Hollow silica sols containing monovalent alkali metal ions and methods for making the same

Abstract

This invention relates to aqueous sols and organic solvent sols containing highly stable hollow silica particles, and further to methods for improving the stability of the aforementioned sols, which have suffered reduced storage stability, and methods for manufacturing such sols. To this end, a hollow silica sol is provided, containing hollow silica particles with spaces within the outer shell and monovalent alkali metal ions, wherein the molar number of these monovalent alkali metal ions, converted to M₂O (M representing a monovalent alkali metal atom), is 7.12 × 10⁻⁶ moles of SiO₂ in the hollow silica particles. ‑6 ~285×10 ‑6 The sol contains hollow silica particles and monovalent alkali metal ions in a specific ratio. After being stored at 50°C for 48 hours, the average particle size measured by dynamic light scattering (DLS) is within 2.0 times that of the average particle size measured by DLS before storage. The average particle size measured by DLS is 20–150 nm. A stabilization method involves adding monovalent alkali metal ions to the hollow silica sol, where the DLS particle size value is larger than that during manufacturing, in the aforementioned ratio of monovalent alkali metal ions to SiO2 in the hollow silica particles, thereby reducing the increased DLS particle size value.

Description

Technical Field

[0001] The present invention relates to a sol containing hollow silica particles containing monovalent alkali metal ions such as sodium ions dispersed in water or an organic solvent, a method for manufacturing the sol, and a composition for film formation. Background Technology

[0002] Hollow silica particles, which have a silica shell and a space inside the shell, have characteristics such as low refractive index, low thermal conductivity (thermal insulation), and electrical insulation.

[0003] Hollow silica particles consist of a core that is equivalent to a void and a shell that forms the outer side of the core. An aqueous dispersion of hollow silica particles is obtained by forming a silica layer on the outer side of the core in an aqueous medium and then removing the core.

[0004] A silica-based microparticle with cavities inside its shell has been disclosed, characterized by an average particle size in the range of 5–500 nm and a refractive index in the range of 1.15–1.38, wherein silica is represented by SiO2 and inorganic oxides other than silica are represented by MO. X Molar ratio MO X The content of alkali metal oxides, calculated as A2O (A: alkali metal element), is less than 5 ppm in the range of 0.0001 to 0.2 / SiO2 (refer to Patent Document 1).

[0005] Also disclosed is a silica-based microparticle having porous material and / or cavities inside the outer shell layer, characterized in that the ratio (SB / SC) of the specific surface area (SB) of the microparticle, as determined by the BET method, to the specific surface area (SC) shown in the following formula is in the range of 1.1 to 5, the refractive index is in the range of 1.15 to 1.38, the content of alkali metal oxides, calculated as M2O (M: alkali metal element) relative to the silica-based microparticle, is less than 5 ppm, and the content of ammonia and / or ammonium ions, converted to NH3, is less than 1500 ppm relative to the silica-based microparticle (see Patent Document 2).

[0006] SC(m 2 / g)=6000 / Dp(nm)·ρ

[0007] (Where, Dp: average particle size of silica-based microparticles (nm), ρ: density (g / ml).)

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2011-046606

[0011] Patent Document 2: Japanese Patent Application Publication No. 2013-121911 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] This invention relates to aqueous sols and organic solvent sols containing highly stable hollow silica particles, and further to methods for improving the stability of the aforementioned sols, which have been degraded in terms of storage stability, and methods for manufacturing such sols.

[0014] Problem-solving methods

[0015] This invention, as viewpoint 1, is a hollow silica sol containing hollow silica particles with spaces inside the outer shell and monovalent alkali metal ions.

[0016] The molar number of the monovalent alkali metal ion converted to M₂O relative to the molar number of SiO₂ in hollow silica particles is 7.12 × 10⁻⁶. -6 ~285×10 -6 The proportions contain hollow silica particles and monovalent alkali metal ions, where M represents a monovalent alkali metal atom.

[0017] The average particle size of the sol, measured by dynamic light scattering after being stored at 50°C for 48 hours, was within 2.0 times that of the average particle size measured by dynamic light scattering before storage.

[0018] Alternatively, it could be a hollow silica sol containing hollow silica particles with internal spaces and monovalent alkali metal ions, such that the molar ratio of the monovalent alkali metal ions (converted to M₂O) to the SiO₂ of the hollow silica particles is 7.12 × 10⁻⁶. -6 ~285×10 -6 The proportions contain hollow silica particles and monovalent alkali metal ions, where M represents a monovalent alkali metal atom. After the sol is stored at 50°C for 48 hours, the particle size value by dynamic light scattering is within 2.0 times that before storage.

[0019] Viewpoint 2 is a hollow silica sol as described in viewpoint 1, wherein the monovalent alkali metal ion is a sodium ion.

[0020] Viewpoint 3 refers to hollow silica sol as described in viewpoint 1 or 2, with an average particle size of 20–150 nm as measured by dynamic light scattering.

[0021] Viewpoint 4 is a hollow silica sol as described in any one of views 1 to 3, which further contains an amine, wherein the amine is 0.001 to 10% by mass of SiO2 relative to the hollow silica particles.

[0022] Viewpoint 5 is a hollow silica sol as described in viewpoint 4, wherein the amine is at least one amine selected from primary amines, secondary amines, and tertiary amines having 1 to 10 carbon atoms.

[0023] Viewpoint 6 is a hollow silica sol as described in viewpoint 4 or 5, wherein the amine is a water-soluble amine with a water solubility of 80 g / L or more.

[0024] Viewpoint 7 is a hollow silica sol as described in any one of views 1 to 6, wherein the hollow silica particles contain aluminum atoms forming aluminosilicate sites, which are bonded to the surface of the hollow silica particles. The mass of these aluminum atoms, converted to Al2O3, is in the range of 100 to 20,000 ppm (A) relative to the mass of SiO2 in the hollow silica particles. This mass of aluminum atoms is a value determined by a leaching method.

[0025] Alternatively, it may be a hollow silica sol as described in any one of viewpoints 1 to 6, wherein the hollow silica particles contain aluminum atoms forming aluminosilicate sites, with the proportion A, calculated by leaching, relative to 1g of SiO2 in Al2O3, being 100 to 20000 ppm, and the mass of these aluminum atoms being bonded to the surface of the hollow silica particles.

[0026] Viewpoint 8 refers to hollow silica sol as described in viewpoint 7, wherein in the determination of the leaching method for leaching aluminum atoms from a compound containing aluminum atoms bonded to the surface of hollow silica particles, an aqueous solution selected from at least one inorganic acid chosen from sulfuric acid, nitric acid, and hydrochloric acid is used.

[0027] Alternatively, as described in viewpoint 7, in the leaching method for determining hollow silica sol, hollow silica particles are leached with an aqueous solution of at least one inorganic acid selected from sulfuric acid, nitric acid, and hydrochloric acid. The compound containing aluminum atoms bonded to the surface of the hollow silica particles is converted to Al2O3 and expressed as a proportion A relative to 1g of SiO2 of the hollow silica particles.

[0028] Viewpoint 9 refers to the hollow silica sol described in viewpoints 7 or 8, wherein the mass of aluminum atoms present in the hollow silica particles as Al2O3 is expressed as a ratio B of 120–50,000 ppm relative to the mass of SiO2 in the hollow silica particles. This mass of aluminum atoms is determined by dissolving the hollow silica particles in an aqueous hydrofluoric acid solution, and the ratio A / ratio B is 0.002–1.0.

[0029] Alternatively, as described in viewpoint 7 or 8, hollow silica sol is combined according to a ratio B of 120 to 50,000 ppm of aluminum atoms present in the hollow silica particles as Al2O3, as determined by dissolution method using hydrofluoric acid aqueous solution, with the ratio of A / B being 0.002 to 1.0.

[0030] Viewpoint 10 is a hollow silica sol as described in any one of views 1 to 9, containing hollow silica particles in a ratio of [specific surface area C of silica particles obtained by the BET method, i.e., nitrogen adsorption method] / [specific surface area D of silica particles calculated by transmission electron microscopy] of 1.40 to 5.00.

[0031] Viewpoint 11 is a hollow silica sol as described in any one of views 1 to 10, wherein the hollow silica particles contain a surface charge of 5 to 250 μeq / g of hollow silica particles per 1g, converted from SiO2.

[0032] Or, as described in any one of viewpoints 1 to 10, hollow silica sol containing hollow silica particles in which the surface charge of SiO2 is 5 to 250 μeq / g per 1g.

[0033] Viewpoint 12 is a hollow silica sol as described in any one of views 1 to 11, wherein the hollow silica particles further comprise hollow silica particles coated with at least one silane compound selected from the compounds shown in formula (1) and formula (2).

[0034] R 1 a Si(R 2 ) 4-a Equation (1)

[0035] [R] 3 b Si(R 4 ) 3-b 2Y c Equation (2)

[0036] In equation (1),

[0037] R 1 These are groups bonded to silicon atoms, and can independently represent alkyl, haloalkyl, alkenyl, aryl, or organic groups having an epoxy, (meth)acryloyl, mercapto, amino, urea, polyether, carboxyl, protected carboxyl, carboxyl-generating, imide, or cyano group and bonded to silicon atoms via Si-C bonds, or combinations of these groups.

[0038] R2 These are groups or atoms bonded to silicon atoms, which independently represent alkoxy, acyloxy, hydroxyl, or halogen atoms having one or more carbon atoms, or combinations of these groups.

[0039] a represents an integer from 1 to 3.

[0040] In equation (2),

[0041] R 3 These are groups bonded to silicon atoms, and can independently represent alkyl, haloalkyl, alkenyl, aryl, or organic groups having an epoxy, (meth)acryloyl, mercapto, amino, urea, polyether, carboxyl, protected carboxyl, carboxyl-generating, imide, or cyano group and bonded to silicon atoms via Si-C bonds, or combinations of these groups.

[0042] R 4 These are groups or atoms bonded to silicon atoms, which independently represent alkoxy, acyloxy, hydroxyl, or halogen atoms having one or more carbon atoms, or combinations of these groups.

[0043] Y is a group or atom bonded to a silicon atom, representing an alkylene group, an NH group, or an oxygen atom.

[0044] b represents an integer from 1 to 3, and c represents an integer of 0 or 1.

[0045] Viewpoint 13 is a hollow silica sol as described in any one of Viewpoints 1 to 12, wherein the dispersion medium is water, an alcohol, ketone, ether, amide, urea, or ester having 1 to 10 carbon atoms.

[0046] Viewpoint 14 is a film-forming composition containing hollow silica particles derived from any one of views 1 to 13, and an organic resin or polysiloxane.

[0047] Viewpoint 15 is a membrane that has a visible light transmittance of 80% or more, obtained from the membrane forming composition described in viewpoint 14.

[0048] Viewpoint 16 is a method for manufacturing hollow silica sol according to any one of views 1 to 13, comprising the following steps (I) to (II):

[0049] (I) Process: The process of preparing hollow silica sol containing a dispersion medium.

[0050] (II) Step: Add monovalent alkali metal ions to the hollow silica sol from step (I), and adjust the molar ratio of the monovalent alkali metal ions (converted to M₂O) to the SiO₂ content of the hollow silica particles to 7.12 × 10⁻⁶. -6 ~285×10 -6The proportion, where M represents a monovalent alkali metal atom.

[0051] Viewpoint 17 is a method for manufacturing hollow silica sol as described in viewpoint 16, wherein in step (II), the monovalent alkali metal ion is sodium ion.

[0052] Viewpoint 18 is a method for manufacturing hollow silica sol as described in viewpoint 17, wherein the sodium ion content in step (II) is adjusted by contacting the hollow silica sol obtained in step (I) with a cation exchange resin or by adding a sodium source.

[0053] Viewpoint 19 is a method for manufacturing hollow silica sol as described in viewpoint 17, wherein in step (II), the addition of the sodium source is the addition of sodium hydroxide.

[0054] Viewpoint 20 is a method for manufacturing hollow silica sol as described in any one of views 16 to 19, wherein the dispersion medium in steps (I) and (II) is water, an alcohol, ketone, ether, amide, urea, or ester having 1 to 10 carbon atoms.

[0055] Viewpoint 21 is a method for manufacturing hollow silica sol as described in any one of views 16 to 20, wherein at least one step selected from (i) to (iv) below is added to step (I), step (II), or both of these steps.

[0056] (i): Adding amines to hollow silica sol

[0057] (ii): Sodium aluminate is added as an aluminum source and heated to form aluminosilicate sites in hollow silica particles.

[0058] (iii): Replace the dispersion medium with another dispersion medium.

[0059] (iv): The hollow silica particles are then coated with at least one silane compound selected from formula (1) and formula (2).

[0060] Viewpoint 22 is a stabilization method for the hollow silica sol described in viewpoint 1. It is a method for stabilizing hollow silica sol containing hollow silica particles with space within a shell. The method is characterized by adding the monovalent alkali metal ions to the hollow silica sol, where the average particle size, as measured by dynamic light scattering, has increased compared to the manufacturing process. This results in the molar number of the monovalent alkali metal ions (converted to M₂O) relative to the molar number of SiO₂ in the hollow silica particles of the hollow silica sol being 7.12 × 10⁻⁶. -6 ~285×10 -6 The molar ratio of [specific molar ratio] causes a decrease in the increased average particle size measured by dynamic light scattering, where M represents a monovalent alkali metal atom.

[0061] Alternatively, the stabilization method for hollow silica sol described in viewpoint 1 is a method for stabilizing hollow silica sol containing hollow silica particles with space inside the shell. Its characteristic is that monovalent alkali metal ions are added to the hollow silica sol, whose particle size value has increased compared to the manufacturing process, such that the molar ratio of the monovalent alkali metal ions (converted to M2O) to the SiO2 of the hollow silica particles in the hollow silica sol is 7.12 × 10⁻⁶. -6 ~285×10 -6 The molar ratio of M / M reduces the particle size value of the increased dynamic light scattering method, where M represents a monovalent alkali metal atom.

[0062] Viewpoint 23 is a stabilization method for hollow silica sol as described in viewpoint 22, wherein the monovalent alkali metal ion is a sodium ion.

[0063] Invention Effects

[0064] Because dispersions containing hollow silica particles (hollow silica sol) are stable, hollow silica sols with non-agglomeration and minimal particle size variation can be obtained. Highly stable hollow silica sols, due to minimal particle size variation during film formation, can reduce surface roughness and improve transparency.

[0065] The concentration of alkali metal ions (e.g., sodium ions) in hollow silica sol is preferably within a certain range. Excessive concentration can lead to leaching of alkali metal ions from the film or problems with the film's electrical insulation. Conversely, insufficient concentration results in voids within the hollow silica particles. Since hollow silica particles have a lower specific gravity than solid silica particles, they tend to aggregate and condense due to low interparticle repulsion. In such cases, a certain amount of alkali metal ions (e.g., sodium ions) is required to increase the interparticle repulsion.

