Hair Dye Composition with Etidronic and Dipicolinic Acids

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing hair dye compositions using oxidation dye precursors often result in unsatisfactory dyeing power, limited color range, poor persistence against external agents, and excessive selectivity along the hair fiber.

Innovation Solution

A composition combining 2-methoxymethyl-para-phenylenediamine as an oxidation base with etidronic acid and 2,6-dipicolinic acid, along with an oxidation coupler, to enhance dyeing performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional oxidation dye precursors are used, then the dyeing process is simple, but the dyeing power is weak and color range is limited

Engineering Contradiction:

Improvedyeing process simplicityVSAvoiddyeing power

Core Design Contradiction:

Ease of manufactureVSQuantity of substance

Solution Approach 1:

The patent combines multiple oxidation dye precursors (ortho-phenylenediamine, para-phenylenediamine, ortho-aminophenol, para-aminophenol, pyrazole, pyrazolinone, pyrazolo-pyridine) with specific couplers to create a composite dyeing system. This composite approach enables intense coloration across a broad color palette while maintaining uniform selectivity along the hair fiber, resolving the contradiction between process simplicity and dyeing power.

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If conventional oxidation dye precursors are used, then the application is straightforward, but the coloring persistence against external agents is poor

Engineering Contradiction:

Improveapplication straightforwardnessVSAvoidcoloring persistence

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent modifies the chemical parameters of the dyeing composition by introducing specific compounds (etidronic acid, 2,6-dipicolinic acid) and optimizing the combination of oxidation bases with couplers. These parameter changes enhance the stability and persistence of the coloring against external agents like light and shampoo, while maintaining straightforward application procedures.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If conventional oxidation dye precursors are used, then the process is simple, but the selectivity along the hair fiber is too great

Engineering Contradiction:

Improveprocess simplicityVSAvoidcolor uniformity along fiber

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent addresses selectivity issues by carefully selecting and combining multiple oxidation bases with specific couplers, creating a system where different components work synergistically to achieve uniform color distribution. The combination of ortho- and para-phenylenediamines with appropriate couplers ensures consistent coloring from root to tip, reducing excessive selectivity while keeping the process simple.

Inventive Principle:

Principle #3Local quality

4Quantity of substance

If conventional oxidation dye precursors are used, then the initial cost is low, but the gray hair coverage is insufficient

Engineering Contradiction:

ImprovecostVSAvoidgray hair coverage

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent employs composite dyeing systems combining multiple oxidation bases (particularly ortho- and para-phenylenediamines) with specific couplers to achieve effective gray hair coverage. This composite approach provides intense, uniform coloration on depigmented fibers while maintaining cost-effectiveness through the use of established chemical components in optimized combinations.

Inventive Principle:

Principle #40Composite materials

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 achieves intense, uniform coloration with improved fastness and excellent gray hair coverage, maintaining performance even after storage.

Implementation Method 1

These oxidation bases are colorless or weakly colored compounds which, when combined with oxidizing products, can give rise, by an oxidative condensation process, to colored compounds.

Methodology Applied

Scientific EffectOxidative condensation: Oxidation

Implementation Method 2

a composition for the dyeing of keratin fibers, in particular the hair, comprising: at least one oxidation base chosen from 2-methoxymethyl-para-phenylenediamine... at least one compound chosen from etidronic acid, its salts and their mixtures, and at least one compound chosen from 2,6-dipicolinic acid, its salts and their mixtures.

Methodology Applied

Scientific EffectChelation:

Data Source

PatentUS20250049669A1Composition comprising a specific oxidation dye precursor and two specific acids

Publication Date: 2025.02.13 LOREAL SA

AI summary

The invention relates to a composition comprising at least one oxidation base chosen from 2-methoxymethyl-para-phenylenediamine of formula (I), one of its addition salts, its solvates and/or the solvates of its salts, at least one oxidation coupler, at least one compound chosen from etidronic acid, its salts and their mixtures and at least one compound chosen from 2,6-dipicolinic acid, its salts and their mixtures.The invention also relates to a method for dyeing keratin fibers, preferably the hair, comprising the application, to said keratin fibers, of the composition.