Low Gloss Polymer Compositions for Automotive Interiors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current polymer compositions used for automotive interior parts, such as door panels and instrument panels, face challenges in achieving low gloss and high scratch resistance without the use of polyurethane coatings, which have high VOC emissions and interfere with grain pattern replication, and alternative blends of elastomers and polyolefins like polypropylene often result in high gloss and low scratch resistance.
Innovation Solution
A polymer composition comprising an ethylene/α-olefin multi-block interpolymer, a polypropylene with a tan delta value less than 2.5, and a polysiloxane, which meets specific characteristics such as molecular weight ratio, melting point, density, and elastic recovery to achieve low gloss and improved scratch resistance without the need for polyurethane coatings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyurethane coatings are used to reduce gloss and increase scratch resistance, then scratch resistance is improved, but VOC emissions increase and grain pattern replication is interfered with
Solution Approach 1:
The patent extracts and eliminates the polyurethane coating layer from the system, achieving low gloss and scratch resistance through the polymer composition itself rather than through a separate coating layer, thereby removing the source of VOC emissions while maintaining the desired surface properties
Solution Approach 2:
The polymer composition simultaneously provides both the base material properties and the surface properties (low gloss and scratch resistance) that were previously required from a separate polyurethane coating, making the coating unnecessary and enabling grain pattern replication
2Object-generated harmful factors
If alternative polymer blends of elastomers and polyolefins are used to avoid PU coatings, then VOC emissions are reduced, but gloss increases and scratch resistance decreases
Solution Approach 1:
The patent changes the chemical and physical parameters of the polymer composition, specifically incorporating silane-modified polyethylene and controlled amounts of polypropylene and elastomer, along with peroxide crosslinking, to achieve the desired low gloss surface without requiring PU coatings
Solution Approach 2:
The patent creates a composite polymer composition combining silane-modified polyethylene, polypropylene, and elastomer with peroxide crosslinking, where the interaction between these components produces the low gloss surface property that neither component alone could achieve
3Object-generated harmful factors
If alternative polymer blends of elastomers and polyolefins are used to avoid PU coatings, then VOC emissions are reduced, but scratch resistance decreases
Solution Approach 1:
The patent changes the chemical structure and crosslinking parameters of the polymer composition by incorporating silane-modified polyethylene and using peroxide crosslinking, which enhances scratch resistance while maintaining the absence of VOC-emitting coatings
Solution Approach 2:
The patent creates a composite polymer composition where the combination of silane-modified polyethylene, polypropylene, elastomer, and peroxide crosslinking produces synergistic effects that simultaneously achieve low gloss and high scratch resistance without PU coatings
4Ease of manufacture
If conventional extruded sheets are used for automotive interior parts, then production is simplified, but post-thermoformed gloss is high and scratch resistance is low
Solution Approach 1:
The patent changes the chemical composition parameters of the extruded sheet by using silane-modified polyethylene with specific molecular weight ratios and incorporating controlled amounts of polypropylene and elastomer, which results in low post-thermoformed gloss while maintaining ease of extrusion and thermoforming
Data Source
Figure 1
Figure 2
Figure 3
AI summary
This invention relates to polymer compositions comprising at least one ethylene/a-olefin interpolymer and a branched and/or high melt strength polypropylene, methods of making the polymer compositions, and molded, overmolded, extruded into profiles or thermoformed products made from the polymer compositions. The polymer compositions may have reduced post-thermoformed sheet and post extruded (profile) gloss properties and/or improved scratch-resistant properties.