WO2018142530A1 - Method for producing structure - Google Patents

Method for producing structure Download PDF

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Publication number
WO2018142530A1
WO2018142530A1 PCT/JP2017/003739 JP2017003739W WO2018142530A1 WO 2018142530 A1 WO2018142530 A1 WO 2018142530A1 JP 2017003739 W JP2017003739 W JP 2017003739W WO 2018142530 A1 WO2018142530 A1 WO 2018142530A1
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WO
WIPO (PCT)
Prior art keywords
airgel
layer
group
sol
mass
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Application number
PCT/JP2017/003739
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French (fr)
Japanese (ja)
Inventor
寛之 泉
竜也 牧野
智彦 小竹
雄太 赤須
Original Assignee
日立化成株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 日立化成株式会社 filed Critical 日立化成株式会社
Priority to PCT/JP2017/003739 priority Critical patent/WO2018142530A1/en
Priority to JP2018565157A priority patent/JP6911874B2/en
Publication of WO2018142530A1 publication Critical patent/WO2018142530A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/02—Processes for applying liquids or other fluent materials performed by spraying
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/24—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials for applying particular liquids or other fluent materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material

Definitions

  • silica airgel As an airgel, for example, silica airgel is known (for example, see Patent Document 1). Silica airgel is generally produced by a method using a supercritical drying method.
  • the problem of workability can be easily solved and the heat insulation can be improved.
  • the flexibility is improved, so that the aerogel is further prevented from falling off, and the structure including such an airgel layer has the flexibility of the main body. It becomes easy to bend according to.
  • the diameter of the sol droplet may be 0.1 to 1000 ⁇ m. According to such a sol, a thick airgel layer can be formed more easily, and cracks in the airgel layer are further suppressed.
  • the coating layer may contain a filler. Thereby, peeling and dropping of the airgel layer at the time of high temperature use are further suppressed.
  • FIG. 1 is a cross-sectional view schematically showing a structure obtained by the structure manufacturing method according to the present embodiment.
  • the structure (aerogel composite, airgel composite structure) 100 has an airgel layer 5 formed on an object 10 (hereinafter also referred to as “object”) that is an object for forming an airgel layer.
  • object an object for forming an airgel layer.
  • the structure 100 may have, for example, a structure in which the airgel layer 5 is integrally formed on the object 10. That is, the structure 100 may include the target object 10 and the airgel layer 5 integrally bonded to the target object 10.
  • the object 10 and the airgel layer 5 may be integrally fixed.
  • the airgel layer 5 is an airgel layer formed from a mist-like (mist-like) sol.
  • the object 10 is a support part that supports the airgel layer 5, for example.
  • the structure 100 according to the present embodiment is excellent in heat insulation and water repellency, is excellent in unique optical characteristics and electrical characteristics, and is suppressed from falling off the airgel.
  • the structure 100 is a structure including an airgel layer 5 disposed on at least a part (a part or the whole) of the surface 10a of the object 10, for example.
  • Such a structure 100 is considered to exhibit excellent heat insulating properties, water repellency, unique optical characteristics and electrical characteristics, and to prevent the airgel from falling off.
  • the surface 10a on which the airgel layer 5 is disposed may be a flat surface, a composite plane (combination of inclined surfaces), or a curved surface.
  • the object 10 may include a main body 3 and a covering layer 4 that covers at least part of the surface of the main body 3.
  • the airgel layer 5 is formed on at least the coating layer 4 so that the coating layer 4 becomes an intermediate layer.
  • FIG. 2 is a cross-sectional view schematically showing a structure obtained by the structure manufacturing method according to the present embodiment.
  • the structure (aerogel composite, airgel composite structure) 200 includes a main body 3 and a coating layer 4 that covers at least a part of the surface of the main body 3 so that the coating layer 4 is an intermediate layer. At least the airgel layer 5 is formed on the coating layer 4. That is, the object 10 may include the main body 3 and the coating layer 4 that covers at least a part of the surface of the main body 3.
  • the structure 200 may include the main body 3 and the airgel layer 5 that is integrally joined to the main body 3 via the coating layer 4 that is an intermediate layer.
  • the airgel layer 5 may be integrally joined to the main body part 3 via the coating layer 4 serving as an intermediate layer.
  • the main body 3, the coating layer 4, and the airgel layer 5 may be integrated.
  • the main body 3 is, for example, a support that supports the airgel layer 5.
  • the structure 200 according to the present embodiment is excellent in adhesiveness and adhesion between the main body 3 and the airgel layer 5, and can further suppress the peeling and dropping of the airgel layer 5.
  • the structure 200 is also excellent in the protection performance of the main body 3.
  • the structure 200 according to the present embodiment includes, for example, a coating layer (also referred to as “intermediate layer”) 4 disposed on at least a part (a part or the whole) of the surface 3a of the main body 3, and the main body of the coating layer 4
  • the structure includes an airgel layer 5 disposed on at least a part (a part or the whole) of the surface 4a opposite to the part 3.
  • the main body 3 and the airgel layer 5 are integrally fixed via a covering layer 4 serving as an intermediate layer.
  • the surface 3a on which the coating layer 4 is disposed may be a flat surface, a composite plane (a combination of inclined surfaces), or a curved surface.
  • the covering layer is not necessarily essential. That is, the target object that forms the airgel layer may be the main body.
  • the structure is a structure including an airgel layer disposed on at least a part (a part or the whole) of the surface of the main body, and the main body and the airgel layer are directly It has a contact structure.
  • the surface of the main body portion on which the airgel layer is disposed may be a flat surface, a composite plane (combination of inclined surfaces), or a curved surface.
  • the airgel layer 5 includes a hydrolyzable functional group or a silicon compound having a condensable functional group (silicon compound) and a hydrolysis product (hydrolyzable functional group) of the silicon compound having the hydrolyzable functional group.
  • a silicon compound (silicon) having a hydrolyzable functional group or a condensable functional group which may be formed from a sol containing at least one selected from the group consisting of hydrolyzed silicon compounds) Compound), and condensation of sol containing at least one selected from the group consisting of hydrolysis products of silicon compounds having hydrolyzable functional groups (silicon compounds in which hydrolyzable functional groups are hydrolyzed) It may be a layer composed of a dried product of a wet gel (a wet gel derived from the sol).
  • the sol comprises at least one selected from the group consisting of a hydrolyzable functional group or a silicon compound having a condensable functional group, and a hydrolysis product of the silicon compound having the hydrolyzable functional group. You may contain.
  • the airgel layer is such, both heat insulation and flexibility can be achieved at a high level, and the airgel can be prevented from dropping off.
  • the material constituting the main body examples include metal, ceramic, glass, resin, and composite materials thereof.
  • the main body may include at least one selected from the group consisting of metal, ceramic, glass, and resin.
  • a block shape, a sheet shape, a spherical shape, a fiber shape, or the like can be adopted depending on the purpose or material to be used.
  • the metal is not particularly limited, and examples include a single metal, a metal alloy, and a metal on which an oxide film is formed.
  • the metal include iron, copper, nickel, aluminum, zinc, titanium, chromium, cobalt, tin, gold, and silver.
  • simple metals such as titanium, gold and silver; iron and aluminum on which an oxide film is formed can be used as the metal.
  • the ceramic examples include oxides such as alumina, titania, zirconia, and magnesia; nitrides such as silicon nitride and aluminum nitride; carbides such as silicon carbide and boron carbide; and mixtures thereof.
  • Examples of the glass include quartz glass, soda glass, and borosilicate glass.
  • the resin examples include polyvinyl chloride, polyvinyl alcohol, polystyrene, polyethylene, polypropylene, polyacetal, polymethyl methacrylate, polycarbonate, polyamide, and polyurethane.
  • the main body there is no particular limitation on the shape of the main body, and it may have either a flat surface or a curved surface.
  • Examples of the shape of the main body include a plate shape, a cylindrical shape, a spherical shape, and a rod shape.
  • Examples of the cylindrical main body include piping.
  • the surface roughness of the main body may be 100 nm or more, or 500 nm or more from the viewpoint of obtaining a good anchor effect and further improving the adhesion of the airgel layer.
  • the object may include a coating layer.
  • the material constituting the coating layer include organic materials, inorganic materials, and organic-inorganic hybrid materials.
  • the organic material examples include urethane resin, polyester resin, acrylic resin, phenol resin, epoxy resin, polyimide, polyamideimide, polybenzimidazole, polyetheretherketone, silicone, and composite materials thereof.
  • the organic material includes, for example, at least one selected from the group consisting of urethane resin, polyester resin, acrylic resin, phenol resin, epoxy resin, polyimide, polyamideimide, polybenzimidazole, polyetheretherketone, and silicone. It may be.
  • the organic material is, for example, from a hydroxyl group, an amino group, a carboxyl group, an epoxy group, an isocyanate group, a mercapto group, a cyano group, an ester bond, a urethane bond, and an amide bond.
  • the inorganic material examples include glass, a single metal, a metal alloy, a metal on which an oxide film is formed, ceramic, silicon carbide, silicon nitride, and sodium silicate.
  • the inorganic material includes, for example, at least one selected from the group consisting of glass, simple metal, metal alloy, metal with an oxide film, ceramic, silicon carbide, silicon nitride, and sodium silicate. There may be.
  • Examples of the metal include titanium, chromium, aluminum, copper, and platinum.
  • Examples of the ceramic include alumina and zirconia.
  • the inorganic material may further contain a binder.
  • the binder include metal alkoxide and water glass.
  • organic-inorganic hybrid material examples include a composite material of the organic material and the inorganic material, an epoxy-silica hybrid material, and an acrylic-silica hybrid material.
  • the material constituting the coating layer may be an inorganic material or an organic-inorganic hybrid material from the viewpoint of further improving the heat resistance, and the difference in thermal expansion between the main body and the coating layer when used in a high temperature environment.
  • an organic-inorganic hybrid material may be used.
  • a material having a low elastic modulus can also be used as a material constituting the coating layer.
  • the coating layer may be, for example, a layer composed of ceramic (ceramic layer) and / or a layer composed of metal (metal layer).
  • the coating layer may contain a filler from the viewpoint of further improving the heat resistance, further suppressing cracks, and further suppressing separation and dropping of the airgel layer during high temperature use.
  • a filler from the viewpoint of further improving the heat resistance, further suppressing cracks, and further suppressing separation and dropping of the airgel layer during high temperature use.
  • the reason why the airgel layer is further prevented from peeling and falling off by containing the filler is, for example, that the thermal expansion coefficient of the coating layer is adjusted by containing the filler, and the main body, the coating layer, and the airgel at high temperatures. It is assumed that this is because the difference in thermal expansion coefficient generated between the layers is reduced.
  • the filler examples include inorganic fillers and organic fillers.
  • the filler may be an inorganic filler from the viewpoint of improving the heat resistance of the coating layer and further suppressing peeling and dropping under high temperature conditions, and a thermal cycle when repeatedly used in a high temperature environment. From the viewpoint of improving reliability, an organic filler may be used.
  • an inorganic filler from the viewpoint of improving the heat resistance of the coating layer and further suppressing peeling and dropping under high temperature conditions, and a thermal cycle when repeatedly used in a high temperature environment.
  • an organic filler may be used.
  • limiting in particular in the shape of a filler For example, a short fiber form, fine powder form, and a hollow form may be sufficient.
  • the material constituting the inorganic filler examples include silica, mica, talc, glass, calcium carbonate, quartz, metal hydrate, metal hydroxide, and composite materials thereof.
  • the inorganic filler may include at least one selected from the group consisting of silica, mica, talc, glass, calcium carbonate, quartz, metal hydrate, and metal hydroxide.
  • Examples of the metal hydrate include potassium aluminum sulfate 12 hydrate, magnesium nitrate hexahydrate, and magnesium sulfate heptahydrate.
  • Examples of the metal hydroxide include aluminum hydroxide and magnesium hydroxide.
  • the aluminum hydroxide may be boehmite type aluminum hydroxide.
  • the inorganic filler may contain silica, glass, or metal hydroxide, and the glass may be glass short fiber or hollow glass.
  • the metal hydroxide may be magnesium hydroxide or boehmite type aluminum hydroxide.
  • the material constituting the organic filler examples include phosphate ester, polyester, polystyrene, pulp, elastomer, and composite materials thereof.
  • the organic filler may include at least one selected from the group consisting of phosphate ester, polyester, polystyrene, pulp, and elastomer.
  • the pulp may be in the form of pulp floc.
  • the organic filler may contain an elastomer because the thermal expansion difference between the main body and the coating layer is relieved of stress and cracks are easily suppressed.
  • the elastomer examples include styrene elastomers, olefin elastomers, urethane elastomers, polybutadiene elastomers, fluorine elastomers, and silicone elastomers.
  • styrene elastomers examples include styrene elastomers, olefin elastomers, urethane elastomers, polybutadiene elastomers, fluorine elastomers, and silicone elastomers.
  • a fluorine-based elastomer or a silicone-based elastomer can be used as the elastomer.
  • the content of the filler contained in the coating layer may be 0.1% by volume or more based on the total volume of the coating layer from the viewpoint of further improving the heat resistance.
  • the content of the filler contained in the coating layer is based on the total volume of the coating layer from the viewpoint of improving workability when forming the coating layer and improving the adhesion between the main body and the airgel layer. 70 volume% or less, 50 volume% or less, 40 volume% or less, or 30 volume% or less. From these viewpoints, the content of the filler contained in the coating layer may be 0.1 to 70% by volume or 0.1 to 50% by volume with respect to the total volume of the coating layer. 0.1 to 40% by volume, or 0.1 to 30% by volume.
  • the coating layer may contain, for example, an adhesion improver, a flame retardant, and an antioxidant.
  • adhesion improver examples include urea compounds such as urea silane; and silane coupling agents.
  • Examples of the flame retardant include melamine cyanurate and bis (pentabromophenyl) ethane.
  • antioxidants examples include an antioxidant made of ceramic powder such as alumina and zirconia and an inorganic binder.
  • the thermal decomposition temperature of the coating layer may be 300 ° C. or higher from the viewpoint of further improving the heat resistance.
  • the thermal decomposition temperature of 300 ° C. or higher means that the material is heated at a rate of 10 ° C./temperature in a nitrogen atmosphere using a high-temperature differential thermothermal gravimetric measuring device TG / DTA7300 manufactured by SII Nanotechnology. When measured under the condition of minutes, it means that the temperature when the weight is reduced by 5% is 300 ° C. or higher.
  • the thickness of the coating layer is 0.01 ⁇ m or more from the viewpoint of reducing damage due to impact and the like, and improving the protection performance of the main body, and further improving the adhesion between the main body and the airgel layer. It may be 0.1 ⁇ m or more, or 1 ⁇ m or more. From the viewpoint of suppressing cracks during formation of the coating layer, the thickness of the coating layer may be 1000 ⁇ m or less, may be less than 1000 ⁇ m, or may be 500 ⁇ m or less. The thickness of the coating layer may be 100 ⁇ m or less from the viewpoint of suppressing cracks due to a difference in thermal expansion between the main body portion and the coating layer and improving the thermal cycle stability. From these viewpoints, the thickness of the coating layer may be 0.01 to 1000 ⁇ m, 0.01 to 500 ⁇ m, or 0.01 to 100 ⁇ m.
  • the coating layer having a low water absorption rate By using a coating layer having a low water absorption rate, it is possible to further reduce the chemical influence of water-soluble acidic or basic substances and inorganic salts on the main body. Specifically, for example, the chemical change (corrosion, modification, etc.) of the main body due to the influence of a sol coating solution described later can be further reduced. That is, it is difficult to be influenced by the conditions for forming the airgel layer and the composition of the sol coating solution, and the structure can be easily manufactured. From these viewpoints, the water absorption rate of the coating layer may be less than 5%, less than 4%, or less than 3%.
  • the water absorption rate of the coating layer is a change in mass when a test piece obtained by molding the constituent material of the coating layer into a size of 20 mm ⁇ 20 mm ⁇ 0.5 mm is left in a constant temperature and humidity chamber at 60 ° C. and 90% RH for 6 hours. Means rate.
  • the surface roughness (Ra) of the coating layer may be 200 nm or more, or 300 nm or more from the viewpoint of obtaining a good anchor effect between the coating layer and the airgel layer and further improving the adhesion of the airgel layer. It may be 500 nm or more.
  • the surface roughness of the coating layer can be adjusted by, for example, forming a coating layer on the main body and then subjecting the coating layer to polishing (polishing) or roughening (roughening).
  • the polishing process or the roughening process may be a mechanical process or a chemical process. Examples of processing methods include mechanical processing with abrasive grains such as slurry or abrasive; wet etching with acid or base, oxidizing agent or reducing agent; and dry etching with sulfur hexafluoride or carbon tetrafluoride. It is done.
  • the coating layer may be a single layer or a plurality of layers.
  • the airgel layer according to the present embodiment is made of airgel and is formed from a mist-like sol.
  • dry gel obtained by using supercritical drying method for wet gel is aerogel
  • dry gel obtained by drying under atmospheric pressure is xerogel
  • dry gel obtained by freeze-drying is cryogel and
  • the obtained low-density dried gel is referred to as “aerogel” regardless of the drying method of the wet gel.
  • “aerogel” is a gel in a broad sense, “Gel composed of a microporous solid in which the dispersed phase is a gas” (a gel composed of a microporous solid in which the dispersed phase is a gas).
  • the inside of the airgel has a network-like fine structure, and has a cluster structure in which airgel particles of about 2 to 20 nm (particles constituting the airgel) are combined. There are pores less than 100 nm between the skeletons formed by these clusters. Thereby, the airgel has a three-dimensionally fine porous structure.
  • the airgel in this embodiment is a silica airgel which has a silica as a main component, for example.
  • the silica airgel include so-called organic-inorganic hybrid silica airgel into which an organic group (such as a methyl group) or an organic chain is introduced.
  • the airgel layer may be a layer containing an airgel having a structure derived from polysiloxane.
  • the aerogel according to the present embodiment may have, for example, pores smaller than the mean free path of gas from the viewpoint of excellent heat insulation and a unique electrical characteristic.
  • the primary particle diameter of the airgel according to the present embodiment may be, for example, about several nm from the viewpoint of exhibiting unique optical characteristics.
  • the airgel according to the present embodiment includes a silicon compound having a hydrolyzable functional group or a condensable functional group (in the molecule) and a hydrolysis product of the silicon compound having the hydrolyzable functional group. It may be a dried product of a wet gel that is a condensate of a sol containing at least one selected from the group. That is, the airgel according to the present embodiment includes a hydrolyzable functional group or a silicon compound having a condensable functional group (in the molecule) and a hydrolysis product of the silicon compound having the hydrolyzable functional group.
  • the condensate may be obtained by a condensation reaction of a hydrolysis product obtained by hydrolysis of a silicon compound having a hydrolyzable functional group, and is not a functional group obtained by hydrolysis. It may be obtained by a condensation reaction of a silicon compound having a group.
  • the silicon compound may have at least one of a hydrolyzable functional group and a condensable functional group, and may have both a hydrolyzable functional group and a condensable functional group.
  • each airgel mentioned later is a group which consists of a hydrolysis product of the silicon compound which has a hydrolyzable functional group or a condensable functional group, and the said hydrolyzable functional group in this way. It may be a dried product of a wet gel that is a condensate of a sol containing at least one selected from the above (obtained by drying a wet gel produced from the sol).
  • such an airgel is considered to have excellent heat insulation and a very low refractive index. Therefore, for example, it is considered that it can be used for a heat insulating material, a light reflecting material, and the like.
  • Airgel according to the present embodiment (at least selected from the group consisting of hydrolyzable functional groups or silicon compounds having a condensable functional group, and hydrolysis products of silicon compounds having the hydrolyzable functional group) It is considered that an airgel formed from a sol containing one kind is unlikely to deteriorate in function due to water absorption.
  • the airgel layer contains at least one selected from the group consisting of a hydrolyzable functional group or a silicon compound having a condensable functional group, and a hydrolysis product of the silicon compound having the hydrolyzable functional group. It may be a layer composed of a dried product of a wet gel that is a condensate of the sol. That is, the airgel layer is at least one selected from the group consisting of a hydrolyzable functional group or a silicon compound having a condensable functional group, and a hydrolysis product of the silicon compound having the hydrolyzable functional group. It may be composed of a layer formed by drying a wet gel produced from a sol containing.
  • the airgel according to the present embodiment can contain polysiloxane having a main chain including a siloxane bond (Si—O—Si).
  • the airgel can have the following M unit, D unit, T unit or Q unit as a structural unit.
  • R represents an atom (hydrogen atom or the like) or an atomic group (alkyl group or the like) bonded to a silicon atom.
  • the M unit is a unit composed of a monovalent group in which a silicon atom is bonded to one oxygen atom.
  • the D unit is a unit composed of a divalent group in which a silicon atom is bonded to two oxygen atoms.
  • the T unit is a unit composed of a trivalent group in which a silicon atom is bonded to three oxygen atoms.
  • the Q unit is a unit composed of a tetravalent group in which a silicon atom is bonded to four oxygen atoms. Information on the content of these units can be obtained by Si-NMR.
  • the airgel according to the present embodiment may contain silsesquioxane.
  • Silsesquioxane is a polysiloxane having the above T unit as a structural unit, and has a composition formula: (RSiO 1.5 ) n .
  • Silsesquioxane can have various skeletal structures such as a cage type, a ladder type, and a random type.
  • Examples of the hydrolyzable functional group include an alkoxy group.
  • Examples of the condensable functional group include a hydroxyl group, a silanol group, a carboxyl group, and a phenolic hydroxyl group.
  • the hydroxyl group may be contained in a hydroxyl group-containing group such as a hydroxyalkyl group.
  • Each of the hydrolyzable functional group and the condensable functional group may be used alone or in admixture of two or more.
  • the silicon compound can include a silicon compound having an alkoxy group as a hydrolyzable functional group, and can also include a silicon compound having a hydroxyalkyl group as a condensable functional group.
  • the silicon compound can have at least one selected from the group consisting of an alkoxy group, a silanol group, a hydroxyalkyl group and a polyether group from the viewpoint of further improving the flexibility of the airgel.
  • the silicon compound can have at least one selected from the group consisting of an alkoxy group and a hydroxyalkyl group from the viewpoint of improving the compatibility of the sol.
  • the number of carbon atoms of the alkoxy group and the hydroxyalkyl group can be 1 to 6, and the viewpoint of further improving the flexibility of the airgel 2 to 4.
  • the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group.
  • the hydroxyalkyl group include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
  • Examples of the airgel according to the present embodiment include the following modes. By adopting these aspects, it becomes easy to obtain an airgel excellent in water repellency and flexibility. By employing each aspect, an airgel having water repellency and flexibility according to each aspect can be obtained.
  • the airgel according to the present embodiment includes a polysiloxane compound having a hydrolyzable functional group or a condensable functional group (in the molecule), and a hydrolysis product of the polysiloxane compound having the hydrolyzable functional group.
  • a polysiloxane compound having a hydrolyzable functional group or a condensable functional group (in the molecule) and a hydrolysis product of the polysiloxane compound having the hydrolyzable functional group.
  • Wet which is a condensate of sol containing at least one compound selected from the group consisting of (the hydrolyzable functional group hydrolyzed polysiloxane compound) (hereinafter sometimes referred to as “polysiloxane compound group”) It may be a dried gel.
  • the airgel according to the present embodiment includes a hydrolyzable functional group or a polysiloxane compound having a condensable functional group (in the molecule) and hydrolysis of the polysiloxane compound having the hydrolyzable functional group. It may be obtained by drying a wet gel produced from a sol containing at least one selected from the group consisting of products. That is, the airgel layer is composed of a polysiloxane compound having a hydrolyzable functional group or a condensable functional group (in the molecule) and a hydrolysis product of the polysiloxane compound having the hydrolyzable functional group. It may be formed from a sol containing at least one selected from the group.
  • each airgel mentioned later is also from the hydrolysis product of the polysiloxane compound which has a hydrolyzable functional group or a condensable functional group, and the polysiloxane compound which has the said hydrolyzable functional group in this way.
  • It may be a wet gel dried product (obtained by drying a wet gel generated from the sol), which is a condensate of a sol containing at least one selected from the group.
  • the airgel layer is at least one selected from the group consisting of a hydrolyzable functional group or a polysiloxane compound having a condensable functional group, and a hydrolysis product of the polysiloxane compound having a hydrolyzable functional group. It may be a layer composed of a dried product of a wet gel that is a condensate of sol containing That is, the airgel layer is selected from the group consisting of a hydrolyzable functional group or a polysiloxane compound having a condensable functional group, and a hydrolysis product of the polysiloxane compound having a hydrolyzable functional group. You may be comprised by the layer formed by drying the wet gel produced
  • a polysiloxane compound having a hydrolyzable functional group or a condensable functional group is a reactive group different from the hydrolyzable functional group and the condensable functional group (hydrolyzable functional group and condensable functional group). May further have a functional group that does not fall under.
  • the reactive group is not particularly limited, and examples thereof include an epoxy group, a mercapto group, a glycidoxy group, a vinyl group, an acryloyl group, a methacryloyl group, and an amino group.
  • the epoxy group may be contained in an epoxy group-containing group such as a glycidoxy group. You may use the polysiloxane compound which has the said reactive group individually or in mixture of 2 or more types.
  • Examples of the polysiloxane compound having a hydroxyalkyl group include compounds having a structure represented by the following general formula (A).
  • R 1a represents a hydroxyalkyl group
  • R 2a represents an alkylene group
  • R 3a and R 4a each independently represents an alkyl group or an aryl group
  • n represents an integer of 1 to 50.
  • examples of the aryl group include a phenyl group and a substituted phenyl group.
  • the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, and a cyano group.
  • two R 1a s may be the same or different, and similarly, two R 2a s may be the same or different.
  • two or more R 3a s may be the same or different, and similarly, two or more R 4a s may be the same or different.
  • examples of R 1a include a hydroxyalkyl group having 1 to 6 carbon atoms, and specific examples include a hydroxyethyl group and a hydroxypropyl group.
  • examples of R 2a include an alkylene group having 1 to 6 carbon atoms, and specific examples include an ethylene group and a propylene group.
  • R 3a and R 4a may each independently be an alkyl group having 1 to 6 carbon atoms or a phenyl group.
  • the alkyl group may be a methyl group.
  • n may be 2 to 30, or 5 to 20.
  • polysiloxane compound having the structure represented by the general formula (A) commercially available products can be used.
  • compounds such as X-22-160AS, KF-6001, KF-6002, KF-6003 and the like All of which are manufactured by Shin-Etsu Chemical Co., Ltd.
  • compounds such as XF42-B0970, Fluid OFOH 702-4% all manufactured by Momentive.
  • alkoxy group examples include a methoxy group and an ethoxy group.
  • R 4b and R 5b may each independently be an alkyl group having 1 to 6 carbon atoms or a phenyl group.
  • the alkyl group may be a methyl group.
  • m may be 2 to 30, or 5 to 20.
  • the polysiloxane compound having an alkoxy group may exist as a hydrolysis product in the sol.
  • the polysiloxane compound having an alkoxy group and the hydrolysis product are It may be mixed.
  • all of the alkoxy groups in the molecule may be hydrolyzed or partially hydrolyzed.
  • the total content of the decomposition products may be 1 part by mass or 3 parts by mass or more with respect to 100 parts by mass of the total amount of sol, from the viewpoint of further easily obtaining good reactivity. Alternatively, it may be 4 parts by mass or more, 5 parts by mass or more, 7 parts by mass or more, or 10 parts by mass or more.
  • the content of the polysiloxane compound group may be 50 parts by mass or less, or 30 parts by mass or less with respect to 100 parts by mass of the total amount of sol, from the viewpoint of further easily obtaining good compatibility. 15 parts by mass or less. From these viewpoints, the content of the polysiloxane compound group may be 1 to 50 parts by mass, 3 to 50 parts by mass, or 4 to 50 parts by mass based on 100 parts by mass of the sol. Part, 5 to 50 parts by weight, 7 to 30 parts by weight, 10 to 30 parts by weight, or 10 to 15 parts by weight. .
  • bistrimethoxysilylmethane, bistrimethoxysilylethane, bistrimethoxysilylhexane, bistrimethoxysilyloctane or the like which is a silicon compound having more than three hydrolyzable functional groups at the molecular terminals may be used. it can.
  • the ratio of the content of the polysiloxane compound group to the content of the silicon compound group may be 1: 0.5 to 1: 5. It may be 1: 0.5 to 1: 4, may be 1: 1 to 1: 2, may be 1: 2 to 1: 4, and may be 1: 3 to 1: 4. It may be.
  • the airgel according to the present embodiment can have a structure represented by the following general formula (1).
  • the airgel which concerns on this embodiment can have a structure represented by the following general formula (1a) as a structure containing the structure represented by Formula (1).
  • the structures represented by the formulas (1) and (1a) can be introduced into the skeleton of the airgel.
  • R 1 and R 2 may each independently be an alkyl group having 1 to 6 carbon atoms or a phenyl group.
  • the alkyl group may be a methyl group.
  • R 3 and R 4 may each independently be an alkylene group having 1 to 6 carbon atoms.
  • the alkylene group may be an ethylene group or a propylene group.
  • p can be 2 to 30, and can be 5 to 20.
  • the airgel which concerns on this embodiment is an airgel which has a ladder type structure provided with a support
  • a ladder structure By introducing such a ladder structure into the airgel skeleton, heat resistance and mechanical strength can be easily improved.
  • the polysiloxane compound having the structure represented by the general formula (B) a ladder structure including a bridge portion having the structure represented by the general formula (2) is introduced into the skeleton of the airgel. be able to.
  • the “ladder structure” is a structure having two struts and bridges connecting the struts (a structure having a so-called “ladder” form). ).
  • the airgel skeleton may have a ladder structure, but the airgel may partially have a ladder structure.
  • R 5 and R 6 each independently represents an alkyl group or an aryl group, and b represents an integer of 1 to 50.
  • examples of the aryl group include a phenyl group and a substituted phenyl group.
  • examples of the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, and a cyano group.
  • b is an integer of 2 or more
  • two or more R 5 s may be the same or different, and similarly, two or more R 6 s are the same. Or different.
  • the airgel according to the present embodiment may contain silica particles from the viewpoint of further toughening the airgel layer and further achieving excellent heat insulation and flexibility.
  • the sol that gives the airgel may further contain silica particles. That is, the airgel according to the present embodiment may be a dried product of a wet gel that is a condensate of a sol containing silica particles (obtained by drying a wet gel generated from the sol).
  • the airgel layer may be a layer composed of a dried product of a wet gel that is a condensate of a sol containing silica particles.
  • the airgel layer may be composed of a layer obtained by drying a wet gel generated from a sol containing silica particles.
  • the shape of the silica particles is not particularly limited, and examples thereof include a spherical shape, a cage shape, and an association type. Among these, by using spherical particles as silica particles, it becomes easy to suppress aggregation in the sol.
  • the average primary particle diameter of the silica particles may be 1 nm or more, or 5 nm or more, from the viewpoint that it is easy to impart an appropriate strength and flexibility to the airgel, and an airgel excellent in shrinkage resistance during drying is easily obtained. It may be 10 nm or more, or 20 nm or more.
  • the average particle diameter of the silica particles can be measured from the raw material.
  • the biaxial average primary particle diameter is calculated as follows from the result of observing 20 arbitrary particles by SEM. That is, when colloidal silica particles having a solid content concentration of 5 to 40% by mass, which are usually dispersed in water, are taken as an example, a chip obtained by cutting a wafer with a patterned wiring into 2 cm squares is dispersed in a colloidal silica particle dispersion. After soaking for 30 seconds, the chip is rinsed with pure water for about 30 seconds and blown with nitrogen.
  • the chip is placed on a sample stage for SEM observation, an acceleration voltage of 10 kV is applied, the silica particles are observed at a magnification of 100,000, and an image is taken.
  • 20 silica particles are arbitrarily selected from the obtained image, and the average of the particle diameters of these particles is defined as the average particle diameter.
  • a rectangle (circumscribed rectangle L) circumscribing the silica particles P and arranged so that the long side is the longest is led.
  • the long side of the circumscribed rectangle L is X
  • the short side is Y
  • the biaxial average primary particle diameter is calculated as (X + Y) / 2, and is defined as the particle diameter of the particle.
  • the content of the silica particles contained in the sol is 1 mass with respect to 100 mass parts of the total amount of the sol from the viewpoint of easily imparting an appropriate strength to the airgel and easily obtaining an airgel excellent in shrinkage resistance during drying. Or 4 parts by mass or more.
  • the content of the silica particles contained in the sol is 20 parts by mass or less with respect to 100 parts by mass of the total amount of the sol, from the viewpoint of easily suppressing the solid heat conduction of the silica particles and easily obtaining an airgel excellent in heat insulation. It may be 15 parts by mass or less, 12 parts by mass or less, 10 parts by mass or less, or 8 parts by mass or less.
  • the content of the silica particles contained in the sol may be 1 to 20 parts by mass, 4 to 15 parts by mass, or 4 to 4 parts by mass with respect to 100 parts by mass of the total amount of the sol. It may be 12 parts by mass, 4 to 10 parts by mass, or 4 to 8 parts by mass.
  • R 9 represents an alkyl group.
  • alkyl group examples include alkyl groups having 1 to 6 carbon atoms, and specific examples include a methyl group.
  • the airgel according to the present embodiment can have a structure represented by the following general formula (5).
  • the airgel which concerns on this embodiment can have a structure represented by following General formula (5) while containing a silica particle.
  • the airgel according to the present embodiment can have a structure represented by the following general formula (6).
  • the airgel which concerns on this embodiment can have a structure represented by following General formula (6) while containing a silica particle.
  • the airgel layer forming step may be, for example, a step of forming the airgel layer from the sol layer after forming the sol layer from the mist in the form of mist.
  • a coating layer formation process is a process of making the composition for coating layer formation contact the base material used as a main-body part, for example, and forming a coating layer on a main-body part. Specifically, for example, the composition for forming a coating layer is brought into contact with the substrate, and if necessary, the coating layer is formed on the surface of the substrate by heating and drying.
  • the composition for forming a coating layer may be a liquid composition such as a primer solution or a sheet-like composition such as an adhesive sheet.
  • the contact method is appropriately selected depending on the type of the coating layer forming composition, the thickness of the coating layer, or the shape of the substrate.
  • the composition for forming a coating layer is a sheet-like composition
  • a method of laminating on a substrate can be used
  • the composition for forming a coating layer is a liquid composition, for example, dip coating Spray coating, spin coating, roll coating, etc. can be used.
