Curable Silicone Composition Storage Stability
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Solution Overview
Problem
Conventional curable silicone compositions exhibit inadequate storage stability at room temperature, which is a limitation for their application in encapsulants for optical semiconductors.
Innovation Solution
A curable silicone composition comprising a resinous alkenyl group-containing organopolysiloxane with at least two alkenyl groups per molecule, an organohydrogenpolysiloxane with two silicon atom-bonded hydrogen atoms, an alkyne group-containing compound, and a platinum-based catalyst, where the alkenyl group-containing organopolysiloxane constitutes 20 mass % or more of the total mass, enhancing storage stability and thermal curing properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional curable silicone compositions are used, then thermal curability is maintained, but storage stability at room temperature is inadequate
Solution Approach 1:
The patent changes the chemical parameters of the silicone composition by incorporating specific resinous alkenyl group-containing organopolysiloxane with controlled molecular weight and alkenyl group content (0.5-5 mol%), along with organohydrogenpolysiloxane and catalyst in specific ratios. These parameter changes enable the composition to maintain stability during storage while remaining curable under thermal conditions, resolving the contradiction between storage stability and curability.
Solution Approach 2:
The patent creates a composite material system combining multiple components: resinous alkenyl group-containing organopolysiloxane, organohydrogenpolysiloxane, platinum catalyst, and optional modifiers. This composite approach allows each component to contribute specific properties - the resinous polysiloxane provides structural stability, the hydrogen-containing component enables curing, and the catalyst facilitates the reaction - achieving both storage stability and thermal curability simultaneously.
2Reliability
If addition curing type silicone composition is used, then room temperature storage stability is improved, but curing reaction may proceed at room temperature causing premature curing
Solution Approach 1:
The patent applies local quality by using a platinum catalyst in very small amounts (0.01-5 ppm) specifically designed to remain dormant during storage and activate only under thermal conditions. The catalyst is incorporated in such small quantities and with specific support materials that it does not initiate premature curing at room temperature but effectively catalyzes the hydrosilylation reaction when heated, thus preventing premature curing while enabling reliable thermal curing.
Solution Approach 2:
The composition is formulated in advance with all necessary components (alkenyl-containing polysiloxane, hydrogen-containing polysiloxane, and catalyst) pre-mixed in precise ratios that ensure stability during storage. The preliminary formulation includes stability-enhancing modifiers and controls the molecular structure of the polysiloxanes to prevent premature reaction while maintaining the ability to cure when heated, effectively preparing the system for reliable thermal curing without premature activation.
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 composition achieves excellent storage stability at room temperature with a long pot life and maintains thermal curability, allowing for effective sealing of optical semiconductor devices.
Implementation Method 1
a curable organopolysiloxane composition which cures by means of a hydrosilylation reaction is used as a protective coating, encapsulant, etc.
Implementation Method 2
an effective amount of hydrosilylation catalyst microparticles that have a microcapsule structure containing a platinum-group metal catalyst-containing organic compound or polymer compound
Data Source
AI summary
A Curable Silicone Composition, Encapsulant And Optical Semiconductor Device provides a curable silicone composition having excellent storage stability at room temperature. A curable silicone composition having (A) a resinous alkenyl group-containing organopolysiloxane including at least two alkenyl groups per molecule and at least one siloxane unit represented by SiO4/2; (B) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in one molecule; (C) an alkyne group-containing compound; and (D) a curing catalyst, wherein the content of the resinous alkenyl group-containing organopolysiloxane (A) is 20 mass % or more based on the total mass of the organopolysiloxane components.