Thermoplastic Resin Composition for Easy Openable Containers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thermoplastic resin compositions for packaging fail to achieve a balance between high heat seal strength and easy openability while maintaining good extrusion lamination moldability and peeling appearance, with existing solutions either compromising on seal strength or moldability.
Innovation Solution
A thermoplastic resin composition comprising 60-84% crystalline polyester with an aliphatic dicarboxylic acid unit, 3-23% polyolefin or amorphous polyester, and 3-28% styrene-based thermoplastic elastomer, along with an amine-modified styrene-based thermoplastic elastomer, which enhances heat seal strength, easy openability, and extrusion lamination moldability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a delamination-type sealant is used to achieve strong heat seal, then heat seal strength is improved, but film residue is generated at seal breaking and easy openability deteriorates
Solution Approach 1:
The sealant is divided into two functional layers: a sealing layer containing crystalline polyester for strong adhesion to the container, and a holding layer containing amorphous polyester with lower melting point that separates cleanly during peeling. This segmentation allows the sealing layer to provide heat seal strength while the holding layer ensures easy openability without residue
Solution Approach 2:
Different regions of the sealant structure are assigned different material properties: the sealing layer uses crystalline polyester with high melting point for strong bonding, while the holding layer uses amorphous polyester with lower melting point for clean separation. Each layer has localized quality optimized for its specific function in the sealing and peeling process
2Ease of operation
If a cohesive peeling-type sealant is used to achieve easy openability, then easy openability is improved, but heat seal strength deteriorates
Solution Approach 1:
Rather than using a single homogeneous material, the sealant is segmented into two layers with distinct material compositions. The sealing layer uses crystalline polyester for strong adhesion, while the holding layer uses amorphous polyester for clean separation. This segmentation allows both strong sealing and easy opening to be achieved simultaneously
Solution Approach 2:
The sealant is constructed as a composite material system combining crystalline polyester and amorphous polyester in specific layers. This composite structure leverages the high adhesion properties of crystalline polyester for sealing while utilizing the low melting point and clean separation properties of amorphous polyester for easy opening, achieving both contradictory requirements
3Ease of operation
If the sealing layer is formed with specific resin composition to achieve easy openability, then easy openability is improved, but extrusion lamination moldability deteriorates
Solution Approach 1:
The sealant structure is segmented so that the holding layer contains the amorphous polyester components that provide easy openability, while the sealing layer contains the crystalline polyester that ensures good extrusion lamination moldability. This segmentation allows each layer to be optimized for its specific function without compromising the other
Solution Approach 2:
The invention changes the material parameters of different layers: the holding layer uses amorphous polyester with lower melting point and higher flexibility for easy opening, while the sealing layer uses crystalline polyester with higher melting point and better processability for extrusion lamination. This parameter differentiation resolves the contradiction between easy openability and moldability
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 composition provides a sealing layer with high heat seal strength, excellent easy openability, and improved extrusion lamination moldability, ensuring effective sealing and easy peeling without compromising film stability or moldability.
Implementation Method 1
a crystalline polyester containing an aliphatic dicarboxylic acid unit and having a melting peak temperature in the range of 110 to 140°C
Implementation Method 2
the sealing layer is thermally fused, in part, to the adherend at the heat sealing
Data Source
AI summary
The present invention provides a thermoplastic resin composition ensuring easy openability by cohesive peeling, excellent extrusion lamination moldability and sufficiently high heat seal strength and being capable of forming a sealing layer excellent in easy openability, extrusion lamination moldability, peeling appearance, etc. The present invention relates to a thermoplastic resin composition containing the following components (A) to (C) and containing from 60 to 84 % by weight of the component (A), from 3 to 23 % by weight of the component (B), and from 3 to 28 % by weight of the component (C). Component (A): A crystalline polyester containing an aliphatic dicarboxylic acid unit and having a melting peak temperature in the range of 110 to 140°C. Component (B): At least either one of an amorphous polyester and a polyolefin. Component (C): A styrene-based thermoplastic elastomer composed of at least one member out of the group consisting of a block copolymer having a polymer block P derived from a vinyl aromatic compound and a polymer block Q derived from a conjugated diene, and a hydrogenation product thereof. The total amount of 1,2- and 3,4-bond units in the block Q is 60 mol% or more.