US3922392A
Expired / Lapsed
US
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Process for coating nonporous material with a porous silicon dioxide layer
Assignee: Merck Patent GmbH
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Filing: 1973-05-25
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Granted: 1975-11-25
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Expires: 1993-05-25
Abstract
Abstract Nonporous materials are coated with a porous silicon dioxide layer by coating the nonporous material with a polymeric alkoxysiloxane and then subjecting this coating to a hydrolytic polycondensation with an aqueous basic solution. The thusobtained product is then dried.
Inventors
- 👤 Hans Wolfgang Kohlschutter
- 👤 Klaus Unger
- 👤 Jurgen Schick-Kalb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:54
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/30; B01J20/32; B01J20/3231; B01J20/3234; B01J20/281; B01J20/282; B01J20/283; B01J20/286; B01J20/3202; B01J20/3204; B01J20/3291; B01J20/3293; B01J20/3295; B05; B05D; B05D7/00; C; C03; C03C; C03C17/00; C03C17/22; C03C17/23; C03C17/25; B05D2201/00; B05D2201/02; B05D2202/00; B05D2202/20; B05D2202/25; B05D2203/00; B05D2203/30; B05D2203/35; B05D2518/00; B05D2518/10; B05D2518/12; C03C2217/00; C03C2217/20; C03C2217/21; C03C2217/213; C03C2218/00; C03C2218/10; C03C2218/11; C03C2218/111
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
130 words
A PROCESS FOR COATING A NONPOROUS MATERIAL WITH A PROUS SILICON DIOXIDE LAYER SUITABLE FOR USE IN CHROMATOGRAPHY, WHICH COMPRISES: A. COATING SAID NONPOROUS MATERIAL WITH A PREFORMED POLYMERIC TETRAALKOXYSILOXANE CONSISTING ESSENTIALLY OF ALKOXY GROUPS AND CROSS-LINKED SILOXANE GROUPS, HAVING A MOLECULAR WEIGHT OF ABOUT 1,000-5,000 AND A KINEMATIC VISCOSITY OF 100-500 CENTISTOKES TO FROM A THIN, UNIFORM COATING THEREON; AND B. SUBJECTING THE RESULTANT COATED MATERIAL TO HYDROLYTIC POLYCONDENSATION BY TREATMENT WITH AN AQUEOUS SOLUTION HAVING A HYDROXYL ION CONCENTRATION OF 1X10**3 TO 1.5 MOLES PER MOLE OF SIO2 IN THE POLYALKOXYSILOXANE EMPOLYED, SAID AQUEOUS SOLUTION CONSISTING ESSENTIALLY OF WATER AND A BASIC COMPOUND, TO PRODUCE A LAYER OF POROUS, POLYMERIC SILICON DIXOIDE HYDROGEL THEREON HAVING A THICKNESS OF 0.1 -100$ AND AN AVERAGE PORE DIAMETER OF 30-800 A.
Claim 2
Dependent Claim
130 words
A PROCESS FOR COATING A NONPOROUS MATERIAL WITH A PROUS SILICON DIOXIDE LAYER SUITABLE FOR USE IN CHROMATOGRAPHY, WHICH COMPRISES: A. COATING SAID NONPOROUS MATERIAL WITH A PREFORMED POLYMERIC TETRAALKOXYSILOXANE CONSISTING ESSENTIALLY OF ALKOXY GROUPS AND CROSS-LINKED SILOXANE GROUPS, HAVING A MOLECULAR WEIGHT OF ABOUT 1,000-5,000 AND A KINEMATIC VISCOSITY OF 100-500 CENTISTOKES TO FROM A THIN, UNIFORM COATING THEREON; AND B. SUBJECTING THE RESULTANT COATED MATERIAL TO HYDROLYTIC POLYCONDENSATION BY TREATMENT WITH AN AQUEOUS SOLUTION HAVING A HYDROXYL ION CONCENTRATION OF 1X10**3 TO 1.5 MOLES PER MOLE OF SIO2 IN THE POLYALKOXYSILOXANE EMPOLYED, SAID AQUEOUS SOLUTION CONSISTING ESSENTIALLY OF WATER AND A BASIC COMPOUND, TO PRODUCE A LAYER OF POROUS, POLYMERIC SILICON DIXOIDE HYDROGEL THEREON HAVING A THICKNESS OF 0.1 -100$ AND AN AVERAGE PORE DIAMETER OF 30-800 A.
Claim 3
Dependent Claim
24 words
A process according to claim 1, wherein the coating of the nonporous material is conducted in the presence of a readily volatile organic solvent.
Claim 4
Dependent Claim
13 words
A process according to claim 1, wherein the basic compound is ammonium hydroxide.
Claim 5
Dependent Claim
12 words
A process according to claim 1, wherein the nonporous material is particulate.
Claim 6
Dependent Claim
13 words
A process according to claim 3, wherein the nonporous material is glass microspheres.
Claim 7
Dependent Claim
17 words
A process according to claim 5, wherein the glass spheres have an average diameter of 30-40 microns.
Claim 8
Dependent Claim
29 words
A process according to claim 1, wherein the pores of the thus-produced porous coating are increased by contacting the porous coated material with hot water after the hydrolytic polycondensation.
Claim 9
Dependent Claim
13 words
A process according to claim 7, wherein the non-porous material is glass microspheres.
Claim 10
Dependent Claim
13 words
A process according to claim 8, wherein the basic compound is ammonium 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) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |