Cationic-Polymer Shampoo for Silicone Retention After Conditioner Rinsing

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Solution Overview

Problem

Silicone deposited on hair during shampooing is largely removed during subsequent conditioner washing, necessitating its inclusion in conditioner to provide conditioning benefits, which is inefficient.

Innovation Solution

A shampoo composition containing a pre-formed emulsified silicone, a cationic deposition polymer, and a hair substantive cationic conditioning polymer, such as an APTAC polymer, enhances silicone adhesion and retention on hair despite conditioner rinsing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If silicone is deposited on hair during shampooing, then conditioning benefits are provided, but the silicone is largely removed during subsequent conditioner washing

Engineering Contradiction:

Improvesilicone retention on hairVSAvoidsilicone loss during conditioner rinsing

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent introduces cationic polymers as intermediary substances that mediate between the silicone and the hair. These polymers have an affinity for both silicone and hair, forming a stable complex that prevents silicone from being removed during conditioner rinsing. The cationic polymers act as a bridge, holding the silicone onto the hair surface effectively.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite system combining silicone, cationic polymers, and hair. This composite formulation leverages the complementary properties of each component: silicone provides conditioning benefits, cationic polymers provide adhesion and retention, and hair is the substrate. The composite structure ensures silicone remains on hair even after conditioner application.

Inventive Principle:

Principle #40Composite materials

2Reliability

If silicone is included in conditioner to provide conditioning benefits, then conditioning effects are maintained, but the process becomes inefficient and complex

Engineering Contradiction:

Improveconditioning benefitsVSAvoidwashing process steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the silicone deposition function and conditioning function into a single shampoo formulation. By incorporating cationic polymers that enhance silicone retention, the shampoo alone can provide both cleansing and conditioning benefits, eliminating the need for separate conditioner application with silicone. This consolidation simplifies the overall hair care routine.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shampoo formulation is designed to perform multiple functions: cleansing, silicone deposition, and conditioning. The cationic polymers enable the shampoo to retain silicone effectively, making it a multi-functional product that replaces the need for separate conditioner treatment, thereby reducing process complexity while maintaining conditioning benefits.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Significantly higher silicone deposition and lower dry friction on hair are achieved, providing improved conditioning benefits without the need for additional conditioner silicone.

Implementation Method 1

a cationic deposition polymer which is a cationic polygalactomannan having a mean charge density at pH7 of from 0.2 to 2 meq per gram

Methodology Applied

Scientific EffectElectrostatic attraction: Electrostatics

Implementation Method 2

a hair substantive cationic conditioning polymer which is an APTAC polymer having a molecular weight of less than 1 million Daltons and a charge density at pH 7 of from 4 to 6

Methodology Applied

Scientific EffectElectrostatic interaction: Electrostatics

Implementation Method 3

a pre-formed emulsified silicone

Methodology Applied

Scientific EffectPhysical deposition: Deposition (physical)

Data Source

PatentEP3986370B1Personal cleansing compositions

Publication Date: 2025.10.29 UNILEVER GLOBAL IP LTD

AI summary

An aqueous shampoo composition comprising: - a. a pre-formed emulsified silicone; b. a cationic deposition polymer; c. a hair substantive cationic conditioning polymer which is an APTAC polymer, having a molecular weight of less than 1 million Daltons, preferably selected from a homopolymer of (3-acrylamidopropyl) trimethyl ammonium chloride and a (3-acrylamidopropyl) trimethyl ammonium chloride/acrylamide copolymer; d. from 3 to less than 12 wt %, preferably 5 to less than 10 wt %, based on total weight of the composition, of a cleansing surfactant, which has an average degree of ethoxylation of En, where n is a number that represents the average degree of ethoxylation and ranges from 0 to 3; e. a co-surfactantwhich is a betaine surfactant selected from an amido betaine amphoteric surfactant of general formula (II): (II) where m is 2 or 3; R1C(O) is selected from linear or branched, saturated or unsaturated acyl groups having from 8 to 22 carbon atoms and mixtures thereof; and R2 and R3 are each independently selected from alkyl, hydroxyalkyl or carboxyalkyl groups having from 1 to 6 carbon atoms and mixtures thereof; and an alkyl betaine of general formula (III): (III) wherein R is a coco chain, and mixtures thereof; and f. a suspending agent. in which the weight ratio of (d) to (e) ranges from 1:1 to 4.5:1 and the pH of the composition is from 3 to 6.5; results in superior deposition and retention of silicone on hair.