Bonding Primer Composition for Uniform Metal Adhesive Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bonding primers struggle with non-uniform thickness application on large metal surfaces, leading to reduced adhesive strength and increased corrosion, particularly at low temperatures, and lack sufficient toughness to maintain performance across varying thicknesses.
Innovation Solution
A solvent-based bonding primer composition containing epoxy resins, core-shell rubber particles, and silane compounds, applied via spray or brush, forms a uniform film that enhances adhesion and toughness, maintaining strength at low temperatures and resisting corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a primer layer is applied by spraying using a spray nozzle onto the surface of a large metal section, then the primer can be applied to large surfaces, but the thickness of the primer layer is not uniform across the large surface area being sprayed
Solution Approach 1:
The patent modifies the primer composition by incorporating core-shell rubber particles with specific size distributions (D10: 0.01-10 μm, D50: 0.1-100 μm, D90: 0.1-1000 μm) and controlled shell thickness (1-50 nm), which changes the rheological and adhesive parameters of the primer formulation. This enables the primer to achieve uniform thickness distribution across large surfaces while maintaining optimal bonding performance.
Solution Approach 2:
The patent creates a composite primer system combining epoxy resins, curing agents, silane compounds, and core-shell rubber particles. The core-shell rubber particles act as toughening agents that distribute uniformly throughout the primer matrix, providing both thickness tolerance and enhanced adhesion to varyingsurface conditions.
2Quantity of substance
If the primer thickness exceeds about 0.25 mil (6.4 μm), then more primer can be applied to ensure coverage, but peel strength at low temperatures drops significantly
Solution Approach 1:
The patent changes the compositional parameters of the primer by incorporating core-shell rubber particles with specific size distributions and shell thickness ratios. This modifies the primer's mechanical properties to achieve thickness tolerance, allowing application at 0.3 mil or above while maintaining peel strength at low temperatures through the toughening effect of the rubber particles.
Solution Approach 2:
The composite primer formulation with core-shell rubber particles provides toughness that enables the primer to withstand thickness variations without sacrificing low-temperature peel strength. The core-shell structure provides both adhesion and flexibility needed for thick applications.
3Strength
If any toughening material is added to the primer composition to enhance toughening efficiency, then peel strength improves, but the material must be compatible with or work synergistically with the primer chemistry without negatively affecting the primer's overall performance
Solution Approach 1:
The patent specifies precise compositional parameters for the primer formulation, including the type and amount of epoxy resin, curing agent, and silane compound, to ensure chemical compatibility with the core-shell rubber particles. The shell thickness of the rubber particles (1-50 nm) is optimized to provide toughening while maintaining compatibility with the primer chemistry.
Solution Approach 2:
The patent develops a synergistic composite system where core-shell rubber particles are integrated with epoxy resins, curing agents, and silane compounds. The core-shell structure provides toughness while the shell material ensures chemical compatibility with the primer formulation, achieving both peel strength improvement and overall performance maintenance.
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 primer composition achieves high peel strength and corrosion resistance, even at 0.3 mil thickness, with improved film uniformity and stability, ensuring robust bonding performance across temperature variations.
Implementation Method 1
an improved primer thickness tolerance requires further toughening efficiency in the polymer networks of the cured primer layer
Implementation Method 2
containing: one or more epoxy resins, curing agent(s), a silane compound
Implementation Method 3
containing: one or more epoxy resins, curing agent(s)
Data Source
AI summary
Disclosed herein is a solvent-based bonding primer composition containing one or more organic solvents, one or more epoxy resins, one or more curing agents, a silane compound, and a low amount of core-shell rubber particles in nanometer size, submicron or micron size. Also disclosed is a method of applying the solvent-based bonding primer composition onto a metallic surface of a first substrate prior to bonding the metallic surface to a second substrate via a curable adhesive.