US4502891A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry powder compositions for preparing paint strippers
Assignee: STWB Inc
•
Filing: 1983-10-06
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Granted: 1985-03-05
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Expires: 2003-10-06
Abstract
Abstract Alkaline paint stripper compositions contain either a fibrous material or a combination of a xanthan gum and hectorite clay so as to provide a pellable skin over a painted surface.
Inventors
- 👤 Peter Brocklehurst
- 👤 Angus S. Ferguson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:50
CPC Classifications
B; B08; B08B; B08B7/00; B08B7/0014; C; C09; C09D; C09D9/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
161 words
A composition in dry powder form which can be mixed with water to form a spreadable aqueous paint stripper, which comprises calcium hydroxide and an alkali metal salt, the anion of the alkali metal salt being one which forms a water-insoluble salt with calcium, to thereby provide alkali in an amount such that the aqueous stripper is capable of stripping paint, together with one or more skin forming promoter components comprising either a natural or synthetic water-soluble polymer as a gelling agent in combination with a filler, or a fibrous material in the form of relatively short individual fibers whereby, when the aqueous stripper is applied as a layer over a painted surface to be stripped, it forms over the surface a peelable skin, the skin having a tear strength sufficient for it to be separated and removed from the underlying surface and an adhesive strength sufficient to separate and remove the underlying surface paint softened by contact with the composition.
Claim 2
Dependent Claim
161 words
A composition in dry powder form which can be mixed with water to form a spreadable aqueous paint stripper, which comprises calcium hydroxide and an alkali metal salt, the anion of the alkali metal salt being one which forms a water-insoluble salt with calcium, to thereby provide alkali in an amount such that the aqueous stripper is capable of stripping paint, together with one or more skin forming promoter components comprising either a natural or synthetic water-soluble polymer as a gelling agent in combination with a filler, or a fibrous material in the form of relatively short individual fibers whereby, when the aqueous stripper is applied as a layer over a painted surface to be stripped, it forms over the surface a peelable skin, the skin having a tear strength sufficient for it to be separated and removed from the underlying surface and an adhesive strength sufficient to separate and remove the underlying surface paint softened by contact with the composition.
Claim 3
Dependent Claim
16 words
A composition according to claim 1 wherein the skin forming promoter component comprises a fibrous material.
Claim 4
Dependent Claim
21 words
A composition according to claim 1 wherein the skin forming promoter component comprises a combination of xanthan gum and hectorite clay.
Claim 5
Dependent Claim
14 words
A composition according to claim 2 wherein the alkali metal salt is sodium carbonate.
Claim 6
Dependent Claim
14 words
A composition according to claim 3 wherein the alkali metal salt is sodium carbonate.
Claim 7
Dependent Claim
29 words
A composition according to claim 4 wherein the calcium hydroxide and the sodium carbonate together provide from 3% to 12% by weight of sodium hydroxide in the aqueous stripper.
Claim 8
Dependent Claim
29 words
A composition according to claim 5 wherein the calcium hydroxide and the sodium carbonate together provide from 3% to 12% by weight of sodium hydroxide in the aqueous stripper.
Claim 9
Dependent Claim
10 words
A composition according to claim 5 when mixed with water.
Claim 10
Dependent Claim
10 words
A composition according to claim 7 when mixed with water.
Claim 11
Dependent Claim
65 words
A method of stripping a paint layer from an underlying surface which comprises applying to the paint layer an effective amount of a composition as claimed in claim 1, allowing the composition to form a peelable skin in conjunction with paint softened by the action of the composition, lifting the formed skin and peeling it away from the underlying surface to strip the paint therefrom.
Claim 12
Dependent Claim
65 words
A method of stripping a paint layer from an underlying surface, which comprises applying to the paint layer an effective amount of a composition as claimed in claim 8, allowing the composition to form a peelable skin in conjunction with paint softened by the action of the composition, lifting the formed skin and peeling it away from the underlying surface to strip the paint therefrom.
Claim 13
Dependent Claim
65 words
A method of stripping a paint layer from an underlying surface, which comprises applying to the paint layer an effective amount of a composition as claimed in claim 9, allowing the composition to form a peelable skin in conjunction with paint softened by the action of the composition, lifting the formed skin and peeling it away from the underlying surface to strip the paint therefrom.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-03-04 | 1988-09-03 | 1989-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-04 | 1992-09-03 | 1993-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-04 | 1996-09-03 | 1997-03-05 | $7700.00 | Window Closed / Lapsed |