US5158758A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of silica having high specific surface area
Assignee: International Minerals and Chemical Corp
•
Filing: 1989-04-24
•
Granted: 1992-10-27
•
Expires: 2009-04-24
Abstract
Abstract A method for production of high specific surface area silica gel by hydrolysis of silicon tetrahalide, wherein a solution of silicon tetrahalide in a non-reactive solvent such as alcohol is mixed with water to produce silica gel having a high surface area and narrow pore diameter distribution especially suited for use as normal phase packing material in high performance chromatography columns. The water contains fluoride ions if the halide is chloride. Reverse phase packing material can be prepared by reacting the normal phase silica gel with organochlorosilanes to prepare bonded reverse phase material for use in high performance liquid chromotagraphy systems.
Inventors
- 👤 Paul C. Chieng
- 👤 Deborah J. Brame
- 👤 Alexander H. T. Chu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:10
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/281; B01J20/286; B01J20/287; B01J20/02; B01J20/10; B01J20/103; B01J20/282; B01J20/283; C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/152
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
96 words
A method for production of a porous, high specific surface area silica gel having a narrow pore diameter distribution comprising: (a) mixing a solution of silicon tetrafluoride and a water-soluble, non-aqueous solvent with at least a stoichiometric quantity of water to form a reactant mixture and to hydrolyze the silicon tetrafluoride to silica; (b) permitting the silica to gel; (c) separately recovering the silica gel from the remainder of the reactant mixture; and (d) washing said silica gel with a washing medium comprising water until the pH of the gel is at least above about 3.
Claim 2
Independent Claim
96 words
A method for production of a porous, high specific surface area silica gel having a narrow pore diameter distribution comprising: (a) mixing a solution of silicon tetrafluoride and a water-soluble, non-aqueous solvent with at least a stoichiometric quantity of water to form a reactant mixture and to hydrolyze the silicon tetrafluoride to silica; (b) permitting the silica to gel; (c) separately recovering the silica gel from the remainder of the reactant mixture; and (d) washing said silica gel with a washing medium comprising water until the pH of the gel is at least above about 3.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the concentration of the silicon tetrafluoride solution is between about 5 and 40 wt percent.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein the solvent is a C 1 -C 5 aliphatic alcohol.
Claim 5
Dependent Claim
16 words
The method of claim 3 wherein the alcohol is a C 1 -C 3 aliphatic alcohol.
Claim 6
Dependent Claim
19 words
The method of claim 1 wherein the mass ratio of water to silicon tetrafluoride is at least about 2:1.
Claim 7
Dependent Claim
20 words
The method of claim 5 wherein the mass ratio of water to silicon tetrafluoride is between about 4:1 and 10:1.
Claim 8
Dependent Claim
35 words
The method of claim 1 further comprising adding to the water of step (a) a quantity of ammonia sufficient to produce in the water an ammonium hydroxide concentration of less than about 1.0 wt percent.
Claim 9
Dependent Claim
20 words
The method of claim 1 wherein the washing medium is water having up to about 0.010 wt percent ammonium hydroxide.
Claim 10
Independent Claim
119 words
A method for production of a porous, high specific surface area silica gel having a narrow pore diameter distribution comprising: (a) mixing a solution of silicon tetrafluoride and a solvent selected from the group consisting of C 1 -C 3 aliphatic alcohols with a quantity of water sufficient to form a reactant mixture having a mass ratio of water to silicon tetrafluoride of between about 4:1 and 10:1 and to hydrolyze the silicon tetrafluoride to silica; (b) permitting the silica to gel; (c) separately recovering the silica gel from the remainder of the reactant mixture; and (d) washing said silica gel in a washing medium comprising water until the pH of the gel is at least above about 3.
