Polyurethane Resin Ink for Adhesion on Low-Polar Media
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ink jet recording on low-absorbent or non-absorbent recording media using pigment inks faces challenges with adhesion and abrasion resistance due to the pigment's tendency to remain on the surface, and existing solutions like adding urethane resin do not adequately address these issues for both polar and low-polar base materials.
Innovation Solution
An aqueous ink jet ink composition is developed, incorporating a polyurethane resin dispersion formed from a high-molecular-weight polyol and organic polyisocyanate, with specific polyolefin and polyester polyol constituents, along with optional low-molecular-weight polyols and additives like silicone emulsion or polyolefin wax, to enhance adhesion and scratch resistance on various base materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If pigment is used as coloring material to achieve high color development, then color intensity is improved, but adhesion and abrasion resistance deteriorate because pigment remains on the surface
Solution Approach 1:
The patent introduces a polyurethane resin as an intermediary substance between the pigment and the recording medium. The resin forms a film that binds the pigment particles to the medium, acting as a mediator that transfers and secures the pigment while providing adhesion and abrasion resistance that pigment alone cannot achieve
Solution Approach 2:
The invention creates a composite ink composition combining pigment particles with polyurethane resin in specific ratios (pigment 1-20 mass%, resin 0.1-10 mass%). This composite structure allows the pigment to provide color development while the resin matrix provides adhesion and mechanical strength, resolving the contradiction between color intensity and durability
2Reliability
If urethane resin is added to improve adhesion, then adhesion is improved, but the ink film characteristics become insufficient on both polar and low-polar base materials
Solution Approach 1:
The patent modifies the chemical structure parameters of the polyurethane resin by incorporating specific polyol components (polyester polyol with number-average molecular weight 500-5000, polyether polyol with number-average molecular weight 500-5000) and controlling the isocyanate index (100-200). These parameter changes enable the resin to adapt to different base material polarities while maintaining adhesion performance
Solution Approach 2:
The designed polyurethane resin achieves multi-functionality by simultaneously providing adhesion to both polar base materials (PET, nylon) and low-polar base materials (OPP, polypropylene). The resin's molecular structure and composition are optimized to create universal compatibility across different material types, eliminating the need for material-specific ink formulations
3Reliability
If pigment is used to achieve fastness properties, then light resistance and water resistance are improved, but abrasion resistance deteriorates due to surface localization
Solution Approach 1:
The invention creates a composite ink film where pigment particles (0.1-20 mass%) are embedded within a polyurethane resin matrix (0.1-10 mass%). This composite structure allows pigment to maintain its fastness properties (light resistance, water resistance) while the resin matrix provides the mechanical strength and abrasion resistance that surface-localized pigment alone cannot provide
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 ink composition achieves excellent adhesion and scratch resistance on both polar and low-polar base materials, improving the overall performance of ink films in terms of durability and image quality.
Implementation Method 1
the pigment stays on the surface of the recording medium due to the evaporation and penetration of vehicle components occurring during the process of attaching ink to the recording medium
Implementation Method 2
the pigment stays on the surface of the recording medium due to the evaporation and penetration of vehicle components
Data Source
AI summary
An ink jet ink composition which is an aqueous ink includes a resin dispersion, in which the resin dispersion is a polyurethane resin dispersion formed of a polyurethane resin (U) obtained by reacting an active hydrogen atom-containing component (A) containing a high-molecular-weight polyol component (a1) having a number-average molecular weight of 500 or more and an organic polyisocyanate component (B), and the high-molecular-weight polyol component (a1) includes a polyolefin polyol (a11) having a constituent unit represented by General Formula (1) and/or a constituent unit represented by General Formula (2), and a polyester polyol (a12) having a constituent unit represented by General Formula (3).