Amide-Based Hair Relaxing Composition with Controlled pH and Heat

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Solution Overview

Problem

Existing hair relaxing methods using reducing agents or hydroxides are aggressive to hair and scalp, causing damage, odor issues, and poor durability of reshaping effects.

Innovation Solution

A process involving the application of a hair-relaxing composition containing cyclic or linear amides at a pH less than or equal to 9, combined with heating to a temperature between 110° C and 250° C, to relax keratin fibers without using reducing agents or hydroxides.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If reducing agents (thiols, sulfites, or bisulfites) are used to open disulfide bonds, then the hair can be reshaped, but the method causes unpleasant odors, fiber degradation, and poor stability of the reshaping effect

Engineering Contradiction:

Improvedurability of reshaping effectVSAvoidodor and fiber degradation

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent removes reducing agents (thiols, sulfites, bisulfites) from the hair relaxing composition entirely, extracting the harmful component while maintaining the core function of disulfide bond opening through alternative means (heat and amine compounds)

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the chemical parameters of the relaxing composition by replacing reducing agents with amine compounds at controlled pH levels (7.0-9.5), and changes physical parameters by applying heat (100-250°C) to achieve bond opening without the harmful chemical reactions of traditional reducing agents

Inventive Principle:

Principle #35Parameter changes

2Reliability

If hydroxides (sodium hydroxide, guanidinium hydroxide) are used for lanthionization, then the reshaping effect is durable and no fixing step is needed, but the method causes severe scalp irritation and hair damage

Engineering Contradiction:

Improvedurability of reshaping effectVSAvoidscalp irritation and hair damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts hydroxide bases from the composition, removing the cause of severe scalp irritation and hair damage while preserving the lanthionization mechanism through the use of amine compounds that can perform similar chemical transformations without the caustic effects

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces amine compounds as intermediary substances that mediate the chemical transformation of disulfide bonds to lanthionine bonds, achieving the desired reshaping effect without the direct contact of harsh hydroxides with the scalp and hair structure

Inventive Principle:

Principle #24Intermediary (Mediator)

3Shape

If high concentrations of thioglycolic acid (pH 8.5-9.5) are used for permanent waving, then satisfactory curling intensity is achieved, but the method causes fiber degradation and impairs artificial colorations

Engineering Contradiction:

Improvecurling intensityVSAvoidfiber integrity and coloration stability

Core Design Contradiction:

ShapeVSStrength

Solution Approach 1:

The patent adjusts the pH parameter to a lower range (7.0-9.5 compared to 8.5-9.5) and replaces thioglycolic acid with amine compounds, changing the chemical mechanism while maintaining the ability to achieve satisfactory curling intensity without fiber degradation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention substitutes the chemical mechanism of thioglycolic acid reduction with an alternative chemical system based on amine compounds and heat, replacing the harmful chemical action with a less aggressive mechanism that achieves the same shaping result

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This method effectively relaxes hair with improved cosmetic properties and fiber integrity, reducing damage and odor while maintaining durability of reshaping effects.

Implementation Method 1

a step of raising the temperature of the keratin fibres, using a heating means, to a temperature of between 110° C and 250° C.

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

applying to the keratin fibres a hair-relaxing composition containing at least one cyclic or linear amide, the pH of this composition being less than or equal to 9

Methodology Applied

Scientific EffectChemical interaction:

Data Source

PatentUS10092490B2Method for straightening keratinous fibres using heating means and an amide

Publication Date: 2018.10.09 LOREAL SA

AI summary

The invention concerns a method for straightening keratinous fibers including: (i) a step of applying on the keratinous fibers a hair straightening composition containing at least one cyclic or linear amide, (ii) a step of increasing the temperature of the keratinous fibers, using heating means, to a temperature ranging between 110 and 250° C.