Textile Finishing Extender Composition for Stable Aqueous Dispersions
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Solution Overview
Problem
Aqueous dispersions used for oil- and water-repellent finishing of fiber materials, particularly those containing perfluoroalkyl-containing polymers, often lack storage stability, which hampers their effectiveness and processing efficiency.
Innovation Solution
An aqueous dispersion comprising a composition prepared by reacting a fluorine-free polyfunctional isocyanate with a monohydric alcohol, followed by reaction with a ketone oxime to maintain free isocyanate groups, and then with a fluorine-free organic amine or polyhydric alcohol to eliminate isocyanate groups, ensuring stability and enabling the use of perfluoroalkyl-containing polymers for textile finishing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional extenders (derivatives of polyfunctional isocyanates blocked with ketone oximes) are used to enhance oil- and water-repellent properties, then the repellent effectiveness is improved, but the storage stability of aqueous dispersions deteriorates
Solution Approach 1:
The patent divides the extender composition into multiple sequential reaction stages: first reacting polyfunctional isocyanates with polyhydric alcohols to form intermediate compounds with free NCO groups, then reacting with hydroxyl-containing amines, and finally blocking with ketone oximes. This segmentation of the chemical synthesis process allows precise control over the molecular structure and reactivity, achieving both high repellent effectiveness and storage stability that cannot be obtained with conventional single-stage extenders.
Solution Approach 2:
The patent systematically varies critical parameters including the type and amount of polyhydric alcohol (1.0-5.0 equivalents relative to NCO groups), the selection of hydroxyl-containing amines, and the blocking agent ratio to optimize the balance between repellent performance and storage stability. By adjusting these compositional parameters, the invention achieves aqueous dispersions that maintain both high oil- and water-repellent properties and excellent storage stability.
2Quantity of substance
If the amount of costly RF-polymers is reduced by using extenders, then the cost-effectiveness is improved, but the storage stability of the dispersion deteriorates
Solution Approach 1:
The patent creates a composite extender system combining multiple chemical components: polyfunctional isocyanates, polyhydric alcohols, hydroxyl-containing amines, and ketone oximes. This composite material approach allows the extender to provide both the oil- and water-repellent enhancement function and the storage stability function that would otherwise require higher concentrations of expensive RF-polymers, thereby reducing the overall quantity of RF-polymer needed in the dispersion.
3Reliability
If aqueous dispersions contain both extenders and perfluoroalkyl-containing polymers, then the oil- and water-repellent finishing effectiveness is improved, but the storage stability deteriorates
Solution Approach 1:
The patent designs the extender composition to act as an intermediary that is compatible with both water and perfluoroalkyl-containing polymers. The multi-stage reaction products create a molecular structure that serves as a bridge between the aqueous phase and the hydrophobic RF-polymer phase, allowing the dispersion to maintain high finishing effectiveness while achieving storage stability that prevents phase separation or precipitation during storage.
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 described process results in aqueous dispersions with excellent storage stability, allowing for effective oil- and water-repellent finishing of textiles with enhanced processing benefits and quality, including a soft hand feel for the finished products.
Implementation Method 1
reacting a fluorine-free polyfunctional isocyanate with a fluorine-free monohydric alcohol
Implementation Method 2
reacting the product obtained in step a) with a ketone oxime in such proportions that there are still free isocyanate groups present
Implementation Method 3
reacting the product mixture obtained in step b) with a fluorine-free organic amine which comprises two or three hydroxyl groups or with a fluorine-free polyhydric alcohol in such proportions that the resultant product is free of isocyanate groups
Data Source
AI summary
The use is described of aqueous dispersions in combination with fluoropolymers for oil- and water-repellent finishing of fiber materials. These dispersions have a long shelf life and contain a composition which is preparable by reaction of polyfunctional isocyanates with a deficiency of comparatively long-chain monohydric alcohols, subsequent reaction with a deficiency of a ketone oxime and final reaction with polyhydric alcohols or amino alcohols.