  • heat treatment may be performed from the viewpoint of drying and fixing the composition for forming the coating layer, and washing and / or drying from the viewpoint of removing impurities and improving the adhesion of the coating layer. May be performed. Further, for the purpose of adjusting the surface roughness of the coating layer, the surface of the coating layer may be subjected to polishing treatment and / or roughening treatment.
  • a silicon compound (if necessary, further silica particles) and a solvent are mixed and a hydrolysis reaction is performed, and then a sol-gel reaction is performed to obtain a semi-gelled sol coating liquid.
  • an acid catalyst may be further added to the solvent in order to promote the hydrolysis reaction.
  • a surfactant, a thermohydrolyzable compound, or the like can be added to the solvent.
  • a base catalyst may be added to promote the gelation reaction.
  • the boiling point of the solvent may be less than 200 ° C., 170 ° C. or less, or 150 ° C. or less from the viewpoint of obtaining good coatability in the contact step. That is, the sol may contain a solvent having a boiling point of less than 200 ° C., may contain a solvent having a boiling point of 170 ° C. or less, and may contain a solvent having a boiling point of 150 ° C. or less. According to the sol containing such a solvent, a thick airgel layer can be formed more easily, and cracks in the airgel layer are further suppressed.
  • the solvent may have a high surface tension from the viewpoint of improving the coating film formability and easy control of the film thickness.
  • the solvent may have a low volatility from the viewpoint of suppressing changes in the sol viscosity and resin content and improving storage stability.
  • Examples of the solvent that satisfies these characteristics include water or a mixed solution of water and alcohol.
  • Examples of the alcohol include methanol, ethanol, n-propanol, 2-propanol, n-butanol, 2-butanol and t-butanol. Among these, water may be used because it has a high surface tension and low volatility.
  • the acid catalyst examples include hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid, hypophosphorous acid, bromic acid, chloric acid, chlorous acid, hypochlorous acid, and other inorganic acids; Acid phosphates such as aluminum phosphate, acid magnesium phosphate, acid zinc phosphate; organics such as formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, citric acid, malic acid, adipic acid, azelaic acid Carboxylic acid is mentioned.
  • an organic carboxylic acid can be used from the viewpoint of further improving the water resistance of the resulting structure.
  • acetic acid, formic acid, propionic acid, oxalic acid and malonic acid are used. May be acetic acid. You may use an acid catalyst individually or in mixture of 2 or more types.
  • a nonionic surfactant As the surfactant, a nonionic surfactant, an ionic surfactant, or the like can be used. You may use surfactant individually or in mixture of 2 or more types.
  • a cationic surfactant As the ionic surfactant, a cationic surfactant, an anionic surfactant, an amphoteric surfactant or the like can be used, and a cationic surfactant or an anionic surfactant may be used.
  • the cationic surfactant include cetyltrimethylammonium bromide (CTAB) and cetyltrimethylammonium chloride.
  • CTAB cetyltrimethylammonium bromide
  • anionic surfactant examples include sodium dodecyl sulfonate.
  • amphoteric surfactants include amino acid surfactants, betaine surfactants, and amine oxide surfactants.
  • amino acid surfactants include acyl glutamic acid.
  • betaine surfactants include lauryldimethylaminoacetic acid betaine and stearyldimethylaminoacetic acid betaine.
  • the amine oxide surfactant include lauryl dimethylamine oxide.
  • surfactants are thought to have the effect of reducing phase separation by reducing the difference in chemical affinity between the solvent in the reaction system and the growing siloxane polymer in the contacting step. .
  • the addition amount of the surfactant depends on the type of the surfactant or the type and amount of the silicon compound.
  • the amount of the surfactant may be 1 to 100 parts by mass with respect to 100 parts by mass of the total amount of the silicon compound. It may be 5 to 60 parts by mass.
  • thermohydrolyzable compound generates a base catalyst by thermal hydrolysis to make the reaction solution basic and promote the sol-gel reaction.
  • the thermohydrolyzable compound is not particularly limited as long as it can make the reaction solution basic after hydrolysis.
  • urea include acid amides such as methylacetamide and N, N-dimethylacetamide; and cyclic nitrogen compounds such as hexamethylenetetramine.
  • urea is particularly easy to obtain the above-mentioned promoting effect.
  • the amount of the thermally hydrolyzable compound added is not particularly limited as long as it is an amount that can sufficiently promote the sol-gel reaction.
  • the amount of the thermally hydrolyzable compound (urea or the like) added may be 1 to 200 parts by mass or 2 to 150 parts by mass with respect to 100 parts by mass of the total amount of the silicon compound.
  • the addition amount of the thermohydrolyzable compound (urea or the like) is 1 part by mass or more, good reactivity can be further easily obtained, and when it is 200 parts by mass or less, the precipitation of crystals and the gel density are reduced. It becomes easy to suppress the decrease.
  • the hydrolysis in the sol production step depends on the types and amounts of silicon compound, silica particles, acid catalyst, surfactant, etc. in the mixed solution, but for example, 10 minutes to 20-60 ° C. in a temperature environment.
  • the reaction may be performed for 24 hours, or in a temperature environment of 50 to 60 ° C. for 5 minutes to 8 hours.
  • the hydrolyzable functional group in a silicon compound is fully hydrolyzed, and the hydrolysis product of a silicon compound can be obtained more reliably.
  • the temperature environment of the sol generation step may be adjusted to a temperature that suppresses hydrolysis of the thermohydrolyzable compound and suppresses gelation of the sol.
  • the temperature at this time may be any temperature as long as the hydrolysis of the thermally hydrolyzable compound can be suppressed.
  • the temperature environment in the sol production step (for example, the temperature environment when urea is used as the thermohydrolyzable compound) may be 0 to 40 ° C. or 10 to 30 ° C.
  • Base catalysts include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and cesium hydroxide; ammonium compounds such as ammonium hydroxide, ammonium fluoride, ammonium chloride, and ammonium bromide; sodium metaphosphate Basic sodium phosphates such as sodium pyrophosphate and sodium polyphosphate; allylamine, diallylamine, triallylamine, isopropylamine, diisopropylamine, ethylamine, diethylamine, triethylamine, 2-ethylhexylamine, 3-ethoxypropylamine, diisobutylamine, 3- (diethylamino) propylamine, di-2-ethylhexylamine, 3- (dibutylamino) propylamine, tetramethylethylenediamine, t-butylamine aliphatic amines such as sec-butylamine, propylamine, 3- (methyl
  • ammonium hydroxide (ammonia water) can be used from the viewpoint of high volatility and hardly remaining in the airgel layer after drying, and from the viewpoint of not impairing water resistance and economical efficiency.
  • the dehydration condensation reaction and / or dealcoholization condensation reaction of the silicon compound (polysiloxane compound group and silicon compound group) and silica particles in the sol can be promoted, and the gelation of the sol Furthermore, it can be performed in a short time.
  • ammonia is highly volatile and hardly remains in the structure. Therefore, by using ammonia as the base catalyst, a structure having further excellent water resistance can be obtained.
  • the addition amount of the base catalyst may be 0.5 to 5 parts by mass or 1 to 4 parts by mass with respect to 100 parts by mass of the total amount of silicon compounds (polysiloxane compound group and silicon compound group). .
  • the addition amount of the base catalyst is 0.5 parts by mass or more, gelation can be performed in a shorter time, and when it is 5 parts by mass or less, the water repellency is improved.
  • the sol-gel reaction in the sol production step can obtain a sol in a semi-gelled state for the purpose of obtaining good coating properties in the contact step.
  • This reaction can be performed in an airtight container so that a solvent and a base catalyst may not volatilize.
  • the gelation temperature depends on the type and amount of the silicon compound, silica particles, acid catalyst, surfactant, base catalyst and the like in the sol, but may be 30 to 90 ° C. or 40 to 80 ° C. There may be. When the gelation temperature is 30 ° C. or higher, gelation can be performed in a shorter time. When the gelation temperature is 90 ° C. or less, rapid gelation can be suppressed.
  • the sol-gel reaction time varies depending on the gelation temperature
  • the gelation time may be shortened as compared with a sol applied to a conventional aerogel. it can.
  • the reason for this is presumed that the hydrolyzable functional group or the condensable functional group of the silicon compound in the sol forms hydrogen bonds and / or chemical bonds with the silanol groups of the silica particles.
  • the gelation time may be 10 to 360 minutes or 20 to 180 minutes. When the gelation time is 10 minutes or longer, the viscosity of the sol is improved, and good coating properties are easily obtained in the contact process. It becomes easy to obtain adhesiveness with a part or a coating layer.
  • the sol coating liquid (semi-gelled sol coating liquid or the like) obtained in the sol generation step is brought into contact with the main body or the coating layer in the form of a mist to produce a structure (coating). Construction process).
  • the sol coating liquid is brought into contact with the main body part or the coating layer in the form of a mist, and the sol coating liquid is gelled by heating and drying as necessary to form the airgel layer of the main body part or the coating layer. Form on the surface.
  • the airgel layer is desirably in a state in which an adhesive force with the main body portion or the coating layer is ensured.
  • the contact method is not particularly limited as long as the sol can be contacted (applied) to the main body or the layer in a mist form, and examples thereof include spray coating. According to this method, since the mist generated by spraying only needs to reach the surface to be coated, for example, an airgel layer can be formed also on the inner surface of a cylindrical main body such as a pipe. .
  • sprays used for spray coating include air spray that mists are applied by applying compressed gas, and airless sprays that apply mist by applying pressure to the sol and spray mist from the spray gun.
  • a liquid electrostatic spray that efficiently attaches a mist to an adherend by applying a static voltage can be used.
  • the coating method is not limited, and a suitable method can be selected according to physical properties such as the size, shape, and elastic modulus of the main body or the coating layer.
  • the pressure of the gas used can be adjusted according to the specifications of the air gun and air brush used, for example.
  • the pressure is not particularly limited, but may be, for example, less than 0.5 MPa.
  • the thickness of the airgel layer formed in the contacting step can be adjusted by, for example, the pressure of the gas used for spraying, the coating amount of the sol, the viscosity of the sol, the distance between the spray and the main body, and the coating time.
  • the thickness of the airgel layer may be adjusted by the coating time from the viewpoint of workability. In this case, for example, a calibration curve indicating the relationship between the coating time and the thickness of the semi-cured gel or the thickness of the airgel layer may be created, and thereby the thickness may be controlled.
  • the diameter of the mist droplets of the sol may be 0.1 ⁇ m or more, from the viewpoint of easily forming a thick airgel layer and further suppressing cracking of the airgel layer, and may be 0.3 ⁇ m or more. It may be 0.5 ⁇ m or more. From the same viewpoint, the diameter of the sol droplet may be 1000 ⁇ m or less, 800 ⁇ m or less, or 500 ⁇ m or less. From these viewpoints, the diameter of the sol droplet may be 0.1 to 1000 ⁇ m, 0.3 to 800 ⁇ m, or 0.5 to 500 ⁇ m. When the diameter of the droplet is in such a range, it is easy to form a thick airgel layer and the crack of the airgel layer can be further suppressed. For example, a droplet having such a size has a sufficient surface area. Since it is large, it is assumed that the solvent in the sol evaporates in a short time after adhering to the main body or the coating layer, and the sol contracts accordingly.
  • the non-coating part is masked with a tape or the like, and then the sol is applied to the coating part. May be contacted.
  • the mask When masking is applied, from the viewpoint of reducing airgel loss and peeling at the boundary between the coated and non-coated areas, for example, after spray coating, the mask is removed at a semi-cured gel-like timing. May be.
  • these conditions are such that the moisture content of the airgel layer after heating and drying is, for example, 10% by mass from the viewpoint of easily obtaining adhesion between the airgel layer and the main body portion or the coating layer.
  • the conditions may be as described above, or the conditions may be 50% by mass or more.
  • the heating and drying temperature varies depending on conditions such as the amount of water in the sol coating liquid, the amount of the organic solvent, the boiling point of the organic solvent, etc., from the viewpoint of shortening the gelation time, for example, may be 50 ° C. It may be 60 ° C. or higher.
  • the heating and drying temperature may be, for example, 150 ° C. or less or 120 ° C. or less from the viewpoint of easily obtaining adhesion between the airgel layer and the main body portion or the coating layer. From these viewpoints, the heating and drying temperature may be, for example, 50 to 150 ° C. or 60 to 120 ° C.
  • the heating and drying time varies depending on the heating and drying temperature, but may be, for example, 0.2 minutes or more, or 0.5 minutes or more from the viewpoint of ease of forming the airgel layer.
  • the heating and drying time may be, for example, 10 minutes or less or 8 minutes or less from the viewpoint of easily obtaining the adhesion between the airgel layer and the main body portion or the coating layer. From these viewpoints, the heating and drying time may be, for example, 0.2 to 10 minutes or 0.5 to 8 minutes.
  • suitable conditions can be appropriately set by conducting a simple experiment in advance.
  • coating and drying may be repeated a plurality of times. By repeating the coating and drying, it is easy to adjust the moisture content of the airgel layer after heating and drying, and the film can be easily thickened.
  • the aging step is a step of aging the structure obtained by the contact step by heating.
  • the moisture content of the airgel layer after aging may be 10% by mass or more, or 50% by mass or more from the viewpoint of suppressing a decrease in adhesiveness between the airgel layer and the main body portion or the coating layer. May be.
  • the aging method is not particularly limited, and examples thereof include a method of aging the structure in a sealed atmosphere, and a method of aging using a constant temperature and humidity bath that can suppress a decrease in moisture content due to heating.
  • the aging temperature may be, for example, 40 to 90 ° C. or 50 to 80 ° C.
  • the aging temperature is 40 ° C. or higher, the aging time can be shortened, and when it is 90 ° C. or lower, a decrease in water content can be suppressed.
  • the aging time may be, for example, 1 to 48 hours, or 3 to 24 hours.
  • the aging time is 1 hour or longer, excellent heat insulating properties can be easily obtained, and when it is 48 hours or shorter, high adhesion between the airgel layer and the main body portion or the coating layer can be obtained.
  • the washing and solvent substitution step is a step having a step of washing the structure obtained by the aging step (washing step) and a step of substitution with a solvent suitable for the drying step (solvent substitution step).
  • the cleaning and solvent replacement method is not particularly limited, and for example, continuous processing can be performed using a plurality of cleaning tanks and / or solvent replacement tanks by conveyor conveyance.
  • the cleaning and solvent replacement step can be carried out in a form in which only the solvent replacement step is performed without performing the step of cleaning the structure, but it is possible to reduce impurities such as unreacted substances and by-products in the airgel layer.
  • the airgel layer can be washed from the viewpoint of enabling production of a highly pure structure.
  • the structure obtained in the aging step can be repeatedly washed with water or an organic solvent.
  • Organic solvents include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, acetone, methyl ethyl ketone, 1,2-dimethoxyethane, acetonitrile, hexane, toluene, diethyl ether, chloroform, ethyl acetate, tetrahydrofuran, methylene chloride , N, N-dimethylformamide, dimethyl sulfoxide, acetic acid, formic acid, and other various organic solvents can be used. You may use an organic solvent individually or in mixture of 2 or more types.
  • a low surface tension solvent may be used to suppress shrinkage of the airgel layer due to drying.
  • low surface tension solvents generally have very low mutual solubility with water. Therefore, when a low surface tension solvent is used in the solvent replacement step, a hydrophilic organic solvent having high mutual solubility in both water and a low surface tension solvent is used as the organic solvent used in the washing step. it can. Note that the hydrophilic organic solvent used in the washing step can serve as a preliminary replacement for the solvent replacement step.
  • methanol, ethanol, 2-propanol, acetone, or methyl ethyl ketone can be used from the viewpoint of being a hydrophilic organic solvent among the above organic solvents, and methanol, ethanol can be used from the viewpoint of excellent economy.
  • methyl ethyl ketone can be used.
  • the amount of water or organic solvent used in the washing step can be an amount that can sufficiently wash the solvent in the airgel layer and can be washed, and is 3 to 10 times the volume of the airgel layer. These solvents can be used.
  • the washing can be repeated until the water content in the airgel layer after washing becomes 10% by mass or less.
  • a temperature below the boiling point of the solvent used for washing can be used.
  • a temperature of about 30 to 60 ° C. can be used.
  • the solvent in the washed airgel layer can be replaced with a predetermined replacement solvent in order to suppress the shrinkage of the airgel layer in the drying step.
  • the replacement efficiency can be improved by heating.
  • a solvent having a low surface tension which will be described later, can be used in the drying step when drying under atmospheric pressure at a temperature lower than the critical point of the solvent used for drying.
  • a solvent such as ethanol, methanol, 2-propanol, dichlorodifluoromethane, carbon dioxide, or the like can be used alone, or a solvent in which two or more of these are mixed can be used.
  • the low surface tension solvent may be a solvent having a surface tension at 20 ° C. of 30 mN / m or less, a solvent of 25 mN / m or less, or a solvent of 20 mN / m or less.
  • Examples of the low surface tension solvent include pentane (15.5), hexane (18.4), heptane (20.2), octane (21.7), 2-methylpentane (17.4), 3- Aliphatic hydrocarbons such as methylpentane (18.1), 2-methylhexane (19.3), cyclopentane (22.6), cyclohexane (25.2), 1-pentene (16.0); Aromatic hydrocarbons such as (28.9), toluene (28.5), m-xylene (28.7), p-xylene (28.3); dichloromethane (27.9), chloroform (27.2) ), Carbon tetrachloride (26.9), 1-chloropropane (21.8), 2-chloropropane (18.1) and other halogenated hydrocarbons; ethyl ether (17.1), propyl ether (20.5) ), Isop Ethers such as pyrether (17.7), butyl ethy
  • aliphatic hydrocarbons may be used, and hexane or heptane may be used.
  • a hydrophilic organic solvent such as acetone, methyl ethyl ketone, 1,2-dimethoxyethane, it can be used as the organic solvent in the washing step.
  • a solvent having a boiling point of 100 ° C. or less at normal pressure may be used from the viewpoint of easy drying in the drying step.
  • Low surface tension solvents may be used alone or in combination of two or more.
  • an amount capable of sufficiently replacing the solvent in the airgel layer after washing can be used, and the amount of the solvent is 3 to 10 times the volume of the airgel layer. Can be used.
  • a temperature below the boiling point of the solvent used for the replacement can be used.
  • a temperature of about 30 to 60 ° C. can be used.
  • the solvent replacement step is not necessarily essential.
  • the inferred mechanism is as follows.
  • the silica particles function as a three-dimensional network airgel skeleton support, whereby the skeleton is supported and gel shrinkage in the drying process is suppressed. Therefore, it is considered that the gel can be directly transferred to the drying step without replacing the solvent used for washing.
  • the drying method is not particularly limited, and known atmospheric pressure drying, supercritical drying, or freeze drying can be used.
  • atmospheric drying or supercritical drying can be used from the viewpoint of easy production of a low-density airgel layer. From the viewpoint of being able to produce at low cost, atmospheric drying can be used.
  • “normal pressure” means 0.1 MPa (atmospheric pressure).
  • the structure according to the present embodiment can be obtained, for example, by drying a structure after washing and solvent substitution (if necessary) at a temperature below the critical point of the solvent used for drying under atmospheric pressure. It can.
  • the drying temperature varies depending on the type of the substituted solvent (the solvent used for washing when solvent substitution is not performed) or the heat resistance of the main body, but may be 60 to 500 ° C., or 90 to 150 ° C. There may be.
  • the drying time varies depending on the capacity of the airgel layer and the drying temperature, but may be 2 to 48 hours. In the present embodiment, drying can be accelerated by applying pressure within a range that does not impair productivity.
  • the structure according to the present embodiment may be pre-dried before the drying step from the viewpoint of improving the drying efficiency in atmospheric drying.
  • the predrying temperature may be 60 to 180 ° C, or 90 to 150 ° C.
  • the pre-drying time varies depending on the volume of the airgel layer and the drying temperature, but may be 1 to 30 minutes.
  • supercritical drying can also be used as a drying method.
  • Supercritical drying can be performed by a known method.
  • the supercritical drying method include a method of removing the solvent at a temperature and pressure higher than the critical point of the solvent contained in the airgel layer.
  • the airgel layer is immersed in liquefied carbon dioxide under conditions of, for example, about 20 to 25 ° C. and about 5 to 20 MPa, so that all or part of the solvent contained in the airgel layer is used. And carbon dioxide having a lower critical point than that of the solvent, and then removing carbon dioxide alone or a mixture of carbon dioxide and the solvent.
  • the manufacturing method of a structure is not limited to this embodiment.
  • the airgel layer which concerns on this embodiment is applicable to water-repellent uses, such as an architecture field, a clothing field, a motor vehicle field, a household appliance field, a semiconductor field, an industrial facility, for example.
  • the airgel layer can be used for a heat insulating application, a sound absorbing application, a static vibration application, a catalyst supporting application and the like in addition to the application as a water repellent material.
  • the following glass plate, aluminum plate, SUS piping and PET film were prepared as the main body.
  • Glass plate Tempax (manufactured by Toshin Rikou Co., Ltd., dimensions: 100 mm x 100 mm x 2 mm)
  • Aluminum plate A1035P (manufactured by Takeuchi Metal Foil Powder Industry Co., Ltd., dimensions: 100 mm x 100 mm x 0.5 mm)
  • SUS piping SUS316TPD (manufactured by Mori Kogyo Co., Ltd., outer diameter 115 mm ⁇ thickness 2 mm ⁇ length 50 mm)
  • PET film Tetoron G2 (Teijin Limited, dimensions: 100 mm x 100 mm x 0.1 mm)
  • intermediate layer (Formation of coating layer (hereinafter also referred to as “intermediate layer”)) An intermediate layer 1 and an intermediate layer 2 were formed on the prepared various main body portions in the combinations shown in Table 1 as follows.
  • Sol coating liquid [Sol coating solution 1] ST-OXS (manufactured by Nissan Chemical Industries, Ltd., product name, average primary particle size: 5 nm, solid content: 10% by mass) as silica particle-containing raw material 100.0 parts by mass, water 50.0 parts by mass, acid catalyst As a mixture, 0.10 parts by mass of acetic acid, 20.0 parts by mass of CTAB as a cationic surfactant and 120.0 parts by mass of urea as a thermohydrolyzable compound were mixed to obtain a mixed solution.
  • methyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd., product name: LS-530, hereinafter abbreviated as “MTMS”
  • MTMS methyltrimethoxysilane
  • DDMS dimethyldimethoxysilane
  • Solid coating liquid 2 As a silica particle-containing raw material, 100.0 parts by mass of ST-OXS, 100.0 parts by mass of water, and 100.0 parts by mass of methanol were mixed to obtain a mixed solution. To this mixed solution, 80.0 parts by mass of MTMS as a silicon compound and 60.0 parts by mass of KBE-22 (dimethyldiethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name) are added and reacted at 25 ° C. for 2 hours. It was. A sol coating solution 2 was obtained by adding 50.0 parts by mass of 5% aqueous ammonia as a base catalyst.
  • KBM-3063 hexyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name
  • KBM-3086 (1,8-bis (trimethoxysilyl) octane, 80.0 parts by mass of Shin-Etsu Chemical Co., Ltd., product name) was added and reacted at 25 ° C. for 2 hours. Thereafter, a sol-gel reaction was performed at 60 ° C. for 2 hours to obtain a sol coating solution 3.
  • Solid coating solution 4 As a silica particle-containing raw material, PL-2L (manufactured by Fuso Chemical Industry Co., Ltd., product name, average primary particle size: 20 nm, solid content: 20% by mass) is 100.0 parts by mass, water is 50.0 parts by mass, acid 0.10 parts by mass of acetic acid as a catalyst, 20.0 parts by mass of CTAB as a cationic surfactant, and 120.0 parts by mass of urea as a thermohydrolyzable compound were mixed to obtain a mixed solution.
  • PL-2L manufactured by Fuso Chemical Industry Co., Ltd., product name, average primary particle size: 20 nm, solid content: 20% by mass
  • Solid coating solution 5 100.0 parts by mass of PL-2L as a raw material containing silica particles, 100.0 parts by mass of water, 0.10 parts by mass of acetic acid as an acid catalyst, 20.0 parts by mass of CTAB as a cationic surfactant, and hot water addition
  • 120.0 parts by mass of urea was mixed to obtain a mixed solution.
  • the “polysiloxane compound A” was synthesized as follows. First, 100.0 mass of dimethylpolysiloxane (product name: XC96-723, manufactured by Momentive) having silanol groups at both ends in a 1 L three-necked flask equipped with a stirrer, a thermometer, and a Dimroth condenser. Parts, 181.3 parts by mass of methyltrimethoxysilane and 0.50 parts by mass of t-butylamine were mixed and reacted at 30 ° C. for 5 hours. Thereafter, this reaction solution was heated at 140 ° C. for 2 hours under reduced pressure of 1.3 kPa to remove volatile components, thereby obtaining a bifunctional alkoxy-modified polysiloxane compound (polysiloxane compound A) at both ends.
  • dimethylpolysiloxane product name: XC96-723, manufactured by Momentive
  • silica particle-containing raw material 100.0 parts by mass
  • water 100.0 parts by mass
  • 0.10 parts by mass of acetic acid as an acid catalyst, 20.0 parts by mass of CTAB as a cationic surfactant, and 120.0 parts by mass of urea as a thermohydrolyzable compound were mixed to obtain a mixed solution.
  • polysiloxane compound B a bifunctional alkoxy-modified polysiloxane compound having a structure represented by the above general formula (B) as a polysiloxane compound 40.0 parts by mass
  • the “polysiloxane compound B” was synthesized as follows. First, 100.0 parts by mass of XC96-723, 202.6 parts by mass of tetramethoxysilane and 0.50 of t-butylamine in a 1 L three-necked flask equipped with a stirrer, a thermometer and a Dimroth condenser. Mass parts were mixed and reacted at 30 ° C. for 5 hours. Thereafter, this reaction solution was heated at 140 ° C. for 2 hours under a reduced pressure of 1.3 kPa to remove volatile components, thereby obtaining a trifunctional alkoxy-modified polysiloxane compound (polysiloxane compound B) at both ends.
  • KBM-3063 hexyltrimethoxysilane
  • airgel composite structure (Production of structure (hereinafter also referred to as “airgel composite structure”))
  • the airgel layers 1 to 7 are formed on the main body or the intermediate layer in the combinations shown in Table 1 as follows, and the airgel layer is integrally joined to the main body directly or via the intermediate layer.
  • An airgel composite structure comprising:
  • the aged structure was immersed in 2000 mL of water and washed for 30 minutes. Next, it was immersed in 2000 mL of methanol and washed at 60 ° C. for 30 minutes. Washing with methanol was performed twice more while exchanging with fresh methanol. Next, it was immersed in 2000 mL of methyl ethyl ketone, and solvent substitution was performed at 60 ° C. for 30 minutes. Washing with methyl ethyl ketone was performed twice more while exchanging with new methyl ethyl ketone.
  • the washed and solvent-substituted structure is dried at 120 ° C. for 6 hours under normal pressure, so that the airgel layer 1 including the airgel having the structure represented by the general formulas (4) and (5) (main body)
  • An airgel composite structure provided with an airgel layer integrally bonded directly to the part or via an intermediate layer was obtained.
  • the sol coating liquid 2 is applied in a mist form on the main body or intermediate layer using a spray gun so that the thickness after gelation is 500 ⁇ m, and the structure is gelled at 60 ° C. for 30 minutes. Obtained. Thereafter, the obtained structure was transferred to a sealed container and aged at 60 ° C. for 12 hours.
  • the washing and solvent replacement step and the drying step are performed in the same manner as the method described in “Airgel layer 1”, and the airgel layer 2 includes the airgel having the structure represented by the general formulas (4) and (5).
  • An airgel composite structure provided with an airgel layer integrally bonded to the main body directly or via an intermediate layer was obtained.
  • a foamed urethane foam structure was obtained by applying a foamed urethane foam (manufactured by Henkel Japan Co., Ltd., product name: Sista M5230) to a glass plate as the main body so as to have a thickness of 100 ⁇ m.
  • a foamed urethane foam manufactured by Henkel Japan Co., Ltd., product name: Sista M5230

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Abstract

The present invention pertains to a method for producing a structure on which an aerogel layer is formed, wherein the method for producing a structure is provided with a step for forming an aerogel layer from a mist-form sol.

Description

構造体の製造方法Manufacturing method of structure
　本発明は、構造体の製造方法に関する。 The present invention relates to a method for manufacturing a structure.
　エアロゲルとしては、例えば、シリカエアロゲルが知られている（例えば、特許文献１を参照）。シリカエアロゲルは、一般的に、超臨界乾燥法を用いた方法により製造される。 As an airgel, for example, silica airgel is known (for example, see Patent Document 1). Silica airgel is generally produced by a method using a supercritical drying method.
　特許文献２には、超臨界乾燥法を用いずに、シリカキセロゲルを製造することが記載されている。 Patent Document 2 describes that silica xerogel is produced without using a supercritical drying method.
米国特許第４４０２９２７号U.S. Pat. No. 4,402,927 特開２０１１－９３７４４号公報JP 2011-93744 A
　ところで、エアロゲル層が形成された構造体を製造する場合には、エアロゲル層を形成する対象である対象物に対して、ムラの少ないエアロゲル層を形成することが求められる。 By the way, when manufacturing a structure in which an airgel layer is formed, it is required to form an airgel layer with less unevenness with respect to an object that is an object for forming the airgel layer.
　本発明は、上記の事情に鑑みてなされたものであり、エアロゲル層のムラを抑制することができる構造体の製造方法を提供することを目的とする。 This invention is made | formed in view of said situation, and it aims at providing the manufacturing method of the structure which can suppress the nonuniformity of an airgel layer.
　本発明者は、上記目的を達成するために鋭意研究を重ねた結果、ミスト状のゾルを用いてエアロゲル層を形成する方法を見出し、本発明の完成に至った。 As a result of intensive studies to achieve the above object, the present inventor has found a method for forming an airgel layer using a mist-like sol, and has completed the present invention.
　本発明は、エアロゲル層が形成された構造体の製造方法であって、ミスト状のゾルからエアロゲル層を形成する工程を備える、構造体の製造方法を提供する。 The present invention provides a method for producing a structure in which an airgel layer is formed, the method comprising the step of forming an airgel layer from a mist-like sol.
　本発明に係る構造体の製造方法によれば、エアロゲル層のムラが抑制された構造体を製造することができる。また、本発明に係る構造体の製造方法によれば、エアロゲル層を形成する対象物の形状に依存することなく、厚膜のエアロゲル層を形成できる。 The structure manufacturing method according to the present invention can manufacture a structure in which unevenness of the airgel layer is suppressed. Moreover, according to the structure manufacturing method according to the present invention, a thick airgel layer can be formed without depending on the shape of the object forming the airgel layer.
　ところで、超臨界乾燥法によりエアロゲルを製造する場合、アルコゲルと分散媒（乾燥に用いる溶媒）とを高圧容器中に導入し、分散媒をその臨界点以上の温度と圧力をかけて超臨界流体とすることにより、アルコゲルに含まれる溶媒を除去する方法が一般的である。超臨界乾燥法は、通常、高圧プロセスである。エアロゲルを製造する上で超臨界乾燥を行う場合には、超臨界に耐え得る特殊な装置等への設備投資並びに多くの手間及び時間が必要であり、製造コストが高くなること及びバッチ式の生産によるため製造効率が充分でないことがある。また、超臨界乾燥を行う場合、エアロゲル層を形成する対象物は、超臨界に耐え得る材料に限定されると考えられる。これに対し、本発明に係る構造体の製造方法の一態様では、超臨界乾燥を用いることなく構造体を得ることもできる。さらに、本発明に係る構造体の製造方法により製造された構造体は、エアロゲルとしての優れた機能を有すると共にエアロゲルの脱落が抑制されたものとなる。 By the way, when producing an airgel by the supercritical drying method, an alcogel and a dispersion medium (solvent used for drying) are introduced into a high-pressure vessel, and the dispersion medium is subjected to a temperature and pressure above its critical point to form a supercritical fluid. Thus, a method of removing the solvent contained in the alcogel is common. Supercritical drying is usually a high pressure process. When supercritical drying is performed in producing airgel, capital investment for special equipment that can withstand supercriticality and much labor and time are required, resulting in high production costs and batch production. Therefore, the production efficiency may not be sufficient. Moreover, when performing supercritical drying, it is thought that the object which forms an airgel layer is limited to the material which can endure supercritical. On the other hand, in one embodiment of the structure manufacturing method according to the present invention, a structure can be obtained without using supercritical drying. Furthermore, the structure manufactured by the method for manufacturing a structure according to the present invention has an excellent function as an airgel and the airgel is prevented from falling off.
　ところで、エアロゲルは、非常に脆い傾向がある。例えば、塊状のエアロゲルは、手で触って持ち上げようとするだけで破損してしまう場合がある。これに対し、従来、エアロゲルと補強材とを用いたエアロゲルシートが考案されている。しかし、エアロゲル自体が脆いため、衝撃又は折り曲げ作業によりシートが破れること、シートからエアロゲル粉末が脱落すること等の施工性の課題がある。一方、本発明において上記ゾルは、加水分解性の官能基又は縮合性の官能基を有するケイ素化合物、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物からなる群より選択される少なくとも一種を含有していてもよい。このようなゾルから形成されるエアロゲル層によれば、施工性の前記課題を容易に解決できると共に、断熱性を向上できる。また、このようなゾルから形成されるエアロゲル層によれば、柔軟性が向上されるため、エアロゲルの脱落が更に抑制されると共に、このようなエアロゲル層を備える構造体は、本体部の柔軟性に応じて折り曲げ易いものとなる。 By the way, airgel tends to be very brittle. For example, a mass of airgel may be damaged simply by trying to lift it by hand. On the other hand, conventionally, an airgel sheet using an airgel and a reinforcing material has been devised. However, since the airgel itself is fragile, there are problems in workability such as the sheet is torn by impact or bending work, and the airgel powder is dropped from the sheet. Meanwhile, in the present invention, the sol is selected from the group consisting of a hydrolyzable functional group or a silicon compound having a condensable functional group, and a hydrolysis product of the silicon compound having the hydrolyzable functional group. It may contain at least one kind. According to the airgel layer formed from such a sol, the problem of workability can be easily solved and the heat insulation can be improved. In addition, according to the airgel layer formed from such a sol, the flexibility is improved, so that the aerogel is further prevented from falling off, and the structure including such an airgel layer has the flexibility of the main body. It becomes easy to bend according to.
　上記ゾルは、シリカ粒子を更に含有していてもよい。これにより、断熱性及び柔軟性が更に向上する。 The sol may further contain silica particles. Thereby, heat insulation and a softness | flexibility improve further.