[0066] In this invention, the stability is improved by combining amine molecules and sodium ions as the alkali component. This can be attributed to the presence of amine molecules and sodium ions with large volumes on the particle surface, which further enhances the repulsive force between silica particles.

[0067] Furthermore, in this invention, aluminum silicate sites can be formed by doping aluminum atoms on the surface of silicon dioxide particles. The stabilization of the aluminum silicate sites can be improved by the presence of alkali metals that are relatively negatively charged aluminum atoms, which are ions. Detailed Implementation

[0068] This invention relates to a hollow silica sol containing hollow silica particles with internal spaces and monovalent alkali metal ions. The molar number of these monovalent alkali metal ions, converted to M₂O (where M represents a monovalent alkali metal atom), relative to the molar number of SiO₂ in the hollow silica particles is 7.12 × 10⁻⁶. -6 ~285×10 -6 The proportions of these components are such that the dynamic light scattering particle size (average particle size) of the sol after storage at 50°C for 48 hours is within 2.0 times that of the dynamic light scattering particle size before storage.

[0069] Hollow silica particles have a silica shell with a space inside the shell. Hollow silica can be obtained by forming a silica-based shell on the surface of a core portion, which is equivalent to a "template," in a dispersion medium, and then removing the core portion.

[0070] Hollow silica particles require stable dispersion in a dispersion medium. However, the presence of silanol groups, organic functional groups, and aluminosilicate sites formed by aluminum doping on the surface of hollow silica particles can stabilize them by introducing monovalent alkali metal ions. The silanol groups, organic functional groups, and aminosilicate sites contain polymeric functional groups such as hydroxyl groups. The interaction of these polymeric functional groups leads to weak condensation (entanglement) or hydrogen bonding between particles, causing cross-linking and resulting in particle instability or increased particle size. However, it can be considered that adding monovalent alkali metal ions to these polymeric functional groups, thereby changing the morphology of the hydroxyl groups, can suppress the main cause of instability. These polymeric functional groups sometimes promote instability through heating. The stability of hollow silica sol can be evaluated by confirming its stability at 50°C for 48 hours.

[0071] Examples of monovalent alkali metal ions include, for example, lithium ions, sodium ions, potassium ions, rubidium ions, and cesium ions, with lithium ions, sodium ions, and potassium ions being preferred, and sodium ions being particularly preferred.

[0072] Regarding the content of monovalent alkali metal ions, the molar ratio obtained by converting monovalent alkali metal ions into M2O (where M represents monovalent alkali metal atoms) relative to the mass of SiO2 per unit mass of hollow silica particles in the dispersion (sol) can be 7.12 × 10⁻⁶. -6 ~285×10 -6 Or 7.12×10 -6 ~237×10 -6 Or 7.12×10 -6 ~190×10 -6 Or 20×10 -6~285×10 -6 Or 50×10 -6 ~285×10 -6 .

[0073] In addition, the molar ratio of the content of the aforementioned monovalent alkali metal ions relative to the mass of SiO2 of hollow silica particles in the dispersion (sol), which is obtained by converting the monovalent alkali metal ions into M2O (where M represents a monovalent alkali metal atom), can be set to an amount equivalent to 15ppm to 600ppm, or 15ppm to 500ppm, or 15ppm to 400ppm.

[0074] The hollow silica sol of the present invention has an average particle size that can be set within the range of 20 to 150 nm, as measured by dynamic light scattering. Furthermore, the particle size measured by dynamic light scattering after storing the hollow silica sol at 50°C for 48 hours is within 2.0 times, 1.5 times, or 1.1 times that before storage. The present invention also includes a particle size measured by dynamic light scattering after storage at 50°C for 48 hours that is smaller than that before storage. Therefore, the lower limit value can be set to 0.8 times or more, 0.9 times or more, or 1.0 times or more.

[0075] In this invention, by including sodium ions within the aforementioned range, the stability of the hollow silica sol can be ensured, thus allowing sodium ions to be present within this range before the sol containing hollow silica particles becomes unstable. Furthermore, by adding the aforementioned sodium ions to the sol containing unstable hollow silica particles, the agglomerated state of the hollow silica particles is released, allowing the particle size range of the hollow silica particles to return to its pre-agglomerated state.

[0076] In this invention, aluminum atoms can be represented as Al2O3 by leaching an aqueous solution of at least one inorganic acid selected from sulfuric acid, nitric acid, and hydrochloric acid onto the surface of silica particles. That is, aluminum atoms, converted to Al2O3 and present on the surface of hollow silica particles, are bonded to the silica particles at a ratio (A) of 100–20000 ppm / SiO2, or 100–15000 ppm / SiO2, or 100–10000 ppm / SiO2, or 200–5000 ppm / SiO2, or 500–5000 ppm / SiO2, or 800–3000 ppm / SiO2 relative to the mass of SiO2 in the hollow silica particles. The presence of aminosilicate sites on the surface of the silica particles is important for dispersion in solvents or resins.

[0077] Aluminum atoms present as aluminosilicates on the surface of silica particles are leached (dissolved) from the silica particles by an aqueous solution of at least one inorganic acid selected from sulfuric acid, nitric acid, and hydrochloric acid, with the aluminum atoms having a structure similar to aluminum salts, aluminum oxides, or aluminum hydroxides. The aluminum atoms in the solution can be determined using an ICP emission spectrometer and converted to Al₂O₃. In particular, leaching (elution) with an aqueous nitric acid solution is used. The aqueous nitric acid solution used for leaching can be used in the pH range of 0.5–4.0, 0.5–3.0, 0.5–2.0, or 1.0–1.5; typically, an aqueous nitric acid solution with a pH of 1.0 can be used. For example, 100 mL of the above-mentioned aqueous nitric acid solution can be added to 1 g of silica and maintained at a temperature of 20–70°C or 40–60°C for 10–24 hours to dissolve aluminum compounds from the surface of the silica particles, which can then be used as an analytical sample.

[0078] In this invention, the so-called silica particle surface can be defined as the region where aluminum compounds can be dissolved through the above-mentioned leaching. The solvent is evaporated from the silica sol, and the silica gel dried at 250°C is ground into silica powder. 20 mL of a pH 1.0 nitric acid aqueous solution is added to 0.2 g of this silica powder, and the mixture is shaken thoroughly. After maintaining the mixture in a constant temperature bath at 50°C for 17 hours, it is centrifuged and filtered. The aluminum content in the filtrate obtained from the centrifugation is determined using an ICP emission spectrometer. The aluminum content, converted to Al2O3, is divided by the mass of the silica powder to calculate the amount of aluminum bonded to the silica particle surface (Al2O3 / SiO2) (ppm).

[0079] Furthermore, even when aluminosilicates form on the surface of silica particles, depending on the manufacturing method, aluminosilicates can sometimes form not only on the surface but also inside the silica particles. Converted to Al2O3, the ratio (B) of the mass of aluminum atoms present in the hollow silica particles (including the surface and interior) to the mass of SiO2 in the hollow silica particles is 120–50000 ppm / SiO2, or 500–20000 ppm / SiO2, or 500–10000 ppm / SiO2, or 1000–5000 ppm / SiO2, or 1000–4000 ppm / SiO2, and they are bonded to the silica particles in such a ratio.

[0080] The ratio (A) / ratio (B) can be set in the range of 0.001 to 1.0, or 0.01 to 1.0, or 0.1 to 1.0, or 0.3 to 1.0, or 0.4 to 1.0. The ratio (A) / ratio (B) is the ratio of aluminum present on the surface of the silica particles and in the silica particles as a whole.

[0081] The aluminum atoms present in the silica particles as a whole can be determined by dissolving the silica particles in an aqueous hydrofluoric acid solution and then converted to Al2O3. That is, the aluminum atoms present as aluminosilicates in the silica particles can be dissolved in an aqueous hydrofluoric acid solution, and the concentration of the dissolved aluminum atoms can be measured using an ICP emission spectrometer and converted to Al2O3, which is then expressed as the aluminum atoms present in the silica particles. The aqueous hydrofluoric acid solution only needs to be of a concentration sufficient to dissolve the silica particles; for example, a 48% by mass aqueous hydrofluoric acid solution can be used. Furthermore, to completely dissolve the silica particles, the amount of aqueous hydrofluoric acid used must be at least an equivalent to the silica particles, preferably 1.1 to 1000 equivalents in molar ratio.

[0082] Thus, by forming aluminosilicate sites on the surface of silica particles, the amount of negative charge (surface charge) of the hollow silica particles present on the surface of silica particles can be measured in SiO2 as 5–250 μeq / g, or 5–150 μeq / g, or 5–100 μeq / g, or 25–150 μeq / g, or 25–100 μeq / g per gram.

[0083] The aforementioned hollow silica particles can be obtained as hollow silica sol dispersed in a dispersion medium. A sol containing hollow silica particles dispersed in a dispersion medium can be obtained, which is a hollow silica sol with an average particle size of 20–150 nm obtained by dynamic light scattering.

[0084] Hollow silica is obtained by forming a shell mainly composed of silica on the surface of a core portion, which is equivalent to a "template", in a dispersion medium, and then removing the core portion. In this state, it is a hollow silica aqueous sol.

[0085] The resulting hollow silica aqueous sol can be replaced by an alcohol solvent as an organic solvent. Preferably, the alcohol solvent is an alcohol with 1 to 5 carbon atoms having an ether bond, such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, etc. Then, after coating with a silane compound as needed, further solvent replacement with other organic solvents can be performed.

[0086] In this invention, alcohols, ketones, ethers, amides, ureas, and esters having 1 to 10 carbon atoms can be listed as organic solvents.

[0087] Alcohols with 1 to 10 carbon atoms are aliphatic alcohols, including primary, secondary, and tertiary alcohols. Furthermore, these alcohols can also be polyols, such as diols and triols.

[0088] Examples of primary monohydric alcohols include methanol, ethanol, 1-propanol, 1-butanol, and 1-hexanol.

[0089] Examples of monohydric secondary alcohols include 2-propanol, 2-butanol, cyclohexanol, propylene glycol monomethyl ether, and propylene glycol monoethyl ether.

[0090] Examples of monotertiary alcohols include tert-butanol.

[0091] Examples of diols include methane glycol, ethylene glycol, and propylene glycol.

[0092] Examples of trihydric alcohols include glycerol.

[0093] Aliphatic ketones are preferred as ketones having 1 to 10 carbon atoms. Examples include acetone, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, methyl isobutyl ketone, methyl pentyl ketone, cyclohexanone, and methyl cyclopentanone.

[0094] Aliphatic ethers are preferred as ethers having 1 to 10 carbon atoms. Examples include dimethyl ether, ethyl methyl ether, diethyl ether, tetrahydrofuran, and 1,4-dioxane.

[0095] Examples of amides with 5 to 20 carbon atoms include N-methylpyrrolidone, dimethylacetamide, and diethylacetamide.

[0096] Examples of ureas with 5 to 20 carbon atoms include tetramethylurea and 1,3-dimethyl-2-imidazolinone.

[0097] Aliphatic esters are preferred as esters having 1 to 10 carbon atoms. Examples include methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl acrylate, ethyl acrylate, propyl acrylate, dimethyl maleate, diethyl maleate, dipropyl maleate, dimethyl adipate, diethyl adipate, and dipropyl adipate.

[0098] In the hollow silica aqueous sol and hollow silica organic solvent sol used as the above raw materials, the average particle size of the hollow silica particles, as determined by dynamic light scattering (DLS method), can be in the range of 20-150 nm, 30-150 nm, 40-150 nm, 50-150 nm, 50-120 nm, or 50-100 nm.

[0099] In addition, the average primary particle size observed by a transmission electron microscope can be in the range of 20–150 nm, or 30–150 nm, or 40–150 nm, or 50–150 nm, or 50–120 nm, or 50–100 nm.

[0100] In addition, the specific surface area (C) obtained by the BET method (nitrogen adsorption method) can be set to 18–200 m². 2 / g, or 50-160m 2 / g, or 60-160m 2 / g, or 70-160m 2 / g, or 80-150m 2 / g.

[0101] In addition, the specific surface area (D) calculated from a transmission electron microscope can be set to 18–136 m². 2 / g, or 18-90m 2 / g, or 18-68m 2 / g, or 18-54m 2 / g, or 18-27m 2 / g, or 18-23m 2 / g.

[0102] Furthermore, the ratio of [specific surface area (C) measured by the BET method (nitrogen adsorption method)] to [specific surface area (D) calculated by transmission electron microscopy] can be set to a range of 1.40–5.00, 1.40–3.50, 1.50–3.00, or 1.50–2.80. When the value of (C) / (D) is close to 1.0, it indicates solid silica particles with no space inside the shell of the silica particles; when the value of (C) / (D) exceeds 1.0, it indicates hollow silica particles with space inside the shell of the silica particles.

[0103] Furthermore, the thickness of the shell of hollow silica particles, as observed by a transmission electron microscope, can be manufactured in the range of 3.0–15.0 nm, 4.0–12.0 nm, or 5.0–10.0 nm.

[0104] Moreover, the refractive index of the aforementioned hollow silica particles can be obtained in the range of 1.20–1.45, 1.20–1.40, or 1.25–1.40.

[0105] In addition, the concentration of SiO2 particles in hollow silica sol is 1–50% by mass or 5–40% by mass, and it can typically be used at 10–30% by mass.

[0106] The pH value of the above sol can be adjusted within the range of acidity to alkalinity. Adjustment to acidity is achieved by adding inorganic or organic acids. Adjustment to alkalinity is achieved by adding inorganic or organic bases. As an organic base, an amine can be added for the purpose of adjusting pH and surface charge. The pH is set on the acidic side to be above 1 and below 7, and on the alkaline side to be above 7 and below 13.

[0107] The aqueous sol of hollow silica can be set to a pH range of, for example, 2.0–6.0 or 2.0–4.5 before the addition of amine. By adding amine, the pH range can be adjusted to, for example, 3.0–10.0 or 3.0–9.0.

[0108] In the case of organic solvent sol, the pH mentioned above is the pH when the same mass of pure water as the organic solvent sol is mixed at a 1:1 ratio. The pH can be measured when using an organic solvent that is miscible with water, but it is preferable to measure the pH in advance during the methanol solvent sol stage when the solvent is subsequently replaced with a hydrophobic organic solvent.

