Dispersion liquid, dispersion liquid set, low refractive index layer, optical member, optical device, method for manufacturing low refractive index layer, method for manufacturing optical member, and method for manufacturing optical device

Abstract

To provide a dispersion liquid capable of ensuring the film thickness of a low refractive index layer and achieving in-plane film thickness uniformity.　The dispersion liquid, in which particles are dispersed in a dispersion medium, is characterized in that the particles are the condensation product of a raw material containing alkoxysilane, the concentration of the particles in the dispersion liquid is 3.5-18.5 wt %, and the viscosity of the dispersion liquid is at least 4 mPa·s and less than 5000 mPa·s.

Description

Dispersion, dispersion set, low refractive index layer, optical component, optical device, method for manufacturing a low refractive index layer, method for manufacturing an optical component, and method for manufacturing an optical device

[0001] This disclosure relates to a dispersion, a dispersion set, a low refractive index layer, an optical component, an optical device, a method for manufacturing a low refractive index layer, a method for manufacturing an optical component, and a method for manufacturing an optical device.

[0002] In optical devices, for example, an air layer with a low refractive index is used as a total reflection layer. Specifically, for example, in liquid crystal devices, each optical film component (e.g., a light guide plate and a reflector plate) is laminated with an air layer in between. However, when components are separated by an air layer, problems such as component deflection may occur, especially when the components are large.

[0003] Therefore, it has been proposed to use a low refractive index layer instead of an air layer. For example, a method has been used in which a low refractive index layer is formed on a light guide plate, optically isolating the light guided into the light guide plate, and guiding the light without being affected by external factors such as dirt or scratches on the light guide plate. Patent Document 1 describes a method in which a low refractive index layer is laminated via an adhesive layer that is bonded to the light guide plate for the purpose of protecting the light.

[0004] As a method for forming such a low refractive index layer, for example, Patent Document 2 describes the application of a coating solution by roll-to-roll application.

[0005] Patent No. 6606518 Patent No. 6599699

[0006] As described in Patent Document 1, when a low refractive index layer is laminated via an adhesive layer, the light guided through the light guide plate passes through the adhesive layer before total internal reflection occurs at the low refractive index layer. This can lead to color shifts and light scattering originating from the adhesive layer, potentially resulting in light guide loss. Therefore, a method has been proposed in which a coating liquid is directly applied to the light guide plate to form the low refractive index layer without using an adhesive layer.

[0007] However, since light guide plates are manufactured in batches, direct coating with liquid requires a batch coating machine, spin coating, spray coating, dipping, or other coating methods different from die coating used in normal roll coating. Among these batch coating methods, spin coating is the easiest to ensure in-plane smoothness. However, the liquid for forming the low refractive index layer described in Patent Document 2 is designed based on a roll-to-roll coating method, and is therefore insufficient for ensuring film thickness after drying in spin coating and for considering the spread of the liquid during spin coating. In particular, for AR / MR glasses, which are small device components, ensuring the film thickness of the low refractive index layer and in-plane film thickness uniformity are important in order to maintain the parallelism between light guide plates, and in the design of the liquid for spin coating, it is necessary to appropriately manage and design items such as viscosity and concentration.

[0008] Therefore, the present disclosure aims to provide a dispersion, a dispersion set, a low refractive index layer, an optical component, an optical device, a method for manufacturing a low refractive index layer, a method for manufacturing an optical component, and a method for manufacturing an optical device, all of which are capable of ensuring the thickness of a low refractive index layer and achieving uniformity of the in-plane film thickness.

[0009] To achieve the above objective, the dispersion of the present disclosure is a dispersion in which particles are dispersed in a dispersion medium, wherein the particles are condensates of raw materials containing alkoxysilane, the concentration of the particles in the dispersion is 3.5% by weight or more and less than 18.5% by weight, and the viscosity of the dispersion is 4 mPa·s or more and less than 5000 mPa·s.

[0010] The dispersion set of the present disclosure is characterized by comprising the dispersion of the present disclosure and a catalyst-containing liquid containing a catalyst for chemically binding the particles of the dispersion.

[0011] The low refractive index layer of the present disclosure is characterized by being obtained by coating with the dispersion or dispersion set of the present disclosure and drying it.

[0012] The optical component of this disclosure is characterized by including a low refractive index layer of this disclosure.

[0013] The optical device disclosed herein is characterized by including an optical component.

[0014] A method for manufacturing a low refractive index layer according to the present disclosure is characterized by comprising the steps of coating a dispersion or a set of dispersions according to the present disclosure onto a substrate, and drying the coated dispersion.

[0015] The method for manufacturing an optical component according to the present disclosure is a method for manufacturing an optical component including a low refractive index layer, characterized in that the low refractive index layer is manufactured by the manufacturing method according to the present disclosure.

[0016] The method for manufacturing an optical device according to the present disclosure is a method for manufacturing an optical device including an optical component, characterized in that the optical component is manufactured by the manufacturing method according to the present disclosure.

[0017] According to this disclosure, it is possible to provide a dispersion, a dispersion set, a low refractive index layer, an optical component, an optical device, a method for manufacturing a low refractive index layer, a method for manufacturing an optical component, and a method for manufacturing an optical device, all of which enable securing the film thickness of a low refractive index layer and achieving uniformity of the film thickness in the plane.

[0018] Next, we will provide a more detailed explanation of this disclosure with examples. However, this disclosure is not limited in any way by the following explanation.

[0019] In this disclosure, the "solvent" (e.g., a solvent for gel production used in the production of a dispersion, a substitution solvent, a solvent for producing a low refractive index layer, etc.) does not necessarily have to dissolve the gel or its pulverized material, particles, etc. For example, the gel or its pulverized material, etc. may be dispersed or precipitated in the solvent. For example, an organic solvent may be used as the dispersion medium in the dispersion of this disclosure.

[0020] In this disclosure, “adhesive layer” means a layer formed by at least one of an adhesive and an adhesive. In this disclosure, unless otherwise specified, “adhesive layer” may be an “adhesive layer” formed by an adhesive, an “adhesive layer” formed by an adhesive, or a layer containing both an adhesive and an adhesive. In this disclosure, adhesives and adhesives may be collectively referred to as “adhesive.” Generally, agents with relatively weak adhesive strength (e.g., agents that allow for re-peeling of the bonded object) are sometimes called “adhesives,” and agents with relatively strong adhesive strength (e.g., agents that make re-peeling of the bonded object impossible or extremely difficult) are sometimes called “adhesives.” In this disclosure, there is no clear distinction between adhesives and adhesives. Also, in this disclosure, there is no clear distinction between “adhesive strength” and “bonding strength.”

[0021] In this disclosure, unless otherwise specified, "mass%" and "weight%" may be interpreted as interchangeable, and "parts of mass" and "parts of weight" may be interpreted as interchangeable.

[0022] Furthermore, in this disclosure, "on top of" or "on the surface" may refer to a state of direct contact with the top of or on the surface, or it may refer to a state of contact with other layers, etc.

[0023] [1. Dispersion] The dispersion of the present disclosure is, as described above, a dispersion in which particles are dispersed in a dispersion medium, wherein the particles are condensates of raw materials containing alkoxysilane, the concentration of the particles in the dispersion is 3.5% by weight or more and less than 18.5% by weight, and the viscosity of the dispersion is 4 mPa·s mPa·s or more and less than 5000 mPa·s.

[0024] The dispersion of the present disclosure is characterized in that the concentration of the particles in the dispersion is 3.5% or more and less than 18.5% by weight, or alternatively, a dispersion in which solid components containing particles are dispersed in a dispersion medium, wherein the concentration of the solid components in the dispersion is 3.5% or more and less than 22% by weight.

[0025] [1-1. Particles of Condensed Raw Materials Containing Alkoxysilane] In the dispersion of the present disclosure, the particles are, as described above, condensed raw materials containing alkoxysilane. The alkoxysilane may be, for example, a saturated alkoxysilane or an unsaturated alkoxysilane having an unsaturated group that is ultraviolet polymerizable. The saturated alkoxysilane may be, for example, a monomer, an oligomer, or a combination thereof. Specific examples of the saturated alkoxysilane monomer include methyltrimethoxysilane, methyltriethoxysilane, phenyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, diethoxydimethoxysilane, dimethyldimethoxysilane, and dimethyldiethoxysilane, and these may be used individually or in combination of multiple types. The saturated alkoxysilane oligomer is preferably a condensed polymer of one or more of the above monomers. The saturated alkoxysilane oligomer can be obtained, for example, by hydrolysis polymerization of the monomer. The alkoxysilane is preferably an alkoxysilane having three or fewer functional groups (saturated bond functional groups). The unsaturated alkoxysilane may be, for example, a monomer, an oligomer, or a combination thereof. The unsaturated alkoxysilane monomer has, for example, an organic group having at least one double or triple bond and an alkoxy group.

[0026] In the dispersion of the present disclosure, the particles may be, for example, particles of a silsesquioxane condensate which is a condensate of a raw material containing a trifunctional organosilicon compound. In this case, the particles may be, for example, a condensate of a raw material consisting only of a trifunctional organosilicon compound, or a condensate of a raw material containing a trifunctional organosilicon compound and other monomers. The content of the trifunctional organosilicon compound in the raw material (monomer) may be, for example, 0.1 mol% or more, 10 mol% or more, 30 mol% or more, 50 mol% or more, or 90 mol% or more, for example, 100 mol% or less, 99 mol% or less, 90 mol% or less, 70 mol% or less, or 50 mol% or less, for example, 0.1 to 100 mol%, 1 to 99 mol%, 10 to 90 mol%, or 30 to 70 mol%.

[0027] The raw material (monomer) of the particles may contain, for example, an organosilicon compound represented by the following formula (1). In this case, the raw material may further contain other components or may not contain other components. Since the organosilicon compound of the following formula (1) has a hydroxyl group, for example, hydrogen bonds or intermolecular force bonds are possible through each hydroxyl group.

[0028]

[0029] In the formula (1), for example, X is 2, 3, or 4. However, at least a part of the raw material represented by the formula (1) is a trifunctional organosilicon compound in which X is 3, and R １ is a linear or branched alkyl group. The carbon number of the R １ is, for example, 1 to 6, 1 to 4, or 1 to 2, for example. Examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, etc., and examples of the branched alkyl group include an isopropyl group, an isobutyl group, etc. The X is, for example, 3 or 4.

[0030] Among the organosilicon compounds represented by the formula (1), the trifunctional organosilicon compound in which X is 3 can be represented by the following formula (1'). In the following formula (1'), R １ is the same as in the formula (1), for example, a methyl group. When R １ is a methyl group, the organosilicon compound is tris(hydroxy)methylsilane. When X is 3, the organosilicon compound is, for example, a trifunctional silane having three functional groups.

[0031]

[0032] Further, specific examples of the silicon compound represented by the formula (1) include, for example, a compound in which X is 4. In this case, the silicon compound is, for example, a tetrafunctional silane having four functional groups.

[0033] The silicon compound may be, for example, a precursor that forms the silicon compound of the formula (1) by hydrolysis. As the precursor, for example, any compound that can generate the silicon compound by hydrolysis may be used. Specific examples include compounds represented by the following formula (2).

[0034] In the formula (2), for example, X is 2, 3, or 4, and R １ and R ２ are each a linear or branched alkyl group, and R １ and R ２ may be the same or different, and R １ may be the same or different from each other when X is 2, and R ２ may be the same or different from each other.

[0035] The X and R １ are, for example, the same as X and R １ in the formula (1) described later. Also, the R ２ is, for example, the same as R １ in the formula (1) described later, and the examples thereof can be cited. <0000​​​​​​​​​​​​​​​In this disclosure, the particles of the condensate of the raw material containing alkoxysilane may be a condensate containing, for example, an organic polymer or monomer. The condensate may be, for example, a polymer of the raw material containing alkoxysilane and an organic polymer. Furthermore, for example, a silica porous film with a higher porosity can be obtained by coating a coating solution containing particles of a condensate containing an organic polymer or monomer, and then heating it to remove all or part of the organic polymer or monomer.

[0039] In this disclosure, particles of a condensate of raw materials containing alkoxysilane can be produced, for example, as a sol particle liquid in which particles are dispersed in a dispersion medium. The method for producing the sol particle liquid is not particularly limited, but for example, it can be produced by grinding a gel of a condensate of raw materials containing alkoxysilane in a dispersion medium. The method for producing the gel of a condensate of raw materials containing alkoxysilane is also not particularly limited, but for example, it can be produced in a manner similar to the method for producing a silicon compound gel described in International Publication No. 2019 / 065999 or International Publication No. 2019 / 065803. The method for grinding the gel of a condensate of raw materials containing alkoxysilane in a dispersion medium is also not particularly limited, but for example, the method described in Japanese Patent No. 7182358 may be used. The type of dispersion medium in the sol particle liquid is also not particularly limited, but for example, it may be the same as the dispersion medium for the sol particle liquid described in International Publication No. 2019 / 065999 or International Publication No. 2019 / 065803. Furthermore, the sol particle liquid can also be manufactured, for example, by the method described in "Reference Example 1" of the embodiments of this application, which will be described later.

[0040] The dispersion medium in the dispersion of the Dispersion of this Disclosure is not particularly limited, but specifically, it may be water, an organic solvent, or a mixed solvent of water and an organic solvent, and the organic solvent may be used alone or in combination of multiple types. Examples of the organic solvent include alcohols, ethers, and ketones. Examples of the alcohol include ethanol, IPA (isopropyl alcohol), IBA (isobutyl alcohol), and hexanol. Examples of the ether include PGMEA (propylene glycol monomethyl ether acetate), diethylene glycol monomethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, and triethylene glycol monomethyl ether. Examples of the ketone include acetone and cyclopentanone.

[0041] From the viewpoint of minimizing the haze value of the low refractive index layer produced from the dispersion of the present disclosure, it is preferable that the particle size D50 of the condensate of the raw materials containing the alkoxysilane is not too large. However, if D50 is small, the viscosity of the dispersion of the present disclosure tends to be low. In that case, the viscosity of the dispersion of the present disclosure can be increased, for example, by increasing the concentration of the particles or the solid content in the dispersion of the present disclosure. In the dispersion of the present disclosure, it is preferable that the particle size D50 is 20 nm or more and 400 nm or less. The particle size D50 of the aforementioned particles may be, for example, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, or 50 nm or more, or for example, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, 130 nm or less, 120 nm or less, 100 nm or less, or 80 nm or less, or for example, 20 to 120 nm, 30 to 120 nm, or 40 to 100 nm.

[0042] In the dispersion of the present disclosure, the specific surface area of ​​the particles of the condensate of the raw materials containing the alkoxysilane is preferably not too small from the viewpoint of reducing the refractive index of the film, and preferably not too large from the viewpoint of durability. The specific surface area of ​​the particles is, for example, 350 m². ２ / g or more, 400m ２ / g or more, 450m２ It may be more than / g, for example, 1000m ２ / g or less, 900m ２ / g or less, 800m ２ / g or less, 750m ２ / g or less, or 700m ２ It may be less than / g, for example, 350 to 1000 m ２ / g, 400-800m ２ / g, 450-750m ２ It may be / g. In this disclosure, the specific surface area of ​​the particles of the condensate of the raw material containing the alkoxysilane shall be the value measured by the following measurement method.

