Reactive Polyamide Dyes for Wet-Fast Deep Black Dyeing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current reactive dyes fail to provide high substantivity, ease of washing off unfixed dye, good colour yield, and high reactivity, especially when used for dyeing synthetic polyamide fibre materials, resulting in inadequate fastness properties to light and wetting.
Innovation Solution
Development of novel reactive dyes with specific chemical structures, including a fibre-reactive radical and a chromium, cobalt, or iron complex, which are prepared through a multi-step condensation process, enhancing their substantivity and fibre-dye binding stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If acid dyes are used to achieve deep black dyeings on polyamide, then colour depth is improved, but fastness to wetting at elevated temperatures deteriorates
Solution Approach 1:
The invention changes the chemical nature of the dye from acid dye to reactive dye with specific molecular structure (formula I), containing fibre-reactive groups that form covalent bonds with polyamide. This parameter change enables deep black dyeings while achieving permanent fastness to wetting at elevated temperatures, resolving the contradiction between colour depth and wetting fastness.
2Reliability
If reactive dyes are used to achieve deep dyeings with good fastness to wetting, then fastness properties are improved, but substantivity and ease of washing off unfixed dye deteriorate
Solution Approach 1:
The invention introduces different functional groups with localized functions: hydrophilic groups (sulfo, carboxy, hydroxymethyl) at specific positions on the dye molecule enhance water solubility and ease of washing off unfixed dye, while the fibre-reactive groups (formula T) provide strong covalent bonding for fastness to wetting. This local differentiation of functional groups resolves the contradiction between fastness and ease of washing off.
3Reliability
If reactive dyes are used to achieve high fixing yields, then fibre-dye binding stability is improved, but reactivity and colour yield deteriorate
Solution Approach 1:
The invention creates a composite molecular structure (formula I) combining multiple functional components: chromophoric groups for colour, fibre-reactive groups (formula T) for covalent bonding and high fixing yields, and hydrophilic groups for solubility. This composite structure enables simultaneous achievement of high fibre-dye binding stability and good colour yield by optimizing the协同 effect of different functional groups.
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 novel reactive dyes achieve high fixing yields and excellent all-round fastness properties, including resistance to light and wetting, with improved reactivity and colour build-up, suitable for synthetic polyamide fibre materials.
Implementation Method 1
T is a fibre-reactive radical of formula (2c)-(2f) wherein the radical T reacts with amino groups of the fibre material to form covalent bonds
Implementation Method 2
Me is chromium, cobalt or iron, indicating the presence of metal coordination complexes in the dye structure
Data Source
AI summary
Reactive dyes of formula (1), wherein R1 is hydrogen or unsubstituted or substituted C1-C4alkyl, (R2)s denotes s identical or different substituents from the group halogen, nitro, unsubstituted or halo-substituted C1-C4alkyl, C2-C4alkanoylamino, C1-C4alkylsulfonyl, carbamoyl, sulfamoyl and sulfo, Me is chromium, cobalt or iron, X is chlorine, T is a fiber-reactive radical of formula —NH—(CH2)2-3—SO2—Z (2a), —NH—(CH2)2-3—O—(CH2)2-3—SO2—Z (2b), formula (2c), formula (2d), formula (2e), formula (2f), (R3)0-2 denotes from 0 to 2 identical or different substituents from the group halogen, C1-C4alkyl, C1-C4alkoxy and sulfo, Z is vinyl or a —CH2—CH2—U radical and U is a group that is removable under alkaline conditions, Q is a —CH(HaI)—CH2—HaI or —C(HaI)═CH2 group, Hal is halogen, s is the number 0, 1, 2 or 3 and m, n, r and q are each independently of the others the number 0 or 1, are especially suitable for dyeing synthetic polyamide fiber materials and yield dyeings or prints having good wet-fastness properties.