[0109] For example, when the dispersion medium, such as methanol sol or propylene glycol monomethyl ether sol, is a hydrophilic organic solvent, the solution obtained by mixing pure water and sol in a mass ratio of 1:1 can be measured. When the dispersion medium, such as methyl ethyl ketone sol, is a hydrophobic organic solvent, the solution obtained by mixing pure water, methanol, and methyl ethyl ketone sol in a mass ratio of 1:1:1 can be measured.

[0110] Hollow silica organic solvate involves solvent replacement of an aqueous medium with an alcohol solvent having 1 to 5 carbon atoms, followed by solvent replacement with an organic solvent. However, residual water may remain during this process. In the alcohol sol stage of hollow silica, the sol may contain, for example, 0.1 to 3.0% by mass or 0.1 to 1.0% by mass of residual water. Furthermore, in the organic solvate stage of hollow silica (where the dispersion medium is an organic solvent other than alcohol), the sol may contain 0.01 to 0.5% by mass of residual water.

[0111] In addition, the viscosity in hollow silica organic solvent sol can be set to the range of 1.0 to 10.0 mPa·s.

[0112] The hollow silica sol of the present invention may contain amines.

[0113] The amines used in this invention can be water-soluble amines with a water solubility of 80 g / L or more, or 100 g / L or more.

[0114] The hollow silica aqueous sol used as a raw material, or the hollow silica organic solvate obtained by solvent displacement, may contain amines, or amines and ammonia. Amines may be added and contained in the range of 0.001 to 10% by mass, 0.01 to 10% by mass, or 0.1 to 10% by mass relative to the SiO2 of the hollow silica particles. Furthermore, these basic components, such as amines, or amines and ammonia, may be expressed as the total nitrogen content in the hollow silica particle organic solvate, for example, in the range of 10 to 100,000 ppm, 100 to 10,000 ppm, 100 to 3,000 ppm, or 100 to 2,000 ppm, typically in the range of 200 to 2,000 ppm.

[0115] The amines mentioned above can include aliphatic amines and aromatic amines, but aliphatic amines are preferred. The amine can be at least one selected from primary, secondary, and tertiary amines having 1 to 10 carbon atoms. These amines are water-soluble and are at least one selected from primary, secondary, and tertiary amines having 1 to 10 carbon atoms.

[0116] For example, primary amines include monomethylamine, monoethylamine, monopropylamine, monoisopropylamine, monobutylamine, monoisobutylamine, monosec-butylamine, monotert-butylamine, monomethanolamine, monoethanolamine, monopropanolamine, monoisopropanolamine, monobutanolamine, monoisobutanolamine, monosec-butanolamine, monotert-butanolamine, etc.

[0117] As secondary amines, examples include dimethylamine, diethylamine, dipropylamine, diisopropylamine, N-methylethylamine, N-ethylisobutylamine, dimethanolamine, diethanolamine, dipropanolamine, diisopropanolamine, N-methanolethylamine, N-methylethanolamine, N-ethanolisobutylamine, and N-ethylisobutylamine.

[0118] As tertiary amines, examples include trimethylamine, triethylamine, tripropylamine, triisopropylamine, tributylamine, triisobutylamine, trisec-butylamine, tritert-butylamine, trimethanolamine, triethanolamine, tripropanolamine, triisopropanolamine, tributanolamine, triisobutanolamine, trisec-butanolamine, tritert-butanolamine, tripentylamine, ethyl 3-(dimethylamino)acrylate, ethyl 2-(dimethylamino)acrylate, ethyl 2-(dimethylamino)methacrylate, ethyl 2-(diethylamino)acrylate, and ethyl 2-(diethylamino)methacrylate.

[0119] For the water solubility of the aforementioned amines, a concentration of 80 g / L or higher or 100 g / L or higher is preferred. Primary and secondary amines are preferred among these amines; from the viewpoint of low volatility and high solubility, secondary amines are preferred, such as diisopropylamine and diethanolamine.

[0120] In this invention, by containing the aforementioned amine, the surface charge of the hollow silica particles, converted to SiO2, can be set to 5 μeq / g or more, or 25 μeq / g or more per 1g. Typically, it can be set in the range of 5–250 μeq / g, 25–250 μeq / g, 25–100 μeq / g, or 25–80 μeq / g.

[0121] In this invention, by adjusting the type and amount of the amine, the surface charge of the hollow silica particles can be adjusted to any desired surface charge.

[0122] In this invention, the surface of hollow silica particles can be coated with silane compounds.

[0123] As the above-mentioned silane compound, it can be coated with a hydrolysate of at least one silane compound selected from formula (1) and formula (2).

[0124] In equation (1), R 1 These are alkyl, haloalkyl, alkenyl, aryl, or organic groups having polyether, epoxy, (meth)acryloyl, mercapto, amino, urea, or cyano groups, and are bonded to silicon atoms via Si-C bonds. 2 These represent alkoxy, acyloxy, or halogen groups, respectively, with 'a' representing an integer from 1 to 3.

[0125] In equation (2), R 3 They are alkyl groups with 1 to 3 carbon atoms or aryl groups with 6 to 30 carbon atoms, and are bonded to silicon atoms through Si-C bonds. 4 They represent alkoxy, acyloxy, or halogen groups, respectively; Y represents alkylene, NH, or oxygen atom; b is an integer from 1 to 3; c is an integer from 0 to 1; and d is an integer from 1 to 3.

[0126] The alkyl groups mentioned above are alkyl groups with 1 to 18 carbon atoms, and examples include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, 1-methyl-cyclopropyl, 2-methyl-cyclopropyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl, 1,2-dimethyl-n-propyl, 2,2-dimethyl-n-propyl, 1-ethyl-n-propyl, cyclopentyl, 1-methyl-cyclobutyl, 2-methyl-cyclobutyl, 3-methyl-cyclobutyl 1,2-Dimethyl-cyclopropyl, 2,3-Dimethyl-cyclopropyl, 1-Ethyl-cyclopropyl, 2-Ethyl-cyclopropyl, n-Hexyl, 1-Methyl-n-pentyl, 2-Methyl-n-pentyl, 3-Methyl-n-pentyl, 4-Methyl-n-pentyl, 1,1-Dimethyl-n-butyl, 1,2-Dimethyl-n-butyl, 1,3-Dimethyl-n-butyl, 2,2-Dimethyl-n-butyl, 2,2-Dimethyl-n-butyl, 3,3-Dimethyl-n-butyl, 1-Ethyl-n-butyl, 2-Ethyl-n-butyl, 1,1,2-Trimethyl-n-propyl 1,2,2-Trimethyl-n-propyl, 1-Ethyl-1-methyl-n-propyl, 1-Ethyl-2-methyl-n-propyl, Cyclohexyl, 1-Methyl-cyclopentyl, 2-Methyl-cyclopentyl, 3-Methyl-cyclopentyl, 1-Ethyl-cyclobutyl, 2-Ethyl-cyclobutyl, 3-Ethyl-cyclobutyl, 1,2-Dimethyl-cyclobutyl, 1,3-Dimethyl-cyclobutyl, 2,2-Dimethyl-cyclobutyl, 2,3-Dimethyl-cyclobutyl, 2,4-Dimethyl-cyclobutyl, 3,3-Dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl The following are examples of cyclopropyl, 1-isopropylcyclopropyl, 2-isopropylcyclopropyl, 1,2,2-trimethylcyclopropyl, 1,2,3-trimethylcyclopropyl, 2,2,3-trimethylcyclopropyl, 1-ethyl-2-methylcyclopropyl, 2-ethyl-1-methylcyclopropyl, 2-ethyl-2-methylcyclopropyl and 2-ethyl-3-methylcyclopropyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, octadecyl, etc., but not limited to these.

[0127] In addition, alkylene groups can be listed as those derived from the aforementioned alkyl groups.

[0128] The aryl groups mentioned above are aryl groups with 6 to 30 carbon atoms, and examples include phenyl, naphthyl, anthracene, pyrene, etc.

[0129] Alkenyl groups have 2 to 10 carbon atoms and include, for example, vinyl, 1-propenyl, 2-propenyl, 1-methyl-1-vinyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl, 3-pentenyl, 4-pentenyl, 1-n-propylvinyl, 1-methyl-1-butenyl, 1-methyl-2-butenyl, 1-methyl-3-butenyl, 2-ethyl-2-propenyl, 2-methyl-1-butenyl, 2-methyl-2-butenyl, and 2-methyl-3-butenyl. 3-Methyl-1-butenyl, 3-methyl-2-butenyl, 3-methyl-3-butenyl, 1,1-dimethyl-2-propenyl, 1-isopropylvinyl, 1,2-dimethyl-1-propenyl, 1,2-dimethyl-2-propenyl, 1-cyclopentenyl, 2-cyclopentenyl, 3-cyclopentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 1-methyl-2-pentenyl, 1-methyl-3-pentenyl, 1-methyl-4-pentenyl, 1-n-butylvinyl, 2-methyl-1-pentenyl, 2-methyl-2-pentenyl, etc., but not limited to these.

[0130] The alkoxy groups mentioned above can be alkoxy groups with 1 to 10 carbon atoms, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, 1-methyl-n-butoxy, 2-methyl-n-butoxy, 3-methyl-n-butoxy, 1,1-dimethyl-n-propoxy, 1,2-dimethyl-n-propoxy, 2,2-dimethyl-n-propoxy, 1-ethyl-n-propoxy, n-hexyloxy, etc., but are not limited to these.

[0131] The aforementioned acyloxy group is an acyloxy group having 2 to 10 carbon atoms, and examples include, but are not limited to, methyl carbonyloxy, ethyl carbonyloxy, n-propyl carbonyloxy, isopropyl carbonyloxy, n-butyl carbonyloxy, isobutyl carbonyloxy, sec-butyl carbonyloxy, tert-butyl carbonyloxy, n-pentyl carbonyloxy, 1-methyl-n-butyl carbonyloxy, 2-methyl-n-butyl carbonyloxy, 3-methyl-n-butyl carbonyloxy, 1,1-dimethyl-n-propyl carbonyloxy, 1,2-dimethyl-n-propyl carbonyloxy, 2,2-dimethyl-n-propyl carbonyloxy, 1-ethyl-n-propyl carbonyloxy, n-hexyl carbonyloxy, 1-methyl-n-pentyl carbonyloxy, 2-methyl-n-pentyl carbonyloxy, etc.

[0132] Examples of halogen groups include fluorine, chlorine, bromine, and iodine.

[0133] As an organic group containing a polyether group, polyetherpropyl groups containing an alkoxy group can be listed. For example, (CH3O)3SiC3H6(OC2H4)nOCH3. n can be used in the range of 1 to 100 or 1 to 10.

[0134] Organic groups with epoxy groups can be listed as such as 2-(3,4-epoxycyclohexyl)ethyl, 3-glycidoxypropyl, etc.

[0135] The (meth)acryloyl group mentioned above refers to both acryloyl and methacryloyl groups. Examples of organic groups containing a (meth)acryloyl group include 3-methacryloyloxypropyl and 3-acryloyloxypropyl.

[0136] Organic groups containing thiol groups include, for example, 3-mercaptopropyl.

[0137] Organic groups containing amino groups include, for example, 2-aminoethyl, 3-aminopropyl, N-2-(aminoethyl)-3-aminopropyl, N-(1,3-dimethyl-butylidene)aminopropyl, N-phenyl-3-aminopropyl, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyl, etc.

[0138] Organic groups containing a urea group include, for example, 3-ureopropyl.

[0139] Organic groups containing a cyano group include, for example, 3-cyanopropyl.

[0140] Formula (2) above is preferably a compound that can form trimethylsilyl groups on the surface of silica particles.

[0141] These compounds can be listed below.

[0142]

[0143] In the above formula, R 12 The alkoxy group can be exemplified by, for example, methoxy or ethoxy. The aforementioned silane compounds can be silane compounds manufactured by Shin-Etsu Chemical Co., Ltd.

[0144] On the surface of silica particles, hydroxyl groups (e.g., silanol groups, if silica particles) react with the aforementioned silane compound, coating the silica particles with the silane compound through siloxane bonds. The reaction can be carried out at temperatures ranging from 20°C to the boiling point of the dispersion medium, for example, from 20°C to 100°C. The reaction time is approximately 0.1 to 6 hours.

[0145] The aforementioned silane compound, used as a coating on the surface of silica particles, can be added to the silica sol at a rate equivalent to 0.1 silicon atoms / nm.2 ~6.0 units / nm 2 The surface of silica particles is coated with a coating amount of silane compound.

[0146] The hydrolysis of the aforementioned silane compounds requires water, but if the sol is made of an aqueous solvent, then this aqueous solvent is used. Water remaining in the solvent after the aqueous medium has been replaced with an organic solvent can be used. For example, water present in quantities of 0.01 to 1% by mass can be used. Furthermore, hydrolysis can be carried out using a catalyst, or it can be carried out without a catalyst.

[0147] In the absence of a catalyst, the silica particles exist as acidic sites on their surface. When a catalyst is used, examples of hydrolysis catalysts include metal chelates, organic acids, inorganic acids, organic bases, and inorganic bases. Examples of metal chelates as hydrolysis catalysts include triethoxymono(acetylacetone)titanium and triethoxymono(acetylacetone)zirconium. Examples of organic acids as hydrolysis catalysts include acetic acid and oxalic acid. Examples of inorganic acids as hydrolysis catalysts include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid. Examples of organic bases as hydrolysis catalysts include pyridine, pyrrole, piperazine, and quaternary ammonium salts. Examples of inorganic bases as hydrolysis catalysts include ammonia, sodium hydroxide, and potassium hydroxide.

[0148] The organic acid is selected from at least one of the following: dialiphatic carboxylic acids, aliphatic hydroxycarboxylic acids, amino acids, and chelating agents. Examples of dialiphatic carboxylic acids include oxalic acid, malonic acid, and succinic acid. Examples of aliphatic hydroxycarboxylic acids include glycolic acid, lactic acid, malic acid, tartaric acid, and citric acid. Examples of amino acids include glycine, alanine, valine, leucine, serine, and threonine. Examples of chelating agents include ethylenediaminetetraacetic acid, L-aspartic-N,N-diacetic acid, and diethylenetriaminetetraacetic acid. Examples of organic acid salts include alkali metal salts, ammonium salts, and amine salts of the above-mentioned organic acids. Examples of alkali metals include sodium and potassium.

[0149] In this invention, a film-forming composition containing the above-mentioned hollow silica organic solvent sol and organic resin or polysiloxane can be obtained.

[0150] Organic resins or polysiloxanes are mixed with thermosetting or photocurable resins to obtain a composition for film formation. Furthermore, a cured product can be prepared by containing curing agents such as amine-based curing agents, anhydride-based curing agents, free radical generating agents (thermal free radical generators, photofree radical generators), or acid generating agents (thermal acid generators or photoacid generators).

