Foam Rubber Molded Product Using Amorphous Copolymer
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Solution Overview
Problem
The existing foam rubber molded products face challenges in achieving uniform microdispersion of crystallizable olefin resins in EPDM matrices, requiring high temperatures and pressures, which leads to inconsistent physical properties and inadequate setting resistance.
Innovation Solution
Incorporating a small amount of amorphous 4-methyl-1-pentene copolymer into the ethylene-α-olefin-nonconjugated diene copolymer allows for easy formation of a homogeneous interconnected cell structure under typical rubber kneading conditions, enhancing both foaming and setting resistance without increasing temperature and pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If crystallizable polyolefin resin is microdispersed in EPDM matrix to form interconnected cell structure, then lightweight properties and compression set are improved, but higher temperature and pressure are required for kneading making process control difficult
Solution Approach 1:
The patent changes the chemical composition parameter by introducing amorphous 4-methyl-1-pentene copolymer with specific properties (amorphous structure, low glass transition temperature) to modify the kneading behavior of the rubber composition, enabling uniform microdispersion at typical kneading conditions without requiring extreme temperature and pressure
2Manufacturing precision
If higher temperature and pressure are applied for uniform microdispersion of crystallizable olefin resin, then dispersion uniformity is improved, but physical properties vary depending on product
Solution Approach 1:
The patent changes the material composition parameter by using amorphous 4-methyl-1-pentene copolymer which provides consistent rheological properties during kneading, leading to uniform microdispersion and stable physical properties across different products without requiring variable extreme kneading conditions
3Weight of moving object
If rubber is highly foamed to decrease specific gravity, then weight saving is achieved, but compression set increases deteriorating sealing performance
Solution Approach 1:
The patent creates a composite rubber composition by combining EPDM with amorphous 4-methyl-1-pentene copolymer, where the copolymer forms an interconnected cell structure that provides both lightweight properties (specific gravity 0.3 to 0.8) and maintains compression set below 27%, thus preserving sealing performance
Solution Approach 2:
The patent introduces local quality by creating an interconnected cell structure through the amorphous copolymer that is distributed throughout the rubber matrix, providing localized support that maintains compression resistance while achieving overall weight reduction through foaming
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 solution results in a foam rubber product with stable high foaming and setting resistance, ensuring consistent physical properties and improved sealing performance.
Implementation Method 1
addition of amorphous olefin polymer to an ethylene-α-olefin-nonconjugated diene copolymer can achieve easy formation of alloy under a typical rubber kneading condition without especially increasing the temperature and pressure
Implementation Method 2
2 to 8 parts by mass of blowing agent, and a sulfur-based vulcanizing agent... A specific gravity of the foam rubber molded product is 0.3 to 0.8. A foam state is an interconnected cell
Implementation Method 3
2 to 8 parts by mass of blowing agent, and a sulfur-based vulcanizing agent
Data Source
AI summary
A foam rubber molded produce obtained by molding a rubber composition containing 100 parts by mass of ethylene-α-olefin-nonconjugated diene copolymer, 4 to 30 parts by mass of amorphous 4-methyl-1-pentene copolymer, 2 to 8 parts by mass of blowing agent, and a sulfur-based vulcanizing agent, and having a Mooney viscosity after kneading (ML1+4, 100° C.) of 54 or less. A specific gravity is 0.3 to 0.8, a compression set is less than 27%, and a foam state is an interconnected cell.