Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
  • C09D7/40—Additives
  • C09D7/70—Additives characterised by shape, e.g. fibres, flakes or microspheres
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/001—General methods for coating; Devices therefor
  • C03C17/002—General methods for coating; Devices therefor for flat glass, e.g. float glass
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/006—Surface treatment of glass, not in the form of fibres or filaments, by coating with materials of composite character
  • C03C17/007—Surface treatment of glass, not in the form of fibres or filaments, by coating with materials of composite character containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/02—Surface treatment of glass, not in the form of fibres or filaments, by coating with glass
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/28—Surface treatment of glass, not in the form of fibres or filaments, by coating with organic material
  • C03C17/30—Surface treatment of glass, not in the form of fibres or filaments, by coating with organic material with silicon-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/34—Silicon-containing compounds
  • C08K3/36—Silica
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K7/00—Use of ingredients characterised by shape
  • C08K7/22—Expanded, porous or hollow particles
  • C08K7/24—Expanded, porous or hollow particles inorganic
  • C08K7/26—Silicon- containing compounds
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
  • C09D7/40—Additives
  • C09D7/60—Additives non-macromolecular
  • C09D7/61—Additives non-macromolecular inorganic
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
  • G02B1/11—Anti-reflection coatings
  • G02B1/111—Anti-reflection coatings using layers comprising organic materials
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/40—Coatings comprising at least one inhomogeneous layer
  • C03C2217/42—Coatings comprising at least one inhomogeneous layer consisting of particles only
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/40—Coatings comprising at least one inhomogeneous layer
  • C03C2217/425—Coatings comprising at least one inhomogeneous layer consisting of a porous layer
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/40—Coatings comprising at least one inhomogeneous layer
  • C03C2217/43—Coatings comprising at least one inhomogeneous layer consisting of a dispersed phase in a continuous phase
  • C03C2217/46—Coatings comprising at least one inhomogeneous layer consisting of a dispersed phase in a continuous phase characterized by the dispersed phase
  • C03C2217/47—Coatings comprising at least one inhomogeneous layer consisting of a dispersed phase in a continuous phase characterized by the dispersed phase consisting of a specific material
  • C03C2217/475—Inorganic materials
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2218/00—Methods for coating glass
  • C03C2218/10—Deposition methods
  • C03C2218/11—Deposition methods from solutions or suspensions
  • C03C2218/112—Deposition methods from solutions or suspensions by spraying

Definitions

• the present invention relates to a method for producing a transparent porous film.
• Such a transparent porous film is manufactured, for example, by coating a base material with a silicone sol paint containing a pulverized product of a gel-like silicon compound and a dispersion medium (see, for example, Patent Document 1).
• a transparent porous film has been manufactured by die coating on a long base material from the viewpoint of manufacturing efficiency, and has been used by being attached to an optical member after peeling from the base material.
• the uses of optical products have diversified, and it is being considered to form transparent porous films directly on optical members.
• optical members can have various shapes (irregular shapes, chip shapes, etc.) depending on their use, it is desirable to spray paint onto an object to form a transparent porous film.
• the silicone sol paint described in Patent Document 1 is used for spray coating, the transparency of the transparent porous film may be reduced, or the accuracy of the thickness of the transparent porous film may be reduced.
• the present invention has been made to solve the above-mentioned conventional problems, and its main purpose is to provide a transparent porous film that can be manufactured by spray coating to have excellent transparency and thickness accuracy.
• the purpose of this invention is to provide a method for manufacturing the same.
• a method for manufacturing a transparent porous film according to an embodiment of the present invention is to prepare a transparent porous-forming paint containing particles and a dispersion medium in which the particles are dispersed such that the solid content concentration change rate satisfies the following formula (1). , includes the step of spray coating a substrate to form a coating film.
• the solid content concentration change rate indicates the solid content concentration in the coating film at 10 seconds after spray coating with respect to the solid content concentration in the transparent porous forming paint before spray coating.
• the solid content concentration in the transparent porous-forming paint before the spray coating is 0.1% by mass to 6.0% by mass
• the solid content concentration in the coating film at 10 seconds after the spray coating is The minute concentration is 3.7% by mass to 6.5% by mass.
