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.

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.

It is an object of the invention to provide an economically viable process for the production of hydrophobized aerogels which works both inexpensively and in a resource-conserving manner. 2.2. This object is achieved by the provision of a process for producing organically modified aerogels by producing a sol containing [SiO.sub.4/2] units and [R.sub.xSiO.sub.(4X)/2] a units, where x may be the same or different and is 1, 2 or 3, and R may be the same or different and is hydrogen or an organic substituted or unsubstituted radical, using the sol to form a gel, surface-modifying the gel obtained in the presence of more than 0.1% by weight of a phase modifier in a mixture comprising organosiloxane and initiator, wherein the mixture contains at least 20% by weight of organosiloxane and wherein the initiator consists of acid or organosiloxane or mixtures thereof and the gels obtained are dried. 2.3. The aerogels provided can be used as insulating materials, especially in thermal insulation.

A method for preparing a novel hydrogel including silico-metallic mineral particles of the formula (Si.sub.x(Si-A).sub.1x).sub.4M.sub.3O.sub.11.nH.sub.2O, in which: x is a real number in the range [0.75; 1], A denotes a group selected from methyl and hydrocarbon groups including at least one heteroatom, and M is a metal selected from the group consisting of magnesium, cobalt, zinc, copper, manganese, iron, nickel and chromium, wherein a coprecipitation reaction is carried out in an aqueous medium between: at least one metal salt of the metal M, sodium metasilicate, Na.sub.2OSiO.sub.2, and at least one water-soluble oxysilane of formula (I): ##STR00001## in which R1, R2 and R3 are selected from hydrogen and linear alkyl groups including 1 to 3 carbon atoms.

A method for preparing a novel hydrogel including silico-metallic mineral particles of the formula (Si.sub.x(Si-A).sub.1x).sub.4M.sub.3O.sub.11.nH.sub.2O, in which: x is a real number in the range [0.75; 1], A denotes a group selected from methyl and hydrocarbon groups including at least one heteroatom, and M is a metal selected from the group consisting of magnesium, cobalt, zinc, copper, manganese, iron, nickel and chromium, wherein a coprecipitation reaction is carried out in an aqueous medium between: at least one metal salt of the metal M, sodium metasilicate, Na.sub.2OSiO.sub.2, and at least one water-soluble oxysilane of formula (I): ##STR00001## in which R1, R2 and R3 are selected from hydrogen and linear alkyl groups including 1 to 3 carbon atoms.

The silica sol of the invention contains silica particles having a mean primary particle size of 20 to 100 nm and which has a silica particle size/mean primary particle size ratio, determined through dynamic light scattering, of 3.0 or less, wherein the silica particles are surface-treated with an organic silane compound and have an -ray emission rate of 0.005 counts/cm.sup.2.Math.hr or less and a moisture absorption coefficient, determined after allowing the silica particles to stand for 48 hours at 23 C. and a relative humidity of 50 RH %, of 0.5 mass % or lower.

The silica sol of the invention contains silica particles having a mean primary particle size of 20 to 100 nm and which has a silica particle size/mean primary particle size ratio, determined through dynamic light scattering, of 3.0 or less, wherein the silica particles are surface-treated with an organic silane compound and have an -ray emission rate of 0.005 counts/cm.sup.2.Math.hr or less and a moisture absorption coefficient, determined after allowing the silica particles to stand for 48 hours at 23 C. and a relative humidity of 50 RH %, of 0.5 mass % or lower.

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.

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