Sorbate Preservative System for Fabric Detergent at High pH
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Solution Overview
Problem
The use of isothiazolinones in fabric detergents has been limited due to regulatory pressures and skin sensitization concerns, and sorbic acid's antimicrobial effectiveness is hindered by the need for low pH levels, which are undesirable in detergents.
Innovation Solution
A fabric detergent formulation incorporating sorbates as preservatives, combined with anionic surfactants in a high pH environment, achieving effective antimicrobial efficacy without isothiazolinones, with sorbates present in concentrations of 0.01 wt.% to 0.8 wt.% and anionic surfactants in a weight ratio of 10 or more, ensuring microbial challenge resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sorbic acid is used as a preservative in fabric detergent, then the formulation becomes environmentally friendly and safe for use, but the pH level must be kept low (5.5 or less) to ensure sufficient antimicrobial activity
Solution Approach 1:
The patent changes the chemical form of the preservative from sorbic acid to sorbate salts (potassium sorbate, sodium sorbate, etc.), which have different dissociation properties. This parameter change allows the preservative to remain effective at higher pH levels (6.5 or above) while maintaining antimicrobial activity, thus resolving the contradiction between safety/environmental friendliness and pH control.
Solution Approach 2:
The patent creates a composite preservative system combining sorbate salts with specific anionic surfactants (weight ratio of anionic surfactants to sorbates is about 10 or more). This composite approach enhances the overall preservative efficacy at higher pH levels, allowing the formulation to maintain both safety and effective antimicrobial activity without being constrained to low pH.
2Reliability
If isothiazolinones are used as preservatives, then effective antimicrobial protection is achieved, but regulatory pressures and skin sensitization concerns limit their use
Solution Approach 1:
The patent replaces long-standing preservatives (isothiazolinones) with alternative preservatives (sorbates) that have a history of safe use in food, pharmaceutical and personal care applications. Sorbates are considered nature identical and environmentally friendly, thus eliminating skin sensitization issues while maintaining preservative efficacy through the optimized formulation approach.
Solution Approach 2:
The patent introduces anionic surfactants as intermediaries that work synergistically with sorbate preservatives. The surfactants enhance the preservative system's ability to combat microorganisms at higher pH levels, providing effective antimicrobial protection without relying on isothiazolinones and their associated skin sensitization risks.
3Object-affected harmful factors
If pH level is increased to avoid skin sensitization and improve comfort, then user safety improves, but antimicrobial efficacy of sorbic acid decreases
Solution Approach 1:
The patent changes the preservative from sorbic acid to sorbate salts, fundamentally altering the chemical parameters. Sorbate salts dissociate differently in water compared to sorbic acid, maintaining sufficient undissociated acid form at higher pH levels (6.5 or above) to ensure antimicrobial efficacy while allowing the formulation to be safer and more comfortable for users.
Solution Approach 2:
The patent creates local conditions within the formulation by combining sorbate salts with specific anionic surfactants in a defined weight ratio (about 10 or more). This local optimization at the molecular interaction level enhances preservative efficacy specifically where needed, allowing the bulk formulation to maintain higher pH levels for user safety while still achieving effective antimicrobial protection.
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 formulation demonstrates a log reduction of at least 1 to 4 in microbial populations over several days, meeting European Pharmacopoeia standards for preservative efficacy at pH levels of 6.5 or higher, maintaining effectiveness against various microorganisms.
Implementation Method 1
sorbates as preservatives, achieving effective antimicrobial efficacy
Implementation Method 2
one or more anionic surfactants, wherein the weight ratio of the anionic surfactants to the sorbates is about 10 or more
Data Source
AI summary
A fabric detergent formulation is provided. The formulation comprises a preservative system that includes one or more sorbates in an amount of from about 0.01 wt. % to about 0.8 wt. % of the fabric detergent formulation; one or more anionic surfactants, wherein the weight ratio of the anionic surfactants to the sorbates is about 10 or more; and a solvent system that includes water in an amount of from about 50 wt. % to 100 wt. % of the fabric detergent formulation. The pH of the fabric detergent formulation is about 6.5 or more.