• the viscosity of the coating film 10 seconds after the spray coating satisfies the following formula (2).
• the dispersion medium includes a first dispersion medium having a boiling point of less than 150°C.
• the content of the first dispersion medium in the dispersion medium is 30% by mass to 100% by mass.
• the particles are porous particles of silicon compounds.
• a transparent porous film having excellent transparency and excellent thickness accuracy can be manufactured by spray coating.
• a method for manufacturing a transparent porous film in one embodiment of the present invention includes a transparent porous-forming coating material containing particles and a dispersion medium in which the particles are dispersed.
• the method includes a step of spray coating a substrate to form a coating film such that the ratio satisfies the following formula (1).
• 1.3 ⁇ Solid content concentration change rate ⁇ 60...(1) In formula (1), the solid content concentration change rate indicates the solid content concentration in the coating film at 10 seconds after spray coating with respect to the solid content concentration in the transparent porous forming paint before spray coating.)
• the state of the coating film formed on the base material can be stabilized.
• the solid content concentration change rate is preferably 1.5 or more and 55 or less.
• the solid content concentration in the transparent porous forming paint before spray coating is, for example, 0.1% by mass or more, preferably 1.0% by mass or more, more preferably 2.0% by mass or more, for example 6.0% by mass. % or less, preferably 3.5% by mass or less.
• the solid content concentration in the coating film 10 seconds after spray coating is the solid content concentration in the coating film 10 seconds after the spraying of the paint from the spray head stops, and is, for example, 3.7% by mass or more, preferably 4% by mass. .5% by mass or more, for example, 6.5% by mass or less.
• These solid content concentrations can be measured, for example, by spraying onto a substrate and measuring the change in mass before and after drying.
• the viscosity [mPa ⁇ s] of the coating film at 10 seconds after spray coating satisfies the following formula (2).
• 0.0549e 1.2x ⁇ Viscosity of coating film at 10 seconds after spray coating ⁇ 0.0549e 3.3x ...(2)
• e represents Napier's number
• x represents the solid content concentration in the coating film at 10 seconds after spray coating.
• the transparent porous forming paint contains particles; and a dispersion medium in which the particles are dispersed.
• Particles Particles are composed of any material suitable for making transparent porous films.
• the material constituting the particles for example, the materials described in International Publication No. 2004/113966, JP 2013-254183, JP 2012-189802, and JP 2017-25277 are adopted. obtain.
• the material can be both inorganic and organic.
• inorganic substances constituting the particles include silicon compounds containing Si, magnesium compounds containing Mg, aluminum compounds containing Al, titanium compounds containing Ti, zinc compounds containing Zn, and zirconium compounds containing Zr. can be mentioned.
• organic substances constituting the particles include organic polymers; polymerizable monomers (such as (meth)acrylic monomers and styrene monomers); curable resins (such as (meth)acrylic resins, fluorine-containing resins, and urethane). resin).
• polymerizable monomers such as (meth)acrylic monomers and styrene monomers
• curable resins such as (meth)acrylic resins, fluorine-containing resins, and urethane). resin).
• the materials constituting these particles can be used alone or in combination.
• inorganic materials are preferred, and silicon compounds are more preferred.
• silicon compounds include silica-based compounds; hydrolyzable silanes, and their partial hydrolysates and dehydrated condensates; silicon compounds containing silanol groups; The activated silica obtained can be mentioned.
• silicon compounds silicon compounds containing silanol groups are preferred.
• the shape of the "particles" is not particularly limited, and may be, for example, spherical or other shapes.
• the particles may adopt any suitable shape.
• Examples of the shape of the particles include spherical, plate-like, needle-like, string-like, and grape-like shapes.
• String-like particles include, for example, particles in which a plurality of particles having a spherical, plate-like, or needle-like shape are connected in a beaded manner, short fiber-like particles (for example, particles described in Japanese Patent Application Laid-open No. 2001-188104) short fibrous particles), and combinations thereof.
• the string-shaped particles may be linear or branched.
• Examples of grape cluster-shaped particles include particles in which a plurality of spherical, plate-shaped, and needle-shaped particles are aggregated to form a cluster of grapes.
