Patent US4871701A successfully refreshed from Google Patents.
US4871701A
Expired / Lapsed
US
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Alkali-free preparation of large pentasil crystals as coated catalysts and fully crystalline catalysts
Assignee: BASF SE
•
Filing: 1988-08-24
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Granted: 1989-10-03
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Expires: 2008-08-24
Abstract
Abstract Pentasil coated catalysts and fully crystalline catalysts in which the individual pentasil crystals are larger than 5 μm are prepared by hydrothermal treatment of SiO 2 by a process in which the SiO 2 moldings are subjected to a hydrothermal treatment at from 140° to 220° C. in an alkali-free mixture of water, an amine and/or a tetraalkylammonium compound, with or without ammonia. The aluminum component for the preparation of an aluminosilicate zeolite can be kneaded into the SiO 2 moldings or fed in via the liquid phase during the hydrothermal treatment. The tetraalkylammonium compound used can be a tetra-n-propyl-ammonium salt or hydroxide.
Inventors
- 👤 Alfred Danner
- 👤 Ulaich Mueller
- 👤 Klaus Unger
- 👤 Wolfgang Hoelderich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:51
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/40; C; C01; C01B; C01B39/00; C01B39/02; C01B39/36; C01B39/38; C01B39/40; C07; C07C; C07C45/00; C07C45/51; C07C45/511; C07C45/515; C07C45/56; C07C45/57; C07C45/58; C07C45/61; C07C45/65; C07C45/66
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
68 words
A process for the alkali-free preparation of large pentasil crystals as coated catalysts and fully crystalline catalysts, in which the individual pentasil crystals are larger than 5 μm, by hydrothermal treatment of SiO 2 , wherein the SiO 2 moldings are subjected to a hydrothermal treatment at from 140° to 220° C. in an alkali-free mixture of water, an amine and/or a tetraalyklammonium compound, with or without ammonia.
Claim 2
Dependent Claim
68 words
A process for the alkali-free preparation of large pentasil crystals as coated catalysts and fully crystalline catalysts, in which the individual pentasil crystals are larger than 5 μm, by hydrothermal treatment of SiO 2 , wherein the SiO 2 moldings are subjected to a hydrothermal treatment at from 140° to 220° C. in an alkali-free mixture of water, an amine and/or a tetraalyklammonium compound, with or without ammonia.
Claim 3
Dependent Claim
25 words
A process as claimed in claim 1, wherein the aluminum component for the preparation of an aluminosilicate zeolite is kneaded into the SiO 2 moldings.
Claim 4
Dependent Claim
29 words
A process as claimed in claim 1, wherein the aluminum component for the preparation of an aluminosilicate zeolite is fed in via the liquid phase during the hydrothermal treatment.
Claim 5
Dependent Claim
18 words
A process as claimed in claim 1, wherein the tetraalkylammonium compound used is a tetra-n-propylammonium salt or hydroxide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-02 | 1993-04-03 | 1993-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-02 | 1997-04-03 | 1997-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-02 | 2001-04-03 | 2001-10-03 | $7700.00 | Window Closed / Lapsed |