Thiophene Azo Dyes for Laundry Hueing Stability
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Solution Overview
Problem
Current hueing agents for textiles fail to effectively counteract yellowing in cellulosic substrates over multiple treatment cycles and are not stable in wash environments containing bleaching agents, leading to undesirable discoloration and reduced fabric lifespan.
Innovation Solution
Thiophene azo dyes with a formally charged moiety, composed of a chromophore and polymeric component, that absorb light to neutralize yellowness and remain stable in bleaching agents, preventing undesirable blue discoloration and extending fabric life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current hueing agents are used to counteract yellowing in cellulosic substrates, then initial hueing effect is achieved, but they build up over multiple treatment cycles causing undesirable blue discoloration
Solution Approach 1:
The patent modifies the chemical structure of thiophene azo dyes by introducing a formally charged moiety, which fundamentally changes the deposition and removal characteristics of the dye. This parameter change in molecular structure enables the dye to provide effective hueing while preventing buildup and blue discoloration over multiple wash cycles.
2Illumination intensity
If hueing agents are applied to brighten textile substrates, then visual brightening is achieved, but they are not stable in wash environments containing bleaching agents
Solution Approach 1:
The introduction of a formally charged moiety to the thiophene azo dye structure enhances its chemical stability in bleaching environments. This structural modification allows the dye to maintain its hueing properties and resist degradation when exposed to bleaching agents, thereby preserving visual brightness over time.
3Quantity of substance
If conventional thiophene azo hueing agents are used, then deposition on fabrics is achieved, but removal and hue angle control are insufficient
Solution Approach 1:
The formally charged moiety in the modified thiophene azo dyes alters the interaction between the dye and fabric, improving deposition efficiency. Simultaneously, this structural change enhances the dye's responsiveness to processing conditions, allowing for better control of hue angle and removal characteristics.
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 thiophene azo dyes provide enhanced deposition, removal, and hue angle benefits, effectively neutralizing yellowness in textiles while maintaining stability in bleaching environments, thus extending the life of cellulosic substrates.
Implementation Method 1
Suitable chromophore components generally fluoresce blue, red, violet, or purple color when exposed to ultraviolet light, or they may absorb light to reflect these same shades
Implementation Method 2
Suitable chromophore components generally fluoresce blue, red, violet, or purple color when exposed to ultraviolet light
Data Source
AI summary
This application relates to thiophene azo dyes for use as hueing agents, laundry care compositions comprising such thiophene azo dyes, processes for making such thiophene azo dyes, and laundry care compositions and methods of using the same. The thiophene azo dyes contain a formally charged moiety and are generally comprised of at least two components: at least one chromophore component and at least one polymeric component. Suitable chromophore components generally fluoresce blue, red, violet, or purple color when exposed to ultraviolet light, or they may absorb light to reflect these same shades. These thiophene azo dyes are advantageous in providing a hueing effect, for example, a whitening effect to fabrics, while not building up over time and causing undesirable blue discoloration to the treated fabrics. The thiophene azo dyes are also generally stable to bleaching agents used in laundry care compositions.