Thermal insulation fabric

Abstract

A heat-insulating cloth (1) includes a base material (10) having a cloth, and a heat-insulating portion (11) having aerogel particles and being discontinuously arranged on a surface of the base material (10) in a planar direction. The height of the heat-insulating portion (11) is 0.1 mm or more and 1 mm or less. In a case where the area of the surface of the base material (10) is 100%, the total area of the surface of the base material (10) covered with the heat-insulating portion (11) is 8% or more and 65% or less.

Description

Technical Field

[0001] This disclosure relates to thermally insulating fabrics using aerogel. Background Technology

[0002] Various thermal insulation materials are being developed to effectively utilize the high thermal insulation properties of aerogels. For example, Patent Documents 1 and 2 describe a thermal insulation material manufactured by applying a coating, which is formed by dispersing silica aerogel into an adhesive liquid, to the entire surface of a substrate and then drying it.

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2020-29528; Patent Document 2: International Publication No. 2022 / 259930; Patent document 3: Japanese Patent No. 6584046; Patent document 4: Utility Model Registration No. 3233325. Summary of the Invention

[0004] Insulation materials using silica aerogel are used not only in the automotive, residential, and home appliance industries, but also, for example, in the clothing industry for highly insulating garments, as described in Patent Documents 3 and 4. For clothing fabrics, breathability is desirable to prevent stuffiness, and softness is desirable to reduce stiffness during wear. However, since silica aerogels and adhesives lack breathability, forming a silica aerogel layer on the entire surface of a fabric or other substrate improves insulation but reduces breathability. Furthermore, because silica aerogels are rigid inorganic particles, their softness is also reduced.

[0005] In this regard, Patent Document 3 describes a laminated fabric for highly insulating clothing containing a mixture of aerogel and synthetic resin foam. In paragraph

[0026] , it states that if the mixture of aerogel and synthetic resin foam is arranged in a spot-like or dot-like pattern, breathability is improved. However, the property of allowing water vapor to pass through, i.e., moisture permeability, is different from the property of allowing air to pass through, i.e., air permeability. Furthermore, Patent Document 3 does not, based on moisture permeability, conduct research on the size, arrangement, etc., of the mixture from the viewpoint of softness and thermal insulation.

[0006] This disclosure was made in view of the following situation: the problem is to provide a thermally insulating fabric with excellent thermal insulation, moisture permeability, and softness.

[0007] means for solving problems (1) In order to solve the above problems, the thermal insulation fabric of the present disclosure is characterized in that the thermal insulation fabric has: a substrate having a cloth; and a thermal insulation portion having aerogel particles and being disposed discontinuously on the surface of the substrate in the surface direction, the height of the thermal insulation portion being 0.1 mm or more and 1 mm or less, and when the surface area of ​​the substrate is 100%, the total area of ​​the surface of the substrate covered by the thermal insulation portion is 8% or more and 65% or less.

[0008] The thermal insulation fabric disclosed herein has thermal insulation portions disposed discontinuously on the surface of a substrate along the surface direction. Instead of continuously forming (so-called covering) the entire surface of the substrate with thermal insulation portions containing aerogel particles lacking moisture permeability, the thermal insulation portions containing aerogel particles lacking moisture permeability are formed discontinuously in the surface direction with gaps (spaces), thereby allowing water vapor to pass through easily and imparting moisture permeability to the thermal insulation fabric. Furthermore, because the thermal insulation portions containing relatively hard aerogel particles are discontinuous, the softness of the thermal insulation fabric is improved. In addition, the inventors' repeated research has yielded the insight that a larger height of the thermal insulation portions results in a greater improvement in thermal insulation performance. Based on this insight, in the thermal insulation fabric of this disclosure, the height of the thermal insulation portions is determined to be 0.1 mm or more and 1 mm or less. Moreover, by ensuring that the total area of ​​the substrate surface covered by the thermal insulation portions is 8% or more and 65% or less, the desired thermal insulation performance is maintained, while moisture permeability and softness are simultaneously achieved. Thus, the thermal insulation fabric of this disclosure exhibits excellent thermal insulation, moisture permeability, and softness. Furthermore, according to the thermal insulation fabric of this disclosure, compared to the case where the thermal insulation portion is formed on the entire surface of the substrate, the amount of aerogel used can be reduced, thereby achieving lower cost and lighter weight for the thermal insulation fabric.

