Textile Auxiliary Composition for Uniform PA/EL Dark Dyeing
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Solution Overview
Problem
The dyeing of polyamide/elastane blends often results in shade differences between the two fiber types, particularly when dark shades are applied, and existing shade enhancers deteriorate fastness properties and cause precipitation.
Innovation Solution
A textile auxiliary composition comprising an amphoteric betaine, a cationic quaternary ammonium salt, and an alkoxylated fatty alcohol is used, which enhances shade depth without compromising wet fastness, comprising cocoamidopropyl betaine, dodecyl dimethyl benzyl ammonium chloride, and ethoxylated oleyl alcohol, applied in an aqueous solution with a neutral to slightly acidic pH.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If quaternary ammonium salts are used to enhance shade depth on elastane, then coloration uniformity is improved, but wet fastness deteriorates
Solution Approach 1:
The patent uses a composite auxiliary system containing quaternary ammonium salt (for shade enhancement on elastane), betaine (as buffering agent and surfactant), and non-ionic surfactant (for wetting and leveling). This composite approach allows the quaternary ammonium salt to enhance elastane coloration while the other components mitigate its harmful effects on wet fastness through synergistic interactions.
Solution Approach 2:
The betaine and non-ionic surfactant act as intermediaries that modify the interaction between the quaternary ammonium salt and the dye liquor. The betaine buffers the system and the non-ionic surfactant provides additional wetting, allowing the quaternary ammonium salt to function without causing severe fastness deterioration.
2Manufacturing precision
If shade enhancing agents are added to the dye liquor, then shade depth is improved, but precipitation occurs
Solution Approach 1:
The non-ionic surfactant acts as an intermediary that prevents precipitation by adsorbing at the interface between dye particles and the liquor. The betaine also contributes to stabilization through its amphoteric nature, buffering the system and preventing aggressive interactions that would lead to precipitation.
Solution Approach 2:
The patent modifies the chemical environment of the dye liquor by introducing components with specific pH buffering capacity (betaine) and surfactant properties. These parameter changes create a more stable chemical environment that prevents precipitation while allowing shade enhancement to occur.
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 solution achieves on-tone coloration of polyamide/elastane blends with improved fastness properties, particularly wet fastness, and prevents dye particle precipitation, allowing for deep, intense dye buildup without loss of color stability or fastness during processing and wear.
Implementation Method 1
a textile auxiliary containing an amphoteric, a cationic and a non-ionic surfactant
Implementation Method 2
application of auxiliaries, like some specific quaternary ammonium salts, which enhance the shade depth on the elastane part
Implementation Method 3
addition of such shade enhancing agents to the dye liquor usually gives rise to a certain degree of precipitation
Data Source
AI summary
A composition comprising(a) a betaine of formulawherein R1 is a monovalent radical of an aliphatic C4-C30-hydrocarbon,R2 and R3 independently of one another represent C1-C12alkyl andX and Y independently of one another denote a bivalent radical of an aliphatic C1-C12-hydrocarbon,(b) a quaternary ammonium salt of formula (2)wherein R4 is a monovalent radical of an aliphatic C4-C30-hydrocarbon,R5, R6 and R7 independently of one another represent C1-C12alkyl, C5-C24aryl or C6-C30aralkyl,A− is halogenide, nitrate, hydrogensulfate or sulfonate, and(c) an alkoxylated fatty alcohol,is suitable as shade enhancer for the EL portion in PA/EL blends in the dyeing process using dark shade dyes.