Crosslinkable Composition Using Visible Light Absorbing Compounds
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Solution Overview
Problem
Materials vulnerable to ultraviolet rays, such as those in optical applications, are less suitable for UV radiation curing, posing challenges in bonding with adhesives that require UV curing or post-curing.
Innovation Solution
A crosslinkable composition comprising a (meth)acrylate polymer and a visible light absorbing compound, which can be crosslinked using visible light radiation without requiring unsaturation functionality in the polymer, allowing for the use of visible light initiators to trigger crosslinking, and a method involving multiple radiation steps with different wavelengths to achieve crosslinking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If UV radiation curing is used, then curing speed and efficiency are improved, but materials vulnerable to UV rays cannot be bonded
Solution Approach 1:
The patent changes the wavelength parameter of the radiation from ultraviolet (UV) to visible light range (400-700 nm). This parameter change allows the curing process to be applied to materials that are sensitive to UV radiation while maintaining efficient crosslinking through the use of visible light-absorbing compounds as photoinitiators.
Solution Approach 2:
The patent introduces visible light-absorbing compounds as intermediary substances that absorb visible light radiation and transfer the energy to initiate crosslinking of the polymer. These compounds act as mediators between the visible light source and the polymer matrix, enabling curing without direct UV exposure to sensitive materials.
2Object-affected harmful factors
If visible light radiation is used, then safety and cost are improved, but crosslinking efficiency may be reduced
Solution Approach 1:
The patent optimizes the wavelength parameters of visible light radiation (400-700 nm) to match the absorption spectra of the visible light-absorbing compounds. This parameter optimization ensures efficient energy transfer and crosslinking initiation while maintaining the safety advantages of visible light over UV radiation.
Solution Approach 2:
The patent uses visible light-absorbing compounds that replicate the function of UV photoinitiators but operate in the visible spectrum. These compounds copy the photoinitiation mechanism while operating at safer, longer wavelengths, thereby maintaining crosslinking efficiency without the harmful effects of UV radiation.
3Adaptability or versatility
If visible light radiation is used, then applicability to semi- to non-transparent materials is improved, but radiation penetration depth may be limited
Solution Approach 1:
The patent employs visible light-absorbing compounds that are distributed throughout the polymer composition, creating localized crosslinking sites. This local quality approach allows crosslinking to occur throughout the material volume even when visible light penetration is limited, enabling effective curing of semi- to non-transparent materials.
Solution Approach 2:
The visible light-absorbing compounds are pre-distributed within the polymer composition before curing. This preliminary distribution ensures that when visible light radiation is applied, crosslinking can initiate at multiple locations throughout the material, compensating for limited penetration depth and enabling uniform curing of opaque materials.
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 effective crosslinking of polymers, including pressure-sensitive adhesives, with visible light, offering advantages in safety, cost, and applicability to semi- to non-transparent materials, while maintaining the safety and efficiency of visible light radiation.
Implementation Method 1
A crosslinkable composition comprising a (meth)acrylate polymer and a visible light absorbing compound, which can be crosslinked using visible light radiation
Implementation Method 2
a visible light absorbing compound of one of the following formulae (I), (II), or (III)... subjecting the crosslinkable composition to radiation having a wavelength of 400 nm or greater
Data Source
AI summary
The present disclosure provides a crosslinkable composition including a (meth)acrylate polymer and a visible light absorbing compound. Two percent or less of the carbon-carbon bonds in the crosslinkable composition are double bonds. The composition allows for inclusion of one or more materials degradable by ultraviolet radiation and/or stabilized against ultraviolet radiation. Methods for making a crosslinked composition is also provided. One method includes obtaining a crosslinkable composition and subjecting the crosslinkable composition to radiation having a wavelength of 400 nm or greater. Another method includes subjecting a crosslinkable composition to first and second radiations that are different from each other.