JP2011005693A - Gas barrier laminated film for vacuum heat insulating material, and flame-retardant vacuum heat insulating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier laminated film for vacuum heat insulating materials and flame-retardant vacuum heat insulating materials that are suitably used for vehicles.SOLUTION: The gas barrier laminated film for vacuum heat insulating materials is provided by laminating, from the outermost layer to the innermost layer, at least a flame-retardant member layer, a gas barrier layer, and a thermally melt-sticking resin layer. The flame-retardant member layer is of one or more selected from flame-retardant substance carriers obtained by carrying a flame-retardant substance on flame resisting paper and natural cloth, or a paper base material. The film excels in flame retardant properties and bending aptitude, and is suitably used as a vacuum heat insulating material for vehicles such as automobiles, railway vehicles and ships.

Description

  The present invention relates to a gas barrier laminated film for a vacuum heat insulating material in which a flame retardant member is arranged in the outermost layer, and a flame retardant vacuum heat insulating material that is sealed under reduced pressure using the gas barrier laminated film for a vacuum heat insulating material, The present invention relates to a flame retardant vacuum heat insulating material that is excellent in flame retardancy and bending workability and can be suitably used for vehicles such as automobiles, ships, and railways.

  In recent years, reduction of greenhouse gases has been promoted in order to prevent global warming, and in order to achieve energy saving, efforts are being made to cut off heat transfer with a vacuum heat insulating material and reduce energy required for air conditioning. Such a vacuum heat insulating material can exhibit high heat insulating performance with a thickness of 10 mm or less, and has become an effective material used for transportation equipment such as railways, automobiles, and ships in order to widen indoor spaces. .

  However, when using a heat insulating material as a transportation equipment, the vacuum heat insulating material is required to have flame retardancy or non-flammability. Moreover, it is necessary to have the flexibility which can be closely_contact | adhered corresponding to the structure which has arbitrary curved surfaces.

  As a vacuum heat insulating material having such incombustibility or flame retardancy, a material using an aluminum foil as a jacket material of the vacuum heat insulating material is disclosed (Patent Document 1). From the viewpoint of weight reduction and pressure resistance improvement due to rationalization of production and higher speed, the double skin structure utilizing large hollow material made of light alloy or honeycomb structure material made of light alloy is adopted for the vehicle body. Since the skin structure has a large wall thickness, it is difficult to secure a wide interior space. In view of this, a thin heat insulating material that can be mounted between the structure and the lining for lining is provided so that a wide interior space can be secured even with such a double skin structure. In order to ensure the nonflammability of the heat insulating material, it is described that a thick aluminum foil or stainless steel foil of 50 μm or more is used for the outer cover material of the vacuum heat insulating material. In addition, as a core material of the vacuum heat insulating material, a flexible fiber material that does not cause local deformation and breakage with respect to the curved surface having the minimum radius of the structure of the railway vehicle is suitable. Illustrated.

  Further, the vacuum heat insulating material is a flexible vacuum heat insulating material which is arranged in a portion other than the window frame on the outer wall and inner wall of the railway vehicle body and the air conditioning duct portion and is bent according to the shape of the vehicle body from a flat plate shape. A vacuum heat insulating material in which at least one surface of the heat insulating material is covered with a flame retardant sheet material is also disclosed (Patent Document 2). In order to impart incombustibility to the vacuum heat insulating material, an aluminum foil of 50 μm or more is used for the outermost layer of the outer cover material of the vacuum heat insulating material. The flexibility of vacuum heat insulating material is improved by using the fiber which made the glass fiber into the sheet form as a core material, and thereby the application range of the vacuum heat insulating material can be taken as wide as possible in any place. In addition, it is possible to secure a large interior space for railway vehicles and railcars.

  Further, the gas barrier layer of the jacket material is made of a metal foil or a deposited resin film, the heat welding layer is a film having a melting point of 150 ° C. or more and 200 ° C. or less, and the outermost layer is a jacket material having a melting point of 200 ° C. or more. There is also a vacuum heat insulating material (Patent Document 3). In Patent Document 3, although the heat insulation performance can be sufficiently maintained over time when the use atmosphere is 100 ° C. or less like a refrigerator or an electric water heater, the use atmosphere of a copy machine, a printer, etc. is about 150 ° C. In view of the fact that it becomes difficult to maintain the heat insulating property, a vacuum heat insulating material capable of maintaining the heat insulating property even in a high temperature region is provided. For this reason, as the outermost layer of the jacket material, a film having a high or no melting point such as a fluorine-based film or an imide-based film is used to ensure a wide application temperature range. In addition, since the fluorine-based film or the imide-based film is excellent in flexibility, cracks are generated in the film at the bent portion of the fin even when the fin portion generated when the vacuum heat insulating material is manufactured and used at a high temperature. It is possible to prevent the occurrence of pinholes in the jacket material of the vacuum heat insulating material, which is triggered.

Japanese Patent Laid-Open No. 10-258736 JP 2006-117133 A JP 2005-1114013 A

  In Patent Document 1 and Patent Document 2, a metal foil such as a thick aluminum foil having a thickness of 50 μm or more is used for the jacket material in order to impart flame retardancy. However, although flame retardancy can be imparted by the aluminum foil, thermal cross-linking occurs from the front surface to the back surface of the vacuum heat insulating material due to the thermal conductivity of the metal foil, and the original heat insulating property that is a characteristic of the vacuum heat insulating material is exhibited. May be difficult.

  Further, for example, the vacuum heat insulating material described in Patent Document 2 is composed of a core material and a jacket material, the jacket material has at least a gas barrier layer and a heat-sealing layer, and aluminum is provided as the outermost layer of the jacket material. The film is used. Although the flexibility of the core material can be ensured by using glass wool or the like for the core material of the vacuum heat insulating material, the vacuum is substantially reduced if the flexibility of the jacket material covering the core material is not secured. The bending workability at the time of manufacturing a heat insulating material is not sufficient, and it becomes difficult to impart substantial flexibility as a vacuum heat insulating material.

  Moreover, the said patent document 3 uses the flame-retardant film of a fluorine-type film or an imide-type film instead of metal foil, and ensures the flame retardance and flexibility of a vacuum heat insulating material, Considering gas generation due to decomposition, a fluorine-based film has a risk of generating toxic hydrogen fluoride or carcinogenic tetrafluoroethylene during high-temperature decomposition. In addition, at a high temperature, the outer jacket material may melt or heat wraparound may occur, thereby impairing the original heat insulating property that is a characteristic of the vacuum heat insulating material.

