05.11.23
US Patent No. 11,643,619 B2 (Alias Younis Al-Bayati, Gerhard Kämmerer, Caroline Sabina Rigobert, Claudia Schmaelzle, Diego Simionato and Michela Tasinazzo); Reckitt Benckiser Finish B.V. has patented a method of an automatic dishwashing detergent composition or laundry detergent composition in the form of a gel that retains a shape and does not flow at 20° C., 1 atm pressure. The method entails the following steps:
• providing a first mixture of an aqueous composition comprising a citrate salt;
• lowering the pH of the first mixture by adding a first, un-neutralized or partially neutralized, polyacrylic acid having a weight average molecular weight in the range of 1000 to 6000 to form a second mixture;
• increasing the pH of the second mixture by adding one or both of an alkali metal carbonate and an alkali metal bicarbonate to form a third mixture; and
• adding a second polyacrylic acid having a weight average molecular weight in the range of 1000 to 6000 to form a fourth mixture.
• providing a first mixture of an aqueous composition comprising a citrate salt;
• lowering the pH of the first mixture by adding a first, un-neutralized or partially neutralized, polyacrylic acid having a weight average molecular weight in the range of 1000 to 6000 to form a second mixture;
• increasing the pH of the second mixture by adding one or both of an alkali metal carbonate and an alkali metal bicarbonate to form a third mixture; and
• adding a second polyacrylic acid having a weight average molecular weight in the range of 1000 to 6000 to form a fourth mixture.