US 6,855,335 B2 · Process for preparing silica microcapsules

Abstract

The present invention relates to a process for preparing silica microcapsules and more particularly, to a process for preparing silica microcapsules comprising the steps of dissolving tetraethyl orthosilicate (TEOS) into an aqueous solution containing a hydrolysis catalyst to control a degree of hydrolysis and contribute hydrophilicity or lipophilicity, adding a core material and an appropriate amount of aminopropyltrialkoxysilane(APS) as a gelling agent into the solution, and emulsifying and dispersing the resulting solution to a solution having a polarity opposite to that of the core material to microcapsulate by coating the core material with silica shell via a sol-gel reaction. The process for preparing microcapsules of the present invention reduces environmental pollution compared to conventional processes using an alkali gelling agent such as an ammonia solution, and are suitable for both organic or inorganic core materials having hydrophilic or lipophilic property.

Claims6

Dependent claims

A process for preparing silica microcapsules comprising the steps of:

preparing a precursor solution containing a compound of formula (1) by adding tetraethyl orthosilicate in an aqueous solution containing a hydrolysis catalyst;
adding a core material and aminopropyltriepoxysilane into the precursor solution;
and
emulsifying and dispersing the resulting solution into a solution having a polarity opposite to that of the core material to perform a sol-gel reaction at the interface thus impregnating the core material,
(OH)3−x(RO)x—Si—O—[Si—O—Si]n—Si—(RO)x(OH)3−x (1)
wherein R is a C1 to C10 alkyl group, x is 1, 2 or 3, and n is an integer of 100 to 1,200.

3 more elements

Dependencies are inferred from the claim text.

Process for preparing silica microcapsules

Life of this patent

Process for preparing silica microcapsules

Life of this patent

Abstract

Claims6