Farnesene Polymer Shoe Midsole for High Loss Tangent Cushioning

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Solution Overview

Problem

Current foam cushions in shoes do not effectively achieve high cushioning characteristics, as measured by the loss tangent ratio of loss elastic modulus to storage elastic modulus, limiting their cushioning performance.

Innovation Solution

A shoe midsole composed entirely of a polymer composition that includes farnesene-based polymers and ethylene-α-olefin block copolymers or ethylene-vinyl acetate copolymers, which enhance the loss tangent value, providing improved cushioning properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional foam materials are used in cushioning applications, then the cushion structure is simple and easy to manufacture, but the loss tangent value is insufficient and cushioning performance is limited

Engineering Contradiction:
Improvecushioning performanceVSAvoidpolymer composition complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining farnesene-based polymers with other polymers (such as polyurethane, polyester, or polyether) to create a multi-component polymer composition. This composite approach enables the foam to achieve a loss tangent of 0.08 or higher, significantly improving cushioning performance while maintaining structural integrity and manufacturability

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent utilizes parameter changes by specifically selecting farnesene-based polymers with controlled hardness (20-80° Shore A) and combining them in specific ratios (5-50 mass%) with other polymers. This parameter optimization transforms the viscoelastic properties of the foam, achieving high loss tangent values and superior cushioning characteristics

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the loss tangent of the foam is increased to improve cushioning characteristics, then cushioning performance is enhanced, but the formulation and manufacturing process becomes more complex

Engineering Contradiction:
Improvecushioning characteristicsVSAvoidfoam formulation complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent simplifies manufacturing by establishing specific parameter ranges: farnesene-based polymer content of 5-50 mass%, hardness of 20-80° Shore A, and controlled gel fraction (20-80%). These defined parameters provide a clear formulation guide that achieves high loss tangent (≥0.08) while maintaining ease of manufacture through standardized production parameters

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 polymer composition significantly increases the loss tangent value of the foam, resulting in enhanced cushioning performance and comfort by effectively absorbing shock, making the shoe more comfortable for walking and running.

Implementation Method 1

The degree of cushioning characteristics exhibited by a foam or the like is generally represented by, for example, a ratio (loss tangent) of a loss elastic modulus to a storage elastic modulus obtained by a kinematic viscoelasticity measurement

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Data Source

PatentEP3841909B1Cushion and shoe
Publication Date: 2024.02.07 ASICS CORP
  • EP3841909B1 patent drawingFigure 1
  • EP3841909B1 patent drawingFigure 2
  • EP3841909B1 patent drawingFigure 3

AI summary

The present invention provides a cushion partially or entirely composed of a foam, the foam composed of a polymer composition that includes a homopolymer or a copolymer including a constituent unit derived from farnesene.