• the shape of the particles can be confirmed, for example, by observing with a transmission electron microscope.
• the particles preferably have voids (pores). More preferably, the particles include hollow particles (hollow nanosilica/nanoballoon particles) and porous particles, and even more preferably porous particles.
• the particles are porous particles of silicon compounds. According to such a configuration, a transparent porous film having desired optical properties can be stably manufactured.
• the porous particles of a silicon compound are preferably pulverized gel-like silicon compounds obtained by pulverizing a gel-like silicon compound in a medium (typically a hydrophilic medium). The crushed body will be explained in detail later.
• the volume average particle diameter of the particles is, for example, 0.05 ⁇ m or more, preferably 0.10 ⁇ m or more, more preferably 0.20 ⁇ m or more, and even more preferably 0.40 ⁇ m. For example, it is 2.00 ⁇ m or less, preferably 1.50 ⁇ m or less, and more preferably 1.00 ⁇ m or less.
• the volume average particle diameter indicates the particle size variation of the particles (pulverized material) in the transparent porous forming paint, and can be measured using particle size distribution evaluation devices such as dynamic light scattering, laser diffraction, and scanning electron microscopy (SEM). It can be measured using an electron microscope such as a transmission electron microscope (TEM).
• the particle size distribution of the particles includes particles having a particle size of 0.4 ⁇ m to 1 ⁇ m, for example, 50% by mass to 99.9% by mass, preferably 80% by mass to 99.9% by mass. 8% by weight, more preferably 90% to 99.7% by weight, and particles with a particle size of 1 ⁇ m to 2 ⁇ m, for example 0.1% to 50% by weight, preferably 0.2% to 20% by weight. , more preferably 0.3% by mass to 10% by mass.
• Particle size distribution indicates the particle size variation of particles (pulverized material) in a transparent porous coating material, and can be measured using, for example, a particle size distribution evaluation device or an electron microscope.
• the content ratio of such particles is adjusted so that the solid content concentration in the transparent porous coating material before spray coating falls within the above range.
• the content of the particles is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and, for example, 50 parts by mass or less, preferably 30 parts by mass or less, based on 100 parts by mass of the dispersion medium.
• the concentration of particles in the transparent porous coating is, for example, 0.1% by mass or more, preferably 1.0% by mass or more, more preferably 2.0% by mass or more, and, for example, 6.0% by mass or less, preferably It is 3.5% by mass or less.
• the dispersion medium has any suitable composition capable of dispersing the particles.
• the dispersion medium typically includes a first dispersion medium having a boiling point of less than 150°C.
• the boiling point of the first dispersion medium is the boiling point under 1 atmosphere, and is preferably 130°C or lower, more preferably 110°C or lower, and, for example, 80°C or higher, preferably 90°C or higher.
• the first dispersion medium examples include alcohols such as ethanol, isopropyl alcohol, butanol, t-butanol, isobutyl alcohol, and 2-methoxyethanol (methyl cellosolve); esters such as ethyl acetate and butyl acetate; diisopropyl ether, propylene glycol Examples include ethers such as monomethyl ether; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and aromatic hydrocarbons such as toluene. These first dispersion media can be used alone or in combination. Among these first dispersion media, alcohols are more preferred, and isobutyl alcohol is even more preferred.
• the content ratio of the first dispersion medium in the dispersion medium is, for example, 5% by mass or more, preferably 30% by mass or more, more preferably 40% by mass or more, and, for example, 100% by mass or less, preferably 95% by mass or less, more preferably is 60% by mass or less.
• the viscosity of the transparent porous coating material can be stably adjusted to a range suitable for spray coating.
• the dispersion medium may consist of only the first dispersion medium, or may contain a second dispersion medium in addition to the first dispersion medium.
• the dispersion medium includes, in addition to the first dispersion medium described above, a second dispersion medium having a boiling point of 150° C. or higher.
• the boiling point of the second dispersion medium is preferably 155°C or higher, more preferably 165°C or higher, and, for example, 200°C or lower, preferably 190°C or lower.
• Examples of the second dispersion medium include dimethyl sulfoxide (DMSO); esters such as ethylene glycol monoethyl ether acetate and ethyl lactate; diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, and diethylene glycol diethyl ether.
• DMSO dimethyl sulfoxide
• esters such as ethylene glycol monoethyl ether acetate and ethyl lactate
• diethylene glycol ethyl methyl ether diethylene glycol dimethyl ether
• dipropylene glycol dimethyl ether dipropylene glycol monomethyl ether
• diethylene glycol diethyl ether diethylene glycol diethyl ether.
• diethylene glycol monomethyl ether diethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, ethylene glycol monophenyl ether, triethylene glycol monomethyl ether, diethylene glycol dibutyl ether, triethylene glycol butyl methyl ether, polyethylene glycol dimethyl ether , tetraethylene glycol dimethyl ether, polyethylene glycol monomethyl ether;
• These second dispersion media can be used alone or in combination.
• esters and ethers are preferred, and diethylene glycol ethyl methyl ether is more preferred.
• the content of the second dispersion medium in the dispersion medium is, for example, 0% by mass or more, preferably 5% by mass or more, more preferably 40% by mass or more, and, for example, 95% by mass or less, preferably 70% by mass or more. It is not more than 60% by mass, more preferably not more than 60% by mass. According to such a configuration, the viscosity of the transparent porous coating material can be stably adjusted to a range suitable for spray coating, and the transparency of the transparent porous film produced by spray coating can be further improved.
• the method for producing a transparent porous coating includes the steps of pulverizing a material to be pulverized in a hydrophilic medium to prepare a sol in which particles are dispersed in the hydrophilic medium; and replacing the dispersion medium with a dispersion medium and adjusting the concentration of particles within the above range. By replacing the solvent after pulverizing the material to be pulverized in this manner, the dispersibility of the particles can be maintained.
• a material to be crushed that becomes a raw material for particles is prepared.
• the method for preparing the material to be crushed include the method described in JP-A No. 2017-25277. The entire description of this publication is incorporated herein by reference.
• a precursor of the above particle material typically a silicon compound
• a hydrophilic medium include isopropyl alcohol (IPA), ethanol, methanol, butanol, acetone, dimethylformamide (DMF), and dimethyl sulfoxide (DMSO), preferably IPA and DMSO.
• Hydrophilic media can be used alone or in combination.
• the hydrophilic medium may be mixed with water.
• a material to be crushed (typically a gel-like silicon compound) composed of the above-mentioned particle material is prepared.
• the material to be crushed (typically a gelled silicon compound) is aged in a hydrophilic medium at, for example, 20° C. to 50° C. for 10 hours or more.
• the material to be ground (typically a gelled silicon compound) is ground in a hydrophilic medium by any suitable method.
• the hydrophilic medium may be a mixed medium mixed with water.
• the pulverization method is not particularly limited, and when the object to be pulverized is a gel-like silicon compound, a high-pressure medirealess method using a homogenizer is preferably used. As a result, a sol liquid in which the above particles are dispersed in a hydrophilic medium is prepared.
• the hydrophilic medium contained in the sol liquid is replaced with the above-mentioned dispersion medium by any appropriate method.
• the method for replacing the solvent is not particularly limited, and examples thereof include decantation, cross-flow filtration, and dynamic filtering. These substitution methods are preferably performed multiple times. Note that, if necessary, the concentration of particles is adjusted within the above range using the above-mentioned dispersion medium.
• the hydrophilic medium is a mixed medium mixed with water
• a hydrophilic medium typically, an alcohol having 3 or less carbon atoms
• the hydrophilic medium is replaced with the above-mentioned hydrophilic medium. It may be replaced with a dispersion medium.
• a transparent porous coating material containing the particles and the dispersion medium is manufactured.
• the above-described transparent porous coating can be suitably used for spray coating.
• the transparent porous-forming paint described above is sprayed onto a base material (typically, an optical member such as an optical film) as an object to form a coating film on the base material.
• the shape of the base material is not particularly limited. Examples of the shape when viewed from the thickness direction of the base material include polygonal shapes such as rectangles; circular shapes; elliptical shapes; and irregular shapes having concave portions and/or convex portions.
• the surface shape of the base material is also not particularly limited.
• the substrate is spray coated such that the rate of change in solid content concentration of the transparent porous coating material satisfies the above formula (1).
