Polyvinyl Acetal Dispersant for Dielectric Particle Agglomeration
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Solution Overview
Problem
The agglomeration of fine dielectric particles in multilayer ceramic capacitors due to electrostatic properties leads to non-uniform dielectric properties and manufacturing challenges, with existing dispersants being less researched and less effective.
Innovation Solution
A polyvinyl acetal-based dispersant with a low degree of polymerization (100-200), specific functional group ratios (hydroxyl, acetal, and acetyl groups), and a non-aqueous homogeneous reaction method to improve dispersibility and prevent agglomeration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fine dielectric particles are used to achieve miniaturization and high capacitance, then the size and capacitance performance improve, but agglomeration occurs due to electrostatic properties leading to non-uniform dielectric properties
Solution Approach 1:
A dispersant comprising polyvinyl alcohol and polyvinyl acetal is introduced as an intermediary substance between dielectric particles. The dispersant contains hydroxyl groups that interact with particle surfaces and provides steric hindrance to prevent agglomeration, thereby maintaining uniform dielectric properties throughout the slurry.
Solution Approach 2:
The patent optimizes specific parameters of the dispersant including the ratio of polyvinyl alcohol to polyvinyl acetal (1:9 to 9:1), degree of polymerization (100-200), and functional group composition (hydroxyl groups 10-40 mol%, acetal groups 50-85 mol%, acetyl groups 5-20 mol%). These parameter changes enhance dispersibility and prevent agglomeration while maintaining manufacturing precision.
2Reliability
If conventional dispersants are used, then the manufacturing process is simple, but dispersibility of dielectric particles is insufficient leading to poor uniformity
Solution Approach 1:
The dispersant is formulated as a composite material combining polyvinyl alcohol and polyvinyl acetal in specific ratios. This composite structure leverages the hydrophilic nature of polyvinyl alcohol and the hydrophobic characteristics of polyvinyl acetal to achieve superior dispersibility in organic solvent-based slurries, improving reliability without excessive complexity.
3Reliability
If the degree of polymerization of the dispersant is high, then the structural stability improves, but the dispersibility and uniformity of the slurry deteriorate
Solution Approach 1:
The degree of polymerization of both polyvinyl alcohol and polyvinyl acetal is controlled within the range of 100-200. This parameter optimization ensures the dispersant chains are long enough to provide steric stabilization but not so long that they cause excessive viscosity or poor solubility, thereby achieving both dispersibility and structural stability.
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 dispersant enhances the uniformity and reliability of ceramic green sheets, improves dielectric layer microstructure, and optimizes the ceramic green sheet manufacturing process, reducing agglomeration and improving the dispersibility of dielectric particles.
Implementation Method 1
a polyvinyl acetal-based resin having a degree of polymerization in a range from 100 to 200, an amount of hydroxyl groups in a range from 4 mol % to 40 mol %, an amount of acetal groups in a range from 40 mol % to 95 mol %, and an amount of acetyl groups in a range from 1 mol % to 20 mol %
Implementation Method 2
a dispersant may be added to disperse the dielectric particle in a process of manufacturing the components
Implementation Method 3
an amount of hydroxyl groups in a range from 4 mol % to 40 mol %
Data Source
AI summary
A dispersant includes a polyvinyl acetal-based resin having a degree of polymerization in a range from 100 to 200, an amount of hydroxyl groups in a range from 4 mol % to 40 mol %, an amount of acetal groups in a range from 40 mol % to 95 mol %, and an amount of acetyl groups in a range from 1 mol % to 20 mol %.