　上記シリカ粒子の平均一次粒子径は、１～５００ｎｍであってもよい。これにより、断熱性及び柔軟性が更に向上し易くなる。 The average primary particle diameter of the silica particles may be 1 to 500 nm. Thereby, heat insulation and a softness | flexibility further improve easily.
　上記ゾルの液滴の直径は、０．１～１０００μｍであってもよい。このようなゾルによれば、厚膜のエアロゲル層をより容易に形成できるうえ、エアロゲル層のクラックが更に抑制される。 The diameter of the sol droplet may be 0.1 to 1000 μm. According to such a sol, a thick airgel layer can be formed more easily, and cracks in the airgel layer are further suppressed.
　上記ゾルは、沸点２００℃未満の溶媒を含有していてもよい。このようなゾルによれば、厚膜のエアロゲル層を更に容易に形成できるうえ、エアロゲル層のクラックが更に抑制される。 The sol may contain a solvent having a boiling point of less than 200 ° C. According to such a sol, a thick airgel layer can be formed more easily, and cracks in the airgel layer are further suppressed.
　上記製造方法においては、前記構造体が、本体部と、前記本体部の表面の少なくとも一部を被覆する被覆層とを備え、前記被覆層が中間層となるように、少なくとも前記被覆層上にエアロゲル層が形成されてもよい。これにより、エアロゲル層の密着性が更に向上すると共に、エアロゲル層の剥離及び脱落が更に抑制される。 In the manufacturing method, the structure includes a main body and a coating layer that covers at least a part of the surface of the main body, and at least on the coating layer so that the coating layer becomes an intermediate layer. An airgel layer may be formed. Thereby, the adhesiveness of the airgel layer is further improved, and peeling and dropping of the airgel layer are further suppressed.
　上記被覆層は、充填材を含有していてもよい。これにより、高温使用時におけるエアロゲル層の剥離及び脱落が更に抑制される。 The coating layer may contain a filler. Thereby, peeling and dropping of the airgel layer at the time of high temperature use are further suppressed.
　上記充填材は、無機充填材であってもよい。これにより、被覆層（中間層）の耐熱性が向上すると共に、高温条件における剥離及び脱落が更に抑制される。 The filler may be an inorganic filler. This improves the heat resistance of the coating layer (intermediate layer) and further suppresses peeling and dropping off under high temperature conditions.
　上記充填材の含有量は、被覆層の全体積に対して、０．１～７０体積％であってもよい。これにより、耐熱性及び本体部とエアロゲル層との密着性が更に向上する。 The content of the filler may be 0.1 to 70% by volume with respect to the total volume of the coating layer. Thereby, heat resistance and the adhesiveness of a main-body part and an airgel layer further improve.
　本発明に係る構造体の製造方法によれば、エアロゲル層のムラが抑制された構造体を製造することができる。また、本発明に係る構造体の製造方法によれば、本体部の形状に依存することなく、厚膜のエアロゲル層を形成できる。さらに、本発明に係る構造体の製造方法により製造された構造体は、優れた断熱性、撥水性、特異な光学特性、及び特異な電気特性を有すると共にエアロゲルの脱落が抑制されたものとなる。 The structure manufacturing method according to the present invention can manufacture a structure in which unevenness of the airgel layer is suppressed. Moreover, according to the structure manufacturing method of the present invention, a thick airgel layer can be formed without depending on the shape of the main body. Furthermore, the structure manufactured by the method for manufacturing a structure according to the present invention has excellent heat insulating properties, water repellency, specific optical characteristics, and specific electrical characteristics, and airgel drop-off is suppressed. .
本発明の一実施形態に係る構造体の製造方法により得られる構造体を模式的に示す断面図である。It is sectional drawing which shows typically the structure obtained by the manufacturing method of the structure which concerns on one Embodiment of this invention. 本発明の一実施形態に係る構造体の製造方法により得られる構造体を模式的に示す断面図である。It is sectional drawing which shows typically the structure obtained by the manufacturing method of the structure which concerns on one Embodiment of this invention. 粒子の二軸平均一次粒子径の算出方法を示す図である。It is a figure which shows the calculation method of the biaxial average primary particle diameter of particle | grains. 本発明の一実施形態に係る構造体の製造方法を説明する図である。It is a figure explaining the manufacturing method of the structure concerning one embodiment of the present invention. 本発明の一実施形態に係る構造体の製造方法を説明する図である。It is a figure explaining the manufacturing method of the structure concerning one embodiment of the present invention.
　以下、場合により図面を参照しつつ本発明の実施形態について詳細に説明する。ただし、本発明は以下の実施形態に限定されるものではない。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as the case may be. However, the present invention is not limited to the following embodiments.
＜定義＞
　本明細書において、「～」を用いて示された数値範囲は、「～」の前後に記載される数値をそれぞれ最小値及び最大値として含む範囲を示す。本明細書に段階的に記載されている数値範囲において、ある段階の数値範囲の上限値又は下限値は、他の段階の数値範囲の上限値又は下限値に置き換えてもよい。本明細書に記載されている数値範囲において、その数値範囲の上限値又は下限値は、実施例に示されている値に置き換えてもよい。「Ａ又はＢ」とは、Ａ及びＢのどちらか一方を含んでいればよく、両方とも含んでいてもよい。本明細書に例示する材料は、特に断らない限り、１種を単独で又は２種以上を組み合わせて用いることができる。本明細書において、組成物中の各成分の含有量は、組成物中に各成分に該当する物質が複数存在する場合、特に断らない限り、組成物中に存在する複数の物質の合計量を意味する。 <Definition>
In this specification, a numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value of a numerical range in a certain step may be replaced with the upper limit value or the lower limit value of a numerical range in another step. In the numerical range described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples. “A or B” only needs to include either A or B, and may include both. The materials exemplified in the present specification can be used singly or in combination of two or more unless otherwise specified. In the present specification, the content of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. means.
　まず、本実施形態に係る構造体の製造方法により得られる構造体について説明する。 First, the structure obtained by the structure manufacturing method according to the present embodiment will be described.
＜構造体＞
　図１は、本実施形態に係る構造体の製造方法により得られる構造体を模式的に示す断面図である。構造体（エアロゲル複合体、エアロゲル複合構造体）１００は、図１に示すように、エアロゲル層を形成する対象である対象物（以下、「対象物」ともいう）１０にエアロゲル層５が形成された構造を有する。構造体１００は、例えば、対象物１０にエアロゲル層５が一体的に形成された構造を有するものであってもよい。すなわち、構造体１００は、対象物１０と、当該対象物１０に一体的に接合されたエアロゲル層５と、を備えるものであってもよい。構造体１００においては、例えば、対象物１０とエアロゲル層５とが一体化して固定されていてもよい。エアロゲル層５は、ミスト状（霧状）のゾルから形成されたエアロゲル層である。対象物１０は、例えば、エアロゲル層５を支持する支持部である。本実施形態に係る構造体１００は、断熱性及び撥水性に優れ、特異な光学特性及び電気特性に優れていると共にエアロゲルの脱落が抑制されたものである。 <Structure>
FIG. 1 is a cross-sectional view schematically showing a structure obtained by the structure manufacturing method according to the present embodiment. As shown in FIG. 1, the structure (aerogel composite, airgel composite structure) 100 has an airgel layer 5 formed on an object 10 (hereinafter also referred to as “object”) that is an object for forming an airgel layer. Has a structure. The structure 100 may have, for example, a structure in which the airgel layer 5 is integrally formed on the object 10. That is, the structure 100 may include the target object 10 and the airgel layer 5 integrally bonded to the target object 10. In the structure 100, for example, the object 10 and the airgel layer 5 may be integrally fixed. The airgel layer 5 is an airgel layer formed from a mist-like (mist-like) sol. The object 10 is a support part that supports the airgel layer 5, for example. The structure 100 according to the present embodiment is excellent in heat insulation and water repellency, is excellent in unique optical characteristics and electrical characteristics, and is suppressed from falling off the airgel.
　本実施形態に係る構造体１００は、例えば、対象物１０の表面１０ａの少なくとも一部（一部又は全体）に配置されたエアロゲル層５を備える構造体である。このような構造体１００は、優れた断熱性、撥水性、特異な光学特性及び電気特性を発現することができると共にエアロゲルの脱落が抑制されたものとなると考えられる。エアロゲル層５が配置される表面１０ａは、平坦面であってもよく、複合平面（傾斜面の組合せ）であってもよく、曲面であってもよい。 The structure 100 according to the present embodiment is a structure including an airgel layer 5 disposed on at least a part (a part or the whole) of the surface 10a of the object 10, for example. Such a structure 100 is considered to exhibit excellent heat insulating properties, water repellency, unique optical characteristics and electrical characteristics, and to prevent the airgel from falling off. The surface 10a on which the airgel layer 5 is disposed may be a flat surface, a composite plane (combination of inclined surfaces), or a curved surface.
　対象物１０は、図２に示すように、本体部３と、本体部３の表面の少なくとも一部を被覆する被覆層４とを備えるものであってもよい。この場合、被覆層４が中間層となるように、少なくとも被覆層４上にエアロゲル層５が形成される。 2, the object 10 may include a main body 3 and a covering layer 4 that covers at least part of the surface of the main body 3. In this case, the airgel layer 5 is formed on at least the coating layer 4 so that the coating layer 4 becomes an intermediate layer.
　図２は、本実施形態に係る構造体の製造方法により得られる構造体を模式的に示す断面図である。構造体（エアロゲル複合体、エアロゲル複合構造体）２００は、本体部３と、本体部３の表面の少なくとも一部を被覆する被覆層４とを備え、被覆層４が中間層となるように、少なくとも被覆層４上にエアロゲル層５が形成された構造を有する。すなわち、対象物１０は、本体部３と、本体部３の表面の少なくとも一部を被覆する被覆層４とを備えていてもよい。例えば、構造体２００は、本体部３と、本体部３に中間層となる被覆層４を介して一体的に接合されたエアロゲル層５と、を備えるものであってもよい。構造体２００においては、エアロゲル層５が、本体部３に、中間層となる被覆層４を介して一体的に接合されていてもよい。構造体２００においては、本体部３と被覆層４とエアロゲル層５とが一体化されていてもよい。本体部３は、例えば、エアロゲル層５を支持する支持部である。本実施形態に係る構造体２００は、本体部３とエアロゲル層５との接着性及び密着性に優れると共に、エアロゲル層５の剥離及び脱落を更に高度に抑制できる。構造体２００は、本体部３の保護性能にも優れる。 FIG. 2 is a cross-sectional view schematically showing a structure obtained by the structure manufacturing method according to the present embodiment. The structure (aerogel composite, airgel composite structure) 200 includes a main body 3 and a coating layer 4 that covers at least a part of the surface of the main body 3 so that the coating layer 4 is an intermediate layer. At least the airgel layer 5 is formed on the coating layer 4. That is, the object 10 may include the main body 3 and the coating layer 4 that covers at least a part of the surface of the main body 3. For example, the structure 200 may include the main body 3 and the airgel layer 5 that is integrally joined to the main body 3 via the coating layer 4 that is an intermediate layer. In the structure 200, the airgel layer 5 may be integrally joined to the main body part 3 via the coating layer 4 serving as an intermediate layer. In the structure 200, the main body 3, the coating layer 4, and the airgel layer 5 may be integrated. The main body 3 is, for example, a support that supports the airgel layer 5. The structure 200 according to the present embodiment is excellent in adhesiveness and adhesion between the main body 3 and the airgel layer 5, and can further suppress the peeling and dropping of the airgel layer 5. The structure 200 is also excellent in the protection performance of the main body 3.
　本実施形態に係る構造体２００は、例えば、本体部３の表面３ａの少なくとも一部（一部又は全体）に配置された被覆層（「中間層」ともいう）４と、被覆層４の本体部３とは反対側の表面４ａの少なくとも一部（一部又は全体）に配置されたエアロゲル層５を備える構造体である。本実施形態に係る構造体２００では、本体部３とエアロゲル層５とが、中間層となる被覆層４を介して一体化して固定されている。被覆層４が配置される表面３ａは、平坦面であってもよく、複合平面（傾斜面の組合せ）であってもよく、曲面であってもよい。 The structure 200 according to the present embodiment includes, for example, a coating layer (also referred to as “intermediate layer”) 4 disposed on at least a part (a part or the whole) of the surface 3a of the main body 3, and the main body of the coating layer 4 The structure includes an airgel layer 5 disposed on at least a part (a part or the whole) of the surface 4a opposite to the part 3. In the structure 200 according to the present embodiment, the main body 3 and the airgel layer 5 are integrally fixed via a covering layer 4 serving as an intermediate layer. The surface 3a on which the coating layer 4 is disposed may be a flat surface, a composite plane (a combination of inclined surfaces), or a curved surface.
　図２においては、構造体が、本体部と本体部３を被覆する被覆層とを備える態様について説明したが、被覆層は必ずしも必須ではない。すなわち、エアロゲル層を形成する対象である対象物は、本体部であってもよい。 In FIG. 2, although the aspect in which the structure includes the main body portion and the covering layer that covers the main body portion 3 has been described, the covering layer is not necessarily essential. That is, the target object that forms the airgel layer may be the main body.
　対象物が本体部である場合、構造体は、例えば、本体部の表面の少なくとも一部（一部又は全体）に配置されたエアロゲル層を備える構造体であり、本体部とエアロゲル層とが直接接触した構造を有する。本態様においても、エアロゲル層が配置される本体部の表面は、平坦面であってもよく、複合平面（傾斜面の組合せ）であってもよく、曲面であってもよい。 When the object is a main body, the structure is a structure including an airgel layer disposed on at least a part (a part or the whole) of the surface of the main body, and the main body and the airgel layer are directly It has a contact structure. Also in this aspect, the surface of the main body portion on which the airgel layer is disposed may be a flat surface, a composite plane (combination of inclined surfaces), or a curved surface.
　エアロゲル層５は、加水分解性の官能基又は縮合性の官能基を有するケイ素化合物（シリコン化合物）、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物（加水分解性の官能基が加水分解したケイ素化合物）からなる群より選択される少なくとも一種を含有するゾルから形成されたものであってもよく、加水分解性の官能基又は縮合性の官能基を有するケイ素化合物（シリコン化合物）、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物（加水分解性の官能基が加水分解したケイ素化合物）からなる群より選択される少なくとも一種を含有するゾルの縮合物である湿潤ゲル（前記ゾルに由来する湿潤ゲル）の乾燥物から構成される層であってもよい。すなわち、前記ゾルは加水分解性の官能基又は縮合性の官能基を有するケイ素化合物、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物からなる群より選択される少なくとも一種を含有していてもよい。エアロゲル層がこのようなものであることにより、断熱性及び柔軟性を高度に両立できると共に、エアロゲルの脱落が更に抑制されたものとなる。 The airgel layer 5 includes a hydrolyzable functional group or a silicon compound having a condensable functional group (silicon compound) and a hydrolysis product (hydrolyzable functional group) of the silicon compound having the hydrolyzable functional group. A silicon compound (silicon) having a hydrolyzable functional group or a condensable functional group, which may be formed from a sol containing at least one selected from the group consisting of hydrolyzed silicon compounds) Compound), and condensation of sol containing at least one selected from the group consisting of hydrolysis products of silicon compounds having hydrolyzable functional groups (silicon compounds in which hydrolyzable functional groups are hydrolyzed) It may be a layer composed of a dried product of a wet gel (a wet gel derived from the sol). That is, the sol comprises at least one selected from the group consisting of a hydrolyzable functional group or a silicon compound having a condensable functional group, and a hydrolysis product of the silicon compound having the hydrolyzable functional group. You may contain. When the airgel layer is such, both heat insulation and flexibility can be achieved at a high level, and the airgel can be prevented from dropping off.
｛対象物｝
　上述のとおり、エアロゲル層を形成する対象である対象物は、本体部と、本体部の表面の少なくとも一部を被覆する被覆層とを備えるものであってもよく、本体部であってもよい。 {Object}
As described above, the target object that forms the airgel layer may include a main body part and a coating layer that covers at least a part of the surface of the main body part, or may be a main body part. .
（本体部）
　本体部を構成する材料としては、例えば、金属、セラミック、ガラス、樹脂及びこれらの複合材料が挙げられる。本体部は、例えば、金属、セラミック、ガラス及び樹脂からなる群より選択される少なくとも一種を含む態様であってもよい。本体部の形態としては、使用する目的又は材料に応じて、ブロック状、シート状、球状、繊維状等が採用できる。 (Main body)
Examples of the material constituting the main body include metal, ceramic, glass, resin, and composite materials thereof. For example, the main body may include at least one selected from the group consisting of metal, ceramic, glass, and resin. As the form of the main body, a block shape, a sheet shape, a spherical shape, a fiber shape, or the like can be adopted depending on the purpose or material to be used.
　前記金属としては、特に限定されず、金属の単体；金属の合金；酸化被膜が形成された金属等が挙げられる。前記金属としては、鉄、銅、ニッケル、アルミニウム、亜鉛、チタン、クロム、コバルト、スズ、金、銀等が挙げられる。後述のゾル生成工程で使用する材料によっては、金属表面の耐食性に優れる観点から、前記金属として、チタン、金、銀等の単体；酸化被膜が形成された鉄及びアルミニウムを用いることができる。 The metal is not particularly limited, and examples include a single metal, a metal alloy, and a metal on which an oxide film is formed. Examples of the metal include iron, copper, nickel, aluminum, zinc, titanium, chromium, cobalt, tin, gold, and silver. Depending on the material used in the sol production step described later, from the viewpoint of excellent corrosion resistance of the metal surface, simple metals such as titanium, gold and silver; iron and aluminum on which an oxide film is formed can be used as the metal.
　前記セラミックとしては、アルミナ、チタニア、ジルコニア、マグネシア等の酸化物；窒化ケイ素、窒化アルミニウム等の窒化物；炭化ケイ素、炭化ホウ素等の炭化物；これらの混合物などが挙げられる。 Examples of the ceramic include oxides such as alumina, titania, zirconia, and magnesia; nitrides such as silicon nitride and aluminum nitride; carbides such as silicon carbide and boron carbide; and mixtures thereof.
　前記ガラスとしては、石英ガラス、ソーダガラス、ホウケイ酸ガラス等が挙げられる。 Examples of the glass include quartz glass, soda glass, and borosilicate glass.
　前記樹脂としては、ポリ塩化ビニル、ポリビニルアルコール、ポリスチレン、ポリエチレン、ポリプロピレン、ポリアセタール、ポリメチルメタクリレート、ポリカーボネート、ポリアミド、ポリウレタン等が挙げられる。 Examples of the resin include polyvinyl chloride, polyvinyl alcohol, polystyrene, polyethylene, polypropylene, polyacetal, polymethyl methacrylate, polycarbonate, polyamide, and polyurethane.
　本体部の形状に特に制限は無く、平面及び曲面のいずれの表面形状を有するものであってもよい。本体部の形状としては、例えば、板状、筒状、球状、棒状が挙げられる。筒状の本体部としては、例えば、配管等が挙げられる。 There is no particular limitation on the shape of the main body, and it may have either a flat surface or a curved surface. Examples of the shape of the main body include a plate shape, a cylindrical shape, a spherical shape, and a rod shape. Examples of the cylindrical main body include piping.
　本体部の表面粗さは、良好なアンカー効果が得られ、エアロゲル層の密着性が更に向上する観点から、１００ｎｍ以上であってもよく、５００ｎｍ以上であってもよい。 The surface roughness of the main body may be 100 nm or more, or 500 nm or more from the viewpoint of obtaining a good anchor effect and further improving the adhesion of the airgel layer.
（被覆層（中間層））
　上述のとおり、対象物は、被覆層を備えていてもよい。被覆層を構成する材料としては、例えば、有機系材料、無機系材料及び有機無機ハイブリッド材料が挙げられる。 (Coating layer (intermediate layer))
As described above, the object may include a coating layer. Examples of the material constituting the coating layer include organic materials, inorganic materials, and organic-inorganic hybrid materials.
　上記有機系材料としては、例えば、ウレタン樹脂、ポリエステル樹脂、アクリル樹脂、フェノール樹脂、エポキシ樹脂、ポリイミド、ポリアミドイミド、ポリベンゾイミダゾール、ポリエーテルエーテルケトン、シリコーン及びこれらの複合材料が挙げられる。上記有機系材料は、例えば、ウレタン樹脂、ポリエステル樹脂、アクリル樹脂、フェノール樹脂、エポキシ樹脂、ポリイミド、ポリアミドイミド、ポリベンゾイミダゾール、ポリエーテルエーテルケトン及びシリコーンからなる群より選択される少なくとも一種を含む態様であってもよい。 Examples of the organic material include urethane resin, polyester resin, acrylic resin, phenol resin, epoxy resin, polyimide, polyamideimide, polybenzimidazole, polyetheretherketone, silicone, and composite materials thereof. The organic material includes, for example, at least one selected from the group consisting of urethane resin, polyester resin, acrylic resin, phenol resin, epoxy resin, polyimide, polyamideimide, polybenzimidazole, polyetheretherketone, and silicone. It may be.
　上記有機系材料は、本体部とエアロゲル層の密着が向上する観点から、例えば、水酸基、アミノ基、カルボキシル基、エポキシ基、イソシアネート基、メルカプト基、シアノ基、エステル結合、ウレタン結合及びアミド結合からなる群より選択される少なくとも一種を含む化合物であってもよい。 From the viewpoint of improving the adhesion between the main body and the airgel layer, the organic material is, for example, from a hydroxyl group, an amino group, a carboxyl group, an epoxy group, an isocyanate group, a mercapto group, a cyano group, an ester bond, a urethane bond, and an amide bond. A compound containing at least one selected from the group consisting of:
　上記無機系材料としては、例えば、ガラス、金属の単体、金属の合金、酸化被膜が形成された金属、セラミック、炭化ケイ素、窒化ケイ素及びケイ酸ナトリウムが挙げられる。上記無機系材料は、例えば、ガラス、金属の単体、金属の合金、酸化被膜が形成された金属、セラミック、炭化ケイ素、窒化ケイ素及びケイ酸ナトリウムからなる群より選択される少なくとも一種を含む態様であってもよい。 Examples of the inorganic material include glass, a single metal, a metal alloy, a metal on which an oxide film is formed, ceramic, silicon carbide, silicon nitride, and sodium silicate. The inorganic material includes, for example, at least one selected from the group consisting of glass, simple metal, metal alloy, metal with an oxide film, ceramic, silicon carbide, silicon nitride, and sodium silicate. There may be.
　上記金属としては、例えば、チタン、クロム、アルミニウム、銅及び白金が挙げられる。 Examples of the metal include titanium, chromium, aluminum, copper, and platinum.
　上記セラミックとしては、例えば、アルミナ及びジルコニアが挙げられる。 Examples of the ceramic include alumina and zirconia.
　上記無機系材料は、バインダを更に含有してもよい。バインダとしては、例えば、金属アルコキシド、水ガラスが挙げられる。 The inorganic material may further contain a binder. Examples of the binder include metal alkoxide and water glass.
　上記有機無機ハイブリッド材料としては、例えば、上記有機系材料及び上記無機系材料の複合材料、エポキシ－シリカハイブリッド材料、アクリル－シリカハイブリッド材料が挙げられる。 Examples of the organic-inorganic hybrid material include a composite material of the organic material and the inorganic material, an epoxy-silica hybrid material, and an acrylic-silica hybrid material.
　被覆層を構成する材料は、耐熱性が更に向上する観点から、無機系材料又は有機無機ハイブリッド材料であってもよく、高温環境下で使用する場合の本体部と被覆層との熱膨張差を低減し、クラックを抑制する観点から、有機無機ハイブリッド材料であってもよい。クラックを抑制する観点から、被覆層を構成する材料として、弾性率の低い材料を用いることもできる。 The material constituting the coating layer may be an inorganic material or an organic-inorganic hybrid material from the viewpoint of further improving the heat resistance, and the difference in thermal expansion between the main body and the coating layer when used in a high temperature environment. From the viewpoint of reducing and suppressing cracks, an organic-inorganic hybrid material may be used. From the viewpoint of suppressing cracks, a material having a low elastic modulus can also be used as a material constituting the coating layer.
　被覆層は、耐熱性が更に向上する観点から、例えば、セラミックから構成された層（セラミック層）及び／又は金属から構成された層（金属層）であってもよい。 From the viewpoint of further improving the heat resistance, the coating layer may be, for example, a layer composed of ceramic (ceramic layer) and / or a layer composed of metal (metal layer).
　上記被覆層は、耐熱性が更に向上する観点、クラックを更に抑制する観点、及び、高温使用時におけるエアロゲル層の剥離及び脱落を更に抑制する観点から、充填材を含有してもよい。充填材を含有することにより、エアロゲル層の剥離及び脱落が更に抑制される理由は、例えば、充填材を含有することにより被覆層の熱膨張率が調整され、高温時に本体部、被覆層及びエアロゲル層の間に生じる熱膨張率差が低減されるためであると推察する。 The coating layer may contain a filler from the viewpoint of further improving the heat resistance, further suppressing cracks, and further suppressing separation and dropping of the airgel layer during high temperature use. The reason why the airgel layer is further prevented from peeling and falling off by containing the filler is, for example, that the thermal expansion coefficient of the coating layer is adjusted by containing the filler, and the main body, the coating layer, and the airgel at high temperatures. It is assumed that this is because the difference in thermal expansion coefficient generated between the layers is reduced.
　上記充填材としては、例えば、無機充填材及び有機充填材が挙げられる。上記充填材は、被覆層の耐熱性を向上する観点、及び、高温条件における剥離及び脱落を更に抑制する観点から、無機充填材であってもよく、高温環境で繰り返し使用した場合の、熱サイクル信頼性が向上する観点から、有機充填材であってもよい。充填材の形状に特に制限はなく、例えば、短繊維状、微粉末状及び中空状であってもよい。 Examples of the filler include inorganic fillers and organic fillers. The filler may be an inorganic filler from the viewpoint of improving the heat resistance of the coating layer and further suppressing peeling and dropping under high temperature conditions, and a thermal cycle when repeatedly used in a high temperature environment. From the viewpoint of improving reliability, an organic filler may be used. There is no restriction | limiting in particular in the shape of a filler, For example, a short fiber form, fine powder form, and a hollow form may be sufficient.
　無機充填材を構成する材料としては、例えば、シリカ、マイカ、タルク、ガラス、炭酸カルシウム、石英、金属水和物、金属水酸化物及びこれらの複合材料が挙げられる。無機充填材は、例えば、シリカ、マイカ、タルク、ガラス、炭酸カルシウム、石英、金属水和物及び金属水酸化物からなる群より選択される少なくとも一種を含む態様であってもよい。 Examples of the material constituting the inorganic filler include silica, mica, talc, glass, calcium carbonate, quartz, metal hydrate, metal hydroxide, and composite materials thereof. For example, the inorganic filler may include at least one selected from the group consisting of silica, mica, talc, glass, calcium carbonate, quartz, metal hydrate, and metal hydroxide.
　金属水和物としては、例えば、硫酸カリウムアルミニウム１２水和物、硝酸マグネシウム６水和物、硫酸マグネシウム７水和物が挙げられる。金属水酸化物としては、例えば、水酸化アルミニウム及び水酸化マグネシウムが挙げられる。水酸化アルミニウムは、ベーマイト型水酸化アルミニウムであってもよい。 Examples of the metal hydrate include potassium aluminum sulfate 12 hydrate, magnesium nitrate hexahydrate, and magnesium sulfate heptahydrate. Examples of the metal hydroxide include aluminum hydroxide and magnesium hydroxide. The aluminum hydroxide may be boehmite type aluminum hydroxide.
　耐熱性及び難燃性が更に向上する観点から、無機充填材は、シリカ、ガラス又は金属水酸化物を含有するものであってもよく、ガラスは、ガラス短繊維又は中空ガラスであってもよく、金属水酸化物は、水酸化マグネシウム又はベーマイト型水酸化アルミニウムであってもよい。 From the viewpoint of further improving heat resistance and flame retardancy, the inorganic filler may contain silica, glass, or metal hydroxide, and the glass may be glass short fiber or hollow glass. The metal hydroxide may be magnesium hydroxide or boehmite type aluminum hydroxide.
　有機充填材を構成する材料としては、例えば、リン酸エステル、ポリエステル、ポリスチレン、パルプ、エラストマー及びこれらの複合材料が挙げられる。有機充填材は、例えば、リン酸エステル、ポリエステル、ポリスチレン、パルプ及びエラストマーからなる群より選択される少なくとも一種を含む態様であってもよい。上記パルプは、パルプフロックの形態であってもよい。有機充填材は、本体部と被覆層との熱膨張差が応力緩和され、クラックが抑制され易くなることから、エラストマーを含有するものであってもよい。 Examples of the material constituting the organic filler include phosphate ester, polyester, polystyrene, pulp, elastomer, and composite materials thereof. For example, the organic filler may include at least one selected from the group consisting of phosphate ester, polyester, polystyrene, pulp, and elastomer. The pulp may be in the form of pulp floc. The organic filler may contain an elastomer because the thermal expansion difference between the main body and the coating layer is relieved of stress and cracks are easily suppressed.
　エラストマーとしては、例えば、スチレン系エラストマー、オレフィン系エラストマー、ウレタン系エラストマー、ポリブタジエン系エラストマー、フッ素系エラストマー及びシリコーン系エラストマーが挙げられる。これらの中でも、耐熱性及び撥水性が更に向上する観点から、エラストマーとして、フッ素系エラストマー又はシリコーン系エラストマーを用いることができる。 Examples of the elastomer include styrene elastomers, olefin elastomers, urethane elastomers, polybutadiene elastomers, fluorine elastomers, and silicone elastomers. Among these, from the viewpoint of further improving heat resistance and water repellency, a fluorine-based elastomer or a silicone-based elastomer can be used as the elastomer.
　被覆層に含まれる充填材の含有量は、耐熱性が更に向上する観点から、被覆層の全体積に対し、０．１体積％以上であってもよい。被覆層に含まれる充填材の含有量は、被覆層を形成するときの作業性が向上する観点、及び、本体部とエアロゲル層との密着性が向上する観点から、被覆層の全体積に対し、７０体積％以下であってもよく、５０体積％以下であってもよく、４０体積％以下であってもよく、３０体積％以下であってもよい。これらの観点から、被覆層に含まれる充填材の含有量は、被覆層の全体積に対し、０．１～７０体積％であってもよく、０．１～５０体積％であってもよく、０．１～４０体積％であってもよく、０．１～３０体積％であってもよい。 The content of the filler contained in the coating layer may be 0.1% by volume or more based on the total volume of the coating layer from the viewpoint of further improving the heat resistance. The content of the filler contained in the coating layer is based on the total volume of the coating layer from the viewpoint of improving workability when forming the coating layer and improving the adhesion between the main body and the airgel layer. 70 volume% or less, 50 volume% or less, 40 volume% or less, or 30 volume% or less. From these viewpoints, the content of the filler contained in the coating layer may be 0.1 to 70% by volume or 0.1 to 50% by volume with respect to the total volume of the coating layer. 0.1 to 40% by volume, or 0.1 to 30% by volume.
　上記被覆層は、例えば、密着性向上剤、難燃剤及び酸化防止剤を含有してもよい。 The coating layer may contain, for example, an adhesion improver, a flame retardant, and an antioxidant.
　密着性向上剤としては、例えば、尿素シラン等の尿素化合物；及びシランカップリング剤が挙げられる。 Examples of the adhesion improver include urea compounds such as urea silane; and silane coupling agents.
　難燃剤としては、例えば、メラミンシアヌレート及びビス（ペンタブロモフェニル）エタンが挙げられる。 Examples of the flame retardant include melamine cyanurate and bis (pentabromophenyl) ethane.
　酸化防止剤としては、例えば、アルミナ、ジルコニア等のセラミックパウダー及び無機バインダからなる酸化防止剤が挙げられる。 Examples of the antioxidant include an antioxidant made of ceramic powder such as alumina and zirconia and an inorganic binder.
　被覆層の熱分解温度は、耐熱性が更に向上する観点から、３００℃以上であってもよい。ここで、熱分解温度が３００℃以上であるとは、材料をＳＩＩ・ナノテクノロジー社製の高温型示差熱熱重量同時測定装置ＴＧ／ＤＴＡ７３００を用いて、窒素雰囲気下、昇温速度１０℃／分の条件で測定した場合に、５％重量減少する時の温度が３００℃以上であることを意味する。 The thermal decomposition temperature of the coating layer may be 300 ° C. or higher from the viewpoint of further improving the heat resistance. Here, the thermal decomposition temperature of 300 ° C. or higher means that the material is heated at a rate of 10 ° C./temperature in a nitrogen atmosphere using a high-temperature differential thermothermal gravimetric measuring device TG / DTA7300 manufactured by SII Nanotechnology. When measured under the condition of minutes, it means that the temperature when the weight is reduced by 5% is 300 ° C. or higher.
　被覆層の厚みは、衝撃等による損傷が低減され、本体部の保護性能が向上する観点、及び、本体部とエアロゲル層との接着性が更に向上する観点から、０．０１μｍ以上であってもよく、０．１μｍ以上であってもよく、１μｍ以上であってもよい。被覆層の厚みは、被覆層の形成時のクラックを抑制する観点から、１０００μｍ以下であってもよく、１０００μｍ未満であってもよく、５００μｍ以下であってもよい。被覆層の厚みは、本体部と被覆層との熱膨張差によるクラックを抑制する観点、及び、熱サイクル安定性が向上する観点から、１００μｍ以下であってもよい。これらの観点から、被覆層の厚みは、０．０１～１０００μｍであってもよく、０．０１～５００μｍであってもよく、０．０１～１００μｍであってもよい。 Even if the thickness of the coating layer is 0.01 μm or more from the viewpoint of reducing damage due to impact and the like, and improving the protection performance of the main body, and further improving the adhesion between the main body and the airgel layer. It may be 0.1 μm or more, or 1 μm or more. From the viewpoint of suppressing cracks during formation of the coating layer, the thickness of the coating layer may be 1000 μm or less, may be less than 1000 μm, or may be 500 μm or less. The thickness of the coating layer may be 100 μm or less from the viewpoint of suppressing cracks due to a difference in thermal expansion between the main body portion and the coating layer and improving the thermal cycle stability. From these viewpoints, the thickness of the coating layer may be 0.01 to 1000 μm, 0.01 to 500 μm, or 0.01 to 100 μm.
　吸水率の低い被覆層を用いることにより、本体部に対する水溶性の酸性物質又は塩基性物質及び無機塩類等の化学的影響を更に低減できる。具体的には、例えば、後述のゾル塗液等の影響による、本体部の化学的変化（腐食、変性等）を更に低減できる。すなわち、エアロゲル層を形成する際の条件及びゾル塗液の組成による影響を受け難く、構造体の製造が容易となる。これらの観点から、被覆層の吸水率は５％未満であってもよく、４％未満であってもよく、３％未満であってもよい。 By using a coating layer having a low water absorption rate, it is possible to further reduce the chemical influence of water-soluble acidic or basic substances and inorganic salts on the main body. Specifically, for example, the chemical change (corrosion, modification, etc.) of the main body due to the influence of a sol coating solution described later can be further reduced. That is, it is difficult to be influenced by the conditions for forming the airgel layer and the composition of the sol coating solution, and the structure can be easily manufactured. From these viewpoints, the water absorption rate of the coating layer may be less than 5%, less than 4%, or less than 3%.
　被覆層の吸水率とは、被覆層の構成材料を２０ｍｍ×２０ｍｍ×０．５ｍｍサイズに成型した試験片を、６０℃、９０％ＲＨの恒温恒湿槽内に６時間放置した際の質量変化率を意味する。 The water absorption rate of the coating layer is a change in mass when a test piece obtained by molding the constituent material of the coating layer into a size of 20 mm × 20 mm × 0.5 mm is left in a constant temperature and humidity chamber at 60 ° C. and 90% RH for 6 hours. Means rate.
　表面粗さが大きい被覆層を用いることにより被覆層とエアロゲル層との密着性を更に向上させることができ、エアロゲル層の剥離及び脱落を更に抑制することができる。被覆層の表面粗さ（Ｒａ）は、被覆層とエアロゲル層との間に良好なアンカー効果が得られ、エアロゲル層の密着性が更に向上する観点から、２００ｎｍ以上であってもよく、３００ｎｍ以上であってもよく、５００ｎｍ以上であってもよい。 By using a coating layer having a large surface roughness, it is possible to further improve the adhesion between the coating layer and the airgel layer, and to further suppress the peeling and dropping of the airgel layer. The surface roughness (Ra) of the coating layer may be 200 nm or more, or 300 nm or more from the viewpoint of obtaining a good anchor effect between the coating layer and the airgel layer and further improving the adhesion of the airgel layer. It may be 500 nm or more.
　被覆層の表面粗さは、例えば、本体部に被覆層を形成した後、当該被覆層に研磨加工（研磨処理）又は粗化加工（粗化処理）を施すことにより調整できる。研磨加工又は粗化加工は、機械的加工であっても、化学的加工であってもよい。加工方法としては、例えば、スラリー又は研磨剤のような砥粒による機械的加工；酸若しくは塩基、酸化剤又は還元剤によるウェットエッチング；及び、六フッ化硫黄又は四フッ化炭素によるドライエッチングが挙げられる。 The surface roughness of the coating layer can be adjusted by, for example, forming a coating layer on the main body and then subjecting the coating layer to polishing (polishing) or roughening (roughening). The polishing process or the roughening process may be a mechanical process or a chemical process. Examples of processing methods include mechanical processing with abrasive grains such as slurry or abrasive; wet etching with acid or base, oxidizing agent or reducing agent; and dry etching with sulfur hexafluoride or carbon tetrafluoride. It is done.
　上記被覆層は、単層であってもよく、複数の層であってもよい。 The coating layer may be a single layer or a plurality of layers.
｛エアロゲル層｝
　本実施形態に係るエアロゲル層は、エアロゲルにより構成されるものであり、ミスト状のゾルから形成されたものである。狭義には、湿潤ゲルに対して超臨界乾燥法を用いて得られた乾燥ゲルをエアロゲル、大気圧下での乾燥により得られた乾燥ゲルをキセロゲル、凍結乾燥により得られた乾燥ゲルをクライオゲルと称するが、本実施形態においては、湿潤ゲルのこれらの乾燥手法によらず、得られた低密度の乾燥ゲルを「エアロゲル」と称する。すなわち、本実施形態において、「エアロゲル」とは、広義のエアロゲルである「Ｇｅｌ　ｃｏｍｐｒｉｓｅｄ　ｏｆ　ａ　ｍｉｃｒｏｐｏｒｏｕｓ　ｓｏｌｉｄ　ｉｎ　ｗｈｉｃｈ　ｔｈｅ　ｄｉｓｐｅｒｓｅｄ　ｐｈａｓｅ　ｉｓ　ａ　ｇａｓ（分散相が気体である微多孔性固体から構成されるゲル）」を意味する。一般的に、エアロゲルの内部は、網目状の微細構造を有しており、２～２０ｎｍ程度のエアロゲル粒子（エアロゲルを構成する粒子）が結合したクラスター構造を有している。このクラスターにより形成される骨格間には、１００ｎｍに満たない細孔がある。これにより、エアロゲルは、三次元的に微細な多孔性の構造を有している。なお、本実施形態におけるエアロゲルは、例えば、シリカを主成分とするシリカエアロゲルである。シリカエアロゲルとしては、例えば、有機基（メチル基等）又は有機鎖を導入した、いわゆる有機－無機ハイブリッド化されたシリカエアロゲルが挙げられる。エアロゲル層は、ポリシロキサン由来の構造を有するエアロゲルを含有する層であってもよい。 {Airgel layer}
The airgel layer according to the present embodiment is made of airgel and is formed from a mist-like sol. In a narrow sense, dry gel obtained by using supercritical drying method for wet gel is aerogel, dry gel obtained by drying under atmospheric pressure is xerogel, dry gel obtained by freeze-drying is cryogel and However, in the present embodiment, the obtained low-density dried gel is referred to as “aerogel” regardless of the drying method of the wet gel. That is, in this embodiment, “aerogel” is a gel in a broad sense, “Gel composed of a microporous solid in which the dispersed phase is a gas” (a gel composed of a microporous solid in which the dispersed phase is a gas). "Means. In general, the inside of the airgel has a network-like fine structure, and has a cluster structure in which airgel particles of about 2 to 20 nm (particles constituting the airgel) are combined. There are pores less than 100 nm between the skeletons formed by these clusters. Thereby, the airgel has a three-dimensionally fine porous structure. In addition, the airgel in this embodiment is a silica airgel which has a silica as a main component, for example. Examples of the silica airgel include so-called organic-inorganic hybrid silica airgel into which an organic group (such as a methyl group) or an organic chain is introduced. The airgel layer may be a layer containing an airgel having a structure derived from polysiloxane.
　本実施形態に係るエアロゲルは、断熱性に優れる観点及び特異な電気特性を発揮する観点から、例えば、気体の平均自由行程よりも小さい空孔を有していてもよい。本実施形態に係るエアロゲルの１次粒子径は、特異な光学特性を発揮する観点から、例えば、数ｎｍ程度であってもよい。 The aerogel according to the present embodiment may have, for example, pores smaller than the mean free path of gas from the viewpoint of excellent heat insulation and a unique electrical characteristic. The primary particle diameter of the airgel according to the present embodiment may be, for example, about several nm from the viewpoint of exhibiting unique optical characteristics.
　本実施形態に係るエアロゲルは、（分子内に）加水分解性の官能基又は縮合性の官能基を有するケイ素化合物、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物からなる群より選択される少なくとも一種を含有するゾルの縮合物である湿潤ゲルの乾燥物であってもよい。すなわち、本実施形態に係るエアロゲルは、（分子内に）加水分解性の官能基又は縮合性の官能基を有するケイ素化合物、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物からなる群より選択される少なくとも一種を含有するゾルから生成された湿潤ゲルを乾燥して得られるものであってもよい。これらの態様を採用することにより、断熱性と柔軟性とが更に向上する。前記縮合物は、加水分解性の官能基を有するケイ素化合物の加水分解により得られた加水分解生成物の縮合反応により得られてもよく、加水分解により得られた官能基ではない縮合性の官能基を有するケイ素化合物の縮合反応により得られてもよい。前記ケイ素化合物は、加水分解性の官能基及び縮合性の官能基の少なくとも一方を有していればよく、加水分解性の官能基及び縮合性の官能基の双方を有していてもよい。なお、後述する各エアロゲルは、このように、加水分解性の官能基又は縮合性の官能基を有するケイ素化合物、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物からなる群より選択される少なくとも一種を含有するゾルの縮合物である湿潤ゲルの乾燥物（前記ゾルから生成された湿潤ゲルを乾燥することで得られるもの）であってもよい。 The airgel according to the present embodiment includes a silicon compound having a hydrolyzable functional group or a condensable functional group (in the molecule) and a hydrolysis product of the silicon compound having the hydrolyzable functional group. It may be a dried product of a wet gel that is a condensate of a sol containing at least one selected from the group. That is, the airgel according to the present embodiment includes a hydrolyzable functional group or a silicon compound having a condensable functional group (in the molecule) and a hydrolysis product of the silicon compound having the hydrolyzable functional group. It may be obtained by drying a wet gel produced from a sol containing at least one selected from the group consisting of: By adopting these aspects, the heat insulation and flexibility are further improved. The condensate may be obtained by a condensation reaction of a hydrolysis product obtained by hydrolysis of a silicon compound having a hydrolyzable functional group, and is not a functional group obtained by hydrolysis. It may be obtained by a condensation reaction of a silicon compound having a group. The silicon compound may have at least one of a hydrolyzable functional group and a condensable functional group, and may have both a hydrolyzable functional group and a condensable functional group. In addition, each airgel mentioned later is a group which consists of a hydrolysis product of the silicon compound which has a hydrolyzable functional group or a condensable functional group, and the said hydrolyzable functional group in this way. It may be a dried product of a wet gel that is a condensate of a sol containing at least one selected from the above (obtained by drying a wet gel produced from the sol).
　また、このようなエアロゲルは、断熱性に優れるとともに、極めて屈折率が低いと考えられる。したがって、例えば、断熱材料、光反射材料等に用いることができると考えられる。 Further, such an airgel is considered to have excellent heat insulation and a very low refractive index. Therefore, for example, it is considered that it can be used for a heat insulating material, a light reflecting material, and the like.
　従来のシリカエアロゲルは、一般的に親水性であるため、吸水し易く、これによりエアロゲルとしての機能が低下し易いと考えられる。本実施形態に係るエアロゲル（加水分解性の官能基又は縮合性の官能基を有するケイ素化合物、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物からなる群より選択される少なくとも一種を含有するゾルから形成されるエアロゲル）は、吸水による機能低下が生じ難いと考えられる。 Since conventional silica airgel is generally hydrophilic, it is likely to absorb water, and thus the function as an airgel is likely to be lowered. Airgel according to the present embodiment (at least selected from the group consisting of hydrolyzable functional groups or silicon compounds having a condensable functional group, and hydrolysis products of silicon compounds having the hydrolyzable functional group) It is considered that an airgel formed from a sol containing one kind is unlikely to deteriorate in function due to water absorption.
　エアロゲル層は、加水分解性の官能基又は縮合性の官能基を有するケイ素化合物、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物からなる群より選択される少なくとも一種を含有するゾルの縮合物である湿潤ゲルの乾燥物から構成される層であってもよい。すなわち、エアロゲル層は、加水分解性の官能基又は縮合性の官能基を有するケイ素化合物、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物からなる群より選択される少なくとも一種を含有するゾルから生成された湿潤ゲルを乾燥してなる層で構成されていてもよい。 The airgel layer contains at least one selected from the group consisting of a hydrolyzable functional group or a silicon compound having a condensable functional group, and a hydrolysis product of the silicon compound having the hydrolyzable functional group. It may be a layer composed of a dried product of a wet gel that is a condensate of the sol. That is, the airgel layer is at least one selected from the group consisting of a hydrolyzable functional group or a silicon compound having a condensable functional group, and a hydrolysis product of the silicon compound having the hydrolyzable functional group. It may be composed of a layer formed by drying a wet gel produced from a sol containing.
　本実施形態に係るエアロゲルは、シロキサン結合（Ｓｉ－Ｏ－Ｓｉ）を含む主鎖を有するポリシロキサンを含有することができる。エアロゲルは、構造単位として、下記Ｍ単位、Ｄ単位、Ｔ単位又はＱ単位を有することができる。 The airgel according to the present embodiment can contain polysiloxane having a main chain including a siloxane bond (Si—O—Si). The airgel can have the following M unit, D unit, T unit or Q unit as a structural unit.
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
　上記式中、Ｒは、ケイ素原子に結合している原子（水素原子等）又は原子団（アルキル基等）を示す。Ｍ単位は、ケイ素原子が１個の酸素原子と結合した一価の基からなる単位である。Ｄ単位は、ケイ素原子が２個の酸素原子と結合した二価の基からなる単位である。Ｔ単位は、ケイ素原子が３個の酸素原子と結合した三価の基からなる単位である。Ｑ単位は、ケイ素原子が４個の酸素原子と結合した四価の基からなる単位である。これらの単位の含有量に関する情報は、Ｓｉ－ＮＭＲにより得ることができる。 In the above formula, R represents an atom (hydrogen atom or the like) or an atomic group (alkyl group or the like) bonded to a silicon atom. The M unit is a unit composed of a monovalent group in which a silicon atom is bonded to one oxygen atom. The D unit is a unit composed of a divalent group in which a silicon atom is bonded to two oxygen atoms. The T unit is a unit composed of a trivalent group in which a silicon atom is bonded to three oxygen atoms. The Q unit is a unit composed of a tetravalent group in which a silicon atom is bonded to four oxygen atoms. Information on the content of these units can be obtained by Si-NMR.
　本実施形態に係るエアロゲルは、シルセスキオキサンを含有していてもよい。シルセスキオキサンは、構造単位として上記Ｔ単位を有するポリシロキサンであり、組成式：（ＲＳｉＯ１．５）ｎを有する。シルセスキオキサンは、カゴ型、ラダー型、ランダム型等の種々の骨格構造を有することができる。 The airgel according to the present embodiment may contain silsesquioxane. Silsesquioxane is a polysiloxane having the above T unit as a structural unit, and has a composition formula: (RSiO 1.5 ) n . Silsesquioxane can have various skeletal structures such as a cage type, a ladder type, and a random type.
　加水分解性の官能基としては、例えば、アルコキシ基が挙げられる。縮合性の官能基（加水分解性の官能基に該当する官能基を除く）としては、例えば、水酸基、シラノール基、カルボキシル基及びフェノール性水酸基が挙げられる。水酸基は、ヒドロキシアルキル基等の水酸基含有基に含まれていてもよい。加水分解性の官能基及び縮合性の官能基のそれぞれは、単独で又は２種類以上を混合して用いてもよい。 Examples of the hydrolyzable functional group include an alkoxy group. Examples of the condensable functional group (excluding the functional group corresponding to the hydrolyzable functional group) include a hydroxyl group, a silanol group, a carboxyl group, and a phenolic hydroxyl group. The hydroxyl group may be contained in a hydroxyl group-containing group such as a hydroxyalkyl group. Each of the hydrolyzable functional group and the condensable functional group may be used alone or in admixture of two or more.
　ケイ素化合物は、加水分解性の官能基としてアルコキシ基を有するケイ素化合物を含むことが可能であり、また、縮合性の官能基としてヒドロキシアルキル基を有するケイ素化合物を含むことができる。ケイ素化合物は、エアロゲルの柔軟性が更に向上する観点から、アルコキシ基、シラノール基、ヒドロキシアルキル基及びポリエーテル基からなる群より選ばれる少なくとも１種を有することができる。ケイ素化合物は、ゾルの相溶性が向上する観点から、アルコキシ基及びヒドロキシアルキル基からなる群より選ばれる少なくとも１種を有することができる。 The silicon compound can include a silicon compound having an alkoxy group as a hydrolyzable functional group, and can also include a silicon compound having a hydroxyalkyl group as a condensable functional group. The silicon compound can have at least one selected from the group consisting of an alkoxy group, a silanol group, a hydroxyalkyl group and a polyether group from the viewpoint of further improving the flexibility of the airgel. The silicon compound can have at least one selected from the group consisting of an alkoxy group and a hydroxyalkyl group from the viewpoint of improving the compatibility of the sol.
　ケイ素化合物の反応性の向上とエアロゲルの熱伝導率の低減の観点から、アルコキシ基及びヒドロキシアルキル基のそれぞれの炭素数は、１～６とすることができ、エアロゲルの柔軟性が更に向上する観点から２～４であってもよい。アルコキシ基としては、メトキシ基、エトキシ基、プロポキシ基等が挙げられる。ヒドロキシアルキル基としては、ヒドロキシメチル基、ヒドロキシエチル基、ヒドロキシプロピル基等が挙げられる。 From the viewpoint of improving the reactivity of the silicon compound and reducing the thermal conductivity of the airgel, the number of carbon atoms of the alkoxy group and the hydroxyalkyl group can be 1 to 6, and the viewpoint of further improving the flexibility of the airgel 2 to 4. Examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group. Examples of the hydroxyalkyl group include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
　本実施形態に係るエアロゲルとしては、以下の態様が挙げられる。これらの態様を採用することにより、撥水性と柔軟性とに優れるエアロゲルを得ることが容易となる。各々の態様を採用することで、各々の態様に応じた撥水性と柔軟性とを有するエアロゲルを得ることができる。 Examples of the airgel according to the present embodiment include the following modes. By adopting these aspects, it becomes easy to obtain an airgel excellent in water repellency and flexibility. By employing each aspect, an airgel having water repellency and flexibility according to each aspect can be obtained.
（第一の態様）
　本実施形態に係るエアロゲルは、（分子内に）加水分解性の官能基又は縮合性の官能基を有するポリシロキサン化合物、及び、前記加水分解性の官能基を有するポリシロキサン化合物の加水分解生成物（前記加水分解性の官能基が加水分解したポリシロキサン化合物）からなる群より選択される少なくとも一種の化合物（以下、場合により「ポリシロキサン化合物群」という）を含有するゾルの縮合物である湿潤ゲルの乾燥物であってもよい。例えば、本実施形態に係るエアロゲルは、（分子内に）加水分解性の官能基又は縮合性の官能基を有するポリシロキサン化合物、及び、前記加水分解性の官能基を有するポリシロキサン化合物の加水分解生成物からなる群より選択される少なくとも一種を含有するゾルから生成された湿潤ゲルを乾燥して得られるものであってもよい。すなわち、エアロゲル層は、（分子内に）加水分解性の官能基又は縮合性の官能基を有するポリシロキサン化合物、及び、前記加水分解性の官能基を有するポリシロキサン化合物の加水分解生成物からなる群より選択される少なくとも一種を含有するゾルから形成されるものであってもよい。なお、後述する各エアロゲルも、このように、加水分解性の官能基又は縮合性の官能基を有するポリシロキサン化合物、及び、前記加水分解性の官能基を有するポリシロキサン化合物の加水分解生成物からなる群より選択される少なくとも一種を含有するゾルの縮合物である湿潤ゲルの乾燥物（前記ゾルから生成された湿潤ゲルを乾燥することで得られるもの）であってもよい。 (First aspect)
The airgel according to the present embodiment includes a polysiloxane compound having a hydrolyzable functional group or a condensable functional group (in the molecule), and a hydrolysis product of the polysiloxane compound having the hydrolyzable functional group. Wet which is a condensate of sol containing at least one compound selected from the group consisting of (the hydrolyzable functional group hydrolyzed polysiloxane compound) (hereinafter sometimes referred to as “polysiloxane compound group”) It may be a dried gel. For example, the airgel according to the present embodiment includes a hydrolyzable functional group or a polysiloxane compound having a condensable functional group (in the molecule) and hydrolysis of the polysiloxane compound having the hydrolyzable functional group. It may be obtained by drying a wet gel produced from a sol containing at least one selected from the group consisting of products. That is, the airgel layer is composed of a polysiloxane compound having a hydrolyzable functional group or a condensable functional group (in the molecule) and a hydrolysis product of the polysiloxane compound having the hydrolyzable functional group. It may be formed from a sol containing at least one selected from the group. In addition, each airgel mentioned later is also from the hydrolysis product of the polysiloxane compound which has a hydrolyzable functional group or a condensable functional group, and the polysiloxane compound which has the said hydrolyzable functional group in this way. It may be a wet gel dried product (obtained by drying a wet gel generated from the sol), which is a condensate of a sol containing at least one selected from the group.
　エアロゲル層は、加水分解性の官能基又は縮合性の官能基を有するポリシロキサン化合物、及び、前記加水分解性の官能基を有するポリシロキサン化合物の加水分解生成物からなる群より選択される少なくとも一種を含有するゾルの縮合物である湿潤ゲルの乾燥物から構成される層であってもよい。すなわち、エアロゲル層は、加水分解性の官能基又は縮合性の官能基を有するポリシロキサン化合物、及び、前記加水分解性の官能基を有するポリシロキサン化合物の加水分解生成物からなる群より選択される少なくとも一種を含有するゾルから生成された湿潤ゲルを乾燥してなる層で構成されていてもよい。 The airgel layer is at least one selected from the group consisting of a hydrolyzable functional group or a polysiloxane compound having a condensable functional group, and a hydrolysis product of the polysiloxane compound having a hydrolyzable functional group. It may be a layer composed of a dried product of a wet gel that is a condensate of sol containing That is, the airgel layer is selected from the group consisting of a hydrolyzable functional group or a polysiloxane compound having a condensable functional group, and a hydrolysis product of the polysiloxane compound having a hydrolyzable functional group. You may be comprised by the layer formed by drying the wet gel produced | generated from the sol containing at least 1 type.
　加水分解性の官能基又は縮合性の官能基を有するポリシロキサン化合物は、加水分解性の官能基及び縮合性の官能基とは異なる反応性基（加水分解性の官能基及び縮合性の官能基に該当しない官能基）を更に有していてもよい。反応性基としては、特に限定されないが、例えば、エポキシ基、メルカプト基、グリシドキシ基、ビニル基、アクリロイル基、メタクリロイル基及びアミノ基が挙げられる。エポキシ基は、グリシドキシ基等のエポキシ基含有基に含まれていてもよい。前記反応性基を有するポリシロキサン化合物は、単独で又は２種類以上を混合して用いてもよい。 A polysiloxane compound having a hydrolyzable functional group or a condensable functional group is a reactive group different from the hydrolyzable functional group and the condensable functional group (hydrolyzable functional group and condensable functional group). May further have a functional group that does not fall under. The reactive group is not particularly limited, and examples thereof include an epoxy group, a mercapto group, a glycidoxy group, a vinyl group, an acryloyl group, a methacryloyl group, and an amino group. The epoxy group may be contained in an epoxy group-containing group such as a glycidoxy group. You may use the polysiloxane compound which has the said reactive group individually or in mixture of 2 or more types.
　ヒドロキシアルキル基を有するポリシロキサン化合物としては、例えば、下記一般式（Ａ）で表される構造を有する化合物が挙げられる。 Examples of the polysiloxane compound having a hydroxyalkyl group include compounds having a structure represented by the following general formula (A).
Figure JPOXMLDOC01-appb-C000002
Figure JPOXMLDOC01-appb-C000002
　式（Ａ）中、Ｒ１ａはヒドロキシアルキル基を示し、Ｒ２ａはアルキレン基を示し、Ｒ３ａ及びＲ４ａはそれぞれ独立にアルキル基又はアリール基を示し、ｎは１～５０の整数を示す。ここで、アリール基としては、例えばフェニル基及び置換フェニル基が挙げられる。置換フェニル基の置換基としては、例えばアルキル基、ビニル基、メルカプト基、アミノ基、ニトロ基及びシアノ基が挙げられる。式（Ａ）中、２個のＲ１ａは各々同一であっても異なっていてもよく、同様に、２個のＲ２ａは各々同一であっても異なっていてもよい。式（Ａ）中、２個以上のＲ３ａは各々同一であっても異なっていてもよく、同様に、２個以上のＲ４ａは各々同一であっても異なっていてもよい。 In formula (A), R 1a represents a hydroxyalkyl group, R 2a represents an alkylene group, R 3a and R 4a each independently represents an alkyl group or an aryl group, and n represents an integer of 1 to 50. Here, examples of the aryl group include a phenyl group and a substituted phenyl group. Examples of the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, and a cyano group. In formula (A), two R 1a s may be the same or different, and similarly, two R 2a s may be the same or different. In formula (A), two or more R 3a s may be the same or different, and similarly, two or more R 4a s may be the same or different.
　上記構造のポリシロキサン化合物を含有するゾルの縮合物である湿潤ゲル（前記ゾルから生成された湿潤ゲル）を用いることにより、撥水性に優れると共に、低熱伝導率かつ柔軟なエアロゲルを更に得易くなる。同様の観点から、以下に示す特徴を満たしてもよい。式（Ａ）中、Ｒ１ａとしては、例えば、炭素数が１～６のヒドロキシアルキル基が挙げられ、具体的には、ヒドロキシエチル基及びヒドロキシプロピル基が挙げられる。式（Ａ）中、Ｒ２ａとしては、例えば、炭素数が１～６のアルキレン基が挙げられ、具体的には、エチレン基及びプロピレン基が挙げられる。式（Ａ）中、Ｒ３ａ及びＲ４ａはそれぞれ独立に炭素数が１～６のアルキル基又はフェニル基であってもよい。当該アルキル基は、メチル基であってもよい。式（Ａ）中、ｎは２～３０であってもよく、５～２０であってもよい。 By using a wet gel that is a condensate of a sol containing a polysiloxane compound having the above structure (wet gel generated from the sol), it is excellent in water repellency, and it is easier to obtain a flexible airgel with low thermal conductivity. . From the same viewpoint, the following features may be satisfied. In formula (A), examples of R 1a include a hydroxyalkyl group having 1 to 6 carbon atoms, and specific examples include a hydroxyethyl group and a hydroxypropyl group. In the formula (A), examples of R 2a include an alkylene group having 1 to 6 carbon atoms, and specific examples include an ethylene group and a propylene group. In the formula (A), R 3a and R 4a may each independently be an alkyl group having 1 to 6 carbon atoms or a phenyl group. The alkyl group may be a methyl group. In the formula (A), n may be 2 to 30, or 5 to 20.
　上記一般式（Ａ）で表される構造を有するポリシロキサン化合物としては、市販品を用いることができ、例えば、Ｘ－２２－１６０ＡＳ、ＫＦ－６００１、ＫＦ－６００２、ＫＦ－６００３等の化合物（いずれも、信越化学工業株式会社製）、及び、ＸＦ４２－Ｂ０９７０、Ｆｌｕｉｄ　ＯＦＯＨ　７０２－４％等の化合物（いずれも、モメンティブ社製）が挙げられる。 As the polysiloxane compound having the structure represented by the general formula (A), commercially available products can be used. For example, compounds such as X-22-160AS, KF-6001, KF-6002, KF-6003 and the like ( All of which are manufactured by Shin-Etsu Chemical Co., Ltd.) and compounds such as XF42-B0970, Fluid OFOH 702-4% (all manufactured by Momentive).
　アルコキシ基を有するポリシロキサン化合物としては、例えば、下記一般式（Ｂ）で表される構造を有する化合物が挙げられる。 Examples of the polysiloxane compound having an alkoxy group include compounds having a structure represented by the following general formula (B).
Figure JPOXMLDOC01-appb-C000003
Figure JPOXMLDOC01-appb-C000003
　式（Ｂ）中、Ｒ１ｂはアルキル基、アルコキシ基又はアリール基を示し、Ｒ２ｂ及びＲ３ｂはそれぞれ独立にアルコキシ基を示し、Ｒ４ｂ及びＲ５ｂはそれぞれ独立にアルキル基又はアリール基を示し、ｍは１～５０の整数を示す。ここで、アリール基としては、例えばフェニル基及び置換フェニル基が挙げられる。置換フェニル基の置換基としては、例えばアルキル基、ビニル基、メルカプト基、アミノ基、ニトロ基及びシアノ基が挙げられる。なお、式（Ｂ）中、２個のＲ１ｂは各々同一であっても異なっていてもよく、２個のＲ２ｂは各々同一であっても異なっていてもよく、同様に、２個のＲ３ｂは各々同一であっても異なっていてもよい。式（Ｂ）中、ｍが２以上の整数の場合、２個以上のＲ４ｂは各々同一であっても異なっていてもよく、同様に、２個以上のＲ５ｂは各々同一であっても異なっていてもよい。 In formula (B), R 1b represents an alkyl group, an alkoxy group or an aryl group, R 2b and R 3b each independently represent an alkoxy group, and R 4b and R 5b each independently represent an alkyl group or an aryl group. , M represents an integer of 1 to 50. Here, examples of the aryl group include a phenyl group and a substituted phenyl group. Examples of the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, and a cyano group. In the formula (B), two R 1b s may be the same or different, and two R 2b s may be the same or different. Similarly, R 3b may be the same or different. In the formula (B), when m is an integer of 2 or more, two or more R 4b may be the same or different, and similarly, two or more R 5b may be the same. May be different.
　上記構造のポリシロキサン化合物又はその加水分解生成物を含有するゾルの縮合物である湿潤ゲル（前記ゾルから生成された湿潤ゲル）を用いることにより、低熱伝導率かつ柔軟なエアロゲルを更に得易くなる。同様の観点から、以下に示す特徴を満たしてもよい。式（Ｂ）中、Ｒ１ｂとしては、例えば、炭素数が１～６のアルキル基及び炭素数が１～６のアルコキシ基が挙げられ、具体的には、メチル基、メトキシ基及びエトキシ基が挙げられる。式（Ｂ）中、Ｒ２ｂ及びＲ３ｂは、それぞれ独立に炭素数が１～６のアルコキシ基であってもよい。当該アルコキシ基としては、例えばメトキシ基及びエトキシ基が挙げられる。式（Ｂ）中、Ｒ４ｂ及びＲ５ｂは、それぞれ独立に炭素数が１～６のアルキル基又はフェニル基であってもよい。当該アルキル基は、メチル基であってもよい。式（Ｂ）中、ｍは２～３０であってもよく、５～２０であってもよい。 By using a wet gel (wet gel generated from the sol) that is a condensate of a sol containing the polysiloxane compound having the above structure or a hydrolysis product thereof, it becomes easier to obtain a flexible airgel having low thermal conductivity. . From the same viewpoint, the following features may be satisfied. In the formula (B), examples of R 1b include an alkyl group having 1 to 6 carbon atoms and an alkoxy group having 1 to 6 carbon atoms. Specifically, a methyl group, a methoxy group, and an ethoxy group can be exemplified. Can be mentioned. In the formula (B), R 2b and R 3b may each independently be an alkoxy group having 1 to 6 carbon atoms. Examples of the alkoxy group include a methoxy group and an ethoxy group. In the formula (B), R 4b and R 5b may each independently be an alkyl group having 1 to 6 carbon atoms or a phenyl group. The alkyl group may be a methyl group. In the formula (B), m may be 2 to 30, or 5 to 20.
　上記一般式（Ｂ）で表される構造を有するポリシロキサン化合物は、例えば、特開２０００－２６６０９号公報、特開２０１２－２３３１１０号公報等にて報告される製造方法を適宜参照して得ることができる。 The polysiloxane compound having the structure represented by the general formula (B) can be obtained by appropriately referring to the production methods reported in, for example, JP-A Nos. 2000-26609 and 2012-233110. Can do.
　なお、アルコキシ基は加水分解するため、アルコキシ基を有するポリシロキサン化合物はゾル中にて加水分解生成物として存在する可能性があり、アルコキシ基を有するポリシロキサン化合物と、その加水分解生成物とは混在していてもよい。また、アルコキシ基を有するポリシロキサン化合物において、分子中のアルコキシ基の全てが加水分解されていてもよいし、部分的に加水分解されていてもよい。 In addition, since the alkoxy group is hydrolyzed, the polysiloxane compound having an alkoxy group may exist as a hydrolysis product in the sol. The polysiloxane compound having an alkoxy group and the hydrolysis product are It may be mixed. In the polysiloxane compound having an alkoxy group, all of the alkoxy groups in the molecule may be hydrolyzed or partially hydrolyzed.
　加水分解性の官能基又は縮合性の官能基を有するポリシロキサン化合物、及び、前記加水分解性の官能基を有するポリシロキサン化合物の加水分解生成物のそれぞれは、単独で又は２種類以上を混合して用いてもよい。 Each of the hydrolyzable functional group or the polysiloxane compound having a condensable functional group and the hydrolysis product of the polysiloxane compound having the hydrolyzable functional group may be used alone or in combination of two or more. May be used.
　上記ゾルに含まれるポリシロキサン化合物群の含有量（加水分解性の官能基又は縮合性の官能基を有するポリシロキサン化合物の含有量、及び、前記加水分解性の官能基を有するポリシロキサン化合物の加水分解生成物の含有量の総和）は、良好な反応性を更に得易くなる観点から、ゾルの総量１００質量部に対し、１質量部以上であってもよく、３質量部以上であってもよく、４質量部以上であってもよく、５質量部以上であってもよく、７質量部以上であってもよく、１０質量部以上であってもよい。ポリシロキサン化合物群の前記含有量は、良好な相溶性を更に得易くなる観点から、ゾルの総量１００質量部に対し、５０質量部以下であってもよく、３０質量部以下であってもよく、１５質量部以下であってもよい。これらの観点から、ポリシロキサン化合物群の前記含有量は、ゾルの総量１００質量部に対し、１～５０質量部であってもよく、３～５０質量部であってもよく、４～５０質量部であってもよく、５～５０質量部であってもよく、７～３０質量部であってもよく、１０～３０質量部であってもよく、１０～１５質量部であってもよい。 Content of polysiloxane compound group contained in the sol (content of polysiloxane compound having hydrolyzable functional group or condensable functional group, and water content of polysiloxane compound having hydrolyzable functional group) The total content of the decomposition products) may be 1 part by mass or 3 parts by mass or more with respect to 100 parts by mass of the total amount of sol, from the viewpoint of further easily obtaining good reactivity. Alternatively, it may be 4 parts by mass or more, 5 parts by mass or more, 7 parts by mass or more, or 10 parts by mass or more. The content of the polysiloxane compound group may be 50 parts by mass or less, or 30 parts by mass or less with respect to 100 parts by mass of the total amount of sol, from the viewpoint of further easily obtaining good compatibility. 15 parts by mass or less. From these viewpoints, the content of the polysiloxane compound group may be 1 to 50 parts by mass, 3 to 50 parts by mass, or 4 to 50 parts by mass based on 100 parts by mass of the sol. Part, 5 to 50 parts by weight, 7 to 30 parts by weight, 10 to 30 parts by weight, or 10 to 15 parts by weight. .
［第二の態様］
　加水分解性の官能基又は縮合性の官能基を有するケイ素化合物としては、ポリシロキサン化合物以外のケイ素化合物（シリコン化合物）を用いてもよい。すなわち、本実施形態に係るエアロゲルは、（分子内に）加水分解性の官能基又は縮合性の官能基を有するケイ素化合物（ポリシロキサン化合物を除く）、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物からなる群より選択される少なくとも一種の化合物（以下、場合により「ケイ素化合物群」という）を含有するゾルの縮合物である湿潤ゲルの乾燥物であってもよい。前記ケイ素化合物における分子内のケイ素数は、１又は２であってもよい。 [Second embodiment]
As the silicon compound having a hydrolyzable functional group or a condensable functional group, a silicon compound (silicon compound) other than the polysiloxane compound may be used. That is, the airgel according to the present embodiment has (in the molecule) a hydrolyzable functional group or a silicon compound having a condensable functional group (excluding a polysiloxane compound) and the hydrolyzable functional group. It may be a wet gel dried product which is a condensate of sol containing at least one compound selected from the group consisting of hydrolysis products of silicon compounds (hereinafter sometimes referred to as “silicon compound group”). The number of silicon atoms in the molecule of the silicon compound may be 1 or 2.
　加水分解性の官能基を有するケイ素化合物としては、特に限定されないが、例えば、アルキルケイ素アルコキシドが挙げられる。アルキルケイ素アルコキシドにおいて、撥水性が向上する観点から、加水分解性の官能基の数は、３個以下であってもよく、２～３個であってもよい。アルキルケイ素アルコキシドとしては、例えば、モノアルキルトリアルコキシシラン、モノアルキルジアルコキシシラン、ジアルキルジアルコキシシラン、モノアルキルモノアルコキシシラン、ジアルキルモノアルコキシシラン及びトリアルキルモノアルコキシシランが挙げられる。アルキルケイ素アルコキシドとしては、例えば、メチルトリメトキシシラン、メチルジメトキシシラン、ジメチルジメトキシシラン、ジメチルジエトキシシラン、エチルトリメトキシシラン及びヘキシルトリメトキシシランが挙げられる。 The silicon compound having a hydrolyzable functional group is not particularly limited, and examples thereof include alkyl silicon alkoxides. In the alkyl silicon alkoxide, from the viewpoint of improving water repellency, the number of hydrolyzable functional groups may be 3 or less, or 2 to 3. Examples of the alkyl silicon alkoxide include monoalkyltrialkoxysilane, monoalkyldialkoxysilane, dialkyldialkoxysilane, monoalkylmonoalkoxysilane, dialkylmonoalkoxysilane and trialkylmonoalkoxysilane. Examples of the alkyl silicon alkoxide include methyltrimethoxysilane, methyldimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, ethyltrimethoxysilane, and hexyltrimethoxysilane.
　縮合性の官能基を有するケイ素化合物としては、特に限定されないが、例えば、シランテトラオール、メチルシラントリオール、ジメチルシランジオール、フェニルシラントリオール、フェニルメチルシランジオール、ジフェニルシランジオール、ｎ－プロピルシラントリオール、ヘキシルシラントリオール、オクチルシラントリオール、デシルシラントリオール及びトリフルオロプロピルシラントリオールが挙げられる。 The silicon compound having a condensable functional group is not particularly limited. For example, silane tetraol, methyl silane triol, dimethyl silane diol, phenyl silane triol, phenyl methyl silane diol, diphenyl silane diol, n-propyl silane triol, Examples include hexyl silane triol, octyl silane triol, decyl silane triol, and trifluoropropyl silane triol.
　加水分解性の官能基の数が３個以下であり、反応性基を有するケイ素化合物として、ビニルトリメトキシシラン、３－グリシドキシプロピルトリメトキシシラン、３－グリシドキシプロピルメチルジメトキシシラン、３－メタクリロキシプロピルトリメトキシシラン、３－メタクリロキシプロピルメチルジメトキシシラン、３－アクリロキシプロピルトリメトキシシラン、３－メルカプトプロピルトリメトキシシラン、３－メルカプトプロピルメチルジメトキシシラン、Ｎ－フェニル－３－アミノプロピルトリメトキシシラン、Ｎ－２－（アミノエチル）－３－アミノプロピルメチルジメトキシシラン等も用いることができる。 The number of hydrolyzable functional groups is 3 or less, and silicon compounds having reactive groups include vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3 -Methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, N-phenyl-3-aminopropyl Trimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, and the like can also be used.
　縮合性の官能基を有し、前述の反応性基を有するケイ素化合物として、ビニルシラントリオール、３－グリシドキシプロピルシラントリオール、３－グリシドキシプロピルメチルシランジオール、３－メタクリロキシプロピルシラントリオール、３－メタクリロキシプロピルメチルシランジオール、３－アクリロキシプロピルシラントリオール、３－メルカプトプロピルシラントリオール、３－メルカプトプロピルメチルシランジオール、Ｎ－フェニル－３－アミノプロピルシラントリオール、Ｎ－２－（アミノエチル）－３－アミノプロピルメチルシランジオール等も用いることができる。 As a silicon compound having a condensable functional group and having the above-mentioned reactive group, vinylsilane triol, 3-glycidoxypropylsilanetriol, 3-glycidoxypropylmethylsilanediol, 3-methacryloxypropylsilanetriol, 3-methacryloxypropylmethylsilanediol, 3-acryloxypropylsilanetriol, 3-mercaptopropylsilanetriol, 3-mercaptopropylmethylsilanediol, N-phenyl-3-aminopropylsilanetriol, N-2- (aminoethyl ) -3-Aminopropylmethylsilanediol and the like can also be used.
　アルキルケイ素アルコキシドとしては、分子末端の加水分解性の官能基の数が３個を超えるケイ素化合物であるビストリメトキシシリルメタン、ビストリメトキシシリルエタン、ビストリメトキシシリルヘキサン、ビストリメトキシシリルオクタン等を用いることもできる。 As the alkyl silicon alkoxide, bistrimethoxysilylmethane, bistrimethoxysilylethane, bistrimethoxysilylhexane, bistrimethoxysilyloctane or the like which is a silicon compound having more than three hydrolyzable functional groups at the molecular terminals may be used. it can.
　加水分解性の官能基又は縮合性の官能基を有するケイ素化合物（ポリシロキサン化合物を除く）、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物のそれぞれは、単独で又は２種類以上を混合して用いてもよい。 Each of the hydrolyzable functional group or the silicon compound having a condensable functional group (excluding the polysiloxane compound) and the hydrolyzate of the silicon compound having the hydrolyzable functional group, either alone or 2 You may mix and use a kind or more.
　良好な反応性を更に得易くなることから、上記ゾルに含まれるケイ素化合物群の含有量（加水分解性の官能基又は縮合性の官能基を有するケイ素化合物（ポリシロキサン化合物を除く）の含有量、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物の含有量の総和）は、ゾルの総量１００質量部に対し、５質量部以上であってもよく、１０質量部以上であってもよく、１２質量部以上であってもよく、１５質量部以上であってもよく、１８質量部以上であってもよい。良好な相溶性を更に得易くなることから、ケイ素化合物群の前記含有量は、ゾルの総量１００質量部に対し、５０質量部以下であってもよく、３０質量部以下であってもよく、２５質量部以下であってもよく、２０質量部以下であってもよい。すなわち、ケイ素化合物群の前記含有量は、ゾルの総量１００質量部に対し、５～５０質量部であってもよく、１０～３０質量部であってもよく、１２～３０質量部であってもよく、１５～２５質量部であってもよく、１８～２０質量部であってもよい。 Content of silicon compounds contained in the sol (contents of silicon compounds having hydrolyzable functional groups or condensable functional groups (excluding polysiloxane compounds) contained in the sol because it becomes easier to obtain good reactivity. And the total content of hydrolysis products of the silicon compound having a hydrolyzable functional group) may be 5 parts by mass or more with respect to 100 parts by mass of the sol, or 10 parts by mass or more. It may be 12 mass parts or more, 15 mass parts or more, or 18 mass parts or more. Since it becomes easier to obtain good compatibility, the content of the silicon compound group may be 50 parts by mass or less, or 30 parts by mass or less, based on 100 parts by mass of the sol. It may be 25 parts by mass or less, or 20 parts by mass or less. That is, the content of the silicon compound group may be 5 to 50 parts by mass, 10 to 30 parts by mass, or 12 to 30 parts by mass with respect to 100 parts by mass of the sol. It may be 15 to 25 parts by mass, or 18 to 20 parts by mass.
　前記ポリシロキサン化合物群の含有量及び前記ケイ素化合物群の含有量の総和は、良好な反応性を更に得易くなる観点から、ゾルの総量１００質量部に対し、５質量部以上であってもよく、１０質量部以上であってもよく、１５質量部以上であってもよく、２０質量部以上であってもよく、２２質量部以上であってもよい。前記ポリシロキサン化合物群の含有量及び前記ケイ素化合物群の含有量の総和は、良好な相溶性を更に得易くなる観点から、ゾルの総量１００質量部に対し、５０質量部以下であってもよく、３０質量部以下であってもよく、２５質量部以下であってもよい。これらの観点から、前記ポリシロキサン化合物群の含有量及び前記ケイ素化合物群の含有量の総和は、ゾルの総量１００質量部に対し、５～５０質量部であってもよく、１０～３０質量部であってもよく、１５～３０質量部であってもよく、２０～３０質量部であってもよく、２２～２５質量部であってもよい。 The sum of the content of the polysiloxane compound group and the content of the silicon compound group may be 5 parts by mass or more with respect to 100 parts by mass of the sol from the viewpoint of further easily obtaining good reactivity. It may be 10 parts by mass or more, 15 parts by mass or more, 20 parts by mass or more, or 22 parts by mass or more. The sum of the content of the polysiloxane compound group and the content of the silicon compound group may be 50 parts by mass or less with respect to 100 parts by mass of the total amount of the sol, from the viewpoint of easily obtaining good compatibility. 30 parts by mass or less, or 25 parts by mass or less. From these viewpoints, the sum of the content of the polysiloxane compound group and the content of the silicon compound group may be 5 to 50 parts by mass with respect to 100 parts by mass of the sol, or 10 to 30 parts by mass. It may be 15 to 30 parts by mass, 20 to 30 parts by mass, or 22 to 25 parts by mass.
　前記ポリシロキサン化合物群の含有量と、前記ケイ素化合物群の含有量との比（ポリシロキサン化合物群：ケイ素化合物群）は、良好な相溶性を更に得易くなる観点から、１：０．５以上であってもよく、１：１以上であってもよく、１：２以上であってもよく、１：３以上であってもよい。前記ポリシロキサン化合物群の含有量と、前記ケイ素化合物群の含有量との比（ポリシロキサン化合物群：ケイ素化合物群）は、ゲルの収縮を更に抑制し易くなる観点から、１：５以下であってもよく、１：４以下であってもよく、１：２以下であってもよい。これらの観点から、前記ポリシロキサン化合物群の含有量と、前記ケイ素化合物群の含有量との比（ポリシロキサン化合物群：ケイ素化合物群）は、１：０．５～１：５であってもよく、１：０．５～１：４であってもよく、１：１～１：２であってもよく、１：２～１：４であってもよく、１：３～１：４であってもよい。 The ratio of the content of the polysiloxane compound group and the content of the silicon compound group (polysiloxane compound group: silicon compound group) is 1: 0.5 or more from the viewpoint of further easily obtaining good compatibility. Or 1: 1 or more, 1: 2 or more, or 1: 3 or more. The ratio of the content of the polysiloxane compound group to the content of the silicon compound group (polysiloxane compound group: silicon compound group) is 1: 5 or less from the viewpoint of further easily suppressing gel shrinkage. It may be 1: 4 or less, or 1: 2 or less. From these viewpoints, the ratio of the content of the polysiloxane compound group to the content of the silicon compound group (polysiloxane compound group: silicon compound group) may be 1: 0.5 to 1: 5. It may be 1: 0.5 to 1: 4, may be 1: 1 to 1: 2, may be 1: 2 to 1: 4, and may be 1: 3 to 1: 4. It may be.
［第三の態様］
　本実施形態に係るエアロゲルは、下記一般式（１）で表される構造を有することができる。本実施形態に係るエアロゲルは、式（１）で表される構造を含む構造として、下記一般式（１ａ）で表される構造を有することができる。上記一般式（Ａ）で表される構造を有するポリシロキサン化合物を使用することにより、式（１）及び式（１ａ）で表される構造をエアロゲルの骨格中に導入することができる。 [Third embodiment]
The airgel according to the present embodiment can have a structure represented by the following general formula (1). The airgel which concerns on this embodiment can have a structure represented by the following general formula (1a) as a structure containing the structure represented by Formula (1). By using the polysiloxane compound having the structure represented by the general formula (A), the structures represented by the formulas (1) and (1a) can be introduced into the skeleton of the airgel.
Figure JPOXMLDOC01-appb-C000004
Figure JPOXMLDOC01-appb-C000004
Figure JPOXMLDOC01-appb-C000005
Figure JPOXMLDOC01-appb-C000005
　式（１）及び式（１ａ）中、Ｒ１及びＲ２はそれぞれ独立にアルキル基又はアリール基を示し、Ｒ３及びＲ４はそれぞれ独立にアルキレン基を示す。ここで、アリール基としては、例えばフェニル基及び置換フェニル基が挙げられる。置換フェニル基の置換基としては、例えばアルキル基、ビニル基、メルカプト基、アミノ基、ニトロ基及びシアノ基が挙げられる。ｐは１～５０の整数を示す。式（１ａ）中、２個以上のＲ１は各々同一であっても異なっていてもよく、同様に、２個以上のＲ２は各々同一であっても異なっていてもよい。式（１ａ）中、２個のＲ３は各々同一であっても異なっていてもよく、同様に、２個のＲ４は各々同一であっても異なっていてもよい。 In formula (1) and formula (1a), R 1 and R 2 each independently represent an alkyl group or an aryl group, and R 3 and R 4 each independently represent an alkylene group. Here, examples of the aryl group include a phenyl group and a substituted phenyl group. Examples of the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, and a cyano group. p represents an integer of 1 to 50. In formula (1a), two or more R 1 s may be the same or different, and similarly, two or more R 2 s may be the same or different. In formula (1a), two R 3 s may be the same or different, and similarly, two R 4 s may be the same or different.
　上記式（１）又は式（１ａ）で表される構造をエアロゲルの骨格中に導入することにより、撥水性に優れると共に、低熱伝導率かつ柔軟なエアロゲルを容易に得ることができる。同様の観点から、以下に示す特徴を満たしてもよい。式（１）及び式（１ａ）中、Ｒ１及びＲ２は、それぞれ独立に炭素数が１～６のアルキル基又はフェニル基であってもよい。当該アルキル基は、メチル基であってもよい。式（１）及び式（１ａ）中、Ｒ３及びＲ４は、それぞれ独立に炭素数が１～６のアルキレン基であってもよい。当該アルキレン基は、エチレン基又はプロピレン基であってもよい。式（１ａ）中、ｐは２～３０とすることができ、５～２０であってもよい。 By introducing the structure represented by the above formula (1) or formula (1a) into the skeleton of the airgel, it is possible to easily obtain a flexible airgel having excellent water repellency and low thermal conductivity. From the same viewpoint, the following features may be satisfied. In formula (1) and formula (1a), R 1 and R 2 may each independently be an alkyl group having 1 to 6 carbon atoms or a phenyl group. The alkyl group may be a methyl group. In formula (1) and formula (1a), R 3 and R 4 may each independently be an alkylene group having 1 to 6 carbon atoms. The alkylene group may be an ethylene group or a propylene group. In the formula (1a), p can be 2 to 30, and can be 5 to 20.
［第四の態様］
　本実施形態に係るエアロゲルは、支柱部及び橋かけ部を備えるラダー型構造を有するエアロゲルであり、かつ、橋かけ部が、下記一般式（２）で表される構造を有するエアロゲルであってもよい。エアロゲルの骨格中にこのようなラダー型構造を導入することにより、耐熱性及び機械的強度を容易に向上させることができる。上記一般式（Ｂ）で表される構造を有するポリシロキサン化合物を使用することにより、一般式（２）で表される構造を有する橋かけ部を含むラダー型構造をエアロゲルの骨格中に導入することができる。なお、本実施形態において「ラダー型構造」とは、２本の支柱部（ｓｔｒｕｔｓ）と、支柱部同士を連結する橋かけ部（ｂｒｉｄｇｅｓ）とを有する構造（いわゆる「梯子」の形態を有する構造）である。本態様において、エアロゲル骨格がラダー型構造からなっていてもよいが、エアロゲルが部分的にラダー型構造を有していてもよい。 [Fourth aspect]
Even if the airgel which concerns on this embodiment is an airgel which has a ladder type structure provided with a support | pillar part and a bridge | bridging part, and a bridge | bridging part has a structure represented by following General formula (2), Good. By introducing such a ladder structure into the airgel skeleton, heat resistance and mechanical strength can be easily improved. By using the polysiloxane compound having the structure represented by the general formula (B), a ladder structure including a bridge portion having the structure represented by the general formula (2) is introduced into the skeleton of the airgel. be able to. In the present embodiment, the “ladder structure” is a structure having two struts and bridges connecting the struts (a structure having a so-called “ladder” form). ). In this embodiment, the airgel skeleton may have a ladder structure, but the airgel may partially have a ladder structure.
Figure JPOXMLDOC01-appb-C000006
Figure JPOXMLDOC01-appb-C000006
　式（２）中、Ｒ５及びＲ６はそれぞれ独立にアルキル基又はアリール基を示し、ｂは１～５０の整数を示す。ここで、アリール基としては、例えばフェニル基及び置換フェニル基が挙げられる。置換フェニル基の置換基としては、例えばアルキル基、ビニル基、メルカプト基、アミノ基、ニトロ基及びシアノ基が挙げられる。なお、式（２）中、ｂが２以上の整数の場合、２個以上のＲ５は各々同一であっても異なっていてもよく、同様に、２個以上のＲ６は各々同一であっても異なっていてもよい。 In formula (2), R 5 and R 6 each independently represents an alkyl group or an aryl group, and b represents an integer of 1 to 50. Here, examples of the aryl group include a phenyl group and a substituted phenyl group. Examples of the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, and a cyano group. In formula (2), when b is an integer of 2 or more, two or more R 5 s may be the same or different, and similarly, two or more R 6 s are the same. Or different.
　上記の構造をエアロゲルの骨格中に導入することにより、例えば、従来のラダー型シルセスキオキサンに由来する構造を有する（すなわち、下記一般式（Ｘ）で表される構造を有する）エアロゲルよりも優れた柔軟性を有するエアロゲルとなる。なお、下記一般式（Ｘ）に示すように、従来のラダー型シルセスキオキサンに由来する構造を有するエアロゲルでは、橋かけ部の構造が－Ｏ－であるが、本態様のエアロゲルでは、橋かけ部の構造が上記一般式（２）で表される構造（ポリシロキサン構造）である。 By introducing the above structure into the skeleton of the airgel, for example, the airgel has a structure derived from a conventional ladder-type silsesquioxane (that is, has a structure represented by the following general formula (X)). It becomes the airgel which has the outstanding softness | flexibility. As shown in the following general formula (X), in the airgel having a structure derived from a conventional ladder-type silsesquioxane, the structure of the bridge portion is —O—. The structure of the hanging portion is a structure (polysiloxane structure) represented by the general formula (2).
Figure JPOXMLDOC01-appb-C000007
Figure JPOXMLDOC01-appb-C000007
　式（Ｘ）中、Ｒはヒドロキシ基、アルキル基又はアリール基を示す。 In the formula (X), R represents a hydroxy group, an alkyl group or an aryl group.
　支柱部となる構造及びその鎖長、並びに、橋かけ部となる構造の間隔は、特に限定されないが、耐熱性と機械的強度とを更に向上させる観点から、ラダー型構造としては、下記一般式（３）で表されるラダー型構造を有していてもよい。 The structure of the column part and its chain length, and the interval of the structure of the bridge part are not particularly limited, but from the viewpoint of further improving the heat resistance and mechanical strength, the ladder structure has the following general formula: You may have the ladder type structure represented by (3).
Figure JPOXMLDOC01-appb-C000008
Figure JPOXMLDOC01-appb-C000008
　式（３）中、Ｒ５、Ｒ６、Ｒ７及びＲ８はそれぞれ独立にアルキル基又はアリール基を示し、ａ及びｃはそれぞれ独立に１～３０００の整数を示し、ｂは１～５０の整数を示す。ここで、アリール基としては、例えばフェニル基及び置換フェニル基が挙げられる。置換フェニル基の置換基としては、例えばアルキル基、ビニル基、メルカプト基、アミノ基、ニトロ基及びシアノ基が挙げられる。式（３）中、ｂが２以上の整数の場合、２個以上のＲ５は各々同一であっても異なっていてもよく、同様に、２個以上のＲ６は各々同一であっても異なっていてもよい。式（３）中、ａが２以上の整数の場合、２個以上のＲ７は各々同一であっても異なっていてもよい。式（３）中、ｃが２以上の整数の場合、２個以上のＲ８は各々同一であっても異なっていてもよい。 In the formula (3), R 5 , R 6 , R 7 and R 8 each independently represents an alkyl group or an aryl group, a and c each independently represents an integer of 1 to 3000, and b is 1 to 50 Indicates an integer. Here, examples of the aryl group include a phenyl group and a substituted phenyl group. Examples of the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, and a cyano group. In Formula (3), when b is an integer of 2 or more, two or more R 5 s may be the same or different, and similarly, two or more R 6 s may be the same. May be different. In formula (3), when a is an integer of 2 or more, two or more R 7 s may be the same or different. In formula (3), when c is an integer of 2 or more, two or more R 8 s may be the same or different.
　更に優れた撥水性と柔軟性とを得る観点から、式（２）及び式（３）中、Ｒ５、Ｒ６、Ｒ７及びＲ８（ただし、Ｒ７及びＲ８は式（３）中のみ）は、それぞれ独立に炭素数が１～６のアルキル基又はフェニル基であってもよい。当該アルキル基は、メチル基であってもよい。式（３）中、ａ及びｃは、それぞれ独立に６～２０００であってもよく、１０～１０００であってもよい。式（２）及び式（３）中、ｂは、２～３０であってもよく、５～２０であってもよい。 Further, from the viewpoint of obtaining excellent water repellency and flexibility, in formula (2) and formula (3), R 5 , R 6 , R 7 and R 8 (where R 7 and R 8 are in formula (3)). Only) may be independently an alkyl group having 1 to 6 carbon atoms or a phenyl group. The alkyl group may be a methyl group. In formula (3), a and c may each independently be 6 to 2000, or 10 to 1000. In the formulas (2) and (3), b may be 2 to 30, or 5 to 20.
［第五の態様］
　本実施形態に係るエアロゲルは、エアロゲル層を更に強靱化する観点並びに更に優れた断熱性及び柔軟性を達成する観点から、シリカ粒子を含有していてもよい。エアロゲルを与えるゾルは、シリカ粒子を更に含有していてもよい。すなわち、本実施形態に係るエアロゲルは、シリカ粒子を含有するゾルの縮合物である湿潤ゲルの乾燥物（前記ゾルから生成された湿潤ゲルを乾燥して得られるもの）であってもよい。エアロゲル層は、シリカ粒子を含有するゾルの縮合物である湿潤ゲルの乾燥物から構成される層であってもよい。例えば、エアロゲル層は、シリカ粒子を含有するゾルから生成された湿潤ゲルを乾燥してなる層で構成されていてもよい。すなわち、エアロゲル層は、シリカ粒子を含有するゾルから形成されるものであってもよい。なお、これまで述べてきたエアロゲルも、このように、シリカ粒子を含有するゾルの縮合物である湿潤ゲルの乾燥物（前記ゾルから生成された湿潤ゲルを乾燥することで得られるもの）であってもよい。 [Fifth aspect]
The airgel according to the present embodiment may contain silica particles from the viewpoint of further toughening the airgel layer and further achieving excellent heat insulation and flexibility. The sol that gives the airgel may further contain silica particles. That is, the airgel according to the present embodiment may be a dried product of a wet gel that is a condensate of a sol containing silica particles (obtained by drying a wet gel generated from the sol). The airgel layer may be a layer composed of a dried product of a wet gel that is a condensate of a sol containing silica particles. For example, the airgel layer may be composed of a layer obtained by drying a wet gel generated from a sol containing silica particles. That is, the airgel layer may be formed from a sol containing silica particles. In addition, the airgel described so far is also a dried product of a wet gel that is a condensate of a sol containing silica particles (obtained by drying a wet gel generated from the sol). May be.
　シリカ粒子としては、特に制限なく用いることができ、例えば、非晶質シリカ粒子が挙げられる。非晶質シリカ粒子としては、例えば、溶融シリカ粒子、ヒュームドシリカ粒子及びコロイダルシリカ粒子が挙げられる。これらのうち、コロイダルシリカ粒子は、単分散性が高く、ゾル中での凝集を抑制し易い。 The silica particles can be used without particular limitation, and examples thereof include amorphous silica particles. Examples of the amorphous silica particles include fused silica particles, fumed silica particles, and colloidal silica particles. Among these, colloidal silica particles have high monodispersity and are easy to suppress aggregation in the sol.
　シリカ粒子の形状としては、特に制限されず、球状、繭型、会合型等が挙げられる。これらのうち、シリカ粒子として球状の粒子を用いることにより、ゾル中での凝集を抑制し易くなる。シリカ粒子の平均一次粒子径は、適度な強度及び柔軟性をエアロゲルに付与し易くなり、乾燥時の耐収縮性に優れるエアロゲルが得易くなる観点から、１ｎｍ以上であってもよく、５ｎｍ以上であってもよく、１０ｎｍ以上であってもよく、２０ｎｍ以上であってもよい。シリカ粒子の平均一次粒子径は、シリカ粒子の固体熱伝導を抑制し易くなり、断熱性に優れるエアロゲルが得易くなる観点から、５００ｎｍ以下であってもよく、３００ｎｍ以下であってもよく、２５０ｎｍ以下であってもよく、１００ｎｍ以下であってもよい。これらの観点から、シリカ粒子の平均一次粒子径は、１～５００ｎｍであってもよく、５～３００ｎｍであってもよく、１０～２５０ｎｍであってもよく、２０～１００ｎｍであってもよい。 The shape of the silica particles is not particularly limited, and examples thereof include a spherical shape, a cage shape, and an association type. Among these, by using spherical particles as silica particles, it becomes easy to suppress aggregation in the sol. The average primary particle diameter of the silica particles may be 1 nm or more, or 5 nm or more, from the viewpoint that it is easy to impart an appropriate strength and flexibility to the airgel, and an airgel excellent in shrinkage resistance during drying is easily obtained. It may be 10 nm or more, or 20 nm or more. The average primary particle diameter of the silica particles may be 500 nm or less, may be 300 nm or less, may be 300 nm or less, and may be 250 nm from the viewpoint that it is easy to suppress the solid heat conduction of the silica particles and easily obtain an airgel excellent in heat insulation. Or 100 nm or less. From these viewpoints, the average primary particle diameter of the silica particles may be 1 to 500 nm, 5 to 300 nm, 10 to 250 nm, or 20 to 100 nm.
　本実施形態において、粒子の平均粒子径（シリカ粒子の平均一次粒子径等）は、走査型電子顕微鏡（以下「ＳＥＭ」と略記する。）を用いてエアロゲル層の断面を直接観察することにより得ることができる。例えば、エアロゲルの内部における網目状の微細構造からは、エアロゲル層の断面に露出した粒子の直径に基づきエアロゲル粒子又はシリカ粒子個々の粒子径を得ることができる。ここでいう「直径」とは、エアロゲル層の断面に露出した粒子の断面を円とみなした場合の直径を意味する。また、「断面を円とみなした場合の直径」とは、断面の面積を同じ面積の真円に置き換えたときの当該真円の直径のことである。なお、平均粒子径の算出に当たっては、１００個の粒子について円の直径を求め、その平均を取るものとする。 In the present embodiment, the average particle size of the particles (average primary particle size of silica particles, etc.) is obtained by directly observing the cross section of the airgel layer using a scanning electron microscope (hereinafter abbreviated as “SEM”). be able to. For example, the particle size of each airgel particle or silica particle can be obtained from the mesh-like microstructure inside the airgel based on the diameter of the particles exposed in the cross section of the airgel layer. The “diameter” here means a diameter when the cross section of the particle exposed in the cross section of the airgel layer is regarded as a circle. The “diameter when the cross section is regarded as a circle” is the diameter of the true circle when the area of the cross section is replaced with a true circle having the same area. In calculating the average particle diameter, the diameter of a circle is obtained for 100 particles, and the average is taken.
　なお、シリカ粒子の平均粒子径は、原料から測定することができる。例えば、二軸平均一次粒子径は、任意の粒子２０個をＳＥＭにより観察した結果から、次のようにして算出される。すなわち、通常水に分散している固形分濃度５～４０質量％のコロイダルシリカ粒子を例にすると、コロイダルシリカ粒子の分散液に、パターン配線付きウエハを２ｃｍ角に切って得られたチップを約３０秒浸した後、当該チップを純水にて約３０秒間すすぎ、窒素ブロー乾燥する。その後、チップをＳＥＭ観察用の試料台に載せ、加速電圧１０ｋＶを掛け、１０万倍の倍率にてシリカ粒子を観察し、画像を撮影する。得られた画像から２０個のシリカ粒子を任意に選択し、それらの粒子の粒子径の平均を平均粒子径とする。この際、選択したシリカ粒子が図３に示すような形状であった場合、シリカ粒子Ｐに外接し、その長辺が最も長くなるように配置した長方形（外接長方形Ｌ）を導く。そして、その外接長方形Ｌの長辺をＸ、短辺をＹとして、（Ｘ＋Ｙ）／２として二軸平均一次粒子径を算出し、その粒子の粒子径とする。 In addition, the average particle diameter of the silica particles can be measured from the raw material. For example, the biaxial average primary particle diameter is calculated as follows from the result of observing 20 arbitrary particles by SEM. That is, when colloidal silica particles having a solid content concentration of 5 to 40% by mass, which are usually dispersed in water, are taken as an example, a chip obtained by cutting a wafer with a patterned wiring into 2 cm squares is dispersed in a colloidal silica particle dispersion. After soaking for 30 seconds, the chip is rinsed with pure water for about 30 seconds and blown with nitrogen. Thereafter, the chip is placed on a sample stage for SEM observation, an acceleration voltage of 10 kV is applied, the silica particles are observed at a magnification of 100,000, and an image is taken. 20 silica particles are arbitrarily selected from the obtained image, and the average of the particle diameters of these particles is defined as the average particle diameter. At this time, when the selected silica particles have a shape as shown in FIG. 3, a rectangle (circumscribed rectangle L) circumscribing the silica particles P and arranged so that the long side is the longest is led. And the long side of the circumscribed rectangle L is X, the short side is Y, and the biaxial average primary particle diameter is calculated as (X + Y) / 2, and is defined as the particle diameter of the particle.
　シリカ粒子の１ｇ当たりのシラノール基数は、耐収縮性に優れるエアロゲルを得易くなる観点から、１０×１０１８個／ｇ以上であってもよく、５０×１０１８個／ｇ以上であってもよく、１００×１０１８個／ｇ以上であってもよい。シリカ粒子の１ｇ当たりのシラノール基数は、均質なエアロゲルが得易くなる観点から、１０００×１０１８個／ｇ以下であってもよく、８００×１０１８個／ｇ以下であってもよく、７００×１０１８個／ｇ以下であってもよい。これらの観点から、シリカ粒子の１ｇ当たりのシラノール基数は、１０×１０１８～１０００×１０１８個／ｇであってもよく、５０×１０１８～８００×１０１８個／ｇであってもよく、１００×１０１８～７００×１０１８個／ｇであってもよい。 The number of silanol groups per gram of silica particles may be 10 × 10 18 pieces / g or more, or 50 × 10 18 pieces / g or more from the viewpoint of easily obtaining an airgel having excellent shrinkage resistance. 100 × 10 18 pieces / g or more. The number of silanol groups per gram of silica particles may be 1000 × 10 18 pieces / g or less, may be 800 × 10 18 pieces / g or less, and 700 × 10 18 / g may be less than or equal to. From these viewpoints, the number of silanol groups per gram of silica particles may be 10 × 10 18 to 1000 × 10 18 pcs / g, or may be 50 × 10 18 to 800 × 10 18 pcs / g. 100 × 10 18 to 700 × 10 18 pieces / g.
　上記ゾルに含まれるシリカ粒子の含有量は、適度な強度をエアロゲルに付与し易くなり、乾燥時の耐収縮性に優れるエアロゲルが得易くなる観点から、ゾルの総量１００質量部に対し、１質量部以上であってもよく、４質量部以上であってもよい。上記ゾルに含まれるシリカ粒子の含有量は、シリカ粒子の固体熱伝導を抑制し易くなり、断熱性に優れるエアロゲルが得易くなる観点から、ゾルの総量１００質量部に対し、２０質量部以下であってもよく、１５質量部以下であってもよく、１２質量部以下であってもよく、１０質量部以下であってもよく、８質量部以下であってもよい。これらの観点から、上記ゾルに含まれるシリカ粒子の含有量は、ゾルの総量１００質量部に対し、１～２０質量部であってもよく、４～１５質量部であってもよく、４～１２質量部であってもよく、４～１０質量部であってもよく、４～８質量部であってもよい。 The content of the silica particles contained in the sol is 1 mass with respect to 100 mass parts of the total amount of the sol from the viewpoint of easily imparting an appropriate strength to the airgel and easily obtaining an airgel excellent in shrinkage resistance during drying. Or 4 parts by mass or more. The content of the silica particles contained in the sol is 20 parts by mass or less with respect to 100 parts by mass of the total amount of the sol, from the viewpoint of easily suppressing the solid heat conduction of the silica particles and easily obtaining an airgel excellent in heat insulation. It may be 15 parts by mass or less, 12 parts by mass or less, 10 parts by mass or less, or 8 parts by mass or less. From these viewpoints, the content of the silica particles contained in the sol may be 1 to 20 parts by mass, 4 to 15 parts by mass, or 4 to 4 parts by mass with respect to 100 parts by mass of the total amount of the sol. It may be 12 parts by mass, 4 to 10 parts by mass, or 4 to 8 parts by mass.
［その他の態様］
　本実施形態に係るエアロゲルは、下記一般式（４）で表される構造を有することができる。本実施形態に係るエアロゲルは、シリカ粒子を含有すると共に、下記一般式（４）で表される構造を有することができる。 [Other aspects]
The airgel according to the present embodiment can have a structure represented by the following general formula (4). The airgel which concerns on this embodiment can have a structure represented by following General formula (4) while containing a silica particle.
