Crosslinking Pigment Inkjet Ink for Soft, Wash-Fast Fabrics
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Solution Overview
Problem
Conventional inkjet printing methods using pigments face challenges with long-term storage stability, jetting stability, nozzle clogging, and the quality of colored fabric texture and fastness, particularly when compared to dye-based methods.
Innovation Solution
A pigment dispersion with a mean particle diameter of 200 nm or less, using a water-soluble pigment dispersant and a hydrophilic solvent, combined with a water-soluble fixing agent and a crosslinking agent, which undergoes a crosslinking reaction at 100° C or more to achieve stable jetting and excellent fastness on fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large amount of emulsion resin is used for fixing pigments, then washing fastness is improved, but the texture of the colored fabric hardens and water-insoluble film is generated causing nozzle clogging
Solution Approach 1:
The patent changes the chemical parameters of the fixing agent by using water-soluble polymers with specific functional groups (carboxyl, hydroxyl, amine) instead of conventional emulsion resins. The molecular weight is controlled within specific ranges (5,000-100,000) to achieve optimal balance between fixation performance and fabric softness, eliminating the need for large amounts of resin that cause hardening.
Solution Approach 2:
The patent creates a composite fixing system combining water-soluble polymer dispersants with specific functional groups that provide both pigment dispersion and fixation functions. This composite approach replaces the conventional separate system of emulsion resin for fixation, achieving fastness without the harmful water-insoluble film formation.
2Adaptability or versatility
If pigments are used as colorant in inkjet printing, then coloring of any fibers is enabled with simple method, but long-term storage stability and jetting stability are poor and nozzle clogging occurs
Solution Approach 1:
The patent introduces water-soluble polymer dispersants with specific functional groups as intermediaries between pigments and the inkjet system. These dispersants form stable complexes with pigments, preventing aggregation during storage and ensuring smooth jetting. The functional groups (carboxyl, hydroxyl, amine) act as mediators that maintain pigment dispersion stability without requiring emulsion resins.
Solution Approach 2:
The patent optimizes the molecular weight parameters of the water-soluble polymer dispersants within specific ranges (5,000-100,000) to achieve the right balance between pigment binding capability and solubility. This parameter control ensures long-term storage stability and prevents nozzle clogging while maintaining universal fiber coloring capability.
3Reliability
If conventional pigment dispersion is used for inkjet printing, then pigment fixation on fibers is achieved, but the colored fabric lacks soft texture and good fastness quality
Solution Approach 1:
The patent changes the chemical composition parameters of the fixing agents by selecting water-soluble polymers with specific functional groups and molecular weights (5,000-100,000). These parameter changes enable effective pigment fixation while preventing fabric hardening, maintaining soft texture and good fastness quality simultaneously.
Solution Approach 2:
The patent uses water-soluble polymer dispersants that can be easily rinsed from the fabric after fixation, unlike conventional emulsion resins that form permanent water-insoluble films. This approach allows the fixing agents to perform their function temporarily during processing and then be removed, preventing texture degradation.
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 enables stable inkjet printing with fine pattern generation, firm pigment fixation on fibers, and a soft, high-quality colored fabric with improved fastness, addressing the limitations of previous pigment-based methods.
Implementation Method 1
a crosslinking agent (C), which undergoes a crosslinking reaction at 100° C or more
Data Source
AI summary
An inkjet printing ink having properties of crosslinking and being fixed on a fiber by heating, characterized in that in an ink composition consisting of (A) a pigment dispersion having a mean particle diameter of 200 nm or less and a maximum particle diameter of 500 nm or less, consisting of a pigment, a water-soluble pigment dispersant and a hydrophilic solvent, (B) a water-soluble fixing agent, and (C) a crosslinking agent, the water-soluble pigment dispersant in (A) is a specific emulsion polymer neutralized by a basic substance; the water-soluble fixing agent (B) is the one having a crosslinking functional group; and the crosslinking agent (C) is the one having a functional group that crosslinks the crosslinking functional group of the water-soluble pigment dispersant in (A) with the crosslinking functional group of the water-soluble fixing agent (B) at a temperature of 100° C. or more.