JPH0515178B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a heat-resistant sheet, and more specifically, to a soft and flexible fiber sheet that has excellent heat resistance, excellent stitchability and bending resistance. [Conventional technology] Conventionally, polyester fiber (melting point 255-260℃),
A thermoplastic resin such as polyvinyl chloride (PVC, heat-resistant temperature 66-79°C), polyurethane (heat-resistant temperature 90-120°C), acrylic resin on a fibrous base fabric made of polyamide fiber (melting point 215-260°C) etc. (Heatproof temperature
60-88℃), polyethylene (heat-resistant temperature 80-120℃),
Sheet materials obtained by coating polypropylene (heat resistant temperature: 120 to 160°C), polyamide (heat resistant temperature: 80 to 150°C), or polyester (heat resistant temperature: about 120°C) are known. In this case, since the melting point of the fibrous base fabric is relatively low, the coating material that covers it must be one that can be coated at a processing temperature that the fibrous base fabric can withstand.
As for the coating material, as mentioned above, a resin having relatively low heat resistance is used. However, in recent years, fiber sheet materials have been increasingly used for firefighter's suits, heat-resistant clothing, membrane building materials, etc., and in order to maintain safety from fires, burns, and other thermal disasters, fiber sheet materials Demand for flame retardancy, etc., is increasing. Therefore, the development of heat-resistant sheet materials is strongly desired. In response to the above-mentioned request, Japanese Patent Application Laid-Open No. 58-120677
No. 58-127757 and JP-A-58-127757 propose high-temperature insulation paints and fire-resistant insulation films containing alkali titanates and silicone resins, and JP-A-58-130183, JP-A Nos. 58-199791 and 59-
No. 35938 discloses a fire-resistant sheet obtained by forming a coating layer containing a silicone resin and an alkali titanate on the surface of an inorganic core material such as a glass fiber base fabric or asbestos paper. In addition, JP-A-59-26987 and JP-A-59-36157 disclose a heat-resistant composition in which a polyorganophosphonitrile compound is mixed with a silicone resin or an alkyl silicate, and a method for coating an inorganic core material with this heat-resistant composition. This is disclosed. Heat-resistant sheets using these inorganic fiber base fabrics had excellent fire-resistance, heat-insulating properties, stain resistance, and weather resistance, but their large weight (fabric weight) made them inconvenient to use and handle. , it is difficult to sew, and its bending strength is low, so it is difficult to sew, especially during use.
When used in applications that are subject to vibration or flapping, or applications that involve severe bending, there are problems in that they tend to break or tear at perforations, and there has been a strong desire to solve these problems. [Problems to be Solved by the Invention] The present invention provides a flexible and heat-resistant sheet that improves its bending strength so that it can withstand vibration, flapping, or repeated bending. This makes it easier to cut and less likely to tear from the perforations. [Means for Solving the Problems] The heat-resistant sheet of the present invention comprises inorganic fibers and
A base fabric made of a knitted fabric containing a heat-resistant organic synthetic fiber having a melting point of 300°C or higher or a thermal decomposition point, and a 20 to 100 weight fabric impregnated or coated on this base fabric and having a melting point of 300°C or lower. % fluorine-containing resin,
and a heat-resistant coating layer containing 80 to 0% by weight of a heat-resistant inorganic material. Further, in the heat-resistant sheet of the present invention, the heat-resistant inorganic material is preferably 1 to 200 parts by weight of alkali titanate based on 100 parts by weight of the fluorine-containing resin. [Function] The heat-resistant sheet of the present invention has a base fabric made of a knitted fabric containing inorganic fibers and heat-resistant organic synthetic fibers, and a heat-resistant coating layer containing a fluorine-containing resin. The inorganic fibers constituting the base fabric used in the present invention can be selected from asbestos fibers, ceramic fibers, silica fibers, glass fibers, carbon fibers, metal fibers, and the like. Further, the organic fiber used for the base fabric in the present invention is a heat-resistant organic synthetic fiber having a melting point of 300°C or higher or a thermal decomposition temperature, and if necessary,
It may also contain other organic fibers. Such heterogeneous organic fibers include natural fibers, such as cotton, linen, etc., recycled fibers, such as viscose rayon, kyupra, etc., semi-synthetic fibers, such as g- and tri-acetate fibers, and synthetic fibers, such as polyamide fibers. (nylon 6, nylon
You can choose from fibers such as 66), polyester (polyethylene terephthalate, etc.) fibers, acrylic fibers, etc. Polymers that form the heat-resistant organic synthetic fibers having a high melting point or a high thermal decomposition point include those shown in Table 1.

【table】

【table】

【table】

[In the above formula, Ar ₁ and Ar ₂ represent divalent aromatic groups, which may be the same or different]

It is preferable to have at least one type of unit selected from the following as a main repeating unit.
In the above formulas () and (), Ar ₁ and Ar ₂
The divalent aromatic group represented by the following formula,

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】 and

[In the above formula, A represents -O-, -S-, -SO-, _-SO2- , -CO-, _-CH2- or -C( _CH3 ) _2- ]

Preferably, it is selected from the group of aromatic residues shown below. These aromatic residues may contain inert substituents such as halogens, alkyl groups, nitro groups, and the like. Generally, the aromatic polyamide has the following formula: More preferred are those having the repeating unit represented by as a main component. In addition to the above-mentioned heat-resistant organic synthetic fibers, fluorine-based fibers and other fibers can also be used as long as they have a melting point or thermal decomposition point of 300° C. or higher. When heat-resistant organic synthetic fibers are used, the weight ratio of the heat-resistant organic synthetic fibers to the inorganic fibers in the base fabric is preferably within the range of 10:90 to 90:10.
More preferably, the ratio is within the range of 20:80 to 80:20. In addition, in order to promote adhesion with the heat-resistant coating phase and other properties, fibers having a melting point or thermal decomposition point lower than 300°C, such as organic fibers different from the heat-resistant organic synthetic fibers, may be added to the base fabric. It can also be used in combination with However, heat-resistant fibers (total amount of inorganic fibers and heat-resistant organic synthetic fibers) in the base fabric
is preferably contained in an amount of 50% by weight or more, more preferably 60% by weight or more. The inorganic and heat-resistant organic synthetic fibers and different organic fibers in the base fabric may be in any form such as short fiber spun yarn, long fiber yarn, split yarn, tape yarn, etc. It may be any knitted fabric. However, in consideration of the strength of the sewn portion and the bending resistance, it is preferable to use a woven fabric as the base fabric. Further, as for the form of the fibers, it is preferable that the fibers are in the form of long fibers (filaments) that have little elongation under stress, and that they form a plain woven fabric. However, there are no particular limitations on the weaving structure or form of the base fabric. Heat-resistant organic synthetic fibers are useful for maintaining the mechanical strength of the resulting heat-resistant sheet at a high level. In the base fabric, the inorganic fibers and the heat-resistant organic synthetic fibers may be mixed in any manner. For example, it may be any of blended yarns, interwoven fabrics, intertwisted yarns, and aligned yarns. However, it is preferable that the base fabric contains 10% by weight or more of heat-resistant organic synthetic fibers, and more preferably 20% by weight or more.
Further, it is preferable that the base fabric contains inorganic fibers in an amount of 10% by weight or more, more preferably 20% by weight or more. When glass fiber is used as the inorganic fiber,
Although there are no particular limitations on the type or fineness, generally beta yarns with a thickness of about 2 to 10 μm, particularly about 3 μm, are used. In the heat-resistant sheet of the present invention, the heat-resistant coating layer contains 20 to 100% by weight of a fluorine-containing resin having a melting point of 300°C or less and 80 to 0% by weight of a heat-resistant inorganic material. The fluorine-containing resin used in the present invention has a melting point of 300°C or less, and includes tetrafluoroethylene-perfluoroolefin copolymer (e.g., tetrafluoroethylene-hexafluoropropylene copolymer), tetrafluoroethylene-hexafluoropropylene copolymer,
Perfluoro(alkyl vinyl ether) copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-perfluoroalkyl ethylene copolymer, polychlorotrifluoroethylene, polyvinylfrideneolide, polyvinyl fluoride,
and chlorotrifluoroethylene-ethylene copolymer. The heat-resistant coating layer of the present invention contains fluorine-containing resin from 20 to 20%.
