Poly(meth)acrylate Adhesive Mass for Rough Surface Wetting

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Solution Overview

Problem

Existing adhesive tapes face challenges in achieving strong, permanent, and weather-resistant adhesion on various surfaces, particularly on rough or non-polar substrates like car paints, while maintaining good wetting properties and avoiding mechanical stress-induced degradation.

Innovation Solution

The use of a poly(meth)acrylate-based adhesive mass with a specific monomer composition, including a mixture of simply branched and linear alcohol components, which is thermally networked using epoxycyclyl derivatives without accelerators, to enhance adhesion and cohesion while maintaining good wetting properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the adhesive tape is made thick to achieve strong adhesion, then the adhesive strength increases, but the wetting capability deteriorates

Engineering Contradiction:
Improveadhesive strengthVSAvoidwetting capability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the adhesive by using specific monomer ratios (2-propylheptyl acrylate: 55-75 wt.%, linear alcohol component: 20-40 wt.%, acrylic acid: 5-15 wt.%) to optimize both thickness tolerance and wetting capability simultaneously

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The adhesive uses a composite polymer structure combining branched and linear alcohol components in a specific ratio, creating a material that exhibits both the cohesion needed for thick tape strength and the flowability required for good wetting on rough surfaces

Inventive Principle:
Principle #40Composite materials

2Strength

If the adhesive is highly cross-linked to improve cohesion, then the cohesive strength increases, but the wetting capability deteriorates

Engineering Contradiction:
Improvecohesive strengthVSAvoidwetting capability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent controls the cross-linking degree by adjusting the acrylic acid content (5-15 wt.%) and using specific cross-linking agents, achieving sufficient cohesion while preserving the flowability needed for wetting

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The adhesive exhibits different properties at different locations: the cross-linked network provides cohesion in the bulk material, while the unreacted monomers and oligomers maintain flowability at the interface for effective wetting

Inventive Principle:
Principle #3Local quality

3Strength

If the adhesive is highly viscous to improve cohesion, then the cohesive strength increases, but the wetting capability deteriorates

Engineering Contradiction:
Improvecohesive strengthVSAvoidwetting capability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent optimizes the viscosity by selecting specific monomer combinations and ratios, creating an adhesive that is viscous enough for cohesion but fluid enough to flow and wet rough surfaces effectively

Inventive Principle:
Principle #35Parameter changes

4Strength

If the adhesive is applied to rough surfaces to improve adhesion, then the adhesion strength increases, but the wetting uniformity deteriorates

Engineering Contradiction:
Improveadhesion strengthVSAvoidwetting uniformity
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent modifies the adhesive flow characteristics by adjusting the monomer composition to enable uniform penetration and distribution across rough surfaces while maintaining consistent adhesion properties

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The adhesive exhibits dynamic flow behavior, adapting its viscosity and flow characteristics during application to ensure uniform wetting of rough surfaces while maintaining sufficient cohesion for strong adhesion

Inventive Principle:
Principle #15Dynamics

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 solution achieves high adhesive forces and excellent wetting behavior on diverse surfaces, including metals and plastics, while maintaining stability under mechanical stress and varying temperatures, thus providing strong, permanent, and weather-resistant adhesion.

Implementation Method 1

The viscous flow component is necessary to achieve adhesion. Only the viscous components, caused by macromolecules with relatively high mobility, enable good wetting and flow onto the substrate to be bonded.

Methodology Applied
Scientific EffectViscous flow: Viscometer

Implementation Method 2

The proportional elastic restoring forces are necessary to achieve cohesion. They are caused, for example, by very long-chain and highly entangled macromolecules, as well as by physically or chemically cross-linked macromolecules, and enable the transfer of forces acting on an adhesive bond.

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

The term 'wetting' thus describes the ability of a pressure-sensitive adhesive to compensate for unevenness and to displace air between itself and the substrate.

Methodology Applied
Scientific EffectWetting: Wetting

Data Source

PatentEP3228673B1Adhesive mass
Publication Date: 2025.04.02 TESA SE
  • EP3228673B1 patent drawingFigure 1~2b
  • EP3228673B1 patent drawingFigure 3
  • EP3228673B1 patent drawing

AI summary

The aim is to provide a high-performance pressure-sensitive adhesive characterized by good wetting and dewetting properties on surfaces with different surface energies. This is achieved with a pressure-sensitive adhesive containing at least 50 wt.%, based on the total weight of the adhesive, of at least one polymer A, which can be traced back to the following monomer composition: a1) 55 to 75 wt.% of at least one (meth)acrylic acid ester with a glass transition temperature of the homopolymer of at most -60 °C, the alcohol component of which is a branched primary alcohol with an iso-index of 1; a2) 20 to 40 wt.% of at least one (meth)acrylic acid ester, the alcohol component of which is a linear C1C18 alcohol; a3) 5 to 15 wt.% acrylic acid. The pressure-sensitive adhesive according to the invention exhibits particularly good properties in combination with a foamed carrier.The invention therefore also relates to an adhesive tape comprising a foamed carrier and an adhesive compound according to the invention.