Elastomeric Tire Composition for Winter Grip and Wear Balance

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Solution Overview

Problem

Current tire compositions struggle to achieve an optimal balance between grip and braking performance on dry and wet surfaces, as well as on snow, without compromising other essential properties like rolling resistance and wear resistance, especially at low temperatures.

Innovation Solution

A specific elastomeric composition for tires is developed, comprising a combination of at least one liquid polymer, one resin, 100 phr of solid diene elastomeric polymer, and at least 30 phr of reinforcing filler, processed through a unique mixing and dispersion step followed by a reworking step under continuous mixer with suction pressure less than 150 mbar, to enhance the tire's performance across various weather conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If softer tread materials are used to improve grip on snow, then winter properties are improved, but wear resistance and rolling resistance deteriorate

Engineering Contradiction:
Improvegrip on snowVSAvoidwear resistance
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent uses parameter changes by controlling the glass transition temperature of the liquid polymer (Tg ≤ 0°C) to ensure the material remains soft and flexible at low temperatures for good snow grip, while the resin component (Tg ≥ 25°C) provides structural support for wear resistance. The optimized quantity ratios maintain this dual characteristic throughout the service life

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies partial action by using moderate amounts of liquid polymer (1-40 phr) and resin (1-30 phr) rather than excessive softening agents. This partial incorporation provides sufficient snow grip improvement while avoiding excessive softness that would compromise wear resistance and rolling resistance

Inventive Principle:
Principle #16Partial or excessive action

2Stability of the object's composition

If continuous mixing process is used to improve dispersion of liquid polymer and resin, then homogeneity is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvehomogeneity of dispersionVSAvoidmixing process complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies continuity of useful action by using a continuous mixing process where liquid polymer and resin are continuously fed and mixed with solid diene elastomeric polymer and reinforcing filler. This continuous action ensures uniform dispersion and homogeneous composition throughout the tread material, resolving the homogeneity requirement while maintaining efficient production

Inventive Principle:
Principle #20Continuity of useful action

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 composition significantly improves the tire's behavior on both dry and wet surfaces while maintaining high performance on snow, achieving an optimal balance of conflicting properties such as grip, braking, rolling resistance, and wear resistance.

Implementation Method 1

mixing said first elastomeric composition and dispersing therein the liquid polymer (A) and/or the resin (B) possibly fed in step (P2), by means of said at least one continuous mixer, preferably by applying, to said continuous mixer, a suction pressure (Pa) less than about 150 mbar

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP3350259B1Elastomeric compositions for tyre components and tyres thereof
Publication Date: 2019.09.04 PIRELLI TYRE SPA
  • EP3350259B1 patent drawingFigure 1
  • EP3350259B1 patent drawingFigure 2
  • EP3350259B1 patent drawingFigure 3

AI summary

The present invention relates to a tyre for vehicles for winter or for all seasons, comprising a component, preferably a tread band, obtained by vulcanisation of a new elastomeric composition. Said elastomeric composition comprises inter alia a plasticising mixture of liquid polymer (A), resin (B) and optionally plasticising oil (C) that is incorporated in the composition with a process P comprising a mixing and dispersion step (P1) followed by a continuous processing step (P2), preferably under high vacuum. Said tyre surprisingly exhibits an optimal balance of notoriously conflicting properties, such as the behaviour on wet and dry, driving and braking at low temperatures on snow.