Adhesive Tape Shape Stability via Trouton Ratio Control

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Solution Overview

Problem

Adhesive tapes used for fixing electronic apparatus components often experience shape deformation under the weight of the components or external impacts, leading to positional shifts due to stress relaxation.

Innovation Solution

An adhesive tape with an adhesive layer containing a styrene-based block copolymer and an adhesiveness-imparting resin, characterized by a Trouton ratio of 3 or more to 90, extensional viscosity of 0.01 Pa·s or more to 40 Pa·s, and a storage elastic modulus of 1×10^4 Pa or more, which maintains its shape without plastic deformation under stress and impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional adhesive tapes are used to fix electronic apparatus components, then the components can be held in position, but the tape undergoes shape deformation under the weight of components or external impacts, leading to positional shifts

Engineering Contradiction:
Improvefixation reliabilityVSAvoidtape shape stability
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The patent applies parameter changes by precisely controlling the Trouton ratio of the adhesive composition within 3-90 and extensional viscosity within 0.01-40 Pa·s. These parameter optimizations enable the adhesive layer to maintain shape stability under stress while preserving fixation reliability, directly resolving the technical contradiction between reliability and shape stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by formulating an adhesive containing multiple components including styrene-based block copolymer, adhesiveness-imparting resin, and other functional additives. This composite adhesive composition achieves both high fixation reliability and shape stability under load, solving the contradiction between reliable fixation and resistance to deformation.

Inventive Principle:
Principle #40Composite materials

2Shape

If the adhesive layer is made thicker to improve shape stability, then resistance to deformation increases, but the tape becomes less flexible and harder to apply

Engineering Contradiction:
Improveshape stability under stressVSAvoidtape applicability
Core Design Contradiction:
ShapeVSEase of operation

Solution Approach 1:

The patent optimizes the extensional viscosity parameter to 0.01-40 Pa·s, which controls the adhesive's flow and deformation characteristics. This parameter optimization allows the adhesive layer to be thick enough for shape stability while remaining sufficiently flexible for easy application, resolving the contradiction between shape stability and ease of operation.

Inventive Principle:
Principle #35Parameter changes

3Shape

If the adhesive composition has high extensional viscosity to prevent deformation, then shape stability improves, but the adhesive becomes harder to apply and spread

Engineering Contradiction:
Improveresistance to deformationVSAvoidadhesive application ease
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The patent precisely controls the extensional viscosity parameter within 0.01-40 Pa·s and Trouton ratio within 3-90, creating an optimal balance point. This parameter optimization enables the adhesive composition to have sufficient resistance to deformation for shape stability while maintaining low enough viscosity for easy application and spreading during manufacturing.

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 adhesive tape effectively maintains its shape and stability, preventing positional shifts of fixed components even under excessive stress and impact, ensuring reliable fixation of electronic apparatus components.

Implementation Method 1

an adhesive composition used for producing the adhesive has a Trouton ratio of 3 or more and 90 or less when the adhesive composition is made into a toluene solution having a solid concentration of 25% (w/w) and is subjected to measurement at 35° C.

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 2

a storage elastic modulus E′ of the adhesive measured using a dynamic viscoelasticity spectrum at 1 Hz and 23° C. is 1×10 4 Pa or more

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentUS20240052216A1Adhesive tape and electronic apparatus
Publication Date: 2024.02.15 DIC CORP

AI summary

An adhesive tape is used for fixing a member constituting an electronic apparatus and includes an adhesive layer (A) and a base material (B). The adhesive layer (A) contains an adhesive containing a styrene-based block copolymer and an adhesiveness-imparting resin. The adhesive has a Trouton ratio of 3 or more and 90 or less when the adhesive composition is made into a toluene solution having a solid concentration of 25% (w/w) and is subjected to measurement at 35° C.