes in a constant temperature furnace. A member 1-8 having a porous layer 20-8 containing linear silicon oxide particles was obtained. The contact angle of pure water on the surface of the porous layer 20-8 opposite to the substrate was 7°.

[Example 9]
An acid was added to the solvent replacement liquid 2 so that the ratio of the hydrophilic silicon oxide particles to the acid component was 10:1, and a dispersion liquid 9 was obtained. The added acid is an acid having two acidic groups (Tetrafluorosuccinic Acid, manufactured by Tokyo Chemical Industry Co., Ltd.).

After diluting dispersion liquid 9 with 1-propoxy-2-propanol so that the solid content concentration is 4.5% by mass, the hydrophilic silicon oxide particles:silica sol component is diluted so that the mass ratio is 100:6. Silica sol 1 was added. Furthermore, a coating liquid 9 containing hydrophilic silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The obtained coating liquid 9 is dropped onto a glass substrate, and after forming a film with a spin coater so that the formed porous layer has a thickness of about 110 nm, it is baked at 140° C. for 30 minutes in a constant temperature furnace. A member 9 having a porous layer 20-9 containing particles was obtained. The contact angle of pure water on the surface of the porous layer 20-9 opposite to the substrate is 6°.

[Example 10]
An acid was added to the solvent replacement liquid 1 so that the ratio of the hollow silicon oxide particles to the acid component was 200:1, and a dispersion liquid 10 was obtained. The added acid is an acid having two acidic groups (Dodecafluorosuberic Acid manufactured by Tokyo Chemical Industry Co., Ltd.).

Slowly add 11.41 g of 1-propoxy-2-propanol and 4.5 g of methyl polysilicate (Methyl silicate 53A manufactured by Colcoat Co., Ltd.) to another container and stir at room temperature for 120 minutes to prepare silica sol (hereinafter referred to as silica sol 2). bottom.

After diluting the dispersion liquid 10 with 1-propoxy-2-propanol so that the solid content concentration is 3.9% by mass, silica sol is added so that the mass ratio of the hollow silicon oxide particles to the silica sol component is 100:11. 1 was added. Furthermore, the coating liquid 10 containing the hollow silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours. After forming a film with a spin coater so as to have a thickness of 100 mm, it was baked in a constant temperature furnace at 140° C. for 30 minutes to obtain a member 1-10 having a porous layer 20-10 containing particles. The contact angle of pure water on the surface of the porous layer 20-10 opposite to the substrate was 10°.

[Example 11]
An acid was added to the solvent replacement liquid 1 so that the ratio of the hollow silicon oxide particles to the acid component was 200:1, and a dispersion liquid 11 was obtained. The added acid is an acid having two acidic groups (Dodecafluorosuberic Acid manufactured by Tokyo Chemical Industry Co., Ltd.).

Dispersion 10 was diluted with ethyl lactate so that the solid content concentration was 3.9% by mass, and then silica sol 2 was added so that the mass ratio of hollow silicon oxide particles to silica sol component was 100:11. Furthermore, a coating liquid 11 containing hollow silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The obtained coating liquid 11 is dropped onto a glass substrate, and the formed porous layer is formed into a film with a spin coater so that the thickness is about 110 nm, and then baked at 140° C. for 30 minutes in a constant temperature furnace. A member 1-11 having a porous layer 20-11 containing particles was obtained. The contact angle of pure water on the surface of the porous layer 20-11 opposite to the substrate was 9°.

[Example 12]
Dispersion 12 was obtained by adding acid to solvent replacement liquid 1 so that the ratio of the hollow silicon oxide particles to the acid component was 250:1. The added acid is an acid having two acidic groups (Dodecafluorosuberic Acid manufactured by Tokyo Chemical Industry Co., Ltd.).

After diluting dispersion liquid 10 with 3-methoxy-1-butanol so that the solid content concentration is 3.9% by mass, silica sol is added so that the mass ratio of hollow silicon oxide particles:silica sol component is 100:11. 1 was added. Furthermore, a coating liquid 12 containing hollow silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The obtained coating liquid 12 is dropped onto a glass substrate, and after forming a film with a spin coater so that the formed porous layer has a thickness of about 110 nm, it is baked at 140° C. for 30 minutes in a constant temperature furnace. A member 1-12 having a porous layer 20-12 containing particles was obtained. The contact angle of pure water on the surface of the porous layer 20-12 opposite to the substrate was 8°.