  In particular, thermal insulation materials used for transportation equipment such as railways, automobiles, and ships are required to have high thermal insulation properties even if they are thin, and since the vehicle is a structure having an arbitrary curved surface, bending workability is also required. . In addition, assuming that a fire breaks out, it is required to be flame retardant, and in particular, the heat insulating material attached to the ceiling portion should not be melted and dripped by heat.

Then, an object of this invention is to provide the gas-barrier laminated | multilayer film for vacuum heat insulating materials which is excellent in a flame retardance and a bending workability.
Moreover, an object of this invention is to provide the flame-retardant vacuum heat insulating material formed by pressure-sealing with such a gas barrier laminated film for vacuum heat insulating materials.

Another object of the present invention is to provide a vehicle flame-retardant vacuum heat insulating material that can be suitably used for vehicles requiring bending workability such as railways, automobiles, and ships.
Moreover, an object of this invention is to provide the vehicle which arrange | positioned the said flame-retardant vacuum heat insulating material for vehicles.

  As a result of detailed examination of the outer jacket material of the vacuum heat insulating material, the present inventor has a gas barrier property formed by laminating a flame retardant member layer, a gas barrier layer, and a heat-fusible resin layer from the outermost layer toward the innermost layer. 1. A laminated film, wherein the outermost heat-fusible resin layer is selected from flame retardant paper and a flame retardant substance carrier formed by carrying a flame retardant substance on a natural fabric or paper substrate. It is possible to ensure the flame retardancy of the vacuum heat insulating material by constituting with more than one kind of flame retardant member, to ensure the bending workability by limiting the flame retardant member layer to a predetermined thickness, such a vacuum heat insulating material We have found that the vacuum heat insulating material made by sealing the core material with a gas barrier laminated film for use in the vacuum is not melted and dripped during heating, and is excellent in safety even when mounted on the ceiling of a vehicle, and the present invention is completed. I let you.

  That is, the present invention is a gas barrier laminated film for a vacuum heat insulating material comprising at least a flame retardant member layer, a gas barrier layer, and a heat-fusible resin layer laminated from the outermost layer to the innermost layer. The flame retardant member layer is one or more selected from a flame retardant paper and a flame retardant substance carrier formed by carrying a flame retardant substance on a natural fabric or a paper base material. A gas barrier laminated film for a material is provided.

Moreover, this invention provides the flame-retardant vacuum heat insulating material formed by pressure-sealing with the said gas barrier laminated film for vacuum heat insulating materials.
Moreover, this invention provides the flame retardant vacuum heat insulating material for vehicles which consists of the said flame retardant vacuum heat insulating material.

Moreover, the vehicle which arrange | positioned the said flame-retardant vacuum heat insulating material for vehicles is provided.
Furthermore, the present invention provides a railway vehicle in which the flame retardant vacuum heat insulating material for a vehicle is disposed on a ceiling.

According to the gas barrier laminate film for a vacuum heat insulating material of the present invention, since the outermost layer of the jacket material is composed of a flame retardant member, it is possible to ensure the flame resistance of the vacuum heat insulating material using this.
In addition, according to the gas barrier laminate film for vacuum heat insulating material of the present invention, since no metal foil is used for the outermost layer, thermal crosslinking is prevented, and excellent heat insulating properties which are the original characteristics of the vacuum heat insulating material using the same are obtained. It can be demonstrated.

  According to the gas barrier laminate film for a vacuum heat insulating material of the present invention, the flame retardant member is formed by impregnating or coating a non-flammable or flame retardant material on a natural fabric or paper base material. The heat insulation of the vacuum heat insulating material can be prevented and the bending workability is excellent.

  Moreover, since the flame-retardant vacuum heat insulating material of this invention is excellent in a flame retardance and bending workability, it can be used conveniently for vehicles, such as a railway, a motor vehicle, and a ship.

FIG. 1 is a view showing a preferred embodiment of the flame-retardant vacuum heat insulating material (200) of the present invention. From the outermost layer toward the innermost layer, the flame-retardant member layer (40), the gas barrier layer (30), and Sectional drawing of the flame-retardant vacuum heat insulating material (200) formed by laminating | stacking a core material (10) under reduced pressure with the gas-barrier laminated film (100) for vacuum heat insulating materials formed by laminating | stacking a heat-fusible resin layer (20). It is. FIG. 2 is a view for explaining the layer structure of the gas barrier laminated film (100) for a vacuum heat insulating material according to the present invention. From the outermost layer to the innermost layer, the flame retardant member layer (40), the adhesive for dry lamination It is a figure which shows the aspect by which an agent layer (70), a gas barrier layer (30), and a heat-fusible resin layer (20) are laminated | stacked sequentially. FIG. 3 is a view for explaining the layer structure of the gas barrier laminated film (100) for a vacuum heat insulating material according to the present invention. From the outermost layer toward the innermost layer, the flame retardant member layer (40) and the adhesive for dry lamination It is a figure which shows the aspect by which an agent layer (70), a plastic film layer (60), an adhesive layer (70) for dry lamination, a gas barrier layer (30), and a heat-fusible resin layer (20) are laminated | stacked in order. FIG. 4 is a view for explaining the layer structure of the gas barrier laminated film (100) for a vacuum heat insulating material according to the present invention. From the outermost layer toward the innermost layer, the flame retardant member layer (40), the adhesive for dry lamination The agent layer (70), the plastic film layer (60), the dry laminate adhesive layer (70), the gas barrier layer (30), the dry laminate adhesive layer (70), and the heat-fusible resin layer (20) are sequentially provided. It is a figure which shows the aspect laminated | stacked. FIG. 5 is a view for explaining the layer structure of the gas barrier laminated film (100) for a vacuum heat insulating material according to the present invention. From the outermost layer toward the innermost layer, the flame retardant member layer (40) and the adhesive for dry lamination The agent layer (70), the plastic film layer (60), the dry laminate adhesive layer (70), the gas barrier layer (30), the dry laminate adhesive layer (70), and the heat-fusible resin layer (20) are sequentially provided. It is a figure which shows the aspect laminated | stacked. The gas barrier layer (30) in FIG. 5 is a multilayer film in which a vapor deposition layer (33) and a gas barrier coating film (35) are laminated on a base film (31). FIG. 6 is a diagram for explaining a mode in which the vehicle flame-retardant vacuum heat insulating material (200) of the present invention is arranged in a vehicle.

