Shampoo Chelant Selectivity for Copper Removal
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Solution Overview
Problem
Existing shampoo compositions are ineffective in inhibiting the deposition and removal of copper salts from hair, as most chelants also bind calcium and magnesium, leading to hair damage and reduced color uptake during hair coloring treatments.
Innovation Solution
A shampoo composition containing 0.005% to 10% of Class I and/or Class II chelants, along with 2% to 50% detersive surfactants and 75% to 98% aqueous carrier, specifically designed to inhibit copper deposition and facilitate its removal from hair, with a pH range of 3 to 8.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional chelants are used to sequester trace redox metals, then calcium and magnesium binding is achieved, but copper removal effectiveness is reduced due to competitive binding
Solution Approach 1:
The patent applies local quality by designing chelants with specific molecular structures (Class I and Class II) that have different binding affinities for different metal ions. The chelants are engineered to preferentially bind copper ions over calcium and magnesium ions through optimized functional groups and molecular geometry, enabling selective copper removal while maintaining the ability to handle hard water conditions.
Solution Approach 2:
The patent employs parameter changes by adjusting the molecular weight, log P value, and formation constant parameters of the chelants to optimize copper binding. The chelants are designed with specific molecular weight ranges (150-500 g/mol) and formation constants (log K > 10 for copper) that enhance copper selectivity while maintaining solubility and effectiveness in shampoo formulations.
2Object-affected harmful factors
If copper is removed from water, then copper deposition on hair is reduced, but existing copper deposits on hair remain
Solution Approach 1:
The patent applies preliminary action by incorporating chelants that not only prevent copper deposition during the shampooing process but also actively remove existing copper deposits from hair. The chelants are formulated to bind copper ions both in the rinse water (preventing deposition) and on the hair surface (removing deposits), providing dual functionality in a single application.
3Reliability
If chelants with high copper affinity are used, then copper binding is enhanced, but binding to calcium and magnesium increases causing hair damage
Solution Approach 1:
The patent uses local quality by designing chelant molecules with specific structural features that create different binding sites with varying affinities. The molecular structures include functional groups and spatial arrangements that preferentially coordinate copper ions while having reduced affinity for calcium and magnesium ions, thus preventing hair damage from excessive calcium/magnesium binding.
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 shampoo effectively prevents copper deposition on hair and removes copper already deposited, enhancing hair health and color uptake during treatments.
Implementation Method 1
using chelants to sequester trace redox metals
Implementation Method 2
from about 2% to about 50% of one or more detersive surfactants
Implementation Method 3
transition metal ions, such as copper and iron, can facilitate reduction-oxidation (redox) reactions during hair coloring treatments
Data Source
AI summary
Described herein is a shampoo composition and methods of using the same, the shampoo composition including a Class I and/or Class II chelant, a detersive surfactant, and a carrier.