Abstract: A thermal insulation sheet is used that includes a fiber, a silica aerogel contained in the fiber, and a fibrous cavity. A method for manufacturing a thermal insulation sheet is used that includes: an impregnation step of impregnating a silica aerosol in a nonwoven fabric substrate containing a fiber that is insoluble in an acidic solution, and a fiber that is soluble in the acidic solution; a gelling step of gelling the silica aerosol; a hydrophobizing step of hydrophobizing the gel; and a drying step of drying the gel. The fiber that is soluble in the acidic solution is dissolved in the hydrophobizing step.

Abstract: A thermal insulation sheet is used that includes a fiber, a silica aerogel contained in the fiber, and a fibrous cavity. A method for manufacturing a thermal insulation sheet is used that includes: an impregnation step of impregnating a silica aerosol in a nonwoven fabric substrate containing a fiber that is insoluble in an acidic solution, and a fiber that is soluble in the acidic solution; a gelling step of gelling the silica aerosol; a hydrophobizing step of hydrophobizing the gel; and a drying step of drying the gel. The fiber that is soluble in the acidic solution is dissolved in the hydrophobizing step.

Abstract: A thermal insulation sheet is used that includes a fiber, a silica aerogel contained in the fiber, and a fibrous cavity. A method for manufacturing a thermal insulation sheet is used that includes: an impregnation step of impregnating a silica aerosol in a nonwoven fabric substrate containing a fiber that is insoluble in an acidic solution, and a fiber that is soluble in the acidic solution; a gelling step of gelling the silica aerosol; a hydrophobizing step of hydrophobizing the gel; and a drying step of drying the gel. The fiber that is soluble in the acidic solution is dissolved in the hydrophobizing step.

Abstract: A thermal insulation sheet is used that includes a fiber, a silica aerogel contained in the fiber, and a fibrous cavity. A method for manufacturing a thermal insulation sheet is used that includes: an impregnation step of impregnating a silica aerosol in a nonwoven fabric substrate containing a fiber that is insoluble in an acidic solution, and a fiber that is soluble in the acidic solution; a gelling step of gelling the silica aerosol; a hydrophobizing step of hydrophobizing the gel; and a drying step of drying the gel. The fiber that is soluble in the acidic solution is dissolved in the hydrophobizing step.

Abstract: An object of the disclosure is to provide heat insulation materials that combine high heat insulation properties realizing effective heat insulation, and flame retardancy realizing prevention of fire spreading, and devices using the same. In order to achieve this object, disclosed are heat insulation materials, including: a silica xerogel; a carbon material; unwoven fabric fibers that retains the silica xerogel, and the carbon material. Further disclosed are devices, including the above-described heat insulation material, wherein the heat insulation material serves as a part of a heat-insulation or refrigeration structure, or is placed between a heat-producing component and a casing.

Abstract: With a manufacturing method of a graphite sheet, a cavity-forming sheet having a mesh structure or a nonwoven fabric structure is firstly impregnated with polyamide acid and then molded into a sheet. The molded sheet is then heat treated to imidize polyamide acid so as to produce a polyimide sheet composed of polyimide and the cavity-forming sheet disposed in polyimide. The polyimide sheet is then fired in a non-oxidizing atmosphere to pyrolyze the polyimide so as to produce the graphite sheet. The cavity-forming sheet is made of material which maintains a shape thereof when the polyimide sheet is produced and which gasifies and loses at least 80% of its weight when the polyimide is pyrolyzed.

Abstract: With a manufacturing method of a graphite sheet, a cavity-forming sheet having a mesh structure or a nonwoven fabric structure is firstly impregnated with polyamide acid and then molded into a sheet. The molded sheet is then heat treated to imidize polyamide acid so as to produce a polyimide sheet composed of polyimide and the cavity-forming sheet disposed in polyimide. The polyimide sheet is then fired in a non-oxidizing atmosphere to pyrolyze the polyimide so as to produce the graphite sheet. The cavity-forming sheet is made of material which maintains a shape thereof when the polyimide sheet is produced and which gasifies and loses at least 80% of its weight when the polyimide is pyrolyzed.