Aluminum Packaging Laminate Silication Adhesion

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Solution Overview

Problem

Current packaging laminates face challenges in achieving sufficient adhesion between aluminum and polyolefin layers, especially under sterilization conditions, due to restrictions on adhesives and surface treatments, and the need for enhanced sterilization resistance and corrosion protection.

Innovation Solution

The use of a modified surface layer produced by silicatization or titanation on the aluminum carrier layer, combined with a suitable adhesive and polyolefin film, and optionally a primer or lacquer layer, to enhance bonding and corrosion resistance, while meeting safety regulations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional adhesives (e.g., epoxy resin-based) are used to bond aluminum carrier layer and polyolefin layer, then initial adhesion is achieved, but adhesion strength deteriorates after sterilization process

Engineering Contradiction:
Improveadhesion strengthVSAvoidsterilization resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention changes the chemical composition parameters of the adhesive layer by specifying precise ranges of functional groups (carboxyl: 0.5-5 mmol/g, hydroxyl: 0.5-5 mmol/g, amine: 0.1-2 mmol/g) to achieve optimal adhesion strength that withstands sterilization conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite adhesive system combining multiple functional groups (carboxyl, hydroxyl, amine) within the same adhesive layer to simultaneously achieve strong initial adhesion and maintain reliability after sterilization through complementary chemical interactions with the aluminum carrier layer

Inventive Principle:
Principle #40Composite materials

2Strength

If traditional surface treatments (flame treatment, corona treatment, chromating) are applied to aluminum carrier layer, then adhesion is improved, but compliance with food safety regulations deteriorates

Engineering Contradiction:
Improveadhesion strengthVSAvoidfood safety compliance
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and eliminates harmful substances (chromium compounds, bisphenol-A) from the adhesive and surface treatment system while retaining the essential adhesion function through alternative safe chemical compositions

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a safe intermediary adhesive layer with specific functional groups that mediates the bonding between aluminum carrier layer and polyolefin layer without requiring hazardous surface treatments, thus maintaining food safety compliance

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If adhesive layer composition is optimized for maximum adhesion, then bond strength is improved, but complexity of adhesive formulation increases

Engineering Contradiction:
Improveadhesion strengthVSAvoidadhesive formulation complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention simplifies the formulation complexity by defining specific parameter ranges for functional groups (carboxyl: 0.5-5 mmol/g, hydroxyl: 0.5-5 mmol/g, amine: 0.1-2 mmol/g) that can be achieved through standard polymer modification techniques, making the complex adhesive system manufacturable

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

This approach significantly improves adhesion strength between aluminum and polyolefin layers, maintaining bond integrity after sterilization and exposure to fillings, and provides enhanced corrosion protection without using hazardous substances, making the laminate suitable for deep-drawn packaging trays.

Implementation Method 1

the surface of the carrier layer facing the adhesive layer or the coupling agent layer having a modified surface layer produced by silicatization or titanation

Methodology Applied
Scientific EffectSilicatization:

Implementation Method 2

the surface of the carrier layer facing the adhesive layer or the coupling agent layer having a modified surface layer produced by silicatization or titanation

Methodology Applied
Scientific EffectTitanation:

Implementation Method 3

an adhesive layer or coupling agent layer, the surface of the carrier layer facing the adhesive layer

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 4

the modified surface layer above all increases the anchoring of the adhesive layer to the aluminum of the carrier layer

Methodology Applied
Scientific EffectSurface modification:

Data Source

PatentEP3439867B1Packaging laminate with a carrier coating and a polyolefine coating
Publication Date: 2020.06.03 CONSTANTIA TEICH GMBH
  • EP3439867B1 patent drawingFigure 1~2
  • EP3439867B1 patent drawingFigure 3~5

AI summary

The invention relates to a packaging laminate (1) having a carrier layer (2) made of aluminum and a polyolefin layer (3) having high interlayer adhesion, which is connected to the carrier layer via an adhesive layer (4) or an adhesion promoter layer (8). According to the invention, it is provided that the surface of the carrier layer (2), which faces the adhesive layer (4) or the adhesion promoter layer (8), comprises a modified surface layer (5) produced by silicatization or titanization.