NIR Transparent Black Pigment Solid Solution for LiDAR
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dark-colored coatings, such as those using carbon black, absorb near-infrared radiation, leading to increased temperatures and interference with LiDAR signals, particularly for autonomous vehicles, and existing perylene-based pigments have low-crystallinity and insufficient coloristic performance.
Innovation Solution
A solid solution comprising specific perylene-based compounds, formulated to provide a near-infrared transparent black pigment with improved coloristic properties, including neutral hue, high black values, and low chroma, achieved through a process involving mechanical treatment, addition of suitable acids and solvents, and solid-liquid separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If carbon black or conventional black pigments are used to achieve dark colors and aesthetic purposes, then the black value and aesthetic appeal are improved, but near-infrared radiation absorption increases leading to temperature increase and LiDAR signal interference
Solution Approach 1:
The patent applies local quality by designing a pigment that has different optical properties at different wavelengths: it absorbs visible light (400-700 nm) to provide black color while transmitting near-infrared radiation (700-2500 nm). This wavelength-selective property allows the pigment to simultaneously achieve high black value and NIR transparency, resolving the contradiction between aesthetic appearance and thermal/LiDAR performance.
Solution Approach 2:
The invention uses composite materials by combining specific perylene-based compounds (formulas I, II, and III) with complementary absorption characteristics to create a solid solution. The composite structure leverages the individual strengths of each compound to achieve broad visible light absorption while maintaining NIR transparency, thus improving black value without increasing NIR absorption.
2Illumination intensity
If physical mixtures of perylene-based pigments are used to achieve required coloristics, then the color performance is improved, but the coloristic varies significantly depending on dispersion conditions and pigment levels
Solution Approach 1:
The patent merges multiple perylene-based compounds into a single solid solution phase where the components are molecularly dispersed and interact at the molecular level. This merging eliminates the variability associated with physical mixtures and dispersion conditions, as the solid solution structure ensures consistent coloristic performance regardless of processing variations.
Solution Approach 2:
The invention achieves homogeneity by creating a solid solution where the perylene-based compounds are uniformly distributed at the molecular level within a single crystal structure. This homogeneous distribution ensures that the coloristic properties remain consistent across different concentrations and application conditions, resolving the variability issue of physical mixtures.
3Stability of the object's composition
If high temperature calcination in vacuum or inert gas atmosphere is used to produce perylene-based solid solutions, then the solid solution structure is achieved, but the process complexity and manufacturing difficulty increase
Solution Approach 1:
The patent applies parameter changes by modifying the synthesis conditions from extreme high temperature vacuum/inert atmosphere calcination to milder aqueous-phase chemical reactions at lower temperatures. This parameter change enables the formation of solid solutions under more manageable and cost-effective conditions while maintaining the desired crystal structure and coloristic properties.
Solution Approach 2:
The invention introduces an intermediary approach by using aqueous-phase chemical reactions with controlled pH and temperature conditions as a mediator to form the solid solution structure. This intermediary process avoids the need for extreme vacuum or inert gas atmospheres, simplifying the manufacturing process while still achieving the desired solid solution phase.
Data Source
AI summary
The present invention relates to a solid solution comprising (a) at least one compound according to formula (I), and (b) at least one compound according to formula (II), or at least one compound according to formula (III), or a mixture of at least one compound according to formula (II) and at least one compound according to formula (III), wherein R1 and R2 may, independently of one another, stand for —(CH2)n—X, wherein X stands for hydrogen, methyl, a C1-C5 alkoxyl, hydroxy, phenyl, C1-C5 alkylphenyl, C1-C5 alkoxyphenyl, hydroxyphenyl, halogenated phenyl, pyridyl, C1-C5 alkylpyridyl, C1-C5 alkoxypyridyl, halogenated pyridyl, pyridylvinyl or naphthyl; wherein n stands for 0, 1, 2, 3, 4 or 5; R3 and R4 may, independently of one another, stand for phenylene, C1-C5 alkylphenylene, C1-C5 alkoxyphenylene, hydroxyphenylene, halogenated phenylene, pyridinediyl, C1-C5 alkylpyridinediyl, C1-C5 alkoxy-pyridinediyl, halogenated pyridinediyl, anthraquinonediyl or naphthalenediyl, wherein the 2 nitrogen atoms bound to R3 according to formula (II) and (III) form a 5-membered or a 6-membered heterocycle with 2 atoms of an aromatic ring of R3; wherein the 2 nitrogen atoms bound to R4 according to formula (II) and (III) form a 5-membered or a 6-membered heterocycle with 2 atoms of an aromatic ring of R4; X1 to X8 may, independently from one another, stand for hydrogen, C1-C5 alkyl, C1-C5 alkoxy, hydroxy, phenyl or halide. The present invention further relates to a process for producing the solid solution. Furthermore, the present invention relates to a solid solution obtainable or obtained according to said process and to the use of the inventive solid solution, in particular as a NIR transparent black colorant in a NIR non-absorbing component.