Functionalized Particle Crosslinked Pressure Sensitive Adhesive

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Solution Overview

Problem

Pressure-sensitive adhesives (PSAs) face challenges in achieving a balance between good product properties and processability, particularly in solvent-free systems, where crosslinking can lead to increased elasticity and reduced flowability, making coating and processing difficult.

Innovation Solution

The use of functionalized organic particles with blocked or protected functionalities, which are specifically designed for thermal crosslinking, allowing for the formation of covalent bonds with polymers during or after coating, using thermal energy, radiation, or sound energy, to create a crosslinked PSA with improved cohesion and processing properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If crosslinking is performed to improve cohesion and product properties, then adhesive strength and cohesion are improved, but elasticity increases and flowability decreases, making coating and processing difficult

Engineering Contradiction:
ImprovecohesionVSAvoidflowability
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent applies preliminary action by incorporating crosslinkable functional groups into the polymer structure before the coating process. These groups remain dormant during application and only activate after coating through exposure to specific conditions (moisture, heat, or radiation), allowing the adhesive to be applied in a flowable state and then develop enhanced cohesion subsequently.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamics by creating a time-dependent transformation of the adhesive properties. The adhesive transitions from a processable, flowable state during application to a crosslinked, high-cohesion state after application. This dynamic property change is achieved through conditional activation of crosslinking mechanisms that respond to environmental triggers after coating.

Inventive Principle:
Principle #15Dynamics

2Strength

If high molecular weight polymers are used to improve cohesion, then adhesive strength is improved, but viscosity increases and processing becomes more difficult

Engineering Contradiction:
Improveadhesive strengthVSAvoidprocessing
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent uses preliminary action by pre-equipping polymers with crosslinkable functional groups at moderate molecular weights. These functional groups enable post-application crosslinking that develops full adhesive strength without requiring the polymers to have high molecular weights from the outset, thereby maintaining processability during manufacturing and application.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by transforming the adhesive from a moderate-strength, low-viscosity state during processing to a high-strength state after crosslinking. This parameter transformation allows the use of lower molecular weight polymers that are easier to process, while achieving the desired adhesive strength through chemical crosslinking after application.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If solvent-free systems are used to improve environmental compatibility and processing speed, then eco-friendliness and productivity are improved, but crosslinking occurs too quickly and pot life is reduced

Engineering Contradiction:
Improveprocessing speedVSAvoidpot life
Core Design Contradiction:
ProductivityVSDuration of action of moving object

Solution Approach 1:

The patent applies preliminary action by incorporating stable, dormant crosslinkable functional groups into the adhesive formulation that do not react during storage and processing. These groups remain inactive until exposed to specific activation conditions (moisture, heat, or radiation) after application, thereby extending pot life while enabling rapid crosslinking and high productivity once applied.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamics by creating a conditional reactivity system where the crosslinking reaction is switched from inactive to active state after application. This dynamic control allows the adhesive to maintain stability during processing (long pot life) and then rapidly crosslink when exposed to activation conditions, achieving both extended pot life and high processing speed.

Inventive Principle:
Principle #15Dynamics

4Strength

If chemical crosslinking is performed to improve cohesion, then adhesive strength is improved, but the material becomes less flexible and cannot adapt adequately to substrate roughness

Engineering Contradiction:
ImprovecohesionVSAvoidflexibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by incorporating flexible polymer backbones with attached crosslinkable functional groups. The flexible backbone structure is established before crosslinking, and the crosslinking is performed in a controlled manner that preserves this flexibility. This allows the adhesive to maintain adaptability to substrate roughness while developing enhanced cohesion through crosslinking.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements composite materials by combining flexible polymer chains with crosslinkable functional groups. The resulting structure is a composite of flexible segments (polymer backbone) and crosslinked segments (functional group networks), creating a material that exhibits both flexibility for substrate adaptation and high cohesion from the crosslinked structure.

Inventive Principle:
Principle #40Composite materials

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 approach enables the production of PSAs with increased pot life and improved processing behavior, including enhanced cohesion and adhesive strength, while maintaining good coatability and reducing the need for high molecular weight polymers, resulting in self-adhesive products with superior performance.

Implementation Method 1

using thermal energy, radiation, or sound energy

Methodology Applied
Scientific EffectThermal energy absorption: Absorption (EM radiation)

Implementation Method 2

using thermal energy, radiation, or sound energy

Methodology Applied
Scientific EffectRadiation absorption: Absorption (EM radiation)

Implementation Method 3

using thermal energy, radiation, or sound energy

Methodology Applied
Scientific EffectSound energy absorption: Absorption (EM radiation)

Implementation Method 4

formation of covalent bonds with polymers during or after coating

Methodology Applied
Scientific EffectCovalent bonding: Chemical Bonding

Data Source

PatentEP2143773B1Adhesive masses and method for their manufacture
Publication Date: 2011.04.27 TESA SE
  • EP2143773B1 patent drawingFigure 1~3
  • EP2143773B1 patent drawingFigure 4~5
  • EP2143773B1 patent drawingFigure 6

AI summary

Preparation of dispersion- or hot melt-pressure sensitive adhesive mass comprising a crosslinking product from a polymer and a variety of functionalized particles, comprises: converting a part of the functional groups Z of the particles into functional groups X by energy input, in such a position and under appropriate conditions for the reaction with the reactive centers of the polymer; and forming the crosslinking product comprising the reaction of the functional groups X of the particles with the reactive centers of the polymer under appropriate process conditions. Preparation of a dispersion- or hot melt-pressure sensitive adhesive mass comprising the crosslinking product from at least a polymer and at least a variety of functionalized particles, comprises: converting at least a part of the functional groups Z of the particles into functional groups X by energy input, in such a a position and under appropriate process conditions for the reaction with the reactive centers of the polymer; and forming the crosslinking product comprising the reaction of the functional groups X of the particles with the reactive centers of the polymer under the appropriate process conditions, where the polymer has reactive centers, the functionalized particles exhibit a polymer base unit, the polymer base unit based on monomers comprises at least a monomer variety, the monomers exhibit at least a type of functional group Z, that does not react with the reactive centers of the polymer under the conditions of the production and processing of the polymer and/or crosslinked pressure sensitive adhesive. Independent claims are included for: (1) the pressure sensitive adhesive mass based on the polymer and functionalized particles, where the crosslinking of the polymer component is at least partly caused by the incorporation of functionalized particles, and the functional groups Z are converted into X groups in a position to react with functional groups Y1 present in the polymer component; and (2) a polymer mixture comprising the polymer and functionalized particles, where the reactive centers of the polymer comprises functional groups Y1.