Heavy-Duty Tire Tread Rubber Composition with Organic Crosslinking Agent
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Heavy-duty tire treads face challenges with abrasion resistance and fuel efficiency due to reversion in sulfur-vulcanized natural rubber compositions, leading to decreased performance over time.
Innovation Solution
A rubber composition method using a specific organic crosslinking agent, natural rubber, carbon black, and sulfur, with a predetermined ratio and kneading process to enhance abrasion resistance, involving a first step of kneading the rubber component and carbon black with the organic crosslinking agent, followed by kneading sulfur and a vulcanization accelerator in a second step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If sulfur is used as a vulcanizing agent in natural rubber composition, then crosslinking strength is improved, but reversion occurs due to over-vulcanization leading to decreased abrasion resistance
Solution Approach 1:
The patent changes the chemical parameters of the crosslinking system by introducing organic crosslinking agents (dithiocarbamates, xanthates, or dithiophosphates) with specific molecular structures and crosslinking densities. By controlling the type and amount of organic crosslinking agent (0.1-5 parts per 100 parts rubber), the patent modifies the crosslinking mechanism to prevent reversion while maintaining strength, thus resolving the contradiction between crosslinking strength and abrasion resistance
Solution Approach 2:
The patent creates a composite vulcanization system combining sulfur (0.1-0.7 parts) with organic crosslinking agents in a multi-component formulation. This composite approach allows the sulfur to provide initial crosslinking while the organic crosslinking agents prevent reversion and enhance abrasion resistance, achieving both strong crosslinking and reliable durability simultaneously
2Reliability
If the blending amount of vulcanization accelerator with respect to sulfur is increased to improve heat resistance, then reversion is inhibited, but abrasion resistance decreases and low fuel consumption performance is decreased
Solution Approach 1:
The patent changes the vulcanization chemistry by using organic crosslinking agents that operate at lower accelerator levels. The specific organic crosslinking agents (dithiocarbamates, xanthates, or dithiophosphates) provide heat resistance and reversion prevention through their molecular structure rather than through high accelerator content, thus maintaining fuel efficiency while achieving reliable heat resistance
Solution Approach 2:
The patent employs small amounts of highly effective organic crosslinking agents that provide long-lasting reversion prevention and abrasion resistance without requiring large quantities of accelerator. This efficient use of chemical additives minimizes energy loss while achieving the desired heat resistance and durability
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 method significantly improves abrasion resistance and maintains fuel efficiency by forming stronger crosslinks and inhibiting deterioration, even with limited sulfur content, resulting in enhanced tire performance.
Implementation Method 1
an organic crosslinking agent represented by formula (1) below... R1 and R2 are the same or different from each other, and each represent a monovalent organic group containing a nitrogen atom
Implementation Method 2
sulfur, and a vulcanization accelerator... a second step of kneading a kneaded product obtained in the first step, the sulfur, and the vulcanization accelerator
Data Source
AI summary
A method for producing a rubber composition for a heavy-duty tire tread having excellent abrasion resistance is provided. The method for producing the rubber composition for a heavy-duty tire tread is a method for producing a rubber composition for a heavy-duty tire tread, the rubber composition containing a rubber component, carbon black, an organic crosslinking agent represented by formula (1) below, sulfur, and a vulcanization accelerator, wherein an amount of a natural rubber in 100% by mass of the rubber component is not less than 75% by mass, an amount of the carbon black per 100 parts by mass of the rubber component is not less than 50 parts by mass, an amount of the sulfur per 100 parts by mass of the rubber component is 0.1 to 0.7 parts by mass, and the method includes: a first step of kneading the rubber component, the carbon black, and the organic crosslinking agent; and a second step of kneading a kneaded product obtained in the first step, the sulfur, and the vulcanization accelerator, R1-(S)n-A-(S)m-R2 (1) wherein A represents an alkylene group having 2 to 10 carbon atoms, R1 and R2 are the same or different from each other, and each represent a monovalent organic group containing a nitrogen atom, and n and m each independently represent an integer of 2 to 4.