[0009] (2) In the above configuration, it can also be configured as follows: the heat insulation portion has a plurality of protrusions arranged in a dotted pattern on the surface of the substrate. If the heat insulation portion is arranged in a dotted pattern as protrusions, in other words, if it is distributed in an island-like pattern, it is easy to arrange the heat insulation portion evenly along the surface direction of the substrate, so that the distance between adjacent protrusions is relatively large. As a result, the moisture permeability and softness are improved.

[0010] (3) In the configuration described in (2) above, it may also be configured such that the ratio of the height of the protrusion to the maximum distance from the bottom surface, i.e., the aspect ratio, is 0.01 or more and 0.23 or less. As mentioned above, according to the inventor's view, from the viewpoint of improving heat insulation, it is preferable that the height of the heat insulation portion is large. However, when the heat insulation portion is arranged in a dotted pattern in the form of protrusions, since the protrusions are individually fixed to the substrate, if the height of the protrusions becomes large, they become more prone to falling off due to washing, etc. According to this configuration, by setting the aspect ratio of the protrusions to 0.01 or more and 0.23 or less, the desired durability (washability) for washing can be achieved.

[0011] (4) In the configuration of (2) or (3) above, the protrusion may also be hemispherical. By making the protrusion a rounded shape without corners, the impact during washing and other processes is reduced, and the protrusion becomes less likely to fall off. Therefore, according to this configuration, the washability of the heat-insulating fabric is improved.

[0012] (5) In any of the above configurations, the fabric may also be configured as follows: the fabric contains polyester fibers. Fabrics using polyester fibers have advantages such as excellent quick-drying properties, high durability, and resistance to wrinkling. In addition, hydroxyl groups are present in polyester fibers. Even assuming that the hydroxyl groups are reduced due to dyeing processes, etc., they can be easily imparted by performing other surface treatments such as waterproofing. Therefore, if polyester fibers are used, the adhesion of the insulation part can be improved by chemically bonding the hydroxyl groups with the constituent materials of the insulation part.

[0013] (6) In any of the above configurations, the fabric may also be waterproof. According to this configuration, since the fabric constituting the substrate has water-repellent properties, the washability is improved. In addition, when a liquid heat-insulating composition or the like is applied to the substrate to form a heat-insulating portion, the penetration of the heat-insulating composition can be suppressed. Furthermore, when hydroxyl groups are imparted to the fabric through a waterproofing process, the adhesion of the heat-insulating portion can be improved by chemically bonding the hydroxyl groups with the constituent materials of the heat-insulating portion.

[0014] (7) In any of the above configurations, the insulation portion may also be formed by a composition comprising the aerogel particles, polyurethane resin adhesive, carbodiimide compound, and isocyanate compound. The carbodiimide compound functions as a crosslinking agent for the polyurethane resin adhesive. The carbodiimide compound reacts with the polyurethane resin to form urea bonds. As a result, the strength of the insulation portion increases by increasing the number of crosslinking points and making the three-dimensional mesh structure denser. Consequently, the holding power of the aerogel particles increases, and the aerogel particles are less likely to fall off (shed dust) even after washing. The isocyanate compound mainly improves the adhesion between the insulation portion and the substrate. The isocyanate compound chemically bonds with hydroxyl groups and other components on the surface of the substrate, thereby improving the adhesion of the insulation portion relative to the substrate. As a result, the insulation portion is less likely to peel off even after washing. Thus, according to this configuration, the washability of the insulation fabric is improved.

[0015] (8) In any of the above configurations, it may also be configured as follows: a protective layer is further laminated on the outside of the heat insulation portion. According to this configuration, by positioning the heat insulation portion between the substrate and the protective layer, the heat insulation portion is less likely to detach due to friction during use, impact during washing, etc. As a result, durability and washability are improved. In addition, since the space (air layer) existing between the heat insulation portions is sealed by the substrate and the protective layer, the heat insulation effect based on the air layer is also achieved on the basis of the heat insulation effect based on the heat insulation portion, thus improving the heat insulation performance.

[0016] (9) In any of the above configurations, the aerogel particles may also be configured as follows: the aerogel particles are silica aerogel particles. The size of the skeleton of the silica aerogel particles is well balanced with the size of the pores, resulting in excellent thermal insulation. Therefore, this configuration is suitable for improving thermal insulation. In addition, if hydrophobic sites are present on at least one surface of the silica aerogel particles, both on the outer surface and the inner surface (pore-forming surface), water penetration is suppressed, which is suitable for improving washability.

[0017] Invention Effects The heat-insulating fabric disclosed herein has excellent heat insulation, moisture permeability, and softness. Attached Figure Description

[0018] Figure 1 This is a top view of one embodiment of the thermal insulation fabric disclosed herein.

[0019] Figure 2 yes Figure 1 Sectional view along direction II-II. Detailed Implementation

[0020] The following describes embodiments of the thermal insulation fabric of this disclosure. Furthermore, the embodiments are not limited to the following methods and can be implemented through various modifications and alterations that can be made by those skilled in the art. The numerical ranges using "~" in this specification indicate the range encompassed by the values ​​described before and after the "~", which are respectively taken as the minimum and maximum values. Within the numerical ranges described in stages in this specification, the individually described upper and lower limits can be arbitrarily combined. Additionally, the upper and lower limits of the numerical ranges can be replaced with the values ​​shown in the embodiments.

[0021] <Insulating Fabrics> First, an embodiment of the thermal insulation fabric of this disclosure will be described using the accompanying drawings. Figure 1 This is a top view showing one embodiment of the thermal insulation fabric of this disclosure. Figure 2 express Figure 1 Sectional view along direction II-II. (See example) Figure 1 , Figure 2As shown, the heat-insulating fabric 1 includes a substrate 10 and a heat-insulating part 11. The substrate 10 is a 100% polyester fiber fabric that has been waterproofed using a hydrocarbon-based waterproofing agent. The thickness of the substrate 10 is 0.12 mm.

[0022] The heat insulation portion 11 is composed of a plurality of protrusions 110. The protrusions 110 are spaced apart at intervals P on the upper surface of the substrate 10 and arranged in a dotted pattern. All protrusions 110 are identical in composition, shape, and size. The bottom surface of each protrusion 110 is a circular hemispherical shape. The height T of each protrusion 110 is 0.18 mm, the diameter L of the bottom surface is 2.5 mm, and the aspect ratio (T / L) is 0.07. With the surface area of ​​the substrate 10 being 100%, the total area of ​​the substrate 10 covered by the protrusions 110 (heat insulation portion 11) is 22.7%. The protrusions 110 are formed from a heat insulation composition comprising silica aerogel particles, polyurethane resin binder, carbodiimide compound, isocyanate compound, and dispersant.

[0023] Next, the various elements constituting the thermal insulation fabric of this disclosure will be described. The thermal insulation fabric of this disclosure has a substrate and thermal insulation portions disposed discontinuously on the surface of the substrate along the surface direction.

[0024] [Substrate] The substrate is a fabric. The fabric can be any of woven, woven, or nonwoven materials. From the viewpoint of improving strength, woven or woven fabrics are preferred. The fabric can be a single sheet or multiple sheets layered together. There are no particular limitations on the material of the fabric; it can be appropriately selected according to the intended use of the insulating fabric disclosed herein. Examples include chemical fibers such as polyester, nylon, acrylic, polyvinyl chloride, and polyurethane, as well as natural fibers such as cotton, linen, and wool. The fiber can be a single type or a mixture of multiple types. Fabrics using polyester fibers have advantages such as excellent quick-drying properties, high durability, and resistance to wrinkling. Furthermore, if fibers containing hydroxyl groups, such as polyester, cotton, acrylic, or linen, are used, the hydroxyl groups of the fabric may chemically bond with the constituent materials of the insulating portion, thereby increasing the adhesion of the insulating portion.

[0025] From the viewpoint of improving washability and inhibiting the penetration of liquid insulation composition during insulation formation, it is preferable that at least the fabric in contact with the insulation is waterproof. The waterproof fabric can be any of the following: fabric made using fibers that are inherently waterproof, fabric made using fibers that have undergone waterproofing treatment, or fabric that has undergone waterproofing treatment. When waterproofing is applied to fibers or fabric, a waterproofing agent can be applied to the object being treated or the object can be impregnated with the waterproofing agent. When waterproofing is applied to fabric, the waterproofing agent can impregnate part or all of the fabric, or form a waterproof layer on the surface of the fabric. In the latter case, the insulation can be disposed on the surface of the waterproof layer. There is no particular limitation on the type of waterproofing agent; it can be appropriately selected from hydrocarbon-based waterproofing agents, polyurethane-based waterproofing agents, silicone-based waterproofing agents, etc. When the waterproofing agent has hydroxyl groups, there is a possibility that it chemically bonds with the constituent materials of the insulation, thereby improving the adhesion of the insulation.

[0026] The substrate can be composed solely of fabric (whether or not it is waterproof), or of fabric with a waterproof layer disposed on its surface, or it can be a laminate containing other layers such as resin or elastomer layered within the fabric. The surface of the substrate for use with the insulation section is preferably fabric or a waterproof layer disposed on its surface. The thickness of the substrate can be appropriately determined according to the application. For example, where thinness and lightweight are required, a thickness of 0.1 mm or more and 1 mm or less is preferred.

[0027] [Insulation Section] The insulation section contains aerogel particles. These aerogel particles are composed of a framework formed by multiple primary particles linked together, with fine pores between the particles. There are no particular limitations on the manufacturing method of the aerogel; it can be manufactured by drying under normal pressure or by drying under supercritical conditions. Sometimes, depending on the drying method used in manufacturing the aerogel, it is called "dry gel" when dried under normal pressure and "aerogel" when dried under supercritical conditions. In this specification, both (regardless of the drying method) are collectively referred to as "aerogel."

[0028] There are no particular limitations on the type of aerogel particles. Examples of primary particles forming the aerogel framework include inorganic particles such as silica, alumina, zirconium oxide, and titanium dioxide. Among these, silica aerogel particles, with silica as the primary particle, are preferred due to their excellent chemical stability. Silica aerogel particles are white and reflect infrared radiation. Therefore, using silica aerogel particles can impart a heat-insulating effect to the insulating part. Furthermore, if hydrophobic sites exist on at least the outer surface and the inner surface (pore-forming surface) of the silica aerogel particles, water penetration is inhibited, which improves washability.

[0029] The shape of the aerogel particles can be spherical, irregularly shaped, etc., without particular limitation. When the aerogel particles are spherical or chamfered (rounded by the removal of corners), in addition to becoming easier to fix with adhesives and less prone to detachment, it is easier to reduce the gaps between particles and increase the filling volume. Furthermore, the term "spherical" in this specification is not limited to a perfect sphere, but includes the concept of a shape close to a sphere (almost spherical). For example, if the aerogel powder is pulverized, chamfered particles can be easily obtained. Considering the ease of application of the composition for forming the heat insulation part and the suppression of aerogel particle detachment, it is preferable that the aerogel particles are relatively small and uniform in size. For example, the 90% particle size (D) in the volume-based particle size distribution determined by laser diffraction scattering method is preferred. 90 Preferably, the micrometer size is 200 μm or less, and more preferably 150 μm or less.

[0030] The heat insulation portion is discontinuously arranged on the surface of the substrate along the surface direction. There are no particular limitations on the shape of the heat insulation portion; for example, it can be multiple protrusions scattered in a dotted or island-like pattern, multiple protruding strips arranged separately, or protrusions intersecting in a grid-like arrangement. When the heat insulation portion is composed of multiple elements such as protrusions and convex shapes, the shape and size of each element can be the same or different. Multiple elements can be arranged equally along the surface direction, or the distance (spacing) between adjacent elements can be varied to create a density distribution along the surface direction.

[0031] The height of the heat insulation portion is 0.1 mm or more and 1 mm or less. From the viewpoint of improving heat insulation performance, it is preferable to be 0.15 mm or more, and more preferably 0.20 mm or more. When thinness and flexibility are required, it is preferable to be 0.85 mm or less, and more preferably 0.50 mm or less.

[0032] When the insulation section has raised strips, the extension shape of the raised strips can be straight, curved, bent, etc. The cross-sectional shape of the raised strip in the height direction can be rectangular, trapezoidal or other quadrilaterals, triangles, semicircles, etc. From the viewpoint of preventing the raised strips from falling off, it is preferable that the top of the raised strip is curved, such as having an arched cross-sectional shape.

[0033] When the heat insulation part has a protrusion, the shape of the protrusion can be hemispherical, cylindrical, conical, frustum conical, prism-shaped, pyramidal, frustum pyramidal, etc. From the viewpoint of preventing the protrusion from falling off, it is preferable that the top of the protrusion is curved. Furthermore, in this specification, "hemispherical" refers not only to a hemisphere that is half of a sphere, but also to a shape that is close to a hemisphere. That is, "hemispherical" also includes shapes with curved surfaces that are close to a hemisphere, such as dome-shaped shapes.

[0034] From the viewpoint of thermal insulation, the aspect ratio calculated by dividing the height of the protrusion by the maximum distance from the bottom surface is preferably 0.01 or higher. More preferably, it is 0.02 or higher. Furthermore, from the viewpoint of improving washability by suppressing the shedding of the protrusion, it is preferably 0.23 or lower. More preferably, it is 0.20 or lower.

[0035] When the surface area of ​​the substrate is 100%, the total area of ​​the substrate surface covered by the heat-insulating portion (coverage area of ​​the substrate surface based on the heat-insulating portion) is 8% or more and 65% or less. Even if the area of ​​the heat-insulating portion is relatively small, the heat insulation performance is not easily reduced because an air layer exists in the gaps between the heat-insulating portions. From the viewpoint of improving heat insulation performance, it is preferable to be 10% or more, and more preferably 20% or more. From the viewpoint of improving moisture permeability and flexibility, it is preferable to be 60% or less, and more preferably 50% or less.

[0036] [Other elements] The thermal insulation fabric disclosed herein only needs to have a substrate and a thermal insulation portion, and there are no particular limitations on other components. For example, the thermal insulation fabric of this disclosure may also have a protective layer laminated on the outside of the thermal insulation portion (opposite to the substrate in the thickness direction). By covering the thermal insulation portion with a protective layer, the thermal insulation portion is less likely to detach due to friction during use or impact during washing. As a result, durability and washability are improved. In addition, since the space (air layer) existing between the thermal insulation portions is sealed by the substrate and the protective layer, the thermal insulation effect based on the air layer is achieved on top of the thermal insulation effect based on the thermal insulation portion, thus improving the thermal insulation performance.

[0037] The protective layer can take the form of fabric, woven fabric, non-woven fabric, film, sheet, etc., without particular limitation. Examples include fabrics, woven fabrics, non-woven fabrics, leather sheets, and resin films made from chemical fibers, natural fibers, etc. Among these, polyester fiber fabrics, non-woven fabrics, polyester films, and polyurethane sheets are preferred due to their excellent durability, moisture permeability, and softness. The protective layer can be a single layer or a laminate composed of two or more layers of the same or different materials. Examples of laminates include aluminum vapor-deposited films.

[0038] <Manufacturing Method of Thermal Insulation Fabric> The thermal insulation fabric disclosed herein can be manufactured by applying a thermal insulation composition containing aerogel particles to the surface of a substrate in a predetermined form and then drying it. There are no particular limitations on the components other than the aerogel particles in the thermal insulation composition; however, considering durability and other factors, it is preferable to include a polyurethane resin binder, a carbodiimide compound, and an isocyanate compound.

[0039] As a polyurethane resin adhesive, it is preferable to use an adhesive that uses water (including pure water, tap water, etc.) as a solvent (water-based adhesive). Among water-based adhesives, there are water-soluble adhesives and emulsion-like adhesives, but based on the reason that the composition used in the heat insulation part does not easily produce stickiness after curing, emulsion-like adhesives (water-based emulsion adhesives) are preferred.

[0040] There are no particular limitations on carbodiimide compounds, as long as they contain a carbodiimide group in their molecule. Examples include dicyclohexylcarbodiimide, diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, dicyclohexylmethanecarbodiimide, aqueous dicyclohexylmethanecarbodiimide, and aqueous tetramethylphenyldimethylcarbodiimide. Considering compatibility with waterborne resins (polyurethane resin adhesives), water-soluble or water-dispersible carbodiimide compounds with a terminal hydroxyl group are preferred.

[0041] From the viewpoint of increasing the crosslinking density of the adhesive to enhance the holding power of aerogel particles, the content of the carbodiimide compound is preferably 1 part by mass or more relative to 100 parts by mass of the polyurethane resin adhesive. More preferably, it is 2 parts by mass or more. On the other hand, from the viewpoint of thermal insulation, it is preferable to have a low content of compounds that do not contribute to improving thermal insulation. Therefore, the content of the carbodiimide compound is preferably 10 parts by mass or less relative to 100 parts by mass of the polyurethane resin adhesive. More preferably, it is 8 parts by mass or less.

[0042] Examples of isocyanate compounds include aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and mixtures thereof. Specifically, examples include 4,4'-dicyclohexylmethane diisocyanate (HMDI), tetramethylphenyl dimethylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI), 2,4,6-triisopropylphenyl diisocyanate (TIDI), 4,4'-diphenylmethane diisocyanate (MDI), and toluene diisocyanate (TDI).

[0043] From the viewpoint of improving the adhesion of the heat insulation portion to the substrate, the content of the isocyanate compound is preferably 3 parts by mass or more relative to 100 parts by mass of the polyurethane resin adhesive. More preferably, it is 5 parts by mass or more. On the other hand, from the viewpoint of heat insulation, it is preferable to have a low content of compounds that do not contribute to improving heat insulation. Therefore, the content of the isocyanate compound is preferably 15 parts by mass or less relative to 100 parts by mass of the polyurethane resin adhesive. More preferably, it is 10 parts by mass or less.

