US4436823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silica gels incorporating insolubilized reagents
Assignee: Draegerwerk AG and Co KGaA
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Filing: 1981-05-26
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Granted: 1984-03-13
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Expires: 2001-05-26
Abstract
Abstract A dried silica gel containing a reagent in insolubilized form which reagent is normally soluble, especially a dried silica gel containing an insolubilized form of a normally soluble colorimetric analytical agent and a method of preparing such dried silica gel by hydrolyzing a silane having from 1 to 4 alkoxy groups in a homogeneous phase in the presence of a reagent which is normally soluble in a solvent, recovering the resultant gel and drying the same.
Inventors
- 👤 Alfred Blumcke
- 👤 Peter Fischer
- 👤 Hans-Joachim Vahlensieck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:21
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/103; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/52; Y; Y10; Y10T; Y10T436/00; Y10T436/10
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
44 words
A composition consisting essentially of a dried silica gel containing in insolubilized form a normally soluble reagent which retains it reactivity, said reagent being uniformly absorbed in and throughout said silica gel, said reagent being insoluble to solvents in which it is normally soluble.
Claim 2
Dependent Claim
44 words
A composition consisting essentially of a dried silica gel containing in insolubilized form a normally soluble reagent which retains it reactivity, said reagent being uniformly absorbed in and throughout said silica gel, said reagent being insoluble to solvents in which it is normally soluble.
Claim 3
Dependent Claim
57 words
A composition according to claim 1 wherein said reagent is uniformly absorbed in and throughout said silica gel and is present in sufficient concentration that it reacts with reagents with which it normally reacts uniformly, said reagent being present in an amount of 0.5 to 5 percent by weight based upon the weight of said silica gel.
Claim 4
Dependent Claim
17 words
A composition according to claim 2 wherein said reagent is bound to said silica gel by hydrolysis.
Claim 5
Dependent Claim
14 words
A composition according to claim 1 wherein said reagent is a colorimetric analytical reagent.
Claim 6
Dependent Claim
25 words
A composition according to claim 4 wherein said analytical reagent is one which reacts with a metal in a test solution with evolution of color.
Claim 7
Dependent Claim
14 words
A composition according to claim 5 wherein said analytical reagent is an organic compound.
Claim 8
Dependent Claim
14 words
A composition according to claim 5 wherein said analytical reagent is an inorganic compound.
Claim 9
Dependent Claim
14 words
A composition according to claim 5 wherein said analytical reagent is an organometallic compound.
Claim 10
Dependent Claim
20 words
A composition according to claim 5 wherein said analytical reagent is an alizarin, a rhodamine, an anthraquinone, benzidene or brucine.
Claim 11
Dependent Claim
24 words
A composition according to claim 5 wherein said analytical reagent is the disodium salt of rhodizonic acid, 2,2'-bipyridine, dimethylglyoxime, diphenyl carbazide, α-benzoinoxime or salicylaldoxime.
Claim 12
Dependent Claim
25 words
A composition according to claim 5 wherein said analytical reagent is an alkali rhodanide, a complex iron cyanide, an alkali sulfide, or an ammonium molybdate.
Claim 13
Dependent Claim
43 words
A composition according to claim 5 wherein said analytical reagent is organometallic compound of the formula (RO).sub.3 Si(CH.sub.2).sub.n SH or (RO).sub.3 Si(CH.sub.2).sub.n NH.sub.2 where R is a C 1 to C 4 alkyl radical and n has a value between 1 and 4.
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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) | 1987-03-13 | 1987-09-12 | 1988-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-13 | 1991-09-12 | 1992-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-13 | 1995-09-12 | 1996-03-13 | $7700.00 | Window Closed / Lapsed |