Waterborne Polyurethane Ink Microphase Separation for Scratch-Off
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solvent-based scratch-off inks pose environmental and health risks due to high volatile organic compound (VOC) emissions and residual harmful substances, and they require a significant amount of organic solvent, exceeding 7 wt %.
Innovation Solution
A waterborne polyurethane (WPU) is developed, which reduces the organic solvent dosage in scratch-off inks to less than 2 wt %, by utilizing a specific molecular structure that facilitates microphase separation during film formation, enhancing scratch-off performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solvent-based scratch-off ink is used, then scratch-off performance is achieved, but volatile organic compound (VOC) emissions increase and environmental harm occurs
Solution Approach 1:
The patent changes the chemical composition parameters of the ink by replacing solvent-based resins with waterborne polyurethane resin, reducing organic solvent content from exceeding 7 wt% to less than 2 wt%, thereby maintaining scratch-off performance while significantly reducing VOC emissions
Solution Approach 2:
The patent uses a composite formulation combining waterborne polyurethane resin with specific additives including scratch-off agents (wax, oil), pigments, and functional auxiliaries to create an environmentally friendly ink that achieves both protective and scratch-off functions without relying on high levels of organic solvents
2Object-generated harmful factors
If organic solvent dosage is reduced to less than 2 wt %, then environmental friendliness is improved, but ink formulation complexity increases
Solution Approach 1:
The patent systematically adjusts multiple formulation parameters including resin molecular weight (10,000-50,000), hydroxyl value (30-70 mg KOH/g), and additive concentrations to optimize performance at low solvent levels, transforming a complex formulation challenge into a standardized production process
Solution Approach 2:
The patent introduces water as the primary carrier medium to replace organic solvents, and uses surfactants and dispersants as intermediary substances to ensure proper mixing and stability of the water-based formulation, thereby simplifying the overall system despite reduced solvent content
3Object-generated harmful factors
If waterborne polyurethane resin is used, then VOC emissions are reduced, but scratch-off performance may deteriorate
Solution Approach 1:
The patent formulates a composite system where waterborne polyurethane resin serves as the base binder, enhanced with specific scratch-off agents (wax, oil, grease), pigments, and functional additives that work synergistically to provide both environmental benefits and reliable scratch-off performance
Solution Approach 2:
The patent creates localized functional zones within the ink film by strategically distributing different components: the waterborne polyurethane provides the matrix structure, while scratch-off agents concentrate in specific regions to ensure easy removal, and additives are positioned to enhance specific properties without compromising overall performance
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 WPU-based waterborne scratch-off ink achieves excellent scratch-off properties with reduced VOC emissions and lower organic solvent content, addressing environmental and health concerns while maintaining effective performance.
Implementation Method 1
microphase separation may occur during the film-forming process owing to a hydrophobic/hydrophilic interaction between the non-polar long-chain alkyl and polar groups (such as carboxyl, carbamate) in WPU molecular
Implementation Method 2
microphase separation may occur during the film-forming process owing to a hydrophobic/hydrophilic interaction between the non-polar long-chain alkyl and polar groups (such as carboxyl, carbamate) in WPU molecular
Implementation Method 3
removing the acetone by distillation at the temperature and a pressure of 0.01 MPa to 0.09 MPa to obtain the waterborne polyurethane
Data Source
AI summary
Provided are a waterborne polyurethane (WPU) and a preparation method thereof, and a waterborne scratch-off ink and a preparation method thereof. A chain end group or side group of the WPU contains a longer alkyl chain. When the WPU is used in the preparation of the waterborne scratch-off ink, microphase separation may occur during the film-forming process owing to a hydrophobic/hydrophilic interaction between the non-polar long-chain alkyl and polar groups in WPU molecular, resulting in an incomplete film structure, which is beneficial to make the ink be scratched off.