Silicon compound-containing liquid, silicon compound-containing material, and production methods for these

Abstract

A silicon compound-containing liquid according to the present invention contains a silicon compound and water, wherein maximum transmittance in the wavelength range of 400-900 nm, as determined by means of an ultraviolet-visible spectrophotometer, is not less than 60%T. A production method for a silicon compound-containing liquid according to the present invention comprises: a mixing step for adding an acidic aqueous solution to a starting material substance containing silicon, performing stirring at 15-50°C, and obtaining a liquid mixture containing a precursor of a silicon compound; and a stirring step for adding, to the liquid mixture, a solution containing an organic nitrogen compound, performing stirring at 15-50°C, and generating a silicon compound-containing liquid.

Description

Silicon compound-containing liquid, silicon compound-containing material, and manufacturing method thereof

[0001] The present invention relates to a silicon compound-containing liquid, a silicon compound-containing material, and a method for producing the same.

[0002] Conventionally, highly dispersible aqueous silicic acid solutions contain SiO ２ The dispersibility has been improved by coordinating amines or the like to the fine particles. ２ In the production of fine particles, high-boiling amines have been used as additives. For example, the porous silica particles disclosed in Patent Document 1 are obtained by mixing tetraalkoxysilane with alkylamine and then subjecting the tetraalkoxysilane to hydrolysis and condensation reactions. The alkylamines mixed with the tetraalkoxysilane include high-boiling amines such as octylamine, decylamine, laurylamine, and oleylamine.

[0003] International Publication No. 2012 / 099185

[0004] However, such aqueous silicic acid solution and SiO ２ When forming a coating film using fine particles, SiO ２ The fine particles and the high-boiling amine used as an additive caused problems such as poor adhesion of the coating after drying, making it unsuitable for forming coatings. Also, when silicon-containing raw materials are generally made into basic solutions that do not contain salts, gelation and suspension are often observed over time.

[0005] In view of the above problems, the present invention provides a silicon compound-containing liquid and a silicon compound-containing material that are basic and have high transparency and dispersibility, and methods for producing the same.

[0006] The silicon compound-containing liquid of the present invention, which has been made to solve the above problems, is a silicon compound-containing liquid containing a silicon compound and water, characterized in that the maximum transmittance in the wavelength range of 400 nm to 900 nm measured by an ultraviolet-visible spectrophotometer is 60% T or more. The silicon compound-containing liquid of the present invention is a silicon compound-containing liquid containing a silicon compound and water, and is preferably a silicon compound-containing liquid containing a silicon compound and water, and having a maximum transmittance in the wavelength range of 400 nm to 900 nm measured by an ultraviolet-visible spectrophotometer of 60% T or more, in terms of excellent transparency and dispersibility.

[0007] It is assumed that the silicon compound in the silicon compound-containing liquid of the present invention exists as ions formed by multi-stage condensation of silicon atoms and oxygen atoms in the inclusion. Furthermore, it is assumed that when an organic nitrogen compound is present in the silicon compound-containing liquid of the present invention, it interacts with the silicon compound, causing nitrogen atoms and carbon atoms to be present in close proximity to the silicon atoms.

[0008] Examples of solvents for the silicon compound-containing liquid of the present invention include water and organic solvents. Examples of organic solvents include alcohol solvents, ketone solvents, ether solvents, ester solvents, aromatic hydrocarbon solvents, and aliphatic hydrocarbon solvents, and these organic solvents may be mixed with water. Examples of alcohol solvents include alcohols having 5 or fewer carbon atoms (methanol, ethanol, n-propanol, isopropyl alcohol, butanol, ethylene glycol, propylene glycol, and glycerin), and acetone. Using water as the solvent for the silicon compound-containing liquid of the present invention is preferable because it reduces carbon dioxide derived from organic components that is generated during baking and other processes in the coating film production process, and also reduces the impact and danger to the human body that accompanies use.

[0009] The silicon compound-containing liquid of the present invention is preferably excellent in transparency and dispersibility if the maximum value of transmittance in the wavelength range of 400 nm to 900 nm measured with an ultraviolet-visible spectrophotometer is 60% T or more.

[0010] Furthermore, the silicon compound-containing liquid of the present invention preferably has a maximum transmittance of 65% T or more as measured by an ultraviolet-visible spectrophotometer in the wavelength range of 400 nm to 900 nm, even more preferably 70% T or more, particularly preferably 80% T or more, more particularly preferably 90% T or more, even more particularly preferably 95% T or more, particularly preferably 97% T or more, even more particularly preferably 99% T or more, even more particularly preferably 99.5% or more, and most preferably 100% T. Note that if the measured value exceeds 100% T due to measurement error of the ultraviolet-visible spectrophotometer used to measure the transmittance, it is considered to be 100% T.

[0011] Furthermore, the silicon compound-containing liquid of the present invention preferably has at least one maximum value of transmittance measured by an ultraviolet-visible spectrophotometer at wavelengths of 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, or 900 nm of 60% T or more, more preferably 65% ​​T or more, even more preferably 70% T or more, particularly preferably 80% T or more, more particularly preferably 90% T or more, even more particularly preferably 95% T or more, even more particularly preferably 97% T or more, even more particularly preferably 99% T or more, even more particularly preferably 99.5% or more, and most preferably 100% T. Note that if the measured value exceeds 100% T due to measurement error of the ultraviolet-visible spectrophotometer used to measure the transmittance, it is considered to be 100% T.

[0012] Furthermore, the silicon compound-containing liquid of the present invention preferably has a minimum transmittance of 60% T or more as measured by an ultraviolet-visible spectrophotometer in the wavelength region of 400 nm to 900 nm, more preferably 65% ​​T or more, even more preferably 70% T or more, particularly preferably 80% T or more, more particularly preferably 90% T or more, even more particularly preferably 95% T or more, even more particularly preferably 97% T or more, even more particularly preferably 99% T or more, even more particularly preferably 99.5% or more, and most preferably 100% T. Note that if the measured value exceeds 100% T due to measurement error of the ultraviolet-visible spectrophotometer used to measure the transmittance, it is considered to be 100% T.

[0013] Thus, a liquid in which the maximum transmittance of the silicon compound-containing liquid of the present invention in the wavelength region of 400 nm to 900 nm is 60% T or more is defined as the "silicon compound-containing liquid" of the present invention. Furthermore, in this specification, unless otherwise specified, "transmittance" includes both "initial transmittance" which indicates the transmittance of the silicon compound-containing liquid of the present invention adjusted to a liquid temperature of 25°C immediately after production, and "transmittance over time" which indicates the transmittance of the silicon compound-containing liquid of the present invention after it has been left to stand for two months from the day it was produced in an incubator set at room temperature of 25°C.

[0014] The transmittance of the silicon compound-containing liquid of the present invention as described above by an ultraviolet-visible spectrophotometer can be determined by placing 3 g of the silicon compound-containing liquid of the present invention, adjusted to room temperature (25°C), in a measurement cell (light path length 1 cm), and measuring the ultraviolet-visible absorption spectrum (UV-Vis absorption spectrum) in accordance with JIS K 0115, 2004 "General rules for absorptiometric analysis methods" under the transmittance measurement conditions below.

[0015] =Transmittance measurement conditions= Measuring device: U-2900 spectrophotometer (manufactured by Hitachi High-Tech Corporation) Measurement mode: wavelength scan Data mode: %T (transmittance) Measurement wavelength range: 200-1000 nm Scan speed: 200 nm / min Sampling interval: 1 nm Cell length: 10 mm Measurement cell: disposable square cell for particle size (manufactured by Otsuka Electronics Co., Ltd.)

[0016] In the present invention, the term "containing liquid" refers to a liquid state described below or a liquid state containing a gel. Furthermore, the liquid state is not limited to a state in which a solute is dispersed or mixed in a solvent in a monomolecular state, but also includes an aggregate in which a plurality of molecules are attracted to each other by intermolecular interactions, such as (1) polymer molecules, (2) solvated molecules, (3) molecular clusters, (4) colloidal particles, etc., dispersed in a solvent.

[0017] The silicon compound-containing liquid of the present invention is a silicon compound-containing liquid containing a silicon compound and water, characterized in that the particles in the silicon compound-containing liquid have an average particle size (D50) of 1000 nm or less as measured by a dynamic light scattering method. The silicon compound-containing liquid of the present invention is a silicon compound-containing liquid containing a silicon compound and water, and it is preferable that the particles in the silicon compound-containing liquid have an average particle size (D50) of 1000 nm or less as measured by a dynamic light scattering method, from the viewpoint of excellent transparency and dispersibility.

[0018] In the silicon compound-containing liquid of the present invention, when the particle size distribution is measured using a dynamic light scattering method, the average particle size (D50) of the particles in the silicon compound-containing liquid is 1000 nm or less, which is preferable from the viewpoint of stability due to small changes over time, formation of a good coating film with few uncoated areas during film formation, and ensuring a sufficient coating weight.Furthermore, the smaller the average particle size (D50) of the particles in the silicon compound-containing liquid, the more preferable from the viewpoint of stability due to small changes over time, formation of a good coating film with few uncoated areas during film formation, and ensuring a sufficient coating weight. The average particle size (D50) of the particles in the silicon compound-containing liquid is more preferably 900 nm or less, even more preferably 800 nm or less, particularly preferably 700 nm or less, more preferably 600 nm or less, even more preferably 500 nm or less, particularly preferably 400 nm or less, even more preferably 300 nm or less, even more preferably 200 nm or less, particularly preferably 100 nm or less, and even more preferably 80 nm or less, even more preferably 50 nm or less, particularly preferably 30 nm or less, even more preferably 20 nm or less, even more preferably 10 nm or less, particularly preferably 5 nm or less, and most preferably 3 nm or less. Thus, the average particle size (D50) of the particles in the silicon compound-containing liquid of the present invention is measured using dynamic light scattering, and the liquid in which the average particle size (D50) of the particles is 1000 nm or less is referred to as the "silicon compound-containing liquid" of the present invention.

