Liquid Bisacylphosphine Oxide Photoinitiator Mixture
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Solution Overview
Problem
Current bisacylphosphine oxide photoinitiators are often solid, making them difficult to dissolve and incorporate into radiation curable formulations, requiring high temperatures and complex handling due to dust formation, and their liquid blends are unstable under varying environmental conditions, limiting their application and curing performance.
Innovation Solution
Development of a liquid bisacylphosphine oxide photoinitiator mixture through transesterification of bisacylphosphine oxide with alcohols, allowing for a simple and inexpensive process to produce a liquid form with improved stability and handling properties, enabling broader mixing ratios and enhanced curing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solid bisacylphosphine oxide photoinitiators are used, then curing performance is improved, but ease of operation deteriorates due to difficult dissolution and complex handling
Solution Approach 1:
The patent applies parameter changes by modifying the physical state of the photoinitiator from solid to liquid through chemical structure modification (introducing flexible alkyl chains or converting to esters). This fundamental parameter change resolves the contradiction by maintaining the high curing performance of BAPO compounds while eliminating the handling and dissolution difficulties associated with solid forms.
Solution Approach 2:
The patent creates composite photoinitiator systems by combining liquid BAPO derivatives with other photoinitiator types (such as alpha-hydroxy ketones or phosphinic acid esters). This composite approach allows the formulation to achieve both excellent curing performance (inherited from BAPO) and improved ease of operation (provided by the liquid state and better solubility of the composite system).
2Reliability
If solid bisacylphosphine oxide photoinitiators are used, then curing performance is improved, but manufacturing precision deteriorates due to inhomogeneous incorporation
Solution Approach 1:
By changing the physical state parameter from solid to liquid, the patent enables homogeneous mixing and precise incorporation into radiation curable formulations. The liquid state allows for uniform distribution at molecular level, eliminating the inhomogeneity problems associated with dissolving solid powders.
Solution Approach 2:
The patent uses liquid photoinitiator esters as intermediary compounds that facilitate homogeneous incorporation into formulations. These liquid intermediaries can be easily mixed with other formulation components before curing, ensuring uniform distribution and precise manufacturing control.
3Ease of operation
If liquid blends of photoinitiators are used, then ease of operation is improved, but stability deteriorates under varying environmental conditions
Solution Approach 1:
The patent develops liquid photoinitiator esters that are inherently stable in their liquid state without requiring complex stabilization measures. These compounds are designed to be used promptly in formulations, providing ease of operation while maintaining adequate stability during their service life.
Solution Approach 2:
The patent creates stable composite photoinitiator systems by combining liquid BAPO derivatives with complementary photoinitiator types. These composite formulations achieve both ease of operation (liquid state) and improved stability (through synergistic interactions and reduced crystallization tendency compared to pure solid components).
4Ease of operation
If liquid bisacylphosphine oxide photoinitiators are developed, then ease of operation is improved, but manufacturing complexity increases
Solution Approach 1:
The patent extracts the essential functional components (acylphosphine oxide core with liquidating substituents) to create simplified liquid photoinitiator molecules. This extraction approach produces compounds that are easier to handle while maintaining the core photoinitiating function, thereby improving ease of operation without proportionally increasing manufacturing complexity.
Solution Approach 2:
The patent applies parameter changes through targeted molecular modifications (adding flexible alkyl chains or converting to esters) that transition the compound from solid to liquid state. These parameter changes are achieved through relatively straightforward synthetic routes, improving ease of operation without excessive manufacturing complexity.
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 liquid bisacylphosphine oxide photoinitiator mixture provides a stable, easy-to-handle solution with improved curing performance and expanded mixing ratios, overcoming the challenges of solid forms and stability issues in existing technologies.
Implementation Method 1
The invention relates to a photopolymerizable composition comprising (A) at least one monomeric or oligomeric ethylenically unsaturated photopolymerizable compound, and (B) at least one liquid photoinitiator mixture
Data Source
AI summary
A photoinitiator mixture comprising the components (a) a compound of the Formula (I), wherein Ar1 and Ar2 independently of each other are Formula (IV) or naphthyl which is unsubstituted or substituted one or more times by R1, R2, R3 or R'; R1 and R3 independently of each other are C1-C4alkyl, C1-C4alkoxy or halogen; R2 is hydrogen, C1-C4alkyl, halogen, C1-C4alkoxy or C2-C20alkoxy which is interrupted by one or more O; Q is C1-C4alkylene; R4 is methyl or ethyl; R' and R" independently of each other are hydrogen or PG-Y-R'''-X-; PG is a polymerizable group or methyl or ethyl; Y is a direct bond, O or S; X is a direct bond, O or S; R''' is a direct bond, C1-C20alkylene or C2-C20alkylene which is interrupted by one or more O; (b) one or more compounds of the Formula (II), wherein Ar1, Ar2 and Q are as defined above, and R5 is for example C3-C30alkyl which is unsubstituted or substituted and (c) optionally a compound of the Formula (III), wherein R5 is as defined above; provides a liquid photoinitiator.