Indole Rubber Stabilizer for Tire Ozone and Oxidation Protection
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Solution Overview
Problem
Existing aging stabilizers for vehicle tires, such as aromatic amines, are suspected to be carcinogenic and may not provide effective protection against oxidation and ozone due to potential bonding with rubber, limiting their effectiveness and posing health hazards.
Innovation Solution
A novel indole derivative compound with specific aromatic and aliphatic radicals is developed, offering improved solubility and reactivity as an aging stabilizer and antiozonant, reducing health hazards and enhancing protection against oxidation without vulcanizable groups that could limit its effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If aromatic amine aging stabilizers (6-PPD, IPPD, SPPD) are used to protect rubber from oxidation and ozone, then protection effectiveness is improved, but health hazards (carcinogenicity) increase
Solution Approach 1:
The patent changes the chemical structure parameters of aging stabilizers by replacing aromatic amine compounds with indole derivative compounds having specific molecular structures (formula I). This structural parameter change maintains the stabilizer's ability to scavenge free radicals and protect rubber while eliminating the carcinogenic properties associated with aromatic amines, thus resolving the contradiction between protection effectiveness and health hazards
Solution Approach 2:
The patent employs indole derivative stabilizers that function effectively but do not require long-term persistence in the rubber matrix. These stabilizers provide sufficient protection during the service life of the rubber product without needing to be permanently bound, allowing for effective yet temporary action that reduces health risks associated with long-term exposure to stable aromatic amine compounds
2Reliability
If aromatic amine aging stabilizers are used to protect rubber, then protection against oxidation is improved, but solubility in rubber matrix deteriorates leading to blooming
Solution Approach 1:
The patent modifies molecular structure parameters of the stabilizer compounds by introducing specific indole core structures with adjustable substituents (R1, R2, R3 groups) that enhance compatibility with rubber matrices. This structural optimization improves solubility and prevents blooming while maintaining the free radical scavenging capability necessary for oxidation protection
Solution Approach 2:
The patent creates a composite system where indole derivative stabilizers are integrated into the rubber matrix at molecular level. The specific molecular architecture of these stabilizers allows them to function as both protective agents and matrix-compatible components, preventing phase separation and blooming that occur with conventional aromatic amine stabilizers
3Strength
If stabilizers with vulcanizable groups are used, then bonding with rubber occurs, but protection effectiveness is limited
Solution Approach 1:
The patent extracts and eliminates the vulcanizable groups from the stabilizer molecular structure. By removing these reactive groups that cause bonding with rubber, the stabilizer maintains its mobility and ability to scavenge free radicals throughout the rubber matrix, thereby improving protection effectiveness while avoiding the limitations imposed by chemical bonding
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 indole derivative compound effectively stabilizes vehicle tires against oxidation and ozone, providing optimal protection while being less hazardous to health and the environment, as demonstrated by its performance in rubber mixtures and comparison with traditional stabilizers.
Implementation Method 1
natural rubber and synthetic polymers (such as IR, BR, SSBR, ESBR etc.) but also natural and synthetic oils, fats and lubricants are subject to oxidation reactions which have an adverse effect on the originally desired properties
Implementation Method 2
These molecules can react with oxygen or ozone or free radicals formed, such as alkyl, alkoxy and alkylperoxy radicals, and thus scavenge these and accordingly protect the rubbers etc. from further oxidation reactions
Data Source
AI summary
A compound, a rubber mixture containing the compound, a vehicle tire comprising the rubber mixture in at least one component, a process for producing the compound and the use of the compound as an aging stabilizer and/or antiozonant and/or dye, in which, the compound has the formula (I), wherein A is an aromatic radical optionally bearing additional substituents, and wherein R1 is selected from the group consisting of xi) aromatic radicals, wherein the aromatic radicals optionally bear substituents selected from the group consisting of halogen radicals, cyano radicals, ester radicals, ketone radicals, ether radicals and thioether radicals, and xii) linear, branched and cyclic aliphatic C1- to C12-radicals, and xiii) combinations of aromatic and aliphatic C1- to C12-radicals.