# US 6,296,670 B1 · Chelating agents for improved color fidelity

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- Number: US 6,296,670 B1
- Document ID: US6296670B1
- Status: Granted
- Kind: B1
- Application number: 08/882,924
- Filed: 1997-06-26
- Granted: 2001-10-02
- Earliest claimed: 1995-01-12
- Assignees: The Procter & Gamble Company
- Inventors: John Robert Rusche; Ellen Schmidt Baker; Axel Masschelein
- Web page: https://patentgrep.com/patent/US6296670B1

## CPC

- C11D 3/046: {Salts}
- C11D 3/0021: {Dye-stain or dye-transfer inhibiting compositions}
- C11D 3/33: Amino carboxylic acids
- C11D 3/364: {containing nitrogen}
- C11D: DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL

## Abstract

Rinsing dyed or white fabrics in a chelator-containing rinse bath restores color and brightness. Rinse added compositions comprising chelators such as diethylenetriaminepentaacetate or ethylenediamine disuccinate are used to restore the appearance of colored and white fabrics whose drab appearance has been caused by interactions with metal ions, especially copper and nickel. Compositions comprising the chelators in combination with fabric care auxiliaries such as fabric softeners, cellulase enzymes and chlorine scavengers are provided.

## Claims

### Claim 1

A composition of matter especially adapted for use in the rinse bath of a laundering operation, comprising:
(a) at least about 0.75%, by weight, of chelating agent for copper cations, nickel cations, or mixtures thereof;
(b) more than about 10%, by weight, of cationic fabric softener;
(c) stabilizer selected from the group consisting of polyester material, water-soluble zinc salt, and mixtures thereof;
(d) optionally, dissolved electrolytes;
(e) optionally, at least about 0.01%, by weight, of chlorine scavenger;
(f) optionally, cellulase enzyme; and
(g) optionally, dye transfer inhibiting agent.

### Claim 2 (depends on 1)

A composition according to claim 1 wherein the chelating agent is ethylenediamine disuccinate and the chlorine scavenger is ammonium chloride.

### Claim 3 (depends on 1)

A composition according to claim 1 wherein the chelating agent is diethylenetriamine pentaacetate and the chlorine scavenger is ammonium chloride.

### Claim 4 (depends on 1)

A composition according to claim 1 wherein the chelating agent is diethylenetriamine-N,N,N′,N″,N″-pentakis(methane phosphonate) and the chlorine scavenger is ammonium chloride.

### Claim 5 (depends on 1)

A method for improving the color fidelity of laundered fabrics, comprising the steps of:
(a) washing dyed fabrics with a laundry detergent composition; and
(b) following said washing, rinsing said fabrics in an aqueous solution comprising the composition of claim 1 in an amount sufficient to provide at least about 2 ppm of a chelating agent for copper ions or nickel ions selected from the group consisting of amino carboxylates, amino phosphonates, polyfunctionally-substituted aromatic chelating agents and mixtures thereof.

### Claim 6 (depends on 5)

A method according to claim 5 wherein the dyed fabrics are immersed in the aqueous soltuion of Step (b) for a period of at least about 1 minute.

### Claim 7 (depends on 6)

A method according to claim 6 which is conducted at a temperature in the range from about 5° C. to the boil.

### Claim 8 (depends on 5)

A method according to claim 5 wherein the aqueous solution additionally contains a member selected from the group consisting of cellulase enzymes, chlorine scavengers, dye transfer inhibiting agent and mixtures thereof.

### Claim 9 (depends on 8)

A method according to claim 8 which is conducted in the presence of a dye transfer inhibiting agent selected from the group consisting of polyvinyl pyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, manganese phthalocyanine, peroxidases, and mixtures thereof.

### Claim 10 (depends on 8)

A method according to claim 8 which is conducted in the presence of a chlorine scavenger selected from the group consisting of ammonium chloride, monoethanolamine, diethanolamine, tris(hydroxymethyl)aminomethane, hexamethylenetetramine, arginine, histidine, polyarginine, polylysine, polyhistidine, water-soluble polyethyleneimines, polyamines, polyvinylamines, polyamineamides, polyacrylamides, and mixtures thereof.

### Claim 11 (depends on 10)

A method according to claim 10 which is conducted in the presence of a cellulase enzyme.

### Claim 12 (depends on 8)

A method according to claim 8 which is conducted in the presence of an ester-derived cationic softener selected from the group consisting of compounds having the formula (I) and (II), below:
wherein Q is —O—C(O)— or —C(O)—O— or —O—C(O)—O— or —NR4—C(O)— or —C(O)—
NR4—; or mixtures thereof;
R1 is (CH2)n—Q—T2 or T3;
R2 is (CH2)m—Q—T4 or T5 or R3;
R3 is C1-C4 alkyl or C1-C4 hydroxyalkyl or H;
R4 is H or C1-C4 alkyl or C1-C4 hydroxyalkyl;
T1, T2, T3, T4, T5 are the same or different C11-C22 alkyl or alkenyl group;
n and m are integers from 1 to 4; and
X− is a softener-compatible anion.