[0019] Here, dynamic light scattering is a method in which a solution such as a suspension is irradiated with light such as laser light, and the light scattering intensity from a group of particles undergoing Brownian motion is measured, and particle size and distribution are determined from the temporal fluctuation of that intensity. Specifically, the particle size distribution is evaluated using a zeta potential, particle size, and molecular weight measurement system (manufactured by Otsuka Electronics Co., Ltd.: ELSZ-2000ZS) in accordance with JIS Z 8828:2019 "Particle size analysis - dynamic light scattering method." Just before measurement, the solution is filtered through a 2 μm pore size filter and ultrasonically treated for 3 minutes at 28 kHz in an ultrasonic cleaner (manufactured by AS ONE Corporation: VS-100III). The average particle size (D50) refers to the median diameter (D50), which is the particle size that represents the 50% cumulative value of the cumulative distribution curve. Furthermore, in this specification, unless otherwise specified, the "average particle size (D50)" includes both the "initial average particle size D50" which indicates the average particle size (D50) of particles in the silicon compound-containing liquid of the present invention adjusted to a liquid temperature of 25°C immediately after production, and the "average particle size over time D50" which indicates the average particle size (D50) of particles in the silicon compound-containing liquid of the present invention after it has been left to stand for two months from the day the silicon compound-containing liquid of the present invention was produced in an incubator set at room temperature of 25°C.

[0020] The silicon compound-containing liquid of the present invention is also characterized in that the silicon compound-containing liquid further contains an organic nitrogen compound. As described above, the silicon compound-containing liquid of the present invention is preferably one that further contains an organic nitrogen compound in addition to the silicon compound and water, in that it has high solubility and excellent stability over time.

[0021] The organic nitrogen compound according to the present invention includes those ionized in the silicon compound-containing liquid of the present invention. As will be explained in detail later in the method for producing the silicon compound-containing liquid of the present invention, in the production process, a solution containing an organic nitrogen compound is added to a mixed liquid containing a precursor of a silicon compound, and the mixture is stirred to produce the silicon compound-containing liquid of the present invention, and therefore it is believed that the substituted organic nitrogen compound exists as a cation in the silicon compound-containing liquid.

[0022] As the organic nitrogen compound, for example, primary amines, secondary amines, tertiary amines, and quaternary ammonium salts are preferred in that they provide higher solubility and stability over time. These may also be amino alcohols or amino acids. Furthermore, the organic nitrogen compound is more preferably a primary amine, a secondary amine, or a quaternary ammonium salt, and primary amines and quaternary ammonium salts are particularly preferred in that they further enhance solubility. Furthermore, from the viewpoint of ease of volatilization of the organic nitrogen compound when the silicon compound-containing liquid of the present invention is applied to a substrate and a film is formed, primary amines and secondary amines are more preferred, and primary amines are particularly preferred.

[0023] Examples of primary amines include methylamine, ethylamine, propylamine, butylamine, etc. The primary amine may also be an amino alcohol, such as aminoethanol.

[0024] Examples of secondary amines include dimethylamine, diethylamine, dipropylamine, dibutylamine, etc. The secondary amine may also be an amino alcohol, such as diethanolamine.

[0025] Examples of tertiary amines include trimethylamine, triethylamine, and tri-n-propylamine.

[0026] Examples of quaternary ammonium salts include salts of quaternary ammonium cations and anions. Examples of quaternary ammonium salts include alkylimidazolium, pyridinium, pyrrolidium, and tetraalkylammonium. Specific examples of alkylimidazolium salts include 1-methyl-3-methylimidazolium, 1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, 1-methyl-2,3-dimethylimidazolium, 1-ethyl-2,3-dimethylimidazolium, 1-propyl-2,3-dimethylimidazolium, and 1-butyl-2,3-dimethylimidazolium. Specific examples of pyridinium and pyrrolidium include N-butyl-pyridinium, N-ethyl-3-methyl-pyridinium, N-butyl-3-methyl-pyridinium, N-hexyl-4-(dimethylamino)-pyridinium, N-methyl-1-methylpyrrolidinium, and N-butyl-1-methylpyrrolidinium. Specific examples of tetraalkylammonium include tetramethylammonium, tetraethylammonium, tetrabutylammonium, ethyl-dimethyl-propylammonium, and choline. Examples of anions that form salts with the above-mentioned cations include OH, － , Cl － ,Br － , I － , B.F. ４ － , HSO ４ － Examples include:

[0027] The method for measuring the content of organic nitrogen compounds present in the contents includes gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), etc. ２ A method of quantifying the amount of the heat-transfer component using a thermal conductivity meter may also be used in combination.

[0028] The silicon compound-containing liquid of the present invention is characterized in that the Si content in the silicon compound-containing liquid is 0.01 mass% or more and 15.0 mass% or less in terms of Si atoms. In the silicon compound-containing liquid of the present invention, the Si content in the silicon compound-containing liquid is 0.01 mass% or more and 15.0 mass% or less in terms of Si atoms, which is preferable in terms of improving the stability of the silicon compound-containing liquid.

[0029] Here, the Si content in the silicon compound-containing liquid of the present invention is calculated by diluting the liquid appropriately with dilute hydrochloric acid as needed, and measuring the Si weight fraction in terms of Si atoms using high-frequency inductively coupled plasma optical emission spectroscopy (ICP optical emission spectroscopy (AG-5110 manufactured by Agilent Technologies)) in accordance with JIS K0116:2014.

[0030] The silicon compound-containing liquid of the present invention is characterized in that the pH of the silicon compound-containing liquid is 9.5 or higher. This is because the silicon compound-containing liquid of the present invention has a pH of 9.5 or higher, which is more stable. The pH is more preferably 10 or higher, even more preferably 10.5 or higher, particularly preferably 11 or higher, and even more particularly preferably 11.5 or higher. The pH may be 12 or higher, or even 12.5 or higher. In this specification, unless otherwise specified, "pH" refers to both the "initial pH", which is the pH of the silicon compound-containing liquid of the present invention adjusted to a liquid temperature of 25 ° C. immediately after production, and the "chronic pH", which is the pH of the silicon compound-containing liquid of the present invention after being left standing for two months from the day the silicon compound-containing liquid of the present invention was produced in an incubator set at room temperature of 25 ° C.

[0031] Here, the pH of the silicon compound-containing liquid of the present invention is measured by immersing an electrode (HORIBA: Standard ToupH electrode 9615S-10D) of a pH meter (HORIBA: Glass electrode type hydrogen ion concentration indicator D-51) in the silicon compound-containing liquid of the present invention and confirming that the liquid temperature has stabilized at 25°C.

[0032] The silicon compound-containing liquid of the present invention is characterized by further containing a compound containing one or more elements selected from the group consisting of Nb, Ta, Mo, W, Ti, Zr, Hf, Cu, Sn, and Zn. It is assumed that the silicon compound-containing liquid of the present invention is present in the liquid as ions in an ionic bond between the silicon compound and a compound containing one or more elements selected from the group. Examples of compounds containing one or more elements selected from the group include oxides, alkali metal salts of metal acids, alkaline earth metal salts of metal acids, chlorides, metal alkoxides, and polyoxometalates. The silicon compound-containing liquid of the present invention also includes those in which a gel-like precipitate forms in the "containing liquid."

[0033] Regarding the content of the compound containing one or more elements selected from the group, when the total number of moles of each element contained in metal equivalent is X, the molar ratio X / Si of the total number of moles of each element contained in metal equivalent to Si (X) may be 0.05 to 0.1, 0.1 to 0.3, 0.3 to 0.5, 0.5 to 1, 1 to 3, 3 to 5, 5 to 10, or 10 to 20.

[0034] The silicon compound-containing liquid of the present invention may further contain a resin, which is preferable in that the resin is uniformly compatible with the silicon compound and acts to adhere to the substrate, thereby improving film-forming properties and adhesion to the substrate.

[0035] Examples of the resin contained in the silicon compound-containing liquid include polyolefin compounds and polyvinyl compounds.

[0036] Furthermore, the resin contained in the silicon compound-containing liquid of the present invention may be an anionic water-soluble resin and / or a nonionic water-soluble resin. When the resin contained in the silicon compound-containing liquid of the present invention is an anionic water-soluble resin and / or a nonionic water-soluble resin, the anionic water-soluble resin and / or the nonionic water-soluble resin are uniformly compatible with the silicon compound and function to adhere to the substrate, thereby improving film-forming properties and adhesion to the plastic film substrate.

[0037] Here, the cationic water-soluble resin is a resin that has a positive charge in water at pH = 7 and has a functional group such as an amino group, an imino group, a tertiary amine group, a quaternary ammonium group, or a hydrazino group in the polymer. The anionic water-soluble resin is a resin that has a negative charge in water at pH = 7 and has a functional group such as a carboxyl group, a sulfonic acid group, a sulfate ester group, or a phosphate ester group in the polymer. The nonionic water-soluble resin is not the cationic water-soluble resin or anionic water-soluble resin described above, and is a resin that has a functional group such as a hydroxyl group, an ether group, or an amide group in the polymer.

[0038] Furthermore, these resins may contain one or more water-soluble homopolymers selected from the group consisting of acrylic polymers, urethane polymers, styrene polymers, olefin polymers, amide polymers, siloxane polymers, epoxy polymers, vinyl chloride polymers, and vinyl acetate polymers, and / or water-soluble copolymers consisting of two or more of these polymers. In particular, it is preferable for the resins to contain one or more water-soluble homopolymers of acrylic polymers, styrene polymers, and olefin polymers, and / or water-soluble copolymers consisting of two or more of these polymers.

[0039] The silicon compound-containing liquid of the present invention may further contain a high-boiling point solvent. The silicon compound-containing liquid of the present invention is aqueous and can be dried at a low temperature of 100°C or less or dried by heating to form a film. However, the silicon compound-containing liquid of the present invention containing a high-boiling point solvent can be heated to form a film of SiO ２It is possible to generate fine particles or SiO after heating. ２ Since only a film remains, it is possible to combine a high-boiling point solvent with the silicon compound-containing liquid of the present invention, as long as the effects of the present invention are not impaired. Here, the high-boiling point solvent is preferably a solvent having a boiling point of more than 100°C at 1 atmosphere, and may also be a solvent having a boiling point of more than 180°C. Examples of such solvents include polyhydric alcohol solvents and glycol solvents (e.g., glycol solvents, glycol ester solvents, glycol ether solvents).

[0040] Examples of polyhydric alcohol solvents include glycerin (boiling point: 290°C), 1,6-hexanediol (boiling point: 250°C), and 1,7-heptanediol (boiling point: 259°C). Examples of glycol solvents include ethylene glycol (boiling point: 197.3°C), propylene glycol (boiling point: 188.2°C), diethylene glycol (boiling point: 244.3°C), triethylene glycol (boiling point: 287.4°C), oligoethylene glycol (boiling point: 287°C to 460°C), propylene glycol monomethyl ether acetate (PGMEA) (boiling point: 146.4°C), polyethylene glycol (PEG) (boiling point: 460°C or higher), polyethylene glycol (PEG)-polypropylene glycol (PPG) copolymer (boiling point: 460°C or higher), diethylene glycol monohexyl ether acetate (PGMEA) (boiling point: 146.4°C), polyethylene glycol (PEG) (boiling point: 460°C or higher), polyethylene glycol (PEG)-polypropylene glycol (PPG) copolymer (boiling point: 460°C or higher), and diethylene glycol monohexyl ether acetate (PGMEA). Examples of suitable surfactants include silyl ether (boiling point: 260°C), polyoxyalkylene monoalkyl ether (boiling point: 260°C or higher), polyoxyethylene sorbitan monolaurate (boiling point: 321°C or higher), polyvinyl butyral (PVB) (boiling point: 180°C or higher), polyvinyl alcohol (PVA) (boiling point: 180°C or higher), polyetherimide (PEI) (boiling point: 180°C or higher), anionic fluorosurfactants (boiling point: 180°C or higher), amphoteric fluorosurfactants (boiling point: 180°C or higher), nonionic fluorosurfactants (boiling point: 180°C or higher), and amine oxides (boiling point: 180°C or higher). Glycerin is particularly preferred. The boiling points mentioned above are those at 1 atmosphere.

[0041] Since a high-boiling solvent has a high boiling point, if its boiling point at 1 atmospheric pressure is excessively high, the high-boiling solvent may decompose before boiling, making it impossible to measure the boiling point accurately. In such cases, the boiling point at reduced pressure may be measured and converted to the boiling point at 1 atmospheric pressure using a general-purpose boiling point conversion table.

[0042] The silicon compound-containing liquid of the present invention may further contain a low-boiling point solvent. The silicon compound-containing liquid of the present invention is aqueous and can be formed into a film by drying at a low temperature of 100 ° C or less or by heating and drying. The silicon compound-containing liquid of the present invention containing a low-boiling point solvent can be further imparted with quick-drying properties by heating. It is also possible to combine the silicon compound-containing liquid of the present invention with a low-boiling point solvent within a range that does not impair the effects of the present invention. Here, the low-boiling point solvent is preferably a solvent having a boiling point of 100 ° C or less at 1 atmosphere, and more preferably a solvent below 100 ° C. For example, an alcohol-based solvent or the like can be mentioned.

[0043] Specifically, examples of alcohol-based solvents include methanol (boiling point: 64.7°C or higher), ethanol (boiling point: 78.3°C or higher), industrial ethanol, and isopropyl alcohol (boiling point: 82.3°C or higher). Industrial ethanol and isopropyl alcohol are particularly preferred. The above-mentioned boiling points are those at 1 atmosphere.

[0044] Furthermore, the silicon compound-containing liquid of the present invention may contain components other than those derived from silicon or silicic acid and those derived from organic nitrogen compounds (hereinafter referred to as "other components") as unavoidable impurities, to the extent that the effect of the liquid is not impaired.

[0045] The silicon compound-containing liquid of the present invention may contain additives such as dispersants, pH adjusters, colorants, thickeners, wetting agents, and binder resins, depending on the intended use.

[0046] The method for producing the silicon compound-containing liquid of the present invention described above will be described below.

[0047] The method for producing a silicon compound-containing liquid of the present invention is characterized by comprising a mixing step of adding an acidic aqueous solution to a silicon-containing raw material and stirring the mixture at a temperature of 15°C or higher and 50°C or lower to obtain a mixed liquid containing a precursor of a silicon compound, and a stirring step of adding a solution containing an organic nitrogen compound to the mixed liquid and stirring the mixture at a temperature of 15°C or higher and 50°C or lower to produce a silicon compound-containing liquid.

[0048] First, in the mixing step, an acidic aqueous solution is added to a silicon-containing raw material, and the mixture is stirred at 15° C. or higher and 50° C. or lower to obtain a mixed solution containing a precursor of a silicon compound.

[0049] Examples of the silicon-containing raw material include tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), sodium silicate (sodium silicate), etc. The silicon-containing raw material preferably contains at least one of tetraethoxysilane and sodium silicate.

[0050] Examples of the acidic aqueous solution include carboxylic acids, hydroxy acids, hydrochloric acid, sulfuric acid, and phosphoric acid. Examples of the hydroxy acids that can be used include citric acid, lactic acid, tartaric acid, and malic acid. Hydroxy acids also include various isomers (structural isomers, optical isomers, and the like). The acidic aqueous solution preferably contains at least one of carboxylic acids, hydroxy acids, hydrochloric acid, sulfuric acid, and phosphoric acid, and more preferably contains at least one of acetic acid, citric acid, lactic acid, tartaric acid, malic acid, hydrochloric acid, and phosphoric acid.

[0051] When the acidic aqueous solution is acetic acid, the acetic acid content is preferably 0.001% by mass to 3.0% by mass. When the silicon-containing raw material is TEOS, the acetic acid content of 0.001% by mass or more efficiently converts the silanol ester group Si—O—CH in TEOS. ２ -OH ３can be hydrolyzed to form Si—OH structures. On the other hand, an acetic acid content of 3.0% by mass or less is preferable because it reduces the acetic acid content in the final product, the silicon compound-containing liquid of the present invention. From this perspective, the acetic acid content is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and even more preferably 0.01% by mass or more. On the other hand, the acetic acid content is preferably 3.0% by mass or less, more preferably 2.5% by mass or less, even more preferably 2.0% by mass or less, particularly preferably 1.5% by mass or less, even more particularly preferably 1.0% by mass or less, even more particularly preferably 0.5% by mass or less, even more particularly preferably 0.1% by mass or less, even more particularly preferably 0.05% by mass or less, even more particularly preferably 0.04% by mass or less, even more particularly preferably 0.03% by mass or less, and even more particularly preferably 0.02% by mass or less. Unless otherwise specified, the acetic acid content described herein refers to the content when added to the silicon-containing raw material in the mixing step.

[0052] The acetic acid content in the silicon compound-containing liquid of the present invention is preferably 0.02% by mass to 10% by mass. The acetic acid content is more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, particularly preferably 0.15% by mass or more, and even more particularly preferably 0.2% by mass or more. On the other hand, the acetic acid content is more preferably 5% by mass or less, even more preferably 3% by mass or less, particularly preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

[0053] Furthermore, the amount of acetic acid added to the silicon-containing raw material is CH ３ The molar ratio of COOH / Si is preferably 0.01 or more and 0.3 or less, more preferably 0.02 or more and 0.25 or less, and even more preferably 0.03 or more and 0.2 or less. Furthermore, the time for adding acetic acid to the silicon-containing raw material is preferably 5 minutes or less, more preferably 3 minutes or less, and even more preferably 1 minute or less. Furthermore, the acetic acid content in the silicon compound-containing liquid of the present invention is preferably 0.01 or more and 0.3 or less, more preferably 0.02 or more and 0.2 or less. ３The COOH / Si molar ratio is preferably 0.01 or more and 0.3 or less, more preferably 0.02 or more and 0.25 or less, and even more preferably 0.03 or more and 0.2 or less.

