US3758534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of metal chelates
Assignee: WR Grace and Co Conn
•
Filing: 1971-09-15
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Granted: 1973-09-11
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Expires: 1991-09-15
Abstract
Abstract An alkali metal salt of a polyvalent metal chelate of a chelating aminoacetic acid is formed by: 1. Boiling a mixture of; (a) water; (b) an amine precursor of the said acid; (c) formaldehyde; (d) a cyanide of the polyvalent metal; and (e) an alkali metal cyanide, and adding thereto the chelating aminoacetic acid in its free form to react with unreacted polyvalent metal cyanide 2. Boiling a mixture of; (a) water; (b) an amine precursor of the said acid; (c) formaldehyde; (d) a polyvalent metal hydroxide or oxide; (e) an an alkali metal hydroxide; and (f) hydrogen cyanide and adding thereto the chelating aminoacetic acid in its free form to react with unreacted polyvalent metal hydroxide or oxide.
Inventors
- 👤 F Popper
- 👤 A Levesque
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:27
CPC Classifications
C; C05; C05D; C05D9/00; C05D9/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
47 words
BOILING A MIXTURE OF; (A) WATER; (B) AN AMINE PRECURSOR OF THE SAID ACID; (C) FORMALDEHYDE; (D) A CYANIDE OF THE POLYVALENT METAL; AND (E) AN ALKALI METAL CYANIDE, AND ADDING THERETO THE CHELATING AMINOACETIC ACID IN ITS FREE FORM TO REACT WITH UNREACTED POLYVALENT METAL CYANIDE
Claim 2
Dependent Claim
47 words
BOILING A MIXTURE OF; (A) WATER; (B) AN AMINE PRECURSOR OF THE SAID ACID; (C) FORMALDEHYDE; (D) A CYANIDE OF THE POLYVALENT METAL; AND (E) AN ALKALI METAL CYANIDE, AND ADDING THERETO THE CHELATING AMINOACETIC ACID IN ITS FREE FORM TO REACT WITH UNREACTED POLYVALENT METAL CYANIDE
Claim 3
Dependent Claim
53 words
BOILING A MIXTURE OF; (A) WATER; (B) AN AMINE PRECURSOR OF THE SAID ACID; (C) FORMALDEHYDE; (D) A POLYVALENT METAL HYDROXIDE OR OXIDE; (E) AN AN ALKALI METAL HYDROXIDE; AND (F) HYDROGEN CYANIDE AND ADDING THERETO THE CHELATING AMINOACETIC ACID IN ITS FREE FORM TO REACT WITH UNREACTED POLYVALENT METAL HYDROXIDE OR OXIDE.
Claim 4
Dependent Claim
53 words
BOILING A MIXTURE OF; (A) WATER; (B) AN AMINE PRECURSOR OF THE SAID ACID; (C) FORMALDEHYDE; (D) A POLYVALENT METAL HYDROXIDE OR OXIDE; (E) AN AN ALKALI METAL HYDROXIDE; AND (F) HYDROGEN CYANIDE AND ADDING THERETO THE CHELATING AMINOACETIC ACID IN ITS FREE FORM TO REACT WITH UNREACTED POLYVALENT METAL HYDROXIDE OR OXIDE.
Claim 5
Dependent Claim
64 words
The process of claim 1 in which the amine precursor of the chelating amino acid, the formaldehyde, the polyvalEnt metal base, and the hydrogen cyanide are admixed in an equivalent ratio of about 1:1-2.5:1-1.5:1-1.25, and the water is supplied in such an amount that the concentration of said alkali metal salt of said polyvalent metal chelate in said aqueous solution is about 25-50 percent.
Claim 6
Dependent Claim
46 words
The process of claim 1 in which the chelating aminoacetic acid in its free form is added in an amount to adjust the pH of said aqueous solution of said alkali metal salt of said polyvalent metal chelate of said chelating aminoacetic acid to about 4-8.
Claim 7
Dependent Claim
20 words
The process of claim 1 in which the polyvalent metal base is a hydroxide or oxide of calcium or magnesium.
Claim 8
Dependent Claim
17 words
The process of claim 1 in which the polyvalent base is a hydroxide or oxide of zinc.
Claim 9
Dependent Claim
17 words
The process of claim 1 in which the alkali metal hydroxide is sodium hydroxide or potassium hydroxide.
Claim 10
Dependent Claim
16 words
The process of claim 1 in which the pH of said resulting mixture is about 9-14.
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) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |