Non-crosslinked Amide Elastomer Foam Particles for Resilience

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Solution Overview

Problem

Existing expanded molded articles, such as those made from polystyrene, suffer from low recoverability and resilience, making them unsuitable for repeated compression or flexible applications, and they have a coarse and uneven cell structure, which affects their appearance and functionality.

Innovation Solution

The development of amide-based elastomer expanded particles with specific Shore D hardness, storage moduli, and cell diameters, which are non-crosslinked and impregnated with a blowing agent, allowing for excellent moldability, recoverability, and a fine uniform cell structure, enabling the production of expanded molded articles with improved resilience and expandability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If crosslinked amide-based elastomer expanded particles are used to improve recoverability and resilience, then rubber elasticity is enhanced, but moldability deteriorates due to surface elongation and deficiency in fusion between particles

Engineering Contradiction:
Improverecoverability and resilienceVSAvoidmoldability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the crosslinking component from the elastomer structure. By using non-crosslinked amide-based elastomer, the invention eliminates the surface elongation and fusion deficiency problems that occur with crosslinked structures, while maintaining good recoverability and resilience through the elastomer's inherent properties.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent specifies precise parameter ranges for the non-crosslinked amide-based elastomer, including Shore D hardness (40-65), storage modulus at specific temperatures, and gel fraction (0-10%). By controlling these parameters, the invention achieves optimal balance between moldability and mechanical properties without requiring crosslinking.

Inventive Principle:
Principle #35Parameter changes

2Strength

If polystyrene is used as the base resin to achieve high rigidity, then structural strength is improved, but recoverability and resilience become low

Engineering Contradiction:
ImproverigidityVSAvoidrecoverability and resilience
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent uses amide-based elastomer as the base resin, which inherently combines rigidity from the polyamide hard segments with elasticity from the polyether soft segments. This composite structure at the molecular level provides both the required strength and the recoverability/resilience that pure polystyrene cannot achieve.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the fundamental material parameter from polystyrene to non-crosslinked amide-based elastomer with specific Shore D hardness (40-65) and storage modulus characteristics. This material substitution fundamentally alters the balance between rigidity and elasticity, enabling both properties to coexist.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If expanded particles with coarse cell structure are used, then manufacturing simplicity is maintained, but appearance and functionality are deteriorated

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcell structure uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent specifies that the average cell diameter should be 50-200 μm, which is finer than conventional expanded particles. This parameter control, combined with using non-crosslinked amide-based elastomer with specific viscosity characteristics, produces a fine uniform cell structure that improves both appearance and functionality while maintaining manufacturing simplicity.

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 amide-based elastomer expanded particles result in molded articles with enhanced recoverability, resilience, and a fine uniform cell structure, suitable for various applications including industrial uses, such as core materials and cushion fillers, with improved compression set and restitution coefficients.

Implementation Method 1

a non-crosslinked amide-based elastomer having a Shore D hardness of 65 or less and both of a storage modulus at a temperature of crystallization temperature - 10°C and a storage modulus at a temperature of crystallization temperature - 15°C in a range of 4 × 10^6 to 4 × 10^8 Pa

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 2

imregnated with a blowing agent, allowing for excellent moldability, recoverability, and a fine uniform cell structure

Methodology Applied
Scientific EffectGas expansion: Thermal Expansion

Data Source

PatentEP3202835B2Amide elastomer foam particles, method for producing same, foam molded body and method for producing foam molded body
Publication Date: 2023.05.17 SEKISUI PLASTICS CO LTD
  • EP3202835B2 patent drawingFigure 1~2
  • EP3202835B2 patent drawingFigure 3~4
  • EP3202835B2 patent drawingFigure 5~6

AI summary

Amide-based elastomer expanded particles comprising, as a base resin, a non-crosslinked amide-based elastomer having a Shore D hardness of 65 or less, and having an average cell diameter of 20 to 250 µm.