• the viscosity [mPa ⁇ s] of the coating film at 10 seconds after spray coating satisfies the above formula (2).
• the viscosity of the coating film at 10 seconds after spray coating is specifically 30 mPa ⁇ s or more, preferably 100 mPa ⁇ s or more, more preferably 300 mPa ⁇ s or more, still more preferably 400 mPa ⁇ s or more, particularly preferably 500 mPa ⁇ s. ⁇ s or more, for example, 4500 mPa ⁇ s or less, preferably 3000 mPa ⁇ s or less, more preferably 1000 mPa ⁇ s or less, particularly preferably 700 mPa ⁇ s or less. If the viscosity of the coating film is within the above range, the transparency and thickness accuracy of the transparent porous film can be further improved.
• the viscosity of the transparent porous coating before spray coating is, for example, 0.1 mPa ⁇ s or more, preferably 1.0 mPa ⁇ s or more, and is, for example, 2000 mPa ⁇ s or less, preferably 200 mPa ⁇ s or less. These viscosities can be calculated using a rheometer manufactured by Anton-Paar.
• the distance between the spray head that sprays the transparent porous-forming paint and the substrate can be adjusted as appropriate. As the distance between the spray head and the substrate increases, the rate of change in solids concentration may increase, and as the distance between the spray head and the substrate decreases, the rate of change in solids concentration may decrease.
• the distance between the spray head and the substrate (coating distance) is, for example, 50 mm or more, preferably 100 mm or more, and, for example, 500 mm or less, preferably 300 mm or less.
• the transparent porous-forming paint in spray coating, is sprayed while the spray head moves in the surface direction of the base material.
• the atomization pressure for spray coating is, for example, 100 kPa to 1000 kPa
• the coating amount for spray coating is, for example, 0.1 mL/min to 20 mL/min
• the moving speed of the spray head during spraying is, for example, 1 mm/min. seconds to 1000 mm/second.
• a coating film is formed on the base material, which forms a void structure that is a precursor of a porous layer (void layer).
• void layer a porous layer
• the particles are pulverized gel-like compounds.
• a coating film can be formed in the same way.
• the reason why a suitable void structure is formed in the coating film when the particles are pulverized gel-like compounds is presumed to be as follows, for example. However, this assumption does not limit the method of forming the transparent porous film.
• the three-dimensional structure of the gel-like silicon compound before pulverization is in a state where it is dispersed into a three-dimensional basic structure. Furthermore, in the above method, a precursor having a porous structure based on a three-dimensional basic structure is formed by spray coating a crushed product of a gel-like silicon compound onto a base material. That is, according to the above method, a new porous structure (three-dimensional basic structure) different from the three-dimensional structure of the gel-like silicon compound is formed by spray coating the pulverized material. Therefore, the finally obtained transparent porous film can have a low refractive index that functions to the same extent as, for example, an air layer.
• the method for producing a transparent porous film further includes the step of heating and drying the coating film on the substrate.
• the heating temperature is, for example, 60°C or higher, preferably 70°C or higher, more preferably 80°C or higher, and is, for example, 200°C or lower, preferably 120°C or lower, more preferably 100°C or lower.
• the heating time is not particularly limited as long as the coating film can be sufficiently dried.
• a crosslinking reaction occurs between a plurality of particles included in the coating film. Therefore, the three-dimensional basic structure is fixed. As a result, the finally obtained transparent porous film can maintain sufficient strength and flexibility despite having a structure having voids.
• a transparent porous film is formed on the base material.
• the transparent porous film may be, for example, an open-cell structure with a continuous pore structure.
• An open cell structure means that the pore structure is three-dimensionally connected, and can also be said to be a state in which the internal voids of the pore structure are continuous. Since the transparent porous film has an open cell structure, it is possible to increase the porosity.
• the transparent porous film more preferably has a monolith structure in which the open cell structure includes a plurality of pore distributions.
• the monolith structure means, for example, a hierarchical structure including a structure in which nano-sized fine voids exist and an open cell structure in which the nano-sized voids are assembled. When forming a monolith structure, for example, fine voids provide membrane strength while coarse open voids provide high porosity, making it possible to achieve both membrane strength and high porosity.
