Adhesive Sheet with Elastic Microspheres for Rough Surface Application

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Solution Overview

Problem

Adhesive sheets struggle to maintain a smooth appearance and sufficient adhesive force on both rough and smooth surfaces, such as mortar, concrete, siding board, stucco, wallpaper, metal plates, and resin films, while preserving the quality of graphic images.

Innovation Solution

An adhesive sheet comprising a rigid resin film with a first pressure-sensitive adhesive layer containing elastic resin microspheres having a volume average particle diameter of 110 micrometers or greater and a tacky binder, creating an uneven surface that adheres to both smooth and rough surfaces, with the rigid resin film preventing deformation and maintaining a smooth appearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a flexible adhesive sheet is used to conform to rough surfaces, then adhesion to rough surfaces improves, but the appearance smoothness deteriorates

Engineering Contradiction:
Improveadhesion to rough surfaceVSAvoidappearance smoothness
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The adhesive layer is segmented into multiple functional components: elastic resin microspheres (providing conformability to rough surfaces), tacky binder (providing adhesion), and rigid resin film (providing structural support). This segmentation allows each component to perform its specific function without compromising the others, resolving the contradiction between rough surface adhesion and appearance smoothness

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses a composite adhesive layer combining elastic resin microspheres with tacky binder, supported by a rigid resin film. This composite structure enables the adhesive sheet to simultaneously achieve conformability to rough surfaces through the elastic microspheres while maintaining appearance smoothness through the rigid film's dimensional stability

Inventive Principle:
Principle #40Composite materials

2Shape

If a rigid adhesive sheet is used to maintain appearance smoothness, then appearance smoothness improves, but adhesion to rough surfaces deteriorates

Engineering Contradiction:
Improveappearance smoothnessVSAvoidadhesion to rough surface
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

Different parts of the adhesive sheet have different properties: the adhesive layer contains soft elastic microspheres for conformability, while the rigid resin film provides overall structural rigidity. This local quality differentiation allows the sheet to be rigid enough to maintain appearance smoothness while the adhesive layer can still conform to rough surfaces for good adhesion

Inventive Principle:
Principle #3Local quality

3Reliability

If elastic resin microspheres with large particle diameter are used to enhance adhesion to rough surfaces, then adhesion to rough surfaces improves, but the uniformity of adhesive layer deteriorates

Engineering Contradiction:
Improveadhesion to rough surfaceVSAvoiduniformity of adhesive layer
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention specifies a particular particle diameter range (110 micrometers or greater) for the elastic resin microspheres. This parameter optimization ensures the microspheres are large enough to bridge rough surface irregularities for good adhesion, yet small enough to maintain reasonable uniformity in the adhesive layer when properly dispersed with the tacky binder

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 sheet achieves high adhesive force and a smooth appearance on various surfaces by utilizing the elastic microspheres and rigid resin film, ensuring effective adhesion and ease of application without deformation.

Implementation Method 1

a first pressure sensitive adhesive layer which is disposed on or above a surface of the rigid resin film, wherein the first pressure sensitive adhesive layer includes elastic resin microspheres

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a first pressure sensitive adhesive layer including elastic resin microspheres having a volume average particle diameter of 110 micrometers or greater and a tacky binder

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3609968B1Adhesive sheet and method of applying adhesive sheet to rough surface
Publication Date: 2025.06.25 3M INNOVATIVE PROPERTIES CO
  • EP3609968B1 patent drawingFigure 1A~1B
  • EP3609968B1 patent drawingFigure 2~3
  • EP3609968B1 patent drawingFigure 4~5

AI summary

An adhesive sheet of an embodiment of the present disclosure is an adhesive sheet including: a rigid resin film having a thickness of 80 micrometers to 500 micrometers, and a first pressure sensitive adhesive layer being disposed on or above a surface of the rigid resin film, wherein the first pressure sensitive adhesive layer includes elastic resin microspheres having a volume average particle diameter of 110 micrometers or greater and a tacky binder, and the first pressure sensitive adhesive layer has an uneven surface due to the presence of the microspheres.