[Example 13]
Dispersion 13 was obtained by adding acid to solvent replacement liquid 1 so that the ratio of hollow silicon oxide particles to acid component was 200:1. The added acid is an acid having two acidic groups (Hexafluoroglutaric Acid manufactured by Tokyo Chemical Industry Co., Ltd.).

After diluting dispersion liquid 10 with 3-methoxy-1-butanol so that the solid content concentration is 3.9% by mass, silica sol is added so that the mass ratio of hollow silicon oxide particles:silica sol component is 100:11. 2 was added. Furthermore, a coating liquid 13 containing hollow silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The obtained coating liquid 13 is dropped onto a glass substrate, and after forming a film with a spin coater so that the formed porous layer has a thickness of about 110 nm, it is baked at 140° C. for 30 minutes in a constant temperature furnace. A member 1-13 having a porous layer 20-13 containing particles was obtained. The contact angle of pure water on the surface of the porous layer 20-13 opposite to the substrate was 8°.

[Example 14]
1-propoxy-2-propanol was mixed with 400 g of an isopropyl alcohol dispersion of hollow silicon oxide particles (Sururia 1110 manufactured by Nikki Shokubai Kasei Co., Ltd., average particle diameter: about 50 nm, shell thickness: about 10 nm, solid content concentration: 20.5% by mass). Then, a dispersion liquid 14 having a solid content concentration of 3.9% by mass was obtained.

Acid was added to Dispersion 14 such that the ratio of hollow silicon oxide particles to the acid component was 250:1. The added acid is an acid having two acidic groups (Dodecafluorosuberic Acid manufactured by Tokyo Chemical Industry Co., Ltd.).

Furthermore, silica sol 2 was added so that the mass ratio of hollow silicon oxide particles to silica sol component was 100:11. Thereafter, the mixture was mixed and stirred at room temperature for 2 hours to obtain a coating liquid 14 containing hollow silicon oxide particles.

The resulting coating liquid 14 is dropped onto a glass substrate, and the resulting porous layer is formed into a film with a spin coater so as to have a thickness of about 110 nm. to obtain a member 1-14 having a porous layer 20-14 containing particles. The contact angle of pure water on the surface of the porous layer 20-14 opposite to the substrate was 10°.

[Example 15]
Ethyl lactate was mixed with 400 g of an isopropyl alcohol dispersion of hollow silicon oxide particles (Sururia 1110 manufactured by Nikki Shokubai Kasei Co., Ltd., average particle diameter of about 50 nm, shell thickness of about 10 nm, solid content concentration of 20.5% by mass), and the solid content concentration was A dispersion liquid 15 having a content of 3.9% by weight was obtained.

Acid was added to Dispersion 15 such that the ratio of hollow silicon oxide particles to the acid component was 250:1. The added acid is an acid having two acidic groups (Dodecafluorosuberic Acid manufactured by Tokyo Chemical Industry Co., Ltd.).

Furthermore, silica sol 2 was added so that the mass ratio of hollow silicon oxide particles to silica sol component was 100:11. Thereafter, the mixture was mixed and stirred at room temperature for 2 hours to obtain a coating liquid 15 containing hollow silicon oxide particles.

The obtained coating liquid 15 is dropped onto a glass substrate, and after forming a film with a spin coater so that the formed porous layer has a thickness of about 110 nm, it is baked at 140° C. for 30 minutes in a constant temperature furnace. to obtain a member 1-15 having a porous layer 20-15 containing particles. The contact angle of pure water on the surface of the porous layer 20-15 opposite to the substrate was 7°.

[Example 16]
1-propoxy-2-propanol was mixed with 200 g of an isopropyl alcohol dispersion of hollow silicon oxide particles (Sururia 1110 manufactured by Nikki Shokubai Kasei Co., Ltd., average particle diameter: about 50 nm, shell thickness: about 10 nm, solid content concentration: 20.5% by mass). Then, a dispersion liquid 16 having a solid content concentration of 3.9% by mass was obtained.

Acid was added to Dispersion 16 such that the ratio of hollow silicon oxide particles to the acid component was 200:1. The added acid is an acid having two acidic groups (Dodecafluorosuberic Acid manufactured by Tokyo Chemical Industry Co., Ltd.).

