US4067840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal coating suitable for lead-based paint hazard abatement or the like and formulations therefor
Assignee: Sherwin Williams Co
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Filing: 1976-05-24
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Granted: 1978-01-10
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Expires: 1996-05-24
Abstract
Abstract Protective coatings, such as paints and liquid formulations therefor, containing a masked chromogen which signals contact with a body fluid when the protective coating is masticated or ingested are disclosed. The chromogen is capable of producing a contrasting color when masticated and/or ingested, thereby signaling that the individual who masticated and/or ingested the chromogen may have ingested an undesirable or hazardous substance, e.g., a lead-based paint, that has been covered by the protective coating. The chromogen is substantially indiscernible in the paint and converts by reaction with an activator substance, e.g., by reaction with saliva, gastric juices, or the like, to a colored form which then stains the body fluids and/or the body tissues, and which may also stain the original source of the undesirable substance. The chromogen may be a leuco base or a color base of a dye, or it may be a color indicator substance or a reagent specific to the undesirable or hazardous substance or to a body fluid component. Preferably the chromogen is present in the form of pressure-rupturable microcapsules that release the chromogen when masticated. If desired, an acerbic agent can be also incorporated into the protective coatings of this invention.
Inventors
- 👤 Richard E. Wolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:37
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; C; C09; C09D; C09D7/00; C09D7/40; C09D7/41; C08; C08K; C08K5/00; C08K5/01; C08K5/04; C08K5/15; C08K5/151; C08K5/1545; C08K5/36; C08K5/45; C08K5/46; C08K9/00; C08K9/10
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
59 words
An aqueous latex coating composition comprising an aqueous continuous phase having stably suspended therein coalescable polymeric particles, a pigment, and signal means including a physiologically acceptable chromogen present in an amount sufficient to signal ingestion and in a form not visually discernible in said composition but capable of producing a contrasting color upon contacting an activator substance upon ingestion.
Claim 2
Dependent Claim
59 words
An aqueous latex coating composition comprising an aqueous continuous phase having stably suspended therein coalescable polymeric particles, a pigment, and signal means including a physiologically acceptable chromogen present in an amount sufficient to signal ingestion and in a form not visually discernible in said composition but capable of producing a contrasting color upon contacting an activator substance upon ingestion.
Claim 3
Dependent Claim
16 words
The composition in accordance with claim 1 wherein the signal means is contained within disintegratable microcapsules.
Claim 4
Dependent Claim
34 words
The composition in accordance with claim 1 wherein the chromogen is a liquid or water-soluble substance which is generally white or colorless and which converts to a colored form upon contact with body fluids.
Claim 5
Dependent Claim
19 words
The composition in accordance with claim 3 wherein said chromogen is in liquid form and is contained within microcapsules.
Claim 6
Dependent Claim
12 words
The composition in accordance with claim 2 wherein the microcapsules are pressure-rupturable.
Claim 7
Dependent Claim
30 words
The composition in accordance with claim 2 wherein said aqueous continuous phase is alkaline and wherein said microcapsules are soluble in an acidic medium but insoluble in an alkaline medium.
Claim 8
Dependent Claim
29 words
The composition in accordance with claim 2 wherein said chromogen is colorless while contained within said microcapsules and converts to a colored form upon contact with a body fluid.
Claim 9
Dependent Claim
30 words
The composition in accordance with claim 2 wherein said chromogen is substantially white while contained within said microcapsules and converts to a colored form upon contact with a body fluid.
Claim 10
Dependent Claim
15 words
The composition in accordance with claim 2 wherein the microcapsules are soluble in gastro-intestinal juices.
Claim 11
Dependent Claim
25 words
The composition in accordance with claim 2 wherein the chromogen produces a contrasting color upon physical rupture of the microcapsules and contact with lead-based paint.
Claim 12
Dependent Claim
12 words
The composition in accordance with claim 1 additionally containing an acerbic agent.
Claim 13
Dependent Claim
18 words
The composition in accordance with claim 1 wherein the chromogen is a leuco base of a non-toxic dye.
Claim 14
Dependent Claim
14 words
The composition in accordance with claim 12 wherein the dye is an xanthene dye.
Claim 15
Dependent Claim
14 words
The composition in accordance with claim 12 wherein the dye is a thiazine dye.
Claim 16
Dependent Claim
14 words
The composition in accordance with claim 12 wherein the dye is a triphenylmethane dye.
Claim 17
Dependent Claim
16 words
The composition in accordance with claim 1 wherein the chromogen is an amino acid-sensitive, color-producing reagent.
Claim 18
Dependent Claim
14 words
The composition in accordance with claim 1 wherein the chromogen is a metallochromic indicator.
Claim 19
Dependent Claim
20 words
The composition in accordance with claim 1 wherein the chromogen produces a contrasting color upon mastication and contact with saliva.
Claim 20
Dependent Claim
21 words
The composition in accordance with claim 1 wherein the chromogen produces a contrasting color upon ingestion and contact with gastric juices.
Claim 21
Dependent Claim
60 words
A dry signal coating comprising a substantially continuous polymeric film comprising coalesced latex particles having incorporated therein a masked, physiologically acceptable chromogen which normally is not visually discernible but which, upon release when the polymer film is ruptured, produces a contrasting color upon contacting an activator substance upon ingestion; said chromogen being present in an amount sufficient to signal ingestion.
Claim 22
Dependent Claim
60 words
A dry signal coating comprising a substantially continuous polymeric film comprising coalesced latex particles having incorporated therein a masked, physiologically acceptable chromogen which normally is not visually discernible but which, upon release when the polymer film is ruptured, produces a contrasting color upon contacting an activator substance upon ingestion; said chromogen being present in an amount sufficient to signal ingestion.
Claim 23
Dependent Claim
17 words
The signal coating in accordance with claim 20 wherein said chromogen is contained within discrete, pressure-rupturable microcapsules.
Claim 24
Dependent Claim
16 words
The signal coating in accordance with claim 20 wherein said polymeric film additionally contains a pigment.
Claim 25
Dependent Claim
27 words
The composition in accordance with claim 1 wherein the chromogen is present in an amount of about 0.01 to about 3 percent by weight of the composition.
Claim 26
Dependent Claim
27 words
The composition in accordance with claim 1 wherein the chromogen is present in an amount of about 0.05 to about 1.5 percent by weight of the composition.
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) | 1981-01-09 | 1981-07-11 | 1982-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-09 | 1985-07-11 | 1986-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-09 | 1989-07-11 | 1990-01-10 | $7700.00 | Window Closed / Lapsed |