Laundry Shading Composition for Polycotton Whiteness Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current dye deposition technologies for polyester-cotton blends are inefficient, with acid azine dyes failing to deposit effectively on polyester garments and causing over-deposition on cotton garments, leading to unacceptably large blueing and poor whiteness maintenance.
Innovation Solution
The use of selected cationic azine dyes that are substantive to both cotton and polyester fabrics, providing stable whiteness improvement with minimal dulling and no build-up, incorporated into a laundry treatment composition with surfactants and optional fluorescent agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If acid azine dyes are used as shading agents, then deposition on cotton is achieved and overblueing is prevented, but deposition on polyester-cotton blended garments is poor
Solution Approach 1:
The patent inverts the charge of the dye from anionic (acid azine) to cationic (basic azine). This charge reversal enables the dye to interact with polyester-cotton blends through different mechanisms, achieving substantial deposition on both cotton and polyester components while maintaining control over deposition quantity through the specified concentration range of 0.0001 to 0.1 wt %.
2Quantity of substance
If cationic azine dyes are used to improve deposition on polycotton, then whiteness improvement is achieved, but there is risk of excessive deposition on cotton garments
Solution Approach 1:
The patent optimizes the dye concentration parameter to a specific range of 0.0001 to 0.1 wt %, which balances deposition on both cotton and polycotton garments. This parameter control prevents excessive deposition on cotton while ensuring adequate deposition on polycotton, achieving the desired whiteness improvement without unacceptably large blueing on cotton garments.
3Illumination intensity
If dyes are used to counter-act yellowing and greying, then whiteness is improved, but fabric dulling may occur
Solution Approach 1:
The patent employs cationic azine dyes that provide a blue or violet hue to counter-act yellowing and greying of fabrics. The specific color selection and concentration control (0.0001 to 0.1 wt %) achieve effective whiteness improvement while minimizing fabric dulling, as the subtle blue/violet tint neutralizes yellow discoloration without creating an overly blue or dull appearance.
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 cationic azine dyes achieve effective deposition on polyester-cotton blends with minimal impact on cotton, maintaining whiteness and preventing build-up, while providing a blue or violet hue with improved stability and efficiency.
Implementation Method 1
Selected cationic azine dyes have a high substantivity to polycotton whilst depositing well on cotton
Implementation Method 2
from 0.005 to 2 wt % of a fluorescer
Data Source
AI summary
The present invention provides a laundry treatment composition comprising a cationic azine dye.