Tire Rubber Composition to Limit Extractable Migration

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Solution Overview

Problem

Tires face a challenge in maintaining good ride quality over a long period due to the migration of acetone extractable components, which leads to degradation.

Innovation Solution

A tire component comprising a rubber composition with a copolymer having ethylene and styrene units and a modifying group capable of reacting with carbon black or silica, combined with carbon black, to suppress the migration of oils and enhance dispersion, while maintaining specific thickness parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional rubber compositions are used, then initial ride quality is achieved, but acetone extractable components migrate over time causing degradation

Engineering Contradiction:
Improveride quality maintenanceVSAvoidacetone extractable component migration
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

A silane-modified polybutadiene rubber is introduced as an intermediary substance that reacts with carbon black to form a coupling agent. This intermediary prevents the migration of acetone extractable components by creating a chemical bond network between the rubber matrix and carbon black filler, thereby maintaining ride quality over time while reducing substance loss.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a composite rubber composition combining silane-modified polybutadiene rubber with carbon black and silica. This composite material structure creates a synergistic effect where the silane-modified rubber acts as a coupling agent between fillers, reducing extractable component migration and improving long-term reliability without sacrificing initial performance.

Inventive Principle:
Principle #40Composite materials

2Reliability

If carbon black is added to improve dispersion and reduce migration, then ride quality maintenance improves, but manufacturing complexity increases

Engineering Contradiction:
Improveride quality maintenanceVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The polybutadiene rubber is pre-modified with silane groups before compounding with carbon black. This preliminary modification creates a coupling agent that automatically bonds with carbon black during mixing, eliminating the need for additional coupling agent addition steps and simplifying the manufacturing process while achieving improved filler dispersion and reduced extractable migration.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the chemical parameters of the rubber by introducing silane modification to polybutadiene. This parameter change enables the rubber to chemically interact with carbon black, improving dispersion and reducing migration without requiring complex manufacturing processes or additional additives.

Inventive Principle:
Principle #35Parameter changes

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 tire maintains good ride quality over time by reducing the migration of acetone extractable components and enhancing carbon black dispersion, thus preserving performance.

Implementation Method 1

a copolymer having an ethylene unit and a styrene unit and having a modifying group capable of reacting with at least one of carbon black or silica

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

enhancing carbon black dispersion

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Data Source

PatentEP4364963B1tire
Publication Date: 2026.03.25 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4364963B1 patent drawingFigure 1
  • EP4364963B1 patent drawingFigure 2
  • EP4364963B1 patent drawingFigure 3

AI summary

Provided is a tire capable of maintaining good ride quality even after a long period of time. The tire includes a tire component, the tire component containing: a rubber component including a copolymer having an ethylene unit and a styrene unit and having a modifying group capable of reacting with at least one of carbon black or silica, and at least one of an isoprene-based rubber or polybutadiene rubber; and carbon black, the tire satisfying the following formula (1) and at least one of the following formula (2) or the following formula (3): AE>5.0 where AE denotes an acetone extractable content (% by mass) of the tire component, Tw<12.0 where Tw denotes a thickness (mm) of a surface rubber layer at a tire maximum width position, Tt<12.0 where Tt denotes a thickness (mm) of a tread portion.