  The first of the present invention is a gas barrier laminated film for a vacuum heat insulating material formed by laminating at least a flame retardant member layer, a gas barrier layer and a heat-fusible resin layer from the outermost layer to the innermost layer, The flame retardant member layer is one or more selected from a flame retardant paper and a flame retardant substance carrier formed by carrying a flame retardant substance on a natural fabric or a paper substrate. It is a gas barrier laminate film for a vacuum heat insulating material. The second of the present invention is a flame-retardant vacuum heat insulating material that is sealed under reduced pressure with the gas barrier laminated film for vacuum heat insulating material.

  A gas barrier laminated film for a vacuum heat insulating material formed by laminating at least a flame retardant member layer, a gas barrier layer and a heat-fusible resin layer from the outermost layer to the innermost layer as a packaging material for sealing the core material under reduced pressure. Since it is used, it is possible to impart flame retardancy to the vacuum heat insulating material, and the flame retardant member carries the flame retardant material on the flame retardant paper and the natural fabric or paper base material. Since it is one or more types selected from the body, it is possible to prevent melting dripping at a high temperature and to ensure bending workability by using a flame retardant member having a predetermined thickness. For this reason, it can be used suitably for vehicles, such as a railroad, a motor vehicle, and a ship where melting dripping is avoided and bending workability is requested | required.

The present invention will be described in detail with reference to FIG. 1 showing an example of a preferred embodiment of the present invention.
(1) Flame-retardant vacuum heat insulating material A cross-sectional view of a preferred embodiment of the flame-retardant vacuum heat insulating material (200) of the present invention is shown in FIG.

  The flame-retardant vacuum heat insulating material (200) of the present invention includes a core material (10) that is at least the flame-retardant member layer (40), the gas barrier layer (30), and heat-sealed from the outermost layer toward the innermost layer. It is sealed under reduced pressure with a gas barrier laminated film (100) for a vacuum heat insulating material formed by laminating a conductive resin layer (20). The core material (10) is covered and depressurized with two gas barrier laminated films (100) for vacuum heat insulating material facing the heat-fusible resin layer (20), and the gas barrier laminated film for vacuum heat insulating material is obtained. The overlapping portion (50) of the film (100) is heat-sealed and sealed.

  In the flame-retardant vacuum heat insulating material of the present invention, the reduced pressure of the core material (10) is preferably 0.1 to 10 Pa, more preferably 1 to 5 Pa. If it is this range, it is excellent in heat insulation.

  The flame retardant vacuum heat insulating material (200) of the present invention is obtained by sealing the core material (10) with two gas barrier laminated films (100) for vacuum heat insulating material under reduced pressure, but the shape of the core material (10) Can be appropriately selected depending on the application. FIG. 1 shows one embodiment of a vacuum heat insulating material obtained by sealing a square core material under reduced pressure, but is not limited to such a flat plate, and is provided with a flame retardant vacuum heat insulating material. The shape suitable for the can be selected as appropriate.

(2) Gas barrier laminated film for vacuum heat insulating material The gas barrier laminated film for vacuum heat insulating material of the present invention has at least the flame retardant member layer (40), the gas barrier layer (30), and the innermost layer from the outermost layer. A heat-fusible resin layer (20) is laminated. Since the outermost layer is the flame retardant member layer (40), flame resistance can be imparted to the vacuum heat insulating material (100). The layer structure of the gas barrier laminate film (100) in which the flame retardant member layer (40) is laminated on the gas barrier layer (30) and the heat-fusible resin layer (20) by the dry laminate adhesive layer (70) is illustrated. It is shown in 2.

  On the other hand, as a gas barrier laminated film (100) for a vacuum heat insulating material used in the present invention, a plastic film layer (60) is used for dry lamination between the gas barrier layer (30) and the flame retardant member layer (40). It may be laminated with an adhesive layer (70). This layer structure is shown in FIG. Further, the heat-fusible resin layer (20) may be laminated by an adhesive layer (70) for dry lamination. This embodiment is shown in FIG. Furthermore, the gas barrier layer (30) may be a multilayer film comprising a base film (31), a vapor deposition layer (33), and a gas barrier coating film (35). This embodiment is shown in FIG.

  The gas barrier laminate film used in the present invention is further obtained by bonding the flame retardant member layer (40) constituting the outermost layer and the gas barrier layer (30) through the adhesive layer (70) for dry lamination. The gas barrier layer (30) of the laminated body can be prepared by laminating a heat-fusible resin layer (20) constituting the innermost layer via an adhesive layer (70) for dry lamination. The thickness of the gas barrier laminate film is not limited, but is generally 12 to 38 μm.

  The gas barrier laminate film used in the present invention preferably has HB flame retardancy in the UL94 standard (Tests for Flammability of Plastic Materials for Parts in Devices and Appliances.).

In addition, the gas barrier laminated film (A) for vacuum heat insulating material has an oxygen permeability and a water vapor permeability of 0.5 (cc / m ² · day) and 0.2 (g / m ² · day), respectively, as gas barrier properties. ) Or less, preferably 0.1 (cc / m ² · day), or 0.1 (g / m ² · day) or less.

(I) Flame Retardant Member Layer The flame retardant member layer (40) in the gas barrier laminate film (100) for vacuum heat insulating material of the present invention comprises a flame retardant material on a flame retardant paper and a natural fabric or paper substrate. It is selected from a flame retardant material carrier that is carried.

In the present invention, “flame retardant paper” means a paper-like material having a basis weight of 100 to 250 g / m ² , and is not limited to a case where a paper base material is included. “Natural fabric” means vegetable fibers such as cotton and cocoon, animal fibers such as silk and wool, fabrics made of one or more fibers or particles made of mineral or glass, or the fibers This means a fabric woven with particles or a non-woven fabric composed of the above-mentioned fibers and particles. The “non-woven fabric” is a fiber sheet, web or bat, and the fibers are oriented in one direction or at random, alternating current and / or melt. The fibers are bonded by adhesion and / or adhesion.

