Ink Composition Rubbing Resistance via Resin-TiO2 Composite
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Solution Overview
Problem
Conventional white ink compositions using titanium dioxide for inkjet printing suffer from insufficient resistance to rubbing and poor secondary color density, particularly when used on non-white surfaces.
Innovation Solution
An inkjet ink composition comprising titanium dioxide with an average primary particle diameter of 200 nm or more, combined with self-dispersing resin particles having an average particle diameter of 30 nm or less, and a water-soluble resin, which includes structural units with benzyl or phenoxy groups, enhancing re-dispersibility and image durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If titanium dioxide with large average primary particle diameter is used to achieve favorable whiteness, then whiteness is improved, but the ink composition becomes easily precipitated or solidified, resulting in insufficient resistance to rubbing
Solution Approach 1:
The invention uses a composite system combining titanium dioxide particles (200-500 nm) with resin particles (5-50 nm) containing specific functional groups. The resin particles act as a matrix or coating on the titanium dioxide surface, creating a composite structure that maintains the whiteness of large-particle TiO2 while preventing precipitation and improving rubbing resistance through the resin component.
Solution Approach 2:
The resin particles containing carboxyl, hydroxyl, or amine groups serve as an intermediary between the titanium dioxide particles and the ink vehicle. These resin particles coat or interact with the TiO2 surface, preventing direct aggregation and precipitation of the large-particle titanium dioxide while maintaining its light-scattering properties for whiteness.
2Ease of manufacture
If titanium dioxide precipitates or solidifies in the ink composition, then the ink may be easier to handle, but the formed image has insufficient resistance to rubbing and poor secondary color density
Solution Approach 1:
The invention extracts the problematic precipitation tendency of large-particle titanium dioxide by introducing resin particles that selectively bind to the TiO2 surface. The resin component is taken out as a separate functional element that addresses the stability issue without compromising the TiO2's optical properties.
Solution Approach 2:
By creating a composite of titanium dioxide and resin particles, the invention achieves a system where the resin component prevents precipitation while the TiO2 maintains its light-scattering capability. This composite structure ensures both proper ink handling and high-quality image formation with good rubbing resistance and color density.
3Area of stationary object
If white ink composition is used on non-white surfaces, then the surface coverage is improved, but the secondary color density becomes insufficient
Solution Approach 1:
The invention changes the particle size parameters of both titanium dioxide (200-500 nm) and resin particles (5-50 nm) to optimize the balance between surface coverage and color density. The specific size range allows the ink to form a uniform white base layer while maintaining sufficient pigment concentration for vibrant secondary colors.
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 superior resistance to rubbing and high secondary color density, ensuring better image quality and durability on various surfaces.
Implementation Method 1
self-dispersing resin particles having an average particle diameter of 30 nm or less, wherein a resin included in the self-dispersing resin particles includes at least one of a structural unit having a benzyl group or a structural unit having a phenoxy group
Implementation Method 2
self-dispersing resin particles... enhancing re-dispersibility
Implementation Method 3
titanium dioxide having an average primary particle diameter of 200 nm or more... favorable whiteness
Implementation Method 4
titanium dioxide... favorable whiteness
Implementation Method 5
a water-soluble resin... enhances re-dispersibility
Data Source
AI summary
An ink composition for an inkjet including titanium dioxide having an average primary particle diameter of 200 nm or more; a water-soluble resin; self-dispersing resin particles having an average particle diameter of 40 nm or less; and water.