TW201629184A - Heat insulator and method for manufacturing heat insulator - Google Patents

Abstract

The present invention provides a heat insulator that is less bulky than in the related art, has excellent processability, and can be applied to a microstructure, and also provides a manufacturing method by which such a heat insulator can be manufactured. The heat insulator according to the present invention comprises a main fiber, xerogel and/or aerogel, at least one hydrosoluble polymer selected from the group consisting of a cationic polymer and an ampholytic polymer, and/or a binder including a low-melting-point synthetic fiber, and is characterized in that the xerogel and the aerogel have a density lower than 0.5 g/cm3 and a thermal conductivity of 0.02 W/(m·K) or lower and, in terms of the gross weight, 35-210 parts by weight of the xerogel and/or aerogel are combined with 100 parts by weight of the main fiber.

Description

Insulation material and method of manufacturing the same

The present invention relates to a heat insulating material having heat insulating properties and a method of producing the heat insulating material.

In the case of refrigerating products and frozen products such as pharmaceuticals and foods, in order to prevent deterioration of quality during transportation, they are usually stored in a foamed styrene container such as a heat-insulating container or in an environment other than the conditions of refrigerating or freezing. A heat-insulating container (for example, Patent Document 1) such as a corrugated box of a heat insulating material such as urethane is transported. Such a heat-insulating container is bulky compared to the product to be stored, and thus there is a problem that the transportation cost of the product increases. Further, it is necessary to prepare a heat insulating container different from the product itself, and to store and bundle the product, which is a cause of complicated transportation procedures.

On the other hand, in most cases, it is also necessary to hold the container of the article for a long time at a high temperature. With regard to such a container, it is usually required in many cases that the external temperature does not become high at the time of use, and the user directly contacts by hand. As such a container, in order to impart heat retaining properties, a container of a fluffy material such as foamed styrene or a paper container having a laminated structure on the side wall is used. As a paper container having a laminated structure on the side wall, for example, a paper container having an air layer inside the laminated layer of the side wall as disclosed in Patent Document 2 is known. In any case, the overall bulk is larger than the inner volume, and a large space is required for transportation and storage of the container itself. [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei.

As described above, since the conventional heat insulating materials in various fields are mostly in a fluffy form, the transportation efficiency and the storage efficiency are lowered. Moreover, the raw materials used are also limited to glass wool, heat insulation boards, foaming urethanes, foamed styrenes, etc., due to their thickness and structural fragility, it is difficult to perform microfabrication and molding, and is limited to the box. An object used for a heat-insulating container or a relatively large substrate.

Therefore, an object of the present invention is to provide a heat insulating material which is denser than conventional ones and which is excellent in workability, can be applied to a fine structure, and a manufacturing method capable of producing such a heat insulating material. [Means for solving the problem]

The heat insulating material of the present invention which solves the above problems is a host fiber, a dry gel and/or an aerogel, and contains at least one water-soluble polymer selected from the group consisting of a cationic polymer and an amphoteric polymer. And a heat insulating material for a binder of a low-melting-point synthetic fiber, characterized in that the dry gel and the aerogel have a density of less than 0.5 g/cm ³ and a thermal conductivity of 0.02 W/(m·K) or less. The dry weight and the aerogel are formulated in a total weight of from 35 parts by weight to 210 parts by weight relative to 100 parts by weight of the main body fibers. The heat insulating material of the present invention having the above-described configuration is dense and has excellent workability in the same manner as a normal paper, and is otherwise provided by a certain amount of a low-density, low thermal conductivity dry gel and/or aerogel. Glue and excellent thermal insulation. Further, the heat insulating material of the present invention contains at least one water-soluble polymer selected from the group consisting of a cationic polymer and an amphoteric polymer, and/or a host fiber, a xerogel, and/or an aerogel. Low melting synthetic fiber as a binder. The inclusion of the binder has an effect of causing collapse of the particle shape of the xerogel and the aerogel in the papermaking step or the like, and it is easy to maintain the heat insulating property. In addition, the "density" here means the density measured under conditions of 25 ° C and 1 atm in the state of particles. Further, the term "dry gel" and "aerogel" as used herein means microparticles having a plurality of nanometer-sized pores and having a continuous matrix of a solid material in which air is dispersed from the pores. Further, in the present invention, the "parts by weight" means all parts by weight based on the dry weight except for water. In addition, the term "low-melting synthetic fiber" as used herein means a synthetic fiber having a melting point of 140 ° C or less at least on the surface of the fiber and having a melting point lower than the melting point when the main fiber has a melting point. Further, the heat insulating material of the present invention contains either or both of a dry gel and an aerogel, and the dry gel and the aerogel have specifications such as physical properties (density, thermal conductivity, etc.) and a blending amount. In the case where the heat insulating material of the present invention contains both a dry gel and an aerogel, both of them satisfy the specifications of the physical properties, and the total weight of the two together satisfies the regulation of the blending amount.