  For example, a paper-like material obtained by combining one or more of various fibers and particles constituting the natural fabric with a binder does not include a paper base material, but can be used as a “flame retardant paper”. . For example, the flame retardant paper may be exemplified by a particle composed of a hydrous magnesium silicate compound as a main component, pulp and glass fiber blended therein, and bonded in a paper form with a binder. In the present invention, commercially available flame retardant paper can also be used. Examples of such flame retardant paper include Grandex Co., Ltd. and a trade name “non-flammable paper GP”.

In addition, when the natural fabric is made of a fiber made of mineral, glass or the like, has a flame retardancy by itself, and is prepared into a paper-like material having a basis weight of 100 to 250 g / m ² , the above “ It shall be included in “flame retardant paper”.

Further, in the present invention, the “flame retardant material carrier” means a flame retardant material provided with a flame retardant material (45) on the natural fabric (41) or the paper base material (43) and imparting incombustibility. It is a member (40).
Examples of the natural fabric (41) constituting the flame retardant member layer (40) include plant fibers such as cotton and silk, animal fibers such as silk and wool, fibers and particles made of minerals and glass. It is a fabric knitted from more than one species, a fabric woven from the fibers and particles, or a nonwoven fabric composed of the fibers and particles, and it does not matter whether the natural fabric itself is flame retardant.

Moreover, as a paper base material (43) which comprises a flame-retardant member layer (40), what has formability, bending resistance, rigidity, waist, intensity | strength, etc. can be used, for example, strong size Sexually exposed or unbleached paper substrates can be widely used. As the papermaking pulp used for papermaking, any of those used in ordinary papermaking can be used. For example, softwood unbleached kraft pulp (N-UKP), softwood bleached kraft pulp (N -BKP), hardwood bleached kraft pulp (L-BKP), softwood bleached sulfite pulp (N-BSP) and other wood pulp as the main material, and non-wood pulp such as hemp, cotton, straw pulp, kenaf and the like can also be used. In addition to the above-mentioned pulp, organic synthetic fiber and glass fiber, carbon fiber made of polyolefin synthetic pulp, polyester fiber, acrylic fiber, rayon fiber, vinylon fiber are used for enhancing paper strength and / or dimensional stability. You may use together at least 1 type of various fibers from the inorganic fiber which consists of a group. In addition, an internal sizing agent, a paper strength agent, a filler, a sulfate band (aluminum sulfate), a yield improver, a dye, a fluorescent dye, and the like are appropriately used in the stock. As the internal sizing agent, alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), neutral rosin, acidic rosin and the like are appropriately used. As the paper strength agent, starch, modified starch, polyacrylamide and the like are appropriately used. As the filler, calcium carbonate, talc, clay, titanium dioxide or the like is appropriately used. As the yield improver, colloidal silica, polyacrylamide, polyethyleneimine, or the like is appropriately used. The production method of the base paper for impregnation used for the flame-retardant coated paper is not particularly limited, and is a single layer or a multilayer using a known paper machine, that is, a long net, a round net, a hybrid former, a gap former, or the like. The base paper is usually made with a basis weight of about 70 to 220 g / m ² through a pressing step and a drying step. The papermaking method is not particularly limited and may be any of acidic paper, neutral paper, or alkaline paper, but neutral paper is preferable. Commercially available paper base materials can also be used. For example, various paper substrates such as pure white roll paper, kraft paper, paperboard, processed paper, etc. can be exemplified.

Natural fabric (41) or paper substrate (43) constituting the flame-retardant member layer (40), preferably a basis weight of 20 to 60 g / m ^2, more preferably 30 to 50 g / m ² is there. In order to ensure the prescribed flame retardancy, it is necessary to carry a prescribed amount of non-flammable or flame retardant material on the natural fabric (41) or paper substrate (43), but the basis weight is 20 g / m ² . If it is less than the range, it may be difficult to support the flame retardant material. On the other hand, if the basis weight exceeds 60 g / m ² , bending workability may decrease.

  Examples of the flame retardant substance (45) that can be used for the flame retardant substance carrier include flame retardant substances (water-insoluble) such as inorganic compounds, ammonium salts, guanidine salts, and metal salts. More specifically, inorganic such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, dihydrate gypsum and calcium aluminate, calcium silicate, aluminum sulfate, iron sulfate, phosphoric acid, condensed phosphoric acid, sulfamic acid, sulfuric acid, boric acid, etc. Inorganic compounds such as acids such as ammonium phosphate, ammonium polyphosphate, ammonium sulfamate, ammonium sulfate, ammonium borate, ammonium silicate, ammonium bromide, ammonium chloride, etc. Guanidine sulfate, 2 guanidine phosphate, 1 guanidine phosphate, methylol phosphate guanidine, phosphate guanidine salt, phosphate dimethylol guanidine, guanidine hydrobromide, Tiger bromine phthalic acid guanidine, guanidine hydrochloride, methylol guanidine hydrochloride, borate, guanidine salts such as tetramethylammonium borate guanidine, for example borax, water glass, stannate soda, metal salts such as tungsten sodium and the like. Inorganic acids that do not contain halogen, ammonium salts that do not contain halogen, guanidine salts that do not contain halogen, and metal salts that do not contain halogen are preferable because they do not generate harmful halides during combustion. More preferred are sulfamic acid, sulfuric acid, boric acid, phosphoric acid, ammonium sulfamate, ammonium sulfate, ammonium phosphate and the like. These can be used alone or in combination of two or more. A binder can be used in combination with these flame retardant materials.

  When these are water-soluble, they can be impregnated and supported on the natural fabric (41) or paper substrate (43), and when they are insoluble, the natural fabric (41) or paper base can be coated by coating. It can be carried on the material (43).

The impregnation of the flame retardant material (45) into the natural fabric (41) or the paper base material (43) can be performed with an on-machine size press apparatus or an impregnation coater, but is not limited thereto. These impregnation amounts are 40 to 240 g / m ² (dry mass), preferably 70 to 150 g / m ² (dry mass). This is because within this range, the flame retardancy is excellent and the bending workability is also excellent.

