Polyamide Thermoplastic Elastomer Tire Balancing Rim Fittability and Heat Resistance

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Solution Overview

Problem

Tires made from thermoplastic polymer materials face challenges in achieving balanced performance in rim fittability, low-temperature impact resistance, and heat resistance, as improving one aspect often compromises the others.

Innovation Solution

A tire design featuring a polyamide-based thermoplastic elastomer with a specific hard segment and soft segment composition, combined with a reinforcing cord layer wound at a controlled interval, to enhance rim fittability, low-temperature impact resistance, and heat resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the hard segment/soft segment ratio of the thermoplastic elastomer is adjusted to improve low-temperature impact resistance, then low-temperature impact resistance is improved, but heat resistance deteriorates

Engineering Contradiction:
Improvelow-temperature impact resistanceVSAvoidheat resistance
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The patent applies parameter changes by precisely controlling the molecular structure parameters of the thermoplastic elastomer. Specifically, it uses a polyamide-based elastomer with hard segments containing 20-80 mass% of a specific polyamide component (derived from diamine and dicarboxylic acid with specific carbon atom counts) and soft segments containing 80-95 mass% of a specific polyether component. This parameter control allows the material to achieve both low-temperature impact resistance (through the soft segment's flexibility) and heat resistance (through the hard segment's thermal stability), resolving the trade-off between these properties.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If thermoplastic polymer material is used to improve productivity and reduce cost, then productivity is improved and cost is reduced, but balanced performance in rim fittability, low-temperature impact resistance, and heat resistance deteriorates

Engineering Contradiction:
Improveproduction efficiencyVSAvoidbalanced performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent employs composite materials by creating a thermoplastic elastomer that combines polyamide hard segments with polyether soft segments in specific proportions. This composite structure at the molecular level allows the material to exhibit both the processability advantages of thermoplastics (improving productivity) and the performance characteristics of rubber (improving reliability). The specific composition ranges ensure that the material maintains rim fittability, low-temperature impact resistance, and heat resistance simultaneously, overcoming the limitations of conventional thermoplastic tire materials.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3392059B1tire
Publication Date: 2019.11.06 BRIDGESTONE CORP
  • EP3392059B1 patent drawingFigure 1A~1B
  • EP3392059B1 patent drawingFigure 2
  • EP3392059B1 patent drawingFigure 3

AI summary

A tire including: a circular tire frame that includes a polyamide-based thermoplastic elastomer having a hard segment and a soft segment, the hard segment containing a copolymer of a dicarboxylic acid having from 4 to 12 carbon atoms and a diamine having from 4 to 12 carbon atoms, and the soft segment containing a polyamine; and a reinforcing cord layer that includes a reinforcing cord member wound around an outer circumferential portion of the tire frame along a tire circumferential direction at an average interval of from 0.4 mm to 3.2 mm in a tire width direction.