Contained at a content of 100% by weight. If the content of the fluorine-containing resin is less than 20% by weight, the resulting heat-resistant coating layer will have insufficient flexibility and bending resistance, and will have unsatisfactory sewability and adhesion to the base fabric. Although the above-mentioned fluorine-containing resins have extremely good weather resistance, ultraviolet absorbers may be blended into these resins for the purpose of protecting the base fabric. It goes without saying that colorants and other performance-imparting agents may also be added. The coating layer made of these resins may be microporous or may have continuous or discontinuous cells. The heat-resistant coating layer of the present invention contains 80-0% by weight of heat-resistant inorganic material. As this heat-resistant inorganic material, for 100 parts by weight of the fluorine-containing resin,
Preferably, it is 1 to 200 parts by weight of alkali titanate. The alkali titanate used in the present invention has the general formula M ₂ O・nTiO ₂・mH ₂ O (in the formula, M represents an alkali metal such as Li, Na, K, etc., and n represents a positive real number of 8 or less). , m represents 0 or a positive real number of 4 or less), and more specifically, Li ₄ TiO ₄ Li ₂ TiO ₃ (0<n<1, m=
Alkali titanate with a salt-type structure represented by 0), Na ₂ Ti ₇ O ₁₅・K ₂ Ti ₆ O ₁₅・K ₂ Ti ₈ O ₁₇ (0<6,
This includes alkali titanate with a tunnel structure represented by m=0). Among these, the general formula
Potassium hexatitanate and its hydrate, represented by K ₂ O・6TiO ₂・mH ₂ O (in the formula, m is the same as above), are suitable for greatly improving the fire resistance and heat insulation properties of the final product. be. Alkali titanates, not just potassium hexatitanate, are generally powder or fibrous microcrystals, but among these, the fiber length is 5 μm.
As described above, aspect ratios of 20 or more, particularly 100 or more, bring about favorable results in improving the strength of the heat-resistant sheet of the present invention. Further, fibrous potassium titanate in particular has a high specific heat and excellent heat insulation performance, and is particularly effective for further improving the heat resistance and heat insulation performance of the heat-resistant sheet of the present invention. Furthermore, the heat-resistant coating layer of the present invention may contain a high refractive index inorganic compound or a heat-absorbing inorganic compound. High refractive index inorganic compounds have excellent shielding performance against radiant heat, and when endothermic inorganic compounds come into direct contact with slag during welding or fusing, they are heated at this contact surface, and an endothermic reaction occurs during decomposition, causing the temperature of the slag to rise. decrease. Therefore, the above-mentioned inorganic compound can suppress the collapse and thermal penetration damage of the heat-resistant coating layer of the present invention, and can further protect the heat-resistant sheet base material. High refractive index inorganic compounds useful in the present invention have a refractive index of
It may have a specific gravity of 1.5 or more, but those with a specific gravity of 2.8 or more are particularly suitable, and examples thereof include the following. (1) Dolomite (dolomite: specific gravity 2.8-2.9, refractive index 1.50-1.68) Magnesite (rhizoite: specific gravity 3.0-3.1, refractive index 1.51-1.72) Aragonite (specific gravity 2.9-3.0, refractive index 1.53-1.68) ) Avatite (apatite: specific gravity 3.1-3.2, refractive index 1.53-1.54) Spinel (spinel: specific gravity 3.5-3.6, refractive index 1.72-1.73) Corundum (specific gravity 3.9-4.0, refractive index 1.76-1.77) Zircon (specific gravity 3.90 -4.10, refractive index 1.79-1.81) Powder of crushed natural or synthetic minerals such as silicon carbide (specific gravity 3.17-3.19, refractive index 2.65-2.69). (2) fine powders or granules of frits or high refractive glasses or dissolved phosphorus fertilizers obtained as solid solutions of phosphate and serpentine and other similar solid solutions;
Fibrous materials or foams, etc. In addition, endothermic inorganic compounds include calcined gypsum, alum, calcium carbonate, aluminum hydroxide, hydrosalcite-based aluminum silicate, etc., crystal water releasing type, carbon dioxide gas releasing type, decomposition endothermic type, phase change type, etc. Examples include type inorganic compounds. When an alkali titanate and, if necessary, a high refractive index inorganic compound and/or an endothermic inorganic compound are mixed and dispersed in a fluorine-containing resin, a mixture for a heat-resistant coating layer for producing a heat-resistant sheet according to the present invention can be obtained. It will be done. All known means can be used to prepare the mixed dispersion. In addition, the heat-resistant coating layer mixture includes dispersants and defoamers to homogeneously disperse each component, colorants to adjust color and mechanical strength, resin powder, flame retardants, metals, etc. Powder and other various fillers can be mixed freely. Incidentally, it is preferable to mix metal powder such as copper powder, nickel powder, titanium powder, silicon, brass powder, aluminum powder, iron powder, etc. from the viewpoint of improving the surface heat reflection effect and the heat penetration suppressing effect. The surface of the base fabric can be coated with the heat-resistant coating layer by applying the heat-resistant coating mixture to the