Process for the preparation of modified aerogels, and their use
First Claim
1. A process for the preparation of aerogels in whicha) a silicatic lyogel is prepared,b) if desired, the lyogel prepared in step a) is subjected to a solvent exchange with another organic solvent,c) the gel obtained in step a) or b) is reacted with at least one silylating agent, andd) the silylated gel obtained in step c) is dried subcritically, which comprises, in step c), reacting the gel obtained in step a) or b) with at least one chlorine-free silylating agent of the formula I, ##STR4## wherein each R1 is identical or different and is selected from the group consisting of linear C1 -C6 -alkyl radicals, branched C1 -C6 -alkyl radicals, cyclohexyl radicals and phenyl radicals;
- R2, R3 and R4 are identical or different and selected from the group consisting of hydrogen atoms, linear C1 -C6 -alkyl radicals, branched C1 -C6 -alkyl radicals, cyclohexyl radicals and phenyl radicals;
and n=1, 2 or 3.
3 Assignments
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Accused Products
Abstract
The invention relates to a process for the production of modified SiO2 aerogels in which
a) a silicatic lyogel is prepared,
b) if desired, the lyogel prepared in step a) is subjected to a solvent exchange with another organic solvent,
c) the gel obtained in step a) or b) is reacted with at least one chlorine-free silylating agent, and
d) the gel obtained in step c) is dried subcritically,
wherein the chlorine-free silylating agent is a compound of the formula I ##STR1## wherein each R1 is identical or different and is selected from a group consisting of linear C1 -C6 -alkyl radicals, branched C1 -C6 -alkyl radicals, cyclohexyl radicals and phenyl radicals,
R2, R3 and R4 are identical or different and are selected from the group consisting of hydrogen atoms, linear C1 -C6 -alkyl radicals, branched C1 -C6 -alkyl radicals, cyclohexyl radicals and phenyl radicals;
and n=1, 2 or 3.
41 Citations
13 Claims
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1. A process for the preparation of aerogels in which
a) a silicatic lyogel is prepared, b) if desired, the lyogel prepared in step a) is subjected to a solvent exchange with another organic solvent, c) the gel obtained in step a) or b) is reacted with at least one silylating agent, and d) the silylated gel obtained in step c) is dried subcritically, which comprises, in step c), reacting the gel obtained in step a) or b) with at least one chlorine-free silylating agent of the formula I, ##STR4## wherein each R1 is identical or different and is selected from the group consisting of linear C1 -C6 -alkyl radicals, branched C1 -C6 -alkyl radicals, cyclohexyl radicals and phenyl radicals; -
R2, R3 and R4 are identical or different and selected from the group consisting of hydrogen atoms, linear C1 -C6 -alkyl radicals, branched C1 -C6 -alkyl radicals, cyclohexyl radicals and phenyl radicals; and n=1, 2 or 3. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification
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- Resources
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Current AssigneeCabot Corporation
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Original AssigneeHoechst Aktiengesellschaft (Sanofi )
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InventorsZimmermann, Andreas, Schwertfeger, Fritz
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Primary Examiner(s)Lovering, Richard D.
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Assistant Examiner(s)Metzmaier, Daniel S.
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Application NumberUS08/894,040Time in Patent Office614 DaysField of Search252/315.2, 252/315.6, 501/12, 423/338, 428/405, 427/219, 427/220, 502/233US Class Current427/220CPC Class CodesC01B 33/16 Preparation of silica xerogelsC04B 14/064 Silica aerogelY10T 428/2995 Silane, siloxane or silicon...