[0043] <Method for Measuring the Specific Surface Area of ​​Particles> The specific surface area of ​​particles is measured using the following procedure. [1. Preparation of Measurement Samples] Take approximately 10 mL each (approximately 50 mL total) of the dispersion of particles to be measured (liquid sample) into separate aluminum cups and dry the liquid samples at 80°C for 24 hours using a vacuum dryer. [2. Pretreatment of Measurement Samples] 1) Start the pretreatment device BELPREP-vacII (product name of Microtrac) and heat it to 150°C. 2) Set a dedicated sample tube in the BELPREP-vacII and replace the air inside the sample tube with purge gas. 3) Measure the blank weight of the sample tube from step 2). 4) Introduce the sample dried in [1. Preparation of Measurement Samples] into the sample tube from step 3). 5) Measure the weight from step 4) and subtract the blank weight measured in step 3) to determine the sample mass before pretreatment. 6) Secure the sample tube from 5) to the mounting tube of the BELPREP-vacII and place it in the heat dissipation zone. 7) Press the PORT button on the BELPREP-vacII, then press the VAC button. 8) Move the sample tube from 6) to the heater section of the BELPREP-vacII, press the HEAT button, and heat at 150°C for 1 hour. 9) After the sample tube has cooled, press the PURGE button on the BELPREP-vacII. After completion, measure the mass of the sample tube. [3. Measurement of the sample] 1) Press the measurement start button on the BELPREP-vacII. 2) Remove the Dewar flask holder from the main body of the BELPREP-vacII, fill it with liquid nitrogen up to the neck of the Dewar flask, and set it in the main body. 3) Set the sample tube in the main body and perform the measurement; the specific surface area will be displayed as numerical data.

[0044] In the dispersion of the present disclosure, the pore volume of the particles of the condensate of the raw materials containing the alkoxysilane is preferably not too small from the viewpoint of reducing the refractive index, and preferably not too large from the viewpoint of durability. The pore volume of the particles is, for example, 0.8 cm². ３ / g or more, 1.0cm or more ３ / g or more, or 1.2cm ３ It may be more than / g, for example, 2.0 cm３ / g or less, 1.8cm ３ / g or less or 1.5cm ３ It may be less than or equal to / g. In this disclosure, the pore volume of the particles of the condensate of the raw materials containing the alkoxysilane shall be the value of the average pore volume measured by the measurement method described below.

[0045] <Method for Measuring the Pore Volume of Particles> The average pore volume of particles is measured using the following procedure. [1. Preparation of Measurement Samples] Take approximately 10 mL each (approximately 50 mL total) of the dispersion of particles to be measured (liquid sample) into separate aluminum cups and dry the liquid samples at 80°C for 24 hours using a vacuum dryer. [2. Pretreatment of Measurement Samples] 1) Start the pretreatment device BELPREP-vacII (product name of Microtrac) and heat it to 150°C. 2) Set a dedicated sample tube in the BELPREP-vacII and replace the air inside the sample tube with purge gas. 3) Measure the blank weight of the sample tube from step 2). 4) Introduce the sample dried in [1. Preparation of Measurement Samples] into the sample tube from step 3). 5) Measure the weight from step 4) and subtract the blank weight measured in step 3) to determine the sample mass before pretreatment. 6) Secure the sample tube to the mounting tube of the BELPREP-vacII and place it in the heat dissipation zone. 7) Press the PORT button on the BELPREP-vacII, then press the VAC button. 8) Move the sample tube from 6) to the heater section of the BELPREP-vacII and press the HEAT button, heating at 150°C for 1 hour. 9) After the sample tube has cooled, press the PURGE button on the BELPREP-vacII. After completion, measure the mass of the sample tube. [3. Measurement of the sample] 1) Press the measurement start button on the BELPREP-vacII. 2) Remove the Dewar flask holder from the main body of the BELPREP-vacII, fill it with liquid nitrogen up to the neck of the Dewar flask, and set it in the main body. 3) Set the sample tube in the main body and perform the measurement, and the average pore volume will be displayed as numerical data.

[0046] In the dispersion of the present disclosure, the specific surface area of ​​the particles of the condensate of the raw materials containing the alkoxysilane is determined by the size and number of pores in the particles. Therefore, the pore diameter of the particles of the condensate of the raw materials containing the alkoxysilane is preferably within a predetermined range from the viewpoint of film refractive index and durability. The pore diameter of the particles may be, for example, 5 nm or more or 7 nm or more, or for example, 17 nm or less or 15 nm or less. In the present disclosure, the pore diameter of the particles of the condensate of the raw materials containing the alkoxysilane is the numerical value of the average pore diameter measured by the measurement method described below.

[0047] <Method for Measuring Particle Pore Diameter> The average pore diameter of the particles is measured using the following procedure. [1. Preparation of Measurement Sample] Approximately 10 mL each (approximately 50 mL total) of the dispersion of particles to be measured (liquid sample) is placed in separate aluminum cups, and the liquid samples are dried at 80°C for 24 hours using a vacuum dryer. [2. Pretreatment of Measurement Sample] 1) Start the pretreatment device BELPREP-vacII (product name of Microtrac) and heat it to 150°C. 2) Set a dedicated sample tube in the BELPREP-vacII and replace the air inside the sample tube with purge gas. 3) Measure the blank weight of the sample tube from step 2). 4) Introduce the sample dried in [1. Preparation of Measurement Sample] into the sample tube from step 3). 5) Measure the weight from step 4), and subtract the blank weight measured in step 3) from that weight to determine the sample mass before pretreatment. 6) Secure the sample tube to the mounting tube of the BELPREP-vacII and place it in the heat dissipation zone. 7) Press the PORT button on the BELPREP-vacII, then press the VAC button. 8) Move the sample tube from 6) to the heater section of the BELPREP-vacII, press the HEAT button, and heat at 150°C for 1 hour. 9) After the sample tube has cooled, press the PURGE button on the BELPREP-vacII. After completion, measure the mass of the sample tube. [3. Measurement of the sample] 1) Press the measurement start button on the BELPREP-vacII. 2) Remove the Dewar flask holder from the main body of the BELPREP-vacII, fill it with liquid nitrogen up to the neck of the Dewar flask, and set it in the main body. 3) Set the sample tube in the main body and perform the measurement. The average pore diameter will be displayed as numerical data.

[0048] [1-2. Dispersion and Method for Producing the Dispersion] The method for producing the dispersion of the present disclosure is not particularly limited, but for example, it can be produced as follows.

[0049] First, a sol particle liquid is prepared in which particles of a condensate of a raw material containing alkoxysilane are dispersed in a dispersion medium. The particles of the condensate of the raw material containing alkoxysilane may be, for example, particles of a silsesquioxane condensate, as described above. The sol particle liquid can be prepared, for example, by the method described above. The concentration of the particles of the condensate of the raw material containing alkoxysilane in the sol particle liquid at this stage is not particularly limited, but may be, for example, 0.5% by weight or more, 1.0% by weight or more, 2.0% by weight or more, 2.5% by weight or more, or 3.0% by weight or more, for example, 3.5% by weight or less, 3.4% by weight or less, 3.3% by weight or less, 3.2% by weight or less, or 3.1% by weight or less, for example, 0.5 to 3.5% by weight, 1.0 to 3.4% by weight, 2.0 to 3.3% by weight, 2.5 to 3.2% by weight, or 3.0 to 3.1% by weight. Furthermore, the concentration of components other than the dispersion medium in the sol particle liquid at this stage (hereinafter sometimes referred to as "solid content" or "solid components") is not particularly limited, but may be, for example, 0.5% by weight or more, 1.0% by weight or more, 2.0% by weight or more, 2.5% by weight or more, or 3.0% by weight or more, or for example, 3.5% by weight or less, 3.4% by weight or less, 3.3% by weight or less, 3.2% by weight or less, or 3.1% by weight or less, or for example, 0.5 to 3.5% by weight, 1.0 to 3.4% by weight, 2.0 to 3.3% by weight, 2.5 to 3.2% by weight, or 3.0 to 3.1% by weight.