surface of the base fabric by spraying, brushing, roll coating, etc., or by molding the heat-resistant coating mixture. There is a method in which a processed film is attached to the surface of a base fabric, or a method in which the base fabric is immersed in a heat-resistant coating mixture to be impregnated. The heat-resistant sheet of the present invention is manufactured, for example, as follows. That is, after adding an appropriate curing accelerator and additives to a mixture of a fluorine-containing resin, an alkali titanate, and, if necessary, a high refractive index inorganic compound and/or an endothermic inorganic compound, toluene, xylene, or trichlene is added as necessary. A dispersion liquid of an appropriate concentration is prepared by adding an organic solvent such as This dispersion is impregnated into the base fabric by conventionally well-known impregnation methods such as dipping, spraying, roll coating, reverse roll coating, and knife coating, or by coating on one or both sides of the base fabric. Apply. Impregnation with the above-mentioned dispersion liquid is carried out by the above-mentioned dipping method, and application is carried out by a spraying method, a roll coating method, a reverse roll coating method, a knife coating method, or the like. Whether to use the impregnation method or the coating method may be appropriately determined depending on the structure, thickness, and type of the base fabric, the intended use of the resulting heat-resistant sheet, and the desired performance and texture. Next, the base fabric impregnated or coated with the fluorine-containing resin-containing dispersion as described above is heated at 400°C or less.
Preferably 150-370°C, more preferably 150-350°C
The heat-resistant coating layer is integrally fixed to the base fabric by heat treatment within the range of 1 to 30 minutes. The blending ratio of the fluorine-containing resin, alkali titanate, high refractive index inorganic compound, and/or endothermic inorganic compound, etc. varies depending on the type and particle size of the fluorine-containing resin and heat-resistant inorganic compound used, but in general, the content of the fluorine-containing resin If the ratio is less than 20% by weight, the strength of the heat-resistant coating layer will be insufficient, and as a result, when the obtained heat-resistant sheet is used for fire-resistant insulation, cracks may occur in the heat-resistant coating layer, or the heat-resistant coating layer may become unstable. This causes disadvantages such as peeling off from the cloth. In the present invention, the amount of alkali titanate added to 100 parts by weight of the fluorine-containing resin is 1 to 200 parts by weight, preferably 30 to 100 parts by weight. When the heat-resistant coating layer of the present invention contains a fluorine-containing resin and an alkali titanate, if the content of the alkali titanate is less than 1 part by weight per 100 parts by weight of the fluorine-containing resin, the addition of the alkali titanate will improve the heat shielding property. The improvement effect will be insufficient. Moreover, even if the amount is more than 200 parts by weight, the effect will be saturated and it will be economically disadvantageous. In addition, when a heat-resistant inorganic material such as a high refractive index inorganic compound and/or an endothermic inorganic compound is blended into the heat-resistant coating layer, the content of the fluorine-containing resin
The amount is 400 parts by weight or less per 100 parts by weight, and in this case, it is preferably used together with the alkali titanate in an amount of the same weight to 1/4 of the weight of the alkali titanate. 10 to 300 per 100 parts by weight of ordinary fluorine-containing resin
It is preferable to use within the range of parts by weight. still,
These alkali titanates, high refractive index inorganic compounds,
Part or all of the endothermic inorganic compound can be replaced with commonly used inorganic pigments, inorganic bulking fillers, inorganic powders that impart flame retardancy, etc., but the amount of these heat-resistant inorganic materials used is The amount is 400 parts by weight or less, preferably 300 parts by weight or less, based on 100 parts by weight of the fluorine-containing resin. The thickness of the heat-resistant sheet of the present invention is preferably 0.02 mm or more, and more preferably within the range of 0.05 to 2.0 mm. In order to improve the adhesion and durability between the base fabric and the heat-resistant coating layer, an adhesive substance may be interposed between the base fabric and the heat-resistant coating layer. In this case, there is no need to interpose the layer thicker than to improve adhesive strength. Adhesive substances are not used for film formation; therefore substances known as adhesives can be used. For example, amino group, imino group, ethyleneimino residue,
Acrylates containing alkylene diamine residues, acrylates containing aziridinyl groups, aminoester-modified vinyl polymers, aromatic epoxy adhesives, amino nitrogen-containing methacrylate polymers, and other adhesives may be used in combination. Further, a resin having the same quality as the resin constituting the fiber base fabric, such as polyamideimide or polyimide, or an RFL modified substance, etc. can be arbitrarily selected. In the heat-resistant sheet of the present invention, the heat-resistant coating layer may be formed only on one side, but may be formed on both sides to compensate for the low weather resistance of the base fabric.
