Rubber-Coating Mixture for Tire Cords With Aging-Resistant Adhesion
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Solution Overview
Problem
Existing rubberization mixtures for metallic strength members, particularly in pneumatic vehicle tires, face challenges in maintaining adhesion properties after aging, and often rely on hazardous resorcinol-based systems.
Innovation Solution
A sulfur-crosslinkable rubberization mixture containing 0.25 to 5 phr of a novolac resin with alkylurethane units, produced by reaction of a phenolic compound and a carbamate resin, combined with 0.5 to 3 phr of a sulfenimide accelerator, which enhances adhesion and eliminates the need for hazardous sulfenamide accelerators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resorcinol-based adhesive systems are used in rubberization mixtures, then initial adhesion to metallic strength members is achieved, but adhesion properties deteriorate after aging and the system is hazardous to health and environment
Solution Approach 1:
The patent changes the chemical composition parameters by replacing resorcinol-based systems with novolac resin systems containing alkylurethane units. This substitution maintains adhesion functionality while eliminating the harmful effects of resorcinol, directly resolving the contradiction between reliability and harmful factors.
Solution Approach 2:
The patent employs a composite adhesive system combining novolac resin with alkylurethane units and sulfenimide accelerators. This composite material approach creates a new chemical system that achieves both good aging resistance and eliminates health/environmental hazards associated with traditional resorcinol-based systems.
2Reliability
If traditional sulfenamide accelerators are used in rubberization mixtures, then vulcanization process is achieved, but adhesion properties deteriorate after aging
Solution Approach 1:
The patent changes the accelerator type from sulfenamide to sulfenimide, which fundamentally alters the vulcanization chemistry. This parameter change results in improved adhesion stability after aging while maintaining effective vulcanization, directly resolving the contradiction between aging resistance and product durability.
3Reliability
If novolac resin with alkylurethane units and sulfenimide accelerator are used in rubberization mixture, then adhesion to metallic strength members is improved after aging, but formulation complexity increases
Solution Approach 1:
The patent merges the adhesive function of novolac resin with the vulcanization acceleration function of sulfenimide accelerators in a single integrated formulation. This combination achieves improved adhesion after aging while managing formulation complexity through synergistic interaction between components rather than separate additive systems.
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 combination of novolac resin and sulfenimide accelerator improves adhesion to metallic strength members even after aging, leading to enhanced durability of rubber products and reduced environmental and health risks.
Implementation Method 1
The methylene donor and the methylene acceptor form a resin during the vulcanization process. In addition to the sulfur network a second network based on methylene donor and methylene acceptor, which enters into adhesive interaction with the surface of the strength member, is formed.
Implementation Method 2
sulfur-crosslinkable rubberization mixture... contains at least one novolac resin and at least one sulfenimide accelerator
Data Source
AI summary
A sulfur-crosslinkable rubberization mixture for metallic strength members which contains 0.25 to 5 phr (parts by weight, based on 100 parts by weight of the total rubbers in the mixture) of at least one novolac resin which comprises alkylurethane units and is produced by reaction of a phenolic compound, an aldehyde and a carbamate resin, wherein the carbamate resin is produced by reaction of alkylurethane with an aldehyde, and 0.5 to 3 phr of at least one sulfenimide accelerator. Also provided is a pneumatic vehicle tire which includes at least one such sulfur-crosslinked rubberization mixture.