[0050] In this disclosure, the particle size can be measured by, for example, a laser diffraction particle size analyzer or a dynamic light scattering particle size analyzer (DLS). However, in this disclosure, it is preferable to measure the particle size using a dynamic light scattering particle size analyzer (DLS) to obtain a more accurate value from the target particle size. By measuring the particle size distribution using these measurement methods, the particle size D50 can be calculated. D50 is a value also called the median diameter, and it is the particle size of the median of the particle size distribution, corresponding to a cumulative frequency of 50%. In this disclosure, the particle size distribution and the particle size D50 are the values ​​measured and calculated by the following measurement methods.

[0051] <Method for Measuring Particle Size Distribution (DLS)> First, the sample containing the particles to be measured is diluted with IBA (isobutyl alcohol) to a particle concentration of 1.5%. This solution is then placed in a 6 x 50 mm glass tube, filling it to about 80%, to create an evaluation sample. The sample is then placed in a particle size distribution analyzer (Entegris: Nicomp N3000) and the particle size distribution is measured. From this particle size distribution, the particle size D50 is calculated. As mentioned above, D50 is the median particle size in the particle size distribution and corresponds to a cumulative frequency of 50%.

[0052] Next, a "first grinding step" is performed to grind the particles in the sol particle liquid. The grinding method in the first grinding step is not particularly limited, but for example, the method described in Japanese Patent Publication No. 7182358 may be used. Among these, high-pressure medialess grinding is preferred. The pressure in the first grinding step is not particularly limited, but for example, it may be 30 MPa or more, 50 MPa or more, 70 MPa or more, 100 MPa or more, or 150 MPa or more, for example, 350 MPa or less, 300 MPa or less, 250 MPa or less, 200 MPa or less, or 180 MPa or less, for example, 30 to 350 MPa, 50 to 300 MPa, 70 to 250 MPa, 100 to 200 MPa, or 150 to 180 MPa. The particle size D50 of the condensate of the raw material containing the alkoxysilane after the first grinding step is not particularly limited, but may be, for example, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, or 50 nm or more, or for example, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, or 150 nm or less, or for example, 25 to 350 nm, 30 to 300 nm, 35 to 250 nm, 40 to 200 nm, or 50 to 150 nm.

[0053] Next, a "concentration step" is performed to concentrate the sol particle liquid after the first grinding step. The concentration method in the concentration step is not particularly limited, and may be, for example, heating or pressurizing, but pressurizing is preferred. More specifically, for example, the liquid may be concentrated to a predetermined concentration by pressurizing using a filter, or the liquid may be concentrated to a predetermined concentration by partially removing the dispersion medium by heating or the like. The filter is also not particularly limited, but examples include rotary ceramic membrane filters and cross-flow filters. An example of a rotary ceramic membrane filter is the product name "Mitsubishi Dynafilter (DyF)" manufactured by Mitsubishi Chemical Machinery Ltd. The concentration of particles of the condensate of the raw material containing the alkoxysilane in the sol particle liquid after the concentration step is not particularly limited, but may be, for example, 3.6% by weight or more, 4.0% by weight or more, 4.5% by weight or more, 5.0% by weight or more, or 5.5% by weight or more, or for example, 40% by weight or less, 30% by weight or less, 20% by weight or less, 18% by weight or less, or 15% by weight or less, or for example, 3.6 to 40% by weight, 4.0 to 30% by weight, 4.5 to 20% by weight, 5.0 to 18% by weight, or 5.5 to 15% by weight. The concentration of solids (solid components) in the sol particle liquid after the concentration step is not particularly limited, but may be, for example, 3.6% by weight or more, 3.8% by weight or more, 4.0% by weight or more, 4.1% by weight or more, or 4.2% by weight or more, or for example, 39% by weight or less, 38% by weight or less, 37% by weight or less, 36% by weight or less, or 35% by weight or less, or for example, 3.6 to 39% by weight, 3.8 to 38% by weight, 4.0 to 37% by weight, 4.1 to 36% by weight, or 4.2 to 35% by weight.

[0054] Next, a "second grinding step" is performed to grind the particles in the sol particle liquid after the concentration step. The grinding method in the second grinding step is not particularly limited, but for example, the method described in Japanese Patent No. 7182358 may be used. Among these, high-pressure medialess grinding is preferred. The pressure in the second grinding step is not particularly limited, but for example, it may be 30 MPa or more, 50 MPa or more, 70 MPa or more, 100 MPa or more, or 150 MPa or more, for example, 350 MPa or less, 300 MPa or less, 250 MPa or less, 200 MPa or less, or 180 MPa or less, for example, 30 to 350 MPa, 50 to 300 MPa, 70 to 250 MPa, 100 to 200 MPa, or 150 to 180 MPa. The particle size D50 of the condensate of the raw material containing the alkoxysilane after the second grinding step may be, for example, within the numerical range of 20 nm to 400 nm as described above.

