Sound-Blocking Structure with Rubber-Elastic Resonant Portions

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Solution Overview

Problem

Existing sound insulating members, particularly sheet-like members, have not adequately improved sound insulating performance from the perspective of material properties, despite advancements in structure design.

Innovation Solution

The sound insulating structure body is designed with convex-shaped rubber-elastic resonant portions and a sheet-like support, where the storage modulus of the resonant portions is set within a specified range, and the areal density of the support is maintained within a predetermined range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional sheet-like sound insulating members are used with improved structural design, then sound insulating performance is partially improved, but material property optimization is insufficient

Engineering Contradiction:
Improvesound insulating performanceVSAvoidmaterial property complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by precisely controlling the storage modulus of the resonant portions (0.1 MPa to 100 MPa) and the areal density of the support (0.5 kg/m² to 5.0 kg/m²). These parameter optimizations enable the structure to achieve superior sound insulating performance while maintaining material simplicity, resolving the contradiction between performance improvement and material complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by combining rubber-elastic resonant portions with a support layer having specific areal density. This composite structure integrates the vibration damping properties of rubber-elastic materials with the structural support function, achieving both improved sound insulation and structural integrity without excessive complexity

Inventive Principle:
Principle #40Composite materials

2Reliability

If the storage modulus of resonant portions is reduced to improve sound insulation, then sound insulating performance improves, but structural strength may deteriorate

Engineering Contradiction:
Improvesound insulating performanceVSAvoidstructural strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent resolves this contradiction through parameter optimization by setting the storage modulus within 0.1 MPa to 100 MPa and the areal density within 0.5 kg/m² to 5.0 kg/m². These controlled parameter ranges ensure that the resonant portions provide sufficient vibration damping for sound insulation while the support maintains adequate structural strength

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The support layer acts as an intermediary element that bridges the resonant portions to the substrate. By controlling the areal density of the support, the patent ensures proper mechanical coupling between components, allowing the resonant portions to effectively dampen vibrations while maintaining overall structural integrity

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If the areal density of support is increased to improve structural stability, then structural strength improves, but sound insulating performance may deteriorate

Engineering Contradiction:
Improvestructural strengthVSAvoidsound insulating performance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent resolves this contradiction through precise parameter control by limiting the areal density of the support to 0.5 kg/m² to 5.0 kg/m². This optimized range provides sufficient structural stability while avoiding excessive mass that would hinder the vibration damping effectiveness of the resonant portions, thus maintaining sound insulating performance

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

This configuration achieves excellent sound insulating performance by optimizing the material properties and structural design, exceeding the mass law in sound insulation.

Implementation Method 1

a plurality of convex-shaped rubber-elastic resonant portions

Methodology Applied
Scientific EffectRubber-elasticity: Elasticity

Implementation Method 2

the storage modulus G' obtained from a composite curve of dynamic viscoelasticity

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 3

the storage modulus G' obtained from a composite curve of the dynamic viscoelasticity

Methodology Applied
Scientific EffectDynamic viscoelasticity: Viscoelasticity

Data Source

PatentEP3786944B1Composition for sound-blocking sheet member, sound-blocking sheet member, and sound-blocking structure body
Publication Date: 2025.06.11 MITSUBISHI CHEM CORP
  • EP3786944B1 patent drawingFigure 1
  • EP3786944B1 patent drawingFigure 2
  • EP3786944B1 patent drawingFigure 3

AI summary

Provided is a composition for a sound insulating sheet member, a sound insulating sheet member, and a sound insulating structure body with excellent sound insulating performance. A sound insulating structure body including: a plurality of convex-shaped rubber-elastic resonant portions; and a sheet-like support that supports the resonant portions, wherein the resonant portions have a storage modulus G' obtained from a composite curve of dynamic viscoelasticity according to ISO 6721-4 of 100 MPa or less at 25°C and 10 kHz, and the areal density of the support is 1.0 kg/m2 or less.