PC/ABS Composite Cover Layer Bonding After Climate Aging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing composite materials for automotive parts face issues with adhesion deterioration between polycarbonate-containing compositions and polyurethane layers after aging, particularly under climate conditions, and there is a need for lighter weight, uniformly colored, and durably adhered multi-layer articles with improved adhesion properties.
Innovation Solution
A polymeric composition comprising polycarbonate and a toughening component, such as styrene acrylonitrile copolymer and impact modifier, is used to form a substrate layer that maintains strong adhesion to a polyurethane or polyurea cover layer, even after aging, with a weight ratio of polycarbonate to toughening component of 55:45 or less, and optional reinforcing fillers like glass fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If polycarbonate-containing compositions are used as substrate layer, then weight is reduced compared to PMMA, but adhesion to polyurethane layer deteriorates after aging
Solution Approach 1:
The patent changes the chemical composition parameters of the substrate layer by incorporating specific amounts of polycarbonate (20-55 wt%), styrene-acrylonitrile copolymer (45-70 wt%), and impact modifier (10-30 wt%). This parameter optimization resolves the contradiction by achieving both weight reduction and adhesion durability through the synergistic effect of these components
Solution Approach 2:
The patent creates a composite substrate layer combining polycarbonate, styrene-acrylonitrile copolymer, and impact modifier. This composite material approach resolves the contradiction by integrating multiple materials that collectively provide both the weight reduction benefits of polycarbonate and the adhesion durability required for long-term reliability
2Reliability
If polycarbonate concentration in substrate layer is increased, then adhesion to polyurethane layer is improved, but weight reduction benefit is diminished
Solution Approach 1:
The patent optimizes the polycarbonate concentration parameter to a specific range (20-55 wt%) rather than using high concentrations. This parameter change achieves the balance between adhesion strength and weight reduction by finding the optimal point where sufficient adhesion is obtained without excessive polycarbonate content
Solution Approach 2:
The patent uses a composite material system where polycarbonate is combined with styrene-acrylonitrile copolymer and impact modifier. This composite approach allows the substrate to achieve good adhesion through the synergistic interaction of components while maintaining overall low density and weight reduction benefits
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 composition ensures initial adhesion of 4.0 MPa or more and durable adhesion of 3.7 MPa or more after aging tests, providing strong and long-lasting bonding between layers while reducing material density and thickness.
Implementation Method 1
injecting a polymerizable composition into a mold for filling a gap over a surface of the substrate layer and at least partially polymerizing the polymerizable composition for forming a polyurethane and/or a polyurea
Data Source
AI summary
The teachings herein are directed to multi-layered articles, methods for making the multi-layered articles, and polymeric compositions for the multi-layered articles. The multi-layered article includes a substrate layer and an overmolded cover layer. The substrate layer preferably is a polymeric composition including about 55 weight percent or less (preferably about 50 weight percent or less) polycarbonate, a styrene containing polymer, and an impact modifier. The cover layer preferably includes a polyurethane, a polyurea, or both. The substrate preferably forms a durable bond to the cover layer that maintains adhesion even after aging (e.g., heat, thermal cycling, UV light, visible light, humidity, climate aging, or any combination thereof).