US3839098A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composition and method for producing black coating on brass
Assignee: Conversion Chemical Corp
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Filing: 1972-11-09
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Granted: 1974-10-01
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Expires: 1992-11-09
Abstract
Abstract An aqueous bath for imparting a black surface coating to brass workpieces is provided by an aqueous solution of cupric carbonate, an organic color intensifier, and ammonium hydroxide in an amount sufficient to provide a pH of about 11.0 to 12.5. The workpieces are immersed in the bath, preferably at ambient temperature, for a period of time sufficient to develop a uniform, deep black finish thereon. The color intensifier may be aliphatic and aromatic ketones, aliphatic and aromatic amines, aliphatic alcohols, oxidation-resistant hydroxybenzene compounds, aromatic phosphonic and sulfonic acids, and mixtures thereof.
Inventors
- 👤 M Beckwith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:28
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/60; C23C22/63
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
97 words
AN AQUEOUS BATH FOR IMPARTING A BLACK SURFACE COATING TO BRASS WORKPIECES CONSISTING ESSENTIALLY OF AN AQUEOUS SOLUTION OF: ABOUT 35 TO 435 GRAMS PER LITER OF CUPRIC CARBONATE; ABOUT 1 TO 30 GRAMS PER 100 GRAMS OF CUPRIC CARBONATE OF AN ORGANIC COLOR INTENSIFIER SELECTED FROM THE GROUP CONSISTING OF ALIPHATIC AND AROMATIC CARBOXYLIC ACIDS, ALIPHATIC AD AROMATIC ALDEHYDES, ALIPHATIC AND AROMATIC KETONES, ALIPHATIC AND AROMATIC AMINES, ALIPHATIC ALCOHOLS, OXIDATION-RESISTANT HYDROXYBENZENE COMPOUNDS, AROMATIC PHOSPHONIC AND SULFINIC ACIDS AND MIXTUTES THEREOF; AND AMMONIUM HYROXIDE IN AN AMOUNT SUFFICIENT TO PROVIDE A PH F ABOUT 11.0 TO 12.5.
Claim 2
Dependent Claim
97 words
AN AQUEOUS BATH FOR IMPARTING A BLACK SURFACE COATING TO BRASS WORKPIECES CONSISTING ESSENTIALLY OF AN AQUEOUS SOLUTION OF: ABOUT 35 TO 435 GRAMS PER LITER OF CUPRIC CARBONATE; ABOUT 1 TO 30 GRAMS PER 100 GRAMS OF CUPRIC CARBONATE OF AN ORGANIC COLOR INTENSIFIER SELECTED FROM THE GROUP CONSISTING OF ALIPHATIC AND AROMATIC CARBOXYLIC ACIDS, ALIPHATIC AD AROMATIC ALDEHYDES, ALIPHATIC AND AROMATIC KETONES, ALIPHATIC AND AROMATIC AMINES, ALIPHATIC ALCOHOLS, OXIDATION-RESISTANT HYDROXYBENZENE COMPOUNDS, AROMATIC PHOSPHONIC AND SULFINIC ACIDS AND MIXTUTES THEREOF; AND AMMONIUM HYROXIDE IN AN AMOUNT SUFFICIENT TO PROVIDE A PH F ABOUT 11.0 TO 12.5.
Claim 3
Dependent Claim
22 words
The bath of claim 1 wherein said solution contains about 45 to 75 grams of said cupric carbonate per liter of solution.
Claim 4
Dependent Claim
24 words
The bath of claim 1 wherein said solution contains about 15 to 25 grams of said organic intensifier per 100 grams of cupric carbonate.
Claim 5
Dependent Claim
16 words
The bath of claim 1 wherein said solution has a pH of about 11.5 to 12.0.
Claim 6
Dependent Claim
14 words
The bath of claim 1 wherein said organic color intensifier is a carboxylic acid.
