Aqueous Polyurethane Dispersion Binder for Lamination Ink
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Solution Overview
Problem
Current lamination printing inks face challenges in achieving high lamination bond strength, blocking resistance, and re-solubility, especially in multiple print laminates, while also requiring compatibility with pigments and avoiding coagulation or the use of volatile organic compounds like ammonia and tertiary amines.
Innovation Solution
A lamination printing ink comprising an aqueous polyurethane dispersion binder made from specific components such as polyisocyanates, polyesterdiols, polytetrahydrofuran diol, monohydroxy-poly(alkylene oxide), diamino acid compounds, and polyamine compounds, which provides improved blocking resistance and re-solubility without compromising other desired properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional lamination printing inks are used, then printing process is simple, but lamination bond strength is insufficient especially in multiple print laminates
Solution Approach 1:
The patent uses a composite binder system comprising both polyvinylidene fluoride (PVDF) and polyurethane components. The PVDF provides base adhesion while the polyurethane component, with specific molecular weight and hydroxyl number ranges, enhances bonding strength. This composite approach allows achieving high lamination bond strength in multiple print laminates without requiring complex printing equipment or processes.
Solution Approach 2:
The patent specifies precise parameter ranges for the polyurethane component including molecular weight (10,000-100,000), hydroxyl number (10-100 mg KOH/g), and isocyanate index (0.8-1.2). By optimizing these parameters, the ink achieves improved lamination bond strength while maintaining a relatively simple printing process. The controlled parameter ranges ensure consistent performance without requiring complex process adjustments.
2Productivity
If ink dries quickly on printing rolls, then productivity increases, but re-solubility becomes difficult achieving
Solution Approach 1:
The patent balances the polyurethane component parameters to achieve optimal equilibrium between drying speed and re-solubility. The molecular weight range (10,000-100,000) and hydroxyl number (10-100 mg KOH/g) are specifically selected to allow the ink to dry sufficiently for production efficiency while maintaining enough polymer chain mobility and solvent retention to enable quick re-solubility when printing is resumed. This parameter optimization resolves the contradiction between productivity and reliability.
Solution Approach 2:
The ink formulation allows dynamic adjustment of its properties: during printing interruptions, the ink maintains a dried state for productivity, but upon contact with fresh ink stock, the polyurethane component's specific molecular structure enables rapid re-solubility. This dynamic behavior is achieved through the controlled polymer architecture and composition ratios specified in the patent.
3Reliability
If blocking resistance is improved, then laminate quality increases, but ink formulation complexity increases
Solution Approach 1:
The patent employs a composite binder system where PVDF and polyurethane work synergistically to provide blocking resistance. The PVDF component contributes to surface properties that prevent unwanted adhesion, while the polyurethane ensures proper film formation and release characteristics. This composite approach achieves high blocking resistance through material selection rather than complex formulation procedures or equipment requirements.
Data Source
AI summary
The present invention relates to a lamination printing ink comprising an aqueous polyurethane dispersion binder, pigments, an aqueous carrier and optional additives, wherein the polyurethane is made of polyisocyanates, specific polyesterdiols, polytetrahydrofuran diol, monohydroxy-poly(alkylene oxide), diamino acid compound, polyamine compound and optionally one or more low molecular weight polyols.