Cationically Curable Composition With Two-Stage Strength Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cationically curable compositions suffer from slow buildup of strength and insufficient handling strength after joining, requiring long waiting periods or additional fixing aids, and lack methods for precise control of strength development in industrial processes.
Innovation Solution
A cationically curable composition comprising two photoinitiators activated by different wavelengths, where a first photoinitiator is activated by a first wavelength to initiate polymerization and allow alignment of substrates, followed by activation of a second photoinitiator with a shorter wavelength to fix the composition, enabling controlled strength buildup without additional heat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If basic retardants are added to cationically curable compositions to extend working time, then the composition remains workable longer, but the buildup of strength occurs slowly and handling strength after joining is insufficient
Solution Approach 1:
The patent divides the photoinitiation process into two distinct stages using two different photoinitiators with different absorption characteristics. The first photoinitiator (activated by λ1) provides initial polymerization and working time, while the second photoinitiator (activated by λ2) delivers rapid strength buildup. This segmentation allows independent optimization of each stage's properties.
Solution Approach 2:
The first photoinitiator performs preliminary polymerization action that establishes the base structure and provides sufficient working time for joining operations. This preliminary action prepares the system for the subsequent rapid strengthening phase without requiring basic retardants.
2Device complexity
If single wavelength irradiation is used to activate photoinitiators, then the process is simple, but precise control of strength development at different stages is not achieved
Solution Approach 1:
The patent applies different wavelengths (different qualities of energy) to different stages of the curing process. The first wavelength λ1 is optimized for initiating polymerization and providing working time, while the second wavelength λ2 is optimized for rapid strength buildup. Each wavelength provides the specific quality needed for its stage.
Solution Approach 2:
The patent changes the irradiation parameter (wavelength) between two distinct stages. By switching from wavelength λ1 to wavelength λ2, the system transitions from the working time phase to the rapid curing phase, enabling precise control over strength development kinetics.
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
Enables rapid and controlled curing at room temperature, allowing precise alignment and handling of joined parts, with the potential for accelerated curing through heating, and suitable for diverse industrial applications including optoelectronic components.
Implementation Method 1
a first photoinitiator (B1) which releases an acid upon irradiation with actinic radiation of a first wavelength λ1
Implementation Method 2
a second photoinitiator (B2), which is different from the first photoinitiator (B1) and releases an acid upon irradiation with actinic radiation of a second wavelength λ2
Data Source
AI summary
The invention relates to a cationically curable composition with at least one cationically polymerizable component, a first photoinitiator releasing an acid when irradiated with actinic radiation of a first wavelength λ1, and a second photoinitiator releasing an acid when irradiated with actinic radiation of a second wavelength λ2, wherein the second wavelength λ2 is shorter than the first wavelength λ1, and wherein the second photoinitiator, after irradiation of the composition with actinic radiation of the first wavelength λ1, shows an absorption of actinic radiation of the second wavelength λ2 in the composition that is sufficient to activate the second photoinitiator and fix the composition. Furthermore, a method is described for the joining, casting, molding, sealing and/or coating of substrates using the cationically curable composition.