Aqueous Inkjet Lamination Primers and Inks for Thin Film Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current printing technologies for laminates, particularly in the packaging industry, face challenges such as the use of harmful solvents, contamination risks from uncured monomers, and limitations in press speed and width, especially with UV-curable inkjet fluids, which are impractical for thin plastic films and pose health hazards.
Innovation Solution
The use of aqueous pigmented inkjet printing inks with anionic polymeric dispersions, low solvent content, and resoluble properties, combined with a single pass printing process and a primer coating, to achieve strong laminate bonds and reduce environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If UV-curable inkjet fluids are used for printing, then printing speed and press width can be increased, but harmful solvents and uncured monomers migrate into packaged materials causing contamination
Solution Approach 1:
The patent changes the chemical composition parameters of the inkjet fluid by using water-based pigmented inks with resin dispersions instead of UV-curable inks. This substitution eliminates photoinitiators and uncured monomers while maintaining acceptable drying times through controlled evaporation and resin coagulation, thereby removing the contamination hazard while preserving productivity
Solution Approach 2:
The patent employs water-based inks that are designed to dry quickly through evaporation without requiring UV curing. The use of resins with controlled molecular weights and hydrophobic groups enables the ink to form stable films rapidly, replacing the need for UV-curable systems that pose health and safety concerns
2Quantity of substance
If 100% solids content radiation-curable inkjet fluids are used, then film weight deposition is high, but thin plastic films (12 μm or less) distort during ink curing and shrinking
Solution Approach 1:
The patent adjusts the solvent content and resin composition parameters to create water-based inks with controlled drying characteristics. The use of resins with specific molecular weights (5,000-500,000) and hydrophobic groups allows the ink to evaporate and form films without the severe shrinkage associated with UV-curable inks, preventing distortion of thin plastic films while maintaining adequate film weight deposition
Solution Approach 2:
The patent utilizes the phase transition of water from liquid to vapor during drying, combined with the coagulation of resin dispersions, to form stable ink films. This phase transition mechanism allows for controlled film formation without the rapid polymerization shrinkage that causes distortion in UV-curable systems, enabling successful printing on thin plastic films
3Strength
If conventional printing processes (flexographic, gravure, offset) are used, then laminate bond strength is achieved, but the process complexity and environmental impact increase
Solution Approach 1:
The patent extracts and eliminates the need for separate primer layers and complex multi-step conventional printing processes. By formulating water-based pigmented inks with resin dispersions that provide both adhesion and film-forming properties, the invention achieves laminate bond strength directly through the ink layer itself, simplifying the overall process while maintaining bonding performance
Solution Approach 2:
The patent creates a multi-functional inkjet ink that simultaneously provides coloration, adhesion to substrates, and film-forming capabilities. The resin dispersion components serve multiple roles including binder, adhesion promoter, and film former, eliminating the need for separate primer layers and reducing process complexity while maintaining laminate bond strength
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
This approach enables high-speed, wide-width printing with improved laminate bond strength, reduced contamination risk, and enhanced sustainability by simplifying material layers for easier recycling.
Implementation Method 1
an anionic polymeric dispersion or an anionic solution polymer (also known as an alkali-soluble polymer), more preferably an anionic polyurethane dispersion, is used as a binder in the aqueous pigmented inkjet printing ink
Implementation Method 2
applying a primer to a first substrate... wherein the primer is an aqueous coating composition comprising: (a) a water-dispersible polymer and a multivalent metal salt; or (b) a water-soluble polymer
Implementation Method 3
printing an aqueous pigmented inkjet printing ink onto the primed substrate of step (i) via a single pass printing operation
Implementation Method 4
laminating a second substrate to the primed and printed first substrate of steps (i) and (ii)
Data Source
AI summary
Digitally printed laminates prepared from an aqueous primer coating composition and an aqueous pigmented inkjet printing ink wherein the primer coating composition comprises: (a) a water-dispersible polymer and a multivalent metal salt; or (b) a water-soluble polymer selected from copolymers comprising vinyl alcohol and vinyl acetate, copolymers comprising vinyl alcohol and vinyl amine, poly(vinyl pyrrolidone), copolymers comprising vinyl pyrrolidone and vinyl acetate, modified celluloses and water-soluble starches; a water-soluble aminated polymer comprising any blend of primary or secondary amines as part of its molecular structure; and a multivalent metal salt; and wherein the aqueous pigmented inkjet printing ink comprises an anionic polymeric dispersion or an anionic solution polymer.