Epoxy-Modified Silicone Fine Particles for Uniform Epoxy Dispersion
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Solution Overview
Problem
Existing encapsulating materials for electronic devices, particularly those using epoxy resins, face challenges such as aggregation of additives, poor adhesion, and insufficient stress relaxation, which affect the mechanical properties and reliability of the encapsulated components.
Innovation Solution
The development of epoxy-modified silicone fine particles with a core-shell structure, where spherical silicone rubber fine particles are coated with a polyorganosilsesquioxane containing an epoxy group-containing alicyclic hydrocarbon group, addresses the issues of aggregation, adhesion, and stress relaxation by providing excellent dispersibility and bonding with the epoxy resin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicone rubber powder is added to epoxy resin for stress relaxation, then stress relaxation effect is improved, but compatibility with epoxy resin deteriorates causing poor uniform dispersion
Solution Approach 1:
The invention changes the surface parameters of silicone rubber particles by coating them with polyorganosilsesquioxane having epoxy groups, transforming the incompatible silicone rubber surface into a form that is chemically compatible with epoxy resin. This parameter change enables both stress relaxation and uniform dispersion.
Solution Approach 2:
The invention creates a composite structure where silicone rubber particles are coated with polyorganosilsesquioxane. This composite material combines the stress relaxation properties of silicone rubber with the epoxy compatibility of polyorganosilsesquoxane, resolving the contradiction between stress relaxation effect and dispersion uniformity.
2Ease of operation
If epoxy-modified low-molecular-weight silicone is added to epoxy resin for fluidity improvement, then fluidity is improved, but compatibility deteriorates causing poor mixing uniformity
Solution Approach 1:
The invention changes the molecular weight parameter from low-molecular-weight silicone to fine particle form with controlled size distribution, and modifies the surface chemistry by coating with polyorganosilsesquoxane. This enables both fluidity improvement and mixing uniformity.
3Stability of the object's composition
If acrylic resin is used as coating on silicone particles, then dispersibility is improved, but adhesion to epoxy resin deteriorates due to lack of chemical bonding
Solution Approach 1:
The invention changes the chemical composition of the coating from acrylic resin to polyorganosilsesquoxane containing epoxy groups. This parameter change maintains the dispersibility benefits while adding chemical bonding capability for adhesion to epoxy resin.
Solution Approach 2:
The invention creates a composite coating material that combines the dispersibility of polymer coatings with the adhesion of epoxy-functionalized silanes. The polyorganosilsesquoxane coating provides both steric stabilization for dispersibility and chemical bonding for adhesion.
4Reliability
If sufficient amount of epoxy-modified low-molecular-weight silicone is added for stress relaxation, then stress relaxation effect is improved, but compatibility deteriorates making uniform mixing difficult
Solution Approach 1:
The invention changes the form from low-molecular-weight liquid silicone to fine particle form with controlled size distribution (0.1-100 μm). This parameter change enables stress relaxation effect while improving handling and mixing characteristics.
Solution Approach 2:
The invention creates composite particles with silicone rubber core and polyorganosilsesquoxane shell, combining the stress relaxation properties of silicone rubber with the processability and compatibility of epoxy-functionalized silane coating.
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 use of these epoxy-modified silicone fine particles results in a thermosetting resin composition with improved mechanical properties, such as bending strength and bending modulus of elasticity, while preventing aggregation and enhancing adhesion within the epoxy resin matrix.
Implementation Method 1
the polyorganosilsesquioxane (B) has an epoxy group-containing organic group... have a chemical reaction point with a thermosetting resin, particularly with an epoxy resin, they have excellent adhesion and bonding property with the resins
Implementation Method 2
epoxy-modified silicone fine particle having a core-shell structure which is obtained by coating spherical silicone rubber fine particle with a polyorganosilsesquioxane... does not aggregate in a thermosetting resin and, therefore, has excellent dispersibility
Data Source
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AI summary
One of the purposes of the present invention is to provide silicone fine particles which do not aggregate in a thermosetting resin, while having softness derived from silicone rubber and having excellent adhesion with the thermosetting resin. The other purpose is to provide a method for preparing the same. The other purpose is to provide a thermosetting resin composition and an encapsulating material, each comprising the fine particles. The present invention provides an epoxy-modified silicone fine particle composed of (A) a spherical silicone rubber fine particle coated with (B) polyorganosilsesquioxane, wherein the spherical silicone rubber fine particle (A) has an average particle diameter of 0.1 to 100 µm and the polyorganosilsesquioxane (B) has an epoxy group-containing organic group.