Aqueous Polyurethane Acrylate Hybrid Dispersion Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polyurethane/acrylic hybrid systems face issues with film quality and phase separation, and struggle with adhesion to low-energy surfaces like polyolefins, often requiring costly and time-consuming procedures involving surfactants or organic solvents.
Innovation Solution
The development of waterborne polyurethane/acrylic hybrid dispersions without surfactants, achieved through the formation of core-shell hybrid particles with a mostly acrylate core and a cross-linked polyurethane shell, using anionic stabilizers and vinyl-functionalized polyols, and cross-linking monomers, which are incorporated into the polyurethane backbone during prepolymer formation, allowing for stable dispersions and improved adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If polyurethane and acrylic dispersions are blended, then the system combines chemical resistance and water/weathering resistance, but film quality deteriorates and phase separation occurs
Solution Approach 1:
The patent merges polyurethane and acrylic components into a single unified polymer structure through copolymerization, creating hybrid particles where the two polymers are chemically bonded rather than physically blended. This eliminates the phase separation issue while maintaining the advantageous properties of both components.
Solution Approach 2:
The invention creates composite hybrid particles comprising both polyurethane and acrylic segments within a single particle structure. This composite approach allows the material to exhibit both the chemical resistance of polyurethane and the water/weathering resistance of acrylics without the defects of simple blending.
2Reliability
If polar polymers are used for adhesion, then chemical resistance and film formation are improved, but adhesion to low energy surfaces like polyolefins deteriorates
Solution Approach 1:
The patent introduces non-polar segments specifically at the surface region of the hybrid particles, creating a localized non-polar outer layer that enhances adhesion to low energy surfaces like polyolefins, while the internal structure maintains the polar polyurethane/acrylic components for chemical resistance and film formation.
Solution Approach 2:
The hybrid particles comprise a composite structure with non-polar segments integrated into the particle morphology, creating a dual-nature material that simultaneously exhibits polarity for chemical resistance and non-polarity for adhesion to polyolefin surfaces.
3Strength
If surfactants are used to achieve stable dispersions, then adhesion is improved, but environmental friendliness and cost-efficiency deteriorate
Solution Approach 1:
The patent employs anionic stabilizers that are incorporated into the polyurethane chain structure itself, enabling the system to stabilize the dispersion autonomously without requiring external surfactants. The stabilizer groups within the polymer chains provide the necessary electrostatic repulsion to prevent aggregation, eliminating the need for separate surfactant additives.
Solution Approach 2:
The invention extracts and eliminates the need for surfactants by incorporating stabilizing functionality directly into the polyurethane polymer structure through anionic stabilizer groups, thereby removing the harmful environmental impact and cost associated with surfactant additives.
4Ease of manufacture
If high acrylic contents are incorporated, then cost-efficiency is improved, but film quality and phase separation resistance deteriorate
Solution Approach 1:
The patent creates composite hybrid particles with a defined structure where polyurethane and acrylic segments are chemically bonded together. This composite structure allows high acrylic content (up to 90 wt.%) to be incorporated while maintaining film quality, as the covalent bonding between polymer segments prevents phase separation even at high acrylic concentrations.
Solution Approach 2:
The invention changes the fundamental parameter of polymer compatibility from physical mixing to chemical bonding through copolymerization. This parameter change enables the system to tolerate high acrylic contents without phase separation, as the chemical bonds maintain structural integrity even when one component is present in excess.
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 results in high-quality, stable dispersions with enhanced adhesion to low-energy surfaces, eliminating the need for surfactants and organic solvents, while maintaining environmental friendliness and cost-efficiency.
Implementation Method 1
polymerizing the vinyl groups of the prepolymer and the at least one acrylic monomer to obtain the polyurethane acrylate hybrid polymer dispersion
Implementation Method 2
incorporating anionic stabilizers into the polyurethane chain, not affecting the water resistance of the final product
Implementation Method 3
cross-linked polyurethane shell, using anionic stabilizers and vinyl-functionalized polyols, and cross-linking monomers
Data Source
AI summary
The present invention relates to processes for the manufacture of aqueous polyurethane/acrylic hybrid dispersions that can be used as adhesives or coatings, are solvent free and have low VOC emissions, and are environmentally friendly. Also encompassed are the dispersions as such, compositions containing them and their use as coatings and adhesives.