JP5615514B2 - Heat insulating material, heat insulating structure using the same, and method for manufacturing heat insulating material - Google Patents

Description

  The present invention relates to a heat insulating material, a heat insulating structure using the heat insulating material, and a method for manufacturing the heat insulating material, and more particularly to thinning the heat insulating material.

  Conventionally, for example, in Patent Document 1, a heat insulating layer made of inorganic fibers such as alumina silica fibers and a low dust-generating heat insulating material having a coating layer made of a heat resistant resin such as a fluororesin that covers the heat insulating layer The materials are listed.

JP 2004-150540 A

  However, in the above prior art, since a heat insulating layer made of inorganic fibers is used, there is a limit to reducing the thickness while sufficiently maintaining the heat insulating property of the heat insulating layer.

  An object of the present invention is to provide a heat insulating material that can be thinned while maintaining heat insulation, a heat insulating structure using the heat insulating material, and a method for manufacturing the heat insulating material. I will.

  In order to solve the above problems, a heat insulating material according to an embodiment of the present invention includes a heat insulating layer made of a nanoparticle compression-molded body or a fiber filled with airgel, and a porous coating layer covering the heat insulating layer. It is characterized by having. ADVANTAGE OF THE INVENTION According to this invention, the heat insulating material which can be reduced in thickness can be provided, maintaining heat insulation.

  Moreover, the said heat insulation layer consists of a compression molding body of the said nanoparticle, and the said compression molding body is good also as further containing a fiber material. If it carries out like this, the heat insulation of a heat insulating material can be maintained effectively. In this case, the nanoparticles may be dry silica or wet silica. If it carries out like this, the heat insulation of a heat insulating material can be improved effectively. Moreover, the said heat insulation layer consists of a fiber body with which the said airgel was filled, and the said airgel is good also as being a silica airgel. If it carries out like this, the heat insulation of a heat insulating material can be improved effectively. The coating layer may be made of a resin made porous by a stretching method. If it carries out like this, the dust generation of a heat insulating material can be prevented effectively.

  Moreover, the said coating layer is good also as consisting of a porous cylindrical molded object. If it carries out like this, the heat insulation of a heat insulating material can be improved more effectively. Further, in this case, a porous second covering layer that covers the heat insulating layer is further provided, and the covering layer made of the cylindrical molded body covers the heat insulating layer covered with the second covering layer. It is good to do. If it carries out like this, the dust generation property of a heat insulating material can also be improved. Furthermore, in these cases, the heat insulating material may be formed by inserting the heat insulating layer into the cylindrical molded body. If it carries out like this, it can be set as the heat insulating material which can manufacture simply and has the outstanding heat insulation reliably.

  Moreover, it may further include a radiation reflecting layer laminated on the heat insulating layer, and the covering layer may cover the heat insulating layer and the radiation reflecting layer. If it carries out like this, the heat insulation of a heat insulating material can be improved more effectively. Moreover, the said heat insulation layer is good also as containing an infrared reflective agent or an infrared absorber. If it carries out like this, the heat insulation of a heat insulating material can be improved more effectively.

  The heat insulating structure according to an embodiment of the present invention for solving the above-described problem includes a pipe to be heat-insulated and any one of the heat insulating materials wound around the outer periphery of the pipe a plurality of times. Features. According to the present invention, it is possible to provide a heat insulating structure in which a heat insulating material is thinned while maintaining heat insulating properties.

  In order to solve the above problems, a method for manufacturing a heat insulating material according to an embodiment of the present invention includes a heat insulating layer made of a fibrous body in which a porous cylindrical molded body is filled with a nanoparticle compression molded body or an airgel. By inserting, the heat insulating material which has the said heat insulation layer and the coating layer which consists of the said cylindrical molded object which coat | covers the said heat insulation layer is manufactured, It is characterized by the above-mentioned. ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the heat insulating material which can be reduced in thickness while maintaining heat insulation can be provided.

  Moreover, in this manufacturing method, it is good also as manufacturing the said heat insulating material by inserting the said heat insulation layer previously coat | covered with the porous 2nd coating layer in the said cylindrical molded object. If it carries out like this, the heat insulating material which has the outstanding heat insulation can be manufactured simply and reliably.

  ADVANTAGE OF THE INVENTION According to this invention, the heat insulating material which can be reduced in thickness, maintaining heat insulation, the heat insulation structure using this, and its manufacturing method can be provided.

It is a perspective view about an example of the member which constitutes the heat insulating material concerning one embodiment of the present invention. It is a top view about an example of the heat insulating material which concerns on one Embodiment of this invention. It is sectional drawing of the heat insulating material cut | disconnected by the III-III line | wire shown in FIG. It is sectional drawing about the other example of the heat insulating material which concerns on one Embodiment of this invention. It is sectional drawing about an example of the heat insulating material which has a radiation reflection layer which concerns on one Embodiment of this invention. It is a perspective view about an example of the cylindrical fabrication object concerning one embodiment of the present invention. It is explanatory drawing which shows the main processes contained in an example of the manufacturing method of the heat insulating material which concerns on one Embodiment of this invention. It is a top view about an example of the heat insulating material which has a coating layer which consists of a cylindrical fabrication object concerning one embodiment of the present invention. It is sectional drawing of the heat insulating material cut | disconnected by the IX-IX line shown in FIG. It is sectional drawing of the heat insulating material cut | disconnected by the XX line shown in FIG. It is a top view about an example of the heat insulating material which has the 2nd coating layer concerning one embodiment of the present invention. It is sectional drawing of the heat insulating material cut | disconnected by the XII-XII line | wire shown in FIG. It is a perspective view about an example of the heat insulation structure concerning one embodiment of the present invention. It is sectional drawing about the other example of the heat insulation structure which concerns on one Embodiment of this invention. It is a top view about the other example of the heat insulation structure concerning one embodiment of the present invention. It is sectional drawing of the heat insulation structure cut | disconnected by the XVI-XVI line shown in FIG. It is explanatory drawing which shows an example of the result of having measured the flexibility and heat conductivity of the heat insulation layer which concern on one Embodiment of this invention. It is explanatory drawing which shows an example of the result of having measured the flexibility and thermal conductivity of the coating layer which concern on one Embodiment of this invention. It is explanatory drawing which shows an example of the result of having measured the heat conductivity of the heat insulating material which concerns on one Embodiment of this invention. It is explanatory drawing which shows an example of the result of having measured the dust generation property of the heat insulating material which concerns on one Embodiment of this invention. It is explanatory drawing which shows the other example of the result of having measured the dust generation property of the heat insulating material which concerns on one Embodiment of this invention. It is explanatory drawing which shows the further another example of the result of having measured the dust generation property of the heat insulating material which concerns on one Embodiment of this invention. It is explanatory drawing which shows an example of the result of having measured the thermal conductivity of the heat insulating material which has a radiation reflection layer which concerns on one Embodiment of this invention. It is explanatory drawing which shows the other example of the result of having measured the thermal conductivity of the heat insulating material which has a radiation reflection layer which concerns on one Embodiment of this invention. It is explanatory drawing which shows an example of the result of having measured the thermal conductivity of the heat insulating material which has the infrared reflective agent which concerns on one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described. Note that the present invention is not limited to this embodiment.

  FIG. 1 is a perspective view of an example of a member constituting a heat insulating material (hereinafter referred to as “the main heat insulating material 1”) according to the present embodiment. FIG. 2 is a plan view of an example of the heat insulating material 1. FIG. 3 is a cross-sectional view of the heat insulating material 1 cut along the line III-III shown in FIG.

  As shown in FIGS. 1 to 3, the heat insulating material 1 has a heat insulating layer 10. The heat insulating layer 10 is made of a nanoparticle compression molded body or a fiber body filled with airgel.

The nanoparticle compression-molded body is a heat-insulating structure that can be produced by compression-molding the nanoparticles. As a nanoparticle, the thing whose average diameter of the primary particle is 1-100 nm can be used, for example. The average diameter of the primary particles of the nanoparticles can be preferably in the range of 1 to 50 nm, more preferably in the range of 1 to 25 nm, still more preferably in the range of 1 to 15 nm. Particularly preferably, it can be in the range of 1 to 10 nm. In addition, this average diameter is expressed by the formula “D = 6 / () when the true density (g / m ³ ) of the nanoparticles is“ a ”and the specific surface area (m ² / g) of the nanoparticles is“ S ”. a × S) ”is a converted particle diameter D (m). For example, since the true density of silica is 2.2 × 10 ⁶ g / m ³ , the average diameter (converted particle diameter) of silica nanoparticles having a specific surface area of 300 m ² / g is calculated to be about 9 nm.

  Primary particles having an average diameter of 100 nm or less can be aggregated to form secondary particles. For this reason, the compression-molded body of nanoparticles becomes an aggregate of secondary particles of the nanoparticles. And the size of the space | gap formed in a secondary particle can be reduced by using the nanoparticle with a small average diameter of a primary particle. Further, by reducing the size of the gap, air convection in the compression molded body can be effectively prevented. Therefore, for example, a compression-molded body of nanoparticles (so-called single nanoparticles) in which the average diameter of primary particles is less than 10 nm can have excellent heat insulating properties.

  As a nanoparticle, the nanoparticle (inorganic nanoparticle) which consists of inorganic materials, or the nanoparticle (organic nanoparticle) which consists of organic materials can be used. By using inorganic nanoparticles, the heat resistance of the compression molded product can be effectively increased.

