In a method for manufacturing an aerogel, an acid is added to a first aqueous high-molar-ratio silicate solution that includes silica particles having a mean particle diameter of from 1 nm to 10 nm and that is alkaline, to produce a gel. The gel is subjected to a dehydration condensation to obtain a hydrogel. The hydrogel is converted into a hydrophobized gel. Then, the hydrophobized gel is dried. According to the method, an aerogel having a pore volume of from 3.00 cc/g to 10 cc/g, a mean pore diameter of from 10 nm to 68 nm, and a specific surface area of from 200 m.sup.2/g to 475 m.sup.2/g can be prepared.

A thermally-insulating sheet includes a thermal insulator which includes a fiber sheet made of fibers providing spaces among the fibers, a resin layer provided on a part of a surface of the fiber sheet, the first resin having a denser surface than the fiber sheet, and a silica xerogel held in the spaces of the fiber sheet. The thermally-insulating sheet further includes a protective sheet bonded onto the resin layer so as to cover the thermal insulator and to cover the surface of the fiber sheet. This thermally-insulating sheet hardly break even if having a large size.

A thermally-insulating sheet includes a thermal insulator which includes a fiber sheet made of fibers providing spaces among the fibers, a resin layer provided on a part of a surface of the fiber sheet, the first resin having a denser surface than the fiber sheet, and a silica xerogel held in the spaces of the fiber sheet. The thermally-insulating sheet further includes a protective sheet bonded onto the resin layer so as to cover the thermal insulator and to cover the surface of the fiber sheet. This thermally-insulating sheet hardly break even if having a large size.

An object is to provide a heat insulating sheet that is easily attachable even if a size is increased, and to provide a method for manufacturing the same. A heat insulating sheet includes nonwoven fabric, and heat insulating body carrying xerogel in a space inside nonwoven fabric. Heat insulating body includes first region carrying the xerogel, and second region not carrying the xerogel and provided inside an outer periphery of heat insulating body. The heat insulating sheet is configured such that each of both surfaces of heat insulating body is provided with protective sheet, and in a periphery of heat insulating body and in second region, protective sheets are mutually joined or protective sheets and second region are joined.

An insulating material is used that contains a silica xerogel, and a nonwoven fabric fiber capable of generating carbon dioxide by reacting with atmospheric oxygen at a temperature of 300 C. or more. The insulating material uses oxidized acrylic as the nonwoven fabric fiber. A device uses the insulating material installed as a part of a heat insulating or a cold insulating structure, or installed between a heat-generating part and a casing.

An insulating material is used that contains a silica xerogel, and a nonwoven fabric fiber capable of generating carbon dioxide by reacting with atmospheric oxygen at a temperature of 300 C. or more. The insulating material uses oxidized acrylic as the nonwoven fabric fiber. A device uses the insulating material installed as a part of a heat insulating or a cold insulating structure, or installed between a heat-generating part and a casing.

The present invention relates to an aerogel composite powder superior in thermal insulation and flexibility, the aerogel composite powder comprising an aerogel component and a silica particle.

The present invention relates to an aerogel composite powder superior in thermal insulation and flexibility, the aerogel composite powder comprising an aerogel component and a silica particle.

A method for producing silica aerogel according to the present invention includes: a solation step of generating a sol by adding monoalkyltrialkoxysilane to an acidic aqueous solution containing silicic acid; and a gelation step of generating a wet gel by gelating the sol. Moreover, the production method includes a drying step of removing a solvent, which is contained in the wet gel, from the wet gel by drying the wet gel at less than a critical temperature of the solvent and at less than a critical pressure of the solvent. Then, the monoalkyltrialkoxysilane is added to the acidic aqueous solution so that an amount of silicon in the monoalkyltrialkoxysilane becomes 1 mol part or more with respect to 1 mol part of an amount of silicon in the acidic aqueous solution containing the silicic acid.

A method for producing silica aerogel according to the present invention includes: a solation step of generating a sol by adding monoalkyltrialkoxysilane to an acidic aqueous solution containing silicic acid; and a gelation step of generating a wet gel by gelating the sol. Moreover, the production method includes a drying step of removing a solvent, which is contained in the wet gel, from the wet gel by drying the wet gel at less than a critical temperature of the solvent and at less than a critical pressure of the solvent. Then, the monoalkyltrialkoxysilane is added to the acidic aqueous solution so that an amount of silicon in the monoalkyltrialkoxysilane becomes 1 mol part or more with respect to 1 mol part of an amount of silicon in the acidic aqueous solution containing the silicic acid.