Patent US3984526A successfully refreshed from Google Patents.
US3984526A
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Method of manufacturing aqueous solutions of alkali polysilicates
Assignee: Dynamit Nobel AG
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Filing: 1974-08-12
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Granted: 1976-10-05
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Expires: 1994-08-12
Abstract
Abstract A process for the preparation of an aqueous alkali metal polysilicate solution having an SiO 2 : alkali metal oxide mole ratio of 2.5 - 5.5 : 1 and a silica content of 16 - 23% by weight which comprises contacting a tetraalkoxysilane of the formula Si(OR) 4 wherein each R is independently a straight or branched-chain alkyl group of 1 to 3 carbon atoms with an aqueous alkali metal hydroxide solution at a temperature between room temperature and the boiling point of the reaction mixture and at a temperature up to 100°C. distilling over alcohol formed by the reaction of the silane with the alkali metal hydroxide.
Inventors
- 👤 Rainer Haase
- 👤 Volker Hunger
- 👤 Arnold Lenz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:46
CPC Classifications
C; C09; C09D; C09D1/00; C09D1/02; C01; C01B; C01B33/00; C01B33/20; C01B33/32; C08; C08G; C08G77/00; C08G77/02; C08K; C08K3/00; C08K3/02; C08K3/08; C09D183/00; C09D183/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
178 words
A process for the preparation of a stable aqueous alkali metal polysilicate solution having an SiO 2 :alkali metal oxide mole ratio of 2.5-5.5:1 and a silica content of 16-23% by weight which comprises contacting a tetraalkoxysilane of the formula (Si(OR) 4 wherein each R is independently a straight or branched-chain alkyl group of 1 to 3 carbon atoms with an agent consisting essentially of an aqueous alkali metal hydroxide solution at a temperature between room temperature and the boiling point of the reaction mixture and at a temperature up to 100°C, the ratio of silane to alkali metal hydroxide being such that the reaction product has an SiO 2 :alkali metal oxide mole ratio of 2.5-5.5:1, distilling over substantially all of the alcohol formed by the reaction of the silane with the alkali metal hydroxide and during or immediately following the distillation to obtain an aqueous alkali metal polysilicate solution having a silica content of 16-23% by weight of the alcohol adding water to the residual product from the distillation and cooling the residual product with stirring.
Claim 2
Dependent Claim
178 words
A process for the preparation of a stable aqueous alkali metal polysilicate solution having an SiO 2 :alkali metal oxide mole ratio of 2.5-5.5:1 and a silica content of 16-23% by weight which comprises contacting a tetraalkoxysilane of the formula (Si(OR) 4 wherein each R is independently a straight or branched-chain alkyl group of 1 to 3 carbon atoms with an agent consisting essentially of an aqueous alkali metal hydroxide solution at a temperature between room temperature and the boiling point of the reaction mixture and at a temperature up to 100°C, the ratio of silane to alkali metal hydroxide being such that the reaction product has an SiO 2 :alkali metal oxide mole ratio of 2.5-5.5:1, distilling over substantially all of the alcohol formed by the reaction of the silane with the alkali metal hydroxide and during or immediately following the distillation to obtain an aqueous alkali metal polysilicate solution having a silica content of 16-23% by weight of the alcohol adding water to the residual product from the distillation and cooling the residual product with stirring.
Claim 3
Dependent Claim
14 words
A process according to claim 1 wherein the alkali metal hydroxide is sodium hydroxide.
Claim 4
Dependent Claim
14 words
A process according to claim 1 wherein the alkali metal hydroxide is potassium hydroxide.
Claim 5
Dependent Claim
14 words
A process according to claim 1 wherein said alkali metal hydroxide is lithium hydroxide.
Claim 6
Dependent Claim
11 words
A process according to claim 1 wherein said tetraalkoxysilane is tetramethoxysilane.
Claim 7
Dependent Claim
32 words
A process according to claim 1 wherein an amount of water in said aqueous alkali metal hydroxide solution is present such that a portion thereof is removed during distillation of said alcohol.
Claim 8
Dependent Claim
54 words
A process according to claim 1 wherein the water content of the alkali metal hydroxide solution is no greater than the water content of the final product and there is added to the residual product after distillation an amount of water at least sufficient to compensate for any water distilled over with said alcohol.
Claim 9
Dependent Claim
30 words
A process according to claim 1 wherein the distillation of the alcohol is carried out until the residual alcohol content in the residual product is less than 2% by weight.
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) | 1979-10-05 | 1980-04-05 | 1980-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-05 | 1984-04-05 | 1984-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-05 | 1988-04-05 | 1988-10-05 | $7700.00 | Window Closed / Lapsed |