  As the inorganic nanoparticles, for example, nanoparticles made of a metal oxide such as silica, alumina, titanium oxide or the like can be preferably used. Especially, the heat insulation of a compression molding body can be effectively improved by using the nanoparticle (silica nanoparticle) which consists of silica. Therefore, the compression molded body of silica single nanoparticles can have particularly excellent heat insulation.

  As silica nanoparticles, dry silica (so-called fumed silica) produced by a gas phase method or wet silica produced by a liquid phase method can be preferably used. As dry silica, hydrophilic fumed silica having abundant hydrophilic groups such as silanol groups on its surface, or hydrophobic fumed silica produced by subjecting the surface of the hydrophilic fumed silica to hydrophobic treatment Can be used. Hydrophobic fumed silica compression-molded bodies are less susceptible to thermal insulation degradation due to moisture absorption than hydrophilic fumed silica compression-molded bodies.

  The compression molded body can further contain a fiber material in addition to the nanoparticles. The compression-molded body containing the fiber material can effectively maintain the heat insulating property as compared with the compression-molded body not containing the fiber material.

  That is, for example, in a compression molded body that does not contain a fiber material, when the compression molded body is bent, a crack that tears the compression molded body is easily formed. Since such a crack forms an air layer that penetrates the compression molded body, the heat insulating property of the compression molded body decreases due to the formation of the crack.

  On the other hand, in a compression molded body containing a fiber material, even when the compression molded body is bent, cracks are hardly formed. Even if a crack is formed, the fiber material in the compression molded body effectively prevents the compression molded body from being broken by the crack. Therefore, the fiber material can impart excellent flexibility without a decrease in heat insulation to the compression molded body.

  When the compression molded body contains a fiber material, the fiber material can be, for example, dispersed and irregularly oriented fibers in the compression molded body. As such a fiber, a fiber made of an inorganic material (inorganic fiber) or a fiber made of an organic material (organic fiber) can be used.

  As the inorganic fiber, for example, glass fiber or ceramic fiber such as alumina fiber can be used. As the organic fiber, for example, an aramid fiber, a carbon fiber, or a polyester fiber can be used.

  Moreover, as a fiber contained in a compression molding body, the chopped fiber manufactured by cut | disconnecting the long fiber (filament) with a fixed fiber diameter (fiber diameter) to predetermined length can be used, for example. Specifically, for example, chopped glass fibers can be used.

As the chopped fiber, for example, one having an average fiber diameter in the range of 3 to 15 μm and an average length in the range of 1 to 20 mm can be used, and preferably the average fiber diameter is in the range of 6 to 12 μm. The thing of the range of 3-9 mm can be used. As the fiber diameter of the chopped fiber is smaller and the fiber length is larger, the flexibility such as the flexibility of the compression molded body is improved, and the formation of cracks due to deformation in the compression molded body can be effectively prevented. it can.

  Moreover, as a fiber contained in a compression molding, the short fiber (staple fiber) with a nonuniform fiber diameter and fiber length can be used, for example. Specifically, for example, aramid short fibers can be used. As this aramid short fiber, for example, a fiber obtained by fiberizing paraphenylene terephthalamide, which is a polycondensate of terephthalic acid dichloride and paraphenylenediamine, by a dry spinning method can be used. The staple fiber can be produced by, for example, a melt blow method. Moreover, as a staple fiber, the thing of the range whose fiber diameter is 0.1-12 micrometers can be used preferably, for example.

  By using the fibers as described above, it is possible to effectively prevent the occurrence of cracks that tear the compression molded body in the compression molded body. Therefore, the compression-molded body containing such fibers can have excellent flexibility that can be flexibly deformed without being accompanied by a decrease in heat insulation.

  Moreover, the ratio of the nanoparticles and fibers contained in the compression molded body is appropriately set according to the characteristics (for example, heat insulation, flexibility, heat resistance, low dust generation) that the compression molded body should have. be able to. That is, the compression-molded body can contain, for example, nanoparticles in a range of 50 to 99% by weight and fibers in a range of 1 to 50% by weight, preferably 70 to 99% by weight of nanoparticles. The fibers can be contained in the range of 1 to 30% by weight and more preferably the nanoparticles are contained in the range of 80 to 99% by weight and the fibers are contained in the range of 1 to 20% by weight. be able to.

  Since the thermal conductivity of the fiber or aggregate thereof is larger than the thermal conductivity of the nanoparticles or aggregate thereof, when the ratio of the fiber contained in the compression molded body increases, the heat insulating property of the compression molded body increases. There is a tendency to decrease. For this reason, as above-mentioned, it is preferable that a compression molding body contains a nanoparticle as a main component and contains a fiber as an additive (subcomponent). As described above, the fibers added to the compression molded body can impart flexibility to the compression molded body while maintaining the heat insulating property of the compression molded body. Therefore, it can be said that such a fiber is added as a shape-retaining material or a reinforcing material.

Moreover, the density of the compression-molded body containing fibers can be, for example, in the range of 80 to 400 kg / m ³ , preferably in the range of 100 to 300 kg / m ³ , and more preferably 120 to 400 kg / m ^3. It can be in the range of 250 kg / m ³ .

  Specifically, for example, when the compression molded body contains dry nanoparticles in the range of 70 to 99% by weight and glass fibers in the range of 1 to 30% by weight, the specific gravity of the nanoparticles and the specific gravity of the fibers Are approximately the same, the density of the compression molded body is in the above-described range.

  By increasing the density of the compression molded body, the heat insulating property of the compression molded body can be enhanced. This is considered to be because, for example, the volume of voids formed between the secondary particles of the nanoparticles in the compression molded body is reduced as the density increases. On the other hand, when the density of the compression molded body increases, the rigidity of the compression molded body also increases.

  Therefore, it is preferable to adjust the density of the compression molded body to an appropriate range as described above in consideration of the balance between heat insulation and flexibility that the compression molded body should have. In addition, the density of a compression molding body can be adjusted with the compression conditions at the time of shape | molding the said compression molding body, for example.

  Moreover, when a compression molding body contains a fiber material, the said fiber material can be made into the fiber base material previously formed in the predetermined shape, for example. As such a fiber base material, a woven or non-woven fabric of inorganic fibers or organic fibers can be used.

  The compression molded body can further contain a binder (binder) regardless of whether or not it contains a fiber material. Specifically, as the binder, for example, an organic binder such as a fluorine resin, a polyimide resin, or a PET resin, or an inorganic binder such as a glass frit can be used.

  Since the thermal conductivity of the binder is larger than the thermal conductivity of the nanoparticles or aggregates thereof, when the amount of the binder contained in the compression molded body increases, the heat insulating property of the compression molded body tends to decrease. . For this reason, it is preferable to reduce the binder content as much as possible. Specifically, the binder content in the compression molded body is preferably 40% by weight or less, and more preferably 20% by weight or less.

  And from a viewpoint of improving the heat insulation of a compression molded object, it is most preferable that the said compression molded object does not contain a binder. In this respect, the above-described compression molded body not containing the fiber material and the compression molded body containing the fiber material can be produced without containing any binder.

  The compression molding body which comprises the heat insulation layer 10 can be manufactured by compressing the powder of a nanoparticle and shape | molding in a predetermined shape. That is, for example, a nano-sized powder is spread in a mold having a predetermined shape, and the powder is then compressed in the mold to obtain a compression-molded body having the predetermined shape. In addition, for example, by continuously supplying nanoparticle powder to a compression molding apparatus equipped with a roller and compressing the powder with the roller, a belt-like compression molded body extending continuously for a long time can be obtained.

  Moreover, when manufacturing the compression molding body containing a fiber material, the powder of a nanoparticle and the said fiber material are compression-molded integrally. That is, for example, nanoparticles and fibers (for example, chopped fibers and staple fibers) are mixed at a predetermined weight ratio to prepare a mixed powder in which the fibers are dispersed in the nanoparticle powder, and the mixed powder By compressing, a compression-molded body containing the dispersed fibers can be produced. Also, for example, by compressing the nanoparticle powder on one or both sides of a fiber base material (woven fabric or non-woven fabric), and then compressing the powder on the fiber base material, the fiber base material and the nanoparticles are compressed. A compression molded body in which a molding layer is laminated can be manufactured.

  On the other hand, a fiber body (aerogel fiber body) filled with airgel is a heat insulating structure that can be manufactured by filling a fiber base material with airgel. As the fiber base material, a woven or non-woven fabric of inorganic fibers or organic fibers can be used. By using a nonwoven fabric in which fibers are entangled irregularly as a fiber base material, the airgel can be more effectively held between the fibers.

  Moreover, as a fiber which comprises a fiber base material, ceramic fibers, such as resin fibers, such as a polyethylene terephthalate (PET) fiber, carbon fiber, an alumina fiber, can be used, for example.

  As the airgel, an airgel made of an inorganic material (inorganic airgel) or an airgel made of an organic material (organic airgel) can be used. By using the inorganic airgel, the heat resistance of the airgel fiber can be effectively increased.

  As the inorganic airgel, for example, silica airgel or alumina airgel can be used. Especially, the heat insulation of an airgel fiber body can be effectively improved by using a silica airgel.

  Moreover, the ratio of the airgel and the fiber base material contained in the airgel fiber body is appropriately set according to the characteristics (for example, heat insulation, flexibility, heat resistance, dust generation property) that the airgel fiber body should have. be able to.

Moreover, the density of an airgel fiber body can be made into the range of 20-500 kg / m < ³ >, for example, Preferably it can be set as the range of 100-300 kg / m < ³ >.

  Moreover, the airgel fiber body can further contain a binder. However, as in the case of the compression-molded body, in the airgel fiber body, the binder content is preferably reduced as much as possible, and the airgel fiber body most preferably does not contain the binder. In this regard, the above-described airgel fiber body can be produced without containing a binder.

  The airgel fiber body which comprises the heat insulation layer 10 can be manufactured by carrying out the supercritical drying of the fiber base material which the raw material of the airgel was impregnated. And the airgel which fills the space | gap between fibers can prevent effectively the convection of the air in an airgel fiber body by the micropore in the said airgel. For this reason, an airgel fiber body can have the outstanding heat insulation.

  Moreover, the heat insulation layer 10 can contain an infrared reflective agent or an infrared absorber. The infrared reflecting agent is not particularly limited as long as it has the property of reflecting infrared rays. For example, an infrared reflecting material such as silicon carbide, titanium oxide, zinc oxide, iron oxide, or the like can be used. These particles (infrared reflective particles) can be preferably used. The infrared absorber is not particularly limited as long as it has the property of absorbing infrared rays. For example, a black material (infrared absorbing material) such as carbon or graphite can be used, and particles (infrared rays) of the infrared absorbing material can be used. Absorbent particles) can be preferably used.

  The heat insulation layer 10 can contain an infrared reflective agent or an infrared absorber on the surface or inside thereof. That is, for example, an infrared reflector or an infrared absorber can be dispersed inside the heat insulating layer 10. Further, for example, a layer made of an infrared reflecting agent or an infrared absorbing agent can be formed on the surface or inside of the heat insulating layer 10. The content of the infrared reflector or infrared absorber in the heat insulating layer 10 can be, for example, in the range of 5 to 40% by weight, and preferably in the range of 10 to 30% by weight.

  The heat insulating layer 10 of the heat insulating material 1 has a high heat insulating property compared to a heat insulating material made of a conventional inorganic fiber by being composed of a nanoparticle compression molded body or an airgel-filled fiber molded body as described above. be able to.

  That is, the thermal conductivity of the heat insulating layer 10 at 25 ° C. can be set to, for example, 0.024 W / m · K or less, preferably 0.020 W / m · K or less, more preferably 0. .018 W / m · K or less. Further, the heat conductivity of the heat insulating layer 10 at 80 ° C. can be, for example, 0.035 W / m · K or less, preferably 0.027 W / m · K or less, more preferably 0. 0.025 W / m · K or less.

  Furthermore, when the heat insulation layer 10 contains an infrared reflecting agent or infrared absorbing agent, it is possible to effectively block the radiant heat from the heat source, so that the heat insulation is effectively improved compared to the case where these are not contained. be able to.

  Thus, since the heat insulation layer 10 has the outstanding heat insulation, it can reduce in thickness, maintaining sufficient heat insulation. Specifically, the thickness of the heat insulation layer 10 can be, for example, in the range of 1 to 9 mm, preferably in the range of 1 to 5 mm, and more preferably in the range of 1 to 4 mm. More preferably, it can be in the range of 1 to 3 mm. By reducing the thickness of the heat insulating layer 10, the flexibility of the heat insulating layer 10 can be improved.

  Moreover, this heat insulating material 1 has the porous coating layer 20 which coat | covers the heat insulation layer 10, as shown in FIGS. In the example shown in FIGS. 1 to 3, the covering layer 20 is formed in a bag shape and houses the heat insulating layer 10 therein. The coating layer 20 can be formed from a porous sheet, for example. The porous sheet is superior in flexibility compared to the non-porous sheet.

  As the porous sheet constituting the coating layer 20, a porous resin sheet can be preferably used. As the porous resin sheet, a resin sheet (stretched resin sheet) made porous by a stretching method can be preferably used. As this stretched resin sheet, any of those made porous by the uniaxial stretching method and those made porous by the biaxial stretching method can be used.

  The porous structure of the stretched resin sheet is a complex multilayer structure in which a plurality of holes are formed in a three-dimensional manner from the surface on one side to the surface on the other side of the stretched resin sheet. For this reason, when this heat insulating material 1 has the coating layer 20 which consists of an extending | stretching resin sheet, it is effective that the dust generated from the heat insulation layer 10 in the said coating layer 20 leaks out of the said coating layer 20. Can be prevented.

  Examples of the stretched resin sheet include, for example, a fluororesin sheet such as a polytetrafluoroethylene (PTFE) sheet (stretched PTFE sheet) that has been made porous by a stretching method, and a polyolefin resin such as a polyethylene sheet or a polypropylene sheet. Made sheets can be used. Especially, the heat resistance and heat insulation of the said coating layer 20 can be improved effectively by forming the coating layer 20 using an expanded PTFE sheet.

  Moreover, the thickness of the porous sheet which comprises the coating layer 20 can be made into the range of 10-2000 micrometers, for example, Preferably it can be set as the range of 30-1000 micrometers, More preferably, it is the range of 50-800 micrometers. It can be.

  Since the heat conductivity of the porous sheet is larger than the heat conductivity of the heat insulating layer 10, the heat insulating property of the heat insulating material 1 can be effectively improved by reducing the thickness of the porous sheet. . Moreover, the flexibility of the coating layer 20 can be increased by reducing the thickness of the porous sheet.

  The heat insulating material 1 can be manufactured from, for example, a heat insulating layer 10 and two porous covering sheets 21 and 22 as shown in FIGS. That is, first, one heat insulating layer 10 formed into a sheet shape is sandwiched between one covering sheet 21 and the other covering sheet 22.

  Next, the outer peripheral portion 21 a of one covering sheet 21 and the outer peripheral portion 22 a of the other covering sheet 22 that are overlapped with each other are bonded to form a bag-shaped covering layer 20 that covers the heat insulating layer 10. .

  Adhesion of the outer peripheral portions 21a and 22a of the covering sheets 21 and 22 can be performed by, for example, heat welding or stitching. When the covering sheets 21 and 22 are resin sheets, it is preferable that the outer peripheral portions 21a and 22a are bonded by thermal welding. By using thermal welding, for example, dust generated from the heat insulating layer 10 inside the coating layer 20 can be effectively prevented from leaking from the outer peripheral portions 21a and 22a of the coating layer 20.

  Further, when the outer peripheral portions 21a and 22a of the covering sheets 21 and 22 are sewn, it is preferable to apply a sealing process to the stitched portions with a resin. That is, first, resin powder is applied to the stitched portions of the outer peripheral portions 21a and 22a, and then the resin powder is heated and melted, so that the melted resin is immersed in the seam. Thereby, it can prevent effectively that the dust which generate | occur | produced from the heat insulation layer 10 inside the coating layer 20 leaks out from the outer peripheral parts 21a and 22a of the said coating layer 20. FIG. As the sealing resin, for example, fluororesins such as PTFE and PFA, modified fluororesins, silicone, modified silicone, polyamide, polyamideimide, and PET can be used.

  In addition, for example, a suture that is melted by heating (a heat-meltable suture) can be used for the suturing. The heat-meltable suture is not particularly limited as long as it is a suture made of a resin that is melted by heating. For example, a suture made of a thermoplastic resin such as PTFE, PFA, or FEP can be used.

  In this case, first, the outer peripheral portions 21a and 22a of the covering sheets 21 and 22 are sewn with a hot melt suture, and then the outer peripheral portion at a temperature equal to or higher than the melting point of the resin constituting the hot melt suture. 21a and 22a are heated. As a result, the heat-meltable suture can be melted and the melted resin can be soaked into the seam. As a result, it is possible to effectively prevent the dust generated from the heat insulating layer 10 inside the coating layer 20 from leaking from the outer peripheral portions 21a and 22a of the coating layer 20.

  One of the two coating sheets 21 and 22 constituting the coating layer 20 may be a porous sheet and the other may be a non-porous sheet. That is, for example, the coating layer 20 can be composed of a non-porous coating sheet 21 and a porous coating sheet 22. In this case, the dust generation from the part which consists of the non-porous coating sheet | seat 21 among the coating layers 20 can be prevented reliably.

  As the non-porous coating sheet 21, for example, a heat-resistant resin sheet can be preferably used. As the heat resistant resin sheet, for example, a film of PFA, polyamide, polyamideimide, or PET can be preferably used.

  Since the non-porous coating sheet 21 does not have a pore structure like the porous coating sheet 22, a non-porous coating sheet 21 having a reduced thickness compared to the porous coating sheet 22 may be used. it can. Specifically, the thickness of the non-porous covering sheet 21 can be, for example, in the range of 1 to 100 μm, preferably in the range of 5 to 50 μm, and more preferably in the range of 8 to 20 μm. It can be a range.

  The covering layer 20 is not limited to the one formed from the two porous covering sheets 21 and 22 as described above. That is, for example, as shown in FIG. 4, the covering layer 20 is formed by folding one porous covering sheet so as to wrap the heat insulating layer 10, and overlapping the end portion 23 of the covering sheet as described above. It can be formed by bonding by heat welding or stitching. In this case, this heat insulating material 1 will have the adhesion part (end part 23 shown in FIG. 4) extended in a longitudinal direction only in the one side of the width direction.

  In addition, the heat insulating material 1 may further include a radiation reflection layer laminated on the heat insulating layer 10. In this case, the covering layer 20 covers the heat insulating layer 10 and the radiation reflecting layer. The radiation reflection layer is not particularly limited as long as it has a property of reflecting radiation, and can be, for example, a metal thin film that reflects radiation. Specifically, the radiation reflection layer can be formed from, for example, an aluminum foil or a stainless steel foil. The thickness of the radiation reflection layer can be, for example, in the range of 5 to 100 μm, and preferably in the range of 10 to 50 μm.

  FIG. 5 is a cross-sectional view of an example of the heat insulating material 1 in this case. In the example shown in FIG. 5A, the heat insulating material 1 has a radiation reflecting layer 30 laminated on one side of the heat insulating layer 10. That is, the radiation reflecting layer 30 made of a metal thin film such as an aluminum foil is disposed along the surface on one side of the heat insulating layer 10 formed in a sheet shape. Further, in the example shown in FIG. 5B, the heat insulating material 1 has two radiation reflecting layers 30 a and 30 b laminated on one side and the other side of the heat insulating layer 10, respectively. In the example shown in FIG. 5C, the heat insulating material 1 has a radiation reflecting layer 30 laminated between a pair of heat insulating layers 10a and 10b. That is, the radiation reflection layer 30 is disposed so as to be sandwiched between the one heat insulating layer 10a and the other heat insulating layer 10b. In addition, although the radiation reflection layer 30 is not restricted to the example shown in FIG. 5, it is preferable to arrange | position in the position close | similar to a heat source among this heat insulating materials 1. FIG.

  When the heat insulating material 1 has the radiation reflecting layer 30, the heat reflecting property of the heat insulating material 1 can be improved because the radiation reflecting layer 30 can effectively block the radiant heat from the heat source. That is, the thermal conductivity of the heat insulating material 1 can be reduced by 10 to 20% by having the radiation reflection layer 30 as compared to the case without the radiation reflection layer 30.

  Moreover, this heat insulating material 1 can have the coating layer 20 which consists of a porous cylindrical molded object. FIG. 6 is a perspective view of an example of the tubular molded body 40. In the example shown in FIG. 6, the tubular molded body 40 is a tubular molded body in which a hollow portion 41 that can accommodate the heat insulating layer 10 is formed. In addition, the cross-sectional shape of the cylindrical molded body 40 is not limited to the circular shape as illustrated in FIG. 6, and may be an elliptical shape or a polygonal shape, for example.

  The entire tubular molded body 40 is integrally formed of a porous material and does not have a seam portion in the circumferential direction. That is, for example, as described above, when the belt-shaped main heat insulating material 1 having the covering layer 20 made of the covering sheet is manufactured, the entire heat insulating material 1 is bonded to all or part of the outer peripheral portion of the covering sheet. The material 1 has seam portions extending in the longitudinal direction, such as outer peripheral portions 21a and 22a shown in FIGS. 2 and 3 and an end portion 23 shown in FIG. On the other hand, the cylindrical molded body 40 does not have a joint portion extending in the longitudinal direction. Therefore, when the coating layer 20 is comprised from the cylindrical molded object 40, the heat insulation of this heat insulating material 1 can be made especially excellent.

  The material forming the cylindrical molded body 40 is not particularly limited as long as it is a porous material that can form the coating layer 20 having appropriate flexibility and strength. For example, the porous molded body 40 is porous as in the above-described coating sheet. A resin that is made porous by a stretching method can be preferably used. As the stretched resin, any of those made porous by the uniaxial stretching method and those made porous by the biaxial stretching method can be used.

  More specifically, as the stretched resin, for example, a fluororesin such as stretched PTFE or a polyolefin resin such as polyethylene or polypropylene that is made porous by a stretching method can be used. Especially, the heat resistance and heat insulation of the coating layer 20 which consists of the said cylindrical molded object 40 can be effectively improved by forming the cylindrical molded object 40 using expanded PTFE.

  Moreover, the thickness of the cylindrical molded object 40 can be made into the range of 10-2000 micrometers, for example, Preferably it can be set as the range of 30-1000 micrometers, More preferably, it is set as the range of 50-800 micrometers. it can.

  The tubular molded body 40 can be manufactured, for example, by winding a porous resin sheet around the outer periphery of the core material and integrating the porous resin sheet laminated on the outer periphery of the core material by heating. That is, for example, when manufacturing a cylindrical molded body 40 having a predetermined inner diameter and a predetermined thickness as shown in FIG. 6, first, a cylindrical core material having an outer diameter substantially the same as the predetermined inner diameter is used. A porous resin sheet thinner than the predetermined thickness is wound around the outer periphery a plurality of times, and a plurality of layers of the porous resin sheet are laminated on the outer periphery of the cylindrical core material. The porous resin layer is formed. Next, by heating the porous resin layer, the adhesion surface of the laminated porous resin sheets is melted, and a plurality of porous resin sheets laminated in the radial direction are fused together. In this way, it is possible to obtain a tubular molded body 40 in which a plurality of layers of porous resin sheets are integrally formed by heat sealing. In addition, the cylindrical molded object 40 which has the same or similar porosity as the porosity of a porous resin sheet can be obtained by setting the conditions of heat sealing | fusion appropriately.

  In the case where the coating layer 20 is composed of the tubular molded body 40, the heat insulating material 1 can be formed by inserting the heat insulating layer 10 into the tubular molded body 40. That is, in this case, the heat insulating layer 10 and the heat insulating layer are inserted into the cylindrical formed body 40 by inserting the heat insulating layer 10 made of the nanoparticle compression molded body or the fibrous body filled with the airgel. The heat insulating material 1 having the covering layer 20 made of the tubular molded body 40 covering the cover 10 is manufactured.

  In addition, the heat insulating material 1 can further include a porous second covering layer that covers the heat insulating layer 10. In this case, the covering layer 20 made of the tubular molded body 40 covers the heat insulating layer 10 covered with the second covering layer. Such a heat insulating material 1 can be manufactured by inserting the heat insulating layer 10 previously coated with the porous second covering layer into the tubular molded body 40.

  The second coating layer is made of a porous material like the coating layer 20 constituting the outermost layer described above, and is preferably formed of a porous resin such as a fluorine-based resin such as expanded PTFE. The second coating layer can be formed from the same or different material as the coating layer 20. That is, for example, both the coating layer 20 and the second coating layer can be formed from a fluororesin sheet (particularly an expanded PTFE sheet).

  Further, the total of the thickness of the second coating layer and the thickness of the coating layer 20 is preferably in the range of 10 to 2000 μm, more preferably in the range of 30 to 1000 μm, as described above. A range of 50 to 800 μm is particularly preferable. In this range, the thickness of the second coating layer and the thickness of the coating layer 20 can be arbitrarily set. That is, for example, the strength of the heat insulating material 1 can be effectively ensured by reducing the thickness of the second coating layer as much as possible and sufficiently securing the thickness of the coating layer 20 constituting the outermost layer. Can do. Specifically, for example, it is preferable to set these thicknesses so that the thickness of the coating layer 20 is equal to or greater than the thickness of the second coating layer.

  FIG. 7 is an explanatory view showing main steps included in an example of a method for manufacturing the heat insulating material 1 having the coating layer 20 made of the tubular molded body 40 (hereinafter referred to as “the present manufacturing method”). FIG. 8 is a plan view of an example of the heat insulating material 1 manufactured by the manufacturing method. FIG. 9 is a cross-sectional view of the heat insulating material 1 cut along the line IX-IX shown in FIG. FIG. 10 is a cross-sectional view of the heat insulating material 1 cut along line XX shown in FIG.

  In this manufacturing method, first, as shown in FIG. 7A, a heat insulating layer 10 and a covering sheet 50 for forming a second covering layer 60 (see FIG. 7B) are prepared. In this example, the heat insulating layer 10 is formed in a sheet shape, and more specifically, in a belt shape extending in the longitudinal direction.

  Next, as shown in FIG. 7B, by wrapping the heat insulating layer 10 with the covering sheet 50, the heat insulating layer 10 and the second covering layer 60 made of the covering sheet 50 covering the heat insulating layer 10, To form a complex having Here, an example is shown in which a composite is formed by folding one covering sheet 50 and wrapping the belt-shaped heat insulating layer 10.

  Here, the covering sheet 50 may have an adhesive layer formed on all or part of the surface in contact with the heat insulating layer 10. In this case, the adhesive layer can be, for example, an adhesive layer formed by applying an adhesive to the surface of the covering sheet 50. When the covering sheet 50 has an adhesive layer, the heat insulating layer 10 and the second covering layer 60 can be reliably integrated.

  Moreover, you may adhere | attach all or one part of the edge part of the said sheet | seat 50 for covering by heat welding or a stitch | suture as mentioned above irrespective of whether the sheet | seat 50 for coating | cover has an adhesive layer. Moreover, if the heat insulation layer 10 can be covered only by folding the covering sheet 50, an adhesive treatment such as heat welding or stitching is unnecessary.

  Next, as shown in FIG. 7C, the heat insulating layer 10 that has been previously coated with the second coating layer 60 as described above is inserted into the tubular molded body 40. That is, in the example shown in FIG. 7C, the belt-shaped heat insulating layer 10 is inserted in the longitudinal direction (the direction indicated by the arrow X shown in FIG. 7C) from one opening of the tubular molded body 40.

  The cylindrical molded body 40 shown in FIG. 7C has a cylindrical shape with a square cross section, but the cylindrical molded body 40 may have a circular cross section as shown in FIG. That is, since the cylindrical molded body 40 is excellent in flexibility due to the porosity, it can be easily deformed into a shape corresponding to the outer shape of the heat insulating layer 10 when the heat insulating layer 10 is inserted. Specifically, for example, the cylindrical shaped molded body 40 as shown in FIG. 6 can be deformed as shown in FIG. 7C by crushing it in the radial direction. In addition, when the heat insulating layer 10, the second covering layer 60, and the covering layer 20 are simply and reliably integrated and the heat insulating material 1 having excellent heat insulating properties is manufactured, the inner peripheral length of the tubular molded body 40 is The outer peripheral length of the second covering layer 60 that covers the heat insulating layer 10 is preferably substantially the same.

