Multilayer Packaging Structure with Phosphorus-Polymer Adhesion Layer

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Solution Overview

Problem

Conventional multilayer structures used in packaging materials and electronic device protective sheets suffer from decreased interlayer adhesion and gas barrier properties when exposed to physical stresses, such as deformation and high temperature/high humidity conditions, leading to appearance defects like delamination.

Innovation Solution

A multilayer structure comprising a base, a layer containing a phosphorus atom compound and a polymer with hydroxy or carboxyl groups, and an aluminum layer, where the mass ratio of the compound to the polymer is between 15:85 to 99:1, and the aluminum layer is formed through a reaction product of a metal oxide and a phosphorus compound, ensuring high performance and adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional multilayer structure with aluminum or aluminum oxide barrier layer is used, then initial gas barrier properties are good, but interlayer adhesion decreases under harsh conditions (high temperature and high humidity) leading to delamination

Engineering Contradiction:
Improvegas barrier propertiesVSAvoidinterlayer adhesion
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention uses a composite layer (Y) containing both phosphorus compound particles and polymer particles, rather than a single material. This composite structure provides both gas barrier properties and adhesion to the aluminum layer, resolving the contradiction between maintaining gas barrier performance and preventing delamination under harsh conditions.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The phosphorus compound particles act as an intermediary between the aluminum layer and the polymer matrix. They chemically react with the aluminum layer to form strong bonds while being embedded in the polymer matrix that provides flexibility and adhesion, thus mediating between the requirements for gas barrier performance and interlayer adhesion.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If a conventional multilayer structure is used for retort packaging, then it provides basic protection, but it undergoes delamination and appearance defects after retorting

Engineering Contradiction:
Improveresistance to retorting conditionsVSAvoidappearance quality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The phosphorus compound particles are pre-applied to the aluminum layer before the polymer coating is formed. This preliminary action allows the phosphorus compounds to chemically bond with the aluminum surface, creating a strong adhesive interface that prevents delamination during subsequent retorting processes and maintains appearance quality.

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If the aluminum layer is made thinner to reduce material usage, then cost and weight decrease, but gas barrier properties become insufficient under physical stresses

Engineering Contradiction:
Improvealuminum layer thicknessVSAvoidgas barrier properties
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The composite layer (Y) with phosphorus compound particles and polymer particles creates a synergistic structure where the phosphorus compounds provide enhanced gas barrier properties through their molecular structure, allowing the aluminum layer to be thinner while maintaining sufficient gas barrier performance under physical stresses.

Inventive Principle:
Principle #40Composite materials

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 multilayer structure maintains high gas barrier properties and resistance to appearance defects even under harsh conditions, such as retorting and physical stresses, while maintaining interlayer adhesion and mechanical integrity.

Implementation Method 1

the layer (Z) is a layer containing a reaction product formed by a reaction between a metal oxide (C) containing aluminum and a phosphorus compound (D)

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

a coating liquid (S) containing the compound (A), the polymer (B), and the solvent; a layer (Y) formation step including: a step (Y-i) of mixing the compound (A), the polymer (B), and the solvent

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3165359B1Multilayer structure and method for manufacturing same, packaging material and product in which same is used, and electronic device
Publication Date: 2019.04.10 KURARAY CO LTD
  • EP3165359B1 patent drawingFigure 1~2
  • EP3165359B1 patent drawingFigure 3~4
  • EP3165359B1 patent drawingFigure 5

AI summary

The present invention relates to a multilayer structure including a base (X), a layer (Y), and a layer (Z) disposed contiguous to the layer (Y). The layer (Y) includes a compound (A) containing a phosphorus atom and a polymer (B) having a hydroxy group and/or carboxyl group. A mass ratio between the compound (A) and the polymer (B) is 15 : 85 to 99 : 1 in the layer (Y). The layer (Z) is a layer containing aluminum atoms.