Cationic Polyester Emulsion via Surfactant Adsorption

Solution Overview

Problem

Existing methods for producing cationic polyester emulsions are challenging due to the anionic nature of polyester carboxylic acid salts, which requires the introduction of polyalkylene glycol-derived structures to achieve stability, limiting design flexibility and performance in water abrasion resistance.

Innovation Solution

A method involving the production of an anionic polyester emulsion followed by addition to an aqueous solution of a cationic surfactant, allowing two surfactant molecules to adsorb onto the carboxylic acid salt, resulting in a stable cationic aqueous emulsion of polyester without the need for polyalkylene glycol-derived structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If polyalkylene glycol-derived structures are introduced into polyester to achieve stability, then stability is improved, but design flexibility and water abrasion resistance deteriorate

Engineering Contradiction:

Improveemulsion stabilityVSAvoiddesign flexibility

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The invention extracts and removes the polyalkylene glycol-derived structures from the polyester composition. By eliminating this specific component that caused the contradiction, the patent achieves both improved design flexibility and water abrasion resistance while maintaining emulsion stability through the alternative cationic surfactant system.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces cationic surfactant molecules as an intermediary mechanism to achieve emulsion stability without polyalkylene glycol-derived structures. The cationic surfactant mediates the stabilization process by interacting with the polyester particles, providing the necessary stability while allowing design flexibility and improved water abrasion resistance.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If polyalkylene glycol-derived structures are introduced into polyester to achieve stability, then stability is improved, but water abrasion resistance deteriorates

Engineering Contradiction:

Improveemulsion stabilityVSAvoidwater abrasion resistance

Core Design Contradiction:

Stability of the object's compositionVSStrength

Solution Approach 1:

The invention extracts and removes the polyalkylene glycol-derived structures from the polyester composition. By eliminating this specific component that caused the contradiction, the patent achieves both improved design flexibility and water abrasion resistance while maintaining emulsion stability through the alternative cationic surfactant system.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces cationic surfactant molecules as an intermediary mechanism to achieve emulsion stability without polyalkylene glycol-derived structures. The cationic surfactant mediates the stabilization process by interacting with the polyester particles, providing the necessary stability while allowing design flexibility and improved water abrasion resistance.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If conventional emulsification methods are used, then production process is simple, but glass transition temperature and water abrasion resistance are insufficient

Engineering Contradiction:

Improveproduction process simplicityVSAvoidglass transition temperature

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The invention changes the chemical parameters of the emulsion system by using cationic surfactants instead of conventional emulsifiers. This parameter change allows the production of polyester emulsions with higher glass transition temperatures and improved water abrasion resistance while maintaining a relatively simple two-step production process.

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

This approach enables the production of a cationic aqueous emulsion of polyester with improved glass transition temperature and water abrasion resistance, as well as enhanced fuel resistance for asphalt pavements.

Implementation Method 1

allowing two surfactant molecules to adsorb onto the carboxylic acid salt

Methodology Applied

Scientific EffectAdsorption: Adsorption

Data Source

PatentUS20250163272A1Method for producing an aqueous emulsion of polyester

Publication Date: 2025.05.22 KAO CORP

AI summary

The present invention provides: a method for producing an aqueous emulsion of a polyester, the method including adding an aqueous dispersion of a polyester to a soap solution of a cationic surfactant, the polyester in the aqueous dispersion having a negative value zeta potential; and an aqueous emulsion of a polyester, containing an a polyester and a cationic surfactant, particles containing the polyester having a positive value zeta potential and a volume average particle diameter of ≤300 nm.