Figure JPOXMLDOC01-appb-C000009
Figure JPOXMLDOC01-appb-C000009
　式（４）中、Ｒ９はアルキル基を示す。アルキル基としては、例えば、炭素数が１～６のアルキル基が挙げられ、具体的には、メチル基が挙げられる。 In formula (4), R 9 represents an alkyl group. Examples of the alkyl group include alkyl groups having 1 to 6 carbon atoms, and specific examples include a methyl group.
　本実施形態に係るエアロゲルは、下記一般式（５）で表される構造を有することができる。本実施形態に係るエアロゲルは、シリカ粒子を含有すると共に、下記一般式（５）で表される構造を有することができる。 The airgel according to the present embodiment can have a structure represented by the following general formula (5). The airgel which concerns on this embodiment can have a structure represented by following General formula (5) while containing a silica particle.
Figure JPOXMLDOC01-appb-C000010
Figure JPOXMLDOC01-appb-C000010
　式（５）中、Ｒ１０及びＲ１１はそれぞれ独立にアルキル基を示す。アルキル基としては、例えば、炭素数が１～６のアルキル基が挙げられ、具体的には、メチル基が挙げられる。 In formula (5), R 10 and R 11 each independently represent an alkyl group. Examples of the alkyl group include alkyl groups having 1 to 6 carbon atoms, and specific examples include a methyl group.
　本実施形態に係るエアロゲルは、下記一般式（６）で表される構造を有することができる。本実施形態に係るエアロゲルは、シリカ粒子を含有すると共に、下記一般式（６）で表される構造を有することができる。 The airgel according to the present embodiment can have a structure represented by the following general formula (6). The airgel which concerns on this embodiment can have a structure represented by following General formula (6) while containing a silica particle.
Figure JPOXMLDOC01-appb-C000011
Figure JPOXMLDOC01-appb-C000011
　式（６）中、Ｒ１２はアルキレン基を示す。アルキレン基としては、例えば、炭素数が１～１０のアルキレン基が挙げられ、具体的には、エチレン基及びヘキシレン基が挙げられる。 In the formula (6), R 12 represents an alkylene group. Examples of the alkylene group include an alkylene group having 1 to 10 carbon atoms, and specific examples include an ethylene group and a hexylene group.
　本実施形態に係るエアロゲルは、ポリシロキサン由来の構造を有していてもよい。ポリシロキサン由来の構造としては、例えば、上記一般式（１）、（２）、（３）、（４）、（５）又は（６）で表される構造が挙げられる。本実施形態に係るエアロゲルは、シリカ粒子を含有せずに、上記一般式（４）、（５）及び（６）で表される構造のうち、少なくとも一種を有するものであってもよい。 The airgel according to this embodiment may have a structure derived from polysiloxane. Examples of the structure derived from polysiloxane include structures represented by the above general formula (1), (2), (3), (4), (5), or (6). The airgel which concerns on this embodiment may have at least 1 type among the structures represented by the said General formula (4), (5) and (6), without containing a silica particle.
　エアロゲル層の厚みは、エアロゲル層の信頼性を確保し易くなることから、１μｍ以上であってもよく、２μｍ以上であってもよく、３μｍ以上であってもよく、１０μｍ以上であってもよく、３０μｍ以上であってもよい。エアロゲル層の厚みは、後述の洗浄及び溶媒置換工程を短縮できる観点から、５０００μｍ以下であってもよく、４０００μｍ以下であってもよく、３０００μｍ以下であってもよく、１０００μｍ以下であってもよく、５００μｍ以下であってもよく、２５０μｍ以下であってもよい。これらの観点から、エアロゲル層の厚みは、１～５０００μｍであってもよく、２～４０００μｍであってもよく、３～３０００μｍであってもよく、１０～１０００μｍであってもよく、１０～５００μｍであってもよく、３０～２５０μｍであってもよい。 The thickness of the airgel layer can be 1 μm or more, 2 μm or more, 3 μm or more, or 10 μm or more because it is easy to ensure the reliability of the airgel layer. 30 μm or more. The thickness of the airgel layer may be 5000 μm or less, 4000 μm or less, 3000 μm or less, or 1000 μm or less from the viewpoint of shortening the later-described washing and solvent replacement step. 500 μm or less, or 250 μm or less. From these viewpoints, the thickness of the airgel layer may be 1 to 5000 μm, 2 to 4000 μm, 3 to 3000 μm, 10 to 1000 μm, 10 to 500 μm. It may be 30 to 250 μm.
＜構造体の製造方法＞
　次に、構造体の製造方法について説明する。 <Method for manufacturing structure>
Next, a method for manufacturing the structure will be described.
　本実施形態に係る構造体の製造方法は、エアロゲル層が形成された構造体の製造方法であって、ミスト状のゾルからエアロゲル層を形成する工程（以下、「エアロゲル層形成工程」ともいう）を備える方法である。ミスト状のゾルは、例えば、上述したゾルをミストの形態にしたものであってよい。かかる製造方法によれば、エアロゲル層のムラが抑制された構造体を製造することができる。また、かかる製造方法によれば、本体部の形状に依存することなく、厚膜のエアロゲル層を形成できると共に、エアロゲル層の膜厚を容易に制御することができる。また、通常、エアロゲルを厚膜化すると、クラックが生じ易くなる傾向にあるが、かかる製造方法によれば、クラックが低減される。本実施形態に係る構造体の製造方法によれば、対象物の形状が複雑化した場合でも、エアロゲルに欠陥が生じ難いことから、エアロゲルとしての性能の信頼性を高く保つことができる。 The structure manufacturing method according to the present embodiment is a structure manufacturing method in which an airgel layer is formed, and a step of forming an airgel layer from a mist-like sol (hereinafter, also referred to as “airgel layer forming step”). It is a method provided with. The mist sol may be, for example, a mist form of the sol described above. According to this manufacturing method, a structure in which unevenness of the airgel layer is suppressed can be manufactured. Moreover, according to this manufacturing method, a thick airgel layer can be formed without depending on the shape of the main body, and the thickness of the airgel layer can be easily controlled. In general, when the airgel is thickened, cracks tend to easily occur. However, according to such a manufacturing method, cracks are reduced. According to the structure manufacturing method according to the present embodiment, even when the shape of the object is complicated, it is difficult for the airgel to be defective. Therefore, the reliability of the performance as the airgel can be kept high.
　また、本実施形態に係る構造体の製造方法によれば、ゲル内部の毛細管力に起因するストレスが生じ難いことから、ゲルの収縮が生じ難く、エアロゲルとしての信頼性を保ち易い傾向にある。 Further, according to the structure manufacturing method according to the present embodiment, stress due to the capillary force inside the gel is unlikely to occur, so that gel contraction is unlikely to occur and the reliability as an airgel tends to be maintained.
　エアロゲル層形成工程は、例えば、ミストの形態のゾルからゾル層を形成した後、上記ゾル層からエアロゲル層を形成する工程であってもよい。 The airgel layer forming step may be, for example, a step of forming the airgel layer from the sol layer after forming the sol layer from the mist in the form of mist.
　具体的には、例えば、図４に示すように、エアロゲル層を形成する対象である対象物１０を準備した後（図４（ａ））、当該対象物１０上に、ミストの形態のゾル（「ゾル塗液」ともいう）からゾル層５ａを形成した後（図４（ｂ））、ゾル層５ａからエアロゲル層５を形成する（図４（ｃ））。対象物が本体部のみである場合には、本体部を準備した後、本体部に直接ゾルを付与すればよい。 Specifically, for example, as shown in FIG. 4, after preparing an object 10 that is an object for forming an airgel layer (FIG. 4A), a sol in the form of mist ( After forming the sol layer 5a from the “sol coating solution” (FIG. 4B), the airgel layer 5 is formed from the sol layer 5a (FIG. 4C). If the object is only the main body, after preparing the main body, the sol may be applied directly to the main body.
　本実施形態に係る構造体の製造方法においては、前記構造体が、本体部と、前記本体部の表面の少なくとも一部を被覆する被覆層とを備え、前記被覆層が中間層となるように、少なくとも前記被覆層上にエアロゲル層が形成されてもよい。すなわち、エアロゲル層を形成する対象である対象物が、本体部と被覆層とを備える場合には、例えば、図５に示すように、本体部３と被覆層４とを備える対象物１０を準備した後（図５（ａ））、被覆層４が中間層となるように、被覆層４上に、ミストの形態のゾルからゾル層５ａを形成した後（図５（ｂ））、ゾル層５ａからエアロゲル層５を形成する（図５（ｃ））。これにより、エアロゲル層の密着性が更に向上すると共に、エアロゲル層の剥離及び脱落が更に抑制される。なお、本体部及び被覆層に関する態様は、上述したとおりである。 In the structure manufacturing method according to the present embodiment, the structure includes a main body portion and a covering layer that covers at least a part of the surface of the main body portion, and the covering layer serves as an intermediate layer. In addition, an airgel layer may be formed on at least the coating layer. That is, when the target object that forms the airgel layer includes the main body part and the covering layer, for example, as shown in FIG. 5, the target object 10 including the main body part 3 and the covering layer 4 is prepared. After forming the sol layer 5a from the mist in the form of mist (FIG. 5 (b)) on the coating layer 4 so that the coating layer 4 becomes an intermediate layer (FIG. 5 (a)), the sol layer The airgel layer 5 is formed from 5a (FIG.5 (c)). Thereby, the adhesiveness of the airgel layer is further improved, and peeling and dropping of the airgel layer are further suppressed. In addition, the aspect regarding a main-body part and a coating layer is as having mentioned above.
　図４及び図５には、ゾル層を形成した後に、エアロゲル層を形成する形態を示したが、エアロゲル層は、ゾルの付与と同時に形成されてもよい。 4 and 5 show a form in which the airgel layer is formed after the sol layer is formed, but the airgel layer may be formed simultaneously with the application of the sol.
　以下、本実施形態に係る構造体の製造方法の具体例について、更に詳細に説明する。ただし、構造体の製造方法は、以下の方法に限定されるものではない。 Hereinafter, specific examples of the structure manufacturing method according to the present embodiment will be described in more detail. However, the manufacturing method of the structure is not limited to the following method.
　本実施形態に係る構造体は、例えば、対象物を準備する準備工程と、エアロゲルを形成するためのゾルを作製するゾル生成工程と、ゾル生成工程で得られたゾルを、ミスト状の形態で対象物に接触させることで、対象物に一体的に接合されたエアロゲル層を形成することにより構造体を得る接触工程と、接触工程で得られた構造体を熟成させる熟成工程と、熟成した構造体を洗浄及び／又は溶媒置換する工程と、洗浄及び／又は溶媒置換した構造体を乾燥する乾燥工程と、を主に備える製造方法により製造することができる。接触工程では、ミスト状のゾルを対象物に接触させた後に、必要に応じて乾燥してもよい。ここで、ミスト状のゾルからエアロゲル層を形成する工程の具体例は、例えば、上記接触工程を含む。また、「ゾル」とは、ゲル化反応が生じる前の状態であって、本実施形態においては、例えば、ケイ素化合物（必要に応じて、更にシリカ粒子）が溶媒中に溶解若しくは分散している状態を意味する。 The structure according to the present embodiment includes, for example, a preparation step for preparing an object, a sol generation step for producing a sol for forming an airgel, and a sol obtained in the sol generation step in a mist form. A contact process for obtaining a structure by forming an airgel layer integrally bonded to the object by contacting the object, an aging process for aging the structure obtained in the contact process, and an aged structure It can be produced by a production method mainly comprising a step of washing and / or solvent replacement of the body and a drying step of drying the washed and / or solvent-substituted structure. In the contact step, the mist-like sol may be contacted with the object and then dried as necessary. Here, the specific example of the process of forming an airgel layer from mist-like sol includes the said contact process, for example. Further, the “sol” is a state before the gelation reaction occurs, and in the present embodiment, for example, a silicon compound (and if necessary, further silica particles) is dissolved or dispersed in a solvent. Means state.
　以下、各工程について説明する。 Hereinafter, each process will be described.
｛準備工程｝
　準備工程においては、例えば、本体部又は被覆層が形成された本体部を準備する。被覆層は、例えば、本体部上に被覆層を形成する被覆層形成工程により形成できる。 {Preparation process}
In the preparation step, for example, a main body part or a main body part on which a coating layer is formed is prepared. The coating layer can be formed by, for example, a coating layer forming step of forming a coating layer on the main body portion.
（被覆層形成工程）
　被覆層形成工程は、例えば、被覆層形成用組成物を、本体部となる基材に接触させ、本体部上に被覆層を形成する工程である。具体的には、例えば、被覆層形成用組成物を、基材に接触させ、必要に応じ、加熱及び乾燥することにより被覆層を基材の表面に形成する。被覆層形成用組成物は、プライマ液等の液状組成物であってもよく、粘着シート等のシート状組成物であってもよい。 (Coating layer forming process)
A coating layer formation process is a process of making the composition for coating layer formation contact the base material used as a main-body part, for example, and forming a coating layer on a main-body part. Specifically, for example, the composition for forming a coating layer is brought into contact with the substrate, and if necessary, the coating layer is formed on the surface of the substrate by heating and drying. The composition for forming a coating layer may be a liquid composition such as a primer solution or a sheet-like composition such as an adhesive sheet.
　接触方法は、被覆層形成用組成物の種類、被覆層の厚み、又は基材の形状によって適宜選ばれる。例えば、被覆層形成用組成物がシート状組成物である場合には、基材に積層する方法等が利用でき、被覆層形成用組成物が液状組成物である場合には、例えば、ディップコート、スプレーコート、スピンコート、ロールコート等が利用できる。 The contact method is appropriately selected depending on the type of the coating layer forming composition, the thickness of the coating layer, or the shape of the substrate. For example, when the composition for forming a coating layer is a sheet-like composition, a method of laminating on a substrate can be used, and when the composition for forming a coating layer is a liquid composition, for example, dip coating Spray coating, spin coating, roll coating, etc. can be used.
　接触方法は、成膜性又は製造コストの観点から選ばれる。例えば、シート状又は繊維状の基材であれば、ディップコート又はロールコートを用いることができる。ブロック状、球状の基材であれば、ディップコート又はスプレーコートを用いることができる。 The contact method is selected from the viewpoint of film formability or manufacturing cost. For example, if it is a sheet-like or fibrous base material, dip coating or roll coating can be used. If it is a block-like or spherical base material, dip coating or spray coating can be used.
　被覆層形成工程では、被覆層形成用組成物を乾燥及び定着させる観点から、加熱処理を施してもよく、不純物を除去する観点及び被覆層の密着性を向上させる観点から、洗浄及び／又は乾燥を行ってもよい。また、被覆層の表面粗さを調整する目的で、被覆層表面に研磨処理及び／又は粗化処理を施してもよい。 In the coating layer forming step, heat treatment may be performed from the viewpoint of drying and fixing the composition for forming the coating layer, and washing and / or drying from the viewpoint of removing impurities and improving the adhesion of the coating layer. May be performed. Further, for the purpose of adjusting the surface roughness of the coating layer, the surface of the coating layer may be subjected to polishing treatment and / or roughening treatment.
｛ゾル生成工程｝
　ゾル生成工程は、例えば、ケイ素化合物（必要に応じて、更にシリカ粒子）と、溶媒とを混合して加水分解反応を行った後、ゾルゲル反応を行い、半ゲル化のゾル塗液を得る工程である。ゾル生成工程においては、加水分解反応を促進させるため、溶媒中に酸触媒を更に添加してもよい。また、特許第５２５０９００号公報に示されるように、溶媒中に界面活性剤、熱加水分解性化合物等を添加することもできる。さらに、ゲル化反応を促進させるため、塩基触媒を添加してもよい。なお、ゾル生成工程、接触工程、及び、熟成工程における工程時間を短縮し、加熱温度及び乾燥温度を低温化する観点から、ゾル中にシリカ粒子を含有してもよい。 {Sol generation process}
In the sol production step, for example, a silicon compound (if necessary, further silica particles) and a solvent are mixed and a hydrolysis reaction is performed, and then a sol-gel reaction is performed to obtain a semi-gelled sol coating liquid. It is. In the sol production step, an acid catalyst may be further added to the solvent in order to promote the hydrolysis reaction. Further, as disclosed in Japanese Patent No. 5250900, a surfactant, a thermohydrolyzable compound, or the like can be added to the solvent. Furthermore, a base catalyst may be added to promote the gelation reaction. In addition, you may contain a silica particle in a sol from a viewpoint of shortening the process time in a sol production | generation process, a contact process, and an aging process, and reducing a heating temperature and a drying temperature.
　溶媒の沸点は、接触工程において良好な塗工性を得る観点から、２００℃未満であってもよく、１７０℃以下であってもよく、１５０℃以下であってもよい。すなわち、上記ゾルは、沸点２００℃未満の溶媒を含有していてもよく、沸点１７０℃以下の溶媒を含有していてもよく、沸点１５０℃以下の溶媒を含有していてもよい。このような溶媒を含有するゾルによれば、厚膜のエアロゲル層をより容易に形成できるうえ、エアロゲル層のクラックが更に抑制される。この理由は、溶媒がこのようなものであると、ミスト状のゾルが本体部又は被覆層に接触した後、ゾルから短時間で容易に溶媒が蒸発して湿潤ゲルになり易く、湿潤ゲルの膜厚が増大し易いためであると推察する。 The boiling point of the solvent may be less than 200 ° C., 170 ° C. or less, or 150 ° C. or less from the viewpoint of obtaining good coatability in the contact step. That is, the sol may contain a solvent having a boiling point of less than 200 ° C., may contain a solvent having a boiling point of 170 ° C. or less, and may contain a solvent having a boiling point of 150 ° C. or less. According to the sol containing such a solvent, a thick airgel layer can be formed more easily, and cracks in the airgel layer are further suppressed. The reason for this is that if the solvent is such, after the mist-like sol comes into contact with the main body or the coating layer, the solvent easily evaporates from the sol in a short time and becomes a wet gel. This is presumably because the film thickness tends to increase.
　溶媒は、塗膜形成性を良好にする観点及び膜厚制御がし易い観点から、表面張力が高いものであってもよい。溶媒は、ゾルの粘度及び樹脂分の変化を抑制し、保存安定性を良好にする観点から、揮発性が低いものであってもよい。これらの特性を満たす溶媒としては、例えば、水、又は、水及びアルコールの混合液が挙げられる。アルコールとしては、例えば、メタノール、エタノール、ｎ－プロパノール、２－プロパノール、ｎ－ブタノール、２－ブタノール及びｔ－ブタノールが挙げられる。これらの中でも、表面張力が高く、揮発性が低い点から、水を用いてもよい。 The solvent may have a high surface tension from the viewpoint of improving the coating film formability and easy control of the film thickness. The solvent may have a low volatility from the viewpoint of suppressing changes in the sol viscosity and resin content and improving storage stability. Examples of the solvent that satisfies these characteristics include water or a mixed solution of water and alcohol. Examples of the alcohol include methanol, ethanol, n-propanol, 2-propanol, n-butanol, 2-butanol and t-butanol. Among these, water may be used because it has a high surface tension and low volatility.
　酸触媒としては、例えば、フッ酸、塩酸、硝酸、硫酸、亜硫酸、リン酸、亜リン酸、次亜リン酸、臭素酸、塩素酸、亜塩素酸、次亜塩素酸等の無機酸；酸性リン酸アルミニウム、酸性リン酸マグネシウム、酸性リン酸亜鉛等の酸性リン酸塩；ギ酸、酢酸、プロピオン酸、シュウ酸、マロン酸、コハク酸、クエン酸、リンゴ酸、アジピン酸、アゼライン酸等の有機カルボン酸が挙げられる。これらの中でも、酸触媒としては、得られる構造体の耐水性が更に向上する観点から、有機カルボン酸を用いることができ、具体的には、酢酸、ギ酸、プロピオン酸、シュウ酸及びマロン酸が挙げられ、酢酸であってもよい。酸触媒は、単独で又は２種類以上を混合して用いてもよい。 Examples of the acid catalyst include hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid, hypophosphorous acid, bromic acid, chloric acid, chlorous acid, hypochlorous acid, and other inorganic acids; Acid phosphates such as aluminum phosphate, acid magnesium phosphate, acid zinc phosphate; organics such as formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, citric acid, malic acid, adipic acid, azelaic acid Carboxylic acid is mentioned. Among these, as the acid catalyst, an organic carboxylic acid can be used from the viewpoint of further improving the water resistance of the resulting structure. Specifically, acetic acid, formic acid, propionic acid, oxalic acid and malonic acid are used. May be acetic acid. You may use an acid catalyst individually or in mixture of 2 or more types.
　酸触媒を用いることで、ケイ素化合物の加水分解反応を促進させて、より短時間でゾルを得ることができる。 By using an acid catalyst, the hydrolysis reaction of the silicon compound is promoted, and a sol can be obtained in a shorter time.
　酸触媒の添加量は、ケイ素化合物の総量１００質量部に対し、０．００１～０．１質量部であってもよい。 The addition amount of the acid catalyst may be 0.001 to 0.1 parts by mass with respect to 100 parts by mass of the total amount of the silicon compound.
　界面活性剤としては、非イオン性界面活性剤、イオン性界面活性剤等を用いることができる。界面活性剤は、単独で又は２種類以上を混合して用いてもよい。 As the surfactant, a nonionic surfactant, an ionic surfactant, or the like can be used. You may use surfactant individually or in mixture of 2 or more types.
　非イオン性界面活性剤としては、例えば、ポリオキシエチレン等の親水部と、主にアルキル基からなる疎水部とを含むもの、ポリオキシプロピレン等の親水部を含むものなどを使用できる。ポリオキシエチレン等の親水部と、主にアルキル基からなる疎水部とを含むものとしては、ポリオキシエチレンノニルフェニルエーテル、ポリオキシエチレンオクチルフェニルエーテル、ポリオキシエチレンアルキルエーテル等が挙げられる。ポリオキシプロピレン等の親水部を含むものとしては、ポリオキシプロピレンアルキルエーテル、ポリオキシエチレンとポリオキシプロピレンとのブロック共重合体等が挙げられる。 As the nonionic surfactant, for example, those containing a hydrophilic part such as polyoxyethylene and a hydrophobic part mainly composed of an alkyl group, and those containing a hydrophilic part such as polyoxypropylene can be used. Examples of those containing a hydrophilic part such as polyoxyethylene and a hydrophobic part mainly composed of an alkyl group include polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, and polyoxyethylene alkyl ether. Examples of those containing a hydrophilic portion such as polyoxypropylene include polyoxypropylene alkyl ethers, block copolymers of polyoxyethylene and polyoxypropylene, and the like.
　イオン性界面活性剤としては、カチオン性界面活性剤、アニオン性界面活性剤、両イオン性界面活性剤等を用いることができ、カチオン性界面活性剤又はアニオン性界面活性剤を用いてもよい。カチオン性界面活性剤としては、例えば、臭化セチルトリメチルアンモニウム（ＣＴＡＢ）及び塩化セチルトリメチルアンモニウムが挙げられる。アニオン性界面活性剤としては、例えば、ドデシルスルホン酸ナトリウムが挙げられる。両イオン性界面活性剤としては、例えば、アミノ酸系界面活性剤、ベタイン系界面活性剤及びアミンオキシド系界面活性剤が挙げられる。アミノ酸系界面活性剤としては、例えば、アシルグルタミン酸が挙げられる。ベタイン系界面活性剤としては、例えば、ラウリルジメチルアミノ酢酸ベタイン及びステアリルジメチルアミノ酢酸ベタインが挙げられる。アミンオキシド系界面活性剤としては、例えば、ラウリルジメチルアミンオキシドが挙げられる。 As the ionic surfactant, a cationic surfactant, an anionic surfactant, an amphoteric surfactant or the like can be used, and a cationic surfactant or an anionic surfactant may be used. Examples of the cationic surfactant include cetyltrimethylammonium bromide (CTAB) and cetyltrimethylammonium chloride. Examples of the anionic surfactant include sodium dodecyl sulfonate. Examples of amphoteric surfactants include amino acid surfactants, betaine surfactants, and amine oxide surfactants. Examples of amino acid surfactants include acyl glutamic acid. Examples of betaine surfactants include lauryldimethylaminoacetic acid betaine and stearyldimethylaminoacetic acid betaine. Examples of the amine oxide surfactant include lauryl dimethylamine oxide.
　これらの界面活性剤は、接触工程において、反応系中の溶媒と、成長していくシロキサン重合体との間の化学的親和性の差異を小さくし、相分離を抑制する作用を有すると考えられる。 These surfactants are thought to have the effect of reducing phase separation by reducing the difference in chemical affinity between the solvent in the reaction system and the growing siloxane polymer in the contacting step. .
　界面活性剤の添加量は、界面活性剤の種類、又は、ケイ素化合物の種類並びに量にも左右されるが、例えば、ケイ素化合物の総量１００質量部に対し、１～１００質量部であってもよく、５～６０質量部であってもよい。 The addition amount of the surfactant depends on the type of the surfactant or the type and amount of the silicon compound. For example, the amount of the surfactant may be 1 to 100 parts by mass with respect to 100 parts by mass of the total amount of the silicon compound. It may be 5 to 60 parts by mass.
　熱加水分解性化合物は、熱加水分解により塩基触媒を発生して、反応溶液を塩基性とし、ゾルゲル反応を促進すると考えられる。熱加水分解性化合物としては、加水分解後に反応溶液を塩基性にできる化合物であれば、特に限定されず、例えば、尿素；ホルムアミド、Ｎ－メチルホルムアミド、Ｎ，Ｎ－ジメチルホルムアミド、アセトアミド、Ｎ－メチルアセトアミド、Ｎ，Ｎ－ジメチルアセトアミド等の酸アミド；ヘキサメチレンテトラミン等の環状窒素化合物を挙げることができる。これらの中でも、特に尿素は上記促進効果が得られ易い。 It is considered that the thermohydrolyzable compound generates a base catalyst by thermal hydrolysis to make the reaction solution basic and promote the sol-gel reaction. The thermohydrolyzable compound is not particularly limited as long as it can make the reaction solution basic after hydrolysis. For example, urea; formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N- Examples include acid amides such as methylacetamide and N, N-dimethylacetamide; and cyclic nitrogen compounds such as hexamethylenetetramine. Among these, urea is particularly easy to obtain the above-mentioned promoting effect.
　熱加水分解性化合物の添加量は、ゾルゲル反応を充分に促進することができる量であれば、特に限定されない。例えば、熱加水分解性化合物（尿素等）の添加量は、ケイ素化合物の総量１００質量部に対して、１～２００質量部であってもよく、２～１５０質量部であってもよい。熱加水分解性化合物（尿素等）の添加量が１質量部以上であることにより、良好な反応性を更に得易くなり、また、２００質量部以下であることにより、結晶の析出及びゲル密度の低下を抑制し易くなる。 The amount of the thermally hydrolyzable compound added is not particularly limited as long as it is an amount that can sufficiently promote the sol-gel reaction. For example, the amount of the thermally hydrolyzable compound (urea or the like) added may be 1 to 200 parts by mass or 2 to 150 parts by mass with respect to 100 parts by mass of the total amount of the silicon compound. When the addition amount of the thermohydrolyzable compound (urea or the like) is 1 part by mass or more, good reactivity can be further easily obtained, and when it is 200 parts by mass or less, the precipitation of crystals and the gel density are reduced. It becomes easy to suppress the decrease.
　ゾル生成工程の加水分解は、混合液中のケイ素化合物、シリカ粒子、酸触媒、界面活性剤等の種類及び量にも左右されるが、例えば、２０～６０℃の温度環境下で１０分～２４時間行ってもよく、５０～６０℃の温度環境下で５分～８時間行ってもよい。これにより、ケイ素化合物中の加水分解性官能基が充分に加水分解され、ケイ素化合物の加水分解生成物を更に確実に得ることができる。 The hydrolysis in the sol production step depends on the types and amounts of silicon compound, silica particles, acid catalyst, surfactant, etc. in the mixed solution, but for example, 10 minutes to 20-60 ° C. in a temperature environment. The reaction may be performed for 24 hours, or in a temperature environment of 50 to 60 ° C. for 5 minutes to 8 hours. Thereby, the hydrolyzable functional group in a silicon compound is fully hydrolyzed, and the hydrolysis product of a silicon compound can be obtained more reliably.
　溶媒中に熱加水分解性化合物を添加する場合は、ゾル生成工程の温度環境を、熱加水分解性化合物の加水分解を抑制してゾルのゲル化を抑制する温度に調節してもよい。この時の温度は、熱加水分解性化合物の加水分解を抑制できる温度であれば、いずれの温度であってもよい。例えば、ゾル生成工程の温度環境（例えば、熱加水分解性化合物として尿素を用いた場合の温度環境）は、０～４０℃であってもよく、１０～３０℃であってもよい。 When adding a thermohydrolyzable compound in the solvent, the temperature environment of the sol generation step may be adjusted to a temperature that suppresses hydrolysis of the thermohydrolyzable compound and suppresses gelation of the sol. The temperature at this time may be any temperature as long as the hydrolysis of the thermally hydrolyzable compound can be suppressed. For example, the temperature environment in the sol production step (for example, the temperature environment when urea is used as the thermohydrolyzable compound) may be 0 to 40 ° C. or 10 to 30 ° C.
　塩基触媒としては、水酸化リチウム、水酸化ナトリウム、水酸化カリウム、水酸化セシウム等のアルカリ金属水酸化物；水酸化アンモニウム、フッ化アンモニウム、塩化アンモニウム、臭化アンモニウム等のアンモニウム化合物；メタリン酸ナトリウム、ピロリン酸ナトリウム、ポリリン酸ナトリウム等の塩基性リン酸ナトリウム塩；アリルアミン、ジアリルアミン、トリアリルアミン、イソプロピルアミン、ジイソプロピルアミン、エチルアミン、ジエチルアミン、トリエチルアミン、２－エチルヘキシルアミン、３－エトキシプロピルアミン、ジイソブチルアミン、３－（ジエチルアミノ）プロピルアミン、ジ－２－エチルヘキシルアミン、３－（ジブチルアミノ）プロピルアミン、テトラメチルエチレンジアミン、ｔ－ブチルアミン、ｓｅｃ－ブチルアミン、プロピルアミン、３－（メチルアミノ）プロピルアミン、３－（ジメチルアミノ）プロピルアミン、３－メトキシアミン、ジメチルエタノールアミン、メチルジエタノールアミン、ジエタノールアミン、トリエタノールアミン等の脂肪族アミン類；モルホリン、Ｎ－メチルモルホリン、２－メチルモルホリン、ピペラジン及びその誘導体、ピペリジン及びその誘導体、イミダゾール及びその誘導体等の含窒素複素環状化合物類などが挙げられる。これらの中でも、揮発性が高く、乾燥後のエアロゲル層に残存し難いため耐水性を損なわない観点、及び、経済性の観点から、水酸化アンモニウム（アンモニア水）を用いることができる。塩基触媒は、単独で又は２種類以上を混合して用いてもよい。 Base catalysts include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and cesium hydroxide; ammonium compounds such as ammonium hydroxide, ammonium fluoride, ammonium chloride, and ammonium bromide; sodium metaphosphate Basic sodium phosphates such as sodium pyrophosphate and sodium polyphosphate; allylamine, diallylamine, triallylamine, isopropylamine, diisopropylamine, ethylamine, diethylamine, triethylamine, 2-ethylhexylamine, 3-ethoxypropylamine, diisobutylamine, 3- (diethylamino) propylamine, di-2-ethylhexylamine, 3- (dibutylamino) propylamine, tetramethylethylenediamine, t-butylamine aliphatic amines such as sec-butylamine, propylamine, 3- (methylamino) propylamine, 3- (dimethylamino) propylamine, 3-methoxyamine, dimethylethanolamine, methyldiethanolamine, diethanolamine, triethanolamine; morpholine N-methylmorpholine, 2-methylmorpholine, piperazine and derivatives thereof, piperidine and derivatives thereof, nitrogen-containing heterocyclic compounds such as imidazole and derivatives thereof, and the like. Among these, ammonium hydroxide (ammonia water) can be used from the viewpoint of high volatility and hardly remaining in the airgel layer after drying, and from the viewpoint of not impairing water resistance and economical efficiency. You may use a base catalyst individually or in mixture of 2 or more types.
　塩基触媒を用いることで、ゾル中のケイ素化合物（ポリシロキサン化合物群及びケイ素化合物群）、及び、シリカ粒子の脱水縮合反応及び／又は脱アルコール縮合反応を促進することができ、ゾルのゲル化を更に短時間で行うことができる。特に、アンモニアは、揮発性が高く、構造体に残留し難い。そのため、塩基触媒としてアンモニアを用いることで、耐水性の更に優れた構造体を得ることができる。 By using a base catalyst, the dehydration condensation reaction and / or dealcoholization condensation reaction of the silicon compound (polysiloxane compound group and silicon compound group) and silica particles in the sol can be promoted, and the gelation of the sol Furthermore, it can be performed in a short time. In particular, ammonia is highly volatile and hardly remains in the structure. Therefore, by using ammonia as the base catalyst, a structure having further excellent water resistance can be obtained.
　塩基触媒の添加量は、ケイ素化合物（ポリシロキサン化合物群及びケイ素化合物群）の総量１００質量部に対し、０．５～５質量部であってもよく、１～４質量部であってもよい。塩基触媒の添加量が０．５質量部以上であることにより、ゲル化を更に短時間で行うことができ、５質量部以下であることにより、撥水性が向上する。 The addition amount of the base catalyst may be 0.5 to 5 parts by mass or 1 to 4 parts by mass with respect to 100 parts by mass of the total amount of silicon compounds (polysiloxane compound group and silicon compound group). . When the addition amount of the base catalyst is 0.5 parts by mass or more, gelation can be performed in a shorter time, and when it is 5 parts by mass or less, the water repellency is improved.
　ゾル生成工程におけるゾルゲル反応は、接触工程において良好な塗膜性を得る目的から、半ゲル化状態のゾルを得ることができる。この反応は、溶媒及び塩基触媒が揮発しないように密閉容器内で行うことができる。ゲル化温度は、ゾル中のケイ素化合物、シリカ粒子、酸触媒、界面活性剤、塩基触媒などの種類及び量にも左右されるが、３０～９０℃であってもよく、４０～８０℃であってもよい。ゲル化温度が３０℃以上であることにより、ゲル化を更に短時間に行うことができる。ゲル化温度が９０℃以下であることにより、急なゲル化を抑制することができる。 The sol-gel reaction in the sol production step can obtain a sol in a semi-gelled state for the purpose of obtaining good coating properties in the contact step. This reaction can be performed in an airtight container so that a solvent and a base catalyst may not volatilize. The gelation temperature depends on the type and amount of the silicon compound, silica particles, acid catalyst, surfactant, base catalyst and the like in the sol, but may be 30 to 90 ° C. or 40 to 80 ° C. There may be. When the gelation temperature is 30 ° C. or higher, gelation can be performed in a shorter time. When the gelation temperature is 90 ° C. or less, rapid gelation can be suppressed.
