Co-Polyester Resin Composition for Die Contamination and Recycling Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Copolymerized polyester resins containing diethylene glycol and sodium sulfoisophthalate suffer from die contamination and foreign matter adhesion during production, and resin coloration and molecular weight reduction during recycling, due to the presence of specific cyclic dimers and reduced thermal stability.
Innovation Solution
The copolymerized polyester resin is formulated with controlled carboxyl end group concentration and specific catalysts to minimize cyclic dimer content, ensuring transparency, moldability, and recyclability by using terephthalic acid, ethylene glycol, and sodium sulfoisophthalate within defined ratios, along with controlled catalysts to enhance thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If copolymerized polyester resin is copolymerized with diethylene glycol and sodium sulfoisophthalate to improve transparency and moldability, then transparency and moldability are improved, but die contamination and foreign matter adhesion occur during continuous production
Solution Approach 1:
The invention changes the chemical composition parameters by incorporating sodium sulfoisophthalate at a specific ratio (0.05 to 10 mol% based on total dicarboxylic acid components) and controlling diethylene glycol content (1 to 22 mol% based on total glycol components). This parameter optimization resolves the contradiction by achieving the right balance between transparency enhancement and minimizing die contamination during continuous production.
2Illumination intensity
If copolymerized polyester resin is copolymerized with diethylene glycol and sodium sulfoisophthalate to improve transparency and moldability, then transparency and moldability are improved, but resin coloration and molecular weight reduction occur during recycling
Solution Approach 1:
The invention optimizes the compositional parameters by controlling sodium sulfoisophthalate content (0.05 to 10 mol%) and diethylene glycol content (1 to 22 mol%), which enhances transparency while maintaining adequate thermal stability for recycling applications.
Solution Approach 2:
The invention creates a composite polyester resin system that combines terephthalic acid, aliphatic dicarboxylic acids, sodium sulfoisophthalate, ethylene glycol, and diethylene glycol in specific ratios. This composite material approach allows the resin to simultaneously achieve transparency, moldability, and improved recyclability by balancing the properties of different components.
Data Source
AI summary
An object of the present invention is to solve a problem that when products such as films, molded products, or fibers are continuously produced from a copolymerized polyester resin copolymerized with diethylene glycol and sodium sulfoisophthalate, die contamination and adhesion of foreign matter to the products occur and a problem that during recycling of a copolymerized polyester resin copolymerized with diethylene glycol and sodium sulfoisophthalate for improving transparency and moldability, the resin is colored or the molecular weight of the resin is reduced. A copolymerized polyester resin containing terephthalic acid as a main dicarboxylic acid component and ethylene glycol as a main glycol component, wherein when a total amount of dicarboxylic acid components in all polyester resin components is taken as 100 mol%, a ratio of the terephthalic acid component to all the dicarboxylic acid components is 79.95 to 94.95 mol%, a ratio of the aliphatic acid having 6 to 40 carbon atoms to all the dicarboxylic acid components is 5 to 20 mol%, and a ratio of sodium sulfoisophthalate to all the dicarboxylic acid components is 0.05 to 10 mol%, when a total amount of glycol components is taken as 100 mol%, a ratio of diethylene glycol to all glycol components is 1 to 22 mol%, a content of a free cyclic dimer consisting of sodium sulfoisophthalate and ethylene glycol is 30 ppm or less, and a content of a free cyclic dimer consisting of terephthalic acid, sodium sulfoisophthalate, ethylene glycol and diethylene glycol is 40 ppm or less.