Detergent Gel via Polyacrylic Acid pH Cycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing detergent compositions, especially aqueous systems, face challenges in achieving high active agent concentrations while maintaining a self-standing gel form that is aesthetically appealing and resistant to leakage, without relying on conventional thickeners which often compromise cleaning performance.
Innovation Solution
A method involving an aqueous composition with citrate salt, sequential pH adjustments using polyacrylic acid and alkali metal carbonate/bicarbonate, and staged addition of polyacrylic acid to create a self-standing gel without the need for conventional thickeners, allowing for higher active agent incorporation and improved physical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional thickeners (xanthan gum, crosslinked polyacrylic acid) are added to aqueous detergent compositions to achieve self-standing gel form, then the composition becomes non-flowable and resistant to leakage, but the cleaning performance is compromised due to dilution with non-active thickener material
Solution Approach 1:
The invention extracts and removes conventional thickeners (xanthan gum, crosslinked polyacrylic acid) from the formulation entirely. Instead, it uses a novel thickening system based on partially neutralized polyacrylic acid (5-20 wt%) combined with citrate salts (10-30 wt%) and alkali metal carbonate/bicarbonate (5-20 wt%), which provides both thickening and cleaning functionality, thereby eliminating the need for non-active thickener material that dilutes active agents.
Solution Approach 2:
The polyacrylic acid-citrate-carbonate system performs multiple functions simultaneously: it acts as a thickening agent to create self-standing gel structure, provides cleaning activity through citrate and polyacrylic acid, and maintains stability without requiring separate non-active thickener components. This multi-functionality resolves the contradiction by making the thickener system itself contribute to cleaning performance.
2Quantity of substance
If high concentrations of active cleaning agents are incorporated into detergent compositions, then cleaning performance is improved, but the composition becomes flowable and prone to leakage, losing the self-standing gel structure
Solution Approach 1:
The invention changes the rheological parameters of the composition by using partially neutralized polyacrylic acid (5-20 wt%) with specific molecular weight (1000-6000) in combination with citrate salts (10-30 wt%) and alkali metal carbonate/bicarbonate (5-20 wt%). This parameter optimization creates a self-standing gel structure that can maintain high active agent concentrations (up to 50-70 wt% in some embodiments) while remaining non-flowable and resistant to leakage.
3Illumination intensity
If transparent or translucent formulations are prepared to achieve aesthetic appeal, then visual appearance is improved, but the concentration of non-dissolved active agents must be limited to allow light to pass through
Solution Approach 1:
The invention applies local quality by allowing the detergent composition to be opaque while maintaining aesthetic appeal through proper formulation. The polyacrylic acid-citrate-carbonate system creates a homogeneous opaque gel structure that is aesthetically pleasing and does not require transparency. This allows maximum incorporation of non-dissolved active agents (enzymes, bleaches, surfactants) without compromising visual appeal, as the opacity itself becomes the aesthetic feature rather than a limitation.
Data Source
AI summary
The present invention provides a method of making a detergent composition, the method comprising the following steps in the recited order: (a) providing an aqueous composition comprising a citrate salt; (b) lowering the pH by adding a first, un-neutralised or partially neutralised, polyacrylic acid having a weight average molecular weight in the range of 1000 to 6000 to form a second mixture; (c) increasing the pH by adding alkali metal carbonate and/or alkali metal bicarbonate to form a third mixture; and (d) adding a second polyacrylic acid having a weight average molecular weight in the range of 1000 to 6000 to form a fourth mixture; wherein the detergent composition is preferably an automatic dishwashing detergent composition or a laundry detergent composition.