Silicone Gel Composition for High-Temperature Electronic Sealing
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Solution Overview
Problem
Conventional silicone gel compositions fail to provide adequate heat resistance and transparency at high temperatures, and cold resistance at low temperatures, leading to deterioration when used in electronic components under severe conditions.
Innovation Solution
A silicone gel composition comprising branched organopolysiloxane, organohydrogenpolysiloxane, a platinum-based catalyst, and a reaction product of alkali metal silanolate and ceric salt, which enhances heat resistance and maintains transparency and low elastic modulus even at high temperatures, while providing excellent cold resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If filler such as carbon or iron oxide is filled to increase heat resistance, then heat resistance is improved, but transparency decreases and viscosity increases
Solution Approach 1:
The patent changes the chemical composition parameters by introducing cerium compounds and specific organopolysiloxane structures (branched and cyclic) to achieve heat resistance without relying on traditional carbon black fillers that compromise transparency. This allows the material to maintain optical clarity while withstanding temperatures up to 200°C or higher.
Solution Approach 2:
The patent creates a composite silicone gel system combining multiple components: cerium compounds, branched organopolysiloxane, cyclic organopolysiloxane, and organohydrogenpolysiloxane. This composite approach achieves both heat resistance and transparency by distributing functional properties across different molecular structures rather than relying on opaque particulate fillers.
2Strength
If conventional silicone gel composition is used, then low elastic modulus and low stress are achieved, but heat resistance at high temperatures deteriorates
Solution Approach 1:
The patent modifies the chemical composition by incorporating cerium compounds and specific polysiloxane structures while maintaining the addition reaction cure mechanism. This allows the gel to retain its low crosslinking density (for low elastic modulus) while the cerium compounds provide thermal stability at high temperatures through chemical bonding that prevents degradation.
Solution Approach 2:
The cerium compounds act as an intermediary substance that mediates between the conflicting requirements of low elastic modulus and high heat resistance. The cerium forms thermal-stable bonds within the gel network that provide heat resistance without creating the high crosslinking density that would increase elastic modulus.
3Reliability
If conventional silicone gel-cured material is used under severe temperature conditions, then basic sealing function is provided, but deterioration occurs due to insufficient heat resistance and cold resistance
Solution Approach 1:
The patent optimizes the composition parameters including the ratio of branched to cyclic organopolysiloxane, the amount of cerium compound (0.01-5 mass%), and the molecular structure to achieve both high-temperature stability (up to 200°C) and low-temperature flexibility (down to -40°C or lower). These parameter changes enable the gel to withstand severe temperature cycling without deterioration.
Solution Approach 2:
The patent creates a multi-component composite system where cerium compounds provide thermal stability, branched organopolysiloxane provides structural integrity at high temperatures, and the overall composition maintains low crosslinking density for flexibility at low temperatures. This composite structure achieves reliable performance across extreme temperature ranges.
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 silicone gel composition achieves excellent heat resistance above 200°C, maintains transparency, and exhibits low elastic modulus and stress, ensuring durability and reliability of electronic components under severe temperature conditions.
Implementation Method 1
a platinum-based catalyst; and the addition reaction curable organopolysiloxane compositions provide cured materials that are gel-like and have low crosslinking density via an addition reaction of silicon-bonded hydrogen atom to the alkenyl group
Data Source
AI summary
A silicone gel composition comprising: (A) branched organopolysiloxane having, on average, at least two alkenyl groups bonded to silicon atoms in a molecule, and a viscosity ranging from 10 to 10,000 mPa·s at 25° C.; (B) organohydrogenpolysiloxane; (C) platinum-based addition reaction catalyst; and (D) a reaction product of (d1) alkali metal silanolate with (d2) at least one ceric salt selected from cerium chloride and a carboxylic acid salt of cerium.