Grafted Phenoxy Resin Adhesive for Silicone Rubber Bonding
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Solution Overview
Problem
Existing adhesive systems face challenges in achieving robust bonding between silicone rubbers and rigid substrates, particularly plastics and metals, due to low surface energy and lack of functional groups, and are less effective for high-temperature LSRs and solvent-based formulations, with reproducibility issues in surface treatment methods like plasma treatment.
Innovation Solution
A curable adhesive composition based on a grafted phenoxy resin with carboxylic acid and acrylate-derived ester functionality, combined with organic carbonates, blocked isocyanates, and maleimide compounds, which enhances bonding through increased molecular weight, crosslink density, and hydrogen bonding capabilities, allowing for effective adhesion to a wide range of silicone rubbers and rigid substrates without the need for surface treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If surface treatment techniques (plasma, mechanical, chemical) are used to modify plastic surfaces, then adhesion to silicone is improved, but performance reproducibility deteriorates and covalent bonding capability is still insufficient
Solution Approach 1:
The invention changes the chemical parameters of the adhesive formulation by incorporating silane coupling agents and functional groups that can form covalent bonds with both the plastic substrate and silicone rubber. This chemical modification approach provides more consistent and reproducible bonding performance compared to physical surface treatment methods.
Solution Approach 2:
The adhesive composition uses a composite formulation combining silane coupling agents, functional resins, and other components that work synergistically to achieve both strong adhesion and covalent bonding capability while maintaining reproducible performance across different applications.
2Adaptability or versatility
If conventional adhesive formulations are used, then bonding to low-temperature LSR is effective, but bonding to high-temperature LSRs and solvent-based formulations deteriorates
Solution Approach 1:
The adhesive formulation is designed with multiple functional components including silane coupling agents, functional resins, and crosslinking agents that enable it to bond effectively to various types of silicone rubbers (low-temperature and high-temperature LSRs) and different substrates, providing universal applicability while maintaining consistent performance.
Solution Approach 2:
The invention modifies the adhesive's chemical composition parameters to include temperature-resistant functional groups and crosslinking mechanisms that maintain bonding effectiveness across a wide temperature range, enabling reliable adhesion to both low-temperature and high-temperature LSRs.
3Strength
If surface treatment is applied to plastic substrates, then wettability and adhesion are improved, but the process complexity and time increase
Solution Approach 1:
The adhesive acts as an intermediary chemical layer between the plastic substrate and silicone rubber, containing functional groups that bond to both materials. This eliminates the need for separate surface treatment steps, simplifying the overall process while maintaining strong adhesion.
Solution Approach 2:
The adhesive formulation is pre-designed with built-in surface activation capabilities through functional groups and silane coupling agents that can chemically interact with the plastic substrate without requiring preliminary surface treatment, thereby reducing process complexity and time.
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 adhesive system provides robust bonding across various silicone rubber and rigid substrate combinations, including high-temperature LSRs, and performs well in high humidity and heat environments, offering improved reproducibility and environmental performance compared to previous adhesive systems.
Implementation Method 1
A curable adhesive composition based on a grafted phenoxy resin with carboxylic acid and acrylate-derived ester functionality, combined with organic carbonates, blocked isocyanates, and maleimide compounds, which enhances bonding through increased molecular weight, crosslink density, and hydrogen bonding capabilities
Implementation Method 2
A curable adhesive composition based on a grafted phenoxy resin with carboxylic acid and acrylate-derived ester functionality, combined with organic carbonates, blocked isocyanates, and maleimide compounds, which enhances bonding through increased molecular weight, crosslink density
Data Source
AI summary
A curable adhesive that is particularly well suited for use in an injection or compression molding operation. The adhesive is based on polymeric resins having carboxylic acid and acrylate ester functionality, such as grafted phenoxy resin, and further constituents such as organic carbonates, blocked isocyanates, catalysts, maleimide compounds, hydride sources, and a carrier fluid. The curable adhesives are particularly well suited for bonding liquid injectable substrates such as liquid silicone rubber, or polyamides to rigid substrates, such as aluminum, stainless steel, or glass.