Squarylium Compound Infrared Cut Filter for Visible Transparency
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Solution Overview
Problem
Existing infrared cut filters struggle to achieve both excellent infrared shielding properties and visible transparency simultaneously, as described in prior art, particularly with squarylium compounds.
Innovation Solution
A near-infrared absorbing composition comprising a squarylium compound with an absorption maximum of 700 nm or longer, combined with a resin, which enhances infrared shielding while maintaining visible transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional squarylium compounds are used as infrared cut filters, then infrared shielding properties are improved, but visible transparency deteriorates
Solution Approach 1:
The patent modifies the molecular structure of squarylium compounds by introducing specific substituents (Ar1 and Ar2 divalent conjugated groups with heteroaryl rings containing chalcogen atoms) to shift the absorption maximum to 700 nm or longer. This parameter change in the chemical structure enables the compound to absorb infrared light while maintaining visible transparency, resolving the contradiction between infrared shielding and visible light transmission.
Solution Approach 2:
The patent creates a composite system by combining the specially designed squarylium compound with a resin to form a near-infrared absorbing composition. This composite material approach allows the squarylium compound to provide infrared shielding functionality while the resin matrix maintains the overall structural integrity and optical properties, achieving both infrared blocking and visible transparency simultaneously.
2Object-affected harmful factors
If the absorption maximum of squarylium compound is shifted to longer wavelengths, then infrared shielding is improved, but the compound becomes more difficult to manufacture
Solution Approach 1:
The patent systematically adjusts molecular parameters by selecting specific divalent conjugated groups (Ar1 and Ar2) containing heteroaryl rings with chalcogen atoms at defined positions. These controlled parameter changes in the molecular structure enable tuning of the absorption maximum to 700 nm or longer while maintaining synthetic feasibility through well-established organic chemistry methods for constructing these conjugated systems.
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 enables the manufacture of films and infrared cut filters with improved infrared shielding and visible transparency, suitable for solid image pickup elements, by adjusting the squarylium compound's absorption maximum and incorporating a resin.
Implementation Method 1
a squarylium compound represented by the following Formula (1) and having an absorption maximum of 700 nm or longer
Data Source
AI summary
A near infrared absorbing composition includes: a squarylium compound represented by the following Formula (1) and having an absorption maximum of 700 nm or longer; and a resin. In Formula (1), Ar1 and Ar2 each independently represent a divalent conjugated group which has a heteroaryl ring having a chalcogen atom, and R1 to R4 each independently represent a hydrogen atom or a substituent. The film and the infrared cut filter are formed of the near infrared absorbing composition. The solid image pickup element includes the infrared cut filter.