Claim 7
Dependent Claim
15 words
The bath of claim 5 wherein said organic color intensifier is an aliphatic polycarboxylic acid.
Claim 8
Dependent Claim
13 words
The bath of claim 6 wherein said organic color intensifier is tartaric acid.
Claim 9
Dependent Claim
13 words
The bath of claim 6 wherein said organic color intensifier is citric acid.
Claim 10
Dependent Claim
47 words
The bath of claim 1 wherein said solution contains about 45 to 75 grams per liter of cupric carbonate and about 15 to 25 grams of tartaric acid as said color intensifier per 100 grams of cupric carbonate, and has a pH of about 11.5 to 12.0.
Claim 11
Independent Claim
139 words
The method of imparting a black surface finish to brass comprising the steps of dissolving in water reagents to form an aqueous solution consisting essentially of about 35 to 135 grams per liter of cupric carbonate, about 1 to 30 grams per 100 grams of cupric carbonate of an organic color intensifier selected from the group consisting of aliphatic and aromatic carboxylic acids, aliphatic and aromatic aldehydes, aliphatic and aromatic ketones, aliphatic and aromatic amines, aliphatic alcohols, oxidation-resistant hydroxybenzene compounds, aromatic phosphonic and sulfonic acids, and mixtures thereof; and ammonium hydroxide in an amount sufficient to provide a pH of about 11.0 to 12.5; maintaining said solution at a temperature of about 20 to 50* C; and immersing in said solution a workpiece having a brass surface for a period of time sufficient to develop a black finish thereon.
Claim 12
Independent Claim
139 words
The method of imparting a black surface finish to brass comprising the steps of dissolving in water reagents to form an aqueous solution consisting essentially of about 35 to 135 grams per liter of cupric carbonate, about 1 to 30 grams per 100 grams of cupric carbonate of an organic color intensifier selected from the group consisting of aliphatic and aromatic carboxylic acids, aliphatic and aromatic aldehydes, aliphatic and aromatic ketones, aliphatic and aromatic amines, aliphatic alcohols, oxidation-resistant hydroxybenzene compounds, aromatic phosphonic and sulfonic acids, and mixtures thereof; and ammonium hydroxide in an amount sufficient to provide a pH of about 11.0 to 12.5; maintaining said solution at a temperature of about 20 to 50* C; and immersing in said solution a workpiece having a brass surface for a period of time sufficient to develop a black finish thereon.
Claim 13
Dependent Claim
18 words
The method of claim 10 wherein said solution is maintained at a temperature of 25 to 30* C.
Claim 14
Dependent Claim
22 words
The method of claim 10 wherein said solution contains about 45 to 75 grams of said cupric carbonate per liter of solution.
Claim 15
Dependent Claim
24 words
The method of claim 10 wherein said solution contains about 15 to 25 grams of said organic intensifier per 100 grams of cupric carbonate.
Claim 16
Dependent Claim
16 words
The method of claim 10 wherein said solution has a pH of about 11.5 to 12.0.
Claim 17
Dependent Claim
14 words
The method of claim 10 wherein said organic color intensifier is a carboxylic acid.
Claim 18
Dependent Claim
15 words
The method of claim 15 wherein said organic color intensifier is an aliphatic polycarboxylic acid.
Claim 19
Dependent Claim
13 words
The method of claim 16 wherein said organic color intensifier is tartaric acid.
Claim 20
Dependent Claim
13 words
The method of claim 16 wherein said organic color intensifier is citric acid.
Claim 21
Dependent Claim
47 words
The method of claim 10 wherein said solution contains about 45 to 75 grams per liter of cupric carbonate and about 15 to 25 grams of tartaric acid as said color intensifier per 100 grams of cupric carbonate, and has a pH of about 11.5 to 12.0.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-30 | 1978-04-01 | 1978-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-30 | 1982-04-01 | 1982-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-30 | 1986-04-01 | 1986-10-01 | $7700.00 | Window Closed / Lapsed |