  In the present invention, the flame retardant substance (45) is applied to the natural fabric (41) or the paper base (43) by using a prepared coating composition such as a pipe coater, a blade coater, an air coater. Off-machine coater or on-machine coater using a coater selected from knife coater, roll coater, reverse roll coater, bar coater, rod blade coater, short dwell coater, curtain coater, die coater, gravure coater, champlex coater, etc. Then, it may be applied in a single layer or multiple layers. An air knife coater, a curtain coater, a rod coater, etc. are preferable from the liquid property of a coating material, More preferably, it is an air knife coater.

The coating layer can be provided as a single layer or two or more layers on one side or both sides of the natural fabric (41) or the paper base (43). The coating amount is preferably less than 40 to 240 g / m ² (dry mass) per side, more preferably 70 to 150 g / m ² (dry mass). This is because within this range, the flame retardancy is excellent and the bending workability is also excellent. Moreover, it is because a basic weight can be restrict | limited to 70-150 g / m < ² > as a flame-retardant member layer (40), More preferably, it is 120-200 g / m < ² >.

  In the present invention, a commercially available product can also be used as a flame retardant substance carrier formed by carrying a flame retardant substance on a natural fabric or a paper substrate. For example, a product name “OK Cosmo” manufactured by Oji Paper Co., Ltd., in which a paper base material (43) is highly filled with a non-combustible or flame retardant material mainly composed of aluminum hydroxide or calcium carbonate, is preferably used. be able to.

  The flame retardant member layer used in the present invention has a flame retardance of 24 to 35 as defined by JIS K7201. It should be noted that “flame retardant” in the present invention includes incombustibility.

(Ii) Gas barrier layer The gas barrier layer (30) may be any gas barrier layer as long as it has a gas barrier property capable of sealing the core under reduced pressure, such as a metal foil such as an aluminum foil, a polyvinyl alcohol film, an ethylene vinyl copolymer film, or the like. Polyvinyl alcohol-based resin, other films such as polyethylene terephthalate, etc. on which a vapor-deposited layer of metal, metal oxide, silicon oxide or the like is laminated, and such vapor-deposited film with polyvinyl alcohol-based resin and / or ethylene. The thing provided with the gas-barrier coating film by the gas-barrier composition containing a vinyl alcohol copolymer can be illustrated.

  In the case of using a metal foil, the thickness of the metal foil is generally 5 to 9 μm. Even when a metal foil is used as the gas barrier layer, if the thickness of the metal foil is in the above range, heat conduction can be avoided and heat insulation can be maintained high.

  Commercially available products can also be used as the gas barrier layer. For example, trade names “IB-PET” and “IB-PET-PXB” manufactured by Dai Nippon Printing Co., Ltd., trade names “Barrier Rocks” 1011 "etc. can be used suitably. In particular, IB-PET and IB-PET-PXB are excellent in gas barrier properties, and are excellent in flexibility and mechanical strength. Therefore, even when wrinkles occur in the gas barrier laminated film (100) for vacuum heat insulating materials. However, it is possible to avoid the occurrence of cracks in the gas barrier laminate film for vacuum heat insulating material (100) and to maintain the vacuum heat insulating effect for a long time.

(Iii) Heat-seal layer The heat-seal layer (20) constitutes the innermost layer and can be sealed by heat-seal when producing a vacuum heat insulating material by sealing the periphery of the core under reduced pressure. As the resin constituting the heat-sealing layer, a polyolefin resin can be preferably used. Specifically, low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene -Ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-α / olefin copolymer polymerized using metallocene catalyst, polypropylene, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer Polyolefin resins such as methylpentene polymer, polybutene polymer, polyethylene or polypropylene modified with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, Vinyl acetate Resins, poly (meth) acrylic resin, resins such as polyvinyl chloride resin.

  The heat-sealing layer is generally 20 to 100 μm, and the heat-sealing film may be laminated on the gas barrier layer or the heat-sealing layer may be extruded and laminated on the gas barrier layer. When using a heat-sealing film, it may be laminated on the gas barrier layer via an adhesive layer for dry lamination.

(Iv) Plastic film layer In order to give rigidity and mechanical strength to the gas barrier laminated film (100) for vacuum heat insulating material used in the present invention, it is between the gas barrier layer (30) and the flame retardant member layer (40). A plastic film layer (60) may be laminated on the substrate.

  Examples of the plastic film layer (60) include polyamide resins such as various 6,6 nylons, polyolefin resins such as polyethylene resins or polypropylene resins, cyclic polyolefin resins, polystyrene resins, acrylonitrile-styrene copolymer. Copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), poly (meth) acrylic resin, polycarbonate resin, polyvinyl alcohol resin, saponified ethylene-vinyl ester copolymer, polyethylene terephthalate, polyethylene Various resin films such as polyester resins such as naphthalate, polyurethane resins, acetal resins, cellulose resins, and the like can be used. As the substrate film, any of an unstretched film of the resin and a film stretched in a uniaxial direction or a biaxial direction can be used. The film thickness of the substrate film is preferably about 6 to 2000 μm, more preferably about 9 to 100 μm.

(V) Laminating adhesive In the present invention, for laminating the heat-fusible layer (20) and the gas barrier layer (30), bonding the plastic film layer (60) and the flame retardant member layer (40), etc. It can laminate | stack using the dry lamination lamination method through the adhesive agent (70) for lamination. In addition, when any two layers are laminated, they can be adhered by a dry laminate lamination method through a laminating adhesive.

  The adhesive for laminating comprises a polyvinyl acetate adhesive, a homopolymer such as ethyl acrylate, butyl, 2-ethylhexyl ester or a copolymer of these with methyl methacrylate, acrylonitrile, styrene, etc. Polyacrylate adhesives, cyanoacrylate adhesives, ethylene copolymer adhesives composed of copolymers of ethylene and monomers such as vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid, etc., cellulose adhesives , Polyester adhesive, polyamide adhesive, polyimide adhesive, urea resin or melamine resin amino resin adhesive, phenol resin adhesive, epoxy adhesive, polyurethane adhesive, reactive type (meta ) Acrylic acid adhesive, chloroprene rubber, nitrile Beam, styrene - inorganic adhesive made of butadiene rubber, a silicone-based adhesive, an alkali metal silicate, inorganic adhesive made of low-melting glass, it is possible to use other adhesives.