Depending on the usage situation, double-sided formation may be an essential condition. Depending on the performance required for the heat-resistant sheet, the other side may be made of natural rubber, neoprene rubber, chloroprene rubber, silicone rubber, chlorosulfonated polyethylene (Hypalon) or other synthetic rubber, or PVC resin, ethylene-acetic acid. Vinyl polymer (EVA) resin, acrylic resin,
Silicone resins, urethane resins, polyester resins and other synthetic resins can also be used. In this case, it is more preferable that these resins are flame retardant. The thickness of the heat-resistant coating layer is 5 to 2000μm, especially 10 to 2000μm.
Preferably, it is 1500 μm. The heat-resistant sheet of the present invention can also be used in combination with other materials, such as foam or mat. The heat-resistant sheet of the present invention may be formed into a tape or strip, or may be cut into a tape or strip by cutting the sheet. Such a tape-like heat-resistant sheet can be used by covering or wrapping it in applications that require heat resistance and flame retardancy, such as electric wires and cables. Also, other materials,
For example, it may be used in combination with foam, net, mat, etc. [Example] The heat-resistant sheet of the present invention will be explained in more detail with reference to Examples. Comparative Example 1 A glass fiber fabric having the following structure was used as the base fabric. DE150 1/23.3 ^S / 51 pieces / 25.4 mm x 51 pieces / 25.4 mm Turkish satin weave 290 g / m ² Acrylic adhesive (SC462,
(manufactured by Sony Chemical Company) was applied at a coating amount of 30 g/m ² and dried. Separately, a fluorine-containing resin composition having the following composition was prepared. The following composition: Component amount (parts by weight) 50% aqueous dispersion of tetrafluoroethylene-hexafluoropropylene copolymer (FEP, mp275℃) 100 Water-soluble acrylic resin (thickener) 0.65 Potassium titanate (trademark: Teismo D) (manufactured by Otsuka Chemical Co., Ltd.) 60 The viscosity of this composition was approximately 900 centipoise. The base fabric is dipped into the composition, squeezed, and dried at a temperature of 250 to 300°C, and then
The coating was formed at a temperature of 350°C. The thickness of the heat-resistant coating layer obtained was approximately 150 μm on both surfaces. The obtained sheet was subjected to the fire resistance and insulation test described in JP-A-58-130183. The evaluation criteria for fire resistance and heat insulation properties at this time were as follows. Class A: When cutting a 9mm thick spark-generating steel plate,
There shall be no through-holes that are harmful to sparks and cause fire prevention. Class B: When cutting a 4.5mm thick spark-generating steel plate,
There shall be no through-holes that are harmful to sparks and cause fire prevention. Class C: There are no through-holes that are harmful to flames and fire prevention from the sparks generated when cutting a 3.2 mm thick spark-generating steel plate. Class D: When cutting a 3.2mm thick spark-generating steel plate,
Penetration holes that are harmful to fire safety occur. Class E: Flames occur when cutting a 3.2mm thick spark-generating steel plate. The fire resistance and heat insulation properties of the sheet of Comparative Example 1 were Class A. For the sheet of Comparative Example 1, JIS P8115 (1976)
When tested in accordance with the ``Test Method for Folding Durability of Paper and Paperboard Using an MIT Tester,'' the sheet broke after being bent 3,000 times. In other words, since the sheet of Comparative Example 1 used a base fabric made only of glass fibers, it had low durability against vibration, flapping, or bending. In addition, for the sheet of Comparative Example 1,
112W-115 industrial sewing machine (2 needles, lockstitch thread feed,