The binder contains the water-soluble polymer, and the water-soluble polymer is preferably at least one of a cationized starch and an amphoteric starch. By using cationized starch or amphoteric starch as a binder, the shape of the particles of the xerogel and the aerogel at the time of papermaking is more difficult to be broken, and the heat insulating property of the heat insulating material using the same can be maintained. Further, the binder contains the low-melting synthetic fiber, and the low-melting synthetic fiber is preferably a vinylon-bonded fiber. By using vinylon binder fibers as a binder, heat insulating materials can be efficiently produced.

The dry gel and the aerogel are preferably porous ceria particles obtained by dry gelation of a methyl citrate monomer by normal pressure drying or aerogelation by critical drying. The atmospheric dry gel or the critical dry gel of methyl decanoate is easily produced at a low density, and the porous shape is hard to be broken in an aqueous solution, so that the shape is easily maintained in the papermaking slurry.

It is preferred that the dry gel and the aerogel have an average particle diameter of from 2 μm to 140 μm and a specific surface area of 400 m ² /g or more. By setting the average particle diameter of the xerogel and the aerogel to 2 μm to 140 μm, the heat insulating material can be provided with sufficient heat insulating properties, and the heat insulating performance can be exhibited even in a dense heat insulating material. Further, by setting the specific surface area in which the porous ceria is activated to 400 m ² /g or more, it is possible to impart higher heat insulating properties to the heat insulating material.

The heat insulating material of the present invention is preferably in the form of a sheet having a thickness of 15 μm to 1.2 cm, a basis weight of 5 g/m ² to 480 g/m ² , and a density of 0.5 g/cm ³ to 1.5 g/cm ³ . . By setting the heat insulating material to have such a property, it is possible to have the same texture and workability as paper.

The method for producing a heat insulating material according to the present invention is characterized in that 100 parts by weight of the main fiber has a total weight of less than 0.5 g/cm ³ and a thermal conductivity of 0.02 W/(m·K) or less and 35 parts by weight to 210. The dry gel and/or aerogel of parts by weight, containing 0.3 parts by weight to 125 parts of at least one water-soluble polymer and/or low-melting synthetic fiber selected from the group consisting of cationic polymers and amphoteric polymers A part by weight of a binder is added to water to prepare a mixed slurry, and the mixed slurry is subjected to papermaking. According to the above production method, it is possible to produce a heat insulating material which is dense as in ordinary paper, has excellent workability, and has excellent heat insulating properties.

In the method for producing a heat insulating material of the present invention, it is preferred that the mixed slurry at the time of papermaking has a pH of 7 to 8. In the slurry having a pH of 7 to 8, the shape and properties of the xerogel and the aerogel are easily stabilized, and when the main fiber contains pulp, it is easy to promote fibrillation.

Further, in the method for producing a heat insulating material of the present invention, it is preferable that the binder of the mixed slurry contains the water-soluble polymer, the water-soluble polymer, and the dry gel and / or aerogel addition is mixed in a slurry in which at least the main fiber is suspended in water, and the mixed slurry is adjusted. This is because the dry gel and/or the composite of the aerogel and the fiber can be formed by winding the xerogel and/or the aerogel on the fiber, so that it is difficult to float on the water surface. (Effect of the invention)

The heat insulating material of the present invention has sufficient heat insulating properties and is excellent in compactness and processability. Moreover, the method for producing a heat insulating material of the present invention can provide a heat insulating material which is excellent in heat insulating properties, compactness, and workability.

Hereinafter, the heat insulating material of the present invention and the method for producing the heat insulating material will be exemplarily described.

1. Insulation Material The heat insulating material of the present invention is a host fiber, a dry gel and/or an aerogel, and contains at least one water-soluble polymer selected from the group consisting of a cationic polymer and an amphoteric polymer. And a heat insulating material for a binder of a low-melting-point synthetic fiber, characterized in that the dry gel and the aerogel have a density of less than 0.5 g/cm ³ and a thermal conductivity of 0.02 W/(m·K) or less. The dry weight and the aerogel are formulated in a total weight of from 35 parts by weight to 210 parts by weight relative to 100 parts by weight of the main body fibers. Hereinafter, each compounding component of the heat insulating material will be described in detail.

