Polymer-Containing Cyclic Olefin Adhesives with Latent ROMP Catalysts
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Solution Overview
Problem
Existing adhesive compositions lack the ability to effectively bond substrates with high initial adhesion and structural bond strength, particularly when using cyclic olefins that require ring-opening metathesis polymerization (ROMP) due to the challenges of catalyst latency and activation.
Innovation Solution
Adhesive compositions comprising at least 20 wt.% polymer, unpolymerized cyclic olefins, and latent ring-opening metathesis polymerization catalysts or precatalysts, which are activated through actinic radiation or thermal means, allowing for controlled polymerization and enhanced bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If ring-opening metathesis polymerization (ROMP) is used to polymerize cyclic olefins, then structural bond strength is improved, but catalyst latency and activation challenges worsen
Solution Approach 1:
The patent employs a latent catalyst system that acts as an intermediary between the cyclic olefin monomers and the active polymerization catalyst. The latent catalyst remains inactive during storage and application but activates upon contact with moisture or heat, enabling ROMP polymerization without requiring complex external activation equipment. This resolves the contradiction by providing structural bond strength through ROMP while simplifying catalyst management.
Solution Approach 2:
The patent incorporates the latent catalyst and cyclic olefin in a pre-formulated adhesive composition before application. The catalyst is prepared in a latent state that can be stored stably, and upon application to the substrate, it automatically activates to initiate polymerization. This preliminary preparation eliminates the need for complex post-application catalyst activation procedures.
2Strength
If high polymer content (at least 20 wt.%) is used in the adhesive composition, then initial adhesion is improved, but control over polymerization process becomes more difficult
Solution Approach 1:
The patent carefully controls the parameters of the adhesive composition, including the specific weight percentage of polymer (at least 20 wt.%), the type of latent catalyst, and the composition of the cyclic olefin. By optimizing these parameters, the patent achieves high initial adhesion while maintaining controllable polymerization through the latent catalyst system that activates under specific conditions (moisture or heat) rather than spontaneously.
3Strength
If cyclic olefins are used as polymerizable monomers, then structural bond strength is improved, but ease of manufacture and handling worsen due to ROMP requirements
Solution Approach 1:
The latent catalyst serves as an intermediary that enables the use of cyclic olefins without requiring complex manufacturing infrastructure. The cyclic olefin and latent catalyst can be mixed and stored together in a stable composition, eliminating the need for separate catalyst preparation and activation equipment at the manufacturing site. This maintains ease of manufacture while enabling ROMP polymerization for structural bond strength.
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 compositions provide high initial adhesion and structural bond strength by ensuring controlled polymerization of cyclic olefins, resulting in robust adhesive articles suitable for various substrates.
Implementation Method 1
unpolymerized cyclic olefin; and a latent ring opening metathesis polymerization catalyst or precatalyst thereof
Implementation Method 2
the catalyst or precatalyst thereof is activatable with actinic radiation
Data Source
AI summary
Adhesive composition and articles are described comprising a carrier substrate (e.g. release liner or backing) and an adhesive composition disposed on the carrier substrate. The adhesive composition comprises at least 20 wt. % of a polymer; unpolymerized cyclic olefin; and a (e.g. latent) ring opening metathesis polymerization catalyst or precatalyst thereof. The polymer may have a Tg less than 25° C. and/or may be an acrylic polymer. Also described is a method of bonding.