Polyamide Resin Injection Blow-Molded Container

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Solution Overview

Problem

Existing injection blow-molded containers face challenges in achieving optimal moldability, impact resistance, and solvent resistance, particularly when using poly(metaxylylene adipamide) as a gas barrier resin.

Innovation Solution

A container is developed using a resin composition comprising 60 to 95 parts by mass of a polyamide resin (A) with 70 mol % or more of diamine-derived constitutional units from xylylenediamine and 70 mol % or more of dicarboxylic acid-derived constitutional units from α,ω-linear aliphatic dicarboxylic acid, combined with 5 to 40 parts by mass of a polyamide resin (B) lacking xylylenediamine units, which includes an alkylene group with 5 to 12 carbon atoms, to enhance moldability and impact resistance while maintaining solvent resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If poly(metaxylylene adipamide) is used as a gas barrier resin, then solvent resistance is improved, but moldability and impact resistance deteriorate

Engineering Contradiction:
Improvesolvent resistanceVSAvoidmoldability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses a composite resin composition comprising poly(metaxylylene adipamide) (60-95 parts by mass) combined with polyamide resin having an alkylene group (5-40 parts by mass). This composite structure allows the container to inherit the excellent solvent resistance from poly(metaxylylene adipamide) while the polyamide resin component improves moldability and impact resistance, thus resolving the contradiction between solvent resistance and moldability.

Inventive Principle:
Principle #40Composite materials

2Reliability

If poly(metaxylylene adipamide) is used as a gas barrier resin, then solvent resistance is improved, but impact resistance deteriorates

Engineering Contradiction:
Improvesolvent resistanceVSAvoidimpact resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent combines poly(metaxylylene adipamide) with polyamide resin having an alkylene group to create a composite material system. The polyamide resin component specifically contributes to improving impact resistance while maintaining the solvent resistance provided by poly(metaxylylene adipamide), thereby resolving the contradiction between solvent resistance and impact resistance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent controls the glass transition temperature difference between the two polyamide resins to be within a specific range (−50°C ≤ Tg(A)−Tg(B) < 0°C). This parameter control ensures that the container achieves both excellent impact resistance and solvent resistance by optimizing the thermal properties of the composite material system.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If poly(metaxylylene adipamide) is used as a gas barrier resin, then gas barrier performance is improved, but moldability deteriorates

Engineering Contradiction:
Improvegas barrier performanceVSAvoidmoldability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs a composite resin composition where poly(metaxylylene adipamide) provides gas barrier performance and is combined with polyamide resin having an alkylene group that enhances moldability. This composite approach allows the container to maintain excellent gas barrier properties while achieving superior moldability during the injection blow-molding process.

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 container exhibits improved moldability, impact resistance, and solvent resistance, with a glass transition temperature difference between the two polyamide resins ensuring better drop impact resistance and storage stability, even when retaining organic compounds.

Implementation Method 1

a glass transition temperature difference between the two polyamide resins ensuring better drop impact resistance and storage stability

Methodology Applied
Scientific EffectGlass transition:

Data Source

PatentUS11207861B2Injection blow-molded container
Publication Date: 2021.12.28 MITSUBISHI GAS CHEM CO INC

AI summary

An object of the present invention is to provide an injection blow container that is excellent in moldability and impact resistance and furthermore, excellent in solvent resistance. The injection blow-molded container of the present invention comprises 60 to 95 parts by mass of a polyamide resin (A) and 5 to 40 parts by mass of a polyamide resin (B) (per 100 parts by mass in total of the polyamide resin (A) and the polyamide resin (B)), wherein the polyamide resin (A) comprises a diamine-derived constitutional unit and a dicarboxylic acid-derived constitutional unit, wherein 70 mol % or more of the diamine-derived constitutional unit is a constitutional unit derived from xylylenediamine, 70 mol % or more of the dicarboxylic acid-derived constitutional unit is a constitutional unit derived from α,ω-linear aliphatic dicarboxylic acid having 4 to 12 carbon atoms, and 30 mol % or less thereof is a constitutional unit derived from isophthalic acid; and the polyamide resin (B) comprises no constitutional unit derived from xylylenediamine, and is a polyamide resin having an alkylene group having 5 to 12 carbon atoms.