When I used a Nomex multifilament thread (500d) as the sewing thread, I sewed at a stitch count of 50 pitches/10cm using lockstitch, straight stitch, and double stitch. It was torn. Example 1 In the structure of the base fabric used in Comparative Example 1, two aromatic polyamide fiber yarns (Kevlar, 195 denier/130f) were used in the warp and weft for each glass fiber yarn, I created the base fabric. The base fabric was subjected to the same adhesive treatment and heat-resistant coating treatment as in Comparative Example 1 to produce a heat-resistant sheet. The fire resistance and insulation properties of this heat-resistant sheet are Class B, and in its bending strength test, it did not break even after being bent 10,000 times, showing almost infinite bending strength. Furthermore, although the same sewing as in Comparative Example 1 was performed, the sewing portion (perforation) could be sewn smoothly without tearing. Example 2 The same operation as in Example 1 was performed. However, in the base fabric, carbon fiber yarn was used instead of the glass fiber yarn. The resulting heat-resistant sheet had a fire-resistant and heat-insulating property of Class B, and a folding strength of 10,000 times or more. Further, as in Example 1, sufficient sewing properties were obtained. Example 3 The same operation as in Example 1 was performed. However, in the warp and weft of the base fabric, one glass fiber yarn was mixed with one Kevlar fiber yarn and one polyethylene terephthalate multifilament yarn. The heat treatment temperature was set at a maximum of 280°C. The resulting heat-resistant sheet had a fire-resistant and heat-insulating property of class C, exhibited folding resistance of 10,000 times or more, and exhibited good sewing properties similar to those of Example 1. Example 4 The same operation as in Example 1 was performed. However, sodium titanate was not used. The resulting heat-resistant sheet had a fire-insulating property of Class C, and a folding strength of 10,000 times or more. Further, as in Example 1, a good sutured portion was obtained. Example 5 The same operation as in Example 1 was performed. However, the fluorine-containing resin composition was applied to both sides of the base fabric using a roll coater to form a heat-resistant coating layer with a thickness of about 150 μm on each side. The performance and sewability of the obtained heat-resistant sheet were almost the same as in Example 1. [Effects of the Invention] Since the heat-resistant sheet of the present invention contains a required amount of heat-resistant organic synthetic fibers mixed with inorganic fibers, it has flexibility and excellent bending strength while maintaining the desired heat resistance. Moreover, it has excellent sewing properties, and is therefore suitable for applications that are subjected to repeated bending at high temperatures, violent vibrations, and flapping (for example, fire-resistant clothing,
It can be widely used for opening/closing curtains, etc.).

Claims (1)

[Scope of Claims] 1. A base fabric made of a knitted fabric comprising inorganic fibers and heat-resistant organic synthetic fibers having a melting point or thermal decomposition point of 300°C or higher, and a base fabric impregnated or coated on this base fabric, and A heat-resistant sheet having a heat-resistant coating layer containing 20 to 100% by weight of a fluorine-containing resin having a melting point of 300°C or less, and 80 to 0% by weight of a heat-resistant inorganic material. 2. Claim 1, wherein the inorganic fiber is selected from asbestos fiber, ceramic fiber, silica fiber, glass fiber, carbon fiber, and metal fiber.
Heat-resistant sheet as described in section. 3. The heat-resistant sheet according to claim 1, wherein the weight ratio of the heat-resistant organic synthetic fibers to the inorganic fibers in the base fabric is within the range of 10:90 to 90:10. 4. The fluorine-containing resin is a tetrafluoroethylene-perfluoroolefin copolymer, a tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, which has a melting point of 300°C or less,
From tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-perfluoroalkyl ethylene copolymer, polychlorotrifluoroethylene, polyvinyldene fluoride, polyvinyl fluoride, and chlorotrifluoroethylene-ethylene copolymer The heat-resistant sheet according to claim 1, comprising at least one selected one. 5. The heat-resistant sheet according to claim 1, wherein the base fabric further contains an organic fiber different from the heat-resistant organic synthetic fiber. 6 The heat-resistant inorganic material is the fluorine-containing resin.
The heat-resistant sheet according to claim 1, which contains 1 to 200 parts by weight of alkali titanate per 100 parts by weight. 7. The heat-resistant sheet according to claim 6, wherein the alkali titanate is potassium hexatitanate or a hydrate thereof.