Addition-Curable Silicone Composition for Optical Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing addition-curable silicone compositions for optical applications face challenges in achieving high transparency, low refractive index, excellent light extraction efficiency, and good rubber and strength properties while minimizing tack after curing, particularly with poor light transmittance at 400 nm and increased refractive index due to organohydrogen polysiloxane volatility.
Innovation Solution
A composition comprising a linear organopolysiloxane with silicon atom-bonded aliphatic unsaturated groups and CF3—(CF2)y—(CH2)z— groups, an organopolysiloxane with branched structures, an organosilicon compound represented by a specific general formula, and a platinum group metal-based catalyst, which together provide a cured product with low refractive index, high transparency, and improved light extraction efficiency without tack.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a branched organopolysiloxane with phenyl groups is used to achieve high refractive index (1.53-1.54), then the refractive index is improved, but the cured product becomes hard and loses elasticity
Solution Approach 1:
The patent changes the chemical composition parameters by introducing fluorine-containing groups (CF3-(CF2)y-(CH2)z-) to replace some phenyl groups, thereby lowering the refractive index from 1.53-1.54 to a lower value while maintaining elasticity. This parameter modification allows simultaneous achievement of optical performance and mechanical flexibility.
Solution Approach 2:
The patent uses a composite approach by combining linear organopolysiloxane (component A) with fluorine-containing groups and organohydrogen polysiloxane (component C) in specific ratios. This composite composition enables the cured product to achieve both low refractive index and good elasticity that cannot be obtained with single-component branched organopolysiloxane.
2Stability of the object's composition
If organohydrogen polysiloxane with low molecular weight is used to improve compatibility, then compatibility is improved, but the organohydrogen polysiloxane is volatilized during device production and tack remains after curing
Solution Approach 1:
The patent modifies the molecular weight parameter of organohydrogen polysiloxane to be within the specific range of 500-10,000, optimizing it to prevent volatilization during device production while maintaining good compatibility. This parameter optimization ensures the polysiloxane remains stable and prevents tack formation after curing.
Solution Approach 2:
The patent selects organohydrogen polysiloxane with appropriately high molecular weight (500-10,000) in advance to cushion against the harmful effect of volatilization during subsequent device production processes. This preliminary selection prevents tack formation before the curing process completes.
3Illumination intensity
If organohydrogen polysiloxane is used to achieve low refractive index, then refractive index is reduced, but transparency remarkably decreases
Solution Approach 1:
The patent optimizes the fluorine-containing group content parameter within specific ranges (y: 0-9, z: 1-10) to achieve the right balance between refractive index reduction and transparency maintenance. By controlling these parameters, the cured product achieves low refractive index while maintaining high transparency and excellent light extraction efficiency.
Solution Approach 2:
The patent creates a composite system combining linear organopolysiloxane with fluorine-containing groups (component A) and organohydrogen polysiloxane (component C) in optimized ratios. This composite approach allows the fluorine-containing groups to lower refractive index while the overall composition maintains transparency and light extraction efficiency.
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 solution achieves a cured product with high transparency, low refractive index, excellent light extraction efficiency, and good rubber and strength properties, ensuring excellent transmittance of light across a wide spectrum and improved reliability by preventing tack formation during curing.
Implementation Method 1
An addition-curable silicone composition includes an organopolysiloxane containing an aliphatic unsaturated group such as an alkenyl group and an organopolysiloxane containing a silicon atom-bonded hydrogen atom (SiH group), and is cured by a hydrosilylation reaction
Data Source
AI summary
The present invention provides an addition-curable silicone composition comprising: (A) a linear organopolysiloxane having silicon atom-bonded aliphatic unsaturated groups and CF3—(CF2)y—(CH2)z— groups; (B) an organopolysiloxane having silicon atom-bonded aliphatic unsaturated groups and CF3—(CF2)y—(CH2)z— groups, and having a branched structure represented by SiO4/2 and RSiO3/2; (C) an organosilicon compound having silicon atom-bonded hydrogen atoms and represented by the following general formula (1); and (D) a platinum group metal-based catalyst. There can be provided an addition-curable silicone composition that provides a cured product having low refractive index, high transparency, excellent light extraction efficiency, good rubber properties and strength properties, and no tack after curing, and in particular, has good transmittance of light with a wavelength of 400 nm at 25° C.