<Main Body Fiber> Any of synthetic fibers and natural fibers can be used as the main fiber of the heat insulating material of the present invention. In the case of using a synthetic fiber, the main fiber is not particularly limited, and for example, a synthetic fiber generally used as a raw material of a nonwoven fabric, that is, a polyester fiber, a vinylon fiber, an olefin fiber, a polyurethane fiber, or a fragrance can be used. Polyamide fibers, acrylic fibers, polylactic acid fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, polyphenylene sulfide fibers, ceramic fibers, alumina fibers, glass fibers, preferably polyester fibers, more Preferred is polyethylene terephthalate (hereinafter referred to as PET) fiber. Further, in the case of using natural fibers, the main fiber is not particularly limited, and for example, pulp may be used. The type of the pulp is not particularly limited, and any of wood pulp, non-wood pulp, and deinked pulp used as a raw material of paper can be used, and any of chemical pulp, semi-chemical pulp, and mechanical pulp can also be used. The selection of various main fibers may be appropriately changed depending on the desired flexibility, heat resistance, flame retardancy, incombustibility, flexibility, strength, and weight of the heat insulating material, and only one of the fibers may be contained in the main fiber. It can also contain a variety of fibers.

In particular, in the heat insulating material of the present embodiment which contains a large amount of a dry gel and/or an aerogel to be described later, for example, when only pulp is used as a main fiber, it has high heat insulating properties, but its strength is easy. Go low. In this case, by disposing 0.5 to 22 parts by weight of microfibrillated pulp (cellulose nanofiber) in 100 parts by weight of all the host fibers in the main fiber, the heat insulating material can be maintained. High heat insulation and the same strength and processability as paper. In a heat insulating material containing a large amount of a xerogel and/or an aerogel to be described later, in order to maintain a dry gel and an aerogel, a synthetic fiber having a fine fiber diameter is preferable.

<Dry Gel, Aerogel> The xerogel and aerogel used in the present invention are fine particles in which a plurality of nanometer-sized pores are present and have a continuous matrix of solid material in which air is dispersed from the pores, for example, 99%. Made of air, it is very light and becomes an effective insulation material. Further, as the xerogel and the aerogel, a known cerium oxide compound such as cerium oxide, methyl decanoate or cerium oxide/aluminum oxide, resorcinol-formaldehyde, cellulose, cellulose nano can be used. A porous particle such as a fiber. Regardless of the degree of porosity, it is preferred to use a material having a thermal conductivity of 0.15 W/(m·K) or less, particularly 0.1 W/(m·K) or less, and further 0.06 to 0.018 W/(m·K. )By. In particular, the methyl phthalate monomer is dry gelled by atmospheric drying or aerogelized by critical drying, and is easily produced at a low density, and a nanostructure or a hollow structure can be formed relatively easily. It is difficult to collapse in an aqueous solution, and thus can be suitably used.

The porosity of the xerogel and the aerogel is preferably from 50.0% to 99.8%, particularly preferably from 70% to 99.8%, and even more preferably from 86% to 99.8%. Further, the average particle diameter is not particularly limited, but is preferably 2 μm to 140 μm. When the particle size of the dry gel and the aerogel of the porous ceria particles exceeds 140 μm, it is necessary to make the heat insulating material thick, and it is difficult to achieve the present application which provides a dense heat insulating material having a heat insulating effect. purpose. Moreover, if it is less than 2 μm, it is difficult to obtain a sufficient heat insulating effect.

It is preferred that the xerogel and the aerogel have a specific surface area of 400 m ² /g or more, particularly 500 m ² /g to 1000 m ² /g, and further 600 m ² /g to 1000 m ² /g. . By increasing the specific surface area, the porosity can be made high. Moreover, it is also possible to reduce the overall weight of the heat insulating material.

The amount of the dry gel and/or aerogel in the heat insulating material of the present invention is preferably from 35 parts by weight to 210 parts by weight based on 100 parts by weight of the main body fibers. When the amount of the dry gel and/or the aerogel is less than 35 parts by weight based on the total weight, there is a possibility that sufficient heat insulating properties cannot be imparted to the heat insulating material. Moreover, if the amount of the dry gel and/or the aerogel is more than 210 parts by weight based on the total weight, there arises a problem that the strength of the heat insulating material is lowered, and it is difficult to obtain the desired workability of the paper, resulting from The dry gel of the heat insulating material and the aerogel fall off and fly. Further, in the case where the main fiber contains pulp and the binder described later contains at least one water-soluble polymer selected from the group consisting of a cationic polymer and an amphoteric polymer, the dry gel is considered from the same viewpoint. And the aerogel is preferably formulated in an amount of from 35 parts by weight to 75 parts by weight, particularly preferably from 35 parts by weight to 60 parts by weight, based on 100 parts by weight of the main body fibers, further preferably It is 38 parts by weight to 52 parts by weight. Further, when the main fiber contains synthetic fibers and the binder described later contains a low-melting synthetic fiber, the amount of the dry gel and/or aerogel is preferably the same as that of the above-mentioned viewpoint. The total weight of the 100 parts by weight of the main fiber is from 100 parts by weight to 210 parts by weight. Further, in the present embodiment, when a dry gel is contained and an aerogel is contained, a heat insulating material having the same performance can be obtained.

<Binder> The heat insulating material of the present invention contains a binder containing at least one water-soluble polymer and/or low-melting synthetic fiber selected from the group consisting of a cationic polymer and an amphoteric polymer. In other words, the binder contained in the heat insulating material of the present invention contains at least one water-soluble polymer selected from the group consisting of a cationic polymer and an amphoteric polymer, and/or a low-melting synthetic fiber. The water-soluble polymer can be suitably used for cationization treatment and/or amphoteric treatment of starch, polyvinyl alcohol (PVA), polyvinyl acetate, aqueous urethane or the like. In particular, at least one of the cationized starch and the amphoteric starch is difficult to generate bubbles in the aqueous solution at the time of papermaking, and can stably use paper and achieve high yield, and thus can be suitably used. The cationized starch and the amphoteric starch can be used, for example, by a known method described in JP-A-2003-64101 (Cationized Starch), JP-A-2001-19701 (Amphoteric Starch), and the like. Further, the cationic starch can be suitably used, for example, a Neotec series manufactured by Nippon Food Chemical Co., Ltd., or the like can be used. In addition, the "water-soluble polymer" means a hydrophilic colloid in addition to a soluble polymer in water.

The low-melting-point synthetic fiber has a melting point lower than the melting point if it has a melting point of at least 140 ° C or less in the surface of the fiber and when the main fiber has a melting point (for example, in the case where the main fiber contains synthetic fibers) The synthetic fiber having a melting point is not particularly limited, and examples of the low-melting synthetic fiber include vinylon-bonded fibers, olefin-bonded fibers, and polyester-bonded fibers. Particularly preferred for the low-melting synthetic fibers are vinylon-bonded fibers which are dissolved in water at 70 ° C so that the dry gel and/or aerogel can be adhered to the fibers upon drying. The vinylon-bonded fiber can be suitably used by a commercially available person, for example, VPB105-1 manufactured by Kuraray Co., Ltd., or the like can be used. Further, as the binder fiber, a core sheath fiber in which the core is a high melting point component and the sheath is a low melting point component can be used.

By using at least one water-soluble polymer selected from the group consisting of a cationic polymer and an amphoteric polymer, and/or a low-melting synthetic fiber as a binder, it is difficult to produce a papermaking step or the like due to the inclusion of the binder. The dry gel and the aerogel have a particle shape that collapses, and it is easy to maintain the heat insulation. In particular, in the case where the main fiber contains pulp and the xerogel and/or aerogel are porous ceria particles, more specifically methyl citrate particles, in a pulp slurry containing water and pulp Usually, the pulp is anionic, and the porous cerium oxide particles, particularly the methyl decanoate particles, added to the slurry exhibit anionic or amphoteric properties. The anionic pulp and the anionic or amphoteric porous ceria particles are hard to aggregate with each other, and the yield tends to be low. Here, by using a cationic polymer and/or an amphoteric polymer as a binder, aggregation of the pulp and the porous ceria particles can be promoted, and the yield can be improved. Further, the yield can be further improved by using a known aggregating agent containing chitin/polyglucamine or the like.

The binder is preferably formulated in an amount of from 0.3 part by weight to 125 parts by weight per 100 parts by weight of the main body fiber. When the amount of the binder is less than 0.3 parts by weight, it is difficult to cause breakage of the particle shape of the xerogel and the aerogel in the papermaking step or the like, and it is easy to maintain the heat insulating property. Further, when the amount of the binder is more than 125 parts by weight, the strength of the heat insulating material is lowered, and it is difficult to obtain the desired workability of the paper. Further, in the case where the main fiber contains pulp and the binder contains at least one water-soluble polymer selected from the group consisting of a cationic polymer and an amphoteric polymer, from the same viewpoint, the water-soluble polymer The blending amount is preferably from 0.3 part by weight to 33 parts by weight, particularly preferably from 0.3 part by weight to 18 parts by weight, per 100 parts by weight of the main body fiber. Further, in the case where the main fiber contains synthetic fibers and the binder contains low-melting synthetic fibers, the binder is preferably formulated in an amount of 20 parts by weight to 100 parts by weight based on 100 parts by weight of the main fibers. The reason for this is that in this case, it is more difficult to cause collapse of the particle shape of the xerogel and the aerogel in the papermaking step or the like, and it is easier to maintain the heat insulating property. Further, in the case where the main fiber contains synthetic fibers and the binder contains low-melting synthetic fibers, the amount of the binder is preferably from 10 parts by weight to 20 parts by weight per 100 parts by weight of the aerogel. The reason for this is that in this case, the heat insulating property of the heat insulating material can be effectively ensured.

