Ethylene-Diene Rubber Composition for Faster Vulcanization
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Solution Overview
Problem
Diene rubber compositions containing highly saturated copolymers of ethylene and 1,3-butadiene require long residence times in curing presses, leading to reduced productivity and increased stiffness, making them unsuitable for certain applications, and premature removal results in insufficient curing and increased hysteresis.
Innovation Solution
A rubber composition comprising a copolymer of ethylene, 1,3-butadiene, and a second 1,3-diene with more than 50 mol % ethylene units, combined with a reinforcing filler and a vulcanization system, which allows for improved vulcanization kinetics and reduced residence time, balancing stiffness and hysteresis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If copolymers with more than 50 mol % ethylene units are used in rubber compositions, then the rubber composition exhibits higher stiffness, but the residence time in curing press increases and productivity decreases
Solution Approach 1:
The patent modifies the chemical composition parameters of the elastomer by incorporating a second 1,3-diene with specific molecular structure (formula I) alongside ethylene and first 1,3-diene units. This compositional parameter change alters the vulcanization kinetics and molecular mobility, enabling the rubber to achieve desired stiffness with reduced curing time, thus resolving the contradiction between stiffness improvement and productivity maintenance
2Strength
If copolymers with more than 50 mol % ethylene units are used in rubber compositions, then the degree of vulcanization increases, but hysteresis increases when removed prematurely
Solution Approach 1:
The patent changes the chemical composition parameters by incorporating a second 1,3-diene with formula I that has specific structural characteristics (unsaturated aliphatic hydrocarbon chain with 3 to 20 carbon atoms). This compositional modification alters the vulcanization reaction kinetics and crosslinking density, enabling the rubber to achieve adequate vulcanization degree with lower hysteresis even at reduced residence times, thus resolving the contradiction between achieving sufficient vulcanization and minimizing hysteresis
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 enables a compromise between stiffness and hysteresis, reducing vulcanization time and improving the curing efficiency of the rubber composition, making it suitable for various applications while maintaining performance.
Implementation Method 1
a vulcanization system and more than 50 to 100 phr of an elastomer which contains more than 50 mol % of ethylene units and which is a copolymer of ethylene, of a first 1,3-diene which is 1,3-butadiene, isoprene or a mixture thereof, and of a second 1,3-diene
Data Source
AI summary
The invention relates to a rubber composition which comprises a reinforcing filler, a vulcanization system and more than 50 to 100 phr of an elastomer which contains more than 50 mol % of ethylene units and which is a copolymer of ethylene, of a first 1,3-diene which is 1,3-butadiene, isoprene or a mixture thereof, and of a second 1,3-diene of formula CH2═CR—CH═CH2, the symbol R representing an unsaturated aliphatic hydrocarbon chain having 3 to 20 carbon atoms.