[0151] Regarding this composition, a film-forming composition containing an organic resin or polysiloxane and a curing agent can be coated or filled onto a substrate, and a cured product can be formed by heating, light irradiation, or a combination thereof. Examples of organic resins and polysiloxanes (curable resins) include resins having functional groups such as epoxy or (meth)acryloyl groups, as well as isocyanate-based resins. For example, light-curable polyfunctional acrylates are preferred.

[0152] As polyfunctional acrylates, examples include polyfunctional acrylates with 2, 3, 4 or more functional groups in the molecule, such as neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0153] These multifunctional acrylates may also be described as follows.

[0154]

[0155]

[0156]

[0157] The film-forming composition of the present invention may contain a surfactant (leveling agent).

[0158] As surfactants (leveling agents), anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, and silicone surfactants can be used. The surfactant (leveling agent) can be added relative to the organic resin or polysiloxane in the range of 0.01–5 phr or 0.01–1 phr.

[0159] Examples of anionic surfactants used in this invention include sodium and potassium salts of fatty acids, alkylbenzene sulfonates, higher alcohol sulfates, polyoxyethylene alkyl ether sulfates, α-sulfonyl fatty acid esters, α-olefin sulfonates, monoalkyl phosphates, and alkane sulfonates.

[0160] For example, alkylbenzene sulfonates can be listed as sodium salts, potassium salts, and lithium salts, such as C10-C16 sodium alkylbenzene sulfonate, C10-C16 alkylbenzene sulfonic acid, and sodium alkylnaphthalene sulfonate.

[0161] As higher alcohol sulfate salts, there are sodium dodecyl sulfate (sodium lauryl sulfate), triethanolamine lauryl sulfate, and triethanolamine lauryl sulfate, which have 12 carbon atoms.

[0162] As polyoxyethylene alkyl ether sulfates, there are sodium polyoxyethylene styrene phenyl ether sulfate, sodium polyoxyethylene styrene phenyl ether sulfate, sodium polyoxyethylene decyl ether sulfate, sodium polyoxyethylene decyl ether sulfate, sodium polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene tridecyl ether sulfate, sodium polyoxyethylene oleyl hexadecyl ether sulfate, etc.

[0163] As α-olefin sulfonates, there are sodium α-olefin sulfonate, etc.

[0164] Examples of alkane sulfonates include sodium 2-ethylhexyl sulfate.

[0165] Examples of cationic surfactants used in this invention include alkyl trimethylammonium salts, dialkyl dimethylammonium salts, alkyl dimethyl benzylammonium salts, and amine salts.

[0166] Alkyltrimethylammonium salts are quaternary ammonium salts with chloride or bromide ions as their relative ions. Examples include dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, cocoyltrimethylammonium chloride, and alkyl(C16-18)trimethylammonium chloride.

[0167] Dialkyl dimethyl ammonium salts have two lipophilic backbones and two methyl groups. Examples include bis(hydrogenated tallow) dimethyl ammonium chloride. Other examples include dialcyl dimethyl ammonium chloride, dicocoyl alkyl dimethyl ammonium chloride, dihydrogenated tallow alkyl dimethyl ammonium chloride, and dialkyl (C14-18) dimethyl ammonium chloride.

[0168] Alkyl dimethyl benzyl ammonium salts are quaternary ammonium salts having one lipophilic main chain, two methyl groups, and a benzyl group; examples include benzalkonium chloride. Alkyl (C8-18) dimethyl benzyl ammonium chloride is another example.

[0169] As an amine salt agent, the hydrogen atom of ammonia is replaced by one or more hydrocarbon groups, such as N-methylbis(hydroxyethyl)amine fatty acid ester hydrochloride.

[0170] Examples of amphoteric surfactants used in this invention include N-alkyl-β-alanine type alkylamino fatty acid salts, alkyl carboxybetaine type alkyl betaines, and N,N-dimethyldodecylamine oxide type alkylamine oxides. Examples of these include lauryl betaine, stearyl betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazoline betaine, and lauryl dimethylamine oxide.

[0171] The nonionic surfactants used in this invention are selected from polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, alkyl glucosides, polyoxyethylene fatty acid esters, sucrose fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and fatty acid alkanolamides. For example, examples of polyoxyethylene alkyl ethers include polyoxyethylene dodecyl ether (polyoxyethylene lauryl ether), polyoxyethylene alkylene lauryl ether, polyoxyethylene tridecyl ether, polyoxyethylene alkylene tridecyl ether, polyoxyethylene myristyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene oil-based ether, polyoxyethylene stearyl ether, polyoxyethylene behenyl ether, polyoxyethylene-2-ethylhexyl ether, and polyoxyethylene isodecyl ether.

[0172] As polyoxyethylene alkylphenol ethers, there are polyoxyethylene styrene phenyl ethers, polyoxyethylene nonylphenyl ethers, polyoxyethylene styrene phenyl ethers, and polyoxyethylene tribenzylphenyl ethers.

[0173] As alkyl glucosides, there are decyl glucoside, lauryl glucoside, etc.

[0174] As polyoxyethylene fatty acid esters, there are polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene monooleate, polyethylene glycol distearate, polyethylene glycol dioleate, and polypropylene glycol dioleate, etc.

[0175] As sorbitan fatty acid esters, there are sorbitan monocaprylate, sorbitan monolaurate, sorbitan monomyristate, sorbitan monopalmitate, sorbitan monostearate, sorbitan distearate, sorbitan tristearate, sorbitan monooleate, sorbitan trioleate, sorbitan monosesquioleate, and their ethylene oxide adducts, etc.

[0176] As polyoxyethylene sorbitan fatty acid esters, there are polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan triisostearate, etc.

[0177] In addition, as fatty acid alkanolamides, there are coconut oil fatty acid diethanolamide, tallow fatty acid diethanolamide, lauric acid diethanolamide, oleic acid diethanolamide, etc.

[0178] Furthermore, examples include polyoxyethylene polyoxypropylene glycol, polyoxyethylene fatty acid esters and other polyoxyalkyl ethers or polyoxyalkyl glycols, polyoxyethylene hardened castor oil ether, sorbitan fatty acid ester alkyl ether, alkyl polyglucoside, sorbitan monooleate, sucrose fatty acid ester, etc.

[0179] Organosilicon surfactants can be used. Organosilicon surfactants are compounds having repeating units containing siloxane bonds in their main chain. Organosilicon surfactants can be used with a weight-average molecular weight in the range of 500 to 50,000. They can be modified organosilicon surfactants, and structures formed by introducing organic groups into the side chains and / or ends of polysiloxanes are listed. Examples of organic groups include amino, epoxy, alicyclic epoxy, methanol, mercapto, carboxyl, aliphatic ester, aliphatic amide, and polyether groups. Examples of silicone-based surfactants include those with the trade names ToroSilicon DC3PA, ToroSilicon SH7PA, and ToroSilicon.シリコーンDC11PA, トーレシリコーンSH21PA, トーレシリコーンSH28PA, トーレシリコーンSH 29PA, Torotron SH30PA, Torotron SH8400 (the above products are manufactured by Higashikata Co., Ltd.), Silwet l-77, L-7280, L-7001, L-7002, L-7200, L-7210, L-7220, L-7230, L7500, L-7600, L-7602, L-7604, L-7605, L-7622, ​​L-7657, L-8500, L- 8610 (manufactured by Modernite Powerman Materials Co., Ltd.), KP-341, KF-6001, KF-6002 (manufactured by Shin-Etsu Silicon Co., Ltd.), BYK307, BYK323, BYK330 (manufactured by Big Kemmy Co., Ltd.), etc. For example, as a polyether-modified silicone, the trade name L-7001 (manufactured by DOWSIL Co., Ltd.) can be used well.

[0180] In this invention, a film-forming composition containing the above-mentioned organic solvent sol and organic resin or polysiloxane can be obtained. The film-forming composition can be formed by removing the organic solvent from the organic solvent sol, thereby forming a film-forming composition containing hollow silica particles and organic resin.

[0181] When the above-mentioned film-forming composition is a thermosetting film-forming composition, a thermosetting agent can be added in the range of 0.01 to 50 phr or 0.01 to 10 phr relative to the resin containing functional groups such as epoxy groups or (meth)acryloyl groups. For example, the thermosetting agent can be contained in a ratio of 0.5 to 1.5 equivalents, preferably 0.8 to 1.2 equivalents, relative to functional groups such as epoxy groups or (meth)acryloyl groups. The equivalent of the thermosetting agent relative to the curable resin is expressed as the equivalent ratio of the thermosetting agent to the functional group.

[0182] Preferred thermosetting agents include phenolic resins, amine curing agents, polyamide resins, imidazoles, polythiols, acid anhydrides, thermal free radical generators, and thermal acid-generating agents. Free radical generator-based curing agents, acid anhydride-based curing agents, and amine-based curing agents are particularly preferred.

[0183] These thermosetting agents, even if solid, can be used by dissolving them in a solvent. However, due to the evaporation of the solvent, the density of the cured product decreases or fine pores are formed, which in turn leads to a decrease in strength and water resistance. Therefore, it is preferable that the curing agent itself is liquid at room temperature and pressure.

[0184] Examples of phenolic resins include phenolic varnish resin and cresol varnish resin.

[0185] Examples of amine curing agents include piperidine, N,N-dimethylpiperazine, triethylenediamine, 2,4,6-tris(dimethylaminomethyl)phenol, benzyldimethylamine, 2-(dimethylaminomethyl)phenol, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperazine, di(1-methyl-2-aminocyclohexyl)methane, montanane diamine, isoflurane diamine, diaminodicyclohexylmethane, 1,3-diaminomethylcyclohexane, phenylene dimethylamine, m-phenylenediamine, diaminodiphenylmethane, diaminodiphenyl sulfone, 3,3'-diethyl-4,4'-diaminodiphenylmethane, and diethyltoluene diamine. Among them, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperazine, di(1-methyl-2-aminocyclohexyl)methane, montanane diamine, isoflurane diamine, diaminodicyclohexylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, diethyltoluene diamine, etc., can be preferably used as liquids.

[0186] As a polyamide resin, it is generated by the condensation of dimer acid and polyamine, and is a polyamide amine with primary and secondary amines in its molecule.

[0187] Examples of imidazole derivatives include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, and epoxide imidazole adducts.

[0188] Polythiols are substances containing thiol groups at the ends of polypropylene glycol chains or polyethylene glycol chains, and are preferably liquid.

[0189] As an anhydride-based curing agent, anhydrides containing multiple carboxyl groups in one molecule are preferred. Examples of such anhydride-based curing agents include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol trimellitic acid ester, glycerol trimellitic acid ester, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylenetetrahydrophthalic anhydride, methylmethylenetetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, methylcyclohexene dicarboxylic anhydride, and chlorobridged anhydride.

[0190] Sulfonium salts and phosphonium salts can be used as thermal acid-producing agents, but sulfonium salts are preferred. Examples include the following compounds.

[0191]

[0192] Examples of R include alkyl groups having 1 to 12 carbon atoms and aryl groups having 6 to 20 carbon atoms, with alkyl groups having 1 to 12 carbon atoms being particularly preferred.

[0193] The preferred formulations are mixtures of methyltetrahydrophthalic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride (methylnadic anhydride), hydrogenated methylnadic anhydride, methylbutenyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, methylhexahydrophthalic anhydride, and hexahydrophthalic anhydride, which are liquid at room temperature and pressure. The viscosity of these liquid anhydrides is approximately 10 mPa·s to 1000 mPa·s when measured at 25°C.

[0194] Examples of thermal free radical initiators include, for instance, 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylpentanitrile), 4,4'-azobis(4-cyanopentanoic acid), dimethyl 2,2'-azobis(2-methylpropionic acid), 2,2'-azobis(2-methylpropanediol) dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, tert-butyl hydroperoxide, cumyl hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, benzoyl peroxide, etc. These are available from Tokyo Chemical Industry Co., Ltd.

[0195] In addition, curing aids may be appropriately used in conjunction with the cured product obtained above. Examples of curing aids include organophosphorus compounds such as triphenylphosphine and tributylphosphine, quaternary phosphonium salts such as ethyltriphenylphosphonium bromide and diethyl methyltriphenylphosphonium phosphate, quaternary ammonium salts such as 1,8-diazabicyclo(5,4,0)undecane-7-ene, 1,8-diazabicyclo(5,4,0)undecane-7-ene and octanoic acid salts, zinc octanoate, and tetrabutylammonium bromide. These curing aids may be contained in a ratio of 0.001 to 0.1 parts by mass relative to 1 part by mass of the curing agent.

[0196] The composition can be obtained by mixing resin, curing agent, and optional curing aid to obtain thermosetting varnish. Mixing can be carried out in a reaction vessel using stirring blades or a kneader.

[0197] Mixing is carried out by heating at a temperature of 60℃ to 100℃ for 0.5 to 1 hour.

[0198] The resulting curable film-forming composition is a thermosetting coating composition, for example, having a suitable viscosity for use as a liquid sealing material. The liquid thermosetting film-forming composition can be prepared to any viscosity, allowing for partial sealing at any location for use as a transparent sealing material for LEDs, etc., via casting, potting, dispenser methods, printing, etc. After directly mounting the liquid thermosetting composition onto LEDs, etc., using the above method, followed by drying and curing, a cured epoxy resin body is obtained.

[0199] A thermosetting film-forming composition (thermosetting coating composition) is applied to a substrate and heated at a temperature of 80–200°C to obtain a cured product.

[0200] When the above-mentioned film-forming composition is a photocurable resin composition, a photocuring agent (photoradical generator, photoacid generator) can be added in the range of 0.01 to 50 phr or 0.01 to 10 phr relative to the resin containing functional groups such as epoxy groups or (meth)acryloyl groups. For example, the photocuring agent (photoradical generator, photoacid generator) can be contained in a proportion of 0.5 to 1.5 equivalents, preferably 0.8 to 1.2 equivalents, relative to functional groups such as epoxy groups or (meth)acryloyl groups. The equivalent of the photocuring agent relative to the curable resin is expressed as the equivalent ratio of the photocuring agent to the functional group.

[0201] Photoradical generators are any substances that can generate free radicals directly or indirectly through light irradiation; there are no particular limitations.

[0202] Examples of photoradical generators and photoradical polymerization initiators include imidazole compounds, diazo compounds, diimidazole compounds, N-arylglycine compounds, organic azide compounds, titanocene compounds, aluminate compounds, organic peroxides, N-alkoxypyridinium salts, and thioxanthone compounds. Examples of azide compounds include p-azidobenzaldehyde, p-azidoacetophenone, p-azidobenzoic acid, p-azidophenylstyryl ketone, 4,4'-diazidochalcone, 4,4'-diazidodiphenyl sulfide, and 2,6-bis(4'-azidobenzyl)-4-methylcyclohexanone. Examples of diazo compounds include 1-diazo-4-N,N-dimethylaminochlorobenzene and 1-diazo-4-N,N-diethylaminophenyl fluoroborides. Examples of bisimidazole compounds include 2,2'-bis(o-chlorophenyl)-4,5,4',5'-tetra(3,4,5-trimethoxyphenyl)1,2'-bisimidazole and 2,2'-bis(o-chlorophenyl)4,5,4',5'-tetraphenyl-1,2'-bisimidazole. Examples of diacene compounds include dicyclopentadienyl-titanium dichloride, dicyclopentadienyl-titanium-bisphenyl, dicyclopentadienyl-titanium-bis(2,3,4,5,6-pentafluorophenyl), dicyclopentadienyl-titanium-bis(2,3,5,6-tetrafluorophenyl), dicyclopentadienyl-titanium-bis(2,4,6-trifluorophenyl), dicyclopentadienyl-titanium-bis(2,6-difluorophenyl), and dicyclopentadienyl-titanium-bis(2,6-difluorophenyl). Alkenyl-titanium-bis(2,4-difluorophenyl), bis(methylcyclopentadienyl)-titanium-bis(2,3,4,5,6-pentafluorophenyl), bis(methylcyclopentadienyl)-titanium-bis(2,3,5,6-tetrafluorophenyl), bis(methylcyclopentadienyl)-titanium-bis(2,6-difluorophenyl), and dicyclopentadienyl-titanium-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl), etc.

[0203] Other examples of photoradical generators include 1,3-bis(tert-butyldioxycarbonyl)benzophenone, 3,3',4,4'-tetra(tert-butyldioxycarbonyl)benzophenone, 3-phenyl-5-isoxazolone, 2-mercaptobenzimidazole, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone.

[0204] These photoradical polymerizing agents can be obtained, for example, by BASF under the trade name IrgacureTPO (containing 2,4,6-trimethylbenzoyl diphenylphosphine oxide) (formula (c1-1-1)), by IGM RESINS under the trade name Omnirad819 (containing bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide) (formula (c1-1-2)), and by IGM RESINS under the trade name Irgacure184 (containing 1-hydroxycyclohexylphenyl ketone) (formula (c1-1-3)).

[0205]

[0206] Photoacid generators are any substances that can produce acid directly or indirectly through light irradiation; there are no special limitations.

[0207] Specific examples of photoacid generators include triazine compounds, acetophenone derivatives, disulfone compounds, diazomethane compounds, sulfonic acid derivatives, iodonium salts, sulfonium salts, phosphonium salts, selenium salts, metallocene complexes, and iron aromatic hydrocarbon complexes.

[0208] Examples of onon salts used as photoacid-generating agents, such as iodonium salts, include diphenyliodonium chloride, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium methanesulfonate, diphenyliodonium toluenesulfonate, diphenyliodonium bromide, diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluoroarsenate, bis(p-tert-butylphenyl)iodonium hexafluorophosphate, bis(p-tert-butylphenyl)iodonium methanesulfonate, bis(p-tert-butylphenyl)iodonium toluenesulfonate, bis(p-tert-butylphenyl)iodonium trifluoromethanesulfonate, and bis(p-tert-butylphenyl)iodonium... Iodonium tetrafluoroborate, bis(p-tert-butylphenyl)iodonium chloride, bis(p-chlorophenyl)iodonium chloride, bis(p-chlorophenyl)iodonium tetrafluoroborate, and bis(4-tert-butylphenyl)iodonium hexafluorophosphate, etc., alkoxycarbonylalkoxy-trialkylaryl iodonium salts (e.g., 4-[(1-ethoxycarbonyl-ethoxy)phenyl]-(2,4,6-trimethylphenyl)iodonium hexafluorophosphate, etc.), bis(alkoxyaryl)iodonium salts (e.g., (4-methoxyphenyl)phenyliodonium hexafluoroantimonate, etc.).

[0209] Examples of sulfonium salts include triphenylsulfonium chloride, triphenylsulfonium bromide, tri(p-methoxyphenyl)sulfonium tetrafluoroborate, tri(p-methoxyphenyl)sulfonium hexafluorophosphonate, tri(p-ethoxyphenyl)sulfonium tetrafluoroborate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, etc.; (4-phenylthienyl)diphenylsulfonium hexafluoroantimonate, (4-phenylthienyl)diphenylsulfonium hexafluorophosphate, bis[4-(diphenylsulfonium)phenyl]sulfide-bis-hexafluoroantimonate, bis[4-(diphenylsulfonium)phenyl]sulfide-bis-hexafluorophosphate, (4-methoxyphenyl)diphenylsulfonium hexafluoroantimonate, etc.

[0210] Examples of phosphonium salts include triphenylphosphonium chloride, triphenylphosphonium bromide, tri(p-methoxyphenyl)phosphonium tetrafluoroborate, tri(p-methoxyphenyl)phosphonium hexafluorophosphonate, tri(p-ethoxyphenyl)phosphonium tetrafluoroborate, 4-chlorobenzyldiazoium hexafluorophosphate, and benzyltriphenylphosphonium hexafluoroantimonate.

[0211] Examples of selenium salts include triphenylselenohexafluorophosphate, and metallocene complexes include (η5 or η6-isopropylbenzene)(η5-cyclopentadienyl)iron(II)hexafluorophosphate.

[0212] In addition, the following compounds can also be used as photoacid generators.

[0213]

[0214]

[0215]

[0216]

[0217]

[0218]

[0219]

[0220] As photoacid-generating agents, sulfonium salt compounds and iodonium salt compounds are preferred. Examples of their anions include CF3SO3. - C4F9SO3 - C8F 17 SO3 - Camphor sulfonic acid anion, toluene sulfonic acid anion, BF4 - PF6 - AsF6 - and SbF6 - Etc. Especially preferred are anionic compounds such as phosphorus hexafluoride and antimony hexafluoride, which exhibit strong acidity.

[0221] Depending on the requirements, the film-forming composition of the present invention may contain conventional additives. Examples of such additives include, for instance, pigments, colorants, thickeners, sensitizers, defoamers, coatability modifiers, lubricants, stabilizers (antioxidants, heat stabilizers, light stabilizers, etc.), plasticizers, solubilizers, fillers, antistatic agents, etc. These additives may be used alone or in combination of two or more.

[0222] Examples of coating methods for the film-forming composition of the present invention include flow coating, spin coating, spray coating, screen printing, casting, bar coating, curtain coating, roller coating, gravure coating, immersion coating, and slot coating.

[0223] In this invention, a photocoating composition (a composition for film formation) can be coated onto a substrate and cured by light irradiation. Alternatively, heating can be performed before or after light irradiation.

[0224] The thickness of the coating can be selected from about 0.01μm to 10mm depending on the application of the cured material. For example, it can be about 0.05 to 10μm (especially 0.1 to 5μm) for photoresist, about 5μm to 5mm (especially 100μm to 1mm) for printed circuit boards, and about 0.1 to 100μm (especially 0.3 to 50μm) for optical films.

[0225] When a transparent coating is obtained, the visible light transmittance of the coating can be above 80% or 90%, typically 90-96%.

[0226] The light used for irradiation or exposure when using photoacid-generating agents can be, for example, gamma rays, X-rays, ultraviolet light, or visible light, usually visible light or ultraviolet light, especially ultraviolet light. The wavelength of the light is, for example, 150–800 nm, preferably 150–600 nm, and more preferably around 150–400 nm. The amount of irradiated light varies depending on the thickness of the coating, for example, it can be 2–20000 mJ / cm². 2 Preferably, it is 5–5000 mJ / cm 2 The light source can be selected based on the type of light being exposed. For example, under ultraviolet light, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, deuterium lamps, halogen lamps, lasers (helium-cadmium lasers, excimer lasers, etc.) can be used. The composition undergoes a curing reaction under such light irradiation.

[0227] When using a thermally generated acid agent or a photogenerated acid agent, the coating film is heated as needed after light irradiation, for example, at 60–350°C, preferably at 100–300°C. The heating time can be selected from a range of more than 3 seconds (e.g., 3 seconds to about 5 hours), for example, 5 seconds to 2 hours, preferably about 20 seconds to 30 minutes, and usually about 1 minute to 3 hours (e.g., 5 minutes to 2.5 hours).

[0228] Furthermore, in cases where patterns or images are to be formed (e.g., in the manufacture of printed wiring substrates), the coating film formed on the substrate can be pattern-exposed. This pattern exposure can be performed by laser scanning or by irradiation through a photomask. By developing (or dissolving) the unexposed areas (unexposed portions) generated by such pattern exposure with a developer, patterns or images can be formed.

[0229] As a developer, an alkaline aqueous solution or an organic solvent can be used.

[0230] Examples of alkaline aqueous solutions include aqueous solutions of alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, potassium carbonate, and sodium carbonate; aqueous solutions of quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline; and aqueous solutions of amines such as ethanolamine, propylamine, and ethylenediamine.

[0231] The aforementioned alkaline developer is generally an aqueous solution of 10% by mass or less, preferably an aqueous solution of 0.1% to 3.0% by mass. Furthermore, alcohols or surfactants can also be added to the aforementioned developer, preferably in amounts of 0.05 to 10 parts by mass relative to 100 parts by mass of the developer.

[0232] An aqueous solution of tetramethylammonium hydroxide at a concentration of 0.1–2.38% by mass can be used.

[0233] In addition, common organic solvents can be used as the developing solution, such as acetone, acetonitrile, toluene, dimethylformamide, methanol, ethanol, isopropanol, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol butyl ether acetate, ethyl lactate, cyclohexanone, etc., and one or a mixture of two or more of them can be used. Propylene glycol methyl ether, propylene glycol methyl ether acetate, ethyl lactate, etc. are particularly preferred.

[0234] In this invention, to improve the adhesion to the substrate after development, an adhesion promoter can be added. Examples of such adhesion promoters include chlorosilanes such as trimethylchlorosilane, dimethylvinylchlorosilane, methyldiphenylchlorosilane, and chloromethyldimethylchlorosilane; alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylvinylethoxysilane, diphenyldimethoxysilane, and phenyltriethoxysilane; silazanes such as hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, and trimethylsilylimidazolium; and vinyltrichlorosilanes. The mixture includes silanes such as 3-chloropropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-(N-piperidinyl)propyltrimethoxysilane; heterocyclic compounds such as benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, urazole, thiouracil, mercaptoimidazole, and mercaptopyrimidine; and urea or thiourea compounds such as 1,1-dimethylurea and 1,3-dimethylurea. One or more of the above-mentioned adhesion promoters may be used. The amount of these adhesion promoters added is typically less than 18% by mass in the solid content, preferably 0.0008 to 9% by mass, and more preferably 0.04 to 9% by mass.

[0235] In this invention, a sensitizer may also be included. Examples of usable sensitizers include anthracene, phenothiazine, perylene, thioxanthone, and benzophenone-thioxanthone. Furthermore, examples of sensitizing pigments include thiopyrylium salt pigments, anthocyanin pigments, quinoline pigments, styrylylquinoline pigments, ketocoumarin pigments, thioxanthone pigments, xanthanthone pigments, 1,5-bis(5-oxo-3-propylisoazol-4-yl)pentamethoxyl pigments, anthocyanin pigments, rhodamine pigments, and pyranonium salt pigments. Anthracene-based sensitizers are particularly preferred. When used in conjunction with a cationic curing catalyst (a radiosensitive cationic polymerization initiator), the sensitivity is dramatically increased, and they also possess free radical polymerization initiation capabilities. In hybrid systems combining the cationic curing system and the free radical curing system of this invention, the type of catalyst can be simplified. Specific anthracene compounds such as dibutoxyanthracene and dipropoxyanthraquinone are effective. The sensitizer is added in a proportion of 0.01 to 20% by mass, preferably 0.01 to 10% by mass, of the solid component.

[0236] The compositions of the present invention can be photocured or thermally cured using photoradicals, thermalradicals, photoacid generators, or thermal acid generators. When using photoacid generators or thermal acid generators, conventional epoxy curing agents (e.g., amines or anhydrides) are not used, or if used, their content is very low, thus improving the storage stability of the compositions.

[0237] The above composition was found to be suitable for photocationic polymerization. Its curing speed is higher than that of conventional liquid epoxy compounds (e.g., alicyclic epoxy compounds with an epoxy cyclohexyl ring). Due to the fast curing speed, the amount of acid-generating agent added can be reduced, or a weak acid-based acid-generating agent can be used. Reducing the amount of acid-generating agent is important for preventing metal corrosion caused by residual acidic active species after UV irradiation. Due to the fast curing speed, thick film curing is possible.

[0238] Curing via UV irradiation can be applied to heat-sensitive materials (equipment).

[0239] The thermosetting and photocurable materials using the film-forming compositions of the present invention possess characteristics such as low dielectric constant, low dielectric loss tangent, rapid curing, high transparency, and low curing shrinkage. They can be used for coating or bonding electronic components, optical components (anti-reflective films), and precision mechanical components. For example, they can be used for bonding optical elements such as lenses for mobile phones or cameras, light-emitting diodes (LEDs), semiconductor lasers (LDs), liquid crystal panels, biochips, camera lenses or prisms, magnetic components of hard drives for personal computers, pickups (the part that picks up light information reflected from the disc) in CD and DVD players, cones and coils in loudspeakers, magnets in electric motors, circuit boards, electronic components, and internal components of automobile engines.

[0240] As a hard coating material used for surface protection of automobile bodies, lamps or electrical products, building materials, plastics, etc., it can be applied to automobile and motorcycle bodies, headlight lenses or reflectors, plastic lenses for eyeglasses, mobile phones, game consoles, optical films, ID cards, etc.

[0241] As ink materials for printing on metals such as aluminum and plastics, examples include inks used for cards such as credit cards and membership cards, inks used for printing on switches and keyboards of electrical products or OA equipment, and inkjet printer inks used for CDs, DVDs, etc.

[0242] Examples include technologies that combine with 3D CAD to cure resin and form complex three-dimensional objects, light modeling suitable for industrial product model making, and coating, bonding, optical waveguides, and thick film resists suitable for optical fibers.

[0243] Furthermore, the coating-forming composition of the present invention can be used as an insulating resin for electronic materials such as anti-reflective films, semiconductor sealing materials, adhesives for electronic materials, printed wiring substrate materials, interlayer insulating film materials, buffer coating agents for semiconductors, enamel insulating materials, and sealing materials for power modules, or as an insulating resin used in high-voltage equipment such as generator coils, transformer coils, and gas-insulated switching devices.

[0244] The hollow silica sol of the present invention can be manufactured by including the following steps (I) to (II).

[0245] (I) Process: The process of preparing hollow silica sol.

[0246] (II) Process: In the hollow silica sol of process (I), the molar ratio of monovalent alkali metal ions to M2O (where M represents monovalent alkali metal atoms) relative to SiO2 of the hollow silica particles is 7.12 × 10⁻⁶. -6 ~285×10 -6 The process involves adjusting the proportions to obtain hollow silica sol.

[0247] In step (II) above, sodium ions are preferred as monovalent alkali metal ions.

[0248] In step (II) above, the sodium ion content can be adjusted by contacting the hollow silica sol obtained in step (I) with the cation exchange resin or by adding a sodium source. In step (II) above, the sodium source added is sodium hydroxide, preferably an aqueous solution of sodium hydroxide.

[0249] The dispersion medium for steps (I) and (II) may be water, alcohols, ketones, ethers, amides, ureas, or esters having 1 to 10 carbon atoms. Examples of such dispersion media include the solvents described above.

[0250] In this invention, at least one step selected from (i) to (iv) below may be added to step (I), step (II) above or both of these steps.

[0251] (i): Adding amines to hollow silica sol

[0252] (ii): Sodium aluminate is added as an aluminum source and heated to form aluminosilicate sites in hollow silica particles.

[0253] (iii): Replace the dispersion medium with another dispersion medium.

[0254] (iv): Hollow silica particles are coated with at least one silane compound selected from formula (1) and formula (2).

[0255] Furthermore, the present invention also provides a method for stabilizing a hollow silica sol containing hollow silica particles with spaces within the shell. In this method, monovalent alkali metal ions are added to the hollow silica sol having a dynamic light scattering particle size value that is increased compared to the dynamic light scattering particle size at the time of manufacturing, such that the molar ratio of the monovalent alkali metal ions (converted to M₂O, where M represents a monovalent alkali metal atom) to the SiO₂ of the hollow silica particles in the hollow silica sol is 7.12 × 10⁻⁶. -6 ~285×10 -6 The increased proportion leads to a decrease in the particle size value in the dynamic light scattering method. In the above stabilization method, sodium ions can be used as monovalent alkali metal ions.

[0256] Regarding the hollow silica sol in step (ii), it is a process in which 0.0001 to 0.5 g of aluminum compound is added to an aqueous sol for every 1 g of hollow silica particles, and the mixture is heated at 40 to 260°C for 0.1 to 24 hours. The amount of aluminum compound added in step (ii) relative to every 1 g of hollow silica particles can be in the range of 0.0001 to 0.5 g, 0.001 to 0.1 g, or 0.001 to 0.05 g. Furthermore, the heating temperature in step (ii) is 40 to 260°C, 50 to 260°C, or 60 to 240°C, but in the case of non-hydrothermal treatment, it can be used at temperatures above 40°C and below 100°C, or above 50°C and below 100°C, or above 60°C and below 100°C; in the case of hydrothermal treatment, it can be carried out at 100 to 260°C or 150 to 240°C. (ii) The heating time in the process can be in the range of 0.1 to 48 hours, or 0.1 to 24 hours, or 0.1 to 10 hours, or 1 to 10 hours.

[0257] (I) The hollow silica particles used in the process have a silica shell with a space inside the shell. Hollow silica is obtained by forming a shell, primarily composed of silica, on the surface of a portion corresponding to a core, in an aqueous dispersion medium, and then removing the portion corresponding to the core. The template can be made using organic materials (e.g., hydrophilic organic resin particles such as polyethylene glycol, polystyrene, and polyester) or inorganic materials (e.g., hydrophilic inorganic compound particles such as calcium carbonate and sodium aluminate).

[0258] The hollow silica aqueous sol used as the raw material in process (I) can be a non-hydrothermal treated hollow silica aqueous sol that has been heated in an aqueous medium to a temperature below 100°C, for example, above 20°C and below 100°C, or above 40°C and below 100°C, or above 50°C and below 100°C.

[0259] In addition, the hollow silica aqueous sol used in process (I) can be a hydrothermally treated hollow silica aqueous sol that has been heated in an aqueous medium at a temperature of 100°C to 240°C or 110°C to 240°C.

[0260] The hollow silica sol used as a raw material in this invention can be a non-hydrothermal-treated aqueous hollow silica sol, a hydrothermal-treated aqueous hollow silica sol, or a mixture thereof. Aluminosilicate sites are formed on the outer shell of the hollow silica particles. However, since these aluminosilicate sites sometimes retain alkali metals, the hollow silica sol used as a raw material can be selected based on the following conditions: the aluminum atoms on the surface of the hollow silica particles, measured by leaching, are converted to Al2O3 and bonded relative to the mass of SiO2 in the hollow silica particles at a ratio of 100 to 20,000 ppm / SiO2.

[0261] (ii) In the process, an aluminum compound is added to the aqueous hollow silica sol. The aluminum compound may be added to the aqueous hollow silica sol in solid or aqueous solution form.

[0262] (ii) The aluminum compound used in the process is at least one aluminum compound selected from aluminates, alkoxyaluminum, and their hydrolysates, and can be used as an aqueous solution containing them. Examples of aluminates include sodium aluminate, potassium aluminate, calcium aluminate, magnesium aluminate, ammonium aluminate, and aluminate amine salts. Examples of alkoxyaluminum include aluminum isopropoxy and aluminum butoxy. Aluminates are particularly preferred.

[0263] These aluminum compounds are added in aqueous solution form to the hollow silica aqueous sol obtained in step (I), and the aluminum compounds are used at a concentration in the aqueous solution ranging from 0.01% to 20% by mass, or 0.1% to 10% by mass, or 0.5% to 5% by mass. The addition can be carried out while the hollow silica aqueous sol obtained in step (I) is being stirred. The addition can be completed before heating, or it can be added during the entire heating time.

[0264] The amount of aluminum compound incorporated into the hollow silica particles depends on the processing temperature in step (ii), which requires heating within the aforementioned temperature range.

[0265] (i) The process may also include a step of adding an amine. The amine may be added as described above and may be included in the hollow silica sol within the range described above.

[0266] The above-mentioned step (ii) may include the following steps: a step of adding the above-mentioned aluminum compound, or at least one additive composed of the above-mentioned aluminum compound, an amine, and a neutral salt, followed by heating treatment, and then contacting it with a cation exchange resin; a step of adding an acid; or a combination thereof. The cation exchange resin is an H-type strong acid cation exchange resin, and may also subsequently be contacted with an anion exchange resin. The acid may be an inorganic acid such as sulfuric acid, nitric acid, hydrochloric acid, or phosphoric acid, or an organic acid such as citric acid, acetic acid, malic acid, lactic acid, succinic acid, tartaric acid, butyric acid, fumaric acid, propionic acid, or formic acid.

[0267] In this invention, step (ii) can be performed as follows: The aluminum compound (e.g., sodium aluminate) is added, and after heat treatment at 100–240°C for 0.1–48 hours, an acid (e.g., sulfuric acid, nitric acid, hydrochloric acid) is added to bring it into contact with the cation exchange resin. The addition of the acid is a leaching operation that dissolves undoped aluminum components and metallic impurities contained in the particles into the liquid through heat treatment. This is an operation to remove these metallic components using the cation exchange resin. After further heating and aging at 40–100°C for 0.1–48 hours, the contact with the cation exchange resin can be performed again.

[0268] As step (iii), the following steps may be further included:

[0269] The process of replacing the aqueous medium solvent of hollow silica aqueous sol with an alcohol, ketone, ether or ester having 1 to 10 carbon atoms.

[0270] The process involves adding at least one silane compound selected from formulas (1) and (2) and heating (iv).

[0271] Regarding steps (iii) and (iv) above, after step (ii) is completed, in step (iii) the solvent is replaced with an alcohol having 1 to 10 carbon atoms, and in step (iv) at least one silane compound selected from formulas (1) and (2) above is added, and after heating, the solvent is further replaced with a ketone, ether, amide, urea or ester having 1 to 10 carbon atoms.

[0272] By using the above-described method for manufacturing hollow silica sol, the surface charge of the hollow silica particles contained in the sol can be adjusted.

[0273] Example

[0274] The following examples and comparative examples illustrate the present invention in more detail, but the present invention is not limited to the following examples.

[0275] The hollow silica sols used in the examples and comparative examples are as follows.

[0276] Hollow silica sol

[0277] Aqueous dispersed hollow silica sol (manufactured by Ningbo Dilato, trade name: HKT-A20-40D), an aqueous hollow silica sol, is a sol obtained after heating in an aqueous medium at temperatures ranging from 100°C to 240°C. The pH is 9.3, the particle size measured by dynamic light scattering is 55 nm, the average primary particle size observed by TEM is 43 nm, and the TEM-converted specific surface area (D) is 63 m². 2 / g, specific surface area ratio (C / D ratio) is 2.4, silica concentration is 20% by mass, Na content: 14ppm / SiO2, that is, the amount of Na2O contained, expressed as the molar ratio of Na2O to SiO2, is 6.64×10 -6 (molar / SiO2)

[0278] [Basic compounds]

[0279] Sodium hydroxide aqueous solution (Kanto Chemical Co., Ltd., trade name: 4 mol / L sodium hydroxide solution)

[0280] Diethanolamine (Tokyo Chemical Industry Co., Ltd., trade name: Diethanolamine)

[0281] The physical properties of water-dispersed hollow silica sol, dispersions of silica particles prepared in the examples and comparative examples, and hollow silica sol and dispersions in the manufacturing process of the dispersions were determined and evaluated according to the following methods.

[0282] [Determination of silicon dioxide (SiO2) concentration]

[0283] The silica concentration in water-dispersed hollow silica sol, methanol-dispersed hollow silica sol, hollow silica sol in the manufacturing process of methanol-dispersed hollow silica sol, and dispersions of surface-modified silica particles is calculated by taking these hollow silica sols or dispersions into a crucible, removing the solvent by heating, calcining at 1000°C, and measuring the remaining components after calcination.

[0284] [pH Measurement]

[0285] The pH was measured at 25°C using a pH meter (manufactured by Toa Discrete Co., Ltd., trade name: MM-43X).

[0286] For organic solvents such as methanol sol and propylene glycol monomethyl ether sol that are miscible with water, a solution prepared by mixing pure water and the sol in a 1:1 mass ratio is used for determination. For organic solvent sols such as methyl ethyl ketone sol that have low solubility in water, a solution prepared by mixing pure water, methanol, and the organic solvent sol in a 1:1:1 mass ratio is used for determination.

[0287] [Moisture content determination]

[0288] The water content of the organic solvent-dispersed sol was determined by Karl Fischer titration.

[0289] [Analytical methods for Na content]

[0290] 0.2 g of powder obtained by drying hollow silica sol was treated with 20 mL of 48% hydrofluoric acid solution to remove silica components. The residue was dissolved in 20 mL of 0.1 mol / L (N / 10) nitric acid aqueous solution. The Na content in the resulting aqueous solution was determined using an ICP-OES analyzer (trade name CIROS120 E0P (Ligaku Corporation)). The Na content in the whole silica particles was then calculated by dividing the Na content by the Si content.

[0291] Determination of particle size using dynamic light scattering (DLS) method

[0292] The particle size was determined using a dynamic light scattering particle size measuring device (manufactured by Spectris Corporation, trade name: Zetaceranano). The Z-mean particle size was used as the dynamic light scattering particle size.

[0293] Specific surface area (C)(S) of nitrogen adsorption method (BET method) N 2) Determination

[0294] Specific surface area (S) of silica particles in water-dispersed hollow silica sol by nitrogen adsorption method N2 The specific surface area was determined by removing water-soluble cations from the water-dispersed hollow silica sol using a cation exchange resin (manufactured by Dow Kemica Co., Ltd., trade name: Unbar Light IR-120B), drying the hollow silica sol at 290°C, and using it as a test sample. The specific surface area was then measured using a Monosorb apparatus (manufactured by Catechol Ments Japan Co., Ltd.) based on nitrogen adsorption.

[0295] [Average primary particle size measured by TEM (transmission electron microscopy)]

[0296] The silica particles in the hollow silica sol were photographed using a transmission electron microscope (JEM-F200, manufactured by Nippon Electron Co., Ltd.). Approximately 300 randomly selected particles were binarized using an automatic image processing and analysis device (LUZEX'AP, manufactured by Nileco Co., Ltd.). The projected area was measured, converted into a circle, and the diameter was calculated as the average first particle diameter (HEYWOOD diameter).

[0297] [TEM converted specific surface area (D)]

[0298] Assuming the true density is 2.2 g / cm³ 3For spherical particles, the average first particle size obtained by [TEM (transmission electron microscopy) measurement of average first particle size] is used to calculate (TEM-converted specific surface area (D) = 2720 / average first particle size).

[0299] [Determination of the amount of aluminum (A) bonded to the surface of hollow silica particles / Leaching method]

[0300] The cationic components in the hollow silica sol were removed using H-type cation exchange resin. The dried product, after being pulverized in a mortar and pestle and subjected to heat treatment to remove the solvent, was then treated at 250°C for 2 hours. 0.2 g of the obtained powder was added to a 50 mL PP sampling bottle containing 20 mL of 0.1 mol / L (N / 10) nitric acid aqueous solution and vigorously shaken by hand to mix. Next, it was ultrasonically treated for 10 minutes using an ASU Cleaner ASU-10M (ASU-10M) to ensure thorough mixing of the powder and the nitric acid aqueous solution. The mixture was then placed in a 50°C constant temperature bath and maintained for 17 hours. Then, the internal solution was cooled to room temperature and placed in a centrifugal ultrafiltration filter (Amicon Ultra-15, fractionated molecular weight 10,000). The amount of aluminum in the filtrate obtained by centrifugation was determined using an ICP emission spectrometer. The amount of aluminum bound to the surface of the hollow silica particles was converted into Al2O3, and the ratio of its mass to the mass of SiO2 in the hollow silica was calculated (Al2O3 (ppm) / SiO2).

[0301] [Determination / Dissolution Method of Aluminum (B) Presence in Hollow Silica Particles]

[0302] 0.2 g of precisely weighed powder obtained from the drying of hollow silica sol was treated with 20 mL of 48% hydrofluoric acid solution to remove silica. The residue was dissolved in 20 mL of 0.1 mol / L (N / 10) nitric acid aqueous solution. The aluminum content in the resulting aqueous solution was determined using an ICP emission spectrometer. The aluminum content in the hollow silica particles was converted to Al2O3, and the ratio of Al2O3 (ppm) to SiO2 mass of the hollow silica was calculated (Al2O3 / SiO2).

[0303] [Determination of the surface charge of hollow silica particles]

[0304] Hollow silica sol was added to 10 mL of methanol to dilute it to a silica concentration of 0.5% by mass, which was then used as the sample for analysis. Using a particle charge meter (manufactured by Factoro Corporation, trade name PCD-06), a 0.001 mol / L (N / 1000) diallyl dimethylammonium chloride solution (manufactured by Factoro Corporation) was used as the cation standard titrant to determine the titration value until the flow potential of the sample reached zero. The resulting titration value was divided by the mass of silica contained in the sample to convert it into the surface charge (μeq / g-SiO2) corresponding to 1 g of hollow silica particles.

[0305] [Example 1]

[0306] (a) Procedure: 150g of water-dispersed hollow silica sol (manufactured by Ningbo Dilato, trade name: HKT-A20-40D) was placed into a 500cc bowl-shaped flask. While stirring with a magnetic stirrer, the sodium content in the water-dispersed hollow silica sol was adjusted to 384ppm / SiO2 (i.e., the amount of Na2O contained, calculated as a molar ratio of Na2O to SiO2 of 182.16 × 10⁻⁶). -6 Sodium hydroxide aqueous solution was added dropwise in a manner corresponding to the molar ratio of SiO2. The resulting silica sol had a pH of 10.1, a particle size of 55 nm as determined by dynamic light scattering, an average primary particle size of 43 nm as observed by TEM, a silica concentration of 20% by mass, and a specific surface area (C) of 150 m² / m³ obtained by the BET method. 2 / g, the TEM equivalent specific surface area (D) is 63m². 2 The specific surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the mass of SiO2 in the hollow silica particles. The proportion of aluminum (B) present in the entire particle, converted to Al2O3, to the mass of SiO2 in the hollow silica particles is 0.5 ppm, and the (A / B ratio) is 0.20. The sodium content in the water-dispersed hollow silica sol is 384 ppm / SiO2, which means the amount of Na2O contained is 182 × 10⁻⁶ m / g, calculated as the molar ratio of Na2O to SiO2. -6 moles / SiO2.

[0307] (b) Process: Then, 56g of methanol was added to 150g of the obtained water-dispersed hollow silica sol. Using a rotary evaporator, water was removed by distillation while supplying methanol under heating and reduced pressure (bath temperature: 120°C, pressure reduction: 580 Torr), thereby obtaining a methanol dispersion of hollow silica (methanol-dispersed hollow silica sol). The methanol replacement was completed when the water content of the methanol-dispersed hollow silica sol was less than 2.0% by mass, yielding 150g of methanol-dispersed hollow silica sol.

[0308] The resulting methanol-dispersed hollow silica sol had a silica concentration of 21% by mass, a water content of 1.3% by mass, a particle size of 66 nm as determined by dynamic light scattering, a pH of 9.0, and a specific surface area (C) of 150 m² as determined by the BET method. 2 / g, TEM equivalent specific surface area (D) is 63m² 2 The surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the SiO2 mass of the hollow silica particles. The amount of aluminum (B) present in the entire particle, converted to Al2O3, is 0.5 ppm relative to the SiO2 mass of the hollow silica particles. The A / B ratio is 0.20. The sodium content in the methanol-dispersed hollow silica sol is 384 ppm / SiO2, which means the amount of Na2O contained is 182 × 10⁻⁶ molar ratio of Na2O to SiO2. -6 moles / SiO2.

[0309] The obtained methanol-dispersed hollow silica sol was sealed in a 30cc glass bottle and then stored in an explosion-proof thermostatic bath (manufactured by Especk Co., Ltd., trade name: thermostatic bath with safety valve) at 50°C for 48 hours. The dynamic light scattering particle size before and after storage at 50°C was compared to confirm the stability of the methanol-dispersed hollow silica sol. Regarding the dynamic light scattering particle size before being placed at 50°C, if the value of the dynamic light scattering particle size after 48 hours of storage at 50°C was within 2.0 times that before storage, it was evaluated as "stable"; if it exceeded 2.0 times, it was evaluated as "unstable". The stability of the methanol-dispersed hollow silica sol obtained in Example 1 is shown in Table 1.

[0310] [Example 2]

[0311] (a) Procedure: 150g of water-dispersed hollow silica sol (manufactured by Ningbo Dilato, trade name: HKT-A20-40D) was placed into a 500cc bowl-shaped flask. While stirring with a magnetic stirrer, the sodium content in the water-dispersed hollow silica sol was adjusted to 384ppm / SiO2 (i.e., the amount of Na2O contained, calculated as a molar ratio of Na2O to SiO2 of 182.16 × 10⁻⁶). -6 Sodium hydroxide aqueous solution was added dropwise in a manner corresponding to the molar ratio of SiO2. Then, while stirring with a magnetic stirrer, 0.16 g of diethanolamine was added dropwise. The resulting silica sol had a pH of 10.2, a particle size of 55 nm as determined by dynamic light scattering, an average primary particle size of 43 nm as observed by TEM, a silica concentration of 20% by mass, and a specific surface area (C) of 150 m² / g as determined by the BET method. 2 / g, the TEM equivalent specific surface area (D) is 63m². 2The specific surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the mass of SiO2 in the hollow silica particles. The proportion of aluminum (B) present in the entire particle, converted to Al2O3, to the mass of SiO2 in the hollow silica particles is 0.5 ppm, and the (A / B ratio) is 0.20. The sodium content in the water-dispersed hollow silica sol is 384 ppm / SiO2, which is the amount of Na2O contained. The molar ratio of Na2O to SiO2 is 182 × 10⁻⁶. -6 moles / SiO2.

[0312] (b) Process: Then, 56g of methanol was added to 150g of the obtained water-dispersed hollow silica sol. Using a rotary evaporator, water was removed by distillation while supplying methanol under heating and reduced pressure (bath temperature: 120°C, pressure reduction: 580 Torr) to obtain a methanol dispersion of hollow silica (methanol-dispersed hollow silica sol). The methanol replacement was stopped when the water content of the methanol-dispersed hollow silica sol was below 2.0% by mass, yielding 150g of methanol-dispersed hollow silica sol.

[0313] The obtained methanol-dispersed hollow silica sol had a silica concentration of 21% by mass, a water content of 0.4% by mass, a particle size of 66 nm as determined by dynamic light scattering, and a specific surface area (C) of 150 m² as determined by BET. 2 / g, TEM equivalent specific surface area (D) is 63m² 2 The surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the mass of SiO2 in the hollow silica particles. The amount of aluminum (B) present in the entire particle, converted to Al2O3, is 0.5 ppm relative to the mass of SiO2 in the hollow silica particles. The A / B ratio is 0.20. The sodium content in the methanol-dispersed hollow silica sol is 384 ppm / SiO2, meaning the amount of Na2O contained, expressed as a molar ratio of Na2O to SiO2, is 182 × 10⁻⁶. -6 moles / SiO2.

[0314] The same stability test as in Example 1 was conducted, and the results are shown in Table 1.

[0315] [Example 3]

[0316] (a) Procedure: 150g of water-dispersed hollow silica sol (manufactured by Ningbo Dilato, trade name: HKT-A20-40D) was placed into a 500cc bowl-shaped flask. While stirring with a magnetic stirrer, the sodium content in the water-dispersed hollow silica sol was adjusted to 384ppm / SiO2 (i.e., the amount of Na2O contained, calculated as a molar ratio of Na2O to SiO2 of 182.16 × 10⁻⁶).-6 Sodium hydroxide aqueous solution was added dropwise in a manner corresponding to the molar ratio of SiO2. Then, while stirring with a magnetic stirrer, 0.16 g of diethanolamine was added dropwise. The resulting silica sol had a pH of 10.2, a particle size of 55 nm as determined by dynamic light scattering, an average primary particle size of 43 nm as observed by TEM, a silica concentration of 20% by mass, and a specific surface area (C) of 150 m² / g as determined by the BET method. 2 / g, the TEM equivalent specific surface area (D) is 63m². 2 The specific surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the mass of SiO2 in the hollow silica particles. The amount of aluminum (B) present in the entire particle, converted to Al2O3, is 0.5 ppm relative to the mass of SiO2 in the hollow silica particles, with an (A / B ratio) of 0.20. The sodium content in the water-dispersed hollow silica sol is 384 ppm / SiO2, meaning the amount of Na2O contained, expressed as a molar ratio of Na2O to SiO2, is 182 × 10⁻⁶. -6 moles / SiO2.

[0317] (b) Process: Then, 56g of methanol was added to 150g of the obtained water-dispersed hollow silica sol. Using a rotary evaporator, water was removed by distillation while supplying methanol under heating and reduced pressure (bath temperature: 120°C, pressure reduction: 580 Torr) to obtain a methanol dispersion of hollow silica (methanol-dispersed hollow silica sol). The methanol replacement was stopped when the water content of the methanol-dispersed hollow silica sol was below 2.0% by mass, yielding 150g of methanol-dispersed hollow silica sol.

[0318] 30g of methanol-dispersed hollow silica sol was added to a 50cc round-bottom flask, and 0.33g of pure water was added while stirring with a magnetic stirrer. The resulting methanol-dispersed hollow silica sol had a silica concentration of 21% by mass, a water content of 1.5% by mass, a particle size of 66nm by dynamic light scattering, and a specific surface area (C) of 150m² by BET method. 2 / g, TEM equivalent specific surface area (D) is 63m² 2 The surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the mass of SiO2 in the hollow silica particles. The amount of aluminum (B) present in the entire particle, converted to Al2O3, is 0.5 ppm relative to the mass of SiO2 in the hollow silica particles. The A / B ratio is 0.20. The sodium content in the methanol-dispersed hollow silica sol is 384 ppm / SiO2, meaning the amount of Na2O contained, expressed as a molar ratio of Na2O to SiO2, is 182 × 10⁻⁶. -6 moles / SiO2.

[0319] [Example 4]

[0320] (a) Procedure: 150g of water-dispersed hollow silica sol (manufactured by Ningbo Dilato, trade name: HKT-A20-40D) was placed into a 500cc round-bottom flask. While stirring with a magnetic stirrer, sodium hydroxide aqueous solution was added dropwise to make the sodium content in the water-dispersed hollow silica sol 192ppm / SiO2 (i.e., the amount of Na2O contained, calculated as the molar ratio of Na2O to SiO2, is 91.08×10⁻⁶). -6 (molar / SiO2). Then, while stirring with a magnetic stirrer, 0.16 g of diethanolamine was added dropwise. The resulting silica sol had a pH of 9.8, a particle size of 55 nm according to dynamic light scattering, an average primary particle size of 43 nm observed by TEM, a silica concentration of 20% by mass, and a specific surface area (C) of 150 m² / g obtained by the BET method. 2 / g, the TEM equivalent specific surface area (D) is 63m². 2 The specific surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the mass of SiO2 in the hollow silica particles. The amount of aluminum (B) present in the entire particle, converted to Al2O3, is 0.5 ppm relative to the mass of SiO2 in the hollow silica particles, with an (A / B ratio) of 0.20. The sodium content in the water-dispersed hollow silica sol is 192 ppm / SiO2, which is the amount of Na2O contained, calculated as the molar ratio of Na2O to SiO2 as 91 × 10⁻⁶. -6 moles / SiO2.

[0321] (b) Process: Then, 56g of methanol was added to 150g of the obtained water-dispersed hollow silica sol. Using a rotary evaporator, water was removed by distillation while supplying methanol under heating and reduced pressure (bath temperature: 120°C, pressure reduction: 580 Torr) to obtain a methanol dispersion of hollow silica (methanol-dispersed hollow silica sol). The methanol replacement was stopped when the water content of the methanol-dispersed hollow silica sol was below 2.0% by mass, yielding 150g of methanol-dispersed hollow silica sol.

[0322] The obtained methanol-dispersed hollow silica sol had a silica concentration of 21% by mass, a water content of 0.6% by mass, a particle size of 66 nm as determined by dynamic light scattering, and a specific surface area (C) of 150 m² as determined by BET. 2 / g, TEM equivalent specific surface area (D) is 63m² 2The surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the mass of SiO2 in the hollow silica particles. The amount of aluminum (B) present in the entire particle, converted to Al2O3, is 0.5 ppm relative to the mass of SiO2 in the hollow silica particles. The A / B ratio is 0.20. The sodium content in the methanol-dispersed hollow silica sol is 192 ppm / SiO2, meaning the amount of Na2O contained, expressed as a molar ratio of Na2O to SiO2, is 182 × 10⁻⁶. -6 moles / SiO2.

[0323] The same stability test as in Example 1 was conducted, and the results are shown in Table 1.

[0324] [Example 5]

[0325] (a) Procedure: 150g of water-dispersed hollow silica sol (manufactured by Ningbo Dilato, trade name: HKT-A20-40D) was placed into a 500cc round-bottom flask. While stirring with a magnetic stirrer, sodium hydroxide aqueous solution was added dropwise to make the sodium content in the water-dispersed hollow silica sol 192ppm / SiO2 (i.e., the amount of Na2O contained, calculated as the molar ratio of Na2O to SiO2, is 91.08×10⁻⁶). -6 (mol / SiO2). Then, while stirring with a magnetic stirrer, 0.16 g of diethanolamine was added dropwise. The resulting silica sol had a pH of 9.8, a particle size of 55 nm by dynamic light scattering, an average primary particle size of 43 nm observed by TEM, a silica concentration of 20% by mass, and a specific surface area (C) of 150 m² / g obtained by the BET method. 2 / g, the TEM equivalent specific surface area (D) is 63m². 2 The specific surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the mass of SiO2 in the hollow silica particles. The amount of aluminum (B) present in the entire particle, converted to Al2O3, is 0.5 ppm relative to the mass of SiO2 in the hollow silica particles, with an (A / B ratio) of 0.20. The sodium content in the water-dispersed hollow silica sol is 192 ppm / SiO2, which is the amount of Na2O contained, calculated as the molar ratio of Na2O to SiO2 as 91 × 10⁻⁶. -6 moles / SiO2.

[0326] (b) Process: Then, 56g of methanol was added to 150g of the obtained water-dispersed hollow silica sol. Using a rotary evaporator, water was removed by distillation while supplying methanol under heating and reduced pressure (bath temperature: 120°C, pressure reduction: 580 Torr) to obtain a methanol dispersion of hollow silica (methanol-dispersed hollow silica sol). The methanol replacement was stopped when the water content of the methanol-dispersed hollow silica sol was below 2.0% by mass, yielding 150g of methanol-dispersed hollow silica sol.

[0327] 30g of the obtained methanol-dispersed hollow silica sol was added to a 50cc round-bottom flask, and 0.27g of pure water was added while stirring with a magnetic stirrer. The resulting methanol-dispersed hollow silica sol had a silica concentration of 21% by mass, a water content of 1.5% by mass, a dynamic light scattering particle size of 66nm, and a specific surface area (C) of 150m² according to the BET method. 2 / g, TEM equivalent specific surface area (D) is 63m² 2 The surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the mass of SiO2 in the hollow silica particles. The amount of aluminum (B) present in the entire particle, converted to Al2O3, is 0.5 ppm relative to the mass of SiO2 in the hollow silica particles. The A / B ratio is 0.20. The sodium content in the methanol-dispersed hollow silica sol is 192 ppm / SiO2, meaning the amount of Na2O contained, expressed as a molar ratio of Na2O to SiO2, is 182 × 10⁻⁶. -6 moles / SiO2.

[0328] The same stability test as in Example 1 was conducted, and the results are shown in Table 1.

[0329] [Example 6]

[0330] (a) Procedure: 150 g of water-dispersed hollow silica sol (manufactured by Ningbo Dilato, trade name: HKT-A20-40D) was placed in a 500 cc round-bottom flask. While stirring with a magnetic stirrer, 0.16 g of diethanolamine was added dropwise. The resulting silica sol had a pH of 9.5, a particle size of 55 nm as determined by dynamic light scattering, an average primary particle size of 43 nm as observed by TEM, a silica concentration of 20% by mass, and a specific surface area (C) of 150 m² as obtained by the BET method. 2 / g, TEM equivalent specific surface area (D) is 63m² 2The specific surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the mass of SiO2 in the hollow silica particles. The amount of aluminum (B) present in the entire particle, converted to Al2O3, is 0.5 ppm relative to the mass of SiO2 in the hollow silica particles (A / B ratio) is 0.20. The sodium content in the water-dispersed hollow silica sol is 14 ppm / SiO2, meaning the amount of Na2O contained, expressed as a molar ratio of Na2O to SiO2, is 6.64 × 10⁻⁶. -6 moles / SiO2.

[0331] (b) Process: Then, 56g of methanol was added to 150g of the obtained water-dispersed hollow silica sol. Using a rotary evaporator, water was removed by distillation while supplying methanol under heating and reduced pressure (bath temperature: 120°C, pressure reduction: 580 Torr) to obtain a methanol dispersion of hollow silica (methanol-dispersed hollow silica sol). The methanol replacement was stopped when the water content of the methanol-dispersed hollow silica sol was below 2.0% by mass, yielding 150g of methanol-dispersed hollow silica sol.

[0332] (c) Process: Then, while stirring with a magnetic stirrer, add a sodium hydroxide aqueous solution diluted with methanol dropwise to 100g of the obtained methanol-dispersed hollow silica sol, so that the sodium content in the water-dispersed hollow silica sol is 384ppm / SiO2, that is, the amount of Na2O contained, calculated as the molar ratio of Na2O to SiO2, is 182.16×10⁻⁶. -6 moles / SiO2.

[0333] The obtained methanol-dispersed hollow silica sol had a silica concentration of 20% by mass, a water content of 1.8% by mass, a particle size of 78 nm according to dynamic light scattering, and a specific surface area (C) of 150 m² according to BET method. 2 / g, the TEM equivalent specific surface area (D) is 63m². 2 The specific surface area ratio (C / D ratio) is 2.4. The amount of aluminum (A) bonded to the particle surface, converted to Al2O3, is 0.1 ppm relative to the mass of SiO2 in the hollow silica particles. The amount of aluminum (B) present in the entire particle, converted to Al2O3, is 0.5 ppm relative to the mass of SiO2 in the hollow silica particles, with an (A / B ratio) of 0.20. The sodium content in the methanol-dispersed hollow silica sol is 384 ppm / SiO2, meaning the amount of Na2O contained, expressed as a molar ratio of Na2O to SiO2, is 182 × 10⁻⁶. -6 moles / SiO2.

[0334] The same stability test as in Example 1 was conducted, and the results are shown in Table 1.

[0335] (Comparative Example 1)

[0336] (a) Procedure: 150g of water-dispersed hollow silica sol (manufactured by Ningbo Dilato, trade name: HKT-A20-40D) was placed into a 500cc eggplant-shaped flask, and 0.16g of diethanolamine was added dropwise while stirring with a magnetic stirrer.

[0337] (b) Process: Then, 56g of methanol was added to 150g of the obtained water-dispersed hollow silica sol. Using a rotary evaporator, water was removed by distillation while supplying methanol under heating and reduced pressure (bath temperature: 120°C, pressure reduction: 580 Torr) to obtain a methanol dispersion of hollow silica (methanol-dispersed hollow silica sol). The methanol replacement was stopped when the water content of the methanol-dispersed hollow silica sol was below 2.0% by mass, yielding 150g of methanol-dispersed hollow silica sol.

[0338] The obtained methanol-dispersed hollow silica sol had a silica concentration of 20% by mass, a water content of 0.8% by mass, and a particle size of 123 nm as determined by dynamic light scattering. The Na₂O content, expressed as a molar ratio of Na₂O to SiO₂, was 6.64 × 10⁻⁶. -6 (molar / SiO2).

[0339] The same stability test as in Example 1 was conducted, and the results are shown in Table 1.

[0340] Table 1

[0341]

[0342] The average particle size, measured by dynamic light scattering, is 20–150 nm, based on a molar ratio of 7.12 × 10⁻⁶ SiO₂ to the hollow silica particles after converting monovalent alkali metal ions to M₂O (where M represents a monovalent alkali metal atom). -6 ~285×10 -6 The proportions contained their sols. Examples 1 to 6 confirmed that the particle size values ​​obtained by dynamic light scattering after storage at 50°C for 48 hours were within 2.0 times that before storage, indicating high stability.

[0343] On the other hand, in the comparative example, even though the average particle size measured by dynamic light scattering was 20–150 nm, the molar ratio of monovalent alkali metal ions to SiO2 in hollow silica particles, after converting them to M2O (where M represents monovalent alkali metal atoms), was less than 7.12 × 10⁻⁶. -6 The proportion of these contained in sol confirmed that the dynamic light scattering particle size value after storage at 50°C for 48 hours was more than 2.0 times that before storage, indicating low stability.

[0344] Furthermore, as shown in Table 1, in Example 6, for particles with an average particle size of 20–150 nm as measured by dynamic light scattering, and a molar ratio of SiO2 to hollow silica particles after converting monovalent alkali metal ions to M2O (where M represents a monovalent alkali metal atom) is less than 7.12 × 10⁻⁶. -6 The sol, after methanol replacement, was adjusted by adding monovalent alkali metal ions. The resulting monovalent alkali metal ions, converted to M₂O (where M represents a monovalent alkali metal atom), had a molar ratio of 7.12 × 10⁻⁶ SiO₂ to the hollow silica particles. -6 ~285×10 -6 The sol of a certain proportion, after being stored at 50°C for 48 hours, showed a particle size value by dynamic light scattering method that was less than 2.0 times that before storage, confirming high stability.

[0345] Industry availability

[0346] This invention relates to aqueous sols and organic solvent sols containing highly stable hollow silica particles, and further to methods for improving the stability of the aforementioned sols that have reduced storage stability, and methods for manufacturing the same.

Claims

1. A hollow silica sol containing hollow silica particles with spaces inside the outer shell and monovalent alkali metal ions. The molar number of the monovalent alkali metal ion converted to M₂O relative to the molar number of SiO₂ in hollow silica particles is 7.12 × 10⁻⁶. -6 ~285×10 -6 The proportions contain hollow silica particles and monovalent alkali metal ions, where M represents a monovalent alkali metal atom. The average particle size of the sol, measured by dynamic light scattering after being stored at 50°C for 48 hours, was within 2.0 times that of the average particle size measured by dynamic light scattering before storage. The monovalent alkali metal ions are lithium ions, sodium ions, and / or potassium ions.

2. The hollow silica sol as described in claim 1, wherein the monovalent alkali metal ion is a sodium ion.

3. The hollow silica sol as described in claim 1 or 2 has an average particle size of 20–150 nm as measured by dynamic light scattering.

4. The hollow silica sol as described in claim 1 or 2 further contains an amine, wherein the amine is 0.001 to 10 SiO2 relative to the hollow silica particles.

5. The hollow silica sol according to claim 4, wherein the amine is at least one amine selected from primary amines, secondary amines and tertiary amines having 1 to 10 carbon atoms.

6. The hollow silica sol as described in claim 4, wherein the amine is a water-soluble amine with a water solubility of 80 g / L or higher.

7. The hollow silica sol as described in claim 1, further wherein the hollow silica particles contain aluminum atoms forming aluminosilicate sites. The aluminum atoms bond with the surface of the hollow silica particles. The mass of this aluminum atom, relative to the mass of SiO2 in the hollow silica particles, is in the range of 100–20000 ppm (Al2O3 equivalent). The atomic mass of aluminum is a value determined by leaching.

8. The hollow silica sol of claim 7, wherein in the determination of the leaching method for leaching aluminum atoms from a compound containing aluminum atoms bonded to the surface of hollow silica particles, an aqueous solution of at least one inorganic acid selected from sulfuric acid, nitric acid, and hydrochloric acid is used.

9. The hollow silica sol as described in claim 7 or 8, wherein the mass of aluminum atoms present in the hollow silica particles as a whole is converted to Al2O3, and the mass of SiO2 relative to the hollow silica particles is expressed as a ratio B of 120 to 50000 ppm. The mass of this aluminum atom is determined by dissolving hollow silica particles in an aqueous solution of hydrofluoric acid. The ratio A to the ratio B is 0.002 to 1.

0.

10. The hollow silica sol as described in claim 1 or 2, comprising hollow silica particles having a ratio of [specific surface area C of silica particles obtained by the BET method, i.e., nitrogen adsorption method] / [specific surface area D of silica particles calculated by transmission electron microscopy] of 1.40 to 5.

00.

11. The hollow silica sol as described in claim 1 or 2, wherein the hollow silica particles contain hollow silica particles with a surface charge of 5 to 250 μeq / g per 1g, calculated in terms of SiO2.

12. The hollow silica sol as claimed in claim 1 or 2, wherein the hollow silica particles further comprise hollow silica particles coated with at least one silane compound selected from the compounds shown in formula (1) and formula (2). In equation (1), R 1 These are groups bonded to silicon atoms, and can independently represent alkyl, haloalkyl, alkenyl, aryl, or organic groups having epoxy, (meth)acryloyl, mercapto, amino, urea, polyether, carboxyl, protected carboxyl, carboxyl-generating, imide, or cyano groups and bonded to silicon atoms via Si-C bonds, or combinations of these groups. R 2 These are groups or atoms bonded to silicon atoms, which independently represent alkoxy, acyloxy, hydroxyl, or halogen atoms having one or more carbon atoms, or combinations of these groups. a represents an integer from 1 to 3. In equation (2), R 3 These are groups bonded to silicon atoms, and can independently represent alkyl, haloalkyl, alkenyl, aryl, or organic groups having an epoxy, (meth)acryloyl, mercapto, amino, urea, polyether, carboxyl, protected carboxyl, carboxyl-generating, imide, or cyano group and bonded to silicon atoms via Si-C bonds, or combinations of these groups. R 4 These are groups or atoms bonded to silicon atoms, which independently represent alkoxy, acyloxy, hydroxyl, or halogen atoms having one or more carbon atoms, or combinations of these groups. Y is a group or atom bonded to a silicon atom, representing an alkylene group, an NH group, or an oxygen atom. b represents an integer from 1 to 3, and c represents an integer of 0 or 1.

13. The hollow silica sol as described in claim 1 or 2, wherein the dispersion medium is water, an alcohol, ketone, ether, amide, urea, or ester having 1 to 10 carbon atoms.

14. A composition for film formation, comprising Hollow silica particles derived from hollow silica sol according to any one of claims 1 to 13, and Organic resins or polysiloxanes.

15. A membrane having a visible light transmittance of 80% or more, obtained from the film-forming composition of claim 14.

16. A method for manufacturing hollow silica sol according to any one of claims 1 to 13, comprising the following steps (I) to (II): (I) Process: The process of preparing hollow silica sol containing a dispersion medium. (II) Process: Add monovalent alkali metal ions to the hollow silica sol in process (I), and adjust the molar ratio of the monovalent alkali metal ions (converted to M2O) to the SiO2 of the hollow silica particles to 7.12 × 10⁻⁶. -6 ~285×10 -6 The proportion of the monovalent alkali metal ions is lithium ions, sodium ions, and / or potassium ions, and M in M2O represents a monovalent alkali metal atom.

17. The method for manufacturing hollow silica sol as described in claim 16, wherein in step (II), the monovalent alkali metal ion is sodium ion.

18. The method for manufacturing hollow silica sol as claimed in claim 17, wherein the sodium ion content in step (II) is adjusted by contacting the hollow silica sol obtained in step (I) with a cation exchange resin or by adding a sodium source.

19. The method for manufacturing hollow silica sol as described in claim 17, wherein in step (II), the addition of sodium source is the addition of sodium hydroxide.

20. The method for manufacturing hollow silica sol according to any one of claims 16 to 19, wherein the dispersion medium in steps (I) and (II) is water, an alcohol, ketone, ether, amide, urea or ester having 1 to 10 carbon atoms.

21. The method for manufacturing hollow silica sol as described in any one of claims 16 to 19, wherein at least one step selected from (i) to (iv) is added to step (I), step (II), or both of these steps. (i): Adding amines to hollow silica sol, (ii): Sodium aluminate is added as an aluminum source and heated to form aluminosilicate sites in hollow silica particles. (iii): Replace the dispersion medium with another dispersion medium. (iv): The hollow silica particles are then coated with at least one silane compound selected from formula (1) and formula (2).

22. The stabilization method for hollow silica sol according to claim 1 is a method for stabilizing hollow silica sol containing hollow silica particles with spaces inside the shell, characterized in that... The monovalent alkali metal ions were added to a hollow silica sol whose average particle size, as measured by dynamic light scattering, was larger than that during manufacturing, such that the molar number of the monovalent alkali metal ions converted to M₂O was 7.12 × 10⁻⁶ molars of SiO₂ in the hollow silica sol. -6 ~285×10 -6 The molar ratio reduces the increased average particle size measured by dynamic light scattering, wherein the monovalent alkali metal ion is lithium ion, sodium ion and / or potassium ion, and M in M2O represents a monovalent alkali metal atom.

23. The stabilization method for hollow silica sol as described in claim 22, wherein the monovalent alkali metal ion is a sodium ion.

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