  In this example, since the heat insulating layer 10 is covered with the second covering layer 60 prior to the insertion into the tubular molded body 40, the heat insulating layer 10 is inserted into the tubular molded body 40. It can be done smoothly. That is, for example, when both the cylindrical molded body 40 and the covering sheet 50 are made of a fluorine-based resin such as expanded PTFE, it occurs between the cylindrical molded body 40 and the second coating layer 60. Since the frictional force can be effectively reduced, the belt-like heat insulating layer 10 can be easily and reliably inserted in the longitudinal direction of the tubular molded body 40. Furthermore, when the covering sheet 50 has the adhesive layer as described above, the integrity of the heat insulating layer 10 and the second covering layer 60 can be effectively maintained even after insertion.

  And as shown to FIG. 7D, the strip | belt-shaped this heat insulating material 1 is obtained by sealing the edge part of the longitudinal direction of the cylindrical molded object 40 in which the heat insulation layer 10 was inserted. This sealing can be performed, for example, by adhering the ends of the overlapped tubular molded body 40 by heat welding or stitching as in the case of the above-described covering sheet. In addition, among the longitudinal direction both ends of the cylindrical molded body 40, the end (opening) opposite to the side where the heat insulating layer 10 is inserted may be sealed before insertion.

  As shown in FIGS. 7D, 8, 9, and 10, the heat insulating material 1 manufactured in this way includes a heat insulating layer 10, a second covering layer 60 that covers the heat insulating layer 10, and the heat insulating layer 10. And the coating layer 20 which coat | covers the 2nd coating layer 60 will be included. In addition, the heat insulating material 1 has end portions 24 a and 24 b formed by sealing the longitudinal ends of the tubular molded body 40 at the longitudinal ends of the coating layer 20.

  This heat insulating material 1 manufactured by this manufacturing method will be excellent in heat insulation and workability. That is, as in the example shown in FIGS. 2 to 4 described above, when the covering layer 20 is formed from a covering sheet, the strip-shaped heat insulating material 1 is formed from the end of the covering sheet in the longitudinal direction. Thus, it has adhesive portions (the outer peripheral portions 21a and 22a shown in FIGS. 2 and 3 and the end portion 23 shown in FIG. 4) that do not include the heat insulating layer 10 inside.

  On the other hand, when the coating layer 20 is formed from the tubular molded body 40, the heat insulating material 1 has end portions 24a and 24b at both ends in the longitudinal direction, as shown in FIGS. 7D and 8 to 10. However, it does not have an adhesive portion extending in the longitudinal direction. Therefore, the heat insulation fall resulting from such an adhesion part can be suppressed effectively. That is, the present heat insulating material 1 having the covering layer 20 formed from the tubular molded body 40 surely has excellent heat insulating properties as compared with the case where the covering layer 20 formed from the covering sheet is provided. it can.

  Moreover, the workability of this heat insulating material 1 can also be improved by forming the coating layer 20 from the cylindrical molded body 40. That is, for example, when the belt-shaped heat insulating material 1 is spirally wound around the outer periphery of a pipe having a predetermined length, the heat insulating material 1 does not have an adhesive portion extending in the longitudinal direction. Can be installed easily without gaps.

  Moreover, this heat insulating material 1 which has the 2nd coating layer 60 can be made into the thing excellent in the low dust generation property. That is, in this case, the heat insulating material 1 includes the second covering layer 60 that covers the heat insulating layer 10 in addition to the covering layer 20 that constitutes the outermost layer, thereby allowing leakage of dust generated from the heat insulating layer 10. Can be more effectively suppressed.

  In addition, this heat insulating material 1 is not restricted to the case where the coating layer 20 consists of the cylindrical molded object 40, For example, even when the coating layer 20 consists of a sheet | seat for coating, it has the 2nd coating layer 60. Can do. FIG. 11 is a plan view of an example of the heat insulating material 1 in this case. FIG. 12 is a cross-sectional view of the heat insulating material 1 cut along the line XII-XII shown in FIG.

  In this heat insulating material 1 according to the example shown in FIGS. 11 and 12, the heat insulating layer 10 previously covered with the second covering layer 60 is inserted into a cylindrical bag formed by adhering the end portions of the covering sheet. Can be manufactured. That is, in this case, for example, first, the covering sheet is folded and the overlapped end portions extending in the longitudinal direction are bonded to form a cylindrical bag having both ends or one end opened in the longitudinal direction. Next, as in the case of using the above-described cylindrical molded body 40 (see FIG. 7C), the heat insulating layer 10 covered with the second covering layer 60 is longitudinally extended from one opening of the bag made of the covering sheet. Insert into. And this heat insulating material 1 is obtained by sealing the longitudinal direction both ends of a bag. As shown in FIGS. 11 and 12, the heat insulating material 1 manufactured in this manner is an end portion that is an adhesive portion extending in the longitudinal direction in addition to the end portions 24 a and 24 b formed at both ends in the longitudinal direction. 25.

  Since the heat insulating material 1 includes the heat insulating layer 10 and the coating layer 20 as described above, the heat insulating material 1 can be thinned while effectively maintaining the heat insulating property. That is, since the heat insulating layer 10 is composed of a nanoparticle compression-molded body or airgel fiber body excellent in heat insulating properties, the present heat insulating material 1 has a thickness reduced from that of a conventional heat insulating material, while the conventional heat insulating material 1 is reduced in thickness. A heat insulating property equivalent to or higher than that of the heat insulating material can be exhibited.

  Moreover, this heat insulating material 1 can have flexibility, heat resistance, and low dust generation in addition to excellent heat insulation. Here, the especially preferable aspect of this heat insulating material 1 is demonstrated.

  The heat insulating material 1 according to the first example of the preferred embodiment has a heat insulating layer 10 made of a compression-molded body of dry silica and a coating layer 20 made of a stretched PTFE sheet or a tubular shaped body 40 of stretched PTFE. The compression molded body further contains dispersed fibers and does not contain a binder.

  Dry silica is a single nanoparticle of hydrophilic or hydrophobic fumed silica. The fibers contained in the compression molded body are chopped glass fibers or aramid short fibers.

This compression molded body is a molded body mainly composed of dry silica to which fibers are added. That is, this compression-molded body contains dry silica in the range of 80 to 95% by weight and fibers in the range of 5 to 20% by weight. The compression-molded body is in the form of a sheet having a thickness in the range of 1 to 3 mm, the density is in the range of 150 to 250 kg / m ³ , and the thermal conductivity at 25 ° C. is 0.015 to 0.018 W / m ·. K range.

  On the other hand, the expanded PTFE sheet or cylindrical molded body 40 constituting the coating layer 20 has an average pore diameter in the range of 0.1 to 0.45 μm, a thickness in the range of 50 to 100 μm, and a thermal conductivity at 25 ° C. Is in the range of 0.03 to 0.04 W / m · K.

  And this heat insulation material 1 which has these heat insulation layers 10 and the coating layer 20 is the range whose thermal conductivity in 25 degreeC is 0.017-0.020 W / m * K, and has the outstanding heat insulation. . Furthermore, this heat insulating material 1 has the outstanding flexibility which can be constructed | assembled along the outer periphery of thin piping of the range whose outer diameter is 6-25 mm, for example, maintaining this heat insulation. Moreover, this heat insulating material 1 has the outstanding heat resistance which can be used at 0 to 250 degreeC. Moreover, since the heat insulation layer 10 is covered with the covering layer 20 which is the bag of the expanded PTFE sheet or the tubular molded body 40, the dust generation property of the heat insulation material 1 is remarkably reduced. In particular, when the covering layer 20 is made of the cylindrical molded body 40, as described above, there is no adhesive portion extending in the longitudinal direction, so that the thermal conductivity of the heat insulating material 1 is higher than that in the case of having the adhesive portion. It can be effectively reduced to achieve excellent heat insulation, and dust generation originating from the bonded portion can be reliably avoided.

  The heat insulating material 1 according to the second example of the preferred embodiment has a heat insulating layer 10 made of an airgel fiber body and a coating layer 20 made of a stretched PTFE sheet or a tubular molded body 40 of stretched PTFE, and a binder. Does not contain. This airgel fiber body is configured by filling a nonwoven fabric (fiber substrate) of PET fiber with silica airgel.

The airgel fiber body is a sheet having a thickness of 2 to 6 mm, a density of 100 to 200 kg / m ³ , and a thermal conductivity at 25 ° C. of 0.012 to 0.020 W / m · K. Range.

  On the other hand, the expanded PTFE sheet or cylindrical molded body 40 constituting the coating layer 20 has an average pore diameter in the range of 0.1 to 0.45 μm, a thickness in the range of 50 to 100 μm, and a thermal conductivity at 25 ° C. Is in the range of 0.03 to 0.04 W / m · K.

  And this heat insulation material 1 which has these heat insulation layers 10 and coating layers 20 is the range whose thermal conductivity in 25 degreeC is 0.015-0.018 W / m * K, and has the outstanding heat insulation. . Furthermore, this heat insulating material 1 has the outstanding flexibility which can be constructed | assembled along the outer periphery of thin piping of the range whose outer diameter is 6-25 mm, for example, maintaining this heat insulation. Moreover, this heat insulating material 1 has the outstanding heat resistance which can be used at 0-250 degreeC. Moreover, since the heat insulation layer 10 is covered with the covering layer 20 which is the bag of the expanded PTFE sheet or the tubular molded body 40, the dust generation property of the heat insulation material 1 is remarkably reduced. In particular, when the coating layer 20 is made of the tubular molded body 40, the heat insulating property and the low dust generation property of the heat insulating material 1 can be effectively enhanced as in the first example described above.

  Thus, this heat insulating material 1 has the outstanding flexibility which can maintain the said heat insulation, without tearing, when it deform | transforms in addition to the outstanding heat insulation. In this regard, when the heat insulating material 1 is deformed, the flexibility of the heat insulating material 1 is enhanced by allowing air to quickly enter and exit through the holes formed in the coating layer 20.

  In addition, as described above, the surface of the structure that is subject to heat insulation of the heat insulating material 1 having the coating layer 20 composed of the non-porous coating sheet 21 and the porous coating sheet 22. In the case of construction, the portion composed of the porous covering sheet 22 is arranged so as to be on the surface side of the structure. That is, for example, when the heat insulating material 1 is applied to the outer periphery of a pipe that transports a heated fluid having a relatively small outer diameter, the insulating layer 1 is composed of a porous covering sheet 22 in the covering layer 20. The portion formed by the non-porous covering sheet 21 is disposed on the radially outer side.

  Thereby, while utilizing the flexibility of this heat insulating material 1, the said heat insulating material 1 can be appropriately wound around the outer periphery of piping, and the dust generation from the said heat insulating material 1 after construction is very effective. Can be prevented.

  The heat insulating material 1 having such excellent characteristics can be preferably used as, for example, a heat insulating material applied to a semiconductor, liquid crystal, or electronic component manufacturing apparatus. In particular, with the recent miniaturization of these manufacturing apparatuses, for example, the outer diameter of piping connected to the manufacturing apparatus for transporting a heated fluid is also reduced.

  In this respect, the present heat insulating material 1 can be appropriately constructed along the outer periphery of such a thin pipe due to its excellent flexibility, and in addition, it has excellent heat insulation and heat resistance. , Low dust generation can be maintained.

  FIG. 13 is a perspective view of an example of a heat insulating structure (hereinafter referred to as “main structure 2”) according to the present embodiment. As shown in FIG. 13, the present structure 2 includes a pipe 70 to be insulated and the main heat insulating material 1 wound around the outer periphery of the pipe 70 a plurality of times. In FIG. 13, for convenience of explanation, a part of the heat insulating material 1 covering the outer periphery of the pipe 70 is omitted, and the pipe 70 is exposed.

  The pipe 70 is, for example, a pipe of a semiconductor manufacturing apparatus for transporting a heated fluid. In the downsized semiconductor manufacturing apparatus, the outer diameter of the pipe 70 is in the range of 6 to 25 mm, for example. Moreover, the temperature of the piping 70 which this heat insulating material 1 contacts becomes the range of 150-200 degreeC, for example.

  One of the characteristic points in the present structure 2 is that the sheet-like heat insulating material 1 is constructed so as to overlap the outer periphery of such a thin pipe 70 a plurality of times, as shown in FIG. This is a point in which a multilayer heat insulating member in which the heat insulating material 1 is laminated is formed. As described above, the present structure 2 can be realized by allowing the heat insulating material 1 to be thin while maintaining high heat insulating properties and having excellent flexibility.

  FIG. 14 is a cross-sectional view of an example of the present structure 2. In the example shown in FIG. 14, this structure 2 is wound around the outer periphery of the pipe 70, the first main heat insulating material 1a wound around the outer periphery of the pipe 70, and the first main heat insulating material 1a. The second main heat insulating material 1b. That is, the first main heat insulating material 1a and the second main heat insulating material 1b are laminated on the outer periphery of the pipe 70 in the radial direction.

  The first main heat insulating material 1a and the second main heat insulating material 1b are formed with a first joint portion Ma and a second joint portion Mb, which are circumferential seams, respectively. Here, the first joint portion Ma and the second joint portion Mb are formed at positions shifted from each other in the circumferential direction. That is, the first joint portion Ma of the first main heat insulating material 1a is covered with the second main heat insulating material 2, more specifically, the first joint portion Ma and the second joint portion Mb. Are formed at positions facing each other across the pipe 70.

  As described above, when the plurality of layers of the heat insulating materials 1a and 1b are arranged on the outer periphery of the pipe 70, the joint portions Ma and Mb adjacent in the radial direction of the pipe 70 are formed at positions shifted from each other in the circumferential direction. Thus, by covering the joint portion Ma of the one main heat insulating material 1a with the other main heat insulating material 1b, it is possible to effectively suppress the deterioration of the heat insulating characteristics of the main structure 2 due to the plurality of joint portions Ma, Mb. it can.

  Moreover, this structure 2 can also be formed by winding the strip | belt-shaped this heat insulating material 1 around the outer periphery of the piping 70 helically. FIG. 15 is a plan view of an example of the present structure 2 in this case. 16 is a cross-sectional view of the present structure 2 taken along the line XVI-XVI shown in FIG. In addition, in FIG. 16, illustration is abbreviate | omitted about the internal structure of this heat insulating material 1. FIG.

  In the example shown in FIGS. 15 and 16, the present structure 2 includes a pipe 70 and the main heat insulating material 1 spirally wound around the outer periphery of the pipe 70. Here, this heat insulating material 1 has the edge part 25 extended in a longitudinal direction, as shown in the above-mentioned FIG.11 and FIG.12. For this reason, the edge part 25 will be arrange | positioned in the part in which a part of this heat insulating material 1 and another part overlap in the longitudinal direction of the piping 70. Since this end portion 25 is a joint portion that does not have the heat insulating layer 10 inside, it can be said that the end portion 25 is a portion having poor heat insulating properties in the heat insulating material 1.

  Therefore, in the example illustrated in FIGS. 15 and 16, the end portion 25 is disposed so as to overlap in the radial direction with respect to a part of the heat insulating material 1 adjacent to the end portion 25. Therefore, in this structure 2, the heat insulation fall by the edge part 25 can be suppressed effectively. Here, an example is shown in which the end portion 25 overlaps the outer side in the radial direction with respect to a part of the adjacent main heat insulating material 1, but the present invention is not limited thereto, and the end portion 25 is adjacent to the main main heat insulating material. You may arrange | position so that it may overlap with radial direction inner side with respect to a part of material 1. FIG. That is, in this case, the end portion 25 is disposed between a part of the adjacent heat insulating material 1 and the outer periphery of the pipe 70.

  Next, specific examples of the heat insulating material 1 will be described.

In Example 1, the flexibility and heat insulating properties of the heat insulating layer 10 were evaluated. As the heat insulation layer 10, first, a compression molded body containing hydrophilic fumed silica (Fumed Silica AEROSIL 300, Nippon Aerosil Co., Ltd.) and chopped glass fibers (CS6J-888, Nitto Boseki Co., Ltd.) was produced. That is, first, a mixed powder containing 90% by weight of hydrophilic fumed silica and 10% by weight of chopped glass fibers was prepared. Then, 2.1 g, 4.5 g, 6.0 g, 7.5 g, or 9.0 g of the mixed powder was spread in a 100 mm × 150 mm × 2 mm mold and compression molded. At this time, by adjusting the compression conditions, five types of compression-molded bodies having a density of 70 kg / m ³ , 150 kg / m ³ , 200 kg / m ³ , 250 kg / m ³ or 300 kg / m ³ (heat insulating layers A1 to A1) A5) was produced.

Similarly, it contains 90% by weight of hydrophobic fumed silica (AEROSIL R974, Nippon Aerosil Co., Ltd.) and 10% by weight of chopped glass fiber (CS6J-888, Nittobo Co., Ltd.), and has a density of 70 kg. A compression molded body (heat insulation layer B) of / m ³ was produced.

  The average particle diameter of hydrophilic fumed silica was 9 nm, the average particle diameter of hydrophobic fumed silica was 9 nm, the average diameter of chopped glass fibers was 11 μm, and the average length was 6 mm.

Further, as the heat insulating layer 10, an airgel fiber body (SPACEELFT2200, Aspen Aerogels Inc.) (heat insulating layer C1) having a density of 130 kg / m ^3, which is formed by filling a non-woven fabric of PET fiber with silica airgel, and a non-woven fabric of carbon fiber. An airgel fiber body (SPACEELFT2250, Aspen Aerogels Inc.) (heat insulation layer C2) having a density of 170 kg / m ³ , which is filled with silica airgel, was prepared. In addition, all of these eight types of heat insulation layers A1 to A5, B, C1, and C2 had a thickness of 2 mm.

  And about each of these 8 types of heat insulation layers A1-A5, B, C1, C2, while evaluating the flexibility, the thermal conductivity in 25 degreeC and 80 degreeC was measured. Flexibility was evaluated by wrapping each heat insulating layer around the outer periphery of a pipe having an outer diameter of 15 mm and observing the appearance of each wound heat insulating layer.

  The thermal conductivity was measured by a heat flow meter method based on a predetermined standard (JIS-A1412, ASTM-C518, ISO8301) using a thermal conductivity measuring device (HC-110, Eihiro Seiki Co., Ltd.). For measurement of thermal conductivity, a test body in which each heat insulating layer was formed into a disk shape having a diameter of 60 mm was used.

FIG. 17 shows the evaluation results of density (kg / m ³ ) and flexibility, thermal conductivity (W / m · K) at 25 ° C. for each of the eight types of heat insulating layers A1 to A5, B, C1, and C2. The thermal conductivity (W / m · K) at 80 ° C. is shown respectively.

