Provided is a hydrophobic silica powder that can be obtained by the sol-gel process, and that is excellent in charge properties. The hydrophobic silica powder has a hydrophobicity of 50% or more, a saturated water content of 4% or less, and a nitrogen content of 0.05% or more.

The present invention relates to a method for manufacturing an aerogel sheet. The method for manufacturing an aerogel sheet includes: a step (a) of preparing silica sol; a step (b) of preparing a gelling catalyst; a step (c) of injecting the silica sol, which is prepared in the step (a), to a surface of a blanket to impregnate the silica sol; and a step (d) of injecting the gelling catalyst, which is prepared in the step (b), to the surface of the blanket, into which the silica sol is impregnated, to gelate the silica sol.

The present invention relates to a method for manufacturing an aerogel sheet. The method for manufacturing an aerogel sheet includes: a step (a) of preparing silica sol; a step (b) of preparing a gelling catalyst; a step (c) of injecting the silica sol, which is prepared in the step (a), to a surface of a blanket to impregnate the silica sol; and a step (d) of injecting the gelling catalyst, which is prepared in the step (b), to the surface of the blanket, into which the silica sol is impregnated, to gelate the silica sol.

A method for manufacturing an aerogel blanket, the method capable of simplifying manufacturing equipment by performing gelation while rotating a reaction vessel, improving manufacturing efficiency by controlling manufacturing time regardless of the thickness of an aerogel blanket and improving thermal conductivity by uniformly forming an aerogel in a substrate for blanket.

A method for manufacturing an aerogel blanket, the method capable of simplifying manufacturing equipment by performing gelation while rotating a reaction vessel, improving manufacturing efficiency by controlling manufacturing time regardless of the thickness of an aerogel blanket and improving thermal conductivity by uniformly forming an aerogel in a substrate for blanket.

The problem addressed by the invention is that of producing aerogels which have as high and permanent a hydrophobicity as possible and which have a reduced combustibility, that is as low a carbon content as possible, and are simultaneously less rigid and brittle than known systems, i.e. which with reduced combustibility have a high flexibility and high stability at the same time, that is high mechanical load-bearing capacity. Said problem is solved in that the invention provides gels chosen from lyogel or aerogel, which are synthesised from oxide units and [R.sub.xSiO.sub.(4-x)/2] units, wherein the primary particles have a change of concentration in [R.sub.xSiO.sub.(4-x)/2] units from the inside to the outside, wherein x can be the same or different and is 1 or 2, and R can be the same or different and is hydrogen or an organic substituted or unsubstituted radical, and wherein the oxide units contain [SiO.sub.4/2] units, and a method for producing same. The gels provided can be used in cosmetic, medical or for chromatographic applications, and as a catalyst or catalyst support. If the gels are aerogels, same are preferably used for thermal and/or acoustic insulation.

The problem addressed by the invention is that of producing aerogels which have as high and permanent a hydrophobicity as possible and which have a reduced combustibility, that is as low a carbon content as possible, and are simultaneously less rigid and brittle than known systems, i.e. which with reduced combustibility have a high flexibility and high stability at the same time, that is high mechanical load-bearing capacity. Said problem is solved in that the invention provides gels chosen from lyogel or aerogel, which are synthesised from oxide units and [R.sub.xSiO.sub.(4-x)/2] units, wherein the primary particles have a change of concentration in [R.sub.xSiO.sub.(4-x)/2] units from the inside to the outside, wherein x can be the same or different and is 1 or 2, and R can be the same or different and is hydrogen or an organic substituted or unsubstituted radical, and wherein the oxide units contain [SiO.sub.4/2] units, and a method for producing same. The gels provided can be used in cosmetic, medical or for chromatographic applications, and as a catalyst or catalyst support. If the gels are aerogels, same are preferably used for thermal and/or acoustic insulation.

A method for manufacturing an aerogel sheet according to the present invention includes: a step (a) of preparing a blanket having a plate shape; a step (b) of mixing silica sol with gelling catalyst to prepare a silica sol precursor; and a step (c) of injecting the silica sol precursor prepared in the step (b) to a surface of the blanket prepared in the step (a) through an injection device to gelate the silica sol precursor, wherein, in the step (c), the injection device injects the silica sol precursor while moving from one side to the other side of the surface of the blanket.

A method for manufacturing an aerogel sheet according to the present invention includes: a step (a) of preparing a blanket having a plate shape; a step (b) of mixing silica sol with gelling catalyst to prepare a silica sol precursor; and a step (c) of injecting the silica sol precursor prepared in the step (b) to a surface of the blanket prepared in the step (a) through an injection device to gelate the silica sol precursor, wherein, in the step (c), the injection device injects the silica sol precursor while moving from one side to the other side of the surface of the blanket.

Provided is a method for producing a silica aerogel blanket and an apparatus for producing the same, which are capable of easily controlling the physical properties of a silica aerogel blanket by separately injecting silica sol and a gelation catalyst to control gelation time, improving aerogel pore structure to be uniform and improving thermal insulation performance by sufficiently and uniformly impregnating the silica sol and the gelation catalyst into a blanket, reducing the loss of silica sol and gelation catalyst by allowing the silica sol and the gelation catalyst to pass on an ascending slope before gelation to remove any excessive silica sol and gelation catalyst exceeding an appropriate impregnation amount, and providing a silica aerogel blanket having less process trouble, and less dust.