Inkjet Laminate Primer Composition for Adhesion and Color Bleed Control
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Solution Overview
Problem
Existing inkjet printing technologies face challenges in achieving high-quality print quality on substrates like coated paper and polymeric films due to insufficient ink wetting and intercolor bleed, and insufficient layer-to-layer adhesion during lamination, especially in regulated sectors such as food and pharmaceuticals, requiring complex and costly adjustments.
Innovation Solution
Aqueous polymer compositions comprising a specific polyurethane with anionic and terminal non-ionic hydrophilic groups, a coagulating agent, and optionally an acrylic binder, applied as a primer to enhance inkjet printing on plastic substrates, providing excellent adhesion and intra-layer cohesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional primers (water-soluble metal salt and cationic/non-ionic polymer) are used, then inkjet printing on substrates is enabled, but adhesion to substrate and intra-layer cohesion are insufficient, especially after pasteurization
Solution Approach 1:
The invention changes the chemical parameters of the primer by using a specific anionic polyurethane with terminal non-ionic hydrophilic groups instead of conventional cationic or non-ionic polymers. This parameter change enables the primer to maintain adhesion and cohesion even after pasteurization treatment, resolving the reliability issue without requiring complex process adjustments
Solution Approach 2:
The invention creates a composite primer system combining anionic polyurethane with specific hydrophilic terminal groups and coagulating agents. This composite material structure provides both adhesion to the substrate and intra-layer cohesion, eliminating the need for separate tie-layers or complex surface treatments
2Reliability
If surface energy adjustment (corona discharge, plasma discharge, flame ionization) or tie-layer is applied, then adhesion is improved, but process complexity and costs increase
Solution Approach 1:
The invention extracts the adhesion-enhancing function from complex surface treatment devices (corona discharge, plasma discharge, flame ionization) and tie-layers, and concentrates it into the chemical structure of the primer itself. The anionic polyurethane with terminal hydrophilic groups inherently provides adhesion without requiring external surface energy adjustment equipment
Solution Approach 2:
The invention eliminates the need for an intermediate tie-layer by incorporating the tie-layer function directly into the primer composition. The anionic polyurethane acts as both the adhesive binder and the interface agent between substrate and adhesive layer, removing the complexity of separate intermediate layers
3Productivity
If inkjet ink is applied directly on polymeric films, then printing is enabled, but insufficient ink wetting and intercolor bleed occur
Solution Approach 1:
The invention applies a preliminary primer treatment to the polymeric film surface before inkjet printing. The anionic polyurethane primer creates a receptive surface that enhances ink wetting and prevents intercolor bleed, enabling high-quality printing without requiring ink formulation adjustments
4Reliability
If coating is applied to substrates, then substrate protection is achieved, but inkjet printing quality deteriorates
Solution Approach 1:
The invention applies the primer locally as a thin coating layer between the substrate and the inkjet ink. This local quality change creates a printing-receptive surface without compromising the overall substrate protection, as the primer layer is specifically designed to enhance ink wetting while maintaining substrate integrity
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 primer compositions ensure stable, homogeneous, and re-dispersible layers with high-quality inkjet printing and adhesion, suitable for laminates used in food and pharmaceutical packaging, without gelling or sedimentation over time.
Implementation Method 1
a coagulating agent
Data Source
AI summary
Aqueous polymer compositions useful as primers for the preparation of inkjet printed laminates comprise a) a polyurethane with anionic and terminal non-ionic hydrophilic groups, obtained from hydrogenated diphenylmethane-4,4'-diisocyanate and a non-ionic polyester diol; b) a coagulating agent selected in the group consisting of water-soluble multivalent metal salts, water-soluble organic acids and mixtures thereof and, c) optionally, an acrylic binder.