[0054] When the acidic aqueous solution added to the silicon-containing raw material is hydrochloric acid, the hydrochloric acid content is preferably 0.001% by mass to 3.0% by mass. When the silicon-containing raw material is sodium silicate, a hydrochloric acid content of 0.001% by mass or more allows efficient production of sodium chloride from sodium silicate. On the other hand, a hydrochloric acid content of 3.0% by mass or less is preferable because chlorine is less likely to remain in the final product, the silicon compound-containing liquid of the present invention. From this perspective, the hydrochloric acid content is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and even more preferably 0.01% by mass or more. On the other hand, the hydrochloric acid content is preferably 3.0% by mass or less, more preferably 2.5% by mass or less, even more preferably 2.0% by mass or less, particularly preferably 1.5% by mass or less, more particularly preferably 1.0% by mass or less, even more particularly preferably 0.5% by mass or less, even particularly preferably 0.1% by mass or less, even more particularly preferably 0.05% by mass or less, even more particularly preferably 0.04% by mass or less, even more particularly preferably 0.03% by mass or less, and even more particularly preferably 0.02% by mass or less. Unless otherwise specified, the hydrochloric acid content described in this specification is the content when added to the silicon-containing raw material in the mixing step, and is a value converted into the weight of HCl in a 0.5N hydrochloric acid aqueous solution.

[0055] The hydrochloric acid content in the silicon compound-containing liquid of the present invention is preferably 0.02% by mass to 10% by mass. The hydrochloric acid content is more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, particularly preferably 0.15% by mass or more, and even more particularly preferably 0.2% by mass or more. On the other hand, the hydrochloric acid content is more preferably 5% by mass or less, even more preferably 3% by mass or less, particularly preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

[0056] Furthermore, the amount of hydrochloric acid added to the silicon-containing raw material is preferably such that the HCl / Si molar ratio is 0.5 or more and 1.5 or less, more preferably 0.55 or more and 1.3 or less, and even more preferably 0.6 or more and 1.1 or less. Furthermore, the time required for adding hydrochloric acid to the silicon-containing raw material is preferably 10 minutes or less, more preferably 5 minutes or less, and even more preferably 3 minutes or less. Furthermore, the content of hydrochloric acid in the silicon compound-containing liquid of the present invention is preferably such that the HCl / Si molar ratio is 0.5 or more and 1.5 or less, more preferably 0.55 or more and 1.3 or less, and even more preferably 0.6 or more and 1.1 or less.

[0057] In the mixing step, after the acidic aqueous solution is added to the silicon-containing raw material, the temperature of the mixture during stirring is preferably 15° C. to 50° C., more preferably 20° C. to 45° C., and even more preferably 25° C. to 40° C. If the temperature of the mixture exceeds 50° C., too much water in the mixture evaporates, and Si—OH groups in the mixture undergo dehydration condensation to form SiO ２ Fine particles may be partially formed, and may not dissolve when a solution containing an organic nitrogen compound is added during the stirring step.

[0058] Furthermore, in the mixing step, the time required for stirring after adding the acidic aqueous solution to the silicon-containing raw material varies depending on the type of silicon-containing raw material, the amount of acidic aqueous solution added, the reduced pressure conditions, and the like.

[0059] Specifically, when the silicon-containing raw material is TEOS and the acidic aqueous solution is acetic acid, the stirring time is preferably 30 minutes or more and 24 hours or less, more preferably 1 hour or more and 15 hours or less, and even more preferably 2 hours or more and 12 hours or less.

[0060] Furthermore, when the silicon-containing raw material is sodium silicate and the acidic aqueous solution is hydrochloric acid, the stirring time is preferably from 10 minutes to 10 hours, more preferably from 30 minutes to 7 hours, and even more preferably from 1 hour to 5 hours.

[0061] In this way, an acidic aqueous solution is added to a silicon-containing raw material and stirred at 15° C. or higher and 50° C. or lower, thereby obtaining a mixed solution containing a precursor of a silicon compound.

[0062] It is presumed that the addition of an acidic aqueous solution to a silicon-containing raw material precursor of a silicon compound results in the formation of a silicic acid with a linear structure, as can be seen from the increase in the absorption maximum intensity attributed to the Si-OH stretching vibration in the infrared spectrum measured using a Fourier transform infrared spectrophotometer (FT-IR) (described below).

[0063] Furthermore, when the silicon-containing raw material is tetraethoxysilane and the acidic aqueous solution is acetic acid, the resulting mixture containing the precursor of the silicon compound is subjected to the next stirring step.

[0064] On the other hand, when the silicon-containing raw material is sodium silicate and the acidic aqueous solution is hydrochloric acid, the resulting mixed solution containing the silicon compound precursor requires the following treatment as a pretreatment before proceeding to the next stirring step. During the stirring, some of the Na in the sodium silicate reacts with some of the Cl in the hydrochloric acid, producing NaCl, which is then contained in the silicon compound precursor. Therefore, it is advisable to remove NaCl from the silicon compound precursor. To remove NaCl, first place the mixed solution containing the silicon compound precursor in a centrifuge tube and centrifuge (4500 rpm, 10 minutes) to recover the precipitated transparent gel. Next, water is added to the recovered transparent gel, which is then placed in a centrifuge tube and centrifuged (4500 rpm, 20 minutes) multiple times, replacing the water, thereby removing NaCl from the silicon compound precursor.

[0065] Next, in the stirring step, the solution containing the organic nitrogen compound is added to the mixed solution containing the precursor of the silicon compound, and the mixture is stirred at 15° C. or higher and 50° C. or lower to produce the silicon compound-containing liquid of the present invention.

[0066] Examples of the organic nitrogen compound include primary amines, secondary amines, tertiary amines, and quaternary ammonium salts. The organic nitrogen compound preferably contains at least one of primary amines, secondary amines, and quaternary ammonium salts, and specific examples thereof include methylamine, ethylamine, dimethylamine, diethylamine, and tetramethylammonium hydroxide. A solution containing an organic acid may be added to the mixture containing the silicon compound precursor, instead of the organic nitrogen compound.

[0067] The amount of the organic nitrogen compound added to the mixed solution containing the precursor of the silicon compound is preferably such that the amine / Si molar ratio is 0.5 or more and 15 or less, more preferably 1 or more and 10 or less, and even more preferably 1.5 or more and 5 or less. Furthermore, from the viewpoint of generating a silicon compound that dissolves in the organic nitrogen compound, the amount of the organic nitrogen compound added to the mixed solution containing the precursor of the silicon compound is preferably such that the amine / Si molar ratio is 1.7 or more, more preferably 1.3 or more, and even more preferably 1.3 or more. On the other hand, from the viewpoint of cost reduction, the amine / Si molar ratio is preferably 1.5 or less, more preferably 1.2 or less, and even more preferably 1 or less.

[0068] The time required for adding the organic nitrogen compound to the mixed solution containing the precursor of the silicon compound is preferably within 60 minutes, more preferably within 30 minutes, and even more preferably within 10 minutes.

[0069] Furthermore, in the stirring step, after adding the solution containing the organic nitrogen compound to the mixed solution containing the precursor of the silicon compound, the liquid temperature during stirring is preferably 15° C. or higher and 50° C. or lower, more preferably 20° C. or higher and 45° C. or lower, and even more preferably 25° C. or higher and 40° C. or lower. Here, if the liquid temperature during stirring exceeds 50° C., the organic nitrogen compound and the like will evaporate, making it difficult for the precursor of the silicon compound to dissolve, and increasing the possibility that the precursor of the silicon compound will remain.

[0070] Furthermore, in the stirring step, after adding the solution containing the organic nitrogen compound to the mixed solution containing the precursor of the silicon compound, the stirring time is preferably 10 minutes or more and 24 hours or less, more preferably 30 minutes or more and 20 hours or less, and even more preferably 1 hour or more and 15 hours or less.

[0071] In this way, the silicon compound-containing liquid of the present invention can be produced by adding a solution containing an organic nitrogen compound to a mixed liquid containing a silicon compound precursor and stirring at 15° C. to 50° C. As described above, it is presumed that the silicon compound precursor contains many Si—OH structures, which makes it easier to dissolve silicon acid in water.

[0072] The silicon compound-containing film of the present invention is characterized by being a silicon compound-containing film formed from the silicon compound-containing liquid of the present invention described above.The silicon compound-containing film of the present invention includes a dried film obtained by applying the silicon compound-containing liquid of the present invention described above to the surface of a substrate, and then drying, for example, vacuum drying, and a fired film obtained by further firing the obtained dried film.The silicon compound-containing film of the present invention also includes silicon compound-containing films with different physical properties, such as crystalline structure, that are produced by vacuum drying or firing the silicon compound-containing liquid of the present invention, and may be an amorphous structure, a single crystal structure, or a polycrystalline structure.

[0073] Next, the method for producing a silicon compound-containing film of the present invention includes the steps of applying the silicon compound-containing liquid of the present invention, drying and / or baking.

[0074] Specifically, among the silicon compound-containing films of the present invention, the method for producing the silicon compound-containing dry film of the present invention includes a coating step of coating the silicon compound-containing liquid of the present invention onto the surface of a substrate, and a film drying step of drying the silicon compound-containing liquid coated on the surface of the substrate to obtain a dry film.

[0075] Specifically, the silicon compound-containing liquid obtained by the method for producing a silicon compound-containing liquid of the present invention described above is dropped onto the surface of a substrate using a syringe, while optionally filtering through a filter with a pore size of, for example, 2 μm, and then applied by spin coating (1,500 rpm, 30 seconds). Next, the resulting solution is dried at 110° C. or higher but lower than 300° C. for 30 minutes to 12 hours to form a silicon compound-containing dry film on the surface of the substrate.

