Patent US3615730A successfully refreshed from Google Patents.
US3615730A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protective coating
Assignee: Amercoat Corp
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Filing: 1970-02-05
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Granted: 1971-10-26
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Expires: 1990-02-05
Abstract
Abstract An inorganic zinc-rich coating for the protection of ferrous surfaces consisting of zinc dust in a vehicle comprising a substantially nonaqueous colloidal suspension of silica in ethylene glycol monoethyl ether or other polar solvent. Small amounts of zinc chloride and, optionally, magnesium oxide are added to the vehicle to promote film hardness. The coating may be prepared by fractional distillation of an aqueous, acidstabilized colloidal silica sol premixed with a polar solvent, with subsequent addition of zinc chloride, magnesium oxide and zinc dust to the solvent dispersion.
Inventors
- 👤 Gabriel H Law
- 👤 Paul D Van Dorsten
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:25
CPC Classifications
C; C09; C09D; C09D5/00; C09D5/08; C09D5/10
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
29 words
A protective coating as defined in claim 1 further comprising from 0.5 to 3 parts by weight of zinc chloride for each 100 parts by weight of zinc dust.
Claim 2
Dependent Claim
32 words
A protective coating as defined in claim 2 further comprising magnesium oxide in concentration of less than about 0.4 parts by weight for each 1 part by weight of said zinc chloride.
Claim 3
Dependent Claim
46 words
A protective coating as defined in claim 1 wherein said zinc dust comprises particles having a size range of from about 4 to about 10 microns, and wherein said colloidal silica comprises SiO2 having an average particle size of from about 16 to about 22 millimicrons.
Claim 4
Dependent Claim
76 words
A protective coating for metal surfaces comprising: a substantially nonaqueous, acidic colloidal suspension of silica in ethylene glycol monoethyl ether, the concentration of said silica being from 30 to 60 percent by weight of said suspension, from 5 to 25 parts by weight of zinc dust for each 1 part by weight of said silica, and from 0.5 to 3 parts by weight of zinc chloride for each 100 parts by weight of said zinc dust.
Claim 5
Dependent Claim
58 words
A protective coating as defined in claim 5 wherein said suspension further comprises an additional polar solvent selected from the class consisting of isopropyl alcohol, butyl alcohol, methyl isobutyl ketone and butyl acetate, the weight amount of said additional solvent being less than 2.5 times the combined weight amount of said silica and said ethylene glycol monoethyl ether.
Claim 6
Dependent Claim
56 words
A protective coating as defined in claim 5 wherein said suspension further comprises an additional polar solvent selected from the class consisting of xylol, toluol or high-flash naptha, the concentration of said additional polar solvent being less than about 50 parts by weight for each 100 parts by weight combined silica and ethylene glycol monoethyl ether.
Claim 7
Independent Claim
77 words
A method of making a protective coating for metal surfaces, comprising the steps of: combining a polar solvent with an acid-stabilized, aqueous colloidal silica sol, said solvent consisting of monoethylene glycol monoethyl ether, fractionally distilling said combined solvent and sol to eliminate substantially all water therefrom, and to provide a resultant suspension wherein the concentration of said silica is from 30 to 60 percent by weight, and adding zinc chloride and zinc dust to said resultant suspension.
Claim 8
Dependent Claim
24 words
The method defined in claim 8 wherein said fractional distillation is accomplished under vacuum and at a teMperature on the order of 50* C.
Claim 9
Dependent Claim
59 words
The method defined in claim 8 wherein the concentration of said zinc dust is from 5 to 25 parts by weight for each 1 part by weight of said silica, and wherein the concentration of said zinc chloride is from 0.5 to 3 parts by weight of zinc chloride for each 100 parts by weight of said zinc dust.
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) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |