Textile Inkjet Ink Composition With Cross-Linked Polyurethane Binder
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Solution Overview
Problem
Existing ink-jet inks for textile printing lack stability and superior jetting properties, failing to produce durable, high-quality images on various substrates due to limitations in cross-linking methods and binder compatibility.
Innovation Solution
Development of an ink-jet ink comprising an aqueous vehicle, a cross-linked pigment dispersion prepared by dispersing a colorant with a polyurethane dispersant followed by cross-linking, and a cross-linked polyurethane binder that is non-reactive to the colorant, using specific polyurethane dispersants and cross-linking agents like epoxide, isocyanate, and carbodiimide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If melamine crosslinker is used for cross-linking, then cross-linking effectiveness is improved, but elevated temperature and acidic conditions are required which limit substrate compatibility
Solution Approach 1:
The patent changes the chemical parameters of the cross-linking system by replacing melamine crosslinker with alternative crosslinkers (isocyanate, carbodiimide, silane, epoxide) that operate under different conditions. This allows cross-linking to occur at neutral pH and moderate temperatures, expanding substrate compatibility while maintaining cross-linking effectiveness.
Solution Approach 2:
The patent uses readily available, easy-to-handle crosslinking agents that work under mild conditions, replacing the specialized melamine system. These alternative crosslinkers enable printing on a broader range of substrates including temperature-sensitive and pH-sensitive materials without requiring harsh processing conditions.
2Stability of the object's composition
If polyurethane dispersant is cross-linked, then dispersion stability is improved, but binder compatibility and jetting properties may be compromised
Solution Approach 1:
The patent separates the functions of dispersant and binder into distinct components. The dispersant (polyvinyl alcohol or carboxymethyl cellulose) provides dispersion stability, while the binder (polyurethane or acrylic polymer) provides jetting properties and image durability. This segmentation allows each component to optimize its function without interference from cross-linking of the dispersant.
Solution Approach 2:
The patent uses a coupling agent or surfactant as an intermediary between the cross-linked dispersant and the binder system. This intermediary maintains compatibility between the cross-linked dispersant particles and the aqueous binder, ensuring stable jetting properties while preserving the enhanced dispersion stability provided by cross-linking.
3Ease of manufacture
If conventional screen printing is used, then setup expense is high, but pattern consistency and durability are reliable
Solution Approach 1:
The patent develops a universal inkjet ink formulation that can print on multiple substrate types (textile, paper, plastic) with consistent durability. The combination of cross-linked dispersant for stability and compatible binder for adhesion creates a multi-functional system that achieves screen-printing-level durability through digital printing, eliminating the need for substrate-specific ink formulations.
Solution Approach 2:
The patent creates a composite ink system combining cross-linked dispersant particles with polymer binder in an aqueous vehicle. This composite structure provides both the dispersion stability needed for jetting and the adhesion properties needed for durable images, achieving reliability comparable to screen printing while maintaining the flexibility and low setup cost of digital printing.
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 provides stable, high-quality ink-jet inks with improved jetting properties, enabling durable and high-quality image formation on textiles without the need for melamine crosslinkers, which allows for printing without elevated temperature or acidic conditions.
Implementation Method 1
an aqueous pigment dispersion prepared by dispersing a colorant with a polyurethane dispersant followed by cross-linking of the dispersant
Implementation Method 2
a cross-linked polyurethane binder which is different from the polyurethane dispersant and non-reactive to the colorant
Data Source
AI summary
This disclosure relates to novel aqueous ink-jet inks having improved image properties containing an aqueous vehicle, a cross-linked pigment dispersion, and a cross-linked polyurethane binder. The inks are particularly advantageous for printing on textile.