Method of laundering fabric

Patent metadata

Field	Value
Publication number	US-12281283-B2
Application number	US-202017061585-A
Country	US
Kind code	B2
Filing date	Oct 2, 2020
Priority date	Oct 11, 2019
Publication date	Apr 22, 2025
Grant date	Apr 22, 2025

Abstract

A method of laundering fabrics includes: a) contacting a laundry detergent to water to form a wash liquor, wherein the laundry detergent includes detersive surfactant, wherein the wash liquor includes detersive surfactant at a concentration in the range of from 100 ppm to 2500 ppm; b) contacting fabric to the wash liquor, and washing the fabric in the wash liquor; c) after a period of time of at least 6 minutes from contacting the fabric to the wash liquor, introducing calcium cations into the wash liquor to form a calcium enriched wash liquor, wherein the calcium enriched wash liquor includes calcium cations at a concentration in the range of from 20 ppm to 400 ppm; d) washing the fabric in the calcium-enriched wash liquor for a period of time of at least 2 minutes; and e) removing the excess calcium-enriched wash liquor from the fabric, and rinsing the fabric in water.

First claim

What is claimed is:

1. A method of laundering fabrics, comprising the steps of:
(a) contacting a laundry detergent to water to form a wash liquor, wherein the laundry detergent comprises detersive surfactant, and wherein the wash liquor comprises detersive surfactant at a concentration in the range of from about 100 ppm to about 2500 ppm;
(b) contacting fabric to the wash liquor, and washing the fabric in the wash liquor;
(c) after a period of time of at least about 6 minutes from contacting the fabric to the wash liquor, introducing calcium cations into the wash liquor to form a calcium enriched wash liquor, wherein the calcium enriched wash liquor comprises calcium cations at a concentration in the range of from about 20 ppm to about 400 ppm;
(d) washing the fabric in the calcium-enriched wash liquor for a period of time of at least about 2 minutes; and
(e) removing the excess calcium-enriched wash liquor from the fabric and rinsing the fabric in water.

2. A method according to claim 1 , wherein the laundry detergent comprises chelant, and optionally other detergent ingredients.

3. A method according to claim 1 , wherein the laundry detergent comprises detersive surfactant, and the wash liquor formed in step (a) comprises detersive surfactant at a concentration in the range of from about 300 ppm to about 2500 ppm.

4. A method according to claim 1 , wherein the detersive surfactant comprises alkyl benzene sulphonate.

5. A method according to claim 1 , wherein the calcium cations in step (c) are introduced into the wash liquor in the form of an aqueous calcium slurry, wherein the aqueous calcium slurry comprises from about 5 wt % to about 80 wt % calcium salt.

6. A method according to claim 5 , wherein the aqueous calcium slurry is formed by contacting calcium cations to water to form an aqueous calcium slurry comprising calcium cations at a concentration in the range of from about 5 wt % to about 80 wt % calcium salt.

7. A method according to claim 1 , wherein the calcium enriched wash liquor formed in step (c) comprises calcium cation at a concentration in the range of from above about 100 ppm to about 300 ppm.

8. A method according to claim 1 , wherein the laundry detergent comprises chelant, and wherein the chelant is selected from hydroxyethylidene diphosphonic acid (HEDP) and salts thereof; diethylene triamine penta(methylenephosphonic) acid (DTPMP) and salts thereof.

9. A method according to claim 1 , wherein the laundry detergent comprises chelant, and the wash liquor formed in step (a) comprises chelant at a concentration in the range of from about 10 ppm to about 300 ppm.

10. A method according to claim 1 , wherein the laundry detergent comprises amylase enzyme.

11. A method according to claim 1 , wherein the laundry detergent comprises citric acid.

12. A method according to claim 1 , wherein the water introduced into step (a) is pre-treated with a chelant prior to contacting the fabric with the wash liquor in step (b).

Assignees

• Procter & Gamble

Inventors

• Bueno Romo Laura
• Amador Zamarreno Carlos
• Brooker Anju Deepali Massey
• Moon Libbi
• Souter Philip Frank
• Robles Eric San Jose

Classifications

• C11D2111/12

  Soft surfaces, e.g. textile · CPC title

• C11D3/38618

  Protease or amylase in liquid compositions only · CPC title

• C11D3/364

  containing nitrogen · CPC title

• C11D3/361

  Phosphonates, phosphinates or phosphonites · CPC title

• C11D3/2086

  Hydroxy carboxylic acids-salts thereof · CPC title