[0055] Furthermore, a "liquid concentration adjustment step" is performed in which a dispersion medium is added to the sol particle liquid after the second grinding step to adjust the liquid concentration, thereby producing the dispersion liquid of the present disclosure. At this time, the viscosity of the dispersion liquid is set to be 4 mPa·s or more and less than 5000 mPa·s, which is the viscosity of the dispersion liquid of the present disclosure. If the viscosity of the dispersion liquid is too low, exceeding the range of the present disclosure, it will not be possible to secure the film thickness of the low refractive index layer. If the viscosity of the dispersion liquid is too high, exceeding the range of the present disclosure, the variation in the film thickness of the low refractive index layer will become large (in-plane film thickness uniformity will not be achieved), or cracks will occur in the low refractive index layer during drying, making it impossible to form the low refractive index layer itself. The viscosity of the dispersion of this disclosure may be, for example, 5 mPa·s or more, 6 mPa·s or more, 7 mPa·s or more, 8 mPa·s or more, 9 mPa·s or more, 10 mPa·s or more, 11 mPa·s or more, 12 mPa·s or more, 13 mPa·s or more, 14 mPa·s or more, 15 mPa·s or more, 16 mPa·s or more, 17 mPa·s or more, 18 mPa·s or more, or 20 mPa·s or more, for example, 5000 mPa·s or less, 4000 mPa·s or less, The pressure may be 3500 mPa·s or less, 3000 mPa·s or less, 2000 mPa·s or less, 1200 mPa·s or less, 1000 mPa·s or less, 500 mPa·s or less, 400 mPa·s or less, 300 mPa·s or less, 200 mPa·s or less, 100 mPa·s or less, 50 mPa·s or less, 40 mPa·s or less, 30 mPa·s or less, or 28 mPa·s or less, for example, 4 to 2000 mPa·s or 4 to 1200 mPa·s. In this case, the concentration of particles of the condensate of the raw material containing the alkoxysilane in the dispersion is, for example, 3.5% or more and less than 18.5% by weight, which is within the range of the first dispersion of this disclosure. The concentration of particles of the condensate of the raw material containing alkoxysilane in the dispersion of this disclosure is preferably not too low from the viewpoint of ensuring the thickness of the low refractive index layer. The concentration of particles of the condensate of the raw material containing alkoxysilane in the dispersion of this disclosure is preferably not too high from the viewpoint of suppressing or preventing large variations in the thickness of the low refractive index layer (making it impossible to achieve uniformity of the in-plane thickness) and preventing cracks from forming in the low refractive index layer during drying. However, from the viewpoint of reducing variations in thickness, a higher particle concentration is preferable.The concentration of particles of the condensate of the raw materials containing the alkoxysilane in the dispersion of the present disclosure may be, for example, 3.6% by weight or more, 4.0% by weight or more, 4.5% by weight or more, 5.0% by weight or more, 5.5% by weight or more, 6% by weight or more, 7% by weight or more, 8% by weight or more, 9% by weight or more, or greater than 15% by weight. For example, it may be less than 18.5% by weight, 18% by weight or less, 15% by weight or less, 12% by weight or less, 10% by weight or less, 8% by weight or less, or 6% by weight or less. For example, it may be 6.0% by weight or more and less than 18.5% by weight, or greater than 15% by weight and less than 18.5% by weight. The concentration of solids (solid components) in the sol particle liquid after the concentration step is not particularly limited, but may be, for example, within the range of 3.5% to less than 22% by weight mentioned above. From the viewpoint of ensuring the thickness of the low refractive index layer, it is preferable that the concentration of solids in the dispersion of the present disclosure is not too low. The concentration of solids in the dispersion of this disclosure is preferably not too high, from the viewpoint of preventing or suppressing the large variation in the film thickness of the low refractive index layer (making it impossible to achieve uniformity of in-plane film thickness) and the occurrence of cracks in the low refractive index layer during drying, which would prevent the formation of the low refractive index layer itself. The concentration of solids in the dispersion of this disclosure may be, for example, 3.6% by weight or more, 3.8% by weight or more, 4.0% by weight or more, 4.1% by weight or more, 4.2% by weight or more, or 6.0% by weight or more, for example, less than 22% by weight, 21% by weight or less, 17% by weight or less, 13% by weight or less, or 10% by weight or less, for example, 6.0% by weight or more and less than 22.0% by weight. In addition, a crosslinking aid (also called a crosslinking agent), a catalyst, etc., which promotes crosslinking between particles of the condensate of the raw materials containing the alkoxysilane and is used for producing a low refractive index layer, may be added together with the dispersion medium. The aforementioned crosslinking bond is not particularly limited, but may be a bond formed by covalent bonding between particles of the condensate of the raw material containing the alkoxysilane, either directly or via the crosslinking aid. The aforementioned crosslinking aid is not particularly limited, but may be a substance having multiple functional groups capable of forming covalent bonds with particles of the condensate of the raw material containing the alkoxysilane. Specific examples of the aforementioned crosslinking aid include bis(trimethoxysilyl)alkylene.Examples of the bis(trimethoxysilyl)alkylene include bis(trimethoxysilyl)hexane. Other examples of the crosslinking aid are not particularly limited, but are, for example, as described in Japanese Patent Publication No. 7182358. The concentration of the crosslinking aid in the dispersion of this disclosure is not particularly limited, but is, for example, as described in Japanese Patent Publication No. 7182358. The catalyst is not particularly limited, and may be, for example, a photoactive catalyst or a thermally activated catalyst, or an acid catalyst or a base catalyst. In addition to or in place of the catalyst, a substance that generates a catalyst (catalyst generator) may be used. For example, in addition to or in place of the photoactive catalyst, a substance that generates a catalyst by light (photocatalyst generator) may be used, or in addition to or in place of the thermally activated catalyst, a substance that generates a catalyst by heat (thermal catalyst generator) may be used. The aforementioned photocatalyst generator is not particularly limited, but examples include photobase generators (substances that generate basic catalysts upon light irradiation) and photoacid generators (substances that generate acidic catalysts upon light irradiation), with photobase generators being preferred.Examples of the aforementioned photobase generators include 9-anthrylmethyl N,N-diethylcarbamate (trade name WPBG-018), (E)-1-[3-(2-hydroxyphenyl)-2-propenoyl]piperidine (trade name WPBG-027), 1-(anthraquinon-2-yl)ethyl imidazolecarboxylate (trade name WPBG-140), 2-nitrophenylmethyl 4-methacryloyloxypiperidine-1-carboxylate (trade name WPBG-165), and 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidium Examples include 2-(3-benzoylphenyl)propionate (trade name WPBG-266), 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidium n-butyltriphenyl borate (trade name WPBG-300), and 1,5,7-triazabicyclo[4.4.0]deca-5-ene 2-(9-oxoxanthene-2-yl)propionic acid (Tokyo Chemical Industries, Ltd.), and compounds containing 4-piperidine methanol (trade name HDPD-PB100: manufactured by Heraeus). Note that all trade names containing "WPBG" are trade names of Wako Pure Chemical Industries, Ltd. Examples of photoacid generators include aromatic sulfonium salts (trade name SP-170: ADEKA), triarylsulfonium salts (trade name CPI101A: Sunapro), and aromatic iodonium salts (trade name Irgacure250: Ciba Japan). The concentration of the catalyst or catalyst generator in the dispersion of this disclosure is not particularly limited, but is, for example, as described in Japanese Patent Publication No. 7182358.

[0056] The dispersion of the present disclosure can be manufactured in the manner described above. However, the method for manufacturing the dispersion of the present disclosure is not limited thereto, and any manufacturing method is acceptable as long as it satisfies the conditions of the dispersion of the present disclosure. For example, the method for manufacturing the dispersion of the present disclosure may or may not include some or all of the above-described steps, and may or may not include steps other than those described above. For example, the grinding step is not limited to the two steps of the first grinding step and the second grinding step, but may be one step or three or more steps, and the grinding step may be omitted if it is not necessary. Also, the concentration step and the liquid concentration adjustment step may or may not be performed.

[0057] [2. Low refractive index layer and method for manufacturing the same] The low refractive index layer of the present disclosure is characterized by being obtained by coating the dispersion of the present disclosure and drying it, as described above. The layer obtained by coating the dispersion of the present disclosure and drying it may be subjected to, for example, heating or light irradiation. By heating or light irradiation, for example, the particles of the condensate of the raw materials containing the alkoxysilane can be crosslinked together directly or via the crosslinking aid, thereby increasing the strength.

[0058] The low refractive index layer of this disclosure may be manufactured, for example, by coating the dispersion of this disclosure onto a substrate such as a film and drying it. The film may be, for example, a resin film. Generally, materials with relatively small thickness are called "films" and those with relatively large thickness are called "sheets" to distinguish them, but in this disclosure, there is no particular distinction between "films" and "sheets". The substrate is not particularly limited, and preferably, but is not limited to, thermoplastic resin substrates, glass substrates, inorganic substrates represented by silicon, plastics molded from thermosetting resins, semiconductor devices, carbon fiber materials represented by carbon nanotubes, etc.

[0059] The method for manufacturing the low refractive index layer of this disclosure is not particularly limited and may be used, for example, in a manner similar to that described in International Publication No. 2019 / 065999 or International Publication No. 2019 / 065803.

[0060] The low refractive index layer of this disclosure may be, for example, a void layer having voids. Alternatively, the low refractive index layer of this disclosure may be, for example, a porous material in which microporous particles are chemically bonded to each other.

[0061] The low refractive index layer of this disclosure may have a thickness of, for example, 500 nm or more, 700 nm or more, 800 nm or more, 1000 nm or more, or 2000 nm or more, or for example, 10000 nm or less, 8000 nm or less, 5000 nm or less, 4000 nm or less, or 3000 nm or less, or for example, 500 to 10000 nm, 700 to 8000 nm, 800 to 5000 nm, 1000 to 4000 nm, or 2000 to 3000 nm. The low refractive index layer of the present disclosure may have a porosity of, for example, 30 volume% or more, 35 volume% or more, 40 volume% or more, 45 volume% or more, or 50 volume% or more, for example, 90 volume% or less, 80 volume% or less, 70 volume% or less, or 60 volume% or less, for example, 30 to 90 volume%, 35 to 80 volume%, 40 to 70 volume%, or 50 to 60 volume%. The low refractive index layer of the present disclosure may have a refractive index of, for example, 1.05 or more, 1.10 or more, or 1.13 or more, for example, 1.35 or less, 1.30 or less, or 1.25 or less, for example, 1.05 to 1.35, 1.10 to 1.30, or 1.13 to 1.25.

[0062] In the low refractive index layer of this disclosure, the porosity can be measured by the following method.

[0063] <Method for Measuring Porosity> If the layer to be measured for porosity is a single layer containing only voids, the ratio (volume ratio) of the constituent material to air in the layer can be calculated using a standard method (for example, by measuring weight and volume and calculating density), and thus the porosity (volume %) can be calculated. Furthermore, since there is a correlation between refractive index and porosity, the porosity can also be calculated from the refractive index value of the layer, for example. Specifically, for example, the porosity can be calculated from the refractive index value measured with an ellipsometer using the Lorentz-Lorentz formula.

[0064] In this disclosure, the refractive index of the low refractive index layer is the refractive index value at a wavelength of 550 nm, measured and calculated by the method described below.

[0065] <Method for measuring refractive index> After forming a low refractive index layer on a glass light guide plate, a laser beam (λ = 407 nm) is incident from the glass light guide plate side using a prism coupler (manufactured by Metricon), and the refractive index at 407 nm is calculated from the measured total reflection angle. Furthermore, the measured refractive index at 407 nm is converted to the refractive index at 550 nm from the wavelength dispersion of the low refractive index layer alone, which is calculated separately using an ellipsometer (manufactured by J.A. Wollam), and this converted value is taken as the refractive index of the low refractive index layer.

[0066] The low refractive index layer of this disclosure preferably has a thickness variation of, for example, 20% or less, 18% or less, 16% or less, 15% or less, or 10% or less, and the lower limit is not particularly limited, but may be, for example, 0 or a value greater than 0. The thickness variation refers to the in-plane film thickness variation of the low refractive index layer when a low refractive index layer of 1.25 or less is formed by spin coating on a light guide plate with a diameter or short side of 20 cm or less made of glass or resin with a surface roughness Rz of 50 nm or less of the dispersion of this disclosure. In this disclosure, the in-plane film thickness variation of the low refractive index layer is an index obtained by comparing the standard deviation of the measured values ​​of the film thickness at five points in the plane with the average film thickness.

[0067] The applications of the low refractive index layer of this disclosure are not particularly limited, but for example, it can be used as a total reflection layer by taking advantage of its low refractive index.

[0068] [3. Optical members and optical devices] The optical members of the present disclosure are characterized by including the low refractive index layer of the present disclosure as described above. The optical members of the present disclosure may include or may not include components other than the low refractive index layer of the present disclosure.

[0069] The optical component of this disclosure may be, for example, a laminate in which a low refractive index layer of this disclosure is laminated on a substrate. The substrate is not particularly limited, but may be as described above.

[0070] The optical component of this disclosure may be, for example, a light guide plate with a low refractive index layer, wherein the low refractive index layer of this disclosure is laminated on a light guide plate. In this case, other layers such as adhesive layers may exist between the light guide plate and the low refractive index layer of this disclosure, but it is preferable that the low refractive index layer of this disclosure is laminated directly on the light guide plate without any other layers in between. In this case, for example, the low refractive index layer of this disclosure can be manufactured by coating the light guide plate with the dispersion of this disclosure and drying it using the method described above.

[0071] The optical components of this disclosure are not limited to light guide plates, but may also include, for example, polarizing plates, phase difference films, reflective polarizers, brightness-enhancing films, diffusion films, dye-containing layers, or layers or films having transparent and opaque optical functions.

[0072] The optical device (optical apparatus) of this disclosure is not particularly limited, but may be, for example, an image display device or an illumination device. Examples of image display devices include liquid crystal displays, organic EL (Electroluminescence) displays, microLED (Light Emitting Diode) displays, etc. Examples of illumination devices include organic EL lighting, etc.

[0073] Next, embodiments of the present disclosure will be described. However, the present disclosure is not limited to the following embodiments.

[0074] In the following reference examples, examples, and comparative examples, the number of parts (relative amount used) of each substance is in parts by mass (parts by weight) unless otherwise specified. In the following reference examples, examples, and comparative examples, the adhesive used is the adhesive (adhesive composition) described later. In the following reference examples, examples, and comparative examples, "adhesive layer" corresponds to "adhesive bonding layer." That is, in the following reference examples, examples, and comparative examples, "adhesive layer" and "adhesive bonding layer" are synonymous unless otherwise specified.

[0075] <Method for measuring the concentration of the coating solution> The total concentration of solids (components other than the dispersion medium) in the coating solution, or the concentration of particles of the condensate of the raw material containing alkoxysilane (by weight %), was calculated from the ratio of the total weight (mass) of the coating solution to the total weight (mass) of the solids in the coating solution or the weight (mass) of the particles of the condensate of the raw material containing alkoxysilane.

[0076] <Method for measuring the viscosity of the coating solution> The viscosity of the coating solution was measured at a measurement temperature of 25°C using an E-type viscometer with a 1° cone rotor.

[0077] <Method for measuring refractive index> The refractive index was measured using the method described above.

[0078] <Method for measuring particle size> The particle size D50 of the condensate of raw materials containing alkoxysilane was measured by the method described above. As mentioned above, D50 is also called the median diameter and is the particle size of the median of the particle distribution, corresponding to a cumulative frequency of 50%.

[0079] <Method for Measuring Film Thickness> The film thickness (thickness) and its variation of the low refractive index layer were measured as follows: The low refractive index layer formed on glass was measured at five in-plane points using a spectroscopic ellipsometer (manufactured by J.A. Woolam), and the mean value and standard deviation were calculated. The ratio of this standard deviation to the mean value was calculated and this value was defined as the variation.

[0080] <Method for Measuring Haze Value> A 100 mm x 100 mm laminate (void layer / glass substrate) was used as the measurement sample. The measurement sample was set in a spectroscopic haze meter (manufactured by Nippon Denshoku Industries Co., Ltd.: SH7000) and the haze value was measured. More specifically, the haze value was calculated by measuring the diffuse transmittance and total light transmittance, and using the following formula from these values, the measured haze value was taken as the value. Haze value (%) = [Diffuse transmittance (%) / Total light transmittance (%)] × 100 (%)

[0081] <Method for measuring the specific surface area of ​​particles> The specific surface area of ​​the particles was measured using the method described above.

[0082] <Method for measuring the pore volume of particles> The pore volume of the particles was measured using the method described above.

[0083] <Method for measuring the pore diameter of particles> The pore diameter of the particles was measured using the method described above.

[0084] [Reference Example 1: Production of Gel Grinding Solution for Low Refractive Index Layer Formation] A gel grinding solution (sol particle liquid) for low refractive index layer formation was produced as follows.

[0085] (1) Gelation of silicon compounds Mixture A was prepared by dissolving 9.5 kg of methyltrimethoxysilane (MTMS), a precursor of silicon compounds, in 22 kg of dimethyl sulfoxide (DMSO). 5 kg of 0.01 mol / L aqueous oxalic acid solution was added to mixture A, and the mixture was stirred at room temperature for 30 minutes to hydrolyze the MTMS and produce mixture B containing tris(hydroxy)methylsilane.

[0086] To 55 kg of DMSO, 3.8 kg of 28% by weight aqueous ammonia and 2 kg of pure water were added. Then, the above mixture B was added, and the mixture was stirred at room temperature for 15 minutes to gel tris(hydroxy)methylsilane, obtaining mixture C containing a gel-like silicon compound.

[0087] (2) Aging process The mixed liquid C containing the gel-like silicon compound prepared as described above was poured into a 30 cm x 30 cm x 5 cm stainless steel container and incubated at 40°C for 20 hours to perform the aging process.

[0088] (3) Grinding Process Next, isobutyl alcohol, which is the substitution solvent, was poured onto the gel synthesized in the stainless steel container. Then, the cutting blade of a cutting jig was slowly inserted into the gel from above, and the gel was cut into a rectangular parallelepiped measuring 1.5 cm × 2 cm × 5 cm. The cut gel was transferred to another container, and while being careful not to disturb the shape of the gel, isobutyl alcohol was added in an amount four times the volume of the gel. After standing for 6 hours, solvent substitution was performed four times, replacing the solvent. The gel (gel-like silicon compound) was ground using a continuous emulsification dispersion machine (Milder MDN304, manufactured by Taiheiyo Kiko Co., Ltd.) to obtain a coarse grinding liquid. Further grinding was performed using a high-pressure medialess grinding machine (Starburst HJP-25005, manufactured by Sugino Machine Co., Ltd.) under a pressure of 100 MPa. In this way, an isobutyl alcohol dispersion (gel grinding material-containing liquid) in which nanometer-sized particles (the pulverized gel) were dispersed was obtained.

[0089] [Example 1] IBA (isobutyl alcohol) was added to the gel pulverized liquid obtained in Reference Example 1 to adjust the concentration of particles of the condensate of the raw material containing alkoxysilane to 3.5% by weight. Next, nano-pulverization was performed on this gel pulverized liquid using Starburst (product name of Sugino Machine Co., Ltd.) under a high pressure of 150 MPa, adjusting the pulverization time so that the particle size D50 of the particles after pulverization was 190 nm, thereby obtaining a nano-pulverized liquid with a concentration of particles of the condensate of the raw material containing alkoxysilane at 3.5% by weight (first pulverization step). Next, the liquid was concentrated using Mitsubishi Dynafilter (DyF) (product name of Mitsubishi Chemical Machinery Ltd.) until the concentration of particles of the condensate of the raw material containing alkoxysilane reached 6% by weight (concentration step). Next, nano-pulverization was performed again using Starburst under a high pressure of 150 MPa, adjusting the pulverization time so that the particle size D50 of the particles after pulverization was 130 nm (second pulverization step). Subsequently, 0.24 g of bis(trimethoxysilyl)hexane, a crosslinking aid, and 0.24 g of the photobase catalyst WPBG-266 (Wako) were added to 100 g of the liquid, and then IBA (isobutyl alcohol) was added to adjust the total solid content concentration of the liquid to 4.2% by weight (the concentration of particles of the condensate of the raw materials containing alkoxysilane was 3.86% by weight), thereby producing the dispersion of the present disclosure. The dispersion was then coated by spin coating and dried, and then subjected to a pressure of 350 mJ / cm². ２ The low refractive index layer of this disclosure was produced by crosslinking the particles of the condensate of raw materials containing alkoxysilane by UV irradiation at 360 nm.

[0090] [Example 2] The dispersion and low refractive index layer of the disclosure were produced by the same procedure as in Example 1, except that the second grinding step was omitted and concentration adjustment and additive mixing were performed after the concentration step.

[0091] [Example 3] The dispersion and low refractive index layer of the present disclosure were produced by the same procedure as in Example 1, except that in the first grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 80 nm, in the second grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 50 nm, and thereafter the amount of IBA added was changed to adjust the total solid content concentration of the liquid to 9.5% by weight (the concentration of particles of the condensate of the raw materials containing alkoxysilane was 9.03% by weight).

[0092] [Example 4] The dispersion and low refractive index layer of the present disclosure were produced by the same procedure as in Example 1, except that in the first grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 80 nm, in the second grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 65 nm, and thereafter the amount of IBA added was changed to adjust the total solid content concentration of the liquid to 8.0% by weight (the concentration of particles of the condensate of the raw materials containing alkoxysilane was 7.73% by weight).

[0093] [Example 5] The dispersion and low refractive index layer of the present disclosure were produced by the same procedure as in Example 1, except that in the first grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 80 nm, in the second grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 52 nm, and thereafter the amount of IBA added was changed to adjust the total solid content concentration of the liquid to 9.5% by weight (the concentration of particles of the condensate of raw materials containing alkoxysilane was 9.03% by weight).

[0094] [Example 6] The dispersion and low refractive index layer of the present disclosure were produced by the same procedure as in Example 1, except that in the first grinding step, the grinding time was adjusted so that the particle size D50 of the particles after grinding was 120 nm, in the second grinding step, the grinding time was adjusted so that the particle size D50 of the particles after grinding was 100 nm, and thereafter, the amount of IBA added was changed to adjust the total solid content concentration of the liquid to 9.5% by weight (the concentration of particles of the condensate of the raw material containing alkoxysilane was 9.03% by weight).

[0095] [Example 7] The dispersion and low refractive index layer of the present disclosure were produced by the same procedure as in Example 1, except that in the first grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 80 nm, in the second grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 52 nm, and thereafter the amount of IBA added was changed to adjust the total solid content concentration of the liquid to 12% by weight (the concentration of particles of the condensate of the raw materials containing alkoxysilane was 11.1% by weight).

[0096] [Example 8] The dispersion and low refractive index layer of the present disclosure were produced by the same procedure as in Example 1, except that in the first grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 80 nm, in the second grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 52 nm, and thereafter the amount of IBA added was changed to adjust the total solid content concentration of the liquid to 16% by weight (the concentration of particles of the condensate of the raw materials containing alkoxysilane was 14.2% by weight).

[0097] [Example 9] The dispersion and low refractive index layer of the present disclosure were produced by the same procedure as in Example 1, except that in the first grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 80 nm, in the second grinding step the grinding time was adjusted so that the particle size D50 of the particles after grinding was 52 nm, and thereafter the amount of IBA added was changed to adjust the total solid content concentration of the liquid to 20% by weight (the concentration of particles of the condensate of the raw materials containing alkoxysilane was 17.1% by weight).

[0098] [Comparative Example 1] The dispersion and low refractive index layer of this comparative example were produced by the same procedure as described in Example 1, except that the second grinding step was carried out without the concentration step and the film was formed as is.

[0099] [Comparative Example 2] The same procedure as in Example 1 was followed up to the first grinding step, and then the concentration of the particles of the condensate of the raw material containing alkoxysilane was concentrated to 15.1% by weight in the concentration step. As a result, the viscosity of the liquid began to increase immediately after the concentration step, and the viscosity of the liquid was too high to form a low refractive index layer. In addition, particle aggregation progressed during the liquid concentration adjustment and additive mixing steps, and could not be controlled within the scope of this disclosure.

[0100] [Comparative Example 3] The same procedure as in Example 1 was followed up to the first grinding step, and then the concentration of the particles of the condensate of the raw material containing alkoxysilane was concentrated to 18.5% by weight in the concentration step. As a result, the viscosity of the liquid began to increase immediately after the concentration step, and the viscosity of the liquid was too high to form a low refractive index layer. In addition, particle aggregation progressed during the liquid concentration adjustment and additive mixing steps, and could not be controlled within the scope of this disclosure.

[0101] The optical properties and appearance of the film (low refractive index layer) of the low refractive index layers produced in each of the above examples and comparative examples were evaluated using the method described above. The evaluation results are summarized in Table 1 below. In Table 1 below, "coating solution" refers to the dispersion of the present disclosure produced in each of the above examples or the dispersion of the above comparative examples. "Concentration of coating solution" represents the total concentration of solids in the dispersion of the present disclosure produced in each of the above examples or the dispersion of the above comparative examples. "Particle concentration" represents the concentration of siloxane condensate particles in the dispersion of the present disclosure produced in each of the above examples or the dispersion of the above comparative examples. "Viscosity of coating solution" represents the total viscosity of solids in the dispersion of the present disclosure produced in each of the above examples or the dispersion of the above comparative examples. "Particle size D50 of coating solution" represents the particle size D50 of siloxane condensate particles in the dispersion of the present disclosure produced in each of the above examples or the dispersion of the above comparative examples. "Film refractive index" represents the refractive index of the low refractive index layer manufactured in each of the above examples and comparative examples. "Film thickness" represents the thickness of the low refractive index layer manufactured in each of the above examples and comparative examples. "Film thickness variation" represents the variation in the thickness of the low refractive index layer manufactured in each of the above examples and comparative examples. "Haze" represents the haze value of the low refractive index layer manufactured in each of the above examples and comparative examples.

[0102]

[0103] As shown in Table 1 above, the dispersions (coating solutions) of the present disclosure produced in Examples 1 to 9 all allowed for the production of low refractive index layers with sufficiently large film thicknesses and small variations in film thickness (in-plane film thickness uniformity was achieved). In contrast, the dispersion (coating solution) of Comparative Example 1 had too low a particle concentration, resulting in a small film thickness for the low refractive index layer. The dispersion (coating solution) of Comparative Example 2 had too high a viscosity of 5000 mPa·s, preventing the formation of a low refractive index layer. Furthermore, Comparative Example 3 had too high a particle concentration, causing it to gel and fail to form a dispersion (coating solution), thus preventing the formation of a low refractive index layer. In Examples 3 to 5, the small particle size D50 reduced haze, and the higher particle concentration compared to Examples 1 and 2 allowed for sufficient film thickness despite the small particle size D50, resulting in small variations in film thickness (in-plane film thickness uniformity was achieved). In Example 6, the specific surface area was increased and the pore diameter was reduced to lower the refractive index, but the film thickness was maintained and the variation in film thickness was also reduced (in-plane film thickness uniformity was achieved). In Examples 7 to 9, the variation in film thickness was further reduced by increasing the particle concentration (in-plane film thickness uniformity was further achieved).

[0104] Although the present disclosure has been described above with reference to embodiments and examples, the present disclosure is not limited to the embodiments and examples described above. Various modifications to the structure and details of the present disclosure are possible, as can be understood by those skilled in the art within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0105] This disclosure may also be presented, for example, as shown in the following appendix. However, the following appendix is ​​illustrative, and this disclosure is not limited to these forms.

[0106] (Note 1) A dispersion in which particles are dispersed in a dispersion medium, wherein the particles are condensates of raw materials containing alkoxysilane, the concentration of the particles in the dispersion is 3.5% by weight or more and less than 18.5% by weight, and the viscosity of the dispersion is 4 mPa·s or more and less than 5000 mPa·s. (Note 2) The dispersion according to Note 1, wherein the particle size D50 of the particles is 20 nm or more and 400 nm or less. (Note 3) The dispersion according to Note 1 or 2, wherein the concentration of the particles in the dispersion is 6.0% by weight or more and less than 18.5% by weight, the viscosity of the dispersion is 4 to 2000 mPa·s, and the particle size D50 of the particles is 20 to 120 nm. (Note 4) A dispersion in which solid components containing particles are dispersed in a dispersion medium, wherein the particles are condensates of raw materials containing alkoxysilane, the concentration of the solid components in the dispersion is 3.5 to 22% by weight, and the viscosity of the dispersion is 4 Pa·s or more and less than 5000 mPa·s. (Note 5) The dispersion according to Note 4, wherein the particle size D50 of the particles is 20 nm or more and 400 nm or less. (Note 6) The dispersion according to Note 4 or 5, wherein the concentration of the solid components in the dispersion is 6.0 to 22% by weight, the viscosity of the dispersion is 4 to 2000 mPa·s, and the particle size D50 of the particles is 20 to 120 nm. (Note 7) The dispersion according to any one of claims 1 to 6, wherein the particle size D50 of the particles is 20 nm or more and 400 nm or less. (Note 8) The specific surface area of ​​the particles is 350 to 1000 m ２A dispersion according to any one of the appendices 1 to 7, wherein the amount is / g. (Appendix 9) A dispersion according to any one of claims 1 to 8, wherein the pore diameter of the particles is 17 nm or less. (Appendix 10) A dispersion according to any one of the appendices 1 to 9, characterized in that the particles are pulverized condensate. (Appendix 11) A dispersion according to any one of the appendices 1 to 10, wherein the particles are condensate of a raw material containing an alkoxysilane having three or fewer functional groups. (Appendix 12) A dispersion set characterized by comprising the dispersion according to any one of the appendices 1 to 11 and a catalyst-containing liquid containing a catalyst for chemically bonding the particles of the dispersion. (Appendix 13) A dispersion set according to appendix 12, further characterized by comprising a crosslinking aid-containing liquid containing a crosslinking aid for indirectly bonding the particles together. (Appendix 14) A low refractive index layer characterized by being obtained by coating and drying the dispersion according to any one of the appendices 1 to 11 or the dispersion set according to appendix 12 or 13. (Note 15) An optical component characterized by including a low refractive index layer as described in Note 14. (Note 16) An optical device characterized by including an optical component as described in Note 15. (Note 17) A method for manufacturing a low refractive index layer, comprising the steps of coating a substrate with a dispersion liquid described in any of Notes 1 to 11 or a dispersion liquid set described in Note 12 or 13, and drying the coated dispersion liquid. (Note 18) A method for manufacturing an optical component including a low refractive index layer, characterized in that the low refractive index layer is manufactured by the manufacturing method described in Note 17. (Note 19) A method for manufacturing an optical device including an optical component, characterized in that the optical component is manufactured by the manufacturing method described in Note 18.

[0107] As described above, the present disclosure provides a dispersion, a dispersion set, a low refractive index layer, an optical component, an optical device, a method for manufacturing a low refractive index layer, a method for manufacturing an optical component, and a method for manufacturing an optical device, all of which enable the securing of film thickness and the realization of uniform in-plane film thickness of a low refractive index layer. The applications of the present disclosure are not particularly limited. For example, the optical device of the present disclosure is not particularly limited and includes image display devices, lighting devices, etc. Examples of the image display device include liquid crystal displays, organic EL displays, micro-LED displays, etc. Examples of the lighting device include organic EL lighting, etc.

[0108] This application claims priority based on PCT / JP2025 / 006117, filed on 21 February 2025, and incorporates all of its disclosures herein.

Claims

1. A dispersion in which particles are dispersed in a dispersion medium, wherein the particles are condensates of raw materials containing alkoxysilane, the concentration of the particles in the dispersion is 3.5% by weight or more and less than 18.5% by weight, and the viscosity of the dispersion is 4 mPa·s or more and less than 5000 mPa·s.

2. The dispersion according to claim 1, wherein the particle size D50 of the particles is 20 nm or more and 400 nm or less.

3. The specific surface area of ​​the particles is 350 to 1000 m². ２ The dispersion according to claim 1 or 2, wherein the amount is / g.

4. The dispersion according to any one of claims 1 to 3, wherein the pore diameter of the particles is 17 nm or less.

5. The dispersion according to any one of claims 1 to 4, wherein the concentration of the particles in the dispersion is 6.0% by weight or more and less than 18.5% by weight, the viscosity of the dispersion is 4 to 2000 mPa·s, and the particle size D50 of the particles is 20 to 120 nm.

6. The dispersion according to any one of claims 1 to 5, characterized in that the particles are pulverized material of the condensate.

7. The dispersion according to any one of claims 1 to 6, wherein the particles are a condensate of a raw material containing an alkoxysilane having three or fewer functional groups.

8. A dispersion set comprising a dispersion according to any one of claims 1 to 7, and a catalyst-containing liquid containing a catalyst for chemically binding the particles of the dispersion.

9. The dispersion set according to claim 8, further comprising a crosslinking aid-containing liquid containing a crosslinking aid for indirectly binding the particles together.

10. A low refractive index layer characterized by being obtained by coating and drying a dispersion liquid according to any one of claims 1 to 7 or a dispersion liquid set according to claim 8 or 9.

11. An optical member characterized by comprising the low refractive index layer described in claim 10.

12. An optical device characterized by including the optical member described in claim 11.

13. A method for producing a low refractive index layer, comprising the steps of: coating a substrate with a dispersion liquid according to any one of claims 1 to 7 or a dispersion liquid set according to claim 8 or 9; and drying the coated dispersion liquid.

14. A method for manufacturing an optical component including a low refractive index layer, characterized in that the low refractive index layer is manufactured by the manufacturing method described in claim 13.

15. A method for manufacturing an optical device including an optical component, characterized in that the optical component is manufactured by the manufacturing method described in claim 14.

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