  More preferably, for example, aromatic polyisocyanate such as tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, or aliphatic polyisocyanate such as hexamethylene diisocyanate, xylylene diisocyanate, etc. Mainly used are polyether polyurethane resins, polyester polyurethane resins, and polyacrylate polyurethane resins obtained by reacting polyfunctional isocyanates with polyether polyols, polyester polyols, polyacrylate polyols, and other hydroxyl group-containing compounds. Ingredients. According to these, a thin film rich in flexibility and flexibility can be formed, its tensile elongation is improved, it acts as a film having flexibility, flexibility, etc. on the deposited film or coating film, and laminate Processing suitability such as processing and printing processing can be improved, and the occurrence of cracks in the deposited film and coating film can be avoided.

  The composition system of these adhesives may be any composition form such as an aqueous type, a solution type, an emulsion type, and a dispersion type, and the property may be any of a film, a sheet, a powder, a solid, and the like. Furthermore, the reaction mechanism may be any of a chemical reaction type, a solvent volatilization type, a heat welding type, a hot pressure type, and the like.

Although there is no limitation in the usage-amount of the adhesive agent for lamination, Generally, it is 0.1-10 g / m < ² > (dry state). The laminating adhesive can be applied by roll coating, gravure coating, kiss coating or other coating methods or printing methods.

(3) Core material The core material (10) used in the flame-retardant vacuum heat insulating material of the present invention is a porous material having a core material porosity of 50% or more, more preferably 90% or more, and low thermal conductivity. The material can be widely used.

  Examples of substances constituting such a core material include powder, foam, and fiber. The powder may be either inorganic or organic, and includes dry silica, wet silica, conductive powder, pearlite, and the like. A mixture of dry silica and conductive powder is advantageous when used in a temperature range in which an increase in internal pressure occurs because deterioration in the heat insulation performance associated with an increase in internal pressure of the vacuum heat insulating material is small. Furthermore, when a substance having a small infrared absorptance such as titanium oxide, aluminum oxide or indium-doped tin oxide is added as a radiation suppressing material, the infrared absorptivity of the core material can be reduced. Examples of the foam include urethane foam, styrene foam, phenol foam, and the like. Among these, a foam that forms open cells can be preferably used. Furthermore, as a fiber body, there exist an inorganic type and an organic type, and an inorganic fiber can be used conveniently from a viewpoint of heat insulation performance. Examples of such inorganic fibers include glass wool, glass fiber, alumina fiber, silica alumina fiber, silica fiber, and rock wool. It has low thermal conductivity and is easier to handle than powder.

  As a core material (10) used by this invention, it is not limited to when using these independently, The composite material which mixed 2 or more types may be sufficient. In the present invention, it is preferable to use a core material that can be deformed into such a curved surface because it is intended to be used for a vehicle body that frequently uses curved surfaces such as railways and subways. Glass wool, glass fiber, alumina fiber, silica alumina fiber, silica fiber, rock wool and the like can be suitably used.

(4) Manufacture of gas barrier laminated film for vacuum heat insulating material The gas barrier laminated film for vacuum heat insulating material of the present invention is obtained by laminating the flame retardant member layer on the outermost layer, and a gas barrier layer by a conventionally known method. (30) and the heat-fusible layer (20) can be produced by laminating the flame retardant member layer on, for example, a dry laminate adhesive layer.

(5) Production of flame retardant vacuum heat insulating material The flame retardant vacuum heat insulating material of the present invention is opposed to the innermost layer of the gas barrier laminated film for vacuum heat insulating material of the present invention, and the core material is placed therebetween. One of the outer circumferences of the core material is made an opening by a bag making machine, and the remaining three gas barrier laminate films are heat-sealed, and then attached to a vacuum sealing machine, and the opening is reduced to an internal pressure of 3 Pa. It can be manufactured by sealing.

(6) Incombustible vacuum heat insulating material for vehicles and vehicle Since the outermost layer of the incombustible vacuum heat insulating material of the present invention is composed of a flame retardant member, flame resistance can be imparted to the vacuum heat insulating material. . For this reason, for example, it can use suitably as a heat insulating material of vehicle bodies, such as a railway, a subway, a ship, and a motor vehicle with a high request | requirement to a flame retardance and a nonflammability.

  Also, railway vehicles adopt a so-called double skin structure from the viewpoint of weight reduction and pressure resistance improvement due to rationalization of production and higher speed, and these vehicle bodies and the roof structure in order to reduce weight and improve pressure resistance. Has a curved surface. Since the flame-retardant vacuum heat insulating material of the present invention is thin, excellent in heat insulating properties and excellent in flexibility, in order to secure a wide passage width of a subway or railway vehicle, it is provided on the lower surface portion of the vehicle body window having a curved surface. It can arrange suitably.

  In addition, the flame retardant member used in the flame retardant vacuum heat insulating material of the present invention is selected from flame retardant paper and a flame retardant substance carrier formed by carrying a flame retardant substance on a natural fabric or paper base material. Therefore, unlike a flame-retardant substance made of a synthetic resin such as a fluorine-based film or an imide-based film, there is no possibility of melting and dropping due to heating. Moreover, since heat conductivity is low compared with the case where aluminum foil is used as a flame-retardant member, it is excellent also in heat insulation. For this reason, it should be used suitably for the ceiling of railways, subways, ships, automobiles and other vehicle bodies that require high heat insulation and flame retardance and that require avoidance of molten dripping from the ceiling even in the event of a fire. Can do. A mode used for the interior of a railway vehicle is shown in FIG. Although FIG. 6 shows a mode in which the flame-retardant vacuum heat insulating material (200) of the present invention is disposed in the periphery of the lower portion of the seat excluding the floor portion and door portion, and the ceiling portion of the vehicle, the present invention is not limited to this. However, a high degree of heat insulation and safety can be ensured by arranging it at any one of the bottom, waist, ceiling, and other air conditioning ducts on the indoor side of the vehicle body.

  As shown in the examples described later, the flame-retardant vacuum heat insulating material of the present invention does not generate smoke and carbonization, and thus has excellent safety and excellent bending workability. Therefore, as shown in FIG. 6, places where heat insulation is required, such as the bottom, waist, ceiling, and other parts of air conditioning ducts, such as railways, subways, ships, automobiles, etc., composed of many curved surfaces. Can be suitably used. The vehicle on which the flame-retardant vacuum heat insulating material of the present invention is disposed is not limited to a double skin structure, and can be suitably used for a vehicle body having a single skin structure.