[0076] Furthermore, when the silicon compound-containing liquid obtained by the method for producing a silicon compound-containing liquid of the present invention is a highly viscous liquid or gelled, it may be applied to the surface of a substrate using a brush or the like. Next, the liquid is dried at 110°C or higher but lower than 300°C for 30 minutes to 12 hours to form a silicon compound-containing dry film on the surface of the substrate. Alternatively, the silicon compound-containing dry film of the present invention can be formed on the surface of the substrate by drying for a long period of time, from room temperature to lower than 110°C for 1 hour to 3 days.

[0077] Among the silicon compound-containing films of the present invention, the method for producing a silicon compound-containing fired film of the present invention comprises a coating step of coating a silicon compound-containing liquid on the surface of a substrate, a film drying step of drying the silicon compound-containing liquid coated on the surface of the substrate in the atmosphere or under vacuum to obtain a dried film, and a film firing step of firing the dried film in the atmosphere at a firing temperature of 300°C or higher and 1,200°C or lower for a firing time of 1 hour or higher and 12 hours or lower to obtain a fired film.

[0078] Specifically, as described above, the silicon compound-containing liquid of the present invention is applied to the surface of a substrate, and the substrate is dried to form a silicon compound-containing dried film. The substrate is then placed in a static furnace and baked in the atmosphere at a baking temperature of 300°C or higher and 1,200°C or lower for a baking time of 1 hour or higher and 12 hours or lower, thereby forming a silicon compound-containing baked film of the present invention on the surface of the substrate.

[0079] Furthermore, if the organic nitrogen compound contained in the silicon compound-containing liquid of the present invention contains at least one of a primary amine, a secondary amine, and a quaternary ammonium salt, which have a low boiling point, this is preferable in that when the silicon compound-containing liquid of the present invention is applied to the surface of a substrate and dried, the organic nitrogen compound is easily volatilized, allowing the drying temperature to be kept low and the drying time to be shortened.

[0080] The silicon compound-containing material of the present invention is a silicon compound-containing material containing a silicon compound, and has a 900 cm －１ More than 1000cm －１ The maximum absorption intensity in the following wavenumber band is designated as P1, and 1000 cm －１ The maximum absorption intensity in the wavenumber band of more than 1100 cm or less is designated as P2, and the intensity ratio of P1 to P2: P1 / P2 is 0.9 to 1.6. －１ More than 4000cm －１ The silicon compound-containing material of the present invention is characterized by having an absorption maximum intensity P3 in the following wavenumber band: 900 cm －１ More than 1000cm －１ The maximum absorption intensity in the following wavenumber band is designated as P1, and 1000 cm －１ The maximum absorption intensity in the wavenumber band of more than 1100 cm or less is designated as P2, and the intensity ratio of P1 to P2: P1 / P2 is 0.9 to 1.5. －１ More than 4000cm －１ Those having a maximum absorption intensity P3 in the following wave number band are preferred from the viewpoint of excellent transparency and dispersibility.

[0081] Although the specific structure of the silicon compound in the silicon compound-containing material of the present invention is unknown, it is predicted to be a compound with a low degree of condensation and a large number of hydrolyzed silanol (Si-OH) groups. Therefore, it is assumed that the silicon compound is highly hydrophilic and exists in the material as a compound that is highly soluble in water.

[0082] 900 cm determined by Fourier transform infrared spectrophotometer (FT-IR) －１More than 1000cm －１ The following wavenumber bands are attributed to Si—OH stretching vibrations, and the maximum absorption intensity in each wavenumber band is designated as P1. －１ More than 1100cm －１ The following wavenumber bands are attributed to Si—O—Si stretching vibrations, and the maximum absorption intensity in these wavenumber bands is designated as P2 (see FIG. 1).

[0083] The intensity ratio of P1 to P2: P1 / P2 is preferably 0.9 to 1.5, more preferably 1.1 to 1.4, and even more preferably 1.2 to 1.4.

[0084] Furthermore, the silicon compound-containing material of the present invention has a 2800 cm －１ More than 4000cm －１ It has an absorption maximum intensity P3 in the following wavenumber band (see FIG. 1): Furthermore, it is more preferable that the FT-IR transmittance of P3 is less than 90%.

[0085] The maximum absorption intensities P1, P2, and P3 in each wavenumber band of the silicon compound-containing material of the present invention measured by a Fourier transform infrared spectrophotometer (FT-IR) are determined by measuring the ATR spectrum by the ATR method (attenuated total reflection measurement method) using the silicon compound-containing material of the present invention as a sample under the following FT-IR measurement conditions and method: For example, a transparent crystal obtained by adding an acidic aqueous solution (e.g., acetic acid) to a silicon compound (e.g., tetraethoxysilane), adding industrial ethanol mixed with ethanol, or pure water, and stirring and mixing for 10 hours is used as the sample.

[0086] = FT-IR measurement conditions = Measurement equipment: IR measurement equipment "IRAffinity-1", sample chamber integrated single reflection type total reflection measurement equipment "MIRacle 10" (both manufactured by Shimadzu Corporation) Data mode: %T (transmittance) Measurement range: 400-4000 cm －１ Number of accumulations: 20 Apodization function: Happ-Genzel Detector: Standard Resolution: 4 cm －１Mirror speed: 2.8 mm / sec Software: IR solution version 1.6

[0087] The FT-IR measurement method involves first measuring the background spectrum with the IRAffinity-1 without the MIRacle 10 attached, and then attaching the MIRacle 10 to the IRAffinity-1. The sample is then placed on a diamond prism. A sample clamp is then used to bring the sample into close contact with the prism, and measurements are performed in accordance with the 16th Revised Japanese Pharmacopoeia. After lightly pressing the sample against the prism, the knob on the sample clamp is slowly turned to apply gentle force. It is also recommended to use a rotating tip on the sample clamp to perform the measurements.

[0088] The method for producing a silicon compound-containing material of the present invention described above is characterized by including a drying step in which an acidic aqueous solution is added to a silicon-containing raw material, the mixture is stirred at 15°C or higher and 50°C or lower, and the resulting mixture containing a precursor of the silicon compound is dried to produce a silicon compound-containing material.

[0089] In the method for producing a silicon compound-containing material of the present invention, the process up to obtaining a mixed liquid containing a silicon compound precursor is the same as the mixing process in the method for producing a silicon compound-containing liquid of the present invention described above, so a description thereof will be omitted.

[0090] Next, the resulting mixture containing the precursor of the silicon compound is dried while being stirred at 15° C. or higher and 50° C. or lower, thereby producing a silicon compound-containing material.

[0091] Specifically, the mixed liquid is placed in a static furnace and dried, for example, by vacuum drying, while stirring at a temperature of 15°C to 50°C, whereby the water in the mixed liquid evaporates and the silicon compound-containing material of the present invention is obtained.

[0092] In the drying step, the temperature of the mixed liquid is preferably 15°C or higher and 50°C or lower, more preferably 20°C or higher and 40°C or lower, and even more preferably 25°C or higher and 40°C or lower.

[0093] The time required for the drying step is preferably from 1 hour to 100 hours, more preferably from 1 hour to 48 hours, and even more preferably from 3 hours to 24 hours.

[0094] The silicon compound-containing material obtained may be pulverized and used as the silicon compound-containing material of the present invention. Furthermore, regardless of whether it is pulverized or not, the silicon compound-containing material containing the silicon compound described above may be classified using a sieve or the like, and the undersized particles (fine particles) obtained may be used as the silicon compound-containing material of the present invention. The oversized particles (coarse particles) may be re-pulverized and classified for use. It is also possible to combine pulverization and classification using a vibrating sieve containing nylon or fluororesin-coated iron balls or the like as pulverization media. By combining classification and pulverization in this way, even if silicon compound-containing material containing excessively large silicon compounds is present, it is possible to remove it. Specifically, when classifying using a sieve, it is preferable to use one with a mesh size of 150 μm to 1,000 μm. When the particle size is 150 μm to 1,000 μm, the proportion of oversized particles will not be too high, so that repeated pulverization will not be required, and silicon compound-containing materials that contain silicon compounds that require pulverization will not be classified as undersized particles.

[0095] Furthermore, the silicon compound-containing film of the present invention can be formed from the silicon compound-containing material of the present invention.

[0096] Specifically, a solution containing an organic nitrogen compound is added to the silicon compound-containing material obtained by the method for producing a silicon compound-containing material of the present invention described above, and the mixture is stirred at a temperature of 15°C or higher and 50°C or lower, similar to the stirring step in the method for producing a silicon compound-containing liquid of the present invention, thereby obtaining the silicon compound-containing liquid of the present invention.

[0097] The silicon compound-containing film of the present invention can also be formed by applying the obtained silicon compound-containing liquid of the present invention to the surface of a substrate, drying and / or firing the liquid, in the same manner as in the method for producing a silicon compound-containing film of the present invention described above.

[0098] In this specification, when "X to Y" (X and Y are any numbers) is expressed, unless otherwise specified, it means "X or more and Y or less", and also means "preferably larger than X" or "preferably smaller than Y". Furthermore, when "X or more" (X is any number) or "Y or less" (Y is any number), it also means "preferably larger than X" or "preferably smaller than Y".

[0099] The silicon compound-containing liquid of the present invention is basic and has excellent transparency and dispersibility.

