US4353950A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stain-resistant cookware multi-layer coating system comprising pigments and a transluscent outer layer
Assignee: EIDP Inc
•
Filing: 1979-07-06
•
Granted: 1982-10-12
•
Expires: 1999-07-06
Abstract
Abstract Heat-stable coatings on cookware can be made stain-resistant by including a pigmented brown intermediate layer and a clear topcoat layer containing mica or coated mica platelets for sparkle. Such coatings are particularly suitable for electrical cookware.
Inventors
- 👤 Eustathios Vassiliou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:10
CPC Classifications
B; B05; B05D; B05D7/00; B05D7/50; B05D7/56; B05D7/57; A; A47; A47J; A47J36/00; A47J36/02; B05D5/00; B05D5/06; B05D5/067; B05D5/068; B05D5/08; B05D5/083; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24851; Y10T428/24868; Y10T428/24876; Y10T428/25; Y10T428/251; Y10T428/31504; Y10T428/3154; Y10T428/31544; Y10T428/31678; Y10T428/31681; Y10T428/31721; Y10T428/31786
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
103 words
A cookware article comprising a substrate coated with a heat-stable coating system comprising three layers, each layer containing a polymer stable at temperatures above 300° C., said layers including a primer layer in direct contact with the substrate and which adheres the coating system to the substrate, an intermediate layer in contact with the primer layer and containing pigments which mask the brown color of food stains that develop in the coating system during cooking, and a light-transmitting topcoat layer in contact with the intermediate layer and containing mica or mica platelets coated with pigment, giving a sparkling appearance to the coating system.
Claim 2
Dependent Claim
103 words
A cookware article comprising a substrate coated with a heat-stable coating system comprising three layers, each layer containing a polymer stable at temperatures above 300° C., said layers including a primer layer in direct contact with the substrate and which adheres the coating system to the substrate, an intermediate layer in contact with the primer layer and containing pigments which mask the brown color of food stains that develop in the coating system during cooking, and a light-transmitting topcoat layer in contact with the intermediate layer and containing mica or mica platelets coated with pigment, giving a sparkling appearance to the coating system.
Claim 3
Dependent Claim
64 words
The article of claim 1 in which the heat-stable polymer is a silicone, polysulfide, polymerized parahydroxy-benzoic acid, a polysulfone, a polyimide, a polyamide, a salt of a polyamic acid, a polysulfonate, a polysulfonamide, a fluorocarbon polymer, or a mixture of two or more of the above, and said heat-stable polymers are the same or in any combination in the three layers of the coating.
Claim 4
Dependent Claim
20 words
The article of claim 1 in which the intermediate layer includes red iron oxide pigment, carbon black, and an antioxidant.
Claim 5
Dependent Claim
16 words
The article of claim 3 in which the antioxidant is a phosphorus, sulfur, or boron compound.
Claim 6
Dependent Claim
12 words
The article of claim 4 in which the antioxidant is phosphoric acid.
Claim 7
Dependent Claim
15 words
The article of claim 1 in which the intermediate layer includes black iron oxide pigment.
Claim 8
Dependent Claim
13 words
The article of claim 1 in which the intermediate layer includes burnt umber.
Claim 9
Dependent Claim
12 words
The article of claim 1 in which the topcoat contains an antioxidant.
Claim 10
Dependent Claim
94 words
The coated article of claim 8 in which the topcoat contains (a) about 80-99.8%, by weight of the total of (a) and (b), of a particulate polymer polymerized or copolymerized from monomers selected from one or more monoethylenically unsaturated hydrocarbon monomers and hydrocarbon ether monomers, said monomers being completely substituted with fluorine atoms or a combination of fluorine atoms and chlorine atoms, and (b) about 0.2-20%, by weight of the total of (a) and (b), of mica particles, mica particles coated with pigment, or metal flake; the total of (a) and (b) equaling 100%.
Claim 11
Dependent Claim
18 words
The article of claim 9 in which the topcoat includes polytetrafluoroethylene or a compolymer of tetrafluoroethylene and hexafluoropropylene.
Claim 12
Dependent Claim
11 words
The article of claim 1 containing an electrical resistance heat source.
Claim 13
Dependent Claim
30 words
The article of claim 11 in which the electrical heat source is in the form of a discrete pattern on the opposite side of the substrate from the coating system.
Claim 14
Dependent Claim
45 words
The article of claim 1 in which the primer includes the salt of a polyamic acid and colloidal silica; the intermediate layer includes red iron oxide pigment, carbon black, and phosphoric acid; and the topcoat includes polytetrafluoroethylene, and mica platelets coated with titanium dioxide pigment.
Claim 15
Dependent Claim
50 words
The article of claim 1 in which the primer includes the salt of a polymeric acid and colloidal silica; the intermediate layer includes red iron oxide pigment, carbon black, and phosphoric acid; and the topcoat includes a copolymer of tetrafluoroethylene and hexafluoropropylene, and mica platelets coated with titanium dioxide pigment.
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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) | 1985-10-11 | 1986-04-12 | 1986-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-11 | 1990-04-12 | 1990-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-11 | 1994-04-12 | 1994-10-12 | $7700.00 | Window Closed / Lapsed |