PVB Interlayer Film for LIDAR NIR Transparency
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Solution Overview
Problem
Existing interlayer films for laminated glazing in vehicles, particularly for LIDAR applications, suffer from dye agglomeration leading to light scattering and inadequate transparency in the NIR and IR ranges, posing a safety hazard due to impaired sensor functionality.
Innovation Solution
Development of a polyvinyl acetal-based interlayer film with a low plasticizer content and homogeneously distributed radiation absorbers, such as perylenes, ensuring high transmission and low haze, and minimal dye migration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If radiation absorbers are added to the interlayer film to achieve NIR absorption, then LIDAR sensor functionality is improved, but dye agglomeration occurs causing light scattering and increased haze
Solution Approach 1:
The patent changes the chemical composition parameters of the radiation absorber by specifying exact structural formulas with defined substituents (R1-R10) and using specific compound classes (azo dyes, anthraquinones, perylenes) to achieve homogeneous distribution in the PVB matrix without agglomeration, thereby maintaining optical clarity while providing NIR absorption
Solution Approach 2:
The patent creates a composite material system combining polyvinyl acetal (PVB) with specifically selected radiation absorber compounds, where the absorbers are molecularly dispersed within the polymer matrix through controlled formulation, achieving both NIR absorption and visual clarity without scattering
2Reliability
If radiation absorbers are added to the interlayer film to achieve NIR absorption, then LIDAR sensor functionality is improved, but transmission in the visible range decreases
Solution Approach 1:
The patent applies local quality by designing the radiation absorber to have selective absorption characteristics - strongly absorbing in the NIR range (905 nm) for LIDAR applications while maintaining high transmission in the visible range (380-780 nm), thus providing different optical properties for different wavelength regions
Solution Approach 2:
The patent specifies precise absorption characteristics through parameter control, requiring greater than 80% transmission at 905 nm while limiting visible light transmission to less than 20%, achieved by selecting specific dye compounds with appropriate spectral absorption profiles
3Ease of manufacture
If plasticizer is added to the interlayer film to improve flexibility and processability, then film manufacturing is improved, but dye migration and bleeding occur
Solution Approach 1:
The patent optimizes the plasticizer content parameter by limiting it to a maximum of 20 wt% (preferably 0-5 wt%), which provides sufficient flexibility and processability while minimizing the plasticizer-induced dye migration and bleeding that would otherwise compromise composition stability
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 provides enhanced transparency and stability, reducing light scattering and ensuring consistent sensor performance by minimizing dye migration and absorption in the NIR range, while maintaining low haze and UV protection.
Implementation Method 1
the film has more than 80% transmission for radiation with a wavelength of 905 nm, a haze of less than 5% and a transmission for radiation with a wavelength of 380-780 nm of less than 20%
Data Source
AI summary
The invention is directed to interlayer films suitable for LIDAR applications in windshields.