Benzoylformic Acid Amide Photoinitiator for Low-Yellowing UV-LED Curing
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Solution Overview
Problem
Existing photopolymerization initiators using intramolecular cleavage-type and hydrogen abstraction-type photopolymerization initiators face issues such as low safety, odor generation, yellowing, and inefficiency, particularly when used with long-wavelength UV-LED lamps, leading to durability and compatibility problems in various applications.
Innovation Solution
A benzoylformic acid amide derivative with specific substituents and structures, capable of functioning as a photopolymerization initiator and photosensitizer, exhibits high photopolymerization initiation ability and photosensitivity, minimizing decomposed products and yellowing, even without additional additives, and ensuring high compatibility and durability in cured products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If intramolecular cleavage-type photopolymerization initiators are used, then photopolymerization initiation ability is improved, but decomposed products remain in cured products causing deterioration in durability, odor generation, and coloring over time
Solution Approach 1:
The patent extracts and eliminates the harmful decomposed products by switching from intramolecular cleavage-type initiators to hydrogen abstraction-type initiators. This type of initiator generates radicals through hydrogen abstraction from donors without producing decomposed products that remain in the cured product, thereby removing the source of durability deterioration, odor, and yellowing.
Solution Approach 2:
The patent converts the previously harmful decomposed products into beneficial outcomes by using hydrogen abstraction-type initiators. Instead of producing harmful decomposed products, the initiators generate radicals through hydrogen abstraction, which are the desired active species for polymerization without leaving harmful residues.
2Reliability
If hydrogen abstraction-type photopolymerization initiators are used, then decomposed products are eliminated, but photopolymerization initiation efficiency is low
Solution Approach 1:
The patent changes the chemical parameters of the initiator system by combining hydrogen abstraction-type initiators with specific hydrogen donors and photosensitizers. This parameter change optimizes the hydrogen abstraction process to achieve both high initiation efficiency and high purity cured products, resolving the contradiction between efficiency and purity.
3Object-affected harmful factors
If conventional photopolymerization initiators are used with long-wavelength UV-LED lamps, then safety is improved, but photopolymerization initiation effect and photosensitive effect are low and cured products are easily yellowed
Solution Approach 1:
The patent changes the spectral parameters by developing initiators and photosensitizers specifically active in the long-wavelength UV region (360-420 nm) emitted by LED lamps. This parameter optimization enables efficient photopolymerization initiation with safe long-wavelength UV light, achieving both high safety and high initiation effect simultaneously.
Solution Approach 2:
The patent creates composite initiator systems combining hydrogen abstraction-type initiators with specific hydrogen donors and photosensitizers that are optimized for long-wavelength UV light. This composite approach enhances the photosensitive effect and prevents yellowing while maintaining safety, resolving the contradiction between safety and initiation effectiveness.
4Productivity
If conventional photopolymerization initiators are used, then curing is achieved, but cured products show yellowing over time and poor durability
Solution Approach 1:
The patent extracts and eliminates the root cause of yellowing and durability issues by using hydrogen abstraction-type initiators that do not produce decomposed products. This eliminates the chemical basis for yellowing and improves long-term durability while maintaining effective curing capability.
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 benzoylformic acid amide derivative achieves efficient curing with low energy and short curing times, reducing odor, yellowing, and bleed-out, enhancing safety and durability in compositions like ink-jet inks, adhesives, and dental materials, while maintaining high adhesion and transparency.
Implementation Method 1
Photopolymerization and photocuring with active energy rays including ultraviolet light (UV) generally mean that photopolymerization initiator-containing compositions are irradiated with UV to generate active species such as radicals or ions, resulting in the occurrence of polymerization reaction
Implementation Method 2
the photopolymerization initiation effect and the photosensitive effect are low and cured products obtained are easily yellowed... high in photopolymerization initiation ability with active energy rays, in particular, light beams at 360 to 420 nm radiated from an LED lamp
Data Source
AI summary
A benzoylformic acid amide derivative is provided that has photopolymerization initiation properties and photosensitization effect with respect to long-wavelength ultraviolet light, and a cured product obtained from a curable composition that contains the benzoylformic acid amide derivative has an extremely low content of a low molecular weight component, and has high yellowing resistance, durability and safety.