As described above, the flame-retardant vacuum heat insulating material for a vehicle according to the present invention is excellent in heat insulating properties by being disposed on the indoor side of a vehicle body of a railway vehicle that is formed in a curved surface in the circumferential direction of the vehicle body. Can be ensured widely, and there is no melting dripping from the ceiling even in the event of a fire, and the vehicle can be excellent in safety.

Next, the present invention will be described in more detail by showing specific examples.

Example 1
A gas barrier film (Dai Nippon Printing Co., Ltd., trade name “IB-PET-PXB”) obtained by vapor-depositing alumina by a physical vapor deposition method on a stretched nylon having a thickness of 15 μm and a polyethylene terephthalate having a thickness of 12 μm as a gas barrier layer. Bonded with an adhesive for dry lamination, a polyethylene film with a thickness of 50 μm is bonded to the gas barrier film with an adhesive for dry lamination, and filled with inorganic powder as a flame retardant member to the stretched nylon Paper (aluminum hydroxide paper: basis weight 130 g / m ² ) was adhered with an adhesive for dry lamination to produce a gas barrier laminated film (1) for vacuum heat insulating material.

The basis weight, oxygen index, oxygen permeability, and water vapor permeability of the flame retardant member used above were evaluated by the following methods. The results are shown in Table 1. Further, the thickness and flame retardancy test of the obtained gas barrier laminated film (1) for vacuum heat insulating material were evaluated by the following methods. The results are shown in Table 2.

(Measuring method)

(1) Basis weight Basis weight: JIS P 8124 In 1998, after adjusting the humidity at 23 ° C. and 50% RH, it was evaluated by “paper and paperboard—basis weight measurement method”.

(2) Oxygen index Oxygen index: The oxygen index was evaluated according to the oxygen index defined in JIS K7201.
(3) Oxygen permeability Under the conditions of a temperature of 23 ° C. and a humidity of 90% RH, the oxygen permeability was measured with a measuring instrument [model name, OX-TRAN 2/21] manufactured by MOCON, USA.

(4) Water vapor permeability Measured with a measuring instrument (model name, Permatran 3/31) manufactured by MOCON, USA, under conditions of a temperature of 40 ° C. and a humidity of 90% RH.

(5) Thickness Thickness: JIS P 8118 In 1998, after adjusting the humidity at 23 ° C. and 50% RH, it was evaluated by “Paper and paperboard—Test method of thickness and density”.

(6) Flame retardant test Flame retardant test: Safety standard UL (Underwriters Laboratories Inc.) 94 “Tests for Flammability of Plastic Materials for Parts in Devices and Appliances, fifth edition, (Edition Date October 29, 1996)” horizontal combustion It carried out according to the test (HB) method.

(Example 2)
An aluminum foil having a thickness of 7 μm is adhered to a stretched nylon having a thickness of 15 μm as a gas barrier layer with an adhesive for dry lamination, and a polyethylene film having a thickness of 50 μm is adhered to the gas barrier layer with an adhesive for dry lamination. A gas barrier laminated film for vacuum heat insulating material by bonding an inorganic powder-filled paper (aluminum hydroxide paper: basis weight 200 g / m ² ) manufactured by Oji Paper Co., Ltd. as a flame-retardant member layer with an adhesive for dry lamination ( 2) was produced.

Further, the physical properties of the flame retardant member and the gas barrier laminated film (2) for vacuum heat insulating material were evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

(Comparative Example 1)
A gas barrier film (Dai Nippon Printing Co., Ltd., trade name “IB-PET-PXB”) obtained by vapor-depositing alumina by a physical vapor deposition method on a stretched nylon having a thickness of 15 μm and a polyethylene terephthalate having a thickness of 12 μm as a gas barrier layer. Adhesive with an adhesive for dry lamination, polyethylene is laminated on the gas barrier film by melt extrusion, and laminated with a thickness of 50 μm, and an aluminum foil with a thickness of 40 μm is bonded to the stretched nylon as a flame retardant member layer with an adhesive for dry lamination Thus, a gas barrier laminated film (1) for comparative vacuum heat insulating material was produced.

Further, in the same manner as in Example 1, the physical properties of the flame retardant member and the gas barrier laminate film for comparative vacuum heat insulating material (1) were evaluated. The results are shown in Tables 1 and 2.

(Comparative Example 2)
As a gas barrier layer, polyethylene is melt-extruded into a gas barrier film (Dai Nippon Printing Co., Ltd., trade name “IB-PET-PXB”) obtained by vapor-depositing alumina on 12 μm thick polyethylene terephthalate by physical vapor deposition. Compared to the gas barrier film by bonding an inorganic powder-filled paper (aluminum hydroxide paper: basis weight 260 g / m ² ) as a flame retardant member layer to the gas barrier film with an adhesive for dry lamination. A gas barrier laminated film (2) for a vacuum heat insulating material was produced.

Further, in the same manner as in Example 1, the physical properties of the flame retardant member and the gas barrier laminated film (2) for comparative vacuum heat insulating material were evaluated. The results are shown in Tables 1 and 2.

(Example 3)
Glass wool having a basis weight of 2.5 kg / m ² was cut into a square having a length of 182 mm and a width of 257 mm to obtain a core material.

The gas barrier laminated film (1) for vacuum heat insulating material obtained in Example 1 was laminated from above and below the core material so that the polyethylene layer opposed to the core material.
Next, with the bag making machine, one of the outer circumferences of the core material was used as an opening, and the remaining three gas barrier laminated films (1) for vacuum heat insulating material were heat-sealed.

  Next, this was attached to a vacuum sealing machine, and the opening was sealed in a state where the internal pressure was reduced to 3 Pa to produce a flame-retardant vacuum heat insulating material. Further, the seal part was folded back and stopped with a fluorine-based tape (product name “Nitoflon high-strength film adhesive tape” manufactured by Nitto Denko Corporation). The thickness of the core part of the obtained flame-retardant vacuum heat insulating material was 10 mm.

The following methods evaluated the combustibility, thermal conductivity, and bending workability of the obtained vacuum heat insulating material. The results are shown in Table 3.

