Acylphosphine Oxide Photoinitiators for Low-Migration Ink Jet Curing
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Solution Overview
Problem
Existing photopolymerization initiators migrate excessively from cured substances, affecting curing sensitivity and ink jet jettability, and degrade preservation stability in polymerizable compositions.
Innovation Solution
Development of acylphosphine oxide compounds with specific structural features, such as a carbonyloxy methyl structure in the meta position and polyvalent linking groups, to minimize migration and enhance curing sensitivity and ink jet jettability while maintaining preservation stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional photopolymerization initiators are used, then curing sensitivity is improved, but migration from cured substance increases excessively
Solution Approach 1:
The patent modifies the molecular weight parameter of the photopolymerization initiator by using high-molecular-weight compounds (Mw ≥ 1,000) with specific acylphosphine oxide structures. This parameter change reduces migration while maintaining curing sensitivity, as the larger molecular size limits diffusion from the cured substance.
Solution Approach 2:
The patent employs composite molecular structures combining acylphosphine oxide functional groups with high-molecular-weight backbones or core structures. This composite approach integrates the photopolymerization activity of acylphosphine oxide with the low-migration characteristics of high-molecular-weight compounds.
2Reliability
If conventional photopolymerization initiators are used, then curing sensitivity is improved, but ink jet jettability deteriorates
Solution Approach 1:
The patent optimizes the molecular weight parameter within a specific range (Mw ≥ 1,000) to balance curing sensitivity and ink jet jettability. This parameter adjustment ensures the initiator remains sufficiently small for jetting while large enough to reduce migration and maintain curing performance.
Solution Approach 2:
The patent introduces specific local structural features (acylphosphine oxide groups) at strategic positions within the high-molecular-weight structure. These localized functional groups provide curing sensitivity while the overall molecular architecture ensures proper flow characteristics for ink jet application.
3Reliability
If photopolymerization initiator concentration is increased, then curing sensitivity is improved, but preservation stability deteriorates
Solution Approach 1:
The patent changes the molecular weight parameter to high values (Mw ≥ 1,000), which reduces the required concentration of photopolymerization initiator for achieving effective curing. This lower concentration requirement improves preservation stability while maintaining curing sensitivity through the high efficiency of the acylphosphine oxide structure.
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 acylphosphine oxide compounds exhibit reduced migration, improved curing sensitivity, and enhanced ink jet jettability, along with superior preservation stability in polymerizable compositions.
Implementation Method 1
acylphosphine oxide compounds that generate a polymerization initiating species by irradiation with active radiation such as ultraviolet rays
Data Source
AI summary
A photopolymerization initiator is an acylphosphine oxide compound represented by Formula 1-1 or Formula 2-1. A polymerizable composition or an ink jet recording method is a polymerizable composition or an ink jet recording method in which the photopolymerization initiator is used. In addition, an acylphosphine oxide compound represented by Formula 1-1 or Formula 2-1 which can be preferably used as the photopolymerization initiator. In Formula 1-1 and Formula 2-1, A represents an m-valent group, L's each independently represent a single bond or a divalent linking group, R1's each independently represent an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, R2 and R3 each independently represent an alkyl group, an aryl group, or an alkoxy group, m represents an integer of 3 or more, n1's each independently represent an integer of 0 to 4, and n2's each independently represent an integer of 0 to 5.