Spherical Silica Particles from Silicic Acid for Resin Filling
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Solution Overview
Problem
Existing methods for producing spherical silica particles, such as the Stöber method and emulsion synthesis, are costly due to the use of high-purity tetraethoxysilane (TEOS) or sodium silicate, and result in low resin filling ability and high impurity levels.
Innovation Solution
A method using an alkaline silicic acid aqueous solution as a raw material, combined with a basic substance like quaternary ammonium or cyclic amidine, to produce spherical silica particles, allowing control over particle size distribution and purity, and involving a heating step to remove organic substances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the Stöber method is used to produce spherical silica particles, then high sphericity and uniformity among particle diameters are achieved, but resin filling ability deteriorates
Solution Approach 1:
The patent changes the fundamental parameters of the synthesis method by using silicic acid instead of TEOS, and employing a mixed solvent system with specific relative permittivity (21-40) rather than the conventional Stöber method parameters. This produces spherical silica particles with improved resin filling ability while maintaining high sphericity
2Manufacturing precision
If high-purity TEOS is used as raw material, then high-purity spherical silica particles are obtained, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive high-purity TEOS with cheaper silicic acid as the raw material. The use of silicic acid in an alkaline aqueous solution provides a cost-effective alternative that still produces high-purity spherical silica particles through the controlled precipitation process
Solution Approach 2:
The patent changes the raw material parameter from TEOS to silicic acid, and adjusts the solvent system to a mixed solvent with specific relative permittivity (21-40). This parameter change enables production of high-purity particles at lower cost
3Shape
If emulsion synthesis method using sodium silicate is used, then spherical porous silica is obtained, but cost increases due to large sodium content requiring rinsing
Solution Approach 1:
The patent replaces sodium silicate with silicic acid as the raw material. This substitution eliminates the sodium content problem that requires costly rinsing operations, while still producing spherical silica particles with the desired morphology
Solution Approach 2:
The patent extracts/removes the harmful sodium component from the raw material system by using silicic acid instead of sodium silicate. This eliminates the need for rinsing operations to remove excess sodium, reducing manufacturing cost
4Ease of manufacture
If silicic acid is used instead of TEOS, then cost decreases, but particle size distribution control becomes more difficult
Solution Approach 1:
The patent introduces a mixed solvent system with controlled relative permittivity (21-40) and specifies a quaternary ammonium blending ratio (0.3-0.8 molar ratio). These parameter changes enable effective control of particle size distribution when using silicic acid, overcoming the difficulty associated with silicic acid-based synthesis
5Productivity
If a mixed solvent with relative permittivity of 21-40 is used, then spherical silica particles with excellent filling ability are produced, but device complexity increases
Solution Approach 1:
The patent specifies a mixed solvent with relative permittivity in the range of 21-40, which optimizes the precipitation process to produce spherical silica particles with excellent filling ability. The quaternary ammonium additive at controlled blending ratio (0.3-0.8) further refines particle morphology and distribution
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 method produces spherical silica particles with improved purity and filling ability, using less expensive materials and enabling control over particle size distribution, resulting in high-quality silica particles suitable for electronic devices.
Implementation Method 1
a raw material silica particle preparation step of preparing a liquid dispersion of raw material silica particles from a raw material solution obtained by dissolving silicic acid in a mixed solvent of water and an organic solvent in the presence of a basic substance
Implementation Method 2
a heating step of heating the liquid dispersion or the raw material silica particles obtained from the liquid dispersion through solid-liquid separation so as to remove an organic substance contained in the liquid dispersion
Data Source
AI summary
A method for producing spherical silica particles according to the present disclosure includes: a raw material silica particle preparation step of preparing a liquid dispersion of raw material silica particles from a raw material solution obtained by dissolving silicic acid in a mixed solvent of water and an organic solvent in the presence of a basic substance; and a heating step of heating the liquid dispersion or the raw material silica particles so as to remove an organic substance contained in the liquid dispersion, thereby preparing spherical silica particles. The mixed solvent has a relative permittivity of 21 or higher and 40 or lower, and a quaternary ammonium derived from the basic substance is blended in a blending ratio of 0.3 or higher and 0.8 or lower in terms of molar ratio with respect to a silicon element derived from the silicic acid.