　ゾルゲル反応の時間は、ゲル化温度により異なるが、本実施形態においてはゾル中にシリカ粒子を含有する場合は、従来のエアロゲルに適用されるゾルと比較して、ゲル化時間を短縮することができる。この理由は、ゾル中のケイ素化合物が有する加水分解性の官能基又は縮合性の官能基が、シリカ粒子のシラノール基と水素結合及び／又は化学結合を形成するためであると推察する。なお、ゲル化時間は、１０～３６０分であってもよく、２０～１８０分であってもよい。ゲル化時間が１０分以上であることにより、ゾルの粘度が向上し、接触工程において良好な塗工性を得易くなり、３６０分以下であることにより、ゾルの完全ゲル化を抑制し、本体部又は被覆層との接着性を得易くなる。 Although the sol-gel reaction time varies depending on the gelation temperature, in the present embodiment, when silica particles are contained in the sol, the gelation time may be shortened as compared with a sol applied to a conventional aerogel. it can. The reason for this is presumed that the hydrolyzable functional group or the condensable functional group of the silicon compound in the sol forms hydrogen bonds and / or chemical bonds with the silanol groups of the silica particles. The gelation time may be 10 to 360 minutes or 20 to 180 minutes. When the gelation time is 10 minutes or longer, the viscosity of the sol is improved, and good coating properties are easily obtained in the contact process. It becomes easy to obtain adhesiveness with a part or a coating layer.
｛接触工程｝
　接触工程は、上記ゾル生成工程で得られたゾル塗液（半ゲル化状態のゾル塗液等）を、ミスト状の形態で本体部又は被覆層に接触させ、構造体を作製する工程（塗工工程等）である。具体的には、上記ゾル塗液をミスト状の形態で本体部又は被覆層に接触させ、必要に応じ加熱及び乾燥することによりゾル塗液をゲル化させてエアロゲル層を本体部又は被覆層の表面に形成する。ただし、このエアロゲル層は、本体部又は被覆層との接着力が確保される状態であることが望ましい。 {Contact process}
In the contact step, the sol coating liquid (semi-gelled sol coating liquid or the like) obtained in the sol generation step is brought into contact with the main body or the coating layer in the form of a mist to produce a structure (coating). Construction process). Specifically, the sol coating liquid is brought into contact with the main body part or the coating layer in the form of a mist, and the sol coating liquid is gelled by heating and drying as necessary to form the airgel layer of the main body part or the coating layer. Form on the surface. However, the airgel layer is desirably in a state in which an adhesive force with the main body portion or the coating layer is ensured.
　接触方法（塗工方法等）は、上記ゾルを、ミスト状の形態で本体部又は層に接触（塗布）させることができれば、特に制限はないが、例えば、スプレー塗布が挙げられる。当該方法によれば、スプレーにより発生したミストが、塗工対象面に到達すればよいため、例えば、配管のような筒状の本体部の内面に対しても、エアロゲル層を形成することができる。 The contact method (coating method and the like) is not particularly limited as long as the sol can be contacted (applied) to the main body or the layer in a mist form, and examples thereof include spray coating. According to this method, since the mist generated by spraying only needs to reach the surface to be coated, for example, an airgel layer can be formed also on the inner surface of a cylindrical main body such as a pipe. .
　スプレー塗布に用いられるスプレーとしては、例えば、圧縮ガスによりゾルをミスト化して塗工するエアスプレー、ゾルに圧力をかけてスプレーガンの噴出口からミスト化したゾルを塗出するエアレススプレー、ゾルに静電圧をかけてミストを効率良く被着体に付着させる液体静電スプレーが挙げられる。 Examples of sprays used for spray coating include air spray that mists are applied by applying compressed gas, and airless sprays that apply mist by applying pressure to the sol and spray mist from the spray gun. A liquid electrostatic spray that efficiently attaches a mist to an adherend by applying a static voltage can be used.
　塗工方式は制限されず、本体部又は被覆層の大きさ、形状、弾性率等の物理的性状により、好適な手法を選択できる。 The coating method is not limited, and a suitable method can be selected according to physical properties such as the size, shape, and elastic modulus of the main body or the coating layer.
　スプレーにガスを使用する場合、使用するガスの圧力は、例えば、用いるエアーガン及びエアーブラシの仕様に従って調整することができる。当該圧力は、特に制限されないが、例えば、０．５ＭＰａ未満であってもよい。 When using gas for spraying, the pressure of the gas used can be adjusted according to the specifications of the air gun and air brush used, for example. The pressure is not particularly limited, but may be, for example, less than 0.5 MPa.
　接触工程において形成されるエアロゲル層の厚みは、例えば、スプレーに用いるガスの圧力、ゾルの塗出量、ゾルの粘度、スプレーと本体部との距離及び塗工時間により調整できる。中でも、エアロゲル層の厚みは、作業性の観点から、塗工時間によって調整してもよい。この場合、例えば、塗工時間と、半硬化ゲルの厚み又はエアロゲル層の厚みとの関係性を示す検量線を作成し、これにより厚みを制御してもよい。 The thickness of the airgel layer formed in the contacting step can be adjusted by, for example, the pressure of the gas used for spraying, the coating amount of the sol, the viscosity of the sol, the distance between the spray and the main body, and the coating time. Among these, the thickness of the airgel layer may be adjusted by the coating time from the viewpoint of workability. In this case, for example, a calibration curve indicating the relationship between the coating time and the thickness of the semi-cured gel or the thickness of the airgel layer may be created, and thereby the thickness may be controlled.
　ミスト状のゾルの液滴の直径は、厚膜のエアロゲル層を形成し易い観点及びエアロゲル層のクラックを更に抑制する観点から、０．１μｍ以上であってもよく、０．３μｍ以上であってもよく、０．５μｍ以上であってもよい。同様の観点から、ゾルの液滴の直径は、１０００μｍ以下であってもよく、８００μｍ以下であってもよく、５００μｍ以下であってもよい。これらの観点から、ゾルの液滴の直径は、０．１～１０００μｍであってもよく、０．３～８００μｍであってもよく、０．５～５００μｍであってもよい。液滴の直径がこのような範囲である場合に、厚膜のエアロゲル層を形成し易く、エアロゲル層のクラックを更に抑制できる理由は、例えば、このようなサイズの液滴は、表面積が充分に大きいため、本体部又は被覆層上に付着した後、ゾル中の溶媒が短時間で蒸発し、これに伴いゾルが収縮するためであると推察する。 The diameter of the mist droplets of the sol may be 0.1 μm or more, from the viewpoint of easily forming a thick airgel layer and further suppressing cracking of the airgel layer, and may be 0.3 μm or more. It may be 0.5 μm or more. From the same viewpoint, the diameter of the sol droplet may be 1000 μm or less, 800 μm or less, or 500 μm or less. From these viewpoints, the diameter of the sol droplet may be 0.1 to 1000 μm, 0.3 to 800 μm, or 0.5 to 500 μm. When the diameter of the droplet is in such a range, it is easy to form a thick airgel layer and the crack of the airgel layer can be further suppressed. For example, a droplet having such a size has a sufficient surface area. Since it is large, it is assumed that the solvent in the sol evaporates in a short time after adhering to the main body or the coating layer, and the sol contracts accordingly.
　エアロゲル層を形成する部分（塗工部分）と、形成しない部分（非塗工部分）と、が隣接する場合には、例えば、テープ等により非塗工部分をマスキングした後に、塗工部分にゾルを接触させてもよい。 If the airgel layer forming part (coating part) and the non-forming part (non-coating part) are adjacent, for example, the non-coating part is masked with a tape or the like, and then the sol is applied to the coating part. May be contacted.
　マスキングを施した場合には、塗工部分と非塗工部分との境界部分におけるエアロゲルの欠落及び剥離を低減する観点から、例えば、スプレー塗工した後、半硬化ゲル状のタイミングでマスクを除去してもよい。 When masking is applied, from the viewpoint of reducing airgel loss and peeling at the boundary between the coated and non-coated areas, for example, after spray coating, the mask is removed at a semi-cured gel-like timing. May be.
　接触工程において、加熱及び乾燥を施す場合、これらの条件は、エアロゲル層と本体部又は被覆層との接着性が得易い観点から、例えば、加熱及び乾燥後のエアロゲル層の含水率が１０質量％以上となるような条件であってもよく、５０質量％以上となるような条件であってもよい。 In the contact step, when heating and drying, these conditions are such that the moisture content of the airgel layer after heating and drying is, for example, 10% by mass from the viewpoint of easily obtaining adhesion between the airgel layer and the main body portion or the coating layer. The conditions may be as described above, or the conditions may be 50% by mass or more.
　加熱及び乾燥温度は、ゾル塗液中の水分量、有機溶媒量、有機溶媒の沸点等の条件によっても異なるが、ゲル化時間を短縮する観点から、例えば、５０℃以上であってもよく、６０℃以上であってもよい。加熱及び乾燥温度は、エアロゲル層と本体部又は被覆層との接着性を得易い観点から、例えば、１５０℃以下であってもよく、１２０℃以下であってもよい。これらの観点から、加熱及び乾燥温度は、例えば、５０～１５０℃であってもよく、６０～１２０℃であってもよい。 The heating and drying temperature varies depending on conditions such as the amount of water in the sol coating liquid, the amount of the organic solvent, the boiling point of the organic solvent, etc., from the viewpoint of shortening the gelation time, for example, may be 50 ° C. It may be 60 ° C. or higher. The heating and drying temperature may be, for example, 150 ° C. or less or 120 ° C. or less from the viewpoint of easily obtaining adhesion between the airgel layer and the main body portion or the coating layer. From these viewpoints, the heating and drying temperature may be, for example, 50 to 150 ° C. or 60 to 120 ° C.
　加熱及び乾燥時間は、加熱及び乾燥温度によって異なるが、エアロゲル層の形成の容易性の観点から、例えば、０．２分以上であってもよく、０．５分以上であってもよい。加熱及び乾燥時間は、エアロゲル層と本体部又は被覆層との接着性を得易い観点から、例えば、１０分以下であってもよく、８分以下であってもよい。これらの観点から、加熱及び乾燥時間は、例えば、０．２～１０分であってもよく、０．５～８分であってもよい。加熱及び乾燥条件は、例えば、予め簡単な実験をすることにより、好適な条件を適宜設定することができる。 The heating and drying time varies depending on the heating and drying temperature, but may be, for example, 0.2 minutes or more, or 0.5 minutes or more from the viewpoint of ease of forming the airgel layer. The heating and drying time may be, for example, 10 minutes or less or 8 minutes or less from the viewpoint of easily obtaining the adhesion between the airgel layer and the main body portion or the coating layer. From these viewpoints, the heating and drying time may be, for example, 0.2 to 10 minutes or 0.5 to 8 minutes. As for the heating and drying conditions, for example, suitable conditions can be appropriately set by conducting a simple experiment in advance.
　エアロゲル層の厚膜化の観点から、塗工及び乾燥を複数回繰り返してもよい。塗工と乾燥とを繰り返すことで、加熱及び乾燥後のエアロゲル層の含水率を調整し易く、かつ容易に厚膜化することができる。 From the viewpoint of increasing the thickness of the airgel layer, coating and drying may be repeated a plurality of times. By repeating the coating and drying, it is easy to adjust the moisture content of the airgel layer after heating and drying, and the film can be easily thickened.
｛熟成工程｝
　熟成工程は、上記接触工程により得られた構造体を、加熱にて熟成させる工程である。熟成工程において、熟成後のエアロゲル層の含水率は、エアロゲル層と本体部又は被覆層との接着性の低下を抑制する観点から、１０質量％以上であってもよく、５０質量％以上であってもよい。熟成方法は、特に制限されないが、例えば、構造体を密閉雰囲気で熟成する方法、及び、加熱による含水率の低下を抑制できる恒湿恒温槽等を用いて熟成する方法が挙げられる。 {Aging process}
The aging step is a step of aging the structure obtained by the contact step by heating. In the aging step, the moisture content of the airgel layer after aging may be 10% by mass or more, or 50% by mass or more from the viewpoint of suppressing a decrease in adhesiveness between the airgel layer and the main body portion or the coating layer. May be. The aging method is not particularly limited, and examples thereof include a method of aging the structure in a sealed atmosphere, and a method of aging using a constant temperature and humidity bath that can suppress a decrease in moisture content due to heating.
　熟成温度は、例えば、４０～９０℃であってもよく、５０～８０℃であってもよい。熟成温度が４０℃以上であることにより、熟成時間を短縮でき、９０℃以下であることにより、含水量の低下を抑制できる。 The aging temperature may be, for example, 40 to 90 ° C. or 50 to 80 ° C. When the aging temperature is 40 ° C. or higher, the aging time can be shortened, and when it is 90 ° C. or lower, a decrease in water content can be suppressed.
　熟成時間は、例えば、１～４８時間であってもよく、３～２４時間であってもよい。熟成時間が１時間以上であることにより、優れた断熱性を容易に得ることができ、４８時間以下であることにより、エアロゲル層と本体部又は被覆層との高い接着性を得ることができる。 The aging time may be, for example, 1 to 48 hours, or 3 to 24 hours. When the aging time is 1 hour or longer, excellent heat insulating properties can be easily obtained, and when it is 48 hours or shorter, high adhesion between the airgel layer and the main body portion or the coating layer can be obtained.
｛洗浄及び溶媒置換工程｝
　洗浄及び溶媒置換工程は、上記熟成工程により得られた構造体を洗浄する工程（洗浄工程）と、乾燥工程に適した溶媒に置換する工程（溶媒置換工程）とを有する工程である。洗浄及び溶媒置換手法は、特に制限はされず、例えば、コンベア搬送にて洗浄槽及び／又は溶媒置換槽等を複数個用いて連続処理することができる。洗浄及び溶媒置換工程は、構造体を洗浄する工程を行わず、溶媒置換工程のみを行う形態でも実施可能であるが、エアロゲル層中の未反応物、副生成物等の不純物を低減し、より純度の高い構造体の製造を可能にする観点から、エアロゲル層を洗浄することができる。 {Washing and solvent replacement step}
The washing and solvent substitution step is a step having a step of washing the structure obtained by the aging step (washing step) and a step of substitution with a solvent suitable for the drying step (solvent substitution step). The cleaning and solvent replacement method is not particularly limited, and for example, continuous processing can be performed using a plurality of cleaning tanks and / or solvent replacement tanks by conveyor conveyance. The cleaning and solvent replacement step can be carried out in a form in which only the solvent replacement step is performed without performing the step of cleaning the structure, but it is possible to reduce impurities such as unreacted substances and by-products in the airgel layer. The airgel layer can be washed from the viewpoint of enabling production of a highly pure structure.
　洗浄工程では、上記熟成工程で得られた構造体に対し、水又は有機溶媒を用いて繰り返し洗浄することができる。 In the washing step, the structure obtained in the aging step can be repeatedly washed with water or an organic solvent.
　有機溶媒としては、メタノール、エタノール、１－プロパノール、２－プロパノール、１－ブタノール、アセトン、メチルエチルケトン、１，２－ジメトキシエタン、アセトニトリル、ヘキサン、トルエン、ジエチルエーテル、クロロホルム、酢酸エチル、テトラヒドロフラン、塩化メチレン、Ｎ，Ｎ－ジメチルホルムアミド、ジメチルスルホキシド、酢酸、ギ酸等の各種の有機溶媒を使用することができる。有機溶媒は、単独で又は２種類以上を混合して用いてもよい。 Organic solvents include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, acetone, methyl ethyl ketone, 1,2-dimethoxyethane, acetonitrile, hexane, toluene, diethyl ether, chloroform, ethyl acetate, tetrahydrofuran, methylene chloride , N, N-dimethylformamide, dimethyl sulfoxide, acetic acid, formic acid, and other various organic solvents can be used. You may use an organic solvent individually or in mixture of 2 or more types.
　溶媒置換工程では、乾燥によるエアロゲル層の収縮を抑制するため、低表面張力の溶媒が用いられることがある。しかし、低表面張力の溶媒は、一般的に水との相互溶解度が極めて低い。そのため、溶媒置換工程において低表面張力の溶媒を用いる場合、洗浄工程で用いる有機溶媒としては、水及び低表面張力の溶媒の双方に対して高い相互溶解性を有する親水性有機溶媒を用いることができる。なお、洗浄工程において用いられる親水性有機溶媒は、溶媒置換工程のための予備置換の役割を果たすことができる。このことから、上記の有機溶媒の中で、親水性有機溶媒である観点から、メタノール、エタノール、２－プロパノール、アセトン又はメチルエチルケトンを用いることが可能であり、経済性に優れる観点から、メタノール、エタノール又はメチルエチルケトンを用いることができる。 In the solvent replacement step, a low surface tension solvent may be used to suppress shrinkage of the airgel layer due to drying. However, low surface tension solvents generally have very low mutual solubility with water. Therefore, when a low surface tension solvent is used in the solvent replacement step, a hydrophilic organic solvent having high mutual solubility in both water and a low surface tension solvent is used as the organic solvent used in the washing step. it can. Note that the hydrophilic organic solvent used in the washing step can serve as a preliminary replacement for the solvent replacement step. Therefore, methanol, ethanol, 2-propanol, acetone, or methyl ethyl ketone can be used from the viewpoint of being a hydrophilic organic solvent among the above organic solvents, and methanol, ethanol can be used from the viewpoint of excellent economy. Alternatively, methyl ethyl ketone can be used.
　洗浄工程に使用される水又は有機溶媒の量としては、エアロゲル層中の溶媒を充分に置換し、洗浄できる量を用いることが可能であり、エアロゲル層の容量に対して３～１０倍の量の溶媒を用いることができる。洗浄は、洗浄後のエアロゲル層中の含水率が１０質量％以下となるまで繰り返すことができる。 The amount of water or organic solvent used in the washing step can be an amount that can sufficiently wash the solvent in the airgel layer and can be washed, and is 3 to 10 times the volume of the airgel layer. These solvents can be used. The washing can be repeated until the water content in the airgel layer after washing becomes 10% by mass or less.
　洗浄工程における温度環境としては、洗浄に用いる溶媒の沸点以下の温度を用いることができる。例えば、メタノールを用いる場合、３０～６０℃程度の温度を用いることができる。 As the temperature environment in the washing step, a temperature below the boiling point of the solvent used for washing can be used. For example, when methanol is used, a temperature of about 30 to 60 ° C. can be used.
　溶媒置換工程では、乾燥工程におけるエアロゲル層の収縮を抑制するため、洗浄したエアロゲル層の溶媒を所定の置換用溶媒に置き換えることができる。この際、加温することにより置換効率を向上させることができる。置換用溶媒としては、具体的には、乾燥工程において、乾燥に用いられる溶媒の臨界点未満の温度にて大気圧下で乾燥する場合は、後述の低表面張力の溶媒を用いることができる。超臨界乾燥を行う場合、例えば、エタノール、メタノール、２－プロパノール、ジクロロジフルオロメタン、二酸化炭素等の溶媒を単独で用いるか、又は、これらを２種以上混合した溶媒を用いることができる。 In the solvent replacement step, the solvent in the washed airgel layer can be replaced with a predetermined replacement solvent in order to suppress the shrinkage of the airgel layer in the drying step. At this time, the replacement efficiency can be improved by heating. Specifically, as the replacement solvent, a solvent having a low surface tension, which will be described later, can be used in the drying step when drying under atmospheric pressure at a temperature lower than the critical point of the solvent used for drying. When performing supercritical drying, for example, a solvent such as ethanol, methanol, 2-propanol, dichlorodifluoromethane, carbon dioxide, or the like can be used alone, or a solvent in which two or more of these are mixed can be used.
　低表面張力の溶媒としては、２０℃における表面張力が３０ｍＮ／ｍ以下の溶媒であってもよく、２５ｍＮ／ｍ以下の溶媒であってもよく、２０ｍＮ／ｍ以下の溶媒であってもよい。低表面張力の溶媒としては、例えば、ペンタン（１５．５）、ヘキサン（１８．４）、ヘプタン（２０．２）、オクタン（２１．７）、２－メチルペンタン（１７．４）、３－メチルペンタン（１８．１）、２－メチルヘキサン（１９．３）、シクロペンタン（２２．６）、シクロヘキサン（２５．２）、１－ペンテン（１６．０）等の脂肪族炭化水素類；ベンゼン（２８．９）、トルエン（２８．５）、ｍ－キシレン（２８．７）、ｐ－キシレン（２８．３）等の芳香族炭化水素類；ジクロロメタン（２７．９）、クロロホルム（２７．２）、四塩化炭素（２６．９）、１－クロロプロパン（２１．８）、２－クロロプロパン（１８．１）等のハロゲン化炭化水素類；エチルエーテル（１７．１）、プロピルエーテル（２０．５）、イソプロピルエーテル（１７．７）、ブチルエチルエーテル（２０．８）、１，２－ジメトキシエタン（２４．６）等のエーテル類；アセトン（２３．３）、メチルエチルケトン（２４．６）、メチルプロピルケトン（２５．１）、ジエチルケトン（２５．３）等のケトン類；及び酢酸メチル（２４．８）、酢酸エチル（２３．８）、酢酸プロピル（２４．３）、酢酸イソプロピル（２１．２）、酢酸イソブチル（２３．７）、エチルブチレート（２４．６）等のエステル類が挙げられる（かっこ内は２０℃での表面張力を示し、単位は［ｍＮ／ｍ］である）。これらの中で、低表面張力及び優れた作業環境性を達成する観点から、脂肪族炭化水素類であってもよく、ヘキサン又はヘプタンであってもよい。また、これらの中でも、アセトン、メチルエチルケトン、１，２－ジメトキシエタン等の親水性有機溶媒を用いることで、上記洗浄工程の有機溶媒と兼用することができる。なお、これらの中でも、乾燥工程における乾燥が容易な観点から、常圧での沸点が１００℃以下の溶媒を用いてもよい。低表面張力の溶媒は、単独で又は２種類以上を混合して用いてもよい。 The low surface tension solvent may be a solvent having a surface tension at 20 ° C. of 30 mN / m or less, a solvent of 25 mN / m or less, or a solvent of 20 mN / m or less. Examples of the low surface tension solvent include pentane (15.5), hexane (18.4), heptane (20.2), octane (21.7), 2-methylpentane (17.4), 3- Aliphatic hydrocarbons such as methylpentane (18.1), 2-methylhexane (19.3), cyclopentane (22.6), cyclohexane (25.2), 1-pentene (16.0); Aromatic hydrocarbons such as (28.9), toluene (28.5), m-xylene (28.7), p-xylene (28.3); dichloromethane (27.9), chloroform (27.2) ), Carbon tetrachloride (26.9), 1-chloropropane (21.8), 2-chloropropane (18.1) and other halogenated hydrocarbons; ethyl ether (17.1), propyl ether (20.5) ), Isop Ethers such as pyrether (17.7), butyl ethyl ether (20.8), 1,2-dimethoxyethane (24.6); acetone (23.3), methyl ethyl ketone (24.6), methyl propyl ketone (25.1), ketones such as diethyl ketone (25.3); and methyl acetate (24.8), ethyl acetate (23.8), propyl acetate (24.3), isopropyl acetate (21.2) And esters such as isobutyl acetate (23.7) and ethyl butyrate (24.6) (inside the surface tension at 20 ° C. is shown in parentheses, the unit is [mN / m]). Among these, from the viewpoint of achieving low surface tension and excellent working environment, aliphatic hydrocarbons may be used, and hexane or heptane may be used. Among these, by using a hydrophilic organic solvent such as acetone, methyl ethyl ketone, 1,2-dimethoxyethane, it can be used as the organic solvent in the washing step. Among these, a solvent having a boiling point of 100 ° C. or less at normal pressure may be used from the viewpoint of easy drying in the drying step. Low surface tension solvents may be used alone or in combination of two or more.
　溶媒置換工程に使用される溶媒の量としては、洗浄後のエアロゲル層中の溶媒を充分に置換できる量を用いることが可能であり、エアロゲル層の容量に対して３～１０倍の量の溶媒を用いることができる。 As the amount of the solvent used in the solvent replacement step, an amount capable of sufficiently replacing the solvent in the airgel layer after washing can be used, and the amount of the solvent is 3 to 10 times the volume of the airgel layer. Can be used.
　溶媒置換工程における温度環境としては、置換に用いる溶媒の沸点以下の温度を用いることができる。例えば、ヘプタンを用いる場合、３０～６０℃程度の温度を用いることができる。 As the temperature environment in the solvent replacement step, a temperature below the boiling point of the solvent used for the replacement can be used. For example, when heptane is used, a temperature of about 30 to 60 ° C. can be used.
　なお、本実施形態においては、ゾルがシリカ粒子を含有している場合は、溶媒置換工程は必ずしも必須ではない。推察されるメカニズムとしては次のとおりである。本実施形態においては、シリカ粒子が三次元網目状のエアロゲル骨格の支持体として機能することにより、当該骨格が支持され、乾燥工程におけるゲルの収縮が抑制される。そのため、洗浄に用いた溶媒を置換せずに、ゲルをそのまま乾燥工程に移すことができると考えられる。このように、本実施形態においては、洗浄及び溶媒置換工程～乾燥工程の簡略化が可能である。 In the present embodiment, when the sol contains silica particles, the solvent replacement step is not necessarily essential. The inferred mechanism is as follows. In the present embodiment, the silica particles function as a three-dimensional network airgel skeleton support, whereby the skeleton is supported and gel shrinkage in the drying process is suppressed. Therefore, it is considered that the gel can be directly transferred to the drying step without replacing the solvent used for washing. Thus, in the present embodiment, it is possible to simplify the washing and solvent replacement process to the drying process.
｛乾燥工程｝
　乾燥工程では、上記のとおり洗浄及び（必要に応じ）溶媒置換した構造体を乾燥させる。これにより、最終的な構造体を得ることができる。 {Drying process}
In the drying step, the structure that has been washed and solvent-substituted (if necessary) as described above is dried. Thereby, a final structure can be obtained.
　乾燥の手法としては特に制限されず、公知の常圧乾燥、超臨界乾燥又は凍結乾燥を用いることができる。これらの中で、低密度のエアロゲル層を製造し易い観点から、常圧乾燥又は超臨界乾燥を用いることができる。低コストで生産可能な観点から、常圧乾燥を用いることができる。なお、本実施形態において、「常圧」とは０．１ＭＰａ（大気圧）を意味する。 The drying method is not particularly limited, and known atmospheric pressure drying, supercritical drying, or freeze drying can be used. Among these, atmospheric drying or supercritical drying can be used from the viewpoint of easy production of a low-density airgel layer. From the viewpoint of being able to produce at low cost, atmospheric drying can be used. In the present embodiment, “normal pressure” means 0.1 MPa (atmospheric pressure).
　本実施形態に係る構造体は、例えば、洗浄及び（必要に応じ）溶媒置換した構造体を、乾燥に用いられる溶媒の臨界点未満の温度にて、大気圧下で乾燥することにより得ることができる。乾燥温度は、置換された溶媒（溶媒置換を行わない場合は洗浄に用いられた溶媒）の種類又は本体部の耐熱性により異なるが、６０～５００℃であってもよく、９０～１５０℃であってもよい。乾燥時間は、エアロゲル層の容量及び乾燥温度により異なるが、２～４８時間であってもよい。なお、本実施形態において、生産性を阻害しない範囲内において圧力をかけて乾燥を速めることもできる。 The structure according to the present embodiment can be obtained, for example, by drying a structure after washing and solvent substitution (if necessary) at a temperature below the critical point of the solvent used for drying under atmospheric pressure. it can. The drying temperature varies depending on the type of the substituted solvent (the solvent used for washing when solvent substitution is not performed) or the heat resistance of the main body, but may be 60 to 500 ° C., or 90 to 150 ° C. There may be. The drying time varies depending on the capacity of the airgel layer and the drying temperature, but may be 2 to 48 hours. In the present embodiment, drying can be accelerated by applying pressure within a range that does not impair productivity.
　本実施形態に係る構造体は、常圧乾燥における乾燥効率を向上させる観点から、乾燥工程の前にプレ乾燥を行ってもよい。プレ乾燥温度は、６０～１８０℃であってもよく、９０～１５０℃であってもよい。プレ乾燥時間は、エアロゲル層の容量及び乾燥温度により異なるが、１～３０分であってもよい。 The structure according to the present embodiment may be pre-dried before the drying step from the viewpoint of improving the drying efficiency in atmospheric drying. The predrying temperature may be 60 to 180 ° C, or 90 to 150 ° C. The pre-drying time varies depending on the volume of the airgel layer and the drying temperature, but may be 1 to 30 minutes.
　上述のとおり、乾燥の手法として、超臨界乾燥を用いることもできる。超臨界乾燥は、公知の手法にて行うことができる。超臨界乾燥する方法としては、例えば、エアロゲル層に含まれる溶媒の臨界点以上の温度及び圧力にて溶媒を除去する方法が挙げられる。あるいは、超臨界乾燥する方法としては、エアロゲル層を、液化二酸化炭素中に、例えば、２０～２５℃、５～２０ＭＰａ程度の条件で浸漬することで、エアロゲル層に含まれる溶媒の全部又は一部を該溶媒より臨界点の低い二酸化炭素に置換した後、二酸化炭素を単独で、又は、二酸化炭素及び溶媒の混合物を除去する方法が挙げられる。 As described above, supercritical drying can also be used as a drying method. Supercritical drying can be performed by a known method. Examples of the supercritical drying method include a method of removing the solvent at a temperature and pressure higher than the critical point of the solvent contained in the airgel layer. Alternatively, as a method of supercritical drying, the airgel layer is immersed in liquefied carbon dioxide under conditions of, for example, about 20 to 25 ° C. and about 5 to 20 MPa, so that all or part of the solvent contained in the airgel layer is used. And carbon dioxide having a lower critical point than that of the solvent, and then removing carbon dioxide alone or a mixture of carbon dioxide and the solvent.
　以上、本実施形態に係る構造体の製造方法の一実施形態について説明したが、構造体の製造方法は、本実施形態に限定されるものではない。また、本実施形態に係るエアロゲル層は、例えば、建築分野、衣料分野、自動車分野、家電分野、半導体分野、産業用設備等の撥水用途に適用できる。また、上記エアロゲル層は、撥水材としての用途の他にも、断熱用途、吸音用途、静振用途、触媒担持用途等に利用することもできる。 As mentioned above, although one Embodiment of the manufacturing method of the structure which concerns on this embodiment was described, the manufacturing method of a structure is not limited to this embodiment. Moreover, the airgel layer which concerns on this embodiment is applicable to water-repellent uses, such as an architecture field, a clothing field, a motor vehicle field, a household appliance field, a semiconductor field, an industrial facility, for example. Further, the airgel layer can be used for a heat insulating application, a sound absorbing application, a static vibration application, a catalyst supporting application and the like in addition to the application as a water repellent material.
　以下、実施例により本発明を更に詳しく説明するが、本発明はこれらの実施例に限定されるものではない。 Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
（本体部）
　本体部として、以下のガラス板、アルミニウム板、ＳＵＳ配管及びＰＥＴフィルムを準備した。 (Main body)
The following glass plate, aluminum plate, SUS piping and PET film were prepared as the main body.
ガラス板：テンパックス（株式会社東新理興製、寸法：１００ｍｍ×１００ｍｍ×２ｍｍ）
アルミニウム板：Ａ１０３５Ｐ（竹内金属箔粉工業株式会社製、寸法：１００ｍｍ×１００ｍｍ×０．５ｍｍ）
ＳＵＳ配管：ＳＵＳ３１６ＴＰＤ（モリ工業株式会社製、外径１１５ｍｍ×厚さ２ｍｍ×長さ５０ｍｍ）
ＰＥＴフィルム：テトロンＧ２（帝人株式会社、寸法：１００ｍｍ×１００ｍｍ×０．１ｍｍ） Glass plate: Tempax (manufactured by Toshin Rikou Co., Ltd., dimensions: 100 mm x 100 mm x 2 mm)
Aluminum plate: A1035P (manufactured by Takeuchi Metal Foil Powder Industry Co., Ltd., dimensions: 100 mm x 100 mm x 0.5 mm)
SUS piping: SUS316TPD (manufactured by Mori Kogyo Co., Ltd., outer diameter 115 mm × thickness 2 mm × length 50 mm)
PET film: Tetoron G2 (Teijin Limited, dimensions: 100 mm x 100 mm x 0.1 mm)
　なお、本体部としてＳＵＳ配管を用いる場合、後述のエアロゲル層（必要に応じ被覆層）の形成は、配管の外面に対して施した。 In addition, when using SUS piping as a main-body part, formation of the below-mentioned airgel layer (coating layer as needed) was given with respect to the outer surface of piping.
＜実施例１～７＞
（被覆層（以下、「中間層」ともいう）の形成）
　準備した各種本体部上に、表１に示す組み合わせで、以下のとおり中間層１及び中間層２を形成した。 <Examples 1 to 7>
(Formation of coating layer (hereinafter also referred to as “intermediate layer”))
An intermediate layer 1 and an intermediate layer 2 were formed on the prepared various main body portions in the combinations shown in Table 1 as follows.
［中間層１］
　本体部に、シリコーン系プライマ液としてのＫＢＭ－９０３（３－アミノプロピルトリメトキシシラン、信越化学工業株式会社製、製品名）を、エアーブラシ（アネスト岩田株式会社製、製品名：ＨＰ－ＣＰ）を用いて塗工した後、９０℃で１時間加熱して硬化させ、本体部上に、厚み５μｍの層（中間層１）を形成した。 [Intermediate layer 1]
KBM-903 (3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name) as a silicone-based primer liquid is applied to the main body, and an air brush (product name: HP-CP, manufactured by Anest Iwata Co., Ltd.). Then, the coating was cured by heating at 90 ° C. for 1 hour to form a 5 μm thick layer (intermediate layer 1) on the main body.
