Liquid Fabric Softener pH-Dependent Solubility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid fabric softeners with polysiloxanes build up on fabrics over time due to their water-insolubility, leading to dull and dingy textures as they do not adequately detach during subsequent laundering cycles.
Innovation Solution
A liquid fabric softener composition incorporating a cationic softener and a long chain difatty acid as the texture enhancing component, which is water-insoluble in acidic pH but water-soluble in alkaline medium, allowing it to deposit on fabrics during laundering and detach in subsequent wash cycles, thereby preventing buildup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If polysiloxanes are used as texture enhancing components in fabric softeners, then fabric feel is improved, but the components build up on fabric over time due to water-insolubility
Solution Approach 1:
The patent changes the solubility parameter of the texture enhancing component by using long chain difatty acids that are water-insoluble at acidic pH (deposit during rinse) but water-soluble at alkaline pH (wash off during subsequent wash cycles). This pH-dependent parameter change allows the component to both deposit and detach, preventing buildup while maintaining fabric feel.
2Ease of operation
If polysiloxanes are deposited on fabric during rinse cycle, then fabric texture is enhanced, but fabric becomes duller over time due to inadequate detachment
Solution Approach 1:
The patent implements periodic deposition and removal of the texture enhancing component. During rinse cycles (acidic conditions), the long chain difatty acid deposits on fabric to enhance texture. During subsequent wash cycles (alkaline conditions), the component detaches and is washed away. This periodic action maintains fabric freshness while providing temporary texture enhancement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composition effectively changes the fabric feel by depositing a long chain difatty acid that remains on the fabric during washing and detaches in subsequent cycles, maintaining fabric freshness and preventing the dulling effect associated with polysiloxane buildup.
Implementation Method 1
the long chain difatty acid component of the liquid fabric softener is preferably present in an amount of about 0.1% to about 40% by weight of the composition. The enhancing component, in this instance, a long chain difatty acid, is water-insoluble in an acidic pH, such as during the rinse cycle occurring after washing fabrics with a detergent, yet water soluble in an alkaline medium enabling the deposited enhancing component to be detached from fabric in subsequent 'wash' cycles.
Data Source
AI summary
A liquid fabric softener composition is provided which includes a texture enhancing component, such as a long chain difatty acid, that is deposited on a fabric during laundering, the deposited enhancing component changing the “feel” of the fabric. Preferably, the deposited enhancing component substantially detaches from the fabric in subsequent laundering cycles to reduce build-up. The enhancing component is preferably water-insoluble in an acidic pH, such as during the rinse cycle occurring after washing fabrics with a detergent, yet water soluble in an alkaline medium enabling the deposited enhancing component to be detached from fabric in subsequent “wash” cycles.