US3936388A
Expired / Lapsed
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Process for the production of silicon dioxide ion exchangers
Assignee: Merck Patent GmbH
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Filing: 1973-05-25
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Granted: 1976-02-03
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Expires: 1993-05-25
Abstract
Abstract An improved process for the production of silicon dioxide ion exchangers, which comprises the step of reacting silicon dioxide with benzyltrichlorosilane, in the absence of solvent and air, followed by hydrolysis, to produce a benzylated silicon dioxide whose benzyl groups can then be substituted with ion exchange reactive groups in a conventional manner.
Inventors
- 👤 Klaus Unger
- 👤 Karlheinz Berg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:31
CPC Classifications
B; B01; B01J; B01J41/00; B01J41/08; B01J41/09; B01J39/00; B01J39/08; B01J39/16; B01J39/17; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
57 words
In a process for the introduction of benzyl groups onto the surface of silicon dioxide by reacting silicon dioxide with benzyltrichlorosilane followed by hydrolysis of the thus-introduced benzylchlorosilyl groups to benzylhydroxysilyl groups, the improvement which comprises conducting the reaction of the silicon dioxide with benzyltrichlorosilane at about 200°-300° C. in the absence of solvent, air and moisture.
Claim 2
Dependent Claim
57 words
In a process for the introduction of benzyl groups onto the surface of silicon dioxide by reacting silicon dioxide with benzyltrichlorosilane followed by hydrolysis of the thus-introduced benzylchlorosilyl groups to benzylhydroxysilyl groups, the improvement which comprises conducting the reaction of the silicon dioxide with benzyltrichlorosilane at about 200°-300° C. in the absence of solvent, air and moisture.
Claim 3
Dependent Claim
15 words
A process according to claim 1, wherein the reaction with benzyltrichlorosilane is conducted in nitrogen.
Claim 4
Dependent Claim
33 words
A process according to claim 1, wherein the silicon dioxide is annealed after reaction with the benzyltrichlorosilane and prior to the hydrolysis, under reduced pressure at a temperature of up to 400° C.
Claim 5
Dependent Claim
31 words
A process according to claim 1, wherein the starting silicon dioxide, prior to the reaction with the benzyltrichlorosilane, is annealed under reduced pressure at a temperature up to about 500° C.
Claim 6
Dependent Claim
70 words
A process according to claim 1, wherein the reaction with benzyltrichlorosilane is conducted for about 24-100 hours; wherein the silicon dioxide is annealed after reaction with the benzyltrichlorosilane and prior to the hydrolysis, under reduced pressure at a temperature of up to 400° C.; and wherein the starting silicon dioxide, prior to the reaction with the benzyltrichlorosilane, is annealed under reduced pressure at a temperature up to about 500° C.
Claim 7
Dependent Claim
12 words
A process according to claim 1, wherein the silicon dioxide is porous.
Claim 8
Dependent Claim
19 words
A process according to claim 6, wherein the silicon dioxide has an average pore diameter greater than 30 A.
Claim 9
Dependent Claim
21 words
A process according to claim 5 wherein the silicon dioxide is porous with an average pore diameter greater than 30 A.
Claim 10
Dependent Claim
19 words
Silicon dioxide having on the surface thereof benzylhydroxysilyl groups at a concentration of 3 to 4.5 μmol./m 2 .
Claim 11
Dependent Claim
19 words
Silicon dioxide having on the surface thereof benzylhydroxysilyl groups at a concentration of 3 to 4.5 μmol./m 2 .
Claim 12
Dependent Claim
8 words
A porous silicon dioxide according to claim 9.
Claim 13
Dependent Claim
16 words
A porous silicon dioxide according to claim 10, wherein the pores are greater than 30 A.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-02 | 1979-08-04 | 1980-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-02 | 1983-08-04 | 1984-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-02 | 1987-08-04 | 1988-02-03 | $7700.00 | Window Closed / Lapsed |