Patent US4082683A successfully refreshed from Google Patents.
US4082683A
Expired / Lapsed
US
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Cleaning of hard surfaces
Assignee: Lever Brothers Co
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Filing: 1976-09-10
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Granted: 1978-04-04
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Expires: 1996-09-10
Abstract
Abstract An improved dithionite composition suitable for preparing stock solutions comprising a dithionite, e.g., sodium dithionite, and at least 5% by weight of a water-soluble sulphite, e.g., sodium sulphite. The composition may further contain a metal-complexing agent, an activator for the dithionite, a surface-active agent and a thickening agent. The composition is applicable for the removal of metal dust soiling and metal oxide stains, particularly rust stains, from surfaces.
Inventors
- 👤 Wilhelmus Gerardus Galesloot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:36
CPC Classifications
C; C11; C11D; C11D3/00; C11D3/0005; C11D3/0042; C23; C23G; C23G1/00; C23G1/24
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
239 words
A dithionite composition which upon admixture with water forms a solution of pH 5 to 9 consisting essentially of: a. 20-60% by weight of a dithionite selected from the group consisting of alkali metal dithionites and zinc dithionites; b. 10-50% by weight of a water soluble sulfite selected from the group consisting of alkali metal sulfites and ammonium sulfite; c. 5-30% by weight of a metal-complexing agent selected from the group consisting of nitrilotriacetic acid; the alkali metal salts of nitrilotriacetic acid, ethylene diamine tetraacetic acid; the alkali metal salts of ethylene diamine tetraacetic acid; citric acid; the alkali metal salts of citric acid; gluconic acid; the alkali metal salts of gluconic acid; d. 0.3-5% by weight of an activator for said dithionite, wherein said activator is selected from the group consisting of OH - , Cl - , Br - or NO - 2 substituted benzoquinone; OH - , Cl - , Br - or NO - 2 substituted naphthoquinone, and SO 3 H - or OH - substituted anthraquinone; e. 1-15% by weight of a thickening agent in an amount sufficient to result in said composition having a viscosity of about 20 to about 100 centipoises when admixed with water, said thickening agent being selected from the group consisting of derivatives of polysaccharides and hydroxyethylcellulose; and f. optionally 0-10% by weight of an anionic or nonionic organic surface active agent, and 0-40% by weight of sodium sulfate.
Claim 2
Dependent Claim
239 words
A dithionite composition which upon admixture with water forms a solution of pH 5 to 9 consisting essentially of: a. 20-60% by weight of a dithionite selected from the group consisting of alkali metal dithionites and zinc dithionites; b. 10-50% by weight of a water soluble sulfite selected from the group consisting of alkali metal sulfites and ammonium sulfite; c. 5-30% by weight of a metal-complexing agent selected from the group consisting of nitrilotriacetic acid; the alkali metal salts of nitrilotriacetic acid, ethylene diamine tetraacetic acid; the alkali metal salts of ethylene diamine tetraacetic acid; citric acid; the alkali metal salts of citric acid; gluconic acid; the alkali metal salts of gluconic acid; d. 0.3-5% by weight of an activator for said dithionite, wherein said activator is selected from the group consisting of OH - , Cl - , Br - or NO - 2 substituted benzoquinone; OH - , Cl - , Br - or NO - 2 substituted naphthoquinone, and SO 3 H - or OH - substituted anthraquinone; e. 1-15% by weight of a thickening agent in an amount sufficient to result in said composition having a viscosity of about 20 to about 100 centipoises when admixed with water, said thickening agent being selected from the group consisting of derivatives of polysaccharides and hydroxyethylcellulose; and f. optionally 0-10% by weight of an anionic or nonionic organic surface active agent, and 0-40% by weight of sodium sulfate.
Claim 3
Dependent Claim
22 words
A dithionite composition as claimed in claim 1, in which the dithionite is sodium dithionite and the water-soluble sulphite is sodium sulphite.
Claim 4
Dependent Claim
31 words
A dithionite composition as claimed in claim 1, the solution of which has a pH within the range of 6 to 8 and a viscosity of 30 cps to 80 cps.
Claim 5
Dependent Claim
17 words
A dithionite composition as claimed in claim 1, which incorporates an SO 3 H-- or OH-substituted anthraquinone.
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) | 1981-04-03 | 1981-10-03 | 1982-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-03 | 1985-10-03 | 1986-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-03 | 1989-10-03 | 1990-04-04 | $7700.00 | Window Closed / Lapsed |