Aqueous Inkjet Paint Composition with Polyacrylate-Polyurethane Binder
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Solution Overview
Problem
Conventional inkjet inks face issues with adhesion, water or solvent resistance, optical density, gloss, and nozzle clogging due to their water-based composition and high solids content, particularly in DOD inkjet processes, where they also tend to foam and produce unsatisfactory prints.
Innovation Solution
An aqueous lacquer composition comprising a binder composition of polyacrylate and polyurethane with a high binder solids content, combined with humectants like 1,3-butanediol, butyl diglycol, and glycerin, which allows for high layer thickness printing without the need for defoaming agents, ensuring improved gloss, durability, and adhesion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the binder solids content is increased to improve gloss and film thickness, then the coating quality improves, but the liquid tends to dry out and clog the nozzles
Solution Approach 1:
The patent applies parameter changes by carefully adjusting the humectant composition (specific ratios of 1,3-butanediol, butyldiglycol, and glycerin) and binder solids content (20-60 wt%) to achieve optimal balance between film quality and nozzle stability. This quantitative optimization resolves the contradiction between high gloss requirements and nozzle clogging prevention.
Solution Approach 2:
The patent uses a composite humectant system combining three different diols/glycerin compounds with complementary properties. This composite approach provides synergistic effects where each component contributes differently to preventing drying while maintaining jetting stability, thereby preventing nozzle clogging even at high binder solids content.
2Ease of manufacture
If conventional aqueous inkjet inks are used, then the composition is simple and easy to manufacture, but adhesion to hydrophobic surfaces and water resistance are poor
Solution Approach 1:
The patent employs a composite binder system combining polyacrylate and polyurethane with specific functional groups. This composite material provides both hydrophobic interactions for adhesion to hydrophobic surfaces and water resistance, while maintaining compatibility with aqueous formulation for ease of manufacture.
Solution Approach 2:
The patent optimizes the molecular weight ranges and functional group compositions of the binder polymers to enhance adhesion and water resistance properties. By carefully selecting polymer parameters within specific ranges, the ink achieves improved performance while remaining manufacturable through conventional processes.
3Object-generated harmful factors
If defoaming agents are added to prevent foaming, then foam formation is reduced, but the composition complexity increases and may affect print quality
Solution Approach 1:
The patent achieves foam control through the self-regulating properties of the optimized humectant and binder composition. The specific combination of 1,3-butanediol, butyldiglycol, and glycerin creates a formulation that inherently suppresses foam formation through controlled surface tension and viscosity, eliminating the need for additional defoaming agents.
4Reliability
If the liquid is circulated continuously in DOD printheads to prevent nozzle drying, then nozzle stability is improved, but the liquid may foam during recirculation
Solution Approach 1:
The patent adjusts the viscosity and surface tension parameters through optimized humectant composition to prevent foam formation during recirculation. The specific ratio of polyols and glycerin creates a liquid formulation that remains stable under continuous circulation conditions without generating harmful foam, while maintaining nozzle stability.
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 composition achieves high jetting stability, slow drying behavior, and excellent adhesion and scratch resistance, producing layers with enhanced gloss and durability in DOD inkjet printing, suitable for various substrates including food packaging, without the use of defoaming agents.
Implementation Method 1
at least one humectant, wherein the humectant is a combination of 1,3-butanediol, butyldiglycol and glycerin
Implementation Method 2
an aqueous coating composition can be printed well using the DOD (Dead On-Desk) process without the addition of a defoaming agent
Data Source
AI summary
The present invention relates to an aqueous paint composition for producing a paint layer in an inkjet process, wherein the aqueous paint composition comprises a binder composition comprising a polyacrylate and a polyurethane, at least one humectant, and water, and is characterized in that it has a binder solids content of at least 20 wt.%, based on the total weight of the paint composition.