Method for preparing silica aerogel-containing blanket and silica aerogel-containing blanket prepared by using the same
In the present invention are provided a method for preparing a silica aerogel-containing blanket, and a blanket which includes a silica aerogel and is manufactured using the same, wherein the method includes a step for preparing a reaction solution by reacting a silazane-based surface modification agent with an alcohol-based compound, a step for preparing a silica gel-base material composite by adding a silica precursor, water, and a polar organic solvent to the reaction solution to prepare a silica sol, and then immersing a base material for a blanket in the prepared silica sol to gelate the silica sol, and a step for drying the silica gel-base material composite.
1. A method for preparing a silica aerogel-containing blanket, comprising:
a step for preparing a reaction solution including an alkoxysilane-based compound produced by decomposition of a silazane-based surface modification agent and an alcohol-based compound by reacting the silazane-based surface modification agent with the alcohol-based compound;
a step for preparing a silica gel-base material composite by adding a silica precursor, water, and a polar organic solvent to the reaction solution to prepare a silica sol, and then immersing a base material for a blanket in the prepared silica sol to gelate the silica sol; and
a step for drying the silica gel-base material composite.
2. The method of claim 1 , wherein the silazane-based surface modification agent comprises a compound of Formula 1 below,
wherein R 11 to R 13 and R 21 to R 23 are each independently a hydrogen atom or an alkyl group having a 1 to 8 carbon atoms, with the proviso that R 11 to R 13 and R 21 to R 23 are not simultaneously hydrogen atoms.
3. The method of claim 1 , wherein:
the silazane-based surface modification agent comprises one or a mixture of two or more selected from the group consisting of tetraalkyldisilazane and hexaalkyldisilazane; and
the alkyl is an alkyl having 1 to 4 carbon atoms.
4. The method of claim 1 , wherein the alcohol-based compound is an alcohol having 1 to 8 carbon atoms.
5. The method of claim 1 , wherein an acid catalyst is further added during the preparation of the reaction solution.
6. The method of claim 1 , wherein the silica precursor comprises one or a mixture of two or more selected from the group consisting of silicon alkoxide-based compounds and pre-hydrolysis products thereof.
7. The method of claim 1 , wherein the silica precursor comprises a pre-hydrolysis product of a tetraalkyl silicate having a degree of hydration of 50 to 90%.
8. The method of claim 1 , wherein the silica precursor is used in such an amount that the content of silica in the silica sol is 0.1 to 30 wt %.
9. The method of claim 1 , wherein the water is used in a ratio of 0.1 to 16 mol per 1 mol of silica included in the silica sol.
10. The method of claim 1 , wherein the polar organic solvent includes an alcohol-based solvent.
11. The method of claim 1 , wherein a base is further added during the preparation of the silica sol.
12. The method of claim 1 , which further comprises a step for performing on the silica gel-base material composite, one or two or more processes selected from the group consisting of a stabilization process, a pre-aging process, and an aging process, prior to the drying of the silica gel-base material composite.
13. The method of claim 1 , which further comprises a process for aging the silica gel-base material composite at a temperature of 50 to 80° C., prior to the drying of the silica gel-base material composite.
14. The method of claim 1 , wherein the drying is performed by a supercritical drying process.
15. The method of claim 1 , which comprises:
a step for preparing a reaction solution comprising an alkoxysilane-based compound produced by a decomposition reaction of the alkoxysilane-based surface modification agent and the alcohol-based compound by reacting the silazane-based surface modification agent of Formula 1 below with an alcohol-based compound;
a step for preparing a silica gel-base material composite by adding a silica precursor, water, a linear alcohol having a 1 to 4 carbon atoms as a polar organic solvent, and a base to prepare a silica sol, and then immersing a base material for a blanket in the prepared silica sol to gelate the silica sol;
a step for performing an aging process in which the silica gel-base material composite is maintained at a temperature of 50 to 80° C.; and
a step for supercritically drying the aged silica gel-base material composite,
wherein R 11 to R 13 and R 21 to R 23 are each independently a hydrogen atom or an alkyl group having a 1 to 8 carbon atoms, and R 11 to R 13 and R 21 to R 23 are not simultaneously hydrogen atoms.