Propylene-Based Tie Layer Composition for High-Temperature Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional tie layers fail to maintain adhesion between polypropylene and polar layers at high temperatures, leading to delamination issues.
Innovation Solution
A tie layer comprising propylene-based polymers, functionalized propylene, and modifiers such as olefin block copolymers, ethylene acid copolymers, and ethylene propylene diene terpolymers, which provide enhanced adhesion and heat resistance up to temperatures of 130 °C or higher.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional tie layers are used, then the coating can adhere to the substrate at normal temperatures, but the adhesion fails and delamination occurs at high temperatures (at least 100 °C)
Solution Approach 1:
The patent changes the chemical composition parameters of the tie layer by incorporating specific polymers (polypropylene, polyethylene), functionalized components (maleated polypropylene, carboxylated polyethylene) with defined grafting levels (0.5-5.0 wt%), and modifiers (ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer) in controlled ratios. These compositional parameter changes enable the tie layer to maintain adhesion stability at high temperatures up to 130°C or higher, resolving the contradiction between normal temperature adhesion and high temperature resistance
Solution Approach 2:
The patent creates a composite tie layer material system combining multiple polymer components with complementary properties: polypropylene and polyethylene provide base adhesion, maleated polypropylene and carboxylated polyethylene provide polar bonding groups for enhanced chemical adhesion, and modifiers like ethylene-vinyl acetate copolymer provide flexibility and thermal stability. This composite material approach enables the tie layer to withstand high temperatures while maintaining adhesion between the coating and substrate
2Reliability
If the tie layer is designed for high temperature resistance (at least 100 °C), then delamination is prevented, but the formulation complexity and manufacturing difficulty increase
Solution Approach 1:
The patent establishes specific parameter ranges for each component to balance performance and manufacturability: functionalized polymers with 0.5-5.0 wt% grafting content, modifiers at 1-10 wt%, and controlled melt flow rates (1-20 dg/min for propylene-based polymer). These quantified parameters provide clear manufacturing specifications that simplify production while ensuring high temperature resistance, resolving the contradiction between heat resistance and ease of manufacture
Solution Approach 2:
The patent designs a universal tie layer formulation that can be applied to various coating-substrate systems (metalized films, paperboard, aluminum foil) through co-extrusion or lamination processes. The multi-functional composition provides adhesion, flexibility, and thermal stability in a single integrated layer, reducing the need for multiple specialized layers and simplifying the overall manufacturing process while maintaining heat resistance
Data Source
AI summary
A coated substrate including a polar layer, at least one polypropylene layer, and at least one tie layer that adheres the polypropylene layer to the polar layer, wherein the tie layer includes at least one propylene-based polymer having a melt flow rate (MFR) (230 °C/ 2.16 kg) of 1.0 to 20.0 dg/min and a melting temperature greater than 130 °C, functionalized polypropylene having an MFR (160 °C/ 0.325 kg) of 5.0 to 50.0 dg/min determined by ASTM D1238, ISO 1133), wherein the functionalized polypropylene comprises a polypropylene grafted with ethylenically unsubstituted dicarboxylic acid; and a modifier comprising at least one of an olefin block copolymer, an ethylene acid copolymer, an ethylene alkyl acrylate copolymer, and ethylene propylene diene terpolymer.