Cationic Dispersion Polymer Coatings for Inkjet Water Fastness
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Solution Overview
Problem
Achieving good ink jet print quality on substrates like standard coated offset paper or multi-purpose paper is challenging due to the difficulty in fixing colorants at the surface without bleeding or feathering, and existing polymers either absorb into the substrate or increase viscosity, requiring costly specialty coatings.
Innovation Solution
Using hydrophilic cationic dispersion polymers applied to the substrate surface, which include repeating units derived from nonionic and hydrophilic cationic monomers, to enhance film forming capabilities and improve ink fixation without the need for specialty coatings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solution polymers are used to promote fixation of anionic ink and improve water fastness, then water fastness is improved and print bleeding is decreased, but print optical density is limited and costly specialty coating additives are required
Solution Approach 1:
The patent changes the molecular weight parameter of the polymer from low (solution polymers) to high (latex polymers), which improves film forming capability and print optical density while maintaining water fastness properties. This parameter change allows achieving both improved water fastness and better print quality without requiring additional costly additives.
Solution Approach 2:
The patent creates a composite coating formulation combining high molecular weight cationic latex polymer with starch and other standard size press additives. This composite approach allows the latex polymer to provide both ink fixation (improving water fastness) and film forming capability (improving optical density), while being compatible with standard press formulations.
2Manufacturing precision
If high molecular weight latex polymers are used to improve film forming capability, then print optical density is improved, but viscosity of coating formulation increases drastically precluding use in standard size press formulations
Solution Approach 1:
The patent optimizes the molecular weight parameter of the latex polymer to achieve a balance between film forming capability and viscosity. By selecting specific molecular weight ranges and polymer compositions, the formulation achieves sufficient film forming for good optical density while maintaining viscosity levels compatible with standard size press formulations.
Solution Approach 2:
The patent utilizes the porous and absorbent nature of paper substrates to advantage. The coating formulation is designed to be applied in a manner that allows penetration into the paper matrix, where the polymer can form a film structure that provides good optical density without requiring high surface concentration that would increase viscosity issues.
3Manufacturing precision
If specialty coating formulations containing silica and insoluble pigments are used to achieve good print quality, then ink fixation is improved, but cost increases and formulation complexity increases
Solution Approach 1:
The patent extracts and eliminates the need for costly specialty additives like silica and insoluble pigments from the coating formulation. By using high molecular weight cationic latex polymer as the primary active ingredient, the formulation achieves good ink fixation and print quality through the polymer's inherent film forming and ink binding capabilities, removing the need for additional functional additives.
Solution Approach 2:
The patent makes the coating formulation universal by designing it to work with standard size press formulations and standard paper substrates. The high molecular weight cationic latex polymer provides multiple functions: ink fixation, film forming, and compatibility with standard press additives, eliminating the need for specialized coating formulations and complex multi-component systems.
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 hydrophilic cationic dispersion polymers enhance ink jet printability by improving optical density and water fastness, reducing the need for specialty coatings, and enhancing print quality on substrates like standard coated offset paper or multi-purpose paper.
Implementation Method 1
such solution polymers are poor film formers and thus tend to absorb into the substrate rather than adhere to its surface
Implementation Method 2
concomitant absorption of the water phase of the ink into the substrate
Data Source
AI summary
Hydrophilic cationic dispersion polymers, compositions including same, and methods of using same. In some examples, a composition can include a hydrophilic cationic dispersion polymer disposed on a surface of a substrate. The substrate can be a paper, a textile, a non-woven material, a film, or mixtures thereof. The hydrophilic cationic dispersion polymer can include repeating units derived from a first monomer and a second monomer. The first monomer can be a nonionic monomer and the second monomer can be at least one hydrophilic cationic monomer selected from a diallyl-N,N-dimethylammonium halide and a monomer of the formula I: where A1 can be O or NH; B1 can be a C2-C4 alkylene or hydroxypropylene; R1 can be H or CH3; R2 and R4 can independently be a C1-C2 alkyl; R3 can be H or a C1-C2 alkyl; and X1 can be an anionic counterion.