Polyolefin Resin Adhesion to Polyester via Tin Oxide Catalyst

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Solution Overview

Problem

Polyester films, such as PET, face challenges in achieving good adhesion with polyolefin films during coextrusion or extrusion lamination due to their poor compatibility, leading to adhesive failure, especially in oriented film structures, and existing solutions like primers or tie-layers are not effective or environmentally friendly.

Innovation Solution

A resin comprising a polyolefin grafted with functional groups like ethylenically unsaturated carboxylic acid or carboxylic acid anhydride, combined with a tin oxide-based catalyst, which enhances adhesion between polyolefin and polyester films by improving polymer-polymer coupling during coextrusion or extrusion lamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a primer is used to improve adhesion between PET and polyolefin films, then adhesion is improved, but manufacturing complexity and cost increase due to additional drying steps

Engineering Contradiction:
ImproveadhesionVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the adhesion-promoting function from a separate primer layer and integrates it directly into the polyolefin resin through grafting functional groups (carboxylic acid, anhydride, or hydroxyl groups). This eliminates the need for a separate primer application and drying step, resolving the contradiction between achieving good adhesion and maintaining simple manufacturing processes.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent combines multiple functions into a single resin component: the polyolefin provides polyolefin-polyolefin adhesion, while the grafted functional groups provide polyester-polyolefin adhesion. This merging of adhesion functions into one material eliminates the need for separate primer layers and their associated manufacturing steps.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a primer is used to improve adhesion between PET and polyolefin films, then adhesion is improved, but manufacturing cost increases due to additional manufacturing steps

Engineering Contradiction:
ImproveadhesionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the need for separate primer materials and their associated costs by integrating adhesion-promoting functional groups directly into the polyolefin resin structure through grafting, thereby eliminating material and processing costs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The modified polyolefin resin serves multiple functions simultaneously: it acts as the bonding polymer providing polyolefin-polyolefin adhesion while the grafted functional groups (carboxylic acid, anhydride, or hydroxyl) provide polyester-polyolefin adhesion, eliminating the need for separate primer materials and reducing overall manufacturing costs.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If certain primers are used to improve adhesion, then adhesion is improved, but environmental friendliness deteriorates

Engineering Contradiction:
ImproveadhesionVSAvoidenvironmental impact
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical parameters of the polyolefin resin by grafting functional groups (carboxylic acid, anhydride, or hydroxyl) onto the polyolefin backbone. This chemical modification enables direct chemical bonding with polyester surfaces, achieving strong adhesion without requiring environmentally harmful primer substances.

Inventive Principle:
Principle #35Parameter changes

4Ease of manufacture

If conventional polyolefin resin is used, then manufacturing simplicity is maintained, but adhesion to polyester deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidadhesion
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent modifies the chemical parameters of the polyolefin resin by grafting functional groups (carboxylic acid, anhydride, or hydroxyl) onto the polyolefin chains. This chemical modification enables direct chemical bonding with polyester surfaces, achieving strong adhesion while maintaining manufacturing simplicity because the modified resin is processed using standard extrusion and lamination techniques without additional process steps.

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 significantly improves the adhesion between polyolefin and polyester films, reducing adhesive failure and eliminating the need for additional costly manufacturing steps or environmentally unfriendly primers, while maintaining the structural integrity of the films.

Implementation Method 1

a tin oxide-based catalyst, where the resin includes 0.2 wt.% to 1.5 wt.% of the functional group from the first polyolefin

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentEP3810692B1Resin having a catalyst for reactive adhesion to a polyester
Publication Date: 2024.04.24 DOW GLOBAL TECHNOLOGIES LLC
  • EP3810692B1 patent drawingFigure 1
  • EP3810692B1 patent drawingFigure 2
  • EP3810692B1 patent drawingFigure 3

AI summary

A resin including up to 99.99 weight percent (wt.%) of a first polyolefin grafted with a functional group selected from an ethylenically unsaturated carboxylic acid, a carboxylic acid anhydride, an ester functional group or a combination thereof; and 0.01 to 3.0 wt.% of a tin oxide-based catalyst, where the resin includes 0.2 wt.% to 1.5 wt.% of the functional group from the first polyolefin, the wt.% based on a total weight of the resin. The first polyolefin can be selected from a polyethylene, a polypropylene, an ethylene/alpha-olefin copolymer, a propylene/alpha-olefin copolymer and combinations thereof. The tin oxide-based catalyst can be selected from dibutyltin oxide, dioctyltin oxide and combinations thereof. The resin can be used in a multilayer structure, where a Layer A comprises the resin and a Layer B comprises a polyester, where a first major surface of Layer A is in adhering contact with the second major surface of Layer B.