[0044] In addition to aerogel particles, polyurethane resin binders, carbodiimide compounds, and isocyanate compounds, the composition for the thermal insulation section may also include coupling agents, dispersants, flame retardants, etc. For example, when using silica aerogel particles as the aerogel particles, by incorporating a silane coupling agent, the holding power of the aerogel particles can be further increased because the silica aerogel particles and the polymer backbone of the polyurethane resin are bonded by the silane coupling agent. To achieve this effect, the content of the coupling agent is preferably 0.1 parts by mass or more relative to 100 parts by mass of the polyurethane resin binder. On the other hand, from the viewpoint of thermal insulation, the content of the coupling agent is preferably 3 parts by mass or less.

[0045] For example, silica aerogel particles have a low specific gravity and easily float on water. Furthermore, if they have hydrophobic sites on their surface or inside, they do not readily mix with water. Therefore, when preparing compositions for thermal insulation components using water as a solvent, a dispersant is preferably added to improve the dispersibility of the silica aerogel particles. Examples of dispersants include surfactants and thickeners.

[0046] Surfactants can be categorized into ionic surfactants (cationic surfactants, anionic surfactants, and amphoteric surfactants) and nonionic surfactants. Examples of ionic surfactants include sodium carboxymethyl cellulose (CMC-Na), polycarboxylic acid amine salts, polycarboxylic acid ammonium salts, sodium polycarboxylic acid, and TEMPO oxidized cellulose nanofibers (CNF-Na). Examples of nonionic surfactants include special polycarboxylic acid amine salts, polyethylene oxide (PEO), and polyvinyl alcohol (PVA). Furthermore, it is preferable to use both nonionic and ionic surfactants in combination.

[0047] When combined with a flame retardant, the insulation material can be made flame-retardant. Well-known flame retardants such as halogen-based, phosphorus-based, and metal hydroxide-based flame retardants can be used. Considering environmental impact, phosphorus-based flame retardants are preferred. Examples of phosphorus-based flame retardants include ammonium polyphosphate, red phosphorus, and phosphate esters. Among these, considering that the flame retardant is less likely to leak out even when in contact with moisture during use, phosphorus-based flame retardants coated with water-insoluble phosphorus-based flame retardants or water-resistant resins are preferred; for example, ammonium polyphosphate or resin-coated ammonium polyphosphate are preferred.

[0048] The insulation component can be prepared by stirring, for example, by adding components as needed, excluding aerogel powder, polyurethane resin binder, carbodiimide compound, and isocyanate compound. If the polyurethane resin binder is anhydrous, water can be added appropriately. If the aerogel is silica aerogel, considering its dispersibility, it is preferable to add silica aerogel powder after adding a dispersant to the polyurethane resin binder or a liquid formed by adding the polyurethane resin binder to water. Stirring can be done with blade stirring, but shear force or ultrasound can also be applied actively. Rotational stirring devices or media-type stirring devices can also be used.

[0049] The composition for the heat insulation part can be applied to the substrate using coating machines such as screen printing, rotary screen printing, doctor blade coating machine, bar coating machine, die coating machine, comma coating machine (registered trademark), roller coating machine, brush coating, or sprayer. After application, the coating film can be dried and cured at a temperature of 80~150℃ for about 5~20 minutes.

[0050] Example The present disclosure will now be described in more detail by way of examples.

[0051] <Sample Manufacturing> [Examples 1-4] First, the composition for the heat insulation component, as shown in Table 1 (parts by mass) described later, was prepared as follows: A polyurethane resin emulsion (PERMARIN UA-368, manufactured by Sanyo Chemical Industries, Ltd., 50% by mass of solids), a nonionic surfactant (a special polycarboxylic acid amine salt, NOPCOSPERSE 6100, manufactured by SANNOPCO Co., Ltd.), and sodium carboxymethyl cellulose (CMC-Na, CELLOGEN BSH-12, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.) were added to water and stirred. Silica aerogel powder (Aerogel Particles P200, manufactured by Cabot Corporation, pulverized product, 90% particle size (D)) was then added. 90 The mixture was stirred with 150 μm, carbodiimide compounds, and isocyanate compounds.

[0052] Next, a substrate was manufactured by impregnating 100% polyester fiber fabric (0.12 mm thick) with a hydrocarbon-based waterproofing agent (NEOSEED NR-8800 manufactured by Nichika Chemical Co., Ltd.) and then heat-treating it. The substrate became waterproof through the waterproofing process based on the hydrocarbon-based waterproofing agent. Then, the prepared thermal insulation composition was screen-printed onto the surface of the substrate at predetermined intervals using a dotted pattern. This produced samples of the thermal insulation fabrics of Examples 1 to 4, in which the cured product of the thermal insulation composition was used to create raised portions dotted on the surface of the substrate. In each sample, all raised portions were hemispherical with a circular base. The base diameter (base area) and height of the raised portions varied for each sample. All raised portions in a single sample were the same size. Table 1, described later, shows the height, bottom diameter, aspect ratio, spacing (distance from the center-to-center distance of adjacent protrusions to the bottom radius of the two protrusions (= the bottom diameter of one protrusion)) of the protrusions in each sample, and the coverage area of ​​the substrate surface based on the insulation.

[0053] [Comparative Example 1] The heat-insulating composition used in the manufacture of samples of Examples 1 to 4 was applied to the surface of a substrate with a coating thickness of 0.3 mm using a doctor blade. The substrate was then placed in a hot air oven and maintained at 80°C for 1 hour, followed by further drying at 100°C until no further loss of mass was observed. This produced a sample of the heat-insulating fabric of Comparative Example 1, in which the cured product of the heat-insulating composition was layered on the surface of a substrate. The coverage area of ​​the substrate surface based on the formed aerogel layer was 100%.

[0054] [Comparative Examples 2-4] Except for setting the height of the protrusions to 0.25 mm and appropriately changing the bottom diameter and spacing, samples of the thermal insulation fabrics of Comparative Examples 2 to 4 were manufactured in the same manner as in Examples 1 to 4. The height of the protrusions, bottom diameter, aspect ratio, spacing, and coverage area based on the thermal insulation portion are shown in Table 1 described later.

[0055] [Reference Example 1] Except for the point where the height of the protrusion is changed to 0.85 mm to achieve an aspect ratio of 0.24, a sample of the thermal insulation fabric of Reference Example 1 was manufactured in the same manner as in Example 2. The height of the protrusion, the bottom diameter, the aspect ratio, the spacing, and the coverage area based on the thermal insulation portion are shown in Table 1 described later.

[0056] <Evaluation Methods> [Washability] The manufactured samples were cut into rectangular shapes with a length of 280 mm and a width of 210 mm, and washing tests were conducted based on JIS L1930:2024 "Household Washing Test Methods for Fiber Products". As part of the washing test, ten washes were performed using a C-shaped standard washing machine, following the washing method "C4M" in Appendix E of the JIS, "Specification for Washing Methods of C-shaped Standard Washing Machines (Pulsator Type)". The drying method was set to Method A (hanging to dry).

[0057] The washing method “C4M” specified in Appendix E is as follows.

[0058] Water temperature: 40±3℃.

[0059] Water volume displayed during washing and rinsing processes: 40L.

[0060] Washing process: 6 minutes for washing, 3 minutes for dehydration.

[0061] First rinsing process: rinsing time 2 minutes, dehydration time 3 minutes.

[0062] Second rinsing process: rinsing time 2 minutes, dehydration time 3 minutes.

[0063] Then, the mass of the samples before and after the test was measured, and the washability was evaluated based on the mass residue rate calculated by the following formula (I). In the evaluation of washability, if the mass residue rate is above 90%, it is evaluated as qualified; if it is less than 90%, it is evaluated as unqualified.

[0064] Residual mass percentage (%) = (Sample mass after washing / Sample mass before washing) × 100 (I) [Thermal insulation (heat preservation)] The prepared samples were cut into squares measuring 300mm in length and 300mm in width. Thermal insulation tests were conducted according to Method 8.27.1 A (Constant Temperature Method) of JIS L1096:2010 "Test Methods for Fabrics and Woven Fabrics". An ASTM-type thermal insulation testing machine conforming to ASTM D 1518-85 was used. The temperature inside the testing machine was set to 20°C and the relative humidity (RH) to 65%. The thermal insulation rate of the sample was calculated using the following formula (II) based on the energy required by the constant temperature heating element in the testing machine to maintain the temperature. The size of the constant temperature heating element was set to 250mm × 250mm, the temperature to 36 ± 0.5°C, and the test time to 120 minutes from when the temperature of the constant temperature heating element became constant. The samples were arranged with the substrate side facing upwards (opposite to the constant temperature heating element). A higher thermal insulation rate indicates higher thermal insulation performance. In the evaluation of thermal insulation, if the insulation rate is above 12%, it is considered qualified; if it is less than 12%, it is considered unqualified.

[0065] Insulation rate (%) = (Ho - Hc) / Ho × 100 (II) [Ho: Heat loss from the isothermal heating element; Hc: Heat loss when the sample is wrapped around the isothermal heating element] [Moisture permeability] The prepared sample was cut into a circular shape with a diameter of 70 mm, and a moisture permeability test was performed based on "7.1.2 A-1 method (calcium chloride method)" of JIS L1099:2021 "Test method for moisture permeability of fiber products". The sample was arranged with the insulating side facing upward (the side opposite to the desiccant). Then, the moisture permeability of the sample was calculated using Equation (1) of this method. The higher the moisture permeability, the higher the moisture permeability. In the evaluation of moisture permeability, if the moisture permeability is 300 g / m 2 If the h is above, it is considered qualified; if it is less than 300g / m 2 If h, then the evaluation is unqualified.

[0066] [Softness] The prepared samples were cut into strips 20 mm wide and 150 mm long. A softness test was conducted based on JIS L1096:2010 "Test Methods for Fabrics and Woven Fabrics" under "8.21 Stiffness and Softness" and "8.21.1 A Method (45° Cantilever Method)". The samples were arranged with the insulating side facing down. In this test, the smaller the length of movement of the sample, the higher the softness. In the evaluation of softness, a movement length of less than 60 mm was considered acceptable, while a movement length greater than 60 mm was considered unacceptable.

[0067] <Evaluation Results> Table 1 summarizes the composition of the insulation composition used in the manufacture of the samples, the structure of the substrate, the specifications of the insulation, and the evaluation results of the samples.

[0068] [Table 1]

[0069] As shown in Table 1, the samples of Examples 1 to 4 exhibited good moisture permeability, softness, heat insulation, and washability. Compared to the sample of Example 1, the sample of Example 2, with its larger protrusion height, showed improved heat insulation. Conversely, the sample of Comparative Example 1, where the heat insulation portion was formed over the entire surface of the substrate instead of being dotted, showed good heat insulation, but reduced moisture permeability and softness. Furthermore, the sample of Comparative Example 2, based on a heat insulation portion coverage area greater than 65%, also exhibited insufficient moisture permeability and softness. Conversely, the samples of Comparative Examples 3 and 4, based on a heat insulation portion coverage area less than 8%, showed good moisture permeability and softness, but reduced heat insulation. Additionally, in the samples of Reference Example 1 and Comparative Example 3, the aspect ratio of the protrusion was greater than 0.23, resulting in good moisture permeability and softness, but the desired washability was not achieved.

[0070] Industrial applicability The thermally insulating fabric disclosed herein can be used in a wide variety of items in the fields of clothing, outdoor activities, and residential applications. For example, it is suitable for clothing, hats, shoe insoles, cold-weather gear such as gloves, bedding, tents, floor mats, curtains, wall materials, etc.

[0071] Explanation of reference numerals in the attached figures: 1: Thermal insulation fabric; 10: Substrate; 11: Thermal insulation part; 110: Protrusion.

Claims

1. A heat-insulating fabric, wherein, The thermal insulation fabric comprises: a substrate having a fabric; and a thermal insulation portion having aerogel particles, which are discontinuously disposed on the surface of the substrate along the surface direction. The height of the heat insulation part is 0.1 mm or more and 1 mm or less, and when the surface area of ​​the substrate is 100%, the total area of ​​the substrate surface covered by the heat insulation part is 8% or more and 65% or less.

2. The thermal insulation fabric according to claim 1, wherein, The heat insulation portion has a plurality of protrusions arranged in a dotted pattern on the surface of the substrate.

3. The thermal insulation fabric according to claim 2, wherein, The aspect ratio of the maximum distance between the height and the bottom surface of the protrusion is greater than 0.01 and less than 0.

23.

4. The thermal insulation fabric according to claim 2 or 3, wherein, The protrusion is hemispherical.

5. The thermal insulation fabric according to any one of claims 1 to 4, wherein, The fabric contains polyester fibers.

6. The thermal insulation fabric according to any one of claims 1 to 5, wherein, The fabric is waterproof.

7. The thermal insulation fabric according to any one of claims 1 to 6, wherein, The heat insulation portion is formed from a heat insulation portion composition comprising the aforementioned aerogel particles, polyurethane resin adhesive, carbodiimide compound, and isocyanate compound.

8. The thermal insulation fabric according to any one of claims 1 to 7, wherein, The insulating fabric also has a protective layer layered on the outside of the insulating part.

9. The thermal insulation fabric according to any one of claims 1 to 8, wherein, The aerogel particles are silica aerogel particles.

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