Crosslinked Polymer Dispersant for Stable Pigment Ink Dispersion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pigment dispersions in ink compositions lack sufficient temporal stability, leading to degradation over time.
Innovation Solution
A pigment dispersion comprising water, a pigment, and a polymer dispersant with a crosslinking structure, containing specific structural units represented by Formulas (1) and (2), along with a hydrophilicity/hydrophobicity ratio and Ar valence that enhance the dispersant's affinity to the pigment, preventing its release and aggregation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a polymer dispersant with crosslinking structure is used to improve dispersion stability, then the temporal stability of the pigment dispersion is improved, but the complexity of the dispersant structure increases
Solution Approach 1:
The polymer dispersant is segmented into multiple functional structural units: Formula (1) units providing crosslinking capability through aromatic groups, Formula (2) units providing hydrophobic interaction through long alkyl chains, and acid group units for neutralization. This segmentation allows each unit to perform its specific function while maintaining overall system stability without excessive complexity.
Solution Approach 2:
The patent optimizes specific parameters of the polymer dispersant: the ratio of Formula (1) to Formula (2) structural units, the degree of neutralization of acid groups (10-90%), and the resulting hydrophilicity/hydrophobicity ratio (≥8). These parameter changes enable the dispersant to achieve optimal temporal stability while controlling structural complexity.
2Reliability
If the polymer dispersant contains long alkyl groups to enhance hydrophobic interaction with pigment, then the affinity to pigment is improved, but the hydrophilicity of the dispersant decreases
Solution Approach 1:
The polymer dispersant exhibits local quality differentiation: Formula (2) units with long alkyl groups (8-30 carbon atoms) provide hydrophobic interaction with pigment particles, while Formula (1) units with aromatic groups and acid groups provide hydrophilic interactions with water. This local differentiation allows simultaneous optimization of pigment affinity and aqueous compatibility.
Solution Approach 2:
The polymer dispersant is a composite material combining multiple functional units: hydrophobic alkyl groups for pigment interaction, hydrophilic aromatic groups and acid groups for water interaction, and crosslinking structures for stability. This composite structure resolves the contradiction between hydrophobicity and hydrophilicity by integrating both characteristics in appropriate proportions.
3Stability of the object's composition
If crosslinking is performed to prevent dispersant release, then temporal stability is improved, but the manufacturing process complexity increases
Solution Approach 1:
The polymer dispersant is prepared with pre-installed crosslinking capability through the incorporation of Formula (1) units containing aromatic groups and acid groups during polymer synthesis. The crosslinking reaction is then performed in a single step by adding a crosslinking agent to the aqueous pigment dispersion, avoiding complex multi-step manufacturing processes while achieving stable temporal performance.
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 dispersion achieves excellent temporal stability by suppressing the release and aggregation of the polymer dispersant, thereby maintaining stability over time.
Implementation Method 1
a polymer dispersant having a crosslinking structure... suppressing the release and aggregation of the polymer dispersant
Implementation Method 2
the polymer dispersant having a crosslinking structure further contains a structural unit represented by Formula (1) and a structural unit represented by Formula (2)
Implementation Method 3
a hydrophilicity/hydrophobicity ratio represented by the following expression is 8 or more
Data Source
AI summary
Provided are a pigment dispersion containing water, a pigment, and a polymer dispersant having a crosslinking structure, in which the polymer dispersant having a crosslinking structure contains a structural unit represented by Formula (1) and a structural unit represented by Formula (2); and an ink composition. R1 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R2 represents an alkylene group having 2 to 5 carbon atoms, R3 represents an aromatic group, X1 and X2 each independently represent —O— or —NH—, m represents an integer of 2 or more, R4 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R5 represents an alkyl group having 8 or more carbon atoms, and X3 represents —O— or —NH—.