Multilayer Resin Container with COC-LLDPE Inner Layer

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Solution Overview

Problem

Existing resin containers made from cyclic olefin polymers and copolymers are hard and difficult to mold, making it challenging to easily expel liquid content, and they are prone to inter-layer peeling when configured as a multilayer structure.

Innovation Solution

A resin container with a multilayer structure, where the innermost layer is made of a cyclic olefin copolymer and linear low-density polyethylene, and the outer layer is made of low-density polyethylene, allowing for easier deformation and liquid expulsion while minimizing inter-layer peeling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cyclic olefin polymer or copolymer is used to make resin container, then chemical resistance and sealability are improved, but moldability and ease of deformation are worsened

Engineering Contradiction:

ImprovesealabilityVSAvoidmoldability

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention uses a multilayer structure combining cyclic olefin copolymer (COC) and linear low-density polyethylene (LLDPE) in the first layer, and low-density polyethylene (LDPE) in the second layer. This composite material approach allows the container to achieve both chemical resistance from COC and improved moldability from LLDPE and LDPE, resolving the contradiction between reliability and ease of manufacture.

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If multilayer structure is configured with softer outer layer and harder inner layer, then ease of deformation is improved, but inter-layer peeling occurs

Engineering Contradiction:

Improveease of deformationVSAvoidinter-layer peeling

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The invention specifies precise compositional parameters for each layer: the first layer contains COC and LLDPE in a specific ratio, while the second layer contains LDPE. By controlling these material parameters and their proportions, the invention achieves both ease of deformation and prevention of inter-layer peeling, resolving the contradiction between ease of operation and compositional stability.

Inventive Principle:

Principle #35Parameter changes

3Force

If outlet is pointed downward to expel liquid content, then gravity assistance is improved, but sufficient liquid expulsion is not achieved due to hard resin

Engineering Contradiction:

Improvegravity forceVSAvoidliquid expulsion

Core Design Contradiction:

ForceVSEase of operation

Solution Approach 1:

The invention uses a multilayer structure with LLDPE and LDPE that provides flexibility and ease of deformation. This allows the container to be easily compressed to apply additional pressure on the liquid content, supplementing gravity force and enabling sufficient liquid expulsion even when the outlet is pointed downward.

Inventive Principle:

Principle #30Flexible shells and thin films

Data Source

PatentUS12295910B2Resin container and resin container connected body

Publication Date: 2025.05.13 ROHTO PHARM CO LTD

AI summary

The present invention is a resin container having a multilayer structure including a first layer that comes into contact with liquid content and a second layer that is in contact with the first layer from an outer side of the first layer. The first layer includes a cyclic olefin copolymer and a linear low-density polyethylene resin, and the second layer includes a low-density polyethylene resin.