  In FIG. 17, the flexibility indicates a result of evaluation in four stages of “+”, “++”, “++++”, and “++++”. The heat-insulating layers A1 and B with the most excellent evaluation “++++” obtained no wrinkle formation even when applied to the pipe, and could be placed in close contact with the outer periphery of the pipe. In the heat insulating layers A2 and C1 obtained with the evaluation “++++”, a slight wrinkle was observed in a state where the heat insulating layers A2 and C1 were applied to the pipe. However, the heat insulating layers A2 and C1 could be arranged well along the outer periphery of the pipe. The heat insulation layers A3, A4, and C2 obtained with the evaluation “++” were wrinkled in a state where they were applied to the pipe, but had flexibility that can be arranged along the outer periphery of the pipe. It was. The heat insulating layer A5 obtained with the evaluation “+” had high rigidity, and could not be disposed along the outer periphery of the pipe.

  Moreover, as shown in FIG. 17, all the heat insulation layers had the heat conductivity in 25 degreeC below 0.030 W / m * K, and had the outstanding heat insulation. Among them, the heat insulating layers A2, A3, A4, A5, C1, and C2 have a thermal conductivity at 25 ° C. of 0.020 W / m · K or less and a thermal conductivity at 80 ° C. of 0.025 W / m · K or less. In particular, it had excellent heat insulation.

Thus, among the five heat insulation layers A1 to A5 which are compression molded bodies of hydrophilic fumed silica, the three heat insulation layers A2, A3 and A4 whose density is adjusted to the range of 150 to 250 kg / m ³ are: It had excellent heat insulation and flexibility. Further, the two heat insulating layers C1 and C2 which are airgel fiber bodies have both excellent heat insulating properties and flexibility, and in particular, the heat insulating layer C1 having a PET fiber base material has heat insulating properties and flexibility. Both were better.

  Further, the heat insulating layer B, which is a compression molded body of hydrophobic fumed silica, has a thermal conductivity at 25 ° C. and 80 ° C., compared to the heat insulating layer A1, which is a compression molded body of hydrophilic fumed silica having the same density. It was low. This was considered to be a result of the hydrophobic fumed silica being less hygroscopic than the hydrophilic fumed silica.

  In Example 2, the flexibility and heat insulating properties of the coating layer 20 were evaluated. The covering layer 20 includes an expanded PTFE sheet (Soft Seal, NICHIAS Corporation) (covering layer D1) having a thickness of 0.60 mm, and an expanded PTFE sheet (Poreflon WP020-80, Sumitomo) having a thickness of 0.08 mm. (Electric Industry Co., Ltd.) (covering layer D2), glass cloth (woven glass fiber) having a thickness of 0.90 mm (Marintex cloth, NICHIAS Corporation) (covering layer E1), and a thickness of 1. A glass cloth (fluorine-impregnated glass cloth, Nichias Co., Ltd.) (covering layer E2) having a fluorine coating of 00 mm was prepared. And about each of these four types of coating layers D1, D2, E1, and E2, while evaluating the flexibility similarly to the above-mentioned Example 1, the thermal conductivity in 25 degreeC was measured.

  FIG. 18 shows the thickness (mm), flexibility evaluation results, and thermal conductivity (W / m · K) at 25 ° C. for each of the four types of coating layers D1, D2, E1, and E2. As shown in FIG. 18, all the coating layers were excellent in flexibility, and in particular, the extremely thin coating layer D2 had particularly excellent flexibility. In addition, the coating layers D1 and D2 that are expanded PTFE sheets had significantly lower thermal conductivity than the coating layers E1 and E2 that were glass cloth, and had excellent heat insulation properties.

  In Example 3, the heat insulating property and dust generation property of the heat insulating material 1 having the heat insulating layer 10 and the coating layer 20 were evaluated.

  As this heat insulating material 1, six types of heat insulating materials having two types of heat insulating layers A3 or C1 manufactured in Example 1 and three types of coating layers D1, D2, E1 in different combinations. F1 to F6 were produced. Specifically, the heat insulating material F1 including the heat insulating layer C1 and the covering layer E1, the heat insulating material F2 including the heat insulating layer A3 and the covering layer E1, the heat insulating material F3 including the heat insulating layer C1 and the covering layer D1, the heat insulating layer A3 and the covering layer. A heat insulating material F4 made of D1, a heat insulating material F5 made of a heat insulating layer C1 and a covering layer D2, and a heat insulating material F6 made of a heat insulating layer A3 and a covering layer D2 were produced.

  In addition, when using the coating layers D1 and D2 made of an expanded PTFE sheet, the outer peripheral portions of the coating layers D1 and D2 are sealed by thermal welding, and when the coating layer E1 made of glass cloth is used, The outer peripheral portion of the coating layer E1 was sealed by stitching with a glass thread.

  And about each of these six types of heat insulating materials F1-F6, the thermal conductivity in 25 degreeC and 80 degreeC was measured similarly to the above-mentioned Example 1. FIG. In addition, dust generation was evaluated for each of the six types of heat insulating materials F1 to F6.

  In the evaluation of dust generation, first, a vibrating device (BALL VIBRATORS, Exen Corporation) equipped with a sample table that can be vibrated in a clean chamber with a predetermined volume and a particle counter (KC-22B, Ontec Corporation). ) And were installed.

  And any one of 6 types of heat insulating materials F1-F6 was mounted in the sample stand of the vibration apparatus, and the vibration of the sample stand was then started. Next, after the sample stage was vibrated for 1 minute, the vibration was stopped, and the number of fine particles generated in the chamber was measured by a particle counter for 1 minute. As a comparative example, the number of fine particles was similarly measured without placing anything on the sample stage.

  FIG. 19 shows the thermal conductivity (W / m · K) at 25 ° C. and the thermal conductivity (W / m · K) at 80 ° C. for each of the six types of heat insulating materials F1 to F6. As shown in FIG. 19, the two types of heat insulating materials F1 and F2 each having the coating layer E1 made of glass cloth have a thermal conductivity at 25 ° C. of 0.025 W / m · K or less and a thermal conductivity at 80 ° C. Was 0.030 W / m · K or less, and had excellent heat insulating properties. Further, the four types of heat insulating materials F3 to F6 having the coating layers D1 and D2 made of the expanded PTFE sheet all have a thermal conductivity at 25 ° C. of 0.020 W / m · K or less, and a thermal conductivity at 80 ° C. of 0. It was 0.025 W / m · K or less, and had particularly excellent heat insulating properties.

  20, 21, and 22 show the evaluation results of dust generation. FIG. 20 shows the results for the two types of heat insulating materials F1 and F2 having the coating layer E1 and the comparative example, and FIG. 21 shows the results for the two types of heat insulating materials F3 and F4 having the coating layer D1 and the comparative example. FIG. 22 shows the results for two types of heat insulating materials F5 and F6 having a coating layer D2 and a comparative example.

20 to 22, the horizontal axis indicates the size (diameter) of the measured fine particles, and the vertical axis indicates the number of fine particles of each size (individual / 300 cm ³ ) measured in 300 cm ³ of air in the chamber. ). Moreover, in FIG. 20 to FIG. 22, the white bar graph shows the result of the comparative example, and the black bar graph shows the result of the heat insulating materials F1, F3, and F5 having the heat insulating layer C1 that is an airgel fiber body, and hatching is performed. The attached bar graph shows the results of the heat insulating materials F2, F4 and F6 having the heat insulating layer A3 which is a compression molded body of hydrophilic fumed silica.

  As shown in FIG. 20, with respect to the two types of heat insulating materials F1 and F2 having the coating layer E1 made of glass cloth, fine particles having a size that is not detected in the comparative example are detected, and the number of detected fine particles of each size is detected. Was greater than that of the comparative example. Moreover, the number of the microparticles | fine-particles detected about the heat insulating material F1 which has the heat insulation layer C1 which consists of airgel fiber bodies was more than that of the heat insulating material F2 which has the heat insulation layer A3 which consists of compression moldings.

  As shown in FIG. 21, for the two types of heat insulating materials F3 and F4 having the coating layer D1 made of expanded PTFE having a thickness of 0.60 mm, the number of measured fine particles was comparable to that of the comparative example. . That is, it was confirmed that these heat insulating materials F3 and F4 have extremely low dust generation.

  As shown in FIG. 22, the number of fine particles measured for the heat insulating material F5 having the coating layer D2 made of expanded PTFE having a thickness of 0.08 mm and the heat insulating layer C1 made of an airgel fiber is about the same as the comparative example. Met. Moreover, the number of fine particles measured about the heat insulating material F6 which has the coating layer D2 and the heat insulation layer A3 which consists of a compression molding body was slightly larger than the comparative example. However, with respect to this heat insulating material F6, fine particles having a size not detected in the comparative example were not detected at all. That is, it was confirmed that these heat insulating materials F5 and F6 have extremely low dust generation.

  Thus, the heat insulating materials F3 to F6 having the heat insulating layer C1 made of an airgel fiber body or the heat insulating layer A3 made of a compression molded body of hydrophilic fumed silica, and the coating layers D1 and D2 made of an expanded PTFE sheet, All of them had excellent heat insulating properties and low dust generation.

  In Example 4, the influence which the presence or absence and arrangement position of the radiation reflection layer 30 have on the heat insulating property of the heat insulating material was evaluated. As the heat insulating material, as shown in FIG. 5C described above, the heat insulating material having the laminated first heat insulating layer 10a and second heat insulating layer 10b and the covering layer 20 covering the heat insulating layers 10a and 10b is used. used.

As each of the heat insulation layers 10a and 10b, an airgel fiber body (Pyrogel 3350, Aspen Aerogels Inc.) having a density of 130 kg / m ³ and a thickness of 3 mm, in which a non-woven fabric of carbon fiber is filled with silica airgel, was used. As the coating layer 20, an expanded PTFE sheet (soft seal, NICHIAS Corporation) having a thickness of 0.60 mm was used. As the radiation reflection layer 30, an aluminum foil (Toyo Aluminum Co., Ltd.) having a thickness of 15 μm was used.

  And in the 1st example, heat insulating material G1 which has the 1st heat insulation layer 10a, the 2nd heat insulation layer 10b, and the coating layer 20, and does not have the radiation reflection layer 30 was manufactured. In the second example, the heat insulating material in which the radiation reflecting layer 30 is provided on the outer surface of the first heat insulating layer 10a (the surface opposite to the surface in contact with the second heat insulating layer 10b) in the heat insulating material G1. G2 was produced. In the third example, the heat insulating material G3 (having a structure shown in FIG. 5C) in which the radiation reflecting layer 30 is provided between the first heat insulating layer 10a and the second heat insulating layer 10b in the heat insulating material G1. Insulation material) was manufactured. In the fourth example, the heat insulating material in which the radiation reflecting layer 30 is provided on the outer surface of the second heat insulating layer 10b (the surface opposite to the surface in contact with the first heat insulating layer 10a) in the heat insulating material G1. G4 was produced.

  And about each heat insulating material G1-G4, the heat conductivity in 25 degreeC, 80 degreeC, and 100 degreeC was measured similarly to the above-mentioned Example 1. FIG. In the measurement of thermal conductivity, a heat source was disposed on the first heat insulating layer 10a side of each of the heat insulating materials G1 to G4. That is, the heat insulating material G2 according to the second example has the radiation reflection layer 30 on the heat source side of the heat insulating layers 10a and 10b, and the heat insulating material G4 according to the fourth example is opposite to the heat source of the heat insulating layers 10a and 10b. The radiation reflecting layer 30 is provided on the side.

  FIG. 23 shows the measurement results of thermal conductivity (W / m · K) at 25 ° C., 80 ° C., and 100 ° C. for each of the four types of heat insulating materials G1 to G4. As shown in FIG. 23, the thermal conductivity of the three types of heat insulating materials G2 to G4 having the radiation reflecting layer 30 was reduced as compared with that of the heat insulating material G1 not having the radiation reflecting layer 30. In particular, the heat conductivity of the heat insulating material G2 having the radiation heat insulating layer 30 on the heat source side was low.

  That is, the heat insulating property was improved by providing the radiation reflection layer 30. Moreover, the improvement of the heat insulating property was particularly remarkable when the radiation heat insulating layer 30 was disposed on the heat source side. That is, it was shown that it is preferable to arrange the radiation reflection layer 30 at a position close to the heat source.

  In Example 5, the influence which the material which comprises the radiation reflection layer 30 has on the heat insulation of a heat insulating material was evaluated. As shown in FIG. 5A, the heat insulating material includes a heat insulating layer 10, a radiation reflecting layer 30 formed on one surface of the heat insulating layer 10, and a covering layer that covers the heat insulating layer 10 and the radiation reflecting layer 30. 20 were used.

As the heat insulating layer 10, an airgel fiber body (Pyrogel 3350, Aspen Aerogels Inc.) having a density of 130 kg / m ³ and a thickness of 3 mm, in which a carbon fiber nonwoven fabric is filled with silica airgel, was used. As the coating layer 20, an expanded PTFE sheet (soft seal, NICHIAS Corporation) having a thickness of 0.60 mm was used.

  As the radiation reflecting layer 30, an aluminum foil (Toyo Aluminum Co., Ltd.) having a thickness of 15 μm, a silver / aluminum foil in which a silver thin film is formed on the surface of the aluminum foil by vapor deposition, and a gold thin film on the surface of the aluminum foil by vapor deposition. Either of the gold / aluminum foils formed was used.

  That is, a heat insulating material H1 having no radiation reflecting layer 30, a heat insulating material H2 having a radiation reflecting layer 30 made of an aluminum foil, and a heat insulating material H3 having a radiation reflecting layer 30 made of an aluminum foil on which a silver thin film having a thickness of 100 nm is formed. A heat insulating material H4 having a radiation reflecting layer 30 made of an aluminum foil on which a silver thin film having a thickness of 200 nm is formed, a heat insulating material H5 having a radiation reflecting layer 30 made of an aluminum foil on which a silver thin film having a thickness of 300 nm is formed, and A heat insulating material H6 having a radiation reflection layer 30 made of an aluminum foil on which a gold thin film having a thickness of 300 nm was formed was manufactured.

  And about each heat insulating material H1-H6, similarly to the above-mentioned Example 1, the heat conductivity in 25 degreeC, 80 degreeC, and 100 degreeC was measured. In the measurement of thermal conductivity, a heat source was disposed on the radiation reflecting layer 30 side of each of the heat insulating materials H1 to H6.

  FIG. 24 shows the measurement results of thermal conductivity (W / m · K) at 25 ° C., 80 ° C., and 100 ° C. for each of the six types of heat insulating materials H1 to H6. As shown in FIG. 24, the thermal conductivity of the five types of heat insulating materials H <b> 2 to H <b> 6 having the radiation reflecting layer 30 was reduced as compared with that of the heat insulating material H <b> 1 not having the radiation reflecting layer 30. That is, the heat insulating property was improved by providing the radiation reflecting layer 30 made of any material.

  In Example 6, the influence of the presence and content of infrared reflective particles in the heat insulating layer 10 on the heat insulating properties of the heat insulating layer 10 was evaluated. As the infrared reflective particles, silicon carbide particles (Silcar-G14, Yamamoto Dye Chemical Co., Ltd.) were used.

  And as the heat insulation layer 10, hydrophilic fumed silica (Fumed Silica AEROSIL300, Nippon Aerosil Co., Ltd.), chopped glass fiber (CS6J-888, Nitto Boseki Co., Ltd.), and said infrared reflective particle | grains are contained. A compression molded body was used.

That is, heat insulating layer J1 containing 90% by weight of fumed silica and 10% by weight of glass fiber, heat insulating layer J2 containing 80% by weight of fumed silica, 10% by weight of glass fiber and 10% by weight of silicon carbide particles, fumed silica A heat insulating layer J3 containing 70% by weight, glass fiber 10% by weight and silicon carbide particles 20% by weight, fumed silica 60% by weight, glass fiber 10% by weight and silicon carbide particles 30% by weight are manufactured. did. All the heat insulating layers J1 to J4 had a density of 200 kg / m ³ .

  In addition, the compression molding body was manufactured by the compression molding of the mixed powder of hydrophilic fumed silica, chopped glass fiber, and infrared reflective particles similarly to the above-mentioned Example 1. And about each heat insulating material J1-J4, the heat conductivity in 25 degreeC, 80 degreeC, and 100 degreeC was measured similarly to the above-mentioned Example 1. FIG.

  FIG. 25 shows the measurement results of thermal conductivity (W / m · K) at 25 ° C., 80 ° C. and 100 ° C. for each of the four types of heat insulating materials J1 to J4. As shown in FIG. 25, at 80 ° C. and 100 ° C., the thermal conductivity of the three types of heat insulating materials J2 to J4 containing infrared reflective particles is higher than that of the heat insulating material J1 not containing the infrared reflective particles. Reduced. That is, heat insulation improved by containing infrared reflective particles.

  DESCRIPTION OF SYMBOLS 1 Heat insulating material, 2 Thermal insulation structure 10,10a, 10b Thermal insulation layer, 20 Coating layer, 21,22 Coating sheet, 21a, 22a Outer peripheral part, 23, 24a, 24b, 25 End part, 30, 30a, 30b Radiation reflection Layer, 40 cylindrical molded body, 41 hollow part, 50 covering sheet, 60 second covering layer, 70 piping.

Claims (10)

A compression molded article or Ranaru insulation layer of nanoparticles containing fiber material,
A porous coating layer comprising a fluororesin sheet made porous by a stretching method for coating the heat insulating layer;
A heat insulating material characterized by comprising: The heat insulating material according to claim 1, wherein the nanoparticles are dry silica or wet silica . The heat insulating material according to claim 1 , wherein the coating layer is made of a porous cylindrical molded body. It further has a porous second covering layer that covers the heat insulating layer, and the covering layer made of the cylindrical molded body covers the heat insulating layer covered with the second covering layer. The heat insulating material according to claim 3 . The heat insulating material according to claim 3 or 4 , wherein the heat insulating layer is inserted into the cylindrical molded body. The heat-insulating layer further has a laminated radiation reflecting layer, said coating layer, thermally insulating material, according to any one of claims 1 to 5, characterized in that for covering the heat insulating layer and the radiation reflecting layer. The heat insulating material according to any one of claims 1 to 6 , wherein the heat insulating layer contains an infrared reflecting agent or an infrared absorbing agent. Piping to be insulated,
The heat insulating material according to any one of claims 1 to 7 , wherein the heat insulating material is wound around the outer periphery of the pipe a plurality of times.
A heat insulating structure characterized by comprising: A porous cylindrical molded body made of a porous reduction has been fluororesin by stretching method, by inserting a compression molded article or Ranaru insulation layer of nanoparticles containing fiber material,
A method of manufacturing a heat insulating material, comprising: manufacturing a heat insulating material having the heat insulating layer and a covering layer made of the cylindrical molded body that covers the heat insulating layer. The said heat insulating material is manufactured by inserting the said heat insulating layer previously coat | covered with the porous 2nd coating layer in the said cylindrical molded object, The manufacture of the heat insulating material of Claim 9 characterized by the above-mentioned. Method.

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