Polyester Container Gas Barrier via Catalyst Residue and Additive
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Solution Overview
Problem
Polyethylene terephthalate (PET) containers have insufficient gas barrier properties, particularly to oxygen and carbon dioxide, limiting their use in smaller packages and for oxygen-sensitive products, and existing solutions require significant capital investment or compromise on clarity and mechanical performance.
Innovation Solution
A polyester container composition with a polycondensation catalyst residue from metals in groups 3, 4, 13, and 14 of the Periodic Table, combined with a reactive organic gas barrier enhancing additive, which maintains high intrinsic viscosity and enhances gas barrier properties without degrading the PET, allowing for effective packaging of carbonated soft drinks and oxygen-sensitive beverages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external or internal coatings are used to enhance gas barrier, then gas barrier is improved, but capital investment and energy usage increase
Solution Approach 1:
The polyester resin itself provides the gas barrier enhancement through incorporated barrier additives, eliminating the need for separate coating equipment and processes. The container wall material inherently achieves enhanced barrier performance without requiring external coating systems.
Solution Approach 2:
The invention modifies the chemical composition parameters of the polyester resin by incorporating specific barrier additives (such as polyamide, polyethylene naphthalate, or other polymers with low gas permeability) during the resin formulation stage, rather than applying coatings after manufacturing.
2Reliability
If multi-layered containers are used, then gas barrier is improved, but capital investment and manufacturing complexity increase
Solution Approach 1:
Instead of changing the structural architecture to multi-layers, the invention changes the compositional parameters of a single-layer polyester resin by incorporating barrier additives, achieving enhanced gas barrier through material composition rather than structural complexity.
Solution Approach 2:
The invention creates a composite polyester resin by incorporating barrier additives (such as polyamide or polyethylene naphthalate) into the polyester matrix during resin formulation, achieving enhanced gas barrier properties in a single-layer container wall without requiring multi-layer construction.
3Reliability
If barrier additives are added to PET, then gas barrier is improved, but intrinsic viscosity decreases
Solution Approach 1:
The invention optimizes the concentration parameter of barrier additives within a specific range (0.1-5 weight percent) to achieve enhanced gas barrier while minimizing impact on intrinsic viscosity. The formulation parameters are controlled to maintain PET's mechanical properties.
Solution Approach 2:
The invention uses composite materials where barrier additives are incorporated into the PET matrix in controlled amounts, creating a formulation that balances gas barrier enhancement with preservation of the base polymer's mechanical and viscous properties.
4Adaptability or versatility
If smaller PET containers are used, then packaging flexibility is improved, but gas permeability increases
Solution Approach 1:
The invention changes the compositional parameters of the polyester resin by incorporating barrier additives, which improves the gas barrier performance of smaller containers. This allows smaller packaging sizes to maintain adequate gas barrier despite increased surface area to volume ratio.
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 solution provides a PET container with improved gas barrier performance while maintaining optical clarity and physical properties, extending the shelf life of carbonated beverages and enabling the use of PET in packaging applications previously limited by gas permeability.
Implementation Method 1
The polyester is made using at least one first polycondensation catalyst preferably selected from the group consisting of metals in groups 3, 4, 13, and 14 of the Periodic Table and comprises a catalyst residue remaining in the polyester from formation of the polyester
Implementation Method 2
A barrier additive for the PET or a polymer with inherent barrier properties would be preferred solutions
Implementation Method 3
L. M. Robeson and J. A. Faucher disclose in J. Polymer Science, Part B 7, 35-40 (1969) that certain additives could be incorporated into polymers to increase their modulus and gas barrier properties through an antiplasticization mechanism
Data Source
AI summary
A polyester container with enhanced gas barrier properties includes a polyester composition having an IV of 0.65 dL/g to 1.0 dL/g and including a polyester and a reactive organic gas barrier enhancing additive. The polyester is made using at least one first polycondensation catalyst, non-limiting examples of which include metals in Groups 3, 4, 13, and 14 of the Periodic Table and includes a catalyst residue remaining in the polyester from formation of the polyester. The catalyst residue includes at least a portion of the at least one first polycondensation catalyst.