Tire Curing Bladder Composition Using Hydrocarbon Modifiers
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Solution Overview
Problem
There is a global shortage of butyl rubber and a need to improve the durability and service life of tire curing bladders, as well as enhance heat transport for more efficient curing processes in tire manufacturing, while reducing the use of butyl rubber.
Innovation Solution
A curing bladder composition comprising 100 parts of elastomer, 1-50 phr of hydrocarbon polymer modifier, and a curative, where the elastomer is at least 70% isobutylene-based, and the hydrocarbon polymer modifier has a softening point of 110°C to 150°C, including monomers like piperylenes, cyclic pentadienes, and aromatics, with specific properties to enhance tensile strength, tear resistance, and air permeation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If butyl rubber is used in curing bladder formulations, then heat aging resistance and air impermeability are improved, but material availability deteriorates due to global shortage
Solution Approach 1:
The patent modifies the chemical composition parameters by introducing hydrocarbon polymer modifiers (cyclic pentadienes, piperylenes, aromatics) to alter the elastomer's properties, achieving comparable heat resistance and air barrier performance with alternative materials that are more available
Solution Approach 2:
The patent creates a composite elastomeric composition by combining base elastomer (isobutylene-based) with hydrocarbon polymer modifiers and curatives, achieving synergistic effects that provide both heat aging resistance and air impermeability while using alternative materials
2Reliability
If butyl rubber is used in curing bladders, then air barrier performance is improved, but production cost increases due to shortage
Solution Approach 1:
The patent adjusts the compositional parameters by incorporating hydrocarbon polymer modifiers that provide comparable air barrier properties at lower cost, replacing expensive butyl rubber with more economical alternative elastomers
3Reliability
If traditional curing bladder materials are used, then durability is maintained, but service life is limited
Solution Approach 1:
The patent optimizes the chemical composition parameters including elastomer type, hydrocarbon polymer modifier content (1-50 phr), and curative selection to enhance both durability and service life, achieving extended operational duration
Solution Approach 2:
The patent develops a composite elastomeric composition that combines base elastomer with hydrocarbon polymer modifiers and curatives to create a material system that simultaneously improves durability and extends service life
4Ease of manufacture
If conventional bladder formulations are used, then manufacturing simplicity is maintained, but heat transport efficiency is insufficient
Solution Approach 1:
The patent modifies the formulation parameters by selecting specific elastomer types and hydrocarbon polymer modifiers that inherently improve thermal conductivity, enhancing heat transport efficiency while maintaining ease of manufacture through standard processing
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 extends the pull point of the curing bladder, improves heat transport, and reduces the amount of butyl rubber required, leading to increased production rates and durability while maintaining air barrier performance.
Implementation Method 1
comprising 100 parts by weight of elastomer, a curative, and from 1 phr to 50 phr of a hydrocarbon polymer modifier, wherein the elastomer comprises at least one isobutylene based elastomer, wherein the hydrocarbon polymer modifier has a softening point as determined by the Ring and Ball method (ASTM E-28) of from 110oC to 150oC and comprises monomers selected from the group consisting of piperylenes, cyclic pentadienes, aromatics, limonenes, pinenes, amylenes, and combinations thereof
Implementation Method 2
There is also an ongoing need to improve heat transport through the bladder to improve the efficiency of the curing process and increase production rates on the vulcanization press
Implementation Method 3
Butyl rubber, e.g., isobutylene-isoprene copolymer, is the elastomer of choice in curing bladder formulations due to excellent heat aging resistance, good flex and tear resistance, and impermeability to air, inert gases, and water vapor
Implementation Method 4
The green tire construct is pressed outwardly against a mold surface by means of an inner fluid-expandable bladder... By application of heat and pressure via the curing bladder, the tire is molded and vulcanized at elevated temperatures
Data Source
AI summary
An elastomeric composition for a curing bladder comprises isobutylene based elastomer, curative and a hydrocarbon polymer modifier comprising monomers selected from the group consisting of piperylenes, cyclic pentadienes, aromatics, limonenes, pinenes, amylenes, and combinations thereof, wherein the cyclic pentadienes comprise at least 10 weight percent of the monomers by total weight of the monomers. Also disclosed are a tire curing bladder made from the elastomeric composition, a tire curing press containing the bladder, a method of making the tire curing bladder, an improvement to the process of making the tire curing bladder to improve processability of the mixture and fatigue life and DeMattia cut growth, a method of making a tire using the tire curing bladder, and an improvement to the process of making a tire to extend a pull point of the curing bladder and/or to reduce the curing time for the tire construct.