• the transparent porous film may preferably be a nanoporous film (specifically, a transparent porous film in which the diameter of 90% or more of the micropores is within the range of 10 ⁇ 1 nm to 10 3 nm).
• the porosity of the transparent porous film is, for example, more than 10 vol%, preferably 20 vol% or more, more preferably 30 vol% or more, even more preferably 35 vol% or more, and, for example, 60 vol% or less, preferably The content is 55% by volume or less, more preferably 50% by volume or less, even more preferably 45% by volume or less.
• the porosity is a value calculated by Lorentz-Lorenz's formula from the refractive index value measured with an ellipsometer.
• the size of the voids (pores) in the transparent porous film refers to the diameter of the major axis of the major axis and the diameter of the minor axis of the voids (pores).
• the size of the voids (pores) is, for example, 2 nm to 500 nm.
• the size of the voids (pores) is, for example, 2 nm or more, preferably 5 nm or more, more preferably 10 nm or more, and still more preferably 20 nm or more.
• the size of the voids (pores) is, for example, 500 nm or less, preferably 200 nm or less, and more preferably 100 nm or less.
• the size range of the voids (pores) is, for example, 2 nm to 500 nm, preferably 5 nm to 500 nm, more preferably 10 nm to 200 nm, and even more preferably 20 nm to 100 nm.
• the size of the voids (pores) can be adjusted to a desired size depending on the purpose and use.
• the size of the voids can be quantified by the BET test method. Specifically, 0.1 g of the sample (formed void layer) was put into the capillary of a specific surface area measurement device (manufactured by Micromeritics: ASAP2020), and then dried under reduced pressure at room temperature for 24 hours to remove the voids. To evacuate gases within the structure. Then, by adsorbing nitrogen gas onto the sample, an adsorption isotherm is drawn and the pore distribution is determined. This allows the void size to be evaluated.
• a specific surface area measurement device manufactured by Micromeritics: ASAP2020
• the refractive index of the transparent porous film is, for example, 1.25 or less, preferably less than 1.20, more preferably 1.19 or less, even more preferably 1.18 or less, and typically 1.10 or more. .
• the refractive index refers to a refractive index measured at a wavelength of 550 nm, unless otherwise specified.
• Transparent porous films have excellent transparency.
• the total light transmittance of the transparent porous film is, for example, 85% to 99%, preferably 87% to 98%, more preferably 89% to 97%.
• the haze of the transparent porous film is, for example, less than 5%, preferably less than 3%, more preferably less than 1%. On the other hand, the haze is, for example, 0.1% or more.
• Haze can be measured, for example, by the following method.
• the transparent porous film is cut into a size of 50 mm x 50 mm, and the film is set in a haze meter (HM-150, manufactured by Murakami Color Research Institute) to measure the haze.
• the haze value is calculated using the following formula.
• Haze (%) [diffuse transmittance (%) / total light transmittance (%)] ⁇ 100 (%)
• the average thickness of the transparent porous film is, for example, 30 nm to 5 ⁇ m, preferably 200 nm to 4 ⁇ m, more preferably 400 nm to 3 ⁇ m, and even more preferably 600 nm to 2 ⁇ m.
• the transparent porous film can effectively exhibit a total reflection function for light in the visible to infrared region.
• the transparent porous film has excellent thickness accuracy.
• the thickness unevenness of the transparent porous film is, for example, ⁇ 300 nm or less, preferably ⁇ 100 nm or less, and more preferably ⁇ 80 nm or less.
• the thickness unevenness of the transparent porous film can be measured using, for example, an Optical NanoGauge film thickness meter manufactured by Hamamatsu Photonics.
• the transparent porous film of this embodiment is composed of one or more types of structural units that form a fine pore structure, and the structural units are chemically bonded to each other through catalytic action.
• Examples of the shape of the structural unit include particulate, fibrous, rod-like, and plate-like shapes.
• a structural unit may have only one shape or a combination of two or more shapes. In the following, a case will be mainly described in which the transparent porous film is a void layer of a porous body in which the particles are chemically bonded to each other.
• Such a transparent porous film can be formed by, for example, chemically bonding particles together in the drying step.
