Aqueous Polyurethane Dispersion with Ketone-Hydrazide Azomethine Linkages
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Solution Overview
Problem
Existing aqueous polyurethane dispersions for coatings lack optimal film formation and final film properties, particularly in terms of hardness, scratch resistance, and chemical resistance, due to limitations in volatile organic compound (VOC) emission and the need for coalescing aids.
Innovation Solution
The development of an aqueous dispersion of polyurethane comprising ketone functional molecules derived from reacting C3-C20 ketones or aldehydes with epoxidized triglycerides or polyesters, combined with hydrazine functional moieties, which enhance liquid properties before film formation and final film properties through azomethine linkage formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional aqueous polyurethane dispersions are used to reduce VOC emissions, then VOC emission is reduced, but film hardness and scratch resistance deteriorate
Solution Approach 1:
The patent changes the chemical parameters of the polyurethane system by incorporating ketone functional molecules (derived from C3-C20 ketones or aldehydes reacting with epoxidized triglycerides or polyesters) and hydrazine functional moieties. This chemical parameter change enables the formation of azomethine linkages that enhance film hardness and scratch resistance while maintaining low VOC emissions through the aqueous dispersion formulation.
Solution Approach 2:
The patent creates a composite polyurethane system combining multiple functional components: polyurethane polymer, ketone functional molecules, and hydrazine functional moieties. This composite approach allows the material to simultaneously achieve low VOC emission and enhanced mechanical properties through the synergistic interaction of components, particularly the azomethine linkage formation between ketone and hydrazine groups.
2Object-generated harmful factors
If conventional aqueous polyurethane dispersions are used to reduce VOC emissions, then VOC emission is reduced, but scratch resistance deteriorates
Solution Approach 1:
The patent modifies the chemical composition parameters by introducing ketone functional molecules (from C3-C20 ketones or aldehydes reacting with epoxidized triglycerides or polyesters) and hydrazine functional moieties. This parameter change enables azomethine linkage formation that specifically enhances scratch resistance while maintaining the low VOC emission benefit of aqueous dispersion.
Solution Approach 2:
The patent develops a composite system combining polyurethane, ketone functional molecules, and hydrazine functional moieties. This composite structure creates enhanced scratch resistance through azomethine linkage formation while preserving the environmentally friendly low VOC emission characteristic of water-based formulations.
3Object-generated harmful factors
If conventional aqueous polyurethane dispersions are used to reduce VOC emissions, then VOC emission is reduced, but chemical resistance deteriorates
Solution Approach 1:
The patent changes the chemical composition by incorporating ketone functional molecules (derived from C3-C20 ketones or aldehydes reacting with epoxidized triglycerides or polyesters) and hydrazine functional moieties. This parameter change enables the formation of azomethine linkages that provide enhanced chemical resistance while maintaining low VOC emissions through the aqueous dispersion system.
Solution Approach 2:
The patent creates a composite polyurethane system with ketone functional molecules and hydrazine functional moieties that forms azomethine linkages. This composite structure enhances chemical resistance and durability while preserving the environmental benefit of low VOC emission through water-based formulation.
4Ease of manufacture
If coalescing aids are used to improve film formation, then film formation is improved, but VOC emission increases
Solution Approach 1:
The patent enables the polyurethane dispersion to self-form proper films through the inherent chemical reactivity of ketone and hydrazine functional groups forming azomethine linkages. This self-service mechanism eliminates the need for external coalescing aids that would increase VOC emissions, achieving effective film formation through the system's own chemical properties.
Solution Approach 2:
The patent changes the chemical parameters by incorporating ketone functional molecules (from C3-C20 ketones or aldehydes reacting with epoxidized triglycerides or polyesters) and hydrazine functional moieties. This parameter change enables the dispersion to self-coalesce and form films through azomethine linkage formation without requiring VOC-containing coalescing aids, thus improving film formation while reducing VOC emissions.
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 improves film hardness, scratch resistance, and chemical resistance while reducing VOC emissions and the need for coalescing aids, resulting in enhanced film integrity and performance.
Implementation Method 1
ketone functional molecules derived from reacting a C3-C20 ketone or aldehyde containing carboxylic acid with 1) an epoxidized triglyceride or 2) an epoxidized polyester... combined with hydrazine functional moieties, which enhance liquid properties before film formation and final film properties through azomethine linkage formation
Implementation Method 2
a ketone functional molecule derived from reacting a C3-C20 ketone or aldehyde containing carboxylic acid with 1) an epoxidized triglyceride or 2) an epoxidized polyester
Data Source
AI summary
An aqueous dispersion of polyurethane composites is made by forming a dispersion of urethane prepolymer or polymer and ketone functional molecular by dispersing them in an aqueous media and adding a hydrazine functional molecule. When the ketone functional molecule is derived from levulinic acid and epoxidized vegetable oil, the resulting urethane dispersion has enhanced coalescence with less need for coalescing aids.