Provided is a hydrophobic silica aerogel blanket comprising holes, so that the diffusion of a surface modifier is facilitated in a blanket during a surface modification process to improve the efficiency of surface modification. Accordingly, the hydrophobic silica aerogel has not only excellent physical properties such as specific surface area and thermal conductivity, but also a controlled degree of hydrophobicity, and thus, can have high hydrophobicity.

Provided is a method for drying a wet-gel blanket which can have an excellent heat insulation performance by minimizing shrinkage of a gel network structure that occurs during drying, and has excellent drying efficiency versus time, and a method for producing an aerogel blanket using same.

Provided is a method for drying a wet-gel blanket which can have an excellent heat insulation performance by minimizing shrinkage of a gel network structure that occurs during drying, and has excellent drying efficiency versus time, and a method for producing an aerogel blanket using same.

A silica sol, a silica aerogel blanket using the same, and a method for manufacturing the same, wherein a hydrophobizing agent, a base catalyst, an organic solvent, and water are included in a catalyst composition when manufacturing the silica aerogel blanket, so that a wet aging step which is performed under high-temperature conditions and increases the amount of a solvent used, surface modification step which uses a large amount of an organic solvent and an expensive surface modifier, resulting in a process that is complex and long and thus inhibiting economic feasibility and productivity, can be omitted.

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.

Provided is an aerogel-containing heat insulation composite obtained by providing a volatile material to the pores of the aerogel, blending the aerogel with a polymer resin, particularly a flexible polymer resin, to form a composite, and removing the volatile material. Thus, it is possible to prevent a decline of the porosity of the aerogel caused by infiltration and impregnation of the pores of the aerogel with the resin. As a result, the aerogel-containing heat insulation composite, particularly containing a high content of aerogel, may retain the heat insulation property of the aerogel as well as the flexibility of the plastic material.

Provided is an aerogel-containing heat insulation composite obtained by providing a volatile material to the pores of the aerogel, blending the aerogel with a polymer resin, particularly a flexible polymer resin, to form a composite, and removing the volatile material. Thus, it is possible to prevent a decline of the porosity of the aerogel caused by infiltration and impregnation of the pores of the aerogel with the resin. As a result, the aerogel-containing heat insulation composite, particularly containing a high content of aerogel, may retain the heat insulation property of the aerogel as well as the flexibility of the plastic material.

A method for producing a silica aerogel includes a gelation step of adding a monoalkyltrialkoxysilane to an acidic aqueous solution containing a surfactant to prepare a sol, and then gelating the sol to prepare a wet gel. The method further includes a separation step of immersing the wet gel in a solvent mixture of a first solvent and a second solvent immiscible with the first solvent. The first solvent has an E.sub.T.sup.N value of 0.5 or less, and the second solvent has an E.sub.T.sup.N value between those of the first solvent and water. The method further includes a drying step of drying the wet gel at a temperature lower than a critical temperature of the first solvent under a pressure lower than a critical pressure of the first solvent to remove the first solvent from the wet gel.

A method for producing a silica aerogel includes a gelation step of adding a monoalkyltrialkoxysilane to an acidic aqueous solution containing a surfactant to prepare a sol, and then gelating the sol to prepare a wet gel. The method further includes a separation step of immersing the wet gel in a solvent mixture of a first solvent and a second solvent immiscible with the first solvent. The first solvent has an E.sub.T.sup.N value of 0.5 or less, and the second solvent has an E.sub.T.sup.N value between those of the first solvent and water. The method further includes a drying step of drying the wet gel at a temperature lower than a critical temperature of the first solvent under a pressure lower than a critical pressure of the first solvent to remove the first solvent from the wet gel.