Cyclobutanediol Polyester Bottles for Heat-Resistant Clarity
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Solution Overview
Problem
Current plastic materials for containers, such as PET and polycarbonate, face challenges with high-heat applications due to poor barrier properties and processing difficulties, leading to a need for materials with high impact strength, heat resistance, and processability that can maintain performance at elevated temperatures.
Innovation Solution
A polyester composition comprising terephthalic acid, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 1,4-cyclohexanedimethanol, with specific mole percentages and inherent viscosities, which provides high impact strength, heat resistance, and processability, while maintaining chemical resistance and clarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If PET is used for container production, then processability and clarity are good, but heat resistance and barrier properties deteriorate at elevated temperatures
Solution Approach 1:
The patent changes the chemical composition parameters of the polyester by incorporating 1,4-cyclohexanedimethanol (CHDM) units (5-30 mole%) and controlling the inherent viscosity (0.6-1.2 dL/g), which modifies the molecular structure to achieve both high heat resistance (Tg ≥ 80°C) and maintained barrier properties at elevated temperatures
Solution Approach 2:
The patent creates a composite polyester material combining terephthalic acid units, CHDM units, and controlled crystallinity to produce a material that integrates the heat resistance of high-Tg polymers with the barrier properties of semi-crystalline structures
2Temperature
If polycarbonate or acrylic polymers are used for high-heat applications, then heat resistance is improved, but barrier properties and chemical resistance deteriorate
Solution Approach 1:
The patent modifies the polymer chemistry by using polyester backbones with aromatic rings and cyclic structures (CHDM) that provide both thermal stability (heat resistance) and dense packing that maintains excellent barrier and chemical resistance properties
3Temperature
If PCT is used to achieve heat resistance, then crystallization rate is high, but processability and ability to form amorphous articles deteriorate
Solution Approach 1:
The patent adjusts the crystallization kinetics by controlling CHDM content (5-30 mole%) and inherent viscosity (0.6-1.2 dL/g), which slows the crystallization rate sufficiently to allow amorphous article formation while maintaining the heat resistance associated with semi-crystalline structures
Solution Approach 2:
The patent creates a material with dynamic crystallization behavior that can be controlled during processing - the crystallization rate is slowed to enable amorphous forming when needed, but the material retains the capacity for crystalline structure development for heat resistance when required
4Ease of manufacture
If ethylene glycol-modified PCT is used to slow crystallization, then processability is improved, but glass transition temperature and impact strength deteriorate
Solution Approach 1:
The patent replaces ethylene glycol with 1,4-cyclohexanedimethanol (CHDM), which has a rigid cyclic structure that maintains or improves impact strength and Tg while still providing the necessary crystallization rate control for processability
Solution Approach 2:
The patent introduces rigid CHDM cyclic structures at specific concentrations (5-30 mole%) that locally enhance mechanical properties (impact strength, Tg) while the overall polymer matrix maintains processability through controlled crystallization kinetics
Data Source
AI summary
Described are bottle(s) comprising polyesters comprising (a) a dicarboxylicacid component comprising terephthalic acid residues; optionally, aromatic dicarboxylic acid or aliphatic dicarboxylic acid residues; 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and 1,4-cyclohexanedimethanol residues.