Polyamide-imide Electrodeposition Dispersion Viscosity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing electrodeposition dispersions face challenges with storage stability, leading to increased viscosity and foaming during drying or sintering of the coating film, which complicates the formation of insulating films with desired thickness.
Innovation Solution
A water-based electrodeposition dispersion containing polyamide-imide polymer particles, an organic solvent, and a nitrogen-containing basic compound with a Hansen Solubility Parameter (HSP) distance from water of 35 or greater, such as alkylamine compounds, is developed to enhance storage stability and prevent foaming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If polyimide particles having an anionic group are used to increase dispersibility, then electrostatic repulsion between particles increases and storage stability improves, but the kind of monomer that can be used is restricted and manufacturing cost increases
Solution Approach 1:
The invention changes the chemical structure parameter of the polymer by using polyamide-imide instead of polyimide, and specifically controls the anionic group content to 0.1-10 mmol/g. This parameter optimization maintains electrostatic repulsion for dispersibility while avoiding the need for expensive specialized monomers like diamines with carboxyl or sulfonic acid groups
Solution Approach 2:
The invention creates a composite electrodeposition dispersion system combining polyamide-imide polymer particles with specific inorganic additives (such as colloidal silica or aluminum hydroxide). This composite approach enhances storage stability through synergistic effects while providing flexibility in monomer selection, reducing manufacturing costs
2Shape
If a water-soluble polyamide-imide resin is used to form a continuous film, then film formation improves, but electrodeposition efficiency is reduced and it becomes difficult to form an insulating film having a desired thickness
Solution Approach 1:
The invention optimizes the solubility parameter of polyamide-imide by controlling the anionic group content within 0.1-10 mmol/g and adjusting the polymer structure. This creates partial water solubility that allows sufficient film formation while maintaining electrodeposition efficiency, avoiding the complete water solubility problem of conventional polyamide-imide resins
Solution Approach 2:
The invention applies partial water solubility rather than complete solubility by limiting anionic group content. This partial action provides just enough water compatibility for film formation while preventing excessive solubility that would cause continuous film formation and reduced electrodeposition efficiency
3Stability of the object's composition
If the electrodeposition dispersion is stored for a long period of time, then storage stability is tested, but viscosity increases and foaming occurs during drying or sintering
Solution Approach 1:
The invention performs preliminary stabilization by optimizing the polymer structure and adding specific inorganic additives (colloidal silica, aluminum hydroxide) before storage. This preliminary action prevents viscosity increase and foaming during subsequent storage and processing, eliminating the need for corrective measures later
Solution Approach 2:
The invention introduces inorganic additives such as colloidal silica or aluminum hydroxide as intermediary substances that mediate between the polymer particles and water. These intermediaries prevent particle aggregation and viscosity increase during storage, and suppress foaming during drying or sintering by acting as defoaming agents
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 solution effectively suppresses viscosity increase and foaming, ensuring stable film formation even after long-term storage, maintaining the desired thickness and quality of the insulating film.
Implementation Method 1
the basic compound is a nitrogen-containing compound in which a HSP distance from water is 35 or greater
Implementation Method 2
a direct current is allowed to flow to a to-be-coated material dipped in an electrodeposition coating material (electrodeposition dispersion) and an electrode inserted into the electrodeposition coating material to precipitate electric coating material particles on the to-be-coated material side
Implementation Method 3
since polyimide particles having an anionic group in the molecule are used, the surface potential of the particles is high, and dispersibility increases due to electrostatic repulsion between the particles
Data Source
Figure 1
AI summary
A water-based electrodeposition dispersion for forming an insulating film contains polymer particles, an organic solvent, a basic compound, and water, the polymer particles are made of polyamide-imide, and the basic compound is a nitrogen-containing compound in which the HSP distance from water is 35 or greater.