Claim 11
Independent Claim
119 words
A method for production of a porous, high specific surface area silica gel having a narrow pore diameter distribution comprising: (a) mixing a solution of silicon tetrafluoride and a solvent selected from the group consisting of C 1 -C 3 aliphatic alcohols with a quantity of water sufficient to form a reactant mixture having a mass ratio of water to silicon tetrafluoride of between about 4:1 and 10:1 and to hydrolyze the silicon tetrafluoride to silica; (b) permitting the silica to gel; (c) separately recovering the silica gel from the remainder of the reactant mixture; and (d) washing said silica gel in a washing medium comprising water until the pH of the gel is at least above about 3.
Claim 12
Independent Claim
130 words
A method for producing silica gel suitable for use in high pressure liquid chromatography comprising: (a) mixing a solution of silicon tetrafluoride and a solvent selected from the group consisting of C 1 -C 3 aliphatic alcohols with a quantity of water sufficient to form a reactant mixture having a mass ratio of water to silicon tetrafluoride of between about 4:1 and 10:1 and to hydrolyze the silicon tetrafluoride to silica; (b) permitting the silica to gel; (c) separately recovering the silica gel from the remainder of the reactant mixture; (d) washing said silica gel in a washing medium comprising water until the pH of the gel is at least above about 3; and (e) drying said washed gel to obtain dry gel having essentially one form of silanol moiety.
Claim 13
Independent Claim
130 words
A method for producing silica gel suitable for use in high pressure liquid chromatography comprising: (a) mixing a solution of silicon tetrafluoride and a solvent selected from the group consisting of C 1 -C 3 aliphatic alcohols with a quantity of water sufficient to form a reactant mixture having a mass ratio of water to silicon tetrafluoride of between about 4:1 and 10:1 and to hydrolyze the silicon tetrafluoride to silica; (b) permitting the silica to gel; (c) separately recovering the silica gel from the remainder of the reactant mixture; (d) washing said silica gel in a washing medium comprising water until the pH of the gel is at least above about 3; and (e) drying said washed gel to obtain dry gel having essentially one form of silanol moiety.
Claim 14
Independent Claim
106 words
A method for production of a porous, high specific surface area silica gel having a narrow pore diameter distribution comprising: (a) mixing a solution of silicon tetrachloride and a water-soluble, non-aqueous solvent with at least a stoichiometric quantity of water containing fluoride ion to form a reactant mixture and to hydrolyze the silicon tetrachloride to silica; (b) permitting the silica to gel; (c) aging the gel for about 4 hours; (d) separately recovering the silica gel from the remainder of the reactant mixture; and (e) washing said silica gel with a washing medium comprising until the pH of the gel is at least above about 3.
Claim 15
Independent Claim
106 words
A method for production of a porous, high specific surface area silica gel having a narrow pore diameter distribution comprising: (a) mixing a solution of silicon tetrachloride and a water-soluble, non-aqueous solvent with at least a stoichiometric quantity of water containing fluoride ion to form a reactant mixture and to hydrolyze the silicon tetrachloride to silica; (b) permitting the silica to gel; (c) aging the gel for about 4 hours; (d) separately recovering the silica gel from the remainder of the reactant mixture; and (e) washing said silica gel with a washing medium comprising until the pH of the gel is at least above about 3.
Claim 16
Dependent Claim
21 words
The method of claim 11 wherein the concentration of the silicon tetrachloride solution is between about 5 and 40 wt percent.
Claim 17
Dependent Claim
15 words
The method of claim 11 wherein the solvent is C 1 -C 5 aliphatic alcohol.
Claim 18
Dependent Claim
16 words
The method of claim 13 wherein the alcohol is a C 1 -C 3 aliphatic alcohol.
Claim 19
Dependent Claim
19 words
The method of claim 11 wherein the molar ratio of water to silicon tetrachloride is at least about 5:1.
Claim 20
Dependent Claim
20 words
The method of claim 15 wherein the molar ratio of water to silicon tetrachloride is between about 5:1 and 30:1.
Claim 21
Dependent Claim
21 words
The method of claim 11 wherein the fluoride ion concentration of step (a) is between about 1 and 6 wt percent.
Claim 22
Dependent Claim
20 words
The method of claim 11 wherein the washing medium is water having up to about 0.010 wt percent ammonium hydroxide.
Claim 23
Independent Claim
149 words
A method for production of a porous, high specific surface area silica gel having a narrow pore diameter distribution comprising: (a) mixing a solution of silicon tetrachloride and a solvent selected from the group consisting of C 1 -C 3 aliphatic alcohols with a quantity of water containing up to 6 wt percent fluoride ion, said quantity of fluoride ion-containing water sufficient to form a reactant mixture having molar ratio of water to silicon tetrachloride of between about 5:1 and 30:1 and to hydrolyze the silicon tetrachloride to silica; (b) permitting the silica to gel; (c) aging the gel for about 4 hours at a temperature between about 20° and 80° C.; (d) separately recovering the silica gel from the remainder of the reactant mixture; and (e) washing said silica gel with a washing medium comprising water until the pH of the gel is at least above about 3.
Claim 24
Independent Claim
149 words
A method for production of a porous, high specific surface area silica gel having a narrow pore diameter distribution comprising: (a) mixing a solution of silicon tetrachloride and a solvent selected from the group consisting of C 1 -C 3 aliphatic alcohols with a quantity of water containing up to 6 wt percent fluoride ion, said quantity of fluoride ion-containing water sufficient to form a reactant mixture having molar ratio of water to silicon tetrachloride of between about 5:1 and 30:1 and to hydrolyze the silicon tetrachloride to silica; (b) permitting the silica to gel; (c) aging the gel for about 4 hours at a temperature between about 20° and 80° C.; (d) separately recovering the silica gel from the remainder of the reactant mixture; and (e) washing said silica gel with a washing medium comprising water until the pH of the gel is at least above about 3.
Claim 25
Independent Claim
118 words
A method for producing silica gel suitable for use in high pressure liquid chromatography comprising: (a) mixing a solution of silicon tetrachloride and a water-soluble, non-aqueous solvent with at least a stoichiometric quantity of water containing fluoride ion to form a reactant mixture and to hydrolyze the silicon tetrachloride to silica; (b) permitting the silica to gel; (c) aging the gel for about 4 hours; (d) separately recovering the silica gel from the remainder of the reactant mixture; (e) washing said silica gel with a washing medium comprising water until the pH of the gel is at least above about 3; and (f) drying said washed gel to obtain dry gel having essentially one form of silanol moiety.
Claim 26
Independent Claim
118 words
A method for producing silica gel suitable for use in high pressure liquid chromatography comprising: (a) mixing a solution of silicon tetrachloride and a water-soluble, non-aqueous solvent with at least a stoichiometric quantity of water containing fluoride ion to form a reactant mixture and to hydrolyze the silicon tetrachloride to silica; (b) permitting the silica to gel; (c) aging the gel for about 4 hours; (d) separately recovering the silica gel from the remainder of the reactant mixture; (e) washing said silica gel with a washing medium comprising water until the pH of the gel is at least above about 3; and (f) drying said washed gel to obtain dry gel having essentially one form of silanol moiety.
References Cited (Backward Citations)
US1451399A
Cited
US1539342A
Cited
US2269059A
Cited
US2386337A
Cited
US2715060A
Cited
US2990249A
Cited
US3236594A
Cited
US3494875A
Cited
JPS5053298A
Cited
JPS5148797A
Cited
US4301034A
Cited
US4339559A
Cited
US4504595A
Cited
US4840653A
Cited
US4683128A
Cited
US4826521A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-10-27 | 1996-04-27 | 1996-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-27 | 2000-04-27 | 2000-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-27 | 2004-04-27 | 2004-10-27 | $7700.00 | Window Closed / Lapsed |