Cyano-Halogen Azo Dye Composition for Fast Polyester Dyeing
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Solution Overview
Problem
Current azo dyes based on aminophthalimides do not meet modern requirements for light fastness and washing fastness, particularly in dyeing or printing of semi-synthetic and synthetic hydrophobic textile materials.
Innovation Solution
Development of azo dyes with specific halogen- and cyanosubstituted phthalimides, which exhibit excellent light fastness and washing fastness properties, achieved through a process involving a mixture of alkali metal cyanide and heavy metal cyanide in aprotic polar solvents, resulting in dyes with improved fastness properties without the need for separation of reaction products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional azo dyes based on aminophthalimides are used, then the dyeing process is simple, but the light fastness and washing fastness are insufficient
Solution Approach 1:
The patent applies parameter changes by substituting specific groups (halogen and cyano groups) on the phthalimide ring at positions 3 and 4, and by selecting specific coupling components with particular structural features. These chemical parameter changes in the dye molecule structure directly improve light fastness and washing fastness while maintaining manufacturing feasibility through established chemical synthesis routes
Solution Approach 2:
The patent creates composite dye molecules by combining halogen-substituted phthalimide structures with specific coupling components (such as naphthalene, pyrazolone, thiophene, thiazole, quinoline, or 6-hydroxypyridone series). This composite molecular structure integrates multiple functional groups that work together to achieve superior fastness properties while maintaining dyeing performance
2Reliability
If new azo dyes with improved fastness properties are developed, then light fastness and washing fastness improve, but the reaction process becomes more complex requiring specific solvent systems and product separation
Solution Approach 1:
The patent changes the reaction parameter by using aprotic polar solvents (such as DMF, DMSO, NMP, or their mixtures with water) instead of conventional protic solvents. This solvent system parameter change enables the reaction to proceed efficiently while allowing direct use of the reaction mixture without complex separation procedures, thus improving washing fastness without significantly increasing process complexity
Solution Approach 2:
The patent uses a phase transfer catalyst (such as tetrabutylammonium bromide or crown ethers) as an intermediary substance to facilitate the reaction between organic and inorganic reagents. This mediator enables the reaction to proceed under milder conditions with better selectivity, improving product fastness properties while simplifying the overall reaction process and reducing the need for complex purification steps
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 azo dyes provide high fibre-levelness and surface-levelness on polyester materials, with excellent light fastness, washing fastness, and resistance to rubbing, perspiration, and water, making them suitable for various textile applications.
Implementation Method 1
The halogen/cyano exchange of dibromo compounds which leads to the claimed dyes of formula (1) is likewise known per se
Data Source
AI summary
The present invention relates to azo dyes of formula (1), wherein R1 denotes C1-C12alkyl which is unsubstituted or substituted by one or more C1-C12alkoxy groups, hydroxyl groups, amino groups, cyano groups or halogen atoms and which may be interrupted one or more times by the radical —O—, —S—, —COO— or —OOC—: R4 is hydrogen or C1-C12alkyl; either R2 is cyano and R3 is halogen or R2 is halogen and R3 is cyano; and Ar represents a carbocyclic or heterocyclic aromatic radical, to the process for the preparation thereof, to mixtures containing said dyes and to the use thereof in dyeing or printing semi-synthetic and especially synthetic hydrophobic fiber materials, more especially textile materials.