Water-Dispersible Polyurethane Thickener Salt Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current polyurethane thickeners for water-based preparations, such as cosmetics and paints, face issues with salt stability, viscosity changes, and compatibility with surfactants, leading to inconsistent performance and environmental concerns due to the use of tin-containing catalysts.
Innovation Solution
Development of water-dispersible polyurethanes with an essentially linear backbone composed of alternating hydrophilic and hydrophobic sections, using aliphatic diisocyanate radicals and polyether radicals, which are tin-free and form stable micelles in water, maintaining viscosity even in the presence of salt and surfactants, and are produced using zinc or titanium catalysts to minimize environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional polyurethane thickeners are used to increase viscosity, then thickening effect is achieved, but salt stability deteriorates leading to abrupt viscosity decrease
Solution Approach 1:
The polyurethane molecule is segmented into distinct hydrophilic sections (S and P) and hydrophobic sections (T and D) arranged in an alternating sequence. This segmentation allows the hydrophilic sections to interact with water and maintain solubility while the hydrophobic sections form association structures for thickening, and the specific sequence provides resistance to salt-induced precipitation.
Solution Approach 2:
The patent creates a composite molecular structure combining polyether radicals (hydrophilic) with aliphatic diisocyanate radicals (hydrophobic) in a specific alternating pattern. This composite structure at the molecular level provides both the thickening capability and salt stability that neither component could achieve alone.
2Force
If conventional polyurethane thickeners are used, then viscosity increase is achieved, but compatibility with surfactants and salts deteriorates
Solution Approach 1:
Different sections of the polyurethane molecule have different local qualities: hydrophilic sections (S and P) provide water compatibility and solubility, while hydrophobic sections (T and D) provide thickening through association. The specific alternating sequence ensures that both functionalities are maintained simultaneously, along with compatibility with surfactants and salts.
Solution Approach 2:
The patent changes the molecular parameters by specifying the alternating sequence of hydrophilic and hydrophobic sections with particular molecular weight ratios (S:P from 1:1.4 to 1:140). This parameter optimization enables the thickener to maintain compatibility with multiple auxiliaries including surfactants and salts while achieving effective thickening.
3Ease of manufacture
If tin-containing catalysts are used in production, then polyurethane synthesis is achieved, but environmental impact increases
Solution Approach 1:
The patent replaces expensive and environmentally problematic tin-containing catalysts with zinc or titanium catalysts that are less harmful to the environment. While tin catalysts may offer slightly better activity, the zinc/titanium alternatives provide sufficient catalytic function with reduced environmental impact, aligning with modern sustainable manufacturing requirements.
4Force
If known thickeners are used in cosmetic preparations, then viscosity increase is achieved, but texture and skin feel quality deteriorates
Solution Approach 1:
The patent optimizes molecular parameters including the molecular weight ratio of hydrophilic sections (S:P from 1:1.4 to 1:140), the alternating sequence pattern, and the specific composition of hydrophobic sections to achieve both adequate viscosity and excellent texture/skin feel properties required for cosmetic applications.
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 new polyurethanes provide stable and high viscosity in water-based preparations, are tolerant to high salt and surfactant concentrations, and are produced with reduced environmental impact, offering improved rheological properties and compatibility with cosmetic and industrial applications.
Implementation Method 1
water-dispersible polyurethane (PU) with an essentially linear backbone composed of alternating hydrophilic and hydrophobic sections
Implementation Method 2
form stable micelles in water
Implementation Method 3
the hydrophobic segments construct a viscosity-imparting three-dimensional molecular association via an association with one another
Data Source
AI summary
The present invention relates to novel polyurethanes and to mixtures of such polyurethanes, to processes for their preparation, to their use for producing preparations comprising water and to preparations which comprise the polyurethanes. In particular, the invention relates to water-dispersible polyurethane with an essentially linear backbone composed of alternating hydrophilic and hydrophobic sections.