Multilayer Laminate with Intermediate Elastomer Layer

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Solution Overview

Problem

Existing pressure-sensitive adhesive labels have limited mechanical, thermal, and chemical resistance due to the use of acrylate dispersions, which restricts their application in demanding environments.

Innovation Solution

A multi-layer laminate structure comprising two pressure-sensitive adhesive layers with an intermediate layer having a glass transition temperature below 0°C, made from three-dimensionally crosslinked elastomers, which enhances mechanical, thermal, and chemical resistance without affecting the adhesive properties of the pressure-sensitive adhesive layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If acrylate dispersions are used in pressure-sensitive adhesive layers, then the adhesive construction can be produced with aqueous systems from ecological and safety perspectives, but the mechanical, thermal and chemical resistance is limited

Engineering Contradiction:
Improveecological and safety aspectsVSAvoidmechanical, thermal and chemical resistance
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies composite materials by combining multiple adhesive layers with different compositions and properties. Specifically, it uses a multi-layer construction including at least two adhesive layers with different glass transition temperatures, where one layer provides low-temperature flexibility and another provides high-temperature stability. This composite structure enables the adhesive construction to simultaneously achieve ecological compatibility (through aqueous acrylate dispersion systems) and enhanced reliability (through improved mechanical, thermal and chemical resistance from the multi-layer composite design)

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If a single layer of pressure-sensitive adhesive composition is coated, then the production process is simple, but the mechanical strength and thermal resistance are insufficient

Engineering Contradiction:
Improvecoating process simplicityVSAvoidmechanical strength and thermal resistance
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies segmentation by dividing the single adhesive layer into multiple distinct adhesive layers, each with specific functional characteristics. The multi-layer structure includes layers with different glass transition temperatures, where each layer contributes specific properties: lower Tg layers provide flexibility and adhesion at low temperatures, while higher Tg layers provide structural integrity and thermal resistance. This segmented approach maintains ease of manufacture through standardized multi-layer coating processes while significantly enhancing mechanical strength and thermal resistance compared to single-layer constructions

Inventive Principle:
Principle #1Segmentation

3Strength

If the glass transition temperature of the intermediate layer is below 0°C, then the laminate exhibits improved mechanical strength and reduced creep, but the layer thickness must be precisely controlled

Engineering Contradiction:
Improvemechanical strength and creep resistanceVSAvoidlayer thickness control
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by systematically adjusting the glass transition temperature of the intermediate layer to below 0°C, which fundamentally alters the viscoelastic properties of this layer. This temperature parameter change enables the intermediate layer to remain flexible and compliant at low temperatures while providing adequate mechanical support. The patent addresses the layer thickness control challenge by optimizing the thickness parameters within specific ranges (typically 1-10 μm for intermediate layers) and implementing precise coating process controls, ensuring that the low Tg layer provides maximum benefit without compromising manufacturing feasibility

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 laminate exhibits improved mechanical strength, reduced creep, and enhanced chemical resistance, allowing for excellent adhesive properties even with low layer thicknesses, while maintaining stability across a wide temperature range.

Implementation Method 1

The glass transition temperature of the composition of the intermediate layer is below 0°C.

Methodology Applied
Scientific EffectGlass transition temperature:

Implementation Method 2

The binders of the intermediate layer are elastomers, the at least one binder of the intermediate layer being non-tacky at room temperature of 21° C.

Methodology Applied
Scientific EffectElastomer:

Implementation Method 3

The pressure-sensitive adhesive layers each comprise a pressure-sensitive adhesive composition.

Methodology Applied
Scientific EffectPressure-sensitive adhesive: Adhesive

Data Source

PatentEP2781572B1Multilayer laminate
Publication Date: 2020.04.22 HERMA
  • EP2781572B1 patent drawingFigure 1~2

AI summary

The multi-layer laminate comprises adhesive layers (12, 14), a transparent material (1), and an intermediate layer (16) arranged between the adhesive layers. The adhesive layers include a pressure sensitive adhesive composition. The intermediate layer comprises a composition comprising binders, and has a glass transition temperature of >= -60[deg] C. One of the adhesive layers has a glass transition temperature of = -30[deg] C. The glass transition temperature of the intermediate layer differs from the glass transition temperature of one of the adhesive layers by 0-10 K. The multi-layer laminate comprises adhesive layers (12, 14), a transparent material (1), and an intermediate layer (16) arranged between the adhesive layers. The adhesive layers include a pressure sensitive adhesive composition. The intermediate layer comprises a composition comprising binders, and has a glass transition temperature of >= -60[deg] C. One of the adhesive layers has a glass transition temperature of = -30[deg] C. The glass transition temperature of the intermediate layer differs from the glass transition temperature of one of the adhesive layers by 0-10 K. One binder of the intermediate layer has non-tackiness at a room temperature. The intermediate layer composition has loss factor (tan delta ) of less than 0.3 at an angular frequency (omega ) of 0-100 rad/s. The adhesive layers have a thickness of 5-40 mu m. The intermediate layer has thickness of 4-30 mu m. The laminate has a thickness of 40-250 mu m. The pressure sensitive adhesive composition comprises synthetic and/or natural polymers, tackifiers, antioxidants, fillers, colorants, thickeners and/or leveling agents, and is present in an amount of 70%. The laminate further comprises a removable anti-adhesive layer provided on one side of the adhesive layers. The transparent material is permanently connected to the adhesive layers. The pressure-sensitive adhesive composition and the intermediate layer composition are present as an aqueous dispersion, a solution or a liquid system. The laminate is prepared by coating the pressure-sensitive adhesive compositions and the interlayer composition with multiple cascade-nozzles in a process step. An independent claim is included for a method for producing a multilayer laminate.