Preparation method of silica layer

1. A method for preparing a silica layer, comprising:

preparing a precursor composition comprising a silica precursor, an acid catalyst and a surfactant;

forming a precursor layer by using the precursor composition; and

bringing to gelation the precursor layer,

wherein the gelation is performed by contacting the precursor layer with a liquid phase Lewis base, and

wherein the gelation is performed at a temperature of 100° C.or lower and performed for 1 to 20 minutes.

2. The method according to claim 1 , wherein the silica precursor is a silane compound of the following formula D or E, a hydrolysate of the silane compound or a condensation reaction product of the silane compound:

SiR 1 (4-n) (OR 2 ) n   [Formula D]

wherein:

R 1 is hydrogen, an alkyl group, an alkenyl group, an aryl group, an arylalkyl group, an epoxy group, or a (meth)acryloyloxyalkyl group;

R 2 is an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a hydrogen atom; and

n is 3 or 4,

wherein:

L is a divalent linking group selected from the group consisting of an alkylene group and an arylene group, or a combination of two or more thereof; and

R 3 to R 8 are each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a hydrogen atom.

3. The method according to claim 1 , wherein the precursor composition comprises a silica precursor in a ratio ranging from 5 to 60 wt %.

4. The method according to claim 1 , wherein the precursor composition further comprises a solvent.

5. The method according to claim 4 , wherein the solvent is a mixed solvent of an aqueous solvent and an organic solvent.

6. The method according to claim 1 , wherein the surfactant forms micelles in the precursor layer or the precursor composition.

7. The method according to claim 1 , wherein the precursor composition further comprises a solvent and the concentration of the surfactant is adjusted to be in a range of 1 to 5 times the critical micelle concentration for the solvent.

8. The method according to claim 1 , wherein the surfactant is a cationic surfactant, an anionic surfactant or a nonionic surfactant.

9. The method according to claim 1 , wherein the gelation comprises contacting the precursor layer with an amine compound having a pKa of 8 or less.

10. The method according to claim 1 , wherein the precursor composition further comprises a latent base generator and the gelation comprises generating a base from the latent base generator.

11. The method according to claim 10 , wherein the latent base generator is a compound of the following formula 11 or is an ionic compound having a cationic compound of one of the following Formulas 13 to 15 or one which is contained in a compound of the following Formula 18 or derived therefrom:

wherein R 9 is hydrogen, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 12 carbon atoms; R 11 and R 12 are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms; and R 10 is hydrogen, an alkyl group having 1 to 4 carbon atoms, an arylalkyl group having 7 to 16 carbon atoms or a substituent of the following formula 12:

wherein L 1 is an alkylene group having 1 to 4 carbon atoms,

wherein R 13 to R 20 are each independently hydrogen or an alkyl group having 1 to 20 carbon atoms,

wherein R 21 to R 24 are each independently hydrogen or an alkyl group having 1 to 20 carbon atoms,

wherein R 25 to R 30 are each independently hydrogen or an alkyl group having 1 to 20 carbon atoms,

wherein R 31 and R 32 are each independently hydrogen, a linear or branched alkyl group having 1 to 4 carbon atoms or a cyclic alkyl group having 4 to 8 carbon atoms, or R 31 and R 32 are linked to each other to form a nitrogen-containing heterocyclic structure together with the nitrogen atom to which R 31 and R 32 are linked; Ar is an aryl group; and L 2 is -L 3 -O— or an alkenyl group having 2 to 4 carbon atoms, wherein L 3 is an alkylene group having 1 to 4 carbon atoms or an alkylidene group having 1 to 4 carbon atoms.

12. The method according to claim 1 , further comprising removing the surfactant after the gelation process.

13. The method according to claim 12 , wherein removal of the surfactant is performed using an alcohol solvent, a ketone solvent or an acetate solvent.

14. The method according to claim 1 , wherein the gelation of the precursor layer proceeds on a base material.

15. The method according to claim 14 , wherein the base material is any one functional layer selected from the group consisting of a high-refraction layer, a hard coating layer, an antireflection layer, a polarizing film, a protective film of a polarizing film, a luminance enhancement film, a retardation film, a display panel and a touch panel.