Furthermore, silica sol 2 was added so that the mass ratio of hollow silicon oxide particles to silica sol component was 100:11. Thereafter, the mixture was mixed and stirred at room temperature for 2 hours to obtain a coating liquid 16 containing hollow silicon oxide particles.

The obtained coating liquid 16 is dropped onto a glass substrate, and after forming a film with a spin coater so that the formed porous layer has a thickness of about 110 nm, it is baked at 140° C. for 30 minutes in a constant temperature furnace. A member 1-16 having a porous layer 20-16 containing particles was obtained. The contact angle of pure water on the surface of the porous layer 20-16 opposite to the substrate was 9°.

[Example 17]
1-propoxy-2-propanol was mixed with 200 g of an isopropyl alcohol dispersion of hollow silicon oxide particles (Sururia 4110 manufactured by Nikki Shokubai Kasei Co., Ltd., average particle diameter: about 60 nm, shell thickness: about 10 nm, solid content concentration: 20.5% by mass). Then, a dispersion liquid 17 having a solid content concentration of 3.9% by mass was obtained.

Acid was added to Dispersion 17 such that the ratio of hollow silicon oxide particles to the acid component was 400:1. The added acid is an acid having two acidic groups (Dodecafluorosuberic Acid manufactured by Tokyo Chemical Industry Co., Ltd.).

Furthermore, silica sol 2 was added so that the mass ratio of hollow silicon oxide particles to silica sol component was 100:11. Thereafter, the mixture was mixed and stirred at room temperature for 2 hours to obtain a coating liquid 17 containing hollow silicon oxide particles.

The obtained coating liquid 16 is dropped onto a glass substrate, and after forming a film with a spin coater so that the formed porous layer has a thickness of about 110 nm, it is baked at 140° C. for 30 minutes in a constant temperature furnace. A member 1-17 having a porous layer 20-17 containing particles was obtained. The contact angle of pure water on the surface of the porous layer 20-17 opposite to the substrate was 10°.

[Example 18]
1-propoxy-2-propanol was added to 400 g of an isopropyl alcohol dispersion of hollow silicon oxide particles (Sururia 4110 manufactured by Nikki Shokubai Kasei Co., Ltd., average particle diameter of about 60 nm, shell thickness of about 10 nm, solid content concentration of 20.5% by mass). While adding, the isopropyl alcohol was distilled off by heating. Isopropyl alcohol was distilled off until the solid concentration reached 19.5% by mass to prepare 420 g of a 1P2P solvent replacement solution for hollow silicon oxide particles (hereinafter referred to as solvent replacement solution 3). An acid was added to the obtained solvent replacement liquid 1 so that the mass ratio of the hollow silicon oxide particles to the acid component was 400:1, and a dispersion liquid 18 was obtained. The added acid is an acid having two acidic groups (Tetrafluorosuccinic Acid, manufactured by Tokyo Chemical Industry Co., Ltd.).

Dispersion 1 was diluted with ethyl lactate so that the solid content concentration was 3.9% by mass, and then silica sol 2 was added so that the ratio of hollow silicon oxide particles to silica sol component was 100:11. Furthermore, a coating liquid 18 containing hollow silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The obtained coating liquid 18 is dropped onto a glass substrate, and after forming a film with a spin coater so that the formed porous layer has a thickness of about 110 nm, it is baked at 140° C. for 30 minutes in a constant temperature furnace. to obtain a member 1-18 having a porous layer 20-18 containing particles. The contact angle of pure water on the surface of the porous layer 20-18 opposite to the substrate was 8°.

[Comparative Example 1]
Dispersion liquid 19 was obtained by adding acid to solvent replacement liquid 2 so that the ratio of the hollow silicon oxide particles to the acid component was 100:1. The added acid is 3,3,3-Trifluoropropionic Acid (manufactured by Tokyo Chemical Industry Co., Ltd., number of acidic groups: 1).

Dispersion 10 was diluted with ethyl lactate so that the solid content concentration was 3.9% by mass, and then silica sol 1 was added so that the mass ratio of hollow silicon oxide particles to silica sol component was 100:12. Furthermore, a coating liquid 19 containing hydrophilic silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The obtained coating liquid 19 is dropped onto a glass substrate, and after forming a film with a spin coater so that the formed porous layer has a thickness of about 110 nm, it is baked at 140° C. for 30 minutes in a constant temperature furnace. to obtain a member 1-19 having a porous layer 20-19 containing particles. The contact angle of pure water on the porous layer 20-19 was 21°.