• the transparent porous film includes pulverized gel-like compounds, and the pulverized materials are chemically bonded to each other.
• the form of chemical bonding (chemical bonding) between the pulverized materials in the transparent porous film is not particularly limited, and examples thereof include crosslinking, covalent bonding, and hydrogen bonding.
• a pulverized product of a gel-like silicon compound since the particles have a three-dimensional dendritic structure, the dendritic particles are By settling and depositing, it is possible to easily form an open cell structure.
• a monolith structure can be formed by controlling the particle size distribution of the particles after pulverization to a desired size, for example, when pulverizing a gel-like silicon compound.
• the silicon atoms contained therein are bonded with siloxane.
• the proportion of unbonded silicon atoms (that is, residual silanol) among all silicon atoms contained in the void layer is, for example, less than 50%, preferably 30% or less, and more preferably 15%. It is as follows.
• Solid content concentration at the time of coating (solid content concentration in the coating film at 10 seconds after spray coating) was calculated using the following formula (3). The results are shown in Table 1.
• the mass after drying means the mass after continuing to dry the coating film on a base material at 90 degreeC until the mass change by solvent volatilization disappears.
• the pulverization process uses a homogenizer (manufactured by SMT Co., Ltd., trade name "UH-50"), and 1.85 g of the gel compound in mixture C and IPA are added in a 5 cc screw bottle. After weighing 15 g, it was pulverized for 2 minutes at 50 W and 20 kHz. By this pulverization treatment, the gel-like silicon compound in the mixed liquid C was pulverized, so that the mixed liquid C became a sol liquid D of the pulverized product.
• a homogenizer manufactured by SMT Co., Ltd., trade name "UH-50”
• the dispersion medium shown in Table 1 was added to the sol solution D of the pulverized product, and after stirring lightly, the mixture was allowed to stand at room temperature (23° C.) for 6 hours, and the dispersion medium and catalyst in the gel were decanted. The solvent was replaced by performing the same decantation treatment three times. Through the above steps, a transparent porous coating material was obtained.
• Table 1 shows the concentration of the pulverized material (particle concentration) in the paint.
• the volume average particle size which indicates the particle size variation of the crushed material contained in the paint, was confirmed using a dynamic light scattering nanotrack particle size analyzer (manufactured by Nikkiso Co., Ltd., model UPA-EX150), and it was found to be 0.50 to 0. It was 70.
• Coating conditions atomization pressure 100 kPa, coating amount 7 mL/min, head speed 300 mm/sec in the first step, head movement distance 15 mm in the second step.
• the coating film on the alkali-free glass was dried at 90°C for 10 minutes, and then at 70°C for 24 hours.
• a transparent porous film was formed.
• the average thickness of the transparent porous film was 1.00 ⁇ m, and the refractive index of the transparent porous film was 1.18.
• IBA Isobutyl alcohol, manufactured by Tokyo Chemical Industry Co., Ltd.
• EDM Diethylene glycol ethyl methyl ether, manufactured by Toho Chemical Industry Co., Ltd.
• the transparent porous film produced by the method for producing a transparent porous film according to the embodiment of the present invention can be suitably used for various optical products.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Wood Science & Technology (AREA)
• Physics & Mathematics (AREA)
• Polymers & Plastics (AREA)
• Medicinal Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Inorganic Chemistry (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Dispersion Chemistry (AREA)
• Composite Materials (AREA)
• Application Of Or Painting With Fluid Materials (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=88202036

Family Applications (1)

Country Status (6)

Citations (5)

Family Cites Families (1)

• 2023
  • 2023-03-23 JP JP2024512264A patent/JPWO2023190022A1/ja active Pending
  • 2023-03-23 CN CN202380025978.0A patent/CN118829905A/zh active Pending
  • 2023-03-23 WO PCT/JP2023/011475 patent/WO2023190022A1/ja not_active Ceased
  • 2023-03-23 US US18/848,898 patent/US20250214887A1/en active Pending
  • 2023-03-23 KR KR1020247029716A patent/KR20240169612A/ko active Pending
  • 2023-03-28 TW TW112111797A patent/TW202348701A/zh unknown

Patent Citations (5)

Also Published As

Similar Documents

Legal Events