Disperse Azo Dye Mixtures for Polyester Wash Fastness
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Solution Overview
Problem
Existing mixtures of disperse phenylazo dyes with disperse pyridoneazo dyes do not provide optimal wash and contact fastness properties, especially on polyester and polyester-elastane materials, and do not achieve effective color buildup.
Innovation Solution
A dye mixture comprising specific disperse dyes of formulas (I) and (II), where R1 and R2 are (C1-C4)-alkyl or (C1-C4)-alkoxy-(C1-C4)-alkyl, and X is chloro or bromo, with preferred ratios of 30% to 45% and 55% to 70% by weight, respectively, which are mechanically mixed and finely subdivided for optimal dispersion and application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing mixtures of disperse phenylazo dyes with disperse pyridoneazo dyes are used, then dyeing of hydrophobic materials can be achieved, but wash and contact fastness properties are insufficient
Solution Approach 1:
The patent modifies the chemical structure of the disperse phenylazo dye by introducing specific substituents (R1, R2, R3 groups) and halogen atoms (chloro or bromo) at defined positions. These parameter changes in molecular structure enhance the dye's affinity and bonding with polyester and polyester-elastane fibers, resulting in improved wash and contact fastness while maintaining effective color buildup.
Solution Approach 2:
The invention creates a composite dye system by formulating specific mixtures of modified disperse phenylazo dyes (formula I) with disperse pyridoneazo dyes (formula II) in optimized weight ratios. This composite approach combines the complementary properties of both dye types to achieve superior fastness properties and color buildup that neither dye alone can provide on hydrophobic materials.
2Quantity of substance
If conventional dye mixtures are used, then basic dyeing can be performed, but color buildup properties are insufficient
Solution Approach 1:
The patent optimizes the weight ratio parameters of the dye mixture components, specifically formulating mixtures where disperse phenylazo dye (formula I) ranges from 30-70% and disperse pyridoneazo dye (formula II) ranges from 30-70%, with preferred ratios enhancing both color buildup and fastness. This parameter optimization ensures adequate color strength while maintaining service fastness.
3Ease of manufacture
If dye mixtures are mechanically mixed without fine subdivision, then preparation is simple, but dispersion and application performance are poor
Solution Approach 1:
The patent incorporates a preliminary subdivision step where the mechanically mixed dye particles are ground to a fine state before use. This preliminary action of size reduction ensures optimal dispersion quality and uniform application on the fabric, while the overall process remains relatively simple and can be performed using conventional milling equipment.
Data Source
AI summary
The present invention relates to dye mixtures which comprise at least one dye of the formula (I) and at least one dye of the formula (II) in which R1, R2, R3, and X are defined as stated in claim 1, to processes for their preparation, and to their use.