1,3-Thiazolyl Azo Dyes for Wetfast Blue Polyester Dyeing
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Solution Overview
Problem
Existing azo dyes lack excellent wetfastness and lightfastness, particularly for blue dyeings, which are essential for meeting market demands.
Innovation Solution
Development of disperse azo dyes comprising a 1,3-thiazolyl diazo component combined with a dialkoxycarbonylalkylaminophenol coupling component, specifically formulated to achieve excellent wetfastness and lightfastness, with the dyes being obtainable through known methods and optimized for use in hydrophobic materials like polyester fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing azo dyes are used, then the dyeing process is simple, but the wetfastness and lightfastness are insufficient
Solution Approach 1:
The patent applies composite materials by combining a 1,3-thiazolyl diazo component with a dialkoxycarbonylalkylaminophenol coupling component to create a disperse azo dye with composite molecular structure. This composite structure integrates the advantages of both components: the thiazolyl group provides excellent wetfastness while the coupling component ensures good lightfastness, resolving the contradiction between fastness improvement and structural complexity
Solution Approach 2:
The patent employs parameter changes by systematically varying the substituents R1-R4 on the phenol ring and the alkyl chains in the coupling component. By optimizing parameters such as the position and type of substituents (e.g., alkyl, alkoxy, halogen groups), the patent achieves excellent wetfastness and lightfastness while maintaining practical dyeing properties, thus improving reliability without excessive complexity
2Reliability
If dyes with excellent wetfastness are developed, then market demands are met, but the dyeing process complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the dye molecule into two independently synthesizable components: the 1,3-thiazolyl diazo component and the dialkoxycarbonylalkylaminophenol coupling component. Each component can be prepared separately using established synthetic routes, then coupled together in a final azo coupling reaction. This segmentation simplifies manufacturing by allowing modular synthesis and quality control of each functional unit
Solution Approach 2:
The patent uses the dialkoxycarbonylalkylaminophenol compound as an intermediary that bridges the diazo component and the final dye product. This intermediary compound is prepared in advance and then reacts with the diazo component under controlled conditions to form the final azo dye. The intermediary approach allows for optimized reaction conditions and easier purification, maintaining ease of manufacture while achieving excellent fastness properties
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 resulting dyes provide outstanding wash- and perspiration fastness, particularly in polyester-cotton blends, with low staining in high-temperature industrial laundering conditions, as demonstrated by the Hoechst combination test.
Implementation Method 1
The compounds of formula (IV) are generally diazotized in a known manner, for example with nitrosylsulfuric acid in dilute sulfuric acid, phosphoric acid or a mixture of acetic and propionic acids.
Implementation Method 2
The diazotized compounds are generally likewise coupled onto the compounds of formula (V) in a known manner, for example in an acidic, aqueous, aqueous-organic or organic medium
Data Source
AI summary
The present invention provides disperse dyes of formula I where R1 to R4, A and B are each as defined in claim 1, processes for their preparation and their use.