Crosslinked Polyurethane Inkjet Inks for Textile Washfastness
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Solution Overview
Problem
Inkjet printed fabrics with pigmented inks suffer from poor durability due to susceptibility to color removal by abrasion and inadequate washfastness, leading to fading and color transfer during washing.
Innovation Solution
The use of crosslinked polyurethane dispersoid binders in aqueous inkjet inks, with a weight ratio of at least 1.0 to colorant, improves durability and washfastness by incorporating a crosslinked polyurethane dispersoid with the inkjet ink composition, which includes a colorant soluble or dispersible in the aqueous vehicle, and optionally other additives for desired properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pigmented inkjet inks are used for textile printing, then water-fastness and light-fastness of printed images are improved, but durability and washfastness deteriorate due to color removal by abrasion and fading during washing
Solution Approach 1:
The patent introduces a crosslinking agent as an intermediary substance that mediates between the pigment particles and the textile substrate. The crosslinking agent forms covalent bonds with both the pigment and the textile fibers, creating a strong intermediary connection that prevents color removal during washing and abrasion, thereby resolving the contradiction between water-fastness and durability
Solution Approach 2:
The patent creates a composite material system consisting of pigment particles, crosslinking agent, and textile substrate. This composite structure integrates multiple components with different functions: the pigment provides color, the crosslinking agent provides bonding strength, and the textile provides the base material. The synergistic interaction of these components resolves the contradiction by combining the water-fastness properties of pigments with the durability properties of the crosslinked composite structure
2Stability of the object's composition
If conventional dispersing agents are used to stabilize pigments in aqueous media, then dispersion stability is improved, but washfastness and durability deteriorate
Solution Approach 1:
The patent changes the chemical parameter of the dispersing mechanism from physical adsorption (conventional dispersing agents) to chemical bonding (crosslinking). By using a crosslinking agent that forms covalent bonds, the patent transforms the interaction strength from weak physical forces to strong chemical bonds, thereby improving washfastness while maintaining dispersion stability
Solution Approach 2:
The crosslinking agent serves as a dual-function intermediary: it stabilizes pigment dispersion in aqueous media through its dispersing properties, and simultaneously provides strong covalent bonding to the textile substrate through crosslinking. This dual-function intermediary resolves the contradiction by combining dispersion stability with washfastness in a single substance
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 crosslinked polyurethane dispersoid binder enhances the washfastness and stain resistance of inkjet printed textiles to commercially acceptable levels, ensuring durability and preventing color transfer during laundering.
Implementation Method 1
pigments are stabilized by dispersing agents, such as polymeric dispersants or surfactants, to produce a stable dispersion of the pigment in the vehicle
Implementation Method 2
good fixation to media
Data Source
AI summary
Inkjet inks are described that have, as a principal component, a crosslinked polyurethane dispersoid binder additive. These inks can be used for printing on different media, and are particularly suitable for printing on textiles.