Reactive Adhesive Tape Production via Multi-Screw Extrusion
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Solution Overview
Problem
Existing methods for processing pressure-sensitive adhesives based on non-thermoplastic elastomers, such as nitrile rubber, face challenges in achieving high bond strengths and large layer thicknesses without adverse effects on the adhesive's properties, particularly due to issues with early crosslinking and molecular weight reduction during processing.
Innovation Solution
A method using a multi-screw extruder to digest non-thermoplastic elastomers with reactive epoxy resins, allowing for the production of homogeneous, thermoplastic adhesives that can form thick films with high bond strengths, while maintaining storage stability and processability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If non-thermoplastic elastomers are processed from solution to produce adhesive tapes, then the adhesive can be applied and dried, but the films can only have limited thicknesses
Solution Approach 1:
The patent changes the processing parameters by transitioning from solution-based processing to melt processing. This involves heating the adhesive composition to temperatures above the melting point of the thermoplastic polymer (e.g., 60-200°C) to create a processable melt state, enabling the formation of thick adhesive layers without solvent restrictions
Solution Approach 2:
The patent utilizes phase transition of the thermoplastic polymer from solid to liquid state through heating. The adhesive composition is heated to melt the thermoplastic polymer, allowing it to be processed into thick layers, then cooled to solidify and form the final adhesive tape structure
2Strength
If reactive adhesives are used to achieve very high bond strengths, then the bonding forces increase, but the components are in liquid form and are difficult to use for adhesive tapes
Solution Approach 1:
The patent creates a composite adhesive system combining thermoplastic polymer (for processability and tape formation) with reactive adhesive components (for high bond strength). The thermoplastic matrix provides structural integrity and ease of handling, while the reactive components embedded within deliver high bonding performance when activated
Solution Approach 2:
The thermoplastic polymer acts as an intermediary carrier that enables the reactive adhesive components to be handled in solid tape form rather than liquid. The thermoplastic matrix allows the reactive components to be transported and applied easily, then releases them to function when needed
3Volume of moving object
If adhesive layers of higher thickness are produced to compensate for substrate distances, then the bond strength is maintained, but the processing from melt requires the polymer systems to be thermoplastic
Solution Approach 1:
The patent makes the adhesive composition universally processable by melt processing through the addition of thermoplastic polymer. This single formulation approach works for producing adhesive tapes of various thicknesses and can be processed using standard extrusion and lamination equipment, eliminating the need for different processing methods for different thickness requirements
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 the production of pressure-sensitive adhesives with high bond strengths and large layer thicknesses, maintaining storage stability and processability, by converting non-thermoplastic elastomers into thermoplastic adhesives through controlled digestion with epoxy resins in a multi-screw extruder.
Implementation Method 1
digest non-thermoplastic elastomers with reactive epoxy resins
Implementation Method 2
digest non-thermoplastic elastomers with reactive epoxy resins
Implementation Method 3
react with one another to form chemical bonds
Data Source
Figure 1
AI summary
A method for producing pressure-sensitive adhesives comprising at least one elastomer component and at least one reactive adhesive comprising one or more reactive resins, of which at least one reactive resin is an epoxy resin, and at least one hardener for epoxy resins, starting from one or more non-thermoplastic elastomers, characterized in that the non-thermoplastic elastomers are processed with at least one part of the epoxy resins in a multi-screw extruder having at least six axially parallel, co-rotating screw shafts arranged in a circle.