Multiphase Adhesive Laminate for High Peel Strength in Thin Bond Lines

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Solution Overview

Problem

Existing laminate bodies face challenges in achieving high peel strength with thin adhesive layers, particularly when subjected to tensile stress, which hinders compact structure design and storage due to the trade-off between adhesive thickness and structural integrity.

Innovation Solution

A laminate body structure where two or more types of curable adhesive compositions with different stress levels at 10 mm elongation are applied in parallel and integrated, with one composition having 2 to 5 times more stress than the other, forming an adhesive layer that is 1 mm or less in thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a thick adhesive layer is applied to ensure high adhesive strength and peel strength, then the joining strength between base materials is improved, but the laminate body cannot satisfy the required properties of compact structure such as miniaturization, thinning, foldability, and storability

Engineering Contradiction:
Improvepeel strengthVSAvoidadhesive layer thickness
Core Design Contradiction:
StrengthVSLength of moving object

Solution Approach 1:

The patent applies composite materials by combining two or more types of curable adhesive compositions with different elasticities (high-elasticity and low-elasticity adhesives) to form a multi-phase adhesive layer. This composite structure enables the thin adhesive layer (1 mm or less) to achieve high peel strength by utilizing the complementary properties of different adhesive materials - the high-elasticity component provides flexibility and conformability while the low-elasticity component provides structural integrity and resistance to penetration, resolving the contradiction between thinness and strength

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the physical and chemical parameters of the adhesive system by using curable adhesive compositions that undergo phase transformation during curing. The adhesive compositions are applied in an uncured state allowing for thin application, then cured to achieve the desired mechanical properties. This parameter change enables the adhesive layer to be thin yet maintain high peel strength after curing

Inventive Principle:
Principle #35Parameter changes

2Strength

If base materials are joined by sewing to ensure joining strength, then the structural integrity is improved, but the thickness of the base material and wide sewing site must be ensured, making it difficult to store the laminate body as a compact structure

Engineering Contradiction:
Improvejoining strengthVSAvoidsewing site thickness
Core Design Contradiction:
StrengthVSLength of moving object

Solution Approach 1:

The patent replaces the mechanical joining system (sewing with needles and threads) with a chemical bonding system (adhesive composition). This substitution eliminates the need for physical penetration through the base materials, allowing for thin base materials and compact structures while maintaining joining strength. The adhesive forms a continuous bonding layer without creating holes or requiring wide sewing sites

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Length of moving object

If a thin adhesive layer is applied to achieve compact structure, then the laminate body satisfies miniaturization and thinning requirements, but the adhesive strength and peel strength are insufficient

Engineering Contradiction:
Improveadhesive layer thicknessVSAvoidadhesive strength
Core Design Contradiction:
Length of moving objectVSStrength

Solution Approach 1:

The patent uses composite materials by formulating the thin adhesive layer with multiple adhesive compositions having different elasticities. The high-elasticity adhesive provides flexibility and conformability to the thin layer structure, while the low-elasticity adhesive provides the necessary bonding strength. This composite approach enables the thin adhesive layer to achieve both compactness and sufficient adhesive strength simultaneously

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP4711128A1Multilayer body capable of achieving high peel strength even with thin adhesive layer, method for producing same, and method for bonding base materials
Publication Date: 2026.03.18 DOW TORAY CO LTD
  • EP4711128A1 patent drawingFigure 1~5
  • EP4711128A1 patent drawingFigure 6~8
  • EP4711128A1 patent drawingFigure 9~10

AI summary

[Problem] To provide: a laminate body that has excellent industrial productivity, can be implemented at low cost, can be applied to laminate bodies using not only a base fabric/film base material but also various other base materials, and can achieve high peel strength even with a thin adhesive layer when an external force is applied to move the adhered base materials apart, thereby enabling the design of a compact structure; a method for manufacturing the same; and a method for adhering base materials together. [Solution] A laminate body comprising: a structure in which (S1) a first fabric- or sheet-like base material and (S2) a second fabric- or sheet-like base material are adhered together by (A) an adhesive layer in which two or more types of curable adhesive compositions, one having 2 to 5 times more stress at 10 mm elongation in a stress-strain curve when cured, are applied in parallel to each other and integrated with each other; a method for manufacturing the same; and the like.