US3884835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crystalline silica compositions
Assignee: WR Grace and Co
•
Filing: 1973-02-09
•
Granted: 1975-05-20
•
Expires: 1993-02-09
Abstract
Abstract New crystalline silicas are synthesized from a sodium silicate or other silica source solution having a Na2O/SiO2 ratio of about 0.3 up to 7. These new silicas are formed at elevated temperatures wherein the precursor solution is at a pH of at least about 10. The precursor solution is aged for from 15-75 days, preferably with a promotor which is a metal salt of group 3A, 5B or 6B. Depending on the reaction period the silica is either of a very fine particle (<.2 Mu ) or of a platelet form.
Inventors
- 👤 David E W Vaughan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:24
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/16; B01J23/18; B01J23/02; B01J23/04; B01J23/24; B01J23/28; B01J29/00; B01J29/03; B01J29/035; C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/18; C09; C09C; C09C1/00; C09C1/0015; C09C1/0018; C01P; C01P2002/00; C01P2002/70; C01P2002/72; C01P2004/00; C01P2004/20; C01P2004/60; C01P2004/62; C01P2006/00; C01P2006/12; C01P2006/19
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
9 words
The crystalline silica composition having the x-ray diffraction pattern
Claim 2
Dependent Claim
9 words
The crystalline silica composition having the x-ray diffraction pattern
Claim 3
Independent Claim
52 words
THE METHOD OF PRODUCING A CRYSTALLINE SILICA COMPRISING FORMING AN AQUEOUS ALKALI SILICA MIXTURE WHEREIN THE RATIO OF ALKALI OXIDE TO SILICA IS IN THE RANGE OF 0.3 UP TO 7, HEATING SAID MIXTURE AT ABOUT 100*C TO 250*C FOR FROM ABOUT 10 UP TO 40 DAYS, AND RECOVERING A CRYSTALLINE SILICA.
Claim 4
Independent Claim
52 words
THE METHOD OF PRODUCING A CRYSTALLINE SILICA COMPRISING FORMING AN AQUEOUS ALKALI SILICA MIXTURE WHEREIN THE RATIO OF ALKALI OXIDE TO SILICA IS IN THE RANGE OF 0.3 UP TO 7, HEATING SAID MIXTURE AT ABOUT 100*C TO 250*C FOR FROM ABOUT 10 UP TO 40 DAYS, AND RECOVERING A CRYSTALLINE SILICA.
Claim 5
Dependent Claim
32 words
The method as in claim 2 wherein the source of silica in said mixture is sodium silicate and said alkali is selected from the group consisting of sodium, potassium and mixtures thereof.
Claim 6
Dependent Claim
32 words
The method as in claim 2 wherein the source of silica in said mixture is colloidal silica and said alkali is selected from the group consisting of sodium, potassium and mixtures thereof.
Claim 7
Dependent Claim
35 words
THE METHOD AS IN CLAIM 2 WHEREIN SAID MIXTURE CONTAINS A PROMOTIONAL METAL OXIDE SELECTED FROM THE GROUP CONSISTING OF GROUP 3A METAL OXIDES, GROUP 5B METAL OXIDES, GROUP 6B METAL OXIDES AND MIXTURES THEREOF.
Claim 8
Dependent Claim
26 words
The method as in claim 5 wherein said metal oxide is selected from the group consisting of tungsten oxides, vanadium oxides, molybdenum oxides and boron oxides.
Claim 9
Dependent Claim
20 words
The method as in claim 5 wherein the ratio of promotional metal oxide to silica is up to about 1.
Claim 10
Dependent Claim
26 words
The method as in claim 2 wherein said crystalline silica has a nitrogen surface area of greater than 40 m2/g and an x-ray diffraction pattern of
Claim 11
Dependent Claim
10 words
The crystalline silica composition having the x-ray diffraction pattern of
Claim 12
Dependent Claim
10 words
The crystalline silica composition having the x-ray diffraction pattern of
Claim 13
Independent Claim
51 words
The method of producing a crystalline silica comprising forming an aqueous alkali silica mixture wherein the ratio of alkali oxide to silica is in the range of 0.3 up to 7, heating said mixture at about 100*C to 250*C for from more than about 40 days, and recovering a crystalline silica.
Claim 14
Independent Claim
51 words
The method of producing a crystalline silica comprising forming an aqueous alkali silica mixture wherein the ratio of alkali oxide to silica is in the range of 0.3 up to 7, heating said mixture at about 100*C to 250*C for from more than about 40 days, and recovering a crystalline silica.
Claim 15
Dependent Claim
32 words
The method as in claim 10 wherein the source of silica in said mixture is sodium silicate and said alkali is selected from the group consisting of sodium, potassium and mixtures thereof.
Claim 16
Dependent Claim
32 words
The method as in claim 10 wherein the source of silica in said mixture is colloidal silica and said alkali is selected from the group consisting of sodium, potassium and mixtures thereof.
Claim 17
Dependent Claim
35 words
The method as in claim 10 wherein said mixture contains a promotional metal oxide selected from the group consisting of Group 3A metal oxides, Group 5B metal oxides, Group 6B metal oxides and mixtures thereof.
Claim 18
Dependent Claim
26 words
The method as in claim 13 wherein said metal oxide is selected from the group consisting of tungsten oxides, vanadium oxides, molybdenum oxides and boron oxides.
Claim 19
Dependent Claim
20 words
The method as in claim 13 wherein the ratio of promotional metal oxide to silica is up to about 1.
Claim 20
Dependent Claim
26 words
The method as in claim 10 wherein said crystalline silica has a nitrogen surface area of greater than 40 m2/g and an x-ray diffraction pattern of
Claim 21
Dependent Claim
24 words
The method as in claim 16 wherein said crystalline silica is platelet in form having length to thickness ratios of about 5:1 to 100:1.
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) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |