Automatic dishwashing method

Patent metadata

Field	Value
Publication number	US-11414629-B2
Application number	US-202016876150-A
Country	US
Kind code	B2
Filing date	May 18, 2020
Priority date	May 22, 2019
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

A method of washing dishware in a dishwasher comprising the step of delivering into the dishwasher: a) a first composition comprising oxygen bleach and substantially free of enzymes; followed by b) a second composition comprising enzymes wherein the first composition has a pH of at least 11 and the pH of the first composition is at least 1 pH unit greater the pH of the second composition wherein the pH is measured at wash concentration at 20° C.

First claim

What is claimed is:

1. A method of washing dishware in a dishwasher, the method comprising:
a) delivering a first composition into a wash liquor, the first composition comprising oxygen bleach and substantially free of enzymes; followed by
b) reducing the pH of the wash liquor, wherein the reducing the pH of the wash liquor comprises delivering an intermediate composition to the wash liquor between the delivering the first composition and the delivering the second composition, and wherein the intermediate composition comprises a pH buffering system, wherein the pH buffering system comprises citric acid and optionally, sodium bicarbonate; followed by
c) delivering a second composition into the wash liquor, the second composition comprising enzymes;

wherein the first composition has a pH of at least 11 and the pH of the first composition is at least 1 pH unit greater the pH of the second composition, and wherein the pH is measured at wash concentration at 20° C.

2. The method according to claim 1 , wherein the pH of the first composition is at least 1.2 pH units greater the pH of the second composition, and wherein the pH is measured at wash concentration at 20° C.

3. The method according to claim 1 , wherein the oxygen bleach of the first composition comprises percarbonate.

4. The method according to claim 1 , wherein the first composition further comprises a cleaning agent selected from the group consisting of alkalinity source, complexing agent, builder, polymer, bleach catalyst, bleach activator, surfactant and mixtures thereof.

5. The method according to claim 1 , wherein the first composition comprises an alkalinity source, and wherein the alkalinity source comprises sodium hydroxide.

6. The method according to claim 1 , wherein the first composition further comprises methyl glycine diacetic acid.

7. The method according to claim 1 , wherein the intermediate composition has calcium binding properties.

8. The method according to claim 1 , wherein the enzymes comprise amylase and protease.

9. The method according to claim 1 , wherein the first composition and the second composition are delivered into a main wash cycle of the dishwasher.

10. The method according to claim 1 , wherein the first composition, the second composition, and the intermediate composition are delivered from a dosing system, and wherein the dosing system is located in the dishwasher.

Assignees

• Procter & Gamble

Inventors

• Letzelter Nathalie Sophie
• Soper Shari Joy
• Amos Sylvan
• Delgado Kristopher L
• Stowe Elliott
• Galea Sarah

Classifications

• C11D3/386 Primary

  Preparations containing enzymes {, e.g. protease or amylase} · CPC title

• B08B3/08

  the liquid having chemical or dissolving effect · CPC title

• C11D3/3956 Primary

  Liquid compositions · CPC title

• C11D3/2086

  Hydroxy carboxylic acids-salts thereof · CPC title

• A47L15/0007

  Washing phases · CPC title