[Comparative Example 2]
An acid was added to the solvent replacement liquid 1 so that the mass ratio of the hollow silicon oxide particles to the acid component was 100:1, and a dispersion liquid 20 was obtained. The added acid was p-Toluenesulfonic Acid Monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd., number of acidic groups: 1).

Solvent replacement liquid 1 was diluted with ethyl lactate so that the solid content concentration was 3.9% by mass to obtain dispersion liquid 11, and then the mass ratio of hollow silicon oxide particles:silica sol component was 100:12. to which silica sol 2 was added. Furthermore, a coating liquid 20 containing hollow silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The resulting coating liquid 20 is dropped onto a glass substrate, and the resulting porous layer is formed into a film with a spin coater so as to have a thickness of about 110 nm. A member 1-11 having a porous layer 20-20 containing particles was obtained. The contact angle of pure water on the porous layer 20-20 was 13°.

[Comparative Example 3]
Phosphoric acid (manufactured by Tokyo Kasei Kogyo Co., Ltd., number of acidic groups: 1) was added to the solvent replacement liquid 1 so that the mass ratio of the hollow silicon oxide particles to the acid component was 100:1, whereby a dispersion liquid 21 was obtained.

Solvent replacement solution 1 was diluted with ethyl lactate so that the solid content concentration was 3.9% by mass, and then silica sol 1 was added so that the mass ratio of hollow silicon oxide particles to silica sol component was 100:12. . Furthermore, a coating liquid 21 containing hollow silicon oxide particles was obtained by mixing and stirring at room temperature for 2 hours.

The resulting coating liquid 21 is dropped onto a glass substrate, and the resulting porous layer is formed into a film with a spin coater so as to have a thickness of about 110 nm. to obtain a member 1-12 having a porous layer 20-21 containing particles. The contact angle of pure water on the porous layers 20-21 was 15°.

Table 1 shows the evaluation results of Coating Liquids 1 to 21 used in Examples and Comparative Examples, and members 1-1 to 1-21 produced using them.

From the results shown in Table 1, it was found that Examples 1 to 18 could achieve high film strength while maintaining a low refractive index. Also, the scattering value was 25 or less, and it was found that the film had sufficient performance as an optical function film.

On the other hand, in Comparative Examples 1 to 3, the film strength was weak and the scattering showed a high value of 25 or more. From this, in the case of an acid having only one acidic group, it is difficult to maintain a highly dispersed state as the solvent dries during coating film formation. . Moreover, it is presumed that the scattering value was high due to the disordered arrangement.

Although optical members have been mainly described so far, the members according to the present invention can also be used for other purposes. When it is not used as an optical member, it is sufficient that the coating property and film strength are excellent, and there is no need to care about the refractive index and scattering values. For example, it can be used as a heat insulating member or an insulating member.

REFERENCE SIGNS LIST 1 member 10 substrate 20 porous layer 21 silicon oxide particles 22 inorganic binder 23 void 24 acid 30 functional layer 40 intermediate layer

Claims (33)

A member having a porous layer on a substrate,
said porous layer comprising a plurality of silicon oxide particles bound together by an inorganic binder;
At least one acid selected from the group consisting of the following general formulas (1) to (4) ,
When the content of the silicon oxide particles in the porous layer is 100 parts by mass, the content of the inorganic binder in the porous layer is 5 parts by mass or more and 20 parts by mass or less. material to be used.

COOH is selected for _A1 in the formula (1). n is an integer from 2 to 8;
One of A ₂ and A ₃ in formula (2) is SO ₃ H or PO ₃ H ₂ and the other is an acidic group selected from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. A divalent organic group having 1 to 20 carbon atoms is selected for R.
At least one of A ₂ , A ₃ and A ₄ in formula (3) is SO ₃ H or PO ₃ H ₂ and the rest are each from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. It is the acidic group of choice. A trivalent organic group having 1 to 20 carbon atoms is selected for R.
At least one of A ₂ , A ₃ , A ₄ and A ₅ in formula (4) is SO ₃ H or PO ₃ H ₂ and each of the remaining is SO ₃ H, PO ₃ H ₂ , COOH, OH It is an acidic group selected from the group consisting of A tetravalent organic group having 1 to 20 carbon atoms is selected for R. 2. The member according to claim 1, wherein said silicon oxide particles are hollow silicon oxide particles or chain silicon oxide particles. 3. The member according to claim 2, wherein the silicon oxide particles are hollow silicon oxide particles, and the average particle diameter of the hollow silicon oxide particles is 15 nm or more and 300 nm or less. The silicon oxide particles are chain-shaped silicon oxide particles, and the primary particles constituting the chain-shaped silicon oxide particles have a minor axis of 8 nm or more and 20 nm or less and a major axis of 1.5 to 3.0 times the minor axis. 3. The member according to claim 2, wherein the particles are: 5. The member according to any one of claims 1 to 4, wherein the inorganic binder is a silicon oxide compound. The member according to any one of claims 1 to 5, wherein the porous layer has a refractive index of 1.20 or more and 1.30 or less. 7. The member according to any one of claims 1 to 6, wherein the contact angle of pure water on the surface of the porous layer opposite to the substrate is 3° or more and 20° or less. 8. The member according to any one of claims 1 to 7, further comprising an intermediate layer between the substrate and the porous layer. 9. The member according to claim 8, wherein the intermediate layer includes an inorganic compound layer or a polymer layer. 10. The intermediate layer according to claim 8, wherein the intermediate layer is a layer in which a high refractive index layer having a relatively high refractive index and a low refractive index layer having a relatively low refractive index are alternately laminated. member of. 11. The member according to any one of claims 1 to 10, further comprising a functional layer on the surface of the porous layer opposite to the substrate. 12. The method according to claim 11, wherein the functional layer is an antifouling layer, and the antifouling layer is any one of a layer containing a fluoropolymer, a fluorosilane monomolecular layer, and a layer containing titanium oxide particles. member of. 12. The member according to claim 11, wherein the functional layer is a hydrophilic layer, and the hydrophilic layer is a layer containing a polymer having a zwitterionic hydrophilic group. 14. The member according to any one of claims 1 to 13 , wherein the porous layer has voids between the plurality of silicon oxide particles . An optical device comprising a housing and an optical system comprising a plurality of lenses in the housing,
An optical instrument, wherein the lens is the member according to any one of claims 1 to 14. An imaging device comprising a housing, an optical system including a plurality of lenses in the housing, and an imaging device that receives light that has passed through the optical system,
An imaging device, wherein the lens is the member according to any one of claims 1 to 14. A lens filter comprising a frame and a filter portion supported by the frame,
The filter part has a base material and a porous layer on the base material,
said porous layer comprising a plurality of silicon oxide particles bound together by an inorganic binder;
At least one acid selected from the group consisting of the following general formulas (1) to (4) ,
When the content of the silicon oxide particles in the porous layer is 100 parts by mass, the content of the inorganic binder in the porous layer is 5 parts by mass or more and 20 parts by mass or less. lens filter.

COOH is selected for _A1 in the formula (1). n is an integer from 2 to 8;
One of A ₂ and A ₃ in formula (2) is SO ₃ H or PO ₃ H ₂ and the other is an acidic group selected from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. A divalent organic group having 1 to 20 carbon atoms is selected for R.
At least one of A ₂ , A ₃ and A ₄ in formula (3) is SO ₃ H or PO ₃ H ₂ and the rest are each from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. It is the acidic group of choice. A trivalent organic group having 1 to 20 carbon atoms is selected for R.
At least one of A ₂ , A ₃ , A ₄ and A ₅ in formula (4) is SO ₃ H or PO ₃ H ₂ and each of the remaining is SO ₃ H, PO ₃ H ₂ , COOH, OH It is an acidic group selected from the group consisting of: A tetravalent organic group having 1 to 20 carbon atoms is selected for R. A shield comprising a translucent member and a holding member that holds the translucent member,
the holding member has a structure for fixing the light-transmitting member to the user so that the light-transmitting member covers at least part of the user's face;
The light-transmitting member has a base material and a porous layer on the base material,
said porous layer comprising a plurality of silicon oxide particles bound together by an inorganic binder;
At least one acid selected from the group consisting of the following general formulas (1) to (4) ,
When the content of the silicon oxide particles in the porous layer is 100 parts by mass, the content of the inorganic binder in the porous layer is 5 parts by mass or more and 20 parts by mass or less. Shield to do.

COOH is selected for _A1 in the formula (1). n is an integer from 2 to 8;
One of A ₂ and A ₃ in formula (2) is SO ₃ H or PO ₃ H ₂ and the other is an acidic group selected from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. A divalent organic group having 1 to 20 carbon atoms is selected for R.
At least one of A ₂ , A ₃ and A ₄ in formula (3) is SO ₃ H or PO ₃ H ₂ and the rest are each from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. It is the acidic group of choice. A trivalent organic group having 1 to 20 carbon atoms is selected for R.
At least one of A ₂ , A ₃ , A ₄ and A ₅ in formula (4) is SO ₃ H or PO ₃ H ₂ and each of the remaining is SO ₃ H, PO ₃ H ₂ , COOH, OH It is an acidic group selected from the group consisting of: A tetravalent organic group having 1 to 20 carbon atoms is selected for R. A coating liquid,
Silicon oxide particles, an inorganic binder component, an organic solvent, and at least one acid selected from the group consisting of the following general formulas (1) to (4),
A coating liquid, wherein the content of the component serving as the inorganic binder is 0.2 parts by mass or more and 20 parts by mass or less when the content of the silicon oxide particles is 100 parts by mass.

COOH is selected for _A1 in the formula (1). n is an integer from 2 to 8;
One of A ₂ and A ₃ in formula (2) is SO ₃ H or PO ₃ H ₂ and the other is an acidic group selected from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. A divalent organic group having 1 to 20 carbon atoms is selected for R.
At least one of A ₂ , A ₃ and A ₄ in formula (3) is SO ₃ H or PO ₃ H ₂ and the rest are each from the group consisting of SO ₃ H, PO ₃ H ₂ , COOH and OH. It is the acidic group of choice. A trivalent organic group having 1 to 20 carbon atoms is selected for R.
At least one of A ₂ , A ₃ , A ₄ and A ₅ in formula (4) is SO ₃ H or PO ₃ H ₂ and each of the remaining is SO ₃ H, PO ₃ H ₂ , COOH, OH It is an acidic group selected from the group consisting of: A tetravalent organic group having 1 to 20 carbon atoms is selected for R. 20. The coating liquid according to claim 19, wherein the content of the acid is 0.05 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the silicon oxide particles. 21. The coating liquid according to claim 20, wherein the content of the acid is 0.1 parts by mass or more and 2.0 parts by mass or less with respect to 100 parts by mass of the silicon oxide particles. The coating liquid according to any one of claims 19 to 21, wherein the acid has an acid dissociation constant of -1.2 pKa or more and 2 pKa or less. The coating liquid according to claim 22, wherein the acid has an acid dissociation constant of -1.2 pKa or more and 0.3 pKa or less. 24. The coating liquid according to any one of claims 19 to 23, wherein the silicon oxide particles are wet silicon oxide particles. 25. The coating liquid according to any one of claims 19 to 24, wherein the silicon oxide particles are hollow silicon oxide particles or chain silicon oxide particles. 26. The coating liquid according to claim 25, wherein the silicon oxide particles are hollow silicon oxide particles, and the average particle size of the hollow silicon oxide particles is 15 nm or more and 300 nm or less. 3. The silicon oxide particles are chain silicon oxide particles, and the chain silicon oxide particles have an average minor axis of 8 nm or more and 20 nm or less, and a major axis of which is 4 times or more and 8 times or less of the minor axis. 25. The coating liquid according to 25 above. 28. The method according to claim 27, wherein the primary particles constituting the chain-like silicon oxide particles are particles having a short diameter of 8 nm or more and 20 nm or less and a long diameter of 1.5 times or more and 3.0 times or less of the short diameter. coating liquid. 29. The coating liquid according to any one of claims 19 to 28, wherein the component that serves as the inorganic binder is a silicon oxide oligomer. The coating liquid according to any one of claims 19 to 29, wherein 30% by mass or more of the solvent is a water-soluble solvent having a hydroxyl group having 4 to 6 carbon atoms. The solvent is ethoxyethanol, propoxyethanol, isopropoxyethanol, butoxyethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-propoxy-2-propanol, ethyl lactate, 3-methoxy-1- The coating liquid according to claim 30, comprising at least one solvent selected from the group consisting of butanol. a step of applying a coating liquid onto a substrate; and a step of drying and/or baking the substrate coated with the coating liquid,
A method of manufacturing a member, wherein the coating liquid is the coating liquid according to any one of claims 19 to 31. 33. The method of manufacturing a member according to claim 32, wherein in the step of applying the coating liquid onto the substrate, the coating liquid is applied by a spin coating method.

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