[0100] 1 is a diagram showing ATR spectra measured by total reflection measurement using a Fourier transform infrared spectrophotometer (FT-IR) of silicon compound-containing materials according to Example 1 of the present invention and Comparative Examples 1 and 2. 2 is a table showing physical property values ​​of silicon compound-containing liquids according to Examples 1 to 5 of the present invention and Comparative Examples 1 to 5. 3 is a table showing measurement results of silicon compound-containing liquids according to Examples 1 to 5 of the present invention and Comparative Examples 1 to 5.

[0101] The silicon compound-containing liquid and silicon compound-containing material according to the embodiments of the present invention will be further described below with reference to the following examples, although the present invention is not limited to these examples.

[0102] Example 1 To a 100 mL beaker, 11.0 g of tetraethoxysilane (TEOS, manufactured by Tokyo Ohka Kogyo Co., Ltd.), a silicon-containing raw material, was added 0.1 g of acetic acid (manufactured by Hayashi Pure Chemical Industries, Ltd.), an acidic aqueous solution, 15 g of industrial ethanol (Solmix AP-7 (a mixed alcohol solvent containing 85.5 mass % of ethanol, 9.6 mass % of 1-propanol, 4.9 mass % of 2-propanol, and 0.2 mass % or less of water), manufactured by Toyo Petrochemical Co., Ltd.), and 8 g of pure water. The mixture was mixed for 20 hours at room temperature (25°C) while stirring with a stirrer tip, thereby obtaining a dried silicon compound precursor (corresponding to the silicon compound-containing material of the present invention) as a transparent precipitate.

[0103] The ATR spectrum of the dried silicon compound precursor obtained here was measured under the above-mentioned FT-IR measurement conditions. As shown in FIG. 1, －１ More than 1000cm－１ The following wavenumber bands are attributed to Si—OH stretching vibrations, and the maximum absorption intensity in each wavenumber band was designated as P1. －１ More than 1100cm －１ The following wavenumber bands are attributed to Si—O—Si stretching vibrations, and the maximum absorption intensity in these wavenumber bands was designated as P2. The intensity ratio of P1 to P2, P1 / P2, was 1.38.

[0104] As shown in FIG. －１ More than 4000cm －１ The maximum absorption intensity in the following wavenumber band was designated as P3, and the FT-IR transmittance of P3 was 85% (see Table 1).

[0105] Next, 6.5 g of 40% by mass methylamine (manufactured by Mitsubishi Gas Chemical Company, Inc.) and 5 g of pure water were added to the obtained dried silicon compound precursor, and the mixture was mixed at room temperature (25°C) for 10 hours while stirring with a stirrer tip, thereby obtaining a silicon compound-containing liquid according to Example 1.

[0106] Example 2 In a 2 L beaker, 800 g of 0.5 N hydrochloric acid (acidic aqueous solution) was prepared by mixing 35 mass % hydrochloric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and pure water, and a solution prepared by mixing 100 g of sodium silicate (sodium silicate No. 1-53, manufactured by Fuji Chemical Industry Co., Ltd.), which is a silicon-containing raw material, and 30 g of pure water was slowly added to the solution. The mixture was stirred with a stirrer tip at room temperature (25°C) for 3 hours, thereby obtaining a mixed solution containing a precursor of a silicon compound.

[0107] The obtained mixture containing the silicon compound precursor was placed in a centrifuge tube and centrifuged (4500 rpm, 10 minutes), and the precipitated silicon compound precursor (transparent gel) was recovered. In addition, in order to remove the NaCl contained in the recovered silicon compound precursor, the silicon compound precursor and 200 g of water were placed in a centrifuge tube and centrifuged (4500 rpm, 20 minutes). This operation was repeated 6 times while replacing the water, thereby removing the NaCl contained in the silicon compound precursor.

[0108] Next, 98 g of 40 mass% methylamine and 167 g of pure water were added to the silicon compound precursor from which NaCl had been removed, and the mixture was stirred with a stirrer tip at room temperature (25°C) for 1 hour to obtain a silicon compound-containing liquid according to Example 2.

[0109] Example 3 In the same manner as in Example 1, 3.5 g of 1,1,3,3-tetramethylguanidine (hereinafter referred to as "guanidine", manufactured by Tokyo Ohka Kogyo Co., Ltd.) and 5 g of pure water were added to the obtained silicon compound precursor, and the mixture was stirred with a stirrer tip at room temperature (25°C) for 10 hours to obtain a silicon compound-containing liquid according to Example 3.

[0110] (Example 4) In the same manner as in Example 1, 3.5 g of 40 mass% methylamine (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), 3.5 g of 50 mass% dimethylamine (manufactured by TOKYO OHKA KOGYO CO., LTD.), 3.5 g of 30 mass% trimethylamine (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), 3.5 g of 25 mass% tetramethylamine hydroxide (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), 3.5 g of guanidine (manufactured by TOKYO OHKA KOGYO CO., LTD.), and 5 g of pure water were added to the obtained silicon compound precursor, and the mixture was stirred with a stirrer tip at room temperature (25 ° C.) for 10 hours to obtain a silicon compound-containing liquid according to Example 4.

[0111] (Example 5) In the same manner as in Example 3, 3.5 g of a tantalic acid compound-containing liquid, 3.5 g of a niobic acid compound-containing liquid, 3.5 g of a tungstic acid compound-containing liquid, and 3.5 g of a molybdic acid compound-containing liquid were added to the obtained silicon compound-containing liquid, and the mixture was mixed at room temperature (25°C) for 10 minutes while stirring with a stirrer tip, thereby obtaining a silicon compound-containing liquid according to Example 5.

[0112] The tantalic acid compound-containing liquid used in Example 5 was obtained as follows.

[0113] 137.9g ​​of tantalum hydroxide (Ta) manufactured by Mitsui Mining & Smelting Co., Ltd. ２ O ５A tantalum fluoride aqueous solution (Ta fluoride concentration 66 mass%) was dissolved in 120 g of a 55 mass% hydrofluoric acid aqueous solution, and 849 mL of ion-exchanged water was added to the solution. ２ O ５ A concentration of 8.2% by weight was obtained.

[0114] 1,000 g of this tantalum fluoride aqueous solution was mixed with 27.5 g of hydrogen peroxide (H ２ O ２ Concentration 35% by mass) was added (H ２ O ２ The mixture was stirred for 5 minutes (molar ratio of tantalum to tantalum = 0.76), to obtain an aqueous solution of a tantalum compound.

[0115] 1,000 g of this tantalum compound aqueous solution was added to ammonia water (NH ３ (NH ３ / Ta molar ratio = 245, NH ３ A reaction solution (pH 11) was obtained (mole ratio of HCl / HF=30.7). This reaction solution was a slurry of a tantalic acid compound hydrate, in other words, a slurry of a tantalum-containing precipitate.

[0116] The reaction solution was then decanted using a centrifuge and washed until the amount of liberated fluoride ions was 100 mg / L or less, yielding a tantalum-containing precipitate from which the fluoride ions had been removed, using aqueous ammonia as the washing liquid.

[0117] The tantalum-containing precipitate from which the fluoride ions had been removed was diluted with pure water to obtain a tantalum-containing precipitate slurry. A portion of this tantalum-containing precipitate slurry was dried at 110°C for 24 hours and then fired at 1,000°C for 4 hours to obtain Ta. ２ O ５ and from the weight thereof, the Ta contained in the tantalum-containing precipitation slurry is calculated. ２ O ５ The concentration was calculated.

[0118] Then, the tantalum-containing precipitate slurry diluted with pure water, 5 mass % of dimethylamine as an organic nitrogen compound, and pure water were mixed together to form a final mixture with a tantalum concentration of Ta ２ O ５ 5 mass% in terms of Ta ２ O５ The tantalic acid compound-containing solution used in Example 5 was obtained by mixing the tantalic acid compound-containing solution and the organic nitrogen compound so that the weight ratio of the tantalic acid compound to the organic nitrogen compound was 1.0. The pH of the tantalic acid compound-containing solution used in Example 5 was 12.0.

[0119] The niobic acid compound-containing liquid used in Example 5 was obtained as follows.

[0120] 100 g of niobium pentoxide was dissolved in 200 g of a 55 mass % aqueous solution of hydrofluoric acid, and 830 mL of ion-exchanged water was added to prepare a niobium fluoride aqueous solution (Nb ２ O ５ = 8.84% by mass).

[0121] 200 mL of this niobium fluoride aqueous solution was added to ammonia water (NH ３ (NH ３ / Nb ２ O ５ Molar ratio = 177.9, NH ３ / HF molar ratio=12.2), a reaction liquid (pH 11) was obtained. This reaction liquid was a slurry of a niobic acid compound hydrate, in other words, a slurry of a niobium-containing precipitate.

[0122] The reaction solution was then decanted using a centrifuge and washed until the amount of liberated fluoride ions was 100 mg / L or less, to obtain a niobium-containing precipitate from which the fluoride ions had been removed. At this time, aqueous ammonia was used as the washing liquid.

[0123] Furthermore, the niobium-containing precipitate from which the fluoride ions had been removed was diluted with pure water to obtain a slurry. A portion of this niobium-containing precipitate slurry was dried at 110°C for 24 hours and then calcined at 1000°C for 4 hours to obtain Nb ２ O ５ and determining the Nb content of the niobium-containing precipitation slurry from the weight of the resulting slurry. ２ O ５ The concentration was calculated.

