Acrylic PSA Composition With Polyhydrazide Crosslinking Balance

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Solution Overview

Problem

Existing pressure sensitive adhesive (PSA) products either have good adhesion but unsatisfactory cohesion, or vice versa, lacking a balanced adhesion and cohesion performance.

Innovation Solution

A pressure sensitive adhesive composition comprising a polymer derived from a specific monomer mixture, including C6-C10 alkyl acrylate, methyl (meth)acrylate, an ethylenically unsaturated compound with keto or aldehyde groups, and a polyhydrazide compound for crosslinking, which reacts with these groups to enhance adhesion and cohesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If pressure sensitive adhesive products use conventional copolymers crosslinked with dihydrazide crosslinker, then adhesion may be good, but cohesion is not satisfactory

Engineering Contradiction:
ImprovecohesionVSAvoidadhesion
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the adhesive composition by incorporating specific functional monomers (keto or aldehyde groups) that react with polyhydrazide crosslinkers to form different crosslinking structures, thereby adjusting the balance between adhesion and cohesion properties

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite adhesive system combining polymer chains with embedded reactive functional groups (keto or aldehyde) and polyhydrazide crosslinkers, forming a multi-component system that achieves both good adhesion and cohesion through synergistic interactions

Inventive Principle:
Principle #40Composite materials

2Strength

If pressure sensitive adhesive products use conventional copolymers crosslinked with dihydrazide crosslinker, then cohesion may be good, but adhesion is not satisfactory

Engineering Contradiction:
ImproveadhesionVSAvoidcohesion
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent adjusts the chemical composition parameters by incorporating controlled amounts of keto or aldehyde functional monomers (0.1-5 wt%) that create specific crosslinking densities, thereby optimizing the balance between adhesion strength and cohesive reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent develops a composite adhesive formulation that integrates polymer matrix with reactive functional groups and polyhydrazide crosslinkers, creating a heterogeneous structure that simultaneously provides good adhesion to substrates and cohesive strength within the adhesive layer

Inventive Principle:
Principle #40Composite materials

3Reliability

If pressure sensitive adhesive products aim for balanced adhesion and cohesion, then performance is improved, but formulation complexity increases

Engineering Contradiction:
Improvebalanced adhesion and cohesionVSAvoidformulation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent simplifies the formulation process by establishing specific parameter ranges for functional monomers (0.1-5 wt%) and crosslinkers (0.01-2 wt%) that automatically achieve balanced adhesion and cohesion when followed, reducing the need for complex trial-and-error formulation approaches

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses keto or aldehyde functional groups as intermediary reactive sites that mediate between the polymer matrix and polyhydrazide crosslinkers, creating a controlled crosslinking process that simplifies formulation while achieving balanced performance

Inventive Principle:
Principle #24Intermediary (Mediator)

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 composition achieves improved adhesion and cohesion, or a balanced adhesion/cohesion performance, as demonstrated by enhanced peel strength and shear resistance in various tests.

Implementation Method 1

B) a polyhydrazide compound having at least two hydrazide functional groups which react with the keto or aldehyde groups by a crosslinking reaction

Methodology Applied
Scientific EffectCrosslinking reaction: Chemical Bonding

Data Source

PatentEP3999606B1Acrylic adhesive composition
Publication Date: 2026.03.04 ROHM & HAAS CO

AI summary

Disclosed is an acrylic adhesive composition comprising: A) a polymer polymerized from a monomer mixture comprising (a) 40-90 wt% of C 6-C 10 alkyl acrylate; (b) 3-15 wt% of methyl (meth)acrylate; (c) 0.1-5 wt% of an ethylenically unsaturated compound having at least one keto or aldehyde group; (d) 0-2 wt% of an ethylenically unsaturated acid; (e) 0-30wt% of other ethylenically unsaturated monomers; wherein the percentages are based on the total weight of the monomer mixture; and B)a polyhydrazide compound having at least two hydrazide functional groups which react with the keto or aldehyde groups by a crosslinking reaction.