Crosslinked Polyurethane Ink Binders for Washfast Textile Printing
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Solution Overview
Problem
Inkjet printing with pigmented inks on textiles faces challenges such as poor durability due to color removal by abrasion and inadequate washfastness, with printed colors fading during washing and potentially transferring to other fabrics or washing machine parts, necessitating improved ink stability and durability.
Innovation Solution
The use of crosslinked polyurethane dispersoid binders in aqueous inkjet inks, specifically formulated with diols Z1, Z2, and Z3, or their physical mixtures, which provide enhanced washfastness and storage stability by incorporating a mixture of diols Z1, Z2, and Z3, and using a combination of crosslinked polyurethane dispersoids to improve the durability of inkjet printed textiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pigmented inkjet inks are used for textile printing, then the printing process can be performed, but the printed fabrics exhibit poor durability and washfastness with color removal by abrasion and fading during washing
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition of the binder system. Specifically, it uses crosslinked polyurethane dispersoids with controlled crosslink density (1-50 wt% as measured by THF insolubles) and specific diol combinations (Z1, Z2, and Z3 with defined molecular weight ranges and structural characteristics) to enhance the chemical resistance and adhesion properties of the ink formulation, thereby improving durability and reducing color removal during abrasion and washing
Solution Approach 2:
The patent employs composite materials by combining multiple crosslinked polyurethane dispersoids with different diol compositions (Z1, Z2, and Z3) to create a synergistic binder system. This composite approach allows the ink to achieve both flexibility and strength, with the different polyurethane components providing complementary properties that collectively improve washfastness and resistance to color removal while maintaining print durability
2Duration of action of stationary object
If extended storage of inkjet inks is required, then the inks must withstand storage conditions, but conventional inks may degrade in ink properties and print quality over time
Solution Approach 1:
The patent applies parameter changes by optimizing the chemical structure and crosslinking density of the polyurethane dispersoids. The controlled crosslinking (1-50 wt% THF insolubles) and specific diol compositions create a chemically stable binder system that resists degradation during extended storage, maintaining consistent ink properties and print quality over time without precipitation, gelation, or performance deterioration
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 solution significantly enhances the washfastness and durability of inkjet printed textiles, achieving commercially acceptable levels of stability and resistance to washing, as evidenced by improved ratings in washfastness and crock tests, while maintaining storage stability over extended periods.
Implementation Method 1
aqueous dispersions, preferably colorant dispersions, which further contain dispersed crosslinked polyurethane dispersoid particles
Implementation Method 2
These binders also have improved hydrolytic stability and consequently inks utilizing these binders have improved storage stability
Implementation Method 3
inkjet printed fabrics are particularly susceptible to color removal by abrasion and thus have poor durability
Data Source
AI summary
Inkjet inks that have, as a principal component, a crosslinked polyurethane dispersoid binder additive with selected diols used to prepare the polyurethane. The diols include a polyether diol, an ionic diol and polycarbonate, polyamide and/or poly(meth)acrylate diols. These inks can be used for printing on different media, and are particularly suitable for printing on textiles. The printed textiles are particularly durable to wash fastness and crock.