Acidic Laundry Detergent with Controlled pH for Residue Removal

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Solution Overview

Problem

Conventional laundry detergents struggle to effectively remove residues and stains, particularly from complex mixtures of body soils, detergent, fabric softener, and hard water deposits, leading to dinginess and poor grease stain removal, while acidic detergents often result in uncontrolled sudsing and inadequate cleaning.

Innovation Solution

A laundry detergent composition with a pH of around 6, comprising a surfactant system with a Hydrophilic Index greater than 9, an organic acidulant, and an alkaline neutralizer to achieve a pH between 2.5 and 3.0, which is designed to break up dingy deposits and improve grease and bleachable stain removal without excessive sudsing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional basic pH detergents are used, then surfactant solubility and grease stain removal are improved, but residue removal and fabric whiteness are insufficient

Engineering Contradiction:
Improvesurfactant solubilityVSAvoidresidue accumulation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the pH parameter from conventional basic (above 7) to acidic (around 6), which fundamentally alters the chemical environment. This pH modification enables the detergent to effectively remove residues and stains while maintaining surfactant solubility and dispersion in the wash water, resolving the contradiction between basic pH benefits and residue removal needs.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If acidic laundry detergent formulations are used, then residue removal and fabric whiteness are improved, but suds control and grease stain cleaning are inadequate

Engineering Contradiction:
Improveresidue removalVSAvoidsuds control
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent optimizes the pH parameter to a specific range (around 6) rather than using strongly acidic formulations. This controlled pH adjustment, combined with specific surfactant selections, achieves effective residue removal while maintaining adequate suds control and grease stain cleaning performance.

Inventive Principle:
Principle #35Parameter changes

3Object-generated harmful factors

If low pH detergents are used, then bleachable stain removal is improved, but fabric dinginess increases due to poor cleaning

Engineering Contradiction:
Improvebleachable stain removalVSAvoidfabric dinginess
Core Design Contradiction:
Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The patent adjusts the pH parameter to an optimized level (around 6) that balances stain removal capability with fabric care. This moderate acidic pH effectively removes bleachable stains like tea and wine while avoiding the excessive acidity that causes fabric dinginess and damage.

Inventive Principle:
Principle #35Parameter changes

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 detergent composition effectively reduces fabric dinginess and improves cleaning of grease and bleachable stains like taco grease and wine, while maintaining controlled sudsing and effective stain removal.

Implementation Method 1

an organic acidulant at a level such that the ratio of surfactant system to organic acidulant is less or equal to about 3.0 and an alkaline neutralizer added in an amount necessary to raise the neat pH of the detergent composition above or equal to about 2.5 but no higher than or equal to about 3.0

Methodology Applied
Scientific EffectpH adjustment:

Implementation Method 2

a surfactant system comprising surfactants selected from the group consisting of anionic surfactants, nonionic surfactants, cationic surfactants and mixtures thereof, wherein the surfactant system has a Hydrophilic Index of greater than or equal to about 9.00

Methodology Applied
Scientific EffectSurfactant action: Surfactant

Implementation Method 3

an alkaline neutralizer added in an amount necessary to raise the neat pH of the detergent composition above or equal to about 2.5 but no higher than or equal to about 3.0

Methodology Applied
Scientific EffectpH neutralization:

Data Source

PatentUS8729007B2Acidic laundry detergent compositions comprising alkyl benzene sulfonate
Publication Date: 2014.05.20 PROCTER & GAMBLE CO

AI summary

An acidic laundry detergent composition comprising less than about 20% of a surfactant system comprising surfactants selected from the group consisting of anionic surfactants, nonionic surfactants, cationic surfactants and mixtures thereof, wherein the surfactant system has a Hydrophilic Index of greater than or equal to about 9.00 and an organic acidulant at a level such that the ratio of surfactant system to organic acidulant is less or equal to about 3.0 and an alkaline neutralizer added in an amount necessary to raise the neat pH of the detergent composition above or equal to about 2.5 but no higher than or equal to about 3.0.