US4585642A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of crystalline sodium silicates
Assignee: Clariant Produkte Deutschland GmbH
•
Filing: 1985-05-09
•
Granted: 1986-04-29
•
Expires: 2005-05-09
Abstract
Abstract A process for the preparation of crystalline sodium silicates with a molar ratio SiO 2 /Na 2 O of 1.9:1 to 3.5:1 from amorphous sodium silicate is described. To water-containing amorphous sodium silicate with a molar ratio SiO 2 /Na 2 O of 1.7:1 to 3.75:1 and a water content of 5 to 95% by weight is added 0.01 to 30 parts by weight of the crystalline sodium silicate to be prepared (per 100 parts by weight of Na 2 O+SiO 2 in the water-containing amorphous sodium silicate). The reaction mixture is dehydrated by heating. The dehydrated reaction mixture is kept at a temperature of at least 450° C., but below the melting point, until the sodium silicate has crystallized.
Inventors
- 👤 Hans-Peter Rieck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:24
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/36; C01B33/38
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
120 words
A process for the preparation of crystalline sodium silicates with a molar ratio SiO 2 /Na 2 O of 1.9:1 to 3.5:1 from amorphous sodium silicate at elevated temperature, which comprises adding to water-containing amorphous sodium silicate with a molar ratio SiO 2 /Na 2 O of 1.7:1 to 3.75:1, and a water content of 5 to 95% by weight, 0.01 to 30 parts by weight of the crystalline sodium silicate to be prepared (per 100 parts by weight of Na 2 O+SiO 2 in the water-containing amorphous silicate), dehydrating the reaction mixture by heating, and keeping the dehydrated reaction mixture at a temperature of at least 450° C., but below the melting point, until the sodium silicate has crystallized.
Claim 2
Dependent Claim
120 words
A process for the preparation of crystalline sodium silicates with a molar ratio SiO 2 /Na 2 O of 1.9:1 to 3.5:1 from amorphous sodium silicate at elevated temperature, which comprises adding to water-containing amorphous sodium silicate with a molar ratio SiO 2 /Na 2 O of 1.7:1 to 3.75:1, and a water content of 5 to 95% by weight, 0.01 to 30 parts by weight of the crystalline sodium silicate to be prepared (per 100 parts by weight of Na 2 O+SiO 2 in the water-containing amorphous silicate), dehydrating the reaction mixture by heating, and keeping the dehydrated reaction mixture at a temperature of at least 450° C., but below the melting point, until the sodium silicate has crystallized.
Claim 3
Dependent Claim
47 words
The process as claimed in claim 1, wherein 1 to 15 parts by weight of the crystalline sodium silicate to be prepared (per 100 parts by weight of Na 2 O+SiO 2 in the water-containing amorphous sodium silicate) are added to the water-containing amorphous sodium silicate used.
Claim 4
Dependent Claim
21 words
The process as claimed in claim 1, wherein the amorphous sodium silicate used has a water content of 15-26% by weight.
Claim 5
Dependent Claim
20 words
The process as claimed in claim 1, wherein the sodium silicate used has a water content of 50-70% by weight.
Claim 6
Dependent Claim
33 words
The process as claimed in claim 1, wherein both the amorphous water-containing sodium silicate and the added crystalline sodium silicate have a molar ratio SiO 2 /Na 2 O of 1.7:1 to 2.3:1.
Claim 7
Dependent Claim
28 words
The process as claimed in claim 1, wherein the dehydrated reaction mixture is comminuted mechanically and is then kept at a temperature which is at least 450° C.
Claim 8
Dependent Claim
25 words
The process as claimed in claim 1, wherein the added crystalline sodium silicate has a molar ratio SiO 2 /Na 2 O of about 2:1.
Claim 9
Dependent Claim
20 words
The process as claimed in claim 7, wherein the added sodium silicate has X-ray spectra in accordance with Table 2.
Claim 10
Dependent Claim
21 words
The process as claimed in claim 8, wherein the crystallization is carried out in the range from 700° to 800° C.
Claim 11
Dependent Claim
20 words
The process as claimed in claim 9, wherein the dehydrated reaction mixture is heated at 700°-770° C. for 1-80 minutes.
Claim 12
Dependent Claim
20 words
The process as claimed in claim 9, wherein the dehydrated reaction mixture is heated at 770°-800° C. for 1-12 minutes.
References Cited (Backward Citations)
US2795485A
Cited
US3377134A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-28 | 1989-10-28 | 1990-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-28 | 1993-10-28 | 1994-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-28 | 1997-10-28 | 1998-04-29 | $7700.00 | Window Closed / Lapsed |