[0124] Then, the niobium-containing precipitate slurry diluted with pure water, 50 mass % of dimethylamine as an organic nitrogen compound, and pure water were mixed together to form a mixture such that the niobium concentration of the final mixture was Nb ２ O ５5 mass% in terms of Nb ２ O ５ The niobic acid compound-containing liquid used in Example 5 was obtained by mixing the niobic acid compound-containing liquid and the organic nitrogen compound in a weight ratio of 2.0. The pH of the niobic acid compound-containing liquid used in Example 5 was 11.0.

[0125] The tungstic acid compound-containing liquid used in Example 5 was obtained as follows.

[0126] 100 g of tungsten trioxide was dissolved in 200 g of a 55 mass % aqueous sulfuric acid solution, and ion-exchanged water was added to convert tungsten to WO ３ An aqueous solution of tungsten sulfate containing 100 g / L of tungsten sulfate was obtained. 200 mL of this aqueous solution of tungsten sulfate was added to ammonia water (NH ３ (NH ３ / WO ３ Molar ratio = 170.47, NH ３ / SO ４ ２－ The reaction mixture was a slurry of a tungstic acid compound hydrate, in other words, a slurry of a tungsten-containing precipitate.

[0127] The reaction solution was then decanted using a centrifuge and washed until the conductivity reached 500 μS / cm or less, yielding a tungsten-containing precipitate from which the sulfur content had been removed. In this case, aqueous ammonia was used as the washing liquid.

[0128] Furthermore, the sulfur-removed tungsten-containing precipitate was diluted with pure water to obtain a sulfur-removed tungsten-containing precipitate slurry. A portion of the sulfur-removed tungsten-containing precipitate slurry was dried at 110°C for 24 hours and then calcined at 1,000°C for 4 hours to obtain WO ３ and WO contained in the tungsten-containing precipitation slurry from which sulfur has been removed from the weight of the resulting slurry. ３ The concentration was calculated.

[0129] The tungsten-containing precipitate slurry, from which the sulfur content has been removed and diluted with pure water, is then mixed to form a mixture having a tungsten concentration of WO ３2% by mass of methylamine was mixed with pure water so that the total concentration was 10% by mass, and the mixture was stirred and held at room temperature (25°C) for 1 hour to obtain the tungstic acid compound-containing liquid used in Example 5. The pH of the tungstic acid compound-containing liquid used in Example 5 was 8.2.

[0130] The molybdic acid compound-containing liquid used in Example 5 was obtained as follows.

[0131] 100 g of molybdenum trioxide was dissolved in 200 g of a 55 mass % aqueous sulfuric acid solution, and ion-exchanged water was added to convert the molybdenum to MoO ３ An aqueous solution of molybdenum sulfate containing 100 g / L of molybdenum sulfate was obtained. 200 mL of this aqueous solution of molybdenum sulfate was added to ammonia water (NH ３ (NH ３ / MoO ３ Molar ratio = 105.66, NH ３ / SO ４ ２－ The reaction mixture was a molybdic acid compound hydrate slurry, in other words, a molybdenum-containing precipitate slurry.

[0132] The reaction solution was then decanted using a centrifuge and washed until the conductivity reached 500 μS / cm or less, yielding a molybdenum-containing precipitate from which sulfur had been removed. In this case, aqueous ammonia was used as the washing liquid.

[0133] Furthermore, the molybdenum-containing precipitate from which the sulfur content had been removed was diluted with pure water to obtain a molybdenum-containing precipitate slurry from which the sulfur content had been removed. A portion of the molybdenum-containing precipitate slurry from which the sulfur content had been removed was dried at 110°C for 24 hours and then calcined at 1,000°C for 4 hours to obtain MoO ３ and the weight of the molybdenum-containing precipitation slurry from which the sulfur content has been removed is calculated based on the weight of the molybdenum-containing precipitation slurry. ３ The concentration was calculated.

[0134] The molybdenum-containing precipitate slurry, from which the sulfur content has been removed and diluted with pure water, is then mixed with a final mixture whose molybdenum concentration is MoO ３2% by mass of methylamine was mixed with pure water so that the total concentration was 10% by mass, and the mixture was stirred and held at room temperature (25°C) for 1 hour to obtain the molybdic acid compound-containing liquid used in Example 5. The pH of the molybdic acid compound-containing liquid used in Example 5 was 9.7.

[0135] Comparative Example 1 In Comparative Example 1, the same production method as in Example 1 was carried out, except that 1 g of water was added to 11.0 g of tetraethoxysilane (TEOS, manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is a silicon-containing raw material, to obtain a silicon compound-containing liquid according to Comparative Example 1. Note that precipitates were confirmed in the silicon compound-containing liquid according to Comparative Example 1.

[0136] Comparative Example 2 In Comparative Example 2, a silicon compound-containing liquid according to Comparative Example 2 was obtained by carrying out the same production method as in Example 1, except that 1 g of 25 mass % ammonia water was added to 11.0 g of tetraethoxysilane (TEOS, manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is a silicon-containing raw material, instead of an acidic aqueous solution, and the resulting mixed liquid containing the precursor of the silicon compound was stirred for 1 hour. Note that precipitates were confirmed in the silicon compound-containing liquid according to Comparative Example 2.

[0137] Comparative Example 3 In Comparative Example 3, the same production method as in Example 1 was carried out, except that the obtained mixed liquid containing the precursor of the silicon compound was heated to 80° C. and stirred for 3 hours, to obtain a silicon compound-containing liquid according to Comparative Example 3. Note that precipitates were confirmed in the silicon compound-containing liquid according to Comparative Example 3.

[0138] Comparative Example 4 In Comparative Example 4, the same production method as in Example 1 was carried out except that 20 g of 30 mass % trimethylamine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 20 g of pure water were added to the obtained mixed liquid containing the precursor of the silicon compound, thereby obtaining a silicon compound-containing liquid according to Comparative Example 4. Note that precipitates were confirmed in the silicon compound-containing liquid according to Comparative Example 4.

[0139] Comparative Example 5 In Comparative Example 5, the same production method as in Example 1 was carried out except that 20 g of 25 mass % ammonia (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 20 g of pure water were added to the obtained mixed liquid containing the precursor of the silicon compound, thereby obtaining a silicon compound-containing liquid according to Comparative Example 5. Note that precipitates were confirmed in the silicon compound-containing liquid according to Comparative Example 5.

[0140] The following physical properties were measured for the silicon compound-containing liquids according to Examples 1 to 5 and Comparative Examples 1 to 5. The measured physical properties and the methods for measuring the physical properties are shown below, and the measurement results are shown in Figures 1 to 3 and Table 1.

[0141] <Elemental Analysis> If necessary, the sample was appropriately diluted with dilute hydrochloric acid, and the Si weight fraction in terms of Si atoms was measured by ICP optical emission spectrometry (AG-5110 manufactured by Agilent Technologies, Inc.) Note that for Example 5, the Ta weight fraction in terms of Ta atoms, the Nb weight fraction in terms of Nb atoms, the W weight fraction in terms of W atoms, and the Mo weight fraction in terms of Mo atoms were also measured in the same manner.

[0142] <Transmittance Measurement> 4 ml of the silicon compound-containing liquid according to Examples 1 to 5, adjusted to room temperature (25°C), was placed in a measurement cell (light path length 1 cm), and measurements were performed according to the transmittance measurement conditions described above. The "initial transmittance" in Figure 3 refers to the transmittance of the silicon compound-containing liquid adjusted to a liquid temperature of 25°C immediately after production. The "transmittance over time" in Figure 3 refers to the transmittance of the silicon compound-containing liquid after being left to stand for two months in an incubator set at room temperature of 25°C. The transmittance of the silicon compound-containing liquid according to Comparative Examples 1 to 5 was not measured because precipitates were observed in the liquid.

[0143] <Dynamic Light Scattering Method> Evaluation of particle size distribution was performed using a zeta potential, particle size, and molecular weight measurement system (manufactured by Otsuka Electronics Co., Ltd.: ELSZ-2000) by dynamic light scattering in accordance with JIS Z 8828:2019. Furthermore, immediately before measurement, in order to remove dust and the like from the silicon compound-containing liquids of Examples 1 to 5, which were the measurement targets, the liquids were filtered through a filter with a 1 μm pore size. Then, ultrasonic treatment was performed for 3 minutes at 28 kHz using an ultrasonic cleaner (manufactured by AS ONE Corporation: VS-100III), thereby performing a dispersion treatment using ultrasound. Furthermore, D50 indicates the particle diameter at which 50% of the particles are obtained by volume fraction. The "initial average particle diameter D50 (nm)" in FIG. 3 refers to the average particle diameter (D50) of particles in the silicon compound-containing liquid immediately after generation. 3 refers to the average particle size (D50) of particles in the silicon compound-containing liquid after being left to stand for two months in an incubator set at room temperature of 25° C. Note that for the silicon compound-containing liquids according to Comparative Examples 1 to 5, the average particle size (D50) was not measured because precipitates were confirmed in the liquids.

[0144] <FT-IR Measurement> Using the dried silicon compound precursors of Example 1 and Comparative Examples 1 and 2 as samples, an ATR spectrum was measured by the ATR method using a Fourier transform infrared spectrophotometer under the above-mentioned FT-IR measurement conditions and FT-IR measurement method, and the 900 cm peak attributable to the Si—OH stretching vibration was detected. －１ More than 1000cm －１ The maximum absorption intensity P1 (%) in the following wavenumber bands is 1000 cm , which is attributed to the Si—O—Si stretching vibration. －１ More than 1100cm －１ The absorption maximum intensity P2 (%) in the following wavenumber bands, and 2800 cm －１ More than 4000cm －１ The maximum absorption intensity P3 (%) in the following wavenumber band was measured. The intensity ratio of P1 to P2, P1 / P2, was then calculated. FIG. 1 shows the ATR spectra of the precursors of the silicon compounds according to Example 1 and Comparative Examples 1 and 2. Table 1 also lists the measured values ​​of P1, P2, and P3, and the calculated value of P1 / P2.

[0145] <pH Measurement> The pH of the silicon compound-containing liquids according to Examples 1 to 5 was measured using an electrode (HORIBA Standard ToupH electrode 9615S-10D) of a pH meter (HORIBA Glass Electrode Hydrogen Ion Concentration Indicator D-51) after confirming that the liquid temperature had stabilized at 25°C. The "initial pH" in FIG. 3 refers to the pH of the silicon compound-containing liquid adjusted to a liquid temperature of 25°C immediately after production. The "pH over time" in FIG. 3 refers to the pH of the silicon compound-containing liquid after standing for two months in an incubator set at room temperature of 25°C. Note that the pH of the silicon compound-containing liquids according to Comparative Examples 1 to 5 was not measured because precipitates were observed in the liquid.

[0146] <Film-Forming Property Test> The appearance of the coating film formed on the surface of the glass substrate was evaluated by observation with an optical microscope. First, the silicon compound-containing liquid according to Examples 1 to 5 and Comparative Examples 1 to 5 was dropped onto a 50 mm x 50 mm glass substrate that had been degreased and washed with acetone using a syringe while being filtered through a filter with a pore size of 1 μm, and then dried. The solution was applied by spin coating (700 rpm, 10 seconds, followed by 1500 rpm, 15 seconds). The applied area was then dried at 100°C for 30 minutes to form a coating film on the glass substrate. The glass substrate was observed with an optical microscope (magnification: 40x) in a central 15 mm x 15 mm area of ​​the formed coating film. Those with no particles present and on which a film was formed were evaluated as having excellent film-forming properties and rated as "○ (GOOD)," while those with particles observed were evaluated as having poor film-forming properties and rated as "× (BAD)."

[0147] As shown in Figures 2 and 3, the silicon compound-containing liquids according to Examples 1 to 5 were silicon compound-containing liquids containing a silicon compound and water, and when the maximum transmittance measured by an ultraviolet-visible spectrophotometer in the wavelength range of 400 nm to 900 nm was 60% T or more, they had excellent transparency and dispersibility.

[0148] The silicon compound-containing liquids according to Examples 1 to 5 were silicon compound-containing liquids containing a silicon compound and water, and when the average particle size (D50) of the particles in the silicon compound-containing liquid measured by dynamic light scattering was 1000 nm or less, the liquids had excellent transparency and dispersibility.

[0149] The silicon compound-containing liquids according to Examples 1 to 5 contained an organic nitrogen compound, and therefore had high solubility and excellent stability over time.

[0150] The silicon compound-containing liquids of Examples 1 to 5 had improved stability because the Si content in terms of Si atoms in the silicon compound-containing liquid was 0.01 mass % or more and 15.0 mass % or less.

[0151] When the silicon compound-containing liquids according to Examples 1 to 5 had a pH of 9.5 or higher, the stability of the liquids was improved.

[0152] The silicon compound-containing liquid of Example 5 further contained a compound containing one or more elements selected from the group consisting of Nb, Ta, Mo, W, Ti, Zr, Hf, Cu, Sn, and Zn, and had excellent transparency and dispersibility.

[0153] As shown in FIG. 1 and Table 1, the silicon compound-containing material according to Example 1 is a silicon compound-containing material containing a silicon compound, and has a 900 cm －１ More than 1000cm －１ The maximum absorption intensity in the following wavenumber band is designated as P1, and 1000 cm －１ Super 1100cm － The maximum absorption intensity in the wavenumber band of 2800 cm or less is defined as P2, and the intensity ratio of P1 to P2: P1 / P2 is 0.9 to 1.5. －１ More than 4000cm －１ When the absorbent had a maximum absorption intensity P3 in the following wavenumber band, the transparency and dispersibility were excellent.

[0154]

[0155] The inventions disclosed in this specification include, in addition to the configurations of each invention and embodiment, those specified by changing these partial configurations to other configurations disclosed in this specification, to the extent applicable, or those specified by adding other configurations disclosed in this specification to these configurations, or those specified as higher-level concepts specified by deleting these partial configurations to the extent that partial effects can be obtained.

[0156] The silicon compound-containing liquid according to the present invention is basic and highly dispersible, making it suitable as a coating material or composite material with high film adhesion and film uniformity. Furthermore, the silicon compound-containing liquid according to the present invention has excellent storage stability and can reduce the rate of defective products caused by precipitation due to changes over time, thereby reducing waste and energy costs for waste disposal. Furthermore, the silicon compound-containing liquid according to the present invention also forms a good coating film, so that the coated coating material can also reduce waste and reduce the rate of defective products. These points lead to the sustainable management and efficient benefits of natural resources, as well as the achievement of decarbonization (carbon neutrality).

Claims

1. A silicon compound-containing liquid containing a silicon compound and water, characterized in that the maximum transmittance in the wavelength range of 400 nm to 900 nm measured by an ultraviolet-visible spectrophotometer is 60% T or more.

2. The silicon compound-containing liquid according to claim 1, characterized in that the maximum transmittance of the silicon compound-containing liquid measured by an ultraviolet-visible spectrophotometer in the wavelength range of 400 nm to 900 nm is 90% T or more.

3. The silicon compound-containing liquid according to claim 1, characterized in that at least one of the maximum transmittance values measured by an ultraviolet-visible spectrophotometer at wavelengths of 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, or 900 nm of the silicon compound-containing liquid is 60% T or higher.

4. The silicon compound-containing liquid according to claim 1, characterized in that the minimum transmittance of the silicon compound-containing liquid measured by an ultraviolet-visible spectrophotometer in the wavelength range of 400 nm to 900 nm is 60% T or more.

5. A silicon compound-containing liquid containing a silicon compound and water, characterized in that the particles in the silicon compound-containing liquid have an average particle size (D50) of 1000 nm or less as measured by a dynamic light scattering method.

6. The silicon compound-containing liquid according to claim 5, characterized in that the particles in the silicon compound-containing liquid have an average particle size (D50) of 100 nm or less as determined by dynamic light scattering.

7. The silicon compound-containing liquid according to any one of claims 1 to 6, characterized in that the silicon compound-containing liquid further contains an organic nitrogen compound.

8. A silicon compound-containing liquid described in any one of claims 1 to 6, characterized in that the Si content in terms of Si atoms in the silicon compound-containing liquid is 0.01 mass% or more and 15.0 mass% or less.

9. The silicon compound-containing liquid according to any one of claims 1 to 6, characterized in that the silicon compound-containing liquid has a pH of 9.5 or higher.

10. A silicon compound-containing liquid described in any one of claims 1 to 6, characterized in that the silicon compound-containing liquid further contains a compound containing one or more elements selected from the group consisting of Nb, Ta, Mo, W, Ti, Zr, Hf, Cu, Sn, and Zn.

11. A silicon compound-containing film, characterized in that it is a silicon compound-containing film formed from the silicon compound-containing liquid according to any one of claims 1 to 6.

12. A method for producing a silicon compound-containing liquid, comprising: a mixing step of adding an acidic aqueous solution to a silicon-containing raw material and stirring at 15°C or higher and 50°C or lower to obtain a mixed liquid containing a silicon compound precursor; and a stirring step of adding a solution containing an organic nitrogen compound to the mixed liquid and stirring at 15°C or higher and 50°C or lower to produce a silicon compound-containing liquid.

13. The method for producing a silicon compound-containing liquid according to claim 12, characterized in that the silicon-containing raw material contains at least one of tetraethoxysilane and sodium silicate.

14. The method for producing a silicon compound-containing liquid according to claim 12, characterized in that the acidic aqueous solution contains at least one of carboxylic acid, hydroxy acid, hydrochloric acid, sulfuric acid, and phosphoric acid.

15. The method for producing a silicon compound-containing liquid according to claim 12, characterized in that the organic nitrogen compound contains at least one of a primary amine, a secondary amine, and a quaternary ammonium salt.

16. A silicon compound-containing material containing a silicon compound, which has a 900 cm －１ More than 1000cm －１ The maximum absorption intensity in the following wavenumber band is designated as P1, and 1000 cm －１ Super 1100cm －１ The maximum absorption intensity in the following wavenumber band is designated as P2, and the intensity ratio of P1 to P2: P1 / P2 is 0.9 to 1.5, and further, 2800 cm －１ More than 4000cm －１ A silicon compound-containing material characterized by having an absorption maximum intensity P3 in the following wavenumber band.

17. The silicon compound-containing material according to claim 15, characterized in that the intensity ratio P1 / P2 is 1.1 to 1.

4.

18. A silicon compound-containing film, characterized in that it is a silicon compound-containing film formed from the silicon compound-containing material according to claim 16 or 17.

19. A method for producing a silicon compound-containing material, comprising a drying step of adding an acidic aqueous solution to a silicon-containing raw material, stirring the mixture at 15°C or higher and 50°C or lower, and drying the resulting mixture containing a precursor of the silicon compound to produce a silicon compound-containing material.

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