Bio-polyethylene Resin Composition Transparency Stabilization

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Bio-polyethylene resin-based molded products face issues with thermal degradation leading to gel formation and reduced transparency due to high levels of low molecular weight components, which affects their appearance and mechanical strength.

Innovation Solution

A resin composition combining bio-polyethylene resin with ethylene-vinyl alcohol copolymer (EVOH) and an alkali metal salt in specific ratios, which controls pH and suppresses thermal degradation, thereby preventing gel formation and maintaining transparency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If bio-polyethylene resin is used to replace petroleum-derived plastic, then environmental burden is reduced, but thermal degradation occurs during molding resulting in gel formation and reduced transparency

Engineering Contradiction:

Improveenvironmental burdenVSAvoidtransparency

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent introduces an alkali metal salt as an intermediary substance that mediates between the bio-polyethylene resin and the molding process. This salt acts as a thermal stabilizer that prevents direct thermal degradation of the resin, thereby maintaining transparency while allowing the use of environmentally friendly bio-based materials.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical parameters of the molding system by adding specific alkali metal salts at controlled concentrations. This parameter change modifies the thermal stability and degradation characteristics of the bio-polyethylene resin, preventing gel formation and maintaining optical properties during the molding process.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If bio-polyethylene resin with high low molecular weight components is used, then renewability is improved, but thermal degradation during molding causes gel formation and appearance degradation

Engineering Contradiction:

ImproverenewabilityVSAvoidappearance

Core Design Contradiction:

Adaptability or versatilityVSShape

Solution Approach 1:

The alkali metal salt serves as a protective intermediary that shields the low molecular weight components of the bio-polyethylene resin from thermal degradation. This allows the resin to maintain its renewability advantage while preventing the appearance degradation that would otherwise result from thermal breakdown during molding.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies beforehand cushioning by adding the alkali metal salt to the resin composition before molding. This pre-added stabilizer cushions against thermal degradation during the molding process, preventing gel formation and appearance defects while preserving the renewable characteristics of the bio-polyethylene resin.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Ease of repair

If recovered material layer is used to promote recycling, then resource recycling is improved, but thermal degradation during molding results in gel formation and transparency reduction

Engineering Contradiction:

Improveresource recyclingVSAvoidtransparency

Core Design Contradiction:

Ease of repairVSReliability

Solution Approach 1:

The alkali metal salt acts as a stabilizing intermediary that protects recovered materials during the molding process. This allows recovered materials to be effectively recycled while preventing thermal degradation that would otherwise cause gel formation and transparency loss in the final product.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 effectively suppresses gel formation and maintains transparency, resulting in molded products with excellent appearance and mechanical properties, comparable to those made from petroleum-derived polyethylene resins, promoting the use of bio-polyethylene resins and reducing environmental burden.

Implementation Method 1

the alkali metal salt (C) controls the pH of the resin composition, which is in contact with the high-temperature metals

Methodology Applied

Scientific EffectpH control:

Implementation Method 2

suppressing thermal degradation of the low molecular weight components of the bio-polyethylene resin

Methodology Applied

Scientific EffectThermal degradation suppression:

Data Source

PatentEP4134233B1Resin composition, and film and multilayer structure body using same

Publication Date: 2025.01.08 MITSUBISHI CHEM CORP

AI summary

The present disclosure provides a resin composition containing a bio-polyethylene resin (A), an ethylene-vinyl alcohol copolymer (B), and an alkali metal salt (C), wherein the content of the alkali metal salt (C) is 10 ppm to 1500 ppm, in terms of metal, with respect to the weight of the ethylene-vinyl alcohol copolymer (B). With this resin composition, gel formation and a reduction in transparency during molding are suppressed, and a molded product having an excellent appearance can thus be obtained.