<Other components> Others are not particularly limited, and for example, a vegetable strength gel, an aqueous cellulose derivative, or a paper strength enhancer such as sodium citrate which is usually used as a papermaking additive may be added as needed or by size press. A sizing agent such as rosin, carboxymethyl cellulose, alkyl ketene dimer, alkenyl succinic anhydride, yield promoter such as polyacrylamide or sodium citrate, polypropylene decylamine, polyethylene oxide, etc. Adhesives, dyes, pigments, etc. for papermaking. Further, in addition to the above, for example, a dispersant such as a water-soluble polyurethane resin (for example, manufactured by Yoshimura Oil Chemical Co., Ltd., TEXANOL PE-10F, etc.) or an antifoaming agent may be used (for example, Mingcheng Chemical Industry Co., Ltd.) Made by the company, Foamless P new, etc.).

<Properties of Heat Insulation Material> The heat insulating material containing the above components may have a thickness of 15 μm to 1.2 cm, a basis weight of 5 g/m ² to 480 g/m ² , and a density of 0.5 g/cm ^{3 .} Sheet shape of ~1.5 g/cm ³ . It is understood that these values are in the same range as general paper, whereby the heat insulating agent of the present invention has the same appearance and texture as paper. The heat insulating material does not need to be only one layer of the paper sheet, but may be a multilayer structure in which a plurality of sheets are bonded by an adhesive or the like, and polyethylene or the like may be provided on one or both sides of the sheet. A laminated structure of a resin layer. In particular, by adopting a laminated structure, it is possible to prevent the dry gel and the aerogel from falling off from the sheet, and it is possible to improve the strength and heat insulating properties of the entire heat insulating material. Further, from the same viewpoint as described above, the heat insulating material preferably has a thickness of 40 μm to 1.2 mm. In addition, it is more preferable that the thickness is in the range of 40 μm to 1.2 mm, and when the thickness is within this range, the heat insulating performance can be sufficiently maintained in a high state, and the manufacturability, workability, and workability are sufficiently high. Moreover, it can be applied to a fine structure that requires heat insulation or a space where space is limited. In addition, as a heat insulating material which is excellent in workability and can correspond to a curved portion, there is a heat insulating material manufactured by Aspen Co., Ltd. which is obtained by composite sheeting of cerium oxide xerogel or cerium oxide aerogel and fiber (" Cryogel (registered trademark) and "Pyrogel (registered trademark)", but the heat insulating material is a sheet having a thickness of 5 mm or more, and cannot be applied to a portion having a fine structure or a space. In addition, as a heat insulating material which is extremely thin and has excellent workability and is compatible with the curved portion, there is a heat insulating material of Matsushita Electric Co., Ltd. which is made of cerium oxide xerogel and fiber composite sheet ("NASBIS (registered trademark)" ”), about 0.1 mm is the limit of thickness in the nature of the manufacturing method. Therefore, in order to achieve heat insulation in a portion having a fine structure or a space, it is required to have high heat insulation performance and high operability and workability even in comparison with the prior art. The material of the present embodiment can better solve the problem for the heat insulating material of the present embodiment.

<Method for Producing Heat Insulation Material> 1. Preparation of Papermaking Paste 100 parts by weight of the main fiber, 35 parts by weight to 210 parts by weight of the dry gel and/or aerogel, 0.3 parts by weight to 125 parts by weight A part of the binder is added to water and mixed to prepare a mixed slurry, and a papermaking slurry (mixed slurry) is prepared. Further, in the case of using the water-soluble polymer as a binder, it is preferred to add a water-soluble polymer, and a xerogel and/or an aerogel to the host fiber at least suspended in water. In the slurry, the slurry for papermaking is adjusted. Specifically, for example, when pulp is used as the main fiber and porous ceria particles are used as the dry gel and/or aerogel, and the binder contains a water-soluble polymer, it is preferably suspended in water. A slurry for papermaking (mixed slurry) is prepared by adding and mixing porous cerium oxide particles and a binder to the slurry of the pulp.

In the case of preparing a slurry for papermaking, it is preferred to adjust the addition of an acid, an alkali, or the like as needed so that the slurry becomes pH 7 to 8. In particular, when the xerogel and/or the aerogel are hydrophobized methyl citrate or the like, the chemical structure is most easily stabilized under the conditions of pH 7-8. Therefore, in order to maintain the porous structure of the particles, it is also desirable to prepare a slurry under the conditions described.

2. Papermaking step The papermaking slurry is subjected to papermaking using a known paper machine which is usually used in the production of paper. The slit width, the drum diameter, the drum rotation speed, the pressing pressure, the dryer temperature, and the like of the paper machine can be appropriately changed depending on the desired properties of the heat insulating material sheet.

3. With the steps of the papermaking sheet obtained by the papermaking step, a plurality of sheets may be laminated via an adhesive as needed, and a layer of a resin layer such as polyethylene may be provided on one or both sides. Press processing.

Further, in the method for producing the heat insulating material, it is preferred to use a wet papermaking method. The wet papermaking method is a production method in which fibers or the like are dispersed in water and the sheets are formed by wire drawing. In the method for producing a heat insulating material, the main fiber, the dry gel, and/or the aerogel and the binder are dispersed in water, whereby the thickness of the heat insulating material can be 15 μm to 1.2 mm, more preferably It is 40 μm to 1.2 mm.

<Method of Insulating Heat Insulation Material> The heat insulating material of the present invention can provide a heat insulating effect on a target article by a method of packaging a target article or attaching it to a target article. Here, the raw material of the target article is not particularly limited, and any paper, plastic, plate, metal, or the like can be used. For the purpose of use, it can be used in foods, pharmaceutical containers, packaging materials, building materials, and the like. Specifically, the heat insulating material of the present embodiment is used as a heat countermeasure component for an electronic device, for example, together with a heat dissipating material, and is used as an energy saving countermeasure component or a safety countermeasure such as a molding machine, a mold device, and a piping member. It is used as a building member (ceiling, under-floor material, wallpaper, window paper, roller blind); it is used as a vehicle interior member for automobiles and transport vehicles; it is used as a packaging material for imparting heat insulation properties. .

Moreover, the heat insulating material of the present invention can also be used in an electronic device (for example, a mobile phone, a digital camera, etc.) having a heat generating component inside. Specifically, the heat insulating material of the present invention can be used, for example, in an electronic device including a substrate on which a heat generating component is packaged and a case in which the substrate is housed. More specifically, in the electronic device, the heat-resistant sheet can be disposed inside the casing at a position opposed to the heat-generating component via an adhesive layer or the like, and the heat-resistant sheet material includes the heat insulating material of the present invention. The heat insulating sheet having a sheet shape or a heat conductive sheet having high heat conductivity (for example, a graphite sheet or the like). Further, in this case, a heat conductive sheet may be disposed between the heat generating component and the heat insulating sheet, or a heat conductive sheet may be disposed between the casing and the heat insulating sheet (separated from the heat insulating sheet with respect to the heat insulating sheet) On the side of the open, or configured in both. In the case where a heat-conductive sheet is disposed between the heat-generating component and the heat-insulating sheet by using the heat-resistant sheet containing the heat-insulating sheet as described above, first, the high thermal conductivity of the heat-conductive sheet is utilized. The heat generated by the heat-generating component is distributed to the entirety of the heat-conducting sheet surface to prevent the locality from becoming high, and then the heat-dissipating sheet can prevent the diffused heat from being transferred to the casing. Further, in the case where a heat conductive sheet is disposed between the casing and the heat insulating sheet, first, heat is prevented from being transferred to the heat conductive sheet by the heat insulating sheet, and then the heat insulating sheet is transferred to the heat insulating sheet. The small amount of heat distribution of the heat conductive sheet to the entirety of the heat conductive sheet surface prevents the temperature of the casing from rising locally. Therefore, even if the inside of the casing is in a state of high local temperature due to the heat generating component, the temperature of the casing surface can be prevented from rising.

Although the embodiment of the present invention has been described above, the heat insulating material of the present invention is not limited to the above example, and can be appropriately changed. [Examples]

Hereinafter, the present invention will be described in more detail by way of examples, but the invention should not be construed as limited. In order to confirm the effect of the heat insulating material of the present invention, the following two experiments were conducted.

[Experiment 1] <Preparation of heat insulating material> 1. Example 1: Insulating material 300 mL of water was placed in a 500 mL beaker, and 200 g of commercially available kenaf pulp, 100 g of methyl decanoate was added thereto. Critically dried hydrophobic gel powder (average particle size 5 μm, specific surface area 750 m ² /g, Aerogel Enova manufactured by Cabot), 0.8 g cationic starch (made by Japan Food Chemical Co., Ltd. #40T) The pulp slurry was prepared by stirring at 10,000 rpm using a hand blender until the whole was uniform. Next, the pulp slurry was manually subjected to papermaking using a papermaking screen (material: nylon), and dried in a metal mesh at room temperature, thereby obtaining a thickness of 0.2 mm and a basis weight of 200 g/m. ² insulation material (insulation sheet). Further, the appearance, flexibility, and the like of the obtained heat insulating sheet are similar to those of commercially available drawings.

2. Example 2 to Example 5: Heat insulating material Three, five, seven, and ten sheets which were dried on the screen which was subjected to papermaking in the same manner as in Example 1 were superposed and dried. The produced heat insulating sheets were respectively referred to as Example 2, Example 3, Example 4, and Example 5.

3. Comparative Example 1 to Comparative Example 5: Paper was used as a comparative control using a commercially available drawing having a thickness of 0.2 mm and a basis weight of 210 g/m ² . Only one of the above-mentioned drawing sheets was used as the comparative example 1, and three, five, seven, and ten pieces were used as the comparative example 2, the comparative example 3, the comparative example 4, and the comparative example. 5.

<Evaluation of Thermal Insulation Performance> Example 1 was wound so as to cover the outer peripheral surface of a commercially available paper cup (9 ounces, caliber 77 mm × height 91 mm, material: original pulp (outer side), polyethylene (inner side)). The heat insulating sheet of Example 5 and the paper of Comparative Example 1 to Comparative Example 5. At this time, the heat insulating sheet and the paper are not entangled with the paper cup without using an adhesive or the like, and the cellophane tape having a boundary line of only 1 cm wide by about 5 cm is used. ) Tape bonding the outer surface. 250 mL of hot water of 95 ° C was placed in each of the paper cups, and the surface temperature of the outside of the sheet immediately after the insertion, 10 seconds, 20 seconds, and 30 seconds was measured. The measurement results of the surface temperature are shown in Table 1.

[Table 1]

As shown in Table 1, it is clear that the temperature of the hot water inside the paper cup of the heat insulating material (insulation sheet) of the present invention is difficult to conduct compared with plain paper (drawing paper) having the same thickness and basis weight. Excellent thermal insulation to the outer surface.

[Experiment 2] <Preparation of heat insulating material> 1. Example 6: Insulating material Into a 1 L hand blender, 700 mL of water was placed, and 3.5 g of a commercially available polyester fiber (PET) was placed therein. The fiber, TA04PN SD 0.1 dtex × 3 mm manufactured by Teijin Co., Ltd., was stirred at 10,000 rpm until the whole was uniform. Stirring was carried out by adding 1.2 g of vinylon-bonded fiber (VPB 105-1 × 3 mm manufactured by Kuraray Co., Ltd.). A critical dry hydrophobic gel powder (average particle diameter of 90 μm, specific surface area of 750 m ² /g, Aerogel Enova manufactured by Cabot) was added to the slurry with the addition of 7.0 g of methyl citrate, and the mixture was stirred in the same manner. The pulp for papermaking is adjusted. Then, papermaking was carried out in the same manner as in Example 1 and dried by a rotary dryer to obtain a heat insulating material (insulation sheet) having a thickness of 0.25 mm and a basis weight of 100 g/m ² . The case where only two of the heat insulating materials were used was used as Example 6 (the thickness of the heat insulating material of Example 6 was 0.5 mm). Further, the appearance, flexibility, and the like of the obtained heat insulating sheet are similar to those of a commercially available nonwoven fabric.

2. Example 7 to Example 9: Insulating materials Four, six, and eight heat insulating materials produced by the same method as in Example 6 were used in the same manner as Examples 7 and Examples, respectively. 8. Example 9 (The thickness of the heat insulating material of each of the examples was 1.0 mm, 1.5 mm, 2.0 mm).

3. Comparative Example 6 to Comparative Example 9: Non-woven fabric using 0.25 mm non-woven fabric (100 parts by weight of polyester fiber (TA04PN SD 0.1 dtex × 3 mm manufactured by Teijin Co., Ltd.), and 33.3 parts by weight of vinylon bonded fiber (Kuraray Co., Ltd.) VPB105-1×3 mm) manufactured by the company) as a comparative control. Only two of the non-woven fabrics were used as the comparative example 6, and four, six, and eight were used as the comparative example 7, the comparative example 8, and the comparative example 9, respectively.

4. Example 10: Insulating material 700 mL of water was placed in a 1 L hand blender, and 3.5 g of commercially available polyester fiber (PET fiber, TA04PN SD 0.1 dtex×3 manufactured by Teijin Co., Ltd.) was placed therein. Mm), stirring at 10,000 rpm until the whole is uniform. To the mixture, 1.2 g of a polyester binder fiber (PET adhesive fiber, TK08PN SD 0.2 dtex × 3 mm manufactured by Teijin Co., Ltd.) was added and stirred. Further, 3.1 g of cationic starch (manufactured by Nippon Food & Chemical Co., Ltd. #40T) and 7.0 g of methyl citrate as a critical dry hydrophobic gel powder (having an average particle diameter of 90 μm and a specific surface area of 750 m ² /g, Aerogel Enova manufactured by Cabot Corporation was stirred in the same manner to adjust the slurry for papermaking. Then, papermaking was carried out in the same manner as in Example 1 and dried by a rotary dryer to obtain a heat insulating material (insulation sheet) having a thickness of 0.25 mm and a basis weight of 130 g/m ² . The use of only two of the heat insulating materials was carried out as Example 10 (the thickness of the heat insulating material of Example 10 was 0.5 mm). Further, the appearance, flexibility, and the like of the obtained heat insulating sheet are similar to those of a commercially available nonwoven fabric.

5. Example 11 to Example 13: Insulation materials: Four, six, and eight heat insulating materials produced by the same method as in Example 10 were used in the same manner as Examples 11 and Examples, respectively. 12. Example 13 (The thickness of the heat insulating material of each of the examples was 1.0 mm, 1.5 mm, 2.0 mm).

6. Comparative Example 10 to Comparative Example 13: Non-woven fabric using 0.25 mm non-woven fabric (100 parts by weight of polyester fiber (TA04PN SD 0.1 dtex × 3 mm manufactured by Teijin Co., Ltd.), 33.3 parts by weight of polyester bonded fiber (PET bonded fiber) TK08PN SD 0.2 dtex × 3 mm) manufactured by Teijin Co., Ltd., 36 parts by weight of cationic starch (manufactured by Nippon Food Chemical Co., Ltd. #40T) was used as a comparative control. The two non-woven fabrics were used as the comparative example 10, and four, six, and eight were used as the comparative example 11, the comparative example 12, and the comparative example 13, respectively.

<Evaluation of Thermal Insulation Property> The heat insulating sheets (40 mm × 40 mm) of Examples 6 to 13 were placed on a stainless steel cylinder (diameter: 47 mm, height: 57 mm) heated to about 100 °C. Nonwoven fabrics (40 mm × 40 mm) of Comparative Examples 6 to 13. The surface temperatures of the sheet and the upper surface side of the nonwoven fabric (the side opposite to the side where the sheet and the non-woven fabric were in contact with the cylinder) were measured after 10 seconds, 20 seconds, 30 seconds, and 60 seconds. The measurement results of this surface temperature are shown in Table 2.

[Table 2]

As shown in Table 2, it is clear that the temperature of the stainless steel cylinder of the heat insulating material (heat insulating sheet) of the present invention is hard to be transmitted and the heat insulating performance is excellent as compared with the nonwoven fabric of the same thickness.

no

no

no

Claims (9)

A heat insulating material comprising at least one water-soluble polymer selected from the group consisting of a cationic polymer and an amphoteric polymer, and/or a low melting point, comprising a host fiber, a xerogel, and/or an aerogel. A heat insulating material for a binder of a synthetic fiber, characterized in that the dry gel and the aerogel have a density of less than 0.5 g/cm ³ and a thermal conductivity of 0.02 W/(m·K) or less, relative to 100 parts by weight. The main fiber is formulated to have a total weight of from 35 parts by weight to 210 parts by weight of the dry gel and/or aerogel. The heat insulating material according to claim 1, wherein the binder contains the water-soluble polymer, and the water-soluble polymer is at least one of a cationized starch and an amphoteric starch. The heat insulating material according to claim 1 or 2, wherein the binder contains the low melting point synthetic fiber, and the low melting point synthetic fiber is a vinylon binder fiber. The heat insulating material according to any one of claims 1 to 3, wherein the xerogel and the aerogel are dry gelled by atmospheric drying of a methyl citrate monomer or Porous cerium oxide particles obtained by aerogelation using critical drying. The heat insulating material according to any one of claims 1 to 4, wherein the dry gel and the aerogel have an average particle diameter of 2 μm to 140 μm and a specific surface area of 400 m ² /g or more. The heat insulating material according to any one of claims 1 to 5, which has a thickness of 15 μm to 1.2 cm, a basis weight of 5 g/m ² to 480 g/m ² , and a density of 0.5. A sheet of g/cm ³ to 1.5 g/cm ³ is used. A method for producing a heat insulating material, characterized in that 100 parts by weight of the main fiber has a total density of less than 0.5 g/cm ³ and a thermal conductivity of 0.02 W/(m·K) or less and a total weight of 35 parts by weight to 210 parts by weight The dry gel and/or aerogel containing 0.3 parts by weight to 125 parts by weight of at least one water-soluble polymer and/or low-melting synthetic fiber selected from the group consisting of cationic polymers and amphoteric polymers A part of the binder is added to water and mixed to prepare a mixed slurry, and the mixed slurry is subjected to papermaking. The method for producing a heat insulating material according to claim 7, wherein the mixed slurry at the time of papermaking is pH 7 to 8. The method for producing a heat insulating material according to claim 7 or 8, wherein the binder of the mixed slurry contains the water-soluble polymer, the water-soluble polymer, and the The dry gel and/or aerogel is added and mixed in a slurry in which at least the host fiber is suspended in water, and the mixed slurry is adjusted.