US4289643A
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Stabilization of anhydrous sodium metasilicate
Assignee: Rhone Poulenc Industries SA
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Filing: 1979-08-30
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Granted: 1981-09-15
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Expires: 1999-08-30
Abstract
Abstract Anhydrous sodium metasilicate is stabilized against attrition or "dusting" in detergent and other use, by formulating same with such amount of an additive, e.g., a hydrate, that will transfer water content to the anhydrous metasilicate, at a temperature less than the fusion temperature of sodium metasilicate pentahydrate and as will convert from about 1% to 20% by weight of said anhydrous metasilicate into its pentahydrate form.
Inventors
- 👤 Daniel Joubert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:10
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/32; C01B33/325; C11; C11D; C11D3/00; C11D3/02; C11D3/04; C11D3/08
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
138 words
A composition of matter comprising (i) anhydrous sodium metasilicate, and (ii) a minor amount of an inorganic molecular water donor including either bound water of hydration or free water of sorption which will evolve its water content to the metasilicate (i), at a temperature less than that required for the fusion of sodium metasilicate pentahydrate (72.2° C.), and as will convert from about 1% to about 20% by weight of said anhydrous metasilicate into its said pentahydrate, said water donor (ii) being selected from the group consisting of Na 2 B 4 O 7 .10H 2 O, Na 2 CO 3 . 7H 2 O, Na 2 HPO 4 .7H 2 O, Na 2 HPO 4 .12H 2 O, (NaPO 3 ) 3 .6H 2 O, Na 2 SO 4 .10H 2 O, a caustic compound and silica.
Claim 2
Dependent Claim
138 words
A composition of matter comprising (i) anhydrous sodium metasilicate, and (ii) a minor amount of an inorganic molecular water donor including either bound water of hydration or free water of sorption which will evolve its water content to the metasilicate (i), at a temperature less than that required for the fusion of sodium metasilicate pentahydrate (72.2° C.), and as will convert from about 1% to about 20% by weight of said anhydrous metasilicate into its said pentahydrate, said water donor (ii) being selected from the group consisting of Na 2 B 4 O 7 .10H 2 O, Na 2 CO 3 . 7H 2 O, Na 2 HPO 4 .7H 2 O, Na 2 HPO 4 .12H 2 O, (NaPO 3 ) 3 .6H 2 O, Na 2 SO 4 .10H 2 O, a caustic compound and silica.
Claim 3
Dependent Claim
37 words
The composition of matter as defined by claim 1, wherein the water donor (ii) is present in such amount as will convert from 2% to about 10% by weight of said anhydrous metasilicate into its said pentahydrate.
Claim 4
Dependent Claim
64 words
The composition of matter as defined by claim 1, the water donor being selected from the group consisting of Na 2 B 4 O 7 .10H 2 O, Na 2 CO 3 .7H 2 O, Na 2 HPO 4 .7H 2 O, Na 2 HPO 4 .12H 2 O, (NaPO 3 ) 3 .6H 2 O and Na 2 SO 4 .10H 2 O.
Claim 5
Dependent Claim
33 words
The composition of matter as defined by claim 1, wherein the water donor (ii) is a powder having water sorbed therein in an amount in excess of that required for equilibrium of hydration.
Claim 6
Dependent Claim
19 words
The composition of matter as defined by claim 1, wherein the water donor (ii) is a soluble caustic compound.
Claim 7
Dependent Claim
30 words
The composition of matter as defined by claim 1, wherein the water donor (ii) is selected from the group consisting of silica, an insoluble derivative of silica, and precipitated silica.
Claim 8
Dependent Claim
29 words
The composition of matter as defined by claim 1, the water donor (ii) being present in an amount of from 0.1 to about 5% of the anhydrous metasilicate (i).
Claim 9
Dependent Claim
14 words
The composition of matter as defined by claim 1, in finely divided, particulate form.
Claim 10
Dependent Claim
25 words
The composition of matter as defined by claim 1, the about 1% to about 20% of sodium metasilicate pentahydrate being converted from anhydrous dust fines.
Claim 11
Dependent Claim
26 words
In a detergent formulation including an anti-redeposition agent, the improvement which comprises, as the anti-redeposition agent therefor, the composition of matter as defined by claim 1.
Claim 12
Dependent Claim
45 words
The detergent formulation as defined by claim 10, consisting essentially of 20 to 60% of the metasilicate (i), 0.1 to 5% of the water donor (ii), 30 to 70% sodium tripolyphosphate, 10 to 30% of sodium carbonate and 0.1 to 3% of a chlorinating agent.
Claim 13
Dependent Claim
12 words
The detergent formulation as defined by claim 10 further comprising a surfactant.
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) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |