Thixotropic Coating Composition for High-Speed Smooth Battery Coatings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing coating compositions lack clear understanding of properties contributing to high-speed coating and surface smoothness, with existing patents not adequately addressing these aspects.
Innovation Solution
A coating composition with a specific viscosity ratio at high and low shear rates, containing a filler with an aspect ratio of 2 or more, a binder of diene rubber or (meth)acrylate polymer, and a thixotropy index of 1.1×10^6 or more, which includes poly-N-vinylcarboxylic acid amide or polyvinylpyrrolidone as a thickener, achieving excellent surface smoothness and high-speed coating properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a coating composition is applied at high speed, then productivity is improved, but surface smoothness deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the viscosity ratio at different shear rates. Specifically, it sets the viscosity at low shear rate (0.01/s) to be 1.0×10^6 Pa·s or less and the viscosity at high shear rate (10000/s) to achieve a thixotropy index of 1.1×10^6 or more. This parameter optimization allows the coating to maintain smoothness at high application speeds by controlling how viscosity changes with shear rate, resolving the contradiction between coating speed and surface quality
Solution Approach 2:
The patent utilizes the dynamic property of thixotropy in the coating composition. By designing a composition with specific thixotropic behavior where viscosity decreases under high shear (during high-speed coating) and recovers at low shear (after coating), the system adapts its properties during the coating process. This dynamic viscosity adjustment enables high-speed application while maintaining surface smoothness, as the coating becomes less viscous during application but regains structure afterward
2Productivity
If the viscosity at low shear rate is reduced, then high-speed coating properties are improved, but coating stability deteriorates
Solution Approach 1:
The patent applies parameter changes by independently optimizing viscosity parameters at different shear rates. It sets the viscosity at low shear rate (0.01/s) to 1.0×10^6 Pa·s or less to improve flow and application properties, while simultaneously controlling the viscosity at high shear rate to maintain a thixotropy index of 1.1×10^6 or more. This dual parameter control allows the coating to flow easily during application while maintaining compositional stability and preventing settling or separation when stored
3Manufacturing precision
If the thixotropy index is increased, then surface smoothness is improved, but coating composition complexity increases
Solution Approach 1:
The patent applies parameter changes by defining specific numerical ranges for viscosity and thixotropy index that achieve smooth surfaces without requiring complex formulations. By setting the viscosity at low shear rate to 1.0×10^6 Pa·s or less and the thixotropy index to 1.1×10^6 or more, the patent provides clear, quantifiable parameters that guide composition design. This approach simplifies the development process by providing target parameters rather than requiring trial-and-error with complex formulations
Solution Approach 2:
The patent discards the need for complex additive packages and intricate formulation strategies by focusing on fundamental viscosity and thixotropy parameters. By identifying and optimizing these core parameters, the patent recovers simplicity in formulation approach while achieving the desired surface smoothness, eliminating the need for multiple complex additives and processing steps
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 enables the formation of a smooth coated film even at high speeds, improving production efficiency for applications like lithium-ion secondary batteries by preventing lithium dendrite growth and ensuring uniform coatings.
Implementation Method 1
a viscosity of the coating composition is 1.0×10^6 Pa·s or less as measured at a shear rate of 0.01/s; and the following thixotropy index (TI) is 1.1×10^6 or more: thixotropy index (TI)=[viscosity of the coating composition as measured at a shear rate of 0.01/s]/[viscosity of the coating composition as measured at a shear rate of 10000/s]
Data Source
AI summary
A coating composition can be applied with excellent high-speed coating properties and surface smoothness in a paint, an ink, and an adhesive which mainly contain polymers, or is a coating liquid for a positive electrode, a negative electrode, a separator, and the like of a lithium-ion secondary battery. The coating composition contains a filler, a binder, a thickener, and a solvent, wherein an aspect ratio of the filler is 2 or more, the binder is at least one selected from a diene rubber and a (meth)acrylate polymer, a viscosity of the coating composition is 1.0×106 Pa·s or less as measured at a shear rate of 0.01/s, and the following thixotropy index (TI) is 1.1×106 or more: [thixotropy index (TI)]=[viscosity of the coating composition as measured at a shear rate of 0.01/s]/[viscosity of the coating composition as measured at a shear rate of 10000/s].