US4518516A
Expired / Lapsed
US
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Sodium metasilicate particulates and detergent compositions comprised thereof
Assignee: Rhone Poulenc Chimie de Base SA
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Filing: 1983-07-11
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Granted: 1985-05-21
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Expires: 2003-07-11
Abstract
Abstract Novel granular particulates of sodium metasilicate, well adapted for improved detergency applications, are comprised of a central core of essentially anhydrous sodium metasilicate and a core-enveloping sheath of sodium metasilicate pentahydrate therefor, the amount of water which comprises said sodium metasilicate pentahydrate comprising at least 10% by weight, and advantageously from 10 to 20 or 25% by weight, of the total weight of said particulates.
Inventors
- 👤 Gerard Godard
- 👤 Daniel Joubert
- 👤 Philippe Gagnaire
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:22
CPC Classifications
C; C11; C11D; C11D7/00; C11D7/02; C11D7/04; C11D7/10; C11D7/14; C01; C01B; C01B33/00; C01B33/20; C01B33/32; C01B33/325; C11D3/00; C11D3/02; C11D3/04; C11D3/08
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
63 words
Granular particulates of sodium metasilicate, said particulates comprising a central core of essentially anhydrous sodium metasilicate and a core-enveloping sheath of sodium metasilicate pentahydrate therefor, the granular particulates comprising from 73 to 88% by weight of sodium metasilicate and from 10 to about 25% by weight of water, and having an apparent volume ranging from about 1.05 to about 1.20 g/cm 3 .
Claim 2
Dependent Claim
63 words
Granular particulates of sodium metasilicate, said particulates comprising a central core of essentially anhydrous sodium metasilicate and a core-enveloping sheath of sodium metasilicate pentahydrate therefor, the granular particulates comprising from 73 to 88% by weight of sodium metasilicate and from 10 to about 25% by weight of water, and having an apparent volume ranging from about 1.05 to about 1.20 g/cm 3 .
Claim 3
Dependent Claim
28 words
The granular particulates as defined by claim 1, comprising from 78 to 88% by weight of sodium metasilicate and from 10 to about 20% by weight of water.
Claim 4
Dependent Claim
19 words
The granular particulates as defined by claim 1, comprising from about 12 to about 18% by weight of water.
Claim 5
Dependent Claim
20 words
The granular particulates as defined by claim 1, having an average diameter ranging from about 0.55 to about 0.68 mm.
Claim 6
Dependent Claim
48 words
The granular particulates as defined by claim 4, the percentage by weight thereof having a particle size in excess of 1 mm being no greater than about 15% and the percentage by weight thereof having a particle size less than 0.25 mm being no greater than about 1%.
Claim 7
Dependent Claim
98 words
A process for the preparation of the granular particulates as defined by claim 1, comprising (i) establishing, in a zone of granulation, an agitated bed of particles of essentially anhydrous sodium metasilicate, (ii) intimately contacting said agitated particles with an atomized spray of a liquid formulation of sodium metasilicate, and thence (iii) treating the thus coated granular particulates with a stream of a cooling gas as to convert and hydrate the surface layers thereof to crystalline sodium metasilicate pentahydrate, the water of hydration thereof comprising at least 10% by weight of the total weight of the resulting particulates.
Claim 8
Dependent Claim
21 words
The process as defined by claim 6, said conversion and hydration step (iii) being carried out in a zone of maturation.
Claim 9
Dependent Claim
29 words
The process as defined by claim 7, said conversion and hydration step (iii) being initiated in a first zone of partial crystallization and completed in said zone of maturation.
Claim 10
Dependent Claim
24 words
The process as defined by claim 6, said liquid formulation of sodium metasilicate having a dry solids content of 30 to 58% by weight.
Claim 11
Dependent Claim
24 words
The process as defined by claim 9, said liquid formulation of sodium metasilicate having a dry solids content of 40 to 50% by weight.
Claim 12
Dependent Claim
33 words
The process as defined by claim 9, the ponderal ratio between the dry solids content of the liquid formulation of sodium metasilicate to the starting material sodium metasilicate ranging from 0.042 to 0.28.
Claim 13
Dependent Claim
14 words
The process as defined by claim 11, said ratio ranging from 0.08 to 0.16.
Claim 14
Dependent Claim
23 words
The process as defined by claim 6, said particles of anhydrous sodium metasilicate being maintained as a rolling bed in said granulation zone.
Claim 15
Dependent Claim
23 words
The process as defined by claim 13, the residence time of the particulates in said granulation zone ranging from 5 to 30 minutes.
Claim 16
Dependent Claim
26 words
The process as defined by claim 14, the temperature of the particulates at the outlet of said granulation zone ranging from about ambient to 50° C.
Claim 17
Dependent Claim
24 words
The process as defined by claim 15, said temperature being maintained by sweeping said granulation zone with a cocurrent stream of ambient temperature gas.
Claim 18
Dependent Claim
19 words
The process as defined by claim 8, said particulates being maintained as a falling bed in said maturation zone.
Claim 19
Dependent Claim
23 words
The process as defined by claim 17, the residence time of the particulates in said maturation zone ranging from 30 to 60 minutes.
Claim 20
Dependent Claim
25 words
The process as defined by claim 18, the temperature of the particulates at the outlet of said maturation zone being less than about 35° C.
Claim 21
Dependent Claim
24 words
The process as defined by claim 19, said temperature being maintained by sweeping said maturation zone with a countercurrent stream of ambient temperature gas.
Claim 22
Dependent Claim
26 words
The process as defined by claim 19, further comprising sifting the product particulates to desired granulometry and recycling any fines and dust to said granulation zone.
Claim 23
Dependent Claim
13 words
A detergent composition comprised of the granular particulates as defined by claim 1.
Claim 24
Dependent Claim
19 words
The detergent composition as defined by claim 22, comprising from 20 to 70% by weight of said granular particulates.
Claim 25
Dependent Claim
76 words
The detergent composition as defined by claim 23, further comprising from 10 to 70% by weight of an alkali metal phosphate or polyphosphate, from 1 to 30% by weight sodium carbonate, from 0.2 to 3% by weight of a non-ionic surfactant, from 0.2 to 5% by weight of a chlorine-releasing compound, from 0.2 to 5% by weight of at least one detergent additive, and from 0 to 50% by weight of a natural or synthetic aluminosilicate.
Claim 26
Dependent Claim
29 words
In a method for the washing of household kitchenware employing a detergent, the improvement which comprises employing as said detergent therefor, the detergent composition as defined by claim 24.
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) | 1988-05-20 | 1988-11-19 | 1989-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-20 | 1992-11-19 | 1993-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-20 | 1996-11-19 | 1997-05-21 | $7700.00 | Window Closed / Lapsed |