Optical Filler Silicone Composition for High-Index Gap Injection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-refractive index liquid silicone compositions are unable to be injected into small gaps due to high overall viscosity, leading to insufficient gap filling and potential process defects in injection molding for electronic and electrical devices.
Innovation Solution
A curable liquid silicone composition with a refractive index of 1.47 or more at 25°C and 847 nm, and a viscosity of 500 mPa·s or less at 25°C, containing organosilicon compounds with alkenyl groups and monovalent functional groups, along with silicon-bonded hydrogen atoms and a hydrosilylation reaction catalyst.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high refractive index liquid silicone composition is used, then light extraction efficiency is improved, but viscosity becomes too high for injection into small gaps
Solution Approach 1:
The patent changes the chemical composition parameters of the silicone material by incorporating specific organosilicon compounds with aromatic groups (phenyl, tolyl, xylyl) and controlling the ratio of crosslinking agents to base polymers. This compositional parameter adjustment achieves a refractive index of 1.47 or higher while maintaining viscosity at 500 mPa·s or lower, enabling both high light extraction efficiency and easy injection into sub-millimeter gaps
Solution Approach 2:
The patent creates a composite silicone composition by combining multiple organosilicon compounds with different functional groups (alkenyl for crosslinking, aromatic for refractive index enhancement) and crosslinking agents (silicon-bonded hydrogen compounds). This composite approach allows simultaneous optimization of optical properties (refractive index) and rheological properties (viscosity) that cannot be achieved with single-component materials
2Reliability
If high refractive index composition is used, then interfacial reflection is reduced, but gap filling becomes insufficient due to high viscosity
Solution Approach 1:
The patent adjusts the viscosity parameter to 500 mPa·s or lower at 25°C through selective compound composition, enabling the material to flow completely into small gaps during injection molding while maintaining high refractive index (1.47 or more) for effective optical coupling and reduced interfacial reflection, ensuring both complete gap filling and high sealing quality
3Ease of operation
If low viscosity is achieved for injection molding, then ease of injection is improved, but refractive index may be compromised
Solution Approach 1:
The patent simultaneously optimizes multiple composition parameters: incorporating aromatic-containing organosilicon compounds to boost refractive index while selecting low-viscosity base polymers and controlling molecular weight distribution to maintain viscosity at 500 mPa·s or lower, achieving both excellent injection flowability and high optical performance with refractive index of 1.47 or more
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 low viscosity for easy injection into small gaps, quick curing at room temperature or with heat treatment, and a high refractive index in both visible and infrared regions, making it suitable for devices using infrared LED light sources.
Implementation Method 1
a curable liquid silicone composition, contains: (A) one or more types of organosilicon compound selected from the following component (A1) and component (A2)... (C) a compound having at least two silicon-bonded hydrogen atoms in a molecule... (D) a hydrosilylation reaction catalyst
Data Source
AI summary
[Problem] To provide: a photocurable liquid silicone composition having a low viscosity that facilitates injection into a small gap, having a refractive index after curing that is high not only in a visible region but also in an infrared region, and that is particularly useful as a material for a device using an infrared LED light source; and an application thereof. [Resolution Means] A curable liquid silicone composition, containing: (A): (A1) an organosilane or organopolysiloxane having 1 to 5 silicon atoms, having an alkenyl group, and having at least one monovalent functional group selected from aromatic groups and aralkyl groups, and/or (A2) an organopolysiloxane having 2 to 5 silicon atoms, having an alkenyl group, and not having a monovalent functional group selected from aromatic groups and aralkyl groups; (C) a compound having at least two silicon-bonded hydrogen atoms; and (D) a hydrosilylation reaction catalyst; wherein the refractive index of the entire liquid composition prior to curing is 1.47 or more, and the viscosity is 500 mPa·s or less.