Sulfonic Acid Polyisocyanate Composition for Stable Water Dispersion
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Solution Overview
Problem
Aqueous two-liquid type urethane coating compositions face challenges in achieving excellent pot life, dispersibility, appearance, hardness, water resistance, and stain resistance due to issues with polyisocyanate compatibility and hydrophobicity, leading to turbidity and decreased film quality.
Innovation Solution
A polyisocyanate composition containing a sulfonic acid anion group and a tertiary ammonium cation of an amine compound, specifically aliphatic or alicyclic polyisocyanates, is developed to enhance dispersibility and film properties, with a tertiary ammonium cation content of 70 mol% or more, improving pot life and film characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If polyisocyanate is dispersed in water-based systems, then environmental compatibility is improved, but dispersibility and stability deteriorate due to carbon dioxide generation and poor compatibility
Solution Approach 1:
The patent introduces a sulfonic acid group as an intermediary component that mediates between the hydrophobic polyisocyanate and the hydrophilic water-based system. The sulfonic acid group provides hydrophilicity and ionic character, enabling stable dispersion of polyisocyanate in water without direct harmful reaction, thus resolving the contradiction between environmental compatibility and dispersibility.
Solution Approach 2:
The invention creates a composite polyisocyanate structure combining hydrophobic polyisocyanate segments with hydrophilic sulfonic acid groups. This composite approach allows the material to simultaneously achieve water-based compatibility (environmental friendliness) and stable dispersion (resistance to CO2 generation and phase separation).
2Stability of the object's composition
If sulfonic acid groups are added to improve dispersibility, then water compatibility is improved, but film hardness and appearance deteriorate due to poor compatibility and turbidity
Solution Approach 1:
The patent optimizes the parameter of sulfonic acid group content within a specific range (0.1-10 mmol/g) to balance water compatibility and film quality. By controlling this parameter, the invention achieves adequate hydrophilicity for dispersion while preventing excessive turbidity and maintaining film hardness and appearance.
Solution Approach 2:
The invention applies local quality by introducing sulfonic acid groups at specific locations on the polyisocyanate molecule rather than uniformly throughout. This localized modification provides sufficient hydrophilicity for water compatibility while preserving the bulk hydrophobic character needed for film hardness and appearance quality.
3Strength
If aminosulfonic acid with high hydrophobicity is used to improve film hardness, then coating hardness is improved, but water resistance and stain resistance deteriorate
Solution Approach 1:
The patent carefully controls the hydrophobicity parameter of the aminosulfonic acid component, selecting compounds with balanced properties rather than extreme hydrophobicity. This parameter optimization ensures sufficient film hardness while maintaining adequate water resistance and stain resistance by avoiding excessive hydrophobicity that would compromise these properties.
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 composition achieves excellent pot life and dispersibility in water-based systems, resulting in coating films with enhanced appearance, hardness, and water resistance.
Implementation Method 1
a polyisocyanate having a sulfonic acid anion and a tertiary ammonium cation of an amine compound
Data Source
AI summary
The present invention provides a polyisocyanate composition comprising a polyisocyanate having a sulfonic acid anion group in its molecule and a tertiary ammonium cation of an amine compound, wherein the tertiary ammonium cation of an amine compound includes a tertiary ammonium cation of at least one amine compound selected from amine compounds represented by the following general formulas (1) and (2), and an amount of the tertiary ammonium cation of the selected amine compound is 70 mol% or more with respect to a total molar amount of the tertiary ammonium cation of all amine compounds in the composition.