Alkali-Soluble Polymer Emulsions for Non-Sticky Moisturization

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Solution Overview

Problem

Oil-in-water emulsified cosmetics face challenges in achieving a watery light sensation without stickiness while maintaining long-lasting moisturizing effects, as existing formulations with synthetic water-soluble polymers and polysaccharides often result in a heavier, stickier texture.

Innovation Solution

An oil-in-water emulsified cosmetic comprising an aqueous medium, an alkali-soluble polymer with a carboxy group and amphiphilic side chain, a nonionic surfactant with a specific HLB, and a combination of liquid and paste oils, where the mass ratio of paste oil to liquid oil is greater than 0 and no greater than 1, without silicone-based oils, forming an associated complex to enhance emulsifying ability and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If synthetic water-soluble polymers and polysaccharides are added to the aqueous component to provide moisturizing effect, then the moisturizing effect is improved, but the texture becomes heavier and stickier

Engineering Contradiction:
Improvemoisturizing effect durationVSAvoidstickiness
Core Design Contradiction:
Duration of action of moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical parameters of the polymer by introducing a specific structure with carboxy groups and amphiphilic side chains (hydrophobic blocks and hydrophilic blocks). This structural modification allows the polymer to interact differently with water and oil components, achieving moisturizing effects without the stickiness associated with conventional water-soluble polymers. The specific parameter changes include the polymer's ability to form associated complexes with surfactants while maintaining water solubility under neutral to alkaline conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite system combining the alkali-soluble polymer with specific nonionic surfactants (having HLB of 6-12.0) and oil components (liquid oil and paste oil in specific ratios). This composite formulation allows the polymer to work synergistically with other ingredients, where the surfactant complex formation enhances emulsifying ability while the oil components provide moisturizing effects without excessive stickiness. The composite approach enables achieving multiple functions simultaneously.

Inventive Principle:
Principle #40Composite materials

2Reliability

If alkali-soluble polymer with amphiphilic side chain is used to improve water solubility and emulsifying ability, then the emulsifying ability is improved, but the formulation complexity increases

Engineering Contradiction:
Improveemulsifying abilityVSAvoidformulation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The alkali-soluble polymer with amphiphilic side chains serves multiple functions simultaneously: it acts as a water-soluble thickener, an emulsifier, and a moisturizing agent. The polymer's carboxy groups provide water solubility under neutral to alkaline conditions, while the amphiphilic side chains (with hydrophobic blocks and hydrophilic blocks) enable it to interact with both aqueous and oil phases. This multi-functionality reduces the need for separate additives, thereby managing formulation complexity while improving emulsifying ability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The alkali-soluble polymer acts as an intermediary between the aqueous phase and oil phase, facilitating stable emulsion formation. The polymer's amphiphilic structure allows it to bridge water and oil components, forming associated complexes with nonionic surfactants that enhance emulsifying ability. This intermediary role enables stable oil-in-water emulsions without requiring excessive amounts of traditional emulsifiers, simplifying the overall formulation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Duration of action of moving object

If oil components are added to provide moisturizing effect, then the moisturizing effect is improved, but the texture becomes heavier

Engineering Contradiction:
Improvemoisturizing effect durationVSAvoidheaviness
Core Design Contradiction:
Duration of action of moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent modifies the physical parameters of oil incorporation by using a specific combination of liquid oil and paste oil in controlled ratios (mass ratio of paste oil to liquid oil greater than 0 and no greater than 1). The amphiphilic polymer and nonionic surfactant system enables stable emulsion of these oil components while maintaining a light texture. The parameter control ensures that oil is effectively incorporated for moisturizing without creating a heavy sensation on skin.

Inventive Principle:
Principle #35Parameter changes

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 cosmetic achieves a satisfactory feel with freshness and no stickiness, while providing a long-lasting moisturizing effect and stable emulsified state, meeting consumer demands for both moisturization and light sensation.

Implementation Method 1

component (B) also has a hydrophobic block at the side chain end, and therefore its hydrophobic portions associate with the hydrophobic groups of the nonionic surfactant (C3-C6 straight-chain or cyclic polyol residues), to form an associated complex in component (A)

Methodology Applied
Scientific EffectAssociated complex formation:

Implementation Method 2

its hydrophobic portions associate with the hydrophobic groups of the nonionic surfactant

Methodology Applied
Scientific EffectHydrophobic interaction:

Implementation Method 3

component (B), which has a hydrophilic block on a side chain and also includes a carboxy group, facilitates swelling, dispersion or dissolution in water

Methodology Applied
Scientific EffectSwelling:

Implementation Method 4

facilitates swelling, dispersion or dissolution in water

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 5

a nonionic surfactant having at least one C3-6 straight-chain or cyclic polyol residue and an HLB of 6-12.0

Methodology Applied
Scientific EffectSurfactant action: Surfactant

Implementation Method 6

An oil-in-water emulsified cosmetic comprising (A) an aqueous medium, (B) an alkali-soluble polymer... (D) a liquid oil and (E) a paste oil

Methodology Applied
Scientific EffectEmulsion: Emulsion

Data Source

PatentUS12109281B2Oil-in-water emulsified cosmetic
Publication Date: 2024.10.08 LVMH RECH

AI summary

An oil-in-water emulsified cosmetic comprising an aqueous medium, an alkali-soluble polymer having a carboxy group and an amphiphilic side chain comprising a hydrophobic block and a hydrophilic block and bonded to the main chain at the hydrophilic block end, a nonionic surfactant having a C3-C6 straight-chain or cyclic polyol residue and an HLB of (6.0-12.0), a liquid oil and a paste oil.