(1) Thermal conductivity Thermal conductivity was measured by JIS A1412-3 heat flow meter method using a thermal conductivity measuring device Auto Lambda HC-074 manufactured by Eihiro Seiki.

(2) Combustibility The obtained vacuum heat insulating material is inclined at 45 °, and placed on a stand so that the center of the bottom of the combustion container is 25.4 mm vertically below the center of the bottom surface of the vacuum heat insulating material. Add 0.5cc of alcohol, ignite, and leave until the fuel is burnt out. In the judgment of combustibility, ignition, smoke generation, carbonization after combustion, and deformation during combustion of ethyl alcohol were evaluated.

(3) Bending suitability Judgment was made based on whether or not bending was easy.

Example 4
The same operation as in Example 3 was carried out except that the gas barrier laminated film for vacuum insulation (2) obtained in Example 2 was used instead of the gas barrier laminated film for vacuum insulation (1) obtained in Example 1. And the flame-retardant vacuum heat insulating material was manufactured.

About the obtained flame-retardant vacuum heat insulating material, it carried out similarly to Example 3, and evaluated flammability, thermal conductivity, and bending workability. The results are shown in Table 3.

(Comparative Example 3)
It replaced with the gas barrier property laminated film (1) for vacuum heat insulating materials obtained in Example 1, and was similar to Example 3 except having used the gas barrier property laminated film (1) for comparative vacuum heat insulating materials obtained in Comparative Example 1. Operated to produce a comparative flame retardant vacuum insulation.

About the obtained comparative flame-retardant vacuum heat insulating material, it carried out similarly to Example 3, and evaluated flammability, thermal conductivity, and bending workability. The results are shown in Table 3.

(Comparative Example 4)
It replaced with the gas-barrier laminated | multilayer film (1) for vacuum heat insulating materials obtained in Example 1, and replaced with the gas-barrier laminated | multilayer film (2) for comparative vacuum heat insulating materials obtained by the comparative example 2 similarly to Example 3. Operated to produce a comparative flame retardant vacuum insulation.

  About the obtained comparative flame-retardant vacuum heat insulating material, it carried out similarly to Example 3, and evaluated flammability, thermal conductivity, and bending workability. The results are shown in Table 3.

(結果)
（１）比較例３と実施例３とを比較すると、使用する真空断熱材用ガスバリア性積層フィルムの厚さは略同じであるが、アルミニウム箔を最外層に有する比較例３は、熱伝導率が０．０３Ｗ／ｍ・Ｋであり、実施例３は熱伝導率が０．００３Ｗ／ｍ・Ｋであった。すなわち、実施例３の真空断熱材は、アルミニウム箔を難燃性部材とする比較例３より１０倍以上の断熱性を有していた。

(result)
(1) Comparing Comparative Example 3 and Example 3, the thickness of the gas barrier laminate film for vacuum heat insulating material to be used is substantially the same, but Comparative Example 3 having an aluminum foil in the outermost layer has a thermal conductivity. Was 0.03 W / m · K, and Example 3 had a thermal conductivity of 0.003 W / m · K. That is, the vacuum heat insulating material of Example 3 had a heat insulating property 10 times or more that of Comparative Example 3 using an aluminum foil as a flame retardant member.

(2) Comparing Comparative Example 4 and Example 3, the thickness of the gas barrier laminate film for vacuum heat insulating material used is substantially the same, but the inorganic powder having a basis weight of 260 g / m ² as the flame-retardant member layer Comparative Example 4 using body-filled paper was inferior in bending workability, but Example 3 was excellent in bending workability because inorganic powder-filled paper having a basis weight of 130 g / m ² was used.

(3) Comparing Comparative Example 3 and Example 3, the thickness of the gas barrier laminated film for vacuum heat insulating material used is substantially the same, but an aluminum foil having a thickness of 40 μm was used as the flame retardant member layer. Although Comparative Example 3 was inferior in bending workability, Example 3 was excellent in bending workability because an inorganic powder-filled paper having a basis weight of 130 g / m ² was used. This proves that the aluminum foil conventionally used as the outer covering material of the vacuum heat insulating material is not only inferior in heat insulating properties but also in bending workability.

(4) Comparing Comparative Example 3 and Example 4, the thickness of the gas barrier laminate film for vacuum heat insulating material to be used is substantially the same, but an aluminum foil having a thickness of 40 μm was used as the flame retardant member layer. Although Comparative Example 3 was inferior in bending workability, Example 4 was excellent in bending workability because an inorganic powder-filled paper having a basis weight of 200 g / m ² was used. This indicates that when inorganic powder-filled paper is used as the flame retardant member, the bending workability is excellent if it is less than 250 g / m ² .

  The flame-retardant vacuum heat insulating material of the present invention has little thermal crosslinking, is excellent in heat insulating properties, is excellent in bending workability, and can be applied as a vacuum heat insulating material disposed in railways, ships, vehicles, and the like.

10 ... Core material,
20 ... heat-fusible resin layer,
30 ... gas barrier layer,
40 ... Flame retardant member layer,
50: Overlapping portion of gas barrier laminate film (100) for vacuum heat insulating material,
60 ... plastic film layer,
70: Adhesive layer for dry lamination,
100: Gas barrier laminated film for vacuum heat insulating material,
200 ... Vacuum insulation

Claims (6)

A gas barrier laminate film for a vacuum heat insulating material obtained by laminating at least a flame retardant member layer, a gas barrier layer and a heat-fusible resin layer from the outermost layer to the innermost layer,
The flame retardant member layer is one or more selected from a flame retardant paper and a flame retardant substance carrier formed by carrying a flame retardant substance on a natural fabric or a paper substrate. Gas barrier laminate film for vacuum insulation. The flame retardant member layer is characterized by a basis weight of 100 to 250 g / m ^2, claim 1 the gas-barrier multilayer film for vacuum insulation material according.   A flame-retardant vacuum heat insulating material which is sealed under reduced pressure with the gas barrier laminated film for a vacuum heat insulating material according to claim 1 or 2.   The flame-retardant vacuum heat insulating material for vehicles consisting of the flame-retardant vacuum heat insulating material of Claim 3.   A vehicle provided with the flame-retardant vacuum heat insulating material for vehicles according to claim 4.   A railway vehicle in which the flame-retardant vacuum heat insulating material for vehicles according to claim 4 is disposed on a ceiling portion.

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