Tie Layer Resin Composition for Multilayer Film Adhesion

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Solution Overview

Problem

Current tie layer formulations in multilayer films lack sufficient adhesion strength and toughness, leading to compatibility issues between different polymer layers, particularly with polyethylene and polyamide or ethylene vinyl alcohol layers, which restricts the reduction of film thickness and increases material costs.

Innovation Solution

Development of a resin composition comprising an ethylene-based polymer with a MWCDI value greater than 0.9 and a specific melt index ratio, combined with maleic anhydride grafted polyethylene, to enhance adhesion and toughness, allowing for reduced thickness of multilayer structures and potential cost savings by minimizing the use of engineering polymers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional tie layer formulations are used, then adhesion between polymer layers is achieved, but adhesion strength and toughness are insufficient

Engineering Contradiction:
Improveadhesion strengthVSAvoidtie layer performance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies parameter changes by carefully controlling the molecular weight distribution (MWCDI > 0.9) and melt index ratio (110/12 ≥ 7.0 - 1.2 x log(12)) of the ethylene-based polymer, along with the maleic anhydride grafting level (0.5-5 wt%), to optimize both adhesion strength and toughness of the tie layer

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining ethylene-based polymer with maleic anhydride grafted polyethylene, creating a composite resin composition that leverages the complementary properties of both components to achieve superior adhesion and toughness

Inventive Principle:
Principle #40Composite materials

2Reliability

If tie layer with sufficient adhesion and toughness is used, then compatibility between polyethylene and polyamide/EVOH layers is improved, but film thickness cannot be reduced

Engineering Contradiction:
Improvelayer compatibilityVSAvoidfilm thickness
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent uses parameter changes in the resin composition (MWCDI, melt index ratio, grafting level) to achieve such high adhesion and toughness that the tie layer can be made thinner while maintaining or improving overall layer compatibility and performance

Inventive Principle:
Principle #35Parameter changes

3Reliability

If engineering polymers are used in multilayer structures, then required performance is achieved, but material costs increase

Engineering Contradiction:
ImproveperformanceVSAvoidmaterial cost
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies parameter changes to create a cost-effective resin composition using primarily ethylene-based polymer with controlled molecular weight distribution and maleic anhydride grafting, providing engineering polymer-level performance at lower material cost

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 resin composition significantly improves adhesion and toughness, enabling the reduction of overall thickness in multilayer structures and reducing the amount of engineering polymers required, while maintaining or enhancing puncture strength and dart impact resistance.

Implementation Method 1

a maleic anhydride grafted polyethylene comprising a maleic anhydride grafted high density polyethylene, a maleic anhydride grafted linear low density polyethylene, or a maleic anhydride grafted polyethylene elastomer

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentEP3519181B9Resins for use as tie layers in multilayer films and multilayer films comprising the same
Publication Date: 2022.09.28 DOW GLOBAL TECHNOLOGIES LLC
  • EP3519181B9 patent drawingFigure 1~2
  • EP3519181B9 patent drawingFigure 3~4
  • EP3519181B9 patent drawing

AI summary

The present disclosure provides resins that can be used as a tie layer in a multilayer structure and to multilayer structures comprising one or more tie layers formed from such resins. In one aspect, a resin for use as a tie layer in a multilayer structure comprises a first composition, wherein the first composition comprises at least one ethylene-based polymer and wherein the first composition comprises a MWCDI value greater than 0.9, and a melt index ratio (I10/I2) that meets the following equation: I10/I2 ? 7.0 - 1.2 x log (I2), wherein the first composition comprises 1 to 99 weight percent of the resin; and a maleic anhydride grafted polyethylene comprising a maleic anhydride grafted high density polyethylene, a maleic anhydride grafted linear low density polyethylene, a maleic anhydride grafted polyethylene elastomer, or a combination thereof, wherein the maleic anhydride grafted polyethylene comprises 1 to 99 weight percent of the resin.