Economically viable process for producing organically modified lyo- or aerogels

Patent metadata

Field	Value
Publication number	US-10766779-B2
Application number	US-201615513064-A
Country	US
Kind code	B2
Filing date	Jun 20, 2016
Priority date	Jun 25, 2015
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

Abstract

It is an object of the invention to provide a rapid and economically viable process which is notable for efficient use of material, especially of the silylating agent, and by means of which organically modified lyo- or aerogels are obtained in a rapid and simple manner. This object is achieved by virtue of the invention providing a process for producing organically modified gels selected from lyo- and aerosols by (i) emulsifying a basic polar phase comprising water and starting materials for silicatic gels in a nonpolar phase containing a water-immiscible precursor for an active silylating agent, (ii) starting formation of gel and ageing by lowering the pH, and then (iii) starting the silylation and the exchange of solvent by lowering the pH. If the gels are aerogels, the gels provided can be used for thermal and/or acoustic insulation.

First claim

The invention claimed is:

1. A process for producing lyogels or aerogels, said process comprising the following steps
i) emulsifying a basic, polar phase comprising water and starting materials for silicatic gels in an apolar phase consisting of a water-immiscible precursor of an active silylating agent,
ii) commencing gel formation and aging by lowering a pH, and then
iii) lowering the pH to commence silylation and solvent exchange.

2. A process for producing lyogels or aerogels, said process comprising the following steps
i) emulsifying a basic, polar phase comprising water and starting materials for silicatic gels in an apolar phase comprising a water-immiscible precursor of an active silylating agent,
ii) commencing gel formation and aging by lowering a pH with a chlorosilane, and then
iii) lowering the pH to commence silylation and solvent exchange.

3. A process for producing lyogels or aerogels, said process comprising the following steps
i) emulsifying a basic, polar phase comprising water and starting materials for silicatic gels in an apolar phase consisting of a water-immiscible precursor of an active silylating agent,
ii) commencing gel formation and aging by lowering a pH, and then
iii) lowering the pH to commence silylation and solvent exchange, and
iv) recovering the water-immiscible precursor of the active silylating agent which remains unreacted in the apolar phase,
wherein (a) disiloxanes or mixtures thereof are used as the water-immiscible precursor of an active silylating agent, (b) the basic, polar phase is produced by mixing individual components in the apolar phase, and (c) there is a phase mediator in the basic, polar phase.

4. The process as claimed in claim 3 , wherein the basic, polar phase comprises a mixture of the starting materials for [SiO 4/2 ] and [R x SiO (4-x/2) ] units where x=1 or 2 or mixtures thereof and R is identical or different and is hydrogen or an organic, substituted or unsubstituted radical.

5. The process as claimed in claim 3 , wherein hexamethyldisiloxane is used as the water-immiscible precursor of an active silylating agent.

6. The process as claimed in claim 3 , wherein a mineral acid is used in step ii) for lowering the pH.

7. The process as claimed in claim 6 , wherein the mineral acid used for lowering the pH in step ii) is also used in step iii) to lower the pH.

8. The process as claimed in claim 3 , further comprising drying to provide aerogels.

9. The process as claimed in claim 3 , wherein a chlorosilane is used in step ii) for lowering the pH.

Assignees

• Wacker Chemie Ag

Inventors

• Jantke Dominik
• Hindelang Konrad
• Weidner Richard

Classifications

• C01B33/166

  by acidification of silicate in the presence of an inert organic phase · CPC title

• C01B33/163

  by hydrolysis of organosilicon compounds, e.g. ethyl orthosilicate · CPC title

• C01B33/1585

  Dehydration into aerogels · CPC title

• C01B33/155 Primary

  Preparation of hydroorganogels or organogels · CPC title

• C01B33/158 Primary

  Purification; Drying; Dehydrating · CPC title