Anthraquinone NIR Absorbers for Colorless Stable Optical Filters
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Solution Overview
Problem
There is a need for almost colorless NIR absorbers with high chemical and thermal stability for applications such as laser writing, heat shielding, security printing, and laser-welding of plastics, which existing anthraquinone dyes do not adequately address.
Innovation Solution
Development of anthraquinone-based compounds of formula (I) with specific substituents that provide high resistance to chemicals and solvents, good light stability, and thermal stability, suitable for use as IR absorbers in various applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing anthraquinone dyes are used for IR absorption, then IR absorption capability is provided, but colorless appearance and stability are insufficient
Solution Approach 1:
The patent modifies the chemical structure of anthraquinone dyes by introducing specific substituent groups (Y1-Y4 being O, NR13, or combinations thereof) and varying R1-R10 substituents to achieve the desired balance of colorless appearance, IR absorption, and stability. This structural parameter optimization resolves the contradiction by creating new dye variants that meet all requirements.
Solution Approach 2:
The invention creates composite molecular structures combining anthraquinone core with specific substituent patterns (including oxygen-containing and nitrogen-containing groups) to achieve synergistic effects. The composite structure provides both the colorless property and enhanced stability simultaneously, resolving the contradiction between availability and performance.
2Reliability
If compounds with high chemical resistance are developed, then resistance to chemicals and solvents is improved, but formulation compatibility may be reduced
Solution Approach 1:
The patent applies different substituent types at specific positions (Y1-Y4 and R1-R10) to create localized functional regions. The core structure provides chemical resistance while peripheral substituents ensure formulation compatibility. This local differentiation resolves the contradiction by assigning different properties to different parts of the molecule.
Solution Approach 2:
The anthraquinone core structure serves multiple functions simultaneously: providing IR absorption, maintaining colorless appearance, ensuring chemical resistance, and enabling formulation compatibility through appropriate substituent selection. This multi-functionality resolves the contradiction between resistance and versatility.
3Temperature
If compounds with high thermal stability are synthesized, then thermal stability is improved, but application range may be limited
Solution Approach 1:
The patent optimizes thermal stability parameters by selecting specific substituent combinations (R1-R10 groups including alkyl, aryl, and heteroatomic substitutions) that enhance thermal resistance without compromising other properties. The structured parameter variation allows tuning for different application requirements while maintaining core stability.
Solution Approach 2:
The compounds are designed to serve multiple applications (security printing, laser welding, heat shielding, marker for liquids) simultaneously. The universal anthraquinone structure with optimized substituents provides thermal stability applicable across diverse uses, resolving the contradiction between stability and application range.
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 compounds exhibit excellent fastness to chemicals, light, and heat, with high compatibility in formulations, making them suitable for security printing, brand protection, and laser-welding of plastics, while also serving as markers for liquids and providing IR absorption in the 680 to 1000 nm range.
Implementation Method 1
IR absorbers for laser writing, heat shielding... absorbing light comprising a wavelength of 680 to 1000 nm
Data Source
AI summary
The present invention relates to compounds of the formula (I′), especially compounds of formula (I), a process for their preparation and their use as almost colourless IR absorbers, for optical filter applications, especially for plasma display panels, or for laser welding of plastics. The compounds may be used in compositions for inks, paints and plastics, especially in a wide variety of printing systems and are particularly well-suited for security applications, or for brand protection; or as marker for liquid. Compounds of formula (I′), especially compounds of formula (I), represent almost colourless IR absorbers, which exhibit high resistance against chemicals and solvents as well as good light stability and good thermal stability. Due to their unique application properties they can be advantageously employed as IR absorbers for laser writing, heat shielding, security printing, the laser-welding of plastics and as marker for liquids.