Polyol Ether Additives for Porous Polyurethane Coatings
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Solution Overview
Problem
Current surfactants used in producing porous polyurethane coatings, such as ammonium stearate, face issues like water susceptibility, foam instability, and migration, leading to undesirable properties like flocculation, gelling, and surface defects, particularly in contact with lime-containing water, and require additional surfactants for stability.
Innovation Solution
The use of polyol ethers as additives in aqueous polymer dispersions for producing porous polymer coatings, which enables efficient foaming, stable foam formation, and improved hydrolysis stability, reducing the need for additional surfactants and enhancing mechanical and haptic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ammonium stearate is used as a surfactant in aqueous polymer dispersions, then foam formation is achieved, but the dispersion becomes susceptible to hard water, forming insoluble calcium soaps and exhibiting high migration
Solution Approach 1:
The patent changes the chemical parameters of the surfactant by using polyol ethers with specific molecular structures (containing polyoxyethylene chains and polyoxypropylene chains) that alter their interaction with hard water ions, eliminating calcium soap formation while maintaining foam formation capability
Solution Approach 2:
The patent replaces the migratory ammonium stearate with polyol ethers that remain stable in the dried film, eliminating the need for continuous migration and the associated surface defects, effectively treating the surfactant as a non-migratory additive
2Quantity of substance
If ammonium stearate is used to produce porous polyurethane coatings, then air permeability is achieved, but drying defects such as cell coarsening and drying cracks occur
Solution Approach 1:
The patent uses polyol ethers that provide feedback control during the drying process through their unique molecular structure, which prevents cell coarsening and drying cracks by maintaining appropriate surface tension and foam stability throughout the drying cycle
Solution Approach 2:
The patent changes the surfactant parameters to polyol ethers with specific HLB values and molecular weights that optimize foam stability during drying, preventing cell coarsening and drying defects while maintaining air permeability
3Reliability
If additional surfactants are added to achieve sufficient foam stability, then foam stability is improved, but the complexity of the formulation increases
Solution Approach 1:
The patent uses polyol ethers that perform multiple functions simultaneously: they act as surfactants for foam formation, provide water stability, prevent migration, and maintain foam stability during drying, eliminating the need for multiple separate surfactant components
Solution Approach 2:
The patent merges the functions of multiple surfactants into a single polyol ether component, combining foam formation, water stability, and foam stability maintenance in one additive, thereby reducing formulation complexity
Data Source
AI summary
The invention relates to the use of polyolethers as additives in aqueous polymer dispersions for producing porous polymer coatings, preferably for producing porous polyurethane coatings.