［中間層２］
　本体部に、無機系のプライマ液としてのケイ酸ナトリウム溶液（約３８質量％）（和光純薬工業株式会社製、試薬）を、バーコータを用いて塗工した後、３００℃で２時間加熱して硬化させ、本体部上に、厚み１０μｍの層（中間層２）を形成した。 [Intermediate layer 2]
After applying a sodium silicate solution (about 38% by mass) (made by Wako Pure Chemical Industries, Ltd., reagent) as an inorganic primer solution to the main body using a bar coater, heat at 300 ° C. for 2 hours. Then, a 10 μm thick layer (intermediate layer 2) was formed on the main body.
（ゾル塗液）
［ゾル塗液１］
　シリカ粒子含有原料としてＳＴ－ＯＸＳ（日産化学工業株式会社製、製品名、平均一次粒子径：５ｎｍ、固形分：１０質量％）を１００．０質量部、水を５０．０質量部、酸触媒として酢酸を０．１０質量部、カチオン系界面活性剤としてＣＴＡＢを２０．０質量部及び熱加水分解性化合物として尿素を１２０．０質量部混合して混合液を得た。この混合液に、ケイ素化合物としてメチルトリメトキシシラン（信越化学工業株式会社製、製品名：ＬＳ－５３０、以下「ＭＴＭＳ」と略記）を６０．０質量部及びジメチルジメトキシシラン（信越化学工業株式会社製、製品名：ＬＳ－５２０、以下「ＤＭＤＭＳ」と略記）を４０．０質量部加え、２５℃で２時間反応させた。その後、６０℃で５時間ゾルゲル反応させてゾル塗液１を得た。 (Sol coating liquid)
[Sol coating solution 1]
ST-OXS (manufactured by Nissan Chemical Industries, Ltd., product name, average primary particle size: 5 nm, solid content: 10% by mass) as silica particle-containing raw material 100.0 parts by mass, water 50.0 parts by mass, acid catalyst As a mixture, 0.10 parts by mass of acetic acid, 20.0 parts by mass of CTAB as a cationic surfactant and 120.0 parts by mass of urea as a thermohydrolyzable compound were mixed to obtain a mixed solution. In this mixed solution, 60.0 parts by mass of methyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product name: LS-530, hereinafter abbreviated as “MTMS”) as a silicon compound and dimethyldimethoxysilane (Shin-Etsu Chemical Co., Ltd.) (Product name: LS-520, hereinafter abbreviated as “DMDMS”) was added in an amount of 40.0 parts by mass, followed by reaction at 25 ° C. for 2 hours. Thereafter, a sol-gel reaction was performed at 60 ° C. for 5 hours to obtain a sol coating liquid 1.
［ゾル塗液２］
　シリカ粒子含有原料としてＳＴ－ＯＸＳを１００．０質量部、水を１００．０質量部、メタノールを１００．０質量部を混合して混合液を得た。この混合液に、ケイ素化合物としてＭＴＭＳを８０．０質量部及びＫＢＥ－２２（ジメチルジエトキシシラン、信越化学工業株式会社製、製品名）を６０．０質量部加え、２５℃で２時間反応させた。これに、塩基触媒として５％濃度のアンモニア水を５０．０質量部加えてゾル塗液２を得た。 [Sol coating liquid 2]
As a silica particle-containing raw material, 100.0 parts by mass of ST-OXS, 100.0 parts by mass of water, and 100.0 parts by mass of methanol were mixed to obtain a mixed solution. To this mixed solution, 80.0 parts by mass of MTMS as a silicon compound and 60.0 parts by mass of KBE-22 (dimethyldiethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name) are added and reacted at 25 ° C. for 2 hours. It was. A sol coating solution 2 was obtained by adding 50.0 parts by mass of 5% aqueous ammonia as a base catalyst.
［ゾル塗液３］
　シリカ粒子含有原料としてＳＴ－ＯＺＬ－３５（扶桑化学工業（株）製、製品名、平均一次粒子径：１００ｎｍ、固形分：３５質量％）を１００．０質量部、水を２００．０質量部、酸触媒として酢酸を０．１０質量部、カチオン系界面活性剤としてＣＴＡＢを２０．０質量部及び熱加水分解性化合物として尿素を１２０．０質量部混合して混合液を得た。この混合液に、ケイ素化合物としてＫＢＭ－３０６３（ヘキシルトリメトキシシラン、信越化学工業株式会社製、製品名）を８０．０質量部及びＫＢＭ－３０８６（１，８－ビス（トリメトキシシリル）オクタン、信越化学工業株式会社製、製品名）を８０．０質量部加え、２５℃で２時間反応させた。その後、６０℃で２時間ゾルゲル反応させてゾル塗液３を得た。 [Sol coating solution 3]
ST-OZL-35 (manufactured by Fuso Chemical Industry Co., Ltd., product name, average primary particle size: 100 nm, solid content: 35% by mass) as silica particle-containing raw material is 100.0 parts by mass, and water is 200.0 parts by mass. Then, 0.10 parts by mass of acetic acid as an acid catalyst, 20.0 parts by mass of CTAB as a cationic surfactant, and 120.0 parts by mass of urea as a thermohydrolyzable compound were mixed to obtain a mixed solution. To this mixed solution, 80.0 parts by mass of KBM-3063 (hexyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name) as a silicon compound and KBM-3086 (1,8-bis (trimethoxysilyl) octane, 80.0 parts by mass of Shin-Etsu Chemical Co., Ltd., product name) was added and reacted at 25 ° C. for 2 hours. Thereafter, a sol-gel reaction was performed at 60 ° C. for 2 hours to obtain a sol coating solution 3.
［ゾル塗液４］
　シリカ粒子含有原料としてＰＬ－２Ｌ（扶桑化学工業（株）製、製品名、平均一次粒子径：２０ｎｍ、固形分：２０質量％）を１００．０質量部、水を５０．０質量部、酸触媒として酢酸を０．１０質量部、カチオン系界面活性剤としてＣＴＡＢを２０．０質量部及び熱加水分解性化合物として尿素を１２０．０質量部混合して混合液を得た。この混合液に、ケイ素化合物としてＭＴＭＳを６０．０質量部とＫＢＭ－３０８６を８０．０質量部、及び上記一般式（Ａ）で表される構造を有するポリシロキサン化合物としてＫＦ－６００１（信越化学工業株式会社製、製品名）を３０．０質量部加え、２５℃で２時間反応させた。その後、６０℃で４時間ゾルゲル反応させてゾル塗液４を得た。 [Sol coating solution 4]
As a silica particle-containing raw material, PL-2L (manufactured by Fuso Chemical Industry Co., Ltd., product name, average primary particle size: 20 nm, solid content: 20% by mass) is 100.0 parts by mass, water is 50.0 parts by mass, acid 0.10 parts by mass of acetic acid as a catalyst, 20.0 parts by mass of CTAB as a cationic surfactant, and 120.0 parts by mass of urea as a thermohydrolyzable compound were mixed to obtain a mixed solution. In this mixed solution, 60.0 parts by mass of MTMS as a silicon compound, 80.0 parts by mass of KBM-3086, and KF-6001 (Shin-Etsu Chemical Co., Ltd.) as a polysiloxane compound having a structure represented by the above general formula (A) 30.0 parts by mass of a product name manufactured by Kogyo Co., Ltd. was added and reacted at 25 ° C. for 2 hours. Thereafter, a sol-gel reaction was performed at 60 ° C. for 4 hours to obtain a sol coating solution 4.
［ゾル塗液５］
　シリカ粒子含有原料としてＰＬ－２Ｌを１００．０質量部、水を１００．０質量部、酸触媒として酢酸を０．１０質量部、カチオン系界面活性剤としてＣＴＡＢを２０．０質量部及び熱加水分解性化合物として尿素を１２０．０質量部混合して混合液を得た。この混合液に、ケイ素化合物としてＭＴＭＳを４０．０質量部、ポリシロキサン化合物として上記一般式（Ｂ）で表される構造を有する両末端２官能アルコキシ変性ポリシロキサン化合物（以下、「ポリシロキサン化合物Ａ」という）を２０．０質量部加え、２５℃で２時間反応させた。その後、６０℃で５時間ゾルゲル反応させてゾル塗液５を得た。 [Sol coating solution 5]
100.0 parts by mass of PL-2L as a raw material containing silica particles, 100.0 parts by mass of water, 0.10 parts by mass of acetic acid as an acid catalyst, 20.0 parts by mass of CTAB as a cationic surfactant, and hot water addition As a decomposable compound, 120.0 parts by mass of urea was mixed to obtain a mixed solution. In this mixed solution, 40.0 parts by mass of MTMS as a silicon compound and a bifunctional alkoxy-modified polysiloxane compound having a structure represented by the above general formula (B) as a polysiloxane compound (hereinafter referred to as “polysiloxane compound A”). 20.0 parts by mass) was added and reacted at 25 ° C. for 2 hours. Thereafter, a sol-gel reaction was performed at 60 ° C. for 5 hours to obtain a sol coating solution 5.
　なお、上記「ポリシロキサン化合物Ａ」は次のようにして合成した。まず、撹拌機、温度計及びジムロート冷却管を備えた１Ｌの３つ口フラスコにて、両末端にシラノール基を有するジメチルポリシロキサン（モメンティブ社製、製品名：ＸＣ９６－７２３）を１００．０質量部、メチルトリメトキシシランを１８１．３質量部及びｔ－ブチルアミンを０．５０質量部混合し、３０℃で５時間反応させた。その後、この反応液を、１．３ｋＰａの減圧下、１４０℃で２時間加熱し、揮発分を除去することで、両末端２官能アルコキシ変性ポリシロキサン化合物（ポリシロキサン化合物Ａ）を得た。 The “polysiloxane compound A” was synthesized as follows. First, 100.0 mass of dimethylpolysiloxane (product name: XC96-723, manufactured by Momentive) having silanol groups at both ends in a 1 L three-necked flask equipped with a stirrer, a thermometer, and a Dimroth condenser. Parts, 181.3 parts by mass of methyltrimethoxysilane and 0.50 parts by mass of t-butylamine were mixed and reacted at 30 ° C. for 5 hours. Thereafter, this reaction solution was heated at 140 ° C. for 2 hours under reduced pressure of 1.3 kPa to remove volatile components, thereby obtaining a bifunctional alkoxy-modified polysiloxane compound (polysiloxane compound A) at both ends.
［ゾル塗液６］
　シリカ粒子含有原料としてＳＴ－ＯＺＬ－３５（扶桑化学工業（株）製、製品名、平均一次粒子径：１００ｎｍ、固形分：３５質量％）を１００．０質量部、水を１００．０質量部、酸触媒として酢酸を０．１０質量部、カチオン系界面活性剤としてＣＴＡＢを２０．０質量部及び熱加水分解性化合物として尿素を１２０．０質量部混合して混合液を得た。この混合液に、ケイ素化合物としてＫＢＭ－３０６３（ヘキシルトリメトキシシラン）を６０．０質量部、ポリシロキサン化合物として上記一般式（Ｂ）で表される構造を有する両末端２官能アルコキシ変性ポリシロキサン化合物（以下、「ポリシロキサン化合物Ｂ」という）を４０．０質量部加え、２５℃で２時間反応させた。その後、６０℃で５時間ゾルゲル反応させてゾル塗液６を得た。 [Sol coating liquid 6]
ST-OZL-35 (manufactured by Fuso Chemical Industry Co., Ltd., product name, average primary particle size: 100 nm, solid content: 35% by mass) as silica particle-containing raw material is 100.0 parts by mass, and water is 100.0 parts by mass. Then, 0.10 parts by mass of acetic acid as an acid catalyst, 20.0 parts by mass of CTAB as a cationic surfactant, and 120.0 parts by mass of urea as a thermohydrolyzable compound were mixed to obtain a mixed solution. In this mixed solution, 60.0 parts by mass of KBM-3063 (hexyltrimethoxysilane) as a silicon compound and a bifunctional alkoxy-modified polysiloxane compound having a structure represented by the above general formula (B) as a polysiloxane compound 40.0 parts by mass (hereinafter referred to as “polysiloxane compound B”) was added and reacted at 25 ° C. for 2 hours. Thereafter, a sol-gel reaction was performed at 60 ° C. for 5 hours to obtain a sol coating liquid 6.
　なお、上記「ポリシロキサン化合物Ｂ」は次のようにして合成した。まず、撹拌機、温度計及びジムロート冷却管を備えた１Ｌの３つ口フラスコにて、ＸＣ９６－７２３を１００．０質量部、テトラメトキシシランを２０２．６質量部及びｔ－ブチルアミンを０．５０質量部混合し、３０℃で５時間反応させた。その後、この反応液を、１．３ｋＰａの減圧下、１４０℃で２時間加熱し、揮発分を除去することで、両末端３官能アルコキシ変性ポリシロキサン化合物（ポリシロキサン化合物Ｂ）を得た。 The “polysiloxane compound B” was synthesized as follows. First, 100.0 parts by mass of XC96-723, 202.6 parts by mass of tetramethoxysilane and 0.50 of t-butylamine in a 1 L three-necked flask equipped with a stirrer, a thermometer and a Dimroth condenser. Mass parts were mixed and reacted at 30 ° C. for 5 hours. Thereafter, this reaction solution was heated at 140 ° C. for 2 hours under a reduced pressure of 1.3 kPa to remove volatile components, thereby obtaining a trifunctional alkoxy-modified polysiloxane compound (polysiloxane compound B) at both ends.
［ゾル塗液７］
　シリカ粒子含有原料としてＳＴ－ＯＺＬ－３５を１００．０質量部、水を２００．０質量部、酸触媒として酢酸を０．１０質量部、カチオン系界面活性剤としてＣＴＡＢを２０．０質量部及び熱加水分解性化合物として尿素を１２０．０質量部混合して混合液を得た。この混合液に、ケイ素化合物としてＫＢＭ－３０６３（ヘキシルトリメトキシシラン）を８０．０質量部及びＤＭＤＭＳを４０．０質量部加え、２５℃で２時間反応させた。その後、６０℃で１．０時間ゾルゲル反応させてゾル塗液７を得た。 [Sol coating liquid 7]
100.0 parts by mass of ST-OZL-35 as a raw material containing silica particles, 200.0 parts by mass of water, 0.10 parts by mass of acetic acid as an acid catalyst, 20.0 parts by mass of CTAB as a cationic surfactant, and As a heat hydrolyzable compound, 120.0 parts by mass of urea was mixed to obtain a mixed solution. To this mixed solution, 80.0 parts by mass of KBM-3063 (hexyltrimethoxysilane) and 40.0 parts by mass of DMDMS were added as a silicon compound, and reacted at 25 ° C. for 2 hours. Thereafter, a sol-gel reaction was performed at 60 ° C. for 1.0 hour to obtain a sol coating liquid 7.
（構造体（以下、「エアロゲル複合構造体」ともいう）の作製）
　本体部又は中間層上に、表１に示す組み合わせで、以下のとおりエアロゲル層１～７を形成し、本体部と、当該本体部に直接又は中間層を介して一体的に接合されたエアロゲル層とを備えるエアロゲル複合構造体を作製した。 (Production of structure (hereinafter also referred to as “airgel composite structure”))
The airgel layers 1 to 7 are formed on the main body or the intermediate layer in the combinations shown in Table 1 as follows, and the airgel layer is integrally joined to the main body directly or via the intermediate layer. An airgel composite structure comprising:
［エアロゲル層１］
　ゾル塗液１を、本体部又は中間層上に、ゲル化後の厚みが２００μｍとなるようにスプレーガン（アネスト岩田株式会社製、製品名：Ｗ－５０－１２４ＢＰＧ）を用いて、ミスト状の形態で塗布し、６０℃で３０分ゲル化して構造体を得た。その後、得られた構造体を密閉容器に移し、６０℃で１２時間熟成した。 [Airgel layer 1]
Using a spray gun (manufactured by Anest Iwata Co., Ltd., product name: W-50-124BPG), the sol coating liquid 1 is formed in a mist shape on the main body or intermediate layer so that the thickness after gelation becomes 200 μm. It was applied in the form and gelled at 60 ° C. for 30 minutes to obtain a structure. Thereafter, the obtained structure was transferred to a sealed container and aged at 60 ° C. for 12 hours.
　その後、熟成した構造体を水２０００ｍＬに浸漬し、３０分かけて洗浄を行った。次に、メタノール２０００ｍＬに浸漬し、６０℃で３０分かけて洗浄を行った。メタノールによる洗浄を、新しいメタノールに交換しながら更に２回行った。次に、メチルエチルケトン２０００ｍＬに浸漬し、６０℃で３０分かけて溶媒置換を行った。メチルエチルケトンによる洗浄を新しいメチルエチルケトンに交換しながら更に２回行った。洗浄及び溶媒置換された構造体を、常圧下にて、１２０℃で６時間乾燥することで、上記一般式（４）及び（５）で表される構造を有するエアロゲルを含むエアロゲル層１（本体部に直接又は中間層を介して一体的に接合したエアロゲル層）を備えるエアロゲル複合構造体を得た。 Thereafter, the aged structure was immersed in 2000 mL of water and washed for 30 minutes. Next, it was immersed in 2000 mL of methanol and washed at 60 ° C. for 30 minutes. Washing with methanol was performed twice more while exchanging with fresh methanol. Next, it was immersed in 2000 mL of methyl ethyl ketone, and solvent substitution was performed at 60 ° C. for 30 minutes. Washing with methyl ethyl ketone was performed twice more while exchanging with new methyl ethyl ketone. The washed and solvent-substituted structure is dried at 120 ° C. for 6 hours under normal pressure, so that the airgel layer 1 including the airgel having the structure represented by the general formulas (4) and (5) (main body) An airgel composite structure provided with an airgel layer integrally bonded directly to the part or via an intermediate layer was obtained.
［エアロゲル層２］
　ゾル塗液２を、本体部又は中間層上に、ゲル化後の厚みが５００μｍとなるようにスプレーガンを用いて、ミスト状の形態で塗布し、６０℃で３０分ゲル化して構造体を得た。その後、得られた構造体を密閉容器に移し、６０℃で１２時間熟成した。 [Airgel layer 2]
The sol coating liquid 2 is applied in a mist form on the main body or intermediate layer using a spray gun so that the thickness after gelation is 500 μm, and the structure is gelled at 60 ° C. for 30 minutes. Obtained. Thereafter, the obtained structure was transferred to a sealed container and aged at 60 ° C. for 12 hours.
　その後、洗浄及び溶媒置換工程並びに乾燥工程を、「エアロゲル層１」に記載した方法と同様にして行い、上記一般式（４）及び（５）で表される構造を有するエアロゲルを含むエアロゲル層２（本体部に直接又は中間層を介して一体的に接合したエアロゲル層）を備えるエアロゲル複合構造体を得た。 Thereafter, the washing and solvent replacement step and the drying step are performed in the same manner as the method described in “Airgel layer 1”, and the airgel layer 2 includes the airgel having the structure represented by the general formulas (4) and (5). An airgel composite structure provided with (an airgel layer integrally bonded to the main body directly or via an intermediate layer) was obtained.
［エアロゲル層３］
　ゾル塗液３を、本体部又は中間層上に、ゲル化後の厚みが５０μｍとなるようにスプレーガンを用いて、ミスト状の形態で塗布し、６０℃で３０分ゲル化して構造体を得た。その後、得られた構造体を密閉容器に移し、６０℃で１２時間熟成した。 [Airgel layer 3]
The sol coating liquid 3 is applied on the main body or intermediate layer in a mist form using a spray gun so that the thickness after gelation becomes 50 μm, and gelled at 60 ° C. for 30 minutes to form a structure. Obtained. Thereafter, the obtained structure was transferred to a sealed container and aged at 60 ° C. for 12 hours.
　その後、洗浄及び溶媒置換工程並びに乾燥工程を、「エアロゲル層１」に記載した方法と同様にして行い、上記一般式（４）及び（５）で表される構造を有するエアロゲル層３（本体部に直接又は中間層を介して一体的に接合したエアロゲル層）を備えるエアロゲル複合構造体を得た。 Thereafter, the washing and solvent replacement step and the drying step are performed in the same manner as the method described in “Aerogel layer 1”, and the airgel layer 3 (main body portion) having the structure represented by the above general formulas (4) and (5) The airgel composite structure provided with an airgel layer integrally bonded directly or via an intermediate layer.
［エアロゲル層４］
　ゾル塗液１に代えてゾル塗液４を用いたこと及びゲル化後の厚みが１００μｍとなるようにしたこと以外は、「エアロゲル層１」に記載した方法と同様にして、上記一般式（１）、（１ａ）及び（４）で表される構造を有するエアロゲルを含有するエアロゲル層４（本体部に直接又は中間層を介して一体的に接合したエアロゲル層）を備えるエアロゲル複合構造体を得た。 [Aerogel layer 4]
Except that the sol coating solution 4 was used instead of the sol coating solution 1 and the thickness after gelation was 100 μm, the above general formula ( 1), an airgel composite structure including an airgel layer 4 (an airgel layer integrally bonded to a main body part directly or via an intermediate layer) containing an airgel having a structure represented by (1a) and (4) Obtained.
［エアロゲル層５］
　ゾル塗液１に代えてゾル塗液５を用いたこと及びゲル化後の厚みが３０μｍとなるようにしたこと以外は、「エアロゲル層１」に記載した方法と同様にして、上記一般式（２）、（３）、（４）及び（５）で表される構造を有するエアロゲルを含有するエアロゲル層５（本体部に直接又は中間層を介して一体的に接合したエアロゲル層）を備えるエアロゲル複合構造体を得た。 [Airgel layer 5]
Except for using the sol coating solution 5 in place of the sol coating solution 1 and adjusting the thickness after gelation to 30 μm, the above general formula ( 2), (3), (4) and the airgel provided with the airgel layer 5 (the airgel layer joined integrally to the main body part directly or through the intermediate layer) containing the airgel having the structure represented by (5) A composite structure was obtained.
［エアロゲル層６］
　ゾル塗液１に代えてゾル塗液６を用いたこと及びゲル化後の厚みが２５０μｍとなるようにしたこと以外は、「エアロゲル層１」に記載した方法と同様にして、上記一般式（２）及び（４）で表される構造を有するエアロゲルを含有するエアロゲル層６（本体部に直接又は中間層を介して一体的に接合したエアロゲル層）を備えるエアロゲル複合構造体を得た。 [Aerogel layer 6]
Except that the sol coating liquid 6 was used instead of the sol coating liquid 1 and that the thickness after gelation was 250 μm, the above general formula ( The airgel composite structure provided with the airgel layer 6 (the airgel layer integrally joined to the main body part directly or via the intermediate layer) containing the airgel having the structure represented by 2) and (4) was obtained.
［エアロゲル層７］
　ゾル塗液１に代えてゾル塗液７を用いたこと及びゲル化後の厚みが１００μｍとなるようにしたこと以外は、「エアロゲル層１」に記載した方法と同様にして、上記一般式（４）及び（５）で表される構造を有するエアロゲルを含有するエアロゲル層７（本体部に直接又は中間層を介して一体的に接合したエアロゲル層）を備えるエアロゲル複合構造体を得た。 [Airgel layer 7]
Except that the sol coating liquid 7 was used instead of the sol coating liquid 1 and the thickness after gelation was 100 μm, the above general formula ( An airgel composite structure provided with an airgel layer 7 (an airgel layer integrally joined to the main body directly or via an intermediate layer) containing an airgel having the structure represented by 4) and (5) was obtained.
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000012
＜比較例１＞
　本体部としてのガラス板に、厚みが１００μｍになるように発泡ウレタンフォーム（ヘンケルジャパン株式会社製、製品名：シスタ　Ｍ５２３０）を塗布し、発泡ウレタンフォーム構造体を得た。 <Comparative Example 1>
A foamed urethane foam structure was obtained by applying a foamed urethane foam (manufactured by Henkel Japan Co., Ltd., product name: Sista M5230) to a glass plate as the main body so as to have a thickness of 100 μm.
　（比較例２）
　ゾル塗液１をバットに入れ、本体部としてのアルミ板をゾル塗液１に浸した後に取り出し、６０℃で３０分ゲル化して、ゲル層の厚みが２００μｍの構造体を得た。その後、得られた構造体を密閉容器に移し、６０℃で１２時間熟成した。 (Comparative Example 2)
The sol coating liquid 1 was put in a vat, and an aluminum plate as a main body was immersed in the sol coating liquid 1 and taken out, and gelled at 60 ° C. for 30 minutes to obtain a structure having a gel layer thickness of 200 μm. Thereafter, the obtained structure was transferred to a sealed container and aged at 60 ° C. for 12 hours.
　その後、洗浄及び溶媒置換工程並びに乾燥工程を、「エアロゲル層１」に記載した方法と同様にして行い、エアロゲル層Ｘ１を備えるエアロゲル複合構造体を得た。 Thereafter, the washing and solvent replacement step and the drying step were performed in the same manner as described in “Airgel layer 1” to obtain an airgel composite structure including the airgel layer X1.
　（比較例３）
　ゾル塗液１を、刷毛で、本体部としてのＳＵＳ配管に塗工し、６０℃で３０分ゲル化して、ゲル層の厚みが２００μｍの構造体を得た。その後、得られた構造体を密閉容器に移し、６０℃で１２時間熟成した。 (Comparative Example 3)
The sol coating liquid 1 was applied to a SUS pipe as a main body with a brush and gelled at 60 ° C. for 30 minutes to obtain a structure having a gel layer thickness of 200 μm. Thereafter, the obtained structure was transferred to a sealed container and aged at 60 ° C. for 12 hours.
　その後、洗浄及び溶媒置換工程並びに乾燥工程を、「エアロゲル層１」に記載した方法と同様にして行い、エアロゲル層Ｙ１を備えるエアロゲル複合構造体を得た。 Thereafter, the washing and solvent replacement step and the drying step were performed in the same manner as described in “Airgel layer 1” to obtain an airgel composite structure including the airgel layer Y1.
＜各種評価＞
（撥水性評価）
　各実施例で得られたエアロゲル複合構造体、及び、各比較例で得られた構造体について、エアロゲル層及び発泡ウレタンフォーム層が水平になるように置き、マイクロシリンジで１００μＬの純水を垂らし、１０秒間静置してからエアロゲル層及び発泡ウレタンフォーム層が水平に対して３０°の角度となるように傾け、水滴を除去した。このとき、目視で水滴が残らなかったものを「Ａ」、目視で構造体上に残った水滴が垂らした水滴の１０体積％未満であるものを「Ｂ」、目視で構造体上に残った水滴が垂らした水滴の１０体積％以上であるものを「Ｃ」として評価した。 <Various evaluations>
(Water repellency evaluation)
For the airgel composite structure obtained in each example and the structure obtained in each comparative example, the airgel layer and the foamed urethane foam layer were placed horizontally, and 100 μL of pure water was dropped with a microsyringe, After leaving still for 10 seconds, the airgel layer and the foamed urethane foam layer were tilted so as to have an angle of 30 ° with respect to the horizontal to remove water droplets. At this time, “A” indicates that no water droplets remain visually, “B” indicates that the water droplets remaining on the structure are less than 10% by volume of the dropped water droplets, and remained on the structure visually. What was 10 volume% or more of the water drop which the water drop hung was evaluated as "C".
（外観評価）
　各実施例で得られたエアロゲル複合構造体及び各比較例で得られた構造体のエアロゲル層、発泡ウレタンフォーム層に対して目視評価を行った。塗工面内で最大面積である色あいが、塗工面の９５％以上かつφ２ｍｍ以上大きさの色ムラがないものを「Ａ」、５０％以上９５％未満かつφ２ｍｍ以上の大きさの色ムラがないものを「Ｂ」、５０％未満かつφ２ｍｍ以上の大きさの色ムラがあるものを「Ｃ」とした。 (Appearance evaluation)
The airgel composite structure obtained in each example and the airgel layer and the foamed urethane foam layer of the structure obtained in each comparative example were visually evaluated. "A" when the maximum color area on the coated surface is 95% or more of the coated surface and there is no color unevenness of φ2 mm or more, and there is no color unevenness of 50% or more and less than 95% and φ2 mm or more “B” was defined as “B”, and “C” was defined as having color unevenness of less than 50% and φ2 mm or more.
（耐熱性評価）
　各実施例で得られたエアロゲル複合構造体及び各比較例で得られた構造体についてエアロゲル層又は発泡ウレタンフォーム層が下面となるように、表面温度２００℃のホットプレートに配置して、２００℃で５分間加熱した。加熱後、目視観察し、変形、変色、剥離等の外観を評価した。目視観察で変化が無いものを耐熱性良好と判定し、変形、変色、剥離等が生じたものを耐熱性不良と判定した。 (Heat resistance evaluation)
The airgel composite structure obtained in each example and the structure obtained in each comparative example were placed on a hot plate having a surface temperature of 200 ° C. so that the airgel layer or the foamed urethane foam layer was on the lower surface, and 200 ° C. For 5 minutes. After heating, visual observation was performed and appearance such as deformation, discoloration, and peeling was evaluated. Those having no change by visual observation were determined to have good heat resistance, and those having deformation, discoloration, peeling, etc. were determined to have poor heat resistance.
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000013
　表２から、実施例のエアロゲル複合構造体は、外観評価の結果に優れ、エアロゲル層のムラが抑制されたものであることがわかる。また、実施例のエアロゲル複合構造体は、撥水性及び耐熱性も良好である。そのため、高温環境で使用できる。 From Table 2, it can be seen that the airgel composite structures of the examples are excellent in appearance evaluation results, and the airgel layer unevenness is suppressed. In addition, the airgel composite structures of the examples also have good water repellency and heat resistance. Therefore, it can be used in a high temperature environment.
　一方、比較例１～３の構造体は、外観及び撥水性が劣っており、実施例と同等の効果は得られない。また、比較例１の構造体は、耐熱性も劣っている。 On the other hand, the structures of Comparative Examples 1 to 3 are inferior in appearance and water repellency, and the same effects as the examples cannot be obtained. Moreover, the structure of Comparative Example 1 is also inferior in heat resistance.
　３…本体部、３ａ…本体部の表面、５…エアロゲル層、５ａ…ゾル層、１０…対象物、１０ａ…対象物の表面、４…被覆層、４ａ…被覆層の本体部とは反対側の表面、１００，２００…構造体、Ｌ…外接長方形、Ｐ…シリカ粒子。 DESCRIPTION OF SYMBOLS 3 ... Main-body part, 3a ... Surface of main-body part, 5 ... Airgel layer, 5a ... Sol layer, 10 ... Target object, 10a ... Surface of target object, 4 ... Coating layer, 4a ... Opposite side to main-body part of coating layer Surface, 100, 200 ... structure, L ... circumscribed rectangle, P ... silica particles.

Claims (10)

  1. 　エアロゲル層が形成された構造体の製造方法であって、
    　ミスト状のゾルからエアロゲル層を形成する工程を備える、構造体の製造方法。     A method for producing a structure in which an airgel layer is formed,
    A method for producing a structure, comprising a step of forming an airgel layer from a mist-like sol.
  2. 　前記ゾルが、加水分解性の官能基又は縮合性の官能基を有するケイ素化合物、及び、前記加水分解性の官能基を有するケイ素化合物の加水分解生成物からなる群より選択される少なくとも一種を含有する、請求項１に記載の構造体の製造方法。 The sol contains at least one selected from the group consisting of a silicon compound having a hydrolyzable functional group or a condensable functional group, and a hydrolysis product of the silicon compound having the hydrolyzable functional group. The method for manufacturing the structure according to claim 1.
  3. 　前記ゾルがシリカ粒子を更に含有する、請求項２に記載の構造体の製造方法。 The method for producing a structure according to claim 2, wherein the sol further contains silica particles.
  4. 　前記シリカ粒子の平均一次粒子径が１～５００ｎｍである、請求項３に記載の構造体の製造方法。 The method for producing a structure according to claim 3, wherein the silica particles have an average primary particle diameter of 1 to 500 nm.
  5. 　前記ゾルの液滴の直径が０．１～１０００μｍである、請求項１～４のいずれか一項に記載の構造体の製造方法。 The method for producing a structure according to any one of claims 1 to 4, wherein a diameter of the sol droplet is 0.1 to 1000 µm.
  6. 　前記ゾルが、沸点２００℃未満の溶媒を含有する、請求項１～５のいずれか一項に記載の構造体の製造方法。 The method for producing a structure according to any one of claims 1 to 5, wherein the sol contains a solvent having a boiling point of less than 200 ° C.
  7. 　前記構造体が、本体部と、前記本体部の表面の少なくとも一部を被覆する被覆層とを備え、前記被覆層が中間層となるように、少なくとも前記被覆層上にエアロゲル層が形成される、請求項１～６のいずれか一項に記載の構造体の製造方法。 The structure includes a main body portion and a coating layer that covers at least a part of the surface of the main body portion, and an airgel layer is formed on at least the coating layer so that the coating layer serves as an intermediate layer. The method for producing a structure according to any one of claims 1 to 6.
  8. 　前記被覆層が充填材を含有する、請求項７に記載の構造体の製造方法。 The method for manufacturing a structure according to claim 7, wherein the coating layer contains a filler.
  9. 　前記充填材が無機充填材である、請求項８に記載の構造体の製造方法。 The method for manufacturing a structure according to claim 8, wherein the filler is an inorganic filler.
  10. 　前記充填材の含有量が、前記被覆層の全体積に対して、０．１～７０体積％である、請求項８又は９に記載の構造体の製造方法。 The method for manufacturing a structure according to claim 8 or 9, wherein the content of the filler is 0.1 to 70% by volume with respect to the total volume of the coating layer.
PCT/JP2017/003739 2017-02-02 2017-02-02 Method for producing structure WO2018142530A1 (en)

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JP2007193051A (en) * 2006-01-18 2007-08-02 Pentax Corp Method for forming optical film and optical component having optical film
JP2009258711A (en) * 2008-03-25 2009-11-05 Hoya Corp Method for forming antireflective film and optical film
WO2016121757A1 (en) * 2015-01-27 2016-08-04 日立化成株式会社 Aerogel laminate and thermal insulation material
WO2017038648A1 (en) * 2015-08-28 2017-03-09 日立化成株式会社 Insulated object manufacturing method

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006227596A (en) * 2005-01-21 2006-08-31 Pentax Corp Optical element having antireflection film and manufacturing method thereof
JP2007193051A (en) * 2006-01-18 2007-08-02 Pentax Corp Method for forming optical film and optical component having optical film
JP2009258711A (en) * 2008-03-25 2009-11-05 Hoya Corp Method for forming antireflective film and optical film
WO2016121757A1 (en) * 2015-01-27 2016-08-04 日立化成株式会社 Aerogel laminate and thermal insulation material
WO2017038648A1 (en) * 2015-08-28 2017-03-09 日立化成株式会社 Insulated object manufacturing method

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